JP2015120884A - Resin sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin sheet capable of adhering excellently onto an adherend at lamination, and suppressing gas discharge at heating.SOLUTION: A resin sheet has an adhesive resin layer. The adhesive resin layer satisfies a characteristic (A1): a gel fraction increases by heating at 120°C for 5 minutes; and a ratio (G/G) of a gel fraction G(%) after the heating to a gel fraction G(%) before the heating is within a range of 1.1-10,000.

Description

  The present invention relates to a resin sheet.

  Adhesive resin sheets typified by pressure-sensitive adhesive sheets are widely used in various fields because of their good workability for application to adherends. For example, the resin sheet is used in the manufacture of flexible circuit boards. The circuit board is typically manufactured by laminating a resin sheet on a hard substrate such as glass, temporarily fixing a base film of the circuit board on the resin sheet, and mounting the circuit board on the base film. After forming, it is performed by separating the circuit board and the resin sheet. Patent document 1 is mentioned as a prior art document which discloses this kind of prior art. Patent Document 2 is a technical document related to a re-peelable pressure-sensitive adhesive sheet that is used by being attached to a semiconductor wafer.

JP 2012-186315 A JP-A-2005-53998

  In the manufacture of a circuit board as disclosed in Patent Document 1, for example, TFT pattern formation can be performed under heating conditions of 150 ° C. or higher. When the resin sheet used for the production is exposed to the high temperature as described above, the moisture and the like present in the sheet are vaporized to release gas. Even if the resin sheet and the adherend adhere well, the released gas enters the interface and lowers the adhesion between them. In addition, if there is a gap between the adherend and the resin sheet, the gas component in the gap expands during heating to reduce the adhesion area, so that the adhesion is also lowered. The decrease in adhesion not only causes generation of defective products and causes a decrease in yield, but also there is a possibility that the resin sheet may be detached and cause the process to stop, so that improvement has been demanded.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a resin sheet that can be satisfactorily adhered to an adherend at the time of bonding and in which gas release is suppressed at the time of heating.

According to the present invention, a resin sheet provided with an adhesive resin layer is provided. This adhesive resin layer has characteristics (A1): the gel fraction is increased by heating at 120 ° C. for 5 minutes, and after the heating to the gel fraction G _A (%) before the heating is performed. The ratio of gel fraction G _B (%) (G _B / G _A ) is in the range of 1.1 to 10,000; With this configuration, the adhesive resin layer can be satisfactorily adhered to the adherend at the time of bonding, and the gas fraction rapidly rises at the time of heating, thereby suppressing gas release from the adhesive resin layer. Is done. Therefore, according to the present invention, there is provided a resin sheet that can maintain a good adhesion state with an adherend even when exposed to heat.

Moreover, according to this invention, a resin sheet provided with an adhesive resin layer is provided. The adhesive resin layer, characteristics (A2): 120 ℃, the gel fraction is increased by heating for 5 minutes, and within the gel fraction G _B is 30% to 100% after subjecting to the heating Yes; By comprising in this way, the adhesive resin layer can be satisfactorily adhered to the adherend at the time of bonding, and the gel fraction quickly exceeds a predetermined value at the time of heating, so that the gas release from the adhesive resin layer Is suppressed. Therefore, according to the present invention, there is provided a resin sheet that can maintain a good adhesion state with an adherend even when exposed to heat.

  In a preferred embodiment of the technology disclosed herein, the resin sheet has a characteristic (B): 180 degree peel strength measured after the adhesive resin layer is attached to a glass plate and heated at 150 ° C. for 30 minutes, 0.05 to 5.0 N / 20 mm; The resin sheet satisfying the characteristic (B) can be a releasable resin sheet having both an adhesive force suitable for temporarily fixing the adherend and excellent removability.

  In a preferred embodiment of the technique disclosed herein, the content of the radical scavenger in the adhesive resin layer is 1% by weight or less. The radical scavenger can be a component that suppresses an increase in the gel fraction during heating. By setting the content of the radical scavenger to a predetermined value or less, the gel fraction can be increased efficiently.

  In a preferred embodiment of the technology disclosed herein, a carbon-carbon double bond is present in the adhesive resin layer. By comprising in this way, the carbon-carbon double bond (-C = C-) in the said resin layer reacts at the time of a heating, and a gel fraction rises rapidly. Moreover, it is preferable that the abundance of the carbon-carbon double bond in the adhesive resin layer is 0.1 to 2.0 mmol / g. Thereby, an increase in the gel fraction during heating can be suitably realized.

（上式中、Ｒは水素またはメチル基である。）；で表わされる加熱反応性基を有する化合物を含む。このように構成することで、加熱時に上記化合物中の炭素−炭素二重結合が反応してゲル分率が速やかに上昇する。 In a preferred aspect of the technology disclosed herein, the adhesive resin layer has the general formula (1):

(Wherein R is hydrogen or a methyl group); and a compound having a heat-reactive group represented by: By comprising in this way, the carbon-carbon double bond in the said compound reacts at the time of a heating, and a gel fraction rises rapidly.

  In a preferred aspect of the technology disclosed herein, the resin sheet further includes a resin film substrate that supports the adhesive resin layer. Since a resin sheet provided with a resin film substrate as a supporting substrate has a predetermined rigidity, it can be excellent in workability and handleability.

It is sectional drawing which shows one structural example of a resin sheet typically. It is sectional drawing which shows typically another structural example of the resin sheet. It is sectional drawing which shows typically another structural example of the resin sheet. It is sectional drawing which shows typically another structural example of the resin sheet. It is sectional drawing which shows typically another structural example of the resin sheet. It is sectional drawing which shows typically another structural example of the resin sheet.

Hereinafter, preferred embodiments of the present invention will be described. Note that matters other than matters specifically mentioned in the present specification and necessary for the implementation of the present invention can be grasped as design matters of those skilled in the art based on the prior art in this field. The present invention can be carried out based on the contents disclosed in this specification and common technical knowledge in the field.
In the following drawings, members / parts having the same action may be described with the same reference numerals, and redundant descriptions may be omitted or simplified. In addition, the embodiment described in the drawings is schematically illustrated in order to clearly explain the present invention, and does not necessarily accurately represent the size and scale of a resin sheet actually provided as a product.

<Configuration of resin sheet>
The resin sheet disclosed here includes an adhesive resin layer. This adhesive resin layer typically constitutes at least one surface (for example, both surfaces) of the resin sheet. The resin sheet may be a resin sheet with a substrate having the adhesive resin layer on one side or both sides of the substrate (support), and the adhesive resin layer is a release liner (a substrate having a release surface). Or a resin sheet without a base material such as a shape held in (5). In this case, the resin sheet may be composed only of the adhesive resin layer. The concept of the resin sheet here may include pressure-sensitive adhesive sheets that can be referred to as pressure-sensitive adhesive tapes, pressure-sensitive adhesive labels, pressure-sensitive adhesive films, and the like, and pressure-sensitive adhesive sheets such as adhesive sheets and adhesive films. The adhesive resin layer is typically formed continuously, but is not limited to such a form. For example, the adhesive resin layer is formed in a regular or random pattern such as a dot shape or a stripe shape. It may be a resin layer. Moreover, the resin sheet provided by this specification may be a roll shape, and may be a sheet form. Or the resin sheet of the form processed into various shapes may be sufficient.

  The resin sheet disclosed here may have, for example, a cross-sectional structure schematically shown in FIGS. Among these, FIG. 1, FIG. 2 is a structural example of the resin sheet with a base material of a double-sided adhesion type. In the resin sheet 1 shown in FIG. 1, adhesive resin layers 21 and 22 are respectively provided on each surface (both non-peelable) of a substrate 10, and these adhesive resin layers are at least on the adhesive resin layer side. Each has a configuration protected by release liners 31 and 32 serving as release surfaces. The resin sheet 2 shown in FIG. 2 is provided with adhesive resin layers 21 and 22 on each surface (both non-peelable) of the substrate 10, and one of the adhesive resin layers 21 is peeled on both surfaces. It has the structure protected by the release liner 31 which is the surface. This type of resin sheet 2 has a configuration in which the adhesive resin layer 22 is also protected by the release liner 31 by winding the resin sheet and bringing the other adhesive resin layer 22 into contact with the back surface of the release liner 31. It can be.

  3 and 4 are configuration examples of a baseless double-sided adhesive resin sheet. The resin sheet 3 shown in FIG. 3 has a configuration in which both surfaces 21A and 21B of a baseless adhesive resin layer 21 are protected by release liners 31 and 32, respectively, at least the adhesive resin layer side being a release surface. Have. The resin sheet 4 shown in FIG. 4 has a configuration in which one surface (adhesion surface) 21A of the baseless adhesive resin layer 21 is protected by a release liner 31 whose both surfaces are release surfaces. When the other surface 21B of the adhesive resin layer 21 is in contact with the back surface of the release liner 31, the other surface 21B can also be protected by the release liner 31. Yes.

  5 and 6 are configuration examples of a resin sheet with a single-sided adhesive base material. The resin sheet 5 shown in FIG. 5 is provided with an adhesive resin layer 21 on one surface 10A (non-peelable) of the substrate 10, and the surface (adhesive surface) 21A of the adhesive resin layer 21 is at least the adhesive resin. It has a configuration protected by a release liner 31 whose layer side is a release surface. The resin sheet 6 shown in FIG. 6 has a configuration in which an adhesive resin layer 21 is provided on one surface 10A (non-peelable) of the substrate 10. The other surface 10B of the substrate 10 is a release surface. When the resin sheet 6 is wound, the adhesive resin layer 21 comes into contact with the other surface 10B, and the surface (adhesive surface) 21B of the adhesive resin layer is The other surface 10B of the substrate is protected.

<Adhesive resin layer>
(Gel fraction)
The adhesive resin layer disclosed herein is characterized by an increase in gel fraction by heating at 120 ° C. for 5 minutes. The adhesive resin layer exhibiting the above characteristics exhibits good adhesion and followability because it has a relatively low gel fraction when the adhesive resin layer is bonded to the adherend, and the adherend surface It is possible to adhere closely to. For example, it is possible to satisfactorily adhere to a surface having irregularities. Good adhesion of the adhesive resin layer to the adherend surface may be due to the fact that there are few voids at the adherend interface. Can be prevented or suppressed. Further, when the resin sheet is heated to a predetermined temperature or higher, the gel fraction of the adhesive resin layer is quickly increased. Specifically, the gel fraction increases faster than the outgas component in the adhesive resin layer vaporizes and expands by the same heating, and the elasticity of the adhesive resin layer increases. Thereby, the vaporization expansion | swelling of an outgas component is suppressed and the gas emission from an adhesive resin layer is suppressed, As a result, the adhesive fall resulting from the gas emission at the time of a heating is suppressed. In short, the technique disclosed here realizes maintaining good adhesion even after heating by adhesion at the time of bonding and gas release suppression at the time of heating. According to the resin sheet as described above, for example, when the adherend is transported in a state where the resin sheet is attached, a problem that the resin sheet falls off due to vibration or the like during transport is prevented. The outgas component is typically a volatile component such as water present in the resin layer or a gas component present in a void in the resin layer.

The adhesive resin layer according to a preferred embodiment has a characteristic (A1): gel fraction that is increased by heating at 120 ° C. for 5 minutes, and before the heating (heating at 120 ° C. for 5 minutes). The ratio (G _B / G _A ) of the gel fraction G _B (%) after performing the heating with respect to G _A (%) is in the range of 1.1 to 10,000; As described above, the adhesion resin layer at the time of bonding the gel fraction G _A so relatively low, it is possible to satisfactorily close contact with the adherend surface. Also, during heating and the specific gel fraction is increased rapidly _(G B _/ G _A) is in the range of 1.1 to 10,000, gas release from adhesion resin layer is suppressed.

The adhesive resin layer according to another preferred embodiment has the following characteristics (A2): the gel fraction is increased by heating at 120 ° C. for 5 minutes, and the heating (heating at 120 ° C. for 5 minutes) is performed. gel fraction _{G B} is in the range of 30% to 100%; meet. As described above, the adhesion resin layer is on attachment because a relatively low gel fraction G _A, it is possible to satisfactorily close contact with the adherend surface. Further, at the time of heating because the gel fraction is rapidly increased to the gel fraction G _B is 30% or more, the gas release from the adhesion resin layer is suppressed.

As discussed above, the art disclosed herein, from the viewpoint of compatibility between the heating after adhesion and bonding property (initial adhesion), the adhesion to satisfy a ratio (G B _{/ G A)} is greater than 1 It implements by the structure provided with a resin layer. Taking into account the bonding properties and properties after heating (adhesion and removability, etc.), the ratio (G B _{/ G A)} is 2 or more (e.g. 5 or more, typically 10 or more) even Alternatively, it may be 100 or more (for example, 1000 or more, typically 5000 or more). The upper limit is not particularly limited in the ratio (G B _{/ G A),} in consideration of the influence on the characteristic after heating (e.g., peel strength), usually is suitably not more than 10,000, 50 or less (e.g., 20 Hereinafter, typically, it is preferably 15 or less. To set the gel fraction G _A relatively enhanced depending on the purpose and application, the ratio (G B _{/ G A)} is less than 5 (e.g. 3 or less, typically 2 or less) may be further May be 1.5 or less (typically 1.2 or less). In this specification, if _{G A} is 0%, and to satisfy a ratio _{(G B / G A)>} 1 If the _{G B} greater than 0%.

The gel fraction G _A may be a value lower than the gel fraction G _B, is not particularly limited insofar, the gel fraction G _A is too high, the adhesion between the adhesion resin layer and the adherend is May decrease. More specifically, the gel fraction G _A is too high, voids may be formed between the bonding property adhesion resin layer is reduced and the adherend, the gas present in said void upon heating expansion As a result, the adhesion between the adhesive resin layer and the adherend may be reduced. Further, there is a tendency that the step following ability is lowered. From this viewpoint, the gel fraction G _A is suitably not more than 90%, preferably 80% or less (e.g., 70% or less, typically 60% or less). Alternatively, 40% gel fraction _{G A} or less (e.g., 10% or less, typically less than 5%) may be used. The lower limit of the gel fraction _{G A} may be 0%, but usually more than 0.01% (e.g. 0.1% or more, typically 1% or more) is suitably not less than 2% It is. By increasing the gel fraction G _A, limits the flow of in a state of being attached to an adherend, the occurrence of defects protruding like from displacement or adherend end face of the adhesion resin layer is suppressed e.g. . From the viewpoint of imparting suitable elasticity to the adhesion resin layer, the gel fraction G _A is 10% or more (e.g., more than 20%, typically 30% or more) preferably to a gel fraction G _A May be 40% or more (for example, 50% or more, or 60% or more). Gel fraction G _A is measured by the method described below. The same applies to the gel fraction G _A in the examples below.

Gel fraction G _B may be any value higher than the gel fraction G _A, it is not particularly limited insofar, the gel fraction G _B is too low, there is a tendency that hardly dent holding the outgassing during heating . From this viewpoint, the gel fraction _{G B} is preferably 30% or more, more preferably 40% or more, more preferably 50% or more (e.g., 60% or more, and typically 70% or more) It is. From strongly suppressing outgassing upon heating, the gel fraction G _B is less than 80% (e.g. 90%, typically 95% or more), especially preferably from. The upper limit of the gel fraction _{G B} may be 100%, but is usually less 99.9% (e.g. 99% or less, typically 98% or less) which is suitable to be. Further, characteristics after heating (typically peel strength) in consideration of the influence on 80% or less gel fraction G _B (e.g., 70% or less, typically 65% or less) may be . Gel fraction G _B is measured by a method described later. The same applies to the gel fraction G _B in the Examples below.

  In addition, the adhesive resin layer disclosed herein is characteristic (A3): the adhesive resin layer before the above heating (120 ° C., 5 minutes heating) is performed at room temperature (25 ° C. ± 5 ° C.) for one week. In the case of storage, it is preferable that the increase in gel fraction (%) is not substantially observed after the storage; A resin sheet satisfying this characteristic (A3) exhibits a characteristic that the gel fraction increases after a predetermined heating, while the gel fraction does not increase when the heating is not performed. Adhesiveness with the adherend can be continuously maintained. That is, it is excellent in preservability and handleability.

The property (A3) is determined by measuring the gel fraction G _C (%) of the adhesive resin layer before the start of storage and the gel fraction G _D (%) after the storage and comparing them. That's fine. Since the gel fraction does not decrease under normal conditions, the ratio (G _D / G _C ) is 1 or more. In addition, “substantially no increase in gel fraction (%)” means typically the ratio (G _D / G _C ) = 1, but taking into account measurement errors etc. (G _D / G _C ) may be allowed to be less than 1.1. The ratio (G _D / G _C ) can be, for example, less than 1.05 (typically less than 1.02). Note that the storage condition in the characteristic (A3) is normal pressure (atmospheric pressure, may be 1 atm for convenience). The gel fractions G _C and G _D are measured by the method described later. The same applies to the embodiments described later.

[Gel fraction _{G A, G B, G C} , method of measuring _{G D]}
An adhesive resin layer sample (weight W1) of about 0.5 g was collected, wrapped in a purse-like shape with a porous polytetrafluoroethylene membrane (weight W2) having an average pore diameter of 0.2 μm, and the mouth was covered with an octopus thread (weight W3). Tie up. This package is soaked in 50 mL of toluene and kept at room temperature (typically 25 ° C.) for 7 days to elute only the sol component in the adhesive resin layer out of the membrane, and then the package is taken out to the outer surface. The adhering toluene is wiped off, the packet is dried at 130 ° C. for 2 hours, and the weight (W4) of the packet is measured. And a gel fraction is calculated | required by substituting each value to the following Formula.
Gel fraction (%) = [(W4-W2-W3) / W1] × 100
The gel fractions G _A , G _C , and G _D are the above-mentioned gel fractions using an adhesive resin layer sample from a resin sheet that has not been subjected to heat treatment (typically 120 ° C., heating for 5 minutes). It is measured by the measuring method. This resin sheet is typically not heated as described above after being produced by drying the adhesive resin layer.
The gel fraction G _B, is measured using the adhesion resin layer sample below. That is, a resin sheet having a form in which the surface of the adhesive resin layer is protected by the release liner is prepared. This resin sheet is sandwiched between two glass plates preheated to 120 ° C. and heated at 120 ° C. for 5 minutes. About the adhesive resin layer sample from the resin sheet after the said heating, a gel fraction is measured with the above-mentioned gel fraction measuring method.
As the porous polytetrafluoroethylene (PTFE) membrane, “Nitoflon NTF1122” (average pore diameter 0.2 μm, porosity 75%, thickness 85 μm) manufactured by Nitto Denko Corporation or its equivalent may be used. desirable. The glass plate used in the measurement of the gel fraction G _B is not particularly limited, it may be used a known or conventional glass plate.

(Carbon-carbon double bond)
There is no particular limitation on the method for producing the adhesive resin layer exhibiting the characteristic that the gel fraction is increased by heating at 120 ° C. for 5 minutes. For example, a method of increasing the gel fraction by causing a carbon-carbon double bond to be present in the resin sheet and reacting it at the time of heating is a preferred example. According to said method, the structure which satisfy | fills characteristic (A1), (A2) and (A3) is suitably realizable. When the above method is employed, a carbon-carbon double bond exists in the adhesive resin layer. This configuration is particularly advantageous in satisfying the characteristic (A3). The reason for this is that the carbon-carbon double bond is chemically stable without reacting with moisture or acidity in the air in a normal storage environment that can be industrially applied. On the other hand, for example, in a high temperature state of 60 ° C. or higher, radicals are generated and react with other molecules (for example, polymerization reaction or crosslinking reaction). By adopting an adhesive resin layer in which a carbon-carbon double bond is present, the resin sheet is excellent in handleability without causing an increase in the gel fraction of the adhesive resin layer during storage. Further, an increase in the gel fraction of the adhesive resin layer (hereinafter sometimes abbreviated as “increase in gel fraction during heating”) is quickly realized under predetermined heating conditions.

  In the above method, the presence form of the carbon-carbon double bond in the adhesive resin layer is not particularly limited. The carbon-carbon double bond may be present in, for example, a polymer (typically a base polymer described later), an oligomer, or a monomer. Among these, a polymer having relatively low mobility in the adhesive resin layer is preferable. As said polymer, the polymer which has a carbon-carbon double bond in a side chain or a principal chain is mentioned. Here, having a carbon-carbon double bond in the main chain means that a carbon-carbon double bond is present in the main chain skeleton of the polymer and a carbon-carbon double bond is present at the end of the main chain. Include. As for the oligomer, similarly to the polymer, an oligomer having a carbon-carbon double bond in a side chain or main chain (in the main chain skeleton, main chain end) is exemplified.

The form of the carbon-carbon double bond that may be present in the side chain of the polymer or oligomer, or the form of the carbon-carbon double bond that may be present in the monomer is not particularly limited. For example, a group containing a vinyl group (typically May be present in the form of an organic group. The vinyl group-containing group may be a vinyl group, an allyl group, or a (meth) acryloyl group. The method for introducing the carbon-carbon double bond into the polymer or oligomer is not particularly limited, and an appropriate method can be selected from methods known to those skilled in the art. From the viewpoint of molecular design and the like, a method of introducing a carbon-carbon double bond into the side chain of the polymer or oligomer is preferred.
In this specification, the main chain of the polymer or oligomer refers to a chain structure forming the skeleton of the polymer or oligomer. The side chain of the polymer or oligomer refers to a group (pendant, side group) bonded to the main chain or a molecular chain that can be regarded as a pendant.

In the technique disclosed here, the following method is exemplified as a typical method for causing a carbon-carbon double bond to exist in the adhesive resin layer.
(1) A method of using a polymer having a carbon-carbon double bond as the base polymer constituting the adhesive resin layer. Specifically, in this method, a polymer having a carbon-carbon double bond is included in the adhesive resin composition as a base polymer, and the adhesive resin layer is formed using the adhesive resin composition.
(2) A method in which a polymer, oligomer and / or monomer having a carbon-carbon double bond is included in the adhesive resin layer in addition to the base polymer constituting the adhesive resin layer. Specifically, in this method, an appropriate amount of the polymer, oligomer and / or monomer is added to the adhesive resin composition, and an adhesive resin layer is formed using the adhesive resin composition.
The above (1) and (2) may be used in combination.

  Examples of the adhesive resin layer in which a carbon-carbon double bond exists include an adhesive resin layer having a configuration in which a group having a carbon-carbon double bond (a heat-reactive group) exists. By allowing the heat-reactive group to be present in the adhesive resin layer, the heat-reactive group reacts during heating and the gel fraction of the adhesive resin layer can be increased. The heat-reactive group is preferably substantially inactive (non-reactive) in a state before heating (for example, 40 ° C. or lower at atmospheric pressure, typically room temperature). The heat-reactive group is not limited to the above group having a carbon-carbon double bond. This point will be described later.

（上式中、Ｒは水素またはメチル基である。）；で表わされる加熱反応性基（（メタ）アクリロイル基）を有する化合物を含む密着性樹脂層が挙げられる。ここで上記化合物は、ポリマー（典型的にはベースポリマー）、オリゴマーおよびモノマーを包含する。上記化合物を含む密着性樹脂層は、該化合物中の上記反応性基中の炭素−炭素二重結合が加熱時に反応して密着性樹脂層のゲル分率が速やかに上昇する。上記化合物はポリマーであることが好ましい。 As a suitable example of the adhesive resin layer in which a carbon-carbon double bond is present, the general formula (1):

(Wherein R is hydrogen or a methyl group); an adhesive resin layer containing a compound having a heat-reactive group ((meth) acryloyl group) represented by: Here, the compounds include polymers (typically base polymers), oligomers and monomers. In the adhesive resin layer containing the compound, the carbon-carbon double bond in the reactive group in the compound reacts upon heating, and the gel fraction of the adhesive resin layer rapidly increases. The compound is preferably a polymer.

  When the compound is a polymer (typically a base polymer), that is, when the polymer (typically the base polymer) has a heat-reactive group represented by the general formula (1), the polymer (typically The method for introducing the heat-reactive group into the base polymer is not particularly limited, and an appropriate method can be selected from methods known to those skilled in the art. For example, a method similar to the method for introducing a heat-reactive group into an acrylic polymer described later can be preferably employed. In the case where the compound is an oligomer, the reactive group may be introduced into the oligomer by the same method as in the case of the polymer. When the compound is a monomer, a monomer having the reactive group may be obtained or synthesized and included in the adhesive resin layer.

  The polymer having a carbon-carbon double bond is not particularly limited. For example, among those exemplified as the base polymer described later, an appropriate polymer can be selected and used in consideration of the characteristics of the adhesive resin layer. it can. When the polymer is a carbon-carbon double bond-free polymer, a polymer in which a carbon-carbon double bond is introduced into the carbon-carbon double bond-free polymer by a method such as chemical modification is preferably used. obtain.

  As a specific example of the method for introducing the carbon-carbon double bond into the polymer, a monomer having a functional group (hereinafter also referred to as “functional group A”) is copolymerized with the polymer, and then reacted with the functional group A. A compound having a functional group to be obtained (hereinafter also referred to as “functional group B”) and a carbon-carbon double bond is reacted (typically condensation or addition reaction) so that the carbon-carbon double bond does not disappear. A method is mentioned. Examples of the combination of the functional group A and the functional group B include a combination of a carboxy group and an epoxy group, a combination of a carboxy group and an aziridyl group, and a combination of a hydroxyl group and an isocyanate group. Of these, a combination of a hydroxyl group and an isocyanate group is preferable from the viewpoint of reaction traceability. In addition, the combination of the functional groups A and B may be one in which the functional group A is the functional group A and the other is the functional group B as long as a polymer having a carbon-carbon double bond is obtained. Alternatively, the one functional group may be the functional group B and the other functional group may be the functional group A. For example, in the case of a combination of a hydroxyl group and an isocyanate group, the functional group A may be a hydroxyl group (in this case, the functional group B becomes an isocyanate group) or an isocyanate group (in this case, a functional group). The group B becomes a hydroxyl group). Among these, a combination in which the base polymer has a hydroxyl group and the above compound has an isocyanate group is preferable. This combination is particularly preferred when the base polymer is an acrylic polymer.

  In addition, when the polymer is a vinyl alcohol polymer (typically polyvinyl alcohol), a vinyl bromide is added to the vinyl alcohol polymer (typically a vinyl alcohol polymer not containing a carbon-carbon double bond). A preferred example is a method in which an allyl halide such as vinyl halide or allyl bromide is reacted. In this method, the reaction is carried out under suitable basic conditions, and a vinyl alcohol polymer containing a vinyl group in the side chain is obtained by the reaction. Further, for example, a method for preparing a polymer having a carbon-carbon double bond using a microorganism producing a polymer as disclosed in Japanese Patent No. 4502363 may be adopted. Various conditions such as microbial species and microbial culture conditions in this method may be set by adopting the conditions described in the above-mentioned patent gazette or by appropriately modifying them within the scope of technical common knowledge of those skilled in the art.

The molar ratio (M _A / M _B ) between the mole of the functional group A (M _A ) and the mole of the functional group B (M _B ) is usually in the range of 0.2 to 10 from the viewpoint of both reactivity. It is suitable to set it as 0.5-5.0 (for example, 0.7-3.0, typically 1.0-2.5). Further, from the viewpoint of increasing the contact opportunity between the functional group A and the functional group B, a large amount of the functional group B-containing compound having a carbon-carbon double bond may be blended. In that case, the molar ratio (M _A / M _B ) is preferably less than 1 (for example, less than 0.99 or less than 0.95). The amount of the compound having the functional group B is a range satisfying the molar ratio of the above-mentioned (M A _{/ M B),} the polymer (typically having a functional group A, a carbon - before carbon double bond is introduced 1 part by weight (for example, 5 parts by weight or more, typically 10 parts by weight or more), preferably 40 parts by weight or less (for example, 30 parts by weight or less, typical) Is preferably about 15 parts by weight or less). For example, the above-described molar ratio (M _A / M _B ) and the compounding amount of the functional group B-containing compound having a carbon-carbon double bond are preferably applied to the configuration using the acrylic polymer described later as the base polymer. be able to.

  The polymer having a carbon-carbon double bond may be, for example, a diene polymer (typically a conjugated diene polymer). The diene polymer (typically conjugated diene polymer) is a polymer typically obtained by polymerizing or copolymerizing a diene (typically conjugated diene). Diene polymers (typically conjugated diene polymers) include butadiene polymers such as polybutadiene and styrene butadiene copolymers; isoprene polymers such as polyisoprene and styrene isoprene copolymers; chloroprene polymers such as polychloroprene. And the like.

  Moreover, since a carbon-carbon double bond has high chemical activity, an external double bond is more preferable than an internal double bond. Here, the internal double bond refers to a double bond existing in a state incorporated in the main chain of the polymer or oligomer. In this carbon-carbon double bond, both of its carbon atoms constitute the main chain. The external double bond refers to a double bond existing outside the molecular chain (for example, main chain) of the polymer or oligomer. In addition, when a carbon-carbon double bond is present at the end of the main chain of the polymer or oligomer, the double bond is an external double bond.

  When the technology disclosed herein is implemented in an embodiment including an adhesive resin layer including a polymer having carbon-carbon double bonds (typically a base polymer), the carbon-carbon two in the adhesive resin layer is used. What is necessary is just to set suitably content of the polymer (typically base polymer) which has a heavy bond according to the grade of the gel fraction raise at the time of the target heating, and it does not specifically limit it. For example, it is preferable to blend so as to realize the abundance of carbon-carbon double bonds described later.

  Examples of the monomers and oligomers having a carbon-carbon double bond disclosed herein (hereinafter also simply referred to as monomers / oligomers) include urethane oligomers, urethane (meth) acrylates, and trimethylolpropane tri (meth). Acrylate, tetramethylolmethane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol monohydroxypenta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1 (Meth) acryloyl group-containing compounds such as 1,4-butanediol di (meth) acrylate, 1,6-butanediol di (meth) acrylate and polyethylene glycol di (meth) acrylate; ) 2-5 mer acryloyl group-containing compound; and the like. These can be used alone or in combination of two or more. The oligomer having a carbon-carbon double bond may be one or more of oligomers such as urethane oligomers, polyether oligomers, polyester oligomers, polycarbonate oligomers, and polybutadiene oligomers.

In this specification, the oligomer refers to a polymer having a molecular weight of less than 3.0 × 10 ⁴ . The molecular weight of the oligomer is preferably 100 or more, and preferably 1.0 × 10 ⁴ or less. As the molecular weight of the oligomer, a standard polystyrene equivalent weight average molecular weight (Mw) determined by gel permeation chromatography (GPC) or a molecular weight calculated from a chemical formula is employed.

  When the technique disclosed herein is implemented in an embodiment including an adhesive resin layer including a monomer / oligomer having a carbon-carbon double bond, the monomer / carbon double carbon bond in the adhesive resin layer / What is necessary is just to set oligomer content suitably according to the grade of the gel fraction raise at the time of the target heating.

  The abundance of the carbon-carbon double bond in the adhesive resin layer may be appropriately set according to the target degree of increase in the gel fraction during heating, and is not particularly limited. The abundance of the carbon-carbon double bond in the adhesive resin layer is 0.01 mmol (hereinafter also referred to as mmol / g) or more per 1 g of the adhesive resin layer from the viewpoint of surely increasing the gel fraction during heating. It is suitable to be 0.2 mmol / g or more (for example, 0.3 mmol / g or more, typically 0.5 mmol / g or more). Moreover, when there are too many carbon-carbon double bonds, a crosslinking density will become high too much and there exists a possibility that adhesiveness with a to-be-adhered body may fall too much. From such a point of view, the amount of carbon-carbon double bonds is suitably 10.0 mmol / g or less, and is 5.0 mmol / g or less (eg, 3.0 mmol / g or less, typically 1.0 mmol / g or less).

The abundance of the carbon-carbon double bond is measured by NMR (Nuclear Magnetic Resonance) method. Specifically, an abundance of carbon-carbon double bonds is obtained by taking an appropriate amount of sample from the adhesive resin layer and measuring the sample dissolved in a measurement solvent to which a predetermined amount of internal standard substance is added. Is required. As an analysis apparatus, a Fourier transform NMR apparatus (manufactured by Bruker Biospin, “AVANCE III-600 with Cryo Probe”) or an equivalent thereof may be used. The following conditions can be adopted as measurement conditions.
[Measurement condition]
Observation frequency: ¹ H 600 MHz
Measuring solvent: CDCl ₃
Measurement temperature: 300K
Chemical shift standard: Measurement solvent ¹ H; 7.25 ppm

(Radical generator)
Moreover, it is preferable that the adhesive resin layer disclosed here contains a radical generator. Regardless of the presence or absence of carbon-carbon double bonds, it is known that when heated, radicals are generated by the cleavage of molecular bonds such as polymers and oxygen oxidation in the air. <By resin> Trouble countermeasures and the latest reforming and stabilization technology "Polymer Properties Study Group, published in 1981). Therefore, it is considered that when the radical is present during heating, a radical reaction (for example, a polymerization reaction or a crosslinking reaction) occurs, and the gel fraction of the adhesive resin sheet is increased. However, when trying to increase the gel fraction using the heat history that the resin sheet can be exposed to in use, the heat history is usually about 60 ° C. to 250 ° C., up to about 5 hours, Depending on the heat history, the radical reaction does not proceed rapidly, and gas release from the adhesive resin layer is not suppressed. In a preferred embodiment of the technique disclosed herein, the radical reaction agent is positively included in the adhesive resin layer to ensure the rapid progress of the reaction. Thereby, the gel fraction increase at the time of a heating can be implement | achieved rapidly. For example, when a carbon-carbon double bond is present in the adhesive resin layer, free radicals are generated from the radical generator during heating, and this is added to the carbon-carbon double bond to ensure the radical reaction. To increase the gel fraction of the adhesive resin layer more rapidly.

  In this specification, the “radical generator” refers to an agent that generates free radicals by being decomposed during heating. Typically, it may be a polymerization initiator used for radical polymerization. Examples of the radical generator include peroxide compounds (peroxide initiators) and azo compounds (azo initiators), which are polymerization initiators that can be used for radical polymerization. Of these, peroxide compounds having hydrogen abstraction reactivity are preferred. For example, when hydrogen in the polymer skeleton is extracted by a hydrogen abstraction reaction, a polymer radical is generated. By the reaction (recombination) of the polymer radicals, the gel fraction can be suitably increased. A radical generator can be used individually by 1 type or in combination of 2 or more types.

Examples of the peroxide initiator include organic peroxides such as diacyl peroxide, peroxyester, peroxydicarbonate, monoperoxycarbonate, peroxyketal, dialkyl peroxide, hydroperoxide, and ketone peroxide. And hydrogen peroxide.
Diacyl peroxide includes dibenzoyl peroxide (BPO), di-p-nitrobenzoyl peroxide, di-p-chlorobenzoyl peroxide, di (3,5,5-trimethylhexanoyl) peroxide, di-n. -Octanoyl peroxide, didecanoyl peroxide, dilauroyl peroxide, etc. are mentioned.
Peroxyesters include t-butyl peroxyneodecanoate, t-hexyl peroxypivalate, t-butyl peroxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexa Noate, t-hexylperoxy-2-ethylhexanoate, di (4-methylbenzoyl) peroxide, t-butylperoxyisobutyrate, 1,1-di (t-hexylperoxy) cyclohexane, t -Butyl peroxybenzoate, t-butyl peroxyacetate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane and the like.
Examples of the peroxydicarbonate include di (2-ethylhexyl) peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, di-sec-butyl peroxydicarbonate, and the like.
Examples of monoperoxycarbonate include t-butyl peroxyisopropyl carbonate, t-butyl peroxy-2-ethylhexyl carbonate, t-amyl peroxyisopropyl carbonate, t-butyl peroxy-2-ethylhexyl carbonate, and the like. .
As peroxyketals, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, , 1-bis (t-butylperoxy) cyclododecane, 1,1-bis (t-butylperoxy) cyclohexane, n-butyl-4,4-bis (t-butylperoxy) valate and the like.
Dialkyl peroxides include di-t-butyl peroxide, dicumyl peroxide, t-butyl cumyl peroxide, α, α'-bis (t-butylperoxy-m-isopropyl) benzene, 2,5-di- (T-butylperoxy) hexyne-3 and the like.
Examples of the hydroperoxide include cumene hydroperoxide, t-butyl hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylcyclohexane-2,5-dihydroperoxide and the like.
Examples of the ketone peroxide include cyclohexanone peroxide, 3,3,5-trimethylcyclohexanone peroxide, methylcyclohexanone peroxide, and methyl ethyl ketone peroxide.
Of these, diacyl peroxide and peroxyester are preferable, and BPO, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate and t-hexylperoxy-2-ethylhexanoate are more preferable. preferable. Peroxide initiators can be used singly or in combination of two or more.

  Commercially available peroxide-based initiators include "Permec Series", "Perhexa Series", "Perbutyl Series", "Perocta Series", "Park Mill Series", "Parroyl Series", "Nyper Series ”,“ Perhexyl Series ”and the like (both manufactured by NOF Corporation). Of these, “Nyper series”, “Perocta series” and “Perhexyl series” are preferable.

  Examples of the azo initiator include 2,2′-azobisisobutyronitrile (AIBN), 2,2′-azobis (2-methylpropionamidine) disulfate, 2,2′-azobis (2- Amidinopropane) dihydrochloride, 2,2′-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2′-azobis (N, N′-dimethyleneisobutylamidine) 2,2′-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate, 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2 ′ -Azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane-1-carbon Bonitoriru), 2,2'-azobis (2,4,4-trimethylpentane), dimethyl-2,2'-azobis (2-methyl propionate), and the like.

  In addition, radical generators include persulfates such as potassium persulfate and ammonium persulfate; substituted ethane compounds such as phenyl-substituted ethane; aromatic carbonyl compounds; redox compounds based on combinations of peroxides and reducing agents (redox compounds) And the like which can also function as a polymerization initiator. Examples of redox initiators include a combination of peroxide and ascorbic acid (such as a combination of hydrogen peroxide and ascorbic acid), a combination of peroxide and iron (II) salt (such as hydrogen peroxide and A combination of iron (II) salt and the like, and a combination of persulfate and sodium bisulfite.

  The radical generator may be an inorganic or organic oxidant known in organic synthesis. Examples of the oxidizing agent include peroxides that can be used as the above-described radical polymerization initiator, peracetic acid, trifluoroperacetic acid, perbenzoic acid, metachloroperbenzoic acid, monoperoxyphthalic acid, performic acid, and the like. An organic peracid (percarboxylic acid) is mentioned. Of these, metachloroperbenzoic acid is preferred. These can be used alone or in combination of two or more.

  When the adhesive resin layer disclosed herein contains a radical generator, the addition method is not particularly limited. For example, a method of adding a polymerization initiator that can also be a radical generator at the time of polymerizing the base polymer is preferable. In this method, the polymerization initiator is added so that a predetermined amount remains after polymerization. The remaining amount of the polymerization initiator (the amount of the radical generator present) can be adjusted not only by the addition amount of the polymerization initiator but also by the polymer polymerization conditions, the drying conditions when forming the adhesive resin layer, and the like. Or you may typically add and mix in a base polymer containing liquid in adhesive resin composition. In this method, the radical generator can be added to the composition together with other additive components (such as a crosslinking agent).

  The 10-hour half-life temperature and activation energy of the radical generator are not particularly limited as long as they are determined by the heating conditions exposed during use, the target post-heating characteristics, and the like. For example, a radical generator having a 10-hour half-life temperature of 20 ° C. to 107 ° C. (typically 50 ° C. to 100 ° C.) and a radical generator having an activation energy of 100 to 150 kJ / mol can be preferably used. The 10-hour half-life temperature may be a value measured using an appropriate solvent (for example, benzene).

  When the adhesive resin layer disclosed herein contains a radical generator, the abundance (content) of the radical generator may be appropriately determined according to the degree of increase in the gel fraction during heating, and is not particularly limited. . The amount of the radical generator present in the adhesive resin layer is 0.001% by weight or more (eg, 0.005% by weight or more, typically 0.01% by weight or more) from the viewpoint of increasing the gel fraction during heating. It is preferable that The upper limit of the abundance of the radical generator is not particularly limited, and is suitably 5% by weight or less (eg, 3% by weight or less, typically 2% by weight or less). From the viewpoint of suppressing the crosslinking density from becoming too high, the content is preferably 1% by weight or less (for example, 0.5% by weight or less, typically 0.2% by weight or less).

The abundance of the radical generator can be measured by a high performance liquid chromatography (HPLC) method. For example, the abundance of the radical generator (eg, BPO) can be measured by the following method. The same applies to the abundance of the radical generator in the examples described later.
About 0.1 g of the adhesive resin layer sample is collected, added with ethyl acetate, and shaken for 24 hours. Thereafter, 10 mL of acetonitrile is added and shaken for another 3 hours. About the obtained solution filtered through a membrane filter having a pore diameter of 0.2 μm, the amount of radical generator in the sample is measured by HPLC. The HPLC measurement can be performed under the following conditions using, for example, a trade name “Ultimate 3000” manufactured by Dionex as an analyzer.
[Measurement condition]
Column: ZORBAX Eclipse Plus (3.0 mmφ × 50 mm, 1.8 μm)
Eluent: Distilled water / acetonitrile reverse phase gradient Condition flow rate: 0.8 mL / min
Detector: PDA (190 nm to 400 nm), 230 nm extraction column temperature: 40 ° C.
Injection volume: 5 μL

(Other gel fraction increasing components)
Moreover, the adhesive resin layer disclosed herein may include an epoxy compound such as an epoxy resin. Thereby, the epoxy group in an epoxy-type compound is ring-opened at the time of a heating, and the gel fraction of an adhesive resin layer can rise because epoxy-type compounds react with each other. The epoxy compound includes polymers, oligomers and monomers having at least one epoxy group as a heat-reactive group in the molecule.

  In an embodiment in which the adhesive resin layer contains an epoxy compound, a polymer having a functional group (for example, a carboxy group) having reactivity with an epoxy group can be used as the base polymer. Thereby, the gel fraction of the adhesive resin layer can be increased by the reaction of the epoxy group that is ring-opened during heating with the functional group (for example, carboxy group) in the polymer. By adopting the acrylic polymer as the base polymer, it is possible to achieve an increase in the gel fraction during heating while obtaining characteristics (for example, adherence followability and adhesion) due to the acrylic polymer. The content of the epoxy compound is not particularly limited, and based on the common general technical knowledge in the field, if an appropriate amount capable of realizing practically acceptable storage stability and the target gel fraction increase upon heating is added. Good.

  In addition, the epoxy-based compound has a tendency that the ring-opening reaction gradually proceeds depending on moisture, temperature, and the like, and the gel fraction may increase with time even when heating at a predetermined temperature or higher is not performed. Therefore, when the adhesive resin layer contains an epoxy compound, it is desirable to take measures such as considering the storage environment. Or you may implement the technique disclosed here in the aspect provided with the adhesive resin layer which does not contain an epoxy-type compound substantially in consideration of preservability etc.

  Moreover, in the adhesive resin layer disclosed here, a carboxy group and a hydroxyl group may exist as a heat-reactive group. Due to the presence of carboxy groups and hydroxyl groups in the adhesive resin layer, these functional groups undergo a dehydration reaction during heating, and the gel fraction of the adhesive resin layer can be increased. For example, a structure containing a compound having a carboxy group (typically a polymer) and a compound having a hydroxyl group (typically a polymer) or a structure containing a compound having a carboxy group and a hydroxyl group (typically a polymer) A functional resin layer. The compound can be, for example, an acrylic polymer.

In the above adhesive resin layer, the molar ratio (M _C / M _H ) between the mole of carboxy group (M _C ) and the mole of hydroxyl group (M _H ) is usually from the viewpoint of increasing the gel fraction during heating. The range is 1 to 10, and it is appropriate that the range is about 0.2 to 5 (for example, 0.3 to 3, typically 0.5 to 2).

(Base polymer)
The adhesive resin layer disclosed herein has, as a base polymer, an acrylic polymer or rubber polymer known in the field of pressure-sensitive adhesive or adhesive (for example, natural rubber, chloroprene rubber, styrene-butadiene rubber, nitrile rubber, etc.) , Polyester, urethane polymer, polyether, silicone polymer, polyamide, fluorine polymer, ethylene-vinyl acetate polymer, epoxy resin, vinyl chloride polymer, cyanoacrylate polymer, cellulose polymer (nitrocellulose polymer, etc. ), Phenolic resin, polyimide, polyolefin, styrene polymer, polyvinyl acetate, polyvinyl alcohol, polyvinyl acetal, polyvinyl pyrrolidone, polyvinyl butyral, polybenzimidazole, melamine resin, A resin may be one comprising one or more of various polymers such as resorcinol based polymer. From the viewpoints of adhesion and cost, acrylic polymers, rubber polymers, polyesters, urethane polymers, polyethers, silicone polymers, polyamides, and fluorine polymers are preferred, acrylic polymers and rubber polymers are more preferred, and acrylic polymers are preferred. A polymer is particularly preferred.
The “base polymer” of the adhesive resin refers to the main component of the polymer contained in the adhesive resin. The polymer is preferably a rubber-like polymer exhibiting rubber elasticity in a temperature range near room temperature. Further, in this specification, “main component” refers to a component contained in an amount exceeding 50% by weight unless otherwise specified.

In addition, the adhesive resin layer (adhesive resin) formed including the base polymer is in the form of a soft solid (viscoelastic body) in the temperature range near room temperature, and is easily adhered to the adherend by pressure. A material having properties is preferable. A typical example of the adhesive resin is an adhesive. The adhesive here is generally defined as “CA Dahlquist,“ Adhesion: Fundamental and Practice ”, McLaren & Sons, (1966) P. 143”, and generally has a complex tensile modulus E ^* (1 Hz). <10 < ⁷ > dyne / cm < ² > material (typically a material having the above properties at 25 [deg.] C.).

As the acrylic polymer, for example, a polymer of a monomer raw material that includes alkyl (meth) acrylate as a main monomer and can further include a submonomer copolymerizable with the main monomer is preferable. Here, the main monomer means a component occupying more than 50% by weight of the monomer composition in the monomer raw material.
The “acrylic polymer” refers to a polymer containing a monomer unit derived from a monomer having at least one (meth) acryloyl group in one molecule as a monomer unit constituting the polymer. Hereinafter, a monomer having at least one (meth) acryloyl group in one molecule is also referred to as an “acrylic monomer”. The acrylic polymer in this specification is defined as a polymer containing monomer units derived from an acrylic monomer. A typical example of such an acrylic polymer is an acrylic polymer in which the proportion of the acrylic monomer in the monomer composition of the acrylic polymer is more than 50% by weight.
The term “(meth) acryloyl” means acryloyl and methacryloyl comprehensively. Similarly, “(meth) acrylate” means acrylate and methacrylate, and “(meth) acryl” generically means acrylic and methacryl.

As the alkyl (meth) acrylate, for example, a compound represented by the following formula (2) can be preferably used.
CH ₂ = C (R ¹ ) COOR ² (2)
Here, R ¹ in the above formula (2) is a hydrogen atom or a methyl group. R ² is a chain alkyl group having 1 to 20 carbon atoms (hereinafter, such a range of the number of carbon atoms may be represented as “C _1-20 ”). From the viewpoint of the storage elastic modulus of the adhesive resin layer, an alkyl (meth) acrylate in which R ² is a chain alkyl group of C _1-14 (for example, C _1-12 , typically C _4-12 ) is preferable. , An alkyl acrylate in which R ¹ is a hydrogen atom and R ² is a chain alkyl group of C _5-14 (eg, C _6-14 , typically C _8-12 ) (hereinafter, simply referred to as C _5-14 alkyl acrylate) More preferred).

Examples of the alkyl (meth) acrylate in which R ² is a C _1-20 chain alkyl group include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, and n-butyl. (Meth) acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate , Octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) Acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate, And eicosyl (meth) acrylate. These alkyl (meth) acrylates can be used alone or in combination of two or more. Preferred alkyl (meth) acrylates include n-butyl acrylate (BA), 2-ethylhexyl acrylate (2EHA), and lauryl acrylate (LA). From the viewpoint of obtaining an appropriate peel strength, 2EHA and LA are particularly preferable.

The blending ratio of the main monomer in all monomer components is preferably 70% by weight or more, more preferably 90% by weight or more, and further preferably 95% by weight or more. The upper limit of the mixing ratio of the main monomer is not particularly limited, but is preferably 99.5% by weight or less (for example, 99% by weight or less). The acrylic polymer may be obtained by polymerizing only the main monomer. When the C _5-14 alkyl acrylate is included as the main monomer, the blending ratio of the C _5-14 alkyl acrylate in the main monomer is preferably 70% by weight or more, and 90% by weight or more. More preferably, it is 95% by weight or more (typically 99 to 100% by weight). The technique disclosed herein can be preferably implemented in an embodiment in which 50% by weight or more (eg, 70% by weight or more, typically 95% by weight or more) of the monomer composition in the monomer raw material is 2EHA and / or LA.

A submonomer having copolymerizability with the main monomer, alkyl (meth) acrylate, can be useful for introducing a crosslinking point into the acrylic polymer or increasing the cohesive strength of the acrylic polymer. In the technology disclosed herein, a monomer having a functional group (functional group A) capable of reacting with a functional group (functional group B) of a carbon-carbon double bond-containing monomer described later is employed as a submonomer. Is preferred. As the submonomer, for example, the following functional group-containing monomer components can be used alone or in combination of two or more.
Carboxy group-containing monomers: ethylenically unsaturated monocarboxylic acids such as acrylic acid (AA), methacrylic acid (MAA) and crotonic acid; ethylenically unsaturated dicarboxylic acids such as maleic acid, itaconic acid and citraconic acid and anhydrides thereof (Maleic anhydride, itaconic anhydride, etc.).
Hydroxyl group-containing monomer: For example, hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate; Unsaturated alcohols such as vinyl alcohol and allyl alcohol; ether compounds such as 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, and diethylene glycol monovinyl ether.
Amide group-containing monomer: For example, (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methylolpropane (meth) acrylamide, N-methoxymethyl (Meth) acrylamide, N-butoxymethyl (meth) acrylamide.
Amino group-containing monomer: for example, aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate.
Epoxy group-containing monomer: for example, glycidyl (meth) acrylate, methyl glycidyl (meth) acrylate, allyl glycidyl ether.
Cyano group-containing monomer: for example, acrylonitrile, methacrylonitrile.
Keto group-containing monomers: for example, diacetone (meth) acrylamide, diacetone (meth) acrylate, vinyl methyl ketone, vinyl ethyl ketone, allyl acetoacetate, vinyl acetoacetate.
Monomers having a nitrogen atom-containing ring: for example, N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N-vinyl Pyrrole, N-vinylimidazole, N-vinyloxazole, N-vinylmorpholine, N-vinylcaprolactam, N- (meth) acryloylmorpholine.
Alkoxysilyl group-containing monomer: For example, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, 3- (meth) acryloxypropylmethyldimethoxysilane, 3- (meth) acryloxy Propylmethyldiethoxysilane.
Isocyanate group-containing monomer: (meth) acryloyl isocyanate, 2- (meth) acryloyloxyethyl isocyanate, m-isopropenyl-α, α-dimethylbenzyl isocyanate.

  As the submonomer, a carboxy group-containing monomer is preferably used from the viewpoint of improving cohesion, and the carboxy group-containing monomer is more preferably AA or MAA. In addition, the carboxy group-containing monomer can also be used when the gel fraction during heating is increased by reaction with a hydroxyl group. Alternatively, the above hydroxyl group-containing monomer may be used for the purpose of reaction with a carboxy group. A carboxy group-containing monomer and a hydroxyl group-containing monomer can be used in combination as a submonomer.

  The amount of the submonomer may be appropriately selected so as to achieve a desired cohesive force, and is not particularly limited. Usually, from the viewpoint of achieving a good balance between cohesion and other properties (for example, adhesion), the amount of the secondary monomer (preferably a carboxy group-containing monomer) is 0.1% by weight in the total monomer components of the acrylic polymer. % Or more, preferably 0.3% by weight or more (for example, 1% by weight or more). Further, the amount of the secondary monomer (preferably carboxy group-containing monomer) is suitably 30% by weight or less, preferably 10% by weight or less (for example, 5% by weight or less) in all monomer components.

  Further, when an acrylic polymer having a carbon-carbon double bond is used as the base polymer, it can react with a functional group (functional group B) of a compound having a carbon-carbon double bond, which will be described later, as a submonomer. It is preferable to use a submonomer having a functional group (functional group A). In such a case, the type of submonomer is determined by the compound type. As the submonomer having the functional group A, for example, a carboxy group-containing monomer, an epoxy group-containing monomer, a hydroxyl group-containing monomer, and an isocyanate group-containing monomer are preferable, and a hydroxyl group-containing monomer is particularly preferable. By using a hydroxyl group-containing monomer as a submonomer, the acrylic polymer has a hydroxyl group. On the other hand, by using an isocyanate group-containing monomer as a compound having a carbon-carbon double bond, the hydroxyl group of the acrylic polymer reacts with the isocyanate group of the compound, and the carbon-carbon derived from the compound. Double bonds are introduced into the acrylic polymer.

  Moreover, when using a submonomer for the purpose of reaction with a compound having a carbon-carbon double bond, the amount of the submonomer (preferably a hydroxyl group-containing monomer) is selected from the viewpoint of increasing the gel fraction during heating. The content is preferably 1% by weight or more (for example, 5% by weight or more, typically 10% by weight or more) in the components. In addition, from the viewpoint of suppressing the crosslinking density from becoming too high, it is preferably 40% by weight or less (for example, 30% by weight or less, typically 15% by weight or less).

  For the purpose of increasing the cohesive strength of the acrylic polymer, other copolymer components other than the above-mentioned secondary monomer can be used. Examples of such copolymer components include vinyl ester monomers such as vinyl acetate and vinyl propionate; aromatic vinyl compounds such as styrene, substituted styrene (α-methylstyrene, etc.), vinyltoluene; cyclohexyl (meth) acrylate, cyclopentyl di Cycloalkyl (meth) acrylates such as (meth) acrylate, isobornyl (meth) acrylate, etc .; aryl (meth) acrylate (eg, phenyl (meth) acrylate), aryloxyalkyl (meth) acrylate (eg, phenoxyethyl (meth) acrylate) Aromatic ring-containing (meth) acrylates such as arylalkyl (meth) acrylates (eg benzyl (meth) acrylate); olefins such as ethylene, propylene, isoprene, butadiene and isobutylene Monomers such as vinyl chloride and vinylidene chloride; alkoxy group-containing monomers such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate; vinyl ether monomers such as methyl vinyl ether and ethyl vinyl ether; . Other copolymerization components other than these submonomers can be used alone or in combination of two or more. The amount of such other copolymerization component is not particularly limited as long as it is appropriately selected depending on the purpose and application. For example, it is 20% by weight or less (for example, 2 to 20% by weight, typical of all monomer components of the acrylic polymer). Specifically, it is preferably 3 to 10% by weight.

  Furthermore, a polyfunctional monomer can be used as a copolymerizable component for the purpose of crosslinking treatment of an acrylic polymer. Examples of the multifunctional monomer include hexanediol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, and trimethylol. One or more of propanetri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, epoxy acrylate, polyester acrylate, urethane acrylate and the like can be used. The amount of the polyfunctional monomer is not particularly limited as long as it is appropriately selected depending on the purpose and application. For example, it is 30% by weight or less (for example, 20% by weight or less, typically 20% by weight or less in the total monomer component of the acrylic polymer). Is preferably about 10% by weight or less).

  The method for obtaining the acrylic polymer having the above monomer composition is not particularly limited, and various polymerizations known as synthetic methods for acrylic polymers such as solution polymerization method, emulsion polymerization method, bulk polymerization method, suspension polymerization method and the like. A method can be appropriately employed. For example, a solution polymerization method can be preferably employed. As a monomer supply method when performing solution polymerization, a batch charging method, a continuous supply (dropping) method, a divided supply (dropping) method, or the like that supplies all monomer raw materials at once can be appropriately employed. The solvent used for the solution polymerization can be appropriately selected from known or common organic solvents such as toluene and ethyl acetate. The polymerization temperature can be appropriately selected according to the type of monomer and solvent to be used, the type of polymerization initiator, and the like, for example, about 20 ° C. to 120 ° C. (typically 40 ° C. to 80 ° C.). it can.

  The initiator used for the polymerization can be appropriately selected from known or commonly used polymerization initiators according to the type of polymerization method. For example, one or more polymerization initiators exemplified as the radical generator can be preferably used. Of these, peroxide initiators are preferable, diacyl peroxides and peroxyesters are more preferable, and BPO, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-hexylperper. More preferred is oxy-2-ethylhexanoate. When a predetermined amount of the polymerization initiator remains after polymerization and is used as a radical generator, the polymerization initiator and the radical generator disclosed herein can be the same type.

  The amount of the polymerization initiator used may be a normal amount, for example, about 0.005 to 1 part by weight (typically 0.01 to 1 part by weight) with respect to 100 parts by weight of all monomer components. You can choose from a range. Further, when the polymerization initiator is also used as a radical generator, the use amount of the polymerization initiator may be set in consideration of that.

(Acrylic polymer having a carbon-carbon double bond)
In addition, the acrylic polymer disclosed herein is preferably an acrylic polymer having a carbon-carbon double bond from the viewpoint of increasing the gel fraction during heating. Acrylic polymers are also advantageous in that they have a high degree of freedom in selecting monomer materials and can easily control physical properties. The method using an acrylic polymer having a carbon-carbon double bond corresponds to the method (1) in which a carbon-carbon double bond is present in the adhesive resin layer.

  The method for introducing a carbon-carbon double bond into the acrylic polymer is not particularly limited. For example, a compound having a functional group (functional group B) capable of reacting with a functional group (functional group A) introduced by copolymerization in an acrylic polymer and a carbon-carbon double bond is converted into a carbon-carbon double bond. A method of reaction (typically condensation or addition reaction) can be preferably employed so as not to disappear. Examples of the combination of the functional group A and the functional group B include a combination of a carboxy group and an epoxy group, a combination of a carboxy group and an aziridyl group, and a combination of a hydroxyl group and an isocyanate group. Of these, a combination of a hydroxyl group and an isocyanate group is preferable from the viewpoint of reaction traceability. From the viewpoint of polymer design and the like, a combination in which the acrylic polymer has a hydroxyl group and the above compound has an isocyanate group is particularly preferable.

  The compound having a carbon-carbon double bond may have a functional group B that can react with the functional group A as described above. Preferable examples of such compounds include, for example, isocyanate group-containing monomers (isocyanate group-containing compounds) exemplified as submonomers that can be used for the polymerization of acrylic polymers. Of these, 2- (meth) acryloyloxyethyl isocyanate is more preferable. An acrylic polymer having a carbon-carbon double bond by reacting an isocyanate group of an isocyanate group-containing compound having a carbon-carbon double bond with a hydroxyl group of an acrylic polymer to form a bond (typically a urethane bond). Is preferably realized.

The amount of isocyanate group-containing monomer, from the viewpoint of reactivity with the hydroxyl group as the functional group A, can be appropriately set in a range satisfying the molar ratio of the above-mentioned _(M A _/ M _B). For example, 1 part by weight (for example, 5 parts by weight or more, typically 100 parts by weight of an acrylic polymer having a hydroxyl group (typically an acrylic polymer before a carbon-carbon double bond is introduced) 10 parts by weight or more), preferably about 40 parts by weight or less (for example, 30 parts by weight or less, typically 15 parts by weight or less).

Moreover, the method of raising the gel fraction at the time of heating by making the hydroxyl group in an acrylic polymer remain and making this residual hydroxyl group react with another reactive functional group (for example, carboxy group) is also employ | adopted preferably. In this case, the molar ratio (M _A / M _B ) between the hydroxyl group as the functional group A and the isocyanate group as the functional group B is suitably more than 1, and is preferably 1.1 or more.

If the weight average molecular weight (Mw) of the base polymer (preferably an acrylic polymer) in the technology disclosed herein is too small, the cohesive force of the adhesive resin layer is insufficient and the adhesive remains on the adherend surface. May be likely to occur. On the other hand, when Mw is too large, the adhesion to the adherend may be easily lowered. From such a viewpoint, a base polymer (preferably an acrylic polymer) having a Mw in the range of 10 × 10 ^{4 to} 500 × 10 ⁴ is preferable. With a base polymer (preferably an acrylic polymer) having an Mw of 20 × 10 ⁴ or more and 100 × 10 ⁴ or less (for example, 30 × 10 ⁴ or more and 70 × 10 ⁴ or less), better results can be realized. In addition, in this specification, Mw means the value of standard polystyrene conversion obtained by GPC.

(Monomer / oligomer having carbon-carbon double bond)
Moreover, the technique disclosed here can be preferably implemented also in the aspect provided with the adhesive resin layer containing the monomer / oligomer which has a carbon-carbon double bond. As the monomer / oligomer, those described above can be preferably used. In the embodiment using an acrylic polymer as the base polymer, one or more of the above-mentioned (meth) acryloyl group-containing compound and a multimer (for example, 2 to 5 mer) of the (meth) acryloyl group-containing compound are used. It is preferable. The multimer can be, for example, a polyfunctional (typically 2-5 functional) compound. The method using a monomer / oligomer having a carbon-carbon double bond corresponds to the method (2) in which a carbon-carbon double bond is present in the above-mentioned adhesive resin layer.

(Photopolymerization initiator)
Moreover, it is preferable that the adhesive resin layer disclosed here contains a photopolymerization initiator for the purpose of lightening peeling when the resin sheet is peeled again. When the resin sheet is peeled off from the adherend, the adhesive resin layer is cured and shrunk by irradiation with active energy rays (for example, ultraviolet rays (UV)) in advance, and re-peeling can be easily performed. This configuration is also advantageous in preventing damage to the adherend surface. The above configuration is particularly suitable for applications where good removability is required (for example, applications for temporarily fixing a flexible circuit board and applications for fixing / protecting a semiconductor element).

  Examples of the photopolymerization initiator include a ketal photopolymerization initiator, an acetophenone photopolymerization initiator, a benzoin ether photopolymerization initiator, an acylphosphine oxide photopolymerization initiator, an α-ketol photopolymerization initiator, Aromatic sulfonyl chloride photopolymerization initiator, photoactive oxime photopolymerization initiator, benzoin photopolymerization initiator, benzyl photopolymerization initiator, benzophenone photopolymerization initiator, thioxanthone photopolymerization initiator, etc. Or 2 or more types can be used.

The photopolymerization initiator preferably has a hydroxyl group in the molecule. As such a hydroxyl group-containing photopolymerization initiator, those having a hydroxyl group among the above photopolymerization initiators can be preferably used. For example, benzophenone derivatives, alkylphenone derivatives, and acetophenone derivatives are preferable examples.
Examples of the benzophenone derivative include o-acryloxybenzophenone, p-acryloxybenzophenone, o-methacryloxybenzophenone, p-methacryloxybenzophenone, and p- (meth) acryloxyethoxybenzophenone. Also, benzophenone-4-carboxylic acid esters of acrylates such as 1,4-butanediol mono (meth) acrylate, 1,2-ethanediol mono (meth) acrylate, 1,8-octanediol mono (meth) acrylate, etc. It is possible to use. Examples of the alkylphenone derivatives include 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- {4- [4 -(2-Hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propan-1-one. Examples of the acetophenone derivative include 1-hydroxycyclohexyl-phenyl-ketone. The said photoinitiator can be used individually by 1 type or in combination of 2 or more types. Among them, 1-hydroxycyclohexyl-phenyl-ketone, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl, because of its excellent curing speed and thick film curability. Phenyl} -2-methyl-propan-1-one is preferred.

  The blending amount of the photopolymerization initiator is suitably about 0.1 to 10 parts by weight with respect to 100 parts by weight of the base polymer (preferably acrylic polymer), and 0.5 to 5 parts by weight. Is preferred.

  When the adhesive resin layer disclosed herein contains an acrylic polymer as a base polymer, it may contain a polymer other than the acrylic polymer in addition to the acrylic polymer. Examples of the polymer other than the acrylic polymer include those other than the acrylic polymer among the various polymers exemplified as the base polymer. Such a polymer can be a polymer having a carbon-carbon double bond. When the adhesive resin layer disclosed herein contains a polymer other than the acrylic polymer in addition to the acrylic polymer, the content of the polymer other than the acrylic polymer is 100 weights with respect to 100 parts by weight of the acrylic polymer. The amount is suitably not more than 50 parts by weight, preferably not more than 50 parts by weight, more preferably not more than 30 parts by weight, and still more preferably not more than 10 parts by weight. The content of the polymer other than the acrylic polymer may be 5 parts by weight or less or 100 parts by weight or less with respect to 100 parts by weight of the acrylic polymer. The technique disclosed herein can be preferably implemented in an embodiment in which, for example, 99.5 to 100% by weight of the base polymer is an acrylic polymer.

(Crosslinking agent)
The adhesive resin composition used for forming the adhesive resin layer preferably contains a crosslinking agent in addition to the base polymer from the viewpoint of improving the cohesiveness of the adhesive resin layer. The type of the crosslinking agent is not particularly limited. For example, an isocyanate crosslinking agent, an epoxy crosslinking agent, an oxazoline crosslinking agent, an aziridine crosslinking agent, a melamine crosslinking agent, a peroxide crosslinking agent, a urea crosslinking agent, a metal Examples thereof include alkoxide crosslinking agents, metal chelate crosslinking agents, metal salt crosslinking agents, carbodiimide crosslinking agents, and amine crosslinking agents. These crosslinking agents can be used alone or in combination of two or more. Of these, isocyanate crosslinking agents and metal chelate crosslinking agents are preferred.

  Moreover, when the adhesive resin layer contains a polymer or oligomer having a carbon-carbon double bond, it is preferable to use a metal chelate crosslinking agent. Since the metal chelate crosslinking agent is a coordination bond, the polymer and oligomer after crosslinking with the metal chelate crosslinking agent have a structural freedom (for example, deformation, etc.) as compared with the case of covalent crosslinking. The degree of freedom) tends to be maintained. Thereby, the reaction opportunity (typically polymerization reaction and the opportunity of a crosslinking reaction) of the said carbon-carbon double bond increases at the time of a heating, and the gel fraction raise at the time of a heating can be implement | achieved efficiently.

  The metal chelate-based crosslinking agent may typically have a structure in which a polyvalent metal is covalently or coordinated with an organic compound. Examples of the polyvalent metal atom include Al, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Ba, Mo, La, Sn, and Ti. Of these, Al, Zr, and Ti are preferable. Examples of the organic compound include alkyl esters, alcohol compounds, carboxylic acid compounds, ether compounds, and ketone compounds. The metal chelate-based crosslinking agent can typically be a compound having a configuration in which an oxygen atom in the organic compound is bonded (covalent bond or coordinate bond) to the polyvalent metal.

  The content of the crosslinking agent in the adhesive resin composition when the crosslinking agent is included is not particularly limited, but the adhesive resin layer is acrylic from the viewpoint of coexistence of cohesiveness and other properties (for example, peel strength). In the case of a resin-based resin layer, the amount is preferably about 0.01 to 10 parts by weight (for example, 0.05 to 5 parts by weight) with respect to 100 parts by weight of the acrylic polymer.

(Radical scavenger)
The adhesive resin layer disclosed herein may contain a radical scavenger such as an antioxidant from the viewpoint of storage stability. Since the radical scavenger is literally an agent that functions to trap radicals in the adhesive resin layer, for example, when a carbon-carbon double bond is present in the adhesive resin layer, the radical is carbon-carbon. Addition to a double bond may be inhibited. When the technique disclosed here is implemented in an embodiment in which a carbon-carbon double bond is present or an embodiment including a radical generator, an increase in the amount of radical scavenger suppresses an increase in gel fraction during heating. There is a fear. From such a viewpoint, in the technique disclosed herein, it is preferable to limit the blending amount of the radical scavenger.

  The concept of the radical scavenger disclosed herein may include an antioxidant and a light stabilizer, and a typical example is an antioxidant. Examples of the antioxidant include various conventionally known antioxidants such as a phenol-based antioxidant, a phosphorus-based (phosphite-based) antioxidant, a sulfur-based antioxidant, and an amine-based antioxidant. . One antioxidant can be used alone, or two or more antioxidants can be used in combination.

  Examples of phenolic antioxidants include monophenolic antioxidants such as 2,6-di-tert-butyl-4-methylphenol and 2,6-di-tert-butyl-4-ethylphenol; -Methylenebis (4-methyl-6-tert-butylphenol), 2,2'-methylenebis (4-ethyl-6-tert-butylphenol), 4,4'-butylidenebis (3-methyl-6-tert-butylphenol), Bisphenol antioxidants such as 4,4′-thiobis (3-methyl-6-tert-butylphenol); 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl) -4-hydroxybenzyl) benzene, tetrakis- [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane, 1,1,3- Squirrel (2-methyl-4-hydroxy -5-t-butylphenyl) polymer phenolic antioxidant such as butane; and the like.

  The phenolic antioxidant may be a hindered phenolic antioxidant. Examples of the hindered phenol antioxidant include pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-). tert-butyl-4-hydroxyphenyl) propionate, 4,6-bis (dodecylthiomethyl) -o-cresol, triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) Propionate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, polycondensate of dimethyl succinate and 4-hydroxy-2,2,6,6 tetramethyl-1-piperidineethanol (succinic acid) Dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6 tetramethyl Piperidine polycondensate), and the like.

Examples of phosphorus antioxidants include tris (2,4-di-t-butylphenyl) phosphite, tris (nonylphenyl) phosphite, triphenyl phosphite, distearyl pentaerythritol diphosphite, and the like. .
Examples of sulfur-based antioxidants include dilauryl-3,3′-thiodipropionate, dimyristyl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, pentaerythritol tetra Examples include lauryl thiopropionate.
Examples of amine-based antioxidants include phenyl-α-naphthylamine and diphenylamine.

  The content of the radical scavenger (typically antioxidant) in the adhesive resin layer is 1% by weight or less (eg, 0.5% by weight or less, typically from the viewpoint of increasing the gel fraction during heating as described above. Is preferably 0.1% by weight or less. The adhesive resin layer may not contain a radical scavenger (typically an antioxidant). However, if there is no radical scavenger such as an antioxidant at all, oxidation may proceed at room temperature due to dissolved oxygen in the adhesive resin layer, so an appropriate amount of radical scavenger (typically antioxidant) Agent). From such a viewpoint, the content of the radical scavenger in the adhesive resin layer is preferably 0.001% by weight or more (eg, 0.005% or more, typically 0.01% or more). The abundance of the radical scavenger can be measured, for example, by the same method as the method for measuring the abundance of the radical generator.

(Other additive components)
Moreover, it is preferable that the adhesive resin composition disclosed here contains a silane coupling agent for the purpose of improving adhesion to an adherend (typically glass). Examples of silane coupling agents include vinyl group-containing silane compounds, epoxy group-containing silane compounds, styryl group-containing silane compounds, (meth) acryl group-containing silane compounds, amino group-containing silane compounds, ureido group-containing silane compounds, and mercapto group-containing silanes. 1 type (s) or 2 or more types, such as a compound, an isocyanate group containing silane compound, a silyl group containing sulfide, can be used. Of these, amino group-containing silane compounds having excellent storage stability are preferred.

  Examples of the amino group-containing silane compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane, and N- (2-aminoethyl). Examples include 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropyltriethoxysilane, γ-anilinopropyltrimethoxysilane, and γ-anilinopropyltriethoxysilane. Of these, 3-aminopropyltrimethoxysilane is more preferable.

  The content of the silane coupling agent is 0.01 parts by weight or more (for example, 0. 03 parts by weight or more, typically 0.05 parts by weight or more). From the viewpoint of storage stability, the content of the silane coupling agent is less than 1.0 part by weight (for example, 0.5 part by weight or less, typically 100 parts by weight of the base polymer (preferably an acrylic polymer)). Specifically, it is preferably 0.3 parts by weight or less.

  The adhesive resin composition may be a tackifier, a leveling agent, a crosslinking aid, a plasticizer, a softener, a filler, a colorant (pigment, dye, etc.), an antistatic agent, an ultraviolet absorber, if necessary. It may contain various additives that are common in the field of adhesive resin compositions, such as light stabilizers. About these various additives, conventionally well-known things can be used by a conventional method, and since it does not characterize this invention in particular, detailed description is abbreviate | omitted.

(Method for forming adhesive resin layer)
The adhesive resin layer disclosed herein can be a layer formed from a pressure-sensitive adhesive (pressure-sensitive adhesive layer), a layer formed from an adhesive (adhesive layer), or a resin layer having easy adhesion on the surface. . The adhesive resin layer (layer made of an adhesive resin) in the technology disclosed herein is an aqueous adhesive resin composition, a solvent-type adhesive resin composition, a hot-melt adhesive resin composition, or an active energy ray curable type. It can be an adhesive resin layer formed from an adhesive resin composition. The water-based adhesive resin composition refers to an adhesive resin composition having a form in which an adhesive resin (adhesive resin-forming component) is contained in a water-based solvent (aqueous solvent). The concept of the adhesive resin composition includes a water-dispersed adhesive resin composition (a composition in which the adhesive resin is dispersed in water) and a water-soluble adhesive resin composition (the adhesive resin is dissolved in water). In the form of a composition) or the like. The solvent-type adhesive resin composition refers to an adhesive resin composition in a form that includes an adhesive resin in an organic solvent. The technique disclosed here can be preferably implemented in an aspect including an adhesive resin layer formed from a solvent-type adhesive resin composition.

  The adhesive resin layer disclosed herein can be formed by a conventionally known method. For example, a method of forming an adhesive resin layer by applying (typically applying) an adhesive resin composition to a peelable surface (peeling surface) and drying can be preferably employed. Moreover, the method (direct method) of forming the adhesive resin layer by directly applying (typically applying) the adhesive resin composition to the substrate and drying it can also be preferably employed. Furthermore, by adopting a method (transfer method) of forming an adhesive resin layer on the surface by applying an adhesive resin composition to the release surface and drying it, and transferring the adhesive resin layer to a substrate Also good. As the release surface, the surface of the release liner, the back surface of the substrate after the release treatment, or the like can be used. The coating may be performed using a known or conventional coater such as a gravure roll coater or a reverse roll coater.

  From the viewpoint of promoting the crosslinking reaction and improving the production efficiency, the adhesive resin composition is preferably dried under heating. The drying temperature can be, for example, about 40 ° C. to 150 ° C., and is usually preferably about 60 ° C. to 130 ° C. For example, in the case of drying at 100 ° C. or lower (typically about 80 ° C.) (for example, 5 minutes or lower, typically about 3 minutes), the solvent is being volatilized. Therefore, it is considered that the gel fraction of the adhesive resin layer does not substantially increase. In addition, after the adhesive resin composition is dried, aging is performed for the purpose of adjusting the component transfer in the adhesive resin layer, the progress of the crosslinking reaction, the relaxation of the strain that may exist in the base material or the adhesive resin layer, and the like. You may go. The aging conditions are not particularly limited. For example, aging is performed at a temperature of about 25 ° C. to 70 ° C. (typically 40 ° C. to 60 ° C.) for 10 to 120 hours (typically 24 to 48 hours). Is appropriate.

  The thickness of the adhesive resin layer disclosed herein is not particularly limited and can be appropriately selected depending on the purpose. Usually, the thickness of the adhesive resin layer is suitably about 5 to 200 μm, and preferably about 10 to 150 μm (for example, 15 to 100 μm, typically 25 to 80 μm) from the viewpoint of adhesion and the like. When the resin sheet disclosed here is a double-sided adhesive resin sheet provided with adhesive resin layers on both sides of the substrate, the thickness of each adhesive resin layer may be the same or different.

<Base material>
In the single-sided adhesive type or double-sided adhesive type resin sheet with a substrate, various sheet-like substrates can be used as a substrate for supporting (lining) the adhesive resin layer. As the substrate, a resin film, paper, cloth, rubber sheet, foam sheet, metal foil, a composite of these, or the like can be used. Examples of resin films include polyolefin films such as polyethylene (PE), polypropylene (PP), and ethylene / propylene copolymers; polyester films such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); vinyl chloride resin films Vinyl acetate resin film; polyimide resin film; polyamide resin film; fluororesin film; cellophane; Examples of paper include Japanese paper, kraft paper, glassine paper, high quality paper, synthetic paper, top coat paper, and the like. Examples of the fabric include woven fabrics and non-woven fabrics made of various fibrous substances alone or by blending. Examples of the fibrous material include cotton, suf, manila hemp, pulp, rayon, acetate fiber, polyester fiber, polyvinyl alcohol fiber, polyamide fiber, polyolefin fiber and the like. Examples of rubber sheets include natural rubber sheets and butyl rubber sheets. Examples of the foam sheet include a foamed polyurethane sheet and a foamed polychloroprene rubber sheet. Examples of the metal foil include aluminum foil and copper foil.

In a preferred embodiment, a resin film having a predetermined rigidity (strength) and excellent workability and handleability is used as a substrate. By using a highly rigid resin film substrate, when the adherend is thin, it is possible to suitably prevent the adherend from being bent or damaged during transportation. From the same viewpoint, it is preferable to use a polyester film as the resin film substrate. In this specification, the “resin film” is typically a non-porous film and is a concept that is distinguished from a so-called nonwoven fabric or woven fabric. Density of the resin film may be used as the substrate, approximately 0.85~1.50g / cm ³ (e.g., ^{0.90g / cm 3 ~1.20g / cm 3} , typically 0.92 g / ^cm 3 ~ 1.05 g / cm ³ ).

  In addition, for the above-mentioned base material (for example, resin film base material), a filler (inorganic filler, organic filler, etc.), an anti-aging agent, an antioxidant, an ultraviolet absorber, an antistatic agent, a lubricant as necessary. Various additives such as plasticizers and colorants (pigments, dyes, etc.) may be blended.

  On the surface (adhesive resin layer side surface) on which the adhesive resin layer of the substrate (for example, resin film substrate, rubber sheet substrate, foam sheet substrate, etc.) is disposed, corona discharge treatment, plasma treatment, Known or conventional surface treatments such as ultraviolet irradiation treatment, acid treatment, alkali treatment, and primer coating may be applied. Such a surface treatment may be a treatment for improving the adhesion between the substrate and the adhesive resin layer, in other words, the anchoring property of the adhesive resin layer to the substrate. A surface treatment in which a polar group such as a hydroxyl group (—OH group) is introduced into the surface of the substrate on the adhesive resin layer side can be preferably employed. Or you may provide a conventionally well-known adhesive layer between a resin sheet and a base material for the purpose of improving the adhesiveness of the resin sheet and base material disclosed here. For example, in an application to be bonded to a thin adherend, an adhesive as disclosed in Japanese Patent No. 4744262 and Japanese Patent No. 5094832 is disposed between a resin sheet and a resin film substrate, thereby It is possible to prevent bending and breakage of the adherend by utilizing the rigidity of the film substrate.

  Moreover, when the resin sheet disclosed here is a single-sided adhesive resin sheet in which an adhesive resin layer is provided on one side of the substrate, a release treatment is performed on the non-adhesive resin layer-forming surface (back side) of the substrate. The peeling treatment may be performed with an agent (back treatment agent). The back treatment agent that can be used for the formation of the back treatment layer is not particularly limited, and the purpose is a silicone-based back treatment agent, a fluorine-based back treatment agent, a long-chain alkyl-based back treatment agent, or other known or commonly used treatment agents. It can be used according to the application.

  The thickness of the substrate is not particularly limited and can be appropriately selected depending on the purpose, but it can generally be 1 to 800 μm. From the viewpoints of processability, handleability, workability, etc., the thickness of the substrate is preferably 2 μm or more (for example, 3 μm or more, typically 5 μm or more), and is 700 μm or less (for example, 500 μm or less, typically 200 μm or less).

<Release liner>
A conventional release paper or the like can be used as the release liner, and is not particularly limited. For example, it consists of a release liner having a release treatment layer on the surface of a liner substrate such as a resin film or paper, or a low adhesive material such as a fluorine-based polymer (polytetrafluoroethylene, etc.) or a polyolefin resin (polyethylene, polypropylene, etc.). A release liner or the like can be used. The release treatment layer may be formed, for example, by surface-treating the liner base material with a release treatment agent such as silicone-based, long-chain alkyl-based, fluorine-based, or molybdenum sulfide.

  The total thickness of the resin sheet disclosed here (which may include an adhesive resin layer and a substrate, but does not include a release liner) is not particularly limited, and is suitably in the range of about 5 to 1000 μm. . The total thickness of the resin sheet is preferably about 10 to 500 μm (for example, 15 to 300 μm, typically 20 to 200 μm) in consideration of adhesive properties and the like. Further, from the viewpoint of handleability and the like, the total thickness of the resin sheet is more preferably 30 μm or more (for example, 50 μm or more, typically 70 μm or more).

<Adhesive resin composition>
According to this specification, the adhesive resin composition used in order to form the adhesive resin layer disclosed here is provided. In a preferred embodiment, the adhesive resin composition has the characteristics (a1): an adhesive resin layer having a thickness of 30 μm formed by applying the resin composition to a peelable support and drying at 80 ° C. for 3 minutes. When the gel fraction is G _A (%), and the gel fraction when the adhesive resin layer is further heated at 120 ° C. for 5 minutes is G _B (%), the ratio (G _B / G _A ) is 1. In the range of 1 to 10,000; According to the above adhesive resin composition, an adhesive resin layer that can be satisfactorily adhered to an adherend when bonded and that suppresses outgassing when heated is realized.

In another preferred embodiment, the adhesive resin composition has the characteristic (a2): 30 μm thick adhesive formed by applying the resin composition to a peelable support and drying at 80 ° C. for 3 minutes. the gel ratio of the sex resin layer and G _{a (%),} when the gel fraction when heated for 5 minutes at further 120 ° C. the said seal adhesive resin layer was G _{B (%),} the ratio (G B _/ G _a)> 1, and a gel fraction _{G B} is in the range of 30% to 100%; meet. According to the above adhesive resin composition, an adhesive resin layer that can be satisfactorily adhered to an adherend when bonded and that suppresses outgassing when heated is realized.

  Further, the adhesive resin composition disclosed herein has characteristics (a3): an adhesive resin having a thickness of 30 μm formed by applying the resin composition to a peelable support and drying at 80 ° C. for 3 minutes. It is preferable that when the layer is stored at room temperature (25 ° C. ± 5 ° C.) for one week, no increase in gel fraction (%) is substantially observed after the storage. In addition, the said adhesive resin layer is an adhesive resin layer before performing heating (typically 120 degreeC, the heating for 5 minutes).

  The adhesive resin composition disclosed herein includes components that can be included in the above-described adhesive resin layer (base polymer; polymer, oligomer, monomer having a carbon-carbon double bond; radical generator; photopolymerization initiator; A radical scavenger; a silane coupling agent; and other additive components) may be preferably contained in the above-described blending ratio. The base polymer is preferably an acrylic polymer. Moreover, it is preferable that a carbon-carbon double bond exists in the adhesive resin composition as in the case of the adhesive resin layer. Since the technical significance of these matters is as described above, description thereof will not be repeated here.

<Characteristics of adhesive sheet>
The resin sheet disclosed here preferably has a 180 degree peel strength (vs. PEN peel strength) with respect to the PEN film of 0.1 N / 20 mm or more. The resin sheet exhibiting the above-mentioned peel strength can adhere well to an adherend (typically an adherend made of PEN) and has excellent bonding properties. The peel strength is more preferably 0.2 N / 20 mm or more (for example, 0.3 N / 20 mm or more, typically 0.5 N / 20 mm or more). Also, if the peel strength is too high, the workability for reattachment tends to be reduced, so the peel strength is 5.0 N / 20 mm or less (eg, 3.0 N / 20 mm or less, typically 1.0 N / 20 mm). Or less). The peel strength is a peel strength measured before heating (heating at 120 ° C. for 3 minutes). The PEN peel strength can be measured by the following method.

[Measurement method for PEN peel strength]
A single-sided adhesive resin sheet is used as it is, and a double-sided adhesive resin sheet whose one surface is lined with a PET film is cut into a size of 20 mm in width and 100 mm in length to prepare a measurement sample. In an environment of 23 ° C. and 50% RH, the adhesive resin layer surface is pressure-bonded by reciprocating a 2 kg rubber roller to the surface of the PEN film. After leaving this in the same environment for 30 minutes, the peel strength (N / 20 mm width) is measured using a tensile tester in accordance with JIS Z0237: 2000 under conditions of a peel angle of 180 degrees and a tensile speed of 300 mm / min. To do. As the PET film substrate for backing, a PET film (thickness 75 μm thin red solid printing) manufactured by Daisan Paper Industry Co., Ltd. can be used. As the PEN film as the adherend, a trade name “Teonex Q65FA” manufactured by Teijin DuPont Films Ltd. can be used. As the tensile tester, a variable-angle peel tester (trade name “Yamamoto-type variable-angle peel measuring machine YM-121” manufactured by Asahi Seiko Co., Ltd.) can be used.

  The resin sheet disclosed here preferably has a maximum gap length of 1000 μm or less at the adherend interface formed when attached to an adherend having a step of 25 μm in a step following test. . Since the resin sheet is excellent in the step following property at the time of bonding, the resin sheet can be satisfactorily adhered to an adherend having a step on the surface. The maximum length of the void is more preferably 800 μm or less (for example, 600 μm or less, typically 300 μm or less). The step followability test is performed by the method described in Examples described later.

  Moreover, the resin sheet disclosed here has a 180 degree peel strength (peel strength after heating) measured after sticking an adhesive resin layer on a glass plate and heating it at 150 ° C. for 30 minutes, from 0.05 to It is preferably 5.0 N / 20 mm (characteristic (B)). When the peel strength is not less than a predetermined value, the resin sheet can be well adhered to the adherend even after heating. The peel strength may be 0.2 N / 20 mm or more. On the other hand, when the peel strength exceeds 5.0 N / 20 mm, re-peelability is lowered, and there is a risk that problems such as damage to the adherend surface occur when peeled from the adherend after use. From such a viewpoint, the peel strength is more preferably 4.0 N / 20 mm or less (for example, 3.0 N / 20 mm or less, typically 1.5 N / 20 mm or less). The resin sheet having a peel strength after heating of 1.5 N / 20 mm or less (for example, 0.5 N / 20 mm or less, typically 0.3 N / 20 mm or less) does not cause cohesive failure and has substantially no adhesive residue. It is particularly preferable because it can be absent. For example, the peel strength can be suitably reduced by including a photopolymerization initiator in the adhesive resin layer and irradiating an active energy ray (for example, UV) before peeling the resin sheet. The peel strength after the heating may be a value before performing an easy peel treatment such as active energy ray (for example, UV) irradiation or a value after carrying out the easy peel treatment. . According to the resin sheet showing the peel strength after heating without carrying out the easy peel treatment, good post-heating adhesion and re-peelability can be realized without requiring easy peel treatment such as UV irradiation. . The peel strength after the heating is measured by the method described in Examples below.

  Moreover, it is preferable that the resin sheet disclosed here does not recognize bubbles having a maximum diameter of 2.0 mm or more at the adherend interface in the bubble generation evaluation test during heating. The bubble generation evaluation test is measured by the method described in Examples described later.

<Application>
The use of the resin sheet disclosed herein is not particularly limited. For example, the environment is exposed to heating at 60 ° C. to 250 ° C. (for example, 100 ° C. to 230 ° C., typically 130 ° C. to 200 ° C.) after pasting. It can be preferably used as a resin sheet used in. In the heating environment described above, the conventional pressure-sensitive adhesive sheet has an outgas component (typically, a volatile component such as moisture present in the resin layer or a gas component present in the void in the resin layer). It is vaporized and expanded by the same heating and appears as bubbles at the adherend interface, which may cause problems such as floating and peeling from the adherend. Since the resin sheet disclosed here suppresses the release of gas derived from such outgas components, it can maintain good adhesion even when exposed to the above heating conditions.

  Moreover, since the resin sheet disclosed here may also be excellent in removability, it is suitable, for example, as a resin sheet used in a mode of being peeled after the heating. The resin sheet can be preferably used as a temporary fixing sheet or a protective sheet.

  Examples of the application exposed to the heating as described above include a semiconductor element manufacturing application. For example, it is preferable as a wafer fixing sheet (typically a laser dicing sheet) for fixing the wafer to a fixing plate (for example, a hard substrate such as a glass plate or an acrylic plate) in semiconductor wafer processing (typically silicon wafer processing). Can be used. Further, the resin sheet disclosed herein can be preferably used as a protective sheet for protecting the wafer (for example, a circuit forming surface) in the wafer processing.

  The above-mentioned sheet has an appropriate degree of adhesion so as not to be peeled off from an adherend (typically a semiconductor element or a hard substrate) at the time of processing or conveyance in the above-mentioned production, and is excellent from the adherend after achieving the purpose. Re-peeling properties are required. In particular, it is important that the sheet is prevented from being deteriorated in properties such as adhesion to heating during the production of a semiconductor element. For example, the semiconductor element can be manufactured through a film forming process (for example, a reflective film forming process) after performing laser dicing on the wafer fixed by the sheet. During the laser dicing, the wafer and the fixing plate generate heat. The amount of heat generated by laser dicing tends to increase with the recent increase in wafer size. In addition, a film forming process (typically a reflective film forming process) that can be performed after laser dicing is usually performed at a temperature of 130 ° C. to 200 ° C. for about 2 to 5 hours. Since the resin sheet disclosed here can maintain good characteristics (typically adhesion) to the heating as described above, for example, as a wafer fixing sheet (preferably a laser dicing sheet), It is preferably used for manufacturing a semiconductor device including a laser dicing process. Moreover, since the resin sheet disclosed here can be excellent in level | step difference followability, it can become the thing excellent in the adhesiveness to the wafer surface (circuit formation surface) which has an unevenness | corrugation. Furthermore, the surface of the adherend may not be damaged during peeling.

  As described above, the resin sheet disclosed herein is preferably applied to the use of manufacturing semiconductor elements. Therefore, according to this specification, the manufacturing method of the semiconductor element using the resin sheet disclosed here is provided. In a preferred embodiment, the manufacturing method includes a step of fixing a semiconductor wafer to a resin sheet disposed (for example, fixed) on the surface of a fixing plate (typically a hard substrate) (fixing step); and processing the semiconductor wafer And a process (processing process). In a more preferred embodiment, the processing step includes a step (heating step) of heating to 60 ° C. or higher (eg, 130 ° C. to 200 ° C.). During the heating, since the resin sheet is typically in a state where both surfaces are sandwiched between adherends, reaction inhibition due to oxygen in the atmosphere is suppressed, and the gel fraction of the adhesive resin layer is increased. Is preferably realized. The heating process can be, for example, a laser dicing process and / or a film forming process (typically a reflective film forming process).

  In the manufacturing method, the chip diced by the dicing process can be picked up through the expanding process. That is, the manufacturing method may include a step of removing the resin sheet from the semiconductor wafer after the heating step (removal step, typically a peeling step). In a preferred embodiment, an active energy ray (typically UV) irradiation step is performed before the removing step for the purpose of reducing the peeling (re-peeling) of the resin sheet. When this process is included, it is preferable to include a photopolymerization initiator in the adhesive resin layer. Note that other technical matters necessary for manufacturing the semiconductor element can be implemented by those skilled in the art based on the common general technical knowledge in the field, and thus will not be particularly described here.

  The resin sheet disclosed herein is for temporary fixing used for manufacturing a thin substrate such as a circuit board (typically a flexible circuit board (FPC)), an organic EL panel, a color filter, electronic paper, and a flexible display. It is suitable as a sheet. The thickness of the thin substrate here is about 5 μm to 2 mm (for example, 10 μm to 0.6 mm). In addition, the thin substrate is, for example, a resin such as polyimide, polycarbonate, polyethersulfone, polyacrylate, polyamide, polynorbornene, polyethylene terephthalate, polyethylene naphthalate, polyetheretherketone, polyamideimide, polyetherimide, polyaramid, polyphenylene sulfide, etc. It may contain at least one layer of film, stainless steel foil or the like.

  The temporary fixing sheet is typically used in a mode in which one adhesive surface is bonded to a carrier substrate made of a hard material such as glass and then the thin substrate is temporarily fixed to the other adhesive surface. . The temporary fixing sheet has an appropriate adhesiveness that does not peel off from the carrier substrate and the thin substrate during the manufacturing process of the thin substrate, and a removability that can be peeled well from the adherend after achieving the purpose of temporary fixing. Is required. In addition, it is important that the sheet is prevented from being deteriorated in properties such as adhesion to heating during pattern formation on the substrate. Specifically, a thin substrate whose back surface is temporarily fixed by the sheet is manufactured by forming a pattern on the surface. The pattern formation is usually performed at a temperature of 100 ° C. to 230 ° C. for about 1 to 3 hours. Since the resin sheet disclosed here can maintain good characteristics (typically adhesiveness) against the heating as described above, it is preferably used for the production of a thin substrate.

  As described above, the resin sheet disclosed herein is preferably applied to the use of manufacturing a thin substrate such as a circuit board (typically FPC). Therefore, according to this specification, a method for producing a thin substrate (for example, a circuit board (typically FPC), an organic EL panel, a color filter, electronic paper, a flexible display) using the resin sheet is provided. In a preferred embodiment, the manufacturing method includes a step (fixing step) of fixing a thin substrate (typically the back surface of the substrate) to a resin sheet disposed (for example, fixed) on the surface of the carrier substrate; Forming a pattern on the surface (pattern forming step). In a more preferred embodiment, the pattern forming step includes a step (heating step) of heating to 60 ° C. or higher (for example, 100 ° C. to 230 ° C.). During the heating, since the resin sheet is typically in a state where both surfaces are sandwiched between adherends, reaction inhibition due to oxygen in the atmosphere is suppressed, and the gel fraction of the adhesive resin layer is increased. Can be suitably realized.

  The manufacturing method may include a step of removing the resin sheet from the thin substrate after the heating step (removal step, typically a peeling step). In a preferred embodiment, an active energy ray (typically UV) irradiation step is performed before the removing step for the purpose of reducing the peeling (re-peeling) of the resin sheet. When this process is included, it is preferable to include a photopolymerization initiator in the adhesive resin layer. Note that other technical matters necessary for manufacturing a thin substrate such as an FPC can be implemented by those skilled in the art based on the common general technical knowledge in the field, and thus will not be described here.

  Several examples relating to the present invention will be described below, but the present invention is not intended to be limited to those shown in the examples. In the following description, “parts” and “%” are based on weight unless otherwise specified.

<Example 1>
In a reaction vessel equipped with a thermometer, a stirrer, a nitrogen introducing tube, etc., 96 parts of 2EHA, 4 parts of AA, and BPO (trade name “NIPER BW” manufactured by NOF Corporation) as a polymerization initiator are 0.3. And toluene as a polymerization solvent were added and a polymerization reaction was performed at 60 ° C. under a nitrogen gas stream to obtain a 45% toluene solution of an acrylic polymer having a weight average molecular weight (Mw) of about 600,000. This was used as an acrylic resin composition according to this example. The acrylic resin composition is coated on a PET release liner, dried at 80 ° C. for 3 minutes, and further subjected to aging at 50 ° C. for 24 hours to form an adhesive resin layer having a thickness of 30 μm. A baseless resin sheet was prepared.

<Example 2>
A substrate-less resin sheet according to this example was produced in the same manner as in Example 1 except that the monomer composition of the acrylic polymer and the amount of polymerization initiator used were changed to those shown in Table 1.

<Example 3>
In a reaction vessel equipped with a thermometer, a stirrer, a nitrogen introduction tube, etc., 2EHA 100 parts, 2-hydroxyethyl acrylate (HEA) 12.6 parts, BPO (a product made by NOF Corporation) as a polymerization initiator Acrylic polymer having a weight average molecular weight (Mw) of about 600,000 by introducing 0.25 parts of the name “Niper BW”) and toluene as a polymerization solvent and carrying out a polymerization reaction at 60 ° C. in a nitrogen gas stream. A 45% toluene solution was obtained. To this was added 13.5 parts of methacryloyloxyethyl isocyanate (MOI) to prepare an acrylic polymer having a carbon-carbon double bond. In addition, 0.1 parts of an isocyanate-based crosslinking agent (trade name “Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.) and photopolymerization are carried out in a toluene solution of the above acrylic polymer with respect to 100 parts of solid content of the acrylic polymer. Initiator (trade name “Irgacure 127” (Irg127) manufactured by Ciba Specialty Chemicals): 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl}- 2-methyl-2-propan-1-one) was added. Further, an antioxidant (trade name “IRGANOX1010” manufactured by Ciba Japan Co., Ltd .; pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate]) is used as an adhesive resin. It added in the ratio used as 0.087% in a layer. In this way, an acrylic resin composition according to this example was obtained.
The acrylic resin composition is applied onto a release liner made of PET, dried at 120 ° C. for 3 minutes, and further subjected to aging at 50 ° C. for 24 hours to form an adhesive resin layer having a thickness of 30 μm. A baseless resin sheet was prepared.

<Example 4>
As a substrate, a PET film having a thickness of 75 μm (light red solid printing manufactured by Daisan Paper Industry Co., Ltd.) was prepared. By applying the acrylic resin composition obtained in Example 3 to this base material, drying at 120 ° C. for 3 minutes, and further aging at 50 ° C. for 24 hours, an adhesive resin layer having a thickness of 30 μm is formed. A resin sheet supported on a PET film substrate was prepared.

<Example 5>
An acrylic resin composition was prepared in the same manner as in Example 3, except that the isocyanate-based crosslinking agent and the photopolymerization initiator were not used and the antioxidant content was changed to 0.089%. This acrylic resin composition is coated on a PET release liner, dried at 80 ° C. for 3 minutes, and further subjected to aging at 50 ° C. for 24 hours to form an adhesive resin layer having a thickness of 30 μm. A baseless resin sheet was prepared.

<Example 6>
In a reaction vessel equipped with a thermometer, a stirrer, a nitrogen introducing tube, etc., 22.9 parts of 2EHA, 53.1 parts of LA, 0.34 parts of AA, 11.0 parts of HEA, and BPO (NOF) as a polymerization initiator Co., Ltd. (trade name “Nyper BW”) 0.2 part and toluene as a polymerization solvent were added and a polymerization reaction was carried out at 60 ° C. under a nitrogen gas stream, and the weight average molecular weight (Mw) was about A 45% toluene solution of 600,000 acrylic polymer was obtained. An acrylic polymer having a carbon-carbon double bond was prepared by adding 11.8 parts of MOI thereto. Also, in the toluene solution of the acrylic polymer, 3 parts of an aluminum chelate crosslinking agent (trade name “Aluminum Chelate AW” manufactured by Kawasaki Fine Chemical Co., Ltd.) with respect to 100 parts of the solid content of the acrylic polymer, and photopolymerization started. 2 parts of an agent (trade name “Irgacure 127” manufactured by Ciba Specialty Chemicals) and a silane coupling agent (trade name “KBM903” manufactured by Shin-Etsu Chemical Co., Ltd .: 3-aminopropyltrimethoxysilane) 2 parts were added. Further, an antioxidant (trade name “IRGANOX1010” manufactured by Ciba Japan Co., Ltd.) was added to the adhesive resin layer at a ratio of 0.095%. In this way, an acrylic resin composition according to this example was obtained.
The acrylic resin composition is coated on a PET release liner, dried at 80 ° C. for 3 minutes, and further subjected to aging at 50 ° C. for 24 hours to form an adhesive resin layer having a thickness of 30 μm. A baseless resin sheet was prepared.

<Example 7>
A resin sheet according to this example was produced in the same manner as in Example 6 except that the drying temperature of the acrylic resin composition was changed to 120 ° C.

<Example 8>
Into a reaction vessel equipped with a thermometer, a stirrer, a nitrogen introducing tube, etc., 2EHA 100 parts, HEA 4 parts, AIBN 0.2 part as a polymerization initiator, and toluene as a polymerization solvent were charged, and nitrogen was added. A polymerization reaction was carried out at 60 ° C. in a gas stream to obtain a 45% toluene solution of an acrylic polymer having a weight average molecular weight (Mw) of about 600,000. A resin sheet according to this example was produced in the same manner as in Example 1 except that this acrylic resin composition was used.

<Example 9>
A resin sheet according to this example was produced in the same manner as in Example 3 except that the addition amount of the antioxidant was changed to 0.435%.

<Example 10>
In a reaction vessel equipped with a thermometer, a stirrer, a nitrogen introduction tube, etc., 0 parts of 2EHA, 12.6 parts of HEA, and BPO (trade name “Nyper BW” manufactured by NOF Corporation) as a polymerization initiator are 0. .25 parts and toluene as a polymerization solvent were added and a polymerization reaction was performed at 60 ° C. under a nitrogen gas stream to obtain a 45% toluene solution of an acrylic polymer having a weight average molecular weight (Mw) of about 600,000. . To this, 13.5 parts of MOI was subjected to an addition reaction to prepare an acrylic polymer having a carbon-carbon double bond. In addition, 0.1 parts of an isocyanate-based crosslinking agent (trade name “Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.) and photopolymerization are carried out in a toluene solution of the above acrylic polymer with respect to 100 parts of solid content of the acrylic polymer. 2 parts of an initiator (trade name “Irgacure 127” manufactured by Ciba Specialty Chemicals) and 2 parts of BPO (trade name “Nyper BW” manufactured by NOF Corporation) were added. Further, an antioxidant (trade name “IRGANOX1010” manufactured by Ciba Japan Co., Ltd.) was added to the adhesive resin layer at a ratio of 0.087%. In this way, an acrylic resin composition according to this example was obtained.
The acrylic resin composition is applied onto a release liner made of PET, dried at 120 ° C. for 3 minutes, and further subjected to aging at 50 ° C. for 24 hours to form an adhesive resin layer having a thickness of 30 μm. A baseless resin sheet was prepared.

<Example 11>
A substrate-less resin sheet according to this example was produced in the same manner as in Example 3 except that the monomer composition of the acrylic polymer and the amount of polymerization initiator used were changed to those shown in Table 2. In Table 2, ACMO is N-acryloylmorpholine.

<Example 12>
A substrate-less resin sheet according to this example was produced in the same manner as in Example 3 except that the monomer composition of the acrylic polymer and the amount of polymerization initiator used were changed to those shown in Table 2.

<Example 13>
Substrate-less material according to this example is the same as Example 6 except that the polymerization initiator is changed to t-hexylperoxy-2-ethylhexanoate (trade name “Perhexyl O” manufactured by NOF Corporation). A resin sheet was prepared.

<Example 14>
A substrate-less resin sheet according to this example was produced in the same manner as in Example 3 except that AIBN (0.2 part) was used instead of BPO (0.25 part) as a polymerization initiator.

  Tables 1 and 2 show the outline of the resin sheet according to each example (composition of adhesive resin layer, carbon-carbon double bond abundance, drying conditions, abundance of radical generator, gel fraction, etc.). The carbon-carbon double bond abundance is a value calculated based on the composition.

[Step following capability]
The adhesive resin composition according to each example was applied to a PET film substrate (thickness 38 μm), dried at a predetermined temperature for 3 minutes, and further subjected to aging at 50 ° C. for 24 hours, whereby a thickness of 30 μm was obtained. A resin sheet having an adhesive resin layer supported on a PET film substrate was prepared. The drying temperature was 80 ° C. for Examples 1, 2, 5, 6, 8, and 13, and 120 ° C. for Examples 3, 4, 7, 9-12, and 14. The produced resin sheet was cut into a size of 20 mm in width and 70 mm in length to produce a measurement sample.
A PET film (trade name “Lumirror S10” manufactured by Toray Industries, Inc.) having a thickness of 25 μm was placed on a glass plate (an alkali glass plate manufactured by Matsunami Glass Industry Co., Ltd.) to provide a step on the glass surface. In an environment of 23 ° C. and 50% RH, the above step portion is positioned so as to be substantially in the center in the width direction of the measurement sample, and the adhesive resin layer side surface of the measurement sample is placed on the adherend surface with a 2 kg rubber roller. Was reciprocated once and crimped. 30 minutes after the pressure bonding, the stepped portion of the adherend to which the measurement sample was attached was observed from directly above, and the size (maximum length) of the void existing in the stepped portion at the adherend interface was confirmed. The gap size was confirmed using an optical microscope (magnification: 100 times), and the maximum diameter (maximum length) of the gap existing in the step portion was recorded. As the optical microscope, “MX50” manufactured by Olympus Corporation was used. The results are shown in Tables 1 and 2.

[Peel strength after heating]
The adhesive resin composition according to each example was applied to a PET film substrate (thickness: 75 μm), dried at a predetermined temperature for 3 minutes, and further subjected to aging at 50 ° C. for 24 hours to obtain a thickness of 30 μm. A resin sheet having an adhesive resin layer supported on a PET film substrate was prepared. The drying temperature was 80 ° C. for Examples 1, 2, 5, 6, 8, and 13, and 120 ° C. for Examples 3, 4, 7, 9-12, and 14.
The resin sheet produced above was cut into a size of 20 mm in width and 100 mm in length to produce a measurement sample. Under an environment of 23 ° C. and 50% RH, the adhesive resin layer side surface of the measurement sample was pressure-bonded by reciprocating a 2 kg rubber roller to the surface of the glass plate. This was left in the same environment for 30 minutes, and then heated at 150 ° C. for 30 minutes in a dryer. Then, in an environment of 23 ° C. and 50% RH, using a tensile tester, in accordance with JIS Z0237: 2000, peel strength (N / 20 mm width) at a peel angle of 180 degrees and a tensile speed of 300 mm / min. Was measured. For Examples 3, 4, 6, 7, and 9-14, after heating, 60 mW / cm ² × 10 using a UV irradiator (manufactured by Nitto Seiki Co., Ltd., trade name “NEL SYSTEM UM810”, high pressure mercury lamp light source). Second UV irradiation was performed.
In addition, as a PET film base material, the PET film (thickness 75 micrometer thin red solid printing) by Daisan Paper Industry Co., Ltd. was used. As the glass plate, an alkali glass plate (80 mm × 80 mm × 0.7 mm) manufactured by Matsunami Glass Industry Co., Ltd. was used. As the tensile tester, a variable-angle peel tester (trade name “Yamamoto-type variable-angle peel measuring machine YM-121” manufactured by Asahi Seiko Co., Ltd.) was used. The results are shown in Tables 1 and 2.

[Evaluation of bubble generation during heating]
In an environment of 23 ° C. and 50% RH, the adhesive resin layer side surface of the resin sheet according to each example was bonded to the surface of the glass plate using a hand roller, and then cut into a size of 80 mm × 80 mm. A measurement sample was prepared. As the glass plate, an alkali glass plate (80 mm × 80 mm × 0.7 mm) manufactured by Matsunami Glass Industry Co., Ltd. was used. This was left in the same environment for 30 minutes, and then heated at 150 ° C. for 30 minutes in a dryer. About the base material-less resin sheets according to Examples 1 to 3, 5 to 8 and Examples 9 to 14, a PEN film (trade name manufactured by Teijin DuPont Films Co., Ltd.) having a thickness of 125 μm on the surface opposite to the glass plate side. The above-mentioned heating was performed after bonding “Teonex Q65FA”). The appearance change after heating (the presence or absence of generation of bubbles at the adherend interface) was visually observed and evaluated according to the following criteria. The results are shown in Tables 1 and 2.
A: The presence of bubbles was not recognized.
A: Microbubbles having a maximum diameter of less than 2.0 mm were observed.
X: Bubbles having a maximum diameter of 2.0 mm or more were observed.

Table 1, as shown in Table 2, the ratio _(G B / G _A) is Example 1 Example 7 was 1.1 to 10,000, the resin sheets of Examples 9 to Example 13, the generation of bubbles upon heating Was not observed, or only microbubbles having a maximum diameter of less than 2.0 mm were generated. On the other hand, the ratio _(G B _/ G _A) is Example 8 which was less than 1.1, the resin sheets of Examples 14, bubbles are generated at the interface between the adherend upon heating, peeling the entire surface was observed . From these results, by setting the ratio (G _B / G _A ) in the range of 1.1 to 10000, it adheres well to the adherend before heating and there are few voids at the adherend interface, and During heating, the gel fraction of the adhesive resin layer rises earlier than the vaporization and expansion of the outgas component in the adhesive resin layer, thereby suppressing the vaporization and expansion of the outgas component and preventing the occurrence of problems such as floating and peeling. I understand that.
From another viewpoint, the bubble suppression during heating by the resin sheets according to Examples 1 to 7 and Examples 9 to 13 was that the gel fraction before heating was relatively low, and the gel fraction after heating. G _B can also be interpreted as being realized by ranged from 30% to 100%.
Furthermore, the resin sheets according to Example 3 to Example 7, Example 9 to Example 11, and Example 13 were remarkably suppressed in the generation of bubbles during heating, and the peeling after heating was more favorable. It can be seen that good adhesion can be achieved and the removability is excellent. In particular, the resin sheets according to Examples 3 to 5, Example 9, and Example 10 were excellent in the step following ability.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

1, 2, 3, 4, 5, 6 Resin sheet 10 Base material 21, 22 Adhesive resin layer 31, 32 Release liner

Claims (8)

Characteristic (A1): The gel fraction increases by heating at 120 ° C. for 5 minutes, and the gel fraction G _B (% after the heating with respect to the gel fraction G _A (%) before the heating is performed. ratio) _(G B / G _a) is in the range of from 1.1 to 10,000; comprising the adhesion resin layer satisfying the resin sheet. Characteristics (A2): 120 ℃, the gel fraction is increased by heating for 5 minutes, and the gel fraction G _B after the said heating is in the range of 30% to 100%; meet the adhesion resin A resin sheet comprising a layer.   Characteristic (B): 180 degree peel strength measured after affixing the adhesive resin layer on a glass plate and heating at 150 ° C. for 30 minutes is 0.05 to 5.0 N / 20 mm; Item 3. The resin sheet according to Item 1 or 2.   The resin sheet as described in any one of Claims 1-3 whose content rate of the radical scavenger in the said adhesive resin layer is 1 weight% or less.   The resin sheet according to any one of claims 1 to 4, wherein a carbon-carbon double bond is present in the adhesive resin layer.   The resin sheet according to claim 5, wherein the abundance of the carbon-carbon double bond in the adhesive resin layer is 0.1 to 2.0 mmol / g. The adhesive resin layer has the general formula (1):

(In said formula, R is hydrogen or a methyl group.) The resin sheet as described in any one of Claims 1-6 containing the compound which has a heat-reactive group represented by these.   The resin sheet according to any one of claims 1 to 7, further comprising a resin film substrate that supports the adhesive resin layer.

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