Resin composition and adhesive tape

Abstract

Disclosed are: a resin composition that comprises an alkenyl group-containing silicone raw rubber, an MQ resin, a crosslinking agent, a platinum catalyst and an organic peroxide, that has a gel fraction of 45-60% after crosslinking, and that has a storage modulus of 100,000-1,000,000Pa at a temperature of 200°C after crosslinking; and an adhesive tape having an adhesive agent layer formed from said resin composition after crosslinking, wherein the adhesive agent layer has a gel fraction of 45-60%, the adhesive agent layer has a storage modulus of 100,000-1,000,000Pa at a temperature of 200°C, and the adhesive agent layer has a thickness of 2-10μm.

Description

Technical Field

[0001] The present invention relates to a resin composition and an adhesive tape having excellent dimensional stability and suppressed adhesive residue when used, for example, in the manufacturing process of electronic components and semiconductor components.

Background Art

[0002] Silicone-based adhesive compositions are excellent in heat resistance, cold resistance, weather resistance, electrical insulation, and chemical resistance. Further, an adhesive tape having a silicone-based adhesive layer is less likely to have adhesive residue when peeled even when used particularly in a high-temperature environment. Therefore, such adhesive tapes are widely used for applications such as protection, masking, temporary fixing, fixing during transportation, splicing, etc. of members and components in the manufacturing process of, for example, electric and electronic components and semiconductor components.

[0003] In the manufacturing process of these electric and electronic components and semiconductor components, a high load and a high-temperature environment may occur for molding the components. For example, in the manufacturing process of a printed laminated board, a fiber-reinforced prepreg impregnated with an uncured resin as an adhesive layer is laminated between circuit laminated boards having a circuit pattern formed on the surface, and heated and pressed with a laminating press at a high temperature (for example, 180° C. or higher), a high pressure (for example, 20 kg / cm , ,

[0001] ,

[0004] ,

[0003] , , , , , 2 ,

[0002] , , , or higher) for a long time (for example, 2 hours or longer). In such a heating and pressing process, it is necessary to protect the surface of the laminated board with a tape or the like in order to prevent the formation of scratches on the circuit on the surface of the laminated board and the adhesion of the uncured resin.

[0004] When conventional adhesive tapes with a silicone-based adhesive layer are used in high-temperature, high-pressure, and long-duration heating and pressing processes, the adhesive layer is pushed out by the pressure, causing a change in its dimensions. This results in adhesive overflow from the edges of the tape, leaving adhesive residue after the tape is removed. Furthermore, during such processes, the adhesive is pressed against the substrate while being heated at high temperatures. Consequently, the adhesive, softened by the high temperature, bonds more strongly to the substrate, and the adhesive degrades due to the high temperature, reducing its cohesive force. As a result, when the tape is removed after the heating and pressing process, the bonding force between the substrate and the adhesive overcomes the cohesive force of the adhesive layer, causing cohesive failure of the adhesive layer and resulting in adhesive residue.

[0005] Adhesive residue caused by dimensional changes in the adhesive during the heating and pressing process can generally be reduced by thinning the thickness of the adhesive layer of the tape. However, thinning the adhesive layer reduces the cohesive force in the thickness direction, which may result in adhesive residue when peeling the tape after the process. On the other hand, increasing the thickness of the adhesive layer reduces dimensional stability, which may increase adhesive leakage during heating and pressing. Thus, dimensional stability during high-temperature processes (prevention of adhesive leakage) and prevention of adhesive residue after high-temperature processes are mutually exclusive characteristics, and achieving both simultaneously is difficult.

[0006] Patent Document 1 discloses a porous fluororesin sheet for use as a release protection sheet between a circuit fixing jig and a laminated circuit board in a lamination pressing process for printed circuit boards. However, this release protection sheet does not have an adhesive layer and is therefore not an adhesive tape. In other words, it does not have the ability to fix to specific locations, so it is not possible to selectively mask the area to be protected. Therefore, when using this release protection sheet, it is necessary to use it over the entire surface to be protected, which is disadvantageous in terms of cost.

[0007] Patent Document 2 discloses an adhesive tape having at least a fluororesin-based film and an adhesive layer to form a release surface. However, this adhesive tape is a release adhesive tape, and dimensional stability during high-temperature processes and adhesive residue have not been considered. Furthermore, the heating and pressing test conditions for this adhesive tape were 150°C and a pressure of 5 kg / cm². 2 The press duration is 20 minutes, and all of these conditions are less stringent than those of a typical heating press process, such as the heating press process for laminated substrates.

[0008] Patent Document 3 discloses a silicone-based pressure-sensitive adhesive composition containing both a siloxane-based crosslinking agent having an SiH group and a peroxide-based crosslinking agent as crosslinking agents. However, in this silicone-based pressure-sensitive adhesive composition, the peroxide-based crosslinking agent remains unreacted in the composition until it is used in the process. Therefore, it is assumed that the peroxide-based crosslinking agent will gradually react during the process leading up to use, such as manufacturing, storage, shipping, transportation, and storage at the customer's location. In other words, its properties will change by the time it is actually used in the process, which is disadvantageous in terms of long-term stability. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 04-179520 [Patent Document 2] International Publication No. 2016 / 174713 [Patent Document 3] Japanese Patent Publication No. 2002-275450 [Overview of the project] [Problems that the invention aims to solve]

[0010] The inventors of the present invention have diligently studied to solve problems related to dimensional stability and adhesive residue of adhesive tapes, particularly in applications where they are used under high load and high temperature conditions, which are among the properties required for adhesive tapes. In other words, the object of the present invention is to provide a resin composition and adhesive tape that have excellent dimensional stability when used under high load and high temperature conditions, and that suppress adhesive residue when peeled off after use in high load and high temperature conditions. [Means for solving the problem]

[0011] As a result of diligent research to achieve the above objective, the inventors of this invention discovered that a resin composition having specific components and specific physical properties is extremely effective, and thus completed the present invention.

[0012] In other words, the present invention comprises a silicone raw rubber containing alkenyl groups, MQ resin, a crosslinking agent, a platinum catalyst, and an organic peroxide. The gel fraction after crosslinking is between 45% and 60%. This is a resin composition having a storage modulus at 200°C after crosslinking that is between 100,000 Pa and 1,000,000 Pa.

[0013] Furthermore, the present invention relates to an adhesive tape having an adhesive layer composed of the resin composition after crosslinking, The gel fraction of the adhesive layer is 45% or more and 60% or less. The storage modulus of the adhesive layer at 200°C is 100,000 Pa or more and 1,000,000 Pa or less, and The adhesive tape has an adhesive layer thickness of 2 μm or more and 10 μm or less. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a resin composition and adhesive tape that exhibit excellent dimensional stability when used in high-load and high-temperature environments, and that suppress adhesive residue when peeled off after use in high-load and high-temperature environments.

[0015] Since the resin composition of the present invention has the above-mentioned effects, it is particularly useful as a material for use in the adhesive layer of adhesive tapes. Furthermore, since the adhesive tape of the present invention has the above-mentioned effects, it is very useful for applications such as protecting, masking, and temporarily fixing adherends in the manufacturing process of electrical and electronic components and semiconductors (especially the hot pressing process). [Modes for carrying out the invention]

[0016] <Resin composition> The resin composition of the present invention comprises a silicone raw rubber containing alkenyl groups, MQ resin, a crosslinking agent, a platinum catalyst, and an organic peroxide. This resin composition is particularly useful as an adhesive composition (i.e., an addition-curing silicone-based adhesive composition). However, the resin composition of the present invention is not limited to this and may be used for various other applications.

[0017] The gel fraction of the resin composition of the present invention after crosslinking is 45% to 60%. If this gel fraction is less than 45%, the storage modulus of the molten resin composition heated at high temperatures decreases, and adhesive leakage tends to occur. Also, the adhesion between the resin composition and the adherend increases, and the cohesive force of the resin composition decreases, which tends to result in adhesive residue. On the other hand, if this gel fraction exceeds 60%, the silicone raw rubber in the resin composition undergoes oxidative cleavage when heated at high temperatures, which decreases the cohesive force of the resin composition and tends to result in adhesive residue. While a gel fraction of 45% to 60% is acceptable, it is more preferably 50% to 60%. The specific method for measuring the gel fraction is described in the Examples section below.

[0018] The storage modulus of the resin composition of the present invention at 200 °C after crosslinking is 100,000 Pa or more and 1,000,000 Pa or less. If this storage modulus is less than 100,000 Pa, the elasticity of the resin composition in the molten state heated at high temperature decreases. For example, in a high load and high temperature process such as a hot press process, the shape of the resin composition once deformed does not return well to its original state, and there is a tendency for paste leakage to occur. It is sufficient that this storage modulus is 100,000 Pa or more and 1,000,000 Pa or less, but it is more preferably 100,000 or more and 400,000 or less. The specific measurement method of the storage modulus is described in the column of the examples described later.

[0019] The silicone raw rubber containing an alkenyl group used in the present invention is typically a long-chain polymer of polydimethylsiloxane having a structure composed of D units [(CH3)2SiO], and is a polymer containing at least 2 alkenyl groups per molecule. However, the present invention is not limited to this, and other types of silicone raw rubber may be used.

[0020] The MQ resin used in the present invention is typically a polymer of a silicone resin having a three-dimensional structure composed of M units [(CH3)3SiO 1 / 2 and Q units [SiO2]. However, the present invention is not limited to this, and other types of MQ resins may be used.

[0021] The crosslinking agent used in the present invention is typically a polyorganosiloxane containing at least 2 SiH groups per molecule. However, the present invention is not limited to this, and other types of crosslinking agents may be used.

[0022] A resin composition containing a silicone raw rubber containing alkenyl groups, MQ resin, and a crosslinking agent, as described above, is generally known as an addition-curing silicone adhesive. An addition-curing silicone adhesive, for example, comprises a main component made of silicone raw rubber containing alkenyl groups, MQ resin, and a crosslinking agent made of a polyorganosiloxane containing SiH groups. This addition-curing silicone adhesive hardens by heating under a platinum catalyst to induce a crosslinking reaction. It is known that basic adhesive properties such as adhesive strength, holding power, and tack can be adjusted by changing the ratio of silicone raw rubber to MQ resin in this addition-curing silicone adhesive.

[0023] Various methods are known for adjusting the gel fraction of addition-curing silicone adhesives. For example, lowering the blending ratio of MQ resin to raw silicone rubber, increasing the content of alkenyl groups in the raw silicone rubber (and / or MQ resin), or increasing the amount of crosslinking agent added tends to increase the gel fraction after crosslinking. On the other hand, adding non-crosslinking components (e.g., silicone oil) tends to decrease the gel fraction.

[0024] Various methods are known for adjusting the storage modulus of addition-curing silicone adhesives. For example, increasing the molecular weight of the silicone rubber, increasing the crosslinking density, or decreasing the blending ratio of MQ resin to the silicone rubber tends to increase the storage modulus.

[0025] To obtain the resin composition of the present invention exhibiting a specific gel fraction and storage modulus, the above-described preparation methods can be used. However, the resin composition of the present invention is not limited to those obtained by such preparation methods.

[0026] The resin composition of the present invention further contains a platinum catalyst. The platinum catalyst is a component that is activated by heating and promotes the crosslinking reaction. The type and amount of platinum catalyst used are not particularly limited, and various platinum catalysts known to be usable as addition-curing silicone adhesives and their amounts can be used. In other words, in the present invention, for example, a commercially available platinum catalyst (curing catalyst for addition-curing silicone adhesives) can be used in an appropriate amount.

[0027] The resin composition of the present invention further contains an organic peroxide. According to the inventors' findings, this organic peroxide is effective not only for general properties but also for exhibiting the effects of the present invention (such as suppression of adhesive residue). While the reason for this is not entirely clear, one possible reason is that the free oxygen radicals generated by the decomposition of the organic peroxide participate in the crosslinking reaction, suitably affecting the crosslink density and other properties. Furthermore, the gel fraction and storage modulus can be adjusted by changing the content of the organic peroxide.

[0028] The type of organic peroxide is not particularly limited; any peroxide that decomposes to generate free oxygen radicals is acceptable. Dibenzoyl peroxide and its derivatives are particularly preferred. Specific examples include dibenzoyl peroxide, 4,4'-dimethyldibenzoyl peroxide, 3,3'-dimethyldibenzoyl peroxide, 2,2'-dimethyldibenzoyl peroxide, 2,2',4,4'-tetrachlorodibenzoyl peroxide, and cumyl peroxide. The organic peroxide may be used alone or in combination of two or more types.

[0029] Free oxygen radicals are generated by the decomposition of organic peroxides. Their theoretical amount (i.e., the theoretical amount of reactive oxygen species from organic peroxides) is calculated using the following formula (1). A(%) = (B × 16 / M) × 100 (1) [In formula (1), A represents the theoretical amount of reactive oxygen species of the organic peroxide, B represents the number of peroxide bonds, and M represents the molecular weight of the organic peroxide.]

[0030] In the present invention, the amount of organic peroxide is not particularly limited and can be appropriately determined according to various conditions such as the curing temperature, the decomposition temperature of the organic peroxide, the ratio of silicone raw rubber to MQ resin, and the molecular weight of the silicone component. However, the product PA of the amount of organic peroxide P (parts by mass) and the theoretical amount of active oxygen A (%) of the organic peroxide represented by formula (1) above, per 100 parts by mass of the total of the alkenyl group-containing silicone raw rubber, MQ resin, and crosslinking agent described above, is preferably 0.06 parts by mass or more, and more preferably 0.10 parts by mass or more and 0.30 parts by mass or less. The gel fraction and storage modulus can also be adjusted by changing this product PA.

[0031] Each of the components described above can be obtained, for example, as commercially available products. For example, the resin composition of the present invention can also be obtained by adding predetermined amounts of a commercially available platinum catalyst and organic peroxide to a commercially available addition-curing silicone adhesive. However, it is necessary to appropriately adjust the composition and other conditions so that the gel fraction and storage modulus are within the range of the present invention. By crosslinking and curing this, a resin composition containing a crosslinked silicone structure is obtained, and this is how the effects of the present invention are achieved. The crosslinking and curing reaction is usually carried out by heating. However, depending on the type of component, crosslinking and curing can also be performed by ultraviolet irradiation.

[0032] The resin composition of the present invention can also be obtained, for example, using a mixture of two or more commercially available silicone adhesives, a commercially available platinum catalyst, and an organic peroxide. Specifically, for example, the resin composition of the present invention can be obtained by mixing a silicone adhesive with a relatively high gel fraction and storage modulus with a silicone adhesive with a relatively low gel fraction and storage modulus in an appropriate ratio, and then blending it with a platinum catalyst and an appropriate amount of organic peroxide. However, the resin composition of the present invention is not limited to those obtained by this method.

[0033] Additives may be added to the resin composition of the present invention for the purpose of improving various properties. Specific examples of additives include inorganic fillers such as carbon black and silica; polyorganosiloxanes such as silicone resin, polydimethylsiloxane, and polydimethylphenylsiloxane; antioxidants such as phenolic antioxidants and amine antioxidants; and silane coupling agents.

[0034] <Adhesive tape> The adhesive tape of the present invention is an adhesive tape having an adhesive layer composed of the resin composition of the present invention after crosslinking. This adhesive tape may be an adhesive tape having the adhesive layer on one or both sides of a base film, or it may be a baseless type adhesive tape without a base. Alternatively, it may be a double-sided adhesive tape having an adhesive layer composed of the resin composition of the present invention after crosslinking on one side of the base film, and another adhesive layer (conventional adhesive layer) on the other side.

[0035] The thickness of the adhesive layer of the adhesive tape is 2 μm to 10 μm, preferably 4 μm to 8 μm. By setting the thickness of the adhesive layer to 2 μm to 10 μm, dimensional stability is improved and adhesive residue tends to be suppressed when used in high-load and high-temperature environments.

[0036] The adhesive layer can be formed by crosslinking and curing the resin composition of the present invention. For example, the resin composition can be applied to a substrate and crosslinked and cured by heating or ultraviolet irradiation to form an adhesive layer on the substrate. Alternatively, the resin composition can be applied to release paper or other film and crosslinked and cured by heating or ultraviolet irradiation to form an adhesive layer, and this adhesive layer can be bonded to one or both sides of the substrate. A baseless type adhesive tape can be manufactured by forming an adhesive layer on release paper or other film, and then bonding another release paper or other film on top of the adhesive layer.

[0037] To reduce the viscosity of the resin composition during application, a solvent may be added. Specific examples of solvents include aromatic solvents such as toluene and xylene; aliphatic solvents such as hexane, octane, and isoparaffin; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; ester solvents such as ethyl acetate and isobutyl acetate; and ether solvents such as diisopropyl ether and 1,4-dioxane.

[0038] The coating method is not particularly limited, and any known method may be used. Specific examples include coating using a comma coater, lip coater, roll coater, die coater, knife coater, blade coater, rod coater, kiss coater, or gravure coater; screen coating; dip coating; and cast coating.

[0039] The substrate is not particularly limited, but a film-like substrate is preferred. In particular, a heat-resistant resin film that can be processed at high temperatures is preferred. Specific examples include resin films such as polyimide (PI), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyether ether ketone (PEEK), polyethylene sulfide (PPS), and polytetrafluoroethylene (PTFE). These films can be used as single layers or laminated films of two or more layers. Among these, polyimide films are preferred. The thickness of the substrate is not particularly limited, but is preferably 5 to 200 μm, more preferably 5 to 125 μm.

[0040] Furthermore, the surface of the substrate on which the adhesive layer is applied may be subjected to an easy-adhesion treatment as needed. Examples of easy-adhesion treatments include primer treatment, corona treatment, etching treatment, plasma treatment, and sandblasting treatment.

[0041] The adhesive tape of the present invention may be provided with a release liner. The release liner is used to protect the adhesive layer of the adhesive tape and is peeled off immediately before application to expose the adhesive and allow the adhesive tape to be applied to the substrate. The type of release liner is not particularly limited, and known release liners can be used. Specific examples include those made by treating the surface of a substrate such as high-quality paper, glassine paper, or synthetic resin film with a release agent. For the release agent treatment, a release agent such as a fluorine-substituted alkyl-modified silicone resin may be used. In particular, as a release liner laminated on a silicone-based adhesive layer, a polyethylene terephthalate film whose surface is treated with a fluorine-substituted alkyl-modified silicone resin is preferred. Furthermore, if the adhesive strength of the adhesive layer is low, an untreated resin film may be used as a release liner. Specific examples include polyethylene terephthalate (PET) film, polyethylene (PE) film, and polypropylene (PP) film. [Examples]

[0042] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to these examples. In the following description, "parts" means "parts by mass".

[0043] <Example 1> First, several prototypes (A-F) of addition-curing silicone adhesives (undiluted solution) were prepared. These prototypes were adjusted so that the cured storage modulus G' and gel fraction, measured by the method described later, exhibited various values. All of these prototypes are silicone adhesives consisting of raw silicone rubber containing alkenyl groups, MQ resin, and a crosslinking agent.

[0044] In Example 1, among these multiple prototypes, an addition-curing type silicone adhesive (A) (solid content concentration 60%) was selected, in which the storage modulus G' and gel fraction after curing, when an appropriate amount of organic peroxide is added, result in specific values ​​described later.

[0045] Then, 100 parts of this addition-curing silicone adhesive stock solution (A), 197 parts of toluene as a diluent, 3.0 parts of an organic peroxide-type curing agent manufactured by NOF Corporation (NIPER® BMT-K40, organic peroxide concentration: 40%, theoretical amount of active oxygen in organic peroxide: 6.05%) as an organic peroxide, and 0.3 parts of a platinum catalyst (NC-25, manufactured by Dow-Toray Corporation) were uniformly mixed to obtain adhesive solution (1). In this adhesive solution (1), the product PA of the amount of organic peroxide P and the theoretical amount of active oxygen A of the organic peroxide per 100 parts of silicone adhesive is 0.12 parts.

[0046] When dynamic viscoelasticity measurements were performed on this adhesive liquid (1), as described later, the storage modulus G' at 200°C was found to be 168628 Pa. Furthermore, when gel fraction measurements were performed on this adhesive liquid (1), as described later, the gel fraction was found to be 46%.

[0047] Next, adhesive solution (1) was applied to one side of a 25 μm thick polyimide (PI) film that had been primer-treated, so that the adhesive layer would be 6 μm thick after drying. The film was then dried in a drying oven at 60°C for 1 minute to remove the solvent, and then heated and cured at 200°C for 1 minute to form the adhesive layer. Finally, a 50 μm thick polyethylene terephthalate (PET) film, which had been released with a fluorine-substituted alkyl-modified silicone resin, was laminated to the adhesive layer as a release liner to obtain an adhesive tape.

[0048] [Dynamic viscoelasticity measurement] The adhesive liquid (1) is applied to the release liner so that its thickness after drying is 50 μm. Then, it is dried in a drying oven at 60°C for 1 minute to remove the solvent. Next, the silicone component is cured by heating at 200°C for 1 minute to form an adhesive layer consisting of the cured silicone-based adhesive composition. By repeating this operation multiple times, a laminate of adhesive layers with a thickness of 2 mm is formed, which is used as the sample for measurement.

[0049] The sample to be measured is placed between parallel discs (φ8 mm), and the storage modulus G' is measured in the range of -60°C to 300°C using a dynamic viscoelasticity analyzer (Rheometric Scientific, RDAIII) while applying a shear strain at a frequency of 10 Hz and heating at a rate of 10°C / min.

[0050] [Gel fraction measurement] The adhesive liquid (1) is applied to the release liner so that its thickness after drying is 50 μm. Then, it is dried in a drying oven at 60°C for 1 minute to remove the solvent. Finally, the silicone component is cured by heating at 200°C for 1 minute to form an adhesive layer consisting of the cured silicone-based adhesive composition, which is used as the sample for measurement.

[0051] The obtained sample was cut into 50 mm x 50 mm pieces, the release liner was peeled off, and a measurement sample consisting of a sheet-like silicone adhesive composition was obtained. This measurement sample was then immersed in toluene at a volume of 250 times or more of the initial mass (X) at room temperature (23°C) for 1 day to swell. After immersion, the measurement sample was removed and dried in a 130°C dryer for 2 hours to remove the absorbed solvent, and the dry mass (Y) (= mass of the dried silicone adhesive composition) was measured. The gel fraction of the silicone adhesive composition was obtained by the following formula. Gel fraction (%) = (Y / X) × 100%

[0052] <Example 2> Adhesive solution (2) was prepared in the same manner as in Example 1, except that a mixture of 50 parts of addition-curing silicone adhesive solution (A) (solid content concentration 40%) and 50 parts of addition-curing silicone adhesive solution (B) (solid content concentration 40% by mass) was used instead of 100 parts of addition-curing silicone adhesive solution (A) (solid content concentration 60%), and the amount of organic peroxide was changed to 2.5 parts. An adhesive tape was then made using this adhesive solution (2). In adhesive solution (2), the product PA of the amount of organic peroxide P and the theoretical amount of active oxygen A of the organic peroxide was 0.12 parts. Dynamic viscoelasticity measurements and gel fraction measurements were performed on adhesive solution (2), and the storage modulus G' at 200°C was 124121 Pa, and the gel fraction was 55%.

[0053] <Example 3> An adhesive solution (3) was prepared in the same manner as in Example 2, except that the amount of organic peroxide was changed to 4.5 parts by mass, and an adhesive tape was made. In adhesive solution (3), the product PA of the amount of organic peroxide P and the theoretical amount of active oxygen A of the organic peroxide was 0.22 parts. Dynamic viscoelasticity measurements and gel fraction measurements were performed on adhesive solution (3), and the storage modulus G' at 200°C was 219861 Pa, and the gel fraction was 60%.

[0054] <Comparative Example 1> Adhesive solution (C1) was prepared in the same manner as in Example 2, except that the amount of addition-curing silicone adhesive stock solution (A) was changed to 25 parts, the amount of addition-curing silicone adhesive stock solution (B) to 75 parts, and the amount of organic peroxide to 2.25 parts. An adhesive tape was then made. In adhesive solution (C1), the product PA of the amount of organic peroxide P and the theoretical amount of active oxygen A of the organic peroxide was 0.12 parts. Dynamic viscoelasticity measurements and gel fraction measurements were performed on adhesive solution (C1), and the storage modulus G' at 200°C was 125270 Pa, and the gel fraction was 62%.

[0055] <Comparative Example 2> Adhesive solution (C2) was prepared in the same manner as in Example 1, except that 100 parts of addition-curing silicone adhesive stock solution (B) (solid content concentration 40%) were used instead of 100 parts of addition-curing silicone adhesive stock solution (A) (solid content concentration 60%), and the amount of organic peroxide was changed to 2 parts. An adhesive tape was then made. In adhesive solution (C2), the product PA of the amount of organic peroxide P and the theoretical amount of reactive oxygen species A of the organic peroxide was 0.12 parts. Dynamic viscoelasticity measurements and gel fraction measurements were performed on adhesive solution (C2), and the storage modulus G' at 200°C was 136757 Pa, and the gel fraction was 69%.

[0056] <Comparative Example 3> An adhesive solution (C3) was prepared in the same manner as in Example 2, except that an organic peroxide was not added, and an adhesive tape was made. In the adhesive solution (C3), the product PA of the amount of organic peroxide P and the theoretical amount of reactive oxygen species A of the organic peroxide was 0 parts. Dynamic viscoelasticity measurements and gel fraction measurements were performed on the adhesive solution (C3), and the storage modulus G' at 200°C was 240508 Pa, and the gel fraction was 53%.

[0057] <Comparative Example 4> In Example 1, adhesive solution (C4) was prepared in the same manner as in Example 1, except that a mixture of 25 parts of addition-curing silicone adhesive solution (C) (solid content concentration 90% by mass) and 75 parts of addition-curing silicone adhesive solution (D) (solid content concentration 90% by mass) was used instead of 100 parts of addition-curing silicone adhesive solution (A) (solid content concentration 60%), and the amount of organic peroxide was changed to 4.5 parts. An adhesive tape was then made using this adhesive solution (C4). In adhesive solution (C4), the product PA of the amount of organic peroxide P and the theoretical amount of active oxygen A of the organic peroxide was 0.12 parts. Dynamic viscoelasticity measurements and gel fraction measurements were performed on adhesive solution (C4), and the storage modulus G' at 200°C was 17620 Pa, and the gel fraction was 48%.

[0058] <Comparative Example 5> Adhesive solution (C5) was prepared in the same manner as in Example 1, except that 100 parts of addition-curing silicone adhesive stock solution (E) (solid content concentration 60% by mass) were used instead of 100 parts of addition-curing silicone adhesive stock solution (A) (solid content concentration 60%), and an adhesive tape was made. In adhesive solution (C5), the product PA of the amount of organic peroxide P and the theoretical amount of active oxygen A of the organic peroxide was 0.12 parts. Dynamic viscoelasticity measurements and gel fraction measurements were performed on adhesive solution (C5), and the storage modulus G' at 200°C was 98880 Pa, and the gel fraction was 44%.

[0059] <Comparative Example 6> An adhesive solution (C6) was prepared in the same manner as in Comparative Example 5, except that an organic peroxide was not added, and an adhesive tape was made. In the adhesive solution (C6), the product PA of the amount of organic peroxide P and the theoretical amount of reactive oxygen species A of the organic peroxide was 0 parts. Dynamic viscoelasticity measurements and gel fraction measurements were performed on the adhesive solution (C6), and the storage modulus G' at 200°C was 69702 Pa, and the gel fraction was 34%.

[0060] <Comparative Example 7> Adhesive solution (C7) was prepared in the same manner as in Comparative Example 6, except that 100 parts of addition-curing silicone adhesive stock solution (F) (solid content concentration 60% by mass) were used instead of 100 parts of addition-curing silicone adhesive stock solution (E) (solid content concentration 60% by mass), and an adhesive tape was made. In adhesive solution (C7), the product PA of the amount of organic peroxide P and the theoretical amount of active oxygen A of the organic peroxide was 0 parts. Dynamic viscoelasticity measurements and gel fraction measurements were performed on adhesive solution (C7), and the storage modulus G' at 200°C was 69045 Pa, and the gel fraction was 44%.

[0061] <Reference example 1> The adhesive tape was prepared in the same manner as in Example 2, except that the thickness of the adhesive layer was changed to 13 μm.

[0062] The adhesive tapes of the above examples and comparative examples were evaluated as follows. The results are shown in Table 1.

[0063] [Measurement of adhesive overflow after heat pressing and adhesive residue after peeling] Adhesive tape cut to 20mm x 20mm was attached to a Cu plate (Cl100p) whose surface had been polished with Pikaru liquid (manufactured by Nippon Polishing Industry Co., Ltd.), and then pressed down by passing it back and forth once with a roller covered with a 2kg rubber layer. This was then left in a 23°C environment for 20 minutes to 1 hour to obtain a bonded sample for measurement. This sample was sandwiched between two SUS304 plates, both sides of which were mirror-finished, and subjected to a temperature of 200°C and a pressure of 30kg / cm². 2The samples were heated and pressed for 4 hours. The excess adhesive after heating and pressing, and the adhesive residue after peeling off the tape, were observed at 100x magnification using a microscope (VHX-6000, manufactured by Keyence Corporation) and evaluated according to the following criteria. (Glue overflow after heat pressing) "〇": No glue leakage was observed from the four sides or corners. "×": Glue leakage was observed from all four sides or corners. (Adhesive residue after heat pressing) ○: No adhesive residue was observed on the applied surface. ×: Adhesive residue was observed on the adhesive surface.

[0064] [Table 1]

[0065] <Evaluation Results> As shown in Table 1, the adhesive tapes of Examples 1 to 3 did not exhibit any adhesive residue or excess adhesive after heat pressing at 200°C.

[0066] Comparative Examples 1 and 2 are examples where the gel fraction after crosslinking of the adhesive composition was too high. As a result, adhesive residue was left on the adhesive tapes of Comparative Examples 1 and 2.

[0067] Comparative Example 3 is an example in which organic peroxides were not used in the adhesive composition. As a result, adhesive residue was left on the adhesive tape of Comparative Example 3.

[0068] Comparative Example 4 is an example where the storage modulus of the adhesive composition after crosslinking is too low. As a result, adhesive oozing and residue occurred in the adhesive tape of Comparative Example 4.

[0069] Comparative Example 5 is an example where the gel fraction and storage modulus of the adhesive composition after crosslinking were too low. As a result, adhesive oozing and residue occurred in the adhesive tape of Comparative Example 4.

[0070] Comparative Examples 6 and 7 are examples in which organic peroxides were not used in the adhesive composition, and the gel fraction and storage modulus of the adhesive composition after crosslinking were too low. As a result, adhesive overflow and adhesive residue occurred in the adhesive tapes of Comparative Examples 6 and 7.

[0071] Reference Example 1 is an example where the adhesive layer is too thick. As a result, adhesive overflow and residue occurred in the adhesive tape of Reference Example 1. From this result, it can be understood that when using the resin composition (adhesive composition) of the present invention for the adhesive layer of adhesive tape, it is preferable that the thickness of the adhesive layer be relatively thin. [Industrial applicability]

[0072] The resin composition of the present invention is particularly useful as a material for forming the adhesive layer of adhesive tapes, for example. The adhesive tape of the present invention is suitable for processes that require processing under high load and high temperature environments, such as the manufacturing process of printed circuit boards, where high temperature (e.g., 180°C or higher) and high pressure (e.g., 20 kg / cm²) are required. 2 As described above, this is extremely useful for protecting, masking, temporarily fixing, and securing the workpiece (e.g., the surface of a laminated substrate) during processes involving prolonged heating and pressing (e.g., 2 hours or more).

Claims

1. A resin composition comprising a silicone raw rubber containing alkenyl groups, MQ resin, a crosslinking agent, a platinum catalyst, and an organic peroxide, The aforementioned resin composition, The gel fraction after crosslinking is between 50% and 60%. The storage modulus at 200°C after crosslinking is 100,000 Pa or more and 1,000,000 Pa or less. The gel fraction is determined by the formula: Gel fraction (%) = (Y / X) × 100%. This formula is used to determine the gel fraction. The raw resin composition before crosslinking is applied to a release liner so that the thickness after drying is 50 μm, dried in a drying oven at 60°C for 1 minute to remove the solvent, then heated at 200°C for 1 minute to cure the silicone component, cut to 50 mm × 50 mm, peel off the release liner to create a sheet-like sample of the resin composition, measure the initial mass (X), immerse the sample in toluene at a temperature of 23°C for 1 day to swell it, dry the sample in a 130°C dryer for 2 hours after immersion, remove the absorbed solvent, measure the dry mass (Y) of the resin composition obtained, and then measure the gel fraction (%). The resin composition is dried at 60°C for 1 minute to remove the solvent, and then heated and cured at 200°C for 1 minute to form a crosslinked adhesive layer. A 20 mm x 20 mm adhesive tape sample is attached to a polished copper plate, pressed down with a roller covered with a 2 kg rubber layer (one pass back and forth), left in a 23°C environment for 20 minutes to 1 hour, and then sandwiched between two SUS304 plates with mirror-finished surfaces at a temperature of 200°C and a pressure of 30 kg / cm². ２ After performing a heat press for 4 hours under the specified conditions, the adhesive tape sample was observed for adhesive leakage at 100x magnification using a microscope, and no adhesive leakage was observed from the four sides or corners of the adhesive tape sample. This resin composition (excluding silicone-based pressure-sensitive adhesive compositions in which the peroxide crosslinking agent remains unreacted until use) is one such composition.

2. The resin composition according to claim 1, wherein the product PA of the amount P (parts by mass) of organic peroxide and the theoretical amount A (%) of organic peroxide represented by the following formula (1) is 0.06 parts by mass or more, relative to 100 parts by mass of the total of the silicone raw rubber containing alkenyl groups, MQ resin, and crosslinking agent, is 0.06 parts by mass or more. A (%) = (B x 16 / M) x 100 (1) [In formula (1), A represents the theoretical amount of reactive oxygen species of the organic peroxide, B represents the number of peroxide bonds, and M represents the molecular weight of the organic peroxide.]

3. An adhesive tape having an adhesive layer composed of the resin composition according to claim 1 after crosslinking, The gel fraction of the adhesive layer is 50% or more and 60% or less. The storage modulus of the adhesive layer at 200°C is 100,000 Pa or more and 1,000,000 Pa or less, and An adhesive tape having an adhesive layer thickness of 2 μm or more and 10 μm or less.

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