JP2005239886A - Manufacturing method of silicone ladder polymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a method for manufacturing a silicone ladder polymer which synthesizes in a short time the silicone ladder polymer having a high molecular weight and capable of forming a thick film. <P>SOLUTION: The manufacturing method of the silicone ladder polymer, which synthesizes it by condensation polymerization of a prepolymer obtained by hydrolysis of trichlorosilane, comprises the steps of: adjusting the prepolymer concentration in an organic solvent solution before the condensation polymerization to 0.1-0.2 g/ml; heating the organic solvent solution of the prepolymer, refluxing water generated by the condensation polymerization of the prepolymer and the organic solvent for 30-70 min, and at the same time removing the water in the reflux liquid; after removal of the water, removing the organic solvent so that 20-40% of the amount of the organic solvent in the organic solvent solution of the prepolymer before starting the condensation polymerization may be removed; and after removal of the organic solvent, carrying forward the condensation polymerization at the boiling point of the organic solvent. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing a silicone ladder polymer, and more particularly to a method for producing a high molecular weight silicone ladder polymer.

In the conventional method for producing a silicone ladder polymer, first, a raw material trichlorosilane is dissolved in a ketone solvent, and then water is dropped and stirred in this solution to hydrolyze the raw material trichlorosilane to prepare a prepolymer. . At this time, the solution is cooled.
Next, the solution containing the prepolymer is washed with ultrapure water, and then a nucleophilic reagent is added to the washed solution containing the prepolymer and stirred while heating. While removing the water produced by the dehydration condensation of the prepolymer and heating under reflux of the solvent, the polycondensation reaction is advanced to produce a high molecular weight silicone ladder polymer. (For example, refer to Patent Document 1).

JP-A-1-92224 (page 3-4)

Silicone ladder polymers have been used as protective films for semiconductor elements and sensor elements because of their excellent heat resistance and high purity. In using a silicone ladder polymer for a protective film or the like, it is required that a thick film can be formed on the silicone ladder polymer.
In order to form a thick silicone ladder polymer film without generating cracks, it is necessary to produce a high molecular weight silicone ladder polymer. However, in order to obtain a high molecular weight silicone ladder polymer by the conventional method for producing a silicone ladder polymer, it takes a long time to increase the molecular weight by the condensation polymerization reaction of the prepolymer, and the productivity of producing the high molecular weight silicone ladder polymer. There was a problem with low.

  The present invention has been made to solve the above-described problems, and an object thereof is to obtain a method for producing a silicone ladder polymer capable of synthesizing a high molecular weight silicone ladder polymer capable of forming a thick film in a short time. is there.

  The method for producing a silicone ladder polymer of the present invention is a method for producing a silicone ladder polymer in which a prepolymer obtained by hydrolyzing trichlorosilane is synthesized by condensation polymerization, and the organic solvent solution of the prepolymer before the condensation polymerization The step of adjusting the concentration of the prepolymer in 0.1 to 0.2 g / ml, and heating the organic solvent solution of the prepolymer to produce water generated by condensation polymerization of the prepolymer and the organic solvent. While refluxing for 30 to 70 minutes, in the organic solvent solution of the prepolymer before the condensation polymerization is started, the organic solvent is washed away after the water removal step and the water removal step. 20% to 40% of the amount of the organic solvent, and a step of further proceeding the condensation polymerization at the boiling temperature of the organic solvent after the organic solvent flowing step. It is intended.

  The method for producing a silicone ladder polymer of the present invention is a method for producing a silicone ladder polymer in which a prepolymer obtained by hydrolyzing trichlorosilane is synthesized by condensation polymerization, and the organic solvent solution of the prepolymer before the condensation polymerization The step of adjusting the concentration of the prepolymer in 0.1 to 0.2 g / ml, and heating the organic solvent solution of the prepolymer to produce water generated by condensation polymerization of the prepolymer and the organic solvent. While refluxing for 30 to 70 minutes, in the organic solvent solution of the prepolymer before the condensation polymerization is started, the organic solvent is washed away after the water removal step and the water removal step. 20% to 40% of the amount of the organic solvent, and a step of further proceeding the condensation polymerization at the boiling temperature of the organic solvent after the organic solvent flowing step. Are those, it can be shortened synthesis time of the silicone ladder polymer of high molecular weight.

Embodiment 1.
In the method for producing a high molecular weight silicone ladder polymer in the present invention, first, trichlorosilane such as phenyltrichlorosilane is dissolved in an organic solvent. Next, pure water is dropped into a solution in which phenyltrichlorosilane is dissolved to hydrolyze phenyltrichlorosilane. At this time, it is desirable to cool the solution while stirring. After adding pure water dropwise, in order to complete the hydrolysis reaction, for example, stirring is continued for 2 hours.
After completion of the hydrolysis reaction, the reaction solution is separated into two phases, an organic solution phase and an aqueous phase. to recover.
The recovered organic solution phase is washed with pure water. Examples of the washing method include a method in which the organic solution phase is mixed with the same volume of pure water, stirred or shaken, and then allowed to stand to remove the separated aqueous phase. This washing operation is repeated 3 times or more.

Next, a high molecular weight silicone ladder polymer is synthesized by the following steps using the prepolymer.
In the first step, the organic solution phase containing the washed prepolymer is collected in a reaction vessel equipped with a stirrer, a reflux condenser and a trap, and the organic solution phase containing the prepolymer is nucleophilically used as a catalyst. Add reagent.
In the second step, after the addition of the catalyst, the organic solution phase is stirred, the reaction vessel is heated, and as an initial reflux, the solvent and moisture in the organic solution phase are refluxed for 30 to 70 minutes. Advance polymer polycondensation reaction. At this time, the water remaining in the organic solution phase containing the prepolymer and the water generated by the condensation polymerization reaction of the prepolymer are removed by the trap in the cleaning step. However, the solvent in the organic solution phase is returned to the reaction vessel, the amount of decrease in the solvent is reduced, and the concentration of reaction components such as reaction intermediates and prepolymers produced by the prepolymer polycondensation reaction is minimized. To.

  In the third step, after the second step, the cock provided in the reflux condenser is switched, and the reflux organic solvent liquefied by the cooler is discharged outside without returning to the reaction tank. The runoff amount of the organic solvent is 20 to 40% of the amount of the organic solvent in the organic solvent solution before the prepolymer condensation polymerization reaction is started.

  In the fourth step, after reducing the amount of the organic solvent in the organic solvent solution, the cock is returned to the original state, and the reaction of the reaction intermediate, prepolymer, etc. is performed while removing the generated water at the boiling temperature of the organic solvent. Advance the condensation polymerization reaction of the components to synthesize a high molecular weight silicone ladder polymer.

  The synthesized high molecular weight silicone ladder polymer is purified by a reprecipitation method, and the obtained solid content is dried to obtain a high purity high molecular weight silicone ladder polymer.

In the synthesis of the silicone ladder polymer by the conventional method using the above prepolymer, the solvent in the reaction solution is also removed in the removal of water generated by the condensation polymerization reaction, so the prepolymer and the reaction intermediate in the reaction solution are removed. As a result, the intermediate has a high degree of polymerization. Since this intermediate has low reactivity, it takes a long time to further react to obtain a high molecular weight silicone ladder polymer of 400,000 or more.
However, in the synthesis of the silicone ladder polymer of the present embodiment, moisture generated mainly by the reaction is removed at the beginning of the prepolymer condensation polymerization reaction, but the organic solvent is refluxed. Since the condensation polymerization reaction proceeds without a significant increase in the concentration, the degree of polymerization of the intermediate produced by the prepolymer reaction is not large, and the reactivity of the intermediate does not decrease. Therefore, the synthesis rate of the high molecular weight silicone ladder polymer due to the reaction between the intermediates does not decrease, and the synthesis time of the high molecular weight silicone ladder polymer can be shortened.

The phenyltrichlorosilane used in this embodiment is preferably purified in advance by distillation in a nitrogen stream under reduced pressure.
The amount of phenyltrichlorosilane dissolved in the organic solvent is preferably adjusted so that the concentration of the obtained prepolymer is 0.1 to 0.2 g / ml. When the concentration of the prepolymer is less than 0.1 g / ml, the formation reaction of the reaction intermediate is slow, the rate of the polycondensation reaction after reducing the amount of the organic solvent is slow, and the high molecular weight of the fourth step The time for synthesizing the silicone ladder polymer is the same as in the case where the amount of the organic solvent is not reduced. When the concentration of the prepolymer is greater than 0.2 g / ml, the solid content generated in the reaction solution after reducing the amount of the organic solvent adheres to the walls of the reaction tank, and the reaction rate decreases. The time for synthesizing the high molecular weight silicone ladder polymer in the fourth step cannot be shortened.

Examples of the organic solvent include ketones such as methyl isobutyl ketone and methyl ethyl ketone, ethers such as diethyl ether and isopropyl ether, and aromatic hydrocarbons such as xylene, toluene, and benzene. Industrial high purity chemicals (ELSS grade) are preferred.
Examples of the nucleophile used as a catalyst for the synthesis of the high molecular weight silicone ladder polymer include hydroxides such as K, Na, and Cs. Preferably, ELSS grade potassium hydroxide (KOH) or sodium hydroxide (NaOH) is used. The addition amount of this catalyst is 0.05-5 weight% with respect to a prepolymer.

  In the second step of synthesizing the high molecular weight silicone ladder polymer, the initial reflux time is 30 to 70 minutes. If the reflux time is less than 30 minutes, the condensation reaction between the prepolymers does not proceed. It takes a long time to obtain a high molecular weight silicone ladder polymer. In addition, if the reflux time is longer than 70 minutes, the synthesis time in the third step is not shortened, and the overall time for obtaining a high molecular weight silicone ladder polymer is extended.

  In the third step of synthesizing the high molecular weight silicone ladder polymer, 20 to 40% of the charged amount of the organic solvent in the organic solution in the reaction tank is washed away. If it exceeds 40%, the solid content generated in the reaction solution will adhere to the walls of the reaction vessel, the reaction rate will decrease, and the time for synthesizing the high molecular weight silicone ladder polymer in the fourth step may be shortened. Can not. In addition, when the organic solvent flow-off amount is less than 20%, the concentration of the produced reaction intermediate is small, the condensation reaction rate of the reaction intermediate is small, and the time for synthesizing the high molecular weight silicone ladder polymer is long. Become.

  In this embodiment, the method is a method for synthesizing a high molecular weight silicone ladder polymer using phenyltrichlorosilane as a raw material, but even if the raw material is a mixture of phenyltrichlorosilane and vinyltrichlorosilane, The synthesis time of the silicone ladder polymer can be shortened.

  Next, the present invention will be described in more detail with reference to examples.

Example 1.
One mole (211 g) of phenyltrichlorosilane is dissolved in 640 ml of ELSS grade methyl isobutyl ketone and the solution is cooled to below 0 ° C. Into the cooled solution, 320 g of pure water is dropped little by little. At this time, the added pure water reacts with the chloro group of phenyltrichlorosilane to generate hydrochloric acid and generate heat, so that pure water is dropped while taking care not to raise the temperature of the solution to 10 ° C. or higher. .
Silanol groups are present in the hydrolyzate produced by dropping pure water, and a dehydration condensation reaction occurs between them, and the hydrolyzate becomes a low molecular weight ladder-type prepolymer. To complete the reaction, stirring is continued for 2 hours at room temperature.
Next, 200 g of pure water is added to the acidic reaction solution containing the hydrolyzate, and the mixture is stirred and allowed to stand for 5 minutes. Then, the water phase of the lower phase separated is removed, and the prepolymer is washed. By repeating this washing operation five times, the washing water becomes almost neutral.

Next, a catalyst prepared by dissolving 0.78 g of ELSS grade KOH in 7.8 ml of ELSS grade methanol is prepared.
The catalyst solution is added to the washed methyl isobutyl ketone solution of the prepolymer to obtain a reaction solution. The concentration of the prepolymer in this reaction solution is 0.18 g / ml. Next, this reaction solution is heated with stirring, and the temperature is raised to about 90 ° C. Then, as the initial reflux, water begins to circulate, so the water is washed away using the Dane Stark trap. . Heating is continued for about 60 minutes while water is being washed away, but during this time, the solvent methyl isobutyl ketone is prevented from flowing out. After about 60 minutes, the temperature of the reaction solution was set to 114 ° C., which is the boiling point of the solvent methyl isobutyl ketone, and the solvent methyl isobutyl ketone started to flow out. In about 30 minutes, 20% of the charged solvent amount of the reaction solution flowed. Let go.
Thereafter, the solvent methyl isobutyl ketone is stopped from flowing out, and the heating is further continued for 1 hour 30 minutes. During this time, water flow is observed, and the dehydration condensation polymerization reaction is in progress.
That is, after performing a dehydration condensation polymerization reaction for about 3 hours in total, about 1 cc of the reaction solution was sampled, dissolved in 10 cc of tetrahydrofuran, and obtained by gel chromatography (GPC). The molecular weight was determined.
Moreover, about the silicone ladder polymer when obtained, confirmation of ladder structure was calculated | required from the measurement of SiNMR, the thermal decomposition start temperature was calculated | required from the thermogravimetric analysis (TGA) under nitrogen, and the storage stability of the solution melt | dissolved in methoxybenzene. The solution was confirmed from the presence or absence of precipitation after standing at 40 ° C. for 1000 hours.
The obtained results are shown in Table 1 together with the initial prepolymer concentration, the initial reflux time, and the organic solvent run-off amount.

Examples 2-3.
A silicone ladder polymer was synthesized in the same manner as in Example 1 except that the prepolymer concentration in the organic solvent solution of the prepolymer before the condensation polymerization was as shown in Table 1.
About the obtained silicone ladder polymer, it carried out similarly to Example 1, calculated | required the weight average molecular weight, confirmation of a ladder structure, thermal decomposition start temperature, the storage stability of a solution, the density | concentration of an initial stage prepolymer, initial stage reflux time, organic The results are shown in Table 1 along with the amount of solvent run-off.

Examples 4-5.
A silicone ladder polymer was synthesized in the same manner as in Example 1 except that the initial reflux time in the polycondensation reaction was changed to the time shown in Table 1.
About the obtained silicone ladder polymer, it carried out similarly to Example 1, calculated | required the weight average molecular weight, confirmation of a ladder structure, thermal decomposition start temperature, the storage stability of a solution, the density | concentration of an initial stage prepolymer, initial stage reflux time, organic The results are shown in Table 1 along with the amount of solvent run-off.

Example 6
A silicone ladder polymer was synthesized in the same manner as in Example 1 except that the amount of the solvent in the dehydration condensation polymerization reaction of the prepolymer was 40% of the amount of the charged solvent in the reaction solution.
About the obtained silicone ladder polymer, it carried out similarly to Example 1, calculated | required the weight average molecular weight, confirmation of a ladder structure, thermal decomposition start temperature, the storage stability of a solution, the density | concentration of an initial stage prepolymer, initial stage reflux time, organic The results are shown in Table 1 along with the amount of solvent run-off.

Example 7
A mixture (209 g) of 0.95 mol (201 g) of phenyltrichlorosilane and 0.05 mol (8 g) of vinyltrichlorosilane was dissolved in 670 ml of ELSS grade methyl isobutyl ketone, and this solution was cooled to -5 ° C or lower. To do. To this cooled solution, 280 g of pure water is dropped little by little and stirred. At this time, the added pure water reacts with the chloro group of phenyltrichlorosilane and vinyltrichlorosilane to produce hydrochloric acid and generate heat, so make sure that the temperature of the solution does not rise above 5 ° C. Add water dropwise.
The solution is then returned to room temperature and stirring is continued for 2 hours to complete the reaction that results in a low molecular weight ladder prepolymer.
Next, 280 g of pure water is added to the acidic reaction solution containing the hydrolyzate, and the mixture is stirred and allowed to stand for 5 minutes. Then, the phase-separated lower aqueous phase is removed, and the prepolymer is washed. By repeating this washing operation five times, the washing water becomes almost neutral.

Next, a catalyst prepared by dissolving 0.38 g of ELSS grade KOH in 7.8 ml of methyl alcohol is prepared.
The catalyst solution is added to the washed methyl isobutyl ketone solution of the prepolymer to obtain a reaction solution. The concentration of the prepolymer in this reaction solution is 0.19 g / ml. Next, this reaction solution is heated with stirring, and the temperature is raised to about 90 ° C. Then, since water begins to circulate, water is washed away using a Dane Stark trap. . Heating is continued for about 60 minutes while allowing water to flow away, but during this time, the solvent methyl isobutyl ketone does not flow out. After about 60 minutes, the temperature of the reaction solution was set to 114 ° C. which is the boiling point of the solvent methyl isobutyl ketone, and the flow of the solvent methyl isobutyl ketone was started. In about 30 minutes, 20% of the charged solvent amount of the reaction solution was flowed. Leave.
Thereafter, the solvent methyl isobutyl ketone is stopped from flowing out, and the heating is further continued for 5 hours 30 minutes. During this time, water flow is observed, and the dehydration condensation polymerization reaction is in progress.
That is, a dehydration condensation polymerization reaction was performed for a total of about 7 hours to synthesize a silicone ladder polymer.
About the obtained silicone ladder polymer, it carried out similarly to Example 1, and calculated | required the weight average molecular weight, the confirmation of a ladder structure, thermal decomposition start temperature, the storage stability of a solution, the density | concentration of an initial stage prepolymer, initial stage reflux time, organic The results are shown in Table 1 together with the amount of solvent run-off.

Comparative Example 1.
In the dehydration condensation polymerization reaction of the prepolymer, a silicone ladder polymer was synthesized in the same manner as in Example 1 except that the silicone ladder polymer was synthesized without removing the solvent from the reaction solution. About the obtained silicone ladder polymer, it carried out similarly to Example 1, measured the weight average molecular weight, and it showed in Table 1 with the density | concentration of the initial stage prepolymer, the initial stage reflux time, and the runoff amount of the organic solvent.

Comparative Examples 2-3.
A silicone ladder polymer was synthesized in the same manner as in Example 1 except that the prepolymer concentration in the organic solvent solution of the prepolymer before the condensation polymerization was as shown in Table 1.
About the obtained silicone ladder polymer, it carried out similarly to Example 1, measured the weight average molecular weight, and it showed in Table 1 with the density | concentration of the initial stage prepolymer, the initial stage reflux time, and the runoff amount of the organic solvent.

Comparative Examples 4-5.
A silicone ladder polymer was synthesized in the same manner as in Example 1 except that the initial reflux time in the polycondensation reaction was changed to the time shown in Table 1.
About the obtained silicone ladder polymer, it carried out similarly to Example 1, measured the weight average molecular weight, and it showed in Table 1 with the density | concentration of the initial stage prepolymer, the initial stage reflux time, and the runoff amount of the organic solvent.

Comparative Examples 6-7.
In the dehydration condensation polymerization reaction of the prepolymer, a silicone ladder polymer was synthesized in the same manner as in Example 1 except that the amount of solvent removed from the reaction solution was changed to the amount shown in Table 1. About the obtained silicone ladder polymer, it carried out similarly to Example 1, measured the weight average molecular weight, and it showed in Table 1 with the density | concentration of the initial stage prepolymer, the initial stage reflux time, and the runoff amount of the organic solvent.

Comparative Example 8.
A silicone ladder polymer was synthesized in the same manner as in Example 7 except that in the dehydration condensation polymerization reaction of the prepolymer, the silicone ladder polymer was synthesized without removing the solvent from the reaction solution. About the obtained silicone ladder polymer, it carried out similarly to Example 7, and measured the weight average molecular weight, and it showed in Table 1 with the density | concentration of the initial stage prepolymer, the initial stage reflux time, and the amount of organic solvents flowing away.

As is clear from Table 1, the prepolymer concentration of Examples 1 to 6 is 0.1 to 0.2 g / ml, the initial reflux time is 30 to 70 minutes, and the runoff amount of the organic solvent is The silicone ladder polymer synthesized under the condition that it is 20 to 40% of the amount of the organic solvent in the solution before the condensation polymerization has a weight average molecular weight of 400,000 or more due to a short synthesis time of about 3 hours. A ladder polymer was synthesized.
In addition, in the synthesis of the silicon ladder polymer using the prepolymer obtained from the mixture of phenyltrichlorosilane and vinyltrichlorosilane in Example 7, the weight average molecular weight is about 400,000 or more by synthesis for about 7 hours. was gotten.
The obtained silicone ladder polymer had a ladder structure, had a thermal decomposability of 450 ° C. or higher, and was excellent in storage stability when made into a methoxybenzene solution.

On the other hand, in the case of Comparative Examples 1 to 7, the weight average molecular weight of the silicon ladder polymer obtained by the synthesis for about 3 hours is 280,000 at the maximum. And the synthesis time becomes longer.
In the case of Comparative Example 8 as well, the weight average molecular weight of the silicon ladder polymer obtained by the synthesis for about 7 hours is 220,000, and it is necessary to continue the synthesis in order to increase it to 400,000 or more. Becomes longer.

  That is, in the synthesis of the silicon ladder polymer by the method of the present invention, the time for synthesizing the high molecular weight silicon ladder polymer can be shortened compared to the conventional method.

Claims (2)

A method for producing a silicone ladder polymer in which a prepolymer obtained by hydrolyzing trichlorosilane is synthesized by condensation polymerization,
Adjusting the concentration of the prepolymer in the organic solvent solution of the prepolymer before the condensation polymerization to 0.1 to 0.2 g / ml;
Heating the organic solvent solution of the prepolymer and refluxing the water generated by the condensation polymerization of the prepolymer and the organic solvent for 30 to 70 minutes, and removing the water in the reflux liquid; After the step, the organic solvent is washed away, and 20-40% of the amount of the organic solvent in the organic solvent solution of the prepolymer before the condensation polymerization starts, and
A method for producing a silicone ladder polymer, comprising a step of proceeding condensation polymerization at a boiling temperature of the organic solvent after the organic solvent flow-off step. The method for producing a silicone ladder polymer according to claim 1, wherein the trichlorosilane is phenyltrichlorosilane or a mixture of phenyltrichlorosilane and vinyltrichlorosilane.