JPS63178279A - Separating claw for copying machine - Google Patents

Abstract

PURPOSE:To provide superior mechanical strength and superior rigidity at high temp. and to prevent paper jamming or separation in a wrong direction by using polyphenylene sulfide resin, glass fibers of <=6mum diameter and thermosetting resin. CONSTITUTION:A resin compsn. consisting of 25-80wt.% polyphenylene sulfide resin, 19-74wt.% glass fibers of <=6mum diameter and 1-40wt.% thermosetting resin having at least one selected from epoxy, carboxyl, hydroxyl, phenoxy, methylol or amino groups, e.g., phenol or epoxy resin is formed into a separating claw having superior mechanism strength. The surface of the claw has superior smoothness, lubricity and nonadhesiveness to a toner and maintains the nonadhesiveness over a long period. The resin compsn. has such formability that the desired radius of curvature is easily provided to the tip of the claw.

Description

[Detailed Description of the Invention] [Industrial Field of Application] [Prior Art] Conventionally, copying machines are roughly divided into two types: dry type and wet type. After converting the electrostatic latent image formed on the surface of the photosensitive drum into a toner image, this toner image is transferred to the paper surface supplied from the paper feed cassette, and the transferred toner image is further fixed on the paper surface. A mechanism is incorporated in which the surface is heated and pressurized by a heated fixing roller to fuse the toner image and paper fibers so that they do not easily separate.

In order to ensure that the copy paper that has passed through the fixing roller is ejected without being wrapped around the roller, a separation claw is used to scoop up the edges of the copy paper while its tip is placed on the outer circumferential surface of the roller. .

Therefore, in such a separation claw, the frictional resistance against the outer peripheral surface of the roller is small and the surface is not damaged.
In order to satisfy the characteristics essential for such a separating claw, it is necessary to have sufficient mechanical strength, especially high temperature rigidity, sufficient precision in the shape of the tip, and not to stick toner. , heat-resistant resins such as polyimide, polyamide-imide, polyphenylene sulfide, polyetheretherketone, polysulfone, polyetherimide, aromatic polyamide, aromatic polyester, heat-resistant fibers such as glass fiber, potassium titanate fiber, carbon fiber, etc.
Furthermore, a material made from a composition containing a fluororesin has been proposed. For example, resins such as polyphenylene sulfide, polyether ketone, and polyamide have an average fiber length of 5 to 30 μm and an average fiber diameter of 0.2 to 0.0 μm.
Composition containing 5 μm short fiber reinforcing agent (potassium titanate whiskers, etc.) (Japanese Patent Application Laid-open No. 182071/1983)
, a composition in which heat-resistant fibers such as potassium titanate fibers or asbestos fibers, or inorganic fillers such as mica and talc are added to thermoplastic polyether aromatic ketone such as polyetheretherketone resin (JP-A-61-1999). '!
No. 7575), also polyimide, polyamideimide,
A composition containing a hard heat-resistant resin such as phenol, a tetrafluoroethylene resin, and in some cases glass (Japanese Patent Laid-Open No.
6-132368), a composition comprising polyetherketone, potassium titanate fiber, and a fluororesin (JP-A-60-257467), a composition comprising polyetherketone, carbon fiber, and a fluororesin (JP-A No. 60-257467), a composition comprising polyetherketone, carbon fiber, and fluororesin (JP-A No. 61-
No. 55674) and the like have been disclosed. However, JP-A No. 61--t 82071, same 2757
Separation claws using short fibers such as potassium titanate fibers as reinforcing agents, as described in No. 5 and No. 25746.7, are inferior in mechanical strength such as bending strength and impact strength, and have poor rigidity at high temperatures. As a result, the tip of the separation claw may become chipped or bent due to the resistance of the fixed paper passing through it, making it impossible to perform its separation function.
As in No. 132368 and No. 61-182071, glass powder or glass peas causes the same problem as the short fiber reinforcing agent, and glass fiber or carbon fiber has a large surface roughness when forming the separation claw. The radius of curvature of the tip becomes large and often exceeds 0.1 mm,
Not only will it not be possible to obtain a good tip shape and the fixing paper will not be scooped up smoothly, but it will also cause problems in the separation direction. Furthermore, even those containing solid lubricants such as fluororesin, as disclosed in JP-A No. 56-132368, JP-A No. 60-257467, and JP-A No. 61-55674, have insufficient lubricity and non-adhesive properties. Paper jams or claw marks are likely to occur due to long-term continuous use or depending on the type of toner used.

[Problem that the invention seeks to solve]

In this way, with the conventional technology, it is easy to obtain heat resistance that does not cause a decrease in rigidity at high temperatures, excellent mechanical strength such as impact strength or bending strength of the nail tip, and a preferable radius of curvature of the nail tip. There has been a problem in that a separation claw that is excellent not only in moldability and smoothness of the surface of the molded product, but also in lubricity, non-adhesiveness to toner, and the durability of this non-adhesive property has not been obtained. .

[Means for solving problems]

In order to solve the above problems, this invention uses 25 to 80% by weight of polyphenylene sulfide resin and a fiber diameter of 6 μm.
consisting of 19 to 74% by weight of glass fibers having a diameter of less than This method employs a method of using a resin composition as a separation claw for a copying machine. The details will be described below.

First, the polyphenylene sulfide resin of this invention is used as a matrix resin, and exhibits excellent heat resistance with a heat distortion temperature of 260°C or higher, and has a melt viscosity that is higher than that of other engineering plastics. It is a preferred resin because it has low moldability and excellent moldability and fillability with fillers. The reason why the blending amount of this resin is 25 to 80% by weight is that if the amount is less than 25% by weight, the moldability will be extremely poor, and if the amount is more than 80% by weight, the amount of reinforcing agent will decrease and practical strength cannot be obtained. This is because it will not be possible to provide for As a general-purpose molding material, 40% or 60% by weight of glass fiber with an average fiber diameter of 13 μm is added to polyphenylene sulfide resin.
Mixed products are commercially available, and when the surface roughness of these molded products is measured, a roughness of 5 to 10 μm (RmaX) is observed, and the radius of curvature of the tip of the separating claw is 0.1 m.
It is necessary to have an accuracy of 0.05 mm or less, preferably 0.05 mm or less, but such accuracy is difficult to obtain with the above-mentioned glass fibers. Therefore, it is important that the diameter of the glass fibers to be blended is 6 μm or less. If such fibers are used, the surface roughness of the molded product will be 1 to 3 μm or less, and the radius of curvature of the separation claw will be 0.05mm
With the following results, a molded product with a tip shape and smoothness that sufficiently functions as a separating claw can be obtained. Furthermore, if we consider the rigidity and mechanical strength of the separating claw at high temperatures,
Glass fiber length is 0.1 mm or more, preferably 0.5 mm
mm or more, and the blending amount is also 19 mm or more.
Weight % or more is desirable. However, if the amount exceeds 74% by weight, the fluidity during molding will be extremely deteriorated, which is not preferable.

Next, the thermosetting resin having at least one group selected from epoxy groups, carboxyl groups, hydroxyl groups, phenoxy groups, methylol groups, and amine groups in the present invention has a small radius of curvature (which was previously difficult to form when forming separation claws). For example, 0.01~Q, 05mm) The main purpose is to be able to obtain a smooth tip over a long period of time, and to improve the adhesion of the coating when coating with fluorinated polyether polymer. Specific examples of thermosetting resins include phenol resins and epoxy resins.

Here, the phenol resin is desirably one that does not cause thermal deterioration even when the polyphenylene sulfide resin is cross-wired and molded, and includes, for example, a phenol-alkyl resin or a phenol-formaldehyde resin. Here, the phenol-alkyl resin is a resin with the chemical structure shown by, and the commercially available product is Mirex (registered trademark)
Examples include L-225. Furthermore, the phenol-aldehyde resin is a condensate of phenols and aldehydes, or a condensate of phenols, nitrogen-containing compounds, and aldehydes. Here, the phenols include phenol, cresol xylenol, alkylphenol, resorcinol, etc., and the aldehydes include formalin, paraformaldehyde, trioxane, etc. Furthermore, as nitrogen-containing compounds, urea,
These are compounds having at least two active hydrogens such as aniline, melamine, and guanidine, and commercially available products such as Bell Pearl (registered trademark) manufactured by Kanebo Co., Ltd. can be exemplified. On the other hand, epoxy resin as a thermosetting resin is one that contains two or more epoxy groups and is liquid or solid at room temperature.Specific examples include bisphenol-based epoxy resin, alicyclic epoxy resin, and novolac-type epoxy resin. For example, as a novolak type epoxy resin, Araldai) E CN-1280 manufactured by Ciba Geigy Co., Ltd. can be exemplified. In particular, examples having hydroxyl groups include modified epoxy resins such as polyhydroxyphenylene ether, such as T-resin manufactured by Mitsui Petrochemicals. Furthermore, amines, acid anhydrides, polysulfides, phenolic resins, etc. may be used as curing agents for the epoxy resin, which are preferred in order to promote the effect of the three-dimensional network structure described below.

Such thermosetting resin is kneaded with polyphenylene sulfide resin at a high temperature of 280°C or higher, but the curing time is very short, so if the average particle size is large, it is difficult to obtain a composition that is uniformly dispersed in small units. Have difficulty. Therefore, the average particle size of the thermosetting resin is 50 μm and 80% by weight.
It is preferable that the particle size is 150 μm or less, and a small amount of less than 1% by weight is expected to have a thickening effect during melt flow at a low shear rate and reactivity with the fluorinated polyether polymer. 40 again
If the amount exceeds % by weight, the moldability or mechanical properties inherent to the polyphenylene sulfide resin will be impaired, which is not preferable.

In addition, in order to adjust the curing speed of the thermosetting resin, a small amount of a curing accelerator or retardant may be added, and each of the polyphenylene sulfide resin, glass fiber, and thermosetting resin Various fillers may be added within a range that does not deviate from the mixing ratio. Fillers include polyamideimide resin, polyetherimide resin,
Powders of heat-resistant polymer materials such as aromatic polyester resins, polyimide resins, silicone resins, and fluorine resins, potassium titanate voice cars, short fibers such as asbeth,
Metals or their oxides such as zinc, aluminum, magnesium, graphite, glass beads, silica balloons, shirasu balloons, inorganic powders such as silica, diatomaceous earth, mica, talc, and pigments such as carbon black, iron oxide, titanium oxide, Examples include heat stabilizers and the like.

The method of mixing the above raw materials is not particularly limited, but for example, various raw materials other than the thermosetting resin are mixed in advance, this is heated and melted using an extrusion kneader, and the mixture is placed near the exit of the cylinder. Either the thermosetting resin is supplied and extruded and kneaded, or the thermosetting resin is B-staged (prepolymerized) in a mixer such as a kneader, other raw materials are added thereto, mixed well, and then extruded. Although there are methods such as kneading with a kneader, the strands pressed in this way may be appropriately pelletized and molded into a desired shape with an injection molding machine or the like.

If a molded article of the above composition is coated with a fluorinated polyether polymer, excellent sliding properties will be added, and the coating will be able to maintain its sliding properties for a long period of time without peeling off. The fluorinated polyether polymer is preferably a polymer having the general formula % as the main structure, terminally bonded with at least one functional group, and having a number average molecular weight of approximately 1,000 to 5,000. is preferably an incyanate group. For example, a fluorinated polyether polymer as shown in
(registered trademark) Z-DISOC (average molecular weight 2000). There are no particular limitations on the method of coating with such a fluorinated polyether polymer, but spraying, dipping, etc. are simple and practical, but dipping is less effective in terms of the yield of the coating solution. This can be said to be the most preferable.

In addition, the fluorinated polyether polymer can be dissolved in a highly fluorinated organic solvent to prepare a solution with an appropriate concentration, but the concentration of such a polymer solution is usually 0.3 to 10.0% by weight, particularly 0.5-3.0% by weight when applying thin film coating
, is preferable. If the concentration of the liquid exceeds 10% by weight, the coating film will become thicker, resulting in an increase in free reactive end groups that do not participate in the reaction with the thermosetting resin in the composition.
Lubricity and non-stick properties may be poor. In addition, once the painting is completed, dry the paint film to remove the organic solvent (for example, if Freon is used as the solvent, use a hot air drying oven at about 50°C), and then thoroughly dry and apply the paint. It is desirable to perform a heat treatment at a high temperature (200° C. or higher) that also promotes the reaction between the functional groups of the polymer in the film and the thermosetting resin.

[Effect]

Glass fibers with a diameter of 6 μm or less are effective in increasing the rigidity and mechanical strength at high temperatures required for separation claws without impairing the radius of curvature and smoothness of the tip, and thermosetting resin It is not possible to obtain a smooth curve with the separating claws using conventional technology, and sometimes sharp edges (burrs) are formed, and even if a good radius of curvature is obtained during mold processing, it comes out of the resin during long-term use. The shape of the tip of the separating claw becomes poor due to the scars on the mold caused by corrosive gas or the filler compound, and the radius of curvature also becomes very small, making it easy for sharp edges to appear, resulting in a moderate curvature over a long period of time. This shows the effect of eliminating the drawback that a molded product with a radius could not be obtained. The reason for this is not clear, but due to the three-dimensional network structure formed by the functional groups of the thermosetting resin, the polyphenylene sulfide resin, and the improved reactivity or affinity of the curing agent, etc., This is presumed to be due to the thickening effect occurring at low shear speeds, such as when the material flows into the tip of the mold claw.

〔Example〕

The raw materials used in the Examples and Comparative Examples are shown below, and the abbreviations are shown in brackets. Note that all the blending ratios of these raw materials are expressed in weight %.

■Polyphenylene sulfide resin CPP5) (manufactured by Phillips Petroleum International, USA: Ryton P-4), ■Glass fiber [GF-3] (manufactured by Asahi Fiberglass Co., Ltd.: chopped strand, fiber diameter 3μ)
m.

fiber length 3 mm, aminosilane coupling treated product),
■Glass fiber CGF-6] (manufactured by the same company: chopped strand fiber diameter 6 μm 1 fiber diameter 3 mfns aminosilane coupling treated product), ■Glass fiber [GF-13') (manufactured by the same company: chopped strand, fiber diameter 13 μm, fiber (Length 3 mm, 7minosilane force spring treated product), ■Potassium titanate whisker [PKW] (manufactured by Otsuka Chemical Co., Ltd.; Teismo D101), ■Mica (manufactured by Canadian Mica Co., Ltd.: Mica S-325), ■
Phenolic resin [rPH-A:l (manufactured by Mitsui Toatsu Chemical Co., Ltd.:
Milex XL-225), ■Phenol resin CPH-B] (manufactured by Kanebo Co., Ltd.: Bell Pearl H-300), ■Epoxy resin CEP) (Coalaldite ECN-1280, manufactured by Ciba Geigy), [Phase] Curing agent (Showa Union Gosei Co., Ltd.) Conovolac type phenolic resin BRG-557), ■Fluorine-containing polymer [PFT] (Daikin Industries: Polyflon Tough Coat Enamel TC-74098K), @Fluorinated polyether polymer [PFEI (Montegison, Italy: Fonbrin) Z-DI 5OC200
0), Examples 1 to 9: After dry-mixing the raw materials other than the thermosetting resin in advance at the blending ratios shown in Table 1, the mixture was put into a twin-screw melt extruder (manufactured by Yuboshi Tekko Co., Ltd.: PCM-30). Supply and cylinder temperature 290
℃, screw rotation speed 5 Orpm, the thermosetting resin is fed into the molten first cylinder from the middle of the extruder, kneaded and extruded, and granulated, and then the pellets are heated to the cylinder temperature. 315℃, injection pressure 8
00 kg/am, injection molded under the conditions of mold temperature 130°C, inner diameter 14 mm, outer diameter 23 m, length 13 m.
m cylinder, width 12.7 mm, length 126 mm, thickness 3
．． 2 mm plate material, width 4 mm, length 25 mm, thickness 1
mm plate material and Canon Co., Ltd. copy machine NP2O15
A test piece with the same shape as the separation claw used in the mold was obtained.

Among these test pieces, separation claw test pieces are used to investigate practical functionality such as change in contact angle before and after paper passing, quality of separation, presence or absence of claw marks, amount of toner adhesion, etc., and test pieces for lubricity evaluation are as follows: In all cases except Example 4, the fluorinated polyether polymer Fomblin ■ was immersed in a Freon 113 solution with a concentration of 2.0% by weight, and then taken out from the condensate at about 200°C.
The baking process was carried out for 2 hours with Polyfron Tough Coat Enamel T (-74098K [
After spray-coating the film, it was baked at 180° C. for about 1 hour.

Impact strength, bending strength, rigidity at high temperatures (retention rate of elastic modulus), radius of curvature of the tip, non-adhesiveness, persistence of non-adhesive components, practical functionality, and lubricity for the above test pieces. In addition, the surface smoothness of Examples 1 to 3 and 6 was also evaluated, and the evaluation methods were as follows.

(1) Impact strength: Notched Izo impact strength based on ASTM-D256.

(2) Bending strength; Based on ASTM-D790.

(3) Stiffness at high temperatures (retention rate of elastic modulus): Using a dynamic viscoelasticity measuring device manufactured by Toyo Seiki Seisakusho, we measured the frequency using a test piece with a width of 4 mm, a length of 25 mm, and a thickness of 1 mm. Tensile stress was applied at 10 Hz, and changes in tensile modulus with respect to temperature changes were determined at 25°C and 260°C.

(4) Radius of curvature at the tip: Using a projector V-16D manufactured by Nippon Kogaku Co., Ltd., the radius of curvature is shown as the minimum and maximum range of the measured value at n=10.

(5) Non-adhesiveness: Evaluation was performed by determining the contact angle between water and styrene monomer using a goniometer type contact angle measuring device manufactured by Elma Optical Co., Ltd.

(6) Practical functionality: Using a Canon dry copying machine model NP2O15, a test piece with the same shape as the separating claw used in the machine was attached, and 100,000 sheets of A4 size copy paper were continuously passed through. , the number of copies made after repeated copying, the number of copies made at the time of paper separation failure (paper jam), presence or absence of toner image contamination due to nail marks, amount of separation/toner adhesion to the nails, i.e., no amount of adhesion at all. or a small amount (◎ mark), a relatively small amount (O mark),
Each was investigated using four evaluation criteria: comparatively large amounts (△) and large amounts (x).

(7) Persistence of non-adhesive components: After the paper passing test, the toner adhering to the separating nail was wiped off with ethyl alcohol, and the contact angle with respect to water and styrene monomer was measured using a goniometer-type contact angle measuring device manufactured by Elma Optical Co., Ltd. It was measured using

(8) Lubricity: Using a test piece with an inner diameter of 14 mm, an outer diameter of 23 mm, and a length of 13 mm, a load of 1 kg/c was applied using a thrust type friction tester.
Bearing steel (SUJ2) was used as a mating material under the conditions of 1 cm/sec and a speed of 1 cm/sec.

The results obtained from the above tests are summarized in Table 2.

Comparative Examples 1 to 4: The raw materials were mixed in the proportions shown in Table 3, and the same operations as in Example 1 were performed except for Table 3 to produce cylindrical and plate-shaped molded bodies and separation claws. The same properties were investigated as in Examples 1-9.

The results obtained are summarized in Table 4.

Table 4 The following is clear from Tables 2 and 4. That is, Examples 1 to 9 have good impact strength and bending strength, and also have good tensile modulus at high temperature (rigidity at high temperature), accuracy of tip curvature radius, and surface smoothness (measured only in Examples 1 to 3.6). Showing good value. On the other hand, Comparative Example 1, which uses glass fibers with a diameter of 6 μm but does not use a thermosetting resin, shows good values such as impact strength, bending strength, and tensile modulus similar to those of the examples. However, the radius of curvature of the tip became too small, resulting in so-called cracks, which was undesirable. In addition, in Comparative Example 2, the fiber length of the potassium titanate whiskers used as a reinforcing agent was too short to exhibit a reinforcing effect, and even though the radius of curvature at the tip was appropriate, both mechanical strength and tensile modulus at high temperatures were poor. Furthermore, Comparative Example 3, which used thick glass fibers with a fiber diameter of 13 μm, had poor surface smoothness and a very large radius of curvature at the tip, and this tendency was also noticeable in Comparative Example 4, which used glass fibers with large diameters. there were.

Next, in terms of non-adhesiveness and durability of the non-adhesive component, Example 4 and Comparative Example 1, that is, those that do not use a fluorinated polyether polymer as a coating material and those that do not use a thermosetting resin, are good. I couldn't get a good value, but
Other Examples 1 to 3.5 to 9 and Comparative Examples 2 to 4 all showed good results.

Furthermore, regarding practical functionality, in Examples 1 to 9, 100,000 copies were completed without any separation failure, but in Comparative Examples 1 to 4, paper jams occurred midway through, and there were no claw marks. Regarding the toner adhesion amount, all of the samples coated with a fluorinated polyether resin using a thermosetting resin (other than Example 4 and Comparative Example 1) showed favorable results.

〔effect〕

As described above, the separating claw for copying machines made of polyphenylene sulfide resin, glass fiber with a fiber diameter of 6 μm or less, and thermosetting resin of the present invention has excellent mechanical strength and rigidity at high temperatures, and has excellent curvature at the tip of the separating claw. A radius that is too small or too large will not cause paper jams or incorrect separation direction (and the surface is smooth, so the separating paper will not get caught). As a result, it is possible to achieve excellent non-adhesive properties with a good separation claw shape and strong adhesion strength to the base material, and as a result, it can withstand long-term continuous use. It can be said that the significance of the invention is extremely large.

Patent applicant: Western Bear Rulon Industrial Co., Ltd. Agent: Kama 1) Written by −

Claims (1)

[Claims] 1. Polyphenylene sulfide resin 25-80% by weight
and 19 to 74% by weight of glass fibers with a fiber diameter of 6 μm or less,
Furthermore, it is a molded article of a resin composition comprising 1 to 40% by weight of a thermosetting resin having at least one group among an epoxy group, a carboxyl group, a hydroxyl group, a phenoxy group, a methylol group, and an amino group. Separation claw for copy machine. 2. At least the tip friction portion has the general formula -C_xF_2_x-O- [where x is an integer from 1 to 4]
2. A separating claw for a copying machine according to claim 1, wherein the separation claw for a copying machine is coated with a fluorinated polyether polymer having as a main structural unit and having at least one functional group bonded to the end thereof.