JP4954785B2 - Room temperature curable polyorganosiloxane composition - Google Patents

Description

  The present invention relates to a room temperature curable polyorganosiloxane composition, and more particularly, a polyorganosiloxane composition capable of obtaining a cured product having relatively low hardness, excellent elasticity, high extensibility and excellent flame retardancy. About.

  Among polyorganosiloxane compositions that cure at room temperature to form a rubbery elastic body, a room temperature curable polyorganosiloxane composition in which a curing reaction occurs by contact with moisture in the air is a main body immediately before use. There is no need to weigh or mix base polymers, cross-linking agents, catalysts, etc. It is widely used as an agent and coating material, and as a building sealing material.

  Among such room temperature curable polyorganosiloxane compositions, an amino group-containing silane (amino functional group) is mainly used to provide self-adhesiveness, mainly composed of polyorganosiloxane having alkoxy groups bonded to terminal silicon atoms. A composition containing silane is used as an adhesive, a coating material, and a sealing material (see, for example, Patent Document 1, Patent Document 2, Patent Document 3, Patent Document 4, and Patent Document 5).

  However, when a room temperature-curable polyorganosiloxane composition containing a normal amino group-containing silane is used as an adhesion improver, the hardness of the cured product is increased, and a metal oxide such as a metal oxide is used to obtain flame retardancy. Even when a large amount of the inorganic filler is blended, the hardness of the resulting composition becomes too high. Therefore, there is a problem that the hardness is relatively low and it is difficult to obtain an elastic composition.

  Conventionally, a polyorganosiloxane composition that causes a dehydroxylamine-type curing reaction has been used as a sealant having a low modulus and high extensibility, but since this composition does not have self-adhesive properties, a primer, etc. It was necessary to pre-process the member using the material, and there was a problem that the construction work became complicated. There is also concern about the effects of the organic solvent contained in the primer on the health and environment of workers.

  More recently, room temperature curable polyorganosiloxane compositions that cure only by contact with moisture in the air are expected to increase in demand from the viewpoint of energy saving, and are also subject to electron beam and ultraviolet light irradiation and heating. It is actively used for a wide range of use sites, such as building structures and existing installations. In view of the safety of the building structure and the place where it is used, there is an increasing demand for flame retardancy in such room temperature curable polyorganosiloxane compositions.

However, the present situation is that a room temperature curable polyorganosiloxane composition having self-adhesiveness, relatively low hardness, excellent elasticity, good flame retardancy and high extensibility has not been obtained.
Japanese Examined Patent Publication No. 46-11272 JP-A-50-71743 JP-A-53-102956 Japanese Patent Application Laid-Open No. 60-60160 Japanese Patent Publication No. 63-23226

  The present invention has been made to solve these problems, and is a room temperature curable polyorgano capable of obtaining a cured product having appropriate hardness, excellent elasticity, high extensibility and excellent flame retardancy. An object is to provide a siloxane composition.

The room temperature curable polyorganosiloxane composition of the present invention comprises (A) a polyorganosiloxane 100 having molecular chain terminals blocked with hydroxyl groups or hydrolyzable groups and having a viscosity at 23 ° C. of 20 to 1,000,000 mPa · s. Parts by weight,
(B) 0.5 to 20 parts by weight of a silane having a ketoximato group having an average number of more than 2 as a silicon functional group in the molecule or a partial hydrolyzate thereof ,
(C) 1 to 400 parts by weight of an inorganic filler,
(D) the general ^{_{formula: (R 1 O) 3-}} m R 2 m Si-R 3 ......... (1)
(In the formula, R ¹ and R ² represent the same or different alkyl groups. M is an integer of 0 to 2. Also, R ³ represents a general formula: — (CH ₂ ) _p —CHR ⁴ — (CH _{2) q} -NH ₂ or the formula ^{_{:-( CH 2) p -C (R}} 4) 2 - (CH 2) q -NH 2
The amino group substituted alkyl group which has the branch represented by these is shown. Here, R ⁴ represents an alkyl group having 1 to ⁴ carbon atoms, and p and q are each an integer of 1 to 8. However, p + q is an integer of 9 or less. 0.05 to 15 parts by weight of an alkoxysilane having an amino group-substituted alkyl group represented by :
(E) curing catalyst 0.001 to 10 parts by weight , and
The flame retardant additive is characterized by containing (F) a platinum compound or a complex compound thereof .

  According to the room temperature curable polyorganosiloxane composition of the present invention, it is possible to obtain a cured product having excellent curability, moderate hardness, high extensibility and excellent flame retardancy.

  Embodiments of the present invention will be described below.

  The room temperature curable polyorganosiloxane composition of the embodiment of the present invention comprises (A) 100 parts by weight of a polyorganosiloxane in which the molecular chain terminal is blocked with a hydroxyl group (hydroxyl group) or a hydrolyzable group, and (B) in the molecule. 0.5 to 20 parts by weight of a silicon compound having an average of more than two ketoximato groups as silicon functional groups, (C) 1 to 400 parts by weight of an inorganic filler, and (D) an amino group-substituted alkyl group It contains 0.05 to 15 parts by weight of alkoxysilane and 0.001 to 10 parts by weight of (E) curing catalyst.

  The component (A) is a polyorganosiloxane whose molecular chain end is blocked with a hydroxyl group (hydroxyl group) or a hydrolyzable group, and is a main component of the room temperature curable composition of the embodiment. If the viscosity of the component (A) is too low, the rubber elasticity after curing will be poor, and if it is too high, the workability will be reduced. Therefore, the viscosity at 23 ° C. is 20 to 1,000,000 mPa · s, more preferably 100. It is preferable to be in the range of ~ 100,000 mPa · s.

The molecular structure of the polyorganosiloxane is preferably a straight chain represented by the following general formula (2), but may have a partially branched structure.

Wherein (2), ^{R 5} represents a monovalent hydrocarbon group which may substituted or unsubstituted be the same or different, monovalent organic ^{R 6} is represented by -ZSiR ⁷ _{3-r X} r Represents a group. Here, Z represents oxygen (oxo group) or a divalent hydrocarbon group, and R ⁷ represents a substituted or unsubstituted monovalent hydrocarbon group which may be the same as or different from each other. X represents a hydroxyl group (hydroxyl group) or a hydrolyzable group, and r is an integer of 1 to 3. Moreover, n is a number which makes the viscosity (23 degreeC) of the said (A) component 20-1,000,000 mPa * s.

R ⁵ includes methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, octyl group, decyl group, alkyl group such as dodecyl group; alkenyl group such as vinyl group and allyl group; phenyl group And aryl groups such as tolyl group and xylyl group; aralkyl groups such as 2-phenylethyl group and 2-phenylpropyl group are exemplified, and some of the hydrogen atoms of these hydrocarbon groups are other atoms or groups. Substituted with, i.e., halogenated alkyl groups such as chloromethyl, 3-chloropropyl, 3,3,3-trifluoropropyl; substituted carbons such as cyanoalkyl such as 3-cyanopropyl A hydrogen group is illustrated. It is easy to synthesize, and the component (A) has a low viscosity with respect to the molecular weight, gives good extrudability to the composition before curing, and gives good physical properties to the composition after curing. it from is preferably 85% or more of the total R ⁵ is a methyl group, and more preferably substantially all R ⁵ is a methyl group.

On the other hand, particularly when imparting heat resistance, radiation resistance, cold resistance or transparency to the composition, a necessary amount of phenyl groups as part of R ⁵ , when imparting oil resistance and solvent resistance, When a 3,3,3-trifluoropropyl group or 3-cyanopropyl group is provided as a part of R ⁵ , or a surface having paintability is provided, a long chain alkyl group or aralkyl is provided as a part of R ^5. The group can be arbitrarily selected depending on the purpose, for example, in combination with a methyl group. In order to improve the extensibility by keeping the viscosity of the composition low, it is better not to include a phenyl group as R ⁵ .

(A) end groups of component ^{R 6 is} represented by _{-ZSiR 7 3-r X} r, hydroxyl is a silicon functional group (hydroxyl group) or a hydrolyzable group X in the silicon-functional siloxy units having at least one is there. Therefore, the component (A) of the embodiment has at least one hydroxyl group (hydroxyl group) or hydrolyzable group X at both ends of the molecule.

In the terminal group R ⁶ , R ⁷ bonded to the silicon atom is a substituted or unsubstituted monovalent hydrocarbon group which may be the same as or different from each other and may be the same as or different from R ^5. Materials similar to those in the R ⁵ can be exemplified. A methyl group or a vinyl group is preferable because synthesis is easy and the reactivity of the hydrolyzable group X is excellent. Z is a divalent oxygen (oxy group) or a divalent hydrocarbon group which may be the same or different from each other. Examples of the divalent hydrocarbon group include alkylene such as a methylene group, an ethylene group and a trimethylene group. Group; a phenylene group and the like are exemplified. From the viewpoint of easy synthesis, an oxy group or an ethylene group is preferable, and an oxy group is particularly preferable.

X is a hydroxyl group (hydroxyl group) or a hydrolyzable group that is a silicon functional group present in at least one of R ⁶ that is a terminal group. Examples of the hydrolyzable group include an alkoxyl group such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group; a substituted alkoxyl group such as a 2-methoxyethoxy group and a 2-ethoxyethoxy group; an enoxy group such as an isopropenoxy group, Examples include a ketoximato group such as a methyl ethyl ketoxime group, an acetoxy group, and the like, which may be the same or different. An alkoxyl group or a ketoximato group is preferred because of its ease of synthesis, physical properties of the composition before curing, stability during storage, curability, economy, and use in a wide range of applications.

In the terminal group R ⁶ , the number r of hydroxyl groups (hydroxyl groups) or hydrolyzable groups X which are silicon functional groups is preferably 1 to 3. Such a silicon-functional polydiorganosiloxane is obtained by ring-opening polymerization or ring-opening copolymerization of a cyclic diorganosiloxane low monomer such as octamethylcyclosiloxane in the presence of water with an acidic catalyst or an alkaline catalyst, It can be obtained by introducing a hydroxyl group bonded to a silicon atom into the terminal of the obtained linear polydiorganosiloxane.

The silicon-functional polydiorganosiloxane in which X is a hydrolyzable group can be synthesized, for example, by condensing a silane having two or more arbitrary hydrolyzable groups to a polyorganosiloxane having a hydroxyl group at the terminal. it can. In this case, since one hydrolyzable group possessed by the silane is consumed by the condensation reaction, the number of X in the terminal group R ⁶ of the polyorganosilosan obtained by the reaction is the hydrolyzable group-containing silane used. One less than the number of hydrolyzable groups possessed by.

  Specific examples of the polyorganosiloxane as the component (A) include, for example, dimethylpolysiloxane, methylethylpolysiloxane, methyloctylpolysiloxane, methylvinylpolysiloxane, methylphenylpolysiloxane, methyl (3,3,3-tri Fluoropropyl) polysiloxane, a copolymer of dimethylsiloxane and methylphenylsiloxane, a copolymer of dimethylsiloxane and methyl (3,3,3-trifluoropropyl) siloxane, and the like. The molecular chain terminal of this polyorganosiloxane is blocked with a hydroxyl group or a hydrolyzable group (for example, alkoxyl group). The molecular chain terminal blocked with a hydroxyl group includes a dimethylhydroxysiloxy group, methylphenylhydroxysiloxy group. Examples of the molecular chain end blocked with an alkoxyl group include a vinyldimethoxysiloxy group, a methyldimethoxysiloxy group, a trimethoxysiloxy group, a methyldiethoxysiloxy group, and a triethoxysiloxy group.

  In an embodiment of the present invention, (B) the silicon compound having a ketoximato group that is an average of more than two hydrolyzable groups as silicon functional groups in the molecule is the silicon functional group in component (A). It reacts with a hydroxyl group (hydroxyl group) or a hydrolyzable group X to act as a crosslinking agent for curing the composition. Such a partial hydrolysis condensate of a silicon compound can also be used.

As the component (B) that is a crosslinking agent, for example, a general formula: R ⁸ _4-s SiY _s
(Wherein R ⁸ represents a substituted or unsubstituted monovalent hydrocarbon group which may be the same as or different from each other, Y represents a ketoximato group which is a hydrolyzable group, and s exceeds 2 on average. A silane represented by the following formula is used. Silane in which s is 2 is used in combination with silane in which s is 3 or 4.

Examples of R ⁸ include the same groups as the hydrocarbon group R ⁵ directly bonded to the silicon atom of the component (A), and the availability and the excellent crosslinking reaction rate are obtained. Group or vinyl group is preferred.

  Examples of the crosslinking agent as component (B) include methyltris (methylethylketoximato) silane, vinyltris (methylethylketoxymato) silane, phenyltris (methylethylketoxymato) silane, and the like, and these partial hydrolysates should also be used. Can do.

  (B) The compounding quantity of the silicon compound which has an average of more than two ketoximato groups in the molecule | numerator which is a component shall be 0.5-20 weight part with respect to 100 weight part of said (A) component. If the blending amount of component (B) is less than 0.5 parts by weight, sufficient crosslinking will not be achieved, and the strength of the cured product will not be insufficient. Sexuality gets worse. If the blending amount of component (B) exceeds 20 parts by weight, problems such as separation during storage and brittleness of the resulting cured product tend to occur, such being undesirable.

  In the embodiment of the present invention, the inorganic filler as the component (C) functions to impart consistency to the composition and mechanical strength to the cured product, and to impart flame retardancy. is there. A conventionally well-known thing can be used. Examples thereof include alkaline earth metal salts, inorganic oxides, metal hydroxides, and carbon black.

  Examples of alkaline earth metal salts include calcium, magnesium or barium carbonates, bicarbonates and sulfates. Examples of inorganic oxides include fumed silica, calcined silica, precipitated silica, quartz fine powder, metal oxides such as titanium oxide, iron oxide, and zinc oxide, diatomaceous earth, and alumina. Examples of the metal hydroxide include aluminum hydroxide. Moreover, you may use what surface-treated these with silanes, silazanes, siloxanes with low polymerization degree, or an organic compound. Furthermore, glass wool and fine powder mica can be used, and these fillers are added alone or as an arbitrary mixture.

  From the viewpoint of flame retardancy of cured products and storage stability of the composition, metal carbonates such as zinc carbonate and magnesium carbonate, quartz fine powder, metal oxides such as titanium oxide, zinc oxide and iron oxide, hydroxylation The use of hydroxides such as aluminum is preferred.

In particular, when zinc carbonate having the following physical properties is used, a composition having excellent flame retardancy and good adhesion can be obtained. That is, the weight reduction rate due to heating (for example, heating in thermogravimetry (TG)) is 33 to 36%, the weight reduction rate due to carbon dioxide generation during thermal decomposition is 30 to 35%, and the chemical formula: ZnCO ₃ It is preferable to use zinc carbonate having a high purity represented by: In TG, since zinc carbonate begins to decompose from a temperature of about 130 ° C., the temperature is gradually raised from room temperature (25 ° C.) and heated to 500 ° C., and the weight loss rate at this time is measured. The gas generated during pyrolysis is measured by a quantitative method using GC-MS and a weight method such as weighing the dissolved gas in an aqueous alkaline solution.

In general, zinc carbonate blended as a filler for silicone rubber is basic zinc carbonate (transparent zinc white) obtained by a wet process, and is represented by the chemical formula: 2ZnCO ₃ .3Zn (OH) ₂ .H ₂ O. The In such zinc carbonate (basic zinc carbonate), the weight reduction rate in TG is around 28%, and the weight reduction rate due to the generation of carbon dioxide during thermal decomposition is about 15 to 16%. On the other hand, the zinc carbonate preferably used in the embodiment of the present invention has a weight reduction rate of 33 to 36%, more preferably 34 to 36% in TG, and a weight reduction rate due to carbon dioxide generation during pyrolysis. Is 30 to 35%, and the amount of carbon dioxide generated per unit weight is large. Incidentally, the weight loss rate under heating conditions of 105 ° C. × 3 hours, which is a measure of the amount of water of crystallization and the amount of adsorbed water, is 0.1 to 0.2% by weight. In order to obtain a low modulus product, the average particle size of zinc carbonate is preferably in the range of 1.0 to 10 μm. Such zinc carbonate has an average particle size of 3.0 to 8.0 μm as measured by a laser method (for example, using LASER MICRON SIZER 7000S) and 1. 1 as measured by a Fischer method (for example, using FISHER SUB-SIEVE SIZER). The thing of 0-5.0 micrometers is preferable. In addition, use of such zinc carbonate having a larger particle diameter compared to general inorganic fillers such as quartz powder and titanium oxide also leads to improvement in workability.

  The amount of the inorganic filler as component (C) is 1 to 400 parts by weight per 100 parts by weight of component (A). (C) If the blending amount of the inorganic filler is less than 1 part by weight, the resulting cured product has extremely poor mechanical strength such as hardness and tensile strength. Conversely, if it exceeds 400 parts by weight, it has good rubber elasticity. Not only is it difficult to obtain a cured product, but the viscosity of the composition may increase and the operation may be difficult.

Alkoxysilane having an implementation is used in the form (D) an amino group-substituted alkyl group of the present invention have the general ^formula: represented by _{^{(R 1 O) 3-m}} R 2 m Si-R 3 ......... (1) The In formula (1), R ¹ represents the same or different alkyl groups. A methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group and the like are exemplified, and a methyl group is preferable. R ² also represents the same or different alkyl group. A methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group and the like are exemplified, and a methyl group is preferable. m shows the integer of 0-2.

R ³ represents a general formula: — (CH ₂ ) _p —CHR ⁴ — (CH ₂ ) _q —NH ₂ , or a general formula: — (CH ₂ ) _p —C (R ⁴ ) ₂ — (CH ₂ ) _q — An amino group-substituted alkyl group having a branch represented by NH ₂ is shown. Here, R ⁴ represents an alkyl group having 1 to ⁴ carbon atoms, preferably a methyl group or an ethyl group, and more preferably a methyl group. p and q each represent an integer of 1 to 8, and q is preferably 1. However, p + q is an integer of 9 or less.

Particularly preferred as such R ³ is a 4-amino-3,3-dimethylbutyl group represented by the formula: — (CH ₂ ) ₂ C (CH ₃ ) ₂ CH ₂ NH ₂ , or the formula: — ( CH ₂₎ a ₂ CH _(CH 3) 4- amino-3-methylbutyl group represented by _CH 2 NH _2.

  The amino group-containing alkoxysilane as the component (D) is blended in an amount of 0.05 to 15 parts by weight with respect to 100 parts by weight of the polyorganosiloxane as the component (A). (D) When the compounding amount of the amino group-containing alkoxysilane is less than 0.05 parts by weight, good initial adhesiveness cannot be obtained, and particularly, adhesion development at low temperatures is lowered and durability is insufficient. On the other hand, if the amount exceeds 15 parts by weight, liquid separation may occur in the container during storage, yellowing may occur, or water-resistant adhesiveness may deteriorate due to water immersion. (D) The more preferable range of the compounding quantity of the amino group containing alkoxysilane which is a component is 0.1-10 weight part with respect to 100 weight part of (A) polyorganosiloxane. Furthermore, in order to obtain sufficient workability in work conditions under high temperature and high humidity such as work outdoors in summer, the range of 0.1 to 5 parts by weight is more preferable.

  The curing catalyst which is the component (E) used in the embodiment of the present invention includes a hydroxyl group (hydroxyl group) and / or a hydrolyzable group of the component (A) and a hydrolyzable group (ketoximato group) of the component (B). And a catalyst that promotes the condensation reaction with the hydrolyzable group (alkoxyl group) of component (D). Specifically, metal organic acid salts such as iron octoate, iron naphthenate, cobalt octoate, cobalt naphthenate, tin octoate, tin naphthenate, lead octoate, lead naphthenate, dibutyltin diacetate, dibutyltin dilaurate, Alkyl tin ester compounds such as dibutyltin octoate, tin halide compounds, tin orthoester compounds, metal alcoholates such as tetrabutyl titanate and tetrabutyl zirconate, diisopropoxybis (acetylacetonato) titanium, diisopropoxybis ( Examples include titanium chelate compounds such as ethyl acetoacetate) and amines such as diethylhydroxylamine, dimethylhydroxylamine, and γ-tetramethylguanidylpropyltrimethoxysilane. These can be used alone or as a mixture of two or more.

  (E) The compounding quantity of the curing catalyst which is a component shall be 0.001-10 weight part with respect to 100 weight part of (A) component, More preferably, it shall be 0.02-2 weight part. When the component (E) is less than 0.001 part by weight, the curing rate is too slow to be suitable for practical use, and it takes a long time to form a tack-free film when the composition of the embodiment is exposed to the air. In addition, the developability of rubber strength may deteriorate. On the other hand, when the blending amount of the component (E) exceeds 10 parts by weight, the film formation time is extremely short as a few seconds, so that the workability is lowered and the heat resistance may be lowered.

  In the room temperature curable polyorganosiloxane composition of the embodiment, an alkoxysilane different from the component (D) can be added as a crosslinking agent in order to adjust curability and rubber strength after curing. Examples of such alkoxysilanes include tetrafunctional silanes such as tetramethoxysilane, tetraethoxysilane, methyl cellosolve orthosilicate, and n-propyl orthosilicate; methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, vinyl Examples include trifunctional alkoxysilanes such as trimethoxysilane, phenyltrimethoxysilane, and methyltrimethoxyethoxysilane, and partial hydrolysates thereof.

  In addition, the room temperature curable polyorganosiloxane composition of the embodiment may further contain an epoxy group-containing alkoxysilane in order to increase the adhesion reliability during water immersion. Examples of the epoxy group-containing alkoxysilane include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4- Epoxycyclohexyl) ethylmethyldimethoxysilane and the like are exemplified.

  Furthermore, a platinum-based compound or a complex compound thereof can be added to the composition of the embodiment in order to further improve the flame retardancy. Platinum compounds or their complex compounds include chloroplatinic acid and solutions in which it is dissolved in alcohol or other solvents, and platinum compounds such as chloroplatinic acid reacted with ethylene, cyclooctadiene or vinyl group-containing siloxanes. Examples thereof include those in which a ligand is coordinated to platinum such as a triphenylplatinum phosphite complex. The blending amount of such a platinum compound or its complex compound is preferably set to an amount of 1 to 2000 ppm as platinum atoms with respect to 100 parts by weight of component (A). Furthermore, organic solvents, diluents such as terminal trimethylsiloxylated dipolyorganosiloxane, plasticizers, thixotropic agents, colorants such as pigments and dyes, ordinary adhesion promoters, fungicides, etc. are required It can be added depending on.

  The room temperature curable polyorganosiloxane composition of the present invention is a one-component room temperature curing by uniformly mixing the components (A) to (E) and the other components described above in a dry atmosphere. Obtained as a composition. When this composition is exposed to air, it causes a crosslinking reaction due to moisture and cures to a rubber elastic body. In addition, it contains a main ingredient containing the components (A) and (C), the components (B) and the components (D) to (E), and further contains the component (F) and other components as necessary. It can also be prepared as a two-component room temperature curable composition with a curing agent. In the two-pack type composition, the main agent and the curing agent are mixed in the air to be cured in the same manner as the one-pack type room temperature curable composition.

Furthermore, the composition of the embodiment of the present invention includes a heat resistance improver such as Bengala and cerium oxide, a cold resistance improver, a dehydrating agent, a rust preventive, a reticulated polysiloxane composed of a triorganosiloxane unit and a SiO ₂ unit. A predetermined amount of the liquid reinforcing agent can be added as necessary.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited to a following example. In the examples, “parts” means “parts by weight”, and the viscosity is a value measured at 23 ° C.

Example 1
80 parts of α, ω-dihydroxydimethylpolysiloxane (viscosity 80,000 mPa · s) blocked at both ends of the molecular chain with hydroxyl groups, 1.5 parts of vinyltris (methylethylketoxymato) silane and methyltris (methylethylketoxymato) silane 2 .5 parts were blended and mixed uniformly. Next, 100 parts of quartz fine powder (trade name: Crystallite VX-S: manufactured by Tatsumori Co., Ltd.) having an average particle diameter (hereinafter simply referred to as an average particle diameter) measured by the Fischer method of 4.0 μm and carbon After 10 parts of black were blended and mixed uniformly, 20 parts of α, ω-dihydroxydimethylpolysiloxane (viscosity 80,000 mPa · s) was further added and mixed uniformly.

  Next, after adding 0.08 part of dibutyltin dilaurate as a curing catalyst and 1 part of triphenyl phosphite complex solution (0.18 part of triphenyl phosphite, chloroplatinic acid propanol solution) to the mixture, By adding 1 part of methyl ketoxime, 3.3 parts of methyltris (methylethylketoximato) silane, and 1.2 parts of 4-amino-3,3-dimethylbutylmethyldimethoxysilane, and mixing them uniformly, polyorgano A siloxane composition was obtained.

Comparative Examples 1 and 2
In place of 1.2 parts of 4-amino-3,3-dimethylbutylmethyldimethoxysilane which is a constituent of Example 1, γ-aminopropylmethyldimethoxysilane (trade name Silquest A-2100: Momentive Performance Material 1.2 parts (comparative example 1) and N- (β-aminoethyl) -aminopropylmethyldimethoxysilane (trade name Silquest A-2120: made by Momentive Performance Material Japan LLC) 1 .2 parts (comparative example 2) were used respectively. Other than that was carried out similarly to Example 1, and obtained the polyorganosiloxane composition.

Example 2
To 80 parts of α, ω-dihydroxydimethylpolysiloxane (viscosity 80,000 mPa · s) blocked at both ends of the molecular chain with a hydroxyl group, 5.0 parts of phenyltris (methylethylketoximato) silane was blended and mixed uniformly. . Next, 100 parts of quartz fine powder (trade name: Crystallite VX-S) having an average particle size of 4.0 μm and 10 parts of carbon black were blended and mixed uniformly, and then α, ω-dihydroxydimethylpolysiloxane. (Viscosity 80,000 mPa · s) 20 parts were added and mixed uniformly.

  Next, after adding 0.08 part of dibutyltin dilaurate as a curing catalyst and 1 part of triphenyl phosphite complex solution (0.18 part of triphenyl phosphite, chloroplatinic acid propanol solution) to the mixture, Add 3.5 parts of phenyltris (methylethylketoximato) silane, 1 part of n-octyltriethoxysilane, and 1.2 parts of 4-amino-3,3-dimethylbutylmethyldimethoxysilane, and mix uniformly. Thus, a polyorganosiloxane composition was obtained.

Comparative Examples 3 and 4
Instead of 1.2 parts of 4-amino-3,3-dimethylbutylmethyldimethoxysilane which is a constituent of Example 2, 1.2 parts of γ-aminopropylmethyldimethoxysilane (trade name Silquest A-2100) (comparison) Example 3) and 1.2 parts of N- (β-aminoethyl) -aminopropylmethyldimethoxysilane (trade name Silquest A-2120) (Comparative Example 4) were used. Other than that was carried out similarly to Example 2, and obtained the polyorganosiloxane composition.

Example 3
To 80 parts of α, ω-dihydroxydimethylpolysiloxane (viscosity 80,000 mPa · s) blocked at both ends of the molecular chain with a hydroxyl group, 5.0 parts of phenyltris (methylethylketoximato) silane was blended and mixed uniformly. . Next, 80 parts of quartz fine powder (trade name: Crystallite VX-S) having an average particle diameter of 4.0 μm and zinc carbonate having an average particle diameter of 1.91 μm (the weight loss rate upon heating at 105 ° C. × 3 hours is 0) 0.07% and the weight loss rate by TG is 34.7% .The weight loss rate due to the generation of carbon dioxide gas is 34%.) 20 parts and 10 parts of carbon black were mixed and mixed uniformly. 20 parts of ω-dihydroxydimethylpolysiloxane (viscosity 80,000 mPa · s) was added and mixed uniformly.

  Next, after adding 0.08 part of dibutyltin dilaurate as a curing catalyst and 1 part of triphenyl phosphite complex solution (0.18 part of triphenyl phosphite, chloroplatinic acid propanol solution) to the mixture, Add 3.5 parts of phenyltris (methylethylketoximato) silane, 1 part of n-octyltriethoxysilane, and 1.2 parts of 4-amino-3,3-dimethylbutylmethyldimethoxysilane, and mix uniformly. Thus, a polyorganosiloxane composition was obtained.

Reference example 4
50 parts of α, ω-dihydroxydimethylpolysiloxane (viscosity 20,000 mPa · s) blocked at both ends of the molecular chain with a hydroxyl group, and α- (trimethylsilyloxy) -ω- (hydroxy) blocked at one end with a hydroxyl group A mixture of 50 parts of dimethylsilyloxy-dimethylpolysiloxane (viscosity 10,000 mPa · s), 80 parts of quartz fine powder (trade name: Crystallite VX-S) having an average particle diameter of 4.0 μm, and an average particle diameter 1.19 μm zinc carbonate (weight loss rate when heated at 105 ° C. for 3 hours is 0.07%, weight loss rate at TG is 34.7%, weight loss rate due to generation of carbon dioxide gas is 34%) 20 parts Were mixed and uniformly mixed, and this was used as the main agent.

  In addition, 4.475 parts of α, ω-vinyldimethylsilyldimethylpolysiloxane (viscosity: 3,000 mPa · s) blocked at both ends with vinyldimethylsilyl groups, 2.5 parts of carbon black, phenyltris (methylethylketoximato ) 2.0 parts of silane, 0.5 parts of 4-amino-3,3-dimethylbutylmethyldimethoxysilane, 1.0 part of γ-glycidoxypropylmethyldimethoxysilane and 0.025 part of dibutyltin oxide were added respectively. And mixed to obtain a curing agent. And the main ingredient and the hardening | curing agent were mixed by the weight ratio of 10: 1, and the polyorganosiloxane composition was obtained.

Next, with respect to the polyorganosiloxane compositions obtained in Examples 1 to 3, Reference Example 4 and Comparative Examples 1 to 4, the touch drying time, physical properties, flame retardancy and adhesiveness are as shown below. Was measured and evaluated.

  (A) Drying time of finger touch: After extruding the composition in an atmosphere of 23 ° C. and 50% RH, the time to contact the surface with a finger and confirm that it was in a dry state was measured.

  (B) Physical properties: A sheet obtained by extruding the composition into a sheet having a thickness of 2 mm was allowed to stand at 23 ° C. and 50% RH for 168 hours, and cured by moisture in the air. And the physical characteristic of hardened | cured material was measured based on JISK6301.

  (C) Flame retardancy: A flame retardancy test was performed by a method based on UL94, and the burning time was measured.

  (D) Adhesiveness: The composition was applied on each adherend shown in Table 1, and allowed to stand at 23 ° C. and 50% RH for 168 hours to be cured by moisture in the air, and then the cured product and the adherend. Were pulled and peeled in the direction of 180 °, and the cohesive failure rate was measured. In addition, as a polybutylene terephthalate resin which is an adherend, Duranex 2012 (manufactured by Wintech Polymer Co., Ltd.) was used. Moreover, TSE2183U (made by Momentive Performance Material Japan GK) was used as the flame retardant silicone rubber.

  These results are shown in Table 1. In the abbreviations in the table, Tmax represents maximum tensile stress, and Emax represents elongation at maximum load.

As can be seen from Table 1, the curable polyorganosiloxane compositions obtained in Examples 1 to 3 are excellent in curability and adhesiveness. In addition, the cured product has high extensibility and excellent flame retardancy.

  The room temperature curable polyorganosiloxane composition of the present invention has excellent adhesion to the adherend, and the cured product is highly extensible and excellent in flame retardancy. Useful.

Claims (4)

(A) 100 parts by weight of a polyorganosiloxane having a molecular chain terminal blocked with a hydroxyl group or a hydrolyzable group and having a viscosity at 23 ° C. of 20 to 1,000,000 mPa · s;
(B) 0.5 to 20 parts by weight of a silane having a ketoximato group having an average number of more than 2 as a silicon functional group in the molecule or a partial hydrolyzate thereof ,
(C) 1 to 400 parts by weight of an inorganic filler,
(D) the general ^{_{formula: (R 1 O) 3-}} m R 2 m Si-R 3 ......... (1)
(In the formula, R ¹ and R ² represent the same or different alkyl groups. M is an integer of 0 to 2. Also, R ³ represents a general formula: — (CH ₂ ) _p —CHR ⁴ — (CH _{2) q} -NH ₂ or the formula ^{_{:-( CH 2) p -C (R}} 4) 2 - (CH 2) q -NH 2
The amino group substituted alkyl group which has the branch represented by these is shown. Here, R ⁴ represents an alkyl group having 1 to ⁴ carbon atoms, and p and q are each an integer of 1 to 8. However, p + q is an integer of 9 or less. 0.05 to 15 parts by weight of an alkoxysilane having an amino group-substituted alkyl group represented by :
(E) curing catalyst 0.001 to 10 parts by weight , and
A room temperature curable polyorganosiloxane composition comprising (F) a platinum compound or a complex compound thereof as a flame retardant additive .   The room temperature-curable polyorganosiloxane composition according to claim 1, wherein the (E) curing catalyst is a tin-based curing catalyst. The room temperature-curable polyorganosiloxane composition according to claim 1 or 2, wherein the platinum compound or a complex compound thereof is a triphenylplatinum phosphite complex .   The room temperature-curable polyorganosiloxane composition according to any one of claims 1 to 3, further comprising an alkoxysilane different from the component (D) or a partial hydrolyzate thereof as a crosslinking agent.