JPH11263946A - Adhesive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a adhesive sheet not remain an adhesive transfer for a long period of time without transferring a plasticizer contained in polyvinyl chloride as a base material to an adhesive. SOLUTION: This adhesive sheet has a polyvinyl chloride sheetlike base material, a primer laminated on the base material and an adhesive laminated on the primer, and the primer is composed of 100 pts.wt. of a base primer, 10-150 pts.wt. of an ultraviolet light-hardening compound and 0.1-10 pts.wt. of an ultraviolet light curing initiator, then a thickness of the primer coated film is made as 0.05-5 μm.

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 sheet using a polyvinyl chloride sheet-like substrate, and particularly to a pressure-sensitive adhesive for a long term without transferring a plasticizer contained in polyvinyl chloride as a substrate to the pressure-sensitive adhesive. The present invention relates to an adhesive sheet having no adhesive residue.

[0002]

2. Description of the Related Art Conventionally, as a pressure-sensitive adhesive sheet using a polyvinyl chloride sheet-like substrate, various primers have been known in order to maintain the adhesive force between the substrate and the pressure-sensitive adhesive layer (for example, special primers). No. 35-1831).

[0003]

However, in the above-mentioned pressure-sensitive adhesive sheet, the plasticizer contained in polyvinyl chloride as a base material migrates to the pressure-sensitive adhesive due to a change over time, resulting in a change in pressure-sensitive adhesive properties and a pressure-sensitive adhesive. However, there was a problem such as adhesive residue that the resin was peeled off from the base material.

[0004] Accordingly, an object of the present invention is to prevent the plasticizer contained in polyvinyl chloride from being used as a base material from being transferred to a pressure-sensitive adhesive so that the pressure-sensitive adhesive properties do not change over time for a long period of time. An object of the present invention is to provide a pressure-sensitive adhesive sheet having no residue.

[0005]

Means for Solving the Problems The present inventor has conducted intensive studies in view of the above, and as a result, has found that a sheet-like substrate made of polyvinyl chloride, a primer laminated on the substrate, In the pressure-sensitive adhesive sheet provided with the laminated pressure-sensitive adhesive, the primer is composed of 100 parts by weight of a base primer, 10 to 150 parts by weight of an ultraviolet-curable compound, and 0.1 part of an ultraviolet-curing initiator.
It has been found that the above problem can be solved by providing 1 to 10 parts by weight, and the present invention has been completed.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the cohesive force of the primer is increased by irradiating ultraviolet rays, thereby preventing the transfer of the plasticizer to the adhesive. If the primer coating amount is too small, the plasticizer blocking effect does not appear, and if it is too large, the ultraviolet curing speed will be slow,
The thickness is preferably 0.05 to 5.0 μm, and more preferably 0.3 to 0.8 μm.

[0007] The above-mentioned ultraviolet curable compound is adopted
The ultraviolet curing initiator that has been irradiated with ultraviolet light increases the cohesive force of the entire primer and prevents the transfer of the plasticizer. Does not contribute to the improvement of the plasticizer, the effect of inhibiting the plasticizer is reduced, and if the amount is too large, the cohesive force becomes too high and the anchor effect as a primer cannot be exerted. Therefore, preferably 10 to 150 parts by weight, more preferably 20 to 100 parts by weight. Department is good.

The UV-curable compound is preferably a functional UV-curable compound having two or more functional groups, for example, an acrylate compound, urethane acrylate, urethane acrylate oligomer and / or monomer, epoxy acrylate. , Polyester acrylate and the like.

The acrylate compound includes, for example, trimethylolpropane triacrylate, tetramethylolmethanetetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate or 1,4 -Butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, oligoester acrylate and the like.

The urethane acrylate includes, for example, polyester urethane acrylate, polyether urethane acrylate, 4-functional urethane acrylate,
There is a functional urethane acrylate.

The urethane acrylate oligomer is an ultraviolet-polymerizable compound having at least two carbon-carbon double bonds, such as a polyester compound or a polyether type polyol compound and a polyvalent isocyanate compound such as ( 2,4-tolylene diisocyanate,
2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane 4,4-diisocyanate, etc.)
Is reacted with a terminal isocyanate urethane prepolymer to give an acrylate or methacrylate having a hydroxyl group (eg, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, polyethylene glycol acrylate). , Polyethylene glycol methacrylate, etc.).

The above-mentioned epoxy acrylate is synthesized by reacting an epoxy group with acrylic acid or methacrylic acid, and includes bisphenol A type, bisphenol S type, bisphenol F type, epoxy oil type, and phenol novo. There are rack type, alicyclic type and the like.

The above-mentioned polyester acrylate is obtained by condensing acrylic acid to an OH group remaining on a polyester skeleton synthesized from a diol, a polyol and a dibasic acid to form an acrylate. For example, phthalic anhydride / propylene oxide diol / acrylic Acid, adipic acid / 1,6
-Hexanediol / acrylic acid, trimellitic acid / diethylene glycol / acrylic acid and the like.

When the above-mentioned ultraviolet curable compound is employed, it is particularly preferable that the compound has a molecular weight of 300 to 30,000.

In the present invention, the ultraviolet curing initiator is:
It is for increasing the cohesive force of the entire primer by increasing the bonding at the reaction site with the ultraviolet curable compound when receiving ultraviolet irradiation, and if the compounding ratio is too small, the curing is slow and the workability is poor, If the amount is too large, unreacted initiator remains and contamination occurs.
10 to 10 parts by weight, more preferably 1 to 5 parts by weight.

Examples of the ultraviolet curing initiator include chloroacetophenone, diethoxyacetophenone, hydroxyacetophenone, 1-hydroxycyclohexylphenylketone, α-aminoacetophenone,
2-methyl-1- (4- (methylthio) phenyl) -2
-Morpholinopropan-1-one, 2-hydroxy-
2-methyl-1-phenylpropan-1-one, 1-
(4-Isopropylphenyl) -2-hydroxy-2-
Methylpropan-1-one, 1- (4-dodecylphenyl) -2-hydroxy-2-methylpropan-1-one, mixed photoinitiator, 4- (2-hydroxyethoxy)-
Phenyl (2-hydroxy-2-propyl) ketone, allyl ketone-containing photoinitiator, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether,
Benzoin ether, benzyldimethyl ketal, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4′-methyldiphenyl sulfide, 3, 3'-
Dimethyl-4-methoxybenzophenone, methyl-O-
Benzoylbenzoate, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-
Dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, α-acyl oxime ester, α-acyloxime ester, acyl Phosphine oxide, methylphenyl glyoxylate, glyoxyester, 3-ketocoumarin, 2-ethylanthraquinone, camphorquinone, benzyl, 9,10-phenanthrenequinone, anthraquinone, dibenzosuberone, 4 ', 4 ″ -diethylisophthalophenone, Michler's ketone, cyclic photoinitiator, tetramethylthiuram monosulfide, 3,
3 ', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone and the like. Examples of the chloroacetophenone include 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 4-t
-Butyl-trichloroacetophenone and the like.

Further, in the primer according to the present invention, a photoinitiating auxiliary may be blended with the ultraviolet curing initiator as needed. Although the photoinitiator itself is not activated by ultraviolet irradiation itself, the initiation reaction is accelerated by using the ultraviolet curing initiator alone when used in combination with the ultraviolet curing initiator, and the curing reaction is made efficient. is there.

The photo-initiating assistant is mainly aliphatic,
There are aromatic amines, and specifically, triethanolamine, methyldiethanolamine, triisopropanolamine, n-butylamine, N-methyldiethanolamine, diethylaminoethyl methacrylate, Michler's ketone, 4,4′-diethylaminophenone, 4,4 ′
-Diethylaminobenzophenone, ethyl 2-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate,
Ethyl (n-butoxy) 4-dimethylaminobenzoate, 4
-Isoamyl dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, polymerizable tertiary amine,
Triethylamine, tetraethylpentaamine, dimethylaminoether and the like.

In order to start ultraviolet curing of the ultraviolet curable compound or the ultraviolet curing initiator, ultraviolet irradiation is required. The irradiation timing may be not only after lamination of the primer but before lamination of the pressure-sensitive adhesive, but also after lamination of the pressure-sensitive adhesive depending on the pressure-sensitive adhesive. The irradiation amount of the ultraviolet ray varies depending on the type of the ultraviolet curing initiator and the ultraviolet curable compound, but is preferably in the range of, for example, 20 to 500 J / cm ² (365 nm), and more preferably 50 to 150 J / cm ² (365 nm).
nm). This is because if the amount is too small, the cohesive force cannot be improved by irradiating the ultraviolet rays, and if the amount is too large, the speed of the ultraviolet irradiating line becomes slow and the productivity is deteriorated.

As the above-mentioned base primer, a conventionally known base primer can be employed, and specific examples thereof include polyisocyanate-based, polyethyleneimine-based, acrylic-based and rubber-based base primers.

As the pressure-sensitive adhesive to be laminated in the pressure-sensitive adhesive sheet of the present invention, conventionally known pressure-sensitive adhesives can be employed, and specific examples of the main components include acrylic polymers and / or elastomers. As the acrylic polymer, a conventionally known acrylic pressure-sensitive adhesive can be appropriately selected and used. Generally, a homopolymer (main monomer) and a comonomer having an acrylate ester as a main constituent monomer unit can be used. And copolymers with other functional monomers (functional group-containing monomers) and mixtures of these polymers.

Examples of the main monomer include ethyl acrylate, butyl acrylate and 2-ethylhexyl acrylate. Examples of the functional group-containing monomer include methacrylic acid, acrylic acid, itaconic acid, hydroxyethyl methacrylate, hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, acrylamide, methylol acrylamide, glycidyl methacrylate, and maleic anhydride.

Examples of the elastomer include natural rubber, synthetic isoprene rubber, SBR (styrene butadiene rubber), styrene / butadiene block copolymer, styrene / isoprene block copolymer, butyl rubber, polyisobutylene, polybutadiene, polyvinyl ether,
Silicone rubber, polyvinyl isobutyl ether, chloroprene rubber, nitrile rubber, kraft rubber, recycled rubber, styrene / ethylene / butylene / block copolymer, styrene / propylene / butylene / block copolymer, styrene / isoprene / block copolymer, acrylonitrile / butadiene copolymer , Acrylic rubber (acrylonitrile / acryl ester copolymer), methyl
There are methacrylate / butadiene copolymer, polyisobutylene / ethylene / propylene copolymer, ethylene / vinyl acetate copolymer, polyisobutylene / silicone rubber, polyvinyl isobutyl ether / chloroprene, etc. You may. In addition, an ultraviolet-curable pressure-sensitive adhesive described in JP-A-9-3286663 can also be employed.

The polyvinyl chloride sheet as a base material in the present invention is a polyvinyl chloride sheet containing a plasticizer, which is the subject of the present invention. A sheet made of another material may be laminated on the surface opposite to the surface on which the primer is laminated.
Other materials include single or multiple layers of polybutene, polybutadiene, polyurethane, ethylene-vinyl acetate copolymer, polyethylene terephthalate, polyethylene, polypropylene, and the like.

The pressure-sensitive adhesive sheet according to the present invention is stored by adhering release paper or a release sheet such as polyethylene laminated paper or release-treated plastic film onto the pressure-sensitive adhesive as required.

According to the present invention, in the pressure-sensitive adhesive sheet comprising a polyvinyl chloride sheet-like substrate, a primer laminated on the substrate, and a pressure-sensitive adhesive laminated on the primer, Characterized in that it comprises 100 parts by weight of a base primer, 10 to 150 parts by weight of an ultraviolet-curable compound and 0.1 to 10 parts by weight of an ultraviolet-curing initiator, whereby a plasticizer contained in polyvinyl chloride is used as a base material. No adhesive residue is generated for a long period of time without transferring to the adhesive.

[0027]

EXAMPLES The main compounds of the pressure-sensitive adhesives of Examples and Comparative Examples of the pressure-sensitive adhesive sheet according to the present invention and their characteristic values will be described in detail with reference to Table 1.

"Plasticizer transfer rate" in Table 1 means that only the primer was applied to the substrate, the surface of the primer was adhered to a black copy paper, and left at 50 ° C. × 2 kg load × 7 days. As a result of examining the transfer amount of the plasticizer to the gas chromatography, the transfer rate (%) of the primer was represented. The `` anchor property '' was evaluated as ○ when the adhesive was not peeled off from the base material visually when the completed adhesive tape was bonded to the stainless steel plate and then peeled off, and x when the peeled off tape was present. Things.
"Adhesive strength" indicates the adhesive strength after 20 minutes and 30 days after bonding. "Glue residue" was affixed to a stainless steel plate, left at 23 ° C. for 30 days, and when peeled off, there was no glue residue. The condition of adhesive residue is 3 at 60 ° C.
This is the result obtained in 0 days.

[0029]

[Table 1]

The pressure-sensitive adhesive sheet according to each of the examples and the comparative examples includes a sheet substrate made of polyvinyl chloride having a thickness of 70 μm, a primer laminated on the substrate and listed in Table 1; It is provided with a laminated acrylic pressure-sensitive adhesive (Olivine BPS5448 manufactured by Toyo Ink Co., Ltd.).

The other main components in Table 1 will be described. Polyacrylic (# 344 manufactured by Toyo Kagaku) is used as the base primer 100 parts by weight, Beamset 575 (manufactured by Arakawa Chemical) is used as the ultraviolet curable compound, and benzoin isopropyl is used as the ultraviolet curable initiator. Ether was used. The amount of ultraviolet irradiation is 150 J / cm ² (365 nm).

In Comparative Example 1 in which the primer coating thickness was reduced, there was a problem in all the measurement results. In Comparative Example 2 in which the primer coating thickness was increased, the amount of the primer applied was large, so that not only the production stability was lost but also the product unit price was increased. There was a problem. In Comparative Example 3 in which the ultraviolet curable compound and the ultraviolet curing initiator were not blended, there were problems in the plasticizer transfer rate, the adhesive strength, and the adhesive residue. In Comparative Example 4 in which a large amount of the ultraviolet curable compound was blended, the anchor property and adhesive residue were poor, and in Comparative Example 5 in which a large amount of the ultraviolet curable initiator was blended, the unreacted initiator was applied to the adherend. Contamination has occurred. Further, as is apparent from Examples 1 and 2, there was no significant difference between the respective characteristic values even when the blending of the ultraviolet curable compound and the ultraviolet curing initiator was changed.

[0033]

The pressure-sensitive adhesive sheet according to the present invention is a pressure-sensitive adhesive sheet comprising a polyvinyl chloride sheet-like substrate, a primer laminated on the substrate, and a pressure-sensitive adhesive laminated on the primer. The above primer is the base primer 10
0 parts by weight, 10 to 150 parts by weight of an ultraviolet-curable compound and 0.1 to 10 parts by weight of an ultraviolet-curing initiator, whereby a plasticizer contained in polyvinyl chloride as a base material is used as an adhesive. This has the effect that no adhesive residue is generated for a long time without transferring.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Chimichi Takatsu 2-13-1, Dai, Kamakura-shi, Kanagawa Prefecture Inside Toyo Kagaku Co., Ltd. (72) Inventor Takashi Hayashi 2- 13-1, Dai-dai, Kamakura-shi, Kanagawa Toyo Chemical Co., Ltd.

Claims (1)

[Claims] 1. An adhesive sheet comprising a polyvinyl chloride sheet-like base material, a primer laminated on the base material, and an adhesive laminated on the primer, wherein the primer has a base primer weight of 100%. Parts, 10 to 150 parts by weight of an ultraviolet curable compound and 0.1 to 10 parts of an ultraviolet curing initiator
A pressure-sensitive adhesive sheet having a weight part and a thickness of the primer coating film of 0.05 to 5 μm.