KR100787372B1 - Liquid silicone rubber coating composition - Google Patents

Abstract

The present invention relates to diorganopolysiloxanes having a viscosity at 25 ° C. of 100 to 100,000 mPa · s and containing at least two alkenyl groups per molecule, organopolysiloxane resins containing at least two silicon-bonded hydrogen atoms per molecule, inorganic A liquid silicone rubber coating composition comprising a filler, a platinum group catalyst, an organotitanium compound and one or more alkyl silicates and / or alkyl polysilicates. The composition provides a liquid silicone rubber coating composition for forming a thin film on a substrate, such as a synthetic fiber fabric or a glass fiber fabric, which exhibits strong adhesion at low temperatures and can form a film that is not tacky after curing. The silicone rubber coated fabrics thus obtained are useful as electrical insulation, diaphragms, seals, tent cloths, automotive airbags, conduit lakes, medical devices and apparel materials.

Liquid Silicone Rubber Coating Composition, Diorganopolysiloxane, Organopolysiloxane Resin, Inorganic Filler, Platinum Group Catalyst, Alkyl Silicate, Alkyl Polysilicate, Silicon Bonded Hydrogen Atom, Adhesive, Adhesion, Alkenyl Group

Description

Liquid silicone rubber coating composition

FIELD OF THE INVENTION The present invention relates to liquid silicone rubber compositions which are cured by hydrosilylation reactions, and more particularly suitable for use as thin films on substrates, which are cured upon heating for a short time, so that the resulting cured coatings It relates to a liquid silicone rubber composition of the above-described form exhibiting excellent adhesion.

For example, base fabrics, including synthetic fiber woven fabrics such as nylon 66, inorganic fibers such as glass fibers, and the like, when coated with a silicone rubber composition, have many advantages including good thermal properties, flammability, and good storage stability. To provide. Thus, substrate fabrics of this kind have been used in various articles including airbags, in particular automotive airbags. Additional advantages provided by coating a material made of glass fiber woven fabric with a silicone rubber composition include improved wear resistance, flexibility, and shape retention.

When organic solvents, such as toluene or xylene, generally cover a base fabric made from synthetic or glass fibers, the silicone rubber composition is diluted to obtain a thin, uniform coating on the base fabric and a strong bond between the coating and the base fabric. Used to achieve this. Due to efforts to meet industrial conditions for solvent-free compositions due to environmental concerns, liquid silicone rubber compositions have recently been proposed that can be applied without the use of organic solvents. One of these proposed liquid silicone rubber coating compositions is a Japanese patent which describes a composition having better adhesion to the base fabric as compared to the prior art and a reduced level of tack of the coating applied on the substrate film surface after heating and curing. Publication No. Hei 9-87585 (US Pat. No. 5789084).

However, by reducing the thickness of the film on recently coated fabrics to reduce weight, the heat resistance is reduced, and the industry seeks to shorten the time required to heat and cure the coating composition to reduce energy usage. . Therefore, it is necessary to provide good adhesion between the liquid silicone rubber and the base fabric at shorter temperatures at lower temperatures. Typically, the textile industry, and in particular the airbag industry, seeks short oven residence times at temperatures of 150-180 ° C. Preferably, the oven residence time is less than 1 minute, during which time a sufficiently strong adhesion should be formed between the liquid silicone rubber and the textile fibers. These conditions are based on the normal production level of the coated material and the thermal stability of the fabric substrate. However, in the case of the compositions described in Japanese Patent Application Laid-Open No. 9-87585, the inventors have found that the composition is excellent by heating and curing in a short time such as 1 minute unless the composition has a sufficiently good affinity with the substrate material to which it is usually bonded. It was found that adhesion could not be obtained.

The present inventors have conducted research for the purpose of solving the above problems, and as a result, when the alkyl silicate or alkyl polysilicate is added to a liquid silicone rubber coating composition containing an organopolysiloxane resin and an organotitanium compound, the product has a very short heating and The present invention has been found to exhibit good adhesion to substrates such as synthetic fiber fabrics or glass fiber fabrics even after curing time.

The present invention seeks to provide a liquid silicone rubber coating composition suitable for application as a thin film on a substrate, such as a synthetic or glass fiber fabric, wherein the resulting cured coating is cured at lower temperatures in less time than coatings of the prior art. Strong adhesion to the substrate is shown and no tack after curing.

The present invention

(A) diorganopolysiloxanes having a viscosity at 25 ° C. of 100 to 100,000 mPa · s and containing at least two alkenyl groups per molecule,

(B) organopolysiloxane resin,

(C) inorganic fillers,                     

(D) at least two silicon-bonded hydrogens per molecule in an amount such that the ratio of the number of mols of silicon-bonded hydrogen atoms in the component to the number of mols of alkenyl groups contained in the total composition is from 0.6: 1 to 20: 1. Organopolysiloxanes containing atoms,

(E) platinum group catalysts and

(F) contains an organotitanium compound,

(G) A liquid silicone rubber coating composition further comprising at least one alkyl silicate and / or alkyl polysilicate.

Preferably, the composition

(A) 100 parts by weight of diorganopolysiloxane having a viscosity at 25 ° C. of 100 to 100,000 mPa · s and containing at least two alkenyl groups per molecule,

(B) 5 to 100 parts by weight of the organopolysiloxane resin,

(C) 5 to 100 parts by weight of the inorganic filler,

(D) at least two silicon-bonded hydrogens per molecule in an amount such that the ratio of the number of mols of silicon-bonded hydrogen atoms in the component to the number of mols of alkenyl groups contained in the total composition is from 0.6: 1 to 20: 1. Organopolysiloxanes containing atoms,

(E) platinum group catalyst in an amount corresponding to 0.1 to 500 parts by weight per 1,000,000 parts by weight of component (A),

(F) 0.1 to 5 parts by weight of the organotitanium compound and

(G) 0.1 to 20 parts by weight of alkyl silicate or alkyl polysilicate.                     

Component (A), which is a diorganopolysiloxane having a viscosity at 25 ° C. of 100 to 100,000 mPa · s and containing two or more alkenyl groups per molecule, is a main component of the composition of the present invention, and the composition of the present invention is cured silicone rubber It must contain at least two alkenyl groups per molecule to be a coating.

Such diorganopolysiloxanes have substantially average units of the formula R _n SiO _{(4-n) / 2} where R is a substituted or unsubstituted monovalent hydrocarbon group, examples of which include methyl, ethyl, propyl or isopropyl Alkyl groups; alkenyl groups such as vinyl groups, allyl groups, or hexenyl groups; aryl groups such as phenyl groups; and halogenated alkyl groups such as 3,3,3-trifluoropropyl groups; n is from 1.9 to Is a linear organopolysiloxane. The viscosity of this diorganopolysiloxane should be within the range of 100 to 100,000 mPa · s, preferably 1000 to 50,000 mPa · s at 25 ° C., taking into account the strength of the resulting silicone rubber film. Specific examples of this component include dimethylvinylsiloxy endblocked dimethylpolysiloxanes, dimethylvinylsiloxy endblocked dimethylsiloxane-methylvinylsiloxane copolymers, dimethylvinylsiloxy endblocked dimethylsiloxane-methylphenylsiloxane copolymers and dimethylvinylsiloxane End-blocked methyl (3,3,3-trifluoropropyl) siloxane-methylvinylsiloxane copolymers are included.

Component (B), which is an organopolysiloxane resin, is an essential ingredient that increases the mechanical strength of the silicone rubber coating and, in particular, enhances the penetration of the silicone rubber into synthetic and glass fiber fabrics and improves adhesion to the substrate. Examples of siloxane units constituting such organopolysiloxane resins include R ^a ₃ SiO _{1 /} as terminal groups together with a blend of R ^a SiO _3/2 units and / or SiO _4/2 and optionally R ^a ₂ SiO _2/2 units. ₂ units are included. R ^a groups in the formula may each be the same or different, and are substituted or unsubstituted monovalent hydrocarbon groups, examples of which include alkyl groups such as methyl groups, ethyl groups, and propyl groups; Aryl groups such as phenyl groups; And alkenyl groups such as vinyl groups, allyl groups or hexenyl groups. In view of ease of synthesis and the possibility of preparing the necessary raw materials, preferred R ^a groups are methyl, ethyl and / or phenyl groups, which increase the strength of the silicone rubber film from which the above-mentioned resin is produced, and thus further contain alkenyl groups Resin is more preferable. Such organopolysiloxane resins may contain from 1 to 10% by weight of silanol groups that can be silylated by treatment with hexamethyldisilazane or organochlorosilane.

Component (B) is preferably a liquid at room temperature or a solid miscible with component (A). In connection with improving the penetration of the synthetic and / or glass fiber fabrics while at the same time improving the formation of the thin film, component (B) is preferably added in an amount of from 5 to 80 parts by weight, more preferably from 10 to 80 parts by weight. .

Component (C), which is an inorganic filler, may be a filler commonly used to reinforce silicone rubber, control viscosity, improve heat resistance or improve flammability. Examples of such inorganic fillers include fused silica, precipitated silica, calcined silica and other reinforcing silicas described above, and include organosilicones such as organochlorosilanes, organoalkoxysilanes, hexaorganodisilazane and diorganocyclopolysiloxanes. Can be treated with a compound. Other reinforcing fillers may include colloidal calcium carbonate, carbon black, molten titanium oxide. Non-reinforcing fillers that may be used may include crushed quartz, diatomaceous earth, iron oxide, aluminum oxide, calcium bicarbonate and magnesium carbonate. These inorganic fillers can be used alone or in combination. Among these, reinforced silica having a specific surface area of 50 m ² / g or more is preferable. Particularly advantageous fillers are surface treated ultrafine silica powders such as ultrafine reinforced silica which are pretreated with organochlorosilanes, organoalkoxysilanes, hexaorganodisilazane, diorganocyclopolysiloxanes and the like. Alternatively, the treatment agent may be mixed in the composition. Although content of this component changes with kinds of inorganic filler, it is generally 1-100 weight part per 100 weight part of component (A). If ultrafine silica is used, it is preferably present in an amount of 1 to 30 parts by weight per 100 parts by weight of component (A). This is because, when the amount of silica exceeds this range, the viscosity of the composition of the present invention is so great that the coating operation becomes difficult, and the mechanical strength of the silicone rubber film becomes within this range.

Component (D) is an organopolysiloxane which acts as a crosslinking agent and contains at least two silicon-bonded hydrogen atoms per molecule. Examples thereof include trimethylsiloxy endblocked methylhydrogenpolysiloxane, trimethylsiloxy endblocked dimethylsiloxane-methylhydrogensiloxane copolymer, dimethylphenylsiloxy endblocked methylphenylsiloxane-methylhydrogensiloxane copolymer, cyclic methyl _{Hydrogenpolysiloxanes} and copolymers consisting of dimethylhydrogensiloxy units and SiO _4/2 units. The viscosity of component (D) is generally 1-1000 mPa * s. This component has a ratio of mol number of silicon-bonded hydrogen atoms in the component to mol number of alkenyl groups contained in the whole composition of the present invention is 0.6: 1 to 20: 1, preferably 1: 1 to 10: 1. It is contained in such an amount as possible.

Component (E) is a platinum group catalyst used to cure the composition of the present invention. Examples thereof include platinum fine powder, platinum black, chloroplatinic acid, platinum tetrachloride, olefin complexes of chloroplatinic acid, alcohol solutions of chloroplatinic acid, complexes of chloroplatinic acid with alkenylsiloxane, rhodium compounds and palladium compounds. This platinum group catalyst is generally used in an amount of 0.1 to 500 parts by weight, preferably 1 to 50 parts by weight, per 1,000,000 parts by weight of component (A). If it is less than a lower limit, the said composition will not harden | cure at a suitable speed, and if it exceeds an upper limit, it is unpreferable in terms of cost.

Component (F), which is an organotitanium compound, is an adhesion promoter that enhances the adhesion of the resulting coating to substrates such as synthetic and / or glass fiber fabrics and also reduces the adhesion of the cured coating surface. Examples of such organotitanium compounds include organotitanate esters such as tetraisopropyl titanate, tetrabutyl titanate and tetraoctyl titanate and diisopropoxybis (acetylacetonate) titanium and diisopropoxybis (ethyl aceto Titanium chelate compounds such as acetate) titanium. Such component (F) is present in the composition in an amount of 0.1 to 5 parts by weight per 100 parts by weight of component (A). When component (F) is added in an amount exceeding 5 parts by weight, the storage stability of the composition of the present invention is adversely affected, and below 0.1 part by weight, the effect of deterioration of the adhesion of the film surface after curing does not appear.

Component (G), which is an alkyl silicate or alkyl polysilicate, is an essential ingredient for achieving adhesion to substrates such as synthetic and glass fiber fabrics when the composition of the present invention is heated for a short time. The average chemical formula of such alkyl silicate or alkyl polysilicate is shown in the following formula (1).

Si _p O _(p-1) (OR ^b ) _{(2p + 2)}

In Chemical Formula 1,

R ^b is an alkyl group such as methyl, ethyl or propyl group,

p is an integer from 1 to 20.

In addition to the linear structure as the main component, cyclic, side chain or network structures may also be contained, which may be homopolymers or copolymers. Its viscosity is generally 0.1 to 100 mPa · s at 25 ° C. This component is preferably added in an amount of 0.01 to 20 parts by weight, more preferably 0.1 to 20 parts by weight, most preferably 0.1 to 10 parts by weight per 100 parts by weight of component (A). If it is less than 0.1 part by weight, there is a tendency to generate insufficient adhesive force by heating for a short time such as 1 minute, and if the above range is exceeded, the storage stability of the composition of the present invention may be disadvantageous.                     

It is preferable that the liquid silicone rubber coating composition of this invention contains an epoxy group containing organosilicon compound (component (H)). Component (H) further enhances the adhesion of the compositions according to the invention to substrates such as synthetic fiber fabrics and glass fiber fabrics. Examples of such organosilicon compounds include epoxy group-containing organoalkoxysilanes such as γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, silicon-bonded vinyl Epoxy group-containing organopolysiloxanes containing groups and alkoxy groups, Epoxy group-containing organopolysiloxanes containing silicon-bonded hydrogen atoms, Epoxy group-containing organopolysiloxanes containing silicon-bonded hydrogen atoms and alkoxy groups and other epoxy groups Contains organopolysiloxanes are included. Examples thereof include compounds having the following average structural formula.

In the above formula,

Me is a methyl group,

Vi is a vinyl group.

In addition to these components, it is advantageous to add curing retarders or inhibitors (component (J)). Examples of component (J) include alkyne alcohols such as 3-methyl-1-butyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol and phenylbutinol; Ene-yne compounds such as 3-methyl-3-penten-1-yne and 3,5-dimethyl-3-hexene-1-yne; Tetramethyltetrahexenylcyclotetra-siloxane; And benzotriazoles. Component (J) is generally added in an amount of 0.01 to 10 parts by weight per 100 parts by weight of component (A). Various additives such as pigments, heat stabilizers and the like can also be used to the extent that they do not impair the object of the invention.

The composition of the present invention is readily facilitated by uniformly kneading all components in the composition with a suitable mixer, such as a kneader-mixer, a pressure kneader-mixer, a Ross mixer, a planetary mixer, a Hobart mixer, and the like. It can manufacture. When the composition of the present invention is used to coat various substrates, it may first be diluted with an organic solvent such as toluene or xylene to the desired concentration, as indicated by the coating apparatus.

Examples of substrates that can be used as substrates for coatings prepared from the compositions of the present invention include synthetic fibers such as polyamide fibers (e.g. nylon 6, nylon 66 and nylon 46), aramid fibers, polyester fibers (polyethylene terephthalate Wovens, nonwovens and knits made from polyetherimide fibers and sulfone fibers; Woven, nonwoven and knit made from natural fibers; Woven fabrics and knits made from inorganic fibers such as glass fibers and carbon fibers; Metals such as iron, aluminum, stainless steel, nickel, copper and chromium; Glass; quartz; magnetism; ceramic; Plastics such as epoxy resins, acrylic resins, polyethylene terephthalate resins, unsaturated polyester resins and polyamide resins; Natural and synthetic rubbers; And wood. The compositions of the present invention adhere particularly well to wovens and knits made from glass fibers, and to wovens, nonwovens and knits made from synthetic fibers, such as polyamide fibers, aramid fibers and polyester fibers.

To coat synthetic or glass fiber fabrics with the compositions of the present invention, liquid silicone rubber is first applied onto the fabric by any suitable means, and then the coated fabric is dried, for example in a hot air drying oven, and liquid silicone on the fabric substrate. Heat and cure the rubber. Preferably, the resulting coating is generally at most 200 g / m ² . The resulting coated fabric exhibits excellent flexibility, and the silicone rubber coating is integrated in secure bonding with synthetic and / or glass fiber fabrics and the like. The silicone rubber coated fabrics thus obtained are useful as electrical insulation, diaphragms, seals, tent cloths, automotive airbags, conduit lakes, medical devices and apparel materials. Coated fabrics made from the compositions of the present invention, such as cloth for automotive airbags, are not tacky on the surface of the coating and thus It is very easy to operate the stitching and other operations without spreading talc, calcium carbonate and the like, and thus there is no problem that the cured coating is stuck when folding or laminating to store the airbag.

Example

Hereinafter, the present invention is described by way of examples. All "parts" in the examples are by weight and the viscosity is at 25 ° C. Me is a methyl group and Vi is a vinyl group.

Example 1

Methylvinylpolysiloxane resin consisting of 100 parts of dimethylvinylsiloxy endblocked dimethylpolysiloxane having a viscosity of 2000 mPa · s was composed of SiO _4/2 units, Vi (Me) ₂ SiO _1/2 units and (Me) ₃ SiO _1/2 units ( Vinyl group content: 1.9% by weight, solid at room temperature), together with 30 parts of the furnace. Subsequently, 12 parts of fused silica having a specific surface area of 200 m ² / g, 5 parts of hexamethyldisilazane (used as a surface treating agent for fused silica) and 5 parts of water are added to the mixture. The components are mixed until uniformly dispersed and then the mixture is heated under vacuum to produce a liquid silicone rubber substrate having fluidity.

Subsequently, 0.5 part of a complex of chloroplatinic acid and divinyltetramethyldisiloxane (platinum concentration: 0.4% by weight), 0.4 part of 3,5-dimethyl-1-hexyn-3-ol, γ- 1 part glycidoxypropyltrimethoxysilane, ethyl polysilicate (average molecular formula: Si _p O _(p-1) (OC ₂ H ₅ ) _{(2p + 2)} , wherein p is an average of 5 and SiO ₂ Content is 40% by weight, viscosity is 5 mPa · s) 1 part and 0.5 part tetrabutyl titanate are added. These components are mixed until uniformly dispersed, the viscosity is 5 mPa · s and the organopolysiloxane of the average formula Me ₃ SiO (MeHSiO) ₆ (Me ₂ SiO) ₄ SiMe ₃ (silicon-bonded hydrogen atoms in this component) To a molar ratio of moles of alkenyl groups in the whole composition to 2: 1), and mixed uniformly to prepare a liquid silicone rubber coating composition. The viscosity of this composition is 26 mPa * s. The composition is sandwiched between two sheets of nylon 66 fiber fabric (210 denier) and placed on a flat table and the thickness is adjusted with an applicator in which the gap is adjusted so that the thickness of the coating is between 50 and 100 μm. It is then cured by heating in a 180 ° C. oven for 30 seconds or 1 minute, or in a 150 ° C. oven for 1 or 2 minutes. A 2.0 cm wide, 10 cm long sample piece of this product is cut and subjected to a peel test at a pulling rate of 50 m / min. A Scott flexure test is also performed, wherein one sheet of nylon 66 fabric (210 denier) is coated with the composition using a coater and the coating is heated and cured in a 150 ° C. oven to produce a silicone rubber coated cloth, Scott After testing for 1000 flex cycles at a compressive force of 19.6 N using a flexure tester, visually check for separation of the silicone rubber coating from the cloth surface. The adhesiveness of the coating surface is also checked by the finger feel.

Table 1 below shows the measurement results of these properties.

Comparative Example 1

The liquid silicone rubber coating composition is prepared in the same manner as in Example 1 except that no ethyl polysilicate is introduced into the composition. The properties of the resulting cured coatings prepared from these compositions are measured in the same manner as in Example 1. These results are also shown in Table 1.

Example 1 Comparative Example 1 Hardness of Silicone Rubber (JIS A) 50 52 Thickness of coating material (㎛) 75-110 70-120 Adhesive Strength: 180 ° C x 30 seconds (N / cm) 7.5 3.2 Adhesive strength: 180 ° C. × 1 minute (N / cm) 7.9 7.8 Adhesive strength: 150 ° C. × 1 minute (N / cm) 7.6 2.0 Adhesive Strength: 150 ° C x 2 minutes (N / cm) 8.0 7.7 Scott Bend Exam Pass Pass Sticky none none

The adhesive strength of the resulting cured product of Example 1 after only 30 seconds in a oven at 180 ° C. and 1 minute when the temperature is 150 is the cured product after the residence time for 1 minute and 2 minutes respectively. It is noted that, although only slightly less, it is several times better than the adhesive strength of the cured product based on the composition of Comparative Example 1 except for the ethyl polysilicate contained in the composition used in Example 1.

Example 2

_{Methylvinylpolysiloxane} resin consisting of 100 parts of dimethylvinylsiloxy endblocked dimethylpolysiloxane having a viscosity of 1200 mPa · s consisting of SiO _4/2 units, Vi (Me) ₂ SiO _1/2 units and (Me) ₃ SiO _1/2 units ( It is placed in a furnace mixer with 15 parts of vinyl group content: 5 wt%, viscosity: 230 mPa · s) and 20 parts of fused silica having a specific surface area of 200 m ² / g, pretreated with hexamethyldisilazane. The components are mixed until uniformly dispersed to produce a liquid silicone rubber substrate having fluidity.

Subsequently, 0.5 part of a complex of platinum chloride and divinyl tetramethyldisiloxane (platinum concentration: 0.4% by weight), 1 part of tetrabutyl titanate, ethyl polysilicate (average molecular formula: Si _p O _{( p-1)} (OC ₂ H ₅ ) _{(2p + 2)} , wherein p is an average of 5 and SiO ₂ Content is 40% by weight, viscosity is 5 mPa · s) 5 parts, 0.5 part of octamethyltetracyclosiloxane and 0.2 part of benzotriazole are added. Thereafter, the viscosity was 21 mPa · s and 3.5 parts of methylhydrogenpolysiloxane of the average formula Me ₃ SiO (MeHSiO) ₂₅ SiMe ₃ (moles of silicon-bonded hydrogen atoms in the corresponding components versus moles of alkenyl groups contained in the total composition) To a ratio of 1.7: 1), and mixed uniformly to prepare a liquid silicone rubber coating composition.

Subsequently, an untreated glass fiber braided electric wire (braiding the glass fiber on a silicone rubber coated electric wire) was introduced into a container filled with the composition, and then a wire through hole in the covering jig (the diameter of this wire through hole was Pass through a diameter greater than the diameter of the braided wire), coated with a certain amount of the liquid silicone rubber coating composition described above, and then the product is introduced into a heating oven and heat cured at 180 ° C. for a specific time to A glass fiber braided electric wire is obtained.

The wire is cut with scissors, and the cut end is visually checked for wear of the glass fiber. This evaluates the cohesiveness of the glass fibers and also evaluates the adhesion of the composition to the glass fibers. Tackiness is evaluated by touch. Table 2 below shows the measurement results of these properties.

Comparative Example 2

The liquid silicone rubber coating composition is prepared in the same manner as in Example 2 except that no ethyl polysilicate is introduced into the composition. The properties of the resulting cured coatings prepared from these compositions are measured in the same manner as in Example 2. These results are also shown in Table 2.

Example 2 Comparative Example 2 Curing time (minutes) 3 5 10 3 5 10 Sticky none none none has exist Slightly sticky none Cohesive Good Good Good Abrasion fiberglass Slightly worn fiberglass Good

Example 3

100 parts of dimethylvinylsiloxy endblocked dimethylpolysiloxane having a viscosity of 12,000 mPa · s were placed in a furnace mixer with 20 parts of fused silica having a specific surface area of 200 m ² / g and treated with hexamethyldisilazane, and the components were uniformly Mix until dispersed. 20 parts of methylvinylpolysiloxane resin (vinyl group content: 1.9% by weight, solid at room temperature) gradually consisting of SiO _4/2 units, Vi (Me) ₂ SiO _1/2 units and (Me) ₃ SiO _1/2 units And mixed until uniformly dispersed to prepare a liquid silicone rubber substrate having fluidity.

의 오가노실록산 화합물(여기서, Me는 메틸 그룹이고, Vi는 비닐 그룹이다) 1부, 메틸 폴리실리케이트(평균 분자식: Si_pO_(p-1)(OCH₃)_(2p+2), 이때, p는 평균 4이고, SiO₂ 함량은 52중량%이고, 점도는 7mPa·s이다) 1부 및 디이소프로폭시비스(에틸 아세토아세테이트)티탄 0.5부를 가한다. 이 성분들을 균일하게 혼합한다. 이 액체 실리콘 고무 조성물의 점도는 18mPa·s이다. 나일론 66 섬유 직물을 실시예 1과 동일한 방식으로 당해 조성물로 피복시키고, 접착력, 박막 피복능 및 점착성을 유사하게 측정한다. 하기 표 3은 이러한 특성들의 측정 결과를 나타낸다.
Subsequently, 100 parts of such a liquid silicone rubber substrate had a viscosity of 21 mPa · s and 1.5 parts of methylhydrogenpolysiloxane of average formula Me ₃ SiO (MeHSiO) ₂₅ SiMe ₃ (mole number of silicon-bonded hydrogen atoms in the corresponding component versus the premise composition). In an amount such that the molar number of alkenyl groups contained is 2: 1), 0.3 part of a complex of chloroplatinic acid and divinyltetramethyldisiloxane (platinum concentration: 0.4% by weight), methyltris (3-methyl-1- Butyne-3-oxy) silane 0.05part, average chemical formula

1 part of an organosiloxane compound, wherein Me is a methyl group and Vi is a vinyl group, methyl polysilicate (average molecular formula: Si _p O _(p-1) (OCH ₃ ) _{(2p + 2)} , wherein p is an average of 4 and SiO ₂ The content is 52% by weight, the viscosity is 7 mPa · s) and 1 part of diisopropoxybis (ethyl acetoacetate) titanium are added. Mix these ingredients uniformly. The viscosity of this liquid silicone rubber composition is 18 mPa · s. Nylon 66 fiber fabrics are coated with the composition in the same manner as in Example 1, and the adhesion, thin film coverage and tack are similarly measured. Table 3 below shows the measurement results of these properties.

Comparative Example 3

The liquid silicone rubber coating composition is prepared in the same manner as in Example 3 except that no methyl polysilicate is introduced into the composition. The properties of the resulting cured coatings prepared from this composition are measured in the same manner as in Example 3. These results are also shown in Table 3.                     

Example 3 Comparative Example 3 Hardness of Silicone Rubber (JIS A) 45 47 Thickness of coating material (㎛) 50-90 50-95 Adhesive strength: 150 ° C. × 1 minute (N / cm) 4.5 1.5 Adhesive Strength: 150 ° C x 2 minutes (N / cm) 5.6 4.3 Scott Bend Exam Pass Pass Sticky none none

The liquid silicone rubber coating composition of the present invention contains alkyl silicate or alkyl polysilicate (G), in addition to organopolysiloxane resin (B) and organotitanium compound (F), and optionally contains an epoxy group-containing organosilicon compound (H). It may further contain and is well suited for forming thin films on substrates such as synthetic and / or glass fiber fabrics and exhibits good adhesion after heat treatment for a very short time. Fabrics coated with the liquid silicone rubber coating composition of the present invention are also useful as electrical insulation, diaphragms, seals, tent cloths, automotive airbags, conduit lakes, medical devices, and garments.

Claims (9)

(A) diorganopolysiloxanes having a viscosity at 25 ° C. of 100 to 100,000 mPa · s and containing at least two alkenyl groups per molecule, (B) organopolysiloxane resin, (C) inorganic fillers, (D) at least two silicon-bonded hydrogens per molecule in an amount such that the ratio of the number of mols of silicon-bonded hydrogen atoms in the component to the number of mols of alkenyl groups contained in the total composition is from 0.6: 1 to 20: 1. Organopolysiloxanes containing atoms, (E) platinum group catalysts and (F) contains an organotitanium compound, (G) at least one alkyl silicate, alkyl polysilicate, or mixtures thereof. The method of claim 1, (A) 100 parts by weight of diorganopolysiloxane having a viscosity at 25 ° C. of 100 to 100,000 mPa · s and containing at least two alkenyl groups per molecule, (B) 5 to 100 parts by weight of the organopolysiloxane resin, (C) 5 to 100 parts by weight of the inorganic filler, (D) at least two silicon-bonded hydrogens per molecule in an amount such that the ratio of the number of mols of silicon-bonded hydrogen atoms in the component to the number of mols of alkenyl groups contained in the total composition is from 0.6: 1 to 20: 1. Organopolysiloxanes containing atoms, (E) platinum group catalyst in an amount corresponding to 0.1 to 500 parts by weight per 1,000,000 parts by weight of component (A), (F) 0.1 to 5 parts by weight of the organotitanium compound and (G) A liquid silicone rubber coating composition comprising 0.1 to 20 parts by weight of alkyl silicate or alkyl polysilicate. The liquid silicone rubber coating composition according to claim 1 or 2, wherein the organopolysiloxane resin is a vinyl group-containing organopolysiloxane resin. The liquid silicone rubber coating composition according to claim 1 or 2, wherein the organotitanium compound is an organotitanate ester or a titanium chelate. 3. The liquid silicone rubber coating composition according to claim 1, wherein component (G) is an alkyl polysilicate whose average formula corresponds to formula (1): 4. Formula 1 Si _p O _(p-1) (OR ^b ) _{(2p + 2)} In Chemical Formula 1, p is an integer from 1 to 20, R ^b is an alkyl group. The liquid silicone rubber coating composition according to claim 1, further comprising component (H) comprising 0.1 to 20 parts by weight of an epoxy group-containing organosilicon compound. 7. The epoxy group-containing organosilicon compound according to claim 6, wherein the epoxy group-containing organosilicon compound contains an epoxy group-containing organoalkoxysilane, an epoxy group-containing organopolysiloxane comprising a silicon-bonded vinyl group and an alkoxy group, and an epoxy group-containing silicon-bonded hydrogen atom. A liquid silicone rubber coating composition characterized in that it is an epoxy group-containing organopolysiloxane comprising an organopolysiloxane or a silicon-bonded hydrogen atom and an alkoxy group. 8. The method of claim 7, wherein the epoxy group-containing organosilicon compound is selected from γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane and compounds of the formula Liquid silicone rubber coating composition.

In the above formula, Me is a methyl group, Vi is a vinyl group. 3, The compound according to claim 1 or 2, which is 3-methyl-1-butyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, 3-methyl-3-pentene-1- Liquid silicone rubber coating composition further comprising at least one curing retardant component (J) selected from 5-dimethyl-3-hexene-1-yne, tetramethyltetrahexenylcyclotetra-siloxane and benzotriazole. .