JP2561919B2 - Separation claw for copier - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a separating claw for a copying machine.

[Conventional technology]

Conventionally, copying machines are roughly classified into two types, dry type and wet type. In the dry type copying machine, the electrostatic latent image formed on the surface of the photosensitive drum corresponding to characters and figures is converted into a toner image. After that, the toner image is transferred onto the paper surface supplied from the paper feed cassette, and the surface is heated and pressed by a heated fixing roller to fix the transferred toner image onto the paper surface. A mechanism is incorporated to fuse the fibers and prevent them from separating easily. In order to reliably discharge the copy paper that has passed through the fixing roller without wrapping around the roller, a method is employed in which a separating claw is used and the end of the copy paper is scooped while the tip of the copy claw is in close contact with the outer peripheral surface of the roller. Therefore, in such a separating claw, the frictional resistance against the outer peripheral surface of the roller is small and the surface is not damaged, it has sufficient mechanical strength, especially high temperature rigidity, and the tip shape has sufficient accuracy. It is required to have properties such as being obtained and not sticking the toner.

In order to satisfy the essential properties for such a separating nail, a heat-resistant resin such as polyimide, polyamide-imide, polyphenylene sulfide, polyether ether ketone, polysulfone, polyether imide, aromatic polyamide, aromatic polyester, It has been proposed to use glass fiber, potassium titanate fiber, heat resistant fiber such as carbon fiber, and a composition containing fluorine resin as a material. For example, in resins such as polyphenylene sulfide, polyether sulfone, and polyamide, the average fiber length is 5 to 30.
A composition to which a short fiber reinforcing agent having an average fiber diameter of 0.2 to 0.5 .mu.m (potassium titanate whiskers, etc.) is added (Japanese Patent Laid-Open No. Sho 60-96)
61-182071), a composition in which a heat-resistant fiber such as potassium titanate fiber or asbestos fiber or an inorganic filler such as mica or talc is added to a thermoplastic polyether aromatic ketone such as polyether ether ketone resin ( JP-A-61-27575), and a composition containing a tetrafluoroethylene resin and optionally glass in a hard heat-resistant resin such as polyimide, polyamide-imide and phenol (JP-A-56-132368). ), A polyetherketone, potassium titanate fibers and a fluorine resin (Patent Document 1)
No. 60-257467), a composition comprising a polyetherketone, carbon fiber and a fluorine resin (Japanese Patent Laid-Open No. 61-55674) and the like are disclosed. However, JP-A-61-1
Separation claws using short fibers such as potassium titanate fibers as described in 182071, No. 27575 and No. 257467 as reinforcing agents are inferior in mechanical strength such as bending strength and impact strength, and have high temperature. Since the rigidity of the fixing paper is sometimes inferior, the tip of the separating claw may be chipped or bent due to the resistance of the fixing paper passing therethrough, so that the separating function cannot be fulfilled. Further, JP-A-56-132368 and JP-A-61-182071. As described in No. 6, glass powder or glass beads cause the same problem as in the case of the above short fiber reinforcing agent, and glass fiber or carbon fiber has a large surface roughness when a separating claw is formed and a large radius of curvature at the tip. In many cases, it exceeds 0.1 mm, so that a good tip shape cannot be obtained, the fixing paper cannot be smoothly picked up, and a phenomenon of separation direction failure occurs. Further, even when a solid lubricant such as a fluorine resin is mixed in, such as JP-A-56-132368, JP-A-60-257467 and JP-A-61-55674, both the lubricity and the non-adhesiveness are insufficient. The problem of paper clogging or nail mark is likely to occur depending on long-term continuous use or the type of toner.

[Problems to be solved by the invention]

As described above, in the conventional technique, it is possible to easily obtain heat resistance that does not cause deterioration of rigidity at high temperature, excellent mechanical strength such as impact strength or bending strength of the nail tip, and preferable radius of curvature of the nail tip. Not to mention the moldability and the smoothness of the surface of the molded product, there was the problem that a separating claw excellent in lubricity, non-adhesiveness to toner, and durability of this non-adhesiveness was not obtained. .

[Means for solving problems]

In order to solve the above problems, the present invention provides a polyphenylene sulfide resin 25 to 80% by weight, a glass fiber having a fiber size of 6 μm or less 19 to 74% by weight, an epoxy group, a carboxyl group, a hydroxyl group and a phenoxy group. , A resin composition comprising 1 to 40% by weight of a thermosetting resin having at least one of a methylol group and an amino group is used as a separating claw for a copying machine. The details are described below.

First, the polyphenylene sulphide resin of the present invention is used as a matrix resin, and exhibits excellent heat resistance with a heat distortion temperature of 260 ° C. or higher, and a melt viscosity of other resin called engineering plastics. It is a preferable resin because it is low in comparison and excellent in moldability and filling properties of fillers. The reason for setting the amount of this resin to be 25-80% by weight is that if it is less than 25% by weight, the moldability is extremely poor, and if it exceeds 80% by weight, the amount of the reinforcing agent becomes small and practical strength cannot be obtained. It is not possible to use it for As a general-purpose molding material, a polyphenylene sulfide resin containing 40% by weight or 60% by weight of glass fiber having an average fiber diameter of 13 μm is commercially available. The surface roughness of these molded products is 5-10 μm ( _Rmax ) has a roughness, and the radius of curvature of the tip of the separating claw needs to have an accuracy of 0.1 mm or less, preferably 0.05 mm or less, but it is difficult to obtain such accuracy with the glass fiber as described above. Therefore, it is important that the diameter of the glass fiber to be blended is 6 μm or less, and if such a fiber is used, the surface roughness of the molded product is 1 to 3 μm.
m or less, and the radius of curvature of the separating claw is 0.
With a thickness of less than 05 mm, a molded product with a tip shape and smoothness that fully expresses the function as a separating claw can be obtained. In addition,
Considering the rigidity and mechanical strength of the separating claw at high temperature, the glass fiber length is 0.1 mm or more, preferably 0.5 mm or more,
It is necessary that the content be 19% by weight or more. However, if the amount exceeds 74% by weight, the fluidity at the time of molding is extremely deteriorated, which is not preferable.

Next, the thermosetting resin having at least one group of the epoxy group, the carboxyl group, the hydroxyl group, the phenoxy group, the methylol group, and the amino group in the present invention has a small radius of curvature which was conventionally difficult at the time of molding a separate nail ( (0.01-0.05 mm) for the long term to obtain a smooth tip, and to improve the adhesive strength of the coating when coating a fluorinated polyether polymer Specific examples of the thermosetting resin include a phenol resin and an epoxy resin.

Here, it is a matter of course that the phenol resin is preferably one that does not cause thermal deterioration during kneading and molding of the polyphenylene sulfide resin, and examples thereof include a phenol alkyl resin or a phenol formaldehyde resin. is there. Here, the phenol alkyl resin is As a resin having a chemical structure represented by, examples of commercially available products include Mirex (registered trademark) XL-225 manufactured by Mitsui Toatsu Chemicals, Inc. Further, a phenol / aldehyde resin is a condensate of phenols and aldehydes,
Alternatively, it is a condensate of a phenol, a nitrogen-containing compound and an aldehyde. Here, the phenols include phenol, cresol xylenol, alkylphenol, resorcinol and the like, and the aldehydes include formalin, paraformaldehyde, trioxane and the like. Further, the nitrogen-containing compound is, for example, a compound having at least two active hydrogens such as urea, aniline, melamine, and guanidine, and a commercially available product such as Kanebo Belpearl (registered trademark) can be exemplified. On the other hand, an epoxy resin as a thermosetting resin is a liquid or solid one containing two or more epoxy groups at room temperature, and specific examples thereof include a bisphenol epoxy resin, an alicyclic epoxy resin, and a novolak epoxy. Examples of the resin include a novolak type epoxy resin such as Araldite ECN-1280 manufactured by Ciba-Geigy. In particular, examples of those having a hydroxyl group include modified epoxy resins made of polyhydroxyphenylene ether, such as T-resin manufactured by Mitsui Petrochemical. Further, amines, acid anhydrides, polysulfides, phenol resins and the like may be used as a curing agent for the epoxy resin,
It is preferable for promoting the effect of the three-dimensional network structure described later.

Such a thermosetting resin is kneaded with a polyphenylene sulfide resin at a high temperature of 280 ° C. or higher, but since the curing time is very short, a composition in which the average particle size is large and the particles are uniformly dispersed in small units is used. Hard to get. Therefore, it is preferable that the average particle size of the thermosetting resin is 50 μm and 80% by weight or more is a particle size of 150 μm or less, and if the compounding amount is less than 1% by weight, the melt flow at a low shear rate The thickening effect and the reactivity with the fluorinated polyether polymer cannot be expected, and if the amount exceeds 40% by weight, the original moldability or mechanical properties of the polyphenylene sulfide resin will be impaired. Not preferable.

Incidentally, in order to adjust the curing speed of the thermosetting resin, a small amount of a curing accelerator or a retarder may be added, and further, each of the polyphenylene sulfide resin, the glass fiber and the thermosetting resin is the above-mentioned. You may mix | blend various fillers within the range which does not deviate from the limited mixing ratio. As a filler, polyamideimide resin, polyetherimide resin, aromatic polyester resin, polyimide resin, silicone resin, powder of heat-resistant polymer material such as fluorine resin, potassium titanate whiskers, short fibers such as asbestos,
Metals such as zinc, aluminum and magnesium or oxides thereof, graphite, glass beads, silica balloons, silas balloons, inorganic powders such as silica, diatomaceous earth, mica and talc, and pigments such as carbon black, iron oxide and titanium oxide. , Heat stabilizers, and the like.

The method of mixing the above respective raw materials is not particularly limited, but for example, various raw materials other than the thermosetting resin are mixed in advance, and this is heated and melted by using an extrusion kneader, and near the cylinder outlet. A thermosetting resin is supplied and extruded and kneaded, or the thermosetting resin is B-staged (prepolymerized) in a mixer such as a kneader, and other raw materials are added to this and well mixed, and extruded. There is also a method of kneading with a kneader, but the extruded strands may be appropriately pelletized, and the pellets may be molded into a desired shape with an injection molding machine or the like.

When a molded article of the above composition is coated with a fluorinated polyether polymer, excellent sliding properties are added, and the coating can be retained for a long period of time without being peeled off. Here, the fluorinated polyether polymer has a general structure —C _X F _2X —O— [x is an integer of 1 to 4] as a main structure, is end-bonded with at least one functional group, and has a number average molecular weight of about 1000. It is preferable that the polymer is ˜5000, and the functional group is preferably an isocyanate group. For _{example, OCN-C 6 H 3 (} CH 3) -HNCOF 2 C 2 F 4 O m CF 2 O n CF 2 CONH- (CH 3) fluorophosphate fluorinated polyether as indicated by C ₆ H ₃ -NCO heavy As a commercial product, a commercially available product such as Fomblin (registered trademark) Z-DISOC (average molecular weight 2000) manufactured by Italy Montedison Co., Ltd. can be exemplified. The method for coating such a fluorinated polyether polymer is not particularly limited, but the spraying method, the dipping method and the like are simple and practical, but the dipping method is preferable in terms of the yield of the coating liquid. Can be said to be the most preferable. Further, the fluorinated polyether polymer can be dissolved in a highly fluorinated organic solvent to prepare a solution having an appropriate concentration, but the solution concentration of such a polymer is usually 0.3 to 10.0% by weight, and particularly thin film coating is performed. At this time, 0.5 to 3.0% by weight is preferable. When the concentration of the liquid exceeds 10% by weight, the coating film becomes thick, and as a result, the number of free reactive end groups that do not participate in the reaction with the thermosetting resin in the composition is increased, resulting in lubricity and non-adhesion. There is a risk that it will be inferior. When the coating is completed, dry to remove the organic solvent in the coating (for example, when Freon is used as a solvent, use a hot air drying oven at about 50 ° C). It is desirable to perform a heat treatment at a high temperature (200 ° C. or higher) that also accelerates the reaction between the functional group of the polymer in the film and the thermosetting resin.

[Action]

The glass fiber having a diameter of 6 μm or less is effective in enhancing the rigidity and mechanical strength required for the separating claw at a high temperature without inhibiting the radius of curvature and the smoothness of the tip portion, and is a thermosetting resin. Does not produce a smooth curve with the conventional separating claw, sometimes results in a sharp edge (burr), and even if a good radius of curvature is obtained during mold processing, it comes out of the resin in the process of long-term use. Due to the corrosive gas or the compounded filler, the tip shape of the separating claw deteriorates due to the scratches on the mold, and the radius of curvature is also very small, so that sharp edges tend to appear and it has spread over a long period of time. It exhibits an action of eliminating the drawback that a molded product having an appropriate radius of curvature could not be obtained. The reason for this is not clear, but because of the three-dimensional network structure formed by the functional group of the thermosetting resin and the polyphenylene sulfide resin and further improved reactivity or affinity of the curing agent, It is presumed that the thickening effect occurs even at the time of melt flow, particularly at a low shear rate such that it flows into the tip of the nail of the mold.

〔Example〕

The raw materials used in Examples and Comparative Examples are collectively shown below, and the abbreviations are shown in []. The blending ratios of these raw materials are all expressed in% by weight.

Polyphenylene sulphide resin [PPS] (made by US Petroleum Internals Company:
Ryton P-4], glass fiber [GF-3] (manufactured by Asahi Fiber Glass Co., Ltd .: Chopped strand, fiber diameter 3 μm, fiber length 3 mm, aminosilane coupling treated product), glass fiber [GF-6] (manufactured by the same company) : Chip strand, fiber diameter 6 μm, fiber length 3 mm, aminosilane coupling treated product, glass fiber [GF-13] (manufactured by the company: Chip strand, fiber diameter 13 μm, fiber length 3 mm, aminosilane coupling treated product) ), Potassium titanate whiskers [PKW] (Otsuka Chemical Co., Ltd .: Teismo D101), mica (Canada Mica Co., Ltd .: Mica S-325), phenol resin [PH-A] (Mitsui Toatsu Chemical Co., Ltd .: Millex XL-) 225), phenol resin [PH-B] (Bellpearl H, manufactured by Kanebo)
-300), epoxy resin [EP] (Ciba-Geigy: Araldite ECN-1280), curing agent (Showa Union Gosei: Novorask type phenol resin BRG-557), fluorine-containing polymer [PFT] (Daikin Industries, Ltd.) Made by: Polyflon tough coat enamel TC-7409BK), fluorinated polyether polymer [PFE] (made by Ikoku Montedison Co., Ltd .: Phomblin Z-DISOC2000), Examples 1 to 9: at the mixing ratios shown in Table 1. After dry-mixing the raw materials other than the thermosetting resin in advance, the mixture is supplied to a twin-screw melt extruder (PCM-30 manufactured by Ikegu Iron Works Co., Ltd.) under the conditions of a cylinder temperature of 290 ° C. and a screw rotation speed of 50 rpm. Siri that is in a molten state from the middle The thermosetting resin is fed into the mould, and the mixture is kneaded and extruded to granulate, and then the pellet is heated to a cylinder temperature of 315 ° C and an injection pressure of 800 kg.
Injection molding under conditions of / cm ² and mold temperature 130 ° C, inner diameter 1
4 mm, outer diameter 23 mm, length 13 mm cylinder, width 12.7 mm, length 126 m
m, a plate having a thickness of 3.2 mm, a plate having a width of 4 mm, a length of 25 mm, and a thickness of 1 mm, and a test piece having the same shape as the separating claw used in the Canon NP2015 copying machine were obtained. Of these test pieces, the separation nail test piece and the lubricity evaluation test piece for practical functional investigations such as the change in contact angle before and after passing the paper, good or bad separation, presence or absence of nail marks, and toner adhesion amount With the exception of Example 4, all were immersed in a Freon 113 solution in which the fluorinated polyether polymer phoombrin was dissolved in a concentration of 2.0% by weight, taken out from the solution, and baked at about 200 ° C. for 2 hours. Was spray-coated with Polyflon Tough Coat Enamel TC-7409BK and then baked at 180 ° C. for about 1 hour.

Impact strength, bending strength, rigidity at high temperature (retention rate of elastic modulus), radius of curvature of tip, non-adhesiveness,
The durability, practical functionality and lubricity of the non-adhesive component and the surface smoothness of Examples 1 to 3 and 6 were also evaluated. The evaluation methods are as follows.

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

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

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

(4) Radius of curvature at the tip: A projector V-16D manufactured by Nippon Kogaku Co., Ltd. was used, and the minimum and maximum measured values at n = 10 are shown.

(5) Non-adhesiveness: Using a goniometer-type contact angle measuring instrument manufactured by Elma Optical Co., Ltd., the contact angle with respect to water and a styrene monomer was obtained and evaluated.

(6) Practical functionality: Using a Canon dry copy machine NP2015 type, attach a test piece of the same shape as the separation claw used in it, and attach it to A4
100,000 sheets of standard copy paper are passed continuously, and copying is repeated. The number of copies at the time of paper separation failure (paper jam), presence or absence of toner image contamination due to nail marks, toner on separation nails The amount of the adhered amount, that is, there is no or a very small amount (◎ mark), a relatively small amount (○ mark), a relatively large amount (△ mark) and a large amount (× mark). Each was examined, such as using the stage as an evaluation criterion.

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

(8) Lubrication: Using a test piece with an inner diameter of 14 mm, an outer diameter of 23 mm, and a length of 13 mm, use a thrust type friction tester to load bearing steel (SUJ2) under a load of 1 kg / cm ² and a speed of 1 cm / sec. I asked for it as a partner material.

 The results obtained in 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 below. Except for the above, the same operations as in Example 1 were performed to produce cylindrical and plate-shaped molded bodies and separating claws, and the same various properties as those performed in Examples 1 to 9 were examined. The results obtained are summarized in 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 tensile elastic modulus at high temperature (rigidity at high temperature), accuracy of tip curvature radius and surface smoothness (measured only in Examples 1 to 3). It shows a good value. On the other hand, Comparative Example 1 in which a glass fiber having a diameter of 6 μm is not used in combination with a thermosetting resin shows good values such as impact strength, bending strength, and tensile elastic modulus, which are similar to those of the Examples. However, the radius of curvature of the tip becomes too small to cause so-called burr, which is not preferable. Further, in Comparative Example 2, the fiber length of potassium titanate whiskers as a reinforcing agent was too short to exert the reinforcing effect, and although the tip radius of curvature was proper, both the mechanical strength and the tensile elastic modulus at high temperature were poor. Further, Comparative Example 3 using a thick glass fiber having a fiber diameter of 13 μm has a poor surface smoothness and a very large radius of curvature of the tip, and such a tendency is remarkable in Comparative Example 4 using a glass fiber having a large diameter. Atsuta

Next, regarding the non-adhesiveness and the durability of the non-adhesive component, Example 4 and Comparative Example 1, that is, those not using the fluorinated polyether polymer as a coating agent and those not using the thermosetting resin were used. Good values were not obtained, but other Examples 1 to 3, 5 to 9 and Comparative Example 2
All 4 showed good results.

Regarding practical functionality, Examples 1 to 9 completed copying of 100,000 sheets without causing separation failure, but Comparative Examples 1 to 4 caused paper jam in the middle and presence of nail marks. Also, regarding the toner adhesion amount, those in which a thermosetting resin was used in combination and which was coated with a fluorinated polyether resin (other than Example 4 and Comparative Example 1) showed favorable results.

〔effect〕

As described above, the separating claw for a copying machine, which is composed of the polyphenylene sulfide resin of the present invention, the glass fiber having a fiber diameter of 6 μm or less, and the thermosetting resin, has excellent mechanical strength and rigidity at high temperature. There is no paper jam or improper separation direction due to too small or too large radius of curvature of the nail tip, and the smooth surface does not catch the separation paper. By applying the thin film of as a coating, it is possible to realize excellent non-adhesiveness with a good separation nail shape as it is under strong adhesion strength with the base material, so that it can withstand long-term continuous use sufficiently. Is. Therefore, it can be said that the significance of the present invention is extremely great.

Claims (2)

(57) [Claims] 1. A polyphenylene sulfide resin 25 to 80% by weight, and a glass fiber having a fiber diameter of 6 μm or less 19 to 74% by weight,
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 of an epoxy group, a carboxy group, a hydroxyl group, a phenoxy group, a methylol group and an amino group. Separation claw for copiers. 2. At least the tip friction portion has a general structural formula —C _X F _2X —O— [where x is an integer of 1 to 4] as a main structural unit, and at least one functional group is bonded to the end. The separating claw for a copying machine according to claim 1, which is coated with a fluorinated polyether polymer.