JP6126430B2 - Laminate - Google Patents

Description

  The present invention relates to a laminate including a substrate and an adhesive layer laminated on one main surface of the substrate.

  Laminates having an adhesive layer are widely used in the display device manufacturing field, the semiconductor-related member manufacturing field, the electric / electronic component manufacturing field, and the like. In the field of manufacturing display devices, a specific example of such a laminate includes a laminate of a glass substrate (mother glass) and an adhesive layer (also referred to as “GP laminate” in the present specification). A cover glass or the like is laminated as an adherend on the surface on the pressure-sensitive adhesive layer side of the GP laminate. In the field of manufacturing semiconductor-related members, a semiconductor processing tape is given as a specific example of such a laminate. In use, a semiconductor wafer or the like is laminated as an adherend on the surface of the laminate on the pressure-sensitive adhesive layer side. Processing is applied. In the field of manufacturing electrical / electronic components, a specific example of such a laminate is a laminate of a flexible printed circuit board and an adhesive layer (also referred to as “FP laminate” in this specification). A casing or the like is laminated as an adherend on the surface of the FP laminate on the pressure-sensitive adhesive layer side.

  Such a laminate is a high temperature environment (in this specification, “high temperature environment” means an environment having a temperature higher than room temperature (23 ° C.) in the state as it is or in a state where the adherend is laminated. Yes, it may be placed underneath. If it demonstrates concretely using said example, when a transparent conductive film is formed on a glass surface, a GP laminated body may raise temperature. The semiconductor processing tape may be heated to fix it on a dicing table or the like. The FP laminate may be placed in a high temperature environment by the operation of other parts (for example, a motor) in the casing.

  When placed in such a high-temperature environment, outgas (a gas component released from the pressure-sensitive adhesive layer of the laminate during storage and / or use of the laminate) from the pressure-sensitive adhesive layer included in the laminate is generated. It may occur that the material constituting the pressure-sensitive adhesive layer or the material constituting the base material deteriorates or the generated outgas contaminates members around the laminate including the adherend. .

In order to solve such a problem, Patent Document 1 discloses the following a to e five components:
a) It consists of 70 to 100% by weight of a (meth) acrylic acid alkyl ester having 2 to 14 carbon atoms in the alkyl group and 30 to 0% by weight of a monoethylenically unsaturated monomer copolymerizable therewith. 100 parts by weight of monomer b) 0.1 to 5 parts by weight of radical chain inhibitor c) 0.02 to 5 parts by weight of polyfunctional (meth) acrylate as a cross-linking agent d) Photopolymerization initiator 0.005 to 1 E) a pressure-sensitive adhesive layer comprising a photopolymer of a composition containing 0.01 to 10 parts by weight of a silane coupling agent, having a haze value of 1% or less and a total light transmittance of 90% or more. Yes.

JP 2009-102647 A

However, in the pressure-sensitive adhesive layer of Patent Document 1, generation of outgas cannot be sufficiently suppressed under severe use conditions of 200 ° C. or higher, and surface treatment on the exposed surface side of the adherend in such an environment. Could not be suitably performed.
By the way, in the manufacturing process and the use process, the laminated body may be required to be peeled off from the adherend or laminated (attached) to the adherend again. Moreover, depending on a use, the base material and adhesive layer which comprise this laminated body may be finally peeled. In these cases, when the pressure-sensitive adhesive layer is peeled off from the substrate or the adherend, the possibility that the constituent material of the pressure-sensitive adhesive layer remains on the substrate or the adherend is reduced. It is preferable that the removability is excellent. In particular, when the adhesive layer undergoes a thermal history that is placed in a high-temperature environment, the adhesion to the substrate or adherend may increase due to physical or chemical reasons. For this reason, it is preferable that the pressure-sensitive adhesive layer has excellent removability after being subjected to such a thermal history.

  The present invention is less likely to generate outgas even when placed in a high temperature environment, and does not contaminate the adherend even after undergoing a heat history placed in a high temperature environment, and has excellent removability. It aims at providing the laminated body provided with the adhesive layer.

  The present invention provided to achieve the above object is, firstly, a laminate comprising a base material and a pressure-sensitive adhesive layer laminated on one surface of the base material, the pressure-sensitive adhesive. The layer is formed from a silicone-based pressure-sensitive adhesive composition, and the silicone-based pressure-sensitive adhesive composition includes an addition-type organopolysiloxane having a siloxane bond as a main skeleton and an alkenyl group as a constituent component. A platinum catalyst of 0.01 parts by mass or more and 3 parts by mass or less per 100 parts by mass of the silicone rubber, and a silicone resin of 15 parts by mass or more and 100 parts by mass or less per 100 parts by mass of the silicone rubber, and the pressure-sensitive adhesive layer In an air atmosphere at a rate of 5 ° C./min from 23 ° C. to 200 ° C., the mass reduction rate at 200 ° C. with respect to the mass at 40 ° C. is 0.20% by mass or less. Providing a laminate wherein there (invention 1).

  Since such a laminate has a low mass reduction rate of the pressure-sensitive adhesive layer as described above, the amount of outgas can be stably reduced even when the laminate according to this embodiment is placed in a high-temperature environment. Become. In addition, since the pressure-sensitive adhesive layer is formed from the above-mentioned silicone-based pressure-sensitive adhesive composition, after pasting the pressure-sensitive adhesive layer of the above laminate to the adherend, even after heat treatment, when peeling thereafter, The pressure-sensitive adhesive layer does not cause cohesive failure, the pressure-sensitive adhesive layer remains only on the substrate or the adherend, and the pressure-sensitive adhesive layer does not remain on the other side.

  In the above invention (Invention 1), the pressure-sensitive adhesive layer is a step of placing in an air atmosphere at a temperature of 200 ° C. or higher for 60 minutes or more in a state where the pressure-sensitive adhesive composition layer composed of the silicone-based pressure-sensitive adhesive composition is exposed. It is preferable that it has passed through the annealing process which contains (Invention 2).

  In the said invention (invention 1 and 2), it is preferable that the said adhesive layer is heat-processed in the state by which the to-be-adhered body was laminated | stacked on the surface at the side of the said adhesive layer of the said laminated body (invention). 3).

  In the said invention (invention 3), it is preferable that the process which the said adhesive layer is heated is a surface treatment with respect to the surface on the opposite side to the surface which opposes the said adhesive layer of the said to-be-adhered body (invention 4).

  In the said invention (invention 4), it is preferable that the said surface treatment includes the process which forms a transparent conductive film (invention 5).

  The laminate according to the present invention hardly generates outgas even when placed in a high temperature environment, and also has excellent removability. Thereby, while improving the work precision to the to-be-adhered body under high temperature, the adhesion etc. of the adhesive layer to the to-be-adhered body after an operation | work can be prevented.

Hereinafter, embodiments of the present invention will be described.
1. Laminated body The laminated body which concerns on one Embodiment of this invention is equipped with a base material and the adhesive layer laminated | stacked on one surface of this base material.

(1) Base Material The composition and structure of the base material of the laminate according to the present embodiment are not particularly limited as long as the base material has heat resistance and a pressure-sensitive adhesive layer described later can be properly adhered.

As a specific example of the material constituting the surface facing the pressure-sensitive adhesive layer in the substrate, a glass substrate used in a display device can be mentioned.
In the case where the substrate is a glass substrate, the specific type of material constituting the glass substrate is not particularly limited. For example, chemically tempered glass, alkali-free glass, quartz glass, soda lime glass, barium Examples include strontium-containing glass, aluminosilicate glass, lead glass, borosilicate glass, and barium borosilicate glass. Although the thickness of a glass substrate is not specifically limited, Usually, it is 0.1-5 mm, Preferably it is 0.2-2 mm.

  The substrate may be made of a heat resistant plastic material. When the substrate is made of a heat-resistant plastic film, specific examples thereof include polyimide film, polyamide film, polyamideimide film, polysulfone film, polyphenylene sulfide film, polyether ether ketone film, polyarylate film, polycarbonate film, and liquid crystal Examples thereof include polymer films, polyethylene naphthalate films; and laminates of two or more of these. The plastic film may be uniaxially stretched or biaxially stretched.

(2) Adhesive layer (2-1) Composition The adhesive layer with which the laminated body which concerns on this embodiment is provided is formed from the silicone type adhesive composition containing the component demonstrated below. Since the silicone pressure-sensitive adhesive composition is superior in heat resistance compared to other types of pressure-sensitive adhesive compositions, for example, acrylic pressure-sensitive adhesive compositions, the pressure-sensitive adhesive layer formed from the silicone-based pressure-sensitive adhesive composition is heated. It is difficult to cause problems such as floating, peeling and foaming.

  The silicone pressure-sensitive adhesive composition according to this embodiment contains a silicone rubber containing an addition type organopolysiloxane having a siloxane bond as a main skeleton and an alkenyl group as a constituent component. By containing such a silicone rubber, it becomes possible to relatively reduce the peeling force of the pressure-sensitive adhesive layer. Therefore, the pressure-sensitive adhesive layer can be easily peeled off from the base material or the adherend, and the material constituting the pressure-sensitive adhesive layer based on the cohesive failure of the pressure-sensitive adhesive layer is applied to the base material or the adherend. The remaining amount can be extremely small. Therefore, the pressure-sensitive adhesive layer formed from the silicone-based pressure-sensitive adhesive composition according to this embodiment containing such a silicone rubber can be excellent in removability.

  Specific examples of the alkenyl group include an allyl group, a propenyl group, a butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, and an octenyl group. Furthermore, you may have the organic group which does not have addition reactivity. Specific examples of such an organic group include alkyl groups such as methyl group, ethyl group, and propyl group, and aryl groups such as phenyl group.

  The degree of polymerization of the organopolysiloxane contained in the silicone rubber is not particularly limited, but is usually 500 or more and 10,000 or less, more preferably 2000 or more and 8,000 or less.

  The silicone-based pressure-sensitive adhesive composition according to this embodiment contains a platinum catalyst. This platinum catalyst has a function of initiating the addition reaction of the alkenyl group and a function of promoting the addition reaction. Examples of the platinum catalyst include platinum black, secondary platinum chloride, chloroplatinic acid, a reaction product of chloroplatinic acid and a monohydric alcohol, a complex of chloroplatinic acid and an olefin, platinum bisacetoacetate, etc. Can do. Content of the platinum catalyst in the silicone type adhesive composition which concerns on this embodiment is 0.01 mass part or more and 3 mass parts or less per 100 mass parts of silicone rubber. By setting it as this range, the function of a platinum catalyst is exhibited stably. From the viewpoint of more stably exerting the function of the platinum catalyst, the content of the platinum catalyst in the silicone-based pressure-sensitive adhesive composition is 0.05 parts by mass or more and 2.00 parts by mass or less per 100 parts by mass of the silicone rubber. It is more preferable that it is 0.10 parts by mass or more and 1.00 parts by mass or less.

  The silicone-based pressure-sensitive adhesive composition according to this embodiment contains a silicone resin, that is, a branched organopolysiloxane in the molecule. By containing such a silicone resin, the adhesiveness of the adhesive layer to the substrate or adherend can be increased. From the viewpoint of appropriately setting the degree of adhesiveness and reducing the possibility of outgassing, the content of the silicone resin in the silicone-based adhesive composition according to this embodiment is about 100 parts by mass of silicone rubber. 10 parts by mass or more and 100 parts by mass or less. The silicone resin content in the silicone-based pressure-sensitive adhesive composition is silicone rubber from the viewpoint of stably achieving the above-mentioned adhesiveness appropriately and further reducing the possibility of outgas generation. It is preferable to set it as 15 to 75 mass parts per 100 mass parts, and it is more preferable to set it as 20 to 50 mass parts.

  The silicone-based pressure-sensitive adhesive composition according to this embodiment can contain various components as long as the pressure-sensitive adhesive layer can exhibit a desired function. For example, crosslinking agents having hydrosilyl groups; crosslinking accelerators; coloring materials such as dyes and pigments; antioxidants such as anilides and phenols; ultraviolet absorbers such as benzophenones and benzotriazoles; talc, titanium dioxide, silica And filler components such as starch, plasticizers, antioxidants, light stabilizers, dispersants, leveling agents and the like. However, these components are preferably those which do not easily generate outgas. Moreover, when the silicone type adhesive composition which concerns on this embodiment contains the crosslinking agent which has a hydrosilyl group, the content is 1.0 mass part or more and 10.0 mass parts or less per 100 mass parts of silicone rubbers. It is preferable that

  Here, the pressure-sensitive adhesive layer according to this embodiment is obtained by forming the pressure-sensitive adhesive composition layer by applying and drying the above-described silicone-based pressure-sensitive adhesive composition, and subjecting the layer to annealing treatment. Details will be described later.

(2-2) Mass reduction resistance The pressure-sensitive adhesive layer according to this embodiment has a mass at 200 ° C. relative to the mass at 40 ° C. when heated at 5 ° C./min from 23 ° C. to 200 ° C. in an air atmosphere. The reduction rate (also referred to as “mass reduction rate” in this specification) is 0.20 mass% or less. That is, the pressure-sensitive adhesive layer according to this embodiment has excellent mass reduction resistance.

  Since the pressure-sensitive adhesive layer has excellent mass reduction resistance, the amount of outgas can be stably reduced even when the laminate according to this embodiment is placed in a high temperature environment. From the viewpoint of more stably reducing the amount of outgas, the mass reduction rate of the pressure-sensitive adhesive layer is preferably 0.01% by mass or less, and the highest temperature reached when the pressure-sensitive adhesive layer is heated (in the above case) It is more preferable that the mass reduction rate of the pressure-sensitive adhesive layer when the temperature is 250 ° C. is 0.5% by mass or less, and the mass of the pressure-sensitive adhesive layer when the maximum temperature reached is 300 ° C. The reduction rate is particularly preferably 1.0% by mass or less.

(2-3) Removability The pressure-sensitive adhesive layer of the laminate according to this embodiment is excellent in removability for a substrate or an adherend. Here, in this specification, “excellent in removability” means that the adhesive layer of the laminate according to this embodiment is pasted on the adherend, and then peeled off even after heat treatment. This means that the pressure-sensitive adhesive layer does not cause cohesive failure, the pressure-sensitive adhesive layer remains only on the substrate or the adherend, and the pressure-sensitive adhesive layer does not remain on the other side. When the pressure-sensitive adhesive layer of the laminate according to this embodiment is excellent in removability, after performing a treatment such as heating on the laminate structure composed of the laminate and adherend according to this embodiment, When the treated adherend is peeled from the laminate according to the present embodiment and subjected to another process, a problem that the adhesive remains on the treated adherence hardly occurs. Moreover, since it becomes possible to re-paste in the sticking operation of the step of bonding the laminate and the adherend according to the present embodiment (also referred to as "sticking step" in this specification), the work load is reduced, Workability of the attaching process is improved. Furthermore, since re-sticking becomes possible, the incidence rate of defective products decreases. Therefore, it is expected that the manufacturing cost of the product including the laminate according to the present embodiment is reduced. In addition, the adhesive layer remains on the substrate when a process such as peeling the substrate is performed on the laminated structure obtained by bonding the laminate and the adherend according to the present embodiment. Since it is difficult to wear, it is expected that the substrate can be easily reused (for example, it is difficult to increase the load of the cleaning process).

  The pressure-sensitive adhesive layer of the laminate according to this embodiment was placed in a high-temperature environment in the state of a laminated structure obtained by bonding the laminate according to this embodiment and the adherend. Even if it is a case, it is preferable to have the excellent removability with respect to a base material or a to-be-adhered body. In this regard, the pressure-sensitive adhesive layer according to the present embodiment has a ratio of pressure-sensitive adhesive strength to the pressure-sensitive adhesive composition layer that has not been annealed (the measurement method will be described in detail in the examples for any pressure-sensitive adhesive strength). 50% or more and 200% or less is preferable.

(2-4) Thickness The thickness of the pressure-sensitive adhesive layer is not particularly limited. When the pressure-sensitive adhesive layer is excessively thin, there is a possibility that it is difficult to obtain the adhesiveness to the substrate or adherend to the required level. From the viewpoint of easily obtaining this appropriate level of tackiness, the thickness of the pressure-sensitive adhesive layer is preferably 2 μm or more, more preferably 5 μm or more, and particularly preferably 10 μm or more. On the other hand, the upper limit of the thickness of the pressure-sensitive adhesive layer should be appropriately set according to its use, and is usually 200 μm or less, preferably 100 μm or less, and more preferably 50 μm or less.

2. Manufacturing method of laminated body The manufacturing method of the laminated body which concerns on this embodiment is not specifically limited. As an example, as described below, first, an adhesive sheet is prepared, and the laminate according to the present embodiment is manufactured using the adhesive sheet.

(1) Adhesive Sheet The adhesive sheet according to the present embodiment includes two release sheets, and an adhesive composition layer sandwiched between the two release sheets so as to be in contact with the release surfaces of the two release sheets. Consists of Such an adhesive sheet can be produced by the following method.

  First, the silicone type adhesive composition which concerns on this embodiment, or the coating liquid formed by adding a solvent to this is prepared. When using the solvent, the type and solid content concentration of the coating solution may be appropriately set in consideration of the composition of the silicone-based pressure-sensitive adhesive composition, the coating conditions, the thickness of the target pressure-sensitive adhesive layer, and the like. Examples of the solvent include toluene, methyl ethyl ketone, ethyl acetate, and the like, and the solid content concentration is in the range of about 10 mass% to about 40 mass%.

  Next, two release sheets are prepared. As the release sheet, for example, polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polyethylene naphthalate film, polybutylene terephthalate film, Polyurethane film, ethylene vinyl acetate film, ionomer resin film, ethylene / (meth) acrylic acid copolymer film, ethylene / (meth) acrylic acid ester copolymer film, polystyrene film, polycarbonate film, polyimide film, fluororesin film, etc. Is used. These crosslinked films are also used. Furthermore, these laminated films may be sufficient.

  The release surface of the release sheet (particularly the surface in contact with the pressure-sensitive adhesive composition layer) is preferably subjected to a release treatment. In addition, the release surface of the release sheet in this specification refers to a surface having peelability in the release sheet, and includes both a surface that has been subjected to a release treatment and a surface that exhibits peelability without being subjected to a release treatment. .

Examples of the release agent used for the release treatment include alkyd, silicone, fluorine, unsaturated polyester, polyolefin, and wax release agents. Since the coating liquid contains the silicone-based pressure-sensitive adhesive composition, the release treatment is preferably a fluorine-based release treatment. When the fluorine-based release treatment is performed by applying a fluorine-based release agent (for example, silicone fluoride), the application amount of the release agent is not limited and is usually 0.02 to 2.0 g / cm. ³ , preferably 0.2 to 1.0 g / cm ³ .

  From the standpoint of preventing poor release of the pressure-sensitive adhesive composition layer, the two release sheets are of different types, so that a predetermined difference occurs in the release force of the release sheets, and one release sheet is heavyly peeled off. It is preferable to use a mold release sheet and the other release sheet to be a light release type release sheet. The peeling force can be appropriately adjusted depending on the composition of the release agent layer, the degree of crosslinking, the film thickness, and the like.

  Although there is no restriction | limiting in particular about the thickness of a peeling sheet, Usually, it is about 20-150 micrometers.

  The above-mentioned coating liquid is applied to the release surface of one prepared release sheet, and after a drying treatment (may be heated) is performed to form a coating layer, the other release sheet is peeled off from the coating layer. Overlapping surfaces. If a curing period is required, a curing period is provided. If the curing period is not necessary, the coating layer becomes the pressure-sensitive adhesive composition layer as it is. Thereby, the adhesive sheet which concerns on this embodiment is obtained. In addition, when two release sheets consist of a heavy release type release sheet and a light release type release sheet, the release sheet to which the coating liquid is applied is a heavy release type release sheet. It is preferable from the viewpoint of facilitating or stabilizing the quality of the obtained pressure-sensitive adhesive sheet.

As a method for applying the coating liquid, for example, a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, a gravure coating method, or the like can be used.
As a specific example of the conditions for the drying treatment, it may be placed in an environment at a temperature of about 80 ° C. to about 140 ° C. for about 30 seconds to 4 minutes.

(2) Laminate A pressure-sensitive adhesive composition by peeling off one release sheet of the above-mentioned pressure-sensitive adhesive sheet (when the type of release sheet is different, it is preferably a release sheet corresponding to a light-release type release sheet). The surface of the layer is exposed and the surface is laminated on one surface of the substrate. Subsequently, the release sheet to be adhered to the pressure-sensitive adhesive composition layer (when the type of release sheet is different, it is preferably a release sheet corresponding to a heavy release type release sheet) is peeled from the pressure-sensitive adhesive composition layer. And the laminated body provided with the base material and the adhesive composition layer is obtained. Hereinafter, this laminate is also referred to as a “first laminate”.

(3) Annealing treatment The first laminated body is subjected to the following annealing treatment to give the pressure-sensitive adhesive layer the aforementioned mass reduction resistance, and the first laminated body is laminated according to the present embodiment. Let it be the body. In the following description, the case where a base material consists of a glass substrate is taken as a specific example.

  In the annealing treatment, the first laminate is heated to remove volatile components remaining inside the adhesive layer of the laminate from the adhesive composition layer. In a specific embodiment, the annealing treatment includes a step of placing the first laminate in an environment at a temperature of 200 ° C. or higher for 60 minutes or more with the surface of the pressure-sensitive adhesive composition layer exposed. By setting the temperature in this annealing process (also referred to as “annealing temperature” in this specification) to 200 ° C. or higher, the pressure-sensitive adhesive layer of the laminate obtained through the annealing process has the above-described mass reduction resistance. Can be realized stably. From the viewpoint of more stably realizing that the pressure-sensitive adhesive layer has the above-described mass reduction resistance, the annealing temperature is preferably 220 ° C. or higher, and more preferably 240 ° C. or higher. The upper limit of the annealing temperature is not set from the viewpoint of imparting mass reduction resistance to the pressure-sensitive adhesive layer. When the annealing temperature is excessively high, there is a risk that defects due to thermal deterioration of the pressure-sensitive adhesive layer or the base material may occur. Therefore, the annealing temperature is preferably 350 ° C. or less, and preferably 300 ° C. or less. More preferably. The cooling from the annealing temperature to room temperature in the annealing process is not particularly limited, and may be performed in accordance with a common method such as cooling in an air atmosphere at room temperature.

  The release surface of the release sheet is applied to the adhesive layer side surface of the laminate obtained through the annealing treatment, and this adhesive layer side surface is protected until it is applied to the adherend. May be. As described above, the release surface of the release sheet in this case is preferably a surface that has been subjected to a release treatment other than silicone-based, specifically, a fluorine-based release treatment.

3. The adherend of the laminate according to the present embodiment is not particularly limited. Semiconductor-related members such as semiconductor wafers and packages as adherends; display device-related members such as cover glasses, protective sheets, polarizing films, and retardation films; electrical and electronic components such as circuit boards and housings made of glass epoxy materials A member etc. are illustrated. A plurality of adherends may be arranged on the laminate according to the present embodiment. In this case, the adherends close to each other may be separated in the in-plane direction of the surface of the pressure-sensitive adhesive layer of the laminate according to the present embodiment.

  Specific examples of the adherend include a glass substrate and a heat-resistant plastic film, as in the specific example of the substrate. In the case where the adherend is a glass substrate, the material of the glass substrate forming the adherend is not particularly limited. For example, chemically strengthened glass, alkali-free glass, quartz glass, soda lime glass, barium strontium Examples thereof include glass, aluminosilicate glass, lead glass, borosilicate glass, and barium borosilicate glass. The thickness of the glass substrate is not limited as in the case of the base material, and is usually 0.1 to 5 mm, preferably 0.2 to 2 mm.

  In a state where the adherend is laminated on the surface on the pressure-sensitive adhesive layer side of the laminate according to the present embodiment, a treatment for heating the pressure-sensitive adhesive layer (also referred to as “heating treatment” in this specification) is performed. Moreover, since the material which comprises the adhesive layer of the laminated body which concerns on this embodiment has the above-mentioned mass reduction resistance, the outgas amount from the laminated body is reduced. Therefore, by using the laminate according to the present embodiment, it is possible to suppress the adherend from being contaminated with outgas, and the components existing around the adherend from being contaminated with outgas. .

  Here, the specific content of the above-described heat treatment is not particularly limited, and the purpose may be to heat at least one of the laminate and the adherend according to the present embodiment, or according to the present embodiment. The pressure-sensitive adhesive layer may be heated as a result of performing a treatment not intended for heating on at least one of the laminate and the adherend. Furthermore, the atmospheric temperature of the laminate and adherend according to this embodiment increases as a result of the operation of the laminate and adherend in the vicinity of this embodiment, and the pressure-sensitive adhesive layer is heated. May be the case.

  As an example of the above heat treatment, there is a surface treatment using a specific example of forming a film-like body on one surface of the adherend and removing the adherend or the formed film-like body. More specific examples of surface treatment include tin-doped indium oxide (ITO), fluorine-doped tin oxide (FTO), zinc oxide (ZnO), and zinc oxide-based materials in which aluminum or gallium is added to zinc oxide by vapor deposition or sputtering. The formation of a transparent conductive film such as (AZO, GZO) is exemplified.

  The object on which the transparent conductive film is formed may be a substrate or an adherend. If the object on which the transparent conductive film is formed is a glass substrate, and the formation of the transparent conductive film is performed in the manufacturing process of the display device, this glass is used from the viewpoint of increasing optical characteristics, particularly transmittance. The thickness of the substrate is usually 5 mm or less. Therefore, when the step of forming the transparent conductive film is performed on one main surface of the glass substrate, the glass substrate (which may be a base material or an adherend) is formed along with the formation of the transparent conductive film. May be heated, and the pressure-sensitive adhesive layer disposed so as to be in contact therewith may be heated. When the transparent conductive film is formed by sputtering, heating of the pressure-sensitive adhesive layer is likely to occur, and in particular, in the case of a configuration in which a substance having high kinetic energy generated by sputtering can reach the pressure-sensitive adhesive layer directly. Tends to be prominent. Even in such a case, when the laminated body according to the present embodiment is used, the formed transparent conductive film is suppressed from being contaminated by outgas.

  The subsequent handling of the glass substrate on which the transparent conductive film is formed is not particularly limited. When it is required that the pressure-sensitive adhesive layer is stuck as it is, a member (in the case of a base material) that has been stuck to the laminate according to the present embodiment composed of the glass substrate and the pressure-sensitive adhesive layer Or may be an adherend) and may be subjected to the next step. When only the glass substrate on which the transparent conductive film is formed is required, in the laminated structure of the laminate and the adherend according to this embodiment, the glass substrate and the adhesive layer on which the transparent conductive film is formed. And the glass substrate on which the transparent conductive film is formed may be subjected to the next step. Alternatively, the laminate according to the present embodiment composed of the glass substrate on which the transparent conductive film is formed and the pressure-sensitive adhesive layer is peeled off from the laminated structure, and then the glass substrate on which the transparent conductive film is further formed is adhered. The glass layer on which the transparent conductive film obtained by peeling the agent layer is formed may be subjected to the next step. From the viewpoint that the number of steps for the glass substrate on which the transparent conductive film is formed is small, the former method of peeling the glass substrate on which the transparent conductive film is formed from the above laminated structure is preferable.

  In addition, although constituent elements other than the glass substrate on which the transparent conductive film is formed in the above laminated structure may be discarded, it is preferable to reuse at least one of the constituent elements. If the case where a base material is mother glass is demonstrated concretely as an example, an adhesive layer will be stuck on mother glass using the above-mentioned adhesive tape, and annealing treatment may be performed if necessary, and this embodiment is concerned. A laminated body is obtained, a glass substrate is attached to the adhesive layer of the laminated body, a transparent conductive film is formed on the glass substrate, and peeling is performed between the glass substrate on which the transparent conductive film is formed and the adhesive layer. In addition to obtaining a glass substrate on which a transparent conductive film is formed, the adhesive layer is also peeled off from the mother glass forming the base material, the mother glass is washed as necessary, and then the above-mentioned adhesive tape is used again. It is preferable to obtain a laminated body according to this embodiment having a mother glass as a base material and an adhesive layer, and to obtain a glass substrate on which a further transparent conductive film is formed.

  The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  For example, in the above description, the base material or the adherend is a glass substrate, but the present invention is not limited to this. The material constituting the substrate may be an organic material such as polyimide. Specific examples of the substrate in this case include a substrate film for dicing sheet, a protective sheet, a flexible printed circuit board having an outermost layer made of a resin layer, and a casing having a coating film on the outermost layer. The material constituting the base material may be an inorganic material other than a glass material, such as aluminum, iron alloy, silicon, or ceramics. Specific examples of the base material in this case include a silicon wafer, an alumina substrate, an aluminum alloy casing, a plated steel casing. The material constituting the substrate may be a composite material of an organic material and an inorganic material, such as a glass epoxy material.

  EXAMPLES Hereinafter, although an Example etc. demonstrate this invention further more concretely, the scope of the present invention is not limited to these Examples etc.

[Example 1]
(1) Preparation of coating solution 100 parts by mass of addition-curable silicone rubber (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KS-847H), 30 mass of silicone resin (manufactured by Dow Corning Toray, product name: SD4587L) And a platinum catalyst (manufactured by Dow Corning Toray, product name: SRX-212) (0.6 part by mass) were added, and a coating liquid in which the solid content concentration was adjusted to 25% by mass with methyl ethyl ketone was prepared.

(2) Production of pressure-sensitive adhesive sheet On one main surface of the polyethylene terephthalate base film, a release treatment including applying a release agent made of fluorosilicone was applied to obtain a heavy release type release sheet. Moreover, the peeling process including apply | coating the peeling agent which consists of a fluorosilicone was performed on one main surface of the base film made from a polyethylene terephthalate, and it was set as the light peeling type release sheet.

  The above coating solution was applied on the release surface of the above heavy release type release sheet with a knife coater and dried at 120 ° C. for 1 minute to obtain a coating layer having a thickness of 25 μm. The release surface of the light release release sheet is bonded to the coating layer of the laminate composed of the coating layer and the heavy release release sheet, and the heavy release release sheet, the pressure-sensitive adhesive composition layer, and the light release release A pressure-sensitive adhesive sheet having sheets arranged in this order was obtained.

(3) Production of Laminate The light release type release sheet of this pressure-sensitive adhesive sheet is peeled off and attached to one main surface of a base material made of a glass substrate made of alkali-free glass (product name: Eagle XG). Then, the heavy release type release sheet was peeled off to obtain a first laminate including a base material and an adhesive composition layer.

  The first laminate is placed in an oven that maintains an air atmosphere at a temperature of 240 ° C., placed in this atmosphere for 60 minutes, and then removed from the oven, in an air atmosphere at 23 ° C. and a relative humidity of 50%. An annealing process for cooling to 23 ° C. was performed to obtain a laminate as a test object.

[Comparative Example 1]
The 1st laminated body in Example 1 was made into the laminated body as a test object as it is. That is, it is a laminate having a pressure-sensitive adhesive composition layer that has not been annealed.

[Test Example 1] Evaluation of adhesive strength For each of the laminates as test subjects according to Examples and Comparative Examples, the adhesive strength of the adhesive layer to the base material was measured by the following method. In addition, in the case of the laminated body which concerns on a comparative example, although it is an adhesive composition layer that is contrasted with the adhesive layer of an Example, it may hereafter be simply called an adhesive layer and may be demonstrated.
By bonding the surface of the adhesive layer of each laminate to one main surface of a polyimide film (product name: Kapton 100H, manufactured by Toray DuPont), then cutting and trimming the polyimide film and the adhesive layer A sample in which a laminate composed of an adhesive layer having a width of 25 mm and a length of 100 mm and a polyimide film was disposed on a glass substrate was prepared. Using this sample in accordance with JIS Z0237: 2009, using a tensile tester (product name: Tensilon, manufactured by Orientec Co., Ltd.) under the conditions of a peeling speed of 300 mm / min and a peeling angle of 180 °, The resulting laminate was peeled off. This measured the adhesive force (mN / 25mm) with respect to the glass substrate which is a base material of the adhesive layer of an Example, and the adhesive composition layer of a comparative example. The measurement results are shown in Table 1.

[Test Example 2] Evaluation of removability For each of the laminates as test subjects according to Examples and Comparative Examples, the surface of the pressure-sensitive adhesive layer is formed of a glass substrate made of alkali-free glass as an adherend (manufactured by Corning). , Product name: Eagle XG) to obtain a structure for evaluation of removability. This structure was allowed to stand in an air atmosphere of 50% relative humidity and 23 ° C. for 24 hours, and then the glass forming the adherend was peeled off from the laminate composed of the pressure-sensitive adhesive layer and the substrate. Then, the main surface on the side facing the pressure-sensitive adhesive layer of the adherend is visually observed, and re-peeling without heat treatment depending on whether or not the material constituting the pressure-sensitive adhesive layer remains. The degree of sex was evaluated. In addition, the case where adhesion was not confirmed visually was set as (circle), and the case where it was confirmed was set as x.
A structure similar to that used for the evaluation of the removability without the above heat treatment was separately prepared. The structure is subjected to heat treatment for 60 minutes in an air atmosphere at 240 ° C., and further left in an air atmosphere at 50% relative humidity and 23 ° C. for 24 hours. The glass substrate forming the adherend was peeled from the resulting laminate. The main surface on the side of the adherend facing the adhesive layer is visually observed, and depending on whether or not the material constituting the adhesive layer remains, the removability in the case of heat treatment The degree was evaluated. Evaluation criteria are the same as in the case of no heat treatment. The evaluation results are shown in Table 1.

[Test Example 3] Measurement of mass reduction rate For each of the laminates as test subjects according to the examples and comparative examples, the material constituting this was scraped from the pressure-sensitive adhesive layer on the substrate made of a glass plate, and differential heat / Using a thermogravimetric simultaneous measurement device (manufactured by Shimadzu Corporation, product name: DTG60), the temperature was raised from room temperature (23 ° C.) to 300 ° C. at 5 ° C./min, and the mass at 40 ° C. was 200 ° C. and 250 ° C. The rate of mass reduction (unit: mass%) at each of ℃ and 300 ℃ was measured. The measurement results are shown in Table 1.

[Test Example 4] Evaluation of influence of outgas For each of the laminates as test objects according to Examples and Comparative Examples, the surface of the pressure-sensitive adhesive layer is made of an alkali-free glass having a thickness of 0.5 mm as an adherend. It stuck on one main surface of the board | substrate (Corning company make, product name: Eagle XG). Thereafter, an ITO film was formed on the surface of the adherend opposite to the surface facing the pressure-sensitive adhesive layer by sputtering. The resistance value of the formed ITO film was measured by a four-point method. When the resistivity obtained as a result of the measurement was 50Ω / □ or less, it was determined that the influence of outgasing was slight and good. The evaluation results are shown in Table 1.

  As shown in Table 1, in the laminated body of the example satisfying the conditions of the present invention, the mass reduction rate at 200 ° C. of the material constituting the adhesive is 0.20% by mass or less, and the laminated body is heated. In addition, defects due to outgas are less likely to occur, and it has excellent removability.

  The laminate of the present invention has a reduced possibility of generating outgas even when heat treatment is performed, and has excellent removability, for example, suitable for forming an ITO film on a glass substrate. used.

Claims (5)

A laminate comprising a substrate and an adhesive layer laminated on one surface of the substrate,
The pressure-sensitive adhesive layer is formed from a silicone-based pressure-sensitive adhesive composition,
The silicone-based pressure-sensitive adhesive composition includes a silicone rubber containing a siloxane bond as a main skeleton and an addition type organopolysiloxane containing an alkenyl group as a constituent component, and 0.01 parts by mass or more and 3 parts by mass per 100 parts by mass of the silicone rubber. Parts platinum catalyst and 15 parts by mass or more and 100 parts by mass or less of silicone resin per 100 parts by mass of the silicone rubber,
When the pressure-sensitive adhesive layer is heated from 23 ° C. to 300 ° C. at 5 ° C./min in an air atmosphere, the mass reduction rate at 300 ° C. with respect to the mass at 40 ° C. is 1.0 % by mass or less. A featured laminate. Wherein the surface of the pressure-sensitive adhesive layer side of the laminate in a state where an adherend is laminated, process the adhesive layer is heated is subjected laminate of claim 1. The laminate according to claim 2 , wherein the treatment for heating the pressure-sensitive adhesive layer is a surface treatment for a surface of the adherend opposite to the surface facing the pressure-sensitive adhesive layer. The laminate according to claim 3 , wherein the surface treatment includes a treatment for forming a transparent conductive film. A method for producing the laminate according to any one of claims 1 to 4,
The pressure-sensitive adhesive layer is formed through an annealing process including a step of placing in an air atmosphere at a temperature of 200 ° C. or higher for 60 minutes or more in a state where the pressure-sensitive adhesive composition layer composed of the silicone-based pressure-sensitive adhesive composition is exposed. A method for producing a laminate characterized by the above .