JP2638728B2 - Fluorinated organopolysiloxane composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a fluorine-containing organopolysiloxane composition, in particular, a silicone rubber elastomer having excellent adhesion and adhesion to various materials and having high elasticity when cured. The present invention relates to a fluorine-containing organopolysiloxane composition.

[0002]

2. Description of the Related Art Various types of fluorine-containing silicone rubbers are known, and they have excellent properties such as electrical insulation, heat resistance, cold resistance and weather resistance, as well as solvent resistance. Nature, water repellency, oil repellency,
It is said to have a feature that surface properties such as releasability are also excellent.

[0003] However, this known fluorine-containing silicone rubber has a drawback that its adhesiveness to various equipments is inferior because of its excellent surface characteristics as described above, and a countermeasure 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) having at least two alkenyl groups bonded to a silicon atom in one molecule. And the following formulas (1) to (5) in one molecule

Embedded image (N = 1-8 integer)

Embedded image (N = 1-8 integer)

Embedded image (N = 1-8 integer)

Embedded image (N is an integer of 1 to 8) C _n F _{2n + 1} CH ₂ CH ₂ -... (5) For a silicon atom selected from (n = 1 to 10) An alkenyl group-containing organopolysiloxane having at least one bonded fluorine-containing substituent, B) a general formula R _f CH ₂ CH ₂ Si
(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 (原子 Si—H groups) bonded to a silicon atom in one molecule; D) platinum or a platinum group compound; ≡ The amount of the Si-H group is 0.5 to 5.0 mol per 1 mol of the aliphatic unsaturated group in the composition.

[0005]

That is, the present inventors have developed a fluorine-containing organopolysiloxane composition which exhibits excellent adhesion and adhesion to various materials without impairing the properties of the fluorine-containing silicone rubber. As a result of various investigations, an alkenyl-containing organopolysiloxane containing a fluorinated substituent selected from the above formulas (1) to (5), a fluorinated alkoxysilane represented by the above general formula, and an organohydrogenpolysiloxane When platinum or a platinum group compound as an addition reaction catalyst is added to an addition reaction type organopolysiloxane composition comprising siloxane, this is cured by an addition reaction to form a silicone rubber. It has been found that it has excellent permeability, and since it has low moisture permeability, it can be used in 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-mentioned formula (1)
(5) an organopolysiloxane containing a fluorine-containing substituent and at least two alkenyl groups, B) a compound represented by the general formula R _f CH ₂ CH ₂ Si (OR) ₃ (R _f and R are the same as described above) Fluorinated alkoxysilane, C) organohydrogenpolysiloxane, D) platinum or a platinum group compound, which can be made of various materials without deteriorating the properties of conventionally known fluorinated silicone rubbers. It exhibits excellent adhesiveness and adhesion to the silicone rubber, and when cured, gives a silicone rubber elastic body having excellent elasticity.

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

Embedded image (Where R ² and R ³ are unsubstituted or substituted 1 to 8 carbon atoms)
A valent hydrocarbon group and R ⁴ represent a fluorine-containing substituent represented by the above formulas (1) to (5). ) And a general formula (b)

Embedded image (Where R ² is the same as above, R ⁵ is an unsaturated monovalent hydrocarbon group)
And a general formula (c)

Embedded image The cyclotrisiloxane represented by

Embedded image Can be obtained by co-existing with divinyldisiloxane represented by and copolymerizing with an acid or an alkali.

Embedded image (R ² is the same as above, M is an alkali metal) and can be obtained by polymerization with a silanolate catalyst such as an organopolysiloxane.

In the above general formula, R ¹ , R ² ,
As R ³ , an alkyl group such as a methyl group, an ethyl group, an isopropyl group, and a butyl group, a cycloalkyl group such as a cyclohexyl group and a cyclopentyl group, an aryl group such as a phenyl group, a tolyl group, and a xylyl group, a benzyl group, and a phenylethyl group Aralkyl groups, such as chloromethyl, chloropropyl, chlorohexyl, and 3,3,3-trifluoropropyl in which some or all of the hydrogen atoms bonded to these carbon atoms have been substituted with halogen atoms, cyano groups, etc. Group, carbon number 1 selected from 2-cyanoethyl group and the like.
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 and an ethynyl group.

The acid or alkali as a polymerization catalyst for obtaining the above base polymer includes 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 siliconates, tetrabutylphosphine hydroxides, and tetraammonium hydroxides;

Embedded image And sulfonic acids such as sulfuric acid and trichloromethanesulfonic acid.

The fluorinated alkoxysilane as the component B) constituting the fluorinated organopolysiloxane composition of the present invention functions as an adhesion aid in the composition of the present invention. _f CH ₂ CH ₂ Si (OR ¹ )
₃ (R _f and R ¹ are the same as described above). In the formula, R _f is a monovalent perfluoropolyether or a monovalent perfluoroalkyl group.

Embedded image

Embedded image

Embedded image

Embedded image Such as perfluoropolyether groups, or CF ₃ , C ₆
Perfluoroalkyl such as F ₁₃ -and C ₈ F ₁₇ are exemplified.

The component B) is represented by the general formula (d):
_{From the} trichlorosilane represented by fCH ₂ CH ₂ SiCl ₃ as a starting material, it can be synthesized by a known method from now on.

Embedded image

Embedded image 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 are exemplified.

If the amount of the component (B) is too small, the adhesiveness of the composition becomes insufficient if the amount is too small, and if the amount is too large, the heat resistance and compression set characteristics are deteriorated. A) 0.01 to 100 parts by weight of component
The amount may be in the range of 30 parts by weight, preferably in the range of 0.05 to 15 parts by weight. In order to obtain a uniform cured product of the component (B) and to maintain the fluidity of the composition, It is preferable that it be compatible with the component (A).

Next, the component (C) constituting the fluorine-containing organopolysiloxane composition of the present invention operates as a curing agent in the composition of the present invention, and is composed of hydrogen bonded to a silicon atom in one molecule. It is an organohydrogenpolysiloxane having at least three atoms (≡Si—H groups). As this organohydrogenpolysiloxane,

Embedded image

Embedded image

Embedded image

Embedded image Is exemplified, which is (CH ₃ ) ₂ HSiO _0.5
It may be a copolymer composed of units and SiO ₂ units.

However, the amount of the organohydrogenpolysiloxane is determined by the amount of the unsaturated unsaturated group present in the component A) of the composition and the amount of ≡Si—H in the component C).
Since it is intended to cause an addition reaction with a group, it is preferable that the amount of the ΔSi-H group is one for each aliphatic unsaturated group in the component A). May be 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) constituting the fluorine-containing organopolysiloxane composition of the present invention is a catalyst for causing an addition reaction between the component A) and the component C). Any known materials may be used, such as platinum black, chloroplatinic acid, chloroplatinic acid and alcohols, ethers, aldehydes, olefins such as ethylene, complexes with vinylsilane or siloxane, and carriers such as alumina, silica and asbestos. The amount of platinum may be in the range of 1 to 500 ppm, preferably 5 to 20 ppm, based on 100 parts by weight of component A).

The fluorinated organopolysiloxane composition of the present invention can be obtained by uniformly kneading the above components A) to D) using a mixer such as a roll, kneader or Banvarixer. 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 fiber and organic fiber. A) In the range of 5 to 300 parts by weight, preferably 10 parts by weight, relative to the component.
You may mix in the range of -200 weight part.

The fluorine-containing organopolysiloxane composition of the present invention may further comprise a dispersant such as diphenylsilanediol, dimethylpolysiloxane having a low degree of polymerization and capped at the molecular chain terminal hydroxyl group, and hexamethyldisilazane, if necessary.
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 fluorinated organopolysiloxane composition of the present invention thus prepared is subjected to a heat treatment at a temperature of 100 to 300 ° C. for 30 seconds to 1 hour under normal pressure or under pressure. When subjected to secondary vulcanization at ~ 250 ° C for 2 to 24 hours, it is completely cured and becomes a highly elastic silicone rubber elastic material, 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]

Next, examples of the present invention and comparative examples will be described. Example 1, Comparative Example 1 The formula was placed in a 1 liter separabal flask equipped with a stirring device.

Embedded image 1,000 g (1.458 mol) of cyclotrisiloxane represented by
And expression

Embedded image 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.

The temperature is lowered to 50 ° C.

Embedded image 2.6 g (0.0219 mol) of vinyldimethylchlorosilane represented by

Embedded image 6.1 g of divinyltetramethyldisilazane (0.03
28 mol), 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.

Next, 15 parts by weight of a 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, the formula

Embedded image 3.75 g of fluorine-containing organopolysiloxane represented by the formula, carbon black 0.2 g, formula

Embedded image 0.1 g of a toluene solution (platinum concentration: 1.0% by weight) of a chloroplatinic acid-modified catalyst represented by the formula: 0.1 g of 2-ethylisopropanol
002 g and 1.0 g of a fluorinated alkoxysilane represented by the formula CF ₃ CH ₂ CH ₂ Si (OCH ₃ ) ₃ are added and mixed to prepare a composition I (Example 1), and a fluorine-containing compound as an adhesion aid is prepared. A 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 heated at 150 ° C. for 1 hour. When the rubber properties of the heat-treated sheet were examined by a method according to JIS K6301, the results as shown in Table 1 were obtained. In this regard, a sample for a shear adhesion test as shown in FIG. 1 was obtained. Making, glass, aluminum,
When the shear adhesive strength (kgf / cm ² ) to iron and epoxy resin and the cohesive failure rate (%) were measured, the results shown in Table 2 were obtained.

The swellability of the solvent and the dimethyl silicone rubber KE951 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) for comparison and the fluorosilicone rubber of the trifluoropropylmethylsiloxane rubber type are used for comparison.
The solvent swellability of FE251 [trade name of Shin-Etsu Chemical Co., Ltd.] was examined. The solvent swellability was calculated by dividing the volume and weight after immersion in a 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, Comparative Example 2 A 1-liter separable flask equipped with a stirrer

Embedded image 1,000 g (1.529 mol) of cyclotrisiloxane represented by
And expression

Embedded image 2.8 g (0.023 mol) of lithium silanolate and 1.0 g of tetraglyme represented by
After reacting at 00 ° C for 5 hours, cool down to 50 ° C

Embedded image 2.8 g (0.023 mol) of vinyldimethylchlorosilane represented by

Embedded image 6.4 g of divinyltetramethyldisilazane (0.03
5 mol), stirred for 2 hours to neutralize and silylate, then filtered and stripped.
911 g of a polymer having a viscosity of 10.510 cS were obtained.

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

Embedded image The organohydrogenpolysiloxane represented by 0.5
8 g, carbon black 0.2 g, alcohol solution of chloroplatinic acid (platinum concentration 0.5% by weight) 0.2 g, 2-ethylisopropanol 0.002 g and fluorine-containing compound represented by the formula C ₈ F ₁₇ CH ₂ CH ₂ Si (OCH ₃ ) ₃ A composition IV (Comparative Example 2) was prepared by adding and mixing 1.0 g of alkoxysilane to prepare a composition (Example 2) and treating in the same manner except that no fluorine-containing alkoxysilane as an adhesion promoter was added. Was.

Next, using these compositions III and IV, a sheet and a sample for a shear adhesion test were prepared in the same manner as in Example 1, and the physical properties were examined. The results as shown in Table 5 were obtained for the adhesive force, and the results were shown in Table 6 for the solvent swellability.

[0028]

[Table 4]

[Table 5]

[Table 6]

[0029]

The present invention relates to a fluorine-containing organopolysiloxane composition, which comprises A) 1
Having at least two alkenyl groups bonded to silicon atoms in the molecule, and having one of the above formulas (1) to (5) in one molecule;
Alkenyl group-containing organopolysiloxane having at least one fluorine-containing substituent bonded to a silicon atom selected from the group consisting of: B) fluorine-containing alkoxysilane, C) organohydrogenpolysiloxane, D) platinum or a platinum group compound. The amount of the ≡Si-H group in the component C) is 0.5 to 5.0 mol per 1 mol of the aliphatic unsaturated group in the composition. The silicone rubber is completely cured under the same conditions as the above silicone rubber, resulting in a highly elastic silicone rubber elastic body.This silicone rubber has excellent adhesion and adhesion to various materials without impairing the properties of the silicone rubber. It has the industrial advantage of being useful as a material for packing, sealing and coating in the fields of electricity and electronics because of its low moisture permeability. To become.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a sample for a shear adhesion test used in Examples and Comparative Examples of the present invention.

[Explanation of symbols]

1, 1 ': adherend, 2: adhesive, 3, 3': spacer, 4: heavy metal.

Continuing from the front page (72) Inventor Koichi Yamaguchi 1-10 Hitomi, Matsuida-cho, Usui-gun, Gunma Prefecture Inside Silicone Electronics Materials Research Laboratory, Shin-Etsu Chemical Co., Ltd. Hitomi 1-10 Shin-Etsu Chemical Co., Ltd. Silicone Electronic Materials Technology Research Laboratory (72) Inventor Kenichi Fukuda Gunma Prefecture Usui-gun Matsuida-cho Ojimi 1-10 Shin-Etsu Chemical Co., Ltd. Silicone Electronic Materials Technology Research Laboratory (56 ) References JP-A-4-80264 (JP, A)

Claims (1)

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