Method for producing non-sag room temperature curable organopolysiloxane composition

Abstract

To easily produce a room-temperature curable organopolysiloxane composition having non-sagging properties and excellent storage stability, through capping an end in a production process, using a terminal silanol group-containing organopolysiloxane as a starting material and a specific organic divalent tin compound as a catalyst.SOLUTION: A production method is for a non-sagging room-temperature curable organopolysiloxane composition containing: (A) molecular chain silanol end-capped organopolysiloxane; (B) an organic divalent tin compound; (C) a hydrolyzable organosilane compound of a specific structure and / or a partial hydrolysis condensate thereof; (D) a specific amount of curing catalyst; and optionally (F) an adhesion promoter, and includes the steps of: [i] mixing all of the (A) and the (B) with part or all of the (C) and capping a terminal silanol group of the (A) by a hydrolyzable organosilyl group derived from the (C) to prepare a mixture containing organopolysiloxane (not including the (D) or the (F)); and [ii] blending a remainder of the (C) and all the (D) and the (F) to the mixture.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing a room-temperature-curable organopolysiloxane composition (room-temperature-curable silicone resin composition) that exhibits non-sagging properties and contains, as a base polymer, an organopolysiloxane having, at its molecular chain end, a silicon atom bonded to a hydroxyl group (i.e., a silanol group) as a silicon group capable of crosslinking by forming a siloxane bond (hereinafter also referred to as a "reactive silicon group") (i.e., a polymer having, as its main chain, an organopolysiloxane structure composed of repeating diorganosiloxane units whose molecular chain end is blocked with a silanol group). do. [Background technology]

[0002] Polymers containing reactive silicon groups undergo hydrolysis and condensation in the presence of moisture. These polymers crosslink and cure in the presence of moisture, allowing them to be used as curable resin compositions. Among these polymers, those whose main chains are silicon-containing compounds (particularly organopolysiloxanes) are generally known as silicone polymers. Curable resin compositions using these polymers are liquid at room temperature and characteristically become rubbery elastic bodies upon curing. Taking advantage of this characteristic, they are widely used as room-temperature-curable organopolysiloxane compositions in coatings, adhesives, construction sealants, and the like. Room-temperature-curable organopolysiloxane compositions are often classified by the compounds released from the composition upon contact with moisture in the air. Representative examples include deacetic acid-, deoxime-, deamido-, dehydroxylamine-, deacetone-, and dealcohol-type organopolysiloxane compositions. Among these, dealcohol-reducing organopolysiloxane compositions, which cure by releasing alcohol, are particularly preferred for their low odor, non-corrosion to metals such as copper and iron, excellent self-adhesion (adhesion to various substrates after curing when no primer is used), and excellent adhesive durability.

[0003] To obtain a dealcohol-removing organopolysiloxane composition, it is necessary to use an organopolysiloxane that has been end-blocked with alkoxysilyl groups as the base polymer, or to use an organopolysiloxane whose terminal functional groups are silanol groups as the starting material and end-block it with a silane compound having an alkoxy group during the manufacturing process. While using an organopolysiloxane that has been end-blocked with alkoxysilyl groups is preferable for ease of manufacturing and storage stability, this method has drawbacks such as increased cost. A commonly known method for end-blocking silanol groups during the manufacturing process involves incorporating a basic silane compound, such as an amino-containing silane, as an end-blocking catalyst. Patent Publications No. 5888112 and No. 6252466 (Patent Documents 1 and 2) exemplify the use of a basic silane compound having a guanidine group or a phenylmethanamine group as the end-blocking catalyst. However, the special nature of the basic silane compound used as the end-blocking catalyst can lead to economical problems. Furthermore, when a basic silane compound is used as an end-capping catalyst, the composition tends to sag, which can be disadvantageous particularly when used as an adhesive or construction sealant. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5888112 [Patent Document 2] Patent No. 6252466 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in view of the above circumstances, and provides a method for producing a room-temperature-curable organopolysiloxane composition that is easy to produce, has excellent storage stability, and exhibits non-sagging properties. The law The purpose is to provide. [Means for solving the problem]

[0006] As a result of extensive research conducted by the present inventors to achieve the above object, they have found that an end-capping step using an organic divalent tin compound is useful for solving the above-mentioned problems. That is, (A) an organopolysiloxane in which both ends and / or one end of the molecular chain are blocked with silanol groups, (B) an organic divalent tin compound, (C) a 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 halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and R 2 are each independently an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and a is 3 or 4. and / or a partial hydrolysis condensate thereof, and (D) a specific amount of a curing catalyst (excluding component (B)), and optionally further containing (F) an adhesion promoter (excluding component (C)), [i]: A process in which component (A), component (B), and part or all of component (C) are uniformly mixed, and the silanol groups at the molecular chain terminals of the organopolysiloxane of component (A) are converted to hydrolyzable organosilyl groups (-SiR 1 4-a (OR 2 ) a-1 (i) preparing a mixture containing an organopolysiloxane blocked with (D) or (F) (provided that the components (D) and (F) are not included in step [i]); [ii]: A step of blending the remainder of the component (C), the component (D), and optionally the component (F) with the mixture. The present inventors have found that a method for producing a room-temperature-curable organopolysiloxane composition comprising the above compound can easily produce a room-temperature-curable organopolysiloxane composition that is non-sagging and has excellent storage stability, and have completed the present invention.

[0007] That is, the present invention provides the following method for producing a non-sag, room-temperature-curable organopolysiloxane composition: The law It is what we provide. [1] (A) organopolysiloxane having both molecular chain ends and / or one molecular chain end blocked with silanol groups: 100 parts by mass, (B) Organic divalent tin compound: 0.001 to 10 parts by mass, (C) the following general formula (1) R 1 4-a Si(OR 2 ) a (1) (In the formula, R 1 is an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and R 2 are each independently an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and a is 3 or 4. and / or a partial hydrolysis condensate thereof: 0.01 to 30 parts by mass, (D) curing catalyst (excluding component (B)): 0.001 to 20 parts by mass, (E) filler: 1 to 1,000 parts by mass, and (F) Adhesion promoter (excluding component (C)): 0 to 30 parts by mass A method for producing a room-temperature-curable organopolysiloxane composition having non-sagging properties, comprising: [i]: Component (A) and (E) component are premixed, and then this Component (B) and part or all of component (C) are added to the mixture, and the mixture is mixed uniformly to convert the silanol groups at the molecular chain terminals of the organopolysiloxane of component (A) into hydrolyzable organosilyl groups (-SiR 1 4-a (OR 2 ) a-1 (i) preparing a mixture containing an organopolysiloxane blocked with (D) or (F) (provided that the components (D) and (F) are not included in step [i]); [ii]: A step of blending the remainder of the component (C), the component (D), and optionally the component (F) with the mixture. A method for producing a non-sag, room-temperature-curable organopolysiloxane composition comprising: [2] The method for producing a non-sag, room-temperature-curable organopolysiloxane composition according to [1], wherein 10 to 100 mass % of the total component (C) is blended in step [i], and 0 to 90 mass % of the total component (C) is blended in step [ii]. [3] Furthermore, for 100 parts by mass of component (A), 、 ( G) plasticizer: 1 to 1,000 parts by mass, and (H) Anti-sag agent: 0.01 to 10 parts by mass The method for producing a non-sag, room-temperature-curable organopolysiloxane composition according to [1] or [2], wherein one or more selected from the following are blended in step [i] and / or step [ii]. [4] The method for producing a non-sagging, room-temperature-curable organopolysiloxane composition according to any one of [1] to [3], wherein component (B) is tin(II) 2-ethylhexanoate. [5] The method for producing a non-sag, room-temperature-curable organopolysiloxane composition according to any one of [1] to [4], wherein the component (A) is a diorganopolysiloxane represented by the following general formula (2) in which both molecular chain terminals are blocked with silanol groups and / or a diorganopolysiloxane represented by the following general formula (3) in which one molecular chain terminal is blocked with a silanol group: [ka] (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 that gives the diorganopolysiloxane a viscosity of 100 to 1,000,000 mPa s at 23°C. [ka] (In formula (3), R 3 A is the same as in formula (2), and n is an integer that gives the diorganopolysiloxane a viscosity of 100 to 1,000,000 mPa·s at 23°C. [6] R in general formula (1) 2

[0023] The method for producing a non-sagging, room-temperature-curable organopolysiloxane composition according to any one of [1] to [5], wherein 。 [Effects of the Invention]

[0008] The method of producing a room-temperature-curable organopolysiloxane composition of the present invention that exhibits non-sagging properties uses an organopolysiloxane having silanol groups at its terminals as a starting material and caps the terminals during the production process using a specific organic divalent tin compound as a catalyst, thereby easily producing a room-temperature-curable organopolysiloxane composition that exhibits non-sagging properties and excellent storage stability. DETAILED DESCRIPTION OF THE INVENTION

[0009] The method for producing the non-sag, room-temperature-curable organopolysiloxane composition of the present invention and the non-sag, room-temperature-curable organopolysiloxane composition will be described in more detail below.

[0010] The method for producing the non-sag room-temperature-curable organopolysiloxane composition of the present invention includes the steps of: (A) an organopolysiloxane in which both molecular chain ends and / or one molecular chain end are blocked with silanol groups; (B) organic divalent tin compound, (C) the following general formula (1) R 1 4-a Si(OR 2 ) a (1) (In the formula, R 1 is an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and R 2 are each independently an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and a is 3 or 4. A hydrolyzable organosilane compound represented by the formula: and / or a partial hydrolysis condensate thereof, (D) Curing catalyst (excluding component (B)) A specific amount of, and if necessary (F) Adhesion promoter (excluding component (C)) Contains [i]: A method for homogeneously mixing component (A), component (B), and part or all of component (C), and converting the silanol groups at the molecular chain terminals of the organopolysiloxane of component (A) into hydrolyzable organosilyl groups (-SiR 1 4-a (OR 2 ) a-1 (i) preparing a mixture containing an organopolysiloxane blocked with (D) or (F) (provided that the components (D) and (F) are not included in step [i]); [ii]: A step of blending the remainder of the component (C), the component (D), and optionally the component (F) with the mixture. The present invention is characterized in that it comprises:

[0011] [Non-sagging room temperature curable organopolysiloxane composition] The non-sag, room-temperature-curable organopolysiloxane composition obtainable by the production method of the present invention contains the following reaction mixture (I), component (D), and, if component (C) is not used in its entirety in component (I), the remaining component (C), and, optionally, components (E) to (H) as required. (I) A method for producing a polysiloxane comprising (A) an organopolysiloxane having both molecular chain terminals and / or one molecular chain terminal terminated with silanol groups, (B) an organic divalent tin compound, and (C) a hydrolyzable organosilane compound represented by the above general formula (1) and / or a partial hydrolysis condensate thereof, wherein the silanol groups at the molecular chain terminals of the organopolysiloxane of component (A) are hydrolyzable organosilyl groups (-SiR 1 4-a (OR 2 ) a-1 a reaction mixture comprising an organopolysiloxane capped with (C) the residue of the hydrolyzable organosilane compound represented by the general formula (1) and / or its partial hydrolysis condensate, (D) a curing catalyst (excluding component (B)), (E) filler, (F) adhesion promoter (excluding component (C)), (G) plasticizers, (H) Non-sagging agent.

[0012] (A) Component: Component (A) used in the non-sag, room-temperature-curable organopolysiloxane composition of the present invention is an organopolysiloxane in which both molecular chain terminals and / or one molecular chain terminal are blocked with silanol groups (hydroxyl groups bonded to silicon atoms) (i.e., an essentially linear polymer having as its main chain an organopolysiloxane structure consisting of repeating diorganosiloxane units in which both molecular chain terminals are blocked with silanol groups or in which one molecular chain terminal is blocked with a silanol group and the other terminal is blocked with a trialkylsilyl group), and acts as the main component (base polymer) of the non-sag, room-temperature-curable organopolysiloxane composition of the present invention.

[0013] Specific examples of component (A) include essentially linear diorganopolysiloxanes represented by the following general formula (2) in which both molecular chain terminals are blocked with silanol groups, and / or essentially linear diorganopolysiloxanes represented by the following general formula (3) in which one molecular chain terminal is blocked with a silanol group. [ka] (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 that gives the diorganopolysiloxane a viscosity of 100 to 1,000,000 mPa s at 23°C. [ka] (In formula (3), R 3 A is the same as in formula (2), and n is an integer that gives the diorganopolysiloxane a viscosity of 100 to 1,000,000 mPa·s at 23°C.

[0014] In the general formulas (2) and (3), R 3 Examples of the unsubstituted or substituted monovalent hydrocarbon groups having 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, represented by the following formula (I) include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, and dodecyl groups; cycloalkyl groups such as cyclopentyl and cyclohexyl groups; vinyl, allyl, propenyl, and isopropyl groups; Examples include alkenyl groups such as isopropenyl, butenyl, pentenyl, and hexenyl; 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, those excluding aliphatic unsaturated hydrocarbon groups such as alkenyl groups are preferred, and alkyl groups such as methyl and ethyl groups and aryl groups such as phenyl are more preferred, with methyl being 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, and the divalent hydrocarbon group is -(CH2) p -or-(CH=CH) q Preferred are alkylene and alkenylene groups such as - (p represents an integer of 1 to 8, preferably an integer of 1 to 4, and q represents an integer of 1 to 4). Among these, an oxygen atom, -CH2CH2-, -CH2CH2CH2-, and -CH=CH- are preferred.

[0016] In the general formulas (2) and (3), m and n are each an integer that provides a viscosity of the diorganopolysiloxane at 23°C of 100 to 1,000,000 mPa·s. Typically, m and n are integers from 20 to 2,000, preferably from 20 to 1,600, more preferably from 20 to 1,000, and even more preferably from about 20 to 500. The viscosity of the diorganopolysiloxane 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 using a rotational viscometer (e.g., BL type, BH type, BS type, cone-plate type, etc.) (the same applies hereinafter). Furthermore, the disiloxane units (R 3 )2SiO 2 / 2 The m and n values, which indicate the number of repetitions (or degree of polymerization) of the 2-amino-2-methyl-2-propanol group, can usually be determined as the polystyrene-equivalent number-average degree of polymerization (or number-average molecular weight) in gel permeation chromatography (GPC) analysis using toluene or the like as a developing solvent.

[0017] Specific examples of the component (A) include the following: [ka] (In each formula, R 3 , m is the same as above.) [ka] (In each formula, R 3 , n is the same as above.)

[0018] The organopolysiloxane of component (A) in which both molecular chain terminals and / or one molecular chain terminal are blocked with silanol groups can be used either alone or in combination of two or more types with different structures or degrees of polymerization.

[0019] (B) Ingredients: The non-sag, room-temperature-curable organopolysiloxane composition of the present invention is characterized by containing an organic divalent tin compound (B) as a catalyst for an end-capping step in which the terminal silanol groups of the organopolysiloxane of component (A), in which both molecular chain terminals and / or one molecular chain terminal are blocked with silanol groups, are blocked (substituted) with hydrolyzable organosilyl groups derived from the hydrolyzable organosilane compound of component (C) described below and / or a partial hydrolyzed condensate thereof.

[0020] The organic divalent tin compound of component (B) is preferably a divalent tin salt of a carboxylic acid (a salt of a carboxylic acid and divalent tin(II)), and examples of such tin(II) dicarboxylate compounds include tin(II) 2-ethylhexanoate (also known as tin(II) octoate), tin(II) octanoate, and tin(II) neodecanoate. Of these, tin(II) 2-ethylhexanoate is preferred because it is readily available.

[0021] The amount of component (B) blended is preferably 0.001 to 10 parts by mass, and particularly preferably 0.01 to 1 part by mass, per 100 parts by mass of component (A). If the amount of component (B) is too small, the end-capping reaction of the terminal silanol groups of component (A) may not proceed efficiently, while if the amount is too large, problems such as gel formation during production may arise, which is disadvantageous in terms of production or economical.

[0022] (C) Ingredients: The non-sag, room-temperature-curable organopolysiloxane composition of 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 non-sag, room-temperature-curable organopolysiloxane composition of the present invention, component (C) functions as a crosslinking agent (curing agent) that caps terminals through a condensation reaction with silanol groups in the organopolysiloxane of component (A) and also forms a crosslinked structure. R 1 4-a Si(OR 2 ) a (1) (In the formula, R 1is an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and R 2 are each independently an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and a is 3 or 4.

[0023] Here, in the general formula (1), R 1 Examples of the unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms, represented by the formula (I) include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, and dodecyl groups; cycloalkyl groups such as cyclopentyl and cyclohexyl groups; vinyl groups, allyl groups, propenyl groups, and isopropyl groups. Examples include alkenyl groups such as thopenyl, butenyl, pentenyl, and hexenyl; 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 or methoxy groups, such as 3-chloropropyl, 3,3,3-trifluoropropyl, 2-cyanoethyl, and methoxymethyl. Among these, alkyl groups such as methyl and ethyl, alkenyl groups such as vinyl, and methoxymethyl groups in which one hydrogen atom of a methyl group has been substituted with a methoxy group are preferred, with methyl, vinyl, and methoxymethyl being particularly preferred.

[0024] In the general formula (1), R 2Examples of the unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms, represented by the formula (I) include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, and dodecyl groups; cycloalkyl groups such as cyclopentyl and cyclohexyl groups; vinyl groups, allyl groups, propenyl groups, and isopropyl groups. Examples include alkenyl groups such as thopenyl, butenyl, pentenyl, and hexenyl; 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 or methoxy groups, such as 3-chloropropyl, 3,3,3-trifluoropropyl, 2-cyanoethyl, and methoxymethyl. Among these, alkyl groups such as methyl and ethyl are more preferred, with methyl being particularly preferred.

[0025] Examples of component (C) include (organo)silane compounds having three or more, preferably three or four, hydrolyzable groups such as alkoxy groups in the molecule, and their partial hydrolysis condensates (i.e., (organo)siloxane oligomers having three or more residual hydrolyzable groups in the molecule, obtained by partial hydrolysis condensation of the (organo)silane compounds). Specific examples include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, methyl silicate, and ethyl silicate, and their partial hydrolysis condensates, methyltrimethoxysilane, methyltriethoxysilane, and vinyltrimethoxysilane. Examples of organotrialkoxysilanes include organotrialkoxysilanes such as silane, vinyltriethoxysilane, vinyltriisopropoxysilane, methyltris(methoxyethoxy)silane, vinyltris(methoxyethoxy)silane, methoxymethyltrimethoxysilane, methoxymethyltriethoxysilane, ethoxymethyltrimethoxysilane, and ethoxymethyltriethoxysilane, and their partial hydrolysis condensates. Particularly preferred are tetramethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane, methoxymethyltrimethoxysilane, and their hydrolysis condensates, but are not limited to these. These can be used alone or in combination of two or more.

[0026] The amount of the hydrolyzable organosilane compound and / or its partial hydrolysis condensate (C) blended per 100 parts by mass of the above-mentioned (A) component is 0.01 to 30 parts by mass, preferably 0.5 to 10 parts by mass. If the amount of component (C) is too small, sufficient rubber properties may not be obtained even after curing the composition, while if the amount is too large, rapid curing properties may be impaired or it may be economically disadvantageous.

[0027] (D) Ingredients: The component (D) according to the present invention is a curing catalyst (a non-metallic organic catalyst and / or a metallic catalyst) other than the component (B) described above, and acts to accelerate the curing of the room-temperature-curable organopolysiloxane composition according to the present invention.

[0028] The non-metallic organic catalyst used as the curing catalyst may be any known curing accelerator for condensation-curable organopolysiloxane compositions, and is not particularly limited. Examples of the non-metallic organic catalyst include phosphazene-containing compounds such as N,N,N',N',N'',N''-hexamethyl-N'''-(trimethylsilylmethyl)phosphorimidic triamide; amine compounds or salts thereof such as hexylamine and dodecylamine phosphate; quaternary ammonium salts such as benzyltriethylammonium acetate; and guanidyl group-containing silanes and siloxanes such as tetramethylguanidylpropyltrimethoxysilane, tetramethylguanidylpropylmethyldimethoxysilane, and tetramethylguanidylpropyltris(trimethylsiloxy)silane. Furthermore, the non-metallic organic catalyst may be used alone or in combination of two or more.

[0029] The metal catalyst of the curing catalyst may be any known curing accelerator for condensation curing organopolysiloxane compositions, and is not particularly limited. For example, alkyltin(IV) ester compounds such as dibutyltin(IV) diacetate, dibutyltin(IV) dilaurate, dibutyltin(IV) dioctoate, dioctyltin(IV) dineodecanoate, and di-n-butyl-dimethoxytin(IV), titanate esters or titanium chelate compounds such as tetraisopropoxytitanium, tetra-n-butoxytitanium, tetrakis(2-ethylhexoxy)titanium, dipropoxybis(acetylacetonato)titanium, titanium isopropoxyoctylene glycol, and titanium diisopropoxybis(ethylacetoacetate), zinc naphthenate, zinc stearate, zinc-2-ethyloctoate, and iron-2-ethylhexoate, Examples of metal catalysts include, but are not limited to, cobalt 2-ethylhexoate, manganese 2-ethylhexoate, cobalt naphthenate, aluminum alcoholate compounds such as aluminum isopropylate and aluminum secondary butylate, aluminum chelate compounds such as aluminum alkyl acetate diisopropylate and aluminum bisethylacetoacetate monoacetylacetonate, organometallic compounds such as bismuth(III) neodecanoate, bismuth(III) 2-ethylhexanoate, bismuth(III) citrate and bismuth octoate, and alkali metal salts of lower fatty acids such as potassium acetate, sodium acetate and lithium oxalate. Metal catalysts may be used singly or in combination.

[0030] The amount of the curing catalyst for component (D) is 0.001 to 20 parts by mass, preferably 0.01 to 10 parts by mass, per 100 parts by mass of component (A). If the amount of component (C) is too small, sufficient curing properties cannot be obtained, while if the amount is too large, the curing properties will be too rapid, resulting in insufficient working time and being economically disadvantageous. Component (D) is not blended in step [i], which will be described later, but is blended in step [ii].

[0031] (E) Ingredients: Component (E) is a filler (an inorganic filler and / or an organic resin filler), which is an optional component that is blended into the room-temperature-curable organopolysiloxane composition of the present invention as needed, and is used to impart sufficient mechanical strength to the cured product formed from this composition. Known fillers can be used, including inorganic fillers such as reinforcing silica fillers (fine powder silica, fumed silica (fumed silica or dry silica), precipitated silica (wet silica), and silica whose surface has been hydrophobized with an organosilicon compound; glass beads, glass balloons, transparent resin beads, silica aerogel, diatomaceous earth, metal oxides (such as iron oxide, zinc oxide, titanium oxide, and fumed metal oxide); quartz powder (crystalline silica); reinforcing agents (such as carbon black, talc, zeolite, and bentonite); asbestos, glass fiber, carbon fiber, calcium carbonate (such as colloidal calcium carbonate and heavy calcium carbonate), metal carbonates (such as magnesium carbonate and zinc carbonate), glass wool, finely powdered mica, and fused silica powder; and organic resin fillers such as synthetic resin powders (such as polystyrene, polyvinyl chloride, and polypropylene). Among these fillers, inorganic fillers such as silica, calcium carbonate, and zeolite are preferred, with fumed silica and calcium carbonate whose surface has been hydrophobized being particularly preferred.

[0032] When a filler (E) is added, the amount added is preferably 1 to 1,000 parts by mass, and particularly 5 to 400 parts by mass, per 100 parts by mass of the above-mentioned component (A). The cured product obtained from this composition tends to exhibit sufficient mechanical strength when added rather than when not added, but 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 tends to decrease, making it difficult to obtain rubber elasticity.

[0033] (F) Ingredients: Component (F) is an adhesion promoter (excluding component (C)), and is an optional component that is blended into the room-temperature-curable organopolysiloxane composition of the present invention as needed, and is used to impart sufficient adhesion to the cured product formed from this composition. Specifically, it is preferable to blend hydrolyzable organosilane compounds (so-called carbon functional silanes or silane coupling agents) having in the molecule a monovalent hydrocarbon group containing a functional group (excluding guanidyl groups) having a heteroatom such as a nitrogen atom, oxygen atom, or sulfur atom in addition to the hydrolyzable group, such as aminosilanes such as γ-aminopropyltriethoxysilane and 3-2-(aminoethylamino)propyltrimethoxysilane [also known as N-2-(aminoethyl)-3-aminopropyltrimethoxysilane], epoxysilanes such as γ-glycidoxypropyltrimethoxysilane and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, (meth)acrylic silanes such as γ-(meth)acryloxypropyltrimethoxysilane and γ-(meth)acryloxypropyltriethoxysilane, mercaptosilanes such as γ-mercaptopropyltrimethoxysilane, and isocyanate silanes such as γ-isocyanatopropyltrimethoxysilane. The adhesion promoter (carbon functional silane or silane coupling agent) of component (F) is clearly distinguishable from the hydrolyzable organosilane compound and / or its partial hydrolysis condensate of component (C) above in that it contains a monovalent hydrocarbon group in the molecule that contains a functional group (excluding guanidyl groups) that has a heteroatom such as a nitrogen atom, oxygen atom, or sulfur atom in addition to the hydrolyzable group (however, it does not contain organoxy-substituted alkyl groups such as methoxymethyl groups).

[0034] When the adhesion promoter of component (F) is added, the amount added is preferably 0.1 to 30 parts by mass, particularly 0.5 to 20 parts by mass, per 100 parts by mass of component (A). An amount exceeding 30 parts by mass may result in insufficient curing or may be economically disadvantageous. Component (F) is not added in step [i], which will be described later, but is added as needed, in some cases, in step [ii].

[0035] (G) Ingredients: Component (G) is a plasticizer, an optional component that may be incorporated into the room-temperature-curable organopolysiloxane composition of the present invention as needed, and it allows the viscosity of the composition to be adjusted to a level that is easy to handle during application, without impairing the mechanical properties or flame retardancy of the cured product formed from the composition.

[0036] Examples of plasticizers that can be used in the non-sag, 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 (DOM), 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, etc. Others include trimellitic acid-based plasticizers, polyester-based plasticizers, chlorinated paraffins, stearic acid-based plasticizers, silicone oils (non-functional organopolysiloxanes) such as dimethylpolysiloxanes with both molecular chain ends blocked with trimethylsilyl groups, and more recently, petroleum-based high-boiling solvents such as polyoxypropylene glycols, paraffins, naphthenes, and isoparaffins. These may be used alone or in combination of two or more. Among these, silicone oil (non-functional organopolysiloxane) is particularly preferred.

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

[0038] [ka] (In formula (4), R 4 are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 20 carbon atoms that does not contain an aliphatic unsaturated bond, and b is an integer that gives the organopolysiloxane a viscosity of 1.5 to 1,000,000 mPa s at 23°C.

[0039] In the general formula (4), R 4 are each independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 20 carbon atoms and not containing an aliphatic unsaturated bond, 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 of these groups have been substituted with halogen atoms such as F, Cl, or Br, such as a chloromethyl group, a chloropropyl group, a bromoethyl group, and a trifluoropropyl group.

[0040] In the organopolysiloxane represented by the general formula (4), the value of b, which indicates the number of repetitions of the diorganosiloxane unit (degree of polymerization), may generally be an integer of about 3 to 3,000, preferably 5 to 2,000, and more preferably 10 to 1,000. The viscosity of the organopolysiloxane at 23° C. is preferably 1.5 to 1,000,000 mPa·s, and more preferably 10 to 100,000 mPa·s.

[0041] When component (G) is included, the amount added is preferably 1 to 1,000 parts by mass, more preferably 2 to 500 parts by mass, and even more preferably 3 to 200 parts by mass, per 100 parts by mass of component (A). When the amount of component (F) is within the above range, it is possible to adjust the viscosity to a level that is easy to handle during application without impairing the mechanical properties or flame retardancy of the room-temperature-curable organopolysiloxane composition of the present invention, which is preferred.

[0042] (H) Component: Component (H) is a non-sag agent (thixotropy-imparting agent), an optional component that may be incorporated into the non-sag, room-temperature-curable organopolysiloxane composition of the present invention as needed, and it can adjust the thixotropy of the composition to make it easier to handle during application, without impairing the mechanical properties of the cured product formed from the composition.

[0043] Examples of non-sag agents that can be used in the non-sag room-temperature-curable organopolysiloxane composition of the present invention include polyether compounds such as polyethylene oxide (polyoxyethylene), polypropylene oxide (polyoxypropylene), ethylene oxide-propylene oxide copolymers (polyoxyethylene-polyoxypropylene copolymers), and polymers of these compounds whose molecular chain ends (one end or both ends) are blocked with alkyl ethers; silane-modified or silicone-modified polyether compounds; polyether phosphate esters; polyether fatty acid esters; fatty acid amide waxes; hydrogenated castor oil; and oxidized polyolefins.

[0044] When component (H) is included, the amount added is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, and even more preferably 0.1 to 2 parts by mass, per 100 parts by mass of component (A). When the amount of component (H) is within the above range, it is possible to adjust the thixotropy to facilitate handling during application without impairing the mechanical properties of the room-temperature-curable organopolysiloxane composition of the present invention, which is preferred.

[0045] Other Ingredients: The non-sagging, room-temperature-curable organopolysiloxane composition of the present invention may further contain optional additives such as storage stabilizers (storage stability improvers) such as glycerin esters of fatty acids having fatty acid ester groups, such as triacetin, diacetin, monoacetin, tributyrin, tricaprylin, tristearin, and glycerol diacetate laurate, and 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, such as trimethylolpropane tristearate, trimethylolpropane triacetate, and pentaerythritol monoacetate. Other known additives, such as pigments, dyes, antioxidants, antioxidants, antistatic agents, flame retardants, such as antimony oxide and chlorinated paraffins, may also be incorporated within the scope of the present invention. Furthermore, mildew inhibitors and antibacterial agents may also be incorporated.

[0046] Furthermore, the non-sag, room-temperature-curable organopolysiloxane composition of the present invention may contain an organic solvent, if necessary. Examples of organic solvents 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 organic solvent may be adjusted as needed to a range that does not impair the effects of the present invention.

[0047] [Method for producing non-sagging room temperature curable organopolysiloxane composition] The method for producing the non-sag, room-temperature-curable organopolysiloxane composition of the present invention includes uniformly mixing at least all of component (A), all of component (B), and some or all of component (C), excluding components (D) and (F), and converting silanol groups at the molecular chain terminals of the organopolysiloxane of component (A) into hydrolyzable organosilyl groups (—SiR 1 4-a (OR 2 ) a-1 The method is characterized by comprising a step (end-capping step) (step [i]) of preparing a reaction mixture (I) containing an organopolysiloxane blocked with (C), and a step (step [ii]) of blending the remainder of component (C), all of component (D), and optionally component (F) with the reaction mixture.

[0048] In the method for producing the non-sag, room-temperature-curable organopolysiloxane composition of the present invention, the hydrolyzable organosilane compound and / or its partial hydrolysis condensate (C) are preferably blended in step [i] at 10 to 100 mass%, particularly 30 to 100 mass%, or even 50 to 100 mass% of the total component (C), and in step [ii] at 0 to 90 mass%, particularly 0 to 70 mass%, or even 0 to 50 mass% of the total component (C). If the blending ratio in step [i] is too low, the end-capping reaction of component (A) with component (C) will not proceed sufficiently, resulting in problems such as gel formation or a sudden increase in viscosity of the composition when component (D) and, if necessary, component (F) are added together with the remainder of component (C) in step [ii] after the end-capping step [i].

[0049] In step [i], the components are mixed under substantially anhydrous conditions, at normal or reduced pressure, at room temperature to high temperature (usually 0 to 100°C, preferably 10 to 70°C), for a time of usually 5 minutes to 5 hours, preferably 10 minutes to 2 hours.

[0050] In step [i], a polysiloxane (organopolysiloxane) comprising components (A), (B), and (C) is produced, in which the silanol groups at the molecular chain terminals of the organopolysiloxane (component (A)) are converted to hydrolyzable organosilyl groups (-SiR 1 4-a (OR 2 ) a-1 A reaction mixture (I) containing an organopolysiloxane capped with .

[0051] After the end-capping step (step [i]), the remainder of component (C), all of component (D), and optionally component (F) are blended (step [ii]). Here, components (E), (G), (H), and other components may be mixed in step [ii], or may be mixed simultaneously during the end-capping step (step [i]). However, components (D) and (F) are added after the end-capping step (step [ii]) because mixing them simultaneously during the end-capping step may cause gel formation or viscosity increase. In particular, when component (F) is an aminosilane, mixing it during the end-capping step (step [i]) will cause the mixture to sag, which is disadvantageous, especially when used as an adhesive or construction sealant.

[0052] In step [ii], the components are mixed under substantially anhydrous conditions, at normal or reduced pressure, at room temperature to elevated temperatures (usually 0 to 100°C, preferably 10 to 70°C), for a period of typically 5 minutes to 5 hours, preferably 10 minutes to 2 hours.

[0053] If the terminal blocking of component (A) is insufficient in the terminal blocking step, gelation or viscosity increase may occur when components (D) and (F) are added after the terminal blocking step. However, in the case of a room-temperature-curable organopolysiloxane composition produced under the conditions described above, the terminal blocking step proceeds smoothly, and a non-sagging room-temperature-curable organopolysiloxane composition can be produced under mild conditions and in a very short time using an inexpensive organopolysiloxane having silanol groups as the terminal functional group as the starting material. This improves productivity, and the storage stability is also good, making it economically advantageous.

[0054] The non-sag, room-temperature-curable organopolysiloxane compositions obtained by the production method of the present invention cure when left at room temperature (23°C ± 15°C), and known molding methods and curing conditions can be used depending on the type of composition. In particular, one-component compositions can be stored in the absence of moisture, i.e., in a sealed container that is protected from moisture, and then readily cure at room temperature by exposing them to moisture in the air when in use.

[0055] Furthermore, the resulting cured product exhibits good flexibility and rubber elasticity, making it useful as a coating agent, adhesive, or sealant (for example, a construction sealant). The non-sag, room-temperature-curable organopolysiloxane composition obtained by the production method of the present invention can be used as a coating agent, adhesive, or sealant in any conventional manner, and is not particularly limited.

[0056] Examples of articles having a coating layer made of a cured product of the non-sag, room-temperature-curable organopolysiloxane composition obtained by the production method of the present invention include articles made of glass, various resins, various metals, etc., but there are no particular restrictions on the material and shape of the substrate.

[0057] Examples of articles that can be bonded and / or sealed with a cured product of the non-sagging room-temperature-curable organopolysiloxane composition obtained by the production method of the present invention include articles made of glass, various metals, etc., but there are no particular restrictions on the material and shape of the substrate. [Example]

[0058] The present invention will be described in detail below with reference to examples and comparative examples, 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 value measured using a rotational viscometer at 23°C. The composition was prepared at a room temperature of 23°C.

[0059] [Example 1] 100 parts of a linear dimethylpolysiloxane with a viscosity of 50,000 mPa·s and both molecular chain terminals capped with silanol groups, 40 parts of a linear dimethylpolysiloxane with a viscosity of 100 mPa·s and both molecular chain terminals capped with trimethylsilyl groups, 15 parts of fumed silica, and 0.5 parts of polyoxyethylene-polyoxypropylene copolymer monobutyl ether (Unilube C, NOF Corporation) were mixed under reduced pressure for 30 minutes. Next, 10 parts of vinyltrimethoxysilane and 0.05 parts of tin(II) 2-ethylhexanoate were added, and the mixture was mixed under reduced pressure for 30 minutes to carry out the end-capping step, in which the silanol groups at both molecular chain terminals of the linear dimethylpolysiloxane were capped with vinyldimethoxysilyl groups. The mixture was then mixed under reduced pressure, and 0.8 parts of N-2-(aminoethyl)-3-aminopropyltrimethoxysilane and 0.3 parts of dioctyltin(IV) dineodecanoate (Neostan U-830, manufactured by Nitto Kasei Co., Ltd.) were then added to the mixture, followed by mixing under reduced pressure for 15 minutes until uniform, thereby preparing Composition 1.

[0060] [Example 2] In Example 1, instead of 100 parts of linear dimethylpolysiloxane having a viscosity of 50,000 mPa·s and both molecular chain terminals blocked with silanol groups and 40 parts of linear dimethylpolysiloxane having a viscosity of 100 mPa·s and both molecular chain terminals blocked with trimethylsilyl groups, 85 parts of linear dimethylpolysiloxane having a viscosity of 10,000 mPa·s and both molecular chain terminals blocked with silanol groups and 10,000 mPa·s and both molecular chain terminals blocked with trimethylsilyl groups were used. Composition 2 was prepared in the same manner as in Example 1, except that 50 parts of a linear dimethylpolysiloxane terminated with trimethylsilyl groups and 5 parts of a dimethylpolysiloxane having a viscosity of 10,000 mPa s and terminated at both molecular chain terminals with trimethylsilyl groups were used, and 10 parts of methyltrimethoxysilane was used instead of 10 parts of vinyltrimethoxysilane to perform an end-capping step in which the silanol groups at both molecular chain terminals and one molecular chain terminal of the linear dimethylpolysiloxane were each terminated with methyldimethoxysilyl groups.

[0061] [Example 3] A terminal-capping step was carried out to cap the silanol groups at both molecular chain ends of the linear dimethylpolysiloxane with vinyldimethoxysilyl groups by mixing 100 parts of a linear dimethylpolysiloxane with a viscosity of 20,000 mPa·s and terminally terminated with silanol groups, 40 parts of a linear dimethylpolysiloxane with a viscosity of 100 mPa·s and terminally terminated with trimethylsilyl groups, 5 parts of vinyltrimethoxysilane, and 0.05 parts of tin(II) 2-ethylhexanoate for 30 minutes until homogeneous, while shielded from moisture. 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 parts of γ-aminopropyltriethoxysilane, 1 part of triacetin, and 5 parts of titanium diisopropoxybis(ethylacetoacetate) (Orgatix TC-750, manufactured by Matsumoto Fine Chemical Co., Ltd.) were added to the mixture, and the mixture was mixed under reduced pressure for 15 minutes until uniform, thereby preparing composition 3.

[0062] [Comparative Example 1] Composition 4 was prepared in the same manner as in Example 1, except that tin(II) 2-ethylhexanoate was not added. However, after adding aminosilane (N-2-(aminoethyl)-3-aminopropyltrimethoxysilane) and tin catalyst (dioctyltin(IV) dineodecanoate) in step [ii], gelation occurred in the system, and the composition could not be prepared.

[0063] Comparative Example 2 Composition 5 was prepared in the same manner as in Example 1, except that N-2-(aminoethyl)-3-aminopropyltrimethoxysilane was added during the end-capping step (in step [i]) rather than after the end-capping step (in step [ii]).

[0064] Comparative Example 3 Composition 6 was prepared in the same manner as in Example 1, except that 0.05 parts of dioctyltin(IV) dineodecanoate was added instead of 0.05 parts of tin(II) 2-ethylhexanoate during the end-capping step. However, gelation occurred in the system during the end-capping step, and the composition could not be prepared.

[0065] Comparative Example 4 Composition 7 was prepared in the same manner as in Example 1, except that 1 part of 3-aminopropyltrimethoxysilane was used instead of 0.05 parts of tin(II) 2-ethylhexanoate in Example 1. However, after adding the aminosilane (N-2-(aminoethyl)-3-aminopropyltrimethoxysilane) and the tin catalyst (dioctyltin(IV) dineodecanoate) in step [ii], gelation occurred in the system, and the composition could not be prepared.

[0066] Comparative Example 5 Composition 8 was prepared in the same manner as in Example 1, except that 1 part of a basic aminosilane compound represented by the following structural formula (5) was used instead of 0.05 parts of tin(II) 2-ethylhexanoate. However, after adding the aminosilane (N-2-(aminoethyl)-3-aminopropyltrimethoxysilane) and the tin catalyst (dioctyltin(IV) dineodecanoate) in step [ii], gelation occurred in the system, and the composition could not be prepared. [ka]

[0067] Comparative Example 6 Composition 9 was prepared in the same manner as in Example 3, except that tin(II) 2-ethylhexanoate was not added.

[0068] [Evaluation test] The tack-free time was measured for each of the compositions prepared in Examples 1 to 3 and Comparative Examples 2 and 6. Immediately after preparation, each of the compositions prepared in Examples 1 to 3 and Comparative Examples 2 and 6 was extruded into a 2 mm thick sheet and exposed to air at 23°C and 50% RH. The sheet was then left in the same atmosphere for 7 days, and the physical properties of the resulting cured product (initial physical properties: hardness, elongation at break, and tensile strength) were measured in accordance with JIS K 6249. Hardness was measured using a JIS K 6249 Durometer A hardness tester.

[0069] [Non-sagging] Using each of the compositions prepared in Examples 1 to 3 and Comparative Examples 2 and 6, a vertical slump test in accordance with JIS A 1439 was carried out at 23°C. If the measured distance was within 3 mm, it was evaluated as ○ (pass), and if it was greater than 3 mm, it was evaluated as × (fail).

[0070] [Storage stability] Each composition prepared in Examples 1 to 3 and Comparative Examples 2 and 6 was placed in a polyethylene sealant cartridge (volume 330 mL), and the cartridge was sealed with an inner stopper. The cartridge was stored in a dryer at 70°C for 7 days, then removed and the tack-free time was measured in the same manner as above. If the time required was within twice that of each composition after preparation, it was evaluated as ○ (pass), and if it took more than twice as long, it was evaluated as × (fail).

[0071] The results are shown in Table 1.

[0072] [Table 1]

[0073] The results in Table 1 reveal that in Examples 1 to 3, the cured compositions were easier to prepare than in Comparative Examples 1 to 6, and the non-sagging properties and storage stability were also good.

[0074] The present invention is not limited to the above-described embodiments. The above-described embodiments are merely examples, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits similar effects is included within the technical scope of the present invention.

Claims

1. (A) organopolysiloxane having both molecular chain ends and / or one molecular chain end blocked with silanol groups: 100 parts by mass, (B) Organic divalent tin compound: 0.001 to 10 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 halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and R 2 are each independently an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and a is 3 or 4. and / or a partial hydrolysis condensate thereof: 0.01 to 30 parts by mass, (D) curing catalyst (excluding component (B)): 0.001 to 20 parts by mass, (E) filler: 1 to 1,000 parts by mass, and (F) Adhesion promoter (excluding component (C)): 0 to 30 parts by mass A method for producing a room-temperature-curable organopolysiloxane composition having non-sagging properties, comprising: [i]: Components (A) and (E) are premixed, and then components (B) and some or all of component (C) are added to the premix. The mixture is then mixed uniformly to convert the silanol groups at the molecular chain terminals of the organopolysiloxane of component (A) into hydrolyzable organosilyl groups (—SiR 1 4-a (OR 2 ) a-1 (provided that components (D) and (F) are not included in step [i]), and [ii]: A step of blending the remainder of the component (C), the component (D), and optionally the component (F) with the mixture. A method for producing a non-sag, room-temperature-curable organopolysiloxane composition comprising:

2. 2. The method for producing a non-sag, room-temperature-curable organopolysiloxane composition according to claim 1, wherein 10 to 100% by mass of the total component (C) is blended in step [i], and 0 to 90% by mass of the total component (C) is blended in step [ii].

3. Furthermore, relative to 100 parts by mass of component (A), (G) Plasticizer: 1 to 1,000 parts by mass, and (H) Anti-sag agent: 0.01 to 10 parts by mass 3. The method for producing a non-sag, room-temperature-curable organopolysiloxane composition according to claim 1, wherein one or more selected from the following are blended in step [i] and / or step [ii].

4. 4. The method for producing a non-sag, room-temperature-curable organopolysiloxane composition according to claim 1, wherein component (B) is tin(II) 2-ethylhexanoate.

5. 5. The method for producing a non-sag, room-temperature-curable organopolysiloxane composition according to any one of claims 1 to 4, wherein component (A) is a diorganopolysiloxane represented by the following general formula (2) in which both molecular chain terminals are capped with silanol groups and / or a diorganopolysiloxane represented by the following general formula (3) in which one molecular chain terminal is capped with a silanol group: 【Chemical 1】 (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 that provides a viscosity of the diorganopolysiloxane at 23°C of 100 to 1,000,000 mPa·s. 【Chemistry 2】 (In formula (3), R 3 A is the same as in formula (2), and n is an integer that gives the diorganopolysiloxane a viscosity of 100 to 1,000,000 mPa·s at 23°C.

6. R in general formula (1) 2 6. The method for producing a non-sag, room-temperature-curable organopolysiloxane composition according to claim 1, wherein R is an alkyl group having 1 to 10 carbon atoms.

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