JP2003003133A - Double-sided adhesive sheet without having releasing liner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double-sided adhesive sheet without having a releasing liner, exhibiting a good rewinding property not even having a releasing liner and excellent in adhesive property. SOLUTION: This double-sided adhesive sheet without having a releasing liner is obtained by forming (A) an adhesive layer consisting of an adhesive composition containing a resin component consisting of a polyester having a polycarbonate structural part as a main component on one side surface of a substrate, and also (B) another adhesive layer consisting of an adhesive composition other than that constituting the above adhesive layer (A) on another side surface of the substrate, and overlapping the adhesive layers (A) with (B). The polycarbonate structural part has preferably a recurring unit expressed by formula (1) (wherein, R is a 2-20C straight chain or branched hydrocarbon group).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a double-sided PSA sheet having no release liner.

[0002]

2. Description of the Related Art Conventionally, a double-sided pressure-sensitive adhesive tape is composed of a tape body having a pressure-sensitive adhesive layer on both sides of a substrate and one or two release liners for protecting the pressure-sensitive adhesive layer.
In general, both the tape body and the release liner are often wound into a roll. As the release liner, papers such as high-quality paper and glassine paper and plastic films coated with a release treatment agent such as silicone resin are widely used.

However, the release liner is used to protect the surface of the pressure-sensitive adhesive layer and becomes unnecessary when the double-sided pressure-sensitive adhesive tape is used. Therefore, in a production line or the like in which the double-sided pressure-sensitive adhesive tape is industrially used, a step of peeling the release liner occurs, and it is necessary to treat the release liner as waste.

Further, conventionally, a double-sided adhesive tape without a release liner, in which acrylic adhesives having different compositions are provided on both sides of a base material, a rubber-based adhesive on one side, and an acrylic-based adhesive on the other side are provided. There is an example where a double-sided pressure-sensitive adhesive tape without a release liner is proposed, but in each case there is a problem that rewinding is heavy, and a double-sided pressure-sensitive adhesive tape without a release liner that improves this point is demanded. .

[0005]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a double-sided PSA sheet which does not have a release liner and has a good rewinding property and which does not have a release liner. Another object of the present invention is to provide a double-sided pressure-sensitive adhesive sheet which does not have a release liner and which can be easily rewound even when the pressure-sensitive adhesive layers are superposed and wound on each other, and which has excellent adhesiveness. It is in.

[0006]

Means for Solving the Problems As a result of intensive studies to achieve the above-mentioned object, the present inventors have found that a pressure-sensitive adhesive composition containing a specific polymer having a polycarbonate structure as two pressure-sensitive adhesive layers of a double-sided pressure-sensitive adhesive sheet. An adhesive layer made of a material,
When used in combination with a pressure-sensitive adhesive layer made of another pressure-sensitive adhesive composition, it has good rewindability even when wound in a roll without a release liner, and also has excellent pressure-sensitive adhesiveness as a double-sided pressure-sensitive adhesive sheet. It was found that the present invention has been completed.

That is, according to the present invention, one surface of the substrate is
A pressure-sensitive adhesive layer (A) made of a pressure-sensitive adhesive composition containing a resin component whose main component is a polyester having a polycarbonate structure is formed, and the pressure-sensitive adhesive layer (A) is formed on the other surface. A pressure-sensitive adhesive layer (B) made of a pressure-sensitive adhesive composition other than the pressure-sensitive adhesive composition is formed, and the pressure-sensitive adhesive layer (A) and the pressure-sensitive adhesive layer (B) are superposed on each other. Provided is a double-sided PSA sheet having no release liner.

In the present invention, the pressure-sensitive adhesive layer (A) and the pressure-sensitive adhesive layer (B) may be superposed and wound in a roll shape. The polycarbonate structure has the following formula (1)

[Chemical 2] (In the formula, R represents a linear or branched hydrocarbon group having 2 to 20 carbon atoms) and preferably has a repeating unit. The unwinding force may be 3 N / 20 mm or less.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A double-sided pressure-sensitive adhesive sheet without a release liner of the present invention comprises a base material and a resin component formed on one surface of the base material and containing a polyester having a polycarbonate structure as a main component. A pressure-sensitive adhesive layer (A) composed of a pressure-sensitive adhesive composition containing (hereinafter, sometimes referred to as “pressure-sensitive adhesive composition (A)”), and the above-mentioned formed on the other surface of the base material. At least a pressure-sensitive adhesive layer (B) composed of a pressure-sensitive adhesive composition other than the pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer (A) (hereinafter sometimes referred to as “pressure-sensitive adhesive composition (B)”). ing.

[Substrate] The material of the substrate (support) is
There is no particular limitation, and a known base material for a double-sided pressure-sensitive adhesive tape can be used. As the material of the base material, for example,
Paper such as high-quality paper, glassine paper, kraft paper, Japanese paper, etc .; woven or non-woven fabric such as rayon, glass, polyester, etc., alone or mixed; plastic such as cellophane, polyethylene, polypropylene, polyethylene terephthalate, etc. A plastic film; a rubber sheet made of natural rubber, butyl rubber or the like; a foam sheet made of polyurethane, polychloroprene rubber or the like; a metal foil such as an aluminum foil or a copper foil; and a composite of these. As the substrate, a plastic film such as a polyester film or a porous material such as paper or nonwoven fabric can be preferably used. The base materials can be used alone or in combination of two or more kinds. The base material may be a single layer or multiple layers.

The thickness of the base material is not particularly limited and is, for example, 1
It can be selected from the range of about 100 μm, preferably about 10 to 50 μm.

[Adhesive Layer (A)] The adhesive layer (A) is formed on one surface of the base material and contains a resin component whose main component is polyester having a polycarbonate structure. It consists of an agent composition. In the resin component, the polyester having a polycarbonate structure portion (hereinafter sometimes referred to as “carbonate-based polyester”) is not particularly limited as long as it is a polyester having at least a polycarbonate structure portion in the molecule.
Further, in the carbonate-based polyester, the content ratio of the polycarbonate structure portion is not particularly limited and can be appropriately selected according to the adhesiveness and the like. The carbonate-based polyester can be used alone or in combination of two or more kinds.

In the present invention, in the carbonate type polyester, the polycarbonate structure part has the following formula (1)

[Chemical 3] (In the formula, R represents a linear or branched hydrocarbon group having 2 to 20 carbon atoms) and preferably has a repeating unit.

In the above formula (1), the repeating degree of the repeating unit is not particularly limited and can be appropriately selected depending on the kind of the intended carbonate polyester.

In the formula (1), examples of the hydrocarbon group represented by R include an alkylene group, a cycloalkylene group and an arylene group, and an alkylene group can be preferably used. Therefore, as R, for example, ethylene,
A straight-chain or branched-chain alkylene group having 2 to 20 carbon atoms such as trimethylene (propylene), methylethylene (isopropylene), tetramethylene (butylene), hexamethylene, 3-methyl (pentamethylene), and octamethylene group. Can be used.

Such a carbonate-based polyester can be obtained, for example, by a condensation reaction using at least a (poly) carbonate diol and / or a (poly) carbonate dicarboxylic acid. More specifically, as the carbonate-based polyester, for example, (poly)
Examples thereof include a carbonate-based polyester synthesized from a diol component containing at least a carbonate diol and a dicarboxylic acid component, and a carbonate-based polyester synthesized from a dicarboxylic acid component containing at least a (poly) carbonate dicarboxylic acid and a diol component. .

In the present invention, as the carbonate type polyester, a carbonate type polyester synthesized from a diol component containing at least a (poly) carbonate diol and a dicarboxylic acid component is particularly preferable. Examples of the (poly) carbonate diol include (poly) carbonate
Hexamethylene carbonate diol, (poly) 3-methyl (pentamethylene) carbonate diol, (poly) trimethylene carbonate diol, and copolymers of these may be mentioned. The diol component or the (poly) carbonate diol can be used alone or in combination of two or more kinds. When the (poly) carbonate diol is a polycarbonate diol, the degree of polymerization is not particularly limited.

Examples of commercial products of (poly) carbonate diol include, for example, trade name "PLACCEL CD208.
PL ”, product name“ PLACCEL CD210PL ”,
Product name "PLACCEL CD220PL", product name "PLACCEL CD208", product name "PLACC
EL CD210 ", product name" PLACCEL CD2
20 ", product name" PLACCEL CD208HL ",
Product name "PLACCELCD210HL", product name "P
LACCEL CD220HL "[above, Daicel Chemical Industries Ltd. make] etc. are mentioned.

As the diol component, in addition to the (poly) carbonate diol, if necessary, a component such as ethylene glycol, propylene glycol, butanediol, hexanediol, octanediol, decanediol or octadecanediol may be used in combination. The amount of these other diols used is 50% by weight of the total diol components.
The following is particularly preferable, and it is 30% by weight or less. Also,
In order to increase the molecular weight of the polymer, a trifunctional or higher functional polyol may be added in a small amount (for example, 10% by weight or less).

As the dicarboxylic acid component, a dicarboxylic acid component containing an aliphatic or alicyclic hydrocarbon group having 2 to 20 carbon atoms as a molecular skeleton or a reactive derivative thereof as an essential component is preferably used. be able to. In the dicarboxylic acid or reactive derivative thereof having a molecular skeleton of an aliphatic or alicyclic hydrocarbon group having 2 to 20 carbon atoms, the hydrocarbon group may be linear or branched. Good. Representative examples of such a dicarboxylic acid or a reactive derivative thereof include succinic acid, methylsuccinic acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, 1,12-dodecanedioic acid and 1,14-tetradecanedioic acid. , Tetrahydrophthalic acid, endomethylenetetrahydrophthalic acid, and their acid anhydrides and lower alkyl esters. The dicarboxylic acid components can be used alone or in combination of two or more.

Therefore, in the present invention, as the carbonate-based polyester, a diol component containing (poly) carbonate diol as an essential component and a dicarbon having an aliphatic or alicyclic hydrocarbon group having 2 to 20 carbon atoms as a molecular skeleton. A carbonate-based polyester with a dicarboxylic acid component containing an acid or a reactive derivative thereof as an essential component is suitable. Such a carbonate-based polyester can be obtained by an esterification reaction using an appropriate catalyst and the like according to a conventional method. In this reaction, it is desirable that the diol component and the dicarboxylic acid component are in equimolar reaction, but either one may be used in excess to promote the esterification reaction.

In the present invention, the carbonate-based polyester preferably has a weight average molecular weight of 20,000 or more (preferably 30,000 or more) from the viewpoint of cohesive force and the like. The upper limit of the molecular weight of the carbonate-based polyester is not particularly limited, but its weight average molecular weight is usually 100,000 or less.

In the present invention, the resin component (particularly carbonate-based polyester) contained in the pressure-sensitive adhesive composition (A) (the pressure-sensitive adhesive composition relating to the pressure-sensitive adhesive layer (A)) is usually cross-linked to It is possible to obtain a pressure-sensitive adhesive having excellent adhesion and removability. The cross-linking method for cross-linking the resin component (particularly the carbonate-based polyester) is not particularly limited and may be any, for example, it has a functional group capable of reacting with the hydroxyl group and / or the carboxyl group contained in the carbonate-based polyester. A method using a so-called cross-linking agent, in which a compound is added and reacted, is preferably used. Examples of the cross-linking agent include polyisocyanate compounds, epoxy compounds, aziridine compounds and the like. Among them, polyisocyanate compounds are preferable.

As the polyisocyanate compound,
For example, 1,2-ethylene diisocyanate, 1,4-
Lower aliphatic polyisocyanates such as butylene diisocyanate and 1,6-hexamethylene diisocyanate; cyclopentylene diisocyanate, cyclohexylene diisocyanate, isophorone diisocyanate,
Alicyclic polyisocyanates such as hydrogenated tolylene diisocyanate and hydrogenated xylene diisocyanate;
There are aromatic polyisocyanates such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate and xylylene diisocyanate, and trimethylolpropane / tolylene diisocyanate trimer. Adduct [Nippon Polyurethane Industry Co., Ltd., trade name “Coronate L”], trimethylolpropane / hexamethylene diisocyanate trimer adduct [Nippon Polyurethane Kogyo Co., Ltd., trade name “Coronate HL”], etc. are also used. To be

These cross-linking agents are used alone or in a mixture of two or more. The amount used is appropriately selected depending on the balance with the carbonate-based polyester to be crosslinked and the purpose of use of the pressure-sensitive adhesive composition. Although the amount of the cross-linking agent is not particularly limited, it is generally preferably about 2 to 10 parts by weight with respect to 100 parts by weight of the carbonate-based polyester.

An electron beam curable compound (polyfunctional monomer) can be used as a substantial crosslinking agent. The electron beam curable compound is a compound having a plurality of unsaturated bonds in one molecule, and is capable of causing a crosslinking reaction with an electron beam or the like. As such an electron beam curable compound, a (meth) acrylate-based polyfunctional monomer can be preferably used. Examples of the (meth) acrylate-based polyfunctional monomer include polyethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol monohydroxypenta (meth) acrylate, and dipentaerythritol monohydroxypenta (meth) acrylate. Pentaerythritol hexa (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, trimethylolpropane tri (meth) acrylate, 1,4-butylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, etc. Is included.

The amount of the electron beam curable compound (polyfunctional monomer) to be used depends on the balance with the carbonate polyester to be crosslinked, as well as the crosslinking agent such as the polyisocyanate compound, and the purpose of use of the pressure-sensitive adhesive composition. Can be appropriately selected according to the above, and generally, it is preferably about 3 to 20 parts by weight with respect to 100 parts by weight of the carbonate-based polyester.

In the present invention, as the pressure-sensitive adhesive in the pressure-sensitive adhesive layer (A), the solvent insoluble content is 20% by weight or more and less than 80% by weight (preferably 25% by weight or more 70%) due to crosslinking of the resin component (particularly carbonate type polyester). It is desirable that it is less than wt%). When the solvent-insoluble content is less than 20% by weight, the rewinding property of the double-sided PSA sheet decreases,
Further, if it is 80% by weight or more, the tackiness decreases, which is not preferable. The solvent in the solvent-insoluble portion of the pressure-sensitive adhesive can be appropriately selected depending on the intended use, and examples thereof include aromatic hydrocarbons such as toluene and xylene; aliphatic hydrocarbons such as hexane; alicyclic compounds such as cyclohexane. Hydrocarbons; alcohols such as methanol and ethanol; esters such as ethyl acetate; ketones such as methyl ethyl ketone; glycols such as ethylene glycol; glycol ethers such as propylene glycol monoethyl ether.

In the present invention, the adhesive composition (A) is
Carbonate-based polyester is contained as the main component of the resin component. Specifically, the proportion of the carbonate-based polyester is, for example, 50% by weight based on the total amount of the resin component.
Or more (preferably 80% by weight or more, more preferably 9% by weight)
0 to 100% by weight).

As the resin component of the pressure-sensitive adhesive composition (A), other polyester-based pressure-sensitive adhesives (that is, polyesters having no polycarbonate structure part), acrylic-based pressure-sensitive adhesives, polyurethane-based pressure-sensitive adhesives as well as carbonate type polyesters are used. A resin that is commonly used as a resin component of an adhesive such as an adhesive or a rubber adhesive can be used.

The pressure-sensitive adhesive composition (A) in the present invention contains
In addition to the resin component (carbonate-based polyester, etc.), various conventionally known tackifiers, softeners, plasticizers, antioxidants, conductive agents, etc. may be added. In addition, various conventionally known additives such as inorganic or organic fillers, powders such as metal powders and pigments, particles, foils and the like can be arbitrarily blended.

[Adhesive Layer (B)] The adhesive layer (B) is formed on the other surface of the substrate opposite to the adhesive layer (A) and constitutes the adhesive layer (A). The pressure-sensitive adhesive composition is different from the pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition (B) (the pressure-sensitive adhesive composition relating to the pressure-sensitive adhesive layer (B)) contains the pressure-sensitive adhesive composition (A) (that is, a resin component whose main component is a polyester having a polycarbonate structure portion). It is not particularly limited as long as it is a pressure-sensitive adhesive composition other than the above-mentioned pressure-sensitive adhesive composition). As the pressure-sensitive adhesive composition (B), a known general-purpose pressure-sensitive adhesive such as a natural rubber-based pressure-sensitive adhesive, a synthetic rubber-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, or an acrylic pressure-sensitive adhesive can be used. The pressure-sensitive adhesive in the pressure-sensitive adhesive composition (B) can be used alone or in combination of two or more kinds.

The pressure-sensitive adhesive composition (B) is preferably an acrylic pressure-sensitive adhesive from the viewpoint of adhesive strength, heat resistance, durability and cost. As the acrylic pressure-sensitive adhesive, for example, it is preferable to use an acrylic pressure-sensitive adhesive composed of an acrylic resin in which 50 to 100% by weight of (meth) acrylate having an alkyl group having 4 to 14 carbon atoms is used in the total amount of monomers. it can. Examples of the (meth) acrylate having an alkyl group having 4 to 14 carbon atoms include butyl (meth) acrylate, isobutyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, and (meth). Heptyl acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, isodecyl (meth) acrylate, dodecyl (meth) acrylate, isomyristyl (meth) acrylate, etc. Can be mentioned. In the acrylic pressure-sensitive adhesive, the (meth) acrylate having an alkyl group having 4 to 14 carbon atoms can be used alone or in combination of two or more kinds.

As such an acrylic pressure-sensitive adhesive, one having a glass transition temperature of −10 ° C. or lower is preferable. The acrylic pressure-sensitive adhesive preferably has a solvent insoluble content of 10 to 80% by weight due to crosslinking using a crosslinking agent or the like.

The pressure-sensitive adhesive composition (B) contains various conventionally known tackifiers, softeners, plasticizers, antiaging agents, conductive agents, etc., as in the case of the pressure-sensitive adhesive composition (A). In addition, inorganic or organic fillers, powders such as metal powders and pigments, various conventionally known additives such as particles and foils may be blended.

The double-sided pressure-sensitive adhesive sheet of the present invention is a double-sided pressure-sensitive adhesive sheet with a base material having no release liner. The double-sided pressure-sensitive adhesive sheet is obtained by applying the pressure-sensitive adhesive composition (A) on one surface of the substrate, drying and curing it as necessary, and then applying the pressure-sensitive adhesive composition (B) on the other surface of the substrate. It can be prepared by applying, drying and curing. When applying the pressure-sensitive adhesive composition (A) or the pressure-sensitive adhesive composition (B), a conventional coating method can be adopted.

In the double-sided pressure-sensitive adhesive sheet of the present invention, since the pressure-sensitive adhesive layer (A) is formed of a specific polyester-based pressure-sensitive adhesive, the self-adhesiveness and removability are excellent. Therefore, the double-sided pressure-sensitive adhesive sheet of the present invention can be stored or transported by superposing the pressure-sensitive adhesive layer (A) and the pressure-sensitive adhesive layer (B) on each other without using a release liner. Therefore,
The double-sided pressure-sensitive adhesive sheet of the present invention may be stacked in a sheet shape or may be wound in a roll shape. That is, it may be in the form of a sheet or a tape. In the present invention, the pressure-sensitive adhesive layer (A) and the pressure-sensitive adhesive layer (B) can be suitably used as a double-sided pressure-sensitive adhesive tape that has no release liner and is wound in a roll shape.

In the double-sided pressure-sensitive adhesive sheet of the present invention, the removability of the pressure-sensitive adhesive layer (A) is excellent, and therefore the rewinding property is good. Specifically, the double-sided pressure-sensitive adhesive sheet of the present invention has a rewinding force (that is, the pressure-sensitive adhesive layer (A) at the time of peeling at a temperature of 23 ° C., a width of 20 mm, a peeling angle of 180 °, and a peeling speed of 300 mm / min. The peeling force when the adhesive layer and the pressure-sensitive adhesive layer (B) are bonded together is, for example, 3 N / 20 mm or less (0.
01 to 3 N / 20 mm), preferably 1 N / 20 mm or less (0.01 to 1 N / 20 mm).

Further, since the self-adhesiveness is excellent, the tackiness is good. Specifically, the double-sided pressure-sensitive adhesive sheet of the present invention includes both the pressure-sensitive adhesive layer (A) and the pressure-sensitive adhesive layer (B).
The adhesive strength is the polymethylmethacrylate plate (PMMA
1) under an atmosphere temperature of 23 ° C., a width of 20 mm, a peeling angle of 180 °, and a peeling speed of 300 mm / min.
0 N / 20 mm or more (10-100 N / 20 mm), preferably 12 N / 20 mm or more (12-50 N / 20 m)
m).

The above-mentioned peeling force and adhesive force can be selected by appropriately selecting the type of carbonate-based polyester and the type and amount of additives such as a crosslinking agent in the adhesive composition (B).
It can be controlled by adjusting the degree of crosslinking and the degree of solvent insolubles.

As described above, the double-sided pressure-sensitive adhesive sheet of the present invention is
Even if you do not have a release liner that is unnecessary at the time of use,
It has good rewindability and has sufficient adhesive strength as an adhesive sheet. Therefore, when industrially used in a production line that uses a double-sided pressure-sensitive adhesive sheet (double-sided pressure-sensitive adhesive tape, etc.), the step of peeling the release liner can be omitted, and workability and productivity can be improved, resulting in cost reduction. Is also excellent. Moreover, since it is not necessary to treat the release liner as waste, the waste treatment cost of the release liner can be eliminated and the cost can be greatly improved. Of course, since the waste of the release liner can be eliminated, it is excellent in terms of environment and resources.

[0042]

The present invention will be described in more detail based on the following examples, but the scope of the present invention is not limited by the following examples. In the following, "parts" means "parts by weight".

Preparation Example 1 90 parts of 2-ethylhexyl acrylate and 10 parts of acrylic acid were placed in a reactor equipped with a cooling pipe, a nitrogen introducing pipe, a thermometer, an ultraviolet irradiation device and a stirrer.
Parts, and 2,2'-dimethoxy-2 as a polymerization initiator
-Phenylacetophenone (0.1 part) was added, and UV irradiation was performed in a nitrogen atmosphere to obtain a polymer / monomer mixed liquid (hereinafter, sometimes referred to as "mixed liquid (1)") having a polymerization rate of 14%.

Preparation Example 2 96 parts of butyl acrylate, 40 parts of acrylic acid, and 2,2 'as a polymerization initiator were placed in a reactor equipped with a cooling pipe, a nitrogen introduction pipe, a thermometer, an ultraviolet irradiation device and a stirrer. -Add 0.1 part of dimethoxy-2-phenylacetophenone, irradiate with ultraviolet light in a nitrogen atmosphere, and obtain a polymer / monomer mixture having a polymerization rate of 14% (hereinafter sometimes referred to as "mixture (2)"). Obtained.

(Example 1) A four-neck separable flask was equipped with a stirrer, a thermometer and a water separation tube, and liquid polycarbonate diol [trade name "PLACCEL CD21
0PL ”manufactured by Daicel Chemical Industries, Ltd., hydroxyl value: 11
5.9 KOH mg / g] 200.0 g, succinic anhydride 2
0.51 g, dibutyltin oxide 102 m as a catalyst
g was charged, and in the presence of a small amount of toluene as a solvent for discharging reaction water, the temperature was raised to 190 ° C. with stirring and maintained at this temperature. After a while, distillative separation of water was observed and the reaction started to proceed. The reaction was continued for about 25 hours to obtain a polyester having a weight average molecular weight of 58,000.
The obtained polyester was diluted with toluene to a solid content concentration of 40% by weight to obtain a polymer solution.

A trimethylolpropane / hexamethylene diisocyanate trimer adduct as a cross-linking agent, based on 100 parts of polyester (solid content) of this polymer solution [Nippon Polyurethane Industry Co., Ltd., trade name "Coronate H"
L "] was added to 3 parts (solid content) to obtain a pressure-sensitive adhesive composition.
This adhesive composition was coated with an applicator to a thickness of 38
μm polyethylene terephthalate film (hereinafter,
(Sometimes referred to as “PET film”) and was dried at 130 ° C. for 5 minutes to form a pressure-sensitive adhesive layer (A) [first coated pressure-sensitive adhesive layer] having a thickness of 50 μm. Furthermore, as an after-curing, aging is performed in an atmosphere of 50 ° C. for 2 days, and a single-sided pressure-sensitive adhesive tape (hereinafter referred to as a pressure-sensitive adhesive tape) having a pressure-sensitive adhesive layer (A) made of a pressure-sensitive adhesive composition containing a polyester having a polycarbonate structure portion as a resin component , Sometimes referred to as "single-sided adhesive tape (A)".

Mixture (1) 10 obtained in Preparation Example 1
To 0 part, 0.1 part of trimethylolpropane triacrylate was added and mixed, and then applied to the PET film side surface of the single-sided pressure-sensitive adhesive tape (A), and UV irradiation was performed to obtain a thickness of 50 μm. The pressure-sensitive adhesive layer (B) [second coated pressure-sensitive adhesive layer] was formed to obtain a double-sided pressure-sensitive adhesive tape.

(Example 2) To 100 parts of the mixed solution (2) obtained in Preparation Example 2, 0.1 part of trimethylolpropane triacrylate was added and mixed, and then prepared in Example 1. A double-sided pressure-sensitive adhesive tape was obtained by coating the surface of the single-sided pressure-sensitive adhesive tape (A) on the PET film side and irradiating with ultraviolet rays to form a pressure-sensitive adhesive layer (B) [second coated pressure-sensitive adhesive layer] having a thickness of 50 μm. .

(Comparative Example 1) Butyl acrylate 9 was placed in a reactor equipped with a cooling pipe, a nitrogen introducing pipe, a thermometer and a stirrer.
6 parts, 4 parts of acrylic acid, and 0.1 part by weight of benzoyl peroxide as a polymerization initiator were added, and polymerization was carried out at 65 ° C. for 10 hours in a nitrogen atmosphere in a toluene solvent to obtain an acrylic polymer having a weight average molecular weight of 460,000. Obtained. The resulting acrylic polymer was diluted with toluene to a solid content concentration of 35% by weight to prepare a polymer solution.

Acrylic polymer 1 of this polymer solution
To 00 parts (solid content), 2 parts (solid content) of trade name "Coronate L" [manufactured by Nippon Polyurethane Industry Co., Ltd.] was added as a cross-linking agent to obtain a pressure-sensitive adhesive composition. This pressure-sensitive adhesive composition is applied onto one side of a PET film having a thickness of 38 μm by an applicator and dried at 130 ° C. for 5 minutes to give a pressure-sensitive adhesive layer (C) having a thickness of 50 μm [first applied pressure-sensitive adhesive layer]. ] Was formed. Furthermore, as an after-curing, aging is performed in an atmosphere of 50 ° C. for 2 days, and a single-sided pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer (C) made of a pressure-sensitive adhesive composition containing an acrylic polymer as a resin component (hereinafter, “single-sided tape”). The adhesive tape (C) may be referred to as ").

Mixture (1) 10 obtained in Preparation Example 1
To 0 part, 0.1 part of trimethylolpropane triacrylate was added and mixed, and then applied to the PET film side surface of the single-sided pressure-sensitive adhesive tape (C), and UV irradiation was performed to obtain a thickness of 50 μm. The pressure-sensitive adhesive layer (B) [second coated pressure-sensitive adhesive layer] was formed to obtain a double-sided pressure-sensitive adhesive tape.

(Comparative Example 2) To 100 parts of the mixed solution (2) obtained in Preparation Example 2, 0.1 part of trimethylolpropane triacrylate was added and mixed, and then prepared in Comparative Example 1. A double-sided pressure-sensitive adhesive tape was obtained by applying the composition to the PET film side surface of the single-sided pressure-sensitive adhesive tape (C) and irradiating it with ultraviolet rays to form a pressure-sensitive adhesive layer (B) [second coated pressure-sensitive adhesive layer] having a thickness of 50 μm. .

(Evaluation Test) Examples 1 and 2 and Comparative Example 1
With respect to the double-sided pressure-sensitive adhesive tapes obtained in ~ 2, the solvent-insoluble matter, adhesive strength, and rewinding property were measured by the following methods. The measurement results are shown in Table 1.

(Measurement Method for Solvent Insoluble Content) Examples 1 and 2 and Comparative Example 1 except that a PET film having a thickness of 38 μm and having both surfaces subjected to silicone release treatment is used as the base material of the double-sided adhesive tape. ~ 2, in the same manner as in
2 and a double-sided adhesive tape similar to Comparative Examples 1-2,
Each pressure-sensitive adhesive layer (first coated pressure-sensitive adhesive layer, second coated pressure-sensitive adhesive layer) in the double-sided pressure-sensitive adhesive tape was peeled from the base material (PET film subjected to silicone peeling treatment), and the solvent was insoluble as follows. Minutes were measured. The measurement results are shown in Table 1, "solvent insoluble matter (% by weight)", "first coated adhesive layer", "second
Each is shown in the column of "Coated adhesive layer". About 0.1 g of the adhesive in the adhesive layer is sampled and precisely weighed. About 50 ml
After dipping in toluene at room temperature (about 23 ° C) for 5 days,
The solvent-insoluble component was taken out, dried at 130 ° C. for about 1 hour, and the solid content was weighed. The following formula [X is the solvent-insoluble component (wt%), Y is the weight after drying the solvent-insoluble component (g). , Z
Is the weight (g) of the sampled adhesive], and the solvent insoluble content (% by weight) is calculated. X (% by weight) = (Y / Z) × 100

(Measurement Method of Adhesive Strength) One side of the double-sided adhesive tapes obtained in Examples 1 and 2 and Comparative Examples 1 and 2 (opposite side of the adhesive strength measurement surface) has a thickness of PE of 25 μm.
A T film is stuck together to prepare a sample for measuring the adhesive strength. A sample for measuring the adhesive force having a width of 20 mm and a length of 150 mm was attached to an adherend (a polymethylmethacrylate plate, an aluminum plate) under the condition of one reciprocation of a 2 kg roller, and after 20 minutes from the attachment, the ambient temperature was 23 ° C. The adhesive strength was measured under conditions of a peeling speed of 300 mm / min and a peeling angle of 180 °. The measurement results are shown in Table 1, "Adhesive strength (N / 20 mm)", "first coated adhesive layer", "second
Each is shown in the column of "Coated adhesive layer". If the adherend is a polymethylmethacrylate plate, "against acrylic",
In the case of an aluminum plate, it is shown in the column of "against aluminum".

(Measurement of Rewinding Property) Different pressure-sensitive adhesive layers of two double-sided pressure-sensitive adhesive tapes were bonded to each other, and a PET film having a thickness of 25 μm was bonded to the other surface and left at 50 ° C. for 2 days. A sample for rewinding property measurement is prepared.
20 mm wide and 150 m long at an ambient temperature of 23 ° C
The sample for rewindability measurement of m
Under the conditions of m / min and a peeling angle of 180 °, the double-sided adhesive tapes were peeled off, the peeling force was measured, and the rewinding property was evaluated. The measurement results are shown in Table 1 "Rewindability (N / 20m
m) ”column.

[0057]

[Table 1]

In Examples 1 and 2, the first coated pressure-sensitive adhesive layer was composed of a pressure-sensitive adhesive composition containing a resin component containing polyester having a polycarbonate structure as a main component. In addition, the second coated adhesive layer according to Examples 1 and 2 and the first coated adhesive layer and the second coated adhesive layer according to Comparative Examples 1 and 2 are the first coated adhesive layer according to Examples 1 and 2, respectively. Different from the layer, it is composed of a pressure-sensitive adhesive composition other than the pressure-sensitive adhesive composition containing a resin component containing a polyester having a polycarbonate structure as a main component.

As is clear from the above results, the double-sided pressure-sensitive adhesive sheets according to Examples 1 and 2 of the present invention have a good pressure-sensitive adhesive force and, even though no release liner is used, It can be seen that it has excellent returnability.

[0060]

EFFECTS OF THE INVENTION The pressure-sensitive adhesive sheet of the present invention has a good rewinding property and a good pressure-sensitive adhesive force even without a release liner.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 4F100 AK25G AK41B AK41J AK42                       AK45B AK45J AK45K AK51                       AL05B AT00A BA03 BA07                       BA10B BA10C CA02 EH46                       EJ05 EJ54 GB07 GB31 GB41                       GB71 JL00 JL13B JL13C                       YY00B YY00C                 4J004 AA04 AA05 AA10 AA11 AA14                       AA15 AA17 AB01 CA02 CA06                       CA07 CA08 CB01 CB02 CC02                       DB01 EA01 EA05                 4J040 ED001 ED031 EL022 JB09                       LA06 PA23

Claims (4)

[Claims] 1. A pressure-sensitive adhesive layer (A) made of a pressure-sensitive adhesive composition containing a resin component containing a polyester having a polycarbonate structure as a main component is formed on one surface of a base material, and the other surface is formed. A pressure-sensitive adhesive layer (B) made of a pressure-sensitive adhesive composition other than the pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer (A) is formed on the surface, and the pressure-sensitive adhesive layer (A) and the pressure-sensitive adhesive layer (B) are formed. The double-sided pressure-sensitive adhesive sheet having no release liner, characterized in that 2. The double-sided pressure-sensitive adhesive sheet having no release liner according to claim 1, wherein the pressure-sensitive adhesive layer (A) and the pressure-sensitive adhesive layer (B) are superposed and wound into a roll. 3. The polycarbonate structure has the following formula (1): The release liner according to claim 1 or 2, having a repeating unit represented by the formula (wherein R represents a linear or branched hydrocarbon group having 2 to 20 carbon atoms). Double-sided adhesive sheet. 4. The double-sided pressure-sensitive adhesive sheet having no release liner according to claim 1, which has a rewinding force of 3 N / 20 mm or less.