JP2796543B2 - Thermoplastic polyimide resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a thermoplastic polyimide resin composition having excellent characteristics as an engineering plastic material.

[Conventional technology]

Conventionally, thermoplastic polyimide resin is heat-resistant, flame-retardant,
As an engineering plastic material excellent in chemical resistance and the like, it has been used particularly in the fields of electric and electronic devices, vehicle devices such as automobiles, and the like. However, this resin is not satisfactory in non-adhesiveness, sliding characteristics, and high-temperature rigidity, and cannot be applied in the field of office equipment such as a copying machine in which these characteristics are required. Also,
For thermoplastic polyimide resin, polytetrafluoroethylene, polytetrafluoroethylene-hexafluoropropylene copolymer, polytetrafluoroethylene-
Attempts have been made to improve non-adhesion and sliding properties by adding a fluororesin such as a perfluoropropylene copolymer. In this case, in order to impart sufficient non-adhesiveness and sliding characteristics to the resin composition, it is necessary to add a considerably large amount of the above-mentioned fluororesin. Cannot maintain the mechanical strength to be provided, in particular, the high-temperature rigidity. It is also conceivable to use a fibrous reinforcing agent such as glass fiber or carbon fiber in combination to compensate for this drawback, but in order to maintain the above-mentioned sufficient strength, it is necessary to add a considerable amount of these. In this case, anisotropy or warpage based on the orientation of the fibrous reinforcing agent is generated, and the mating material is easily damaged during sliding, and a sufficient lubricity cannot be obtained.

[Problems to be solved by the invention]

As described above, in the conventional technology, in addition to excellent heat resistance, flame retardancy, chemical resistance, etc., it is excellent in non-adhesion, has high mechanical strength at high temperatures, and has excellent sliding characteristics. There is a problem that a resin composition has not been obtained, and solving these problems has been an issue.

[Means for solving the problem]

To solve the above problem, the present invention provides a compound of formula (I) With respect to 100 parts by weight of a thermoplastic polyimide resin consisting of a repeating unit represented by 3,10,90 parts by weight of a copolymer of 3,3,3-trifluoro-2-trifluoromethylpropene and 1,1-difluoroethylene. In this method, a part is added to obtain a polyimide resin composition. The details are described below.

First, the thermoplastic polyimide resin used in the present invention is represented by the formula (I), and the production method thereof is not particularly limited. Can be obtained by reacting 4,4-bis (3-aminophenoxy) biphenyl represented by the following formula with pyromellitic dianhydride to produce a polyimide acid, and dehydrating and cyclizing the polyimide acid.

Such, the melt viscosity of the thermoplastic polyimide resin,
Depending on the shape at the time of molding and the application in which it is used, it may be an optimal value, preferably about 0.35 to 0.80 dl / g, 0.45 to
About 0.55 dl / g is particularly preferable.

Next, the copolymer of 3,3,3-trifluoro-2-trifluoromethylpropene and 1,1-difluoroethylene used in the present invention has the formula (II) The repeating unit represented by or alone or together with the repeating unit represented by CH ₂ CF _{2 is used} in a proportion of less than 20 monomer% so that the inherent properties of the copolymer of the formula (II) are not lost. It is a coexisting copolymer. A method for producing a copolymer of 3,3,3-trifluoro-2-trifluoromethylpropene and 1,1-difluoroethylene is disclosed in
As disclosed in JP-A-32785 and the like, 3,3,3-trifluoro-2-trifluoromethylpropene and 1,1-
It is produced by copolymerizing difluoroethylene with a predetermined solvent, in which case the molar ratio of the two substances is in the range of 1: 9 to 9: 1 and in the temperature range of about -15 ° C to about 80 ° C. Copolymerize. As such a copolymer, for example,
Manufactured by Ausimont, USA: CM-X.

The above-mentioned thermoplastic polyimide resin and 3,3,3-trifluoro-2-trifluoromethylpropene and 1,1-
When compounding a copolymer of difluoroethylene,
This copolymer is blended in an amount of 10 to 90 parts by weight based on 100 parts by weight of the thermoplastic polyimide resin. This is because if the amount is less than 10 parts by weight, excellent non-adhesiveness and sliding properties cannot be obtained, and if the amount is more than 90 parts by weight, high-temperature rigidity and mechanical strength are extremely low.

In the resin composition of the present invention, a general-purpose filler that can be mixed with a general synthetic resin can be appropriately mixed in an amount that does not impair the object of the present invention. Specific examples of such a filler include heat-resistant polymer materials such as silicone resin, polyether sulfone resin, aromatic polyester resin, and polyimide resin, and heat-resistant fiber reinforcing materials (for example, glass fiber, carbon fiber, graphite, and the like). Fibers, potassium titanate whiskers, wollastonite, ceramic fibers, magnesium whiskers, aluminum borate whiskers, steel wires, copper wires, stainless copper wires, silicon carbide fibers and other heat-resistant organic fibers such as inorganic fibers or aromatic amides Fiber), thermal conductivity improver (graphite,
Metals such as zinc and aluminum or magnesium oxide,
Powders of inorganic compounds such as zinc oxide), heat-insulating agents (glass beads, silica balloon, diatomaceous earth, magnesium carbonate powder, asbestos, etc.), lubricating agents (molybdenum disulfide, graphite, carbon, mica, talc, etc.) Lubricants) and coloring materials (iron oxide, cadmium sulfide, cadmium selenide and other inorganic pigments, carbon black, etc.).

Various operations such as blending, heating and mixing of the above-mentioned various raw materials in the present invention are not particularly limited. For example, after dry-mixing with a mixer such as a Henschel mixer or a tumbler mixer, an injection molding machine or the like is directly used. It may be supplied to a melt extruder and molded, or may be melt-mixed with a hot roll, kneader, melt extruder or the like. The melting temperature at this time is 380 to 450 ° C, preferably 390 to 420 ° C. In molding the composition of the present invention, the method is not particularly limited, and compression molding,
Extrusion molding, injection molding and the like are possible. Further, the resin composition of the present invention is melt-mixed, then pulverized by a jet mill, a freeze pulverizer, or the like, and powdered as it is or classified according to a desired particle size. Electric powder coating and the like can be performed.

By subjecting the obtained molded article to a predetermined heat treatment, it is possible to modify the molded article into a molded article having higher rigidity at high temperature and excellent dimensional stability. In particular, it withstands high-temperature use of 240 ° C or higher, and has severe sliding conditions, specifically, the product of surface pressure (kg / cm ² ) and speed (m / min) is 600 (kg / cm ² · m / mi).
For use under conditions exceeding n), those subjected to a predetermined heat treatment are effective. This heat treatment is 250
C. to 320.degree. C., preferably in the range of 270 to 310.degree. This is because if the temperature exceeds 320 ° C., the fluororesin melts, which is not preferable, and if the temperature is lower than 250 ° C., no improvement in heat deformation resistance can be obtained. The time required for the heat treatment may be from 2 minutes to several weeks depending on the heating temperature. As a guide, the density of the thermoplastic polyimide component in the molding material is at least 1.5% or more. The time may be the heat treatment time. Furthermore, if this is specifically shown, it is 12 hours or more under heating at 270 ° C., 1 hour or more under heating at 280 ° C., and 300 ° C. under heating.
10 minutes or more.

Such a heat treatment is performed by placing the molded article in a heating device at a predetermined temperature, and the heating device is conveniently of an electric heating type, and the atmosphere in the device is, for example, a hot air circulation type or the like. A hot air circulation type or the like may be used.

[Action]

The thermoplastic polyimide-based resin composition according to the present invention has, on the surface layer of a molded article molded by injection molding or other methods, 3,3,3-trifluoro-2-trifluoromethylpropene and 1,1-difluoroethylene. The fluororesin, which is a copolymer of, becomes densely distributed, exhibits non-adhesiveness and excellent lubricity and abrasion resistance, and the strength and rigidity of the fluororesin makes the whole molded article excellent in strength. And high-temperature stiffness.

〔Example〕

Raw materials used in Examples and Comparative Examples are collectively shown as follows. In addition, abbreviations are entered in [] and all the mixing ratios are parts by weight.

Thermoplastic polyimide resin (Mitsui Toatsu Chemical: NEW T
PI) [TPI] Copolymer of 3,3,3-trifluoro-2-trifluoromethylpropene and 1,1-difluoroethylene (manufactured by Ausimont, USA: CM-X) [CM-X] polytetrafluoroethylene (Mitsui Dupont Fluorochemicals: Teflon 7J) [PTFE] Polytetrafluoroethylene-hexafluoropropylene copolymer (Mitsui Dupont Fluorochemicals: FER
100) [FEP] Polytetrafluoroethylene-perfluoropropylene copolymer (manufactured by DuPont-Mitsui Fluorochemicals: PFA-
340J) [PFA] Graphite (ACP) [GRP] Examples 1 to 5: Compounded at the compounding ratios shown in Table 1 and supplied to a well-mixed raw material to a twin-screw extruder (PCM-30, manufactured by Ikegai Iron Works Co., Ltd.)
The mixture was melt-mixed under the conditions of a cylinder temperature of 400 ° C. and a screw rotation speed of 80 rpm, and was extruded and granulated. The obtained pellets were injection molded under the conditions of a cylinder temperature of 410 ° C., an injection pressure of 1100 kg / cm ² and a mold temperature of 180 ° C. At that time, Examples 1 to
4 as it is, and Example 5 at 280 ° C.
After heat treatment for hours, friction and wear test pieces (inner diameter 17mm, outer diameter 21m
m, length 10mm), bending test piece (according to ASTM-D790), tensile modulus test piece (width 4mm, length 25mm, thickness 1m)
m) and a contact angle test piece (diameter 10 mm, thickness 3 mm). Each test method for the obtained test piece is as follows.

1) Friction and wear test Using a thrust-type friction and wear tester, the mating material is
J2), the friction coefficient and the wear coefficient (cm ³ kg · m) were determined under the conditions of a sliding speed of 32 m / min and a load of 6.25 kg / cm ² .

2) Bending strength test A method based on ASTM-D790 was used.

3) Tensile modulus test (elastic modulus retention) Tensile stress was applied at a frequency of 10 Hz using a dynamic viscoelasticity measuring device manufactured by Toyo Seiki Seisaku-sho, and changes in tensile modulus with temperature were measured at 25 ° C and 200 ° C. I asked.

4) Non-adhesiveness (contact angle to water) test The contact angle to water was determined using a goniometer type contact angle measuring device GI manufactured by Elma Optical Co., Ltd.

Comparative Examples 1 to 5: Except that the raw materials were mixed at the mixing ratios shown in Table 1, a test piece was prepared by performing exactly the same operation as in Example 1, and the above-described tests were performed. Also shown in Table 1.

From this table, Examples 1 to 5 are excellent in bending strength and tensile modulus, extremely excellent in non-adhesiveness, and very excellent in slidability and wear resistance. In contrast, CM
Comparative Example 1, in which -X was not added, was inferior in non-adhesiveness, slidability (coefficient of friction), and abrasion resistance. Comparative Examples 2 to 4 in which the added fluororesins are PTFE, FEP, and PFA, respectively, have low flexural strength and high temperature rigidity (200
Tensile elasticity at ℃) and poor lubricity and wear resistance. Further, Comparative Example 5 in which a fluororesin (CM-X) was used but the amount of addition was excessive (100 parts by weight)
The bending strength and the high-temperature rigidity were inferior, and the wear resistance was not so good.

〔effect〕

The thermoplastic polyimide resin composition of the present invention has excellent non-adhesiveness without impairing the excellent mechanical, thermal and electrical properties inherent to the polyimide resin, and exhibits extremely favorable sliding characteristics, so that it can be used at high temperatures. Optimum as a sliding member used in Therefore, taking advantage of its excellent non-stickiness, applications requiring lubrication and non-stickiness, such as bearings in copiers that come into contact with strongly adherent toner,
It is a suitable material such as a claw member for peeling copy paper from a rotating body such as a heat roller or a photoconductor, and the significance of the present invention can be said to be extremely large.

Claims (1)

(57) [Claims] (1) Formula (I) With respect to 100 parts by weight of a thermoplastic polyimide resin consisting of a repeating unit represented by 3,10,90 parts by weight of a copolymer of 3,3,3-trifluoro-2-trifluoromethylpropene and 1,1-difluoroethylene. A thermoplastic polyimide-based resin composition characterized by adding a part thereof.