JP2015113377A - Method for producing room temperature-curable organopolysiloxane composition, sealant, and article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a room temperature-curable organopolysiloxane composition, which provides a cured material with good appearance even when using silica fine powder having little adhesive moisture and not being surface-treated, and furthermore possesses good thixotropic property and storage stability, and to provide a construction sealant using the composition.SOLUTION: Provided is a method for producing a room temperature-curable organopolysiloxane composition comprising (A) a diorganopolysiloxane represented by the formula (1) (Ris a primary hydrocarbon group; and m is an integer of 10 or more); (B) an organosilane compound represented by the formula (2) or its partial hydrolysis condensation product (Rand Rare primary hydrocarbon groups; and a is 3 or 4); (C) silica fine powder having a moisture content of less than 0.2 mass%; and (D) a curing catalyst, the method comprising steps of previously mixing (A) and (B) to prepare a uniform mixture and adding (C) to the mixture.

Description

  The present invention is a method for producing a room temperature curable organopolysiloxane composition that is cured at room temperature to form a silicone rubber. More specifically, the use of untreated silica with a small amount of adhering moisture makes the appearance good and still good. The present invention relates to a method for producing a room temperature curable organopolysiloxane composition having thixotropy and storage stability, an architectural sealant produced by this method, and an article bonded and / or sealed with a cured product of the architectural sealant. .

  Room temperature curable (RTV) silicone rubber compositions that are crosslinked by moisture are easy to handle and have excellent weather resistance and electrical properties. Therefore, various materials such as sealing materials for building materials and adhesives in the electrical and electronic fields are used. Used in the field. A general room temperature curable organopolysiloxane composition comprises a diorganopolysiloxane having a silanol group or an alkoxysilyl group at the end of a molecular chain, a curing agent, an alkoxysilane containing an aminoalkyl group, and a curing catalyst. In order to impart conductivity, tensile strength, etc., various fillers are mixed as necessary.

  By the way, when a room temperature curable (RTV) silicone rubber composition is used as a sealing material for industrial, architectural, or structural purposes, it is important that the applied sealing material does not sag. Therefore, in general, silica that is excellent in dispersibility with silicone and can impart reinforcement is used. In general, silica has a large number of silanol groups on the surface, so that moisture adheres with time. In order to improve this, the surface is treated with a silane compound such as dichlorodimethylsilane or hexamethyldisilazane. Treated silica has a hydrophobic surface, which suppresses moisture adsorption, and has excellent dispersibility with silicone, so it can be used in a variety of applications such as sealing materials for building materials and adhesives in the electrical and electronic fields. It is universally added to the room temperature curable (RTV) silicone rubber composition used.

However, it is inevitable that the surface treatment leads to an increase in costs such as raw material costs for the treatment agent and treatment process costs. In addition, compounds such as hydrogen chloride and ammonia gas are by-produced by the treatment process, and are not environmentally friendly. Therefore, if silica that is not surface-treated can be used, it is considered possible to produce an environment-friendly room temperature curable (RTV) silicone rubber composition in addition to cost reduction.
However, since silica that has not been surface-treated has a concern about moisture adhesion over time as described above, the curing agent in the room temperature curable (RTV) silicone rubber composition is hydrolyzed or the composition is gelled. There are problems such as.

Further, it is generally known that when silica that has not been surface-treated is used, the sealing material drips (that is, inferior in slump resistance or thixotropy).
As a technique for suppressing such sagging, it is common to add sagging prevention agents described in JP-A-56-853 and JP-A-62-1355560 (Patent Documents 1 and 2). Known to. However, in order to suppress dripping, it is necessary to add a large amount of dripping preventing agent, and there is a problem that the composition becomes expensive. Moreover, since the sag-preventing agent has a large molecular weight, there is also a problem that the compatibility with the base polymer of the composition is poor.

As a method of suppressing dripping without using these additives (sag-preventing agents), those described in JP-A-2-41361 (Patent Document 3) are known. When the oxime curing agent and the base polymer are mixed in advance before addition of the silica that has not been surface-treated, dripping of the room temperature curable (RTV) silicone rubber composition can be suppressed. However, as described above, silica that has not been surface-treated has a large amount of moisture adhering over time, so that the appearance of the resulting silicone rubber is poor in applications that require design properties such as sealing materials for building materials ( For example, the smoothness of the surface of the sealing material may be impaired).
The cause of this is presumed to be a phenomenon that occurs when silanol on the silica surface is treated with a curing agent and chemically interacts in or between silicas with the adhering moisture.

JP 56-853 A JP-A-62-1355560 Japanese Patent Laid-Open No. 2-41361

  The present invention has been made in view of the above circumstances, and even when a fine silica powder such as fumed silica that has a low amount of adhering moisture and is not surface-treated is used, the appearance of the resulting cured product is improved (cured product). Is superior in surface smoothness), and has good thixotropy and storage stability, a method for producing a room temperature curable organopolysiloxane composition, a building sealing material produced by this method, and curing of the building sealing material It is an object to provide an article that is adhered and / or sealed with an object.

  As a result of intensive studies to achieve the above object, the inventors of the present invention have found that diorganopolysiloxane (base polymer) blocked with silanol groups at both ends of the molecular chain and a tri- or tetrafunctional hydrolyzable organosilane compound or part thereof. After preparing a mixture obtained by uniformly mixing a hydrolysis condensate (crosslinking agent) in advance, the adhering water content is less than 0.2% by mass and the surface is not treated with fumed silica, etc. The room-temperature curable organopolysiloxane composition obtained by adding and mixing the untreated surface silica fine powder has a good appearance of the resulting cured product, and also has good thixotropy and storage stability. The present invention has been found and the present invention has been made.

（式中、Ｒ¹はそれぞれ独立に炭素数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。）
で示されるジオルガノポリシロキサン、
（Ｂ）下記一般式（２）

（式中、Ｒ²、Ｒ³は、それぞれ独立に炭素数１〜１０の非置換一価炭化水素基であり、ａは３又は４である。）
で示されるオルガノシラン化合物又はその部分加水分解縮合物、
（Ｃ）付着水分量が０．２質量％未満である表面未処理のシリカ微粉末、
（Ｄ）硬化触媒
を含有する室温硬化性オルガノポリシロキサン組成物の製造方法であって、（Ａ）成分と（Ｂ）成分を予め混合して均一な混合物を調製し、該混合物に（Ｃ）成分を添加する工程を含むことを特徴とする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〕
（Ａ）成分と（Ｂ）成分を予め混合する条件が、０〜４０℃の温度範囲で、かつ５〜６０分の混合時間である〔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〕
フロージェットミキサー、スパイラルミキサー又はゲートミキサーを用いて製造するものである〔１〕又は〔２〕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。
〔４〕
建築用シーリング材用である〔１〕〜〔３〕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の製造方法。
〔５〕
〔４〕に記載の製造方法により得られた建築用シーリング材。
〔６〕
〔５〕に記載の建築用シーリング材の硬化物で接着及び／又はシーリングされた物品。 That is, the present invention provides a method for producing the following room temperature curable organopolysiloxane composition, an architectural sealant produced by this method, and an article bonded and / or sealed with a cured product of the architectural sealant. Is to provide.
[1]
(A) The following general formula (1)

(In the formula, each 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.)
Diorganopolysiloxane represented by
(B) The following general formula (2)

(Wherein R ² and R ³ are each independently an unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and a is 3 or 4.)
An organosilane compound represented by or a partially hydrolyzed condensate thereof,
(C) Untreated surface silica fine powder having an attached moisture content of less than 0.2% by mass;
(D) A method for producing a room temperature curable organopolysiloxane composition containing a curing catalyst, wherein (A) component and (B) component are mixed in advance to prepare a uniform mixture, and (C) The manufacturing method of the room temperature curable organopolysiloxane composition characterized by including the process of adding a component.
[2]
The room temperature-curable organopolysiloxane composition according to [1], wherein the conditions for previously mixing the component (A) and the component (B) are a temperature range of 0 to 40 ° C. and a mixing time of 5 to 60 minutes. Production method.
[3]
The method for producing a room temperature curable organopolysiloxane composition according to [1] or [2], which is produced using a flow jet mixer, a spiral mixer or a gate mixer.
[4]
The method for producing a room temperature-curable organopolysiloxane composition according to any one of [1] to [3], which is for a building sealing material.
[5]
A sealing material for building obtained by the production method according to [4].
[6]
An article bonded and / or sealed with a cured product of the architectural sealant according to [5].

  According to the production method of the present invention, even when a fine silica powder such as fumed silica that has a small amount of adhering moisture and is not surface-treated is used, the appearance of the resulting cured product is good and yet has good thixotropic properties. A room temperature-curable organopolysiloxane composition having storage stability is obtained. The room temperature curable organopolysiloxane composition produced by this method can be suitably used as a building sealing material.

The present invention will be described in detail below.
The method for producing the room temperature curable organopolysiloxane composition of the present invention comprises:
(A) a diorganopolysiloxane represented by the general formula (1),
(B) an organosilane compound represented by the general formula (2) or a partially hydrolyzed condensate thereof,
(C) Untreated surface silica fine powder having an attached moisture content of less than 0.2% by mass;
(D) A method for producing a room temperature curable organopolysiloxane composition containing a curing catalyst, wherein (A) component and (B) component are mixed in advance to prepare a uniform mixture, and (C) It includes a step of adding components.

（式中、Ｒ¹はそれぞれ独立に炭素数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。） [(A) component]
The component (A) used in the present invention acts as a main agent (base polymer) of the present composition, and both ends of the molecular chain represented by the following general formula (1) are silanol groups (that is, silicon atoms). It is a linear diorganopolysiloxane blocked with a bonded hydroxyl group.

(In the formula, each 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 above formula (1), each R ¹ is independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms. For example, methyl group, ethyl group, propyl group Group, isopropyl group, butyl group, isobutyl group, tert-butyl group and other alkyl groups; cyclohexyl group and other cycloalkyl groups; vinyl group, allyl group and propenyl group and other alkenyl groups; phenyl group and tolyl group and other aryl groups An aralkyl group such as a benzyl group or a phenylethyl group; and a group in which a hydrogen atom of these groups is partially substituted with a halogen atom, such as a 3,3,3-trifluoropropyl group. Among these, a methyl group is particularly preferable. R ¹ may be the same group or different groups.

  Further, m is an integer of 10 or more (usually 10 to 1,500), preferably 20 to 1,000, more preferably about 30 to 500. Particularly, the diorganopolysiloxane of component (A) at 25 ° C. It is desirable that the viscosity is an integer in the range of 25 to 500,000 mPa · s, preferably 500 to 100,000 mPa · s.

  In the present invention, the degree of polymerization (or molecular weight) is, for example, polystyrene-reduced weight average degree of polymerization (or weight average molecular weight) in gel permeation chromatography (GPC) analysis using toluene, tetrahydrofuran (THF) or the like as a developing solvent. And so on. The viscosity at 25 ° C. can be determined by a rotational viscometer (for example, BL type, BH type, BS type, cone plate type) or the like.

[Component (B)]
The component (B) is a trifunctional or tetrafunctional hydrolyzable organosilane compound having three or four hydrolyzable groups in one molecule that can react with the silanol group in the component (A) or The partial hydrolysis-condensation product acts as a crosslinking agent of the present composition, and the hydrolyzable organosilane is represented by the following general formula (2). In the present invention, the partially hydrolyzed condensate is a molecule formed by hydrolytic condensation of a part of the hydrolyzable group (organooxy group represented by -OR ³ ) in the hydrolyzable organosilane. Means a hydrolyzable siloxane oligomer in which 2 or more, preferably 3 or more hydrolyzable groups remain.

（式中、Ｒ²、Ｒ³は、それぞれ独立に炭素数１〜１０の非置換一価炭化水素基であり、ａは３又は４である。）

(Wherein R ² and R ³ are each independently an unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and a is 3 or 4.)

In said formula (2), R < ² > is a C1-C10 unsubstituted monovalent hydrocarbon group, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, tert-butyl. Alkyl groups such as cyclohexyl groups; cycloalkyl groups such as cyclohexyl groups; alkenyl groups such as vinyl groups, allyl groups, and propenyl groups; aryl groups such as phenyl groups and tolyl groups; and aralkyl groups such as benzyl groups and phenylethyl groups. It is done. In these, alkyl groups, such as a methyl group and an ethyl group, and alkenyl groups, such as a vinyl group, are preferable, and a methyl group and a vinyl group are especially preferable.

R ³ is each independently a monovalent hydrocarbon group having 1 to 10 carbon atoms which may be unsubstituted or may contain a nitrogen atom or an oxygen atom, and among these, as an unsubstituted monovalent hydrocarbon group Are the same groups as those exemplified as R ² above, and examples of the hydrolyzable group (—OR ³ ) in the component (B) include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, 1 to 4 carbon atoms such as butoxy group, isobutoxy group and tert-butoxy group, especially 1 to 2 carbon atoms such as alkoxy group, methoxymethoxy group, methoxyethoxy group, ethoxymethoxy group, ethoxyethoxy group, etc. An alkoxy-substituted alkoxy group, a dimethyl ketoxime group, a diethyl ketoxime group, an ethylmethyl ketoxime group, etc. C2-C4 alkenyloxy group such as Noxy group, C2-C4 acyloxy group such as acetoxy group, C2-C4 dialkyl such as dimethylaminoxy group, diethylaminoxy group, methylethylaminoxy group An aminoxy group etc. are mentioned, A ketoxime group, an alkoxyl group, and an isopropenoxy group are preferable, and a ketoxime group is especially preferable.
a is an integer of 3 or 4.

  Specific examples of the component (B) include alkyl silicates such as methyl silicate, ethyl silicate, and propyl silicate, methyl tris (dimethyl ketoxime) silane, methyl tris (methyl ethyl ketoxime) silane, ethyl tris (methyl ethyl ketoxime) silane, methyl tris (methyl). Isobutylketoxime) silane, vinyltris (methylethylketoxime) silane, ketoximesilane such as phenyltris (methylethylketoxime) silane, methyltrimethoxysilane, vinyltrimethoxysilane, vinyltris (β-methoxyethoxy) silane, phenyltrimethoxysilane, Alkoxysilanes such as methyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, methyl Isopropenoxy group-containing silanes such as lysopropenoxysilane, ethyltriisopropenoxysilane, vinyltriisopropenoxysilane, phenyltriisopropenoxysilane, acetoxy such as methyltriacetoxysilane, ethyltriacetoxysilane, vinyltriacetoxysilane Examples thereof include silanes and partial hydrolysis condensates of these silanes. (B) A component may be used individually by 1 type, or may use 2 or more types together.

  (B) The compounding quantity of a component is 0.1-30 mass parts with respect to 100 mass parts of (A) component, Preferably it is 0.5-20 mass parts, Most preferably, it is the range of 1-15 mass parts. If it is less than 0.1 part by mass, sufficient crosslinkability cannot be obtained, and there is a possibility that it is difficult to obtain a desired composition having rubber elasticity. Moreover, when it exceeds 30 mass parts, the hardened | cured material obtained will fall easily for a mechanical characteristic, and a cure rate may become slow.

[Component (C)]
The component (C) is a fine silica powder used as a filler (particularly a reinforcing filler) in the composition of the present invention. For example, dry silica such as calcined silica and fumed silica (fumed silica), sedimentation Examples thereof include wet silica such as silica and sol-gel silica, powder pulverized silica, and crystalline silica (quartz powder). These may be used alone or in combination of two or more. As the silica fine powder of component (C), pulverized silica and fumed silica are preferable, and fumed silica is particularly preferable.

  These silica fine powders are known to use a surface hydrophobized by a known method, if necessary. In the present invention, the surface untreated silica fine particles not subjected to surface hydrophobizing treatment are used. It is characterized by the use of powder. The use of silica powder with hydrophobized surface is not only costly and not economically disadvantageous, but also the composition has poor slump resistance (or thixotropy). For example, it is unsuitable for applications requiring slump resistance. On the other hand, silica fine powder that has not been surface-treated has a feature that moisture easily adheres due to the presence of a large number of silanol groups on the surface of the silica. The curing agent (component (B)) in the organopolysiloxane composition is hydrolyzed, causing problems such as gelation, deterioration of storage stability, and poor appearance of the cured product (deterioration of surface smoothness).

  The amount of water adhering to silica, which is an important requirement in the method of the present invention, needs to be less than 0.2% by mass (0 to 0.19% by mass) with respect to the total mass of silica. It is preferably less than 1% by mass (0 to 0.09% by mass), particularly preferably 0 to 0.05% by mass. When the amount of adhering water is 0.2% by mass or more, problems such as gelation of the room temperature curable organopolysiloxane composition and a decrease in storage stability occur as described above. The amount of water adhering to silica can be measured according to JIS K 0067: 1992 (chemical chemical reduction and residual test method).

The specific surface area of the silica of component (C) (BET method) is usually in the range of 50 to 300 m ² / g, preferably from ^{50~250m 2 / g, 50~200m 2 /} g is particularly preferred. When the specific surface area is less than 50 m ² / g, good thixotropy and rubber strength cannot be obtained, and it may be difficult to obtain a desired composition having rubber elasticity. Moreover, when it exceeds 300 m < ² > / g, the quantity which can be added with respect to organopolysiloxane is restricted, and it may become difficult to prepare the room temperature curable organopolysiloxane composition which is rich in versatility.

  The amount of component (C) is preferably 1 to 30 parts by weight, more preferably 1 to 20 parts by weight, and particularly preferably 1 to 15 parts by weight with respect to 100 parts by weight of component (A). is there. If the amount is less than 1 part by mass, good thixotropy and rubber strength cannot be obtained, and it may be difficult to obtain a desired composition having rubber elasticity. Moreover, when it exceeds 30 mass parts, kneading | mixing with the said (A) component will become difficult, and it may be difficult to prepare a favorable room temperature curable organopolysiloxane composition.

[(D) component]
The curing catalyst of component (D) is not particularly limited as long as it promotes the condensation reaction usually used in the condensation-curing room temperature curable silicone rubber composition. Moreover, you may use individually by 1 type or in mixture of 2 or more types. Examples of the curing catalyst include organic carboxylates of metal such as tin, titanium, zirconium, iron, antimony, bismuth, and manganese, alkoxides; organic titanates, and organic titanium chelate compounds. A tin compound such as dibutyltin dilaurate, dibutyltin dioctoate, dioctyltin dilaurate, dibutyltin malate ester, dimethyltin dineodecanoate, dibutyltin dimethoxide, dioctyltin dineodecanoate, stannous octoate; tetra Titanium compounds such as butyl titanate, diisopropoxybis (acetylacetonate) titanium, diisopropoxybis (ethylacetoacetate), dibutylamine, laurylamine, tetramethylguanidine, tetramethylguanidylpropylto And amine compounds and salts thereof such as methoxy silane and the like. It is preferable to add an organic tin compound because the composition of the present invention has excellent curing characteristics such as rapid curing and deep part curing, and among them, dialkyltin dialkoxide and dialkyltin dicarboxylate are preferable.

  (D) It is preferable that the addition amount of a component is 0.001-20 mass parts with respect to 100 mass parts of (A) component, More preferably, it is 0.01-5 mass parts, Most preferably, it is 0.00. It is 05-3 mass parts. When the blending amount of component (D) is less than 0.001 part by mass, sufficient crosslinkability may not be obtained. If it exceeds 20 parts by mass, it may be disadvantageous in price or the curing rate may be reduced.

[Other ingredients]
In the composition of the present invention, in addition to the components (A) to (D), a silane coupling agent (for example, (meth) acryloxy functional group, epoxy functional group, amino functional group, mercapto functional group , A hydrolyzable organosilane compound containing a monovalent hydrocarbon group containing a functional group such as a halogen atom (so-called carbon functional group) and a reaction product thereof) is a curing rate of the composition of the present invention. And from the viewpoint of further improving the adhesion to various adherends. Examples of the component include a silane compound having an alkoxysilyl group or an alkenoxysilyl group as a hydrolyzable group, such as γ-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxy. Silane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, N-β- (aminoethyl) γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, 3- ( N-aminomethylbenzylamino) propyltrimethoxysilane, N, N′-bis [3- (trimethoxysilyl) propyl] ethylenediamine, N, N-bis [3- (trimethoxysilyl) propyl] amine, γ-mercapto Propyltrimethoxysilane, γ-glycidoxypropyl Reaction of aminosilane and halogenated alkyl group-containing silane such as triisopropenoxysilane, γ-glycidoxypropylmethyldiisopropenoxysilane, reaction product of (meth) acrylsilane and aminosilane, reaction product of epoxysilane and aminosilane Examples are things. In particular, the use of a silane coupling agent containing at least one amino group in the molecule is preferred.

  It is preferable that the compounding quantity of this silane coupling agent is 0.1-20 mass parts per 100 mass parts of (A) component, More preferably, it is 0.1-10 mass parts, Most preferably, it is 0.1. -5 parts by mass. If the amount is less than 0.1 parts by mass, sufficient adhesiveness may not be obtained. If the amount exceeds 20 parts by mass, not only is the price disadvantageous, but there may be a decrease in resistance to hot water.

Moreover, you may mix | blend an additive with this invention composition other than the said component. As an additive, you may add a well-known additive in the range which does not impair the objective of this invention. For example, polyether as a wetter or thixotropy improver, terminal hydrolyzable silyl group-modified polyether, non-reactive dimethyl silicone oil as plasticizer, isoparaffin, trimethylsiloxy unit as crosslink density improver [(CH ₃ ) ₃ SiO _1/2 units] and a reticulated polysiloxane composed of SiO ₂ units.

  Furthermore, if necessary, colorants such as pigments, dyes, fluorescent brighteners, fungicides, antibacterial agents, non-reactive phenyl silicone oils as bleed oil, fluorosilicone oils, organic liquids incompatible with silicones Surface modifiers such as toluene, xylene, solvent volatile oil, cyclohexane, methylcyclohexane, low boiling point isoparaffin and other solvents may also be added.

The production method of the room temperature curable organopolysiloxane composition of the present invention is the production of the room temperature curable organopolysiloxane composition containing the components (A) to (D) described above. A method for producing a room temperature curable organopolysiloxane composition comprising the steps of mixing components in advance to prepare a uniform mixture, and adding and mixing the component (C) later to the mixture. In this case, the conditions for pre-mixing the component (A) and the component (B) to prepare a premix are 0 to 40 ° C., particularly 5 to 35 ° C. and 5 to 60 minutes, particularly 10 A mixing time of ˜30 minutes is desirable from the viewpoint of thixotropy and slump resistance of the composition.
Moreover, as conditions of the process which adds (C) component later to the mixture of (A) component and (B) component, and mixes, it is 0-60 degreeC, Especially in the temperature range of 5-50 degreeC, In addition, the mixing time of 5 to 60 minutes, particularly 10 to 40 minutes is desirable from the viewpoint of uniformly dispersing the component (C) and improving the appearance of the composition and its cured product.

  The component (D) and other optional components include the step of premixing the component (A) and the component (B), the step of adding the component (C) to the mixture, or the components (A) to (C). It may be blended in any of the stages after mixing, and may be blended in any of a plurality of stages, but in particular, a premix containing component (A) and component (B) In the step of preparing, a premix consisting of only component (A) and (B) or a premix consisting of only component (A), (B) and a plasticizer is prepared, and component (D) and other components are prepared. The optional components are preferably blended later.

  Although it does not specifically limit as a manufacturing apparatus of the room temperature curable organopolysiloxane composition formed by mix | blending these components, A flow jet mixer, a spiral mixer, a gate mixer, etc. are mentioned. Generally, the flow jet mixer and the spiral mixer are humidified, kneaded, and dissolved. However, considering the dispersion and kneading of silica with respect to silicone, the kneaded and dissolved types are preferable. In addition, these production apparatuses can continuously produce a room temperature-curable organopolysiloxane composition, and are excellent in production capacity. Since the gate mixer is excellent in kneading ability, the silica is highly dispersed and kneaded in silicone, but is suitable for batch production because of the structure of the apparatus.

  The room temperature curable organopolysiloxane composition of the present invention is produced by mixing each component by the above method, and can be stored in an atmosphere avoiding moisture. By leaving this at room temperature, Curing usually takes 5 minutes to 1 week in the presence of water.

  The room temperature curable organopolysiloxane composition obtained by the method of the present invention can be suitably used as a building sealing material.

  EXAMPLES Hereinafter, examples and comparative examples for specifically explaining the present invention will be shown, but the present invention is not limited to the following examples. The viscosity is measured with a rotational viscometer. Unless otherwise specified, each operation was performed at room temperature (20 to 25 ° C.). Further, the amount of adhering water is measured in accordance with a method defined in JIS K 0067 (1992).

[Example 1]
60 parts by mass of dimethylpolysiloxane having both ends of molecular chain blocked with silanol groups and having a viscosity of 50,000 mPa · s at 25 ° C., and dimethylpolysiloxane having both ends of molecular chain blocked with trimethylsilyl groups and having a viscosity of 100 mPa · s at 25 ° C. 10 parts by mass, 4.7 parts by mass of methyltris (methylethylketoxime) silane, and 1.4 parts by mass of vinyltris (methylethylketoxime) silane were mixed for 15 minutes under normal pressure. Next, 9.0 parts by mass of fumed silica having a moisture content of 0.05% by mass and a BET specific surface area of 130 m ² / g was mixed for 30 minutes under reduced pressure, and then both ends of the molecular chain were blocked with trimethylsilyl groups. Then, 15.4 parts by mass of dimethylpolysiloxane having a viscosity at 25 ° C. of 100 mPa · s and 0.05 part by mass of dioctyltin dilaurate were mixed for 15 minutes under reduced pressure to obtain Composition 1.

[Example 2]
60 parts by mass of dimethylpolysiloxane having both ends of molecular chain blocked with silanol groups and having a viscosity of 50,000 mPa · s at 25 ° C., and dimethylpolysiloxane having both ends of molecular chain blocked with trimethylsilyl groups and having a viscosity of 100 mPa · s at 25 ° C. 10 parts by mass, 6.6 parts by mass of methyltris (methylethylketoxime) silane, and 2.0 parts by mass of vinyltris (methylethylketoxime) silane were mixed at normal pressure for 15 minutes. Next, 9.0 parts by mass of fumed silica having an attached water content of 0.05% by mass and a BET specific surface area of 200 m ² / g was mixed for 30 minutes under reduced pressure, and then both ends of the molecular chain were blocked with trimethylsilyl groups. Then, 15.4 parts by mass of dimethylpolysiloxane having a viscosity at 25 ° C. of 100 mPa · s and 0.05 part by mass of dioctyltin dilaurate were mixed under reduced pressure for 15 minutes to obtain a composition 2.

[Comparative Example 1]
60 parts by mass of dimethylpolysiloxane having both ends of molecular chain blocked with silanol groups and having a viscosity of 50,000 mPa · s at 25 ° C., and dimethylpolysiloxane having both ends of molecular chain blocked with trimethylsilyl groups and having a viscosity of 100 mPa · s at 25 ° C. 10 parts by mass and 9.0 parts by mass of fumed silica having an attached water content of 0.05% by mass and a BET specific surface area of 130 m ² / g were mixed under reduced pressure for 30 minutes. Thereafter, 4.7 parts by mass of methyltris (methylethylketoxime) silane and 1.4 parts by mass of vinyltris (methylethylketoxime) silane were mixed for 15 minutes under normal pressure, and both ends of the molecular chain were blocked with trimethylsilyl groups at 25 ° C. A composition 3 was prepared by mixing 15.4 parts by mass of dimethylpolysiloxane having a viscosity of 100 mPa · s and 0.05 parts by mass of dioctyltin dilaurate under reduced pressure for 15 minutes. It was difficult.

[Comparative Example 2]
60 parts by mass of dimethylpolysiloxane having both ends of molecular chain blocked with silanol groups and having a viscosity of 50,000 mPa · s at 25 ° C., and dimethylpolysiloxane having both ends of molecular chain blocked with trimethylsilyl groups and having a viscosity of 100 mPa · s at 25 ° C. 10 parts by mass and 9.0 parts by mass of fumed silica having an attached moisture content of 0.05% by mass and a BET specific surface area of 200 m ² / g were mixed under reduced pressure for 30 minutes. Thereafter, 6.6 parts by mass of methyltris (methylethylketoxime) silane and 2.0 parts by mass of vinyltris (methylethylketoxime) silane were mixed for 15 minutes under normal pressure, and both ends of the molecular chain were blocked with trimethylsilyl groups at 25 ° C. A composition 4 was prepared by mixing 15.4 parts by mass of dimethylpolysiloxane having a viscosity of 100 mPa · s and 0.05 parts by mass of dioctyltin dilaurate under reduced pressure for 15 minutes. It was difficult.

[Comparative Example 3]
60 parts by mass of dimethylpolysiloxane having both ends of molecular chain blocked with silanol groups and having a viscosity of 50,000 mPa · s at 25 ° C., and dimethylpolysiloxane having both ends of molecular chain blocked with trimethylsilyl groups and having a viscosity of 100 mPa · s at 25 ° C. 10 parts by mass, α, ω-bis (3-methyldiisopropenoxysilylpropyl) polypropylene oxide 0.3 part by mass, and the amount of moisture attached is 0.05% by mass, and the BET specific surface area is 130 m ² / g. 9.0 parts by mass of vitreous silica was mixed under reduced pressure for 30 minutes. Thereafter, 4.7 parts by mass of methyltris (methylethylketoxime) silane and 1.4 parts by mass of vinyltris (methylethylketoxime) silane were mixed for 15 minutes under normal pressure. Composition 5 was obtained by mixing 15.4 parts by mass of dimethylpolysiloxane having a viscosity of 100 mPa · s and 0.05 parts by mass of dioctyltin dilaurate under reduced pressure for 15 minutes.

[Comparative Example 4]
60 parts by mass of dimethylpolysiloxane having both ends of molecular chain blocked with silanol groups and having a viscosity of 50,000 mPa · s at 25 ° C., and dimethylpolysiloxane having both ends of molecular chain blocked with trimethylsilyl groups and having a viscosity of 100 mPa · s at 25 ° C. 10 parts by mass, 4.7 parts by mass of methyltris (methylethylketoxime) silane, and 1.4 parts by mass of vinyltris (methylethylketoxime) silane were mixed for 15 minutes under normal pressure. Next, 9.0 parts by mass of fumed silica having an attached water content of 0.75% by mass and a BET specific surface area of 130 m ² / g was mixed for 30 minutes under reduced pressure, and then both ends of the molecular chain were blocked with trimethylsilyl groups. Then, 15.4 parts by mass of dimethylpolysiloxane having a viscosity at 25 ° C. of 100 mPa · s and 0.05 part by mass of dioctyltin dilaurate were mixed under reduced pressure for 15 minutes to obtain a composition 6.

[Comparative Example 5]
60 parts by mass of dimethylpolysiloxane having both ends of molecular chain blocked with silanol groups and having a viscosity of 50,000 mPa · s at 25 ° C., and dimethylpolysiloxane having both ends of molecular chain blocked with trimethylsilyl groups and having a viscosity of 100 mPa · s at 25 ° C. 10 parts by mass, 4.7 parts by mass of methyltris (methylethylketoxime) silane, and 1.4 parts by mass of vinyltris (methylethylketoxime) silane were mixed for 15 minutes under normal pressure. Next, 9.0 parts by mass of fumed silica having an attached water content of 0.62% by mass and a BET specific surface area of 150 m ² / g was mixed for 30 minutes under reduced pressure, and then both ends of the molecular chain were blocked with trimethylsilyl groups. Then, 15.4 parts by mass of dimethylpolysiloxane having a viscosity at 25 ° C. of 100 mPa · s and 0.05 part by mass of dioctyltin dilaurate were mixed for 15 minutes under reduced pressure to obtain Composition 7.

[Comparative Example 6]
60 parts by mass of dimethylpolysiloxane having both ends of molecular chain blocked with silanol groups and having a viscosity of 50,000 mPa · s at 25 ° C., and dimethylpolysiloxane having both ends of molecular chain blocked with trimethylsilyl groups and having a viscosity of 100 mPa · s at 25 ° C. 10 parts by mass, 6.6 parts by mass of methyltris (methylethylketoxime) silane, and 2.0 parts by mass of vinyltris (methylethylketoxime) silane were mixed at normal pressure for 15 minutes. Next, 9.0 parts by mass of fumed silica having an attached water content of 0.62% by mass and a BET specific surface area of 200 m ² / g was mixed for 30 minutes under reduced pressure, and then both ends of the molecular chain were blocked with trimethylsilyl groups. Then, 15.4 parts by mass of dimethylpolysiloxane having a viscosity at 25 ° C. of 100 mPa · s and 0.05 part by mass of dioctyltin dilaurate were mixed for 15 minutes under reduced pressure to obtain Composition 8.

  The following characteristics were confirmed using Composition 1 to Composition 8 prepared in Examples and Comparative Examples. The obtained results are shown in Table 1.

Hardened product appearance The prepared compositions 1 to 8 were allowed to stand for 7 days in a 23 ° C./50% RH environment so as to have a thickness of about 3 mm. The presence or absence of a cured product gel was confirmed and judged according to the following criteria.
○: No powder, no gel △: With powder, no gel ×: With powder, gel

・ Dischargeability After putting the prepared composition 1 to composition 8 in a sealable container (330 ml cartridge made of polycarbonate), a nozzle with a discharge port of φ4.5 mm is attached to the tip, and the discharge pressure is 0.2 MPa. Compositions 1 to 8 were extruded for 5 seconds. After 5 seconds, the extruded mass was measured to evaluate the dischargeability.

-Slump property The prepared composition 1 to composition 8 was confirmed according to the slump test method described in JIS A 1439 (test method for building sealant).

-Dischargeability after storage The prepared compositions 1 to 8 were placed in a sealable container and left in an oven at 70 ° C for 7 days. The composition 1 to the composition 8 which passed 70 degreeC / 7 days were confirmed with the said evaluation method of discharge property.

It was confirmed that by using fumed silica with a small amount of adhering water, a room temperature-curable organopolysiloxane composition excellent in appearance, slump property and storage stability was obtained (Composition 1, Composition 2).
When a curing agent (oxime silane) is mixed after the fumed silica, it is difficult to prepare the composition or the slump property deteriorates (Composition 3 to Composition 5).
When fumed silica with a large amount of adhering moisture is used, the result is a noticeable powderiness on the surface of the cured product, and the discharge properties after storage tend to be reduced (Composition 6 to Composition 8).

Claims (6)

(A) The following general formula (1)

(In the formula, each 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.)
Diorganopolysiloxane represented by
(B) The following general formula (2)

(Wherein R ² and R ³ are each independently an unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and a is 3 or 4.)
An organosilane compound represented by or a partially hydrolyzed condensate thereof,
(C) Untreated surface silica fine powder having an attached moisture content of less than 0.2% by mass;
(D) A method for producing a room temperature curable organopolysiloxane composition containing a curing catalyst, wherein (A) component and (B) component are mixed in advance to prepare a uniform mixture, and (C) The manufacturing method of the room temperature curable organopolysiloxane composition characterized by including the process of adding a component.   The condition for premixing the component (A) and the component (B) is a temperature range of 0 to 40 ° C and a mixing time of 5 to 60 minutes. Production method.   The method for producing a room temperature-curable organopolysiloxane composition according to claim 1 or 2, wherein the composition is produced using a flow jet mixer, a spiral mixer or a gate mixer.   The method for producing a room temperature-curable organopolysiloxane composition according to any one of claims 1 to 3, which is used for a sealing material for buildings.   The architectural sealing material obtained by the manufacturing method according to claim 4.   An article bonded and / or sealed with a cured product of the architectural sealant according to claim 5.