JP2001213965A - Production-method for organopolysiloxane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method for an organopolysiloxane whereby the viscosity increase or gelation with time of an organopolysiloxane prepared by subjecting a linear or cyclic organo(poly)siloxane to viscosity increase or polymerization by using an acid-active solid catalyst is inhibited. SOLUTION: In this production method, at least one zeolite-based solid adsorbent is added to an organopolysiloxane prepared by subjecting a linear or cyclic organo(poly)siloxane to viscosity increase or polymerization by using an acid- active solid catalyst and then the adsorbent is separated by filtration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an organopolysiloxane, and more particularly, to a method for thickening or polymerizing a linear or cyclic organo (poly) siloxane using an acid-active solid catalyst. The present invention relates to a method for producing an organopolysiloxane, which can suppress thickening and gelation over time.

[0002]

2. Description of the Related Art A method for producing an organopolysiloxane by thickening or polymerizing a linear or cyclic organo (poly) siloxane using an acid-active solid catalyst is well known (JP-B-56-26248, and Tokiko 63-14
No. 015). The thickening of the resulting organopolysiloxane can be stopped by filtering off the acid-active solid catalyst.

[0003] However, the present inventors have noticed that there is a problem that the obtained organopolysiloxane thickens or gels over time. In particular, they have found that organopolysiloxanes obtained by thickening organo (poly) siloxanes having silicon-bonded hydrogen atoms by using an acid-active solid catalyst have a problem that the viscosity and gelation are remarkable with time.

[0004]

DISCLOSURE OF THE INVENTION The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have reached the present invention. That is, an object of the present invention is to increase the viscosity of organopolysiloxane obtained by thickening or polymerizing linear or cyclic organo (poly) siloxane using an acid-active solid catalyst over time, and to suppress gelation. And a method for producing an organopolysiloxane.

[0005]

According to the present invention, there is provided a method for producing an organopolysiloxane comprising the steps of: adding at least an organopolysiloxane obtained by thickening or polymerizing a linear or cyclic organo (poly) siloxane using an acid-active solid catalyst; After adding one kind of zeolite-based solid adsorbent, the adsorbent is separated by filtration.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The method for producing the organopolysiloxane of the present invention will be described in detail. In the method for producing an organopolysiloxane of the present invention, a linear or cyclic organopolysiloxane is used.
The (poly) siloxane is thickened or polymerized using an acid-active solid catalyst. Examples of the linear or cyclic organo (poly) siloxane include dimethylsiloxane oligomers having silanol groups at both ends of molecular chains, dimethylsiloxane oligomers having trimethylsiloxy groups at both ends of molecular chains, or methyl of these dimethylsiloxane oligomers. A part of the group is a hydrogen atom; an alkyl group such as an ethyl group, a propyl group, a tert-butyl group, a 2-ethylhexyl group, a dodecyl group and an octadecyl group; an alkenyl group such as a vinyl group, an allyl group and a hexenyl group; Aryl groups such as naphthyl group; chloromethyl group,
3,3,3-trifluoropropyl group, 3,3,4,4,5,
Linear organosiloxane oligomer substituted with a halogenated alkyl group such as 5,5-heptafluoropentyl group or difluoromonochloropropyl group; dimethylpolysiloxane having silanol groups at both ends of molecular chain; dimethyl having trimethylsiloxy group at both ends of molecular chain Dimethylpolysiloxanes such as polysiloxanes, or linear organopolysiloxanes in which some of the methyl groups of these dimethylpolysiloxanes are substituted with the same atoms or groups as described above; octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, etc. Or a cyclic organosiloxane oligomer obtained by substituting a part of the methyl group of these dimethylcyclosiloxane oligomers with the same atom or group as described above. In particular, the production method of the present invention is preferable because, after the organo (poly) siloxane having a silicon-bonded hydrogen atom is thickened or polymerized, the time-dependent increase in viscosity and gelation can be remarkably suppressed.

[0007] Examples of the acid-active solid catalyst include K-500 manufactured by Japan Active Shiratosha, Tonsil AC manufactured by Tonsil,
Acid activated clay known by Filtrol Ultra manufactured by Filtrol Co .; and other examples thereof include acid activated aluminum silicate and acid activated activated carbon.

In the production method of the present invention, the above-mentioned linear or cyclic organo (poly) siloxane and the above-mentioned acid-active solid catalyst are stirred, usually at a temperature of 60 ° C to 100 ° C for 4 to 24 hours.
By heating for a time, the organo (poly) siloxane can be thickened or polymerized.

In the production method of the present invention, after the acid-active solid catalyst is filtered off, a zeolite-based solid adsorbent is added to the obtained organopolysiloxane, or the acid-active solid catalyst and the organopolysiloxane are mixed with each other. Characterized in that the above-mentioned zeolite-based solid adsorbent is added to the mixture.
This zeolite-based solid adsorbent is used to suppress the thickening and gelation of the organopolysiloxane over time, and those having a shape such as pellets, beads, meshes, and powders can be used. Examples of the zeolite-based solid adsorbent include natural zeolites and synthetic zeolites. Such a zeolite-based solid adsorbent preferably has an average pore size of 1 to 200 °, particularly,
Preferably it is 1-100 °. In addition, the porosity of the zeolite-based solid adsorbent is preferably 30 to 70%, and particularly preferably 40 to 70%.

In the production method of the present invention, the amount of the zeolite-based solid adsorbent is preferably 0.5 to 30 parts by weight, more preferably 1.0 to 30 parts by weight, based on 100 parts by weight of the organopolysiloxane. Preferably it is 20 parts by weight. This is because if the amount of the zeolite-based solid adsorbent is less than the lower limit of the above range, the resulting organopolysiloxane may not be able to sufficiently suppress the viscosity with time and gelation over time. On the other hand, even if it exceeds the upper limit of the above range, a remarkable effect cannot be obtained.

In the production method of the present invention, the above-mentioned zeolite-based solid adsorbent must be separated from the resulting organopolysiloxane by filtration. Further, if necessary, low volatile components may be distilled off from the obtained organopolysiloxane. The organopolysiloxane thus obtained is characterized in that it does not significantly increase in viscosity or gel during storage. Further, the thus obtained organopolysiloxane having a silicon-bonded hydrogen atom is a crosslinking agent for a hydrosilylation reaction-curable organopolysiloxane composition, in particular, a hydrosilylation reaction-curable type for forming a peelable cured film. Useful as a cross-linking agent for organopolysiloxane compositions.

[0012]

EXAMPLES The method for producing the organopolysiloxane of the present invention will be described with reference to examples. The viscosity of the organopolysiloxane is a value measured at 25 ° C. using a rotary viscometer Bismetron VA using a rotor No. 1 at 12 rpm.

Example 1 A 200 L reaction vessel was charged with a viscosity of 2
140 kg of a methyl hydrogen polysiloxane capped with a trimethylsiloxy group at both ends of a molecular chain of 0 mPa · s and 4 kg of an acid-active solid catalyst (K-500 manufactured by Nippon Kagaku Shirato Co., Ltd.) were charged and mixed uniformly while bubbling with nitrogen. ~ 9
Stirred at 0 ° C. for 19.5 hours. Next, this was cooled, 9.8 kg of a zeolite-based solid adsorbent in the form of pellets having an average pore diameter of 4 mm, a porosity of 52%, and an average particle diameter of 1.6 mm was charged, stirred for 2 hours, and filtered with a filter press. . The viscosity of the obtained organopolysiloxane immediately after filtration and the viscosity after standing at room temperature for 5 months were measured. The results are shown in Table 1.

Example 2 A 200 L reaction vessel was charged with a viscosity of 2
140 kg of a methyl hydrogen polysiloxane capped with a trimethylsiloxy group at both ends of a molecular chain of 0 mPa · s and 4 kg of an acid-active solid catalyst (K-500 manufactured by Nippon Kagaku Shirato Co., Ltd.) were charged and mixed uniformly while bubbling with nitrogen. ~ 9
Stirred at 0 ° C. for 19.5 hours. Next, the mixture was cooled, charged with 9.8 kg of a pellet-shaped zeolite-based solid adsorbent having an average pore diameter of 4 mm, a porosity of 51%, and an average particle diameter of 3 mm, stirred for 2 hours, and filtered with a filter press. The viscosity of the obtained organopolysiloxane immediately after filtration, and 5
The viscosity after standing for months was measured, and the results are shown in Table 1.

Example 3 A 200 L reactor was charged with a viscosity of 2
112 kg of a methyl hydrogen polysiloxane capped with a trimethylsiloxy group at both ends of a molecular chain of 0 mPa · s and 3 kg of an acid-active solid catalyst (K-500 manufactured by Nippon Kagaku Shirato Co., Ltd.) were charged and uniformly mixed while bubbling with nitrogen. ~ 8
Stirred at 0 ° C. for 7 hours. Next, this was cooled, charged with 3 kg of a powdery zeolite-based solid adsorbent having an average pore diameter of 10 °, a porosity of 45%, and an average particle diameter of 10 μm, stirred for 2 hours, and then filtered with a filter press. The viscosity of the obtained organopolysiloxane immediately after filtration and the viscosity after standing at room temperature for 5 months were measured. The results are shown in Table 1.

[Comparative Example 1] A 200 L reactor was supplied with a viscosity of 2
140 kg of a methyl hydrogen polysiloxane capped with a trimethylsiloxy group at both ends of a molecular chain of 0 mPa · s and 4 kg of an acid-active solid catalyst (K-500 manufactured by Nippon Kagaku Shirato Co., Ltd.) were charged and mixed uniformly while bubbling with nitrogen. ~ 9
Stirred at 0 ° C. for 19.5 hours. Next, it was cooled and filtered with a filter press. The viscosity of the obtained organopolysiloxane immediately after filtration and the viscosity after standing at room temperature for 5 months were measured. The results are shown in Table 1.

[Comparative Example 2] A 200 L reactor was charged with a viscosity of 2
110 kg of 0 mPa · s molecular-chain-both-terminal trimethylsiloxy-group-blocked methylhydrogenpolysiloxane and 3 kg of an acid-active solid catalyst (K-500 manufactured by Japan Active Shirato Co., Ltd.) were charged and mixed uniformly while bubbling with nitrogen. ~ 9
Stirred at 0 ° C. for 7 hours. Next, the mixture was cooled, 8 kg of finely divided calcium carbonate was charged, stirred for 2 hours, and filtered with a filter press. The viscosity of the obtained organopolysiloxane immediately after filtration and the viscosity after standing at room temperature for 5 months were measured. The results are shown in Table 1.

Comparative Example 3 A 200 L reactor was charged with a viscosity of 2
140 kg of a methyl hydrogen polysiloxane capped with a trimethylsiloxy group at both ends of a molecular chain of 0 mPa · s and 4 kg of an acid-active solid catalyst (K-500 manufactured by Nippon Kagaku Shirato Co., Ltd.) were charged and mixed uniformly while bubbling with nitrogen. ~ 9
Stirred at 0 ° C. for 19.5 hours. Next, the mixture was cooled, 5 kg of diatomaceous earth (Radiolite 900 manufactured by Showa Denko KK) was charged, and the mixture was stirred for 2 hours and filtered with a filter press. The viscosity of the obtained organopolysiloxane immediately after filtration and the viscosity after standing at room temperature for 5 months were measured. The results are shown in Table 1.

[0019]

[Table 1]

[0020]

The process for producing an organopolysiloxane according to the present invention comprises the steps of: increasing the viscosity of an organopolysiloxane obtained by thickening or polymerizing a linear or cyclic organo (poly) siloxane using an acid-active solid catalyst; There is a feature that gelation can be suppressed.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Naoji Kawamura 2-2 Chigusa Beach, Ichihara City, Chiba Prefecture Toray Dow Corning Silicone Co., Ltd. Chiba Plant F term (reference) 4J035 BA02 EB03 EB04

Claims (5)

[Claims] 1. An organopolysiloxane obtained by thickening or polymerizing a linear or cyclic organo (poly) siloxane using an acid-active solid catalyst, adding at least one zeolite-based solid adsorbent, and then adsorbing the zeolite-based solid adsorbent. A method for producing an organopolysiloxane, comprising filtering off the agent. 2. The method for producing an organopolysiloxane according to claim 1, wherein the linear or cyclic organo (poly) siloxane is an organo (poly) siloxane having a silicon-bonded hydrogen atom. 3. The zeolite-based solid adsorbent having an average pore size of 1
The method for producing an organopolysiloxane according to claim 1, wherein the temperature is 200 to 200 °. 4. The porosity of the zeolite-based solid adsorbent is 30.
The method for producing an organopolysiloxane according to claim 1, wherein the content is from 70% to 70%. 5. The addition amount of the zeolite-based solid adsorbent is 0.5 to 3 parts by weight based on 100 parts by weight of the organopolysiloxane.
The method for producing an organopolysiloxane according to claim 1, wherein the amount is 0 parts by weight.