JPS59197455A - Lubricating resin composition - Google Patents

Abstract

PURPOSE:To provide a resin compsn. having self-lubricating properties and wear resistance and suitable for use as a sliding material, by using a specified polyester resin as a base and incorporating a fluororesin and an arom. polyamide resin therein. CONSTITUTION:The titled compsn. is obtd. by incorporating 3-60pts.wt. fluororesin (A) and 3-60pts.wt. arom. amide fiber (B) in 100pts.wt. arom. polyester resin (C) which is composed of a structural unit of formula I (wherein carbonyl groups are bonded to the benzene ring at the meta- or para-position against each other), a structural unit of formula II (wherein O is bonded to the benzene ring at the meta- or para-position against SO2) and a structural unit of formula III (wherein X is a 1-10C bivalent hydrocarbon group, O, SO2, etc.; a is 0, 1 R1-R4 are each H, a 1-8C hydrocarbon group, halogen; when X is SO2, at least one of R1-R4is a group other than H) in a ratio of the unit of formula I to the unit of formula II of 1:0.36-1.06, the unit of formula I to the unit of formula III of 1:0.04-0.66 and the unit of formula I to (the unit of formula II+ the unit of formula III) of 1:0.90-1.10 and in which polymer has a logarithmic viscosity number of 0.2-2.0. By blending the resin A and the fiber B with the resin C, sliding characteristics such as self-lubricating properties, wear resistance, etc. can be remarkably improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin composition suitable for sliding members having excellent self-lubricating properties and wear resistance, which utilizes an aromatic polyester resin having excellent heat resistance and moldability.

Terephthalic acid and isophthalic acid or derivatives thereof;
Aromatic polyesters produced from 2,2-bis(ehydroxyphenyl)propane or its derivatives have mechanical properties such as tensile strength and bending strength, thermal properties such as heat distortion temperature and pyrolysis temperature, and other electrical properties. It is known to be a resin with excellent performance in terms of physical properties, etc. However, although the thermal properties have been improved compared to aromatic aliphatic polyesters such as polyethylene terephthalate, in recent years, considering the heat resistance required for high-performance resins, the aromatic polyesters described in 2. Thermal properties are not always satisfactory.

In particular, these high-performance resins are often used in the electrical and electronic fields, and are now required to have heat resistance in solder baths1. In order to satisfy this requirement, the conventionally known aromatic polyesters mentioned above are clearly insufficient in terms of performance, and it is necessary to further improve the usable temperature range of the resin.

Fully aromatic polyesters, especially terephthalic acid and isophthalic acid or their derivatives, and 2,2-bi,X (4'-
Polyesters such as (hydroxyphenyl)propane have already been investigated in detail (e.g., W. M. Eareckson, J., Pol-y
mer sci, ugliness, 399-406 (1959)
). As mentioned above, this type of polyester is melt processable, the molded product is transparent, and has excellent mechanical properties. However, the glass transition temperature or softening temperature of the polymer is 200°C or less, and the heat distortion temperature of the molded product is 170°C or less, so extremely high heat resistance is required, and dimensional stability at high temperatures is required. It is difficult to use it in fields where

On the other hand, the glass transition temperature of aromatic polyester using bis(hydroxyphenyl) sulfone as the bisphenol component in place of 2.2-bis(4'-hydroxyphenyl)propane reaches around 265°C, which is significantly superior. It has good heat resistance. However, this type of aromatic polyester is difficult to mold, the molded product becomes opaque or cloudy, and even when molded under optimal conditions, it is extremely brittle.
Cracks are likely to occur.

The present inventors previously proposed aromatic polyesters of structural formulas A, B, and An aromatic polyester represented by C was discovered. This aromatic polyester resin has mechanical properties such as tensile strength and bending strength, thermal properties such as heat distortion temperature and thermal decomposition temperature, and electrical properties such as specific resistance, dielectric breakdown, arc suppression, dielectric constant, and dielectric loss. It has excellent performance in terms of physical properties.9 Therefore, it can be used as molded products by extrusion molding, injection molding, compression molding, rotary molding, etc. in the fields of mechanical parts, aerospace parts, electric/electronic parts, etc. It is expected that it will be widely applied.

Various sliding member systems are being considered for the use of the above-mentioned aromatic polyester resin, taking advantage of its heat resistance. However, the aromatic polyester alone is insufficient for use in sliding parts in terms of self-lubricating properties and wear resistance.

In general, as a measure to improve the self-lubricating properties, wear resistance, and sliding properties of resins for sliding members, solid lubricants such as graphite and molybdenum disulfide are added (e.g., Japanese Unexamined Patent Publication No. 56-6-458), Blends of resins having a low coefficient of friction such as fluorinated ethylene resins (e.g., Japanese Patent Publication No. 155163/1983, Japanese Patent Application Laid-open No. 135163/1983), blends of lubricants such as mineral oil, wax, and metal soap (e.g. Although methods such as Japanese Patent Publication No. 46-5321 and Japanese Patent Publication No. 47-42615 are known, it cannot be said that any of these methods sufficiently improves the sliding characteristics.

Products containing the above-mentioned solid lubricants improve load capacity, but hardly any improvement in self-lubricating properties.

In addition, products containing resins with low coefficients of friction such as tetrafluoroethylene have a considerable effect on improving self-lubricity, but they do not have sufficient wear resistance, and the mechanical strength and load capacity of molded products A decline in sexuality is inevitable. Furthermore, when a material containing a lubricant or the like dispersed therein is used by adhering or adhering to another object, it is inconvenient that it is oil-impregnated.

As a result of intensive studies on improving the sliding properties of aromatic polyester, the present inventors found that by blending fluororesin and aromatic polyamide fiber with aromatic polyester, sliding properties such as self-lubricity and abrasion resistance were improved. The present invention was completed based on the discovery that significant improvements could be made.

That is, the present invention provides a) a structure consisting of structural units represented by the following formulas A, B and C, in which the ratio of the number of structural units A to the number of structural units B is 1:o, a6 to 1.06; The ratio of the number of units A to the number of structural units C is 1: 0.04 to 0
66, the ratio of the number of structural units A to the sum of structural units B plus C is 1:0.90 to 1.10, and the logarithmic viscosity of the baked polymer is 02 to 20. [However, in the above formula, in formula A, the carbonyl groups are in the meta or para position to each other, and in the second B, the oxygen atom is SO
In formula C, the oxygen atom is in meta or para position to X. X in formula C is a divalent hydrocarbon group having 1 to 10 carbon atoms, 0, c
o, s, so or S02, a is 0 or 1
It is. R to R4 each represent hydrogen, a hydrocarbon group having 1 to 8 carbon atoms, or a halogen atom, and may be the same or different, but when X is co2, all of R to R4 are not hydrogen at the same time. ] Based on 100 parts by weight, 6 to 60 parts by weight of fluororesin and 3 to 3 parts by weight of aromatic polyamide fiber.
The present invention provides a lubricating resin composition characterized by containing a 60M broken part.

Examples of the dicarboxylic acid component corresponding to the structural unit of formula A used in the aromatic polyester of the present invention include isophthalic acid and terephthalic acid, as well as derivatives thereof. These may be used alone or as a mixture of two or more.

When the isophthalic acid component and the terephthalic acid component are used in combination, the molar ratio of the former to the latter is in the range of 5:95 to 95=5, preferably in the range of 30 nia 0 to 70:30.

Examples of the dicarboxylic acid derivatives include dichloride and diester. When using a diester, raw materials constituting the ester include lower aliphatic alcohols with a carbon number of ~10, phenols with a carbon number of 6 to 18, etc.
be caught.

As a hisphenol component corresponding to the structural unit B of the present invention, bis(hydroxyphenyl)sulfones are used. Bis(4-hydroxyphenyl)sulfontheal is preferred for bamboo.

The above-mentioned bis(hydroxyphenyl)sulfones, while still having hydroxyl groups, are subjected to reactions as various derivatives such as salts with alkali metals or alkaline earth metals, or esters with aliphatic or aromatic carboxylic acids. In some cases. Moreover, the most suitable one is selected depending on the method, form, etc. of the polymerization reaction.

In the present invention, the bisphenol component corresponding to the structural unit of formula C is represented by the following general formula (i) (wherein, X, a, R,
Bisphenols represented by R2, R3, and R4 are as described above) are used.

Specific examples of bisphenols represented by formula I include preferably 2,2-bis(4'-hydroxyphenyl)propane, bis(4-hydroxyphenyl)methane,
2,2-bis(<7methyl4'-hydroquinphenyl)propane, bis(4-hydroxyphenyl)ether, bis(\4-hydroxyphenyl)sulfide, bis(3,5-dimethyl4-hydroxyphenyl) Sulfone, 4,4'-dihydroxybiphenyl, 3.3C5,
Examples include 5'-tetramethyl 4,4'-dihydroxybiphenyl and bis(4-hydroxyphenyl)ketone.

To prepare the polymers of the present invention, bis(hydroxyphenyl)sulfones and bisphenols of formula I as described above are used, but the amount of bis(hydroxyphenyl)sulfones used relative to the dicarboxylic acid component is It is in the range of 036 to 106 moles per mole.

Further, the amount of bisphenols of formula I to be used with respect to the dicarboxylic acid component is from 0.04 to 1 mole of dicarboxylic acid.
The range is 0.66 mol. Furthermore, the total amount of bis(hydroxyphenyl)sulfones and bisphenols of formula I is between 0.90 and 11% per mole of dicarboxylic acid component.
It is in the range of 0 mol.

The polyester of the present invention has a root viscosity ηLnJ of 02 to 2o, preferably 06 to 08, determined by the measuring method described below.
within the range of

The fluororesin used in the present invention is a synthetic polymer containing a fluorine atom (F) in its molecule, and generally has better heat resistance, no toxic chemicals, and electrical properties, especially high frequency characteristics, than other synthetic resins. It has excellent properties and unique low friction and non-stick properties. For example, typical examples include those having the following structural formulas, and at least one kind or a mixture of two or more of these can be used.

(1) -[, CF20F2→0: Polytetrafluoroethylene (PTFE) (2) MoCF20F20F (CF3) CF2-Fn: Tetrafluoroethylene-hexafluoropropylene: Copolymer resin (FE
P) (3) (-(C!F2CF2 +=+ CFC
OR) CF2) -1,: Tetrafluoroethylene par 7
0roalkyl vinyl ether copolymer resin (PFA) (4)+CF20F2-CF(CF3)CF2-CF(
OR) CF2-)n ditetrafluoroethylene-hexafluoroglopyrene-perfluoroalkyl vinyl ether co-M polymer (gpg) (where R is a fluorinated alkyl group, Cn
Indicates Fz mouth +□. ) (5) moCH2CH2CF2CF2-). : 47-ethylene ethylene copolymer resin (ETFE) (6) -E-cH,, CH2cFctcF2-)n
: Trifluorochloroethylene resin (ECTFE) (7) 1,000CF2CH2-3-n: Vinylidene fluoride resin (PVDF) (8) MoCFctcF, -)n: Polychlorotrifluoroethylene (PCTFE) (9) MoCH2CHF →0: Polyvinyl fluoride (
(PVF) Among the above-mentioned fluororesins, completely fluorinated tetrafluoroethylene resin (PTFE) has excellent properties and is most preferably used in the present invention. The amount of these fluororesins added in the present invention is in the range of 3 to 60 parts by weight, preferably 10 to 50 parts by weight, based on the weight of the aromatic ester. If the amount of the fluororesin added is less than part by weight, the effect of improving the self-wetting properties of the resulting resin composition will be undesirable. Furthermore, if the amount of fluorine 1 soybean fat added is more than 60 parts by weight, the resulting resin composition will have poor mechanical properties and moldability, which is not preferred.

Furthermore, the aromatic polyamide fiber used in combination in the present invention is a relatively newly developed heat-resistant organic fiber, and is expected to be used in various fields by taking advantage of its many unique properties. For example, a structure with the following structural formula is i
At least one kind or a mixture of two or more of these can be used.

xevlarJ In addition, it is possible to use aromatic polyamide fibers with various skeletons by creating appropriate isomeric structures such as ortho, meta, and para, but among them, the one with para-para bond (1) has a high softening point and melting point. Therefore, it is most preferably used in the present invention as a heat-resistant organic fiber. The amount of aromatic polyamide fiber added in the present invention is 5 to 60 parts by weight, preferably 10 to 5 parts by weight, per 100 parts by weight of the above-mentioned aromatic polyester.
It is within the range of 0 heavy weights. If the amount of aromatic polyamide fiber added is less than 6 parts, the effect of improving the abrasion resistance of the resulting resin composition is undesirable. Furthermore, if the amount of aromatic polyamide fiber added is more than 60 parts by weight, the mechanical properties and moldability of the resulting resin composition will deteriorate, which is not preferable.

In addition, from the viewpoint of mechanical properties and molding processability of the resulting resin composition, the total amount of fluororesin and aromatic polyamide fiber added should be i to 100 parts by weight of aromatic polyester.
It is more preferable that the amount is oo parts by weight or less.

The resin composition of the present invention further includes fibrous reinforcing materials such as carbon fibers and glass fibers, granular reinforcing materials such as calcium carbonate, talc, and silica, antioxidants and Usual additives such as a stabilizer such as a funonoshi type antioxidant and a phenol phosphite type antioxidant, a lubricant and a mold release agent such as stearic acid and its metal salts, and a pigment can be added.

There is no particular restriction on the method of adding the fluororesin and aromatic polyamide fiber to the aromatic polyester of the present invention, and various means can be adopted. After that, it is generally supplied to an extruder, melted and kneaded, and extruded into pellets. The lubricating resin composition of the present invention thus obtained can be molded into any molded product by a molding method such as injection molding, extrusion molding, or compression molding, and the molded product has excellent sliding properties. Taking advantage of its dynamic properties, it is used in various sliding parts, such as various bearings, piston rings, gears, cams, and various valve parts.

The present invention will be explained in more detail below with reference to Examples. Note that the logarithmic viscosity ηLy+/L in the following examples is determined by the following formula using an o, 5 r /di solution using a mixed solvent of phenol/tetrachloroethane (weight ratio 6/4).

t2 (In the above formula, t□ is the flow time of the polymer solution, t2 is the flow time of only the solvent, and C is the polymer solution concentration (P/
dt). ) Examples 1 to 9 and Comparative Examples 1 to 4 Bis(4-hydroxyphenyl)sulfone 35Kg (1
4 mol), 2,2-bis(4'-hydroxyphenyl)
167 kg (6 moles) of propane and 238 g (14 moles) of O-phenylphenol.
% sodium hydroxide aqueous solution was added and dissolved, and the mixture was cooled to 10°C i/). A stream of N2 was introduced into this solution for 3
0 minutes, cetyltrimethylammonium bromide 1
07 was added.

A solution of 420 mol of a mixture of inophthaloyl chloride and terephthaloyl chloride (1:1) (207 mol) dissolved in 60 A of dichloromethane was added once to the solution in the above-mentioned reactor kept at 10°C and stirred. in addition to 10℃
Stirring was continued for 1 hour while maintaining the temperature.

As a result of sampling the reaction solution and analyzing it by low molecular weight gel chromatography, no unreacted monomer was found. Then, after adding 1N hydrochloric acid aqueous solution st,
Add 0 t of water, stir and let stand to separate the lower layer.
It was further washed twice with sOt water. The washed /chloromethane layer was added to 120 t of methanol which was stirred at high speed with a homomixer to precipitate a polymer. The precipitated colorless polymer was separated by P, further washed with methanol and dried to obtain a polymer powder of 7.43 mm.

The logarithmic viscosity of the obtained polymer was 054, and Nhl
From the IR spectrum, the abundance ratio of bis(4-hydroxyphenyl)sulfone residues and 2,2-bis(4'-hydroquinophenyl)furon residues in the polymer was approximately 7=6.

The thus obtained aromatic polyester, fluororesin powder (tetrafluoroethylene resin manufactured by Mitsui Fluorochemical Co., Ltd., trade name Teflon PT, P-10) and aromatic polyamide fiber (manufactured by DLI Pant Co., Ltd., trade name Kev)
lar) in the amounts listed in Table 1, and then
It was extruded into pellets using a single-screw extruder (i) at a cylinder temperature of 340°C. Further, this pellet was molded into a test piece using an injection molding machine at a cylinder temperature of 350-380°C and a mold temperature of 150°C, and the sliding properties were measured.
However, the results shown in Table 1 were obtained.

The coefficient of friction is based on a stainless steel mating material and a surface pressure of 10 kg A4. It was measured at room temperature using a Matsubara friction tester at a speed of 10 Cm/SeC. Also, the wear coefficient is surface pressure 5Kf/cnf, speed IDOm/m
Measurement was carried out at room temperature using a cylindrical abrasion tester under in conditions.

Table-1

Claims (1)

[Scope of Claims] A) Structural units represented by the following formulas A, B, and C, where the ratio of the number of structural units A to the number of structural units B is 1=0.
36 to 106, the ratio of the number of structural units A to the number of structural units C is 1:0.04 to 066, and the ratio of the number of structural units A to the sum of structural units B plus C is 1:0. .9
Aromatic polyester resin having a polyamide viscosity of 0 to 110 and a polymer logarithmic viscosity of 02 to 20 [However, in the above formula, in formula A, the carbonyl groups are in meta or para positions with respect to each other, and in 2B, the oxygen atom is In formula C, the oxygen atom is in the meta or para position to the SO2 group. X in formula C is a divalent hydrocarbon group having 1 to 1 carbon atoms, 0, co, sX so or SO
2, and a is o- or 1. R~R4 each represent hydrogen, a hydrocarbon group having 1 to 8 carbon atoms, or a halogen atom, and may be the same or different, but when X is SO2, all of R~R4 are not hydrogen at the same time. ]100
6 to 60 tonne parts of fluororesin and no →
A lubricating resin composition comprising 3 to 60 parts by weight of aromatic polyamide fiber.