Method for preventing gelation during production of room temperature curable organopolysiloxane composition

Abstract

To provide a room temperature-curable organopolysiloxane composition that does not cause sudden increase in viscosity or gelation during the production of the composition, and is easy to produce and has excellent storage property and a method for producing the same, and an article having the composition or a cured product of the composition.SOLUTION: A method for producing a room temperature-curable organopolysiloxane composition that comprises specific amounts of (A) an organopolysiloxane with a molecular chain end capped with a silanol group, (B) a hydroxylamine compound, (C) a hydrolyzable organosilane compound of a specific structure and / or a partial hydrolytic condensate thereof and (D) a curing catalyst, including the steps [i] for uniformly mixing (A), (B), and all or part of (C) to prepare a mixture including an organopolysiloxane with the silanol group in the component (A) being capped with a hydrolyzable organosilyl group in the component (C) and [ii] blending the mixture with the remainder of the component (C) and the component (D).SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to the production of a room-temperature curable organopolysiloxane composition (room-temperature curable silicone resin composition) containing, as a starting material for a main agent (base polymer), an organopolysiloxane having a silicon atom bonded to a hydroxyl group (i.e., a silanol group) at the molecular chain end as a silicon group capable of crosslinking by forming a siloxane bond (hereinafter, also referred to as a "reactive silicon group"). Prevent gelation in to a method .

Background Art

[0002] Polymers having reactive silicon groups hydrolyze and condense in the presence of moisture. These polymers having reactive silicon groups crosslink and cure in the presence of moisture and can be used as curable resin compositions. Among these polymers, those having a silicon-containing compound (particularly, organopolysiloxane) as the main chain are generally known as silicone polymers. The curable resin compositions using these are liquid at room temperature and have the characteristic of becoming a rubber elastic body by curing. Utilizing this characteristic as a room-temperature curable organopolysiloxane composition, they are widely used in coating agents, adhesives, building sealants, etc. Room-temperature curable organopolysiloxane compositions are often classified by the compounds released from the composition when in contact with moisture in the air. Representative examples include deacetic acid type, deoxime type, deamide type, dehydroxylamine type, deacetone type, and dealcohol type organopolysiloxane compositions. Among them, the dealcohol type organopolysiloxane composition that cures by releasing alcohol is particularly preferably used because it has little odor, does not corrode metals such as copper and iron, is excellent in self-adhesion (adhesion after curing to various base materials without using a primer), and is excellent in adhesion durability.

[0003] In order to obtain a de-alcohol type organopolysiloxane composition, it is necessary to use an organopolysiloxane that has been previously end-capped with an alkoxysilyl group as the base polymer, or to end-cap an organopolysiloxane having a silanol group as the terminal functional group with a silane compound having an alkoxy group during the manufacturing process using the organopolysiloxane as the starting material. In order to obtain ease of manufacture and storage stability, it is preferable to use an organopolysiloxane that has been previously end-capped with an alkoxysilyl group, but it has drawbacks such as high cost. As a method of end-capping the silanol group during the manufacturing process, it is generally known to blend a basic silane compound such as an amino group-containing silane as an end-capping catalyst. In Japanese Patent No. 5888112 and Japanese Patent No. 6252466 (Patent Documents 1 and 2), it is exemplified that a basic silane compound having a guanidine group or a phenylmethanamine group is used as an end-capping catalyst. However, since the basic silane compound used as the end-capping catalyst is special, it may be economically disadvantageous, or there may be a problem that the composition thickens rapidly and gels during manufacturing due to insufficient end-capping depending on the composition.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention has been made in view of the above circumstances, and provides a method for manufacturing a room temperature curable organopolysiloxane composition that does not cause rapid thickening or gelation during the manufacturing of the composition, is easy to manufacture, and has excellent storage stability. Prevent gelation in Method method The purpose is to provide.

Means for Solving the Problems

[0006] As a result of intensive studies to achieve the above object, the present inventors have found that an organopolysiloxane having a silanol group at its terminal is used as a starting material for the main agent (base polymer), a hydroxylamine compound is used as a terminal-blocking catalyst, and a hydrolyzable organosilane compound and / or its partial hydrolysis condensate as a crosslinking agent are uniformly mixed therewith, and through a terminal-blocking step of quantitatively terminal-blocking the silanol group at the end of the base polymer with a hydrolyzable silyl group during the production process, a room-temperature curable organopolysiloxane composition is produced, and it has been found that a room-temperature curable organopolysiloxane composition that does not cause rapid thickening or gelation during the production of the composition, is easy to produce, and has excellent storage stability can be obtained, thus leading to the completion of the present invention.

[0007] That is, the present invention provides a method for producing the following room-temperature curable organopolysiloxane composition. Prevent gelation in Method method as provided. [1] (A) Organopolysiloxane having both ends and / or one end of the molecular chain blocked with a silanol group: 100 parts by mass 、 ( C) The following general formula (1) R 1 4-a Si(ОR 2 ) a (1) (In the formula, R 1 is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, R 2 are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, and a is 3 or 4.) A hydrolyzable organosilane compound represented by and / or its partial hydrolysis condensate: 0.01 to 30 parts by mass, and (D) Containing an alkyltin(IV) ester compound A curing catalyst (however, tin(IV) chelate compound, (excluding component (B) and organodivalent tin compounds)): 0.3 ~20 parts by mass for producing a room-temperature curable organopolysiloxane composition containing in , [i]: At least (A) component parts and and part or all of (C) component and (B) hydroxylamine compound: 0.01 to 10 parts by mass are uniformly mixed to block the silanol groups at the molecular chain ends of the organopolysiloxane of (A) component with hydrolyzable organosilyl groups (-SiR 1 4-a (ОR 2 ) a-1 ) derived from the hydrolyzable organosilane compound of (C) component and / or its partial hydrolysis condensate to prepare a mixture containing an organopolysiloxane blocked with (however, (D) component is not included during step [i]), and [ii]: The step of blending the remainder of (C) component and (D) component into the mixture including characterized by A method for producing a room temperature curable organopolysiloxane composition. Prevent gelation in Method. [2] In step [i], 10 to 100% by mass of the whole (C) component is blended, and in step [ii], 0 to 90% by mass of the whole (C) component is blended. The method for producing a room temperature curable organopolysiloxane composition according to [1]. Prevent gelation in Method. [3] Furthermore, based on 100 parts by mass of (A) component, (E) filler: 1 to 1,000 parts by mass, (F) adhesion promoter (however, excluding (C) component): 0.1 to 30 parts by mass, (G) plasticizer: 1 to 1,000 parts by mass, and (H) organic divalent tin compound: 0.001 to 10 parts by mass One or more selected from are blended in step [i] and / or step [ii]. The method for producing a room temperature curable organopolysiloxane composition according to [1] or [2]. Prevent gelation in Method. [4] The method for producing a room temperature curable organopolysiloxane composition according to any one of [1] to [3], wherein (B) component is diethylhydroxylamine. Prevent gelation in Method. [5] The production of the room temperature curable organopolysiloxane composition according to any one of [1] to [4], wherein the component (A) is a diorganopolysiloxane having silanol groups blocking both ends of the molecular chain represented by the following general formula (2) and / or a diorganopolysiloxane having a silanol group blocking one end of the molecular chain represented by the following general formula (3). Prevent gelation in Method. [Chemical formula] (In formula (2), R 3 are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, A is an oxygen atom or a divalent hydrocarbon group having 1 to 8 carbon atoms, and m is an integer such that the viscosity of this diorganopolysiloxane at 23°C is 100 to 1,000,000 mPa·s.) [Chemical formula] (In formula (3), R 3 , A are the same as in formula (2), and n is an integer such that the viscosity of this diorganopolysiloxane at 23°C is 100 to 1,000,000 mPa·s.) [Advantages of the Invention]

[0008] The production method of the room temperature curable organopolysiloxane composition of the present invention uses an organopolysiloxane having a silanol group at the end as a starting material for the main agent (base polymer), a hydroxylamine compound as a terminal blocking catalyst, and is uniformly mixed with a hydrolyzable organosilane compound and / or its partial hydrolysis condensate as a crosslinking agent. By quantitatively end-blocking the silanol group at the end of the base polymer with a hydrolyzable silyl group during the production process, a room temperature curable organopolysiloxane composition with excellent storage stability can be stably and easily produced without causing rapid thickening or gelation during the production of the composition. [Embodiments for Carrying Out the Invention]

[0009] Hereinafter, the method for producing a room temperature curable organopolysiloxane composition of the present invention and the room temperature curable organopolysiloxane composition obtained thereby will be described in more detail.

[0010] The method for producing a room temperature curable organopolysiloxane composition of the present invention is (A) an organopolysiloxane having silanol groups blocking both ends and / or one end of the molecular chain, (B) a hydroxylamine compound, (C) the following general formula (1) R 1 4-a Si(ОR 2 ) a (1) (In the formula, R 1 is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, and R 2 are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, and a is 3 or 4.) a hydrolyzable organosilane compound represented by the formula and / or its partial hydrolysis condensate, and (D) a curing catalyst (excluding component (B) and organic divalent tin compounds) containing specific amounts of [i]: mixing at least component (A), component (B), and part or all of component (C) uniformly to block the silanol groups at the molecular chain ends of the organopolysiloxane of component (A) with hydrolyzable organosilyl groups (-SiR 1 4-a (ОR 2 ) a-1 ) derived from the hydrolyzable organosilane compound of component (C) and / or its partial hydrolysis condensate to prepare a mixture containing the organopolysiloxane (however, component (D) is not included during step [i]), and [ii]: a step of blending the remainder of component (C) and component (D) into the mixture characterized by including

[0011] [Room temperature curable organopolysiloxane composition] The room-temperature curable organopolysiloxane composition obtained by the production method of the present invention contains the reaction mixture of the following (I), component (D), and the remaining component (C) when not using all of component (C), and further contains components (E) to (H) as necessary. (I) (A) Organopolysiloxane blocked at both ends and / or one end of the molecular chain with silanol groups, (B) hydroxylamine compound, and (C) hydrolyzable organosilane compound represented by the above general formula (1) and / or its partial hydrolysis condensate, and the silanol group at the molecular chain end of the organopolysiloxane of component (A) is a hydrolyzable organosilyl group (-SiR 1 4-a (ОR 2 ) a-1 )-blocked organopolysiloxane-containing reaction mixture, (C) The remainder of the hydrolyzable organosilane compound represented by the above general formula (1) and / or its partial hydrolysis condensate, (D) Curing catalyst (excluding components (B) and (H)), (E) Filler, (F) Adhesion promoter (excluding component (C)), (G) Plasticizer, (H) Organic divalent tin compound.

[0012] (A) component: The (A) component used in the room-temperature curable organopolysiloxane composition according to the present invention is an organopolysiloxane blocked at both ends and / or one end of the molecular chain with silanol groups (i.e., hydroxyl groups bonded to silicon atoms) (that is, an organopolysiloxane having a basically linear polymer structure with a main chain composed of repeating units of diorganosiloxane units blocked at both ends of the molecular chain with silanol groups or blocked at one end of the molecular chain with a silanol group and the other end with a trialkylsilyl group), and is the starting material of the main agent (base polymer) of the room-temperature curable organopolysiloxane composition according to the present invention.

[0013] As the component (A), specifically, there may be mentioned a substantially linear diorganopolysiloxane having both molecular chain ends blocked with silanol groups represented by the following general formula (2) and / or a substantially linear diorganopolysiloxane having one molecular chain end blocked with a silanol group represented by the following general formula (3). [Chemical formula] (In formula (2), R 3 are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, A is an oxygen atom or a divalent hydrocarbon group having 1 to 8 carbon atoms, and m is an integer such that the viscosity of this diorganopolysiloxane at 23°C is 100 to 1,000,000 mPa·s.) [Chemical formula] (In formula (3), R 3 , A are the same as in formula (2), and n is an integer such that the viscosity of this diorganopolysiloxane at 23°C is 100 to 1,000,000 mPa·s.)

[0014] Here, in the general formulas (2) and (3), R 3The monovalent hydrocarbon groups having 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, which are independently unsubstituted or substituted and represented by include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, 2-ethylhexyl group, nonyl group, decyl group, dodecyl group, etc.; cycloalkyl groups such as cyclopentyl group, cyclohexyl group, etc.; alkenyl groups such as vinyl group, allyl group, propenyl group, isopropenyl group, butenyl group, pentenyl group, hexenyl group, etc.; aryl groups such as phenyl group, tolyl group, xylyl group, α-, β-naphthyl group, etc.; aralkyl groups such as benzyl group, 2-phenylethyl group, 3-phenylpropyl group, etc.; and groups in which some or all of the hydrogen atoms of these groups are substituted with halogen atoms such as F, Cl, Br, etc. or cyano groups, etc., for example, 3-chloropropyl group, 3,3,3-trifluoropropyl group, 2-cyanoethyl group, etc. Among these, those excluding aliphatic unsaturated hydrocarbon groups such as alkenyl groups are preferred, alkyl groups such as methyl group, ethyl group, etc. and aryl groups such as phenyl group are more preferred, and methyl group is particularly preferred.

[0015] In the general formulas (2) and (3), A is an oxygen atom or a divalent hydrocarbon group having 1 to 8 carbon atoms, preferably 2 to 4 carbon atoms. As the divalent hydrocarbon group, 2 ) p - or -(CH=CH) q -(where p represents an integer of 1 to 8, preferably an integer of 1 to 4, and q represents an integer of 1 to 4).) Alkylene groups and alkenylene groups such as these are preferred. Among these, an oxygen atom, -CH 2 CH 2 -, -CH 2 CH 2 CH 2 - and -CH=CH- are preferred.

[0016] In the general formulas (2) and (3), m and n are each an integer such that the viscosity of this organopolysiloxane at 23°C is 100 to 1,000,000 mPa·s. Usually, m and n are integers from 20 to 2,000, preferably integers from 20 to 1,600, more preferably integers from 20 to 1,000, and even more preferably integers of about 20 to 500. Here, the viscosity of the organopolysiloxane at 23°C is preferably 100 to 1,000,000 mPa·s, more preferably 300 to 500,000 mPa·s, particularly preferably 500 to 200,000 mPa·s, and especially preferably 1,000 to 100,000 mPa·s. The viscosity is a value measured by a rotational viscometer (e.g., BL type, BH type, BS type, cone plate type, etc.) (the same shall apply hereinafter). Further, the values of m and n indicating the number of repetitions (or degree of polymerization) of the disiloxane units ((R 3 ) 2 SiO 2 / 2 ) constituting the main chain in the organopolysiloxane can usually be determined as the number average degree of polymerization (or number average molecular weight) in terms of polystyrene in gel permeation chromatography (GPC) analysis using toluene or the like as the developing solvent.

[0017] Specific examples of the component (A) include, for example, the following.

Chemical formula

Chemical formula

[0018] The organopolysiloxane in which both ends and / or one end of the molecular chain of the component (A) is blocked with a silanol group can be used alone or in combination of two or more having different structures and degrees of polymerization.

[0019] Component (B): The room-temperature curable organopolysiloxane composition according to the present invention is characterized by containing a hydroxylamine compound (B) as a catalyst for an end-capping step for blocking (substituting) the molecular chain terminal silanol groups of an organopolysiloxane in which both ends and / or one end of the molecular chain of the component (A) are blocked with silanol groups with hydrolyzable organosilyl groups derived from a hydrolyzable organosilane compound of the component (C) described below and / or its partial hydrolysis condensate.

[0020] Examples of the hydroxylamine compound as the component (B) include hydroxylamine, dimethylhydroxylamine, diethylhydroxylamine, N-ethyl-N-hydroxy-2-propanamine, N-ethyl-N-hydroxy-1-propanamine, N-hydroxy-N-propyl-1-propanamine, N-hydroxy-N-methyl-2-butanamine, N-hydroxy-N-propyl-1-butanamine, N-ethyl-N-hydroxy-1-butanamine, N-hydroxy-N-methyl-1-butanamine, N-hydroxy-N,2-dimethyl-1-propanamine, N-hydroxy-N-(1-methylethyl)-2-propanamine, N-hydroxy-N-propyl-2-butanamine, N-ethyl-N-hydroxy-2-butanamine, N-hydroxy-N-(1-methylethyl)-1-butanamine, N-benzoyl-N-phenylhydroxylamine, and the like. Among these, diethylhydroxylamine, which has high safety and is easily available, is preferred.

[0021] The blending amount of the component (B) is preferably 0.01 to 10 parts by mass, particularly 0.1 to 1 part by mass, based on 100 parts by mass of the component (A). If the component (B) is too little, the end-capping reaction of the terminal silanol groups of the component (A) does not proceed efficiently, and if it is too much, problems such as deterioration of storage stability and economic disadvantage occur.

[0022] Component (C): The room-temperature curable organopolysiloxane composition according to the present invention is characterized by containing, as component (C), a hydrolyzable organosilane compound represented by the following general formula (1) and / or a partial hydrolysis condensate thereof. In the room-temperature curable organopolysiloxane composition according to the present invention, component (C) acts as a crosslinking agent (curing agent) that caps the terminals by a condensation reaction with the silanol groups in the organopolysiloxane of component (A) and forms a crosslinked structure. R 1 4-a Si(ОR 2 ) a (1) (In the formula, R 1 is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, R 2 are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, and a is 3 or 4.)

[0023] Here, in the general formula (1), R 1The monovalent hydrocarbon group having 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms, represented by the following formula may be unsubstituted or substituted, and examples thereof include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, 2-ethylhexyl group, nonyl group, decyl group, dodecyl group; cycloalkyl groups such as cyclopentyl group, cyclohexyl group; alkenyl groups such as vinyl group, allyl group, propenyl group, isopropenyl group, butenyl group, pentenyl group, hexenyl group; aryl groups such as phenyl group, tolyl group, xylyl group, α-, β-naphthyl group; aralkyl groups such as benzyl group, 2-phenylethyl group, 3-phenylpropyl group; and groups in which some or all of the hydrogen atoms of these groups are substituted with halogen atoms such as F, Cl, Br, cyano group, methoxy group, etc., for example, 3-chloropropyl group, 3,3,3-trifluoropropyl group, 2-cyanoethyl group, methoxymethyl group, etc. Among these, alkyl groups such as methyl group, ethyl group, etc., alkenyl groups such as vinyl group, etc., and methoxymethyl group in which one of the hydrogen atoms of the methyl group is substituted with a methoxy group are preferred, and methyl group, vinyl group, methoxymethyl group are particularly preferred.

[0024] In the general formula (1), R 2The unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms represented by is exemplified by alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, 2-ethylhexyl group, nonyl group, decyl group, dodecyl group; cycloalkyl groups such as cyclopentyl group, cyclohexyl group; alkenyl groups such as vinyl group, allyl group, propenyl group, isopropenyl group, butenyl group, pentenyl group, hexenyl group; aryl groups such as phenyl group, tolyl group, xylyl group, α-, β-naphthyl group; aralkyl groups such as benzyl group, 2-phenylethyl group, 3-phenylpropyl group; and groups in which some or all of the hydrogen atoms of these groups are substituted with halogen atoms such as F, Cl, Br, cyano group, methoxy group, etc., for example, 3-chloropropyl group, 3,3,3-trifluoropropyl group, 2-cyanoethyl group, methoxymethyl group, etc. Among these, alkyl groups such as methyl group and ethyl group are more preferable, and methyl group is particularly preferable.

[0025] (C) components include (organo)silane compounds having three or four hydrolyzable groups such as alkoxy groups in the molecule, and their partial hydrolysis condensates (that is, (organo)siloxane oligomers having three or more residual hydrolyzable groups in the molecule obtained by partially hydrolyzing and condensing the (organo)silane compounds), etc. Specifically, tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, methyl silicate, ethyl silicate, and their partial hydrolysis condensates, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, methyltris (methoxyethoxy) silane, vinyltris (methoxyethoxy) silane, methoxymethyltrimethoxysilane, methoxymethyltriethoxysilane, ethoxymethyltrimethoxysilane, ethoxymethyltriethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane and other organotrialkoxysilanes, and their partial hydrolysis condensates are included. Particularly, tetramethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane, methoxymethyltrimethoxysilane, and their hydrolysis condensates are preferred, but not limited thereto. These can be used alone or in combination of two or more.

[0026] The blending amount of the hydrolyzable organosilane compound and / or its partial hydrolysis condensate of component (C) is 0.01 to 30 parts by mass, preferably 0.5 to 10 parts by mass, based on 100 parts by mass of the above component (A). If the amount of component (C) is too small, sufficient rubber physical properties may not be obtained even when the composition is cured. If it is too large, rapid curability may be impaired or it may be economically disadvantageous.

[0027] Component (D): Component (D) according to the present invention is a curing catalyst (non-metal organic catalyst and / or metal-based catalyst) other than the above component (B) and the organic divalent tin compound of component (H) described later, and acts to promote the curing of the room temperature curable organopolysiloxane composition according to the present invention.

[0028] As the non-metallic organic catalyst of the curing catalyst, those known as the curing accelerator of the condensation-curing type organopolysiloxane composition can be used, and there is no particular limitation. For example, phosphazene-containing compounds such as N,N,N’,N’,N'',N''-hexamethyl-N'''-(trimethylsilylmethyl)-phosphorimidic triamide, amine compounds such as hexylamine and dodecylamine phosphate or salts thereof, quaternary ammonium salts such as benzyltriethylammonium acetate, silanes and siloxanes containing a guanidyl group such as tetramethylguanidylpropyltrimethoxysilane, tetramethylguanidylpropylmethyldimethoxysilane, and tetramethylguanidylpropyltris(trimethylsiloxy)silane are exemplified, but the non-metallic organic catalyst is not limited thereto. Further, one kind or two or more kinds of non-metallic organic catalysts may be used.

[0029] As the metal catalyst of the curing catalyst, those known as the curing accelerator of the condensation-curing type organopolysiloxane composition can be used, and there is no particular limitation. For example, alkyltin(IV) ester compounds such as dibutyltin(IV) diacetate, dibutyltin(IV) dilaurate, dibutyltin(IV) dioctoate, dioctyltin(IV) dineodecanoate, di-n-butyl-dimethoxytin(IV), titanate or titanium chelate compounds such as tetraisopropoxytitanium, tetra-n-butoxytitanium, tetrakis(2-ethylhexoxy)titanium, dipropoxybis(acetylacetonato)titanium, titanium isopropoxyoctylene glycol, titanium diisopropoxybis(ethylacetoacetate), alcoholate aluminum compounds such as aluminum isopropylate, aluminum secondary butyrate, aluminum chelate compounds such as aluminum alkylacetate·diisopropylate, aluminum bisethylacetoacetate·monoacetylacetonate, organometallic compounds such as zinc naphthenate, zinc stearate, zinc-2-ethyloctoate, iron-2-ethylhexoate, cobalt-2-ethylhexoate, manganese-2-ethylhexoate, cobalt naphthenate, neodecanoic acid bismuth(III), bismuth(III) 2-ethylhexanoate, bismuth(III) citrate, bismuth octylate, and lower fatty acid salts of alkali metals such as potassium acetate, sodium acetate, lithium oxalate are exemplified, but the metal catalyst is not limited thereto. Also, one kind or two or more kinds of the metal catalyst may be used.

[0030] The blending amount of the curing catalyst of component (D) is 0.001 to 20 parts by mass, preferably 0.01 to 10 parts by mass, based on 100 parts by mass of the above component (A). If the amount of component (C) is too small, sufficient curability cannot be obtained, and if it is too large, the curability is too fast, resulting in insufficient working time and being economically disadvantageous. Component (D) is not blended during the following step [i], but is blended during step [ii].

[0031] Component (E): (E) component is a filler (inorganic filler and / or organic resin filler), which is an optional component to be blended into the room temperature curable organopolysiloxane composition according to the present invention as required, and is used to impart sufficient mechanical strength to the cured product formed from this composition. Known fillers can be used as this filler. As the inorganic filler, for example, reinforcing silica-based fillers such as fine powder silica, fumed silica (fumed silica or dry silica), precipitated silica (wet silica), silica obtained by hydrophobically treating the surface of these silicas with an organosilicon compound, glass beads, glass balloons, transparent resin beads, silica aerogel, diatomaceous earth, iron oxide, zinc oxide, titanium oxide, fumed metal oxides and other metal oxides, quartz powder (crystalline silica), carbon black, talc, zeolites and bentonite and other reinforcing agents, asbestos, glass fiber, carbon fiber, colloidal calcium carbonate, calcium carbonate such as heavy calcium carbonate, metal carbonates such as magnesium carbonate and zinc carbonate, glass wool, fine mica powder, fused silica powder, etc. As the organic resin filler, for example, synthetic resin powders such as polystyrene, polyvinyl chloride, and polypropylene are used. Among these fillers, inorganic fillers such as silica, calcium carbonate, and zeolite are preferred, and particularly fumed silica and calcium carbonate with hydrophobically treated surfaces are preferred.

[0032] When blending the filler of component (E), the blending amount is preferably 1 to 1,000 parts by mass, particularly 5 to 400 parts by mass, based on 100 parts by mass of component (A) above. Blending it rather than not blending tends to make the cured product obtained from this composition exhibit sufficient mechanical strength. Also, when used in an amount more than 1,000 parts by mass, not only does the viscosity of the composition increase and the workability deteriorate, but also the rubber strength after curing tends to decrease and it becomes difficult to obtain rubber elasticity.

[0033] (F) component: (F) component is an adhesion promoter (excluding component (C)), which is an optional component to be compounded into the room-temperature curable organopolysiloxane composition according to the present invention, and is used to impart sufficient adhesiveness to the cured product formed from this composition. Specifically, aminosilanes such as γ-aminopropyltriethoxysilane, 3-2-(aminoethylamino)propyltrimethoxysilane [alias: N-2-(aminoethyl)-3-aminopropyltrimethoxysilane], epoxy silanes such as γ-glycidoxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, (meth)acrylic silanes such as γ-(meth)acryloxypropyltrimethoxysilane, γ-(meth)acryloxypropyltriethoxysilane, mercaptosilanes such as γ-mercaptopropyltrimethoxysilane, isocyanate silanes such as γ-isocyanatopropyltrimethoxysilane, etc., and hydrolyzable organosilane compounds having a monovalent hydrocarbon group containing a functional group having a heteroatom such as a nitrogen atom, an oxygen atom, or a sulfur atom (excluding a guanidyl group) other than a hydrolyzable group (so-called carbon-functional silane or silane coupling agent), etc. are preferably compounded. Note that the adhesion promoter of component (F) (carbon-functional silane or silane coupling agent) is clearly distinguished from the hydrolyzable organosilane compound and / or its partial hydrolysis condensate of component (C) in that it has a monovalent hydrocarbon group containing a functional group having a heteroatom such as a nitrogen atom, an oxygen atom, or a sulfur atom (excluding a guanidyl group) other than a hydrolyzable group (however, it does not contain an organooxy-substituted alkyl group such as a methoxymethyl group) in the molecule.

[0034] When the adhesion promoter of component (F) is compounded, its compounding amount is preferably 0.1 to 30 parts by mass, particularly 0.5 to 20 parts by mass, based on 100 parts by mass of the above component (A). If it exceeds 30 parts by mass, the curability may become insufficient or it may be economically disadvantageous. Component (F) is preferably not compounded during step [i] described below, and is compounded during step [ii] as necessary.

[0035] (G) component: (G) The component is a plasticizer and is an optional component that is blended into the room-temperature curable organopolysiloxane composition according to the present invention. Without impairing the mechanical properties and flame retardancy of the cured product formed from this composition, it can be adjusted to a viscosity that is easy to handle in construction.

[0036] Examples of the plasticizer used in the room-temperature curable organopolysiloxane composition according to 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), dicyclohexyl phthalate (DCHP), tetrahydrophthalic acid ester, dioctyl adipate (DOA), diisononyl adipate (DINA), diisodecyl adipate (DIDA), di-n-alkyl adipate, dibutyl diglycol adipate (BXA), bis(2-ethylhexyl) azelate (DOZ), dibutyl sebacate (DBS), dioctyl sebacate (DOS), dibutyl maleate (DBM), di-2-ethylhexyl maleate (DOM), dibutyl fumarate (DBF), tricresyl phosphate (TCP), triethyl phosphate (TEP), tributyl phosphate (TBP), tris(2-ethylhexyl) phosphate (TOP), tris(chloroethyl) phosphate (TCEP), tris(dichloropropyl) phosphate (CPP), tributoxyethyl phosphate (TBXP), tris(β-chloropropyl) phosphate (TMCPP), triphenyl phosphate (TPP), octyldiphenyl phosphate (ODP), acetyltriethyl citrate, tributyl acetyl citrate, etc. In addition, there are trimellitic acid-based plasticizers, polyester-based plasticizers, chlorinated paraffins, stearic acid-based plasticizers, etc. Furthermore, silicone oils (non-functional organopolysiloxanes) such as dimethylpolysiloxane whose both ends of the molecular chain are blocked with trimethylsilyl groups, and recently, petroleum-based high-boiling solvents such as polyoxypropylene glycol-based, paraffin-based, naphthene-based, and isoparaffin-based solvents can be mentioned. These are used alone or in combination of two or more. Among them, silicone oil (non-functional organopolysiloxane) is particularly preferred.

[0037] In addition, as the above silicone oil (non-functional organopolysiloxane), preferably, an organopolysiloxane represented by the following general formula (4) can be used.

[0038]

Chemical formula

[0039] In the general formula (4), R 4 are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms that does not contain an unsubstituted or substituted aliphatic unsaturated bond. Specifically, alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group, cyclohexyl group, octyl group, nonyl group, decyl group, etc., aryl groups such as phenyl group, tolyl group, xylyl group, naphthyl group, etc., aralkyl groups such as benzyl group, phenylethyl group, phenylpropyl group, etc., and those in which some or all of the hydrogen atoms of these groups are substituted with halogen atoms such as F, Cl, Br, etc., for example, chloromethyl group, chloropropyl group, bromoethyl group, trifluoropropyl group, etc. can be mentioned.

[0040] In addition, in the organopolysiloxane represented by the above formula (4), the value of b indicating the number of repetitions (degree of polymerization) of the diorganosiloxane unit is usually an integer of about 3 to 3,000, preferably 5 to 2,000, more preferably 10 to 1,000. Here, the viscosity of the organopolysiloxane at 23 °C is preferably 1.5 to 1,000,000 mPa·s, more preferably 10 to 100,000 mPa·s.

[0041] When blending the (G) component, the blending amount is preferably 1 to 1,000 parts by mass, more preferably 2 to 500 parts by mass, and still more preferably 3 to 200 parts by mass with respect to 100 parts by mass of the above (A) component. When the amount of the (F) component is within the above range, it is preferable because the mechanical properties and flame retardancy of the room temperature curable organopolysiloxane composition according to the present invention can be adjusted to a viscosity that is easy to handle in construction without impairing them.

[0042] (H) component: (H) component is an organic divalent tin compound, which is an optional component blended in the room temperature curable organopolysiloxane composition according to the present invention as needed, and is used to improve the end-capping efficiency as an auxiliary catalyst in the end-capping step using a (B) hydroxylamine compound as a catalyst. Therefore, when blending the (H) component, it is preferably blended in step [i].

[0043] As the organic divalent tin compound used in the room temperature curable organopolysiloxane composition according to the present invention, a divalent tin salt of a carboxylic acid (a salt of a carboxylic acid and divalent tin (II)) is preferable, and examples thereof include divalent tin (II) compounds such as tin (II) 2-ethylhexanoate [also known as: tin (II) octoate], tin (II) octanoate, and tin (II) neodecanoate. Among these, easily available tin (II) 2-ethylhexanoate is preferable.

[0044] When blending the (H) component, the blending amount is preferably 0.001 to 10 parts by mass, particularly preferably 0.01 to 1 part by mass with respect to 100 parts by mass of the above (A) component. When the amount of the (H) component is within the above range, it is preferable because the end-capping reaction of the room temperature curable organopolysiloxane composition according to the present invention can proceed efficiently. If it exceeds 10 parts by mass, it may be disadvantageous in production, such as gel generation during the end-capping step, or may be economically disadvantageous.

[0045] [Other components] In addition, a thixotropic agent can be blended as an optional additive in the room temperature curable organopolysiloxane composition according to the present invention within a range that does not impair the object of the present invention. Examples of the thixotropy-imparting agent include polyether compounds typified by polyethylene oxide (polyoxyethylene), polypropylene oxide (polyoxypropylene), ethylene oxide-propylene oxide copolymer (polyoxyethylene-polyoxypropylene copolymer), and polymers in which the molecular chain terminals (one terminal or both terminals) thereof are blocked with an alkyl ether, compounds obtained by subjecting the polyether compounds to silane modification or silicone modification, polyether phosphate esters, polyether fatty acid esters, fatty acid amide waxes, hydrogenated castor oil, oxidized polyolefins, and the like.

[0046] In addition, in the room-temperature curable organopolysiloxane composition according to the present invention, as optional additives, glycerin esters of fatty acids having fatty acid ester groups such as triacetin, diacetin, monoacetin, tributyrin, tricaprylin, tristearin, glycerol diacetate laurate, trimethylolpropane tristearate, trimethylolpropane triacetate, pentaerythritol monoacetate, and the like, fatty acid ester compounds of polyhydric alcohols having three or more fatty acid ester groups or a total of three or more fatty acid ester groups and hydroxyl groups in the molecule can be blended as storage stabilizers (preservation improvers). In addition, known additives such as pigments, dyes, anti-aging agents, antioxidants, antistatic agents, flame retardants such as antimony oxide and chlorinated paraffin can be blended within a range not impairing the object of the present invention. Furthermore, fungicides and antibacterial agents can also be blended.

[0047] Furthermore, the room-temperature curable organopolysiloxane composition according to the present invention may use an organic solvent as needed. 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; chain 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 appropriately adjusted within a range that does not interfere with the effects of the present invention.

[0048] [Method for producing room-temperature curable organopolysiloxane composition] In the method for producing the room-temperature curable organopolysiloxane composition of the present invention, in each of the above-described components, at least all of the (A) component, all of the (B) component, and part or all of the (C) component, excluding the (D) component, are uniformly mixed, and the silanol groups at the molecular chain terminals of the organopolysiloxane of the (A) component are converted into hydrolyzable organosilyl groups (-SiR 1 4-a (ОR 2 ) a-1 )-blocked organopolysiloxane (main agent (base polymer)) to prepare a reaction mixture (I) (terminal blocking step) (step [i]), and a step of adding the remainder of the (C) component and all of the (D) component to the reaction mixture (I) (step [ii]).

[0049] In the method for producing a room-temperature curable organopolysiloxane composition of the present invention, the hydrolyzable organosilane compound and / or its partial hydrolysis condensate as component (C) is, with respect to the above steps [i] and [ii], 10 to 100% by mass, particularly 30 to 100% by mass, and more preferably 50 to 100% by mass of the whole component (C) is blended in step [i], and 0 to 90% by mass, particularly 0 to 70% by mass, and more preferably 0 to 50% by mass of the whole component (C) is blended in step [ii]. If the blending ratio in step [i] is too small, the end-capping reaction does not proceed sufficiently, and when component (D) or component (F) is added after the end-capping step, gelation or thickening occurs, which is disadvantageous in production.

[0050] In step [i], the mixing of each component may be carried out under substantially anhydrous conditions, at normal pressure or reduced pressure, under any temperature conditions (usually 0 to 100 °C, preferably 10 to 70 °C), and the time is usually 5 minutes to 5 hours, preferably about 10 minutes to 2 hours.

[0051] By step [i], a reaction mixture (I) containing an organopolysiloxane in which the silanol groups at the molecular chain ends of the organopolysiloxane as component (A) are blocked with hydrolyzable organosilyl groups (-SiR 1 4-a (ОR 2 ) a-1 ) derived from the hydrolyzable organosilane compound and / or its partial hydrolysis condensate of component (C) is obtained.

[0052] After the end-capping step (step [i]), the remainder of component (C) and all of component (D) are blended (step [ii]). Here, the (E) component, (F) component, (G) component, (H) component, and other components may be mixed in Step [ii], or may be mixed simultaneously during the terminal blocking step (Step [i]). However, when the (F) component is an aminosilane, if it is blended during the terminal blocking step (Step [i]), the properties of the mixture may become saggy, which may be disadvantageous especially when used as an adhesive or a building sealant. Therefore, it is preferably added after the terminal blocking step (in Step [ii]). Further, since the (H) component is used to improve the terminal blocking efficiency as an auxiliary catalyst for the terminal blocking step using the (B) hydroxylamine compound as a catalyst, it is preferably added in Step [i].

[0053] In Step [ii], the mixing of each component may be carried out under substantially anhydrous conditions, at normal pressure or reduced pressure, under any temperature conditions (usually 0 to 100°C, preferably 10 to 70°C), and the time is usually 5 minutes to 5 hours, preferably about 10 minutes to 2 hours.

[0054] In the terminal blocking step, when the terminal blocking of the (A) component is insufficient, gel may be generated or the viscosity may increase when the (D) component or (F) component is added after the terminal blocking step, or the storage stability of the obtained composition may deteriorate even if gel is not generated. However, the room temperature curable organopolysiloxane composition produced under the above-mentioned conditions has a well-progressed terminal blocking step, starting from an organopolysiloxane having an inexpensive terminal functional group as a silanol group, and can be produced under mild conditions and in a very short time. Therefore, the productivity is improved, and the storage stability is also good, which is economically advantageous.

[0055] The room temperature curable organopolysiloxane composition obtained by the production method of the present invention cures by being left at room temperature (23°C ± 15°C). For its molding method, curing conditions, etc., known methods and conditions according to the type of the composition can be adopted. In particular, the one-component type composition is stored in the absence of moisture, that is, in a sealed container blocking moisture, and cured easily at room temperature (23°C ± 15°C) by being exposed to the moisture in the air during use.

[0056] In addition, the obtained cured product shows good flexibility and has rubber elasticity, so it is useful as a coating agent, an adhesive, a sealing material (for example, a building sealant, etc.). The method of using the room temperature curable organopolysiloxane composition obtained by the production method of the present invention as a coating agent, an adhesive, a sealing material may follow the conventionally known use methods and is not particularly limited.

[0057] Examples of the article having a coating layer composed of the cured product of the room temperature curable organopolysiloxane composition obtained by the production method of the present invention include articles made of glasses, various resins, various metals, etc., but the material and shape of the substrate are not particularly limited.

[0058] Examples of the article adhered and / or sealed with the cured product of the room temperature curable organopolysiloxane composition obtained by the production method of the present invention include articles made of glasses, various metals, etc., but the material and shape of the substrate are not particularly limited.

Examples

[0059] Hereinafter, examples , reference examples, comparative examples and reference comparative examples are shown to specifically explain the present invention, but the present invention is not limited to the following examples. In the following specific examples, "parts" means "parts by mass", and the viscosity is the measured value by a rotational viscometer at 23°C. Also, the preparation of the composition was carried out at an indoor temperature of 23°C.

[0060] [Example 1] 100 parts of a linear dimethylpolysiloxane with a viscosity of 50,000 mPa·s and both ends of the molecular chain blocked with silanol groups, 10 parts of vinyltrimethoxysilane, and 0.4 part of diethylhydroxylamine were added and mixed for 30 minutes to perform an end-capping step of blocking the silanol groups at both ends of the molecular chain of the linear dimethylpolysiloxane with vinyldimethoxysilyl groups. Next, 40 parts of a linear dimethylpolysiloxane with a viscosity of 100 mPa·s and both ends of the molecular chain blocked with trimethylsilyl groups and 15 parts of fumed silica were added to the mixture, and the mixture was mixed under reduced pressure for 30 minutes. Then, 0.8 part of N-2-(aminoethyl)-3-aminopropyltrimethoxysilane and 0.3 part of dioctyltin(IV) dineodecanoate (Neostan U-830, manufactured by Nitto Kasei Co., Ltd.) were added to the mixture, and the mixture was mixed under reduced pressure for 15 minutes until it became homogeneous to prepare Composition 1.

[0061] [Example 2] 100 parts of a linear dimethylpolysiloxane with a viscosity of 50,000 mPa·s and both ends of the molecular chain blocked with silanol groups, 40 parts of a linear dimethylpolysiloxane with a viscosity of 100 mPa·s and both ends of the molecular chain blocked with trimethylsilyl groups, 15 parts of fumed silica, and 0.5 part of a polyoxyethylene·polyoxypropylene copolymer monobutyl ether (Unilube C, manufactured by NOF Corporation) were mixed under reduced pressure for 30 minutes. Next, 10 parts of vinyltrimethoxysilane and 0.4 part of diethylhydroxylamine were added to the mixture, and the mixture was mixed under reduced pressure for 30 minutes to perform an end-capping step of blocking the silanol groups at both ends of the molecular chain of the linear dimethylpolysiloxane with vinyldimethoxysilyl groups. After mixing under reduced pressure, 0.8 part of N-2-(aminoethyl)-3-aminopropyltrimethoxysilane and 0.3 part of dioctyltin(IV) dineodecanoate (Neostan U-830, manufactured by Nitto Kasei Co., Ltd.) were added to the mixture, and the mixture was mixed under reduced pressure for 15 minutes until it became homogeneous to prepare Composition 2.

[0062] [Example 3] In Example 2, Composition 3 was prepared in the same manner as in Example 2, except that 10 parts of methyltrimethoxysilane and 0.05 part of tin(II) 2-ethylhexanoate were used instead of 10 parts of vinyltrimethoxysilane during the terminal capping step.

[0063] [Example 4] In Example 2, instead of 100 parts of linear dimethylpolysiloxane with silanol groups blocking both ends of the molecular chain having a viscosity of 50,000 mPa·s and 40 parts of linear dimethylpolysiloxane with trimethylsilyl groups blocking both ends of the molecular chain having a viscosity of 100 mPa·s, 85 parts of linear dimethylpolysiloxane with silanol groups blocking both ends of the molecular chain having a viscosity of 20,000 mPa·s, 50 parts of linear dimethylpolysiloxane with a silanol group at one end of the molecular chain and a trimethylsilyl group at the other end of the molecular chain having a viscosity of 20,000 mPa·s, and 5 parts of dimethylpolysiloxane with trimethylsilyl groups blocking both ends having a viscosity of 20,000 mPa·s were used. A terminal capping step was performed to block the silanol groups at both ends of the molecular chain and the silanol group at one end of the molecular chain of the linear dimethylpolysiloxane with vinyl dimethoxysilyl groups, respectively. Composition 4 was prepared in the same manner as in Example 2, except for this.

[0064] reference example ​​100 parts of linear dimethylpolysiloxane with silanol groups blocking both ends of the molecular chain and a viscosity of 20,000 mPa·s, 40 parts of linear dimethylpolysiloxane with trimethylsilyl groups blocking both ends of the molecular chain and a viscosity of 100 mPa·s, 5 parts of vinyltrimethoxysilane, and 0.5 part of diethylhydroxylamine were mixed uniformly for 30 minutes under moisture shielding to perform an end-capping process of blocking the silanol groups at both ends of the molecular chain of the linear dimethylpolysiloxane with vinyldimethoxysilyl groups. Next, 100 parts of colloidal calcium carbonate and 100 parts of heavy calcium carbonate were added to the mixture and mixed under reduced pressure for 30 minutes. After mixing under reduced pressure, 5 parts of methyltrimethoxysilane, 0.5 part of γ-aminopropyltriethoxysilane, 1 part of triacetin, and 5 parts of titanium diisopropoxybis(ethylacetoacetate) (Organix TC-750, manufactured by Matsumoto Fine Chemical Co., Ltd.) were added to the mixture and mixed under reduced pressure until uniform for 15 minutes to prepare Composition 5.

[0065] [Comparative Example 1] In Example 2, Composition 6 was prepared in the same manner as in Example 2 except that 0.4 part of diethylhydroxylamine was not added. However, the system gelled after adding aminosilane (N-2-(aminoethyl)-3-aminopropyltrimethoxysilane) and tin catalyst (dioctyltin(IV) dineodecanoate) in Step [ii], and Composition 6 could not be prepared.

[0066] [Comparative Example 2] In Example 2, Composition 7 was prepared in the same manner as in Example 2 except that 1 part of the basic silane compound represented by the following structural formula (5) was used instead of 0.4 part of diethylhydroxylamine. However, the system gelled after adding aminosilane (N-2-(aminoethyl)-3-aminopropyltrimethoxysilane) and tin catalyst (dioctyltin(IV) dineodecanoate) in Step [ii], and the composition could not be prepared. [Chemical formula]

[0067] reference Comparison example] reference example In this case, Composition 8 was prepared in the same manner except that 0.4 part of diethylhydroxylamine was not added. reference example And Composition 8 was prepared in the same manner.

[0068] 〔Evaluation Test〕 Examples 1 to 4, reference example And reference Comparison example The tack-free time of each composition immediately after preparation was measured. Also, Examples 1 to 4, reference example And reference Comparison example Each composition immediately after preparation was molded into a sheet with a thickness of 2 mm, exposed to air at 23°C and 50% RH, and then the physical properties (initial physical properties: hardness, elongation at break, tensile strength) of the cured product obtained by leaving the sheet in the same atmosphere for 7 days were measured in accordance with JIS K-6249. The hardness was measured using a durometer A hardness tester of JIS K-6249.

[0069] [Storage Stability] The compositions prepared in Examples 1 to 4, reference example And reference Comparison example were put into a polyethylene sealing material cartridge (capacity 330 mL), sealed with an inner plug. After storing this cartridge in a dryer at 70°C for 7 days, it was taken out, the tack-free time was measured in the same manner as above, and if it was within 2 times the tack-free time of each composition immediately after preparation, it was judged as ○ (qualified), and if it took a longer time than 2 times, it was judged as × (unqualified). The above results are shown in Table 1.

[0070]

Table 1

[0071] From the results in Table 1, Examples 1 to 4, reference example are Comparative Example 1​, 2, reference comparative example It was revealed that the composition was easier to prepare and had better storage stability as compared with

[0072] Note that the present invention is not limited to the above-described embodiments. The above-described embodiments are examples, and any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits the same operational effects is included in the technical scope of the present invention.

Claims

1. (A) Organopolysiloxane with both ends and / or one end of the molecular chain blocked by silanol groups: 100 parts by mass, (C) Hydrolyzable organosilane compound represented by the following general formula (1) R 1 4-a Si(OR 2 ) a (1) (In the formula, R 1 is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, and R 2 are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, and a is 3 or 4.) and / or its partial hydrolysis condensate: 0.01 to 30 parts by mass, and (D) A curing catalyst containing an alkyltin(IV) ester compound (excluding tin(IV) chelate compounds, component (B), and organic divalent tin compounds): 0.3 to 20 parts by mass In the production of a room-temperature curable organopolysiloxane composition containing [i]: A mixture is prepared by uniformly mixing at least the (A) component and part or all of the (C) component with 0.01 to 10 parts by mass of the (B) hydroxylamine compound to block the silanol groups at the molecular chain ends of the organopolysiloxane of the (A) component with hydrolyzable organosilyl groups (—SiR 1 4-a (OR 2 ) a-1 ) derived from the hydrolyzable organosilane compound of the (C) component and / or its partial hydrolysis condensate (however, the (D) component is not included during step [i]). and [ii]: A step of blending the remaining portion of component (C) and component (D) into the mixture A method for preventing gelation during the production of a room-temperature curable organopolysiloxane composition, characterized by including the above.

2. The method for preventing gelation during the production of a room-temperature curable organopolysiloxane composition according to Claim 1, wherein 10 to 100% by mass of the whole of component (C) is blended in step [i], and 0 to 90% by mass of the whole of component (C) is blended in step [ii].

3. Furthermore, based on 100 parts by mass of component (A), (E) Filler: 1 to 1,000 parts by mass, (F) Adhesion promoter (excluding component (C)): 0.1 to 30 parts by mass, (G) Plasticizer: 1 to 1,000 parts by mass, and (H) Organic divalent tin compound: 0.001 to 10 parts by mass The method for preventing gelation during the production of a room-temperature curable organopolysiloxane composition according to Claim 1 or 2, wherein one or more selected from the above are blended in step [i] and / or step [ii].

4. The method for preventing gelation during the production of a room-temperature curable organopolysiloxane composition according to any one of Claims 1 to 3, wherein component (B) is diethylhydroxylamine.

5. The method for preventing gelation during the production of a room-temperature curable organopolysiloxane composition according to any one of Claims 1 to 4, wherein the above component (A) is a diorganopolysiloxane with both ends of the molecular chain blocked by silanol groups represented by the following general formula (2) and / or a diorganopolysiloxane with one end of the molecular chain blocked by silanol groups represented by the following general formula (3). 【Chemical 1】 (In formula (2), R 3 is, independently of one another, an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, A is an oxygen atom or a divalent hydrocarbon group having 1 to 8 carbon atoms, and m is an integer such that the viscosity of this diorganopolysiloxane at 23°C is 100 to 1,000,000 mPa·s.) 【Chemical 2】 (In formula (3), R 3 , A is the same as in formula (2), and n is an integer such that the viscosity of this organopolysiloxane at 23°C is 100 to 1,000,000 mPa·s.)

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