JPS5940859B2 - adhesive composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to adhesive compositions, and more particularly to improved adhesive compositions that have strong adhesion to both metals, glass, ceramics, and polyolefins. be.

Polyolefins such as polyethylene and polypropylene have no polarity in their molecules and are highly crystalline, so it is generally difficult to bond them to metals.

For this reason, there is currently a demand for adhesives that have strong adhesion to both polyolefins and metals in various applications.As such adhesives, adhesives obtained by hydrolyzing ethylene-methacrylate copolymers are being used. Copolymers containing carboxyl groups and mainly consisting of ethylene such as ethylene-maleic acid copolymers (Japanese Patent Publication No. 42-6178), and DuPont's Surlyn 16
52 Tau Chemical Company's ZetaFax No. 1680 is known.

However, these adhesives are still insufficient for certain uses, such as the production of laminated sheathed cables, and there is a desire for adhesives with even higher adhesive performance. In other words, adhesives such as Surlyn and Zedafax cannot be said to have satisfactory adhesion to metals, and in particular, they have insufficient adhesion to polyolefins, while ethylene has good adhesion to polyolefins. There are vinyl acetate copolymers and ethylene/acrylic acid ester copolymers, but these have extremely poor adhesion to metals.

Therefore, when actually adhering metal and polyolefin firmly, it is necessary to compensate for the shortcomings of each, for example,
A method using a two-layer film made by laminating Surlyn and an ethylene/vinyl acetate copolymer, and a method of first applying Surlyn to a metal surface and then applying an ethylene/vinyl acetate copolymer have been devised.

However, these methods have the drawback of requiring complicated and economically disadvantageous steps such as forming a two-layer film and applying two coats.

The present inventors have conducted intensive research to improve the shortcomings of conventional adhesives and develop adhesives that can firmly adhere to both metals and polyolefins.
, copolymers with β-unsaturated carboxylic acids, or terpolymers of ethylene, α, β-unsaturated carboxylic acids, and unsaturated esters with certain aromatic hydrocarbon resins or hydrocarbon resins containing halogens. The present invention was completed based on the discovery that the adhesion of polyolefins to both metals and glass ceramics can be greatly improved by blending them. That is, an object of the present invention is to provide a novel adhesive composition that has strong adhesion to both polyolefin and metals, glass, and ceramics.

The present invention provides (4) unsaturated carboxylic acid monomers selected from ethylene (a) and α,β monounsaturated carboxylic acids, their anhydrides, and α,β monounsaturated carboxylic acid glycidyl esters (
The first invention is an adhesive composition obtained by mixing (B) a vinyl aromatic hydrocarbon polymer or a halogenated ethylene polymer with a copolymer consisting of (4) ethylene (a).
) and α,β monounsaturated carboxylic acids, their anhydrides and α,
A terpolymer consisting of an unsaturated carboxylic acid (b) selected from β-monounsaturated carboxylic acid glycidyl ester and an unsaturated ester (c), and (B) a polymer of vinyl aromatic hydrocarbon or halogenated ethylene A second invention is an adhesive composition obtained by mixing the following polymers.

The ethylene copolymer used in the first aspect of the present invention is an unsaturated carboxylic acid monomer obtained from ethylene, α,β-monounsaturated carboxylic acid, its anhydride, and α,β-monounsaturated carboxylic acid glycidyl ester. It is obtained by copolymerizing the polymer with a polymer by a known method such as high-pressure radical polymerization or emulsion polymerization.

In the present invention, the α,β monounsaturated carboxylic acids and their anhydrides to be copolymerized with ethylene include atarylic acid, methacrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, citraconic acid, and maleic anhydride. Examples include acids, itaconic anhydride, citraconic anhydride, etc.
Examples of the monounsaturated carboxylic acid glycidyl ester include glycidyl acrylate and glycidyl methacrylate. In order to obtain good adhesive strength in this first invention crude product, the content of unsaturated carboxylic acids in the copolymer is preferably 0.1 to 2.0 mol%, particularly 1 to 10 mol%.

Among the above-mentioned copolymers of ethylene and unsaturated carboxylic acids, particularly preferred copolymers include ethylene-acrylic acid copolymers and ethylene-methacrylic acid copolymers.

Further, in the first invention, a modified product obtained by ionically crosslinking the above-mentioned copolymer of ethylene and unsaturated carboxylic acids with a metal salt can also be used as the prisoner component.

In the second invention of the present invention, as the component (4), ethylene,
The unsaturated carboxylic acids used in the above first invention,
Further, as a third copolymerization component, a terpolymer obtained by adding an unsaturated ester and copolymerizing is used. In this second invention, by using a terpolymer obtained by adding and copolymerizing an unsaturated ester as the third copolymerization component,
A composition having adhesive strength to metals and polyolefins equal to or higher than that of the composition of the first invention can be obtained. Examples of the unsaturated entele as the third copolymerization component in the second invention include vinyl esters such as vinyl acetate and vinyl propionate, and unsaturated carboxylic acid esters such as methyl acrylate, ethyl acrylate, and methyl methacrylate. Among these, preferred ternary copolymers in the second invention include ethylene-methacrylic acid monovinyl acetate copolymer, ethylene-acrylic acid monovinyl acetate copolymer, ethylene-glycidyl acrylate monovinyl acetate copolymer, Examples include ethylene-glycidyl methacrylate monovinyl acetate copolymer. As the above terpolymer, in the second invention composition, ethylene 60-
99 mol% unsaturated, carboxylic acids 0.1-20 mol%,
It is preferable to use a copolymer consisting of 1 to 20 mol% of unsaturated ester. The present invention focuses on the above-mentioned components, namely:
A copolymer of ethylene and unsaturated carboxylic acids, or a terpolymer of ethylene, unsaturated carboxylic acids, and unsaturated ENTEL, and a polymer of vinyl aromatic hydrocarbon or halogen substitution of ethylene as component (B). It can be obtained by blending the polymers of the body.

The vinyl aromatic hydrocarbon polymer used in the present invention is usually a single or copolymer of vinyl aromatic hydrocarbons having 8 to 20 carbon atoms, particularly 8 to 12 carbon atoms, and specifically, polystyrene, poly-alpha Examples include -methylstyrene, polyvinyltoluene, poly-β-methylnutylene, polyisopropenyltoluene, and polyTent-butylstyrene.

A particularly preferred vinyl aromatic hydrocarbon polymer in the present invention is polystyrene. Further, the halogenated ethylene polymer used in the present invention is a homopolymer of halogenated ethylene having the general formula (wherein X represents chlorine or fluorine, and RlR2R3 represents hydrogen, chlorine, or fluorine) or It is a copolymer, and specific examples include polymers of tetrafluoroethylene, trifluoroethylene, vinylidene fluorade, vinylfluoride, vinylidene chloride, vinyl chloride, or copolymers of the above-mentioned halogenated ethylene and ethylene. It will be done.

A particularly preferred halogenated ethylene polymer in the present invention is polytetrafluoroethylene. In addition, in the present invention, the amount of vinyl aromatic hydrocarbon or halogenated ethylene polymer is a copolymer of ethylene and unsaturated carboxylic acids or a terpolymer of ethylene, unsaturated carboxylic acids, and unsaturated ester. 1 to 50 per portion
parts, preferably 5 to 20 parts. The mixing method is not particularly limited, and known mixing techniques such as physical mixing of powdered materials and melt kneading using a Banbury mixer, mixing rolls, extruder, etc. can be used. The strong adhesion of the present invention to polyolefins and metals is due to (A) a copolymer of ethylene and unsaturated carboxylic acids, or a terpolymer of ethylene, an unsaturated carboxylic acid, and an unsaturated ester; ) It can only be obtained by blending both components, a polymer of vinyl aromatic hydrocarbon or a polymer of rogenated ethylene, and the adhesive strength of each component (A) and (B) alone is insufficient. or extremely low.

The adherends to be bonded with the composition of the present invention include metals such as aluminum, iron 6 copper, zinc, and tin, glass, ceramics, and polyethylene, polypropylene, ethylene-propylene copolymer, and ethylene monovinyl acetate copolymer. The composition of the present invention is particularly effective as an adhesive between metals and metals and between metals and polyolefins.

The method and conditions for bonding metals to metals or metals and polyolefins using the adhesive composition obtained by the present invention are not particularly limited, and the adhesive composition of the present invention can be used to bond metals to metals or metals to polyolefins. Simply insert the composition, heat above the melting temperature of the adhesive composition, and press.

In this case, the polyolefin may be in either a solid state or a heated molten state. Further, the form of the adhesive composition is not particularly limited, and it can be used in any convenient form such as powder, film, or sheet. Of course, it is also possible to extrude coat the metal or polyolefin surface in advance. The adhesive composition of the present invention may be used as it is, or if necessary, polyethylene, an ethylenically unsaturated ester copolymer, etc. may be mixed into the adhesive composition of the present invention.

The adhesive composition of the present invention has stronger adhesion to both metals and polyolefins than conventional adhesives.
Ceramics and polyolefin can be firmly bonded using a simple method.

The adhesive composition of the present invention can be used in various applications, such as bonding aluminum and polyethylene in packaging materials and laminated sheathed cables, and bonding aluminum and plywood, aluminum and honeycomb cores, etc. in building materials. It is valid. Next, the present invention will be specifically explained with reference to Examples, but the present invention is not limited thereto.

In the examples, all parts mean parts by weight. The methacrylic acid content in the copolymer was measured by dissolving the copolymer in xylene and titrating with alcoholic KOH using phenolphthalene as an indicator. The adhesion test was conducted using test pieces having a composition of aluminum/adhesive 2/polyethylene and a composition of aluminum/adhesive/aluminum, and was evaluated by peeling off the adhesive at 180.

All test pieces were made by bending aluminum 200mm/
It was peeled off at the tensile speed of Mln. The aluminum used was soft aluminum with a thickness of 200μ, and the polyethylene was made of Mitsui Polychemicals' Mirason 1250BK with a thickness of 2.
A sheet of m1 was used. The adhesive was previously formed into a sheet with a thickness of 100μ using a heat press.
This was done by thermocompression bonding for 3 minutes. Example 1 Melt index 3.7, methacrylic acid content 5.
100 parts of 5 mol% ethylene-methacrylic acid copolymer and polystyrene (Toyo Polystyrene Co., Ltd. Topolex 5)
00) 15 parts, and using an extruder, the resin temperature was 160
The mixture was melt-kneaded at ℃ and granulated.

As a result of measuring the adhesive strength of the obtained adhesive composition, the peel strength between aluminum and polyethylene was 3.8 kg/C.
Peeling strength between IrLl aluminum is 4.6kg
/CTrL. Example 2 A sample was prepared and tested in exactly the same manner as in Example 1, except that 15 parts of polystyrene in Example 1 was replaced with 5 parts of polytetrafluoroethylene (Teflon 7J manufactured by Mitsui Fluorochemicals).

As a result, the peel strength between aluminum and polyethylene was 4.31<g/CWL, and the peel strength between aluminum was 4.9 kg/CrIL. Comparative Example 1 The degree of adhesion was measured for the case in which polystyrene was not blended in Example 1. As a result, the peel strength between aluminum and polyethylene was 1.7 kg/the peel strength between CRL and aluminum was 2.3 kg/α.

Example 3 15 parts of polystyrene (Topolex 500) was blended with 100 parts of a Zn ion crosslinked product of ethylene-methacrylic acid copolymer (Surlyn 1652 manufactured by DuPOnt) with a melt index of 4.4, and the resin temperature was adjusted using an extruder. 16
The mixture was melted and kneaded at 0°C and granulated.

As a result of measuring the adhesive strength of the obtained adhesive composition, the peel strength between aluminum and polyethylene was 4.2 kg/C.
The peeling strength of ml aluminum is 4.5kg/?
It was hot. Example 4 A sample was prepared and tested in exactly the same manner as in Example 3, except that 15 parts of polystyrene in Example 3 was replaced with 5 parts of Teflon.

As a result, the peel strength between aluminum and polyethylene was 4.1 kg/C7rLl, and the peel strength between aluminum was 4.4 kg/CTn. Comparative example 2 Example 3
As a result of measuring the adhesive strength in the case where polyethylene was not blended, the peel strength between aluminum and polyethylene was 2.3 kg/Cm, and the peel strength between aluminum and aluminum was 2.5 kg/Cm.

Example 5 Melt index 4.

6, polystyrene (Topolecnu 5
00) 15 parts, and using an extruder, the resin temperature was 160
The mixture was melt-kneaded at ℃ and granulated.

As a result of measuring the adhesive strength of the obtained adhesive composition, the peel strength between aluminum and polyethylene was 4.8 kg/C.
Peeling strength between WL aluminum is 5.2kg/C
It was ITL. Example 6 Example 5 except that 15 parts of polystyrene in Example 5 was replaced with 5 parts of Teflon.
It was prepared and tested in exactly the same way.

As a result, the peel strength of aluminum and polyethylene was 5.3 kg/CTrL. Comparative Example 3 In Example 5, when polystyrene was not blended, the adhesive strength was measured and the peel strength between aluminum and polyethylene was 2.21<g/CTIL1, and the peel strength between aluminum was 2.8 kg/C7rl.

Example 7 15 parts of polystyrene was blended with 100 parts of ethylene-glycidyl methacrylate monovinyl acetate terpolymer with a melt index of 7 and a glycidyl methacrylate content of 3.0 mol% and a vinyl acetate content of 2.3 mol%, and after extrusion. The mixture was melt-kneaded at a resin temperature of 160° C. and granulated.

As a result of measuring the adhesive strength of the obtained adhesive composition, the peel strength between aluminum and polyethylene was 4.3k9/C.
Peeling strength between TrLl aluminum is 4.7kg
/? It was hot. Example 8 A sample was prepared and tested in exactly the same manner as in Example 7, except that 15 parts of polystyrene in Example 7 was replaced with 5 parts of Teflon.

As a result, the peel strength between aluminum and polyethylene was 4.6 kg/0 m, and the peel strength between aluminum was 4.5 kg/Cm. Comparative Example 4 In Example 7, when polystyrene was not blended, the adhesive strength was measured and the peel strength between aluminum and polyethylene was 2.7k9/CrL1.The peel strength between aluminum was 2.6k9/CTII.

Claims (1)

[Claims] 1 (A) Ethylene (a) and α. β-unsaturated carboxylic acid, its anhydride, and α. Unsaturated carboxylic acid monomer selected from β-unsaturated carboxylic acid glycidyl ester (b
An adhesive composition prepared by mixing a copolymer consisting of () with a polymer of vinyl aromatic hydrocarbon or a polymer of halogenated ethylene. Unsaturated carboxylic acid monomer (b) selected from acids, their anhydrides, and α.β-unsaturated carboxylic acid glycidyl esters
and unsaturated ester (c) (B
) An adhesive composition prepared by mixing a vinyl aromatic hydrocarbon polymer or a halogenated ethyl polymer.