KR101616142B1 - Adhesive film - Google Patents

Abstract

INDUSTRIAL APPLICABILITY The pressure-sensitive adhesive film of the present invention comprises a substrate comprising a vinyl chloride resin composition and an adhesive base layer formed on at least one side of the substrate, wherein the pressure-sensitive adhesive layer comprises an adhesive base material comprising a natural rubber and / or a styrene- (Meth) acrylic ester having an alkyl group in a rubber and / or a styrene-butadiene rubber, wherein the softener is incorporated in an amount of 0.3 to 4% by mass based on the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer, and the graft polymer 10 to 50 parts by mass based on 100 parts by mass of the adhesive base, and the graft polymer has a Mooney viscosity of 60 to 90 Ms1 + 4 (100 DEG C).

Description

Adhesive Film {ADHESIVE FILM}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-sensitive adhesive film, and more particularly to a pressure-sensitive adhesive tape which is formed by forming a pressure-sensitive adhesive film on a tape to bond a wire or a cable Can be used.

Various adhesive films such as insulating tapes used in various electric devices in automobiles, railways, aircrafts, ships, houses, factories, and the like have appropriate flexibility and elongation properties and are excellent in flame retardancy, mechanical strength, heat resistance, electrical insulation, A vinyl chloride type adhesive film obtained by applying a pressure-sensitive adhesive on one side of a substrate made from a resin composition containing a vinyl chloride resin as a raw material is used.

In the base material of the adhesive film, a softening agent is generally blended to soften the base material. However, there has been a case where the softener migrates from the base material to the pressure-sensitive adhesive layer over time. When the softening agent migrates to the pressure-sensitive adhesive layer, the pressure-sensitive adhesive softens and is squeezed (side stick) on the side of a product made of a wound roll, or the cohesive force or adhesive force of the pressure- And it may cause peeling from the adherend. Further, when the adhesive film is peeled off, a part of the pressure-sensitive adhesive agent and a softening agent remain on the adherend to contaminate the adherend.

As an adhesive film for suppressing the migration of such a softener, there has been proposed an adhesive film provided with a curing type primer between a soft substrate and a pressure sensitive adhesive layer (for example, Patent Document 1 and Patent Document 2). However, in these adhesive films, when the adhesive surface is protected by the substrate separator or when the back surface of the substrate (surface on which the adhesive surface is not formed) is not surface-treated, the surface of the pressure sensitive adhesive layer of the overlapped one adhesive film And the back surface of the other adhesive film come into direct contact with each other, and the movement of the softening agent occurs between the adhesive films. Therefore, there is a problem that the movement of the softening agent can not be sufficiently suppressed unless the adhesive surface or the back surface is protected.

Japanese Patent Application Laid-Open No. 11-263946 Japanese Patent Application Laid-Open No. 2002-146274

It is an object of the present invention to provide an adhesive film which has less migration of a softening agent from a base material to a pressure sensitive adhesive, is excellent in adhesive force, rewinding force and holding force, and has less adhesive residue to the adherend.

The present invention achieves the above object and has the following points.

(1) A pressure-sensitive adhesive film comprising a substrate comprising a vinyl chloride resin composition and a pressure-sensitive adhesive layer formed on at least one side of the substrate, wherein the pressure-

(i) an adhesive base material comprising a natural rubber and / or a styrene-butadiene rubber,

(ii) a graft polymer obtained by graft-polymerizing a (meth) acrylic acid ester having an alkyl group in a natural rubber and / or a styrene-butadiene rubber, and

(iii) Softener

Lt; / RTI >

(A) a softener is compounded in an amount of 0.3 to 4% by mass with respect to the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer,

(B) the graft polymer is blended in an amount of 10 to 50 parts by mass based on 100 parts by mass of the adhesive base comprising the natural rubber and / or the styrene-butadiene rubber,

(C) an adhesive film having a Mooney viscosity of 60 to 90 Ms1 + 4 (100 DEG C) according to JIS K 6300 in terms of the Mooney viscosity of the graft polymer.

(2) The adhesive film of (1) above, wherein the vinyl chloride resin composition contains 50% by mass or more of a vinyl chloride resin with respect to the total amount of the resin component.

(3) A pressure-sensitive adhesive film according to (1) above, wherein graft polymer is graft-polymerized with 60 to 80 mass% of styrene-butadiene rubber and 20 to 40 mass% of a (meth) acrylic acid ester having an alkyl group.

(4) The positive resist composition as described in (1) above, wherein the (meth) acrylic acid ester having an alkyl group is at least one compound selected from the group consisting of methyl (meth) acrylate, n-butyl (meth) acrylate, ≪ / RTI >

(5) The adhesive film according to the above item (1), wherein the softener is diisononyl phthalate.

(6) A pressure-sensitive adhesive film according to the above item (1), wherein the softening agent is contained in an amount of 15 to 45 mass% based on the total amount of the resin component of the vinyl chloride resin composition.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to obtain a pressure-sensitive adhesive film having a small amount of softening agent migration from a substrate to a pressure-sensitive adhesive, excellent adhesive force, rewinding force and holding power,

The pressure-sensitive adhesive film of the present invention is a pressure-sensitive adhesive film comprising a substrate comprising a vinyl chloride resin composition and a pressure-sensitive adhesive layer formed on at least one side of the substrate, wherein the pressure-sensitive adhesive layer comprises 0.3 to 4% Is formed by a pressure-sensitive adhesive containing a graft polymer obtained by graft-polymerizing a (meth) acrylic acid ester having an alkyl group in a natural rubber and / or a styrene-butadiene rubber.

<I. Equipment>

The vinyl chloride resin composition constituting the base material is not particularly limited as long as it contains a vinyl chloride resin as a main component of the resin component. The vinyl chloride resin is a homopolymer resin which is a single polymer of conventionally known vinyl chloride or various conventionally known copolymer resins, and is not particularly limited.

As the copolymer resin, conventionally known copolymer resins can be used, and copolymer resins of vinyl chloride and vinyl esters such as vinyl chloride-vinyl acetate copolymer resin and vinyl chloride-vinyl propionate copolymer resin; Vinyl chloride-butyl acrylate copolymer resin, vinyl chloride-2-ethylhexyl acrylate copolymer resin, and other vinyl chloride-acrylate copolymer resins; A copolymer resin of vinyl chloride and olefins such as vinyl chloride-ethylene copolymer resin, vinyl chloride-propylene copolymer resin and the like; Vinyl chloride-acrylonitrile copolymer resin, and the like. Particularly preferably, a homopolymer resin, a vinyl chloride-ethylene copolymer resin, a vinyl chloride-vinyl acetate copolymer resin, or the like which is a single polymer of vinyl chloride can be used. The content of the comonomer in the copolymer resin is not particularly limited and can be determined according to the required quality such as moldability.

The proportion of the vinyl chloride resin to the total amount of the resin component of the vinyl chloride resin composition is, for example, 50% by mass or more, preferably 80% by mass or more, and more preferably 90 to 100% by mass. If necessary, a flame retardant, a stabilizer, an antioxidant, a pigment, an inorganic filler, and the like may be added.

As the vinyl chloride resin, a soft vinyl chloride resin can be preferably used. As the soft vinyl chloride resin, a vinyl chloride resin having a viscosity average polymerization degree of 900 to 1300 may be added in an appropriate amount of a stabilizer and a softener. If the degree of polymerization of the vinyl chloride resin is less than 900, the base material may be soft and the heat resistance may be lowered. On the other hand, when the degree of polymerization is more than 1300, the dispersibility of the additive of the vinyl chloride resin-based resin composition deteriorates and the flexibility of the adhesive film may deteriorate. The polymerization degree was obtained by dissolving 200 g of the resin in 50 ml of nitrobenzene and measuring the viscosity of the polymer solution using a Ubbelohde viscometer in a thermostatic chamber at 30 캜 and measuring the viscosity according to JIS K 6720-2.

<Softener>

A softening agent may be added to the substrate to soften the substrate. The type of softening agent that can be used for the substrate is not particularly limited, and known softening agents may be used. As an example, DOP (dioctyl phthalate), DINP (diisononyl phthalate), DINA (diisononyl adipate), DBP (phthalic acid diisocyanate) described in "Adhesive Handbook (Japan Adhesive Industry Association, 3rd edition, P- Dibutyl), dibasic acid esters such as TOTM (tri-2-ethylhexyl trimellitate) and DIDP (diisodecyl phthalate); Liquid rubbers such as liquid polyisobutylene, liquid isoprene, and liquid butene; Aromatic process oil, naphthene process oil, paraffin oil, castor oil, tall oil and the like can be used. These may be used alone or in combination of two or more. The softener ratio is preferably 15 to 45 mass%, more preferably 15 to 30 mass%, based on the whole resin component of the vinyl chloride resin composition. If the softening agent is less than 15 mass%, the base may become hard. On the other hand, if it exceeds 45% by mass, problems such as bending of the base material or shrinkage of the base material may occur during production of the base material.

The thickness of the substrate is not particularly limited, and is preferably 10 to 500 μm, more preferably 12 to 200 μm, and still more preferably 15 to 100 μm. Further, the base material may have a single layer form or a multi-layer form.

The substrate may be subjected to various treatments such as back surface treatment, antistatic treatment, priming treatment and the like as necessary.

&Lt; II. Pressure-sensitive adhesive layer>

The pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer in the present invention is preferably a (meth) acrylate having a softening agent in an amount of 0.3 to 4 mass% based on the pressure-sensitive adhesive and an alkyl group in a natural rubber and / or a styrene-butadiene rubber (hereinafter abbreviated as SBR) Acrylate ester graft polymer.

<Adhesive Base>

The pressure-sensitive adhesive contains natural rubber and / or styrene-butadiene rubber as an adhesive base.

Natural rubber is widely used as a base of an adhesive composition. In addition, SBR is a representative general purpose rubber, and has excellent aging resistance, creep resistance, and antistatic property. Natural rubber and SBR are commercially available.

As the SBR, known or common SBR may be used. The ratio of styrene to butadiene as a monomer component in SBR is not particularly limited. The type or grade of the SBR is not particularly limited, and various types or grades of SBR may be used.

<Softener>

As the softener that can be incorporated into the pressure-sensitive adhesive layer, the above-mentioned known softeners can be used as well as those usable in the substrate.

The content of the softening agent in the pressure-sensitive adhesive layer is 0.3 to 4% by mass, preferably 1 to 3% by mass, based on the pressure-sensitive adhesive. If the content of the softener is less than 0.3% by mass, the migration of the softening agent from the substrate containing the vinyl chloride resin composition can not be inhibited and the cohesive force of the pressure sensitive adhesive decreases, or when the pressure sensitive adhesive force increases with the lapse of the bonding time, Adhesive residue may occur. On the other hand, if the content of the softening agent exceeds 4% by mass, the cohesive force of the initial pressure-sensitive adhesive may be insufficient regardless of the elapse of time, and the adhesive may remain when the pressure-sensitive adhesive film is peeled off. When the softening agent is present in the adhesive in the above specified amount, migration of the softening agent from the base to the pressure sensitive adhesive can be suppressed by the principle of chemical equilibrium.

The content of the softening agent in the present invention is measured by the following method.

Apparatus name: gas chromatography (GC, manufactured by Nihon Denshi Co., Ltd.)

Test method: The pressure-sensitive adhesive of the pressure-sensitive adhesive film is peeled off with normal hexane, extracted, and dried at 40 캜.

&Lt; Graft Polymer &

The graft polymer of the present invention is excellent in anti-smoothing property that the deterioration of the adhesive property is hard to occur and also has an effect of further suppressing the deterioration of the cohesive force of the adhesive due to the migration of the softener. Further, since the (meth) acrylic acid ester having an alkyl group is grafted, the adhesion to various adherends and the rewinding force are improved, and the workability at the low temperature is also improved. The blending amount of the graft polymer is 10 to 50 parts by mass, preferably 20 to 50 parts by mass, relative to 100 parts by mass of the adhesive base comprising natural rubber and / or SBR. When the graft polymer is less than 10 parts by mass, proper adhesion and rewinding force to various adherends may not be obtained. On the other hand, if the amount of the graft polymer exceeds 50 parts by mass, the graft polymer may become too hard to be used as a pressure-sensitive adhesive.

The graft polymer has both a constituent molecule having a high polarity (a (meth) acrylic ester having an alkyl group) and a constituent molecule having a low polarity (a natural rubber, SBR) in the molecular structure of the graft polymer, The adhesion to the complex, and the high rewinding force can be exerted. Therefore, it is necessary to polymerize the graft polymer in such a manner that 60 to 80 mass% of the natural rubber and / or SBR and 20 to 40 mass% of the (meth) acrylic ester having the alkyl group are contained in the graft polymer desirable. It is more preferable to polymerize 65 to 75 mass% of natural rubber and / or SBR and 25 to 35 mass% of (meth) acrylic acid ester having an alkyl group.

Examples of such alkyl (meth) acrylate esters include methyl (meth) acrylate (hereinafter abbreviated as "MMA"), ethyl (meth) acrylate, n-propyl (meth) acrylate, (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (Meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, undecyl (meth) acrylate, isonodecyl Tetradecyl (meth) acrylate, etc. These may be used alone or in combination of two or more. Among them, methyl (meth) acrylate, n-butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate are preferably used.

The Mooney viscosity of the graft polymer in the present invention is 60 to 90 Ms 1 + 4 (100 ° C), preferably 70 to 90 Ms 1 + 4 (100 ° C). If the Mooney viscosity of the graft polymer is less than 60 Ms &lt; 1 + 4 &gt; (100 DEG C), resistance to the flowability of the pressure sensitive adhesive is weak and high cohesive force may not be obtained. On the other hand, when the Mooney viscosity exceeds 90 Ms1 + 4 (100 deg. C), the cohesive force of the pressure-sensitive adhesive may become excessively high. The method for adjusting the Mooney viscosity may be a known method and is not particularly limited. For example, mastication by an open roll, Banbury mixer, kneader or the like can be mentioned. Among them, the method of performing the Soviet Union with the open roll is preferable in view of easy adjustment of the Mooney viscosity. The measurement of Mooney viscosity is based on JIS K-6300.

<Additives>

Various additives such as various stabilizers such as plasticizers, ultraviolet absorbers and antioxidants, tackifiers, fillers, colorants, antistatic agents, foaming agents, surfactants and the like may be added to the pressure-sensitive adhesive as necessary.

The tackifier resin used in the tackifier can be selected in consideration of softening point, compatibility with each component, and the like. For example, petroleum resins such as terpene resins, rosin resins, hydrogenated rosin resins, coumarone-indene resins, styrene resins, aliphatic and alicyclic resins, terpene-phenol resins, xylene resins, other aliphatic hydrocarbon resins or aromatic hydrocarbon resins And the like. The softening point of the tackifier resin is from 65 to 170 캜, preferably from 80 to 150 캜. The blending amount of the tackifier resin is in the range of 50 to 200 parts by mass, preferably 100 to 150 parts by mass with respect to 100 parts by mass of the pressure-sensitive adhesive. If the tackifier resin is too small, a high adhesive force can not be exerted on the adhesive film in some cases. On the other hand, if the tackifier resin is too large, the adhesive force of the adhesive film may be excessively high.

&Lt; III. Adhesive Film>

The pressure-sensitive adhesive film of the present invention is composed of a substrate comprising a vinyl chloride resin composition and a pressure-sensitive adhesive layer formed on at least one side of the substrate. Normally, the pressure-sensitive adhesive layer is formed on only one side of the substrate, but it may be formed on both sides. The pressure-sensitive adhesive film can be produced by forming a pressure-sensitive adhesive layer on at least one side of a substrate using a conventional method such as a coating method. Further, the pressure-sensitive adhesive layer may be protected by a release substrate (release liner). The adhesive film may have another layer (for example, an intermediate layer, a subbing layer or the like) within a range not to impair the effect of the present invention.

The means for molding the base material is not particularly limited, but the various materials may be uniformly melt-kneaded or the like using various mixing apparatuses (single or twin screw extruder, roll, Benbury mixer, various kneader, etc.) , Shaping the mixture into a base material by a calendar molding machine, and cutting the mixture to a desired tape width. For the roll arrangement in the calender molding, for example, known methods such as L type, reverse L type and Z type can be used, and the roll temperature is usually in the range of 150 to 200 DEG C, preferably 160 to 180 DEG C .

The means for applying the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer to the substrate is not particularly limited, and examples thereof include a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater and a spray coater. The thickness of the pressure-sensitive adhesive layer after drying can be appropriately selected within a range that does not impair the tackiness and handleability, but the thickness of the pressure-sensitive adhesive layer is, for example, 5 to 100 占 퐉, preferably 10 to 50 占 퐉. If it is thinner, the adhesive force and the rewinding force may be lowered. On the other hand, if it is larger than this, the coating performance may be deteriorated and the adhesive may easily remain.

The pressure-sensitive adhesive film of the present invention can be produced as an adhesive tape (rolled-up adhesive film) in the form of a rolled-up state or shape by winding in the form of a roll, and as a pressure-sensitive adhesive sheet when not rolled.

When the adhesive film is formed by the adhesive tape, the release agent is coated on the back surface (adhesive surface non-formation surface) of the adhesive film to provide the back surface treatment layer so that the movement of the softener between the adhesive films can be more reliably . Similarly, since the release liner is interposed between the surface of the pressure-sensitive adhesive layer of one adhesive film and the back surface of the other pressure-sensitive adhesive film, the migration of the softening agent between the pressure- It can certainly interfere.

[Example]

Hereinafter, the present invention will be described in more detail based on examples and comparative examples, but the present invention is not limited to these examples.

The materials used in the examples are shown below.

TH-1000 (manufactured by TAIYO ENVI Co., Ltd., polymerization degree: 1100), TH-1300 (manufactured by TAIYO ENVI Co., Ltd., degree of polymerization: 1300)

(2) Softener: DINP (manufactured by DIC)

(3) Tackifier: C5C9 petroleum resin (manufactured by ETGO Chemical Co., softening point 94 DEG C)

(4) Stabilizer: Ca-Zn stabilizer (Mizusawa Chemical Industries, Ltd.)

(5) Modifier: MBS (manufactured by Nippon Gosei Rubber Co., Ltd.)

(6) Graft polymer obtained by graft-polymerizing MMA on natural rubber: MEGAPOLY 30 (graft polymer obtained by graft polymerization of 30 mass% of MMA to 70 mass% of natural rubber manufactured by ASIATIC Co., Ltd.)

(7) Graft polymer obtained by graft-polymerizing MMA on natural rubber: Megapoly 50 (graft polymer obtained by graft polymerization of 50 mass% of natural rubber and 50 mass% of MMA manufactured by Asiatica)

(8) Graft polymer obtained by graft polymerization of MMA to SBR: SGMM-30 (graft polymer obtained by grafting 30 mass% of MMA to 70 mass% of SBR manufactured by Denkim Chemical)

(9) Graft polymer obtained by graft-polymerizing butyl methacrylate on SBR: SGBM-30 (a graft polymer obtained by graft-polymerizing 30 mass% of butyl methacrylate on 70 mass% of SBR manufactured by Denkim Corporation)

(10) Graft polymer obtained by graft-polymerizing butyl acrylate on SBR: SGBA-30 (graft polymer obtained by graft-polymerizing 30 mass% of butyl acrylate on 70 mass% of SBR manufactured by Denki Kagaku Co., Ltd.)

In Table 1 and Table 2, "initial adhesive force" was measured in accordance with JIS Z 0237. The adhesive film was allowed to stand for 24 hours or more in an evaluation test room set at a temperature of 23 ± 2 ° C and a humidity of 50 ± 5% RH. The adhesive film was applied to various adherends (SUS, PE, PVC, PET) And the 180 degree peel strength (N / 10 mm) was measured after 30 minutes. 1 N / 10 mm or more.

In Table 1 and Table 2, the "change in adhesive force with time of SUS versus SUS" was measured in accordance with JIS Z 0237. The adhesive film was allowed to stand for 24 hours or more in an evaluation test room set at a temperature of 23 ± 2 ° C and a humidity of 50 ± 5% RH. The adhesive film was pasted on a SUS304 steel plate by reciprocating twice with a 2000 g roller. And the 180 degree peel strength (N / 10 mm) was measured after one month. The adhesive film was allowed to stand in an evaluation test room set at -20 占 2 占 폚 for 24 hours or more, and then the adhesive film was stuck to the SUS304 steel sheet by reciprocating the 2000 g roller twice. After 30 minutes, the 180 degree peel strength (N / 10 mm) was measured. It is preferable that all of them are 1 N / 10 mm or more.

In Table 1 and Table 2, the "holding force" was measured in accordance with JIS Z 0237. After the pressure-sensitive adhesive film was allowed to stand in an evaluation test room set at a temperature of 23 占 2 占 폚 and a humidity of 50 占 5% RH for 24 hours or more, an SUS304 steel sheet was used as an adherend, and an adhesive film of 20 占 20 mm in size was stuck thereto. Thereafter, a load of 500 g was applied in a direction of gravity in an atmosphere of 40 占 폚, and the fall time (minute) of the weight was measured at n = 3 or more. The values in the above table are average values. Preferably 300 minutes or longer.

In Table 1 and Table 2, the "rewinding force" was measured in accordance with JIS Z 0237. The value obtained when the pressure-sensitive adhesive film was wound for about 3 seconds at a rate of 15.8 m / min after the pressure-sensitive adhesive film was allowed to stand for 24 hours or more in an evaluation chamber set at a temperature of 23 ± 2 ° C and a humidity of 50 ± 5% Respectively. The values in the above table are average values. 6 to 8 N / 10 minutes.

In Table 1 and Table 2, "peeling" was measured in accordance with JIS G 4305. After the adhesive film was allowed to stand in an evaluation test room set at a temperature of 23 ± 2 ° C and a humidity of 50 ± 5% RH for 24 hours or more, the adhesive film was pressed against the SUS304 steel sheet and visually observed after 7 days from the initial 30 minutes His rank was assessed by the following criteria. The pressing method was a reciprocating method using a roller of 200 g in accordance with JIS K 6253 and reciprocating once at a pressing speed of 5 mm / s.

Good: without peeling

Bad: With peeling

In Table 1 and Table 2, "adhesive residue" was measured in accordance with JIS G 4305. After the pressure-sensitive adhesive film was allowed to stand for 24 hours or more in an evaluation test room set at a temperature of 23 ± 2 ° C and a humidity of 50 ± 5% RH, the pressure-sensitive adhesive film was pressed against the SUS304 steel sheet. At a rate of 300 mm / min. The surface of the SUS304 steel sheet after peeling was visually observed to evaluate its superiority with the following criteria. The pressing method was a reciprocating method using a roller of 200 g in accordance with JIS K 6253 and reciprocating once at a pressing speed of 5 mm / s.

Good: without adhesive residue

Bad: with adhesive residue

(Example 1)

(i) 100 parts by weight of a vinyl chloride resin having a degree of polymerization of 1100 (TH-1000 manufactured by TAIYO ENVISE), 25 parts by weight of DINP (manufactured by DIC) as a softening agent, and 5 parts by weight of a C5C9-based petroleum resin , 2 parts by mass of MBS (manufactured by Nippon Gosei Rubber Co., Ltd.) as a modifier, 2 parts by mass of a Ca-Zn type stabilizer (manufactured by Mizusawa Chemical Co., Ltd.) as a stabilizer, and 0.2 parts by mass of St acid And 2 parts by mass of MMA (manufactured by Kanegaba Chemical Co., Ltd.) were mixed with a Henschel mixer, and a sheet having a thickness of 120 μm was formed by calender molding (roll temperature: 145 to 180 ° C.). The sheet was wound with a specified length (20 m) and annealed at 120 캜 for 8 hours to obtain a substrate.

(ii) 20 parts by mass (Mooney viscosity = 80) of a graft polymer obtained by graft-polymerizing 30 mass% of MMA to 70 mass% of natural rubber (Mooney viscosity = 80) and 100 parts of natural rubber (Mooney viscosity = 45) 100 parts by mass of a terpene resin (YS Resin PX-1000 manufactured by Yasuhara Chemical Co., Ltd.) as a tackifier resin and 4 parts by mass of 4 ethyl 6-tert-butylphenol (manufactured by Kawaguchi Chemical Co., 2 parts by mass of Anthai W-500 manufactured by Kogyo K.K.) was dissolved in toluene so as to be a 30% by mass base, followed by blending to obtain a pressure-sensitive adhesive.

(iii) A pressure-sensitive adhesive was applied to one side of the base material by a reverse roll coater, and after drying, a pressure-sensitive adhesive layer having a thickness of 20 占 퐉 after drying was formed and cut into a tape having a width of 25 mm to obtain an adhesive film.

(Examples 2 to 9)

A pressure-sensitive adhesive film was produced in the same manner as in Example 1, except that the compositions of the pressure-sensitive adhesive and the substrate were variously changed as shown in Table 1.

(Comparative Examples 1 to 6)

A pressure-sensitive adhesive film was produced in the same manner as in Example 1 except that the composition of the pressure-sensitive adhesive was changed variously as shown in Table 2.

As apparent from Tables 1 and 2, according to the present invention, initial adhesion (after 30 minutes from the application) of various adherends (SUS, PE, PVC, PET) is excellent. In addition, it maintains high adhesive strength even with a change in the adhesive strength with SUS (low temperature of -20 ° C after one month from the initial 30 minutes). From this, it can be seen that an adhesive film with less migration of the softening agent from the base material to the pressure sensitive adhesive, excellent adhesive force, rewinding force and holding force, and less adhesive residue to the adherend can be easily obtained.

Claims (6)

A pressure-sensitive adhesive film comprising a substrate comprising a vinyl chloride resin composition and a pressure-sensitive adhesive layer formed on at least one side of the substrate, wherein the pressure-
(i) an adhesive base material comprising a natural rubber and / or a styrene-butadiene rubber,
(ii) a graft polymer obtained by graft-polymerizing a (meth) acrylic acid ester having an alkyl group in a natural rubber and / or a styrene-butadiene rubber, and
(iii) Softener
Lt; / RTI &gt;
(A) a softener is compounded in an amount of 0.3 to 4% by mass with respect to the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer,
(B) the graft polymer is blended in an amount of 10 to 50 parts by mass based on 100 parts by mass of the adhesive base comprising the natural rubber and / or the styrene-butadiene rubber,
(C) the Mooney viscosity of the graft polymer is 60 to 90 Ms1 + 4 (100 DEG C) according to JIS K 6300,
A pressure-sensitive adhesive film comprising a softening agent in an amount of 15 to 45 mass% based on the total amount of the resin component of the vinyl chloride resin composition. The adhesive film according to claim 1, wherein the vinyl chloride resin composition contains 50% by mass or more of a vinyl chloride resin with respect to the total amount of the resin component. The adhesive film according to claim 1, wherein the graft polymer is graft-polymerized with 60 to 80 mass% of a styrene-butadiene rubber and 20 to 40 mass% of a (meth) acrylic acid ester having an alkyl group. The composition according to claim 1, wherein the (meth) acrylic acid ester having an alkyl group is selected from the group consisting of methyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl Adhesive film. The adhesive film according to claim 1, wherein the softener is diisononyl phthalate. delete