JPH06306297A - Curable organopolysiloxane composition - Google Patents

Abstract

PURPOSE:To provide composition which can be used in packing of high solvent and moisture resistance by using organopolysiloxane having a plurality of alkenyls and fluorine-containing substituents bonding to Si atoms, organohydrogen-polysiloxane and a catalyst in the platinum group. CONSTITUTION:(A) Organopolysiloxane having at least 2 alkenyl groups bonding to silicon atoms each molecule and at least one fluorine-containing substituent bonding to silicon atom each molecule represented by formula I (m is integer of 1 to 4; n is integer of 1 to 6), formula II and formula III (j is integer of 1 to 12; k is integer of 1 to 4), (B) organohydrogenpoly-siloxane of formula IV (R<1>, R<2> are monovalent organic group; h is 2 or more integer; i is integer of 0 or greater, Rf is fluorine containing substituent of formula I to III) and (C) a catalyst in the platinum group in the periodic table are used to obtain the objective composition which can be readily cured to form packings, sealants, coating materials for electronic parts having excellent solvent and moisture resistance.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention provides a curable organopolysiloxane composition which gives a cured product having excellent curability, solvent resistance and moisture resistance and which is suitable as a packing for electronic parts, a sealant, a coating agent and the like. Regarding

[0002]

Conventionally, addition-curable silicone compositions have been used in various fields. This silicone composition is crosslinked by a hydrosilylation reaction represented by the following reaction formula and cured.

[0003]

[Chemical 3]

In this case, the siloxane containing ≡SiH group is used as a cross-linking agent, and conventionally, the following compounds are conventionally used.

[0005]

[Chemical 4]

However, when the above-mentioned cross-linking agent is blended with a fluorine-containing silicone composition having a high fluorine content, the curability becomes insufficient due to poor compatibility, and according to the study of the present inventor, it is arbitrarily determined. Even if an adhesion promoter was added, the cured product hardly adhered to various substrates, and the adhesiveness was lacking.

Therefore, in recent years, ≡ having a fluorine-containing group in the side chain as shown by the following general formula (5) as a crosslinking agent.
The compatibility is improved by using a SiH group-containing siloxane compound.

[0008]

[Chemical 5]

However, in the siloxane compound of the above formula (5), the Rf group of the side chain acts sterically against the ≡SiH group, and in this case also, the organo compound giving a cured product having sufficient curability and adhesiveness. It was difficult to obtain a polysiloxane composition. Therefore, it has been desired to improve these problems in the curable organopolysiloxane composition.

The present invention has been made in view of the above circumstances.
To provide a curable organopolysiloxane composition which cures rapidly and has excellent properties such as solvent resistance and moisture resistance, and which gives a cured product having excellent adhesion when an adhesion promoter is optionally added. With the goal.

[0011]

Means for Solving the Problems The present inventor has conducted extensive studies to achieve the above object, and as a result, has at least two alkenyl groups bonded to a silicon atom in one molecule and has one molecule. An organopolysiloxane having at least one fluorine-containing substituent selected from the groups represented by the following formulas (1), (2) and (3) bonded to a silicon atom, and represented by the following general formula (4): By blending an organohydrogenpolysiloxane and a platinum group metal-based catalyst, it cures quickly and has little volume swelling even when immersed in various solvents, excellent solvent resistance, low moisture permeability and moisture resistance. In addition, the curable organopolysiloxane composition has a small surface energy and, when an adhesion promoter is optionally added, gives a cured product having excellent adhesion to various substrates. Is then found that, the present invention has been accomplished.

[0012]

[Chemical 6] (However, in the formula, m is an integer of 1 to 4, n is an integer of 1 to 6, j
Is an integer of 1 to 12, and k is an integer of 1 to 4. )

[0013]

[Chemical 7] (However, in the formula, R ¹ and R ² are each independently a monovalent organic group, h is an integer of 2 or more, i is an integer of 0 or more, and Rf is the above formula (1), (2) or (3). It is a fluorine-containing substituent.)

Therefore, the present invention provides (A) the above formulas (1), (2) and (2) which have at least two alkenyl groups bonded to a silicon atom in one molecule and which are bonded to a silicon atom in one molecule. Organopolysiloxane having at least one fluorine-containing substituent selected from the group represented by (3) (B) Organohydrogenpolysiloxane represented by the above general formula (4) (C) Platinum group metal-based catalyst The present invention provides a curable organopolysiloxane composition.

The present invention will be described in more detail below. The first component of the curable organopolysiloxane composition of the present invention has at least two alkenyl groups bonded to silicon atoms in one molecule, and 1 The organopolysiloxane has at least one fluorine-containing substituent selected from the groups represented by the following formulas (1), (2) and (3) bonded to a silicon atom in the molecule.

[0016]

[Chemical 8] (However, in the formula, m is an integer of 1 to 4, n is an integer of 1 to 6, j
Is an integer of 1 to 12, and k is an integer of 1 to 4. )

The viscosity of the organopolysiloxane is not particularly limited, but is preferably 500 to 50,000 centistokes.

Examples of the alkenyl group contained in the above-mentioned organopolysiloxane include a vinyl group and an allyl group. From the practical point of view, the vinyl group and the allyl group are preferable.

Substituents bonded to a silicon atom other than the above-mentioned fluorine-containing substituent and alkenyl group are, for example, alkyl groups such as methyl group, ethyl group, propyl group and butyl group,
It is preferably a monovalent hydrocarbon group having 1 to 8 carbon atoms such as an aryl group such as a phenyl group.

As such an organopolysiloxane, specifically, those represented by the following general formula (5) are preferably used.

[0021]

[Chemical 9]

In the present invention, among the organopolysiloxanes represented by the above formula (5), those represented by the following general formula in which both terminals are terminated by vinyl groups are highly practical and are more preferably used.

[0023]

[Chemical 10] (In the formula, R ³ , x and y are the same as above.)

The organopolysiloxane of the above formula (5) is, for example, an organopolysiloxane having a fluorine-containing substituent represented by the following general formula (7) and an organopolysiloxane having a terminal vinyl group terminated by the following general formula (8). Further, if necessary, an organocyclotrisiloxane represented by the following general formula (9) is mixed in an appropriate ratio according to the purpose, and a known equilibration reaction is allowed to proceed in the presence of an acid or alkali polymerization catalyst to carry out polymerization. It can be manufactured by

[0025]

[Chemical 11] (However, in the formula, R ³ and Rf are respectively the same as above,
m is an integer of 1 or more. )

In this case, it is preferable to use, for example, a lithium catalyst or a ring-opening polymerization catalyst such as a pentacoordinate silicon catalyst represented by the following formula (10) as the polymerization catalyst. The addition amount of the polymerization catalyst is not particularly limited and can be a catalytic amount.

[0027]

[Chemical 12]

Further, after the completion of the polymerization reaction, the end of the obtained polymer is treated with an organosilicon compound represented by the following general formula (11) to produce a polymer having a very low content of low molecular siloxane.

[0029]

[Chemical 13](However, in the formula R³Is the same as above, X is NH ₂, OC
CH₃Or Cl. )

The second component of the composition of the present invention, organohydrogenpolysiloxane, acts as a cross-linking agent, and hydrogen bonded to a silicon atom in one molecule represented by the following general formula (4). It contains at least two atoms.

[0031]

[Chemical 14] (However, in the formula, R ¹ and R ² are independently monovalent organic groups, h is an integer of 2 or more, i is an integer of 0 or more, and Rf is the same as above.)

Here, R ¹ and R ² in the above formula (4) are, for example, an alkyl group having 1 to 8 carbon atoms such as a methyl group, an ethyl group, a propyl group and a butyl group, and an aryl group such as a phenyl group. And monovalent hydrocarbon groups.

The organohydrogenpolysiloxane of the above formula (4) is, for example, a fluorine-containing disiloxane represented by the following general formula (12) and a hydrogencyclosiloxane represented by the following general formula (13), and if necessary, the following general formula: It can be synthesized by subjecting the cyclosiloxane represented by the formula (14) to an equilibration reaction by an ordinary method using an acid catalyst.

[0034]

[Chemical 15]

In this case, the mixing ratio of the fluorine-containing disiloxane of the formula (12) and the hydrogencyclosiloxane of the formula (13) is not particularly limited.

Incidentally, h in the above formula (4) can be set to an appropriate value according to the purpose by adjusting the usage ratio of the hydrogencyclosiloxane of the formula (13) during the reaction.

As the acid catalyst, for example, sulfuric acid, sulfuric acid anhydride, trifluoromethylsulfonic acid, etc. may be used, and the addition amount thereof may be a catalytic amount.

The mixing ratio of the organopolysiloxane of the first component and the organohydrogenpolysiloxane of the second component is such that one alkenyl group bonded to the silicon atom in the first component is the silicon atom of the second component. The proportion of hydrogen atoms bonded to at least 0.5, especially the first
The ratio of the alkenyl group bonded to the silicon atom in the component to the hydrogen atom bonded to the silicon atom of the second component is 1: 0.5.
The range of ˜1: 10, particularly 1: 1 to 1: 5 is preferable. If the blending amount of the second component is less than the above proportion, curing may be poor, and if the blending amount of the second component exceeds the above proportion, curing failure and physical properties such as rubber strength may be deteriorated.

In the present invention, a platinum group metal-based catalyst is blended as the third component for the addition reaction of the first component and the second component.

Examples of platinum group metal-based catalysts include platinum,
Examples thereof include platinum group metals such as rhodium and iridium, and compounds thereof. Particularly preferred are chloroplatinic acid, chloroplatinic acid and various olefins, vinyl siloxane complex salts, platinum black, and various carriers in which platinum is supported. used.

The addition amount of the platinum group metal-based catalyst of the third component is
A normal amount used for a curable silicone composition that is cured by utilizing this kind of addition reaction, that is, a platinum amount of 1 to 1000 ppm with respect to the total weight of the first component and the second component.
Is preferred.

The composition of the present invention can be obtained by blending the above-mentioned first to third components in predetermined amounts, and an adhesion promoter can be added if necessary, whereby the adhesion is improved. Can be made. In this case, the following compounds are preferably used as the adhesion promoter,
The addition amount is preferably 0.1 to 5 parts with respect to 100 parts of the first component. CF ₃ CH ₂ CH ₂ Si (OCH ₃ ) ₃

Further, the composition of the present invention contains, as an optional component, a reinforcing silica filler such as fumed silica, silica aerogel, an extension filler such as diatomaceous earth, powdered quartz, carbon black and calcium carbonate, and a heat agent. It is also possible to add various additives that are commonly used in silicone rubber, such as stabilizing additives, antioxidants, adhesion promoters and pigments. In addition, the addition amount of these optional components can be a normal amount within a range that does not impair the effects of the present invention.

When the curable organopolysiloxane composition of the present invention thus obtained is heated to 70 to 180 ° C., it is completely cured in a short time due to the addition reaction between the first component and the second component. It gives a cured product having excellent characteristics, and can be cured in about 15 minutes at 100 ° C., particularly 120 ° C. or higher.

[0045]

EFFECTS OF THE INVENTION The curable organopolysiloxane composition of the present invention is rapidly cured to have excellent solvent resistance and moisture resistance, has a small surface energy, and when various adhesion promoters are optionally added, It gives a cured product having excellent adhesiveness to a substrate and can be suitably used as a packing for electronic parts, a sealant, a coating agent and the like.

[0046]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. All parts in each example are parts by weight.

[Example] To 100 parts of a vinyl group-containing organopolysiloxane polymer represented by the following formula (15),
15 parts of fumed silica filler treated with trimethylsiloxane groups were added, mixed manually, heat treated and mixed on a three roll mill.

[0048]

[Chemical 16]

1.83 parts of an organohydrogenpolysiloxane represented by the following formula (16), 0.2 part of carbon black, and chloroplatinic acid as a catalyst were added to CH ₂ ═CH.
Si (CH ₃ ) ₂ OSi (CH ₃ ) ₂ CH = CH ₂ modified vinyl group-containing polysiloxane diluent (platinum concentration 0.5
Wt%) 0.2 part, 2-ethynylisopropanol 0.
Three parts were added and mixed to prepare a curable organopolysiloxane composition.

[0050]

[Chemical 17] (However, in the formula, Rf is the same as above, and h has an average value of 1
It is 2. )

Next, this composition was degassed under reduced pressure, placed in a rectangular frame, and deflated again for 120 kg.
After pressing and curing under conditions of f / cm ² and 150 ° C. for 10 minutes, heat treatment was further performed at 150 ° C. for 50 minutes. A test piece was cut out from this cured sample, and its rubber physical properties were measured according to JIS K6301.
2 kgf / cm ² , tear strength 4.9 kgf / cm,
Numerical values of elongation 371%, hardness 25 and specific gravity 1.46 g / cm ³ were obtained. Furthermore, this cured product had a small volume swelling and a low water permeability.

In addition, the above composition may also be prepared by adding CF ₃ CH ₂ CH ₂ Si.
When 0.5 part of (OCH ₃ ) ₃ was added to aluminum and an epoxy coated plate (containing a nitrogen compound) and the adhesiveness was examined, it was confirmed that the product was completely bonded.

COMPARATIVE EXAMPLE An organopolysiloxane composition was prepared in the same manner as in Example except that 3.25 parts of the compound represented by the following formula (17) was added in place of the organohydrogenpolysiloxane of the above formula (16). Was prepared.

[0054]

[Chemical 18] (However, in the formula, Rf is the same as above, x has an average value of 6, and y has an average value of 2.)

When this composition was cured, the rubber had physical properties such as a tensile strength of 25 kgf / cm ² and a tear strength of 1.
The values of 0.4 kgf / cm, elongation 388% and hardness 20 were obtained, and the curability was not sufficient.

Further, as in the example, CF ₃ CH ₂ CH ₂ Si is used.
The product to which (OCH ₃ ) ₃ was added adhered to the aluminum piece, but the adhesion to the epoxy coated plate was insufficient, and peeling at the interface was observed.

Next, as a reference example, a synthesis example of the organohydrogenpolysiloxane of the above formula (16) is shown.

Reference Example 36.2 g (0.033 mol) of disiloxane represented by the following formula (i), the following formula (ii)
Into a 100 ml three-necked flask equipped with a stirrer, a condenser and a thermometer, 15.9 g (0.066 mol) of the cyclosiloxane represented by was charged and stirred.

After replacing the inside of the system with nitrogen, 0.15 g (0.001 mol) of CF ₃ SO ₃ H was added, and the equilibration reaction was carried out at 80 ° C. After 16 hours, the mixture was cooled to room temperature, 2 g of water was added, and the mixture was stirred for 1 hour, then, the aqueous layer was separated. Further, when washed with saturated sodium sulfate, the following formula (iii)
There were obtained 45.3 g of a mixture of compounds shown by.

[0060]

[Chemical 19] (However, in the formula, r is an integer of 0 or more, and the average value is 8
Is. )

Next, the mixture of the compound of the above formula (iii) is stripped at 150 ° C. and 1 × 10 ⁻⁴ Torr to distill away the siloxane compound of r═O and 1 to obtain a siloxane having r of 2 or more. 20.3 g of compound was obtained. It was confirmed from the analysis results shown below that the obtained compound had a structure represented by the following formula (iv).

[0062]

[Chemical 20] (However, s is an integer of 2 or more, and the average value of s is 12.) Elemental analysis: C H Si F 2 calculated value (%) 23.86 3.78 21.70 35.65 Measured value (%) ) 23.52 3.84 22.11 35.47 * Calculated as C ₃₆ H ₆₈ O ₁₇ F ₃₄ Si ₁₄ Infrared absorption spectrum: A characteristic absorption derived from a SiH group was observed at a wave number of 2170 cm ⁻¹ . Si-H amount: Calculated value: 6.63 × 10 ^-3 mol / g Actual value: 6.77 × 10 ^-3 mol / g ¹ H-NMR spectrum: (TMS standard) δ = 4.67 ppm (-SiH, m, 12H) δ = 0.20 ppm (-Si-CH ₃ , m, 48
H) δ = 0.53 to 1.00 ppm (Si—CH ₂ —
C, m, 4H) δ = 1.80~2.77ppm (CF-CH 2 -
C, m, 4H) ¹⁹ F-NMR spectrum: (CF ₃ COOH standard) φ = −3.79 ppm (—CF (C F ₃ ) CF
₂₋ , 6F) φ = −5.19 ppm (CF ₃ CF ₂ CF ₂ −, 1
0F) φ = -7.09ppm (-CF ( CF 3) C F
₂ −, 4 F) φ = −11.05 ppm (−C F ₂ CF ₂ CH
₂ −, 4 F) φ = −43.43 ppm (−CF ₂ C F ₂ CH
₂ −, 4 F) φ = −53.10 ppm (−CF ₃ C F ₂ CF
₂ −, 4 F) φ = −68.70 ppm (−C F (CF ₃ ) CF ₂
-, 2F)

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shinichi Sato No. 1 Hitomi, Osamu Matsuida-cho, Usui-gun, Gunma Prefecture Shin-Etsu Chemical Co., Ltd. Silicone Electronic Materials Research Laboratory (72) Hirofumi Kinoshita Matsuida-cho, Usui-gun, Gunma Prefecture Daiji Hitomi No. 10 Shin-Etsu Chemical Co., Ltd. Silicone Electronic Materials Research Laboratory (72) Inventor Masatoshi Arai Matsuda-cho, Usui-gun, Gunma Daiji Hitomi No. 10 Shin-Etsu Chemical Industrial Co., Ltd. Silicone Electronic Materials Research Laboratory (72) Inventor Hironao Fujiki No. 1 Hitomi, Osamu Matsuida-cho, Usui-gun, Gunma 10 Shin-Etsu Chemical Co., Ltd. Silicone Electronic Materials Technology Laboratory

Claims (1)

[Claims] 1. A compound represented by the following formulas (1), (2) and (3) having (A) at least two alkenyl groups bonded to a silicon atom in one molecule and bonded to a silicon atom in one molecule: At least one fluorine-containing substituent selected from the groups represented
An organopolysiloxane having 1 (However, in the formula, m is an integer of 1 to 4, n is an integer of 1 to 6, j
Is an integer of 1 to 12, and k is an integer of 1 to 4. ) (B) An organohydrogenpolysiloxane represented by the following general formula (4): (However, in the formula, R ¹ and R ² are each independently a monovalent organic group, h is an integer of 2 or more, i is an integer of 0 or more, and Rf is the above formula (1), (2) or (3). It is a fluorine-containing substituent.) (C) A curable organopolysiloxane composition comprising a platinum group metal-based catalyst.