JPH0873741A - Method for removing residual platinum catalyst - Google Patents

Abstract

PURPOSE: To provide a method for the efficient removal of a residual platinum catalyst in an organosilicon compound. CONSTITUTION: A residual platinum catalyst in an organosilicon compound is removed by bringing a sulfur-containing silicon powder represented by formula (I) Ym Si(OR<1> )n O(4--m-n)/2 Y is a monovalent organic group containing one or more sulfur atoms, R<1> is-a 1-4 C alkyl group, and m and n are each a number that satisfies 0<m<1 and 0<m+n<2) into contact with a crude solution of the organosilicon compound synthesized by an addition reaction using the platinum catalyst.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for removing residual platinum catalyst in an organosilicon compound. More specifically, it relates to a method for efficiently and safely removing a platinum catalyst remaining in a solution containing an organosilicon compound synthesized by an addition reaction using a platinum catalyst.

[0002]

2. Description of the Related Art As a method for synthesizing an organosilicon compound,
A method called the hydrosilylation method by an addition reaction of Si-H-containing silanes or polysiloxanes with olefins or acetylenic unsaturated bond-containing compounds is known and widely used. Many catalysts that have been reported to be effective in promoting this reaction have been reported, but platinum compounds are generally used as catalysts.

However, if the platinum catalyst remains in the synthesized organic silicon compound solution after the above reaction, the platinum causes the organic silicon compound solution to turn black, resulting in a markedly poor appearance. In addition, if unreacted Si-H remains in the reaction solution, it is very dangerous because it is dehydrogenated by the dissolved platinum. Therefore, such residual platinum catalyst can be removed by various methods.

As a method of removing the residual platinum catalyst, there are a distillation method and a method of treating with activated carbon. In addition, Japanese Patent Publication Sho 53-8
662 discloses a method of removing a platinum catalyst by putting clay or diatomaceous earth to which thiol or thioether functional silicone is adhered in a silicone solution as a platinum removing agent, heating and stirring and then separating. .

[0005]

However, the conventional methods for removing the residual platinum catalyst as described above have various problems. The distillation method can be applied when the organosilicon compound to be synthesized is a low molecular weight organosilicon compound such as a monomer or dimer, but distillation is not possible when synthesizing a high molecular weight organosilicon compound such as silicone oil. And is not applicable.

The activated carbon treatment method can also be applied to high molecular weight organosilicon compounds, but the activated carbon treatment can sufficiently remove the color, but the residual platinum catalyst cannot be completely removed, and platinum of the order of several ppm is used. There is a problem that the catalyst remains and the storage stability is lowered depending on the product. Further, even if a large amount of activated carbon is used, there is no great difference in the treatment amount of the residual platinum catalyst, and conversely, the product itself is also adsorbed due to the size of the specific surface area, and the product loss increases. Furthermore, since the activated carbon itself has a poor filterability, there is a problem that clogging occurs or activated carbon is mixed into the product.

Further, in the method disclosed in Japanese Patent Publication No. 53-8662, only the platinum catalyst is attached to the surface of the platinum removing agent, so that the thiol or thioether can be removed while heating and stirring to remove the platinum catalyst. Functional silicones can liberate in silicone solutions and contaminate the product. In particular, if such thiol or thioether functional silicone remains, the product may have a sulfur odor, which may lower the product value. Further, when it is desired to carry out an addition reaction or a polymerization reaction after removing the platinum catalyst by the platinum removing agent, the residual thiol or thioether functional silicone becomes a catalyst poison of platinum or a polymerization terminator. However, there was a problem that the reaction did not proceed.

From this point of view, it is an object of the present invention to provide a method capable of efficiently adsorbing and removing the residual platinum catalyst in the organosilicon compound.

[0009]

Means for Solving the Problems As a result of intensive studies for achieving the above object, the present invention has revealed that the residual platinum catalyst can be efficiently removed by contacting a sulfur atom-containing silicon-based powder with a crude organic silicon compound solution. I found it.

That is, the present invention provides a compound represented by the general formula (I) Y _m Si (OR ¹ ) _n O _{(4-mn) / 2} (I) (wherein Y represents a monovalent organic group containing at least one sulfur atom). R ¹ represents an alkyl group having 1 to 4 carbon atoms, and m and n represent a number satisfying 0 <m <1 and 0 <m + n <2.). , A residual platinum catalyst in an organosilicon compound is removed by contacting it with a crude liquid of an organosilicon compound synthesized by an addition reaction using a platinum catalyst.

The sulfur atom-containing silicon-based powder represented by the general formula (I) is, for example, the general formula (II) YSi (OR ¹ ) ₃ (II) (wherein Y and R ¹ are the general formula (I)). in represents the same group as Y, and R ^1. and organoalkoxysilane represented by), the general formula ^{(III) Si (oR 1)} 4 (III) ( where, R ¹ is the general formula (I) and R ¹ in An organoalkoxysilane represented by
It is obtained by reacting in water or a water-containing organic solvent in the presence of a fluorine-containing silicon compound having a —F bond or a fluorine salt compound catalyst.

The present invention will be described in detail below.

The sulfur atom-containing silicon-based powder of the present invention is obtained, for example, by a reaction between an organoalkoxysilane having a sulfur atom-containing organic functional group and an organoalkoxysilane having no sulfur atom-containing organic functional group.

The organoalkoxysilane having a sulfur atom-containing organic functional group is represented by the general formula (II) YSi (OR ¹ ) ₃ (II) (wherein Y represents a monovalent organic group containing at least one sulfur atom). , R ¹ represents an alkyl group having 1 to 4 carbon atoms).

Y is 1 containing at least one sulfur atom
A valent organic group, that is, a monovalent hydrocarbon group which may have an oxygen atom, a nitrogen atom or a sulfur atom in its main chain or side chain,
The preferred carbon number is 1 to 12.

Examples of the organoalkoxysilane containing a sulfur atom-containing functional group include HS (CH ₂ ) ₃ Si (OCH ₃ ) ₃ HS (CH ₂ ) ₃ Si (OCH ₂ CH ₃ ) ₃ HS (CH ₂ ) _{6 Si (OCH 3) 3 HS (} CH 2) 6 Si (OCH 2 CH 3) 3 HS (CH 2) 8 Si (OCH 3) 3 HS (CH 2) 8 Si (OCH 2 CH 3) 3 HS (CH 2 ) ₁₀ Si (OCH ₃ ) ₃ HS (CH ₂ ) ₁₀ Si (OCH ₂ CH ₃ ) ₃ HSCH ₂ C ₆ H ₄ (CH ₂ ) ₂ Si (OCH ₃ ) ₃ HSCH ₂ C ₆ H ₄ (CH ₂ ) ₂ Si (OCH ₂ CH ₃ ) ₃

Embedded image

Embedded image

[Chemical 3]

[Chemical 4] _{CH 3 S (CH 2) 3} Si (OCH 3) 3 CH 3 S (CH 2) 3 Si (OCH 2 CH 3) 3 CH 3 CH 2 S (CH 2) 3 Si (OCH 3) 3 CH 3 CH 2 _{S (CH 2) 3 Si (} OCH 2 CH 3) 3 CH 3 CH 2 CH 2 S (CH 2) 3 Si (OCH 3) 3 CH 3 CH 2 CH 2 S (CH 2) 3 Si (OCH 2 CH 3 _{) 3 CH 3 = CHCH 2 S} (CH 2) 3 Si (OCH 3) 3 CH 3 = CHCH 2 S (CH 2) 3 Si (OCH 2 CH 3) 3 C 6 H 5 CH 2 S (CH 2) 3 _{Si (OCH 3) 3 C 6} H 5 CH 2 S (CH 2) 3 Si (OCH 2 CH 3) 3 S ((CH 2) 3 Si (OCH 3) 3) 2 S ((CH 2) 3 Si ( _{OCH 2 CH 3) 3) 2} S 4 ((CH 2) 3 Si (OCH 3) 3) 2 S 4 ((CH 2) 3 Si (OCH 2 CH 3) 3) 2 S 4 ((CH _{2 C 6 H 4 CH 2 CH} 2) Si (OCH 3) 3) 2 S 4 ((CH 2 C 6 H 4 CH 2 CH 2) Si (OCH 2 CH 3)
₃ ) ₂

[Chemical 5]

[Chemical 6] However, the present invention is not limited to these.

The organoalkoxysilane containing no sulfur atom-containing organic functional group used herein has the general formula (III) Si (OR ¹ ) ₄ (III) (wherein R ¹ is the same as in the general formula (I)). It represents the same group as R ^1. ).

Examples of the above-mentioned organoalkoxysilane include Si (OCH ₃ ) ₄ Si (OC ₂ H ₅ ) ₄ Si (OC ₃ H ₇ ) ₄ Si (OC ₄ H ₉ ) ₄

[Chemical 7] Are exemplified.

The mixing ratio of these two types of organoalkoxysilane is such that the organoalkoxysilane containing a sulfur atom-containing organic functional group and the organoalkoxysilane not containing a sulfur atom-containing organic functional group are so that the target product is solid. The molar ratio of is preferably 3.0 or less. The range of 0.01 to 3.0 mols is particularly preferable, and the range of 0.1 to 2.0 mols is particularly preferable.
If this molar ratio exceeds 3.0, the properties of the obtained target product may become liquid or oil. Also,
If this molar ratio is less than 0.01, the functionality of the sulfur atom may not be exhibited. In addition, a small amount of monoalkoxysilane and / or dialkoxysilane may be contained within the range where the target product becomes a solid.

A mixture of these two types of organoalkoxysilanes
The compound contains at least one Si-F bond in the molecule.
Fluorine-containing silicon compound or fluoride salt compound
Used as a reaction. As a fluorine-containing silicon compound
For example, FSi (OCH 3)₃, FSi (OCH₂C
H₃), (NH_Four)₂SiF₆Are exemplified. Also,
Examples of fluoride compounds include NaF, KF, (CH₃
CH₂CH₂CH₂)_FourN · F and the like are exemplified. These touches
The amount of the medium is determined by the sulfur atom-containing trialkoxysilane and the
Alkoxysilane used for hydrolysis of traalkoxysilane
The molar ratio of Si to F in the sum of orchis is 1.0 to 0.00.
It is preferably used in the range of 01 to 1.0 to 2.0.
It

This organoalkoxysilane mixture is
By carrying out a hydrolysis-polycondensation reaction using the above catalyst, the sulfur atom-containing silicon-based powder used in the present invention can be obtained.

Next, the method for removing the residual platinum catalyst from the organic silicon compound crude solution using this sulfur atom-containing silicon-based powder will be described in detail. First, a method for batch processing will be described. Almost no platinum catalyst is contained by removing the sulfur atom-containing silicon powder by filtration after adding the sulfur atom-containing silicon powder to the organic silicon compound crude solution after the reaction with the platinum catalyst and performing contact treatment. An organosilicon compound can be obtained.

At this time, the amount of the sulfur atom-containing silicon-based powder added is 5: 1 to the mole number of sulfur atoms in the sulfur atom-containing silicon powder to the mole number of platinum atoms in the organosilicon compound.
It is adjusted to a ratio of 500: 1, more preferably 30: 1 to 300: 1.

The platinum removal treatment can be carried out usually at ambient temperature, that is, at about 15-25 ° C. However, the treatment is possible even at high temperature. The contact treatment time may be 2 to 48 hours.

The organosilicon compound to be treated may be 100% of the organosilicon compound or may be dissolved in an alcohol such as methanol or ethanol or a hydrocarbon solvent such as toluene. In the case of a high molecular weight organosilicon compound, it can be more efficiently processed by dissolving it in a solvent. After the contact treatment, the sulfur atom-containing silicon-based powder is removed from the system by a method such as filtration to obtain an organosilicon compound containing almost no platinum catalyst.

The removal of the platinum catalyst by the continuous method is accomplished by filling a suitable packed column with the sulfur atom-containing silicon-based powder, and passing and contacting the platinum catalyst-containing organosilicon compound crude solution therein. At this time, the number of moles of the total sulfur atoms of the sulfur atom-containing silicon-based powder packed in the packed column and the number of moles of platinum atoms in the organic silicon compound crude solution to be treated are 5: 1 to 500: 1, and more preferably 30 to 1 to 300
It is possible to treat the crude organosilicon compound solution to a ratio of 1: 1.

This process is carried out at a normal ambient temperature, that is, about 1
It can be performed at 5 to 25 ° C. Contact treatment time is 2-4
It suffices to carry out the passage processing within a range of 8 hours.

The organosilicon compound to be treated can be either an organosilicon compound of 100% or one dissolved in an alcohol such as methanol or ethanol or a hydrocarbon solvent such as toluene. By the passing contact treatment, an organosilicon compound containing almost no platinum can be obtained.

[0029]

EXAMPLES Examples of the present invention will be described in detail below.

[Production Example of Sulfur Atom-Containing Silicon Powder] K
F. 1.16 g (0.02 mol), water 1550 g (86.
1 mol) was placed in a 2 liter reactor equipped with a stirrer, a thermometer and a condenser, and mixed by stirring. Then, a mixture of 196 g (1.0 mol) of mercaptopropyltrimethoxysilane and 152 g (1.0 mol) of tetramethoxysilane was added dropwise at room temperature over 3 minutes, and after completion of the addition, 2 minutes at room temperature. Upon stirring, the colorless and transparent reaction liquid changed to a white gel. After stirring at room temperature for 1 hour, the mixture was filtered with a pressure filter, washed with distilled water and then with acetone, and dried at 100 ° C. and 5 mmHg by using a vacuum dryer.
After treatment for 2 hours to remove the solvent, 180 g of a mercaptopropyl group-containing silicon-based powder was obtained with a yield of 96%. The sulfur content in this mercaptopropyl group-containing silicon-based powder was 16.8 wt% by elemental analysis.

The yield and sulfur content of the sulfur-containing silicon-based powder synthesized by using 1.0 mol of trialkoxysilane shown in Table 1 instead of mercaptopropyltrimethoxysilane in the above reaction are also shown in Table 1. Indicate.

[0032]

[Table 1]

[Example 1]

Embedded image Methylhydrogen polysiloxane represented by 1.0
00g,

[Chemical 9] Polyoxyalkylene allyl ether acetic ester 1.48 represented by (m / n = 50/50, m, n≈20)
7 g was subjected to an addition reaction with a chloroplatinic acid (alcohol solution) catalyst (containing 50 ppm as the amount of platinum) in a toluene solvent. The resulting silicone solution was prepared into a 50% toluene solution. The amount of residual platinum was measured and found to be 30 ppm, and the appearance was a blackish brown solution.
The reaction product is

[Chemical 10]

To 50 g of this crude silicone solution was added 0.05 g of the above mercaptopropyl group-containing silicon-based powder, and the mixture was stirred at room temperature for 3 hours. After that, the treatment liquid was filtered with a filter paper, but there was no problem in filterability. The obtained filtrate was a colorless transparent solution. When the amount of residual platinum was measured, it was 0.1 ppm or less. The sulfur content was also measured and found to be 0.1 ppm or less.

[Examples 2 to 7] In place of the mercaptopropyl group-containing silicon-based powder of Example 1, a to a shown in Table 1 were used.
Table 2 shows the results of similar treatment using the silicon-based powder of e.

[Table 2]

[Comparative Example 1] The same treatment was carried out except that 0.05 g of activated carbon was used in place of the mercaptopropyl group-containing silicon-based powder of Example 1. After the treatment, filtration was carried out with a piece of filter paper, and a small amount of activated carbon was mixed in the filtrate. Next, when two filter papers were stacked, the activated carbon could not pass through, but the filterability deteriorated. The filtrate obtained was thinner than the original silicone solution, but was still colored brown. Moreover, as a result of measuring the amount of residual platinum, 12 ppm
It remained.

Comparative Example 2 W having a grain size of about 0.6 μm
10 g of herver Hubers clay
₂ ) Add 0.2 g of ₃ Si (OMe) ₃ and 100 ℃ for 2 hours
A platinum removing agent was prepared by stirring with. The same treatment was carried out except that this platinum removing agent was used in place of the mercaptopropyl group-containing silicon-based powder of Example 1. As a result of measuring the amount of residual platinum in the treatment liquid, 2 ppm remained. Further, when the sulfur content was measured, it was found to be 32 ppm dissolved.

[Example 8] 11.6 g of a mercaptopropyl group-containing silicon powder containing 16.8 wt% of sulfur atoms synthesized in the production example of a sulfur atom-containing silicon powder in a glass tube having an inner diameter of 2 cm and a length of 30 cm. Filled. Next, 15 kg of the platinum catalyst-containing silicone crude solution (platinum content 30 ppm) prepared in Example 1 was passed over the silicon-based powder for 10 hours. The appearance of the silicone solution flowing out from the glass tube was a colorless transparent solution, and the result of measuring the amount of residual platinum was 0.1 ppm or less. The sulfur content was also measured and found to be 0.1 ppm or less.

[0039]

As described above, the present invention has the following advantages. (1) Treated with a silicon-based powder having a sulfur atom-containing organic functional group and capturing the platinum catalyst by chemical adsorption instead of physical adsorption like activated carbon (Pt-S coordination), so almost completely platinum catalyst Can be removed. (2) Workability, particularly filterability, is better than that of activated carbon treatment, and problems such as clogging and mixing do not occur. (3) Since the sulfur atom-containing silicon-based powder used as the platinum removing agent has a smaller specific surface area than activated carbon, the product loss is small even when used in a large amount. (4) Since the sulfur atom-containing silicon-based powder used as the platinum removing agent is synthesized by the sol-gel method, the sulfur component is not released into the organosilicon compound and the product is not contaminated. Due to the above advantages, the present invention achieves high quality and safe storage of organosilicon compounds.

Claims (2)

[Claims] 1. General formula (I) Y _m Si (OR ¹ ) _n O _{(4-mn) / 2} (I) (wherein Y represents a monovalent organic group containing at least one sulfur atom, and R ¹ represents an alkyl group having 1 to 4 carbon atoms, and m and n represent a number satisfying 0 <m <1 and 0 <m + n <2. A method for removing a residual platinum catalyst, which comprises removing a residual platinum catalyst in an organosilicon compound by bringing it into contact with a crude liquid of an organosilicon compound synthesized by an addition reaction using 2. The sulfur atom-containing silicon-based powder represented by the general formula (I) has the general formula (II) YSi (OR ¹ ) ₃ (II) (wherein Y and R ¹ are the general formula (I)). in represents the same group as Y, and R ^1. and organoalkoxysilane represented by), the general formula ^{(III) Si (oR 1)} 4 (III) ( where, R ¹ is the general formula (I) and R ¹ in An organoalkoxysilane represented by
The method for removing a residual platinum catalyst according to claim 1, which is obtained by reacting in a water or a water-containing organic solvent in the presence of a fluorine-containing silicon compound having a -F bond or a fluorine salt compound catalyst.