JP2018197291A - Adhesive tape - Google Patents

Abstract

To provide an adhesive tape less in adhesive enhancement even when being provided to a heat treatment process at a high temperature, and less in reduction of anchor force between an adhesive layer and a substrate during storage.SOLUTION: There is provided an adhesive tape having a structure in which at least a substrate, an anchor layer and an adhesive layer are laminated in this order, in which the adhesive layer contains a silicon compound, the anchor layer contains 100 pts.wt. of a (meth)acrylic copolymer obtained by polymerizing a monomer mixture containing (meth)acrylic acid alkyl ester having 5 to 12 carbon atoms of an alkyl group of 90 to 99 wt.% and a carboxyl group-containing monomer of 1.0 to 10 wt.%, 0.01 to 1.0 pts.wt. of an epoxy compound having a tertiary amine structure and 1 to 10 pts.wt. of an isocyanate compound as curing agents.SELECTED DRAWING: None

Description

The present invention relates to a pressure-sensitive adhesive tape that has little adhesion enhancement even when subjected to a high-temperature heat treatment step, and has a small decrease in anchoring force between a pressure-sensitive adhesive layer and a substrate during storage.

In recent years, adhesive tape has been used in various industrial fields. Temporary fixing of curing sheets and bonding of interior materials in the construction field, fixing of interior parts such as seats and sensors, fixing of exterior parts such as side moldings and side visors in the automotive field, module assembly in the electrical and electronic field, Double-sided adhesive tape is used for attaching the module to the housing. Specifically, for example, a double-sided pressure-sensitive adhesive tape is used for assembly in a portable electronic device (for example, a mobile phone, a portable information terminal, or the like) equipped with an image display device or an input device. More specifically, for example, a double-sided adhesive tape is used to bond a cover panel for protecting the surface of a portable electronic device to the touch panel module or the display panel module, or to bond the touch panel module and the display panel module. It is used. Such a double-sided pressure-sensitive adhesive tape is used, for example, by being punched into a frame shape or the like and arranged around the display screen (for example, Patent Documents 1 and 2). In addition, double-sided adhesive tape is also used for fixing vehicle parts (for example, a vehicle-mounted panel) to a vehicle body.

Depending on the use of the pressure-sensitive adhesive tape, it is necessary to perform a high-temperature heat treatment process while the pressure-sensitive adhesive tape is attached to the adherend, and then peel the pressure-sensitive adhesive tape. For example, in a semiconductor chip manufacturing process, various high-temperature heat treatment steps can be performed in a state where the semiconductor wafer is bonded and reinforced with a double-sided adhesive tape and then the semiconductor wafer is peeled off from the support plate. Done. Here, if the adhesive tape is promoted by high-temperature heat treatment process, it may be difficult to peel the semiconductor wafer from the support plate, or glue may remain on the surface of the semiconductor wafer at the time of peeling. . On the other hand, a silicone compound is blended in the pressure-sensitive adhesive layer. By blending the silicone compound, it is possible to prevent adhesion enhancement by the silicone compound bleed out from the pressure-sensitive adhesive layer.
However, when a silicone compound is blended in the pressure-sensitive adhesive layer, the anchoring force between the pressure-sensitive adhesive layer and the substrate decreases due to the silicone compound bleed out from the pressure-sensitive adhesive during storage of the pressure-sensitive adhesive tape, and the pressure-sensitive adhesive layer and There was a problem that a base material might peel off.

JP 2009-242541 A JP 2009-258274 A

An object of the present invention is to provide a pressure-sensitive adhesive tape that has little increase in adhesion even when subjected to a high-temperature heat treatment step and has a small decrease in anchoring force between a pressure-sensitive adhesive layer and a substrate during storage. .

The present invention is an adhesive tape having a structure in which at least a substrate, an anchor layer and an adhesive layer are laminated in this order, wherein the adhesive layer contains a silicone compound, and the anchor layer is an alkyl group carbon. (Meth) acrylic acid obtained by polymerizing a monomer mixture containing 90 to 99% by weight of (meth) acrylic acid alkyl ester having a number of 5 to 12 and 1.0 to 10% by weight of carboxyl group-containing monomer The pressure-sensitive adhesive tape contains 0.01 to 1.0 part by weight of an epoxy compound having a tertiary amine structure as a curing agent and 1 to 10 parts by weight of an isocyanate compound with respect to 100 parts by weight of the copolymer.
The present invention is described in detail below.

As a method for improving the anchoring force of the pressure-sensitive adhesive tape, it is conceivable to dispose an anchor layer between the pressure-sensitive adhesive layer and the base material. However, the conventional anchor layer cannot prevent bleed out of the silicone compound during storage, and cannot sufficiently improve the anchoring force. As a result of intensive studies, the present inventors have configured the anchor layer with a specific (meth) acrylic copolymer, and combined use of two types of crosslinking agents, an epoxy compound having a tertiary amine structure and an isocyanate compound. By doing so, even when the pressure-sensitive adhesive layer contains a silicone compound, the anchor force can be sufficiently improved, and a decrease in anchor force between the pressure-sensitive adhesive layer and the substrate can be prevented during storage. The headline and the present invention were completed.
This is because the epoxy compound having a tertiary amine structure improves the heat resistance of the anchor layer and prevents the anchor layer from being destroyed by a high-temperature heat treatment process, and also by using an isocyanate compound in combination with the anchor layer. It is considered that the silicone compound can be prevented from migrating.

The pressure-sensitive adhesive tape of the present invention has a structure in which at least a base material, an anchor layer, and a pressure-sensitive adhesive layer are laminated in this order. By disposing a specific anchor layer between the base material and the pressure-sensitive adhesive layer, it is possible to prevent a decrease in anchor force between the pressure-sensitive adhesive layer and the base material during storage.

The base material is not particularly limited. For example, a film or mesh made of a transparent resin such as acrylic, olefin, polycarbonate, vinyl chloride, ABS, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), nylon, urethane, polyimide, or the like. Examples thereof include a film having a shape-like structure and a film having holes.

Although the thickness of the said base material is not specifically limited, A preferable minimum is 12 micrometers and a preferable upper limit is 75 micrometers. When the thickness of the substrate is within this range, the adhesive tape exhibits sufficient strength and can be suitably used for various applications. The minimum with more preferable thickness of the said base material is 25 micrometers, and a more preferable upper limit is 50 micrometers.

It does not specifically limit as an adhesive which comprises the said adhesive layer, Any of a non-curable adhesive and a curable adhesive may be sufficient.
The non-curing pressure-sensitive adhesive is not particularly limited. For example, a rubber-based pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive, a vinyl alkyl ether-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, a polyester-based pressure-sensitive adhesive, a polyamide-based pressure-sensitive adhesive, and a urethane-based pressure-sensitive adhesive. Examples thereof include an adhesive and a styrene / diene block copolymer adhesive.

The curable pressure-sensitive adhesive is not particularly limited, and examples thereof include a photocurable pressure-sensitive adhesive and a thermosetting pressure-sensitive adhesive containing a polymerizable polymer as a main component and a photopolymerization initiator or a thermal polymerization initiator. Such photo-curing pressure-sensitive adhesives and thermosetting pressure-sensitive adhesives are uniformly and rapidly polymerized and integrated by light irradiation or heating, so that the elastic modulus is significantly increased by polymerization and curing. Thus, the adhesive strength can be greatly reduced.
When the adhesive tape of the present invention is used for the purpose of performing a high-temperature heat treatment step while being attached to an adherend and then peeling the adhesive tape, it is preferable to use a photocurable adhesive.

The polymerizable polymer is prepared by, for example, previously synthesizing a (meth) acrylic polymer having a functional group in the molecule (hereinafter referred to as a functional group-containing (meth) acrylic polymer) and reacting with the functional group in the molecule. It can obtain by making it react with the compound (henceforth a functional group containing unsaturated compound) which has a functional group to perform and a radically polymerizable unsaturated bond.

The functional group-containing (meth) acrylic polymer is mainly composed of an acrylic acid alkyl ester and / or a methacrylic acid alkyl ester whose alkyl group usually has 2 to 18 carbon atoms, and this and a functional group-containing monomer, Further, it can be obtained by copolymerizing with other modifying monomers copolymerizable with these by a conventional method, if necessary. This is the same as the case of a general (meth) acrylic polymer which is a polymer having adhesiveness at room temperature. The weight average molecular weight of the functional group-containing (meth) acrylic polymer is usually about 200,000 to 2,000,000.

Examples of the functional group-containing monomer include: carboxyl group-containing monomers such as acrylic acid and methacrylic acid; hydroxyl group-containing monomers such as hydroxyethyl acrylate and hydroxyethyl methacrylate; epoxy group-containing monomers such as glycidyl acrylate and glycidyl methacrylate. Isocyanate group-containing monomers such as isocyanate ethyl acrylate and isocyanate ethyl methacrylate; amino group-containing monomers such as aminoethyl acrylate and aminoethyl methacrylate;
Examples of other modifying monomers that can be copolymerized include various monomers used in general (meth) acrylic polymers such as vinyl acetate, acrylonitrile, and styrene.

The functional group-containing unsaturated compound to be reacted with the functional group-containing (meth) acrylic polymer is the same as the functional group-containing monomer described above according to the functional group of the functional group-containing (meth) acrylic polymer. it can. For example, when the functional group of the functional group-containing (meth) acrylic polymer is a carboxyl group, an epoxy group-containing monomer or an isocyanate group-containing monomer is used. When the functional group is a hydroxyl group, an isocyanate group-containing monomer is used. When the functional group is an epoxy group, a carboxyl group-containing monomer or an amide group-containing monomer such as acrylamide is used. Further, when the functional group is an amino group, an epoxy group-containing monomer is used.

The (meth) acrylic acid alkyl ester-based polymerizable polymer having a radical polymerizable unsaturated bond in the molecule may be used in combination with a polyfunctional oligomer or monomer.
The polyfunctional oligomer or monomer preferably has a molecular weight of 10,000 or less, and more preferably has a molecular weight of 5000 or less so that the three-dimensional network of the pressure-sensitive adhesive layer can be efficiently formed by heating or light irradiation. And the number of radically polymerizable unsaturated bonds in the molecule is 2-20. Such more preferred polyfunctional oligomers or monomers are, for example, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate or Examples thereof include the same methacrylates as described above. Other examples include 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, commercially available oligoester acrylate, and methacrylates similar to those described above. These polyfunctional oligomers or monomers may be used alone or in combination of two or more.

Examples of the photopolymerization initiator include those activated by irradiation with light having a wavelength of 250 to 800 nm. Examples of such photopolymerization initiator include acetophenone derivative compounds such as methoxyacetophenone; benzoin Benzoin ether compounds such as propyl ether and benzoin isobutyl ether; ketal derivative compounds such as benzyldimethyl ketal and acetophenone diethyl ketal; phosphine oxide derivative compounds; bis (η5-cyclopentadienyl) titanocene derivative compounds, benzophenone, Michler ketone, chloro Optical labels such as thioxanthone, dodecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, α-hydroxycyclohexyl phenyl ketone, 2-hydroxymethylphenylpropane A dical polymerization initiator is mentioned. These photoinitiators may be used independently and 2 or more types may be used together.

Examples of the thermal polymerization initiator include those that decompose by heat and generate active radicals that initiate polymerization and curing. Specifically, for example, dicumyl peroxide, di-t-butyl peroxide, t-butyl peroxybenzoyl, t-butyl hydroperoxide, benzoyl peroxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, para Menthane hydroperoxide, di-t-butyl peroxide and the like can be mentioned.

The photocurable pressure-sensitive adhesive or thermosetting pressure-sensitive adhesive preferably further contains a radical polymerizable polyfunctional oligomer or monomer. By containing a radically polymerizable polyfunctional oligomer or monomer, photocurability and thermosetting are improved.
The polyfunctional oligomer or monomer preferably has a molecular weight of 10,000 or less, and more preferably has a molecular weight of 5000 or less so that the three-dimensional network of the pressure-sensitive adhesive layer can be efficiently formed by heating or light irradiation. And the number of radically polymerizable unsaturated bonds in the molecule is 2-20.

The polyfunctional oligomer or monomer is, for example, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, or the same methacrylate as described above. And the like. Other examples include 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, commercially available oligoester acrylate, and methacrylates similar to those described above. These polyfunctional oligomers or monomers may be used alone or in combination of two or more.

The pressure-sensitive adhesive layer contains a silicone compound. By containing the silicone compound, even when the pressure-sensitive adhesive tape is subjected to a high-temperature heat treatment step, adhesion enhancement can be prevented by the silicone compound bleed out from the pressure-sensitive adhesive layer.

It does not specifically limit as said silicone compound, For example, Shin-Etsu Chemical Co., Ltd. X-22-164, X-22-164AS, X-22-164A, X-22-164B, X-22-164C, X- Silicone compounds having methacrylic groups at both ends, such as 22-164E, and silicone compounds having methacrylic groups at one end, such as X-22-174DX, X-22-2426, X-22-2475 manufactured by Shin-Etsu Chemical Co., Ltd. And silicone compounds having an acrylic group such as EBECRYL350 and EBECRYL1360 manufactured by Daicel Cytec, silicone compounds having an acrylic group such as AC-SQ TA-100 and AC-SQ SI-20 manufactured by Toagosei, and Toagosei MAC-SQ TM-100, MAC-SQ SI-20, MAC-SQ HD made by the company A conventionally known commercially available silicone compound such as a silicone compound having a methacrylic group such as M can be used.

When the pressure-sensitive adhesive layer contains a photocurable pressure-sensitive adhesive, the silicone compound may be a silicone compound having a functional group capable of crosslinking with the photocurable pressure-sensitive adhesive by irradiation with light (hereinafter referred to as “functional group-containing”). It is also referred to as “silicone compound”. By using such a functional group-containing silicone compound, it is possible to prevent adhesion enhancement of the pressure-sensitive adhesive layer and to prevent the adherend from being contaminated by the bleed-out silicone compound.

As the functional group of the functional group-containing silicone compound, an appropriate one is selected and used according to the pressure-sensitive adhesive contained in the pressure-sensitive adhesive layer. For example, when the pressure-sensitive adhesive is a photo-curable pressure-sensitive adhesive mainly composed of a (meth) acrylic acid alkyl ester-based polymerizable polymer having a radical polymerizable unsaturated bond in the molecule, (meth) acrylic A functional group capable of crosslinking with the group is selected.
The functional group capable of crosslinking with the (meth) acryl group is a functional group having an unsaturated double bond, and specific examples include a vinyl group, a (meth) acryl group, an allyl group, and a maleimide group. .

Although the molecular weight of the said functional group containing silicone compound is not specifically limited, A preferable minimum is 300 and a preferable upper limit is 50000. If the molecular weight is less than 300, the resulting adhesive tape may have insufficient heat resistance, and if it exceeds 50,000, it may be difficult to be dispersed in the adhesive layer. The more preferable lower limit of the molecular weight is 400, the more preferable upper limit is 10,000, the still more preferable lower limit is 500, and the more preferable upper limit is 5000.

The pressure-sensitive adhesive layer is a gas generating agent that generates gas by stimulation, a polyfunctional compound such as an isocyanate compound, a melamine compound, or an epoxy compound, which is blended for the purpose of adjusting cohesive force, and an inorganic filler, if necessary. Further, known additives such as a heat stabilizer, an antioxidant, an antistatic agent, a plasticizer, a resin, a surfactant, and a wax may be contained.

Although the thickness of the said adhesive layer is not specifically limited, A preferable minimum is 20 micrometers and a preferable upper limit is 120 micrometers. When the thickness of the pressure-sensitive adhesive layer is within this range, the pressure-sensitive adhesive tape exhibits a sufficient adhesive force and can be suitably used for various applications. The minimum with more preferable thickness of the said adhesive layer is 35 micrometers, and a more preferable upper limit is 60 micrometers.

The pressure-sensitive adhesive tape of the present invention may be a single-sided pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer only on one side of the substrate, or a double-sided pressure-sensitive adhesive tape having pressure-sensitive adhesive layers on both sides of the substrate.
When the pressure-sensitive adhesive tape of the present invention is a double-sided pressure-sensitive adhesive tape, the pressure-sensitive adhesive layers on both sides may be the same or different.

The anchor layer is disposed between the base material and the pressure-sensitive adhesive layer, and the silicone compound in the pressure-sensitive adhesive layer bleeds out to the interface between the base material and the pressure-sensitive adhesive layer during storage of the pressure-sensitive adhesive tape, It has a role which prevents that the adhesive force of an agent layer and a base material falls and peels.
The anchor layer contains a (meth) acrylic copolymer and a curing agent.

The (meth) acrylic copolymer contained in the anchor layer is a monomer mixture containing a (meth) acrylic acid alkyl ester having 5 to 12 carbon atoms in the alkyl group and a carboxyl group-containing monomer. Polymerized. By containing such a (meth) acrylic copolymer, the anchor layer can exhibit high adhesiveness to the pressure-sensitive adhesive layer and the base material, thereby improving the anchoring force.

Specific examples of the alkyl group having 5 to 12 carbon atoms in the alkyl group include 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, and isononyl (meth) acrylate. Etc. These (meth) acrylic acid alkyl esters may be used alone or in combination of two or more.

The lower limit of the amount of the (meth) acrylic acid alkyl ester having 5 to 12 carbon atoms of the alkyl group in the monomer mixture is 90% by weight, and the upper limit is 99% by weight. When the blending amount of the alkyl group having 5 to 12 carbon atoms in the alkyl group is within this range, it exhibits high adhesion to the pressure-sensitive adhesive layer and the substrate, and anchor strength. Can be improved. A preferable lower limit of the amount of the alkyl group having 5 to 12 carbon atoms in the alkyl group is 91% by weight, and a preferable upper limit is 98% by weight.

Specific examples of the carboxyl group-containing monomer include acrylic acid and methacrylic acid. These carboxyl group-containing monomers may be used alone or in combination of two or more.

The lower limit of the amount of the carboxyl group-containing monomer in the monomer mixture is 1% by weight, and the upper limit is 10% by weight. When the blending amount of the carboxyl group-containing monomer is within this range, the anchor layer exhibits a high cohesive force and can prevent the anchor force from being lowered due to cohesive failure of the anchor layer. The minimum with the preferable compounding quantity of the said carboxyl group-containing monomer is 3 weight%, and a preferable upper limit is 7 weight%.

The monomer mixture may contain a monomer other than the (meth) acrylic acid alkyl ester having 5 to 12 carbon atoms and the carboxyl group-containing monomer. Specifically, for example, hydroxyethyl acrylate, hydroxypropyl methacrylate, glycidyl acrylate, glycidyl methacrylate and the like, and amide group-containing monomers such as acrylamide, 2-methylacrylamide, 2-ethylacrylamide, N-methylolacrylamide and the like are included. May be.

The method for polymerizing the monomer mixture to obtain the (meth) acrylic copolymer is not particularly limited. For example, a conventionally known polymerization method such as a living radical polymerization method or a radical polymerization method can be used.

The anchor layer contains an epoxy compound having a tertiary amine structure and an isocyanate compound as a curing agent. By using these curing agents in combination, the anchor layer can exhibit high heat resistance when subjected to a high-temperature heat treatment process, and the silicone compound migrates to the anchor layer during storage of the adhesive tape, resulting in anchoring power. It is possible to prevent the decrease.

The epoxy compound having a tertiary amine structure particularly improves the heat resistance of the anchor layer, and when the high-temperature heat treatment process is performed with the adhesive tape attached to the adherend, the anchor layer breaks down. Specific examples of the epoxy compound having a tertiary amine structure that has the role of preventing the occurrence of adhesive residue on the adherend include, for example, N, N, N ′, N′-tetraglycidyl-1 , 3-benzenedi (methanamine) and the like.
As such an epoxy compound having a tertiary amine structure, for example, a commercial product such as a trade name “E-5C” manufactured by Soken Chemical Co., Ltd. may be used.

The content of the epoxy compound having the tertiary amine structure in the anchor layer is 0.01 parts by weight with respect to 100 parts by weight of the (meth) acrylic copolymer, and 1.0 parts by weight with respect to the upper limit. . When the content of the epoxy compound having a tertiary amine structure is within this range, the anchor layer can exhibit high heat resistance even when subjected to a high-temperature heat treatment step. The minimum with preferable content of the epoxy-type compound which has the said tertiary amine structure is 0.1 weight part, and a preferable upper limit is 0.7 weight part.

The said isocyanate type compound has a role which prevents that a silicone compound transfers to an anchor layer at the time of storage of an adhesive tape, and an anchor force falls.
Specific examples of the isocyanate compound include trimethylolpropane / tolylene diisocyanate trimer adduct and the like.
As such an isocyanate compound, for example, commercially available products such as Coronate L, Coronate HL, and Coronate HX can be used.

The content of the isocyanate compound in the anchor layer is such that the lower limit with respect to 100 parts by weight of the (meth) acrylic copolymer is 1 part by weight and the upper limit is 10 parts by weight. When the content of the isocyanate compound is in this range, it is possible to prevent the silicone compound from moving to the anchor layer during storage of the adhesive tape and lowering the anchor force. The minimum with preferable content of the said isocyanate type compound is 3 weight part, and a preferable upper limit is 7 weight part.

The anchor layer may contain a known additive such as an inorganic filler, a heat stabilizer, an antioxidant, an antistatic agent, a plasticizer, a resin, a surfactant, or a wax, if necessary.

Although the thickness of the said anchor layer is not specifically limited, A preferable minimum is 1 micrometer and a preferable upper limit is 20 micrometers. When the thickness of the anchor layer is within this range, the pressure-sensitive adhesive layer can reliably improve the anchoring force with the base material. A more preferable lower limit of the thickness of the anchor layer is 3 μm, and a more preferable upper limit is 10 μm.

Although the method of manufacturing the adhesive tape of this invention is not specifically limited, For example, the following methods etc. can be used.
First, apply the resin composition solution, which is the raw material of the anchor layer, to the treated surface of the base material that has been subjected to corona treatment on one side using a doctor knife, etc., and dry the coating solution to form the anchor layer To do. On the other hand, a resin composition solution that is a raw material for the pressure-sensitive adhesive layer is applied to a release surface of a release film that has been subjected to a release treatment on one side using a doctor knife or the like, and the coating solution is dried. An adhesive layer is formed. Next, the anchor layer of the base material provided with the anchor layer and the adhesive layer of the release film provided with the adhesive layer are bonded together, and the anchor layer and the adhesive layer are laminated in this order on the surface of the base material, An adhesive tape whose surface is protected with a release film can be obtained.

The use of the pressure-sensitive adhesive tape of the present invention is not particularly limited, but the adhesion is small even when it is subjected to a high-temperature heat treatment step, and the decrease in anchoring force between the pressure-sensitive adhesive layer and the substrate is small during storage. It can be used particularly suitably for applications in which a high-temperature heat treatment step is performed with the adhesive tape attached, and then the adhesive tape is peeled off.

ADVANTAGE OF THE INVENTION According to this invention, even if it uses for a high-temperature heat treatment process, there is little adhesion enhancement and it can provide the adhesive tape with a little fall of the anchor force between an adhesive layer and a base material at the time of storage.

Hereinafter, embodiments of the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

Example 1
(1) Preparation of resin composition for pressure-sensitive adhesive layer A reactor equipped with a thermometer, a stirrer, and a cooling tube was prepared. In this reactor, 94 parts by weight of 2-ethylhexyl acrylate, 1 part by weight of acrylic acid, 2- After adding 5 parts by weight of hydroxyethyl acrylate, 0.01 part by weight of lauryl mercaptan and 80 parts by weight of ethyl acetate, the reactor was heated to start refluxing. Subsequently, 0.01 parts by weight of 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane was added as a polymerization initiator in the reactor, and polymerization was started under reflux. It was. Next, after 1 hour and 2 hours from the start of polymerization, 0.01 parts by weight of 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane was added, and the polymerization was started. 4 hours later, 0.05 part by weight of t-hexylperoxypivalate was added to continue the polymerization reaction. And 8 hours after the start of polymerization, an acrylic copolymer having a solid content of 55% by weight and a weight average molecular weight of 600,000 was obtained.

The resin solid content of 100 parts by weight of the ethyl acetate solution containing the acrylic copolymer thus obtained is reacted by adding 3.5 parts by weight of 2-isocyanatoethyl methacrylate, and further the resin of the ethyl acetate solution after the reaction. 1 part by weight of photopolymerization initiator (Esacure One, manufactured by Nippon Shibel Hegner), silicone compound having a (meth) acrylic group (Daicel Cytec, EBECRYL 350, acrylic equivalent is 2) per 100 parts by weight of solid content Then, 0.5 part by weight of a polyisocyanate-based crosslinking agent (Coronate L45, manufactured by Nippon Polyurethane Industry Co., Ltd.) was mixed to prepare an ethyl acetate solution of a resin composition for an adhesive layer.

(2) Preparation of resin composition for anchor layer A reactor equipped with a thermometer, a stirrer, and a cooling tube was prepared. In this reactor, 96 parts by weight of n-butylbutyl acrylate, 4 parts by weight of acrylic acid, lauryl mercaptan After 0.01 parts by weight and 80 parts by weight of ethyl acetate were added, the reactor was heated to start refluxing. Subsequently, 0.01 parts by weight of 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane was added as a polymerization initiator in the reactor, and polymerization was started under reflux. It was. Next, after 1 hour and 2 hours from the start of polymerization, 0.01 parts by weight of 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane was added, and the polymerization was started. 4 hours later, 0.05 part by weight of t-hexylperoxypivalate was added to continue the polymerization reaction. And 8 hours after the start of polymerization, an acrylic copolymer having a solid content of 42% by weight and a weight average molecular weight of 500,000 was obtained.

0.1 parts by weight of glycerin diglycidyl ether (E-5XM, manufactured by Soken Chemical Co., Ltd.) as a curing agent with respect to 100 parts by weight of the resin solid content of the ethyl acetate solution containing the obtained acrylic copolymer, 5 parts by weight of Coronate L (manufactured by Nippon Polyurethane Industry Co., Ltd.) were mixed to prepare an ethyl acetate solution of the anchor layer resin composition.

(3) Manufacture of adhesive tape The ethyl acetate solution of the obtained resin composition for anchor layer was subjected to corona treatment on one side and the thickness of the dried film on the corona treatment surface of a transparent polyethylene naphthalate film having a thickness of 50 μm. Was applied with a doctor knife so as to be 5 μm, and heated at 110 ° C. for 5 minutes to dry the coating solution to form an anchor layer. Thereafter, the film was allowed to stand at 40 ° C. for 3 days for curing.

The obtained ethyl acetate solution of the resin composition for the pressure-sensitive adhesive layer was coated on a polyethylene terephthalate film whose surface was subjected to a release treatment with a doctor knife so that the thickness of the dried film was 35 μm, and 110 ° C. The adhesive layer was obtained by heating for 5 minutes to evaporate the solvent and drying the coating solution. The pressure-sensitive adhesive layer after drying showed adhesiveness in a dry state. Thereafter, the film was allowed to stand at 40 ° C. for 3 days for curing.

Next, an anchor layer of a polyethylene naphthalate film subjected to corona treatment provided with an anchor layer and an adhesive layer of a polyethylene terephthalate film subjected to release treatment provided with an adhesive layer were bonded together. As a result, the anchor layer and the pressure-sensitive adhesive layer are laminated in this order on the surface of the base material made of a polyethylene naphthalate film subjected to corona treatment, and the pressure-sensitive adhesive tape whose surface is protected by the release-treated polyethylene terephthalate film Obtained.

In addition, the adhesive tape which formed only the anchor layer on the base material separately was prepared, and it cut | judged in the plane rectangular shape of 50 mm x 100 mm, and produced the test piece. The test piece was immersed in ethyl acetate at 23 ° C. for 24 hours, then taken out from the ethyl acetate and dried at 110 ° C. for 1 hour. The weight of the test piece after drying was measured, and the gel fraction was calculated using the following formula (1).
Gel fraction (% by weight) = 100 × (W2-W0) / (W1-W0) (1)
(W0: weight of substrate, W1: weight of test piece before immersion, W2: weight of test piece after immersion and drying)

(Examples 2-3, Comparative Examples 1-3)
A pressure-sensitive adhesive tape was obtained in the same manner as in Example 1 except that the type and blending amount of the curing agent in the anchor layer were as shown in Table 1.

(Evaluation)
About the adhesive tape obtained by the Example and the comparative example, it evaluated by the following method.
The results are shown in Table 1.

(1) Measurement of anchor force About the obtained adhesive tape, it cut out to the test piece of 100 mm x 25 mm. Next, the 50 μm peeled PET separator is peeled off, and the 2 kg roller is reciprocated once at a speed of 300 mm / min, and bonded to the double-sided tape 100 mm × 100 mm of the adherend, and the atmosphere is 20 ° C. and the relative humidity is 50%. A sample was obtained after standing for more than a minute. About the obtained sample, it peeled at an angle of 180 degrees based on JIS Z-0237 using a tensile tester (manufactured by Shimadzu Corporation, Autograph), and the anchor force between the adhesive layer and the substrate was It was measured.
The anchoring force is as follows: 1) After irradiating ultraviolet rays at an intensity of 100 mW / cm ² for 30 seconds from the substrate side of the adhesive tape (UV irradiation), 2) Ultra high pressure from the substrate side of the adhesive tape Irradiation with ultraviolet rays at a strength of 100 mW / cm ² using a mercury lamp for 30 seconds, followed by heat treatment at 240 ° C. for 1 hour (UV irradiation + heat treatment), and 3) conditions of the adhesive tape at 40 ° C. and 50 RH% After 14 days of storage, the substrate was irradiated with ultraviolet rays at an intensity of 100 mW / cm ² for 30 seconds from the substrate side of the adhesive tape, and then heat-treated at 240 ° C. for 1 hour (long-term storage + UV irradiation) + Heat treatment).

(2) Heat resistance test The obtained adhesive tape was affixed to a SUS board as an adherend, and heat-treated at 240 ° C for 1 hour in that state. After the heat treatment, the adhesive tape was peeled from the adherend after irradiating ultraviolet rays with an intensity of 100 mW / cm ² for 30 seconds from the substrate side of the adhesive tape using an ultra-high pressure mercury lamp.
The surface of the adherend after peeling off the adhesive tape was visually observed and evaluated according to the following criteria. Evaluation of heat resistance was performed on the adhesive tape immediately after production (initial stage) and after storage for 14 days (after long-term storage) under the conditions of 40 ° C. and 50 RH%.
○: No adhesive residue was observed on the surface of the adherend.
X: Adhesive residue was observed on the surface of the adherend.

ADVANTAGE OF THE INVENTION According to this invention, even if it uses for a high-temperature heat treatment process, there is little adhesion enhancement and it can provide the adhesive tape with a little fall of the anchor force between an adhesive layer and a base material at the time of storage.

Claims (3)

At least a pressure-sensitive adhesive tape having a structure in which a base material, an anchor layer and a pressure-sensitive adhesive layer are laminated in this order,
The pressure-sensitive adhesive layer contains a silicone compound,
The anchor layer is a polymerization of a monomer mixture containing 90 to 99% by weight of an alkyl (meth) acrylic acid alkyl ester having 5 to 12 carbon atoms and 1.0 to 10% by weight of a carboxyl group-containing monomer. 0.01 to 1.0 part by weight of an epoxy compound having a tertiary amine structure as a curing agent and 1 to 10 parts by weight of an isocyanate compound with respect to 100 parts by weight of the (meth) acrylic copolymer obtained by A pressure-sensitive adhesive tape comprising: The pressure-sensitive adhesive tape according to claim 1, wherein the anchor layer has a thickness of 1 to 20 μm. The pressure-sensitive adhesive layer contains a photocurable pressure-sensitive adhesive and a silicone compound having a molecular weight of 300 to 50,000 having a functional group capable of crosslinking with the light-curable pressure-sensitive adhesive when irradiated with light. The adhesive tape of 1 or 2.