JPH11171966A - Polyisocyanate composition, method for producing the same, and curing agent for paint using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyisocyanate composition having both flexibility and drying property, a method for producing the same, and a curing agent for paints using the same. SOLUTION: The weight ratio of the hydrogenated xylylene diisocyanate-modified polyisocyanate (A) having at least isocyanurate group and the hexamethylene diisocyanate-modified polyisocyanate (B) having at least isocyanurate group is (A): (B) = 1:
99-65: 35 and a viscosity of 10-50,0.
The problem is solved by using a polyisocyanate composition having a temperature of 00 cSt / 25 ° C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyisocyanate composition, a method for producing the same, and a curing agent for paints using the same. More specifically, a polyisocyanate composition containing a modified polyisocyanate of hydrogenated xylylene diisocyanate having at least an isocyanurate group and a modified polyisocyanate of hexamethylene diisocyanate having at least an isocyanurate group, and having both flexibility and drying properties, And a method for producing the same and a curing agent for paints using the same.

[0002]

2. Description of the Related Art Isocyanurate-modified polyisocyanates have excellent properties such as weather resistance and heat resistance due to isocyanurate groups, and high reactivity due to isocyanate groups. Therefore, they are used as curing agents for paints, adhesives and coating agents. Widely used. JP-A-5-32759 describes an isocyanurate-modified polyisocyanate of hexamethylene diisocyanate and a paint using the same. JP-A-6-166677 describes a method for producing an isocyanurate-modified polyisocyanate using a specific catalyst. It is stated that hydrogenated xylylene diisocyanate can be used. This isocyanurate-modified hydrogenated xylylene diisocyanate has a high glass transition temperature, and thus has a characteristic of having good drying properties when used in a coating material.

[0003]

However, the paint using the polyisocyanate described in JP-A-5-32759 has insufficient drying properties, and the coating composition disclosed in JP-A-6-16.
No. 6,677 does not describe the characteristics and effects of isocyanurate-modified polyisocyanate of hydrogenated xylylene diisocyanate. In addition, the isocyanurate-modified hydrogenated xylylene diisocyanate had a high viscosity, so that its workability was poor and it was difficult to mix it with other isocyanates.

[0004]

As a result of intensive studies, the present inventors have found that a polyisocyanate composition having a specific structural composition, a method for producing the same, and a paint using the same can solve the above-mentioned problems. The present invention has been completed.

That is, the present invention provides the following (1) to (3)
It is. (1) The weight ratio of hydrogenated xylylene diisocyanate-modified polyisocyanate (A) having at least isocyanurate groups and hexamethylene diisocyanate-modified polyisocyanate (B) having at least isocyanurate groups is (A) :( B) = 1: 99-6
5:35 and a viscosity of 10 to 50,000 cS
Polyisocyanate composition characterized by t / 25 ° C.

(2) The method for producing a polyisocyanate composition according to the above (1), comprising at least the following steps: (A) a step of isocyanurate-modifying a polyisocyanate using hydrogenated xylylene diisocyanate to synthesize a polyisocyanate containing a hydrogenated xylylene diisocyanate-modified polyisocyanate (A) having at least an isocyanurate group; (B) a step of mixing the polyisocyanate obtained in (a) with a polyisocyanate containing a modified polyisocyanate (B) of hexamethylene diisocyanate having at least an isocyanurate group. (C) a step of removing free isocyanate monomers from the polyisocyanate mixture obtained in (b).

(3) A curing agent for paints, comprising using the polyisocyanate composition according to (1).

[0008]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in more detail. The polyisocyanate composition of the present invention comprises a modified polyisocyanate (A) of hydrogenated xylylene diisocyanate (hereinafter abbreviated as H ₆ XDI) having at least an isocyanurate group, and a hexamethylene diisocyanate having at least an isocyanurate group (hereinafter referred to as HDI). Abbreviated as "). (A) is an isocyanurate-modified polyisocyanate of an organic polyisocyanate containing H ₆ XDI as a main component, and (B) is an isocyanurate-modified polyisocyanate of an organic polyisocyanate containing HDI as a main component.

The weight ratio of (A) and (B) in the polyisocyanate composition of the present invention is (A) :( B) = 1: 9
9 to 65:35, preferably (A) :( B) = 5: 95
６０60: 40. When (A) exceeds the upper limit, the coating film tends to become brittle. When (A) is less than the lower limit, drying of the coating film tends to be slow.

[0010] The polyisocyanate composition of the present invention may be diluted to an arbitrary solid content with an organic solvent inactive with isocyanate groups known in the polyurethane industry. Examples of the organic solvent include aromatic hydrocarbon solvents such as toluene, xylene, swazol (manufactured by Cosmo Oil) and solvesso (manufactured by Exxon Chemical), aliphatic hydrocarbon solvents such as hexane, cyclohexane, and the like. Alicyclic hydrocarbon solvents such as isophorone, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, ester solvents such as ethyl acetate, butyl acetate and isobutyl acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl Ether acetate, propylene glycol 3-
Examples include glycol ether ester solvents such as methyl-3-methoxybutyl acetate and ethylene glycol ethyl-3-ethoxypropionate, and ether solvents such as tetrahydrofuran and dioxane. The solvent may contain one kind or two or more kinds.

The polyisocyanate composition of the present invention has an isocyanate content of 10 to 30% by weight, preferably 15 to 25% by weight in terms of solids. When the isocyanate content is less than the lower limit, the viscosity is inevitably too high, resulting in poor workability. On the other hand, when the ratio exceeds the upper limit, the coating film becomes brittle because the crosslinking density of the coating film becomes too high.

The viscosity of the polyisocyanate composition of the present invention is 10 to 50,000 cSt / 25.degree.
３０30,000 cSt / 25 ° C. When the viscosity exceeds the upper limit, workability is poor.

The polyisocyanate composition of the present invention has a color number of 400 APHA or less, preferably 100 APHA or less. When the number of colors exceeds the upper limit, the appearance tends to be poor when the paint is used.

The content of free isocyanate monomer in the polyisocyanate composition of the present invention is 1% by weight or less, preferably 0.9% by weight or less. When the content of the free isocyanate exceeds the upper limit, it causes rash and odor.

Next, a method for producing the polyisocyanate composition of the present invention will be described. The method for producing the polyisocyanate composition of the present invention includes at least the following (A) to (I).
(C). (B) and isocyanurate-modified polyisocyanate with H ₆ XDI, thereby synthesizing a polyisocyanate containing H ₆ XDI of modified polyisocyanate (A) having at least isocyanurate groups. (B) a step of mixing the polyisocyanate obtained in (a) with a polyisocyanate containing a modified polyisocyanate (B) of HDI having at least an isocyanurate group. (C) a step of removing free isocyanate monomers from the polyisocyanate mixture obtained in (b).

First, the process (a) will be described. In the step (a), at least one selected from the following (a) to (c) is isocyanurate-modified to obtain a polyisocyanate (A) containing at least an H ₆ XDI-modified polyisocyanate (A) having an isocyanurate group. This is a step of synthesizing an isocyanate. (A) H ₆ XDI. (B) H ₆ XDI and a mixture of organic polyisocyanates other than H ₆ XDI. (C) An isocyanate group-containing prepolymer obtained by reacting the above (a) or (b) with an active hydrogen group-containing compound described below. The polyisocyanate used in the step (a) is H ₆
XDI was used in an amount of 50% by weight or more.

Examples of organic polyisocyanates other than H ₆ XDI include 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 2,2′-diphenylmethane diisocyanate,
2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenyl ether diisocyanate, 2-nitrodiphenyl-4,4'-diisocyanate, 2,2'-diphenylpropane-4,
4'-diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 4,4'-diphenylpropane diisocyanate, o-phenylene diisocyanate, m-phenylene diisocyanate, p
-Aromatic diisocyanates such as phenylene diisocyanate, 1,4-naphthalene diisocyanate, 1,5-naphthalene diisocyanate, 3,3'-dimethoxydiphenyl-4,4'-diisocyanate, tetramethylene diisocyanate, HDI, decamethylene diisocyanate, lysine diisocyanate Such as aliphatic diisocyanate, o-xylene diisocyanate, m-xylene diisocyanate, p-xylene diisocyanate,
Aliphatic diisocyanates other than H ₆ XDI, such as araliphatic diisocyanates such as tetramethyl xylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and hydrogenated tetramethyl xylene diisocyanate. Further, these organic diisocyanates such as urethane-modified polyisocyanate, allophanate-modified polyisocyanate, urea-modified polyisocyanate, biuret-modified polyisocyanate, isocyanurate-modified polyisocyanate, uretonimine-modified polyisocyanate, uretdione-modified polyisocyanate, and carbodiimide-modified polyisocyanate. Modified polyisocyanates can also be used. Further, what is called a polymer, such as polyphenylene polymethylene polyisocyanate and crude tolylene diisocyanate, can also be used. These organic polyisocyanates can be used alone or as a mixture of two or more.

The above-mentioned active hydrogen group-containing compound is a compound having one or more active hydrogen groups in one molecule and having a number average molecular weight of 18 to 1
000 compounds. Examples of the active hydrogen group-containing compound include methanol, ethanol, n-propanol, i-propanol, n-butanol, s-butanol, t-butanol, pentanol, hexanol, heptanol, octanol, and 2-ethyl-hexanol. , Benzyl alcohol, methylbenzyl alcohol, caprylic alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, lauryl alcohol
, Tridecyl alcohol, myristyl alcohol, pentadecyl alcohol, cetyl alcohol, cinnamyl alcohol, monools such as polyolefin having one hydroxyl group, ethylamine, butylamine, pentylamine, hexylamine , Heptylamine, octylamine, benzylamine, 2-ethyl-hexylamine, methylbenzylamine, caprylamine, nonylamine,
Monoamines such as decylamine, undecylamine, laurylamine, tridecylamine, myristylamine, pentadecylamine, cetylamine, cinnamylamine, N-methylheptylamine, N-methyloctylamine and N-methylbenzylamine; Polyether monools to which an alkylene oxide such as ethylene oxide or propylene oxide has been added using a monol or monoamine as an initiator, α-oxypropionic acid, oxysuccinic acid, dioxysuccinic acid, ε-oxypropane-1,2,3 Oxycarboxylic acids such as tricarboxylic acid, hydroxyacetic acid, α-hydroxybutyric acid, hydroxystearic acid, ricinoleic acid, ricinoelaidic acid, ricinostearolic acid, salicylic acid, and mandelic acid;
Glycine, alanine, valine, aspartic acid, neutral or acidic amino acids such as glutamic acid, esters having one hydroxyl group or one amino group obtained by reacting the aforementioned oxycarboxylic acids with the aforementioned monols or monoamines, Ethylene glycol, 1,2-propanediol,
1,3-propanediol, 1,2-butanediol,
1,3-butanediol, 1,4-butanediol,
1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 2-ethyl-2-n-butyl-1,3
-Propanediol, 1,8-octanediol, 1,
Low molecular weight compounds having a number average molecular weight of 500 or less such as 9-nonanediol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanedimethanol, or ethylene oxide or propylene oxide adduct of bisphenol A, trimethylolpropane, glycerin, pentaerythritol and the like. Polyols, hexamethylenediamine, xylylenediamine, low molecular weight polyamines having a number average molecular weight of 500 or less such as isophoronediamine, monoethanolamine, diethanolamine, triethanolamine, monopropanolamine, dipropanolamine, tripropanolamine, etc. Low molecular weight polyamino alcohols having a number average molecular weight of 500 or less, succinic acid, adipic acid, sebacic acid, azelaic acid, terephthalic acid, isophthalic acid , Orthophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, hexahydroorthophthalic acid, naphthalenedicarboxylic acid, polycarboxylic acid such as trimellitic acid, acid ester, or one or more of acid anhydride and the above-mentioned low Polyols, low molecular weight polyamines, polyester polyols and polyester amide polyols obtained by reaction with at least one of low molecular weight amino alcohols, and low molecular weight polyols, low molecular weight polyamines, low molecular weight amino alcohols as initiators,
lactone-based polyester polyols obtained by ring-opening polymerization of cyclic ester (lactone) monomers such as ε-caprolactone and γ-valerolactone, and the above-mentioned low-molecular-weight polyols and diethylene carbonate, dimethyl carbonate, diethyl carbonate, diphenyl carbonate, etc. Ring opening of ethylene oxide, propylene oxide, tetrahydrofuran, etc., using polycarbonate polyols obtained by dealcoholation reaction, dephenolization reaction, etc., low molecular polyol, low molecular polyamine, low molecular amino alcohol used in the above-mentioned polyester polyol as an initiator. Polymerized polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc., and polyether polyols obtained by copolymerizing these, Polyester polyols having an ester polyol, a polycarbonate polyol as an initiator, polybutadiene having two or more hydroxyl groups, hydrogenated polybutadiene, polyisoprene, hydrogenated polyisoprene, polyolefin polyols such as chlorinated polypropylene, chlorinated polyethylene, and castor oil. -Based polyols, animal and plant-based polyols such as silk fibroin, dimer acid polyols having an average of at least one active hydrogen group in one molecule, hydrogenated dimer acid polyols, as well as epoxy resins, polyamide resins, polyester resins, acrylics Examples include resins, rosin resins, urea resins, melamine resins, phenol resins, coumarone resins, resins containing active hydrogen groups such as polyvinyl alcohol, water, and the like.
These may be used alone or in combination of two or more.

Preferred as the polyisocyanate used in the step (a) are H ₆ XDI, an isocyanate group-containing prepolymer of H ₆ XDI and a low molecular weight diol having 2 to 20 carbon atoms, or a mixture thereof. At the time of synthesizing the isocyanate group-containing prepolymer, a known urethanization catalyst may be used.

Examples of the isocyanurate-forming catalyst used in the isocyanurate-forming reaction include tetraalkylammonium hydroxides such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, and tetrabutylammonium hydroxide; tetramethylammonium acetate; Salts, organic weak acid salts such as tetrabutylammonium acetate, trimethylhydroxypropylammonium hydroxide, trimethylhydroxyethylammonium hydroxide, triethylhydroxypropylammonium hydroxide, trialkylhydroxyalkylammonium hydroxide such as triethylhydroxyethylammonium hydroxide, vinegar Trimethyl hydroxypropyl ammonium salts, acetate trimethyl hydroxyethyl ammonium salts, triethylammonium acetate hydroxypropyl ammonium salts, organic weak acid salt, such as triethylammonium acetate hydroxyethyl ammonium salts, triethylamine, tertiary amines such as triethylenediamine, acid, caproic acid, octyl acid,
All known substances such as metal salts of alkyl carboxylic acids such as myristic acid can be used.

The amount of the isocyanuration catalyst to be added is selected from the range of 10 to 10,000 ppm based on the reaction system. On the other hand, if the isocyanurate-forming reaction proceeds too much, gelation is likely to occur, so that the desired shape cannot be obtained. Therefore, the reaction rate is 40% or less, and further 3%.
5% or less is preferable. However, the isocyanuration reaction has a very high initial reaction rate, and it is very difficult to stop the reaction at an early stage. Therefore, the reaction conditions such as the reaction temperature, the amount added, and the method of addition must be carefully selected. As a method for adding the catalyst, there may be mentioned, for example, batch addition, division addition and the like. In the case of divisional addition, the charged amounts of the respective catalysts may be the same or different. In addition, the reaction temperature of the isocyanuration is 0 to 120 ° C, preferably 20 to 100 ° C.

Examples of the catalyst poison used for stopping the isocyanuration reaction include known acids such as inorganic acids such as phosphoric acid and hydrochloric acid, organic acids having sulfonic acid and sulfamic acid groups, and esters and acyl halides thereof. Can be used.

In this way, first, a polyisocyanate containing the modified polyisocyanate (A) of H ₆ XDI having at least an isocyanurate group is obtained.
In addition, this polyisocyanate may have a urethane group, an allophanate group, a urea group, a biuret group, a uretdione group, a uretonimine group, a carbodiimide group, etc. in addition to an isocyanurate group in some cases.

Next, the step (b) will be briefly described. The step (b) is a step of mixing the polyisocyanate obtained in the above step (a) with a polyisocyanate containing a modified polyisocyanate (B) of HDI having at least an isocyanurate group.

The method for producing a polyisocyanate containing the modified polyisocyanate (B) of HDI having at least an isocyanurate group basically comprises the step (a)
Other replacing H ₆ XDI the HDI in is the same way. However, since HDI has a low vapor pressure, it is more preferable to remove the free isocyanate monomer after the isocyanurate modification. In addition, this polyisocyanate may have a urethane group, an allophanate group, a urea group, a biuret group, a uretdione group, a uretonimine group, a carbodiimide group, etc. in addition to an isocyanurate group in some cases.

The HDI-modified polyisocyanate having at least isocyanurate groups has an isocyanate content of 10 to 30% by weight, preferably 15 to 30% by weight in terms of solid content.
２５25% by weight. When the isocyanate content is less than the lower limit, the workability is likely to deteriorate because the viscosity is often high. In addition, when it exceeds the upper limit, a sufficient amount of isocyanurate groups are often not generated, and heat resistance,
Durability and the like are likely to be insufficient.

The HDI modified polyisocyanate having at least isocyanurate groups has a viscosity of 10 to 2
000 cSt / 25 ° C., preferably 10 to 15.0
00cSt / 25 ° C. If the viscosity exceeds the upper limit, (c) the viscosity of the composition before the step of removing free isocyanate monomer becomes too large, and the content of free isocyanate monomer in the polyisocyanate composition of the present invention as a final product is 1% by weight. % Or less.

H having at least an isocyanurate group
The color number of the modified polyisocyanate of DI is 400 APHA
Or less, preferably 100 APHA or less. When the number of colors exceeds the upper limit, the appearance tends to be poor when the paint is used.

H having at least an isocyanurate group
The content of the free isocyanate monomer in the DI-modified polyisocyanate is preferably 1% by weight or less, and more preferably 0.9% by weight or less because rash and odor can be prevented.

In the modified polyisocyanate of HDI having at least an isocyanurate group, a urethane group, an allophanate group, a urea group, a biuret group, a uretdione group, a uretonimine group, a carbodiimide group may be contained in addition to the isocyanurate group. And the like.

The mixing ratio of the polyisocyanate (P1) obtained in the step (a) and the polyisocyanate (P2) containing a modified polyisocyanate of HDI having at least an isocyanurate group is P1: P2 = 20 to
90:80 to 10 (weight ratio), preferably 25 to 85:
75 to 15 (weight ratio). If P1 is larger than this ratio, the viscosity of the finally obtained polyisocyanate composition will be high, and workability will be poor. In addition, when P2 is large, the drying property is deteriorated.

Next, the step (c) will be described. Step (c) is a step of removing free isocyanate monomers from the polyisocyanate mixture described above. The method for removing the free isocyanate monomer is not particularly limited, and examples thereof include methods such as thin film distillation and solvent extraction. The preferred removal method in the present invention is a thin-film vacuum distillation method under the following conditions: reduced pressure: 10 Torr or less, temperature: 1
20 to 220 ° C, preferably, the degree of reduced pressure: 5 Torr or less, and the temperature: 130 to 220 ° C.

The polyisocyanate composition thus obtained may be further diluted with the above-mentioned organic solvent inert to isocyanate groups or reacted with a compound containing an active hydrogen group.

Thereafter, if necessary, various additives may be blended. Examples of additives include pigments, dyes, thixotropic agents, antioxidants, ultraviolet absorbers, defoamers, thickeners, dispersants, surfactants, fungicides, antibacterial agents, preservatives, catalysts, and fillers. Agents and the like. The blending method is not particularly limited, and a known method is used.

The curing agent for paint of the present invention uses the above-mentioned polyisocyanate composition. In addition, the resin used as the main component of the paint is preferably a resin having an active hydrogen group. Specifically, the resin is modified with a polyurethane resin, a polyamide resin, a saturated or unsaturated polyester resin, a saturated fatty acid or an unsaturated fatty acid. Alkyd resin, acrylic resin, fluorine resin, epoxy resin, cellulose resin and the like can be mentioned. Furthermore, in consideration of coating performance and cost such as gloss, texture, hardness, durability, flexibility, and drying property, saturated or unsaturated polyester resin, alkyd resin modified with saturated fatty acid or unsaturated fatty acid, acrylic resin Resins are preferred.

The compounding ratio of the main agent and the curing agent is such that the active hydrogen group / isocyanate group is from 9: 1 to 1: 9, preferably from 6: 4 to the molar ratio of the active hydrogen group to the isocyanate group in the system.
The range is 4: 6. Examples of the coating equipment include known equipment such as an airless sprayer, an air sprayer, an electrostatic coater, an immersion, a roll coater, and a brush.

The conditions for curing the coated film after coating are not particularly limited, but heating is advantageous in shortening the working time because the curing reaction is accelerated. If heating, 40-150
C is preferred.

[0038]

EXAMPLES The present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples. In Examples and Comparative Examples, “parts” were used.
Means "parts by weight", and "%" means "% by weight".

[Synthesis of Isocyanurate-Modified Polyisocyanate of H ₆ XDI] Synthesis Example 1 1000 parts of H ₆ XDI was charged into a reactor equipped with a stirrer, a thermometer, a nitrogen inlet tube and a reflux condenser. Was replaced with nitrogen and stirred at 50 ° C. Next, while maintaining the temperature at 50 ° C., 2.0 parts, 1.0 part, 0.5 part of the catalyst (A) was added.
The mixture was added in three portions, and the isocyanurate-forming reaction was performed. The catalyst (A) was added every three hours. The isocyanate content was measured every hour after the third addition of the catalyst (A), and when it reached 37.8%, 0.643 parts of the catalyst poison (A) was added.
Stirring was continued for an hour and cooled to room temperature. FT-IR measurement and
^13C -NMR measurement confirmed the presence of isocyanate and isocyanurate groups. This undiluted solution is H ₆ XDI-A
And The measured isocyanate content of H ₆ XDI-A, was 37.7%.

Synthesis Example 2 The same reactor as in Synthesis Example 1 was charged with 1000 parts of H ₆ XDI, and the reactor was purged with nitrogen and stirred at 50 ° C. Next, while maintaining the temperature at 50 ° C., 20 parts of the catalyst (B) was added to cause an isocyanurate-forming reaction. The isocyanate content was measured every hour after the addition of the catalyst (B).
When it reaches 7.8%, catalyst poison (B) 12.8 parts,
2.1 parts of catalyst poison (C) was added, and the mixture was stirred at 50 ° C. for 2 hours to complete the termination reaction. Then, it cooled to normal temperature.
FT-IR measurement and ¹³ C-NMR measurement confirmed the presence of isocyanate groups and isocyanurate groups. This stock solution is designated as H ₆ XDI-B. The measured isocyanate content of H ₆ XDI-B, was 37.3%.

Synthesis Example 3 Into the same apparatus as in Synthesis Example 1, 1,000 parts of H ₆ XDI was charged, 14 parts of 1,3-BD was added, the atmosphere in the reactor was replaced with nitrogen, and the reaction was carried out at 70 ° C. for 4 hours. . Then, the mixture was cooled to 50 ° C., and 5 parts of the catalyst (C) was added.
For an isocyanurate reaction. After adding the catalyst (C), the isocyanate content was measured every hour,
When the content reached 7.0%, 3 parts of catalyst poison (D) was added, and the mixture was stirred at 50 ° C. for 2 hours to complete the termination reaction. Then, it cooled to normal temperature. FT-IR measurement and ¹³ C-NM
R measurement confirmed the presence of isocyanate and isocyanurate groups. This stock solution is designated as H ₆ XDI-C. H
_{6 When} the isocyanate content of XDI-C was measured,
36.9%. Table 1 shows the raw materials used in Synthesis Examples 1 to 3.

[0042]

[Table 1]

The details of the reagents used in Synthesis Examples 1 to 3 and Table 1 are shown below. 1,3-BD: 1,3-butanediol Catalyst (A): 15% solution of tetrabutylammonium salt of capric acid in tetrahydrofuran (THF) Catalyst (B): 10% THF solution of potassium isovalerate Catalyst (C) : 2,4,6-tris (dimethylaminomethyl) phenol Catalyst poison (A): Diphenyldichlorosilane Catalyst poison (B): 10% THF solution of cyclohexylsulfamic acid Catalyst poison (C): 2-ethylhexyl acid phosphate Catalyst poison (D): phosphoric acid

[Synthesis of Polyisocyanate Composition] Example 1 The H ₆ X obtained in Synthesis Example 1 was placed in the same reactor as in Synthesis Example 1.
294 parts of DI-A and 706 parts of coronate HX were charged, and the inside of the reactor was replaced with nitrogen and stirred at room temperature for 1 hour. Using a falling-type thin-film distillation apparatus, the mixed solution was heated at 180 ° C.
Distillation was performed at 0.2 Torr to remove free isocyanate monomer. The obtained liquid is a pale yellow transparent liquid having an isocyanate content of 21.1% and a viscosity of 3,500 cSt.
/ 25 ° C, the color number was 30 APHA, and the yield was 78.5%. This is C-1.

Examples 2 to 10 and Comparative Examples 1 to 5 C-2 to 10 and D-1 to 5 were obtained by using the raw materials shown in Tables 2 to 4 in the same manner as in Example 1. . D-
5 is Coronate HX itself. Tables 2 to 4 show the amounts of the stock solutions used in Examples 1 to 9 and Comparative Examples 1 to 5, the yield of the distillate, the isocyanate content, the viscosity and the number of colors.

[0046]

[Table 2]

[0047]

[Table 3]

[0048]

[Table 4]

Examples 1 to 10, Comparative Examples 1 to 5, Tables 2 to 4
The details of the reagents used are shown below. Coronate HX: HDI isocyanurate-modified polyisocyanate (Nippon Polyurethane Industry) Isocyanate content = 21.3% Viscosity = 2,300 cP / 25 ° C. Free isocyanate content = 0.3%

[Evaluation of Drying Property of Polyisocyanate Composition] Example 11 An acrylic resin for paint (trade name: Acridic A-801) was prepared by mixing C-1 to a solid content of 50% with a mixed solvent.
Made by Dainippon Ink and Chemicals, solid content 50%, hydroxyl value 5
0 mgKOH / g) at a molar ratio of isocyanate groups to hydroxyl groups of 1: 1 and then a 50 μm applicator was used to form a coating on a glass plate.
Then, the film was placed in a dryer at 50 ° C., and the time until the coated film was touched with a finger and no longer felt tacky (tack free time) was measured. After the application, the film was placed in a drier at 50 ° C., and a metal cylinder having a diameter of 1.1 cm was applied to the coating by 0.53 kgf / cm ^2.
For 10 seconds, and a time (dry-through time) until no trace of the cylinder was left was measured. Table 5 shows the evaluation results.

Examples 12 to 20, Comparative Examples 6 to 10 C-1 of Example 11 was replaced with C-2 to 10 and D-1 respectively.
A coating material was prepared and evaluated in the same manner as in Example 11 except that the coating composition was replaced with Nos. To 5. Tables 5 and 6 show the evaluation results.

[0052]

[Table 5]

[0053]

[Table 6]

The details of the mixed solvents used in Examples 11 to 20 and Comparative Examples 6 to 10 are shown below. Mixed solvent: butyl acetate / ethyl acetate / toluene / PGMA = 1/1
/ 1/1 (weight ratio) PGMA: Propylene glycol monomethyl ether acetate

According to Examples 11 to 20, the mixture of the isocyanurate-modified polyisocyanate of H ₆ XDI and the isocyanurate-modified polyisocyanate of HDI is as follows.
It can be seen that the time to reach tack and dry is significantly shorter than that of the isocyanurate-modified polyisocyanate of HDI alone, and the drying property is improved.

[Evaluation of Physical Properties of Coating Film] Example 21 An acrylic resin for coating (Acrydic A-801), titanium oxide and a mixed solvent were mixed in the amounts shown in Table 7, and the same amount of glass beads was added. 1 with a paint shaker
The mixture was shaken for a time to prepare a base material of the paint. Next, C-1 and the mixed solvent were blended in the amounts shown in Table 7 and mixed with the base material prepared above to prepare a coating material. This is 50μ dry film thickness
m and applied at 20 ° C and 65% humidity.
After curing for a week, various coating film physical properties were evaluated. All of the coating film property evaluation methods were measured according to JIS K5400. Table 7 shows the results.

Examples 22 to 30, Comparative Examples 11 to 15 In place of C-1 of Example 21, C-2 to 10 and D-1
Example 5 was blended in the amounts shown in Tables 7 to 9 using
A coating material was prepared in the same manner as in No. 1. This was evaluated in the same manner as in Example 21 to evaluate various coating film properties. The results are shown in Tables 7-9.
Shown in

[0058]

[Table 7]

[0059]

[Table 8]

[0060]

[Table 9]

In Examples 21 to 30, Comparative Examples 11 to 15, and Tables 7 to 9, mixed solvents: butyl acetate / ethyl acetate / toluene / PGMA = 1/1
/ 1/1 (weight ratio) PGMA: Propylene glycol monomethyl ether acetate A-801: Acrylic resin for paint (trade name: Acrydic A-801) 50% KOH / g solid content 50%, manufactured by Dainippon Ink and Chemicals, Inc.

The methods for measuring physical properties of the coating films shown in Examples 21 to 30, Comparative Examples 11 to 15, and Tables 7 to 9 are shown below. Specular gloss: The surface of the obtained coating film was measured for reflectance at an incident angle of 60 degrees and a reflection angle of 60 degrees using a gloss meter. Pencil hardness test: The pencil hardness specified in JIS S-6006 was extruded at an angle of 45 degrees and the hardness of the pencil having the highest hardness that would not break the coating film was defined as the hardness of the coating film. Adhesion test: Using a cutter knife with a cutter guide on the coating film, cut 100 square grids of 1 (cross cut tape method) square, and then press a cellophane tape over it, then instantaneously And the state of peeling of the coating film was observed. ：: less than 10% peeled △: 10% or more to less than 50% peeled ×: 50% or more peeled Impact resistance: A ball placed on a coated plate was 0.5 inch in diameter and 500 g (Dupont) (Formula) The weight was hit by the impact of the falling weight, and the highest height at which the coating film did not crack or peel off was measured. Erichsen value: A steel ball was gently pressed from behind the painted surface, and the extrusion distance of the steel ball when the coating film cracked and peeled (breaking distance method) was measured. Bending resistance: With the coated surface facing up, the coated plate was placed on a rod having a diameter of 2 mm and bent 180 degrees to check for cracks and peeling of the coated film. ：: no change ×: cracking or peeling

As in Comparative Examples 13 and 14, H ₆ XDI
In the isocyanurate-modified polyisocyanate alone,
Due to its hard and brittle nature, the coating film was inferior in Erichsen value and bending resistance. On the other hand, Examples 21 to 3 in the present invention
As shown in FIG. 3, the Erichsen value and the flex resistance of the blend of the isocyanurate-modified polyisocyanate of H ₆ XDI and the isocyanurate-modified polyisocyanate of HDI are almost the same as those of the isocyanurate-modified polyisocyanate of HDI alone. Indicates physical properties.

[0064]

As described above, the use of the polyisocyanate composition of the present invention as a curing agent for a paint makes it possible to form a coating film having both dryness and flexibility. The polyisocyanate composition of the present invention can be used for a wide range of paints such as metals, plastics, concrete and wood.

Claims (3)

[Claims] A weight ratio of a modified polyisocyanate of hydrogenated xylylene diisocyanate having at least isocyanurate group (A) and a modified polyisocyanate of hexamethylene diisocyanate having at least isocyanurate group (B) is (A) : (B) = 1:
99-65: 35 and a viscosity of 10-50,0.
A polyisocyanate composition having a temperature of 00 cSt / 25 ° C. 2. A method for producing a polyisocyanate composition according to claim 1, comprising at least the following steps. (A) a step of isocyanurate-modifying a polyisocyanate using hydrogenated xylylene diisocyanate to synthesize a polyisocyanate containing a hydrogenated xylylene diisocyanate-modified polyisocyanate (A) having at least an isocyanurate group; (B) a step of mixing the polyisocyanate obtained in (a) with a polyisocyanate containing a modified polyisocyanate (B) of hexamethylene diisocyanate having at least an isocyanurate group. (C) a step of removing free isocyanate monomers from the polyisocyanate mixture obtained in (b). 3. A curing agent for a paint, comprising using the polyisocyanate composition according to claim 1.