Curable hot melt silicone composition, cured product of said composition, and method for producing film or the like comprising said composition

Abstract

[Problem] To provide: a hot melt silicone composition that can be cured at a wide temperature range from low to high temperatures in accordance with a sealing process and the heat resistance of a resin member, can achieve suitable curability at room temperature or other low temperatures in particular, obtains a cured product having excellent transparency and yellowing resistance, and has excellent handling workability in overmolding and the like; and a use for the hot melt silicone composition. [Solution] Provided is a curable hot melt silicone composition containing: (A) a resin / linear structure–containing organopolysiloxane block copolymer having a chain organosiloxane block Y and a resinous organosiloxane block X that includes a Q unit and a triorganosiloxane unit (MRA unit) which has a silicon atom–bonded functional group (RA) including an acrylic group or a methacrylic group, the block copolymer having at least two of said silicon atom–bonded functional group (RA) per molecule; and (B) a radical polymerization initiator. Also provided is a use for the curable hot melt silicone composition.

Description

Curable hot-melt silicone composition, cured product of said composition, and method for producing film or the like made from said composition

[0001] The present invention relates to a curable hot-melt silicone composition and a technique for sealing optical components using said composition.

[0002] Curable silicone compositions are used in a wide range of industrial fields because they cure to form cured products that have excellent heat resistance, cold resistance, electrical insulation, weather resistance, water repellency, and transparency. Cured products of such curable silicone compositions are less susceptible to discoloration than other organic materials and experience only small deterioration in physical properties, making them suitable for use as optical materials and sealants for semiconductor devices.

[0003] The present patent applicants have disclosed heat-curable hot-melt silicone compositions in, for example, Patent Documents 1 and 2. Specifically, Patent Document 1 discloses a heat-curable composition containing a hot-melt silicone having hydrosilylation-reactive groups and / or radical-reactive groups, while Patent Document 2 discloses a reactive silicone composition that is hydrosilylation-curable, has alkenyl groups, and provides a reactive thermoplastic that becomes fluid at high temperatures. However, these documents do not specifically disclose hot-melt silicone compositions containing a resin-linear structure-containing organopolysiloxane block copolymer having a resinous organosiloxane block containing acrylic or methacrylic groups. Furthermore, the curing agents disclosed in Patent Documents 1 and 2 are hydrosilylation reaction catalysts or organic peroxides that undergo heat-curing reactions requiring high temperatures above 150°C, and no description or suggestion is made of low-temperature curing reactions or photocuring reactions.

[0004] On the other hand, in recent years, due to the demand for weight reduction and functionality, there has been an increasing demand for optical devices and optical semiconductor devices that use resin components with low heat resistance. However, as mentioned above, conventional hot melt silicone compositions have high practical curing temperatures in sealing processes, etc., and can cause deformation or deterioration of organic resins with low heat resistance.

[0005] On the other hand, in order to meet the demand for low-temperature curing, the present applicants proposed in Patent Document 3 (unpublished at the time of filing) a curable hot-melt silicone composition that contains an organopolysiloxane resin having a hydrosilylation-curing functional group such as a vinyl group and an ultraviolet-activated hydrosilylation catalyst, and that can be cured at a low temperature of 100°C or below. However, even when the composition is optimized by reducing the content of the cure retarder, the relationship between the curing rate and the industrial productivity associated with the sealing process may require high-temperature curing at around 120°C after activating the catalyst by irradiation with high-energy rays, leaving room for further improvement in terms of supporting fast-curing sealing processes at room temperature or low temperatures for organic resins with low heat resistance. Furthermore, Patent Document 3 does not mention or suggest the use of a resin having an acrylic or methacrylic group-linear structure-containing organopolysiloxane block copolymer, or any curing agent other than the hydrosilylation catalyst.

[0006] In response to this, active energy ray-curable hot-melt silicone compositions that utilize a thiol-ene reaction have been proposed in Patent Document 4 and elsewhere. These compositions are excellent in that they can be rapidly cured even at room temperature (low temperature), but have the drawback of having poor yellowing resistance in the cured product, making them difficult to use in applications where transparency is required.

[0007] International Publication (WO) No. 2016 / 136243 Pamphlet Japanese Patent Application Laid-Open No. 2014-009322 International Patent Application PCT / JP2021 / 12840 (unpublished at the time of filing) International Publication (WO) No. 2017 / 068762 Pamphlet

[0008] The object of the present invention is to provide a hot-melt silicone composition that can be cured over a wide temperature range from low to high depending on the sealing process and the heat resistance of the resin part, and that can achieve particularly good curing properties even at low temperatures such as room temperature, and that gives a cured product that is excellent in physical strength such as durability, transparency, and yellowing resistance, and that is also easy to handle in overmolding and other processes, as well as methods for using the composition.

[0009] As a result of extensive investigation, the present inventors have found that the silicon atom-bonded functional group (R Ａand a chain organosiloxane block Y consisting of a diorganosiloxane unit, and at least two of the above R Ａ The inventors have discovered that the above problems can be solved by a curable hot-melt silicone composition containing a resin-linear structure-containing organopolysiloxane block copolymer having the formula (I) and (B) a radical polymerization initiator, and have completed the present invention. This composition has excellent hot-melt properties and, depending on the radical polymerization initiator selected, can be heat-cured at high temperatures or cured at room temperature to low temperatures by irradiation with high-energy rays. The resulting cured product also has the advantages of being durable, transparent, and resistant to yellowing due to ultraviolet light, high temperatures, humidity, etc.

[0010] Specifically, the curable hot-melt silicone composition of the present invention comprises (A) R Ａ a R Ｂ （３－ａ） SiO 1 / 2 (R Ａ is a silicon-bonded functional group containing an acrylic or methacrylic group, and R Ｂ is R Ａ and a is a number ranging from 1 to 3). ＲＡ units) and SiO ４／２ and a resinous organosiloxane block X having an acrylic or methacrylic group, which comprises siloxane units (Q units) represented by the formula {R Ｃ ２ SiO ２ / ２} β (R Ｃ is a monovalent organic group, and β is a number of 2 or more), and a linear organosiloxane block Y having a siloxane unit represented by the formula (R Ａand 0.1 to 10 parts by mass of (B) a radical polymerization initiator. Here, component (B) may be a photoradical polymerization initiator, a thermal radical polymerization initiator, or a combination thereof. The type of component (B), as well as the curing method and curing temperature, may be selected appropriately depending on the sealing process using the hot-melt silicone composition of the present invention and the heat resistance of the object to be sealed.

[0011] In particular, when at least a portion of component (B) is (B1) a photoradical polymerization initiator, the composition is photocurable by irradiation with high-energy rays, making it possible to achieve an active energy ray-curable hot-melt silicone composition that exhibits good curability at room temperature.

[0012] Furthermore, the above-mentioned problems can be advantageously solved by the above-mentioned curable hot-melt silicone composition formed into a sheet or film, a release laminate containing the same, and a method for producing them.Similarly, the above-mentioned problems can be advantageously solved by a cured product obtained by curing the curable hot-melt silicone composition of the present invention, a semiconductor device or optical semiconductor device comprising the cured product, and a method for encapsulating them.

[0013] The curable silicone composition of the present invention has good hot-melt properties and can be cured over a wide temperature range, from low temperatures such as room temperature to high temperatures, by high-temperature heat curing and / or irradiation with high-energy rays such as ultraviolet rays, depending on the encapsulation process and heat resistance of the resin part. In particular, good curing properties can be achieved even at low temperatures such as room temperature, and the resulting cured product has excellent physical strength such as durability, transparency, and yellowing resistance, and is also easy to handle in processes such as overmolding. Therefore, by selecting the curing system, the composition can be suitably used as a encapsulant to protect a variety of encapsulation processes and substrate materials, particularly resin substrates with low heat resistance.

[0014] Furthermore, the present invention can provide such curable hot-melt silicone compositions in the form of void-free sheets or films having a thickness of 10 to 1,000 μm, or in the form of release laminates comprising the curable silicone composition sheet or film and a release sheet or film. In addition, sheets or films made from the curable silicone composition of the present invention, or release laminates comprising such sheets or films, can be cut to the desired size as needed for use in processes such as the production of electronic components, such as semiconductor devices, and can be used in industrial production processes such as bulk sealing and bulk bonding of large-area substrates. In particular, by selecting the right curing agent and curing system, a good sealing process can be achieved at low temperatures, such as room temperature, by irradiation with high-energy rays.

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the preferred embodiments. The present invention is not limited to the following embodiments, and various modifications can be made within the scope of the present invention.

[0016] As used herein, room temperature refers to the temperature of the environment in which someone is handling the curable silicone composition of the present invention, and generally refers to a temperature of 0°C to 40°C, particularly 15°C to 30°C, and especially 18°C ​​to 25°C.

[0017] In the present invention, unless otherwise specified, "having hot-melt properties" means that the softening point of the composition is between 50 and 200°C, that the composition has a melt viscosity at 150°C (preferably a melt viscosity of less than 1,000 Pa·s), and that the composition has flowable properties. Therefore, in this specification, the curable silicone composition of the present invention having hot-melt properties is also referred to simply as "curable hot-melt silicone composition." In particular, the curable hot-melt silicone composition of the present invention preferably has a complex viscosity of greater than 10,000 Pa·s before curing at 25°C, or is solid and not flowable, while preferably has a melt viscosity of less than 10,000 Pa·s before curing at 80°C, and more preferably has a complex viscosity of 100 to 10,000 Pa·s before curing at 80°C. It is more preferable that the complex viscosity of the composition before curing at 80°C be in the range of 200 to 9,000 Pa·s before curing. In particular, when the complex viscosity of the pre-cured composition at 80°C is within the above range, the composition has excellent low-temperature fluidity, which is advantageous in that it can be used to fill or mold the sealing portion of a substrate having low heat resistance at a relatively low temperature.

[0018] In the present invention, the complex viscosity at a certain temperature refers to the complex viscosity measured using a complex viscometer such as Anton Paar MCR302 within the range of 25°C to 100°C and recorded at a specific temperature.

[0019] [Curable Hot-Melt Silicone Composition] The curable hot-melt silicone composition of the present invention comprises: (A) R Ａ a R Ｂ （３－ａ） SiO １／２ (R Ａ is a silicon-bonded functional group containing an acrylic or methacrylic group, and R Ｂ is R Ａ and a is a number ranging from 1 to 3). ＲＡ units) and SiO ４／２ and a resinous organosiloxane block X having an acrylic or methacrylic group, which comprises siloxane units (Q units) represented by the formula {RＣ ２ SiO ２ / ２} β (R Ｃ is a monovalent organic group, and β is a number of 2 or more), and a linear organosiloxane block Y having a siloxane unit represented by the formula (R Ａ and (B) 0.1 to 10 parts by mass of a radical polymerization initiator, and further optionally, (C) a polymerizable compound having an R Ｂ ３ SiO １／２ and R Ａ ａ R Ｂ （３－ａ） SiO １／２ (wherein a represents an integer of 1 to 3, R Ｂ are each independently R Ａ (D) an organopolysiloxane resin containing M units represented by the formula (representing a monovalent organic group excluding R) and Q units in a ratio of M units to Q units in the range of 0.5 to 2.0; Ｂ ３ SiO １／２ (wherein R are independently R Ａ (representing a monovalent organic group excluding [R,R,R]) and Q units, with the ratio of M units to Q units being in the range of 0.5 to 2.0, (E) a polydimethylsiloxane which may optionally contain alkenyl groups, (F) an organic solvent, and (G) a known adhesion promoter. Furthermore, the curable hot-melt silicone composition of the present invention may contain other additives known in the art (e.g., heat-resistant additives) to the extent that the properties aimed at by the present invention can be maintained. Furthermore, when at least a portion of component (B) is (B1) a photoradical polymerization initiator, the present composition may, and preferably will, also contain (B') a photosensitizer.

[0020] Because the composition contains the above-mentioned component (A), it has curability derived from the radical polymerizable group, and is a solid with low or no fluidity at room temperature, but has hot-melt properties and becomes fluid when heated. When used in applications such as sealing substrates having uneven surfaces or between curved substrates, it can fill voids in the substrates etc. without excess or deficiency, and can be quickly cured by irradiation with high-energy rays or heating, allowing sealing with the cured product in a state where internal stress is sufficiently low, making it extremely useful in sealing processes for semiconductors etc.

[0021] The shape of the curable hot-melt silicone composition of the present invention is not particularly limited, but it may be, for example, molded into a sheet or film, with a sheet or film being particularly preferred. The components and optional components contained in the composition of the present invention are described below.

[0022] [Component (A)] Component (A) is the main component of the composition and is a resin-linear structure-containing organopolysiloxane block copolymer having a resinous organosiloxane block X and a chain-like organosiloxane block Y, each of which has a silicon-bonded functional group containing an acrylic or methacrylic group, and which contains at least two of the acrylic or methacrylic groups in its molecule. Component (A) as described above provides the composition as a whole with sufficient hot-melt properties for practical use, including good fluidity (melt viscosity) at around 80°C, and, because it contains specific radically polymerizable groups in its molecule, good curability can be achieved over a wide temperature range, from low temperatures such as room temperature to high temperatures, by selecting the radical polymerization initiator (B) and curing system.

[0023] More specifically, component (A) is R Ａ a R Ｂ （３－ａ） SiO 1 / 2 (R Ａ is a silicon-bonded functional group containing an acrylic or methacrylic group, and R Ｂ is R Ａ and a is a number ranging from 1 to 3). ＲＡ units) and SiO ４／２and a resinous organosiloxane block X having an acrylic or methacrylic group, which comprises siloxane units (Q units) represented by the formula {R Ｃ ２ SiO ２ / ２} β (R Ｃ is a monovalent organic group, and β is a number of 2 or more), and a linear organosiloxane block Y having a siloxane unit represented by the formula (R Ａ In order to provide the entire composition with a practically suitable melt viscosity (specifically, a range in which the complex viscosity of the pre-cured composition at 80°C is less than 10,000 Pa s), the molar ratio (ratio of substances) of the resinous organosiloxane block X to the linear organosiloxane block Y constituting component (A) is preferably in the range of 1:99 to 80:20, and more preferably in the range of 20:80 to 60:40. Note that a block copolymer in which these organosiloxane blocks (X and Y) satisfy the above molar ratio can be obtained by conducting a synthesis reaction by charging the raw materials that provide the X or Y block, described below, in the above molar ratio.

[0024] Component (A) is preferably a resin-linear structure-containing organopolysiloxane block copolymer having a structure in which silicon atoms constituting the resinous organosiloxane block X and the linear organosiloxane block Y are linked by siloxane bonds or silalkylene bonds, and the above-mentioned linking group can be introduced between the blocks by subjecting the raw materials described below that give the X or Y block to a condensation reaction or hydrosilylation reaction. From the standpoint of hot-melt properties, a structure in which block X and block Y are linked by siloxane bonds between silicon atoms is particularly preferred.

[0025] Component (A) is a resinous organosiloxane block X having a silicon atom-bonded functional group (R Ａ siloxane units (M ＲＡ units) and SiO ４／２and further comprising a siloxane unit (Q unit) represented by R Ｂ ３ SiO １／２ (R Ｂ is the above R Ａ From the viewpoint of the hot melt properties of the entire component (A), the ratio of M units and M units per mole of Q units in the resinous organosiloxane block X is preferably 1 mole. ＲＡ The sum of the amounts of the units is preferably in the range of 0.5 to 2.0 moles, more preferably in the range of 0.5 to 1.50 moles. Furthermore, the resinous organosiloxane block X contains a small amount of RSiO ３ / ２ (R is the above R Ａ a siloxane unit (T unit) represented by a monovalent organic group which may contain R ２ SiO ２ / ２ (R is a monovalent organic group as defined above), but the sum of the amounts of T units and D units per mole of Q units is preferably less than 0.1 moles. The ratio of the amounts of siloxane units (=molar ratio) in the resinous organosiloxane block X or the MQ-type organopolysiloxane resin that gives rise to said block X is ２９ This can be easily measured by Si nuclear magnetic resonance, and the same applies to the other components other than component (A).

[0026] The component (A) is a siloxane unit (M ＲＡ In particular, in order to realize the curing reaction, component (A) has a silicon atom-bonded functional group (R Ａ ), in addition to having M per mole of Q units in the resinous organosiloxane block X. ＲＡ The amount of the unit is preferably in the range of 0.02 to 0.50 moles, and more preferably in the range of 0.02 to 0.40 moles.

[0027] Silicon atom-bonded functional group R in component (A) Ａis not particularly limited as long as it has an acrylic group or a methacrylic group in the molecule, ＲＡ The functional group R having an acrylic or methacrylic group can be directly bonded to the silicon atom constituting the unit or bonded via a divalent or higher functional group. Ａ The reaction for introducing the group onto the resinous organosiloxane may be carried out by any reaction, and may be carried out either before or after the linking reaction of both blocks described below.

[0028] More specifically, R Ａ is represented by the general formula: In the formula, R １ are each independently a hydrogen atom, a methyl group, or a phenyl group, and are preferably a hydrogen atom or a methyl group to form an acrylic or methacrylic group moiety. Z is a divalent organic group which may contain a heteroatom and is bonded to a silicon atom which constitutes the main chain of the polysiloxane represented by *, and may be a divalent organic group which may contain a silicon atom, an oxygen atom, a nitrogen atom, or a sulfur atom.

[0029] where Z is an alkylene group having 2 to 22 carbon atoms; ３ -C(=O)-OR ４ - {wherein R ３ is an alkylene group having 2 to 22 carbon atoms, and R ４ is a group selected from an ethylene group, a propylene group, a methylethylene group, or a hexylene group; １ -X-C(=O)-X-Z ２ a divalent organic group represented by the formula - {wherein Z １ Ha -O(CH ２ ) ｋ - (k is a number ranging from 0 to 3), and X represents an oxygen atom, a nitrogen atom, or a sulfur atom. ２ is bonded to a silicon atom constituting the main chain of polysiloxane, where * is -[(CH ２ ) ２ O] ｍ (C ｎ H ２ｎ)-(m is a number ranging from 0 to 3, and n is a number ranging from 2 to 10)}, and —Z １ -R ２ ２ Si—O—R ２ ２ Si-Z ２ Preferably, the linking group is any one of the groups selected from the following divalent linking groups:

[0030] Particularly preferably, the silicon atom-bonded functional group (R Ａ ) is represented by the general formula (1): In the formula, R １ R each independently represents a hydrogen atom, a methyl group, or a phenyl group, and is preferably a hydrogen atom or a methyl group. ２ are each independently an alkyl group or an aryl group, and from an industrial standpoint, an alkyl group having 1 to 20 carbon atoms or a phenyl group is preferred, and a methyl group is particularly preferred. １ Ha -O(CH ２ ) ｍ - (m is a number ranging from 0 to 3), and m is preferably 1 or 2. Z ２ is bonded to a silicon atom constituting the main chain of polysiloxane, where * is -C ｎ H ２ｎ - (n is a number ranging from 2 to 10), and those in which n is 2 to 6 are practically preferred. Ａ ) is a silicon atom-bonded functional group (R Ａｌｋ The (meth)acrylic functional group can be introduced into a molecule by reacting the (meth)acrylic functional group with a hydrosilane compound having a silicon-bonded hydrogen atom and a (meth)acrylic functional group in the molecule (e.g., 3-(1,1,3,3-tetramethyldisiloxanyl)propyl methacrylate) in the presence of a hydrosilylation catalyst. This reaction may be, and is preferably, carried out in the presence of a polymerization inhibitor such as dibutylhydroxytoluene (BHT).

[0031] In addition, R in component (A) Ａ R is a monovalent organic group other than Bmay include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, and heptyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups such as benzyl and phenethyl; halogenated alkyl groups such as chloromethyl, 3-chloropropyl, and 3,3,3-trifluoropropyl; and alkenyl groups such as vinyl, allyl, butenyl, pentenyl, and hexenyl. From an industrial standpoint, it is particularly preferred that R contains at least one of methyl, phenyl, vinyl, and hexenyl groups. B At least a portion of may be, and preferably are, alkenyl groups having 2 to 12 carbon atoms.

[0032] The resinous organosiloxane block X in component (A) contains M ＲＡ In addition to the unit, as part of the M unit, R Ｂ（Aｌｋ） ３ SiO 1 / 2 (R Ｂ（Aｌｋ） is an alkenyl group having 2 to 12 carbon atoms) Ａｌｋ Such M Ａｌｋ The unit is a compound in which a silicon-bonded functional group containing at least one alkenyl group is hydrosilylated to form R Ａ The alkenyl group in component (A) may be a functional group that remains as an unreacted alkenyl group when the functional group R Ａ The M in the resinous organosiloxane block X has a radical polymerization reactivity similar to that of the M in the resinous organosiloxane block X, and can be radically polymerized in the presence of component (B). In addition, other curing reactions may be introduced to realize a dual curing system. Ａｌｋ The content of the units is preferably in the range of 0.01 to 0.25 mol, particularly preferably in the range of 0.05 to 0.10 mol, per mol of Q units.

[0033] The linear organosiloxane block Y in component (A) is R Ｃ ２ SiO ２ / ２ {R Ｃ２ SiO ２ / ２} β In this case, R Ｃ is a monovalent organic group, and the functional group R Ａ and R Ａ R is a monovalent organic group other than B From an industrial standpoint, it is particularly preferred that the functional group contains at least one of a methyl group, a phenyl group, a vinyl group, and a hexenyl group. β is a number of 2 or more, and since it is desirable from the standpoint of hot-melt properties that the molecule contains a linear molecular structure (=linear) made of polydiorganosiloxane of a certain chain length, β is preferably a number in the range of 5 to 5,000, and particularly preferably a number in the range of 10 to 2,000.

[0034] Such component (A) is R'SiO １ / ２ and siloxane units represented by ４／２ and an MQ-type organopolysiloxane resin having a reactive functional group at the molecular chain terminal, which contains a siloxane unit represented by the formula {R Ｃ ２ SiO ２ / ２} β where R' is a monovalent organic group, and the functional group R Ａ and R Ａ R is a monovalent organic group other than B Examples of functional groups include the same groups as those selected from one or more functional groups selected from the functional group R Ａ is introduced by a hydrosilylation reaction with a hydrosilane compound having a silicon-bonded hydrogen atom and a (meth)acrylic functional group, which is its precursor, at least some of the R' may be, and preferably are, alkenyl groups having 2 to 12 carbon atoms. In particular, after linking an organopolysiloxane resin with a linear organopolysiloxane to synthesize component (A) itself or its precursor, the alkenyl group R' in the molecule is reacted with a hydrosilane compound having a (meth)acrylic functional group, thereby introducing functional groups R into the molecule. ＡIt is particularly preferred to introduce

[0035] The method for linking the organopolysiloxane resin that provides the X block and the linear organopolysiloxane that provides the Y block is not particularly limited as long as it is a reaction that can chemically link the two blocks (hereinafter sometimes referred to as "block polymerization"); however, industrially, a reaction that provides a siloxane bond or a silalkylene bond is preferred, and examples thereof include a condensation reaction or a hydrosilylation reaction. In the former, the blocks are linked by a siloxane bond, and in the latter, the blocks are linked by a silalkylene bond. More specifically, examples of linking reactions between blocks include a dehydration condensation reaction of silanol, a decarboxylation condensation reaction of silanol and acetoxysilane, a dehydrogenation condensation reaction of silanol and hydrogensilane, a hydrolysis condensation reaction of alkoxysilane, and a hydrosilylation reaction between an alkenyl group and a silicon-bonded hydrogen atom.

[0036] When a condensation reaction is used for block polymerization, it is advisable to use an acid or base as a catalyst. To maintain the structure of each siloxane block, a weak acid or weak base is suitable. Examples include ammonia, acetic acid, and benzoic acid.

[0037] When a hydrosilylation reaction is used for block polymerization, the catalyst used is preferably a low-valent transition metal complex or a Lewis acid such as borane, and more preferably a known platinum-based metal complex hydrosilylation reaction catalyst.

[0038] The resin-linear structure-containing organopolysiloxane block copolymer, component (A), itself or its precursor copolymer can be obtained by combining the MQ-type organopolysiloxane resin that provides block X and the linear organopolysiloxane that provides block Y through the above-mentioned block polymerization, so molecular weight control is relatively easy through the selection of raw materials. In particular, from the standpoint of the hot-melt properties of this composition, when the molecular weight of component (A) is measured by gel permeation chromatography (GPC) or the like, it is preferable that the molecular weight distribution curve exhibits at least one maximum.

[0039] Component (A) has hot-melt properties and is non-flowable or has a complex viscosity of greater than 10,000 Pa·s at 25°C, but the complex viscosity (=melt viscosity) at 80°C is preferably in the range of less than 10,000 Pa·s, more preferably in the range of 100 to 10,000 mPa·s, and especially preferably in the range of 200 to 9,000 mPa·s. A curable hot-melt silicone composition can be designed from such component (A) simply by combining it with radical polymerization initiator (B).

[0040] [Component (B)] Component (B) is a radical polymerization initiator and may be (B1) a photoradical polymerization initiator, (B2) a thermal radical polymerization initiator, or a combination thereof. The type of component (B), curing method, and curing temperature may be appropriately selected depending on the sealing process using the composition and the heat resistance of the object to be sealed. Component (A) according to the present invention not only has hot-melt properties, but also contains a silicon-bonded functional group containing a radically polymerizable acrylic or methacrylic group in the molecule, and optionally also an alkenyl group, and therefore can achieve good curability by irradiation with high-energy rays and / or heating in the presence of component (B).

[0041] The amount of component (B) used is 0.1 to 10 parts by mass, and particularly preferably 0.2 to 5 parts by mass, per 100 parts by mass of component (A). The amount of component (B) used also depends on the sealing process in which the composition is applied, the curing time, and the amount of silicon-bonded functional groups (R Ａ The heat resistance can be appropriately designed within the above range depending on the content of the component (II), the amount of high-energy radiation irradiated and / or the heating conditions.

[0042] Component (B1) is a photoradical polymerization initiator that, upon irradiation with high-energy rays such as ultraviolet light, converts the silicon atom-bonded functional groups (R Ａ ) is a component that accelerates the photocuring reaction of the acrylic or methacrylic groups.

[0043] Although known photoradical polymerization initiators are roughly divided into photocleavage type and hydrogen abstraction type, the photoradical polymerization initiator used in the composition of the present invention can be arbitrarily selected from those known in the art and is not particularly limited to a specific one. Note that some photoradical polymerization initiators can promote the curing reaction not only by irradiation with high-energy rays such as ultraviolet rays but also by irradiation with light in the visible light region.

[0044] Specific examples of the photoradical polymerization initiator include α-ketol compounds such as 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone, α-hydroxy-α,α'-dimethylacetophenone, 2-methyl-2-hydroxypropiophenone, and 1-hydroxycyclohexylphenyl ketone; acetophenone compounds such as methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, and 2-methyl-1-[4-(methylthio)-phenyl]-2-morpholinopropane-1; benzoin ether compounds such as benzoin ethyl ether, benzoin isopropyl ether, and anisoin methyl ether; and benzyldimethyl ether. aromatic sulfonyl chloride compounds such as 2-naphthalenesulfonyl chloride; photoactive oxime compounds such as 1-phenone-1,1-propanedione-2-(o-ethoxycarbonyl)oxime; benzophenone compounds such as benzophenone, benzoylbenzoic acid, and 3,3'-dimethyl-4-methoxybenzophenone; thioxanthone compounds such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, and 2,4-diisopropylthioxanthone; camphorquinone; and halogenated ketones.

[0045] Similarly, examples of photoradical polymerization initiators suitable as the component (B1) in the present invention include bis-(2,6-dichlorobenzoyl)phenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide. side, bis(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,4,6-trimethylbenzoyl)-phenylphosphine oxide and other bisacylphosphine oxides; 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenyl Phosphine oxide, monoacylphosphine oxides such as 2,4,6-trimethylbenzoylphenylphosphinic acid methyl ester, 2-methylbenzoyldiphenylphosphine oxide, pivaloylphenylphosphinic acid isopropyl ester, and 2,4,6-trimethylbenzoyldiphenylphosphine oxide; anthraquinone, chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, and 2-amyl anthraquinone. Anthraquinones such as anthraquinone and 2-aminoanthraquinone; benzoic acid esters such as ethyl-4-dimethylaminobenzoate, 2-(dimethylamino)ethyl benzoate, and p-dimethylbenzoic acid ethyl ester; titanocenes such as bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl)titanium and bis(cyclopentadienyl)-bis[2,6-difluoro-3-(2-(1-pyr-1-yl)ethyl)phenyl]titanium;Examples include phenyl disulfide 2-nitrofluorene, butyroin, anisoin ethyl ether, azobisisobutyronitrile, and tetramethylthiuram disulfide;

[0046] Commercially available acetophenone-based photopolymerization initiators suitable as component (B1) in the present invention include Omnirad 907, 369, 369E, and 379 manufactured by IGM Resins. Commercially available acylphosphine oxide-based photopolymerization initiators include Omnirad TPO, TPO-L, and 819 manufactured by IGM Resins. Commercially available oxime ester-based photopolymerization initiators include Irgacure OXE01 and OXE02 manufactured by BASF Japan Ltd., N-1919 and ADEKA Arcles NCI-831 and NCI-831E manufactured by ADEKA Corporation, and TR-PBG-304 manufactured by Changzhou New Advanced Electronic Materials Co., Ltd.

[0047] Component (B2) is a thermal radical polymerization initiator that generates radical species upon heating and reacts with silicon atom-bonded functional groups (R Ａ The thermal radical polymerization initiator is a component that accelerates the curing reaction of the acrylic or methacrylic group of the copolymer. Examples of such a thermal radical polymerization initiator include azo compounds and organic peroxides.

[0048] Examples of azo compounds include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 1,1'-azobis-1-cyclohexanecarbonitrile, dimethyl-2,2'-azobisisobutyrate, dimethyl-2,2'-azobis(2-methylpropionate), dimethyl-1,1'-azobis(1-cyclohexanecarboxylate), 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis(2-amidinopropane) dihydrochloride, 2-tert-butylazo-2-cyanopropane, 2,2'-azobis(2-methylpropionamide) dihydrate, and 2,2'-azobis(2,4,4-trimethylpentane).

[0049] Examples of organic peroxides include alkyl peroxides, diacyl peroxides, peroxide esters, and carbonate peroxides. Specific examples of alkyl peroxides include dicumyl peroxide, di-tert-butyl peroxide, di-tert-butylcumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, tert-butylcumyl, 1,3-bis(tert-butylperoxyisopropyl)benzene, and 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxonane. Examples of diacyl peroxides include benzoyl peroxide, lauroyl peroxide, and decanoyl peroxide. Examples of peroxide esters include 1,1,3,3-tetramethylbutylperoxyneodecanoate, α-cumylperoxyneodecanoate, tert-butylperoxyneodecanoate, tert-butylperoxyneoheptanoate, tert-butylperoxypivalate, tert-hexylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, and tert-amylperoxy-2-ethylhexanoate. , tert-butylperoxy-2-ethylhexanoate, tert-butylperoxyisobutyrate, di-tert-butylperoxyhexahydroterephthalate, tert-amylperoxy-3,5,5-trimethylhexanoate, tert-butylperoxy-3,5,5-trimethylhexanoate, tert-butylperoxyacetate, tert-butylperoxybenzoate, and di-butylperoxytrimethyladipate are examples. Examples of peroxycarbonates include di-3-methoxybutyl peroxydicarbonate, di(2-ethylhexyl) peroxydicarbonate, diisopropyl peroxycarbonate, tert-butylperoxyisopropyl carbonate, di(4-tert-butylcyclohexyl) peroxydicarbonate, dicetyl peroxydicarbonate, and dimyristyl peroxydicarbonate.

[0050] [Component (B'): Photosensitizer] The present composition may optionally contain a photosensitizer (B') in combination with the photoradical polymerization initiator (B1). The use of a sensitizer can increase the photon quantum efficiency of the polymerization reaction, allowing longer wavelength light to be utilized in the polymerization reaction compared to when a photoinitiator alone is used. This is known to be particularly effective when the composition is coated to a relatively thick thickness or when a relatively long wavelength LED light source is used. Known sensitizers include anthracene-based compounds, phenothiazine-based compounds, perylene-based compounds, cyanine-based compounds, merocyanine-based compounds, coumarin-based compounds, benzylidene ketone-based compounds, (thio)xanthene or (thio)xanthone-based compounds, such as isopropylthioxanthone, 2,4-diethylthioxanthone, squarylium-based compounds, (thia)pyrylium-based compounds, and porphyrin-based compounds. However, any photosensitizer can be used in the curable organopolysiloxane composition and pressure-sensitive adhesive composition of the present invention, without limitation. The amount used is arbitrary, but is generally selected so that the mass ratio of component (B') to component (B1) is in the range of 0 to 10, and when used, is in the range of 0.01 to 5.

[0051] [Selection of Component (B) and Curing Method] The present composition contains the above-described components (A) and (B), and thus forms a cured product by a radical polymerization reaction. Here, when at least a portion of component (B) is (B1) a photoradical polymerization initiator, the present composition can be cured by irradiating it with high-energy rays such as ultraviolet rays. Similarly, when at least a portion of component (B) is (B2) a thermal radical polymerization initiator, the present composition can be cured by heating. Furthermore, by combining the two, it is possible to selectively or combinedly cure the composition by heating and high-energy ray irradiation, and these methods can be appropriately selected depending on the desired curing method and sealing process.

[0052] In particular, since the composition according to the present invention contains component (A) with hot-melt properties and a (meth)acrylic group-containing group, it is suitable for a process in which the composition is melted by heating, fills the irregularities of the substrate or member to be sealed, and then cured under low stress. Here, since the composition is capable of rapid curing even at low temperatures, including room temperature, even for substrates or members with poor heat resistance, and the cured product has excellent transparency and UV yellowing resistance, it is suitable for use in a photocuring process involving irradiation with high-energy rays. In this case, it is particularly preferred that at least a portion of component (B) is a photoradical polymerization initiator (B1) and optionally further contains a photosensitizer (B'). On the other hand, when the substrate or member to be sealed has sufficient heat resistance, if at least a portion of component (B) is a thermal radical polymerization initiator (B2), there is the advantage that rapid curing is possible at high temperatures.

[0053] [Component (C)] The composition of the present invention further comprises a component (C) having R Ｂ ３ SiO １／２ and R Ａ ａ R Ｂ （３－ａ） SiO １／２ In the formula, a represents an integer of 1 to 3, and R represents an integer of 1 to 3. Ａ is a silicon-bonded functional group containing an acrylic or methacrylic group, and R Ｂ is R Ａ and examples thereof include the same groups as those described above. Furthermore, at least one of the M units constituting the component (C) is a monovalent organic group other than R Ａ ａ R Ｂ （３－ａ） SiO １／２ The functional group R Ａ The triorganosiloxy unit comprises:

[0054] Component (C) is an MQ-type organopolysiloxane resin having an acrylic or methacrylic group in the molecule, and at least one R ＡSince it has a silicon-bonded functional group containing an acrylic or methacrylic group represented by the formula (I), it participates in the same curing reaction as component (A). Component (C) is an optional component that adjusts the adhesion to a substrate, the crosslink density of the cured product, and the melt viscosity, and it is possible to adjust the hardness of the cured product of this composition and its adhesion to a substrate depending on the amount of component used.

[0055] Component (C) contains a small amount of RSiO ３ / ２ (R is the above R Ａ a siloxane unit (T unit) represented by a monovalent organic group which may contain R ２ SiO ２ / ２ (R is the same monovalent organic group as above) may contain a siloxane unit (D unit) represented by the above R Ｂ ３ SiO １／２ and R Ａ ａ R Ｂ （３－ａ） SiO １／２ The sum of the amounts of T and D units per mole of Q units in component (C) is preferably less than 0.1 moles.

[0056] The molar ratio of M units to Q units in component (C) is in the range of 0.5 to 2.0, preferably in the range of 0.5 to 1.5, more preferably in the range of 0.55 to 1.20, and particularly preferably in the range of 0.60 to 1.10.

[0057] The amount of component (C) used is not particularly limited and may be any amount, but is preferably within the range of 0.1 to 50 parts by mass, and particularly preferably 0.1 to 25 parts by mass, per 100 parts by mass of component (A).

[0058] [Component (C')] The composition of the present invention may optionally contain a silicon atom-bonded functional group (R Ａ Specifically, the composition may contain one or more linear organopolysiloxanes selected from the following components (C'1) and (C'2):

[0059] The component (C'1) is a functional group (R Ａ ) in the molecule.

[0060] Structural formula (C'-1):

[0061] In the formula, R １ are each independently a C1 to C6 alkyl group, a C2 to C20 alkenyl group, or a C6 to C12 aryl group; R Ａ’ are each independently a C1 to C6 alkyl group, a C2 to C20 alkenyl group, a C6 to C12 aryl group, and a silicon atom-bonded functional group (R Ａ ), n1 is a positive number, and n2 is 0 or a positive number. However, when n2 is 0, R Ａ’ At least one of the groups is a silicon atom-bonded functional group (R Ａ ) n1+n2 is a positive number of 0 or greater, and is not limited, but is preferably in the range of 10 to 5000, more preferably 10 to 2000, and even more preferably 10 to 1000. The value of n1+n2 may be, and is preferably, a number such that the viscosity of component (C'1) at 25°C falls within the range of 1 to 100,000 mPa s, more preferably 10 to 50,000 mPa s, and even more preferably 500 to 50,000 mPa s.

[0062] The component (C'2) is a copolymer having a functional group (R Ａ Component (C'2) is a branched-chain organopolysiloxane that contains at least one or more branched siloxane units within the molecule. Unlike components (A) and (C), component (C'2) does not contain an MQ-type organopolysiloxane resin structure, and the T units or Q units within its molecule are contained solely as branched units of the linear organopolysiloxane.

[0063] Average unit formula (C'-2): (R Ａ’ R １ ２ SiO １／２ )x (R １ ２ SiO ２／２ ) ｙ１ (R Ａ’ R １ SiO ２／２ ) ｙ２ (R １ SiO ３／２ ) ｚ１ (R Ａ’ SiO ３／２ ) ｚ２ (I-2)

[0064] In the above formula, R １ , R Ａ’ is the same group as above, and x, y1, y2, z1, and z2 represent the ratio of the amount of substance when the sum of the siloxane units is 1. Specifically, when all of the following conditions are satisfied: x + y1 + y2 + z1 + z2 = 1, 0 < x ≦ 0.2, 0.3 ≦ y1 + y2 < 1, 0 < z1 + z2 ≦ 0.2, and y2 + z2 = 0, R Ａ’ At least one of the groups is a silicon atom-bonded functional group (R Ａ ) Either or both of y2 and z2 may be 0.

[0065] More specifically, component (C'2) is a branched-chain organopolysiloxane represented by the following siloxane unit formula: (R Ａ’ R １ ２ SiO １／２ ) a (R １ ２ SiO ２／２ ) b１ (R Ａ’ R １ SiO ２／２ ) b２ (R １ SiO ３／２ ) c１ (R Ａ’ SiO ３／２ ) c２ (In the formula, R １ , R Ａ’ are the same groups as above), 0<a≦10, 15≦b1+b2<2000, 0<c1+c2≦10, and when b2+c2=0, R Ａ’At least one of the groups is a silicon atom-bonded functional group (R Ａ )

[0066] As an example, component (C'2) may be a branched-chain organopolysiloxane having a methacryloyl group-containing organic group only on the terminal M unit represented by the following siloxane unit formula: (R Ａ’ R １ ２ SiO １／２ ) a (R １ ２ SiO ２／２ ) b１ (R １ SiO ３／２ ) c１ In the formula, R １ , R Ａ’ is the same group as above, 0<a≦10, 15≦b1<2000, 0<c1≦10, R Ａ’ At least one of the groups is a silicon atom-bonded functional group (R Ａ )

[0067] The viscosity of component (C'2) at 25°C is preferably 10 to 50,000 mPa·s, and more preferably 100 to 2,000 mPa·s.

[0068] Like component (C), the linear organopolysiloxane of component (C') contains at least one R Ａ Since it has a silicon-bonded functional group containing an acrylic or methacrylic group represented by the formula (I), it participates in the same curing reaction as component (A). Component (C') is an optional component that adjusts the adhesion to a substrate, the crosslink density of the cured product, and the melt viscosity. Depending on the amount of this component used, it is possible to adjust the hardness of the cured product of the composition and the adhesion to a substrate, and it may be particularly useful for adjusting the crosslink density, etc.

[0069] There are no particular restrictions on the amount of chain organopolysiloxane used as component (C'), but it is preferably in the range of 0.1 to 50 parts by weight, and particularly preferably 0.1 to 25 parts by weight, per 100 parts by weight of component (A).

[0070] [Component (D)] The composition according to the present invention further comprises a compound (D) containing R Ｂ ３ SiO １／２ and Q units, in which the ratio of M units to Q units is in the range of 0.5 to 2.0. Ｂ is R Ａ The monovalent organic group is exemplified by the same groups as those described above. Unlike component (C), component (D) does not contain a functional group R Ａ and R Ａ It does not contain siloxane units containing:

[0071] Component (D) is an MQ-type organopolysiloxane resin that does not contain acrylic or methacrylic groups within the molecule. While it does not participate in the same curing reaction as component (A), it is an optional component that adjusts adhesion to substrates, crosslink density, and melt viscosity of the cured product. Depending on the amount of this component used, it is possible to adjust the hardness and adhesion to substrates of the cured product of this composition.

[0072] Component (D) contains a small amount of R Ｂ SiO ３ / ２ Siloxane units (T units) represented by the formula: Ｂ ２ SiO ２ / ２ Although it may contain a siloxane unit (D unit) represented by the above R Ｂ ３ SiO １／２ The sum of the amounts of T and D units per mole of Q units in component (D) is preferably less than 0.1 moles.

[0073] The molar ratio of M units to Q units in component (D) is in the range of 0.5 to 2.0, preferably in the range of 0.5 to 1.5, more preferably in the range of 0.55 to 1.20, and particularly preferably in the range of 0.60 to 1.10.

[0074] The amount of component (D) used is not particularly limited and may be any amount, but is preferably within a range of 0.1 to 200 parts by mass, more preferably 5 to 150 parts by mass, and particularly preferably 10 to 100 parts by mass, per 100 parts by mass of component (A).

[0075] [Component (E)] The composition of the present invention may further contain (E) a polydimethylsiloxane which may optionally have an alkenyl group. Component (E) itself has fluidity, so by using it together with the above-mentioned component (A) or the like, it may be possible to adjust the melting properties of the composition, the adhesion of the cured product to a substrate, hardness, crosslink density, etc.

[0076] More specifically, component (E) is a polydimethylsiloxane that is liquid or plastic at 25°C and optionally contains at least two alkenyl groups having 2 to 20 carbon atoms in the molecule. Component (A) described above is expressly excluded from the scope of component (E), and suitable component (E) is a cyclic, linear, branched, resinous, or rubber-like polydimethylsiloxane in which some of the methyl groups bonded to silicon atoms may be substituted with alkenyl groups having 2 to 20 carbon atoms.

[0077] The polydimethylsiloxane of component (E) is not particularly limited in terms of its degree of polymerization or viscosity range, but may have a viscosity at 25°C in the range of 1.5 to 1,000,000 mPa s, and may be either a liquid polydimethylsiloxane having a viscosity of 100,000 mPa s or greater at 25°C, or a crude rubber-like polydimethylsiloxane with a plasticity measured according to the method specified in JIS K6249 (measure the thickness of a 4.2 g spherical sample at 25°C under a load of 1 kgf for 3 minutes, read to the nearest 1 / 100 mm, and multiply this value by 100) in the range of 50 to 200. Furthermore, the content of vinyl (CH2=CH) moieties in the alkenyl groups of component (E) (hereinafter referred to as the "vinyl content") is optional, but may be in the range of 0.000 to 1.500 mass%, or even 0.050 to 1.000 mass%. Component (E) also includes cyclic polydimethylsiloxanes with a degree of siloxane polymerization of 3 to 20, which may optionally contain alkenyl groups. Furthermore, when component (E) is a chain molecule, the molecular chain terminals may be capped with a non-reactive trialkylsilyl group such as a trimethylsilyl group, or may be capped with a reactive functional group such as an alkenyldimethylsilyl group such as a vinyldimethylsilyl group, an alkoxydimethylsilyl group, or a hydroxydimethylsilyl group.

[0078] [(F) Organic Solvent] The composition according to the present invention may optionally contain (F) an organic solvent. The organic solvent may be used as a diluent for dispersing or dissolving each component in order to improve the coatability or wettability of the composition to a substrate, or may be a component inevitably contained as a solvent accompanying other raw material components.

[0079] The organic solvent that can be used in the present invention is not particularly limited in type as long as it is a compound that can dissolve all or some of the constituent components in the composition, as long as the technical effects of the present invention are not impaired, and preferably has a boiling point of 80° C. or higher and 200° C. or lower. The type may be a non-halogenated solvent or a halogenated solvent, and examples include aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents, ester solvents, alcohol solvents, ether solvents, chlorinated aliphatic hydrocarbon solvents, and volatile oil solvents, and two or more types may be combined depending on the coatability, wettability, etc.

[0080] More specifically, examples of the solvent include i-propyl alcohol, t-butyl alcohol, cyclohexanol, cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene, benzene, heptane, hexane, octane, isoparaffin, mesitylene, 1,4-dioxane, dibutyl ether, anisole, 4-methylanisole, ethylbenzene, ethoxybenzene, ethylene glycol, diisopropyl ether, 1,4-dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, 2-methoxyethanol (ethylene glycol monomethyl ether), diethylene glycol dimethyl ether, diethylene glycol monomethyl ether, dipropylene glycol Examples of suitable solvents include non-halogenated solvents such as ethylene glycol methyl ether acetate, ethyl acetate, butyl acetate, propyl propionate (=propyl propionate), 1-methoxy-2-propyl acetate, 1-ethoxy-2-propyl acetate, octamethylcyclotetrasiloxane, and hexamethyldisiloxane; and halogenated solvents such as trichloroethylene, perchloroethylene, methylene chloride, trifluoromethylbenzene, 1,2-bis(trifluoromethyl)benzene, 1,3-bis(trifluoromethyl)benzene, 1,4-bis(trifluoromethyl)benzene, trifluoromethylchlorobenzene, trifluoromethylfluorobenzene, and hydrofluoroethers.

[0081] Because this composition is a hot-melt silicone composition with low to no fluidity at 25°C, the content of the organic solvent (F) must be small enough so that the hot-melt properties are not impaired by a large amount of organic solvent. As an example, it is particularly preferred that the content of component (F) be 0 to less than 5 mass% per 100 parts by mass of the total composition. In particular, when this composition is molded into a sheet or film as described below, it is preferred that the component (F) used for molding be removed by heating or the like.

[0082] [(G) Adhesion Imparting Agent] The present composition may further contain a known adhesion imparting agent as component (G). Component (G) improves the adhesive strength of the cured product obtained by curing the present composition to a substrate, and one or more known adhesion imparting agents may be selected and used. In particular, by using a compound having two or more alkoxysilyl groups in the molecule as at least a part of component (G), adhesive strength may be significantly improved after a certain period of time has passed.

[0083] The amount of component (G) used is 0.01 to 5 parts by mass, and particularly preferably 0.02 to 2 parts by mass, based on 100 parts by mass of the entire composition of the present invention. If the amount of component (G) used is less than the above-mentioned lower limit, the adhesive strength to the substrate may not be sufficiently improved, whereas if it exceeds the above-mentioned upper limit, compatibility with other components may be poor or the appearance of the cured product may be affected over time.

[0084] Preferably, component (G) contains an organic compound having two or three alkoxysilyl groups at the molecular chain terminals. The organic compound here includes organosilicon compounds in addition to alkane compounds.

[0085] Specific examples of organic compounds having two alkoxysilyl groups at the molecular chain terminals include 1,2-bis(trimethoxysilyl)ethane, 1,2-bis(triethoxysilyl)ethane, 1,2-bis(methyldimethoxysilyl)ethane, 1,2-bis(methyldiethoxysilyl)ethane, 1,3-bis(trimethoxysilyl)propane, 1,4-bis(trimethoxysilyl)butane, 1,4-bis(triethoxysilyl)butane, 1-methyl dimethoxysilyl-4-trimethoxysilylbutane, 1-methyldiethoxysilyl-4-triethoxysilylbutane, 1,4-bis(methyldimethoxysilyl)butane, 1,4-bis(methyldiethoxysilyl)butane, 1,5-bis(trimethoxysilyl)pentane, 1,5-bis(triethoxysilyl)pentane, 1,4-bis(trimethoxysilyl)pentane, 1,4-bis(triethoxysilyl)pentane, 1-methyldi Methoxysilyl-5-trimethoxysilylpentane, 1-methyldiethoxysilyl-5-triethoxysilylpentane, 1,5-bis(methyldimethoxysilyl)pentane, 1,5-bis(methyldiethoxysilyl)pentane, 1,6-bis(trimethoxysilyl)hexane, 1,6-bis(triethoxysilyl)hexane, 1,4-bis(trimethoxysilyl)hexane, 1,5-bis(trimethoxysilyl)hexane, 2,5 -bis(trimethoxysilyl)hexane, 1-methyldimethoxysilyl-6-trimethoxysilylhexane, 1-phenyldiethoxysilyl-6-triethoxysilylhexane, 1,6-bis(methyldimethoxysilyl)hexane, 1,7-bis(trimethoxysilyl)heptane, 2,5-bis(trimethoxysilyl)heptane, 2,6-bis(trimethoxysilyl)heptane, 1,8-bis(trimethoxysilyl)octane, 1,Alkane compounds having two alkoxysilyl groups such as 8-bis(methyldimethoxysilyl)octane, 2,5-bis(trimethoxysilyl)octane, 2,7-bis(trimethoxysilyl)octane, 1,9-bis(trimethoxysilyl)nonane, 2,7-bis(trimethoxysilyl)nonane, 1,10-bis(trimethoxysilyl)decane, and 3,8-bis(trimethoxysilyl)decane; 1,3-bis{2-(trimethoxysilyl)ethyl}-1,1,3,3-tetramethyldisiloxane; 1,3-bis{2-(methyldimethoxysilyl)ethyl}-1,1,3,3-tetramethyldisiloxane; Examples of the alkoxysilyl group-containing disiloxane compounds include disiloxane compounds having two alkoxysilyl groups, such as 1,3-bis{2-(triethoxysilyl)ethyl}-1,1,3,3-tetramethyldisiloxane, 1,3-bis{2-(methyldiethoxysilyl)ethyl}-1,1,3,3-tetramethyldisiloxane, 1,3-bis{6-(trimethoxysilyl)hexyl}-1,1,3,3-tetramethyldisiloxane, and 1,3-bis{6-(triethoxysilyl)hexyl}-1,1,3,3-tetramethyldisiloxane.

[0086] Similarly, examples of organic compounds having three alkoxysilyl groups include trisiloxane compounds having three alkoxysilyl groups, such as 1,3,5-tris{2-(trimethoxysilyl)ethyl}-1,1,3,5,5-pentamethyltrisiloxane, 1,3,5-tris{2-(methyldimethoxysilyl)ethyl}-1,1,3,5,5-tetramethyldisiloxane, 1,3,5-tris{2-(triethoxysilyl)ethyl}-1,1,3,5,5-tetramethyldisiloxane, 1,3,5-tris{2-(methyldiethoxysilyl)ethyl}-1,1,3,5,5-tetramethyldisiloxane, and 1,3,5-tris{6-(trimethoxysilyl)hexyl}-1,1,3,5,5-tetramethyldisiloxane. An example of the structure is (MeO) ３ SiCH ２ CH ２ (Me) ２ Si-O-SiMe(CH ２ CH ２ Si(OMe) ３ )-O-Si(Me)２ CH ２ CH ２ Si(OMe) ３ (where Me is a methyl group).

[0087] Furthermore, as component (G) in the present invention, in addition to silane compounds such as 3-glycidoxypropyltrimethoxysilane, organosiloxane oligomers, and alkyl silicates, reaction mixtures of amino-containing organoalkoxysilanes and epoxy-containing organoalkoxysilanes disclosed in Japanese Patent Publication No. 52-8854 and Japanese Patent Laid-Open Publication No. 10-195085 can also be used, and are preferred. In particular, carbasilatrane derivatives having a silicon-bonded alkoxy group or silicon-bonded alkenyl group per molecule, and silatrane derivatives having an alkoxysilyl-containing organic group can be used. These are also disclosed in the above-mentioned Patent Documents 1 to 4, and an appropriate adhesion promoter can be selected from these.

[0088] [(H) Thiol Compound] The composition according to the present invention may further contain (H) a polyfunctional thiol compound having at least two thiol groups in the molecule. The polyfunctional thiol compound acts as a chain transfer agent to promote radical polymerization reactions. Therefore, particularly when a part of component (B) according to the present invention is a photoradical polymerization initiator and the composition is cured by irradiation with high-energy rays such as ultraviolet rays, the polyfunctional thiol compound can improve the curing rate and deep curability of the cured product even when the irradiation dose of high-energy rays is small, and also functions as a crosslinking point in the composition.

[0089] Examples of such polyfunctional thiol compounds include pentaerythritol tetrakis(3-mercaptobutyrate), 1,4-bis(3-mercaptobutyryloxy)butane, 1,3,5-tris(2-(3-sulfanylbutanoyloxy)ethyl)-1,3,5-triazinane-2,4,6-trione, and trimethylolpropane tris(3-mercaptobutyrate).

[0090] The use of component (H) is optional, but the amount used is 0 to 20 parts by mass, preferably 0 to 10 parts by mass, and particularly preferably 0 to 5 parts by mass, per 100 parts by mass of component (A).

[0091] Furthermore, the present composition may contain other optional components, as long as they do not impair the objectives of the present invention, such as heat-resistant agents such as iron oxide (red iron oxide), cerium oxide, cerium dimethylsilanolate, fatty acid cerium salts, cerium hydroxide, and zirconium compounds; antioxidants such as phenols, quinones, amines, phosphorus, phosphites, sulfur, and thioethers; light stabilizers such as triazoles and benzophenones; flame retardants such as phosphate esters, halogens, phosphorus, and antimony; and one or more antistatic agents such as cationic surfactants, anionic surfactants, and nonionic surfactants. In addition to these components, the composition of the present invention may also optionally contain pigments, dyes, inorganic fine particles (reinforcing fillers, dielectric fillers, conductive fillers, thermally conductive fillers), and the like, depending on the intended use.

[0092] The curable hot-melt silicone composition of the present invention may be used in the form of granules, pellets, sheets, or films.

[0093] The composition may be formed into a sheet or film for use. For example, sheets or films made from the curable silicone composition of the present invention and having an average thickness of 10 to 1,000 μm possess hot-melt properties and, depending on the type of component (B), are curable through a radical polymerization reaction triggered by irradiation with high-energy rays or heating, which provides excellent handling and melting properties, making them particularly advantageous for use in overmolding and the like.

[0094] [Laminate containing curable hot-melt silicone composition and its use as film adhesive / sealant] This curable hot-melt silicone composition can be used in the form of a sheet or film, and in particular can be used as a laminate having a structure in which a sheet material made of the above-mentioned curable hot-melt silicone composition is sandwiched between two film substrates with a release layer.This film substrate with a release layer (generally called release film) can be peeled off from the sheet material made of the curable hot-melt silicone composition when the sheet material is used as an adhesive or sealant, etc.Hereinafter, this laminate will also be called a peelable laminate.

[0095] The above-mentioned sheet or film of the curable hot-melt silicone composition can be obtained by the following steps: Step (I): applying the above-mentioned curable hot-melt silicone composition to a substrate; and Step (II): heating and drying the composition applied in Step (I) to obtain a composition molded into a sheet or film. Here, when applying the curable hot-melt silicone composition in Step (I), it may be heated and melted by itself and applied to the substrate in a fluid state, or it may be applied to the substrate in the form of a dispersion solution using an organic solvent, and the organic solvent may then be removed in Step (II). If a release layer is present on the substrate, the sheet or film of the curable hot-melt silicone composition can be obtained as part of the release laminate described below.

[0096] The method for producing the above-mentioned release laminate is not particularly limited, but one example includes the following steps: Step 1: mixing the components of the curable hot-melt silicone composition; Step 2: kneading the mixture obtained in Step 1 while heating and melting; Step 3: laminating the heated and melted mixture obtained in Step 2 between two release films with at least one release surface, so that the mixture contacts the release surface, to form a laminate; Step 4: pressing the laminate obtained in Step 3 between rolls to roll out the mixture sandwiched between the two release films, thereby forming a curable hot-melt silicone composition sheet or film with a specific thickness. Optionally, a roll with a cooling or temperature-regulating function may be used in Step 4. Furthermore, a step of cutting the resulting laminate containing the curable hot-melt silicone composition sheet or film may be added after Step 4. Alternatively, instead of Step 2, the mixture obtained in Step 1 may be dispersed in an organic solvent and applied to a release film, and the organic solvent may then be removed by heating or other means before Step 3.

[0097] There is no particular limit to the thickness of this release film, and therefore it includes what is generally called a film as well as what is called a sheet. However, in this specification, it is called a release film regardless of its thickness.

[0098] The temperature for the mixing step in step 1 is not particularly limited, but heating may be performed as necessary to ensure that the components are thoroughly mixed, and the heating temperature can be, for example, 50°C or higher.

[0099] By peeling the release film from the release laminate of the present invention, a sheet or film comprising a curable hot-melt silicone composition is obtained. Accordingly, 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 the sheet or film is preferably flat. "Flat" means that the thickness of the resulting 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.

[0100] The type of material for the substrate of the release film constituting the release laminate is not particularly limited, but for example, polyester film, polyolefin film, polycarbonate film, acrylic film, etc. can be used appropriately. 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 releasability, and such treatment is known in the art.

[0101] A layer having releasability provided on the surface of a release film is called a release layer. This release layer is designed to allow a sheet or film made of a curable silicone composition to be easily peeled from a film-like substrate, and is sometimes called a release liner, separator, release layer, or release coating layer. Preferably, the release layer can be formed as a release 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 provided with fine irregularities to reduce adhesion to the curable silicone composition, or the substrate may be made of a material that is less likely to adhere to a 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 obtained by curing a fluorine-based release agent or a fluorosilicone-based release agent.

[0102] The above laminate can be used, for example, by peeling off one of the two release films that make up the laminate, applying an uncured sheet or film-like member made of the curable silicone composition that is not in contact with the release film to an adherend, and then peeling the uncured sheet or film-like member from the other film-like substrate, i.e., the release film.

[0103] The present curable silicone composition can be handled in the form of granules, pellets, or sheets at room temperature, and is a low-fluidity or non-fluid solid at 25°C. Here, "non-fluidity" means that it does not deform and / or flow in the absence of an external force. Preferably, the present cured silicone composition, when molded into pellets, tablets, or the like, does not deform and / or flow at 25°C in the absence of an external force. Such non-fluidity 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 a certain load is applied to the composition. Being non-fluid at 25°C means that the composition has good shape retention at that temperature and has low surface tack, making it easy to handle even in an uncured state.

[0104] The softening point of the composition is preferably 100° C. or lower. This softening point refers to the temperature at which, when a 22 mm-high composition is pressed down on a hot plate with a load of 100 grams for 10 seconds, and the amount of deformation of the composition in the height direction is measured after the load is removed, the amount of deformation is 1 mm or more.

[0105] [Curable Hot-Melt Silicone Composition Sheet] The curable hot-melt silicone composition sheet obtained by the production method of the present invention is a curable silicone composition containing the above-mentioned components and has hot-melt properties. The curable hot-melt silicone composition sheet of the present invention can be used as a pressure-sensitive adhesive, sealant, and / or adhesive having heat-melt properties. 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 overmolding, compression molding, or press molding.

[0106] Specifically, after peeling the curable hot-melt silicone composition sheet obtained by the production method of the present invention from the release film, it is placed in the desired location on a semiconductor or the like and melted by heating to form a film adhesive layer on and between the adherends that takes advantage of its gap-filling properties for unevenness and gaps on the substrate, thereby temporarily fixing, positioning, and laminating the adherends together, and then curing the curable hot-melt silicone composition layer by irradiation with high-energy rays or heating to form a cured product of the curable silicone sheet between the adherends, thereby bonding the adherends. 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.

[0107] Because the curable silicone composition sheet has hot-melt properties, heating the sheet before final curing softens or fluidizes it, and even if there are irregularities or gaps on the adherend's surface, the irregularities or gaps can be filled in without leaving any gaps, forming an adhesive surface with the adherend. As a means for heating the curable hot-melt silicone composition sheet, for example, various types of thermostatic baths, hot plates, electromagnetic heating devices, heating rolls, etc. can be used. In order to more efficiently bond the adherend and the curable silicone composition sheet and heat the curable silicone composition, for example, an electric heating press, a diaphragm-type laminator, a roll laminator, etc. are preferably used.

[0108] [Method of Forming a Cured Product] As already mentioned, depending on the selection of component (B), the curable hot-melt silicone composition of the present invention can be designed as a photocurable composition when irradiated with high-energy rays, or as a thermosetting composition when heated.

[0109] When at least a portion of component (B) is (B1) a photoradical polymerization initiator, the curable silicone composition of the present invention can undergo a radical polymerization reaction to form a cured product by irradiating the composition of the present invention (or a semi-cured product thereof) with high-energy rays such as ultraviolet light.

[0110] Usable high-energy rays include ultraviolet rays, gamma rays, X-rays, α-rays, and electron beams. Particularly, ultraviolet rays, X-rays, and electron beams emitted from commercially available electron beam irradiation devices are mentioned. Among these, ultraviolet rays are preferred from the viewpoint of catalyst activation efficiency, and ultraviolet rays with wavelengths in the range of 280 to 380 nm are preferred from the viewpoint of industrial use. The irradiation dose varies depending on the type of high-energy ray-activated catalyst, but in the case of ultraviolet rays, the cumulative irradiation dose at a wavelength of 365 nm is 100 mJ / cm. ２ ~100 J / cm ２ It is preferable that the range is

[0111] Because the curing reaction does not require heating, curing can be achieved in a low temperature range (15 to 100°C), including room temperature (25°C). In the present embodiment, "low temperature" refers to, for example, 100°C or lower, specifically, a temperature range of 15 to 100°C, and temperatures of 80°C or lower are also selectable. When the reaction of the composition of the present invention (including semi-cured products) is allowed to proceed at a temperature range of 15 to 100°C, the composition may be left standing at approximately room temperature (a temperature range that can be reached without heating or cooling, particularly a temperature range of 20 to 25°C), cooled to 15°C or higher below room temperature, or heated to a temperature above room temperature but below 100°C. The time required for the curing reaction can be appropriately designed depending on the irradiation dose and temperature of high-energy rays such as ultraviolet rays. Furthermore, depending on process tolerance and necessity, heating above 100°C may be temporarily performed, or the curing reaction may be allowed to proceed simultaneously with compression bonding by thermocompression bonding, which involves heating and compression bonding simultaneously.

[0112] When at least a portion of component (B) contains a thermal radical polymerization initiator (B2), the curable silicone composition of the present invention can undergo a radical polymerization reaction to form a cured product by heating to 100° C. or higher. The heating temperature can be selected appropriately depending on the heat resistance of the substrate and the sealing process, etc., but if the substrate is highly heat-resistant, it is possible to heat at a high temperature of 150° C. or higher.

[0113] The cured product of the curable hot-melt silicone composition of the present invention is characterized by its excellent resistance to yellowing under conditions of high temperature, high humidity, or UV exposure. In other words, by using this composition, the cured product has a thickness of 200 μm and shows a b ＊ It is possible to obtain a cured product having a value of 2.0 or less, preferably 1.0 or less. In particular, with previously known active energy ray-curable hot-melt silicone compositions that can be cured at low temperatures (for example, the aforementioned Patent Document 4, etc.), the cured product has low yellowing resistance, making it difficult to apply to applications requiring transparency. However, the cured product of the present invention can be rapidly cured at low temperatures as needed, while also having excellent yellowing resistance and maintaining high transparency even when used under harsh conditions, and therefore has the advantage of being suitable for use in optical materials, including as a sealant for optical semiconductors. Furthermore, the composition of the present invention can also be suitably used in applications where a substrate with poor heat resistance is sealed with a transparent cured product.

[0114] [Uses of the Composition] The curable hot-melt silicone composition of the present invention has hot-melt properties, excellent handling and curing properties during melting (hot-melt), and excellent discoloration resistance at high temperatures in the cured product obtained by curing the composition. Therefore, it is useful for semiconductor components such as encapsulants for light-emitting / optical devices and light-reflecting materials, and for optical semiconductors containing the cured product. Furthermore, the cured product has excellent mechanical properties, making it suitable as an encapsulant for semiconductors; an encapsulant for power semiconductors such as SiC and GaN; and an adhesive, potting agent, protective agent, and coating agent for electrical and electronic applications. Furthermore, the curable hot-melt silicone composition of the present invention in sheet form is suitable as a material for sealing or adhering large-area substrates using press molding, compression molding, or a vacuum laminator. It is particularly suitable for use as an encapsulant for semiconductors that use overmolding during molding. Furthermore, sheets of the composition can be used as curable film adhesives or as a stress buffer layer between two substrates with different linear expansion coefficients.

[0115] Furthermore, the curable hot-melt silicone composition of the present invention, particularly a sheet-shaped curable hot-melt silicone composition, can be used for large-area sealing of semiconductor substrates (including wafers). Furthermore, sheets obtained by molding the curable hot-melt silicone composition of the present invention into a sheet can be used for die attach films, sealing of flexible devices, stress relief layers for bonding two different substrates, etc. In other words, the curable silicone composition of the present invention can be a sealant intended for single-sided sealing, or a sealant intended for double-sided sealing involving adhesion between two substrates, and has preferable properties suitable for these applications.

[0116] [Uses of the Cured Product] The uses of the cured product obtained by curing the curable silicone composition of the present invention are not particularly limited. The composition of the present invention has hot-melt properties, excellent curing properties, excellent moldability, and excellent mechanical properties, and the cured product thereof has excellent yellowing resistance and is able to maintain high transparency. 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 an encapsulant for semiconductor elements, IC chips, etc., or as an adhesive or bonding material for conductor devices.

[0117] There are no particular limitations on the type of semiconductor device that includes a component made from the cured product obtained by curing the curable silicone composition of the present invention, but since the composition of the present invention forms an optically transparent cured product, it is particularly suitable for use in applications that require light transmission. For example, it is suitable for use as a light-emitting semiconductor device, which is a light-emitting / optical device, an optical component for a display, or a component for a solar panel, and is particularly suitable as a sealant or adhesive component for use in these devices. Furthermore, because the cured product of the present invention has excellent yellowing resistance (resistance to discoloration) when exposed to high temperatures or ultraviolet light, it is particularly suitable for use as a sealant or adhesive component for electronic materials, where transparency and light and heat resistance are important.

[0118] [Method for encapsulating semiconductor or optical semiconductor devices] The curable hot-melt silicone composition of the present invention can be suitably used in a method for encapsulating semiconductor or optical semiconductor devices, comprising: step (E-1): bringing the curable hot-melt silicone composition of the present invention into close contact with part or all of a semiconductor device, optical semiconductor device, or a substrate that is a precursor thereof; and step (E-2): optionally irradiating with high-energy rays, followed by curing the uncured curable hot-melt silicone composition at room temperature or by heating.

[0119] As a preliminary step to step (E-1), the curable hot-melt silicone composition of the present invention is heated to cause it to flow, and the cured product is then used to fill any irregularities or voids in the substrate of a semiconductor device, optical semiconductor device, or precursor thereof, thereby encapsulating the semiconductor device or optical semiconductor device with a cured product that has excellent gap-filling properties between substrates.

[0120] The present invention will be explained in more detail below using examples and comparative examples, but the present invention is not limited to these examples. Furthermore, due to the nature of the semi-cured product of the present invention, high-energy radiation was not irradiated simultaneously during heat curing. (Measurement of Molecular Weight of Organopolysiloxane Component) Using a Waters gel permeation chromatography (GPC) and tetrahydrofuran (toluene) as a solvent, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) of the organopolysiloxane component of the organopolysiloxane resin, etc., were determined in terms of standard polystyrene.

[0121] Synthesis Example 1 A 1000 mL four-neck flask was charged with the following average formula: ３ SiO １／２ ) ４０．８１ (Me ２ ViSiO １／２ ) ６．４６ (SiO ２ ) ５２．７３ 333.0 g of a 60% xylene solution of MQ resin (vinyl content 2% by mass, hereafter referred to as Vi-MQ resin), 200.0 g of a polydimethylsiloxane capped with silanol groups at both ends and having a viscosity of 12,500 mPa·s, and 133.0 g of toluene were added and mixed. 5 g of 30% aqueous ammonia was added to the resulting mixture, which was then stirred at 40°C for 8 hours. The ammonia and water were then distilled off by refluxing the toluene at 120°C. The resulting reaction mixture was cooled to room temperature, and then mixed with 26.3 g of 3-(1,1,3,3-tetramethyldisiloxanyl)propyl methacrylate and 0.1 g of 4-methoxyphenol. To this mixture was added a toluene solution of platinum / 1,3-divinyltetramethyldisiloxane complex at 2 ppm (calculated as platinum mass), and the mixture was stirred for 4 hours while adjusting the temperature to 40°C to 50°C. Consumption of SiH was confirmed by IR spectroscopy, and it was determined that the average structure was the following formula: (Me ３ SiO １／２ ) ２０．３６ (Me ２ ViSiO １／２ ) ０．９０ (Me ２ ViR Ａ SiO １／２ ) ２．１９ (Me２ SiO) ５０．０５ (SiO ２ ) ２６．５０ As a result, 692 g of a solution of a methacryl-functional organopolysiloxane resin represented by the formula:

[0122] Synthesis Example 2: 333.0 g of a 60% xylene solution of the Vi-MQ resin (vinyl content: 2% by mass), 200.0 g of a polydimethylsiloxane capped with silanol groups at both ends and having a viscosity of 2,300 mPa·s, and 133.0 g of toluene were mixed into a 1000 mL four-neck flask. 5 g of 30% aqueous ammonia was added to the resulting mixture, which was then stirred at 40°C for 8 hours. The ammonia and water were then distilled off by refluxing the toluene at 120°C. The resulting reaction mixture was cooled to room temperature, and then mixed with 26.3 g of 3-(1,1,3,3-tetramethyldisiloxanyl)propyl methacrylate and 0.1 g of 4-methoxyphenol. To this mixture was added a toluene solution of platinum / 1,3-divinyltetramethyldisiloxane complex at 2 ppm (calculated as platinum mass), and the mixture was stirred for 4 hours while adjusting the temperature to 40°C to 50°C. Consumption of SiH was confirmed by IR spectroscopy, and it was determined that the average structure was the following formula: (Me ３ SiO １／２ ) ２０．２４ (Me ２ ViSiO １／２ ) ０．８８ (Me ２ ViR Ａ SiO １／２ ) ２．１６ (Me ２ SiO) ５０．４６ (SiO ２ ) ２６．２５ (In the formula R Ａ is the monovalent substituent described in Synthesis Example 1), 692 g of a solution of a methacryl-functional organopolysiloxane resin represented by the formula:

[0123] Synthesis Example 3 A 1000 mL four-neck flask was charged with the following average formula: (Me ３ SiO １／２ ) ４５．０ (SiO ２ ) ５５．０220.0 g of a 60% xylene solution of MQ resin represented by the formula (I), 220.0 g of the above 60% solution of Vi-MQ resin, 100.0 g of a polydimethylsiloxane capped with silanol groups at both ends and having a viscosity of 12,500 mPa·s, and 88.0 g of toluene were mixed together. 30% aqueous ammonia (5 g) was added to the resulting mixture and stirred at 80°C for 7 hours. After that, nitrogen gas was blown into the flask at 120°C to distill off the ammonia and water. After cooling the reaction mixture to 60°C, 15.0 g of hexamethyldisilazane and 0.3 g of trifluoroacetic acid were added to the mixture and reacted at the same temperature for 3 hours. Excess hexamethyldisilazane was distilled off at 120°C. After cooling the reaction mixture to room temperature, the inorganic salts were filtered off. To the resulting reaction mixture, 26.0 g of 3-(1,1,3,3-tetramethyldisiloxanyl)propyl methacrylate and 0.1 g of 4-methoxyphenol were added. To this mixture, 2 ppm (calculated as platinum mass) of a toluene solution of platinum / 1,3-divinyltetramethyldisiloxane complex was added, and the mixture was stirred for 4 hours while adjusting the temperature to 40°C to 50°C. Consumption of SiH was confirmed by IR spectroscopy, and it was determined that the average structure was the following formula: (Me ３ SiO １／２ ) ３３．３３ (Me ２ ViSiO １／２ ) ０．６５ (Me ２ ViR Ａ SiO １／２ ) １．５２ (Me ２ SiO) ２６．２ (SiO ２ ) ３８．２６ (In the formula R Ａ is a monovalent substituent represented by formula I above), 555 g of a solution of a methacryl-functional organopolysiloxane resin.

[0124] Synthesis Example 4: 166.7 g of a 60% xylene solution of Vi-MQ resin, 44.7 g of polydimethylsiloxane capped at both ends with dimethylhydrogensiloxy groups (hydrogen content: 0.01% by mass), and 30.0 g of toluene were added to a 1000 mL four-neck flask and mixed. To this mixture was added a toluene solution of platinum / 1,3-divinyltetramethyldisiloxane complex in an amount of 2 ppm (calculated as platinum mass), and the mixture was stirred at 90°C for 3 hours. After confirming the consumption of SiH by IR spectroscopy, the resulting reaction mixture was cooled to room temperature, and 18.2 g of 3-(1,1,3,3-tetramethyldisiloxanyl)propyl methacrylate and 0.1 g of 4-methoxyphenol were added. The mixture was stirred for 4 hours while adjusting the temperature to 40°C to 50°C. Consumption of SiH was confirmed by IR spectroscopy, and it was determined that the average structure was of the following formula: (In the formula R Ａ is the monovalent substituent described in Synthesis Example 1), 259.8 g of a solution of a methacryl-functional organopolysiloxane resin.

[0125] A1: Organopolysiloxane shown in Synthesis Example (1) A2: Organopolysiloxane shown in Synthesis Example (2) A3: Organopolysiloxane shown in Synthesis Example (3) B1: 2,4,6-trimethylbenzoyldiphenylphosphine oxide (product name Omnirad TPO, manufactured by IGM Resins) B2: 2-hydroxy-2-methylpropiophenone (manufactured by Tokyo Chemical Industry Co., Ltd.) C1: (CH3)3SiO 1 / 2 Siloxane units (M units) represented by R A (CH3) ２ SiO 1 / 2 The siloxane unit (M ＲＡ Unit: R Ａ is the monovalent substituent described in Synthesis Example 1) and SiO ４／２ The weight average molecular weight (Mw) measured by GPC using toluene as a solvent is 19,000 g / mol, and the average composition is M ０．５２ M ＲＡ ０．０１ Q ０．４７ Organopolysiloxane resin D1: (CH3) 3SiO1 / 2 Siloxane units (M units) represented by the formula: and SiO ４／２ The weight average molecular weight (Mw) measured by GPC using toluene as a solvent is 18,000 g / mol, and the average composition is M ０．４９ Q ０．５１ Organopolysiloxane resin D2 represented by (CH3)3SiO 1 / 2 Siloxane units (M units) represented by (CH2=CH)(CH3) ２ SiO 1 / 2 The siloxane unit (M Vi units) and SiO ４／２ The weight average molecular weight (Mw) measured by GPC using toluene as a solvent is 18,500 g / mol, and the average composition is M ０．４２ M Vi ０．０６ Q ０．５２ E1: Polydimethylsiloxane raw rubber having vinyl functionality at both molecular chain terminals / side chains and a plasticity of 120 (vinyl content: 0.84% ​​by mass); E2: Polydimethylsiloxane raw rubber blocked at both terminals with trimethylsiloxy groups and a plasticity of 170; E3: Polydimethylsiloxane having dimethylvinylsiloxy functionality at both terminals and a viscosity of 39,000 mPa·s (vinyl content: 0.09% by mass); F1: Toluene

[0126] (Examples 1 to 7, Comparative Examples 1 to 3) Examples and comparative examples of the present invention are described below.

[0127] [Preparation of active energy ray curable reaction type silicone composition] Using the components shown in Table 1, a toluene solution with a solids concentration of 70% of the composition shown in each Example (Examples 1 to 7) and Comparative Example 1 was prepared. Note that all percentages in Table 1 are by mass. Comparative Example 2: 42 parts by mass of component D1, 23 parts by mass of component D2, 30 parts by mass of component E3, average structural formula: (Me ２ HSiO １／２ ) ０．３ (PhSiO ３／２ ) ０．７A toluene solution of a composition having a solids concentration of 70% was prepared, the composition comprising 3 parts by mass of an organohydrogenpolysiloxane represented by the formula: Me and 0.0020 parts by mass of a (methylcyclopentadienyl)trimethylplatinum complex. ３ SiO(Me ２ SiO) ２９ [Me(HSC ３ H ６ )SiO] ３ SiMe ３ A toluene solution containing 12.5 parts by mass of a composition containing a 3-mercaptopropyl group represented by the following formula was prepared, the solids concentration of which was 70%.

[0128] [Preparation of an active energy ray-curable hot-melt silicone composition film] The above solution was applied to a release-treated PET film (product name FSC-6, manufactured by NIPPA Corporation) so that the thickness after heat drying would be 200 μm, and the film was dried for 10 minutes at 100° C. After cooling to room temperature, the release-treated surface of the PET film was placed over the composition, thereby producing an active energy ray-curable hot-melt silicone film laminate at room temperature.

[0129] [Softening Properties of Uncured Film] A piece of uncured film cut to a diameter of 8 mm was attached to a measuring jig of the same diameter. Using an Anton Paar MCR302, the sample was heated from 25°C to 80°C at a rate of 3°C / min, and the complex viscosity was measured. The complex viscosities at 25°C and 80°C were recorded. The results are shown in Table 1.

[0130] [Preparation of Test Piece for Evaluating Optical Properties] The PET film was peeled off from the hot melt film laminate, and the laminate was sandwiched between two sheets of alkali-free glass (75 mm long x 50 mm wide x 1.1 mm thick, Corning Eagle XG) to prevent air bubbles from entering. A laminate was prepared by irradiating the laminate with a UV-LED ultraviolet irradiation device (JATEC Corporation) at an ultraviolet irradiation dose (illuminance) of 4,000 mJ / cm as an integrated light amount. ２The hot melt layer was cured by irradiating it with ultraviolet light having a wavelength of 405 nm so that the test piece was obtained. ＊ Furthermore, in order to evaluate the yellowing resistance of the cured product, for Examples 1, 3, Comparative Examples 2 and 3, the test pieces were aged at 150°C, 85°C / 85% relative humidity and in a QUV device for 500 hours, and the b ＊ For each experimental example, the presence or absence of hardening, the presence or absence of cloudiness, and the b value of the test piece were also recorded. ＊ The results regarding the values ​​are shown in Tables 1 to 3.

[0131] Table 1. Compositions, hot melt properties, UV curing properties, etc. of Examples 1 to 7 and Comparative Example 1 Table 2: UV curability and presence or absence of cloudiness after irradiation in Comparative Examples 1 to 3 Table 3. b of hardened test pieces according to the examples and comparative examples ＊ Value (yellowing)

[0132] As shown in Tables 1 and 2, the compositions containing organopolysiloxanes having a resin-linear structure according to the present invention in Examples 1 to 7 were non-flowable at room temperature and were capable of achieving low viscosity (hot-melt properties) suitable for encapsulation at 80°C. They also exhibited favorable curing properties at room temperature, yielding cured products with excellent transparency. Furthermore, the resulting cured products (i.e., test specimens according to the examples) had superior yellowing resistance compared to the thiol-ene curing composition shown in Comparative Example 3, which can be rapidly cured at room temperature. Based on these properties, it is expected that the curable hot-melt silicone compositions according to the present invention, when used in the manufacturing process of displays or electronic devices containing substrates with poor stability at high temperatures, will have excellent encapsulation properties at 80°C, be cured at room temperature upon irradiation with high-energy rays, and yield cured products with excellent appearance stability and transparency. On the other hand, as shown in Table 2, when a siloxane without a resin-linear structure was used, as in Comparative Example 1, the curing properties were insufficient and the composition was not suitable for encapsulation. Furthermore, as shown in Tables 2 and 3, the composition of Comparative Example 2 had high yellowing resistance, but its inability to rapidly cure at room temperature may limit its applications.

Claims

1. (A) R Ａ a R Ｂ （３－ａ） SiO １／２ (R Ａ is a silicon atom-bonded functional group containing an acrylic group or a methacrylic group, R Ｂ is a monovalent organic group excluding R Ａ and a is a number in the range of 1 to 3), a siloxane unit (M ＲＡ unit) and SiO ４／２ A resinous organosiloxane block X having an acrylic group or a methacrylic group, represented by a siloxane unit (Q unit), and {R Ｃ ２ SiO ２ / ２}[ β (R Ｃ is a monovalent organic group and β is a number of 2 or more), a chain organosiloxane block Y having a siloxane unit represented by the formula, and having at least two of the above silicon atom-bonded functional groups (R Ａ ) in the molecule, 100 parts by mass of a resin-linear structure-containing organopolysiloxane block copolymer, and​ A curable hot-melt silicone composition containing 0.1 to 10 parts by mass of (B) a radical polymerization initiator.

2. The curable hot-melt silicone composition according to claim 1, wherein the component (A) is a resin-linear structure-containing organopolysiloxane block copolymer having a structure in which the silicon atoms constituting the resinous organosiloxane block X and the chain-like organosiloxane block Y are linked by a siloxane bond or a silaalkylene bond.

3.

4. The component (A) is R Ｂ ３ SiO １／２ (R Ｂ is a monovalent organic group excluding the above R Ａ ), a siloxane unit (M unit) represented by, containing the above M ＲＡ unit and Q unit, and the sum of the amount of substance of the M unit and M ＲＡ unit per 1 mol of the Q unit is in the range of 0.5 to 2.0 mol, and the curable hot-melt silicone composition according to claim 1, characterized by containing a resinous organosiloxane block X.

5. Component (A) consists of a resinous organosiloxane block X and a chain organosiloxane block Y having siloxane units represented by {R Ｃ ２ SiO ２ / ２} β１ (wherein R Ｃ is a monovalent organic group and β1 is a number in the range of 5 to 5000), and the curable hot melt silicone composition according to claim 1, characterized in that the block X and the block Y have a structure linked by a siloxane bond between silicon atoms.

6. The component (A) contains a resinous organosiloxane block X in which the amount of substance of the M unit is in the range of 0.02 to 0.50 mol per 1 mol of the Q unit ＲＡ The curable hot-melt silicone composition according to claim 1, characterized in that it contains a resinous organosiloxane block X in which the amount of substance of the M unit is in the range of 0.02 to 0.50 mol per 1 mol of the Q unit. General formula (1): The silicon atom-bonded functional group R in component (A) Ａ The curable hot melt silicone composition according to claim 1, wherein the functional group is represented by the following general formula (1).

7. 【Chemical 1】 [In the formula, R １ each independently represents a hydrogen atom, a methyl group, or a phenyl group; R ２ each independently represents an alkyl group or an aryl group. １ Ha -O(CH ２ ) ｍ - (m is a number ranging from 0 to 3). ２ is bonded to a silicon atom constituting the main chain of polysiloxane, where -C is * ｎ H ２ｎ - (n is a number ranging from 2 to 10). The curable hot-melt silicone composition according to claim 1, wherein at least a part of the component (B) is (B1) a photo radical polymerization initiator and has photocurability by irradiation with high energy rays.

8. The curable hot-melt silicone composition according to claim 1, comprising Furthermore, (C) R in the molecule Ｂ ３ SiO １／２ and R Ａ ａ R Ｂ （３－ａ） SiO １／２ (wherein a represents an integer of 1 to 3, and R Ｂ each independently represents a monovalent organic group excluding R Ａ ) an organopolysiloxane resin containing M units and Q units represented by the range of the molar ratio of M units to Q units of 0.5 to 2.0, 0.1 to 50 parts by mass

9. The curable hot-melt silicone composition according to claim 1, containing Furthermore, (D) R in the molecule Ｂ ３ SiO １／２ (wherein R independently represents a monovalent organic group excluding R Ａ ), an organopolysiloxane resin containing M units and Q units represented by the formula, and the ratio of M units to Q units is in the range of 0.5 to 2.0, in an amount of 0.1 to 200 parts by mass

10. The curable hot-melt silicone composition according to claim 1, further containing one or more selected from (E) polydimethylsiloxane which may optionally have an alkenyl group and (F) an organic solvent.

11. The curable hot-melt silicone composition according to claim 1, wherein the complex viscosity of the composition before curing at 80°C is 10,000 Pa·s or less.

12. The curable hot-melt silicone composition according to claim 1, formed into a sheet or film.

13. A sheet or film of the curable hot-melt silicone composition according to claim 12, and A sheet or film-like substrate having a release surface facing the sheet or film of the curable hot-melt silicone composition, which is attached to one or both surfaces of the sheet or film of the curable hot-melt silicone composition, and the sheet or film of the curable hot-melt silicone composition is peelable from the sheet or film-like substrate having the release surface, a peelable laminate.

14. A cured product obtained by curing the curable hot-melt silicone composition according to any one of claims 1 to 12.

15. A cured product obtained by curing the photocurable hot-melt silicone composition according to claim 7 by irradiating it with high energy rays.

16. ​ A semiconductor device or an optoelectronic semiconductor device having the cured product according to claim 14 or claim 15.

17. Step (I): A step of applying the curable hot-melt silicone composition according to any one of claims 1 to 11 onto a substrate. Step (II): A step of heating and drying the composition applied in step (I) to obtain a composition formed into a sheet or film. A method for producing a sheet or film of the curable hot-melt silicone composition according to claim 12, comprising the above steps.

18. Step (E-I): A step of bringing the curable hot-melt silicone composition according to any one of claims 1 to 12 into close contact with a semiconductor device, an optoelectronic semiconductor device, or a part or all of a substrate that is a precursor thereof. Step (E-2): A method for encapsulating a semiconductor device or an optoelectronic semiconductor device, which includes a step of curing the uncured curable hot-melt silicone composition by irradiating with high-energy rays optionally and then heating at room temperature or by heating.

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