Room temperature-curable organopolysiloxane composition and article

Abstract

The present invention provides a room temperature-curable organopolysiloxane composition comprising, at a specific ratio, (A) an organopolysiloxane in which one or both terminals of a molecular chain thereof are capped with a silanol group, (B) an organic silicon compound represented by formula (1) (where R1 is a monovalent hydrocarbon group excluding an aliphatic unsaturated bond, R2 is a hydrogen atom or an aliphatic unsaturated monovalent hydrocarbon group, R3 is a monovalent hydrocarbon group excluding an aliphatic unsaturated bond, A is a divalent hydrocarbon group, k is 0-2, m is 3-6, k+m is 3-8, and n is 0-100), and (C) a deamidated silane represented by formula (2) (where R4 is a methyl group, a vinyl group, or a phenyl group, and R5 is a methyl group, an ethyl group, or a phenyl group). This organopolysiloxane composition can be a cured product which exhibits excellent storage stability and which has low hardness and high elongation properties.

Description

Room temperature curable organopolysiloxane compositions and articles

[0001] The present invention relates to a room-temperature-curable organopolysiloxane composition that provides a cured product with low hardness and high elongation, in particular a room-temperature-curable organopolysiloxane composition that contains a curable organopolysiloxane as a main component (base polymer) and an organosilicon compound having a specific molecular structure (a silanol group-containing polyfunctional cyclic organopolysiloxane compound) and that provides an organopolysiloxane elastomer elastic body (a silicone rubber cured product) with improved storage stability, as well as coating agents, adhesives, and sealants that contain the composition, and articles that are coated, bonded, or sealed with a cured product of the composition.

[0002] Conventionally, condensation-curable room-temperature-curable organopolysiloxane compositions and the like have been known as room-temperature-curable resin compositions that undergo a condensation reaction with moisture (humidity) in the air at room temperature (23°C ± 15°C) to crosslink and cure to give elastomer elastic bodies (cured rubber products). These room-temperature-curable organopolysiloxane compositions are widely used in the fields of construction, transportation, electrical and electronic components, etc., due to their safety and excellent durability and adhesive properties as rubber.

[0003] Among room-temperature-curable organopolysiloxane compositions, so-called one-component (single-liquid) room-temperature-curable organopolysiloxane compositions do not require the complicated weighing and mixing of a base polymer, crosslinking agent, catalyst, etc. immediately before use, and are therefore free from the risk of formulation errors. In addition, they generally exhibit excellent adhesion to a wide range of substrates even when a primer is not used, and are therefore widely used as elastic adhesives and coating agents in the electrical and electronics industries and as building sealants.

[0004] Such one-component room-temperature-curable organopolysiloxane compositions are classified according to the type of compound released from the composition upon contact with moisture in the air, with representative examples including deacetic acid-, deoxime-, deamido-, dehydroxylamine-, deacetone-, and dealcohol-type organopolysiloxane compositions. Among these, for example, deoxime-type organopolysiloxane compositions that cure by releasing oxime are characterized by excellent storage stability and the ability to produce excellent cured coatings in a short period of time, while dealcohol-type organopolysiloxane compositions that cure by releasing alcohol have properties such as low odor, no corrosion of metals such as copper and iron, excellent self-adhesion (adhesion to various substrates after curing when no primer is used), and excellent adhesion durability, and are used in fields that make the most of their respective characteristics.

[0005] However, it is known that one-component room-temperature-curable organopolysiloxane compositions generally contain an excess amount of crosslinking agent in consideration of storage stability, making it difficult to obtain a cured product with low hardness and high elongation.

[0006] Deamidated and dehydroxylamine-type organopolysiloxane compositions have long been known as a method for achieving low hardness and high elongation properties in one-component room-temperature-curable organopolysiloxane compositions (Patent Document 1: JP-B-52-030020). However, dehydroxylamine-type organopolysiloxane compositions are primarily useful as two-component room-temperature-curable organopolysiloxane compositions, and as one-component room-temperature-curable organopolysiloxane compositions, they have storage stability issues due to the cleavage of the siloxane bonds in the organopolysiloxane. Furthermore, deamidated-type organopolysiloxane compositions, while containing a deamidated crosslinking agent as the primary crosslinking agent providing chain extension, also have storage stability issues due to the inclusion of a polyfunctional dehydroxylamine-type crosslinking agent in part to form a crosslinked structure, and so further methods have been sought.

[0007] Special Publication No. 52-030020

[0008] The present invention has been made in view of the above circumstances, and has as its object the provision of a room-temperature-curable organopolysiloxane composition, particularly a condensation-curable room-temperature-curable organopolysiloxane composition (a so-called condensation-curable RTV silicone rubber composition), which provides an organopolysiloxane elastomer elastic body (cured silicone rubber product) that has good storage stability and physical properties such as low hardness and high elongation, as well as coating agents, adhesives, and sealants containing said composition, and articles coated, bonded, or sealed with a cured product of said composition.

[0009]

[0005] As a result of intensive research aimed at achieving the above object, the present inventors have discovered that by blending a room-temperature-curable organopolysiloxane composition with an organosilicon compound represented by the following formula (1) as a crosslinking agent and a deamidated silane represented by the following formula (2) as a deamidated crosslinking agent with a chain-extending effect, the composition can be cured to produce a low-hardness, high-elongation cured product. Furthermore, they have found that with this composition, a good rubber cured product can be obtained even without the use of a polyfunctional dehydroxylamine-type crosslinking agent, and that the shelf life of the room-temperature-curable organopolysiloxane composition is greatly improved, leading to the completion of the present invention.

[0010] That is, the present invention provides the following room-temperature-curable organopolysiloxane composition, as well as coating agents, adhesives, and sealants containing the composition, and articles coated, bonded, or sealed with a cured product of the composition: [1] (A) 100 parts by mass of an organopolysiloxane having both molecular chain terminals and / or one terminal blocked with silanol groups, (B) 0.01 to 50 parts by mass of an organosilicon compound represented by the following formula (1), and (In the formula, R 1 are independently unsubstituted or substituted monovalent hydrocarbon groups having 1 to 12 carbon atoms excluding aliphatic unsaturated bonds, and R 2 is a hydrogen atom or an aliphatic unsaturated monovalent hydrocarbon group having 2 to 12 carbon atoms, and R 3are independently unsubstituted or substituted monovalent hydrocarbon groups having 1 to 12 carbon atoms excluding aliphatic unsaturated bonds, A is a divalent hydrocarbon group having 2 to 8 carbon atoms, k is an integer of 0 to 2, m is an integer of 3 to 6, k+m is an integer of 3 to 8, and n is an integer of 0 to 100.) (C) a deamidated silane represented by the following formula (2): 1 to 20 parts by mass (In the formula, R 4 are independently a methyl group, a vinyl group, or a phenyl group, and R 5 are independently a methyl group, an ethyl group, or a phenyl group. [2] The room-temperature-curable organopolysiloxane composition according to [1], further comprising the following components (D) and / or (E) per 100 parts by mass of the component (A): (D) filler: 1 to 1,000 parts by mass, (E) plasticizer: 1 to 1,000 parts by mass. [3] In the deamidated silane represented by formula (2), R 4 is a methyl group or a vinyl group, and R 5 wherein R is an ethyl group. [4] The room-temperature-curable organopolysiloxane composition according to any one of [1] to [3], characterized in that it does not contain a dehydroxylamine type silane compound. [5] A coating agent comprising the room-temperature-curable organopolysiloxane composition according to any one of [1] to [4]. [6] An adhesive comprising the room-temperature-curable organopolysiloxane composition according to any one of [1] to [4]. [7] A sealant comprising the room-temperature-curable organopolysiloxane composition according to any one of [1] to [4]. [8] An article having a coating layer comprising a cured product of the room-temperature-curable organopolysiloxane composition according to any one of [1] to [4]. [9] An article bonded and / or sealed with a cured product of the room-temperature-curable organopolysiloxane composition according to any one of [1] to [4].

[0011] In the present invention, the organosilicon compound defined by the above formula (1) is included in the present invention as long as the average structure of the organosilicon compound aggregate is within the above range, even if there are differences in structure between the individual organosilicon compounds.

[0012] According to the present invention, by containing a deamidation-type crosslinking agent having a chain-extending effect and an organosilicon compound having a specific molecular structure (a silanol group-containing polyfunctional cyclic organopolysiloxane compound), it is possible to obtain a room-temperature-curable organopolysiloxane composition that has good storage stability and gives a cured product with low hardness and high elongation.

[0013] The present invention will be described in detail below.

[0014] The room-temperature-curable organopolysiloxane composition of the present invention comprises an organosilicon compound (silanol group-containing polyfunctional cyclic organopolysiloxane compound) of component (B) below as an additive that forms a crosslinked structure, and a deamidated silane of component (C) below as a chain extender. In particular, it is a room-temperature-curable organopolysiloxane composition (a so-called condensation-curable RTV silicone rubber composition) that comprises, as a main component (base polymer), an organopolysiloxane of component (A) below, in which both and / or one molecular chain end is capped with silanol groups, an organosilicon compound of component (B) below, and a deamidated silane of component (C) below. More specifically, it is a condensation-curable room-temperature-curable organopolysiloxane composition that comprises components (A), (B), and (C) below, and, optionally, at least one selected from components (D) and (E).

[0015] Component (A) is an organopolysiloxane in which both and / or one molecular chain end is blocked with silanol groups, and serves as the base polymer of the room-temperature-curable organopolysiloxane composition of the present invention. It has at least one silanol group (hydroxyl group) bonded to a silicon atom in the molecule. The organopolysiloxane is preferably linear. Specifically, the organopolysiloxane is a diorganopolysiloxane in which both or one molecular chain end is blocked with a silanol group (hydroxyl group) bonded to a silicon atom, as represented by the following general formula (3) or (4): (In the formula, R 6are independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, X is an oxygen atom or a divalent hydrocarbon group having 1 to 8 carbon atoms, and p is a number that gives the diorganopolysiloxane a viscosity of 100 to 1,000,000 mPa·s at 23°C.

[0016] In the above formulas (3) and (4), R 6 The unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms represented by the formula (I) is preferably one excluding aliphatic unsaturated bonds, and examples thereof include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, and dodecyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; aryl groups such as phenyl, tolyl, xylyl, and α- and β-naphthyl; aralkyl groups such as benzyl, 2-phenylethyl, and 3-phenylpropyl; and groups in which some or all of the hydrogen atoms of these groups have been substituted with halogen atoms such as F, Cl, and Br, or with cyano groups, such as 3-chloropropyl, 3,3,3-trifluoropropyl, and 2-cyanoethyl. Among these, examples of R 6 As the alkyl group, a lower alkyl group such as a methyl group, an ethyl group, an isopropyl group, or a butyl group, or an aryl group such as a phenyl group is preferred, with a methyl group being particularly preferred.

[0017] In the above formulas (3) and (4), X is an oxygen atom or a divalent hydrocarbon group having 1 to 8 carbon atoms, and is —(CHCH) q - or -(CH=CH) q Preferably, it is one represented by - (q represents 1 to 4). Among these, an oxygen atom, -CH2CH2-, and -CH=CH- are particularly preferred.

[0018] In the above formulas (3) and (4), the difunctional diorganosiloxane unit ((SiR 6 2O 2 / 2)) is a number that results in a viscosity of the diorganopolysiloxane at 23°C of 100 to 1,000,000 mPa s, and is typically an integer of 50 or greater, preferably an integer of 100 to 2,000, more preferably an integer of 150 to 1,000, and particularly preferably an integer of 200 to 800.

[0019] In the present invention, the degree of polymerization (or molecular weight) can be determined, for example, as a polystyrene-equivalent number-average degree of polymerization (or number-average molecular weight) determined by gel permeation chromatography (GPC) analysis using toluene, tetrahydrofuran (THF), or the like as a developing solvent.

[0020] The organopolysiloxane of component (A) preferably has a viscosity at 23°C of 100 to 1,000,000 mPa·s, more preferably 300 to 500,000 mPa·s, particularly preferably 500 to 100,000 mPa·s, and especially preferably 1,000 to 80,000 mPa·s. If the organopolysiloxane has a viscosity of 100 mPa·s or higher, it is possible to obtain a cured product with excellent physical and mechanical strength. If the viscosity is 1,000,000 mPa·s or lower, the room-temperature-curable organopolysiloxane composition is easy to work with during use, which is preferable. In the present invention, the viscosity is a value measured using a rotational viscometer (e.g., BM type, BL type, BH type, BS type, cone-plate type, etc.).

[0021] The organopolysiloxane of component (A) can be used alone, or in combination of two or more types with different structures or molecular weights.

[0022] Component (B) is an organosilicon compound represented by the following formula (1), and is used as a crosslinking agent for the room-temperature-curable organopolysiloxane composition. (In the formula, R 1 are independently unsubstituted or substituted monovalent hydrocarbon groups having 1 to 12 carbon atoms excluding aliphatic unsaturated bonds, and R 2 is a hydrogen atom or an aliphatic unsaturated monovalent hydrocarbon group having 2 to 12 carbon atoms, and R 3are independently unsubstituted or substituted monovalent hydrocarbon groups having 1 to 12 carbon atoms excluding aliphatic unsaturated bonds, A is a divalent hydrocarbon group having 2 to 8 carbon atoms, k is an integer of 0 to 2, m is an integer of 3 to 6, k+m is an integer of 3 to 8, and n is an integer of 0 to 100.

[0023] Component (B) is an organosilicon compound (cyclic organopolysiloxane compound) represented by the above formula, and is a silanol group-containing polyfunctional cyclic organopolysiloxane compound having, via a divalent hydrocarbon group (A), 3 to 6 (i.e., m) diorganohydroxysilyl groups (i.e., when n = 0) or monovalent diorganosiloxanyl groups (i.e., when n = an integer from 1 to 100) having terminal silanol groups (hydroxy groups bonded to silicon atoms) as monovalent substituents (side chains) bonded to silicon atoms constituting the cyclic organopolysiloxane consisting of 3 to 8 (i.e., (k + m)) siloxane units.

[0024] Here, in the above formula (1), R 1 Examples of the unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms excluding aliphatic unsaturated bonds include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, and dodecyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; aryl groups such as phenyl, tolyl, xylyl, and α- and β-naphthyl; aralkyl groups such as benzyl, 2-phenylethyl, and 3-phenylpropyl; and groups in which some or all of the hydrogen atoms of these groups have been substituted with halogen atoms such as F, Cl, and Br, or with cyano groups, such as 3-chloropropyl, 3,3,3-trifluoropropyl, and 2-cyanoethyl. Among these, R 1 As the alkyl group, a lower alkyl group such as a methyl group, an ethyl group, an isopropyl group, or a butyl group, or an aryl group such as a phenyl group is preferred, with a methyl group or a phenyl group being particularly preferred.

[0025] In the above formula (1), R 2Among the hydrogen atoms or aliphatic unsaturated monovalent hydrocarbon groups having 2 to 12 carbon atoms, examples of the aliphatic unsaturated monovalent hydrocarbon groups having 2 to 12 carbon atoms include alkenyl groups such as vinyl group, allyl group, propenyl group, isopropenyl group, butenyl group, isobutenyl group, pentenyl group, hexenyl group, and cyclohexenyl group; and alkynyl groups such as ethynyl group (acetylenyl group) and ethynylmethyl group. 2 As the alkyl group, a hydrogen atom or an alkenyl group such as a vinyl group or an allyl group is preferred, with a hydrogen atom and a vinyl group being particularly preferred.

[0026] In the above formula (1), R 3 The unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms excluding an aliphatic unsaturated bond is 1 Examples of the alkyl group include the same groups as those exemplified in the above, such as 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 hexyl group, a heptyl group, an octyl group, a 2-ethylhexyl group, a nonyl group, a decyl group, and a dodecyl group; a cycloalkyl group such as a cyclopentyl group and a cyclohexyl group; an aryl group such as a phenyl group, a tolyl group, a xylyl group, and an α-, β-naphthyl group; an aralkyl group such as a benzyl group, a 2-phenylethyl group, and a 3-phenylpropyl group; and groups in which some or all of the hydrogen atoms of these groups have been substituted with a halogen atom such as F, Cl, or Br, or a cyano group, such as a 3-chloropropyl group, a 3,3,3-trifluoropropyl group, and a 2-cyanoethyl group. 3 As the alkyl group, a lower alkyl group such as a methyl group, an ethyl group, an isopropyl group, or a butyl group, or an aryl group such as a phenyl group is preferred, with a methyl group or a phenyl group being particularly preferred.

[0027] In the above formula (1), A is a divalent hydrocarbon group such as an alkylene group or an alkenylene group having 2 to 8 carbon atoms, preferably 2 to 4 carbon atoms, and the divalent hydrocarbon group is —(CH) p1 Preferred are alkylene groups such as - (p1 represents an integer of 2 to 8, preferably an integer of 2 to 4). Among these, -CH2CH2- and -CH2CH2CH2- are more preferred.

[0028] In the above formula (1), k is an integer of 0 to 2, preferably 0 or 1. In the above formula (1), m is an integer of 3 to 6, preferably 4 or 5. In the above formula (1), k+m is an integer of 3 to 8, preferably an integer of 4 to 6.

[0029] In the above formula (1), n ​​is an integer of 0 to 100, preferably an integer of 0 to 20, more preferably an integer of 0 to 10, and even more preferably an integer of 0 to 4.

[0030] <Method for Producing Organosilicon Compound> The organosilicon compound represented by the above formula (1) of component (B) can be produced by a method including the following steps [I] or [II].

[0031] [I] The following formula (5) (In the formula, R 3 , n is the same as above) and an organohydrogensilane or organohydrogenpolysiloxane represented by the following formula (6): (In the formula, R 1 , k, m, k+m are the same as above, and R 2’ is an aliphatic unsaturated monovalent hydrocarbon group having 2 to 12 carbon atoms.

[0032] [II] Formula (7) below (In the formula, R 3 , n is the same as above, and R 2’ is an aliphatic unsaturated monovalent hydrocarbon group having 2 to 12 carbon atoms, and an organosilane or organopolysiloxane represented by the following formula (8): (In the formula, R 1 , k, m, and k+m are the same as above), in the presence of a platinum compound-containing catalyst, subjecting a cyclic organohydrogenpolysiloxane represented by the following formula (I) to a hydrosilylation addition reaction.

[0033] Specifically, an organohydrogensilane represented by the above formula (5) having a silanol group (a hydroxyl group bonded to a silicon atom) and a silicon-bonded hydrogen atom (a hydrosilyl group represented by SiH) in the molecule (when n = 0 in formula (5)) or an organohydrogenpolysiloxane having a silanol group at one end of the molecular chain and a silicon-bonded hydrogen atom at the other end of the molecular chain (when n = 1 to 100 in formula (5)) is used, and an aliphatic unsaturated monovalent hydrocarbon group (R 2’ ) in the presence of a platinum compound-containing catalyst, or by subjecting a cyclic organopolysiloxane having a silanol group and an aliphatic unsaturated monovalent hydrocarbon group (R 2’ ) (when n=0 in formula (7)) or an organosilane having an aliphatic unsaturated monovalent hydrocarbon group (R 2’ ), and a silanol group at the other end of the molecular chain (where n = 1 to 100 in formula (7)), and a cyclic organohydrogenpolysiloxane having silicon-bonded hydrogen atoms represented by formula (8) are subjected to a hydrosilylation addition reaction in the presence of a platinum compound-containing catalyst to form an aliphatic unsaturated monovalent hydrocarbon group (R 2’ ) to form a carbon-silicon bond (i.e., the silicon-bonded hydrogen atom (SiH group) in the above formula (5) and the aliphatic unsaturated monovalent hydrocarbon group (R 2’ ), or an addition reaction between a silicon-bonded hydrogen atom (SiH group) in the above formula (8) and an aliphatic unsaturated monovalent hydrocarbon group (R 2’ ) to form a divalent hydrocarbon group such as an alkylene group and / or an alkenylene group represented by A in formula (1), thereby producing an organosilicon compound represented by formula (1).

[0034] Here, in the above formulas (6) and (7), R 2’The aliphatic unsaturated monovalent hydrocarbon group having 2 to 12 carbon atoms represented by the formula (1) is 2 Among these, the same groups as those exemplified as the aliphatic unsaturated monovalent hydrocarbon groups having 2 to 12 carbon atoms can be mentioned. 2’ As the alkyl group, a vinyl group, an alkenyl group such as an allyl group, etc. is preferred, and a vinyl group is particularly preferred.

[0035] Specific examples of the organohydrogensilane or organohydrogenpolysiloxane represented by the above formula (5) include those shown below. (wherein n is the same as above.)

[0036] Specific examples of the cyclic organopolysiloxane represented by the above formula (6) include those shown below.

[0037] Specific examples of the organosilane or organopolysiloxane represented by the above formula (7) include those shown below. (wherein n is the same as above.)

[0038] Specific examples of the cyclic organohydrogenpolysiloxane represented by the above formula (8) include those shown below.

[0039] The reaction ratio of the organohydrogensilane or organohydrogenpolysiloxane represented by formula (5) with the cyclic organopolysiloxane represented by formula (6) is preferably such that 0.5 to 1.5 mol, and more preferably 0.7 to 1.4 mol, of aliphatic unsaturated monovalent hydrocarbon groups such as alkenyl groups and alkynyl groups in the cyclic organopolysiloxane represented by formula (6) per 1 mol of hydrosilyl groups (SiH groups) in the organohydrogensilane or organohydrogenpolysiloxane represented by formula (5), in order to suppress by-products during the hydrosilylation addition reaction and to improve the storage stability and properties of the resulting organosilicon compound.

[0040] Furthermore, in consideration of suppressing by-products during the hydrosilylation addition reaction and improving the shelf life and properties of the resulting organosilicon compound, the reaction ratio between the organosilane or organopolysiloxane represented by formula (7) and the cyclic organohydrogenpolysiloxane represented by formula (8) is preferably such that 0.5 to 1.5 mol, and more preferably 0.7 to 1.4 mol, of aliphatic unsaturated monovalent hydrocarbon groups such as alkenyl groups and alkynyl groups in the organosilane or organopolysiloxane represented by formula (7) per 1 mol of hydrosilyl groups (SiH groups) in the cyclic organohydrogenpolysiloxane represented by formula (8).

[0041] The platinum compound-containing catalyst used in the hydrosilylation addition reaction is not particularly limited, and specific examples include chloroplatinic acid, an alcohol solution of chloroplatinic acid, a toluene or xylene solution of a platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex, tetrakistriphenylphosphine platinum, dichlorobistriphenylphosphine platinum, dichlorobisacetonitrile platinum, dichlorobisbenzonitrile platinum, dichlorocyclooctadiene platinum, supported catalysts such as platinum-carbon, platinum-alumina, and platinum-silica. Of these, a toluene or xylene solution of a platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex is preferred from the viewpoint of regioselectivity of the hydrosilylation addition reaction.

[0042] The amount of platinum compound-containing catalyst used is not particularly limited, but from the viewpoint of reactivity and productivity, it is preferable that the amount of platinum atoms contained is 1×10 per 1 mol of organosilane compound or organopolysiloxane compound having an aliphatic unsaturated monovalent hydrocarbon group such as an alkenyl group or alkynyl group represented by the above formula (6) or (7). -7 ~1 x 10 -2 The amount is preferably 1×10 -7 ~1 x 10 -3 It is more preferable that the amount is 100 mol.

[0043] A co-catalyst may be used to improve the reactivity of the hydrosilylation addition reaction. While any co-catalyst generally used in hydrosilylation addition reactions can be used, in the present invention, ammonium salts of inorganic acids, acid amide compounds, and carboxylic acids are preferred.

[0044] Specific examples of ammonium salts of inorganic acids include ammonium chloride, ammonium sulfate, ammonium amidosulfate, ammonium nitrate, monoammonium dihydrogen phosphate, diammonium hydrogen phosphate, triammonium phosphate, ammonium diphosphite, ammonium carbonate, ammonium hydrogen carbonate, ammonium sulfide, ammonium borate, ammonium fluoroborate, etc. Among these, ammonium carbonate and ammonium hydrogen carbonate are preferred.

[0045] Specific examples of the acid amide compound include formamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, propionamide, acrylamide, malonamide, succinamide, maleamide, fumaramide, benzamide, phthalamide, palmitic acid amide, and stearic acid amide. Among these, formamide and stearic acid amide are preferred, and formamide is more preferred.

[0046] Specific examples of carboxylic acids include formic acid, acetic acid, propionic acid, butyric acid, methoxyacetic acid, pentanoic acid, caproic acid, heptanoic acid, octanoic acid, lactic acid, glycolic acid, trifluoroacetic acid, maleic acid, fumaric acid, succinic acid, tartaric acid, and oxalic acid. Among these, formic acid, acetic acid, lactic acid, maleic acid, fumaric acid, succinic acid, and trifluoroacetic acid are preferred, and acetic acid and trifluoroacetic acid are more preferred.

[0047] The amount of the co-catalyst used is not particularly limited, but from the viewpoints of the reactivity and regioselectivity of the hydrosilylation addition reaction, cost, etc., it is preferred that the amount of the co-catalyst used be 1×10 per 1 mol of the organosilane compound or organopolysiloxane compound having an aliphatic unsaturated monovalent hydrocarbon group such as an alkenyl group or alkynyl group represented by the above formula (6) or (7). -5 ~1 x 10 -1 mol is preferred, and 1×10 -4 ~5 x 10-1 mol is more preferred.

[0048] The hydrosilylation addition reaction proceeds in the absence of a solvent, but can also be carried out in the presence of a solvent. Specific examples of solvents that can be used include hydrocarbon solvents such as pentane, hexane, cyclohexane, heptane, isooctane, benzene, toluene, and xylene; ether solvents such as diethyl ether, tetrahydrofuran, and dioxane; ester solvents such as ethyl acetate and butyl acetate; aprotic polar solvents such as N,N-dimethylformamide; and chlorinated hydrocarbon solvents such as dichloromethane and chloroform. These solvents can be used alone or in combination.

[0049] The amount of solvent used is not particularly limited, but from the viewpoint of productivity, such as production efficiency, it is preferably 0 to 1,000 parts by mass, and more preferably 0 to 300 parts by mass, per 100 parts by mass of the total of the organosilane compound or organopolysiloxane compound having an aliphatic unsaturated monovalent hydrocarbon group, such as an alkenyl group or alkynyl group, represented by formula (6) or (7) above, and the organosilane compound or organopolysiloxane compound having a silicon-bonded hydrogen atom, represented by formula (5) or (8) above.

[0050] The reaction temperature in the hydrosilylation addition reaction is not particularly limited, and the reaction can be carried out from room temperature (23°C ± 15°C) under heating, with room temperature (23°C ± 15°C) to 200°C being preferred. To obtain a moderate reaction rate, the reaction is more preferably carried out under heating, and when the reaction is carried out under heating, the reaction temperature is more preferably 40 to 110°C, and even more preferably 40 to 90°C. The reaction time is also not particularly limited, and is preferably 1 to 60 hours, more preferably 1 to 30 hours, and even more preferably 1 to 20 hours.

[0051] Examples of the compound represented by the above formula (1) obtained in this manner include, but are not limited to, those represented by the following formulas:

[0052] (In the formula, k is an integer of 0 to 2, m is an integer of 3 to 6, k+m is an integer of 3 to 8, and n is an integer of 0 to 100.)

[0053] Specific examples of the compound represented by the above formula (1) obtained in this manner include, but are not limited to, the following compounds:

[0054] The blending amount of component (B) is 0.01 to 50 parts by mass, and preferably 0.1 to 10 parts by mass, per 100 parts by mass of component (A). If the blending amount is less than 0.01 part by mass, the resulting composition will not cure sufficiently, whereas if the blending amount exceeds 50 parts by mass, the resulting cured product will be hard and will not be able to elongate, which is economically disadvantageous.

[0055] Component (C) is a deamidated silane represented by the following formula (2), and is used as a chain extender for room-temperature-curable organopolysiloxane compositions. (In the formula, R 4 are independently a methyl group, a vinyl group, or a phenyl group, and R 5 are independently a methyl group, an ethyl group, or a phenyl group.

[0056] Examples of such deamidated silane compounds include dimethyldi(methylacetamido)silane, divinyldi(methylacetamido)silane, diphenyldi(methylacetamido)silane, methylvinyldi(methylacetamido)silane, methylphenyldi(methylacetamido)silane, phenylvinyldi(methylacetamido)silane, dimethyldi(ethylacetamido)silane, divinyldi(ethylacetamido)silane, diphenyldi(ethylacetamido)silane, methylvinyldi(ethylacetamido)silane, methylphenyldi(ethylacetamido)silane, phenylvinyldi(ethylacetamido)silane, dimethyldi(phenylacetamido)silane, divinyldi(phenylacetamido)silane, diphenyldi(phenylacetamido)silane, methylvinyldi(phenylacetamido)silane, methylphenyldi(phenylacetamido)silane, and phenylvinyldi(phenylacetamido)silane. These compounds may be used alone or in combination of two or more.

[0057] The blending amount of component (C) is 1 to 20 parts by mass, and preferably 2 to 10 parts by mass, per 100 parts by mass of component (A). If the blending amount is less than 1 part by mass, the composition will have poor curability, while if the blending amount is more than 20 parts by mass, the composition will also have poor curability and will be economically disadvantageous.

[0058] The amount of component (C) blended is preferably an amount such that the mass ratio of component (C) to component (B) ((C) / (B)) is 0.02 to 1,000, more preferably 0.1 to 200, and particularly preferably 0.5 to 50.

[0059] Component (D) is a filler that is blended as needed and is used to impart sufficient mechanical strength to a cured product formed from this composition. Known fillers can be used as this filler, and examples thereof include one or more of the following: surface-treated or untreated (i.e., hydrophobic or hydrophilic) dry silica such as fused silica, calcined silica, fumed silica, and silica aerogel; wet silica such as precipitated silica and sol-gel silica; silica-based fine powders such as diatomaceous earth; metal oxides such as iron oxide, zinc oxide, and titanium oxide; calcium carbonates such as colloidal calcium carbonate and heavy calcium carbonate; metal carbonates such as magnesium carbonate and zinc carbonate; inorganic fillers such as asbestos, glass wool, carbon black, and finely divided mica; and synthetic resin powders such as polystyrene, polyvinyl chloride, and polypropylene.

[0060] When component (D) is blended, the blending amount is preferably 1 to 1,000 parts by mass, more preferably 1 to 400 parts by mass, and particularly preferably 5 to 200 parts by mass, per 100 parts by mass of component (A). If the amount is less than 1 part by mass, the cured product obtained from this composition tends to lack sufficient mechanical strength, while if more than 1,000 parts by mass is used, not only does the viscosity of the composition increase, making workability difficult, but the rubber strength after curing also tends to decrease, making it difficult to obtain rubber elasticity.

[0061] Component (E) is a plasticizer that is added as needed, and it can adjust the viscosity of the composition to be easy to handle during application without impairing the mechanical properties or flame retardancy of the cured product formed from this composition.

[0062] Examples of plasticizers that can be used in the room-temperature-curable organopolysiloxane composition of the present invention include dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), diheptyl phthalate (DHP), dioctyl phthalate (DOP), diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), ditridecyl phthalate (DTDP), butyl benzyl phthalate (BBP), and dicyclohexyl phthalate ( DCHP), tetrahydrophthalic acid esters, dioctyl adipate (DOA), diisononyl adipate (DINA), diisodecyl adipate (DIDA), di-n-alkyl adipates, dibutyl diglycol adipate (BXA), bis(2-ethylhexyl) azelaate (DOZ), dibutyl sebacate (DBS), dioctyl sebacate (DOS), dibutyl maleate (DBM), di-2-ethylhexyl maleate (D OM), dibutyl fumarate (DBF), tricresyl phosphate (TCP), triethyl phosphate (TEP), tributyl phosphate (TBP), tris(2-ethylhexyl)phosphate (TOP), tri(chloroethyl)phosphate (TCEP), trisdichloropropyl phosphate (CPP), tributoxyethyl phosphate (TBXP), tris(β-chloropropyl)phosphate (TMCPP), triphenyl phosphate (TPP), octyldiphenyl phosphate (ODP), acetyltriethyl citrate, acetyltributyl citrate; trimellitic acid-based plasticizers, polyester-based plasticizers, chlorinated paraffin, stearic acid-based plasticizers; silicone oils (non-functional organopolysiloxanes) such as dimethylpolysiloxane; and petroleum-based high-boiling point solvents such as polyoxypropylene glycol-based, paraffin-based, naphthenic, and isoparaffin-based solvents. These may be used alone or in combination of two or more. Among these, silicone oil is particularly preferred.

[0063] As the silicone oil (non-functional organopolysiloxane), an organopolysiloxane represented by the following general formula (9) can be preferably used. (In the formula, R 7are independently unsubstituted or substituted monovalent hydrocarbon groups having 1 to 20 carbon atoms, excluding aliphatic unsaturated bonds, and r is a number that gives the organopolysiloxane a viscosity of 1.5 to 1,000,000 mPa·s at 23°C.

[0064] In the above formula (9), R 7 are independently unsubstituted or substituted monovalent hydrocarbon groups having 1 to 20 carbon atoms excluding aliphatic unsaturated bonds, and specific examples include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, octyl, nonyl, and decyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups such as benzyl, phenylethyl, and phenylpropyl; and groups in which some or all of the hydrogen atoms have been substituted with halogen atoms such as F, Cl, or Br, such as chloromethyl, chloropropyl, bromoethyl, and trifluoropropyl.

[0065] In the above formula (9), the difunctional diorganosiloxane unit ((SiR 7 2O 2 / 2 )) is a number that gives the organopolysiloxane a viscosity of 1.5 to 1,000,000 mPa s at 23°C, and is typically an integer of 3 to 3,000, preferably an integer of 5 to 2,000, and more preferably an integer of 10 to 1,000.

[0066] The organopolysiloxane represented by formula (9) preferably has a viscosity of 1.5 to 1,000,000 mPa·s, and more preferably 10 to 100,000 mPa·s, at 23° C. If the organopolysiloxane has a viscosity of less than 1.5 mPa·s, the mechanical properties and flame retardancy of the resulting cured product may be impaired, while if it exceeds 1,000,000 mPa·s, the viscosity may become difficult to handle during application, resulting in poor workability.

[0067] When component (E) is included, the amount included is preferably 1 to 1,000 parts by mass, more preferably 2 to 500 parts by mass, and even more preferably 5 to 200 parts by mass, per 100 parts by mass of component (A). When the amount of component (E) is within the above range, the viscosity of the room-temperature-curable organopolysiloxane composition of the present invention can be adjusted to a level that is easy to handle in application, without impairing the mechanical properties or flame retardancy of the resulting cured product, which is preferred.

[0068] [Other Components] In addition to components (A) to (E), the room-temperature-curable organopolysiloxane composition of the present invention may contain known additives such as pigments, dyes, antioxidants, antistatic agents, antioxidants such as iron oxide, antimony oxide, flame retardants such as chlorinated paraffins, etc. Furthermore, polyethers as thixotropy improvers, mildew inhibitors, and antibacterial agents may also be added, provided that the purpose of the present invention is not impaired.

[0069] The room-temperature-curable organopolysiloxane composition of the present invention may contain an organic solvent, if necessary. Examples of the organic solvent include aliphatic hydrocarbon compounds such as n-hexane, n-heptane, isooctane, and isododecane; aromatic hydrocarbon compounds such as toluene and xylene; linear siloxanes such as hexamethyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, dodecamethylpentasiloxane, and 2-(trimethylsiloxy)-1,1,1,2,3,3,3-heptamethyltrisiloxane; and cyclic siloxanes such as octamethylcyclopentasiloxane and decamethylcyclopentasiloxane. The amount of the organic solvent may be adjusted as appropriate within a range that does not impair the effects of the present invention.

[0070] From the viewpoint of storage stability, it is preferred that the room-temperature-curable organopolysiloxane composition of the present invention does not contain a dehydroxylaminated silane compound.

[0071] The room-temperature-curable organopolysiloxane composition of the present invention can be prepared, for example, by uniformly mixing the above-mentioned components (A) to (C), and, if necessary, components (D) and (E), and other components, in a conventional manner. The resulting room-temperature-curable organopolysiloxane composition cures, for example, by leaving it at room temperature (23°C ± 15°C). The molding method, curing conditions, and other factors can be selected from known methods and conditions suited to the type of composition. For example, the composition can be cured by leaving it in the atmosphere at 23°C / 50% RH for several hours to several days (e.g., 6 hours to 7 days).

[0072] The room-temperature-curable organopolysiloxane composition of the present invention has good storage stability, can be cured in a short time, and after curing has physical properties such as low hardness and high elongation, and has sufficient adhesive strength.

[0073] In the present invention, "low hardness and high elongation" means that the durometer A hardness measured in accordance with JIS K-6249 is 1 to 15, and the elongation at break measured in accordance with JIS K-6249 is 1,000% or more. Furthermore, the strength of the cured product of the room-temperature-curable organopolysiloxane composition of the present invention refers to hardness, tensile strength, and tensile shear adhesive strength, and can be measured in accordance with the provisions of JIS K-6249.

[0074] The cured product of the room-temperature-curable organopolysiloxane composition of the present invention exhibits good flexibility and rubbery elasticity, and is therefore useful as a coating agent, adhesive, or sealant (for example, a construction sealant, etc.) The method for using the room-temperature-curable organopolysiloxane composition of the present invention as a coating agent, adhesive, or sealant may be any conventionally known method, and is not particularly limited.

[0075] Examples of articles having a coating layer made of a cured product of the room-temperature-curable organopolysiloxane composition of the present invention include articles made of glass, various resins, various metals, etc., but the material and shape of the substrate are not particularly limited. Specific examples of articles include building materials, vehicle materials, peripheral parts for semiconductor devices, electronic components, etc.

[0076] Furthermore, examples of articles that can be bonded and / or sealed with a cured product of the room-temperature-curable organopolysiloxane composition of the present invention include articles made of glass, various resins, various metals, etc., but the material and shape of the substrate are not particularly limited. Specific examples of articles include building materials, vehicle components, peripheral parts for semiconductor devices, electronic components, etc.

[0077] The present invention will be described in more detail below with reference to synthesis examples, examples, and comparative examples, but the present invention is not limited to the following examples. In the following examples, the molecular weight refers to the number average molecular weight in terms of polystyrene measured by GPC using toluene as the developing solvent. The properties in the examples are values ​​at 23°C. "Parts" means "parts by mass." The viscosity is a value measured at 23°C using a rotational viscometer (BM type, rotor No. 4, 12 rpm).

[0078] Synthesis of Organosilicon Compounds [Synthesis Example 1] Synthesis of Organosilicon Compound 1 Into a 500 mL separable flask equipped with a stirrer, a reflux condenser, a dropping funnel, and a thermometer, 34.4 g (0.1 mol, alkenyl group amount: 0.4 mol) of 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane and 0.15 g of a toluene solution of platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (platinum atomic weight: 6.8 × 10 -6 mol) and 50 g of toluene were placed in a flask and heated to 80°C. 119.5 g (0.4 mol, SiH group amount: 0.4 mol) of an organopolysiloxane having a silicon-bonded hydrogen atom (SiH group) at one molecular chain end and a silanol group (a hydroxyl group bonded to a silicon atom) at the other end, represented by the following formula (10), was added dropwise thereto, and the mixture was heated and stirred at 80°C for 3 hours. The reaction was terminated when gas chromatography measurement confirmed that the peak derived from the organopolysiloxane having a silicon-bonded hydrogen atom at one molecular chain end of the raw material had completely disappeared. After completion of the reaction, distillation under reduced pressure (120°C, 5 mmHg) was carried out for 2 hours, followed by filtration, yielding 151.4 g of organosilicon compound 1 (number average molecular weight: 1,571) represented by the following formula (11):

[0079] Synthesis Example 2 Synthesis of Organosilicon Compound 2 Into a 500 mL separable flask equipped with a stirrer, a reflux condenser, a dropping funnel, and a thermometer, 40.8 g (0.4 mol, alkenyl group amount: 0.4 mol) of vinyl(dimethyl)hydroxysilane represented by the following formula (12), 0.15 g of a toluene solution of platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (platinum atomic weight: 6.8×10 -6 A flask containing 24.1 g of 1,3,5,7-tetramethyl-1,3,5,7-tetrahydrogencyclotetrasiloxane (0.1 mol, SiH group amount: 0.4 mol) and 50 g of toluene was heated to 80°C. 24.1 g of 1,3,5,7-tetramethyl-1,3,5,7-tetrahydrogencyclotetrasiloxane (0.1 mol, SiH group amount: 0.4 mol) was added dropwise thereto, and the mixture was heated and stirred at 80°C for 3 hours. The reaction was terminated when gas chromatography measurement confirmed that the peaks derived from the raw material organopolysiloxane having alkenyl groups had completely disappeared. After the reaction was completed, evaporation under reduced pressure (120°C, 5 mmHg) was carried out for 2 hours, and filtration was carried out to obtain 64.3 g of organosilicon compound 2 (number average molecular weight: 651) represented by the following formula (13).

[0080] Example 1 Three parts of organosilicon compound 1 were added to 100 parts of a linear dimethylpolysiloxane having a viscosity of 20,000 mPa s and both molecular chain terminals capped with silanol groups, and the mixture was mixed under reduced pressure for 30 minutes. Next, 6 parts of dimethyldi(ethylacetamido)silane was added, and the mixture was mixed under reduced pressure for 60 minutes until uniform, thereby preparing room-temperature-curable organopolysiloxane composition 1.

[0081] Example 2: 130 parts of untreated heavy calcium carbonate and 3 parts of organosilicon compound 1 were added to 100 parts of a linear dimethylpolysiloxane having a viscosity of 20,000 mPa s and both molecular chain terminals capped with silanol groups, and the mixture was mixed at 120°C under reduced pressure for 120 minutes, followed by cooling to room temperature. Next, 6 parts of dimethyldi(ethylacetamido)silane was added, and the mixture was mixed under reduced pressure for 60 minutes until uniform, thereby preparing room-temperature-curable organopolysiloxane composition 2.

[0082] Example 3 Room-temperature-curable organopolysiloxane composition 3 was prepared in the same manner as in Example 2, except that 2 parts of organosilicon compound 2 was added instead of organosilicon compound 1.

[0083] Example 4 Room temperature curable organopolysiloxane composition 4 was prepared in the same manner as in Example 2, except that 6 parts of methylvinyldi(ethylacetamido)silane was added instead of dimethyldi(ethylacetamido)silane.

[0084] Comparative Example 1 Room-temperature-curable organopolysiloxane composition 5 was prepared in the same manner as in Example 2, except that organosilicon compound 1 was not added.

[0085] Comparative Example 2 Room-temperature-curable organopolysiloxane composition 6 was prepared in the same manner as in Example 2, except that dimethyldi(ethylacetamido)silane was not added.

[0086] Comparative Example 3 130 parts of untreated heavy calcium carbonate was added to 100 parts of a linear dimethylpolysiloxane having a viscosity of 20,000 mPa s and both molecular chain terminals capped with silanol groups, and the mixture was mixed for 120 minutes under reduced pressure at 120°C, followed by cooling to room temperature. Next, 8.5 parts of dimethyldi(ethylacetamido)silane and 2 parts of N,N',N''-[(1,3,5,7-tetramethyl-7-propylcyclotetrasiloxane-1,3,5-triyl)tris(oxy)]tris(N,N'-diethylamine) were added, and the mixture was mixed under reduced pressure for 60 minutes until uniform, thereby preparing room-temperature-curable organopolysiloxane Composition 7.

[0087] (Tests) [Sheet Properties] Immediately after preparation, each of the room-temperature-curable organopolysiloxane compositions prepared in Examples 1 to 4 and Comparative Examples 1 to 3 was molded into a 2 mm thick sheet and exposed to an atmosphere of 23°C and 50% RH. The sheet was then left to stand in the same atmosphere for 7 days, and the physical properties (hardness, elongation at break, tensile strength) of the resulting cured product were measured in accordance with JIS K-6249. Hardness was measured using a Durometer A hardness tester according to JIS K-6249. The results are shown in Table 1.

[0088] [Storage Test] Immediately after preparation, each room-temperature-curable organopolysiloxane composition prepared in Examples 1 to 4 and Comparative Examples 1 to 3 was sealed in a plastic cartridge and allowed to stand at 50°C and 50% RH for 4 weeks. Thereafter, each room-temperature-curable organopolysiloxane composition was exposed to an atmosphere of 23°C and 50% RH, and if it cured in the same manner as before standing, it was recorded as ◯, and if it did not cure, it was recorded as ×. The results are shown in Table 1.

[0089]

[0090] The results in Table 1 clearly show that the room-temperature-curable organopolysiloxane compositions of the present invention prepared in Examples 1 to 4 give cured products (silicone rubber cured products) that are low-hardness, highly elongated, elastomeric cured products (rubber elastic bodies), and that these compositions have excellent storage stability, particularly compared to the corresponding room-temperature-curable organopolysiloxane composition prepared in Comparative Example 3.

Claims

1. (A) 100 parts by mass of an organopolysiloxane in which both molecular chain terminals and / or one terminal are blocked with silanol groups, (B) 0.01 to 50 parts by mass of an organosilicon compound represented by the following formula (1), and (In the formula, R 1 are independently unsubstituted or substituted monovalent hydrocarbon groups having 1 to 12 carbon atoms excluding aliphatic unsaturated bonds, and R 2 is a hydrogen atom or an aliphatic unsaturated monovalent hydrocarbon group having 2 to 12 carbon atoms, and R 3 are independently unsubstituted or substituted monovalent hydrocarbon groups having 1 to 12 carbon atoms excluding aliphatic unsaturated bonds, A is a divalent hydrocarbon group having 2 to 8 carbon atoms, k is an integer of 0 to 2, m is an integer of 3 to 6, k+m is an integer of 3 to 8, and n is an integer of 0 to 100.) (C) a deamidated silane represented by the following formula (2): 1 to 20 parts by mass (In the formula, R 4 are independently a methyl group, a vinyl group, or a phenyl group, and R 5 and n is independently a methyl group, an ethyl group, or a phenyl group.

2. The room-temperature-curable organopolysiloxane composition according to claim 1, further comprising the following components (D) and / or (E) per 100 parts by mass of component (A): (D) filler: 1 to 1,000 parts by mass, (E) plasticizer: 1 to 1,000 parts by mass.

3. In the deamidated silane represented by the above formula (2), R 4 is a methyl group or a vinyl group, and R 5 2. The room-temperature-curable organopolysiloxane composition according to claim 1, wherein is an ethyl group.

4. The room-temperature-curable organopolysiloxane composition according to claim 1, which does not contain any dehydroxylamine type silane compound.

5. A coating agent comprising the room temperature curable organopolysiloxane composition according to any one of claims 1 to 4.

6. An adhesive comprising the room temperature curable organopolysiloxane composition according to any one of claims 1 to 4.

7. A sealant comprising the room temperature curable organopolysiloxane composition according to any one of claims 1 to 4.

8. An article having a coating layer made of a cured product of the room-temperature-curable organopolysiloxane composition according to any one of claims 1 to 4.

9. An article bonded and / or sealed with a cured product of the room temperature curable organopolysiloxane composition according to any one of claims 1 to 4.

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