JPH0812956A - Adhesive composition for surface-protective film - Google Patents

Abstract

PURPOSE:To provide an adhesive composition which can give a surface- protective film having good adhesion to the coated surface of a finished automobile and is capable of being peeled from it without leaving any mark of sticking by using a hydrogenated styrene/diene hydrocarbon random copolymer. CONSTITUTION:40wt.% or above a product of hydrogenation (A) of a random copolymer comprising 1-50wt.% styrene and 99-50wt.% diene hydrocarbon is mixed with 60wt.% or below tackifying resin (B) or softener (C) to obtain an adhesive for a surface-protective film. It is desirable that component (A) is one having a melt flow rate of 2-10g/min as measured at 230 deg.C under a load of 2.16kg. Examples of the diene hydrocarbons of component (A) include isoprene and butadiene. Examples of component (B) include petroleum aliphatic resins and rosin resins, and it is desirable from the viewpoint of their weathering resistance that these resins are hydrogenated. Examples of component (C) used include oils, paraffins and stearic acid. A surface-protective film having a layer of this adhesive has good adhesion to a coating film, a stainless steel sheet, glass, etc., and can be peeled off from the substrate without leaving any mark of sticking.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-sensitive adhesive composition used for a surface protective film which protects a metal surface, a glass surface, a painted surface and the like.

[0002]

2. Description of the Related Art As a conventional method for protecting the top coating surface of the vehicle body of a painted vehicle, there is a method of applying paraffin wax thinly. However, this method has a problem that the protective function is not sufficient and it takes time to remove the paraffin wax.

Further, Japanese Patent Publication No. 5-74627 discloses a method of attaching a plastic film having an adhesive layer to an adherend. According to this method, the above problems are solved, but in this case, the pressure-sensitive adhesive layer is mainly composed of a hydrogenated product of a block copolymer of styrene and a diene hydrocarbon, The adhesion and re-peelability are poor, and the problems such as soiling the adherend and leaving a sticking mark arise.

[0004]

The present invention has good adhesion to an adherend, does not leave stains or sticking marks on the adherend when peeled from the adherend, and is excellent in removability. An object of the present invention is to provide a pressure-sensitive adhesive for a surface protection film, which imparts the above properties to the surface protection film.

[0005]

The present invention relates to styrene 1 to
A pressure-sensitive adhesive composition for a surface protective film, which comprises 40% by weight or more of a hydrogenated product of a random copolymer composed of 50% by weight and 99 to 50% by weight of a diene hydrocarbon, and 60% by weight or less of a tackifying resin or a softening agent. It is a thing. Hereinafter, the present invention will be described in detail.

The hydrogenated product of the random copolymer of styrene and diene hydrocarbon used in the present invention has a styrene content of 1 to 50% by weight and a melt flow rate (ASTM D
1238, hereinafter referred to as "MFR") at 230 ° C, 2.1
It is preferably 6 kg and 2 to 10 g / 10 minutes. When the styrene content is less than 1% by weight, the thermoplasticity of the resin is deteriorated,
When it exceeds 50% by weight, the adhesion to the adherend is deteriorated, the elastic modulus is increased, and the compatibility with the tackifying resin or the softening agent is deteriorated, which is not preferable as a component of the pressure-sensitive adhesive for the surface protection film.

Examples of the diene hydrocarbon used as the copolymerizable monomer include isoprene and butadiene.

Examples of the tackifying resin used include petroleum-based aliphatic resins, alicyclic-based resins, rosin-based resins and terpene-based resins, and hydrogenated resins are particularly preferable from the viewpoint of weather resistance.

Examples of the softening agent used include oil, paraffin wax, low molecular weight polybutene, low molecular weight polyisoprene, stearic acid and the like.

In the adhesive composition, 40% by weight of hydrogenated product of a random copolymer of styrene and a diene hydrocarbon is used.
When less than or less than 60% by weight of the tackifying resin or softening agent, the adhesion to the adherend is deteriorated, and when the surface protective film is peeled from the adherend, the adherend is soiled, It is not practical because it leaves a sticking mark.

The pressure-sensitive adhesive composition for a surface protective film of the present invention, if necessary, within a range not impairing the purpose of the present invention,
Fillers and lubricants such as talc, stearic acid amide, and calcium stearate; pigments and dyes such as titanium dioxide; reinforcing agents such as inorganic hollow particles such as glass balloons and silica balloons; polymeric microspheres, antioxidants, UV absorption Agents, UV stabilizers and the like can be added as appropriate.

The substrate used for the surface protective film using the pressure-sensitive adhesive composition of the present invention includes polyethylene film, polypropylene film, polyester film,
Known plastic films such as nylon and polyvinyl chloride, films in which fillers and pigments such as talc, calcium carbonate and titanium dioxide are kneaded, paper, cloth and the like, and those printed on them be able to.

[0013]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. Example 1 90% by weight of a hydrogenated product of a random copolymer composed of 10% by weight of styrene and 90% by weight of butadiene (Dyalon 1320P manufactured by Japan Synthetic Rubber Co., Ltd.) and a hydrogenated terpene resin (Clearlon M manufactured by Yasuhara Chemical Co., Ltd.) -10
5) 100 parts by weight of a blend consisting of 10% by weight, 0.1 part of a benzotriazole-based ultraviolet absorber (Tinuvin P manufactured by Ciba-Geigy Co., Ltd.) and a hindered phenol-based antioxidant (Irganox 56 manufactured by Ciba-Geigy Co., Ltd.)
5) A pressure-sensitive adhesive composition consisting of 0.1 part was heat-melted to obtain polypropylene (Idemitsu Petrochemical Co., Ltd. Idemitsu Polypro F-7).
00N) 100 parts, 0.1 part of benzotriazole-based ultraviolet absorber (Tinuvin P manufactured by Ciba-Geigy Co., Ltd.) and 0.1 part of hindered phenol-based antioxidant (Irganox 1010 manufactured by Ciba-Geigy Co., Ltd.) It was extrusion coated to a thickness of 20 μm on a base film having a thickness of 60 μm.

Example 2 60% by weight of a hydrogenated product of a random copolymer composed of 10% by weight of styrene and 90% by weight of butadiene (Dinalon 1320P manufactured by Nippon Synthetic Rubber Co., Ltd.) and a hydrogenated petroleum resin (Idemitsu Petrochemical ( 100 parts of a blend consisting of 40% by weight of IAMAVE P-100 manufactured by Co., Ltd., 0.05 part of a benzotriazole-based UV absorber (Tinupine P manufactured by Nippon Ciba-Geigy Co., Ltd.) and a hindered phenolic antioxidant (Nippon Ciba-Geigy). (Irganox 565 manufactured by Co., Ltd.)
Example 1 was prepared by heat-melting an adhesive composition consisting of 0.1 part.
20 μm thick on the same base film as used in
Was extrusion coated.

Example 3 80% by weight of a hydrogenated product of a random copolymer composed of 30% by weight of styrene and 70% by weight of butadiene (Dyalon 1910P manufactured by Nippon Synthetic Rubber Co., Ltd.), a hydrogenated petroleum resin (TONEX Co., Ltd.) Escoletz 5300 manufactured by Kuraray Co., Ltd. and liquid polyisoprene 10% by weight (LIR- manufactured by Kuraray Co., Ltd.)
30) 100 parts by weight of a blend consisting of 10% by weight, 0.1 part of a benzotriazole-based UV absorber (Tinuvin P manufactured by Nippon Ciba-Geigy Co., Ltd.) and a hindered phenol-based antioxidant (Irganox manufactured by Ciba-Geigy Co., Ltd.) 565) 0.1 part of the pressure-sensitive adhesive composition was heat-melted and extrusion-coated on the same base film as used in Example 1 to a thickness of 20 μm.

Comparative Example 1 20% by weight of a hydrogenated product of a random copolymer composed of 10% by weight of styrene and 90% by weight of butadiene (Dinalon 1320P manufactured by Nippon Synthetic Rubber Co., Ltd.) and a hydrogenated terpene resin (Yasuhara Chemical Co., Ltd.) Made Clearon M-10
5) 100 parts of a blend having a composition of 80% by weight, 0.05 part of a benzotriazole-based ultraviolet absorber (Tinupin P manufactured by Nippon Ciba-Geigy Co., Ltd.) and a hindered phenol-based antioxidant (Irga manufactured by Ciba-Geigy Co., Ltd.) Knox 565) 0.05 parts by weight of a pressure-sensitive adhesive composition was heat-melted, and the same base film as that used in Example 1 was prepared.
It was extrusion coated to a thickness of 20 μm.

Comparative Example 2 90% by weight of a hydrogenated product of a block copolymer consisting of 13% by weight of styrene and 87% by weight of butadiene (Kreton G1657 manufactured by Shell Japan Co.) and a hydrogenated petroleum resin (Idemitsu Petrochemical Imarve P -100) A pressure-sensitive adhesive composition consisting of 10% by weight of the blend was heat-melted to give Example 1
20 μm thick on the same base film as used in
Was extrusion coated.

The surface protective films obtained in Examples 1 to 3 and Comparative Examples 1 and 2 were attached to a coated surface, a stainless plate and a glass plate, and tested for adhesion to the adherend and weather resistance. The weather resistance was tested by a weatherometer for removability after 60 hours of carbon arc irradiation, the degree of dirt on the adherend after peeling, and the presence or absence of a sticking mark.

Test Results The test results are shown in Table 1.

[0020]

[Table 1]

As is clear from the results of Examples 1 to 3 in Table 1, the surface protective film using the pressure-sensitive adhesive composition of the present invention has good adhesion to an adherend and weather resistance, and carbon. After the arc irradiation, it had removability from the adherend, did not stain the adherend, and did not leave a sticking mark.

On the other hand, when the hydrogenated product of the random copolymer composed of styrene and diene hydrocarbon in the adhesive composition is less than 40% by weight as in Comparative Example 1, the adhesion to the adherend is poor. Further, it is not suitable as a pressure-sensitive adhesive for a surface protection film because it stains the adherend and leaves a sticking mark when peeling after carbon arc irradiation.

When a hydrogenated product of a block copolymer composed of styrene and a diene hydrocarbon is used as the elastomer component in the pressure-sensitive adhesive composition as in Comparative Example 2,
It is not suitable as a pressure-sensitive adhesive for a surface protective film because it has poor adhesion to an adherend and removability after carbon arc irradiation, stains the adherend during peeling and leaves a sticking mark.

[0024]

EFFECTS OF THE INVENTION The pressure-sensitive adhesive composition of the present invention improves adhesion to an adherend by using a hydrogenated product of a random copolymer of styrene and a diene-based hydrocarbon as an elastomer component, thereby improving adhesion to the adherend. When it is peeled off from the adherend, it does not leave stains or sticking marks on the adherend and has excellent removability.
It can be applied to the surface protection film.

That is, since the surface protective film using the pressure-sensitive adhesive composition of the present invention has good adhesion to a coating film, a stainless plate, glass, etc. and removability after carbon arc irradiation, the surface protective film can be applied. Also, the peeling process is simple, and the surface protection film can be repeatedly used.
In addition, it does not leave stains or marks on the adherend after peeling and has excellent properties as a surface protective film.

Further, since the pressure-sensitive adhesive composition of the present invention is thermoplastic, the method for coating the substrate may be the melt extrusion method using a T die or the extrusion coating method in addition to the spread coating method. You can Furthermore, if a thermoplastic material is selected for the composition of the base material, it is also possible to form the surface protective film from the raw material resin in one step by the hot melt coextrusion method. Therefore, it is possible to simultaneously perform the base material film forming step and the adhesive coating step.

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Claims (1)

[Claims] 1. A composition comprising 40% by weight or more of a hydrogenated product of a random copolymer composed of 1 to 50% by weight of styrene and 99 to 50% by weight of a diene hydrocarbon and 60% by weight or less of a tackifying resin or a softening agent. Adhesive composition for a surface protective film, which is