JP2947169B2 - Acrylic silane distillation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a chlorosilane or acetoxysilane having a methacryloxy group or an acryloxy group (hereinafter referred to as "acrylsilane").
More specifically, the present invention relates to a distillation method for effectively suppressing the spontaneous polymerization of acrylsilane generated during distillation purification on an industrial scale.

[0002]

2. Description of the Related Art Acrylic silane is a silane coupling agent, a raw material of a silane coupling agent, a raw material of a polysiloxane, a terminating agent in the production of polysiloxane, a surface treatment agent for various base materials, a modified material of various resins, and the like. Effective for a wide range of applications. Generally, such highly useful acrylic silane is obtained by performing a hydrosilylation reaction between an acrylate or methacrylate having an unsaturated site and a hydrosilane compound in the presence of a transition metal catalyst such as platinum, and further reacting the reaction solution. By distillation under reduced pressure.

[0003] Such a production example is disclosed in Japanese Patent Publication No. 6-51707.
The publication also discloses that after reacting allyl methacrylate and methyldichlorosilane in the presence of a platinum catalyst, distillation is performed under reduced pressure to produce 3-methacryloxypropyldimethylchlorosilane. A method is described.

[0004] However, acrylic silane can be used as a raw material for producing various functional materials due to its high polymerizability. However, acrylic silane can be used in the synthesis reaction process, distillation purification process, storage process and transport process of acrylic silane. However, it has a drawback that it is easily thermally spontaneously polymerized. For this reason,
In the step of synthesizing acrylic silane and in the step of purifying by distillation after the synthetic reaction, when heating to room temperature or higher is inevitable, it is most important how to prevent spontaneous polymerization of acryl silane. Usually, in order to prevent such spontaneous polymerization of acrylic silane, a polymerization inhibitor is added to a raw material or a reaction liquid of acrylic silane (hereinafter, referred to as an acrylic silane solution), and a phenol-based compound such as hydroquinone or methoquinone is used. Of the polymerization inhibitors are preferably used.

[0005] However, the phenol polymerization inhibitor causes a condensation reaction with acrylic silane (hereinafter, referred to as chlorosilane) in which a chlorine atom is bonded to a silicon atom,
It has the disadvantage that the ability to inhibit polymerization is lost. This is described in Japanese Patent Publication No. Hei 6-51707 and a paper by Efimov et al. (Zh. Obsch. Khim. (1991) 61 (10) 2244).
-53).

Usually, when selecting a polymerization inhibitor to be used, the performance of the polymerization inhibitor is determined by adding a methacrylate or an acrylate when the ester is heated to a temperature at which spontaneous polymerization occurs. The determination is made by examining how much the spontaneous polymerization of the ester is suppressed by the polymerization inhibitor. Usually, such a test is carried out by a beaker scale table test, and based on the results of this method, hindered phenols represented by 2,6-di-t-butyl-4-methylphenol, N, N It is known that amines represented by '-diphenyl-p-phenylenediamine or phenothiazine are extremely effective as polymerization inhibitors for acrylic silane. However, although the hindered phenols and the amines are effective in the table test, they have a drawback that when scaled up to an industrial scale, the spontaneous polymerization of acrylsilane cannot be sufficiently suppressed. .

The present inventors have conducted intensive studies on the above problems, and as a result, have found that there are two types of spontaneous polymerization of acrylsilane, homogeneous polymerization and multiplication polymerization. Homogeneous polymerization is a process in which the viscosity of a solution gradually increases with the polymerization of acrylic silane and solidifies in a purine-like manner.On the other hand, proliferation polymerization is an abnormal reaction in free radical polymerization and forms a popcorn-like shape in a solution. Insoluble polymer is produced, which has a form that gradually grows and expands. When acrylic silane undergoes multiplication, the volume of the polymer becomes more than twice the volume of the monomer.
It leads to serious accidents such as destruction of equipment.

[0008] Although the reason is not clear, in the table test, the dependence of uniform polymerization is extremely high, and propagation polymerization is hardly observed. As described above, even if the performance of the polymerization inhibitor is examined in the table test, it is only possible to grasp the effect on the uniform polymerization, and even if the scale-up is performed based on the result, the proliferation polymerization is suppressed. You can't. Therefore, when scaling up to an industrial scale, it is necessary to establish a polymerization inhibitor capable of preventing both homogeneous polymerization and propagation polymerization, and a production method using the inhibitor.

[0009] The apparatus generally used for distillation and purification is composed of a distillation still for heating and decompressing the acrylsilane solution obtained in the synthesis reaction step to vaporize it, and a distillation column for distilling the vaporized acrylsilane. Therefore, blending the polymerization inhibitor in the distillation still may be effective in suppressing the spontaneous polymerization of the acrylic silane solution in the distillation still, but it may be effective in suppressing the acrylic silane vapor passing through the inside of the distillation column. There is no effect of suppressing spontaneous polymerization of droplets (hereinafter, referred to as acrylic silane vapor). This is because the polymerization inhibitor added to the acrylic silane solution is not vaporized in the still, so that no polymerization inhibitor exists inside the distillation column.

As a method of suppressing spontaneous polymerization in the distillation column, there is a method of using a polymerization inhibitor having a boiling point equal to or slightly lower than that of acrylic silane. However, this method has a disadvantage that a large amount of a polymerization inhibitor is mixed into the product after distillation, thereby deteriorating the quality of the product, and a disadvantage that the type of the polymerization inhibitor must be appropriately selected according to the boiling point of the acrylic silane. Had. Although there is a method using oxygen or laughing gas, spontaneous polymerization cannot be sufficiently prevented by oxygen or laughing gas alone.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for distilling acrylsilane, which can solve the above-mentioned drawbacks of the prior art and can effectively suppress spontaneous polymerization of acrylsilane during distillation purification. It is in.

[0012]

The present invention has the following configurations (1) to (4). (1) When purifying the acrylsilane represented by the formula (I) by distillation, the silane is converted to a hindered phenol compound and / or N, N'-diphenyl-p-phenylene.
In the presence of an amine compound which is a diamine and / or a phenothiazine and a copper dialkyldithiocarbamate and / or an N-nitrosophenylhydroxylamine salt, a hindered phenol compound and / or N,
N'-diphenyl-p-phenylenediamine or / and
A method for distilling acrylic silane, wherein a mixed liquid containing an amine compound which is phenothiazine and phenothiazine and an N-nitrosophenylhydroxylamine salt is supplied from the top of a distillation column. CH ₂ ＣＲCR ¹ COO (X) _m SiR ² _n R ³ _3-n (I) wherein R ¹ is hydrogen, an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 10 carbon atoms And X is CH ₂ C
H ₂ O or CH ₂ or a combination of these two groups, m is 1 to 12, R ² is a hydrolyzable group, R ³ is an alkyl group having 1 to 12 carbon atoms, alkenyl A group or an aryl group, and n is 1 to 3. ]
(2) N-nitrosophenylhydroxylamine salt is
Formula (II) (R ⁴ N (NO) O) _p Y _q (II) wherein R ⁴ is an aryl group having 6 to 10 carbon atoms;
p is 1-4, q is 1-4, and Y is a cation atom or molecule. The method for distilling acrylsilane according to the above (1), which is a compound represented by the following formula (1): (3) Copper dialkyldithiocarbamate has the general formula (I)
_{^{II) (R 5 2 NC (}} = S) S) 2 Cu ... (III) [ wherein, R ⁵ is an alkyl group having 1 to 5 carbon atoms. ]
The method for distilling acrylsilane according to the above item (1) or (2), which is a compound represented by the formula: (4) The hindered phenol compound according to any one of the above items (1) to (3), wherein the hindered phenol compound is a compound in which at least one substituent that gives steric hindrance near the hydroxyl group of the aromatic ring is bonded. The method for distilling acrylic silane according to any one of the above.

Hereinafter, the present invention will be described in detail. In the present invention, when purifying an acrylic silane having a specific structure by distillation, the silane is converted to a hindered phenol compound and / or N, N'-diphenyl-p-phenylenediamine.
Amine compounds that are amines and / or phenothiazines
("Amine compound" in the following description is a specific term
If it does not fit, "N, N'-diphenyl-p-phenyl
Amines which are diamines and / or phenothiazines
Compound ". ) And copper dialkyldithiocarbamate and / or N-nitrosophenylhydroxylamine salt in the presence of a hindered phenol compound and / or an amine compound and an N-nitrosophenylhydroxylamine salt in the upper part of the distillation column. This is a distillation method that is performed while supplying from the reactor.

The distillation method of the present invention is effective for suppressing the spontaneous polymerization of the acrylsilane represented by the general formula (I). The acrylic silane is highly useful, but is liable to cause spontaneous polymerization. CH ₂ = CR in ^{_{1 COO (X) m SiR 2}} n R 3 3 _over n ... (I) [wherein, R ¹ is hydrogen, aryl alkyl group or the carbon number of 1 to 8 carbon atoms is 6 to 10 And X is CH ₂ C
H ₂ O or CH ₂ or a combination of these two groups, m is 1 to 12, R ² is a hydrolyzable group, R ³ is an alkyl group having 1 to 12 carbon atoms, alkenyl A group or an aryl group, and n is 1 to 3. ]

The present invention provides, among others, the compounds represented by the general formula (I)
² is —OC (＝ O) R ⁵ [wherein R ⁵ has 1 to 8 carbon atoms.
An alkenyl group having 1 to 8 carbon atoms, an alkynyl group having 1 to 8 carbon atoms, or an aryl group having 6 to 10 carbon atoms. ], Preferably -OC (= O) CR ⁶
ＣＨCH _{2 wherein} R ⁶ is an alkyl group having 1 to 2 carbon atoms or hydrogen. Or halogen elements, particularly preferably those having a structure of —OC (（O) CH ₃ or a chlorine atom.

Specifically, 3-methacryloxypropyltrichlorosilane, 3-methacryloxypropylmethyldichlorosilane, 3-methacryloxypropyldimethylchlorosilane, 3-acryloxypropyltrichlorosilane, 3-acryloxypropylmethyldichlorosilane, 3-acryloxypropyldimethylchlorosilane,
Examples thereof include 3-methacryloxypropyldimethylacetoxysilane, 3-methacryloxypropyldimethylmethacryloxysilane, 3-acryloxypropyldimethylacetoxysilane, and 3-acryloxypropyldimethylacryloxysilane.

In the present invention, distillation purification is carried out in the presence of a hindered phenol compound and / or an amine compound and copper dialkyldithiocarbamate and / or N-nitrosophenylhydroxylamine salt. Specific examples of the hindered phenol compound used in the present invention include 2,6-di-tert-butyl-4-methylphenol and 2,6-di-tert-butyl-4-dimethylaminomethylphenol. Further, as the amine compound used in the present invention, specifically, N, N′-
Examples include diphenyl-p-phenylenediamine, phenothiazine and the like.

The amount of the hindered phenol compound and / or amine compound used in the present invention is preferably from 1 to 100,000 ppm (in terms of weight), more preferably from 10 to 5000 ppm (in terms of weight), based on acrylsilane. In the present invention, the hindered phenol compound or the amine compound may be used alone, or one or more hindered phenol compounds and one or more amine compounds may be used in combination.

As a specific method of use, a method of adding immediately before the synthesis reaction step of acrylic silane, a method of pre-mixing to the raw material of acrylic silane, and a method of adding to the reaction mixture immediately before the distillation purification step And the like. However, hindered phenol compounds and amine compounds have an excellent effect on suppressing uniform polymerization, but have no effect on suppressing growth polymerization. Therefore, hindered phenol compounds and amine compounds must be used in combination with copper dialkyldithiocarbamate and / or N-nitrosophenylhydroxylamine salt. Must.

The N-nitrosophenylhydroxylamine salt used in the present invention can be represented by the following formula (II). (R ⁴ N (NO) O) _p Y _q (II) wherein R ⁴ is an aryl group having 6 to 10 carbon atoms;
p is 1-4, q is 1-4, and Y is a cation atom or molecule. Specific examples thereof include N-nitrosophenylhydroxylamine ammonium salt, N-nitrosophenylhydroxylamine sodium salt, N-nitrosophenylhydroxylamine potassium salt, and N-nitrosophenylhydroxylamine aluminum salt. The copper dialkyldithiocarbamate used in the present invention can be represented by a compound represented by the following formula (III). _{^{(R 5 2 NC (= S}} ) S) 2 Cu ... (III) [ wherein, R ⁵ is an alkyl group having 1 to 5 carbon atoms. Specifically, copper dimethyldithiocarbamate, copper diethyldithiocarbamate, copper di-n-propyldithiocarbamate, copper diisopropyldithiocarbamate, di-
Copper n-butyldithiocarbamate and the like can be exemplified. These may be used alone or in combination of two or more. Specific methods of use include, for example, a method of adding immediately before an acrylic silane synthesis reaction step, a method of previously mixing the raw material of the acrylic silane, and a method of adding into a reaction mixture immediately before a distillation purification step. can do.

The amount of copper dialkyldithiocarbamate and / or N-nitrosophenylhydroxylamine used in the present invention is 1 to 1 with respect to acrylsilane.
100000 ppm (weight conversion) is preferable, and
000 ppm (weight conversion) is more preferable. However, copper dialkyldithiocarbamate and N-nitrosophenylhydroxylamine salt have an excellent effect on inhibiting the growth polymerization, but have no effect on inhibiting the uniform polymerization. Must.

In the present invention, distillation and purification are carried out while supplying a mixture containing a hindered phenol compound and / or an amine compound and an N-nitrosophenylhydroxylamine salt from the top of the distillation column. By continuously supplying a mixture in which a hindered phenol compound and / or an amine compound and an N-nitrosophenylhydroxylamine salt are dispersed or dissolved from the upper portion of the distillation column, the spontaneous polymerization of acrylsilane vapor inside the distillation column is suppressed. It can be suppressed effectively. The method of supplying the mixed solution includes
There is no particular limitation, and any of a dropping method and a spraying method may be used. Since the N-nitrosophenylhydroxylamine salt is extremely hard to be mixed into the distilled and purified acrylic silane solution, the quality of the product is not deteriorated. The hindered phenol compound and the amine compound can be prevented from being mixed into the distilled and purified acrylic silane solution by appropriately selecting the boiling point of the compound.

Specific examples of the hindered phenol compound and the amine compound used in the mixed solution include 2,6
-T-butyl-4-methylphenol, 2,6-t-butyl-4-dimethylaminomethylphenol,
N, N'-diphenyl-p-phenylenediamine, phenothiazine and the like can be exemplified. These may be used alone or in combination of two or more. The N-nitrosophenylhydroxylamine salt used in the mixture can be represented by the following formula (II). (R ⁴ N (NO) O) _p Y _q (II) wherein R ⁴ is an aryl group having 6 to 10 carbon atoms;
p is 1-4, q is 1-4, and Y is a cation atom or molecule. Specific examples thereof include N-nitrosophenylhydroxylamine ammonium salt, N-nitrosophenylhydroxylamine sodium salt, N-nitrosophenylhydroxylamine potassium salt, and N-nitrosophenylhydroxylamine aluminum salt. These may be used alone or in combination of two or more.

The amount of the hindered phenol compound and / or amine compound to be used in the mixture depends on the shape of the distillation column, but is 0.1 to 10000 ppm based on the amount of acrylsilane volatilized per hour. (In terms of weight), especially 1 to 100 ppm.
(In terms of weight). The supply amount of the N-nitrosophenylhydroxylamine salt used in the mixture is preferably 0.1 to 10000 ppm (in terms of weight) with respect to the amount of acrylic silane that evaporates per hour, and particularly preferably 1 to 1 ppm. It is preferably from 100 to 100 ppm (in terms of weight).

The liquid for dispersing or dissolving the hindered phenol compound and / or the amine compound and the N-nitrosophenylhydroxylamine salt is not particularly limited, but may be reacted with acrylic silane or a polymerization inhibitor. It is preferable that the silane is not mixed with the distilled and purified acrylic silane. Particularly, the acryl silane itself to be distilled and purified or a liquid having a higher boiling point than the acryl silane is preferable.

In the distillation method of the present invention, a gas or air obtained by diluting molecular oxygen with an inert gas may be introduced into the apparatus.

An example of a distillation apparatus that can be used in the present invention will be described with reference to the accompanying drawings. The distillation method of the present invention is most preferably performed using the distillation apparatus shown in FIG. 1, but is not limited to the distillation apparatus unless departing from the technical idea of the present invention. The acrylic silane solution obtained by the synthesis reaction is charged into the distillation still 1 and heated and decompressed to vaporize the acrylic silane. Decompression is
The heating is carried out by a vacuum pump 6 and the heating is carried out by circulating a heating medium through a jacket 7 provided around the distillation still 1. The vaporized acrylic silane is led to the distillation tower 2, goes up the distillation tower 2, is discharged from the upper part of the distillation tower 2, and is led to the aggregator 4. On the other hand, a mixed liquid containing a hindered phenol compound and / or an amine compound and an N-nitrosophenylhydroxylamine salt is charged into the tower top feed liquid tank 3, and a flow control valve 8 is provided.
The mixed solution is supplied into the distillation column 2 while controlling the flow rate by the method described above. The acrylic silane is liquefied by the aggregator 4 and stored in the distillate tank 5. In some cases, it is led to the upper part of the distillation column 2 and distillation purification is performed again.

[0028]

The present invention will be described below in detail with reference to Examples, Comparative Examples and Reference Examples. Note that the present embodiment does not limit the present invention at all.

Example 1 An acrylsilane solution containing 3-methacryloxypropyldimethylchlorosilane as a main component was synthesized from allyl methacrylate and dimethylchlorosilane in the presence of a platinum catalyst by a known method. 0.5 g of phenothiazine and 0.5 g of copper dimethyldithiocarbamate were added to 5 kg of the acrylic silane solution, and the mixture was charged into the distillation still 1 and heated under reduced pressure. First, the pressure inside the apparatus was reduced to 30 kPa, and the top temperature of the distillation column 2 was 60 to 85 ° C.
Then, after distilling off low-boiling components containing allyl methacrylate as a main component, the pressure was reduced to 15 kPa, and the top temperature was 69 to 75 ° C.
Thus, a fraction of 3-methacryloxypropyldimethylchlorosilane was obtained. Meanwhile, the inside diameter of the heli-pack was about 5
From the top of the 0 cm distillation column 2, N-nitrosophenylhydroxylamine aluminum salt in a weight ratio of 2% to 3-methacryloxypropyldimethylchlorosilane;
A solution in which 1,6-weight t-butyl-4-methylphenol having a weight ratio of 1% was dissolved was supplied, and distillation and purification were performed. At the time of the distillation purification, no polymerization in which the viscosity was increased was observed in the acrylsilane solution inside the distillation still 2, and no production of a multiplying polymer was observed. After completion of the distillation purification, the distillation column 2
Inspection of the inside showed no formation of a homogeneous polymer or a propagation polymer.

(Example 2) The distillation purification of Example 1 was repeated five times. At the time of the distillation purification, no polymerization in which the viscosity was increased was observed in the acrylsilane solution inside the distillation still 2, and no production of a vegetative polymer was observed. After the distillation purification was repeated, the inside of the distillation column 2 was inspected, but no formation of a homogeneous polymer or a propagation polymer was found.

(Comparative Example 1) N-Nitrosophenylhydroxylamine aluminum salt in a weight ratio of 2% and 2,6-di-tert-butyl-4-methylphenol in a weight ratio of 1% are dissolved in 3-methacryloxypropyldimethylchlorosilane. Except not supplying the liquid, the distillation purification was carried out in accordance with Example 1. The pressure was reduced to 15 kPa, and a low boiling component mainly composed of allyl methacrylate was distilled off at a tower top temperature of 30 to 69 ° C. Immediately after, a growing polymer was generated inside the distillation column 2 and the distillation operation was disabled because the distillation column was closed.

Comparative Example 2 N-Nitrosophenylhydroxylamine aluminum salt in a weight ratio of 2% and 3,6-di-tert-butyl-4-methylphenol in a weight ratio of 3% were dissolved in 3-methacryloxypropyldimethylchlorosilane. Instead of the solution thus obtained, a solution in which 2,6-di-tert-butyl-4-methylphenol was dissolved at a weight ratio of 2% with respect to 3-methacryloxypropyldimethylchlorosilane was added from the top of the distillation column 2 and distilled. 0.5 g of phenothiazine blended in the acrylic silane solution in kettle 1
Was distilled and refined according to Example 1 except that 0.66 g of 2,6-di-tert-butyl-4-dimethylaminomethylphenol was added instead of
During the distillation, low-boiling components mainly composed of allyl methacrylate were distilled off at a tower top temperature of 30 to 69 ° C., while a growth polymer was generated inside the distillation column 2 and the distillation column was clogged. Operation has been disabled.

(Comparative Example 3) N-Nitrosophenylhydroxylamine aluminum salt in a weight ratio of 2% and 2,6-di-tert-butyl-4-methylphenol in a weight ratio of 3% were dissolved in 3-methacryloxypropyldimethylchlorosilane. Instead of the liquid thus obtained, a liquid in which phenothiazine was dissolved in a weight ratio of 2% with respect to 3-methacryloxypropyldimethylchlorosilane was added from the top of the distillation column 2,
Distillation was performed according to Example 1 except that 0.66 g of 2,6-di-tert-butyl-4-dimethylaminomethylphenol was added instead of 0.5 g of phenothiazine contained in the acrylic silane solution in the distillation still 1. After the purification, the pressure was reduced to 15 kPa, and while the low-boiling component mainly composed of allyl methacrylate was distilled off at a tower top temperature of 30 to 69 ° C., a growth polymer was generated inside the distillation column 2. The distillation operation was not possible because the distillation column was closed.

(Comparative Example 4) 2% by weight of N-nitrosophenylhydroxylamine aluminum salt and 1% by weight of 2,6-di-tert-butyl-4-methylphenol in 3-methacryloxypropyldimethylchlorosilane were dissolved. Instead of the liquid, a liquid in which 2% by weight of N-nitrosophenylhydroxylamine aluminum salt was dissolved in a mineral oil (manufactured by Soken Chemical Co., Ltd .: NeoSK-OIL330) was added from the top of the distillation column 2. Distillation and purification were performed in accordance with Example 1 except for the above. As a result of repeating the distillation purification three times, no polymerization in which the viscosity was increased was observed in the acrylsilane solution inside the distillation still 2, and no generation of a multiplying product was observed. However, after the distillation purification was completed three times, when the inside of the distillation column 2 was inspected,
Generation of a homogeneous polymer was observed.

[0035]

As is clear from the examples and comparative examples, the hindered phenol compound and / or the amine compound and the copper dialkyldithiocarbamate and / or
Alternatively, distillation purification is performed in the presence of an N-nitrosophenylhydroxylamine salt and a mixture containing a hindered phenol compound and / or an amine compound and an N-nitrosophenylhydroxylamine salt supplied from the top of the distillation column. Even if acrylic silane is distilled and refined on an industrial scale, spontaneous polymerization of acrylic silane, which is likely to occur inside the distillation still and inside the distillation column, can be extremely effectively suppressed, and even when repeated distillation is performed, acrylic It was found that spontaneous polymerization of silane can be suppressed.

[Brief description of the drawings]

FIG. 1 is a diagram of a flow sheet of a distillation apparatus.

[Explanation of symbols]

 1. Distillation still 2. Distillation column 3. 3. Top feed liquid tank Condenser 5. Distillate tank 6. Decompression pump 7. Jacket 8. Flow control valve

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C07F 7/00-7/21 CA (STN) REGISTRY (STN) WPI (DIALOG)

Claims (4)

(57) [Claims] 1. A method for purifying an acrylic silane represented by the formula (I) by distillation, wherein the silane is a hindered phenol compound and / or N, N'-diphenyl-p- phenyl.
In the presence of an amine compound which is an enylenediamine or / and a phenothiazine and a copper dialkyldithiocarbamate and / or N-nitrosophenylhydroxylamine salt, the hindered phenol compound and / or N, N ' -Diphenyl-p-phenylenediamine or
And / or an amine compound which is phenothiazine, and N-
A method for distilling acrylic silane, wherein the method is carried out while supplying a mixed solution containing a nitrosophenylhydroxylamine salt from an upper portion of a distillation column. CH ₂ ＣＲCR ¹ COO (X) _m SiR ² _n R ³ _3-n (I) wherein R ¹ is hydrogen, an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 10 carbon atoms And X is CH ₂ C
H ₂ O or CH ₂ or a combination of these two groups, m is 1 to 12, R ² is a hydrolyzable group, R ³ is an alkyl group having 1 to 12 carbon atoms, alkenyl A group or an aryl group, and n is 1 to 3. ] 2. An N-nitrosophenylhydroxylamine salt of the formula (II) (R ⁴ N (NO) O) _p Y _q ... (II) wherein R ⁴ is an aryl group having 6 to 10 carbon atoms. And
p is 1-4, q is 1-4, and Y is a cation atom or molecule. The method for distilling acrylsilane according to claim 1, which is a compound represented by the formula: 3. dialkyldithiocarbamate copper, formula _{^{(III) (R 5 2 NC}} (= S) S) 2 Cu ... (III) [ wherein, R ⁵ is an alkyl group having 1 to 5 carbon atoms . ]
The method for distilling acrylic silane according to claim 1 or 2, which is a compound represented by the following formula: 4. The acrylic resin according to claim 1, wherein the hindered phenol compound has at least one substituent which gives steric hindrance in the vicinity of the hydroxyl group of the aromatic ring. Silane distillation method.