JPH06172654A - Fluorine-containing organopolysiloxane composition - Google Patents

Abstract

PURPOSE:To provide the subject composition containing a specified organopolysiloxane, a specific fluorine-containing alkoxysilane, a specified organohydrogenpolysiloxane, platinum, etc., in a specified ratio, excellent in electric insulation and heat resistance and useful for a packing, etc. CONSTITUTION:The objective composition is composed of (A) an alkenyl group- containing organopolysiloxane containing two or more alkenyl groups bonded to a silicon atom in one molecule and one or more fluorine-containing substituent groups selected from formulae I to V {(n) is 1 to 8; CnF2n+1 [(n) is 1 to 10]} and bonded to a silicon atom in one molecule, (B) a fluorine-containing alkoxysilane of formula VI (Rf is a univalent perfluoropolyether, etc.; R<1> is a univalent hydrocarbon), (C) an organohydrogenpolysiloxane containing three or more H bonded to a silicon atom in one molecule and (D) platinum or a platinum group compound. The amount of identicalSi-H groups in the component (C) is 0.5 to 5.0mol based on 1mol aliphatic unsaturated group in this composition.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention provides a fluorine-containing organopolysiloxane composition, particularly a silicone rubber elastic body which has excellent adhesiveness and adhesion to various materials and is highly elastic when cured. The present invention relates to a fluorine-containing organopolysiloxane composition.

[0002]

2. Description of the Related Art Various kinds of fluorine-containing silicone rubber are known to be known, and these have excellent properties such as electric insulation, heat resistance, cold resistance, weather resistance and the like, as well as solvent resistance. , Water repellency, oil repellency,
It is said that it is characterized by having excellent surface characteristics such as releasability.

However, the known fluorine-containing silicone rubber has a drawback that it has poor adhesiveness to various equipments because of its excellent surface characteristics as described above, and a countermeasure against this is strongly demanded.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a fluorine-containing organopolysiloxane composition which solves the above-mentioned drawbacks, which comprises A) at least two alkenyl groups bonded to a silicon atom in one molecule. And having in one molecule the following formulas (1) to (5)

[Chemical 5] (N = 1 to 8)

[Chemical 6] (N = 1 to 8)

[Chemical 7] (N = 1 to 8)

[Chemical 8] (N = 1 to 8 integer) C _n F _{2n + 1} CH ₂ CH ₂ --- (5) For silicon atom selected from (n = 1 to 10 integer) An alkenyl group-containing organopolysiloxane having at least one bound fluorine-containing substituent, B) General formula R _f CH ₂ CH ₂ Si
Fluorine-containing alkoxysilane represented by (OR) ₃ (where R _f is a monovalent perfluoropolyether group or a monovalent perfluoroalkyl group, and R is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 8 carbon atoms) , C) an organohydrogenpolysiloxane having at least three hydrogen atoms (≡Si—H groups) bonded to a silicon atom in one molecule, D) platinum or a platinum group compound, and The amount of ≡Si—H groups is 0.5 to 5.0 mol per 1 mol of the aliphatic unsaturated groups in the composition.

[0005]

Means for Solving the Problems That is, the present inventor has developed a fluorine-containing organopolysiloxane composition exhibiting excellent adhesion and adhesion to various materials without impairing the various properties of the fluorine-containing silicone rubber. As a result of various investigations so far, alkenyl-containing organopolysiloxanes containing a fluorine-containing substituent selected from the above formulas (1) to (5), and fluorine-containing alkoxysilanes represented by the above general formula, and organohydrogenpolysiloxanes. When platinum or a platinum group compound as an addition reaction catalyst is added to an addition reaction type organopolysiloxane composition composed of siloxane, the compound is cured by an addition reaction to form a silicone rubber, which has processability and adhesion. It has been found that the material has excellent properties, and it has a low moisture permeability, so it is a part of the electrical and electronic fields. Ring, sealing material, and completed the present invention to confirm that it is useful as a coating material. This will be described in more detail below.

[0006]

The present invention relates to a fluorine-containing organopolysiloxane composition, which comprises A) the above formulas (1) to
An organopolysiloxane having a fluorine-containing substituent represented by (5) and at least two alkenyl groups, B) a general formula R _f CH ₂ CH ₂ Si (OR) ₃ (R _f and R are the same as above) It is composed of a fluorine-containing alkoxysilane shown below, C) an organohydrogenpolysiloxane, D) platinum or a platinum group compound, and these are various materials without impairing the properties of conventionally known fluorine-containing silicone rubbers. The silicone rubber elastic body exhibits excellent adhesiveness and adhesion, and when cured, gives a silicone rubber elastic body having excellent elasticity.

The alkenyl group-containing organopolysiloxane as the component A) constituting the fluorine-containing organopolysiloxane composition of the present invention is a linear fluorine-containing organopolysiloxane which is a base polymer in the composition of the present invention. This organopolysiloxane has the following general formula (a)

[Chemical 9] (Here, R ² and R ³ are unsubstituted or substituted 1 to 8 carbon atoms.
A valent hydrocarbon group, R ⁴ is a fluorine-containing substituent represented by the above formulas (1) to (5). ) And a general formula (b).

[Chemical 10] (Here, R ² is the same as above, R ⁵ is an unsaturated monovalent hydrocarbon group)
And a general formula (c)

[Chemical 11] The cyclotrisiloxane represented by

[Chemical 12] It can be obtained by coexisting with divinyldisiloxane represented by and copolymerizing with an acid or an alkali.

[Chemical 13] It can also be obtained by polymerizing with a silanolate catalyst such as an organopolysiloxane represented by (R ² is the same as above, M is an alkali metal).

In the above general formula, R ¹ , R ² ,
R ³ is an alkyl group such as a methyl group, an ethyl group, an isopropyl group or a butyl group, a cycloalkyl group such as a cyclohexyl group or a cyclopentyl group, an aryl group such as a phenyl group, a tolyl group or a xylyl group, a benzyl group or a phenylethyl group. Such as aralkyl groups, chloromethyl group, chloropropyl group, chlorohexyl group, 3,3,3-trifluoropropyl group in which some or all of the hydrogen atoms bonded to these carbon atoms are replaced with halogen atoms, cyano groups, etc. Group, a carbon number of 1 selected from a 2-cyanoethyl group, etc.
8 is an unsubstituted or substituted monovalent hydrocarbon group, and R ⁴ is an unsaturated monovalent hydrocarbon group such as a vinyl group, an allyl group or an ethynyl group.

Examples of the acid or alkali as a polymerization catalyst for obtaining the above-mentioned base polymer include alkali hydroxides such as lithium hydroxide and sodium hydroxide, and alkalis such as lithium siliconate, sodium siliconate and potassium siliconate. Quaternary salt hydroxides such as siliconate, tetrabutylphosphine hydroxide and tetraammonium hydroxide, the following structural formula

[Chemical 14] Examples thereof include 5-coordinate silicon compounds represented by, sulfuric acid, and sulfonic acids such as trichloromethanesulfonic acid.

Further, the fluorine-containing alkoxysilane as the component B) constituting the fluorine-containing organopolysiloxane composition of the present invention acts as an adhesion aid in the composition of the present invention, which has the general formula R _f CH ₂ CH ₂ Si (OR ¹ )
₃ (R _f and R ¹ are the same as above). R _{f in} this formula is a monovalent perfluoropolyether or a monovalent perfluoroalkyl group.

[Chemical 15]

[Chemical 16]

[Chemical 17]

[Chemical 18] Perfluoropolyether groups such as CF ₃ , C ₆
F ₁₃ -, and perfluoroalkyl such as C ₈ F ₁₇ is illustrated.

The B component is represented by R represented by the general formula (d).
It can be synthesized from a known method by using fluorine trichlorosilane represented by _f CH ₂ CH ₂ SiCl ₃ as a starting material.

[Chemical 19]

[Chemical 20] Examples include CF ₃ CH ₂ CH ₂ Si (OCH ₃ ) ₃ and C ₈ F ₁₇ CH ₂ CH ₂ Si (OC ₂ H ₅ ) ₃ .

If the amount of this component B) to the component A) is too small, the adhesiveness of this composition will be insufficient, and if it is too large, its heat resistance, compression set characteristics, etc. will deteriorate. 0.01 to 100 parts by weight of component A)
It may be in the range of 30 parts by weight, preferably in the range of 0.05 to 15 parts by weight, but in order to obtain a uniform cured product of this component B) and to keep the fluidity of this composition from being impaired. It is preferable to be compatible with the component A).

Next, the component C) which constitutes the fluorine-containing organopolysiloxane composition of the present invention acts as a curing agent in the composition of the present invention, which is hydrogen bonded to a silicon atom in one molecule. The organohydrogenpolysiloxane has at least three atoms (≡Si—H groups). For this organohydrogenpolysiloxane

[Chemical 21]

[Chemical formula 22]

[Chemical formula 23]

[Chemical formula 24] Examples include those represented by (CH ₃ ) ₂ HSiO _0.5
It may be a copolymer composed of units and SiO ₂ units.

However, the blending amount of this organohydrogenpolysiloxane is such that the aliphatic unsaturated group present in the component A) of this composition and the ≡Si--H in this component C).
Since it is for addition reaction with a group, it is preferable that the amount of the ≡Si—H group is 1 for each aliphatic unsaturated group in the component A). Is in the range of 0.5 to 5.0 mol per 1 mol of the aliphatic unsaturated group.

The platinum or platinum group compound as the component D) which constitutes the fluorine-containing organopolysiloxane composition of the present invention is a catalyst for the addition reaction between the component A) and the component C). Known materials may be used, including platinum black, chloroplatinic acid, chloroplatinic acid and alcohols, ethers, aldehydes, olefins such as ethylene, complexes with vinylsilane or siloxane, carriers such as alumina, silica, and asbestos. The platinum compound is supported by platinum powder, and the amount of the platinum compound may be in the range of 1 to 500 ppm, preferably 5 to 20 ppm as the amount of platinum based on 100 parts by weight of the component A).

The fluorine-containing organopolysiloxane composition of the present invention can be obtained by uniformly kneading the above-mentioned components A) to D) by using a mixer such as a roll, a kneader or a Banbarixer. If necessary, use fumed silica, precipitated silica, carbon powder, titanium dioxide, aluminum oxide, quartz powder, reinforcing agents such as talc, sericite and bentonite, and fibrous fillers such as asbestos, glass fibers and organic fibers. 5 to 300 parts by weight, preferably 10
You may mix in the range of -200 weight part.

Further, in the fluorine-containing organopolysiloxane composition of the present invention, if necessary, a dispersant such as diphenylsilanediol, a dimethylpolysiloxane having a low degree of polymerization and a molecular chain end hydroxyl group blocked, and hexamethyldisilazane,
A heat resistance improver such as ferrous oxide, ferric oxide, cerium oxide and iron octylate, a pigment and the like may be added and blended.

The thus-produced fluorine-containing organopolysiloxane composition of the present invention is heat-treated at a temperature of 100 to 300 ° C. for 30 seconds to 1 hour under normal pressure or pressure and, if necessary, 150 Secondary vulcanization at ~ 250 ° C for 2-24 hours cures completely into a highly elastic silicone rubber elastic body, which exhibits excellent adhesion and adhesion to various materials. Is particularly useful as a packing, sealing and coating material in the electrical and electronic fields.

[0019]

EXAMPLES Next, examples and comparative examples of the present invention will be shown. Example 1 and Comparative Example 1 A 1 liter separabar flask equipped with a stirrer was used

[Chemical 25] Cyclotrisiloxane represented by 1,000 g (1.458 mol)
And expression

[Chemical formula 26] 11.9 g (0.01458 mol) of lithium silanolate and 1.0 g of tetraglyme were added and reacted at 100 ° C. for 5 hours in a nitrogen gas atmosphere.

This is cooled to 50 ° C.

[Chemical 27] 2.6 g (0.0219 mol) of vinyldimethylchlorosilane represented by

[Chemical 28] 6.1 g of divinyltetramethyldisilazane (0.03
28 mol) was added, and the mixture was stirred for 2 hours for neutralization and terminal silylation, followed by filtration and stripping. As a result, 938 g of a polymer having a viscosity of 3,570 cS was obtained.

Then, 15 parts by weight of fumed silica having a specific surface area of 300 m ² / g was added to 100 parts by weight of this polymer in a kneader.
After kneading at ℃ / 3 hours, add the formula

[Chemical 29] Fluorinated organopolysiloxane of 3.75g, carbon black 0.2g, formula

[Chemical 30] 0.1 g of a toluene solution of a chloroplatinic acid modifying catalyst (platinum concentration 1.0% by weight) and 2-ethylisopropanol.
002 g and 1.0 g of a fluorine-containing alkoxysilane represented by the formula CF ₃ CH ₂ CH ₂ Si (OCH ₃ ) ₃ were added and mixed to prepare a composition I (Example 1), and the fluorine-containing alkoxysilane as an adhesion aid was added. Composition II (Comparative Example 1) was prepared in the same manner except that no alkoxysilane was added.

Next, the compositions I and II were pressed at a temperature of 150 ° C. and a pressure of 100 kg / cm ² for 15 minutes to form a sheet having a thickness of 2 mm, which was heat treated at 150 ° C. for 1 hour. When the rubber physical properties of the heat-treated sheet were examined by the method according to JIS K6301, the results shown in Table 1 were obtained. For this, the shear adhesive strength test sample as shown in FIG. 1 was obtained. Making, glass, aluminum,
The shear adhesive strength (kgf / cm ² ) and cohesive failure rate (%) for iron and epoxy resin were measured, and the results shown in Table 2 were obtained.

Regarding this, its solvent swelling property, dimethyl silicone rubber for comparison, KE951 [trade name of Shin-Etsu Chemical Co., Ltd.] and trifluoropropylmethylsiloxane rubber type fluorosilicone rubber,
The solvent swelling property of FE251 [trade name of Shin-Etsu Chemical Co., Ltd.] was examined. The solvent swelling property was calculated by dividing the volume and weight after soaking in the solvent at 20 ° C for 72 hours by the initial volume and weight. As a result, the results shown in Table 3 were obtained.

[0024]

[Table 1]

[Table 2]

[Table 3]

Example 2 and Comparative Example 2 A 1 liter separable flask equipped with a stirrer was used.

[Chemical 31] 1,000 g (1.529 mol) of cyclotrisiloxane
And expression

[Chemical 32] Add 2.8 g (0.023 mol) of lithium silanolate and 1.0 g of tetraglyme under a nitrogen gas atmosphere 1
After reacting at 00 ℃ for 5 hours and cooling to 50 ℃,

[Chemical 33] 2.8g (0.023 mol) of vinyldimethylchlorosilane represented by

[Chemical 34] 6.4 g of divinyltetramethyldisilazane (0.03
(5 mol) was added, and the mixture was stirred for 2 hours for neutralization and silylation, followed by filtration and stripping.
911 g of a polymer having a viscosity of 10.510 cS was obtained.

Then, 15 parts by weight of fumed silica having a specific surface area of 300 m ² / g was added to 100 parts by weight of this polymer in a kneader.
After kneading at ℃ / 3 hours, add the formula

[Chemical 35] Organohydrogenpolysiloxane represented by 0.5
8g, carbon black 0.2g, chloroplatinic acid alcohol solution (platinum concentration 0.5% by weight) 0.2g, 2-ethylisopropanol 0.002g and fluorine-containing compound represented by the formula C ₈ F ₁₇ CH ₂ CH ₂ Si (OCH ₃ ) _3. 1.0 g of alkoxysilane was added and mixed to prepare a composition (Example 2), and the composition IV (Comparative Example 2) was prepared in the same manner except that the fluorine-containing alkoxysilane as the adhesion aid was not added. It was

Then, using the compositions III and IV, a sheet and a sample for shear adhesive strength test were prepared in the same manner as in Example 1, and the physical properties thereof were examined. The results as shown in Table 5 for the adhesive force and Table 6 for the solvent swelling property were obtained.

[0028]

[Table 4]

[Table 5]

[Table 6]

[0029]

The present invention relates to a fluorine-containing organopolysiloxane composition, which is, as mentioned above, A) 1.
Having at least two alkenyl groups bonded to a silicon atom in the molecule and having the above formulas (1) to (5) in one molecule
An alkenyl group-containing organopolysiloxane having at least one fluorine-containing substituent bonded to a silicon atom selected from B), a fluorine-containing alkoxysilane, C) an organohydrogenpolysiloxane, D) platinum or a platinum group compound. The amount of .tbd.Si--H groups in this C) component is 0.5 to 5.0 mol per 1 mol of the aliphatic unsaturated group in the composition, which is usually The silicone rubber is completely cured under the same conditions as the silicone rubber to produce a highly elastic silicone rubber, but this silicone rubber has excellent adhesiveness and adhesion to various materials without impairing the various properties of silicone rubber. In addition, because of its low moisture permeability, it has an industrial advantage that it is useful as a material for packing, sealing, and coating in electric and electronic fields. To become.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a sample for shear adhesive strength test used in Examples and Comparative Examples of the present invention.

[Explanation of symbols]

1, 1 '... Adhered material, 2 ... Adhesive agent, 3, 3' ... Spacer, 4 ... Heavy slag.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Koichi Yamaguchi, 1st Hitomi, Osamu Matsuida-cho, Usui-gun, Gunma Pref. 10 Shinetsu Chemical Industry Co., Ltd. Silicone Electronic Materials Research Laboratory (72) Takatoshi Matsuda Matsui, Usui-gun, Gunma Prefecture Tamachi Oji Hitomi 1-10 Shin-Etsu Chemical Co., Ltd. Silicone Electronic Materials Research Laboratory (72) Inventor Kenichi Fukuda Matsuida-cho, Gunma Prefecture Usui-gun 1 Hitomi 10 Shin-Etsu Chemical Industrial Silicone Electronic Materials Research Center

Claims (1)

[Claims] 1. A) Having at least two alkenyl groups bonded to a silicon atom in one molecule, and having one of the following formulas (1) to (5) in one molecule: (N is an integer of 1 to 8) (N is an integer of 1 to 8) (N is an integer of 1 to 8) (N = 1 to 8 integer) C _n F _{2n + 1} CH ₂ CH ₂ --- (5) (n = 1 to 10 integer) selected as a silicon atom An alkenyl group-containing organopolysiloxane having at least one bound fluorine-containing substituent, B) General formula R _f CH ₂ CH ₂ Si (OR ¹ ) ₃ (where R _f is a monovalent perfluoropolyether group or 1
Valent perfluoroalkyl group, R ¹ is a fluorine-containing alkoxysilane represented by an unsubstituted or substituted monovalent hydrocarbon group having 1 to 8 carbon atoms, and C) at least a hydrogen atom bonded to a silicon atom in one molecule. An organohydrogenpolysiloxane having 3 units, D) Platinum or a platinum group compound, and the amount of ≡Si—H groups in the C) component is 0.5 with respect to 1 mol of the aliphatic unsaturated group in the composition. A fluorine-containing organopolysiloxane composition, characterized in that the amount is up to 5.0 mol.