JPH07278506A - Double-sided heat-sensitive tacky tape - Google Patents

Abstract

PURPOSE:To obtain a tape excellent in blocking resistance without requiring a separator by coating both surfaces of a substrate with a heat-sensitive tacky agent layer containing a specific thermoplastic resin, a tackifier and a solid plasticizer. CONSTITUTION:This tape is obtained by coating both surfaces of a substrate comprising paper, a nonwoven or a woven fabric with a heat-sensitive tacky agent layer containing (A) a thermoplastic resin having >=-5 deg.C (preferably <50 deg.C) glass transition temperature, with the proviso that the glass transition temperature is >=0 deg.C in the case of an ethylene-vinyl acetate copolymer, (B) a tackifier having preferably >=80 deg.C (especially >=100 deg.C) softening temperature and (C) a solid plasticizer preferably coated with an inorganic compound and/or resin fine particles.

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 also called a double-sided adhesive tape or a double-sided adhesive tape, and as shown in FIG. 1, a tape body having an adhesive layer 2 on both sides of a base material 3 and a separator for protecting its adhesiveness. 1 (also called a liner or release liner), or as shown in FIG. 2, it comprises a tape body having an adhesive layer 5 on both sides of a base material 6 and a separator 4 for protecting its adhesiveness. In general, the tape body is often wound in a roll with a separator, and can be processed into various shapes such as a sheet or a flat plate with a suitable size depending on the application. However, the conventional double-sided tape requires a separator in any form.

Here, the separator is necessary to protect the adhesive surface, and is a release paper obtained by subjecting the surface of papers such as high-quality paper and glassine paper to release treatment with silicone resin, release of silicone resin and the like. A plastic film coated with a mold 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 using an ordinary pressure-sensitive adhesive without using 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 and is excellent in blocking resistance.

[0006]

That is, the present invention provides a thermoplastic resin having a glass transition temperature of −5 ° C. or more on both sides of a substrate,
Provided is a double-sided heat-sensitive adhesive tape having a heat-sensitive adhesive layer containing a tackifier and a solid plasticizer.

As shown in FIG. 3, the double-sided heat-sensitive adhesive tape of the present invention comprises a substrate 8 and a heat-sensitive adhesive layer 7 having blocking resistance.

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 having a glass transition temperature of -5 ° C. or more, and a tackifier as a basic skeleton. For example, "Adhesion Handbook" (Twelfth Edition, Showa 55)
, Published by Kobunshi Publishing Co., Ltd.) can be used. Thermoplastic resins are the source of adhesive strength and adhesive strength. Further, since the solid plasticizer is a solid at room temperature, it does not impart plasticity to the resin, and it melts by heating to swell or soften the resin. Acts to express. At this time, when the tackifier is present, the tackiness becomes more remarkable, and the practical properties are improved.

The glass transition temperature of the thermoplastic resin is -5 ° C in order to improve the blocking resistance of the heat-sensitive adhesive layer.
However, in the case of ethylene-vinyl acetate, 0 ° C or higher is preferable. However, if the glass transition temperature is too high, the film-forming property will be deteriorated.
Less than is preferred. Further, when the thermoplastic resins are mixed and used, the value calculated from the glass transition temperature of each thermoplastic resin assuming that the additivity is established according to the weight ratio, or actually performing thermal analysis of the mixture At least one of the values should fall within the above range.

In order to further improve the blocking resistance of the heat-sensitive adhesive layer, 1) use of a solid plasticizer having a high melting point in the composition of the heat-sensitive adhesive, 2) surface treatment of the solid plasticizer, 3) Use of a tackifier having a high softening temperature, 4) addition of a third component, etc. may be performed.

As for "1) Use of solid plasticizer having high melting point", it is preferable to use solid plasticizer having a melting point of 50 ° C or higher, more preferably 60 ° C or higher. When the solid plasticizers are mixed and used, the value calculated as the additivity is established depending on the weight ratio from the melting point of each solid plasticizer,
Alternatively, at least one of the values obtained by actually performing thermal analysis of the mixture may fall within the above range.

Regarding "2) Surface treatment of solid plasticizer", it is preferable to coat the surface of the solid plasticizer with an inorganic compound and / or resin fine particles. Even if the solid plasticizer has a melting point or less, it melts to some extent to give plasticity to the resin depending on conditions such as storage temperature, so that there is a problem in blocking resistance. However, it is considered that by coating the surface of the solid plasticizer with the inorganic compound and / or the resin fine particles, the melting of the solid plasticizer is suppressed and the blocking resistance is improved.

Examples of the inorganic compound include oxides, hydrates, inorganic acid salts, organic acid salts, ammonium salts, metal compounds, and special compounds such as colloids. It may be appropriately selected depending on the compatibility with the thermoplastic resin, tackifier or solid plasticizer used in the heat-sensitive adhesive, cost, and the like. More specifically, oxides, hydroxides, oxyhydroxides, nitrates, carbonates, phosphates, sulfates, oxalates, acetates, tartrates and citrates are used.

Specific examples of inorganic compounds include magnesium oxide, aluminum oxide, titanium oxide, barium oxide, titanium barium oxide, aluminum barium oxide,
Examples thereof include oxides such as magnesium aluminum oxide and aluminum silicon oxide, magnesium hydroxide, aluminum hydroxide, barium hydroxide, talc, calcium carbonate, barium sulfate.

As the colloid, colloids of inorganic compounds and organic compounds can be used.
Examples thereof include molecular colloids such as proteins or elastic rubbers, micellar colloids formed from soaps, particle colloids such as oxide sols and metal sols, and particle colloids are particularly preferable. There are various types of particle colloids depending on the combination of the dispersoid and the dispersion state of the dispersion medium, and examples of the oxide sol include colloidal silica, alumina sol, antimony oxide sol, and zirconia sol. Examples of the metal sol include gold sol and selenium sol. Further, smectite and the like, which are fine clay minerals and become a sol when dispersed in water or the like, can be mentioned.

As the resin fine particles, those having a glass transition temperature of 50 ° C. or more and an average particle diameter of 10 μm or less are preferable, and they are used as a thermoplastic resin, a tackifier or a solid plasticizer used in a heat-sensitive adhesive. It may be appropriately selected depending on the compatibility or cost. As a use form, it can be used in the form of powder or emulsion. When resin fine particles are used, those having a substantially spherical shape are preferable.
Examples of the resin fine particles include, but are not limited to, styrene polymer powder, ethylene polymer powder, methyl methacrylate polymer powder, and methyl methacrylate-styrene copolymer powder. Further, the resin fine particles may be added after being dispersed in a solvent, or may be added as it is. A known solvent can be appropriately used as the dispersion solvent, and the dispersion solvent is not limited to the organic solvent, and may be an inorganic solvent or, of course, water.

As a method of coating the surface of the solid plasticizer with an inorganic compound and / or resin fine particles,
(1) A method of softening or melting the surface of the solid plasticizer by heat, (2) a method of using a binder, (3) a method of mechanical impact means, and the like, but not limited to these. Absent. The above method and apparatus are specifically described in "Granulation Handbook" (1st edition, 1991, published by Ohmsha).

As the method (1), a fluidized coating device, a tumbling coating device or a pan coating device is used to heat the entire device by the heat of a heating medium (water, etc.) A method of coating the inorganic compound and / or resin fine particles by softening or melting the resin, or by directly softening or melting the surface of the plasticizer with hot air or the like. Examples of the method (2) include a method of coating a solid plasticizer with an inorganic compound by supplying a binder into the apparatus using a fluidized coating apparatus, a tumbling coating apparatus or a pan coating apparatus. Any binder can be used as long as it can bond the solid plasticizer with the inorganic compound and / or the resin fine particles, and for example, polyvinyl alcohol, gelatin, gum arabic, dextrin, natural rubber, sodium alginate and the like can be used. Examples of the method (3) include an impact method in a high-speed air stream, and the surface of a solid plasticizer can be directly coated with an inorganic compound and / or resin fine particles.

When the surface of the solid plasticizer is coated with an aqueous dispersion such as a colloid, (1) after mixing and dispersing the solid plasticizer in the aqueous dispersion such as a colloid, heating and / or depressurizing the dispersion medium. Complete or partial evaporation, (2)
After evaporating the dispersion medium in which the aqueous dispersion such as colloid is dispersed,
The method may be, but not limited to, the method of coating in the same manner as in the case of the inorganic compound and / or the resin fine particles.

"3) Use of tackifier having high softening temperature"
With respect to, it is preferable to use a tackifier having a softening temperature of 80 ° C. or higher, more preferably 100 ° C. or higher. Regarding “4) addition of third component”, an inorganic compound (preferably colloid) and / or resin fine particles are added to the heat-sensitive adhesive.
It is appropriately selected and contained depending on the compatibility with the thermoplastic resin used in the heat-sensitive adhesive, the tackifier and the solid plasticizer, the cost or the like. As the inorganic compound and / or resin fine particles, those described in the above “2) Surface treatment of solid plasticizer” can be used, but particles having a particle size of 10 μm or less are particularly preferable. Hard particles having a glass transition temperature of 50 ° C. or higher are preferred.

Examples of the solid plasticizer in the composition of the heat-sensitive adhesive used in the present invention include diphenyl phthalate, dihexyl phthalate, dicyclohexyl phthalate, dihydroabietyl phthalate, dimethyl isophthalate, sucrose benzoate, and diphenyl phthalate. Ethylene glycol benzoate, trimethylolethane tribenzoate, tribenzoic acid glyceride, pentaerythritol tetrabenzoate, sucrose octaacetate, tricyclohexyl citrate, N-cyclohexyl-p-toluenesulfonamide and the like, but phthalic acid Dicyclohexyl is preferred.

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.

Further, the tackifier for improving the tack performance of the heat-sensitive adhesive is 5 to 10 with respect to 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 solid plasticizer, the thermoplastic resin or the tackifier may 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 are 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, organic substances such as paraffin, natural wax, synthetic wax, natural oils and fats can be added to the heat-sensitive adhesive. 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 the substrate as an aqueous emulsion or an organic solvent solution, but it is preferably coated as an aqueous emulsion in consideration of handling of the tape after coating and drying.

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.

[0030]

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.

[Embodiment 1] Fluid coating apparatus (Fuji Paudal Co., Ltd. Numalmerizer NQ-LABO)
In addition, 300 parts of diphenyl phthalate (melting point 69 ℃) and titanium oxide
30 parts were charged and the surface of diphenyl phthalate was coated with titanium oxide by hot air. As a result of observing the coating state of diphenyl phthalate coated with titanium oxide with a scanning electron microscope, it was confirmed that the coating was performed. Then, with the formulation shown in Table 1, 5
Mixing and stirring were performed in a mixer for a minute to prepare a heat-sensitive adhesive. Example 2 With the same apparatus as in Example 1, 300 parts of dicyclohexyl phthalate (melting point: 65 ° C.) was coated with 30 parts of magnesium oxide by hot air. It was confirmed that it was coated with magnesium oxide as in Example 1. Then, with the formulation shown in Table 1, a heat-sensitive adhesive was prepared in the same manner as in Example 1.

Example 3 A device similar to that of Example 1 was charged with 300 parts of dicyclohexyl phthalate and 30 parts of titanium oxide, and a solution of 3% acrylic polymer in n-butyl alcohol was used as a binder to prepare dicyclohexyl phthalate. The surface was coated with titanium oxide. The coating with titanium oxide was confirmed as in Example 1. Then, with the formulation shown in Table 1, a heat-sensitive adhesive was prepared in the same manner as in Example 1. [Example 4] 300 parts of diphenyl phthalate and 30 parts of aluminum oxide were charged into a rolling coating device (high-speed mixer LFS-1 manufactured by Fukae Kogyo Co., Ltd.), and the surface of diphenyl phthalate was coated with aluminum oxide by heating. . The coating with aluminum oxide was confirmed as in Example 1. Then, with the formulation shown in Table 1, a heat-sensitive adhesive was prepared in the same manner as in Example 1.

[Embodiment 5] 300 parts of dicyclohexyl phthalate and 30 parts of titanium oxide were added to a surface modifying apparatus for powder (hybridization system NHS-O manufactured by Nara Machinery Co., Ltd.) using a high-speed air impact method. Was charged, and the surface of dicyclohexyl phthalate was coated with titanium oxide by mechanical impact. The coating with titanium oxide was confirmed as in Example 1. Then, with the formulation shown in Table 1, a heat-sensitive adhesive was prepared in the same manner as in Example 1. [Example 6] 150 parts of colloidal silica (solid content 20%) and 300 parts of dicyclohexyl phthalate were mixed and dried in a mixer, then placed in a glass beaker according to the formulation shown in Table 1 and mixed by a mixer. , An adhesive was prepared. It was confirmed in the same manner as in Example 1 that dicyclohexyl phthalate was coated with colloidal silica. Then, Table 1
A heat-sensitive adhesive was prepared in the same manner as in Example 1 with the formulation shown in.

[Example 7] Alumina sol (solid content 20%) 1
50 parts and 300 parts of diphenyl phthalate were mixed and dried in a mixer, then placed in a glass beaker having the composition shown in Table 1 and mixed by a mixer to prepare an adhesive. The coating of diphenyl phthalate with alumina sol was confirmed as in Example 1. Then, with the formulation shown in Table 1, a heat-sensitive adhesive was prepared in the same manner as in Example 1. [Example 8] Using the same apparatus as in Example 1, 150 parts of zirconia sol (solid content 20%) and 300 parts of dicyclohexyl phthalate were charged, and the surface of dicyclohexyl phthalate was coated with zirconia sol by hot air. The coating of dicyclohexyl phthalate with zirconia sol was confirmed as in Example 1. Then, with the formulation shown in Table 1, a heat-sensitive adhesive was prepared in the same manner as in Example 1.

Example 9 In the same apparatus as in Example 4, 150 parts of colloidal silica (solid content 20%) and 300 parts of dicyclohexyl phthalate were charged, and a 3% acrylic polymer solution in n-butyl alcohol was used as a binder. Used to coat dicyclohexyl phthalate surface with colloidal silica. It was confirmed in the same manner as in Example 1 that dicyclohexyl phthalate was coated with colloidal silica. Then, using the formulation shown in Table 1, Example 1
A heat-sensitive adhesive was prepared in the same manner as in. [Example 10] A heat-sensitive adhesive was prepared in the same manner as in Example 9 except that half of the colloidal silica (75 parts) was replaced with alumina sol (solid content 20%). As in Example 1, it was confirmed that dicyclohexyl phthalate was coated with colloidal silica and alumina sol.
Then, with the formulation shown in Table 1, a heat-sensitive adhesive was prepared in the same manner as in Example 1.

Example 11 30 parts of powder obtained by drying colloidal silica in a dryer was coated on the surface of 300 parts of dicyclohexyl phthalate by heating using the same apparatus as in Example 4. It was confirmed in the same manner as in Example 1 that dicyclohexyl phthalate was coated with colloidal silica. Then, with the formulation shown in Table 1,
A heat-sensitive adhesive was prepared in the same manner as in Example 1. Example 12 Using the same apparatus as in Example 1, 300 parts of dicyclohexyl phthalate and methyl methacrylate-styrene copolymer powder (particle size 0.2 to 0.5 μm, Tg = 128 ° C., spherical powder manufactured by Soken Chemical Industry Co., Ltd.) ) 30 parts, and the surface of dicyclohexyl phthalate was coated with methyl methacrylate-styrene copolymer powder by hot air. It was confirmed in the same manner as in Example 1 that the methyl methacrylate-styrene copolymer powder was coated with dicyclohexyl phthalate. Then, with the formulation shown in Table 1, a heat-sensitive adhesive was prepared in the same manner as in Example 1.

[Embodiment 13] An apparatus similar to that of Embodiment 4 is used.
150 parts diphenyl phthalate, dicyclohexyl phthalate
150 parts and 30 parts of methyl methacrylate-styrene copolymer powder (particle size 0.4 μm, Tg = 95 ° C., spherical powder manufactured by Soken Chemical Industry Co., Ltd.) were charged, and methacryl was formed on the surface of diphenyl phthalate and dicyclohexyl phthalate with hot air. Coated with methyl acid-styrene copolymer powder. It was confirmed in the same manner as in Example 1 that the methyl methacrylate-styrene copolymer powder was coated with diphenyl phthalate and dicyclohexyl phthalate. Then
A heat-sensitive adhesive was prepared in the same manner as in Example 1 with the formulation shown in Table 1. Example 14 Using the same apparatus as in Example 5, 300 parts of diphenyl phthalate and methyl methacrylate-styrene copolymer powder (particle size 0.2 to 0.5 μm, Tg = 128 ° C., Soken Chemical Industry Co., Ltd.)
30 parts of spherical powder) was charged and the surface of diphenyl phthalate was coated with a methyl methacrylate-styrene copolymer powder by mechanical impact. It was confirmed in the same manner as in Example 1 that the methyl methacrylate-styrene copolymer powder was coated with diphenyl phthalate. Then, with the formulation shown in Table 1, a heat-sensitive adhesive was prepared in the same manner as in Example 1.

[Examples 15 to 22] The compositions shown in Table 1 were mixed by a mixer to prepare heat-sensitive adhesives. In Example 15, half of the colloidal silica (75 parts) was added and mixed, and then half of the colloidal silica (75 parts) was added and mixed. Example 2
No. 0, methyl methacrylate-styrene copolymer powder (particle size 0.2 to 0.5 μm, Tg = 128 ° C., Soken Chemical Industry Co., Ltd.)
Half of the spherical powder) (15 parts) was added and mixed, and then half of the methyl methacrylate-styrene copolymer powder (15 parts) was added (15 parts).
Part) was added and mixed.

Comparative Example 1 300 parts of dicyclohexyl phthalate and 30 parts of styrene polymer powder (particle size 15 to 40 μm, Tg = 105 ° C., spherical powder manufactured by Soken Chemical Industry Co., Ltd.) were placed in the same apparatus as in Example 1. Then, the surface of dicyclohexyl phthalate was coated with styrene polymer powder by hot air. The coating of dicyclohexyl phthalate with styrene polymer powder was confirmed as in Example 1. Then, with the formulation shown in Table 1, a heat-sensitive adhesive was prepared in the same manner as in Example 1.

Comparative Example 2 300 parts of diphenyl phthalate and styrene polymer powder (particle size 15
~ 40 μm, Tg = 105 ° C, 30 parts of spherical powder made by Soken Chemical Industry Co., Ltd.) was added, and 3% acrylic polymer n was used as a binder.
-A styrene polymer powder was coated on the surface of diphenyl phthalate using a butyl alcohol solution. It was confirmed in the same manner as in Example 1 that the styrene polymer powder was coated with diphenyl phthalate. Then
A heat-sensitive adhesive was prepared in the same manner as in Example 1 with the formulation shown in Table 1. [Comparative Examples 3 to 7] With the formulations shown in Table 1, heat-sensitive adhesives were prepared in the same manner as in Example 1.

The heat-sensitive adhesives obtained in Examples and Comparative Examples were coated on 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 the other. The surface was coated and dried in the same manner to obtain a double-sided heat-sensitive adhesive tape. No tackiness could be confirmed in the dried state. Table 1 shows the results of the evaluation of the adhesive strength, the holding power and the blocking resistance of the double-sided heat-sensitive adhesive tape. The evaluation was performed by the following method.

Adhesiveness: The double-sided heat-sensitive adhesive tapes of Examples and Comparative Examples were heated at 120 ° C. for 25 seconds to develop the adhesiveness, and then rapidly adhered to a stainless steel plate, and then JI
According to S K-6848, measure the adhesive strength by peeling 180 degrees,
It was judged according to the following criteria. However, the glued part was 100 mm. In addition, when the tackiness was developed by heating, both surfaces have tackiness, and therefore, the surface not adhered to the stainless steel plate was adhered with a high-quality paper to perform the measurement. ◎ ・ ・ ・ ・ ・ ・ 1000g / 25mm or more ○ ・ ・ ・ ・ ・ ・ 800g / 25mm or more, less than 1000g / 25mm × ・ ・ ・ ・ ・ ・ less than 800g / 25mm

Holding power: The double-sided heat-sensitive adhesive tapes of Examples and Comparative Examples were heated to develop adhesiveness, and then rapidly adhered to a stainless steel plate, and a constant amount of 500 g was applied according to JIS K-6848. Apply load and perform creep test,
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 tapes of Examples and Comparative Examples were cut into a certain size without heating and laminated 10 sheets. A load of 500 g / cm ² was applied to these, and they were stored in an atmosphere of 50 ° C. for 1 hour, then peeled off, 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)

[0045]

[Table 1]

[0046]

[Table 2]

[0047]

[Table 3]

* 1 Coated with an inorganic compound or resin fine particles * 2 Solid content * 3 Softening temperature 150 ° C, manufactured by Arakawa Chemical Industry Co., Ltd. * 4 Styrene-butadiene copolymer * 5 Ethylene-vinyl acetate copolymer * 6 Particle size 0.2-0.5 μm, Tg = 128 ° C, manufactured by Soken Chemical Co., Ltd. * 7 Particle size 0.4 μm, Tg = 95 ° C, manufactured by Soken Chemical Co., Ltd. * 8 Particle size 15-40 μm, Tg = 105 ° C, Soken Chemical Co., Ltd. * 9 Tg = 100 ° C or higher, thermal decomposition temperature 300 ° C, NV = 44%, Mitsui Toatsu Chemical Co., Ltd. * 10 Tg = 100 ° C or higher, thermal decomposition temperature 295 ° C, NV = 35 %, Manufactured by Mitsui Toatsu Chemicals, Inc. * 11 Tg = 2 ° C, NV = 46%, manufactured by Johnson Polymer Co., Ltd. * 12 Tg = 6 ° C, NV = 49%, manufactured by Nippon Zeon Co., Ltd.

[0049]

EFFECTS OF THE INVENTION According to the present invention, as compared with the conventional double-sided adhesive tape or double-sided adhesive tape, a separator is not required, and the adhesiveness is maintained for a while even after the heating source is removed after the adhesiveness is developed. Adhesive strength, holding power, and blocking resistance satisfy practical properties, and in particular, a double-sided heat-sensitive adhesive tape having excellent blocking resistance has been obtained. As a double-sided tape that does not require a separator, and as a sheet or film, the industrial significance of being able to pursue economic benefits with resource saving is:
It is extremely large.

[0050]

[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
... Substrate 7 ... Thermosensitive adhesive layer 8 with blocking resistance
…Base material

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location C09J 7/02 JKE JKK JKP (72) Inventor Makoto Kameyama 2-3-3 Kyobashi, Chuo-ku, Tokyo Toyo Inki Manufacturing Co., Ltd. (72) Inventor Akira Kikuchi 2-33 Kyobashi, Chuo-ku, Tokyo Toyo Inki Manufacturing Co., Ltd.

Claims (10)

[Claims] 1. A double-sided heat-sensitive adhesive characterized in that it has a heat-sensitive adhesive layer containing a thermoplastic resin having a glass transition temperature of −5 ° C. or higher, a tackifier and a solid plasticizer on both sides of a substrate. tape. 2. The double-sided heat-sensitive adhesive tape according to claim 1, wherein the glass transition temperature of the thermoplastic resin is less than 50 ° C. 3. A glass transition temperature of 0 as a thermoplastic resin.
The double-sided heat-sensitive adhesive tape according to claim 1 or 2, wherein an ethylene-vinyl acetate copolymer having a temperature of ℃ or more is used. 4. The double-sided heat-sensitive adhesive tape according to claim 1, wherein a styrene-butadiene copolymer is used as the thermoplastic resin. 5. The double-sided heat-sensitive adhesive tape according to claim 1, wherein an acrylic polymer is used as the thermoplastic resin. 6. The double-sided heat-sensitive adhesive tape according to claim 1, wherein the surface of the solid plasticizer is coated with an inorganic compound. 7. The double-sided heat-sensitive adhesive tape according to claim 6, wherein the inorganic compound is a colloid. 8. The surface of the solid plasticizer has a glass transition temperature of 50.
7. The double-sided heat-sensitive adhesive tape according to claim 1, wherein the double-sided heat-sensitive adhesive tape is coated with resin fine particles having a temperature of not less than 0 ° C. and an average particle diameter of not more than 10 μm. 9. The double-sided heat-sensitive adhesive tape according to claim 1, wherein the heat-sensitive adhesive layer further contains a colloid. 10. The double-sided heat-sensitive material according to claim 1, wherein the heat-sensitive adhesive layer further contains fine resin particles having a glass transition temperature of 50 ° C. or more and an average particle diameter of 10 μm or less. Adhesive tape.