JPH07116296B2 - Method for producing polysulfide resin - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a polysulfide resin having excellent heat resistance.

(Prior Art) Polysulfide resins are conventionally produced by reacting dithiols and dihalides in an organic solvent in the presence of an inorganic or organic base. For example, Balon and Bla
nk (Makromol, Chem, 140 , 83 (1970)) produces a polysulfide resin by reacting dithiol and dichloride in N, N-dimethylformamide in the presence of anhydrous potassium carbonate. However, in this method, there are problems that the organic solvent that can be used is limited because a large amount of acid acceptor is used, and purification of the polymer after the reaction treatment is troublesome.

In addition, as a method for producing polysulfide by reacting dithiol and dihalide, Imai et al. (Makromol, Che
m, Rapid Commun, 1 , 681 (1980)), there is a production method by a reaction in a two-phase system using a phase transfer catalyst. However, this method has a problem that the use thereof is limited only to the case of a monomer having a very high reactivity because an expensive phase transfer catalyst is used and the reaction conditions are gentle.

(Problems to be Solved by the Invention) It is difficult to obtain a high molecular weight polysulfide because the reaction conditions of the polysulfide resin produced by the conventional method are limited, and purification of the obtained polymer is troublesome. There was a problem. Therefore, it is an object of the present invention to provide a method for producing a polysulfide resin which has a molecular weight equal to or higher than that of a conventional method and is easily purified.

(Means for Solving the Problem) The inventors of the present invention have made earnest efforts to invent a method for producing a polysulfide resin having a molecular weight equal to or higher than that of a conventional method and easily purified, and completed the present invention. .

That is, the present invention provides (1) the general formula ^{(I) S-R 1 -S} -R 2 n (I) ( wherein R ^1, R ² is one or more divalent organic group R ¹
And R ² are the same or different, and n is an integer of 2 or more) in the production of the polysulfide resin represented by the general formula (II) (In the formula, R ¹ is a divalent organic group, R ³ , R ⁴ , and R ⁵ are aliphatic organic groups having 1 to 3 carbon atoms or a phenyl group, and R ³ , R ⁴ , and R ⁵ are the same or different) One or more kinds of S, S′-bis (silylated) dithiol represented by the following formula and general formula (III) X—R ² —X (III) (wherein R ² is a divalent organic group, X Is a halogen atom), and one or more dihalides represented by the formula (1) are reacted in the presence or absence of a catalyst in an organic solvent or without a solvent, (2) ) S, S′-bis (silylated) dithiol is S, S ′
The method for producing a polysulfide resin according to claim 1, which is -bis- (trimethylsilyl) dithiol.

The polysulfide resin represented by the general formula (I) is
It is produced from S, S′-bis (silylated) dithiol represented by the general formula (II) and a dihalide represented by the general formula (III), and the trialkylsilyl group is a trimethylsilyl group, a triethylsilyl group, Examples thereof include a triisopropylsilyl group, a triphenylsilyl group, an ethyldimethylsilyl group, an isopropyldimethylsilyl group, a dimethylphenylsilyl group, a dimethylpropylsilyl group and a diphenylmethylsilyl group, with a trimethylsilyl group being most preferred. Examples of S, S′-bis (trialkylsilyl) dithiol represented by trimethylsilyl group include, for example, S, S′-bis (trimethylsilyl)-
4,4'-oxybis (benzenethiol), S, S'-bis (trimethylsilyl) -4,4'-bis (benzenethiol), S, S'-bis (trimethylsilyl) -1,4-benzenedithiol, S , S'-bis (trimethylsilyl) -4,
4'-methylenebis (benzenethiol), S, S'-bis (trimethylsilyl) -p-xylylenedithiol, S,
Examples thereof include S'-bis (trimethylsilyl) -m-xylylenedithiol. Examples of the dihalide include 4,4'-dichloro-3,3'-dinitrodiphenyl sulfone, 4,4'-dichlorodiphenyl sulfone, 4,4'-difluorodiphenyl sulfone and 4,4'-dibromo-3,3. ′
-Dinitrodiphenyl sulfone, 4,4'-difluorobenzophenone, 4,4'-dichlorobenzophenone, α,
α'-dichloro-p-xylene, α, α'-dibromo-
p-xylene, α, α′-dichloro-m-xylene,
Examples thereof include α, α′-dibromo-m-xylene, 1,4-dichlorobenzene, 1,3-dichlorobenzene, 1,4-difluorozenzene and 1,3-difluorobenzene. As the solvent, N, N-dimethylformamide, N, N
-Dimethylaceamide, N-methyl-2-pyrrolidone,
Quinoline, hexamethylphosphoramide, sulfolane and the like can be used, and a mixed solvent thereof may be used. It is also possible to use a catalyst, and it is preferable to use a fluoride such as potassium fluoride or cesium fluoride.

(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1 0.624 g (1.65 mmol) of S, S'-bis (trimethylsilyl) -4,4'-oxybis (benzenethiol) and 0.6
21 g (1.65 mmol) of 4,4'-dichloro-3,3'-dinitrophenyl sulfone were stirred in 8.2 ml of hexamethylphosphoramide under nitrogen atmosphere at 50 ° C for 24 hours. The obtained reaction mixture was poured into a large amount of methanol to obtain a yellow powdery polymer. The results are shown in Table-1.

Comparative Example 1 0.469 g (2.00 mmol) 4,4'-oxybis (benzenethiol), 0.754 g (2.00 mmol) 4,4'-dichloro-3,3'-dinitrodiphenyl sulfone and 0.62 m
l (4.4 mmol) triethylamine was stirred in 10 ml hexamethylphosphoramide under nitrogen atmosphere at 50 ° C. for 24 hours. The obtained reaction mixture was poured into a large amount of water to obtain a yellow powdery polymer. The results are shown in Table-1.

Example 2 0.375 g (0.991 mmol) of S, S'-bis (trimethylsilyl) -4,4'-oxybis (benzenethiol) and 0.3
74 g (0.991 mmol) of 4,4'-dichloro-3,3'-dinitrophenyl sulfone were stirred in 5.0 ml of quinoline under nitrogen atmosphere at 50 ° C for 24 hours. The obtained reaction mixture was poured into a large amount of methanol to obtain a yellow powdery polymer. The results are shown in Table-1.

Example 3 0.582 g (1.61 mmol) of S, S'-bis (trimethylsilyl) -4,4'-bis (benzenethiol) and 0.606 g
(1.61 mmol) 4,4'-dichloro-3,3'-dinitrodiphenyl sulfone was stirred in 8.0 ml hexamethylphosphoramide under nitrogen atmosphere at 50 ° C for 24 hours. The obtained reaction mixture was poured into a large amount of methanol to obtain a yellow powdery polymer. The results are shown in Table-1.

Example 4 0.562 g (1.96 mmol) S, S'-bis (trimethylsilyl) -1,4-benzenedithiol and 0.739 g (1.96 mmol) 4,4'-dichloro-3,3'-dinitrodiphenyl sulfone were added. The mixture was stirred in 9.8 ml of hexamethylphosphoramide under a nitrogen atmosphere at 50 ° C for 24 hours. The obtained reaction mixture was poured into a large amount of methanol to obtain a yellow powdery polymer. The results are shown in Table-1.

Comparative Example 2 0.800 g (3.40 mmol) of 4,4'-oxybis (benzenethiol), 0.976 g (3.40 mmol) of 4,4'-dichlorodiphenyl sulfone and 1.08 g (7.80 mmol).
Of anhydrous potassium carbonate in 10 ml of N, N-dimethylformamide was stirred at 150 ° C. for 24 hours under a nitrogen atmosphere. The obtained reaction mixture was poured into a large amount of methanol and washing was repeated to obtain a light brown powdery polymer. The results are shown in Table-1.

Example 5 0.7637 g (1.65 mmol) of S, S'-bis (triethylsilyl) -4,4'-oxybis (benzenethiol) and 0.6
21 g (1.65 mmol) of 4,4'-dichloro-3,3'-dinitrodiphenyl sulfone were stirred in 8.3 ml of hexamethylphosphoramide under nitrogen atmosphere at 50 ° C for 24 hours. The obtained reaction mixture was poured into a large amount of methanol to obtain a yellow powdery polymer. The results are shown in Table-1.

(Effect of the Invention) According to the present invention, it becomes easy to obtain a high molecular weight polysulfide having excellent heat resistance, and it is easy to purify the obtained polymer.

Claims (2)

[Claims] 1. A compound represented by the general formula (I) S—R ¹ —S—R ² _n (I) (wherein R ¹ and R ² are one or more divalent organic groups, R ¹
And R ² are the same or different, and n is an integer of 2 or more) in the production of the polysulfide resin represented by the general formula (II) (In the formula, R ¹ is a divalent organic group, R ³ , R ⁴ , and R ⁵ are aliphatic organic groups having 1 to 3 carbon atoms or a phenyl group, and R ³ , R ⁴ , and R ⁵ are the same or different) One or more kinds of S, S′-bis (silylated) dithiol represented by the following formula and general formula (III) X—R ² —X (III) (wherein R ² is a divalent organic group, X Represents a halogen atom) with one or more dihalides represented by the formula (1) in the presence or absence of a catalyst in an organic solvent or without a solvent. 2. S, S'-bis (silylated) dithiol is S,
The method for producing a polysulfide resin according to claim 1, which is S'-bis- (trimethylsilyl) dithiol.