JPH0551430A - Hardly yellowed type epoxy-modified aqueous polyurethane resin composition - Google Patents

Abstract

PURPOSE:The subject composition containing the reaction product of an carboxyl group-containing aqueous polyurethane resin with an epoxy group-containing bisphenol type epoxy compound, having excellent weather resistance and boiling water resistance, and useful for coatings, adhesives, paper-processing agents, etc. CONSTITUTION:The objective composition containing a product obtained by reacting (A) 100 pts.wt. of a carboxyl group-containing aqueous polyurethane resin with (B) 1-30 pts.wt. of an epoxy group-containing bisphenol type epoxy compound. The composition is obtained by dissolving or suspending the mixture of the carboxyl group-containing urethane prepolymer with the bisphenol type epoxy compound in a solvent, imparting the hydrophilicity to the carboxyl group-containing urethane prepolymer and simultaneously reacting the product with a chain-extending agent by a method in which a basic organic compound and the chain-extending agent are dropped, etc., diluting the reaction product with water, removing the water and the solvent under vacuum up to an nonvotatile matter concentration of 30-40%, and further subjecting the remained product to the reaction at 70-80 deg.C for approximately 6hrs.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-yellowing type epoxy-modified aqueous polyurethane resin composition which is excellent in weather resistance and water resistance and is useful as a paint, an adhesive, paper processing and a surface coating agent.

[0002]

2. Description of the Related Art A yellowing type water-based polyurethane resin is a paint,
Adhesive, water-based ink, leather, paper, metal, plastic,
It is used as a sealer or top coat for wood, rubber, inorganic materials, etc., but it is not always sufficient in terms of weather resistance and water resistance. As a method for solving such a problem, for example, JP-A-2-20511 and JP-A-63-305119.
No. 2,269,723 and the like have been proposed, but these proposals still have problems in weather resistance, water resistance and the like, and are not yet satisfactory when practically implemented.

[0003]

DISCLOSURE OF THE INVENTION In order to solve the above problems, the present invention has conducted extensive studies and as a result, 1 to 30 weight parts of an aqueous polyurethane resin and a bisphenol type epoxy compound having one or more epoxy groups in one molecule have been added. Part (solid content conversion)
By containing the product obtained by reacting in a proportion of 1, the yellowing resistant type epoxy-modified aqueous polyurethane resin composition was found to have excellent weather resistance and water resistance, and the present invention was completed.

[0004]

[Means for Solving the Problems] That is, the present invention relates to an aqueous polyurethane resin having a carboxyl group with 1 to 30 parts by weight of a bisphenol type epoxy compound having one or more epoxy groups in one molecule (solid content conversion). The present invention relates to a non-yellowing type epoxy-modified waterborne polyurethane resin composition containing a product obtained by reacting in a ratio of 1).

The yellowing-resistant type epoxy-modified aqueous polyurethane resin used in the present invention is produced, for example, as follows. First, it is obtained by reacting the following compounds of aliphatic, aromatic or alicyclic isocyanates with the following polyols having a carboxyl group and bisphenol type epoxy compounds having one or more polyol and epoxy groups in one molecule. The urethane prepolymer containing a carboxyl group having two or more isocyanate groups at the end is used.
In the above reaction, the ratio of isocyanates to polyols and polyols having a carboxyl group and bisphenol type compounds having one or more epoxy groups in one molecule is the isocyanate group content of the prepolymer (converted to solid content). Is 0.5% to 10%, preferably 1% to
Adjust to be 4%. If the isocyanate group content is 0.5% or less, the molecular weight does not easily become sufficiently large in the chain extension reaction, and if it is 10% or less, the carbon dioxide amount is too large in the chain extension reaction, and production is difficult. Further, in the above reaction, the amount of the polyol having a carboxyl group is set to be 10 or more, preferably 15 or more as an acid value (solid content conversion). The above-mentioned urethane prepolymer containing a carboxyl group can be produced by the same method as that for a so-called urethane prepolymer which is usually used for producing a polyurethane resin.

Examples of the above-mentioned isocyanate compounds include toluylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthene diisocyanate, diphenylmethylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 4,4-
One or a mixture of two or more of aromatic diisocyanates such as dibenzyl diisocyanate and 1,3-phenylene diisocyanate, or a polyisocyanate compound that is an adduct with water is used.

Any of the above-mentioned carboxyl group-containing polyols can be used as long as it imparts a branched carboxyl group to the linear prepolymer molecule, but in order to increase the carboxyl content in the prepolymer, , Having 3 to 10 carbon atoms having at least one branched carboxyl group
Of low molecular weight are preferred, for example, 2,2-dimethylolpropionic acid is preferred.

As the polyols used in the present invention, known polyols usually used in the production of urethane resins, for example, diethylene glycol, butanediol, hexanediol, neopentyl glycol, bisphenol A, cyclohexanedimethanol. , Trimethylolpropane, glycerin, pentaerythritol, polyethylene glycol, polypropylene glycol, polyester polyol, polycaprolactone, polytetramethylene ether glycol, polythioether polyol, polyacetal polyol, polybutadiene polyol, and the like, or a mixture of two or more thereof. .. These polyols can be appropriately selected according to the purpose and application, and the required physical properties such as hardness and softness can be easily designed.

As the bisphenol type epoxy compound used in the present invention, the following commercially available products can be used. For example, Epicoat 828, Epicoat 1001,
It is easily available as Epicoat 1002, Epicoat 1004, Epicoat 1007, Epicoat 1009 (manufactured by Shell Kagaku) and the like. It is desirable that the bisphenol type epoxy compound is contained in an amount of 1 to 30 parts by weight (as solid content).

The refractory yellowing-type aqueous polyurethane resin used in the present invention is prepared by dissolving or suspending a mixture of the above-mentioned urethane prepolymer containing a carboxyl group and the above bisphenol type epoxy compound in the following solvent and / or water.
A basic organic compound (which reacts with a carboxyl group to increase hydrophilicity) and the following extender are added dropwise, or the basic organic compound and the extender are dissolved in a solvent and / or water to prepare a urethane prepolymer solution. By making the carboxyl group-containing urethane prepolymer hydrophilic by a method such as dripping, and at the same time reacting with the extender, it is diluted with an appropriate amount of water, and the concentration of the non-volatile matter is 30 to 40 under reduced pressure.
%, Dehydration and desolvation are performed at 70-80 ° C for about 6%.
A yellowing resistant epoxy-modified waterborne polyurethane resin is obtained by performing the reaction for a time.

The extender used in the present invention is water,
Or diamines are suitable, and as polyamines,
For example, ethylenediamine, diethylenetriamine, triethylenetetramine, propylenediamine, butylenediamine, hexamethylenediamine, cyclohexylenediamine, piperazine, 2-methylpiperazine, phenylenediamine, tolylenediamine, xylenediamine,
α, α-methylenebis (2-chloroaniline) 3,3-
Dichloro-α, α-biphenyldiamine, 2,6-diaminopyridine, α, α-diaminodiphenylmethane, m
-Xylenediamine, isophoronediamine, N-methyl-3,3-diaminopropylamine, and an adduct of diethylenetriamine and an acrylate or a hydrolysis product thereof. Further, as the basic organic compound for reacting with the carboxyl group to impart hydrophilicity, any known one can be used, but particularly preferable examples include dimethylethanolamine, diethylethanolamine, triethylamine and the like. ..

The solvent used in the production includes methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, toluene, xylene, isobutyl acetate, butyl acetate, acetone, dimethylformamide, N-methyl-
2-Pyrrolidone, diethylene glycol dimethyl ether and the like are suitable. The yellowing-resistant type epoxy-modified aqueous polyurethane resin used in the present invention, if necessary, an organic solvent, a pigment, a dye, an emulsifier, a surfactant, a leveling agent,
Defoamer, thickener, heat stabilizer, filler, anti-settling agent, UV
It may also contain other conventional ingredients such as absorbents, antioxidants, thickeners and the like. Further, the yellowing-resistant type epoxy-modified aqueous polyurethane resin composition obtained in the present invention can be used for blending with an acrylic emulsion, a rubber emulsion, or other water-based resin. Further, the yellowing resistant type epoxy modified aqueous polyurethane resin composition obtained in the present invention and acrylic acid, acrylic acid ester, methacrylic acid,
Urethane copolymer resin copolymerized with at least one vinyl monomer such as vinyl chloride, styrene, acrylonitrile, vinyl acetate, etc., and hybridization of the vinyl monomer with a yellowing-resistant epoxy-modified aqueous polyurethane resin composition Of course, you can also improve performance.

[0013]

EXAMPLES In order to more specifically describe the present invention,
The present invention is not limited to these examples, although the description will be given with reference to comparative examples and examples.

Example 1 In a 2000 ml four-necked flask equipped with a thermometer, a stirrer and a nitrogen inlet tube, 83.7 g of polytetramethylene ether glycol having a molecular weight of 2000, 51.6 g of neopentyl glycol and 4.2 g of trimethylolpropane were placed. , Dimethylolpropionic acid 21.5 g, Epicoat 1001
(Manufactured by Shell Chemical Co., Ltd.) 52.9 g and N-methyl-2-pyrrolidone 34.4 g are charged, and 90 ° C. while introducing nitrogen.
The temperature was raised to, and the contents were dissolved. Next, the mixture was cooled to 30 ° C., 86 g of acetone was added, and 139.0 g of tolylene diisocyanate was added dropwise over 1 hour. Internal temperature is 30 ~
After keeping the temperature at 40 ° C. for 8 hours, the mixture was diluted with 86 g of acetone. The NCO group content of this prepolymer is
It was 0.60%. Dimethyl ethanolamine 12.
481.5 g of deionized water containing 1 g was maintained at 60 ° C., 506.4 g of the above prepolymer was added dropwise over 1 hour, and further, the internal temperature was 70 to 70 ° C. after decompression deacetone at 50 ° C.
The reaction was carried out for 8 hours while maintaining the temperature at 80 ° C., and finally, the non-volatile content was 39.0%, the pH was 8.9, the viscosity was 450.0 cps / 25.
A yellowing-resistant type epoxy-modified aqueous polyurethane resin having a temperature change of ℃ was obtained.

Example 2 In a 2000 ml four-necked flask equipped with a thermometer, a stirrer and a nitrogen inlet tube, 83.7 g of polycaprolactone having a molecular weight of 2000, 51.6 g of neopentylglycol, 4.2 g of trimethylolpropane, and Dimethylo | Lpropionic acid 21.5 g, Epicoat 1001 (manufactured by Shell Kagaku) 6
3.5 g and 34.4 g of N-methyl-2-pyrrolidone were charged, the temperature was raised to 90 ° C. while introducing nitrogen, and the contents were dissolved. Then, the mixture was cooled to 30 ° C., 86 g of acetone was added, and 139.0 g of tolylene diisocyanate was added to 1
It dripped over time. After maintaining the internal temperature at 30 to 40 ° C. and performing the reaction for 8 hours, the mixture was diluted with 86 g of acetone. The NCO group content of the obtained prepolymer was 0.51%. 481.5 g of deionized water containing 12.1 g of dimethylethanolamine was maintained at 60 ° C., and 517.0 g of the above prepolymer was added dropwise over 1 hour.
After degassing acetone under reduced pressure at ℃, keep the internal temperature at 70 ~ 80 ℃,
Time reaction, finally non-volatile content 40.0%, PH
A yellowing resistant epoxy-modified aqueous polyurethane resin having a viscosity of 9.0 and a viscosity of 880 cps / 25 ° C. was obtained.

Example 3 In a 2000 ml four-necked flask equipped with a thermometer, a stirrer and a nitrogen inlet tube, 83.7 g of polypropylene glycol having a molecular weight, 51.6 g of neopentyl glycol and 4.2 g of trimethylolpropane were added. 21.5 g of methylol propionic acid, 45.0 g of Epikote 1002 (manufactured by Shell Kagaku), 3 of N-methyl-2-pyrrolidone
4.4 g was charged and the temperature was raised to 90 ° C. while introducing nitrogen to dissolve the contents. Then cool to 30 ° C, 86 g
Of acetone was added, and tolylene diisocyanate 139.
0 g was added dropwise over 1 hour. After maintaining the internal temperature at 30 to 40 ° C. and performing the reaction for 8 hours, the mixture was diluted with 86 g of acetone. The obtained NCO group content was 0.48%.
481.5 g of deionized water containing 12.1 g of dimethylethanolamine was maintained at 60 ° C., 498.5 g of the above prepolymer was added dropwise over 1 hour, and further, the internal temperature was reduced to 70 ° C. after depressurizing deacetone at 50 ° C. The reaction was carried out for 8 hours while maintaining the temperature at -80 ° C, and finally the nonvolatile content was 40.1% and PH9.
1. A yellowing resistant epoxy-modified aqueous polyurethane resin having a viscosity of 980 cps / 25 ° C. was obtained.

Comparative Example 1 In a 2000 ml four-necked flask equipped with a thermometer, a stirrer and a nitrogen inlet tube, 83.7 g of a polytetramethylene ether glycol having a molecular weight of 2000, 51.6 g of neopentyl glycol and 4.2 g of trimethylolpropane were placed. , Dimethylolpropionic acid 21.5 g, N-methyl-2-pyrrolidone 34.4 g were charged, and while introducing nitrogen, 90
The temperature was raised to ° C and the contents were dissolved. Next, the mixture was cooled to 30 ° C., 86.0 g of acetone was added, and 139.0 g of tolylene diisocyanate was added dropwise over 1 hour. Internal temperature 3
After keeping the temperature at 0 to 40 ° C. and performing the reaction for 8 hours, it was diluted with 86 g of acetone. The obtained NCO group content was 0.9.
It was 0%. 481.5 g of deionized water containing 12.1 g of dimethylethanolamine was maintained at 60 ° C., and 506.4 g of the above prepolymer was added dropwise over 1 hour to react to obtain an aqueous polyurethane resin. Furthermore,
This aqueous polyurethane resin was subjected to deacetone decompression under reduced pressure at 40 ° C. to finally obtain a nonvolatile content of 38.2%, PH 7.6,
An aqueous polyurethane resin having a viscosity of 400 cps / 25 ° C. was obtained.

Comparative Example 2 In a 2000 ml four-necked flask equipped with a thermometer, a stirrer and a nitrogen inlet tube, 83.7 g of polycaprolactone having a molecular weight of 2000, 51.6 g of neopentyl glycol, 4.2 g of trimethylolpropane, and di 21.5 g of methylolpropionic acid, 34.4 N-methyl-2-pyrrolidone
After charging g, the temperature was raised to 90 ° C. while introducing nitrogen to dissolve the contents. Then, the mixture was cooled to 30 ° C., 86.0 g of acetone was added, and tolylene diisocyanate 139.0 was added.
g over a period of 1 hour, keeping the internal temperature at 30-40 ° C,
After reacting for 8 hours, it was diluted with 86.0 g of that acetone. The NCO group content of this prepolymer is 0.90.
%Met. 481.5 g of deionized water containing 12.1 g of dimethylethanolamine was maintained at 60 ° C., and 506.4 g of the above prepolymer was added dropwise over 1 hour to react to obtain an aqueous polyurethane resin. Further, this aqueous polyurethane resin was subjected to deacetone decompression under reduced pressure at 40 ° C. to finally obtain a nonvolatile content of 38.0%, a pH of 7.6, and a viscosity of 6.
An aqueous polyurethane resin of 60 cps / 25 ° C was obtained.

A baking-type acrylic white enamel is applied to the yellowing resistant type epoxy-modified aqueous polyurethane resin compositions containing the bisphenol type epoxy compounds of Examples 1 to 3 and the aqueous polyurethane resin compositions of Comparative Examples 1 and 2. The coated MIGAKI mild steel plate (JIS G3141) was coated with a bar coater so as to have a thickness of 10 microns after drying. The coating
It was dried for 1 day in a constant temperature and constant humidity chamber at a temperature of 20 ° C. and a humidity of 60% and subjected to a performance test. The test method was according to JIS K 5400.

[0020]

[Table 1] Test method and evaluation criteria Boiling water resistance: Immersed in boiling water for 4 hours and observing whitening state XX: Whitening (no transparency at all) ◎: No whitening Weather resistance: Weatherometer after 100, 200 hours
E & gloss measurement

[0021]

EFFECTS OF THE INVENTION It is clear from Table 1 that the yellowing resistant type epoxy modified waterborne polyurethane resin composition obtained in the present invention is excellent in boiling water resistance and weather resistance.

Claims (5)

[Claims] 1. An aqueous polyurethane resin having a carboxyl group in the molecule, and 1 to 30 parts by weight of a bisphenol type epoxy compound having one or more epoxy groups in one molecule (100 parts by weight of the aqueous polyurethane resin). A non-yellowing type epoxy-modified aqueous polyurethane resin composition containing a product obtained by reacting at a ratio of solid content). 2. The aqueous polyurethane resin first reacts with an isocyanate compound, a polyol and a bisphenol type epoxy compound having one or more epoxy groups in one molecule and a polyol having a carboxyl group to give an isocyanate group content ( 0.5% to 10 (solid content conversion)
% Of a carboxyl group-containing urethane prepolymer having two or more isocyanate groups at the ends, and then charging the urethane prepolymer into deionized water mixed with a basic organic compound and an extender. , An aqueous polyurethane obtained by imparting hydrophilicity to a urethane prepolymer containing a carboxyl group and an epoxy group and at the same time reacting with an extender, and then obtained by reacting a carboxyl group with an epoxy group. The yellowing-resistant type epoxy-modified aqueous polyurethane resin composition according to claim 1, which has a concentration of 30 to 40%. 3. A carboxyl group-containing polyol is
The non-yellowing type epoxy-modified water-based polyurethane resin composition according to claim 2, which is a branched low molecular weight one having 3 to 10 carbon atoms and having at least one carboxyl group. 4. The non-yellowing type epoxy-modified aqueous polyurethane resin composition according to claim 2, wherein the basic organic compound is dimethylethanolamine or diethanolaminetriethylamine. 5. The non-yellowing type epoxy-modified aqueous polyurethane resin composition according to claim 1, wherein the extender is water or polyamines.