JPS61235124A - High-temperature extrusion of extruded form consisting of aromatic polyester series thermoplastic resin powder - Google Patents

Abstract

PURPOSE:To permit the high-temperature extrusion forming of extruded form consisting of heat resistive aromatic polyester series thermoplastic resin powder by a method wherein the powder of macromolecular material is sealed into a metallic case and heated to a predetermined temperature after evacuating the case, thereafter, is formed by extrusion under a predetermined extrusion pressure. CONSTITUTION:The powder 20 of an objective macromolecular material or the powder of aromatic polyester series thermoplastic resin is sealed into the metallic case 21 of copper and the case is evacuated, thereafter, the case is covered with a copper cap 23 having a taper 22 to make a billet 26. The heat- resistive, anti-abrassive and light-weight extruded form, consisting of the aromatic polyester series thermoplastic resin powder may be obtained by the high- temperature extrusion of the billet under the heating temperature of 200-400 deg.C and the extruding pressure of 200MPa or higher. This extruded form is excellent in mechanical property and the use thereof for mechanical structural component, such as bush, bearing and the like, may be expanded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a high-temperature extrusion method for extruded materials made of aromatic polyester thermoplastic resin powder, and is used to extrude extruded materials such as mechanical structural parts such as bushes and bearings, and slide shoes. This invention relates to a method for producing extruded materials that can be used as heat-resistant sliding parts.

(Prior Art) Heat-resistant polymer materials can be used at high temperatures, with a continuous usable temperature of 200° C. or higher, so their properties can be utilized to reduce the weight of mechanical parts.

In order for a polymer material to have excellent heat resistance, it must have a high softening temperature or heat distortion temperature, that is, it must not undergo physical changes even at high temperatures.

In addition, it will not be oxidized or thermally decomposed even at high temperatures.
In other words, it is required that no chemical changes occur even at high temperatures.

The following methods are available to meet such demands.

1) Increasing the rigidity of the main chain of the molecule, that is, introducing a ring structure into the main chain.

2) Making the arrangement of molecules regular.

3) Increasing the molecular cohesive energy, that is, introducing many polar bonds.

4) Cross-linking the molecules with a suitable cross-linking agent to improve their function. 5) Improving heat resistance using fillers.

And so on.

However, since all of these methods try to make the molecules as mobile as possible, molding is extremely difficult.

For example, Publication No. 22 of the Plastic Reader (Plastic Reader Editorial Committee, Plastics Technology Association, Osaka Cultural Industrial Research Institute), revised 8th edition dated May 10, 1971.
As stated on page 1, EKONOL, which was commercialized by CARBORUNDUM Co., is a self-condensed product of P-oxybenzoic acid and has a structure of 40-Q-COO+η. Although it has a clear softening point and thermally decomposes at 500°C, it can be used continuously at 310°C.

However, although they are called thermoplastics, they have poor moldability and vary depending on the type, and many of them are used by compression molding of powder, pressure sintering, or as a blend material for fluororesin, and are used to improve the creep characteristics of the filler (material). This merely makes it possible to improve wear resistance.

(Problems to be Solved by the Invention) If the above-mentioned heat-resistant plastic material, that is, aromatic polyester thermoplastic resin powder, can be solidified and molded, heat-resistant,
Although it has a wide range of uses as a lightweight mechanical component that takes advantage of its wear-resistant properties, its use has been extremely limited due to the difficulty of molding it in the past.

The object of the present invention is to extrude aromatic polyester resin powder, which has conventionally been considered difficult to mold, using a high-temperature extrusion method.

(Means for Solving the Problems) The first feature of the technical means taken by the present invention to achieve the above-mentioned object is that the target polymeric material powder is degassed and sealed in a metal case. After that, heat it at the specified temperature,
Thereafter, the extruded material is extruded at a predetermined extrusion pressure, and the predetermined heating temperature is 200°C to 400°C.
℃, and the extrusion pressure is 200 MPa or more.

The second feature of the present invention is that after the target polymeric material powder is degassed and sealed in a metal case, it is heated at a predetermined temperature, and then extruded by extrusion molding at a predetermined extrusion pressure. The predetermined heating temperature is 230°C to 400°C, the extrusion pressure is 200 MPa or more, and the orthogonal coordinate point of the extrusion pressure of 200 MPa at the heating temperature of 400°C and the heating temperature of 250°C Extrusion pressure 600MPL
The extrusion molding point is located within the orthogonal coordinate range above the extension of the straight line X that connects the orthogonal coordinate point.

(Example) Hereinafter, some of the examples of the present invention will be described in detail together with some of the comparative examples.

The polymer material powder to be described in detail below is an aromatic polyester thermoplastic resin powder, specifically Econol (registered trademark) described in the opening publication, which is conventionally difficult to mold. It is used as a filler for fluororesin powder, and the mechanical properties of the product after high temperature compression molding at 360°C to 370°C are as follows (
Hereinafter, this powder will be referred to as sample A).

Specific gravity 1.45, tensile strength 150-170 kg/ca
l, flexural modulus 7.9xlO' kg/co! , ``Thermal expansion coefficient 6.0 x 10-5, thermal conductivity 13 x 10-'
CaL/cm, sec"c + However, the present invention is also applicable to aromatic polyester thermoplastic resin powders other than those shown in the examples.

The target polymer material powder 20 is packed into a copper metal case 21 and vacuum degassed, then covered with a copper cap 23 having a taber 22, and made into a billet 26, as shown in FIG. Ru.

In this case, the metal case 21 has a conical part 24, and when there is a risk of damage to the billet, that is, the metal case 21 due to expansion during heating, a powder storage part 24 is provided at the axis of the conical part 240.
You can also make a thin hole to communicate between 5 and the outside air.
This narrow pore is sealed after heating.

The reason why the cap 23 is closed on the metal case 21 with the taber 22 is that although this may be done by welding, welding copper to copper requires a large amount of heat and there is a risk that the powder 20 may be exposed to high temperatures. − is desirable.

Note that both the metal case 21 and the cap 23 may be made of aluminum instead of copper.

Furthermore, after the material powder 20 is packed in a metal case 21 and vacuum degassed and sealed, it is heated at a predetermined heating temperature as detailed in the following example, and then extruded at a predetermined extrusion pressure. For example, an electric furnace can be used as the means,
As the extrusion means, other extrusion means including hydrostatic extrusion using a viscoplastic pressure medium such as heat-resistant grease can be used.

In each of the following examples, the full width of the die is 45° in hydrostatic extrusion.
The billet is made of copper and has an outer diameter of 67 tmφ and an inner diameter of 30 mφ, and several examples will be given when sample A is made into powder.

<Example 1> Reference numeral 1 shown in FIG. 1 is a billet of sample size 1, in which 82 g of the sample A was packed into a metal case, and after press-packing with a weight of about 5 tons in air several times, After evacuating in a vacuum for about 2 hours, a cap with a taber of about 20 tons is placed on top.

By heating this billet at 250°C for 2 hours and subjecting it to hydrostatic extrusion at an extrusion pressure of 880 MPL and an extrusion ratio of 9.3, a copper-coated extruded material, either a solid bar or pipe, can be obtained without any trouble during extrusion. I was able to do that.

The external appearance of the extruded material was sound, and even after removing the outer skin material (W4), a flesh-colored rod-shaped material with a constant diameter (22 m) was obtained.

Mechanical properties Bar material specific gravity 1.45, compressive strength 648 kg/a
a, tensile strength of 147 to 151 kg/d, and Rockwell hardness (HRR) of 65 to 69.

<Example 2> This is sample 11h2, numbered 2 in FIG. It was the same.

Mechanical properties Specific gravity 1.45, compressive strength 650 kg/cd 1
．． Tensile strength 15-155 kg/cIIl, HRR6
It was 7-69.

<Example 3> Sample No. 3, number 3 in Fig. 1, extrusion temperature 350°C
The extrusion pressure was 450 MPa, the extrusion ratio was 9.3, and the conditions of the extruded material were the same as in Example 1.

Mechanical properties Specific gravity: 1.45, compressive strength: 645 kg/c+J, tensile strength: 145-150 kg/aa, and HRR: 64-68.

<Example 4> This is sample N114 with reference numeral 4 in FIG. 1, and the extrusion temperature is 25
0°C, extrusion pressure cuff 20MPa, extrusion ratio 9.9,
The conditions of the extruded material were the same as in Example 1.

Mechanical properties Specific gravity 1.43, compressive strength 610 kg/cal, tensile strength 130-140 ksr/cj, HRR 60-63
Met.

<Example 5> This is sample Kan 5 with reference numeral 5 in FIG. 1, and the extrusion temperature is 400°C.
The extrusion pressure was 200 MPa, the extrusion ratio was 4.0, and the conditions of the extruded material were the same as in Example 1.

Mechanical properties Specific gravity: 1.43, compressive strength: 620 kg/C1a, tensile strength: 138-145 kg/ci, and HRR: 62-66.

<Example 6> The sample plate 6 is indicated by the reference numeral 6 in FIG. 1, and the extrusion temperature is 22.
0''C1 extrusion pressure was 656 MPa, extrusion ratio was 9.9 Te, and the conditions of the extruded material were the same as in Example 1.

Mechanical properties Specific gravity was 1.35 and compressive strength was 380 kg/cr&.

<Example 7> This is sample Arashi 7 shown by reference numeral 7 in FIG. 1, and the extrusion temperature is 24.
0°C, extrusion pressure 320MPa, extrusion ratio 9.9,
The conditions of the extruded material were the same as in Example 1.

Mechanical properties Specific gravity was 1.35 and compressive strength was 350 kg/cat.

Comparative Example 1> This is sample magnet 8 indicated by reference numeral 8 in FIG. 1, and the extrusion temperature is 30
Extrusion molding was carried out at 0° C., extrusion pressure of 150 MPa, and extrusion ratio of 2.0.

Although the extruded material of Comparative Example 1 had a sound external appearance, when the outer skin material (copper) was removed, the core material crumbled to pieces and a bar-shaped material could not be obtained.

<Comparative Example 2> The sample hole 9 is indicated by the reference numeral 9 in FIG. 1, and the extrusion temperature is 15.
Extrusion molding was carried out at 0°C, extrusion pressure of 580M, and extrusion ratio of 4.0.

The extruded material of Comparative Example 2 had a sound external appearance, but when the outer shell (copper) was removed, the core material was partially solidified but many granular parts were scattered.

<Comparative Example 3> The sample indicated by reference numeral 10 in FIG. 1 was 1ml0, and was extruded at an extrusion temperature of 170°C, an extrusion pressure of 377M-1, and an extrusion ratio of 3.3.

The extruded material of Comparative Example 3 had a sound appearance, but when the outer skin was removed, the powder was granular and not solidified.

Comparative Example 4> This is sample N11l shown by reference numeral 11 in Figure 1, extrusion temperature 420°C, extrusion pressure 300MPL, extrusion ratio 13.0.
Extrusion molded.

The condition of the extruded material of Comparative Example 4 was that the outer skin was blistered in the first half, and although the degree of blistering was smaller in the second half, the outer diameter was irregular. Furthermore, when the outer skin was removed, the surface of the core material was undulating and had cracks in some areas.

Mechanical properties Specific gravity: 1.41, compressive strength: 490 kg/cd, tensile strength: 110 kg/cot, HRR: 45-50.

Note that the shape of the billet, the type of powder, the amount filled, and the extrusion molding means are all the same for the samples Nos. 1 to N1111 described above.

Therefore, the following is clarified from the above-mentioned Examples 1 to 7 and Comparative Examples 1 to 4.

That is, as shown in FIG.
Extrusion pressure is 200MPL at heating temperature of 0℃~400℃
By performing high-temperature extrusion in the above manner, an extruded material made of heat-resistant and wear-resistant lightweight aromatic polyester thermoplastic resin powder can be obtained by high-temperature extrusion method, and this is the same as in Examples 5 and 6. For example, it can be used as mechanical sliding parts such as slide shoes.

In addition, as shown in Fig. 1, the extrusion pressure is 200 MPa or more at a heating temperature of 230°C to 400°C, and the orthogonal coordinate point of the extrusion pressure of 200 MPa at the heating temperature of 400°C and the extrusion pressure of 600 MPa at the heating temperature of 250°C.
The extruded materials formed within the orthogonal coordinate range above the extension line of the straight line Applications are expanded as mechanical structural parts.

(Effects of the Invention) According to the first feature of the present invention, an extruded material made of aromatic polyester resin powder, which was conventionally considered difficult to mold, can be extruded at a high temperature, and the characteristics of the resin can be effectively utilized. It can be used or utilized.

Furthermore, according to the second feature, an extruded material with better mechanical properties can be obtained in addition to the first feature described above.

[Brief explanation of the drawing]

FIG. 1 is a graph of the relationship between billet temperature (heating temperature) and extrusion pressure showing examples and comparative examples of the present invention, and FIG. 2 is a partially cutaway front view of the billet example. 20...Powder, 21...Case, 26...Billet. Figure 1 Figure 2 n

Claims (1)

[Claims] 1. The target polymeric material powder is degassed and sealed in a metal case, heated at a predetermined temperature, and then extruded at a predetermined extrusion pressure to obtain an extruded material. A high-temperature extrusion method for an extruded material made of aromatic polyester thermoplastic resin powder, wherein the predetermined heating temperature is 200°C to 400°C, and the extrusion pressure is 200 MPa or more. 2. The target polymeric material powder is degassed and sealed in a metal case, heated at a predetermined temperature, and then extruded at a predetermined extrusion pressure to obtain an extruded material, wherein the predetermined heating The temperature is 230°C to 400°C, the extrusion pressure is 200 MPa or more, and the orthogonal coordinate point of the extrusion pressure of 200 MPa at the heating temperature of 400°C and the extrusion pressure of 600 MPa at the heating temperature of 250°C.
A high-temperature extrusion method for an extruded material made of aromatic polyester thermoplastic resin powder, characterized in that extrusion molding is carried out within a range of orthogonal coordinates above an extension of a straight line X connecting the orthogonal coordinate points of