JPH07145352A - Pressure-sensitive adhesive tape its production - Google Patents

Abstract

PURPOSE:To obtain a polystyrene heat-sensitive pressure-sensitive adhesive tape freed from a release agent layer and a release paper by forming a layer of a pressure-sensitive adhesive comprising a specified heat-sensitive pressure- sensitive emulsion adhesive on a polystyrenic film. CONSTITUTION:A layer of a pressure-sensitive adhesive comprising a heat- sensitive pressure-sensitive emulsion adhesive comprising an acrylic polymer (A) of a glass transition temperature of -20 deg.C or below, a tackifier (B) of a softening point of 80-150 deg.C and a solid plasticizer (C) in an (A)/(B)/(C) mixing ratio of 1/(0.5-1.5)/(0.5-1) is formed on a polystyrenic film. As the component A, a polymer prepared by copolymerizing butyl acrylate as the main monomer with 1-10wt.% acrylic acid is particularly desirable, as the component B, a terpene phenol resin, and as the component C, a suspension of dicyclohexyl phthalate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive adhesive tape suitable for sealing a box made of polystyrene, and more specifically to a polystyrene adhesive tape which does not require a release agent layer and release paper on the back surface of the polystyrene adhesive tape. The present invention relates to a heat-sensitive adhesive tape and a manufacturing method thereof.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for transportation and storage of fresh foods and the like by utilizing the excellent heat insulating property of expanded polystyrene. When using styrene foam, the contents are stored in the box body, the opening of the box body is closed with a lid, and the lid is fixed to the box body with an adhesive tape. However, with the recent increase in demand for resource saving and recycling, in the collection of foam styrene boxes, it is often processed with the adhesive tape or label attached, and the collected polystyrene contains the base component of the adhesive tape. As a result, there is a problem in that the strength of the recovered polystyrene is reduced and coloring is caused.

In order to solve such a problem, Japanese Patent Laid-Open No. 3-1
Japanese Patent No. 31677 discloses a polystyrene-based pressure-sensitive adhesive tape characterized in that a curable silicone-based release agent layer is provided on one surface of a substrate made of a polystyrene-based film, and an acrylic pressure-sensitive adhesive layer is provided on the other surface. ing.

Further, in JP-A-5-186745, a release agent layer made of an emulsion type release agent is formed on one surface of a substrate made of a polystyrene film, and an emulsion type release agent layer is formed on the other surface. Form an undercoat layer consisting of an undercoat, and separately coat a solvent-type rubber-based pressure-sensitive adhesive or emulsion-type acrylic-based pressure-sensitive adhesive on release paper and dry it. A method of transferring the agent layer is disclosed.

Further, in JP-A-62-164777, a resource-saving and economically advantageous adhesive sheet composition comprising a polymer and solid plasticizer particles having a volume average particle size of 14 microns or more, A heat-sensitive adhesive composition preferably containing a tackifier is disclosed.

[0006]

However, in the technique disclosed in Japanese Patent Laid-Open No. 3-131677, hexane, heptane, etc. are used as a solvent for the curable release agent, and although the influence on the polystyrene film is small, There is a problem in that the strength of the polystyrene film may be reduced due to the drying conditions when applied to the polystin film, and the number of manufacturing steps is two.

Further, in the technique disclosed in JP-A-5-186745, the number of manufacturing steps is large, and furthermore, the pressure-sensitive adhesive layer is applied to release paper, and after drying, the pressure-sensitive adhesive layer is applied to the undercoat layer on the polystyrene film. Since the transfer method is used, release paper is required, which is not economical in view of the recent increase in resource saving.

Further, in the technique disclosed in JP-A-62-164777, a large amount of solid plasticizer is blended with the polymer,
There are physical problems such as deterioration of transparency, poor appearance, low adhesive strength, etc. Also, for applications using polystyrene film as a base material, it is necessary to give adhesive strength at low temperature (80 to 110 ° C.) heating. Therefore, further improvement is necessary.

[0009]

In order to solve the above problems, the inventors of the present invention have made diligent studies, and as a result, have found that the acrylic polymer (A) having a glass transition temperature of -20 ° C. or less and a softening point of 8 or less.
It consists of a tackifier (B) and a solid plasticizer (C) at 0 ° C to 150 ° C, and the compounding weight ratio of (A) / (B) / (C) is 1 / 0.5 to 1.5 / 0. By providing a pressure-sensitive adhesive layer made of an emulsion-type heat-sensitive pressure-sensitive adhesive of 5-1 on a polystyrene film, a release agent layer and release paper are not required, and good adhesiveness can be obtained by heating during application. The inventors have found that power can be obtained and have reached the present invention.

The present invention will be described in detail below. Examples of the polystyrene film used in the present invention include polystyrene, butadiene-styrene copolymer, styrene-acrylonitrile copolymer, and the like, and films selected from a mixture of polystyrene and these copolymers.
Although both a stretched film and an unstretched film are used as appropriate, a stretched film is more preferably used.

The acrylic polymer (A) used in the present invention may have a glass transition temperature of -20 ° C. or lower, and for example, an alkyl alkylate having an alkyl group with 4 to 12 carbon atoms or a methacrylate is a main monomer. In addition, a small amount of vinyl acetate, acrylonitrile, acrylic acid, methacrylic acid, lower alkyl acrylate, lower methacrylate, styrene, vinylidene chloride, hydroxyethyl acrylate, etc. for adjusting the glass transition temperature, imparting cohesiveness, and preventing the sticking out of the paste. An emulsion-type acrylic polymer obtained by copolymerizing
Those copolymerized by weight% are particularly preferable.

The tackifier (B) used in the present invention must have a softening point of 80 ° C. to 150 ° C. from the viewpoint of exerting an adhesive force by heating (80 to 110 ° C.) during application. , The tackifier (B) has a softening point of 15
If the temperature is higher than 0 ° C, the heating temperature for adhering the adhesiveness at the time of sticking becomes too high, which causes problems such as thermal deformation and coloring of the polystyrene film which is the base material, and softening of the tackifier (B). If the point is less than 80 ° C., the adhesiveness will be developed at a temperature of about 0 ° C. to 40 ° C., so that a release paper and a release agent are required, and there is a problem that the adhesive strength at the time of heating and pasting is low. The softening point of the tackifier (B) is preferably 90 ° C to 140 ° C, more preferably 100 ° C to 130 ° C.
An emulsion type tackifier selected from the range of ° C is used.

The softening point used in the present invention is 80 ° C.
Examples of the tackifier (B) at 150 ° C. include terpene phenol resins such as YS Polyester T-120, T-130, T-145 (all manufactured by Yasuhara Chemical Co., Ltd.), Escrystal A-100, A-120 ( Chromaninden resin such as Nippon Steel Chemical Co., Ltd., Nikanol HP
Xylene resin such as -100 (manufactured by Mitsubishi Gas Chemical Co., Inc.),
Polymerized rosin ester type such as pentaline CJ (manufactured by Rika Hercules Co., Ltd.) and Pencel C (manufactured by Arakawa Chemical Industry Co., Ltd.), super ester A-100, A-115, A-1
Rosin esters such as 25 (all manufactured by Arakawa Chemical Industry Co., Ltd.), Tamanor 135,145 (all manufactured by Arakawa Chemical Industry Co., Ltd.)
Manufactured by YS Polyester T-, from the viewpoint of better adhesive strength.
Polymerized rosin ester such as terpene phenol resin such as 120, T-130, T-145 (all manufactured by Yasuhara Chemical Co., Ltd.), pentaline CJ (manufactured by Rika Hercules Co., Ltd.), Pencel C (manufactured by Arakawa Chemical Co., Ltd.) And more preferably YS Polyester T-120, T-.
Examples thereof include terpene phenolic resins such as 130 (all manufactured by Yasuhara Chemical Co., Ltd.). Further, the tackifier (B) used in the present invention can be used in combination of two or more kinds.

The weight ratio of the tackifier (B) to the acrylic polymer (A) is 0.5-1.
If it is less than 0.5, there is a problem that release paper and a release agent are required because the adhesiveness is developed at a temperature of about 0 ° C. to 40 ° C., and the heat adhesive strength is low. When it is more than 1.5, the time for developing tackiness during heating becomes long,
There is a problem such as low heat adhesive strength, and preferably 0.6 to
1.2, and more preferably 0.7 to 1.1.

From the viewpoint of imparting blocking resistance, the solid plasticizer (C) used in the present invention includes dicyclohexyl phthalate, glycerol tribenzoate, trimethylpropane tribenzoate, pentaerythrite tetrabenzoate and tricitrate. A solid plasticizer selected from cyclohexyl and the like, preferably made of dicyclohexyl phthalate, glycerol tribenzoate, and more preferably dicyclohexyl phthalate, from the viewpoint of exhibiting better blocking resistance, and suspended by a known method. Is used. In addition, the solid plasticizer (C) used in the present invention can be used in combination of two or more kinds.

The blending weight ratio of the above-mentioned solid plasticizer (C) to the acrylic polymer (A) is 0.5-1.
If it is less than 0.5, there is a problem that adhesiveness is developed at a temperature of about 0 ° C. to 40 ° C. and a release paper or a release agent is required, and if it is more than 1.0. There is a problem that the time for developing the tackiness during heating is long, the tackiness is lowered, the transparency is lowered, etc., and preferably 0.6 to
0.9, and more preferably 0.7 to 0.8.

When the heat-sensitive adhesive comprising the above-mentioned three components of the present invention is applied, the heating temperature is preferably 80 ° C. to 110 ° C. and the heating time is preferably 1 to 5 seconds. If the heating temperature is less than 80 ° C., the adhesive strength will be low. If it is not exhibited, and if it is higher than 110 ° C, there is a problem such as thermal deformation and coloring of the polystyrene film which is the base material.
It is preferably 90 ° C to 100 ° C.

(A) / (B) / used in the present invention
(C) The compounding weight ratio of each component is 1 / 0.5 to 1.5 / 0.
The solid content concentration of the emulsion type heat-sensitive adhesive of 5-1 is 50 to 80% by weight, preferably 60 to 70, when the drying rate after coating on the polystyrene film is taken into consideration.
Weight percent is preferred. The coating amount on the polystyrene film is preferably 20 g / m ² or more.

The method for producing the polystyrene pressure-sensitive adhesive tape of the present invention is the above emulsion type while moving the polystyrene film by an appropriate coating method such as the Graavi coating method, the eardactor knife method, the roll coater method, the comma coater method. It is carried out by applying the heat-sensitive adhesive of (1) to one side of a polystyrene film and drying it at a temperature of 80 ° C or lower. When the drying temperature is higher than 80 ° C., there are disadvantages such as poor leveling property, thermal deformation of the polystyrene-based substrate film, and blocking due to development of tackiness, which are not preferable.

The heat-sensitive adhesive tape of the present invention is wound up to be stored as a roll-shaped adhesive tape, and the actual adhesive tape product is supplied by cutting the adhesive tape roll according to the width of the product. .

[0021]

[Working] The polystyrene-based heat-sensitive adhesive tape of the present invention does not require a release agent layer and release paper, and develops adhesiveness by being heated at the time of application and foams the heat-sensitive adhesive tape. It is very economical because it can be recycled without peeling because it is the same material even when used to seal a polystyrene box.

[0022]

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples. In the examples, “%” means weight basis unless otherwise specified. Example 1 (A) Acrylic polymer emulsion Composition: butyl acrylate / acrylic acid = 97/3 (wt%) Glass transition temperature (−53 ° C.) (B) Terpene phenol resin emulsion YS Polyester T-130 (Yasuhara Chemical Co., Ltd. )
The softening point is 130 ° C. (C) Dicyclohexyl phthalate suspension The compounding weight ratio of the above-mentioned components (hereinafter abbreviated as compounding ratio) is
(A) / (B) / (C) = 1/1 / 0.75 (weight ratio)
A solid emulsion having a solid content of 70% by weight is prepared and coated on a polystyrene film at a coating amount of 30 g / m ² and then dried at 70 ° C. to prepare a heat-sensitive adhesive tape having an adhesive layer thickness of 20 μm. Then, it was attached to a SUS plate at a heating temperature of 100 ° C. The adhesive force, back surface peeling force and holding force were evaluated as follows. The evaluation results are shown in Table 3.

Adhesion: 25 mm (width) x 1 on SUS plate
A 00 mm (length) tape was thermocompression bonded under the condition of 100 ° C. × 2 seconds, left at 23 ° C. for 30 minutes, and then a tensile tester (A
G-100A, manufactured by Shimadzu Corporation, was used to measure the adhesive strength by peeling at 180 ° at a pulling rate of 300 mm / min.

Backside peeling force: A roll-shaped unrolled portion having a width of 25 mm was unrolled at a pulling speed of 300 mm / min using a tensile tester (AG-100A, manufactured by Shimadzu Corporation), and the peeling force was measured.

Holding power: A 25 mm × 25 mm tape was heat-pressed to a SUS plate at 100 ° C. for 2 seconds, left at 23 ° C. for 24 hours, and then a weight of 1 kg was hung at 40 ° C. for 2 hours.
The deviation distance after 4 hours or the time until falling was measured using a creep tester (manufactured by Rigaku Kogyo Co., Ltd.).

Examples 2 to 5 and Comparative Examples 1 to 7 Polystyrene heat-sensitive adhesive tapes were produced according to Example 1 and evaluated according to Example 1. Tables 1 and 2 show these compounding types and the compounding ratio of each component. The evaluation result is
It shows in Table 3.

Example 6 The same heat-sensitive adhesive as in Example 1 was used and evaluated in the same manner as in Example 1 except that the heating temperature at the time of attachment was 70 ° C. The evaluation results are shown in Table 3.

Example 7 The same heat-sensitive adhesive as in Example 1 was used and evaluated in the same manner as in Example 1 except that the heating temperature at the time of attachment was 120 ° C. The evaluation results are shown in Table 3.

[0029]

[Table 1] Acrylic polymer (A) Tackifier (B) Solid plasticizer (C) Example 1 BA / AAc = 97/3 terpene phenol resin, softening point: 130 ° C Dicyclo phthalate Tg: -53 ° C YS Polyester T-130 (manufactured by Yasuhara Chemical Co., Ltd.) Hexyl (blending ratio) 1 1 0.75 Example 2 BA / AAc = 97/3 Terpenene phenol resin, softening point: 130 ° C Dicyclophthalate Tg: -53 ° C YS Polyester T-130 (manufactured by Yasuhara Chemical Co., Ltd.) Hexyl (blending ratio) 1 1.2 0.9 Example 3 BA / AAc = 97/3 Terpenic phenol resin, softening point: 130 ° C Dicyclophthalate Tg: -53 ° C YS Polyester T- 130 (manufactured by Yasuhara Chemical Co., Ltd.) Hexyl (blending ratio) 1 0.6 0.6 Example 4 BA / VAc / AAc Polymerized rosin ester resin, softening point: 120 ° C Tribenzoic acid = 85/10/5 Hentalin CJ (Rika Hercules Co., Ltd. ) Ltd.) click Bu Riseroru Tg: -43 ° C. (blending ratio) 1 1.0 0.75 example 5 2-HEA / VAc / AAc polymerization Rojin'e Ether resin, softening point: 120 ° C. phthalate Shi Bu cyclo = 85/10/5 f ° Ntarin CJ (manufactured by Rika Hercules Co.) hexyl Tg: -58 ° C. (blending ratio) 1 1.0 0.75 Abbreviations Description Tg: glass transition temperature BA: Butyl acrylate AAc: Acrylic acid VAc: Vinyl acetate 2-EHA: 2-Ethylhexyl acrylate MMA: Methyl methacrylate

[0030]

[Table 2] Acrylic polymer (A) Tackifier (B) Solid plasticizer (C) Comparative example 1 BA / AAc = 97/3 Terpenic phenol resin, softening point: 130 ° C Dicyclophthalate Tg: -53 ° C YS Polyester T-130 (manufactured by Yasuhara Chemical Co., Ltd.) Hexyl (blending ratio) 1 1.8 0.75 Comparative Example 2 BA / AAc = 97/3 Terpenic phenol resin, softening point: 130 ° C Dicyclophthalate Tg: -53 ° C YS Polyester T-130 (Yasuhara Chemical Co., Ltd.) Hexyl (blending ratio) 1 0.2 0.75 Comparative Example 3 BA / AAc = 97/3 Terpene phenol resin, softening point: 130 ° C Dicyclophthalate Tg: -53 ° C YS Polyester T- 130 (manufactured by Yasuhara Chemical Co., Ltd.) Hexyl (blending ratio) 1 1 0.3 Comparative Example 4 BA / AAc = 97/3 Terpene phenol resin, softening point: 130 ° C. Dicyclo phthalate Tg: -53 ° C. YS Polyester T-130 ( Yasuhara Chemical Co., Ltd.) hexyl (compounding ratio) 1 1 1.3 Comparative example 5 BA / AAc = 97/3 Teruhe ° down phenol tree Softening point: 50 ° C. phthalate Shi Bu cycloalkyl Tg: -53 ° C. YS port Riesuta T-50 (manufactured by Yasuhara Chemical Co.) hexyl (compounding ratio) 1 1 0.75 Comparative Example 6 BA / AAc = 97/3 rosin-modified phenolic resin , Softening point: 180 ° C Dicyclophthalate Tg: -53 ° C Tamanor 351 (manufactured by Arakawa Chemical Industry Co., Ltd.) Hexyl (blending ratio) 1 1 0.75 Comparative Example 7 BA / MMA / AAc Terpenphenol resin, softening point: 130 ° C Dicyclophthalate = 60/37/3 YS Polyester T-130 (Yasuhara Chemical Co., Ltd.) Hexyl Tg: (-10 ° C) (mixing ratio) 1 1 0.75

[0031]

[Table 3] Adhesive physical properties Adhesive strength Backside peeling force Deviation (after 24 hours) (g / 25mm) (g / 25mm) (mm) Example 1 1100 30 0.5 Example 2 980 25 0.5 Example 3 1200 35 3.0 Example 4 900 35 3.0 Example 5 950 35 4.0 Example 6 900 30 (drop in 20 hours) Example 7 1000 30 1.0 Comparative Example 1 400 20 1.0 Comparative Example 2 800 450 (partially peelable) (in 2 hours) Drop) Comparative example 3 1000 250 (partially peelable) 3.0 Comparative example 4 500 10 5.0 Comparative example 5 600 No peeling possible (fall within 1 hour) Comparative example 6 200 10 0 Comparative example 7 500 10 0

[0032]

EFFECT OF THE INVENTION The polystyrene heat-sensitive adhesive tape of the present invention does not require a release agent layer and release paper, and develops adhesiveness by heating at the time of application, and when the box made of expanded polystyrene is sealed. Even if it is used, it is the same material and can be recycled without peeling, which is very economical.

Claims (3)

[Claims] 1. An acrylic polymer (A) having a glass transition temperature of −20 ° C. or lower, a tackifier (B) having a softening point of 80 ° C. to 150 ° C., and a solid plasticizer (C), and (A) /
The blending weight ratio of (B) / (C) is 1 / 0.5 to 1.5 /
A polystyrene-based heat-sensitive adhesive tape, characterized in that a pressure-sensitive adhesive layer made of an emulsion-type heat-sensitive adhesive of 0.5 to 1 is provided on a polystyrene-based film. 2. The heating temperature at the time of sticking is 80 ° C. to 110 ° C.
The heat-sensitive adhesive tape according to claim 1, wherein the temperature is 0 ° C. 3. The emulsion type heat-sensitive adhesive according to claim 1 is applied to one side of a polystyrene film,
A method for producing a polystyrene-based heat-sensitive adhesive tape, characterized in that the adhesive tape according to claim 1 or 2 is obtained by drying at a temperature of not more than ° C.