JPS5947273A - Adhesive for paper/aluminum foil - Google Patents

Abstract

PURPOSE:To provide a water-emulsion type adhesive for paper/aluminum foil excellent in heat-bondability, by incorporating a copolymer emulsion yielded by emulsion polymn. of a mixture having a plastic substance blended in a specific monomer compsn. CONSTITUTION:59-85wt% one or more kinds of styrene, (meth)acrylonitrile, and methacrylate ester, 14-31wt% acrylate ester, and 1-10wt% alpha,beta-unsatd. carboxylic acid are blended. 100pts.wt. resulting monomer blend is mixed with 10-25pts.wt. phthalate ester or citrate ester. The resulting mixture is subjected to emulsion polymn. by a conventional method, yielding an adhesive for paper/ aluminum foil comprising a copolymer emulsion. A water-soluble high-molecular compd. may be optionally added during polymn. process to improve coatability.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water-based emulsion type paper-aluminum foil adhesive having excellent heat-resistant adhesive properties.

Conventional paper-aluminum foil water-based adhesives have poor heat-resistant adhesion properties, resulting in wrinkles after lamination, which poses a practical problem.

As a result of intensive research in order to improve these drawbacks, the present inventor found that (59 to 85% by weight of one or more of 1,1 styrene, (meth)acrylonitrile, and methacrylic acid ester)
, (2) 14 to 31% by weight of acrylic ester, and (
3) 10 parts of α,β-unsaturated unsaturated carboxylic acid, (4) 1 part of phthalate or citric acid ester
We discovered that a copolymer emulsion obtained by emulsion polymerization of a mixture containing 0 to 25 parts by weight (hereinafter referred to as the copolymer emulsion) has extremely excellent heat-resistant adhesive properties, and we have published this book. The invention was completed. The present invention will be explained in detail below.

A feature of the present invention is a copolymer emulsion obtained by emulsion polymerization of a mixture in which a plastic material is blended with a monomer composition of (1)%. In this case, it is difficult to obtain the desired high heat-resistant adhesive properties with adhesives in which a plastic material is blended into a copolymer emulsion obtained by emulsion polymerization of a specific monomer composition. The reason for this is not clear, but when a plastic substance is blended after emulsion polymerization, the compatibility between the plastic substance and the copolymer resin is insufficient than when the plastic substance is blended during emulsion polymerization, so It is thought that the migration of the particles has a significant adverse effect on adhesion.

(2) By introducing acrylic acid esters with excellent cross-linking reactivity, such as polyethylene glycol dialgylate, into the monomers styrene and (meth)acrylonitrinope methacrylate that constitute the hard polymer, paper-aluminum Adhesion to both sides of the foil is improved, and in particular, thermal adhesion is significantly improved.

(1) One of styrene, (meth)acrylonitrile, and methacrylic acid ester, or (meth)acrylonitrile in 21i1i and above includes methacrylonitrile, acrylonitrile, and the like.

Examples of methacrylic esters include methyl methacrylate, ethyl methacrylate, and butyl methacrylate. The amount used is 59 to 85% by weight, and if it is less than 59% by weight, the heat-resistant adhesion will be poor, and if it exceeds 85% by weight, the coating will be too hard and the adhesion will be poor.

(2) Acrylic esters include acrylic methyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, glycidyl acrylate, glycidyl methacrylate, polyethylene glycol dimecrylate-1-, polyethylene glycol diethacrylate, polyethylene glycol dibutafrylate, Examples include polyethylene clinyl di-2-ethylhexylate. The amount used is 1/1
-31% by weight; if it is less than 14% by weight, the coating film will be too hard, resulting in poor adhesion and poor heat-resistant adhesion; if it exceeds 31% by weight, heat-resistant adhesiveness will deteriorate.

(3) The β-unsaturated carboxylic acid improves adhesion to aluminum foil, and examples thereof include acrylic acid, methacrylic acid, crotonic acid, maleic acid, and fumaric acid. The amount used is 1 to 10% by weight, and if it is less than 1% by weight, the heat-resistant adhesiveness will be poor, and if it exceeds 10% by weight, the water-resistant adhesiveness will be poor, which is not preferred.

Hereinafter, the mixed monomers (1) to (3) will be referred to as the mixed monomers.

In addition, a phthalate ester or a citric acid ester is necessary to plasticize the copolymer of (11 to (3)), and the phthalate ester is diethyl phthalate, dibutyl phthalate, dioctyl phthalate, butyl phthalate. - Examples include benzyl.

Examples of citric autoesters include acetyl monobutyl tributyl citrate.

The amount used is 10 parts by weight per 100 parts by weight of the mixed monomer.
-25 parts by weight, and if it deviates from this range, the heat-resistant adhesiveness will be poor, so it is not preferable.

Further, the copolymer emulsion is produced by a conventional emulsion polymerization method. That is, an anionic surfactant as an emulsifier,
Examples include higher alcohol sulfates, alkylbenzene sulfonates, alkylphenyl polyoxyethylene sulfates, and nonionic surfactants such as polyoxyethylene alkyl esters, polyoxyethylene alkyl ethers, and polyoxyethylene alkylphenyl ethers. One or more of these may be used. A persulfate such as potassium persulfate or ammonium persulfate is used as the catalyst, and the mixed monomer and a mixture of 5- and citric acid ester or phthalate ester are added sequentially to react at about 40 to 90°C. Emulsion polymerization is carried out over 9 hours to obtain the copolymer emulsion.

At this time, in order to increase the viscosity and improve the coating properties, a water-soluble polymer compound such as side-lighting material such as POVAL, CMC, HEC, etc. may be added during the polymerization step, as the case may be.

Furthermore, preservatives and antifungal agents may be used as other additives.

The paper typically used is tissue paper, parchment paper, high-quality paper, or paperboard. The copolymer emulsion is applied to aluminum foil or paper using a roll coater or the like. Specifically, it is preferably applied to food packaging, such as packaging for butter and margarine, and building materials, such as fusuma paper and cosmetic packaging. Examples and comparative examples of the present invention are shown below.

Note that divisions and divisions refer to weight standards.

Example 1.

A polymerization can was charged with 27 parts of water and 03 parts of alkylbenzene sulfonate, and to this were added 166 parts of water, 2 parts of polyoxyethylene nonylphenyl ether (number of moles added to holoxyethylene: 16), 24 parts of styrene, and 2 parts of acrylic acid.
- A mixed dispersion of 8 parts of ethylhexyl, 1 part of polyethylene glycol dimethacrylate, 3 parts of glycidyl methacrylate, 2 parts of acrylic acid, and 8 parts of acetyl tributyl citrate and a solution of 0.1 part of ammonium persulfate and 2 parts of water at 85°C. The emulsion polymerization was carried out over a period of 4 hours, followed by neutralization with ammonia (to obtain a copolymer emulsion with a solid content of about 50%, a viscosity of 2,000 cps, and a pI of 8.0).

This was applied to aluminum foil using a bar coater station 8, and high-quality paper was pasted and pressed using a rubber roller. After drying at 100°C for 1 minute, the adhesion, water-resistant adhesion, and heat-resistant adhesion were measured, and these are shown in Table 1. summarized in.

Example 2゜In Example 1, only 24 parts of styrene was replaced with 24 parts of acrylonitrile.
Emulsion polymerization was carried out in the same manner as in Example 1, with the solid content being approximately 50% and the viscosity being 2,500 cp.
A copolymer emulsion with a pH of 8.5 was obtained. This was applied to aluminum foil under the same conditions as in Example 1, and its adhesion to paper was evaluated, and the results are summarized in Table 1.

Example 3゜In Example 1, only 24 parts of styrene was replaced with 2 parts of methyl methacrylate.
Emulsion polymerization was carried out in the same manner as in Example 1 except that the amount was changed to 4 parts, and the solid content was about 50% and the viscosity was 2.300 e p S, p
A copolymer emulsion of I(9,0) was obtained. This was applied to aluminum foil under the same conditions as in Example 1, and the adhesion to paper was evaluated. The results are summarized in Table 1.

Comparative Example 1゜ Polyethylene glycol dimethacrylate 1 in Example 1
When the amount of styrene was increased to 28 parts of styrene instead of using 3 parts of glycidyl methacrylate, the solid content was about 5 parts under the same emulsion polymerization conditions as in Example 1.
A copolymer emulsion having a coefficient of 0, a viscosity of 2,000 cps, and a pH of 9.0 was obtained. This was applied to aluminum foil under the same conditions as in Example] and the adhesion to paper was evaluated. Table 1 shows the results.

Comparative Example 2 Polyethylene glycol dimethacrylate-1-
Emulsion polymerization was carried out under the same conditions as in Example 1 using 2 parts of acetyltributyl citrate and 10 parts of 2-ethylhexyl acrylate, with the amount of styrene increased to 28 parts without using 1 part of glycidyl methacrylate and 3 parts of glycidyl methacrylate. The obtained copolymer emulsion had a solid content of about 48%, a viscosity of 2,000 cps,
p i (9.0) This was applied to aluminum foil under the same conditions as in Example 1, and the adhesion to paper was evaluated. Table 1 shows the results.

It is clear from Table 1 that the adhesive of the present invention has excellent adhesive properties, particularly heat-resistant adhesive properties.

= 9- Indetail S in Specification 3 (No change in content) Table 1 *Note (li +4 Note; Apply the emulsion to an aluminum vessel with bar coater 1168, and coat the parchment with J'
Paper polishing when combined with a gono roller at a pressure of 15 M at 100°C for 1 minute in a dry-cooking converter at 180°.

Evaluate the situation 1 (10,000.F): 100% paper...○ -A! ! +99~90%・・・・・・ΔExtra pressure (
A sample was prepared by laminating it with the same glue and 1- as described in note (1) in a converter, and it was heated to 20'Cte24>5. (, ;1 Wednesday y Kanza tscf'
The paper tear condition when peeling was done was evaluated in the same manner as the adhesiveness in Note (1).

*Note (3) Heat-resistant adhesiveness: A sample was prepared by laminating and drying under the same conditions as the adhesiveness of property (1) above, and this was
After heat-sealing with an iron at 250°C, the surface condition of the aluminum foil was observed and evaluated. In other words, there is no abnormality...○ Abnormalities such as pinholes and blisters occur...× Patent applicant Daicel Chemical Industries, Ltd. -11- Procedural amendment (method) % formula % ) 1. Indication of the case Patent Application No. 159392 filed in 1982 Furigana Kamirif Yosesochakutsui 2. Name of Invention 0 Paper-Aluminum Foil Adhesive Design Articles Designated Goods and Product Classification Class 3; Relationship with the case of the person making the amendment Patent applicant address Postal code 590 5. Subject of amendment Table 6 of the specification, Contents of amendment The table frame on page 10 of the specification is
(No change in content)

Claims (1)

[Scope of Claims] 10 to 2 parts of phthalate or citric acid ester per 100 parts by weight of the following monomers (1), (2), and (3)
A paper-aluminum foil adhesive comprising a copolymer emulsion obtained by emulsion polymerization of a mixture containing 5 parts by weight. (1) 59 to 85% by weight of one or more of styrene, (meth)acrylonitrile, and methacrylic ester (2) Acrylic ester/l/ 14 to 31
Weight article (3) α7β-dissonant carboxylic acid 1-1
0% by weight