JP2016141788A - Polyisocyanate composition, coating composition, and coated-film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyisocyanate composition that is soluble in a low polar organic solvent, exhibits a high coated-film hardness when made to be a coated-film and is less likely to produce a coated-film shrinkage in a wet-on-wet coating step of the coated-film.SOLUTION: Provided is a polyisocyanate composition obtained from an aliphatic diisocyanate and alicyclic diisocyanate, and a mono-alcohol, and in which the mole ratio of the structural unit of the aliphatic diisocyanate to the structural unit of the alicyclic diisocyanate is 75/25 or more and 95/5 or less, and the mono-alcohol contains 2 or more of mono-alcohols having 3 or more and 20 or less carbon atoms.SELECTED DRAWING: None

Description

  The present invention relates to a polyisocyanate composition, a coating composition, and a coating film.

  A polyisocyanate composition obtained from an aliphatic diisocyanate such as hexamethylene diisocyanate (HDI) and an alicyclic diisocyanate such as isophorone diisocyanate (IPDI) is used as, for example, a two-component polyurethane coating composition using this as a curing agent. It has been. The coating film obtained from this two-component polyurethane coating composition exhibits excellent performance in weather resistance, chemical resistance, abrasion resistance, and the like, and thus is widely used as a coating material, ink, adhesive, and the like.

  In recent years, polyisocyanate compositions that are soluble in organic solvents with low polarity (low polarity organic solvents) have been desired. This is because, for example, in architectural coating applications, organic solvents having a high polarity (high polar organic solvents) such as toluene, xylene, ethyl acetate, butyl acetate and the like are concerned with odor and safety. Moreover, when forming a coating film using a polyisocyanate composition for repainting, it is preferable to use a low-polarity organic solvent with weak solubility that does not attack the old coating film.

  For example, Patent Document 1 discloses isocyanurate obtained by urethanizing HDI alone or a mixture of HDI and IPDI with an aliphatic monoalcohol having 6 to 9 carbon atoms in the presence of an isocyanuration catalyst. Polyisocyanate compositions having a structure and an allophanate structure have been proposed. Patent Document 2 contains an aliphatic polyisocyanate having an isocyanurate structure and an allophanate structure obtained from an aliphatic diisocyanate and a diol having 9 to 60 carbon atoms, and an alicyclic polyisocyanate obtained from an alicyclic diisocyanate. Polyisocyanate compositions have been proposed. Furthermore, Patent Document 3 proposes a polyisocyanate composition having an isocyanurate structure and an allophanate structure obtained from IPDI and a monoalcohol having 10 to 50 carbon atoms. Furthermore, Patent Document 4 discloses a polyisocyanate containing an isocyanurate structure and an allophanate structure obtained by reacting an alicyclic diisocyanate with a diol or triol having a number average molecular weight of 200 to 2000 in the presence of an isocyanurate-forming catalyst. Compositions have been proposed.

JP-A-4-306218 JP 2006-52265 A JP 2008-94860 A Special table 2011-505456 gazette

  However, the conventional polyisocyanate composition is sufficiently soluble in a low-polar organic solvent, and sufficiently satisfies the good curability and drying property of the coating film and high coating film hardness. Can not. In addition, since the coating environment is diversified, this coating film is also required to have a quick drying property at low temperatures in winter and to hardly cause shrinkage of the coating film in the repeated coating process of the coating film.

  Specifically, the polyisocyanate composition described in Patent Document 1 is soluble in a low polar organic solvent by a polyisocyanate composition comprising a mixture of HDI and IPDI and an aliphatic monoalcohol having 6 to 9 carbon atoms. However, there is room for improvement in curability and drying properties when used as a coating film. Moreover, the polyisocyanate composition described in Patent Document 2 is not sufficient in suppressing the shrinkage of the coating film in the overcoating step. Furthermore, the polyisocyanate compositions described in Patent Document 3 and Patent Document 4 are inferior in curability when used as a coating film compared to aliphatic polyisocyanate, and this coating film is brittle.

  Accordingly, the present invention provides a polyisocyanate composition that is soluble in a low-polar organic solvent, exhibits high coating film hardness when formed into a coating film, and is less likely to cause coating film shrinkage in the coating overcoat process. The purpose is to do.

  As a result of repeated studies to solve the above problems, the present inventors have obtained from aliphatic diisocyanate and alicyclic diisocyanate and a specific monoalcohol, and the ratio of the constituent units of the aliphatic diisocyanate is within a specific range. It was found that the polyisocyanate composition can solve the above-mentioned problems of the prior art, and the present invention was made.

That is, the present invention is as follows.
[1] It is obtained from aliphatic diisocyanate and alicyclic diisocyanate and monoalcohol,
The molar ratio of the structural unit of the aliphatic diisocyanate to the structural unit of the alicyclic diisocyanate is 75/25 or more and 95/5 or less,
The monoalcohol is a polyisocyanate composition containing two or more monoalcohols having 3 to 20 carbon atoms.
[2] The polyisocyanate composition according to [1], wherein the monoalcohol includes a monoalcohol having 3 to 6 carbon atoms and a monoalcohol having 7 to 20 carbon atoms.
[3] The polyisocyanate composition according to [1] or [2], wherein the polyisocyanate composition has a molar ratio of allophanate groups to isocyanurate groups of 3/97 or more and 40/60 or less.
[4] The polyisocyanate composition according to any one of [1] to [3], further including a low polarity organic solvent having an aniline point of 10 ° C. or higher and 70 ° C. or lower.
[5] A coating composition comprising the polyisocyanate composition according to any one of [1] to [4] and a polyol.
[6] A coating film formed from the coating composition according to [5].

  According to the polyisocyanate composition of the present invention, it is possible to obtain solubility in a low-polar organic solvent, high coating film hardness when used as a coating film, and a coating film that is difficult to shrink in the coating overcoat process. .

  Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as “the present embodiment”) will be described in detail. The following embodiment is an exemplification for explaining the present invention, and is not intended to limit the present invention to the following embodiment. The present invention can be implemented with various modifications within the scope of the gist. In this specification, the quantity of the specific functional group or structural unit which a composition or a compound has can be represented by "molar ratio." That is, the dimension of the value obtained by dividing the number of specific functional groups or structural units of the composition or compound by the Avogadro number is defined as mole. Thereby, the amount of the specific functional group or structural unit is expressed as a “molar ratio” with respect to the amount of the other specific functional group or structural unit. In addition, the specific functional group or structural unit which a composition has means the specific functional group or structural unit which the compound contained in a composition has.

[Polyisocyanate composition]
The polyisocyanate composition in this embodiment is obtained from aliphatic diisocyanate and alicyclic diisocyanate, and monoalcohol. The molar ratio of the constituent unit of the aliphatic diisocyanate to the constituent unit of the alicyclic diisocyanate is 75/25 or more and 95/5 or less. Furthermore, the monoalcohol contains two or more monoalcohols having 3 to 20 carbon atoms.

<Diisocyanate>
The polyisocyanate composition in this embodiment is derived from an aliphatic diisocyanate and an alicyclic diisocyanate. Therefore, the polyisocyanate composition has a constituent unit of aliphatic diisocyanate and a constituent unit of alicyclic diisocyanate. Hereinafter, aliphatic diisocyanate and alicyclic diisocyanate are collectively referred to as diisocyanate or diisocyanate monomer.

  The aliphatic diisocyanate is not limited to the following as long as it is a diisocyanate having only an isocyanate group and an aliphatic group in the molecule. For example, 1,4-diisocyanatobutane (tetramethylene diisocyanate), 1,5- Diisocyanatopentane (pentamethylene diisocyanate), 1,6-diisocyanatohexane (hereinafter also simply referred to as “HDI”), 1,6-diisocyanato-2,2,4-trimethylhexane (trimethylhexamethylene diisocyanate) 2,6-diisocyanatohexanoic acid methyl ester (lysine diisocyanate). Among these, HDI is preferable because it has excellent weather resistance and toughness when formed into a coating film.

  The alicyclic diisocyanate is not limited to the following as long as it is a diisocyanate having an isocyanate group and a cycloaliphatic group in its molecule. For example, 5-isocyanato-1-isocyanatomethyl-1,3,3-trimethyl Cyclohexane (hereinafter simply referred to as “IPDI”), 1,3-bis (isocyanatomethyl) cyclohexane (hydrogenated xylylene diisocyanate), bis (4-isocyanatocyclohexyl) methane (hydrogenated diphenylmethane diisocyanate), 1, 4-diisocyanatocyclohexane is mentioned. Among these, IPDI, hydrogenated xylylene diisocyanate, and hydrogenated diphenylmethane diisocyanate are preferable because they are easily available industrially, and IPDI is dissolved in an organic solvent having a low polarity (hereinafter simply referred to as “low polarity organic solvent”). It is more preferable because of its superiority.

  The molar ratio of the structural unit of the aliphatic diisocyanate to the structural unit of the alicyclic diisocyanate is 75/25 or more and 95/5 or less, preferably 80/20 or more and 95/5 or less, more preferably 80/20 or more. 93/7 or less. When the molar ratio is 95/5 or less, the drying property is more excellent and the coating film hardness tends to be higher. When the molar ratio is 75/25 or less, the curability is more excellent and the viscosity is low. Tend to be.

The molar ratio of the structural unit of the aliphatic diisocyanate to the structural unit of the alicyclic diisocyanate can be measured by ¹³ C-NMR. An example of the method of measurement by ¹³ C-NMR is shown in the examples described later. In this embodiment, for example, the molar ratio of the structural unit of HDI to the structural unit of IPDI is measured under the conditions described in the examples described later.

<Monoalcohol>
The monoalcohol in the present embodiment includes two or more monoalcohols having 3 to 20 carbon atoms. By containing two or more kinds of monoalcohols, the polyisocyanate composition is made soluble in a low polarity organic solvent, and the shrinkage of the coating film in the overcoating step is prevented.

  The monoalcohol preferably contains a monoalcohol having 3 to 6 carbon atoms and a monoalcohol having 7 to 20 carbon atoms. By using a monoalcohol having 3 or more and 6 or less carbon atoms, the viscosity tends to be low, and the content of isocyanate groups in the polyisocyanate composition (hereinafter also referred to as “isocyanate group content” or “NCO content”). ) Tend to be high enough. Moreover, it exists in the tendency for the solubility with respect to a low polar organic solvent to be more excellent by using C7-C20 monoalcohol. In addition, from the viewpoint of solubility in a low polarity organic solvent, the monoalcohol is preferably branched. The monoalcohol may have an ether group, an ester group or a carbonyl group in the molecule, but is more preferably a monoalcohol consisting only of a saturated hydrocarbon group.

  The monoalcohol having 3 to 6 carbon atoms is not limited to the following, but for example, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, 1-pentanol, 2-pentanol , Isoamyl alcohol, 1-hexanol, and 2-hexanol. Among these, isobutanol and isoamyl alcohol are more preferable because they are branched. On the other hand, the monoalcohol having 7 to 20 carbon atoms is not limited to the following, and examples thereof include 1-heptanol, 1-octanol, 2-ethyl-1-hexanol, 3,3,5-trimethyl-1- Examples include hexanol, lauryl alcohol, tridecanol, pentadecanol, palmityl alcohol, stearyl alcohol, cyclopentanol, cyclohexanol, methylcyclohexanol, and 1,3,5-trimethylcyclohexanol. Among these, 2-ethyl-1-hexanol, 3,3,5-trimethyl-1-hexanol, and 1,3,5-trimethylcyclohexanol are more preferable because they are branched.

  The polyisocyanate composition in this embodiment preferably has an allophanate group and an isocyanurate group.

  When a polyisocyanate composition having an allophanate group and an isocyanurate group is produced from a diisocyanate monomer, a urethanization / allophanate / isocyanurate catalyst is usually used. The catalyst for urethanization, allophanate and isocyanurate is preferably a catalyst having basicity, and is not limited to the following, for example: 1) Hydroalkyl tetraalkylammonium such as tetramethylammonium, tetraethylammonium, benzyltrimethylammonium Oxides and organic weak acid salts of these tetraalkylammonium with acids such as acetic acid and capric acid, 2) hydroxyalkylammonium such as trimethylhydroxypropylammonium, trimethylhydroxyethylammonium, triethylhydroxypropylammonium, triethylhydroxyethylammonium Hydroxides, and organic weak acid salts of these hydroxyalkyl ammoniums with acetic acid, capric acid, etc., 3) acetic acid, 2-e Metal salts of alkyl carboxylic acids such as ruhexanoic acid, capric acid, octylic acid, myristic acid and tin, zinc, lead, zirconium, sodium, potassium, etc. 4) Metal alcoholates such as sodium, potassium, etc. 5) Hexamethyl And aminosilyl group-containing compounds such as disilazane, 6) Mannich bases, and 7) combined use of tertiary amines and epoxy compounds. Among these, the catalyst of said 1), 2), 3) is preferable from a viewpoint of the production | generation efficiency of a target compound. In addition, side reactions, such as the production | generation of a uretdione body, may occur with an aminosilyl group containing compound by the use conditions.

The molar ratio of allophanate groups to isocyanurate groups can be determined by ¹ H-NMR. For example, an example of a method for measuring the molar ratio by ¹ H-NMR with respect to a polyisocyanate composition using HDI and / or an isocyanate prepolymer obtained therefrom as a raw material is shown in the examples described later.

  In the polyisocyanate composition in the present embodiment, the molar ratio of allophanate groups to isocyanurate groups is preferably 3/97 or more and 40/60 or less, more preferably 5/98 or more and 40/60 or less, Preferably they are 5/95 or more and 30/70 or less. When the molar ratio is in the range of 3/97 or more and 40/60 or less, the polyisocyanate composition is excellent in solubility in a low-polar organic solvent, curability and drying properties are sufficiently high, and coating film hardness is sufficiently high. There is a tendency.

  In the production process of the polyisocyanate composition in the present embodiment, a uretdione body may be by-produced. The uretdione body also tends to lower the viscosity of the polyisocyanate composition, but if its content is too high, it may decompose during storage and liberate its monomers. As content of the uretdione body contained in the polyisocyanate composition in this embodiment, it is preferable that it is 10 mass% or less with respect to the total amount (100 mass%) of a polyisocyanate composition, More preferably, it is 8 mass%. Hereinafter, it is more preferably 5% by mass or less.

The content of the uretdione compound can be determined by measuring the ratio of the peak area having a molecular weight of about 336 in gel filtration chromatography (hereinafter referred to as “GPC”) with a differential refractometer. When there is a peak that hinders measurement in the vicinity of a peak with a molecular weight of about 336, a uretdione group of about 1770 cm ⁻¹ is used with a Fourier transform infrared spectrophotometer (hereinafter also referred to as “FT-IR”). And the ratio of the peak height of the allophanate group of about 1720 cm ⁻¹ can also be determined by a method of quantifying using an internal standard. A specific GPC measurement method will be described below. Also about the measured value regarding the molecular weight of a polyisocyanate composition, it can obtain | require by the method similar to the following measuring methods.

  Equipment used: HLC-8120 (trade name, manufactured by Tosoh Corporation), column used: TSK GEL SuperH1000, TSK GEL SuperH2000, TSK GEL SuperH3000 (both trade names, manufactured by Tosoh Corporation), sample concentration: 5 wt / vol% ( For example, 50 mg of a sample is dissolved in 1 mL of THF.), Carrier: tetrahydrofuran (THF), detection method: differential refractometer, flow rate: 0.6 mL / min, column temperature: 30 ° C. Moreover, GPC calibration curves are polystyrenes having a molecular weight of 50,000 to 2050 (manufactured by GL Sciences, trade names, PSS-06 (Mw = 50000), BK13007 (Mp = 20000, Mw / Mn = 1.03), PSS-08. (Mw = 9000), PSS-09 (Mw = 4000), 5040-35125 (Mp = 2050, Mw / Mn = 1.05)) and an HDI-based polyisocyanate composition (Duranate TPA-100, Asahi Kasei Chemicals Corporation) Manufactured isocyanurate trimer to 7mer (isocyanurate trimer molecular weight = 504, isocyanurate pentamer molecular weight = 840, isocyanurate heptamer molecular weight = 1176) and HDI (molecular weight = 168). Prepare as standard.

  Further, in the production process of the polyisocyanate composition in the present embodiment, a urethane body may be by-produced. The urethane body tends to improve the adhesion to the article forming the coating film, but if the content is too large, the solubility in the low-polar organic solvent may decrease. As content of the urethane body contained in the polyisocyanate composition in this embodiment, it is preferable that it is 10 mass% or less with respect to the total amount (100 mass%) of a polyisocyanate composition, More preferably, it is 8 mass%. Hereinafter, it is more preferably 5% by mass or less.

The content of the urethane group can be determined using ¹ H-NMR. By the method of measuring the molar ratio of allophanate groups to isocyanurate groups described in the examples to be described later, the total number of moles of allophanate groups and isocyanurate groups was determined, and further bonded to nitrogen of urethane groups in the vicinity of 4 ppm to 5 ppm. The content of the urethane group can be measured by determining the number of moles of the urethane group from the signal area of the hydrogen atom (1 mole of hydrogen atom relative to 1 mole of the urethane group).

  The NCO content of the polyisocyanate composition in the present embodiment is preferably 10% by mass or more and 30% by mass or less, and more preferably 12% by mass or more and 28% by mass in a state in which substantially no solvent and diisocyanate are contained. % Or less, and more preferably 15% by mass or more and 25% by mass or less. When the NCO content is in the range of 10% by mass or more and 30% by mass or less, the solubility in a low-polar organic solvent is excellent, curability and drying properties are improved, and the coating film hardness tends to be higher. Here, the “state substantially free of solvent and diisocyanate” means that the content of the solvent or diisocyanate in the polyisocyanate composition is less than 1% by mass.

  The viscosity at 25 ° C. of the polyisocyanate composition in the present embodiment is 100 mPa.s in a state of substantially not containing a solvent and a diisocyanate. s to 10,000 mPa.s s or less, more preferably 300 mPa.s. s to 8000 mPa.s s or less, more preferably 500 mPa.s. s to 6000 mPa.s s or less. The viscosity at 25 ° C. is 100 mPa.s. s or more, the curability tends to be sufficiently high, and the viscosity is 10,000 mPa.s. It is in the tendency which is excellent in the solubility to a low polar organic solvent because it is s or less.

  The polyisocyanate composition in this embodiment can contain a low polar organic solvent as needed. It is preferable to include a low-polar organic solvent because the viscosity tends to be low and handling tends to be easy. The content of the low-polar organic solvent is preferably 5% by mass or more and 90% by mass or less, more preferably 7% by mass or more and 80% by mass or less, based on the total amount (100% by mass) of the polyisocyanate composition. More preferably, it is 10 mass% or more and 80 mass% or less. When the content of the low-polar organic solvent is 5% by mass or more, the viscosity tends to be low, and when it is 90% by mass or less, the amount of the volatile organic compound (VOC) tends to be suppressed with a relatively small amount. It is in. The low polarity organic solvent may be used alone or in combination. Moreover, you may mix and use with an aromatic hydrocarbon solvent, an ether solvent, and an ester solvent.

  The low polarity low polarity organic solvent has an aniline point of 10 ° C. or higher and 70 ° C. or lower, preferably 12 ° C. or higher and 65 ° C. or lower, more preferably 15 ° C. or higher and 65 ° C. or lower. It is a solvent. Examples of the organic solvent include, but are not limited to, for example, organic solvents containing an aliphatic or alicyclic hydrocarbon solvent as a main component, and aromatic hydrocarbon solvents and ester solvents. And ether solvents. Among these, the low polarity organic solvent is not limited to the following, but, for example, methylcyclohexane (aniline point 40 ° C.), ethylcyclohexane (aniline point 44 ° C.), mineral spirit (mineral terpene, aniline point 56 ° C.). Turpentine oil (aniline point 20 ° C.); generally marketed as petroleum-based hydrocarbons, and trade names include HAWS (trade name, manufactured by Shell Chemicals Japan, aniline point 17 ° C.), Essonaphtha No. 6 (trade name, manufactured by ExxonMobil Chemical, aniline point 43 ° C.), LAWS (trade name, manufactured by Shell Chemicals Japan, aniline point 44 ° C.), pegasol 3040 (trade name, manufactured by TonenGeneral Sekiyu, aniline point 55 ° C.), A Solvent (trade name, manufactured by JX Nippon Oil & Energy, aniline point 45 ° C), Clensol (trade name, manufactured by JX Nippon Oil & Energy, aniline point 64 ° C), mineral spirit A (trade name, manufactured by JX Nippon Oil & Energy, Aniline point 43 ° C.), Hyalom 2S (trade name, manufactured by JX Nippon Oil & Energy, aniline point 44 ° C.); at least one of these low-polar organic solvents and, if necessary, aromatic hydrocarbon solvent, ester type What mixed the solvent and the ether solvent is mentioned. The aniline point is measured according to the aniline point test method described in JIS K 2256.

  When the polyisocyanate composition in the present embodiment contains a low polar organic solvent, the low polarity organic solvent having an aniline point of 10 ° C. or higher and 70 ° C. or lower, preferably 12 ° C. or higher and 65 ° C. or lower, more preferably 15 ° C. or higher and 65 ° C. or lower. Dissolve in solvent. In the present embodiment, dissolution refers to completely uniform and transparent compatibility when 100 parts by mass of a low-polar organic solvent is mixed with 100 parts by mass of a polyisocyanate composition containing no solvent and diisocyanate at 20 ° C. To do.

  The polyisocyanate composition in the present embodiment can be used by mixing with a silicate compound. By mixing with a silicate compound, the stain resistance of the coating film obtained from the coating composition described later tends to be improved.

[Coating composition]
The coating composition in this embodiment contains the polyisocyanate composition mentioned above and a polyol. Examples of the polyol include, but are not limited to, for example, aliphatic hydrocarbon polyols, fluorine-containing polyols, silicon-containing polyols, polyether polyols, polyester polyols, polycarbonate polyols, epoxy resins, One kind of acrylic polyols and alkyd polyols and mixtures thereof are mentioned. Among these, a polyol that is a main agent dissolved in a low-polar organic solvent, or a polyol that is a so-called NAD-based main agent that is dispersed is preferable because it tends to hardly damage the old coating film during the repainting operation. . In addition, if the aniline point of the low polarity organic solvent in which the polyol is dissolved is 10 ° C. or higher and 70 ° C. or lower, it is more preferable because the old coating film tends to be more difficult to attack. If it is a polar organic solvent, since the influence on an environment tends to become small, it is more preferable. Furthermore, among the polyols dissolved or dispersed in the low polar organic solvent, acrylic polyols, fluorine-containing polyols, and silicon-containing polyols are more preferred because they tend to have excellent weather resistance. Furthermore, fluorine-containing polyols are more preferred because they tend to have better weather resistance. The polyol which is the main agent may be used alone or in combination.

  The hydroxyl value of the polyol is preferably 1 mgKOH / g or more and 300 mgKOH / g or less, more preferably 4 mgKOH / g or more and 250 mgKOH / g or less, and further preferably 8 mgKOH / g or more and 200 mgKOH / g or less. When the hydroxyl value is 1 mgKOH / g or more, the curability and drying property tend to be sufficiently high, and when the hydroxyl value is 300 mgKOH / g or less, the flexibility of the coating film tends to be sufficient. .

  Polyols can be produced by a known technique. Hereinafter, typical methods for producing acrylic polyols, polyester polyols, and polyether polyols will be described.

  The method for producing the acrylic polyol is not limited to the following, but for example, a method obtained by polymerizing a polymerizable monomer having one or more active hydrogens in one molecule alone, a polymerizable monomer, and Examples thereof include a method obtained by copolymerizing with another copolymerizable monomer. The polymerizable monomer having one or more active hydrogens in one molecule is not limited to the following, but examples thereof include: 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxy acrylate Acrylic acid esters having active hydrogen such as butyl; methacrylate-2-hydroxyethyl, methacrylate-2-hydroxypropyl, methacrylate-2-hydroxybutyl, methacrylate-3-hydroxypropyl, methacrylate-4-hydroxy Methacrylic acid esters having active hydrogen such as butyl; (Meth) acrylic acid esters having polyvalent active hydrogen such as acrylic monoester and methacrylic monoester of triol such as glycerin and trimethylolpropane; polyethylene glycol, polypropylene Glycol Monoethers of polyether polyols such as polybutylene glycol and the above (meth) acrylic acid esters having active hydrogen; glycidyl (meth) acrylate and acetic acid, propionic acid, p-tert-butylbenzoic acid, etc. Adduct with acid; selected from the group of adducts obtained by ring-opening polymerization of lactones such as ε-caprolactam and γ-valerolactone to active hydrogen of (meth) acrylic acid esters having active hydrogen as described above These may be used alone or as a mixture. Further, other monomers copolymerizable with these are not limited to the following, but for example, methyl acrylate, ethyl acrylate, isopropyl acrylate, acrylate-n-butyl, acrylate-2-ethylhexyl, etc. Acrylic acid esters; methacrylic acid such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, -n-butyl methacrylate, isobutyl methacrylate, methacrylic acid -n-hexyl, cyclohexyl methacrylate, lauryl methacrylate, glycidyl methacrylate Esters; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid and itaconic acid; unsaturated amides such as acrylamide, N-methylolacrylamide and diacetoneacrylamide; vinyltrimethoxysilane, vinylmethyl Vinyl monomers having hydrolyzable silyl groups such as methoxysilane and γ- (meth) acrylopropyltrimethoxysilane; other polymerizable monomers such as styrene, vinyltoluene, vinyl acetate, acrylonitrile and dibutyl fumarate The single or mixture chosen from these is mentioned. As a copolymerization method, for example, the above (polymerizable) monomer can be obtained by solution polymerization in the presence of a known radical polymerization initiator such as a peroxide or an azo compound.

  The production method of the polyester polyol is not limited to the following, but for example, succinic acid, adipic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, 1,4-cyclohexanedicarboxylic acid, etc. One or a mixture of dibasic acids and ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, trimethylpentanediol, 1,2-, 1,3- and 1 , 4-cyclohexanediol, trimethylolpropane, glycerin, pentaerythritol, 2-methylolpropanediol, ethoxylated trimethylolpropane, or other polyhydric alcohols can be obtained by performing a known condensation reaction. The condensation reaction can be performed, for example, by combining the above components and heating at about 160 ° C to about 220 ° C. For example, polycaprolactones obtained by ring-opening polymerization of lactones such as ε-caprolactone using polyhydric alcohols can also be used as polyester polyols.

  The method for producing the polyether polyol is not limited to the following, for example, polyhydric alcohol, polyhydric phenol, polyamine, alkanolamine; ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1, Dihydric alcohols such as 4-butanediol, 1,6-hexanediol, and bisphenol A; Trihydric alcohols such as glycerin and trimethylolpropane; and hydroxylation of lithium, sodium, potassium, etc., alone or in a mixture of diamines such as ethylenediamine. Strongly basic catalysts such as alcoholates and alkylamines; metalloporphyrins, complex metal cyanide complexes, complexes of metals with chelating agents of tridentate or higher, complex metal complexes such as hexacyanocobaltate zinc complex And use of ethylene oxide, propylene oxide, butylene oxide, cyclohexene oxide, and a method obtained by adding a single or a mixture of alkylene oxide such as styrene oxide.

  In the coating composition in the present embodiment, the molar ratio of the isocyanate group contained in the polyisocyanate composition to the hydroxyl group contained in the polyol is preferably 1/10 or more and 10/1 or less, more preferably 1/5 or more. 5/1 or less, more preferably 1/3 or more and 3/1 or less. When the molar ratio of the isocyanate group to the hydroxyl group is in the range of 1/10 or more and 10/1 or less, the curability and drying property tend to be sufficiently high.

  In the polyisocyanate composition and the coating composition in the present embodiment, a silane cup for improving the adhesion of colored pigments, dyes, and coatings is used in a range that does not impair the effects of the present embodiment, depending on the purpose and application. Technical fields such as ring agents, ultraviolet absorbers, light stabilizers, matting agents, coating surface hydrophilizing agents, curing accelerators, drying improvers, leveling agents, antioxidants, plasticizers, surfactants, etc. It is also possible to use a mixture of various additives used in the above.

  Color pigments and dyes are not limited to the following, but include, for example, inorganic pigments such as carbon black and titanium oxide, which have good weather resistance, phthalocyanine blue, phthalocyanine green, quinacridone red, indanthrene orange, isoindolinone yellow And organic pigments and dyes.

  Examples of the silane coupling agent include, but are not limited to, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, Ureidopropyltriethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3 -Glycidoxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, methyltriethoxysilane, methyltrimethoxysilane.

  Although not limited to the following as an ultraviolet absorber, For example, a benzophenone type, a benzotriazole type, a triazine type, and a cyanoacrylate type ultraviolet absorber are mentioned.

  Examples of the light stabilizer include, but are not limited to, hindered amine light stabilizers, and commercially available products include ADK STAB LA62, ADK STAB LA67 (trade name, manufactured by Adeka Argas Chemical Co., Ltd.), Tinuvin 292, and the like. Tinuvin 144, Tinuvin 123, Tinuvin 440 (trade name, manufactured by Ciba Specialty Chemicals), Sanol LS765 (trade name, manufactured by Sankyo Lifetech Co., Ltd.).

  The matting agent is not limited to the following, but includes, for example, ultra fine powdered synthetic silica. When the matting agent is used, an elegant semi-gloss and matte finish coating film tends to be formed.

  Although it is not limited to the following as a coating-film surface hydrophilic agent, For example, a silicate compound is preferable. When a coating film composition contains a silicate compound, when a coating film is produced using the coating composition, the surface of the coating film becomes hydrophilic and exhibits rain-stain stain resistance. Since the silicate compound reacts with the hydroxyl group, it is preferably added to the polyisocyanate composition when mixed beforehand. Or when mixing a polyol and a polyisocyanate composition, you may mix simultaneously. Examples of the silicate compound include, but are not limited to, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, tetraisobutoxysilane, and tetra-tert. -Butoxysilane, dimethoxydiethoxysilane, tetraphenoxysilane, and condensates thereof. Among these, the condensate of tetramethoxysilane and the condensate of tetraethoxysilane are more preferable because the surface of the coating tends to become hydrophilic when a coating is prepared.

  Examples of the catalyst for accelerating the curing include, but are not limited to, for example, dialkyltin dicarboxylates such as dibutyltin dilaurate, dioctyltin dilaurate, and dibutyltin diacetate; tin oxide compounds such as dibutyltin oxide; tin 2-ethylhexanoate Metal carboxylates such as zinc 2-ethylhexanoate and cobalt salts; triethylamine, pyridine, methylpyridine, benzyldimethylamine, N, N-dimethylcyclohexylamine, N-methylpiperidine, pentamethyldiethylenetriamine, N, N'- And tertiary amines such as endoethylene piperazine and N, N′-dimethylpiperazine.

  Examples of the drying property improver include, but are not limited to, CAB (cellulose acetate butrate) and NC (nitrocellulose).

  The coating composition in the present embodiment is preferably a two-component paint used by mixing a polyol and a polyisocyanate composition at the site of painting, and additives may be mixed as necessary. it can. The order of mixing is not limited to the following, but for example, a method of mixing a polyisocyanate composition as a curing agent at a coating site with a polyol which is a main agent in which additives are mixed in advance, at a coating site. A method of mixing a polyol, which is a main agent, and a polyisocyanate composition as a curing agent, and then mixing an additive, and a curing agent in which an additive is previously mixed with a polyol, which is a main agent in which additives are mixed in advance, at a coating site. And a method of mixing the polyisocyanate composition.

  The method of coating using the coating composition in the present embodiment is not limited to the following, but for example, any method such as spray coating, air spray coating, brush coating, dipping method, roll coater, flow coater, etc. Is mentioned.

[Coating]
The coating film in this embodiment is formed by the coating composition of this embodiment. As a method for forming the coating film, it is preferable to obtain the coating film by curing the coating composition of the present embodiment. Since it is comprised in this way, the coating film of this embodiment is a coating film with high coating-film hardness, and a coating-film shrinkage does not generate | occur | produce easily in the overcoating process. The objects to be coated are not limited to the following, but examples include metal, wood, glass, stone, ceramic materials, concrete, hard and flexible plastics, textile products, leather products, and paper. Can be mentioned. In some cases, the article to be coated may be provided with a normal primer before being coated with the coating composition.

  Hereinafter, the present embodiment will be described in more detail with reference to specific examples and comparative examples. However, the present embodiment is not limited to these examples and comparative examples unless they exceed the gist of the present embodiment. Unless otherwise specified, “parts” and “%” in Examples and Comparative Examples are based on mass standards. Various physical properties and evaluations in Examples and Comparative Examples were measured and evaluated as follows.

(Physical property 1) Change in refractive index Using a refractometer (trade name: RA-520, manufactured by Kyoto Electronics Industry Co., Ltd.) as a sample, the reaction liquid in Synthesis Examples 1 to 9 described later, the refractive index of 30 ° C. Changes were measured.

(Physical property 2) Isocyanate group content (NCO content)
The polyisocyanate composition was used as a sample, and the isocyanate group content was measured according to the method described in JIS K7301-1995 (Test method for tolylene diisocyanate type prepolymer for thermosetting urethane elastomer). Below, the more specific measuring method of isocyanate group content rate is shown.
(1) 1 g of a sample was collected in a 200 mL Erlenmeyer flask, and 20 mL of toluene was added to the flask to dissolve the sample.
(2) Thereafter, 20 mL of a 2.0 N di-n-butylamine / toluene solution was added to the flask and allowed to stand for 15 minutes.
(3) 70 mL of 2-propanol was added to the flask and dissolved to obtain a solution.
(4) The solution obtained in (3) above was titrated with 1.0 N hydrochloric acid to determine the sample titer.
(5) Even when the sample was not added, the measurement was performed in the same manner as in the above (1) to (3), and the blank titer was determined.
The isocyanate group content was calculated by the following calculation method from the sample titration and blank titration determined above.
Isocyanate group content (mass%) = (blank titration-sample titration) × 42 / [sample mass (g) × 1,000] × 100%.

(Physical Property 3) Viscosity Using the polyisocyanate composition as a sample, the viscosity at 25 ° C. was measured using an E-type viscometer (trade name: RE-85R manufactured by Toki Sangyo Co., Ltd.). A standard rotor (1 ° 34 ′ × R24) was used, and the rotation speed was set as follows.
100r. p. m. (If less than 128 mPa.s)
50r. p. m. (In the case of 128 mPa.s to 256 mPa.s)
20r. p. m. (In the case of 256 mPa.s to 640 mPa.s)
10r. p. m. (In the case of 640 mPa.s to 1280 mPa.s)
5r. p. m. (In the case of 1280 mPa.s to 2560 mPa.s)
2.5r. p. m. (From 2560 mPa.s to 5120 mPa.s)
1.0r. p. m. (In the case of 5120 mPa.s to 10240 mPa.s)
0.5r. p. m. (In the case of 10240 mPa.s to 20480 mPa.s)

(Physical property 4) Molar ratio of constituent unit of aliphatic diisocyanate to constituent unit of alicyclic diisocyanate
Using the measurement method of ¹³ C-NMR, the measurement was performed as follows. The polyisocyanate composition was dissolved in deuterium chloroform at a concentration of 20% by mass (after dissolution, 0.03% by mass tetramethylsilane was added to the polyisocyanate composition). The chemical shift standard was 0 ppm for the carbon signal of the methyl group of tetramethylsilane. Measurements were made in a quantitative mode called the NNE method. Under these measurement conditions, carbon signals of two types of methyl groups emitted from the cyclohexane ring of the structural unit of IPDI were observed in the vicinity of 31.5 to 32.5 ppm and in the vicinity of 27.0 to 28.0 ppm. The carbons at the 2-5 positions of the hexamethylene chain of the structural unit of HDI are around 26.0-27.0 ppm, 27.0-28.0 ppm, 29.0-30.0 ppm, and 31.0-31. It was observed around 5 ppm. Therefore, the molar ratio (HDI / IPDI) of the HDI structural unit to the IPDI structural unit was determined from these signals as follows.
1. The area of each signal was converted by setting the area of the signal derived from the structural unit of IPDI in the vicinity of 31.5 to 32.5 ppm to 1.0.
2. HDI / IPDI was determined by the following formula.
HDI / IPDI = ((Area of signal around 26.0-27.0 ppm + Area of signal around 27.0-28.0 ppm + Area of signal around 29.0-30.0 ppm + Area around 31.0-31.5 ppm Signal area) / (area corresponding to the signal of the carbon of one of the methyl groups coming out of the cyclohexane ring of the IPDI structural unit observed around 27.0-28.0 ppm) / 4

(Property 5) Molar ratio of allophanate group to isocyanurate group
It measured as follows using the measuring method of < ¹ > H-NMR. The polyisocyanate composition was dissolved in deuterium chloroform at a concentration of 10% by mass (0.03% by mass tetramethylsilane was added to the polyisocyanate composition after dissolution). As a chemical shift standard, a hydrogen signal of tetramethylsilane was set to 0 ppm. Measured by ¹ H-NMR, signal of hydrogen atom bonded to nitrogen of allophanate group at around 8.5 ppm (1 mole of hydrogen atom per mole of allophanate group) and isocyanurate group at around 3.85 ppm The signal area ratio of the hydrogen atom of the methylene group adjacent to (6 mole of hydrogen atom per mole of isocyanurate group) was measured. The molar ratio of allophanate groups to isocyanurate groups (allophanate groups / isocyanurate groups) was determined by the following calculation formula.
Allophanate group / isocyanurate group = (signal area around 8.5 ppm) / (signal area around 3.85 ppm / 6)

(Evaluation 1) Solubility in low-polar organic solvent Solubility in low-polar organic solvent was gradually added to the polyisocyanate composition while stirring HAWS to the polyisocyanate composition and began to become cloudy. The mass at the time was measured and determined by the following formula. The case where the solubility in a low-polar organic solvent was 1000% or more was evaluated as “◯”, the case where it was 800% or more and less than 1000% was evaluated as “Δ”, and the case where it was less than 800% was evaluated as “X”.
Solubility in low-polar organic solvent (%) = ((mass (g) of low-polar organic solvent at the time of starting to become cloudy)) / (mass (g) of polyisocyanate compound) × 100

(Evaluation 2) Gel fraction: curability The curability was evaluated by measuring the gel fraction at the initial stage of curing of the coating film. The coating composition was applied to a polypropylene plate using a bar coater so that the film thickness was about 50 microns, and then the gel fraction when dried at 23 ° C. for 2 days was measured. The gel fraction is an index of curability and is obtained from the mass of a coating film obtained by immersing about 0.1 g of a coating film in acetone at 23 ° C. for 24 hours, taking out the coating film, and drying at 80 ° C. for 1 hour. It was. The case where the gel fraction was 80% or more was evaluated as “◯”, the case where it was 70% or more and less than 80% was evaluated as “Δ”, and the case where it was less than 70% was evaluated as “×”. In addition, since the polyisocyanate composition evaluated as "x" by (evaluation 1) did not produce a coating film using this, it was set as "not evaluated".

(Evaluation 3) Gauze drying property The gauze drying property of the coating film was measured as an indicator of drying property. The coating composition was applied to a glass plate with a bar coater so that the film thickness was about 50 microns, and then dried at 23 ° C. for 4 hours, and then dried. Five sheets of Japanese pharmacopoeia gauze were layered on the coating film, and 100 g of weight was placed on it for 60 seconds. Thereafter, the weight and gauze are removed, and the gauze trace remaining on the coating film is observed. The case where there was no trace was evaluated as “◯”, the case where the trace remained slightly was evaluated as “Δ”, and the case where the trace remained clearly was evaluated as “X”. In addition, since the polyisocyanate composition evaluated as "x" by (evaluation 1) did not produce a coating film using this, it was set as "not evaluated".

(Evaluation 4) Pencil hardness Based on JIS K 5600-5-4: Scratch hardness (pencil method), the test was implemented with respect to the coating film. After applying the coating composition using a bar coater so that the film thickness was about 50 microns on the glass plate, the pencil hardness was measured when dried at 23 ° C. for 7 days. The case where it is F or more is “◎”, the case where it is HB is “◯”, the case where it is B is “Δ”, and the case where it is 2B or less is “×”. In addition, since the polyisocyanate composition evaluated as "x" by (evaluation 1) did not produce a coating film using this, it was set as "not evaluated".

(Evaluation 5) Shrinkage of coating film A condition where the coating composition was applied as the first layer of the coating film using a bar coater so that the film thickness was about 50 microns on a glass plate, and then dried at 23 ° C. for 8 hours. The appearance of the coating film was observed when the second layer was similarly overcoated with the coating composition having the same formulation. The case where there was no shrinkage of the coating film was designated as “O”, and the case where there was shrinkage of the coating film was designated as “X”. In addition, since the polyisocyanate composition evaluated as "x" by (evaluation 1) did not produce a coating film using this, it was set as "not evaluated".

[Synthesis Example 1]
The inside of a four-necked flask equipped with a stirrer, a thermometer, and a condenser was replaced with nitrogen, and 700 g of HDI, 300 g of IPDI, 0.95 g of isobutanol, and 20 g of 2-ethyl-1-hexanol were charged. The temperature inside the reactor was raised with stirring, and when the temperature reached 80 ° C., 0.05 g of potassium caprate was added as a catalyst to carry out urethanization, allophanate and isocyanurate reactions, and the refractive index of the reaction solution changed. When 0.0125 was reached, 0.11 g of 85% aqueous phosphoric acid solution was added to stop the reaction. Thereafter, the temperature of the reaction solution was raised to 90 ° C. and maintained at 90 ° C. for 1 hour to completely deactivate the catalyst. After the reaction solution was filtered, unreacted HDI and IPDI were removed using a falling film distillation apparatus. The resulting polyisocyanate composition is a transparent liquid, having an NCO content of 23.6% by mass and a viscosity of 3100 mPa.s. s. As a result of measuring NMR, the molar ratio of HDI to IPDI was 81.4 / 18.6, and the molar ratio of allophanate groups to isocyanurate groups was 22.6 / 77.4. The obtained polyisocyanate composition is designated as polyisocyanate composition P1 (also simply referred to as “P1”).

[Synthesis Example 2]
In the same apparatus as in Example 1, 700 g of HDI and 300 g of IPDI, 0.95 g of isobutanol and 10 g of lauryl alcohol were charged. The temperature inside the reactor was raised with stirring, and when 90 ° C was reached, 0.05 g of N, N, N-trimethyl-N-benzylammonium hydroxide was added as a catalyst to urethanize, allophanate and isocyanurate. When the refractive index change of the reaction solution reached 0.011, 0.14 g of 85% aqueous phosphoric acid solution was added to stop the reaction. Thereafter, the reaction solution was kept at 90 ° C. for 1 hour to completely deactivate the catalyst. After the reaction solution was filtered, unreacted HDI and IPDI were removed using a falling film distillation apparatus. The obtained polyisocyanate composition was a transparent liquid, had an NCO content of 22.5% by mass and a viscosity of 1800 mPa.s. s. As a result of measuring NMR, the molar ratio of HDI to IPDI was 81.4 / 18.6, and the molar ratio of allophanate groups to isocyanurate groups was 9.8 / 90.2. The obtained polyisocyanate composition is designated as polyisocyanate composition P2 (also simply referred to as “P2”).

[Synthesis Example 3]
In the same apparatus as in Example 1, 1000 g of HDI, 0.9 g of isobutanol and 30 g of 2-ethyl-1-hexanol were charged, and the urethanization reaction was performed at 80 ° C. for 1 hour with stirring. Thereafter, 0.05 g of tetramethylammonium capryate was added as a catalyst to carry out allophanate and isocyanurate reactions. When the refractive index change of the reaction solution reached 0.011, 0.09 g of 85% aqueous phosphoric acid solution was added. In addition, the reaction was stopped. Thereafter, the temperature of the reaction solution was raised to 90 ° C. and maintained at 90 ° C. for 1 hour to completely deactivate the catalyst. After filtering the reaction solution, 90 g of the polyisocyanate composition from which unreacted HDI was removed using a flow-down type thin-film distillation apparatus, and commercially available IPDI isocyanurate type polyisocyanate (trade name: T1890 / 100 Degussa Japan Co., Ltd.) Manufactured, NCO content of 17.2% by mass) was melted by heating at 120 ° C. for 2 hours. The obtained polyisocyanate composition was a transparent liquid, had an NCO content of 20.3% by mass and a viscosity of 1100 mPa.s. s. As a result of measuring NMR, the molar ratio of HDI to IPDI was 91.5 / 8.5, and the molar ratio of allophanate groups to isocyanurate groups was 29.1 / 70.9. The obtained polyisocyanate composition is designated as polyisocyanate composition P3 (also simply referred to as “P3”).

[Synthesis Example 4]
In the same apparatus as in Example 1, 1000 g of HDI, 0.9 g of isobutanol and 30 g of 2-ethyl-1-hexanol were charged, and the urethanization reaction was performed at 80 ° C. for 1 hour with stirring. Thereafter, 0.05 g of tetramethylammonium capriate was added as a catalyst, and allophanatization and isocyanuration reactions were performed. When the change in the refractive index of the reaction solution reached 0.011, 0.09 g of 85% aqueous phosphoric acid solution was added. In addition, the reaction was stopped. Thereafter, the temperature of the reaction solution was raised to 90 ° C. and maintained at 90 ° C. for 1 hour to completely deactivate the catalyst. After filtering the reaction solution, a commercially available IPDI isocyanurate-type polyisocyanate (trade name: T1890 / 100 Degussa Japan Co., Ltd.) is used for 80 g of the polyisocyanate composition from which unreacted HDI has been removed using a falling film distillation apparatus. 20 g of an NCO content of 17.2% by mass) was melted by heating at 120 ° C. for 2 hours. The resulting polyisocyanate composition is a transparent liquid, having an NCO content of 19.9% by mass and a viscosity of 3700 mPa.s. s. As a result of measuring NMR, the molar ratio of HDI to IPDI was 82.8 / 17.2, and the molar ratio of allophanate groups to isocyanurate groups was 25.8 / 74.2. The obtained polyisocyanate composition is designated as polyisocyanate composition P4 (also simply referred to as “P4”).

[Synthesis Example 5]
In the same apparatus as in Example 1, 1000 g of HDI, 0.9 g of isobutanol and 30 g of 2-ethyl-1-hexanol were charged, and the urethanization reaction was performed at 80 ° C. for 1 hour with stirring. Thereafter, 0.05 g of tetramethylammonium capriate was added as a catalyst, and allophanatization and isocyanuration reactions were performed. When the change in the refractive index of the reaction solution reached 0.011, 0.09 g of 85% aqueous phosphoric acid solution was added. In addition, the reaction was stopped. Thereafter, the temperature of the reaction solution was raised to 90 ° C. and maintained at 90 ° C. for 1 hour to completely deactivate the catalyst. After the reaction solution was filtered, unreacted HDI was removed using a falling film distillation apparatus. The resulting polyisocyanate composition is a transparent liquid, having an NCO content of 20.6% by mass and a viscosity of 500 mPa.s. s. As a result of NMR measurement, the molar ratio of HDI to IPDI was 100/0, and the molar ratio of allophanate groups to isocyanurate groups was 32.3 / 67.7. The obtained polyisocyanate composition is designated as polyisocyanate composition P5 (also simply referred to as “P5”).

[Synthesis Example 6]
In the same apparatus as in Example 1, 1000 g of HDI, 0.9 g of isobutanol and 100 g of 2-ethyl-1-hexanol were charged, the temperature in the reactor was raised with stirring, and when the temperature reached 80 ° C., capric acid was used as a catalyst. Add 0.05g of potassium, perform urethanization, allophanatization and isocyanurate reaction. When the change in the refractive index of the reaction solution becomes 0.014, add 0.11g of 85% aqueous solution of phosphoric acid to react. Stopped. Thereafter, the temperature of the reaction solution was raised to 90 ° C. and maintained at 90 ° C. for 1 hour to completely deactivate the catalyst. After the reaction solution was filtered, unreacted HDI was removed using a falling film distillation apparatus. The resulting polyisocyanate composition is a transparent liquid, having an NCO content of 17.6% by mass and a viscosity of 420 mPa.s. s. As a result of NMR measurement, the molar ratio of HDI to IPDI was 100/0, and the molar ratio of allophanate groups to isocyanurate groups was 72.7 / 27.3. The obtained polyisocyanate composition is designated as polyisocyanate composition P6 (also simply referred to as “P6”).

[Synthesis Example 7]
In the same apparatus as in Example 1, 1000 g of HDI and 0.9 g of isobutanol were charged. The temperature inside the reactor was raised with stirring, and when it reached 70 ° C., 0.05 g of potassium caprate was added as a catalyst to carry out urethanization, allophanate and isocyanurate reactions, and the refractive index of the reaction solution changed. When 0.022 was reached, 0.11 g of 85% aqueous phosphoric acid solution was added to stop the reaction. Thereafter, the temperature of the reaction solution was raised to 90 ° C. and maintained at 90 ° C. for 1 hour to completely deactivate the catalyst. After the reaction solution was filtered, unreacted HDI was removed using a falling film distillation apparatus. The obtained polyisocyanate composition was a transparent liquid, had an NCO content of 23.1% by mass and a viscosity of 1400 mPa.s. s. As a result of measuring NMR, the molar ratio of HDI to IPDI was 100/0, and the molar ratio of allophanate groups to isocyanurate groups was 2.3 / 97.7. The obtained polyisocyanate composition is designated as polyisocyanate composition P7 (also simply referred to as “P7”).

[Synthesis Example 8]
In the same apparatus as in Example 1, 1000 g of HDI, 0.9 g of isobutanol and 30 g of 2-ethyl-1-hexanol were charged, and the urethanization reaction was performed at 80 ° C. for 1 hour with stirring. Thereafter, 0.05 g of tetramethylammonium capriate was added as a catalyst, and allophanatization and isocyanuration reactions were performed. When the change in the refractive index of the reaction solution reached 0.011, 0.09 g of 85% aqueous phosphoric acid solution was added. In addition, the reaction was stopped. Thereafter, the temperature of the reaction solution was raised to 90 ° C. and maintained at 90 ° C. for 1 hour to completely deactivate the catalyst. After filtering the reaction solution, a commercially available IPDI isocyanurate-type polyisocyanate (trade name: T1890 / 100 Degussa Japan Co., Ltd.) is used for 70 g of the polyisocyanate composition from which unreacted HDI has been removed using a falling film distillation apparatus. Manufactured, NCO content of 17.2% by mass) was melted by heating at 120 ° C. for 2 hours. The resulting polyisocyanate composition is a transparent liquid, having an NCO content of 19.6% by mass and a viscosity of 4900 mPa.s. s. As a result of measuring NMR, the molar ratio of HDI to IPDI was 73.7 / 26.3, and the molar ratio of allophanate groups to isocyanurate groups was 22.6 / 77.4. The obtained polyisocyanate composition is designated as polyisocyanate composition P8 (also simply referred to as “P8”).

[Synthesis Example 9]
In the same apparatus as in Example 1, 1000 g of HDI, 9 g of isobutanol and 75 g of 12-hydroxystearyl alcohol (trade name: Sobamol 912, manufactured by Cognis Japan Co., Ltd.) were charged, and the reactor internal temperature was stirred at 90 ° C. for 1 hour, 130 The temperature was raised to 0 ° C. and the urethanization reaction was carried out for another hour. Thereafter, 0.65 g of a 20% solid spirit solution of zirconyl 2-ethylhexanoate as a catalyst was added to perform allophanate and isocyanurate reactions, and when the refractive index change of the reaction solution reached 0.0035. 0.37 g of JP-508 (trade name, manufactured by Johoku Chemical Industry Co., Ltd., octyl phosphate) was added to stop the reaction. After filtering the reaction solution, a commercially available IPDI isocyanurate-type polyisocyanate (trade name: T1890 / 100 Degussa Japan Co., Ltd.) is used for 80 g of the polyisocyanate composition from which unreacted HDI has been removed using a falling film distillation apparatus. 20 g of an NCO content of 17.2% by mass) was melted by heating at 120 ° C. for 2 hours. The resulting polyisocyanate composition is a transparent liquid, having an NCO content of 16.9% by mass and a viscosity of 5300 mPa.s. s. As a result of NMR measurement, the molar ratio of HDI to IPDI was 79.0 / 21.0, and the molar ratio of allophanate groups to isocyanurate groups was 77.6 / 22.4. The obtained polyisocyanate composition is designated as polyisocyanate composition P9 (also simply referred to as “P9”).

[Examples 1 to 4, Comparative Examples 1 to 5]
About each said polyisocyanate composition P1-P9, the solubility (evaluation 1) to a low polar organic solvent was evaluated. Table 2 shows the results.

  Further, non-aqueous dispersion type acrylic polyol (trade name: ACRYDIC A-875-55, manufactured by DIC Corporation, hydroxyl value: 40.4 mg KOH / g (solid content), heating residue: 55.2% by mass, Using the two-component polyurethane paint in which each of the above polyisocyanate compositions P1 to P9 (other than P7) is mixed at an NCO / OH ratio: 1.0 and blended with HAWS to a paint solid content of 45% by mass. A polyurethane coating was prepared on a polypropylene plate and a glass plate, and (Evaluation 2) Gel fraction, (Evaluation 3) Gauze drying property, (Evaluation 4) Pencil hardness, (Evaluation 5) The shrinkage of the coating film was evaluated, and the results are shown in Table 2. Note that P7 of the polyisocyanate composition did not produce a coating film because the result of (Evaluation 1) was “x”. Two-component poly For producing a polyurethane coating with urethane paint, (Evaluation 2) to (Evaluation 5) describes the details of the conditions such as film thickness.

  From the results described above, it can be seen that the polyisocyanate composition in this embodiment is soluble in a low-polar organic solvent. Moreover, it turns out by using the coating composition containing the polyisocyanate composition in this embodiment that sclerosis | hardenability and drying property are favorable, coating-film hardness is high, and a coating-film shrinkage does not generate | occur | produce easily in a recoating process.

  The polyisocyanate composition and paint composition according to the present invention can be suitably used for applications such as paints, inks, adhesives, casting materials, elastomers, foams, and raw materials for plastic materials. Among these, it can be suitably used for applications such as architectural paints, heavy anticorrosion paints, automobile paints, home appliance paints, information equipment paints such as personal computers and mobile phones. It can be used more suitably for applications such as paint.

Claims (6)

Obtained from aliphatic and alicyclic diisocyanates and monoalcohols,
The molar ratio of the structural unit of the aliphatic diisocyanate to the structural unit of the alicyclic diisocyanate is 75/25 or more and 95/5 or less,
The monoalcohol is a polyisocyanate composition containing two or more monoalcohols having 3 to 20 carbon atoms.   The polyisocyanate composition according to claim 1, wherein the monoalcohol includes a monoalcohol having 3 to 6 carbon atoms and a monoalcohol having 7 to 20 carbon atoms.   The polyisocyanate composition according to claim 1 or 2, wherein the polyisocyanate composition has a molar ratio of allophanate groups to isocyanurate groups of 3/97 or more and 40/60 or less.   The polyisocyanate composition according to any one of claims 1 to 3, further comprising a low-polar organic solvent having an aniline point of 10 ° C or higher and 70 ° C or lower.   The coating composition containing the polyisocyanate composition of any one of Claims 1-4, and a polyol.   A coating film formed from the coating composition according to claim 5.