JPWO2018212334A1 - Polyisocyanate composition - Google Patents

Abstract

The polyisocyanate composition of the present invention includes a polyisocyanate obtained from one or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates, and the following general formula (1) (wherein R1 Represents an alkyl group having 1 to 10 carbon atoms which may contain a hydroxyl group, or an aryl group having 6 to 10 carbon atoms which may contain a hydroxyl group, and the plurality of R1s have the same structure. The polyisocyanate contains an isocyanurate group and is converted to tributyl phosphate of the diphosphate tetraester relative to the total mass of the polyisocyanate composition. The concentration at is 4 mass ppm to 10000 mass ppm. [Chemical 1]

Description

The present invention relates to a polyisocyanate composition.
This application claims priority based on Japanese Patent Application No. 2017-100362 for which it applied to Japan on May 19, 2017, and uses the content here.

  Aliphatic and / or alicyclic polyisocyanate compositions are known as non-yellowing polyisocyanates. For example, when the composition is used as a curing agent for urethane-based paints, the resulting coating film has excellent physical properties such as weather resistance and chemical resistance. It is extremely useful in such fields. In these paint fields, since the appearance is important, a solvent-diluted urethane two-component curable paint is used.

  Patent Document 1 discloses that a polyisocyanate composition containing an isocyanurate group having a phosphorus concentration of 0.1 to 20 ppm by mass is excellent in both stability and storage stability in a humid environment. Has been.

JP 2004-175888 A

  Curing agents that are raw materials for solvent-diluted urethane-based two-component curable paints are often diluted and stored in advance with a solvent, but the problem of turbidity is caused by contact with moisture during painting or storage. Had. In the composition described in Patent Document 1, gelation under saturated humidity conditions and turbidity under a sealed nitrogen atmosphere when polyisocyanate is stored after being diluted with a solvent are suppressed, but turbidity suppression under moisture conditions is suppressed. Not achieved. Another problem is that the curing agent is colored by heating.

  An object of the present invention is to provide a polyisocyanate composition in which turbidity under moisture conditions is suppressed and heat resistance is also improved.

  The present inventors proceeded with studies to solve the above-mentioned problems, and an aliphatic and / or alicyclic polyisocyanate composition containing an isocyanurate group having a diphosphoric acid tetraester concentration of 4 ppm to 10000 ppm by mass. However, it was found that turbidity was suppressed even under moisture conditions and the heat resistance was improved, and the present invention was made.

That is, the present invention has the following configuration.
[1] A polyisocyanate obtained from one or two or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates, and a diphosphate tetraester represented by the following general formula (1),
The polyisocyanate contains isocyanurate groups;
The polyisocyanate composition whose density | concentration in conversion of tributyl phosphoric acid of the said diphosphoric acid tetraester with respect to the total mass of a polyisocyanate composition is 4 mass ppm-10000 mass ppm.

[Wherein, R ₁ represents an alkyl group having 1 to 10 carbon atoms which may contain a hydroxyl group, or an aryl group having 6 to 10 carbon atoms which may contain a hydroxyl group, wherein a plurality of R ₁ are The structures may be the same or different from each other. ]
[2] The polyisocyanate composition according to [1], wherein the concentration of the diphosphate tetraester in terms of tributyl phosphate relative to the total mass of the polyisocyanate composition is 20 ppm to 10,000 ppm.
[3] The polyisocyanate composition according to [2], wherein the concentration of the diphosphate tetraester in terms of tributyl phosphate relative to the total mass of the polyisocyanate composition is 100 mass ppm to 10000 mass ppm.
[4] The polyisocyanate contains an isocyanurate group, and the molar ratio of the isocyanurate structure (X) to the allophanate structure (Y) is (Y) / (X) = 2.0 / 100 or more and 50/100 or less. The polyisocyanate composition according to any one of [1] to [3].
[5] The polyisocyanate composition according to [4], wherein a molar ratio of the isocyanurate structure (X) to the allophanate structure (Y) is (Y) / (X) = 10/100 or more and 50/100 or less. .
[6] The polyisocyanate contains an isocyanurate group, and the molar ratio of the isocyanurate structure (X) to the uretdione structure (Z) is (Z) / (X) = 2.0 / 100 or more and 60/100. The polyisocyanate composition according to any one of [1] to [5], which is:
[7] The polyisocyanate composition according to any one of [1] to [6], wherein the polyisocyanate contains an isocyanurate group and has a viscosity at 25 ° C. of 900 mPa · s or less.
[8] In the general formula (1), R ₁ represents an alkyl group having 1 to 10 carbon atoms which may contain a hydroxyl group, and the poly according to any one of [1] to [7]. Isocyanate composition.
[9] The polyisocyanate composition according to [8], wherein the alkyl group is linear.
[10] The poly according to any one of [1] to [9], wherein the total chlorine content in the polyisocyanate composition is 160 ppm by mass or less with respect to the total mass of the polyisocyanate composition. Isocyanate composition.

  ADVANTAGE OF THE INVENTION According to this invention, the turbidity in moisture conditions is suppressed and the polyisocyanate composition with favorable heat resistance can be provided.

  Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. In addition, this invention is not limited to the following this embodiment. The present invention can be appropriately modified within the scope of the gist.

  The polyisocyanate composition of the present embodiment is represented by a polyisocyanate obtained from one or two or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates, and the following general formula (1). The diisocyanate tetraester is contained, the polyisocyanate contains an isocyanurate group, and the concentration of the diphosphate tetraester in terms of tributyl phosphate with respect to the total mass of the polyisocyanate composition is 4 mass ppm to 10000 mass ppm (1 mass). %).

In General Formula (1), the C1-C10 alkyl group which may contain a hydroxyl group, or the C6-C10 aryl group which may contain a hydroxyl group is represented. A plurality of R ₁ in the general formula (1) may have the same structure or different from each other.

  The polyisocyanate composition of the present embodiment has the above-described configuration, thereby suppressing turbidity of the polyisocyanate composition under moisture conditions and improving heat resistance.

  The aliphatic or alicyclic diisocyanate monomer that can be used to form the polyisocyanate of this embodiment is a compound that does not contain a benzene ring in its structure. As the aliphatic diisocyanate monomer, those having 4 to 30 carbon atoms are preferable. Specifically, tetramethylene-1,4-diisocyanate, pentamethylene-1,5-diisocyanate, hexamethylene diisocyanate (hereinafter referred to as HDI). 2,2,4-trimethyl-hexamethylene-1,6-diisocyanate, lysine diisocyanate, and the like. As the alicyclic diisocyanate, those having 8 to 30 carbon atoms are preferable. Specifically, isophorone diisocyanate (hereinafter referred to as IPDI), 1,3-bis (isocyanatemethyl) -cyclohexane, 4,4′-dicyclohexylmethane. A diisocyanate etc. can be mentioned. Of these, HDI is preferred from the viewpoint of the weather resistance of the resulting coating film and the ease of industrial availability. Two or more of the above compounds can be used in combination.

  Moreover, as a raw material of the polyisocyanate used for the aliphatic and / or alicyclic polyisocyanate composition of the present embodiment, a divalent to hexavalent alcohol can be used in addition to the diisocyanate monomer. Examples of such a divalent to hexavalent alcohol (polyol) include non-polymerized polyols and polymerized polyols. A non-polymerized polyol is a polyol that does not undergo polymerization, and a polymerized polyol is a polyol obtained by polymerizing monomers.

  Non-polymerized polyols include diols, triols, tetraols and the like. Examples of diols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1, 3-butanediol, 1,4-butanediol, 2,3-butanediol, 2-methyl-1,2-propanediol, 1,5-pentanediol, 2-methyl-2,3-butanediol, 1, 6-hexanediol, 1,2-hexanediol, 2,5-hexanediol, 2-methyl-2,4-pentanediol, 2,3-dimethyl-2,3-butanediol, 2-ethyl-hexanediol, 1,2-octanediol, 1,2-decanediol, 2,2,4-to Methyl pentanediol, 2-butyl-2-ethyl-1,3-propanediol, and 2,2-diethyl-1,3-propanediol. Examples of the triols include glycerin and trimethylolpropane. Examples of tetraols include pentaerythritol.

  Examples of the polymerization polyol include polyester polyol, polyether polyol, acrylic polyol, and polyolefin polyol.

  As the polyester polyol, for example, a dibasic acid selected from the group of carboxylic acids such as succinic acid, adipic acid, sebacic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, or a mixture thereof Polyester polyols obtained by a condensation reaction with a polyhydric alcohol alone or in a mixture selected from the group consisting of ethylene glycol, propylene glycol, diethylene glycol, neopentyl glycol, trimethylolpropane, glycerin and the like, and for example, ε-caprolactone and many And polycaprolactones obtained by ring-opening polymerization using a monohydric alcohol.

  Examples of polyether polyols include hydroxides such as lithium, sodium and potassium, strong basic catalysts such as alcoholates and alkylamines, and complex metal cyanide complexes such as metal porphyrins and hexacyanocobaltate zinc complexes. Polyether polyols obtained by random or block addition of alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, cyclohexene oxide, styrene oxide or the like to single or mixture of polyvalent hydroxy compounds, and further ethylenediamine Polyether polyols obtained by reacting alkylene oxide with polyamine compounds such as aldehydes, and obtained by polymerizing acrylamide etc. using these polyethers as a medium So-called polymer polyols and the like are included.

  Using the diisocyanate monomer and optionally the divalent to hexavalent alcohol (polyol), the polyisocyanate used in the aliphatic and / or alicyclic polyisocyanate composition of the present embodiment is derived. The polyisocyanate preferably contains an isocyanurate group. A coating film obtained by curing polyisocyanate having an isocyanurate group has good weather resistance and can achieve high coating film hardness.

  In addition to the isocyanurate structure, this polyisocyanate can simultaneously contain, for example, an allophanate structure, a uretdione structure, an oxadiazinetrione structure, an iminooxadiazinedione structure, and the like.

In particular, in the allophanate structure, the molar ratio between the isocyanurate structure (X) and the allophanate structure (Y) is preferably (Y) / (X) = 2.0 / 100 or more and 50/100 or less, (Y) / (X) = 10/100 or more and 50/100 or less is more preferable.
By making the said ratio more than the said lower limit, compatibility with the low polar organic solvent of the polyisocyanate composition obtained becomes favorable. The low polarity organic solvent is an organic solvent containing an aliphatic or alicyclic hydrocarbon solvent as a main component, but contains an aromatic hydrocarbon solvent, an ester solvent, an ether solvent or the like. Also good. Examples of such organic solvents include, in addition to methylcyclohexane, ethylcyclohexane, mineral spirit, turpentine oil, etc., HAWS (manufactured by Shell Japan), Essonaphtha No. 6 (manufactured by ExxonMobil Chemical), LAWS (manufactured by Shell Japan), Pegasol 3040 (manufactured by ExxonMobil Chemical), A Solvent (Shin Nippon Petrochemical Co., Ltd.), Clensol (manufactured by Nippon Petrochemical Co., Ltd.), mineral spirit A ( Shin Nippon Petrochemical Co., Ltd.), Hyalom 2S (Shin Nippon Petrochemical Co., Ltd.), etc., or at least one of these organic solvents and, if necessary, aromatic hydrocarbon solvents, ester solvents, ethers What mixed the solvent etc. is mentioned.
On the other hand, the crosslinkability of a coating film becomes more favorable by making the said ratio below into the said upper limit.

Further, in the uretdione structure, the molar ratio of the isocyanurate structure (X) and the uretdione structure (Z) is preferably (Z) / (X) = 2.0 / 100 or more and 60/100 or less. Z) / (X) = 3.0 / 100 or more and 60/100 or less is more preferable.
By setting the ratio to the above lower limit or more, when the obtained polyisocyanate composition is used in the upper layer of the multilayer coating film, the penetration into the lower layer becomes good, and the multilayer coating film excellent in solvent resistance is obtained. can get.
By making the said ratio below the said upper limit, the crosslinking density of the coating film using the polyisocyanate composition obtained becomes high, hardness is high, and a tough coating film is obtained.

  The production of a polyisocyanate having an isocyanurate group is carried out, for example, preferably by using a catalyst to carry out an isocyanurate conversion reaction (trimerization reaction) of the diisocyanate monomer, and when the predetermined conversion rate is reached, the reaction is stopped. This is done by removing

  As the isocyanuration reaction catalyst used in this case, a catalyst having basicity is generally preferred. Specifically, (1) organic weak acid salts of tetraalkylammonium such as tetramethylammonium and tetraethylammonium, such as hydroxide, acetic acid and capric acid, and (2) e.g. trimethylhydroxypropylammonium and trimethylhydroxyethylammonium , Organic weak acid salts of hydroxyalkyl ammonium such as triethylhydroxypropylammonium and triethylhydroxyethylammonium, such as hydroxide, acetic acid and capric acid, (3) alkylcarboxylic acids such as acetic acid, caproic acid, octylic acid and myristic acid (4) Metal alcoholates such as sodium and potassium, (5) Aminosilyl group-containing compounds such as hexamethyldisilazane, (6) Manni Human bases, (7) in combination with tertiary amines with epoxy compounds, (8) For example, phosphorus compounds such as tributyl phosphine. The usage-amount of these catalysts is selected from the range of 10 mass ppm-10000 mass ppm with respect to the total mass of the diisocyanate and polyol which are raw materials. In order to complete the reaction, these catalysts are deactivated by adding an acidic substance such as phosphoric acid or acidic phosphate ester that neutralizes the catalyst, thermal decomposition, chemical decomposition, or the like.

The yield of polyisocyanate by such an isocyanuration reaction is usually 10 to 70% by mass. Polyisocyanates obtained with high yields tend to have higher viscosities.
The viscosity of the polyisocyanate is preferably 900 mPa · s or less and more preferably 800 mPa · s or less at 25 ° C. When the viscosity is not more than the above value, the workability during blending of the paint is excellent, and the surface smoothness of the coating film is also improved. On the other hand, the viscosity of the polyisocyanate at 25 ° C. is not particularly limited, but is preferably 20 mPa · s or more. When the viscosity is not less than the above lower limit, the crosslinkability of the coating film becomes better.

  The reaction temperature of the isocyanuration reaction is usually 50 to 200 ° C, preferably 50 to 150 ° C. The reaction easily proceeds at a reaction temperature of 50 ° C. or higher. On the other hand, unfavorable side reactions such as product coloring can be suppressed by a reaction temperature of 200 ° C. or lower.

  After completion of the reaction, the diisocyanate monomer is removed by a thin film evaporator, extraction or the like. The concentration of unreacted diisocyanate remaining in the obtained polyisocyanate may be 3% by mass or less, preferably 1% by mass or less, more preferably 0.5% by mass or less.

In the polyisocyanate composition of the present embodiment, the diphosphoric acid tetraester represented by the following general formula (1) is 4 mass ppm to 10,000 in terms of tributyl phosphoric acid with respect to the total mass of the polyisocyanate composition. Contains mass ppm. In the general formula (1), R ₁ represents an alkyl group having 1 to 10 carbon atoms which may contain a hydroxyl group, or an aryl group having 6 to 10 carbon atoms which may contain a hydroxyl group. A plurality of R ₁ in one molecule may have the same structure or different from each other.

When R _{1 in the} general formula (1) is an alkyl group having 1 to 10 carbon atoms, specifically, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group , Isoamyl group, cyclopentyl group, hexyl group, 3,3-dimethylbutyl group, cyclohexyl group, heptyl group, methylhexyl group, ethylpentyl group, octyl group, methylheptyl group, ethylhexyl group, nonyl group, methyloctyl group , Ethyl heptyl group, decyl group, methylnonyl group, and ethyloctyl group. When R _{1 in the} general formula (1) is a C 1-10 alkyl group containing a hydroxyl group, the position of the hydrogen atom substituted with the hydroxyl group in the alkyl group is not particularly limited. One alkyl group may have one hydroxyl group or two or more hydroxyl groups.

When R _{1 in the} general formula (1) is an aryl group having 6 to 10 carbon atoms, specific examples include a phenyl group, a naphthyl group, and an indenyl group. When R _{1 in the} general formula (1) is an aryl group having 6 to 10 carbon atoms including a hydroxyl group, the position of the hydrogen atom substituted with the hydroxyl group in the aryl group is not particularly limited. One aryl group may have one hydroxyl group, or two or more hydroxyl groups.

In the general formula (1), R ₁ is preferably an alkyl group having 1 to 10 carbon atoms which may contain a hydroxyl group, and the plurality of R ₁ may have the same structure as each other and are different from each other. It may be. Although it does not specifically limit as diphosphoric acid tetraester of this embodiment, For example, the compound which has a structure represented by following General formula (2) or following General formula (3) is mentioned. The tetrabutyl diphosphate represented by the general formula (2) and the tetra-2-ethylhexyl diphosphate represented by the general formula (3) are produced from industrial production of dibutyl phosphoric acid and di-2-ethylhexyl phosphoric acid. Therefore, the synthesis is easy. The synthesis method will be described later.
Furthermore, in general formula (1), R ₁ is more preferably a linear alkyl group having 1 to 10 carbon atoms which may contain a hydroxyl group, and the plurality of R ₁ have the same structure as each other. May be different. Although it does not specifically limit as the said diphosphate tetraester, For example, the tetrabutyl diphosphate represented by following General formula (2) is mentioned. The polyisocyanate composition containing the diphosphoric acid tetraester tends to suppress turbidity more.

  The density | concentration of the diphosphoric acid tetraester contained in a polyisocyanate composition is 4 mass ppm-10000 mass ppm in conversion of tributyl phosphoric acid, It is preferable that it is 20 mass ppm-10000 mass ppm, 100 mass ppm-10000 mass ppm. It is more preferable that it is 100 mass ppm-1200 mass ppm. If it is 4 mass ppm to 20 mass ppm, the turbidity of the polyisocyanate composition and turbidity suppression under moisture conditions and heat resistance are both improved, and particularly excellent in turbidity suppression under moisture conditions. In 20 mass-50 mass ppm, the turbidity of a polyisocyanate composition and the turbidity suppression on moisture conditions and the improvement of heat resistance are compatible, and it is excellent in turbidity suppression especially on moisture conditions. 50 mass to 100 mass ppm achieves both turbidity of the polyisocyanate composition and turbidity suppression under moisture conditions and improvement of heat resistance, and particularly excellent heat resistance improvement. Excellent in improving properties.

  The diphosphate tetraester can be obtained by heating the diphosphate. The heating temperature is preferably 80 to 180 ° C., but is not limited thereto. After heating, it can be separated and purified by column chromatography or liquid chromatography to obtain diphosphoric acid tetraester.

The total chlorine content in the aliphatic and / or alicyclic polyisocyanate composition of this embodiment is preferably 160 mass ppm or less, and more preferably 140 mass ppm or less. By setting the total amount of chlorine to the above upper limit or less, even when the polyisocyanate obtained is treated at a high temperature, the pot life (thickening) of the coating composition containing the polyisocyanate is long and the operability is improved.
On the other hand, the lower limit of the total chlorine content in the polyisocyanate composition is not particularly limited, but is preferably 10 mass ppm. Generation | occurrence | production of the turbidity especially on moisture condition of a polyisocyanate composition is suppressed as the total chlorine amount is more than the said lower limit.

  The aliphatic and / or alicyclic polyisocyanate composition of the present embodiment can be used by mixing with an organic solvent. As an organic solvent to be diluted, aromatic hydrocarbons such as toluene, xylene, Solvesso 100, 150 (Ciel Petrochemical Co., Ltd.), Swazol 1000, 1500 (Maruzen Petroleum Co., Ltd.); n-hexane, heptane, octane , Mineral spirits, aliphatic or alicyclic hydrocarbons such as methylcyclohexane; ester solvents such as ethyl acetate, butyl acetate, isobutyl acetate, cellosolve acetate, 3-methoxybutyl acetate; acetone, methyl ethyl ketone, cyclohexanone, etc. A ketone solvent or the like is used. The solid content of the diluted solution obtained by mixing the polyisocyanate composition of the present embodiment with an organic solvent is preferably 20 to 80% by mass with respect to the total mass of the diluted solution, but is not limited thereto.

The aliphatic and / or alicyclic polyisocyanate composition of the present embodiment can be used by mixing with triisocyanate. As the triisocyanate, 1,3,6-hexamethylene triisocyanate (hereinafter sometimes referred to as “HTI”), bis (2-isocyanatoethyl) 2-isocyanatoglutarate (hereinafter referred to as “GTI”). Lysine triisocyanate (hereinafter sometimes referred to as “LTI”) and the like.
The amount of triisocyanate when the polyisocyanate composition of the present embodiment is mixed with triisocyanate is preferably 1 to 90% by mass with respect to the total mass of the polyisocyanate composition, but this is not limited. .

  Further, in the polyisocyanate composition of the present invention, a curing accelerator, a pigment, a leveling material, an antioxidant, an ultraviolet absorber, a light stabilizer, a plasticizer, a surface that accelerates a urethanation reaction, etc., depending on the purpose. Various additives such as an activator can also be mixed and used.

  The polyisocyanate composition of the present invention has a wide range of fields such as two-component polyurethane paints, sealing materials, adhesives, inks, coating agents, casting materials, elastomers, foams, plastic raw materials, fiber treatment agents, and one-component curable polyisocyanates. Can be used in

  Hereinafter, although this embodiment is demonstrated in more detail based on an Example and a comparative example, this embodiment is not limited at all by the following examples.

(Turbidity of polyisocyanate composition (NTU))
The turbidity of the polyisocyanate composition was measured with the following apparatus.
Apparatus: Desktop turbidimeter 2100AN (HACH)

(Moisture stability evaluation)
The polyisocyanate composition of each example (5.0 g) and toluene (5.0 g) were mixed and stored at 23 ° C. and saturated humidity for 48 hours. The sample after storage was visually evaluated with turbidity measured by visible spectrophotometry (hereinafter referred to as UV).

(Turbidity (transmittance))
The turbidity of the mixed solution of the polyisocyanate composition and toluene was measured as a transmittance (%) at 550 nm by UV measurement using the following apparatus.
Apparatus: JASCO V-650

(Visual evaluation)
The turbidity of the sample was evaluated visually. The evaluation criteria were as follows.
◎: Not turbid at all ○: Not turbid △: Slightly turbid (Practical no problem)
×: Cloudy

(Heat resistance evaluation)
30 g of the polyisocyanate composition of each example was placed in a heat-resistant bottle and heated at 170 ° C. for 3 hours. The UV (430 nm) transmittance of the sample before and after heating was measured, and the decrease in chromaticity was evaluated.

(Measurement of diphosphate tetraester)
The concentration of diphosphate tetraester in the polyisocyanate was measured using a liquid chromatograph mass spectrometer (hereinafter referred to as LC / MS). A calibration curve was prepared with tributyl phosphate. In this section, the concentration of diphosphoric acid tetraester is in terms of tributyl phosphoric acid.

  The polyisocyanate composition of each example was prepared in a solution of about 50 mg / mL with methanol and allowed to stand overnight or longer. These solutions were diluted 2-fold with water, and the centrifugal supernatant was measured by LC / MS.

LC equipment: Waters, UPLC
Column: Imtakt, Cadenza CD-C18HT (2 mm ID x 30 mm)
Column temperature: 40 ° C
Flow rate: 0.3 mL / min Mobile phase A = water (0.1% by weight formic acid)
Mobile phase B = acetonitrile (0.1% by weight formic acid)
Gradient: 0 to 5 minutes (A: 98 mass%, B: 2 mass%), 5 to 10 minutes (A: 0 mass%, B: 100 mass%), 10 to 15 minutes (A: 98 mass%, B: 2% by mass)
MA equipment: Waters, Synapt G2
Ionization: ESI +

(Mole ratio measurement of allophanate structure (Y) / isocyanurate structure (X))
A CDCl ₃ solution of a polyisocyanate composition was prepared and subjected to NMR measurement under the following conditions.
⁽¹ H-NMR measurement conditions)
Equipment: Bruker Biospin Avance 600
Observation nucleus (frequency): 1H (600MHz)
Solvent (concentration): CDCl ₃ (5 mass / volume%)
Accumulation count: 256 times Chemical shift criteria: CHCl ₃ 7.26 ppm

Next, from the obtained measurement results, the integral value of the following signal is divided by the number of hydrogen being measured, and the isocyanurate structure (X) is defined as “100” from that value. ) Molar ratio (Y) / (X) was calculated.
Isocyanurate structure (X): integral value around 3.9 ppm ÷ 6
Allophanate structure (Y): integral value around 7.5 ppm / 1
(Measurement of molar ratio of uretdione structure (Z) / isocyanurate structure (X))
A CDCl ₃ solution of a polyisocyanate composition was prepared and subjected to NMR measurement under the following conditions.

( ^13C -NMR measurement conditions)
Equipment: Bruker Biospin Avance 600
Observation (frequency): 13C (150 MHz)
Solvent (concentration): CDCl ₃ (60 mass / volume%)
Integration count: 10,000 times Chemical shift standard: CDCl ₃ 77 ppm

Next, from the obtained measurement results, the integral value of the following signal is divided by the number of carbons being measured, and the isocyanurate structure (X) is defined as “100” from that value. ) Molar ratio (Z) / (X) was calculated.
Isocyanurate structure (X): integral value around 148 ppm ÷ 3
Uretodione structure (Z): integral value near 157 ppm / 2

(Measurement of total chlorine content)
The polyisocyanate composition was subjected to elemental analysis by the AQF-IC method, and the total chlorine content (mass ppm) was calculated. Measuring equipment and conditions are shown below.

(Pretreatment device)
Automatic combustion apparatus: AQF-100 Combustion conditions manufactured by Mitsubishi Analytech Co., Ltd .: 900 to 1000 ° C. About 50 mg of a sample is burned.

(Analysis equipment)
Ion chromatograph: Model ICS-1500 (manufactured by Thermo Fisher Scientific)
Separation column: AS12A (manufactured by Thermo Fisher Scientific)
Guard column: AG12 (manufactured by Thermo Fisher Scientific)
Suppressor: AERS-500 (manufactured by Thermo Fisher Scientific)

(Measurement of gel fraction of coating film)
A polyisocyanate composition and an acrylic polyol (trade name “SETALUX1767” of Allnex Co., Ltd., resin hydroxyl value of 150 mgKOH / g, resin content 65%) so that the molar ratio of isocyanate group / hydroxyl group (NCO / OH) is equivalent. Blended into Subsequently, the coating composition diluted with butyl acetate to a resin solid content of 50% by mass was applied to a dry film thickness of 35 μm.
Thereafter, drying was performed at 80 ° C. for 30 minutes to obtain a coating film.
The obtained coating film was immersed in acetone at 23 ° C. for 24 hours. Subsequently, the value which remove | divided the undissolved partial mass by the mass before immersion was calculated | required as a gel fraction [mass%].
It can be judged that the higher the gel fraction, the better the low-temperature curability.
○: 92% or more ×: less than 92%

(Surface smoothness of coating film)
Coating was performed under the same conditions as those for measuring the gel fraction of the coating film to obtain a coating film. The surface smoothness of the coating film was visually evaluated.
◎: There is no undulation on the surface. ○: There is almost no undulation. △: There is a little undulation.

(Hexane dilution)
The polyisocyanate composition was diluted with toluene to a resin solid content of 50% by mass. To 1 g of the toluene solution, n-hexane was added in increments of 0.1 g, and evaluation was performed in terms of mass% of n-hexane at a point immediately before the cloudy point (with the toluene solution being 100 mass%). The greater the mass% of n-hexane, the better the hexane dilution (compatibility with the low polarity organic solvent).
◎: 50% or more ○: 30% or more and less than 50% ×: less than 30%

(Solvent resistance of multilayer coating)
As a first coating composition, an acrylic polyol diluted with butyl acetate / xylene (mass ratio 1/1) so as to have a resin solid content of 18% by mass (trade name “Acrydic A-801” manufactured by DIC) is a dry film. After coating to a thickness of 20 μm, preheating was performed at 80 ° C. for 3 minutes. After preheating, acrylic polyol (trade name “SETALUX1767” of Allnex Co.) and each polyisocyanate composition were blended at a molar ratio of isocyanate group / hydroxyl group (NCO / OH) of 1.5, and the resin solid content with butyl acetate The second coating composition diluted to 50% by mass was applied to a dry film thickness of 35 μm. Thereafter, drying was performed at 80 ° C. for 30 minutes to obtain a multilayer coating film.
A cotton ball was sufficiently impregnated with toluene, placed on the coating film for 2 minutes, and the state of the coating film immediately after was visually evaluated.
◎: No trace remains ○: Trace remains slightly △: Trace remains clearly ×: Blister or cloudiness

(Viscosity evaluation of paint)
The polyisocyanate composition of each example was placed in a heat-resistant bottle and heated at 170 ° C. for 3 hours. The molar ratio of isocyanate group / hydroxyl group (NCO / OH) is equivalent to the polyisocyanate composition before and after heating and acrylic polyol (trade name “SETALUX1767” of Allnex, resin hydroxyl value 150 mgKOH / g, resin content 65%). Formulated to be The viscosity of the coating composition was measured every 3 hours until 12 hours later, and the thickening of the coating was evaluated at the time when the viscosity was twice the initial viscosity.
○: 12 hours or more Δ: 6 hours or more ×: less than 6 hours

(viscosity)
The viscosity of the polyisocyanate composition was measured at 25 ° C. using an E-type viscometer (manufactured by Tokimec). In the measurement, a standard rotor (1 ° 34 ′ × R24) was used. The number of rotations was as follows.

100 rpm (when less than 128 mPa · s)
50 rpm (128 mPa · s or more and less than 256 mPa · s)
20 rpm (256 mPa · s or more and less than 640 mPa · s)
10 rpm (in the case of 640 mPa · s or more and less than 1280 mPa · s)
5 rpm (in the case of 1280 mPa · s or more and less than 2560 mPa · s)

  In addition, the non volatile matter of the polyisocyanate composition manufactured by each Example and each comparative example mentioned later was investigated by the method of the following description, and what was the value of 98 mass% or more was used for the measurement as it was.

(Isocyanate group concentration)
N-dibutylamine was added to the polyisocyanate composition dissolved in toluene, and the isocyanate group concentration in the polyisocyanate composition was determined by potentiometric titration using 1N hydrochloric acid.

(Monomer diisocyanate concentration)
First, a 20 mL sample bottle was placed on a digital balance, and about 1 g of the sample was precisely weighed. Next, 0.03 to 0.04 g of nitrobenzene (internal standard solution) was added and precisely weighed. Furthermore, after adding about 9 mL of ethyl acetate, the lid was firmly mixed well to prepare a sample. The adjustment liquid was quantitatively analyzed by gas chromatography under the following conditions.

Apparatus: SHIMADZU Co., Ltd. GC-8A
Column: Shinwa Kako Co., Ltd. Silicone OV-17
Column oven temperature: 120 ° C
Injection / detector temperature; 160 ° C

(Number average molecular weight)
The number average molecular weight of the polyisocyanate composition was determined as a polystyrene-based number average molecular weight by gel permeation chromatograph (hereinafter referred to as GPC) measurement using the following apparatus.
Equipment: HLC-8120 (manufactured by Tosoh Corporation),
Columns used: TSK GEL SuperH1000, TSK GEL SuperH2000, TSK GEL SuperH3000 (all manufactured by Tosoh Corporation),
Sample concentration: 5 wt / vol%
Carrier: THF,
Detection method: parallax refractometer,
Outflow amount: 0.6 mL / min,
Column temperature: 30 ° C.

  The GPC calibration curves are polystyrene (PSS-06 (Mw50000), BK13007 (Mp = 20000, Mw / Mn = 1.03), PSS-08 (Mw = 9000), PSS manufactured by GL Sciences Inc.) having a molecular weight of 50,000 to 2050. -09 (Mw = 4000) and 5040-35125 (Mp = 2050, Mw / Mn = 1.05)) and isocyanates of hexamethylene diisocyanate polyisocyanate composition (Duranate TPA-100, manufactured by Asahi Kasei Chemicals Corporation) Nurate group trimer to 7mer (isocyanurate trimer molecular weight = 504, isocyanurate pentamer molecular weight = 840, isocyanurate heptamer molecular weight = 1176) and HDI (molecular weight = 168) were prepared as standards. .

(Average number of isocyanate groups)
The average number of isocyanate groups in the polyisocyanate composition was calculated from the following formula based on the number average molecular weight of the polyisocyanate composition measured as described above and the value of the isocyanate group concentration measured as described above.
[Number average functional group number of polyisocyanate composition] = [Number average molecular weight of polyisocyanate composition] × [Isocyanate group concentration (mass%)] / 42

[Synthesis Example 1]
(Synthesis of diphosphate tetraester)
A four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen blowing tube was placed in a nitrogen atmosphere, charged with 50 g of dibutyl phosphoric acid, and heated at 160 ° C. for 4 hours with stirring. The heated reaction product was separated and purified by column chromatography to obtain tetrabutyl diphosphate.

[Synthesis Example 2]
(Synthesis of diphosphate tetraester)
A four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen blowing tube was placed in a nitrogen atmosphere, charged with 50 g of di-2-ethylhexyl phosphoric acid, and heated at 160 ° C. for 4 hours with stirring. The reaction product after heating was separated and purified by column chromatography to obtain tetra-2-ethylhexyl diphosphate.

[Comparative Example 1]
A four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen blowing tube was placed in a nitrogen atmosphere, 100 g of hexamethylene diisocyanate was charged, and the temperature in the reactor was kept at 60 ° C. with stirring. Thereafter, 100.0 mg of isocyanurate-forming catalyst tetramethylammonium acetate (2-butanol 2.0 mass% solution) was added, and when the yield reached 25 mass%, di-2-ethylhexyl phosphate 2.6 mg Was added to stop the reaction. Then, after heating at 100 degreeC for further 1 hour, after cooling to room temperature, the reaction liquid was filtered and the insoluble matter was removed, Then, monomer diisocyanate was removed with the thin film distiller. The polyisocyanate has a molar ratio of allophanate structure (Y) / isocyanurate structure (X) of 2.5, a molar ratio of uretdione structure (Z) / isocyanurate structure (X) of 0.5, and the total chlorine content is The viscosity at 150 ppm, 25 ° C. is 1550 mPa · s, the isocyanate group concentration is 23.1% by mass, the monomer diisocyanate concentration is 0.2% by mass, the number average molecular weight is 560, and the isocyanate group average number is 3.2. The concentration of diphosphoric acid tetraester was 0.3 ppm by mass. The evaluation results are shown in Table 1.

[Comparative Example 2, Examples 1-7]
To the polyisocyanate of Comparative Example 1, tetrabutyl diphosphate synthesized in Synthesis Example 1 and tetra-2-ethylhexyl diphosphate synthesized in Synthesis Example 2 were added at concentrations shown in Table 1, respectively. The evaluation results of each example and comparative example are shown in Table 1.

[Example 8]
A four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen blowing tube was placed in a nitrogen atmosphere, 100 g of hexamethylene diisocyanate was charged, and the temperature in the reactor was kept at 60 ° C. with stirring. Thereafter, 0.35 g of 2-butanol was charged, and then 100.0 mg of isocyanurate-forming catalyst tetramethylammonium acetate (2-butanol 2.0% by mass solution) was added. When the yield reached 21% by mass, The reaction was stopped by adding 2.6 mg of di-2-ethylhexyl phosphoric acid. Then, after further heating at 120 ° C. for 1 hour, the mixture was cooled to room temperature, the reaction solution was filtered to remove insoluble matters, and then the monomer diisocyanate was removed with a thin-film distiller. The resulting polyisocyanate has an allophanate structure (Y) / isocyanurate structure (X) molar ratio of 8.6, a uretdione structure (Z) / isocyanurate structure (X) molar ratio of 2.5, and a total chlorine content of The viscosity at 120 ppm and 25 ° C. is 850 mPa · s, the isocyanate group concentration is 22.9% by mass, the monomer diisocyanate concentration is 0.1% by mass, the number average molecular weight is 550, and the average number of isocyanate groups is 3.1. The concentration of diphosphoric acid tetraester was 0.3 ppm by mass. The evaluation results are shown in Table 1. To the obtained polyisocyanate, tetrabutyl diphosphate synthesized in Synthesis Example 1 was added at a concentration shown in Table 1. The evaluation results are shown in Table 1.

[Example 9]
A four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen blowing tube was placed in a nitrogen atmosphere, 100 g of hexamethylene diisocyanate was charged, and the temperature in the reactor was kept at 60 ° C. with stirring. Thereafter, 0.5 g of 2-butanol was charged, and then 100.0 mg of isocyanurate-forming catalyst tetramethylammonium acetate (2-butanol 2.0 mass% solution) was added. When the yield reached 19 mass%, The reaction was stopped by adding 2.6 mg of di-2-ethylhexyl phosphoric acid. Then, after further heating at 160 ° C. for 1 hour, the mixture was cooled to room temperature, the reaction solution was filtered to remove insoluble matters, and then the monomer diisocyanate was removed with a thin-film distiller. The obtained polyisocyanate has an allophanate structure (Y) / isocyanurate structure (X) molar ratio of 13, a uretdione structure (Z) / isocyanurate structure (X) molar ratio of 25, a total chlorine content of 130 ppm, 25 ° C. Viscosity is 510 mPa · s, isocyanate group concentration is 23.2% by mass, monomer diisocyanate concentration is 0.2% by mass, number average molecular weight is 510, average number of isocyanate groups is 3.0, and diphosphate tetraester The concentration of was 0.3 mass ppm. The evaluation results are shown in Table 1. To the obtained polyisocyanate, tetrabutyl diphosphate synthesized in Synthesis Example 1 was added at a concentration shown in Table 1. The evaluation results are shown in Table 1.

B-DP: Tetrabutyl diphosphate
2EH-DP: tetra-2-ethylhexyl diphosphate

As shown in Table 1, the turbidity of the polyisocyanate compositions of Examples 1 to 9 was 1.1 NTU or less, and the turbidity was good. On the other hand, the turbidity of the polyisocyanate compositions of Comparative Examples 1 and 2 was 1.6 NTU or more, and the turbidity was inferior.
Moreover, the transmittance | permeability (transmittance T550) (%) of 550 nm after storing the polyisocyanate composition of Examples 1-9 for 48 hours on 23 degreeC and saturation humidity conditions is all 87% or more, and is moisture stable. The turbidity in a humid environment was sufficiently suppressed. In contrast, the polyisocyanate compositions of Comparative Examples 1 and 2 had a transmittance at 550 nm after storage in a humid environment of less than 85%.
Furthermore, the reduction width of 430 nm transmittance (transmittance T430) (%) after heat treatment at 170 ° C. for 3 hours of the polyisocyanate compositions of Examples 1 to 9 is slightly smaller than the polyisocyanate composition of Comparative Example 1. The polyisocyanate compositions of Examples 1 to 9 were excellent in heat resistance.

  When the polyisocyanate composition according to the present invention is used as a curing agent for a solvent-diluted urethane-based two-component curable coating, it does not become cloudy even when used under moisture conditions, and has good heat resistance. It can be suitably used in the field.

Claims (10)

A polyisocyanate obtained from one or two or more diisocyanates selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates, and a diphosphate tetraester represented by the following general formula (1):
The polyisocyanate contains isocyanurate groups;
The polyisocyanate composition whose density | concentration in conversion of tributyl phosphoric acid of the said diphosphoric acid tetraester with respect to the total mass of a polyisocyanate composition is 4 mass ppm-10000 mass ppm.

[Wherein, R ₁ represents an alkyl group having 1 to 10 carbon atoms which may contain a hydroxyl group, or an aryl group having 6 to 10 carbon atoms which may contain a hydroxyl group, wherein a plurality of R ₁ are The structures may be the same or different from each other. ]   The polyisocyanate composition of Claim 1 whose density | concentration in the conversion of tributyl phosphoric acid of the said diphosphoric acid tetraester with respect to the total mass of a polyisocyanate composition is 20 mass ppm-10000 mass ppm.   The polyisocyanate composition of Claim 2 whose density | concentration in the conversion of tributyl phosphoric acid of the said diphosphoric acid tetraester with respect to the total mass of a polyisocyanate composition is 100 mass ppm-10000 mass ppm.   The polyisocyanate contains an isocyanurate group, and the molar ratio of the isocyanurate structure (X) to the allophanate structure (Y) is (Y) / (X) = 2.0 / 100 or more and 50/100 or less. Item 4. The polyisocyanate composition according to any one of Items 1 to 3.   The polyisocyanate composition according to claim 4, wherein a molar ratio of the isocyanurate structure (X) to the allophanate structure (Y) is (Y) / (X) = 10/100 or more and 50/100 or less.   The polyisocyanate contains an isocyanurate group, and the molar ratio of the isocyanurate structure (X) to the uretdione structure (Z) is (Z) / (X) = 2.0 / 100 or more and 60/100 or less. The polyisocyanate composition according to any one of claims 1 to 5.   The polyisocyanate composition according to any one of claims 1 to 6, wherein the polyisocyanate contains an isocyanurate group and has a viscosity at 25 ° C of 900 mPa · s or less. In the general formula (1), R ₁ represents an alkyl group having 1 to 10 carbon atoms which may contain a hydroxyl group, the polyisocyanate composition according to any one of claims 1 to 7.   The polyisocyanate composition according to claim 8, wherein the alkyl group is linear.   The polyisocyanate composition according to any one of claims 1 to 9, wherein a total chlorine amount in the polyisocyanate composition is 160 ppm by mass or less with respect to a total mass of the polyisocyanate composition.