JP5547037B2 - Room temperature curable polyorganosiloxane composition - Google Patents

Description

  The present invention relates to a room temperature curable polyorganosiloxane composition. More specifically, the present invention is stable under a sealed condition in the absence of moisture, and cures at room temperature by contact with moisture in the air to form a rubber-like elastic body. The present invention relates to a polyorganosiloxane composition which is useful as an elastic adhesive or a sealing material.

  Conventionally, as a silicone composition having good adhesion, a reaction product or a mixture of a polyorganosiloxane having a hydroxyl group at the molecular chain end, an alkoxysilane having an aminoalkyl group and an alkoxysilane having an epoxyalkyl group, and a curing catalyst There is known a polyorganosiloxane composition having an adhesiveness to various substrates that are in contact with each other during curing (see, for example, Patent Document 1). However, the silicone rubber obtained by curing this composition has a low water-resistant adhesive property, and has a drawback that the adhesive property is deteriorated particularly in a harsh environment such as hot water immersion in float glass.

  Moreover, in order to improve water-resistant adhesiveness, it is proposed to mix | blend a disila alkane compound and a long chain alkyl group containing silane (for example, refer patent document 2, 3). However, these proposed compositions have a problem that not only the effect of blending is not sufficient, but also the preparation takes time. Furthermore, a composition comprising a silane compound containing a long-chain alkyl group and a reaction mixture of an aminoalkylalkoxysilane and an epoxyalkylalkoxysilane has also been proposed. Further, there is a problem that the extensibility of the cured product is remarkably lowered by the blending of the epoxyalkylalkoxysilane.

Japanese Patent Publication No. 63-23226 JP-A 64-60656 JP 2003-221506 A

  The present invention has been made to solve these problems, and is a room temperature curable polyorgano that provides an adhesive rubber-like cured product having excellent curability, high strength, moisture resistance and warm water resistance. An object is to provide a siloxane composition.

  As a result of intensive studies to achieve the above-described object, the present inventors can obtain a room temperature-curable organopolysiloxane composition having excellent characteristics by blending an epoxy compound containing a branched alkyl group. The present invention has been completed.

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) 0.1 to 20 parts by weight of an epoxy compound having a branched alkyl group, (C) 1 to 400 parts by weight of a filler, and (D) 0.001 to 10 parts by weight of a curing catalyst. (B) The epoxy compound having a branched alkyl group is an oxirane compound in which two alkyl groups are branched from one carbon atom constituting the epoxy ring, or an epoxy in a molecular chain having a branched alkyl group. It is a compound containing a ring .

  According to the room temperature curable polyorganosiloxane composition of the present invention, by adding an epoxy compound having a branched alkyl chain to a polyorganosiloxane whose molecular chain end is blocked with a hydroxyl group or a hydrolyzable group, A composition excellent in moisture resistance can be obtained without causing a decrease. Further, this composition has good curability, shows good adhesion to various substrates, has good mechanical strength, and is excellent in hot water resistance.

  Embodiments of the present invention will be described below. The room temperature curable polyorganosiloxane composition of the embodiment includes (A) a polyorganosiloxane having a molecular chain terminal blocked with a hydroxyl group or a hydrolyzable group, and a viscosity at 23 ° C. of 20 to 1,000,000 mPa · s. , (B) an epoxy compound having a branched alkyl group, (C) a filler, and (D) a curing catalyst. Hereinafter, each component of the room temperature curable polyorganosiloxane composition of the embodiment will be described.

  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 base component of the room temperature curable composition of the present invention. If the viscosity of the component (A) is too low, the rubber elasticity after curing becomes poor, and if it is too high, the workability decreases, so the viscosity at 23 ° C. is preferably in the range of 20 to 1,000,000 mPa · s. A range of 100 to 100,000 mPa · s is preferable.

The molecular structure of the polyorganosiloxane is preferably a straight chain represented by the following general formula (1), but may have a partially branched structure.

In formula (1), R ¹ represents a substituted or unsubstituted monovalent hydrocarbon group which may be the same or different from each other, and R ² is _a monovalent organic group represented by —ZSiR ³ _3-a Xa. Represents a group. Here, Z represents oxygen (oxo group) or a divalent hydrocarbon group, and R ³ 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 a is an integer of 1 to 3. Moreover, n is a number which makes the viscosity at 23 degreeC of the said (A) component the range of 20-1,000,000 mPa * s.

R ¹ 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; and aralkyl groups such as 2-phenylethyl group and 2-phenylpropyl group. In addition, hydrogen atoms of these hydrocarbon groups are substituted with other atoms or groups, that is, halogens such as chloromethyl group, 3-chloropropyl group, 3,3,3-trifluoropropyl group A substituted hydrocarbon group such as a cyanoalkyl group such as a 3-cyanopropyl group. 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 ¹ is a methyl group, and more preferably substantially all R ¹ is a methyl group.

In particular, when imparting heat resistance, radiation resistance, cold resistance or transparency to the composition, a necessary amount of phenyl groups as part of R ¹ , 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 ¹ or a surface having paintability is provided, a long chain alkyl group or an aralkyl group is provided as a part of R ^1. Can be arbitrarily selected depending on the purpose, for example, in combination with a methyl group.

The terminal group R ^{2 of the} component (A) is represented by the formula: —ZSiR ³ _3-a X _a and is a silicon functional siloxy having at least one hydroxyl group (hydroxyl group) or hydrolyzable group X which is a silicon functional group. Unit. 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 ² , R ³ 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 examples thereof are the same as those described above for R ¹ . It may be the same as or different from R ¹ . A methyl group or a vinyl group is preferred 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. Examples of the divalent hydrocarbon group include an alkylene group such as a methylene group, an ethylene group and a trimethylene group; a phenylene group and the like. Is done. 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 hydrolyzable group which is a silicon functional group present in at least one R ² which is a terminal group. Examples of the hydrolyzable group include an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group; a substituted alkoxy group such as a 2-methoxyethoxy group and a 2-ethoxyethoxy group; an enoxy group such as an isopropenoxy group, Examples thereof include a ketoximato group such as a methyl ethyl ketoxime group and an acetoxy group. The plurality of hydroxyl groups or hydrolyzable groups may be the same or different. An alkoxy group or a ketoximato group is preferred because it is easily synthesized, has physical properties before being cured, is stable during storage, is curable, is economical, and is used in a wide range of applications.

In the end groups R ^2, number a hydroxyl or hydrolyzable group X is a silicon functional group is preferably 1-3. A silicon-functional polydiorganosiloxane in which X is a hydroxyl group is a ring-opening polymerization or ring-opening copolymerization of a cyclic diorganosiloxane low monomer such as octamethylcyclosiloxane in the presence of water using an acidic catalyst or an alkaline catalyst. And by introducing a hydroxyl group bonded to a silicon atom into the terminal of the 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 ² 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 component (A) include dimethylpolysiloxane, methylethylpolysiloxane, methyloctylpolysiloxane, methylvinylpolysiloxane, methyl group whose molecular chain ends are blocked with a hydroxyl group or a hydrolyzable group (for example, alkoxyl group). Phenylpolysiloxane, methyl (3,3,3-trifluoropropyl) polysiloxane, copolymer of dimethylsiloxane and methylphenylsiloxane, copolymer of dimethylsiloxane and methyl (3,3,3-trifluoropropyl) siloxane Etc.

  Examples of molecular chain ends blocked with a hydroxyl group include dimethylhydroxysiloxy group and methylphenylhydroxysiloxy group. Examples of molecular chain ends blocked with an alkoxy group include vinyldimethoxysiloxy group, methyldimethoxysiloxy group, trimethoxy group. Examples include a siloxy group, a methyldiethoxysiloxy group, and a triethoxysiloxy group. Furthermore, examples of the molecular chain end blocked with a ketoximato group include a methyl ethyl ketoximato group, a dimethyl ketoximato group, a diethyl ketoximato group, a methylbutyl ketoximato group, a methylhexyl ketoximato group, and an ethylpentyl ketoximato group. The

  In the embodiment of the present invention, the epoxy compound containing the branched alkyl group as the component (B) is effective for imparting adhesion to the substrate and improving the durability of the adhesive under severe conditions such as immersion in hot water. Have.

で表される[２，２，３，３，４，４，５，５，６，６，７，７，８，８，９，９，１０，１１，１１，１１−エイコサフルオロ−１０−（トリフルオロメチル）−ウンデシル]オキシランのようなオキシランの誘導体、グリシジルイソプロピルエーテル、２−エチルヘキシルグリシジルエーテル（CAS番号：2461-15-6）、tert-ブチルグリシジルエーテル（CAS番号：7665-72-7）のような分岐アルキル基を含有するグリシジルエーテルが挙げられる。 Examples of the branched alkyl group-containing epoxy compound as component (B) include 2-propyl-2-hexyloxirane, 2-methyl-2- (2-methylpropyl) oxirane (CAS number: 53897-31-7), 2-methyl-2-propyloxirane (CAS number: 3657-41-8), 2,2-di (tert-pentyl) oxirane (CAS number: 64046-71-5), (3,3-dimethylbutyl) oxirane (CAS number: 53907-77-0), 2-ethyl-3-propyloxirane (CAS number: 53897-32-8), 2,3-dipropyloxirane (CAS number: 27415-21-0), 2, 3-dihexyloxirane (CAS number: 85721-27-3), 2,3-dibutyloxirane (CAS number: 53248-86-5), the following formula (2)

[2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,11,11,11-eicosafluoro-10 Derivatives of oxiranes such as-(trifluoromethyl) -undecyl] oxirane, glycidyl isopropyl ether, 2-ethylhexyl glycidyl ether (CAS number: 2461-15-6), tert-butyl glycidyl ether (CAS number: 7665-72- Examples thereof include glycidyl ethers containing a branched alkyl group as in 7).

で表されるシス−７，８−エポキシ−２−メチルオクタデカンや、Ｎ−プロピル−Ｎ−（２，３−エポキシプロピル）ペルフルオロ−ｎ−オクチルスルホンアミド（CAS番号：77620-64-5）などが例示される。 Moreover, as (B) branched alkyl group containing epoxy compound, following formula (3)

Cis-7,8-epoxy-2-methyloctadecane represented by the formula, N-propyl-N- (2,3-epoxypropyl) perfluoro-n-octylsulfonamide (CAS number: 77620-64-5), etc. Is exemplified.

  The epoxy compound containing a branched alkyl group as described above can be obtained by forming a compound branched from one carbon atom of the epoxy ring by the reaction of a carbonyl compound (aldehyde or ketone) and sulfur ylide. Yes (Journal of the American Chemical Society 87: 6 March 20,1965 p1353-1364).

  2-butanone to 2-methyl-2-ethyloxirane, 3-pentanone to 2,2-diethyloxirane, diisopropylketone to 2,2-diisopropyloxirane, diisobutylketone to 2,2-diisobutyloxirane, 2- Heptanone to 2-methyl-2-pentyloxirane, 3-heptanone to 2-ethyl-2-butyloxirane, 3-hexanone to 2-ethyl-2-propyloxirane, 3-octanone to 2-ethyl-2- Pentyloxirane is dibutyl ketone to 2,2-di-n-butyloxirane, 2-nonanone to 2-methyl-2-heptyloxirane, 3-nonanone to 2-ethyl-2-hexyloxirane, 5-nonanone From 2,2-di-n-butyloxirane, respectively. . Also, 2-decanone to 2-methyl-2-octyloxirane, 3-decanone to 2-ethyl-2-heptyloxirane, 4-decanone to 2-propyl-2-hexyloxirane, and 2-undecanone to 2- Methyl-2-nonyloxirane, 6-undecanone to 2-di-n-heptyloxirane, 2-hexadecanone to 2-methyl-2-tetradecyloxirane, 4-heptanone to 2-di-n-propyloxirane 2-methyl-2-isobutyloxirane from methyl isobutyl ketone, 2-methyl-2-isopropyloxirane from methyl isopropyl ketone, and (2,6-dimethyl) -2-butyl from 2,6-dimethyl-4-heptanone The oxirane is converted from 3-methyl-2-butanone to 2-methyl-2-isopro Ruokishiran is obtained, respectively.

  Similarly, it is also possible to convert olefins into epoxides (double bond epoxidation reaction) using m-chloroperbenzoic acid or dimethyldioxirane as a catalyst (Chemical Reviews, 1993, Vol. 93, No.4 p1307-1370)). And if the double bond in a molecule | numerator is converted, the compound which has an epoxy ring in molecular chains like the above-mentioned cis-7,8-epoxy-2-methyloctadecane will be obtained, and a double bond will be added to a side chain. If the compound which has it is converted, the compound branched from one carbon atom of the epoxy ring like 2-propyl-2-hexyloxirane can be obtained. These reactions may be carried out industrially by oxidation with hydroperoxide.

  In the embodiment of the present invention, (B) the epoxy compound having a branched alkyl group is preferably one having a long branched alkyl group in terms of the effect of improving the epoxy ring reactivity and adhesion durability. In particular, an oxirane compound having an alkyl group branched from one carbon atom constituting an epoxy ring, such as 2-propyl-2-hexyloxirane, or a cis-7 containing an epoxy ring in a molecular chain having a branched alkyl group , 8-epoxy-2-methyloctadecane is preferred.

  (B) The compounding quantity of a branched alkyl group containing epoxy compound shall be 0.1-20 weight part with respect to 100 weight part of polyorganosiloxane which is (A) component, Preferably it is 0.5-10 weight part.

  In embodiment, it is preferable to mix | blend (E) aminoalkyl alkoxysilane with such (B) branched alkyl group containing epoxy compound. (E) As aminoalkylalkoxysilane, aminomethyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldimethoxysilane, N- (2-ethyl) aminopropyltri Methoxysilane, N- (2-aminoethyl) aminomethyltributoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane , 3-anilinopropyltriethoxysilane and the like.

  The blending amount of (E) aminoalkylalkoxysilane is such that the blending ratio (molar ratio) of (B) branched alkyl group-containing epoxy compound and (E) aminoalkylalkoxysilane is 1: 9 to 9: 1, preferably 5: The range is 5 to 8: 2. When (E) aminoalkylalkoxysilane is used in combination at this blending ratio (molar ratio), the amino group of (E) aminoalkylalkoxysilane reacts with the epoxy group of (B) the branched alkyl group-containing epoxy compound. A synergistic effect can be obtained. That is, a synergistic effect of adhesion of aminosilane and improvement of water resistance of epoxysilane is obtained, and the durability of adhesion under immersion in warm water is greatly improved as compared with the case where (E) aminoalkylalkoxysilane is not used in combination. Moreover, the onset of adhesiveness is fast, and good adhesiveness is exhibited with respect to more adherends.

  In addition, when the aminoalkylalkoxysilane as the component (E) is blended, it is preliminarily mixed with the (B) branched alkyl group-containing epoxy compound and left at room temperature or heat-treated as necessary. Reaction mixtures can be formulated. The heat treatment temperature is from room temperature to 120 ° C, preferably 50 to 100 ° C. When the reaction mixture obtained in this way is blended, the effect is quickly manifested compared to the case where the two components are simply blended without mixing, and there is an advantage that the effect of improving water resistance can be obtained immediately after blending. . Moreover, there is no possibility of deterioration due to immersion in warm water due to residual amino groups.

  In the embodiment, the filler as the component (C) functions to impart consistency to the composition and to impart mechanical strength to the cured product. A 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, titanium oxide, iron oxide, zinc oxide, diatomaceous earth, and alumina. Examples of the metal hydroxide include aluminum hydroxide. In addition, a surface treatment of these alkaline earth metal salts, inorganic oxides, and metal hydroxides with silanes, silazanes, low-polymerization siloxanes, or organic compounds may be used.

  In particular, the use of calcium carbonate is preferred. (C) When calcium carbonate is used as a filler, high fluidity can be imparted to the composition before curing, and high mechanical strength can be imparted to the cured product. The particle size (average particle size) of calcium carbonate 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. On the other hand, when the average particle size is less than 0.005 μm, the viscosity of the composition before curing is increased and the fluidity is lowered. In addition to the untreated calcium carbonate surface, those whose surface is treated with a fatty acid, a resin (rosin) acid, an ester compound, a silicic acid compound, or the like can also be used.

  The amount of the filler as component (C) is 1 to 400 parts by weight per 100 parts by weight of component (A). (B) When the addition amount of the filler is less than 1 part by weight, the mechanical strength such as hardness and tensile strength of the cured product obtained from the composition is remarkably inferior, and when 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.

  The curing catalyst that is the component (D) of the embodiment is a catalyst that promotes the condensation reaction of the hydroxyl group (hydroxyl group) and / or the hydrolyzable group of the component (A) and promotes the curing of the composition. 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, Alkyltin ester compounds such as dibutyltin octoate; diketonate metal salts such as dibutyltin bis (acetyl acetate), dibutyltin bis (ethylacetylacetate), dibutyltin bis (butylacetylacetate), dibutyltin bis (2-ethylhexylacetylacetate); Metal alcoholates such as tin halide compounds, tin ortho ester compounds, tetrabutyl titanate, tetrabutyl zirconate; diisopropoxybis (acetylacetonate) titanium, diisopropo Shibisu titanium chelate compounds such as (ethyl acetoacetate) titanium; diethylhydroxylamine, dimethylhydroxylamine, amines such as γ- tetramethylguanidylpropyltrimethoxysilane trimethoxysilane can be exemplified. These can be used alone or as a mixture of two or more.

  (D) 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, you may be 0.01-5 weight part. When the component (D) 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 is exposed to the air. The expression of rubber strength, which is one of the objects of the invention, may be deteriorated. On the other hand, when the blending amount of the component (D) exceeds 10 parts by weight, the film formation time is extremely short as a few seconds, so that workability is lowered and heat resistance may be lowered.

  In the room temperature curable polyorganosiloxane composition of the embodiment, an alkoxysilane containing an epoxy group can be further blended in order to further improve the adhesion reliability during water immersion. Examples of the epoxy group-containing alkoxysilane include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4- Epoxycyclohexyl) ethylmethyldimethoxysilane and the like are exemplified. In a composition containing carbon black described later, black fading can be reduced by adding an epoxy group-containing alkoxysilane.

  The compounding amount of such an epoxy group-containing alkoxysilane is 0.05 to 10 parts by weight, more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the component (A). If the compounding amount of the epoxy group-containing alkoxysilane is less than 0.05 parts by weight, sufficient adhesion reliability and rubber strength at the time of water immersion cannot be obtained, while if it exceeds 10 parts by weight, curing and adhesion are exhibited. Become slow. Further, the viscosity of the composition is increased, workability such as ejection properties is lowered, and the cured rubber may become too hard.

  Furthermore, an isocyanurate compound such as 1,3,5-tris [3- (trimethoxysilyl) propyl] cyclotriisocyanurate is added to improve adhesion to various substrates when the composition is cured. can do. Since such an isocyanurate compound and the epoxy group-containing alkoxysilane have little influence on the curing catalyst, the curability is hardly lowered.

  Furthermore, the composition of the embodiment includes an alkoxysilane different from the epoxy group-containing alkoxysilane and the aminoalkylalkoxysilane as the component (E) as a crosslinking agent in order to adjust curability and rubber strength after curing. Can be added. Examples of such alkoxysilanes include tetrafunctional silanes such as tetramethoxysilane, tetraethoxysilane, methyl cellosolve orthosilicate, and n-propyl orthosilicate; methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, vinyl Trifunctional alkoxysilanes such as trimethoxysilane, phenyltrimethoxysilane, methyltrimethoxyethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, dodecyltrimethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, dodecyltriethoxysilane Class: methyltris (methylethylketoximato) silane, methyltris (methylethylketoxymato) silane, vinyltris (methylethylketoximato) ) Silane, phenyltris (methylethylketoximato) silane, methyltris (methylbutylketoxymato) silane, vinyltris (methylbutylketoxymato) silane, phenyltris (methylbutylketoxymato) silane, tetrakis (methylethylketoxymato) silane, tetrakis ( And ketoximatosilanes such as methylbutylketoxymato) silane. The compounding amount of these alkoxysilanes is preferably 0.1 to 20 parts by weight with respect to 100 parts by weight of the component (A).

  Furthermore, an organic solvent and a diluent (plasticizer) can be mix | blended with the polyorganosiloxane composition of embodiment as needed. As the diluent, polydimethylsiloxane having both ends trimethylsiloxylated, polydimethylsiloxane having both ends dimethylvinylsiloxylated, or the like can be used. In addition, a colorant such as carbon black, a flame retardant, a thixotropic agent, an adhesion improver (adhesion promoter), an antifungal agent, and the like may be added as long as the object of the present invention is not impaired.

  The room temperature curable polyorganosiloxane composition of the present invention is a one-part room temperature curable by uniformly mixing each component of (A) to (D) and the other components described above in a dry atmosphere. Obtained as a composition. When this composition is exposed to air, the crosslinking reaction proceeds due to moisture, and the composition is cured into a rubber elastic body. Moreover, the hardening which contains (A) and (C) component, the (B) component and (D) component, and also mix | blends (E) component and other components as needed. It can also be prepared as a two-component room temperature curable composition with an 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.

  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 “%” means “% by weight”. Moreover, all physical properties such as viscosity are measured values at 23 ° C. and relative humidity (RH) 50%.

Example 1
Calfine 200MH, which is calcium carbonate (synthetic calcium carbonate) surface-treated with stearic acid on 50 parts of α, ω-dihydroxypolydimethylsiloxane (viscosity 10,000 mPa · s) blocked at both ends of the molecular chain with hydroxyl groups Trade name: manufactured by Maruo Calcium Co., Ltd.) (average particle size 0.05 μm, BET specific surface area 17 m ² / g) was added and mixed, and this was used as the main agent.

  Further, 55.6 parts of α, ω-divinylpolydimethylsiloxane having a vinyldimethylsilyl group at both ends (viscosity 1,000 mPa · s), 7.9 parts of 7,8-epoxy-2-methyloctadecane and 3- A reaction mixture obtained by mixing 5 parts of aminopropyltrimethoxysilane and heating at 70 ° C. for 12 hours, 15 parts of carbon black VULCAN XC72 (trade name; average particle size 30 nm; manufactured by CABOT), n-propyl orthosilicate 15 parts and 1.5 parts of dioctyltin dilaurate were added and mixed to make a curing agent.

  The main agent and the curing agent thus obtained were mixed at a weight ratio of 100: 10 to obtain a polyorganosiloxane composition.

Examples 2-16
Main agents and curing agents were prepared in the same manner as in Example 1 except that the types and amounts of the components to be blended were changed as shown in Tables 1 and 2. And the main ingredient and the hardening | curing agent were mixed by the weight ratio of 100: 10, and the polyorganosiloxane composition was obtained.

  In Example 2, Example 13 and Example 15, a reaction mixture obtained by heat treatment of 7,8-epoxy-2-methyloctadecane and 3-aminopropyltrimethoxysilane was not blended. The ingredients were blended separately. In Example 3, Example 5, Examples 7-9, Examples 11-12, Example 14 and Example 16, component (B) 7,8-epoxy-2-methyloctadecane, 2-propyl A reaction mixture of 2-hexyloxirane or 2-ethylhexyl glycidyl ether and (E) component 3-aminopropyltrimethoxysilane or N- (2-ethyl) aminopropyltrimethoxysilane was blended. In Example 4, 2-propyl-2-hexyloxirane and 3-aminopropyltrimethoxysilane were blended separately without being heated and reacted in advance. In Example 6, 2-ethylhexylglycidyl was blended. Ether and 3-aminopropyltrimethoxysilane were blended separately. Further, in Example 10, 7,8-epoxy-2-methyloctadecane and N- (2-ethyl) aminopropyltrimethoxysilane were blended separately without being heated and reacted in advance.

Comparative Examples 1-18
The components shown in Table 3 and Table 4 were blended in the compositions shown in the same table, and the base agent and the curing agent were prepared in the same manner as in Example 1. And the main ingredient and the hardening | curing agent were mixed by the weight ratio of 100: 10, and the polyorganosiloxane composition was obtained.

  In Comparative Example 1, Comparative Examples 5 to 7, and Comparative Examples 12 to 18, a reaction mixture in which 3-aminopropyltrimethoxysilane and 3-glycidoxypropyltrimethoxysilane were heated and reacted was blended. . In Comparative Example 2, these components were blended separately rather than blending a reaction mixture of 3-aminopropyltrimethoxysilane and 3-glycidoxypropyltrimethoxysilane. Furthermore, in Comparative Example 8 and Comparative Example 11, a reaction mixture obtained by heating N- (2-ethyl) aminopropyltrimethoxysilane and 3-glycidoxypropyltrimethoxysilane was blended, and Comparative Example In No. 9, these components were blended separately as they were without being heated and reacted.

  Next, the appearance (blackness) of the polyorganosiloxane compositions obtained in Examples 1 to 16 and Comparative Examples 1 to 18 after the initial stage and after heat-promoted deterioration (left at 70 ° C. for 5 days) was examined. Also, the adhesion durability was measured and evaluated. Furthermore, in order to investigate the influence of the blending of the branched alkyl group-containing epoxy compound and aminoalkylalkoxysilane on the discharge performance, the discharge amount of the curing agent used in Examples 1 to 16 and Comparative Examples 1 to 18 It was measured after heat-induced degradation (left at 70 ° C. for 5 days). The measurement results are shown in Tables 5-8.

  In addition, the external appearance (blackness) observed the difference in the color of the composition obtained by mixing a main ingredient and a hardening | curing agent with the naked eye. The viscosity was measured using a rotational viscometer DIGITAL VISMETRON VDH type (manufactured by Shibaura System Co., Ltd.) in an atmosphere of 23 ° C. and 50% RH. The discharge amount and adhesion durability were measured by the following methods.

<Measurement of discharge amount>
A curing agent (composition) was filled into a 6 oz (about 177 ml) SEMCO cartridge, and 5 kg of curing agent was applied at 3 kg / cm ² pressure from a dedicated nozzle (3 mm inner diameter at the tip) attached to the tip of the cartridge. Extruding for a second, the weight (g) of the extruded curing agent was measured.

<Measurement and evaluation of adhesion durability>
In accordance with the method prescribed in JIS K5758 architectural sealant, an adhesion durability test specimen was prepared. That is, after filling the polyorganosiloxane composition obtained by mixing the main agent and the curing agent between two float glass plates (float plate glass defined in JIS R3202), the temperature is 23 ° C. and the humidity is 50%. The composition was allowed to stand for 7 days under the conditions described above to cure. A tensile test was performed on the specimen (H-type specimen) thus obtained, and 50% modulus (M50), maximum tensile stress (Tmax), and elongation at maximum load (Emax) were examined. In addition, the ruptured state of the silicone rubber was observed to examine the adhesion. Further, a tensile test was performed on the same specimens immersed in warm water of 80 ° C. for 30 days and 60 days, respectively, and 50% modulus (M50), maximum tensile stress (Tmax), and elongation at maximum load. (Emax) and adhesion were measured respectively. In the fractured state, CF is a cohesive failure (destruction at the silicone rubber layer), TCF is a thin layer failure (destruction leaving a thin layer of silicone rubber at the interface with the glass plate), and AF is an adhesive failure (with glass plate). (Removal at the silicone rubber interface).

  As can be seen from Tables 5 to 8, the room temperature curable polyorganosiloxane compositions obtained in Examples 1 to 16 have better curability than the compositions obtained in Comparative Examples 1 to 18. The cured product has good mechanical strength, excellent extensibility and adhesion, and particularly excellent adhesion durability.

Example 17
Hakujyuka TDD, which is calcium carbonate treated with rosin acid on 100 parts of α, ω-bis (trimethoxysiloxy) polydimethylsiloxane (viscosity 21,000 mPa · s) blocked at both ends by methoxy groups Name: Shiraishi Kogyo Co., Ltd.) (average particle size 0.14 μm, BET specific surface area 16.0 m ² / g) 75 parts and super calcium carbonate 2000 (trade name; Maruo Calcium Co., Ltd.) ) (Average particle size 1.1 μm, BET specific surface area 2.0 m ² / g) 75 parts are added and mixed, and α, ω-bis (trimethylsiloxy) polydimethylsiloxane having both ends blocked with trimethylsilyl groups ( 30 parts of viscosity (100 mPa · s) was added and mixed uniformly.

  Subsequently, 0.7 parts of 7,8-epoxy-2-methyloctadecane and 0.4 parts of 3-aminopropyltrimethoxysilane were mixed and heated at 70 ° C. for 12 hours, 2 parts of methoxysilane and 3 parts of diisopropoxybis (ethylacetylacetate) titanium were added and mixed to obtain a polyorganosiloxane composition.

Examples 18-26
A polyorganosiloxane composition was obtained in the same manner as in Example 17 except that the type and amount of each component to be blended were changed as shown in Table 9. In Example 18, Example 20, Example 24, and Example 26, instead of blending a heated reaction product of 7,8-epoxy-2-methyloctadecane and 3-aminopropyltrimethoxysilane, These ingredients were blended separately. In Example 21, a reaction mixture obtained by heating 2-propyl-2-hexyloxirane and 3-aminopropyltrimethoxysilane was blended. In Example 22, 2-propyl-2-hexyloxirane was blended. Hexyloxirane and 3-aminopropyltrimethoxysilane were blended separately without heating reaction.

Comparative Examples 19-27
Each component shown in Table 10 was blended in the composition shown in the same table and mixed in the same procedure as in Example 1 to obtain a polyorganosiloxane composition.

  Next, with respect to the polyorganosiloxane compositions obtained in Examples 17 to 26 and Comparative Examples 19 to 27, respectively, the extrusion force (discharge force) and the tax free after the initial stage and after heat-promoted deterioration (left at 70 ° C. for 5 days) Time and hardness were measured by the following methods. In addition, a tensile test was performed on the H-shaped specimen in the same manner as described above, and 50% modulus (M50) after initial and hot water immersion, maximum tensile stress (Tmax), elongation at maximum load (Emax), silicone rubber The fracture state was examined. The measurement results are shown in Table 11 and Table 12.

<Extruding force>
Using an autograph manufactured by Shimadzu Corporation, the force at the time of discharging from a nozzle whose tip diameter was adjusted to 6.2 mm was measured.

<Tack-free time>
After extruding the composition in an atmosphere of 23 ° C. and 50% RH, the surface was contacted with a finger, and the time taken to confirm that it was in a dry state was measured.

<Hardness>
The composition was extruded into a sheet having a thickness of 2 mm, and the obtained sheet was left to stand at 23 ° C. and 50% RH for 7 days to be cured by moisture in the air. And the hardness of hardened | cured material was measured based on JISK6301.

  As can be seen from Tables 11 to 12, the room temperature curable polyorganosiloxane compositions obtained in Examples 17 to 26 have better curability than the compositions obtained in Comparative Examples 19 to 27. The cured product has good mechanical strength, excellent extensibility and adhesion, and particularly excellent adhesion durability.

Claims (5)

(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) 0.1-20 parts by weight of an epoxy compound having a branched alkyl group;
(C) 1 to 400 parts by weight of a filler, and (D) 0.001 to 10 parts by weight of a curing catalyst ,
(B) The epoxy compound having a branched alkyl group is an oxirane compound in which two alkyl groups are branched and bonded from one carbon atom constituting the epoxy ring, or an epoxy ring in a molecular chain having a branched alkyl group A room temperature-curable polyorganosiloxane composition characterized by comprising:   The room temperature-curable polyorganosiloxane composition according to claim 1, further comprising (E) 0.05 to 10 parts by weight of aminoalkylalkoxysilane.   The compounding ratio (molar ratio) of the epoxy compound containing the (B) branched alkyl group and the (E) aminoalkylalkoxysilane is 1: 9 to 9: 1. A room temperature curable polyorganosiloxane composition.   The room temperature-curable polyorganosiloxane composition according to claim 2 or 3, comprising a reaction mixture of the epoxy compound (B) having a branched alkyl group and the (E) aminoalkylalkoxysilane.   The room temperature-curable polyorganosiloxane composition according to any one of claims 1 to 4, wherein the filler (C) is a surface-treated calcium carbonate.