JPS5834507B2 - Oxybenzoyl Polyester Tonososeibutsu - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composition of a fluororesin and an oxybenzoyl polyester.

Polytetrafluoroethylene is a resin with a small coefficient of friction, but in order to improve its mechanical properties, it has been mixed with glass.

Mixing glass improves the wear characteristics and has been used as a bearing material, but compositions containing glass have disadvantages such as damaging the mating material and being completely unusable with water lubrication.

The fluororesin used in the present invention, which has greatly improved the processability of polytetrafluoroethylene, has both a coefficient of friction and a coefficient of wear that are considerably inferior to polytetrafluoroethylene, and cannot be used alone as a sliding member such as a bearing. cannot be used.

Improving abrasion properties by mixing glass can be easily inferred from polytetrafluoroethylene and is actually an improvement, but as with polytetrafluoroethylene, it may damage the mating material or cannot be used due to water lubrication. The deficiencies could not be improved.

The fact that the defect of damaging the mating material has not been improved is offset by the excellent feature that the fluororesin used in the present invention has greatly improved the processability of polytetrafluoroethylene, such as being versatile in extrusion molding and injection molding. The result was a mess.

This is because conventionally, when glass is added to extrusion moldable or injection moldable resins, the damage to screws, cylinders, and nozzles is large, and this has been avoided despite the possibility of improving mechanical properties.

This is a similar problem for those skilled in the art regarding the fluororesin used in the present invention.

Compositions of polytetrafluoroethylene and oxybenzoyl polyester have already been described in US Pat.
No. 44593.

This patent is characterized by compressing a composition of polytetrafluoroethylene and oxybenzoyl polyester to obtain a composition with excellent sliding properties, but unlike the composition of the present invention, extrusion molding It was unimaginable that the equipment would not be damaged during injection molding. This was the first time I was able to do it.

Surprisingly, bearings made from the composition of the present invention exhibited excellent friction and wear characteristics that were far superior to those of glass-containing fluororesin when lubricated with water.

Oxybenzoyl polyester itself has very good abrasion resistance, high pv value, and also has high resistance to acids, alkalis, and organic and inorganic solvents, and can be used normally at 300℃.
It has heat resistance, excellent electrical properties, and thermal conductivity.

In particular, the pv value itself is 7 times that of polytetrafluoroethylene, and the pv value of polytetrafluoroethylene is 20 times higher than that of polytetrafluoroethylene.
% mixed composition has a larger pv value than porous bronze.

Furthermore, the thermal conductivity is about 3 to 10 times higher than that of thermoplastic resin.

Oxybenzoyl polyesters that can be used in the present invention generally have repeating units of the following formula (I).

One preferred embodiment of the oxybenzoyl polyester is represented by the following formula (II).

In the above formula, R1 is a member selected from the group of benzoyl group, lower alkanoyl group, or hydrogen, R2 is hydrogen, benzyl group, lower alkyl group, or phenyl group, and p is 3 to 600, preferably 30 to 200. is an integer.

The above p values are approximately 1,00 when converted to molecular weight.
0 to 72,000. Preferably 3,500 to 2
Corresponds to a molecular weight of 5.000.

The method for synthesizing these polyesters was published in Japanese Patent Publication No. 46-6796.
No. 45-124422 and Japanese Patent Application No. 1982-124422.

Another preferred embodiment of the oxybenzoyl polyester has the formula (
It is a copolyester having repeating units of I) and the following formulas (IID and (g)).

In the above, X is or -SO2; m is O or 1; n is O or 1; q: r
=10:15 to 15:10; p:q=1:1
oo to 100:1, and p+qr=3 to 600, preferably 30 to 200.

Also, the carbonyl group of the repeating unit of formula (I) or (IID) is bonded to the oxy group of the repeating unit of formula (I) or (IV); I) or to the carbonyl group of the repeating unit of formula (IID).

The synthesis method of these polyesters is described in Japanese Patent Publication No. 47-4787.
It is described in Publication No. 0.

The polyester that can be used in the present invention may further include a monofunctional component such as benzoic acid, or a trifunctional or more polyfunctional component such as trimesic acid or cyanuric chloride introduced into the polyester. can be chemically modified by various methods.

The benzene ring in these polyesters preferably has no substituents, but non-sterically hindered substituents, such as halogens such as chlorine and bromine, lower alkoxy groups such as methoxy groups, and methyl groups, are preferred. It may be substituted with a lower alkyl group such as

Furthermore, a composite material obtained by the manufacturing method specified in Japanese Patent Application No. 48-42397 can also be used.

The fluororesin used in the present invention is an ethylene/tetrafluoroethylene copolymer, an ethylene/chlorotrifluoroethylene copolymer, or a tetrafluoroethylene/fluorovinyl ether copolymer that can be extruded or injection molded.

As a method for mixing the composition of the present invention, the oxybenzoyl polyester powder and the fluororesin can be simply mixed in a Henschel mixer, a roll, or suspended in a liquid, and then pelletized using an extruder.

The mixing ratio is 5 to 80 parts by weight of oxybenzoyl polyester to 95 to 20 parts by weight of fluororesin.

Needless to say, the composition of the present invention sufficiently retains the above-mentioned excellent characteristics of oxybenzoyl polyester, and also has the same properties as the case where glass is used as a filler, such as an increase in heat distortion temperature, an improvement in mechanical strength, and excellent properties. It has sliding properties, chemical resistance, and mold release properties.

The present invention will be explained below with reference to Examples, in which parts are by weight unless otherwise specified.

Furthermore, the Examples are intended to illustrate preferred embodiments of the present invention, and are not intended to limit the scope of the present invention.

Example 1 856 g of phenyl parahydroxybenzoate and 0.
015g of tetra-n-butyl orthotitanate and 1s
A mixture of oo and p with Santotherm 77 (Mitsubishi Monsanto ■ trade name) as a solvent was heated at 170 to 190°C for 4 hours under a nitrogen stream with constant stirring, then for 34 hours.
Heated at 0-360°C for 10 hours.

At the beginning of this heating cycle, the mixture became a homogeneous liquid.

A condensation reaction occurred during the heating cycle, resulting in precipitation of the resulting polyester with distillation of phenol.

The mixture was cooled to room temperature, extracted with acetone to remove the above Santotherm 77 solvent, and the product was purified in vacuo at 60°C.
Dry overnight at °C.

The yield of polyester powder was 377 g, which consisted essentially of paraoxybenzoyl polyester.

30 parts by weight of this paraoxybenzoyl polyester,
The product name manufactured by DuPont in the United States is "Tefzel 20".
The ethylene/tetrafluoroethylene copolymer in Oj (pellet form) was once ground, and 70 parts by weight of the powder was mixed in a Henschel mixer and pelletized at 300°C using an extruder.

Using the pellets, Sumitomo Heavy Industries, Ltd. Neomat ■47/
Using a 28 injection molding machine, the cylinder front part 3500C,
The screw was injection molded using Hastelloy C under conditions of 340°C in the center, 330°C in the rear, and 350°C at the nozzle.

Using the same injection molding machine, a 25% glass fiber-filled ethylene/tetrafluoroethylene copolymer manufactured by DuPont under the trade name "Tefzel 70G-25J" was injection molded.

"I shot pellets of 70 parts by weight of Tefzel 200j/30 parts by weight of paraoxybenzoyl polyester 1500 times and inspected the cylinder and screw, but there were no scratches at all, but after shooting the same number of times with Tefzel 70G-25, the cylinder, I checked the screw, but
The screw was severely damaged and there were many lines in the cylinder.

As a result of measuring the physical properties using an injection molded test piece, the specific gravity was 1.
．． 61, tensile strength 800 kg/d, elongation 25, compressive strength 630 kg/CIt, and heat distortion temperature 221°C.

Example 2 A round bar with a diameter of 15 mm was extruded using the pellets of Example 1,
A bearing with an outer diameter of 12 mm, an inner diameter of 6 mm, and a length of 10 mm was made by cutting it, and the bearing was tested in air at room temperature without lubrication using a small bearing testing machine made by Toyo Seiki, which works very well for testing. Using material 5KH-2 (quenched) for the shaft, the machine was run for 1 hour at a load of 70 kg/cIL and a speed of 3 m/min, and the friction and wear characteristics were measured; the coefficient of friction was 0.38, and the coefficient of wear was 0.38. is 7.0X10 (notification)/(closure)
Met.

A similar test using Tefzel 70G-25 resulted in a friction coefficient of 0.55 and a wear coefficient of 28. lX1O-5(5
)/(i).

When the shaft was viewed under a microscope after the measurement, the composition of the present invention was not damaged, but Tefzel 70G-25 had many thin streaks like a record board.

Example 3 A round bar with a diameter of 30 mm was extruded using the pellets of Example 1, and a test piece was cut into an outer diameter of 25.6 mm, an inner diameter of 20 mm, and a length of 15 mm. Thrust bearing type friction and wear tests made by Toyo Baldwin were performed using test pieces. Machine mating material SUS 304
(outer diameter 25.67 WW, inner diameter 20 mm, length 15 mm) was subjected to a friction and wear test under room temperature water lubrication conditions, and the friction coefficient was 0.21 at a load of 20 kg/d and a speed of Low/min.
, wear coefficient 2. It was 1X1O-5(,,)/(cloudy).

A similar test was conducted using m-door Tefzel 70G-25, and the wear coefficient was 0.31 and the friction coefficient was 230X10-5 (
5)/(thin).

Example 4 Instead of "Tefzel 200" in Example 1, 70 parts by weight of ethylene/chlorotrifluoroethylene copolymer whose trade name is "Halar" manufactured by Allied, Inc. in the United States and 30 parts by weight of paraoxybenzoyl polyester of Example 1 were used. was pelletized using an extruder at 280°C and injection molded.

The injection molded product has a specific gravity of 1.60 and a tensile strength of 590 kg/
The elongation was 1ffl and 22%.

When a friction and wear test was conducted using the wear tester of Example 2 under the same conditions as Example 2, the friction coefficient was 0.35 and the wear coefficient was 10. OX 10-5(1)/(occlusion).

After the measurement, the shaft was examined under a microscope, and the composition was found to be almost undamaged.

Example 5 30 parts by weight of the same roseoxybenzoyl polyester as used in Example 1 and 70 parts by weight of tetrafluoroethylene copolymer whose trade name is Teflon PFA 340JJ (pellet form) manufactured by Mitsui Fluorochemical Co., Ltd. The mixture was mixed using a Henschel mixer, and extruded pellets were obtained by using an extruder and setting the temperature at the center of the cylinder to 370°C.

Using the pellets, Sumitomo Heavy Industries, Ltd. Neomat ■47/
Using a 28 injection molding machine, the rear part of the cylinder was 370°C, the center part was 380°C, and the front part of the cylinder and the nozzle were 380°C.
Injection molding was carried out under the following conditions.

Under exactly the same conditions, 70 parts by weight of Teflon PFA 340J and 30 parts by weight of short glass fibers (REV-8, manufactured by Nippon Glass Fibers Co., Ltd.) having a fiber length of 100 μm to 200 μm were mixed and granulated and then injection molded.

"I shot pellets consisting of 70 parts by weight of Teflon PFA340JJ/30 parts by weight of paraoxybenzoyl polyester 1000 times and examined the cylinder screw, but there was no damage at all.
After performing the same number of shots using pellets consisting of 70 parts by weight of 0Jj/30 parts by weight of glass fiber, the cylinder and screw were examined, and as in Example 1, the screw and cylinder had many linear scratches.

Physical properties were measured using an injection molded test piece, and the results were that the specific gravity was 1.86, the tensile strength was 280 kg/d, and the elongation was 24%.

In addition, using the same method and conditions as in Examples 2 and 3,
We measured the dry sliding characteristics and water lubrication characteristics and
A comparison was made with one consisting of 70 parts by weight of FA340JJ/30 parts by weight of glass fiber.

As shown in Table 1, the friction coefficient and wear coefficient were both lower than that of the glass fiber-filled product, and no damage or wear was observed on the mating material.

Claims (1)

[Claims] 1 20 to 95 parts by weight of extrusion or injection moldable ethylene/tetrafluoroethylene copolymer, ethylene/chlorotrifluoroethylene copolymer or tetrafluoroethylene/fluorovinyl ether copolymer and 80 to 5 parts by weight of oxybenzoyl polyester A resin composition for extrusion molding or injection molding.