JPH0270784A - Adhesive composition - Google Patents

Abstract

PURPOSE:To obtain an adhesive composition, as a plywood adhesive, improved in adhesion to resinous wood and durability and shortened in a hot-pressing time by mixing a formalin condensation resin with an acidified aminoethylated vinyl interpolymer. CONSTITUTION:An adhesive composition is formed by mixing 100pts.wt. (in terms of solid matter) formalin condensation resin (A) (desirably, a condensate of formaldehyde with an amino compound such as urea in a molar ratio of 1.5-2.8, having a solid content of 45-75%) with 0.05-50pts.wt., desirably, 0.5-20pts. wt. acidified aminoethylated interpolymer [a salt of an aminoethylated interpolymer of the formula (wherein R and R<1> are the same or different and are each H or a 1-4 C alkyl, and n is 1.0-2.5 on the average with formic acid or acetic acid].

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to 114M compositions.

Specifically, the present invention relates to an Adhesive M composition that has excellent adhesion to wood of any resin content, shortens heat-pressing time, and has excellent durability, particularly as an adhesive for laminated wood.

(Conventional technology and its problems) Traditionally, formalin-based condensation resin adhesives are urea-based.

Amino compound exclusively for melamine and pesozoguanamine.

and one or more phenolic compounds of the phenol and resorcinol list1. and formaldehyde are condensed to form 61.

When these 41!1 cuttings are used as an adhesive for plywood, for example, the initial M adhesive strength (temporary adhesive strength) is poor, and the plywood peels off even after cold sweat adhesion, and the next round of hot adhesive This causes major problems, poor productivity, and causes defective plywood.

Conventionally, polyvinyl alcohol (1)■△) has been used as a method for improving such initial adhesive strength. and carboxymethyl cellulose are blended during the synthesis of formalin-based condensate resins.

However, carboxymethyl cellulose exhibits only one thickening effect and lacks initial adhesive strength, and polyvinyl alcohol has poor storage stability as it gels when left standing.

Adding polyvinyl alcohol during starch making has a thickening effect similar to carboxymethyl cellulose, resulting in high viscosity and poor workability.

1) There is a drawback that increasing the VΔ hardness reduces water resistance.

At present, the following method is being used to shorten the hot pressing time, which can improve productivity in the production of plywood, using amino compounds of formalin-based condensation resins. That is, in order to harden the amino compound of the formalin-based condensation resin, strong acid catalysts such as hydrochloric acid, aluminum chloride, formic acid, para-toluene sulfonic acid, etc. are used, or ammonium salts that react with formaldehyde to release acidic substances, such as ammonium chloride. A method is used in which the lit of ammonium phosphate and ammonium oxalate is increased, and the p I+ is lowered over time for curing.

However, methods that reduce the pH and increase the amount of strong acids that cause hardening or substances that release acidic substances by reacting with formaldehyde have the effect of increasing the viscosity of the glue by 1%, and the current method of setting the plywood production line at the spritzer roll. , flow coater has poor workability <,! J! In this way, if the number of substances that react with strong acids and formaldehyde to release acidic substances increases and the pH decreases, the adhesive deteriorates quickly and has poor durability, and the acid deterioration of the wood structure. This leads to a decrease in adhesive strength, and it is no longer used.

Currently, methods to improve the durability of formalin-based condensation resin-bonded fRM include adding acids such as citric acid, lactic acid, phthalic acid, and cohelic acid, and copolymerizing epoxies, isocyanates, and phenols. is considered.

However, the method of adding Class A shortens the pot life, and the method of copolymerizing with epoxies, isocyanates, and phenols increases the price of liquid M, lengthens the heat-pressing time, and Poor adhesion and poor workability leave scratches.

The present invention aims to eliminate the drawbacks of such prior art.

Step F for Solving Problem 1] To achieve the above object, the present invention relates to an adhesive composition comprising a formalin-based condensation resin and an acidified aminoethylated vinyl interpolymer.

The formalin-based condensation resin used in the present invention is a condensation resin of formalin and an amino compound, such as one or two of the amine compounds urea, melamine, and guanamine.
, → and formalin, or a condensation resin of formalin and a phenol compound, such as a condensation resin of formalin and one or more of phenol and resorcinol.

Also included are modified resins in which these resins are partially modified with acetal L alnyl, polyvinyl alcohol, and the like.

Among these, a condensation resin of an amino compound and formalin is particularly preferable, with a molar ratio of formaldehyde/amino compound=1.1 to 3.0 and a solid content of 35 to 100%, preferably formaldehyde/amino compound. It is suitable that the system compound is 1.5 to 2.8 and the solid content is 40 to 75%.

The acidified aminoethylated vinyl interpolymer used in the present invention is.

It is made by reacting the polymer represented by the formula with an acid to make it acidic.

(In the above formula, R and R' are the same or different hydrogen atoms or alkyl groups having 1 to 4 carbon atoms, the f uniformity of n is 1.0 to 2.5, and the The polymer has 3 wL% or more, preferably 5 wL% or more of -COO11 side chains).

The aminoethylated interpolymer is prepared from a 54m carboxyl-containing fM chain vinyl interpolymer by solution polymerization of a monomer mixture, one of which is a vinyl carboxylic acid monomer. The monomer mixture is combined using a catalyst, usually at a constant temperature, and the mixture is stirred until completion.

Certain modifications of the procedures used in solution polymerization are carried out, such as stepwise charging of a 1,000 ml mixture, addition of catalyst, reaction under an inert atmosphere, or batch or continuous -R summation.

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.

A vinyl copolymer is an alkyl ester of a vinylcarboxylic acid and one or more co-Ir-merizable monomers (e.g. vinyl), a five-aromatic unsaturated monocarboxylic acid,
j''1 can be obtained by copolymerizing dialkyl esters of unsaturated dicarboxylic acids, vinyl chloride, vinylidene chloride, vinyl sulfide, N-vinylpyrrolidone, etc.).

Suitable vinyl-27 aromatic monomers include styrene, alpha methylstyrene, vinyltoluene, the divine alkyl iFI substituted styrene, and various halogen-substituted styrenes. Particularly preferred vinyl aromatic honeycombs are styrene, alpha-methylstyrene and vinyltoluene. Suitable alkyl esters of unsaturated mono- and dicarboxylic acids include esters obtained by esterifying the vinylcarboxylic acid described in 1- with an aliphatic alcohol having from 1 to 12 carbon atoms. Esters of acrylic acid and methacrylic acid are preferred, particularly preferred esters of acrylic acid and methacrylic acid are methanol, ethanol, isopropanol, butanol, 2-ethylhexanol esters. Small amounts of acrylonitrile (up to 10%) can also be used to modify the properties of adhesive M.

Preferred copolymers are styrene, IM or more;
acrylic acid or methacrylic acid ester monomer and vinyl carboxylic acid. As an example, styrene can be copolymerized up to 60% with 7 acrylate monomers and carboxylic acids. Moreover, acrylic monomer can be used up to 90wL%.

The vinyl copolymer is preferably a carboxylic acid river 11(-
(as COOH) is 3% or more, preferably 7.5
It is manufactured using enough vinyl carboxylic acid to be ~12.5 wt.%. and the remainder are preferred comonomers listed in F.

Suitable solvents for polymerization include alcohols, ketones, aromatic hydrocarbons and mixtures thereof. Togane temperature is 60℃
The range is from 140°C to 140°C, preferably from 80°C to 10°C, with the optimum temperature depending on the catalyst and other conditions.

The aminoethylated interpolymer used in the present invention consists of a vinylcarboxylic acid interbo-11mer in a suitable solvent.
It is prepared by an amination reaction in which excess Fit is reacted with an alkylene imine or an N-(aminoalkyl) substituted alkylene imine. ll! Suitable alkyleneimines include 1,2-alkyleneimines such as ethyleneimines such as ethyleneimine, propyleneimine and butyleneimine, and mixtures thereof. Ethyleneimine has been reprinted and is preferred.

A particularly useful raw material is N-(
aminoalkyl)-substituted alkyleneimine. Typical examples include N-(2-aminoethyl)aziridine, N-(
3-aminopropyl)aziridine, N-(2-aminopropyl)propyleneimine and N-(2-aminobutyl)butyleneimine calculations are n/f. Particularly preferred are N-(2-aminoethyl)aziridine and N-(2-amino,nobrovir)propyleneimine.

N several amino groups are bonded per gram of carboxyl group in the interpolymer (i.e. nfA in the above formula
In 2), the vinylcarboxylic acid interpolymer is reacted with 2 moles or more of alkylene imine per 5 carboxyl groups in an organic solvent. The preferred molar range of alkyleneimine is 2 to 5, and f average nl [is 1.
5 to 2.5. In the case of N-(aminoalkyl)alkylene/imine, it is a carboxylic acid! It is used in an amount of 1 to 1 mole, preferably 1 to 15 moles, based on J Fat.

The temperature of the amination reaction is 50°C or higher, preferably 50°C or higher.
The temperature is 100°C. Of course, higher temperature and pressurized conditions are also implemented. Different from this temperature range, some literature describes a method of mixing at room temperature, holding at that temperature for a certain period of time, and then heating. Depending on the method, the resulting product, however, differs substantially from that of the present invention in thermal stability and in amide nitrogen or unreacted acid content.

Aminoethylated interpolymers can also be prepared by adding 1 to 2 moles of alkylene imine to an interpolymer having carboxyl side chains and reacting at room temperature. The resulting aminoethylated interpolymer has an average n value of 1 to 1.3. The stability of interpolymers aminoethylated in this way is considerably poorer, but this is not noticeable if the adhesive is used for a short period of time.

The reaction between alkyleneamine or N-(aminoalkyl)alkylene and carboxylic acid group is preferably an aprotic ketone such as methyl ethyl ketone, xylene, toluene, ethylbenzene, or a manganese hydrocarbon. Alternatively, all alcohols may be replaced with alcohols. Suitable alcohols include aliphatic alcohols having 2 to 5 carbon atoms, alkylene glycols having 1 to 6 carbon atoms,
Includes alkyl monoethers of ethylene glycol and propylene glycol and diacetone alcohol.

The amination reaction is carried out in a solvent consisting of at least 20 wL% alcohol and the remainder aromatic hydrocarbons.

After the amination reaction is completed, the solvent composition is stripped and fa
The composition of the medium is alcohol 30-1.

w 1. Particularly preferred solvents are ethanol, propatool, and isopropyl alcohol.

Includes isobutyl alcohol, n-butyl alcohol, n-butyl alcohol and the monomethyl ether of propylene glycol. The polymer concentration in the final product varies from 1 to 60 depending on the solubility of the polymer and the application.
w L%.

Aminoethylated copolymer is l! Acidification is achieved by mixing the copolymer with an acid in a water-miscible solvent or solvent mixture. Suitable solvents are lower alkyl ethers of ethylene glycol, propylene glycol and dipropylene glycol, typical examples being butyl ether of propylene glycol, ethyl ether of ethylene glycol, propyl ether of diethylene glycol, and isobutyl ether of mixed propylene glycols. .

Preferred acids are interpolymer amino am and acid salts (a
cid 1alL). It is also desirable that the acid is volatile, so formic acid or acetic acid is c? Preferred, less volatile acids such as glycolic acid, propionic acid, and acetic acid may also be used. Inorganic acids such as phosphoric acid are also used.

The acids used usually have amino groups! is equal to a, but can be either an excess of 1d or a deficiency of M.6 The required minimum is when the acidic aminoethylated copolymer attains water dispersibility.

In the present invention, ``A'' mixing ratio of the formalin condensation resin and the acidified aminoethylated interpolymer (weight ratio,
Hereinafter the same) is calculated as solid content, Holimarine condensation resin/polymer = +0070.05~50°, preferably 10
070.5-20.

The adhesive of the present invention contains an aqueous emulsion conventionally used as a glue for wood materials and synthetic rubber latex.

Examples of aqueous emulsions include vinyl acetate emulsion resins, acrylic resins, Margin resins, homoemulsion resins in the Itt vinyl resin list, or 2% to 10%! Tr combined emulsion resin and ethylene,
Examples include resins copolymerized with styrene.

Examples of synthetic rubber latex include butadiene,
Examples include copolymerized latexes containing a conjugated diene compound such as isoprene, such as butadiene latex, chlorobrene latex, and isoprene latex, and monomers that can be copolymerized with these, such as acrylonitrile, styrene, and methyl acrylate. In addition, latexes obtained by modifying these synthetic rubber latexes with reactive rubbers exemplified in F below are also included as reactive rubber latexes.
For example, monomers having a carboxy group such as maleic acid, monomers having an acid anhydride such as maleic anhydride, monomers having an N-methylol group such as N-methylolacrylamide, and amino groups such as vinylpyridine. Examples thereof include 100-molecular weight having a hydroxyl group such as acrylamide, and a 1000-molecular weight group having an amide group such as acrylamide.

Further, the adhesive composition of the present invention may further contain a thickening agent. This increase in 111 cuts not only increases, but it also reacts in a complex manner with the other components of the adhesive, formalin and acidified aminoethylated vinyl interpolymer, improving durability and intercut adhesion. There are also other effects.

For example, wheat flour, starch, etc., which are added to the adhesive of Shirane Seisho of the Congo Song Dynasty as increase fit /R1! n, defatted soybean flour, blood meal, etc. can be used.

Further, a filler can be further blended into the adhesive set 1 of the present invention. This filler not only prevents the adhesive from penetrating excessively into the wood, but also reacts in a complex manner with the other components of the adhesive, including formalin, acidic amide, and noethylated vinyl interpolymer. , durability, and -11 layer adhesion.

As fillers, clay, kaolin, zeolite, silica powder (1 stone) [1 neutral to acidic inorganic substances, wood flour, walnut shells, and coconut fibers are conveniently used. Do + do.

The compounding ratio of these refining and/or fillers is 10 to 10011% based on the formalin condensation resin, and in particular, the compounding ratio of plywood welding 11M is suitably in the range of 15 to 50%. Further, these increasing Fl/Fl and filler may be used alone or in combination.

Furthermore, the adhesive composition of the present invention generally contains an acidic substance as a catalyst for curing the formalin-based condensation resin, or an ammonium salt that reacts with formaldehyde to release an acidic substance, such as hydrochloric acid, valatoluenesulfonic acid, chloride. Aluminum, ammonium chloride, ammonium phosphate, ammonium oxalate can also be added.

Further, the composition of the present invention may contain polyvinyl alcohol, methyl cellulose polyethylene oxide, carboxymethyl cellulose, hydroxyethyl cellulose, and an aqueous polymeric thickener exclusively for alkynic acids.

The IIa agent composition of the present invention is particularly suitable as an adhesive for white roots or its secondary adhesive.
It is 1111 things as a river glue.

[Example J Next, the present invention will be further explained with reference to Examples, but the present invention is not limited thereto.

Example 1゜Formalin-1polymer resin (molar ratio formaldehyde/
Urea: 2.3. fA1 type 50%, viscosity 2. f
l+'/25°C) and 5 parts of acidified aminoethylated vinyl interpolymer (1-1 made by this catalyst [Polymen 1
-NK-100PMJ, 17 parts of wheat flour, 13 parts of water, and 0.5 parts of ammonium chloride were mixed, and the viscosity was +001)72
The adhesive composition at 5°C is 1').

Example 2 Formalin-urea-P ■△ resin (molar ratio formaldehyde/urea = 25 Φ degree of 1700 and saponification degree of 99 mol%) V△ to urea: 36 parts.

Condensate (solid content 50%, viscosity 1.5P/25℃)
100 parts and 5 parts of acidified aminoethylated vinyl interpolymer ([1] Boliment NK-10100P,
17 parts of wheat flour, 13 parts of water, and 0.5 part of ammonium chloride were mixed to obtain an adhesive composition having a viscosity of 120P and 725°C.

Example 3 Formalin-melamine-urea copolymer resin (molar ratio
Formaldehyde/urea-melamine = 2/1. Solid content 5
5%, viscosity 0.9P/25°C) to 100 parts of acidified aminoethylated vinyl interpolymer (Nippon Shokubai [Polyment NK100PMJ 5 parts, wheat flour 1711, water 1
Mix 0 parts of ammonium chloride and 0.5 parts of ammonium chloride to obtain a viscosity of 10
A 5P725° C. aM composition was obtained.

Example 4 Formalin-melamine-urine J-PVA (polyvinyl alcohol) resin (molar ratio: formaldehyde/urea-melamine = 2.7/1. PVA with a saponification degree of 99 mol% and a saponification degree of 1700 was mixed with urea to .8 parts, solids content 54%, viscosity 1.0P 725°C condensate) loO7'ls and acidified aminoethylated vinyl interpolymer (Japan
yr Boriment N -+001) MJS Department, Flour 17
;■, Water +0811 and 0.5 part of ammonium chloride were mixed to obtain an adhesive composition with a viscosity +301) of 725°C.

Comparative Example 1 100 parts of the formalin-urea resin used in JmN+, 17 parts of wheat flour, 13 parts of water, and 0.5 part of ammonium chloride were mixed to obtain an adhesive composition with a viscosity of 2511/25°C.

Comparative Example 2゜Formalin-urea-PvΔ resin lO used in Actual Example 2
O parts, 17 parts of flour, 13 parts of water, and ammonium chloride 0
．． 5 parts were mixed to obtain a contact aM composition with a viscosity of 25 P/25°C.

Comparative Example 3 100 parts of the formalin-melamine-urea copolymer resin used in Example 1 and Example 3 were mixed with 17 parts of wheat flour, 10 parts of water, and 0.5 parts of ammonium chloride to create an adhesive composition with a viscosity of 25P/25°C. I got it.

Comparative Example 4゜Formalin-melamine-urea-1 used in Example 4)
100 parts of VA resin, 17 parts of wheat flour, 10 parts of water, and 05 parts of ammonium chloride were mixed to obtain an adhesive composition having a viscosity of 23P/25°C.

Using the adhesive navy composites of Examples 1 to 4 and Comparative Examples 1 to 4 thus obtained, bonding was performed under the following working conditions to create plywood, and durability was evaluated.

Single machine! 4 Neck and composition: Red lauan 1.7ms + 1.7m/
s++1.7+1/@coating H1tt: 155g/@a+-allfl) Cold pressure, 20℃X I Okg/cm"x 30 minutes hot pressure
1+5℃ x 1 Okg/cs" The adhesion strength was repeatedly tested and the ml durability was determined.

The results are shown in Table-1 and Table-2.

1.Normal Adhesion Test The test piece is subjected to an adhesion test in a normal state at 20°C±2°C and 65±10% RII to determine the shear strength and average center rupture rate.

2. ffi cold water immersion adhesion test After soaking the test piece in warm water at 60°C ± 3°C for 3 hours,
Immerse it in water at room temperature until it cools down, perform an adhesive strength test while wet, and determine the shear strength and average center rupture rate.

3 Repeated boiling adhesion test After soaking the test piece in boiling water for 4 hours at 60℃±3℃
The adhesive was dried for 20 hours at a temperature of demand.

4 After immersing the saturated water test piece in warm water at 60°C ± 3°C for 8 hours,
One cycle is the step of leaving the product in a dryer at 0°C ± 3°C for 40 hours, and after 11 cycles, it is left at room temperature for 8 hours, an adhesive strength test is conducted, and the shear strength and average center rupture rate are determined.

Example 5 Formalin-urea resin (molar ratio: formaldehyde/urea = 1.9. Solid content 7:3%, viscosity 25P/25°C
) to 100 parts of acidified aminoethylated interpolymer (
[1 Catalyst '37 NK-1001) 12 parts of M, 8 parts of wheat flour, 15 parts of ammonium chloride 1. Mix 6 parts of water,
Viscosity: 3211 / 25℃ adhesion M 11 composition 11
Also.

Example 6 Formalin-urea resin (molar ratio, formaldehyde/urea = 19, solid content 7:3%, viscosity 25P 725°C)
100 parts of vinyl acetate emulsion resin (Shintsu Pond No. 26 (Oshikashin H52 solid content 35%, viscosity 800 F)
' / 30℃) 201L acidified aminoethylated interpolymer (1-1 catalyst 'X? NK-100PM
>2 parts, 8 parts of wheat flour, 15 parts of ammonium chloride, and 6 parts of water were mixed to obtain an adhesive composition with a viscosity of 33 P/25°C.

Comparative Example 5 100 parts of the formalin-urea resin used in Example 5, 8 +'fi of wheat flour, 1.5 parts of ammonium chloride, and 6 parts of water were mixed to obtain an adhesive composition with a viscosity of 32P/25°C.

Comparative Example 6 20 parts of the formalin-urea resin 005L vinyl acetate resin used in Example 6, 8 parts of wheat flour, 1.5 parts of ammonium chloride, and 4 parts of water were mixed, and the mixture had a viscosity of 3:3 P.
/25°C adhesive composition was obtained.

Using the adhesive compositions of Examples 5 to 6 and Comparative Examples 5 to 6 thus obtained, the adhesion of test pieces bonded using Kometsuga wood with a resin content under the following working conditions was determined by IAS.
According to the immersion peeling test of "Japanese Agricultural Standards for Laminated Wood" =
An f value was performed.

Adherent material and structure, 4 to 6 m/m thickness 20 as shown in Figure 1
+s+m Width 98s/-, 3 braises of hemlock wood with resin content 2, Coating sound: 230 germ": 3 Deposition, within 15 minutes at 720℃ Pressing 7 kg/am" X l 2 hours/25℃Curing: 25℃ ×7 hours [Effects of the Invention] According to the present invention, the conventional drawbacks of formalin-based combination resin adhesives, especially when used as adhesives for white roots, have been solved, the heat-pressing time has been shortened, and the adhesive has excellent durability. An adhesive composition could be provided.

Patent applicant: Oshika Shinko Co., Ltd.

Claims (1)

[Claims] Formalin-based condensation resins have formulas ▲mathematical formulas, chemical formulas, tables, etc.▼ (wherein R and R' are the same or different hydrogen atoms or lower alkyl groups having 1 to 4 carbon atoms, n The average value of An adhesive composition comprising an acidified aminoethylated vinyl interpolymer obtained by reacting the interpolymer with an acid.