JP2001348544A - Covering sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a covering sheet satisfying such protective performance as to cause no damage of its coating film even if medium-sized matter such as pebbles, hail or working tools larger than dust, rain droplets or the like hit thereagainst while being prevented from malappearance such as coating film level difference and/or debonding of the curved part and occurrence of peeling under transportation activity. SOLUTION: This covering sheet is obtained by providing one side of a substrate of resin foam with an adhesive layer with the outer surface roughened. This covering sheet thus obtained has the following advantages: even in the case of increased thickness of the substrate, the sheet is deformed smoothly in compliance with even a curved area through exhibiting favorable flexibility and moderate stretchability and excellent in protective function for matter hit thereagainst by the aid of cushionability owing to its increased thickness and foam structure, and air bubbles are hard to be entrained in making an adhesive covering and wrinkles seldom occur as well.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is excellent in the ability to prevent damage from collisions and the ability to follow a curved surface, hardly deteriorates or discolors the coating film, protects the coating of automobile bodies and parts, and applies the surface of decorative plywood and painted steel plates. The present invention relates to a cover sheet suitable for protection and the like.

[0002]

2. Description of the Related Art Conventionally, when a painted automobile or its parts are loaded on a truck or ship and transported to a remote place such as overseas, suspended matters such as dust and dirt, rain and stones, or collisions occur. As a means for preventing damage to the coating film due to the object, gloss blurring, discoloration, and the like, a coating material of a wax-based coating material having a thickness of 5 to 40 μm has been known. However, it is difficult to form a uniform thickness of the wax coating, and it is difficult to obtain uniform protection, it is easy to get dirty, it is susceptible to acid rain, and wax and the like penetrate the coating coating and cause discoloration and the like. In addition, there has been a problem that a great deal of labor is required for applying and removing the wax coating film, and it is easy to cause environmental problems such as use of a solvent and treatment of a waste liquid.

On the other hand, various surface protection sheets comprising an adhesive layer provided on a support substrate made of a film are known, and for protecting a coating film, a radiation-cured adhesive layer having a low glass transition point or a polyolefin is known. A device provided with a rubber-based adhesive layer such as isobutylene has been proposed (JP-A-2-199184, JP-A-6-73352). According to such a sheet system, the problems of the wax system can be overcome.

[0004] However, the conventional protective sheet can exert a sufficient protective function against relatively small collision objects such as dust and rain to prevent the occurrence of damage. When the size is increased to hail, work tools, etc., there is a problem that the protection function is insufficient and the coating film is damaged.

[0005]

It is effective to increase the film thickness in order to solve the above-mentioned problem of insufficient protective function. However, in this case, stress and rigidity increase when the film is peeled off after bonding to the coating film. Streaked depressions due to steps are likely to occur in the film, especially at the coating portion at the position corresponding to the sheet edge, and poor adhesion such as floating on the curved surface is likely to occur, resulting in poor appearance and peeling during transportation, etc. And the practicality of the protective sheet is greatly impaired. Therefore, the present invention provides protection that prevents damage to the coating film even for medium-sized collision objects such as pebbles, hailstones, and work tools that are larger than dust and rain while preventing appearance defects and peeling during transportation. The task is to develop a cover sheet that satisfies the functions.

[0006]

The present invention provides a cover sheet characterized in that an adhesive layer whose outer surface is roughened is provided on one side of a support base made of a resin foam.

[0007]

According to the present invention, even when the thickness is increased by using a resin foam-type support base material, it exhibits good flexibility and moderate expansion and contraction allowance, and is suitable for curved surfaces. Following the deformation, the adhesive cover can be formed without lifting, etc., and the coating film after peeling is less likely to have a step, which can prevent peeling and poor appearance during transportation. It shows a protection function that does not damage the coating film even if a large object such as a pebble, hail, or work tool collides. In addition, by using the above-mentioned foamed base material, it is possible to form an adhesive layer having a rough outer surface structure by reflecting the surface unevenness structure, and it is difficult for air bubbles and the like to be mixed in the adhesive cover and wrinkles are hardly generated, so that work efficiency is improved. Adhesion treatment can be performed well, and peelability and volatilization of infiltrating rainwater can be improved, so that it is possible to prevent the formation of an adhesive cover mark on the coating film after peeling.

Therefore, as a result of the above, a good adhesion state can be maintained for a long period of time to prevent the peeling phenomenon at the time of transportation or the like and the damage of the coating film due to a collision object. In the case of an adhesive layer whose surface is made uneven by embossing, transfer of the generated uneven structure to a coating film and generation of adhesive residue after separation (contamination due to residual adhesive layer) can be avoided. A cover sheet can be obtained.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A cover sheet according to the present invention comprises a pressure-sensitive adhesive layer having a roughened outer surface provided on one side of a support base made of a resin foam. The pressure-sensitive adhesive layer can be formed by using one or two or more kinds of appropriate pressure-sensitive adhesives such as rubber-based, acrylic-based, or urethane-based, and the pressure-sensitive adhesive is formed by combining one or more suitable polymers with a base polymer. It may be. In particular, a rubber-based pressure-sensitive adhesive having a base polymer of a rubber-based polymer having no unsaturated bond can be preferably used from the viewpoint of long-term stability of pressure-sensitive adhesive properties.

Examples of the rubber-based polymer include diene-based polymers such as polyisobutylene and butyl rubber, polyisoprene and polybutadiene, and hydrogenated products thereof.
Olefin polymers such as ethylene-propylene rubber, ethylene-α-olefin copolymer, ethylene-propylene-α-olefin copolymer and propylene-α-olefin copolymer, styrene-butadiene-styrene (SBS), styrene- Isoprene styrene (SI
S), A / B / A type styrenic block polymers such as styrene / ethylene / butylene copolymer / styrene (SEBS) and styrene / ethylene / propylene copolymer / styrene (SEPS), styrene / butadiene (SB)
And styrene / isoprene (SI), styrene / ethylene-butylene copolymer (SEB) and styrene / ethylene-
A / B type styrene block polymer such as propylene copolymer (SEP), random copolymer of styrene and diene hydrocarbon such as styrene / butadiene rubber or hydrogenated product thereof, styrene / ethylene / butylene copolymer / ABC type styrene such as olefin crystal (SEBC)
Olefin crystal block polymer, olefin crystal
Ethylene-butylene copolymer / olefin crystal (CEB
C / B / C type olefin crystal block polymers such as C). The rubber-based pressure-sensitive adhesive may be based on one or more rubber-based polymers.

In forming the pressure-sensitive adhesive layer, for example, a softener, an olefin polymer, a silicone polymer or an acrylic polymer, a tackifier, an antioxidant, a hindered amine, etc. And other suitable additives such as fillers and pigments such as calcium oxide, magnesium oxide, silica, zinc oxide, and titanium oxide.

[0012] The blending of a softening agent is generally effective for improving the adhesive strength. As the softener, for example, a low molecular weight polyisobutylene or polybutene, polyisoprene or polybutadiene, hydrogenated polyisoprene or hydrogenated polybutadiene, a reactive group such as a hydroxyl group, a carboxyl group, or an epoxy group is introduced at one or both ends thereof. Derivatives, ethylene-α-olefin copolymers and ethylene-propylene-α-olefin copolymers, olefin-based polymers such as propylene-α-olefin copolymers and ethylene-propylene rubber,
One or two of appropriate ones such as process oil, naphthenic oil, castor oil, linseed oil, soybean oil, phthalate ester plasticizer, phosphate ester plasticizer, and liquid aliphatic petroleum resin
More than one species may be used.

The softening agent which can be preferably used from the viewpoint of preventing the transfer of a substance to an adherend such as a coating film and the like and moderately increasing the adhesive force to the adherend has a number average molecular weight of 1000 to 30.
10,000, especially 2000-150,000, especially 3000-100,000. The blending amount of the softener can be appropriately determined according to the adhesive strength and the like, but is generally 100 parts by weight or less, preferably 60 parts by weight or less, particularly 4 parts by weight, per 100 parts by weight of the base polymer.
A blending amount of 0 parts by weight or less is preferable.

On the other hand, an olefin-based polymer can be blended for the purpose of suppressing an increase in adhesive strength to an adherend. As such an olefin polymer, an appropriate polymer having a higher molecular weight than the above-mentioned polyolefin softener can be used. For example, low density or linear low density, medium density or high density polyethylene, polypropylene, ethylene / α-olefin copolymer, ethylene / propylene / α-olefin copolymer or propylene / α-olefin copolymer may be used. Examples include polymers, ethylene / ethyl (meth) acrylate copolymer, ethylene / methyl (meth) acrylate copolymer, and ethylene / propylene rubber. One or more of such olefin-based polymers can be used, and the amount of the olefin-based polymer can be appropriately determined according to the adhesive strength and the like. Generally, the amount is preferably 50 parts by weight or less, more preferably 30 parts by weight or less, and particularly preferably 20 parts by weight or less per 100 parts by weight of the base polymer.

The compounding of the silicone polymer is usually
It is effective for improving the releasability. As the silicone polymer, one or more kinds of appropriate polymers having various molecular weights having a siloxane bond as a skeleton can be used. Incidentally, examples thereof include dimethyl polysiloxane, methyl phenyl polysiloxane, methyl hydrogen polysiloxane and modified products thereof, for example, epoxy type, alkyl type, amino type, carboxyl type, alcohol type, fluorine type, alkyl aralkyl polyether. System and epoxy
Modified products such as polyethers and polyethers are exemplified. The compounding amount of the silicone-based polymer is 5 parts by weight or less, preferably 3 parts by weight or less, particularly 0.005 to 2 parts by weight, based on 100 parts by weight of the base polymer, from the viewpoints of good adhesion state stability and peeling stability. Parts are preferred.

On the other hand, the blending of the acrylic polymer is intended to develop good adhesion to the adherend by improving the wettability and to suppress the aging of the adhesion at high temperatures. An acrylic polymer having a molecular weight of 1,000 to 500,000 is preferably used. That is, the acrylic polymer having the molecular weight exhibits a liquid state at normal temperature and is oriented on the surface of the adhesive layer due to the compatibility with the base polymer, thereby exhibiting good wettability to the adherend. It is considered that it exhibits adhesive strength, is stable against heat, and exhibits good peelability at the time of peeling.

In the above, if the weight average molecular weight of the acrylic polymer is less than 1,000, the molecular weight is too low and the effect of improving the adhesive strength may be poor, and if it exceeds 500,000, the stability over time and the releasability after long-term bonding are poor. May be. Acrylic polymers that can be preferably used from the viewpoints of improvement in adhesive strength, stability over time and stability of peelability have a weight average molecular weight of 3,000 to 300,000, particularly 5,000 to 100,000, and particularly 10,000 to 50,000. belongs to. The acrylic polymer which can be preferably used from the viewpoint of wettability to an adherend such as a coating film has a glass transition temperature of 25 ° C or lower, particularly 0 ° C or lower, particularly -10 ° C.
These are:

One or more acrylic polymers can be used, and there is no particular limitation on the monomers to be formed. By the way, as an example, the carbon number is 1-18.
(Meth) acrylates having an alkyl group of
Examples thereof include those obtained by subjecting a kind or two or more kinds to an acrylic pressure-sensitive adhesive such as (meth) acrylamide, if necessary, with a known copolymerizable monomer and performing a polymerization treatment by an appropriate method such as solution polymerization. Such acrylic polymers include, for example, Polyflow No. (trade name). 55 and polyflow No. 50E
(Manufactured by Kyoeisha Chemical Co., Ltd.), Disparon LC-951, Disparon LC-955, and Disparon LC-1985
There are also commercially available products such as (Kusumoto Kasei) and Modaflow (Monsanto).

The amount of the acrylic polymer is preferably 0.05 to 40 parts by weight per 100 parts by weight of the base polymer. If the amount is less than 0.05 part by weight, the effect of improving the adhesive strength may be poor due to insufficient compounding. If the amount is more than 40 parts by weight, the adhesive will be oriented in a layer state on the surface of the adhesive layer, and the adhesive force will be greatly reduced. In some cases, problems such as peeling may easily occur. The preferable amount of the acrylic polymer is 30 parts by weight or less, preferably 0.05 to 20 parts by weight, particularly 0.1 to 10 parts by weight per 100 parts by weight of the base polymer from the viewpoint of the formability of a good adhesion state. It is.

Further, the compounding of a tackifier is generally effective in improving the adhesive strength. Examples of the tackifier include petroleum resins such as aliphatic, aromatic, aliphatic / aromatic copolymers and alicyclic resins, coumarone indene resins, terpene resins, terpene phenol resins, One or more known suitable pressure-sensitive adhesives such as (alkyl) phenol-based resins, rosin-based resins, polymerized rosin-based resins, xylene-based resins, and hydrogenated resins thereof can be used. The amount of the tackifier is 80 parts by weight or less, preferably 40 parts by weight, per 100 parts by weight of the base polymer from the viewpoint of improving the adhesive force while avoiding the problem of adhesive residue due to the decrease in cohesive force.
It is preferably at most 20 parts by weight, especially at most 20 parts by weight.

On the other hand, as the supporting base material to which the pressure-sensitive adhesive layer is to be attached, a resin foam is used. As the resin foam, an appropriate one can be used according to the purpose of use of the cover sheet. By the way, examples of the resin foam include a single type, a propylene type polymer such as a block type, a random type and a graft type containing ethylene, an ethylene type polymer such as a low density, a high density and a linear low density, an ethylene type.・ Olefins such as propylene copolymers and ethylene / α-olefin copolymers, or olefin-based polymers also containing monomers other than olefins such as ethylene / styrene copolymers, polystyrene, polyester, polyurethane and polyamide, as described above The styrene-based block copolymer and its hydrogenated product, and the styrene-based random copolymer and its hydrogenated product may be used alone or in combination.

A foam made of an olefin-based polymer can be particularly preferably used in view of the incineration property and the disposability of the cover sheet after peeling. In the resin foam, suitable additives such as antioxidants and ultraviolet absorbers, light stabilizers such as hindered amines, antistatic agents and inorganic fillers exemplified in the above adhesive layer for the purpose of preventing deterioration and the like. Can also be blended. The thickness of the supporting substrate made of resin foam is 0.1
It is generally, but not limited to, ５０50 mm, especially 0.5-30 mm, especially 1-20 mm.

The resin foam is, for example, propane or (n,
i) -butane, (n, i)-volatile organic blowing agents such as hydrocarbons such as pentane and cyclopentane, pentene and hexane, and their halides; inorganic gas blowing agents such as carbon dioxide, air and nitrogen; Dicarbonamide or N, N '
-Foaming treatment using one or more suitable foaming agents such as decomposition-type foaming agents such as dinitrosopentamethylenetetramine and azobisisobutyronitrile, and inorganic foaming agents such as sodium hydrogen carbonate and calcium carbonate. Or a foamed master badge obtained by mixing a commercially available foamable master badge with the above resin, and foaming the foamed resin by an appropriate method.

The resin foam may have an appropriate foam structure such as closed foam, open foam, or a mixture thereof, and preferably has an independent foam structure from the viewpoint of improving impact resistance. . The expansion ratio is arbitrary, but in general, the expansion ratio is preferably 1 to 100 times, more preferably 2 to 50 times, especially 5 to 40 times from the viewpoint of strength and cushioning property.

The support base material may be provided with a laminate layer on one or both sides of a resin foam for the purpose of improving the strength and preventing penetration of rainwater or the like. When the supporting substrate has the above-mentioned laminate layer, the adhesive layer can be provided on the laminate surface or on the surface without the laminate layer. In the present invention, the outer surface of the pressure-sensitive adhesive layer may be roughened by reflecting the uneven structure on the surface of the resin foam as described above. In that case, it is possible to control the roughening state by interposing a laminate layer or not, and it is preferable to provide an adhesive layer without the interposition of a laminate layer when the uneven structure on the surface of the resin foam is moderate. When the uneven structure is too large, it is preferable to suppress the roughening (irregularity) of the outer surface of the adhesive layer by interposing a laminate layer.

The laminate layer can be formed as an appropriate resin coating layer or a film adhesive layer. As the resin, one or more of the appropriate ones exemplified for the above-mentioned foams can be used. A thermoplastic resin such as a middle olefin polymer or a polyamide or polyester can be preferably used. Olefin polymers are particularly preferred from the viewpoint of incineration properties after peeling.

The thickness of the laminate layer can be appropriately determined depending on the strength and the ability to follow a curved surface, and is generally 5 to 50 μm, preferably 7 to 40 μm, particularly preferably 10 to 30 μm. Lamination of the resin to the resin foam, for example, a method of laminating a resin film on a resin foam by extruding a resin film on the resin foam, a heat lamination method of a film or an adhesion method using an adhesive,
It can be performed by an appropriate method such as a method of applying a resin solution.

The cover sheet may be formed by, for example, applying a solution of a pressure-sensitive adhesive layer forming material in a solvent or a hot melt to one surface of the support substrate, and transferring the pressure-sensitive adhesive layer formed on the separator to one surface of the support substrate. Adhesive layer forming method, Extrusion coating of adhesive layer forming material on one side of support substrate, Single layer lamination of adhesive layer on one side of support substrate, Laminating two layers with laminate layer, Resin and foam A method of co-extruding a support base material composed of a mixture of the adhesive master badges and a pressure-sensitive adhesive layer in two or more layers, or a two-layer or multi-layer structure of a pressure-sensitive adhesive layer and a support base material such as a resin foam or a laminate layer It can be performed according to a known method for forming an adhesive sheet, such as a method for laminating.

From the viewpoint of production efficiency and the like, a preferable method for forming the cover sheet is a two-layer extrusion molding method of a foaming agent-containing resin and an adhesive layer, or a method of forming a laminate layer between the resin layer and the adhesive layer or on the side opposite to the adhesive layer. This is a method in which a support base material and an adhesive layer are simultaneously extruded and foamed, such as a three-layer extrusion molding method in which a support layer is provided, or a four-layer extrusion method in which a laminate layer is provided between a resin layer and an adhesive layer and on the side opposite to the adhesive layer. The pressure-sensitive adhesive layer and the laminate layer may be subjected to a foaming treatment by blending a foaming agent if necessary.

The pressure-sensitive adhesive layer provided on one side of the supporting substrate has a roughened outer surface. This allows the adhesive surface of the adhesive layer to adhere to the adherend to have good volatility of infiltrating rainwater due to air permeability and moisture permeability, and that a trace of the protective sheet hardly remains on the adherend such as a paint film after peeling. can do.

From the viewpoint of the balance between the prevention of stagnation due to good volatilization of infiltrating rainwater and the prevention of insufficient adhesion due to the securing of the bonding area, a preferable roughened state on the outer surface of the adhesive layer is as follows.
The surface roughness is 10 μm or more, especially 50 μm or more, especially 100 to 20 based on Ra according to JIS B0601.
It is at least 30 μm, especially at least 100 μm, especially from 500 to 5000 μm, based on 00 μm or / and Rmax.

The outer surface of the adhesive layer can be roughened by an appropriate method. Incidentally, as an example, a solid coating is performed by the above-described coating method or extrusion method, and a roughening treatment such as embossing or a method of reflecting irregularities on the surface of a supporting substrate such as a resin foam on an adhesive surface is performed. And a method in which an adhesive layer whose outer surface is roughened is formed on a separator subjected to embossing or the like, and then transferred.

The adhesive layer forming material is formed into fibers by an appropriate method such as a melt blow method or a curtain spray method, and is deposited. A method in which the outer surface of the layer is roughened, a method in which the pressure-sensitive adhesive layer forming material is partially applied in a dot-like or lattice-like manner to form a pressure-sensitive adhesive layer in which the outer surface is roughened, and the like are also included. Therefore, the pressure-sensitive adhesive layer may be formed in a state of exhibiting air permeability such as the nonwoven fabric-like or dot-like one described above.

The thickness of the pressure-sensitive adhesive layer may be appropriately determined according to the adhesive strength and the like, and is generally 3 to 100 μm, preferably 7 to 7 μm.
0 μm, especially 10 to 50 μm. If necessary, the adhesive layer can be temporarily protected by a separator or the like until it is put to practical use. The surface of the pressure-sensitive adhesive layer may be subjected to a surface treatment for controlling tackiness or adhesion workability, if necessary, such as a corona discharge treatment, an ultraviolet irradiation treatment, a flame treatment, a plasma treatment, and a sputter etching treatment. Can also. By such a surface treatment, the outer surface of the adhesive layer can be roughened.

The above-mentioned surface treatment can be applied to the surface of the supporting substrate on which the adhesive layer is provided, if necessary, for the purpose of improving the adhesion of the adhesive layer. An undercoating treatment such as a primer is effective for improving the adhesion of the adhesive layer. On the surface of the support substrate on which the pressure-sensitive adhesive layer is not provided, for example, a coat made of a suitable release agent such as a silicone-based, long-chain alkyl-based, or fluorine-based material for the purpose of forming a roll that can be easily unwound. Layers can also be provided.

[0036] The cover sheet according to the present invention may be one which shows a property of blocking ultraviolet rays. The ultraviolet-shielding cover sheet is excellent in long-term stability of good peelability without breakage or adhesive residue by preventing deterioration of the support base material and the adhesive layer outdoors and the like. A preferred UV-shielding cover sheet is
UV transmittance at a wavelength of 190 to 370 nm is 5% or less, preferably 3% or less, particularly 1% or less, and more preferably 0.5% or less.

The ultraviolet-shielding cover sheet can be formed by an appropriate method using a supporting base material and / or an adhesive layer. Incidentally, for the supporting base material, for example, a method of dispersing and holding ultraviolet shielding particles can be applied to a part or all of the formed members such as the resin foam and the laminate layer. Such a method of dispersing and retaining ultraviolet blocking particles can also be applied to an adhesive layer. As a specific example, a resin foam or a laminate layer made of the mixture by mixing ultraviolet ray blocking particles and a thermoplastic resin or an adhesive layer forming material, and applying a suitable film forming method such as a T-die method or an inflation method. Alternatively, a method of forming an adhesive layer may be used.

In addition, it is possible to obtain an ultraviolet-shielding supporting substrate by a method of forming a coating film by adhering a coating solution containing ultraviolet-shielding particles to the surface of the supporting substrate, or by using the above-mentioned method in combination. Can be. The coating liquid is, for example, a binder component composed of a suitable resin such as an acrylic, urethane, or polyester resin, and a dispersion liquid in which ultraviolet blocking particles are mixed via a medium composed of a suitable organic solvent such as toluene or water. Can be obtained as

The application of the coating liquid can be performed by an appropriate method such as a dipping method in the liquid, a liquid spraying method, a liquid coating method using a gravure coater or a reverse coater, or the like. The thickness of the coating film may be appropriately determined, but is generally preferably 40 μm or less, more preferably 20 μm or less, particularly preferably 0.5 to 10 μm from the viewpoint of processing efficiency and thinning.

As the above-mentioned ultraviolet ray blocking particles, for example, appropriate particles which reflect or absorb ultraviolet rays such as titanium white, red iron oxide, zinc white, alumina, tin oxide and carbon black can be used. Among them, titanium white, zinc white and the like are preferable from the viewpoint of the effect of blocking ultraviolet rays. The particle size of the ultraviolet ray blocking particles may be determined as appropriate, but is generally 0.005 to 5 μm, especially 0.01 to 1 μm based on the average particle size from the viewpoint of the stability or long-term durability of the dispersed state. , Especially 0.
It is preferably from 02 to 0.5 µm.

On the other hand, the ultraviolet shielding treatment can also be performed by a method in which a vapor deposition film made of a suitable metal such as stainless steel is provided on the supporting substrate. In this case, the thickness of the deposited film or the like is 10,000 ° or less, preferably 10 to 5000 °, and particularly 1
It is preferable to set it to 00 to 1000 °.

The cover sheet according to the present invention includes, for example, polyester melamine, alkyd melamine, acrylic melamine, acrylic urethane, acrylic
Coatings such as polyacid curing agents, especially on the side of the car body where impacts such as bumpers and pebbles with many curved surfaces are large.
It can be preferably used for transporting painted steel sheets and decorative plywood for home appliances and the like and for surface protection after assembling home appliances. In the application, the cover sheet according to the present invention can be superposed and adhered on a sheet for protecting a coating film or a surface including a conventional one, so that generation of abrasion due to a collision object or the like can be more reliably prevented.

[0043]

Example 1 A low-density polyethylene (Nippon Polychem, Novatec L) was applied to one side of a polyethylene foam sheet (Lytron, manufactured by Sekisui Chemical Co., Ltd.) having a thickness of 1 mm and having an uneven structure on the surface.
D) 100 parts (parts by weight, hereinafter the same), 9 parts of titanium oxide (manufactured by Ishihara Sangyo Co., Ltd., Taipaque), 0.8 parts of an ultraviolet absorber (manufactured by Ciba Specialty Chemicals, Tinuvin 326) and a hindered amine light stabilizer (Ciba) Specialty Chemicals Co., Ltd., Chimasorb 944) Extruded and kneaded 0.2 part of the kneaded material to form a laminated layer having a thickness of 15 μm, and 100 parts of polyisobutylene having a weight average molecular weight of 870,000 was formed on the other surface of the foamed sheet. A toluene solution containing 20 parts of 30,000 polyisobutylene was applied,
After heating for 30 minutes, an adhesive layer having a thickness of 30 μm was formed to obtain a cover sheet.

Example 2 100 parts of SEPS (manufactured by Kuraray Co., Ltd., Septon 2063)
Hydrogenated liquid polyisoprene (KIRARE, LIR-29
0) Example using an adhesive layer forming material composed of a kneaded material of 40 parts and 20 parts of a hydrogenated petroleum resin (Alcon P-100, manufactured by Arakawa Chemical Co.), and a laminated layer forming material composed of polyethylene (Novatec LD). Two layers were extruded on one side of the foam sheet according to No. 1 to obtain a cover sheet having a 30 μm thick adhesive layer outside a 5 μm thick polyethylene laminate layer.

Example 3 A laminate layer forming material made of a kneaded polyethylene according to Example 1, a foaming layer forming material made of a foaming compound (Polythrene, manufactured by Eiwa Kasei Co., Ltd.), and a Clayton G1657 made by SEBS (Shell Chemical Co., Ltd.) ) 100 parts, a kneaded product of 20 parts of hydrogenated petroleum resin (Alcon P-100) and 10 parts of polybutene (HV-50, manufactured by Nippon Petrochemical Co., Ltd.) were extruded into three layers, and the thickness was extruded. A cover sheet having a polyethylene laminate layer having a thickness of 10 μm on one side of a foam layer having a thickness of 0.5 mm and an adhesive layer having a thickness of 30 μm on the other side was obtained.

Comparative Example 1 A cover sheet was obtained in the same manner as in Example 1 except that a polyethylene film having a thickness of 60 μm and a smooth surface was used instead of the foamed sheet.

Comparative Example 2 A cover sheet was obtained in the same manner as in Example 2, except that a polyethylene film having a thickness of 1 mm and a smooth surface was used instead of the foamed sheet.

Comparative Example 3 A cover sheet was obtained according to Example 1, except that an embossed polyethylene film having a thickness of 60 μm was used instead of the foam sheet.

Evaluation Test The cover sheets obtained in Examples and Comparative Examples were adhered to an acrylic / melamine-based coating film at room temperature via the adhesive layer, and the coating film was not damaged in a chipping test with No. 6 silica sand, or 60 The film was examined for the presence of steps (cover marks) when peeled after standing at 7 ° C. for 7 days. Further, the cover sheet is adhered to the acrylic / melamine-based coating film through the adhesive layer by forming a bag-like void at normal temperature and adhering to the void. The diffusivity was examined by the presence or absence of water in the part. When there is no water, there is diffusivity, and when there is, it means that there is no diffusivity.

The results are shown in the following table. The table also shows the surface roughness Ra and Rmax on the outer surface of the adhesive layer. Ra Rmax Damage Step Diffusibility Example 1 30 80 No No No Yes Example 2 30 80 No No No Yes Example 3 10 60 No No No Yes Comparative Example 1 5 15 Yes No No Comparative Example 2 1 10 No Yes No No Comparative Example 3 10 50 Yes Yes Yes

From the table, it can be seen from the examples that the coating film is not damaged by pebbles or the like by having a support substrate made of a resin foam and an adhesive layer having a roughened outer surface. It can be seen that the infiltrating rainwater diffuses and volatilizes without leaving any cover marks. Further, an attempt was made to apply an adhesive cover to a coating tube having a radius of 50 cm.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Keiji Hayashi 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation (72) Inventor Takeshi Sano 1-2-1-2 Shimohozumi, Ibaraki-shi, Osaka No. Nitto Denko Corporation (72) Inventor Yuki Kobayashi 1-1-2 Shimohozumi, Ibaraki City, Osaka Prefecture Nitto Denko Corporation (72) Kenichi Shibata 1-1-2 Shimohozumi, Ibaraki City, Osaka Prefecture Nitto Denko Corporation (72) Inventor Takeshi Inoue 1-1-2 Shimohozumi, Ibaraki City, Osaka Prefecture Nitto Denko Corporation (72) Masayoshi Natsume 1-1, Shimohozumi Ibaraki City, Osaka Prefecture No. 2 Nitto Denko Corporation (72) Inventor Takaki Oyama 1-1-2 Shimohozumi, Ibaraki City, Osaka Prefecture Nitto Denko Corporation (72) Inventor Koharu Matsui 4-171 Higashi Hachiman, Hiratsuka City, Kanagawa Prefecture issue Nishi Paint Co., Ltd. (72) Inventor Yu Akagi 4-17-1, Higashihachiman, Hiratsuka City, Kanagawa Prefecture Inside Kansai Paint Co., Ltd. (72) Inventor Takeshi Takeshi 33-1, Kanzakicho, Amagasaki City, Hyogo Prefecture Kansai Paint Co., Ltd. (72) Inventor Hiroshi Ueda 33-1 Kanzakicho, Amagasaki-shi, Hyogo Kansai Paint Co., Ltd. F-term (reference) 4F100 AA21 AK01A AK01C AK01D AK02 AK03B AK03J AK04 AK04J AK06 AK09 AK09B AK09J AK12B AK12 AK28BAKB AK12B AN02B AR00B AT00A AT00C AT00D BA02 BA03 BA04 BA07 BA10A BA10B BA10C CA07 DD07 DD07B DJ01 DJ01A EH20 EH23 GB32 GB48 JK06 JK14 JL13B YY00B 4J004 AA05 AA07 AA10 AA14 AB01 CB04 CC02 CC03 CE02 FA04 GA01

Claims (6)

[Claims] 1. A cover sheet comprising an adhesive layer having a roughened outer surface provided on one side of a support base made of a resin foam. 2. The cover sheet according to claim 1, wherein the surface roughness of the outer surface of the adhesive layer satisfies one or both of 10 μm or more based on Ra or 30 μm or more based on Rmax. 3. The cover sheet according to claim 1, wherein the support substrate has a laminate layer on one or both surfaces thereof, and has an adhesive layer on the laminate layer surface or the surface without the laminate layer. 4. The method according to claim 1, wherein the base polymer forming the adhesive layer is polyisobutylene, butyl rubber, A
・ B ・ A type styrene block polymer, A ・ B ・ C type styrene / olefin crystal type block polymer, CB
A cover sheet comprising one or more of a C-type olefin crystal block polymer, a random copolymer of styrene and a diene hydrocarbon, or an olefin polymer. 5. The cover sheet according to claim 1, wherein the support base material and the adhesive layer are simultaneously formed by a multi-layer extrusion foaming method of two or three or more layers. 6. The method according to claim 1, wherein the wavelength is 190-3.
A cover sheet having a transmittance of 70 nm ultraviolet rays of 5% or less.