CN111201257A - Polyisocyanate composition, coating composition and coating film - Google Patents

Polyisocyanate composition, coating composition and coating film Download PDF

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Publication number
CN111201257A
CN111201257A CN201880065452.4A CN201880065452A CN111201257A CN 111201257 A CN111201257 A CN 111201257A CN 201880065452 A CN201880065452 A CN 201880065452A CN 111201257 A CN111201257 A CN 111201257A
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group
polyisocyanate
polyisocyanate composition
mass
compound
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东孝一郎
山内理计
福地崇史
片川洋德
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Asahi Kasei Corp
Asahi Chemical Co Ltd
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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/02—Polymeric products of isocyanates or isothiocyanates of isocyanates or isothiocyanates only
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
    • C08G18/72—Polyisocyanates or polyisothiocyanates
    • C08G18/73—Polyisocyanates or polyisothiocyanates acyclic
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
    • C08G18/72—Polyisocyanates or polyisothiocyanates
    • C08G18/77—Polyisocyanates or polyisothiocyanates having heteroatoms in addition to the isocyanate or isothiocyanate nitrogen and oxygen or sulfur
    • C08G18/78—Nitrogen
    • C08G18/79—Nitrogen characterised by the polyisocyanates used, these having groups formed by oligomerisation of isocyanates or isothiocyanates
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D175/00—Coating compositions based on polyureas or polyurethanes; Coating compositions based on derivatives of such polymers
    • C09D175/04—Polyurethanes

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Wood Science & Technology (AREA)
  • Polyurethanes Or Polyureas (AREA)
  • Paints Or Removers (AREA)

Abstract

The polyisocyanate composition of the present invention contains a polyisocyanate having an isocyanurate group derived from an aliphatic diisocyanate containing 1, 6-hexamethylene diisocyanate, and satisfies the following conditions 1) to 2) when stored at 50 ℃ for 1 month. 1) The HDI content in the polyisocyanate composition before storage is 0.001 to 0.1 mass%; 2) the HDI content in the polyisocyanate composition after storage is 0.001 to 0.1 mass%.

Description

Polyisocyanate composition, coating composition and coating film
Technical Field
The present invention relates to a polyisocyanate composition, a coating composition and a coating film.
The present application claims priority based on japanese patent application No. 2017-203752, japanese patent application No. 2017-203753, japanese patent application No. 2017-203754, and japanese patent application No. 2017-203755, which were applied in japan at 20/10/2017, and japanese patent application No. 2017-217815, which were applied in japan at 11/10/2017, the contents of which are incorporated herein.
Background
Urethane coating compositions containing a polyisocyanate as a curing agent are widely used as coatings for automobiles, interior and exterior parts of buildings, home electric appliances, and the like because the resulting coating films are excellent in chemical resistance, flexibility, weather resistance, and the like. Among these, a coating film obtained from a polyisocyanate derived from an aliphatic diisocyanate has a characteristic of no yellowing. Further, isocyanurate polyisocyanates are known to be excellent in coating film properties such as weather resistance and chemical resistance, and are used in fields where these properties are required.
As a prior art document concerning isocyanurate type polyisocyanates, for example, patent document 1 discloses a polyisocyanate composition excellent in moisture stability by controlling the phosphorus concentration in the polyisocyanate composition within a constant range.
Further, patent documents 2 and 3 disclose polyisocyanate compositions which have low viscosity and are reduced in the generation of 1, 6-hexamethylene diisocyanate (hereinafter, may be abbreviated as "HDI" or 1, 6-diisocyanatohexane) during storage by specifying the components in the compositions and the composition ratio thereof.
Further, patent document 4 discloses a method in which a monool and HDI are first reacted to produce a urethane body, and then isocyanurated. A polyisocyanate composition having a high solid content, a low viscosity and a low polar organic solvent dilutability is obtained.
On the other hand, a polyisocyanate composition containing an isocyanurate group-containing polyisocyanate derived from an HDI-containing aliphatic diisocyanate is excellent in heat resistance as well as weather resistance, and thus has been widely used in various applications.
In recent years, due to the hot tide of global environmental protection, technology development has been actively conducted to reduce the viscosity of polyisocyanate compositions used as curing agents (see, for example, patent documents 5 to 8). This is because the amount of the organic solvent used in the coating composition can be reduced by lowering the viscosity of the polyisocyanate composition.
However, in the case of a high-solid coating material and a solvent-free coating material in which the amount of an organic solvent used is reduced, the amount of the solvent used decreases, and the penetration of the solvent into a coating-finished layer decreases, and adhesion tends to decrease at the time of recoating. In addition, in general, in order to lower the viscosity, the molecular weight of the polyol used is also lowered, and the crosslinking density is thereby lowered, and various durability (saline spray durability, stain resistance) as a coating film tends to be lowered.
However, among polyisocyanate compositions containing a polyisocyanate having isocyanurate groups derived from an HDI-containing aliphatic diisocyanate, polyisocyanate compositions containing a polyisocyanate having biuret groups are widely used because they are excellent in weather resistance and heat resistance and in adhesion to various substrates, particularly to various metals and highly polar resin substrates. Therefore, many technical developments have been made on polyisocyanate compositions having biuret groups (for example, see patent documents 9 to 17).
However, in general, a polyisocyanate composition containing a polyisocyanate having a biuret group has a problem that a diisocyanate monomer increases after production and during storage, and odor derived from a diisocyanate and the like become more problematic, as compared with a polyisocyanate composition containing a polyisocyanate having an isocyanurate group. In order to solve such problems, a polyisocyanate composition containing a biuret group-containing polyisocyanate has been recently developed which is reduced in the increase of diisocyanate monomers when stored at 25 ℃ (see, for example, patent documents 18 to 19).
On the other hand, from the viewpoints of recent global environmental conservation, safety and hygiene in labor, and the like, there is a demand for a water-based two-component urethane coating composition used as a solvent-based coating. For example, the dispersibility in water can be achieved by introducing a nonionic hydrophilic group into a polyisocyanate (see, for example, patent documents 20 and 21).
In addition, the polyisocyanate composition and the polyol form a crosslinked coating film at ordinary temperature. For the one-pack type baking paint, a melamine-based curing agent is widely used, but in recent years, formalin is generated by fingering when a melamine-based curing agent is used. Therefore, from the viewpoint of global environment, safety, hygiene, and the like, attention is being paid to a blocked polyisocyanate composition containing a blocked polyisocyanate blocked with a blocking agent that dissociates isocyanate groups in the polyisocyanate composition by heating.
Examples of blocked polyisocyanate compositions that can form a crosslinked coating film at a relatively low temperature include blocked polyisocyanate compositions that use a pyrazole compound as a blocking agent (see, for example, patent document 22). Further, for example, there is a blocked isocyanate composition containing 1 or more isocyanates selected from the group consisting of aliphatic isocyanates and alicyclic isocyanates, which are blocked using a pyrazole compound and an oxime compound as a blocking agent (for example, see patent document 23).
Documents of the prior art
Patent document
Patent document 1: japanese patent No. 4201582
Patent document 2: japanese patent No. 5178200
Patent document 3: japanese patent No. 5183206
Patent document 4: japanese patent No. 3065889
Patent document 5: japanese laid-open patent publication No. H05-222007
Patent document 6: japanese patent No. 3055197
Patent document 7: international publication No. 2007/046470
Patent document 8: japanese Kokai publication Hei-2004-534870
Patent document 9: japanese laid-open patent publication No. S49-134629
Patent document 10: japanese laid-open patent publication No. 63-174961
Patent document 11: japanese examined patent publication No. 61-060093
Patent document 12: japanese examined patent publication No. 61-026778
Patent document 13: japanese examined patent publication No. 62-041496
Patent document 14: japanese examined patent publication (Kokoku) No. 02-062545
Patent document 15: japanese examined patent publication (Kokoku) No. 05-017222
Patent document 16: japanese laid-open patent publication No. H08-225511
Patent document 17: japanese patent No. 4367988
Patent document 18: chinese patent application publication No. 105601565 specification
Patent document 19: chinese patent application publication No. 106084182 specification
Patent document 20: japanese laid-open patent publication No. 5-222150
Patent document 21: japanese laid-open patent publication No. 9-328654
Patent document 22: european patent application publication No. 159117
Patent document 23: japanese patent laid-open publication No. 2011-236388
Disclosure of Invention
Problems to be solved by the invention
However, when the techniques described in patent documents 1to 4 are used, there is still room for improvement in the amount of HDI generation, the color stability, and the viscosity stability of the obtained polyisocyanate composition during storage.
Although the use of the techniques described in patent documents 5 and 6 can provide a polyisocyanate composition having a low viscosity, the polyisocyanate compositions obtained by these techniques have low crosslinkability, and the diisocyanate monomer concentration tends to increase during storage of these polyisocyanate compositions. Therefore, there is a problem that the use is limited.
Further, when a polyisocyanate composition having a low viscosity is used for a high-solid coating material and a solventless coating material in general, various durability (durability and stain resistance when spraying with a salt water) upon forming a coating film are not sufficient, and improvement is expected. Even the polyisocyanate compositions described in patent documents 7 and 8 may have insufficient durability (salt spray durability and stain resistance) as a coating film.
In addition, in the techniques described in patent documents 18 and 19, an increase in diisocyanate during storage at 25 ℃ is evaluated, but exposure to higher temperatures may occur in summer or after coating. Therefore, a polyisocyanate composition containing a polyisocyanate having a biuret group, which is reduced in the increase of diisocyanate monomers even after storage at a high temperature of about 50 ℃ or after coating and further curing, is desired.
In addition, in the polyisocyanate composition described in patent document 20 or 21, since much diisocyanate remains in the composition, the hardness and water resistance of the coating film may be deteriorated.
In addition, in the application of the coating film using the blocked polyisocyanate composition, in the application of irradiating direct sunlight and the application of using the blocked polyisocyanate composition under high temperature and high humidity, chemical resistance (acid resistance, methanol resistance) under severe conditions such as high temperature is essential. However, these properties may be insufficient for a coating film using a conventional blocked polyisocyanate composition.
The present invention has been made in view of the above circumstances, and provides, in embodiment 1, a polyisocyanate composition in which an HDI-derived odor is suppressed and which is excellent in color stability and viscosity stability. Also disclosed is a coating composition which contains the polyisocyanate composition and has good solvent-dilutability. Also disclosed is a coating film which contains the above-mentioned coating composition and has excellent chemical resistance.
In embodiment 2, a polyisocyanate composition having a low viscosity and capable of forming a coating film excellent in adhesion to a recoated film, durability when sprayed with brine, and stain resistance, and a coating composition containing the polyisocyanate composition are provided. Further, a coating film excellent in adhesion to a recoated film, durability when sprayed with salt water and stain resistance is provided.
In embodiment 3, a polyisocyanate composition which is less in odor derived from a diisocyanate monomer and can form a coating film having excellent adhesion to a substrate and excellent stain resistance, and a coating composition containing the polyisocyanate composition are provided. Further, a coating film which is reduced in odor derived from a diisocyanate monomer and is excellent in adhesion to a substrate and stain resistance is provided.
In embodiment 4, a polyisocyanate composition is provided which gives a cured product excellent in hardness and water resistance.
In embodiment 5, a blocked polyisocyanate composition is provided which gives a coating film excellent in acid resistance and methanol resistance under high temperature conditions. Also disclosed are a coating composition and a coating film each using such a blocked polyisocyanate composition.
Means for solving the problems
That is, the present invention includes the following aspects.
(1) A polyisocyanate composition which satisfies the following conditions 1) and 2) when stored at 50 ℃ for 1 month,
1) the polyisocyanate composition before storage has a 1, 6-Hexamethylene Diisocyanate (HDI) content of 0.001 to 0.1 mass%;
2) the HDI content in the polyisocyanate composition after storage is 0.001 to 0.1 mass%.
(2) The polyisocyanate composition according to the above (1), which comprises an isocyanurate group-containing polyisocyanate derived from an HDI-containing aliphatic diisocyanate,
the polyisocyanate composition before storage under condition 1) above has an HDI content of 0.01 to 0.1 mass%;
the condition 2) is that the HDI content in the polyisocyanate composition after storage is 0.01 mass% or more and 0.1 mass% or less;
the polyisocyanate composition also satisfies condition 3) that the difference between the HDI content in the polyisocyanate composition before and after storage is 0.08 mass% or less.
(3) The polyisocyanate composition according to the above (2), wherein the content of HDI in the polyisocyanate composition before storage is 0.01% by mass or more and 0.08% by mass or less in the above condition 1).
(4) The polyisocyanate composition according to the above (2) or (3), wherein the viscosity of the polyisocyanate composition is 1000 mPas or more and 5000 mPas or less.
(5) A coating composition comprising the polyisocyanate composition according to any one of the above (2) to (4).
(6) A coating film formed by the coating composition of (5) above.
(7) The polyisocyanate composition according to the above (1), which comprises an isocyanurate group-containing polyisocyanate derived from an aliphatic diisocyanate containing 1, 6-hexamethylene diisocyanate,
the ratio of the component having a number average molecular weight of 700 or less to the total mass of the polyisocyanate composition is 70% by mass or more, and
in the above condition 2), the HDI content in the polyisocyanate composition after storage is 0.01 mass% or more and 0.1 mass% or less.
(8) A coating composition comprising the polyisocyanate composition described in (7) above and at least one member selected from the group consisting of acrylic polyols having a hydroxyl value of 10mgKOH/g or more and 200mgKOH/g or less and polyester polyols having a hydroxyl value of 10mgKOH/g or more and 200mgKOH/g or less.
(9) A coating film formed by the coating composition of (8) above.
(10) The polyisocyanate composition according to the above (1), which comprises a polyisocyanate having isocyanurate groups and biuret groups derived from an aliphatic diisocyanate containing 1, 6-hexamethylene diisocyanate,
when the molar amount of the isocyanurate group is a, the molar amount of the uretdione group is B, the molar amount of the iminooxadiazinedione group is C, and the molar amount of the biuret group is D, D/(a + B + C + D) is 0.50 or more.
(11) A coating composition comprising the polyisocyanate composition described in (10) above and at least one member selected from the group consisting of acrylic polyols having a hydroxyl value of 10mgKOH/g or more and 200mgKOH/g or less and polyester polyols having a hydroxyl value of 10mgKOH/g or more and 200mgKOH/g or less.
(12) A coating film formed by the coating composition of (11) above.
(13) The polyisocyanate composition according to the above (1), which comprises a diisocyanate comprising 1, 6-hexamethylene diisocyanate and a polyisocyanate represented by the following general formula (IV-I),
the content of diisocyanate in the polyisocyanate composition is 0.002 to 0.1 mass%, and
in the above condition 2), the content of the diisocyanate in the polyisocyanate composition is 0.002 mass% or more and 0.1 mass% or less.
(X11-Y11)n11-R11-(NCO)n12(IV-I)
In the above general formula (IV-I), R11Is a residue obtained by removing isocyanate groups from a polyisocyanate derived from at least 1 diisocyanate selected from the group consisting of aliphatic diisocyanates and alicyclic isocyanates, X11Is a residue of a compound having an active hydrogen group and a hydrophilic group, Y11The structure has a bond structure between an isocyanate group and the active hydrogen group, wherein (n11+ n12) is an integer of 2to 10 inclusive, n11 and n12 are both not 0, and n11/(n11+ n12) × 100 is 1to 50 inclusive.
(14) The polyisocyanate composition according to the above (13), wherein the compound having an active hydrogen group and a hydrophilic group is at least one selected from the group consisting of an anionic compound, a cationic compound and a nonionic compound.
(15) The polyisocyanate composition according to the above (14), wherein the compound having an active hydrogen group and a hydrophilic group is the anionic compound,
the anionic compound is at least one selected from the group consisting of a compound having a carboxylic acid group, a compound having a phosphoric acid group, and a compound having a sulfonic acid group.
(16) The polyisocyanate composition according to the above (15), wherein the anionic compound is the compound having a sulfonic acid group,
the compound having a sulfonic acid group is at least one selected from the group consisting of a sulfonic acid having a hydroxyl group and a sulfonic acid having an amino group.
(17) The polyisocyanate composition according to the above (14), wherein the compound having an active hydrogen group and a hydrophilic group is the cationic compound,
the cationic compound is a compound having an amino group and is neutralized with a compound having an anionic group.
(18) The polyisocyanate composition according to the above (14), wherein the compound having an active hydrogen group and a hydrophilic group is the nonionic compound,
the nonionic compound is a polyalkylene glycol ether represented by the following general formula (IV-II).
HO-(R21-O)n21-R22(IV-II)
In the above general formula (IV-II), R21Is alkylene having 1to 4 carbon atoms, R22Is an alkyl group having 1to 8 carbon atoms, and n21 is an integer of 3 to 30 inclusive.
(19) The polyisocyanate composition according to any one of (13) to (18) above, wherein the polyisocyanate has isocyanurate groups and allophanate groups,
the ratio of the molar amount of isocyanurate groups to the total molar amount of isocyanurate groups and allophanate groups in the polyisocyanate composition (isocyanurate groups/(isocyanurate groups + allophanate groups)) is 0.80 or more and less than 0.99.
(20) A coating composition comprising the polyisocyanate composition according to any one of (13) to (19) above and water.
(21) A cured product formed from the coating composition according to (20) above.
(22) A blocked polyisocyanate composition comprising a blocked polyisocyanate and a blocked diisocyanate,
the blocked polyisocyanate is obtained by blocking the isocyanate group of a polyisocyanate derived from an aliphatic diisocyanate containing 1, 6-hexamethylene diisocyanate with a blocking agent,
the content of the blocked diisocyanate is 0.01 to 0.16 mass% based on the total mass of the blocked polyisocyanate composition.
(23) A coating composition comprising the blocked polyisocyanate composition described in (22) above and at least one member selected from the group consisting of acrylic polyols having a hydroxyl value of 10mgKOH/g or more and 200mgKOH/g or less and polyester polyols having a hydroxyl value of 10mgKOH/g or more and 200mgKOH/g or less.
(24) A coating film formed by the coating composition of (23) above.
ADVANTAGEOUS EFFECTS OF INVENTION
The polyisocyanate composition according to embodiment 1 of the present invention contains an isocyanurate polyisocyanate, and is excellent in viscosity stability and color stability, because the odor derived from HDI is suppressed. The coating composition according to embodiment 1 of the present invention contains the polyisocyanate composition as a curing agent for coating, and is excellent in solvent dilutability. The coating film according to embodiment 1 of the present invention is obtained from the coating composition described above, and has good chemical resistance.
The polyisocyanate composition according to embodiment 2 of the present invention has a low viscosity and can form a coating film having excellent adhesion to a recoat, durability when sprayed with brine, and stain resistance. The coating composition according to embodiment 2 of the present invention contains the polyisocyanate composition, and can form a coating film having excellent adhesion to a recoated film, durability when sprayed with brine, and stain resistance. The coating film of embodiment 2 of the present invention is excellent in re-coating adhesion, durability during salt water spraying, and contamination resistance.
According to the polyisocyanate composition of embodiment 3 of the present invention, a coating film having little odor derived from a diisocyanate monomer, excellent adhesion to a substrate, and excellent stain resistance can be formed. The coating composition according to embodiment 3 of the present invention contains the polyisocyanate composition, and can form a coating film having little odor derived from a diisocyanate monomer and excellent adhesion to a substrate and stain resistance. The coating film according to embodiment 3 of the present invention has little odor derived from a diisocyanate monomer and is excellent in adhesion to a substrate and stain resistance.
According to the polyisocyanate composition and the water-based coating composition of embodiment 4 of the present invention, a cured product excellent in hardness and water resistance is obtained. The cured product of the above embodiment is excellent in hardness and water resistance.
According to the blocked polyisocyanate composition of embodiment 5 of the present invention, a coating film excellent in acid resistance and methanol resistance under high temperature conditions can be obtained. The coating composition of the above embodiment contains the blocked polyisocyanate composition, and can give a coating film excellent in acid resistance and methanol resistance under high temperature conditions. The coating film of the above embodiment contains the above coating composition, and is excellent in acid resistance and methanol resistance under high temperature conditions.
Detailed Description
The mode for carrying out the present invention (hereinafter, simply referred to as "the present embodiment") will be described in detail below. The following embodiments are illustrative of the present invention, and the present invention is not limited to the following embodiments. The present invention can be implemented with appropriate modifications within the scope of the gist of the present invention.
In the present specification, the term "polyisocyanate" refers to a reaction product in which a plurality of compounds having 1 or more isocyanate groups (-NCO) are bonded. The compound 1 molecule having 1 or more isocyanate groups (-NCO) constituting the polyisocyanate is sometimes referred to as a monomer (monomer).
In the present specification, "(meth) acrylic acid" includes methacrylic acid and acrylic acid, and "(meth) acrylate" includes methacrylate and acrylate.
The polyisocyanate composition of the present invention satisfies the following conditions 1) and 2) when stored at 50 ℃ for 1 month,
1) the content of 1, 6-hexamethylene diisocyanate ((hereinafter, sometimes simply referred to as "HDI". also sometimes referred to as 1, 6-diisocyanatohexane)) in the polyisocyanate composition before storage is 0.001 mass% or more and 0.1 mass% or less (preferably 0.01 mass% or more and 0.1 mass% or less, more preferably 0.02 mass% or more and 0.1 mass% or less) with respect to the total mass of the polyisocyanate composition before storage;
2) the HDI content in the polyisocyanate composition after storage is 0.001 mass% or more and 0.1 mass% or less (preferably 0.01 mass% or more and 0.1 mass% or less, more preferably 0.02 mass% or more and 0.1 mass% or less) with respect to the total mass of the polyisocyanate composition after storage.
Herein, "before storage" means immediately after the polyisocyanate composition is produced, and "after storage" means the time at which the storage of the polyisocyanate composition at 50 ℃ for 1 month is completed.
When the HDI content before and after storage is not more than the above upper limit, the HDI-derived odor accompanied by irritation is effectively suppressed, and the polyisocyanate composition can be made more excellent in viscosity stability, chromaticity stability, solvent dilutability, and chemical resistance of the obtained coating film.
The HDI content in the polyisocyanate composition of the present embodiment is usually measured by gas chromatography, but in the case of a polyisocyanate composition mainly containing isocyanurate structures, it may be measured by gel permeation chromatography.
The HDI content before storage (initial HDI content) and the HDI content after storage at 50 ℃ for 1 month of the polyisocyanate composition of the present embodiment can be controlled in the above-mentioned appropriate ranges by combining the thin film distillation conditions and the heating conditions after synthesis of the polyisocyanate composition.
Next, the polyisocyanate composition according to embodiment 1 of the present invention will be described.
< polyisocyanate composition (embodiment 1) >
The polyisocyanate composition according to embodiment 1 of the present invention contains a polyisocyanate having isocyanurate groups (hereinafter sometimes referred to as "isocyanurate-type polyisocyanate").
"isocyanurate group" means a functional group derived from a polyisocyanate containing 3 molecules of a diisocyanate monomer, and is a group represented by the following formula (I-I).
Figure BDA0002441845570000121
< polyisocyanate >
[ isocyanurate type polyisocyanate ]
The isocyanurate-type polyisocyanate is a reactant derived from an aliphatic diisocyanate monomer containing 1, 6-Hexamethylene Diisocyanate (HDI). Specifically, an isocyanurate-type polyisocyanate is obtained by reacting a diisocyanate monomer using an alcohol as an isocyanurating catalyst and a co-catalyst.
In the case where the isocyanurate type polyisocyanate is synthesized and purified using the HDI-containing diisocyanate monomer as a raw material for the polyisocyanate composition of the present embodiment, as shown in examples described later, the HDI content in the polyisocyanate composition and the HDI content generated during storage can be controlled so as to fall within specific ranges by combining the thin film distillation conditions and the heat treatment conditions.
As the diisocyanate monomer used for producing the isocyanurate type polyisocyanate, HDI is used, but an aliphatic diisocyanate other than HDI and/or an alicyclic diisocyanate may be used in combination.
The aliphatic diisocyanate other than HDI is preferably an aliphatic diisocyanate having 4 to 30 carbon atoms. Specific examples of the aliphatic diisocyanate include 1, 4-tetramethylene diisocyanate, 1, 5-pentamethylene diisocyanate, 2, 4-trimethyl-1, 6-hexamethylene diisocyanate, lysine diisocyanate, and the like.
The alicyclic diisocyanate is preferably an alicyclic diisocyanate having 8 to 30 carbon atoms. Specific examples of the alicyclic diisocyanate include isophorone diisocyanate (hereinafter referred to as "IPDI"), 1, 3-bis (isocyanatomethyl) -cyclohexane, 4' -dicyclohexylmethane diisocyanate, norbornene diisocyanate, and hydrogenated xylylene diisocyanate, and among them, IPDI is preferable.
Examples of the isocyanuric acid esterification catalyst used for producing the isocyanurate type polyisocyanate include sodium salts, potassium salts, and quaternary ammonium salts of fatty acids.
Examples of the fatty acid include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, and stearic acid. These fatty acids may be linear or branched.
Examples of quaternary ammonium include tetramethylammonium, tetrabutylammonium, butyltrimethylammonium, benzyltrimethylammonium, dibenzyldimethylammonium, and phenyltrimethylammonium.
The amount of the isocyanuric acid esterification catalyst used differs depending on the amounts of the co-catalyst and the solvent used, but may be usually 0.001 mass% or more and 0.05 mass% or less with respect to the mass of HDI.
As the alcohol as the co-catalyst, for example, a phenolic hydroxyl compound or an alcoholic hydroxyl compound can be used. Thereby, the isocyanuric acid esterification reaction further easily proceeds.
Examples of the phenolic hydroxyl compound include phenol, cresol, trimethylphenol and the like.
Examples of the alcoholic hydroxyl compound include a linear alcohol, a branched alcohol, a cyclic alcohol, and a polyhydric alcohol.
Examples of the linear alcohol include methanol, ethanol, propanol, n-butanol, and 1-hexanol.
Examples of the branched alcohol include isobutanol and 2-ethylhexanol.
Examples of the cyclic alcohol include cyclohexanol.
Examples of the polyhydric alcohol include ethylene glycol.
The amount of the alcohol used correlates with the amount of allophanate groups of the polyisocyanate contained in the polyisocyanate composition of the present embodiment. The amount of the alcohol to be used is preferably 500ppm or more and 30000ppm or less in terms of a mass ratio to HDI. When the amount of the alcohol used is not more than the upper limit value, the ratio of the isocyanurate groups of the polyisocyanate contained in the final polyisocyanate composition of the present embodiment is appropriately maintained, and the weather resistance and the chemical resistance are further improved. On the other hand, when the amount of the alcohol is not less than the lower limit, the reaction rate is kept higher, and the productivity is improved from the economical viewpoint.
In the production of the isocyanurate type polyisocyanate, the alcohol may be added as the timing of addition so that the alcohol is present in the reaction system during the isocyanuric acid esterification reaction. Specifically, the isocyanuric acid ester may be added at any time before the isocyanuric acid ester reaction, simultaneously with the isocyanuric acid ester catalyst, or after the addition of the isocyanuric acid ester catalyst has been completed. The timing may be added only at any timing or may be added at all timings. The alcohol may be added by any one of a co-addition method and a continuous addition method. However, from the viewpoint of controlling the reaction and heat generation, the alcohol is preferably added continuously during the isocyanuric acid esterification reaction. The alcohol is preferably added together before the isocyanuric acid esterification reaction from the viewpoint of economy.
The isocyanuric acid esterification reaction temperature is preferably 70 ℃ or lower, more preferably 30 ℃ or higher and 65 ℃ or lower. When the isocyanuric acid esterification reaction temperature is not more than the above upper limit, a polyisocyanate having a further good color can be obtained. On the other hand, when the isocyanuric acid esterification reaction temperature is not lower than the lower limit value, a more appropriate reaction rate is maintained, and a more favorable productivity is obtained from the economical viewpoint.
The reaction time varies depending on the amount of the catalyst, the amount and the method of adding the alcohol as the co-catalyst, the reaction temperature, and the like, but may be usually 1 hour or more and 6 hours or less.
Since the decrease in the content of isocyanate groups (NCO%) accompanying the progress of isocyanuric acid esterification can be measured by titrimetric analysis, the reaction may be stopped when a predetermined NCO% is formed.
The NCO%, viscosity, etc. of the isocyanurate type polyisocyanate can be freely changed by the NCO% at the time of reaction termination.
As the reaction terminator, an acidic compound can be used. Examples of the acidic compound include hydrochloric acid, phosphoric acid, dimethyl phosphate, diethyl phosphate, dibutyl phosphate, di-2-ethylhexyl phosphate, dicyclohexyl phosphate, p-toluenesulfonic acid, benzenesulfonic acid, alkylbenzenesulfonic acid, acetyl chloride, and benzoyl chloride. In addition, analogous compounds to these acidic compounds may also be used.
The amount of the reaction terminator to be used may be 0.5-fold by mol to 10-fold by mol, preferably 1-fold by mol to 8-fold by mol, based on 1 mol of the carboxylic acid content in the isocyanuric acid esterification catalyst. When a reaction terminator soluble in the mixed solution of the diisocyanate monomer as the raw material and the polyisocyanate produced in the reaction is used, the amount of the reaction terminator may be about 1-fold molar amount based on the carboxylic acid content in the isocyanuric acid esterification catalyst, and when an insoluble reaction terminator is used, the amount of the reaction terminator may be 2-fold molar amount or more and 8-fold molar amount or less based on the carboxylic acid content in the isocyanuric acid esterification catalyst.
After the reaction terminator is charged, the reaction may be completely stopped by heating for aging. When the reaction mixture is heated for aging, the temperature is preferably 80 ℃ to 150 ℃, more preferably 80 ℃ to 130 ℃, and still more preferably 90 ℃ to 120 ℃. When the temperature is not more than the above upper limit, the reduction of 1-nylon bodies in the polyisocyanate composition containing the obtained isocyanurate type polyisocyanate can be further suppressed, and further the reduction of the color number and the increase of the viscosity due to the progress of the polymerization of the isocyanurate type polyisocyanate can be further suppressed. When the temperature is not less than the lower limit, the growth of the salt produced by the reaction can be made faster, and particularly in the case of a combination of a catalyst forming an insoluble salt and a reaction terminator, the salt can be formed in a size capable of being filtered, and therefore, more favorable productivity can be achieved from the economical viewpoint.
The time for the heat aging varies depending on the temperature, and may be 10 minutes to 120 minutes, preferably 10 minutes to 90 minutes, more preferably 10 minutes to 60 minutes. Although depending on the temperature, the passage time is not more than the above upper limit, and coloring and high viscosity due to further increase in the amount of polyisocyanate can be further suppressed. When the passage time is not less than the lower limit, the formation and growth of salts can be more sufficient, and in the case of insoluble salts, the separation by filtration can be made easier.
In general, when a large amount of polycyclic products containing not less than 3 trimers of diisocyanate monomers are present in a polyisocyanate composition, the compatibility with a solvent is lowered to cause cloudiness, in addition to problems in physical properties such as viscosity and hardness. Therefore, the reaction can be controlled so that the content of isocyanate groups (NCO%) in the solution of the reaction product after distillation is about 20 mass% by using the reaction terminator.
The HDI content in the product can be determined by gas chromatography. In addition, the trimer content in the product clearly appears around the molecular weight 504 by liquid chromatography, and therefore, it can be quantified. Further, the isocyanurate group content was 1680cm by infrared absorption spectrum-1A clear absorption occurs and can therefore be quantified.
The content of polycyclic compounds in the product can also be quantified in the same manner as for trimers.
In addition, the content of dimer in the product was 1780cm by infrared absorption spectrum-1A clear absorption occurs and can therefore be quantified.
Further, as a method for producing an isocyanurate type polyisocyanate, a polyol adduct obtained by urethanizing a part of HDI can be used, and isocyanation can be performed under the same conditions as described above as a preferable method.
The urethanization reaction to form the polyol adduct may be carried out by a known method. Specifically, the polyol is first added to HDI, and the reaction temperature may be 100 ℃ or lower, preferably 70 ℃ or higher and 90 ℃ or lower, and the reaction time may be about 2 hours. Thus, a polyol adduct can be obtained. When the reaction temperature is not higher than the upper limit, coloration and side reactions of the obtained product can be further suppressed.
The polyol used for urethanization is preferably a 2-functional or 3-functional polyol having a number average molecular weight of 3000 or less. Specific examples of the polyol include a diol (diol), a triol (triol), a polyester polyol, and a polyether polyol.
Examples of the dihydric alcohol include ethylene glycol, diethylene glycol, 1, 3-butanediol (hereinafter, may be abbreviated as "1, 3-BG"), 1, 4-butanediol, propylene glycol, dipropylene glycol, neopentyl glycol, and 1, 6-hexanediol (hereinafter, may be abbreviated as "1, 6-HG").
Examples of the trihydric alcohol include glycerin, trimethylolethane, and trimethylolpropane.
These polyols may be used singly or in combination of 2 or more.
The isocyanurate polyisocyanate obtained by the above production method may be used as it is as the polyisocyanate composition of the present embodiment, or the isocyanurate polyisocyanate may be used after purification. Among them, from the viewpoint of ease of production, the isocyanurate-type polyisocyanate obtained by the above production method is preferably used as it is as the polyisocyanate composition of the present embodiment.
The HDI content in the polyisocyanate composition of the present embodiment preferably satisfies the following conditions 1a), 2a), and 3), and more preferably satisfies the following condition 1b), when stored at 50 ℃ for 1 month.
1a) The HDI content in the polyisocyanate composition before storage is 0.01 to 0.1 mass%;
2a) the HDI content in the polyisocyanate composition after storage is 0.01 to 0.1 mass%;
3) the difference in HDI content between the polyisocyanate compositions before and after storage (hereinafter sometimes referred to as "Δ HDI") was 0.08% by mass or less.
1b) The HDI content in the polyisocyanate composition before storage is 0.01 to 0.08% by mass.
The upper limit value of the HDI content in the polyisocyanate composition before storage is 0.1 mass%, more preferably 0.08 mass%, and still more preferably 0.05 mass%.
The upper limit of the HDI content in the polyisocyanate composition after storage was 0.1 mass%.
Further, the upper limit value of Δ HDI is preferably 0.08% by mass, and more preferably 0.06% by mass.
When the HDI content before and after storage and Δ HDI are not more than the above upper limit value, the HDI-derived odor accompanied by irritation can be more effectively suppressed, and the polyisocyanate composition can be more excellent in viscosity stability, chromaticity stability, solvent dilutability, and chemical resistance of the obtained coating film.
The HDI content in the polyisocyanate composition of the present embodiment can be measured by the method described in the examples described later.
The HDI content before storage (initial HDI content), the HDI content after storage at 50 ℃ for 1 month, and Δ HDI of the polyisocyanate composition of the present embodiment can be controlled to the above-mentioned appropriate ranges by combining the thin film distillation conditions and the heating conditions after the synthesis of the polyisocyanate composition.
(thin film distillation step)
The thin film distillation step is a step for improving the separation efficiency of the low-boiling component from the high-boiling component. As a specific countermeasure, for example, a reduction in the flow rate to increase the residence time, an increase in the temperature during distillation, an increase in the wiper rotation speed, an increase in the number of times of distillation, and the like are considered, and any of them can be selected. Among them, a method of increasing the number of times of distillation is preferable for the purpose of reducing the heat history and improving the separation efficiency. The number of times of distillation is preferably 1to 5 times.
(Heat treatment Process)
In addition, the polyisocyanate composition of the present embodiment preferably not only reduces the initial HDI content but also maintains the HDI content in a small amount after storage at 50 ℃ for 1 month. Therefore, the heat treatment step is preferably performed.
The lower limit of the heat treatment temperature is preferably 60 ℃, more preferably 80 ℃, still more preferably 100 ℃, and particularly preferably 110 ℃.
The upper limit of the heat treatment temperature is preferably 200 ℃, more preferably 180 ℃, still more preferably 160 ℃, and particularly preferably 150 ℃.
The heat treatment temperature is preferably 60 ℃ or more and 200 ℃ or less, more preferably 80 ℃ or more and 180 ℃ or less, further preferably 100 ℃ or more and 160 ℃ or less, and particularly preferably 110 ℃ or more and 150 ℃ or less.
When the heat treatment temperature is not lower than the lower limit, the heat treatment step time can be shortened, and when the heat treatment temperature is not higher than the upper limit, the coloring of the polyisocyanate composition can be further suppressed.
The lower limit of the heat treatment time is preferably 0.2 hours, more preferably 0.5 hours, further preferably 0.7 hours, and particularly preferably 1.0 hour.
The upper limit of the heat treatment time is preferably 6 hours, more preferably 5 hours, still more preferably 4 hours, and particularly preferably 3 hours.
The heat treatment time is preferably 0.2 hours or more and 6 hours or less, more preferably 0.5 hours or more and 5 hours or less, further preferably 0.7 hours or more and 4 hours or less, and particularly preferably 1.0 hour or more and 3 hours or less.
In addition, the heat treatment step is preferably performed under a nitrogen atmosphere or under reduced pressure, and more preferably under reduced pressure, from the viewpoint of suppressing coloring of the polyisocyanate composition, reducing Δ HDI, and the like.
In order to suppress the decomposition of the polyisocyanate into the diisocyanate monomer, it is preferable to perform the heat treatment step, the thin film distillation step to reduce the concentration of the diisocyanate monomer, the heat treatment step again, and the thin film distillation step again.
By performing the above treatment, the initial HDI content can be suppressed to be lower, and the HDI content after 1 month of storage at 50 ℃ can be further reduced.
The heat treatment step and the thin film distillation step are preferably performed in a kit. In addition, the temperature in the thin film distillation step which is finally performed is preferably lower than the heat treatment temperature in the immediately preceding heat treatment step, from the viewpoint of suppressing the HDI content immediately after production to be lower.
By combining the control methods using the above-described heat treatment process and the above-described thin film distillation process, the initial HDI content, the HDI content after storage at 50 ℃ for 1 month, and Δ HDI can be controlled to appropriate ranges. Thus, a polyisocyanate composition having excellent color stability and viscosity stability when stored at 50 ℃ for 1 month was obtained. In addition, when the polyisocyanate composition is formed into a coating, clouding upon dilution with a solvent can be suppressed. Further, the chemical resistance of the coating film obtained from the coating composition can be improved.
[ other polyisocyanates ]
The polyisocyanate contained in the polyisocyanate composition of the present embodiment may have at least one selected from the group consisting of a uretdione group, an iminooxadiazine dione group and an allophanate group in addition to the isocyanurate group.
The "uretdione group" refers to a functional group derived from a polyisocyanate containing 2 molecules of a diisocyanate monomer, and is a group represented by the following formula (I-II).
Figure BDA0002441845570000201
"iminooxadiazinedione group" refers to a functional group derived from a polyisocyanate containing 3 molecules of a diisocyanate monomer, and is a group represented by the following formula (I-III).
Figure BDA0002441845570000202
The "allophanate group" refers to a functional group formed from a hydroxyl group and an isocyanate group of an alcohol, and is a group represented by the following formula (I-IV).
Figure BDA0002441845570000211
(polyisocyanate having uretdione group)
The polyisocyanate having a uretdione group (uretdione group-containing polyisocyanate) is obtained by using a uretdione reaction catalyst.
The uretdionization catalyst is not limited to the following, and examples thereof include tertiary phosphines such as trialkylphosphine, tris (dialkylamino) phosphine, and cycloalkylphosphine.
Examples of the trialkylphosphine include tri-n-butylphosphine and tri-n-octylphosphine.
Examples of the tris (dialkylamino) phosphine include tris (dialkylamino) phosphine such as tris (dimethylamino) phosphine, and the like.
Examples of the cycloalkylphosphine include cyclohexyl-di-n-hexylphosphine and the like.
Many of these compounds also promote the isocyanuric esterification reaction, and in addition to the uretdione group-containing polyisocyanate, an isocyanurate type polyisocyanate is also produced.
At the time of attaining a desired yield, a deactivator of a uretdionization catalyst such as phosphoric acid or methyl p-toluenesulfonate is added to stop the uretdionization reaction.
The amount of the uretdione reaction catalyst used is preferably 10ppm to 10000ppm, more preferably 10ppm to 1000ppm, and still more preferably 10ppm to 500ppm, in terms of a mass ratio, relative to the diisocyanate as a raw material.
The lower limit of the reaction temperature for uretdione reaction is preferably 20 ℃, more preferably 25 ℃, still more preferably 30 ℃, and particularly preferably 35 ℃.
The upper limit of the reaction temperature for uretdione is preferably 120 ℃, more preferably 110 ℃, still more preferably 100 ℃, and particularly preferably 90 ℃.
The reaction temperature of uretdione is preferably 20 ℃ or more and 120 ℃ or less, more preferably 25 ℃ or more and 110 ℃ or less, further preferably 30 ℃ or more and 100 ℃ or less, and particularly preferably 35 ℃ or more and 90 ℃ or less.
When the reaction temperature of uretdione is not more than the above upper limit, changes in the properties of the obtained polyisocyanate composition such as coloration can be more effectively prevented.
Alternatively, a polyisocyanate containing a uretdione group may be obtained by heating a diisocyanate monomer without using the uretdione reaction catalyst.
When the uretdione reaction catalyst is not used, the lower limit of the heating temperature of the diisocyanate monomer is preferably 120 ℃, more preferably 130 ℃, still more preferably 140 ℃, and particularly preferably 145 ℃.
The upper limit of the heating temperature of the diisocyanate monomer is preferably 180 ℃, more preferably 175 ℃, still more preferably 170 ℃, and particularly preferably 165 ℃.
The heating temperature of the diisocyanate monomer is preferably 120 ℃ or higher and 180 ℃ or lower, more preferably 130 ℃ or higher and 175 ℃ or lower, further preferably 140 ℃ or higher and 170 ℃ or lower, and particularly preferably 145 ℃ or higher and 165 ℃ or lower.
When the uretdione reaction catalyst is not used, the lower limit of the heating time is preferably 0.2 hours, more preferably 0.4 hours, still more preferably 0.6 hours, particularly preferably 0.8 hours, and most preferably 1.0 hour.
The upper limit of the heating time is preferably 8 hours, more preferably 6 hours, further preferably 4 hours, particularly preferably 3 hours, and most preferably 2 hours.
The heating time is preferably 0.2 hours or more and 8 hours or less, more preferably 0.4 hours or more and 6 hours or less, further preferably 0.6 hours or more and 4 hours or less, particularly preferably 0.8 hours or more and 3 hours or less, and most preferably 1.0 hour or more and 2 hours or less.
When the heating time is not less than the lower limit, a lower viscosity can be obtained, and when the heating time is not more than the upper limit, the polyisocyanate itself can be further inhibited from being colored.
When the polyisocyanate composition of the present embodiment is obtained without using a uretdione reaction catalyst, it is preferable to remove the unreacted diisocyanate monomer from the viewpoints of, for example, a decrease in the concentration of the unreacted diisocyanate monomer, a decrease in the rate of change in the molecular weight of the obtained polyisocyanate composition after storage, and a decrease in the yellowing property during high-temperature sintering after the uretdione reaction and the isocyanurate reaction are completed only by heating.
(polyisocyanate having iminooxadiazinedione group)
The polyisocyanate having an iminooxadiazinedione group (polyisocyanate containing an iminooxadiazinedione group) is obtained by using an iminooxadiazinedione reaction catalyst.
Examples of the iminooxadiazinedionization catalyst include the following.
(1) General formula M [ F ]n]Or general formula M [ F ]n(HF)m](poly) hydrogen fluoride (in the formula, M and n are integers satisfying the relationship that M/n > 0, M is an n-charged cation (mixture) or 1 or more radicals having a total valence of n.)
Specific examples of the compound ((poly) hydrogen fluoride) of (1) include tetramethylammonium fluoride hydrate and tetraethylammonium fluoride.
(2) Comprising the general formula R1-CR’2-C (O) O-or of the formula R2A compound represented by CR' -c (O) O-, and a compound of a quaternary ammonium cation or a quaternary phosphonium cation. (in the formula, R1And R2Optionally a branched, cyclic and/or unsaturated perfluoroalkyl group having 1to 30 carbon atoms, and R' are the same or different and are selected from the group consisting of a hydrogen atom, an alkyl group having 1to 20 carbon atoms and an aryl group, and optionally a heteroatom. )
Specific examples of the compound (2) include 3,3, 3-trifluorocarboxylic acid; 4,4,4,3, 3-pentafluorobutyric acid; 5,5,5,4,4,3, 3-heptafluoropentanoic acid; 3, 3-difluoroprop-2-enoic acid and the like.
The lower limit of the amount of the iminooxadiazinedionization catalyst is not particularly limited, but is preferably 5ppm, more preferably 10ppm, and still more preferably 20ppm in terms of a mass ratio to HDI as a raw material, from the viewpoint of reactivity and the like.
The upper limit of the amount of the iminooxadiazinedionization catalyst is preferably 5000ppm, more preferably 2000ppm, and still more preferably 500ppm by mass relative to HDI as a raw material, from the viewpoints of coloration and discoloration inhibition of the product, reaction control, and the like.
The amount of the iminooxadiazinedione catalyst to be used is preferably 5ppm or more and 5000ppm or less, more preferably 10ppm or more and 2000ppm or less, and further preferably 20ppm or more and 500ppm or less in terms of a mass ratio with respect to HDI as a raw material.
The lower limit of the reaction temperature of iminooxadiazinedione is not particularly limited, but is preferably 40 ℃, more preferably 50 ℃, and still more preferably 60 ℃ from the viewpoint of the reaction rate and the like.
The upper limit of the reaction temperature of iminooxadiazinedione is preferably 150 ℃, more preferably 120 ℃, and even more preferably 110 ℃ from the viewpoint of suppressing coloration and discoloration of the product.
The reaction temperature of iminooxadiazinedione is preferably 40 ℃ or more and 150 ℃ or less, more preferably 50 ℃ or more and 120 ℃ or less, and further preferably 60 ℃ or more and 110 ℃ or less.
The iminooxadiazinedionization reaction can be stopped at the point when the iminooxadiazinedione reaction reaches the desired content of iminooxadiazinedione groups. The iminooxadiazinedionization reaction can be stopped by, for example, adding an acidic compound such as phosphoric acid, an acid phosphate, sulfuric acid, hydrochloric acid, or a sulfonic acid compound to the reaction solution. Thereby, the iminooxadiazinedionization catalyst is inactivated by neutralization, thermal decomposition, chemical decomposition, or the like. After the reaction was stopped, filtration was performed as needed.
(polyisocyanates having allophanate groups)
The polyisocyanate having an allophanate group (allophanate group-containing polyisocyanate) is obtained by using an alcohol compound or the like in combination with HDI and using an allophanatization reaction catalyst.
The alcohol compound used for producing the allophanate group-containing polyisocyanate is not limited to the following, but is preferably an alcohol formed only of carbon, hydrogen and oxygen. The alcohol compound preferably has a number average molecular weight of 200 or less.
Examples of the alcohol compound include monohydric alcohol and dihydric alcohol.
Examples of the monohydric alcohol include methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, and nonanol.
Examples of the diol include ethylene glycol, 1, 3-butanediol, neopentyl glycol, and 2-ethylhexanediol.
These alcohol compounds may be used alone or in combination of 2 or more.
Among these, the alcohol compound is preferably a monohydric alcohol.
The amount of the alcohol compound to be used is not limited to the following, but is preferably 10/1 or more and 1000/1 or less, more preferably 100/1 or more and 1000/1 or less, in terms of a molar ratio of the isocyanate group of HDI to the hydroxyl group of the alcohol compound. When the amount is not less than the lower limit, the average number of isocyanate groups in the obtained polyisocyanate can be ensured to be a more suitable number.
The allophanation reaction catalyst is not limited to the following, and examples thereof include alkylcarboxylates of tin, lead, zinc, bismuth, zirconium, zirconyl, and the like.
Examples of the tin alkylcarboxylate (organotin compound) include tin 2-ethylhexanoate and dibutyltin dilaurate.
Examples of the alkyl carboxylate of lead (organolead compound) include lead 2-ethylhexanoate and the like.
Examples of the zinc alkylcarboxylate (organozinc compound) include zinc 2-ethylhexanoate and the like.
Examples of the alkyl carboxylate of bismuth include bismuth 2-ethylhexanoate and the like.
Examples of the alkyl carboxylate of zirconium include zirconium 2-ethylhexanoate and the like.
Examples of the alkyl carboxylate of zirconyl include zirconyl 2-ethylhexanoate and the like.
At the time of attaining the desired yield, the allophanatization reaction can be stopped by adding a deactivator of allophanatization reaction catalyst such as phosphoric acid or methyl p-toluenesulfonate.
The amount of the allophanatization reaction catalyst used is preferably 10ppm to 10000ppm, more preferably 10ppm to 1000ppm, and still more preferably 10ppm to 500ppm, in terms of a mass ratio, relative to the diisocyanate as a raw material.
The lower limit of the reaction temperature for allophanatization is preferably 60 ℃, more preferably 70 ℃, still more preferably 80 ℃, and particularly preferably 90 ℃.
The upper limit of the allophanatization reaction temperature is preferably 160 ℃, more preferably 155 ℃, still more preferably 150 ℃, and particularly preferably 145 ℃.
The allophanatization reaction temperature is preferably 60 ℃ to 160 ℃, more preferably 70 ℃ to 155 ℃, still more preferably 80 ℃ to 150 ℃, and particularly preferably 90 ℃ to 145 ℃.
When the allophanatization reaction temperature is not higher than the above upper limit, the resulting polyisocyanate can be more effectively prevented from changing in properties such as coloration.
The lower limit of the reaction time is preferably 0.2 hour, more preferably 0.4 hour, still more preferably 0.6 hour, particularly preferably 0.8 hour, and most preferably 1.0 hour.
The upper limit of the reaction time is preferably 8 hours or less, more preferably 6 hours, still more preferably 4 hours, particularly preferably 3 hours, and most preferably 2 hours.
The reaction time for allophanatization is preferably 0.2 hours or more and 8 hours or less, more preferably 0.4 hours or more and 6 hours or less, still more preferably 0.6 hours or more and 4 hours or less, particularly preferably 0.8 hours or more and 3 hours or less, and most preferably 1.0 hour or more and 2 hours or less.
When the reaction time for allophanatization is not less than the lower limit, a lower viscosity can be obtained, and when the reaction time is not more than the upper limit, the coloring of the polyisocyanate itself can be further suppressed.
In addition, the above-mentioned isocyanuric acid esterification reaction catalyst may be used as the allophanation reaction catalyst. When the allophanatization reaction is carried out using the above-mentioned isocyanurate-forming catalyst, an isocyanurate-type polyisocyanate is also produced at the same time. Among them, from the viewpoint of improving productivity from the economical viewpoint, it is preferable to use the above-mentioned isocyanurate-forming reaction catalyst as an allophanation reaction catalyst to carry out an allophanation reaction and an isocyanurate reaction.
The isocyanuric acid esterification reaction and the uretdione reaction may be carried out separately or simultaneously.
In addition, since the production process can be simplified when an allophanatization reaction is involved, it is preferable to simultaneously perform an isocyanuric acid esterification reaction and an allophanatization reaction, and then perform a uretdionization reaction.
The allophanatization reaction can be stopped at the moment the desired allophanate group content is reached.
The allophanatization reaction is not limited to the following, and can be stopped by adding an acidic compound such as phosphoric acid, acid phosphate, sulfuric acid, hydrochloric acid, or a sulfonic acid compound to the reaction solution. Thus, the allophanatization reaction catalyst is inactivated by neutralization, thermal decomposition, chemical decomposition, or the like. After the reaction was stopped, filtration was performed as needed.
< coating composition (embodiment 1) >
The polyisocyanate composition of embodiment 1 can be suitably used as a curing agent for a coating composition, etc.
The coating composition according to embodiment 1 of the present invention contains the polyisocyanate composition.
< resin component >
The coating composition of the present embodiment further contains a resin component as a main agent. The resin component is not particularly limited, but preferably contains a compound containing 2 or more active hydrogens reactive with isocyanate groups in the molecule.
The compound having 2 or more active hydrogens in the molecule is not limited to the following, and examples thereof include polyols, polyamines, and polythiols. Among these, the compound having 2 or more active hydrogens in the molecule is preferably a polyol. The polyol is not limited to the following, and examples thereof include polyester polyol, polyether polyol, acrylic polyol, polyolefin polyol, fluorine polyol, and the like.
The coating composition of the present embodiment can be used for any of solvent-based substrates, water-based substrates, and solvent-free substrates.
In the case of a solvent-based coating composition, for example, a resin containing a compound having 2 or more active hydrogens in the molecule or a solvent dilution thereof is first prepared by adding other resins, catalysts, pigments, leveling agents, antioxidants, ultraviolet absorbers, light stabilizers, plasticizers, surfactants, and other additives as needed. Subsequently, the polyisocyanate composition of the present embodiment is added as a curing agent, and a solvent is further added as necessary to adjust the viscosity. Subsequently, the solvent-based coating composition can be obtained by stirring by hand or using a stirring machine such as Mazelar.
In the case of forming a coating composition for an aqueous base, for example, a coating composition is first produced by adding, as necessary, other resins, catalysts, pigments, leveling agents, antioxidants, ultraviolet absorbers, light stabilizers, plasticizers, surfactants and other additives to an aqueous dispersion or aqueous solution of a resin containing a compound having 2 or more active hydrogens in the molecule. Subsequently, the polyisocyanate composition of the present embodiment is added as a curing agent, and water and a solvent are added as necessary. Then, the mixture was forcibly stirred by a stirring machine, whereby a water-based coating composition was obtained.
[ polyester polyol ]
The polyester polyol can be obtained by, for example, subjecting a mixture of 2 or more types of dibasic acids and a mixture of 2 or more types of polyhydric alcohols to condensation reaction.
Examples of the dibasic acid include carboxylic acids such as succinic acid, adipic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, and 1, 4-cyclohexanedicarboxylic acid.
Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, diethylene glycol, 1, 4-butanediol, neopentyl glycol, 1, 6-hexanediol, trimethylpentanediol, cyclohexanediol, trimethylolpropane, glycerol, pentaerythritol, 2-hydroxymethylpropanediol, and ethoxylated trimethylolpropane.
Specific examples of the method for producing the polyester polyol include a condensation reaction by mixing the above components and heating the mixture at about 160 to 220 ℃.
Or polycaprolactones obtained by ring-opening polymerization of lactones such as epsilon-caprolactone with a polyol, for example, can be used as the polyester polyol.
The polyester polyol obtained by the above production method can be modified using aromatic diisocyanate, aliphatic diisocyanate, alicyclic diisocyanate, compounds obtained therefrom, and the like. Among them, the polyester polyol is preferably modified with an aliphatic diisocyanate, an alicyclic diisocyanate, and a compound obtained therefrom, from the viewpoint of weather resistance, yellowing resistance, and the like of the obtained coating film.
When the coating composition of the present embodiment contains a solvent having a large water content, a part of carboxylic acid such as dibasic acid in the polyester polyol remains in advance, and the carboxylic acid is neutralized with a base such as amine or ammonia, whereby the polyester polyol can be made into a water-soluble or water-dispersible resin.
[ polyether polyol ]
The polyether polyol can be obtained by any of the following methods (1) to (3), for example.
(1) A process for obtaining polyether polyols by random or block addition of alkylene oxides, alone or in mixtures, to polyhydroxy compounds, alone or in mixtures, using catalysts.
Examples of the catalyst include hydroxides (lithium, sodium, potassium, etc.), strongly basic catalysts (alkoxides, alkylamines, etc.), complex metal cyanide complexes (metalloporphyrin, zinc hexacyanocobaltate complex, etc.), and the like.
Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, cyclohexene oxide, and styrene oxide.
(2) A method for producing a polyether polyol by reacting a polyamine compound with an alkylene oxide.
Examples of the polyamine compound include ethylenediamine and the like.
The alkylene oxide may be the same as the one exemplified in the method (1).
(3) A method of polymerizing acrylamide or the like using the polyether polyol obtained in (1) or (2) as a medium to obtain a so-called polymer polyol.
The polyol used in the above method (1) may be, for example, those shown in the following (i) to (vi).
(i) Diglycerol, ditrimethylolpropane, pentaerythritol, dipentaerythritol, and the like.
(ii) Sugar alcohol compounds such as erythritol, D-threitol, L-arabitol, ribitol, xylitol, sorbitol, mannitol, galactitol, and rhamnose alcohol.
(iii) Monosaccharides such as arabinose, ribose, xylose, glucose, mannose, galactose, fructose, sorbose, rhamnose, fucose, and deoxyribose.
(iv) Disaccharides trehalose, sucrose, maltose, cellobiose, gentiobiose, lactose, melibiose, and the like.
(v) Raffinose, gentianose, melezitose and the like.
(vi) Stachyose and other tetrasaccharides.
[ acrylic polyol ]
The acrylic polyol can be obtained by, for example, polymerizing only a polymerizable monomer having 1 or more active hydrogens in one molecule, or copolymerizing a polymerizable monomer having 1 or more active hydrogens in one molecule and, if necessary, another monomer copolymerizable with the polymerizable monomer.
Examples of the polymerizable monomer having 1 or more active hydrogens in one molecule include polymerizable monomers shown in the following (i) to (vi). These may be used alone or in combination of 2 or more.
(i) Acrylic esters having active hydrogen such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate and the like.
(ii) Methacrylic acid esters having active hydrogen such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 3-hydroxypropyl methacrylate and 4-hydroxybutyl methacrylate.
(iii) (meth) acrylic acid esters having polyvalent active hydrogen such as (meth) acrylic acid monoesters of triols such as glycerin and trimethylolpropane.
(iv) Polyether polyols (e.g., polyethylene glycol, polypropylene glycol, polybutylene glycol, etc.) and monoethers of the above (meth) acrylates having active hydrogen.
(v) Adducts of glycidyl (meth) acrylate and monobasic acids (e.g., acetic acid, propionic acid, p-tert-butylbenzoic acid, etc.).
(vi) An adduct obtained by ring-opening polymerizing a lactone (e.g.,. epsilon. -caprolactam,. gamma. -valerolactone, etc.) to the active hydrogen of the above (meth) acrylate having an active hydrogen.
Examples of the other monomer copolymerizable with the polymerizable monomer include the following monomers (i) to (iv). These may be used alone or in combination of 2 or more.
(i) (meth) acrylates such as methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, lauryl methacrylate and glycidyl methacrylate.
(ii) And unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, and unsaturated amides (acrylamide, N-methylolacrylamide, diacetone acrylamide).
(iii) Vinyl monomers having a hydrolyzable silyl group such as vinyltrimethoxysilane, vinylmethyldimethoxysilane and γ - (meth) acryloylpropyltrimethoxysilane.
(iv) Other polymerizable monomers such as styrene, vinyl toluene, vinyl acetate, acrylonitrile, and dibutyl fumarate.
As a specific method for producing an acrylic polyol, for example, an acrylic polyol can be obtained by solution-polymerizing the above monomers in the presence of a known radical polymerization initiator such as a peroxide or an azo compound, and diluting the resulting product with an organic solvent or the like as necessary.
When the coating composition of the present embodiment contains a solvent having a large water content, it can be produced by a known method such as solution polymerization of the monomer with amine or ammonia to convert the monomer to a water layer, or emulsion polymerization. In this case, water solubility or water dispersibility can be imparted to the acrylic polyol by neutralizing the acidic moiety of a carboxylic acid-containing monomer such as acrylic acid or methacrylic acid, or a sulfonic acid-containing monomer.
[ polyolefin polyol ]
Examples of the polyolefin polyol include polybutadiene having 2 or more hydroxyl groups, hydrogenated polybutadiene having 2 or more hydroxyl groups, polyisoprene having 2 or more hydroxyl groups, hydrogenated polyisoprene having 2 or more hydroxyl groups, and the like.
The number of hydroxyl groups of statistically 1 molecule of the polyolefin polyol (hereinafter, sometimes referred to as "average number of hydroxyl groups") is preferably 2 or more.
[ Fluoropolyol ]
In the present specification, "fluorine polyol" refers to a polyol containing fluorine in the molecule. Specific examples of the fluorine polyol include copolymers of a fluoroolefin, a cyclic vinyl ether, a hydroxyalkyl vinyl ether, and a vinyl ester of a monocarboxylic acid, which are disclosed in, for example, Japanese patent application laid-open No. 57-34107 (reference 1) and Japanese patent application laid-open No. 61-275311 (reference 2).
[ hydroxyl value and acid value of polyol ]
The lower limit of the hydroxyl value of the polyol is preferably 10mgKOH/g, more preferably 20mgKOH/g, and still more preferably 30 mgKOH/g.
The upper limit of the hydroxyl value of the polyol is preferably 200mgKOH/g, more preferably 180mgKOH/g, and still more preferably 160 mgKOH/g.
The hydroxyl value of the polyol is preferably from 10 to 200mgKOH/g, more preferably from 20 to 180mgKOH/g, and still more preferably from 30 to 160 mgKOH/g.
When the hydroxyl value of the polyol is not less than the lower limit, the chemical resistance of the coating film obtained from the coating composition of the present embodiment can be further improved.
When the hydroxyl value of the polyol is not more than the above upper limit, the pot life after mixing with the polyisocyanate composition can be further improved.
In general, the term "effective period" refers to a period of time for ensuring the performance of a composition before curing after the composition is produced by mixing a main agent and a curing agent in a composition such as a coating material or an adhesive. Also known as the age.
The acid value of the polyol is preferably 0mgKOH/g or more and 30mgKOH/g or less.
The hydroxyl value and acid value can be determined according to JIS K1557.
Among them, as the polyol contained in the coating composition of the present embodiment, an acrylic polyol is preferable from the viewpoint of weather resistance, chemical resistance, and hardness. Alternatively, polyester polyols are preferred from the viewpoint of mechanical strength and oil resistance.
That is, the coating composition of the present embodiment preferably contains the polyisocyanate composition of the above embodiment and at least one selected from the group consisting of acrylic polyols having a hydroxyl value of 10mgKOH/g or more and 200mgKOH/g or less and polyester polyols having a hydroxyl value of 10mgKOH/g or more and 200mgKOH/g or less.
[NCO/OH]
The molar ratio (NCO/OH) of the isocyanate group in the polyisocyanate composition of the above embodiment to the hydroxyl group in the compound having 2 or more active hydrogens in the molecule is preferably 0.2 or more and 5.0 or less, more preferably 0.4 or more and 3.0 or less, and still more preferably 0.5 or more and 2.0 or less.
When the NCO/OH ratio is not less than the above lower limit, a stronger coating film tends to be obtained. On the other hand, when the NCO/OH value is not more than the above upper limit value, the smoothness of the coating film tends to be further improved.
< other additives >
The coating composition of the present embodiment may contain, in addition to the polyisocyanate composition and the resin component, a melamine-based curing agent such as a fully alkyl, hydroxymethyl, or imino alkyl group, if necessary.
The compound having 2 or more active hydrogens in the molecule, the polyisocyanate composition of the above embodiment, and the coating composition of the present embodiment may contain an organic solvent.
The organic solvent is not particularly limited, and preferably does not have a functional group reactive with a hydroxyl group and an isocyanate group, and is preferably sufficiently compatible with the polyisocyanate composition. Examples of such an organic solvent include, but are not limited to, ester compounds, ether compounds, ketone compounds, aromatic compounds, ethylene glycol dialkyl ether compounds, polyethylene glycol dicarboxylate compounds, hydrocarbon solvents, and aromatic solvents, which are generally used as coating solvents.
The compound having 2 or more active hydrogens in the molecule, the polyisocyanate composition of the above embodiment, and the coating composition of the present embodiment may be used by mixing various additives used in the art, such as a curing acceleration catalyst, a pigment, a leveling agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a plasticizer, and a surfactant, depending on the purpose and use, within a range not to impair the desired effects of the present embodiment.
Examples of the curing accelerating catalyst include, but are not limited to, metal salts and tertiary amines.
Examples of the metal salt include dibutyl tin dilaurate, tin 2-ethylhexanoate, zinc 2-ethylhexanoate, and cobalt salt.
Examples of the tertiary amine include triethylamine, pyridine, picoline, benzyldimethylamine, N-dimethylcyclohexylamine, N-methylpiperidine, pentamethyldiethylenetriamine, N '-ethanopiperazine, and N, N' -dimethylpiperazine.
Examples of the pigment include titanium oxide, carbon black, indigo, quinacridone, and pearl mica.
The leveling agent is not particularly limited, and examples thereof include silicone, aerosol, wax, stearate, and polysiloxane.
Examples of the antioxidant, ultraviolet absorber, and light stabilizer include aliphatic, aromatic, or alkyl-substituted aromatic esters of phosphoric acid or phosphorous acid, hypophosphorous acid derivatives, phosphorus compounds, phenol derivatives (particularly hindered phenol compounds), sulfur-containing compounds, and tin compounds. They may be contained alone or in an amount of 2 or more.
Examples of the phosphorus compound include phenylphosphonic acid, phenylphosphinic acid, diphenylphosphonic acid, polyphosphonate, dialkylpentaerythritol diphosphite, and dialkylbisphenol A diphosphite.
Examples of the sulfur-containing compound include thioether compounds, dithioate compounds, mercaptobenzimidazole compounds, diphenylthiourea compounds, and thiodipropionate esters.
Examples of the tin-based compound include tin maleate, dibutyltin monooxide, and the like.
The plasticizer is not particularly limited, and examples thereof include phthalic acid esters, phosphoric acid esters, fatty acid esters, pyromellitic acid esters, epoxy plasticizers, polyether plasticizers, liquid rubbers, and non-aromatic paraffin oils.
Examples of the phthalate ester include dioctyl phthalate, dibutyl phthalate, diethyl phthalate, butyl benzyl phthalate, di-2-ethylhexyl phthalate, diisodecyl phthalate, diundecyl phthalate, and diisononyl phthalate.
Examples of the phosphate esters include tricresyl phosphate, triethyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, trimethylhexyl phosphate, tris-chloroethyl phosphate, and tris-dichloropropyl phosphate.
Examples of the fatty acid esters include octyl trimellitate, isodecyl trimellitate, trimellitates, dipentaerythritol esters, dioctyl adipate, dimethyl adipate, di-2-ethylhexyl azelate, dioctyl sebacate, di-2-ethylhexyl sebacate, and acetyl castor oil methyl ester.
Examples of the pyromellitic acid ester include octyl pyromellitate and the like.
Examples of the epoxy plasticizer include epoxidized soybean oil, epoxidized linseed oil, and epoxidized fatty acid alkyl ester.
Examples of the polyether plasticizer include adipic acid ether ester and polyether.
Examples of the liquid rubber include liquid NBR, liquid acrylic rubber, and liquid polybutadiene.
Examples of the surfactant include known anionic surfactants, cationic surfactants, and amphoteric surfactants.
< use >)
The coating composition of the present embodiment is not limited to the following, and is useful as a primer or an upper-middle layer coating material for materials such as metals (steel sheets, surface-treated steel sheets, etc.), plastics, wood, films, and inorganic materials. In addition, the coating composition is also useful as a coating material for imparting aesthetic properties, weather resistance, acid resistance, rust resistance, chipping resistance, and the like to precoated metals including rust-proof steel sheets, automobile coatings, and the like. Further, the urethane composition is useful as a urethane material for adhesives, pressure-sensitive adhesives, elastomers, foams, surface-treating agents, and the like.
< coating film (embodiment 1) >
The coating film according to embodiment 1 of the present invention is formed from the coating composition according to embodiment 1. The coating film of the present embodiment is obtained by applying the coating composition of the above embodiment by, for example, roll coating, curtain coating, spray coating, bell coating, electrostatic coating, or the like, and curing the coating. Therefore, the coating film of the present embodiment always exhibits stable quality and is excellent in chemical resistance.
< polyisocyanate composition (embodiment 2) >
Next, the polyisocyanate composition according to embodiment 2 of the present invention will be described. The same method as in embodiment 1 may not be described.
The polyisocyanate composition according to embodiment 2 of the present invention contains an isocyanurate type polyisocyanate. The "isocyanurate" may be referred to as an isocyanurate 3-mer as described in embodiment 1.
In the polyisocyanate composition of the present embodiment, the lower limit of the ratio of the components having a number average molecular weight of 700 or less is 70% by mass, preferably 72% by mass, more preferably 74% by mass, and still more preferably 76% by mass.
The upper limit of the ratio of the components having a number average molecular weight of 700 or less is preferably 90% by mass, more preferably 86% by mass, and still more preferably 82% by mass.
The ratio of the component having a number average molecular weight of 700 or less in the polyisocyanate composition of the present embodiment is preferably 70% by mass or more and 90% by mass or less, more preferably 72% by mass or more and 86% by mass or less, still more preferably 74% by mass or more and 82% by mass or less, and particularly preferably 76% by mass or more and 82% by mass or less.
The ratio of components having a number average molecular weight of 700 or less can be measured by gel permeation chromatography (hereinafter sometimes simply referred to as "GPC").
Specifically, the lower limit of the HDI content in the polyisocyanate composition after storage is preferably 0.01 mass%, more preferably 0.02 mass%, and still more preferably 0.03 mass%.
The upper limit of the HDI content in the polyisocyanate composition after storage was 0.10 mass%.
The HDI content in the polyisocyanate composition after storage is preferably 0.01% by mass or more and 0.1% by mass or less, more preferably 0.02% by mass or more and 0.1% by mass or less, and still more preferably 0.03% by mass or more and 0.1% by mass or less.
The polyisocyanate composition of the present embodiment has the above technical features, and therefore, it is possible to form a coating film having low viscosity and excellent adhesion to a recoat, durability when sprayed with brine, and stain resistance.
< polyisocyanate >
[ isocyanurate type polyisocyanate ]
The isocyanurate polyisocyanate contained in the polyisocyanate composition of the present embodiment is a reactant derived from an HDI-containing aliphatic diisocyanate monomer, as in embodiment 1.
As the diisocyanate monomer used for producing the isocyanurate type polyisocyanate, HDI is used, and for example, an aliphatic diisocyanate and/or an alicyclic diisocyanate can be used in combination with HDI as in embodiment 1.
The content of the isocyanurate 3-mer in the polyisocyanate composition of the present embodiment is not particularly limited, but is preferably 55% by mass or more and 95% by mass or less, more preferably 60% by mass or more and 95% by mass or less, relative to the total solid content in the polyisocyanate composition.
When the content of the isocyanurate 3-mer is not less than the above lower limit, the viscosity of the polyisocyanate composition of the present embodiment can be further reduced. On the other hand, when the content of the isocyanurate 3-mer is not more than the above upper limit, the yield of the polyisocyanate composition of the present embodiment can be further improved.
The content of isocyanurate 3-mer can be determined by GPC.
[ other polyisocyanates ]
The polyisocyanate contained in the polyisocyanate composition of the present embodiment may further have at least one selected from the group consisting of a uretdione group, an iminooxadiazine dione group and an allophanate group in addition to the isocyanurate group, as in embodiment 1.
(Urea diketone group)
In the polyisocyanate composition of the present embodiment, the lower limit of the molar ratio of the uretdione groups/isocyanurate groups is preferably 0.01, more preferably 0.15, still more preferably 0.2, and particularly preferably 0.3.
The upper limit of the molar ratio of the uretdione groups/isocyanurate groups is preferably 0.5, more preferably 0.45, still more preferably 0.4, particularly preferably 0.38.
The molar ratio of the uretdione group/isocyanurate group is preferably 0.01 or more and 0.5 or less, more preferably 0.15 or more and 0.45 or less, further preferably 0.2 or more and 0.4 or less, and particularly preferably 0.3 or more and 0.38 or less.
When the molar ratio of the uretdione group/isocyanurate group is not less than the lower limit, the viscosity of the polyisocyanate composition of the present embodiment can be further reduced. On the other hand, when the molar ratio of the uretdione group/isocyanurate group is not more than the above upper limit, the crosslinkability can be further improved.
The molar ratio of uretdione groups/isocyanurate groups can be determined by13And C-NMR was measured. Specifically, the measurement can be performed by the method described in the examples described later.
Examples of the method for controlling the molar ratio of the uretdione group/isocyanurate group within the above range include the following methods (1) and (2).
(1) After the isocyanuric acid esterification reaction of HDI was carried out, the catalyst was deactivated. Then, the reaction is carried out at a temperature of 140 ℃ or higher and 160 ℃ or lower (preferably 145 ℃ or higher and 165 ℃ or lower) for several hours (preferably 1 hour or higher and 3 hours or lower). Thereby, the molar ratio of uretdione group/isocyanurate group can be controlled within the above range.
(2) Isocyanurated reaction of HDI was carried out to obtain the 1 st polyisocyanate composition. Subsequently, a uretdionization catalyst such as tertiary phosphine is added. Then, the reaction is carried out at a temperature of about 20 ℃ to 80 ℃ for several hours to several tens of hours to obtain a 2 nd polyisocyanate composition. Next, a portion of the 2 nd polyisocyanate composition is mixed in the 1 st polyisocyanate composition. Thus, the molar ratio of uretdione groups/isocyanurate groups can be controlled within the above range.
Among them, the method shown in the above (1) is preferable from the viewpoint of ease of obtaining and the like.
(Iminooxadiazinedionyl)
The molar ratio of iminooxadiazinedione groups to isocyanurate groups can be determined by the method described in the examples below.
Examples of the method for controlling the molar ratio of iminooxadiazine dione groups/isocyanurate groups include the following methods (1) and (2).
(1) After the isocyanuric acid esterification reaction of HDI was carried out, the catalyst was deactivated. Followed by reaction at a temperature of about 140 ℃ or higher and about 160 ℃ or lower for several hours. The molar ratio iminooxadiazine diketonate/isocyanurate groups can thereby be controlled.
(2) HDI is reacted with a heterocyclic ring-containing phosphorus compound such as 1-butylphospholane as a catalyst at a temperature of about 20 ℃ to 80 ℃ for about several hours to several tens of hours to obtain a 2 nd polyisocyanate composition. Subsequently, a part of the 2 nd polyisocyanate composition is mixed with the polyisocyanate composition obtained in (1). The molar ratio iminooxadiazine diketonate/isocyanurate groups can thereby be controlled.
(allophanate group)
When the molar amount of the isocyanurate groups in the polyisocyanate composition of the present embodiment is a, the molar amount of the uretdione groups is B, the molar amount of the iminooxadiazinedione groups is C, and the molar amount of the allophanate groups is E, a/(a + B + C + E) is not particularly limited, but is preferably 0.1 or more, more preferably 0.25 or more, further preferably 0.4 or more, and particularly preferably 0.5 or more.
A/(A + B + C + E) can be prepared by13And C-NMR was measured. Specifically, the measurement can be performed by the method described in the examples described later.
(other groups)
The polyisocyanate contained in the polyisocyanate composition of the present embodiment may further contain a urethane group, a urea group, a biuret group, a carbodiimide group, or the like, in addition to the above functional groups.
< viscosity >
The lower limit of the viscosity at 25 ℃ of the polyisocyanate composition of the present embodiment is preferably 100 mPas, more preferably 140 mPas, still more preferably 180 mPas, particularly preferably 200 mPas, most preferably 220 mPas.
The upper limit of the viscosity is preferably 1500 mPas, more preferably 1000 mPas, still more preferably 800 mPas, particularly preferably 700 mPas, most preferably 600 mPas.
The viscosity of the polyisocyanate composition of the present embodiment at 25 ℃ is preferably 100 to 1500mPa · s, more preferably 140 to 1000mPa · s, further preferably 180 to 800mPa · s, further preferably 200 to 700mPa · s, and further preferably 220 to 600mPa · s.
When the viscosity is not less than the lower limit, the crosslinking property of the polyisocyanate composition of the present embodiment can be further improved. On the other hand, when the viscosity is not more than the above upper limit, the solid content concentration of the coating composition using the polyisocyanate composition of the present embodiment can be further increased.
The viscosity of the polyisocyanate composition purified to have a nonvolatile content of 99.5 mass% or more can be measured by using an E-type viscometer (manufactured by Tokimec, inc.). Specifically, the measurement can be carried out by the method described in the examples described later.
< content of isocyanate group (NCO content) >)
The lower limit of the content of isocyanate groups (NCO content) in the polyisocyanate composition of the present embodiment is preferably 21% by mass, more preferably 21.5% by mass, and still more preferably 22.0% by mass.
The upper limit of the NCO content is preferably 25% by mass, more preferably 24% by mass, and still more preferably 23.7% by mass.
The NCO content of the polyisocyanate composition of the present embodiment is preferably 21 mass% or more and 25 mass% or less, more preferably 21.5 mass% or more and 24 mass% or less, further preferably 22.0 mass% or more and 23.7 mass% or less, and further preferably 22.0 mass% or more and 23.0 mass% or less.
When the NCO content is not less than the lower limit, the resulting coating film can have more favorable coating film properties such as hardness. On the other hand, when the NCO content is not more than the above upper limit, the yield of the polyisocyanate composition of the present embodiment can be further improved.
The NCO content can be determined by neutralizing the isocyanate group of the polyisocyanate composition of the present embodiment with an excess of 2N amine and then back-titrating with 1N hydrochloric acid.
The NCO content is a value relative to the solid content of the polyisocyanate composition of the present embodiment. The solid content of the polyisocyanate composition can be measured by the nonvolatile content measurement method shown in the examples described later.
< average number of isocyanate groups (average number of NCO groups) >)
The lower limit of the average number of isocyanate groups (average number of NCO groups) in the polyisocyanate composition of the present embodiment is preferably 2.3, more preferably 2.5, and still more preferably 2.7.
The upper limit of the average number of NCO groups is preferably 4.0, more preferably 3.8, still more preferably 3.5, particularly preferably 3.2.
The average number of NCO groups of the polyisocyanate composition of the present embodiment is preferably 2.3 or more and 4.0 or less, more preferably 2.5 or more and 3.8 or less, further preferably 2.7 or more and 3.5 or less, and particularly preferably 2.7 or more and 3.2 or less.
The average number of NCO groups is not less than the lower limit, whereby the crosslinking property of the polyisocyanate composition of the present embodiment can be further improved. On the other hand, when the average number of NCO groups is not more than the above upper limit, the polyisocyanate composition of the present embodiment can be made to have a lower viscosity.
The average number of isocyanate groups in the polyisocyanate composition of the present embodiment can be calculated by the following formula (II-A).
Average number of NCO groups ═ (polyisocyanate number average molecular weight. times. NCO content. times.0.01)/42 (II-A)
< number average molecular weight >
The lower limit of the number average molecular weight of the solid component in the polyisocyanate composition of the present embodiment is preferably 400, more preferably 430, still more preferably 460, and particularly preferably 480.
The upper limit of the number average molecular weight is preferably 1000, more preferably 800, still more preferably 700, and particularly preferably 600.
The number average molecular weight of the solid component in the polyisocyanate composition of the present embodiment is preferably 400 or more and 1000 or less, more preferably 430 or more and 800 or less, further preferably 460 or more and 700 or less, and particularly preferably 480 or more and 600 or less.
When the number average molecular weight is not less than the lower limit value, the yield of the obtained polyisocyanate composition tends to be further improved. On the other hand, when the number average molecular weight is not more than the upper limit value, the gloss of the obtained coating film tends to be further improved.
The number average molecular weight can be determined by GPC as a number average molecular weight based on polystyrene.
< method for producing polyisocyanate composition (embodiment 2) >
Next, a method for producing the polyisocyanate composition according to embodiment 2 of the present invention will be described. The same steps as those in embodiment 1 may not be described.
Method for producing isocyanurate polyisocyanate
Isocyanurate-type polyisocyanate similarly to embodiment 1, an isocyanurate-type polyisocyanate is obtained by reacting a diisocyanate monomer using an isocyanurating catalyst and an alcohol as a co-catalyst.
Method for producing polyisocyanate having uretdione group
The polyisocyanate having a uretdione group (polyisocyanate containing a uretdione group) is obtained by using a uretdione reaction catalyst in the same manner as in embodiment 1.
Method for producing polyisocyanate having iminooxadiazinedione group
The polyisocyanate having an iminooxadiazinedione group (iminooxadiazinedione group-containing polyisocyanate) can be obtained by using an iminooxadiazinedione reaction catalyst in the same manner as in embodiment 1.
< polyisocyanates having allophanate groups >
The polyisocyanate having allophanate groups (allophanate group-containing polyisocyanate) can be obtained by using an allophanation reaction catalyst in combination with an alcohol compound or the like in HDI, as in embodiment 1.
< yield >
In the polyisocyanate composition of the present embodiment, in order to control the ratio of the components having a number average molecular weight of 700 or less within the above range, the lower limit of the yield is preferably 5% by mass, more preferably 10% by mass, and still more preferably 15% by mass.
The upper limit of the yield is preferably 40% by mass, more preferably 35% by mass, and still more preferably 30% by mass.
The yield is preferably 5% by mass or more and 40% by mass or less, more preferably 10% by mass or more and 35% by mass or less, and further preferably 15% by mass or more and 30% by mass or less.
When the yield is not less than the lower limit, the productivity can be further improved. On the other hand, when the yield is not more than the above upper limit, the ratio of the component having the number average molecular weight of not more than 700 can be further increased.
In order to control the ratio of the components having a number average molecular weight of 700 or less within the above range, the polyisocyanate composition of the present embodiment preferably contains a polyisocyanate having a uretdione group and an allophanate group.
< thin film distillation step and Heat treatment step >
The reaction liquid immediately after the reaction is stopped usually contains a diisocyanate monomer such as unreacted HDI, and therefore it is preferable to remove it by a thin film evaporator, extraction, or the like.
In the polyisocyanate composition of the present embodiment, in order to control the HDI content after storage to the above upper limit value or less when stored at 50 ℃ for 1 month, it is preferable to perform ordinary thin film distillation 1 or more times and 4 or less times and repeat thin film distillation and heat treatment 2 or more times and 4 or less times, respectively.
[ thin film distillation Process ]
The thin film distillation step is a step for improving the separation efficiency of the low-boiling component from the high-boiling component, and is performed by the same method as in embodiment 1.
[ Heat treatment Process ]
In addition, when the polyisocyanate composition of the present embodiment is stored at 50 ℃ for 1 month, it is preferable to not only reduce the HDI content before storage (hereinafter, sometimes referred to as "initial HDI content") but also maintain the HDI content after storage in a small amount. Therefore, the heat treatment step is preferably performed by the same method as in embodiment 1.
In addition, in order to suppress the decomposition of the polyisocyanate into the diisocyanate monomer, it is preferable to perform the thin film distillation step after the heat treatment step, reduce the concentration of the diisocyanate monomer, perform the heat treatment step again, and then perform the thin film distillation step again, as in embodiment 1.
By performing the above treatment, the initial HDI content can be suppressed to be lower, and the HDI content after 1 month of storage at 50 ℃ can be further reduced.
The initial HDI content in the polyisocyanate composition of the present embodiment is 0.10% by mass or less, more preferably 0.08% by mass or less, still more preferably 0.06% by mass or less, and particularly preferably 0.05% by mass or less.
When the initial HDI content is not more than the above upper limit value, the toxicity of the polyisocyanate composition of the present embodiment can be further reduced, and the safety can be further improved.
< coating composition (embodiment 2) >
The polyisocyanate composition according to embodiment 2 of the present invention can be suitably used as a curing agent for a coating composition, as in embodiment 1.
The coating composition of the present embodiment contains the polyisocyanate composition of embodiment 2 described above.
< resin component >
The coating composition of the present embodiment further contains a resin component as a main agent. The resin component is not particularly limited, and the same resin component as in embodiment 1 is used.
The coating composition of the present embodiment can be used for any of a solvent-based coating, an aqueous coating, and a solventless coating, as in embodiment 1.
< other additives >
The coating composition of the present embodiment may further contain a melamine-based curing agent such as a fully alkyl type, a methylol type alkyl group, or an imino type alkyl group as required in the same manner as in embodiment 1, in addition to the polyisocyanate composition and the resin component.
In addition, both the polyisocyanate composition and the coating composition of embodiment 2 described above may contain an organic solvent.
The organic solvent is not particularly limited, and the same organic solvent as in embodiment 1 can be used.
Depending on the purpose and use of the polyisocyanate composition and the coating composition of embodiment 2, various additives used in the art such as a catalyst for accelerating curing, a pigment, a leveling agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a plasticizer, and a surfactant may be mixed and used as in embodiment 1.
< use >)
The coating composition of the present embodiment is not limited to the following, and is useful as a primer or an upper-middle layer coating material for materials such as metals (steel sheets, surface-treated steel sheets, etc.), plastics, wood, films, and inorganic materials. In addition, the coating composition is also useful as a coating material for imparting aesthetic properties, weather resistance, acid resistance, rust resistance, chipping resistance, and the like to precoated metals including rust-proof steel sheets, automobile coatings, and the like. Further, the urethane composition is useful as a urethane material for adhesives, pressure-sensitive adhesives, elastomers, foams, surface-treating agents, and the like.
< coating film (embodiment 2) >
The coating film of the present embodiment is formed from the coating composition of embodiment 2 described above. The coating film of the present embodiment is obtained by applying the coating composition of embodiment 2 described above by, for example, roll coating, curtain coating, spray coating, bell coating, electrostatic coating, or the like, and curing the coating film. Therefore, the coating film of the present embodiment always exhibits stable quality and is excellent in re-coating adhesion, durability when sprayed with salt water, and contamination resistance.
< polyisocyanate composition (embodiment 3) >
Next, the polyisocyanate composition according to embodiment 3 of the present invention will be described.
The same technical features as those of embodiment 1 and/or embodiment 2 may be omitted from the description.
The polyisocyanate composition of the present embodiment contains a polyisocyanate derived from a fatty acid diisocyanate containing HDI.
In the polyisocyanate composition of the present embodiment, it is preferable that D/(a + B + C + D) is 0.50 or more, where a is a molar amount of isocyanurate groups, B is a molar amount of uretdione groups, C is a molar amount of iminooxadiazinedione groups, and D is a molar amount of biuret groups.
The above-mentioned molar amount of the functional group can be used13Determined by C-NMR measurement. Specifically, the measurement can be performed by the method described in the examples described later.
The polyisocyanate composition of the present embodiment has the above technical features, and therefore can form a coating film having excellent adhesion to a substrate and excellent stain resistance.
In addition, the lower limit value of the HDI content in the polyisocyanate composition after storage when the polyisocyanate composition of the present embodiment is stored at 50 ℃ for 1 month is preferably 0.01 mass%, more preferably 0.02 mass%, and still more preferably 0.03 mass%.
The upper limit of the HDI content in the polyisocyanate composition after storage was 0.10 mass%.
The HDI content in the polyisocyanate composition of the present embodiment can be measured by the method described in the following examples.
< polyisocyanate >
The polyisocyanate contained in the polyisocyanate composition of the present embodiment is a reactant derived from an aliphatic diisocyanate monomer containing HDI.
(diisocyanate monomer)
As the diisocyanate monomer used for producing the polyisocyanate, HDI is used, but for example, an aliphatic diisocyanate other than HDI and/or an alicyclic diisocyanate may be used in combination with HDI.
The aliphatic diisocyanate is preferably an aliphatic diisocyanate having 4 to 30 carbon atoms, and examples thereof are the same as those of embodiment 1.
The alicyclic diisocyanate is preferably an alicyclic diisocyanate having 8 to 30 carbon atoms, and examples thereof are the same as those of embodiment 1.
The polyisocyanate contained in the polyisocyanate composition of the present embodiment has a biuret group.
The "biuret group" refers to a group derived from a functional group of a polyisocyanate containing 3 molecules of diisocyanate monomers and a biuretizing agent and represented by the following formula (III-I).
Figure BDA0002441845570000461
The polyisocyanate contained in the polyisocyanate composition of the present embodiment may contain, in addition to the biuret group, at least one polyisocyanate selected from the group consisting of an isocyanurate group, a uretdione group, and an iminooxadiazinedione group.
The polyisocyanate contained in the polyisocyanate composition of the present embodiment may further contain allophanate groups, urethane groups, urea groups, carbodiimide groups, and the like, in addition to the above functional groups.
< viscosity >
The lower limit of the viscosity at 25 ℃ of the polyisocyanate composition of the present embodiment is preferably 300 mPas, more preferably 500 mPas, further preferably 1000 mPas, particularly preferably 1500 mPas, most preferably 2000 mPas.
The upper limit of the viscosity is preferably 15000 mPas, more preferably 12000 mPas, still more preferably 10000 mPas, particularly preferably 7000 mPas, most preferably 5000 mPas.
The viscosity of the polyisocyanate composition of the present embodiment at 25 ℃ is preferably 300 to 15000mPa · s, more preferably 500 to 12000mPa · s, further preferably 1000 to 10000mPa · s, particularly preferably 1500 to 7000mPa · s, and most preferably 2000 to 5000mPa · s.
When the viscosity is not less than the lower limit, the crosslinking property of the polyisocyanate composition of the present embodiment can be further improved. On the other hand, when the viscosity is not more than the above upper limit, the solid content concentration of the coating composition using the polyisocyanate composition of the present embodiment can be further increased.
The viscosity of the polyisocyanate composition purified to have a nonvolatile content of 99.5 mass% or more can be measured by using an E-type viscometer (manufactured by Tokimec, inc.). Specifically, the measurement can be carried out by the method described in the examples described later.
< content of isocyanate group (NCO content) >)
The lower limit of the content of isocyanate groups (NCO content) in the polyisocyanate composition of the present embodiment is preferably 20 mass%, more preferably 21 mass%, still more preferably 21.5 mass%, and particularly preferably 22 mass%.
The upper limit of the NCO content is preferably 25% by mass, more preferably 24% by mass, and still more preferably 23.7% by mass.
That is, the NCO content of the polyisocyanate composition of the present embodiment is preferably 20 mass% or more and 25 mass% or less, more preferably 21 mass% or more and 24 mass% or less, further preferably 21.5 mass% or more and 23.7 mass% or less, and particularly preferably 22 mass% or more and 23.7 mass% or less.
When the NCO content is not less than the lower limit, the resulting coating film can have more favorable coating film properties such as hardness. On the other hand, when the NCO content is not more than the above upper limit, the yield of the polyisocyanate composition of the present embodiment can be further improved.
The NCO content can be determined by the same method as in embodiment 2.
< average number of isocyanate groups (average number of NCO groups) >)
The lower limit of the average number of isocyanate groups (average number of NCO groups) in the polyisocyanate composition of the present embodiment is preferably 2.3, more preferably 2.5, and still more preferably 2.7.
The upper limit of the average number of NCO groups is preferably 4.0, more preferably 3.8, still more preferably 3.5, particularly preferably 3.2.
The average number of NCO groups of the polyisocyanate composition of the present embodiment is preferably 2.3 or more and 4.0 or less, more preferably 2.5 or more and 3.8 or less, further preferably 2.7 or more and 3.5 or less, and particularly preferably 2.7 or more and 3.2 or less.
The average number of NCO groups is not less than the lower limit, whereby the crosslinking property of the polyisocyanate composition of the present embodiment can be further improved. On the other hand, when the average number of NCO groups is not more than the above upper limit, the polyisocyanate composition of the present embodiment can be made to have a lower viscosity.
The average number of isocyanate groups in the polyisocyanate composition of the present embodiment can be calculated by the same method as in embodiment 2.
< number average molecular weight >
The lower limit of the number average molecular weight of the solid component in the polyisocyanate composition of the present embodiment is preferably 400, more preferably 430, still more preferably 460, and particularly preferably 480.
The upper limit of the number average molecular weight is preferably 1000, more preferably 800, still more preferably 700, and particularly preferably 600.
The number average molecular weight of the solid component in the polyisocyanate composition of the present embodiment is preferably 400 or more and 1000 or less, more preferably 430 or more and 800 or less, further preferably 460 or more and 700 or less, and particularly preferably 480 or more and 600 or less.
When the number average molecular weight is not less than the lower limit value, the yield of the obtained polyisocyanate composition tends to be further improved. On the other hand, when the number average molecular weight is not more than the upper limit value, the gloss of the obtained coating film tends to be further improved.
The number average molecular weight can be determined by GPC as a number average molecular weight based on polystyrene.
< method for producing polyisocyanate composition (embodiment 3) >
Next, a method for producing the polyisocyanate composition according to embodiment 3 will be described. The same methods as those in embodiment 1 and/or embodiment 2 may be omitted from description.
The polyisocyanate composition of the present embodiment uses at least HDI as a raw material.
The polyisocyanate composition of the present embodiment requires a biuretization reaction that forms biuret groups derived from isocyanate groups. Further, the isocyanuric esterification reaction to form an isocyanurate group, the uretdionization reaction to form a uretdione group, and the iminooxadiazinedionization reaction to form an iminooxadiazinedione group are carried out in this order or in some cases simultaneously in the presence of an excess of a diisocyanate monomer, as required. After the reaction is completed, the unreacted diisocyanate monomer is removed, thereby obtaining the polyisocyanate composition of the present embodiment.
Alternatively, the biuret group-containing polyisocyanate may be mixed with other 3 kinds of reaction products.
Among them, the method for producing the polyisocyanate composition of the present embodiment is preferably a method in which the above-mentioned 3 reactions are performed in sequence or a method in which some of them are performed simultaneously, from the viewpoint of ease of obtaining.
Further, as the side material, an alcohol compound such as an alkyl monohydric alcohol or an alkyl dihydric alcohol may be used in combination.
Process for producing polyisocyanate having biuret group
The biuret group-containing polyisocyanate (biuret group-containing polyisocyanate) can be obtained by reacting a diisocyanate monomer and a biuretizing agent.
[ biuretizing agent ]
Examples of the biuretizing agent include water, monohydric tertiary alcohols, formic acid, hydrogen sulfide, organic primary monoamines, and organic primary diamines.
In the biuretizing reaction, the diisocyanate monomer may be 3 moles or more, preferably 5 moles or more, and more preferably 5 moles or more and 40 moles or less with respect to 1 mole of the biuretizing agent.
[ solvent ]
Solvents may be used in the biuretization reaction.
As the solvent, a solvent which can dissolve a biuretizing agent such as a diisocyanate monomer and water and form a uniform phase under reaction conditions can be used. The solvent may be added in an amount necessary to form a homogeneous phase. This can suppress the formation of by-products such as polyurea.
The solvent is preferably a solvent exhibiting appropriate solubility for a biuretizing agent such as water. This makes it possible to reduce the amount of solvent to be added, and after the reaction is completed, the solvent can be separated and easily recovered. Specifically, the solubility of the biuretizing agent such as water in the solvent is preferably 0.5% or more.
In addition, the boiling point of the solvent is preferably lower than the boiling point of the diisocyanate monomer as the raw material in view of recovery and separation of the unreacted diisocyanate and the like.
Specific examples of the solvent include ethylene glycol solvents and phosphoric acid triesters.
Preferable examples of the ethylene glycol-based solvent include ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol diacetate, diethylene glycol dimethyl ether, and the like. These ethylene glycol solvents may be used alone or in combination of 2 or more.
Preferable examples of the phosphoric acid triester include trimethyl phosphate, triethyl phosphate, tripropyl phosphate, tributyl phosphate, and the like. These phosphoric triesters can be used alone or in combination of 2 or more. Among them, the phosphoric acid triester is preferably trimethyl phosphate or triethyl phosphate.
When the ethylene glycol-based solvent and the phosphoric acid-based triester are used in combination, the mixing ratio (ethylene glycol-based solvent/phosphoric acid-based triester) may be 3/7 or more and 9/1 or less in terms of mass ratio.
The amount of the solvent used may be 20 mass% or more and 50 mass% or less based on the total mass of the diisocyanate monomer and the solvent as raw materials.
Further, an OH-acidic compound exemplified in Japanese patent application laid-open No. 8-225511 (patent document 8) may be added as necessary.
[ reaction conditions ]
The reaction temperature may be 70 ℃ or higher and 200 ℃ or lower, preferably 90 ℃ or higher and 180 ℃ or lower.
These reactions can be carried out in a batch process or in a continuous process. Among them, the continuous method is preferable from the viewpoint of productivity and the like. In particular, the continuous production method disclosed in Japanese patent publication No. 62-41496 (patent document 5) is preferable. In the continuous production method, the reaction of the diisocyanate monomer and the biuretizing agent is first carried out under stirring. The reaction product obtained is subsequently introduced into a tubular reactor in which the reaction is carried out under squeeze flow, whereby biuret group-containing polyisocyanates can be obtained.
Method for producing polyisocyanate having isocyanurate group
The polyisocyanate having an isocyanurate group (isocyanurate group-containing polyisocyanate) is obtained by reacting a diisocyanate monomer using an isocyanurating catalyst.
A preferable method for producing the isocyanurate group-containing polyisocyanate is, for example, a method in which an isocyanurating catalyst is added to HDI as a raw material, the reaction is carried out until a predetermined degree of polymerization is reached, and then unreacted HDI is removed as necessary, thereby obtaining an isocyanurate group-containing polyisocyanate.
In the case where the isocyanurate group-containing polyisocyanate is derived from a diisocyanate monomer, an isocyanurating reaction catalyst is generally used.
The isocyanuric acid esterification catalyst preferably has basicity. Specific examples of the catalyst for the isocyanuric acid esterification reaction include the following catalysts 1) to 7).
1) Tetraalkylammonium hydroxides or salts of weak organic acids.
Examples of the tetraalkylammonium include tetramethylammonium and tetraethylammonium.
Examples of the weak organic acid forming the salt include acetic acid and capric acid.
2) Hydroxides of hydroxyalkylammonium or salts of weak organic acids.
Examples of the hydroxyalkylammonium include trimethylhydroxypropylammonium, trimethylhydroxyethylammonium, triethylhydroxypropylammonium, and triethylhydroxyethylammonium.
Examples of the weak organic acid forming the salt include acetic acid and capric acid.
3) Metal salts of alkyl carboxylic acids.
Examples of the alkyl carboxylic acid include acetic acid, caproic acid, caprylic acid, and myristic acid.
Examples of the metal forming the salt include tin, zinc, lead, sodium, and potassium.
4) Metal alkoxides such as sodium and potassium.
5) And compounds containing an aminosilyl group such as hexamethyldisilazane.
6) Mannich bases.
7) Tertiary amines and epoxy compounds are used in combination.
Among them, the isocyanuric acid esterification catalyst is preferably an organic weak acid salt of the above 1), 2) or 3), more preferably the above 1), from the viewpoint of catalyst efficiency.
The amount of the isocyanuric acid esterification catalyst used varies depending on the amount of the solvent or the like, but is preferably 10ppm by mass or more and 1000ppm by mass or less, more preferably 10ppm by mass or more and 500ppm by mass or less, and still more preferably 10ppm by mass or more and 100 ppm by mass or less, with respect to the mass of HDI used as a raw material of the polyisocyanate.
The lower limit of the isocyanuric acid esterification reaction temperature is preferably 50 ℃, more preferably 54 ℃, still more preferably 57 ℃, and particularly preferably 60 ℃.
The upper limit of the isocyanuric acid esterification reaction temperature is preferably 120 ℃, more preferably 100 ℃, still more preferably 90 ℃, and particularly preferably 80 ℃.
The temperature of the isocyanuric acid esterification reaction is preferably 50 ℃ or more and 120 ℃ or less. More preferably 54 ℃ to 100 ℃, still more preferably 57 ℃ to 90 ℃, and particularly preferably 60 ℃ to 80 ℃.
When the isocyanuric acid esterification reaction temperature is not more than the above upper limit, changes in properties such as coloration of the polyisocyanate composition can be more effectively prevented.
The isocyanurated reaction is stopped at the point when it reaches the desired degree of polymerization. The isocyanuric acid esterification reaction is not limited to the following, and can be stopped by adding an acidic compound such as phosphoric acid, an acid phosphate, sulfuric acid, hydrochloric acid, or a sulfonic acid compound to the reaction solution. Thereby, the isocyanuric acid esterification catalyst is inactivated by neutralization, thermal decomposition, chemical decomposition, or the like.
After the reaction was stopped, filtration was performed as needed.
Method for producing polyisocyanate having uretdione group
The polyisocyanate having a uretdione group (uretdione group-containing polyisocyanate) is obtained by the same method as in embodiment 1.
Method for producing polyisocyanate having iminooxadiazinedione group
A polyisocyanate having an iminooxadiazinedione group (iminooxadiazinedione group-containing polyisocyanate) can also be obtained by the same method as in embodiment 1.
In the polyisocyanate composition of the present embodiment, when the molar amount of isocyanurate groups is a, the molar amount of uretdione groups is B, the molar amount of iminooxadiazinedione groups is C, and the molar amount of biuret groups is D, as described above, D/(a + B + C + D) is preferably 0.50 or more.
For example, the ratio in the polyisocyanate composition can be controlled by carrying out the following production process (1) or (2).
(1) First, before and after the biuretization reaction, each catalyst was added to carry out isocyanuric acid esterification, uretidione, and iminooxadiazinedionization reactions. Subsequently, the reaction is stopped by using a reaction terminator as necessary, and then the diisocyanate monomer is removed by purification, whereby a polyisocyanate composition can be obtained.
(2) First, biuretization is performed, and diisocyanate monomers are removed by purification to produce a 1 st polyisocyanate. Subsequently, a reaction other than biuretization is performed, and the diisocyanate monomer is removed by purification to produce a 2 nd polyisocyanate. Subsequently, the purified 1 st polyisocyanate and 2 nd polyisocyanate are mixed at a predetermined ratio, whereby a polyisocyanate composition can be obtained.
< thin film distillation step and Heat treatment step >
The reaction liquid immediately after the reaction is stopped usually contains a diisocyanate monomer such as unreacted HDI, and therefore it is preferable to remove it by a thin film evaporator, extraction, or the like.
In order to control the HDI content after storage to the upper limit value or less when the polyisocyanate composition of the present embodiment is stored at 50 ℃ for 1 month, the polyisocyanate composition of the present embodiment may be subjected to general thin film distillation 1to 5 times or more, and then subjected to thin film distillation and heat treatment, and more preferably, the thin film distillation and heat treatment may be repeated 4 to 5 times each
[ thin film distillation Process ]
The thin film distillation process may be performed by the same method as in embodiment 1 and/or embodiment 2.
[ Heat treatment Process ]
In addition, when the polyisocyanate composition of the present embodiment is stored at 50 ℃ for 1 month, it is preferable to not only reduce the HDI content before storage (hereinafter, sometimes referred to as "initial HDI content") but also maintain the HDI content after storage in a small amount. Therefore, the heat treatment step is preferably performed by the same method as in embodiment 1 and/or embodiment 2.
The initial HDI content in the polyisocyanate composition of the present embodiment is 0.10% by mass or less, more preferably 0.08% by mass or less, still more preferably 0.06% by mass or less, and still more preferably 0.05% by mass or less.
When the initial HDI content is not more than the above upper limit value, the toxicity of the polyisocyanate composition of the present embodiment can be further reduced, and the safety can be further improved.
< coating composition (embodiment 3) >
The polyisocyanate composition according to embodiment 3 of the present invention can be suitably used as a curing agent for a coating composition, as in embodiment 1 and/or embodiment 2.
The coating composition of the present embodiment contains the polyisocyanate composition of embodiment 3 described above.
< resin component >
The coating composition of the present embodiment further contains a resin component as a main agent. The resin component is not particularly limited, and the same resin components as those used in embodiment 1 and/or embodiment 2 are used.
The coating composition of the present embodiment can be used for any of a solvent-based coating, an aqueous coating, and a solventless coating, as in embodiment 1 and/or 2.
< other additives >
The coating composition of the present embodiment may further contain a melamine-based curing agent such as a fully alkyl type, a methylol type alkyl group, or an imino type alkyl group as required in the same manner as in embodiment 1 and/or embodiment 2, in addition to the polyisocyanate composition and the resin component.
The polyisocyanate composition and the coating composition according to embodiment 3 may contain an organic solvent.
The organic solvent is not particularly limited, and the same organic solvent as in embodiment 1 and/or embodiment 2 can be used.
Depending on the purpose and use of the polyisocyanate composition and the coating composition of embodiment 3, various additives used in the art, such as a curing accelerator catalyst, a pigment, a leveling agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a plasticizer, and a surfactant, may be mixed and used as in embodiment 1 and/or 2, as long as the desired effects of the present embodiment are not impaired.
< use >)
The coating composition of the present embodiment is not limited to the following, and is useful as a primer or an upper-middle layer coating material for materials such as metals (steel sheets, surface-treated steel sheets, etc.), plastics, wood, films, and inorganic materials. In addition, the coating composition is also useful as a coating material for imparting aesthetic properties, weather resistance, acid resistance, rust resistance, chipping resistance, and the like to precoated metals including rust-proof steel sheets, automobile coatings, and the like. Further, the urethane composition is useful as a urethane material for adhesives, pressure-sensitive adhesives, elastomers, foams, surface-treating agents, and the like.
< coating film (embodiment 3) >
The coating film of the present embodiment is formed from the coating composition of embodiment 3 described above. The coating film of the present embodiment is obtained by applying the coating composition of embodiment 3 described above by, for example, roll coating, curtain coating, spray coating, bell coating, electrostatic coating, or the like, and curing the coating film. Therefore, the coating film of the present embodiment always exhibits stable quality, has little odor derived from the diisocyanate monomer, and is excellent in adhesion and stain resistance.
< polyisocyanate composition (embodiment 4) >
Next, the polyisocyanate composition according to embodiment 4 of the present invention will be described.
The same technical features as those of embodiment 1,2 and/or 3 may be omitted from the description.
The polyisocyanate composition of the present embodiment contains a diisocyanate containing HDI and a polyisocyanate represented by the following general formula (IV-I) (hereinafter, sometimes referred to as "polyisocyanate (IV-I)").
(X11-Y11)n11-R11-(NCO)n12(IV-I)
In the above general formula (IV-I), R11Is a residue obtained by removing isocyanate groups from a polyisocyanate derived from at least 1 diisocyanate selected from the group consisting of aliphatic diisocyanates and alicyclic isocyanates. X11Is a residue obtained by removing an active hydrogen group from a compound having an active hydrogen group and a hydrophilic group. Y is11Is a bonding structure of an isocyanate group and the above active hydrogen group. (n11+ n12) is an integer of 2to 10 inclusive. neither n11 nor n12 is 0. n11/(n11+ n 12). times.100 is 1 or more and 50 or less.
The polyisocyanate (IV-I) contained in the polyisocyanate composition of the present embodiment is a hydrophilic polyisocyanate in which a part of the isocyanate groups is modified with a compound having an active hydrogen group and a hydrophilic group.
In the polyisocyanate composition in the present embodiment, the ratio (modification ratio) of the polyisocyanate modified with the compound having an active hydrogen group and a hydrophilic group means the ratio of the active hydrogen group of the compound having an active hydrogen group and a hydrophilic group which are bonded by reaction with the isocyanate group, based on 100 molar amounts of the isocyanate group of the polyisocyanate as the raw material. The modification ratio was calculated from n11 and n12 in the general formula (IV-I) by { n11/(n11+ n12) × 100 }.
The lower limit of the modification rate is preferably 1 mol%, more preferably 2 mol%, still more preferably 3 mol%, and particularly preferably 4 mol%.
On the other hand, the upper limit of the modification rate is preferably 50 mol%, more preferably 40 mol%, still more preferably 35 mol%, and particularly preferably 30 mol%.
The modification ratio is preferably 1 mol% or more and 50 mol% or less, more preferably 2 mol% or more and 40 mol% or less, further preferably 3 mol% or more and 35 mol% or less, and particularly preferably 4 mol% or more and 30 mol% or less.
When the modification ratio is not less than the lower limit value, the polyisocyanate composition of the present embodiment is more excellent in water dispersibility. On the other hand, when the modification ratio is not more than the upper limit, the water resistance of the resulting cured product is further excellent.
The modification ratio can be measured and calculated by the method described in the examples described later.
The diisocyanate contained in the polyisocyanate composition of the present embodiment is an unreacted raw material diisocyanate generated during production of the polyisocyanate precursor used in the polyisocyanate (IV-I).
The lower limit of the content of the diisocyanate in the polyisocyanate composition of the present embodiment is preferably 0.002 mass%, more preferably 0.005 mass%, still more preferably 0.01 mass%, and particularly preferably 0.02 mass%.
On the other hand, the upper limit of the content of the diisocyanate in the polyisocyanate composition of the present embodiment is 0.1 mass%.
Further, when the polyisocyanate composition of the present embodiment is stored at 50 ℃ for 1 month, the lower limit of the content of diisocyanate in the polyisocyanate composition after storage is preferably 0.002 mass%, more preferably 0.005 mass%, still more preferably 0.01 mass%, and particularly preferably 0.02 mass%.
On the other hand, the upper limit of the content of diisocyanate in the polyisocyanate composition after storage was 0.10 mass%.
The content of diisocyanate in the polyisocyanate composition of the present embodiment can be measured by GPC.
The polyisocyanate composition of the present embodiment can provide a cured product having excellent hardness and water resistance by achieving the above-described technical features.
The respective constituent components of the polyisocyanate composition of the present embodiment are described in detail below.
< polyisocyanate (IV-I) >
The polyisocyanate (IV-I) is a polyisocyanate represented by the following general formula (IV-I). Specifically, the polyisocyanate (IV-I) is a reactant obtained from a polyisocyanate precursor and a compound having an active hydrogen group and a hydrophilic group.
(X11-Y11)n11-R11-(NCO)n12(IV-I)
In the above general formula (IV-I), R11Is a residue obtained by removing isocyanate groups from a polyisocyanate derived from at least 1 diisocyanate selected from the group consisting of aliphatic diisocyanates and alicyclic isocyanates. X11Is a residue obtained by removing an active hydrogen group from a compound having an active hydrogen group and a hydrophilic group. Y is11Is a bonding structure of an isocyanate group and the above active hydrogen group. (n11+ n12) is an integer of 2to 10 inclusive. neither n11 nor n12 is 0. n11/(n11+ n 12). times.100 is 1 or more and 50 or less.
[ polyisocyanate precursor ]
In the above general formula (IV-I), R11Is a residue of a polyisocyanate precursor from which an isocyanate group has been removed.
The polyisocyanate precursor used for producing the polyisocyanate (IV-I) is preferably a polyisocyanate precursor derived from a diisocyanate compound containing HDI. The HDI-containing diisocyanate compound may contain an aliphatic polyisocyanate and/or an alicyclic polyisocyanate other than HDI.
The aliphatic diisocyanate other than HDI is not limited to the following, and examples thereof include 1, 4-diisocyanatobutane, 1, 5-diisocyanatopentane, ethyl (2, 6-diisocyanato) hexanoate, 1, 9-diisocyanatononane, 1, 12-diisocyanatododecane, 2, 4-or 2,4, 4-trimethyl-1, 6-diisocyanatohexane, and the like.
Examples of the alicyclic diisocyanate include, but are not limited to, 1, 3-or 1, 4-bis (isocyanatomethyl) cyclohexane (hereinafter referred to as "hydrogenated XDI"), 1, 3-or 1, 4-diisocyanatocyclohexane, 3,5, 5-trimethyl 1-isocyanato-3- (isocyanatomethyl) cyclohexane (hereinafter referred to as "IPDI"), 4' -diisocyanato-dicyclohexylmethane (hereinafter referred to as "hydrogenated MDI"), and 2, 5-or 2, 6-diisocyanatomethylnorbornane. Among them, IPDI, hydrogenated XDI, or hydrogenated MDI is preferable.
The polyisocyanate precursor used for producing the polyisocyanate (IV-I) is not limited to the following, and examples thereof include polyisocyanate compounds having groups represented by the following formulae (IV-III) to (IV-XI). That is, in the polyisocyanate (IV-I), R is11Examples thereof include groups represented by the following formulas (IV-III) to (IV-XI).
The polyisocyanate compound having a group represented by the following formula (IV-III) (hereinafter sometimes referred to as "group (IV-III)") is a polyisocyanate compound having a uretdione group (IV-III)) obtained by cyclodimerization of 2 isocyanate groups.
Figure BDA0002441845570000591
The polyisocyanate compound having a group represented by the following formula (IV-IV) (hereinafter sometimes referred to as "group (IV-IV") is a polyisocyanate compound having an isocyanurate group (IV-IV)) obtained by cyclizing trimerization of 3 isocyanate groups.
Figure BDA0002441845570000601
The polyisocyanate compound having a group represented by the following formula (IV-V) (hereinafter sometimes referred to as "group (IV-V)") is a polyisocyanate compound having an iminooxadiazinedione group (IV-V)).
Figure BDA0002441845570000602
The polyisocyanate compound having a group represented by the following formula (IV-VI) (hereinafter sometimes referred to as "group (IV-VI)") is a polyisocyanate compound having a biuret group (IV-VI)) obtained by reacting 3 isocyanate groups with 1 water molecule.
Figure BDA0002441845570000611
The polyisocyanate compound having a group represented by the following formula (IV-VII) (hereinafter sometimes referred to as "group (IV-VII)") is a polyisocyanate compound having an oxadiazinetrione group (IV-VII)) obtained by reacting 2 isocyanate groups with 1 molecule of carbon dioxide.
Figure BDA0002441845570000612
The polyisocyanate compound having a group represented by the following formula (IV-VIII) (hereinafter sometimes referred to as "group (IV-VIII)") is a polyisocyanate compound having a plurality of urethane groups (group (IV-VIII)) obtained by reacting 1 isocyanate group with 1 hydroxyl group.
-NH-CO-O- (IV-VIII)
The polyisocyanate compound having a group represented by the following formula (IV-IX) (hereinafter sometimes referred to as "group (IV-IX)") is a polyisocyanate compound having an allophanate group (IV-IX)) obtained by reacting 2 isocyanate groups with 1 hydroxyl group.
Figure BDA0002441845570000621
The polyisocyanate compound having a group represented by the following formula (IV-X) (hereinafter sometimes referred to as "group (IV-X)") is a polyisocyanate compound having a ureide (urea) group (IV-X)) obtained by reacting 1 isocyanate group and 1 carboxyl group.
Figure BDA0002441845570000622
The polyisocyanate compound having a group represented by the following formula (IV-XI) (hereinafter sometimes referred to as "group (IV-XI)") is a polyisocyanate compound having a urea (urea) group (IV-XI)) obtained by reacting 1 isocyanate group and 1 primary or secondary amine.
-NH-CO-NH- (IV-XI)
(isocyanurate group/(isocyanurate group + allophanate group))
When the polyisocyanate (IV-I) contained in the polyisocyanate composition of the present embodiment has isocyanurate groups and allophanate groups, the ratio of the molar amount of isocyanurate groups to the total molar amount of isocyanate groups and allophanate groups (isocyanurate groups/(isocyanurate groups + allophanate groups)) in the polyisocyanate composition is preferably 0.80 or more and less than 0.99.
(viscosity of polyisocyanate precursor)
The lower limit of the viscosity of the polyisocyanate precursor of the present embodiment at 25 ℃ is preferably 10 mPas, more preferably 30 mPas, and still more preferably 50 mPas.
On the other hand, the upper limit of the viscosity of the polyisocyanate precursor of the present embodiment at 25 ℃ is preferably 10000 mPas, more preferably 9000 mPas, and still more preferably 8000 mPas.
The polyisocyanate precursor of the present embodiment preferably has a viscosity at 25 ℃ of 10 to 10000 mPas, more preferably 30 to 9000 mPas, and still more preferably 50 to 8000 mPas.
The viscosity can be measured using an E-type viscometer (manufactured by Tokimec, inc.).
[ Compound having an active hydrogen group and a hydrophilic group ]
In the above general formula (IV-I), X11Is a residue obtained by removing an active hydrogen group from a compound having an active hydrogen group and a hydrophilic group. In addition, Y11Is a bonding structure of an isocyanate group and the above active hydrogen group. In the compound having an active hydrogen group and a hydrophilic group, the species of the active hydrogen group and the hydrophilic group may be the same or different. When the active hydrogen group and the hydrophilic group are the same, it is preferable to have 2 or more of these functional groups.
The compound having an active hydrogen group and a hydrophilic group used for producing the polyisocyanate (IV-I) is not particularly limited, and preferably 1 or more selected from the group consisting of anionic compounds, cationic compounds, and nonionic compounds. The anionic compound, the cationic compound, and the nonionic compound each independently preferably contain an active hydrogen group for reacting with an isocyanate group contained in the polyisocyanate composition. The active hydrogen group is not particularly limited, and examples thereof include a hydroxyl group, an amino group, a mercapto group, and a carboxyl group. The hydrophilic group is not particularly limited, and examples thereof include an anionic group, a cationic group, and a nonionic group.
In addition, as Y11Examples of the structure include a bonding structure of an isocyanate group and the above-exemplified active hydrogen group.
Specifically, the bonding structure between an isocyanate group and an active hydrogen group includes, for example, a urethane group (-NH-CO-O-) as a bonding structure obtained by reacting an isocyanate group and a hydroxyl group.
For example, the bonding structure obtained by reacting an isocyanate group with an amino group includes a urea group (-NH-CO-NH-).
For example, the bonding structure obtained by the reaction of an isocyanate group and a mercapto group includes a thiocarbamate group (-NH-CO-S-).
For example, the bonding structure obtained by the reaction of an isocyanate group and a carboxyl group includes an amide group (-NH-CO-).
(anionic Compound)
The anionic compound is not particularly limited, but is preferably 1 or more selected from the group consisting of a carboxylic acid group-containing compound, a phosphoric acid group-containing compound, and a sulfonic acid group-containing compound.
Compounds containing carboxylic acid groups
The carboxylic acid group-containing compound is not particularly limited, and examples thereof include hydroxyl group-containing carboxylic acids such as monohydroxycarboxylic acids and polyhydroxycarboxylic acids.
Examples of the monohydroxycarboxylic acid include 1-hydroxyacetic acid, 3-hydroxypropionic acid, 12-hydroxy-9-octadecanoic acid, hydroxypivalic acid, and lactic acid.
Examples of the polyhydroxycarboxylic acid include dimethylolacetic acid, 2-dimethylolbutyric acid, 2-dimethylolvaleric acid, dihydroxysuccinic acid, dimethylolpropionic acid, and the like.
Among these, as the carboxylic acid group-containing compound, hydroxypivalic acid or dimethylolpropionic acid is preferable.
A compound containing a phosphoric acid group
The phosphoric acid group-containing compound is not particularly limited, and examples thereof include an acid phosphate, an acid phosphite, an acid hypophosphite, and a specific polyether phosphonate (for example, commercially available product (Solvay Nicca, Ltd.) under the trade name of RHODAFAC (registered trademark)). Among them, as the compound containing a phosphoric acid group, an acid phosphate is preferable.
The lower limit of the content of the phosphorus atom in the polyisocyanate composition of the present embodiment is preferably 0.03 mass%, more preferably 0.05 mass%, and still more preferably 0.1 mass% with respect to the total mass of the polyisocyanate composition.
On the other hand, the upper limit of the content of the phosphorus atom in the polyisocyanate composition of the present embodiment is preferably 6.0% by mass, more preferably 3.0% by mass, and still more preferably 1.0% by mass, based on the total mass of the polyisocyanate composition.
The content of the phosphorus atom in the polyisocyanate composition of the present embodiment is preferably 0.03 mass% or more and 6.0 mass% or less, more preferably 0.05 mass% or more and 3.0 mass% or less, and further preferably 0.1 mass% or more and 1.0 mass% or less, based on the total mass of the polyisocyanate composition.
When the content of the phosphorus atom in the polyisocyanate composition of the present embodiment is not less than the lower limit, the surface tension is reduced, and more favorable water dispersibility tends to be exhibited. On the other hand, when the content of the phosphorus atom is not more than the upper limit, the isocyanate group used for crosslinking tends to increase, and the coating film properties tend to be more excellent.
The method of controlling the content of phosphorus atoms in the polyisocyanate composition of the present embodiment to the above range is not limited to the following, and examples thereof include a method of adjusting the mixing ratio of the phosphoric acid group-containing compound and the polyisocyanate precursor.
The content of the phosphorus atom in the polyisocyanate composition of the present embodiment can be measured by the method described in the examples described later.
Sulfonic acid group-containing Compound
The sulfonic acid group-containing compound is not particularly limited, and examples thereof include a hydroxyl group-containing sulfonic acid and an amino group-containing sulfonic acid.
Examples of the sulfonic acid having a hydroxyl group include 2-hydroxyethanesulfonic acid, 3-hydroxypropanesulfonic acid, 4-hydroxybutanesulfonic acid, 5-hydroxypentanesulfonic acid, 6-hydroxyhexanesulfonic acid, hydroxybenzenesulfonic acid, hydroxy (methyl) benzenesulfonic acid, 4- (2-hydroxyethyl) -1-piperazineethanesulfonic acid, 4- (2-hydroxyethyl) -1-piperazinepropanesulfonic acid, 2-hydroxy-3-morpholinopropanesulfonic acid, and specific polyether sulfonates (for example, commercially available products under the trade name Tegomer (registered trademark) (TheGoldschmidtAG, Essen, Germany)).
Examples of the sulfonic acid having an amino group include 2-aminoethanesulfonic acid, 2-methylaminoethanesulfonic acid, 2- (cyclohexylamino) -ethanesulfonic acid, 3- (cyclohexylamino) -propanesulfonic acid, 4-aminotoluene-2-sulfonic acid, 5-aminotoluene-2-sulfonic acid, 2-aminonaphthalene-4-sulfonic acid, 4-aminobenzenesulfonic acid, and 3-aminobenzenesulfonic acid.
Among them, the sulfonic acid group-containing compound is preferably 2-hydroxyethanesulfonic acid, 3-hydroxypropanesulfonic acid, hydroxybenzenesulfonic acid, hydroxy (methyl) benzenesulfonic acid, 2- (cyclohexylamino) -ethanesulfonic acid, or 3- (cyclohexylamino) -propanesulfonic acid.
The lower limit of the content of the sulfur atom in the polyisocyanate composition of the present embodiment is preferably 0.03 mass%, more preferably 0.05 mass%, and still more preferably 0.1 mass%, based on the total mass of the polyisocyanate composition.
On the other hand, the upper limit of the content of the sulfur atom in the polyisocyanate composition of the present embodiment is preferably 6.0% by mass, more preferably 3.0% by mass, and still more preferably 1.0% by mass, based on the total mass of the polyisocyanate composition.
The content of the sulfur atom in the polyisocyanate composition of the present embodiment is preferably 0.03 mass% or more and 6.0 mass% or less, more preferably 0.05 mass% or more and 3.0 mass% or less, and further preferably 0.1 mass% or more and 1.0 mass% or less, based on the total mass of the polyisocyanate composition.
When the content of the sulfur atom in the polyisocyanate composition of the present embodiment is not less than the lower limit, the surface tension is reduced, and more favorable water dispersibility tends to be exhibited. On the other hand, when the content of the sulfur atom is not more than the upper limit, the isocyanate group used for crosslinking tends to increase, and the coating film properties tend to be more excellent.
The method of controlling the content of the sulfur atom in the polyisocyanate composition of the present embodiment to the above range is not limited to the following, and examples thereof include a method of adjusting the mixing ratio of the sulfonic acid group-containing compound and the polyisocyanate precursor.
The content of the sulfur atom in the polyisocyanate composition of the present embodiment can be measured by the method described in the examples described later.
Neutralizing agent
The anionic group such as a carboxylic acid group, a phosphoric acid group, or a sulfonic acid group of the anionic compound is preferably neutralized with an inorganic base or an organic amine compound. Examples of the inorganic base include alkali metals, alkaline earth metals, other metals, and ammonia.
Examples of the alkali metal include lithium, sodium, potassium, rubidium, and cesium.
Examples of the alkaline earth metal include magnesium, calcium, strontium, and barium.
Examples of the other metal include manganese, iron, cobalt, nickel, copper, zinc, silver, cadmium, lead, and aluminum.
Examples of the organic amine compound include tertiary amines having a linear aliphatic hydrocarbon group, tertiary amines having a branched aliphatic hydrocarbon group, tertiary amines having a mixed aliphatic hydrocarbon group of a linear chain and a branched chain, tertiary amines having a cyclic aliphatic hydrocarbon group, tertiary amines having an aromatic cyclic hydrocarbon group, and cyclic amines. These organic amine compounds can be used alone in 1 or mixed with 2 or more.
Examples of the tertiary amine having a linear aliphatic hydrocarbon group include trimethylamine, triethylamine, tripropylamine, tributylamine, trioctylamine, trilaurylamine, tridecylamine, and tristearylamine.
Examples of the tertiary amines having a branched aliphatic hydrocarbon group include triisopropylamine, triisobutylamine, tri-2-ethylhexylamine, tri (branched tridecyl) amine, and the like.
Examples of the tertiary amines having a mixed aliphatic hydrocarbon group having a straight chain and a branched chain include N, N-dimethylethylamine, N-dimethylpropylamine, N-dimethylisopropylamine, N-dimethylbutylamine, N-dimethylisobutylamine, N-dimethyloctylamine, N-dimethyl-2-ethylhexylamine, N-dimethyllaurylamine, N-dimethyl (branched) tridecylamine, N-dimethylstearylamine, N-diethylbutylamine, N-diethylhexylamine, N-diethyloctylamine, N-diethyl-2-ethylhexylamine, N-diethyllaurylamine, N-diisopropylmethylamine, N-diethylhexylamine, N, N-diisopropylethylamine, N-diisopropylbutylamine, N-diisopropyl-2-ethylhexylamine, etc.
Examples of the tertiary amines having a cyclic aliphatic hydrocarbon group include N, N-dimethylcyclohexylamine, N-diethylbenzylamine, N-diethylcyclohexylamine, N-dicyclohexylmethylamine, N-dicyclohexylethylamine, and tricyclohexylamine.
Examples of the tertiary amines having an aromatic hydrocarbon group include N, N-dimethylbenzylamine, N-diethylbenzylamine, N-dibenzylmethylamine, tribenzylamine, N-dimethyl-4-methylbenzylamine, N-dimethylbenzylamine, N-diethylphenylamine, and N, N-diphenylmethylamine.
Examples of the cyclic amines include N-methylpyrrolidine, N-ethylpyrrolidine, N-propylpyrrolidine, N-butylpyrrolidine, N-methylpiperidine, N-ethylpiperidine, N-propylpiperidine, N-butylpiperidine, N-methylmorpholine, N-ethylmorpholine, N-propylmorpholine, N-butylmorpholine, N-sec-butylmorpholine, N-tert-butylmorpholine, N-isobutyl morpholine, and quinuclidine.
Among these, tertiary amines having 5 to 30 carbon atoms are preferable as the organic amine compound. Specific examples of the preferred organic amine compound include those selected from the group consisting of triethylamine, tripropylamine, tributylamine, trioctylamine, trilaurylamine, tridecylamine, triisobutylamine, tri-2-ethylhexylamine, tri (branched tridecyl) amine, N-dimethylpropylamine, N-dimethylisopropylamine, N-dimethylbutylamine, N-dimethylisobutylamine, N-dimethyloctylamine, N-dimethyl-2-ethylhexylamine, N-dimethyllaurylamine, N-dimethyl (branched) tridecylamine, N-dimethylstearylamine, N-diethylbutylamine, N-diethylhexylamine, N-diethyloctylamine, N-dimethyloctylamine, N-octylamine, N-dimethyloctylamine, N-dimethyloctylamine, N, N-diethyl-2-ethylhexylamine, N-diethyllaurylamine, N-diisopropylmethylamine, N-diisopropylethylamine, N-dimethylcyclohexylamine, N-diethylcyclohexylamine, N-dicyclohexylmethylamine, N-dicyclohexylethylamine, N-dimethylbenzylamine, N-diethylbenzylamine, N-dibenzylmethylamine, tribenzylamine, N-dimethylbenzylamine, N-diethylphenylamine, N, n-diphenylmethylamine, N-methylpiperidine, N-ethylpiperidine, N-methylmorpholine, N-ethylmorpholine, quinuclidine, pyridine and quinoline.
The polyisocyanate composition of the present embodiment is modified with a compound having an active hydrogen group and a hydrophilic group to improve the water dispersibility of the polyisocyanate precursor, thereby obtaining the polyisocyanate (IV-I). In this case, the ratio of modification by the compound having an active hydrogen group and a hydrophilic group is not too high, and thus the deterioration of the physical properties (hardness and water resistance) of the coating film tends to be suppressed. That is, since the anionic compound has a high emulsifying power, a high emulsifying effect can be obtained by modifying the polyisocyanate precursor with a small amount.
The method of reacting the polyisocyanate precursor with the anionic compound is not limited to the following, and examples thereof include a method of reacting a terminal isocyanate group of the polyisocyanate precursor with an active hydrogen group of the anionic compound.
(cationic Compound)
The cationic compound is not particularly limited, and examples thereof include hydroxyl group-containing amine compounds such as dimethylethanolamine, diethylethanolamine, diethanolamine, methyldiethanolamine, N-dimethylaminohexanol, N-dimethylaminoethoxyethanol, N-dimethylaminoethoxyethoxyethanol, N' -trimethylaminoethylethanolamine, and N-methyl-N- (dimethylaminopropyl) aminoethanol. The tertiary amino group (cationic hydrophilic group) of the amine compound bonded to the isocyanate group of the polyisocyanate precursor may be further quaternized with dimethyl sulfate, diethyl sulfate, or the like.
Among these, the cationic compound is preferably dimethylethanolamine, diethylethanolamine, N-dimethylaminohexanol, N-dimethylaminoethoxyethanol, or N, N-dimethylaminoethoxyethanol.
The tertiary amino group of the cationic compound is preferably neutralized with a compound having an anionic group. The anionic group is not particularly limited, and examples thereof include a carboxyl group, a sulfonic acid group, a phosphoric acid group, a halogen group, and a sulfuric acid group.
The compound having a carboxyl group is not particularly limited, and examples thereof include formic acid, acetic acid, propionic acid, butyric acid, and lactic acid.
The compound having a sulfo group is not particularly limited, and examples thereof include ethanesulfonic acid and the like.
The compound having a phosphoric acid group is not particularly limited, and examples thereof include phosphoric acid and acid phosphate.
The compound having a halogen group is not particularly limited, and examples thereof include hydrochloric acid.
The compound having a sulfate group is not particularly limited, and examples thereof include sulfuric acid.
Among them, as the compound having an anionic group, a compound having 1 carboxyl group is preferable, and acetic acid, propionic acid, or butyric acid is more preferable.
(nonionic Compound)
The nonionic compound is not particularly limited, and examples thereof include polyalkylene glycol alkyl ethers. The polyalkylene glycol alkyl ether is a compound represented by the following general formula (IV-II) (hereinafter may be referred to as "polyalkylene glycol alkyl ether (IV-II)").
HO-(R21-O)n21-R22(IV-II)
In the above general formula (IV-II), R21Is an alkylene group having 1to 4 carbon atoms. R22An alkyl group having 1to 8 carbon atoms. n21 is an integer of 3 to 30 inclusive.
R21
R21Is an alkylene group having 1to 4 carbon atoms. Plural R21May be the same or different. Among them, a plurality of R's are preferred from the viewpoint of ease of production21Preferably the same.
As R21Examples of the alkylene group in (1) include methylene, ethylene, trimethylene and tetramethylene.
Wherein, as R21From the viewpoint of imparting hydrophilicity, an ethylene group having 2 carbon atoms is preferable.
R22
R22An alkyl group having 1to 8 carbon atoms. R22The number of carbon atoms of (b) is preferably 1 or more and 4 or less, more preferably 1.
As R22Examples of the alkyl group in (b) include methyl, ethyl, propyl, isopropyl, butyl, isobutyl and tert-butyl.
Wherein, as R22From the viewpoint of imparting hydrophilicity, a methyl group having 1 carbon atom is preferable.
·n21
n21 is the average number of alkylene glycol repeating units. From the viewpoint of water dispersibility of the polyisocyanate composition and dispersibility in the main agent, n21 is preferably 3.0 or more and 20 or less, more preferably 3.5 or more and 16 or less, and still more preferably 4.0 or more and 12 or less.
When n21 is not less than the lower limit, the emulsifying power is increased, and therefore, the dispersibility tends to be further improved, and when n21 is not more than the upper limit, the viscosity is prevented from increasing, and therefore, the dispersion tends to be easier.
The polyalkylene glycol alkyl ethers (IV-II) may be used in a single amount of 1 kind or in combination of 2 or more kinds of polyalkylene glycol alkyl ethers differing in n 21.
The average number of alkylene glycol repeating units n21 of the polyalkylene glycol alkyl ether can be determined by NMR method.
Examples of the preferred polyalkylene glycol alkyl ether (IV-II) include polyethylene glycol (mono) methyl ether, poly (ethylene, propylene) glycol (mono) methyl ether, and polyethylene glycol (mono) ethyl ether.
Among them, the polyalkylene glycol alkyl ether (IV-II) is preferably polyethylene glycol (mono) methyl ether from the viewpoint of imparting hydrophilicity.
The number of hydroxyl groups of the polyalkylene glycol alkyl ether used as the nonionic compound is preferably 1 from the viewpoint of reducing the viscosity of the polyisocyanate composition of the present embodiment.
In the polyisocyanate composition in the present embodiment, the structure (X) derived from the compound having an active hydrogen group and a hydrophilic group11And Y11) The lower limit of the content of (b) is preferably 0.5% by mass, more preferably 2% by mass, still more preferably 3% by mass, and particularly preferably 5% by mass, based on the total mass of the polyisocyanate composition.
On the other hand, in the polyisocyanate composition in the present embodiment, the structure (X) derived from the compound having an active hydrogen group and a hydrophilic group11And Y11) The upper limit of the content of (b) is preferably 50% by mass, more preferably 40% by mass, still more preferably 35% by mass, and particularly preferably 30% by mass, based on the total mass of the polyisocyanate composition.
In the polyisocyanate composition in the present embodiment, the structure (X) derived from the compound having an active hydrogen group and a hydrophilic group11And Y11) The content of (b) is preferably 0.5 to 50% by mass, more preferably 2to 40% by mass, still more preferably 3 to 35% by mass, and particularly preferably 5 to 30% by mass.
In the present embodimentIn the isocyanate composition, by the structure (X) derived from a compound having an active hydrogen group and a hydrophilic group11And Y11) The content of (b) is not less than the lower limit, and the water dispersibility of the polyisocyanate composition is further improved. On the other hand, by the structure (X) derived from a compound having an active hydrogen group and a hydrophilic group11And Y11) When the content of (b) is not more than the above upper limit, the obtained coating film has better drying property and water resistance.
In particular in the formula (IV-I), X11Is a residue of polyalkylene glycol alkyl ether from which an active hydrogen group (hydroxyl group) has been removed, and Y11X in the polyisocyanate composition of the present embodiment is a bonding structure (urethane group) of an isocyanate group and an active hydrogen group (hydroxyl group)11And Y11The total content of (b) is preferably 0.5% by mass or more and 50% by mass or less based on the total mass of the polyisocyanate composition. By X11And Y11When the total content of (b) is within the above range, the isocyanate group used for crosslinking becomes larger, and the physical properties (appearance, hardness, surface drying property, and water resistance) of the coating film and the moisture stability tend to be more excellent.
As a result of combining X11The method of controlling the content of (b) to be in the above range is not limited to the following, and examples thereof include a method of adjusting the mixing ratio of the polyalkylene glycol alkyl ether (IV-II) and the polyisocyanate precursor.
< viscosity of polyisocyanate composition >
The lower limit of the viscosity at 25 ℃ of the polyisocyanate composition of the present embodiment is not particularly limited, but is preferably 10mPa · s, more preferably 30mPa · s, and still more preferably 50mPa · s, from the viewpoint of curability.
The upper limit of the viscosity of the polyisocyanate composition of the present embodiment at 25 ℃ is not particularly limited, but is preferably 15000mPa · s, more preferably 14000mPa · s, and still more preferably 13000mPa · s, from the viewpoint of water dispersibility.
The viscosity of the polyisocyanate composition of the present embodiment at 25 ℃ is preferably 10 to 15000mPa · s, more preferably 30 to 14000mPa · s, and still more preferably 50 to 13000mPa · s.
The viscosity can be measured by an E-type viscometer (manufactured by Tokimec, inc.).
< average NCO number of polyisocyanate composition >
The lower limit of the average NCO group number (average functional group number) per 1 molecule in the polyisocyanate composition of the present embodiment is preferably 2.0, more preferably 2.3, and further preferably 2.5.
On the other hand, the upper limit of the average NCO group number (average functional group number) per 1 molecule in the polyisocyanate composition of the present embodiment is preferably 6.0, more preferably 5.5, and still more preferably 5.0.
The average number of NCO groups (average number of functional groups) per 1 molecule in the polyisocyanate composition of the present embodiment is preferably 2.0 or more and 6.0 or less, more preferably 2.3 or more and 5.5 or less, and still more preferably 2.5 or more and 5.0 or less.
The average NCO group number of the polyisocyanate composition can be measured by the method described in the examples described later.
< method for producing polyisocyanate composition (embodiment 4) >
The method for producing the polyisocyanate composition of the present embodiment includes a method including a reaction step of reacting a polyisocyanate precursor with a compound having an active hydrogen group and a hydrophilic group. This method is not limited to the following, and examples thereof include a method of reacting a terminal isocyanate group of a polyisocyanate precursor with an active hydrogen group of a compound having an active hydrogen group and a hydrophilic group.
Specific examples of the method for producing the polyisocyanate composition of the present embodiment include the following methods 1) to 3).
1) A method of reacting a polyisocyanate precursor having a content of unreacted raw material diisocyanate of 0.01 to 0.3 mass% with a compound having an active hydrogen group and a hydrophilic group.
2) A method of removing an unreacted raw material diisocyanate by reacting a polyisocyanate precursor having an arbitrary content of the unreacted raw material diisocyanate with a compound having an active hydrogen group and a hydrophilic group and purifying the reaction product.
3) The method of combination 2) is further performed after the step of 1).
Among them, the method of producing the polyisocyanate composition of the present embodiment is preferably the method of 1) above, from the viewpoint of simplicity of the production process.
In the above reaction step, the reaction temperature and the reaction time are appropriately determined according to the progress of the reaction, but the reaction temperature is preferably 0 ℃ to 150 ℃ and the reaction time is preferably 0.5 hours to 48 hours.
In the reaction step, a known catalyst may be used as needed.
Specific examples of the catalyst include organic tin compounds, organic zinc compounds, organic titanium compounds, organic zirconium compounds, tertiary amines, and diamines. These catalysts may be used alone or in combination.
Examples of the organotin compound include tin octylate, tin 2-ethyl-1-hexanoate, tin ethylhexanoate, tin laurate, tin palmitate, dibutyltin oxide, dibutyltin dichloride, dibutyltin diacetate, dibutyltin dimaleate, dibutyltin dilaurate, dioctyltin diacetate, and dioctyltin dilaurate.
Examples of the organozinc compound include zinc chloride, zinc octylate, zinc 2-ethyl-1-hexanoate, zinc 2-ethylhexanoate, zinc stearate, zinc naphthenate, and zinc acetylacetonate.
Examples of the tertiary amine include triethylamine, tributylamine, N-diisopropylethylamine, and N, N-dimethylethanolamine.
Examples of the diamines include triethylenediamine, tetramethylethylenediamine, and 1, 4-diazabicyclo [2.2.2] octane.
In the method for producing the polyisocyanate composition of the present embodiment, a solvent may be used or not. The solvent used in the method for producing the polyisocyanate composition of the present embodiment may be a hydrophilic solvent or a hydrophobic solvent.
Examples of the hydrophobic solvent include mineral spirits, solvent naphtha, laws (lowaromatic whitestrit), haws (highalcomaticwhitestrit), toluene, xylene, cyclohexane, esters, and ketones. These hydrophobic solvents may be used alone or in combination.
Examples of the esters include ethyl acetate and butyl acetate.
Examples of the ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.
Examples of the hydrophilic solvent include alcohols, ethers, and esters of ether alcohols. These hydrophilic solvents may be used alone or in combination.
Examples of the alcohols include methanol, ethanol, propanol, isopropanol, and 2-ethylhexanol.
Examples of the ethers include diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, and dipropylene glycol dimethyl ether.
Examples of the ether alcohol esters include ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, and dipropylene glycol monomethyl ether acetate.
In the method for producing the polyisocyanate composition of the present embodiment, 1 or more selected from the group consisting of an antioxidant, a light stabilizer, a polymerization inhibitor, and a surfactant may be added in addition to the polyisocyanate precursor and the compound having an active hydrogen group and a hydrophilic group.
Examples of the antioxidant, light stabilizer and polymerization inhibitor include aliphatic, aromatic or alkyl-substituted aromatic esters of phosphoric acid or phosphorous acid, hypophosphorous acid derivatives, phosphorus compounds, phenol derivatives (particularly hindered phenol compounds), sulfur-containing compounds, tin compounds and the like. They may be contained alone or in an amount of 2 or more.
Examples of the phosphorus compound include phenylphosphonic acid, phenylphosphinic acid, diphenylphosphonic acid, polyphosphonate, dialkylpentaerythritol diphosphite, and dialkylbisphenol A diphosphite.
Examples of the sulfur-containing compound include thioether compounds, dithioate compounds, mercaptobenzimidazole compounds, diphenylthiourea compounds, and thiodipropionate esters.
Examples of the tin-based compound include tin maleate, dibutyltin monooxide, and the like.
Examples of the surfactant include known anionic surfactants, cationic surfactants, and amphoteric surfactants.
< use >)
The polyisocyanate composition of the present embodiment can be suitably used as a curing agent for a coating composition. The coating composition is not particularly limited, and may be an organic solvent-based coating composition or an aqueous coating composition in which resins as coating film forming components are dissolved or dispersed in a medium mainly composed of water. Among these, the polyisocyanate composition of the present embodiment is preferably used as a curing agent for an aqueous coating composition, from the viewpoint of reducing the amount of the organic solvent used.
< Water-based paint composition (embodiment 4) >
The coating composition according to embodiment 4 of the present invention is an aqueous coating composition containing the polyisocyanate composition according to embodiment 4 and water.
The water-based coating composition of the present embodiment can be used for, for example, architectural coatings, automotive refinish coatings, plastic coatings, adhesives, building materials, household water-based coatings, other resin agents, sealants, inks, casting materials, elastomers, foams, plastic materials, fiber treating agents, and the like.
< Main agent >
The water-based coating composition may further contain a resin as a main component. The resins are not particularly limited, and examples thereof include acrylic resins, polyester resins, polyether resins, epoxy resins, fluorine resins, polyurethane resins, polyvinylidene chloride copolymers, polyvinyl chloride copolymers, vinyl acetate copolymers, acrylonitrile butadiene copolymers, polybutadiene copolymers, styrene butadiene copolymers, and the like.
Among these, the resins as the main component are preferably acrylic resins or polyester resins.
[ acrylic resins ]
The acrylic resins are not particularly limited, and examples thereof include acrylic resins obtained by polymerizing (meth) acrylates, (meth) acrylates having active hydrogen, unsaturated carboxylic acids, unsaturated amides, and other polymerizable monomers alone or in a mixture of 2 or more.
Examples of the (meth) acrylic esters include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and lauryl (meth) acrylate.
Examples of the (meth) acrylic esters having active hydrogen include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate.
Examples of the unsaturated carboxylic acids include acrylic acid, methacrylic acid, maleic acid, and itaconic acid.
Examples of the unsaturated amides include acrylamide, N-methylolacrylamide, diacetoneacrylamide and the like.
Examples of the other polymerizable monomers include glycidyl methacrylate, styrene, vinyl toluene, vinyl acetate, acrylonitrile, dibutyl fumarate, p-styrenesulfonic acid, and allyl sulfosuccinic acid.
The polymerization method is usually emulsion polymerization, and may be suspension polymerization, dispersion polymerization, or solution polymerization. In the emulsion polymerization, the polymerization may be carried out in stages.
[ polyester resins ]
The polyester resins can be obtained by, for example, subjecting a mixture of 2 or more kinds of dibasic acids and a mixture of 2 or more kinds of polyhydric alcohols to condensation reaction.
Examples of the dibasic acid include carboxylic acids such as succinic acid, adipic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, and 1, 4-cyclohexanedicarboxylic acid.
Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, diethylene glycol, 1, 4-butanediol, neopentyl glycol, 1, 6-hexanediol, trimethylpentanediol, cyclohexanediol, trimethylolpropane, glycerol, pentaerythritol, 2-hydroxymethylpropanediol, and ethoxylated trimethylolpropane.
Specific examples of the method for producing the polyester polyol include a condensation reaction by mixing the above components and heating the mixture at about 160 to 220 ℃.
Or polycaprolactones obtained by ring-opening polymerization of lactones such as epsilon-caprolactone with a polyhydric alcohol, for example, can be used as the polyester resins.
[ polyether resins ]
The polyether resins can be obtained by any of the following methods (1) to (3), for example.
(1) A process for obtaining polyether resins by random or block addition of alkylene oxides, alone or in mixtures, to polyhydroxy compounds, alone or in mixtures, using catalysts.
Examples of the catalyst include hydroxides (lithium, sodium, potassium, etc.), strongly basic catalysts (alkoxides, alkylamines, etc.), complex metal cyanide complexes (metalloporphyrin, zinc hexacyanocobaltate complex, etc.), and the like.
Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, cyclohexene oxide, and styrene oxide.
(2) A method for obtaining polyether resins by reacting a polyamine compound with an alkylene oxide.
Examples of the polyamine compound include ethylenediamine and the like.
Examples of the alkylene oxide include those similar to those exemplified in (1).
(3) A method of polymerizing acrylamide or the like using the polyether resins obtained in (1) or (2) as a medium to obtain a so-called polymer polyol.
Examples of the polyol include the polyols (i) to (vi) shown below.
(i) Diglycerol, ditrimethylolpropane, pentaerythritol, dipentaerythritol, and the like.
(ii) Sugar alcohol compounds such as erythritol, D-threitol, L-arabitol, ribitol, xylitol, sorbitol, mannitol, galactitol, and rhamnose alcohol.
(iii) Monosaccharides such as arabinose, ribose, xylose, glucose, mannose, galactose, fructose, sorbose, rhamnose, fucose, and deoxyribose.
(iv) Disaccharides trehalose, sucrose, maltose, cellobiose, gentiobiose, lactose, melibiose, and the like.
(v) Raffinose, gentianose, melezitose and the like.
(vi) Stachyose and other tetrasaccharides.
(NCO/OH)
The molar ratio (NCO/OH) of the isocyanate group in the polyisocyanate composition of the above embodiment to the hydroxyl group in the resin may be, for example, 0.2 or more and 5.0 or less, for example, 0.4 or more and 3.0 or less, for example, 0.5 or more and 2.0 or less.
When the NCO/OH ratio is not less than the above lower limit, a stronger coating film tends to be obtained. On the other hand, when the NCO/OH value is not more than the above upper limit value, the smoothness of the coating film tends to be further improved.
[ other resins ]
The water-based coating composition of the present embodiment may contain, in addition to the polyisocyanate composition and the main agent, other resins such as a melamine-based curing agent, a urethane dispersion, and a urethane acrylic emulsion, if necessary.
These resins are preferably emulsified, dispersed or dissolved in water. For this purpose, carboxyl groups, sulfo groups, and the like contained in the resin may be neutralized.
(neutralizing agent)
Specific examples of the neutralizing agent for neutralizing a carboxyl group, a sulfo group and the like include ammonia, a water-soluble amino compound and the like. Examples of the water-soluble amine compound include primary amines, secondary amines, and tertiary amines.
Examples of the primary amine include monoethanolamine, ethylamine, propylamine, isopropylamine, butylamine, ethylenediamine, and propylenediamine.
Examples of the secondary amine include dimethylamine, diethylamine, dipropylamine, diisopropylamine, dibutylamine, 2-ethylhexylamine, methylethanolamine, morpholine, and the like.
Examples of the tertiary amine include triethylamine, triethanolamine, dimethylethanolamine, and diethylethanolamine.
These neutralizing agents may be used alone in 1 kind or in combination of 2 or more kinds.
Among them, the neutralizing agent is preferably a tertiary amine, and more preferably triethylamine or dimethylethanolamine.
< other additives >
The water-based coating composition of the present embodiment may contain, in addition to the polyisocyanate composition and the main agent, other additives such as a catalyst (crosslinking reaction catalyst) for accelerating curing, an inorganic pigment, an organic pigment, an extender pigment, a silane coupling agent, a titanium coupling agent, an organic phosphate, an organic phosphite, a thickener, a leveling agent, a thixotropic agent, an antifoaming agent, a freeze stabilizer, a matting agent, an anti-skinning agent, a dispersant, a wetting agent, a filler, a plasticizer, a lubricant, a reducing agent, an antiseptic agent, an antifungal agent, a deodorizing agent, an anti-yellowing agent, an ultraviolet absorber, an antistatic agent, a charge control agent, and an anti-settling agent, which are generally added to a coating material. Among them, it is preferable to contain a catalyst for accelerating curing (crosslinking reaction catalyst) as another additive.
The catalyst for accelerating curing (crosslinking reaction catalyst) is not limited to the following, and examples thereof include metal salts and tertiary amines.
Examples of the metal salt include dibutyl tin dilaurate, tin 2-ethylhexanoate, zinc 2-ethylhexanoate, and cobalt salt.
Examples of the tertiary amine include triethylamine, pyridine, picoline, benzyldimethylamine, N-dimethylcyclohexylamine, N-methylpiperidine, pentamethyldiethylenetriamine, N '-ethanopiperazine, and N, N' -dimethylpiperazine.
The water-based coating composition of the present embodiment may further contain a surfactant in order to improve the dispersibility in the coating material.
Examples of the surfactant include the same surfactants as those exemplified in "< < method for producing polyisocyanate composition (embodiment 4) >".
The water-based coating composition of the present embodiment may further contain an antioxidant, a light stabilizer, and a polymerization inhibitor in order to improve the storage stability of the coating material.
Examples of the antioxidant, the light stabilizer and the polymerization inhibitor include the same examples as those exemplified in "< < method for producing a polyisocyanate composition (embodiment 4) >".
< cured product (embodiment 4) >
The cured product according to embodiment 4 of the present invention is formed from the water-based coating composition according to embodiment 4.
Examples of the cured product of the present embodiment include a coated substrate. The coated substrate comprises a substrate and a coating film formed by the water-based coating composition and laminated on the substrate.
The substrate is not particularly limited as long as the water-based coating composition can be applied. Specific examples of the base material include metal, wood, glass, stone, ceramic material, concrete, hard and flexible plastic, fiber product, leather product, paper, and the like. If necessary, a layer made of a normal primer may be provided between the substrate and the layer made of the water-based coating composition.
The coated substrate is obtained by, for example, applying the above-mentioned aqueous coating composition to a substrate by roll coating, curtain coating, spray coating, bell coating, electrostatic coating, or the like, and curing the coating composition. The resulting coated substrate has a coating film formed from the aqueous coating composition, and the coating film has excellent coating film hardness and water resistance.
< blocked polyisocyanate composition (embodiment 5) >
Next, the blocked polyisocyanate composition according to embodiment 5 of the present invention will be described.
The blocked polyisocyanate composition of the present embodiment is a blocked polyisocyanate composition containing a blocked polyisocyanate and a blocked diisocyanate.
The lower limit of the content of the blocked diisocyanate in the blocked polyisocyanate composition of the present embodiment is preferably 0.01 mass%, more preferably 0.02 mass%, still more preferably 0.03 mass%, and particularly preferably 0.04 mass%.
The upper limit of the content of the blocked diisocyanate in the blocked polyisocyanate composition of the present embodiment is preferably 0.16 mass%, more preferably 0.15 mass%, and still more preferably 0.10 mass%.
The content of the blocked diisocyanate in the blocked polyisocyanate composition of the present embodiment can be measured by GPC as described in examples described later.
The blocked polyisocyanate composition of the present embodiment has the above-described technical features, and thus can provide a coating film excellent in acid resistance and methanol resistance under high-temperature conditions.
< blocked polyisocyanate >
The blocked polyisocyanate contained in the blocked polyisocyanate composition of the present embodiment is obtained by blocking the isocyanate group of the polyisocyanate contained in the polyisocyanate composition with a blocking agent.
[ polyisocyanate composition ]
The polyisocyanate contained in the polyisocyanate composition is a reactant derived from a diisocyanate monomer containing HDI, and the same technical features as those of embodiment 1,2, and/or 3 may be omitted from description.
(diisocyanate monomer)
As the diisocyanate monomer used for producing the polyisocyanate, HDI is used, but for example, an aliphatic diisocyanate other than HDI and/or an alicyclic diisocyanate may be used in combination with HDI.
As the aliphatic diisocyanate, an aliphatic diisocyanate having 4 to 30 carbon atoms is preferable as in embodiment 1.
As the alicyclic diisocyanate, alicyclic diisocyanates having 8 or more and 30 or less carbon atoms are preferable as in embodiment 1.
The polyisocyanate contained in the polyisocyanate composition preferably has an isocyanurate group.
The content of the isocyanurate 3-mer in the polyisocyanate composition is not particularly limited, and is preferably 50% by mass or more and 95% by mass or less, more preferably 55% by mass or more and 95% by mass or less, and further preferably 60% by mass or more and 95% by mass or less, as in embodiment 2.
When the content of the isocyanurate 3-mer in the polyisocyanate composition is not less than the above lower limit, the viscosity of the polyisocyanate composition can be further reduced. On the other hand, when the content of the isocyanurate 3-mer in the polyisocyanate composition is not more than the above upper limit, the yield of the polyisocyanate composition can be further improved.
The polyisocyanate contained in the polyisocyanate composition may contain, in addition to the isocyanurate group, at least one polyisocyanate selected from the group consisting of a uretdione group, an iminooxadiazine dione group and a biuret group.
The viscosity of the blocked polyisocyanate composition of the present embodiment can be further reduced by containing a uretdione group.
In the polyisocyanate composition, when the molar amount of the isocyanurate group is a, the molar amount of the uretdione group is B, the molar amount of the iminooxadiazinedione group is C, and the molar amount of the biuret group is D, a/(a + B + C + D) is not particularly limited, and is preferably 0.1 or more, more preferably 0.25 or more, further preferably 0.4 or more, and particularly preferably 0.5 or more, as in embodiment 2.
Further, the polyisocyanate contained in the polyisocyanate composition may have a urethane group, a urea group, a biuret group, a carbodiimide group, or the like, in addition to the above functional groups, as in embodiment 2.
[ viscosity ]
The lower limit of the viscosity of the polyisocyanate composition at 25 ℃ is preferably 100 mPas, more preferably 150 mPas, still more preferably 200 mPas, particularly preferably 250 mPas.
The upper limit of the viscosity is preferably 15000 mPas, more preferably 12000 mPas, still more preferably 10000 mPas, particularly preferably 7000 mPas, most preferably 5000 mPas.
The viscosity of the polyisocyanate composition at 25 ℃ is preferably 100 to 15000 mPas, more preferably 150 to 12000 mPas, further preferably 200 to 10000 mPas, particularly preferably 250 to 7000 mPas, and most preferably 250 to 5000 mPas.
When the viscosity is not less than the lower limit, the crosslinking property of the polyisocyanate composition can be further improved. On the other hand, when the viscosity is not more than the above upper limit, the solid content concentration of the coating composition using the polyisocyanate composition can be further increased.
The viscosity can be measured in the same manner as in embodiment 2.
[ content of isocyanate group (NCO content) ]
The lower limit of the content of isocyanate groups (NCO content) in the polyisocyanate composition is preferably 20% by mass, more preferably 21% by mass, still more preferably 21.5% by mass, and particularly preferably 22% by mass.
The upper limit of the NCO content is preferably 25% by mass, more preferably 24% by mass, and still more preferably 23.7% by mass.
The NCO content of the polyisocyanate composition is preferably 20 mass% or more and 25 mass% or less, more preferably 21 mass% or more and 24 mass% or less, further preferably 21.5 mass% or more and 23.7 mass% or less, and particularly preferably 22 mass% or more and 23.7 mass% or less.
When the NCO content is not less than the lower limit, the resulting coating film can have more favorable coating film properties such as hardness. On the other hand, when the NCO content is not more than the above upper limit, the yield of the polyisocyanate composition can be further improved.
The NCO content can be determined by neutralizing the isocyanate group of the polyisocyanate composition with an excess of 2N amine and then back-titrating with 1N hydrochloric acid.
The NCO content is a value based on the solid content of the polyisocyanate composition. The solid content of the polyisocyanate composition can be measured by the nonvolatile content measurement method shown in the examples described later.
[ average number of isocyanate groups (average number of NCO groups) ]
As in embodiment 2, the lower limit value of the average number of isocyanate groups (average number of NCO groups) in the polyisocyanate composition is preferably 2.3, more preferably 2.5, and still more preferably 2.7.
The upper limit of the average number of NCO groups is preferably 4.0, more preferably 3.8, still more preferably 3.5, and particularly preferably 3.2.
The average number of NCO groups of the polyisocyanate composition is preferably 2.3 or more and 4.0 or less, more preferably 2.5 or more and 3.8 or less, further preferably 2.7 or more and 3.5 or less, and particularly preferably 2.7 or more and 3.2 or less.
When the average number of NCO groups is not less than the lower limit, the crosslinking property of the polyisocyanate composition can be further improved. On the other hand, when the average number of NCO groups is not more than the above upper limit, the polyisocyanate composition can be made to have a lower viscosity.
The average number of isocyanate groups in the polyisocyanate composition can be calculated in the same manner as in embodiment 2.
[ number average molecular weight ]
As in embodiment 2, the lower limit of the number average molecular weight of the solid content in the polyisocyanate composition is preferably 400, more preferably 430, still more preferably 460, and particularly preferably 480.
The upper limit of the number average molecular weight is preferably 1000, more preferably 800, still more preferably 700, and particularly preferably 600.
The number average molecular weight of the solid component in the polyisocyanate composition is preferably 400 or more and 1000 or less, more preferably 430 or more and 800 or less, further preferably 460 or more and 700 or less, particularly preferably 480 or more and 600 or less.
When the number average molecular weight is not less than the lower limit value, the yield of the obtained polyisocyanate composition tends to be further improved. On the other hand, when the number average molecular weight is not more than the upper limit value, the gloss of the obtained coating film tends to be further improved.
The number average molecular weight can be determined by GPC in the same manner as in embodiment 2.
[ HDI content ]
The HDI content in the polyisocyanate composition is 0.10 mass% or less, preferably 0.05 mass% or less.
The HDI content in the polyisocyanate composition can be measured by the method described in the examples described later.
< blocked diisocyanate >
The blocked diisocyanate contained in the blocked polyisocyanate composition of the present embodiment is obtained by blocking the isocyanate group of an unreacted diisocyanate monomer contained in the polyisocyanate composition with a blocking agent.
Examples of the diisocyanate monomer include the diisocyanate monomers exemplified in the polyisocyanate composition.
When the content of the blocked diisocyanate contained in the blocked polyisocyanate composition of the present embodiment is within the above range, a coating film excellent in acid resistance and methanol resistance under high temperature conditions can be obtained.
< end-capping agent >
The blocked isocyanate composition of the present embodiment contains 1 or 2 or more kinds of blocking agents.
Examples of the blocking agent include (1) pyrazole compounds, (2) amine compounds, (3) active methylene compounds, (4) oxime compounds, (5) alcohol compounds, (6) alkylphenol compounds, (7) phenol compounds, (8) thiol compounds, (9) amide compounds, (10) imide compounds, (11) imidazole compounds, (12) urea compounds, (13) imine compounds, (14) bisulfite, and (15) triazole compounds. More specifically, the blocking agent includes the following examples.
(1) Pyrazole compounds: pyrazole, 3-methylpyrazole, 3, 5-dimethylpyrazole and the like.
(2) Amine-based compound: diphenylamine, aniline, carbazole, di-n-propylamine, diisopropylamine, isopropylethylamine, tert-butylbenzylamine, and the like.
(3) Active methylene-based compound: dimethyl malonate, diethyl malonate, diisopropyl malonate, di-tert-butyl malonate, methyl acetoacetate, ethyl acetoacetate, acetylacetone, and the like.
(4) Oxime-based compound: formaldehyde oxime, acetaldehyde oxime, acetone oxime, methyl ethyl ketoxime, cyclohexanone oxime, and the like.
(5) Alcohol-based compound: alcohols such as methanol, ethanol, 2-propanol, n-butanol, sec-butanol, 2-ethyl-1-hexanol, 2-methoxyethanol, 2-ethoxyethanol, and 2-butoxyethanol.
(6) Alkylphenol-based compound: monoalkylphenols and dialkylphenols having an alkyl group having 4 or more carbon atoms as a substituent. Specific examples of the alkylphenol-based compound include monoalkylphenols such as n-propylphenol, isopropylphenol, n-butylphenol, sec-butylphenol, tert-butylphenol, n-hexylphenol, 2-ethylhexylphenol, n-octylphenol, and n-nonylphenol; dialkylphenols such as di-n-propylphenol, diisopropylphenol, isopropylcresol, di-n-butylphenol, di-t-butylphenol, di-sec-butylphenol, di-n-octylphenol, di-2-ethylhexylphenol, and di-n-nonylphenol.
(7) Phenol-based compound: phenol, cresol, ethylphenol, styrenated phenol, hydroxybenzoate, and the like.
(8) Thiol-based compound: butanethiol, dodecanethiol, and the like.
(9) Amide-based compound: acetanilide, acetamide, epsilon-caprolactam, delta-valerolactam, gamma-butyrolactam, and the like.
(10) An imide compound: succinimide, maleimide, and the like.
(11) An imidazole-based compound: imidazole, 2-methylimidazole, and the like.
(12) Urea-based compound: urea, thiourea, ethylene urea, and the like.
(13) Imine-based compound: ethyleneimine, polyethyleneimine, and the like.
(14) Bisulfite salt: sodium bisulfite and the like.
(15) Triazole-based compound: 3, 5-dimethyl-1, 2, 4-triazole, and the like.
Among them, the blocked isocyanate composition of the present embodiment preferably contains at least one selected from the group consisting of an amine-based compound, an oxime-based compound, a pyrazole-based compound, and an active methylene-based compound. Among them, from the viewpoint of low-temperature curability, it is more preferable to contain at least one selected from the group consisting of amine compounds, pyrazole compounds, and active methylene compounds. Among them, from the viewpoint of ease of obtaining and ease of synthesis, the compound preferably contains a pyrazole compound.
Among them, the pyrazole-based compound is preferably 3, 5-dimethylpyrazole from the viewpoint of achieving the effects (for example, acid resistance and methanol resistance) exerted by the blocked isocyanate composition of the present embodiment and the easiness of obtaining.
Among them, the amine compound is preferably diisopropylamine or tert-butylbenzylamine.
Among them, the active methylene compound is preferably diethyl malonate or ethyl acetoacetate.
Among them, methyl ethyl ketoxime is preferable as the oxime compound.
< method for producing blocked polyisocyanate composition (embodiment 5) >
An example of the method for producing a blocked polyisocyanate composition according to embodiment 5 of the present invention will be described below, and the same steps as those in embodiment 1, embodiment 2 and/or embodiment 3 may be omitted from the description.
< method for producing polyisocyanate composition >
The blocked polyisocyanate composition of the present embodiment uses a polyisocyanate composition as a raw material. In addition, the polyisocyanate composition uses a diisocyanate monomer as a raw material. Examples of the diisocyanate monomer used for producing the polyisocyanate composition include the diisocyanate monomers exemplified for the polyisocyanate compositions.
The polyisocyanate composition must be an isocyanurated reaction that forms isocyanurate groups derived from isocyanate groups. Further, the isocyanuric esterification reaction to form an isocyanurate group, the uretdionization reaction to form a uretdione group, and the iminooxadiazinedionization reaction to form an iminooxadiazinedione group are carried out in this order or in some cases simultaneously in the presence of an excess of a diisocyanate monomer, as required. After the reaction is completed, the unreacted diisocyanate monomer is removed, thereby obtaining a polyisocyanate composition.
Further, the polyisocyanate composition can also be obtained by mixing polyisocyanates having isocyanurate groups with the other 3 kinds of reactions.
Among them, from the viewpoint of ease of obtaining, a method of producing the polyisocyanate composition is preferably a method of performing the above 3 reactions in sequence or simultaneously performing some of them.
[ Process for producing isocyanurate polyisocyanate ]
The isocyanurate-type polyisocyanate is obtained by reacting a diisocyanate monomer using an isocyanurating catalyst and an alcohol as a co-catalyst in the same manner as in embodiment 1.
[ Process for producing polyisocyanate having uretdione group ]
The polyisocyanate having a uretdione group (polyisocyanate containing a uretdione group) is obtained by using a uretdione reaction catalyst in the same manner as in embodiment 1.
[ Process for producing polyisocyanate having Iminooxadiazinedione group ]
The polyisocyanate having an iminooxadiazinedione group (iminooxadiazinedione group-containing polyisocyanate) can be obtained by using an iminooxadiazinedione reaction catalyst in the same manner as in embodiment 1.
[ Process for producing polyisocyanate having biuret group ]
The polyisocyanate having a biuret group can be obtained by reacting a diisocyanate monomer and a biuretizing agent in the same manner as in embodiment 2.
< thin film distillation step and Heat treatment step >
The reaction liquid immediately after the reaction is stopped usually contains a diisocyanate monomer such as unreacted HDI, and therefore it is preferable to remove it by a thin film evaporator, extraction, or the like.
The HDI content in the polyisocyanate composition is 0.10 mass% or less, preferably 0.05 mass% or less.
When the HDI content in the polyisocyanate composition is not more than the upper limit, the blocked diisocyanate content in the blocked polyisocyanate composition of the present embodiment can be controlled to fall within the above range, and a coating film having more excellent acid resistance and alcohol resistance can be obtained.
In order to control the HDI content in the polyisocyanate composition to the above upper limit value or less, usual thin film distillation may be performed 1 or more and 5 or less times, and preferably thin film distillation and heat treatment are performed. The number of times of distillation is preferably 1 or more and 5 or less, more preferably 3 or more and 5 or less.
In order to suppress the decomposition of the polyisocyanate into the diisocyanate monomer, it is preferable to perform the thin film distillation step after the heat treatment step, reduce the concentration of the diisocyanate monomer, perform the heat treatment step again, and then perform the thin film distillation step again.
By performing the above treatment, the content of the blocked diisocyanate in the blocked polyisocyanate composition of the present embodiment can be made within the above range, and a coating film having more excellent acid resistance and methanol resistance can be obtained.
< capping reaction >
The reaction of blocking the polyisocyanate composition with the blocking agent can be carried out regardless of the presence or absence of a solvent, to obtain a blocked polyisocyanate composition.
When a solvent is used, a solvent inactive to an isocyanate group may be used.
In the capping reaction, an organic metal salt, a tertiary amine compound, an alkali metal alkoxide, or the like can be used as a catalyst. Examples of the metal contained in the organic metal salt include tin, zinc, and lead. Examples of the alkali metal contained in the alkali metal alkoxide include sodium.
The capping reaction can be carried out at a temperature of usually-20 ℃ or higher and 150 ℃ or lower, preferably 30 ℃ or higher and 100 ℃ or lower.
When the temperature of the end-capping reaction is not lower than the lower limit, the reaction rate can be further increased.
On the other hand, when the temperature of the end-capping reaction is not higher than the above upper limit, the side reaction can be more effectively suppressed. Further, in the blocking reaction, generation of a diisocyanate monomer from a polyisocyanate as a raw material is more effectively suppressed, and the blocked diisocyanate content in the obtained blocked polyisocyanate composition can be kept low.
< coating composition (embodiment 5) >
The blocked polyisocyanate composition according to embodiment 5 of the present invention can be suitably used as a curing agent for a coating composition, as in embodiment 1,2 and/or 3.
The coating composition of the present embodiment contains the blocked polyisocyanate composition of embodiment 5 described above.
< resin component >
The coating composition of the present embodiment further contains a resin component as a main agent. The resin component is not particularly limited, and the same resin components as those used in the above-described embodiments 1,2 and/or 3 are used.
The coating composition of the present embodiment can be used for any of a solvent-based base, an aqueous base, and a solventless base, as in the above-described embodiments 1,2, and/or 3.
< other additives >
The coating composition of the present embodiment may further contain a melamine-based curing agent such as a fully alkyl type, a methylol type alkyl group, an imino type alkyl group, or the like, as required, in addition to the blocked polyisocyanate composition and the resin component, as in the above embodiments 1,2, and/or 3.
The blocked polyisocyanate composition and the coating composition according to embodiment 5 may contain an organic solvent.
The organic solvent is not particularly limited, and the same organic solvents as in embodiment 1,2 and/or 3 can be used.
The blocked polyisocyanate composition and the coating composition of embodiment 5 may be used by mixing various additives used in the art, such as a curing accelerator, a pigment, a leveling agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a plasticizer, and a surfactant, as in embodiment 1,2, and/or 3, depending on the purpose and use, within a range not to impair the desired effects of the present embodiment.
< use >)
The coating composition of the present embodiment is not limited to the following, and is useful as a primer or an upper-middle layer coating material for materials such as metals (steel sheets, surface-treated steel sheets, etc.), plastics, wood, films, and inorganic materials. In addition, the coating composition is also useful as a coating material for imparting aesthetic properties, weather resistance, acid resistance, rust resistance, chipping resistance, and the like to precoated metals including rust-proof steel sheets, automobile coatings, and the like. Further, the urethane composition is useful as a urethane material for adhesives, pressure-sensitive adhesives, elastomers, foams, surface-treating agents, and the like.
< coating film (embodiment 5) >
The coating film of the present embodiment is formed from the coating composition of embodiment 5 described above. The coating film of the present embodiment is obtained by applying the coating composition of embodiment 5 described above by, for example, roll coating, curtain coating, spray coating, bell coating, electrostatic coating, or the like, and curing the coating film. Therefore, the coating film of the present embodiment always exhibits stable quality and is excellent in acid resistance and methanol resistance under high temperature conditions.
Examples
The present invention will be further illustrated by the following examples, which are not intended to limit the scope of the present invention. The measurement method and evaluation method of the physical properties of the polyisocyanate compositions obtained in examples and comparative examples are as follows.
[ Properties 1-1] measurement of isocyanate group concentration (NCO%)
The isocyanate group concentration (NCO%) of the polyisocyanate is defined as the content (mass%) of an isocyanate group contained in the polyisocyanate, and is measured by the following method.
First, 5 to 10g of polyisocyanate was precisely weighed and dissolved in 20mL of toluene. To the resulting solution, 20mL of a 2N toluene solution of di-N-butylamine was added, and the mixture was left at room temperature for 15 minutes to effect a reaction. After the completion of the reaction, the total amount of the obtained reaction mixture was back-titrated with 1N hydrochloric acid using an APB-410 automatic titrator manufactured by Kyoto electronic Co., Ltd, and the volume of 1N hydrochloric acid (sample titration amount) required for neutralization of the unreacted di-N-butylamine in the reaction mixture was determined. On the other hand, the same operation as described above was carried out except that the polyisocyanate was not used, and the volume of 1N hydrochloric acid (blank titration amount) required for the neutralization of the unreacted di-N-butylamine was determined in the same manner. Using the obtained sample titration amount and blank titration amount, the isocyanate group concentration (% by mass) was calculated by the following formula (I-A).
Isocyanate group concentration (mass%) [ { blank titration amount (mL) -sample titration amount (mL) } × 42/{ sample mass (g) × 1000} ] × 100(I-a)
[ Properties 1-2] measurement of HDI content
The area of the peak having a retention time corresponding to the molecular weight of HDI was determined by the measurement conditions of GPC described below. The percentage of the peak area to the total area of all peaks in the chromatogram was calculated, and this value was taken as the HDI content (mass%). Note that each polyisocyanate composition was stored at 50 ℃ for 1 month. The initial HDI content before storage and the HDI content after storage were measured, respectively, and the difference (Δ HDI ═ HDI content after storage) - (initial HDI content) was calculated.
(measurement conditions)
A vector: tetrahydrofuran (hereinafter sometimes referred to as "THF")
Flow rate: 0.6 mL/min
Column chromatography: connecting the series of columns of "TSKgelSuperH 1000", "TSKgelSuperH 2000" and "TSKgelSuperH 3000" (both made by TOSOH CORPORATION)
The detector: refractometer
GPC apparatus: HLC-8120GPC (manufactured by TOSOH CORPORATION)
[ Properties 1-3] measurement of color
Hazen colour (APHA) was measured using a Lovibond automatic colorimeter PFxi-195. Note that each polyisocyanate composition was stored at 50 ℃ for 1 month. The initial color before storage and the color after storage were measured, respectively, and the difference (Δ APHA) (color after storage) - (initial color) was calculated.
[ Properties 1-4] measurement of viscosity
The measurement was carried out at 25 ℃ using a Tokimec, Inc. VISCONIC ED type, E type viscometer. Note that each polyisocyanate composition was stored at 50 ℃ for 1 month. The initial viscosity before storage and the viscosity after storage were measured, respectively, and the difference (Δ viscosity ═ viscosity after storage) - (initial viscosity) was calculated.
[ Properties 1-5] identification of isocyanurate group
CDCl was first produced for the polyisocyanate compositions obtained in examples and comparative examples3And (3) solution. The obtained solution was subjected to the following measurement conditions13C-NMR measurement confirmed the isocyanurate group. From the integrated values of the signals, the component ratios (molar ratios) of the allophanate group and the uretdione group were calculated for the isocyanurate group of "100".
(measurement conditions)
The measurement device: BurkerBiospinAvance600
Observation core:13C(150MHz)
solvent: CDCl3
Cumulative number of times: 10000 times
Chemical shift references: CDCl3(77ppm)
Characteristic peaks (chemical shift values) of the respective compositions
Isocyanurate group: strong peak around 148.5ppm
Allophanate group: strong peak around 154.0ppm
Uretdione groups: strong peak around 157.3ppm
[ evaluation 1-1] measurement and evaluation of color (determination of. DELTA. APHA)
The Δ APHA obtained in Properties 1-3 was evaluated based on the following evaluation criteria.
(evaluation criteria)
○ has a Delta APHA of 6 or more
△ Δ APHA of 5
X: has a Delta APHA of 4 or less
[ evaluation 1-2] evaluation of viscosity (determination of. DELTA. viscosity)
The Δ viscosities obtained in physical properties 1to 4 were evaluated based on the following evaluation criteria.
(evaluation criteria)
○ delta viscosity of less than 30
△ has a delta viscosity of 31 to 90 inclusive
X: delta viscosity of 91 or more
[ evaluation 1-3] evaluation based on turbidity at solvent dilution (NTU) (solvent dilutability of paint)
The polyisocyanate compositions obtained in examples and comparative examples were mixed with butyl acetate as a solvent so that the mass ratio of the polyisocyanate composition to the butyl acetate was 1: 1to prepare a diluted solution. The diluted solution thus obtained was measured at a measurement wavelength of 860nm at 25 ℃ using a turbidimeter/colorimeter (product name, "2100 AN" (manufactured by HACH Co., Ltd.). The solvent dilutability was evaluated from the measurement results based on the following evaluation criteria.
(evaluation criteria)
○ less than 0.4
△, 0.4 or more and less than 0.6
X: 0.6 or more
[ evaluation 1-4] chemical resistance test
A coating composition was prepared by compounding the following components. The obtained coating composition is then applied to a glass plate so that the dry film thickness is 60 to 80 μm. Subsequently, the mixture was left at room temperature for 20 minutes and then sintered at 120 ℃ for 20 minutes to obtain a urethane coating film.
(compounding of coating composition)
Polyisocyanate compositions obtained in examples and comparative examples
Polyol (Setalux1767)
Compounding ratio (NCO/OH ═ 1.05)
Dilution solvent: acetic acid butyl ester
Coating solids: 50% by mass
On the obtained urethane coating film, cotton wool impregnated with methyl ethyl ketone was placed every 30 minutes. Next, the absorbent cotton was removed, a glass plate was placed on the black plate, and changes in appearance (presence or absence of white turbidity, presence or absence of gloss reduction, presence or absence of stickiness generation, presence or absence of swelling) of the coating film were evaluated visually and by palpation. Evaluation criteria are shown below.
(evaluation criteria)
○ No change at all
△ slight variations
X: obviously has changes
[ evaluation 1-5] evaluation of odor after storage
In a glove box which was replaced with dry nitrogen gas, 5 sheets of filter paper (25 mm. times.50 mm) were rounded into a cylindrical shape and charged into a 50mL glass bottle. Then, 10mL of each polyisocyanate composition was injected thereinto, and the cap was closed. Subsequently, it was stored at 50 ℃ for 1 month. After storage, the odor at the time of opening the lid was evaluated based on the following evaluation criteria.
(evaluation criteria)
○ No odor from HDI was perceived
△ case where odor derived from HDI was slightly sensed
X: accompanied by irritation and perception of odor derived from HDI
[ example 1-1]
100 parts by mass of HDI was charged into a 1L four-necked glass flask equipped with a thermometer, a stirrer and a nitrogen gas-tight tube, and the atmosphere in the flask was replaced with nitrogen gas and heated to 65 ℃. Then, 0.35 part by mass of 2-ethylhexanol (2-EHOH) was added thereto, and the mixture was stirred for 10 minutes. Subsequently, a 5 mass% isobutanol (i-BuOH) solution containing tetramethylammonium decanoate (TMACA) was added over 60 minutes so that the amount of TMACA added was 0.006 parts by mass. In the reaction, temperature adjustment was performed to form 65. + -. 2 ℃. When the target NCO% was obtained, 0.012 part by mass of an 85% phosphoric acid aqueous solution was added as a reaction terminator, and the temperature was raised to 100 ℃. After reaching 100 ℃, stirring was continued for 1 hour. The reaction solution was colorless and transparent. The reaction solution was filtered through a membrane filter having a pore size of 1 μm to obtain a reaction solution from which the reaction residue was separated. The obtained reaction solution was treated under the thin film distillation conditions and the heat treatment conditions shown in table 1 below to obtain a polyisocyanate composition (PI-1). The heating treatment is performed while stirring. The physical properties of the obtained polyisocyanate composition (PI-1) were measured and evaluated in accordance with the above-mentioned methods. The results are shown in table 1 below.
Examples 1-2 to 1-3 and comparative examples 1-1 to 1-6
The reaction, the stop treatment and the filtration treatment of the reaction solution were carried out in the same manner as in example 1-1, and the conditions and the number of times of the thin film distillation and the heat treatment of the obtained reaction solution were changed to the respective conditions shown in the following Table 1, thereby obtaining polyisocyanate compositions (PI-2 to PI-9). The physical properties of each of the obtained polyisocyanate compositions (PI-2 to PI-9) were measured and evaluated in accordance with the above-mentioned methods. The results are shown in table 1 below.
[ Table 1]
Figure BDA0002441845570000971
[ Table 2]
Figure BDA0002441845570000981
As is clear from Table 1, the polyisocyanate compositions PI-1 to PI-3 (examples 1-1 to 1-3) had no odor or a small amount of odor derived from HDI after storage, and were excellent in color stability, viscosity stability and solvent dilutability. In addition, the coating films obtained from these polyisocyanate compositions also have good chemical resistance.
On the other hand, polyisocyanate compositions PI-4 to PI-9 (comparative examples 1-1 to 1-6) had an odor derived from HDI accompanied with irritation after storage, and all of color stability, viscosity stability, solvent dilutability and chemical resistance of the coating film were poor.
As described above, the polyisocyanate composition according to embodiment 1 of the present invention is low in the amount of HDI generation, low in the HDI-derived odor accompanied by irritation after storage, and excellent in the color stability, viscosity stability, solvent dilutability and chemical resistance of the coating film.
[ Property 2-1] viscosity
The viscosity was measured at 25 ℃ using an E-type viscometer (manufactured by Tokimec, Inc.). For the measurement, a standard rotor (1 ℃ 34' × R24) was used. The rotational speed is as follows.
100rpm (less than 128 mPa. multidot.s)
50rpm (128 mPas or more and less than 256 mPas)
20rpm (256 mPas or more and less than 640 mPas)
10rpm (640 mPas or more and less than 1280 mPas)
5rpm (in the case of 1280 mPas or more and less than 2560 mPas)
[ Properties 2-2] nonvolatile Components
The nonvolatile components of the polyisocyanate compositions obtained in examples and comparative examples were examined by the methods described below, and the nonvolatile components were measured as they were when the nonvolatile components were 98% by mass or more.
For the nonvolatile components, the mass of each polyisocyanate composition was first measured. Then, the mixture was heated at 105 ℃ for 3 hours, and the residual amount was measured. The nonvolatile content (mass%) was determined from the following formula (II-B) using the obtained mass before and after heating.
Nonvolatile content (% by mass) of (mass of polyisocyanate composition after heating)/(mass of polyisocyanate composition before heating) × 100(II-B)
[ Properties 2-3] isocyanate group content (NCO content)
The NCO content (% by mass) was determined by neutralizing the isocyanate group in the measurement sample with an excess of 2N amine and then back-titrating with 1N hydrochloric acid.
[ Properties 2-4] number average molecular weight and ratio of number average molecular weight component of 700 or less
The number average molecular weight of the polyisocyanate composition was determined by GPC under the following measurement conditions based on polystyrene.
(measurement conditions)
The device comprises the following steps: "HLC-8120 GPC" (trade name) manufactured by TOSOH CORPORATION
A chromatographic column: TSKgelSuperH1000 (trade name). times.1 pieces manufactured by TOSOH CORPORATION
"TSKgelSuperH 2000" (trade name). times.1 roots
"TSKgelSuperH 3000" (trade name). times.1 roots
Carrier: tetrahydrofuran (THF)
The detection method comprises the following steps: differential refractometer
Sample concentration: 5 wt/vol%
The detection method comprises the following steps: parallax refractometer
Outflow volume: 0.6 mL/min
Column temperature: 30 deg.C
Then, using the obtained number average molecular weight, the ratio (% by mass) of the component having a number average molecular weight of 700 or less was determined from the following formula (II-C).
The ratio (mass%) of the components having a number average molecular weight of 700 or less is (mass of the components having a number average molecular weight of 700 or less)/(total mass of the polyisocyanate composition) × 100(II-C)
[ Properties 2-5] initial HDI content
First, a 20mL sample bottle was placed on a digital balance, and about 1g of the polyisocyanate composition produced in example or comparative example was precisely weighed as a sample. Then, 0.03-0.04 g of nitrobenzene (internal standard solution) is added for precise weighing. Further, about 9mL of ethyl acetate was added thereto, and the mixture was thoroughly mixed by closing a cap to prepare a sample.
The sample was subjected to gas chromatography under the following conditions, and the HDI content was calculated.
(measurement conditions)
The device comprises the following steps: shimadzu GC-8A
A chromatographic column: SiliconeOV-17, Kyowa chemical Co., Ltd
Temperature of the chromatographic column oven: 120 deg.C
Injection/detector temperature: 160 deg.C
[ Properties 2-6] identification of isocyanurate group
Using Avance600 (trade name) manufactured by Bruker Biospin13The measurement of C-NMR confirmed the isocyanurate group.
Specific measurement conditions are as follows.
(measurement conditions)
13C-NMR apparatus: AVANCE600 (manufactured by Bruker Biospin Co., Ltd.)
CryoProbe (CryoProbe): CPDUL600S3C/H-D-05Z (manufactured by Bruker Biospin Co., Ltd.)
Resonance frequency: 150MHz
Concentration: 60 wt/vol%
Displacement reference: CDCl3(77ppm)
Cumulative number of times: 10000 times
Pulse program: zgpg30 (proton complete decoupling, latency 2sec)
Characteristic Peak (chemical Shift value) of Each composition
Isocyanurate group: strong peak around 148.5ppm
[ Properties 2-7] HDI content in polyisocyanate composition after storage
After storing each polyisocyanate composition at 50 ℃ for 1 month under a nitrogen atmosphere, the HDI content after storage was measured by gas chromatography measurement under the measurement conditions described in the above physical properties 2to 5.
[ evaluation 2-1] pigment dispersibility
1. Production of coating compositions
An acrylic polyol (available from Toyo Synthesis K.K.; "ARUFONUH-2041" (trade name), a resin solid content of 97% or more, and a hydroxyl value of 120 mgKOH/g resin) and each of the polyisocyanate compositions were compounded so that the molar ratio of the hydroxyl group to the isocyanate group was 1: 1.
Then, 10 parts by mass of titanium oxide (made by Sakai chemical industry Co., Ltd., "R-62N" (trade name)) was added to 100 parts by mass of the total amount of the resins of the acrylic polyol and polyisocyanate composition, and the mixture was mixed for 5 minutes by using a universal mixer to obtain each coating composition.
2. Production of coating film
Each of the obtained coating compositions was applied to an aluminum plate in a film thickness of 100 μm, and naturally dried for 1 hour to obtain a coating film.
3. Evaluation of pigment dispersibility
The state of each obtained coating film was visually observed and evaluated based on the following evaluation criteria.
(evaluation criteria)
○ case where no agglomerates of titanium oxide were found as a pigment
△ some titanium oxide agglomerates were found as pigments, but no practical problems were found
X: all agglomerates of titanium oxide as a pigment were found to be problematic in practical use
[ evaluation 2-2] adhesion to recoating
1. Production of coating compositions
An acrylic polyol (available from Toyo Synthesis K.K.; "ARUFONUH-2041" (trade name), a resin solid content of 97% or more, and a hydroxyl value of 120 mgKOH/g resin) and each of the polyisocyanate compositions were compounded so that the molar ratio of the hydroxyl group to the isocyanate group was 1: 1. Then, 10 parts by mass of titanium oxide (made by Sakai chemical industry Co., Ltd., "R-62N" (trade name)) was added to 100 parts by mass of the total amount of the acrylic polyol and the polyisocyanate composition, and the mixture was mixed for 10 minutes by using a universal mixer to obtain each coating composition.
2. Production of coating film
Each of the obtained coating compositions was applied to a mild steel plate in a film thickness of 100 μm and dried at 23 ℃ for 1 day. Then, each of the obtained coating compositions was applied again to a film thickness of 100 μm and dried at 23 ℃ for 5 days to obtain a coating film.
3. Evaluation of adhesion to recoated coating
The adhesion test of each coating film obtained was carried out in accordance with JIS K5600-5-6. Evaluation was performed based on the following evaluation criteria.
○ case where coating film was not peeled
△ in the case where half or less of the release coating film is present
X: there are cases where half or more of the coating film is peeled off
[ evaluation 2-3] durability of salt spray
1. Production of coating compositions
Each coating composition was obtained using the same method as "1" of evaluation 2-2.
2. Production of coating film
Each of the obtained coating compositions was applied to an aluminum plate in a film thickness of 100. mu.m. Then dried at 23 ℃ for 1 week to obtain a coating film.
3. Evaluation of durability of salt spray
The obtained coating film was subjected to a 100-hour durability Test under the following conditions in a cycle using a complex cycle tester (manufactured by Suga Test Instruments Co., Ltd., "CYP-90" (trade name)).
(test conditions)
(1) Salt spray 5% sodium chloride aqueous solution (30 ℃, 0.5 hour) → (2) wetting standing (30 ℃, 1.5 hour) → (3) hot air 50 ℃,2 hours → (4) warm air 30 ℃,2 hours → repetition of (1) - (4) (about 17 times)
The durability of the salt spray was visually evaluated for the coating film after the test based on the following evaluation criteria.
(evaluation criteria)
◎ No cracking or reduction in gloss was observed
○ No cracking but slight reduction in gloss was observed
△ case of partial crack
X: case where cracks were generated in the entire coating film
[ evaluation 2-4] contamination resistance
1. Production of coating compositions
Each coating composition was obtained using the same method as "1" of evaluation 2-2.
2. Production of coating film
Each coating film was obtained by the same method as in "2" of evaluation 2-3.
3. Evaluation of stain resistance
Commercially available hair dye was attached to each of the obtained coating films in a size of 3cm in diameter. Followed by holding at 50 ℃ for 100 hours. Then, the hair dye was wiped off in the order of dry wiping, water wiping, ethanol wiping, and dry wiping, and the degree of contamination was visually observed. The stain resistance was evaluated based on the following evaluation criteria.
(evaluation criteria)
◎ No residual color of the hair dye solution, almost no change was observed
○ case where a part of the hair dye remains pale brown
△ case where the brown color of the hair dye remained all lightly
X: the brown color of the hair dye remained all intensely
Comparative example 2-1 production of polyisocyanate composition PII-1
A nitrogen atmosphere was introduced into a 4-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen-blowing tube and a dropping funnel, and HDI6000g and 7.0g of isobutanol were charged and the temperature in the reactor was maintained at 80 ℃ for 2 hours with stirring. Then, 5.0g of a solution prepared by diluting trimethyl-2-methyl-2-hydroxyethylammonium hydroxide, which is an isocyanurated catalyst, with isobutanol to 5% by mass was added to conduct an isocyanurated reaction. Then, phosphoric acid was added to the reaction mixture at a point at which the NCO content of the reaction mixture became 44.6 mass%, thereby stopping the reaction. Then, the reaction solution was further kept at 150 ℃ for 2 hours. Using a thin film evaporator, purification was performed 1 time at 160 ℃ and 0.2Torr, and then heat treatment was performed at 140 ℃ for 1 hour. Then, the mixture was purified again using a thin film distillation pot at 160 ℃ under 0.1Torr to obtain a polyisocyanate composition PII-1.
The obtained polyisocyanate composition PII-1 had a nonvolatile content of 99.7% by mass, a viscosity of 480 mPas (25 ℃ C.), an NCO content of 23.1% by mass, an initial HDI content of 0.12% by mass and an HDI content after storage of 0.18% by mass. In addition, by13The presence of an isocyanurate group was confirmed by C-NMR measurement.
Evaluation was then performed based on the above method. The results are shown in table 2 below.
EXAMPLE 2-1 production of polyisocyanate composition PII-2
The polyisocyanate composition PII-1 obtained in comparative example 2-1 was further subjected to a heat treatment at 140 ℃ for 1 hour, and then purified again using a thin film distillation pot under conditions of 160 ℃ and 0.1Torr to obtain a polyisocyanate composition PII-2.
The obtained polyisocyanate composition PII-2 had a nonvolatile content of 99.8% by mass, a viscosity of 490 mPas (25 ℃ C.), an NCO content of 23.0% by mass, an initial HDI content of 0.05% by mass and an HDI content after storage of 0.08% by mass.
Evaluation was then performed based on the above method. The results are shown in table 2 below.
EXAMPLE 2-2 production of polyisocyanate composition PII-3
The polyisocyanate composition PII-2 obtained in example 2-1 was further subjected to a heat treatment at 140 ℃ for 1 hour, and then purified again using a thin film distillation pot under conditions of 160 ℃ and 0.1Torr to obtain a polyisocyanate composition PII-3.
The obtained polyisocyanate composition PII-3 had a nonvolatile content of 99.8% by mass, a viscosity of 500 mPas (25 ℃ C.), an NCO content of 23.0% by mass, an initial HDI content of 0.03% by mass and an HDI content of 0.05% by mass after storage.
Evaluation was then performed based on the above method. The results are shown in table 2 below.
[ examples 2-3] production of polyisocyanate composition PII-4
The polyisocyanate composition PII-3 obtained in example 2-2 was further subjected to a heat treatment at 140 ℃ for 1 hour, and then purified again using a thin film distillation pot under conditions of 160 ℃ and 0.1Torr to obtain a polyisocyanate composition PII-4.
The obtained polyisocyanate composition PII-4 had a nonvolatile content of 99.8% by mass, a viscosity of 500 mPas (25 ℃ C.), an NCO content of 23.0% by mass, an initial HDI content of 0.01% by mass and an HDI content after storage of 0.02% by mass.
Evaluation was then performed based on the above method. The results are shown in table 2 below.
Comparative example 2-2 production of polyisocyanate composition PII-5
A nitrogen atmosphere was formed in a 4-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen-blowing tube, and a dropping funnel, and HDI6000g was charged and held at 60 ℃. Subsequently, a solution prepared by diluting tetrabutylphosphonium 1-hydro-1, 2, 4-triazole-5-carboxylate to 10 mass% with 2-ethylhexanol was added dropwise at a rate of 6g for 1 minute until an increase in internal temperature of 1to 2 ℃ was confirmed. Next, dibutyl phosphate was added at the point when the NCO content of the reaction mixture became 41.8 mass%, thereby stopping the reaction. Then, the mixture was purified 1 time at 160 ℃ under 0.2Torr using a thin film evaporator. Subsequently, the heating treatment at 140 ℃ for 1 hour and the purification at 160 ℃ and 0.1Torr using a thin film distillation pot were repeated 2 times to obtain a polyisocyanate composition PII-5.
The obtained polyisocyanate composition PII-5 had a nonvolatile content of 99.7% by mass, a viscosity of 700 mPas (25 ℃ C.), an NCO content of 21.8% by mass, an initial HDI content of 0.09% by mass and an HDI content after storage of 0.24% by mass. In addition, by 13The presence of an isocyanurate group was confirmed by C-NMR measurement.
Evaluation was then performed based on the above method. The results are shown in table 2 below.
Comparative examples 2to 3 production of polyisocyanate composition PII-6
A nitrogen atmosphere was introduced into a 4-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen-blowing tube and a dropping funnel, and HDI6000g and isobutanol 7.0g were charged and the temperature in the reactor was maintained at 80 ℃ for 2 hours with stirring. Subsequently, 5.0g of a solution prepared by diluting 5 mass% of trimethyl-2-methyl-2-hydroxyethylammonium hydroxide as a dilute isocyanuric acid esterification catalyst with isobutanol was added to conduct an isocyanuric acid esterification reaction, and phosphoric acid was added to the reaction solution at a point when the NCO content of the reaction solution became 38.7 mass%, thereby stopping the reaction. The polyisocyanate composition PII-6 was obtained by purifying 2 times at 160 ℃ and 0.2Torr using a thin film evaporator.
The obtained polyisocyanate composition PII-6 had a nonvolatile content of 99.7% by mass, a viscosity of 2500 mPas (25 ℃ C.), an NCO content of 21.8% by mass, an initial HDI content of 0.12% by mass and an HDI content after storage of 0.19% by mass. In addition, by13The presence of an isocyanurate group was confirmed by C-NMR measurement.
Evaluation was then performed based on the above method. The results are shown in table 2 below.
Comparative examples 2to 4 production of polyisocyanate composition PII-7
To the polyisocyanate composition PII-1 obtained in comparative example 2-1, HDI was added in an amount of 0.23% by mass to obtain a polyisocyanate composition PII-7.
The obtained polyisocyanate composition PII-7 had a nonvolatile content of 99.7% by mass, a viscosity of 460 mPas (25 ℃ C.), an NCO content of 23.2% by mass, an initial HDI content of 0.35% by mass and an HDI content after storage of 0.41% by mass.
Evaluation was then performed based on the above method. The results are shown in table 2 below.
Comparative examples 2to 5 production of polyisocyanate composition PII-8
A nitrogen atmosphere was formed in a 4-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen-blowing tube, and a dropping funnel, and HDI6000g was charged and held at 60 ℃. Then, a solution prepared by diluting tetrabutylphosphonium benzotriazole salt to 30 mass% with 2-ethylhexanol was added dropwise at a rate of 3g for 1 minute until an increase in internal temperature of 1to 2 ℃ was confirmed. Dibutyl phosphate was added at the point when the NCO content of the reaction solution became 40.5 mass%, thereby stopping the reaction. After purification 2 times at 160 ℃ and 0.2Torr using a thin film evaporator, the polyisocyanate composition PII-8 was obtained.
The obtained polyisocyanate composition PII-8 had a nonvolatile content of 99.7% by mass, a viscosity of 460 mPas (25 ℃ C.), an NCO content of 22.2% by mass, an initial HDI content of 0.15% by mass and an HDI content after storage of 0.40% by mass. In addition, by13The presence of an isocyanurate group was confirmed by C-NMR measurement.
Evaluation was then performed based on the above method. The results are shown in table 2 below.
[ Table 3]
Figure BDA0002441845570001081
As is clear from Table 2, the polyisocyanate compositions PII-2 to PII-4 (examples 2-1 to 2-3) had viscosities of 500 mPas or less, and they gave coating films excellent in the adhesion to recoats, the durability to salt spray and the stain resistance.
As described above, it was confirmed that the polyisocyanate composition according to embodiment 2 of the present invention has a low viscosity and can form a coating film having excellent re-coating adhesion, salt spray durability and stain resistance.
[ Property 3-1] viscosity
The viscosity was measured at 25 ℃ by the same method as that for the above physical property 2-1 using an E-type viscometer (manufactured by Tokimec, Inc.).
[ Properties 3-2] nonvolatile Components
The nonvolatile contents of the polyisocyanate compositions obtained in examples and comparative examples were measured and calculated by the same method as described for physical properties 2-2.
[ Properties 3-3] isocyanate group content (NCO content)
The NCO content (% by mass) was determined by neutralizing the isocyanate group in the measurement sample with an excessive amount of 2N amine and then back-titrating with 1N hydrochloric acid, in the same manner as in the above physical properties 2-3.
[ Properties 3-4] number average molecular weight
The number average molecular weight of the polyisocyanate composition was determined by GPC as in the case of the above physical properties 2to 4.
[ Properties 3-5] HDI content
The initial HDI content was calculated by gas chromatography analysis after preparing a sample in the same manner as physical properties 2to 5 described above.
[ Properties 3-6] the molar amounts of biuret groups, isocyanurate groups, uretdione groups and iminooxadiazine dione groups and the molar ratio of biuret groups/(isocyanurate groups + uretdione groups + iminooxadiazine dione groups + biuret groups)
Using Avance600 (trade name) manufactured by Bruker Biospin13C-NMR measurement was carried out to determine the molar amount of isocyanurate groups (A), the molar amount of uretdione groups (B), the molar amount of iminooxadiazinedione groups (C) and the molar amount of biuret groups (D), respectively.
Specific measurement conditions are as follows.
(measurement conditions)
13C-NMR apparatus: AVANCE600 (manufactured by Bruker Biospin Co., Ltd.)
CryoProbe (CryoProbe): CPDUL600S3C/H-D-05Z (manufactured by Bruker Biospin Co., Ltd.)
Resonance frequency: 150MHz
Concentration: 60 wt/vol%
Displacement reference：CDCl3(77ppm)
Cumulative number of times: 10000 times
Pulse program: zgpg30 (proton complete decoupling, latency 2sec)
In the above measurement, the integrated value of the following signals is divided by the measured number of carbons, and each molar amount is determined from the value.
Biuret group: around 156.2 ppm: integral value ÷ 2
Isocyanurate group: around 148.6 ppm: integral value ÷ 3
Uretdione groups: about 157.5 ppm: integral value ÷ 2
Iminooxadiazinedione group: around 137.3 ppm: integral value ÷ 1
D/A + B + C + D was calculated using the obtained molar amounts.
[ Properties 3-7] HDI content in polyisocyanate composition after storage
For each polyisocyanate composition after storage at 50 ℃ for 1 month under a nitrogen atmosphere, the HDI content after storage was determined by gas chromatography measurement under the above-described HDI content determination conditions.
[ evaluation 3-1] pigment dispersibility
1. Production of coating compositions
An acrylic polyol (manufactured by NuplexResin, "Setalux 1903" (trade name), resin solid content concentration: 75%, hydroxyl group amount: 4.5% by mass in resin) and a polyisocyanate composition were blended so that the molar ratio of the hydroxyl group to the isocyanate group was 1: 1. Then, 10 parts by mass of titanium oxide (made by Sakai chemical industry Co., Ltd., "R-62N" (trade name)) was added to 100 parts by mass of the total amount of the acrylic polyol and the polyisocyanate composition, and the mixture was mixed for 5 minutes at 100 rpm using a three-in-one motor. Subsequently, the viscosity of the coating material was adjusted to 20 seconds by passing through Ford CUP (FORD CUP) No.4 with butyl acetate, and the mixture was stirred at 100 rpm for 5 minutes to obtain each coating composition.
2. Production of coating film
Each of the obtained coating compositions was applied to a glass plate to have a film thickness of 40 μm, and naturally dried for 1 hour to obtain a coating film.
3. Evaluation of pigment dispersibility
The state of each obtained coating film was visually observed and evaluated based on the following evaluation criteria.
(evaluation criteria)
○ case where no agglomerates of titanium oxide were found as a pigment
△ some titanium oxide agglomerates were found as pigments, but no practical problems were found
X: all agglomerates of titanium oxide as a pigment were found to be problematic in practical use
[ evaluation 3-2] odor
1. Production of coating compositions
An acrylic polyol (manufactured by NuplexResin, "Setalux 1903" (trade name), resin solid content concentration: 75%, hydroxyl group amount: 4.5% by mass in resin) and a polyisocyanate composition were blended so that the molar ratio of the hydroxyl group to the isocyanate group was 1: 1. Then, 10 parts by mass of titanium oxide (made by Sakai chemical industry Co., Ltd., "R-62N" (trade name)) was added to 100 parts by mass of the total amount of the acrylic polyol and the polyisocyanate composition, and the mixture was mixed for 10 minutes at 200 rpm using a three-in-one motor. Subsequently, the viscosity of the coating material was adjusted to 20 seconds by passing through Ford CUP (FORD CUP) No.4 with butyl acetate, and the mixture was stirred at 200 rpm for 5 minutes to obtain each coating composition.
2. Production of coating film
Each of the coating compositions thus obtained was applied to an aluminum plate to form a film having a thickness of 40 μm, and dried at 23 ℃ for 24 hours to obtain a coating film.
3. Evaluation of odor
From the height of 25cm from each of the obtained coating films, odor was observed and evaluated based on the following evaluation criteria.
(evaluation criteria)
○ no odor is particularly sensed
X: in the case of an offensive odor derived from a diisocyanate monomer
[ evaluation 3-3] adhesiveness
1. Production of coating compositions
Each coating composition was obtained using the same method as "1" of evaluation 3-2.
2. Production of coating film
Each of the coating compositions thus obtained was applied to a polyamide plate (model number: 6natural (PA6), manufactured by TECAMID, 5 mm. times.50 mm) so as to have a film thickness of 40 μm, and dried at 23 ℃ for 7 days to obtain a coating film.
3. Evaluation of adhesion
The adhesion test of each coating film obtained was carried out in accordance with JIS K5600-5-6. The evaluation was performed based on the following evaluation criteria from the test results.
(evaluation criteria)
○ case where coating film was not peeled
△ in the case where half or less of the release coating film is present
X: there are cases where half or more of the coating film is peeled off
[ evaluation 3-4] contamination resistance
1. Production of coating compositions
Each coating composition was obtained using the same method as "1" of evaluation 3-2.
2. Production of coating film
Each of the obtained coating compositions was applied to an aluminum plate to have a film thickness of 40 μm, and dried at 23 ℃ for 1 week to obtain a coating film.
3. Evaluation of stain resistance
Commercially available hair dye was attached to each of the obtained coating films in a size of 3cm in diameter. Followed by holding at 50 ℃ for 100 hours. Then, the hair dye was wiped off in the order of dry wiping, water wiping, ethanol wiping, and dry wiping, and the degree of contamination was visually observed. The stain resistance was evaluated based on the following evaluation criteria.
(evaluation criteria)
◎ No residual color of the hair dye solution, almost no change was observed
○ case where a part of the hair dye remains pale brown
△ case where the brown color of the hair dye remained all lightly
X: the brown color of the hair dye remained all intensely
Comparative example 3-1 production of polyisocyanate composition PIII-1
A nitrogen atmosphere was formed in a 4-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen-blowing tube, and a dropping funnel, and HDI560g, trimethyl phosphate 120g, methyl cellosolve acetate 120g, and water 7.5g (HDI/water molar ratio: 8) were charged to maintain the solution temperature at 160 ℃ for 1 hour. The obtained reaction solution was charged at 500 g/hr into a thin film evaporator having a vacuum degree of 5Torr and a temperature of 160 ℃. The obtained polyisocyanate composition containing 4 mass% of unreacted diisocyanate monomer (HDI) was subjected to heat treatment at a solution temperature of 120 ℃ for 1 hour under a nitrogen atmosphere. For this composition, purification was again performed using a thin film evaporator under conditions of 160 ℃ and 0.2 Torr. The HDI content at this point was 0.3 mass%. Further, the polyisocyanate composition PIII-1 was obtained by conducting heat treatment at 120 ℃ for 1 hour, and purifying the mixture again using a thin film evaporator under conditions of 160 ℃ and 0.1 Torr.
The obtained polyisocyanate composition PIII-1 had a nonvolatile content of 99.7% by mass, a viscosity of 1630mPa · s (25 ℃ C.), an NCO content of 23.4% by mass, an initial HDI content of 0.17% by mass, and an HDI content after storage of 0.24% by mass. Evaluation was then performed based on the above method. The results are shown in Table 3 below.
Comparative example 3-2 production of polyisocyanate composition PIII-2
The polyisocyanate composition PIII-1 obtained in comparative example 3-1 was further subjected to a heat treatment at 120 ℃ for 1 hour, and then purified again using a thin film distillation pot at 160 ℃ under 0.1Torr to obtain a polyisocyanate composition PIII-2.
The obtained polyisocyanate composition PIII-2 had a nonvolatile content of 99.8% by mass, a viscosity of 1650 mPas (25 ℃ C.), an NCO content of 23.3% by mass, an initial HDI content of 0.10% by mass, and an HDI content after storage of 0.16% by mass. Evaluation was then performed based on the above method. The results are shown in Table 3 below.
EXAMPLE 3-1 preparation of polyisocyanate composition PIII-3
The polyisocyanate composition PIII-2 obtained in comparative example 3-2 was further subjected to a heat treatment at 110 ℃ for 2 hours, and then purified again using a thin film distillation pot under conditions of 160 ℃ and 0.1Torr to obtain a polyisocyanate composition PIII-3.
The obtained polyisocyanate composition PIII-3 had a nonvolatile content of 99.8% by mass, a viscosity of 1670 mPas (25 ℃ C.), an NCO content of 23.3% by mass, an initial HDI content of 0.05% by mass and an HDI content after storage of 0.09% by mass. Evaluation was then performed based on the above method. The results are shown in Table 3 below.
EXAMPLE 3-2 production of polyisocyanate composition PIII-4
The polyisocyanate composition PIII-3 obtained in example 3-1 was further subjected to a heat treatment at 110 ℃ for 2 hours, and then purified again using a thin film distillation pot under conditions of 160 ℃ and 0.1Torr to obtain a polyisocyanate composition PIII-4.
The obtained polyisocyanate composition PIII-4 had a nonvolatile content of 99.8% by mass, a viscosity of 1680mPa · s (25 ℃ C.), an NCO content of 23.3% by mass, an initial HDI content of 0.02% by mass, and an HDI content after storage of 0.05% by mass. Evaluation was then performed based on the above method. The results are shown in Table 3 below.
Comparative examples 3 to 3 production of polyisocyanate composition PIII-6
A nitrogen atmosphere was introduced into a 4-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen-blowing tube and a dropping funnel, and HDI6000g and 7.0g of isobutanol were charged and the temperature in the reactor was maintained at 80 ℃ for 2 hours with stirring. Then, 5.0g of a solution prepared by diluting trimethyl-2-methyl-2-hydroxyethylammonium hydroxide, which is an isocyanurated catalyst, with isobutanol to 5% by mass was added to conduct an isocyanurated reaction. Then, phosphoric acid was added to the reaction mixture at a point at which the NCO content of the reaction mixture became 44.6 mass%, thereby stopping the reaction. Then, the reaction solution was further kept at 150 ℃ for 2 hours. Using a thin film evaporator, purification was performed 1 time at 160 ℃ under 0.2 Torr. Subsequently, the polyisocyanate composition PIII-5 was purified again using a thin film distillation pot at 160 ℃ under 0.1Torr after heat treatment at 140 ℃ for 1 hour.
The obtained polyisocyanate composition PIII-5 had a nonvolatile content of 99.7% by mass, a viscosity of 480 mPas (25 ℃ C.), an NCO content of 23.1% by mass and an initial HDI content of 0.12% by mass.
Next, the polyisocyanate composition PIII-1 obtained in comparative example 3-1 and the polyisocyanate composition PIII-5 were mixed by blending in a mass ratio of 75:25 to obtain a polyisocyanate composition PIII-6.
The obtained polyisocyanate composition PIII-6 had a nonvolatile content of 99.8% by mass, a viscosity of 1200 mPas (25 ℃ C.), an NCO content of 23.3% by mass, an initial HDI content of 0.15% by mass and an HDI content after storage of 0.23% by mass. Evaluation was then performed based on the above method. The results are shown in Table 3 below.
Comparative examples 3 to 4 production of polyisocyanate composition PIII-7
Polyisocyanate composition PIII-7 was obtained in the same manner as in comparative example 3-3 except that polyisocyanate compositions PIII-1 and PIII-5 were blended and mixed at a mass ratio of 40: 60.
The obtained polyisocyanate composition PIII-7 had a nonvolatile content of 99.8% by mass, a viscosity of 790 mPa.s (25 ℃ C.), an NCO content of 23.2% by mass, an initial HDI content of 0.14% by mass and an HDI content after storage of 0.22% by mass. Evaluation was then performed based on the above method. The results are shown in Table 3 below.
Comparative examples 3 to 5 production of polyisocyanate composition PIII-8
To the polyisocyanate composition PIII-1 obtained in comparative example 3-1, 0.18% by mass of an HDI monomer was added to obtain a polyisocyanate composition PIII-8.
The obtained polyisocyanate composition PIII-8 had a nonvolatile content of 99.6% by mass, a viscosity of 1560 mPas (25 ℃ C.), an NCO content of 23.5% by mass, an initial HDI content of 0.35% by mass and an HDI content after storage of 0.44% by mass. Evaluation was then performed based on the above method. The results are shown in Table 3 below.
Comparative examples 3 to 6 production of polyisocyanate composition PIII-9
A nitrogen atmosphere was formed in a 4-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen-blowing tube, and a dropping funnel, and HDI560g, trimethyl phosphate 120g, methyl cellosolve acetate 120g, and water 7.5g (HDI/water molar ratio: 8) were charged to maintain the solution temperature at 160 ℃ for 1 hour. The obtained reaction solution was charged at 500 g/hr into a thin film evaporator having a vacuum degree of 5Torr and a temperature of 160 ℃. The obtained polyisocyanate composition containing 4 mass% of unreacted diisocyanate (HDI) monomer was subjected to heat treatment at a solution temperature of 120 ℃ for 1 hour under a nitrogen atmosphere. For this composition, purification was again performed using a thin film evaporator under conditions of 160 ℃ and 0.2 Torr. The HDI content at this point was 0.3 mass%. Further, purification was carried out again using a thin film evaporator under the conditions of 160 ℃ and 0.1Torr to obtain a polyisocyanate composition PIII-9.
The obtained polyisocyanate composition PIII-9 had a nonvolatile content of 99.7% by mass, a viscosity of 1630mPa · s (25 ℃ C.), an NCO content of 23.4% by mass, an initial HDI content of 0.18% by mass, and an HDI content after storage of 0.42% by mass. Evaluation was then performed based on the above method. The results are shown in Table 3 below.
[ Table 4]
Figure BDA0002441845570001161
As is clear from Table 3, the polyisocyanate compositions PIII-3 to PIII-4 (examples 3-1 to 3-2) gave coating films having a reduced odor, good adhesion and particularly excellent stain resistance.
As described above, it was confirmed that the polyisocyanate composition according to embodiment 3 of the present invention can form a coating film having less odor and excellent adhesion to a substrate and stain resistance.
[ Property 4-1] viscosity
The viscosity was measured at 25 ℃ with an E-type viscometer (manufactured by Tokimec, Inc.) in the same manner as the above physical property 2-1.
[ Properties 4-2] modification ratio by polyalkylene glycol alkyl ether
The modification ratio of the polyisocyanate compositions obtained in examples and comparative examples, which were prepared using the polyalkylene glycol alkyl ether as a compound having an active hydrogen group and a hydrophilic group, was such that the polyisocyanate composition was modified with the polyalkylene glycol alkyl ether at a ratio of 100 equivalents of the isocyanate group of the polyisocyanate in the raw material. As a specific measurement method, the modification ratio (mol%) by the polyalkylene glycol alkyl ether was determined from the peak area ratios of the unmodified raw material isocyanate, the 1-modified raw material isocyanate, the 2-modified raw material isocyanate and the 3-modified raw material isocyanate at 220nm in Liquid Chromatography (LC). The apparatus and conditions used are as follows.
(measurement conditions)
An LC device: product of Waters corporation, UPLC (trade name)
A chromatographic column: AcquityUPLCHSST31.8 μm manufactured by Waters corporation
C18 inner diameter 2.1mm x length 50mm
Flow rate: 0.3 mL/min
Mobile phase: 10mM ammonium acetate solution in water, B acetonitrile
Gradient conditions: the initial mobile phase composition was a/B98/2, the ratio of B increased linearly after sample injection, and a/B0/100 after 10 minutes.
The detection method comprises the following steps: photodiode array detector, measuring wavelength 220nm
[ Properties 4-3] NCO content (NCO%)
The NCO content (% by mass) was determined by neutralizing the isocyanate group in the measurement sample with an excessive amount of 2N amine and then back-titrating with 1N hydrochloric acid, in the same manner as in the above physical properties 2-3.
[ Properties 4-4] content of polyalkylene glycol alkyl ether
The polyisocyanate compositions obtained in examples and comparative examples were used as samples, and the content of the polyalkylene glycol alkyl ether in the polyisocyanate composition was calculated from the NCO content (mass%), the molecular weight of the polyalkylene glycol alkyl ether calculated from the average number of the alkylene glycol repeating units n21, and the modification ratio (mol%) of the polyalkylene glycol alkyl ether by using the following formula (i).
Content (% by mass) of (NCO content)/100%/42/{ 100- (modification rate) } × (modification rate) × (number average molecular weight of polyalkylene glycol alkyl ether) × 100% (i)
[ Properties 4-5] content of phosphorus atom based on total mass of polyisocyanate composition
The polyisocyanate compositions obtained in examples and comparative examples were used as samples, and the content of phosphorus atoms derived from phosphate groups in the polyisocyanate compositions was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) using the following apparatus and conditions.
(measurement conditions)
ICP-AES device: iCAP6300Duo (trade name) manufactured by Thermo Fisher Scientific K.K
High-frequency output power: 1150W
Coolant gas: 12L/min
Plasma gas: 0.5L/min
Carrier gas: 0.5L/min
Purging gas: 0.5L/min
Plasma torch (torch): transverse axis
A detector: CID
Measuring wavelength: 180.731nm
The pretreatment method comprises the following steps: the sample was decomposed with sulfuric acid and hydrogen peroxide to prepare a sample solution.
[ Properties 4-6] content of sulfur atom based on total mass of polyisocyanate composition
The polyisocyanate compositions obtained in examples and comparative examples were used as samples, and the content of sulfur atoms derived from sulfonic acid groups in the polyisocyanate compositions was determined by Ion Chromatography (IC) using the following apparatus and conditions.
(measurement conditions)
An IC device: ICS-1500 (trade name) manufactured by Thermo Fisher Scientific K.K. Ltd
A chromatographic column: AS12A
Mobile phase: 2.7 mmoles/LNa2CO30.3 mmole/LNaHCO3
Flow rate: 1.5 mL/min
Sample injection amount: 1mL of
Suppressor (suppressor): AERS-500
A detector: conductivity detector
The pretreatment method comprises the following steps: the sample is burned in the furnace, and the combustion gas is absorbed by the absorbing liquid.
[ Properties 4-7] diisocyanate content
About 1g of the polyisocyanate composition obtained in examples and comparative examples was precisely weighed by placing a 20mL sample bottle on a digital balance in the same manner as in the above physical properties 2to 5. Then, 0.03-0.04 g of nitrobenzene (internal standard solution) is added for precise weighing. Further, about 9mL of ethyl acetate was added thereto, and the mixture was thoroughly mixed by closing a cap to prepare a sample. Then, the adjusted solution was analyzed by gas chromatography under the following conditions to obtain a peak area having a retention time corresponding to the molecular weight of the diisocyanate. The percentage of the peak area to the total area of all peaks in the chromatogram was determined, and this value was defined as the initial diisocyanate content (mass%). The polyisocyanate compositions obtained in examples and comparative examples after storage at 50 ℃ for 1 month were also analyzed and quantified by the above-described method, and the diisocyanate content (mass%) after storage was calculated.
(measurement conditions)
The device comprises the following steps: shimadzu GC-8A
A chromatographic column: SiliconeOV-17, Kyowa chemical Co., Ltd
Chromatographic column oven temperature; 120 deg.C
Injection/detector temperature; 160 deg.C
[ evaluation 4-1] coating film hardness
1. Production of Water-based coating composition
The polyisocyanate compositions obtained in examples and comparative examples were compounded with an acrylic dispersion (product name, SeTAQUA6515, Allnex, Inc.; resin component concentration: 45 mass%, hydroxyl group concentration: 3.3 mass% (based on the resin)) so that the isocyanate group/hydroxyl group molar ratio was 1.00. Subsequently, the solid content was adjusted to 45% by mass with water to form an aqueous coating composition.
2. Preparation of coating film
Then, using each of the aqueous coating compositions obtained in "1." a coating film having a thickness of 50 μm was applied onto a glass plate, and the resultant coating film was cured at 23 ℃ and 50% RH for 24 hours to obtain a coating film.
3. Evaluation of film hardness
Then, the hardness of the obtained coating film was measured by using a pendulum hardness tester (product name, BYKGarder Co., Ltd., "Pendulumhardnesstester") to evaluate the hardness of the coating film. The evaluation criteria are as follows.
(evaluation criteria)
○ pendulum collision hardness of more than 50
△ pendulum hardness of 40-50
X: pendulum impact hardness of less than 40
[ evaluation 4-2] Water resistance
1. Production of Water-based coating composition
An aqueous coating composition was produced by the same method as "evaluation 4-1".
2. Preparation of coating film
Then, using each of the aqueous coating compositions obtained in "1." above, a coating film having a thickness of 50 μm was applied to an aluminum plate and baked at 60 ℃ for 30 minutes. Subsequently, the resultant was cooled at 23 ℃ and 50% RH for 24 hours to obtain a coating film.
3. Evaluation of Water resistance
Next, an O-ring made of silicon having a diameter of 30mm was placed on the obtained coating film, and 0.5g of water was poured thereinto. Subsequently, the film was left at 23 ℃ for 24 hours, and the appearance of the film after removing the water remaining on the surface was observed to evaluate the water resistance. The evaluation criteria are as follows.
(evaluation criteria)
○ transparent and without foaming
△ slight cloudiness or slight bubbling
X: cloudiness or blisters
Synthesis example 4-1 Synthesis of HDI polyisocyanate precursor PIV-1
A nitrogen atmosphere was formed in a 4-necked flask equipped with a stirrer, a thermometer and a gas inlet tube, and 0.5g of HDI500g and isobutanol as monomers were charged and the temperature was held at 80 ℃ for 2 hours. Subsequently, 50mg of benzyltrimethylammonium hydroxide, which is an isocyanurated catalyst, was added to conduct isocyanurated reaction. Next, dibutyl phosphate was added to the reaction mixture at the point of 12% yield, thereby stopping the reaction. The reaction solution was further held at 120 ℃ for 15 minutes to obtain an HDI polyisocyanate reaction solution. The obtained reaction solution was distilled 1 time at 160 ℃ X0.4 Torr and 2 times at 160 ℃ X0.1 Torr by a thin film distillation apparatus to remove HDI, thereby obtaining an HDI polyisocyanate precursor PIV-1.
The obtained HDI polyisocyanate precursor PIV-1 had a viscosity of 2300 mPas/25 ℃, an NCO content of 22.4 mass% and an HDI content in the polyisocyanate precursor PIV-1 of 0.06 mass%.
[ Synthesis example 4-2] Synthesis of HDI polyisocyanate precursor PIV-2
An HDI reaction solution was obtained under the same conditions as in Synthesis example 4-1. The obtained reaction solution was subjected to 1 distillation by means of a thin film distillation apparatus at 160 ℃ C. times.0.1 Torr to remove HDI, thereby obtaining an HDI polyisocyanate precursor PIV-2.
The obtained HDI polyisocyanate precursor PIV-2 had a viscosity of 2250 mPas/25 ℃, an NCO content of 22.6 mass% and an HDI content of 0.60 mass% in the polyisocyanate precursor PIV-2.
EXAMPLE 4-1 preparation of polyisocyanate composition A-1
Using the same apparatus as in Synthesis example 4-1, a nitrogen atmosphere was formed in the apparatus, 30.0 parts by mass of polyethylene glycol monomethyl ether having an average number of ethylene glycol repeating units of 9.0 (product of Nippon emulsifier Co., Ltd., "MPG-130" (trade name)) were added to 170 parts by mass of HDI polyisocyanate precursor PIV, and the mixture was stirred under nitrogen at 100 ℃ for 4 hours to effect reaction. After the reaction was completed, a polyisocyanate composition A-1 was obtained. The physical properties and evaluation results of the polyisocyanate composition A-1 are shown in Table 4 below.
EXAMPLE 4-2 production of polyisocyanate composition A-2
Using the same apparatus as in Synthesis example 4-1, a nitrogen atmosphere was formed in the apparatus, and 20.0 parts by mass of HDI polyisocyanate precursor PIV-180.0 parts by mass and polyethylene glycol monomethyl ether having an average number of ethylene glycol repeating units of 11.8 and a molecular weight of 550 (product of Nichikoku Co., Ltd., "M550" (trade name)) were added. Then, the reaction was carried out while stirring under nitrogen at 100 ℃ for 4 hours while adjusting the average number of ethylene glycol repeating units to 6.0. After the reaction was completed, polyisocyanate composition A-2 was obtained. The physical properties and evaluation results of the polyisocyanate composition A-2 are shown in Table 4 below.
EXAMPLE 4-3 production of polyisocyanate composition A-3
Using the same apparatus as in Synthesis example 4-1, a nitrogen atmosphere was formed in the apparatus, and 180.0 parts by mass of HDI polyisocyanate precursor PIV and 8.0 parts by mass of polyethylene glycol monomethyl ether having an average number of ethylene glycol repeating units of 15.0 (product of Nichioil emulsifier Co., Ltd., "MPG-081" (trade name)) were added and the reaction was carried out under nitrogen at 100 ℃ for 4 hours with stirring. After the reaction was completed, polyisocyanate composition A-3 was obtained. The physical properties and evaluation results of the polyisocyanate composition A-3 are shown in Table 4 below.
EXAMPLE 4-4 production of polyisocyanate composition A-4
Using the same apparatus as in Synthesis example 4-1, a nitrogen atmosphere was formed in the apparatus, and 20g of monobutyl phosphate and 13.0g of triethylamine were mixed to neutralize a portion of the monobutyl phosphate. 33.0 parts by mass of the mixture of monobutyl phosphate and triethylamine (hereinafter sometimes referred to as "the compound having a phosphoric acid group") obtained as described above was added to 11000 parts by mass of HDI polyisocyanate precursor PIV, and the reaction was stirred at 90 ℃ for 4 hours under nitrogen. After the reaction was completed, polyisocyanate composition A-4 was obtained. The physical properties and evaluation results of the polyisocyanate composition A-4 are shown in Table 4 below. The polyisocyanate composition A-4 had a P atom concentration of 0.31% by mass as measured by ICP-AES.
EXAMPLES 4-5 preparation of polyisocyanate composition A-5
Using the same apparatus as in Synthesis example 4-1, a nitrogen atmosphere was formed in the apparatus, and 10 parts by mass of 1-propanol was added to 20 parts by mass of a 70 mass% aqueous solution of 2-hydroxyethanesulfonic acid, followed by stirring to obtain a solution. Triethylamine was further measured so that the molar ratio was 1, and a solution diluted with the same mass part of 1-propanol was added dropwise to the stirred solution. Stirring was stopped 1 hour after the start of dropping, and dehydration and desolvation were carried out by an evaporator to obtain triethylamine 2-hydroxyethanesulfonate (hereinafter, sometimes referred to as "compound having sulfonic acid group") in an amount of 99.0 mass% as a solid content. Then, 2.5g of triethylamine 2-hydroxyethanesulfonate (compound having sulfonic acid group) obtained above, 200g of acetone, and 0.05g of dibutyltin laurate were added to 11000g of polyisocyanate precursor PIV, and the mixture was stirred at 70 ℃ for 5 hours under reflux to effect a reaction. Then, the reflux was removed, 0.3 part by mass of water was added, and the mixture was stirred at 100 ℃ for 0.5 hour to continue the reaction. After the reaction was completed, polyisocyanate composition A-5 was obtained. The physical properties and evaluation results of the polyisocyanate composition A-5 are shown in Table 4 below. The polyisocyanate composition A-5 contained 0.20% by mass of S atoms as detected by ion chromatography.
Comparative example 4-1 production of polyisocyanate composition A-6
The polyisocyanate composition A-1 was produced in the same manner as in example 4-1. Next, the obtained polyisocyanate composition A-1 was subjected to 1 distillation by means of a thin film distillation apparatus at 160 ℃ C. times.0.1 Torr to remove HDI, thereby obtaining a polyisocyanate composition A-6. The physical properties and evaluation results of the polyisocyanate composition A-6 are shown in Table 4 below.
EXAMPLES 4-6 preparation of polyisocyanate composition A-7
The polyisocyanate composition A-1 was produced in the same manner as in example 4-1. Next, the obtained polyisocyanate composition A-1 was distilled 2 times at 160 ℃ C. times.0.1 Torr using a thin film distillation apparatus to remove HDI, thereby obtaining a polyisocyanate composition A-7. The physical properties and evaluation results of the polyisocyanate composition A-7 are shown in Table 4 below.
Comparative example 4-2 production of polyisocyanate composition A-8
A polyisocyanate composition A-8 was obtained in the same manner as in example 4-1 except that the polyisocyanate precursor PIV-2 obtained in Synthesis example 4-2 was used in place of the polyisocyanate precursor PIV-1 obtained in Synthesis example 4-1. The physical properties and evaluation results of the polyisocyanate composition A-8 are shown in Table 4 below.
Comparative examples 4to 3 production of polyisocyanate composition A-9
The polyisocyanate composition A-8 was produced in the same manner as in comparative example 4-1. Next, the obtained polyisocyanate composition A-8 was subjected to 1 distillation by means of a thin film distillation apparatus at 160 ℃ C. times.0.1 Torr to remove HDI, thereby obtaining a polyisocyanate composition A-9. The physical properties and evaluation results of the polyisocyanate composition A-9 are shown in Table 4 below.
[ Table 5]
Figure BDA0002441845570001251
[ Table 6]
Figure BDA0002441845570001261
As is clear from Table 4, the polyisocyanate compositions A-1 to A5 and A-7 (examples 1to 6) gave coating films having excellent coating film hardness and water resistance.
[ Property 5-1] viscosity
The viscosity was measured at 25 ℃ with an E-type viscometer (manufactured by Tokimec, Inc.) in the same manner as the above physical property 2-1.
[ Properties 5-2] nonvolatile Components
The nonvolatile components of the polyisocyanate compositions obtained in the synthesis examples were measured and calculated in the same manner as in the above physical properties 2-2.
[ Properties 5-3] isocyanate group content (NCO content)
The NCO content (% by mass) was determined by neutralizing the isocyanate group in the measurement sample with an excessive amount of 2N amine and then back-titrating with 1N hydrochloric acid, in the same manner as in the above physical properties 2-3.
[ Properties 5-4] calculation of the isocyanate group content (calculated NCO content)
The NCO content of each blocked polyisocyanate composition was calculated from the mass of the blocked polyisocyanate composition charged at the time of production and the NCO content determined in the above [ Properties 5-3] by using the following formula (V-C).
The NCO content (mass%) was calculated as 100X (NCO content)/(mass of blocked polyisocyanate composition) (V-C)
[ Properties 5-5] HDI content in polyisocyanate composition
The HDI content in the polyisocyanate composition was measured and calculated in the same manner as in the above physical properties 2to 5.
[ Properties 5-6] content of blocked diisocyanate
The content of the blocked diisocyanate in the blocked polyisocyanate composition was determined by the number average molecular weight of polystyrene obtained by GPC under the following measurement conditions.
(measurement conditions)
The device comprises the following steps: "HLC-8120 GPC" (trade name) manufactured by TOSOH CORPORATION
A chromatographic column: TSKgelSuperH1000 (trade name). times.1 pieces manufactured by TOSOH CORPORATION
"TSKgelSuperH 2000" (trade name). times.1 roots
"TSKgelSuperH 3000" (trade name). times.1 roots
Carrier: tetrahydrofuran (THF)
The detection method comprises the following steps: differential refractometer
Sample concentration: 5 wt/vol%
The detection method comprises the following steps: parallax refractometer
Outflow volume: 0.6 mL/min
Column temperature: 30 deg.C
[ evaluation 5-1] pigment dispersibility
1. Production of coating compositions
An acrylic polyol (manufactured by NuplexResin, "Setalux 1903" (trade name), resin solid content concentration: 75%, amount of hydroxyl groups: 4.5% by mass in resin) and a blocked polyisocyanate composition were mixed so that the molar ratio of the hydroxyl groups to the isocyanate groups was 1: 1. Next, 10 parts by mass of a copper phthalocyanine Blue pigment (manufactured by Dai Highuai Kagaku K.K. 'Cyanine Blue 5206' (trade name)) was added to 100 parts by mass of the total amount of the acrylic polyol and the blocked polyisocyanate composition, and the mixture was mixed for 5 minutes at 100 revolutions per minute using a three-in-one motor. Subsequently, the viscosity of the coating material was adjusted to 20 seconds by passing through a Ford cup (FORDCUP) No.4 with butyl acetate, and the mixture was stirred at 100 rpm for 5 minutes to obtain each coating material composition.
2. Production of coating film
Each of the obtained coating compositions was applied to a glass plate to have a film thickness of 40 μm, and naturally dried for 1 hour to obtain a coating film.
3. Evaluation of pigment dispersibility
The state of each obtained coating film was visually observed and evaluated based on the following evaluation criteria.
(evaluation criteria)
○ case where no lump of pigment was found
△ some of the pigment agglomerates were found, but there was no practical problem
X: all found pigment agglomerates were found to be problematic in practical use
[ evaluation 5-2] acid resistance
1. Production of coating compositions
An acrylic polyol (manufactured by NuplexResin, "Setalux 1903" (trade name), resin solid content concentration: 75%, amount of hydroxyl groups: 4.5% by mass in resin) and a blocked polyisocyanate composition were mixed so that the molar ratio of the hydroxyl groups to the isocyanate groups was 1: 1. Next, 10 parts by mass of a copper phthalocyanine Blue pigment (manufactured by Dai Highuai Kagaku K.K. 'Cyanine Blue 5206' (trade name)) was added to 100 parts by mass of the total amount of the acrylic polyol and the blocked polyisocyanate composition, and the mixture was mixed for 10 minutes at 200 revolutions per minute using a three-in-one motor. Subsequently, the viscosity of the coating material was adjusted to 20 seconds by passing through a Ford cup (FORDCUP) No.4 with butyl acetate, and the mixture was stirred at 200 rpm for 5 minutes to obtain each coating material composition.
2. Production of coating film
Each of the obtained coating compositions was applied to an aluminum plate to a film thickness of 30 μm. Then, the mixture was sintered at 130 ℃ for 30 minutes to obtain a coating film.
3. Evaluation of acid resistance
0.5mL of a 40% aqueous solution of sulfuric acid was dropped on each of the obtained coating films, and the films were kept at 60 ℃ for 0.5 hour. Subsequently, the surface of the coating film was washed with running water and dried, and then the appearance of the coating film was visually observed and evaluated based on the following evaluation criteria.
(evaluation criteria)
◎ -substantially no change was found
○ situation where a depression is found around
△ in the case where the coating film is partially deteriorated in the spot portion
X: in the case of partial or complete dissolution of the drops
[ evaluation 5-3] methanol resistance
1. Production of coating compositions
Each coating composition was obtained using the same method as "1" of evaluation 5-2.
2. Production of coating film
For each of the obtained coating compositions, each coating film was obtained by the same method as in "2" of evaluation 5-2.
3. Evaluation of gasoline alcohol resistance
On each of the obtained coating films, a cotton ball (diameter: 25mm) impregnated in a mixed test liquid of gasoline and methanol (gasoline/methanol: 90/10, mass ratio) was placed, and further, a disposable cup was placed thereon and held at 40 ℃ for 30 minutes. Next, the cotton ball was removed, and the state of the coating surface that swelled and peeled off when passing was observed, and evaluated based on the following evaluation criteria.
(evaluation criteria)
◎ completely free of abnormalities
○ case of swelling or peeling of a part
△ in case of half-swelling or peeling of the contact surface
X: the contact surface is totally expanded or peeled
Synthesis example 5-1 production of polyisocyanate composition PV-1
A nitrogen atmosphere was introduced into a 4-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen-blowing tube and a dropping funnel, and HDI600g and isobutanol 0.7g were charged and the temperature in the reactor was maintained at 80 ℃ for 2 hours with stirring. Subsequently, 0.5g of a solution prepared by diluting trimethyl-2-methyl-2-hydroxyethylammonium hydroxide, which is an isocyanurated catalyst, with isobutanol to 5% by mass was added to conduct an isocyanurated reaction. Then, phosphoric acid was added to the reaction mixture at a point at which the NCO content of the reaction mixture became 44.6 mass%, thereby stopping the reaction. Then, the reaction solution was further kept at 150 ℃ for 2 hours. Using a thin film evaporator, purification was performed 1 time at 160 ℃ and 0.2Torr, and then heat treatment was performed at 140 ℃ and 1 Hr. Then, the mixture was purified again using a thin film distillation pot at 160 ℃ under 0.1Torr to obtain a polyisocyanate composition PV-1.
The obtained polyisocyanate composition PV-1 had a nonvolatile content of 99.7% by mass, a viscosity of 480 mPas (25 ℃ C.), an NCO content of 23.1% by mass and an HDI content of 0.12% by mass. In addition, by13The presence of an isocyanurate group was confirmed by C-NMR measurement.
Synthesis example 5-2 production of polyisocyanate composition PV-2
The polyisocyanate composition PV-1 obtained in Synthesis example 5-1 was further subjected to a heat treatment at 140 ℃ for 1 hour, and then purified again using a thin film distillation pot under conditions of 160 ℃ and 0.1Torr to obtain a polyisocyanate composition PV-2.
The obtained polyisocyanate composition PV-2 had a nonvolatile content of 99.8% by mass, a viscosity of 490 mPas (25 ℃ C.), an NCO content of 23.0% by mass and an HDI content of 0.05% by mass.
Synthesis examples 5to 3 production of polyisocyanate composition PV-3
The polyisocyanate composition PV-2 obtained in Synthesis example 5-2 was further subjected to a heat treatment at 140 ℃ for 1 hour, and then purified again using a thin film distillation pot under conditions of 160 ℃ and 0.1Torr to obtain a polyisocyanate composition PV-3.
The obtained polyisocyanate composition PV-3 had a nonvolatile content of 99.8% by mass, a viscosity of 500 mPas (25 ℃ C.), an NCO content of 23.0% by mass and an HDI content of 0.03% by mass.
Synthesis examples 5to 4 production of polyisocyanate composition PV-4
The polyisocyanate composition PV-3 obtained in Synthesis example 5-3 was further subjected to heat treatment at 140 ℃ for 1 hour, and then purified again using a thin film distillation pot under conditions of 160 ℃ and 0.1Torr to obtain a polyisocyanate composition PV-4.
The obtained polyisocyanate composition PV-4 had a nonvolatile content of 99.8% by mass, a viscosity of 490 mPas (25 ℃ C.), an NCO content of 23.0% by mass and an HDI content of 0.01% by mass.
Synthesis examples 5to 5 production of polyisocyanate composition PV-5
To 100g of the polyisocyanate composition (PV-1) obtained in Synthesis example 5-1, 0.05g of HDI monomer was added and mixed for 10 minutes to obtain a polyisocyanate composition PV-5.
The obtained polyisocyanate composition PV-5 had a nonvolatile content of 99.8% by mass, a viscosity of 480 mPas (25 ℃ C.), an NCO content of 23.1% by mass and an HDI content of 0.17% by mass.
Synthesis examples 5to 6 production of polyisocyanate composition PV-6
To 100g of the polyisocyanate composition (PV-1) obtained in Synthesis example 5-1, 0.10g of HDI monomer was added and mixed for 10 minutes to obtain a polyisocyanate composition PV-6.
The obtained polyisocyanate composition PV-6 had a nonvolatile content of 99.8% by mass, a viscosity of 470 mPas (25 ℃ C.), an NCO content of 23.2% by mass and an HDI content of 0.23% by mass.
Synthesis examples 5to 7 production of polyisocyanate composition PV-7
To 100g of the polyisocyanate composition (PV-1) obtained in Synthesis example 5-1, 0.20g of HDI monomer was added and mixed for 10 minutes to obtain a polyisocyanate composition PV-7.
The obtained polyisocyanate composition PV-7 had a nonvolatile content of 99.8% by mass, a viscosity of 460 mPas (25 ℃ C.), an NCO content of 23.2% by mass and an HDI content of 0.33% by mass.
Synthesis examples 5to 8 production of polyisocyanate composition PV-8
To 100g of the polyisocyanate composition (PV-1) obtained in Synthesis example 5-1, 0.60g of HDI monomer was added and mixed for 10 minutes to obtain a polyisocyanate composition PV-8.
The obtained polyisocyanate composition PV-8 had a nonvolatile content of 99.5% by mass, a viscosity of 430 mPas (25 ℃ C.), an NCO content of 23.4% by mass and an HDI content of 0.62% by mass.
Comparative example 5-1 production of blocked isocyanate composition B-1
A nitrogen atmosphere was formed in a 4-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen-blowing tube, and the polyisocyanate composition PV-1200g and butyl acetate (131g) were charged to bring the temperature to 70 ℃. Then, 3, 5-dimethylpyrazole (106g, 100 mol%) was added in several portions to the 4-neck flask, and the mixture was held for 2 hours. Subsequently, the NCO content was confirmed to be 0.0% by mass, and a blocked isocyanate composition B-1 having a solid content of 70% by mass was obtained.
The calculated NCO content of the resulting blocked isocyanate composition B-1 was 10.6% by mass. Evaluation was then performed based on the above method. The results are shown in table 5 below.
Comparative example 5-2 production of blocked isocyanate composition B-2
A blocked polyisocyanate composition B-2 was obtained in the same manner as in comparative example 5-1 except that PV-5 was used instead of the polyisocyanate composition PV-1.
The calculated NCO content of the resulting blocked isocyanate composition B-2 was 10.6% by mass. Evaluation was then performed based on the above method. The results are shown in Table 5.
EXAMPLE 5-1 preparation of blocked isocyanate composition B-3
A blocked polyisocyanate composition B-3 was obtained in the same manner as in comparative example 5-1 except that PV-2 was used instead of the polyisocyanate composition PV-1.
The calculated NCO content of the resulting blocked isocyanate composition B-3 was 10.5% by mass. Evaluation was then performed based on the above method. The results are shown in table 5 below.
EXAMPLE 5-2 production of blocked isocyanate composition B-4
A blocked polyisocyanate composition B-4 was obtained in the same manner as in comparative example 5-1 except that PV-3 was used instead of the polyisocyanate composition PV-1.
The calculated NCO content of the resulting blocked isocyanate composition B-4 was 10.5% by mass. Evaluation was then performed based on the above method. The results are shown in table 5 below.
EXAMPLE 5-3 production of blocked isocyanate composition B-5
A blocked polyisocyanate composition B-5 was obtained in the same manner as in comparative example 5-1 except that PV-4 was used instead of the polyisocyanate composition PV-1.
The calculated NCO content of the resulting blocked isocyanate composition B-5 was 10.5% by mass. Evaluation was then performed based on the above method. The results are shown in table 5 below.
Comparative examples 5to 3 production of blocked isocyanate composition B-6
A blocked polyisocyanate composition B-6 was obtained in the same manner as in comparative example 5-1 except that PV-6 was used instead of the polyisocyanate composition PV-1.
The calculated NCO content of the resulting blocked isocyanate composition B-6 was 10.6% by mass. Evaluation was then performed based on the above method. The results are shown in table 5 below.
Comparative examples 5to 4 production of blocked isocyanate composition B-7
A nitrogen atmosphere was formed in a 4-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen-blowing tube and a dropping funnel, and 1200g of the polyisocyanate composition PV-1200g and 127g of butyl acetate were charged to adjust the temperature to 70 ℃. Subsequently, methyl ethyl ketoxime (96g, 100 mol%) was added dropwise and held for 2 hours in a 4-neck flask. Subsequently, it was confirmed that the NCO content was 0.0% by mass, and a blocked isocyanate composition B-7 having a solid content of 70% by mass was obtained.
The calculated NCO content of the resulting blocked isocyanate composition B-7 was 10.9% by mass. Evaluation was then performed based on the above method. The results are shown in table 5 below.
Comparative examples 5to 5 production of blocked isocyanate composition B-8
A blocked polyisocyanate composition B-8 was obtained in the same manner as in comparative example 5-1 except that PV-7 was used instead of the polyisocyanate composition PV-1.
The calculated NCO content of the resulting blocked isocyanate composition B-8 was 10.9% by mass. Evaluation was then performed based on the above method. The results are shown in table 5 below.
Comparative examples 5to 6 production of blocked isocyanate composition B-9
A blocked polyisocyanate composition B-9 was obtained in the same manner as in comparative example 5-1 except that PV-8 was used instead of the polyisocyanate composition PV-1.
The calculated NCO content of the resulting blocked isocyanate composition B-9 was 11.0% by mass. Evaluation was then performed based on the above method. The results are shown in table 5 below.
[ Table 7]
Figure BDA0002441845570001351
As is clear from Table 5, it was confirmed that the blocked polyisocyanate compositions B-3 to B-5 (examples 5-1, 5-2 and 5-3) can form coating films excellent in acid resistance and methanol resistance at high temperatures of 40 to 60 ℃.
On the other hand, in the blocked polyisocyanate compositions B-1 to B-2 and B-6 to B-9 (comparative examples 5-1 to 5-6), a coating film having good acid resistance and good methanol resistance at a high temperature of 40 to 60 ℃ could not be obtained.
From the above, it was confirmed that the blocked polyisocyanate composition according to embodiment 5 can form a coating film having excellent acid resistance and methanol resistance under high temperature conditions.
Industrial applicability
In embodiment 1 of the present invention, a polyisocyanate composition is provided in which an HDI-derived odor is suppressed and which has excellent color stability and viscosity stability. Also disclosed is a coating composition which contains such a polyisocyanate composition and has good solvent dilutability. Also disclosed is a coating film which contains such a coating composition and has excellent chemical resistance.
Embodiment 2 of the present invention provides a coating film having a low viscosity and excellent in re-coating adhesion, durability when sprayed with salt water, and stain resistance, a polyisocyanate composition capable of forming the coating film, and a coating composition containing the polyisocyanate composition.
In embodiment 3 of the present invention, there are provided a coating film in which an odor derived from HDI is suppressed and which has excellent adhesion to a substrate and excellent stain resistance, a polyisocyanate composition capable of forming the coating film, and a coating composition containing the polyisocyanate composition.
In embodiment 4 of the present invention, a cured product having excellent hardness and water resistance, a polyisocyanate composition capable of forming the cured product, and an aqueous coating composition containing the polyisocyanate composition are provided.
In embodiment 5 of the present invention, a coating film excellent in acid resistance and methanol resistance under high temperature conditions, a blocked polyisocyanate composition capable of forming the coating film, and a coating composition containing the blocked polyisocyanate composition are provided.

Claims (24)

1. A polyisocyanate composition which satisfies the following conditions 1) and 2) when stored at 50 ℃ for 1 month,
1) the polyisocyanate composition before storage has a 1, 6-hexamethylene diisocyanate content of 0.001 to 0.1 mass%;
2) the content of 1, 6-hexamethylene diisocyanate in the polyisocyanate composition after storage is 0.001 to 0.1 mass%.
2. The polyisocyanate composition according to claim 1 comprising a polyisocyanate having isocyanurate groups derived from an aliphatic diisocyanate containing 1, 6-hexamethylene diisocyanate,
in the condition 1), the 1, 6-hexamethylene diisocyanate content in the polyisocyanate composition before storage is 0.01 to 0.1 mass%;
in the condition 2), the content of 1, 6-hexamethylene diisocyanate in the polyisocyanate composition after storage is 0.01 to 0.1 mass%;
the polyisocyanate composition further satisfies the condition 3) that the difference between the 1, 6-hexamethylene diisocyanate contents in the polyisocyanate composition before and after storage is 0.08% by mass or less.
3. The polyisocyanate composition according to claim 2, wherein the polyisocyanate composition before storage under condition 1) has a 1, 6-hexamethylene diisocyanate content of 0.01 to 0.08% by mass.
4. The polyisocyanate composition according to claim 2 or 3, wherein the viscosity of the polyisocyanate composition is 1000 mPas or more and 5000 mPas or less.
5. A coating composition comprising the polyisocyanate composition according to any one of claims 2to 4.
6. A coating film formed by the coating composition according to claim 5.
7. The polyisocyanate composition according to claim 1 comprising a polyisocyanate having isocyanurate groups derived from an aliphatic diisocyanate containing 1, 6-hexamethylene diisocyanate,
the ratio of the component having a number average molecular weight of 700 or less to the total mass of the polyisocyanate composition is 70% by mass or more, and
in the above condition 2), the content of 1, 6-hexamethylene diisocyanate in the polyisocyanate composition after storage is 0.01% by mass or more and 0.1% by mass or less.
8. A coating composition comprising the polyisocyanate composition according to claim 7 and at least one member selected from the group consisting of acrylic polyols having a hydroxyl value of 10 to 200mgKOH/g, and polyester polyols having a hydroxyl value of 10 to 200 mgKOH/g.
9. A coating film formed by the coating composition according to claim 8.
10. The polyisocyanate composition according to claim 1 comprising a polyisocyanate having isocyanurate groups and biuret groups derived from an aliphatic diisocyanate containing 1, 6-hexamethylene diisocyanate,
when the molar amount of the isocyanurate group is a, the molar amount of the uretdione group is B, the molar amount of the iminooxadiazinedione group is C, and the molar amount of the biuret group is D, D/(a + B + C + D) is 0.50 or more.
11. A coating composition comprising the polyisocyanate composition according to claim 10 and at least one member selected from the group consisting of acrylic polyols having a hydroxyl value of 10 to 200mgKOH/g, and polyester polyols having a hydroxyl value of 10 to 200 mgKOH/g.
12. A coating film formed by the coating composition according to claim 11.
13. The polyisocyanate composition according to claim 1, which comprises a diisocyanate comprising 1, 6-hexamethylene diisocyanate and a polyisocyanate represented by the following general formula (IV-I),
the condition 1) is that the content of diisocyanate in the polyisocyanate composition is 0.002 mass% or more and 0.1 mass% or less, and
the condition 2) is a condition in which the content of the diisocyanate in the polyisocyanate composition is 0.002 mass% or more and 0.1 mass% or less,
(X11-Y11)n11-R11-(NCO)n12(IV-I)
in the general formula (IV-I), R11Is a residue obtained by removing isocyanate groups from a polyisocyanate derived from at least 1 diisocyanate selected from the group consisting of aliphatic diisocyanates and alicyclic isocyanates, X11Is a residue of a compound having an active hydrogen group and a hydrophilic group, Y11Is a bonding structure of an isocyanate group and the active hydrogen group, (n11+ n12) is an integer of 2 or more and 10 or less, n11 and n12 are both not 0, and n11/(n11+ n12) × 100 is 1 or more and 50 or less.
14. The polyisocyanate composition according to claim 13, wherein the compound having an active hydrogen group and a hydrophilic group is at least one selected from the group consisting of an anionic compound, a cationic compound and a nonionic compound.
15. The polyisocyanate composition according to claim 14, wherein the compound having an active hydrogen group and a hydrophilic group is the anionic compound,
the anionic compound is at least one selected from the group consisting of a compound having a carboxylic acid group, a compound having a phosphoric acid group, and a compound having a sulfonic acid group.
16. The polyisocyanate composition according to claim 15, wherein the anionic compound is the compound having a sulfonic acid group,
the compound having a sulfonic acid group is at least one selected from the group consisting of a sulfonic acid having a hydroxyl group and a sulfonic acid having an amino group.
17. The polyisocyanate composition according to claim 14, wherein the compound having an active hydrogen group and a hydrophilic group is the cationic compound,
the cationic compound is a compound having an amino group and is neutralized with a compound having an anionic group.
18. The polyisocyanate composition according to claim 14, wherein the compound having an active hydrogen group and a hydrophilic group is the nonionic compound,
the nonionic compound is polyalkylene glycol ether represented by the following general formula (IV-II),
HO-(R21-O)n21-R22(IV-II)
in the general formula (IV-II), R21Is alkylene having 1to 4 carbon atoms, R22Is an alkyl group having 1to 8 carbon atoms, and n21 is an integer of 3 to 30 inclusive.
19. The polyisocyanate composition of any one of claims 13 to 18 wherein the polyisocyanate has isocyanurate groups and allophanate groups,
the ratio of the molar amount of isocyanurate groups to the total molar amount of isocyanate groups and allophanate groups in the polyisocyanate composition (isocyanurate groups/(isocyanurate + allophanate groups)) is 0.80 or more and less than 0.99.
20. A coating composition comprising the polyisocyanate composition of any one of claims 13 to 19 and water.
21. A cured product formed from the coating composition of claim 20.
22. A blocked polyisocyanate composition comprising a blocked polyisocyanate and a blocked diisocyanate,
the blocked polyisocyanate is obtained by blocking the isocyanate group of a polyisocyanate derived from an aliphatic diisocyanate containing 1, 6-hexamethylene diisocyanate with a blocking agent,
the content of the blocked diisocyanate is 0.01 mass% or more and 0.16 mass% or less with respect to the total mass of the blocked polyisocyanate composition.
23. A coating composition comprising the blocked polyisocyanate composition according to claim 22 and at least one member selected from the group consisting of acrylic polyols having a hydroxyl value of 10 to 200mgKOH/g, and polyester polyols having a hydroxyl value of 10 to 200 mgKOH/g.
24. A coating film formed by the coating composition of claim 23.
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