JPS5811857B2 - Azonitrile bag - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides two compounds useful as radical polymerization initiators, blowing agents, etc.
,2'-azobis(2,4-dimethylvaleronitrile)
(Hereinafter abbreviated as ABVN.

).

Specifically, methyl isobutyl ketoatine (hereinafter abbreviated as MBKA) is prepared in the presence of metal salts selected from the group consisting of zinc, tin, iron, copper, and aluminum, alone or in combination.

) and hydrogen cyanide (2,2'-hydrazobis(2°4-dimethylvaleronitrile) (hereinafter abbreviated as HBVN).

) is oxidized with halogen etc. to produce ABVN rich in low melting point isomers.
The present invention relates to a manufacturing method for obtaining.

ABVN is particularly suitable for polymerization initiators such as vinyl chloride,
Acrylonitrile has far superior performance in terms of polymerization efficiency and physical properties of the resulting polymer compared to other polymerization initiators, and is suitable for all types of vinyl compounds such as ethylene, styrene, acrylic esters, methacrylic esters,
It has recently become increasingly important as an effective polymerization initiator for vinyl fluoride, vinyl acetate, acrylamide, acrylic acid, methacrylic acid, vinylpyridine, and the like.

By the way, ABVN is Oberburger (C, G.

Overberger), Journal of American Chemical Society (Journal of A
meri-can chemical 5ociety
) Volume 73, page 2618, melting point 56°
It consists of two types of isomers resulting from stereoisomerism, men-form and di-form, which have a temperature of C to 57°C or 74 to 77°C.

The decomposition rate constant is low melting point compound K (sec-1×104)
=2.89 (69.9°C), high melting point compound K (sec
-1×104)=1.98 (69,8°C) and 1
Usually, depending on the known manufacturing method, the melting point is 48°C to 65°C,
Provided as a mixture of isomers.

The ratio of low melting point compounds and high melting point compounds in ABVN is determined empirically based on the melting point width or infrared absorption spectrum.

It is measured by analysis of nuclear magnetic resonance spectra, etc.

For example, in the infrared absorption spectrum, the wavenumber is 7201-1°73
Comparing the absorption of 5 cfrL-”, the low melting point compound is 7
735cIrL has sharp absorption at 20cm-1
-1 has no absorption, and the opposite is true for high melting point compounds.

Furthermore, in the case of a 1:1 mixture, 720 cm-” and 7
The absorption intensity at 35 cm-1 shows an approximately 1:1 ratio.

On the other hand, when we compare the solubility of low-melting point compounds, high-melting point compounds, and mixtures made by conventional manufacturing methods in various organic solvents, we find that the solubility of low-melting point compounds is several times higher than that of other compounds, and the difference is especially noticeable at low temperatures. appear.

Therefore, if it is possible to produce ABVN rich in low-melting compounds, it is possible to use ABVN which has higher polymerizability and is extremely advantageous in terms of solvent selection than conventional mixtures, providing a new polymerization initiator. is important.

The present inventors kept the above points in mind and completed the present invention as a result of intensive research.

In the method of the present invention, MBKA is produced by a known method, zinc,
In the presence of tin, copper, iron, aluminum hydrochlorides, bromates, and acid salts such as sulfates, nitrates, acetates, oxalates, etc., Friedel-Craft catalysts are preferred.

Reacts with hydrogen cyanide in the presence of chlorides and bromides of zinc, tin, iron, copper, and aluminum, producing HBVN.
Using HBVN with such a history as a starting material, it is oxidized with halogen or the like to produce ABVN rich in low-melting compounds.

The reaction to obtain HBVN as a starting material is usually carried out at room temperature to 40°C for 5 to 10 hours with zinc, tin, copper, and iron.

Aluminum salt is 0.05% to 30% of MBKA
%, preferably 0.5 to 10%, alone or in admixture.

Hydrogen cyanide is preferably reacted in an anhydrous state.

As the solvent used in the reaction, any ordinary solvent can be used without any problem as long as it is inert to MBKA, HBVN, and hydrogen cyanide.

The oxidation reaction of the obtained HBVH was carried out at -20°C to 30°C.

Preferably, it may be carried out at 20° C. or lower according to a conventional ABVN manufacturing method.

ABVN produced by this method can be obtained almost quantitatively from MBKA, and is rich in low-melting compounds with high polymerization activity and high solubility, and can be provided as a new polymerization initiator, making a great contribution to this field. .

For example, the low melting point compound-rich polymerization initiator of the present invention includes a polymerization initiator such as ethylene, styrene, acrylic ester, vinyl chloride, vinyl acetate, acrylamide, acrylic acid, methacrylic acid, vinylpyridine, unsaturated polyester, etc. and be used effectively.

Examples will be described below. Example 1 Add 0.5 g of zinc chloride to 59 g of MBKA and stir.

17 g of anhydrous hydrogen cyanide is added dropwise at 10° C. to 35° C. under water cooling, and the mixture is allowed to react at room temperature for 10 hours.

Add 100 ml of methanol to the reaction mixture, and add 2 ml of methanol under stirring.
2 g is introduced at 5° C. to 20° C. under ice cooling, and water is added to obtain 73.6 g of precipitated ABVN.

Melting point 56-58°C, content 99.8%, hydrazo content 0.
05%, (about 98% low melting point compound) Example 2 1 g of stannic chloride was added to 59 g of MBKA, and the mixture was stirred.

18 g of anhydrous hydrogen cyanide is added dropwise at 10° C. to 35° C. under water cooling, and the mixture is allowed to react at room temperature for 8 hours.

Add 100 ml of methanol to the reaction mixture, and add 5 ml of bromine under stirring.
4 g was added dropwise at 5° C. to 20° C. under ice cooling, and water was added to obtain 72.5 g of precipitated ABVN.

Melting point 55-57°C1 content 99.5%, hydrazo content 0
．． 1% (about 96% low melting point compound) Example 3 Add 2 g of aluminum chloride to 59 g of MBKA.

While stirring, 18 g of anhydrous hydrogen cyanide was heated to 10°C to 3°C under water cooling.
The reaction was carried out at 5°C and left to react at room temperature for 10 hours.

Add 100 ml of methanol to the reaction mixture, and add 2 ml of methanol under stirring.
2 g was introduced at 5° C. to 20° C. under ice cooling, and water was added to obtain 71.5 g of precipitated ABVN.

Melting point: 53°C to 60°C, content: 99.5%, hydrazo content: 0.1%, (low melting point compound: approx. 93%) Comparative Example MBKA: 59 g, with stirring, anhydrous hydrogen cyanide: 23 g
is added dropwise at 10°C to 35°C under water cooling, and the mixture is allowed to react at room temperature for 50 hours.

Add 100 d of methanol to the reaction mixture, and add 22 d of methanol under stirring.
A.
Obtain BVN58.9.

Melting point: 43-58°C, content: 99.5%, hydrazo content: 0.
1%, (low melting point compound approx. 50%, high melting point compound approx. 50%
) Examples 4-13 Instead of aluminum chloride in Example 3.

The following table shows the results of reactions and treatments using various metal salts.

Claims (1)

[Claims] 1 2,2'-Hydrazobis(2 2,2′-azobis(2,4
-dimethylvaleronitrile) production method.