JPS6155674A - Separating claw for copying machine - Google Patents

Abstract

PURPOSE:To reduce the coefft. of friction so that a roll is not scratched and to improve the wear resistance and the rigidity at high temp. by molding a specified polyether ketone resin composition. CONSTITUTION:A polyether ketone resin composition consisting of 30-95wt% polyether ketone, 5-60wt% carbon fibers and 1-30wt% fluororesin is molded into a separating claw. Since the claw contains heat resistant thermoplastic polyether ketone as the base resin, complex after-treatment is not required after molding. The blended carbon fibers improve the rigidity at high temp. and the wear resistance, so the deformation of the claw due to wear is reduced. The generation of static electricity is prevented by the fibers, so a toner and dust stick hardly to the claw. The blended fluororesin reduces the coefft. of friction so as to prevent the scratch of a roll, and it can prevent the sticking of a toner and dust.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a separation claw for a copying machine formed by molding a polyetherketone resin composition containing carbon fibers and a fluororesin.

More specifically, the present invention relates to a separation claw for a copying machine made of a novel composition that can be injection molded and has excellent high-temperature rigidity, abrasion resistance, and non-adhesion of toner.

2. Description of the Related Art Currently, in electrostatic copying machines and the like, a heated roller fixing device is used to fix a toner image formed on copy paper. In this heating roller fixed fixing device, in order to prevent the copy paper that has passed the roller from wrapping around the roller and to ensure that the copy paper is ejected, the separating claw is set so that its tip is in contact with the outer peripheral surface of the roller. It is necessary to provide Therefore, this separating claw has a small frictional resistance between it and the roller to be in contact, so that the surface of the roller is not damaged, and the toner that has adhered little by little to the roller during the fixing operation is difficult to transfer and accumulate on the separating claw, so that it can be cleaned. be easy to apply, have sufficient mechanical strength, especially high temperature rigidity,
The shape of the tip is required to have properties such as sufficient summer dissipation.

Conventionally, as the above separation claws, there are known separation claws made of polyamideimide, separation claws made of polyamideimide coated with a fluororesin, and those made of a fluororesin.

Problems to be Solved by the Invention However, polyamide-imide-based materials have high toner adhesion properties, making it difficult to clean and remove accumulated toner, and also have a large coefficient of friction against rollers, easily damaging the rollers. Further, post-cure treatment after injection molding requires stepwise high-temperature treatment over a long period of time, which has drawbacks such as low mass productivity and high cost.

Furthermore, the separation claws, which have improved toner adhesion by coating the polyamide-imide separation claws with fluororesin, have a short service life because the fluororesin coating layer is easy to peel off, and the separation claws are in contact with the roller. Because the tip cannot be sharpened, the separation effect of the copy paper is insufficient, and heat treatment is required in the process of applying the fluororesin coating.
1. There are disadvantages such as high cost.

In addition, the separating claws, which are made of molded fluororesin, have low wear resistance and low high-temperature rigidity, so the tip of the separating claws tends to "sag" (deform) during the copy paper separation process. .

The present invention has low toner adhesion, has a small coefficient of friction against the roller, does not damage the roller, has high wear resistance, high temperature rigidity, is resistant to deformation, and does not require complicated post-processing after injection molding. The object of the present invention is to provide a separation claw for a copying machine that solves the above-mentioned problems.

Means for Solving the Problems The present invention is characterized by polyetherketone 80~
This separation claw for a copying machine is formed by molding a polyetherketone resin consisting of 95 wt% carbon fiber, 5 to 5 Q wt% carbon fiber, and 1 to 80 wt% fluororesin.

The polyetherketone used in the present invention preferably contains 1ζ repeating unit alone or together with other repeating units, and has an intrinsic viscosity of preferably 0.3 to 2.6, more preferably 0.5 to 1.8.

As other repeating units, ÷so, -σ0-, etc. may be contained in an amount less than 25 wt%, but a polymer containing more than 'l 5 wt% is not preferable because the above-mentioned properties of the polyetherketone are lost. Also, the intrinsic viscosity is 100 d of solution.
It is the intrinsic viscosity measured at 25° C. for a polymer solution in concentrated sulfuric acid with a density of 1.84 f/d containing 0.1 f of polymer. The intrinsic viscosity was measured using a viscometer with a solvent flow time of about 2 minutes. This intrinsic viscosity directly corresponds to the molecular weight of the polymer.

The intrinsic viscosity of the polyetherketone according to the present invention is 0.8
The intrinsic viscosity is preferably from 0.5 to 2.6, more preferably from 0.5 to 1.8, but if the intrinsic viscosity is less than 0.8, the molecular weight is low, resulting in low heat resistance, brittleness, and insufficient strength. . If the intrinsic viscosity exceeds 2.6, the melt viscosity is high, resulting in insufficient fluidity during melt molding, making it impossible to obtain a good molded product. It is preferable that the intrinsic viscosity is in the range of 0.8 to 2.6 because it provides good surface appearance and excellent physical properties and processability.

The polyetherketone can be obtained by the method disclosed in JP-A-54-90296.

The carbon fiber used in the present invention may be any of acrylonitrile-based, pitch-based, cellulose-based, etc.
It is preferable to have a diameter of 5 to 20μ and a fiber length of 0.1 to 1Q+ot, but it is preferable to use fibers with a length of about 6mm, which are usually used for filling sphere fat, or roving, or roving of 0.1 to 0. .4 Short fibers of 100% strength are used.

In particular, short fibers with a length of about 0.1 to 0.4M have a high improvement effect on abrasion resistance, high temperature rigidity, etc. when blended with polyetherketone, and are used as separation claws for copying machines. It is more preferable because it has the advantage that when it is heated, there is little wear and deformation of itself, and there is very little damage to the heating roller surface that comes into contact with the claws.

The surface of the carbon fibers can be treated with a treatment agent such as epoxy resin, polycarbonate resin, polyacetal resin, etc., but the carbon fibers are not limited thereto.

Examples of the carbon fiber include Magnamite AS1 Magnamite HMS (manufactured by Vercules), Trading Card Ta
Examples include oQA (manufactured by Toshisha Co., Ltd.), Besphite HTA, Pesphite 1000 (manufactured by Toho Rayon Co., Ltd.), and Kureka M1 Kureka C (manufactured by Kenbetsu Kagaku Kogyo Co., Ltd.).

The fluororesin used in the present invention refers to a synthetic polymer containing ζ fluorine atoms (F) in the molecule, examples of which include tetrafluoroethylene resin, tetrafluoroethylene resin, and tetrafluoroethylene resin. - perfluoroalkyl vinyl ether copolymer resin, tetrafluoroethylene-hexafluoropropylene copolymer resin, tetrafluoroethylene-ethylene copolymer resin,
Examples include trifluorochloroethylene resin, vinylidene fluoride resin, and the like.

Among the fluororesins, tetrafluoroethylene resin (polytetrafluoroethylene) has a melting point of about 380°C, but has a high melt viscosity and does not flow even above the melting point. Therefore, the dispersion state in the composition is less likely to change depending on the molding processing conditions, and the properties, mechanical strength, abrasion resistance, toner non-adhesion, etc. of the composition are less likely to change, which is preferable.

As the tetrafluoroethylene resin, lubricant edge PTFE powder with an average particle size of less than 20μ is preferable, and commercially available examples include Fluon L169, Li2O, L171.
(ICI!!ri, LeBron ■L-2, [, -5, L,
D~1 (manufactured by Daikin Industries), Teflon ■TLP-10
, TLP-10F-1 (manufactured by DuPont).

The blending amount is 80 to 95 wt% polyether ketone.
, fiber 5-60wt% and fluororesin 1-3Qwt%
It is effective to use a composition in which the total amount of carbon fibers and fluororesin is 5 to 70 wt% of the total resin composition.

That is, the total amount of carbon fiber and fluororesin exceeds 79 wt% of the total resin composition, and the amount of polyether ketone exceeds 3Q.
When it is less than wt%, dispersion in the melt mixer is insufficient, a uniform composition cannot be obtained, the fluidity of the resin composition is lost, and molding becomes difficult. In addition, when the total amount of carbon m#+ and fluororesin is less than 5 wt%, the rigidity as a separation claw,
Insufficient wear resistance.

In addition, the total amount of carbon fiber and fluororesin is 5 to 7 Qwt%.
However, if the amount of carbon fiber is less than 5 wt%, the required rigidity of the separating claw is insufficient, and conversely, if the amount of fluororesin is less than 1 wt%, the wear resistance and toner resistance are insufficient. Adhesion is not sufficient.

Furthermore, if the amount of the fluororesin exceeds 3 Qwt%, the strength will be significantly lowered, and if the carbon fiber claw exceeds 5Qwt%, the fluidity of the composition will decrease significantly, which is not preferable.

The means of blending the composition used in the present invention is not particularly limited. It is possible to feed polyetherketone, carbon fiber, and fluororesin separately to a melt mixer, or these raw materials are premixed using a mortar Henschel mixer, ball mill, ribbon blender, etc. and then melted. It can also be fed to a mixer.

In addition, antioxidants and heat stabilizers,
One or more conventional additives such as ultraviolet absorbers, lubricants, mold release agents, colorants such as dyes and pigments, flame retardants, flame retardant aids, and antistatic agents can be added.

There are no particular limitations on the method for producing the separated nails from the above composition. By injection molding machine, cylinder temperature f1160~4
A molding method selected from conditions of 40°C and a mold temperature of 100 to 200°C is highly effective in mass production and is preferred, but it can also be obtained by machining an intermediate molded product obtained by compression molding, extrusion molding, etc. .

The mold temperature in injection molding is 150-200℃
When the temperature is about 100%, a molded article with a high degree of crystallinity of the polyetherketone can be obtained, and properties such as high temperature rigidity are good, so it is preferable. In addition, if a molded product with insufficient crystallinity is obtained, 20
The degree of crystallinity can be improved by annealing at 0 to 300°C for several minutes to several hours.

Function: The separation claw for a copying machine according to the present invention contains, as a base resin,
Since heat-resistant thermoplastic polyetherketone is used, complicated post-treatment after molding is unnecessary.

In addition, since carbon fiber is blended, it has high high temperature rigidity, excellent wear resistance, and minimal wear deformation of the nail itself. Furthermore, the conductive effect of the carbon W4 fibers prevents the generation of static electricity, and reduces the adhesion of toner and dust.

Furthermore, the combination of fluorine W fat has the effect of further reducing the coefficient of friction with the roll, preventing damage to the roll, and also preventing adhesion of toner and the like.

EXAMPLES The present invention will be explained below with reference to Examples, but these are merely illustrative and the present invention is not limited thereto.

Examples 1 to 5 (Polyetherket) having an intrinsic viscosity of 0.8:
/ carbon taH (mMA diameter 10.5 tt, am length 0
, 87 Mll, manufactured by Kenbetsu Kagaku Kogyo Co., Ltd. Reka M-204F
), tetrafluoroethylene resin, (Fluon L169, I
CI Corporation) were mixed with the composition shown in Table 1 and melted and kneaded at a temperature of 860°C using a twin-screw extruder (PCM-f30 manufactured by Ikegai Iron Works), and then the strands were water-cooled and cut to obtain pellets. .

The obtained pellets are injection molded using Sumitomo Nekool 47.
728 injection molding machine, cylinder temperature 880℃, mold temperature tSO℃), bending test piece, wear ring (outer diameter 25.5m
, inner diameter 20H1 height 15H) was obtained.

Flexural modulus was measured in accordance with ASTM D-790.

The sliding characteristics were tested using a Suzuki abrasion tester using the above-mentioned wear ring at a pressure of 6 kg/d and a speed of 40 m1 m1n.
The mating material was 355C under CD conditions, and after 2 hours of break-in operation, 20 hours of sliding was performed, and the friction coefficient and wear coefficient were measured. The results are shown in Table 1.

Comparative Examples 1 to a Using the polyether ketone, carbon fiber, and tetrafluoroethylene resin used in Examples 1 to 5, similar studies were carried out for various blending ratios outside the effective range of these compositions. went.

The results are shown in Table 1.

As shown in Table 1, the composition used in the present invention has high rigidity at room temperature and high temperature, and is difficult to deform. In addition, it has a low coefficient of friction, little wear on itself, and does not damage the mating material, exhibiting extremely well-balanced characteristics, and has performance suitable for separation claws for copying machines.

Example 5 Using the composition of Example 2, a separation claw for a copying machine was molded by injection molding. No heat treatment was performed after molding.

The resulting separating claw was attached to a heating roller fixing device of a copying machine (a predetermined position in contact with the heating roller fixing device).

A heating roller whose surface was coated with PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin) was operated, and its function as a separating claw was evaluated.

The tip of this separating claw is precisely molded, and it reliably separates the copy paper. It also does not damage the rollers that come into contact with it, and has less toner stains (easy to clean and has a long service life). It was long and fully satisfied the characteristics required for separation claws.

Example 6 Using the composition of Example 4, a separating claw for a copying machine was molded by injection molding, and the same evaluation as in Example 5 was conducted, and it showed good characteristics as a separating claw.

Comparative Example 4 When the same test as in Example 5 was conducted using the composition of Comparative Example 1, the rollers that were in contact with the rollers were damaged and had a lot of toner stains attached, making cleaning difficult.

Comparative Example 5 When the same test as in Example 5 was conducted using the composition of Comparative Example 2, "settling" at the tip of the separating claw was large and copy paper separation was insufficient.

Effects of the Invention As stated above, the present invention provides a molecule 1lTt for copying machines.
By using a composition consisting of polyetherketone, carbon fiber, and fluororesin, there is no need for complicated post-processing after molding, making it excellent for mass production, with less wear and deformation of the claw itself, and less damage to the opposing rolls. This has the effect of significantly reducing toner adhesion, contributing to the technological progress of office equipment such as copying machines that have separate heavy machine grooves, and promoting their widespread use.

Claims (1)

[Scope of Claims] A separation claw for a copying machine formed by molding a polyetherketone resin composition consisting of 30 to 95 wt% polyetherketone, 5 to 60 wt% carbon fiber, and 1 to 30 wt% fluororesin.