JP2008045039A - Silicone-based polymer particle and silicone-based composition containing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a silicone-based composition excellent in tensile properties and transparency. <P>SOLUTION: Silicone-based polymer particles(A) are provided, being such as to have a silicone core-alkoxysilane condensate shell structure with silicone particles 0.01-1.0 μm in volume-average size coated with an alkoxysilane condensate and also be surface-treated with a neutral silylating agent. The silicone-based composition comprises (A) the above silicone-based polymer particles, (B) a polyorganosiloxane having in one molecule at least one alkenyl group, (C) an organohydrogenpolysiloxane and (D) a hydrosilylating catalyst. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a silicone-based composition comprising transparent silicone-based polymer particles having excellent tensile properties and a polyorganosiloxane having at least one alkenyl group in the molecule.

  Silicone compositions are excellent in heat resistance, cold resistance, weather resistance, light resistance, chemical stability, electrical properties, flame resistance, water resistance, transparency, colorability, non-adhesiveness, and non-corrosion. Although it is used in various industries, it has a drawback of low strength. In order to improve the strength, silica is generally added, but there are problems such as becoming opaque or increasing the specific gravity. It is also known to add silicone rubber powder, polyorganosilsesquioxane powder, silicone rubber powder coated with polyorganosilsesquioxane, etc. to improve strength. Insufficient, especially because the particle size is large, there was a problem that could adversely affect the transparency (see, for example, Patent Documents 1 and 2).

  Silicone rubber powder coated with silicone rubber powder or polyorganosilsesquioxane is obtained by crosslinking the rubber part by addition reaction of vinyl group-containing polyorganosiloxane and hydrogenorganopolysiloxane in the presence of a platinum catalyst. It has gained. In this method, there is a problem that the rubber properties become non-uniform due to the deactivation of the platinum catalyst, and it is difficult to control the particle size. Moreover, since an expensive platinum catalyst was used, it was economically disadvantageous (for example, refer patent document 2).

  In addition, the surface of various particles for improving strength is generally treated with chlorosilane in order to improve the affinity with the silicone composition, but this reaction of chlorosilane is an equilibrium reaction and is efficient. In order to make the reaction proceed well, it was necessary to remove hydrogen chloride produced by the reaction from the reaction system. Moreover, the residue of the chlorosilane which could not be reacted remained in the silicone composition, which sometimes caused a decrease in transparency.

As described above, the present situation is that an additive capable of increasing the strength of the silicone-based composition and maintaining the transparency is required.
JP-A-2-163127 Japanese Patent No. 2832143

  An object of the present invention is to provide silicone polymer particles having excellent tensile properties and excellent transparency, and a silicone composition, in which the above-described problems have been solved.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the silicone polymer particles surface-treated with a neutral silylating agent and the polyorganosiloxane having at least one alkenyl group in the molecule The present inventors have found that a silicone composition containing an organohydrogenpolysiloxane and a hydrosilylation catalyst has both good tensile properties and transparency, and has completed the present invention.

  That is, the present invention provides: (A-1) (A) silicone core-alkoxysilane in which (A-2) an alkoxysilane condensate shell is coated on silicone particles having a volume average particle size of 0.01 to 1.0 μm. The present invention relates to a silicone polymer particle having a condensate shell structure, which is surface-treated with a neutral silylating agent.

Preferred embodiments are:
The silicone particles as the component (A-1) are represented by the general formula (1).
R _m SiO _{(4-m) / 2} (1)
Wherein R is a substituted or unsubstituted monovalent hydrocarbon group, each of which may be the same or different, and is represented by m in the above general formula (1). = 2 The structural unit of 2 occupies 80 mol% or more of the total component (A-1).

Preferred embodiments are:
(A-1) The silicone polymer particles, wherein the silicone particles as the component are organosiloxanes having silanol groups at the molecular ends.

Preferred embodiments are:
The (A) component is coated with 5 to 90% by weight of the alkoxysilane condensate shell part (A-2) with respect to 10 to 95% by weight of the core part of the silicone particles (A-1). The silicone polymer particle, which is a polymer.

Preferred embodiments are:
In the alkoxysilane condensate shell part which is the component (A-2), the portion composed of the following component (a) and / or the following component (b) occupies 50% by weight or more of the total component (A-2). The silicone polymer particles are characterized by the above.

  (A) Component: General formula (4)

(Wherein R ³² , R ³³ and R ³⁴ represent the same or different monovalent organic groups, and R ³⁵ represents a monovalent organic group) and / or Its partial condensate,
(B) Component: General formula (5)

(Wherein R ⁴² , R ⁴³ , R ⁴⁴ and R ⁴⁵ represent the same or different monovalent organic groups) and / or a partial condensate thereof.

The present invention also provides:
(A) containing the silicone polymer particles, (B) a polyorganosiloxane having at least one alkenyl group in the molecule, (C) an organohydrogenpolysiloxane, and (D) a hydrosilylation catalyst. The present invention relates to the silicone-based composition.

Preferred embodiments are:
The silicone composition, wherein the component (A) is uniformly dispersed in the composition by a masterbatch method.

  According to the present invention, a transparent silicone-based composition having excellent tensile characteristics can be obtained. For example, a material that requires high light transmission, particularly short wavelength light transmission, particularly sealing of various light emitting and receiving elements. It can be used as a material.

The present invention is described in detail below.
The silicone composition of the present invention contains specific silicone polymer particles, a polyorganosiloxane having at least one alkenyl group in the molecule, an organohydrogenpolysiloxane, and a hydrosilylation catalyst. It is a system composition.

<(A) Silicone polymer particles>
In the present invention, the component (A) comprises: (A-1) a silicone particle having a volume average particle diameter of 0.01 to 1.0 μm and (A-2) an alkoxysilane condensate shell part coated on (A) silicone Silicone polymer particles having a core-alkoxysilane condensate shell structure, wherein the silicone polymer particles are surface-treated with a neutral silylating agent.

  (A) component in this invention mix | blends and uses for a silicone composition with below-mentioned (B)-(D) component, maintains the transparency of (B) component which is matrix resin, and improves a tensile characteristic. be able to. The effect obtained by using the component (A) that can increase the strength such as tensile properties while maintaining such transparency is a combination of various additives such as silica that easily lose transparency. This is a remarkable feature compared to the conventional method. Therefore, the present invention relates to silicone polymer particles such as the component (A).

  The component (A) is not particularly limited as long as the component (A-1) is coated with the component (A-2), but the composition and the like are not particularly limited, but the core part 10 of the silicone particle that is the component (A-1) It is preferable that the polymer particles are coated with 5 to 90% by weight of the (A-2) component alkoxysilane condensate shell part with respect to -95% by weight, and (A-1) component 40 to 95% by weight. More preferably, the polymer particles are coated with 5 to 60% by weight of component (A-2) in the presence of. However, (A-1) component and (A-2) component are made into 100 weight% collectively. Furthermore, the polymer particles are more preferably coated with 5 to 55% by weight of component (A-2) in the presence of 45 to 95% by weight of component (A-1). When the component (A-1) is less than 10% by weight, the difference in refractive index between the silicone polymer particles and the matrix resin increases, and the transparency of the composition tends to decrease, and the component (A-2) If it is less than 5% by weight, the strength of the composition tends to be insufficiently improved.

As the component (A-1), the general formula (1)
R _m SiO _{(4-m) / 2} (1)
(Wherein R is a substituted or unsubstituted monovalent hydrocarbon group, which may be the same or different from each other), and a polymer obtained by polymerizing an organosiloxane having a structural unit represented by .
In addition, in the component (A-1), it is preferable that the structural unit of m = 2 in the general formula (1) occupies 80 mol% or more of the entire component (A-1), and occupies 90 mol% or more. More preferably. If it is less than 80 mol%, the flexibility of the component (A-1) tends to be impaired, and the stress relaxation effect of the silicone-based composition may decrease.

The organosiloxane has a linear, branched or cyclic structure, but it is preferable to use an organosiloxane having a cyclic structure from the viewpoint of availability and cost.
Examples of the substituted or unsubstituted monovalent hydrocarbon group represented by R of the organosiloxane include an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, and a butyl group; a phenyl group And aryl groups having 6 to 24 carbon atoms such as naphthyl group and toluyl group; substituted hydrocarbon groups in which they are substituted with a cyano group or the like.

  Specific examples of the organosiloxane include hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6), trimethyltriphenylcyclotrimethyl. In addition to cyclic compounds such as siloxane, linear or branched organosiloxanes can be exemplified. These organosiloxanes can be used alone or in combination of two or more.

  Moreover, it is preferable that the terminal of the molecule | numerator of (A-1) component is a silanol group. By having a silanol group at the end of the molecule, a bond is formed by a condensation reaction with the later-described component (A-2), so that the silicone polymer particles having a stable core-shell structure are formed. Obtainable.

  The method for producing the silicone particles used in the present invention is not particularly limited, but can be produced by an ordinary emulsion polymerization method, and emulsion polymerization can be performed in consideration of the point that the particle diameter can be controlled and simplicity. It is preferable to obtain.

  The silicone particles (also referred to as silicone core) as component (A-1) can be produced, for example, by a conventional emulsion polymerization method carried out under acidic or basic conditions. It is more advantageous than the reaction under alkaline conditions because it is easy to suppress gelation in the condensation reaction of alkoxysilane described later. For example, various raw materials containing the above organosiloxane are made into an emulsion using an emulsifier and water together with a homomixer, colloid mill, homogenizer, etc., and then the pH of the system is preferably 5 or less, more preferably 4 using an acid component. Adjust to the following and heat to polymerize.

  As the acid component used in this case, it is preferable that the emulsion polymerization can proceed stably and also has an emulsifying ability itself, and examples thereof include alkylbenzenesulfonic acid, alkylsulfuric acid, alkylsulfosuccinic acid and the like. . In addition, as an alkyl group in each illustration of the said acid component, a C1-C20 thing is preferable. The same applies to each example of the emulsifier described below.

  After adding all of the raw materials at once, the pH may be adjusted to an arbitrary value after stirring for a certain period of time, or the remaining emulsion is adjusted to an arbitrary value by charging a part of the raw materials. Raw materials may be added sequentially.

The pH during the polymerization is not particularly limited, but the pH is preferably adjusted to 5 or less, more preferably 4 or less, because the polymerization proceeds safely and sufficiently. When adding organosiloxane sequentially, it may be added as it is or mixed with water and an emulsifier to form an emulsion, but from the viewpoint of polymerization rate, a method of adding in an emulsified state should be used. Is preferred.
Although there is no restriction | limiting in particular in reaction temperature and time, 0-100 degreeC is preferable and 50-95 degreeC is more preferable from the ease of reaction control. The reaction time is preferably 1 to 100 hours, more preferably 3 to 50 hours.

  When polymerization is carried out under acidic conditions, the Si—O—Si bond forming the skeleton of the silicone particles is usually in an equilibrium state between cleavage and bond formation. This equilibrium changes with temperature, and a higher molecular weight silicone core is more likely to be generated at lower temperatures. Therefore, in order to obtain a high molecular weight silicone core, it is preferable to perform aging by polymerizing by heating and then cooling to a polymerization temperature or lower. Specifically, the polymerization is carried out at 50 ° C. or higher, and the heating is stopped when the polymerization conversion rate reaches 75 to 90%, and it is cooled to 10 to 50 ° C., preferably 20 to 45 ° C., and about 5 to 100 hours. Aging can be performed.

  In addition, the polymerization conversion rate said here means the conversion rate to the (A-1) component of organosiloxane which is a raw material.

  There is no restriction | limiting in particular about the quantity of the water used for emulsion polymerization, What is necessary is just an amount required in order to carry out emulsification dispersion | distribution of various raw materials, and should just be 1-20 times amount (weight) with respect to the total amount of a normal raw material. .

  As the emulsifier used for the emulsion polymerization, any known emulsifier can be used without particular limitation as long as it does not lose the emulsifying ability in the pH range where the reaction is carried out. Examples of such emulsifiers include, for example, alkylbenzene sulfonic acid, sodium alkylbenzene sulfonate, sodium alkyl sulfate, sodium alkyl sulfosuccinate, sodium polyoxyethylene nonylphenyl ether sulfonate, and the like.

  Further, the amount of the emulsifier used is not particularly limited, and may be appropriately adjusted according to the particle size of the target silicone core. From the point that sufficient emulsifying ability is obtained and the physical properties of the obtained (A-1) component and the silicone polymer particles obtained from the component (A) are not adversely affected. It is preferable to use 005 to 20% by weight, and more preferably 0.05 to 10% by weight.

  The particle diameter of the component (A-1) can be controlled using a normal emulsion polymerization technique such as increase or decrease in the amount of emulsifier used. For example, a silicone core having a relatively small particle size can be stably obtained by carrying out emulsion polymerization using an alkylbenzene sulfonic acid at an appropriate concentration.

  The volume average particle size of the silicone particles is 0.01 μm to 1.0 μm, preferably 0.02 μm to 0.5 μm, and more preferably 0.04 μm to 0.4 μm. It is difficult to stably obtain particles having a volume average particle diameter of less than 0.01 μm, and if it exceeds 1.0 μm, the transparency and impact resistance of the final molded product may be deteriorated. In addition, the measurement of a volume average particle diameter can be performed using nano track particle size analyzer UPA150 (made by Nikkiso Co., Ltd.), for example.

  In the synthesis of the silicone core used in the present invention, a crosslinking agent and a graft crossing agent can be added as necessary.

  As the crosslinking agent that can be used for the synthesis of the silicone core of the present invention, for example, so-called trifunctionality including three functional groups that can participate in a condensation reaction such as methyltrimethoxysilane, phenyltrimethoxysilane, and ethyltriethoxysilane. Cross-linking agent, tetraethoxysilane, 1,3-bis [2- (dimethoxymethylsilyl) ethyl] benzene, 1,4-bis [2- (dimethoxymethylsilyl) ethyl] benzene, 1,3-bis [1- (dimethoxy) Methylsilyl) ethyl] benzene, 1,4-bis [1- (dimethoxymethylsilyl) ethyl] benzene, 1- [1- (dimethoxymethylsilyl) ethyl] -3- [2- (dimethoxymethylsilyl) ethyl] benzene 1- [1- (dimethoxymethylsilyl) ethyl] -4- [2-dimethoxymethylsilyl] So-called four-functional crosslinking agent 4 containing a functional group capable of participating in condensation reactions such as Le] benzene, and further may be mentioned oligomers by condensation of alkoxy groups of these crosslinking agents.

  These crosslinking agents can be used alone or in combination of two or more as required. The amount of the crosslinking agent added is preferably 10 parts by weight or less with respect to 100 parts by weight of the organosiloxane. When the addition amount of the crosslinking agent is more than 10 parts by weight, the flexibility of the silicone core is impaired, and the impact resistance at low temperature of the silicone composition may be lowered. Moreover, the elasticity of a silicone core can be arbitrarily adjusted by changing the crosslinking degree by adjusting the addition amount of a crosslinking agent.

  Examples of the grafting agent that can be used in the present invention include p-vinylphenylmethyldimethoxysilane, p-vinylphenylethyldimethoxysilane, 2- (p-vinylphenyl) ethylmethyldimethoxysilane, and 3- (p-vinylbenzoate). Iroxy) propylmethyldimethoxysilane, p-vinylphenylmethyldimethoxysilane, vinylmethyldimethoxysilane, tetravinyltetramethylcyclosiloxane, allylmethyldimethoxysilane, mercaptopropylmethyldimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, etc. It is done.

  The amount of the grafting agent used is preferably 10 parts by weight or less with respect to 100 parts by weight of the organosiloxane. When the amount of the grafting agent used is more than 10 parts by weight, the flexibility of the silicone core is impaired, and the impact resistance at low temperatures of the silicone composition may be lowered.

  In the present invention, the surface of the component (A-1) obtained as described above is coated with an alkoxysilane condensate so that the shell part of the silicone polymer particle (A) component [component (A-2)] To ensure compatibility between the component (A) and the component (B), and to uniformly disperse the component (A) in the silicone composition, or to improve the strength of the silicone composition. It is a component used for.

  The alkoxysilane condensate used in the present invention is obtained by condensing an alkoxysilane compound. Examples of the alkoxysilane compound include a monofunctional alkoxysilane compound represented by the following general formula (2), a bifunctional alkoxysilane compound represented by the general formula (3), and 3 represented by the general formula (4). Examples thereof include a functional alkoxysilane compound, a tetrafunctional alkoxysilane compound represented by the general formula (5), and a partial condensate thereof (an oligomer obtained by condensing an alkoxy group). These can be used alone or in combination of two or more.

In the general formula (2), R ¹² represents an alkyl group, and R ¹³ , R ¹⁴ , and R ¹⁵ represent the same or different monovalent organic groups.

In the general formula (3), R ²² and R ²³ represent the same or different alkyl groups, and R ²⁴ and R ²⁵ represent the same or different monovalent organic groups.

In the general formula (4), R ³² , R ³³ and R ³⁴ represent the same or different alkyl groups, and R ³⁵ represents the same or different monovalent organic groups.

In the general formula (5), R ⁴² , R ⁴³ , R ⁴⁴ and R ⁴⁵ represent the same or different alkyl groups.

Examples of the alkyl group mentioned in the general formulas (2) to (5) include a methyl group, an ethyl group, a propyl group, an isopropyl group, a normal butyl group, an isobutyl group, a secondary butyl group, a tertiary butyl group, An alkyl group having 1 to 6 carbon atoms such as a pentyl group and a hexyl group.
The monovalent organic group other than the alkyl group is a monovalent organic group other than an alkoxy group, such as an alkyl group having 1 to 10 carbon atoms (vinyl group, ethyl group, propyl group, butyl group, etc.), Examples thereof include alkenyl groups having 2 to 10 carbon atoms (vinyl group, allyl group, butenyl group, hexenyl group, etc.), aryl groups (phenyl group, naphthyl group, etc.), aralkyl groups (benzyl group, phenylethyl group) and the like.

  The alkoxysilane condensate which is the component (A-2) in the present invention can be obtained by condensation reaction of the above alkoxysilane compound, and specifically, a trifunctional alkoxysilane that can be expressed by the general formula (4). Hydrolyzed / condensed using a compound and / or a partial condensate thereof; hydrolyzed / condensed using a tetrafunctional alkoxysilane compound represented by the general formula (5) and / or a condensate thereof. A trifunctional alkoxysilane compound and / or its partial condensate that can be expressed by the general formula (4), and a tetrafunctional alkoxysilane compound and / or its partial condensate that can be expressed by the general formula (5) Preferred are those obtained by hydrolysis / condensation using a mixture of and at any ratio.

  The alkoxysilane condensate is a product obtained by hydrolysis / condensation using a monofunctional alkoxysilane compound that can be represented by the general formula (2) and / or a partial condensate thereof, in the general formula (3). Examples thereof include those obtained by hydrolysis and condensation using a bifunctional alkoxysilane compound that can be expressed and / or a partial condensate thereof.

  Moreover, the sum total of the part which consists of a trifunctional alkoxysilane compound and / or its partial condensate which can be represented by General formula (4), a tetrafunctional alkoxysilane compound and / or its condensate which can be represented by General formula (5) is (A-2) It is preferable to occupy 50% by weight or more of the entire component.

  Examples of the alkoxysilane compound used in the present invention include the same as the above-mentioned crosslinking agent and graft crossing agent. Of these alkoxysilane compounds, tetrafunctional alkoxysilanes or oligomers thereof are particularly inexpensive, and the resulting component (A-2) is preferred because of its high strength.

  The method for hydrolyzing and condensing the alkoxysilane compound is not particularly limited and may be a known method.

  As a polymerization method for obtaining the component (A-2) using an alkoxysilane compound, a method of emulsion polymerization of an alkoxysilane compound and the silicone particles can be used. Although general conditions can be applied for the emulsion polymerization, it is particularly preferable to pay attention to the polymerization temperature. The temperature during the polymerization is preferably 20 to 85 ° C, more preferably 30 to 75 ° C. The polymerization time is preferably 1 to 50 hours, more preferably 3 to 40 hours.

  The component (A-2) can be produced by a conventional emulsion polymerization method carried out under acidic or basic conditions, but the reaction under acidic conditions is more effective than the reaction under alkaline conditions. This is advantageous because it is easy to suppress gelation during the condensation reaction of silane.

  The method for separating the silicone polymer as component (A) obtained by emulsion polymerization from the latex is not particularly limited. For example, a metal salt such as calcium chloride, magnesium chloride or magnesium sulfate is added to the latex. The method of coagulating, separating, washing with water, dehydrating and drying the latex can be used. A spray drying method can also be used.

  In the present invention, the component (A) can be separated from the latex, and then can be uniformly dispersed in the matrix resin such as the component (B), and a transparent composition is obtained. It is preferable to use a masterbatch method from the point that can be achieved. The masterbatch method here refers to the addition of alcohols (methanol, ethanol, 2-propanol, etc.) and ketones (methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.) to the latex solution, thereby releasing the emulsion state of the particles. After the particles are gently agglomerated, the precipitate obtained by centrifugal sedimentation is redissolved in an appropriate solvent (toluene, xylene, hexane, etc.) and then mixed with the matrix resin (B), and the solvent is distilled off. It is a method to make it.

  In the present invention, the obtained silicone polymer particles are surface-treated. By performing the surface treatment, the affinity between the component (A) and the component (B) can be improved. Also, in order to reduce silanol groups from the surface of the component (A), which inhibit the curing reaction due to the hydrosilylation reaction between the component (B) and the organohydrogenpolysiloxane which is the component (C) and the hydrosilylation catalyst. The surface treatment is preferably performed.

  As the surface treating agent used at this time, a neutral silylating agent is used because surface treatment can be performed safely and efficiently. The neutral silylating agent herein may be any agent that proceeds in the vicinity of neutrality, and examples thereof include alkoxysilanes such as N, O-bis (trimethylsilyl) acetamide, trimethylmethoxysilane, and trimethylethoxysilane. . A silylating agent such as trimethylchlorosilane, dimethyldichlorosilane, hexamethyldisiloxane, or hexamethyl (di) silazane may be used. These surface treatment agents can be used alone or in combination of two or more. The amount of the surface treatment agent added is preferably 2 to 1000 parts by weight and more preferably 10 to 400 parts by weight with respect to 100 parts by weight of the component (A). If the addition amount of the surface treatment agent is less than 2 parts by weight, the affinity between the component (A) and the component (B) cannot be sufficiently improved, or the silanol groups on the surface of the component (A) are sufficiently reduced. I can't. Moreover, when there are more addition amounts than 1000 weight part, the surface treating agent which could not react with the silanol group of the (A) component surface may mix in in a composition as an impurity.

  The surface treatment may be performed by mixing a surface treatment agent in the latex solution containing the component (A), or dissolving the component (A) separated from the latex by the separation method in an appropriate solvent. Or after mixing with the surface treatment agent as it is.

<(B) Polyorganosiloxane having at least one alkenyl group in the molecule>
The polyorganosiloxane having at least one alkenyl group in the molecule as the component (B) used in the present invention is, for example, represented by the following average composition formula (6).
R ¹ _n SiO _{(4-n) / 2} (6)
(In the formula, R ¹ is the same or different unsubstituted or substituted monovalent hydrocarbon group, and n is a positive number of 1.98 to 2.02.)
Here, R ¹ in the above formula is an alkyl group such as a methyl group, an ethyl group, a propyl group or a butyl group, a cycloalkyl group such as a cyclohexyl group, an alkenyl group such as a vinyl group, an allyl group, a butenyl group or a hexenyl group, An aryl group such as a phenyl group, a tolyl group, or the like, or a chloromethyl group, a trifluoropropyl group, a cyanoethyl group, or the like in which some or all of hydrogen atoms bonded to carbon atoms of these groups are substituted with a halogen atom, a cyano group, It is the same or different selected, preferably an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms. Among these, a methyl group, a phenyl group, and a vinyl group are preferable from the viewpoint of heat resistance.

In this case, R ¹ needs to have at least one aliphatic unsaturated group (alkenyl group), but the content of the alkenyl group in R ¹ is 0.001 to 20 mol%, particularly 0. It is preferably 0.025 to 5 mol%. The component (B) represented by the above formula (6) is basically preferably linear, but may be one or a mixture of two or more having different molecular structures such as branched or cyclic. .

  Furthermore, the component (B) has a viscosity that is easy to handle and an average degree of polymerization of 50 to 10,000, preferably 100 to 3,000, from the viewpoint of availability. Is more preferable.

  About content of (A) component and (B) component, ratio ((A) / (B)) of (A) component and (B) component in a silicone type composition is 2 / 98-50 / 50. It is preferable that If this ratio is greater than 50/50, the transparency may decrease, and if it is less than 2/98, the strength improvement effect may be insufficient.

<(C) Organohydrogenpolysiloxane>
The silicone composition of the present invention contains an organohydrogenpolysiloxane as the component (C). As the organohydrogenpolysiloxane, a known one can be used. For example, if it contains at least two hydrogen atoms directly bonded to silicon atoms in one molecule, it is linear, branched, Any of cyclic forms may be used, but those having a polymerization degree of 300 or less are preferred from the viewpoint of availability. Specifically, a disilicone end-capped with a dimethylhydrogensilyl group, a copolymer of a dimethylsiloxane unit, a methylhydrogensiloxane unit and a terminal trimethylsiloxy unit, a dimethylhydrogensiloxane unit (H (CH ₃ )) ₂ SiO _0.5 units) and a low viscosity fluid composed of SiO ₂ units, 1,3,5,7-tetrahydrogen-1,3,5,7-tetramethylcyclotetrasiloxane, 1-propyl-3,5, Examples include 7-trihydrogen-1,3,5,7-tetramethylcyclotetrasiloxane and 1,5-dihydrogen-3,7-dihexyl-1,3,5,7-tetramethylcyclotetrasiloxane. Can be done.

  The addition amount of the organohydrogenpolysiloxane is such that the hydrogen atom directly bonded to the silicon atom is 50 to 500 mol%, preferably 100 to 200 mol% with respect to the alkenyl group of the component (B). desirable.

<(D) Hydrosilylation catalyst>
The silicone composition of the present invention contains a hydrosilylation catalyst as the component (D). As the hydrosilylation catalyst, for example, a platinum catalyst, a palladium catalyst, or a rhodium catalyst can be added. As the platinum-based catalyst, known ones can be used, specifically, platinum element alone, platinum compound, platinum complex, chloroplatinic acid, alcohol compound of chloroplatinic acid, aldehyde compound, ether compound, various olefins. Examples include complexes. The addition amount of the platinum-based catalyst is preferably in the range of 1 to 2,000 ppm as platinum atoms in the silicone-based composition.

<Other ingredients>
In addition to the above essential components, the silicone composition of the present invention is cured for the purpose of improving the storage stability of the silicone composition of the present invention or adjusting the reactivity of the hydrosilylation reaction during the curing process. A retarder can be used. Known curing retarders can be used, and specific examples include compounds containing aliphatic unsaturated bonds, organic phosphorus compounds, organic sulfur compounds, nitrogen-containing compounds, tin compounds, and organic peroxides. . These may be used alone or in combination of two or more.

  Examples of the compound containing an aliphatic unsaturated bond include propargyl such as 3-hydroxy-3-methyl-1-butyne, 3-hydroxy-3-phenyl-1-butyne and 1-ethynyl-1-cyclohexanol. Examples thereof include alcohols, en-in compounds, maleic acid esters such as maleic anhydride and dimethyl maleate. Examples of the organophosphorus compound include triorganophosphine, diorganophosphine, organophosphon, and triorganophosphite. Examples of organic sulfur compounds include organomercaptans, diorganosulfides, hydrogen sulfide, benzothiazole, thiazole, benzothiazole disulfide, and the like. Examples of tin compounds include stannous halide dihydrate, stannous carboxylate, and the like. Examples of the organic peroxide include di-t-butyl peroxide, dicumyl peroxide, benzoyl peroxide, and t-butyl perbenzoate.

  Among these curing retarders, benzothiazole, thiazole, dimethyl maleate, 3,5-dimethyl-1-hexyn-3-ol, 3-methyl-from the viewpoint of good retarding activity and good raw material availability 1-butyn-3-ol and 1-ethynyl-1-cyclohexanol are preferred.

The addition amount of the curing retarder is not particularly limited, but is preferably used in the range of 10 ⁻¹ to 10 ³ mol, more preferably in the range of 1 to 100 mol, with respect to 1 mol of the hydrosilylation catalyst. preferable. Moreover, these hardening retarders may be used independently and may be used in combination of 2 or more types.

In addition, silica may be added to the silicone composition of the present invention as an optional component as long as the object of the present invention is not impaired. That the silica be those which can be added in order to obtain a good composition of mechanical strength, a powder, a specific surface area of 50 m ² / g or more, further in the range of 100 to 300 m ² / g Is more preferable. If the specific surface area is less than 50 m ² / g, the mechanical strength of the cured product tends to be low. Examples of such reinforcing silica include fumed silica, precipitated silica, fused silica, silica obtained by hydrophobizing the surface of these silicas, and the like.

  The amount of the silica added is preferably 5 to 70 parts by weight, particularly preferably 10 to 50 parts by weight, based on 100 parts by weight of the component (B). If the addition amount of silica is less than 5 parts by weight, the addition amount may be too small to obtain a reinforcing effect, and if it exceeds 70 parts by weight, the workability deteriorates and the mechanical strength and transparency are lowered. There is a case.

  In addition, fillers such as pulverized quartz, calcium carbonate, and carbon may be added as a bulking agent as necessary within a range not impeding the effects of the present invention.

In addition, various additives such as a colorant and a heat resistance improver, a reaction control agent, a mold release agent, a dispersant for a filler, and the like may be optionally added to the silicone composition of the present invention as necessary. it can.
Examples of the filler dispersant include diphenylsilane diol, various alkoxysilanes, carbon functional silane, silanol group-containing low molecular weight siloxane, and the like.

In order to make the silicone composition of the present invention flame retardant and fire resistant, known additives such as titanium dioxide, manganese carbonate, Fe ₂ O ₃ , ferrite, mica, glass fiber, and glass flakes are added. May be. In addition, it is preferable to stop these arbitrary components to the minimum addition amount so that the effect of this invention may not be impaired.

  In the silicone composition of the present invention, the above components are mixed uniformly using a kneader such as a two-roll, Banbury mixer, kneader or a planetary stirring and defoaming machine, and heat-treated as necessary. Can be obtained.

  The silicone composition of the present invention can be used as a molded article. Examples of molding include arbitrary molding methods such as extrusion molding, compression molding, blow molding, calendar molding, vacuum molding, foam molding, injection molding, and cast molding.

  The silicone composition of the present invention can be used as a composition for optical materials. The optical material mentioned here refers to general materials used for the purpose of allowing light such as visible light, infrared light, ultraviolet light, X-rays, and lasers to pass through the material.

  More specifically, peripheral materials for liquid crystal display devices such as substrate materials, light guide plates, prism sheets, deflector plates, retardation plates, viewing angle correction films, adhesives, and films for liquid crystals such as polarizer protective films in the field of liquid crystal displays Is exemplified. In addition, color PDP (plasma display) sealants, antireflection films, optical correction films, housing materials, front glass protective films, front glass substitute materials, adhesives, and LED displays that are expected as next-generation flat panel displays LED element mold material used in the device, front glass protective film, front glass substitute material, adhesive, substrate material for plasma addressed liquid crystal (PALC) display, light guide plate, prism sheet, deflector plate, retardation plate, Viewing angle correction film, adhesive, polarizer protective film, front glass protective film in organic EL (electroluminescence) display, front glass substitute material, adhesive, and various film substrates and front glass in field emission display (FED) Protective films, front glass substitute material, adhesives.

  In the optical recording field, VD (video disc), CD / CD-ROM, CD-R / RW, DVD-R / DVD-RAM, MO / MD, PD (phase change disc), disc substrate material for optical cards, Examples include pickup lenses, protective films, sealants, and adhesives.

  In the field of optical equipment, examples include still camera lens materials, viewfinder prisms, target prisms, viewfinder covers, and light receiving sensor sections. In addition, a photographing lens and a viewfinder of a video camera are exemplified. Moreover, the projection lens of a projection television, a protective film, a sealing agent, an adhesive agent, etc. are illustrated. Examples are materials for lenses of optical sensing devices, sealants, adhesives, and films.

  In the field of optical components, fiber materials, lenses, waveguides, element sealants, adhesives and the like around optical switches in optical communication systems are exemplified. Examples include optical fiber materials, ferrules, sealants, adhesives and the like around the optical connector. Examples of optical passive components and optical circuit components include lenses, waveguides, LED element sealants, adhesives, and the like. Examples include substrate materials, fiber materials, element sealants, adhesives, and the like around an optoelectronic integrated circuit (OEIC).

  In the field of optical fibers, examples include sensors for industrial use such as lighting and light guides for decorative displays, displays and signs, and optical fibers for communication infrastructure and for connecting digital devices in the home.

  Examples of the semiconductor integrated circuit peripheral material include resist materials for microlithography for LSI and VLSI materials.

  In the field of automobiles and transport equipment, automotive lamp reflectors, bearing retainers, gear parts, anti-corrosion coatings, switch parts, headlamps, engine internal parts, electrical parts, various interior and exterior parts, drive engines, brake oil tanks, automobile protection Examples include rusted steel plates, interior panels, interior materials, protective / bundling wireness, fuel hoses, automobile lamps, and glass substitutes. Moreover, the multilayer glass for rail vehicles is illustrated. Further, examples thereof include a toughness imparting agent for aircraft structural materials, engine peripheral members, wireness for protection and binding, and corrosion-resistant coating.

  In the construction field, interior / processing materials, electrical covers, sheets, glass interlayers, glass substitutes, and solar cell peripheral materials are exemplified. In agriculture, a house covering film is exemplified.

  Next-generation DVDs, organic EL element peripheral materials, organic photorefractive elements, light-amplifying elements that are light-to-light conversion devices, optical arithmetic elements, substrate materials around organic solar cells, etc. Examples thereof include fiber materials, element sealants, and adhesives.

  EXAMPLES Next, although this invention is demonstrated further in detail based on an Example, this invention is not limited only to these Examples. In addition, the test method of the physical property of a silicone type composition is as follows.

<Test method>
(Tensile properties (mechanical strength))
According to the method described in JIS K7113, measurement was performed using an autograph AG-10TB type manufactured by Shimadzu Corporation. Measurement was performed at n = 3, and the average values of strength (MPa) and elongation (%) when the test piece was broken were adopted. The test piece had a shape of 2 (1/3) and a thickness of 2 mm. The test was conducted at 23 ° C. and a test speed of 500 mm / min. The test piece used was conditioned at a temperature of 23 ± 2 ° C. and a relative humidity of 50 ± 5% for 24 hours or more before the test.
(Curing property)
Transparency was evaluated by measuring the haze (turbidity) and light transmittance in air of a test piece having a thickness of 3 mm with NDH-300A manufactured by Nippon Denshoku Industries Co., Ltd.

(Example 1)
300 parts by weight of pure water was placed in a four-necked flask equipped with a stirrer, reflux condenser, monomer addition port, and thermometer. Separately from this, a mixture of 100 parts by weight of pure water, 0.5 part by weight (solid content) of a 15% by weight aqueous solution of sodium dodecylbenzenesulfonate, and 100 parts by weight of octamethylcyclotetrasiloxane at 8000 rpm with a homomixer. After forced emulsification for 5 minutes, it was added all at once. After stirring for 5 minutes, 1 part by weight (solid content) was added as a 10% by weight aqueous solution of dodecylbenzenesulfonic acid, and after stirring for another 15 minutes, the system was heated to 80 ° C. After reaching 80 ° C., stirring was continued for 360 minutes, and then the system was cooled to 25 ° C. and aged for 20 hours to obtain a latex containing silicone core particles.

In a five-necked flask equipped with a stirrer, reflux condenser, nitrogen inlet, monomer addition port, and thermometer, 80.0 parts by weight (solid content) of the above-mentioned silicone core particles were charged, and the temperature was raised to 40 ° C. in a nitrogen atmosphere. Allowed to warm. Separately, 50 parts by weight of pure water and 0.1 part by weight (solid content) of 5% by weight aqueous solution of sodium dodecylbenzenesulfonate, ethyl silicate condensate (trade name: ethyl silicate 40, SiO, manufactured by Tama Chemical Industry Co., Ltd.) ₂ content: 39.0 to 42.0% by weight) 24.8 parts by weight (corresponding to 10.0 parts by weight in terms of a complete condensate of the structural unit represented by SiO ₂ ), trimethoxymethylsilane 20 After forcibly emulsifying a mixture of ₃ parts by weight (corresponding to 10.0 parts by weight in terms of a complete condensate of the structural unit represented by CH ₃ SiO _3/2 ) with a homomixer at 8000 rpm for 5 minutes, Added dropwise over 60 minutes. This solution was stirred for 24 hours while being kept at 40 ° C. to obtain a latex containing silicone polymer particles (volume average particle size 0.17 μm) as component (A).

  Subsequently, after adding 180 parts by weight of methyl ethyl ketone to 20 parts by weight of the resin solid content of the latex containing the component (A) (resin solid content concentration: 22% by weight), the particles are aggregated, and then centrifuged at 6000 rpm, 20 Centrifuged for 1 minute. The obtained precipitate was dispersed in a mixed solvent of methyl ethyl ketone / methanol = 1/1 (vol / vol) and washed, and then centrifuged with a centrifuge at 6000 rpm for 20 minutes. After performing this washing 10 times in total, 380 parts by weight of toluene was added to 20 parts by weight of the resulting precipitate to obtain a toluene solution of component (A).

  Furthermore, in a four-necked flask equipped with a rubber septum for reagent addition, a nitrogen blowing port, a Dimroth cooler equipped with a nitrogen blowing port, a thermometer, and a magnetic stirrer, 400 parts by weight of the toluene solution of the above component (A) (Of which 20 parts by weight of resin solid content) was charged, and 10.9 parts by weight of N, O-bis (trimethylsilyl) acetamide was added dropwise with stirring at 40 ° C. By stirring this solution at 40 ° C. for 2 hours and at room temperature for 2 hours, a toluene solution of the component (A) in which silanol groups on the surface of the particles were surface-treated to become methyl groups was obtained.

  The solution after the reaction was washed 10 times with 400 parts by weight of pure water. Next, 100 parts by weight of DMS-V31 manufactured by Gelest Co., which is a terminal vinyl polydimethylsiloxane, was blended with 20 parts by weight of the resin solid content of this solution, and this mixture was concentrated by a rotary evaporator to distill off toluene. Thereafter, 4.4 parts by weight of Grest HMS-301, a methylhydrogensiloxane-dimethylsiloxane copolymer, and 0.012 parts by weight (solid content) of a 10% by weight xylene solution of dimethyl maleate were added, and platinum vinylsiloxane was further added. 0.55 parts by weight of a xylene solution of the complex (containing 0.03% by weight as platinum) was added, and the mixture was stirred and defoamed with a vacuum stirring deaerator. This mixture was poured into a mold and heated in air at 180 ° C. for 30 minutes, so that the component (A) in which silanol groups on the surface of the particles were surface-treated to become methyl groups was blended by a so-called master batch method. A transparent silicone-based cured product having a thickness of 3 mm was obtained. Transparency and tensile properties were measured using the obtained cured product. The results are shown in Table 1.

(Comparative Example 1)
300 parts by weight of pure water was placed in a four-necked flask equipped with a stirrer, reflux condenser, monomer addition port, and thermometer. Separately from this, a mixture of 100 parts by weight of pure water, 0.5 part by weight (solid content) of a 15% by weight aqueous solution of sodium dodecylbenzenesulfonate, and 100 parts by weight of octamethylcyclotetrasiloxane at 8000 rpm with a homomixer. After forced emulsification for 5 minutes, it was added all at once. After stirring for 5 minutes, 1 part by weight (solid content) was added as a 10% by weight aqueous solution of dodecylbenzenesulfonic acid, and after stirring for another 15 minutes, the system was heated to 80 ° C. After reaching 80 ° C., stirring was continued for 360 minutes, and then the system was cooled to 25 ° C. and aged for 20 hours to obtain a latex containing silicone core particles.

In a five-necked flask equipped with a stirrer, reflux condenser, nitrogen inlet, monomer addition port, and thermometer, 80.0 parts by weight (solid content) of the above-mentioned silicone core particles were charged, and the temperature was raised to 40 ° C. in a nitrogen atmosphere. Allowed to warm. Separately, 50 parts by weight of pure water and 0.1 part by weight (solid content) of 5% by weight aqueous solution of sodium dodecylbenzenesulfonate, ethyl silicate condensate (trade name: ethyl silicate 40, SiO, manufactured by Tama Chemical Industry Co., Ltd.) ₂ content: 39.0 to 42.0% by weight) 24.8 parts by weight (corresponding to 10.0 parts by weight in terms of a complete condensate of the structural unit represented by SiO ₂ ), trimethoxymethylsilane 20 After forcibly emulsifying a mixture of ₃ parts by weight (corresponding to 10.0 parts by weight in terms of a complete condensate of the structural unit represented by CH ₃ SiO _3/2 ) with a homomixer at 8000 rpm for 5 minutes, Added dropwise over 60 minutes. This solution was stirred for 24 hours while being kept at 40 ° C. to obtain a latex containing silicone polymer particles (volume average particle size 0.17 μm) as component (A).

  Subsequently, after adding 180 parts by weight of methyl ethyl ketone to 20 parts by weight of the resin solid content of the latex containing the component (A) (resin solid content concentration: 22% by weight), the particles are aggregated, and then centrifuged at 6000 rpm, 20 Centrifuged for 1 minute. The obtained precipitate was dispersed in a mixed solvent of methyl ethyl ketone / methanol = 1/1 (vol / vol) and washed, and then centrifuged with a centrifuge at 6000 rpm for 20 minutes. After performing this washing 10 times in total, 380 parts by weight of toluene was added to 20 parts by weight of the resulting precipitate to obtain a toluene solution of component (A).

  Furthermore, in a four-necked flask equipped with a rubber septum for adding a reagent, a nitrogen blowing port, a nitrogen blowing port, a thermometer, and a magnetic stirrer, 400 parts by weight of the toluene solution of the component (A) (of which the resin solid content is 20 Parts by weight) and 8.0 parts by weight of chlorotrimethylsilane was added dropwise with stirring at room temperature. By stirring this solution at room temperature for 4 hours, a toluene solution of the component (A) in which silanol groups on the surface of the particles were surface-treated to become vinyl groups was obtained.

  The solution after the reaction was washed 10 times with 400 parts by weight of pure water. Next, 100 parts by weight of DMS-V31 manufactured by Gelest Co., which is a terminal vinyl polydimethylsiloxane, was blended with 20 parts by weight of the resin solid content of this solution, and this mixture was concentrated by a rotary evaporator to distill off toluene. Thereafter, 4.4 parts by weight of Grest HMS-301, a methylhydrogensiloxane-dimethylsiloxane copolymer, and 0.012 parts by weight (solid content) of a 10% by weight xylene solution of dimethyl maleate were added, and platinum vinylsiloxane was further added. 0.55 parts by weight of a xylene solution of the complex (containing 0.03% by weight as platinum) was added, and the mixture was stirred and defoamed with a vacuum stirring deaerator. This mixture was poured into a mold and heated in air at 180 ° C. for 30 minutes, so that the component (A) in which silanol groups on the surface of the particles were surface-treated to become methyl groups was blended by a so-called master batch method. A transparent silicone-based cured product having a thickness of 3 mm was obtained. Transparency and tensile properties were measured using the obtained cured product. The results are shown in Table 1.

(Comparative Example 2)
100 parts by weight of DMS-V31 from Gerest, which is a terminal vinyl polydimethylsiloxane, 4.4 parts by weight of HMS-301 from Gerest, which is a methylhydrogensiloxane-dimethylsiloxane copolymer, and 10% by weight xylene of dimethyl maleate Add 0.012 parts by weight (solid content) of the solution, and then add 0.55 parts by weight of a platinum vinylsiloxane complex xylene solution (containing 0.03% by weight of platinum) and stir and remove with a vacuum stirring deaerator. Foam was done. The mixture was poured into a mold and heated in air at 180 ° C. for 30 minutes to obtain a transparent silicone-based cured product having a thickness of 3 mm. Transparency and tensile properties were measured using the obtained cured product. The results are shown in Table 1.

As described above, the silicone polymer particles surface-treated with N, O-bis (trimethylsilyl) acetamide, which is the component (A) obtained by the present invention, have a high tensile strength in the silicone composition, and Compared with the silicone composition (Comparative Example 1) using the silicone polymer particles surface-treated with trimethylchlorosilane, a more transparent composition can be provided.

Claims (7)

  (A-1) A silicone core-alkoxysilane condensate shell structure in which (A-2) an alkoxysilane condensate shell part is coated on a silicone particle having a volume average particle size of 0.01 to 1.0 μm. Silicone polymer particles having a surface treated with a neutral silylating agent. The silicone particles as the component (A-1) are represented by the general formula (1).
R _m SiO _{(4-m) / 2} (1)
Wherein R is a substituted or unsubstituted monovalent hydrocarbon group, each of which may be the same or different, and is represented by m in the above general formula (1). The structural unit of = 2 occupies 80 mol% or more of the total component (A-1), the silicone-based polymer particles according to claim 1.   The silicone polymer particle according to claim 1 or 2, wherein the silicone particle as component (A-1) is an organosiloxane having a silanol group at the end of the molecule.   The (A) component is coated with 5 to 90% by weight of the alkoxysilane condensate shell part (A-2) with respect to 10 to 95% by weight of the core part of the silicone particles (A-1). The silicone polymer particle according to any one of claims 1 to 3, wherein the silicone polymer particle is a polymer. In the alkoxysilane condensate shell part which is the component (A-2), the portion composed of the following component (a) and / or the following component (b) occupies 50% by weight or more of the total component (A-2). The silicone polymer particle according to any one of claims 1 to 4, wherein the silicone polymer particle is characterized by the following.
(A) Component: General formula (4)

(Wherein R ³² , R ³³ and R ³⁴ represent the same or different monovalent organic groups, and R ³⁵ represents a monovalent organic group) and / or Its partial condensate,
(B) Component: General formula (5)

(Wherein R ⁴² , R ⁴³ , R ⁴⁴ and R ⁴⁵ represent the same or different monovalent organic groups) and / or a partial condensate thereof.   (A) The silicone polymer particle according to any one of claims 1 to 5, (B) a polyorganosiloxane having at least one alkenyl group in the molecule, (C) an organohydrogenpolysiloxane, (D And) a hydrosilylation catalyst. The silicone composition according to claim 6, wherein the component (A) is uniformly dispersed in the composition by a masterbatch method.