JPH08143829A - Surface-protecting film for coated film - Google Patents

Abstract

PURPOSE: To obtain the subject film having excellent weatherability and peeling property after use and useful for protection of coated film in transportation or storing of a completed car by coating a tacky adhesive having a specific principal component on a supporting material of olefin-based film having a specific composition. CONSTITUTION: (A) (i) 100 pts.wt. of resin composed of 5-40wt.% ethylene and residual parts of propylene is added with (ii) 0.1-10 pts.wt. of weatherability improver to obtain an olefin-based film having a maximum transmittance to ultraviolet rays of 190-370nm of <=5%, which is used as a supporting material and (B) a tacky adhesive containing at least one kind of polyisobutylene, butyl rubber and polybutene is coated on the supporting material to obtain the objective surface-protecting film. Preferably, the supporting material made of the component A exhibits >=N8 in a Munsell color system and the component (ii) is a hindered amine-based light stabilizer. The adhesive of the component B is preferably composed of 1-20 pts. of a tacky adhesive and 0.1-10 pts. of weatherability improver based on 100 pts. of the rubber component having number-averaged molecular weight of 15-60×10<4> .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface protective film for a coating film, which is temporarily used for protecting the coating film during transportation and storage of a completed automobile.

[0002]

2. Description of the Related Art Recently, when a completed automobile is transported or stored, the product value is deteriorated due to the deterioration of the appearance such as damage to the coating film due to stones, sand dust, dust, iron powder, gas, etc., gloss change, discoloration, etc. Is a problem. In particular, an oil-based or water-based wax-based coating film protective agent has been used in the past because of a high probability of occurrence in an export vehicle that has a long transportation and storage time. However, the wax-based coating film protective agent has insufficient coating film protective performance against iron powder, bird droppings, acid rain, and the like, and further has a bad effect due to penetration of the wax itself into the coating film. If left outdoors for a long period of 3 months or more, peelability becomes difficult, and pollution problems due to the waste liquid at the time of removing the wax and treatment problems of the waste liquid occur. Therefore, as disclosed in Japanese Patent Laid-Open Nos. 2-300281 and 3-221169, a method has been proposed in which an adhesive film is attached to the surface of an automobile body to protect the coating film.

[0003]

However, an adhesive film having a transparent olefin film as a support, which is used for a coated rigid plate or the like, has insufficient weather resistance and cannot withstand long-term outdoor use. Also, when such an adhesive film is attached to the surface of a car body and exposed to the outdoors for a long time, the film deteriorates, and when the film is peeled off from the car body surface, the adhesive is used as a support. There is a risk that the adhesive may transfer to the surface of the coating film without being peeled off together with the film, and the coating film may be soiled. Further, when an acrylic pressure-sensitive adhesive is used, the adhesive strength changes greatly over time, and when it is used outdoors for a long time, the adhesive strength increases and peeling becomes difficult. On the other hand, a polyisobutylene-based pressure-sensitive adhesive has excellent adhesiveness with little change over time and excellent releasability, but since the weatherability of the adhesiveness is insufficient, cohesive force decreases when used outdoors for a long time, and adhesive residue tends to occur. There was a problem.

Further, the coating films of recent automobiles have a low Tg and tend to be flexible, and they are deformed by temperature and application time even at a very slight pressure, resulting in a change in surface roughness and a change in gloss, and stress. Easy air bubbles and film sticking traces due to deformation at the edge of the parting portion are likely to occur. Further, the resins and additives differ depending on the type of coating film, and the polyisobutylene-based pressure-sensitive adhesive is easily affected by changes in the polarity of the surface and bleeding of additives, and the adhesive strength fluctuates greatly, and improvement is desired. The present invention has been made in view of such circumstances, and an object thereof is to provide a surface protective film for a coating film, which solves the above problems.

[0005]

That is, the present invention is to add 0.1 to 10 parts by weight of a weather resistance improver to 100 parts by weight of a resin content consisting of 5 to 40% by weight of ethylene and the balance of propylene, and add ultraviolet rays of 190 to 370 nm. An olefin film having a maximum permeation amount of 5% or less was used as a support, and any one of polyisobutylene, butyl rubber and polybutene was used as the support.
The present invention relates to a surface protection film for a coating film obtained by applying an adhesive containing at least one species as a main component.

In the present invention, the olefin film used as the support is present in the state of a homopolymer mixture of propylene and ethylene, a copolymer or a mixture of a homopolymer and a copolymer, and has an ethylene content of 5 to 5. 40% by weight. 5% by weight of ethylene
If it is less than 40% by weight, the cold resistance is lowered, and if it exceeds 40% by weight, the film becomes too soft, which is not preferable. Further, for modification, an α-olefin such as butene, or a monomer such as vinyl acetate or methyl methacrylate may be copolymerized. Further, an antioxidant, an ultraviolet absorber, a lubricant, a plasticizer and the like may be added for the purpose of improving the weather resistance, heat resistance, processability and workability of the support.

The color of the support is preferably white with a Munsell color system of N8 or more. A colored film made of carbon black or the like has excellent concealing properties and light-shielding properties, and a small amount of addition can reduce the amount of ultraviolet rays transmitted to 10% or less, but the heat increase due to absorption is large, and in the summer it is exposed to direct sunlight at 80 ° C.
Because of the above-mentioned high temperature, problems such as thermal deformation easily occur in a coating film having a low Tg. On the other hand, when Munsell color system is N8 or more white, the temperature rise is small at 60 to 70 ° C., which is preferable. However, when the color is white, the weather resistance of the support itself is insufficient because the light-shielding property of the pigment is small, and it is necessary to add a weather resistance improver. As the weather resistance improver, amine-based,
Quinoline-based, hydroquinone-based, phenol-based, antioxidants such as phosphite-based, antioxidants, or salicylic acid derivatives, benzophenone-based, benzotriazole-based, UV absorbers such as hindered amine-based, light stabilizers, and the like, In particular, hindered amine-based compounds are preferable because they are excellent in compatibility and weather resistance improving effects. The amount of the weather resistance improver added is 0.1 to 10 parts by weight. If it is less than 0.1 part by weight, no effect is obtained, and if it exceeds 10 parts by weight, there is an adverse effect due to migration of the additive to the pressure-sensitive adhesive. Examples of the pigment include white pigments such as titanium oxide, calcium carbonate, barium sulfate and zinc oxide. Coloring of olefin film is
It is usually carried out by adding a pigment or printing on the back surface of the support. The degree of coloring is 5% or less when the maximum amount of transmitted ultraviolet rays is 190 to 370 nm in order to improve the weather resistance of the film.
It is preferably 1% or less.

Polyisobutylene used as a main component of the pressure-sensitive adhesive is a polymer of isobutylene, and butyl rubber has a copolymer of isobutylene and isoprene as a main component and has a crosslinkable functional group such as a carboxylic acid group and a hydroxyl group. Polymerized or chlorinated monomers. Polybutene is a copolymer of isobutylene and structural isomers such as 1-butene and n-butene. One or a mixture of these is used. The number average molecular weight (Mn) of the main component is 15
It should be ~ 600,000. If it is less than 150,000, the cohesive strength and weather resistance of the pressure-sensitive adhesive are insufficient, and if it exceeds 600,000, the adhesive strength is reduced in the low temperature region and the film is liable to be deformed at the edges such as air bubbles or parting portions where stress is likely Sticking marks are likely to occur. The method of measuring the molecular weight includes high performance liquid chromatography, viscosity method, ultracentrifugation method, light scattering method, membrane osmotic pressure method, boiling point elevation method, etc., but high performance liquid chromatography method is simple and as a general method. It is widely used and is the preferred measurement method.

Examples of the releasing agent include vegetable oils, aliphatic soaps, silicones, fluororesins, waxes and long chain alkyl group-containing substances such as alkyl carbamates. In particular, silicone is preferred because it has no film sticking marks and is highly effective in suppressing increase in adhesive strength over time. The silicone resin has various molecular weights having a siloxane bond represented by (Si-O-Si) as a skeleton and has been modified, and includes straight silicone oil such as dimethyl silicone and methylphenyl silicone oil, and polyoxyalkylene. And a modified silicone oil such as amino-modified silicone, or an emulsion thereof. The amount of the release agent added is 0.5 to 10 parts by weight with respect to the rubber as the main component. If it is less than 0.5 parts by weight, the effect of preventing the film from sticking or suppressing the increase in the adhesive force cannot be obtained, and if it exceeds 10 parts by weight, the adhesive force is significantly reduced or transferred by the release agent, which is not preferable.

As the tackifier, natural resins such as rosin, rosin derivative, terpene resin, terpene phenol resin, dammar, copearl and shellac, and petroleum resins such as aliphatic, aromatic and alicyclic resins are used. Examples thereof include phenol resins such as resins, alkylphenol resins and modified phenol resins, and xylene resins. Particularly, a terpene phenol resin-based one is preferable as a tackifier for this application because it has a good compatibility with polyisobutylene and has an appropriate polarity. The addition amount of the tackifier is required to be 1 to 20 parts by weight. If it is less than 1 part by weight, the effect of improving the adhesive strength cannot be obtained, and if it exceeds 20 parts by weight, the transfer of the tackifier to the coating film becomes remarkable. Or adhesive residue is generated due to a decrease in the cohesive strength of the adhesive.

Further, in order to improve the weather resistance of the pressure-sensitive adhesive, it is preferable to add a weather resistance improver. Here, as the weather resistance improver, amine-based, quinoline-based, hydroquinone-based, phenol-based, antioxidants such as phosphite, antioxidants, salicylic acid derivatives, benzophenone-based, benzotriazole-based, hindered amine-based, etc. Examples thereof include an ultraviolet absorber and a light stabilizer, and a benzotriazole-based ultraviolet absorber is particularly preferable because it is excellent in the effect of improving compatibility and weather resistance. The amount of weather resistance improver added is 0.1 to 1
It is set to 0 parts by weight. Less than 0.1 parts by weight has no effect,
If it exceeds 10 parts by weight, there is an adverse effect due to the transfer of the additive to the pressure-sensitive adhesive. It is needless to say that the pressure-sensitive adhesive used in the present invention may contain a commonly used compounding agent such as a softening agent and a coloring agent in addition to the above components.

[0012]

The protective pressure-sensitive adhesive film according to the present invention uses, as a support, a colored polyolefin film having an ultraviolet ray transmission amount of 10% or less in the wavelength range of 190 to 370 nm. The matrix resin that constitutes the support contains propylene as the main component and ethylene component as the main component.
The propylene component is structurally not resistant to sunlight, and the ethylene component is contained to supplement the light resistance. However, the ethylene component has insufficient heat resistance, and the propylene component causes heat resistance to withstand use. Due to these, high weather resistance can be obtained. When a white support having a Munsell color system of N8 or more is used, light rays are reflected by the support and the temperature rise is suppressed. As a result, stress generated in the coating film in contact with the support or the pressure-sensitive adhesive can be suppressed to a low level due to stress relaxation at a high temperature. The stress on this paint film is
An unfavorable phenomenon occurs such as a sticking mark on the coating film.

However, when a white support having a Munsell color system of N8 or more is used, the light rays are reflected by the support, the temperature rise is suppressed, the stress on the coating film is reduced, and no sticking marks are generated. Since a white pigment generally has a small light-shielding property, harmful ultraviolet rays penetrate into the inside of the support, or in some cases reach the pressure-sensitive adhesive layer to decompose the composition. In particular, a colorant added to make the support white may accelerate the photodegradation of the support, and special care must be taken in its use. For example, in the case of titanium dioxide, which is a general white pigment, the water present on its surface causes Ti (4+).
It is said that active species such as OH. And H ₂ O ₂ are generated through generation of OH (-) and generation of electrons and holes due to light absorption, and promotes decomposition. However, by including a hindered amine light stabilizer in the support, the adverse effect can be removed and the weather resistance can be improved. The hindered amine light stabilizer effectively acts on these radicals and peracids to improve the stability. Since it has excellent compatibility with resins among various stabilizers, it can be suitably used without migrating from a base material to a pressure-sensitive adhesive or a coating film of an adherend.

Since most of the ultraviolet rays are absorbed by the support layer, they reach the pressure-sensitive adhesive layer in a small amount, but they are deteriorated by long-term exposure. When the pressure-sensitive adhesive deteriorates, adhesive residue remains on the adherend, causing adhesive residue. In this case, by adding a benzotriazole-based ultraviolet absorber to the pressure-sensitive adhesive, the weather resistance is further improved and the outdoor use for a long time can be endured.

Further, since the pressure-sensitive adhesive of the present invention uses a pressure-sensitive adhesive containing at least one of polyisobutylene, butyl rubber, and polybutene as a main component, the pressure-sensitive adhesive becomes large with time like an acrylic pressure-sensitive adhesive and peels off. It does not become difficult, and the defect in weather resistance can be improved by the absorption of ultraviolet rays by the colored support and the ultraviolet absorber added to the adhesive. By the above, the adhesive film for protecting automobile coating film of the present invention is stuck on the trunk, roof or bonnet of automobiles and exposed to the outdoors for a long time to prevent the coating film from being polluted or scratched, and after use. When removing the adhesive film, the removal workability due to deterioration of the film is not deteriorated, and a good protective effect without adhesive residue or gloss change on the coating film can be realized.

[0016]

EXAMPLES Examples of the present invention will now be described, but the present invention is not limited thereto. In the following description, all parts are parts by weight.

(Example 1) 100 parts of ethylene-propylene copolymer resin (manufactured by Sumitomo Chemical Co., Ltd.) in which 8% by weight of an ethylene component was randomly copolymerized as a support, and titanium oxide (Ishihara Sangyo Co., Ltd.) was used as a white colorant. Company made) 10
Part, hindered amine light stabilizer (Tinuvin 622L
D, trade name of Geigy Co., Ltd.) was added and kneaded, and this was extruded by the T-die method to produce a film having a thickness of 40 μm. This film has a wavelength of 190-37
The light transmission amount at 0 nm was 1% or less, and it was N9 white in the Munsell color system. Using this film as a support, polyisobutylene (MML-80, trade name of Tonex Co., Ltd., number average molecular weight Mn = 180,000) on the surface 10
To 0 parts, an adhesive prepared by adding 3 parts of an ultraviolet absorber (Tinuvin 327, trade name of Ciba-Geigy Co., Ltd.) was applied to a solid content of 10 μm to prepare an adhesive film for automobile coating film protection. did. This was laminated and tested on a black acrylic paint coating plate for automobiles. The formulation and test results are shown in Table 1.

Example 2 As a support, 92 parts of polypropylene resin (Sumitomo Chemical Co., Ltd.), 8 parts of polyethylene resin (Sumitomo Chemical Co., Ltd.) and 10 parts of titanium oxide (Ishihara Sangyo Co., Ltd.) , Hindered amine light stabilizer (Tinuvin 622LD, Geigy product name)
A film having a thickness of 40 μm was produced by adding 0.5 part and kneading, and extruding this by a T-die method. This film has a light transmission of 1 at a wavelength of 190-370 nm.
% Or less, and was N9 white in Munsell color system.
Using this film as a support, polyisobutylene (MML-120, trade name of Tonex Co., Ltd.,
Mn = 300,000 and Opanol B-15, mixed with BASF Japan Ltd. trade name, Mn = 40,000 at a weight ratio of 70/30) to 100 parts of an ultraviolet absorber (Tinuvin 327,
A pressure-sensitive adhesive obtained by adding 3 parts of Ciba-Geigy Co., Ltd.) was applied so as to have a solid content of 10 μm to prepare a pressure-sensitive adhesive film for protecting automobile coating film. This was laminated and tested on a black acrylic paint coating plate for automobiles. The formulation and test results are shown in Table 1.

Example 3 As a support, 60 parts of polypropylene resin (Sumitomo Chemical Co., Ltd.), 40 parts of polyethylene resin (Sumitomo Chemical Co., Ltd.), 10 parts of titanium oxide (Ishihara Sangyo Co., Ltd.), hindered amine Light stabilizer (Tinuvin 622LD, trade name of Geigy Co.) 0.
A film having a thickness of 40 μm was produced by adding 5 parts and kneading, and extruding this by a T-die method. This film had a light transmittance of 1% or less at a wavelength of 190 to 370 nm, and was N9 white in the Munsell color system. Using this film as a support, polyisobutylene (MML-8
0, trade name of Tonex Corporation, Mn = 180,000) 10
To 0 parts, an adhesive prepared by adding 3 parts of an ultraviolet absorber (Tinuvin 327, trade name of Ciba-Geigy Co., Ltd.) was applied to a solid content of 10 μm to prepare an adhesive film for automobile coating film protection. did. This was laminated and tested on a black acrylic paint coating plate for automobiles. The formulation and test results are shown in Table 1.

(Example 4) 10 parts of titanium oxide (manufactured by Ishihara Sangyo Co., Ltd.) per 100 parts of ethylene propylene copolymer resin (manufactured by Sumitomo Chemical Co., Ltd.) in which 8% by weight of an ethylene component was randomly copolymerized as a support. Then, 0.5 part of a hindered amine light stabilizer (Tinuvin 622LD, trade name of Geigy Co.) was added and kneaded, and this was extruded by the T-die method to prepare a film having a thickness of 40 μm. This film had a light transmittance of 1% or less at a wavelength of 190 to 370 nm, and was N9 white in the Munsell color system. Using this film as a support, 100 parts of polyisobutylene (Opanol B150, BASF Japan Ltd., trade name, Mn = 430,000) and 3 parts of an ultraviolet absorber (Tinuvin 327, Ciba Geigy trade name) are added. Was applied so as to have a solid content of 10 μm to prepare an adhesive film for protecting automobile coating film. This was laminated and tested on a black acrylic paint coating plate for automobiles. The formulation and test results are shown in Table 1.

Comparative Example 1 Only polypropylene resin (Sumitomo Chemical Co., Ltd.) was used as a support and T
A film having a thickness of 40 μm was produced by extrusion molding using a die method. This film has a wavelength of 190-370
The amount of light transmitted in nm was 50% or more. An adhesive film for protecting automobile coating film was produced in the same manner as in Example 1 except that a polypropylene resin film was produced. This was laminated and tested on a black acrylic paint coating plate for automobiles. The formulation and test results are shown in Table 1.

Comparative Example 2 An adhesive film for protecting automobile coating film was prepared in the same manner as in Example 1 except that acrylic rubber (Nisetsu KP-1405, trade name of Nippon Carbide Industry Co., Ltd.) was used as the adhesive. . This was laminated and tested on a black acrylic paint coating plate for automobiles. The formulation and test results are shown in Table 1.

Comparative Example 3 As a support, 50 parts of a polypropylene resin (Sumitomo Chemical Co., Ltd.), 50 parts of a polyethylene resin (Sumitomo Chemical Co., Ltd.), and 10 parts of titanium oxide (Ishihara Sangyo Co., Ltd.), Hindered amine light stabilizer (Tinuvin 622LD, Geigy product name)
0.5 part was added and kneaded, and this was extruded by the T-die method to produce a film having a thickness of 40 μm. Using this film as a support, 3 parts of 2-hydroxy-4-n-octoxybenzophenone as an ultraviolet absorber was added to 100 parts of polyisobutylene (MML-80, trade name of Tonex Corporation, Mn = 180,000). The resulting adhesive was applied so as to have a thickness of 10 μm in terms of solid content to produce an adhesive film for protecting automobile coating film. This was laminated and tested on a black acrylic paint coating plate for automobiles. The formulation and test results are shown in Table 1.

Comparative Example 4 100 parts of polypropylene resin (manufactured by Sumitomo Chemical Co., Ltd.) as a support, 10 parts of titanium oxide (manufactured by Ishihara Sangyo Co., Ltd.), a hindered amine light stabilizer (Tinuvin 622LD, trade name of Geigy Corporation) )
0.5 part was added and kneaded, and this was extruded by the T-die method to produce a film having a thickness of 40 μm. Using this film as a support, polyisobutylene (Opanol B246, BA
SF Japan Co., Ltd., product name, Mn = 760,000) 100 parts of an ultraviolet absorber (Tinuvin 327, Ciba Geigy product name) is added in an amount of 3 parts so that the solid content has a thickness of 10 μm. To prepare an adhesive film for protecting automobile coating film. This was laminated and tested on a black acrylic paint coating plate for automobiles. The formulation and test results are shown in Table 1.

Comparative Example 5 100 parts of a polypropylene resin (manufactured by Sumitomo Chemical Co., Ltd.) in which 8 wt% of an ethylene component was randomly copolymerized as a support was extrusion-molded by a T-die method to prepare a film having a thickness of 40 μm. An adhesive consisting of 100 parts of polyisobutylene (MML-80, trade name of Tonex Corporation, Mn = 180,000) was added to this film.
It was applied so as to have a thickness of 10 μm in terms of solid content, and an adhesive film for protecting automobile coating film was produced. This was laminated and tested on a black acrylic paint coating plate for automobiles. The formulation and test results are shown in Table 1.

[0026]

[Table 1]

(* 1) Ethylene propylene random copolymer resin containing 8% by weight of ethylene component (* 2) Geigy product name: "Tinuvin 622LD" (* 3) BASF Japan Ltd. product name: "Opanol B
246 "(* 4) BASF Japan Ltd. Product name:" Opanol B
150 "(* 5) Tonex Co., Ltd. product name:" MML-120 "(* 6) Tonex Co., Ltd. product name:" MML-80 "(* 7) BASF Japan K.K. product name:" Opanol B "
15 "(* 8) Ciba Geigy product name:" Tinuvin 327 "(* 9) Benzophenone-based UV absorber Initial adhesive strength: Measured at a peeling angle of 90 ° and a peeling speed of 200 mm / min. Weather resistance test: Using a Sunshine Weather Meter manufactured by Suga Test Instruments Co., Ltd., ambient temperature 43 ° C., 50% R
Under the conditions of H, a black panel temperature of 63 ° C., and a rainfall of 12 minutes / 1 hour, the adhesive force after the treatment for 500 hours, the peeled surface of the coated plate when peeled, and the state of the film of the support were evaluated. Heat resistance test: After being left for 24 hours in a thermostat at 80 ° C., the adhesive strength and the state of the peeled surface of the coated plate when peeled off were evaluated. Note 1 Measurement is not possible because the support film is cut and cannot be peeled off. Evaluation: "○" Good with no bubble marks or film sticking marks. "△" There is a bubble mark or film sticking mark that can be understood by a coating expert. "X" Those with obvious air bubble marks and film sticking marks to everyone's eyes.

As shown in the examples and comparative examples, the main component of the resin for the support is propylene and the ethylene component is 5
Contains 40% by weight to 40% by weight, and the amount of transmitted UV light is 1
The weather resistance is improved by using a colored polyolefin film of 10% or less in the range of 90 to 370 nm. The stabilizer contained in the support is effective as added, as is clear from the comparison of the films after the weather resistance test of Example 1 and Comparative Example 5, and the hindered amine light stabilizer is particularly effective in various studies. Met. From the comparison between Example 3 and Comparative Example 3, the benzotriazole-based ultraviolet absorber was effective as the ultraviolet absorber added to the adhesive.

Example 5 To 92 parts of a polypropylene resin (manufactured by Sumitomo Chemical Co., Ltd.) copolymerized with 8% by weight of an ethylene component, 8 parts of titanium oxide (manufactured by Ishihara Sangyo) and a hindered amine type as a weather resistance improver (MU41, manufactured by Sumitomo Chemical Co., Ltd.) 0.1 part was added and pressed by the T-die method to a thickness of 40μ.
A support for the base film of m was prepared. The support has a light transmittance of 1% or less for ultraviolet rays of 190 to 370 nm and a color of 9 in the Munsell color system. On the other hand, polyisobutylene (Opanol B80, BASF, Mn = 180,000) 10
To 0 part, 3 parts of a benzotriazole-based ultraviolet absorber (Tinuvin 327, manufactured by Ciba Geigy) as a weather resistance improver,
A terpene phenolic resin-based tackifier (YS Polystar T115, manufactured by Yasuhara Chemical) and 10 parts of a silicone release agent (KF-96, manufactured by Shin-Etsu Chemical Co., Ltd.) were added to the film as a solid content to give a pressure-sensitive adhesive. Of 10 μm was applied to prepare a surface protective film for the coating film.

Example 6 As a support, 92 parts of a polypropylene resin (Sumitomo Chemical Co., Ltd.), 8 parts of polyethylene resin (Sumitomo Chemical Co., Ltd.), 8 parts of titanium oxide (Ishihara Sangyo Co., Ltd.) and a weather resistance improver were used. Add 0.1 parts of MU41, add T
It was pressed by a die method to produce a base film having a thickness of 40 μm. This substrate film has a light transmittance of 1% or less for ultraviolet rays of 190 to 370 nm and a color of 9 in the Munsell color system.
Polyisobutylene was added to this film as Opanol B10.
0 (BASF, Mn = 250,000) and Opanol B15
(BASF, Mn = 40,000) mixture (7 by weight ratio)
0:30) except that the same adhesive as in Example 5 was used.
Application was performed in the same manner as in Example 5 to produce a surface protective film.

(Comparative Example 6) A surface protective film was prepared in the same manner as in Example 5 except that a base film was prepared using only a polypropylene resin (manufactured by Sumitomo Chemical Co., Ltd.) as a support. (Comparative Example 7) Opanol B15 as polyisobutylene
A surface protective film was produced in the same manner as in Example 6 except that was used.

(Comparative Examples 8, 9 and 10) No ultraviolet absorber was added (Comparative Example 8), no tackifier was added (Comparative Example 9), and no silicone release agent was added (Comparative Example). A surface protective film was produced in the same manner as in Example 5 except for 10).

The surface protective film obtained in each of the above Examples and Comparative Examples was applied to each of two types of automotive paint coating plates (A: acrylic clear coating plate, B: hard polyester solit coating plate). Then, the initial adhesive strength was measured, and the coating film A was tested for weather resistance and heat resistance. For the adhesive force, the load (gf) when the end portion of the film having a width of 25 mm was pulled in the direction of 90 degrees at a speed of 200 mm / min and peeled off was determined. The weather resistance is measured by using a Sunshine Weather Meter manufactured by Suga Test Instruments Co., Ltd., and the adhesive strength after treatment for 500 hours under the conditions of an atmospheric temperature of 43 ° C., a humidity of 50%, a black panel temperature of 63 ° C., and a rainfall of 12 minutes / 1 hour. Was measured, and the appearance of the peeled surface and the entire film was observed. Regarding the heat resistance, the adhesive strength after heating at 80 ° C. for 24 hours was measured, and the appearance of the peeled surface was observed. The results are shown in Table 2.

[0034]

[Table 2] Note 1: Film cutting occurred and peeling was not possible, so measurement was not possible. Note 2: Film cutting occurred and peeling could not be done. Note 3: Deterioration noticeable Note 4: Adhesive residue noticeable Note 5: Film sticking mark (air bubbles, wrinkles) , The parting mark) is generated remarkably.

As is clear from Table 2, the examples have better weather resistance and heat resistance than the comparative examples, are excellent in releasability, and have deterioration of the film, adhesive residue and film sticking marks. Occurrence is small.

[0036]

EFFECTS OF THE INVENTION According to the present invention, an adhesive film for protection which is temporarily used for protecting a coating film during transportation and storage of a finished vehicle has sufficient weather resistance and is excellent in peelability after use. It is possible to provide an adhesive film having good properties that does not stain the coating film. Prevents deterioration of weather resistance of colorants in addition to using a light-shielding film for the support and improving the weather resistance by containing an ethylene component, which is more weather resistant than the propylene component, in the support itself Since a hindered amine-based light stabilizer is added to the composition to further improve weather resistance, workability during peeling is not deteriorated. The additive has excellent compatibility with the resin and is excellent without migration to the pressure-sensitive adhesive or the surface of the support, and has no effect on the coating film. Further, since the pressure-sensitive adhesive contains, as a main component, at least one of polyisobutylene, butyl rubber, and polybutene, which has a small interaction with the coating film, it does not impair the coating film performance. With the above structure, it is possible to provide a pressure-sensitive adhesive film for automotive coating film protection that does not have a trace of air bubbles or adhesive residue on the coating film, and is a coating film that has just been applied as a protective pressure-sensitive adhesive film during transportation and storage of automobiles. It is possible to sufficiently exert the performance of protecting the coating film from contamination and scratches while protecting it from ultraviolet rays.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Osamu Yamamoto 1500 Ogawa, Shimodate City, Ibaraki Hitachi Chemical Co., Ltd. Shimodate Research Laboratory (72) Inventor Kazuya Shiogetsu 19-17 Ikedanaka-cho, Neyagawa-shi, Osaka Japan Within Paint Co., Ltd.

Claims (5)

[Claims] 1. A weather resistance improver is added to 100 parts by weight of a resin component consisting of 5 to 40% by weight of ethylene and the balance of propylene.
In addition to 1 to 10 parts by weight, an olefinic film having a maximum transmittance of ultraviolet rays of 190 to 370 nm of 5% or less is used as a support, and a pressure-sensitive adhesive containing any one or more of polyisobutylene, butyl rubber and polybutene as a main component is used. A surface protective film for a coating film formed by coating the support. 2. The surface protective film for a coating film according to claim 1, wherein the color of the support is N8 or more in the Munsell color system, and the weather resistance improver is a hindered amine light stabilizer. 3. The tackifier is 1 to 20 parts by weight with respect to 100 parts by weight of a rubber component whose main component is any one or more of polyisobutylene, butyl rubber and polybutene having a number average molecular weight of 150,000 to 600,000. Part and weather resistance improver 0.1
The surface protective film for a coating film according to claim 1 or 2, which is an adhesive comprising 10 to 10 parts by weight. 4. The surface protective film for a coating film according to claim 3, wherein the tackifier is hydrogenated terpene phenol, and the weather resistance improver is a benzotriazole-based ultraviolet absorber. 5. The adhesive is used for 100 parts by weight of the rubber component,
The surface protective film for a coating film according to claim 1, which is an adhesive containing 0.5 to 10 parts by weight of a release agent.