阅读说明：本技术 室温固化性有机聚硅氧烷组合物及其制造方法 (Room temperature curable organopolysiloxane composition and method for producing same ) 是由 朴字龙 尹东燮 岩崎功 于 2020-04-01 设计创作，主要内容包括：本发明涉及室温固化性有机聚硅氧烷组合物,其含有：(A)两末端羟基封端二有机聚硅氧烷、相对于二有机聚硅氧烷中的与硅原子键合的羟基1摩尔成为0.01～0.5摩尔的量的含有羟基的烃系化合物和成为(A)成分整体的0.01～1质量％的量的氯铂酸六水合物的反应生成物100质量份、(B)无机填料：3～300质量份、(C)在1分子中具有至少3个水解性基团的有机硅烷和/或其部分水解缩合物：1～20质量份、(D)缩合固化催化剂：0.01～5质量份、(E)硅烷偶联剂(但不包括(C)成分和(D)成分)：0.1～5质量份,形成长期维持低弹性模量的橡胶弹性并且对天然石材、涂装铝等的污染少的固化物。(The present invention relates to a room temperature-curable organopolysiloxane composition comprising: (A) 100 parts by mass of a reaction product of a diorganopolysiloxane capped at both terminal hydroxyl groups, a hydroxyl group-containing hydrocarbon compound in an amount of 0.01 to 0.5 mol relative to 1 mol of silicon atom-bonded hydroxyl groups in the diorganopolysiloxane, and chloroplatinic acid hexahydrate in an amount of 0.01 to 1 mass% of the whole of component (a), (B) an inorganic filler: 3 to 300 parts by mass of (C) an organosilane having at least 3 hydrolyzable groups in 1 molecule and/or a partial hydrolysis-condensation product thereof: 1-20 parts by mass of (D) a condensation curing catalyst: 0.01 to 5 parts by mass of (E) a silane coupling agent (excluding the component (C) and the component (D)): 0.1 to 5 parts by mass, and forms a cured product which maintains rubber elasticity with low elastic modulus for a long time and has little pollution to natural stone, coated aluminum and the like.)

1. A room-temperature-curable organopolysiloxane composition comprising:

(A) the reaction products of the following (i), (ii) and (iii): 100 parts by mass of a water-soluble polymer,

(i) a diorganopolysiloxane represented by the following general formula (1),

[ solution 1]

Wherein R is the same or different unsubstituted or substituted 1-valent hydrocarbon group, a is an integer of 10 or more,

(ii) a hydrocarbon compound containing a hydroxyl group represented by the following general formula (2): the amount thereof being such that the amount thereof is 0.01 to 0.5 mol relative to 1 mol of the silicon atom-bonded hydroxyl groups in the diorganopolysiloxane of the component (i), and

R¹-OH (2)

in the formula, R¹Is the same or different unsubstituted or substituted 1-valent alkyl with 3 to 20 carbon atoms,

(iii) chloroplatinic acid hexahydrate: the amount thereof being 0.01 to 1% by mass of the whole of the component (A),

(B) inorganic filler: 3 to 300 parts by mass of a stabilizer,

(C) an organosilane having at least 3 hydrolyzable groups in 1 molecule and/or a partial hydrolytic condensate thereof: 1 to 20 parts by mass of a stabilizer,

(D) condensation curing catalyst: 0.01 to 5 parts by mass of a stabilizer,

(E) a silane coupling agent, excluding the (C) component and the (D) component: 0.1 to 5 parts by mass.

2. The room-temperature-curable organopolysiloxane composition according to claim 1, wherein the content of the nonfunctional silicone oil in the room-temperature-curable organopolysiloxane composition is 0% by mass or more and less than 10% by mass.

3. The room-temperature-curable organopolysiloxane composition according to claim 1 or 2, wherein the inorganic filler of component (B) contains fumed silica and/or calcium carbonate.

4. The room-temperature-curable organopolysiloxane composition according to any one of claims 1 to 3, wherein the silane coupling agent of component (E) is an amine-based silane coupling agent having an alkoxysilyl group as a hydrolyzable group.

5. The room-temperature-curable organopolysiloxane composition according to any one of claims 1 to 4, which forms a silicone rubber cured product having a type A durometer hardness of 10 to 30 and an elongation at break of 500% or more, as specified in JIS K6249.

6. The room-temperature-curable organopolysiloxane composition according to any one of claims 1 to 5, which forms a silicone rubber cured product having an amount of components extracted into a toluene layer by immersion in toluene for 24 hours of 10 mass% or less.

7. The room-temperature-curable organopolysiloxane composition according to any one of claims 1 to 6, which is used for a sealing material for buildings.

8. A method for producing a room-temperature-curable organopolysiloxane composition, comprising the steps of: after mixing the following (i), (ii) and (iii) at 0 ℃ to 50 ℃ for 5 minutes or more to produce a reaction product (A), the following (B), (C), (D) and (E) are uniformly mixed with respect to 100 parts by mass of the reaction product (A),

(i) a diorganopolysiloxane represented by the following general formula (1),

[ solution 2]

Wherein R is the same or different unsubstituted or substituted 1-valent hydrocarbon group, a is an integer of 10 or more,

(ii) a hydrocarbon compound containing a hydroxyl group represented by the following general formula (2): the amount thereof is 0.01 to 0.5 mol based on 1 mol of the silicon atom-bonded hydroxyl group in the diorganopolysiloxane of component (i),

R¹-OH (2)

in the formula, R¹Is the same or different unsubstituted or substituted 1-valent alkyl with 3 to 20 carbon atoms,

(iii) chloroplatinic acid hexahydrate: the amount of the component (i), (ii) and (iii) is 0.01 to 1% by mass based on the total mass of the components,

(B) inorganic filler: 3 to 300 parts by mass of a stabilizer,

(C) an organosilane having at least 3 hydrolyzable groups in 1 molecule and/or a partial hydrolytic condensate thereof: 1 to 20 parts by mass of a stabilizer,

(D) condensation curing catalyst: 0.01 to 5 parts by mass, and

(E) a silane coupling agent, excluding the (C) component and the (D) component: 0.1 to 5 parts by mass.

Technical Field

The present invention relates to an organopolysiloxane composition that is crosslinked (cured) at room temperature by condensation curing reaction using moisture in the atmosphere to form a silicone rubber elastomer, and more particularly, to a room temperature-curable organopolysiloxane composition that causes little pollution to the surrounding environment when used in stone joints, glass, coated aluminum plates, and the like, has excellent adhesion to various substrates, particularly glass and coated aluminum, and forms a cured product that has little physical change over a long period of time, and a method for producing the same.

Background

Compositions which cure at room temperature (23 ℃. + -. 15 ℃) to form silicone rubbers (elastomer-like elastomers) have been known and widely used in the industry. Among the mechanisms of curing at room temperature, a mechanism of curing by a hydrosilylation reaction, a mechanism of curing by ultraviolet rays, a mechanism of curing by a condensation reaction in which a hydroxyl group and a silicon atom are bonded to a hydrolyzable group, and the like are known. Among them, organopolysiloxane compositions that cure by condensation reaction are cured at room temperature, exhibit the advantage of adhesion to various substrates, and are less likely to suffer from inhibition of curing by impurities that are observed in hydrosilylation reactions and the like, and are therefore suitable for use in applications such as building sealants, civil engineering sealants, and the like.

The cured rubber is advantageous in terms of the following properties of the sealing material for buildings, in terms of low elasticity corresponding to low to medium modulus in the standards established by the japan sealing material industry, in which the type a durometer hardness specified in JIS K6249 of the cured rubber is 10 to 30 and the elongation at break is 500% or more. As a technique for satisfying this, a method of diluting with a silicone oil having no reactive group, a method of adding various plasticizers, and the like are used. However, although these methods have confirmed the corresponding effects with respect to the low elastic modulus, there are cases where the plasticizer migrating around the joint adheres to dirt due to long-term use, or the plasticizer migrates into the interior of the stone material when used in porous materials such as natural stone, causing infiltration contamination, and improvements in these are desired.

Among them, it is difficult to completely eliminate such staining properties, and improvement is achieved to some extent if a composition containing a non-reactive silicone oil as a plasticizer is not blended. However, in this case, there are problems as follows: the cured rubber has a high modulus and insufficient adhesion to metals and various coatings. Therefore, as a countermeasure for obtaining a soft rubber with a composition in which no plasticizer is compounded, the following method is adopted: when a 2-functional crosslinking agent having a chain-extending ability is used in combination with a polyfunctional crosslinking agent, the diorganopolysiloxane is crosslinked while extending its chains in the curing reaction, thereby reducing the crosslinking density after curing. As a representative method, a siloxane having an N, N-dialkylaminoxy group called an aminoxy group type is used as a crosslinking agent, and a silane having an N-alkylacetamido group called an amide type is used as a crosslinking agent. However, these compositions have poor storage stability and, in the coexistence of a compound having an active hydrogen such as an alcohol, have problems that curing is inhibited and the remaining free oil component becomes a contamination source similar to that of a plasticizer.

Therefore, it has been proposed that a rubber having a low crosslinking density be obtained by using a functional group which has been conventionally widely used and has good storage stability without causing curing inhibition (patent document 1: Japanese patent application laid-open No. 63-83167). It is prepared by using RNHCH with chain-increasing ability₂MeSi(OMe)₂And the like. However, it is significantly difficult to economically produce the compound, and it is also difficult to stably obtain a balance with other crosslinking agents. Further, there have been proposed a number of methods of using a diorganopolysiloxane having a hydroxyl group at one end of the molecular chain and a trialkylsiloxy group at the other endMethods (patent documents 2 and 3: Japanese patent application laid-open Nos. 9-151326 and 2004-182942). However, in the case of producing such a diorganopolysiloxane blocked at one end with a silanol group and blocked at the other end with a trialkylsiloxy group, when a general method of equilibrium polymerization of a diorganocyclopolysiloxane using an alkali catalyst or an acid catalyst is employed, removal of the by-product unreactive diorganopolysiloxane is not possible, and therefore bleeding contamination occurs during use of the composition, and stone joints of natural stone materials and the like are contaminated, and the problem has not been solved yet.

Further, the ring-opening polymerization of a cyclic siloxane trimer using lithium trimethylsiloxy as an initiator, and the polymerization in the presence of a silicon pentacomplex using trimethylhydroxysilane or the like as an initiator can be carried out while reducing the amount of a by-produced unreactive diorganopolysiloxane, but is economically disadvantageous because the cost of monomers and catalysts is high.

Further, it has been proposed to reduce the crosslinking density by delaying the curing reaction using a triorganosilanol such as diphenylmethylsilanol (patent document 4: Japanese patent No. 4912746), but it is difficult to maintain the low modulus physical properties for a long period of time.

As described so far, the following room-temperature-curable organopolysiloxane compositions have not been obtained: the silicone rubber composition has less bleeding contamination on the surface and natural stone, can be used as a sealing material to obtain a soft silicone rubber cured product with excellent adhesiveness from a low modulus to a medium modulus, has excellent storage stability, and can maintain low modulus physical properties for a long period of time after curing.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 63-83167

Patent document 2: japanese laid-open patent publication No. 9-151326

Patent document 3: japanese patent laid-open publication No. 2004-182942

Patent document 4: japanese patent No. 4912746

Disclosure of Invention

Problems to be solved by the invention

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a room temperature curable organopolysiloxane composition which forms a silicone rubber cured product that maintains rubber elasticity with a low elastic modulus ranging from low modulus to medium modulus for a long period of time and causes little contamination to natural stone, painted aluminum, and the like, and a method for producing the same.

Means for solving the problems

The present inventors have made extensive studies to achieve the above object, and as a result, have found that: a room-temperature-curable organopolysiloxane composition is produced by preparing in advance a reaction product obtained by mixing and reacting a diorganopolysiloxane represented by the following general formula (1), a hydroxyl group-containing hydrocarbon compound represented by an alcohol compound represented by the following general formula (2), and chloroplatinic acid in a specific ratio with respect to silicon atom-bonded hydroxyl groups (silanol groups) in the diorganopolysiloxane, preferably at 0 ℃ to 50 ℃ for 5 minutes or more, and then uniformly mixing the reaction product with an organosilane having at least 3 hydrolyzable groups in one molecule and/or a partial hydrolysis-condensation product thereof, an inorganic filler, a condensation-curing catalyst, and a silane coupling agent, thereby suppressing by-produced free oil (i.e., a linear diorganopolysiloxane represented by a triorganosiloxy group-terminated at both molecular chain terminals, a hydrocarbon compound represented by a general formula (2), A so-called nonfunctional silicone oil such as a linear and/or branched diorganopolysiloxane having a terminal of the molecular chain blocked with a triorganosiloxy group, or a cyclic diorganopolysiloxane having no functional group in the molecule), and as a cured product of the composition, a low-elasticity silicone rubber cured product corresponding to a low-to-medium modulus is obtained, and further, a low-elasticity cured product (silicone rubber) excellent in adhesion to a material to be adhered, particularly adhesion to various substrates such as aluminum materials surface-treated with a fluororesin, an acrylic resin, or the like, free from contamination of a porous material such as a natural stone material, or the surrounding environment such as a coated aluminum plate, and further, a room-temperature-curable organopolysiloxane composition excellent in storage stability and capable of solving the above-mentioned problems is obtained, and the present invention has been completed.

Namely, the present invention provides the following room temperature-curable organopolysiloxane composition and a method for producing the composition.

1. A room-temperature-curable organopolysiloxane composition comprising:

(A) the reaction products of the following (i), (ii) and (iii): 100 parts by mass of a water-soluble polymer,

(i) a diorganopolysiloxane represented by the following general formula (1),

[ solution 1]

(wherein R is the same or different unsubstituted or substituted 1-valent hydrocarbon group, and a is an integer of 10 or more.)

(ii) A hydrocarbon compound containing a hydroxyl group represented by the following general formula (2): the amount thereof being such that the amount thereof is 0.01 to 0.5 mol relative to 1 mol of the silicon atom-bonded hydroxyl groups in the diorganopolysiloxane of the component (i), and

R¹-OH (2)

(in the formula, R¹The carbon number of the same or different unsubstituted or substituted 1-valent alkyl groups is 3 to 20. )

(iii) Chloroplatinic acid hexahydrate: the amount thereof being 0.01 to 1% by mass of the whole of the component (A),

(B) inorganic filler: 3 to 300 parts by mass of a stabilizer,

(C) an organosilane having at least 3 hydrolyzable groups in 1 molecule and/or a partial hydrolytic condensate thereof: 1 to 20 parts by mass of a stabilizer,

(D) condensation curing catalyst: 0.01 to 5 parts by mass of a stabilizer,

(E) a silane coupling agent, excluding the (C) component and the (D) component: 0.1 to 5 parts by mass.

2. The room-temperature-curable organopolysiloxane composition according to claim 1, wherein the content of the nonfunctional silicone oil in the room-temperature-curable organopolysiloxane composition is 0% by mass or more and less than 10% by mass.

3. The room-temperature-curable organopolysiloxane composition according to 1 or 2, wherein the inorganic filler of component (B) contains fumed silica and/or calcium carbonate.

4. The room-temperature-curable organopolysiloxane composition according to any one of claims 1 to 3, wherein the silane coupling agent of component (E) is an amine-based silane coupling agent having an alkoxysilyl group as a hydrolyzable group.

5. The room-temperature-curable organopolysiloxane composition according to any one of claims 1 to 4, which forms a silicone rubber cured product having a type A durometer hardness of 10 to 30 and an elongation at break of 500% or more as specified in JIS K6249.

6. The room-temperature-curable organopolysiloxane composition according to any one of claims 1 to 5, which forms a silicone rubber cured product having an amount of components extracted into a toluene layer by immersion in toluene for 24 hours of 10 mass% or less.

7. The room-temperature-curable organopolysiloxane composition according to any one of 1 to 6, which is used for a sealing material for buildings.

8. A method for producing a room-temperature-curable organopolysiloxane composition, comprising the steps of: after mixing the following (i), (ii) and (iii) at 0 ℃ to 50 ℃ for 5 minutes or more to produce a reaction product (A), the following (B), (C), (D) and (E) are uniformly mixed with respect to 100 parts by mass of the reaction product (A),

(i) a diorganopolysiloxane represented by the following general formula (1),

[ solution 2]

(wherein R is the same or different unsubstituted or substituted 1-valent hydrocarbon group, and a is an integer of 10 or more.)

(ii) A hydrocarbon compound containing a hydroxyl group represented by the following general formula (2): the amount thereof being such that the amount thereof is 0.01 to 0.5 mol relative to 1 mol of the silicon atom-bonded hydroxyl groups in the diorganopolysiloxane of the component (i), and

R¹-OH (2)

(in the formula, R¹Has 3 to 20 carbon atomsIdentical or different unsubstituted or substituted 1-valent hydrocarbon radicals. )

(iii) Chloroplatinic acid hexahydrate: the amount of the component (i), (ii) and (iii) is 0.01 to 1% by mass based on the total mass of the components,

(B) inorganic filler: 3 to 300 parts by mass of a stabilizer,

(C) an organosilane having at least 3 hydrolyzable groups in 1 molecule and/or a partial hydrolytic condensate thereof: 1 to 20 parts by mass of a stabilizer,

(D) condensation curing catalyst: 0.01 to 5 parts by mass, and

(E) a silane coupling agent, excluding the (C) component and the (D) component: 0.1 to 5 parts by mass.

In the room-temperature-curable organopolysiloxane composition according to the present invention, it is preferable that the content of the nonfunctional silicone oil (i.e., linear and/or branched diorganopolysiloxane that is capped at the molecular chain end with triorganosiloxy groups (siloxy groups in which silicon atoms do not have Si — O — C bonds) and does not participate in condensation curing reaction, or cyclic diorganopolysiloxane that does not contain functional groups in the molecule) in the composition is 0 mass% or more and less than 10 mass%. If the amount of the nonfunctional silicone oil is 10% by mass or more in the composition, bleeding contamination may occur when a silicone rubber cured product obtained by curing the composition is applied to a porous stone material such as granite or the like as a sealing material or the like. The content of the nonfunctional silicone oil in the room-temperature-curable organopolysiloxane composition according to the present invention can be determined by a mass reduction test (toluene extraction test) in which a cured product (silicone rubber) is immersed in toluene and then dried, as described below.

More preferably, the inorganic filler (B) is one selected from the group consisting of untreated calcium carbonate, calcium carbonate treated with a treating agent in an amount of 3% by mass or less with respect to the calcium carbonate, and fumed silica, or a combination of two or more thereof.

ADVANTAGEOUS EFFECTS OF INVENTION

The room-temperature-curable organopolysiloxane composition of the present invention forms a low-modulus cured product (silicone rubber) that causes little contamination with bleeding from porous stone materials such as granite, and exhibits good conformability even when the expansion and contraction of joints are large, and therefore can be suitably used as a sealing material for buildings and the like.

Detailed Description

[ Room temperature-curable organopolysiloxane composition ]

The room-temperature-curable organopolysiloxane composition according to the present invention is described below.

[ (A) component ]

The component (a) contained in the room-temperature-curable organopolysiloxane composition of the present invention is a main agent (base polymer) of the composition of the present invention, and is a reaction product of the following 3 components, (i) a diorganopolysiloxane, (ii) a hydroxyl group-containing hydrocarbon compound, and (iii) chloroplatinic acid hexahydrate, with a part of silanol groups in the component (i) having been subjected to a substitution reaction with the hydroxyl group-containing hydrocarbon compound of the component (ii).

(i) component (i)

(i) The component (A) is a linear diorganopolysiloxane having both ends of the molecular chain represented by the following general formula (1) blocked with silanol groups (silicon atom-bonded hydroxyl groups) (in particular, hydroxydiorganosiloxy groups).

[ solution 3]

(wherein R is the same or different unsubstituted or substituted, preferably halogen atom-substituted, 1-valent hydrocarbon group, and a is an integer of 10 or more.)

In the general formula (1), R independently includes an alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, or a hexyl group, a cycloalkyl group such as a cyclohexyl group, a 1-valent hydrocarbon group having 1 to 6 carbon atoms such as an alkenyl group such as a vinyl group, an allyl group, or an propenyl group, and an aryl group such as a phenyl group, or a 1-valent substituted hydrocarbon group such as a chloromethyl group or a 3, 3, 3-trifluoropropyl group in which a part or all of hydrogen atoms of these groups are substituted with a halogen atom such as F, Cl, or Br, and is preferably a methyl group or a phenyl group, and particularly preferably a methyl group. The R may be the same group or different groups.

as described above, a is an integer of 10 or more, preferably an integer of 10 to 2000, more preferably an integer of 50 to 1200, and further preferably an integer of 100 to 1000, and the viscosity of the diorganopolysiloxane is preferably a number of 100 to 1000000mPa · s, more preferably a number of 500 to 200000mPa · s at 23 ℃. The viscosity is a value measured by a rotational viscometer (for example, BL type, BH type, BS type, cone plate type, rheometer, etc.). In the general formula (1), the value of a indicating the number of repetitions of the diorganosiloxane unit (or the polymerization degree) can be usually determined as the number average molecular weight (or the number average polymerization degree) in terms of polystyrene obtained by Gel Permeation Chromatography (GPC) analysis using toluene or the like as an eluting solvent.

(ii) component (ii)

(ii) The component (a) is a hydrocarbon compound having 1 hydroxyl group in the molecule, represented by an alcohol compound represented by the following general formula (2) or the like, and before being blended in the composition, the component (b) functions as a modulus-lowering agent for performing a substitution reaction with a part of the hydroxyl groups (i.e., silanol groups at both ends of the molecular chain) in the component (i) in the presence of (iii) chloroplatinic acid hexahydrate to produce a reaction product (a) in which a part of the silanol group-containing siloxy group (hydroxydiorganosiloxy group) is substituted with an (organooxy) diorganosiloxy group.

R¹-OH (2)

(in the formula, R¹The carbon number of the same or different unsubstituted or substituted 1-valent alkyl groups is 3 to 20. )

In the above general formula (2), R¹The hydrocarbon group is an unsubstituted or substituted 1-valent hydrocarbon group, preferably a 1-valent hydrocarbon group having 3 to 20 carbon atoms, particularly 6 to 10 carbon atoms, and specific examples thereof include (cyclo) alkyl groups such as propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, cyclohexyl, 2-ethylhexyl, decyl, aryl groups such as phenyl and tolyl, aralkyl groups such as allyl, butenyl, benzyl and 2-phenylethyl, and groups obtained by substituting a part or all of hydrogen atoms bonded to carbon atoms of these groups with halogen atoms such as F, Cl and Br, cyano groups, such as chloromethyl, 3, 3, 3-trifluoropropyl and cyanoethyl, and the R is a group¹Preferably isopropyl group,Butyl, 2-ethylhexyl, phenyl, and 3, 3, 3-trifluoropropyl, and particularly from the viewpoint of ease of production, alkyl is preferred, and isopropyl, butyl, and 2-ethylhexyl are more preferred.

(ii) Component (i) is added in an amount of 0.01 to 0.50 mol, preferably 0.05 to 0.45 mol, and more preferably 0.1 to 0.4 mol, based on 1 mol of the silicon atom-bonded hydroxyl group (silanol group) in the diorganopolysiloxane of component (i) represented by general formula (1). If the amount of the silicone-atom-bonded hydroxyl group (silanol group) in the diorganopolysiloxane of component (i) is less than 0.01 mol, a sufficient modulus-lowering effect cannot be obtained, and it is difficult to obtain a desired cured product having soft rubber elasticity, and if the amount of the silicone-atom-bonded hydroxyl group is more than 0.50 mol, curability and adhesiveness are deteriorated, and at the same time, a free oil component (so-called nonfunctional silicone oil such as a linear and/or branched diorganopolysiloxane having a triorganosiloxy group-blocked molecular chain terminal, represented by a linear diorganopolysiloxane having a triorganosiloxy group-blocked molecular chain at both molecular chain terminals, or a cyclic diorganopolysiloxane having no functional group in the molecule) in the obtained cured product increases, and there is a possibility of significant contamination.

(iii) component (iii)

(iii) The chloroplatinic acid hexahydrate of the component (i) is a component having an action of efficiently causing a substitution reaction between the hydroxyl group-containing hydrocarbon compound of the component (ii) and the silanol group of the component (i) (quantitatively), and is a component which is a feature of the present invention. In the chemical formula, the compound represented by formula (I) can be used as it is₂PtCl₆·6H₂O represents a commercially available product.

(iii) The component (A) is added in an amount of 0.01 to 1% by mass based on the total mass of the components (i.e., the total mass of the components (i), (ii) and (iii)). If the amount is less than 0.01% by mass, the effect of reacting the component (i) with the component (ii) is not sufficiently obtained, and if it exceeds 1% by mass, the cost is not favorable.

[ (B) component ]

The room-temperature-curable organopolysiloxane composition of the present invention contains an inorganic filler as component (B).

Examples of the inorganic filler of component (B) include calcium carbonate, fumed silica, alumina, aluminum hydroxide, talc, glass mesoporous spheres, crystalline silica fine powder, amorphous silica fine powder, silica hydrogel, silica aerogel, diatomaceous earth, calcium silicate, aluminum silicate, titanium oxide, zinc oxide, ferrite, iron oxide, carbon black, graphite, mica, clay, bentonite, and the like. Among them, fumed silica and/or calcium carbonate are preferably contained.

The calcium carbonate is freely selected from calcium carbonate treated with a treating agent selected from fatty acids, resin acids, rosin acids, and/or alkali metal salts, alkaline earth metal salts, fatty acid esters, and quaternary ammonium salts thereof, or untreated calcium carbonate. In addition, as for the fumed silica, it is also possible to freely select either fumed silica treated with the above-mentioned treating agent or untreated fumed silica. Examples of the resin acid used herein include abietic acid, dehydroabietic acid, dextropimaric acid, levopimaric acid, palustric acid, sandaracopimaric acid, and the like. The carboxylic acid other than the resin acid is not particularly limited, but carboxylic acids having 12 or more carbon atoms are preferable, and for example, stearic acid, oleic acid, palmitic acid, lauric acid, and the like can be used. The calcium carbonate treated with the above-mentioned treating agent may be a colloidal calcium carbonate having an average primary particle diameter of 0.1 μm or less, particularly 0.03 to 0.1 μm, and/or a ground calcium carbonate having an average primary particle diameter larger than 0.1 μm, used alone or in combination. The amount of calcium carbonate treated with the treating agent is 3.0% by mass or less, particularly 0.5 to 2.5% by mass, based on calcium carbonate. When the amount of the treatment is more than 3.0 mass%, the adhesiveness of the composition is impaired.

The particle size of the colloidal calcium carbonate is a value measured by an electron microscope method, and the particle size of the ground calcium carbonate is a calculated value obtained from a specific surface area measured and calculated by an air permeation method.

The amount of the inorganic filler of component (B) is 3 to 300 parts by mass, preferably 8 to 200 parts by mass, per 100 parts by mass of component (A). If the amount is less than 3 parts by mass, the desired reinforcing property cannot be obtained. When the amount exceeds 300 parts by mass, kneading at the time of production of the composition is difficult, and the rubber elasticity after curing is hard, so that it is difficult to obtain a composition having the desired rubber elasticity.

In the composition of the present invention, other fillers may be used in combination as needed, and the amount of the filler added may be a usual amount within a range not impairing the effects of the present invention.

[ (C) ingredient ]

The room-temperature-curable organopolysiloxane composition of the present invention contains, as component (C), an organosilane having at least 3 hydrolyzable groups in 1 molecule (but not including component (D)) and/or a partial hydrolysis-condensate thereof (i.e., an organosiloxane oligomer having at least 2, preferably 3 or more residual hydrolyzable groups in the molecule, which is produced by partially hydrolyzing the hydrolyzable organosilane). The component (C) functions as a storage stabilizer and a crosslinking agent in the room-temperature-curable organopolysiloxane composition of the present invention.

Examples of the hydrolyzable group of the organosilane compound as component (C) and the partial hydrolysis condensate thereof include ketoximino groups (e.g., dimethylketoximino group, methylethylketoximino group, and methylisobutylketonximino group), alkoxy groups (e.g., methoxy group and ethoxy group), acyloxy groups (e.g., acetoxy group), and alkenoxy groups (e.g., isopropenoxy group). In component (C), examples of the substituent (1-valent hydrocarbon group) other than the hydrolyzable group bonded to the silicon atom include unsubstituted 1-valent hydrocarbon groups such as alkyl groups including methyl, ethyl, and propyl, aryl groups including phenyl, and alkenyl groups including vinyl and allyl. (C) The component (a) is clearly distinguished from the condensation curing catalyst of the component (D) and the silane coupling agent of the component (E) described later in that the component (a) does not contain a monovalent hydrocarbon group substituted with a functional group containing a heteroatom such as a nitrogen atom, an oxygen atom, a sulfur atom or the like in the molecule.

Specific examples of the component (C) include ketoximinosilanes such as tetrakis (methylethylketoximo) silane, methyltris (dimethylketoximo) silane, methyltris (methylethylketoximo) silane (also known as methyltris 2-butanone oxime silane), ethyltris (methylethylketoximo) silane, methyltris (methylisobutylketonximo) silane, vinyltris (methylethylketoximo) silane (also known as vinyltris 2-butanone oxime silane), alkoxysilanes such as methyltrimethoxysilane, vinyltrimethoxysilane, phenyltrimethoxysilane, vinyltriethoxysilane, acetoxysilanes such as methyltriacetoxysilane, vinyltriacetoxysilane, methyltriisopropenoxysilane, phenyltriisopropenoxysilane, etc, And partial hydrolysis condensates of these silanes. These may be used alone or in combination.

The amount of component (C) is 1 to 20 parts by mass, preferably 5 to 15 parts by mass, per 100 parts by mass of component (A). If the amount is less than 1 part by mass, sufficient crosslinking cannot be obtained, and it is difficult to obtain a cured product having a desired rubber elasticity, and if it exceeds 20 parts by mass, the curing rate at a deep part which is not in contact with air becomes slow, and the rubber elasticity after curing becomes hard, which is disadvantageous in terms of price.

[ (D) component ]

The room-temperature-curable organopolysiloxane composition of the present invention contains a condensation curing catalyst as component (D) in order to accelerate curing of the composition.

The condensation curing catalyst of the component (D) is not particularly limited, and examples thereof include those generally used as a curing accelerator in the composition. Examples of the inorganic filler include metal Lewis acids such as dibutyltin dimethoxide, dibutyltin diacetate, dibutyltin dioctoate, dibutyltin dilaurate, dibutyltin bis (acetylacetonate), dibutyltin bis (benzyl maleate), dimethyltin dimethoxide, dimethyltin diacetate, dioctyltin dioctoate, dioctyltin dilaurate, tin dioctoate and tin dilaurate, organic titanium compounds such as tetraisopropyl titanate, tetra-n-butyl titanate, tetra-t-butyl titanate, tetra-n-propyl titanate, tetra-2-ethylhexyl titanate, di-isopropyl di-t-butyl titanate, titanium dimethoxybisacetoacetate, titanium diisopropoxybis-ethyl diacetate, titanium di-t-butoxybisacetoacetate and titanium di-t-butoxybisacetoacetate, amine compounds such as butylamine and octylamine, and salts thereof, tetramethylguanidinopropyl trimethoxysilane, metal Lewis acids such as titanium compounds such as, 1 or 2 or more of hydrolyzable silanes containing a guanidino group and siloxanes such as tetramethylguanidinopropylmethyldimethoxysilane and tetramethylguanidinopropyltris (trimethylsiloxy) silane are used in combination.

The amount of the condensation curing catalyst of component (D) is 10 parts by mass or less, particularly 0.01 to 5 parts by mass, per 100 parts by mass of component (A). If the amount of the condensation curing catalyst is more than 10 parts by mass, cracks and breakage after the durability test are likely to occur. If the amount is small, the time until curing becomes long, which is not preferable in practice.

[ (E) ingredient ]

The room-temperature-curable organopolysiloxane composition of the present invention contains, as component (E), a silane coupling agent (excluding component (C) and component (D), more specifically, a so-called carbon-functional hydrolyzable silane or carbon-functional silane having, in the molecule, a 1-valent hydrocarbon group substituted with a functional group containing a heteroatom such as a nitrogen atom, an oxygen atom, or a sulfur atom (excluding a guanidine group) and a hydrolyzable group bonded to a silicon atom) in order to improve the adhesiveness of a cured product.

The silane coupling agent as the component (E) is preferably an amine-based silane coupling agent having an alkoxysilyl group as a hydrolyzable group, and examples thereof include N- (2-aminoethyl) 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and 3- (N-aminomethylbenzylamino) propyltrimethoxysilane.

The amount of the silane coupling agent of component (E) is 0.1 to 5 parts by mass, preferably 0.2 to 5 parts by mass, per 100 parts by mass of component (A). If the amount is less than 0.1 part by mass, sufficient adhesiveness is not obtained, and if it exceeds 5 parts by mass, the price becomes unfavorable.

In addition to the above components, various compounding agents such as pigments, dyes, tackifiers, thixotropy enhancers, preservatives, flame retardants, mildewcides and the like may be added to the room-temperature-curable organopolysiloxane composition of the present invention as necessary. The amount of these optional components added can be set to a general amount within a range not to impair the effects of the present invention.

As described above, the room temperature-curable organopolysiloxane composition of the present invention is stored in the absence of moisture, is exposed to air when it is opened or the like during use, reacts with moisture in the air, and cures at room temperature to be a low-to medium-modulus silicone rubber elastomer. The room-temperature-curable organopolysiloxane composition of the present invention preferably forms a silicone rubber cured product having a type a durometer hardness of 10 to 30 and an elongation at break of 500% or more, as specified in JIS K6249, and further preferably forms a silicone rubber cured product having an amount of components extracted by a toluene layer by immersion in toluene for 24 hours of 10 mass% or less. Further, the composition hardly causes a curing mechanism by a hydrosilylation reaction, curing inhibition observed in an aminoxy type or an amide type, and the like, and when used in a porous material such as a natural stone, bleeding contamination hardly occurs, and the composition exhibits adhesiveness to various substrates, particularly a coated aluminum material. Therefore, it is useful for adhesives, coating materials, and particularly, sealing materials for buildings.

[ method for producing Room temperature-curable organopolysiloxane composition ]

The method for producing a room-temperature-curable organopolysiloxane composition according to the present invention comprises the steps of: mixing the component (i) (the diorganopolysiloxane of formula (1)), the component (ii) (the hydroxyl group-containing hydrocarbon compound of formula (2) in an amount of 0.01 to 0.5 mol relative to 1 mol of hydroxyl groups in the diorganopolysiloxane of formula (1) of the component (i)), and the component (iii) (the chloroplatinic acid hexahydrate in an amount of 0.01 to 1 mass% relative to the total mass of the components (i), (ii), and (iii)) at 0 ℃ to 50 ℃ for 5 minutes or more to prepare a reaction product (a), and then, the component (B) is an inorganic filler, relative to 100 parts by mass of the reaction product (a): 3 to 300 parts by mass of (C) an organosilane having at least 3 hydrolyzable groups in 1 molecule and/or a partial hydrolysis-condensation product thereof: 1-20 parts by mass of the condensation curing catalyst (D): 0.01 to 5 parts by mass of the silane coupling agent (E) (excluding the component (C) and the component (D)): 0.1 to 5 parts by mass of a solvent.

In the present invention, a diorganopolysiloxane of component (i) represented by formula (1), a hydroxyl group-containing hydrocarbon compound of component (ii), and chloroplatinic acid hexahydrate of component (iii) are mixed at 0 ℃ to 50 ℃ for 5 minutes or more to cause a substitution reaction between a portion of silanol groups in component (i) and the hydroxyl group-containing hydrocarbon compound of component (ii), thereby obtaining a reaction product (a).

In the method for producing the reaction product (A), the temperature at which the components (i), (ii) and (iii) are mixed and reacted is 0 ℃ to 50 ℃, preferably 10 ℃ to 40 ℃. If the temperature is lower than 0 ℃, the modulus-decreasing effect is insufficient, and if it exceeds 50 ℃, the amount of volatilization of the component (ii) increases, and it may be difficult to obtain the target physical properties.

The mixing reaction time is 5 minutes or more, preferably 10 minutes or more, to obtain a desired effect. The long time is not particularly limited, but the long time mixing causes no cost advantage, and when the time is left until the next step, it is preferable to complete the mixing in about 3 hours and use the product stored in a sealed state.

The reaction product (a) obtained above and the other components (B) to (E) can be mixed by a conventional method (preferably under reduced pressure) to produce the room-temperature-curable organopolysiloxane composition of the present invention.

Examples

The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples. The viscosity is a measured value obtained by a rotational viscometer.

[ example 1]

To 100 parts by mass of dimethylpolysiloxane blocked with hydroxyl groups at both ends of the molecular chain and having a viscosity of 50000 mPas at 23 ℃ (in formula (1), a is 874, and the content of hydroxyl groups bonded to silicon atoms is 0.00305 moles), 0.017 part by mass of chloroplatinic acid hexahydrate and 0.15 part by mass of 2-ethylhexanol (the amount is 0.38 moles based on 1 mole of hydroxyl groups (silanol groups) bonded to silicon atoms in the dimethylpolysiloxane at the end of the hydroxyl groups) were added, and the mixture was mixed at 23 ℃ for 10 minutes until it became homogeneous to prepare reaction product 1.

Next, for reaction product 1: to 100 parts by mass of colloidal Calcium carbonate (trade name "OKYUMWHA BK-04", Dongho Calcium Co., Ltd., average primary particle diameter 0.04 μm)70 parts by mass, methyl tris 2-butanone oxime silane 8 parts by mass, vinyl tris 2-butanone oxime silane 2 parts by mass, N- (2-aminoethyl) 3-aminopropyltrimethoxysilane 1 part by mass, and dioctyltin dilaurate 0.05 part by mass were added, and the mixture was mixed under reduced pressure until homogeneous, to obtain a room temperature curable organopolysiloxane composition.

Comparative example 1

A room-temperature-curable organopolysiloxane composition was obtained in the same manner as in example 1, except that 0.17 part by mass of 1, 3-divinyltetramethyldisiloxane complex containing platinum was added in place of 0.017 part by mass of chloroplatinic acid hexahydrate.

Comparative example 2

A room-temperature-curable organopolysiloxane composition was obtained in the same manner as in example 1, except that reaction product 1 was not prepared in advance, and 100 parts by mass of dimethylpolysiloxane blocked with hydroxyl groups at both ends of the molecular chain and having a viscosity of 50000 mPas at 23 ℃ was used in place of reaction product 1.

Comparative example 3

A room-temperature-curable organopolysiloxane composition was obtained in the same manner as in example 1, except that 2-ethylhexanol was not added.

Comparative example 4

A room-temperature-curable organopolysiloxane composition was obtained in the same manner as in example 1, except that in example 1, 100 parts by mass of dimethylpolysiloxane blocked at both ends of the molecular chain with a viscosity of 50000mPa · s at 23 ℃ (in formula (1), a is 874, and the content of silicon-bonded hydroxyl groups is 0.00305 moles) and 0.15 part by mass of 2-ethylhexanol (0.38 moles per 1 mole of silicon-bonded hydroxyl groups (silanol groups) in the hydroxyl-terminal dimethylpolysiloxane) were mixed, and 0.017 part by mass of chloroplatinic acid hexahydrate was finally added instead of reaction product 1.

Comparative example 5

A room-temperature-curable organopolysiloxane composition was obtained in the same manner as in example 1, except that the amount of 2-ethylhexanol added was changed to 0.20 parts by mass (0.51 moles per 1 mole of the silicon atom-bonded hydroxyl groups (silanol groups) in the hydroxyl-terminated dimethylpolysiloxane).

[ evaluation method ]

The room-temperature-curable organopolysiloxane composition obtained was evaluated as follows.

(1) Physical Properties (type A durometer hardness, tensile Strength, elongation at Break)

The compositions prepared in the above examples and comparative examples were cast into a 2mm mold and aged at 23 ℃ and 50% RH for 7 days to obtain a rubber sheet having a thickness of 2 mm. The physical properties (type a durometer hardness, tensile strength, elongation at break) of the obtained rubber sheet (cured product of room temperature curable organopolysiloxane composition) were measured in accordance with "test method for cured silicone rubber" (hardness test, tensile test) specified in JIS K6249.

(2) ASTM C719 grade 50 flex fatigue durability test

To evaluate the resistance to movement at the sealed seam, a flex fatigue durability test of ± 50% according to ASTM standard C719 was performed. In detail, the test was carried out as follows.

(sample preparation)

The measurement was carried out using a supporting substrate (material: float glass, size: 1 inch in length, 3 inches in width, and 1/4 inches in thickness) and measuring n as 3.

After the primer for the supporting substrate was applied, the coating was applied with a room temperature curable organopolysiloxane composition, cured and aged (7 days at 23 ℃ and 50% RH) (joint width: 1/2 inches).

After a week of 70 ℃ and 50% compression, the test was transferred to the cycle test.

(cycle test)

The test was performed at room temperature for 10 cycles with 50% elongation and 50% compression as 1 cycle (speed of seam movement: 1/8 (in/h)).

Next, 10 cycles of heat cycling test (50% compression at 70 ℃ followed by 50% elongation at-26 ℃) were performed.

After the test, the samples were confirmed, and the area of peeling or cohesive failure was 50% or less of the total area (n: 3 total area) of the samples and was regarded as pass (o), and the other areas were regarded as fail (x).

(3) Amount of extracted toluene

The contents of the linear and/or branched diorganopolysiloxane capped at the molecular chain end with a triorganosiloxy group and the cyclic diorganopolysiloxane having no functional group in the composition were determined by the following mass reduction test (toluene extraction test) as an index of the amount of the free oil component in the composition. That is, the toluene extraction amount was calculated from the difference in mass of the cured product before and after immersion as shown in the following equation, by immersing 2g of the cured product obtained by aging and curing for 7 days at 23 ℃ and 50% RH in 100g of toluene for 24 hours and then drying the same in an atmosphere at 23 ℃ and 50% RH for 24 hours.

(amount of toluene extracted (% by mass)) of { (amount of cured material before toluene impregnation) - (amount of cured material after toluene impregnation) }/(amount of cured material before toluene impregnation) × 100

When the toluene extraction amount is 10 mass% or less, it can be expected that the bleeding contamination is small when the composition is used for a porous material such as a natural stone material, and therefore the composition is judged to be good.

(4) Bleeding contamination

The following evaluation was performed as the bleeding contamination property.

A joint having a width of 10mm and a depth of 10mm and a width of 50mm was formed between 2 sheets of white granite having a thickness of 10mm, a length of 50mm and a width of 50mm, the joint was filled with an uncured room temperature-curable organopolysiloxane composition, the surface of the joint was smoothly finished with a spatula, and the resultant was aged at 23 ℃ for 2 weeks to obtain a test piece for confirming contamination. The test piece was exposed to the outside for 3 months, and the surface of the white granite was visually observed, and the case where the exudation contamination was recognized as a wet pattern and the range of 1mm or more was recognized from the joint was judged as poor (x), and the case where the contamination was less than 1mm from the joint was judged as good (good).

The above results are shown in table 1.

[ Table 1]

As is clear from the above, the room temperature-curable organopolysiloxane composition of the present invention, after curing, becomes a silicone rubber cured product with low hardness and elongation, and can be used in joints with large movements, and furthermore, the amount of free oil component extracted with toluene is small, so that even when used in joints of porous natural stone or the like, less permeation contamination can be expected over a long period of time.