JP2019099640A - Resin composition, manufacturing method therefor, and molded article for power transmission consisting of the same - Google Patents

Abstract

To provide a resin composition excellent in physical properties at a high temperature, and further improved excellent abrasion resistance (burning and scratching of an opposite material), and a molded article for power transmission consisting of the same.SOLUTION: There are provided (1) a resin composition consisting of a thermoplastic resin and an aromatic polyamide fiber, in which the aromatic polyamide fibber satisfies following requirements, (I) fiber length of the aromatic polyamide fiber is in a range of 0.5 to 5.0 mm, (II) 5 to 30 wt.% of carbon black is contained in 100 wt.% of the aromatic polyamide fiber, and (III) 5 to 30 pts.wt. of the aromatic polyamide fiber is contained in 100 pts.wt. of the aromatic polyamide fiber, (2) a manufacturing method of the resin composition described in the (1), including a process for melting and mixing the thermoplastic resin and the aromatic polyamide fiber, and (3) a molded article for power transmission consisting of the resin composition described in the (1).SELECTED DRAWING: None

Description

  The present invention relates to a fiber-reinforced resin composition for power transmission which is less likely to be burned and damaged by a mating material even when parts are in contact with each other and is suitably used for a power transmission part or the like.

  The resin composition is superior in processability to metals, and in particular, the fiber-reinforced resin composition has excellent features such as light weight, high mechanical properties, easy processability, corrosion resistance, etc. In applications, it is beginning to be used as a member for power transmission. For example, in patent documents 1 and patent documents 2, the fiber reinforced resin molded article which reinforced thermoplastics resin with carbon fiber and organic fiber is mentioned.

  However, when the power transmission member is driven at high rotation, there is a problem that the temperature becomes high due to the friction with the partner material and the partner material is damaged by the inorganic filler (for example, carbon fiber or glass fiber).

Patent No. 5633660 gazette JP, 2009-24057, A

  An object of the present invention is to provide a resin composition which is excellent in physical properties at high temperature and further improved in excellent abrasion resistance (burning and damage of a mating material), and a molded article for power transmission made therefrom.

The present invention
(1) A resin composition comprising a thermoplastic resin and an aromatic polyamide fiber, wherein the aromatic polyamide fiber satisfies the following requirements.
(I) The fiber length of the aromatic polyamide fiber is in the range of 0.5 to 5.0 mm.
(II) 5 to 30% by weight of carbon black is contained in 100% by weight of the aromatic polyamide fiber.
(III) 5 to 30 parts by weight of the aromatic polyamide fiber is contained in 100 parts by weight of the resin composition.
(2) The method for producing a resin composition according to (1), including the step of melt-kneading a thermoplastic resin and an aromatic polyamide fiber.
(3) A molded product for power transmission comprising the resin composition according to (1) above.

  According to the present invention, there are provided a resin composition having improved excellent abrasion resistance (burn and damage of a mating material), and a power transmission molded article comprising the resin composition.

  The resin composition of the present invention contains a thermoplastic resin and an aromatic polyamide fiber containing carbon black.

  The thermoplastic resin used for the resin composition of the present invention is not particularly limited, and examples thereof include polyolefin resin, polystyrene resin, polyamide resin, halogenated vinyl resin, polyacetal resin, saturated polyester resin, polycarbonate resin, polyarylsulfone resin, Polyaryl ketone resin, polyphenylene ether resin, polyphenylene sulfide resin, polyaryl ether ketone resin, polyether sulfone resin, polyphenylene sulfide sulfone resin, polyarylate resin, polyamide resin, liquid crystal polyester resin, fluorine resin and the like. Two or more of these can also be used. Among these, polyamide resins and polyphenylene sulfide resins (PPS resins) are preferable from the viewpoint of heat resistance that can be used in a wide range from low temperature to high temperature.

  Further, the melting point of the thermoplastic resin used in the present invention is preferably 200 to 300 ° C., and particularly preferably in the range of 220 to 260 ° C. However, although the heat resistance of the fiber reinforced resin obtained can be improved as the melting point is higher, the processability tends to decrease if it is too high. From such a balance of heat resistance and processability, polyamide resins are particularly useful.

  More specific examples of the polyamide resin include polycaproamide (nylon 6), polyhexamethylene adipamide (nylon 66), polycaproamide / polyhexamethylene adipamide copolymer (nylon 6/66), poly Tetramethylene adipamide (nylon 46), polyhexamethylene sebacamide (nylon 610), polyhexamethylene dodecamide (nylon 612), polyhexamethylene terephthalamide / polycaproamide copolymer (nylon 6T / 6), polyhexa Methylene adipamide / polyhexamethylene terephthalamide copolymer (nylon 66 / 6T), polyhexamethylene adipamide / polyhexamethylene isophthalamide copolymer (nylon 66 / 6I), polyhexamethylene adipamide / polyhexamethyl Terephthalamide / polyhexamethylene isophthalamide copolymer (nylon 66 / 6T / 6I), polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (nylon 6T / 6I), polyhexamethylene terephthalamide / polydodecaneamide copolymer (nylon 6T / 12), polyhexamethylene terephthalamide / poly (2-methylpentamethylene) terephthalamide copolymer (nylon 6T / M5T), polyxylylene adipamide (nylon XD6), polynonamethylene terephthalamide (nylon 9T) and These copolymers etc. are mentioned. Two or more of these may be used. Among these, nylon 6 and nylon 66 are more preferable.

  The resin composition of the present invention is essential to contain an aromatic polyamide fiber containing carbon black in addition to the above-mentioned thermoplastic resin.

  And as an aromatic polyamide fiber used for the resin composition of this invention, the aromatic ring which comprises main frame | skeleton is couple | bonded by an amide bond. Here, the aromatic groups to be fibers may be the same or different aromatic groups. The hydrogen atom of the aromatic group may be substituted with a halogen atom, a lower alkyl group, or a phenyl group (hereinafter, "aromatic polyamide fiber" may be referred to as "aramid fiber").

  Particularly preferable aromatic polyamide fibers are fibers in which 80% by mole or more, preferably 90% by mole or more of the repeating units constituting the polyamide are aromatic polyamides. Further, as the aromatic polyamide fiber, there are a para-based aromatic polyamide fiber in which an aromatic ring is bonded at a para position, and a meta-based aromatic polyamide fiber in which an aromatic ring is bonded at a meta position. Although it is used, it is preferable that it is a para-type aromatic polyamide fiber excellent in strength.

  The para-based aromatic polyamide fiber used in the present invention is poly-p-phenylene terephthalamide or a fiber obtained by copolymerizing a third component therewith. As an example of the polyparaphenylene terephthalamide copolymer, copolyparaphenylene-3.4'-oxydiphenylene terephthalamide shown in the following formula (1) is exemplified.

(Wherein, m and n represent positive integers)
Among the para-based aromatic polyamide fibers, examples of fibers made of polyparaphenylene terephthalamide include “Twalon” (manufactured by Teijin Towalon Co., Ltd.), “Kevlar” (manufactured by DuPont Co., Ltd.) and the like.

  Moreover, as a fiber which consists of copoly para phenylene * 3,4'- oxydiphenylene terephthalamide represented by said Formula (1), "Technola" (made by Teijin Ltd.) is mentioned.

(From Japanese Patent Application Laid-Open No. 9-143821)
The para-based aromatic polyamide fiber used in the present invention contains carbon black, and any known carbon black can be used as the carbon black, for example, acetylene black (Denka black, "Denka black") , Oil furnace black, thermal black, channel black, ketjen black and the like. These can be usually dispersed in a matrix polymer and used as a fine powder. Here, the primary particle size of carbon black is preferably 10 to 100 nm.
Here, the primary particle size refers to the particle size before the particles are aggregated to form secondary particles.

  In the case of an anisotropic solution such as poly (p-phenylene terephthalamide), the polymer forms a liquid crystal in the dope to form a dense structure, and therefore, the size needs to be small in order to incorporate an additive such as carbon black. . On the other hand, in the isotropic solution, the incorporation of the additive is easy because the polymer structure in the dope is loose, and the problem of the additive size is small. However, for the following reasons, it is preferable to set the primary particle size of carbon to be added to 10 to 100 nm.

  If the primary particle size is smaller than 10 nm, the surface energy is high and aggregation is likely to occur, so that it is necessary to use an organic dispersion auxiliary as a countermeasure, and as a result, the dispersion auxiliary is thermally decomposed in the heat drawing process. There is an adverse effect on the spinning properties.

  When the primary particle size exceeds 100 nm, the secondary structural unit, which is also called a secondary structural unit or a secondary structural unit, becomes a defective foreign substance as a coarse aggregate in the fiber, which causes fuzz or breakage due to single yarn breakage. Absent.

Here, in order to produce such a para-based aromatic polyamide fiber containing carbon black, carbon black may be added to the para-aramid-containing dope, and this may be wet-spinning and drawn according to a conventional method.
(Hereinafter, "aromatic polyamide fiber" may be referred to as "aramid fiber").

  The amount of carbon black added to the para-aramid fiber is 5 to 30% by weight, preferably 10 to 20% by weight, in 100% by weight of the para-aramid fiber. If it is less than 5% by weight, the effect of diffusing the heat generated by the friction with the opposite material in the fiber direction is reduced. On the other hand, if it exceeds 30% by weight, physical properties such as the strength of the aromatic polyamide fiber may be lowered.

  The fiber length of the aramid fiber used in the present invention needs to be 0.5 to 5.0 mm, preferably 1.0 to 3.0 mm, and more preferably 1.2 to 2.5 mm.

  If the fiber length of the aramid fiber is shorter than 0.5 mm, the impact resistance of the resin composition tends to decrease, and the fiber tends to fall off. Conversely, if the fiber length is longer than 5.0 mm, the resin composition As the number of aramid fibers per cross sectional area at the time of breakage of the product decreases, the impact resistance tends to decrease as well.

  As a method for cutting aramid fibers, any cutter capable of cutting fibers may be used. Specifically, it is preferable to cut using a rotary cutter, a guillotine cutter or the like.

  The single fiber fineness of the aramid fiber is in the range of 0.1 to 5.5 dtex, preferably 0.3 to 2.5 dtex.

  If the single fiber fineness of aramid fibers is less than 0.1 dtex, there are many difficulties in yarn production technology, and it is difficult to stably produce fibers of good quality due to wire breakage and fuzz generation. It is not preferable because the cost also increases. On the other hand, if the denier is more than 5.5 dtex, the mechanical properties of the fiber, particularly the reduction in strength, become large, and the fiber is uniformly dispersed in the molded product when it is formed into a fiber-reinforced resin molded product. It is not preferable because it becomes difficult.

  The content of the aramid fiber to the resin composition of the present invention is preferably 5 to 30 parts by weight, more preferably 8 to 25 parts by weight, and still more preferably 10 to 20 parts by weight in 100 parts by weight of the resin composition.

  When the content of the aramid fiber is too small by 5 parts by weight, sufficient impact resistance can not be obtained, and conversely when it is more than 30 parts by weight, the fibers, particularly long aramid fibers in the fiber length are uniformly contained in the resin. It will be difficult to disperse.

  Furthermore, other components may be contained in the resin composition of the present invention as long as the object of the present invention is not impaired. Examples of other components include inorganic fillers other than carbon fibers, flame retardants, conductivity imparting agents, crystal nucleating agents, ultraviolet light absorbers, antioxidants, damping agents, antibacterial agents, insect repellents, deodorants, coloring Examples thereof include an inhibitor, a heat stabilizer, a mold release agent, an antistatic agent, a plasticizer, a lubricant, a colorant, a pigment, a dye, a foaming agent, an antifoaming agent, and a coupling agent.

  The resin composition of the present invention is produced by melt-kneading a polyamide fiber containing carbon black with a thermoplastic resin.

  And as a manufacturing method of the resin composition of this invention, the melt-kneading system by a twin screw is preferable.

  As the melt-kneading method, the raw materials constituting the resin composition of the present invention are uniformly blended by a known blending method, charged into the feed port (hopper port) of the twin screw extruder, and fed into the cylinder. Do. Then, the cylinder temperature, screw rotation speed, and discharge amount are set to appropriate conditions, and melt kneading is performed with a twin-screw extruder.

As a method of feeding the raw material into the cylinder, a side feeder is also preferable.
In particular, it is preferable to use a side feeder to supply a fibrous or layered raw material that is prone to breakage, cutting, and cracking due to shearing during melt-kneading.

  Next, the melt-kneaded resin composition is drawn from the die in a strand shape, and then cooled and solidified by passing through a water tank, and cut by a pelletizer to obtain pellets of the resin composition, the resin composition of the present invention Get things.

  Furthermore, the resin composition of the present invention can be subjected to a process of melting and molding to obtain a molded article, and as a molding method, a fiber-containing resin composition such as pellets is directly press-molded or the like. Although it is good, it is preferable to carry out re-melting and injection molding.

  The molded article of the present invention obtained in this manner can significantly improve the abrasion resistance at high temperatures (burning of the opposite material, damage to the opposite material) and is preferably used particularly as a resin component for power transmission. it can.

  The present invention will be specifically described by way of the following examples. However, the present invention is not limited thereby. The evaluations and characteristic values in the following examples were determined by the following measurement methods.

(1) Aramid Fiber Content Rate 1.0 g of the resin composition was added to formic acid (88%) and allowed to stand at room temperature for 24 hours or more to dissolve the resin component. The resultant was filtered, and formic acid was washed with water and dried to form a residue for content measurement.

(2) Fiber Length Regarding the residue for measuring the fiber content after filtration obtained in the above (1), the residue is put in a petri dish, ethanol is added, and the fiber length of aramid fiber is dispersed by ultrasonic wave, Using an optical microscope (DEGITAL MICROSCOPE VHX-1000) manufactured by Keyence Corporation, 400 fibers were measured to obtain an average of each fiber length.

(3) Slideability;
The slidability of the present invention was evaluated by the following method for the temperature of the sliding surface (baking of the mating material) and the surface roughness (corrosion) of the mating material.

Sliding surface temperature (baking of mating material)
It was carried out by a thrust cylinder type wear test method. A test piece prepared from the obtained resin composition and an aluminum cylinder are rubbed together under the conditions of contact surface pressure: 9.8 MPa, sliding speed: 0.5 m / s, test time: 30 min, and sliding by thermography The surface temperature was measured.
The actual temperature of the sliding surface was evaluated as ◎ for less than 80 ° C., less than 80 to 100 ° C. for ○, and 100 ° C. or more for x.

Surface roughness of mating material (scratchability)
Moreover, after the said test, the surface roughness of the other material (tube made from aluminum) was measured with the laser microscope.
When the surface roughness was less than 8 μm, it was evaluated as ◎, when less than 8 to 10 μm, it was evaluated as ○, and when more than 10 μm, it was evaluated as x.

Example 1
Copolyparaphenylene .3 containing 5% by weight of carbon black (manufactured by Dainichi Seika Kogyo Co., Ltd., MPS-1504B1ack (T) primary particle size: 30 nm) as aromatic polyamide fiber in 100% by weight of the aromatic polyamide Three, 4′-oxydiphenylene terephthalamide fibers (manufactured by Teijin Limited, fiber diameter 12 μm, fineness 1,670 dtex, number of fibers 1000) were combined and twisted 35 times / m in the S direction. Subsequently, this twist cord is continuously immersed in a solution obtained by diluting a polyurethane resin ("Bondic 8510" manufactured by DIC Corporation) with ion exchange water to a solid concentration of 20% by weight, and the solution is dipped in a dryer at 150 ° C for 1 minute. Through the process, an aromatic polyamide fiber having a treatment agent adhesion amount of 13% by weight was obtained. Next, this aromatic polyamide fiber was cut to a length of 3 mm with a guillotine cutter to obtain a copolymerized aromatic polyamide fiber short fiber.
On the other hand, polyamide 66 resin (melting point 265 ° C.) was prepared as a thermoplastic resin.

  Subsequently, 85 parts by weight of the polyamide resin 66 was supplied to the supply port of the twin-screw extruder, and 15 parts by weight of the aromatic polyamide fiber was supplied from the side feeder to carry out melt kneading. The cylinder temperature of the extruder was 280 to 300 ° C., the screw speed was 300 rpm, and the discharge rate was 35 kg / hour.

  Next, the molten resin composition was taken out of a die in a strand shape, and was cooled and solidified by passing through a water bath, and was cut with a pelletizer to obtain pellets of the resin composition to obtain a resin composition for power transmission.

Using the obtained pellet (resin composition), a molded article (sliding member) was produced using an injection molding machine, and the fiber content and fiber length of this molded article were determined. In addition, the impact strength and the condition of the sliding surface were evaluated.
Both baking and scratching on the other material were good. The evaluation results are shown in Table 1.

Example 2
Copolyparaphenylene 3,4'-oxydiphenylene terephthalamide containing 10% by weight of carbon black (manufactured by Dainichi Seika Kogyo Co., Ltd., MPS-1504B1ack (T) primary particle size: 30 nm) as an aromatic polyamide fiber A molded article (sliding member) was produced and evaluated in the same manner as in Example 1 except that the fiber was changed.
Both baking and scratching on the other material were good. The evaluation results are shown in Table 1.

[Examples 3 to 5]
In the same manner as in Example 1, except that the carbon black was changed to copolyparaphenylene-3,4′-oxydiphenylene terephthalamide fiber containing 15, 18 and 22% by weight as an aromatic polyamide fiber, respectively. An article (sliding member) was produced and evaluated.
Both baking and scratching on the other material were good. The evaluation results are shown in Table 1.

Comparative Examples 1 and 2
A molded article (the same as in Example 1 except that the carbon black was changed to copolyparaphenylene-3,4′-oxydiphenylene terephthalamide fibers containing 0 and 40 wt%, respectively) as the aromatic polyamide fibers The sliding member was manufactured and evaluated. The evaluation results are shown in Table 1.
In Comparative Example 2, the amount of carbon black was too large to be able to be spun.

[Examples 6, 7 and Comparative Example 3]
A molded article (sliding member) was produced and evaluated in the same manner as in Example 1 except that the amount of the aromatic polyamide fiber was changed to 5, 25 and 40 parts by weight. The evaluation results are shown in Table 1.
The composition of Comparative Example 3 could not be prepared because the content of the polyamide fiber was too high.

Comparative Example 4
A molded article (sliding member) was produced and evaluated in the same manner as in Example 1 except that the PAN-based carbon fiber was changed to 15 parts by weight instead of the aromatic polyamide fiber. The evaluation results are shown in Table 1.
The surface roughness (with scratches) of the mating material was not good.

Claims (6)

A resin composition comprising a thermoplastic resin and an aromatic polyamide fiber, wherein the aromatic polyamide fiber satisfies the following requirements.
(1) The fiber length of the aromatic polyamide fiber is in the range of 0.5 to 5.0 mm.
(2) 5 to 30% by weight of carbon black is contained in 100% by weight of the aromatic polyamide fiber.
(3) 5 to 30 parts by weight of the aromatic polyamide fiber is contained in 100 parts by weight of the resin composition.   The resin composition according to claim 1, wherein the aromatic polyamide fiber is a fiber containing copolyparaphenylene 3,4'-oxydiphenylene terephthalamide.   The resin composition according to claim 1 or 2, wherein the melting point of the thermoplastic resin is 200 to 300 ° C.   The resin composition according to any one of claims 1 to 3, wherein the thermoplastic resin is a polyamide resin.   The manufacturing method of the resin composition as described in any one of Claims 1-4 including the process of melt-kneading a thermoplastic resin and co-polymerization aromatic polyamide fiber. The molded article for power transmissions which consists of a resin composition as described in any one of Claims 1-4.