JP2001234117A - Coating material composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coating material which has excellent resistance properties and is rich in elasticity and has excellent compatibility which other resins and excellent adhesion to various plastic molded articles as a coating material. SOLUTION: This coating material composition comprises a polyurethane resin to be obtained by reacting (1) an α,ω-polymethacrylate diol, (2) a polymeric polyol, and (3) a diisocyanate compound or a polyurethane resin to be obtained by reacting (1) an α,ω-polymethane diol, (2) a polymeric polyol, (3) a diisocyanate compound, (4) a chain extender and/or (5) a short-stop agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a novel and useful coating composition.

[0002]

2. Description of the Related Art In recent years, a wide variety of plastic molded articles have been used in various industrial fields such as the construction industry, the automobile industry, the packaging industry, and the audio / visual industry. Polyurethane resins having excellent adhesion and versatility are widely used as coating agents for these various plastic molded products.

[0003] Polyurethane-based coating agents are roughly divided into two types. One type is called a reaction type, which is characterized by being able to be coated with high solids and having a very tough cured film. It is not suitable for line painting, coating, printing, or the like that requires film formation. Reactive polyurethane coating agents include a two-pack type in which a main agent mainly composed of a high molecular weight polyol and an auxiliary agent composed of a polyisocyanate compound are mixed immediately before use, and a one-pack type in which an isocyanate-terminated prepolymer is mixed (moisture curing). Type).

[0004] Another type is called a polymer type (lacquer type). Polyurethane having a molecular weight of tens to hundreds of thousands due to a reaction between a high molecular polyol, a diisocyanate and a chain extender is used as a solvent. It is dissolved. Polymer-type polyurethane-based coating agents have the characteristic that a polymer film can be obtained after the solvent is volatilized by simply applying it, and it is necessary to dry and form a film in a short time. Or it is suitable for printing and the like. When it is desired to form a film in a short time and obtain a very tough film, a tolylene diisocyanate or a diphenylmethane diisocyanate-based polyisocyanate compound may be used. Furthermore, this type
When a chain extender is not used or a so-called pure polyurethane resin using a low molecular weight glycol such as ethylene glycol or 1,6-hexanediol as a chain extender, and a diamine such as ethylene diamine or isophorone diamine is used as a chain extender, It is divided into so-called polyurethane polyurea resins.

[0005] However, polyurethane resins usually use polyether-based polyols or polyester-based polyols as polyols, and thus have the disadvantage that the water resistance of the coating film is poor due to moisture absorption or hydrolysis. In order to improve these, it may be used by mixing with acrylic resin, etc.
Polyurethane resin has poor compatibility with acrylic resin and lacks stability as a coating agent such as paint and ink.
In some cases, a uniform coating may not be obtained. Further, when used in combination with an acrylic resin or the like, the elasticity of the coating film also deteriorates.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a coating agent having excellent resistance, rich elasticity, excellent compatibility with other resins, and excellent adhesion to various plastic molded products. Aimed to provide.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems of the prior art, and as a result, the following problems can be solved by using the following polyurethane resin. This led to the completion of the present invention.

That is, the present invention relates to (1) α, ω-polymethacrylate diol, (2) a polymer polyol,
(3) a coating composition comprising a polyurethane resin obtained by reacting a diisocyanate compound;
(1) α, ω-polymethacrylate diol, (2) polymer polyol, (3) diisocyanate compound,
The present invention relates to a coating composition comprising a polyurethane resin obtained by reacting (4) a chain extender and / or (5) a polymerization terminator.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) α, ω used in the present invention
-The polymethacrylate diol is not particularly limited as long as it is a polymethacrylate having two hydroxyl groups at terminals, and a known one can be used. Examples of the monomer species constituting the polymethacrylate portion include methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, trifluoroethyl methacrylate and the like. Of various methacrylate monomers. (1) α, ω-Polymethacrylate diol is prepared by the iniferter method [for example, Journal of Polymer.
Science (J. Polym. Sci .: Part
A: Pol. Chem. ), 27, 1795-1809
(1989)] or a monohydroxy polymethacrylate transesterification method (for example, Japanese Patent No. 2690457).

(2) Polymer polyols include, for example, polyether polyols such as polymers or copolymers of ethylene oxide, propylene oxide, tetrahydrofuran, etc .; ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol , 1,
3-propanediol, 1,3-butanediol, 1,
4-butanediol, neopentyl glycol, pentanediol, 3-methyl-1,5-pentanediol,
1,6-hexanediol, octanediol, 1,4
-Various known saturated or unsaturated low molecular weight glycols such as butynediol and dipropylene glycol, or n
Alkyl glycidyl ethers such as -butyl glycidyl ether and 2-ethylhexyl glycidyl ether; glycidyl esters of monocarboxylic acid such as glycidyl versatate; adipic acid, maleic acid, fumaric acid, phthalic anhydride, isophthalic acid, and terephthalic acid ,
Polyester polyol obtained by dehydration-condensation with dibasic acids such as succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, azelaic acid, sebacic acid, suberic acid, or their corresponding acid anhydrides or dimer acids Polyester polyols obtained by ring-opening polymerization of a cyclic ester compound; Other polycarbonate polyols, polybutadiene glycols, bisphenol A
And various known polymer polyols generally used in the production of polyurethane resins, such as glycols obtained by adding ethylene oxide or propylene oxide.

In the case of the above-mentioned (2) high-molecular polyol obtained from a glycol and a dibasic acid in the high-molecular polyol, up to 5 mol% of the glycol is replaced with the following various polyols. Can be. For example, glycerin, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, 1,2,4
-Butanetriol, sorbitol, pentaerythritol and the like.

The number average molecular weight of the (2) high molecular polyol is appropriately determined in consideration of the solubility of the obtained polyurethane resin and the like, and is usually about 500 to 10000, preferably 1000 to 6000. Is good. If the number average molecular weight is less than 500, the stability tends to decrease as the solubility decreases, and if it exceeds 10,000, the elasticity tends to decrease.

Further, within the range not deviating from the performance of the above-mentioned polyurethane resin, a part of the above-mentioned high molecular polyol component can be used by substituting it with a low molecular polyol. It is at most 20% by weight, preferably at most 10% by weight. Examples of the low molecular polyols include various low molecular polyols used for producing the high molecular polyol. If the proportion of the low-molecular polyol exceeds 20% by weight, the resulting coating agent tends to have poor adhesion to plastics, elasticity, and solubility in diluting solvents, which is not preferable.

As the diisocyanate compound (3), various known aromatic, aliphatic or alicyclic diisocyanates can be used. For example, 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3- Phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4- Trimethylhexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate , Hydrogenated xylylene diisocyanate, isophorone diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,
Representative examples thereof include 3-bis (isocyanatomethyl) cyclohexane, methylcyclohexane diisocyanate, m-tetramethylxylylene diisocyanate, and dimer isocyanate obtained by converting a carboxyl group of dimer acid into an isocyanate group.

In the present invention, (4) a chain extender can also be used. (4) Examples of the chain extender include the low molecular weight glycols described in the section of the polyester polyol, or ethylenediamine, propylenediamine, hexamethylenediamine, triethylenetetramine, diethylenetriamine, isophoronediamine, dicyclohexylmethane-4,4'-. Diamines such as diamines and dimer diamines in which a carboxyl group of a dimer acid is converted into an amino group. Further, as the diamines, 2-
Hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine,
Those having a hydroxyl group in the molecule such as di-2-hydroxypropylethylenediamine can also be used.

In particular, when a diamine is used as the chain extender (4) of the present invention, since the polyurethane molecule has a urea bond formed by the reaction of the isocyanate and the diamine, it has a high cohesive force between the molecules, It is possible to have high rubber elasticity with a molecular weight of 10,000, and it is possible to obtain a coating agent with high solids and elasticity compared to a pure polyurethane type using no chain extender or using a low molecular glycol as a chain extender. There are advantages.

In the polyurethane resin of the present invention, (5) a polymerization terminator may be used for controlling the molecular weight. (5) As the polymerization terminator, for example, di-
Examples thereof include dialkylamines such as n-butylamine and alcohols such as ethanol and isopropyl alcohol.

The ratio of (1) to (2) is usually 1/99 to 70/30 by weight (1) / (2).
It is preferable that the temperature is within the range of 5/95 to 60/40. (1) If the ratio of α, ω-polymethacrylate diol is less than 1, water resistance may be poor, and if it exceeds 70, elasticity may not be obtained. When (3) a chain extender and / or (5) a polymerization terminator is not used, (3) a diisocyanate compound is used in an amount of (1) α, ω-polymethacrylate diol and (2) a polymer polyol. It is determined in consideration of the amount of active hydrogen groups. Usually, the equivalent ratio of the isocyanate group of the (3) diisocyanate compound / the active hydrogen group amount of the (1) α, ω-polymethacrylate diol and (2) the polymer polyol is in the range of 0.5 / 1 to 1/1. Is preferred. In the case where (4) a chain extender and / or (5) a polymerization terminator is used, the isocyanate group / active hydrogen group content ((1), (2), (4) and / or (5)) Is preferably in the range of 0.5 / 1 to 1/1.

The method for producing the polyurethane resin of the present invention includes (1) α, ω-polymethacrylate diol, (2) a polymer polyol and (3) a diisocyanate compound, (4) a chain extender and / or (5) When using a polymerization terminator, a one-step method in which (4) a chain extender and / or (5) a polymerization terminator is reacted at once in a suitable solvent may be mentioned. When (4) a chain extender and / or (5) a polymerization terminator is used, (1) α, ω-polymethacrylate diol and (2) a polymer polyol and (3) a diisocyanate compound are used in an excess of an isocyanate group. To prepare (1) an α, ω-polymethacrylate diol and (2) a prepolymer having an isocyanate group at the terminal of a high molecular polyol, and then prepare this in an appropriate solvent to obtain (4) a chain extender. And / or (5) a two-stage method of reacting with a polymerization terminator. The two-stage method is preferred for obtaining a uniform polymer solution. In these production methods, the solvents used are usually aromatic solvents such as benzene, toluene and xylene; ester solvents such as ethyl acetate and butyl acetate; methanol, ethanol, isopropanol, n-butanol, and the like.
Alcohol solvents such as diacetone alcohol; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and the like can be used alone or in combination.

The number average molecular weight of the polyurethane resin of the present invention is appropriately determined in consideration of the obtained film strength, water resistance, viscosity and the like. Usually, the number average molecular weight of the polyurethane resin is preferably in the range of 5,000 to 100,000.

In the above applications, the polyurethane resin of the present invention is generally used as a resin solution. The resin solid content concentration is not particularly limited, and may be appropriately determined in consideration of workability at the time of coating, and is usually about 15 to 60% by weight, and the viscosity is about 50 to 100,000 mPa · s / 25 ° C. It is practically preferable to adjust to.

The coating composition of the present invention contains a polyisocyanate and a solvent in the polyurethane resin. Examples of the polyisocyanate compound include the above-mentioned diisocyanate compounds, adducts of these diisocyanate compounds with polyhydric alcohol or water, and polymers of these diisocyanate compounds. An aromatic polyisocyanate compound is particularly preferable in that high physical properties can be obtained. The addition amount of the polyisocyanate compound is 1 to 40 parts by weight based on 100 parts by weight of the solid content of the polyurethane resin. When the amount is less than 1 part by weight, the improvement of the physical properties of the film is small, and when it exceeds 40 parts by weight, the film becomes too hard and the rubber elasticity may be impaired. The solvent used in the present coating agent is not particularly limited, and known solvents can be used.
Generally, the solvent used in the production of the polyurethane resin is used as it is.

The coating agent of the present invention can be applied as it is or as a clear varnish as it is, or can be used in combination with known coating agent additives such as pigments, dispersants, anti-dripping agents, and ultraviolet absorbers as appropriate. A known dispersing machine such as a ball mill, a sand mill, an attritor and a three-roll mill can be used.

The substrate to which the coating agent of the present invention is applied is preferably a plastic molded product, but can also be applied to paper, wood, metal and the like. When applying the coating composition of the present invention to these substrates,
The coating method is not particularly limited, and various known methods such as brush coating, spraying, dipping, roll coating, gravure printing, and flexographic printing can be employed.

[0025]

The polyurethane resin used in the present invention has excellent adhesiveness, rubber elasticity and water resistance, and also has good compatibility with other resins, and is used as a binder for paints, magnetic tapes, printing inks and the like. And a binder for various coating agents such as surface treatment agents such as overprint varnish. In particular, the polyurethane resin of the present invention is useful as a binder for a coating agent for plastics because it exhibits excellent elasticity and various resistances.

[0026]

EXAMPLES The present invention will be described more specifically with reference to Production Examples, Examples and Comparative Examples, but the present invention is not limited to these Examples. The parts and percentages are based on weight.

Example 1 (Production of Polyurethane Resin) In a round-bottom flask equipped with a stirrer, a thermometer and a nitrogen gas inlet tube, α, ω-methyl methacrylate diol having a number average molecular weight of 1,000 (manufactured by Teha Gold Schmidt)
Product name Tegodiol MD1000) 200 parts,
800 parts of poly (3-methyl-1,5-pentylene adipate) glycol having a number average molecular weight of 2,000 (manufactured by Kuraray Co., Ltd., trade name "Kurapol P2010") and 239 parts of isophorone diisocyanate are charged, and the mixture is charged under nitrogen stream.
Reaction at 0 ° C. for 6 hours, free isocyanate value 3.17%
Prepolymer and none. To this, 531 parts of toluene was added to obtain a uniform prepolymer solution. Then, 37.6 parts of isophorone diamine, 12.9 parts of di-n-butylamine.
Parts, 283 parts of toluene, 584 parts of methyl ethyl ketone and 584 parts of diacetone alcohol in the presence of 1000 parts of the urethane prepolymer solution, and reacted at 50 ° C. for 3 hours. The polyurethane resin solution thus obtained has a resin solid content concentration of 30%, a viscosity of 300 mPa · s / 25 ° C., and a number average molecular weight determined by gel permeation chromatography (GPC) of 150.
00.

Example 2 In a round bottom flask equipped with a stirrer, a thermometer and a nitrogen gas inlet tube, α, ω-methyl methacrylate diol having a number average molecular weight of 1,000 (manufactured by Teha Gold Schmidt Co., Ltd.)
Product name Tegodiol MD1000) 100 parts,
900 parts of poly (3-methyl-1,5-pentylene adipate) glycol having a number average molecular weight of 2000 (manufactured by Kuraray Co., Ltd., trade name "Kurapol P2010") and 219 parts of isophorone diisocyanate are charged, and 10 parts are charged under a nitrogen stream.
Reaction at 0 ° C for 6 hours, free isocyanate value 2.96%
Prepolymer and none. To this was added 523 parts of toluene to obtain a uniform prepolymer solution. Next, 34.5 parts of isophoronediamine, 12.9 parts of di-n-butylamine.
Parts of toluene, 281 parts of toluene, 581 parts of methyl ethyl ketone and 581 parts of diacetone alcohol were added with 1000 parts of the above urethane prepolymer solution, and reacted at 50 ° C. for 3 hours. The polyurethane resin solution thus obtained had a resin solid content concentration of 30%, a viscosity of 500 mPa · s / 25 ° C., and a number average molecular weight by GPC of 16,000.

Example 3 In a round bottom flask equipped with a stirrer, a thermometer and a nitrogen gas inlet tube, α, ω-methyl methacrylate diol having a number average molecular weight of 1,000 (manufactured by Teha Gold Schmidt Co., Ltd.)
Product name Tegodiol MD1000) 500 parts,
500 parts of poly (3-methyl-1,5-pentylene adipate) glycol having a number average molecular weight of 2000 (manufactured by Kuraray Co., Ltd., trade name "Kurapol P2010") and 300 parts of isophorone diisocyanate were charged, and 10 parts were charged under a nitrogen stream.
Reaction at 0 ° C for 6 hours 3.78% free isocyanate value
And 557 parts of toluene was added thereto to obtain a uniform prepolymer solution. Then, 46.3 parts of isophorone diamine and 13.0 parts of di-n-butylamine.
Of the urethane prepolymer solution in the presence of a mixture consisting of 1 part of toluene, 291 parts of toluene, 591 parts of methyl ethyl ketone and 591 parts of diacetone alcohol, and reacted at 50 ° C. for 3 hours. The polyurethane resin solution thus obtained had a resin solid concentration of 30%, a viscosity of 250 mPa · s / 25 ° C., and a number average molecular weight by GPC of 14,000.

Example 4 In a round bottom flask equipped with a stirrer, a thermometer and a nitrogen gas inlet tube, α, ω-methyl methacrylate diol having a number average molecular weight of 1,000 (manufactured by Teha Gold Schmidt Co., Ltd.)
Product name Tegodiol MD1000) 200 parts,
800 parts of poly (3-methyl-1,5-pentylene adipate) glycol having a number average molecular weight of 2,000 and 266 parts of isophorone diisocyanate were charged, and 10 parts were charged under a nitrogen stream.
Reaction at 0 ° C for 6 hours, free isocyanate value 3.88%
Prepolymer and none. To this, 543 parts of toluene was added to obtain a uniform prepolymer solution. Next, 52.0 parts of isophorone diamine, 6.5 parts of di-n-butylamine,
In the presence of a mixture consisting of 290 parts of toluene, 591 parts of methyl ethyl ketone and 591 parts of diacetone alcohol, 1000 parts of the above urethane prepolymer solution was added, and
The reaction was performed at 0 ° C. for 3 hours. The polyurethane resin solution thus obtained has a resin solid content of 30% and a viscosity of 120%.
0 mPa · s / 25 ° C., number average molecular weight by GPC is 3
0000.

Example 5 In Example 1, α, ω-polymethyl methacrylate diol (trade name: Teg, manufactured by Teha Gold Schmidt)
odiol MD1000) is a α, ω-polybutyl methacrylate having a number average molecular weight of 1000 (trade name Tegodiol BD1 manufactured by Teher Gold Schmidt).
000), except that the reaction was carried out. The polyurethane resin solution thus obtained has a resin solid content concentration of 3
0%, the viscosity was 150 mPa · s / 25 ° C., and the number average molecular weight by GPC was 15,000.

Example 6 α, ω-Methyl methacrylate diol having a number average molecular weight of 1,000 (manufactured by Teha Gold Schmidt Co., Ltd.) was placed in a round bottom flask equipped with a stirrer, a thermometer and a nitrogen gas inlet tube.
Product name Tegodiol MD1000) 200 parts,
800 parts of poly (3-methyl-1,5-pentylene adipate) glycol having a number average molecular weight of 2000 (trade name "Kurapol P2010" manufactured by Kuraray Co., Ltd.), 125 parts of isophorone diisocyanate, and 375 parts of toluene were charged.
After adding 0.6 parts of dibutyltin dilaurate as a catalyst, the mixture was reacted at 100 ° C. for 6 hours under a nitrogen stream. Thereafter, 2250 parts of toluene was added to obtain a uniform solution. The polyurethane resin solution thus obtained had a resin solid content concentration of 30%, a viscosity of 100 mPa · s / 25 ° C., and a number average molecular weight by GPC of 30,000.

Comparative Example 1 A round bottom flask equipped with a stirrer, a thermometer and a nitrogen gas inlet tube was charged with poly (3-methyl-1,5-pentylene adipate) glycol (Kuraray Co., Ltd., trade name "Kurapol P2010"). )) Charge 1000 parts and isophorone diisocyanate 200 parts and react at 100 ° C. for 6 hours under a nitrogen stream to obtain a prepolymer having a free isocyanate value of 2.73%. To this is added 514 parts of toluene to add a homogeneous urethane prepolymer solution. And Then, in the presence of a mixture consisting of 31.2 parts of isophorone diamine, 12.8 parts of di-n-butylamine, 279 parts of toluene, 579 parts of methyl ethyl ketone and 579 parts of diacetone alcohol, 1000 parts of the urethane prepolymer solution are added, 50 ℃
For 3 hours. The polyurethane resin solution thus obtained has a resin solid concentration of 30% and a viscosity of 600 mP.
a · s / 25 ° C., number average molecular weight by GPC is 1500
It was 0.

Test Examples 1 to 6 and Comparative Test Example 1 The polyurethane resin varnishes obtained in Examples 1 to 6 and Comparative Example 1 were degreased with isopropyl alcohol.
The solution was spray-coated on a BS plate so that the film pressure after drying became 20 μm, and dried at 80 ° C. for 30 minutes to obtain a coated plate. After the coated plate was allowed to stand at room temperature for one day, the coating film was tested.

Test Method Adhesion: A coated cellophane tape test according to JIS K5400 was performed on the coated surface of the coated plate, and the degree of the remaining coated film was determined. ：: extremely good 良好: good ：: slightly poor ×: poor Flex resistance: bent 180 ° on a 1 / 2-inch mandrel, and the state of the coating film was examined. ：: extremely good ○: good △: slightly poor ×: poor water resistance: the coated plate was immersed in warm water of 40 ° C. for 120 minutes and 240 minutes to check the state of the coating film. ：: extremely good ：: good ：: slightly poor ×: poor Solution stability: After the polyurethane varnish was allowed to stand at room temperature for one day, the separated state of the solution was confirmed. ：: No separation ○: Slightly cloudy △: Cloudy ×: Completely separated Compatibility: Polyurethane varnish and acrylic resin (trade name: Vinylol 92T, methacrylic acid ester copolymer manufactured by Showa Polymer Co., Ltd., nonvolatile content: 40%) ) At a solid ratio of 1: 1
, And toluene was added to form a 20% solution. The solution was allowed to stand at room temperature for one day, and the separated state of the solution was confirmed. ：: no separation ：: slightly turbid △: turbid ×: completely separated Also, the above mixture was applied on a glass plate, dried at room temperature and then forcibly dried at 80 ° C. for 30 minutes, and the compatibility was observed. ◎: Completely transparent ○: Slightly cloudy △: Cloudy ×: Completely separated

[0036]

[Table 1]

Claims (6)

[Claims] 1. A coating composition comprising (1) α, ω-polymethacrylate diol, (2) a polymer polyol, and (3) a polyurethane resin obtained by reacting a diisocyanate compound. 2. A reaction product obtained by reacting (1) α, ω-polymethacrylate diol, (2) a polymer polyol, (3) a diisocyanate compound, (4) a chain extender and / or (5) a polymerization terminator. A coating composition comprising a polyurethane resin. 3. Use ratio of (1) α, ω-polymethacrylate diol and (2) polymer polyol (1) /
The coating composition according to claim 1 or 2, wherein (2) is 1/99 to 70/30 by weight. 4. A number average molecular weight of 5,000 to 100,000
The coating composition according to any one of claims 1 to 3, wherein 5. The coating composition according to claim 2, wherein the chain extender is a diamine. 6. A plastic coating composition comprising the polyurethane resin according to claim 1.