JPH0348187B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a novel diisocyanate compound and a method for producing the same, particularly a novel diisocyanate compound obtained from tetraphenylthiophene and a method for producing the same.

(Prior art) In the past, wholly aromatic polyimides, polyamides, polyazomethines, etc. have excellent heat resistance and excellent mechanical properties, and have been widely used as industrial materials. There were many problems with its moldability.
Among these resins, polyimide produced using diaminotetraphenylthiophene as a raw material,
Polyamide and polyazomethine are soluble in organic solvents, have excellent heat resistance, electrical properties, and mechanical properties, and are known to be extremely useful as industrial materials. Examples of such polyimide resins are (In the formula, R is a tetravalent organic group.) Regarding this, for example, a report by Imai et al. is published in the Journal of Polymer Science, Polymer Chemistry Edition (J.
Polymer Sci., Polymer Chemistry Edition),
It is described in Volume 22, pages 2198 and 3771 (1984); Vol. 28 of the same magazine, pages 1979 and 2077 (1985); and Japanese Patent Application Laid-Open No. 60-49030.

Conventionally, the polyimide resin is manufactured from, for example, a tetracarboxylic dianhydride corresponding to the above formula and diaminotetraphenylthiophene, but the reaction is not only a two-step reaction in which an amide compound is used in the middle. Because it requires a reaction temperature of 200°C or higher, it is not only disadvantageous as an industrial production method, but also tends to involve side reactions and decomposition reactions due to high temperatures during the reaction.
This method was unsatisfactory as a method for producing polyimide resin that has excellent electrical and mechanical properties.

(Problems to be Solved by the Invention) The present inventors have developed a method for producing the polyimide resin using a highly reactive diisocyanate compound obtained from tetraphenylthiophene instead of the diaminotetraphenylthiophene. If this method is used, a heat-resistant polyimide resin that is soluble in organic solvents and has excellent moldability can be obtained in a single-step reaction at a relatively low temperature, which makes it very advantageous as an industrial production method. We thought that it might also be expected to improve the physical properties of molded polyimide resins, but such diisocyanate compounds have not been known until now. The purpose of the present invention is to establish a method for synthesizing this new diisocyanate compound and to confirm the usefulness of this diisocyanate compound.

(Means for Solving the Problems) The present inventors have conducted intensive research on a method for obtaining such a novel diisocyanate compound, and as a result, we have discovered that diaminotetraphenylthiophene is reacted with phosgene or trichloromethyl chloroformate. We have completed the present invention by confirming that this objective can be achieved by conducting the following steps.

The first invention of the present invention is the formula It is a diisocyanate compound represented by

The second invention of the present invention is the formula In producing the diisocyanate compound represented by the formula This is a method for producing a diisocyanate compound, in which diaminotetraphenylthiophene represented by the following formula is reacted with phosgene or trichloromethyl chloroformate in an organic solvent at a temperature of 0 to 200°C.

The diaminotetraphenylthiophene is
It can be easily produced in two steps from tetraphenylthiophene obtained from benzyl chloride and sulfur, which are commercially available at low cost. For example, from W. Dilthey (J.
Prakt Chem.) Volume 2, pages 151 and 257 (1938
Published in 2013).

The solvent used in the reaction between the diamine and phosgene or trichloromethyl chloroformate may be any organic solvent that does not react with the reaction reagent and product in this reaction, such as cyclohexane,
Examples of organic solvents include benzene, toluene, xylene, naphthalene, tetralin, chlorobenzene, orthodichlorobenzene, dichloroethane, and tetrachloroethane.

The temperature applied to this reaction is usually from 0°C to
200°C, preferably 40°C to 100°C. The amount of phosgene or trichloromethyl chloroformate used in this reaction is suitably 3 to 10 equivalents relative to diaminotetraphenylthiophene.
Reaction time varies greatly depending on the amount of reagent used, type of solvent, reaction temperature, etc., but is usually from 30 minutes to
20 hours, preferably 1 to 5 hours.

The production of the diisocyanate compound proceeds almost quantitatively, and if the solvent is distilled off from the reaction product and the residue is purified by an appropriate method, the diisocyanate compound can be obtained in a good yield.

(Example) The present invention will be explained in more detail with reference to Examples below.

Example 1 1.00 g (2.4 mmol) of 2,5-bis(4-aminophenyl)-3,4-diphenylthiophene
Suspended in 25 ml of 1,2-dichloroethane, 1.16 ml
(9.6 mmol) of trichloromethyl chloroformate was added and stirred at 80° C. for 1.5 hours under a nitrogen atmosphere.
The solvent was removed under reduced pressure to obtain 1.13 g (100%) of product. This was sublimed at 0.1 atm and 170°C to produce a purified product (2,5-bis(4-isocyanatophenyl)-
3,4-diphenylthiophene) was obtained. melting point,
172-174℃.

Infrared absorption spectrum: 2275cm ^-1 (N=C=
O).

Elemental analysis value C H N S Calculated value (%) 76.59 3.82 5.95 6.80 Actual value (%) 75.93 3.69 5.83 6.40 Reference example 1 0.470 g (1 mmol) of 2,5-bis(4-isocynatophenyl)-3, 4-Diphenylthiophene, 0.322 g (1 mmol) of benzophenonetetracarboxylic dianhydride, and 40 mg of triethylenediamine were dissolved in 3.5 ml of benzonitrile and stirred at 140° C. for 3 hours under a nitrogen atmosphere. The resulting gel-like product was washed with acetone and dried under reduced pressure. It was purified by reprecipitation with a metacresol-methanol system. Yield 0.704g (100%).

Intrinsic viscosity 1.49 dl/g (measured in sulfuric acid at a concentration of 0.5 g/dl at 30°C) Infrared absorption spectrum: 1775, 1720, 1360,
723 cm ^-1 .

Elemental analysis value C H N S Calculated value (%) 76.70 3.41 3.98 4.55 Actual value (%) 76.42 3.17 4.03 4.94 The obtained polyimide resin was soluble in metacresol, orthochlorophenol, etc. 10% weight loss temperature in air by thermogravimetry, 550°C; glass transition temperature, 360°C by dynamic mechanical measurement.

Reference example 2 2,5-di(4-aminophenyl)-3,4-
5ml of 418mg (1mmol) of diphenylthiophene
was dissolved in dehydrated m-cresol and heated to 40°C under a nitrogen stream. Add 322 mg (1 mmol) to this solution.
3,4,3',4'-benzophenonetetracarboxylic dianhydride was added, a small amount of remaining tetracarboxylic dianhydride was washed away with 2.4 ml of dehydrated m-cresol, and the reaction solution was added. added. 3 hours at 45℃
The reaction was carried out at 150°C for 3 hours with stirring. The reaction apparatus was equipped with a distillation head and a Liebig condenser, and the solvent m-cresol was distilled under a nitrogen stream at an oil bath temperature of 250°C. At this time, dehydrated m-cresol was added so that the liquid volume in the reactor was maintained at about 7 ml. After performing this operation for 5 hours, the mixture was cooled to room temperature under a nitrogen stream to obtain a yellow polyimide resin solution.
This solution was poured into 300 ml of methanol to obtain a polyimide resin precipitate, which was dried under reduced pressure at 100° C. for 4 hours. On the other hand, the m-cresol solution at the end of the reaction was cast on a glass plate to obtain a polyimide film.

The intrinsic viscosity of the resulting resin was 0.63 (measured at 30° C. at a concentration of 0.5 g/dl in sulfuric acid).

Infrared absorption spectrum (film) cm ^-1 ;
1780, 1720, 1360, 720 Elemental analysis value C H N S Calculated value (%) 76.70 3.41 3.98 4.55 Actual value (%) 76.02 3.36 3.64 4.51 The produced polyimide resin contains sulfuric acid, m-cresol, N-methyl-2- It was soluble in pyrrolidone.

(Effects of the Invention) The present invention provides a novel diisocyanate compound represented by the formula and a method for producing the same. The diisocyanate compound obtained in the present invention can be reacted with a tetracarboxylic dianhydride to form a polyimide using the conventional method of reacting a diamine compound represented by the formula with a tetracarboxylic dianhydride. Compared to synthetic methods, the reaction can proceed easily in one step under mild conditions, and polyimide resins can be obtained in good yields, and the resulting polyimide resins also generally have a higher molecular weight than those obtained by conventional methods.
Moreover, since it is soluble in organic solvents, it can be used as an industrial material with excellent heat resistance, electrical properties, and mechanical properties.

Claims (1)

[Claims] 1 formula A diisocyanate compound represented by 2 formulas In producing the diisocyanate compound represented by the formula 1. A method for producing a diisocyanate compound, which comprises reacting diaminotetraphenylthiophene represented by phosgene or trichloromethyl chloroformate in an organic solvent at a temperature of 0 to 200°C.