JPS6026038A - Improved method for bonding polyolefin film or sheet - Google Patents

Abstract

PURPOSE:To facilitate the bonding of a polyolefin film with a high effect of adhesiveness improvement without causing lowering in mechanical strength, by sticking a polyolefin film through a layer contg. a polyolefin and an org. peroxide on the surface of an adherend and carrying out a crosslinking reaction. CONSTITUTION:A polyolefin film or sheet mainly composed of a polyolefin and contg. a component (a) capable of co-crosslinking with the polyolefin and a tert. amine or a metal salt (b) capable of undergoing a redox reaction with an org. peroxide, is sticked through a compsn. layer contg. an org. peroxide and a component (c) capable of co-crosslinking with component (a) and contg. a polar group, on the surface of an adherend, and a crosslinking reaction is carried out to bond them to each other. In the crosslinking reaction, the polyolefin of the film or sheet, component (a) and component (c) in the compsn. layer are co- crosslinked and the film or sheet is bonded to the compsn. layer by crosslinking. Since component (c) contains a polar group, the bonding of the film or sheet to the adherend is firmed as crosslinking proceeds.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a method for improving the adhesion of polyolefin films or sheets.

Generally, the adhesiveness of the poly(N-1) film or sheet is extremely low because the polyolefin is non-polar and crystalline. For this reason, various methods of improving adhesion have been proposed. For example, polar groups can be generated on the surface of a polyolefin film or sheet by chemical surface treatment with an acid-oxidizing agent mixture, corona discharge, ultraviolet irradiation, radiation irradiation, plasma jet, etc., or by mechanical polishing on the surface of the film or sheet. There are methods such as adding unevenness and hoping for an anchoring effect.

However, since the method using chemicals such as an acid-oxidizing agent mixture is a wet method, surface cleaning and drying are required after the treatment, resulting in a large number of treatment steps. Furthermore, methods using corona discharge or the like not only require expensive equipment, but also cannot be said to have sufficient treatment effects. In addition, the method of mechanical polishing requires large-scale equipment, and the processing effect is not sufficient.

In addition to these surface treatments, there is also a method of mixing a polar substance into polyolefin. However, this method has a problem in that the mechanical strength of the film or sheet decreases because the compatibility between the polyolefin and the polar substance is low.

Therefore, the present inventors developed a polyolefin film or sheet that does not require special equipment and has a large adhesion improvement effect, unlike the surface treatment method described above, and which does not reduce mechanical strength. As a result of intensive studies aimed at providing a method for improving adhesion, the present invention was completed.

That is, this invention uses polyolefin as a main component,
a) a component co-crosslinkable with this polyolefin and b)
A composition containing a polyolefin film or sheet containing a metal salt or tertiary amine that can undergo a redox reaction with an organic peroxide, and C) a component having a polar group that can be co-crosslinked with the polyolefin or three components and an organic peroxide. When cross-linked at room temperature through a layer and attached to the surface of the adherend (a)
This invention relates to a polyolefin-based film characterized in that it can be adhered to a polyolefin film.

According to the method of the present invention, when the polyolefin film or sheet C4 is attached to the adherend surface via the composition layer containing an organic peroxide, the organic peroxide and the film or sheet are bonded together. (1) It quickly crosslinks at room temperature due to the action with the component. In this crosslinking, the polyolefin in the film or sheet and the component a are co-crosslinked, and the component C in the composition layer is also co-crosslinked.
The polyolefin film or sheet and the composition layer are bonded together by crosslinking. In addition, since this component C contains a polar group, the composition layer adheres well to the adherend or to the abuseable adhesive applied to the adherend, and as crosslinking progresses, it forms a polyolefin film or sheet. The adhesion to the adherend becomes stronger.

As described above, in the method of the present invention, since the polyolefin film or sheet is crosslinked, it also has excellent mechanical strength.

Further, according to the method of the present invention, no special equipment is required, and the composition layer is simply applied to the polyolefin film or sheet or adherend as an adhesive, or as a primer to the film or sheet. This is a very simple method.

The polyolefins used in the process of this invention may include monopolymers such as polyethylene, polypropylene, polybutene, or copolymers such as ethylene-propylene copolymers.

As the component (component a) that can be co-crosslinked with these polyolefins, it is preferable to select a component that has good compatibility with the polyolefin, such as ethylene-propyref-nonconjugated genter polymer, chlorosulfonated polyethylene, ethylene-vinyl acetate copolymer. (Bound vinyl acetate amount 5-30%)
, chlorinated polyethylene, etc. can be used. Further, together with these polymer components, a polymer such as (meth)acrylic acid or (meth)acrylic acid ester, which will be used as component C (not shown later), may be used in combination.

The b component contained in the polyolefin film or sheet together with these polyolefins and the a component is gold 1m salt or 3
Each of the class amines may be used alone, or a mixture of these may be used. As this metal salt, salts of cobalt, copper, iron, nickel, etc. are used, and preferred ones include cobalt naphthenate, cobalt chloride, cuprous chloride, ferrous chloride, nickel chloride, and manganese salts. be able to. Examples of the tertiary amine include diethyl-p-toluidine, dimethylaniline, dimethyl para-1-luidine, and diisopropanol-p-toluidine.

The blending ratio of the polyolefin in item 1, component a, and component A is 5 to 50 parts by weight, preferably 10 to 30 parts by weight of the three components, per 100 parts by weight of the polyolefin.
The content of the component is preferably in the range of 0.1 to 10 parts by weight, preferably 0.5 to 5.0 parts by weight.

In the method of the present invention, the polyolefin film or sheet contains at least the components listed in -1-, but in addition to these components, a small amount of a tackifier having good compatibility with the polyolefin may also be included.

In addition, fillers, lubricants (stearic acid, etc.), softeners (polybutene, process oil, etc.), etc. may be included.

The composition layer interposed between the polyolefin film or sheet and the adherend is a component that can be co-crosslinked with the polyolefin or component a using an organic peroxide, and has a polar group-containing component (component C) and an organic Contains peroxide.

As this C component, ethylene-vinyl acetate copolymer (
Polymers that can be co-crosslinked and have polar groups such as chlorosulfonated polyethylene, nitrile-butadiene rubber, chloroprene rubber, acrylic rubber, etc.; ethylene-propylene-nonconjugated genter polymers; Polymers that can be co-crosslinked but do not have polar groups such as natural rubber, styrene-butadiene rubber, butadiene rubber, (meth)acrylic acid, or esters of these acids with monohydric alcohols having 1 to 14 carbon atoms. , 2-hydroxyethyl (
(meth)acrylate 1mate, glycidyl (meth)acrylate, chloroethyl (meth)acrylate, etc.
Among monomers having polar groups such as acrylic esters, at least 1% of polymers are selected so that the polymer content is at least 50% by weight and about 0.1 to 30% by weight of polar groups is included.
Use seeds.

The organic peroxide used is one that crosslinks the polyolefin film or 6J sheet at room temperature by undergoing an oxidation-reduction reaction with component b contained in the polyolefin film or sheet. Examples of such organic peroxides include di-r silver oxides such as benzoyl peroxide and lauroyl peroxide, and hydroperoxides such as tetramethylphthyl hydroperoxide and cumene hydroperoxide. Also, ketone peroxides such as cyclohexanone peroxide and methyl ethyl ketone peroxide may be used. The blending ratio of component C and organic peroxide is preferably such that the amount of organic peroxide is in the range of 0.1 to 5 parts by weight per 100 parts by weight of component C.

Further, in addition to the above-mentioned components, a tackifier such as a petroleum-based hydrocarbon resin may be added to this composition layer. The blending ratio of this tackifier is usually 5 to 100 parts by weight of component C.
The amount is preferably in the range of 50 parts by weight.

These component C, organic peroxide, tackifier, etc. are dissolved in an organic solvent such as toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, etc. to form a composition solution of usually about 5 to 30% by weight.

This composition solution is used so that the organic peroxide in this solution is 0.5 to 10 parts by weight per 100 parts by weight of component 1 in the polyolefin film or sheet to be used. Bacteria after coating and drying on a film, sheet, or adherend surface are usually 5 to 309/
yyf, and this film or C;l sheet is bonded to an adherend. Alternatively, the composition solution is applied to a polyolefin film or sheet, and a pressure-sensitive adhesive is applied to the coated surface or the adherend surface to attach the film or sheet to the adherend. May be combined. The pressure-sensitive adhesive used at this time is preferably an acrylic resin type, natural rubber type, synthetic rubber type, etc.
It is preferable to contain the same metal salts or tertiary amines as mentioned above in an amount of about 0.5 to 15% by weight.

The polyolefin film or sheet laminated in this way will crosslink by simply leaving it at room temperature,
After 7 days, the peel strength was 1.80 (sample width 25mm, tensile speed 3QQmm 1 minute) and 3 to 7 kQ/25 m.
Shows adhesion of about m width. Furthermore, in terms of mechanical strength, it is not inferior to films or sheets made solely of polyethylene, which is the main component, and is actually improved because it is crosslinked.

The method of the present invention can also be applied to the case where polyolefin films or sheets are laminated to form a laminated film or sheet.

Examples of this invention will be described below. In addition, in the following, parts mean parts by weight.

Example 1 Polyethylene 100 parts Ethylene-propylene-dicyclopentadiene terpolymer 20 parts Cobalt naphthenate 0.5 parts The above blended composition was formed into a film with a thickness of about 0.05 mm by extrusion processing to obtain a polyethylene film. Buko.

Ethylene-vinyl acetate copolymer 5 parts Ethylene-propylene-dicyclopentadiene terpolymer 15 parts Benzoyl peroxide 2 parts Escorets 1202U (manufactured by Exon) Petroleum hydrocarbon + (l 1 fat) 10 parts Toluene 68 parts Above blended silk・≠The thickness of the fabric dryer or 0.05 mm
A cloth was placed on an aluminum plate in such a manner that the polyethylene film described in -1- was attached to the coated surface and left at room temperature.

Example 2 1.00 parts of polyethylene, 30 parts of lorosulfonated boliena, 1 part of cobalt chloride.
．． A polyethylene film was obtained by molding it into a film having a thickness of 100 mm.

Chlorosulfonated polyethylene 1 part Fat 1/10 parts Cyclohexanone peroxide 3 parts Hyresin 60
(Petroleum-based aromatic hydrocarbon resin manufactured by Toho Chemical Co., Ltd.) 10 parts Toluene 67 parts The blended composition described in 1 above was applied to one side of the polyethylene non-film described in 1 above so that the thickness after drying was 0.05 mm. Afterwards, approximately 0.0% of a synthetic rubber-based pressure-sensitive adhesive containing 0.5% by weight of cobalt chloride is applied to the coated surface.
It was coated to a thickness of 3 mm, and the coated surface was stuck to an iron plate and left at room temperature.

Example 3 Polyethylene 100 parts Ethylene-vinyl acetate copolymer 20 parts Ethylene-propylene-dicyclopentadiene terpolymer 20 parts Cuprous chloride 2 parts The above blended composition was extruded to produce Q, Q 5 Jlm.
A polyethylene film is obtained by molding it into a film with a thickness of .

Natural rubber 10 parts Methyl acrylate 15 parts Tetramethylbutyl hydroperoxide 5 parts Piccoper 1.00 (Terpene resin manufactured by Picco)
10 parts Toluene 260 parts The above-mentioned composite was applied to a concrete surface so that the thickness after drying was 0.03 mm, and a polyethylene film marked ``-'' was attached to this surface and left at room temperature.

Example 4 In the polyethylene film molding composition of Example 2, 2 parts of dimethylaniline was added in place of 1 part of cobalt chloride.
By extruding the composition (7 parts), approximately Q, Q 5
A polyethylene film with a thickness of ym is obtained.

This film was attached to an iron plate in the same manner as in Example 2 and left at room temperature.

Regarding the adhesiveness of the polyethylene films pasted in Examples 1 to 4 above, ]80 peeling adhesive strength (sample width 25
mm, tensile speed 300 mm/min).

In addition, the mechanical strength was measured at a tensile rate of 300 m/min, a sample size of 10 width x 100 questions, and a coating weight of 50 m. These results are shown in the table below.

Patent applicant: Nitto Electric Industry Co., Ltd. -239-

Claims (2)

[Claims] (1) A poly(primary)/fin-based film which contains a polyolefin as a main component, a component that co-crosslinks with the polyolefin, and +(3) a metal salt or tertiary amine that can undergo a redox reaction with an organic peroxide. or sheet, C)
A polyolefin film characterized in that it is applied to an adherend surface via a composition layer containing an organic peroxide and a component having a polar group that can be co-crosslinked with the polyolefin or component a, and is crosslinked and bonded at room temperature. Or a method for improving sheet adhesion. (2) The polyolefin according to claim 1, wherein the polyolefin film or sheet contains 5 to 50 parts by weight of component a and 0.1 to 10 parts by weight of component l) per 100 parts by weight of the polyolefin. Method for improving adhesion of film or sheet.