TWI424027B - Room temperature hardening organopolysiloxane composition - Google Patents

Description

Room temperature hardening organic polyoxyalkylene composition

The present invention relates to an extremely long operation time, and has no volatilization of a reactive decane compound when it is not hardened, and is suitable for use as a room temperature hardening organic group for a sealant, an adhesive, a coating agent or a canning agent. Polyoxane composition.

Condensation hardening type polysulfide sealant, adhesive, coating agent, and pot making agent, widely used in construction and electricity. Electronics, conveyors, electrical components, home appliances, and other fields. The condensed hardening type polysulfide-type sealant, the adhesive, the coating agent, and the can-forming composition used in such applications generally employ an organic compound having at least three hydrolyzable groups bonded to a ruthenium atom in one molecule. The hydrazine compound and/or its partial hydrolyzate is used as a crosslinking agent. This is essentially a trifunctional hydrolyzed decane and/or a partial hydrolyzate thereof, specifically, an alkyltrimethoxyalkane, an alkyltributoxydecane, an alkyltriethoxydecane, an alkane. Triisopropoxy decane, or a partial hydrolyzate thereof. These reactive decanes are highly reactive and are suitable for meeting the rapid hardenability requirements of most of the above applications. However, the coating of large-area structures such as roof waterproofing, roof coating waterproofing, underwater structural coatings, ship bottom coatings, wall coatings, or the position of the adhering objects after sealing, adhesion, coating, and canning When the surface is trimmed, etc., it is necessary to use an extremely long operating time of more than 24 hours, and it is difficult to obtain such a long usable operation time.

Moreover, the decane monomer component and the low molecular siloxane oligomer obtained from the crosslinking agent which are not hardened are heated after the hardening is completed, resulting in shape change, rejection of the organic coating, short circuit of the electrical contact, Poor electrical conductivity, wet and slippery operation, etc. In the past, the main reason for this was considered to be a low molecular cyclic oxirane contained in a matrix polymer. However, the removal of low molecular cyclic oxiranes from matrix polymers has not been fully resolved. The reason for the volatile decane monomer component derived from the crosslinking agent is also the cause.

The condensing-curing type of the fluorinated sulphur-sealing material which has a sufficiently long period of use, and the patency of the condensing-curing type of the fluorinated sulphur-sealing material, which is a long-term use, is disclosed in JP-A-51-62850, JP-A-52-108796, JP-A-55-92761 (Patent Documents 1 to 3) The deamined oxygen type composition described. However, the deaminated oxygen type composition, when hardened, produces a odor characteristic of a dialkylhydroxylamine; and, in addition, a good cured product is obtained, and the limit of the usable time is 12 to 24 hours. In order to further extend the usable time, a method of adding a volatile organic oxa oxane, a volatile organic oxa oxane, is disclosed in the patents No. 2,974,231, and JP-A-2001-181508 (Patent Documents 4 and 5). It is caused by pollution around the area and volume shrinkage after hardening. In place of the low odor composition of the deaminated oxygen type composition, there is a dealcoholization type composition and the like. JP-A-39-27643 (Patent Document 6) is a representative example, and a composition of an organopolysiloxane having a hydroxyl group terminal, an alkoxysilane, and an organotitanium compound is disclosed.

Further, JP-A-55-43119 (Patent Document 7) includes an organopolysiloxane having an alkoxymethyl sulfonyl group terminal, an alkoxy decane, and an alkoxide oxime. Revealing. Japanese Patent Publication No. Hei 7-39547 (Patent Document 8) discloses an organopolysiloxane having a terminal group blocked by a vinyl group-containing alkoxymethyl sulfonyl group, an alkoxy decane, and a titanium alkoxide. The disclosure of the composition. Further, JP-A-62-207369 (Patent Document 9) includes an organopolysiloxane which is blocked by an alkoxymethyl sulfonyl group, a hydroxyl-terminated organic polyoxyalkylene, and an alkoxydecane. And the disclosure of the composition of titanium to improve oil swellability and storage. These dealcoholized compositions are improved by reviewing various methods such as production methods, storage stability (inhibition over time), oil swell resistance, and the like, particularly from storage stability regarded as a characteristic of a dealcoholic composition. From the viewpoint of the above, a so-called one-liquid type composition which does not have a deep hardenability which is stable in the absence of moisture is emphasized. Relative to this, there is no detailed review of the two-liquid type composition with deep hardenability.

A two-liquid form of a dealcoholized RTV composition, which is disclosed in Japanese Patent No. 2,784,045 (Patent Document 10), an organopolysiloxane having a terminal blocked by a stanol group, a trialkoxysilane, and a partial hydrolysis thereof. The disclosure of the composition of the material, calcium carbonate, and organometallic catalyst. Further, Patent No. 3,210,424 (Patent Document 11) includes an organopolysiloxane having a terminal blocked by a stanol group, a trioxane having two alkoxy groups, a tris or a tetraalkoxydecane. And the disclosure of the composition of the partial hydrolyzate and the hardening catalyst; all of which use alkoxy decane as the crosslinking agent, it is necessary to reduce the amount of the catalyst to ensure sufficient use time, so that sufficient mechanical equipment cannot be obtained. Physical properties.

Patent Document 1: Japanese Laid-Open Patent Publication No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. Japanese Laid-Open Patent Publication No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. Patent Document 10: Patent No. 2,784,045, Patent Document 11: Patent No. 3,210,424

The present invention has been made in view of the above problems to provide an easy operation time for ensuring extremely long operation, and is not suitable for use as a two-liquid type RTV due to uncomfortable composition of a decane monomer derived from a volatile crosslinking agent. A room temperature curable organopolysiloxane composition having a good rubber-elasticity is obtained for the purpose.

In order to achieve the above object, the working colleagues of the present invention have found that: (A) the diorganopolyoxyalkylene having two ends of the molecular chain blocked by hydroxy: 100 parts by mass, (B) in the molecular chain Polysiloxane having a hydrolyzable formyl group bonded through an alkyl group: 1 to 200 parts by mass, (C) catalyst: 0.01 to 10 parts by mass, a room temperature curable organopolysiloxane composition, easy Ensuring extremely long operating time, all without the uncomfortable composition of decane monomer from volatile cross-linking agents, and thus obtaining a hardened rubber with good rubber elasticity, suitable for use as sealant, viscosity agent, coating Agents, cans, etc. That is, it has been found that alkoxysilane and a partial hydrolyzate thereof are used as a crosslinking agent, and the usable time is ensured in terms of the amount of the catalyst, and a polymer alkoxy group having a low reactivity of the crosslinking agent itself is used. In place of the decane, it is possible to obtain a room temperature curable organopolysiloxane composition which can be used for a sufficient period of time and mechanical properties after hardening, and the present invention has been completed.

Accordingly, the present invention provides a room temperature curable organopolysiloxane composition shown below.

[1] A room temperature curable organopolysiloxane composition characterized by: (A) a diorganopolyoxyalkylene having two ends of a molecular chain blocked by a hydroxyl group: 100 parts by mass, (B) a molecular chain The polysiloxane having a hydrolyzable formyl group bonded through an alkyl group: 1 to 200 parts by mass, and (C) a catalyst: 0.01 to 10 parts by mass.

[2] The room temperature curable organopolysiloxane composition according to [1], wherein the component (A) is a diorganopolyoxyalkylene represented by the following general formula (1).

HO(R ₂ SiO) _k H (1)

(wherein R is the same or different unsubstituted or substituted one-valent hydrocarbon group; k is an integer of 10 or more.)

[3] The room temperature curable organopolysiloxane composition according to [1] or [2], wherein the component (B) is selected from the group consisting of the following general formulas (2) to (4). One or more of the alkane.

(R ¹ O) _m R ² _{3 - m} Si-R ³ -(R ₂ SiO) _j -R ₂ Si-R ³ -SiR ² _{3 - m} (OR ¹ ) _m (2)

(wherein R ¹ is the same or a different alkyl group having 1 to 6 carbon atoms or an alkoxyalkyl group having 2 to 10 carbon atoms; and R ² is the same or different unsubstituted or substituted one-valent hydrocarbon group; R ³ is an alkylene group having 1 to 12 carbon atoms; m is an integer of 1 to 3; n is an integer of 1 or more; j is an integer of 10 or more; and h is an integer of 2 or more.)

[4] The room temperature curable organopolysiloxane composition according to any one of [1] to [3], which further contains 1 to 500 parts by mass based on 100 parts by mass of the component (A). (D) filler.

[5] The room temperature curable organopolysiloxane composition according to [4], wherein the filler of the component (D) is selected from the group consisting of aerosolous cerium oxide, sedimentary cerium oxide, and calcium carbonate.

[6] The room-temperature-curable organic fluorene oxide composition according to any one of [1] to [5], which is used as a sealant, an adhesive, a coating agent or a can.

[embodiment of the invention] [(A) ingredients]

(A) The diorganopolysiloxane having both ends of the molecule blocked by a hydroxyl group is preferably a diorganopolyoxyalkylene represented by the following general formula (1).

HO(R ₂ SiO) _k H (1)

(wherein R is the same or different unsubstituted or substituted one-valent hydrocarbon group; k is an integer of 10 or more.)

In the above formula (1), R is an independently unsubstituted or substituted monovalent hydrocarbon group; an alkyl group having 1 to 20 carbon atoms, particularly 1 to 6 carbon atoms, and an alkenyl group having 2 to 20 carbon atoms, especially 2 to 6 carbon atoms. An aryl group having 6 to 20 carbon atoms, particularly 6 to 12, or a group in which a part of the hydrogen atoms is replaced by a halogen atom. Specifically, the alkyl group has a methyl group, an ethyl group, a propyl group, a cyclohexyl group or the like; the alkenyl group has a vinyl group, an allyl group, the like; the aryl group has a phenyl group; the halogen atom has a substituent of 3, 3, 3 Trifluoropropyl and the like. Further, k is an integer of 10 or more, and the viscosity of the diorganopolyoxyalkylene at 25 ° C is up to 100,000 to 100,000 mPa. The range of s is better, preferably up to 100~50,000 mPa. The range of s.

Further, the diorganopolyoxyalkylene represented by the above formula (1) has a viscosity at 25 ° C of 10 to 1,000,000 mPa. s range, from 100 to 500,000 mPa. The range of s is better. Not up to 10mPa. When s, hardened material (rubber) can not obtain sufficient mechanical properties; more than 1 million mPa. When s is increased, the viscosity of the composition is increased, and the workability is deteriorated. Here, the viscosity is measured by a rotational viscometer.

[(B) ingredients]

(B) a hydrolyzable formyl group bonded through an alkyl group in the molecular chain of the component, preferably 2 to 10, more preferably 2 to 5 polyoxyalkylene, which acts as a component of the composition Co-agents. The polyoxane of the component (B) is preferably one or more selected from the group consisting of polyoxanes represented by the following general formulas (2) to (4).

(R ¹ O) _m R ² _{3 - m} Si-R ³ -(R ₂ SiO) _j -R ₂ Si-R ³ -SiR ² _{3 - m} (OR ¹ ) _m (2)

(wherein R ¹ is the same or a different alkyl group having 1 to 6 carbon atoms or an alkoxyalkyl group having 2 to 10 carbon atoms; and R ² is the same or different unsubstituted or substituted one-valent hydrocarbon group; R ³ is an alkylene group having 1 to 12 carbon atoms; m is an integer of 1 to 3; n is an integer of 1 or more; j is an integer of 10 or more; and h is an integer of 2 or more.)

In the above formula, R ¹ is the same or a different alkyl group having 1 to 6 carbon atoms or an alkoxyalkyl group having 2 to 10 carbon atoms; the alkyl group is a methyl group, an ethyl group, a propyl group, a cyclohexyl group or the like; The oxyalkyl group has a methoxymethyl group, an ethoxymethyl group, a propoxymethyl group, a butoxymethyl group, a pentoxymethyl group, a hexyloxymethyl group, a heptyloxymethyl group, a methoxy group. Ethyl, ethoxyethyl, propoxyethyl, butoxyethyl, pentyloxyethyl, hexyloxyethyl, methoxypropyl, ethoxypropyl, propoxypropyl , butoxypropyl, methoxybutyl, ethoxybutyl, propoxybutyl, methoxypentyl, ethoxypentyl, methoxyhexyl, methoxyheptyl and the like.

Further, R ² is the same or a different unsubstituted or substituted one-valent hydrocarbon group; an alkyl group having 1 to 20 carbon atoms, particularly 1 to 6 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, especially 2 to 6 carbon atoms, carbon An aryl group of 6 to 20, especially 6 to 12, or a group of such a hydrogen atom, which is substituted by a halogen atom. Specifically, the alkyl group has a methyl group, an ethyl group, a propyl group, a cyclohexyl group or the like; the alkenyl group has a vinyl group, an allyl group, the like; the aryl group has a phenyl group; and the halogen atom has a substituent of 3, 3, and 3 Fluoropropyl group and the like.

R ³ is an alkylene group having 1 to 12 carbon atoms, especially 1 to 6 carbon atoms; specifically, a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, and the like.

m is an integer of 1 to 3; n is an integer of 1 or more, preferably an integer of 1 to 5; j is an integer of 10 or more, preferably 100 or more; h is an integer of 2 or more, preferably 2 to 10 .

Further, the (B) component polyoxyalkylene has a viscosity of 10 to 1 million mPa at 25 ° C. s range, from 100 to 500,000 mPa. The range of s is better. When the viscosity is too small, the cured product (rubber) may not have sufficient mechanical properties; when the viscosity is too large, the viscosity of the composition is increased, and the workability is lowered. Here, the viscosity is a value measured by a rotational viscometer.

The present crosslinking agent may be obtained by having a hydrocarbyl alkyl group with an alkoxy group in a corresponding alkenyl alkane, or an alkenyl group having an alkenyl group or an alkoxy group in a corresponding hydroquinone. It is easily obtained by carrying out an additional reaction in the presence of a catalyst.

The amount of the polyoxane to be used in the component (B) is from 1 to 200 parts by mass, preferably from 3 to 150 parts by mass, per 100 parts by weight of the component (A). When it is less than 1 part by mass, sufficient rubber physical properties cannot be obtained. When it exceeds 200 parts by mass, the deep hardenability of the composition is lowered, and workability is lowered.

[(C) ingredients]

The hardening catalyst of the component (C) is used as a catalyst for the reaction of the component (A) with the component (B) in the composition of the present invention. Among them are tin ester compounds such as tin dioctoate; alkyl tin ester compounds such as dibutyltin diacetate, dibutyltin di(dodecyl) acid ester, dibutyltin dioctanoate; titanium tetraisopropoxide, tetra-n-butyl Titanate or titanium clamp compound such as titanium oxytitanate, tetrakis(2-ethylhexyloxy)titanium, dipropoxy bis(acetoxime) titanium, titanium isopropoxyoctanediol; zinc naphthenate , zinc stearate, zinc-2-ethyloctanoate, iron-2-ethylhexanoate, cobalt-2-ethylhexanoate, manganese-2-ethylhexanoate, cobalt naphthenate An organometallic compound such as an alkoxy aluminum compound; an aminoalkyl substituted alkane such as 3-aminopropyltriethoxydecane or N-β(aminoethyl)-γ-aminopropyltrimethoxydecane An oxane, an amine compound such as hexylamine, dodecylamine phosphate, tetramethylguanidine or dioxanedioxane; and a salt thereof; a quaternary ammonium salt such as benzyltriethylammonium acetate; potassium acetate or acetic acid a lower fatty acid salt of an alkali metal such as sodium or lithium oxalate; a dialkylhydroxylamine such as dimethylhydroxylamine or diethylhydroxylamine; tetramethylmercaptopropyltrimethoxydecane or tetramethylmercaptopropylamine Dimethyl A decyl-containing decane or a decane or the like such as oxydecane or tetramethylmercaptopropyltris(trimethylformamoxy)decane. In particular, an amine compound such as tetramethylguanidine or dioxanecyclodecane; tetramethylmercaptopropyltrimethoxydecane, tetramethylmercaptopropylmethyldimethoxydecane, tetramethylguanidin A decane or a decane having a mercapto group such as a tris(trimethylmethaneoxy) decane; a tin ester compound; an alkyl tin ester compound or the like is preferably used. These may be used alone or in combination of two or more.

In addition, the amount of the hardening catalyst is 0.01 to 10 parts by mass, preferably 0.05 to 5 parts by mass, per 100 parts by mass of the component (A). When it is less than 0.01 part by mass, sufficient hardening properties are not obtained; when it exceeds 10 parts by mass, the durability of the composition is lowered.

[(D) ingredients]

The filler of the component (D) is a reinforcing agent or a bulking agent in the composition of the present invention. The filler is specifically a surface treated or untreated aerosolized cerium oxide, wet cerium oxide, sedimentary cerium oxide, metal oxide, metal hydroxide, glass beads, glass hollow spheres, resin beads, Resin hollow spheres, etc. It is preferred to use aerosolous cerium oxide, sedimentary cerium oxide or calcium carbonate. These may be used alone or in combination of two or more.

The amount of the filler to be added is preferably from 1 to 500 parts by mass, more preferably from 5 to 250 parts by mass, per 100 parts by mass of the component (A). When it is less than 1 part by mass, the effect as a reinforcing agent or a bulking agent may not be obtained. When the amount is more than 500 parts by mass, the discharge property of the composition is lowered and the workability is deteriorated.

[other ingredients]

When the composition of the present invention is required to have adhesiveness, it is preferred to blend a decane coupling agent which imparts an adhesive component. The decane coupling agent can be used by those skilled in the art. In particular, those having a hydrolyzable group such as an alkoxymethyl group or an alkenyl group. There are vinyl tris(β-methoxyethoxy)decane, γ-methylpropoxypropyltrimethoxydecane, β-(3,4-epoxycyclohexyl)ethyltrimethoxydecane, γ - glycidoxypropyltrimethoxydecane, γ-glycidoxypropylmethyldiethoxydecane, N-β-(aminoethyl)γ-aminopropyltrimethoxydecane , γ-aminopropyltriethoxydecane, γ-mercaptopropyltrimethoxydecane, γ-glycidoxypropyltriisopropoxydecane, γ-glycidoxypropylmethyl Diisopropoxydecane, and the like. It is more preferable to use an amine-based decane coupling agent.

The blending amount of the decane coupling agent is 0.1 to 20 parts by mass, more preferably 0.2 to 10 parts by mass, per 100 parts by mass of the component (A). When it is less than 0.1 part by mass, sufficient adhesion may not be obtained; when it exceeds 10 parts by mass, there is a case where the price is unfavorable.

Further, in the composition of the present invention, in addition to the above components, generally known additives can be used without departing from the scope of the object of the present invention. Adding a polyether as a thixotropic enhancer, a polyphthalic acid oil and a heterogeneous paraffin as a plasticizer, and a trimethylmethaneoxy unit and a SiO ₂ unit as a crosslinking density enhancer Reticulated polyoxane and the like. According to the demand, it is also possible to add a coloring agent such as a pigment, a dye, a fluorescent whitening agent, a fungicide, an antibacterial agent, a cockroach repellent, a marine biocrap and other physiologically active additives, and as a phenyl polyfluorene oil for precipitation oil. A surface modifying agent such as a chlorinated polyoxygenated oil, a polyfluorene oxide and an incompatible organic liquid, a solvent such as toluene, xylene, a solvent volatile oil, cyclohexane, methylcyclohexane or a low-boiling isoparaffin.

The composition of the present invention may be used as a one-liquid type in addition to (A), (B), (C), and (D) components as required, and may also be a component (B) and (C). Packed separately, used as a two-liquid type. For example, (A), (B), (D) components and (A), (C), (D) components of the two liquid type, or (A), (B), (D) components and (C) components The second liquid type. By using the two-liquid type, storage stability is ensured.

The organopolysiloxane composition of the present invention can be obtained by uniformly mixing the above components (A) to (C), the desired component (D), and other components in a usual manner.

The organopolysiloxane composition of the present invention thus obtained is very slow to cure, thereby ensuring an extremely long operation time; and, in the absence of volatilization of the reactive decane compound in the case of uncured, it is suitably used. Sealant, adhesive, coating agent, canning agent, etc.

Further, the curing conditions of the organic polysiloxane composition can be the same as those in the case of a room temperature curable condensed hardening type polyoxyethylene rubber composition. Generally, it is preferably used in an environment of a temperature of 5 to 40 ° C and a humidity of 10 to 90% RH.

[Examples]

The present invention will be specifically described below by way of examples and comparative examples. The invention is not limited to the embodiments described below. Further, in the following examples, the viscosity was measured at 25 ° C by a rotational viscosity meter.

[Example 1]

The viscosity at the two ends is closed by the hydroxyl group of 700mPa. 100 parts by mass of dimethyl dimethyl polyoxane, and the viscosity of the terminal end of the ruthenium vinyl group blocked by trimethoxymethyl sulfonyl group is 700 mPa. To 25 parts by mass of dimethyl dimethyl siloxane, 0.2 parts by mass of tin dioctoate was added and uniformly mixed to prepare a composition 1.

[Example 2]

In addition to the first embodiment, the two ends are blocked by a ruthenium vinyl group with a viscosity of 700 mPa. The composition 2 was prepared in the same manner as in Example 1 except that the dimethyl polysiloxane was changed to 50 parts by mass.

[Comparative Example 1]

In addition to Example 1, 5 parts by mass of methyltrimethoxydecane was used to replace the two ends of the ruthenium vinyl group with a viscosity of 700 mPa blocked with trimethoxymethyl sulfonyl group. A composition 3 was prepared in the same manner as in Example 1 except that 25 parts by mass of dimethyl dimethylpolysiloxane was used.

The composition of the examples and the comparative examples was placed in a glass container, and the curability was confirmed under an atmosphere of 23 ± 2 ° C and 50 ± 5% RH. Further, after curing for 1 day, it was heated at 150 ° C to confirm the composition. Shape maintenance. The results are shown in Table 1.

[Example 3]

The viscosity at the two ends is closed by a hydroxyl group of 50,000 mPa. 35 parts by mass of dimethyl methacrylate, 40 parts by mass of colloidal calcium carbonate, and a viscosity of 100 mPa blocked by trimethylmethane oxide at both ends. 25 parts by mass of s dimethyl polyoxane and a viscosity of 30,000 mPa blocked by trimethoxycarbenyl groups at both ends. To 20 parts by mass of dimethyl dimethyl polyoxane, 0.2 parts by mass of tin dioctoate was added and mixed, that is, the composition 5 was prepared.

[Example 4]

In the same manner as in Example 3, except that 0.2 parts by mass of dioctyltin dioctanoate was used instead of 0.2 part by mass of dioctyltin bis(dodecanoate), the composition 5 was prepared.

[Comparative Example]

In addition to Example 5, 5 parts by mass of methyltrimethoxydecane, instead of the two ends, the viscosity of 30,000 mPa is blocked by trimethoxycarbenyl through the vinyl group. A composition 6 was prepared in the same manner as in Example 3 except that 20 parts by mass of dimethyl dimethyl polyoxane was used.

[Example 5]

In addition to Example 3, the two ends were blocked by a fluorenyl vinyl group with a trimethoxymethyl sulfonyl group, and then the sterol group was passed through a fluorenyl group having a trimethoxycarbyl group having a viscosity of 30,000 mPa. 20 parts by mass of dimethyl dimethyl polyoxane, which has a viscosity of 30,000 mPa which is blocked by trimethoxymethyl sulfonyl group through the ruthenium vinyl group at both ends. A composition 7 was prepared in the same manner as in Example 3 except that 20 parts by mass of dimethyl dimethylpolysiloxane was used.

The composition of the examples and the comparative examples was placed in a glass container, and the curability was confirmed under an atmosphere of 23 ± 2 ° C and 50 ± 5% RH. Further, after curing for 1 day, it was heated at 150 ° C to confirm the composition. Shape maintenance. Further, a sheet having a thickness of 2 mm was produced, and after hardening for 7 days in an atmosphere of 23 ± 2 ° C and 50 ± 5% RH, the rubber physical properties were measured in accordance with JIS-K-6249. The results are shown in Table 2.

[Effect of invention]

The room temperature curable organopolysiloxane composition of the present invention is easy to ensure an extremely long operation time, and has no good discomfort due to the component of the decane monomer derived from the volatile crosslinking agent, thereby obtaining good A rubber-elastic cured product suitable for use as a sealant, an adhesive, a coating agent, a can-making agent, or the like.

Claims (4)

A room temperature curable organopolysiloxane composition characterized by comprising: (A) a general chain of the following formula (1), having a viscosity at 25 ° C of 10 to 100,000 mPa ‧ at both ends of the molecular chain Diorganopolyoxyalkylene blocked by a hydroxyl group: 100 parts by mass, HO(R ₂ SiO) _k H (1) (wherein R is the same or different unsubstituted or substituted one-valent hydrocarbon group; k is 10 The above integers) and (B) are one or more selected from the group consisting of polyoxoxanes having a hydrolyzable formyl group bonded through an alkyl group in the molecular chain represented by the following general formulas (2) to (4). Crosslinking agent: 1 to 200 parts by mass, (R ¹ O) _m R ² _3-m Si-R ³ -(R ₂ SiO) _j -R ₂ Si-R ³ -SiR ² _3-m (OR ¹ ) _m (2) (In the formulae (2) to (4), R is the same or a different unsubstituted or substituted one-valent hydrocarbon group, and R ¹ is the same or different alkyl group having 1 to 6 carbon atoms or a carbon number of 2 to 10 Alkoxyalkyl; R ² is the same or different unsubstituted or substituted monovalent hydrocarbon group; R ³ is a C 1~12 alkylene group; m is an integer from 1 to 3; n is an integer of 1 or more ; j is an integer of 10 or more; h is an integer of 2 or more), (C) Catalyst: 0.01 to 10 parts by mass, except that the alkoxydecane and a partial hydrolyzate thereof are not used as a crosslinking agent. The room temperature curable organopolysiloxane composition according to the first aspect of the invention, further comprising (D) a filler in an amount of from 1 to 500 parts by mass based on 100 parts by mass of the component (A). The room temperature curable organopolysiloxane composition according to claim 2, wherein the filler of the component (D) is selected from the group consisting of aerosolous cerium oxide, sedimentary cerium oxide and calcium carbonate. A room temperature curable organopolysiloxane composition according to claim 1 which is a sealant, an adhesive, a coating agent or a potting agent.