Curable hot melt silicone composition, cured product thereof, and laminate containing the composition or cured product

Abstract

To provide a curable hot-melt silicone composition curing of which is difficult to be inhibited and which is superior in storage stability, and a sheet or a film made of the same.SOLUTION: A curable hot-melt silicone composition according to the present invention comprises: (A) a solid organopolysiloxane resin that has a specific ratio of (A1) an organopolysiloxane resin having a cure-reactive functional group including a carbon-carbon double bond, the organopolysiloxane resin including at least 20 mol% of the Q unit and (A2) an organopolysiloxane resin having no cure-reactive functional group including a carbon-carbon double bond, the organopolysiloxane resin including at least 20 mol% of the Q unit; (B) a chain organopolysiloxane having a cure-reactive functional group including at least two carbon-carbon double bonds; (C) an organohydrogenpolysiloxan resin the rate of mass loss of which is at most 10 mass%; and (D) a hydrosilylation reaction catalyst. The curable hot-melt silicone composition as a whole has hot-meltability.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a hot-melt curable silicone composition that is less susceptible to curing inhibition and has excellent storage stability, a curable silicone sheet or film with a thickness of 10 to 1000 μm that is preferably void-free and substantially flat, made from the composition, and a cured product thereof, as well as a laminate containing the composition or cured product. Furthermore, the present invention relates to applications of the composition or cured product (particularly semiconductor components such as semiconductor device components and optoelectronic device components, and semiconductor devices having the cured product, etc.), and to methods for manufacturing the composition, a sheet or film made therefrom, and a laminate using the same. [Background technology]

[0002] Curable silicone compositions are widely used in various industrial fields because they can cure into cured products with excellent heat resistance, cold resistance, electrical insulation, weather resistance, water repellency, and transparency. These cured silicone compositions are generally less prone to discoloration and exhibit less deterioration of physical properties over time compared to other organic materials, making them suitable as encapsulants for optical materials and semiconductor devices.

[0003] In Patent Documents 1 and 2, the applicant has proposed a hot-melt, curable granular silicone composition and a reactive silicone composition for molding. These silicone compositions consist of so-called phenyl silicone resins and have the advantages of superior hot-melt properties and superior hardness and strength of cured products compared to methyl silicone resins.

[0004] On the other hand, in recent years, miniaturization and increased power output have progressed in optoelectronic devices and the like. When hot-melt curable granular silicone compositions are applied to these devices, discoloration originating from the phenyl silicone resin may occur, especially at high temperatures of 200°C or above, which can reduce light reflectivity, particularly in the field of reflective materials. Therefore, there is a strong demand for silicone compositions that achieve desirable hot-melt properties and mechanical strength of the cured product after molding, while also satisfying the requirements for higher heat resistance and discoloration resistance.

[0005] In Patent Document 3, a transparent, hot-melt, curable silicone sheet using methyl silicone resin is disclosed. However, these compositions are susceptible to curing inhibition, and if compounds consisting of phosphorus or nitrogen are present in the substrate used, they hardly cure at all, or take an extremely long time to cure. Furthermore, due to the disclosed production method, it is difficult to produce these curable silicone sheets with a film thickness of 100 μm or more. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] International Publication No. 2016 / 136243 brochure [Patent Document 2] Japanese Patent Publication No. 2014-009322 [Patent Document 3] Special Publication No. 2017-512224 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] The object of the present invention is to provide a hot-melt curable silicone composition that is less susceptible to curing inhibition and has excellent storage stability, and a cured product thereof. Furthermore, the present invention is to provide a sheet or film made of such a curable silicone composition, in particular a sheet or film that is void-free, substantially flat, and has a film thickness of 10 to 1000 μm, and a release laminate containing a sheet or film made of the curable silicone composition. A further object of the present invention is to provide a semiconductor device component made of a cured product of the curable silicone composition, a semiconductor device having the cured product, and a method for molding the cured product. [Means for solving the problem]

[0008] As a result of diligent research, the inventors have found that (A)(A1) has a hardening-reactive functional group containing a carbon-carbon double bond within the molecule, and SiO 4 / 2 An organopolysiloxane resin that contains at least 20 mol% of the total siloxane units represented by (A2) and does not have hot-melt properties on its own, is solid at 25°C, and does not have a curing-reactive functional group containing a carbon-carbon double bond in the molecule, and SiO 4 / 2 The present invention was completed by finding that a curable silicone composition having hot-melt properties as a whole can be obtained by using predetermined amounts of (A1):(A2)=0:100 to 90:10, which contains at least 20 mol% or more of the siloxane units represented by the formula, and is a solid organopolysiloxane at 25°C that does not have hot-melt properties on its own, (B) a linear or branched organopolysiloxane having a carbon-carbon double bond-containing group and being liquid or plastic at 25°C, (C) an organohydrogenpolysiloxane having a specific chemical structure and having a mass loss rate of 10% by mass or less compared to before exposure after exposure at 100°C for 1 hour under atmospheric pressure, particularly at 1 atmosphere, and (D) a hydrosilylation reaction catalyst. In the present invention, the atmospheric pressure refers to the atmospheric pressure in the environment where the curable silicone composition of the present invention is handled in a laboratory, factory, etc., and is not limited to a specific pressure. Usually, it refers to the atmospheric pressure within the range from 1 atm (1013.25 hPa) to minus 100 hPa to plus 100 hPa, and particularly refers to 1 atm (1013.25 hPa). Also, in this specification, the room temperature refers to the temperature of the environment where the person handling the curable silicone composition of the present invention is. Generally, the room temperature refers to 0°C to 40°C, particularly 15°C to 30°C, and especially 18°C to 25°C.

[0009] More specifically, the curable silicone composition having hot melt properties of the present invention, that is, the curable hot melt silicone composition, (A) 100 parts by mass of an organopolysiloxane resin containing the following components (A1) and (A2) in a mass ratio of 0:100 to 90:10, preferably 0:100 to 75:25 (A1) An organopolysiloxane resin having a curing-reactive functional group containing a carbon-carbon double bond in the molecule and containing at least 20 mol% or more of the siloxane unit represented by SiO 4 / 2 in all siloxane units, which is a solid at 25°C and does not have hot melt properties by itself, (A2) An organopolysiloxane resin having no curing-reactive functional group containing a carbon-carbon double bond in the molecule and containing at least 20 mol% or more of the siloxane unit represented by SiO 4 / 2 in all siloxane units, which is a solid at 25°C and does not have hot melt properties by itself, (B) 10 to 100 parts by mass of a linear or branched organopolysiloxane having a curing-reactive functional group containing at least two carbon-carbon double bonds in the molecule and being liquid or plastic at 25°C, (C) The following average composition formula (1): (R 4 3SiO 1 / 2 ) a (R <* 5 2SiO 2 / 2 ) b (R 5 SiO 3 / 2 )c (SiO 4 / 2 ) d (1) (In the formula, R 4 Each of these is independently an unsubstituted or substituted monovalent hydrocarbon group that does not contain a hydrogen atom or an aliphatic unsaturated bond with 1 to 12 carbon atoms, and R 5 Each of these is independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms and not containing an aliphatic unsaturated bond, and all R 4 At least two of the atoms are hydrogen atoms, and a, b, c, and d are numbers that satisfy the conditions 0.01 ≤ a ≤ 0.6, 0 ≤ b, 0 ≤ c ≤ 0.9, 0 ≤ d ≤ 0.9, and a + b + c + d = 1 and c + d ≥ 0.2. Organohydrogenpolysiloxane (an amount in which the number of hydrogen atoms bonded to silicon atoms per alkenyl group bonded to silicon atoms in the entire curable silicone composition is 0.5 to 20.0) is expressed as such, and the mass loss rate from pre-exposure to pre-exposure after exposure at 100°C for 1 hour under atmospheric pressure is 10% by mass or less, and (D) Hydrosilylation reaction catalyst: A sufficient amount to cure this composition The composition contains [a certain substance] and is characterized by having hot-melt properties as a whole.

[0010] In addition to components (A) to (D) above, the above curable hot melt silicone composition may further contain, as component (E), a curing retarder for hydrosilylation reactions having a boiling point of 200°C or higher at atmospheric pressure, in an amount of 1 to 5000 ppm based on the total mass of the composition.

[0011] In the curable hot melt silicone composition of the present invention, component (C) is the following average composition formula (2): (HR 6 2SiO 1 / 2 ) e (R 6 2SiO 2 / 2 ) f (SiO 4 / 2 ) g (2) (In the formula, R 6Each of these is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms and containing no aliphatic unsaturated bonds, where e, f, and g are numbers satisfying the following conditions: 0.01 ≤ e ≤ 0.6, 0 ≤ f ≤ 0.9, 0.2 ≤ g ≤ 0.9, and e + f + g = 1. Preferably, it is an organohydrogenpolysiloxane represented by .

[0012] Furthermore, in the curable hot melt silicone composition of the present invention, component (C) is the following average composition formula (3): (HR 7 2SiO 1 / 2 ) h (R 7 2SiO 2 / 2 ) i (R 8 SiO 3 / 2 ) j (3) (In the formula, R 7 and R 8 Each of these is independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms and not containing an aliphatic unsaturated bond, and all R 8 At least 10 mol% of the compound is an aryl group, and h, i, and j are numbers that satisfy the following conditions: 0.01 ≤ h ≤ 0.6, 0 ≤ i ≤ 0.9, 0.2 ≤ j ≤ 0.9, and h + i + j = 1. Preferably, it is an organohydrogensiloxane represented by .

[0013] Furthermore, in the curable hot melt silicone composition of the present invention, the above component (A1) is (A1-1) the following average unit formula: (R 1 3SiO 1 / 2 ) a (R 1 2SiO 2 / 2 ) b (R 1 SiO 3 / 2 ) c (SiO 4 / 2 ) d (R 2 O 1 / 2)e (In the formula, each R 1R is a monovalent hydrocarbon group having 1 to 10 carbon atoms independently, however all R in one molecule 1 Of these, 1 to 12 mole% are alkenyl groups; each R 2 a is an alkyl group having a hydrogen atom or 1 to 10 carbon atoms; a, b, c, d, and e are numbers satisfying the following: 0.10 ≤ a ≤ 0.60, 0 ≤ b ≤ 0.70, 0 ≤ c ≤ 0.80, 0 ≤ d ≤ 0.65, 0 ≤ e ≤ 0.05, where c + d > 0.20 and a + b + c + d = 1. It is an organopolysiloxane resin that is solid at 25°C, which does not have hot-melt properties on its own, and Component (A2) is (A2-1) the following average unit formula: (R 3 3SiO 1 / 2 ) f (R 3 2SiO 2 / 2 ) g (R 3 SiO 3 / 2 ) h (SiO 4 / 2 ) i (R 2 O 1 / 2)j (In the formula, each R 3 R is a monovalent hydrocarbon group that independently has 1 to 10 carbon atoms and does not contain a carbon-carbon double bond; 2 (where f is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; f, g, h, i, and j are numbers satisfying the following: 0.35 ≤ f ≤ 0.55, 0 ≤ g ≤ 0.20, 0 ≤ h ≤ 0.20, 0.45 ≤ i ≤ 0.65, 0 ≤ j ≤ 0.05, and f + g + h + i = 1) This is an organopolysiloxane resin that, on its own, does not possess hot-melt properties, is solid at 25°C, and furthermore, The above component (B) has the following structural formula (B1): R 4 3SiO(SiR 4 20) k SiR 4 3 (In the formula, each R 4 R is a monovalent hydrocarbon group having 1 to 10 carbon atoms independently, however, R in one molecule 4(At least two of them are alkenyl groups, and k is a number between 20 and 5,000.) It is a linear diorganopolysiloxane represented by It is preferable.

[0014] The present invention also relates to a sheet or film made of the above-mentioned curable hot-melt silicone composition, characterized in that the sheet or film is formed by melting and kneading the components constituting the curable hot-melt silicone composition under vacuum or reduced pressure within a temperature range of 50 to 150°C, and then forming it into a sheet or film. Here, generally, "sheet" refers to something with a thickness of 250 μm or more, and "film" refers to something with a thickness of less than 250 μm. However, for the sake of simplicity, in this specification, films and sheets may be collectively referred to simply as "sheets."

[0015] The sheet or film described above preferably has a thickness between 10 and 1000 μm. Furthermore, it is preferable that the sheet or film has substantially small deviations in film thickness and is substantially flat.

[0016] The present invention also provides a sheet or film-like adhesive comprising the above-mentioned sheet or film.

[0017] Furthermore, the present invention provides a sheet or film-like sealant comprising a sheet or film of the above-mentioned curable hot-melt silicone composition. The sheet or film-like sealant of the present invention can also be used as an adhesive, for example, an adhesive for bonding two substrates together.

[0018] The present invention further provides a laminate comprising a sheet or film of the curable hot melt silicone composition and a sheet or film-like substrate attached to one or both sides of the curable hot melt silicone composition sheet or film, the sheet or film-like substrate having a release surface facing the curable silicone composition sheet or film, wherein the curable hot melt silicone composition sheet or film is configured to be peelable from the sheet or film-like substrate having the release surface.

[0019] The present invention further provides a laminate comprising a substrate which is an electronic component or its precursor, and a curable hot melt silicone composition layer formed by adhering at least one side of the curable hot melt silicone composition sheet or film to a part or all of the surface of the substrate, wherein the curable hot melt silicone composition is in an uncured state.

[0020] The present invention further provides a cured product obtained by curing the curable hot melt silicone composition of the present invention.

[0021] The present invention further provides a method for using the cured product as a component for a semiconductor device or an optoelectronic device, and a semiconductor device or optoelectronic device having the cured product as a component.

[0022] The present invention further provides a method for manufacturing the above-described laminate, characterized in that at least one surface of the uncured curable hot-melt silicone composition sheet or film is brought into close contact with a part or all of a substrate which is an electronic component or its precursor, by one or more means selected from a vacuum laminator, a vacuum press, and compression molding.

[0023] The present invention also provides a method for manufacturing a laminate containing a cured silicone composition layer, which includes a step of curing an uncured curable silicone composition by heating a laminate containing the above-mentioned curable hot-melt silicone composition.

[0024] A preferred method for manufacturing a laminate containing the cured silicone composition includes the steps of forming a laminate by bringing at least one surface of an uncured curable hot-melt silicone composition sheet or film into close contact with a part or all of a substrate which is an electronic component or its precursor, using one or more means selected from a vacuum laminator, a vacuum press, and compression molding, and further heating the laminate during or after the above step. [Effects of the Invention]

[0025] The curable silicone composition of the present invention has hot-melt properties, is resistant to curing inhibition, has excellent storage stability, and offers excellent handling and curing characteristics in overmolding and the like. Furthermore, the curable silicone composition exhibits high thixotropy at temperatures exceeding 100°C, preventing dripping even when heat-cured in an oven after heat-pressing onto a substrate. Moreover, the curable silicone composition of the present invention exhibits excellent flexibility and stress relaxation of the cured product, making it possible to obtain laminates that do not warp even when large-area substrates are sealed in one piece. In addition, the curable silicone composition of the present invention can be manufactured by a simple mixing process alone, and therefore can be manufactured efficiently. Furthermore, the present invention makes it possible to provide such a curable silicone composition in the form of a sheet or film with a thickness of 10 to 1000 μm, free from voids, or in the form of a release laminate containing the curable silicone composition sheet or film and a release sheet or film. Furthermore, a sheet or film made from the curable silicone composition of the present invention, or a release laminate containing the same, can be cut to the desired size as needed in the manufacturing process of electronic components, such as semiconductor devices, and can be applied to industrial production processes such as batch sealing and batch bonding of large-area substrates. [Brief explanation of the drawing]

[0026] [Figure 1]Figure 1 shows a graph illustrating the temperature-dependent changes in storage modulus and tanδ for a cured product obtained by curing the curable hot-melt silicone composition of the present invention (upper part of the graph) and a general silicone cured product (lower part of the graph). When the dynamic viscoelasticity of a general silicone cured product is measured at different temperatures, it exhibits a sharp glass transition at a certain temperature, although this varies depending on its network structure and the type of functional groups. In other words, the tanδ curve, which is the ratio of storage modulus to loss modulus, shows a sharp peak at a certain temperature. Generally, a high value of tanδ means that the applied force is dispersed (relaxed), so materials with a high tanδ can be said to have excellent stress relaxation properties. Here, the cured product obtained by curing the curable hot-melt silicone composition used in the multilayer laminate of the present invention does not show a sharp tanδ peak at a certain temperature, but rather exhibits a high tanδ value over a wide temperature range, which is preferable (Figure 1). [Figure 2] Figure 3 is a schematic diagram of the twin-screw extruder used in the example. [Modes for carrying out the invention]

[0027] The embodiments of the present invention will be described in detail below. The present invention is not limited to the embodiments described below, and can be implemented in various ways within the scope of its gist.

[0028] [Curing hot melt silicone composition] The curable hot melt silicone composition of the present invention has (A1) a curing-reactive functional group containing a carbon-carbon double bond within the molecule, and SiO 4 / 2 An organopolysiloxane resin that is solid at 25°C and does not have hot-melt properties on its own, containing at least 20 mol% or more of siloxane units represented by (A2) and having no curing-reactive functional groups containing carbon-carbon double bonds in the molecule, and SiO 4 / 2This silicone composition is thermosetting using a hydrosilylation reaction and mainly comprises an organopolysiloxane resin that is solid at 25°C and does not have hot-melt properties on its own, containing at least 20 mol% of the total siloxane units represented by (A1):(A2) = 0:100 to 90:10, preferably 0:100 to 75:25 by combining (component (A)) and a linear or branched organopolysiloxane containing carbon-carbon secondary bonds that is liquid or plastic at 25°C (component (B)), an organohydrogenpolysiloxane as a crosslinking agent (component (C)), and a hydrosilylation reaction catalyst (component (D)). The curable hot-melt silicone composition of the present invention is characterized in that, as a crosslinking agent, it uses an organohydrogenpolysiloxane having silicon-bonded hydrogen atoms, which has a specific chemical structure and a mass loss rate of 10% or less of the mass before exposure after exposure to 100°C for 1 hour under atmospheric pressure. Furthermore, the curable hot-melt silicone composition of the present invention may optionally use a hydrosilylation reaction retarder, also known as a curing retarder. In this case, it is preferable to use a curing retarder with a boiling point of 200°C or higher, particularly one with a boiling point of 200°C or higher at 1 atmosphere (1013.25 hPa). The composition of the present invention is further characterized in that, although components (A1) and (A2) use organopolysiloxane resins that do not possess hot-melt properties on their own, the composition as a whole, including components (B) to (D), possesses hot-melt properties. In this invention, unless otherwise specified, "having hot-melt properties" means that the composition has a softening point between 50 and 200°C, has a melt viscosity at 150°C (preferably less than 1000 Pa·s), and is flowable. Therefore, in this specification, the curable silicone composition having hot-melt properties of the present invention will also be referred to as a curable hot-melt silicone composition.

[0029] [The significance of combining components that are not easily volatile] The composition of the present invention is characterized by the use of a combination of components that do not easily volatilize under atmospheric pressure, particularly at 1 atmosphere (1013.25 hPa) at around 100°C, or components with a low content of volatile components. This is because, in the production process of the curable hot-melt silicone sheet or film of the present invention, described later, in order to obtain a sheet or film that does not contain voids, etc., it is necessary to melt and knead each component of the curable silicone composition, and the composition obtained therefrom, under reduced pressure in a temperature range of 50 to 150°C. By using each component of the present invention, it is possible to manufacture a sheet or film that does not contain voids, etc. Although each component is exposed to a predetermined temperature under reduced pressure for only a very short time, if a large amount of the active ingredient volatilizes under these kneading conditions, a problem arises in that a composition with the designed properties cannot be obtained. In particular, for crosslinking agents such as organohydrogenpolysiloxane and curing retarders, which are added in small amounts relative to the total mass of the curable silicone composition, the properties of the composition (curing properties, physical properties of the cured product, etc.) change significantly from the intended values ​​due to the volatilization of these components. Therefore, it is necessary to use components that are not easily volatile as part of the present invention, particularly component (C) and optional component (E).

[0030] [Hot-melt properties and composition of curable silicone compositions] The curable silicone composition according to the present invention is characterized by having hot-melt properties as a whole and being flowable under heating conditions. In particular, the curable silicone composition of the present invention preferably has a softening point of 50°C or higher and a melt viscosity at 150°C (preferably a melt viscosity of less than 1000 Pa·s). In this invention, it is sufficient that the composition as a whole has hot-melt properties, and the individual components constituting the composition do not need to have hot-melt properties.

[0031] More specifically, the curable silicone composition according to the present invention, i.e., the curable hot melt silicone composition, contains the following components (A), (B), (C), and (D) as essential components in the following proportions, and exhibits hot melt properties as a whole composition. (A) An organopolysiloxane resin containing the following components (A1) and (A2) in a mass ratio of 0:100 to 90:10, preferably 0:100 to 75:25, 100 parts by mass (A1) It has a curing-reactive functional group containing a carbon-carbon double bond in the molecule and contains at least 20 mol% or more of the siloxane units represented by SiO 4 / 2 among all the siloxane units, and it is a solid organopolysiloxane resin that does not have hot-melt properties by itself at 25°C. (A2) It does not have a curing-reactive functional group containing a carbon-carbon double bond in the molecule and contains at least 20 mol% or more of the siloxane units represented by SiO 4 / 2 among all the siloxane units, and it is a solid organopolysiloxane resin that does not have hot-melt properties by itself at 25°C. (B) A linear or branched organopolysiloxane having a curing-reactive functional group containing at least two carbon-carbon double bonds in the molecule, which is liquid or plastic at 25°C, 10 to 100 parts by mass; (C) The following average composition formula (1): (R 4 3SiO 1 / 2 ) a (R 5 2SiO 2 / 2 ) b (R 5 SiO 3 / 2 ) c (SiO 4 / 2 ) d (1) (In the formula, R 4 and R 5 are each independently an unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated bond with 1 to 12 carbon atoms, and at least 2 of all R 4 are hydrogen atoms, and a, b, c, and d are numbers that satisfy the conditions of 0.01 ≦ a ≦ 0.6, 0 ≦ b, 0 ≦ c ≦ 0.9, 0 ≦ d ≦ 0.9, and a + b + c + d = 1 and c + d ≧ 0.2.) An organohydrogenpolysiloxane represented by [the formula], having a mass reduction rate of 10% by mass or less with respect to that before exposure after being exposed to 100 °C for 1 hour under atmospheric pressure, particularly 1 atm (the amount such that the number of hydrogen atoms bonded to silicon atoms per one alkenyl group bonded to silicon atoms contained in the whole composition is 0.5 to 20.0); and (D) A hydrosilylation reaction catalyst, in an amount sufficient to cure the present composition. Furthermore, the above curable silicone composition may contain the following component (E) as an optional component: (E) A curing retarder for hydrosilylation reaction having a boiling point of 200 °C or higher under atmospheric pressure, particularly 1 atm. Furthermore, the curable hot-melt silicone composition of the present invention may be added with other additives known in the art within a range where the properties aimed at by the present invention can be maintained.

[0032] The shape of the curable hot-melt silicone composition of the present invention is not particularly limited, but for example, it may be in a form molded into a sheet or film shape, and particularly preferably in a sheet or film shape. Hereinafter, the components and optional components contained in the composition of the present invention will be described.

[0033] [Component (A)] The curable silicone composition according to the present invention contains, as component (A), an organopolysiloxane resin which has a curing-reactive functional group containing a carbon-carbon double bond and contains at least 20 mol% or more of siloxane units represented by SiO 4 / 2 in all siloxane units, does not exhibit hot-melt properties by itself, and is solid at 25 °C, and an organopolysiloxane resin which does not have a curing-reactive functional group containing a carbon-carbon double bond and contains at least 20 mol% or more of siloxane units represented by SiO 4 / 2 and does not exhibit hot-melt properties by itself and is solid at 25 °C, in a combination at a mass ratio of 0:100 to 90:10, preferably 0:100 to 75:25. The organopolysiloxane resin further contains R3SiO 1 / 2 2 / 2 3 / 2 ​​Siloxane units represented by (R represents a monovalent organic group, especially a monovalent hydrocarbon group with 1 to 10 carbon atoms), and R 2 O 1 / 2 (R 2 The compound may contain hydroxyl groups or alkoxy groups represented by hydrogen atoms or alkyl groups having 1 to 10 carbon atoms, but preferably at least 20 mol%, preferably 40 mol%, and especially in the range of 40 to 90 mol%, of the total siloxane units. 4 / 2 It contains siloxane units represented by SiO. 4 / 2 If the content of siloxane units represented by is less than 20 mol%, even if the organopolysiloxane resin contains other branched siloxane units (e.g., RSiO 3 / 2 Even if a large amount of ) is present, the technical effects of the present invention may not be achieved.

[0034] Such organopolysiloxane resins of component (A) (A1) Having a hardening-reactive functional group containing a carbon-carbon double bond within the molecule, and SiO 4 / 2 An organopolysiloxane resin that contains at least 20 mol% or more of the siloxane units represented by the formula, does not have hot-melt properties on its own, is solid at 25°C, and (A2) The molecule does not have a hardening-reactive functional group containing a carbon-carbon double bond, and SiO 4 / 2 An organopolysiloxane resin that contains at least 20 mol% or more of the siloxane units represented by , does not have hot-melt properties on its own, and is solid at 25°C. It is preferable that the mixture is an organopolysiloxane resin mixture containing in a mass ratio of 0:100 to 90:10, more preferably 0:100 to 75:25 (component (A1):component (A2)). Note that component (A1) is an optional component of component (A), and component (A2), described later, may be used alone as component (A). Furthermore, curing reactivity means that the component (C) can undergo a hydrosilylation reaction with the organohydrogensiloxane, thereby enabling the entire composition to be cured.

[0035] Although component (A) described above does not exhibit hot-melt properties on its own, by using it in combination with component (B), described later, within a predetermined ratio range, the composition as a whole of the present invention can be made to exhibit hot-melt properties.

[0036] [Organopolysiloxane resin having curing-reactive functional groups (A1)] The above component (A1) is one of the main components of this composition, and SiO 4 / 2 This organopolysiloxane resin contains at least 20 mol% of the total siloxane units represented by [formula], does not exhibit hot-melt properties on its own, and has a curing-reactive functional group containing a carbon-carbon double bond within its molecule.

[0037] Component (A1) must have a curing-reactive group having a carbon-carbon double bond within its molecule. Such a curing-reactive group is a hydrosilylation-reactive functional group and can form a cured product through a hydrosilylation crosslinking reaction with component (C). Such a curing-reactive group is preferably an alkenyl group, such as a 2-10 carbon alkenyl group including a vinyl group, allyl group, butenyl group, pentenyl group, hexenyl group, and heptenyl group, with vinyl or hexenyl groups being particularly preferred.

[0038] Component (A1) is an organopolysiloxane resin that does not possess hot-melt properties on its own and is solid in the solvent-free state. Here, "not possessing hot-melt properties" means that the organopolysiloxane resin, which is component (A1), does not exhibit heating and melting behavior below 200°C on its own, and specifically means that it does not have a softening point or melt viscosity below 200°C. For component (A1) to exhibit such properties, the functional groups in the organopolysiloxane resin must be monovalent hydrocarbon groups having 1 to 10 carbon atoms, particularly alkyl groups having 1 to 10 carbon atoms such as methyl groups, and must substantially not contain aryl groups such as phenyl groups. For example, it is preferable that the proportion of aryl groups in the total silicon-bonded organic groups be 5 mol% or less, more preferably 2 mol% or less, and it is particularly preferable that it contains no aryl groups at all. If component (A1) contains a large amount of aryl groups such as phenyl groups as organic groups, the component may become hot-melt on its own, and SiO 4 / 2 The effect of reinforcing the hardened material, which is specific to the substrate, may be reduced.

[0039] Preferably, the functional groups bonded to the silicon atoms of the organopolysiloxane resin of component (A1) are selected from methyl groups and alkenyl groups such as vinyl groups, and it is preferable that 70 to 99 mol% of the organic groups bonded to all silicon atoms are methyl groups, more preferably 80 to 99 mol%, and particularly preferably 88 to 99 mol% are methyl groups, with the remaining organic groups bonded to the silicon atoms being alkenyl groups such as vinyl groups. Within this range, component (A1) is not hot-melt on its own, but is useful as a component that is particularly excellent in terms of color resistance at high temperatures for cured products obtained from the curable silicone composition of the present invention. Note that the organopolysiloxane resin of component (A1) may contain small amounts of hydroxyl groups or alkoxy groups.

[0040] Component (A1) is an organopolysiloxane resin that is solid in the solvent-free state, and contains SiO2 within its molecule. 4 / 2It is characterized by containing at least 20 mol% or more of siloxane units represented by SiO2. Preferably, SiO2 4 / 2 The unit is at least 40 mol% of the total siloxane units, and is preferably 50 mol% or more, and particularly preferably in the range of 50 to 90 mol%. Furthermore, the organic group R possessed by the organopolysiloxane resin of component (A1) is a monovalent organic group, preferably a monovalent hydrocarbon group having 1 to 10 carbon atoms, and a functional group selected from alkyl groups and alkenyl groups having 1 to 10 carbon atoms, such as a methyl group. As mentioned above, from the standpoint of technical effect, it is preferable that group R substantially does not contain aryl groups such as a phenyl group.

[0041] Preferably, component (A1) is (A1-1) The average unit formula is as follows: (R 1 3SiO 1 / 2 ) a (R 1 2SiO 2 / 2 ) b (R 1 SiO 3 / 2 ) c (SiO 4 / 2 ) d (R 2 O 1 / 2)e (In the formula, each R 1 R is a monovalent hydrocarbon group having 1 to 10 carbon atoms independently, provided that the total R in one molecule 1 1 to 12 mole% of the group is an alkenyl group; each R 2 a is an alkyl group having a hydrogen atom or 1 to 10 carbon atoms; a, b, c, d, and e are numbers satisfying the following: 0.10 ≤ a ≤ 0.60, 0 ≤ b ≤ 0.70, 0 ≤ c ≤ 0.80, 0 ≤ d ≤ 0.65, 0 ≤ e ≤ 0.05, where c + d > 0.20 and a + b + c + d = 1. It is an organopolysiloxane resin that, on its own, does not have hot-melt properties and is solid at 25°C.

[0042] In the above average unit formula, each R 1The group is selected from the group consisting of monovalent hydrocarbon groups having 1 to 10 carbon atoms, such as alkyl groups like methyl, ethyl, propyl, butyl, pentyl, hexyl, and heptyl, particularly preferably methyl; alkenyl groups like vinyl, allyl, butenyl, pentenyl, and hexenyl, particularly preferably vinyl and / or 1-hexenyl; aryl groups like phenyl, tolyl, and xylyl, particularly preferably phenyl; and aralkyl groups like benzyl and phenethyl. Furthermore, the total R in one molecule 1 1 to 12 mol% of the total R in one molecule is an alkenyl group, preferably 1 to 12 mol% of the total R 1 2 to 10 mol% of the component is alkenyl groups, particularly preferably vinyl groups. If the alkenyl group content is below the lower limit of the above range, the mechanical strength (hardness, etc.) of the resulting cured product may be insufficient. On the other hand, if the alkenyl group content is below the upper limit of the above range, the composition containing this component can achieve good hot-melt performance as a whole. Note that each R 1 It is preferable that R is a functional group selected from alkyl groups having 1 to 10 carbon atoms, such as methyl groups, and alkenyl groups, such as vinyl groups and hexenyl groups, and from the viewpoint of the technical effects of the present invention, 1 Preferably, it contains substantially no aryl groups such as phenyl groups. If it contains a large amount of aryl groups such as phenyl groups, component (A) itself will have hot-melt properties, which may prevent the technical effects of the present invention from being achieved, and in the cured product, SiO 4 / 2 The effect of reinforcing the hardened material, which is specific to the substrate, may be reduced.

[0043] In the above formula, R 2 R is an alkyl group having a hydrogen atom or 1 to 10 carbon atoms. 2 Examples of alkyl groups include methyl, ethyl, propyl, butyl, pentyl, and hexyl. 2 Base R including 2 O 1 / 2 This corresponds to a hydroxyl group or alkoxy group possessed by the organopolysiloxane resin of component (A).

[0044] In the above formula, a is the general formula: R 13SiO 1 / 2 This number represents the proportion of siloxane units. 'a' satisfies 0.1 ≤ a ≤ 0.60, preferably 0.15 ≤ a ≤ 0.55. If 'a' is greater than or equal to the lower limit of the above range, the composition containing this component can achieve good hot-melt performance as a whole. On the other hand, if 'a' is less than or equal to the upper limit of the above range, the mechanical strength (hardness, elongation, etc.) of the cured product obtained by curing the curable silicone composition of the present invention will not become too low.

[0045] In the above formula, b is the general formula: R 1 2SiO 2 / 2 This number represents the proportion of siloxane units. b satisfies 0 ≤ b ≤ 0.70, preferably 0 ≤ b ≤ 0.60. If b is below the upper limit of the above range, the composition containing this component can achieve good hot-melt performance as a whole and can be obtained as a composition with low stickiness at room temperature.

[0046] In the above formula, c is the general formula: R 3 SiO 3 / 2 This is a number indicating the proportion of siloxane units. c satisfies 0 ≤ c ≤ 0.80, preferably 0 ≤ c ≤ 0.75. If c is below the upper limit of the above range, the composition containing this component can achieve good hot-melt performance as a whole, and a low-tack or tack-free composition with little stickiness at room temperature can be obtained. In the present invention, c may be 0, and it is preferable that c is 0.

[0047] In the above formula, d is the formula SiO 4 / 2 This number represents the proportion of siloxane units, and it is necessary that 0.00 ≤ d ≤ 0.65, preferably 0.20 ≤ d ≤ 0.65, and particularly preferably 0.25 ≤ d ≤ 0.65. If d is within the above numerical range, the composition containing this component can achieve good hot-melt performance as a whole, and the cured product obtained by curing the composition can have sufficient flexibility.

[0048] In the present invention, c or d in the above formula may be 0, but it is necessary that c+d > 0.20. If the value of c+d is 0.20 or less, good hot-melt performance cannot be achieved for the composition as a whole, and the technical effects of the present invention may not be fully achieved.

[0049] In the above formula, e is the general formula: R 2 O 1 / 2 This number represents the proportion of units, and these units refer to hydroxyl groups or alkoxy groups bonded to silicon atoms that may be contained in the organopolysiloxane resin. e satisfies 0 ≤ e ≤ 0.05, and preferably 0 ≤ e ≤ 0.03. If e is below the upper limit of the range, a material can be obtained that achieves good hot-melt performance as a whole composition. In the above formula, the sum of a, b, c, and d, which are the sums of each siloxane unit, is equal to 1.

[0050] Component (A1) is an organopolysiloxane resin having the above characteristics, but since it is a solid at room temperature, it is preferable to use it dissolved in a solvent or solvent mixture selected from the group consisting of aromatic hydrocarbons such as toluene, xylene, and mesitylene; ethers such as tetrahydrofuran and dipropyl ether; silicones such as hexamethyldisiloxane, octamethyltrisiloxane, and decamethyltetrasiloxane; esters such as ethyl acetate, butyl acetate, and propylene glycol monomethyl ether acetate; and ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone. The solvent used here can be efficiently removed in the process described later.

[0051] [Component (A2)] Component (A2) is one of the main components of this composition. It does not possess hot-melt properties on its own, does not contain any curing-reactive functional groups, and is a solid organopolysiloxane resin at 25°C. By using it in combination with components (A1) and (B) within a predetermined quantitative range, it is a component that enables the overall hot-melt properties of the curable silicone composition and the excellent stress-relaxing properties of the cured product obtained by curing the curable silicone composition.

[0052] Component (A2) is an organopolysiloxane resin that does not exhibit hot-melt properties on its own and is solid in the solvent-free state. Here, "not exhibiting hot-melt properties" means that the organopolysiloxane resin, which is component (A2), does not exhibit heating and melting behavior below 200°C on its own, and specifically means that it does not have a softening point or melt viscosity below 200°C. For component (A2) to exhibit such properties, the functional groups in the organopolysiloxane resin must be monovalent hydrocarbon groups having 1 to 10 carbon atoms, particularly alkyl groups having 1 to 10 carbon atoms such as methyl groups, and must substantially not contain aryl groups such as phenyl groups. For example, it is preferable that the proportion of aryl groups in the total silicon-bonded organic groups be 5 mol% or less, more preferably 2 mol% or less, and it is particularly preferable that it contains no aryl groups at all. If component (A2) contains a large amount of aryl groups such as phenyl groups as organic groups, the component may become hot-melt, and SiO 4 / 2 The effect of reinforcing the hardened material, which is specific to the substrate, may be reduced.

[0053] Component (A2), like component (A1), is solid at 25°C, and SiO 4 / 2The organopolysiloxane resin contains at least 20 mol% or more of the siloxane units represented by the formula, but is characterized by not having a curing-reactive functional group containing at least one carbon-carbon double bond in the molecule. That is, component (A2) is characterized by not containing alkenyl groups such as vinyl groups as functional groups in the organopolysiloxane resin. Examples of groups that the organopolysiloxane resin of component (A2) has include monovalent hydrocarbon groups having 1 to 10 carbon atoms, particularly alkyl groups having 1 to 10 carbon atoms such as methyl groups, and this organopolysiloxane resin is preferably substantially free of aryl groups such as phenyl groups, for example, the proportion of aryl groups in the total silicon-bonded organic groups is preferably 5 mol% or less, more preferably 2 mol% or less, and it is particularly preferable that it contains no aryl groups at all.

[0054] Preferably, the functional groups bonded to the silicon atoms in component (A2) are alkyl groups having 1 to 10 carbon atoms, such as methyl groups, and it is preferable that 70 to 100 mol% of the organic groups bonded to all silicon atoms are methyl groups, more preferably 80 to 100 mol%, and particularly preferably 88 to 100 mol% are methyl groups. Within this range, component (A2) does not exhibit hot-melt properties on its own, and SiO 4 / 2 This component can be particularly excellent in reinforcing cured products containing siloxane units represented by [the formula shown]. The organopolysiloxane resin of component (A2) may also contain small amounts of hydroxyl groups or alkoxy groups.

[0055] Component (A2) does not have a curing-reactive functional group with a carbon-carbon double bond in its molecule, and therefore does not form a cured product when combined with the organohydrogenpolysiloxane of component (C). However, it improves the hot-melt properties of the curable silicone composition as a whole and provides a reinforcing effect on the cured product obtained by curing the curable silicone composition. Furthermore, if necessary, it can be used in combination with component (A1) which has a curing-reactive functional group to adjust the heat melting properties of the resulting curable silicone composition and the physical properties of the composition after curing.

[0056] Component (A2) is an organopolysiloxane resin that is solid at 25°C in the absence of a solvent, and contains branched siloxane units SiO2 within its molecule. 4 / 2 The material is characterized by containing at least 20 mol% or more of siloxane units represented by SiO2. Preferably, the organopolysiloxane of component (A2) is SiO2. 4 / 2 The unit is at least 40 mol% of the total siloxane units, and is preferably 50 mol% or more, and particularly preferably in the range of 50 to 65 mol%.

[0057] Preferably, component (A2) is (A2-1) the following average unit formula: (R 3 3SiO 1 / 2 ) f (R 3 2SiO 2 / 2 ) g (R 3 SiO 3 / 2 ) h (SiO 4 / 2 ) i (R 2 O 1 / 2)j (In the formula, each R 3 R is a monovalent hydrocarbon group that independently has 1 to 10 carbon atoms and does not contain a carbon-carbon double bond; 2 (where f is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; f, g, h, i, and j are numbers satisfying the following: 0.35 ≤ f ≤ 0.55, 0 ≤ g ≤ 0.20, 0 ≤ h ≤ 0.20, 0.45 ≤ i ≤ 0.65, 0 ≤ j ≤ 0.05, and f + g + h + i = 1) This is an organopolysiloxane resin that, on its own, does not possess hot-melt properties.

[0058] In the above average unit formula, each R 3R is a group selected from the group consisting of monovalent hydrocarbon groups that independently have 1 to 10 carbon atoms and do not contain carbon-carbon double bonds, such as alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, and heptyl, particularly preferably methyl; aryl groups such as phenyl, tolyl, and xylyl, particularly preferably phenyl; and aralkyl groups such as benzyl and phenethyl. Here, the total R in one molecule 3 It is preferable that 70 mol% or more of the alkyl group having 1 to 10 carbon atoms, such as a methyl group, and particularly preferable that 88 mol% or more of the alkyl group having 1 to 10 carbon atoms, particularly a methyl group, is from the standpoint of industrial production and the technical effects of the invention. On the other hand, R 3 Preferably, the component (A2) is substantially free of aryl groups such as phenyl groups. If it contains a large amount of aryl groups such as phenyl groups, component (A2) itself may have hot-melt properties, which may prevent the achievement of the technical effects of the present invention, and the color resistance of the cured product obtained by curing the curable silicone composition of the present invention may deteriorate at high temperatures.

[0059] In the above formula, R 2 As mentioned above, R 2 If the alkyl group is an alkyl group, examples of alkyl groups include methyl, ethyl, propyl, butyl, pentyl, and hexyl.

[0060] In the above formula, f is the general formula: R 3 3SiO 1 / 2 This number represents the proportion of siloxane units. f satisfies 0.35 ≤ f ≤ 0.55, preferably 0.40 ≤ f ≤ 0.50. If f is above the lower limit of the above range, the curable silicone composition containing this component can achieve good hot-melt performance as a whole. On the other hand, if f is below the upper limit of the above range, the mechanical strength (hardness, etc.) of the resulting cured product will not be too low.

[0061] In the above formula, g is the general formula: R 1 2SiO 2 / 2This number represents the proportion of siloxane units. g satisfies the condition 0 ≤ g ≤ 0.20, preferably 0 ≤ g ≤ 0.10. If g is below the upper limit of the range, the curable silicone composition containing this component can achieve good hot-melt performance as a whole and can be obtained as a composition with low stickiness at room temperature. In the present invention, g may be 0, and it is preferable that g is 0.

[0062] In the above formula, h is the general formula: R 1 SiO 3 / 2 This number represents the proportion of siloxane units. h satisfies 0 ≤ h ≤ 0.20, preferably 0 ≤ h ≤ 0.10. If h is below the upper limit of the range, the curable silicone composition containing this component can achieve good hot-melt performance as a whole and can be obtained as a composition with low stickiness at room temperature. In the present invention, h may be 0, and it is preferable that h is 0.

[0063] In the above formula, i is SiO 4 / 2 i is a number that indicates the proportion of siloxane units, and it is necessary that i be 0.45 ≤ i ≤ 0.65, and it is particularly preferable that i be 0.50 ≤ i ≤ 0.65. When i is within this numerical range, the curable silicone composition containing this component can achieve good hot melt performance as a whole, the cured product obtained by curing the curable silicone composition has excellent mechanical strength, and the composition as a whole is non-sticky and easy to handle.

[0064] In the above formula, j is the general formula: R 2 O 1 / 2 This number represents the proportion of units, where each unit means a hydroxyl group or alkoxy group bonded to a silicon atom that may be contained in the organopolysiloxane resin. j satisfies 0 ≤ j ≤ 0.05, preferably 0 ≤ j ≤ 0.03. If j is below the upper limit of the above range, good hot-melt performance can be achieved for the curable silicone composition as a whole. In the above formula, the sum of the individual siloxane units, f, g, h, and i, is equal to 1.

[0065] Component (A2) is an organopolysiloxane resin having the characteristics described above, and its handling is the same as that of component (A1). That is, since component (A2) is solid at room temperature (e.g., 25°C), it can be used in the same way as component (A1) by dissolving it in the solvent or solvent mixture described above in order to mix it with component (B), and then the solvent can be removed to prepare a curable silicone composition.

[0066] [Removal of volatile low molecular weight components in component (A)] Regarding component (A1) and component (A2), volatile low molecular weight components are generated during each production process. Specifically, these volatile low molecular weight components are M4Q structures, and M units (R 3 3SiO 1 / 2 ) and Q unit (SiO 4 / 2 It appears as a by-product when polymerizing organopolysiloxane resins consisting of (A1) and (A2). This structure has the effect of significantly reducing the hardness of the cured product obtained from the curable silicone composition of the present invention. The organopolysiloxane resins of components (A1) and (A2) are produced by the polymerization reaction of raw material monomers in the presence of an organic solvent that is highly compatible with them, and a solid organopolysiloxane resin can be obtained by removing the organic solvent by vacuum drying or the like. However, the M4Q structure has high compatibility with the organopolysiloxane resin and is difficult to remove by drying conditions that remove the organic solvent. It was known that the M4Q structure could be removed by exposing the organopolysiloxane resin containing it to a temperature of 200°C or higher for a short time, but if the M4Q structure is removed by exposing the curable silicone composition containing the M4Q structure to a high temperature after integral molding with a substrate such as a semiconductor, a decrease in the volume of the cured product generated from the curable silicone composition and a significant increase in hardness may occur, which may change the dimensions of the molded product and cause warping, etc. Therefore, in order to apply the curable silicone composition of the present invention to applications in which it is laminated with a substrate such as a semiconductor, it is preferable to remove the M4Q structure from the organopolysiloxane resin at the raw material stage, preferably before the molding process in which the curable silicone composition is laminated with the substrate and cured, and more preferably before the curable silicone composition is prepared.

[0067] Methods for removing the M4Q structure from the organopolysiloxane resin include, in the organopolysiloxane resin manufacturing process, obtaining particulate organopolysiloxane resin and then drying it in an oven or the like to remove the M4Q structure, or removing it together with the aforementioned organic solvent using a twin-screw compounder, as described later.

[0068] More specifically, components (A1) and (A2) are manufactured in the presence of an organic solvent, and volatile components such as the M4Q structure appear as by-products during the manufacturing process. Since the volatile components can be removed by treating the obtained crude raw material, organopolysiloxane resin, at a high temperature of about 200°C for a short time, it is possible to simultaneously remove the organic solvent and volatile components such as the M4Q structure from components (A1) and (A2) using a twin-screw kneader set to a temperature of 200°C or higher. From the viewpoint of efficiently producing the curable hot-melt silicone composition of the present invention, it is preferable to add component (B), described later, to component (A2) dissolved in an organic solvent or a mixture of components (A1) and (A2), mix them in a liquid state, and feed the mixture to a twin-screw extruder set to 200°C or higher, thereby removing volatile components such as the M4Q structure along with the organic solvent. By this method, a mixture of hot-melt components (A) and (B) can be obtained, which can be used in the process described later for kneading with the remaining components constituting the curable silicone composition.

[0069] [Mass ratio of component (A1) to component (A2) in component (A)] In order for the composition as a whole to have hot-melt properties, component (A2), or a mixture of component (A1) and component (A2), must be mixed with component (B), described later, in a predetermined ratio. The ratio of component (A1) to component (A2) may be in the range of 0:100 to 90:10, preferably in the range of 0:100 to 85:25, more preferably 0:100 to 80:20, and particularly preferably 0:100 to 75:25. Component (A2) itself does not have curing-reactive functional groups and therefore does not have curability. However, in this composition, by using component (A2) in combination with component (A1), it is possible to adjust to some extent the storage modulus, loss modulus, and tanδ calculated from their ratios in the cured product obtained by curing this curable composition. This makes it possible to achieve suitable modulus, flexibility, and stress relaxation properties in the cured product. Furthermore, even without component (A1), a curable hot-melt silicone composition with the desired properties in this invention can be prepared by combining component (A2) with component (B).

[0070] [Component (B)] Component (B) is one of the main components of this curable silicone composition, and is a liquid or plastic linear or branched organopolysiloxane at 25°C, having a curing-reactive functional group containing at least two carbon-carbon double bonds in its molecule. When such a curing-reactive linear organopolysiloxane is mixed with the solid organopolysiloxane resin of component (A) described above, the entire composition can exhibit hot-melt properties.

[0071] Component (B) must have a curing-reactive functional group having a carbon-carbon double bond within its molecule. Such a curing-reactive functional group has hydrosilylation reactivity and forms a cured product through crosslinking reactions with other components. Such a curing-reactive functional group is an alkenyl group similar to that of component (A1), preferably an alkenyl group having 2 to 10 carbon atoms. Examples of alkenyl groups include vinyl, allyl, butenyl, pentenyl, and hexenyl, with vinyl or hexenyl groups being particularly preferred.

[0072] Component (B) is a liquid or plastic linear or branched organopolysiloxane at 25°C (room temperature), and when mixed with component (A), which is solid at room temperature, the entire composition can exhibit hot-melt properties. The chemical structure of the organopolysiloxane of component (B) may be linear or consist of a small number of branched siloxane units (e.g., general formula: R 4 SiO 3 / 2 T units (R 4 (A monovalent hydrocarbon group having 1 to 10 carbon atoms independently) or SiO 4 / 2 It may be a branched organopolysiloxane having Q units represented by , but preferably, (B1) The following structural formula: R 4 3SiO(SiR 4 20) k SiR 4 3 (In the formula, each R 4 R is a monovalent hydrocarbon group having 1 to 10 carbon atoms independently, however, R in one molecule 4 (At least two of them are alkenyl groups, and k is a number between 20 and 5,000.) This is a linear diorganopolysiloxane represented by [formula]. Preferably, it is a linear diorganopolysiloxane having one alkenyl group, particularly a vinyl group, at each end of the molecular chain.

[0073] In the above formula, each R 4 R is a group selected from the group consisting of monovalent hydrocarbon groups having 1 to 10 carbon atoms, such as alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, and heptyl, particularly preferably methyl; alkenyl groups such as vinyl, allyl, butenyl, pentenyl, and hexenyl, particularly preferably vinyl and / or hexenyl; aryl groups such as phenyl, tolyl, and xylyl, particularly preferably phenyl; and aralkyl groups such as benzyl and phenethyl. Furthermore, R in one molecule 4 At least two of them are alkenyl groups, preferably vinyl groups. Also, each R 4It is preferable that the functional group is selected from the group consisting of alkyl groups having 1 to 10 carbon atoms, such as methyl groups, and alkenyl groups, such as vinyl groups and hexenyl groups, and all R 4 Of these, at least two per molecule are alkenyl groups, and the remaining R 4 It is preferable that R is a methyl group. Furthermore, from the viewpoint of the technical effects of the invention, 4 It is preferable that it substantially does not contain aryl groups such as phenyl groups. If it contains a large amount of aryl groups such as phenyl groups, the color resistance of the cured product obtained from the curable silicone composition at high temperatures may deteriorate. Particularly preferable is having one alkenyl group such as a vinyl group at each end of the molecular chain, and other R 4 It is preferable that the group is a methyl group.

[0074] In the above formula, k is a number between 20 and 5,000, preferably between 30 and 3,000, and particularly preferably between 45 and 800. If k is above the lower limit of the above range, a curable silicone composition with low stickiness at room temperature can be obtained. On the other hand, if k is below the upper limit of the above range, good hot-melt performance can be achieved for the curable silicone composition as a whole.

[0075] Here, in order for the composition as a whole to exhibit hot-melt properties, the amount of component (B), which is a linear or branched organopolysiloxane, is in the range of 10 to 100 parts by mass, preferably in the range of 10 to 70 parts by mass, and more preferably in the range of 15 to 50 parts by mass, per 100 parts by mass of component (A), which is an organopolysiloxane resin. If the content of component (B) is within the above range, the resulting curable silicone composition will exhibit good hot-melt properties, the mechanical strength of the cured product obtained by curing the curable silicone composition will be increased, and the stickiness of the resulting curable silicone composition at room temperature will be reduced, thereby improving the handling workability of the composition.

[0076] [Component (C)] Component (C) is an organohydrogenpolysiloxane having a carbon-carbon double bond contained in components (A) and (B) above, and a silicon atom bonded hydrogen atom that can be crosslinked in the presence of a catalyst for hydrosilylation reaction, specifically having the following average composition formula (1), (R 4 3SiO 1 / 2 ) a (R 5 2SiO 2 / 2 ) b (R 5 SiO 3 / 2 ) c (SiO 4 / 2 ) d (R 2 O 1 / 2)e (1) (In the formula, R 4 Each of these is independently an unsubstituted or substituted monovalent hydrocarbon group that does not contain a hydrogen atom or an aliphatic unsaturated bond with 1 to 12 carbon atoms, and R 5 Each of these is independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms and not containing an aliphatic unsaturated bond, and all R 4 At least two of the atoms are hydrogen atoms, and a, b, c, and d are numbers that satisfy the conditions 0.01 ≤ a ≤ 0.6, 0 ≤ b, 0 ≤ c ≤ 0.9, 0 ≤ d ≤ 0.9, and a + b + c + d = 1 and c + d ≥ 0.2. This organohydrogenpolysiloxane is represented by [formula]. Furthermore, this organohydrogenpolysiloxane is characterized by a mass loss rate of 10% by mass or less compared to the pre-exposure state after exposure to 100°C for 1 hour under atmospheric pressure.

[0077] In the above formula, each R 4 Each of these is the same or different monovalent hydrocarbon group having 1 to 12 carbon atoms and lacking an aliphatic unsaturated carbon bond, or a hydrogen atom, provided that there are at least 2, preferably at least 3 R atoms in one molecule. 4 R is a hydrogen atom. 4The monovalent hydrocarbon group is, for example, a group selected from the group consisting of alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, and heptyl, especially the methyl group; aryl groups such as phenyl, tolyl, and xylyl, especially the phenyl group; and aralkyl groups such as benzyl and phenethyl. From an industrial standpoint, R 4 The monovalent hydrocarbon group represented is preferably independently a methyl group or a phenyl group.

[0078] In the formula, R 5 This is a monovalent hydrocarbon group having 1 to 12 carbon atoms that does not have an aliphatic unsaturated carbon bond, and the above R 4 Examples of groups similar to the monovalent hydrocarbon group are given. 5 It is preferable that the group is selected from a methyl group and a phenyl group.

[0079] In the formula, a, b, c, and d are numbers that satisfy the following conditions: 0.01 ≤ a ≤ 0.6, 0 ≤ b, 0 ≤ c ≤ 0.9, 0 ≤ d ≤ 0.9, and a + b + c + d = 1 and c + d ≥ 0.2. A specific example is M H MT resin, M H T resin, M H MTQ resin, M H MQ resin, M H DQ resin, and M H Examples include Q resin. In the notation for the resin, M, D, T, and Q represent M units, D units, T units, and Q units, respectively, and MH represents M units containing hydrogen atoms.

[0080] In the above equation (1), R 2 R is an alkyl group having a hydrogen atom or 1 to 10 carbon atoms. 2 Examples of alkyl groups include methyl, ethyl, propyl, butyl, pentyl, and hexyl. 2 Base R including 2 O 1 / 2 This corresponds to a hydroxyl group or alkoxy group possessed by the organohydrogenpolysiloxane of component (C).

[0081] In the above formula, e is the general formula: R 2 O1 / 2 This number represents the proportion of units, and these units mean hydroxyl groups or alkoxy groups bonded to silicon atoms that may be contained in the organopolysiloxane resin. e satisfies 0 ≤ j ≤ 0.05, preferably 0 ≤ j ≤ 0.03. As stated above, in formula (1) above, the sum of a, b, c, and d, which are the sums of each siloxane unit, is equal to 1.

[0082] The silicon-bonded hydrogen atom (SiH) of component (C) must be present in the M unit, because SiH groups in the M unit have high hydrosilylation reactivity. If SiH groups are present in units other than the M unit, such as D and T units, their hydrosilylation reactivity decreases drastically, and problems may arise such as the hydrosilylation reaction not proceeding or becoming extremely slow if a curing inhibitor is present. Furthermore, by making the organohydrogenpolysiloxane a branched structure containing T or Q units instead of a linear structure, the number of SiH groups in a single molecule increases, and the overall hydrosilylation reactivity of the molecule increases even further. By using such highly reactive organohydrogenpolysiloxanes, it is possible to construct a curing system that is resistant to curing inhibitors.

[0083] On the other hand, it is known that crosslinking agents containing a relatively large number of M units having SiH groups generate a relatively large amount of low molecular weight active ingredients during their production process. When such crosslinking agents are added and the melt-kneading process under degassing described later is performed, the active ingredients may volatilize, potentially resulting in a problem where the curable silicone composition does not meet the designed properties. To avoid this, the present invention requires the use of an organohydrogenpolysiloxane in which the mass loss rate from before exposure after exposure at 100°C for 1 hour under atmospheric pressure is 10% by mass or less. The specific molecular structure of the organohydrogenpolysiloxane of component (C) is M H Q Resin M H By changing the ratio of units to Q units, M H Reduce the number of units, M H One example is the introduction of D units into Q resin. Also, M HA relatively large functional group such as a phenyl group may be introduced as the T-unit functional group of the T resin. H T Ph (T Ph (where represents a phenyl group-substituted T unit) is compatible with other components in the composition of the present invention and does not separate from the composition, as long as its molecular weight does not become too high.

[0084] Component (C) is preferably an organohydrogenpolysiloxane represented by the following average composition formula (2). (HR 6 2SiO 1 / 2 ) e (R 6 2SiO 2 / 2 ) f (SiO 4 / 2 ) g (2) In formula (2), R 6 Each of these is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms and containing no aliphatic unsaturated bonds, where e, f, and g are numbers satisfying the conditions 0.01 ≤ e ≤ 0.6, 0 ≤ f ≤ 0.9, 0.2 ≤ g ≤ 0.9, and e + f + g = 1. A specific example of this monovalent hydrocarbon group is R in the above average composition formula (1). 4 This is the same as the specific example of a monovalent hydrocarbon group represented by R. 6 Preferably, each of these groups is independently selected from a methyl group and a phenyl group.

[0085] Furthermore, component (C) is preferably an organohydrogenpolysiloxane represented by the following average formula (3). (HR 7 2SiO 1 / 2 ) h (R 7 2SiO 2 / 2 ) i (R 8 SiO 3 / 2 ) j (3) In formula (3), R 7 and R 8Each of these is independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms and not containing an aliphatic unsaturated bond, and all R 8 At least 10 mol% of the group is an aryl group, and h, i, and j are numbers that satisfy the following conditions: 0.01 ≤ h ≤ 0.6, 0 ≤ i ≤ 0.9, 0.2 ≤ j ≤ 0.9, and h + i + j = 1. A specific example of this monovalent hydrocarbon group is R in the above average composition formula (1). 4 This is the same as the specific example of a monovalent hydrocarbon group represented by R. 8 This applies to all R 8 Preferably, each group is independently selected from methyl groups and phenyl groups, provided that at least 10 mol% of them are phenyl groups.

[0086] The organohydrogenpolysiloxane represented by the average composition formula (2) and the organohydrogenpolysiloxane represented by the average composition formula (3) may be used individually or in combination.

[0087] The amount of organohydrogenpolysiloxane in component (C) of the curable silicone composition of the present invention is sufficient to cure the curable silicone composition, and it is preferable that the amount of silicon-bonded hydrogen atoms in the organohydrogenpolysiloxane of component (C) is such that, relative to the curing reactive functional groups containing carbon-carbon double bonds in components (A) and (B) (for example, alkenyl groups such as vinyl groups), the number of silicon-bonded hydrogen atoms per alkenyl group is 0.5 to 20.0, particularly in the range of 1.0 to 10, relative to the alkenyl groups bonded to silicon atoms in the entire curable silicone composition.

[0088] [Component (D)] Component (D) is a hydrosilylation catalyst for curing the curable silicone composition of the present invention by crosslinking the hydrosilylation-reactive carbon-carbon double bonds contained in components (A) and (B) with the silicon-bonded hydrogen atoms, i.e., Si-H groups, contained in component (C) through a hydrosilylation reaction. As the hydrosilylation catalyst for component (D), compounds or metals with hydrosilylation catalytic activity known in the art can be used, but examples include platinum-based catalysts, rhodium-based catalysts, and palladium-based catalysts, and platinum-based catalysts are preferred because they can significantly accelerate the curing of the composition. Examples of platinum-based catalysts include platinum fine powder, chloroplatinic acid, an alcoholic solution of chloroplatinic acid, platinum-alkenylsiloxane complexes, platinum-olefin complexes, platinum-carbonyl complexes, and catalysts in which these platinum-based catalysts are dispersed or encapsulated in thermoplastic resins such as silicone resins, polycarbonate resins, and acrylic resins, and platinum-alkenylsiloxane complexes are particularly preferred. Examples of these alkenylsiloxanes include 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, alkenylsiloxanes in which some of the methyl groups of these alkenylsiloxanes are replaced with ethyl groups, phenyl groups, etc., and alkenylsiloxanes in which the vinyl groups of these alkenylsiloxanes are replaced with allyl groups, hexenyl groups, etc. In particular, because the stability of this platinum-alkenylsiloxane complex is good, it is preferable to use 1,3-divinyl-1,1,3,3-tetramethyldisiloxane as a catalyst for the hydrosilylation reaction, and it is preferable to add the complex in the form of an alkenylsiloxane solution to other components constituting the curable silicone composition. In addition, from the viewpoint of improving the handling ease of the platinum catalyst and the pot life of the curable silicone composition, a particulate platinum-containing hydrosilylation catalyst dispersed or encapsulated in a thermoplastic resin may be used. Furthermore, non-platinum metal catalysts such as iron, ruthenium, and iron / cobalt may be used as catalysts to promote the hydrosilylation reaction.

[0089] The amount of the hydrosilylation catalyst, which is component (D), added is not particularly limited, as long as it is an amount that can cure the curable silicone composition of the present invention within the target time under the curing conditions. Generally, when the hydrosilylation catalyst is a metal compound such as platinum, it is preferable that the amount is such that the metal atoms are in the range of 0.01 to 100 ppm, 0.01 to 50 ppm, or 0.01 to 10 ppm by mass relative to the entire composition.

[0090] [Component (E)] The curable silicone composition of the present invention may further contain a curing retarder (E) in addition to the above components (A) to (D).

[0091] The structure of the curing retarder is not particularly limited, but it is preferable that its boiling point is 200°C or higher under atmospheric pressure. This is because, in the production process of the curable silicone composition sheet described later, if a compound with a low boiling point is used as a curing retarder when the raw materials are melted and kneaded under reduced pressure, some or all of the curing retarder may volatilize during the melting and kneading process, and the target curing retardation effect for the curable silicone composition may not be obtained.

[0092] The curing retarder of the present invention is not particularly limited, but examples include alkyne alcohols such as 2-methyl-3-butyne-2-ol, 3,5-dimethyl-1-hexyne-3-ol, 2-phenyl-3-butyne-2-ol, and 1-ethynyl-1-cyclohexanol; enyne compounds such as 3-methyl-3-penten-1-yine and 3,5-dimethyl-3-hexen-1-yine; alkenyl group-containing low molecular weight siloxanes such as tetramethyltetravinylcyclotetrasiloxane and tetramethyltetrahexenylcyclotetrasiloxane; and alkynyloxysilanes such as methyl-tris(1,1-dimethylpropynyloxy)silane and vinyl-tris(1,1-dimethylpropynyloxy)silane. Of these, it is particularly preferable to use a compound with a boiling point of 200°C or higher at atmospheric pressure. The content of the curing retarder in the curable silicone composition is not particularly limited, but it is preferably in the range of 1 to 10,000 ppm by mass relative to the composition.

[0093] [Other additives] In addition to the components described above, the curable hot-melt silicone composition of the present invention may also contain materials known in the art as additives that can be used in silicone compositions. Examples of additives that can be used include, but are not limited to, the following.

[0094] Fillers can be used as additives to improve the mechanical properties or flame retardancy of cured products obtained from the curable hot-melt silicone composition of the present invention. Examples of fillers include inorganic fillers, organic fillers, and mixtures thereof. From a functional standpoint, one or more fillers selected from reinforcing fillers, thermally conductive fillers, pigments (especially white pigments), phosphors, etc., may be added to the curable hot-melt silicone composition of the present invention. When using fillers, it is preferable to select and use the type and amount of filler within a range that allows the curable hot-melt silicone composition of the present invention to be melt-kneaded and within a range that has an acceptable effect on the properties of the curable hot-melt silicone composition of the present invention (e.g., curing properties, mechanical properties after curing, weather resistance, etc.). In one preferred embodiment of the curable hot-melt silicone composition of the present invention, the curable hot-melt silicone composition does not contain fillers.

[0095] Furthermore, the composition of the present invention may contain other optional components, such as adhesion promoters, as long as they do not impair the objectives of the present invention.

[0096] As adhesion-imparting agents, organosilicon compounds having at least one alkoxy group bonded to a silicon atom in one molecule are preferred. Examples of such alkoxy groups include methoxy, ethoxy, propoxy, butoxy, and methoxyethoxy groups, with methoxy being particularly preferred. Examples of groups bonded to silicon atoms other than alkoxy groups in organosilicon compounds include halogen-substituted or unsubstituted monovalent hydrocarbon groups such as alkyl groups, alkenyl groups, aryl groups, aralkyl groups, and halogenated alkyl groups; glycidoxyalkyl groups such as 3-glycidoxypropyl and 4-glycidoxybutyl groups; epoxycyclohexylalkyl groups such as 2-(3,4-epoxycyclohexyl)ethyl and 3-(3,4-epoxycyclohexyl)propyl groups; epoxyalkyl groups such as 3,4-epoxybutyl and 7,8-epoxyoctyl groups; acrylic group-containing monovalent organic groups such as 3-methacryloxypropyl groups; and hydrogen atoms. The organosilicon compound preferably has an alkenyl group or a group that can react with a silicon-bonded hydrogen atom in the composition, and more specifically, it is preferable that it has a silicon-bonded hydrogen atom or an alkenyl group. Furthermore, since it can impart good adhesion to various substrates, it is preferable that the organosilicon compound has at least one epoxy-group-containing monovalent organic group in one molecule. Examples of such organosilicon compounds include organosilane compounds, organosiloxane oligomers, and alkyl silicates. Examples of molecular structures of these organosiloxane oligomers or alkyl silicates include linear, partially branched linear, branched, cyclic, and reticular structures, and linear, branched, and reticular structures are particularly preferred.Examples of organosilicon compounds include silane compounds such as 3-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 3-methacryloxypropyltrimethoxysilane; siloxane compounds having at least one silicon-bonded alkenyl group or silicon-bonded hydrogen atom and at least one silicon-bonded alkoxy group in one molecule; silane compounds or siloxane compounds having at least one silicon-bonded alkoxy group and siloxane compounds having at least one silicon-bonded hydroxyl group and at least one silicon-bonded alkenyl group in one molecule; reaction mixtures of amino group-containing organoalkoxysilanes and epoxy group-containing organoalkoxysilanes; and organic compounds having at least two alkoxysilyl groups in one molecule, with bonds other than silicon-oxygen bonds between those silyl groups, general formula: R. a n Si(OR b ) 4-n (In the formula, R a is a monovalent epoxy group-containing organic group, R b (where n is an alkyl group or hydrogen atom with 1 to 6 carbon atoms, and n is a number in the range of 1 to 3.) Examples include epoxy group-containing silanes or their partially hydrolyzed condensates, reaction mixtures of vinyl group-containing siloxane oligomers (including those with a linear or cyclic structure) and epoxy group-containing trialkoxysilanes, methyl polysilicate, ethyl polysilicate, and epoxy group-containing ethyl polysilicate. This adhesion-imparting agent is preferably a low-viscosity liquid, and although its viscosity is not limited, it is preferably in the range of 1 to 500 mPa·s at 25°C. The content of this adhesion-imparting agent is also not limited, but it is preferably in the range of 0.01 to 10 parts by mass per 100 parts by mass of the total composition.

[0097] In the present invention, a particularly suitable adhesion-imparting agent is a reaction mixture of an amino group-containing organoalkoxysilane and an epoxy group-containing organoalkoxysilane. Such components improve the initial adhesion of the curable silicone composition to various substrates in contact during the curing process, and especially low-temperature adhesion to unwashed substrates. Such reaction mixtures are disclosed in Japanese Patent Publication No. 52-8854 and Japanese Patent Application Publication No. 10-195085.

[0098] Examples of alkoxysilanes having an amino group-containing organic group that constitute such components include aminomethyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)aminomethyltributoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, and 3-anilinopropyltriethoxysilane.

[0099] Examples of epoxy group-containing organoalkoxysilanes include 3-glycidoxyprolyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 2-(3,4-epoxycyclohexyl)ethylmethyldimethoxysilane.

[0100] The ratio of alkoxysilanes having amino group-containing organic groups to alkoxysilanes having epoxy group-containing organic groups is preferably in the range of (1:1.5) to (1:5) in molar ratio, and particularly preferably in the range of (1:2) to (1:4). This component can be easily synthesized by mixing the alkoxysilanes having amino group-containing organic groups and the alkoxysilanes having epoxy group-containing organic groups as described above and reacting them at room temperature or under heating.

[0101] In particular, in the curable hot melt silicone composition of the present invention, when reacting an alkoxysilane having an amino group-containing organic group with an alkoxysilane having an epoxy group-containing organic group by the method described in Japanese Patent Application Publication No. 10-195085, a general formula is obtained by cyclization by an alcohol exchange reaction: [ka] {where, R 1 R is an alkyl group, an alkenyl group, or an alkoxy group. 2 The same or different general formulas: [ka] (In the formula, R 4 R is an alkylene group or an alkylene oxyalkylene group, 5 It is a monovalent hydrocarbon group, R 6 R is an alkyl group, 7 R is an alkylene group, 8 (where a is an alkyl group, an alkenyl group, or an acyl group, and a is 0, 1, or 2.) A group selected from the group consisting of groups represented by R 3 These are the same or different hydrogen atoms or alkyl groups. It is particularly preferable to contain a carbasilatran derivative represented by . Examples of such carbasilatran derivatives include carbasilatran derivatives having a silicon atom-bonded alkoxy group or a silicon atom-bonded alkenyl group in one molecule, represented by the following structure. [ka] (In the formula, Rc is a group selected from a methoxy group, an ethoxy group, a vinyl group, an allyl group, and a hexenyl group.)

[0102] Furthermore, in the present invention, a silatoran derivative represented by the following structural formula may be used as an adhesion promoter. [ka] R in the formula 1 R is the same or different hydrogen atom or alkyl group, in particular, 1 A hydrogen atom or a methyl group is preferred as the element. Also, R in the above formula 2 is a hydrogen atom, an alkyl group, and the general formula: -R 4 -Si(OR 5 ) x R 6 (3-x) The same or different group selected from the group consisting of alkoxysilyl group-containing organic groups represented by , however, R 2 At least one of these is an organic group containing this alkoxysilyl group. 2 Examples of alkyl groups include methyl groups. 2 In an organic group containing an alkoxysilyl group, the R in the formula 4 R is a divalent organic group, and examples include alkylene groups or alkylene oxyalkylene groups, with ethylene groups, propylene groups, butylene groups, methylene oxypropylene groups, and methylene oxypentylene groups being particularly preferred. Also, R in the formula 5 R in the formula is an alkyl group having 1 to 10 carbon atoms, preferably a methyl group or an ethyl group. 6 x is a substituted or unsubstituted monovalent hydrocarbon group, preferably a methyl group. Also, x in the formula is 1, 2, or 3, preferably 3.

[0103] Such R 2 Examples of organic groups containing an alkoxysilyl group include the following groups: -(CH2)2Si(OCH3)2(CH2)2Si(OCH3)2CH3 -(CH2)3Si(OC2H5)2(CH2)3Si(OC2H5)(CH3)2 -CH2O(CH2)3Si(OCH3)3 -CH2O(CH2)3Si(OC2H5)3 -CH2O(CH2)3Si(OCH3)2CH3 -CH2O(CH2)3Si(OC2H5)2CH3 -CH2OCH2Si(OCH3)2CH2OCH2Si(OCH3)(CH3)2

[0104] R in the above equation 3 R is at least one group selected from the group consisting of substituted or unsubstituted monovalent hydrocarbon groups, alkoxy groups having 1 to 10 carbon atoms, glycidoxyalkyl groups, oxyranylalkyl groups, and acyloxyalkyl groups, 3 Examples of monovalent hydrocarbon groups include alkyl groups such as methyl groups, 3 Examples of alkoxy groups include methoxy, ethoxy, and propoxy groups, and R 3 Examples of glycidoxyalkyl groups include the 3-glycidoxypropyl group, and R 3 Examples of oxyranyl alkyl groups include the 4-oxyranylbutyl group and the 8-oxyranyloctyl group, R 3 Examples of acyloxyalkyl groups include acetoxypropyl group and 3-methacryloxypropyl group. In particular, R 3 The group is preferably an alkyl group, an alkenyl group, or an alkoxy group, and more preferably an alkyl group or an alkenyl group, with groups selected from methyl, vinyl, allyl, and hexenyl groups being particularly preferred examples.

[0105] Furthermore, the composition may also contain, as long as it does not impair the purpose of the present invention, other optional components such as heat-resistant agents including iron oxide (red iron oxide), cerium oxide, cerium dimethyl silanolate, cerium fatty acid salts, cerium hydroxide, and zirconium compounds; as well as dyes, pigments other than white, flame retardants, etc.

[0106] The curable hot-melt silicone composition of the present invention may be used in the form of granules, pellets, sheets, or films. Pelletized compositions are obtained by tableting, offering excellent handling and curability. Note that "pellets" are sometimes also called "tablets." While the shape of the pellets is not limited, they are typically spherical, ellipsoidal, or cylindrical. The size of the pellets is also not limited, but for example, they have an average particle diameter or equivalent circle diameter of 500 μm or more. When producing such pelletized compositions, tableting of the granular composition is an efficient production method. If the composition of the present invention is to be produced in granular form, it is possible to manufacture a granular composition by adding components (A) to (C) of the curable silicone composition of the present invention, along with other additives if applicable, and optionally adding component (D), and stirring them using a powder mixer described later. When a pelletized composition is manufactured without containing component (D), if it is used as the curable silicone composition of the present invention, necessary additives containing component (D) can be added at the time of use, and the mixture can be kneaded and melted to produce a curable hot-melt silicone composition that can be used for the intended purpose.

[0107] This composition may be used in the form of a sheet or film. For example, a sheet or film made of the curable silicone composition of the present invention having an average thickness of 10 to 1000 μm has hot-melt properties and heat-curable properties at high temperatures, so it has excellent handling workability and melting characteristics and is particularly advantageous for use in compression molding and the like. In this case, it is preferable to form a sheet or film of a composition containing all of components (A) to (D), including component (D).

[0108] Such sheet or film compositions can be formed into a sheet or film of a predetermined thickness by first creating a homogeneous mixture of all components using a single-screw or twin-screw continuous kneader, and then passing the mixture through a double-roll molding machine or the like. Alternatively, the aforementioned granular curable hot-melt silicone composition may be obtained first, and if necessary, component (D) may be added, then the mixture may be kneaded in a kneader to make it homogeneous, and then passed through a molding machine such as a double-roll molding machine to produce a sheet or film of the desired thickness.

[0109] The above-mentioned sheet or film-like composition may be manufactured using organopolysiloxane resin fine particles as a raw material (Method A), or it may be manufactured using a hot-melt solid component obtained by dispersing a solid organopolysiloxane resin at room temperature and optionally a chain-like diorganopolysiloxane in an organic solvent and removing the organic solvent (Hot Bulk Method) (Method B). Specifically, the former (Method A) involves the following steps: Step 1: A step of mixing organopolysiloxane resin fine particles, a curing agent, and optionally a functional filler; Step 2: The mixture obtained in Step 1 is kneaded while being heated and melted at a temperature of 120°C or lower; Step 3: A step of forming a laminate by laminating the heated, melted, and kneaded mixture obtained in Step 2 between two films, each having at least one release surface; Step 4: A step of stretching the mixture in the laminate obtained in Step 3 between rolls to form a curable hot melt silicone sheet having a specific film thickness. This is a manufacturing method that includes [something].

[0110] On the other hand, the latter (Method B) involves the following steps: Step 1: A step in which an organic solvent is used to disperse or dissolve an organopolysiloxane resin that is solid at room temperature, and optionally a chain-like diorganopolysiloxane, in a solution, and then the organic solvent is removed at a temperature of 150°C or higher to obtain a hot-melt solid. Step 2: After adding all the hardening agents to the hot-melt solid obtained in Step 1, the mixture is kneaded while being heated and melted at a temperature of 120°C or lower; Step 3: A step of forming a laminate by laminating the heated and melted mixture obtained in Step 2 between two films, each having at least one release surface; Step 4: A process to stretch the mixture in the laminate obtained in Step 3 between rolls to form a curable hot melt silicone sheet having a specific film thickness. This is a manufacturing method that includes [something].

[0111] Furthermore, in either manufacturing method (Method A or Method B), steps 3 and 4 may be continuous and integrated processes. For example, the mixture obtained in step 2 after heating and melting may be laminated by being discharged or coated between films having at least one release surface directly below the rolls, and simultaneously stretched to a specific film thickness by adjusting the gap between the rolls. Thus, a manufacturing method having steps 3 and 4 substantially integrated is also included within the scope of the above-described manufacturing method. In other words, steps 3 and 4 may be performed sequentially and integrally, comprising the steps of: dispensing or coating the mixture obtained in step 2 between two release films to sandwich the mixture between the two release films, for example, between two long release films; and passing the resulting laminate, consisting of the two release films and the mixture interposed between them, through rolls to stretch-molde the mixture between the release films and adjust it to a predetermined film thickness to obtain the desired laminate. Such a method of performing steps 3 and 4 integrally is also included in the manufacturing method described above.

[0112] Furthermore, in step 3 of method A or method B described above, the step of laminating the heated and melted mixture between the films is not particularly limited, and may be (i) a step in which the heated and melted mixture from step 2 is discharged or applied onto a first release film having a release surface, and then the second release film is brought into contact with the surface of the mixture opposite to the surface of the mixture that is in contact with the first release film, thereby interposing the heated and melted mixture between the first and second release films, i.e., sandwiching it; or (ii) a step in which the heated and melted mixture from step 2 is discharged or applied between the first release film and the second release film having release surfaces, thereby interposing the heated and melted mixture between the two release films. An example of (ii) is a method in which the first and second release films are brought close together by appropriate means, such as two rolls, and the mixture from step 2 is discharged or applied to the area where the two release films are close together, thereby sandwiching the mixture in the gap between the two release films simultaneously or almost simultaneously. It is particularly preferable that steps 3 and 4 described above are continuous steps.

[0113] Furthermore, regarding these manufacturing methods, the applicants have proposed a method for manufacturing curable silicone sheets and the entire process including the manufacturing apparatus used therein in Japanese Patent Application No. 2019-167832, Japanese Patent Application No. 2019-167833, and priority applications claiming these, and in the present invention, the said method and manufacturing apparatus can also be applied when forming curable hot-melt silicone compositions into sheets or films.

[0114] [Use of a curable hot-melt silicone composition as a laminate and film adhesive] This curable hot-melt silicone composition can be used in sheet or film form, and in particular, it can be used as a laminate having a structure in which a sheet-like material made of the above curable hot-melt silicone composition is interposed between two film-like substrates having a release layer. This film-like substrate with a release layer (generally called a release film) can be peeled off from the sheet-like material made of the curable hot-melt silicone composition when it is used as an adhesive or sealant. Hereinafter, this laminate will also be referred to as a release laminate.

[0115] The method for manufacturing the peelable laminate described above is not particularly limited, but as an example, the following steps: Step 1: A step of mixing the components of the above-mentioned curable hot melt silicone composition. Step 2: The mixture obtained in Step 1 is kneaded while being heated and melted. Step 3: A step of forming a laminate by laminating the mixture obtained in Step 2 after heating and melting between two release films having at least one release surface, such that the mixture is in contact with the release surface. Step 4: The laminate obtained in Step 3 is pressed between rolls, and the mixture interposed between two release films is rolled to form a curable hot melt silicone composition sheet or film having a specific film thickness. Methods including the above can be cited. Furthermore, optionally, a roll with a cooling or temperature control function may be used in step 4. In addition, a step of cutting the laminate containing the obtained curable hot melt silicone composition sheet or film may be added after step 4. There are no particular restrictions on the thickness of this release film; therefore, it includes not only what is generally called a film but also what is called a sheet. However, in this specification, it is referred to as a release film regardless of its thickness.

[0116] The temperature of the mixing step in step 1 described above is not particularly limited, but it may be heated as needed to ensure that each component is thoroughly mixed, and the heating temperature can be, for example, 50°C or higher.

[0117] By peeling off the release film from the release laminate of the present invention, a sheet or film made of a curable hot melt silicone composition is obtained. Therefore, the present invention also provides such a sheet or film. The sheet or film of the present invention preferably has a thickness of 10 to 1000 μm, and preferably is flat. Flat means that the thickness of the obtained sheet or film is within a range of ±100 μm or less, preferably within a range of ±50 μm or less, and more preferably within a range of ±30 μm or less.

[0118] The type of material used for the substrate of the release film constituting the release laminate is not particularly limited, but for example, polyester film, polyolefin film, polycarbonate film, or acrylic film can be used as appropriate. The sheet-like substrate is preferably non-porous. The release film is a film having a release layer formed by treating one or both sides of a film made of such a material to impart release properties, and such treatments are well known in the art.

[0119] A release layer is a layer with release properties applied to the surface of a release film. The release layer is a structure that allows a sheet or film made of a curable silicone composition to be easily peeled off a film-like substrate, and is sometimes called a release liner, separator, mold release layer, or release coating layer. Preferably, the release layer can be formed as a release coating layer having release coating properties, such as a silicone-based release agent, a fluorine-based release agent, an alkyd-based release agent, or a fluorosilicone-based release agent. Alternatively, the film-like substrate surface may be physically made to form fine irregularities to reduce adhesion to the curable silicone composition, or the substrate may be made of a material that does not easily adhere to the layer made of the curable hot melt silicone composition of the present invention or its cured product. In particular, in the laminate of the present invention, it is preferable to use a release layer made by curing a fluorosilicone-based release agent as the release layer.

[0120] The above-described laminate can be used, for example, by peeling off one of the two release films constituting the laminate, applying an uncured sheet or film-like member made of a curable silicone composition that is not in contact with the release film to a substrate, and then peeling off the uncured sheet or film-like member from the other film-like substrate, i.e., the release film.

[0121] This curable silicone composition can be handled in granular, pellet, or sheet form at room temperature and is a non-flowing solid at 25°C. Here, non-flowing means that it does not deform and / or flow in the absence of external force. Preferably, when the curable silicone composition is molded into pellets or tablets, it does not deform and / or flow at 25°C and in the absence of external force. Such non-flowing can be evaluated, for example, by placing the molded composition on a hot plate at 25°C and observing that the composition does not substantially deform and / or flow even when no external force is applied or when a certain load is applied to the composition. Being non-flowing at 25°C means that the composition has good shape retention at that temperature and low surface tackiness, so the composition can be easily handled even in its uncured state.

[0122] Furthermore, it is preferable that the softening point of this composition is 100°C or lower. Such a softening point is defined as the temperature at which, when a 22 mm high piece of the composition is pressed down on a hot plate with a 100 gram load for 10 seconds, and the deformation of the composition is measured after the load is removed, the deformation in the height direction is 1 mm or more.

[0123] This composition tends to decrease in viscosity rapidly with increasing temperature under high temperature and pressure conditions (i.e., in the manufacturing process of the laminate described above). Therefore, it is preferable to use a value measured under high temperature and pressure conditions similar to those when actually using the composition as a useful melt viscosity value for handling the composition. Accordingly, it is preferable to measure the melt viscosity of this composition under high pressure using a high-pressure flow tester (manufactured by Shimadzu Corporation) rather than measuring it with a rotational viscometer such as a rheometer. Specifically, it is preferable that the melt viscosity of this composition at 150°C measured using a high-pressure flow tester is 200 Pa·s or less, more preferably 150 or less. This is because the adhesion of this composition to the substrate is good after it has been hot-melted (i.e., heated and melted) and then cooled to 25°C.

[0124] [Method for producing a curable hot melt silicone composition] This composition can be produced by powder mixing components (A) to (D), and optionally other optional components, such as component (E), at a temperature below 50°C, further heating and melting to uniformly mix each component, and then cooling as necessary. However, the method is not limited to this method, and the composition may be produced by any method. The powder mixer that can be used in this production method is not particularly limited, but examples include a single-screw or twin-screw continuous mixer, a double-roll mixer, a Ross mixer, a Hobart mixer, a dental mixer, a planetary mixer, a kneader mixer, a Lab Millser, a small pulverizer, and a Henschel mixer, with Lab Millser and Henschel mixers being preferred.

[0125] [Method for manufacturing a curable hot melt silicone composition sheet or film] The curable hot-melt silicone composition of the present invention may take any shape, but one preferred embodiment is that it is in the form of a sheet or film made of the uncured composition. As described above, the curable silicone composition sheet or film according to the present invention (hereinafter, the sheet and the film are collectively referred to as the curable silicone composition sheet for simplicity, and in that case, the "sheet" includes the film) has hot-melt properties and is characterized by containing the above-described components (A), (B), (C), and (D) as essential components. In one aspect, the method for producing a sheet made of the curable hot-melt silicone composition of the present invention includes the following steps 1 to 4. Step 1: A step of mixing the constituent components of the curable hot-melt silicone composition, preferably at a temperature of 50°C or higher. Step 2: A step of kneading the mixture obtained in Step 1 while heating and melting it. Step 3: A step of laminating the mixture after heating and melting obtained in Step 2 between two release films having at least one release surface so that the mixture contacts the release surface to form a laminate, and Step 4: A step of pressing the laminate obtained in Step 3 between rolls to form a curable hot-melt silicone sheet having a specific film thickness.

[0126] The curable silicone composition of the present invention and the shaped products of the composition, such as pellets, sheets, and films, have hot-melt properties. Here, "having hot-melt properties" means that the softening point of the material is within the range of 50°C to 200°C, and it can be softened by heating to change its shape, or it can become flowable by heating. Further, the curable silicone sheet according to the present invention does not have hot-melt properties by itself for the organopolysiloxane resin component (A) which is its constituent component, but exhibits hot-melt properties when combined with components (B) and (C).

[0127] Hereinafter, each step of the method for producing the above-described curable hot-melt composition sheet will be described in more detail. [Step 1] Step 1 described above is a step of mixing the components of a curable hot melt silicone composition, which are organopolysiloxane resin (component A, preferably in the form of fine particles), organopolysiloxane that is liquid or plastic at 25°C (component B), organohydrogenpolysiloxane as a curing agent (component C), and hydrosilylation catalyst (component D), and optionally further additives (e.g., component E), to produce a curable silicone composition, preferably in the form of granules or powder. Each of these components has already been described.

[0128] The mixture obtained by step 1, preferably in granular form, is a granular curable hot-melt silicone composition, and the composition as a whole has hot-melt properties. On the other hand, the mixture is non-flowing at 25°C. Here, non-flowing means that it does not substantially deform and / or flow in the absence of external force, and preferably, when the granular composition obtained in step 1 is further molded into pellets or tablets, it does not substantially deform and / or flow at 25°C and in the absence of external force. Such non-flowing can be evaluated, for example, by placing the molded composition on a hot plate at 25°C and observing that the composition does not substantially deform and / or flow even when no external force is applied to the composition or when a certain load is applied. Being non-flowing at 25°C means that the composition has good shape retention at that temperature and low surface tackiness, so the composition can be easily handled even in an uncured state.

[0129] The softening point of the mixture obtained by step 1 is 200°C or lower, preferably 150°C or lower. Such a softening point is the temperature at which, when a composition 22 mm high is pressed down on a hot plate with a load of 100 grams for 10 seconds and the load is removed, the deformation of the composition in the height direction is 1 mm or more.

[0130] The mixture obtained in step 1 can be softened or melted by heating it to a temperature above its softening point in step 2, which will be described later, thereby giving the mixture a certain degree of fluidity. By molding the softened or melted material, a hot-melt curable silicone composition sheet can be produced from, for example, a granular curable silicone composition obtained in step 1.

[0131] The step of mixing components (A) to (D) of the present invention and other optional components, such as component (E), is not particularly limited, but can be carried out by powder mixing at a temperature below the softening point of the entire resulting mixture, preferably below the softening point of component (A). The powder mixer used in this manufacturing method is not particularly limited, and examples include single-screw or twin-screw continuous mixers, double-roll mixers, Ross mixers, Hobart mixers, Dental mixers, Planetary mixers, Kneader mixers, Lab Millsers, Miniature pulverizers, and Henschel mixers, with Lab Millsers, Miniature pulverizers, and Henschel mixers being preferred.

[0132] [Process 2] Step 2 is a process of kneading the heat-meltable mixture obtained in Step 1 while heating and melting it. By heating and kneading the heat-meltable mixture at a temperature above its softening point, preferably in the temperature range of 50°C to 200°C, the entire composition is melted or softened and mixed, allowing the components contained in the mixture to be uniformly mixed. When the mixture obtained in Step 2 is pressure-molded into a sheet in Step 4 via Step 3, using a pressure device, for example, with two rolls, a thin layer sheet of uniform thickness can be formed in a single pressurization, which has the practical benefit of avoiding molding defects and the occurrence of cracks in the sheet itself. On the other hand, if the temperature at which the mixture is heated is below the lower limit, the softening of the mixture will be insufficient, and it may be difficult to obtain a molten or softened mixture in which each component is uniformly mixed throughout, even with mechanical force. When such a mixture in which the components are not uniformly mixed is pressure-molded into a sheet in Step 4 via Step 3, it may not be possible to form a thin layer molded sheet of uniform thickness, and damage and / or cracks may occur in the sheet. Conversely, if the temperature at which the mixture is heated exceeds the aforementioned upper limit, the hydrosilylation reaction may occur during mixing, causing the entire mixture to thicken significantly or harden, losing its hot-melt properties, or forming a hardened product, which is undesirable. For this reason, the hydrosilylation reaction catalyst of component (D) can be added in step 2 after the mixture of other components has been thoroughly mixed, rather than being mixed with the other components from the beginning in step 1. If component (D) is added, it is preferable to lower the temperature as much as possible within the range where mixing is possible. Alternatively, component (D) can be a hydrosilylation reaction catalyst dispersed in a thermoplastic resin or encapsulated in a thermoplastic resin as fine particles, and such a method is preferred.

[0133] If the heat melt viscosity of the mixture obtained in step 1 is low and it is highly fluid, then in step 3 described later, the mixture can be pre-formed, for example, into a shape close to a sheet, and then laminated onto the release film. Preferably, if the melt viscosity of the mixture obtained by heating, melting, and kneading in step 2, as measured by a high-efficiency flow tester at 150°C, is in the range of 1 to 1,000 Pas, then the mixture can be pre-formed before being laminated onto the release film in step 3.

[0134] On the other hand, if the mixture obtained in step 1 has a high heating and melting viscosity, and the molten mixture has poor fluidity, in step 2, the mixture obtained in step 1 may be melt-kneaded at a temperature above its softening point to form a uniform composition, and then laminated directly onto the release film in step 3 without pre-molding.

[0135] The kneading equipment used in step 2 is not limited and can be any batch-type kneading equipment such as a kneader, Banbury mixer, Henschel mixer, planetary mixer, 2-roll mill, 3-roll mill, Ross mixer, or Laboplast mill equipped with heating and cooling functions, or a continuous-type heating and kneading equipment such as a single-screw extruder or twin-screw extruder equipped with heating and cooling functions. It is not particularly limited and can be selected according to the work efficiency in terms of processing time and the ability to control shear heat generation. From the perspective of shortening the processing time, a continuous-type heating and kneading equipment such as a single-screw extruder or twin-screw extruder may be used, or a batch-type mixer such as a Laboplast mill may be used, but a continuous-type heating and kneading equipment such as a single-screw extruder or twin-screw extruder is preferred because it offers better work efficiency.

[0136] [Process 3] Step 3 is a step in which the mixture obtained in Step 2 after heating and melting is interposed between two films having at least one release surface and laminated, and is a preliminary step for further pressure molding of this laminate in Step 4. By forming a laminate in which the mixture obtained in Step 2 is sandwiched between release films, a sheet-like molded product made of a curable silicone composition can be obtained by pressure molding with a roll from above the release films. Furthermore, after the laminate is molded, the release film can be removed from the laminate containing the curable silicone composition sheet by utilizing the properties of the release surface of the release sheet.

[0137] The mixture obtained in step 2 after heating and melting is interposed between two release films to form a laminate. Depending on the usage of the resulting curable hot melt silicone composition sheet (including the film), it is preferable that both release films have release surfaces, and it is particularly preferable in step 3 to place the mixture obtained in step 2 between the two release films so that it is in contact with the release surface of each release film to form a laminate. With the laminate having such a configuration, by pressurizing the curable hot melt silicone composition interposed, i.e., sandwiched between the release films in step 4, and further cutting the laminate if desired, a laminate (also called a laminated sheet) can be obtained in which a thin layer of curable hot melt silicone composition sheet is interposed between release films, and the release films can be peeled off from both sides of the curable hot melt silicone composition sheet. Therefore, when using a curable silicone composition sheet, it is possible to use it by peeling off one of the release films placed on both sides of the curable silicone resin sheet to expose the curable silicone resin sheet surface, or by peeling off both release films to expose only the curable silicone resin sheet, without worrying about damaging the formed curable silicone resin sheet.

[0138] The substrate for the release film used in step 3 is not particularly limited, and examples include cardboard, corrugated cardboard, clay-coated paper, polyolefin laminate paper, especially polyethylene laminate paper, synthetic resin film / sheet, natural fiber fabric, synthetic fiber fabric, artificial leather fabric, and metal foil. Synthetic resin films or sheets are particularly preferred, and examples of synthetic resins include polyimide, polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polycarbonate, polyethylene terephthalate, and nylon. When heat resistance is particularly required, films of heat-resistant synthetic resins such as polyimide, polyetheretherketone, polyethylene naphthalate (PEN), liquid crystal polyarylate, polyamideimide, and polyethersulfone are suitable. On the other hand, in applications where visibility is required, such as display devices, transparent substrates, specifically transparent materials such as polypropylene, polystyrene, polyvinylidene chloride, polycarbonate, polyethylene terephthalate, and PEN, are suitable. As indicated by the statement that cardboard and the like can be used as the substrate, the term "release film" is not particularly limited in terms of its thickness.

[0139] As mentioned above, there are no particular restrictions on the thickness of the release film, but it is usually around 5 to 300 μm.

[0140] The release film has at least one release layer on its surface, and it is preferable that in step 3 the release film is used so that the release layer comes into contact with the mixture obtained in step 2. This allows the curable hot melt silicone composition sheet obtained by pressure molding through steps 3 and 4 to be easily peeled off the release film. The release layer may also be called a release liner, separator, mold release layer, or release coating layer, and preferably it may be a release layer formed using a material having release coating ability such as a silicone-based release agent, a fluorine-based release agent, an alkyd-based release agent, or a fluorosilicone-based release agent. Alternatively, the release film may be made easily peelable off the curable hot melt silicone composition sheet by forming fine physical irregularities on the surface of the base film, or by using a material that does not adhere well to the curable hot melt silicone composition sheet of the present invention as the material for the base film.

[0141] In step 3, the mixture obtained in step 2 is interposed between two release films to form a laminate. The process is not particularly limited, but the mixture obtained in step 2 is supplied by extruding or coating onto the release layer of one release film, the mixture is placed on the release layer, and then the release layer of another release film is laminated onto the mixture to form a laminate. In order to continuously produce a curable silicone composition sheet by continuously performing the process of placing the mixture on one release sheet and then stacking another release sheet on top of the mixture, each release film is transported via a rotary roll to the supply position of the mixture obtained from step 2, the mixture is supplied between the two release films, and the two release films and the mixture are laminated to form a laminated structure of release film / mixture (i.e., curable hot melt silicone composition) / release film.

[0142] In the continuous method described above, the amount of the mixture obtained in step 2 supplied between the release films in step 3 can be designed according to the manufacturing speed and scale of the laminate. For example, the mixture obtained in step 2 can be supplied between the release films at a rate of 1 to 10 kg / hour, but it is not limited to this. However, the amount or rate of the mixture supplied when the mixture obtained in step 2 is interposed between the release films in step 3 to form the laminate must be determined according to the average thickness of the curable silicone composition sheet designed in step 4, and the amount or rate of the mixture supplied must be within a range that allows the laminate obtained in step 3 to be further pressurized in step 4 to process the curable silicone composition sheet to the desired thickness.

[0143] If the heat-melt viscosity of the mixture obtained in step 1 is low and the molten material is highly fluid, it is preferable in step 3 to extrude the heat-melted mixture obtained in step 2 onto one release film while forming it into a film using a die, and then place another release film on top of the extruded mixture to form a laminate. Here, the die is used to pre-form the mixture, and there are no particular restrictions on the type of die or the thickness of the mixture during pre-formation, but it is preferable to use a T-type die to pre-form the mixture into a substantially sheet-like form with a thickness in the range of 100 to 2000 μm (= 2 mm).

[0144] If the heating and melting viscosity of the mixture obtained in step 1 is low and the molten material is highly fluid, it is preferable to include a step of cooling or temperature-controlling the entire laminate obtained in step 3 as a pre-step to step 4 or in step 4 after the above-mentioned preliminary molding. This is to effectively carry out the pressure molding in step 4 by cooling the heated molten material to a state of high viscosity or solidity. The cooling step is not particularly limited, but it can be carried out by cooling the mixture supplied or laminated on the film by a cooling roll or the like in the range of -50°C to room temperature using cooling means such as air cooling or a cooling solvent. Details of temperature control will be explained in step 4.

[0145] On the other hand, when the heat-melt viscosity of the mixture obtained in Step 1 is high and the fluidity is poor, in Step 3, a mixture with poor fluidity, for example, a semi-solid mixture, may be supplied onto a film without performing preforming and laminated with a release film.

[0146] [Step 4] Step 4 is a step of pressing the laminate obtained in Step 3 between rolls to form a curable hot-melt silicone composition sheet having a predetermined film thickness. It is a step of pressure-extending the mixture obtained in Step 2 from the release film of the laminate obtained in Step 3 into the form of a curable silicone composition sheet having a substantially uniform thickness.

[0147] The pressure-extending forming of the curable hot-melt silicone composition sheet interposed between the release films in Step 4 can be performed on the laminate obtained in Step 3 using a known rolling method such as roll rolling. In particular, in the case of roll rolling, there is an advantage that a curable hot-melt silicone composition sheet having a desired thickness can be designed by adjusting the gap between the rolls. For example, by adjusting the gap between the rolls to be constant within the range of an average thickness of 10 to 2000 μm and pressing the laminate to roll the curable silicone composition sheet, a curable hot-melt silicone composition sheet having excellent flatness and extremely few defects such as voids on the sheet surface and inside the sheet can be obtained. More specifically, in the case of roll rolling, it is particularly preferable that the gap between the rolls is adjusted within the range of 1.5 to 4.0 times the average thickness of the target curable hot-melt silicone composition sheet.

[0148] In step 4, the laminate is pressurized and the curable hot-melt silicone composition sheet in the laminate is stretched to obtain a substantially flat curable hot-melt silicone composition sheet with a thickness of 10 to 2000 μm. In step 3, the mixture after heating and melting in step 2 is roll-stretched in a sandwiched form between release films to obtain a release laminate containing a hot-melt curable silicone composition sheet that has low defects and excellent handling properties due to easy peeling from the release sheet.

[0149] [Temperature control in step 4] In step 4, when the laminate obtained in step 3 is pressed between rolls to stretch the curable hot melt silicone composition sheet, it is preferable that the rolls are further equipped with a temperature control function to control the temperature of the entire laminate during roll rolling, and to heat or cool it as needed. This temperature control has the practical benefit of maintaining a stable gap between the rolls and improving the flatness and uniformity (uniformity of film thickness) of the resulting curable hot melt silicone composition sheet. The specific temperature control range can be appropriately designed depending on the heat resistance of the release film used, the thickness of the curable hot melt silicone composition sheet (design thickness), the reactivity of the curable hot melt silicone composition, etc., but is generally within the range of 5 to 150°C.

[0150] [Cutting process] Step 4 provides a release laminate in which a curable hot-melt silicone composition sheet is interposed between release films. The method for manufacturing the laminate of the present invention may optionally further include a step of cutting the laminate containing the curable hot-melt silicone composition sheet. Alternatively, instead of the cutting step, or in conjunction with the cutting step, the curable hot-melt silicone composition sheet may be wound into a roll shape, for example, using a winding device. This makes it possible to obtain a release laminate containing a curable hot-melt silicone composition sheet of a desired size.

[0151] [Laminated structure] The laminate obtained by the above process is a laminate having a structure in which a substantially flat, curable hot-melt silicone composition sheet, 10 to 2000 μm thick, containing the above-mentioned components (A) to (D) as essential components and possibly component (E) as an optional component, is laminated between two release films having at least one release surface. Preferably, both release films have a surface structure or surface treatment that enhances release properties.

[0152] [Curing hot melt silicone composition sheet] The curable hot-melt silicone composition sheet obtained by the manufacturing method of the present invention is a curable silicone composition containing the above-mentioned components (A) to (D) and optionally component (E), and is hot-melt. The curable hot-melt silicone composition sheet of the present invention can be used as a heat-meltable adhesive, sealant, and / or bonding agent. In particular, the curable hot-melt silicone composition sheet has excellent moldability, gap-filling properties, and adhesive strength, and can be used as a die-attach film or film adhesive. It can also be suitably used as a curable hot-melt silicone composition sheet for compression molding or press molding.

[0153] Specifically, after peeling the curable hot-melt silicone composition sheet obtained by the manufacturing method of the present invention from the release film, it is placed on a desired location such as a semiconductor, and a film adhesive layer is formed on and between the adherends, taking advantage of the gap-filling properties for uneven surfaces and gaps, thereby performing temporary fixing, positioning, and bonding between the adherends. Furthermore, the curable hot-melt silicone composition layer is heated to 150°C or higher to cure, and the adherends can be bonded together by forming a cured product of the curable silicone sheet between the adherends. Note that the release film may be peeled off after the curable hot-melt silicone composition sheet has been heated to form a cured product, and the timing of peeling the release film from the curable silicone composition or the cured product obtained therefrom may be selected depending on the application and method of use of the curable silicone composition sheet.

[0154] Because the curable silicone composition sheet has hot-melt properties, heating the sheet before final curing softens or fluidizes it, allowing it to fill any unevenness or gaps on the adherend surface, forming a bonded surface with the adherend. Various constant-temperature baths, hot plates, electromagnetic heating devices, heating rolls, etc., can be used to heat the curable hot-melt silicone composition sheet. To more efficiently bond the adherend to the curable silicone composition sheet and heat the curable silicone composition, electric heat presses, diaphragm laminators, roll laminators, etc., are preferably used.

[0155] [Method for forming hardened material] This curable hot melt silicone composition can be cured by a method comprising at least the following steps (I) to (III). (I) A step of heating the composition to 100°C or higher to melt it; (II) A step of injecting the molten curable hot melt silicone composition obtained in step (I) into a mold, or a step of spreading the molten curable hot melt silicone composition obtained in step (I) into the mold by clamping the mold; and (III) A step of curing the curable hot melt silicone composition injected into the mold in step (II).

[0156] In the above process, a transfer molding machine, compression molding machine, injection molding machine, auxiliary ram molding machine, slide molding machine, double ram molding machine, or low-pressure sealing molding machine can be used. In particular, the composition of the present invention can be suitably used to obtain a cured product by transfer molding and compression molding.

[0157] Finally, in step (III), the curable hot melt silicone composition injected (applied) to the mold in step (II) is cured. The temperature for curing the curable hot melt silicone composition of the present invention is not particularly limited as long as the composition can be cured within the desired time, but it is preferably 100°C or higher, or 130°C or higher.

[0158] On the other hand, as described above, the curable hot-melt silicone composition of the present invention can be formed into a thin film sheet with a thickness in the range of 100 to 1000 μm by sandwiching it between two release films and forming it to a predetermined thickness by passing it through two rolls or the like. The thin film sheet made of this curable hot-melt silicone composition can be used as a die-attach film for the manufacture of semiconductor chips and the like, or as a film-type curable silicone adhesive.

[0159] [Uses of the composition] The curable hot-melt silicone composition of the present invention has hot-melt properties, excellent handling and curability during melting (hot-melting), and excellent color resistance at high temperatures of the cured product obtained by curing this composition. Therefore, it is useful for semiconductor components such as encapsulants and light reflectors for light-emitting / optical devices, and for optoelectronic semiconductors having the cured product. Furthermore, because the cured product has excellent mechanical properties, it is suitable as a encapsulant for semiconductors; a encapsulant for power semiconductors such as SiC and GaN; and as an adhesive, potting agent, protective agent, and coating agent for electrical and electronic applications. In addition, the curable hot-melt silicone composition of the present invention in sheet form is suitable as a material for encapsulating and bonding large-area substrates using press molding, compression molding, or vacuum laminators. In particular, it is suitable for use as a encapsulant for semiconductors using the overmolding method during molding. Furthermore, the composition in sheet form can be used as a curable film adhesive or as a stress buffering layer between two substrates with different coefficients of thermal expansion.

[0160] Furthermore, the curable hot-melt silicone composition of the present invention, in particular the sheet-like curable hot-melt silicone composition, can be used for large-area encapsulation of semiconductor substrates (including wafers). Moreover, a sheet formed by molding the curable hot-melt silicone composition of the present invention can be used for die-attach films, encapsulation of flexible devices, stress-relieving layers for bonding two different substrates, and the like.

[0161] [Viscosity properties of the composition at high temperatures (thixotropy)] The curable silicone composition of the present invention is hot-meltable, fluid at temperatures above 100°C, and its viscosity can be measured. Furthermore, its viscosity strongly depends on the shear force applied during measurement; it exhibits thixotropy, meaning that viscosity is high at low shear and low at high shear. Specifically, at 100°C and 150°C, as measured by a rheometer, the shear rate was 1s. -1 The viscosities at 5000 Pas or less and 1000 Pas or less are respectively, and the viscosities at 100°C and 150°C, when using a flow tester considered to represent the extreme shear rate at a pressure of 2.5 MPa, are 500 Pas or less and 100 Pas or less, respectively. Such viscosity characteristics are advantageous in the process of temporarily bonding a curable hot melt silicone composition to a substrate using a vacuum laminator or vacuum low-pressure press, followed by static curing in an oven. In other words, during temporary bonding, pressure is instantaneously applied under constant temperature conditions to bond with the substrate. At this time, the viscosity decreases due to the applied pressure, resulting in excellent gap-filling properties for substrates with many irregularities. However, when static curing is performed in an oven afterward, no pressure is applied, so even when curing at temperatures above 150°C, the viscosity remains high, preventing dripping of the composition before curing begins.

[0162] [Curing conditions for the composition] The curable hot-melt silicone composition of the present invention hardens when left at room temperature or when heated. When hardening in a mold during a molding process, heating to a temperature of 150°C or higher for a short time to pre-harden improves the production cycle time. For unhardened curable hot-melt silicone compositions, curable hot-melt silicone composition sheets pre-pressed onto a substrate, and cured products obtained by pre-hardening the curable hot-melt silicone composition after application to a substrate, it is preferable to harden them at a temperature of 150°C or higher for at least one hour to complete the hardening reaction.

[0163] [Viscoelastic properties of cured materials] The cured product obtained by curing the curable hot-melt silicone composition of the present invention exhibits characteristic viscoelastic properties. When the dynamic viscoelasticity of a typical silicone cured product is measured while varying the temperature, it differs depending on the silicone's network structure and the type of functional groups, but it shows a sharp glass transition at a certain temperature. That is, the tanδ curve, which is the ratio of the storage modulus to the loss modulus, shows a sharp peak at a certain temperature. Generally, a high tanδ value means that the force applied to the material is dispersed (relaxed), so materials with a high tanδ can be said to have excellent stress relaxation properties. However, the cured product made from the composition of the present invention does not show a sharp tanδ peak at a certain temperature, but rather exhibits a high tanδ value over a wide temperature range (Figure 1). For example, if the composition is cured at 150°C, the cured product retains a thermal history of a 125°C temperature difference before returning to room temperature (25°C). When integrally molded with a substrate with a low coefficient of linear expansion, thermal stress is generated within this temperature range. If tanδ is low across the entire temperature range, or if there is a very sharp peak in tanδ within this range, thermal stress will continue to accumulate in the material over the specified temperature range, or even if stress relaxation begins when the material enters a high tanδ region, it will quickly exit that region, preventing sufficient relaxation. On the other hand, if tanδ is high over a wide temperature range, as in the cured product obtained by curing the composition of the present invention, this thermal stress will relax over time, greatly reducing warping that occurs when using thin substrates. In other words, when a large area of ​​thin substrate is sealed together using a curable silicone composition sheet made from the composition of the present invention, warping is less likely to occur because the thermal stress is relaxed. This characteristic is exhibited when a high tanδ is obtained over a wide temperature range when measuring the dynamic viscoelasticity of the cured product, and the behavior of tanδ can be controlled by adjusting the crosslinking density of the cured product by changing the molecular structure and combination ratio of component (A) (or components (A1) and (A2)), component (B), and component (C).

[0164] [Hardness of hardened material] The preferred hardness of the cured product obtained by curing the curable hot melt silicone composition of the present invention is classified into two categories depending on its application. When the curable hot melt silicone composition sheet of the present invention is bonded to an adherend on both sides, it is preferable that the Type A durometer hardness specified in JIS K 7215-1986 "Durometer Hardness Test Method for Plastics" is 40 or higher. This is because if the hardness is below the above lower limit, the cured product tends to be too soft and brittle. On the other hand, when the application is substrate sealing, it is preferable that the Type A durometer hardness is 60 or higher. This is because if the hardness is below the above lower limit, the surface of the cured product becomes sticky, reducing its handling properties.

[0165] [Uses of hardened material] The uses of the cured product obtained by curing the curable hot-melt silicone composition of the present invention are not particularly limited. The composition of the present invention has hot-melt properties, excellent moldability and mechanical properties, and the cured product exhibits the characteristic elastic modulus behavior at room temperature to high temperatures described above. For this reason, the cured product obtained by curing this composition can be suitably used as a component for semiconductor devices, and can be suitably used as a encapsulant for semiconductor elements and IC chips, and as an adhesive / bonding member for conductive devices.

[0166] The semiconductor device comprising a component made from a cured product obtained by curing the curable silicone composition of the present invention is not particularly limited, but it is especially preferable that it be a light-emitting semiconductor device, such as a light-emitting / optical device. Since the cured product of the present invention has excellent color resistance at high temperatures, it can be more suitably used as a encapsulant in optical semiconductor devices where transparency is important. [Examples]

[0167] The curable hot-melt silicone composition and its manufacturing method of the present invention will be described in detail below with reference to examples and comparative examples. In the following description, Me, Vi, and Ph in the average unit formulas represent methyl group, vinyl group, and phenyl group, respectively. Furthermore, the softening point, curability, and storage stability of the curable silicone composition of each example and comparative example were measured by the following method. The results are shown in Table 1.

[0168] [Softening point] A curable hot-melt silicone composition was molded into cylindrical pellets measuring φ14mm x 22mm. These pellets were placed on a hot plate set to 25°C to 100°C, and a 100-gram load was applied from above for 10 seconds. After removing the load, the deformation of the pellets was measured. The temperature at which the deformation in the height direction exceeded 1 mm was defined as the softening point.

[0169] [Curing properties] The curing properties of a curable silicone composition were measured by vulcanizing it for 600 seconds at the molding temperature (160°C) using a curameter (PREMIER MDR, manufactured by Alpha Technologies) according to the method specified in JIS K 6300-2:2001 "Unvulcanized rubber - Physical properties - Part 2: Method for determining vulcanization properties by vibrating vulcanization tester". For the measurement, approximately 5g of the curable hot-melt silicone composition was weighed, sandwiched between 50μm thick PET films, placed on the lower die, and the measurement began when the upper die closed. A rubber-type R die was used, with an amplitude angle of 0.53°, a vibration frequency of 100 times / min, and a torque range of the maximum 230 kgf·cm. The measurement result was recorded in seconds as the time required to exceed a torque value of 1 dNm (ts-1). [Storage stability] The curable silicone composition was aged in an oven at 40°C for one week, and the curing properties were measured using the method described above, and the value of ts-1 was read.

[0170] Hot-melt mixtures of organopolysiloxane resin and linear organopolysiloxane were prepared using the methods shown in Reference Examples 1 to 7 below, and their heat loss (=mass loss rate) was evaluated. In the examples and comparative examples, a large amount of curing retarder was intentionally added to reproduce an environment in which curing inhibition occurs. As a result, it was found that if the curable silicone composition does not have sufficient crosslinking ability, it will not cure under the specified curing conditions.

[0171] [Reference example 1] At 25°C, it is a white solid, with the average unit formula: (Me2ViSiO 1 / 2 ) 0.05 (Me3SiO 1 / 2 ) 0.39 (SiO 4 / 2 ) 0.56 (HO 1 / 2 ) 0.02 Organopolysiloxane resin represented by (vinyl group content = 1.9% by mass) (hereinafter referred to as "Si resin a1") 1.37 kg At 25°C, it is a white solid, with the average unit formula: (Me3SiO 1 / 2 ) 0.44 (SiO 4 / 2 ) 0.56 (HO 1 / 2 ) 0.02 5.47 kg of organopolysiloxane resin represented by (vinyl group content = 0% by mass) (hereinafter referred to as "Si resin a2"), and formula: ViMe2SiO (Me2SiO) 800 SiViMe2 Dimethylpolysiloxane with dimethylvinylsiloxy groups sealed at both ends of the molecular chain (vinyl group content = 0.09% by mass) (hereinafter referred to as "Si polymer b") 2.83 kg, The compound was dissolved in 4.00 kg of xylene using a three-one motor in a pail. The resulting solution was fed into a twin-screw extruder set to a maximum temperature of 230°C, and the xylene and low molecular weight organopolysiloxane components were removed under a vacuum of -0.08 MPa, yielding a hot-melt, transparent mixture 1. Mixture 1 was collected in a cylindrical pail and allowed to cool and solidify. The amount of volatile components in this mixture was measured at 200°C for 1 hour and found to be 0.7% by mass.

[0172] [Reference examples 2~7] Mixtures 2 to 7 were obtained in the same manner as in Reference Example 1, except that the amounts of Si resin a1, Si resin a2, and Si polymer b were changed as shown in the table below. When the amount of volatile components in these mixtures was measured under conditions of 200°C for 1 hour, all were found to be 0.7% by mass. [Table 1]

[0173] [Organohydrogenpolysiloxane] The following examples and comparative examples used the following organohydrogenpolysiloxanes (SiHsiloxane c1-c5). SiH siloxane c1: (PhSiO 3 / 2 ) 0.4 (HMe2SiO 1 / 2 ) 0.6 Organohydrogenpolysiloxane represented by (amount of volatile components, i.e., mass loss rate, after aging in an oven at 100°C under atmospheric pressure for 1 hour, is 3.4% by mass) SiH siloxane c2: (HMe2SiO 1 / 2 ) 0.52 (Me2SiO 2 / 2 ) 0.15 (SiO 4 / 2 ) 0.33 Organohydrogenpolysiloxane represented by (amount of volatile components, i.e., mass loss rate, after aging in an oven at 100°C under atmospheric pressure for 1 hour, is 2.9% by mass) SiH siloxane c3: Me3SiO(Me2SiO) 37 (MeHSiO) 37 SiMe3 Organohydrogenpolysiloxane represented by (amount of volatile components, i.e., mass loss rate, after aging in an oven at 100°C under atmospheric pressure for 1 hour, is 2.6% by mass) SiH siloxane c4: Me3SiO(MeHSiO)7(Me2SiO) 6.5 SiMe3 Organohydrogenpolysiloxane represented by (amount of volatile components, i.e., mass loss rate, after aging in an oven at 100°C under atmospheric pressure for 1 hour, is 12.7% by mass) SiH siloxane c5: HMe2SiO(Me2SiO) 17 SiMe2H Organohydrogenpolysiloxane represented by (amount of volatile components, i.e., mass loss rate, after aging in an oven at 100°C under atmospheric pressure for 1 hour, is 8.3% by mass) SiH siloxane c6: (HMe2SiO 1 / 2 ) 0.67 (SiO 4 / 2 ) 0.33 Organohydrogenpolysiloxane represented by (amount of volatile components, i.e., mass loss rate, after aging in an oven at 100°C under atmospheric pressure for 1 hour, is 12.8% by mass)

[0174] [Example 1] The hot-melt mixture 1 obtained in Reference Example 1 was fed into a twin-screw extruder at 170°C using a hot melter for cylindrical pails (Nordson VersaPail melter) at a rate of 9.67 kg / hr from line 1 shown in Figure 2. next, SiH siloxane c1 0.176 kg / hr, Methyltris-1,1-dimethyl-2-propynyloxysilane (boiling point = 245°C (1012.35 hPa)) in an amount that is 3500 ppm relative to the entire composition. A mixture consisting of the above was fed through line 3-a shown in Figure 2. The set temperature of the input section was 150°C. Next, ViMe2SiO (Me2SiO) 800 SiViMe2 Dimethylpolysiloxane with dimethyl vinylsiloxy groups sealed at both ends of the molecular chain (vinyl group content = 0.09% by mass) (= "Si polymer b") 0.15 kg / hr, and A mixture consisting of a 1,3-divinyltetramethyldisiloxane solution of a platinum 1,3-divinyltetramethyldisiloxane complex (in an amount equivalent to 4.0 ppm by mass of platinum metal relative to the total composition) was fed through line 3-b in Figure 2 (the input temperature was set to 80°C), and degassing, melting, and kneading were performed in the extruder under a vacuum of -0.08 MPa. The outlet temperature of the twin-screw extruder was set to 80°C. The mixture was in the form of a semi-solid softened material. A release film (FL2-01, manufactured by Takaline Corporation) with a width of 330 mm and a thickness of 125 μm was conveyed at a speed of 1.0 m / min, and the mixture was supplied onto the release film at a supply rate of 5 kg / hr. The mixture was then interposed between two release films so that the release surface of the release film was in contact with the mixture to form a laminate (the same applies to the following examples). Subsequently, the laminate was pressed between rolls with a temperature controlled to 90°C to stretch the mixture between the release films, thereby forming a laminate in which a 300 μm thick curable hot melt silicone composition sheet was interposed between two release films. The entire laminate was then cooled by air cooling. The configuration of the manufacturing apparatus is shown in Figure 2. When the release film was peeled off the obtained laminate, a bubble-free, flat, homogeneous, tack-free, transparent curable hot melt silicone composition sheet was obtained, and its softening temperature was 80°C. The curability of the obtained curable hot melt silicone composition sheet at 160°C was measured using the method described above, and its ts-1 was 194 seconds. After aging this curable hot melt silicone composition sheet in a 40°C oven for one week and measuring its curability again, its ts-1 at 160°C was 190 seconds. The obtained curable hot-melt silicone composition sheet was heat-cured at 160°C for 2 hours by hot pressing. The resulting cured material was cut to a size of 3 cm × 1 cm × 0.1 cm, and its temperature-dependent viscoelastic properties were measured using a rheometer (MCR-302, manufactured by Anton Paar) at a frequency of 1 Hz in the range of -50°C to 200°C. The results are shown in Figure 1.

[0175] [Examples 2-8, Comparative Examples 1-4] Except for using the mixture obtained in the reference example shown in the table below instead of mixture 1, and using the organohydrogenpolysiloxane (feed amount) shown in the table below for SiH siloxane c1, the same procedure as in Example 1 was followed to obtain a bubble-free, flat, homogeneous, tack-free, transparent, curable hot-melt silicone composition sheet. The softening point temperature (°C) and ts-1 (seconds) (initial / after storage at 40°C for 1 week) are also shown in the table. For Example 8 and Comparative Example 4, 1-ethynyl-1-cyclohexanol (boiling point = 174°C (1013.25 hPa)) was used instead of methyltris-1,1-dimethyl-2-propinyloxysilane (boiling point = 245°C (1012.35 hPa)) for testing. [Table 2] *1-ethinyl-1-cyclohexanol is used as an inhibitor.

[0176] [Comparative Example 5] At 25°C, it is a white solid, with the average unit formula: (Me2ViSiO 1 / 2 ) 0.05 (Me3SiO 1 / 2 ) 0.39 (SiO 4 / 2 ) 0.56 (HO 1 / 2 ) 0.02 Organopolysiloxane resin represented by (vinyl group content = 1.9% by mass) 32.5g, At 25°C, it is a white solid, with the average unit formula: (Me3SiO 1 / 2 )0.44 (SiO 4 / 2 ) 0.56 (HO 1 / 2 ) 0.02 Organopolysiloxane resin represented by (vinyl group content = 0% by mass) 32.5g, and formula: ViMe2SiO (Me2SiO) 800 SiViMe2 Dimethylpolysiloxane with dimethylvinylsiloxy groups sealed at both ends of the molecular chain (vinyl group content = 0.09% by mass), represented as 28.0 g. It was dissolved in 15 g of xylene in a flask. To the resulting mixed solution, formula: Me3SiO(MeHSiO)7(Me2SiO) 6.5 SiMe3 2g of organohydrogenpolysiloxane represented by (the amount of volatile components, i.e., the mass reduction rate, was 12.7% by mass after aging in an oven at 100°C under atmospheric pressure for 1 hour), formula: HMe2SiO(Me2SiO) 17 SiMe2H 5g of organohydrogenpolysiloxane represented by (the amount of volatile components, i.e., the mass reduction rate, was 8.3% by mass after aging in an oven at 100°C under atmospheric pressure for 1 hour), 1-Ethynyl-1-cyclohexanol (boiling point = 174°C (1013.25 hPa)) in an amount that is 500 ppm relative to the entire composition, and A 1,3-divinyltetramethyldisiloxane solution of a platinum 1,3-divinyltetramethyldisiloxane complex (an amount equivalent to 4.0 ppm by mass of platinum metal relative to the entire composition) The mixture was added and mixed in a flask at room temperature to obtain a homogeneous liquid composition. The resulting mixture was coated onto a PET film to a thickness of 300 μm and heated at 120°C for 30 minutes to remove xylene, resulting in a film-like composition. However, its tackiness was too strong, making it difficult to handle. Furthermore, the resulting sheet had a xylene odor, indicating that this method could not completely remove xylene.

[0177] [Summary] The curable silicone compositions of Examples 1 to 8 according to the present invention can be made less susceptible to curing inhibition by using organohydrogenpolysiloxanes having a specific structure. Furthermore, since these organohydrogenpolysiloxanes have few volatile components at 100°C under atmospheric pressure (especially 1 atm), even when the raw materials are melt-kneaded under reduced pressure to prepare the curable silicone compositions of the present invention, the active ingredients involved in the hydrosilylation reaction hardly volatilize, or if they do volatilize, the amount is small, thus making it possible to obtain curable silicone compositions with the desired properties. In addition, by using the curable silicone compositions of the present invention, it was possible to produce void-free, flat, homogeneous, tack-free, transparent curable hot-melt silicone composition sheets with a thickness of 300 μm. Furthermore, the results of Example 8 showed that by using a curing retarder with a boiling point of 200°C or higher at atmospheric pressure (especially at 1 atmosphere), even when melting and kneading the curable silicone composition under reduced pressure, the retarder did not volatilize, or the amount of volatilization was extremely small, resulting in a curable hot melt silicone composition sheet with good storage stability. In contrast, as shown in Comparative Examples 1 to 4, when organohydrogenpolysiloxanes with a large amount of volatile components at 100°C under atmospheric pressure are used, the active ingredients volatilize beyond an acceptable range during the process of melting and kneading the curable silicone composition under reduced pressure, resulting in the inability to obtain the target curing characteristics of the curable hot melt silicone composition. It was also found that if the organohydrogenpolysiloxane with the specific structure used in the present invention is not used, the curing of the curable hot melt silicone composition becomes significantly slower in the presence of curing inhibitors. [Explanation of symbols]

[0178] 1: Hot melter 2: Extruder 3-a: Pump 3-b: Pump 3-c: Vacuum pump 4-a: Release sheet 4-b: Release sheet 5-a: Stretching roll (may optionally be equipped with a temperature control function) 5-b: Stretching roll (may optionally be equipped with a temperature control function) 6: Cooling Roll 7: Film Thickness Gauge 8: Sheet cutter 9: Foreign object inspection machine

Claims

1. (A) 100 parts by mass of organopolysiloxane resin containing the following components (A1) and (A2) in a mass ratio of 0:100 to 90:10 (A1) Having a hardening-reactive functional group containing a carbon-carbon double bond within the molecule, and SiO ４／２ An organopolysiloxane resin that is solid at 25°C and does not have hot-melt properties on its own, containing at least 20 mol% or more of siloxane units represented by , (A2) It does not have a hardening-reactive functional group containing a carbon-carbon double bond within the molecule, and SiO ４／２ An organopolysiloxane resin that is solid at 25°C and does not have hot-melt properties on its own, containing at least 20 mol% or more of siloxane units represented by , (B) 10 to 100 parts by mass of a linear or branched organopolysiloxane having a curing-reactive functional group containing at least two carbon-carbon double bonds in the molecule, and being liquid or plastic at 25°C. (C) The following average empirical formula (1): (R 4 3 SiO 1 / 2 ) a (R 5 2 SiO 2 / 2 ) b (R 5 SiO 3 / 2 ) c (SiO 4 / 2) d (1) (In the formula, R4 and R5 are each independently unsubstituted or substituted monovalent hydrocarbon groups having 1 to 12 carbon atoms and not containing aliphatic unsaturated bonds, at least two of the total R4 atoms are hydrogen atoms, and a, b, c, and d are numbers satisfying the conditions 0.01 ≤ a ≤ 0.6, 0 ≤ b, 0 ≤ c ≤ 0.9, 0 ≤ d ≤ 0.9, and a + b + c + d = 1 and c + d ≥ 0.2.) It is represented as, and, The following is the average composition formula (2): (HR ６ ２ SiO １／２ ) ｅ (R ６ ２ SiO ２／２ ) ｆ (SiO ４／２ ) ｇ (2) (In the formula, R ６ Each of these is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms and not containing an aliphatic unsaturated bond, and e, f, and g are numbers satisfying the conditions 0.01 ≤ e ≤ 0.6, 0 ≤ f ≤ 0.9, 0.2 ≤ g ≤ 0.9, and e + f + g = 1. Organohydrogenpolysiloxanes represented by, Represented by the above average empirical formula (1), and the following average empirical formula (3): (HR) ７ ２ Yes １／２ ) ｈ (R ７ ２ Yes ２／２ ) ｉ (R ８ Yes ３／２ ) ｊ (3) (In the formula, R ７ and R ８ Each of these is independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms and not containing an aliphatic unsaturated bond, and all R ８ At least 10 mol% of the compound is an aryl group, and h, i, and j are numbers that satisfy the following conditions: 0.01 ≤ h ≤ 0.6, 0 ≤ i ≤ 0.9, 0.2 ≤ j ≤ 0.9, and h + i + j = 1. Organohydrogensiloxane Selected from the above, organohydrogenpolysiloxane (an amount such that the number of hydrogen atoms bonded to silicon atoms per alkenyl group bonded to silicon atoms in the entire curable silicone composition is 0.5 to 20.0), which has a mass loss rate of 3.4% by mass or less compared to the pre-exposure state after exposure to 100°C for 1 hour under atmospheric pressure. (D) Hydrosilylation reaction catalyst: an amount sufficient to cure this composition, and (E) A curing retarder for hydrosilylation reactions having a boiling point of 200°C or higher under atmospheric pressure, containing 1 to 5000 ppm based on the total mass of the composition. Furthermore, the above-mentioned components (A) and (B) are added in the form of a mixture, and the amount of volatile components measured for the mixture under the conditions of 200°C for 1 hour is 0.7% by mass. A curable silicone composition characterized by having hot-melt properties as a whole.

2. The aforementioned component (C) is, (c1)(PhSiO ３ / ２ ) ０.４ (HMe ２ SiO １ / ２ ) ０.６ Organohydrogenpolysiloxane represented by (mass loss rate after aging in an oven at 100°C under atmospheric pressure for 1 hour: 3.4% by mass), and (c2) (HMe ２ SiO １ / ２ ) ０.５２ (Me ２ SiO ２／２ ) ０．１５ (SiO ４ / ２ ) ０.３３ Organohydrogenpolysiloxane represented by (mass loss rate after aging in an oven at 100°C under atmospheric pressure for 1 hour: 2.9% by mass) It is characterized by being one or more types selected from, The curable silicone composition according to claim 1.

3. The above component (A1) is (A1-1) given by the following average unit formula: (R １ ３ SiO １／２ ) ａ (R １ ２ SiO ２／２ ) ｂ (R １ SiO ３／２ ) ｃ (SiO ４／２ ) ｄ (R ２ O １／２）ｅ (In the formula, each R １ R is a monovalent hydrocarbon group having 1 to 10 carbon atoms independently, provided that all R in one molecule １ Of these, 1 to 12 mol% are alkenyl groups; each R ２ a, b, c, d, and e are numbers satisfying the following conditions: 0.10 ≤ a ≤ 0.60, 0 ≤ b ≤ 0.70, 0 ≤ c ≤ 0.80, 0 ≤ d ≤ 0.65, 0 ≤ e ≤ 0.05, where c + d > 0.20 and a + b + c + d = 1. This is an organopolysiloxane resin that, on its own, does not possess hot-melt properties. The above component (A2) is (A2-1) given by the following average unit formula: (R ３ ３ SiO １／２ ) ｆ (R ３ ２ SiO ２／２ ) ｇ (R ３ SiO ３／２ ) ｈ (SiO ４／２ ) ｉ (R ２ O １／２）ｊ (In the formula, each R ３ R is a monovalent hydrocarbon group that independently has 1 to 10 carbon atoms and does not contain a carbon-carbon double bond; ２ (where is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; f, g, h, i, and j are numbers satisfying the following: 0.35 ≤ f ≤ 0.55, 0 ≤ g ≤ 0.20, 0 ≤ h ≤ 0.20, 0.45 ≤ i ≤ 0.65, 0 ≤ j ≤ 0.05, and f + g + h + i = 1) This is an organopolysiloxane resin that, on its own, does not possess hot-melt properties. The aforementioned component (B) has the following structural formula: (B1) R ４ ３ SiO(SiR ４ ２ O) ｋ SiR ４ ３ (In the formula, each R ４ R is a monovalent hydrocarbon group having 1 to 10 carbon atoms independently, provided that R in one molecule ４ (At least two of them are alkenyl groups, and k is a number between 20 and 5,000.) It is a linear diorganopolysiloxane represented by A curable silicone composition according to any one of claims 1 to 2.

4. A curable silicone composition sheet or film comprising the curable silicone composition according to any one of claims 1 to 3.

5. A curable silicone composition sheet or film according to claim 4, having a thickness between 10 and 1000 μm.

6. A sheet or film-like adhesive comprising a curable silicone composition sheet or film according to claim 4 or 5.

7. A sheet or film-like sealant comprising a curable silicone composition sheet or film according to claim 4 or 5.

8. A curable silicone composition sheet or film according to claim 4 or 5, A peelable laminate comprising a sheet or film-like substrate having a release surface facing the curable silicone composition sheet or film, which is attached to one or both sides of the sheet or film-like substrate, wherein the curable silicone composition sheet or film is peelable from the sheet or film-like substrate having a release surface.

9. A laminate comprising a substrate which is an electronic component or its precursor, and a curable silicone composition layer formed by adhering at least one side of a curable silicone composition sheet or film according to claim 4 or 5 to a part or all of the surface of the substrate, wherein the curable silicone composition is in an uncured state.

10. A cured product obtained by curing a curable silicone composition according to any one of claims 1 to 3.

11. Use of the cured product according to claim 10 as a component for a semiconductor device or a component for an optoelectronic device.

12. A semiconductor device or optoelectronic device having the cured product described in claim 10.

13. A method for manufacturing a laminate according to claim 9, characterized in that at least one surface of an uncured curable silicone composition sheet or film is brought into close contact with a part or all of a substrate which is an electronic component or its precursor, by one or more means selected from a vacuum laminator, a vacuum press, and compression molding.

14. A method for producing a laminate including a cured silicone composition layer, comprising the step of curing an uncured curable silicone composition by heating the laminate according to claim 9.

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