Curable organosilicon composition, cured product thereof, and laminate

Abstract

The present invention provides a hot-melt curable silicone composition, a cured product thereof, and uses thereof. The curable silicone composition substantially does not require the use of organic solvents, can be cured using a relatively small amount of a condensation reaction catalyst, inhibits side reactions before and after the curing reaction, has good melt-curing properties, and thus can be cured at high speed. The cured product has practically sufficient adhesion properties and mechanical properties. A use of a hot-melt curable silicone composition and a cured product thereof. The curable silicone composition contains: a polyorganosiloxane resin having hot-melt condensation reactivity; and a mixture containing a condensation reaction catalyst at a specific ratio: a condensation reaction catalyst that is liquid at 25°C (preferably a volatile superbasic substance such as DBU) and a liquid polyorganosiloxane. The composition may further contain solid particles such as functional fillers to provide a cured product that becomes a functional member such as an optical member.

Description

Technical Field

[0001] The present invention relates to a hot-melt curable silicone composition, a cured product thereof, and a laminate including the composition or the cured product. The hot-melt curable silicone composition has good melt-curing characteristics and moldability (especially transfer moldability), and can be manufactured and used through a process that substantially does not use organic solvents as desired. Background Art

[0002] Curable silicone compositions can be cured to form cured products having excellent heat resistance, cold resistance, electrical insulation, weather resistance, water resistance, and transparency, and thus are used in a wide range of industrial fields. The cured products of such curable silicone compositions are generally less likely to change color compared to other organic materials. In addition, the physical properties thereof hardly deteriorate over time, and thus they are also suitable as optical materials and sealants and adhesives for semiconductor devices.

[0003] In particular, in recent years, especially in the manufacture of light-emitting devices and the like, the popularization of hot-melt curable silicone compositions has been promoted from the viewpoints of ease of operation and cost reduction. For example, the applicant of the present case has proposed in Patent Document 1 and Patent Document 2 hot-melt curable silicone compositions in the form of ingots and sheets, which have excellent coating moldability and are cured by a hydrosilylation reaction. These curable silicone compositions are excellent in meltability and curability / moldability as sealants, but the use of organic solvents such as toluene is indispensable in their manufacturing process, and in addition, they sometimes cannot be applied in transfer molding processes that require rapid curability after heating and melting.

[0004] On the other hand, a curable composition is proposed in Patent Document 3, which contains a so-called resin - a linear organosiloxane block copolymer and a superbase catalyst (condensation reaction catalyst) such as diazabicycloundecene (DBU), and the curable composition has melt processability. However, with respect to the condensation reaction curable composition, if a large amount of the condensation reaction catalyst is not used, the melt curability may sometimes be impaired. However, if the amount of the condensation reaction catalyst used increases, the polyorganosiloxane resin having condensation reactivity may polymerize by side reactions, which may impair the hot melt property and melt curability. In addition, sometimes an unintended condensation reaction is caused after the curing reaction, the physical properties of the cured product are reduced, or phenyl groups in the hot melt polyorganosiloxane resin are broken by the superbase catalyst, generating benzene and the like. In particular, in a curing system containing solid particles, pigments and other functional fillers, when using the above-mentioned superbase catalysts (condensation reaction catalysts) such as DBU, sometimes these functional fillers become the cause of curing hindrance. In order to have practically sufficient melt curability, it is necessary to use a large amount of the condensation reaction catalyst or to pretreat the functional fillers with a solvent, and there are problems in suppressing side reactions and process design. Moreover, it cannot be fully applied in a process without using organic solvents. It should be noted that in Patent Document 4, in order to suppress the generation of benzene caused by the breakage of phenyl groups in the polyorganosiloxane resin, it is proposed to use a specific quaternary ammonium salt in combination, but the amount of the condensation reaction catalyst used cannot be reduced or the curing hindrance cannot be suppressed, and a curable organosilicon composition having a small amount of the condensation reaction catalyst used and sufficient melt curability has not been achieved.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Pamphlet of International Publication No. 2018 / 030287

[0008] Patent Document 2: Pamphlet of International Publication No. 2018 / 030288

[0009] Patent Document 3: Japanese Patent Application Laid-Open No. 2015-505896

[0010] Patent Document 4: Pamphlet of International Publication No. 2020 / 060702 Summary of the Invention

[0011] Problems to be Solved by the Invention

[0012] The present invention is proposed to solve the above problems, and the object of the present invention is to provide a hot-melt curable silicone composition, a cured product thereof and uses thereof. The curable silicone composition substantially does not need to use an organic solvent, can be cured by using a relatively small amount of a condensation reaction catalyst, inhibits side reactions before and after the curing reaction, has good melt-curing properties, and thus can be cured at high speed. The cured product has practically sufficient adhesion properties and mechanical properties.

[0013] Solutions for solving problems

[0014] The inventors of the present invention have conducted in-depth research and found that the above problems can be solved by the following hot-melt curable silicone composition, thereby completing the present invention. The curable silicone composition contains: a polyorganosiloxane resin having a hot-melt condensation reactivity; and a mixture containing a condensation reaction catalyst containing the following substances in a specific ratio: a condensation reaction catalyst that is liquid at 25 °C (preferably a volatile superbasic substance such as DBU) and a liquid polyorganosiloxane. The composition may further contain solid particles. In particular, by using a functional filler, a cured product that becomes a functional member such as an optical member can be provided.

[0015] Advantageous effects

[0016] In the present invention, by using a mixture containing a condensation reaction catalyst containing the liquid component, a hot-melt curable silicone composition can be provided, which inhibits the interaction between a condensation reaction catalyst such as DBU and the surface of powder and the like, uses a relatively small amount of a condensation reaction catalyst, and exhibits good melt-curing properties. In addition, since the mixture containing a condensation reaction catalyst of the present invention is liquid, in the manufacturing process and use of the curable silicone composition of the present invention, an organic solvent is substantially not required, and a so-called solvent-free composition and process can be designed. Moreover, the hot-melt curable silicone composition of the present invention has good melt-curing properties even if it contains solid particles such as functional fillers, and thus can be cured at high speed, providing a cured product that not only has practically sufficient adhesion properties and mechanical properties but also has physical properties derived from functional fillers (for example, hardness, color, light transmittance, light reflectance, light scattering property, wavelength conversion property, thermal conductivity, electrical conductivity, etc.). In addition, the transfer molding property of the curable silicone composition of the present invention is excellent, and a laminate having a cured product obtained by curing the composition and their uses can be provided. Detailed embodiments

[0017] Hereinafter, the embodiments of the present invention will be described in detail.

[0018] [Hot melt]

[0019] Component (A) of the present invention and the curable silicone composition exhibit hot melt properties. Specifically, it is preferably non-flowing at 25°C, and the complex melt viscosity at 130°C is 500,000 Pa·s or less. Non-flowing means not flowing under a load-free state. For example, it represents a state below the softening point measured by the following softening point test method, which is carried out by the ring method for hot melt adhesives based on JIS K6863-1994 "Test method for softening point of hot melt adhesives". That is, in order to be non-flowing at 25°C, the softening point needs to be higher than 25°C. Preferably, the complex melt viscosity of component (A) at 130°C is 200 Pa·s or less, 100 Pa·s or less, 50 Pa·s or less, 20 Pa·s or less, or in the range of 0.10 Pa·s to 20 Pa·s. If the melt viscosity at 130°C is within the above range, the adhesion of the cured product or molded product after cooling to 25°C after hot melting is good. In addition, by using component (A) having a melt viscosity of 0.10 Pa·s to 15 Pa·s as described above, deformation and peeling of the cured product after transfer molding can sometimes be suppressed.

[0020] "Having hot melt properties" means that the whole composition is in a high-viscosity state (including raw rubber-like state where plasticity can be measured) or solid state that can maintain its shape at 25°C, and has a melt viscosity in the following range at 130°C, and has the property of softening and becoming flowable by heating. Conversely, "not having hot melt properties" means that the composition or constituent components (such as solid polyorganosiloxane resins) do not exhibit a heat melting behavior when heated alone below 200°C. Specifically, it means not having a softening point and melt viscosity below 200°C.

[0021] [Curable silicone composition]

[0022] The curable silicone composition of the present invention is characterized by containing:

[0023] (A) A polyorganosiloxane resin having a glass transition temperature (Tg) in the range of 25°C to 130°C, containing RSiO in the molecule 3 / 2 (wherein, in the formula, R is an alkyl group having 1 to 20 carbon atoms optionally substituted by a halogen atom or an aryl group having 6 to 14 carbon atoms) or SiO 4 / 2

[0024] shown siloxane units, and having at least one condensation-reactive functional group and one aromatic functional group in the molecule;

[0025] (B) A mixture containing a condensation reaction catalyst prepared by premixing the following components (B1) and (B2) in a mass ratio of 1:99 to 90:10:

[0026] (B1) A condensation reaction catalyst that is liquid at 25°C,

[0027] (B2) A linear or cyclic polyorganosiloxane that is liquid at 25°C and has a degree of polymerization of siloxane in the range of 3 to 50.

[0028] As a whole, the curable organosilicon composition is non-fluid at 25°C and has hot-melt properties.

[0029] The composition may also contain (C) solid particles, and other additives (such as tackifiers, etc.) may be incorporated as long as the technical effects of the present invention are not impaired. Among them, one of the purposes of the present invention is to be solvent-free, so during its production and use, it is preferably substantially free of organic solvents. Specifically, the content of organic solvents is less than 5% by mass of the whole composition, preferably less than 1% by mass, and particularly preferably below the detection limit (less than 0.1% by mass).

[0030] [Component (A)]

[0031] Component (A) is the main component of this composition, and when component (C) etc. are included, it is the component that becomes the binder for functional powder / filler. Specifically, component (A) contains siloxane units called T units or Q units, has a condensation-reactive functional group and an aromatic functional group in the molecule, so it has a high refractive index and hot-melt properties, thus having excellent moldability, and in the presence of component (B), it can be rapidly cured by a condensation reaction.

[0032] Such component (A) is non-fluid at 25°C, and the glass transition temperature (Tg) measured by a differential scanning calorimeter (DSC) is in the range of 25°C to 130°C.

[0033] Such component (A) is a polyorganosiloxane resin having a siloxane unit represented by 3 / 2 (wherein, in the formula, R is an alkyl group having 1 to 20 carbon atoms optionally substituted by a halogen atom or an aryl group having 6 to 14 carbon atoms) (hereinafter referred to as T unit) and SiO 4 / 2 The siloxane unit shown

[0034] (hereinafter referred to as Q unit), has at least one condensation-reactive functional group in the molecule, and has at least one aromatic functional group in the molecule.

[0035] The component (A) of the present invention may and preferably further has (R2SiO 2 / 2)n (hereinafter referred to as (D)n unit, wherein R is an alkyl group having 1 to 20 carbon atoms optionally substituted by a halogen atom or an aryl group having 6 to 14 carbon atoms, and n is a number in the range of 3 to 1000) of a polyorganosiloxane resin having a polydiorganosiloxane structure.

[0036] The condensation-reactive functional group in the component (A) is preferably a hydroxyl group or an alkoxy group having 1 to 3 carbon atoms, particularly preferably a hydroxyl group, and particularly preferably has a hydroxyl group in the range of 0.1% by mass to 2.0% by mass in the molecule. In addition, the aromatic functional group in the component (A) is a functional group that imparts thermoplasticity to the component (A), and can be an aryl group having 6 to 14 carbon atoms. Particularly preferably, it has a phenyl group on the T unit or the following (D)n unit, and particularly preferably contains an amount of phenyl groups that imparts the above-mentioned thermoplasticity.

[0037] Among them, the alkyl group having 1 to 20 carbon atoms or the aryl group having 6 to 14 carbon atoms as R is an alkyl group such as methyl and ethyl; an aryl group such as phenyl and tolyl; and a group in which a part or all of the hydrogen atoms bonded to these groups are substituted by a halogen atom such as a fluorine atom. From the viewpoint of industrial production, methyl or phenyl is preferred.

[0038] Preferably, the component (A) is a resin-linear polyorganosiloxane block copolymer having the following structure and having R A SiO 3 / 2 units, and the structure is a resin structure block composed only of R A SiO 3 / 2 (R A is a monovalent organic group, a hydroxyl group or an alkoxy group having 1 to 3 carbon atoms, and among all R A in the molecule, at least one or more are aryl groups having 6 to 14 carbon atoms); or optionally further has a Q unit: SiO 4 / 2 The resin structure block of the siloxane unit shown and (R 2 SiO 2 / 2 )n (wherein, n is the same number as described above, and R is the same group as described above) of the (D)n linear structure block are linked by a silakylene bond or a Si-O-Si bond. Preferably, in the silakylene bond or Si-O-Si bond that links the resin structure block and the linear structure block in the polymer, the Si atom bonded to the resin structure forms an R A SiO 3 / 2 unit.

[0039] The resin structure block in the component (A) is a partial structure that imparts thermoplasticity to the whole of the component (A), and is a resinous polyorganosiloxane structure. The structure is based on R A SiO 3 / 2The arylsiloxane unit shown is necessary to form a partial structure of a resinous polyorganosiloxane formed by bonding many T units or Q units. In particular, when many aryl groups such as phenyl groups are included in the molecule, the refractive index of component (A) can be increased. Preferably, component (A) is R containing 20% by mass to 100% by mass of the entire polyorganosiloxane A SiO 3 / 2 (wherein R A is the same group as described above) a polyorganosiloxane resin having an arylsiloxane unit, from the viewpoints of the above-mentioned hot melt property and refractive index, particularly preferably, the resin structure is substantially composed only of R A SiO 3 / 2 shown arylsiloxane units are formed.

[0040] The linear structure is a block represented by (R2SiO 2 / 2 )n, and is a structure in which at least three units or more, preferably five units or more of the diorganosiloxaneoxy units represented by R2SiO 2 / 2 are linked in a chain. The linear structure block is an arbitrary partial structure that imparts moderate softness to the solid layer formed of the polyorganosiloxane resin. In the formula, n is the degree of polymerization of the diorganosiloxaneoxy unit constituting the partial structure, preferably in the range of 3 to 250, more preferably in the range of 5 to 250, 50 to 250, 100 to 250, 200 to 250. If n in the partial structure exceeds the above upper limit, the properties of the linear molecule derived from the linear structure are strongly manifested, and sometimes the hot melt property becomes insufficient.

[0041] The resin structure block and the linear structure block in component (A) can be linked by the following bonds: a silakylene bond derived from a hydrosilylation reaction between an alkenyl group and a hydrogen atom bonded to a silicon atom, or a Si-O-Si bond derived from a condensable reaction group at the end of the resin structure or the linear structure. In particular, in the present invention, it is particularly preferred that the Si atom bonded to the resin structure constitutes R 1 SiO 3 / 2 unit, and particularly preferably has the following partial structure (T-Dn). From an industrial viewpoint, at least a part of R 1 is preferably phenyl, and R is preferably methyl or phenyl.

[0042] Partial structure (T-Dn)

[0043] [Chemical formula 1]

[0044]

[0045] Preferably, in the above partial structure, the ends of the Si—O—bonds on the left side constituting the T unit are each bonded to a hydrogen atom or another siloxane unit constituting the resin structure, preferably bonded to another T unit. On the other hand, the ends of the Si—O—bonds on the right side are bonded to other siloxane units forming a linear structure or a resin structure, a triorganosilyloxy unit (M unit), or a hydrogen atom. It goes without saying that when a hydrogen atom is bonded to the end of the Si—O—bond, a silanol group (Si—OH) is formed.

[0046] From the viewpoints of the hot melt property and the condensation reactivity of the component (A), the component (A) is particularly preferably the following siloxane unit formula:

[0047] {Si(Me)2O 2 / 2}a{Si(Me)(Ph)O 2 / 2}b{Si(Ph)2O 2 / 2}c{Si(Me)O 3 / 2}d{Si(Ph)O 3 / 2}e(OH)f where Me is a methyl group, Ph is a phenyl group, a + b + c + d + e is 1.0, a to e are each a number optionally being 0, a + b + c is a number in the range of 0 to 0.5, preferably a number in the range of 0 to 0.4, d + e is a number in the range of 0.5 to 1.0, preferably a number in the range of 0.6 to 1.0, b + c + e is a positive number, preferably, e is a number in the range of 0.3 to 1.0, and f is a number in the range where the content of the hydroxyl group in the polyorganosiloxane resin represented by the above formula is 0.1% by mass to 2.0% by mass, preferably a number in the range of 0.1% by mass to 1.0% by mass. It should be noted that when a + b + c + d = 0, the component (A) is a phenyl-containing T resin composed only of Si(Ph)O 3 / 2 and hydroxyl groups.

[0048] [Component (B)]

[0049] (B) component is one of the characteristic components of the present invention, and is a mixture containing a condensation reaction catalyst prepared by premixing the following (B1) and (B2) in a mass ratio of 1:99 to 90:10, where (B1) is a condensation reaction catalyst that is liquid at 25°C, and (B2) is a linear or cyclic polyorganosiloxane that is liquid at 25°C and has a siloxane polymerization degree in the range of 3 to 50.

[0050] [Technical significance of using the premixed mixture]

[0051] In order to uniformly mix component (A), which is non-fluid and capable of undergoing a condensation reaction by heating, and a condensation reaction catalyst at room temperature (25°C) substantially without using an organic solvent, the condensation reaction catalyst needs to be in a liquid state. Further, from the viewpoints of reaction controllability and suppression of side reactions, it is particularly preferable to add such a condensation catalyst in as small an amount as possible and to be able to remove it from the cured product by volatilization or the like upon heating during the curing reaction.

[0052] It is preferable to use a superbase catalyst such as 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) proposed in Patent Document 3 or the like as the condensation reaction catalyst that satisfies such conditions. However, for these superbase catalysts, especially the diazabicyclic compounds represented by DBU and the guanidine compounds represented by tetramethylguanidine (TMG), if not used in a large amount, the melt curability may sometimes be impaired. In particular, in a system containing solid particles such as functional fillers, a large amount of addition exceeding 3000 ppm with respect to the solid components of the composition is required. If a large amount of a condensation reaction catalyst is added to a hot-melt curable organosilicon composition, before curing, there is a possibility that the condensation-reactive polyorganosiloxane resin polymerizes due to side reactions, impairing the hot meltability and melt curability. In addition to this, it is very likely that even by heating during curing or the like, the condensation reaction catalyst is not sufficiently deactivated or removed, and unintended condensation reactions and reverse reactions occur after the curing reaction, reducing the physical properties of the cured product.

[0053] The inventors of the present case confirmed by methods such as nuclear magnetic resonance (NMR) that, with respect to the behavior of such superbase catalysts, the surface interaction between the superbase catalysts (such as DBU) and the solid phase (solid polyorganosiloxane resin, solid particles, functional fillers such as pigments, etc.) causes curing inhibition. In order to suppress the above-mentioned curing inhibition, pretreatment of functional fillers or the like with an organic solvent can be considered, but the object of the present invention of being solvent-free cannot be achieved, and the effect is also limited (see Comparative Example 2 described later).

[0054] The inventors of the present case found that: by pre-dispersing a superbase catalyst (such as DBU) in a liquid polyorganosiloxane with a low degree of polymerization and using it in the form of a pre-mixture, the interaction between the superbase catalyst and the solid phase can be suppressed. Even with a small addition amount, the melt-curing property is not impaired, and a system containing component (A) and optionally solid particles as component (C) can be cured at high speed. The mechanism is presumably as follows: the superbase catalyst (such as DBU) is stabilized with respect to the low-degree-of-polymerization polyorganosiloxane in the form of coordination or intermolecular interaction, and it is further stabilized by coordination with the solid organosilicon of component (A), suppressing the curing hindrance caused by the interaction with the solid particles (C). In particular, as shown in the following examples, etc., in the case of containing a solid phase such as a functional filler, compared with the case of separately adding the above-mentioned superbase catalyst (such as DBU), by using the pre-mixture, even if a small amount of condensation catalyst of 1 / 5 or less is used, the melt-curing property of the thermoplastic curable silicone composition is not impaired. Therefore, when its cured product is used for electronic components, heat dissipation materials, semiconductor components, optoelectronic semiconductor components, optical materials, etc., it is extremely useful. It should be noted that by optimizing the amounts and composition of component (B1) and component (B2) as a whole, the amount of the condensation reaction catalyst used can also be set to 1 / 15 or less, 1 / 20 or less of that in the case of separate addition.

[0055] [Component (B1)]

[0056] Component (B1) is a condensation reaction catalyst that is liquid at 25°C. For example, it can be exemplified by components selected from organic superbases, organometallic superbases, and inorganic superbases exemplified as "superbase catalysts" (=Super base) in Patent Document 1. In particular, from the aspect of being easily removable from the system by heating, etc. after the curing reaction, it is preferable to use a volatile organic superbase as the condensation reaction catalyst. It should be noted that being liquid at 25°C means that the condensation reaction catalyst itself has fluidity and can be uniformly dispersed in the solid phase without using an organic solvent by mechanical force.

[0057] In the present invention, preferred component (B1) is a diazabicyclic compound selected from diazabicycloundecene (DBU), diazabicyclononane (DBN), and diazabicyclooctane (DABCO); a guanidine compound selected from tetramethylguanidine (TMG), triazabicyclodecene (TBD), and N-methyltriazabicyclodecene (MTBD). These condensation reaction catalysts can be used alone or in combination. Considering the operability of industrial production, the properties of being liquid and volatile, etc., it is particularly preferable to use DBU.

[0058] [Component (B2)]

[0059] (Component (B2)) is a linear or cyclic polyorganosiloxane that is liquid at 25°C and has a degree of polymerization of siloxane in the range of 3 to 50. It is a component that can reduce the interaction between component (B1) and the solid phase (mainly solid particles and solid polyorganosiloxane resin) by coordinating or interacting with the above-mentioned component (B1), and can evenly disperse component (B1) in the solid phase by mechanical force. If only the dispersibility of component (B1) in the composition is improved, it can also be replaced with an organic solvent such as toluene. However, different from the prior mixture with low-polymerization polyorganosiloxane, the interaction between component (B1) and the solid phase cannot be sufficiently inhibited in the organic solvent, and the technical effect of the present invention cannot be achieved.

[0060] (B2) component is different from (B1) component and is preferably of low volatility or non-volatile. The reason is that (B2) component is a component that coordinates or interacts with (B1) component. Therefore, if it has high volatility, (B2) component volatilizes from the system, and (B1) component becomes in a "naked" state, and sometimes the technical effect of the present invention cannot be achieved.

[0061] The polyorganosiloxane in (B2) component is preferably a polyorganosiloxane having a monovalent hydrocarbon group, a silicon atom bonded to a hydrogen atom, an alkoxy group, and a silanol group, and preferably has an alkyl group, an aryl group, an alkenyl group, an aralkyl group, a (meth)acryloyloxy group, a haloalkyl group, an alkoxy group, a silanol group, a hydrogen atom, etc. bonded to the silicon atom constituting the polysiloxane.

[0062] Regarding such (B2) component, more specifically, the following can be exemplified:

[0063] Structural formula: (SiR 2 2O) k1

[0064] (In the formula, each R 2 is independently an alkyl group, an aryl group, or a silanol (OH) group, and k1 is a number in the range of 3 to 50)

[0065] The cyclic polyorganosiloxane shown;

[0066] Structural formula:

[0067] R 3 3SiO(SiR 3 2O) k2 SiR 3 3

[0068] (In the formula, each R 3 is independently an alkyl group, an aryl group, or a silanol (OH) group, and k2 is a number in the range of 1 to 48)

[0069] The linear polydiorganosiloxane shown; and

[0070] A branched polyorganosiloxane having a small number of branched units (T units or Q units) and a degree of polymerization of the siloxane in the range of 3 to 50.

[0071] From the viewpoints of industrial availability, non-volatility, affinity with the component (A), and the technical effects of the invention, preferred examples of the component (B2) include: cyclic phenylmethylsiloxanes with an average degree of polymerization of the siloxane of 3 to 20, cyclic (phenylmethylsiloxane)(dimethylsiloxane) copolymers, cyclic diphenylsiloxanes, and a polyphenylmethylsiloxane having a dimethylsilanol group silanyloxy terminal represented by the structural formula: HO-(SiPhMe-O) k3 -H (wherein k3 is a number in the range of 4 to 45), and a polydimethylsiloxane having a dimethylsilanol group silanyloxy terminal represented by the structural formula: HO-(SiMe2-O) k3 -H. It should be noted that they can be used alone or in combination of two or more.

[0072] [Mixing ratio and pre-mixing method]

[0073] In the component (B), the pre-mixing ratio of the above-mentioned component (B1) and component (B2) is in the range of a mass ratio of 1:99 to 90:10, and more preferably in the range of a mass ratio of 1:99 to 85:15. If the amount of the component (B1) is too small, the condensation reaction catalyst becomes a too low concentration, and sometimes the curing reactivity and curing rate decrease. If the amount of the component (B2) is too small, the interaction with the component (B1) becomes insufficient, and sometimes the melt-curing property of the whole composition is impaired. It should be noted that both are liquid at 25 degrees, and it is preferable to use a well-known mixing unit such as a mixer to mix them uniformly. If the mixing method is such that other components of the present invention, especially the (C) solid particles, come into contact with the component (B1) first, sometimes the technical effects of the present invention cannot be fully achieved even if the component (B2) is mixed later.

[0074] In the present invention, the amount of the component (B) used is not particularly limited. The content of the condensation reaction catalyst as the component (B1) is preferably 1000 ppm or less relative to the whole composition (solid components). For example, by using the above-mentioned pre-mixture as the component (B), good melt-curing properties can be achieved even when the content of the condensation reaction catalyst in the composition is in the range of 50 ppm to 1000 ppm, preferably in the range of 100 ppm to 1000 ppm.

[0075] [Component (C)]

[0076] (C) is a solid particle and is an arbitrary component of the present invention. In particular, it is added for the purpose of imparting mechanical properties and other properties to the cured product. Examples thereof include: inorganic fillers, organic fillers, and mixtures thereof. As described above, by using the component (B), the curable silicone composition of the present invention can achieve good melt curability with only a small amount of condensation reaction catalyst even when a large amount of the component (C) is contained.

[0077] There are no particular limitations on the type, function, shape, and particle size of the component (C). As inorganic fillers, examples include: reinforcing fillers, white pigments, heat conductive fillers, conductive fillers, phosphors, and mixtures of at least two of them. As organic fillers, examples include: silicone resin-based fillers, fluororesin-based fillers, polybutadiene resin-based fillers. It should be noted that the shape of these fillers is not particularly limited and can be spherical, spindle-shaped, flat, needle-shaped (fibrous), amorphous, etc.

[0078] In the present invention, it is preferable that at least a part of the component (C) is one or more selected from (CS) spherical solid particles, (CF) fibrous solid particles, and (CP) pigment or phosphor particles. In particular, from the viewpoint of improving the mechanical strength of the cured product, it is preferable that at least a part of the component (C) is (CS) spherical solid particles.

[0079] In addition to improving the mechanical strength of the cured product and improving protection and adhesiveness, the reinforcing filler can also be added as an adhesive filler for the curable silicone composition before curing for the purpose of maintaining the solid particle state. Examples of such reinforcing fillers include: fumed silica, precipitated silica, fused silica, calcined silica, fumed titanium dioxide, quartz, calcium carbonate, diatomaceous earth, alumina, aluminum hydroxide, zinc oxide, zinc carbonate. In addition, these reinforcing fillers can be surface-treated with organoalkoxysilanes such as methyltrimethoxysilane; organohalosilanes such as trimethylchlorosilane; organosilazanes such as hexamethyldisilazane; siloxane oligomers such as α,ω-silanol group-terminated dimethylsiloxane oligomer, α,ω-silanol group-terminated methylphenylsiloxane oligomer, α,ω-silanol group-terminated methylvinylsiloxane oligomer, etc. The particle size of this reinforcing filler is not limited, and the median particle size based on laser diffraction scattering type particle size distribution measurement is preferably in the range of 1 nm to 500 μm. Moreover, as the reinforcing filler, fibrous fillers such as calcium metasilicate, potassium titanate, magnesium sulfate, sepiolite, xonolite, aluminum borate, asbestos, and glass fiber can also be used.

[0080] Furthermore, for the purpose of imparting other functions to the cured product obtained by using this composition, color materials, white pigments, heat-conductive fillers, electrically conductive fillers, or phosphors may also be incorporated. In addition, for the purpose of improving the stress relaxation characteristics, etc. of the cured product, organic fillers such as silicone fine particles may also be incorporated.

[0081] Color materials (also referred to as pigments) are components that color the cured product and achieve light-shielding properties, etc. in the case of black. The components that can be used as colorants are not particularly limited, and organic dyes, carbon blacks such as furnace black and acetylene black, iron oxide (iron oxide red), etc. can be used, without particular limitation.

[0082] White pigments are components that impart whiteness to the cured product and improve light reflectivity, and the cured product obtained by curing this composition by incorporating the said components can be used as a light-reflecting material for light-emitting / optical devices. Examples of such white pigments include: metal oxides such as titanium oxide, aluminum oxide, zinc oxide, zirconium oxide, and magnesium oxide; hollow fillers such as glass spheres and glass beads; and barium sulfate, zinc sulfate, barium titanate, aluminum nitride, boron nitride, and antimony oxide. From the viewpoint of high light reflectivity and covering power, titanium oxide is preferred. In addition, from the viewpoint of high light reflectivity in the UV region, aluminum oxide, zinc oxide, and barium titanate are preferred. The average particle size and shape of this white pigment are not limited, and it is preferred that the average particle size is in the range of 0.05 μm to 10.0 μm or in the range of 0.1 μm to 5.0 μm. In addition, the surface of this white pigment can also be treated with a silane coupling agent, silica, aluminum oxide, etc.

[0083] Heat-conductive fillers or electrically conductive fillers are added for the purpose of imparting heat conductivity / electrical conduction to the cured product. Specifically, examples include: metal fine powders such as gold, silver, nickel, copper, and aluminum; fine powders obtained by vapor-depositing or plating metals such as gold, silver, nickel, and copper on the surfaces of fine powders of ceramics, glass, quartz, organic resins, etc.; metal compounds such as aluminum oxide, magnesium oxide, aluminum nitride, boron nitride, and zinc oxide; graphite and mixtures of two or more of them. In the case where electrical insulation is required for this composition, metal oxide-based powders or metal nitride-based powders are preferred, and aluminum oxide powder, zinc oxide powder, or aluminum nitride powder is particularly preferred. These heat-conductive fillers or electrically conductive fillers can also be used in combination according to the requirements for heat conductivity / electrical conduction in terms of type, particle size, particle shape, etc.

[0084] When the cured product is used as a wavelength conversion material, the phosphor is a component incorporated for converting the emission wavelength from a light source (light semiconductor element). There is no particular limitation on such a phosphor, and examples thereof include yellow, red, green, and blue light-emitting phosphors composed of oxide-based phosphors, oxynitride-based phosphors, nitride-based phosphors, sulfide-based phosphors, oxysulfide-based phosphors, etc., which are widely used in light-emitting diodes (LEDs).

[0085] Examples of the silicone fine particles include non-reactive silicone resin fine particles and silicone elastomer fine particles. From the viewpoint of improving the flexibility or stress relaxation characteristics of the cured product, silicone elastomer fine particles are preferably exemplified.

[0086] For the purpose of stably incorporating the above-mentioned functional fillers in the present composition, etc., a specific surface treatment agent can be used in the range of 0.1% by mass to 2.0% by mass, 0.1% by mass to 1.0% by mass, or 0.2% by mass to 0.8% by mass based on the mass of the whole component (C) to perform filler surface treatment. Examples of these surface treatment agents can be, for example, methylhydrogenpolysiloxane, silicone resin, metal soap, silane coupling agent, fluorine compounds such as perfluoroalkylsilane and perfluoroalkyl phosphate salt, etc.

[0087] The content of (C) is not limited, and depending on the use purpose of the curable silicone composition of the present invention, it is sometimes preferably not incorporated substantially. On the other hand, from the viewpoints of improving the hardness and mechanical strength of the obtained cured product and imparting functionality such as phosphors, it is preferably in the range of 0 parts by mass to 2000 parts by mass, 0 parts by mass to 1500 parts by mass, or 0 parts by mass to 1000 parts by mass relative to 100 parts by mass of the above-mentioned component (A).

[0088] It should be noted that the component (C) can be a component having any particle size, but when it is desired to impart gap filling properties to the composition during hot melting (heating and melting), it is preferable to use a component having an average particle size of 50 μm or less. On the other hand, from the viewpoint of imparting functionality, when it is desired to increase the addition amount of the component (C) as much as possible, in order to improve the encapsulation of the filler, it is preferable to combine components having different particle sizes.

[0089] [Other additives]

[0090] In addition to adding the above components to the curable silicone composition of the present invention, materials known in the art can also be added as additives optionally used in the silicone composition. Examples of the additives that can be used include, but are not limited to, the following additives.

[0091] In the composition of the present invention, an adhesion promoter may also be contained as long as the object of the present invention is not impaired. Such an adhesion promoter is the same as the components preferably exemplified by the applicant of the present case in the international patent application (PCT / JP2020 / 12027). In addition to silane compounds such as 3-glycidoxypropyltrimethoxysilane, organosiloxane oligomers, and alkyl silicates, a reaction mixture of an amino group-containing organoalkoxysilane and an epoxy group-containing organoalkoxysilane disclosed in Japanese Patent Publication No. 52-8854 and Japanese Unexamined Patent Publication No. 10-195085 can be preferably used. In particular, a cyclocarbonazanosiloxane derivative having a silicon atom-bonded alkoxy group or a silicon atom-bonded alkenyl group in one molecule, a silatrane derivative having an organo group containing an alkoxysilyl group, etc. They can be used as one component or in combination of two or more components. Sometimes, by using two or three components in combination, the adhesiveness and the like can be significantly improved.

[0092] Moreover, in the present composition, in order to simultaneously impart melt fluidity and ring-opening polymerizability, a cyclic trisiloxane such as cyclic 1,1,3,3,5,5-hexamethyltrisiloxane, cyclic 1,3,5-triphenyl-1,3,5-trimethyltrisiloxane, cyclic 1,1,3,3,5,5-hexaphenyltrisiloxane, etc., which is the same as the above-mentioned component B2, may be further added.

[0093] Moreover, in the present composition, as long as the object of the present invention is not impaired, heat-resistant agents such as cerium oxide, cerium dimethylsilanol, cerium fatty acid salt, cerium hydroxide, and zirconium compounds may be contained; in addition, dyes, pigments other than white, flame retardant agents, etc. may be contained as other optional components.

[0094] On the other hand, since the composition of the present invention is a composition intended to be free of organic solvents, it is preferably substantially free of organic solvents such as acetone, toluene, and xylene. Specifically, in the curable organosilicon composition of the present invention, including the organic solvents derived from raw materials such as component A), the content of the organic solvents is less than 5% by mass of the whole composition, particularly preferably less than 1% by mass, and particularly preferably less than 0.1% by mass. In addition, with respect to the composition of the present invention, it is preferable that substantially only component (B1) cures, and the reacted component (B1) does not participate in side reactions or is removed from the cured product by volatilization or the like. Therefore, with respect to the composition of the present invention, the content of the curing catalyst and the crosslinking agent other than the above-mentioned (B1) is preferably less than 1% by mass of the whole composition, particularly preferably less than 0.1% by mass, and particularly preferably other curing catalysts and crosslinking agents are not added intentionally.

[0095] The curable silicone composition of the present invention can be made into a granular composition by powder-mixing the component (A), the component (B), and any other optional components at a temperature lower than the softening point of the component (A). The powder mixer and crusher used in this manufacturing method are not limited, and examples thereof include single-screw or twin-screw continuous mixers, double-roll mixers, Ross mixers, Hobart mixers, dental mixers, planetary mixers, kneaders, choppers, Free Speed Mills, Labo Mills, small crushers, and Henschel mixers. Preferred are Labo Mills, small crushers, and Henschel mixers.

[0096] The curable silicone composition of the present invention can obtain any molded form of granular, particulate, or sheet-like through its manufacturing process. When used in particulate form, it can be efficiently produced by tableting the granular composition. It should be noted that "particles" are sometimes also referred to as "tablets". The shape of the particles is not limited, and is usually spherical, ellipsoidal, or cylindrical. In addition, the size of the particles is not limited. For example, it has an average particle diameter or equivalent circle diameter of 500 μm or more.

[0097] This composition can also be molded into a sheet for use. For example, a sheet formed from a curable silicone composition with an average thickness of 100 μm to 1000 μm has hot melt properties and heat-curing properties at high temperatures. Therefore, especially in the case of being used for compression molding, etc., it is advantageous in terms of excellent operation workability and melting characteristics. Such a sheet-like composition can be produced as follows: After integrating the curable granular composition obtained by the above method at a low temperature using a single-screw or twin-screw continuous kneader, it is made into a specified thickness by two rolls or the like.

[0098] This composition has hot melt properties, so it can be heated and melted using a twin-screw extruder or the like and filled into a cartridge for a dispensing machine for use. It should be noted that a hot melt curable silicone composition product (DOWSIL TM EA-4600 silicone adhesive) can also be used in a hot dispensing method in which it is discharged using a heated dispensing machine.

[0099] From the viewpoints of transportation and the like, the molded curable silicone composition can be supported between substrates having a release layer and used as a release laminate. For example, in the case of a curable phosphor sheet formed from a curable silicone composition, it can be made into a form that is laminated between plastic films having a release layer (for example, a release film formed from a PET film or the like) and can be arbitrarily cut, and the release film is peeled off for use when in use.

[0100] The curable silicone composition of the present invention can preferably be obtained by a production method including the following steps 1 to 3. Here, preferably, in any of the following steps 1 to 3, it is a dry process in which an organic solvent is substantially not used.

[0101] Step 1: A step of mixing the component (B1) and the component (B2) to obtain a mixture containing a condensation reaction catalyst;

[0102] Step 2: A step of mixing the component (A) and any other component with the mixture containing a condensation reaction catalyst obtained in Step 1 using mechanical force to obtain a curable silicone composition; and

[0103] Step 3: A step of molding the curable silicone composition obtained in Step 2.

[0104] The conditions for curing the curable silicone composition of the present invention are not particularly limited. Particularly preferably, it is cured by a method including at least the following steps (I) to (III) accompanied by molding.

[0105] Step (I): Heating the present composition to 100°C or higher to melt it;

[0106] Step (II): Injecting the curable silicone composition obtained in Step (I) into a mold, or causing the curable silicone composition obtained in Step (I) to cover the mold by closing the mold; and

[0107] Step (III): Curing the curable silicone composition injected in Step (II).

[0108] The curing conditions of the curable silicone composition of the present invention are not particularly limited. Preferably, it is heated in the range of room temperature to 200°C, preferably in the range of 80°C to 170°C. It should be noted that the condensation reaction catalyst as (B1) is activated at the time of heating and melting, so after heating and melting, a curing reaction can also be carried out by any method after molding to form a cured product.

[0109] [Use of the composition]

[0110] The present composition has hot melt properties, and has excellent fluidity, workability, and curability during melting (hot melting). Therefore, it is preferably used as a sealant and underfill for semiconductors; a sealant and underfill for power semiconductors such as SiC and GaN; a sealant and light reflection material for optoelectronic semiconductors such as light-emitting diodes, photodiodes, phototransistors, and laser diodes; an adhesive, potting agent, protective agent, and coating agent for electrical / electronic use. Moreover, a sheet obtained by forming the present composition into a sheet can also be used as a curable phosphor sheet, film adhesive, and stress buffer layer between two substrates having different coefficients of linear expansion.

[0111] In addition, the present composition has hot melt properties, and thus is also preferably used as a material for transfer molding, compression molding, or injection molding, and can also be used as a sealant for semiconductors using the molded underfill method or wafer molding method during molding. In particular, the curable silicone composition of the present invention can be preferably used for the purpose of obtaining a cured product by transfer molding.

[0112] [Cured Product and Laminate Containing the Cured Product]

[0113] The cured product obtained by curing the curable silicone composition of the present invention is preferably used as a member for electronic components, semiconductor devices, or optoelectronic devices. The curable silicone composition of the present invention can form a cured product with a desired shape on a substrate by transfer molding or the like, and thus a laminate having the cured product of the present invention is useful as an electronic component, semiconductor device, optoelectronic device, or a member thereof. As described above, preferably, the curable silicone composition of the present invention is configured as a molded product in the form of an ingot, granule, sheet, or film and used as a member for electronic components, semiconductor devices, or optoelectronic devices by curing or molding.

[0114] The use of the cured product obtained by curing the curable silicone composition of the present invention is not particularly limited, and it can be preferably used as a member for electronic components, semiconductor devices, or optoelectronic devices, and can be preferably used as a sealing material for semiconductor elements, IC chips, etc.; an adhesive / bonding member / sealant for semiconductor devices, and is particularly suitable for applications requiring high heat resistance and light resistance.

[0115] There is no particular limitation on the semiconductor device having a structure including a cured product obtained by curing the curable silicone composition of the present invention. For example, preferably, a light-emitting semiconductor device as a light-emitting / optical device, an optical member for display, or a member for a solar panel, and particularly a sealing material, a housing material, or a bonding member for these devices. Moreover, the cured product of the present invention has excellent coloring resistance at high temperatures, and thus can be more preferably used as a sealing material, a housing material, or a bonding member in electronic materials where transparency and light / heat resistance become important.

[0116] Examples

[0117] The curable silicone composition of the present invention and its manufacturing method will be described in detail below through examples and comparative examples. It should be noted that in the following description, Me, Vi, and Ph in chemical formulas represent methyl, vinyl, and phenyl, respectively. In addition, for the curable silicone compositions of each example and comparative example, the forming of ingots and the production of cured sheet samples were carried out using the methods shown below. In addition, the following methods were used to measure its melt curability (flow curability), formability, and the reflectivity of light related to the cured sheet / wavelength conversion achieved by the phosphor sheet / light diffusibility / light transmittance. It should be noted that the measurement results are shown in Table 2 and below.

[0118] [Forming of ingots]

[0119] With the components and mixing conditions shown in each example / comparative example (Table 2 and below), pulverization and stirring were carried out using a mixer (manufactured by Osaka Chemical Co., Ltd., trade name Labo Mill (disposable container PN-M21): rotation speed 20,000 rpm), and the curable silicone composition was adjusted in the form of a powder (= solid) mixture. Each of the obtained compositions (powder mixture) was formed into an ingot shape with a length of 1 mm - 32 mm and a diameter of 3 mm - 16 mm using an ingot molding machine (manufactured by Ichihashi Seiki Co., Ltd., trade name HAND TAB).

[0120] [Production of cured sheet samples]

[0121] The ingots of each example / comparative example were pressure-pressed at 130 °C for 15 minutes in a mold box of the required thickness, and then cured in an oven at 150 °C for 1 hour to produce sheet-like cured samples.

[0122] [Measurement of Shore D hardness]

[0123] The measurement was carried out using an automatic rubber hardness meter P2 manufactured by Kobunshi Keiki Co., Ltd.

[0124] [Measurement of density]

[0125] The measurement was carried out using an XP-105 analytical balance and a density measurement component manufactured by METTLER TOLEDO.

[0126] [Measurement of glass transition temperature]

[0127] The measurement was carried out using DSC2500, a thermal analysis system of TA Instrument.

[0128] [Measurement of linear expansion coefficient]

[0129] The measurement was carried out using the TMA7100 of Hitachi High-Tech Science Corporation as a thermomechanical analysis device. The linear expansion coefficient at temperatures below the glass transition temperature is represented by α1 (ppm), and the linear expansion coefficient at temperatures above the glass transition temperature is represented by α2 (ppm).

[0130] [Melt curability (flow curability)]

[0131] The measurement was carried out using the Premier MDR of Alpha Technologies Corporation as a Moving Die Rheometer (MDR) according to the methods based on ASTM D5289 and ISO 6502.

[0132] At a frequency of 100 cycles per minute (1.66 Hz), a vibration angle of + / - 0.5 degrees,

[0133] a measurement was carried out at 130 °C for 15 minutes.

[0134] The minimum torque value ML is 1 dNm or less, and the time (TS1 value) when the torque value rises by 1 dNm from the minimum torque value is 180 seconds or less. Regarding the melt curability, when a cured product is obtained, it is evaluated as "good", and otherwise it is evaluated as "poor curing" or "curing delay". In addition, the maximum torque value (MH) is recorded, and the time when it becomes 50% of the torque value is recorded as T50 (seconds).

[0135] [Moldability]

[0136] Using the G-CUBE (MPC-06M) manufactured by APIC YAMADA, the mold base temperature was set so that the resin temperature became 130 °C. For the lead frame (TD-3535-01-1) of APIC YAMADA with a size of 57 mm W, 50 mm D, and 0.25 mm T, 4 g of resin with a diameter of 13 mm was used, and transfer molding was carried out using a pattern with two resin heights of 50 mm W, 47 mm D, and heights of 0.45 mm and 0.40 mm (130 °C for 5 minutes after clamping). A substance with good adhesion to the substrate without peeling and capable of molding into a mold shape was judged to have good moldability.

[0137] [Complex viscosity at 130 °C]

[0138] Using the rheometer MCR301 manufactured by Anton Paar, for the thin disk tablets made with a diameter of 10 mm and a height of 1 mm, a parallel plate with a diameter of 10 mm was used to measure the minimum value of the complex viscosity at a strain of 3% and an amplitude of 1 Hz.

[0139] [Light reflectance]

[0140] Using a spectrophotometer CM-5 manufactured by KONICA MINOLTA, Inc., the light reflectance of the produced cured product sheet was measured.

[0141] [Wavelength conversion achieved by the phosphor sheet]

[0142] Regarding the cured product sheet containing a phosphor, using a fluorescence film inspection system DF-500A manufactured by Otsuka Electronics Co., Ltd., blue LED light with a wavelength of 447 nm was irradiated, and the chromaticity coordinates (x, y) and relative color temperature (K) obtained by wavelength conversion achieved by the cured product sheet were measured.

[0143] [Light diffusion characteristics]

[0144] The light diffusion characteristics of the cured product sheet were measured using a Genesia Gonio / Far Filed Profiler manufactured by Genesia Corporation. When using 45 degrees of the bidirectional transmittance distribution function and setting the transmitted light intensity of the light incident perpendicular to the measurement specimen surface, that is, the straight-through light intensity, to 1, if the received light intensity at a position where the light receiving unit is inclined 45 degrees relative to the incident light axis with the measurement specimen as the center is 0.65 or more, it is evaluated as a good light diffusion material and rated as "〇", and if the received light intensity of the specimen is less than 0.65, it is rated as poor and rated as "×".

[0145] [Transmittance]

[0146] The transmittance of the cured product sheet was measured using a V770 ultraviolet-visible-near-infrared spectrophotometer manufactured by JASCO Corporation equipped with an integrating sphere unit.

[0147] [(A) Solid polyorganosiloxane resin]

[0148] In the examples and comparative examples, as the solid polyorganosiloxane resin, resins A-a to A-d composed of the siloxane units (mol%) shown in Table 1 below and having the weight-average molecular weight (Mw), Tg (°C), and hydroxyl group content (mass%) shown in Table 1 below were used. It should be noted that D(Me)2, DMePh, D(Ph)2, T(Me), and T(Ph) in the table are Si(Me)2O 2 / 2 , Si(Me)(Ph)O 2 / 2 , Si(Ph)2O 2 / 2 , Si(Me)O 3 / 2 , Si(Ph)O 3 / 2 shown siloxane units. All of them are hot-melt polyorganosiloxane resins containing OH groups and phenyl groups.

[0149] [Table 1]

[0150]

[0151] [(B) Superbase catalyst / mixture for condensation reaction]

[0152] In the examples and comparative examples, the following catalyst B was used. Hereinafter, 1,8-diazabicyclo[5.4.0]undec-7-ene is referred to as "DBU". DBU is liquid and volatile at room temperature, and the % in () is the mass % of DBU in the mixture. In addition, catalysts B-c to B-h are premixed products corresponding to the component (B) in the present invention.

[0153] Catalyst B-a': DBU (100%).

[0154] Catalyst B-b': Toluene solution of DBU (10%).

[0155] Catalyst B-c: Mixture of DBU and cyclic phenylmethylsiloxane (average degree of polymerization 4) (1%).

[0156] Catalyst B-d: Mixture of DBU and polysiloxane represented by the average composition formula HO-(SiPhMe-O)5-H (73%).

[0157] Catalyst B-e: Mixture of DBU and polysiloxane represented by the average composition formula HO-(SiMe2-O) 12 -H (27%).

[0158] Catalyst B-f: Mixture of DBU and polysiloxane represented by the average composition formula HO-(SiMe2-O) 30 -SiMe3 (6%).

[0159] Catalyst B-g: Mixture of DBU and cyclic dimethylsiloxane (average degree of polymerization 4) (5%).

[0160] Catalyst B-h: Mixture of DBU and cyclic phenylmethylsiloxane (average degree of polymerization 4) (5%).

[0161] [(C) Solid particles]

[0162] In the examples and comparative examples, the following powders were used as solid particles. Note that the alphanumeric characters at the end of each component are product numbers.

[0163] Powder C-as: Spherical silica FB-5SDC with an average particle size of 4 μm manufactured by Denka Co., Ltd.

[0164] Powder C-bs: Spherical silica SE-15K with an average particle size of 16 μm, manufactured by Tokuyama Corporation.

[0165] Powder C-cs: Spherical silica SE-30K with an average particle size of 25 μm, manufactured by Tokuyama Corporation.

[0166] Powder C-ds: Spherical silica UF-725 with an average particle size of 7 μm, manufactured by Tokuyama Corporation.

[0167] Powder C-es: Spherical silica FB-7SDC with an average particle size of 6 μm, manufactured by Denka Co., Ltd.

[0168] Powder C-fs: Spherical silica ST-7010-2 with an average particle size of 10 μm, manufactured by Nippon Steel Sumikin Materials Co., Ltd.

[0169] Powder C-gs: Spherical silica ST-7011-3 with an average particle size of 12 μm, manufactured by Nippon Steel Sumikin Materials Co., Ltd.

[0170] Powder C-hf: Ground fiber EFDE50-01 with an average fiber length of 50 μm and a fiber diameter of 11 μm, manufactured by CENTRAL GLASS FIBER Co., Ltd.

[0171] Powder C-if: Amino-silane treated ground fiber EFDE50-31 with an average fiber length of 50 μm and a fiber diameter of 11 μm, manufactured by CENTRAL GLASS FIBER Co., Ltd.

[0172] Powder C-jf: Ground fiber EFDE75-01 with an average fiber length of 75 μm and a fiber diameter of 11 μm, manufactured by CENTRAL GLASS FIBER Co., Ltd.

[0173] Powder C-kf: Ground fiber EFDE90-01 with an average fiber length of 90 μm and a fiber diameter of 6 μm, manufactured by CENTRAL GLASS FIBER Co., Ltd.

[0174] Powder C-lp: Carbon black SUNBLACK235, manufactured by Asahi Carbon.

[0175] Powder C-mp: Titanium oxide SX-3103, manufactured by Sakai Chemical Industry Co., Ltd.

[0176] Powder C-np: YAG yellow phosphor NYAG4454S, manufactured by INTEMRTIX Corporation.

[0177] Powder C-os: Spherical silica FB-3SDC with an average particle size of 3 μm, manufactured by Denka Co., Ltd.

[0178] Powder C-ps: Spherical alumina AZ4-10 with an average particle size of 3 μm, manufactured by Nippon Steel Sumikin Materials Co., Ltd.

[0179] Powder C-qs: Spherical silica S4080-5 with an average particle size of 23 μm, manufactured by Nippon Steel Sumikin Materials Co., Ltd.

[0180] [Additives]

[0181] In the examples and comparative examples, for the purpose of the functions of tackifiers and the like, the following Additives 1 to 3 were used.

[0182] Additive 1: 3-Glycidoxypropyltrimethoxysilane.

[0183] Additive 2: A cyclosilazane derivative represented by the following structural formula.

[0184] [Chemical formula 2]

[0185]

[0186] Additive 3: 3-Glycidoxypropylmethyldiethoxysilane.

[0187] Additive 4: Cyclic 1,1,3,3,5,5-hexamethyltrisiloxane (D3).

[0188] [Comparative Examples 1 to 2, Examples 1 to 7]

[0189] According to the composition shown in Table 2 below, Resin A was added to a mixer, pulverized and stirred for 15 seconds and then cooled, and then this operation was repeated twice. Powder C and Catalyst B were put into the obtained powder, pulverized and stirred for 15 seconds and then cooled, and then this operation was repeated twice. Thus, a curable silicone composition was prepared in the form of a powder mixture. The composition was formed into a tablet shape, and the melt curability and the like were evaluated by the method described above. It should be noted that the DBU concentration in the composition is expressed in DBU (ppm).

[0190] [Table 2]

[0191]

[0192] *Curing is poor at the following DBU concentrations.

[0193] In the examples, cyclic phenylmethylsiloxane that does not volatilize at room temperature was used, whereby DBU

[0194] The catalyst was dispersed in the silicone. As in Example 1 and Example 2, even when the DBU content was 1 / 5 or less of that in Comparative Example 2, the melt curability was good. Moreover, in the composition containing Powder C, compared with Comparative Example 1, even when the addition of the catalyst was suppressed to about 1 / 15 (about 200 ppm) or less, the melt curability was good. Further, from the comparison between Example 3 and Example 4, it was found that in the composition containing Powder C, the hardness of the cured product increased significantly and the linear expansion coefficient decreased. Therefore, a composition of an epoxy-based molding compound suitable as a solid encapsulating material for semiconductors could be designed. It should be noted that the reason for being able to reduce the addition amount of DBU is considered to be that DBU forms a coordination bond with cyclic phenylmethylsiloxane by prior mixing, which hinders the adsorption of DBU to the surface of solids (powders) and the like.

[0195] In Comparative Example 1 and Comparative Example 2, good melt curability could barely be achieved by setting the DBU concentration to an extremely high addition amount (exceeding 1000 ppm), but the curing was poor at addition amounts below this, and sufficient melt curability could not be achieved. Moreover, since the DBU concentration was too high, there was a possibility of adversely affecting the hardness and stability of the cured product due to side reactions before and after curing.

[0196] [Examples 8 to 18]

[0197] The composition shown in Table 3 below was used, and otherwise, a curable silicone composition was prepared in the form of a powder mixture in the same manner as in Example 1. The composition was molded into an ingot shape, and the melt curability and the like were evaluated by the method described above. It should be noted that the DBU concentration in the composition is expressed in terms of DBU (ppm).

[0198] [Table 3]

[0199]

[0200] In each example, it was confirmed that by premixing DBU with various cyclic or chain siloxanes, good melt curability could be achieved even in a composition containing powders, even when the DBU concentration was 1000 ppm or less. It should be noted that it was found that the coordination ability to DBU differed depending on the type of siloxane, and thus the curing rate of each composition was different. Therefore, the desired curing rate could be designed by designing the type of siloxane premixed with DBU and the DBU concentration.

[0201] [Examples 19 to 26: Black light-shielding material]

[0202] Set to the composition shown in Table 4 below. Except for this, a curable silicone composition was prepared in the form of a powder mixture in the same manner as in Example 1. The composition was molded into an ingot shape, and the melt curability and the like were evaluated by the method described above. These compositions are designed to contain a resin, spherical powder, fibrous powder, and a black pigment (carbon black), and the cured product of the composition is a light-shielding material. It should be noted that the DBU concentration in the composition is expressed in DBU (ppm).

[0203] [Table 4]

[0204]

[0205] In each of the examples, even for compositions containing spherical powder, fibrous powder, and a black pigment, a hot-melt composition having good melt curability at a DBU concentration of 200 ppm or less and providing a cured product with excellent curing speed, mechanical strength, moldability, and light-shielding property was obtained.

[0206] [Examples 27 and 28: Adhesion of black light-shielding material]

[0207] Set to the composition shown in Table 5 below. Except for this, a curable silicone composition was prepared in the form of a powder mixture in the same manner as in Example 1. The composition was molded into an ingot shape, and the melt curability and the like were evaluated by the method described above. These compositions are designed to contain a resin, spherical powder, fibrous powder, and a black pigment (carbon black), and the cured product of the composition is a light-shielding material. It should be noted that the DBU concentration in the composition is expressed in DBU (ppm).

[0208] [Table 5]

[0209]

[0210] In each of the examples, even for compositions containing spherical powder and a black pigment, a hot-melt composition having good melt curability at a DBU concentration of 200 ppm or less and providing a cured product with excellent curing speed, mechanical strength, moldability, and light-shielding property was obtained.

[0211] [Adhesion strength to glass]

[0212] Moreover, using the compositions of Example 27 and Example 28, the adhesion to untreated / primed surface-treated glass substrates before and after temperature tests was evaluated by the following method.

[0213] [Evaluation]

[0214] Between a 25×75×1.1 mm Corning Eagle XG glass plate and a 5×5×1.1 mm one, 0.1 g of the curable composition of Example 27 or Example 28 was sandwiched to form a diameter of 5 mm and a thickness of 0.13 mm, heated at 150°C for 1 hour to cure it, the portions protruding from the approximate shape were removed, and the chip shear strength was measured using a bond tester SS = 30WD manufactured by Seishin Shokai Co., Ltd.

[0215] The results using the following substrates are also shown. The substrate was obtained by immersing the above glass substrate in a solution obtained by diluting DOW TORAY's primer APZ-6601 (a solution mainly containing N-β-aminoethyl-γ-aminopropyltriethoxysilane) 20-fold, drying it, and treating it at 80°C for 1 hour (=primer treatment).

[0216] Moreover, each of these substrates was subjected to a two-week environmental resistance test at temperatures of -40°C and 85°C for 30 minutes each in an ESPEC refrigerated thermal shock testing machine TSA-73EH; and a two-week environmental resistance test at a temperature of 85°C and a humidity of 85% in an ESPEC constant temperature and humidity chamber PL-3J, and the results are shown in Table 6 below.

[0217] [Table 6]

[0218]

[0219] As shown in Table 6, the cured products obtained by curing the compositions of Example 27 and Example 28 have excellent initial adhesiveness to untreated glass / primer-treated glass, and also show very high adhesive reliability in impact tests and the like. In addition, it was confirmed that good adhesiveness is also shown even when used in combination with primer treatment.

[0220] [Examples 29, 30: Optical members]

[0221] The composition was set as shown in Table 7 below, and otherwise, a curable silicone composition was prepared in the form of a powder mixture in the same manner as in Example 1. The composition was molded into a tablet shape, and the melt curability and the like were evaluated by the method described above. Example 29 is a white light diffusing material containing titanium oxide (white pigment), and Example 30 is a phosphor sheet containing a yellow phosphor. As described below, even when the DBU concentration is 1000 ppm or less, it is a composition having good melt curability and providing a cured product with excellent curing speed, mechanical strength, moldability, and expected optical properties. Note that the DBU concentration in the composition is expressed in DBU (ppm).

[0222] [Table 7]

[0223]

[0224] In each embodiment, even a composition containing spherical powder, fibrous powder, white reflective material, and phosphor can obtain a hot-melt composition having good melt-curing properties at a DBU concentration of 1000 ppm or less, and can provide a cured product excellent in curing rate, mechanical strength, moldability, and light-shielding property. In Example 29, a cured product showing a high reflectance was obtained, and in Example 30, a warm-color white was obtained by efficiently converting blue LED using a phosphor.

[0225] [Examples 31 and 32: Light Diffusion Plate]

[0226] A curable silicone composition was prepared in the form of a powder mixture in the same manner as in Example 1, except that the composition shown in Table 8 below was used. The composition was molded into an ingot shape, and the melt-curing property and the like were evaluated by the above-described method. These compositions are designed as light-diffusing materials, but spherical alumina as Powder C-ps is also functional particles for heat dissipation / thermal conductivity. It should be noted that the DBU concentration in the composition is expressed in terms of DBU (ppm).

[0227] [Table 8]

[0228]

[0229] By using the preliminary mixture of the condensation catalyst of the present invention, even when the DBU concentration is 500 ppm or less, a composition having good melt-curing properties and providing a cured product excellent in curing rate, mechanical strength, moldability, and optical properties such as light transmittance and light diffusibility can be obtained.

[0230] [Summary]

[0231] By using a prior mixture of DBU and various liquid siloxanes as a condensation reaction catalyst and mixing it with a silicone having a glass transition temperature of 25 °C or higher, the interaction between DBU and powders, etc. can be hindered. Therefore, regardless of the type and presence or absence of functional powders, a thermoplastic curable silicone composition and its molded article (ingot) having good melt curability at a lower DBU concentration can be obtained, and a cured product excellent in curing rate, mechanical strength, transfer moldability, and physical functions achieved by functional fillers can be provided. This composition substantially does not require an organic solvent in terms of manufacturing and use, and is suitable for a solvent-free manufacturing process and use process. On the contrary, in the case where the prior mixture of the condensation reaction catalyst is not used, good melt curability cannot be achieved unless the concentration of DBU is too high. Even if it can be achieved, there may be side reactions such as unintended condensation of resins before and after the curing reaction, and deterioration of the cured product and reduction of functions over time may occur. It should be noted that in the present invention, the melt curability was evaluated and the rheological measurement was performed at 130 °C, but it goes without saying that the evaluation can also be performed at 170 °C.

[0232] The thermoplastic curable silicone composition of the present invention optionally contains or does not contain a functional filler. Even if it contains any one of spherical powders, fibrous powders, pigments (white pigments and black pigments), and heat-conductive fine particles, the effects of the invention can be achieved. Therefore, it can be used for the design of various functional members. For example, these compositions can be used for protective materials, sealants, adhesive materials (bonding members). In addition, they can also be used for light-shielding materials, white reflective materials, phosphor sheets, light-diffusing materials, heat dissipation / heat-conductive materials, conductive materials, etc.

Claims

1. A curable organosilicon composition, the curable organosilicon composition containing: (A) The glass transition temperature Tg is in the range of 25 °C to 130 °C, and the molecule contains RSiO 3 / 2 or SiO 4 / 2 A polyorganosiloxane resin having the siloxane units shown and having at least one condensation-reactive functional group and one aromatic functional group in the molecule. In the formula, R is an alkyl group having 1 to 20 carbon atoms optionally substituted by a halogen atom or an aryl group having 6 to 14 carbon atoms; (B) A mixture containing a condensation catalyst, which is prepared by premixing the following components (B1) and (B2) in a mass ratio of 1:99 to 90:10: (B1) A condensation catalyst that is liquid at 25°C, (B2) A linear or cyclic polyorganosiloxane that is liquid at 25°C and has a siloxane polymerization degree in the range of 3 to 50, The curable organosilicon composition is non-flowable at 25°C as a whole and has hot melt properties.

2. The curable organosilicon composition according to claim 1, wherein (B1) is a volatile condensation catalyst, and the content of the condensation catalyst is 1000 ppm or less relative to the whole composition.

3. The curable organosilicon composition according to claim 1 or 2, wherein (B1) is one or more condensation catalysts selected from diazabicycloundecene (DBU), diazabicyclononane (DBN), diazabicyclooctane (DABCO), tetramethylguanidine (TMG), triazabicyclodecene (TBD), and N-methyltriazabicyclodecene (MTBD).

4. The curable organosilicon composition according to claim 1, wherein The curable organosilicon composition further contains (C) solid particles.

5. The curable organosilicon composition according to claim 4, wherein At least a part of the component (C) is one or more selected from spherical solid particles, fibrous solid particles, and pigment or phosphor particles.

6. The curable organosilicon composition according to claim 1, wherein The content of the organic solvent is less than 5% by mass of the whole composition, and the content of the curing catalyst and crosslinking agent other than the component (B1) is less than 1% by mass of the whole composition.

7. The curable organosilicon composition according to claim 1, wherein The curable organosilicon composition is for transfer molding.

8. The curable organosilicon composition according to claim 1, wherein The complex melt viscosity of the whole composition at 130°C is 500000 Pa·s or less, and it is in the form of a molded article such as a tablet, granule, sheet, or film.

9. The curable organosilicon composition according to claim 1, wherein The complex melt viscosity of the whole composition at 130°C is 500000 Pa·s or less, and it has a form filled into a cartridge for a dispensing machine.

10. A cured product, which is obtained by curing the curable organosilicon composition according to any one of claims 1 to 9.

11. A peelable laminate, the peelable laminate comprising: A substrate having a peel layer; and a molded article of the curable organosilicon composition according to any one of claims 1 to 6.

12. A laminate having a cured product obtained by curing the curable organosilicon composition according to any one of claims 1 to 9.

13. The laminate according to claim 12, wherein the laminate is an electronic component or a member thereof.

14. A method for producing a curable organosilicon composition, which is a method for producing the curable organosilicon composition according to any one of claims 1 to 9, comprising: Step 1: a step of mixing component (B1) and component (B2) to obtain a mixture containing a condensation reaction catalyst; Step 2: a step of mixing component (A) and any other components with the mixture containing a condensation reaction catalyst obtained in Step 1 using mechanical force to obtain a curable organosilicon composition; and Step 3: a step of molding the curable organosilicon composition obtained in Step 2, and any of Steps 1 to 3 is a dry process that substantially does not use an organic solvent.

15. A method for producing a laminate, the method for producing a laminate comprising: a step of forming, by transfer molding, a cured product obtained by curing the curable organosilicon composition according to any one of claims 1 to 9 on a substrate.

Images