JPS61108685A - Self-adhesive composition for surface protective sheet - Google Patents

Abstract

PURPOSE:To provide the titled adhesive compsn. which shows little change with time of bonding strength even when applied temporarily to a plate to be protected and left standing for a long period and can be peeled off readily, prepared by adding polyalkylene glycol to a pressure-sensitive adhesive compsn. CONSTITUTION:A fatty acid ester of polyalkylene glycol is added to a pressure sensitive adhesive compsn. in such an amt. that a surface protective material coated with the compsn. may have an ASTM 180 deg. peeling test value of about 10-100g/20mm, although the amount varies depending on the compatibility with a plate to be protected, adhesion properties, surface roughness, etc. Usually the ester is added in 0.001-10pts.wt. to 100pts.wt. pressure-sensitive adhesive compsn. The ester should pref. have an M.W. of 200-10,000.

Description

[Detailed description of the invention] [Industrial application field] The present invention is applicable to resin plates (polyvinyl chloride, polycarbonate,
A surface protection sheet used by adhering to a resin name plate (hereinafter also referred to as a protected plate) that uses a plastic plate (such as polymethacrylate, etc.), especially a resin plate as an adherend, and has its surface printed, etc. It relates to an adhesive composition for film or tape (hereinafter also referred to as surface protection material),
In particular, the present invention relates to an adhesive composition that has suitable releasability even when the surface protection material is bonded to the plate to be protected and stored for a long period of time.

[Conventional technology]

2. Description of the Related Art Conventionally, protective sheets having a pressure-sensitive adhesive layer provided on one side of paper, plastic film, etc., have been widely used mainly for the purpose of protecting the surface of a board to be protected.

In addition, recently, resin nameplates and the like have been made using a resin plate as a base material and having the surface thereof partially or completely printed. These resin plates, printing inks, etc. are very easily damaged during transportation, processing, etc., so a surface protection material is bonded to them to protect their surfaces. However, conventional adhesives for surface protection materials have a problem in that their adhesive strength increases significantly over time, making it difficult to remove the surface protection material from the protection plate. In particular, depending on the type of printing ink and drying conditions for resin plates (especially polyvinyl chloride containing plasticizers) and resin nameplates, in extreme cases, adhesive may be left on the surface of the protective plate when the surface protection material is removed. It often happens that printing ink remains or peels off.

As a means to solve this problem,
No. 4 discloses a pressure-sensitive adhesive composition for a surface protection sheet in which 0.5 to 10 parts by weight of a phosphoric acid ester or a derivative thereof is added to 100 parts by weight of the pressure-sensitive adhesive composition.
-107332 proposes an adhesive composition for surface protection materials in which 0.01 to 10 parts by weight of an amine surfactant is added to 100 parts by weight of the pressure-sensitive adhesive composition.
These are effective only on metal plates and acrylic coated plates, and are not effective on resin plates (resin nameplates).

[Problem that the invention seeks to solve]

The object of the present invention is to provide an adhesive composition for a surface protection material that has extremely little change in adhesive strength and can be easily peeled off even if it is temporarily attached to a board to be protected, especially a resin board (resin nameplate) and left for a long period of time. It is about providing something.

[Means for solving problems]

The present inventors have conducted extensive research in order to solve such technical problems, and have found that a surface protection material using a pressure-sensitive adhesive containing a specific compound, namely polyalkylene glycol fatty acid ester, has been developed. It has been found that even if the adhesive is temporarily attached to a protective plate and left for a long period of time, there is little change in adhesive strength and the adhesive strength can be maintained at a level that allows easy peeling.

The present invention was completed based on this knowledge, and consists of an adhesive composition for surface protection materials, which is made by blending a polyalkylene glycol fatty acid ester into a pressure-sensitive adhesive composition.

The pressure sensitive adhesive used in the present invention may be one conventionally used in this field, such as rubber and/or
Alternatively, those containing synthetic resin as a main component (eg, natural rubber, polyisobutylene, isoprene, synthetic rubber containing acrylic ester as a main component, etc.) are exemplified.

Polyalkylene glycol used in the present invention.

Fatty acid esters preferably have a molecular weight of 200 to 10,000. Examples of fatty acids include stearyl, oleyl, lauryl, and bovine fatty acids. Examples of alkylenes include those having 2 to 6 carbon atoms, such as ethylene, propylene, butylene, amidino, and hexylene. are preferred, and specific examples include polypropylene glyconyl distearate, polyethylene glycol dioleate, polypropylene glycol monostearate, polyethylene glycol bovine fatty acid ester, and polyethylene glycol oleate.

The amount of polyalkylene glycol fatty acid ester added is
Although it varies depending on the compatibility with the board to be protected, adhesiveness, roughness, etc., in general, the value of the 180 degree peel test based on JIS ASTM-100 of the surface protection material coated with the adhesive composition. However, in general, it is sufficient to blend the adhesive in an amount sufficient to have an adhesive strength of about 10 to 20 m in width.
The polyalkylene glycol fatty acid ester is used in an amount of 0.001 to 10 parts by weight, preferably 0.3 to 2 parts by weight, per 100 parts by weight of the pressure-sensitive adhesive composition. If the blending amount of the polyalkylene glycol fatty acid ester is less than 0.001, a uniform thin layer of the polyalkylene glycol fatty acid ester cannot be formed, and the adhesive strength increases over time, making it difficult to peel. Furthermore, if 2 parts by weight or more is added, the effect of adding the polyalkylene glycol fatty acid ester will be saturated, and if 10 parts by weight or more is added, the original adhesive force of the adhesive will not be obtained.

In the present invention, conventionally known supports are used as the support on which the pressure-sensitive adhesive composition layer is provided, and specific examples include plastic supports such as polyvinyl chloride, polyethylene, polypropylene, and polyester, and paper. Can be mentioned.

In connection with the present invention, surface protection plates include metal plates such as stainless steel plates and aluminum plates, resin plates (including resin name plates whose surfaces are printed etc. using resin plates as adherends),
Although known adhesive compositions such as glass plates are exemplified, the adhesive composition according to the present invention has excellent effects even on resin plates (resin nameplates) in which conventionally proposed adhesive compositions have no effect. Therefore, the adhesive composition of the present invention is preferably used as an adhesive for surface protection materials for such resin plates.

A surface protection material can be manufactured by forming the adhesive composition of the present invention on the above-mentioned support by a known method such as coating.

This surface protection material can be temporarily attached to the protected board as an easily peelable surface protection material by bringing it into contact with the board to be protected and pressing it with a rubber roller, etc., and can sufficiently achieve its purpose. .

[Action/Effect]

The adhesive composition of the present invention can be applied to a support in the form of a film, sheet, or tape to serve as a surface protection material, and even if it is temporarily attached to a board to be protected and left for a relatively long period of time,
Changes in adhesive strength over time are extremely small, and the unique effect is that the adhesive strength is maintained to the extent that it can be easily peeled off.

Although the mechanism by which the present invention prevents the increase in adhesive strength due to aging is not theoretically clear, by adding polyalkylene glycol fatty acid ester, the polyalkylene glycol fatty acid ester is created between the adhesive composition and the board to be protected. A type of non-adhesive Wt in which the surfactant is continuous or discontinuous.
It is thought that it forms an IllI-like substance and prevents the increase in adhesive strength, and the area of this thin film-like substance changes with time and increases to a certain area, indicating that it has the function of inhibiting the increase in adhesive strength due to changes over time. It is presumed that a surface protection material that maintains a suitable adhesion force can be obtained.

Next, the present invention will be explained in more detail with reference to Examples.

In addition, parts in the text indicate parts by weight.

Example 1 Acrylic rubber (A) 1 solution polymerized at the following Zummer ratio
00 parts and 3 parts of a diisocyanate crosslinking agent (trade name: Coronate, manufactured by Nippon Polyurethane Industries, Ltd.) was obtained.

Acrylic rubber (A) 2 Ethylhexyl acrylate 100 parts Ethyl acrylate 70 parts Acrylic acid
5 parts benzoyl peroxide 1 part toluene
300 parts To 100 parts of this composition, 1 part of polyethylene glycol oleate (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name: Neugen ES-120) was added to obtain an adhesive composition for surface protection materials. This composition was made into a toluene solution with a solid content of 25%, and a polyethylene film (manufactured by Mitsui Polychemical Co., Ltd., product name Mirason 16, made into a film using an extruder) was subjected to corona treatment to a thickness of 0.06 + u. After heating and drying (80° C. x 2 minutes), the coating was coated on a surface to a thickness of 10 μm and dried to obtain a sample piece. This sample piece was cut into a polyvinyl chloride plate (manufactured by Tsutsunaka Plastic, trade name R-1700).
), and the increase in adhesive strength due to changes over time during storage in a constant temperature room at 40° C. was measured. Further, printing ink (manufactured by Nagase Screen Co., Ltd., trade name: Vignate Black) was coated on the polyvinyl chloride plate so that the thickness after drying (at room temperature x 24 hours) was 5 μm and dried to obtain a protective plate. Table 1 shows the results of measuring the increase in adhesive strength due to aging, similar to polyvinyl chloride boards.
In addition, the surface tension of the printed surface using the composition of the present invention was measured using the standard solution used in the wettability test method for polyethylene and polypropylene films described in JIS K-6768, and the results are shown in Table 1. It was shown to.

Example 2 Polyethylene glycol distearate ester (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name Neugen D5) was added to 100 parts of a pressure-sensitive adhesive composition mainly composed of polyisobutylene (manufactured by Esso Standard Sekiyu Co., Ltd., trade name Vistanex MML-100).
601) was added to obtain an adhesive composition for surface protection materials. A toluene solution of this composition with a solid content of 15% was mixed with polypropylene resin (manufactured by Chisso Corporation, trade name Chisso-8377) 9
0 parts and 10 parts of polyethylene resin (manufactured by Nippon Unicar Co., Ltd., trade name DFD-5505) were mixed, and the resulting mixed resin was extruded using a melt extruder to obtain a 50 μm sheet. One side of this sheet has a thickness of 10μ after drying (80℃ x 2 minutes).
A sample piece was obtained by coating and drying the sample. Table 1 below shows the results of measuring the adhesive strength over time using the same procedure as in Example 1. Also, the surface tension of the printed surface using the composition of the present invention was measured using polyethylene and polypropylene as specified in JIS K-6768. The film wetting test was conducted in the same manner using the standard solution used, and the results are shown in Table 1.

Example 3 100 parts of first grade natural rubber (60 minutes masticated product), 2 parts of diisocyanate crosslinking agent (manufactured by Nippon Polyurethane Industries Co., Ltd., trade name: Coronate), anti-aging agent (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer NW) Pressure-sensitive adhesive composition mainly consisting of 3 parts @1
00 parts of polyethylene glycol dioleate (manufactured by Sanyo Chemical Industries, Ltd., trade name Ionet 1-Do-200)
) was added to obtain an adhesive composition for surface protection materials. A toluene solution of this composition having a solid content of 20% was applied to a commercially available polyester film having a thickness of 25 μm and dried so that the adhesive thickness after drying was 10 μm.

Table 1 below shows the measurement results of the adhesive force measured over time by the same operation as in Example 1.

In addition, the surface tension of the printed surface using the composition of the present invention was determined by JI
The test was carried out in the same manner as in the wetting test method for polyethylene and polypropylene films described in SK-6768 using the standard solution used, and the results are shown in Table 1.

Comparative Examples 1 to 3 In Comparative Examples 1 to 3, five sample pieces were prepared without adding the polyalkylene glycol fatty acid ester in Examples 1 to 3, and the measurement results were recorded. In addition, the compositions of the present invention were used. The surface tension of the printed surface is determined by JIS K-676.
The test was carried out in the same manner as described in 8 using the standard solution used in the wetting test method for polyethylene and polypropylene films, and the results are shown in Table 1.

Comparative Examples 4 to 5 One part each of polyethylene octadecylamine and alkylphenol type phosphate ester as surfactants were added to 100 parts of the pressure-sensitive adhesive compositions of Examples 1 and 2, and the adhesive strength was adjusted in the same manner as in Example 1. We measured the rise in The results are shown in Table 2.

As is clear from the results shown in Table 11 and Table 2, by adding polyalkylene glycol fatty acid ester to the pressure-sensitive adhesive composition, the increase in adhesive strength of the adhesive composition over time can be suppressed and maintained. I found out. Furthermore, this effect cannot be obtained even when other surfactants are added, and only surface protection materials coated with an adhesive composition for surface protection materials containing polyalkylene glycol fatty acid ester are effective in preventing increases in adhesive strength. was also found to be particularly significant.

(Margin below)

Claims (2)

[Claims] (1) An adhesive composition for surface protection materials comprising a pressure-sensitive adhesive composition containing a polyalkylene glycol fatty acid ester. (2) The adhesive composition for a surface protection material according to claim (1), wherein the amount of polyalkylene glycol fatty acid ester blended is 0.001 parts by weight to 10 parts by weight.