JPH107902A - Resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a smooth surface without volume shrinkage by obtaining fluidity, applicability, and polishing after applying a putty agent without applying a large amount of a putty agent to a defective portion. . SOLUTION: In an aqueous urethane resin having an anionized carboxyl group and a double bond, the equivalent ratio of the epoxy group to the anionized carboxyl group is 0.02 to 0.7, and the molecular weight is 70 to 70. 4,0
A resin composition comprising an aqueous urethane resin having an anionized carboxyl group and a double bond, a water-soluble polymer compound, and a thermally expandable filler obtained by performing a cross-linking reaction with an epoxy compound of No. 00.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a putty resin composition for repairing small irregularities on the surface of plywood to a uniform surface. More specifically, to obtain a bubble-containing coating film having a smooth surface without volumetric shrinkage excellent in economical efficiency, fluidity, applicability,
The present invention relates to a putty resin composition having excellent polishing properties after the application of the putty agent.

[0002]

2. Description of the Related Art Conventionally, repair of plywood or particle board (hereinafter referred to as a wood material) has been performed by a method of artificially filling a defective portion with a plywood putty. However, as the quality of raw wood, which is a raw material of plywood, is reduced year by year, it has become difficult to repair the defective portion artificially. Therefore, the present inventors have applied a resin composition (Japanese Patent Application No. 3-251125,
Japanese Patent Application No. 3-281266 and Japanese Patent Application No. 3-2860.
No. 92), the entire surface of the plywood was repaired by the coating method described in Japanese Patent Application Nos. 3-184263 and 3-273906. It has been found that an improved plywood with excellent surface smoothness is obtained.

[0003]

However, in the above-mentioned method, plywood having excellent surface smoothness corresponding to volume shrinkage of small defects of 5 mm or less of wood material can be obtained, but plywood of large defects has There is a problem that a smooth surface cannot be obtained due to generation of eye flaws. In other words, it is necessary to apply a heat-expanding putty agent corresponding to the volume shrinkage even in a large defect portion, and to optimize the defect portion so as not to cause eye damage.

[0004]

DISCLOSURE OF THE INVENTION In view of the above circumstances, the present inventors have considered the equivalent ratio of the epoxy group of the anionized carboxyl group and the anionized carboxyl group of the aqueous urethane resin having a double bond and the epoxy compound. By specifying the molecular weight of
Further improvement was found by using a heat-expandable filler in the putty described in JP-A-318944), and the present invention was completed.

That is, the present invention relates to an aqueous urethane resin having an anionized carboxyl group and a double bond, wherein the equivalent ratio of the epoxy group to the anionized carboxyl group is 0.02 to 0.7, and the molecular weight is Is 7
The present invention relates to a resin composition comprising an aqueous urethane resin having an anionized carboxyl group and a double bond, a water-soluble polymer compound, and a heat-expandable filler obtained by performing a crosslinking reaction with 0 to 4,000 epoxy compounds.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The equivalent ratio of the epoxy group to the carboxyl group in the aqueous urethane resin having an anionized carboxyl group and double bond of the present invention is 0.02 to 0.7, and more preferably a ratio of 0.2 to 0.35. It is. When the equivalent ratio of the epoxy groups is less than 0.02, the drying property is reduced. On the other hand, if it exceeds 0.7, coarse particles are generated, and production becomes difficult.

The epoxy compound has a molecular weight of 70 to 4,000.
0 is used. If the molecular weight of the epoxy compound is less than 70,
Low crosslink density and poor hardness. In addition, the molecular weight is 4,000
If it exceeds 0, an organic solvent must be used for solidification, the workability is poor, and there is a problem in terms of environmental hygiene. The following epoxy compounds can be used.
For example, epicoat 1001, epicoat 1002, epicoat 1004, epicoat 1007, epicoat 1
009, Epicoat 828, Epicoat 152, Epicoat 154 (trade names, manufactured by Shell Chemical Co., Ltd.), Epolite 400E, Epolite 200E, Epolite 40E, Epolite 80MF (trade names, manufactured by Kyoeisha Yushi Kagaku Kogyo KK), and Denacol EX810, 811 , 851,
830, 832, 841, 861, 911, 941, 9
20, 921, 931, 211, 212, 221, 72
1, 313, 314, 321, 421, 512, 52
1, 611, 612, 614, 614B, 622 (trade name of Nagase Kasei Kogyo Co., Ltd.) and the like are preferable.

As the water-soluble polymer compound used in the present invention, polyvinyl alcohol, carboxymethylcellulose, hydroxyethylcellulose, methylcellulose and the like are used, and they may be used alone or as a mixture.

The ratio of the water-soluble polymer compound to the aqueous urethane resin is from 50 to 200 per 100% by weight of the solid content.
% By weight, more preferably from 70 to 70% by weight.
130% by weight is preferred. If the addition amount is less than 50% by weight, uniform coating cannot be performed, which is not preferable. On the other hand, if the content exceeds 200% by weight, the water resistance of the filled defective portion is undesirably reduced.

[0010] The thermally expandable filler used in the present invention refers to a filler having a property of expanding when heated.
A product having a particle size of 5 to 30 μm obtained by enclosing vinylidene chloride / acrylonitrile copolymer as a shell and isobutane as a foaming agent.
The particle size becomes μm. The heat-expandable filler is a commercially available one produced industrially, and preferably has a thermal decomposition temperature of 60 ° C. or higher, more preferably 80 ° C. or higher. If the temperature is lower than 60 ° C., the aging stability under high temperature is deteriorated. The heat-expandable filler is preferably added in an amount of 0.01 to 10% by weight, more preferably 0.1 to 5% by weight, based on 100% by weight of the solid content of the aqueous urethane resin and the water-soluble polymer compound. . If the added amount is less than 0.01% by weight, the volume expansion at the time of thermal decomposition is small, so that the smoothness effect is small, which is not preferable. If the added amount exceeds 10% by weight, there are problems such as excessive expansion and return to cavitation. And is not economically preferable.

The heat-expandable fillers used herein include microspheres F-20, F-30, F-30 made by Matsumoto Yushi.
50 or Expansal 642 manufactured by Kessnode. In using the heat-expandable filler used in the present invention, the solid content of the resin composition excluding the heat-expandable filler is preferably 70% by weight or more. If it is less than 70% by weight, cavitation occurs due to evaporation of water and decomposition of the thermally expandable filler during heating, which is not preferable. Inorganic and organic fillers may be used as needed. Examples of the inorganic filler include powders of titanium oxide, calcium carbonate, talc, clay, kaolin, bentonite, and the like, and examples of the organic filler include wood flour, coconut cell flour, and the like, but are not limited thereto. Not a thing.

Next, an example of a method for producing an aqueous urethane resin having an anionized carboxyl group and a double bond used in the present invention will be described. That is, the aqueous urethane resin reacts a polyisocyanate with a diol having a carboxyl group, a polyol or an oil-and-fat and a polyhydric alcohol, and a urethane prepolymer having a terminal isocyanate group having a carboxyl group and a double bond. The urethane prepolymer is dropped into deionized water containing a basic organic compound and an extender, and a carboxyl anionized by performing ion addition by a chain extension reaction and a neutralization reaction of the carboxyl group. An aqueous urethane resin having groups and double bonds is obtained.

The urethane prepolymer of the above reaction has an isocyanate group content (in terms of solid content) of 0.5 to 10% by weight.
And more preferably 0.8 to 4% by weight. If the isocyanate group content is less than 0.5% by weight, the molecular weight does not become sufficiently large in the chain extension reaction, which is not preferable. If it exceeds 10% by weight, the amount of carbon dioxide gas generated in the chain extension reaction is too large, which is not preferred. .

In the above reaction, the amount of the diol having a carboxyl group is 1 as an acid value (in terms of solid content).
It is set to be 0 or more, preferably 15 or more. If the acid value is less than 10, self-emulsification is difficult, the particle size becomes large, and stability is lacking. The above-mentioned urethane prepolymer can be produced by a known method exactly the same as that of a so-called urethane prepolymer usually used for producing a polyurethane resin.

As the compound having an isocyanate group, for example, 1-tetramethylene diisocyanate,
1,6-hexamethylene diisocyanate, 2,2,4
-Trimethylhexamethylene diisocyanate, 2,8
Aliphatic isocyanates such as diisocyanatemethylcaproate, 3-isocyanatomethyl-3,5,5
Alicyclic diisocyanates such as methyl cyclohexyl isocyanate, methylcyclohexyl-2,4-diisocyanate, toluylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthene diisocyanate, diphenylmethylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate,
Aromatic diisocyanates such as 4,4-dibenzyl diisocyanate and 1,3-phenylene diisocyanate,
1 such as chlorinated diisocyanates, brominated diisocyanates, and polyisocyanate compounds which are adducts of water;
A species or a mixture of two or more species is used.

The carboxyl group-containing diol includes
Any type can be used as long as it has a branched carboxyl group in the linear prepolymer molecule. However, in order to increase the carboxyl group content in the prepolymer, at least one branched carboxyl group is required. Having 3 or more carbon atoms
A low molecular weight diol of 10 is preferred, e.g.
-Dimethylolpropionic acid is preferred.

As the polyol used in the present invention, known polyols usually used for producing 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,
Examples thereof include one or a mixture of two or more of polyacetal polyol, polybutadiene polyol, and furandmethanol. These polyols can be appropriately selected according to the purpose and application, and necessary physical properties such as hard and soft can be easily designed.

The polyol which is used in the present invention and is obtained by esterifying an oil or fat with a polyhydric alcohol has an iodine value of 7 or less.
And oil-fat and polyhydric alcohols such as trimethylolpropane and pentaerythritol, which are umesterified, and are XP1076E, XP1077E, and XP158.
Commercially available products such as 0E and FB20-50XB (manufactured by Mitsui Toatsu Chemicals, Inc.) can be used.

In the production of the aqueous urethane resin used in the present invention, the urethane prepolymer is prepared by using a solvent and / or
Alternatively, dissolve or suspend in water and react with a carboxyl group to add a basic compound and the following extender for increasing hydrophilicity, or dissolve the basic compound and the extender in a solvent and / or water. Then, the urethane prepolymer is made hydrophilic by, for example, dropping a urethane prepolymer solution, and then reacting with an elongating agent. Then, dehydration and dehydration are performed until the concentration of non-volatile components becomes 30 to 45%. And / or desolvation and further 70
Reaction at ~ 90 ° C for about 6 hours, reaction rate is 50-100%
The reaction is carried out by reacting a carboxyl group and an epoxy group until the reaction becomes.

Suitable extenders used in the present invention are, for example, water and polyamines. Examples of the polyamines include ethylenediamine, diethylenetriamine, triethylenetetramine, propylenediamine, butylenediamine, hexamethylenediamine, and the like. Cyclohexylenediamine, piperazine, 2-methylpiperazine, phenylenediamine, tolylenediamine, xylenediamine, α, α′-methylenebis (2-chloroaniline) 3,3′-dichloro-α, α′-biphenylamine, m- Xylene diamine, isophorone diamine, N
Adducts of -methyl-3,3'-diaminopropylamine and diethylenetriamine with acrylates or hydrolysis products thereof. As the basic organic compound for imparting hydrophilicity by reacting with a carboxyl group, any known basic organic compound can be used, and particularly preferred examples include dimethylethanolamine, diethylmethanolamine, and triethylamine.

The curing accelerator used in the present invention includes:
Known materials which are usually used as a curing accelerator for unsaturated resins can be used. For example, cobalt naphthenate, calcium naphthenate, lithium naphthenate, manganese naphthenate, lead naphthenate, zinc naphthenate, copper naphthenate, zirconium naphthenate, cobalt octylate, calcium octylate, manganese octylate, copper octylate, Lead octylate, zinc octylate, zirconium octylate, aluminum octylate, stannous octylate,
Water-soluble cobalt and water-soluble curing accelerators include W
—O cobalt, WO manganese, W-cobalt, W-lead (manufactured by Toei Kako Co., Ltd.), and DICATATE 3111 (manufactured by Dainippon Ink and Chemicals, Inc., trade name). The above-mentioned curing accelerator is usually used in the range of 0.005 to 0.2% by weight, preferably 0.03 to 0.15% by weight as a metal component based on the solid content of the aqueous urethane resin.

Examples of the solvent used in the present invention include 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. .

The aqueous urethane resin used in the present invention comprises:
If necessary, organic solvents, pigments, dyes, emulsifiers, surfactants, thickeners, heat stabilizers, leveling agents, defoamers, fillers, anti-settling agents, UV absorbers, antioxidants, thickeners, etc. It may contain other conventional components. Using the low-temperature curing type aqueous resin composition of the present invention, acrylic emulsion,
Blends with rubber-based emulsions and other water-based resins can also be used.

A low-temperature-curable aqueous resin composition and acrylic acid,
An aqueous urethane-based copolymer resin composition can be obtained by copolymerizing with at least one kind of vinyl monomer such as methacrylate, vinyl chloride, styrene, acrylonitrile, and vinyl acetate. Hybridization of the union and the aqueous urethane resin composition can also be performed, thereby improving the performance.

Based on the aqueous urethane resin obtained in this manner, a resin composition of a putty agent for repairing the uneven surface of the plywood to a uniform surface with a low coating amount is obtained. In order to achieve uniform and smooth foaming, foam stabilizers are often used. As these foam stabilizers, silicones are mainly used, and 0.05 to 3.0% by weight based on the resin composition.
It is desirable to add and adjust the size, the amount of foaming, and the foaming state of foaming foam. The antifoaming agent has the same function as the antifoaming agent, and the amount of the antifoaming agent is determined in consideration of the antifoaming agent, since the antifoaming agent is usually added to the aqueous urethane resin. It is necessary. In the case where the foam state of the coating film is sufficiently controlled by the defoaming agent in the aqueous urethane resin, the foaming agent need not be blended.

When a foam stabilizer or an antifoaming agent is blended in the resin composition, the generated bubbles are more uniformly foamed and adjusted. Air bubbles are generated in the entire coating film in the foamed coating film, but the formation, amount, growth rate, etc. of the air bubbles differ depending on the type, amount, foam stabilizer, etc. of the aqueous urethane resin and the foaming agent. Determined.

The pigment used in the resin composition includes, but is not limited to, powders of titanium dioxide, calcium carbonate, talc, clay, bentonite, and kaolin.

Usually, the resin composition is immediately applied by a usual application means such as a roll or a knife coater. However, a more preferable result can be obtained by applying the resin composition by the method previously applied (Japanese Patent Application No. 3-184263). can get.

The resin composition thus obtained is applied to a woody material such as plywood and particle board to improve fluidity, applicability, abrasion after applying a putty agent, and obtain a coating film containing bubbles to obtain a volume. A smooth surface without shrinkage can be obtained. Moreover, it can be finished smoothly with a coating material without "eyelash", "twist" and "warpage", and has good sanding suitability and economical secondary processing. Preferred as a woody material.

[0030]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. In Examples and Comparative Examples,% represents% by weight. Production Example 1 (Synthesis of urethane prepolymer) XP1077 was placed in a 2 L four-necked flask equipped with a thermometer, a stirrer, and a nitrogen inlet tube.
E (trade name, um-esterified polyol of linseed oil and pentaerythritol manufactured by Mitsui Toatsu Chemicals, Inc., molecular weight 6
38, 115.4 g of iodinated 133), molecular weight 200
Of polytetramethylene ether glycol of 71.2
g, 5.8 g of trimethylolpropane, 21.5 g of dimethylolpropionic acid, and 34.4 g of N-methyl-2-pyrrolidone, and the temperature was raised to 90 ° C. while introducing nitrogen to dissolve the contents. Next, cool to 40 ° C.
6.5 g of acetone was added, and when the internal temperature reached 30 ° C., 86.2 g of tolylene diisocyanate 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 86.5 g of acetone. The NCO group content of this urethane prepolymer was 0.9%. Further, as an epoxy compound, Epicoat 1001
1.5 g of (trade name, manufactured by Shell Chemical Co., Ltd., molecular weight: 900, epoxy equivalent: 450) was added to prepare a urethane prepolymer mixed with an epoxy compound.

Production Example 2 (Synthesis of aqueous dispersion of urethane prepolymer) To the urethane prepolymer obtained in Production Example 1, 485 g of deionized water containing 12.1 g of dimethylethanolamine was added to 40 parts of the urethane prepolymer.
℃, urethane prepolymer mixed with the above epoxy compound was added dropwise, and after decompression in acetone at 40 ℃, the internal temperature was kept at 70 ℃, and ionization of carboxyl groups and chain extension of NCO groups were taken for 6 hours. Then, acetone was removed under reduced pressure at 40 ° C., and the nonvolatile content was 39.0% and the viscosity was 650.
cps / 25 ° C., pH 7.7, acid value 30.0 KOHmg
/ G (solid content conversion) of an aqueous urethane resin dispersion mixed with an epoxy compound.

Production Example 3 (Synthesis of Aqueous Urethane Resin A) The aqueous urethane resin dispersion obtained by mixing the urethane prepolymer obtained in Production Example 2 with an epoxy compound was maintained at 70 ° C. Epoxy group to the group in an equivalent ratio of 0.03
20.0 g of DICATATE 3111 (trade name, water-soluble cobalt naphthenate manufactured by Dainippon Ink and Chemicals, Inc.) as a curing accelerator for double bonds.
To a final non-volatile content of 39%, pH 8.6, and a viscosity of 5.
An aqueous urethane resin A was obtained at 50 cps / 25 ° C. and an acid value of 29.0 KOH mg / g (solid content).

Production Example 4 (Synthesis of Aqueous Urethane Resin B) Under the same conditions as for the production of the aqueous urethane resin A, 15.8 g of Epicoat 1001 was added, and the epoxy group to carboxyl group was added in an equivalent ratio of 0.1.
Reaction at a rate of 219, non-volatile content 40.0%, pH
8.9, viscosity 500 cps / 25 ° C., acid value 23.4 KO
A low-temperature-curable aqueous resin composition of Hmg / g (in terms of solid content) was obtained, and was designated as an aqueous urethane resin B.

Production Example 5 (Synthesis of aqueous urethane resin C) Epicoat 1 of Production Example 4
001 was set to 1.0 g, and an epoxy group was reacted at an equivalent ratio of 0.014 to a carboxyl group, except that
Performed in the same manner as in Production Example 3. As a result, the nonvolatile content was 39.3.
%, Viscosity 450 cps / 25 ° C., pH 8.8, acid value 2
A low-temperature-curable aqueous resin composition of 4.4 KOH mg / g (in terms of solid content) was obtained and used as an aqueous urethane resin C.

Production Example 6 (Preparation of aqueous solution of water-soluble polymer) Polyvinyl alcohol 2
Water was added to 03 (Kuraray Co., Ltd.) and heated and dissolved at 80 ° C. to obtain a 20% aqueous solution.

Examples 1-4 Using the aqueous urethane resins A and B obtained in Production Examples 3 and 4, an aqueous solution of a water-soluble polymer, and F-20 (Matsumoto Yushi) and Expanyal 642 as a thermally expandable filler, The putty agent was evaluated using the composition shown in Table 1. Table 1 shows the evaluation results.

Comparative Examples 1-3 Using the aqueous urethane resins A and C obtained in Production Examples 3 and 5, putty agents were evaluated with the composition shown in Table 1. Table 1 shows the evaluation results.

[0038]

[Table 1] ◎: very good, ：: good, Δ: slightly eye-spotting, ×: eye-spot large

The evaluation was performed as follows. Each putty composition is applied to a 2.5 mm plywood for testing (a back plate usually used as a plywood is also used for the front side and has defects such as cracks and pinholes) using a knife coater over the entire surface of the 12 mm plywood. After that, it is 120-150 ° C with a jet hot air dryer.
For 45 seconds to deposit. After deposition for 4 hours, 3 heads (sandpaper # 120, # 150, # 180)
Grinding with a wide belt sander. The measurement items are as follows. 1) Filling property after application: The presence or absence of filling raised on a defective portion is visually checked. 2) Drying property: The drying property of the coated surface after drying is determined by touch with a finger. 3) Grindability: Clogging of sandpaper during sanding is visually confirmed. 4) Fillability of the product: The presence or absence of thinning of the defective portion after sanding is visually checked.

[0040]

According to the present invention, it is possible to achieve the present technology in which smoothness can be obtained even at a large defect portion of a woody material, which has not been achieved by the conventional technology, without causing any loss in the size. That is, in the comparative examples which are out of the scope of the present invention, the purpose of these phenomena was not achieved, and the large defect portion was frayed.
However, in Examples within the scope of the present invention, the putty resin composition using a water-soluble polymer compound and a heat-expandable filler in the aqueous urethane resin is economical and applicable without impairing the filling property. , Drying property and grinding property, all of these phenomena could be satisfied.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Nobuhiko Koto 7-1-1, Hikoshimasako-cho, Shimonoseki-shi, Yamaguchi Pref.

Claims (8)

[Claims] 1. An aqueous urethane resin having an anionized carboxyl group and a double bond, wherein the equivalent ratio of the epoxy group to the anionized carboxyl group is 0.02 to 0.7 and the molecular weight is 70. ~ 4,0
A resin composition comprising an aqueous urethane resin having an anionized carboxyl group and a double bond, a water-soluble polymer compound, and a thermally expandable filler obtained by performing a cross-linking reaction with an epoxy compound of No. 00. 2. An aqueous urethane resin reacts a polyisocyanate with a diol, a polyol having a carboxyl group, a polyol esterified with an oil or fat and a polyhydric alcohol, and a polyisocyanate to form a terminal isocyanate group having a carboxyl group and a double bond. The urethane prepolymer is allowed to react, the urethane prepolymer is dropped into deionized water containing a basic organic compound and an extender, and anionization is performed by performing ion addition by a chain extension reaction and a carboxyl group neutralization reaction. The resin composition according to claim 1, which is an aqueous urethane resin having a carboxyl group and a double bond. 3. The resin composition according to claim 1, wherein the water-soluble polymer compound is selected from the group consisting of polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl alcohol, and methyl cellulose. 4. The heat-expandable filler has a decomposition temperature of 60 ° C.
The resin composition according to claim 1, which is selected from the above. 5. The resin composition according to claim 1, wherein the solid content of the resin composition is 70% by weight or more. 6. A diol having a carboxyl group,
3. The resin composition according to claim 2, which is 2,2-dimethylolpropionic acid. 7. The resin composition according to claim 2, wherein the iodination of the fat or oil is from 7 to 200. 8. The resin composition according to claim 2, wherein the urethane prepolymer having a terminal isocyanate group has an isocyanate group content of 0.5 to 10% by weight in terms of solid content.