JPS6189276A - Adhesive - Google Patents

Abstract

PURPOSE:A novel adhesive having extremely improved adhesiveness, an alkali neutralized terpolymer of isobutylene, maleic anhydride, and vinyl acetate. CONSTITUTION:A terpolymer preferably consisting of (A) 1mol isobutylene, (B) 0.7-1.2mol maleic anhydride, and (C) 0.05-1.2mol vinyl acetate is prepared, and the terpolymer is neutralized with an alkali (e.g., sodium hydroxide), to give the aimed adhesive. The neutralization is preferably carried out at 50-100 deg.C at 0-2kg/cm<2>G for 20.5-10hr.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to adhesives, and more particularly to novel adhesives with excellent adhesive properties.

It has been known to use an alkali neutralized product of isobutylene-maleic anhydride as an adhesive. However, the isobutylene-maleic anhydride copolymer that is the raw material for this adhesive is extremely hard, and its alkali neutralized product also has poor adhesive properties and is not fully satisfactory as an adhesive.

Therefore, the inventor of the present invention made extensive studies to develop an adhesive with improved adhesive properties, and found that by using an alkali-neutralized product made from a novel terpolymer, adhesives with improved adhesive properties were developed. The present invention was completed based on this finding.

That is, the present invention is an adhesive comprising an alkali neutralized product of isobutylene-maleic anhydride-vinyl acetate terpolymer.

The isobutylene-maleic anhydride-vinyl acetate terpolymer used as the material of the present invention is isobutylene.

It can be obtained by copolymerizing maleic anhydride and vinyl acetate by various methods, but it is usually produced by the following method.

The charging ratio of each raw material is not particularly limited, and may be appropriately determined in consideration of the physical properties of the intended copolymer. Usually 0.5 to 1.0% maleic anhydride per mole of isobutylene.
5 mol, preferably 0.7-1.2 mol, vinyl acetate 0
．． 01 to 1.5 mol, preferably 0.05 to 1.2 mol.

In addition, a catalyst is used during copolymerization, and in this case, various catalysts can be used, but usually benzoyl peroxide, lauroyl peroxide, cumene perhydroxide, t-butylhydroberoxide, dicumyl peroxide, etc. Examples include peroxides such as oxide, azo compounds such as azobisisobutyronitrile, and persulfates. The amount of catalyst used is o, oi-io parts by weight, preferably 0.05 to 5 parts by weight, based on 100 parts by weight of the total monomers. The catalyst can be used as is or diluted. At the time of its addition, the solvent used in the copolymerization reaction can be inoculated, for example, when the copolymerization reaction is carried out by precipitation polymerization, isopropyl acetate, ethyl acetate, acetone, etc. be. In this case, the terpolymer produced does not dissolve in the solvent and precipitates outside the copolymerization reaction system. on the other hand,
Solvents used when the copolymerization reaction is carried out by solution polymerization include N,N-dimethylformamide, dimethyl sulfoxide, acetonitrile, nitromethane, nitroethane, and the like. In this case, the resulting terpolymer is dissolved in the solvent. Considering the reaction progress rate and productivity of the copolymer, the latter N.

Solvents such as N-dimethylformamide are preferred.

The conditions for the copolymerization reaction using the above raw materials, catalysts and solvents are as follows:
200°C, preferably 45 to 150°C, reaction pressure normal pressure to
30kg/cnlG, preferably normal pressure to 10kg/aa
jG, reaction time 0.5-20 hours, preferably 1-10
The time is appropriate. Next, an isobutylene-maleic anhydride-vinyl acetate copolymer is obtained by performing usual post-treatments such as removing the solvent and unreacted raw materials. This product is composed of isobutylene repeating units, maleic anhydride repeating units, and vinyl acetate repeating units, and has a number average molecular weight of about 3,000 to 400,000, preferably about 5,000 to 200,000. Further, the repeating unit ratio is isobutylene:maleic anhydride:vinyl acetate=t:O,S~1.5:0.01~1.5 (molar ratio), preferably 1:0.7~1.2:o , o 5~
The molar ratio is 1.2.

The adhesive of the present invention can be obtained by subjecting the thus obtained copolymer to an alkali neutralization treatment. Such neutralization treatment causes the maleic anhydride repeating unit to undergo neutralization and ring opening to form a salt. The alkali used here is sodium hydroxide.

RM sodium, ammonium carbonate, ammonia.

Organic amines, sodium acetate, ammonium acetate.

Examples include urea, thiourea, and sodium silicate. Among these, sodium hydroxide, ammonium hydroxide, etc. are preferred. Neutralization treatment is usually carried out using an aqueous alkali solution. The amount of alkali to be used is an amount that gives a degree of neutralization of 0.3 to 1.0, assuming that complete neutralization is defined as neutralization solution 1.

In addition, the conditions for neutralization treatment are generally at a temperature of 20 to 15
0°C, preferably 50-100°C, pressure 0-5 kg/
cd G, preferably 0 to 2 kg/cj G, for 10 minutes to 20 hours, preferably 0.5 to 10 hours.

The alkali-neutralized copolymer obtained by this neutralization treatment is the adhesive of the present invention. This product can be used as it is or dissolved in a solvent, and has excellent adhesive properties and is extremely effective for adhering various adherends, such as paper, wood, and plastics. In particular, it is very suitable as a rewetting adhesive such as glue used for stamps, stamps, etc., and as a paper 1 plywood circumferential adhesive.

The adhesive of the present invention is an alkali-neutralized product of isobutylene-maleic anhydride-vinyl acetate terpolymer;
An alkali neutralized product of a maleic anhydride-maleic acid mono- or di-alkyl ester-vinyl acetate quaternary copolymer can also have similar effects.

Next, the present invention will be explained in detail with reference to examples.

Example 1 60 g of maleic anhydride, 26.3 g of vinyl acetate.

0.8 g of benzoyl peroxide and 460 g of acetonitrile
cc was placed in a tz autoclave, and sufficiently cooled and degassed.

Next, add 37 g of isobutylene, 400 r, p, ■
The polymerization reaction was carried out at 110° C. for 2 hours with stirring. After the reaction was completed, the pressure was reduced to HH twice using an evaporator, and the solvent was distilled off at 90° C. over 3 hours to obtain an isobutylene-maleic anhydride-vinyl acetate terpolymer. The number average molecular weight of this product is 59,000, and the copolymerization ratio of each monomer is isobutylene repeating units: maleic anhydride repeating units: vinyl acetate repeating units = 1:1
:o, 5 (molar ratio).

50 g of the obtained copolymer was charged into a No. 11 glass autoclave together with an aqueous solution prepared by dissolving 26 g of sodium hydroxide in 258 g of water, and neutralization was performed while stirring at 90° C. for 6 hours. In this way, an aqueous solution of an alkali-neutralized terpolymer having a copolymer concentration of 15% by weight and a degree of neutralization of 1.0 was obtained.

The obtained aqueous solution was applied to a 25 x 1 width of kraft paper, and the adhesive layer was layered on another kraft paper to give an adhesive film thickness of 80 μm to prepare an adhesive test piece, which was left at 25° C. for 3 hours. Table 1 shows the results of measuring the 90'' peel adhesive strength of this product.

Example 2 In Example 1, isopropyl acetate was used as the solvent and the temperature was 55°C for 6 hours.
50 g of a copolymer was obtained in the same manner as in Example 1 except that the 1-polymer reaction was carried out. The number average molecular weight of this copolymer is 137
000, the copolymerization ratio (molar ratio) of each monomer is isobutylene: maleic anhydride: vinyl acetate - 1:0.7 = 0.3
Met. Next, this copolymer was neutralized in Example 1.
I did it in the same way. Table 1 shows the measurement results of the physical properties of this product.

Comparative example 1 60 g of maleic anhydride, 37 g of isobutylene.

Benzoyl peroxide 0.8g and n-hexane 460c
c II! The copolymerization reaction was then carried out at 110°C for 2 hours with stirring, and the solvent was distilled off to obtain a number average molecular weight of 27.
000, an isobutylene-maleic anhydride copolymer having a monomer copolymerization ratio of 1:1 was obtained.

50 g of the obtained copolymer was charged into an IX glass autoclave together with an aqueous solution of 26 g of sodium hydroxide dissolved in 257 g of water, and neutralized while stirring at 90° C. for 6 hours. In this way, the copolymer concentration 15
An aqueous solution of an alkali-neutralized copolymer having a weight % and a degree of neutralization of 1.0 was obtained.

The resulting aqueous solution was measured for its 90'' peel adhesive strength in the same manner as in Example 1. The results are shown in Table 1.

Chapter 1 Table

Claims (1)

[Claims] (1) An adhesive comprising an alkali neutralized product of isobutylene-maleic anhydride-vinyl acetate terpolymer.