JP3248322B2 - Film-forming silicone resin composition and molded silicone resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to electrical and electronic equipment, OA
The present invention relates to a film-forming silicone resin composition and a silicone resin molded product useful in various fields such as equipment, automobiles, precision equipment, and building materials.

[0002]

2. Description of the Related Art Silicone resin is excellent in heat resistance, cold resistance, electric insulation, weather resistance, water repellency and the like. Used for intermediate and coil insulation, layer insulation and earth insulation of electric appliances, etc., laminated boards based on glass fiber and asbestos are used as throat insulators for class H insulation equipment, terminal boards, microwave shielding boards for microwave ovens And various other heat-resistant insulating materials. Furthermore, the combination with mica is a support plate of nichrome wire such as hair dryer, iron, toaster,
Used for various heat-resistant applications such as heat-resistant washers and partition plates for microwave ovens.

[0003] In recent years, while these uses have been expanding, they have also been developed as functional beauty dressing (protection) materials for building materials and office equipment by utilizing the transparency, water repellency, and weather resistance of silicone resins. Has begun. However, it is difficult for these silicone resins to adhere to paints for printing or decoration, and their use is currently limited.

[0004] The present invention has been made in view of the above circumstances,
Provided are a film-forming silicone resin composition to which a hydroxyl group-reactive coating can be adhered, and a molded silicone resin product having a coating of the coating formed thereon.

[0005]

The present inventors have conducted intensive studies to achieve the above object, and as a result, the following general formula (1): R _n (OH) _m SiO _{(4-nm) / 2} (1) (wherein R is the same or different unsubstituted or substituted monovalent hydrocarbon group, and 0.5 to 30 mol% of all Rs are alkenyl groups; ≤n + m≤2, 0.005≤
It is a positive number satisfying m / (n + m) ≦ 0.2. The silicone resin composition of the addition reaction curing agent or the organic peroxide curing agent containing an organopolysiloxane as a main component represented by the above) has a certain amount of silanol groups in the organopolysiloxane. The inventors have found that the reactivity is maintained and the adhesion to various hydroxyl-reactive ink materials is facilitated, and the present invention has been accomplished.

Accordingly, the present invention comprises an organopolysiloxane represented by the above general formula (1) and a curing agent for addition reaction or an organic peroxide curing agent.
A film-forming silicone resin composition capable of adhering a hydroxyl-reactive paint having an IS-A hardness of 80 or more, and the above-mentioned silicone resin composition on which a coat of a hydroxyl-reactive paint is formed. Provided is a silicone resin molded body.

Hereinafter, the present invention will be described in more detail. The silicone resin composition of the present invention comprises an organopolysiloxane represented by the following general formula (1) as a main component. R _n (OH) _m SiO _{(4-nm) / 2} ... (1)

Here, R preferably has 1 to 20 carbon atoms,
Particularly preferred are the same or different unsubstituted or substituted monovalent hydrocarbon groups having 1 to 10 carbon atoms. Specific examples of such hydrocarbon groups include alkyl groups such as methyl, ethyl and propyl. , A saturated hydrocarbon group such as a cycloalkyl group, an aryl group such as a phenyl group and a tolyl group, a vinyl group,
Examples include alkenyl groups such as allyl group, propenyl group and butenyl group, halogen-substituted hydrocarbon groups such as 3,3,3-trifluoropropyl group, and cyano-substituted hydrocarbon groups. In this case, it is necessary that 0.5 to 30 mol%, preferably 1 to 20 mol% of all Rs are alkenyl groups. If the content of the alkenyl group is less than 0.5 mol%, the required hardness of the silicone resin cannot be obtained,
If it is larger than the number, the number of crosslinking points is too large, and the silicone resin becomes brittle. Further, n and m are 1 ≦ n + m ≦ 2, and the content of the silanol group is 0.5 to 20% by mole of all the organic groups.
(0.005 ≦ m / (n + m) ≦ 0.2), preferably 1 to 10 mol%. If the content of the silanol group is less than this, sufficient adhesion to the hydroxyl-reactive coating cannot be obtained, and if it exceeds 20 mol%, the resin becomes unstable due to a dehydrogenation reaction.

Such an organopolysiloxane can be produced by a known method, for example, co-hydrolysis of dimethylchlorosilane, phenyltrichlorosilane, methylvinyldichlorosilane, or dimethyldimethoxysilane, phenyltrimethoxysilane, vinyltrimethoxysilane. It can be obtained by co-hydrolysis of silane under an alkali or acid catalyst. The content of the silanol group can be adjusted by the concentration of the catalyst, the reaction temperature, and the like. Further, the generated silanol group can be modified with a silylating agent such as trimethylchlorosilane or hexamethyldisilazane in the next step.

[0010] The silicone resin composition of the present invention can be used as an addition-curable silicone resin composition containing an addition reaction curing agent or an organic peroxide-curable silicone resin composition containing an organic peroxide curing agent. Can be formed.

In this case, the addition-curable silicone resin composition used in the present invention comprises (a) an organopolysiloxane represented by the above formula (1), (b) an organohydrogenpolysiloxane liquid at room temperature, and (c) The addition reaction catalyst is a main component, and if necessary, in order to adjust the hardness of the silicone resin composition to 80 or more in JIS-A hardness, or to adjust the viscosity or the like, (d) liquid at room temperature or It is preferable to add an organopolysiloxane having a raw rubber shape and containing two or more alkenyl groups in one molecule.

Here, the organohydrogenpolysiloxane of the component (b) includes a methylhydrogenpolysiloxane having a trimethylsiloxy group at both ends and a dimethylsiloxane / methylhydrogenpolysiloxane copolymer having a trimethylsiloxy group at both ends. Terminal dimethyl hydrogen siloxy group-blocked dimethyl siloxane,
Both ends dimethyl hydrogen siloxy group-blocked dimethyl siloxane / methyl hydrogen polysiloxane copolymer, both ends trimethyl siloxy group-blocked methyl hydrogen polysiloxane / diphenyl siloxane copolymer, both ends trimethyl siloxy group-blocked methyl hydrogen polysiloxane Diphenylsiloxane / dimethylsiloxane copolymer, (CH ₃ ) ₂ HSiO _1/2 unit and S
a copolymer consisting of iO _4/2 units, (CH ₃ ) ₃ SiO _1/2
A copolymer composed of units, (CH ₃ ) ₂ HSiO _1/2 units and SiO _4/2 units, (CH ₃ ) ₂ HSiO _1/2 units and SiO
Copolymers composed of _4/2 units and (C ₆ H ₅ ) ₃ SiO _3/2 units are _exemplified .

The amount of the organohydrogenpolysiloxane is as follows:
The amount is preferably 1 to 50 parts, particularly preferably 5 to 30 parts with respect to 00 parts (parts by weight, hereinafter the same). If the amount is less than this, sufficient hardness may not be obtained as a silicone resin, and if it is more than this, the cured product may become brittle, and sufficient strength may not be obtained.

Examples of the addition reaction catalyst of component (c) include platinum black, platinous chloride, chloroplatinic acid, a reaction product of chloroplatinic acid with a monohydric alcohol, a complex of chloroplatinic acid with olefins, platinum bis Examples include acetoacetate, a palladium-based catalyst, and a rhodium-based catalyst. The amount of the addition reaction catalyst can be a catalytic amount.

The liquid or raw rubber-like organopolysiloxane containing at least two alkenyl groups in one molecule of the component (d) includes dimethylpolysiloxane having dimethylvinylsilyl groups at both ends and dimethylvinylsilyl groups at both ends. Polysiloxane / methylvinylsiloxane copolymer, both ends dimethylvinylsilyl group-blocked dimethylpolysiloxane / diphenylsiloxane / methylvinylsiloxane copolymer, both ends methylphenylvinylsilyl group-blocked dimethylpolysiloxane / diphenylsiloxane / methylvinylsiloxane Polymers and methyl (3,3,3-trifluoropropyl) polysiloxane having a dimethylvinylsilyl group at both ends are exemplified.

The amount of the organopolysiloxane is 100 parts or less based on 100 parts of the organopolysiloxane of the component (a), especially 5 parts so as not to impair the strength of the resin.
It is preferable to set it to 0 parts or less.

Further, besides the above-mentioned components, a filler may be blended in order to control the fluidity or to improve the mechanical strength of the molded product. If necessary, a pigment, a heat-resistant agent and a flame retardant may be added. , A plasticizer and the like. .

Examples of the filler include reinforcing fillers such as precipitated silica, fumed silica, calcined silica and fumed titanium oxide, ground quartz, diatomaceous earth, asbestos, aminosilicic acid, iron oxide, zinc oxide, calcium carbonate and the like. Non-reinforcing fillers. These fillers may be used as they are, or may be surface-treated with an organosilicon compound such as hexamethyldisilazane, trimethylchlorosilane, or polymethylsiloxane.

On the other hand, the organic peroxide-curable silicone rubber composition used in the present invention comprises (a) an organopolysiloxane represented by the above formula (1), and (e) a catalytic amount of an organic peroxide as a main component. In order to adjust the hardness of the silicone resin composition to the above-mentioned values or to adjust the viscosity or the like, if necessary, (d) liquid or raw rubber at room temperature may be used.
It is preferable to add an organopolysiloxane containing two or more alkenyl groups in the molecule.

Here, the organic peroxide of the component (e) is
The component (a) is used as a catalyst for accelerating the crosslinking reaction of the component, and examples thereof include the following, but are not limited thereto.

[0021]

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The amount of the organic peroxide to be added can be appropriately selected according to the curing speed, but is usually from 0.1 to 1 based on 100 parts of the organopolysiloxane (a).
It is preferably 0 parts, especially 0.2 to 2 parts.

As the liquid or raw rubber-like organopolysiloxane containing at least two alkenyl groups in one molecule of the component (d), dimethylpolysiloxane having dimethylvinylsilyl groups at both ends and dimethyl having dimethylvinylsilyl groups at both ends can be used. Polysiloxane / methylvinylsiloxane copolymer, dimethylvinylsilyl group-terminated dimethylpolysiloxane / diphenylsiloxane / methylvinylsiloxane copolymer, trivinylsiloxy-terminated dimethylpolysiloxane at both ends, dimethylvinylsiloxy-terminated dimethyl at both ends Polysiloxane / methylvinylsiloxane copolymer, both ends methylphenylvinylsilyl group-blocked dimethylpolysiloxane / diphenylsiloxane / methylvinylsiloxane copolymer, both ends dimethylvinylsilyl group-blocked methyl 3,3,3-trifluoropropyl), polysiloxane and the like.

The amount of the organopolysiloxane is 100 parts or less based on 100 parts of the organopolysiloxane of the component (a), especially 5 parts so as not to impair the strength of the resin.
It is preferable to set it to 0 parts or less.

Further, in addition to the above-mentioned components, the same fillers as described above may be blended in order to control the fluidity and to improve the mechanical strength of the molded product as in the case of the addition-curable silicone resin composition. And, if necessary, pigments, heat-resistant agents,
You may mix a flame retardant, a plasticizer, etc.

Further, depending on the use, in order to adjust the hardness and viscosity, reactive vinyl monomers and oligomers shown below may be added in an amount that does not impair the heat resistance, weather resistance, electrical properties, etc. of the silicone. .

[0027]

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[0028]

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The above silicone resin composition is molded by a known molding method according to a desired molded body, and then cured.
A cured product having an IS-A hardness of 80 or more is obtained. In this case, the curing conditions can be appropriately selected, but are usually from room temperature to 250
C, for 30 seconds to 90 minutes.

The coating material (ink material) to be adhered to the silicone resin molded body may be any material as long as it is cured by a hydroxyl group participating in the reaction, and examples thereof include urea resin, melamine resin, epoxy resin and polyurethane. It is listed as. These resin coatings may be used alone or in combination of two or more. Further, an alkyd resin coating, an acrylic resin coating, a phenol resin coating, a vinyl chloride resin coating, a polyester resin coating, or the like may be used in combination.

The urea resin paint is prepared by dissolving a urea resin obtained by reacting urea and aldehyde under weak alkalinity in a solvent such as xylene, mineral spirit, or thinner, and baking at 90 to 140 ° C. or acidifying. A cured film can be obtained at room temperature by adding a catalyst. In particular, the addition of an acidic catalyst also increases the reactivity of the silanol groups of the silicone resin, so that a strong adhesive surface can be obtained.

The melamine resin paint is generally obtained by diluting a resin prepared by subjecting melamine and formaldehyde to methylolation in an alkaline state and then adding alcohol to etherify the resin. Since a melamine resin becomes a hard and brittle film when used alone, it is usually used by blending an alkyd resin, an epoxy resin, a thermosetting acrylic resin or the like.

As the epoxy resin paint, a condensation product of bisphenol A and epichlorohydrin is mainly used, but a phenolic compound such as novolak,
In some cases, epoxy groups are introduced into unsaturated groups such as cyclopentadiene and polybutadiene, and these are diluted with various organic solvents such as xylene, methyl ethyl ketone, and ethyl acetate, and the resin itself has low viscosity. They are solventless and may be used as aqueous emulsions. Usually, amine-based curing agents such as triethylenetetramine, metaphenylenediamine, diethylenetriamine, and dicyanodiamide, or acid anhydride-based curing agents such as phthalic anhydride, methylnadic anhydride, and pyromellitic anhydride are used. These curing agents also have the effect of increasing the reactivity of the silanol groups of the silicone resin, and also have the function of strengthening the adhesion of the paint to the silicone resin.

The polyurethane resin paint is obtained by diluting a resin obtained by a reaction between a polyhydroxy compound (polyol) and an isocyanate with a solvent, and there are various curing types. Particularly, a strong adhesion to the silicone resin of the present invention is obtained. What is obtained is a coating composed of a prepolymer and an amine-based catalyst, and a polyol and a polyisocyanate / polyester, all of which have high reactivity and can obtain strong adhesion to the silicone resin of the present invention.

An amine silane coupling agent, a (meth) acrylic silane coupling agent, an epoxy silane coupling agent, or a partially reacted product thereof is added to each of these various resin coatings as described below. By adding 0.01 to 20 parts, and preferably 0.1 to 10 parts, to parts, even stronger adhesion can be obtained.

[0036]

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The thickness of the coating film is not limited at all, but is usually 5 to 500 μm.

[0038]

According to the present invention, it is possible to obtain a silicone resin molded article in which a coating film is adhered and firmly formed on the surface. Therefore, the present invention provides various panels, switches, microwaves,
Heat-resistant decorative protective coat for household appliances such as dryers,
It is effectively applied to switches such as calculators, telephones, and computer remote controls, protective coats for building materials, decorative coats for furniture, and the like.

[0039]

EXAMPLES The present invention will be described below in detail with reference to examples and comparative examples, but the present invention is not limited to the following examples.

Example 1 100 parts of an organopolysiloxane represented by the following average composition formula (2), 10 parts of an organohydrogenpolysiloxane represented by the following average composition formula (3), and a solution of chloroplatinic acid in isopropanol (platinum) (Content 0.2%) were mixed to obtain a silicone resin composition (A).

[0041]

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The silicone resin composition (A) was applied with a thickness of 2
mm, heat-cured at 150 ° C for 10 minutes, and further post-cured at 180 ° C for 1 hour.
A silicone cured product (A) having an A hardness of 95 was obtained.

An alkyd melamine resin paint composed of 25.0 parts of a coloring pigment having the following composition, 51.0 parts of an alkyd resin varnish, 19.0 parts of a melamine resin varnish, and 5.0 parts of a solvent was coated on the cured silicone material (A). The composition was applied so as to have a thickness of 30 to 50 μm, and a cured film was formed at 130 ° C. for 20 minutes.

[Example 2] On the cured silicone material (A) of Example 1, a main component consisting of 18.0 parts of a coloring pigment having the following composition, 52.0 parts of an acrylic resin varnish for urethane, and 16.0 parts of a solvent. And a mixture of a curing agent composed of polyisocyanate in a ratio of base agent / curing agent = 6/1 having a thickness of 30%.
The coating and drying were repeated several times to a thickness of
After-curing was performed at 00 ° C. for 30 minutes to form a cured film.

Example 3 On the silicone cured product (A) of Example 1, the following compounding composition Colored pigment 30.0 parts Acrylic resin varnish 42.0 parts Melamine resin varnish 15.0 parts Epoxy resin varnish 3 0.0 part of a solvent 10.0 parts of an acrylic melamine resin paint 100 parts
-A mixture obtained by adding and mixing 0.2 parts of aminopropyltriethoxysilane is applied so as to have a thickness of 30 to 50 µm.
Heating was performed at 20 ° C. for 30 minutes to form a cured film.

Comparative Example 1 100 parts of an organopolysiloxane represented by the following average composition formula (4), and the same organohydrogenpolysiloxane (3) as in Example 1
And 1.2 parts of an isopropanol solution of chloroplatinic acid (platinum content: 0.2%) to obtain a silicone resin composition (B). This was cured in the same manner as in Example 1 to obtain a cured silicone resin (B).

[0047]

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On the silicone cured product (B), the alkyd melamine resin paint of Example 1 was similarly coated with 30 to 50 μm.
m and a cured film was formed at 130 ° C. for 20 minutes. However, the cured film of the paint peeled off from the silicone resin during curing.

Comparative Example 2 On the cured silicone resin (B) obtained in the same manner as in Comparative Example 1, the polyisocyanate resin paint of Example 2 was applied and cured in the same manner. Was formed. However, the cured film of the paint peeled off from the silicone resin during curing.

Comparative Example 3 On the silicone resin cured product (B) obtained in the same manner as in Comparative Example 1, 100 parts of the acrylic melamine resin paint of Example 3 was added with γ-aminopropyltriethoxysilane 0.1 part. Two parts of the mixture were mixed and applied and cured in the same manner as in Example 3 to obtain a cured film.

Next, integral molding of silicone resin and paint
Each of Examples 1 to 3 and Comparative Example 3 in which
The film was subjected to a wear resistance test. The results are shown in Table 1.
You. Friction frequency test As shown in FIG. 1, a marker formed on the silicone cured product 2
Apply a load of 300 g 4 to the specified location on the surface of the King coating 1
Scratched with girder stainless steel tool 3, silicon
Of the marking film 1 from the cured product 2
The number of times until 1 itself was destroyed was measured.

[0052]

[Table 1]

From the results shown in Table 1, it was confirmed that the silicone resin molded product of the present invention can form a coating film with good adhesion.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a friction frequency test.

[Explanation of symbols]

 1 Marking film 2 Silicone cured product

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁷ identification symbol FI C09D 183/06 C09D 183/06 183/07 183/07 (58) Investigated field (Int.Cl. ⁷ , DB name) C08L 83 / 05-83/07 C08J 7/04 CFH C08K 5/14

Claims (2)

(57) [Claims] 1. The following general formula (1): R _n (OH) _m SiO _{(4-nm) / 2} (1) wherein R is the same or different unsubstituted or substituted monovalent hydrocarbon group. However, 0.5 to 30 mol% of all Rs are alkenyl groups, and n and m are 1 ≦ n + m ≦ 2, 0.005 ≦
It is a positive number satisfying m / (n + m) ≦ 0.2. ) And a curing agent for addition reaction or an organic peroxide curing agent,
A film-forming silicone resin composition having an IS-A hardness of 80 or more, to which a hydroxyl-reactive coating can be adhered. 2. A silicone resin molded article of the silicone resin composition according to claim 1, wherein a coating film of a hydroxyl group reactive paint is formed.