JPH0587088B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a method for producing an amino group-containing polysiloxane, which can synthesize an amino group-containing polysiloxane having a small molecular weight distribution and a low viscosity at a low temperature and in a short time. Conventional techniques and problems to be solved by the invention Conventionally, as a method for producing amino group-containing polysiloxane, one or more cyclic organopolysiloxanes and aminopropyl disiloxane are combined with an alkali metal oxide or hydroxide. substance, alkoxide,
Amino group-containing polyamides are produced by bringing them into contact with basic substances such as alkali metal-containing compounds such as aryl oxides and silanolates, quaternary ammonium compounds, and quaternary phosphonium compounds, and heating and raising the temperature to proceed with the ring-opening reaction. Methods for obtaining siloxane have been proposed. However, in the above method, when an alkali metal-containing compound is used as the basic catalyst, it is necessary to carry out the polymerization reaction at a relatively high temperature for a long time using a high concentration of the alkali metal-containing compound. For this reason, a large amount of salt is generated during neutralization after synthesis of amino group-containing polysiloxane, making it difficult to filter and remove the salt to obtain amino group-containing polysiloxane. The ≡Si-C≡ bond between the bonded organic salt is broken, and the resulting high molecular weight organopolysiloxane becomes branched, cross-linked or gelled, and the molecular weight distribution changes. It has been difficult to obtain a small and low viscosity amino group-containing polysiloxane. Furthermore, when using quaternary ammonium compounds or quaternary phosphonium compounds as basic catalysts, these compounds have low activity, so it is necessary to heat them to quite high temperatures to proceed with the polymerization reaction. Because it rapidly decomposes into inert volatile substances at high temperatures, it is necessary to add a basic catalyst from time to time or continuously over time, which is not only complicated but also economically disadvantageous. It had the disadvantage of being. As described above, the above method has many problems, and therefore it has been difficult to industrially advantageously produce amino group-containing polysiloxanes. The present invention has been made in view of the above-mentioned circumstances, and has an amino group-containing polysiloxane, in particular, an amino group-containing polysiloxane that can be industrially advantageously produced at a low temperature and in a short time, having a small molecular weight distribution and a low viscosity. An object of the present invention is to provide a method for producing polysiloxane containing polysiloxane. Means and Effects for Solving the Problems As a result of extensive studies to achieve the above object, the inventor has found the following general formula ()

[Chemical formula] (However, in the formula, R ¹ and R ² are each the same or different unsubstituted or substituted monovalent hydrocarbon groups,
l is an integer of 3 or more. ) Cyclic organopolysiloxane represented by the following general formula ()

[Chemical formula] (However, in the formula, R ³ and R ⁴ are each the same or different unsubstituted or substituted monovalent hydrocarbon groups,
m is an integer from 1 to 6. ) is heated in the presence of at least one basic catalyst selected from alkali metal oxides, hydroxides, alcoholates, aryl oxides, and silanolates to carry out an equilibration reaction. In proceeding with the above basic catalyst, cyclic polyether, especially the following general formula ()

[Chemical formula] (However, in the formula, R is an unsubstituted or substituted divalent hydrocarbon group, and n is an integer of 3 or more.) By adding a cyclic polyether represented by the formula, a basic catalyst can be added. Even if the amount is reduced to less than half of the normal amount, the equilibration reaction between the cyclic organopolysiloxane of formula () and the aminoalkyldisiloxane of formula () proceeds effectively at low temperature and in a short time, and the amino acid used for end-capping The scission reaction of the alkyldisiloxane and the ring-opening reaction of the cyclic organopolysiloxane that forms the main chain proceed in a well-balanced manner and reach a more complete equilibrium state, making it possible to synthesize a low-viscosity amino group-containing polysiloxane with a narrow molecular weight distribution. ,
Moreover, since the amount of basic catalyst added can be kept small, there is little salt formation even when neutralized after the above equilibrium reaction is completed, and the formed salt can be easily filtered and removed to easily produce the desired amino group-containing polysiloxane. The present inventors have discovered that it can be collected, and have come up with the present invention. Therefore, the present invention provides a mixture of a cyclic organopolysiloxane of the above general formula () and an aminoalkyldisiloxane of the above general formula () selected from alkali metal oxides, hydroxides, alcoholates, aryl oxides and silanolates. Provided is a method for producing an amino group-containing polysiloxane, which comprises heating to cause an equilibration reaction in the presence of at least one basic catalyst and a cyclic polyether. The present invention will be explained in more detail below. The cyclic organopolysiloxane used as a starting material in the present invention has the following formula ()

embedded image In the formula, R ¹ and R ² are the same or different unsubstituted or substituted monovalent hydrocarbon groups, and l is an integer of 3 or more. Here, R ¹ and R ² are, for example, a methyl group,
Alkyl groups such as ethyl, propyl and octyl groups, cycloalkyl groups such as cyclohexyl and cycloheptyl groups, alkenyl groups such as vinyl, allyl and cyclohexenyl groups, aryl groups such as phenyl and diphenyl groups, and benzyl groups. group, aralkyl group such as phenylethyl group, 3,
3,3-Trifluoropropyl group, halogenated alkyl group such as chloromethyl group, halogenated aryl group such as chlorophenyl group, dibromophenyl group, cyanomethyl group, 2-cyanoethyl group, 3
Examples include cyanoalkyl groups such as -cyanopropyl group. Specifically, such cyclic organopolysiloxanes include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, 1,3,
Examples include 5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane. The cyclic organopolysiloxane as the starting material may be used alone or as a mixture of two or more. Furthermore, a low molecular weight linear diorganopolysiloxane or a silane compound may be mixed with one or more of these cyclic organopolysiloxanes as a starting material, but in this case, the cyclic organopolysiloxane of formula () Preferably, the proportion of organopolysiloxane is at least 40% by weight. In addition, the other starting material, aminoalkyldisiloxane, has the following general formula ()

In the formula, R ³ and R ⁴ are the same or different unsubstituted or substituted monovalent hydrocarbon groups, and m is an integer of 1 to 6. Here, the substituents R ³ and R ⁴ include, for example, alkyl groups such as methyl group, ethyl group, propyl group, and octyl group, cycloalkyl groups such as cyclohexyl group and cycloheptyl group, vinyl group, allyl group, and cyclohexenyl group. Alkenyl groups such as groups, aryl groups such as phenyl groups and diphenyl groups, aralkyl groups such as benzyl groups and phenylethyl groups,
3,3,3-trifluoropropyl group, halogenated alkyl group such as chloromethyl group, halogenated aryl group such as chlorophenyl group, dibromophenyl group, dianomethyl group, 2-cyanoethyl group, 3-cyanopropyl group, etc. Examples include cyanoalkyl groups. In the present invention, an amino group-containing polysiloxane is synthesized by using the above-mentioned cyclic organopolysiloxane and aminodisiloxane and utilizing the equilibrium reaction of both compounds.The reaction between the cyclic organopolysiloxane and aminodisiloxane is The reaction is carried out in the presence of at least one basic catalyst selected from alkali metal oxides, hydroxides, alcoholates, aryl oxides and silanolates and a cyclic polyether. In this case, basic catalysts include, for example, alkali metal oxides such as sodium oxide and potassium oxide, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide, sodium methoxide, and sodium ethoxide. , alkali metal alkoxides such as potassium ethoxide, alkali metal aryloxides such as sodium phenoxide and potassium phenoxide, and alkali metal silanolate compounds such as potassium salt of methylsilane triol and potassium salt of phenylsilane triol. Although potassium hydroxide is particularly preferred in the present invention. These basic compounds are not limited to one type, and may be used as a mixture of two or more types. The amount of basic catalyst used is 0.001 to 0.1% based on the cyclic organopolysiloxane of formula ().
(wt%, the same applies hereinafter), particularly preferably in the range of 0.005 to 0.05%. In addition, as a cyclic polyether, the following general formula ()

Those indicated by [ ] can be used. Here, R is, for example, methylene, ethylene, propylene, 1,2-cyclohexylene, 1,2-
It is a group selected from unsubstituted or substituted divalent hydrocarbon groups such as phenylene, and n is an integer of 3 or more. Examples of such cyclic polyether include crown ether (journal of the
American Chemical Society Volume 89
(see pages 7017 to 7036), specifically benzo-15-crown-5, cyclohexyl-15-
Crown-5,2,3-Naphtho-15-Crown-
5,2,3-decalyl-15-crown-5,18-
Crown-6, dibenzo-18-crown-6, dicyclohexyl-18-crown-6, benzo-18
-crown-6, cyclohexyl-18-crown 6,2,3-naphtho-18-crown-6, dibenzo-21-crown-7, dicyclohexyl-21-
Crown-7, dibenzo-24-crown-8, dicyclohexyl-24-crown-8, di(2,3
-naphtho)-24-crown-8, dibenzo-30-
Crown-10, dicyclohexyl-30-crown-10, and the like. In the present invention, 18-crown-6, dicyclohexyl-18-crown-6, etc. are particularly preferred. Incidentally, such a cyclic polyether can be easily synthesized by the method described in the above-mentioned literature. Furthermore, the amount of cyclic polyether used is 0.003% based on the cyclic organopolysiloxane of formula ().
As mentioned above, it is particularly preferable that the amount is in the range of 0.005 to 0.05%, and if the amount used is less than 0.003%, the reaction cannot proceed at low temperature and in a short time, and the object of the present invention may not be achieved. In the production method of the present invention, the equilibration reaction between the cyclic organopolysiloxane of formula () and the aminoalkyldisiloxane of formula () is carried out by heating in the presence of the basic catalyst and cyclic polyether. , heating temperature is not particularly limited, but 80~
The temperature is preferably 180°C, particularly in the range of 140 to 160°C. Further, the reaction time can be set to 4 to 6 hours, which can significantly shorten the reaction time, which is usually about 40 hours in conventional methods. Furthermore, the above equilibration reaction may be carried out in an organic solvent. As the organic solvent, for example, toluene, xylene, etc. are preferably used. When carrying out the method of the present invention, for example, one or more mixtures of cyclic organopolysiloxanes of the formula () and one or more mixtures of aminoalkyldisiloxanes of the formula (2) are added to the above-mentioned The desired amino group-containing polysiloxane can be obtained by adding a basic catalyst and adding the cyclic polyether thereto while heating and stirring. After the equilibrium reaction is complete, neutralize and
The amino group-containing polysiloxane can be collected by stripping and filtering and removing generated salts. Effects of the Invention According to the production method of the present invention, an amino group-containing polysiloxane having a small molecular weight distribution and low viscosity can be efficiently synthesized at low temperature and in a short time. In this case, in the method of the present invention, the reaction proceeds completely even if the amount of basic catalyst added is less than half of the usual amount, and the reaction time is 4 to 6 hours, compared to about 40 hours in the conventional method.
In addition, due to the reduction in the amount of basic catalyst added, only a small amount of salt is generated during neutralization after the completion of the reaction, and the salt can be easily filtered and removed to easily obtain amino group-containing polysiloxane. I can do it. Therefore, the method of the present invention is industrially very advantageous as a method for producing amino group-containing polysiloxanes. EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. Example 1, Comparative Example 0.004 g of potassium hydroxide and 60.006 g of cyclohexyl-18-crown were added to 150 g of octamethylcyclotetrasiloxane and 2.5 g of 1,3-bis(3-aminopropyl)tetramethyldisiloxane. After stirring at 160° C. for 5 hours, an aminopropylpolysiloxane with an equilibrated viscosity of 411 cs was obtained (Example 1). For comparison, 0.008 g of potassium hydroxide was added without using cyclohexyl-18-crown-6, and the mixture was stirred at 140 to 160° C. for 42 hours to obtain an aminopolysiloxane (comparative example). Next, the molecular weight distributions of the above two types of aminopropyl polysiloxanes were measured using gel permeation chromatography. The results are as shown in Figure 1, and both were confirmed to be polymers with excellent molecular weight distribution. Furthermore, the above aminopropylpolysiloxanes were compared in terms of their neutralization, stripping, and transient properties. As a result, aminopropylpolysiloxane (Example 1) containing cyclohexyl-18-crown-6 produced less salt and could be easily filtered.
Aminopropyl polysiloxane to which cyclohexyl-18-crown-6 was not added (comparative example) caused paper clogging and had poor permeability. Examples 2 to 6 Aminopropyl polysiloxanes were produced in the same manner as in Example 1 with the compositions shown in Table 1, and the equilibration time and viscosity change at 150°C were measured. The results are shown in Figure 2.

【table】

[Table] From the results shown in Figure 2, if the amount of cyclohexyl-18-crown-6 added is 63 to 31.5 ppm and the amount of KOH added is about 0.025 g (122 ppm), the reaction time and cost will be significantly reduced. It turns out that it is possible. Example 7 Formula obtained by alkali cracking of hydrolysis product of dimethyldichlorosilane instead of octamethylcyclotetrasiloxane

When the treatment was carried out in the same manner as in Example 1 except that a cyclic dimethylpolysiloxane mixture represented by the formula was used, aminopropylpolysiloxanes having substantially the same viscosity were obtained.

[Brief explanation of the drawing]

Figure 1 is a graph showing the molecular weight distribution of the aminopropyl polysiloxanes of Example 1 and Comparative Example measured using GPC, and Figure 2 is a graph showing the molecular weight distribution of aminopropyl polysiloxanes of Example 1 and Comparative Example, which were obtained by changing the amount of cyclohexyl-18-crown-6 added. It is a graph showing equilibration time and viscosity change at 150°C of aminopropyl polysiloxane.

Claims (1)

[Scope of Claims] 1 The following general formula () [Chemical formula] (However, in the formula, R ¹ and R ² are each the same or different unsubstituted or substituted monovalent hydrocarbon groups,
l is an integer of 3 or more. ) Cyclic organopolysiloxane represented by the following general formula () [Chemical formula] (However, in the formula, R ³ and R ⁴ are each the same or different unsubstituted or substituted monovalent hydrocarbon groups,
m is an integer from 1 to 6. ) is heated in the presence of a cyclic polyether and at least one basic catalyst selected from alkali metal oxides, hydroxides, alcoholates, aryl oxides, and silanolates. A method for producing an amino group-containing polysiloxane, the method comprising: causing an equilibration reaction.