Addition-curable organopolysiloxane composition
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- SHIN ETSU CHEMICAL CO LTD
- Filing Date
- 2025-01-24
- Publication Date
- 2026-08-05
Smart Images
Figure 2026126530000001 
Figure 2026126530000002 
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Abstract
Description
Technical Field
[0001] The present invention relates to an addition-curable organopolysiloxane composition.
Background Art
[0002] Conventionally, polysiloxanes capable of addition crosslinking by hydrosilylation are known. However, the inventors' studies have revealed that addition-crosslinkable polysiloxanes containing alkylsilsesquioxane units are difficult to synthesize because the hydrolysis-condensation reaction of the monomer, alkyltrialkoxysilane compounds, is very fast and gelation occurs.
[0003] Patent Document 1 discloses a method of performing hydrolysis using a silanol group generated by hydrolysis of an alkoxysilyl group as a catalyst in order to slow down the rate of hydrolysis-condensation when hydrolyzing an alkoxysilane mixture containing methyltrimethoxysilane. Further, this document discloses a method of synthesizing an organopolysiloxane without gelation by adding a carboxylic acid or a carboxylate and distilling off methanol after performing hydrolysis-condensation. However, although the method of Patent Document 1 is suitable for the synthesis of low molecular weight organopolysiloxanes, since the polymerization is slow, severe reaction conditions are required to obtain a relatively high molecular weight organopolysiloxane, so the reaction is difficult to control, and there are problems such as gelation, reduction in reproducibility, and deterioration in workability due to generation of microgels.
[0004] In order to solve these problems, Patent Document 2 discloses a method for efficiently producing an addition-crosslinkable polysiloxane having an alkylsilsesquioxane unit. However, the organopolysiloxane obtained by the formulation of Patent Document 2 has problems such as a hard cured film being obtained, but having no flexibility or softness and being inferior in moldability.
Prior Art Documents
Patent Documents
[0005] [Patent Document 1] Patent No. 2712817 [Patent Document 2] Japanese Patent Publication No. 2020-111657 [Overview of the project] [Problems that the invention aims to solve]
[0006] The present invention has been made in view of the above circumstances, and aims to provide an addition-curing silicone composition having organosilsesquioxane units and exhibiting excellent flexibility and moldability. [Means for solving the problem]
[0007] As a result of diligent research to achieve the above objective, the present inventors have found that a certain polysiloxane having organosilsesquioxane units that can be crosslinked is suitable as a binder component or coating material for heat-resistant paints, etc., because it provides a cured product with excellent heat resistance and curability when heated. Furthermore, they have found that by incorporating a certain linear organopolysiloxane, flexibility and pliability can be imparted to the polysiloxane, allowing for easy molding, thus completing the present invention.
[0008] In other words, the present invention is 1. (A) Polysiloxane resin represented by the following formula (1): 100 parts by mass [ka] [In the formula, R 1 Each of these independently represents a monovalent hydrocarbon group with 1 to 12 carbon atoms that does not contain an aliphatic unsaturated bond, and R 2 Each of these independently represents a hydrogen atom or an alkenyl group with 2 to 12 carbon atoms (however, R 2 (The proportion of hydrogen atoms in the total number of atoms is 10-90 mol%), R 3each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and a, b, c, d, e, f, and g are numbers satisfying 0 ≦ a ≦ 0.6, 0.2 ≦ b ≦ 0.9, 0 ≦ c ≦ 0.8, 0 ≦ d ≦ 0.6, 0 ≦ e ≦ 0.8, 0 ≦ f ≦ 0.6, 0 ≦ g ≦ 0.8, and 0.1 ≦ (c + e + g) ≦ 0.8 and a + b + c + d + e + f + g = 1, and h is a number satisfying 0 ≦ h ≦ 1. (B) Linear polysiloxane represented by the following formula (2): 10 to 300 parts by mass,
Chemical formula
[0009] The composition of the present invention, which contains an addition-crosslinkable polysiloxane having organosilsesquioxane units, provides a cured product with excellent heat resistance upon heating, and can therefore be suitably used as a binder component in heat-resistant paints and heat-resistant resins, as well as for coatings on building materials and molded articles, and as a coating material and sealing material for electronic components. Furthermore, the polysiloxane of the present invention is excellent in flexibility and pliability, making it easy to mold and process, and allowing for its application in a variety of uses. [Modes for carrying out the invention]
[0010] The present invention will be described in detail below. [1] Addition-curable organopolysiloxane composition The addition-curable organopolysiloxane composition of the present invention contains (A) an organopolysiloxane resin, (B) a linear organopolysiloxane, and (C) a platinum group metal catalyst.
[0011] [Component (A)] Component (A) is a polysiloxane resin represented by the following formula (1), having an alkenyl group bonded to a silicon atom and a hydrogen atom (Si-H group) bonded to a silicon atom, and is a component that imparts hardness to the resulting cured product by forming crosslinks with other components (A) and / or with component (B) described later through a hydrosilylation reaction.
[0012] [ka]
[0013] In equation (1), R1 Each of these independently represents a monovalent hydrocarbon group having 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, and more preferably 1 to 6 carbon atoms, that does not contain an aliphatic unsaturated bond. R 1 The monovalent hydrocarbon group having 1 to 12 carbon atoms can be linear, branched, or cyclic. Specific examples include linear or branched alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, i-butyl, tert-butyl, neopentyl, n-hexyl, n-heptyl, and n-octyl groups; cycloalkyl groups such as cyclopentyl and cyclohexyl groups; unsubstituted aryl groups such as phenyl and naphthyl groups; alkylaryl groups such as tolyl, xylyl, ethylphenyl, propylphenyl, and butylphenyl groups; and aralkyl groups such as benzyl and phenylethyl groups. Among these, R 1 The group is preferably a methyl group or a phenyl group, and particularly preferably a methyl group.
[0014] R 2 Each of these is independently a hydrogen atom or an alkenyl group having 2 to 12 carbon atoms. R 2 The alkenyl group having 2 to 12 carbon atoms may be linear, branched, or cyclic. Specific examples include vinyl, 1-propenyl, allyl(2-propenyl), hexenyl, octenyl, cyclopentenyl, and cyclohexenyl groups, with vinyl being preferred among these. Also, R 2 The proportion of hydrogen atoms in the total number of atoms is 10-90%, preferably 30-70%. If the proportion of hydrogen atoms is less than 10% or more than 90%, curing failure may occur, and the hardness of the cured product may decrease significantly.
[0015] R 3 Each of these is independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. R 3The alkyl group having 1 to 4 carbon atoms can be linear, branched, or cyclic, and specific examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, i-butyl, tert-butyl, and among them R 3 Hydrogen atoms, methyl groups, and ethyl groups are preferred as the elements.
[0016] In equation (1), a is a number that satisfies 0 ≤ a ≤ 0.6, but from the viewpoint of crack suppression effect, a number that satisfies 0 ≤ a ≤ 0.3 is preferred, and 0 is more preferred. b is a number that satisfies 0.2 ≤ b ≤ 0.9, but from the viewpoint of scratch resistance of the resulting cured product, a number that satisfies 0.2 ≤ b ≤ 0.7 is preferred, and a number that satisfies 0.3 ≤ b ≤ 0.6 is preferred. c is a number satisfying 0 ≤ c ≤ 0.7, but from the viewpoint of the hardness and flexibility of the resulting cured product, a number satisfying 0.1 ≤ c ≤ 0.4 is preferred, and 0 is more preferred. d is a number that satisfies 0 ≤ d ≤ 0.6, but from the viewpoint of the hardness of the resulting cured product, a number that satisfies 0 ≤ d ≤ 0.5 is preferred, and a number that satisfies 0 ≤ d ≤ 0.4 is more preferred. e is a number that satisfies 0 ≤ e ≤ 0.7, but from the viewpoint of the hardness of the resulting cured product, a number that satisfies 0.1 ≤ e ≤ 0.5 is preferred, and a number that satisfies 0.1 ≤ e ≤ 0.3 is more preferred. f is a number that satisfies 0 ≤ f ≤ 0.6, but from the viewpoint of the heat stability and crack resistance of the resulting cured product, a number that satisfies 0.1 ≤ f ≤ 0.4 is preferred, and a number that satisfies 0.1 ≤ f ≤ 0.2 is more preferred. g is a number satisfying 0 ≤ g ≤ 0.7, but from the viewpoint of the hardness of the resulting cured product and the stability of the composition, a number satisfying 0 ≤ g ≤ 0.4 is preferred, and 0 is more preferred. Note that a, b, c, d, e, f, and g are numbers that satisfy a+b+c+d+e+f+g=1. Furthermore, c+e+g is a number that satisfies 0.1 ≤ (c+e+g) ≤ 0.8, but it is preferable that it satisfies 0.1 ≤ (c+e+g) ≤ 0.5, and more preferably that it satisfies 0.1 ≤ (c+e+g) ≤ 0.3. h is a number satisfying 0 ≤ h ≤ 1, but from the viewpoint of the curability of the composition and the crack resistance of the resulting cured product, a number satisfying 0 ≤ h ≤ 0.2 is preferred, and a number satisfying 0 ≤ h ≤ 0.1 is more preferred.
[0017] (A) Specific examples of components include, but are not limited to, those listed below. Note that Me represents a methyl group, Ph represents a phenyl group, and Vi represents a vinyl group (the same applies hereafter). (MeSiO 3 / 2 ) 0.5 (MeViSiO 2 / 2 ) 0.15 (MeHSiO 2 / 2 ) 0.15 (Me3SiO 1 / 2 ) 0.2 (HO 1 / 2 ) 0.02 (PhSiO 3 / 2 ) 0.5 (MeViSiO 2 / 2 ) 0.15 (MeHSiO 2 / 2 ) 0.15 (Me3SiO 1 / 2 ) 0.2 (HO 1 / 2 ) 0.02 (SiO 4 / 2 ) 0.1 (MeSiO 3 / 2 ) 0.43 (MeViSiO 2 / 2 ) 0.15 (MeHSiO 2 / 2 ) 0.15 (Me3SiO 1 / 2 ) 0.17 (HO 1 / 2 ) 0.02
[0018] (A) The alkenyl group content in component is preferably 0.05 to 0.6 moles / 100g, and more preferably 0.1 to 0.3 moles / 100g, from the viewpoint of the curability of the composition. For example, the method used in the later examples can be used as the measurement conditions for the alkenyl group content.
[0019] The weight-average molecular weight (Mw) of the above organopolysiloxane in gel permeation chromatography (GPC), calculated on a polystyrene basis, is preferably 1,000 to 50,000, and more preferably 5,000 to 20,000. If the weight-average molecular weight is 1,000 or higher, it exhibits excellent film formation, storage stability, and coating properties, and if it is 50,000 or lower, there is no risk of unevenness or uneven coating during application. Furthermore, the measurement conditions for GPC can be, for example, the method used in the later examples.
[0020] Note that component (A) may be a single composition or a mixture of multiple polysiloxane resins with different compositions.
[0021] Component (A) can be produced by known methods. For example, it can be synthesized according to the procedure described in Japanese Patent Application Publication No. 2020-111657, and is obtained by hydrolyzing and condensing a chlorosilane and / or alkoxysilane, or a partially hydrolyzed condensate thereof, which can form siloxane units constituting the polysiloxane resin represented by formula (1) above by hydrolysis and condensation, in an organic solvent capable of dissolving the raw material silane compound and the resulting polysiloxane resin under acidic conditions. To obtain a polysiloxane with a desired weight-average molecular weight, this can be done by adjusting the monomer mixing ratio, reaction temperature and time, and the amounts of water and organic solvent used. The polysiloxane resin thus produced is then subjected to removal of organic solvents as needed, and precipitates are removed by filtration.
[0022] [(B) component] Component (B) is a linear polysiloxane represented by the following formula (2), which forms crosslinks with the alkenyl groups and / or Si-H groups bonded to the silicon atoms of component (A) through a hydrosilylation reaction, thereby imparting flexibility to the cured product.
[0023] [ka]
[0024] In equation (2), R4 Each of these is independently a monovalent hydrocarbon group having 1 to 12 carbon atoms, preferably 1 to 6 carbon atoms, and more preferably 1 to 3 carbon atoms, that does not contain an aliphatic unsaturated bond. R 4 The monovalent hydrocarbon group having 1 to 12 carbon atoms can be linear, branched, or cyclic. Specific examples include linear or branched alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, i-butyl, tert-butyl, neopentyl, n-hexyl, n-heptyl, and n-octyl groups; cycloalkyl groups such as cyclopentyl and cyclohexyl groups; aryl groups such as phenyl and naphthyl groups; alkylaryl groups such as tolyl, xylyl, ethylphenyl, propylphenyl, and butylphenyl groups; and aralkyl groups such as benzyl and phenylethyl groups. Preferably, the alkyl group has 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms, with the methyl group being particularly preferred.
[0025] R 5 Each of these is independently a hydrogen atom or an alkenyl group having 2 to 12 carbon atoms. R 5 The alkenyl group with 2 to 12 carbon atoms can be linear, branched, or cyclic. Specific examples include vinyl, 1-propenyl, allyl(2-propenyl), hexenyl, octenyl, cyclopentenyl, and cyclohexenyl groups. Among these, R 5 A hydrogen atom or a vinyl group is preferred.
[0026] R 6 Each of these is independently a monovalent hydrocarbon group having 1 to 12 carbon atoms, preferably 1 to 6 carbon atoms, and more preferably 1 to 3 carbon atoms. R 6The monovalent hydrocarbon group having 1 to 12 carbon atoms can be linear, branched, or cyclic. Specific examples include linear or branched alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, i-butyl, tert-butyl, neopentyl, n-hexyl, n-heptyl, and n-octyl groups; cycloalkyl groups such as cyclopentyl and cyclohexyl groups; aryl groups such as phenyl and naphthyl groups; alkylaryl groups such as tolyl, xylyl, ethylphenyl, propylphenyl, and butylphenyl groups; aralkyl groups such as benzyl and phenylethyl groups; vinyl, 1-propenyl, allyl(2-propenyl), hexenyl, octenyl, cyclopentenyl, and cyclohexenyl groups. Among these, R 6 A methyl group or a vinyl group is preferred.
[0027] n is an integer between 0 and 1,200, and is preferably an integer between 10 and 1,000, considering the balance between the hardness and flexibility of the cured product.
[0028] (B) Specific examples of component (B) include, but are not limited to, those listed below. HMe2SiO-(Me2SiO) 10 -SiMe2H HMe2SiO-(Me2SiO) 20 -SiMe2H HMe2SiO-(Me2SiO) 40 -SiMe2H HMe2SiO-(Me2SiO) 400 -SiMe2H HMe2SiO-(Me2SiO) 1000 -SiMe2H ViMe2SiO-(Me2SiO) 10 -SiMe2Vi ViMe2SiO-(Me2SiO) 20 -SiMe2Vi ViMe2SiO-(Me2SiO) 40 -SiMe2Vi ViMe2SiO-(Me2SiO) 400 -SiMe2Vi ViMe2SiO-(Me2SiO)1000 -SiMe2Vi Vi3SiO-(Me2SiO) 10 -SiVi3 Vi3SiO-(Me2SiO) 20 -SiVi3 Vi3SiO-(Me2SiO) 40 -SiVi3 Vi3SiO-(Me2SiO) 400 -SiVi3 Vi3SiO-(Me2SiO) 1000 -SiVi3
[0029] The amount of component (B) is in the range of 10 to 300 parts by mass, preferably 25 to 250 parts by mass, and more preferably 40 to 200 parts by mass, per 100 parts by mass of component (A). If the amount of component (B) is less than the lower limit, the flexibility may be poor, and if it exceeds the upper limit, the hardness may be insufficient. Furthermore, component (B) may be used alone or in combination of two or more types.
[0030] From the viewpoint of the reactivity of the composition, the number of hydrogen atoms bonded to silicon atoms in the composition is preferably 0.8 to 2.0 per alkenyl group bonded to silicon atoms in the composition, and more preferably 1.0 to 1.7. Furthermore, the ratio of the number of hydrogen atoms bonded to silicon atoms in the composition to the number of alkenyl groups bonded to silicon atoms can be determined by, for example, the method used in later examples.
[0031] [(C) component] Component (C) is a platinum group metal catalyst, and any platinum group metal catalyst that promotes the addition reaction (hydrosilylation reaction) of organopolysiloxanes is acceptable. Platinum group metal catalysts that are conventionally known and used in hydrosilylation reactions can be used. Examples include platinum-based, palladium-based, and rhodium-based catalysts, but platinum-based catalysts, which are relatively easy to obtain, are preferred. Examples include elemental platinum, platinum black, chlorplatinic acid, chlorplatinic acid-olefin complexes, chlorplatinic acid-divinyltetramethyldisiloxane complexes, chlorplatinic acid-alcohol coordination compounds, platinum diketone complexes, platinum-olefin complexes, platinum-alcohol complexes, and platinum coordination compounds. Furthermore, the platinum group metal catalyst may be used alone or in combination of two or more types.
[0032] The amount of component (C) should be an effective amount as a catalyst, that is, an effective amount necessary to promote the hydrosilylation reaction and cure the composition of the present invention. Preferably, the amount of catalyst is 0.1 to 500 ppm, more preferably 1 to 300 ppm, based on the mass of platinum group metal atoms relative to the mass of component (A). If the amount of catalyst is above the lower limit, the catalytic effect is reliably obtained, and if it is below the upper limit, the catalytic effect increases in proportion to the amount added, making it economical.
[0033] [Other ingredients] In addition to the components (A) to (C) above, the addition-curable silicone composition of the present invention may contain any other components as long as they do not impair the effects of the present invention. For example, the addition-curable silicone composition of the present invention may contain a reaction control agent to suppress the progression of the hydrosilylation reaction in order to extend the shelf life and pot life. The reaction control agent can be a conventionally known reaction control agent used in addition-curing silicone compositions, such as acetylene compounds like ethynylmethyldecylcarbinol, 1-ethynyl-1-cyclohexanol, and 3,5-dimethyl-1-hexyne-3-ol; various nitrogen compounds like tributylamine, tetramethylethylenediamine, and benzotriazole; organophosphorus compounds like triphenylphosphine; oxime compounds; and organochloro compounds.
[0034] When using a reaction control agent, the amount to be added is preferably 0.01 to 2.0 parts by mass, more preferably 0.01 to 0.1 parts by mass, per 100 parts by mass of component (A). Within this range, the reaction control effect is sufficiently exhibited. Furthermore, the reaction control agent may be diluted with an organopolysiloxane or toluene, etc., to improve its dispersibility in the addition-curable silicone composition.
[0035] The addition-curable silicone composition of the present invention may contain a heat-resistant additive to improve heat resistance. Examples of heat-resistant additives include cerium oxide, iron oxide, halogen compounds, and hindered amine compounds. When using a heat-resistant additive, the amount added is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, per 100 parts by mass of component (A).
[0036] The addition-curable silicone composition of the present invention may contain a diluent solvent to reduce viscosity. The diluent is not particularly limited as long as it can dissolve or disperse the organopolysiloxane of the present invention. Specific examples include aromatic hydrocarbons such as toluene and xylene; hydrocarbons such as hexane and octane; ketones such as methyl ethyl ketone and methyl isobutyl ketone; esters such as ethyl acetate and isobutyl acetate; and alcohols such as methanol, ethanol, isopropanol, butanol, isobutanol, and t-butanol.
[0037] The addition-curable silicone composition of the present invention may contain an adhesion aid to impart adhesion to a substrate. As adhesive aids, organosilicon compounds such as silanes and siloxanes containing functional groups that impart adhesion, non-silicone organic compounds, etc., are used. Specific examples of functional groups that impart adhesion include vinyl groups bonded to silicon atoms, alkenyl groups such as allyl groups, epoxy groups bonded to silicon atoms via hydrogen or carbon atoms (e.g., γ-glycidoxypropyl group, β-(3,4-epoxycyclohexyl)ethyl group, etc.), acryloxy groups (e.g., γ-acryloxypropyl group, etc.), methacryloxy groups (e.g., γ-methacryloxypropyl group, etc.), and alkoxysilyl groups (e.g., trimethoxysilyl group, triethoxysilyl group, methyldimethoxysilyl group, etc., bonded to silicon atoms via alkylene groups which may contain one or two ester, urethane, or ether structures).
[0038] Examples of organosilicon compounds containing functional groups that impart adhesive properties include silane coupling agents, siloxanes having alkoxysilyl groups and organic functional groups, and compounds obtained by introducing alkoxysilyl groups into organic compounds having reactive organic groups. Examples of non-silicone organic compounds include allyl esters of organic acids such as triallyl isocyanurate, epoxy ring-opening catalysts, organotitanium compounds, organozirconium compounds, and organoaluminum compounds. The adhesive aid may be used alone or in combination of two or more types.
[0039] When using an adhesive aid, the amount to be added is preferably 0.05 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, per 100 parts by mass of component (A).
[0040] The addition-curable silicone composition of the present invention may contain inorganic fillers to improve its reinforcing properties. Examples of inorganic fillers include fuzzy silica (dry silica), precipitated silica (wet silica), crystalline silica, polysilsesquioxane, titanium dioxide, alumina, and fillers obtained by surface hydrophobizing these fillers with organosilicon compounds such as organoalkoxysilane compounds, organochlorosilane compounds, organosilazane compounds, and low molecular weight siloxane compounds. When using an inorganic filler, the amount to be blended is preferably 0.1 to 30 parts by mass, more preferably 1 to 15 parts by mass, per 100 parts by mass of component (A).
[0041] The addition-curable silicone composition of the present invention may contain organopolysiloxane raw rubber to improve its strength. Raw rubber refers to a high polymer that is either a very viscous liquid or a non-liquid (paste or solid) with no self-flow properties at room temperature (25°C). The average degree of polymerization of the above organopolysiloxane raw rubber is preferably 2,000 to 50,000, and more preferably 2,500 to 30,000. Examples of organopolysiloxane raw rubber include dimethylpolysiloxane, methylphenylpolysiloxane, methylvinylpolysiloxane, methylphenylsiloxane-dimethylsiloxane copolymer, methylvinylsiloxane-dimethylsiloxane copolymer, and methylphenylsiloxane-methylvinylsiloxane-dimethylsiloxane copolymer, in which both ends of the molecular chain are sealed with trimethylsiloxy groups, dimethylphenylsiloxane groups, vinyldimethylsiloxane groups, divinylmethylsiloxane groups, trivinylsiloxy groups, methylphenylvinylsiloxane groups, etc. When using organopolysiloxane raw rubber, the amount blended is preferably 0.1 to 30 parts by mass, more preferably 1 to 15 parts by mass, per 100 parts by mass of component (A).
[0042] There are no particular limitations on the method for preparing the addition-curable silicone composition of the present invention; the components (A) to (C) described above and any other components as needed can be mixed by appropriate means.
[0043] [2] Cured product The addition-curable silicone composition of the present invention can be cured to form a cured product. While there are no particular restrictions on the curing conditions, it is preferable to use a temperature of 100-250°C and a curing time of 30-300 minutes. Because the cured product of the present invention has an excellent balance of heat resistance, hardness, and flexibility, it can be suitably used as a binder component in heat-resistant paints and heat-resistant resins, as well as for coatings on building materials and molded articles, and as a coating material and sealing material for electronic components. [Examples]
[0044] The present invention will be described more specifically below with reference to synthesis examples, examples, and comparative examples, but the present invention is not limited to the following examples. The average composition of organopolysiloxanes was determined using an NMR analyzer manufactured by JEOL Ltd. 1 H-NMR and 29 These values are calculated from the integrated values of the Si-NMR spectrum, and similarly, the amount of alkenyl groups in the composition and the ratio of the number of hydrogen atoms bonded to silicon atoms to the alkenyl groups bonded to silicon atoms in the composition are also calculated. 1 The calculation was performed using 1H-NMR. The weight-average molecular weight (Mw) is the polystyrene-converted value obtained by GPC (gel permeation chromatography) measurement under the following conditions. [GPC conditions] Equipment: HLC-8220 (manufactured by Tosoh Corporation) Columns: TSKgel GMHXL-L, TSKgel G4000HXL, TSKgel G2000HXL ×2 Developing solvent: Tetrahydrofuran (THF) Flow rate: 1mL / min Detector: RI Column constant temperature bath temperature: 40℃ Standard material: Polystyrene
[0045] [1] Synthesis of organopolysiloxane resins [Synthesis Example 1] 4,086.6 g of methyltrimethoxysilane was placed in a glass flask equipped with a stirrer, thermometer, condenser, and dropping device. Then, 486 g of 1N hydrochloric acid was added dropwise over 1 hour while stirring, and the mixture was reacted at 67°C for 2 hours. The resulting solution was neutralized with 29.2 g of propylene oxide, and polysilsesquioxane (A-0) was obtained by distilling off the volatile components and solvent. 2,252 g of the obtained polysilsesquioxane (A-0), 1,090 g of vinylmethyldimethoxysilane, 876 g of methyldimethoxysilane, 1,292 g of hexamethyldisiloxane, and 4,137 g of toluene were mixed with 60 g of methanesulfonic acid while stirring. Then, 539 g of water was added dropwise over 1 hour, and the mixture was reacted at 67°C for 2 hours, followed by a reaction at a temperature range of 80-90°C for 3 hours. The resulting solution was washed with water until the extract water was neutral, and the solvent was removed by distillation to obtain the product. The proportions of each constituent unit in equation (1), calculated from the NMR measurement results of the obtained organopolysiloxane resin (A-1), are a=0, b=0.5, c=0, d=0, e=0.3, f=0.2, g=0, and h=0.02, respectively. 1 R is a methyl group, 2 The vinyl group:hydrogen atom = 50:50 (molar ratio), R 3 It was a hydrogen atom, with a weight-average molecular weight of 10,000 and an alkenyl group content of 0.2 moles / 100g.
[0046] [Synthesis Example 2] Organopolysiloxane resin (A-2) was synthesized using the same method as in Synthesis Example 1, except that polysilsesquioxane (A-0) was replaced with 1,3-diphenyl-1,1,3,3-tetramethoxydisiloxane in the same amount (calculated on a silicon atom basis). The proportions of each constituent unit in equation (1), calculated from the NMR measurement results of the obtained organopolysiloxane resin (A-2), are a=0, b=0.5, c=0, d=0, e=0.3, f=0.2, g=0, and h=0.02, respectively. 1 The ratio of methyl group to phenyl group is 9:5 (molar ratio), and R 2 The vinyl group:hydrogen atom = 50:50 (molar ratio), R3 is a hydrogen atom, with a weight-average molecular weight of 8,000 and an alkenyl group content of 0.2 mol / 100 g.
[0047] [2] Preparation of addition-curable silicone composition [Examples 1-1 to 1-7, Comparative Examples 1-1 to 1-3] The following components were mixed at 25°C in the compounding amounts (parts by mass) shown in Table 1 to prepare an addition-curable silicone composition. Also, the ratio (H / Vi) of the number of hydrogen atoms bonded to silicon atoms to the number of alkenyl groups bonded to silicon atoms in each composition was calculated from the results of NMR measurement.
[0048] Component (A) (A-1): Organopolysiloxane resin obtained in Synthesis Example 1 (A-2): Organopolysiloxane resin obtained in Synthesis Example 2 Component (B) (B-1): In the above formula (2), R 4 = methyl group, R 5 = hydrogen atom, R 6 = methyl group, and n = 20 represents a linear polysiloxane (B-2): In the above formula (2), R 4 = methyl group, R 5 = hydrogen atom, R 6 = methyl group, and n = 40 represents a linear polysiloxane (B-3): In the above formula (2), R 4 = methyl group, R 5 = hydrogen atom, R 6 = methyl group, and n = 10 represents a linear polysiloxane (B-4): In the above formula (2), R 4 = methyl group, R 5 = vinyl group, R 6 = vinyl group, and n = 1000 represents a linear polysiloxane Component (C) (C-1): Toluene solution of platinum-divinyltetramethyldisiloxane complex (platinum concentration 0.5% by mass) <B [[ID=B0]
[57] ]Other components Control agent: Ethinylmethyldecylcarbinol
[0049] [Table 1]
[0050] [3] Preparation and evaluation of cured products The compositions obtained in Examples 1-1 to 1-8 and Comparative Examples 1-1 to 1-3 were added to a Teflon® petri dish, heated at 200°C for 2 hours, and then allowed to cool to 25°C to produce a cured product with a thickness of 0.3 mm. The moldability, hardness, and tensile elongation at break of the obtained cured product were measured. The results are shown in Table 2.
[0051] (1) Formability When removing the hardened film from the petri dish, those showing significant cracks were marked with an "X," while those without cracks or other abnormalities and that could be removed as a single film were marked with a "○." (2)Hardness Hardness was measured using a Type A durometer in accordance with ASTM D2240. A score below A50 was marked with ×, and a score of A50 or higher was marked with ○. (3) Tensile break elongation The tensile elongation at fracture was calculated by taking a 1cm x 1cm test specimen, applying a load diagonally, and measuring the elongation until fracture, with the initial state set to 100%. Specimens showing an elongation of 5% or more were evaluated as "○".
[0052] [Table 2]
[0053] As shown in Table 2, the addition-curing silicone compositions used in Examples 2-1 to 2-8 exhibit an excellent balance of moldability, hardness, and tensile elongation, as well as good workability. On the other hand, Comparative Example 2-1 had insufficient (B) component, resulting in poor moldability; Comparative Example 2-2 had no problems with moldability, but lacked (B) component, resulting in poor tensile elongation at break; and Comparative Example 2-3 had an excess of (B) component, resulting in insufficient hardness.
Claims
1. (A) Polysiloxane resin represented by the following formula (1): 100 parts by mass 【Chemistry 1】 [In the formula, R 1 Each of these independently represents a monovalent hydrocarbon group having 1 to 12 carbon atoms that does not contain an aliphatic unsaturated bond, R 2 Each of these independently represents a hydrogen atom or an alkenyl group having 2 to 12 carbon atoms (however, R 2 The proportion of hydrogen atoms in the total number of atoms is 10-90 mol%, R 3 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. a, b, c, d, e, f, and g are numbers satisfying the following inequalities: 0 ≤ a ≤ 0.6, 0.2 ≤ b ≤ 0.9, 0 ≤ c ≤ 0.8, 0 ≤ d ≤ 0.6, 0 ≤ e ≤ 0.8, 0 ≤ f ≤ 0.6, 0 ≤ g ≤ 0.8, and 0.1 ≤ (c + e + g) ≤ 0.8 and a + b + c + d + e + f + g = 1. h is a number satisfying 0 ≤ h ≤ 1. (B) Linear polysiloxane represented by the following formula (2): 10 to 300 parts by mass, 【Chemistry 2】 (In the formula, R 4 Each of these independently represents a monovalent hydrocarbon group having 1 to 12 carbon atoms that does not contain an aliphatic unsaturated bond, R 5 Each of these independently represents a hydrogen atom or an alkenyl group with 2 to 12 carbon atoms, R 6 Each of these independently represents a monovalent hydrocarbon group with 1 to 12 carbon atoms, and n is an integer between 0 and 1,200. and (C) Platinum group metal catalyst An addition-curable silicone composition containing the above.
2. The above R 1 is a methyl group or a phenyl group, and the alkenyl group in the above R 2 is a vinyl group. The addition-curable silicone composition according to claim 1.
3. The addition-curable silicone composition according to claim 1, wherein a is 0.
4. The addition-curable silicone composition according to claim 1, wherein g is 0.
5. The addition-curable silicone composition according to claim 1, wherein c, e, and g are numbers satisfying 0 ≤ c ≤ 0.4, 0.1 ≤ e ≤ 0.5, 0 ≤ g ≤ 0.4, and 0.2 ≤ (c + e + g) ≤ 0.
8.
6. The addition-curable silicone composition according to claim 1, wherein the alkenyl group content in component (A) is 0.05 to 0.6 mol / 100g.
7. The addition-curable silicone composition according to claim 1, wherein the weight-average molecular weight (Mw) of component (A) in terms of polystyrene, as measured by gel permeation chromatography, is 1,000 to 50,000.
8. The addition-curable silicone composition according to claim 1, wherein the number of hydrogen atoms bonded to silicon atoms in the composition is 0.8 to 2.0 per alkenyl group bonded to silicon atoms in the composition.
9. A cured product of an addition-curable silicone composition according to any one of claims 1 to 8.