KR940005650B1 - Polyimide resin composition - Google Patents

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Description

Polyimide Resin Composition

The present invention relates to a molding resin composition comprising a polyimide resin as a main component, and in particular, the present invention consists of a polyimide resin and a thermotropic liquid crystal polymer, and has excellent heat resistance, chemical resistance, mechanical strength, and molding processability. It relates to a composition.

Conventionally, since polyimide has excellent heat resistance, excellent mechanical strength and dimensional stability, and has flame retardancy and electrical insulation, it has been used in the fields of electrical, electronic parts, space and aviation members, transportation equipment, and the like. It is anticipated that the use of polyimide will be expanded to the required area, and various polyimides showing excellent characteristics have been developed.

Although polyimide has excellent heat resistance, when polyimide is used as a molding material, a means such as sintering molding is generally required, and in many cases, processing under high temperature and high pressure may be performed even if the polyimide is thermoplastic and can be melt-molded. Processing is required. When the polyimide is treated under such high temperatures and pressures, the polyimide is thermally deteriorated or oxidized in spite of its excellent heat resistance, thereby reducing the mechanical strength, making it difficult to form thin articles.

Some types of polyimide have a low crystallization rate in the processing step, so that the molded product is obtained in an amorphous state, and even if heat treatment is performed to improve the crystallinity of the polyimide, the dimensional change resulting from the crystallization process may be reduced. The application is strictly limited in the areas of precise parts.

On the other hand, even though the processability is improved, the glass transition temperature of the polyimide is low and soluble in halogenated hydrocarbons, that is, the polyimide has a decrease in performance in heat resistance and chemical resistance. Therefore, the polyimide that has been proposed conventionally has both the above advantages and disadvantages, and therefore, it is desired to improve this.

The inventors of the general formula (I):

(Wherein X is a direct bond, a divalent hydrocarbon group having 1 to 10 carbon atoms, isopropyl hexafluoride group, a carbonyl group, a thio group or a sulfonyl group, and Y ₁ , Y ₂ , Y ₃ and Y ₄ are each a hydrogen or a lower alkyl group). , Lower alkoxy group, chlorine or bromine, R is a tetravalent aromatic group selected from the group consisting of aliphatic group having 2 or more carbon atoms, cycloaliphatic group, monocyclic aromatic group, condensed polyaromatic group or polycyclic aromatic group connected to each other through a direct or crosslinking member Qi.)

Novel polyimide resins having repeating units represented by (Japanese Patent Laid-Open Nos. 61-143478, 62-68817, 62-86021, 62-235381 and 63-128025) were found.

The polyimide resin found above is a novel heat resistant resin excellent in various properties such as mechanical strength, thermal properties, electrical properties, and solvent resistance, in addition to their basic heat resistance.

Polyimide resins are superior in heat resistance, mechanical strength and electrical properties as compared with conventional engineering plastics represented by polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polysulfone and polyphenylene sulfide. Therefore, in addition to such substantial superior properties, polyimide resins having excellent processability are expected to be used in fields that cannot be satisfied with conventional engineering plastics.

It is an object of the present invention to provide a polyimide-based molded resin composition having excellent flowability in the molten state in addition to substantial excellent properties.

Another object of the present invention is to provide a polyimide resin composition having high crystallization rate and improved dimensional stability of a molded article in a heat treatment step.

As a result of extensive research to achieve these objects, the present inventors have found that a polyimide composition composed of a novel polyimide and a thermotropic liquid crystalline polymer is particularly effective for achieving the above object, thereby completing the present invention.

One aspect of the invention is the general formula (I)

(Wherein X, Y ₁ , Y ₂ , Y ₃ , Y ₄ and R are the same as above), preferably represented by general formula (II);

Wherein X and R are the same as above.

It relates to a resin composition consisting of 99.9 to 50% by weight of polyimide and 0.1 to 50% by weight of thermotropic liquid crystal polymer having a repeating unit represented by.

In the resin composition of the present invention, thermotropic liquid crystalline polymers are represented by general formulas (V), (VI) and (VII);

It is most preferable that it is a thermotropic liquid crystalline polymer obtained by superposing | polymerizing so that a polyester bond may be formed in the basic structural unit of (s).

The resin composition of the present invention significantly improves the molding process without impairing the excellent properties of the polyimide resin, and improves the dimensional stability of the molded article during the heat treatment (annealing) step.

The polyimide used for this invention is represented by the said general formula (I).

Polyimide is a general formula (VIII),

Etherdiamine represented by the formula (X, Y ₁ , Y ₂ , Y ₃ and Y ₄ are the same as above), preferably of the general formula (IX)

In the formula, X may be prepared by reacting the etherdiamine represented by the above with at least one tetracarboxylic dianhydride.

That is, the etherdiamine can be prepared by reacting with tetracarboxylic dianhydride in a solvent and then thermally or chemically imidating the polyimide acid obtained.

The reaction temperature is usually 250 ° C. or lower, and the reaction pressure is not particularly limited and it is sufficient to carry out the reaction at atmospheric pressure.

The reaction time varies depending on the tetracarboxylic dianhydride used, the type of solvent and the reaction temperature.

The reaction is usually carried out for a sufficient time for the polyimide acid intermediate to form completely, up to 24 hours, and in some cases up to 1 hour.

The above reaction forms a polyamic acid corresponding to the repeating structural unit of formula (I), and the polyamic acid is subsequently thermally dehydrated at 100 to 400 ° C. or chemically imidized using a conventional imidizing agent. The polyimide having a repeating structural unit of formula (I) is obtained by dehydration.

In addition, the polyimide may be produced by simultaneously forming the polyamic acid and performing the heat-imidization reaction.

The diamine compound used for manufacture of the said polyimide used as a main component in the composition of this invention is represented by said general formula (VIII).

Examples of the diamine compound include bis [4- (3-aminophenoxy) phenyl] methane, 1,1-bis [4- (3-aminophenoxy) phenyl] ethane, 1,2-bis [4- ( 3-aminophenoxy) phenyl] ethane, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2- [4- (3-aminophenoxy) phenyl] -2- [4- ( 3-aminophenoxy) -3-methylphenyl] propane, 2,2-bis [4- (3-aminophenoxy) -3-methylphenyl] propane, 2- [4- (3-aminophenoxy) phenyl]- 2- [4- (3-aminophenoxy) -3,5-dimethylphenyl] propane, 2,2-bis [4- (3-aminophenoxy-3,5-dimethylphenyl] propane, 2,2- Bis [4- (3-aminophenoxy) phenyl] butane, 2,2-bis [4- (3-aminophenoxy) phenyl] -1,1,1,3,3,3, -hexafluoropropane, 4,4-bis (3-aminophenoxy) biphenyl, 4,4'-bis (3-aminophenoxy) -3-methylbiphenyl, 4,4'-bis (3-aminophenoxy) -3 , 3'-dimethylbiphenyl, 4,4'-bis (3-aminophenoxy) -3,5-dimethylbiphenyl, 4,4'-bis (3-aminophenoxy) -3,3 ', 5 , 5'-tetramethylbiphenyl, 4,4'-bis (3-aminophenoxy) -3,3'-dichlorobiphenyl, 4,4'-bis (3-aminophenoxy) -3,5-dichlorobiphenyl, 4,4'-bis (3-aminophenoxy) -3,3 ' , 5,5'-tetrachlorobiphenyl, 4,4'-bis (3-aminophenoxy) -3,3'-dibromobiphenyl, 4,4'-bis (3-aminophenoxy) -3 , 5-dibromophenyl, 4,4'-bis (3-aminophenoxy) -3,3 ', 5,5'-tetrabromobiphenyl, bis [4- (3-aminophenoxy) phenyl] Ketone, bis [4- (3-aminophenoxy) phenyl] sulfide, bis [4- (3-aminophenoxy) -3-methoxyphenyl] sulfide, [4-3-aminophenoxy) phenyl [ 4- (3-aminophenoxy) -3,5-dimethoxyphenyl] sulfide, bis [4- (3-aminophenoxy) -3,5-dimethoxyphenyl] sulfide, bis [4- (3 -Aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ether, 1,4-bis [4- (3- Aminophenoxy) phenoxy] benzene, 1,4-bis [4- (4-aminophenoxy) phenoxy] benzene, 1,4-bis [4- (3-aminophenoxy) benzoyl] benzene, 1, 3-bis [4- (3-amino Oxy) benzoyl] benzene, bis [4- {4- (4-aminophenoxy) phenoxy} phenyl] sulfone, and bis [4- {4- (4-aminophenoxy) phenoxy} phenyl] ketone The diamine compound can be used alone or in combination of these.

Tetracarboxylic dianhydride which is another raw material for producing the polyimide of general formula (I) is represented by general formula (X).

Wherein R is as defined above.

In tetracarboxylic dianhydride represented by general formula (X), R is represented by general formula (XI),

(Wherein X ₂ is directly connected, -O-, -S-, -SO _2- , -CH _2- , -CO-,

It is preferable that it is a tetravalent group represented by.

Therefore, in the polyimide of general formula (I), it is preferable that R is represented by general formula (XI).

Examples of tetracarboxylic dianhydrides used as raw materials in the production of polyimides include ethylene tetracarboxylic dianhydride, butanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, pyromellitic dianhydride, 3,3 '. , 4,4'-benzophenonetetracarboxylic dianhydride, 2,2 ', 3,3'-benzophenone tetracarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, 2,2 ', 3,3'-biphenyltetracarboxylic acid dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, Bis [3,4-dicarboxyphenyl] ether dianhydride, bis [3,4-dicarboxyphenyl] sulfone dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, bis (2, 3-dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, 4- [4- (3,4-dicarboxyphenoxy) phenoxy] phthalic acid dianhydride, 2,3, 6,7-I Talenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3, 4,9,10-phenylenetetracarboxylic acid dianhydride, 2,3,6,7-anthracenetetracarboxylic acid dianhydride, and 1,2,7,8-phenanthrenetetracarboxylic acid dianhydride.

Tetracarboxylic dianhydride can be used individually or in mixture.

The polyimide used in the composition of the present invention is prepared using the above ether diamine as a raw material. Moreover, the polyimide manufactured using the other diamine simultaneously can be used for the composition of this invention, as long as the outstanding characteristic of a polyimide is not impaired.

Examples of diamines that can be used simultaneously are m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, bis (3-aminophenyl) ether, (3- Aminophenyl) (4-aminophenyl) ether, bis (4-aminophenyl) ether, bis (3-aminophenyl) sulfide, (3-aminophenyl) (4-aminophenyl) sulfide, bis (4-amino Phenyl) sulfide, bis (3-aminophenyl) sulfoxide, (3-aminophenyl) (4-aminophenyl) sulfoxide, bis (4-aminophenyl) sulfoxide, bis (3-aminophenyl) sulfone, ( 3-aminophenyl) (4-aminophenyl) sulfone, bis (4-aminophenyl) sulfone, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzo Phenone, bis [4- (4-aminophenoxy) phenyl] methane, 1,1-bis [4- (4-aminophenoxy) phenyl] ethane, 1,2-bis [4- (4-aminophenoxy ) Phenyl] ethane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] butane, 2,2- Bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis ( 4-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) ratio Phenyl, bis [4- (4-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenoxy) phenyl] sulfide, bis [4- (4-aminophenoxy) phenyl] sulfoxide, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ether, 1,4-bis [ 4- (4-aminophenoxy) benzyl] benzene and 1,4-bis [4- (4-aminophenoxy) benzyl] benzene.

The resin composition of the present invention can be obtained by kneading the polyimide resin with the following components.

That is, in the composition of the present invention, the component kneaded with the polyimide is a thermotropic liquid crystal polymer. The polyester resin, which is such a thermotropic liquid crystal polymer, is most preferably obtained by carrying out polymerization so that a polyester bond is formed by the basic structural units of the general formulas (V), (VI) and (VII).

The molded resin composition of the present invention is prepared by kneading 99.9 to 50% by weight of the polyimide resin and 0.1 to 50% by weight of the thermotropic liquid crystal polymer.

The composition of the present invention can be prepared by a generally known method, for example as follows.

(1) A method for producing a powder by kneading a polyimide resin powder and a thermotropic liquid crystal polymer in a mortar, Henschel mixer, drum blender, tumbler, bowl mill, and ribbon blender.

(2) A method of preparing a powder by adding a thermotropic liquid crystal polymer to a solution or suspension obtained by dissolving or suspending a polyimide resin powder in an organic solvent in advance and uniformly dispersing it to remove the solvent.

③ In the present invention, the thermotropic liquid crystal polymer is suspended in an organic solvent solution of polyamic acid which is a precursor of polyimide and heat treated at 100 to 400 ° C. or chemically imidized using a conventional imidizing agent, and then the solvent is removed. Thereby producing a powder.

The powdered polyimide resin composition thus obtained can be used for various molding methods, for example, injection molding, compression molding, transfer molding, and the like, and it is more preferable to perform molding after melting of each composition component.

In the preparation of the melt-mixed composition, it is a simple and efficient method to mix-mould powders, pellets or powders and pellets.

Melt mixing can be performed, for example, by using a conventional rubber or plastic melt kneading apparatus such as hot roll, Banbury mix, brabender and extruder.

Melt mixing is carried out in the formulation from the melting temperature to the decomposition start temperature range, usually 250 to 420 ° C, preferably 300 to 400 ° C.

As a method of molding the resin composition of the present invention, injection molding or extrusion molding, which is a method of forming a uniformly melted blend and having high productivity, is suitable. In addition, other molding methods such as transfer molding, compression molding and sintering molding can be used without any problem.

In the present invention, one or more additives may be added to the composition if necessary.

Examples of the additive that can be used include fillers such as calcium carbonate, mica, glass beads, graphite, and molybdenum disulfide; Fiber reinforcing materials such as glass fiber, carbon fiber, ceramic fiber, aramid fiber, potassium titanate fiber and metal fiber; Release agent; Stabilizer; Coloring agent; Thermoplastic resins such as polyphenylene sulfide, polyetherimide, polyether sulfone, and polyether ether ketone; And thermosetting resins such as phenol resins, epoxy resins, silicone resins and polyamideimide resins.

Hereinafter, the present invention will be described in detail through examples and comparative examples.

In Examples and Comparative Examples, physical properties are measured by the following method.

○ Intrinsic Viscosity:

0.5 g of polyimide powder was dissolved in 100 ml of a solvent mixture composed of p-chlorophenol / phenol (weight ratio: 9/1), cooled to 35 ° C, and measured.

○ Tensile Strength:

Measured according to ASTM D-638 using a non-welded tensile test specimen and a tensile test specimen welded to the center of the parallel.

○ Elongation at break:

Measured according to ASTM-D638,

○ Izod collision strength:

Measured according to ASTM D-258

○ Melt Flow Rate (MFR):

Measured according to JIS K-7210 at 400 ° C and a load of 1.05 kg.

○ heat shrinkage

According to ASTM D-638, heat treatment is performed on the tensile test specimen under the conditions described below, and the dimensional change in the longitudinal direction in the specimen is measured before and after the heat treatment, respectively.

○ Heat Deflection Temperature (HDT)

Measured according to ASTM D-648

○ heat treatment

Heat treatment is performed in three stages of 150 ° C. × 20 hours → 260 ° C. × 20 hours → 300 ° C. × 2 hours.

○ Crystallization fever peak temperature (Tc)

The crystallization exotherm peak temperature (T _C1), and the crystallization heat generation peak temperature (T _C2) under from 400 ℃ 10 ℃ / min under a temperature descent rate of temperature rise of 10 ℃ / min from room temperature is measured with a differential scanning calorimeter.

○ Linear thermal expansion coefficient

Using a non-welded tensile test piece, the linear coefficient of thermal expansion between 25 ° C. and 200 ° C. in the flow direction (MD) and at right angles (TD) is measured with a thermal expansion meter.

○ Flexural Strength:

Measured according to ASTM D-790

○ bending rate

Measured according to ASTM D-790

○ Sintering Distortion:

The injection molded plate (75 × 100 × 2 mm) is heat treated to measure the change in the sinter distortion height in the long direction between before and after heat treatment.

[Examples 1-5 and Comparative Examples 1, 2]

Polyimide having an intrinsic viscosity of 0.45 dl / g is prepared from 4,4-bis (3-aminophenoxy) biphenyl and pyromellitic dianhydride. The obtained polyimide is dry mixed with the thermotropic liquid crystal polymer Xydar SRT-50 (trade name, DARTCO Co. Ltd) in the composition shown in Table 1. The obtained mixture is melt kneaded in a compressor at a cylinder temperature of 400 DEG C, extruded and cut into pellets. .

The pellet is injection molded at a cylinder temperature of 380 to 410 ° C., a molding temperature of 190 ° C. and an injection pressure of 500 kg / cm ² to obtain a tensile test sample. The tensile test specimen welded to the center of the parallel part is injection molded under the same conditions. Tensile strength test results are shown in Table 1.

The spiral flow length at a cylinder temperature of 400 ° C., a molding temperature of 180 ° C., an injection pressure of 1000 kg / cm ^2, and a cavity thickness of 1 mm was measured, and the results are shown in Table 1.

Thermal shrinkage, linear expansion coefficient, and peak temperature (Tc) of crystallization heat were measured using an unwelded injection-molded specimen and the results are shown in Table 1. The TD / MD ratio of the linear thermal expansion coefficient is assumed to be anisotropic and the results are shown in Table 1.

Example 6

The same process as in Example 2 was carried out except that ECONOL E-6000 '(trade name, Sumitomo Chemical Co. Ltd.) was used as the thermotropic liquid crystal polymer. The results are shown in Table 1.

Example 7

The same process as in Example 4 was carried out except that ECONOL E-6000 (trade name, Sumitomo Chemical Co. Ltd.) was used as the thermotropic liquid crystal polymer.

Comparative Example 3

The same process as in Comparative Example 1 is carried out in addition to using ECONOL E-6000 (trade name, Sumitomo Chemical Co. Ltd.) as the thermotropic liquid crystal polymer. The results are shown in Table 1.

Example 8

The same process as in Example 3 was carried out except that polyimide having an intrinsic viscosity of 0.46 dl / g prepared from bis [4- (3-aminophenoxy) phenyl] sulfide and pyromellitic dianhydride was used. The results are shown in Table 1.

[Comparative Example 4]

The same process as in Comparative Example 1 is carried out except that a polyimide having an intrinsic viscosity of 0.46 dl / g prepared from bis [4- (3-aminophenoxy) phenyl] sulfide and pyromellitic dianhydride is used. The results are shown in Table 1.

[Comparative Example 5]

The same process as in Comparative Example 2 is carried out except that a polyimide having an intrinsic viscosity of 0.46 dl / g prepared from bis [4- (3-aminophenoxy) phenyl] sulfide and pyromellitic dianhydride is used. The results are shown in Table 1.

Example 9

Polyimide having an intrinsic viscosity of 0.45 dl / g prepared from 2,2-bis [4- (3-aminophenoxy) phenyl] propane and 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride The same process as in Example 3 is carried out except for use. The results are shown in Table 1.

Comparative Example 6

Polyimide having an intrinsic viscosity of 0.45 dl / g prepared from 2,2-bis [4- (3-aminophenoxy) phenyl] propane and 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride The same process as in Comparative Example 1 is carried out in addition to use. The results are shown in Table 1.

Comparative Example 7

Polyimide having an intrinsic viscosity of 0.45 dl / g prepared from 2,2-bis [4- (3-aminophenoxy) phenyl] propane and 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride In addition to use, the same steps as in Comparative Example 2 are performed. The results are shown in Table 1.

TABLE 1

Claims (1)

Formula (I) (Wherein, X is a direct connection, divalent hydrocarbon having 1 to 10 carbon atoms, isopropyl hexafluoride group, carbonyl group, thio group or sulfonyl group, Y ₁ , Y ₂ , Y ₃ and Y ₄ are each hydrogen atom, lower alkyl group) , A lower alkoxy group, a chlorine atom or a bromine atom, R is a tetravalent aromatic group selected from an aliphatic group having 2 or more carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, a condensed polyaromatic group, or a polycyclic aromatic group connected to each other through a direct or bridged member Qi.) 99.9 to 50% by weight of polyimide having repeating units represented by the formulas (V), (VI) and (VII), Resin composition consisting of 50 ~ 0.1% by weight of the thermotropic liquid crystal polymer having a basic structural unit represented by.