JPH11263947A - 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 a heat-curable compound and a heat-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 has a base primer of 100 parts by weight, a heat-curable compound of 10 to 150 parts by weight, and a heat-curing initiator of 0.1 to 0.1 parts by weight.
It has been found that the above-mentioned problems can be solved by heating these pressure-sensitive adhesive sheets with 10 parts by weight, and completed the present invention.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the cohesive force of a primer is increased by heating, thereby preventing the transfer of a plasticizer to an adhesive. If the primer coating amount is too small, the plasticizer blocking effect will not appear,
If the amount is too large, the heat-curing speed becomes slow. Therefore, the thickness is preferably 0.05 to 5.0 μm, more preferably 0.3 to 0.8 μm.

The use of the above-mentioned heat-curable compound is to increase the cohesive force of the entire primer by a heated heat-curing initiator and to prevent the transfer of the plasticizer. Even if it receives, the hardened part decreases and does not contribute to the improvement of the cohesive force, the plasticizer blocking effect decreases, and if it is too large, the cohesive force becomes too high and the anchor effect as a primer can not be exhibited,
If it is too much, it becomes sensitive to heat and light, and is cured by environmental temperature and ordinary light, resulting in poor storage stability.
The amount is preferably 0 to 150 parts by weight, more preferably 20 to 100 parts by weight.

The heat-curable compound is formed into a three-dimensional network by a heated heat polymerization initiator, whereby the entire primer is cured and the transfer of the plasticizer, which is the problem, is prevented. A low molecular weight compound having at least two or more polymerizable carbon-carbon double bonds in a molecule capable of forming a three-dimensional network is preferable, and specifically, an acrylate compound,
There are urethane acrylates, urethane acrylate-based oligomers and / or monomers, epoxy acrylates, polyester acrylate urethanes, and the like, alone or in combination.

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
A thermosetting compound having at least two carbon-carbon double bonds, for example, a polyol compound of polyester type or polyether type, and a polyvalent isocyanate compound such as 2,4-tolylene diisocyanate, 2,6
-Tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate,
A terminal isocyanate urethane prepolymer obtained by reacting diphenylmethane 4,4-diisocyanate or the like, an acrylate having a hydroxyl group, or a methacrylate such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, polyethylene glycol acrylate,
Some are obtained by reacting polyethylene glycol methacrylate or the like.

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 heat-curable compounds are employed, those having a molecular weight of 300 to 30,000 are particularly preferred.

In the present invention, the heat-curing initiator is used to increase the cohesive force of the entire primer by increasing the bonding at the reaction point with the heat-curable compound when heated. If the amount is too small, the curing is slow and the workability is inferior, and if the amount is too large, unreacted initiator remains and contamination occurs.
The amount is preferably 1 part by weight, more preferably 1 to 3 parts by weight.

The heat polymerization initiator cures the above-mentioned thermosetting compound when heated, thereby curing the entire primer and preventing the transfer of the above-mentioned plasticizer. If it is too much, it becomes sensitive to heat and hardens due to changes in environmental temperature, resulting in poor storage stability.

As the heat polymerization initiator, there are an organic peroxide derivative and an azo-based polymerization initiator, and the azo-based polymerization initiator is more preferably an organic peroxide derivative because nitrogen is generated during heating. Specific examples of the heat polymerization initiator include ketone peroxide, peroxyketal, hydroperoxide, dialkyl peroxide, diacyl peroxide, peroxyester, peroxydicarbonate, and azobisisobutyronitrile. is there. If necessary, an amine compound such as triethylamine, tetraethylpentamine, or dimethylaminoether may be used in combination as a polymerization accelerator.

The timing of heating is simultaneously performed in the drying step after application of the primer.

As the above-mentioned base primer, a conventionally known base primer can be employed, and specific examples thereof include polyisocyanate-based, polyethyleneimine-based, and acrylic-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 and rubber-based pressure-sensitive adhesives. In addition, conventionally known fillers, antioxidants, softeners, stabilizers, coloring agents, and the like can be appropriately selected and added to the pressure-sensitive adhesive.

As the acrylic polymer, a conventionally known acrylic polymer can be appropriately selected and used. Generally, a homopolymer (main monomer) having an acrylate ester as a main constituent monomer unit, and There are acrylic copolymers selected from copolymers with comonomers, 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. The above comonomer includes vinyl acetate, acrylonitrile, acrylamide, styrene,
Examples include methyl methacrylate and methyl acrylate.
Examples of the functional group-containing monomer include methacrylic acid, acrylic acid, itaconic acid, hydroxyethyl methacrylate,
Examples include 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.

Examples of the rubber-based pressure-sensitive adhesive include natural rubber, synthetic isoprene rubber, 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 polymer, acrylonitrile-butadiene copolymer, acrylonitrile-acryl ester copolymer, methyl methacrylate-butadiene copolymer, polyisobutylene-ethylene Propylene copolymer, ethylene vinyl acetate copolymer, polyisobutylene / silicone rubber, polyvinyl isobutyl ether / chloroprene, etc. It may be a mixture not only these alone product. In addition, an ultraviolet-curable pressure-sensitive adhesive described in JP-A-9-3286663 can also be employed.

The polyvinyl chloride sheet as the base material in the present invention is a polyvinyl chloride sheet containing a plasticizer, which is an object 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.

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 by comprising 100 parts by weight of a base primer, 10 to 150 parts by weight of a heat-curable compound and 0.1 to 10 parts by weight of a heat-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 Chemical Co., Ltd.) was used as the base primer of 100 parts by weight, Beam Set 575 (manufactured by Arakawa Chemical Industries) was used as the thermosetting compound, and Par Parloyl TCP manufactured by NOF Corporation as oxydicarbonate
It was adopted.

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 heat-curable compound and the heat-curing initiator were not blended, there were problems in the plasticizer transfer rate, adhesive strength, and adhesive residue. In Comparative Example 4 in which a large amount of the heat-curable compound was blended, the anchoring property and adhesive residue were poor, and in Comparative Example 5 in which a large amount of the heat-curing 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 in the respective characteristic values even when the blending of the thermosetting compound and the thermosetting 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 a thermosetting compound and 0.1 to 10 parts by weight of a thermosetting 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%. Part, heat-curable compound 1
An adhesive sheet comprising 0 to 150 parts by weight and 0.1 to 10 parts by weight of a heat curing initiator, and having a primer coating thickness of 0.05 to 5 μm.