JPH0428782A - Resin for non-yellowing polyurethane coating having excellent weather resistance - Google Patents

Abstract

PURPOSE:To provide the subject resin having excellent dryness, weather resistance, light stability, heat resistance, etc., and good appearance and coating performance, and suitable for coating vehicles, etc., by compounding a specific polyisocyanate and a compound having plural active hydrogen atoms. CONSTITUTION:The objective resin comprises (A) polyisocyanates containing >=10wt.% of a polyisocyanate obtained by the cyclic trimerization of 2,5-and/or 2,6-diisocyanatomethyl-bicyclo[2,2,1]heptane and having isocyanurate bonds and (B) a compound such as an alkanepolyol, polyetherpolyol or polyesterpolyol having plural active hydrogen atoms.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a two-component urethane paint resin.

More specifically, 2,5- and/or 2,6-diisocyanatomethyl-bicyclo[2,2,1]heptane (hereinafter referred to as B
It is abbreviated as CHI. This invention relates to a two-component urethane paint resin with excellent drying properties and weather resistance, comprising a polyisocyanate containing a polyisocyanate having isocyanurate bonds obtained by cyclic trimerization of ) and a compound containing at least two active hydrogens.

[Conventional technology]

The most typical general-purpose resin for two-component urethane paints is a polyurethane bond containing alkynd resin, polyester polyol, acrylic polyol, or epoxy polyol as the main ingredient and derived from tolylene diisocyanate (abbreviated as TDI). There are examples in which an isocyanate or a polyisocyanate having an isocyanurate bond is used as a curing agent. These are used in furniture, woodworking paints, and heavy-duty corrosion-resistant paints called tar urethane paints.

However, urethane paints using TDI have extremely poor weather resistance, so in order to improve weather resistance,
hexamethylene diisocyanate (abbreviated as HDI),
The curing agent is a polyisocyanate derived from an aliphatic or alicyclic compound such as isophorone diisocyanate (abbreviated as IPDI) or 4,4゛-dicyclohexylmethane diisocyanate (abbreviated as HMD I), and the main agent is As a result, a two-component polyurethane paint using acrylic polyol or polyester polyol was devised.

These have excellent characteristics such as weather resistance, flexibility, and abrasion resistance, and have established a solid position in the fields of automobile repair, architectural exteriors, etc. However, they have poor drying properties and are sufficiently cross-linked and strong coatings. To obtain a film, it is necessary to bake at a high temperature or leave it to stand for a long time, so there has been a desire to develop a two-component urethane paint with good weather resistance and excellent drying properties.

[Problem to be solved by the invention]

Conventional two-component urethane paint resins, for example, in the case of TDI, have high reactivity and excellent drying properties, but have extremely poor weather resistance.

In addition, aliphatic polyisocyanates, such as polyisocyanates having urethane bonds derived from MDI (for example, Japanese Patent Publication No. 11146/1983), polyisocyanates having Bulent bonds (for example, JP-A No. 45-1114),
9-134629), polyisocyanates having isocyanurate bonds (for example, Japanese Patent Publication No. 45-279),
82, JP-A-57-150677), polyisocyanates having urethane-modified isocyanurate bonds (e.g., JP-A-57-47321, JP-A-61-111377), and the like are known. .

Furthermore, as the alicyclic polyisocyanate, for example, IPD
Polyisocyanates having a urethane bond derived from I (e.g., Japanese Patent Publication No. 52-50786, Japanese Patent Application Laid-open No. 141897-1988), polyisocyanates having an isocyanurate bond (e.g., Japanese Patent Publication No. 50-47-1988),
No. 988) and the like are known.

Among these polyisocyanates, conventional aliphatic or alicyclic urethane type polyisocyanates have poor drying properties, so two-component urethane paints using these as hardening agents are forced to dry by baking, but they are not heat resistant. Due to its poor properties, baking sometimes leads to unavoidable yellowing and loss of gloss.

In addition, two-component urethane paints using polyisocyanate having isocyanurate bonds derived from HDI as a curing agent have poor compatibility between the curing agent and the main ingredient polyol, especially acrylic polyol, resulting in poor gloss, sharpness, and leveling. The disadvantages are that the properties are reduced and the main ingredients that can be used are limited.

Furthermore, when polyisocyanate derived from IPDI and HMD I is used as a curing agent, the isocyanate groups involved in the reaction are bonded to secondary carbons, so the reactivity is low, and therefore the drying property is extremely low. It had the disadvantage of becoming worse.

In order to solve the problems of these conventional two-component urethanes, the present inventors have made extensive studies and found that a two-component urethane consisting of a polyisocyanate having an isocyanurate bond obtained by cyclic trimerization of BCHI and a polyol compound. The present invention was achieved by discovering that a resin for type urethane paints has excellent drying properties and weather resistance.

[Means to solve problems]

The present invention relates to a two-component urethane paint resin comprising a polyisocyanate (A) containing a polyisocyanate having an isocyanurate bond obtained by cyclic trimerization of BCHI, and a compound (B) containing at least two active hydrogens. .

The polyisocyanate having an isocyanurate bond of BCHI used in the present invention is achieved by a trimerization reaction in the presence of a conventional quantization catalyst.

Examples of the catalyst include tetraalkylammonium hydrooxaodes and organic weak acid salts such as tetramethylammonium, tetraethylammonium, and tetrabutylammonium, trimethylhydroquinepropylammonium, trimethylhydroxoethylammonium, triethylhydroquinepropylammonium, and triethylhydroquine. Hydroxides and organic weak acid salts of hydroxyalkylammonium such as ethyl ammonium, alkali metal salts of alkyl carboxylic acids such as acetic acid, caproic acid, octylic acid, myristic acid, and metal salts of tin, zinc, lead, etc., hexamethyldisilazane, etc. aminosilyl group-containing compounds, triethylamine, tributylamine, N, N'-
Dimethylaniline, N-ethylpiperidine, N,N''-dimethylpiperazine, Manisohi salt of phenolic compound, N
, N'', N''-tris(dimethylaminepropyl)-hexahydrosym-)riazine, and other tertiary amines.

The amount of catalyst varies depending on the catalyst used and the reaction temperature, but is usually in the range of 10 ppm-IQ%.

During the reaction, for example, methanol,
Ethanol, butanol, ethylene glycol, 1,3
Examples include alcohols such as -butanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, trimethylolpropane, polypropylene glycol, and phenol.

These alcohols 1 can be added at the same time as the trimerization catalyst, or they can be reacted with BCHI in advance to form a urethane bond before proceeding to the trimerization step.

In particular, polyhydric alcohols such as ethylene glycol, 1.3-butanediol, neopentyl glycol, 2-ethyl-1,3hexanediol, 2.2.4-trimethyl-1,3bentanediol, and trimethylolpropane are trimerized. (Polyisocyanurate) can also be used as a modified side.

The reaction may be carried out with or without a solvent; when a solvent is used, a solvent that is inert to isocyanate groups should of course be selected.

The reaction temperature is usually 20°C to 120°C, preferably 50°C.
A range of ˜90° C. is selected.

The progress of the reaction can be monitored by measuring the NC0% of the reaction solution and measuring the remaining amount of BCHI by gas chromatography.

-G, if the conversion reaction proceeds too much, the viscosity of the product will increase and the compatibility with the polyol will decrease, so the conversion rate of the reaction should be lowered, and unreacted raw materials should be left behind and removed after the reaction is stopped. method is done.

When the reaction reaches the desired conversion rate, a catalyst deactivator such as sulfuric acid or phosphoric acid is added to stop the reaction. After stopping the reaction and removing the deactivated catalyst if necessary, remove excess B.
Remove CHI or solvent. Excess BCHr or solvent can be removed, for example, by a thin M distillation method or a solvent extraction method.

The polyisocyanate containing 10% by weight or more of polyisocyanate having an isocyanurate bond obtained by cyclic trimerization of BCHI used in the present invention may be polyisocyanate obtained by the previous trimerization reaction alone or hexamethylene dicarbonate. It is obtained by mixing modified aliphatic or alicyclic compounds such as isocyanate, isophorone diisocyanate, or 4,4'-dicyclohexylmethane diisocyanate.

The mixing ratio varies depending on the purpose, but unless the polyisocyanate obtained by the previous trimerization reaction is contained in an amount of 10% or more, the effects of improving drying properties, heat resistance, and sharpness will not be exhibited.

Next, the compound containing at least two active hydrogens used in the present invention includes compounds and polymers containing at least two active hydrogens in one molecule.

These specific compounds include, for example, ethylene glycol,
Propylene glycol, β, β'-dihydroxy diethyl ether (diethylene glycol), dipropylene glycol, 1,4-butylene glycol, 1,3-butylene gelicol, 1,6 hexamethylene glycol, neopentyl glycol, polyethylene glycol, polypropylene Glycol, polypropylene - Glycols such as polyethylene glycol and polybutylene glycol; Alkane polyols such as glycerin, trimethylolpropane, hexanetriol, pentaerythritol, xylitol, and sorbitol; and polyhydric alcohols such as glycerin and propylene glycol, singly or in mixtures. , polyether polyols obtained by adding alkylene oxide (e.g., ethylene oxide, propylene oxide, 1,2-butylene oxide, etc.) singly or as a mixture, and by reacting the alkylene oxide with a polyfunctional compound such as ethylenediamine or ethanolamine. Polyether polyols such as polyether polyols, dibasic acids (e.g. succinic acid, adipic acid, sebacic acid, dimer acid, maleic anhydride, phthalic anhydride,
carboxylic acids such as isophthalic acid and terephthalic acid) and a polyhydric alcohol (e.g. ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1.4-butylene glycol, 1.3-butylene glycol, l , 6-
hexamethylene glycol, neopentyl glycol,
Polyester polyol resins obtained by condensation reaction with a single or a mixture selected from the group of glycerin, trimethylolpropane, etc., which can be copolymerized with a polymerizable monomer having one or more active hydrogen per molecule. Acrylic polyols obtained by copolymerizing other monomers, such as active hydrogen-containing acrylic esters (2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, etc.), Hydrogen-containing methacrylic ester (
For example, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, etc.), acrylic acid monoester or methacrylic acid monoester of glycerin, acrylic acid monoester of trimethylolpropane or methacrylic acid Single or mixtures selected from the group of monoesters and acrylic esters (e.g. methyl acrylate,
Methacrylic esters (e.g. methyl methacrylate,
ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, lauryl methacrylate, etc.) and an unsaturated carboxylic acid (
unsaturated amides (e.g. acrylic acid, methacrylic acid, maleic acid, itaconic acid, etc.);
methylol acrylamide, diacetone acrylamide, etc.), other polymerizable monomers (e.g., glycidyl methacrylate, styrene, vinyltoluene, vinyl acetate,
Acrylic polyol resins obtained by polymerization in the presence or absence of a mixture selected from the group consisting of acrylonitrile, etc.), novolac type, β-methylepicro type, cyclic oxirane type, glycidyl ether type, glycol ether type , glycol ether type, epoxidized type of fatty acid unsaturated compound, epoxidized fatty acid ester type, polycarboxylic acid ester type, aminoglycidyl type, halogenated type, resorcin type, etc., and epoxy resins such as fructose, glucose, etc. , sugar, lactose, 2-
Also included are monosaccharides such as methyl glycoxide or derivatives thereof, and aromatic or heterocyclic polyhydric alcohols such as trimethylolbenzene and tris(2-hydroxyethyl) isocyanurate.

These may be used in combination with other compounds containing two or more active hydrogens, such as compounds containing primary or secondary amino groups (such as ethylenediamine, triethylenediamine, hexamethylenediamine,
m-xylylenediamine, diaminodiphenylmethane,
isophorone diamine, diethylene triamine, polyamines obtained by adding various alkylene polyamines and alkylene oxides, N, N"-dimethylethylene diamine, etc.), substituted urea compounds (e.g., N, N" dimethyl urea, N-methyl-N'- cyclohexylurea, etc.), thiol group-containing compounds (e.g., 1,2-ethanedithiol, 1,6-hexanedithiol, polyether polyol, polyester polythiol, etc.), carboxyl group-containing compounds (e.g., succinic acid, adipic acid, sebacic acid, etc.) , terephthalic acid, carboxy group-terminated polybutadiene, etc.) or compounds containing different active hydrogen-containing groups in one molecule (e.g., monoethanolamine, thioethanolamine, lactic acid, β-alanine, etc.). Mixed use is also possible.

Although various active hydrogen-containing compounds have been specifically exemplified above,
The active hydrogen-containing compound of the present invention is not limited to these, but any active hydrogen-containing compound that can react with the polyisocyanate used in the two-component urethane paint resin of the present invention to form a urethane resin can be used. can be used and various combinations can be selected.

In the two-component urethane paint resin of the present invention, when mixing both components, a suitable solvent such as hydrocarbons (such as benzene, toluene, xylene, cyclohexane, mineral spirit, naphtha, etc.), ketone 1, etc. may be used as necessary. ! (for example, acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), esters (for example, ethyl acetate, n-butyl acetate, cellosolve acetate, isobutyl acetate, etc.) depending on the purpose and use. Further, these solvents may be used alone or in combination.

Furthermore, various additives used in the technical field, such as catalysts, pigments, leveling agents, antioxidants, desensitizers, and surfactants, can be mixed and used depending on the purpose and use.

In an embodiment of the production of polyurethane resin according to the present invention, the composition according to the present invention is prepared by adding a polyisocyanate and an active hydrogen-containing compound, as well as a solvent and additives depending on the purpose and use, immediately before forming the polyurethane resin. It is usually used at temperatures ranging from room temperature to 150°C.

When used as such a two-component paint, it has excellent adhesion to coated objects such as metal, plastic, rubber, leather, and concrete, so it can be applied to a wide range of applications such as vehicles, equipment, building materials, and woodwork. .

Polyurethane paints generally have excellent adhesion to various objects to be coated, a balance between hardness and flexibility, crack resistance, water resistance, chemical resistance, gloss, and appearance. The polyurethane paint film obtained when using this product also has these various properties, as well as excellent weather resistance and light stability, and also has various superior characteristics compared to commercially available polyurethane paints. ing.

That is, the polyisocyanate having an isocyanurate bond used in the composition of the present invention has higher reactivity and heat resistance than an aliphatic isocyanate, such as a polyisocyanate derived from MDI, so that the initial curing can be improved. It dries quickly, has greatly improved yellowing during baking, has good compatibility, has an excellent appearance, and has coating performance equal to or better than commercially available products, making it ideal for workability, appearance, and coating film for vehicle painting, etc. Suitable for applications where performance is important.

〔Example〕

EXAMPLES Hereinafter, the present invention will be further explained with reference to Examples, but the present invention is not limited to the Examples in any way.

A solution of 1.0 g of dried anhydrous potassium acetate (molecular weight 98.1) of A and A in 9 g of polyethylene glycol having an average molecular weight of 400.

Reference Example 1 200 g (1,188 mol) of 2.5-BCHI was placed in a four-bottle flask equipped with a thermometer, a cooling tube, a nitrogen inlet tube, and a stirring blade, and 1.6 g of catalyst A was added thereto, and the temperature was raised to 80°C.

After 2.5 hours, the NGO content decreased to 24.3%, so 0.25 g of benzoyl chloride was added, and the mixture was stirred at 60°C for 1 hour to deactivate Nikeika Catalyst A. A clear viscous liquid with a slightly yellow color was obtained.

The reaction mass thus obtained was subjected to thin film distillation under a vacuum of 0.2 Torr to remove unreacted 2.5-BCHr.
g of solid was obtained. This was dissolved in 110 g of butyl acetate to obtain an isocyanate solution having an isocyanurate bond having the following resin constant.

Resin constant appearance Light yellow transparent NGO content
9.12 viscosity (Gardner 725℃)
D Solid content (%) 50 Reference example 2 150 g of 2-hydroxyethyl methacrylate, 50 g of methyl methacrylate, and 150 g of n-butyl methacrylate of Acarbool
g, n-butyl acrylate 25g and styrene 125g
and acrylic acid 15g and diethylene glycol 25g and t
-Butylperoxy-2-ethylhexanoate 50g
While stirring the monomer mixture, it was continuously added dropwise into the refluxing liquid of 1200 g of n-butyl acetate over 2 hours.
The mixture was refluxed for an additional 5 hours and then polymerized. After the polymerization reaction was completed, a portion of n-butyl acetate was distilled off to adjust the solid content concentration to 80%.

(The resulting acrylic polyol resin solution has a viscosity of
It had a temperature of 6500 cp/25°C, a number average molecular weight of 1300, and a hydroxyl value of 92.

Reference Example 3 Base Enamel The acrylic resin base enamel produced in Reference Example 2 was blended and prepared as follows.

Acrylic resin manufactured in Reference Example 2: 45 parts Pigment Titanium dioxide R930 (manufactured by Ishiya Sangyo) 45 parts Thinner (xylene/toluene/butyl acetate/methyl isobutyl ketone) 10 parts Blended in the above proportions, and the pigment was mixed using a triple roll. Adjusted the kneaded base enamel.

Example 1, Comparative Examples 1 to 4 The polyisocyanate solution having BCHI isocyanurate bonds obtained in Reference Example 1, the acrylic polyol resin solution shown in Reference Example 2, and the base enamel prepared in Reference Example 3 were mixed into isocyanate solution. The group and hydroxyl group are mixed in equal amounts and the pigment content (PWC) is 40%, and this is mixed with ethyl acetate/toluene/butyl acetate/xylene/cellosolve acetate (weight ratio = 30/30/20/
Add a mixed solvent of 15/5) and use a Ford cup #4.
The temperature was adjusted to 15 seconds/25° C. to obtain a composition for forming a urethane resin of the present invention.

Spray this onto the steel plate and glass plate with a dry film thickness of 25 mm using an air spray gun (IWATAW-77 type, nozzle diameter 2 mm).
Painted so that it becomes μ, room temperature (20°C/60%RH)
After being allowed to stand for 7 days, it was used for testing.

In addition, for comparison with conventional products, three types of polyisocyanates derived from TDI, OLESTAR P75 (manufactured by Mitsui Toatsu Chemical Co., Ltd.) and aliphatic polyisocyanate, namely OLESTAR NP100O (manufactured by Mitsui Toatsu Chemical Co., Ltd.), were selected. Made by
HDI-based billet body), Coronet) EH (manufactured by Nippon Polyurethane ■, HDI-based diisocyanurate body IPDI
Similar tests were conducted using the system T1890 (manufactured by Daicel Huels ■, IPDI-based isodiisocyanurate).

The performance of the composition and the physical properties of the coating film are shown in Table 1.

The coating test was conducted at 20°C/60°C RH, and the evaluation method was based on JIS K-5400.

1) Adhesion: JIS D-0202 2) Erichsen extrusion: JIS Z-22473)
Magic stain resistance: Place the test piece horizontally and apply JISS603 on the surface of the test piece.
7 (1964), draw a line 10×1 in width, leave it for 24 hours, and then wipe it off with a cloth soaked in ethyl alcohol. Based on the results, the following display is performed.

O: No abnormality, Δ: Slight trace left, ×: Clear trace left 4) Xylene rubbing (50 times), the test piece was placed in a dyed material abrasion fastness tester, and the cotton cloth impregnated with xylene 2d Apply a load of 500g and make 50 reciprocations. Depending on the result, the following display will be made.

○: No abnormality, △: Slight trace remains, ×: Substrate visible 5) Acid resistance, alkali resistance: Compliant with JAS 1373. Place the test piece horizontally and apply 10% sulfuric acid water (
10% strength soda water) was added dropwise to the plate, coated clockwise for 24 hours, and then left at room temperature for 24 hours.

Depending on the result, the following display will be made.

○: No abnormality, △: Slight trace left, ×: Clear trace left 6) WOM yellowing degree: JIS K-71037) Gloss (
60" gross) : JIS K-54008) Dupont !l (1/2in1500g) 'JIS
Based on K-5400 9) Secondary physical properties: Measure the physical properties after 4 hours of immersion in boiling water.

Example 2, Comparative Examples 5 to 8 The same tests as in Example 1 were carried out using Olestar Q182 (manufactured by Mitsui Toatsu Chemical Co., Ltd., number average molecular weight 9500, solid content 50%, hydroxyl value 45), which is a typical commercially available acrylic polyol resin. )
This was done using The test was conducted in exactly the same manner as in Example 1 except that the active hydrogen-containing compound component was different.

Further, similar tests were conducted on the four types of commercially available aliphatic polyisocyanates used in Comparative Examples 1 to 4, and the comparison results are shown in Table 2.

The coating film test, evaluation method, etc. are the same as in Example 1.

Example 3 Commercially available Orester N was added to the polyisocyanate solution having BCHI isocyanurate bonds obtained in Reference Example 1.
A test was conducted in exactly the same manner as in Example 2, except that a solution containing P 1000 mixed at a 1/1 weight ratio was used as the isocyanate component. The results are shown in Table 2.

The coating film test, evaluation method, etc. are the same as in Example 1.

Example 4 Commercially available Orester N was added to the polyisocyanate solution having BCHI isocyanurate bonds obtained in Reference Example 1.
A test was conducted in exactly the same manner as in Example 2, except that a solution containing P 1000 mixed at a weight ratio of 115 was used as the isocyanate component. The results are shown in Table 2.

The coating film test, evaluation method, etc. are the same as in Example I.

Example 5, Comparative Examples 9 to 12 The same test as in Example 1 was conducted using a commercially available polyester polyol resin, Olestar Q173 (manufactured by Mitsui Toatsu Chemical Co., Ltd.).
The solid content was 100% and the hydroxyl value was 256). The test was conducted in exactly the same manner as in Example 1 except that the active hydrogen-containing component was different.

The results are summarized in Table 3.

The coating film test, evaluation method, etc. are the same as in Example 1.

〔Effect of the invention〕

The urethane paint of the present invention has significantly superior drying properties (dry to the touch, complete curing, pot life, magic stain resistance, and Kijiroll rubbing) and weather resistance (WOM yellowing degree) compared to conventional urethane paints. is clear from Tables 1 to 3.

Patent applicant: Mitsui Toatsu Chemical Co., Ltd.

Claims (1)

[Claims] 10% by weight or more of polyisocyanate (A) having an isocyanurate bond obtained by cyclic trimerization of 1,2,5,- and/or 2,6-diisocyanatomethyl-bicyclo[2,2,1]heptane A two-component urethane paint resin characterized by having good drying properties and weather resistance, comprising a polyisocyanate and a compound (B) containing at least two active hydrogens.