JPH0464353B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a resin composition having good adhesive strength. More specifically, it is a polymer obtained by suspension graft polymerization of vinyl chloride or a monomer mixture mainly composed of vinyl chloride to an ethylene-vinyl acetate copolymer (hereinafter referred to as EVA).
Abbreviated as EVA/VC graftomer. ) and a petroleum resin. The purpose is to obtain a resin composition that has excellent adhesion to various materials such as organic polymer materials, metal/inorganic materials, and cellulose-based natural materials. In particular, the object of the present invention is to obtain a resin composition having excellent adhesion to films, sheets, and various molded articles made of saturated polyester. Conventionally, a huge number of techniques have been proposed for adhesives. Based on their main components, they can be broadly divided into natural product-based, inorganic-based, thermoplastic resin-based, thermosetting resin-based, and rubber-based. Furthermore, to summarize each system, natural products include starch, glue, natural rubber, rosin, etc., and inorganic products include water glass, silica sol, etc. In addition, thermoplastic resins include vinyl chloride resin,
Examples include vinyl acetate resin, polyvinyl alcohol, vinyl butyral resin, EVA, and acrylic resin, while thermosetting resins include phenol resin, urea resin, melamine resin, epoxy resin, and urethane resin. Examples of rubber include chloroprene rubber, nitrile rubber, styrene-butadiene rubber, butyl rubber, and silicone rubber. Adhesives began to be used in large quantities industrially in the manufacture of plywood, and subsequently, with the development of synthetic resins and synthetic rubbers, adhesives have grown dramatically. One of the synthetic resins closely related to such adhesives is polyester resin. Polyester resin has excellent mechanical strength, water resistance, and gas barrier properties, and is widely used as a laminate film for food packaging and retort pouches. On the other hand, since polyester resins have poor adhesive properties, hot-melt adhesives, film adhesives, and the like are currently unsatisfactory as adhesives, and methods such as dry lamination of polyurethane have had to be used. However, this method has many problems, such as insufficient adhesive strength and the use of a solvent, which poses problems such as air pollution and the risk of explosion, and the resulting film has a solvent odor. was. Furthermore, a method is known in which the surface of polyester resin is hydrolyzed with alkali to improve adhesion, but this method also requires large-scale equipment for hydrolysis, resulting in a significant increase in price. It was inevitable. As described above, hot melt adhesives and film adhesives for polyester resins are not well known at present, and their appearance has been awaited. The present inventors were investigating a method to improve the adhesive performance of EVA/VC graftomer, and surprisingly found that by mixing EVA/VC graftomer and petroleum resin in a specific ratio, it was possible to improve the adhesion performance of polyester resin. It was found that the adhesive had extremely high adhesion performance. Furthermore, it was discovered that the composition of the present invention has high adhesion performance to other materials such as aluminum, and the present invention was achieved based on this finding. That is, the present invention has a vinyl acetate content of 1 to 60% by weight.
Polymer obtained by suspension graft polymerization of more than 40 parts by weight and less than 95 parts by weight of EVA with 5 parts by weight or more and less than 60 parts by weight of vinyl chloride or a monomer mixture mainly composed of vinyl chloride (EVA/VC graftomer) 40 140 parts by weight or more and 95 parts by weight or less of cracked oil fractions obtained by thermal decomposition of petroleum, etc.
This is an adhesive resin composition comprising 5 parts by weight or more and 60 parts by weight or less of a petroleum resin obtained by polymerizing a boiling point fraction within the range of ~220°C in the presence of a Friedel-Crafts type catalyst. The present invention will be explained in detail below. The EVA used in the present invention is manufactured by either a high-pressure radical polymerization method or a solution or emulsion polymerization method, and has a vinyl acetate content of 1 to 60% by weight and a melt index (MI).
is preferably 0.1 to 500 g/10 minutes, and commercially available EVA that satisfies this condition can be used. The EVA/VC graftomer used in the present invention is preferably one obtained by suspension graft polymerization of 5 parts by weight or more and less than 60 parts by weight of vinyl chloride with more than 40 parts by weight of the above-mentioned EVA and 95 parts by weight or less. Suspension graft polymerization involves a method in which EVA is dissolved in vinyl chloride using an organic peroxide as an initiator, and then graft polymerized, or a production technique disclosed in Japanese Patent Publication No. 16346/1983, etc. A method can be used in which EVA is graft-polymerized in a swollen state without dissolving it in vinyl chloride under a pressure lower than the above pressure. When the amount of graft polymerization exceeds 60 parts by weight, or when the vinyl acetate content of EVA as the backbone polymer is less than 1% by weight, the adhesiveness of the composition of the present invention is significantly reduced. Also, when the amount of graft polymerization is less than 5 parts by weight, or when the vinyl acetate content of EVA, which is the backbone polymer, exceeds 60% by weight,
EVA/VC graftomers tend to stick to processing machines, etc., which is inconvenient. The petroleum resin used in the present invention is obtained by polymerizing a fraction with a boiling point in the range of 140 to 220°C in the presence of a Friedel-Crafts type catalyst among cracked oil fractions obtained by thermal decomposition of petroleum. At least one of them can be used, and commercially available petroleum resins that meet this condition, such as Neopolymer (product of Nippon Petrochemicals Co., Ltd.) and Petrozine (product of Mitsui Petrochemicals Co., Ltd.) , Petcol (Toyo Soda Kogyo Co., Ltd. product)
can be used. The quantitative ratio of EVA/VC graftomer and petroleum resin in the composition of the present invention is determined by comprehensively considering its melt viscosity, processability, mechanical strength, and other factors in relation to the specific use of the resin composition. It can be decided by Specifically, the petroleum resin is preferably 5 parts by weight or more and 60 parts by weight or less relative to 40 parts by weight or more and 95 parts by weight or less of the EVA/VC graftomer. This is because within this range, a resin composition with improved adhesiveness can be obtained and has properties that can be used in extrusion coating resins, films, and adhesives. As described above, the composition of the present invention is particularly effective as an adhesive between polyester and polyester or between polyester and other materials. Furthermore, it can be used as an adhesive between aluminum and aluminum or aluminum and other metals, and can be applied to a wide range of applications. The composition of the present invention can be used in either a film or pellet form to effectively exhibit its effects. Needless to say, it can also be used as a film (sheet) or a multilayer film (sheet) by coating other materials (especially polyester resin). Depending on the type of use, known additives such as heat stabilizers, antioxidants, anti-blocking agents, slip agents, antistatic agents, colorants, etc. may be added. Inorganic fillers can also be added to the composition of the present invention within a range that does not impair its effectiveness. These components can be kneaded by a known method such as a Banbury mixer, a two-roll mill, or an extruder. The kneading temperature is determined in relation to the melting point and decomposition temperature of the EVA/VC graftomer and the melting point and decomposition temperature of the petroleum resin. Specifically, the temperature is preferably 100°C or higher and 200°C or lower. The kneading time may be selected so as to provide a uniformly mixed resin composition. Specifically, 5 minutes or more is suitable. As described above, the composition of the present invention is particularly useful as an adhesive for polyester resins, and its contribution to industries including packaging materials is extremely large. EXAMPLES The present invention will be specifically explained below with reference to Examples, but the present invention is not limited in any way. Reference example 1 Production of EVA/VC graftomer (A) In a 70 stainless steel vinyl chloride polymerization vessel equipped with a stirring device, add 40 kg of pure water and EVA (melt index 30 g/10 minutes, vinyl acetate content 32% by weight)5
After charging 50 g of partially saponified polyvinyl acetate, closing the lid and purging with nitrogen, vacuum was applied and 1.5 kg of vinyl chloride monomer was introduced. The temperature was started to rise while stirring, and when the temperature reached 60°C, 5 g of 2,2'-azobis-2,4-dimethylvaleronitrile was added to initiate polymerization. Pressure 5Kg/cm ²
Polymerization was carried out for 8 hours while introducing vinyl chloride monomer to maintain a constant G, and EVA was 81.7% by weight.
EVA/VC graftomer (A) was obtained and used in the following examples. Reference example 2 Production of EVA/VC graftomers (B) and (C) In a 70 stainless steel vinyl chloride polymerization vessel equipped with a stirring device, add 27 kg of pure water, EVA (melt index 30 g/10 minutes, vinyl acetate content 32 weight) %)9.0
After charging the reactor with 50 g of partially saponified polyvinyl acetate, closing the lid and purging with nitrogen, the reactor was evacuated and 9.0 kg of vinyl chloride monomer was introduced. The temperature was started to rise while stirring, and EVA was dissolved in the vinyl chloride monomer at 60°C for 3 hours. Then, 2,2′-azobis-
5 g of 2,4-dimethylvaleronitrile was added to start polymerization, which was carried out for 8 hours to obtain an EVA/VC graftomer (B) containing 62.5% by weight of EVA. EVA/VC graftomer (C) containing 30% by weight of EVA was obtained in the same manner and used in the following examples. Examples 1-1 to 1-5, Comparative Examples 1-1 to 1-2 Using a 6-inch roll, at 130°C Reference Example 1,
Stabilizer #N-2000E (manufactured by Nitto Kasei Co., Ltd.), E-
101 (manufactured by Tokyo Fine Chemical Co., Ltd.), a composition containing 2 parts by weight of each was melted, a predetermined amount of petroleum resin was added, and the mixture was kneaded for 5 minutes. As the petroleum resin, Petcol 140 manufactured by Toyo Soda Kogyo Co., Ltd. was used. This composition was made into a 0.1 mm film, sandwiched between 0.3 mm polyester resin, 150°C, 100Kg/cm ² ,
Thermocompression bonding was carried out for 5 minutes, and the T-peel strength was measured. The results are shown in Table 1. Examples 2-1, 2-2 Using a 6-inch roll, 70 parts by weight of the EVA/VC graftomer (A) produced in Reference Example 1 was added to 2 parts by weight each of stabilizers #N-2000E and E-101 at 130°C. After melting the composition, 30 parts by weight of petroleum resin was added and kneaded for 5 minutes. This composition was made into a 0.1 mm film, and a 0.3 mm aluminum plate and a 0.3 mm aluminum plate and a 0.3 mm film were formed.
It was sandwiched between iron plates and thermocompression bonded at 150° C., 100 kg/cm ² for 5 minutes, and its T-peel strength was measured. The results are shown in Table 1. Comparative Examples 2-1 to 2-2 Using a 6-inch roll, at 130°C Reference Example 1,
EVA/VC graftomers (A) and (B) produced in 2.
A composition prepared by adding 2 parts by weight each of stabilizers #N-2000E and E-101 to 100 parts by weight was melted and then kneaded for 5 minutes. This composition was made into a 0.1 mm film, sandwiched between 0.3 mm polyester resin, 150°C, 100Kg/cm ² , 5
The T-peel strength was measured by thermocompression bonding under conditions of 1 minute. The results are shown in Table 1. Comparative Example 3-1 Composition in which 2 parts by weight each of stabilizers #N-2000E and E-101 were added to 70 parts by weight of the EVA/VC graftomer (C) produced in Reference Example 2 at 130°C using a 6-inch roll. After melting the material, 30 parts by weight of petroleum resin was added and kneaded for 5 minutes. This composition was made into a 0.1 mm film, sandwiched between 0.3 mm polyester resin, 150°C, 100Kg/cm ² ,
Thermocompression bonding was carried out for 5 minutes, and the T-peel strength was measured. The results are shown in Table 1.

【table】

[Table] *1 Toyo Soda Kogyo Co., Ltd. product *2 Nitto Kasei Co., Ltd. product *3 Tokyo Fine Chemical Co., Ltd. product As is clear from the results in Table 1, the adhesive resin composition of the present invention It is found that it is extremely effective as an adhesive for polyester resins and metals.

Claims (1)

[Claims] 1. An ethylene-vinyl acetate copolymer with a melt index of 0.1 to 500 g/10 minutes and a vinyl acetate content of 1 to 60% by weight. 40 parts by weight or more of a polymer obtained by suspension graft polymerization of 5 parts by weight or more but less than 60 parts by weight of the main monomer mixture95
2 parts by weight or less Petroleum resin obtained by polymerizing a boiling point fraction within the range of 140 to 220°C among cracked oil fractions obtained by thermal decomposition of petroleum in the presence of a Friedel-Crafts type catalyst An adhesive resin composition comprising 5 parts by weight or more and 60 parts by weight or less.