JP2023086691A - Method for producing room temperature curable organopolysiloxane composition and room temperature curable organopolysiloxane composition - Google Patents

Abstract

To provide a method for producing a room temperature curable organopolysiloxane composition having excellent storage stability in a sealed package form and excellent discoloration resistance of a cured product and to provide the room temperature curable organopolysiloxane composition.SOLUTION: There is provided a method for producing a room temperature curable organopolysiloxane composition which comprises: [I]: a step of uniformly mixing a specific amount of (A-1) an organopolysiloxane having a specific viscosity in which both ends of the molecular chain are sealed with a hydroxysilyl group, (A-2) a hydrolyzable organosilane compound and/or a partially hydrolyzed condensate thereof and (A-3) an amino-functional silane coupling agent having two amino groups in one molecule and containing no aromatic ring in the molecule and/or a partially hydrolyzed condensate thereof at room temperature, followed by subjecting the mixture to standing reaction in a moisture protected environment at room temperature for 6 hours or more to obtain a reaction product mixture (A); and [II] a step of blending the reaction product mixture (A), a curing catalyst (B), aerosol silica (C) and if necessary, a specific amount of the component (A-2), followed by uniformly mixing.SELECTED DRAWING: None

Description

The present invention cures at room temperature (5° C. or more and less than 40° C., particularly 23° C.±15° C.) with moisture (moisture) in the atmosphere to give a silicone rubber cured product (silicone elastomer elastic body). The present invention relates to a method for producing a room-temperature-curable organopolysiloxane composition having excellent storage stability in a packaged form, and to the room-temperature-curable organopolysiloxane composition.

Conventionally, among organopolysiloxane compositions that cure at room temperature to form a rubber-like elastic body, so-called one-component (one-liquid) room-temperature curing, in which the curing reaction proceeds upon contact with moisture in the air, Just before using the organopolysiloxane composition, the user mixes the base composition (a mixture containing base polymer, filler, curing catalyst, etc.) and the curing agent composition (a mixture containing a cross-linking agent, etc.) just before use. ), etc. according to the compounding ratio, there is no troublesome mixing, and there is no mistake in compounding. Because of its excellent adhesion to adherends, it is widely used as an elastic adhesive and coating material in the electrical and electronic industries, and as a sealing material for construction and civil engineering. In addition, since the most widely used organopolysiloxane composition in Japan uses optically transparent fumed silica as a filler, it has a translucent milky white appearance before and after curing. and is preferred for sealing applications around glass. In addition, this translucent translucent milky organopolysiloxane composition is known to be a composition with good productivity for manufacturers because it can be easily colored to a desired color by blending a small amount of pigment. there is

Such one-component room-temperature-curable organopolysiloxane compositions are classified into condensation-curing types in terms of reaction mechanism, and further classified according to the compounds released from the composition upon contact with moisture in the air. Typical examples include organopolysiloxane compositions of deacetic acid type, deoxime type, deamidation type, dehydroxylamine type, deacetone type, dealcoholization type and the like. In the deacetic acid type, acetic acid is released as the curing reaction progresses, so the strong odor of acetic acid is often a problem, and since it corrodes metal, its applications are limited. used only for the purposes of The deoxime type is easy to manufacture and has less odor than the deacetic acid type. Since a composition having adhesiveness can be obtained, it is most widely used for business use and general consumer use in Japan and is preferably used. However, in recent years, concerns about the carcinogenicity of methylethylketoxime, which is an oxime compound that is generated and released during curing, have increased, and the European CLP plans to move the carcinogenicity category of methylethylketoxime to Category 1b in March 2022. have decided. Although it can be used if measures are taken with consideration for safety, it is not used for professional use by specialized workers, but when general consumers such as do-it-yourselfers obtain it and use it casually, it is troublesome. Observance of the items is considered difficult. A deoximation type that cures by generating methyl isobutyl ketoxime instead of methyl ethyl ketoxime has also been proposed as an alternative, but it has a strong odor and requires the installation of local exhaust equipment at the place of use. Amidosilanes and aminoxysilanes, which are used as cross-linking agents for the deamidated and dehydroxylated types, and isopropenoxysilanes, which are used as cross-linkers for the deacetone type, are expensive and have good properties for specific applications. However, it is still too expensive for general consumers to use it as a general-purpose product, and it has not spread.

On the other hand, the dealcoholized type organopolysiloxane composition, which cures by releasing alcohol during curing, has little odor, does not corrode metals such as copper and iron, and is self-retaining by adding a silane coupling agent. A curing type that is easy for general consumers to use, with features such as the ability to obtain a composition with excellent adhesiveness (adhesiveness after curing to various substrates when no primer is used) and excellent adhesion durability. can be said.

However, one-component, dealcoholized organopolysiloxane compositions have the above-described excellent properties for a short period of time after production, but depending on the formulation, the properties immediately after production may be obtained over time during storage. There was a defect in storage stability, such as disappearance. In addition, after storage in a high-temperature environment exceeding 50°C, which often occurs, such as being stored under direct sunlight at the site of use or being stored in a container during transportation, the product will remain even after relatively short storage. In addition to failing to obtain the properties immediately after production, there were problems such as poor curing.

One-component, dealcoholized organopolysiloxane compositions have been proposed for a long time. Compositions comprising siloxanes, alkoxysilanes and titanium compounds are mentioned. Japanese Patent Application Laid-Open No. 55-43119 (Patent Document 2) proposes a composition comprising an organopolysiloxane having terminal alkoxysiloxy groups, an alkoxysilane and an alkoxytitanium. However, when these compositions are blended with calcium carbonate to impart good physical properties to the sealant, storage stability is not obtained, and the desired properties are not obtained when the compositions are stored for a long period of time. was not obtained, and the composition did not cure when stored in a high-temperature environment exceeding 50°C. Furthermore, Japanese Patent Publication No. 7-39547 (Patent Document 3) proposes a composition having excellent storage stability in a sealed state. The use of a terminally modified base polymer is essential, and the preparation of this polymer poses problems such as high industrial costs. The present inventors proposed in Japanese Patent No. 4775600 (Patent Document 4) that the storage stability can be improved by blending a fatty acid ester of a polyhydric alcohol. However, when this technique was applied to an organopolysiloxane composition containing fumed silica as a filler, there was a problem that cloudiness occurred and it was not possible to obtain an organopolysiloxane composition with a translucent milky white appearance.

In addition, in order to obtain a dealcoholized organopolysiloxane composition, an organopolysiloxane whose terminal functional group is a silanol group is used as the base polymer, and an organopolysiloxane whose terminal functional group is a silanol group is used as the base polymer. As a raw material, end-blocking may be performed with a silane compound having an alkoxy group during the manufacturing process, but in order to obtain ease of manufacture and storage stability, organopolysiloxane that has been end-blocked with alkoxysilyl groups in advance is used as the base polymer. It is preferred to use However, it has the drawback that the catalyst for obtaining the organopolysiloxane terminal-blocked with alkoxysilyl groups is expensive, and that it takes a long time to remove the catalyst, resulting in high costs. Therefore, as a method for terminal blocking of silanol groups during the production process, it is generally known to incorporate a basic silane compound such as an amino group-containing silane as a terminal blocking catalyst, and Japanese Patent No. 5888112 (Patent Document 5) Japanese Patent No. 6252466 (Patent Document 6) exemplifies the use of a basic silane compound having a guanidine group or a phenylmethanamine group as a terminal blocking catalyst. However, since the basic silane compound used as the terminal blocking catalyst is special, it may still be economically disadvantageous. However, it has been difficult to obtain a general-purpose room-temperature-curable organopolysiloxane composition that is used by general consumers at low cost.

Japanese Patent Publication No. 39-27643 JP-A-55-43119 Japanese Patent Publication No. 7-39547 Japanese Patent No. 4775600 Japanese Patent No. 6252466 Japanese Patent No. 5888112

An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a dealcoholized room temperature curable organopolysiloxane composition that cures at room temperature with atmospheric moisture to give a silicone rubber cured product, especially a sealed A method for producing a room-temperature-curable organopolysiloxane composition, which is excellent in storage stability in a packaged form and excellent in resistance to discoloration of the cured product, and which can be inexpensively produced without making the composition cloudy, and the room-temperature-curable organopolysiloxane composition. An object of the present invention is to provide a curable organopolysiloxane composition.

（式中、Ｒ¹は独立に炭素数１～１０の非置換又は置換の一価炭化水素基であり、ｍは１０以上の整数である。）
で示される分子鎖両末端がヒドロキシシリル基で封鎖された２３℃における粘度が２０～１，０００，０００ｍＰａ・ｓであるオルガノポリシロキサン：１００質量部、
（Ａ－２）下記一般式（２）

（式中、Ｒ²は炭素数１～１０の非置換又はハロゲン置換一価炭化水素基であり、Ｒ³は独立に炭素数１～１０の非置換の一価炭化水素基であり、ａは３又は４である。）
で示される加水分解性オルガノシラン化合物及び／又はその部分加水分解縮合物：０．２～２０質量部、及び
（Ａ－３）下記一般式（３）

（式中、Ｒ⁴は炭素数２～１０の脂肪族二価炭化水素基であり、Ｒ⁵は炭素数１～１０の脂肪族二価炭化水素基であり、Ｒ⁶及びＲ⁷はそれぞれ独立に炭素数１～１０の非置換又はハロゲン置換一価炭化水素基であり、ｂは２又は３である。）
で示されるシランカップリング剤及び／又はその部分加水分解縮合物：０．１～２０質量部
を室温（５℃以上４０℃未満）で均一に混合した後、室温で湿気遮断環境下に６時間以上静置反応させて反応生成混合物（Ａ）を得る工程、及び
［ＩＩ］：
上記反応生成混合物（Ａ）に、
上記（Ａ－２）成分：０～１８質量部（但し、工程［Ｉ］と工程［ＩＩ］の合計で（Ａ－１）成分１００質量部に対して０．２～２０質量部）、
（Ｂ）硬化触媒：０．００１～２０質量部、及び
（Ｃ）煙霧質シリカ：５～３００質量部
を配合して均一に混合する工程
を含む室温硬化性オルガノポリシロキサン組成物の製造方法により得られた室温硬化性オルガノポリシロキサン組成物が、白濁することなく安価に製造可能であり、密封された包装形態での貯蔵安定性に優れ、大気中の湿気により室温で硬化して、耐変色性に優れたシリコーンゴム硬化物を与えることを見出し、本発明をなすに至った。 The present inventors have conducted intensive studies to achieve the above object, and as a result,
[I]:
(A-1) the following general formula (1)

(In the formula, R ¹ is independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and m is an integer of 10 or more.)
100 parts by mass of an organopolysiloxane having a viscosity of 20 to 1,000,000 mPa s at 23 ° C. and having both ends of the molecular chain blocked with hydroxysilyl groups,
(A-2) the following general formula (2)

(wherein R ² is an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, R ³ is independently an unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and a is 3 or 4.)
A hydrolyzable organosilane compound represented by and/or a partial hydrolytic condensate thereof: 0.2 to 20 parts by mass, and (A-3) the following general formula (3)

(wherein R ⁴ is an aliphatic divalent hydrocarbon group having 2 to 10 carbon atoms, R ⁵ is an aliphatic divalent hydrocarbon group having 1 to 10 carbon atoms, and R ⁶ and R ⁷ are each independently is an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and b is 2 or 3.)
A silane coupling agent represented by and / or a partial hydrolytic condensate thereof: 0.1 to 20 parts by mass are uniformly mixed at room temperature (5 ° C. or more and less than 40 ° C.), and then at room temperature in a moisture-proof environment for 6 hours. [II]:
In the reaction product mixture (A),
Component (A-2): 0 to 18 parts by mass (however, the total of step [I] and step [II] is 0.2 to 20 parts by mass relative to 100 parts by mass of component (A-1)),
(B) curing catalyst: 0.001 to 20 parts by mass, and (C) fumed silica: 5 to 300 parts by mass, by a method for producing a room temperature curable organopolysiloxane composition comprising a step of blending and uniformly mixing The obtained room-temperature-curable organopolysiloxane composition can be produced inexpensively without clouding, has excellent storage stability in a sealed package, cures at room temperature with atmospheric moisture, and is resistant to discoloration. The inventors have found that a cured silicone rubber having excellent properties can be obtained, and have completed the present invention.

（式中、Ｒ¹は独立に炭素数１～１０の非置換又は置換の一価炭化水素基であり、ｍは１０以上の整数である。）
で示される分子鎖両末端がヒドロキシシリル基で封鎖された２３℃における粘度が２０～１，０００，０００ｍＰａ・ｓであるオルガノポリシロキサン：１００質量部、
（Ａ－２）下記一般式（２）

（式中、Ｒ²は炭素数１～１０の非置換又はハロゲン置換一価炭化水素基であり、Ｒ³は独立に炭素数１～１０の非置換の一価炭化水素基であり、ａは３又は４である。）
で示される加水分解性オルガノシラン化合物及び／又はその部分加水分解縮合物：０．２～２０質量部、及び
（Ａ－３）下記一般式（３）

（式中、Ｒ⁴は炭素数２～１０の脂肪族二価炭化水素基であり、Ｒ⁵は炭素数１～１０の脂肪族二価炭化水素基であり、Ｒ⁶及びＲ⁷はそれぞれ独立に炭素数１～１０の非置換又はハロゲン置換一価炭化水素基であり、ｂは２又は３である。）
で示されるシランカップリング剤及び／又はその部分加水分解縮合物：０．１～２０質量部
を室温（５℃以上４０℃未満）で均一に混合した後、室温で湿気遮断環境下に６時間以上静置反応させて反応生成混合物（Ａ）を得る工程、及び
［ＩＩ］：
上記反応生成混合物（Ａ）に、
上記（Ａ－２）成分：０～１８質量部（但し、工程［Ｉ］と工程［ＩＩ］の合計で（Ａ－１）成分１００質量部に対して０．２～２０質量部）、
（Ｂ）硬化触媒：０．００１～２０質量部、及び
（Ｃ）煙霧質シリカ：５～３００質量部
を配合して均一に混合する工程
を含む室温硬化性オルガノポリシロキサン組成物の製造方法。
［２］
工程［Ｉ］及び／又は［ＩＩ］において、（Ａ－１）成分１００質量部に対して、更に（Ｄ）シリル化剤を０．１～１０質量部配合するものである［１］に記載の室温硬化性オルガノポリシロキサン組成物の製造方法。
［３］
（Ａ－１）下記一般式（１）

（式中、Ｒ¹は独立に炭素数１～１０の非置換又は置換の一価炭化水素基であり、ｍは１０以上の整数である。）
で示される分子鎖両末端がヒドロキシシリル基で封鎖された２３℃における粘度が２０～１，０００，０００ｍＰａ・ｓであるオルガノポリシロキサン：１００質量部、
（Ａ－２）下記一般式（２）

（式中、Ｒ²は炭素数１～１０の非置換又はハロゲン置換一価炭化水素基であり、Ｒ³は独立に炭素数１～１０の非置換の一価炭化水素基であり、ａは３又は４である。）
で示される加水分解性オルガノシラン化合物及び／又はその部分加水分解縮合物：０．２～２０質量部、及び
（Ａ－３）下記一般式（３）

（式中、Ｒ⁴は炭素数２～１０の脂肪族二価炭化水素基であり、Ｒ⁵は炭素数１～１０の脂肪族二価炭化水素基であり、Ｒ⁶及びＲ⁷はそれぞれ独立に炭素数１～１０の非置換又はハロゲン置換一価炭化水素基であり、ｂは２又は３である。）
で示されるシランカップリング剤及び／又はその部分加水分解縮合物：０．１～２０質量部
の上記の配合比率での混合物を室温で湿気遮断環境下に６時間以上静置反応させてなる反応生成混合物（Ａ）、
上記（Ａ－２）成分：０～１８質量部（但し、組成物全体で（Ａ－１）成分１００質量部に対して０．２～２０質量部）、
（Ｂ）硬化触媒：０．００１～２０質量部、及び
（Ｃ）煙霧質シリカ：５～３００質量部
を含む室温硬化性オルガノポリシロキサン組成物。
［４］
更に、（Ｄ）シリル化剤を（Ａ－１）成分１００質量部に対して０．１～１０質量部含むものである［３］に記載の室温硬化性オルガノポリシロキサン組成物。
［５］
芳香環を含むシランカップリング剤を含まないものである［３］又は［４］に記載の室温硬化性オルガノポリシロキサン組成物。
［６］
ＪＩＳ Ａ １４３９に準拠した垂直スランプ試験における測定値が０～３ｍｍの非流動性のペーストである［３］～［５］のいずれかに記載の室温硬化性オルガノポリシロキサン組成物。 Accordingly, the present invention provides the following room-temperature-curable organopolysiloxane composition manufacturing method and room-temperature-curable organopolysiloxane composition.
[1]
[I]:
(A-1) the following general formula (1)

(In the formula, R ¹ is independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and m is an integer of 10 or more.)
100 parts by mass of an organopolysiloxane having a viscosity of 20 to 1,000,000 mPa s at 23 ° C. and having both ends of the molecular chain blocked with hydroxysilyl groups,
(A-2) the following general formula (2)

(wherein R ² is an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, R ³ is independently an unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and a is 3 or 4.)
A hydrolyzable organosilane compound represented by and/or a partial hydrolytic condensate thereof: 0.2 to 20 parts by mass, and (A-3) the following general formula (3)

(wherein R ⁴ is an aliphatic divalent hydrocarbon group having 2 to 10 carbon atoms, R ⁵ is an aliphatic divalent hydrocarbon group having 1 to 10 carbon atoms, and R ⁶ and R ⁷ are each independently is an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and b is 2 or 3.)
A silane coupling agent represented by and / or a partial hydrolytic condensate thereof: 0.1 to 20 parts by mass are uniformly mixed at room temperature (5 ° C. or more and less than 40 ° C.), and then at room temperature in a moisture-proof environment for 6 hours. [II]:
In the reaction product mixture (A),
Component (A-2): 0 to 18 parts by mass (however, the total of step [I] and step [II] is 0.2 to 20 parts by mass relative to 100 parts by mass of component (A-1)),
(B) curing catalyst: 0.001 to 20 parts by mass; and (C) fumed silica: 5 to 300 parts by mass.
[2]
According to [1], in steps [I] and/or [II], 0.1 to 10 parts by mass of (D) a silylating agent is blended with 100 parts by mass of component (A-1). A method for producing a room temperature curable organopolysiloxane composition.
[3]
(A-1) the following general formula (1)

(In the formula, R ¹ is independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and m is an integer of 10 or more.)
100 parts by mass of an organopolysiloxane having a viscosity of 20 to 1,000,000 mPa s at 23 ° C. and having both ends of the molecular chain blocked with hydroxysilyl groups,
(A-2) the following general formula (2)

(wherein R ² is an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, R ³ is independently an unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and a is 3 or 4.)
A hydrolyzable organosilane compound represented by and/or a partial hydrolytic condensate thereof: 0.2 to 20 parts by mass, and (A-3) the following general formula (3)

(wherein R ⁴ is an aliphatic divalent hydrocarbon group having 2 to 10 carbon atoms, R ⁵ is an aliphatic divalent hydrocarbon group having 1 to 10 carbon atoms, and R ⁶ and R ⁷ are each independently is an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and b is 2 or 3.)
The silane coupling agent represented by and/or its partial hydrolysis condensate: 0.1 to 20 parts by mass of the mixture at the above mixing ratio is allowed to stand at room temperature for 6 hours or more in a moisture-proof environment to react. product mixture (A),
Component (A-2): 0 to 18 parts by mass (0.2 to 20 parts by mass based on 100 parts by mass of component (A-1) in the entire composition),
A room temperature curable organopolysiloxane composition comprising (B) curing catalyst: 0.001 to 20 parts by weight, and (C) fumed silica: 5 to 300 parts by weight.
[4]
The room-temperature-curable organopolysiloxane composition according to [3], which further contains (D) 0.1 to 10 parts by mass of a silylating agent per 100 parts by mass of component (A-1).
[5]
The room-temperature-curable organopolysiloxane composition according to [3] or [4], which does not contain an aromatic ring-containing silane coupling agent.
[6]
The room-temperature-curable organopolysiloxane composition according to any one of [3] to [5], which is a non-fluid paste with a measured value of 0 to 3 mm in a vertical slump test according to JIS A 1439.

According to the method for producing the room-temperature-curable organopolysiloxane composition of the present invention, the silicone rubber cured product has excellent storage stability in a sealed package and excellent discoloration resistance (UV discoloration resistance) after curing. It is possible to inexpensively and simply provide a dealcoholized room-temperature-curable organopolysiloxane composition that gives a

（式中、Ｒ¹は独立に炭素数１～１０の非置換又は置換の一価炭化水素基であり、ｍは１０以上の整数である。）
で示される分子鎖両末端がヒドロキシシリル基で封鎖された２３℃における粘度が２０～１，０００，０００ｍＰａ・ｓであるオルガノポリシロキサン：１００質量部、
（Ａ－２）下記一般式（２）

（式中、Ｒ²は炭素数１～１０の非置換又はハロゲン置換一価炭化水素基であり、Ｒ³は独立に炭素数１～１０の非置換の一価炭化水素基であり、ａは３又は４である。）
で示される加水分解性オルガノシラン化合物及び／又はその部分加水分解縮合物：０．２～２０質量部、及び
（Ａ－３）下記一般式（３）

（式中、Ｒ⁴は炭素数２～１０の脂肪族二価炭化水素基であり、Ｒ⁵は炭素数１～１０の脂肪族二価炭化水素基であり、Ｒ⁶及びＲ⁷はそれぞれ独立に炭素数１～１０の非置換又はハロゲン置換一価炭化水素基であり、ｂは２又は３である。）
で示されるシランカップリング剤及び／又はその部分加水分解縮合物：０．１～２０質量部
を室温（５℃以上４０℃未満）で均一に混合した後、室温で湿気遮断環境下に６時間以上静置反応させて反応生成混合物（Ａ）を得る工程、及び
［ＩＩ］：
上記反応生成混合物（Ａ）に、
上記（Ａ－２）成分：０～１８質量部（但し、工程［Ｉ］と工程［ＩＩ］の合計で（Ａ－１）成分１００質量部に対して０．２～２０質量部）、
（Ｂ）硬化触媒：０．００１～２０質量部、及び
（Ｃ）煙霧質シリカ：５～３００質量部
を配合して均一に混合する工程
を含んでなるものである。 The method for producing the room temperature curable organopolysiloxane composition of the present invention comprises:
[I]:
(A-1) the following general formula (1)

(In the formula, R ¹ is independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and m is an integer of 10 or more.)
100 parts by mass of an organopolysiloxane having a viscosity of 20 to 1,000,000 mPa s at 23 ° C. and having both ends of the molecular chain blocked with hydroxysilyl groups,
(A-2) the following general formula (2)

(wherein R ² is an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, R ³ is independently an unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and a is 3 or 4.)
A hydrolyzable organosilane compound represented by and/or a partial hydrolytic condensate thereof: 0.2 to 20 parts by mass, and (A-3) the following general formula (3)

(wherein R ⁴ is an aliphatic divalent hydrocarbon group having 2 to 10 carbon atoms, R ⁵ is an aliphatic divalent hydrocarbon group having 1 to 10 carbon atoms, and R ⁶ and R ⁷ are each independently is an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and b is 2 or 3.)
A silane coupling agent represented by and / or a partial hydrolytic condensate thereof: 0.1 to 20 parts by mass are uniformly mixed at room temperature (5 ° C. or more and less than 40 ° C.), and then at room temperature in a moisture-proof environment for 6 hours. [II]:
In the reaction product mixture (A),
Component (A-2): 0 to 18 parts by mass (however, the total of step [I] and step [II] is 0.2 to 20 parts by mass relative to 100 parts by mass of component (A-1)),
(B) curing catalyst: 0.001 to 20 parts by mass and (C) fumed silica: 5 to 300 parts by mass are blended and uniformly mixed.

The room temperature curable organopolysiloxane composition obtained by the production method of the present invention is
(A) a reaction product mixture obtained by allowing a mixture of the above components (A-1) to (A-3) in the above mixing ratio to react at room temperature in a moisture-proof environment for 6 hours or longer;
(B) a curing catalyst;
(C) fumed silica and, if necessary, (D) a silylating agent and/or a specific amount of component (A-2) above.

Step [I] will be described.
Step [I] is a step of preparing component (A), which is the main component of the room-temperature-curable organopolysiloxane composition of the present invention, and includes at least components (A-1) and (A-2) below. , and (A-3) in the amounts described later at room temperature (5° C. or more and less than 40° C.) for a predetermined period of time, and then allowed to stand at room temperature for 6 hours or more in a moisture-proof environment to form a reaction product mixture. (A) is obtained.

（式中、Ｒ¹は独立に炭素数１～１０の非置換又は置換の一価炭化水素基であり、ｍは１０以上の整数である。） Component (A-1) is an organopolysiloxane having a viscosity of 20 to 1,000,000 mPa·s at 23° C. and having both molecular chain terminals blocked with hydroxysilyl groups represented by the following general formula (1). .

(In the formula, R ¹ is independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and m is an integer of 10 or more.)

In the formula, R ¹ is independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl. tert-butyl group, pentyl group, neopentyl group, hexyl group, heptyl group, octyl group, 2-ethylhexyl group, nonyl group, alkyl group such as decyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, etc. alkenyl groups such as cycloalkyl groups, vinyl groups and allyl groups; aryl groups such as phenyl groups and tolyl groups; 3-trifluoropropyl group and the like. Among these, a methyl group, a phenyl group and a 3,3,3-trifluoropropyl group are preferred, and a methyl group is particularly preferred. R ¹ may be the same group or different groups.

In addition, m is an integer of 10 or more, and the viscosity of the organopolysiloxane at 23° C. is 20 to 1,000,000 mPa·s, preferably 500 to 100,000 mPa·s. It is an integer of about 3,000, preferably 20 to 2,000, more preferably 30 to 1,200. If m is less than 10, the viscosity of the composition according to the present invention becomes too low, impairing the workability, and the elastic conformability of the cured product after curing cannot be obtained.

Component (A-1) has a viscosity at 23° C. of 20 to 1,000,000 mPa·s, preferably 500 to 100,000 mPa·s. If the viscosity is less than 20 mPa·s, the workability of the composition according to the present invention is impaired, and the elastic followability of the cured product after curing cannot be obtained. Not only is the production of the composition itself difficult, but the workability is remarkably deteriorated. The viscosity can be measured by a rotational viscometer (for example, BL type, BH type, BS type, cone plate type, rheometer, etc.) (same below).
Component (A-1) may be used alone or in combination of two or more.
It is preferable that all of the component (A-1) be blended in step [I].

（式中、Ｒ²は炭素数１～１０の非置換又はハロゲン置換一価炭化水素基であり、Ｒ³は独立に炭素数１～１０の非置換の一価炭化水素基であり、ａは３又は４である。） Component (A-2) is a hydrolyzable organosilane compound such as an alkoxysilane represented by the following general formula (2) and/or a partial hydrolytic condensate thereof, and the molecular chain terminal silanol of component (A-1) Terminal blocking agent of component (A-1) for blocking silanol groups at both ends and/or one end of the molecular chain with hydrolyzable silyl groups by hydrolysis/condensation reaction with groups (hydroxyl groups bonded to silicon atoms) , a cross-linking agent (curing agent) of the composition, and a dehydrating agent.

(wherein R ² is an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, R ³ is independently an unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and a is 3 or 4.)

In the formula, R ² is an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, Alkyl groups such as tert-butyl group, pentyl group, neopentyl group, hexyl group, heptyl group, octyl group, 2-ethylhexyl group, nonyl group and decyl group, cycloalkyl groups such as cyclopentyl group, cyclohexyl group and cycloheptyl group alkenyl groups such as a vinyl group and an allyl group; aryl groups such as a phenyl group and a tolyl group; and a trifluoropropyl group. Among these, preferred are methyl group, ethyl group, propyl group, vinyl group, phenyl group and 3,3,3-trifluoropropyl group, and more preferred are methyl group, vinyl group and phenyl group.

R ³ is independently an unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and examples of R ² are the same as those other than halogen-substituted monovalent hydrocarbon groups, and methyl group and ethyl group are examples. Preferred are methyl groups. R ³ may be the same or different, and R ² and R ³ may be the same or different.
Moreover, a is 3 or 4.

Component (A-2) includes tetramethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane, phenyltrimethoxysilane, tetraethoxysilane, methyltriethoxysilane, vinyltriethoxysilane, phenyltriethoxysilane, and tetrapropoxysilane. , tetraisopropoxysilane, ethyltrimethoxysilane, normal-propyltrimethoxysilane, isobutyltrimethoxysilane, normal-butyltrimethoxysilane, normal-hexyltrimethoxysilane, decyltrimethoxysilane, etc. (organo)alkoxysilane compounds and parts thereof A hydrolysis condensate is mentioned. In the present invention, the partial hydrolysis condensate is formed by partially hydrolyzing and condensing the hydrolyzable organosilane compound, and has at least two remaining hydrolyzable groups such as alkoxy groups in the molecule. Preferably, it means an organosiloxane oligomer having 3 or more (the same shall apply hereinafter).

In the present invention, the component (A-2) hydrolyzable organosilane compounds and/or partial hydrolyzed condensates thereof may be used singly or in combination of two or more. Among them, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, isobutyltrimethoxysilane, hexyltrimethoxysilane, decyltrimethoxysilane, vinyltrimethoxysilane, which can be obtained industrially at relatively low cost, Vinyltriethoxysilane and partial hydrolytic condensates thereof are preferred, and methyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane and partial hydrolytic condensates thereof are particularly preferred.

The amount of component (A-2) is 0.2 to 20 parts by mass, preferably 1 to 15 parts by mass, more preferably 3 to 10 parts by mass, per 100 parts by mass of component (A-1). is. If the amount is too small, the end-blocking rate will be poor, making it impossible to produce a room-temperature-curable organopolysiloxane composition. If the amount is too large, the curing speed of the room-temperature-curable organopolysiloxane composition becomes slow, and not only does the mechanical properties after curing deteriorate, but it is also economically disadvantageous. Since the (A-2) component is a terminal blocking agent for the (A-1) component and also acts as a cross-linking agent (curing agent) for the composition, in the production method of the present invention, Component (A-2) may be blended in its entirety (100% by mass) in step [I], but part of component (A-2) (for example, 10 to 90% by mass, particularly 20 to 80% by mass) %, further 30 to 70% by mass) are blended in step [I], and the remainder of component (A-2) (for example, 90 to 10% by mass, particularly 80 to 20% by mass, further 70 to 30% by mass %) may be blended in step [II].

（式中、Ｒ⁴は炭素数２～１０の脂肪族二価炭化水素基であり、Ｒ⁵は炭素数１～１０の脂肪族二価炭化水素基であり、Ｒ⁶及びＲ⁷はそれぞれ独立に炭素数１～１０の非置換又はハロゲン置換一価炭化水素基であり、ｂは２又は３である。） Component (A-3) has two amino groups (one primary amino group and one secondary amino group (imino group)) in one molecule, represented by the following general formula (3). and is an amino-functional silane coupling agent and/or a partial hydrolysis condensate thereof that does not contain an aromatic ring in the molecule, wherein the molecular chain terminal silanol group of component (A-1) and component (A-2) Both ends and/or one end of the molecular chain of component (A-1) are capped with hydrolyzable silyl groups by hydrolysis/condensation reaction with the hydrolyzable organosilane compound and/or partial hydrolyzed condensate thereof. It exhibits important effects as a terminal-blocking catalyst (condensation catalyst) that advances the terminal-blocking reaction during the process, and as an adhesion-imparting agent that imparts adhesiveness to the room-temperature-curable organopolysiloxane composition of the present invention.

(wherein R ⁴ is an aliphatic divalent hydrocarbon group having 2 to 10 carbon atoms, R ⁵ is an aliphatic divalent hydrocarbon group having 1 to 10 carbon atoms, and R ⁶ and R ⁷ are each independently is an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and b is 2 or 3.)

In the formula, R ⁴ is an aliphatic divalent hydrocarbon group having 2 to 10 carbon atoms, such as ethylene group, propylene group (trimethylene group, methylethylene group), butylene group (tetramethylene group, methylpropylene group), alkylene groups such as pentamethylene group, hexamethylene group, heptamethylene group and octamethylene group, and R ⁵ is a C 1-10 aliphatic divalent hydrocarbon group such as methylene group, ethylene group, Alkylene groups such as a propylene group (trimethylene group, methylethylene group), butylene group (tetramethylene group, methylpropylene group), pentamethylene group, hexamethylene group, heptamethylene group, octamethylene group, and the like can be mentioned.
In the formula, R ⁶ and R ⁷ are each independently an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and include the same groups as those for R ² above.
Moreover, b is 2 or 3.

The (A-3) component silane coupling agent and/or its partial hydrolysis condensate does not contain an aromatic ring or preferably a conjugated aliphatic unsaturated double bond in its molecular structure. When using compounds with these and/or their hydrolyzed condensates, the appearance of the cured silicone rubber after curing will turn yellow after being exposed to ultraviolet rays, so it is used for outdoor sealing or when exposed to germicidal lamp light. Not preferred when used in interior sealing applications.

Examples of component (A-3) include 3-(2-aminoethylamino)propyltrimethoxysilane, 3-(2-aminoethylamino)propylmethyldimethoxysilane, 3-(2-aminoethylamino)propyltri ethoxysilane, 3-(2-aminoethylamino)propylmethyldiethoxysilane, 3-(3-aminopropylamino)propyltrimethoxysilane, 3-(8-aminooctylamino)propyltrimethoxysilane, [(2- 3-(2-aminoethylamino)propyltrimethoxysilane and/or Alternatively, a partially hydrolyzed condensate thereof is preferable because it is inexpensive and highly effective.

Component (A-3) is used in an amount of 0.1 to 20 parts by mass, preferably 0.5 to 10 parts by mass, per 100 parts by mass of component (A-1). If the amount is less than 0.1 part by mass, sufficient adhesiveness cannot be obtained, and if the amount exceeds 20 parts by mass, not only is the cost disadvantageous, but also the hot water resistance adhesiveness may be lowered.
Component (A-3) may be used alone or in combination of two or more.
It is preferable that all of the component (A-3) be blended in step [I].

The reaction product mixture of component (A) is a mixture of components (A-1), (A-2), and (A-3) in a predetermined ratio at room temperature (5° C. or more and less than 40° C.). After that, it is obtained by allowing the reaction to stand at room temperature (5° C. or more and less than 40° C.) in a moisture-proof environment for 6 hours or more.

The mixing operation of components (A-1), (A-2), and (A-3) is carried out at room temperature (5° C. or more and less than 40° C., particularly 23° C.±15° C.) in an open system, Any method in a closed system may be used, but if the mixing time is too long, the hydrolysis reaction and condensation reaction of the components will proceed, so mixing in a closed system is preferred. The mixing operation time of components (A-1), (A-2) and (A-3) is, for example, 5 to 60 minutes, preferably 10 to 30 minutes.

Next, the mixture of components (A-1), (A-2), and (A-3) is placed at room temperature (5° C. or higher and lower than 40° C., particularly 23° C.±15° C.) for 6 hours in a moisture-proof environment. Above, the reaction is allowed to stand, preferably for 6 to 72 hours. If the standing reaction time is less than 6 hours, the reaction does not proceed sufficiently, and in step [II] described later, the viscosity increases after component (B) is added, impairing workability, or the viscosity increases and gels and cures at room temperature. In this case, the production itself of the organic organopolysiloxane composition becomes impossible. In order to raise the temperature to 40° C. or higher, heating with a heat source is required, which not only impairs economic efficiency, but also components (A-2) and (A-3) volatilize and solidify on the inner wall surface of the head space of the mixing device. Since problems such as
In addition, the static reaction is carried out in a moisture-proof environment as described above, and is preferably carried out in a sealed state, or in a state where dry air or an inert gas is vented or filled, for example, in a drum, container, or tank. For example, reacting.

After uniformly mixing at room temperature (5 ° C. or higher and lower than 40 ° C.), the reaction product mixture (A) left to react at room temperature (5 ° C. or higher and lower than 40 ° C.) for 6 hours or longer contains (A-1) component , (A-2) component, and (A-3) component reacted with each raw material component left unreacted, and (A-1) component and (A-2) component reacted to form (A-1) component Both terminal hydroxyl groups are blocked with alkoxysilyl groups Organopolysiloxane with both terminals blocked with alkoxysilyl groups, only one terminal is blocked with an alkoxysilyl group, and the hydroxyl group at the other terminal remains as it is and organopolysiloxane in which some of the alkoxy groups of the terminal alkoxysilyl groups are hydrolyzed to form silanol, organopolysiloxane in which component (A-2) has reacted with the silanol, and further ( In addition to organopolysiloxanes of many structures, such as organopolysiloxanes having a structure in which the alkoxysilyl groups of component A-3) react with the hydroxyl groups of component (A-1), components (A-2) and ( Since the A-3) component is a mixture consisting of an extremely large number of components, such as partially hydrolyzed components, and components that have undergone condensation reactions and/or with each other to form a partially hydrolyzed condensate, reaction by analysis Identification of the composition of the product mixture (A) is virtually impossible.

After reacting for 6 hours or more at room temperature (5°C or more and less than 40°C), the reaction product mixture is noticeable as long as it is stored in a sealed container or kept in a state where it is ventilated with dry air or inert gas without moisture. However, after reacting for 6 hours or more, it is preferable to use it within one year, more preferably within a few days. It is good for stably obtaining the properties of the curable organopolysiloxane composition.

Next, step [II] will be described.
Step [II] includes the reaction product mixture (A) obtained in step [I] above, (B) a curing catalyst, (C) fumed silica, and optionally (A-2) the general formula ( 2) comprises the step of blending and uniformly mixing the hydrolyzable organosilane compound and/or its partial hydrolyzed condensate.

(A-2) The hydrolyzable organosilane compound represented by the general formula (2) and/or its partial hydrolytic condensate is blended in its entirety (100% by mass) in step [I] as described above. However, since it also acts as a cross-linking agent (hardening agent) for the composition, it can be blended in step [II] and used as a cross-linking agent (hardening agent) for the composition.
The component (A-2) used in steps [I] and [II] may be the same or different.

When component (A-2) is also blended in step [II], part of component (A-2) (for example, 10 ~90% by mass, particularly 20 to 80% by mass, further 30 to 70% by mass) is blended in step [I], and the remainder of component (A-2) (eg 90 to 10% by mass, particularly 80 to 20% by mass, more preferably 70 to 30% by mass) is blended in step [II].
Specifically, when blending the (A-2) component in the step [II], 0.02 to 18 parts by mass with respect to 100 parts by mass of the (A-1) component (however, the step [I] and the step [ II] in total is 0.2 to 20 parts by mass with respect to 100 parts by mass of component (A-1)), especially 0.5 to 12 parts by mass (provided that step [I] and step [II] The total amount is 1 to 15 parts by mass with respect to 100 parts by mass of component (A-1)), and further 1 to 8 parts by mass (however, the total of step [I] and step [II] (A-1 ) is 3 to 10 parts by mass per 100 parts by mass of the component.). If the amount of component (A-2) in step [II] is too small, the stability of the resulting composition during long-term storage (storage) is impaired, or the viscosity increases rapidly during production, impairing workability. If the amount is too large, the deep-part curability of the resulting composition may be slowed, the elongation of the cured product after curing may be reduced, and the adhesion performance may be reduced.

Examples of curing catalysts for component (B) include organic carboxylates, alkoxides, and chelate compounds of metals such as tin, titanium, zirconium, aluminum, iron, antimony, bismuth, and manganese. More specifically, dibutyl Tin compounds such as tin dilaurate, dibutyltin dioctoate, dioctyltin dilaurate, dibutyltin maleate ester, dimethyltin dineodecanoate, dibutyltin dimethoxide, dioctyltin dineodecanoate, stannus octoate; aluminum tris(acetyl acetonate), aluminum tris(ethylacetoacetate), diisopropoxyaluminum ethylacetoacetate, triethoxyaluminum; organic zirconium compounds such as nitrate and tributoxy zirconium stearate; ) titanium, titanium chelate compounds such as diisopropoxybis(ethylacetoacetate)titanium, dibutoxybis(methylacetoacetate)titanium, amine compounds such as dibutylamine, laurylamine, tetramethylguanidine, tetramethylguanidylpropyltrimethoxysilane and salts thereof are exemplified. These compounds can be used individually by 1 type or in combination of 2 or more types. Since the room-temperature-curable organopolysiloxane composition of the present invention has good curability and little change in appearance after curing, tin compounds and bismuth compounds are preferred. Among them, alkyltin and bismuth carboxylates are preferred. Preferably.

The amount of component (B) added is 0.001 to 20 parts by mass, preferably 0.1 to 10 parts by mass, per 100 parts by mass of component (A-1). If the amount of component (B) added is too small, the curing speed may slow down or may cause poor curing. In addition to impairing the stability during storage (storage), it is also economically disadvantageous.

Component (C) is fumed silica, which is produced by a dry method using a chlorosilane compound as a starting material, and preferably has a BET specific surface area of 50 m ² /g or more, more preferably 80 to 400 m ^{2 .} /g. Fumed silica is surface-treated with an organosilicon compound such as a chlorosilane compound such as methyltrichlorosilane or dimethylchlorosilane, a silazane compound such as hexamethylsilazane, or a low-molecular-weight siloxane compound such as hexamethyldisiloxane or octamethylcyclotetrasiloxane. Although it is preferable to use silica that is not surface-treated, it is also possible to use silica as it is, giving priority to economic efficiency.

Component (C) is added in an amount of 5 to 300 parts by mass, preferably 10 to 100 parts by mass, per 100 parts by mass of component (A-1). If the amount of component (C) is too small, the resulting composition will have reduced thixotropic properties and the required non-flowability will be impaired, making it impossible to obtain good workability. I can't work too much.

In addition to the components (A) to (C) described above, it is preferable to add (D) a silylating agent as an optional component to the room-temperature-curable organopolysiloxane composition according to the present invention. Component (D) further improves the storage stability of the present composition by silylating alcohol compounds, etc., which may be present in minute amounts in the present composition, and can be stored in a sealed container for a long period of time. It also functions to impart good mechanical properties to the cured product of the room-temperature-curable organopolysiloxane composition of the present invention.

Examples of the silylating agent of component (D) include organosilazane compounds such as hexamethyldisilazane and divinyltetramethyldisilazane; organosilylurea compounds such as N,N-bis(trimethylsilyl)urea; trimethylsilyl)acetamide, O-methyl-O-trimethylsilylmethylketene acetal, N-trimethylsilyldiethylamine, etc., which are compounds capable of silylating the alcoholic hydroxyl group (C-OH group), and room-temperature curing according to the present invention. Anything that does not adversely affect the properties of the organopolysiloxane composition can be used. Organosilazane compounds and organosilylurea compounds are preferably used.

When component (D) is blended, its blending amount is in the range of 0.1 to 10 parts by mass, preferably 0.5 to 5 parts by mass, per 100 parts by mass of component (A-1). Within range. This is because if the amount of component (D) is less than the lower limit of the above range, the desired effects may not be obtained. is not realistic.

Component (D) can be blended in either step [I] and/or step [II] in the production method of the present invention.

[Other ingredients]
In addition to the above components, generally known additives may be used as long as they do not inhibit the effects of the present invention. Additives include precipitated colloidal calcium carbonate, pulverized heavy calcium carbonate, fine quartz powder, titanium dioxide powder, diatomaceous earth powder, aluminum hydroxide powder, finely divided alumina, magnesia powder, zinc oxide powder, and silane. silazanes, and fine powder inorganic fillers surface-treated with low-polymerization-degree polysiloxanes.
When such an inorganic filler is used, the amount added is preferably 1 to 200 parts by weight, more preferably 10 to 150 parts by weight, per 100 parts by weight of component (A-1).

Other additives include monosilanols such as trimethylsilanol and diphenylmethylsilanol, and dialkoxysilanes such as diphenyldimethoxysilane and dimethyldimethoxysilane, which are components for reducing the modulus of the cured silicone rubber after curing. dimethylpolysiloxane with one end blocked with a hydroxyl group and the other end with a trimethylsiloxy group, plasticizers, both end trimethylsiloxy group-blocked dimethylpolysiloxanes as diluents, isoparaffins, etc., platinum compounds as flame retardants, Zinc carbonate powder, optionally polyether as a thixotropic agent, pigments, dyes, colorants such as fluorescent whitening agents, heat resistance improvers such as red iron oxide and cerium oxide, cold resistance improvers, rust inhibitors, Antifungal agents, antibacterial agents and the like can be mentioned, and these additives can be added within a range that does not impair the purpose of the present invention. Solvents such as toluene, xylene, solvent volatile oils, cyclohexane, methylcyclohexane, and low boiling isoparaffins may also be added.

Other components can be blended in either step [I] and/or step [II] in the production method of the present invention, but are preferably blended in step [II].

The room-temperature-curable organopolysiloxane composition according to the present invention preferably does not contain a silane coupling agent containing an aromatic ring, because the appearance of the obtained silicone rubber cured product after ultraviolet irradiation is yellowed.

In the method for producing the room-temperature-curable organopolysiloxane composition of the present invention, the step [II] includes the components (A) to (C) described above, and optionally components (A-2), (D), and others. In a dry atmosphere and/or under reduced pressure degassing, the components of (1) are blended according to a conventional method and uniformly mixed to produce a so-called one-component type. The mixing temperature in step [II] may be room temperature (5° C. or more and less than 40° C., particularly 23° C.±15° C.), and the mixing time is preferably 1 to 60 minutes, particularly 5 to 10 minutes.

In the method for producing the room-temperature-curable organopolysiloxane composition of the present invention, as the best embodiment, the preparation of component (A) (step [I]) is carried out in a raw material tank, and components (A) to (C) are , and, if necessary, the addition and mixing of (A-2) component, (D) component, and other components (step [II]) in an inline plant without contacting the outside air, semi-continuously or continuously. is most preferred.

The room-temperature-curable organopolysiloxane compositions obtained in steps [I] and [II] are preferably stored in a hermetically sealed package.

The room-temperature-curable organopolysiloxane composition obtained by the production method of the present invention is a non-fluid paste with a measured value of 0 to 3 mm, particularly 0 to 1 mm in a vertical slump test according to JIS A 1439. preferable. To explain the vertical slump test in accordance with JIS A 1439 in detail, a polyethylene sheet (thickness of 0.5 mm or less) 1 is placed on the inner bottom of a grooved container having joints of width 20 mm × depth 10 mm × length 150 mm. Lay a piece, fold it back and fix it on the outside of the container, and place the room temperature curable organopolysiloxane composition inside the grooved container that has been left to stand at a temperature of 23 ° C ± 2 ° C for 24 hours or more so as to avoid entrainment of air. Fill by pressing, smooth the surface of the composition with a spatula or the like so that it is flush with the upper surface of the grooved container, then release the polyethylene sheet and immediately set the constant temperature to 50 ± 2 ° C. Install (suspend) the grooved container so that the joints are vertical inside and leave it for 24 hours, then remove it from the thermostat, and in an environment of 23 ± 2 ° C., the composition is in the groove part of the grooved container. Measure the distance from the bottom edge to the hanging tip.
If the measured value exceeds 3 mm, workability may be impaired, or the composition may drip downward at vertical joints on the wall surface and protrude from the joints at the bottom, or may fall off from ceiling joints.
In the present invention, as a means for making the measured value in the vertical slump test in accordance with JIS A 1439 within the above range, mixing aging of the component (A-1), the component (A-2) and the component (A-3) In the step (step [I]), the blocking reaction of the molecular chain terminal silanol group of the component (A-1) by the component (A-2) is sufficiently progressing, and in the step [II], the specified It is necessary to prepare the composition by uniformly mixing an amount of component (C) fumed silica. Moreover, when adding a plasticizer component or a solvent component to the composition according to the present invention, it is desirable to appropriately adjust the thixotropy by increasing the blending amount of the component (C).

The room-temperature-curable organopolysiloxane composition obtained by the production method of the present invention is generally cured by the presence of moisture in the atmosphere when left in the atmosphere.

The room-temperature-curable organopolysiloxane composition obtained by the production method of the present invention can be used for various purposes, and is particularly effective for sealants and adhesives.

Examples and comparative examples of the present invention will be described below, but the present invention is not limited to the following examples. In addition, the viscosity in the examples is a value measured by a rotational viscometer at 23°C. In addition, all compositions were prepared using a “mixing stirrer (model: 5DMV-01-r)” manufactured by Dalton Co., Ltd. Room temperature means 23°C.

[Example 1]
Dimethylpolysiloxane (viscosity 50,000 mPa s, m is about 860 in formula (1)) 100 parts by mass, methyltrimethoxy A mixture was prepared by uniformly mixing 5 parts by mass of silane and 1.7 parts by mass of 3-(2-aminoethylamino)propyltrimethoxysilane at room temperature of 23° C. and normal pressure for 10 minutes, and then stopping the mixing. , the mixture was allowed to react at 23° C. under closed conditions for 18 hours to obtain a reaction product mixture 1. 100 parts by mass of the reaction product mixture 1 and 14 parts by mass of untreated fumed silica having a BET specific surface area of 150 m ² /g ("Konasil-150" manufactured by OCI) were uniformly mixed, and then both ends of the molecular chain were mixed. 40 parts by mass of dimethylpolysiloxane (viscosity 100 mPa s) blocked with trimethylsiloxy groups, 0.8 parts by mass of hexamethyldisilazane, 3 parts by mass of partial hydrolysis condensate of methyltrimethoxysilane, dioctyltin dineodeca 0.3 part by mass of noate was added, and the mixture was mixed for 10 minutes while removing air bubbles under reduced pressure until the mixture became uniform to prepare a composition 1 free of white turbidity.

[Example 2]
In Example 1, the stationary reaction time after mixing for obtaining the reaction product mixture was changed to 6 hours to obtain the reaction product mixture 2, and the reaction product mixture 2 was used instead of the reaction product mixture 1. Composition 2 without cloudiness was prepared in the same manner as in Example 1.

[Example 3]
In Example 1, 1.7 parts by mass of 3-(2-aminoethylamino)propylmethyldimethoxysilane was used instead of 1.7 parts by mass of 3-(2-aminoethylamino)propyltrimethoxysilane, and the reaction product mixture 3 was obtained, and composition 3 without cloudiness was prepared in the same manner as in Example 1, except that reaction product mixture 3 was used instead of reaction product mixture 1.

[Comparative Example 1]
Dimethylpolysiloxane (viscosity 50,000 mPa s, m is about 860 in formula (1)) 100 parts by mass, methyltrimethoxy A mixture was prepared by uniformly mixing 5 parts by mass of silane and 1.7 parts by mass of 3-(2-aminoethylamino)propyltrimethoxysilane at room temperature of 23° C. and normal pressure for 10 minutes. Parts by mass and 14 parts by mass of surface-untreated fumed silica (“Konasil-150” manufactured by OCI) having a BET specific surface area of 150 m ² /g are uniformly mixed, and both ends of the molecular chain are blocked with trimethylsiloxy groups. 40 parts by weight of dimethylpolysiloxane (viscosity 100 mPa s), 0.8 parts by weight of hexamethyldisilazane, 3 parts by weight of partial hydrolysis condensate of methyltrimethoxysilane, 0.3 parts by weight of dioctyltin dineodecanoate and mixing was started under reduced pressure while air bubbles were removed.

[Comparative Example 2]
In Example 1, the stationary reaction time after mixing for obtaining the reaction product mixture was changed to 3 hours to obtain the reaction product mixture 4, and the reaction product mixture 4 was used instead of the reaction product mixture 1. A composition was prepared in the same manner as in Example 1, but after adding dioctyltin dineodecanoate and mixing under reduced pressure, rapid thickening and gelation occurred, and the composition could not be obtained. .

[Comparative Example 3]
In Example 1, 1.7 parts by mass of 3-aminopropyltrimethoxysilane was used instead of 1.7 parts by mass of 3-(2-aminoethylamino)propyltrimethoxysilane to obtain a reaction product mixture 5, and the reaction A composition 4 without white turbidity was prepared in the same manner as in Example 1, except that the reaction product mixture 5 was used instead of the product mixture 1.

（Ｍｅはメチル基である。） [Comparative Example 4]
In Example 1, 1.7 parts by mass of an amino group-containing silane represented by the following formula was used instead of 1.7 parts by mass of 3-(2-aminoethylamino)propyltrimethoxysilane to obtain a reaction product mixture 6. A composition 5 without cloudiness was prepared in the same manner as in Example 1, except that the reaction product mixture 6 was used instead of the reaction product mixture 1.

(Me is a methyl group.)

[Comparative Example 5]
In Example 1, 1.7 parts by mass of 3-aminopropyltriethoxysilane was used instead of 1.7 parts by mass of 3-(2-aminoethylamino)propyltrimethoxysilane to obtain a reaction product mixture 7, and the reaction A composition 6 without white turbidity was prepared in the same manner as in Example 1, except that the reaction product mixture 7 was used instead of the product mixture 1.

The room temperature curable organopolysiloxane compositions obtained in Examples 1 to 3 and Comparative Examples 3 to 5 were evaluated for the following properties. These results are shown in Table 1 together with whether or not the room temperature curable organopolysiloxane compositions in Examples 1 to 3 and Comparative Examples 1 to 5 were produced.

[slump]
In order to evaluate the non-fluidity required as a sealant, a slump test according to JIS A 1439 was performed under vertical conditions using each composition obtained in the above Examples and Comparative Examples. If the result was 3 mm or less, it was accepted, and if it exceeded 3 mm, or if it fell and no measured value could be obtained, it was recorded as dropped and rejected.

[Dry time to the touch]
Using each composition obtained in the above examples and comparative examples, a dry-to-the-touch time test in accordance with JIS A 1439 was performed, and if it was within 30 minutes, it passed, and if it exceeded 30 minutes, it failed. and

[Hardness]
Each composition obtained in the above examples and comparative examples was molded into a sheet with a thickness of 2 mm, left to stand in a constant temperature and humidity room at 23 ° C. and 50% RH, and cured for 7 days. The sheets were stacked to a total thickness of 6 mm, and the hardness was measured with a type A durometer according to JIS K 6253. A type A durometer hardness of 10 or more was considered acceptable, and a type A durometer hardness of less than 10 was considered unacceptable.

[Elongation at break]
A sheet piece having a thickness of 2 mm was produced in the same manner as in the hardness test, a dumbbell No. 2 conforming to JIS K 6251 was produced from the sheet piece, and the elongation at break was measured at a tensile speed of 500 mm/min. If an elongation at break of 200% or more was obtained, it was judged as acceptable.

[Aluminum adhesion]
After cleaning the surface of a pure aluminum test piece (thickness 1 mm) with toluene, each composition obtained in the above examples and comparative examples was used to prepare a shear adhesion test piece specified in JIS K 6249. 5 cm ² and 2 mm adhesion thickness, and left to cure for 7 days at 23° C. and 50% RH to obtain a test specimen. After curing, the specimen was pulled at a shear tensile speed of 50 mm/min, and the cohesive failure rate of the composition on the aluminum surface after fracture was measured. A case where the cohesive failure rate was 80% or more was regarded as acceptable.

[Storability]
The prepared composition was filled into a 330 ml capacity polycartridge for a polyethylene sealing material, and sealed with a polyethylene inner plug. After that, the cartridge was placed in a constant temperature bath at 70° C., stored for 7 days, taken out, and then left standing at 23° C. and 50% RH for 24 hours. The hardness was measured by the method. In the case of "falling" in the slump test (failed), the storage stability was not evaluated. As a criterion for evaluating storage stability, if the hardness is less than ± 10 points from the hardness before storage (immediately after preparation), the difference is ± 10 points or more from the hardness before storage (immediately after preparation). When it occurred, it was set as failure.

[UV discoloration]
The sheet piece prepared in the hardness test is left to stand under a germicidal lamp for 24 hours, and the color change in the appearance before and after irradiation with the germicidal lamp is visually observed, and the state of discoloration is described. was judged as unacceptable, and when almost no discoloration was felt, it was judged as acceptable.

Claims (6)

[I]:
(A-1) the following general formula (1)

(In the formula, R ¹ is independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and m is an integer of 10 or more.)
100 parts by mass of an organopolysiloxane having a viscosity of 20 to 1,000,000 mPa s at 23 ° C. and having both ends of the molecular chain blocked with hydroxysilyl groups,
(A-2) the following general formula (2)

(wherein R ² is an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, R ³ is independently an unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and a is 3 or 4.)
A hydrolyzable organosilane compound represented by and/or a partial hydrolytic condensate thereof: 0.2 to 20 parts by mass, and (A-3) the following general formula (3)

(wherein R ⁴ is an aliphatic divalent hydrocarbon group having 2 to 10 carbon atoms, R ⁵ is an aliphatic divalent hydrocarbon group having 1 to 10 carbon atoms, and R ⁶ and R ⁷ are each independently is an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and b is 2 or 3.)
A silane coupling agent represented by and / or a partial hydrolytic condensate thereof: 0.1 to 20 parts by mass are uniformly mixed at room temperature (5 ° C. or more and less than 40 ° C.), and then at room temperature in a moisture-proof environment for 6 hours. [II]:
In the reaction product mixture (A),
Component (A-2): 0 to 18 parts by mass (however, the total of step [I] and step [II] is 0.2 to 20 parts by mass relative to 100 parts by mass of component (A-1)),
(B) curing catalyst: 0.001 to 20 parts by mass; and (C) fumed silica: 5 to 300 parts by mass. 2. The method according to claim 1, wherein in steps [I] and/or [II], 0.1 to 10 parts by mass of (D) a silylating agent is blended with 100 parts by mass of component (A-1). A method for producing a room temperature curable organopolysiloxane composition. (A-1) the following general formula (1)

(In the formula, R ¹ is independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and m is an integer of 10 or more.)
100 parts by mass of an organopolysiloxane having a viscosity of 20 to 1,000,000 mPa s at 23 ° C. and having both ends of the molecular chain blocked with hydroxysilyl groups,
(A-2) the following general formula (2)

(wherein R ² is an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, R ³ is independently an unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and a is 3 or 4.)
A hydrolyzable organosilane compound represented by and/or a partial hydrolytic condensate thereof: 0.2 to 20 parts by mass, and (A-3) the following general formula (3)

(wherein R ⁴ is an aliphatic divalent hydrocarbon group having 2 to 10 carbon atoms, R ⁵ is an aliphatic divalent hydrocarbon group having 1 to 10 carbon atoms, and R ⁶ and R ⁷ are each independently is an unsubstituted or halogen-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and b is 2 or 3.)
The silane coupling agent represented by and/or its partial hydrolysis condensate: 0.1 to 20 parts by mass of the mixture at the above mixing ratio is allowed to stand at room temperature for 6 hours or more in a moisture-proof environment to react. product mixture (A),
Component (A-2): 0 to 18 parts by mass (0.2 to 20 parts by mass based on 100 parts by mass of component (A-1) in the entire composition),
A room temperature curable organopolysiloxane composition comprising (B) curing catalyst: 0.001 to 20 parts by weight, and (C) fumed silica: 5 to 300 parts by weight. 4. The room-temperature-curable organopolysiloxane composition according to claim 3, further comprising (D) a silylating agent in an amount of 0.1 to 10 parts by weight per 100 parts by weight of component (A-1). 5. The room-temperature-curable organopolysiloxane composition according to claim 3, which does not contain a silane coupling agent containing an aromatic ring. The room temperature curable organopolysiloxane composition according to any one of claims 3 to 5, which is a non-fluid paste with a measured value of 0 to 3 mm in a vertical slump test according to JIS A 1439.