JP2598537B2 - Polyimide resin composition - Google Patents

Description

The present invention relates to a resin composition for molding.

More specifically, the present invention relates to a polyimide-based molding resin composition having excellent heat resistance, chemical resistance, mechanical strength, and the like and excellent moldability.

[Conventional technology]

Conventionally, in addition to its high heat resistance, polyimide has excellent mechanical strength, dimensional stability, flame retardancy, electrical insulation, etc., so that it has been used in electrical and electronic equipment, aerospace equipment, transportation equipment, etc. It is used in various fields, and is expected to be widely used in fields where heat resistance is required.

Conventionally, various polyimides exhibiting excellent characteristics have been developed.

However, even if it has excellent heat resistance, it does not have a clear glass transition temperature, so if it is used as a molding material, it must be processed using a special method such as sintering. Is excellent, but has a low glass transition temperature, is soluble in halogenated hydrocarbons, and is not satisfactory in terms of heat resistance and solvent resistance.

[Problems to be solved by the invention]

An object of the present invention is to obtain a polyimide resin composition having excellent moldability in addition to excellent characteristics inherent to polyimide.

[Means for solving the problem]

The present inventors have conducted intensive studies in order to solve the above problems, and found that a polyimide resin composition comprising a novel polyimide and a specific amount of polyester is particularly effective for the above purpose, and completed the present invention. .

First, the present inventors have proposed a polyimide having excellent heat resistance, mechanical properties, thermal properties, electrical properties, solvent resistance and the like, and a general formula (I) (In the formula, R is an aliphatic group having 2 or more carbon atoms, a cyclic aliphatic group, a cyclic aliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, an aromatic group is directly or crosslinked. Represents a tetravalent group selected from the group consisting of non-fused polycyclic aromatic groups interconnected by a member.) A resin having a repeating unit represented by the formula: (JP-A-64-243132, JP-A-1-215825, Japanese Patent Application No. 63-31508)
9, 63-320581, 63-334655, etc.).

The above-mentioned polyimide has good thermoplasticity unlike conventionally known polyimides, and can be processed by a melt molding method such as extrusion molding and injection molding.

However, when compared to ordinary engineering plastics represented by polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polysulfone, polyphenylene sulfide, etc., the heat resistance and other properties are far superior, but the molding processability is higher for these resins. Not yet.

An object of the present invention is to provide a polyimide resin composition for molding which is extremely excellent in terms of fluidity during melting without impairing the inherent properties of polyimide.

That is, the present invention provides (1). General formula (I) (Where R is Represents a tetravalent group selected from the group consisting of 9) to 50% by weight of a polyimide consisting of a repeating unit represented by the following formula, and a polyester resin selected from the group consisting of the repeating units represented by the following formulas, or a repeating unit of each of the following groups: A resin composition comprising 0.1 to 50% by weight of a polyester resin comprising a ternary or quaternary copolymer comprising a combination; (In the formula, X represents hydrogen, fluorine, chlorine, bromine or a methyl group.) (In the above formula, those having two carbonyl groups are 2
The carbonyl groups occupy the ortho, meta or para positions with respect to each other and may be a mixture thereof. (2). (3). The resin composition according to the above (1), wherein the polyester is a polyester capable of forming an anisotropic melt phase at a temperature of 420 ° C. or lower; The resin composition according to the above (1), wherein the polyester is an aromatic polyester capable of forming an anisotropic melt phase at a temperature of 420 ° C. or lower.

The production of the polyamide used in the present invention is described in
63-243132, JP-A-1-215825, Japanese Patent Application No. 63-315086, 63
-320581, 63-334655 and the like.

That is, the general formula (II) An aromatic diamine, that is, bis [4-
{4- (4-aminophenoxy) phenoxy} phenyl] sulfone is reacted with one or more tetracarboxylic dianhydrides.

In addition, as long as the good physical properties of the polyimide of the method of the present invention are not impaired, a part of the above diamine may be used in place of the diamine used in other known polyimides.

The tetracarboxylic dianhydride to be reacted with the diamine is represented by the general formula (III) (In the formula, R is the same as described above.) For example, ethylene tetracarboxylic dianhydride, butane tetracarboxylic dianhydride, cyclopentane tetracarboxylic dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, bis (2, 3-dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, 2,2-
Bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, 2,2-bis (3,4-dicarboxyphenyl)-
1,1,1,3,3,3-hexafluoropropane dianhydride, 2,2-
Bis (2,3-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, pyromellitic dianhydride, 3,3 ', 4,4'-benzophenone tetracarboxylic acid Acid dianhydride, 2,2 ', 3,3'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, 2,2 ', 3,3' -Biphenyltetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (2,3-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl)
Sulfone dianhydride, 4,4 '-(p-phenylenedioxy) diphthalic dianhydride, 4,4'-(m-phenylenedioxy) diphthalic dianhydride, 2,3,6,7-naphthalene Tetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,2,3,4-benzenetetracarboxylic Acid dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride These tetracarboxylic dianhydrides are used alone or in combination of two or more.

The reaction method of the diamine and tetracarboxylic dianhydride can be used conventionally known methods without limitation, for example,
Performing in an organic solvent is a preferred method.

As the organic solvent used in this reaction, for example, N, N-
Dimethylformamide, N, N-dimethylacetamide,
N, N-diethylacetamide, N, N-dimethylmethoxyacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N-methylcaprolactam, 1,2-dimethoxyethane, bis (2 -Methoxyethyl) ether, 1,2-bis (2-methoxyethoxy) ethane, bis {2- (2-methoxyethoxy) ethyl} ether, tetrahydrofuran, 1,3-dioxane, 1,4-
Dioxane, pyridine, picoline, dimethyl sulfoxide, dimethyl sulfone, tetramethyl urea, hexamethyl phosphoramide, phenol, m-cresol, p-
Cresol, p-chlorophenol, anisole and the like can be mentioned.

These organic solvents may be used alone or as a mixture of two or more.

The reaction is carried out at a temperature of 0 ° C to 250 ° C, usually 60 ° C or lower.

The reaction pressure is not particularly limited, and the reaction can be carried out at normal pressure.
The reaction time varies depending on the type of tetracarboxylic dianhydride, diamine, solvent used and the reaction temperature.
30 minutes to 24 hours is sufficient.

By such a reaction, a polyamic acid having a repeating unit represented by the following general formula (IV) as a basic skeleton is produced.

(In the formula, R is the same as described above.) The polyamic acid is dehydrated by heating to 100 to 400 ° C. or imidized by using an imidizing agent usually used, for example, triethylamine and acetic anhydride. And the following general formula (I) (Wherein, R is as defined above) as a basic skeleton.

Generally, after the polyamic acid is produced at a low temperature, it is further thermally or chemically imidized.

However, the polyimide can also be obtained by simultaneously performing the polyamic acid generation and the thermal imidization reaction at a temperature of 60 to 250 ° C.

That is, after the tetracarboxylic dianhydride and the diamine are suspended or dissolved in an organic solvent, the reaction is carried out under heating, and the polyamic acid is generated and dehydrated by imidization at the same time. A polyimide having the repeating unit of (1) as a basic skeleton can be obtained.

Also, besides tetracarboxylic dianhydride and diamine,
In order to improve thermal stability and / or processability of the resulting polyamide during processing, aromatic monoamines, aliphatic monoamines, cycloaliphatic monoamines, aromatic dicarboxylic acid monoanhydrides, aliphatic Dicarboxylic acid monoanhydride, the addition of one or more compounds selected from cycloaliphatic dicarboxylic acid monoanhydride during the reaction,
This is a particularly preferred method.

The types of polyester used as a fluidization accelerator in the present invention are as follows.

That is, those obtained by reacting at least one kind of dihydric phenol and / or aliphatic diol and / or alicyclic diol with at least one kind of dicarboxylic acid and / or dicarboxylic acid derivative.

Further, a three-component or more copolymer containing at least one kind of hydroxycarboxylic acid and / or a hydroxycarboxylic acid derivative in addition to the two components, and a polyester as a whole. Further, those obtained by the reaction of at least one kind of hydroxycarboxylic acid and / or hydroxycarboxylic acid derivative are also included.

As specific examples of these, repeating units of the polymer skeleton are shown below.

(Wherein the two carbonyl groups occupy the ortho, meta or para positions with respect to each other and may be a mixture thereof. The same applies to the following formulas.) (X represents hydrogen, fluorine, chlorine, bromine or an alkyl group.) Further, as a polyester as a whole in a copolymer of three or more components, a dihydric phenol or diol residue, a dicarboxylic acid residue, a combination of hydroxycarboxylic acid residues, Is mentioned.

Since many of these polyesters having various degrees of polymerization are commercially available, a polyester having a melt viscosity characteristic suitable for a target blend can be arbitrarily selected on the market.

The molding resin composition of the present invention is the polyimide 99.9 to 50
% Of polyester and 0.1 to 50% by weight of polyester.

The polyimide / polyester resin system of the present invention exhibits a remarkably low melt viscosity in a high temperature range. A good fluidizing effect of polyester is observed even in a small amount, and the lower limit of the composition ratio is 0.1% by weight, preferably 0.5% by weight.

In addition, the chemical resistance, low water absorption, flame retardancy, and mechanical strength of the polyester that forms the anisotropic melt phase belong to a very excellent class among heat-resistant resins, but the anisotropy of mechanical properties There are disadvantages such as too strong, fibrils, and low weld strength.

Further, a so-called amorphous polyester which does not form an anisotropic melt phase is inferior in chemical resistance and has insufficient mechanical strength.

Therefore, if the amount of the polyester in the composition is too large, the original characteristics of the polyimide cannot be maintained, which is not preferable. There is an upper limit to the composition ratio of the polyester,
It is preferably at most 50% by weight.

In mixing and adjusting the composition according to the present invention, it can be produced by a generally known method. For example, the following method is preferable.

The polyimide powder and the polyester powder are pre-kneaded using a mortar, Henschel Kimiser, drum blender, tumbler blender, ball mill ribbon blender, etc. to make a powder.

The polyimide powder is dissolved or suspended in an organic solvent in advance, and the polyester is added to the solution or suspension to be uniformly dispersed. Then, the solvent is removed to obtain a powder.

In an organic solvent solution of polyamic acid, which is a precursor of the polyimide of the present invention, after dissolving or suspending the polyester, heat treatment at 100 to 400 ° C. or chemical imide using a commonly used imidizing agent After that, the solvent is removed to form a powder.

The powdery polyimide resin composition thus obtained can be used for various molding applications as it is, such as injection molding, compression molding, transfer molding, and extrusion molding. It is.

In particular, in mixing and adjusting the composition, it is also a simple and effective method to mix and melt powders, pellets, or powder and pellets.

For the melt blending, devices used for melt-blending ordinary rubbers or plastics, for example, a hot roll, a Banbury mixer, a Brabender, an extruder and the like can be used.

The melting temperature is set to a temperature equal to or higher than a temperature at which the compounding system can be melted and lower than a temperature at which the compounding system starts to thermally decompose. The temperature varies depending on the combination of the type of polyimide and the type of polyester, but is usually 250 to 450 ° C., preferably 300 to 4 ° C.
20 ° C.

As a molding method of the resin composition of the present invention, injection molding or extrusion molding, which is a molding method that forms a uniform molten blend and has high productivity, is preferable. However, other transfer molding, compression molding, and sintering are preferable. There is no problem with applying sintering or the like.

In addition, one or more solid lubricants such as molybdenum disulfide, graphite, boron nitride, lead monoxide, and lead powder can be added to the resin composition of the present invention.

Further, one or more types of reinforcing agents, for example, glass fibers, carbon fibers, aromatic polyamide fibers, potassium titanate fibers, and glass beads can be added.

In addition, with respect to the resin composition of the present invention, as long as the object of the present invention is not impaired, an antioxidant, a heat stabilizer, an ultraviolet absorber, a flame retardant, a flame retardant auxiliary, an antistatic agent, a lubricant, and a coloring agent. One or more ordinary additives such as the above can be added.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples.

The physical properties in the examples were measured by the following methods.

Logarithmic viscosity (η): 0.50 g of polyimide powder in 100 ml of a mixed solvent of p-chlorophenol / phenol (weight ratio = 9/1)
・ Measure after cooling to 35 ° C after measurement ・ Glass transition temperature (Tg), melting point (Tm); DSC (Shimadzu DT-40)
Series, DSC-41M) ・ Tensile strength, elongation at break; ASTM D-638 ・ Izod impact value; ASTM D-258 ・ Heat deformation temperature; ASTM D-648 Synthesis Example 1 (Polyamide) Bis [4--3 -(4-Aminophenoxy) benzoyldiphenyl] ether, pyromellitic dianhydride and phthalic anhydride were used as starting materials to obtain a polyimide powder in accordance with JP-A-1-215825.

Polyimide glass transition temperature is 227 ℃, melting point is 385 ℃,
Logarithmic viscosity was 0.55 dl / g.

Synthesis Examples 2 to 4 (polyimide) In the same manner as in Synthesis Example 1, various polyimides were obtained by combining with various acid dianhydrides and phthalic anhydride.

Table 1 shows the physical properties of the polyimide synthesis raw material and the produced polyimide.

Examples 1 to 4 The polyimide obtained in Synthesis Example 1 and a commercially available aromatic polyester (XYDAR SRT-500-6, trade name of DARTCO) were used for the second step.
After dry blending with various compositions as shown in the table, the mixture was extruded while being melted and kneaded with an extruder (40 mm in diameter; with a screw having a compression ratio of 3.0 / 1.0, processing temperature of 400 to 420 ° C.) to obtain uniform compounded pellets. .

Next, the pellets obtained above were subjected to injection molding at a molding temperature of 400 to 420 ° C. and a mold temperature of 250 ° C. using a normal injection molding machine.
The physical and thermal properties of the moldings were measured.

 The results are shown in Table 2 as Examples 1 to 4.

Comparative Examples 1-2 The physical and thermal properties of the molded products obtained by the same operations as in Examples 1-4 were measured using compositions outside the scope of the present invention.

 The results are shown in Table 2 as Comparative Examples 1 and 2.

Examples 5 to 12 and Comparative Examples 3 to 8 The polyimides and various polyesters obtained in Synthesis Examples 2 to 4 were treated in the same manner as in Examples 1 to 4, and the physical and thermal properties of the molded products were measured.

 The results are shown in Table 2.

However, the molding temperature was appropriately determined depending on the combination of polyimide and polyester.

[Effects of the Invention] According to the method of the present invention, a polyimide resin composition having excellent moldability is provided in addition to the excellent properties inherent to polyimide.

Further, by blending with a polyester capable of forming an anisotropic melt phase, a polymer composition having significantly improved heat distortion temperature is provided.

Claims (3)

(57) [Claims] 1. The compound of the general formula (I) (Where R is Represents a tetravalent group selected from the group consisting of 9) to 50% by weight of a polyimide consisting of a repeating unit represented by the following formula, and a polyester resin selected from the group consisting of the repeating units represented by the following formulas, or a repeating unit of each of the following groups: A resin composition comprising 0.1 to 50% by weight of a polyester resin consisting of a ternary or quaternary copolymer comprising a combination. (In the formula, X represents hydrogen, fluorine, chlorine, bromine or a methyl group.) (In the above formula, those having two carbonyl groups are 2
The carbonyl groups occupy the ortho, meta or para positions with respect to each other and may be a mixture thereof. ) 2. The resin composition according to claim 1, wherein the polyester is capable of forming an anisotropic melt phase at a temperature of 420 ° C. or lower. 3. The resin composition according to claim 1, wherein the polyester is an aromatic polyester capable of forming an anisotropic melt phase at a temperature of 420 ° C. or lower.