Antistatic silicone rubber composition

Abstract

The present invention relates to an antistatic silicone rubber composition comprising at least one potassium salt selected from the group consisting of potassium alkylphosphate, potassium bis(trialkylsilyl)amide, potassium dialkylamide, potassium sulfate, potassium phenoxide, and potassium permanganate in an amount of about 0.1 to about 15% by weight of the composition. The composition comprises: (A) an organopolysiloxane having at least two silicon-bonded alkenyl groups per molecule; (B) an organopolysiloxane having at least two silicon-bonded hydrogen atoms per molecule; (C) a hydrosilylation reaction catalyst; and (D) at least one potassium salt of the above. The composition exhibits good curability and cures to form a silicone rubber with excellent antistatic properties.

Description

[Technical field]

[0001] The present invention relates to an antistatic silicone rubber composition. [Background technology]

[0002] Silicone rubber has been used in various applications by making full use of its excellent heat resistance, cold resistance, and electrical properties. Such silicone rubber is generally provided in the form of a silicone rubber composition containing an organopolysiloxane and a reinforcing filler. Reinforcing fillers such as organopolysiloxane and silica are insulators, and silicone rubber compositions produced by mixing such reinforcing fillers and silicone rubbers obtained by curing such compositions become charged with static electricity when they come into contact with various substances. Due to such static charge, the silicone rubber attracts dust suspended in the air.

[0003] Antistatic silicone rubber has been produced using hydrosilylation-curable silicone rubber compositions containing potassium salts such as KBF4, KClO4, KPF6, KAsF6, KSbF6, KSO3CF3, KN(SO2CF3)2, KN(SO2C4F9)2, KSO3C4F9, KC(SO2CF3)3, KB(C6H5)2, and KN(SO2CF2)2CF2 (see Patent Document 1), and hydrosilylation-curable silicone rubber compositions containing lithium salts such as LiBF4, LiClO4, LPF6, LiAsF6, LiSbF6, LiSO3CF3, LiN(SO2CF3)2, LiSO3C4F9, LiC(SO2CF3)3, and LiB(C6H5)2 (see Patent Document 2). However, the use of such potassium salts and lithium salts has the problem of being catalytic poisons for the hydrosilylation reaction catalyst in the composition, and therefore it has not been possible to sufficiently cure at relatively low temperatures. [Prior art documents] [Patent documents]

[0004] Patent Document 1: China Patent Application Publication No. 103421323(A)

[0005] Patent Document 2: Korean Patent Application Publication No. 10-2006-0092088(A) Summary of the Invention [Problem to be solved by the invention]

[0006] It is an object of the present invention to provide an antistatic silicone rubber composition that exhibits good curing properties at relatively low temperatures and cures to form a silicone rubber that exhibits excellent antistatic properties. [Means for solving the problem]

[0007] The antistatic silicone rubber composition of the present invention contains at least one potassium salt selected from the group consisting of potassium alkylphosphate, potassium bis(trialkylsilyl)amide, potassium dialkylamide, potassium sulfate, potassium phenoxide, and potassium permanganate in an amount of about 0.1 to about 15% by weight of the composition.

[0008] Potassium alkyl phosphates have the following general formula: [ka] Potassium monoalkyl phosphate represented by The general formula: [ka] Potassium dialkyl phosphate represented by and the following general formula: [ka] At least one component selected from the group consisting of potassium dialkyl pyrophosphates represented by Here, R in the formula 1are the same or different alkyl groups having 1 to 12 carbon atoms, X are the same or different and are a potassium atom or a hydrogen atom, and at least one X is a potassium atom.

[0009] In various embodiments, the antistatic silicone rubber compositions of the present invention can be cured by a hydrosilylation reaction. Such compositions include: (A) an organopolysiloxane having at least two alkenyl groups bonded to silicon atoms in each molecule; (B) an organopolysiloxane having at least two silicon-bonded hydrogen atoms in each molecule, the content of silicon-bonded hydrogen atoms in this component being in an amount of about 0.1 to about 10 moles per mole of silicon-bonded alkenyl groups in component (A); (C) a hydrosilylation reaction catalyst in an amount sufficient to cure the composition; (D) at least one potassium salt selected from the group consisting of potassium alkylphosphate, potassium bis(trialkylsily)amide, potassium dialkylamide, potassium sulfate, potassium phenoxide, and potassium permanganate, in an amount of about 0.1 to about 15% by weight of the composition.

[0010] In certain embodiments, the composition further comprises: (E) a hydrosilylation reaction inhibitor in an amount from about 0.001 to about 1% by weight of the composition.

[0011] The composition is useful as a rubber mold-making material.

[0012] The antistatic silicone rubber of the present invention is obtained by curing the antistatic silicone rubber composition. 10 ~about 10 12 It has a surface resistivity of Ω / sq. Effect of the Invention

[0013] The antistatic silicone rubber composition of the present invention exhibits good curing properties at relatively low temperatures and can be cured to form a silicone rubber that exhibits excellent antistatic properties. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] definition

[0015] The terms "comprising or comprise" are used herein in their broadest sense to mean and encompass "including or include," "consist(ing) essentially of," and "consist(ing) of." "For example," "eg," "such as," and "including" are used only to list examples and are not limited thereto. Thus, "for example" or "such as" means "for example, but not limited to" or "such as, but not limited to," and includes other similar or equivalent examples. As used herein, the term "about" serves to reasonably encompass or account for slight variations in numerical values ​​as determined by instrumental analysis or as a result of handling samples. Such slight variations may be on the order of ±0-25%, ±0-10%, ±0-5%, or ±0-2.5% of the numerical value. Furthermore, the term "about" applies to both numerical values ​​when relating to a range of values. Furthermore, the term "about" may apply to numerical values ​​even if not expressly stated.

[0016] Generally, as used herein, a hyphen or dash in a range of values ​​means "to" or "through," ">" means "above" or "greater-than," "≧" means "at least" or "greater-than or equal to," "<" means "below" or "less-than," and "≦" means "at most" or "less-than or equal to." Each of the foregoing patent applications, patents, and / or patent publications is expressly incorporated herein in its entirety in one or more non-limiting embodiments on an individual basis.

[0017] It should be understood that the scope of the appended claims is not limited to the expressions and specific compounds, compositions or methods described in the detailed description, which may vary among the specific embodiments within the scope of the appended claims. With respect to any Markush group relied upon herein describing detailed features or aspects of various embodiments, it should be understood that different, special, and / or unexpected results can be obtained from each element of the respective Markush group independent of all other Markush elements. Each element of the Markush group may be relied upon individually and / or in combination to adequately describe a specific embodiment within the scope of the appended claims.

[0018] Any ranges and subranges relied upon in describing various embodiments of the present invention should also be understood to be within the scope of the appended claims, both individually and inclusively, and all ranges including integer and / or fractional values ​​are understood to be described and contemplated, even if such values ​​are not expressly written herein. Those skilled in the art will readily recognize that the recited ranges and subranges fully describe and enable various embodiments of the present invention, and that such ranges and subranges may be further delineated into relevant halves, thirds, fourths, fifths, etc. As merely an example, a range of "0.1-0.9" may be further delineated into a lower third, i.e., 0.1-0.3, a middle third, i.e., 0.4-0.6, and an upper third, i.e., 0.7-0.9, which are individually and inclusively within the scope of the appended claims and may be relied upon individually and / or inclusively to fully support a particular embodiment within the scope of the appended claims. Furthermore, with respect to words defining or modifying a range, such as "at least," "greater than," "less than," "less than," etc., such words should be understood to include subranges and / or upper or lower limits. As another example, the range "at least 10" essentially includes subranges of at least 10 to 35, at least 10 to 25, 25 to 35, etc., each of which may be relied upon individually and / or inclusively to fully support certain embodiments within the scope of the appended claims. Finally, individual numbers within the disclosed ranges may be relied upon to fully support certain embodiments within the scope of the appended claims. For example, the range "1 to 9" includes various individual integers, such as 3, as well as individual numbers (or fractions) including decimal points, such as 4.1, which may be relied upon to fully support certain embodiments within the scope of the appended claims.

[0019] (Embodiments of the present invention) <Antistatic Silicone Rubber Composition>

[0020] First, the antistatic silicone rubber composition of the present invention will be described in detail. In various embodiments, the antistatic silicone rubber composition comprises at least one potassium salt selected from the group consisting of potassium alkyl phosphate, potassium bis(trialkylsilyl)amide, potassium dialkylamide, potassium sulfate, potassium phenoxide, and potassium permanganate in an amount of about 0.1 to about 15% by mass of the composition.

[0021] The potassium alkyl phosphate is preferably, but not limited to, represented by the following general formula: [ka] Potassium monoalkyl phosphate represented by The general formula: [ka] Potassium dialkyl phosphate represented by and the following general formula: [ka] The at least one component selected from the group consisting of potassium dialkyl pyrophosphates represented by the formula:

[0022] In the formula, R 1 are the same or different and are alkyl groups having 1 to 12 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a neopentyl group, a hexyl group, a cyclohexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, and a dodecyl group, and the most common is a hexyl group.

[0023] In the formula, X may be the same or different and is a potassium atom or a hydrogen atom, and at least one X is a potassium atom.

[0024] In potassium bis(trialkylsilyl)amide, the alkyl group is preferably, but not limited to, R 1 Examples of the alkyl group include alkyl groups having 1 to 12 carbon atoms.

[0025] In the potassium dialkylamide, the alkyl group is preferably, but not limited to, R 1 Examples of the alkyl group include alkyl groups having 1 to 12 carbon atoms.

[0026] In various embodiments, the amount of potassium salt is from about 0.1 to about 15%, optionally from about 0.1 to about 10%, or optionally from about 0.5 to about 10% by weight of the composition. When the potassium salt content is at or above the lower limit of the above range, the resulting silicone rubber has excellent antistatic properties, whereas when it is at or below the upper limit of the above range, the resulting silicone rubber composition is believed to have good curability.

[0027] In various embodiments, the potassium salt is added to the silicone rubber composition using a polyol, which can be used to introduce the potassium salt into the silicone rubber composition, thereby imparting both antistatic and mechanical properties to the resulting silicone rubber.

[0028] Examples of polyols include polypropylene glycol, copolymers of propylene glycol and various polyalkylene glycols, or various polyester polyols. Among these, polypropylene glycol is particularly preferred because it can impart high levels of both antistatic properties and mechanical properties to the resulting silicone rubber. The weight average molecular weight of the polyol used in the present invention is preferably about 100 to about 5,000, or about 300 to about 4,000.

[0029] The amount of polyol used is preferably from about 5 to about 90% by mass, alternatively from about 5 to about 80% by mass, or alternatively from about 5 to about 70% by mass, of the total amount of the potassium salt and the polyol.

[0030] Examples of the curing system of the composition include, but are not limited to, a hydrosilylation reaction, a condensation reaction, ultraviolet irradiation, and a radical reaction with an organic peroxide, and the curing system is generally a hydrosilylation reaction.

[0031] The hydrosilylation-curable silicone rubber composition comprises: (A) an organopolysiloxane having at least two alkenyl groups bonded to silicon atoms in each molecule; (B) an organopolysiloxane having at least two silicon-bonded hydrogen atoms in each molecule, the content of silicon-bonded hydrogen atoms in this component being in an amount of about 0.1 to about 10 moles per mole of silicon-bonded alkenyl groups in component (A); (C) a hydrosilylation reaction catalyst in an amount sufficient to cure the composition; (D) at least one potassium salt selected from the group consisting of potassium alkylphosphate, potassium bis(trialkylsily)amide, potassium dialkylamide, potassium sulfate, potassium phenoxide, and potassium permanganate, in an amount of about 0.1 to about 15% by weight of the composition.

[0032] Component (A) is an organopolysiloxane having at least two alkenyl groups bonded to silicon atoms in one molecule. Examples of the alkenyl group include alkenyl groups having 2 to 12 carbon atoms, such as vinyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, and dodecenyl groups, and among these, vinyl groups are preferred. Further, examples of groups bonded to silicon atoms other than alkenyl groups in component (A) include alkyl groups having 1 to 12 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl; aryl groups having 6 to 20 carbon atoms, such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups having 7 to 20 carbon atoms, such as benzyl, phenethyl, and phenylpropyl; and groups in which some or all of the hydrogen atoms in the above groups are substituted with halogen atoms, such as fluorine, chlorine, or bromine. Furthermore, the silicon atoms in component (A) may have a small amount of hydroxyl or alkoxy groups, such as methoxy or ethoxy groups, within a range that does not impair the object of the present invention.

[0033] Examples of the molecular structure of component (A) include a linear structure, a partially branched linear structure, a branched structure, a cyclic structure, and a three-dimensional network structure. Component (A) may be one of organopolysiloxanes having these molecular structures, or a mixture of two or more organopolysiloxanes having these molecular structures.

[0034] Examples of such component (A) include dimethylpolysiloxanes capped at both ends of the molecule with dimethylvinylsiloxy groups, dimethylsiloxane-methylvinylsiloxane copolymers capped at both ends of the molecule with dimethylvinylsiloxy groups, dimethylsiloxane-methylphenylsiloxane copolymers capped at both ends of the molecule with dimethylvinylsiloxy groups, methylphenylpolysiloxanes capped at both ends of the molecule with dimethylvinylsiloxy groups, dimethylsiloxane-methylvinylsiloxane copolymers capped at both ends of the molecule with trimethylsiloxy groups, and dimethylsiloxane-methylvinylsiloxane copolymers capped at both ends of the molecule with trimethylsiloxy groups. Examples of the polymerizable compound include a capped dimethylsiloxane-methylvinylsiloxane-methylphenylsiloxane copolymer, a mixture of a dimethylpolysiloxane capped at both ends with a dimethylvinylsiloxy group and a dimethylpolysiloxane capped at one end with a dimethylvinylsiloxy group and the other end with a dimethylhydroxysiloxy group, a mixture of a dimethylpolysiloxane capped at both ends with a dimethylvinylsiloxy group and a dimethylpolysiloxane capped at both ends with a dimethylhydroxysiloxy group, and a combination of two or more of these.

[0035] Component (B) is an organopolysiloxane having at least two hydrogen atoms bonded to silicon atoms in one molecule. Examples of groups bonded to silicon atoms other than hydrogen groups in component (B) include alkyl groups having 1 to 12 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl; aryl groups having 6 to 20 carbon atoms, such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups having 7 to 20 carbon atoms, such as benzyl, phenethyl, and phenylpropyl; and groups in which some or all of the hydrogen atoms in the above groups are replaced with halogen atoms, such as fluorine, chlorine, or bromine. Furthermore, the silicon atoms in component (B) may have small amounts of hydroxyl groups or alkoxy groups, such as methoxy groups or ethoxy groups, provided this does not impair the object of the present invention.

[0036] Examples of the molecular structure of component (B) include a linear structure, a linear structure having some branches, a branched chain, a cyclic structure, and a three-dimensional network structure. Preferably, the molecular structure is a linear structure, a linear structure having some branches, a branched chain, or a three-dimensional network structure.

[0037] Examples of such component (B) include methylhydrogenpolysiloxane capped at both ends of the molecule with trimethylsiloxy groups, dimethylsiloxane-methylhydrogensiloxane copolymer capped at both ends of the molecule with trimethylsiloxy groups, dimethylpolysiloxane capped at both ends of the molecule with dimethylhydrogensiloxy groups, dimethylsiloxane-methylhydrogensiloxane copolymer capped at both ends of the molecule with dimethylhydrogensiloxy groups, methylhydrogensiloxane-diphenylsiloxane copolymer capped at both ends of the molecule with trimethylsiloxy groups, methylhydrogensiloxane-diphenylsiloxane-dimethylsiloxane copolymer capped at both ends of the molecule with trimethylsiloxy groups, (CH3)2HSiO.1 / 2 Units and SiO 4 / 2 A copolymer consisting of the units (CH3)2HSiO 1 / 2 Units and SiO 4 / 2 Units and (C6H5)SiO 3 / 2 units, as well as mixtures of two or more of these.

[0038] The content of component (B) is 0.1 to 10 moles, preferably 0.5 to 5 moles, of hydrogen atoms bonded to silicon atoms in this component per mole of alkenyl groups bonded to silicon atoms in component (A).This is because when the content of component (B) is equal to or less than the upper limit of the above range, the mechanical strength of the cured product is good, whereas when the content of component (B) is equal to or more than the lower limit of the above range, the curability of the composition is good.

[0039] Component (C) is a hydrosilylation catalyst used to accelerate the curing of the composition. Examples of component (C) include platinum group element catalysts and platinum group element compound catalysts, and specific examples include platinum-based catalysts, rhodium-based catalysts, palladium-based catalysts, and combinations of at least two of these. In particular, platinum-based catalysts are preferred because they can dramatically accelerate the curing of the composition. Examples of these platinum catalysts include platinum fine powder, platinum black, chloroplatinic acid, alcohol-modified chloroplatinic acid, chloroplatinic acid / diolefin complex, platinum / olefin complex, platinum / carbonyl complex such as platinum bis(acetoacetate) and platinum bis(acetylacetonate), chloroplatinic acid / alkenylsiloxane complex such as chloroplatinic acid / divinyltetramethyldisiloxane complex and chloroplatinic acid / tetravinyltetramethylcyclotetrasiloxane complex, platinum / alkenylsiloxane complex such as platinum / divinyltetramethyldisiloxane complex and platinum / tetravinyltetramethylcyclotetrasiloxane complex, complex of chloroplatinic acid and acetylene alcohol, and mixture of two or more of these.In particular, platinum-alkenylsiloxane complex is preferred because it can accelerate the curing of the present composition.

[0040] Examples of alkenylsiloxanes used in the platinum-alkenylsiloxane complex include 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, alkenylsiloxane oligomers in which a portion of the methyl groups of the alkenylsiloxane is substituted with an ethyl group, a phenyl group, etc., and alkenylsiloxane oligomers in which the vinyl groups of the alkenylsiloxane are substituted with an allyl group, a hexenyl group, etc. In particular, 1,3-divinyl-1,1,3,3-tetramethyldisiloxane is preferred in that the platinum-alkenylsiloxane complex produced has good stability.

[0041] In order to improve the stability of the platinum-alkenylsiloxane complexes, it is preferable to dissolve these platinum-alkenylsiloxane complexes in an organosiloxane oligomer such as an alkenylsiloxane oligomer, such as 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, 1,3-diallyl-1,1,3,3-tetramethyldisiloxane, 1,3-divinyl-1,3-dimethyl-1,3-diphenyldisiloxane, 1,3-divinyl-1,1,3,3-tetraphenyldisiloxane, or 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, or a dimethylsiloxane oligomer, and it is particularly preferable to dissolve the complexes in an alkenylsiloxane oligomer.

[0042] The content of component (C) is an amount such that the platinum group metal in this component is 0.01 to 1,000 ppm in mass units based on the present composition. Specifically, the content is preferably an amount such that the platinum group metal in component (C) is in the range of 0.01 to 500 ppm, or 0.1 to 100 ppm in mass units based on the present composition. This is because when the content of component (C) is equal to or higher than the lower limit of the above range, the curability of the composition is good, whereas when the content of component (C) is equal to or lower than the upper limit of the above range, coloration of the cured product is suppressed.

[0043] Component (D) is at least one potassium salt selected from the group consisting of potassium alkylphosphate, potassium bis(trialkylsilyl)amide, potassium dialkylamide, potassium sulfate, potassium phenoxide, and potassium permanganate. Examples of such component (D) include the above-mentioned components.

[0044] The content of component (D) is 0.1 to 15% by mass of the composition, and preferably 0.1 to 10% by mass, or 0.5 to 10% by mass of the composition. When the content of component (D) is at or above the lower limit of the above range, the resulting cured product has excellent antistatic properties, whereas when the content is at or below the upper limit of the above range, the resulting curable silicone composition is believed to have good curability.

[0045] The composition may contain (E) a hydrosilylation reaction inhibitor to extend the working time at ambient temperature and enhance storage stability. Examples of component (E) include acetylene alcohols such as 1-ethynyl-cyclohexan-1-ol, 2-methyl-3-butyn-2-ol, 2-phenyl-3-butyn-2-ol, 2-ethynyl-isopropan-2-ol, 2-ethynyl-butan-2-ol, and 3,5-dimethyl-1-hexyn-3-ol; silylated acetylene alcohols such as trimethyl(3,5-dimethyl-1-hexyn-3-oxy)silane, dimethyl-bis-(3-methyl-1-butyn-oxy)silane, methylvinylbis(3-methyl-1-butyn-3-oxy)silane, and ((1,1-dimethyl-2-propynyl)oxy)trimethylsilane; diallyl maleate, dimethyl maleate, diethyl fumarate, and the like. unsaturated carboxylic acid esters such as bis(2-methoxy-1-methylethyl)maleate, mono-octyl maleate, mono-isooctyl maleate, mono-allyl maleate, mono-methyl maleate, mono-ethyl fumarate, mono-allyl fumarate, and 2-methoxy-1-methylethyl maleate; ene-yne ​​compounds such as 2-isobutyl-1-buten-3-yne, 3,5-dimethyl-3-hexen-1-yne, 3-methyl-3-penten-1-yne, 3-methyl-3-hexen-1-yne, 1-ethynylcyclohexene, 3-ethyl-3-buten-1-yne, and 3-phenyl-3-buten-1-yne; and mixtures of two or more thereof.

[0046] The content of component (E) is not limited, but is preferably 1 to 10,000 ppm in the component in mass units based on the composition. Specifically, the content is preferably 1 to 5,000 ppm, or 10 to 5,000 ppm in the component in mass units based on the composition. This is because when the content of component (E) is equal to or greater than the lower limit of the above range, the storage stability of the composition is good, whereas when the content of component (E) is equal to or less than the upper limit of the above range, the curing property of the composition at low temperatures is good.

[0047] The composition may contain a polyol (F) for introducing component (D) into the composition. Examples of polyols of component (F) include polypropylene glycol, copolymers of propylene glycol and various polyalkylene glycols, or various polyester polyols. Among these, polypropylene glycol is particularly preferred because it can impart high levels of both antistatic properties and mechanical properties to the resulting silicone rubber. The weight average molecular weight of the polyol used in the present invention is preferably about 100 to about 5,000, or about 300 to about 4,000. The content of component (F) is not limited, but is preferably about 5 to about 90% by weight, or about 5 to about 80% by weight, or about 5 to about 70% by weight of the total amount of components (D) and (F).

[0048] The composition may contain an organosiloxane (G) that does not have an alkenyl group and a hydrogen atom bonded to a silicon atom in the molecule. Examples of the group bonded to a silicon atom in the component (G) include alkyl groups having 1 to 12 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl; aryl groups having 6 to 20 carbon atoms, such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups having 7 to 20 carbon atoms, such as benzyl, phenethyl, and phenylpropyl; and groups in which some or all of the hydrogen atoms in the above groups are replaced with halogen atoms, such as fluorine, chlorine, or bromine. Furthermore, the silicon atoms in component (G) may have small amounts of hydroxyl groups or alkoxy groups, such as methoxy groups or ethoxy groups, provided this does not impair the object of the present invention.

[0049] Examples of the molecular structure of component (G) include a linear structure, a linear structure having some branches, a branched chain, a cyclic structure, and a three-dimensional network structure. Preferably, the molecular structure is a linear structure having some branches, a branched chain, or a three-dimensional network structure.

[0050] Examples of such component (G) include dimethylsiloxane capped at both ends of the molecule with trimethylsiloxy groups, dimethylsiloxane capped at both ends of the molecule with dimethylhydroxysiloxy groups, methylphenylsiloxane capped at both ends of the molecule with trimethylsiloxy groups, a dimethylsiloxane-methylphenylsiloxane copolymer capped at both ends of the molecule with trimethylsiloxy groups, and mixtures of two or more of these.

[0051] The content of component (G) is not limited, but is preferably about 1 to about 100 parts by mass, or about 5 to about 100 parts by mass, or about 1 to about 50 parts by mass, per 100 parts by mass of component (A).This is because when the content of component (G) is equal to or higher than the lower limit of the above range, the viscosity of the composition can be reduced, and when the content of component (G) is equal to or lower than the upper limit of the above range, the mechanical properties of the obtained silicone rubber are improved.

[0052] The composition may contain reinforcing and / or non-reinforcing fillers (H). Examples of fillers include finely divided treated or untreated precipitated silica, or fumed silica, precipitated or ground calcium carbonate, zinc carbonate, clays such as finely divided kaolin, quartz powder, aluminum hydroxide, zirconium silicate, diatomaceous earth, wollastonite, pyrophylate, and one or more of metal oxides such as fumed or precipitated titanium dioxide, cerium oxide, magnesium oxide powder, zinc oxide, iron oxide, etc. They may also include glass fibers, talc, aluminite, calcium sulfate (anhydrite), gypsum, calcium sulfate, magnesium carbonate, magnesium hydroxide (brucite), graphite, barite, which is a form of barium sulfate, copper carbonates such as malachite, nickel carbonates such as zarachite, barium carbonates such as witherite, strontium carbonates such as strontianite, or similar inorganic fillers.

[0053] The content of component (H) is not limited, but is preferably about 1 to about 200 parts by mass, or about 5 to about 150 parts by mass, or about 10 to about 150 parts by mass, per 100 parts by mass of component (A).This is because when the content of component (H) is equal to or higher than the lower limit of the above range, the heat resistance and mechanical properties of the resulting silicone rubber can be improved, and when the content of component (H) is equal to or lower than the upper limit of the above range, the viscosity of the composition can be reduced.

[0054] The antistatic silicone rubber composition of the present invention can be prepared by combining all the components at ambient temperature. Any of the mixing techniques and equipment described in the prior art can be used for this purpose. The specific equipment used will depend on the viscosity of the components and the final curable composition. It may be desirable to cool the components during mixing to avoid premature curing.

[0055] The antistatic silicone rubber composition of the present invention is particularly useful as a rubber material for molding.

[0056] <Antistatic silicone rubber>

[0057] Next, the antistatic silicone rubber of the present invention will be described in detail. In various embodiments, the antistatic silicone rubber is obtained by curing the above-mentioned antistatic silicone rubber composition. The shape of the silicone rubber is not particularly limited, and examples include a sheet shape and a film shape. In various embodiments, the silicone rubber is about 10 10 ~about 10 12 It has a surface resistivity of Ω / sq. EXAMPLES

[0058] The antistatic silicone rubber composition of the present invention will now be described using examples and comparative examples. It should be noted that the viscosity values ​​are values ​​obtained at 25° C. The properties of the antistatic silicone rubber composition and the antistatic silicone rubber are evaluated as follows.

[0059] <Viscosity>

[0060] Viscosity is measured using a rotational viscometer such as a Brookfield Synchro-Lectric Viscometer or a Wells-Brookfield 52 cone / plate viscometer. Since virtually all materials measured are non-Newtonian in nature, no correlation should be expected between results obtained using different spindles (cones) or speeds. Results are generally obtained in centipoise and converted to viscosity (mPa s). Viscosity was measured at 0.5 rpm and 5.0 rpm for 2 minutes. The method is based on ASTM D4287 for cone / plate.

[0061] <Hardness of the cured product>

[0062] The low-temperature curing silicone composition was cured in an oven at 80°C for 1 hour to obtain a cured product having a thickness of 6 mm. The hardness of the cured product was then measured using Shore A hardness in accordance with ASTM D2240 "Standard Test Method for Rubber Property-Durometer Hardness".

[0063] <Measurement of Charge>

[0064] The surface resistance of the molded article was measured by a surface resistance meter, SURPA-385. The measuring instrument measures the electrostatic discharge of conductive and insulating surfaces. The equipment complies with the ASTM D257 test method using parallel bar sensing.

[0065] Test procedure: A standard size specimen (145mm x 145mm square plate with a thickness of 2mm) is cured in an oven at 80°C for 1 hour and then cooled to room temperature. The article is placed between two electrodes. A voltage is applied for 60 seconds and the resistance is measured. The surface resistivity is measured and a value is obtained from the instrument. The surface resistivity is expressed in ohms per unit area.

[0066] <Examples 1 to 4 and Comparative Examples 1 to 3>

[0067] Antistatic silicone rubber compositions of Examples 1 to 4 and Comparative Examples 1 to 3 were prepared by uniformly mixing the following components according to the composition (parts by mass) shown in Table 1. In Table 1, the "SiH / alkenyl ratio" indicates the total moles of hydrogen atoms bonded to silicon atoms in component (B) per mole of total alkenyl groups in component (A) of the antistatic silicone rubber composition. The content of component (C) is expressed as the platinum metal content (ppm by mass) relative to the content of the antistatic silicone rubber composition, and the content of component (E) is expressed as the content (ppm by mass) relative to the content of the antistatic silicone rubber composition.

[0068] The following components were used as component (A):

[0069] Component (a-1): Dimethylpolysiloxane with a viscosity of 2,000 mPa s, both ends of which are capped with dimethylvinylsiloxy groups (vinyl group content: 0.23% by mass)

[0070] Component (a-2): Dimethylsiloxane-methylhexenylsiloxane copolymer with a viscosity of 420 mPa s, both ends of which are capped with dimethylhexenylsiloxy groups (hexenyl group content: 2.0% by mass)

[0071] The following components were used as component (B):

[0072] Component (b-1): Dimethylpolysiloxane with a viscosity of 10 mPa·s, both ends of which are capped with dimethylhydrogensiloxy groups (content of hydrogen atoms bonded to silicon atoms: 0.16% by mass)

[0073] Component (b-2): Dimethylsiloxane methylhydrogensiloxane copolymer with a viscosity of 5 mPa·s, both ends of which are capped with trimethylsiloxy groups (content of hydrogen atoms bonded to silicon atoms: 0.76% by mass)

[0074] The following components were used as component (C):

[0075] Component (c-1): Platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex solution in 1,3-divinyl-1,1,3,3-tetramethyldisiloxane (containing 0.06% by mass of platinum in the solution)

[0076] The following components were used as component (D):

[0077] Component (d-1): Potassium alkyl phosphate represented by the following formula.

[0078] [ka]

[0079] The following components were used as comparisons for component (D):

[0080] Component (d-2): LiPF6

[0081] Component (d-3): LiClO4

[0082] The following components were used as component (E):

[0083] Component (e-1): 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane

[0084] The following components were used as component (F):

[0085] Component (f-1): Polypropylene glycol with an average molecular weight of 446

[0086] The following component was used as component (G):

[0087] Component (g-1): Dimethylpolysiloxane with a viscosity of 5 mPa·s, with both ends of the molecule capped with trimethylsiloxy groups.

[0088] The following components were used as component (H):

[0089] Component (h-1): BET specific surface area is 175m 2 / g, and silica fine powder surface-treated with hexamethyldisilazane

[0090] Component (h-2): Zirconium silicate fine powder with an average particle size of 5 μm

[0091] [Table 1]

[0092] The antistatic silicone compositions shown in Comparative Examples 2 and 3 did not cure for 1 hour at 80° C. They were heated at 150° C. for 1 hour, but the composition shown in Comparative Example 2 did not cure, and the composition shown in Comparative Example 3 did not cure completely. [Industrial Applicability]

[0093] The antistatic silicone rubber composition of the present invention exhibits good curing properties at relatively low temperatures and cures to form a silicone rubber exhibiting excellent antistatic properties, and is therefore suitable as a sealant, protective coating agent, adhesive, etc. for electric / electronic devices.

Claims

1. An antistatic silicone rubber composition comprising at least one potassium salt selected from the group consisting of potassium alkyl phosphates in an amount of 5.0 to 15% by weight of the composition, and which cures via a hydrosilylation reaction.

2. 2. The antistatic silicone rubber composition of claim 1, wherein the potassium alkyl phosphate is represented by the following general formula: 【Chemistry 1】 Potassium monoalkyl phosphate represented by The general formula: 【Chemistry 2】 Potassium dialkyl phosphate represented by and the following general formula: 【Chemistry 3】 At least one component selected from the group consisting of potassium dialkyl pyrophosphates represented by Here, R in the formula １ are the same or different alkyl groups having 1 to 12 carbon atoms, X are the same or different and are potassium atoms or hydrogen atoms, and at least one X is a potassium atom.

3. 2. The antistatic silicone rubber composition according to claim 1, (A) an organopolysiloxane having at least two alkenyl groups bonded to silicon atoms in each molecule; (B) an organopolysiloxane having at least two silicon-bonded hydrogen atoms in each molecule, the content of silicon-bonded hydrogen atoms in this component being 0.1 to 10 moles per mole of silicon-bonded alkenyl groups in component (A); (C) a hydrosilylation reaction catalyst in an amount sufficient to cure the composition; (D) an antistatic silicone rubber composition comprising at least one potassium salt selected from the group consisting of potassium alkyl phosphates in an amount of 5.0 to 15% by weight of said composition.

4. 4. The antistatic silicone rubber composition according to claim 3, (E) an antistatic silicone rubber composition further comprising a hydrosilylation reaction inhibitor in an amount of 0.001 to 1 weight percent of said composition.

5. The antistatic silicone rubber composition according to claim 1, which is used as a rubber material for molding.

6. An antistatic silicone rubber obtained by curing the antistatic silicone rubber composition according to any one of claims 1 to 4.

7. 10 １０ ~10 １２ 7. The antistatic silicone rubber according to claim 6, having a surface resistivity of Ω / sq.

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