JP2001262106A - Pressure-sensitive adhesive composition, and pressure- sensitive adhesive tapes or pressure-sensitive adhesive sheet for surface protection formed by using the composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure-sensitive adhesive composition excellent in initial adhesion to a roughly surfaced steel sheet coated with vinyl chloride, scarcely increasing in adhesiveness after adhered, and having small peeling strength when measured in a region of high-speed peeling rate, especially at such a rate as applied when practically peeled-off, and to provide pressure- sensitive adhesive tapes and a pressure-sensitive adhesive sheet for surface protection formed by using the composition. SOLUTION: This pressure-sensitive adhesive composition contains at least 100 pts.wt. of a styrene-ethylene/propylene-styrene(SEPS) block copolymer, 10-100 pts.wt. of a hydrogenation type tackifier having a softening pint of >=110 deg.C, and 0.05-10 pts.wt. of an isocyanate-based compound. The pressure- sensitive adhesive tapes and the pressure-sensitive adhesive sheet for surface protection are each obtained by applying the pressure-sensitive adhesive composition to one of both surfaces of a support material consisting of a plastic film to form the pressure-sensitive adhesive layer.

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 which has good initial adhesiveness, and has a small increase in adhesive strength with time and excellent removability. The present invention also relates to pressure-sensitive adhesive tapes or surface-protecting pressure-sensitive adhesive sheets using the pressure-sensitive adhesive composition, particularly, metal plates such as stainless steel plates and aluminum plates, painted metal plates and resin plates, transporting and processing glass plates, and the like. The present invention relates to a pressure-sensitive adhesive sheet for surface protection used for a pressure-sensitive adhesive sheet for surface protection, which is attached for surface protection when curing. More specifically, it is an adhesive sheet for protecting the surface of a so-called PVC steel sheet, in which the surface of the steel sheet is coated with a coating film made of a vinyl chloride resin. The present invention relates to an adhesive sheet for use.

[0002]

2. Description of the Related Art Conventionally, PVC steel sheets have been very often used for decorative steel sheets for home appliances and building materials. In the case of decorative steel sheets, such as PVC steel sheets, in order to prevent the surface from being damaged or contaminated by collision of small objects, chemicals, etc. in the stage before use such as transport, processing, etc. A surface protection sheet provided with a pressure-sensitive adhesive layer is put on the cover, and after achieving the above-mentioned purpose, this is peeled off and used for use.

Generally, a protective adhesive sheet for a PVC steel sheet includes:
When a highly polar adhesive such as an acrylic adhesive is used, it is possible to obtain a sufficient adhesive strength at the initial stage, but the adhesive strength increases with time, due to the high polarity of the vinyl chloride resin. In some cases, peeling was difficult.

For this reason, a protective adhesive sheet for a PVC steel sheet is mainly composed of a polyisobutylene (PIB), which is mainly composed of a styrene-ethylene-butylene-styrene (SEBS) block copolymer and to which a tackifier is added. Synthetic rubber-based pressure-sensitive adhesives such as pressure-sensitive adhesives as main components are generally used. Since these synthetic rubber-based pressure-sensitive adhesives have a smaller polarity as compared with acrylic pressure-sensitive adhesives, they have a feature that they do not easily cause a heavy peeling phenomenon even on a polar adherend such as a polyvinyl chloride steel sheet.

However, in the case of these pressure-sensitive adhesives using a relatively low-polarity synthetic rubber-based pressure-sensitive adhesive, a rough surface having unevenness on the surface of a coating film by a surface treatment such as a hairline process, a mat process, and an emboss process even in a PVC steel sheet. PVC steel sheet (especially center line average roughness (see JIS-B0601) Ra> 2
(It has a rough surface of μm), it is difficult to use from the initial stage because bonding at room temperature does not provide sufficient adhesive strength, and in use, heating the rolls and adherends during bonding I had to.

In addition, the same synthetic rubber-based pressure-sensitive adhesive styrene-ethylene-propylene-styrene (SEPS) block copolymer is used, and a tackifier and a softener are mixed with the same to improve the adhesiveness. Was previously known. However, in this method, although the adhesiveness increases with an increase in the amount of the softening agent, there are problems such as the cohesive force of the pressure-sensitive adhesive itself being reduced to cause adhesive residue and heavy peeling over time.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a good initial adhesive property, and a re-peeling property with a small increase in adhesive force over time. An object is to provide an excellent pressure-sensitive adhesive composition. Another object of the present invention is to provide excellent initial adhesion (adhesion after bonding at room temperature) to a PVC steel sheet, particularly to a roughened PVC steel sheet having irregularities on the surface, and an adhesive force after the bonding. An object of the present invention is to provide a pressure-sensitive adhesive sheet for surface protection, which has a small ascending property and a small peeling strength particularly in a high-speed peeling region (tensile speed: 10 to 50 m / min) corresponding to an actual peeling speed. I do.

[0008]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a specific synthetic rubber-based adhesive has a softening point of 120.
It has been found that the above-mentioned object can be achieved by a pressure-sensitive adhesive composition comprising a hydrogenated resin having a temperature of at least ° C or higher and an isocyanate-based compound and a pressure-sensitive adhesive sheet for surface protection using the same.

That is, the present invention relates to at least styrene-
100 parts by weight of an ethylene / propylene-styrene (SEPS) block copolymer, 10 to 100 parts by weight of a hydrogenated tackifier having a softening point of 110 ° C. or more, and 0.05 to 10 parts by weight of an isocyanate compound The present invention relates to a pressure-sensitive adhesive composition containing (claim 1). In this pressure-sensitive adhesive composition, the preferred embodiment is that the isocyanate compound is an aromatic compound (claim 2).

Further, an adhesive tape (Claim 3) or an adhesive sheet for surface protection (Claim 4) in which an adhesive layer comprising the adhesive composition is formed on one surface of a plastic film support substrate, An adhesive sheet for protecting a surface, which is for protecting a vinyl chloride laminated steel sheet (claim 5);
An object of the present invention is to provide a pressure-sensitive adhesive sheet for protecting a surface, which is used for protecting a polyvinyl chloride laminated steel sheet whose surface is a rough surface having a center line average roughness Ra> 2 μm.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The pressure-sensitive adhesive composition of the present invention comprises at least styrene-ethylene-propylene-styrene (SE
PS) 100 parts by weight of a block copolymer and a softening point of 11
10 to 100 parts by weight of a hydrogenated tackifier at 0 ° C. or higher, and 0.05 to 10 parts by weight of an isocyanate compound,
It is characterized by including.

The SEPS block copolymer used in the present invention is generally a triblock copolymer represented by ABA or a triblock copolymer represented by ABA and A A mixture with a diblock copolymer represented by -B, wherein A is a styrene polymer block, and B is an ethylene / propylene copolymer block. The preferred weight ratio of the styrene polymer block A and the ethylene / propylene copolymer block B is A / B = 5 / 95-30.
/ 70, preferably 10/90 to 25/75. If the styrene content is less than 5% by weight, the handleability as a resin will be poor, and if it exceeds 30% by weight, the resin will be hard and both are not preferred.

In the present invention, it is preferable to use an ABA triblock copolymer as the SEPS block copolymer, but it is possible to use a partially mixed AB diblock copolymer. No, generally manufactured A-
The BA triblock copolymer partially contains an AB diblock copolymer, and a commercially available ABA triblock copolymer can be used as it is.

Examples of these SEPS block copolymers include “Septon 2023” (Kuraray Co., Ltd.) (styrene block content 13% by weight) and “Septon 2043”.
(Styrene block content 13% by weight), "Septon 20
63 "(styrene block content 13% by weight)," Septon 2005 "(styrene block content 20% by weight) and the like can be used, but the present invention is not limited thereto.

These can be used alone or in combination of two or more. In particular, by blending block polymers having different styrene block contents, the initial adhesive strength and cohesive strength can be balanced, which is preferable. Also, all SEPS
The styrene block content in the block copolymer is preferably 20% by weight or less, and the styrene block content is 2% by weight.
If the amount exceeds 0% by weight, the initial adhesive strength may be poor.

In the present invention, the tackifier has a softening point of 1
The temperature is 10 ° C. or higher, preferably 120 to 150 ° C., and a hydrogenated tackifier is used. By setting the softening point to 110 ° C. or higher, a layer having a high concentration of the tackifier exists on the outermost surface of the pressure-sensitive adhesive due to the high polar effect of the tackifier, and thus the adhesiveness is secured without using a softener. In addition, it is possible to obtain a pressure-sensitive adhesive having good peelability in a high-speed region (tensile speed: 10 to 50 m / min) such as an actual peeling speed. Further, by using a hydrogenated type tackifier, a pressure-sensitive adhesive excellent in weather resistance can be obtained.

Examples of these tackifiers include hydrogenated alicyclic petroleum resins, hydrogenated terpene resins, hydrogenated rosin resins, hydrogenated rosin ester resins, hydrogenated terpene phenol resins, hydrogenated cumarone Indene-based resins and the like, for example, a hydrogenated alicyclic petroleum resin “Arukawa P125” (softening point 125 ° C.) manufactured by Arakawa Chemical Industries, Ltd .;
“Alcon P-140” (softening point 140 ° C), “Clearon P”, a hydrogenated terpene resin manufactured by Yasuhara Chemical Co., Ltd.
−125 ”(softening point of 125 ° C.), but is not limited thereto. One or more of these tackifiers can be used.

In the present invention, the number of added tackifiers is 10 parts by weight per 100 parts by weight of the SEPS block copolymer.
-100 parts by weight, preferably 20-60 parts by weight. When the amount of the tackifier is less than 10 parts by weight, the adhesive strength at the initial stage and after the elapse of time is poor. When the amount exceeds 100 parts by weight, cohesive strength may be insufficient or the adherent may be contaminated by the tackifier.

The present invention is characterized in that an isocyanate compound is added to the pressure-sensitive adhesive. By adding an isocyanate compound to the pressure-sensitive adhesive, it has excellent initial adhesion to the roughened PVC steel sheet (adhesion after bonding at room temperature), and sufficient adhesion from the beginning even when bonding at room temperature. You can gain power.

These isocyanate compounds are particularly preferably aromatic compounds because compatibility with the SEPS copolymer is improved. For example, tolylene diisocyanate (TDI), 2,4-tolylene diisocyanate dimer Body, naphthylene-1,5-diisocyanate (ND
I), o-tolylene diisocyanate (TODI), diphenylmethane diisocyanate (MDI), triphenylmethane triisocyanate, tris- (p-isocyanatophenyl) thiophosphite, polymethylene polyphenylisocyanate, and the like. However, the present invention is not limited to this. One or more of these isocyanate compounds may be used.

The above-mentioned isocyanate compound is available as a commercial product, for example, “Coronate-L” having a tolylene diisocyanate structure manufactured by Nippon Polyurethane Co., Ltd., diphenylmethane diisocyanate (MD
I) Millionate MR-300 manufactured by Nippon Polyurethane Co., Ltd. having a structure can be preferably used.

The amount of the isocyanate compound added is SEP
The amount is preferably 0.05 to 10 parts by weight, and more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the S copolymer. If the isocyanate-based compound is less than 0.05 parts by weight, the initial and after-time adhesion is poor, and if it exceeds 10 parts by weight,
There is a possibility that the cohesive strength is insufficient or the adherend is contaminated by the tackifier.

In the present invention, a small amount of additives such as an ultraviolet absorber, a light stabilizer, a radical scavenger and an antioxidant may be added to the pressure-sensitive adhesive in addition to the above. Is added. In addition, if necessary, various compounding agents such as polymers, fillers, slip agents, antistatic agents, pigments, dyes and stabilizers may be added as long as the effects of the present invention are not impaired.

The present invention provides a pressure-sensitive adhesive tape or a surface-protecting pressure-sensitive adhesive sheet in which a pressure-sensitive adhesive layer comprising the above-mentioned pressure-sensitive adhesive composition is formed on one surface of a plastic film supporting substrate. Particularly, the present invention provides a pressure-sensitive adhesive sheet for surface protection which is suitably used for protection of a polyvinyl chloride laminated steel sheet, more specifically, a polyvinyl chloride laminated steel sheet having a rough surface having a center line average roughness Ra> 2 μm (generally up to 6 μm). is there.

The thickness of the pressure-sensitive adhesive layer may be determined as appropriate,
Generally, it is 5 to 40 μm, preferably 5 to 20 μm.

The plastic film supporting substrate used for the pressure-sensitive adhesive tapes or surface-protecting pressure-sensitive adhesive sheets of the present invention is not particularly limited, and polyolefin resins, polyvinyl chloride resins, polyester resins and the like can be used. However, it is particularly preferable to use a polyolefin-based resin because no toxic gas is generated even if it is incinerated after use, and there is little problem in back surface treatment. As the polyolefin resin, for example, low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-α-olefin copolymer, propylene-α-olefin copolymer,
Examples include an ethylene-vinyl acetate copolymer, an ethylene-n-butyl acrylate copolymer, an ethylene-methyl methacrylate copolymer, polypropylene, polyethylene, polypropylene, and a polyethylene-polypropylene blend film. These may be a single layer, a film or a laminated film. In addition, a light stabilizer, an ultraviolet absorber, an antioxidant, a filler, a lubricant, and the like can be added to these plastic film support bases as necessary.

The thickness of the supporting substrate is generally from 20 to 300.
μm, preferably about 20 to 100 μm, but is not limited thereto.

In order to increase the adhesive strength (anchoring force) with the pressure-sensitive adhesive layer on the plastic film supporting substrate used in the present invention, one surface of the substrate film is subjected to a surface treatment such as corona treatment or plasma treatment or an undercoating treatment. May be applied.

The pressure-sensitive adhesive tapes or pressure-sensitive adhesive sheets for surface protection of the present invention are generally wound into a roll with the pressure-sensitive adhesive layer inside, but a support base is required to facilitate rewinding. A release treatment may be performed on the back surface of the material. The release agent used is not particularly limited, and examples thereof include a long-chain alkyl type, a fluorine-containing long-chain alkyl type, and a silicone type.

The pressure-sensitive adhesive tapes or pressure-sensitive adhesive sheets for surface protection according to the present invention are a SEPS block copolymer having a softening point of 11
A pressure-sensitive adhesive solution prepared by dissolving a hydrogenated tackifying resin at 0 ° C. or higher, an isocyanate-based compound and, if necessary, the above components in a solvent such as toluene or ethyl acetate, is directly applied to a supporting substrate, and heated. It is manufactured by a method such as drying to form a sheet, or coating on a separator, drying by heating, and then transferring onto a supporting substrate. It can also be produced by a molding method such as hot melt type, coextrusion and the like.

[0031]

The pressure-sensitive adhesive composition of the present invention is a pressure-sensitive adhesive composition having excellent initial adhesiveness to a PVC steel sheet and excellent in re-peeling property with little increase in adhesive force with time. is there.
Accordingly, the pressure-sensitive adhesive composition is particularly useful as a pressure-sensitive adhesive composition for a surface protection material of a roughened PVC steel sheet having irregularities on the surface. The pressure-sensitive adhesive tapes of the present invention can be suitably used for various uses such as masking and labels. The pressure-sensitive adhesive sheet for surface protection of the present invention has a good adhesive property at the time of bonding to a PVC steel sheet, particularly a roughened PVC steel sheet having irregularities on the surface, and has a small increase in adhesive strength after bonding. In particular, since the peel strength is small in a high-speed peeling region (tensile speed: 10 to 50 m / min) corresponding to the actual peeling speed, the film can be easily peeled after use. This is suitable, for example, as a surface protection pressure-sensitive adhesive sheet to be attached to a decorative steel sheet in which a PVC steel sheet such as a home appliance or a building material is used, and the surface of the decorative steel sheet is damaged or contaminated by collision of small objects or chemicals. Can be stably prevented for a long time.

[0032]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0033]

EXAMPLES Example 1 Density d = 0.923 (see JIS K-6760), melt flow rate (MFR) 2.0 g / 10 min (JI
SK-6760) was formed using an inflation extrusion film forming machine to obtain a PE film having a thickness of 60 μm. On one side of this PE film, 100 parts by weight of "Septon 2023" manufactured by Kuraray Co., Ltd. as a SEPS block copolymer, and "Alcon P-" manufactured by Arakawa Chemical Industries, Ltd., which is a hydrogenated alicyclic petroleum resin as a tackifier. 140 "(softening point 140 ° C), 40 parts by weight, 1.0 part by weight of" Coronate L "manufactured by Nippon Polyurethane Co., Ltd. as an isocyanate-based compound, 0.5 part by weight of a sebenzotriazole-based ultraviolet absorber, hindered amine-based light stability An adhesive composition comprising 0.5 part by weight of the agent was applied so that the paste thickness became 15 μm, to obtain an adhesive sheet for surface protection.

Example 2 50 parts by weight of "Septon 2023" manufactured by Kuraray Co., Ltd., 50 parts by weight of "Septon 2005" manufactured by Kuraray Co., Ltd., manufactured by Arakawa Chemical Industries, Ltd. on one side of the PE film used in Example 1. 40 parts by weight of “Alcon P-140” (softening point 140 ° C.), “Coronate L” 0.5 manufactured by Nippon Polyurethane Co., Ltd.
Parts by weight, sebenzotriazole UV absorber 0.5
Parts, a pressure-sensitive adhesive composition comprising 0.5 parts by weight of a hindered amine light stabilizer was applied such that the paste thickness became 15 μm,
A pressure-sensitive adhesive sheet for surface protection was obtained.

Example 3 On one side of the PE film used in Example 1, 50 parts by weight of "Septon 2023" manufactured by Kuraray Co., Ltd., 50 parts by weight of "Septon 2005" manufactured by Kuraray Co., Ltd., manufactured by Arakawa Chemical Industry Co., Ltd. “Alcon P-140” (softening point 140 ° C.) 40 parts by weight, “Coronate L” 1.0 manufactured by Nippon Polyurethane Co., Ltd.
Parts by weight, sebenzotriazole UV absorber 0.5
Parts, a pressure-sensitive adhesive composition comprising 0.5 parts by weight of a hindered amine light stabilizer was applied such that the paste thickness became 15 μm,
A pressure-sensitive adhesive sheet for surface protection was obtained.

Example 4 100 parts by weight of “Septon 2063” manufactured by Kuraray Co., Ltd. and “Alcon P-140” (softening point 140 ° C.) 4 manufactured by Arakawa Chemical Industries Co., Ltd. on one side of the PE film used in Example 1.
0 parts by weight, "Coronate L" manufactured by Nippon Polyurethane Co., Ltd.
A pressure-sensitive adhesive composition comprising 0.5 parts by weight, 0.5 parts by weight of a sebenzotriazole-based ultraviolet absorber and 0.5 parts by weight of a hindered amine-based light stabilizer is applied so that the thickness of the paste becomes 15 μm, and the adhesive for surface protection is applied. I got a sheet.

Example 5 100 parts by weight of "Septon 2023" manufactured by Kuraray Co., Ltd. on one side of the PE film used in Example 1, and "Clearon P" manufactured by Yasuhara Chemical Co., Ltd. which is a hydrogenated terpene resin as a tackifier. −125 ”(softening point 125 ° C.) 40 parts by weight, Nippon Polyurethane Co., Ltd.“ Coronate L ”0.5 part by weight, sebenzotriazole UV absorber 0.5 part, hindered amine light stabilizer 0.5 part by weight The pressure-sensitive adhesive composition consisting of parts was applied so that the paste thickness was 15 μm, to obtain a pressure-sensitive adhesive sheet for surface protection.

Comparative Example 1 100 parts by weight of "Septon 2063" manufactured by Kuraray Co., Ltd. and "Alcon P-140" (softening point 140.degree. C.) 4 manufactured by Arakawa Chemical Industries, Ltd. on one side of the PE film used in Example 1.
0 parts by weight, sebenzotriazole ultraviolet absorber 0.5
A pressure-sensitive adhesive composition consisting of 0.5 parts by weight of a hindered amine light stabilizer and 0.5 parts by weight of a hindered amine light stabilizer was applied so that the paste thickness became 15 μm, to obtain a pressure-sensitive adhesive sheet for surface protection.

Comparative Example 2 On one side of the PE film used in Example 1, 100 parts by weight of "Septon 2063" manufactured by Kuraray Co., Ltd., 0.5 part by weight of "Coronate L" manufactured by Nippon Polyurethane Co., Ltd., sebenzotriazole-based A pressure-sensitive adhesive composition comprising 0.5 parts by weight of an ultraviolet absorber and 0.5 parts by weight of a hindered amine light stabilizer was applied so that the paste thickness became 15 μm, to obtain a pressure-sensitive adhesive sheet for surface protection.

Comparative Example 3 One side of the PE film used in Example 1 was 100 parts by weight of "Septon 2023" manufactured by Kuraray Co., Ltd. Arakawa Chemical Industries, Ltd. which was a hydrogenated alicyclic petroleum resin as a tackifier. 40 parts by weight of "Alcon P-100" (softening point 100 ° C), 0.5 parts by weight of "Coronate L" manufactured by Nippon Polyurethane Co., Ltd., 0.5 parts by weight of a sebenzotriazole UV absorber, hindered amine light stability An adhesive composition consisting of 0.5 part by weight of the agent is applied so that the paste thickness becomes 15 μm,
A pressure-sensitive adhesive sheet for surface protection was obtained.

Comparative Example 4 50 parts by weight of "Septon 2023" manufactured by Kuraray Co., Ltd., 50 parts by weight of "Septon 2005" manufactured by Kuraray Co., Ltd., and non-hydrogenated as a tackifier were applied to one side of the PE film used in Example 1. 40 parts by weight of “Alcon M-125” (softening point 125 ° C.) manufactured by Arakawa Chemical Industry Co., Ltd., 1.0 part by weight of “Coronate L” manufactured by Nippon Polyurethane Co., Ltd. A pressure-sensitive adhesive composition comprising 0.5 parts of a benzotriazole-based ultraviolet absorber and 0.5 parts by weight of a hindered amine-based light stabilizer was applied so that the paste thickness became 15 μm, to obtain a pressure-sensitive adhesive sheet for surface protection.

COMPARATIVE EXAMPLE 5 One side of the PE film used in Example 1 was a SEBS copolymer "Clayton G-1657" manufactured by Shell Chemical.
100 parts by weight, "Arucon P-1" manufactured by Arakawa Chemical Industries, Ltd.
40 "(softening point 140 ° C) 40 parts by weight, 0.5 parts by weight of" Coronate L "manufactured by Nippon Polyurethane Co., Ltd., 0.5 parts by weight of a sebenzotriazole ultraviolet absorber, 0.5 parts by weight of a hindered amine light stabilizer The pressure-sensitive adhesive composition consisting of parts was applied so that the paste thickness was 15 μm, to obtain a pressure-sensitive adhesive sheet for surface protection.

Comparative Example 6 90 parts by weight of butyl acrylate (BA) and 100 parts by weight of an acrylic polymer (weight average molecular weight: 400,000) on one side of the PE film used in Example 1 were mixed with Nippon Polyurethane ( "Coronate L"
A pressure-sensitive adhesive composition comprising 3.0 parts by weight, 0.5 parts by weight of a sebenzotriazole-based ultraviolet absorber and 0.5 parts by weight of a hindered amine-based light stabilizer is applied so that the thickness of the paste becomes 15 μm, and the adhesive for surface protection is applied. I got a sheet.

For each of the pressure-sensitive adhesive sheets for surface protection of Examples 1 to 5 and Comparative Examples 1 to 6, the following method was used.
The adhesive strength at the initial stage and after the aging, the floating of the sheet after the aging, and the weather resistance were examined. The results were as shown in Table 1.

(Test Method) Each pressure-sensitive adhesive sheet for surface protection was
PVC sheet "E65" manufactured by Mitsubishi Plastics, Inc. (Ra = 3.7μ)
m) was laminated at a linear pressure of 78.4 N / cm and a speed of 0.3 m / min. Thereafter, the adhesive strength and the floating of the film after the initial stage (stored at 23 ° C. for 30 minutes) and after the lapse of time (stored at 23 ° C. and 40 ° C. for one week) were confirmed. The conditions for peeling were a tensile speed of 0.3 m / min and 30 m / min, and a peel angle of 180 ° peel.

The evaluation of floating was visually determined. When no lifting was observed, ○ was evaluated when less than 30% of the entire adhered portion was lifted, and × when more than 30% of the entire adhered portion was lifted.

The weather resistance test was carried out by laminating each pressure-sensitive adhesive sheet for surface protection on a polyvinyl chloride steel sheet by the above method, and then conducting an acceleration test using a sunshine weather meter (SWM). The contamination (adhesive residue) of the adherend when the sheet was peeled off after 100 hours was visually checked, and those not contaminated were indicated as OK.

[0048]

[Table 1]

As described above, the pressure-sensitive adhesive sheets for surface protection obtained in Examples 1 to 5 all show good initial adhesiveness to a PVC steel sheet having irregularities on the surface, and the adhesive strength after aging. No rise was seen. In contrast, Comparative Examples 1-4
Does not contain the specified components or does not satisfy the specific composition, low adhesion to PVC steel sheet,
Floating from the adherend was observed over time. Further, in Comparative Example 5, adhesive residue was generated due to poor weather resistance, and in Comparative Example 6, the adhesive strength was increased with time due to the acrylic pressure-sensitive adhesive.

Continued on the front page F-term (reference) 4F100 AH03A AH03H AK01B AK02 AK02H AK04 AK04A AK04J AK07A AK07J AK12A AK12J AK64A AK64J AL02A AL05A AT00B BA02 CA07 CA16 CA16A EH46 A90 J04AJA A04 JA04 A04 JA04A04 DM001 EF192 EF282 HC16 JA09 KA26 LA06 LA08 MA10 NA12 NA19 PA23

Claims (6)

[Claims] 1. A styrene-ethylene-propylene-styrene (SEPS) block copolymer at least 100 parts by weight; a hydrogenated tackifier having a softening point of 110 ° C. or higher; 10 to 100 parts by weight; .0
An adhesive composition comprising 5 to 10 parts by weight. 2. The pressure-sensitive adhesive composition according to claim 1, wherein the isocyanate compound is an aromatic compound. 3. An adhesive tape having a pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition according to claim 1 formed on one surface of a plastic film supporting substrate. 4. A pressure-sensitive adhesive sheet for surface protection, wherein a pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition according to claim 1 is formed on one surface of a plastic film supporting substrate. 5. The pressure-sensitive adhesive sheet for protecting a surface according to claim 4, which is for protecting a polyvinyl chloride laminated steel sheet. 6. The protection of a polyvinyl chloride laminated steel sheet whose surface is a rough surface having a center line average roughness Ra> 2 μm.
The pressure-sensitive adhesive sheet for surface protection according to claim 5.