JP2014218558A - Room temperature curable polyorganosiloxane composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a room temperature curable polyorganosiloxane composition which has less deterioration in hardness of a hardened product under high temperature and high humidity, and good adhesiveness to various base materials.SOLUTION: A two-component room temperature curable polyorganosiloxane composition is composed of a main agent composition (A) and a hardener composition (B). The main agent composition (A) contains polyorganosiloxane having a resin structure represented by the average unit formula (c): (RSiO)[Si(OH)O], at a predetermined ratio. The hardener composition (B) contains: (d) a trifunctional or tetrafunctional silane compound, or partial hydrolysis condensate thereof; (e) a first amino group-containing silicon compound; and (f) a second amino group-containing silicon compound.

Description

  The present invention relates to a condensation reaction type polyorganosiloxane composition that cures at room temperature to produce a rubbery elastic body.

  For applications such as solar system parts, automotive parts, electrical / electronic equipment parts, adhesive / seal materials, potting materials, etc., a condensation reaction type that cures at room temperature by contact with moisture in the air and produces a rubbery elastic body These silicone rubber compositions are widely used.

  This condensation reaction type room temperature curable silicone rubber composition has a curing reaction caused by contact with moisture in the air. As a catalyst for promoting the curing reaction, an organic acid salt of a metal such as tin or a dialkyl Such as tin difatty acid salts, dialkyltin dialkoxides, dialkyltin oxides, titanium tetraalkoxides and partial hydrolysis products thereof, titanium chelate compounds, zirconium chelate compounds, aluminum trialkoxides and partial hydrolysis condensates thereof, and aluminum chelate compounds An organic compound having a metal atom is generally used. However, a composition using such an organic compound having a metal atom as a catalyst has a long curing time and a poor deep-curing property. Moreover, hydrolysis resistance was not sufficient.

  A room temperature curable silicone rubber composition has been proposed in which an amino group-containing silane compound is used as a catalyst in place of the above-described organic compound having a metal atom, thereby increasing the curing speed and improving the deep curability ( For example, see Patent Document 1 and Patent Document 2.)

  However, none of the compositions described in Patent Document 1 and Patent Document 2 has sufficient hydrolysis resistance of the cured product, and the hydrolysis of the rubber that is the cured product proceeds in a high temperature and high humidity atmosphere. Thus, there is a problem that physical properties such as hardness are remarkably deteriorated.

Japanese National Publication No. 07-020019 JP 2009-292914 A

  The present invention was made in order to solve such problems of the prior art, and good curing such that there is little decrease in hardness of the cured product in a high temperature / high humidity atmosphere or no decrease in hardness occurs. It is an object of the present invention to provide a room temperature curable polyorganosiloxane composition having excellent properties and excellent adhesion to various substrates.

The room temperature curable polyorganosiloxane composition of the present invention comprises:
(A) 100 parts by mass of a polyorganosiloxane whose molecular chain terminal is blocked with a hydroxyl group and whose viscosity at 23 ° C. is 0.1 to 100 Pa · s;
(B) 1 to 300 parts by weight of filler,
(C) Average unit formula: (R ¹ ₃ SiO _1/2 ) _p [Si (OH) _x O _{(4-x) / 2} ] _q (1)
(Wherein R ¹ is the same or different monovalent hydrocarbon group having 1 to 20 carbon atoms, x is 0.001 to 0.8, and p and q are both positive numbers). A main agent composition (A) containing 0.1 to 20 parts by mass of polyorganosiloxane represented by:
(D) the general _{^{formula: R 2 n Si (OR 3}} ) 4-n ... (2)
(In the formula, R ² is the same or different substituted or unsubstituted monovalent hydrocarbon group, R ³ is the same or different unsubstituted monovalent hydrocarbon group, and n is 0 or 1. 0.1 to 20 parts by mass of a trifunctional or tetrafunctional silane compound and / or a partially hydrolyzed condensate thereof,
(E) the general _{^{formula: (R 4 O) 3 Si}} -R 5 -NH-R 6 ... (3)
(Wherein R ⁴ is the same or different unsubstituted monovalent hydrocarbon group, R ⁵ is a substituted or unsubstituted divalent hydrocarbon group, and R ⁶ is a hydrogen atom, unsubstituted monovalent hydrocarbon group. 0.1 to 10 parts by mass of a first amino group-containing silicon compound represented by the following formula:
(F) the general _{^{formula: (R 7 O) 3-}} m R 8 m Si-R 9 -NH-R 9 -SiR 8 l (OR 7) 3-l ... (4)
(Wherein R ⁷ is the same or different unsubstituted monovalent hydrocarbon group, R ⁸ is the same or different substituted or unsubstituted monovalent hydrocarbon group, and R ⁹ is the same or different substituted or An unsubstituted divalent hydrocarbon group, m and l are integers of 0 to 2.) 0.1 to 10 parts by mass of a second amino group-containing silicon compound represented by A curing agent composition (B) substantially free of a curing catalyst having
A two-component composition comprising:

In this specification, R is a monovalent organic group, a monofunctional siloxy unit represented by the formula: R ₃ SiO _1/2 , and a bifunctional siloxy represented by the formula: R ₂ SiO _2/2 A unit, a trifunctional siloxy unit represented by the formula: RSiO _3/2 and a tetrafunctional siloxy unit represented by the formula: SiO _4/2 are respectively an abbreviation commonly used in the art, an M unit, D Unit, T unit, and Q unit may be indicated.
In this specification, a tetrafunctional siloxy unit represented by the formula: Si (OH) _x O _{(4-x) / 2} is referred to as a Q ^OH unit. Then, the polyorganosiloxane having the Q ^OH units, that polyorganosiloxanes having a resin structure (three-dimensional network structure).

  According to the room temperature curable polyorganosiloxane composition of the present invention, a cured product having good curability and sufficient hardness is obtained, and the cured product is excellent in hydrolysis resistance, and is also cured at high temperature and high humidity. There is little decrease in hardness or no decrease in hardness. The room temperature curable polyorganosiloxane composition of the present invention is also excellent in adhesiveness to various substrates.

Embodiments of the present invention will be described.
The room temperature curable polyorganosiloxane composition of the embodiment of the present invention is a two-component (two-component type) composition comprising a main agent composition (A) and a curing agent composition (B). The main agent composition (A) contains (a) a polyorganosiloxane whose molecular chain end is blocked with a hydroxyl group, (b) a filler, and (c) a polyorganosiloxane having a resin structure. Further, the curing agent composition (B) includes (d) a trifunctional or tetrafunctional silane compound or a partial hydrolysis condensate thereof, (e) a first amino group-containing silicon compound, and (f) Each of the two amino group-containing silicon compounds contains substantially no curing catalyst having a metal atom. At least one of the main agent composition (A) and the curing agent composition (B) may contain (g) a polyorganosiloxane having molecular chain terminals blocked with vinyl groups and / or methyl groups.
In addition, in the two-component room temperature curable polyorganosiloxane composition containing a curing catalyst having a metal atom, the curing catalyst having a metal atom is usually blended in the curing agent composition (B), and the main component composition (A ) Does not contain the curing catalyst. In the present invention, as described above, the curing agent composition (B) does not contain a curing catalyst having a metal atom, but the main agent composition (A) also does not contain this curing catalyst.
Hereinafter, each component which comprises the main ingredient composition (A) and hardening | curing agent composition (B) of this invention is demonstrated.

<(A) Terminal hydroxyl group-blocked polyorganosiloxane>
In the room temperature curable polyorganosiloxane composition of the embodiment, the polyorganosiloxane whose molecular chain terminal as the component (a) is blocked with a hydroxyl group is a main component of the main agent composition (A). It is a substantially linear polyorganosiloxane represented by the following general formula (5).

In the formula (5), a plurality of R ⁰ are substituted or unsubstituted monovalent hydrocarbon groups which may be the same as or different from each other. R ⁰ includes methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, octyl group, decyl group, alkyl group such as dodecyl group; cycloalkyl group such as cyclohexyl group; vinyl group, allyl group An alkenyl group such as a group; an aryl group such as a phenyl group, a tolyl group and a xylyl group; an aralkyl group such as a benzyl group, a 2-phenylethyl group and a 2-phenylpropyl group; and a hydrogen atom of these hydrocarbon groups A group in which a part of is substituted with another atom or group such as a halogen atom or a cyano group, for example, a halogenated alkyl such as chloromethyl group, 3-chloropropyl group, 3,3,3-trifluoropropyl group A group: a cyanoalkyl group such as a 3-cyanopropyl group, a halogenated aryl group such as a p-chlorophenyl group, and the like. It is easy to synthesize, has a low viscosity for its molecular weight, gives good extrudability to the composition before curing, and gives good physical properties to the composition after curing. It is preferable that 85% or more of these are methyl groups, and it is more preferable that substantially all organic groups are methyl groups.

On the other hand, in particular, when imparting heat resistance, radiation resistance, cold resistance or transparency, an aryl group as part of R ⁰ , and when imparting oil resistance and solvent resistance, as part of R ⁰ When a 3,3,3-trifluoropropyl group or 3-cyanopropyl group is used, or when the surface is provided with paintability, a long chain alkyl group or an aralkyl group is used in combination with a methyl group as part of R ^0. For example, it can be arbitrarily selected according to the purpose.

  Further, the polyorganosiloxane as the component (a) has a viscosity at 23 ° C. of 0.1 to 100 Pa · s. Therefore, n in the formula (5) is a number (integer) in which the viscosity of the polyorganosiloxane at 23 ° C. falls within the above range. If the viscosity of the component (a) at 23 ° C. is less than 0.1 Pa · s, the elongation of the cured product is insufficient, and conversely if it exceeds 100 Pa · s, workability such as dischargeability and flow characteristics are deteriorated. From the viewpoint of harmonizing physical properties required for the composition before and after curing, the more preferable viscosity of the component (a) is 0.5 to 50 Pa · s.

  As the component (a), one type of polyorganosiloxane having the above-mentioned viscosity in which both molecular chain ends are blocked with hydroxyl groups can be selected and used. Moreover, (a) component may mix 2 or more types of polyorganosiloxane from which a viscosity mutually differs, and may adjust the viscosity of the mixture in the said range (0.1-100 Pa.s). By using two or more polyorganosiloxanes having different viscosities in combination, there are advantages that adjustment to a desired viscosity is facilitated and the range of the viscosity of the usable polyorganosiloxane is widened.

<(B) Filler>
In the room temperature curable polyorganosiloxane composition of the embodiment, the filler as the component (b) serves to impart consistency to the room temperature curable composition and to impart mechanical strength to the cured product. Yes, blended into the main agent composition (A). (B) Examples of the filler include alkaline earth metal salts, inorganic oxides, metal hydroxides, and carbon black.

  Examples of the alkaline earth metal salt include calcium, magnesium, barium carbonate, bicarbonate and sulfate. Examples of the inorganic oxide include fumed silica, calcined silica, precipitated silica, quartz fine powder, titanium oxide (titania), iron oxide, zinc oxide, diatomaceous earth, and alumina. Examples of the metal hydroxide include aluminum hydroxide. Alternatively, the surface of these alkaline earth metal salts, inorganic oxides, and metal hydroxides treated with silanes, silazanes, low-polymerization siloxanes, or organic compounds may be used.

  (B) As the filler, use of calcium carbonate is preferred. The use of calcium carbonate can impart high fluidity to the composition before curing, and can impart high mechanical strength to the cured product. The particle size (average particle size) of the calcium carbonate used is preferably in the range of 0.005 to 10 μm. When the average particle size of calcium carbonate exceeds 10 μm, not only the mechanical properties of the cured product are deteriorated, but also the extensibility of the cured product is not sufficient. When the average particle size is less than 0.005 μm, the viscosity of the composition before curing increases and the fluidity decreases. The value of the average particle diameter may be a value measured by image analysis with an electron microscope, or may be obtained from an average particle diameter converted from a specific surface area, or a 50% diameter by weight conversion from a particle size distribution. Alternatively, the average particle diameter or an average particle diameter measured by a laser diffraction / scattering method may be used.

  In addition to (b) fillers having such an untreated surface, the surface of calcium carbonate is treated with fatty acids such as stearic acid and palmitic acid, resin (rosin) acid, ester compounds, silicic acid compounds. What was processed by etc. may be used. When calcium carbonate surface-treated with the fatty acid or the like is used, the dispersibility of calcium carbonate is improved, so that the processability of the composition is improved. As the surface treatment agent, use of stearic acid or rosin acid is preferable.

  (B) The compounding quantity of a filler is 1-300 mass parts with respect to 100 mass parts of said (a) component, Preferably it is 5-100 mass parts. If the amount is less than 1 part by mass, sufficient effects such as reinforcement by blending cannot be obtained. If the amount exceeds 300 parts by mass, workability such as dischargeability and flow characteristics are deteriorated.

<(C) Polyorganosiloxane having a resin structure>
In the embodiment, (c) average unit formula contained in the main agent composition (A): (R ¹ ₃ SiO _1/2 ) _p [Si (OH) _x O _{(4-x) / 2} ] _q (1) It is considered that the polyorganosiloxane having a resin structure (three-dimensional network structure) represented by the formula (ii) functions to improve the hydrolysis resistance of the cured product.

In Formula (1), R ¹ is a monovalent hydrocarbon group having 1 to 20 carbon atoms which may be the same or different from each other. Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms include an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, a decyl group, and a dodecyl group; A cycloalkyl group such as a group; an alkenyl group such as a vinyl group or an allyl group; an aryl group such as a phenyl group, a tolyl group or a xylyl group; a benzyl group, a 2-phenylethyl group or a 2-phenylpropyl group; Aralkyl group and the like can be mentioned. Preferably they are an alkyl group, an alkenyl group, and an aryl group, More preferably, they are a methyl group, a vinyl group, and a phenyl group.

  Moreover, both p and q are positive numbers. Since the values of p and q are calculated based on the weight average molecular weight and p / q described later, if the weight average molecular weight and p / q are limited, it is not necessary to limit p and q individually. , P is preferably 10 to 50, and q is preferably 10 to 50.

In the polyorganosiloxane having a resin structure as the component (c), from the viewpoint of stability, the M unit represented by the formula: (R ¹ ₃ SiO _1/2 ) and the formula: [Si (OH ) _X O _{(4-x) / 2} ] The molar ratio (value of p / q) with the Q ^OH unit is preferably 0.4 to 1.2. When p / q is less than 0.4, the solubility of the component (c) becomes insufficient, and as a result, the stability of the main agent composition (A) becomes insufficient. When p / q exceeds 1.2, since the crosslinking in the component (c) is insufficient, a cured product having sufficient stability against hydrolysis cannot be obtained.

Moreover, x, which is an average value of the number of hydroxyl groups (OH) in the Q ^OH unit, is preferably 0.001 to 0.8. And in polyorganosiloxane which has the resin structure (three-dimensional network structure) which is (c) component, it is preferable that content of a hydroxyl group is 0.01-10 mass% with respect to the whole (c) component. Since the hydroxyl group reacts with the alkoxy group to crosslink, if the content ratio of the hydroxyl group is too high, the cured product tends to be brittle. When the content ratio of the hydroxyl group is too low, the cured product is easily softened over a long period of time.

  Further, the weight average molecular weight (Mw) of the component (c) is preferably in the range of 500 to 20000, more preferably in the range of 500 to 10,000. In addition, this weight average molecular weight (Mw) is calculated | required by GPC (gel permeation chromatograph) on the basis of polystyrene.

  As a method for producing the polyorganosiloxane having a resin structure as the component (c), a known method may be used. The method described in USP 3,205,283 can also be used. For example, after combining the compound used as each unit source in the ratio mentioned above, the method of cohydrolyzing in presence of an acid and an alkali, and condensing subsequently is mentioned.

  (C) The compounding quantity of a component is 0.1-20 mass parts with respect to 100 mass parts of said (a) component, Preferably it is 5-15 mass parts. If it is less than 0.1 mass part, the effect which improves the fall of the hardness under high temperature and high humidity of hardened | cured material cannot fully be acquired. When it exceeds 20 mass parts, physical properties, such as elasticity of hardened | cured material, will fall.

<(D) Silane compound or partially hydrolyzed condensate thereof>
In the room temperature curable polyorganosiloxane composition of the embodiment, (d) the silane compound or a partial hydrolysis condensate thereof blended in the curing agent composition (B) has the formula: R ² _n Si (OR ³ ) _{4− n} is a trifunctional or tetrafunctional silane compound represented by (2) or a partial hydrolysis-condensation product thereof, and acts as a crosslinking agent for the components (a) and (c).

In formula (2), R ² is a substituted or unsubstituted monovalent hydrocarbon group which may be the same or different from each other. Examples thereof are the same groups as R ⁰ in formula (5) representing the component (a). All the above statements regarding R ⁰ also apply to R ² . R ³ is an unsubstituted monovalent hydrocarbon group which may be the same or different from each other. Examples of R ³ include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, octyl group, decyl group, and dodecyl group. R ² and R ³ are preferably a methyl group, an ethyl group, or a propyl group. n is 0 or 1.

  Such a trifunctional silane compound or a partial hydrolysis-condensation product of a tetrafunctional silane compound preferably has 3 to 20 Si atoms, more preferably 4 to 15 molecules. If the number of Si is less than 3, sufficient curability cannot be obtained. Moreover, when Si number exceeds 20, sclerosis | hardenability and the mechanical characteristic after hardening will fall. (D) The silane compound which is a component, or its partial hydrolysis-condensation product may be used individually by 1 type, and may be used in mixture of 2 or more types.

  (D) The compounding quantity of a component is 0.1-20 mass parts with respect to 100 mass parts of (a) component of the said main ingredient composition (A), Preferably it is 1-5 mass parts. If the amount is less than 0.1 part by mass, crosslinking is not sufficiently performed and not only a cured product having low hardness is obtained, but also the storage stability of the composition containing the crosslinking agent becomes poor. If it exceeds 20 parts by mass, the shrinkage rate during curing increases, and the physical properties such as elasticity of the cured product decrease.

<(E) First amino group-containing silicon compound>
In the room temperature curable polyorganosiloxane composition of the embodiment, (e) the first amino group-containing silicon compound blended in the curing agent composition (B) has the formula: (R ⁴ O) ₃ Si—R ⁵ — NH-R ⁶ ... is an amino-functional alkoxysilane represented by (3), and functions to improve the adhesion of the composition. Also, the alkoxy group of component (e) reacts with the hydroxyl groups of component (a) and component (c) to form a crosslinked structure.

In the formula (3) representing the first amino group-containing silicon compound as the component (e), R ⁴ is an unsubstituted monovalent hydrocarbon group which may be the same or different, and is described above. (d) the same group as R ³ of component is exemplified. All the above statements regarding R ³ also apply to R ⁴ . R ⁵ is a substituted or unsubstituted divalent hydrocarbon group which may be the same or different, for example, methylene group, ethylene group, propylene group, tetramethylene group, hexamethylene group, methylethylene group An alkylene group such as a phenylene group or a tolylene group; an alkylene arylene group such as a methylenephenylene group or an ethylenephenylene group; Among these hydrocarbon groups, alkylene groups such as a propylene group, a tetramethylene group, a hexamethylene group, and a methylethylene group are preferable. The reason is that an arylene group such as a phenylene group or a tolylene group, or an alkylene arylene group such as a methylenephenylene group or an ethylenephenylene group exists between an amino group (—NH—) and an alkoxyl group bonded to a silicon atom. This is because the reactivity of the alkoxyl group is lowered, and the adhesiveness may be lowered.

R ⁶ represents a hydrogen atom, an unsubstituted monovalent hydrocarbon group or an aminoalkyl group. Examples of the unsubstituted monovalent hydrocarbon group include alkyl groups such as a methyl group, an ethyl group, a propyl group, and a butyl group. Examples of aminoalkyl groups include aminoethyl groups and N-aminoethylaminoethyl groups.

…………（３１）

…………（３２）

…………（３３） Specific examples of the (e) first amino group-containing silicon compound include γ-aminopropyltriethoxysilane represented by the following formula (31) and γ-aminopropyltriethoxy represented by the formula (32). Examples thereof include methoxysilane and N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane represented by the formula (33).

………… (31)

………… (32)

………… (33)

<(F) Second amino group-containing silicon compound>
In the room temperature curable polyorganosiloxane composition of the embodiment, (f) the second amino group-containing silicon compound blended in the curing agent composition (B) has the formula: (R ⁷ O) _3-m R ⁸ _m amino functional alkoxy silane represented by _{^{Si-R 9 -NH-R 9}} -SiR 8 l (OR 7) 3-l ... (4). Similar to the component (e), the alkoxy group of the component (f) reacts with the hydroxyl groups of the components (a) and (c) to form a crosslinked structure. The component (f) also functions to improve the adhesiveness of the composition.

(F) In the formula (4) representing the second amino group-containing silicon compound, R ⁷ may be the same or different and is an unsubstituted monovalent hydrocarbon group, Examples of the group similar to R ⁴ in 1 amino group-containing silicon compound are given. All of the above statements regarding R ⁴ also apply to R ⁷ . R ⁸ is a substituted or unsubstituted monovalent hydrocarbon group which may be the same as or different from each other, and examples thereof include the same groups as R ^{2 in the} component (d) described above. All of the above statements regarding R ² also apply to R ⁸ . R ⁹ is a substituted or unsubstituted divalent hydrocarbon group which may be the same or different, and examples thereof include the same groups as R ⁵ in the above (e). All the above statements regarding R ⁵ also apply to R ⁹ . Furthermore, m and l are integers of 0-2.

…………（４１） Specific examples of the (f) second amino group-containing silicon compound include bis- (γ-trimethoxysilylpropyl) amine represented by the following formula (41) and bis- (γ-triethoxysilyl). Propyl) amine and the like.

………… (41)

  Such (f) second amino group-containing silicon compound and (e) first amino group-containing silicon compound may be used alone or in combination of two or more. May be used. (E) The compounding amount of the first amino group-containing silicon compound and (f) the compounding amount of the second amino group-containing silicon compound are both 0.1 to 100 parts by mass of the component (a). 10 parts by mass, more preferably 0.5 to 5 parts by mass. When the blending amount of at least one of (e) the first amino group-containing silicon compound and (f) the second amino group-containing silicon compound is less than 0.1 parts by mass, curing is difficult to develop and adhesion is also exhibited. Not enough. On the other hand, when the blending amount of at least one of these is more than 20 parts by mass, it may cause a decrease in mechanical strength, a decrease in adhesion reliability and a decrease in heat resistance.

  Further, the blending amounts of (e) the first amino group-containing silicon compound and (f) the second amino group-containing silicon compound are preferably adjusted as shown below from the viewpoints of adhesiveness, curability and the like. . That is, in the room temperature curable polyorganosiloxane composition of the present invention, the total amount of alkoxy groups bonded to silicon atoms in the component (e) and the component (f), the component (a) and the component (c) It is preferable to adjust the molar ratio (alkoxy group / OH group) to the total amount of hydroxyl groups bonded to silicon atoms in the range of 5 to 50. The alkoxy group / OH group is more preferably 10-30, and particularly preferably 15-25.

<(G) Capped polyorganosiloxane such as terminal methyl group>
In the main agent composition (A), in order to adjust the viscosity of the main agent composition (A) and the finally obtained room temperature-curable polyorganosiloxane, and to facilitate the blending of the filler (b), (G) It is preferable to blend a polyorganosiloxane whose molecular chain ends are blocked with vinyl groups and / or methyl groups (hereinafter referred to as blocked polyorganosiloxanes such as terminal methyl groups). (G) The terminal methyl group-capped polyorganosiloxane is a linear polydimethylsiloxane in which both molecular chain ends are blocked with trimethylsilyl groups, or a linear chain in which both molecular chain ends are blocked with vinyldimethylsilyl groups. Examples thereof include polydimethylsiloxane.

  Moreover, while controlling the viscosity of a hardening | curing agent composition (B), in order to adjust the compounding ratio of the hardening | curing agent composition (B) with respect to a main ingredient composition (A) to a desired value, (g) terminal methyl mentioned above. Group-capped polyorganosiloxane can be blended in the curing agent composition (B). As the component (h), as in the case of the component (d), linear polydimethylsiloxane in which both ends of the molecular chain are blocked with trimethylsilyl groups, or straight chain in which both ends of the molecular chain are blocked with vinyldimethylsilyl groups are used. Examples include chain polydimethylsiloxane.

  The viscosity at 23 ° C. of the terminal methyl group-capped polyorganosiloxane as component (g) is preferably 0.1 to 100 Pa · s. In particular, the viscosity is preferably lower than the viscosity of the component (a) so that the viscosity of the main agent composition (A) can be easily adjusted.

(G) When mix | blending the amount of a component with a main ingredient composition (A), it adjusts so that a main ingredient composition (A) and the room temperature curable polyorganosiloxane finally obtained may become a desired viscosity. . (A) 0.1-100 mass parts is preferable with respect to 100 mass parts of components, More preferably, you may be 5-30 mass parts.
(G) When mix | blending a component with a hardening | curing agent composition (B), the compounding quantity adjusts so that a hardening agent composition (B) and the room temperature curable polyorganosiloxane finally obtained may become a desired viscosity. (A) 0.1-100 mass parts is preferable with respect to 100 mass parts of component, More preferably, you may be 1-20 mass parts.

<Other ingredients>
The room temperature curable polyorganosiloxane composition of the present invention exhibits excellent adhesion to various substrates, but a known adhesion improver can be blended in order to further improve the adhesion. Examples of the adhesion improver used include isocyanuric ring-containing silicon compounds such as 1,3,5-tris (3-trimethoxysilylpropyl) isocyanurate, 3-glycidoxypropyltrimethoxysilane, and 3-glycidoxypropyl. An epoxy group-containing silane such as methyldimethoxysilane is exemplified.

  Such an adhesion improver is preferably added to the curing agent composition (B). 0.1-10 mass parts is preferable with respect to 100 mass parts of said (a) component, and, as for the compounding quantity of an adhesive improvement agent, 0.5-5 mass parts is more preferable.

  In the room temperature curable polyorganosiloxane composition of the embodiment, an additive generally blended in this type of composition may be blended as necessary within a range not inhibiting the effects of the present invention. it can. Examples of such additives include pigments, dyes, thixotropic agents, ultraviolet absorbers, fungicides, and heat resistance improvers. These additives may be blended in the main agent composition (A), in the curing agent composition (B), or in the main agent composition (A) and the curing agent composition (B). You may mix | blend with both. However, the room temperature curable polyorganosiloxane composition of the present invention functions as a curing catalyst for promoting curing based on the crosslinking reaction of the component (a) and the component (c), and contains metal atoms as exemplified below. It does not contain organic compounds substantially.

  Metal atom-containing organic compounds that function as curing catalysts include carboxylic acid metal salts such as iron octoate, manganese octoate, zinc octoate, tin naphthate, tin caprylate, tin oleate; dibutyltin diacetate, dibutyltin dioctoate, dibutyltin dilaurate, Organotin compounds such as dibutyltin dioleate, diphenyltin diacetate, dibutyltin oxide, dibutyltin dimethoxide, dibutylbis (triethoxysiloxy) tin, dioctyltin dilaurate; tetraethoxytitanium, tetrapropoxytitanium, tetrabutoxytitanium, 1,3- Alkoxytitaniums such as propoxytitanium bis (ethylacetylacetate); aluminum trisacetylacetonate, aluminum triseth Organoaluminum such as acetoacetate, diisopropoxyaluminum ethyl acetoacetate, triethoxyaluminum; such as zirconium tetraacetylacetonate, tetraisopropoxyzirconium, tetrabutoxyzirconium, tributoxyzirconium acetylacetonate, tributoxyzirconium stearate There are organic zirconium compounds and the like, and neither the main agent composition (A) nor the curing agent composition (B) of the present invention contains such an organic compound containing a metal atom.

  The room temperature-curable polyorganosiloxane composition of the present invention is essential for (a) a polyorganosiloxane whose molecular chain end is blocked with a hydroxyl group, (b) a filler, and (c) a polyorganosiloxane having a resin structure. And (g) a main component composition (A) containing a blocked polyorganosiloxane such as a terminal methyl group, and (d) a trifunctional or tetrafunctional silane compound or a partially hydrolyzed condensate thereof. And (e) a first amino group-containing silicon compound and (f) a second amino group-containing silicon compound as essential components, and (g) a blocked polyorganosiloxane such as a terminal methyl group, if necessary. And a hardener composition (B) containing a metal atom and not containing an organic compound (curing catalyst). The main agent composition (A) and the curing agent composition (B) are stored separately in separate containers and are cured by mixing them during use and exposing them to moisture in the air. Used in the form of a two-component composition.

The room temperature curable polyorganosiloxane composition of the present invention is stable under sealed conditions in the absence of moisture, and is cured at room temperature upon contact with moisture in the air to produce a rubbery elastic body. In particular, a composition having a high curing rate and excellent deep part curability and excellent adhesion to various substrates can be obtained. And the hydrolysis resistance of hardened | cured material is favorable, and it has the outstanding characteristics that there is little fall of the hardness of hardened | cured material at high temperature and high humidity atmosphere, or the hardness of hardened | cured material hardly falls.
Therefore, the composition of the present invention is useful as an elastic adhesive, coating material, potting material, etc. for solar parts, automobile parts, parts for electric and electronic devices, and also as a field forming gasket, a sealing material for construction, etc. Useful.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples. In Examples and Comparative Examples, “part” means “part by mass”, and all physical properties such as viscosity are values at 23 ° C. and 50% relative humidity.

Example 1
First, a polyorganosiloxane composed of M units and Q ^OH units (hereinafter referred to as MQ ^OH resin) was produced as follows.

[(C) Production of MQ ^OH resin]
100 parts of trimethylchlorosilane and 200 parts of sodium silicate were put into a mixed solvent of water, IPA (isopropyl alcohol) and xylene, and hydrolysis and subsequent condensation were performed in this mixed solvent. After stirring at 80 ° C. or lower for 2 hours, the aqueous phase and the oil phase were separated to obtain a xylene solution of MQ ^OH resin as the oil phase.
The obtained MQ ^OH resin has a molar ratio (M / Q ^OH ) of M units to Q ^OH units of 0.9, a weight average molecular weight (Mw) of 3000, and a hydroxyl group content of 0.2 mass. %.

(A1) Both ends of the molecular chain were blocked with 100.0 parts of polydimethylsiloxane (viscosity: 10 Pa · s, hydroxyl amount: 0.04 mmol / g) blocked at both ends of the molecular chain with a trimethylsilyl group. 10.0 parts of polydimethylsiloxane (viscosity 0.1 Pa · s) and 10.0 parts (solid content) of the (c) MQ ^OH resin obtained above were mixed, and reduced pressure at 140 ° C. to 2 mmHg. After removing the solvent in (b1), 80.0 parts of calcium carbonate surface-treated with stearic acid was added and mixed with a planetary mixer for 2 hours to obtain 200.0 parts of a main agent composition.

In addition, (g2) 9.4 parts of polydimethylsiloxane (viscosity 3.0 Pa · s) blocked at both ends of the molecular chain with vinylmethylsilyl groups, 3.1 parts of carbon black, (d) Formula: Si (OC ₂ H ₅ ) 2.0 part of a partially hydrolyzed condensate of the silane compound represented by ₄ (polyethyl silicate: Si number 7) and (e2) N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane 1.4 parts of (f) 1.4 parts of (f) bis (γ-trimethoxysilylpropyl) amine and 0.7 parts of 1,3,5-tris (3-trimethoxysilylpropyl) isocyanurate Was mixed for 20 minutes to obtain 18.0 parts of a curing agent composition. Next, 200.0 parts of the main agent composition and 18.0 parts of the curing agent composition were uniformly mixed using a static mixer to obtain a polyorganosiloxane composition.

Examples 2-3 and Comparative Examples 1-3
Each component shown as the main agent composition in Tables 1 and 2 was blended in the composition shown in the same table and mixed in the same manner as in Example 1 to obtain the main agent composition having the total number of parts shown in the same table. Moreover, each component shown as a hardening | curing agent composition to Tables 1-2 was mix | blended with the composition shown to the same table, it mixed similarly to Example 1, and the hardening agent composition of the number of parts shown in the same table was obtained in total. . Next, the main component composition and the curing agent composition thus obtained were uniformly mixed to obtain a room temperature-curable polyorganosiloxane composition.

  Among the components shown in Tables 1 and 2, (a2) hydroxyl-blocked polydimethylsiloxane is a poly (dimethylsiloxane) having a viscosity of 1 Pa · s and a hydroxyl group amount of 0.08 mmol / g. Dimethylsiloxane was used.

  Next, with respect to the polyorganosiloxane compositions obtained in Examples 1 to 3 and Comparative Examples 1 to 3, the hardness of the cured product (initial and hardness after standing in a high-temperature and high-humidity atmosphere) by the method shown below. And the adhesion was measured and evaluated. The results are shown in the lower column of Tables 1-2.

[Hardness]
The obtained polyorganosiloxane composition was dispensed and formed into a 6 mm block shape, and then allowed to cure for 3 days in an atmosphere of 23 ° C. and 50% RH. The hardness (initial hardness) of the cured product thus obtained was measured with a type A hardness meter.

[Hardness after standing in high temperature and high humidity atmosphere]
A cured product obtained by curing in an atmosphere of 23 ° C. and 50% RH was left in an atmosphere of 80 ° C. and 80% RH for 30 days, and then the hardness of the cured product was measured with a type A hardness meter. And the change from initial hardness was calculated | required.

[Adhesiveness]
A polyorganosiloxane composition was applied to the surface of various substrates (aluminum, glass, and epoxy glass) so as to have a length of 50 mm, a width of 10 mm, and a thickness of 1 mm, in an atmosphere of 23 ° C. and 50% RH. It was left to cure for 3 days. Thereafter, the cured product was scraped off from the substrate surface with a metal spatula, and the state of peeling of the cured product at this time was examined. And the adhesiveness was evaluated according to the following criteria.
Adhesiveness (circle): Hardened | cured material cannot be peeled from the interface with a base material, but hardened | cured material destroys.
Adhesiveness Δ: A part of the cured product is peeled off from the interface with the substrate, and a part of the cured product is destroyed.
Adhesiveness x: The cured product can be peeled off from the interface with the substrate.

  As can be seen from Tables 1 and 2, the main agent composition (A) in which the components (a) to (c) are blended at a predetermined ratio, and the components (d) to (f) at a predetermined ratio. The polyorganosiloxane compositions of Examples 1 to 3 obtained by mixing the blended cured composition (B) are excellent in curability, the cured product has sufficient hardness, and the cured product is Even when left in a high-temperature and high-humidity atmosphere, there is little decrease in hardness. Moreover, the polyorganosiloxane composition of Examples 1-3 has favorable adhesiveness with respect to various base materials like metal, glass, and epoxy glass.

On the other hand, the polyorganosiloxane compositions obtained in Comparative Examples 1 to 3 are not blended with the component (c) MQ ^OH resin, so that not only the initial hardness of the cured product is low, Hardness of the cured product is greatly reduced in high temperature and high humidity atmosphere.

According to the room temperature curable polyorganosiloxane composition of the present invention, it is possible to obtain a cured product having a sufficient hardness and a small decrease in hardness in a high temperature and high humidity atmosphere. Moreover, the hardened | cured material excellent in the adhesiveness with respect to various base materials can be obtained.
Therefore, the composition of the present invention is useful as an elastic adhesive for solar parts, automobile parts, electric / electronic devices, coating materials, potting materials, etc., and also useful as an on-site forming gasket, architectural sealing material, etc. It is.

Claims (7)

(A) 100 parts by mass of a polyorganosiloxane whose molecular chain terminal is blocked with a hydroxyl group and whose viscosity at 23 ° C. is 0.1 to 100 Pa · s;
(B) 1 to 300 parts by weight of filler,
(C) Average unit formula: (R ¹ ₃ SiO _1/2 ) _p [Si (OH) _x O _{(4-x) / 2} ] _q (1)
(Wherein R ¹ is the same or different monovalent hydrocarbon group having 1 to 20 carbon atoms, x is 0.001 to 0.8, and p and q are both positive numbers). A main agent composition (A) containing 0.1 to 20 parts by mass of polyorganosiloxane represented by:
(D) the general _{^{formula: R 2 n Si (OR 3}} ) 4-n ... (2)
(In the formula, R ² is the same or different substituted or unsubstituted monovalent hydrocarbon group, R ³ is the same or different unsubstituted monovalent hydrocarbon group, and n is 0 or 1. 0.1 to 20 parts by mass of a trifunctional or tetrafunctional silane compound and / or a partially hydrolyzed condensate thereof,
(E) the general _{^{formula: (R 4 O) 3 Si}} -R 5 -NH-R 6 ... (3)
(Wherein R ⁴ is the same or different unsubstituted monovalent hydrocarbon group, R ⁵ is a substituted or unsubstituted divalent hydrocarbon group, and R ⁶ is a hydrogen atom, unsubstituted monovalent hydrocarbon group. 0.1 to 10 parts by mass of a first amino group-containing silicon compound represented by the following formula:
(F) the general _{^{formula: (R 7 O) 3-}} m R 8 m Si-R 9 -NH-R 9 -SiR 8 l (OR 7) 3-l ... (4)
(Wherein R ⁷ is the same or different unsubstituted monovalent hydrocarbon group, R ⁸ is the same or different substituted or unsubstituted monovalent hydrocarbon group, and R ⁹ is the same or different substituted or An unsubstituted divalent hydrocarbon group, m and l are integers of 0 to 2.) 0.1 to 10 parts by mass of a second amino group-containing silicon compound represented by A curing agent composition (B) substantially free of a curing catalyst having
A room temperature-curable polyorganosiloxane composition, characterized in that it is a two-component composition comprising:   At least one of the main agent composition (A) and the curing agent composition (B) is (g) having a molecular chain terminal blocked with a vinyl group and / or a methyl group, and a viscosity at 23 ° C. of 0.1 to 100 Pa. The room temperature-curable polyorganosiloxane composition according to claim 1, further comprising 0.1 to 100 parts by mass of polyorganosiloxane which is s.   The room temperature-curable polyorganosiloxane according to claim 1 or 2, wherein the component (a) is a mixture of polydiorganosiloxanes having both ends of molecular chains having different viscosities blocked with hydroxyl groups. Composition. In the polyorganosiloxane which is the component (c), the molar ratio (p / q) between the (R ¹ ₃ SiO _1/2 ) unit and the [Si (OH) _x O _{(4-x) / 2} ] unit. The room temperature-curable polyorganosiloxane according to any one of claims 1 to 3, wherein 0.4 to 1.2 and the hydroxyl group content is 0.01 to 10% by mass. Composition.   The room temperature-curable polyorganosiloxane composition according to any one of claims 1 to 4, wherein the polyorganosiloxane as the component (c) has a weight average molecular weight (Mw) of 500 to 20,000. object.   The room temperature curable polyorganosiloxane composition according to any one of claims 1 to 5, wherein the filler as the component (b) contains calcium carbonate surface-treated with stearic acid or rosin acid. .   The total amount of alkoxy groups bonded to silicon atoms in the component (d), the component (e) and the component (f), and the silicon atoms in the component (a) and the component (c) The room temperature-curable polyorganosiloxane composition according to any one of claims 1 to 6, wherein the molar ratio (alkoxy group / OH group) to the total amount of hydroxyl groups is 2 to 50.