Curable silicone composition and adhesive

Abstract

The present application is a curable silicone composition comprising: (A) an organopolysiloxane which is an addition reaction product of (a) a compound represented by general formula (1) and (b) a compound represented by general formula (2), and has an average of 4 or more methacryl groups in one molecule, p is an integer of 10 or more, R 1 is a monovalent organic group having 1 to 12 carbon atoms, R 2 is an alkenyl group having 2 to 12 carbon atoms, q is an integer of 0 to 20, R 3 is a monovalent organic group having 1 to 12 carbon atoms, Z 1 is a divalent organic group having 1 to 10 carbon atoms; (B) an organic peroxide; (C) an organohydrogenpolysiloxane; and (D) a platinum group metal catalyst. Thus, a curable silicone composition which can be used as an adhesive, which is excellent in curability, and which does not cause curing failure or bubbling even in the presence of an addition reaction catalyst poison or moisture or the like on the surface of an adherend is provided.

Description

Technical Field

[0001] This invention relates to curable silicone compositions and adhesives made from the curable silicone compositions. Background Technology

[0002] Curable silicone compositions are widely used in electrical and electronic components and automotive parts due to their excellent heat resistance, cold resistance, safety, electrical insulation, and weather resistance. The curing reactions for these silicone compositions extensively utilize condensation reactions catalyzed by tin or titanium compounds and addition reactions catalyzed by platinum group elements.

[0003] Condensation-type silicones have a technical problem: they can cure due to moisture in the air, which results in a long curing time.

[0004] On the other hand, while addition-reactive silicones can be cured quickly by heating and have excellent workability, curing can sometimes be hindered by poisoning catalysts such as nitrogen, sulfur, and phosphorus compounds. Furthermore, because addition-reactive silicones use hydrogen-silicon bonds in the reaction, they present a technical problem: if moisture is present in the reaction system, it can cause dehydrogenation, resulting in air bubbles in the cured product.

[0005] As addition-reaction type organosilicones that can bond even in the presence of addition reaction catalyst poisons, methods using special adhesive aids (Patent Document 1) and methods adding peroxides (Patent Document 2) have been proposed. However, while these methods are effective when the amount of catalyst poison is small, the effect is insufficient when the amount of catalyst poison is large.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent No. 4430470

[0009] Patent Document 2: Japanese Patent No. 4314454 Summary of the Invention

[0010] The technical problem to be solved by the present invention

[0011] The present invention was made in view of the above circumstances, and its object is to provide a curable silicone composition that can be used as an adhesive, which has excellent curability and will not cause poor curing or blistering even if there are addition reaction catalyst poisons or moisture on the surface of the adhered object.

[0012] Technical means to solve technical problems

[0013] To solve the above-mentioned technical problems, the present invention provides a curable organosilicon composition comprising:

[0014] 100 parts by mass of (A) organopolysiloxane, which is the product of an addition reaction of (a) a compound represented by general formula (1) below and (b) a compound represented by general formula (2) below, and having an average of more than 4 methacryl groups in one molecule,

[0015] [Chemical Formula 1]

[0016]

[0017] In equation (1), p is an integer greater than or equal to 10, and R 1 R is an independent monovalent organic group, either substituted or unsubstituted, having 1 to 12 carbon atoms. 2 It is independently an alkenyl group having 2 to 12 carbon atoms.

[0018] [Chemical Formula 2]

[0019]

[0020] In equation (2), q is an integer from 0 to 20, and R 3 Z is an independent monovalent organic group, either substituted or unsubstituted, having 1 to 12 carbon atoms. 1 A divalent organic group having 1 to 10 carbon atoms, either substituted or unsubstituted;

[0021] 0.1 to 10 parts by weight of (B) organic peroxide;

[0022] 0.1 to 20 parts by mass of (C) organohydrogen polysiloxane, wherein one molecule has at least two hydrogen atoms bonded to silicon atoms; and

[0023] The content of platinum group metals relative to the total composition is 0.1 to 100 ppm by mass of the (D) platinum group metal catalyst.

[0024] If it is such a curable silicone composition, then component (A) has high free radical reactivity, so it has good curability, and component (A) and component (C) will undergo an addition reaction at the air interface where free radical reaction is not easily caused, so the surface curability is also good.

[0025] Furthermore, preferably, component (A) is the product of the hydrosilylation reaction of component (a) and component (b) with platinum group metals as catalysts.

[0026] By using highly active platinum group metals as catalysts, components (a) and (b) will react fully, making it easy to obtain the target structure.

[0027] Furthermore, it is preferable that the time taken until the surface cures in the air atmosphere is longer than the time taken until the interior cures.

[0028] If such an organosilicon composition is used, the effects of the present invention can be more effectively realized.

[0029] Furthermore, the present invention provides an adhesive composed of the above-described curable silicone composition.

[0030] The curable silicone composition of the present invention has excellent curability and will not cause poor curing or bubbling even if there are addition reaction catalysts, poisons or moisture on the surface of the adherend, so it is suitable for use in adhesives and the like.

[0031] Invention Effects

[0032] As explained above, with the curable silicone composition of the present invention, the curability of surfaces that are difficult to cure in free radical reactions becomes good, and even if there are addition reaction catalyst poisons or moisture on the surface of the adherend, it will not cause poor curing or blistering. Therefore, by using the curable silicone composition of the present invention, even in parts where addition reaction type silicone adhesives could not be used in the past due to curing obstacles, curing and bonding can be performed in a short time, which is very advantageous in terms of operability and cost reduction. Detailed Implementation

[0033] As described above, the aim is to develop a curable silicone composition that can be used as an adhesive, which has excellent curability and will not cause poor curing or bubbling even if there are addition reaction catalysts, poisons or moisture on the surface of the adherend.

[0034] To achieve the above objectives, the inventors conducted intensive research and discovered the following facts, thus completing the present invention: using organopolysiloxanes and organohydrosiloxanes with multiple methacryloyl groups at the ends of the molecular chains, the invention is cured by free radical polymerization of methacryloyl groups based on peroxides, while simultaneously carrying out addition reactions of methacryloyl groups with Si-H groups. This results in a curable organosilicon composition that does not suffer from poor curing or blistering even in the presence of addition reaction catalysts, poisons, or moisture, and exhibits excellent surface curability.

[0035] That is, the present invention is a curable organosilicon composition containing:

[0036] 100 parts by mass of (A) organopolysiloxane, which is the product of an addition reaction of (a) a compound represented by general formula (1) below and (b) a compound represented by general formula (2) below, and having an average of more than 4 methacryl groups in one molecule,

[0037] [Chemical Formula 3]

[0038]

[0039] In equation (1), p is an integer greater than or equal to 10, and R 1 R is an independent monovalent organic group, either substituted or unsubstituted, having 1 to 12 carbon atoms. 2 It is independently an alkenyl group having 2 to 12 carbon atoms.

[0040] [Chemical Formula 4]

[0041]

[0042] In equation (2), q is an integer from 0 to 20, and R 3 Z is an independent monovalent organic group, either substituted or unsubstituted, having 1 to 12 carbon atoms. 1 A divalent organic group having 1 to 10 carbon atoms, either substituted or unsubstituted;

[0043] 0.1 to 10 parts by weight of (B) organic peroxide;

[0044] 0.1 to 20 parts by mass of (C) organohydrogen polysiloxane, wherein one molecule has at least two hydrogen atoms bonded to silicon atoms; and

[0045] The content of platinum group metals relative to the total composition is 0.1 to 100 ppm by mass of the (D) platinum group metal catalyst.

[0046] The present invention will be described in detail below, but the present invention is not limited thereto.

[0047] <(A)Component>

[0048] (A) is an organopolysiloxane, which is the product of the addition reaction of (a) a compound represented by general formula (1) below and (b) a compound represented by general formula (2) below, and has an average of more than 4 methacryloyl groups in one molecule. Good curability can be obtained by locally having multiple methacryloyl groups at the ends of the molecular chain.

[0049] [Chemical Formula 5]

[0050]

[0051] [Chemical Formula 6]

[0052]

[0053] R 1Independently, it is a monovalent organic group having 1 to 12 carbon atoms, whether substituted or unsubstituted. Specifically, examples include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, octyl, nonyl, or decyl; aryl groups such as phenyl, tolyl, xylyl, or naphthyl; aralkyl groups such as benzyl, phenethyl, or phenylpropyl; or groups formed by substituting some or all of the hydrogen atoms of these groups with halogen atoms such as fluorine, bromine, or chlorine, or cyano groups, for example, halogen-substituted alkyl groups such as chloromethyl, chloropropyl, bromoethyl, and trifluoropropyl, or cyanoethyl groups. Groups having 1 to 8 carbon atoms are preferred, and methyl or phenyl groups are more preferred.

[0054] R 2 The group is an alkenyl group that has 2 to 12 carbon atoms, and preferably includes groups with 2 to 8 carbon atoms. Specifically, vinyl, allyl, butenyl, pentenyl, and hexenyl are examples, with vinyl being particularly preferred.

[0055] p is an integer greater than or equal to 10, preferably in the range of 10 to 2,000, and more preferably in the range of 100 to 1,500. If it is within this range, it will be a composition with good workability before curing and good flexibility after curing.

[0056] R 3 Independently, a monovalent organic group having 1 to 12 carbon atoms, whether substituted or unsubstituted, can be listed as an example of the above-mentioned R... 1 The groups that are the same as those shown in the examples, wherein methyl is preferred.

[0057] Z 1 The substituted or unsubstituted divalent organic groups having 1 to 10 carbon atoms are examples of alkylene groups such as methylene, ethylene, and trimethylene. Some or all of the hydrogen atoms in these organic groups can be replaced by halogen atoms such as fluorine, bromine, and chlorine, or cyano groups, and these hydrocarbon chains may also contain ether bonds, amide bonds, etc. Among these, alkylene groups having 1 to 6 carbon atoms are preferred, and alkylene groups having 1 to 3 carbon atoms are particularly preferred.

[0058] q is an integer from 0 to 20, and from the perspective of ease of synthesis, it is preferably 1.

[0059] The following shows a specific example of component (a). Wherein, C6H5 represents phenyl (the same applies below).

[0060] [Chemical Formula 7]

[0061]

[0062] These (a) ingredients may be used alone or in combination of two or more.

[0063] The following shows a specific example of component (b).

[0064] [Chemical Formula 8]

[0065]

[0066] (b) One ingredient may be used alone, or two or more ingredients may be used in combination.

[0067] Furthermore, preferably, component (A) is the product of the hydrosilylation reaction of component (a) and component (b) with a platinum group metal catalyst.

[0068] A catalyst can be used in the addition reaction of component (a) and component (b). Examples include platinum-supported carbon powder, platinum black, platinum chloride, chloroplatinic acid, the reaction product of chloroplatinic acid and a monohydric alcohol, complexes of platinum with vinylsiloxanes such as divinyltetramethyldisiloxane, complexes of chloroplatinic acid with olefins, platinum-based catalysts such as bis(acetoacetic acid)platinum, palladium-based catalysts, and rhodium-based catalysts. From a reactivity perspective, the presence of platinum is preferred. Furthermore, there are no particular limitations on the addition reaction conditions or the solvent used; conventional methods are acceptable.

[0069] The following are specific examples of component (A).

[0070] [Chemical Formula 9]

[0071]

[0072] These (A) ingredients can be used alone or in combination of two or more.

[0073] One molecule of component (A) contains an average of four or more methacryloyl groups (2-methylprop-2-enoyl) derived from component (b). Preferably, it contains five or more, more preferably six or more. When the number of methacryloyl groups is less than four on average, the deep curing property of the curable silicone composition is insufficient.

[0074] Furthermore, after component (A) undergoes an addition reaction with the Si-H group in component (C), it is preferable that it does not contain acryloyl (acryloyl-2-acryloyl) which may be hydrolyzed, in terms of durability.

[0075] <(B) Ingredients>

[0076] (B) is an organic peroxide that generates free radicals upon heating. (B) is not particularly limited as long as it can polymerize the methacryloyl group of (A) through a free radical reaction. Examples of (B) include ketone peroxides, hydroperoxides, diacyl peroxides, dialkyl peroxides, peroxy ketals, alkyl peresters, percarbonates, etc.

[0077] Considering the temperature at which the curable organosilicon composition can be cured by heating and its shelf life, the 10-hour half-life temperature of the organic peroxide in benzene is preferably 40°C or higher, more preferably 60°C or higher. Furthermore, there is no particular upper limit, and it is generally below 200°C.

[0078] Examples of such organic peroxides include 1,1-di(tert-butylperoxy)cyclohexane, tert-butyl peroxide (3,5,5-trimethylhexanoate), 1,6-bis(tert-butylperoxycarbonyloxy)hexane, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, 2,2-di(tert-butylperoxy)butane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, benzoyl peroxide, benzoyl-m-methylbenzoyl peroxide, and m-toluyl peroxide. They can be used alone, or in appropriate combinations of two or more, or as substances prepared by diluting them with a solvent.

[0079] The amount of organic peroxide incorporated relative to 100 parts by weight of component (A) is 0.1 to 10 parts by weight, preferably 0.2 to 8 parts by weight. If it is less than 0.1 parts by weight, it is not sufficient to suppress poor curing or blistering caused by addition reaction catalyst poisoning or moisture on the surface of the adherend. If it is greater than 10 parts by weight, it may adversely affect the storage stability of the composition or the properties after curing.

[0080] <(C) Ingredients>

[0081] (C) is an organohydrogen polysiloxane, one molecule of which has at least 2, preferably 3 to 500, more preferably 3 to 200, and particularly preferably 3 to 100 hydrogen atoms bonded to silicon atoms (i.e., SiH groups), and has the function of compensating for poor curing at the air interface in free radical polymerization by adding to (A).

[0082] The number of silicon atoms (or degree of polymerization) in one molecule of component (C) is preferably 2 to 1,000, more preferably 3 to 300, and particularly preferably 4 to 150.

[0083] (C) The SiH group in the component can be located at either the end of the molecular chain or at the non-end of the molecular chain, or both.

[0084] Specific examples of organic groups other than the SiH group that bond to silicon atoms include R, which is a component of (A) above. 1 The illustrated groups are identical and do not have substituted or unsubstituted monovalent organic groups with aliphatic unsaturated bonds.

[0085] As such an organohydrogen polysiloxane, it is preferably as shown in the average composition formula (3) below.

[0086] R 4 d H e SiO (4-d-e) / 2 (3)

[0087] R 4 It is a monovalent organic group with 1 to 12 carbon atoms that does not have an aliphatic unsaturated bond, whether substituted or unsubstituted. Examples of such monovalent organic groups include R, which is a component of (A). 1 The groups that are the same as those shown in the examples are preferably alkyl or aryl, and more preferably methyl or phenyl. d and e are positive numbers that satisfy 0.7≤d≤2.1, 0.001≤e≤1.0, and 0.8≤d+e≤3.0, and are preferably positive numbers that satisfy 1.0≤d≤2.0, 0.01≤e≤1.0, and 1.5≤d+e≤2.5.

[0088] The viscosity of component (C) at 25°C is preferably 0.5 to 100,000 mPa·s, particularly preferably 10 to 5,000 mPa·s. This viscosity can be, for example, a value measured using a rotational viscometer at 25°C. The molecular structure of such organohydrogen polysiloxanes is not particularly limited; examples include linear, branched, partially branched linear, cyclic, and three-dimensional network structures. The organohydrogen polysiloxane can be a homopolymer composed of a single siloxane unit, a copolymer composed of two or more siloxane units, or a mixture thereof. Examples of such organohydrosiloxanes include 1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, methylhydrosiloxane cyclic polymers, methylhydrosiloxane-dimethylsiloxane cyclic copolymers, dimethylhydrosiloxane-terminated dimethylpolysiloxanes with both ends of the molecular chain ending in dimethylhydrosiloxane, trimethylsiloxane-terminated methylhydrosiloxanes with both ends of the molecular chain ending in trimethylsiloxane, dimethylhydrosiloxane-dimethylsiloxane-diphenylsiloxane copolymers with both ends of dimethylhydrosiloxane, and (CH3)2HSiO 1 / 2 Unit and (CH3)3SiO 1 / 2 Unit and SiO 4 / 2 The copolymer composed of units, from (CH3)2HSiO 1 / 2 Unit and SiO 4 / 2 Copolymers composed of units, etc.

[0089] The content of component (C) is 0.1 to 20 parts by mass relative to 100 parts by mass of component (A), preferably 0.5 to 20 parts by mass, and particularly preferably 1 to 10 parts by mass. If the content of component (C) is less than 0.1 parts by mass or greater than 20 parts by mass, there is a possibility that the air interface of the curable silicone composition of the present invention is not sufficiently cured, resulting in residual adhesiveness on the surface.

[0090] Furthermore, the molar ratio of the SiH group in component (C) to the alkenyl group in the curable organosilicon composition of the present invention is preferably 0.01 to 5.0, more preferably 0.1 to 4.0, and particularly preferably 0.5 to 3.0.

[0091] <(D) Components>

[0092] (D) is a platinum group metal catalyst that promotes the addition reaction. Examples of platinum group metal catalysts include those exemplified in component (A) above as catalysts for the addition reaction of components (a) and (b), wherein a catalyst containing platinum is preferred.

[0093] In addition, platinum group metal catalysts can be used in the synthesis of component (A), either directly or added to the composition.

[0094] (D) The amount of component added is 0.1 to 100 ppm of platinum group metals relative to the total mass of the composition, preferably 0.2 to 10 ppm. If it is less than 0.1 ppm, the surface curing property of the composition is insufficient; if it is greater than 100 ppm, the composition is prone to foaming due to the influence of moisture.

[0095] <Other Ingredients>

[0096] In the curable silicone composition of the present invention, adhesiveness improvers, free radical reaction inhibitors, addition reaction inhibitors, and other components may be added according to the purpose.

[0097] From the perspective of imparting self-adhesive properties to the curable organosilicon composition of the present invention, as an adhesion enhancer, organosilicon compounds such as silanes and siloxanes, as well as non-organosilicon organic compounds, containing functional groups that impart adhesion properties can be used.

[0098] Specific examples of functional groups that impart adhesive properties include alkenyl groups such as vinyl and allyl that are already bonded to silicon atoms, or epoxy groups (e.g., γ-glycidoxypropyl, β-(3,4-epoxycyclohexyl)ethyl, acryloyloxy (e.g., γ-acryloyloxypropyl), or methacryloyloxy (e.g., γ-methacryloyloxypropyl), and alkoxysilyl groups (e.g., trimethoxysilyl, triethoxysilyl, methyldimethoxysilyl, etc., which are already bonded to silicon atoms by hydrogen or carbon atoms).

[0099] Examples of organosilicon compounds containing functional groups that impart adhesion include silane coupling agents, siloxanes having alkoxysilanes and organic functional groups, and compounds formed by introducing alkoxysilanes into organic compounds having reactive organic groups.

[0100] In addition, examples of non-organosilicon organic compounds include allyl esters of organic acids, epoxy ring-opening catalysts, organotitanium compounds, organozirconium compounds, and organoaluminum compounds.

[0101] Examples of free radical reaction inhibitors include phenolic free radical reaction inhibitors such as BHT (butylated hydroxytoluene) and amine free radical reaction inhibitors such as diphenylamine derivatives.

[0102] Examples of addition reaction inhibitors include phosphorus-containing compounds such as triphenylphosphine; nitrogen-containing compounds such as tributylamine, tetramethylethylenediamine, and benzotriazole; sulfur-containing compounds, acetylene compounds, hydroperoxide compounds, maleic acid derivatives, 1-ethynylcyclohexanol, 3,5-dimethyl-1-hexyn-3-ol, ethynylmethyldecylmethanol, and 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane.

[0103] The degree of curing inhibition effect produced by the reaction inhibitor varies depending on the chemical structure of the reaction inhibitor. Therefore, it is preferable to adjust the amount of reaction inhibitor to be the most suitable amount for each reaction inhibitor used.

[0104] Furthermore, the curable organosilicon composition of the present invention may incorporate inorganic fillers such as micronized silica, crystalline silica, hollow fillers, and silsesquioxanes to improve reinforcing properties; and fillers prepared by surface hydrophobication treatment of these fillers using organosilicon compounds such as organoalkoxysilane compounds, organochlorosilane compounds, organosilazane compounds, and low molecular weight siloxane compounds; as well as silicone rubber powder, organosilicon resin powder, etc.

[0105] <Curing Organosilicon Composition>

[0106] The curable silicone composition of the present invention comprises the above-mentioned components (A) to (D) and other components as needed.

[0107] The curable silicone composition of the present invention takes longer to cure on the surface in an air atmosphere than to cure internally. This means that the free radical polymerization reaction of component (A) using component (B) occurs before the addition reaction between component (A) and component (C). By first carrying out the free radical polymerization reaction, poor curing or blistering will not occur even if there are addition reaction catalyst poisons or moisture on the surface of the material being contacted.

[0108] The surface curing time is preferably 1.2 times or more than the internal curing time, and more preferably 1.5 to 50 times. If it is 1.2 times or more, poor curing and blistering can be more effectively suppressed on the surface of substances containing addition reaction catalysts, poisons, or moisture, etc. If it is less than 50 times, the surface curing will not be excessively slowed down.

[0109] <Adhesive>

[0110] The curable silicone composition of the present invention can be used as an adhesive. There are no particular limitations on the substrates to which the adhesive comprising the curable silicone composition of the present invention can be applied; examples include metals and organic resins. By curing the curable silicone composition of the present invention on the substrate at a temperature of 150°C or below, preferably 60 to 120°C, the substrate can be bonded to silicone rubber.

[0111] As described above, the curable silicone composition of the present invention has excellent curability and will not cause poor curing or bubbling even if there are addition reaction catalysts, poisons or moisture on the surface of the adherend, and is therefore suitable for use in adhesives and the like.

[0112] Example

[0113] The present invention is illustrated below with examples and comparative examples, but the invention is not limited to the examples described below. Additionally, the abbreviations for each siloxane unit are as follows.

[0114] [Chemical Formula 10]

[0115]

[0116] [Synthesis example 1]

[0117] In a 1L four-necked flask equipped with a stirrer, cooling pipe, and thermometer, the structural unit ratio of added siloxane units is M. 3V 500 g of an organopolysiloxane (80 mmol vinyl content) with a viscosity of 10 Pa·s at 25°C and a D ratio of 2:500, 22.9 g of the compound represented by formula (4) below (88 mmol SiH content), and 0.10 g of a toluene solution (0.5% by mass) of a Karstedt catalyst (platinum(0)1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex) were stirred and heated to 90°C in an oil bath. After stirring at 90°C for 3 hours, the mixture was cooled to room temperature to obtain 523 g of a colorless, transparent, oily reaction product (A-1).

[0118] Determination of reaction product (A-1) 1 H NMR results showed that the SiH group disappeared, and it was an organopolysiloxane formed by adding SiH groups of the compound represented by the following formula (4) to all alkenes.

[0119] [Chemical Formula 11]

[0120]

[0121] [Synthesis example 2]

[0122] In a 1L four-necked flask equipped with a stirrer, cooling pipe, and thermometer, the structural unit ratio of added siloxane units is M. 3V 500g of an organopolysiloxane (54mmol vinyl content) with a viscosity of 30 Pa·s at 25°C and a ratio of D = 2:750, 15.4g of the compound represented by formula (4) above (59mmol SiH content), and 0.10g of a toluene solution of Karstedt catalyst (0.5% by mass platinum content) were stirred and heated to 90°C in an oil bath. After stirring at 90°C for 3 hours, the mixture was cooled to room temperature to obtain 515g of a colorless, transparent, oily reaction product (A-2).

[0123] Determination of reaction product (A-2) 1 H NMR results showed that the SiH group disappeared, indicating that it was an organopolysiloxane formed by adding the SiH group of the compound represented by formula (4) to all vinyl groups.

[0124] [Synthesis example 3]

[0125] In a 1L four-necked flask equipped with a stirrer, cooling pipe, and thermometer, the structural unit ratio of added siloxane units is M. 3V :D :D 2Φ 500 g of an organopolysiloxane (80 mmol vinyl content) with a viscosity of 10 Pa·s at 25°C and a ratio of 2:390:43, 22.9 g of the compound represented by formula (4) above (88 mmol SiH content), and 0.10 g of a toluene solution of Karstedt catalyst (0.5% by mass platinum content) were stirred and heated to 90°C in an oil bath. After stirring at 90°C for 3 hours, the mixture was cooled to room temperature to obtain 523 g of a colorless, transparent, oily reaction product (A-3).

[0126] Determination of reaction product (A-3) 1 H NMR results showed that the SiH group disappeared, indicating that it was an organopolysiloxane formed by adding the SiH group of the compound represented by formula (4) to all vinyl groups.

[0127] [Synthesis Example 4]

[0128] In a 1L four-necked flask equipped with a stirrer, cooling pipe, and thermometer, the structural unit ratio of added siloxane units is M. 3V500g of an organopolysiloxane (80mmol vinyl content) with a viscosity of 10 Pa·s at 25°C and a ratio of D = 2:500, 15.4g of the compound represented by formula (4) above (59mmol SiH content), and 0.10g of a toluene solution of Karstedt catalyst (0.5% by mass platinum content) were stirred and heated to 90°C in an oil bath. After stirring at 90°C for 3 hours, the mixture was cooled to room temperature to obtain 514g of a colorless, transparent, oily reaction product (A-4).

[0129] Determination of reaction product (A-4) 1 H NMR results showed that the SiH group disappeared, indicating that it was an organopolysiloxane formed by adding the SiH group of the compound represented by formula (4) to an average of 4 vinyl groups per molecule.

[0130] [Synthesis example 5]

[0131] In a 1L four-necked flask equipped with a stirrer, cooling pipe, and thermometer, the structural unit ratio of added siloxane units is M. 3V 500g of an organopolysiloxane (80mmol vinyl content) with a viscosity of 10 Pa·s at 25°C and a ratio of D = 2:500, 7.7g of the compound represented by formula (4) above (30mmol SiH content), and 0.10g of a toluene solution of Karstedt catalyst (0.5% by mass platinum content) were heated to 90°C in an oil bath while stirring. After stirring at 90°C for 3 hours, the mixture was cooled to room temperature to obtain 507g of a colorless, transparent, oily reaction product (A-5).

[0132] Determination of reaction product (A-5) 1 H NMR results showed that the SiH group disappeared, indicating that it was an organopolysiloxane formed by adding the SiH group of the compound represented by formula (4) to an average of 2 vinyl groups per molecule.

[0133] [Synthesis example 6]

[0134] In a 1L four-necked flask equipped with a stirrer, cooling pipe, and thermometer, the structural unit ratio of added siloxane units is M. V 500g of an organopolysiloxane (27mmol vinyl content) with a viscosity of 10 Pa·s at 25°C and a ratio of D = 2:500, 7.7g of the compound represented by formula (4) above (30mmol SiH content), and 0.10g of a toluene solution of Karstedt catalyst (0.5% by mass platinum content) were heated to 90°C in an oil bath while stirring. After stirring at 90°C for 3 hours, the mixture was cooled to room temperature to obtain 507g of a colorless, transparent, oily reaction product (A-6).

[0135] Determination of reaction product (A-6) 1 H NMR results showed that the SiH group disappeared, indicating that it was an organopolysiloxane formed by adding the SiH group of the compound represented by formula (4) to all vinyl groups.

[0136] [Examples 1-7, Comparative Examples 1-6]

[0137] The following components were mixed in the amounts shown in Tables 1 and 2 to prepare a curable silicone composition. Unless otherwise stated, the component values ​​in Tables 1 and 2 represent parts by mass.

[0138] (A) Ingredients:

[0139] (A-1) The organopolysiloxane obtained in Synthesis Example 1

[0140] (A-2) The organopolysiloxane obtained in Synthesis Example 2

[0141] (A-3) The organopolysiloxane obtained in Synthesis Example 3

[0142] (A-4) The organopolysiloxane obtained in Synthesis Example 4

[0143] (A-5) The organopolysiloxane obtained in Synthesis Example 5

[0144] (A-6) The organopolysiloxane obtained in Synthesis Example 6

[0145] (A-7) The ratio of structural units in the siloxane unit is M. 3V Organopolysiloxane with D = 2:500 and a viscosity of 10 Pa·s at 25°C

[0146] (B) Ingredients:

[0147] (B-1) A 70% by mass solution of 1,6-bis(tert-butylperoxycarbonyloxy)hexane in tributyl citrate acetate (manufactured by KAYAKU NOURYON CORPORATION, trade name: KAYAREN 6-70, 10-hour half-life in benzene at 0.2 mol / L, temperature: 97°C)

[0148] (B-2) A 40% by mass xylene solution of a mixture of benzoyl peroxide, benzoyl m-methylbenzoyl peroxide and m-toluyl peroxide (manufactured by NOF CORPORATION, trade name: NYPER BMT-K40, 10-hour half-life in benzene at 0.05 mol / L, temperature: 73°C)

[0149] (C) Composition: The ratio of structural units of siloxane units is M:D:DH Organohydrogen polysiloxane with a ratio of 2:17:45 and a viscosity of 50 mPa·s at 25°C.

[0150] (D) Composition: Toluene solution of Karstedt catalyst (platinum(0)1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex) (platinum content 0.5% by mass)

[0151] (E) Ingredient: 3-Methacryloyloxypropyltrimethoxysilane

[0152] (F) Ingredient: Ethynylmethyldecylmethanol

[0153] [Table 1]

[0154]

[0155] ※1 The value in parentheses indicates the amount of active ingredient (parts by mass).

[0156] ※2 The value in parentheses indicates the platinum content (ppm by mass) relative to the total composition, taking into account the amount of platinum catalyst remaining in component (A).

[0157] [Table 2]

[0158]

[0159] ※1 The value in parentheses indicates the amount of active ingredient (parts by mass).

[0160] ※2 The value in parentheses indicates the platinum content (ppm by mass) relative to the total composition, taking into account the amount of platinum catalyst remaining in component (A).

[0161] The curable silicone compositions obtained in Examples 1-7 and Comparative Examples 1-6 were evaluated as follows, and the results are shown in Tables 3 and 4.

[0162] [hardness]

[0163] The hardness of the composition was determined using Type A hardness testing at 25°C after curing at 120°C for 1 hour and then standing at 25°C for 24 hours. The uncured state of the surface was recorded as "uncured".

[0164] [Deep curing time]

[0165] Add 20g of the composition to an aluminum petri dish with a diameter of 60mm and place it in an environment of 120℃. Then check the internal state (the inner side more than 2mm from the surface) at time points of 2.5 minutes, 5 minutes, 7.5 minutes, 10 minutes, 12.5 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 40 minutes, 50 minutes, and 60 minutes. Record the time when the curing is confirmed as the deep curing time.

[0166] [Surface curing time]

[0167] Add 20g of the composition to an aluminum petri dish with a diameter of 60mm and place it in an environment of 120℃. Then check the surface curing at time points of 2.5 minutes, 5 minutes, 7.5 minutes, 10 minutes, 12.5 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 40 minutes, 50 minutes, and 60 minutes. Record the time when the stickiness disappears as the surface curing time.

[0168] [Addition Reaction Catalyst Poisoning Adhesion Test]

[0169] Prepare two aluminum plates coated with 3-mercaptopropyltrimethoxysilane as a platinum group metal catalyst poison. Sandwich the various compositions between the plates to a thickness of 2 mm and heat at 120°C for 1 hour to cure. Peel the two aluminum plates apart. Record the case where the cured silicone has solidified and broken down as "adhesive," and the case where the interface between the silicone and the aluminum plate is not cured as "uncured."

[0170] [Fogging Resistance Test]

[0171] Prepare a 66 nylon sheet and a glass plate that have been exposed to an environment of 30°C and 90% RH for 24 hours. Clamp the above composition between them with the 66 nylon sheet on the bottom and the glass plate on the top, with a thickness of 2 mm. Heat at 120°C for 1 hour to cure. The condition in which bubbles can be observed with the naked eye on the glass surface is recorded as "bubbling", and the condition in which no bubbles can be observed is recorded as "no bubbles".

[0172] [Table 3]

[0173]

[0174] [Table 4]

[0175]

[0176] As shown in Table 3, the curable silicone compositions of Examples 1 to 7 exhibit excellent surface curing properties, and particularly excellent deep curing properties. They do not become uncured or have reduced adhesion in the presence of addition reaction catalyst poisons, demonstrating that they do not produce bubbles even if the adhered materials contain moisture.

[0177] On the other hand, as shown in Table 4, in Comparative Example 1 where component (C) was not used, the surface was not cured. Furthermore, in Comparative Example 2 where component (B) was not used, curing was hindered due to the poisoning of the addition reaction catalyst, and the adhered material blistered due to moisture. Moreover, in Comparative Example 3, where the amount of component (B) was low, the deep curing time was equal to the surface curing time, and blistering occurred due to moisture.

[0178] Furthermore, the deep curing times of Comparative Examples 4-6, which used organopolysiloxanes containing unsaturated groups with a small number of methacryloyl groups that were not included in the range of component (A), were all very long. In Comparative Examples 4 and 6, because each molecule of (A-5) and (A-7) contained few methacryloyl groups, the free radical reaction was slow, and the addition reaction between the unsaturated group and the SiH group occurred first, resulting in bubbling due to the influence of moisture. In Comparative Example 5, both the free radical reaction of the methacryloyl group and the addition reaction between the unsaturated group and the SiH group were very slow, resulting in insufficient curing.

[0179] Furthermore, this invention is not limited to the above-described embodiments. The above embodiments are illustrative examples, and any technical solutions having a substantially identical structure and achieving the same effect as the technical concept described in the claims of this invention are included within the scope of protection of this invention.

Claims

1. A curable silicone composition, characterized by, contains: 100 parts by mass of (A) an organopolysiloxane which is an addition reaction product of (a) a compound represented by the following general formula (1) and (b) a compound represented by the following general formula (2) and has an average of 4 or more methacryl groups in one molecule, [Chemical Formula 1] In formula (1), p is an integer of 10 or more, R 1 independently a substituted or unsubstituted monovalent organic group having 1 to 12 carbon atoms, R 2 independently an alkenyl group having 2 to 12 carbon atoms, [Chemical Formula 2] In formula (2), q is an integer of 0 to 20, R 3 independently a substituted or unsubstituted monovalent organic group having 1 to 12 carbon atoms, Z 1 is a substituted or unsubstituted divalent organic group having 1 to 10 carbon atoms; 0.1 to 10 parts by mass of (B) an organic peroxide; 0.1 to 20 parts by mass of (C) an organohydrogenpolysiloxane having at least 2 hydrogen atoms bonded to silicon atoms in one molecule; and (D) a platinum group metal catalyst in an amount of 0.1 to 100 mass ppm relative to the entire composition.

2. The curable silicone composition according to claim 1, characterized by The (A) component is a product of a hydrosilylation reaction of the (a) component and the (b) component catalyzed by a platinum group metal.

3. The curable silicone composition according to claim 1, characterized by It takes a longer time to cure the surface than to cure the interior in an air atmosphere.

4. The curable silicone composition according to claim 2, characterized by It takes a longer time to cure the surface than to cure the interior in an air atmosphere.

5. An adhesive characterized by, It takes a longer time to cure the surface than to cure the interior in an air atmosphere. It takes a longer time to cure the surface than to cure the interior in an air atmosphere. It takes a longer time to cure the surface than to cure the interior in an air atmosphere.

Images