JPS5938989B2 - Room temperature moisture curable organopolysiloxane composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a one-pack room temperature moisture curable organopolysiloxane composition.

Various types of one-pack type organopolysiloxane compositions that cure at room temperature and humidity are known, but types that cure while releasing alcohol are particularly effective because they do not emit unpleasant odors and do not corrode metals. Because of this characteristic, it is preferably used for sealing, adhesion, and coating of electrical and electronic equipment. As a representative example of this type, Japanese Patent Publication No. 39-27643 discloses a composition comprising a hydroxyl end-blocked organopolysiloxane, an alkoxysilane, and an organic titanium compound;
No. 28 discloses a composition comprising at least two alkoxy end-capped organopolysiloxanes and an organic acid metal salt, an organic titanium compound or amines. However, the composition disclosed in Japanese Patent Publication No. 39-27643 has the drawback that the viscosity increases rapidly immediately after mixing the three components, and the viscosity does not decrease unless it is left for a while, making it extremely difficult to manufacture.

Furthermore, among the compositions disclosed in Japanese Patent Publication No. 47-3028, a one-pack type organopolysiloxane composition that can be cured at room temperature and humidity and withstands long-term storage uses an organic titanium compound as a curing catalyst. However, it has drawbacks such as slow internal curing when exposed to moisture during use and insufficient adhesion to metals, plastics, etc. The present invention provides an improved one-pack type organopolysiloxane composition that cures with moisture at room temperature while releasing alcohol and is an improved one-pack type organopolysiloxane composition that cures while releasing alcohol with moisture at room temperature. An object of the present invention is to provide an organopolysiloxane composition that cures while releasing . In other words, it can be stored for a long time without viscosity increasing immediately after mixing the ingredients, hardens not only on the surface but also inside when exposed to moisture, and adheres well to adherends at room temperature. The present invention provides an organopolysiloxane composition that cures while releasing alcohol due to moisture.

The present invention provides (a) a viscosity at 25°C of at least 3
Organopolysiloxane which is 0CS and has at least two silicon atoms bonded with alkoxy groups in one molecule
100 parts by weight (b) 95 to 5% by weight of a tin salt of carboxylic acid and an alkyl silicate or a partial hydrolyzate thereof represented by the average composition formula (1) (here, Bi is a monovalent hydrocarbon group, and R″5 is a carbon A heat-treated product of a mixture consisting of 5 to 95% by weight of a monovalent hydrocarbon group of number 6 or less, where c is O to 1, d is 1 to 4, but c+d is 4 or less.0.
05 to 5 parts by weight (c) Aminoalkylalkoxysilane or parts thereof can be present and can be packaged in one package.

In other words, it can be stored for a long time in a cartridge or tube.
When pressed out of the cartridge or tube during use, it immediately begins to harden due to the moisture in the air, hardening not only on the surface but also on the inside in a short time, and also adheres well to metals, plastics, etc. It has Organopolysiloxane containing silanol groups (
It is disclosed in JP-A No. 50-15744 that a heat-treated mixture of a tin salt of a carboxylic acid and an alkyl silicate or a partially hydrolyzed product thereof is cured at room temperature.
No. 7 and U.S. Pat. No. 3,186,963, both of which provide a type of room-temperature-curable organopolysiloxane composition that cures even in the absence of moisture, that is, a two-pack type room-temperature-curable organopolysiloxane composition. The present invention is distinct in that it provides a room temperature curable organopolysiloxane composition that does not adhere or has poor adhesion to bodies.

Next, each component will be explained in detail.

(a) The component has a viscosity of at least 30C at 25°C.
S, which is an organopolysiloxane having at least two silicon atoms bonded to alkoxy groups in one molecule.

The molecular structure may be linear, branched, network, or three-dimensional. It may be either liquid or solid at room temperature, but is preferably liquid,
It is preferable to use a solid substance by dissolving it in an organic medium. The lower limit of the degree of polymerization is 30CS at 25°C.
The degree of polymerization is such that it exhibits the above, and the upper limit is not particularly limited, but is preferably tens of thousands CS or less. There must be two or more silicon atoms bonded to an alkoxy group;
It is preferable that the two be present at positions as far apart as possible in the molecule. The units constituting this organopolysiloxane are (R'0)3S1005 units, (R/O)2RS
i00.5 units, (R'0) approximately SlOO. 5 units, (R
O) 2RSiCH2C1-12Si (ρ..5 units,
R(R'O)SIO unit, R2SiO unit, (Y(0)
SiOl. 5 units, RSiOl. , units and other siloxane units and SiO4 units are exemplified. Here, R is a substituted or unsubstituted monovalent hydrocarbon group, such as an alkyl group such as a methyl group, an ethyl group, or a propyl group, a vinyl group,
Alkenyl groups such as allyl group and hexenyl group, cycloalkyl groups such as cyclohexyl group and cycloheptyl group,
Aryl groups such as phenyl group, tolyl group, xylyl group,
Aralkyl groups such as benzyl group and phenylethyl group, halogen-substituted monovalent hydrocarbon groups such as chlorophenyl group, tetrachlorophenyl group, chloroethyl group, pentafluoropropyl group, and trifluoropropyl group, etc.
b) 50 moles of ingredients as a whole? It is preferable that the above group is a methyl group.

R' is a monovalent hydrocarbon group having 6 or less carbon atoms, such as methyl group, ethyl group, propyl group, butyl group, vinyl group, cyclohexyl group, methoxyethyl group, chloroethyl group, phenyl group, etc. Preferred are methyl group, ethyl group, and propyl group. (b) Ingredients are 95 to 5% by weight of a tin salt of carboxylic acid and 5 to 9% of an alkyl silicate or a partial hydrolyzate thereof represented by the average composition formula (1).
It is obtained by heat treating a mixture consisting of 5% by weight. Examples of tin salts of carboxylic acids include dibutyltin dilaurate, dibutyltin dioctoate, dibutyltin diacetate, tributyltin monolaurate, monobutyltin trilaurate, tin naphthenate, tin oleate, and tin octoate. Regarding the alkyl silicate or its partial hydrolyzate represented by the average compositional formula (1), Bi in the formula is a monovalent hydrocarbon group, and the same ones as R mentioned above are exemplified.

Further, R1'7 is a monovalent hydrocarbon group having 6 or less carbon atoms, and among those exemplified as R' above, an alkyl group is exemplified. Those that are liquid at room temperature are preferred, such as methyltriethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, vinyltrimethoxysilane, phenyltrimethoxysilane, methyltri(methoxyethoxy)silane, dimethyltetraethoxydisiloxane, methyl There are orthosilicate, ethyl orthosilicate, propyl orthosilicate, hexyl orthosilicate, methyl polysilicate, propyl polysilicate, and butyl polysilicate. The heat treatment of the above mixture is preferably carried out by heating and stirring the mixture at a temperature of 80 to 200° C. for about 10 minutes or more.

At this time, it is desirable to remove generated esters and the like from the system. The amount of component (b) used is 0.05 to 5 parts by weight per 100 parts by weight of component (a). This is 0.0
If the amount is less than 5 parts by weight, the curing reaction of the organopolysiloxane composition will not proceed sufficiently, while if it is more than 5 parts by weight, the curing reaction will proceed too much and it will not be possible to obtain a product that can withstand practical use. (c) component is an aminoalkylalkoxysilane or a partially hydrolyzed condensate thereof,
For example, γ-aminopropyltrimethoxysilane, γ-
Examples include aminopropyltriethoxysilane, N-(trimethoxysilylpropyl)ethylenediamine, δ-aminobutyl(methyl)diethoxysilane, NN'-bis(trimethoxysilylpropyl)ethylenediamine, and partial hydrolysates thereof.

The amount of component (c) used is 0 per 100 parts by weight of component (b).
．． The amount is 1 to 10 parts by weight. If the amount is less than 0.1 part by weight, the composition will not cure sufficiently when exposed to moisture, and if it exceeds 10 parts by weight, it will be susceptible to discoloration and its heat resistance will be reduced. Each of the above three components is not limited to one type, but may be used in the form of a mixture of two or more types. The organopolysiloxane composition of the present invention can be obtained by mixing the above-mentioned components, but there are no other points to keep in mind other than mixing while being careful not to raise the temperature and mixing under moisture exclusion.

In addition to the above three essential components, when component (a) has a high viscosity or a thickening filler is added, the average composition formula ( The alkyl silicate represented by 1) or its partial hydrolyzate is added as necessary. Also, fumed silica, precipitated silica, fused silica, fine quartz powder, diatomaceous earth,
Glass fibers, glass balloons, aluminum silicate, calcium silicate, calcium carbonate, talc, mica, carbon black, alumina, titania, zirconia, zinc oxide, iron oxide, magnesium oxide, fillers such as asbestos, platinum compounds and manganese carbonate. Add various additives as necessary, such as flame retardants such as carbonate and zinc carbonate, and heat resistants such as cerium hydroxide and iron naphthenate. It may also be used after being dissolved in an organic solvent such as toluene or xylene. The composition of the present invention can be applied to metals, plastics, rubber, glass, ceramics, ceramics, stone, wood, painted surfaces, textile products,
It is extremely useful as an adhesive, sealant, or coating agent for various materials such as paper.

Next, reference examples and examples of the present invention will be listed, and in each example, all parts are by weight.

Reference Example A catalyst component was produced by mixing and heating a silicate and a tin salt of carboxylic acid under the conditions shown in Table 1, and removing by-product ester from the system.

Example 1 A linear dimethylpolysiloxane 100f with a viscosity of 2000CS at 25°C and both ends blocked with methyldimethoxysiloxy groups! V:) 3. Add 0.5 parts of the heated mixture of methyltrimethoxysilane and dibutyltin diacetate and 3 parts of γ-aminopropyltrimethoxysilane under the protection of moisture and mix until homogeneous. did.

This mixture can be stored for at least two months under moisture protection, and when poured onto a pure aluminum slab indoors, the air-contact surface becomes non-stick in about 20 minutes and has a thickness of about 1 m.
W! In this case, it completely cured in about 1 day, took on a rubber-like appearance, and adhered well to the pure aluminum plate. As a comparative example, a mixture was prepared in which only γ-aminopropyltrimethoxysilane was not added, and this mixture cured in two days even under moisture-blocking conditions. Also, it did not adhere firmly to the pure aluminum plate. Example 2 Instead of the mixed heat-treated product of Table 1 in Example 1, . When a similar mixture was prepared using a heated mixture of /F6cn-propyl orthosilicate and dibutyltin dioctoate, the same results as in Example 1 were obtained.

Example 3 To 100 parts of a linear dimethylpolysiloxane having a viscosity of 12,000 CS at 25°C and having both terminals blocked with methyldimethoxysiloxy groups, 14 parts of fumed silica having a surface area of 200 m2/9 which had been cured with hexamethyldisilazane and treated with water was added, The mixture was thoroughly mixed until homogeneous and degassed.

To this, 0.35 parts of the heat-treated mixed mixture of ethyl orthosilicate and dibutyltin diacetate shown in Table 1, 1.5 parts of N-(trimethoxysilylpropyl)ethylenediamine, and 6 parts of methyltrimethoxysilane were added to prevent moisture. The mixture was stirred and mixed until homogeneous, then filled into an aluminum tube and sealed tightly. When the contents were extruded from the aluminum tube and poured into an aluminum mold coated with a mold release agent to a depth of 3 m and 71 L and left in an atmosphere of 25°C and 60% RH, the surface became no longer sticky in about 15 minutes. After a few days, the inside was completely cured. About this rubber sheet JI
The hardness and strength and elongation were measured according to SK63Ol, and the hardness was 26, tensile strength was 25 kg/d, and elongation was 300? It was hot.
In addition, in accordance with JISA5755, glass plates and acrylic resin-coated aluminum plates are used as adherends.
When adhesive test pieces of the mold were made and the initial tensile adhesive strength was measured, the glass plate was 4.8k9/d and the aluminum plate was 4.3kg/CTil, both of which are so-called cohesive failures in which the rubber itself breaks. It was hot.

Furthermore, although the aluminum tube was left at room temperature for 3 months, no appreciable change was observed in the viscosity of the contents, curing speed, physical properties of the rubber after curing, and adhesiveness compared to immediately after manufacture. Example 4 In a glass container with a seal, 41 mol% of methylsiloxane units and 29 mol% of phenylsiloxane units were contained. , 30 moles of dimethylsiloxane units? 100 parts of a solid polymethylphenylsiloxane resin containing 2.8% by weight of silicon-supplied ethoxy groups and 100 parts of xylene were added and shaken well to dissolve the resin.

To this was added 1.0 part of a heated mixed mixture of ethyl polysilicate and dibutyltin dilaurate shown in Table 1 and 2.2 parts of γ-aminopropyltriethoxysilane, and the mixture was mixed and sealed. This mixture did not change in viscosity even after being left at room temperature for 3 months. When poured from a glass container onto a glass plate and a mild steel plate placed in a room, the approximately 0.5 mm thick portion was completely cured in about one day, indicating good adhesion to the glass plate and mild steel plate. was extremely good.

Claims (1)

[Scope of Claims] 1 (a) 100 parts by weight of an organopolysiloxane having a viscosity at 25° C. of at least 30 CS and having at least two alkoxy group-bonded silicon atoms in one molecule (b) Tin salt of carboxylic acid 95 ~5% by weight and average composition formula (
1) Alkyl silicate or its partial hydrolyzate R″cSi(OR″′)d[O4-cd]/2
(1) (where R″ is a monovalent hydrocarbon group, R″′ is a monovalent hydrocarbon group with 6 or less carbon atoms, c is 0 to 1, d is 1 to 4, but c+d is 4 or less) 5 to 0.05 to 5 parts by weight of a heat-treated mixture consisting of 95% by weight (c) 0.1 to 10 parts by weight of aminoalkylalkoxysilane or its partial hydrolyzate
A room temperature moisture curable organopolysiloxane composition comprising parts by weight. 2. The organopolysiloxane having at least two alkoxy group-bonded silicon atoms in one molecule of component (a) is characterized in that it is a linear diorganopolysiloxane in which alkoxy groups are bonded to silicon atoms at both ends. A room temperature moisture curable organopolysiloxane composition according to claim 1. 3. The room temperature moisture-curable organopolysiloxane composition according to claim 1, wherein the silicon-bonded alkoxy group of component (a) is a methoxy group or an ethoxy group. 4. The room temperature moisture-curable organopolysiloxane composition according to claim 1, wherein the tin salt of carboxylic acid used in component (b) is a diorganotin salt of an aliphatic carboxylic acid. 5. The room temperature wet curable organopolysiloxane composition according to claim 4, wherein the diorganotin salt of an aliphatic carboxylic acid is a dibutyltin salt of an aliphatic carboxylic acid. 6. The room temperature moisture-curable organopolysiloxane composition according to claim 1, wherein the aminoalkylalkoxysilane of component (c) is an aminoalkyltrialkoxysilane. 7. Room temperature humidity according to claim 6, wherein the aminoalkyltrialkoxysilane is γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, or N-(trimethoxysilylpropyl)ethylenediamine. Curable organopolysiloxane composition.