JPH0232183A - Adhesive composition - Google Patents

Abstract

PURPOSE:To obtain an adhesive composition for decorative processing of sliced veneer, consisting of a rubber latex and aminoethylated compound of an acidified aminoethylated vinyl interpolymer and excellent in resistance to cracks by drying and exudation fouling on the surface of the sliced veneer with water and heat resistance. CONSTITUTION:The objective composition consisting of (A) a synthetic rubber latex and (B) an interpolymer, prepared by reacting an interpolymer having >=3wt.% groups -COOH in the side chain with an acid and aminoethylating the resultant acidified aminoethylated vinyl interpolymer and having aminoethyl groups expressed by the formula (R and R' are H or 1-4C alkyl; n is average 1.0-2.5) in the side chain. Furthermore, the weight ratio of the components (A) to (B) is 100/(0.1-100) [especially preferably 100/(1-50)] expressed in terms of solids.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an adhesive composition, and particularly to an adhesive for decorative processing of veneer.

More specifically, the present invention relates to an adhesive for decorative veneer processing that has excellent resistance to cracking and staining of the veneer surface, water resistance, and heat resistance.

[Prior art and its solutions] Conventionally, a mixture of amino resin, wheat flour niamino resin, homovinyl acetate resin, wheat flour niamino resin, ethylene-vinyl acetate resin, and wheat flour has been provided as an adhesive for decorative plywood veneer. However, with these adhesives, the veneer may dry out and the adhesive may seep onto the surface of the veneer. As an adhesive improved from these, Japanese Patent Publication No. 56-34196 describes
An adhesive has been proposed that is a mixture of an amino resin and a modified synthetic rubber latex that is made by copolymerizing a conjugated diene such as butadiene or isoprene, a vinyl monomer that copolymerizes with these, and a reactive monomer that reacts with amino groups, N-methylol groups, etc. There is.

However, even with this adhesive mixture of modified synthetic rubber latex and amino resin, prevention of drying and cracking of the veneer is still insufficient.

On the other hand, Japanese Patent Publication No. 40-22480 and Special Publication No. 47-
Publication No. 29291 etc. discloses that a fabric, paper, etc. is interposed between the veneer and the base plate, and the veneer is bonded with a mixture of amino resin, vinyl acetate resin, and wheat flour, and a mixture of modified synthetic rubber latex, wheat flour, and amino resin to prevent dry cracks in the veneer. There is a patent for the prevention of this, and the product is currently on the market and has received excellent reviews.

However, in the method of manufacturing veneer decorative plywood in which a fabric or paper is interposed between the veneer and the plywood, adhesive is applied to the surface of the base plywood, the fabric and paper are bonded, and then the fabric (paper) is Because the method involves applying adhesive again to the veneer, textile (paper), and plywood, the adhesive must be applied twice during the process, making the bonding process complicated, and further damaging the textile and paper. It is clear that the use of this will result in a significant increase in cost. In addition, when trying to simultaneously bond veneer and fabric, or paper and plywood, it is necessary to apply a large amount of adhesive in order to obtain stable adhesion, which may cause the adhesive to seep onto the surface of the veneer. This phenomenon occurs and causes problems in practical use.

Therefore, in order to prevent the adhesive from seeping onto the surface of the veneer and contaminating it, after applying the amino resin and vinyl acetate emulsion adhesive and the modified synthetic rubber latex and amino resin mixture adhesive to the plywood, Mixed adhesives of modified synthetic rubber latex and amino resin, which must be subjected to heat pressure during drying, have a lower adhesive strength on the veneer surface than adhesives made of amino resin alone or mixed with amino resin and vinyl acetate emulsion. Although the amount of adhesive seeping out is small and the occurrence of drying cracks is small, it is still not fully satisfied in practical terms.

The purpose of the present invention is to provide an adhesive for decorative processing of veneer that solves the problems of the prior art.It is possible to improve the dry cracking resistance of veneer by using adhesive alone without intervening textiles or paper. A further object of the present invention is to provide a material in which the oozing of the adhesive onto the surface of the veneer is practically satisfactory without the need for a work process in which the adhesive is intentionally semi-dried.

Another object of the present invention is to provide an adhesive for decorative veneer processing that has good water resistance and heat resistance.

Other objects and novel features of the present invention will become apparent from the entire description of this specification.

[Means for solving problems]

The present invention relates to an adhesive composition comprising a synthetic rubber latex and an acidified aminoethylated vinyl interpolymer described below, and an adhesive composition comprising a synthetic rubber latex, an aqueous emulsion, and the acidified aminoethylated vinyl interpolymer described above. Exists.

The synthetic rubber latex used in the present invention includes conjugated diene compounds such as phtadiene and isoprene.
Butadiene latex, chlorobrene latex, isoprene latex; copolymerization latexes of butadiene latex, isoprene latex, and polymers that can be copolymerized with these, such as acrylonitrile, styrene, and methyl methanoacrylate, are exemplified.

Also included are latexes obtained by modifying these synthetic rubber latexes with reactive monomers exemplified below.

Examples of such reactive polymers include monomers having a carboxyl group such as maleic acid, itaconic acid, and crotonic acid; acid anhydrides include itaconic anhydride and maleic anhydride; and monomers having an N-methylol group. Examples of monomers having a hydroxyl group include N-methylol acrylamide, N-methylol methacrylamide, and their ethers, and examples of monomers having a glycidyl group include glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, etc. Examples include allyl alcohol, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate, monoallyl ether of polyhydric alcohol, etc. - includes N,N-dimethylaminoethyl acrylate, vinylpyridine, tert-butylaminoethyl methacrylate, etc., and monomers having an amide group include acrylamide, methacrylamide,
Maleamide, etc.

The solid content concentration of these synthetic rubber latexes is 30 to 65
The acidified aminoethylated vinyl interpolymer used in the present invention, which is preferably 1% by weight (wt), is acidified by reacting a polymer represented by the formula with an acid.

(In the above formula, R and R' are the same or different hydrogen atoms or alkyl groups having 1 to 4 carbon atoms, the average value of n is 1.0 to 2.5, and the polymer before aminoethylation is is represented by -COOHJ& (having lNm) of 3 wt% or more, preferably 5 wt% or more.

Aminoethylated interpolymers are prepared from carboxyl-containing side chain vinyl interpolymers prepared by solution polymerization of monomer mixtures, one of which is a vinyl carboxylic acid monomer. The monomer mixture is polymerized using a catalyst, usually at a constant temperature increase, and the polymerization is stirred until completion.

Certain improved operations used in solution polymerization are carried out, such as stepwise introduction of the monomer mixture, addition of catalyst, reaction under an inert atmosphere or batch or continuous polymerization.

Vinyl carboxylic acid monomers include α/β-ethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, cinnamic acid, and crotonic acid; unsaturated dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid; Includes esters and mixtures thereof. Preferred vinyl carboxylic acids are unsaturated monocarboxylic acids, particularly preferred are acrylic acid and methacrylic acid.

Vinyl copolymers are copolymerizable monomers of vinyl carboxylic acid and Ill or more (e.g. vinyl aromatic alkyl esters of unsaturated monocarboxylic acids, dialkyl esters of unsaturated dicarboxylic acids, vinyl chloride, vinylidene chloride, vinyl pine). and N-vinylpyrrolidone, etc.).

Suitable vinyl aromatic monomers include styrene, alpha-methylstyrene, vinyltoluene, various alkyl-substituted styrenes, and various halogen-substituted styrenes. Particularly preferred vinyl aromatic monomers are styrene, alpha-methylstyrene and vinyltoluene. Suitable alkyl esters of unsaturated mono- and dicarboxylic acids include those obtained by esterifying the vinyl carboxylic acids described above with aliphatic alcohols containing 1 to 12 carbon atoms.

Esters of acrylic acid and methacrylic acid are preferred;
Particularly preferred esters are methanol, ethanol, isopropanol, and 2-ethylhexanol esters of acrylic and methacrylic acids. Minor acrylonitrile (up to 10%) may also be used to improve adhesive properties.

A preferred copolymer is prepared from styrene, one or more acrylic or methacrylic ester monomers, and vinyl carboxylic acid. As an example, styrene can be copolymerized up to 60% with acrylate monomers and carboxylic acids. Further, up to 90 wt% of acrylic monomer can be used.

The vinyl copolymer is preferably a carboxylic acid (-C
(as OOH) is 3% or more, more preferably 7.5~
It is manufactured using enough vinyl carboxylic acid to give 12.5w L%. The remainder is the preferred composition described above.

Suitable solvents for polymerization include alcohols, ketones, aromatic hydrocarbons and mixtures thereof.1 Polymerization temperature is 60°C.
It ranges from ~140<0>C, preferably from 80<0>C to 100<0>C, but the optimum temperature depends on the monomer catalyst and other conditions.

The aminoethylated interpolymers used in the present invention are prepared by an amination reaction in which a vinyl carboxylic acid interpolymer is reacted with an excess layer of alkylene imine or N(aminoalkyl)-substituted alkylene imine in a suitable solvent. A suitable alkyleneimine is ethyleneimine,
Includes 1.2-alkykenimines such as ethyleneimines such as propylene imine and butylene imine and mixtures thereof. Ethyleneimine is commercially available and is a preferred raw material. Particularly useful raw materials are N-(aminoalkyl)-substituted alkylene imines that have similar reactivity to alkylene imines and are less volatile than alkylene imines. Representative examples include N-(2-aminoethyl)aziridine, N-(3-aminopropyl)aziridine, N-(2-7minobrovir)propyleneimine, and N-(2-aminobutyl)butyleneimine. . N-(2-aminoethyl)aziridine, and N
-(2-7minobrovir)propyleneimine is particularly preferred.

Mu amino groups are bonded per carboxyl group in the interpolymer (i.e., the n value in the above formula is 1
．． 0 or more), the vinylcarboxylic acid interpolymer is reacted with 2 or more moles of alkylene imine based on the carboxyl equivalent in an organic solvent. The preferred molar range of alkyleneimine is 2 to 5, and the average n value is 1.5 to 2.
．． It is 5. In the case of N-(aminoalkyl)alkyleneimine, it is used in an amount of 1 mol or more, preferably 1 to 15 mol, based on the carboxylic acid equivalent.

The temperature of the amination reaction is 50°C or higher, preferably 50-1
It is 00℃. Some literature differs from this temperature range and describes a method of mixing at room temperature, holding at that temperature for a certain period of time, and then heating. The products obtained by that process, however, differ substantially in thermal stability from those of the present invention, and the aminoethylated interpolymers, which differ in amide nitrogen or unreacted acid content, also have interpolymers with carboxyl side chains. It can also be obtained by adding 1 to 2 moles of alkyleneimine to a polymer and reacting it at room temperature. The average n value of the aminoethylated interpolymers obtained is 1 to 1.3. The stability of interpolymers aminoethylated in this way is considerably poorer, but this is not a problem if the adhesive is used for a short period of time.

The reaction between alkylene amine or N-(aminoalkyl)alkylene and carboxylic acid group is preferably aprotic, such as a ketone such as methyl ethyl ketone, xylene, toluene, or ethylbenzene, or an aromatic hydrocarbon, but some or all of them are used. may be replaced with alcohol, 511 alcohols include aliphatic alcohols having 2 to 5 carbon atoms, fullylene glycols having 1 to 6 carbon atoms, alkyl monoethers of ethylene glycol and propylene glycol, and diacetone alcohol. do.

The amination reaction is carried out in a solvent consisting of 20% by weight or less of alcohol and the remainder being aromatic hydrocarbons.

After the amination reaction is completed, the solvent composition is stripped and the composition of the solvent is adjusted to 30~lowt% alcohol, 70~lowt% ketone or ether. Particularly preferred solvents include ethanol, propatool, isopropyl alcohol, isobutyl alcohol, n-butyl alcohol, n-butyl alcohol and the monomethyl ether of propylene glycol. Polymer concentration in the final product varies from 1 to 60 wt% depending on polymer solubility and application.

The aminoethylated copolymer is acidified by mixing the copolymer with an acid in a suitable water-miscible solvent or solvent mixture. Suitable solvents are lower alkyl ethers of ethylene glycol, brobylene glycol and dipropylene glycol, typical examples of which include butyl ether of propylene glycol, ethyl ether of ethylene glycol, propyl ether of diethylene glycol, isobutyl ether of mixed propylene glycol, etc. be.

Preferred acids are interpolymer amino 1lIljII
and form an acid salt. It is also desirable that the acid be volatile; therefore, formic acid or acetic acid are preferred; less volatile acids such as glycolic acid, propionic acid, butyric acid may also be used, but the water resistance of the resulting coating will be reduced.

Inorganic acids such as phosphoric acid may also be used.

The amount of acid used is usually equal to the amount of amino groups, but may be in excess or in deficit; the minimum amount necessary is that amount which provides water dispersibility of the acidic aminoethylated copolymer.

The mixing ratio (weight ratio,
(same below) is calculated as solid content, synthetic rubber latex/the interpolymer=t0010.1 to 100, preferably 10010.5 to 80. Particularly preferably 100/1~
It is 50. When the mixing ratio is less than 10010.1, that is, 100 parts of synthetic rubber latex! ! If the amount of the interpolymer is less than 0.1 part by weight, no sufficient effect will be observed on the cracking resistance of the veneer surface, and it will be difficult to obtain sufficient water resistance and heat resistance performance.
On the other hand, the mixing ratio is too/lo, which tends to affect the quality of the decorative veneer.

In other words, when the amount of the interpolymer exceeds 100 parts by weight relative to 00 parts by weight of the synthetic rubber latex, the water and heat resistant adhesive strength decreases significantly, causing a bank phenomenon on the surface of the veneer during thermopressure bonding. Wake up,
There is a lot of dry mold and mold, making it easy to be practically unusable.

In the present invention, a part of the synthetic rubber latex can be replaced by an aqueous emulsion. The formulation of this aqueous emulsion improves the applicability with a spreader roll, and also improves the mixability (compatibility) of flour, starches, extenders and fillers such as clay and silicic acid powder into the system. Furthermore, there is an advantage that the clay change of the adhesive mixed with these extenders and fillers can be reduced.

The mixing ratio of these synthetic rubber latexes and aqueous emulsions is arbitrary, but it is preferable to decide the mixture by taking into consideration the above-mentioned workability, dry cracking, oozing stain resistance, and water resistance.

Examples of the aqueous emulsion used in the present invention include homo-vinyl acetate emulsion resins, acrylic emulsion resins, and copolymer emulsion resins of vinyl acetate and ethylene, styrene, acrylic acids, vinyl chlorides, and the like.

Also included are emulsions obtained by modifying these aqueous emulsion resins with reactive monomers. Examples of the reactive rubber include the various rubbers exemplified in the synthetic rubber latex.

The solid concentration of the aqueous emulsion is 30-65vt%
It is preferable that

In the present invention, the mixing ratio (weight ratio, the same hereinafter) of the mixture of the synthetic rubber latex and aqueous emulsion and the acidified aminoethylated vinyl interpolymer is, in terms of solid content, synthetic rubber latex/the interpolymer = 10010
．． 1-100, preferably 10070.5-80, particularly preferably too/1-50. The mixing ratio is 10
If it is less than 0.010.1, that is, if the ratio of the interpolymer to 100 parts by weight of the synthetic rubber latex is less than 0.1, a sufficient effect on the cracking resistance of the veneer surface will not be recognized. It is difficult to obtain performance related to water resistance and heat resistance, and the quality of the decorative veneer is likely to be impaired.On the other hand, when the mixing ratio exceeds 100/100, that is, 100 parts by weight of the synthetic rubber latex and aqueous emulsion mixture On the other hand, when the interpolymer is in excess of more than 100 parts by weight, the water and heat resistant adhesive strength is drastically reduced, and in thermo-pressure bonding, punctures occur on the surface of the veneer, resulting in a large amount of cracking, making it practically unusable. It is likely possible.

Fillers and extenders conventionally used for manufacturing plywood and veneer may be added to the adhesive composition of the present invention.

These not only help in reducing costs, but also act as agents to prevent contamination from seeping of the adhesive onto the surface of the veneer in the veneer decorative processing of the present invention.

As these fillers and extenders, the following can be used. That is, for example, organic substances such as wheat flour, starches, defatted soybean flour, blood meal, walnut shells, coconut flour, and real flour, and neutral to acidic inorganic substances such as clay, kaolin, zeolite, silicic acid powder, and gypsum. substances can be used. Among these, wheat flour, starch, etc. are preferred because they can be made into a viscous liquid by gelatinization.

The mixing ratio of these fillers and extenders is usually such that the viscosity of the adhesive is 50 to 500 poise/25°C.

The adhesive composition of the present invention also includes substances used for improving viscosity, thickening, preventing drying, etc., such as polyvinyl alcohol, methyl cellulose, carboxymethyl cellulose,
Substances such as hydroxyethyl cellulose, polyethylene oxide, and alginic acid may also be blended.

Additionally, high-boiling solvents conventionally used as plasticizers for synthetic rubber latex and aqueous emulsions, such as dibutyl phthalate (DBP), dioctyl phthalate (DOP), diethyl glycol sebacate, ethylene glycol, polyethylene glycol, butyl calpitol Substances such as acetate can also be blended.

[Examples] Next, the present invention will be explained with reference to Examples, but the present invention is not limited to these Examples in any way.

Unless otherwise indicated, all percentages and parts in the examples are by weight.

Example 1 Carboxyl-modified styrene-butadiene synthetic rubber latex [manufactured by Japan Synthetic Rubber Co., Ltd., JSR-057]
3. Particle system 2,300A, solid content 49%, viscosity 150
To 1,100 parts of Seven Inch Boyz/25°C, 25 parts of wheat flour and 5 parts of acidified aminoethylated vinyl interpolymer (Polyment NK-100PM manufactured by Nippon Shokubai Co., Ltd.) were mixed,
An adhesive for veneer decorative plywood having a viscosity of 250 voids/25° C. was obtained.

Example 2 Neoblen latex (manufactured by Showa Neoblen Co., Ltd. [115]
)+oo parts, 25 parts of wheat flour and 5 parts of acidified aminoethylated vinyl interpolymer [same as in Example 1] were mixed to obtain an adhesive for veneer decorative plywood having a viscosity of 260 voids/25°C.

Example 3 50 parts of the carboxyl-modified styrene-butadiene synthetic rubber latex used in Example 1 and vinyl acetate emulsion resin (solids 45%, viscosity 6001 is/30°C,
4% polyvinyl alcohol, 0.0% nonionic surfactant.
05%), 4 parts of DBP as a film forming agent, and 10 parts of acidified aminoethylated vinyl interpolymer (same as in Example 1) were mixed to obtain an adhesive composition. Then, 15 parts of wheat flour is added and mixed to 100 parts of the composition,
An adhesive for veneer decorative plywood having a viscosity of 250°C and 41/25°C was obtained.

Example 4 Emulsion resin (vinyl acetate 92%
．． 8%, N-methylolacrylamide 6.2%, acrylic acid 1.0%, solid content 52%), 4 parts DBP as a film forming agent, and 5 acidified aminoethylated vinyl interpolymers (same as in Example 1). The components were mixed to obtain an adhesive composition. Then, 15 parts of wheat flour was added and mixed with 100 parts of the adhesive composition to obtain an adhesive for decorative plywood having a viscosity of 26014 x 725°C.

Comparative Example 1 For 100 carboxyl-modified styrene-butadiene synthetic rubber latex used in Example 1, 30 pieces of wheat flour were added.
A veneer decorative plywood adhesive having a viscosity of 250 volts χ/25° C. was obtained.

Comparative Example 2 20 parts of wheat flour was mixed with 100 parts of the acidified aminoethylated vinyl interpolymer used in Example 1, and the viscosity was 2.
An adhesive for veneer decorative plywood having a temperature of 5014 z/25° C. was obtained.

Comparative Example 3 100 parts of the synthetic rubber latex used in Example 1 was added with a melamine-urea-formaldehyde copolymer resin (Daijin Resin PWP-8J manufactured by Daijin Shinko Co., Ltd. Solid content 54%, viscosity 0.6 voids/25°C) ) and then 20 parts of wheat flour were added and mixed to obtain an adhesive for veneer decorative plywood having a viscosity of 250 boids/25°C.

Comparative Example 4゜Ethylene-vinyl acetate emulsion resin (manufactured by Kuraray Co., Ltd.)
Panflex 0M-4000J engineered tyrene containing W120%
, solid content concentration 55%, viscosity! Add 30 parts of wheat flour to 100 parts of
An adhesive for veneer decorative plywood at 5° C. was obtained.

Using the thus obtained adhesive for decorative veneer plywood, adhesive was applied under the following working conditions to create decorative veneer plywood.

*Bottom plate, front and back: 1.2m/m thick, 12ffi/I11 lauan plywood *Temporary veneer; 0.2m/a thick, 40-60%
Water-containing, wood grain and straight grain of Japanese zelkova, Japanese pine, and oak wood *Applying it: long/m” *Deposition: Open deposition time, closed at 720℃ within 30 seconds 〃6
Within 0 seconds/20°C *Heat pressure: 10°C, 7-8 kg/cm'', 60 seconds *Curing: 20°C, 1 day Comparative Example 5° Vinyl acetate emulsion resin (solid content 45%).

Viscosity: 600 poise/30°C, 4% of Poval, 0.05% of nonionic surfactant), 4 parts of the film forming agent DBP, and 50 parts of the melamine-urea-formaldehyde copolymer resin used in Comparative Example 3 were blended. Further, 20 parts of wheat flour was added and mixed to obtain an adhesive for veneer decorative plywood having a viscosity of 250441725°C.

Using the adhesive for veneer decorative plywood obtained in Comparative Example 5,
Apply 120g/m of this veneer decorative plywood adhesive to 5-brie 12m/m thick lauan plywood with a surface thickness of 1.2m/-.
After tl attachment, 31 g/m" unsized kraft paper was temporarily glued with a rubber roll and dried for 15 minutes in a dry bed at 40'C.
After drying for a few minutes and being completely dry to the touch, use a flat plate press to obtain I Okg/cm.
``Heat press at 100℃ for 60 seconds, then apply 100g/m'' of adhesive with the same composition as above on the kraft paper of the kraft paper plywood, and apply 0.2m/+m.
Thick Japanese zelkova, Japanese pine, and oak veneers were stacked on top of kraft paper plywood and deposited for 10 minutes at 20"C, then heated under heat-pressure conditions of 110T:, 7-8 kg/cm" for 60 seconds. They were glued together using a flat press to create decorative plywood veneers.

The surface of the decorative plywood veneer obtained as described above was coated with amino alkyd under the following conditions.

l) Undercoat The following undercoat paint formulation Melbicoat Sanding Sealer #36 (manufactured by Wasshin Chemical Industry Co., Ltd.) 10g 11 Hardening agent No. 1 (same as above) 1
Melbicoat Thinner No. 45 (same as above) 2
part, on the veneer surface of No. 320 sanded veneer decorative plywood,! 1! Included! It was applied uniformly at 5.5 g/2 of L and dried at 60° C. for 15 minutes.

2) The veneer surface of the veneer decorative plywood that has been painted with top coat and undercoat is NO, 320.
After sanding with the following top coat composition Melbicoat Clear #20 (manufactured by Washin Kagaku Kogyo Co., Ltd., 10 parts hardening agent No.
, l 1 part Melbicoat Thinner No. 45 2 parts was evenly applied to the surface of the veneer at a coating amount of 5.5 g/+i'', and then dried at 60°C for 15 minutes.

[Evaluation Test] The decorative plywood veneer coated with the amino alkyd coating was subjected to a dry cracking test, adhesion, and oozing contamination test under the following conditions and evaluated. The results are shown in Tables 1 and 2.
Shown in Table and Table 3.

Test method 1-1 Drying crack test After leaving a 15 cm square veneer decorative plywood test piece in a thermostat at 60 ± 3°C for 2 hours, the process of leaving it in a thermostat at -20 ± 3°C for 2 hours was carried out in step 1. cycle, 2 cycles 6
After repeating the cycle for 12 times and leaving it to reach room temperature, measure the length of the crack (m/ml) using a magnifying glass (loupe x7).
).

1-2 Exudation contamination test Apply 50 g/1 m of wiping paint (Last Line, Wasshin Chemical Industry Co., Ltd.) to a test piece of veneer decorative plywood of 30C1.
The adhesive was applied uniformly with a 100-degree press, and the presence or absence of oozing of the adhesive was visually determined.

1-3 Adhesion performance 75@/+s square veneer decorative plywood test piece at 70±3℃
The adhesive layer was immersed in hot water for 2 hours and then dried in a drying layer at 60±3° C. for 3 hours for 5 cycles, and the peeling length of the adhesive layer was measured.

The judgment is based on the length of the non-peeling part of the same adhesive layer of the special plywood according to the Japanese Agricultural Standards on each side. An adhesive composition with excellent water-resistant and heat-resistant adhesive properties, especially for decorative processing of veneers, can be provided. In addition, we were able to provide a solution that is practically satisfactory, even if the adhesive does not ooze out onto the surface of the veneer without performing a work process that requires the adhesive to be semi-dry.

Patent applicant: Oshika Shinko Co., Ltd.

Claims (1)

[Claims] 1 Synthetic rubber latex and the formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R and R' are the same or different hydrogen atoms or lower alkyl groups having 1 to 4 carbon atoms, The average value of n is 1.0 to 2.5), and the interpolymer has at least 3% by weight of side chain -COOH groups before being aminoethylated. An adhesive composition comprising an acidified aminoethylated vinyl interpolymer obtained by reacting an acid with an interpolymer having the following. 2. Synthetic rubber latex, aqueous emulsion, and claim 1
An adhesive composition comprising the acidified aminoethylated vinyl interpolymer described in . 3. The adhesive composition according to claim 1 or 2, wherein the adhesive composition is an adhesive for decorative veneer processing.