JPH07258616A - Double-face heat-sensitive adhesive tape - Google Patents

Abstract

PURPOSE:To obtain the subject tape needing no separator, excellent in tack sustainability, adhesive force, tack holding ability and blocking resistance by coating both sides of a base material with a heat-sensitive adhesive comprising a solid plasticizer, thermoplastic resin and tackifier. CONSTITUTION:This tape is obtained by coating both sides of a base material such as a paper, nonwoven fabric or film with a heat-sensitive adhesive comprising (A) 100 pts.wt. of a solid plasticizer (pref. dicyclohexyl phthalate), (B) pref. 30-140 pts.wt. of a thermoplastic resin (e.g. acrylic ester) and (C) pref. 10-50 pts.wt. of a tackifier (e.g. terpene resin) It is preferable that the heat-sensitive adhesive be applied in the form of an aqueous emulsion from the standpoint of its coating and the handling of the tape after dried.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is non-tacky at room temperature but develops tackiness upon heating, and
The present invention relates to a double-sided heat-sensitive adhesive tape which retains its tackiness for a while even after removing the heating source.

[0002]

2. Description of the Related Art A conventional double-sided tape is called a double-sided adhesive tape or a double-sided adhesive tape. As shown in FIG. 1, a tape body having an adhesive layer 2 on both sides of a base material 3 and its adhesiveness is protected. It is composed of a sheet of separator 1 (also called a liner or a release liner), or a tape body having an adhesive layer 5 on both sides of a base material 6 as shown in FIG. 2 and two separators 4 for protecting its adhesiveness. . In general, the tape body is often wound in a roll shape together with the separator, and it can be processed into various forms such as a flat sheet shape such as a sheet or film having an appropriate size depending on the application. But,
Conventional double-sided tapes require a separator in any form.

Here, the separator is necessary to protect the surface of the pressure-sensitive adhesive layer, such as release paper obtained by releasing the surface of paper such as high-quality paper and glassine paper with silicone resin, silicone resin, etc. A plastic film coated with a release agent or a plastic film alone is usually used. However, the separator peeled off from the main body when using the double-sided adhesive tape or the double-sided adhesive tape has a problem in disposal as industrial waste, which has been taken up in recent environmental problems.

In order to solve this problem, a type without a separator has been devised, but its adhesive performance is poor and its use is limited to special purposes. Further, the hot-melt adhesive is used in the form of a double-sided tape and is used, for example, for lifting the hem of trousers, but there is a problem in that the workable time is short and the workability is poor.

[0005]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a double-sided heat-sensitive adhesive tape which does not require a separator.

[0006]

That is, the present invention provides a double-sided heat-sensitive adhesive tape having a heat-sensitive adhesive layer containing a solid plasticizer, a thermoplastic resin and a tackifier on both sides of a substrate. The double-sided heat-sensitive adhesive tape of the present invention is shown in FIG.
As shown in FIG. 3, it is composed of a base material 8 and a heat-sensitive adhesive layer 7.

As the substrate, paper, non-woven fabric, woven fabric, film, foam or the like which has been used as a substrate for conventional double-sided adhesive tape or double-sided adhesive tape can be used. Examples of the paper include Japanese paper, high-quality paper, glassine paper and the like, and examples of the non-woven fabric include non-woven fabric such as rayon, polyester and polypropylene. Examples of the woven fabric include woven fabrics of natural fibers or synthetic fibers such as cotton cloth, suf, and vinylon, and examples of the film include films of polyester (especially polyethylene terephthalate), polyvinyl chloride, polypropylene, acetate, cellophane and the like. . Examples of the foam include polyurethane, polyethylene, butyl rubber, chloroprene, vinyl chloride, and acrylic rubber.

The heat-sensitive adhesive has a solid skeleton, a thermoplastic resin and a tackifier as a basic skeleton, and is described in, for example, "Adhesion Handbook" (12th edition, 1980, published by Kobunshi Kogyokai). You can use what you have. Thermoplastic resins are the source of adhesive strength and adhesive strength. Further, the solid plasticizer does not give plasticity to the resin because it is solid at room temperature, and melts by heating to swell or soften the resin,
It acts to develop tackiness by heating a non-tacky tackiness agent at room temperature. At this time, when the tackifier is present, the tackiness becomes more remarkable, and the practical properties are improved.

Examples of the solid plasticizers include diphenyl phthalate, dihexyl phthalate, dicyclohexyl phthalate, dihydroabietyl phthalate, dimethyl isophthalate, sucrose benzoate, ethylene glycol dibenzoate, trimethylolethane tribenzoate, and trimethyl triethane. Benzoic acid glyceride, tetrabenzoic acid pentaerythritol, sucrose octaacetate, tricyclohexyl citrate, N-cyclohexyl
Examples thereof include -p-toluenesulfonamide, but dicyclohexyl phthalate is preferable.

The thermoplastic resin is preferably used in a solid content ratio of 20 to 200 parts by weight, more preferably 30 to 140 parts by weight, based on 100 parts by weight of the solid plasticizer. Examples of the thermoplastic resin include acrylic acid ester, styrene-acrylic acid ester, styrene-butadiene, ethylene-vinyl acetate, vinyl acetate, vinyl acetate-acrylic acid ester,
Examples thereof include polymers such as ethylene-vinyl chloride, ethylene-acrylic acid ester, ethylene-acrylic acid, butadiene, urethane, styrene-isoprene, and acrylonitrile-butadiene.

The tackifier for improving the tack performance of the heat-sensitive adhesive is 5 to 10 parts by weight per 100 parts by weight of the solid plasticizer.
It is preferably used in a solid content ratio of 0 part by weight, more preferably 10 to 50 parts by weight. Examples of the tackifier include terpene resin, aliphatic petroleum resin, aromatic petroleum resin, coumarone-
Examples thereof include indene resin, styrene resin, phenol resin, terpene-phenol resin, and rosin derivative (rosin, polymerized rosin, hydrogenated rosin and their glycerin, esters with pentaerythritol, resin acid dimer, etc.).

The above-mentioned solid plasticizer, thermoplastic resin or tackifier can be used alone or as a mixture of two or more kinds. That is, the solid plasticizer includes dicyclohexyl phthalate and diphenyl phthalate, dicyclohexyl phthalate and dihexyl phthalate, dicyclohexyl phthalate and dihydroabietyl phthalate,
Dicyclohexyl phthalate and dimethyl isophthalate, dicyclohexyl phthalate and sucrose benzoate, dicyclohexyl phthalate and ethylene glycol dibenzoate, dicyclohexyl phthalate and trimethylolethane tribenzoate, dicyclohexyl phthalate and tribenzoic acid glyceride, dicyclohexyl phthalate and Pentaerythritol tetrabenzoate, dicyclohexyl phthalate and sucrose octaacetate, dicyclohexyl phthalate and tricyclohexyl citrate, dicyclohexyl phthalate and N-cyclohexyl-p-toluenesulfonamide, etc. or dicyclohexyl phthalate, diphenyl phthalate It is also possible to use a mixture of three kinds or more with and dihexyl phthalate and the like.

The tackifiers include terpene resins and aliphatic petroleum resins, aromatic petroleum resins and coumarone.
Indene resin, styrene resin and phenol resin,
Terpene-phenol resin and rosin derivative, terpene resin and rosin derivative, aliphatic petroleum resin and rosin derivative, aromatic petroleum resin and rosin derivative, coumarone-indene resin and rosin derivative, styrene resin and rosin derivative, phenol resin and It is also possible to use a mixture of two kinds with a rosin derivative or the like, or three kinds or more with a rosin derivative, an aliphatic petroleum resin, an aromatic petroleum resin and the like.

Further, the thermoplastic resin includes acrylic acid ester and styrene-acrylic acid ester, styrene-butadiene and ethylene-vinyl acetate, vinyl acetate and vinyl acetate-acrylic acid ester, ethylene-vinyl chloride and ethylene-acrylic acid ester, Ethylene
Acrylic acid and butadiene, urethane and styrene-isoprene, styrene-butadiene and acrylic acid ester, styrene-butadiene and styrene-acrylic acid ester, styrene-butadiene and vinyl acetate, styrene-butadiene and vinyl acetate-acrylic acid ester, styrene-butadiene And ethylene-vinyl chloride, styrene-butadiene and ethylene-acrylic acid esters, styrene-butadiene and ethylene-acrylic acid, styrene-butadiene and butadiene, styrene-butadiene and urethane, styrene-
2 with butadiene and styrene-isoprene, styrene-butadiene and acrylonitrile-butadiene, etc.
It is also possible to use three kinds or a mixture of three or more kinds such as styrene-acrylic acid ester, styrene-butadiene and ethylene-vinyl acetate.

In addition to the above, a filler and the like can be added to the heat-sensitive adhesive. Examples of the filler and the like include inorganic substances such as titanium oxide, alumina, kaolin, talc, colloidal silica, and alumina sol, and paraffin,
Examples thereof include organic substances such as natural wax, synthetic wax, natural oil and fat, and resin powder. Further, a solvent, a liquid plasticizer, etc. may be added for the purpose of improving the film-forming property of the coating film. Further, if necessary, a dispersant, a defoaming agent, a thickener, etc. can be used. The heat-sensitive adhesive can be coated on a substrate as an aqueous emulsion or an organic solvent solution, but when the handling of the tape after coating and drying is taken into consideration,
It is preferably applied as an aqueous emulsion.

The double-sided heat-sensitive adhesive tape of the present invention is generally coated with a heat-sensitive adhesive on both sides of the substrate (after being dried as an aqueous emulsion, it is also coated as an organic solvent solution). When processed, it is dried and loses its tackiness), and is often wound into a roll, but depending on the application, it is processed into various forms such as a flat sheet or sheet of a suitable size. It is possible. Unlike the conventional double-sided adhesive tape or double-sided adhesive tape, the double-sided heat-sensitive adhesive tape of the present invention does not require a separator even when processed into any form.

[0017]

EXAMPLES The present invention will be specifically described below with reference to examples. However, the scope of the present invention is not limited to the following examples. In the examples, “part” means “part by weight”,
% Represents% by weight. [Examples 1 to 10] With the formulation shown in Table 1, first, a solid plasticizer, a maleic acid-based resin solution and water were put into a ball mill and pulverized for 24 hours, and then a thermoplastic resin emulsion, a tackifier emulsion and additives were added. Was added and mixed and stirred in a mixer for 5 minutes to prepare a heat-sensitive adhesive.

The heat-sensitive adhesive obtained was applied to one side of a high-quality paper at a coating amount of 20 g / m ² , dried at 45 ° C. for 30 seconds, and then applied to the other side in the same manner. After working and drying, a double-sided heat-sensitive adhesive tape was obtained. No tackiness could be confirmed in the dried state. About double-sided heat-sensitive adhesive tape, adhesive strength,
Table 1 shows the results of evaluation of holding power and blocking resistance. The evaluation was performed by the following method.

Adhesive force; double-sided heat-sensitive adhesive tape
After heating at 120 ° C for 25 seconds to develop tackiness, it was quickly attached to a stainless steel plate, and the adhesive strength was measured by peeling 180 degrees according to JIS K-6848, and the adhesive strength was determined according to the following criteria.
However, the glued part was 100 mm. Further, since the double-sided heat-sensitive adhesive tape has adhesiveness on both sides when the adhesiveness is developed by heating, it was measured by attaching a high-quality paper to the surface not attached to the stainless steel plate. . ◎ ・ ・ ・ ・ ・ ・ 1000g / 25mm or more ○ ・ ・ ・ ・ ・ ・ 800g / 25mm or more, less than 1000g / 25mm × ・ ・ ・ ・ ・ ・ less than 800g / 25mm

Holding power: A double-sided heat-sensitive adhesive tape is immediately attached to a stainless steel plate after the adhesiveness is developed by heating, and a creep test is performed according to JIS K-6848 by applying a constant load of 500 g. It was judged according to the following criteria. However, the gluing part was 25 mm. ◎ ・ ・ 2000sec or more ○ ・ ・ ・ ・ ・ ・ 1000sec or more, less than 2000sec × ・ ・ ・ ・ ・ ・ less than 1000sec

Blocking resistance: The double-sided heat-sensitive adhesive tape was cut into a certain size without heating, and 10 sheets were stacked. A load of 500 g / cm ² was applied to these, and they were peeled off after storing at 25 ° C. for 1 hour, and judged according to the following criteria. 5: No peeling resistance. 4--A slight noise is heard when peeling. 3 ・ ・ A continuous sound is heard when peeling. 2 ・ ・ Pull fiber of paper at the time of peeling. 1 ... · There is breakage of the substrate due to blocking. 0 ... ・ Completely adhere. (Peeling impossible)

[0022]

[Table 1] * 1 Solid content ratio * 2 Styrene-butadiene copolymer * 3 Ethylene-vinyl acetate copolymer

[0023]

According to the present invention, unlike the conventional double-sided pressure-sensitive adhesive tape or double-sided adhesive tape, a separator is not required, and after the pressure-sensitive adhesiveness is exhibited, the pressure-sensitive adhesiveness is maintained for a while even if the heating source is removed, and the adhesive strength, It has become possible to obtain a double-sided heat-sensitive adhesive tape that can satisfy practical properties in terms of holding power and blocking resistance. The industrial significance of being able to pursue economic benefits by resource saving as a double-sided tape that does not require a separator, and as a sheet or film, is extremely great.

[0024]

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a conventional double-sided pressure-sensitive adhesive tape having one separator.

FIG. 2 is a cross-sectional view of a conventional double-sided adhesive tape having two separators.

FIG. 3 is a sectional view of the double-sided heat-sensitive adhesive tape of the present invention.

[Explanation of symbols]

1 Separator 2 Adhesive layer 3
Base material 4 Separator 5 Adhesive layer 6
Base material 7 Thermosensitive adhesive layer 8 Base material

Front page continuation (72) Inventor Makoto Kameyama 2-3-13 Kyobashi, Chuo-ku, Tokyo Toyo Inki Manufacturing Co., Ltd. (72) Akira Kikuchi 2-3-13 Kyobashi, Chuo-ku, Tokyo Toyo Inki Manufacturing Co., Ltd.

Claims (1)

[Claims] 1. A double-sided heat-sensitive adhesive tape having a heat-sensitive adhesive layer containing a solid plasticizer, a thermoplastic resin and a tackifier on both sides of a substrate.