JP2000086766A - Production of cyclic polysiloxane containing si-h - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently obtain the subject compound useful for silicone resins or silicone rubbers by mixing a specific polysiloxane with a solid acidic catalyst and water in specific amounts, respectively, heating the mixture and subsequently distilling out the produced compound. SOLUTION: This method for producing a Si-H bond-containing cyclic polysiloxane comprises adding 0.05-20 pts.wt. of a solid acidic catalyst, preferably acidic zeolite, and 0.1-30 pts.wt. of water to 100 pts.wt. of a polysiloxane (for example, a compound of formula III) comprising a linear polysiloxane of formula I [R1 is a monovalent hydrocarbon; R2 is a monovalent hydrocarbon, OH or the like; (n), (m) are each an average polymerization degree, 0<=(n), 0<=(m), and 0<=(n)+(m)<=500] and/or a cyclic polysiloxane of formula II [0<(p)<=10, 0<=(q)<=, and 5<=(p)+(q)<=10] (for example, a compound of formula III), heating the mixture preferably at about 25-120 deg.C and subsequently distilling out the Si-H bond-containing cyclic polysiloxane of formula IV [0<(r)<=10; 0<<=(s)<=10; 3<=(r)+(s)<=10] preferably at a 50-120 deg.C under a reduced pressure of <=300 mmHg.

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 a Si-H-containing cyclic polysiloxane used as a raw material for a silicone resin or silicone rubber.

[0002]

2. Description of the Related Art As a method of synthesizing a cyclic polysiloxane,
There are (1) a method using a hydrolyzate of chlorosilane, and (2) a method using cracking of a siloxane oligomer or a polysiloxane having a higher degree of polymerization than the oligomer.

(1) In the method based on the hydrolysis of chlorosilane, the rate of formation of cyclic polysiloxane is low. Also, S
In the case of hydrolysis of a chlorosilane containing an iH bond, the yield is further reduced. In order to improve the yield, there is a method of using ether as a solvent, but there is a problem that the ether has a low flash point and a high danger when manufactured in a factory.

(2) As a method based on cracking of siloxane oligomers and polysiloxanes, the production of cyclic polysiloxanes by thermally decomposing polydimethylsiloxane in the presence of caustic soda is a journal of journal.
he American Chemical Soci
ety 1946, Vol. 68, p. 667, Hunter
And so on. A method using a transition element complex with a complex containing rhodium or iridium is described in Jour.
nal of OrganometallicChem
Gust in 1982, Vol. 87, page 238.
avson et al. [(CH ₃ ) ₂
Regarding the method for producing cyclic diorganosiloxanes including SiO] ₄ , JP-B-33-2149 and JP-B-35-4240 cracking of a hydrolyzate of dimethyldichlorosilane using an alkali catalyst,
A method for obtaining a cyclic diorganosiloxane is exemplified.

[0005] However, in the case of a siloxane containing a Si-H bond, the dehydrogenation reaction proceeds by contact with an alkali catalyst to generate hydrogen. The generation of hydrogen is very dangerous.

As a cracking method using an acidic catalyst, Japanese Patent Publication No. 55-11697 discloses a method in which a siloxane containing a Si—H bond is added to activated clay heated to about 300 ° C. Siloxane containing a Si-H bond is very dangerous because the dehydrogenation reaction may proceed by heating to 300 ° C.

In Japanese Patent Publication No. 6-86469, 200
A method in which a siloxane containing a Si—H bond is dropped onto the bottom of an acidic solid catalyst such as acid-treated bentonite, clay, sulfuric acid-treated molecular sieve, acidic zeolite, or the like heated to at least ℃. However, the heating temperature is high and the reactants may gel.

The production method under the condition that the heating temperature is relatively low is described in JP-B-59-29195 and JP-A-7-24.
2678. In both cases, sulfuric acid is used. However, sulfuric acid may be partially decomposed during distillation under reduced pressure and migrate to the product to lower the purity of the product. The decomposition product of sulfuric acid may react with the cyclic polysiloxane and gel.

US Pat. No. 5,247,116 exemplifies a method using trifluoromethanesulfonic acid, but has the drawback that the yield per single reaction is low and the production efficiency is low.

In Japanese Patent Publication No. 54-13480, 80 ° C.
A method using activated clay as a reaction acidic catalyst under an atmosphere of 170 ° C. is exemplified. However, there is a drawback that a large amount of water is added to easily gel.

Thus, an efficient method for synthesizing a cyclic polysiloxane containing a Si—H bond has been desired.

[0012]

As described above, in the conventional method for producing a cyclic polysiloxane containing a Si—H bond, the yield is low in the hydrolysis of chlorosilane, and hydrogen is not used in the recipe called alkali cracking. There is a problem that generation is feared and dangerous, and cracking with an acidic catalyst has a problem that a heating reaction temperature is too high and a side reaction is likely to occur, and a synthesis method with high reaction efficiency has been desired.

Accordingly, the present invention provides a method for producing Si-
An object of the present invention is to provide a method for producing a cyclic polysiloxane having an H bond.

[0014]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a linear acidic polysiloxane is used as a catalyst,
Further, by adding a small amount of water, a method for efficiently producing a cyclic polysiloxane having a Si—H bond was found, and the present invention was completed.

The method for producing the Si—H-containing cyclic polysiloxane of the present invention is represented by the general formula (I):

Embedded image (Wherein, R ¹ is the same or different monovalent hydrocarbon group, R ²
Represents the same or different monovalent hydrocarbon group, hydroxyl group or hydrogen atom, n and m represent the average degree of polymerization, 0 ≦ n, 0
≦ m, 0 ≦ n + m ≦ 500, and / or a linear polysiloxane represented by the general formula (I
I)

Embedded image (Wherein R ¹ represents a monovalent hydrocarbon, R ^{1 in} each unit may be the same or different, and p and q are 0 <p ≦ 1
0, 0 ≦ q ≦ 10, and an integer such that 5 ≦ p + q ≦ 10) is added to 100 parts by weight of the polysiloxane comprising the cyclic polysiloxane,
(A) adding 0 parts by weight and 0.1 to 30 parts by weight of water and heating;

Embedded image (Wherein R ¹ represents a monovalent hydrocarbon, R ^{1 in} each unit may be the same or different, and r and s are 0 <r ≦ 1
(Indicating an integer such that 0, 0 ≦ s ≦ 10 and 3 ≦ r + s ≦ 10) (b).

That is, the present invention provides a method for efficiently producing a cyclic polysiloxane mixture of trimers and trimers containing Si-H from Si-H-containing linear polysiloxanes.

Hereinafter, the present invention will be described in detail.

In the chain polysiloxane represented by the formula (I), R ¹ is a monovalent hydrocarbon, and each R ¹ may be the same or different. Preferred as the monovalent hydrocarbon group are groups relatively stable to heat and acid, such as an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, and an aryl group.

Particularly preferred are C ₁ -C ₈ alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl and hexyl; C ₂ -C ₈ cycloalkyl groups such as cyclohexyl; a C ₂ -C ₈ alkenyl group; C ₃ -C ₈ cycloalkenyl groups such as cyclohexenyl group; a monocyclic aryl radical (C ₁ -C ₈ alkyl group as defined above such as phenyl groups, C
_A C ₂ -C ₈ cycloalkyl group, a C ₂ -C ₈ alkenyl group or a C ₃ -C ₈ cycloalkenyl group). Of these, a methyl group is particularly preferred.

R ² in the formula (I) is a monovalent unsubstituted or substituted hydrocarbon group, hydroxyl group or hydrogen atom, and each R ² may be the same or different.

As the monovalent unsubstituted hydrocarbon group, an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an alkynyl group, a cycloalkynyl group and a monocyclic aryl group are preferred.

Particularly preferred are C ₁ such as methyl, ethyl, n-propyl, isopropyl, n-butyl, secondary butyl, isobutyl, tertiary butyl, pentyl, hexyl, heptyl and octyl.
Vinyl, C ₂ -C ₈ alkenyl groups such as allyl and n- hexenyl;; C _3, such as cyclohexenyl group C ₃ -C ₈ cycloalkyl groups such as cyclopentyl and cyclohexyl: -C ₈ alkyl group C ₈ -C ₁₂ cycloalkynyl groups such as cyclooctynyl group;; C ₂ ~C ₈ alkynyl groups such as propargyl; -C ₈ cycloalkenyl and phenyl, and the like monocyclic aryl such as tolyl it can.

Examples of the monovalent substituted hydrocarbon group include those in which the above hydrocarbon group is substituted with C ₁ -C ₈ alkyl or halogen.

In the formula (I), n and m indicate the average degree of polymerization.
(N + m) is an integer of 0 to 500. If it exceeds 500, the increase in viscosity becomes large and it becomes difficult to handle, and (n +
When m) is relatively small, for example, around 7, the content ratio of both terminal groups becomes high, and the ratio of the linear low-molecular siloxane mixed as a by-product in the reaction for obtaining a cyclic polysiloxane described later. Therefore, (n + m) is preferably about 20 to 100.

In the present invention, the following are specific examples of the linear polysiloxane represented by the formula (I). In the following chemical formula, Me is a methyl group, Et
Represents an ethyl group, and Ph represents a phenyl group.

[0026]

Embedded image The cyclic polysiloxane represented by the formula (II) is a 5- to 10-membered cyclic polysiloxane.

R ^{1 in} formula (II) is a monovalent hydrocarbon;
They may be the same or different. Preferred as the monovalent hydrocarbon group are groups relatively stable to heat and acid, such as an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, and an aryl group.

Particularly preferred are C ₁ -C ₈ alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl and hexyl; C ₂ -C ₈ cycloalkyl groups such as cyclohexyl; a C ₂ -C ₈ alkenyl group; C ₃ -C ₈ cycloalkenyl groups such as cyclohexenyl group; a monocyclic aryl radical (C ₁ -C ₈ alkyl group as described above, such as phenyl groups, C
_A C ₂ -C ₈ cycloalkyl group, a C ₂ -C ₈ alkenyl group or a C ₃ -C ₈ cycloalkenyl group). Of these, a methyl group is particularly preferred.

Specific examples of the cyclic polysiloxane represented by the formula (II) include those represented by the following chemical formula.

[0030]

Embedded image

Embedded image

Embedded image The cyclic polysiloxane represented by the formula (II) may be used as a mixture of two or more kinds.

In the polysiloxane used as a raw material in the method for producing a Si—H-containing cyclic polysiloxane of the present invention, the chain polysiloxane is x parts by weight (0 <x <100).
And the cyclic polysiloxane is y parts by weight (0 <
y <100, where x + y = 100).

When only the cyclic polysiloxane represented by the formula (II) is used, the ring-opening reaction proceeds with an acidic catalyst, so that the reaction product becomes a polymer and the viscosity becomes too high, or the reaction vessel gels. May occur. Therefore, it is preferable to use a chain polysiloxane represented by the formula (I) having a terminal group in combination. When the terminal group of the linear siloxane represented by the formula (I) is substituted by a group having a relatively small molecular weight such as a methyl group and hydrogen, the formula (I) is preferably 5 parts by weight or more.

According to the invention, step (a) is carried out at a temperature of about 2
It is performed at a temperature of 5 ° C to 120 ° C. When the temperature exceeds 120 ° C., a side reaction is likely to proceed, and the viscosity of the reaction solution may increase, or the reaction solution may gel, and the yield may decrease. In particular, a preferred temperature is between 50C and 100C.

Examples of the solid acidic catalyst used in the present invention include acidic zeolite, acidic zeolite molecular sieve, acid-treated clay mineral, acid-treated porous desiccant, and ion-exchange resin.

That is, the acidic solid catalyst is prepared by adding an acidic zeolite such as HY, an acidic zeolite molecular sieve having a pore size of about 5 to about 20 ohm strong, a clay mineral such as silica alumina, silica magnesia, montmorillonite or halloysite to an acid such as sulfuric acid. Treatment, porous desiccant such as silica gel or alumina gel, hydrochloric acid, sulfuric acid, phosphoric acid, organic acid, BF ₃ etc., or sulfonated divinylbenzene / styrene copolymer And ion-exchange resin-based acidic catalysts.

With respect to 100 parts by weight of the raw material of the chain polysiloxane represented by the formula (I) and / or the cyclic polysiloxane represented by the formula (II), the addition amount of the solid catalyst is 0.05 to 500 parts by weight. 20 parts by weight. When the amount is more than 20 parts by weight, not only is it uneconomical, but also a side reaction proceeds, and the viscosity of the reaction solution may increase or gel, and the yield may decrease. If less than 0.05 parts by weight,
There are drawbacks in that the reaction efficiency is low and the reaction time is long.

The preferable addition amount is affected by the acidity of the solid acidic catalyst. For example, in the case of sulfuric acid treatment of a montmorillonite clay mineral, 3 to 10 parts by weight of a sulfonated divinylbenzene / styrene copolymer is used. In the system ion exchange resin, 1 to 5 parts by weight is preferable. Depending on the reaction conditions, two or more of these solid acidic catalysts may be used in combination.

In the present invention, the water in the step (a) means not only water to be newly added but also water contained in the raw materials of the chain polysiloxane, the cyclic polysiloxane and the solid acidic catalyst and the water of the reactor. It also contains moisture mixed from the atmosphere.

For example, in the case of a clay mineral such as montmorillonite or halloysite which has been subjected to an acid treatment, the moisture content varies depending on conditions such as the type of the clay mineral, acid treatment conditions, and storage conditions. The time is about 7-8% by weight in 100g and 10% at 90% humidity.
It is said that 0 g contains about 40 to 50% by weight of water. It is said that a sulfonated ion exchange resin of divinylbenzene / styrene copolymer used as an acidic catalyst contains about 0.1 to 3% of water.

The amount of water to be added is 0.1 part by weight to 30 parts by weight based on 100 parts of the raw material of the chain polysiloxane represented by the formula (I) and / or the charged amount of the formula (II). If the amount is more than 30 parts by weight, the side reaction may proceed, and the viscosity of the reaction solution may increase or gel, and the yield may decrease. If the amount is less than 0.1 part by weight, the reaction efficiency decreases and the reaction time becomes longer.

As a method for adding water, there is a method of adding the whole amount at the start of the reaction, a method of adding the solution at regular intervals, or a method of continuously adding the water, and any method is possible. Above all, a method of adding at regular intervals is preferable. For example, a method of adding three times or more at intervals of 5 to 60 minutes is preferable because gelation and the like are suppressed.

According to the present invention, the step (b) is carried out at 50 ° C.
The reaction is performed at a temperature of 120 ° C. and a reduced pressure of 300 mmHg or less. When the heating temperature is lower than 50 ° C., the distillation rate of the cyclic polysiloxane becomes slow. On the other hand, when the temperature is higher than 120 ° C., a side reaction may proceed, and the viscosity of the reaction solution may increase, or the reaction solution may be gelled, and the yield may decrease. In addition, by performing the reaction under reduced pressure, an increase in viscosity or gelation due to a side reaction is suppressed, and a desired product can be obtained with a high yield.

The degree of pressure reduction is determined by the apparatus and the boiling point of the target cyclic substance. In the case of a cyclic polysiloxane having a 4- to 6-membered ring as the product,
If the pressure is reduced at a pressure lower than 0.01 mmHg, it is necessary to take measures such as cooling the temperature of the trap with liquid nitrogen or the like. Therefore, the pressure is preferably 0.01 mmHg to 30 mmHg as a manufacturing condition.

According to the present invention, the steps (a) and (b) may be performed continuously using one manufacturing apparatus, or may be performed using a manufacturing apparatus in which the reaction apparatus and the distillation apparatus are separated. Absent.

The method of adding the solid acidic catalyst and water to the linear polysiloxane which is a raw material may be either a batch type or a continuous type.

To adjust the viscosity, toluene,
It may be diluted with an organic solvent such as n-hexane.
Further, in order to adjust the ratio of Si—H bonds in the product,
A chain polysiloxane having no Si—H bond may be added to the raw material.

[0047]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail.

[Example 1] A thermometer, a stirrer, a distilling tube, a cooler, and a distillate collection receiver were attached to a 4-liter 1-liter round bottom flask, and connected to a vacuum pump for reducing pressure. 1 k of polymethylhydrogensiloxane (molecular weight 3000, viscosity 25 cSt / 25 ° C.) having trimethylsilyl at both ends in a flask
g, Rohm and Haas AMBERL
20 g of YST 15 DAY (ion exchange resin) was added and heated to 50 ° C.

Next, the pressure inside the system was reduced to 10 mmHg, and the temperature was raised in the oil bath of the flask while stirring at a stirring speed of 200 rpm. When the temperature exceeded 50 ° C., low molecular cyclic polysiloxane was distilled out.

The temperature of the kettle was set to 80 ° C., and 1 g of water was added every 30 minutes. This condition was maintained for 10 hours.

When about 770 ml of distillate was obtained, the distillation was completed, and an oil and a solid acidic catalyst having a slightly increased viscosity remained in the reaction vessel.

As a result of the measurement, 750 g of a distillate (distillation rate: 7
5% by weight), and the residue in the reactor was about 200 g.

Gas chromatography of the distillate (hereinafter G
According to the analysis results, the distillate had a cyclic polysiloxane composition of 2,4,6-trimethylcyclotrisiloxane (cyclic trimer) of 2% by weight, 2,4,6,8-tetramethyl Cyclotetrasiloxane (cyclic tetramer) is 60
25% by weight of 2,4,6,8,10-pentamethylcyclopentasiloxane (cyclic pentamer)
6,8,10,12-hexamethylcyclohexasiloxane (cyclic hexamer) was 8% by weight, and other cyclic polysiloxane was 5% by weight.

Example 2 A thermometer, a stirrer, a distilling tube, a cooler, and a distillate collection receiver were attached to a 1-liter round bottom four-necked flask, and connected to a vacuum pump for reducing pressure. A flask was charged with 1 kg of trimethylsilyl polymethylhydrogensiloxane at both ends (molecular weight 3000, viscosity 25 cSt / 25 ° C.), and a solid acidic catalyst (active clay, manufactured by Kanto Chemical Co., Ltd .; (Reagent grade) was added and heated to 50 ° C.

Next, the pressure inside the system was reduced to 10 mmHg, and the temperature was raised in an oil bath of the flask while stirring at a stirring speed of 200 rpm. When the temperature exceeded 60 ° C., low-molecular cyclic polysiloxane was distilled out.

The temperature of the kettle was set to 80 ° C., and water was added by 1 g every 30 minutes. This condition was maintained for 10 hours.

When about 600 ml of distillate was obtained, the distillation was completed, and the oil and the solid acidic catalyst with slightly increased viscosity remained in the reaction vessel.

As a result of the measurement, 560 g of a distillate (distillation rate: 5
6% by weight), and the residue in the reactor was about 400 g. From the result of GC analysis of the distillate, the composition of the distillate from the cyclic polysiloxane was as follows: 2,4,6-trimethylcyclotrisiloxane (cyclic trimer) was 5% by weight, 2,4,6,8- 52% by weight of tetramethylcyclotetrasiloxane (cyclic tetramer), 31% by weight of 2,4,6,8,10-pentamethylcyclopentasiloxane (cyclic pentamer), 2,4,4
6,8,10,12-hexamethylcyclohexasiloxane (cyclic hexamer) was 8% by weight, and other cyclic polysiloxane was 4% by weight.

[Example 3] In Example 1, a chain polysiloxane having an average molecular formula shown below was used as a chain siloxane as a raw material. The synthesis conditions were as in Example 1.
Is the same as

[0060]

Embedded image As a result of the measurement, distillate was 650 g (distillation rate 65% by weight),
The residue in the reactor was about 300 g. According to the result of GC analysis of the distillate, the composition of the distillate with the cyclic polysiloxane was 6% by weight of the cyclic trimer siloxane, 60% of the cyclic tetramer siloxane, 26% of the cyclic hexamer, The content of other cyclic siloxane was 8% by weight.

Comparative Example 1 Under the same conditions as in Example 1, polymethylhydrogensiloxane having a trimethylsilyl group at both ends (molecular weight 3000, viscosity 25 cSt / 2)
(5 ° C.) to a water content of 100 ppm or less.

Next, AMB manufactured by Rohm and Haas Company
ERLYST 15 DRY (ion exchange resin) 10
Heating was performed under the conditions of 0 ° C./72 hours to perform dehydration. Using this dehydrated material, pay attention to the mixing of moisture in the air,
The experiment of Example 1 was performed. No water was added.

After heating for 10 hours, the mixture was cooled and the weight of the distilled cyclic polysiloxane was measured. The weight of the distilled cyclic polysiloxane was 750 g in Example 1 and 120 g in Comparative Example 1. Thus, it was found that the yield was improved by adding water.

Example 4 A thermometer, a stirrer, a distilling tube, a cooler, and a distillate collection receiver were attached to a 1-liter round bottom four-necked flask, and connected to a vacuum pump for reducing pressure.

In a flask, 2,4,6,8,10-pentamethylcyclopentasiloxane, hexamethylcyclohexasiloxane, 2,4,6,8,10,12,14-
Heptamethylcycloheptasiloxane (composition ratio 60wt
%, 30 wt%, 10 wt%) in a mixture of 950 g,
50 g of 1,3-dioctyl-1,1,3,3-tetramethyldisiloxane was charged, and AMBERLYST15 DRY (ion exchange resin) manufactured by Rohm and Haas Company.
Was added and heated to 50 ° C.

Next, the pressure in the system was reduced to 200 mmHg, and the temperature was raised in an oil bath of the flask while stirring at a stirring speed of 200 rpm. After setting the kettle temperature at 80 ° C. and heating for 2 hours, the pressure was reduced to 10 mmHg, and water was added in 1 g portions every 30 minutes. This condition was maintained for 8 hours.

When about 800 ml of distillate was obtained, the distillation was stopped, and a slightly increased viscosity of the oil and a solid acidic catalyst remained in the reaction vessel.

As a result of the measurement, the amount of distillate was 770 g (distillation rate 7
7% by weight), and the residue in the reactor was about 200 g. From the result of GC analysis of the distillate, the composition of the cyclic polysiloxane in the distillate was as follows: 2,4,6-trimethylcyclotrisiloxane (cyclic trimer) was 5% by weight, 2,4,6,8- 65% by weight of tetramethylcyclotetrasiloxane (cyclic tetramer), 23% by weight of 2,4,6,8,10-pentamethylcyclopentasiloxane (cyclic pentamer), 2,4,4
6,8,10,12-hexamethylcyclohexasiloxane (cyclic hexamer) was 5% by weight, and other siloxane was 2% by weight.

Example 5 A thermometer, a stirrer, a distilling tube, a cooler, and a distillate collection receiver were attached to a 1-liter round bottom four-necked flask, and connected to a vacuum pump for reducing pressure.

In a flask, 2,4,6,8,10-pentamethylcyclopentasiloxane, 2,4,6,8,1
0,12-hexamethylcyclohexasiloxane, 2,
4,6,8,10,12,14-Heptamethylcycloheptasiloxane (composition ratio 60 Wt%, 30 Wt%, 10 Wt%
%) Of a mixture of polymethylhydrogensiloxane having a trimethylsilyl group at both terminals (molecular weight: 3%).
200g, viscosity 25 cSt / 25 ° C), 200 g of Rohm and Haas AMBERLYST 15DR
20 g of Y (ion exchange resin) was added and heated to 60 ° C.

Next, the pressure in the system was reduced to 200 mmHg, and the temperature was increased in an oil bath of the flask while stirring at a stirring speed of 200 rpm. After setting the kettle temperature at 80 ° C. and maintaining the temperature for 2 hours, the pressure was reduced to 10 mmHg, and water was added in 1 g portions every 30 minutes. This condition was maintained for 8 hours.

When about 700 ml of distillate was obtained, the distillation was completed, and an oil and a solid acidic catalyst having a slightly increased viscosity remained in the reaction vessel.

As a result of the measurement, 680 g of a distillate (distillation rate: 6
8% by weight), and the residue in the reactor was about 300 g. From the result of GC analysis of the distillate, the composition of the distillate was 2, 4, 6
5 trimethylcyclotrisiloxane (cyclic trimer)
%, 2,4,6,8-tetramethylcyclotetrasiloxane (cyclic tetramer) was 58% by weight,
8,10-pentamethylcyclopentasiloxane (cyclic pentamer) is 23% by weight, 2,4,6,8,10,12-
Hexamethylcyclohexasiloxane (cyclic hexamer) was 6% by weight, and other siloxane was 8% by weight.

Example 6 In Example 2, a solid acidic catalyst (manufactured by Kanto Kagaku Co., Ltd., activated clay) obtained by subjecting a mineral mainly composed of montmorillonite as an acidic solid catalyst to sulfuric acid treatment was used.
40 g of reagent grade). The reaction conditions are the same as in Example 1. Distillation was stopped when about 500 ml of distillate was obtained, and a slightly increased oil and solid acidic catalyst remained in the reaction vessel.

As a result of the measurement, the amount of distillate was 480 g (distillation rate 4
8% by weight), and the residue in the reactor was about 500 g. From the result of GC analysis of the distillate, the cyclic polysiloxane composition of the distillate was as follows: 2,4,6-trimethylcyclotrisiloxane (cyclic trimer) was 4% by weight, 2,4,6,8- 55% by weight of tetramethylcyclotetrasiloxane (cyclic tetramer), 28% by weight of 2,4,6,8,10-pentamethylcyclopentasiloxane (cyclic pentamer), 2,4,4
6,8,10,12-hexamethylcyclohexasiloxane (cyclic hexamer) was 3% by weight, and the cyclic polysiloxane was 10% by weight.

[Comparative Example 2] Under the conditions of Example 1,
2,4,6,8,10-pentamethylcyclopentasiloxane, 2,4,6,8,10,12-hexamethylcyclohexasiloxane, 2,4,6,8,10,12,
14-heptamethylcycloheptasiloxane (composition ratio 6
0 Wt%, 30 Wt%, 10 Wt%) and 1,
3-Dioctyl-1,1,3,3-tetramethyldisiloxane was dehydrated and dried to a water content of 100 ppm or less.

Next, AMB manufactured by Rohm and Haas Company
1 ERLYST 15 DRY (ion exchange resin)
Heating was performed under the condition of 00 ° C./72 hours to perform dehydration. Using this dehydrated material, the experiment of Example 1 was performed while paying attention to the incorporation of moisture in the air. No water was added. The temperature was maintained for 8 hours under the condition of a kettle temperature of 80 ° C. and a degree of reduced pressure of 10 mmHg, and the weight of the cooled 4-membered cyclic polysiloxane was measured.

The weight of the distilled cyclic polysiloxane was about 770 g in Example 1 whereas about 14 g in Comparative Example 2.
It was 0 g. Thus, it was found that the yield was improved by adding water.

[0079]

According to the present invention, a solid acidic catalyst, and
By adding water, it is possible to react at a relatively low temperature, and it is difficult to gel due to a relatively small amount of added water, and there is little transfer of the acidic catalyst to the product,
A cyclic polysiloxane containing a Si—H bond can be obtained efficiently.

[0080]

Claims (8)

[Claims] 1. A compound of the general formula (I) (Wherein, R ¹ is the same or different monovalent hydrocarbon group, R ²
Represents the same or different monovalent hydrocarbon group, hydroxyl group or hydrogen atom, n and m represent the average degree of polymerization, 0 ≦ n, 0
≦ m, 0 ≦ n + m ≦ 500, and / or a linear polysiloxane represented by the general formula (I
I) (Wherein R ¹ represents a monovalent hydrocarbon, R ^{1 in} each unit may be the same or different, and p and q are 0 <p ≦ 1
0, 0 ≦ q ≦ 10, and an integer such that 5 ≦ p + q ≦ 10) is added to 100 parts by weight of the polysiloxane comprising the cyclic polysiloxane,
(A) heating by adding 0 parts by weight and 0.1 to 30 parts by weight of water; (Wherein R ¹ represents a monovalent hydrocarbon, R ^{1 in} each unit may be the same or different, and r and s are 0 <r ≦ 1
And (b) an integer which satisfies 0, 0 ≦ s ≦ 10, and 3 ≦ r + s ≦ 10).
A method for producing an iH-containing cyclic polysiloxane. 2. The polysiloxane contains x parts by weight (0 <x <100) of the chain polysiloxane and y parts by weight (0 <y <10) of the cyclic polysiloxane.
0, wherein x + y = 100). The method for producing a Si—H-containing cyclic polysiloxane according to claim 1, wherein 3. The Si-H according to claim 1, wherein said step (a) is performed at a temperature of about 25 ° C. to 120 ° C.
A method for producing a cyclic polysiloxane. 4. The solid acidic catalyst is an acidic zeolite,
The method for producing a Si-H-containing cyclic polysiloxane according to claim 1, wherein the method is an acidic zeolite molecular sieve, an acid-treated clay mineral, an acid-treated porous desiccant, or an ion-exchange resin. 5. The water according to claim 1, wherein the water includes not only newly added water but also water contained in the chain polysiloxane, the cyclic polysiloxane, and the solid acidic catalyst. A method for producing a Si-H-containing cyclic polysiloxane according to the above. 6. The method for producing a Si—H-containing cyclic polysiloxane according to claim 1, wherein the step (b) is performed at a temperature of 50 ° C. to 120 ° C. under a reduced pressure of 300 mmHg or less. 7. The method according to claim 1, wherein the step (a) and the step (b) are continuously performed using one manufacturing apparatus, or separately performed using different manufacturing apparatuses. The method for producing a Si—H-containing cyclic polysiloxane according to (1). 8. The method according to claim 1, wherein a method of adding the solid acidic catalyst and the water to the linear polysiloxane is a batch type or a continuous type. .