JP2697161B2 - Novel polyimide resin and its manufacturing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a novel polyimide having excellent low-temperature moldability and solvent resistance, and a method for producing the same.

[Conventional technology]

Polyimide resins have the highest heat resistance among various resins, but are generally infusible and insoluble, and thus have poor molding workability. In order to improve moldability, attempts have been made to obtain a solvent-soluble, low softening point polyimide using various monomers. For example, JP-A-60-258228, JP-A-63-152630, JP-A-64-22963, JP-A-63-72755 and JP-A-63-500870 disclose a diamine component. And a diamine of the following formula (A) and 4,
4'-bis (3,4-dicarboxyphenoxy) diphenylsulfide dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 2,2-bis [ Examples thereof include polyimides obtained from acid dianhydrides such as 4- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride. These polyimides are used in organic solvents such as N-methylpyrrolidone and methylene chloride. It is clear that it will dissolve. Also, these polyimides have a relatively low glass transition point and, therefore, a relatively low softening point.

Formula (A) [Problems to be solved by the invention] Polyimide shown in the above publication is solvent-soluble,
This means that the molded article has poor solvent resistance.
In general, it is difficult to simultaneously achieve solvent resistance and a low softening point in polyimide, but the present invention provides a polyimide having excellent solvent resistance while keeping the softening point low.

[Means for solving the problem]

The present invention relates to a compound of the formula (I) (Where R is the formula (a) Or formula (b) A) a polyimide resin having a repeating unit represented by the formula:

The polyimide resin preferably has a softening point of 130 to 180
° C. If the softening point is too low, the physical properties of the polyimide resin tend to decrease.

The polyimide resin of the present invention comprises 4,4 '-[1,4-phenylenebis (1-methylethylidene)] bisaniline (BA
P) and 4,4 '-[1,4-phenylenebis (1-methylethylidene)] bisphenylbistrimellitate dianhydride (BAPBT) or 4,4'-[1,3-phenylenebis ( 1-methyleneethylidene)] bisaniline (BA
M) and 4,4 '-[1,3-phenylenebis (1-methylethylidene)] bisphenylbistrimellitate dianhydride (BAMBT). In this case, after obtaining a polyamic acid from BAP or BAM which is a diamine and BAPBT or BAMBT which is an acid dianhydride, a method of thermally ring-closing or chemically ring-closing using a ring-closing agent, the above-described diamine or corresponding thereto A method of obtaining a polyimide in one step by heating the diisocyanate to be produced and the above-mentioned acid dianhydride or an acid derivative such as a diester thereof.

These methods will be described in more detail. When diamines are used as a partner for the reaction of the acid dianhydride, they are used in an organic solvent, if necessary, in the presence of a catalyst such as tributylamine, triethylamine, or triphenyl phosphite, at 100 ° C or higher, preferably 180 ° C or higher. A method of directly obtaining polyimide by heating to imidization (the catalyst is preferably used in an amount of 0 to 15% by weight, more preferably 0.01 to 15% by weight, based on the total amount of the reaction components. Preferred), an acid dianhydride and a diamine are reacted in an organic solvent at a temperature of less than 100 ° C. to produce a varnish of a polyamic acid which is a precursor of a polyimide, and thereafter, the varnish is heated to be imidized, Ring closing agents such as acid anhydrides such as acetic anhydride, propionic anhydride and benzoic anhydride, carbodiimides such as dicyclohexylcarbodiimide, and, if necessary, pyridine, isoquinoline, A method of chemically ring-closing (imidizing) by adding a ring-closing catalyst such as trimethylamine, aminopyridine, imidazole or the like (the ring-closing agent and the ring-closing catalyst are used within a range of 1 to 8 mol per mol of acid anhydride, respectively). Is preferred).

As the organic solvent, N-methyl-pyrrolidone (NM
P), N, N'-dimethylacetamide, N, N-dimethylformamide (DMF), dimethylsulfoxide, sulfolane, hexamethylphosphoric triamide, 1,3-dimethyl-
Aprotic polar solvents such as 2-imidazolidone; phenol solvents such as phenol, cresol, xylenol, and p-chlorophenol;

These solvents include benzene, toluene, xylene, methyl ethyl ketone, acetone, tetrahydrofuran, dioxane, monoglyme, diglyme, methyl cellosolve, cellosolve acetate, methanol, ethanol,
Solvents such as isopropanol, methylene chloride, chloroform, tricrene, tetrachloroethane and the like can be used as a mixture.

In the production of the above-mentioned polyimide and polyamic acid as a precursor thereof, a solid-phase reaction, a melting reaction at 300 ° C. or lower, or the like can be used as the case may be.

When diisocyanate is used as a reaction partner of the acid dianhydride, the reaction can be carried out according to the above-described method for directly obtaining a polyimide. However, it is sufficient that the reaction temperature is at least room temperature, especially at least 60 ° C.

In the present invention, the acid dianhydride and its reaction partner are preferably used in approximately equimolar amounts, but an excess amount of any one is allowed to be 10 mol%, particularly preferably up to 5 mol%.

The polyimide resin according to the present invention also has N, N '-[4,
4 '-[1,4-phenylenebis (1-methylethylidene)] bisaniline] bistrimellitimide (hereinafter referred to as "imidedicarboxylic acid I") is 4,4'-[1,4-phenylenebis (1-methylethylidene)] Bisphenol is reacted, or N, N '-[4,4'-[1,3-phenylenebis (1-methylethylidene)] bisaniline] bistrimeritimide (hereinafter referred to as "imidodicarbanoic acid II")
) And 4,4 '-[1,3-phenylenebis (1-methylethylidene)] bisphenol. In this case, the above-mentioned imidodicarboxylic acid I or II and the above-mentioned bisphenol are subjected to a heat polycondensation reaction or a direct polycondensation reaction using a condensing agent such as phosphite or tosyl chloride, and the diacid chloridone of the above-mentioned imidodicarboxylic acid I or II And a low-temperature polymerization reaction of the above with bisphenol.

The methods (1) and (2) may be performed in the same manner as in the ordinary polyester polycondensation method. Regarding direct polycondensation, Mitsuru Ueda, Polymer 35 (2) 128 (1986), Tofuji Higashi, Journal of the Adhesion Society of Japan, 24 (12) 504 (1988), Ryuichi Takazawa et al., Poly
mer preprints, Japan, 34 (6) 1345 (1985).

Further, the resin according to the present invention, trimellitic anhydride, BAP
Alternatively, BAM and the above-mentioned bisphenol can be obtained by a method of obtaining a polyamic acid in the same vessel using a condensing agent such as trisilyl chloride, and then heating or chemically closing the ring. See Hozumi Tanaka et.
al., Proceedings / Abstructs of Third International
Conference on Polyimide p.64 (1988).

The polyimide according to the present invention can be used as a molded product, an adhesive or the like.

The polyimide according to the present invention can be appropriately produced from its precursor and used.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these ranges.

Example 1 In a four-necked flask equipped with a stirrer, a thermometer, a nitrogen gas inlet tube, and a downward cooling tube, 3.44 g of BAM, 6.94 g of BAMBT, 42 g of N-methylpyrrolidone, and 0.3 g of triphenyl phosphite were placed.
When the heating and stirring were continued at 0 ° C., the resin was deposited.
After continuing heating and stirring for an additional hour, cool to room temperature,
Filtration gave a resin. After repeatedly washing with methanol, drying was performed to obtain a resin powder.

Example 2 In a four-necked flask equipped with a stirrer, a thermometer, a calcium chloride tube, and a nitrogen glass introduction tube, 3.44 g of BAM and 41.5 g of N, N-dimethylformamide were added and dissolved.
6.94g of APBT was added little by little. After reacting at 10 ° C. or less for 3 hours, 2.6 g of acetic anhydride and 20 g of pyridine were added. When stirring was continued at room temperature, a resin was deposited, but stirring was further continued for 1 hour. The resin obtained by filtration was washed repeatedly with methanol, and then dried to obtain a resin powder.

Comparative Example 1 Example 1 except that 6.94 g of BAPBT was used instead of BAMBT
The reaction was carried out in the same manner as described above to obtain a homogeneous solution of polyimide.
After pouring into water and reprecipitating, it was pulverized, washed repeatedly with methanol, and dried to obtain a resin powder.

Comparative Example 2 A reaction was carried out in the same manner as in Example 1 except that 5.76 g of 2,2-bis (p-trimellitoxyphenyl) propanoic acid dianhydride was used instead of BAMBT to obtain a homogeneous polyimide solution. After pouring into water and reprecipitating, it was pulverized, washed repeatedly with methanol, and dried to obtain a resin powder.

Using the resin powders obtained in Example 1, Example 2, Comparative Example 1 and Comparative Example 2, solubility and softening point were measured.

The solubility was determined by mixing 5% by weight of the resin powder and 95% by weight of the solvent shown in Table 1 and then allowing the mixture to stand at room temperature for 1 day, and visually determining the solubility.
The evaluation was ○: dissolved, Δ: swelled, ×: insoluble.

The softening point is a high-end flow tester manufactured by Shimadzu Corporation.
The measurement was performed at a load of 50 kg / cm ² and a temperature rising rate of 5 ° C./min using a nozzle having a length of 1 mm and a length of 10 mm.

 Table 1 shows the results.

The physical properties and the like of the resins obtained in Example 1 and Example 2 are as follows.

 Resin obtained in Example 1: (1) Thermal decomposition temperature 418 ° C (2) IR spectrum (KBr method) As shown in FIG.

 Resin obtained in Example 2: (1) Thermal decomposition temperature 431 ° C. (2) IR spectrum (KBr method) As shown in FIG.

From the above, the resin obtained in Example 1 is represented by the general formula (I)
Is a polyimide resin having a repeating unit in which R is represented by the formula (a), and the resin obtained in Example 2 is a resin in which R in the general formula (I) is represented by the formula (b) It was a polyimide resin having a repeating unit.

〔The invention's effect〕

The polyimide resin according to claim 1 or obtained by claim 2 has excellent solvent resistance while keeping the softening point low.

[Brief description of the drawings]

FIG. 1 shows the IR spectrum of the resin obtained in Example 1, and FIG. 2 shows the IR spectrum of the resin obtained in Example 2.

Claims (2)

(57) [Claims] (1) a repeating unit represented by the general formula (I): (Where R is the formula (a) Or the formula (b) The polyimide resin represented by: (2) 4,4 '-[1,4-phenylenebis (1-methylethylidene)] bisaniline and 4,4'-[1,4-phenylenebis (1-methylethylidene)] bisphenylbistrimellitate Dianhydride or 4,4 '-[1,3-phenylenebis (1-methylethylidene)] bisaniline and 4,4'
-[1,3-phenylenebis (1-methylethylidene)]
A method for producing a polyimide resin, comprising reacting bisphenylbistrimellitate dianhydride.