JPH09316109A - Polymerization inhibitor for vinylphenyl-groupcontaining silane compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to synthesize a vinylphenyl-groupcontaining silane compound and to purify it by distillation by heating on an industrial scale and also to prevent the vinylphenyl-groupcontaining silane compound from being spontaneously polymerized during its storage by using a specified compound as a polymerization inhibitor for the vinylphenyl- group-containing silane compound. SOLUTION: As a polymerization inhibitor for a vinylphenyl-groupcontaining silane compound denoted by formula II wherein R<2> denotes a halogen atom or an alkoxy group having 8 or less carbon atoms; R<3> denotes an alkyl group having 8 or less carbon atoms; and n is 1 to 3, an active ingredient, i.e., a compound denoted by formula I wherein R<1> denotes a hydroxy group or a dimethylamino group is used in an amount of 1ppm to 10% by weight based on the compound represented by formula II. If necessary, a conventionally known other polymerization inhibitor is additionally used. The polymerization inhibitor is added at the time of synthesis of a vinylphenyl-group-containing silane compound, or to a crude product of a vinylphenyl-group-containing silane compound before the distillation, or to a vinylphenyl-group-containing silane compound during its storage so as to inhibit the polymerization of the vinylphenyl-groupcontaining silane compound. The compound of formula II is a compound useful as a silane coupling agent, a polymerizable monomer, a resin modifying agent raw material, etc.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an industry of a vinylphenyl group-containing silane compound represented by the following general formula (2), which is industrially useful as a silane coupling agent, a polymerizable monomer, a raw material for a resin modifier, and the like. TECHNICAL FIELD The present invention relates to a polymerization inhibitor for vinylphenyl group-containing silane compounds, which can sufficiently prevent spontaneous polymerization reaction during heating distillation for the purpose of synthesis and isolation / purification on a physical scale, and during storage.

[0002]

Embedded image (However, in the formula, R ² is a halogen atom or an alkoxy group having 8 or less carbon atoms, R ³ is an alkyl group having 8 or less carbon atoms,
n is an integer of 1 to 3. )

[0003]

2. Description of the Related Art A vinylphenyl group-containing silane compound, particularly a vinylphenyl group-containing silane compound represented by the general formula (2), has a self-polymerizable vinylphenyl group in its structure. Silane coupling agent, due to its unique properties,
It is a substance that is industrially useful as a polymerizable monomer and a raw material for resin modifiers.

However, since the vinylphenyl group-containing silane compound of the above formula (2) has a self-polymerizable vinylphenyl group, it is heated by distillation for the purpose of synthesis and isolation purification on an industrial scale. Moreover, it is very prone to self-polymerization during storage, which can cause many problems. For example, when synthesizing on an industrial scale and attempting to purify it by heating distillation, the polymerization reaction spontaneously occurs due to the heat of the process, and gelation occurs in the reaction device or distillation pot, or gelation occurs in the piping of the distillation device. It becomes solid and becomes clogged, which causes a great damage to the manufacturing process. In addition, the polymerization reaction is likely to occur spontaneously even during storage. Therefore, establishment of a spontaneous polymerization reaction prevention technique for the polymerizable compound of the above formula (2) facilitates production on an industrial scale. It is extremely important to do so, and is especially urgent.

As a technique for preventing the spontaneous polymerization reaction of the vinylphenyl group-containing silane compound, for example, a technique of blowing an appropriate amount of molecular oxygen is generally known, and US Pat. 982,757, di-tert-butylhydroquinone, hydroquinone, resorcinol, N, N'-di-β-naphthyl-
P-phenylenediamine, N-β-naphthyl-N-phenylamine and the like have been proposed as polymerization inhibitors. Further, as a polymerization inhibitor, German Patent No. 1,157,6
In No. 13, 2,4-dinitrophenol was added to the chemical abstract CA89: 1010993s (197).
7) describes picric acid, and is disclosed in JP-A-4-12419.
No. 1 discloses BHT (4-methyl-2,6-di-te.
rt-butylphenol), benzoquinone, p-ter
t-butylcatechol, dinitrobenzene, tri-p-
Nitrophenylmethyl, DPPH (1,1-diphenyl-2-picrylhydrazyl), etc., JP-A-4-24388
No. 5, gazette discloses 2,6-di-tert-butylphenol, phenothiazine, copper dimethyldithiocarbamate,
2,5-di-tert-butylhydroquinone, 2,
2'-methylene-bis (6-tert-butyl-4-ethylphenol) and the like are described.

However, these polymerization inhibitors cannot sufficiently prevent the polymerization reaction in the distillation pot which is in a high temperature state for a long time in an industrial scale distillation process, or have an explosion risk. Moreover, there were various problems such as high toxicity, and none of them could withstand satisfactory use. As described above, a polymerization inhibitor having sufficient performance for producing a vinylphenyl group-containing silane compound on an industrial scale has not yet been found.

The present invention has been made in view of the above circumstances and has been proposed for the purpose of synthesizing and isolating and refining the vinylphenyl group-containing silane compound of the above formula (2) on an industrial scale, and further during storage during storage. It is an object of the present invention to provide a polymerization inhibitor for vinylphenyl group-containing silane compounds that can sufficiently prevent spontaneous polymerization reaction.

[0008]

Means for Solving the Problems and Modes for Carrying Out the Invention As a result of extensive studies conducted by the present inventor to achieve the above object, the synthesis of a vinylphenyl group-containing silane compound represented by the following general formula (2): Heating distillation for isolation and purification,
Furthermore, by using a compound represented by the following general formula (1) as a polymerization inhibitor as an active ingredient during storage, surprisingly, compared to conventionally known polymerization inhibitors, vinylphenyl group-containing silane compounds are used. It has been found that it has a remarkable and surprising effect of inhibiting polymerization, can suppress the occurrence of problems such as lowering of yield due to thickening and gelation and deterioration of productivity, and has no problems of explosion risk and toxicity. That is, the compound of the following formula (1) is a known polymerization inhibitor such as BHT (4-methyl-2,6-di-tert-butylphenol) or 4
-Ethyl-2,6-di-tert-butylphenol is surprisingly different in comparison with its polymerization inhibiting effect, and has an excellent polymerization inhibiting effect that cannot be simply inferred from similar skeletons. Is found.

[0009]

Embedded image (However, in the formula, R ¹ is a hydroxy group or a dimethylamino group.)

[0010]

Embedded image (However, in the formula, R ² is a halogen atom or an alkoxy group having 8 or less carbon atoms, R ³ is an alkyl group having 8 or less carbon atoms,
n is an integer of 1 to 3. )

Furthermore, when the present inventors used the compound of the above formula (1) in combination with one or more other conventionally known polymerization inhibitors, they were unexpectedly far superior. The present inventors have found that they exhibit a synergistic stabilizing effect and have completed the present invention.

Accordingly, the present invention is characterized by containing the compound represented by the above formula (1) or the compound of the above formula (1) and another polymerization inhibitor as an active ingredient. A polymerization inhibitor for a vinylphenyl group-containing silane compound represented by 2) is provided.

The present invention will be described in more detail below. The polymerization inhibitor of the present invention contains a compound represented by the following general formula (1) as an active ingredient.

[0014]

[Chemical 6] (However, in the formula, R ¹ is a hydroxy group or a dimethylamino group.)

Specifically, 4-hydroxymethyl-2,
6-di-tert-butylphenol and 4-dimethylaminomethyl-2,6-di-tert-butylphenol are used alone or in combination. In addition, these compounds can be easily obtained industrially.

The vinylphenyl group-containing silane compound for which a polymerization inhibitor containing the compound of the above formula (1) as an active ingredient is used is represented by the following general formula (2). Can be added to the reaction system of the vinylphenyl group-containing silane compound of formula (2),
The object can be achieved by adding it at the time of synthesizing the vinylphenyl group-containing silane compound, adding it to the crude product of the vinylphenyl group-containing silane compound before distillation, or adding it at the time of storage.

[0017]

[Chemical 7] (However, in the formula, R ² is a halogen atom or an alkoxy group having 8 or less carbon atoms, R ³ is an alkyl group having 8 or less carbon atoms,
n is an integer of 1 to 3. )

In the above formula (2), R ² is a halogen atom or an alkoxy group having 8 or less carbon atoms, and examples thereof include a chlorine atom, a bromine atom, a fluorine atom, a methoxy group, an ethoxy group, a propoxy group and a butoxy group. In particular, chlorine atom, methoxy group and ethoxy group are preferable. Also, R ³
Is an alkyl group having 8 or less carbon atoms, such as a methyl group,
Examples thereof include an ethyl group, a propyl group and a butyl group, and a methyl group is particularly preferable. n is an integer of 1 to 3.

In the compound of the above formula (2), the vinyl group in the molecule may be in the ortho, para or meta position with respect to the silicon atom.

Specific examples of the vinylphenyl group-containing silane compound represented by the above formula (2) include the following. 4-vinylphenyltrimethoxysilane 4-vinylphenylmethyldimethoxysilane 4-vinylphenyldimethylmethoxysilane 4-vinylphenyltriethoxysilane 4-vinylphenylmethyldiethoxysilane 4-vinylphenyldimethylethoxysilane 4-vinylphenyltrichlorosilane 4 -Vinylphenylmethyldichlorosilane 4-vinylphenyldimethylchlorosilane 3-vinylphenyltrimethoxysilane 3-vinylphenylmethyldimethoxysilane 3-vinylphenyldimethylmethoxysilane 3-vinylphenyltriethoxysilane 3-vinylphenylmethyldiethoxysilane 3- Vinylphenyldimethylethoxysilane 3-vinylphenyltrichlorosilane 3-vinylphenylmethyldichlorosilane 3-vinyl Phenyldimethylchlorosilane 2-vinylphenyltrimethoxysilane 2-vinylphenylmethyldimethoxysilane 2-vinylphenyldimethylmethoxysilane 2-vinylphenyltriethoxysilane 2-vinylphenylmethyldiethoxysilane 2-vinylphenyldimethylethoxysilane 2-vinylphenyl Trichlorosilane 2-vinylphenylmethyldichlorosilane 2-vinylphenyldimethylchlorosilane

As a method for producing these vinylphenyl group-containing silane compounds, many methods have been known so far,
Generally, it can be obtained by a method of coupling a Grignard reagent such as vinylphenyl magnesium halide with a corresponding silane compound.

The amount of the compound of the above formula (1) used is not particularly limited, but it is 1 ppm to 10% by weight, particularly 1
The range of 0 ppm to 1% is preferable.

The polymerization inhibitor of the present invention contains the compound of formula (1) as an active ingredient as described above. In this case, the compound of formula (1) may be combined with another conventionally known polymerization inhibitor. It can be used in combination and can be used in combination with the compound of the above formula (1) and one of the active ingredients of other polymerization inhibitors conventionally known as polymerization inhibitors.
When used in combination with two or more species, a synergistic stabilizing effect that is unexpected and far superior is exhibited. Examples of compounds known as active ingredients of other polymerization inhibitors include, for example, hydroquinone, hydroquinone monomethyl ether, N, N′-di-β-naphthyl-p-phenylenediamine, N-β-naphthyl-N-phenylamine. , BHT, benzoquinone, 2,6-di-tert-butylphenol, phenothiazine, copper dimethyldithiocarbamate, 2,5-di-tert-butylphenol, phenothiazine, 2,5-di-tert-butylhydroquinone, 2,2'- Methylene-bis (6-ter
t-butyl-4-ethylphenol), 4-ethyl-
2,6-di-tert-butylphenol and the like can be mentioned.

The amount of the above-mentioned other active ingredients used is 1 pp by weight based on the vinylphenyl group-containing silane compound.
It is preferable that the content of m is 10%, especially 10 ppm to 1%. The method of use is the same as in the case of the compound of the above formula (1).

[0025]

INDUSTRIAL APPLICABILITY The polymerization inhibitor for vinylphenyl group-containing silane compounds of the present invention is heated for the purpose of synthesis and isolation purification of the vinylphenyl group-containing silane compound of the formula (2) on an industrial scale, and further stored. It is effective in sufficiently preventing spontaneous polymerization reaction at times. Therefore, the vinyl phenyl group-containing silane compound can be efficiently produced on an industrial scale by using the polymerization inhibitor of the present invention.

[0026]

EXAMPLES The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

Example 1 10 g of 4-vinylphenyldimethylchlorosilane and 4-hydroxymethyl-2,6-di-tert-butylphenol 0 obtained according to a conventionally known synthesis method were placed in a screw cap test tube which had been sufficiently replaced with nitrogen. ．
After charging 03 g (3000 ppm), the atmosphere was replaced with nitrogen again and sealed. Next, this test tube was immersed in an oil bath at 130 ° C., and changes in fluidity were checked over time. As a result, the initial fluidity was maintained without being impaired even after 40 hours, and 4-hydroxymethyl-2,6-di-tert-butylphenol was compared with the above vinylphenyl group-containing silane compound. It was confirmed that it has a very good polymerization inhibiting effect.

Example 2 4-hydroxymethyl-2,
The amount of 6-di-tert-butylphenol added was 0.0.
When the same test as in Example 1 was conducted except that the amount was 1 g (1000 ppm), the initial fluidity was maintained without being impaired even after 30 hours.

[Comparative Example 1] 4-hydroxymethyl-2,
When the same test as in Example 1 was carried out except that 6-di-tert-butylphenol was not added, 4-vinylphenyldimethylchlorosilane completely gelled after 1 hour. It was confirmed that without a polymerization inhibitor, the vinylphenyl group-containing silane compound has an unstable property that it is extremely susceptible to self-polymerization at high temperatures.

[Comparative Examples 2 to 12] Example 1 except that a conventionally known polymerization inhibitor shown in Table 1 was added instead of 4-hydroxymethyl-2,6-di-tert-butylphenol.
The same test was performed. The results are shown in Table 1, and it was found that all of the conventionally known polymerization inhibitors have an insufficient polymerization inhibiting effect.

Further, Comparative Example 11 has the following formula (1):
R ¹ is a compound of H (BHT), and Comparative Example 12 is a compound of formula (1) in which R ¹ is CH ₃ (4-ethyl-2,6-).
Di-tert-butylphenol), even though it has a chemical structure similar to that of 4-hydroxymethyl-2,6-di-tert-butylphenol of the present invention, due to the difference in the 4-position substituent, It was confirmed that the polymerization inhibition effect was significantly low.

[0032]

[Table 1]

Example 3 10 g of 4-vinylphenyltrimethoxysilane and 4-dimethylaminomethyl-2,6-di-tert-obtained according to a conventionally known synthesis method were placed in a screw cap test tube which had been sufficiently replaced with nitrogen. After charging 0.03 g (3000 ppm) of butylphenol, it was replaced with nitrogen again and sealed. Next, this test tube was immersed in an oil bath at 130 ° C., and changes in fluidity were checked over time. As a result, the initial fluidity was maintained even after 10 hours.

[Comparative Example 13] The same test as in Example 3 was conducted except that BHT was added instead of 4-dimethylaminomethyl-2,6-di-tert-butylphenol. It has turned into.

Comparative Example 14 The same test as in Example 3 was conducted except that 2,5-di-tert-butylhydroquinone was added instead of 4-dimethylaminomethyl-2,6-di-tert-butylphenol. Apparently, it gelled completely after 1 hour.

Example 4 10 g of 4-vinylphenyldimethylmethoxysilane and 4-dimethylaminomethyl-2,6-di-tert-obtained according to a conventionally known synthesis method were placed in a screw cap test tube which had been sufficiently replaced with nitrogen. After charging 0.03 g (3000 ppm) of butylphenol, it was replaced with nitrogen again and sealed. Next, this test tube was immersed in an oil bath at 130 ° C., and changes in fluidity were checked over time. As a result, the initial fluidity was maintained even after 10 hours.

Example 5 4-dimethylaminomethyl-
The same test as in Example 4 was carried out except that the addition amount of 2,6-di-tert-butylphenol was changed to 0.07 g (7000 ppm), but the fluidity was maintained even after 21 hours.

Example 6 4-dimethylaminomethyl-
The same test as in Example 4 was carried out except that the addition amount of 2,6-di-tert-butylphenol was changed to 0.1 g (10000 ppm), but the fluidity was maintained even after 30 hours.

Comparative Example 15 The same test as in Example 4 was carried out except that 4-dimethylaminomethyl-2,6-di-tert-butylphenol was not added, and 4-vinylphenyldimethylmethoxysilane was used for 1 hour. It later gelled completely.

[Comparative Examples 16 to 32] The same test as in Example 1 was carried out except that the following conventionally known polymerization inhibitors were added instead of 4-dimethylaminomethyl-2,6-di-tert-butylphenol. It was The results are shown in Table 2, and all of the conventionally known polymerization inhibitors had an insufficient polymerization inhibition effect.

[0041]

[Table 2]

Example 7 10 g of 3-vinylphenyltrimethoxysilane and 4-dimethylaminomethyl-2,6-di-tert-obtained according to a conventionally known synthesis method were placed in a screw cap test tube which had been sufficiently replaced with nitrogen. After charging 0.03 g (3000 ppm) of butylphenol, it was replaced with nitrogen again and sealed. Next, this test tube was immersed in an oil bath at 130 ° C., and changes in fluidity were checked over time. As a result, the fluidity was maintained even after 30 hours.

Comparative Example 33 The same test as in Example 4 was carried out except that 4-dimethylaminomethyl-2,6-di-tert-butylphenol was not added, and 3-vinylphenyltrimethoxysilane was tested for 4 hours. It later gelled completely.

Example 8 4-Vinylphenyldimethylmethoxysilane 50 obtained by a conventionally known synthesis method
4-dimethylaminomethyl-2,6-di-ter in 0 g
When 2.5 g (5000 ppm) of t-butylphenol was added and distilled under reduced pressure, a purified target product could be obtained with a distillation recovery rate of 87%.

[Comparative Example 34] The same test as in Example 8 was carried out except that 4-dimethylaminomethyl-2,6-di-tert-butylphenol was not added. It has turned into a gel.

Example 9 4-Vinylphenyldimethylmethoxysilane 50 obtained by a conventionally known synthesis method
4-dimethylaminomethyl-2,6-di-ter in 0 g
2.5 g (5000 ppm) of t-butylphenol and 1.5 g of copper dimethyldithiocarbamate (3000 pp)
When m) was added and distilled under reduced pressure, the distillation recovery rate was 91%.
As a result, the target substance purified in (3) was obtained.

Example 10 4-Vinylphenyldimethylchlorosilane 5 obtained by a conventionally known synthesis method
4-hydroxymethyl-2,6-di-tert in 00 g
-Butylphenol 2.5g (5000ppm) and hydroquinone monomethyl ether 0.25g (500p
pm) was added and distilled under reduced pressure to obtain a distillation recovery rate of 90.
It was possible to obtain the desired product purified in%.

[Comparative Example 35] 4-hydroxymethyl-
When the same test as in Example 10 was conducted except that 2,6-di-tert-butylphenol was not added, the contents of the still pot were completely gelated during the main distillate outflow.

[Example 11] 4-vinylphenyldimethylchlorosilane 5 obtained by a conventionally known synthesis method
4-hydroxymethyl-2,6-di-tert in 00 g
-Butylphenol 2.5 g (5000 ppm) and copper dimethyldithiocarbamate 1.5 g (3000 pp
m) was added and distilled under reduced pressure, the distillation recovery rate was 95%.
As a result, the target substance purified in (3) was obtained.

Claims (2)

[Claims] 1. The following general formula (1): (Wherein, R ¹ is a hydroxy group or a dimethylamino group), and a compound represented by the following general formula (2): (However, in the formula, R ² is a halogen atom or an alkoxy group having 8 or less carbon atoms, R ³ is an alkyl group having 8 or less carbon atoms,
n is an integer of 1 to 3. ) A polymerization inhibitor for a vinylphenyl group-containing silane compound represented by the formula (4). 2. The polymerization inhibitor according to claim 1, wherein a polymerization inhibitor other than the compound represented by the general formula (1) is added.