JPS6038464A - Polyether-imide resin composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. having high heat resistance, rigidity and strength, low mold shrinkage factor and good mold release characteristics, by blending a reinforcing fiber or an inorg. filler with a polyether-imide resin and further adding a specified quantity of a fluororesin thereto. CONSTITUTION:The titled compsn. is obtd. by blending 10-70wt% reinforcing fiber (e.g. glass fiber or carbon fiber) or inorg. filler (e.g. talc or CaCO3) with 20-80wt% polyether-imide and further adding 0.5-20wt% fluororesin (e.g. tetrafluoroethylene resin) thereto. When the reinforcing fiber or the filler is blended with the polyether-imide, heat resistance and rigidity are improved and mold shrinkage factor is reduced depending on the quantity of the reinforcing fiber or the filler. However, a problem is caused that mold release characteristics during injection molding are deteriorated. By using the fluororesin, the mold release properties can be improved without detriment to the above characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polyetherimide resin composition that exhibits high heat resistance, excellent mechanical properties, low mold shrinkage and good mold release properties.

Polyetherimide is attracting attention as an engineering plastic with excellent heat resistance, strength, rigidity, flame retardance, and chemical resistance, especially in applications such as electrical parts and automobile parts.

However, in this application (frame flammability, which is a characteristic of the resin),
Along with the technological progress in this field, there is a demand for materials that have even higher heat resistance, rigidity, and dimensional accuracy (low mold shrinkage) while maintaining chemical resistance, electrical properties, and the like.

Generally, fibrous reinforcing materials such as glass II4 fibers and carbon fibers, silica, talc, calcium carbonate, magnesium carbonate, calcium sulfite, aluminum hydroxide, mica, etc.
In addition, heat resistance, heat resistance,
It is known that rigidity and molding shrinkage rate are improved.

Even in polyetherimide resin, when the above-mentioned reinforcing materials and fillers are blended, heat resistance and rigidity can be improved and molding shrinkage rate can be reduced depending on the strength of the reinforcement. The molding shrinkage rate decreases as the amount of the reinforcing material or filler increases, and the mold fidelity in injection molding becomes better, but as the molding shrinkage rate decreases, the mold releasability during injection molding becomes poorer. However, it becomes extremely difficult to remove the molded product from the mold.

Therefore, excessive stress is applied when ejecting the molded product, and
Distortion remains in the molded product, causing problems such as stress cracks, deformation during ejection, and even breakage.

Therefore, although there is a great need for a resin composition with low molding shrinkage, good moldability, and good dimensional accuracy, it is usually used to the extent that no problem occurs in the mu properties from the mold. The actual situation is that the amount of reinforcing material and filler added is limited in order to achieve a molding shrinkage rate of .

In view of the above situation, the present inventor conducted extensive research and found that heat resistance and rigidity can be improved by blending a resinous reinforcing material or an inorganic filler with polyetherimide resin, and further adding a specific amount of fluororesin. It has been discovered that it is possible to obtain a composition that has high strength, good strength, low mold shrinkage, and good moldability, and has arrived at the present invention.

The present invention uses polyetherimide 20 = 80 wt%, m
This is a polyetherimide plum fat composition characterized by comprising 10 to 70 wt% of a male reinforcing material or inorganic filler and 0.5 to 20 wt% of a fluororesin.

The polyetherimide used in the present invention has the general formula (where,
Holes are divalent aromatic organic groups carrying 6 to 30 carbon atoms; It is a divalent organic group selected from chain-terminated polydiorganosiloxane groups. ) is a polymer represented by

Here, R is for example Examples include sites.

A particularly typical polyetherimide is a polymer represented by the general formula, which is commercially available from General Electric Company 1 in the United States with a curvature of 11LTElkl. Part 1: Is the way you spend your time characteristic 11? ,+57
-Disclosed in the February 987 bulletin, etc.

The S fibrous reinforcement used as the hζ component of the main coating composition is glass fiber, carbon-filled scarlet, aromatic group polyamide pine fiber, silicon carbide fiber, silicon nitride fiber, alumina frame navy blue, potassium titanate, etc. Fibrous reinforcing materials, such as fibers and mineral fibers, are generally used to improve the heat resistance, strength, rigidity, etc. of resins.

Inorganic fillers used as components of the composition of the present invention include talc, calcium carbonate, magnesium carbonate, calcium sulfite, aluminum hydroxide, mica, molybdenum disulfide, wollastonite, graphite, white titanium, glass beads, Zirconia, silica, etc. are applied.

The fibrous reinforcing material or inorganic filler can usually be used without treatment, but in order to have an affinity with polyetherimide, it may be added with a silane coupling agent such as aminosilane or epoxysilane, chromic chloride, or other materials depending on the purpose. surface treatment agents can be used.

The fluororesin used as a component of the composition of the present invention is:
Synthetic polymers containing a fluorine atom (CF) in the molecule, examples of which include tetrafluoroethylene resin, tetrafluoroethylene perfluoroalkyl vinyl ether copolymer (fat, tetrafluoroethylene 1 Examples include hexafluoropropylene copolymer resin, tetrafluoroethylene-ethylene copolymer resin, trifluorochloroethylene resin, and vinylidene fluoride resin.

The melting point of the fluororesin (polytetrafluoroethylene) is about 880°C, but it has a high melt viscosity and does not flow even above the melting point. Therefore, the dispersion state in the composition is It is preferable because it does not easily change depending on processing conditions, and the bamboo properties, mechanical strength, and mold releasability during injection molding of the composition do not change.

The compound is polyetherimide 20~8Qsv
t%, fibrous reinforcing phase or inorganic filler lO~7Q
wtl, fluororesin 0.5-2Q wtl (total amount of fibrous reinforcing phase or inorganic filler and fluororesin:
A mixture of 20 to 80 wL of the total resin composition is effective.

That is, when the total amount of the reinforcing phase or the filler and the fluororesin in the resin composition exceeds 3 Q wt and the amount of polyetherimide is less than 2 Q wt, the mixing is insufficient; A uniform pA composition cannot be obtained, the fluidity of the resin composition becomes dull, and molding becomes difficult. The total p of the reinforcing material or the filler and the fluororesin is 2owtw.
, H is satisfied, the molding shrinkage rate reducing effect is sufficient. Alternatively, if the amount of the filler is less than 1Qwt, the effect of reducing the molding shrinkage rate is insufficient;
If it is less than wt%, mold releasability during injection molding etc. will not be sufficient.

Also, the reinforcing material is 7 (1wt9B
If it exceeds this amount, the mixing will be insufficient, the compounding process will be difficult, and a uniform composition will not be obtained. If the amount of fluororesin exceeds 2 gwt%, the strength of the obtained molded product will decrease significantly, which is not preferable.

The means of blending the composition of the present invention is not particularly limited. polyetherimide, the fibrous reinforcing material or the inorganic filler,
It is possible to feed each fluororesin separately to the melt mixer, and these raw materials are premixed in advance using a mortar, Henschel mixer, ball mill, ribbon printer, etc. and then fed to the melt mixer. You can also do that.

The composition of the present invention may contain antioxidants, heat stabilizers, ultraviolet absorbers, lubricants, mold release agents, colorants such as dyes and pigments, flame retardants, Ordinary additives such as flame retardant aids, antistatic agents, etc. can be added in quantities of 1 or more.

In addition, other thermoplastic resins (e.g. polyethylene polypropylene, polyamide, polycarbonate, polyester carbonate, polyethylene terephthalate l/-l-
, polybutylene terephthalate, polysulfone, polyethersulfone, modified polyphenylene oquinide, acrylonitrile-styrene-butadiene resin (A13S tree 1] 1), polyphenylene sulfide resin, etc.), thermosetting resins (e.g., phenolic resin, epoxy resin, etc.) can be mixed according to the purpose.

Hereinafter, the present invention will be specifically explained with reference to examples, which are merely illustrative of preferred embodiments and are not limited to the compositions shown in the examples. Polyetherimide (GE company 7~IJLT) represented by the formula
EM” 1000), auralastonite (NYAD-(J1CaSi03 sword-shaped) manufactured by Nagashio Sangyo), and tetrafluoroethylene tree BF1 (Full 1゛L169 manufactured by Jul)
were mixed with the composition shown in Table 1, melt-kneaded using a twin-screw extruder (Ikegai Tetsujo Jl!! PCM-80) at a temperature of 840°C, and the strands were water-cooled and cut. Get a beret.

The obtained pellets were injection molded (Sumitomo-Nestal 47/
28 injection molding machine, cylinder temperature 860℃, mold temperature 1
80° C.) to form a bending test piece. After opening the mold, the resistance when ejecting the molded product using an ejector turbine was measured by opening a strain cage type pressure sensor.

Further, using the obtained bending test piece, bending strength, bending elastic modulus, heat deformation temperature, and molding shrinkage rate were measured.

Bending strength is A8TM ])-790, heat distortion temperature is AC
Measured in accordance with T Todoro t D-648 (18,6 Kf/c = ). The results are shown in Table 1.

Comparative Examples 1 to 5 The polyetherimide used in Examples 1 to 5, wollastonite, and tetrafluoroethylene resin were combined in the proportions shown in Table 1, and the same processing as in Examples 1 to 5 was performed. , the physical properties were measured.

The results are shown in Table @1.

The composition of the present invention has improved thermal properties and rigidity (modulus of elasticity) of polyetherimide, has high strength, and has low moldability 11V, shrinkage rate, and good heat moldability (Example 1). ~5).

In addition, in compositions other than the composition of the present invention, the improvement in molding shrinkage rate was not sufficient (Comparative Example 2), the strength decreased significantly (Comparative Example 4), and the mold releasability was insufficient. (Comparative Example 5), etc., do not have the desired good characteristics.

Claims (1)

[Claims] A polyetherimide resin composition comprising 20 to 80 wt% of polyetherimide or inorganic filled @lO to 70% of polyetherimide and 0.5 to 2 Q of fluororesin.