JPS59170138A - Polyester resin composition - Google Patents

Abstract

PURPOSE:To obtain titled composition capable of manufacturing at low cost and in a simple way formed products of excellent physical properties such as sliding and tensile characteristics, by incorporating a thermoplastic polyester resin with such ingredients as polyoxyalkylene compound, solid lubricant, lubricating oil, etc. CONSTITUTION:The objective composition can be obtained by incorporating (A) 70-99.6pts.wt. of a thermoplastic polyester resin preferably containing >=80mol% of ethylene terephthalate recurring unit with (B) 0.1-10pts.wt. of a solide lubricant consisting pref. of molybdenum disulfide with a particle size 1-10mu, (C) 0.1-10pts.wt. of a lubricating oil consisting pref. of silicone oil with a dynamic viscosity 10-200cst, and (D) 0.2-10pts.wt. of a polyoxyalkylene compound (pref. a polyalkylene glycol glycidyl ether, and further, pref. (E) both fibrous and powderlike fillers.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polyester resin composition,
More specifically, the present invention relates to a polyester composition with improved sliding properties.

Thermoplastic polyesters such as polyethylene terephthalate have excellent heat resistance, chemical resistance, mechanical properties, etc.5
It is widely used in various applications such as fibers, films, injection molded products, etc. However, since injection molded products have poor sliding properties, they are not suitable for molded products that are subjected to friction such as rotary shaft bearings, slide parts, etc., and polyoxymethylene resin is generally used.

Conventionally, in order to improve the sliding properties of thermoplastic polyester resin, lubricating oil was absorbed into polyethylene, and this was blended with polyester together with a surface improver such as molybdenum disulfide. Japanese Patent Application Publication No. 5
This has already been disclosed in Japanese Patent No. 0-1'57443.

However, it has drawbacks such as the fact that the heat deformation temperature tends to decrease due to the blending of polyethylene with a low melting point, and the polyethylene itself tends to peel off in layers due to its lack of compatibility with polyester. Furthermore, the addition of a large amount of a surface improver such as molybdenum disulfide is disadvantageous in terms of cost and has the disadvantage that the advantages of 2-plastic are lost or halved.

In addition, silicone oil, low molecular weight polyolefin, etc. have the disadvantage of not only having poor injection properties into the screw during injection molding, but also reducing the weld strength of the molded product, and there is a limit to the amount they can be blended, making it difficult to achieve advanced sliding properties. It is impossible to grant. I cut it. In particular, graphite has a small effect and requires a large amount of compounding to impart sliding properties, and the resulting molded products have problems such as low strength and elongation, making them impractical. The inventors have developed a composition that has excellent sliding properties and provides molded products with excellent strength, elongation, and other physical properties at a low cost.
As a result of extensive research, we have arrived at the present invention in order to easily manufacture the 7. That is, 2. the present invention comprises 70 to 99.6 parts by weight of a thermoplastic polyester resin, 0.1 to 10 parts by weight of a solid lubricant, 0.1 to 10 parts by weight of a lubricating oil agent, and 0.2 to 10 parts by weight of a polyoxyalkylene compound. The composition according to the present invention is characterized by the fact that by blending specific compounding agents in a specific proportion, the composition itself can be manufactured easily, and the composition itself can be easily manufactured by blending the polyoxyalkylene compound. The dispersibility distribution of the lubricant is the most effective state for improving sliding properties, and the coefficient of friction is lowered by exhibiting a synergistic effect with the polyoxyalkylene compound. It can provide excellent sliding properties, and also has the characteristics of showing no or almost no deterioration in thermal properties such as 2 strength elongation, and even improving the hardness in low-temperature mold forming. are doing.

Examples of the thermoplastic polyester resin used in the present invention include polymers or copolymers obtained by a polycondensation reaction using a monoaromatic dicarboxylic acid or an ester-forming derivative thereof and a glycol or an ester-forming derivative thereof as the product components. It will be done.

Examples of aromatic dicarboxylic acids include terephthalic acid, 1.4-
Or 2,6-naphthalene dicarboxylic acid, 4,4'-diphenylmethane dicarboxylic acid! , 4,4'-diphenyl ether dicarboxylic acid and the like. Examples of glycols include ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 21,6-hexanediol, and cyclohexane dimetatool. Aliphatic diols having 2 to 10 carbon atoms or long chain glycols having a molecular weight of 400 to 6000, such as polytetramethylene glycol, polypropylene glycol, polylactone glycol, 2.2-bis(4-
Examples include hydroxyphenyl)propane.

In addition to the above ingredients, there is also an acid component (and adipic acid).

Aliphatic dicarboxylic acids such as sebacic acid, azelaic acid and dimer acid, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, aromatic dicarboxylic acids such as inphthalic acid and 5-sodium sulfoiphthalic acid, glycol components As copolymerization components, diethylene glycol, diglopylene glycol, polyhydric alcohol-alkylene oxide adduct-oxyacid, oxybenzoic acid, oxyethoxybenzoic acid, etc. can be used. Further, all trifunctional or higher functional ester-forming components may be used within a range that does not impair moldability.Specific thermoplastic polyester resins include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, Examples include polycyclohexane dimethylene terephthalate.

The intrinsic viscosity of the polyester resin measured in a mixed medium of haphenol/tetrachloroethane (6/4 weight ratio) at 30°C [7] is usually 0.4 or more, preferably 0.5 or more. The polyester resin may be a blend of two or more types, but is particularly preferably polyethylene terephthalate, polybutylene terephthalate, or a polyester resin containing at least 80 moles of 7 units, Among these, polyester resins containing at least 80 moles of ethylene terephthalate repeating units are particularly preferred.

Furthermore, as the solid lubricant used in the present invention, m
Examples include inorganic solid lubricants such as molybdenum sulfide, binary tungsten-graphite, carbon black, and graphite fluoride, and organic solid lubricants such as tetrafluoroethylene resin, which may be used alone or in combination. A particularly preferred solid lubricant is molybdenum disulfide. In addition, the particle size of the solid lubricant is usually 100μ or less, and the diameter of the solid lubricant is usually 10μ or less.
It is as follows. In particular, divalent f-hymolybdenum is reduced to 0.1/30
μ, particularly preferably 1 to 10 μ. If it exceeds iooμ, the sliding properties will be insufficient.

Examples of lubricating oil agents used in the present invention include charcoal and arsenic oil that is liquid at room temperature or becomes liquid when heated, higher fatty acid esters, higher fatty acid metal salts, silicone oil, perfluoroalkyl carboxylic acid metal salts, Perfluoroalcohols and the like are difficult to use, and usually have a kinematic viscosity of 1 to 1 at 25° C. When melted and mixed with polyester, a slip phenomenon occurs and stable production cannot be obtained. On the other hand, if the viscosity is too high, the compatibility with polyester is poor, resulting in poor dispersion of the silicone oil, resulting in a reduction in strength and elongation of the molded product.

Further, the polyoxyalkylene compound used in the present invention is not particularly limited, and includes polyethylene glycol, polypropylene glycol, and polytetramethylene glycol.

Polyether glycols with polyoxyalkylene chains such as ethylene oxide Φ propylene oxide random or block copolymers, alkylene oxide adducts of polyhydric alcohols, alkylene oxide adducts of polyhydric carboxylic acids, or their mono, diether, mono,
Diesters.

Phthalic acid ester of polyether glycol, diglycolic acid ester-polyoxyalkylene phenyl ether sulfonic acid, etc., which have all anionic groups introduced at the end of the polyoxyalkylene chain, and metal salts thereof, anions of the compounds. 2. Unsaturated alcohol ethers of polyether glycol, polyether compounds with unsaturated groups such as unsaturated acid esters, parts of carboxylic acid group-containing polymers. Polyalkylene glycol esters, epoxy compounds having a polyoxyalkylene chain, etc. are exemplified, and these compounds may be used alone or in combination of two or more, and are particularly preferred. It is a metal product, especially in the general formula, A: C, -5 aliphatic carbon hydrogen group, hydrogen or glycidyl group, general: 02-5 aliphatic carbon f arsenic group n: an integer of 2 or more. Polyalkylene glycol glycidyl ether is preferred. Specific examples of the compound include mono- or diglycidyl ether of polyethylene glycol;
Examples include polyalkylene glycol mono- or diglycidyl ether, polytetramethylene glycol mono- or diglycidyl ether, and lycidyl ether. The molecular weight of the polyoxyalkylene compound is usually about 20,000 Jl or less, but if it is over 5,000 Jl, it can also provide an antistatic effect, while if it is less than 5,000 Jl, it can also have a crystallization promoting effect (7. In particular, when it is less than 5000, the surface smoothness of the molded product is improved by promoting crystallization in addition to the dispersibility of the lubricant, and the sliding effect can be further improved.

Especially 200-3000. Among these, a molecular weight of about 800 to 1,500 is more preferable. A combination of high molecular weight and low molecular weight may be used. Further, a polyoxyalkylene compound having a group reactive with the epoxy compound can also exhibit excellent effects when both are used in combination.

In the present invention, thermoplastic polyester resin 70 to 9
9.6 parts by weight, 0.1 to 10 parts by weight of the solid lubricant, 0.1 to 10 parts by weight of the lubricating oil, and 0.2 to 103 parts by weight of the polyoxyalkylene compound.

If the amount of the solid lubricant is less than 0.1 parts by weight, the effect of imparting sliding properties will be small, while if it exceeds 10 parts by weight, the impact strength will be reduced. Furthermore, if the lubricant is less than 0 or i parts by weight, the effect of imparting sliding properties will be small, while if it exceeds 10 parts by weight, it will not form into a strand state during bath melt mixing with polyester resin, making stable 11kl production difficult. Furthermore, if the polyoxyalkylene compound is less than 0.2 parts by weight, the sliding properties, formability, and strength and elongation are insufficient, while if it exceeds io parts by weight, water absorption increases and the compound is Depending on the type of material, gelation may occur during kneading or molding, or the physical properties of the molded product may deteriorate.

The compositions of the present invention may optionally further include fibrous and /'-
1. Can be completely blended with bamboo powder reinforcing agent.

Examples of fibrous reinforcing agents include glass fibers, carbon fibers, metal fibers, metal carbide fibers, potassium titanate fibers, whiskers, aromatic polyamide fibers, etc. Glass fibers are particularly preferred, and the diameter is 15 μm or less. Furthermore, it is preferable that the particle size is 10μ or less and has been subjected to surface treatment or sizing agent treatment for plastic reinforcement.Powdered reinforcements include talc, clay, 5-kaolin, mica, wollastonite, asbestos, silicates such as calcium silicate, and oxides. Examples include titanium, silica, calcium sulfate, magnesium carbonate, calcium carbonate, alumina, etc., and talc, mica, wollastonite, etc. are particularly preferred. The particle size of the powdered reinforcing agent is preferably 20μ or less, more preferably 10μ or less, from the viewpoint of the appearance and physical properties of the molded product. The amount of fibrous reinforcing agent is 12% of the total composition.
It is usually less than 50 weight SJM, preferably (7 to 3 to 40 weight). It is 20% by weight.

The composition of the present invention may further include acid famine inhibitors, ultraviolet absorbers, flame retardants, flame retardant aids, mold release agents, plasticizers, colorants, antistatic agents, organic crystals, etc., depending on the purpose and use. Accelerators, crosslinking agents, impact modifiers, etc. can be added as appropriate.

The method for producing the composition is not particularly limited, and any method may be used. A method of adding and kneading all solid lubricants, lubricants, polyoxyalkylene threads, etc. in the latter stage of polycondensation of polyester, pellets or powder polyester resin, solid lubricants, lubricants, polyoxyalkylene-based compounds, etc. Pre-mix hardware, etc.]-
After that, the mixture is melt-kneaded using an extruder, kneader, or the like.

The composition of the present invention does not require any special molding method, and can be molded under normal thermoplastic resin molding conditions.
Provides molded products with excellent sliding properties and mechanical strength. Therefore, it can be widely used as various molded products and sheet-like products such as plates.
Bearing bush, 5 gear wheels, cam, 5 rollers, reel,
It is suitable as a molding material for parts such as IJ retainers of rolling bearings, seals and other low-friction members, and various electrical appliances and electronic devices.

The present invention will be fully explained below with reference to Examples. Note that parts and weights in the examples are based on weight. Further, the characteristics of the test pieces in the examples were evaluated by the following method.

(1) Coefficient of dynamic friction ASTM D-1894-61T (2) Specific wear amount Thrust type friction, abrasion tester Compatible material R4s 4oo” lapping surface pressure 6
．． 25 Fi, 'v/m, 2, speed 50m/5ec (3
) White is test ARTM D-790 (4) Impact test A! '+TM 1. ) -256 Example 1 Polyethylene terephthalate c or less, abbreviated as PET, intrinsic viscosity 0.58. Melting point 2soO) and divalent f-hymolybdenum c
Particle size: 5μ) Silicone oil (Kinematic viscosity at 25℃: 30'cs)
) and polyethylene 17 glycol diglycidyl ether (after premixing), the mixture was poured into the hopper of a 30 IP M30 two-fine extruder (Ikegai Tekko Co., Ltd.) and melted and mixed at a cylinder temperature of 280-280-280'0. R [7, pellets were obtained. After drying the obtained pellets at 120° C. under reduced pressure for 17 hours, the cylinder temperature was 270-275-275'.
Q. Injection molding machine FS-75 with mold temperature adjusted to 9m0K
(8 Seijin Kogyo Co., Ltd.) to mold a test piece. Note that the comparative example was also molded in the same manner.

Table 1 shows the characteristic values of the obtained test piece.

As a result, by using a lubricant and a polyoxyalkylene fb compound in combination, a molded article having excellent sliding properties and physical properties was obtained by low-temperature molding due to the synergistic effect of both ingredients.

Example 2 The same PET as in Example 1, divalent f-hypolybdenum, silicone oil, polypropylene glycol diglycidyl ether, and 3U cut of glass fiber with a diameter of 13μ) total 285°C
The mixture was melted and kneaded to obtain pellets.

A test piece was molded in the same manner as in Example 1 using this pellet.

Table 2 shows the characteristic values of the obtained test piece.

As a result, a molded article with excellent sliding properties and good physical properties was obtained for the first time by using a solid lubricant, a lubricating oil agent, and a poly(oxylalkylene compound) in combination.

Patent applicant: Toyobo Co., Ltd.

Claims (1)

[Claims] ■ 70 to 99.6 parts by weight of thermoplastic polyester resin;
01 to 1 parts by weight of solid lubricant, 0.1 to 10 parts by weight of lubricating oil, and 0.2 to 1 part by weight of polyoxyalkylene compound
A polyester resin composition containing 0 parts by weight. 2. The polyester resin composition according to claim 1, wherein the polyester resin composition contains a fibrous and/or powdered reinforcing agent. 3. The polyester resin composition according to claim 1, wherein the thermoplastic polyester resin is a polyester containing at least 80 moles φ of ethylene terephthalate repeating units.