JPH03287626A - Production of polyimide composition - Google Patents

Abstract

PURPOSE:To obtain a polyimide composition having a finely dispersed silica and excellent tensile modulus by mixing a polyamic acid with a specified compound in an organic polar solvent and cyclizing the polyamic acid through dehydration. CONSTITUTION:A polyamic acid [e.g. a polyamic acid obtained from bis(4- aminophenyl) ether and pyromellitic anhydride], an alkoxysilane and/or its partial hydrolytic condensate (e.g. tetraethoxysilane) and optionally water are mixed in an organic polar solvent (e.g. dimethylacetamide), and the polyamic acid is cyclized through dehydration.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a polyimide composition useful as a raw material resin for paint, a molding material, etc., and a method for producing the same, and more specifically, a polyimide composition containing extremely finely dispersed silica particles. Polyimide &
[Regarding a paraboloid and its manufacturing method.]

[Conventional technology]

The sol-gel method is a method that utilizes hydrolysis and condensation reactions of metal alkoxides to ultimately produce glass, ceramics, etc. Characteristics of this method include that the initial reaction proceeds under mild conditions and that the temperature required to form the final inorganic material is relatively low. For example, it is known that tetraalkoxysilane generates monozeta silica (SiO□) as shown in the following reaction formula in the presence of water.

Si (OR) a +4 HzO→ Si(OH)4
+4ROH→5iOz +2H20 [Problem to be solved by the invention] The present inventors focused on the characteristics of such a sol-gel method,
With the aim of improving the functionality of materials by dispersing silica components in polymers, we have conducted extensive research into finely dispersing silica components in polyimide, and have arrived at the present invention.

[Means to solve problems]

The present invention is a method for producing a polyimide composition obtained by mixing a polyamic acid, an alkoxysilane and/or a partially hydrolyzed condensate thereof, and a small amount of water as necessary in an organic polar solvent, followed by dehydration and ring closure. .

The polyimide composition of the present invention is manufactured by a method described in the following publications.

Polyamic acid has the following general formula:
That is, a repeating unit having a structural formula (wherein R is a tetravalent group containing at least a divalent carbon atom, and the carbonyl group bonded to the tetravalent group is a repeating unit having the structural formula R' is a divalent group containing at least a divalent carbon atom, and R' is a divalent group containing at least a divalent carbon atom, and no bond is made to the divalent group. It is assumed that each divalent amino group is bonded to a distant carbon atom of the above-mentioned divalent group.)

The polyamic acid can be prepared by a known method, for example, Japanese Patent Publication No. 36-1.
No. 0999, No. 3B-8250 H, N-R'
-NH.

(wherein R' is the same as above) and at least one tetracarboxylic dianhydride having the structural formula % (wherein R is the same as above). , by conducting the reaction in an organic polar solvent under substantially anhydrous conditions while maintaining the temperature during the reaction below 60'C, preferably below 50'C.

The obtained polyamic acid solution is used for producing a poly441 composition as described below. The conversion of boria-acid to polyimide is carried out by thermal or chemical methods. In the case of chemical imidization, a dehydrating agent and an imidization catalyst are used in combination. Polyimide is characterized by repeating units having the following structural formula.

(In the formula, R and R' are the same as above.) Suitable dianhydrides for use in the present invention include pyromellitic dianhydride, 3.3', 4.4'-diphenyltetracarboxylic dianhydride, 3.3'4.4'-Hensephenonetetracarboxylic dianhydride, 2,3,6.7-naphthalenetetracarboxylic dianhydride, 2.2'-bis(3
, 4-dicarboxyphenyl)propanihydride, bis(3゜4-dicarboxyphenyl)ether dianhydride,
These include ethylenetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, and the like.

Diamines suitable for use in the present invention include m-phenylenediamine, P-phenylenediamine, 4.4'-
Diaminodiphenylpropane, 44'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether,
0-tolidine, O dianisidine, l,5-diaminonaphthalene, 4゜4'-cyanodiphenyl sulfide, 4
．． Examples include 4'-diaminodiphenylsulfone.

Solvents useful in synthesizing the polyamic acids used in the present invention are organic polar solvents whose functional groups do not react with diamines or dianhydrides. The organic polar solvent must be inert to the reaction system and be a solvent for the product as well as for at least one of the reactants and preferably for both reactions. Preferred solvents include N, N
-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, tetramethylene sulfone, dimethyl sulfone, pyridine, diethylene glycol dimethyl ether and the like.

Solvents can be used alone or in combination, or with non-solvents such as benzene, toluene, xylene, dioxane, butyrolactone, cyclohexane.

The dehydrating agent and imidization catalyst used in the present invention are not particularly limited, but the following compounds are usually used.

Examples of dehydrating agents include aliphatic and aromatic carboxylic acid anhydrides such as acetic acid, propionic acid, isobutyric acid, benzoic acid, propylbenzoic acid, and toluic acid.

In addition, as an imidization catalyst, pyridine, isoquinoline, 3
．． Examples include tertiary fruits such as 5-lutidine, 4-methylpyridine, and 3-methylpyridine.

The alkoxysilane and/or its partially hydrolyzed condensate used in the present invention is typically represented by general formula (T) or [II).

(R# O),, SiR# 4□ ... [I]
(In the formula, R# is an alkyl group, an aryl group, or an allyl group having 1 to 5 carbon atoms and may be the same or different.

n is 3 or 4) OR' (R″O”)s S i On S i O+r−R”
...[■]R (wherein R# is the same as above or represents a hydrogen atom.

(n is 0 or an integer from 1 to 10) Specific examples of these include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, tetrabutoxysilane, trimethoxymethylsilane, triethoxymethyl Examples include silane, tributoxymethylsilane, tetraphenoxysilane, and partially hydrolyzed polycondensates thereof. These can be used alone or in combination of two or more.

The alkoxysilane and/or its partially hydrolyzed condensate or its organic solution and, if necessary, a small amount of water are added to the polyamic acid solution, and after thorough mixing, the solvent is removed, and if necessary, the mixture is heated and dried.

A small amount of water is added to promote the reaction that produces silica from alkoxysilane or its partially hydrolyzed condensate, but it is not added if the reaction progresses sufficiently due to the water produced in the subsequent imide ring closure or the moisture in the atmosphere. You don't have to.

The solvent for the organic solution of the alkoxysilane and/or its partially hydrolyzed condensate is not particularly limited, but may include organic polar solvents used for the above-mentioned boriadandic acid, such as N,N-dimethylformamide and N.

N-dimethylacetamide, N-methyl-2-pyrrolidone, tetramethylene sulfone, dimethyl sulfone, pyridine, diethylene glycol dimethyl ether, and the like are preferably used.

The above-mentioned mixture is subjected to imide ring closure at the same time as heating and drying, or after drying, heating and imide ring closure, or chemical ring closure to obtain the composition of the present invention. In addition, in the case of chemical ring closure,
The above dehydrating agent and imidization catalyst are further added and imidization is carried out at room temperature or by heating.

In addition, during the production of polyamic acid, that is, during polymerization, alkoxysilane and/or its partially hydrolyzed condensate or its organic solution is added together with the monomer or during polymerization, and alkoxysilane and/or its hydrolyzed After obtaining a boria-dando acid solution containing linear compounds, the solvent is removed,
If necessary, the composition of the present invention may be obtained by performing imide ring closure after addition.

The preferable addition amount of the alkoxysilane and/or its partially hydrolyzed condensate is 1 to 70 parts by weight per 100 parts by weight of polyamic acid, in terms of silica component (SiO2).
More preferably, it is 2 to 60 parts by weight. If it is less than 1 part by weight, the effect of improving the tensile modulus is small, and if it exceeds 70 parts by weight, although the tensile modulus is improved, it becomes brittle and only products with significantly inferior commercial value can be obtained.

Further, the amount of water added as necessary is usually 0 to 200 parts by weight per 100 parts by weight of polyamic acid.

If the amount is too large, the polyamic acid will be hydrolyzed and the physical properties of the polyimide composition will deteriorate, which is not preferable.

The composition of the present invention can also be used by adding well-known additives such as antioxidants, heat stabilizers, ultraviolet absorbers, colorants, etc.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to examples.
The present invention is not limited to the examples unless it exceeds the gist thereof.

Examples 1-6, Comparative Examples 1-2 Bis(4-aminophenyl) ether, 4.0 g (20
mmof) in 80mj2 of dimethylacetamide (hereinafter abbreviated as DMAc), and pyromellitic anhydride 4.
36 g (20 mmof) was added and stirred overnight to synthesize polyamic acid. To 10 g of this DMAc solution of polyamic acid, 1 mf of water and tetraethoxysilane in the amount shown in Table 1 were added, stirred until the solution became uniform, and cast on a glass plate.

After drying this in an oven at 60°C overnight, it was peeled off from the glass plate. Next, after setting it in a fixed frame, it was heat-treated at 270 ° C. for 3 hours under a nitrogen stream to prepare a polyimide composition (approximately 25 μm thick film) containing 5i02 compounds.
It was created.

The characteristic values of the film are shown in Table 1.

Example 7 Bis(4-aminophenyl)ether 12.0 g (6
0 mmol), 3.3', 4.4'-biphenyltetracarboxylic dianhydride 17.7 g (60 mmol)
) and DMAc 290mj! A polyamic acid solution was obtained in the same manner as in Example 1 except that . 3 mj2 of a partially hydrolyzed condensate of tetramethoxysilane was added to 10 g of this polyamide solution, and a polyimide composition (film about 25 μm thick) was prepared in the same manner as in Example 1. The results are shown in Table 1.

[Effects of the Invention] The polyimide composition of the present invention is a polyamide Mi base material with improved various physical properties, especially 9 tension modulus, and is very useful as a raw material resin for paints, a molding material, etc.

Claims (1)

[Claims] (1) A method for producing a polyimide composition, which comprises mixing a polyamic acid, an alkoxysilane and/or a partially hydrolyzed condensate thereof, and optionally a small amount of water in an organic polar solvent, followed by dehydration and ring closure.