JPH10254199A - Sliding guide to transfer sheet in image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sliding guide which can respond to requirements such as fast treating speed and compact size of the main body of an image forming device and which has excellent heat resistance, flame retardant property, wear resistance and resistance against deposition of a toner. SOLUTION: This sliding guide is formed in such a manner that the guide slides on and touches a sheet carried after an image is formed so as to guide the sheet. The sliding guide is composed of a resin compsn. essentially comprising a fluorocarbon resin such as tetrafluoroethylene, tetrafluoroethylene- perfluoroalkylvinylether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and tetrafluoroethylene-ethylene copolymer, and preferably with addition of a fiber reinforcing material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliding guide for conveying a sheet of an image forming apparatus for guiding a sheet formed and conveyed in an image forming apparatus such as a copying machine, a facsimile and a laser beam printer.

[0002]

2. Description of the Related Art An image forming apparatus using an electrophotographic process, such as an electrophotographic copying machine or a laser printer, transfers an image formed on a photoreceptor by an electrophotographic process as a toner image onto transfer paper, and transfers the image. After fixing on paper by a fixing device, the sheet is discharged out of the apparatus.

The fixing device includes a fixing roller having a built-in heater and a pressure roller pressed against the fixing roller. A transfer paper carrying a fixed toner image is passed through a nip portion of the fixing roller, and the toner is heated and pressed to apply the toner. The sheet is melted and fixed on the transfer sheet, and then the transfer sheet is discharged out of the apparatus by a discharge roller, a discharge roller and the like.

FIG. 1 shows a schematic configuration example of a fixing device having a heating roller. The fixing device A includes a fixing roller 2 having a heater 1 built therein and a pressure roller 3 that is driven to rotate with a transfer paper path interposed therebetween. Unfixed toner image 1 transported by transport belt 4 from a transfer unit (not shown)
A sheet 5 such as a transfer paper carrying the sheet 4 is guided by a fixing entrance guide 6 and inserted into a nip portion between the fixing roller 2 and the pressure roller 3. The image is fixed and sent out. The sheet 5 after fixing is
The fixing roller 2 is separated from the fixing roller 2 by the tip of the separation claw 7 that contacts the lower side of the nip portion.

[0005] The sheet peeled off from the fixing roller is slid and guided by paper ejection guides 10 and 11 and passes through a conveyance path.
The paper passes between the paper discharge roller 9 that is driven to rotate and the paper discharge roller 8 that is driven to rotate, and is further guided by paper discharge guides 12 and 13 and discharged outside the apparatus.

[0006] In such a sliding guide for sheet conveyance,
Since heat resistance and flame retardancy are required as well as the paper discharge roller, and sliding characteristics that allow the sheet to pass smoothly are also required,
Materials such as polyphenylene sulfide (PPS) and polyacetal (POM) have been used.

By the way, a copying machine, a facsimile (Fa)
x), in an image forming apparatus such as a laser beam printer (LBP), there is an increasing demand for a reduction in processing time, and therefore, the printing function is speeded up and the fixing temperature is raised (250 ° C.).
Nearby). For example, the normal use atmosphere temperature around the fixing area of the device thus accelerated is 25 to 150 ° C., and 50 to 250 ° C. instantaneously.
° C may be reached.

Further, since the downsizing of the main body of the image forming apparatus is also an important technical problem, the distance between the high-temperature fixing portion and the sliding guide for sheet conveyance tends to be short.

[0009]

However, in order to satisfy the above-mentioned demands for shortening the processing time and miniaturizing the apparatus,
The sheet conveyance sliding contact guide has a new problem that has not occurred in the conventional image forming apparatus, such as contamination by toner, deformation due to heat, ensuring safety, and wear of the sliding contact surface.

The dirt on the sliding guide caused by the toner often directly affects the deterioration of the image state, such as dirt and unclearness of the image.

Therefore, an object of the present invention is to solve the above-mentioned problems and to provide heat resistance, flame retardancy, and the like so as to meet the technical demands of increasing the processing speed of the image forming apparatus and miniaturizing the apparatus body. An object of the present invention is to provide a sliding contact guide for sheet conveyance of an image forming apparatus having excellent abrasion resistance and non-adhesion of toner.

[0012]

In order to solve the above-mentioned problems, according to the present invention, in a sliding contact guide for slidingly contacting a sheet conveyed in the apparatus after image formation and guiding the sheet, the sliding contact guide is used. It was formed of a resin composition containing a fluorocarbon resin as a main component.

Alternatively, the resin composition containing the fluorocarbon resin as a main component is a resin composition containing a fluorocarbon resin as a main component and a fibrous reinforcing material added thereto, and is used as a sliding guide for sheet conveyance in an image forming apparatus. It is.

Alternatively, the sliding contact guide for conveying the sheet of the image forming apparatus is manufactured by injection molding using a fluorocarbon resin.

If the sheet conveying sliding guide of the image forming apparatus is formed of a fluorocarbon resin, the image forming apparatus can obtain a clear image to which no toner adheres. The sheet conveying sliding guide has heat resistance, It also has flame retardancy.

A sliding guide for sheet conveyance made of a resin composition in which a fibrous reinforcing material is added to a fluorocarbon resin has excellent wear resistance and small thermal deformation, so that an image with a higher processing speed can be obtained. It becomes a sliding contact guide for sheet conveyance that can also be used in the forming apparatus.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A sliding guide for sheet conveyance was formed of a fluorocarbon resin as follows. As the fluorocarbon resin, a molten fluorocarbon resin is preferable in terms of moldability, and a fluorocarbon resin that can be injection-molded is more preferable. Among them, PFA, F
EP and ETFE are particularly preferred.

As a typical example of the fluorocarbon resin,
Examples of the resin include those listed below. In addition, []
Inside, the heat distortion temperature (under bending stress of 4.6 kgf / cm ² , JIS K 7207), melting point, thermal decomposition temperature, melt viscosity, number average molecular weight, hardness (ASTM)
D2240, JIS K 7215), limiting oxygen index (ASTM D2863), and UL94 flammability standard are shown in this order, and all numerical values are representative values.

(1) Polytetrafluoroethylene (PT)
FE), [121 ° C, 327 ° C, about 508-53
8 ° C, 10 ¹¹ to 10 ¹² poise (340 to 380 ° C),
About 10 ⁶ to 10 ⁷ , D50 to D65, 95% by volume
(Equivalent to V-0) (2) Tetrafluoroethylene-perfluoroalkylvinyl ether copolymer (PFA), [74 ° C., 3
100 to 310 ° C, 464 ° C or higher, 10 ⁴ to 10 ⁵ poise <380 ° C.>, (2 to 3) × 10 ⁵ , D60 to
D64, 95% by volume or more, equivalent to V-0] (3) Tetrafluoroethylene-hexafluoropropylene copolymer (FEP), [72 ° C, 250 to 28
2 ° C., 419 ° C. or higher, 4 × 10 ⁴ to 10 ⁵ poise (380 ° C.), (3 to 5) × 10 ⁵ , D60 to D6
5, 95% by volume or more, equivalent to V-0] (4) Tetrafluoroethylene-ethylene copolymer (E
TFE), [89-104 ° C, 260-270 ° C,
347 ° C or higher, 10 ⁴ to 10 ⁵ poise <300
° C>, 1 × 10 ⁵ , D75, 30% by volume, V−
0) (5) Polychlorotrifluoroethylene (PCTF
E), [126 ° C, 210-212 ° C, 347-
418 ° C., 10 ⁷ poises <230 ℃>, (1~5)
× 10 ⁵ , D90, 95% by volume or more, equivalent to V-0] (6) Chlorotrifluoroethylene-ethylene copolymer (ECTFE), [116 ° C, 245 ° C, 330
° C or higher, 2 × 10 ³ to 10 ⁵ poise <260 to 315
° C>, (1-5) × 10 ⁵ , D55-D75, 6
0 volume%, equivalent to V-0] (7) Polyvinylidene fluoride (PVDF), [
149 ° C, 156-170 ° C, 400-475 ° C,
2 × 10 ³ to 10 ⁵ poise (210 to 270 ° C.),
(3-8) × 10 ⁵ , D70-D80, 44% by volume, equivalent to V-0] (8) Polyvinyl fluoride (PVF), [195
~ 205 ° C, 372-480 ° C, (2-5) x 10
⁵ , 23% by volume, equivalent to V-0] (9) Tetrafluoroethylene-hexafluoropropylene-perfluoroalkylvinyl ether copolymer (EPE) [440 ° C. or higher].

The fluorocarbon resin is not only a homopolymer, but also a copolymer of two or more of the above-mentioned monomers of the fluorocarbon resin in a polymerization amount of, for example, about 1:10 to 10: 1, or a terpolymer. It may be a fluorinated polyolefin such as coalesced or the like, or may be a mixture of two or more kinds, all of which exhibit properties as a solid lubricant. Among these, PTFE
Is particularly preferable because it has excellent properties such as heat resistance, chemical resistance, non-adhesion, and low friction coefficient.

These fluorocarbon-based resins are preferred because they have a relatively high differential pyrolysis onset temperature. For example, P
The decomposition points of TFE and PVDF are about 490 ° C. and about 350 ° C., respectively, and their differential thermal decomposition onset temperatures also show about 555 ° C. and about 460 ° C., respectively.

Further, among the fluorocarbon resins, there is a tetrafluoroethylene fluorocarbon resin, and the following can be exemplified in addition to the above-mentioned PTFE.

Tetrafluoroethylene-perfluoro [alkyl (methyl, ethyl, propyl, butyl)] vinyl ether copolymer (PFA) tetrafluoroethylene-hexafluoropropylene copolymer (FEP) tetrafluoroethylene-hexafluoro Propylene-perfluoro [olefin (alkyl, propyl)]
Vinyl ether terpolymer (EPE)-Ethylene-tetrafluoroethylene [alternate] copolymer (ETFE) (ETFE may contain the third component. The alternating property is 90 to 100%. Are preferred because of their stable physical properties.)

Since the tetrafluoroethylene-based fluorocarbon resin has (--CF ₂ --CF _2- ) (tetrafluorocarbon) in its molecular structure in its skeleton, it has heat resistance and low friction coefficient due to a strong bond between C and F. Excellent. Among these, perfluoro-based tetrafluorocarbon resins such as PTFE, PFA, and FEP are all surrounded by a fluorine atom or a trace amount of an oxygen atom around a carbon atom as a skeleton, and a strong bond between C-F is formed. And, since the circumference of the carbon skeleton is protected by fluorine, it is excellent in heat resistance, low friction coefficient, lubricity, and also excellent in various properties such as non-adhesion, chemical resistance, etc., so that molten toner and dust, It is expected that dust and the like hardly adhere to the surface, and that the wear of the sliding surface due to the adhesion of foreign matter is expected to be reduced, and the sliding contact guide for sheet conveyance is excellent in heat resistance.

The heat deformation temperature (JIS K 7207) will be described as an example of the heat resistance evaluation criteria. The heat deformation temperature (JIS K 7207, 4.6 kgf)
/ Cm ² bending stress) of 50 ° C. or more, preferably 70 to
A fluorocarbon resin composition at 250 ° C. is preferable because the amount of deformation due to heat is small. Since the load is small under the use conditions such as the sliding guide for sheet conveyance in the invention of the present application, it is appropriate to judge under the bending stress condition of 4.6 kgf / cm ² .

The fluorocarbon resin is preferably used in the present invention in view of its excellent heat resistance. The upper limit of the crystal melting point is determined by the binding energy between fluorine and carbon and the binding energy between carbon atoms in the main chain. From a point of view,
The highest one is considered to be 400 ° C. or less. By the way,
The crystal melting point is a physical property exhibiting a thermal characteristic of 250 ° C. or higher.

The fluorocarbon resin preferably has a thermal decomposition temperature of 300 ° C. or higher, and more preferably has a thermal decomposition temperature of 400 to 550 ° C.
The thermal decomposition temperature referred to here is a temperature that can be measured by gravimetric analysis or the like, and specifically, thermal analysis (DSC, differential scanning calorimetry,
DTA, TDA, etc.) can be obtained from a thermobalance weight loss curve (TG) such as a thermobalance method and a differential thermal analysis curve (DTA). For example, a sample of 15 mg was heated at a heating rate of 1
Heat at 0 ° C./min in air or nitrogen gas to determine the temperature at which the specimen loses 5%, or the temperature at which the sample loses 5 mg, or the percent weight loss at each temperature, and The temperature corresponding to the weight% can be determined, and this can be determined as the 50% weight loss temperature by thermal decomposition.
It is also evaluated as the differential pyrolysis onset temperature.

According to the measurement method of JIS K7210, a fluorocarbon resin having a melt viscosity of 10 ³ to 10 ⁵ poise at a shear rate of 10 ² to 10 ⁴ (sec ⁻¹ ) has excellent injection moldability. Is preferred. The melt viscosity of the fluorocarbon resin is more preferably 10 ⁴ to 10 ⁵ poise from the viewpoint of injection moldability.

Incidentally, the melt viscosity of PFA and FEP is 3
10 ⁴ to 10 ⁵ poise at 80 ° C., 4 × 10 ⁴ to
10 ⁵ poise, and ETFE is 10 ⁴ to 1 at 300 ° C.
0 is ⁵ poise, also in PTFE 340~380 ℃
It is 10 ¹¹ to 10 ¹² poise, and a fluorocarbon resin having a viscosity characteristic of about 10 ³ to 10 ¹² poise even under such a high temperature is preferable because it has high viscosity characteristics and thus has excellent heat resistance. .

[0030] However, the melt viscosity at two hundred and eighty to three hundred and eighty ° C. exceeds ¹⁰⁷ poises, a large load on the cylinder, such as a melt molding machine during granulation and injection molding described later, the injection molding and stable granulation In consideration of heat resistance, moldability and mass productivity, the melt viscosity of the fluorocarbon resin at 280 to 380 ° C. is preferably 10 ³ to 10 ⁶ poise.

The above-mentioned PFA is a chain fluororesin having a perfluoroalkoxy side chain, and is obtained by modifying a homopolymer PTFE with a monomer containing a perfluoroalkoxy group, It is a copolymer containing a comonomer that gives a chain as an essential component.

The melt viscosity of such PFA, FEP and ETFE is determined by the evaluation method of ASTM D3307.
In the case of A or FEP, it is 370 to 380 ° C, specifically, it is evaluated by the specific melt viscosity at 372 ± 1 ° C.
In the case of FE, the specific melt viscosity at 290 to 300 ° C. is evaluated, and the specific melt viscosity of these injection-moldable fluorocarbon resins is 1 × 10 ³ to 1 × 10 ⁶ poise.
The melt flow index (melt flow rate) is from 1 to 36 g / 10 minutes, preferably from 1 to 18 g / 10 minutes, and from 3 to 18 g / 10 from the viewpoint of compatibility between injection moldability and heat resistance. Minutes (ASTM D330
7) is more preferable.

The alkyl group of PFA has about 1 to 10 or 1 to 4 carbon atoms, and the alkyl group may be a methyl group, an ethyl group, a propyl group, a butyl group, or the like. The proportion of one or more kinds of alkyl groups constituting the resin in the resin is 0.1 to 10% by weight, preferably 1 to 8% by weight, more preferably 3 to 6% by weight. FE
The hexafluoropropylene portion of P is 8 to 16% by weight,
Preferably, the ratio is 8 to 10% by weight. With such a ratio, both PFA and FEP have the optimal melt viscosity,
It becomes a sliding contact guide for sheet conveyance that is excellent in moldability and heat resistance. In consideration of various properties such as heat resistance, non-adhesion, and melt viscosity, it is preferable that the alkyl group portion of PFA is mainly a propyl group.

On the other hand, hydrogen-containing fluorocarbon resins such as ETFE, PCTFE, PVDF, etc.
Compared with a relatively flexible resin group such as FA and FEP, it is preferable because of its high mechanical strength and excellent abrasion resistance. Among them, ETFE has heat resistance with a glass transition point of about 100 ° C. or higher and good impact resistance. For example, since ETFE does not break even in a notched Izod impact test at room temperature, inadvertent cracking of the molded product occurs. It is considered that no such phenomenon occurs. Due to such ETFE characteristics, a resin molded article mixed with a fibrous reinforcing material in order to improve heat deformation temperature, flexural modulus and abrasion resistance,
However, the adverse effect of the addition of the fibrous reinforcing material such that the impact strength is reduced can be compensated.

The composition ratio of the tetrafluoroethylene portion to the ethylene portion in ETFE is from 70:30 to 3
The ratio may be in the range of 0:70, preferably in the range of 40:60 to 60:40. Since the crystal melting point of ETFE is maximized when the content of tetrafluoroethylene is about 50 mol%, the ratio is from 45:55 to 55:55.
A range of 45 is considered more preferable in terms of heat resistance. In addition, a small amount of the third
A component may be contained.

When the above-mentioned PTFE is powdered and added to a hydrogen-containing fluorocarbon resin other than PTFE, for example, ETFE, the particle size is 70 μm.
m or less, a perfluoro-based and tetrafluorocarbon-based resin powder such as a PTFE powder or a PFA powder is preferable for homogenizing the composition, and the preferred particle size is 1 to 50 μm, more preferably 3 to 30 μm. When importance is attached to the mechanical property value of the sliding contact guide for sheet conveyance, fibrous PTF
E powder (virgin PTFE powder) may be used.

In the present invention, more preferable results can be obtained by using recycled PTFE instead of virgin PTFE. Recycled PTFE powder is a powder obtained by baking a virgin material once and then pulverizing the virgin material. The PTFE powder has a property of hardly forming a fibrous shape. It does not significantly increase the melt viscosity of the product and does not hinder injection moldability. Moreover, since the recycled PTFE powder is once baked, it is an additive that can provide a stable molded product without causing dimensional change, shape change, or cracking of the resin molded product mixed with the PTFE powder. Commercially available recycled PTFE powders include, for example, KT300M, KT300H, manufactured by Kitamura Corporation.
KT400M, KT400H, KTL610 and the like.

Further, instead of or in combination with regenerated PTFE, PTFE is subjected to γ-ray irradiation to reduce the molecular weight of P
TFE powder can be used. Commercially available PTFE for lubricants that have been gamma-ray treated include KTL610 manufactured by Kitamura Corporation.
And the like.

PTFE powder, reclaimed PTFE powder, PFA powder, F
When a perfluorotetrafluoroethylene such as EP powder is added to improve non-adhesion and avoid damage to a sliding partner, the proportion of the perfluorotetrafluoroethylene in the total composition is as follows. 1 to 25% by weight, preferably 2 to 20% by weight, more preferably 5 to 1% by weight.
5% by weight. If the amount is less than the predetermined range, the sliding characteristics of the sheet conveying sliding contact guide will not be improved, and if the amount exceeds the predetermined range, the moldability will be degraded.

The number average molecular weight (Mn) of the fluorocarbon resin is preferably from 1 × 10 ⁴ to 1 × 10 ⁸ . This is because those having a number average molecular weight smaller than the predetermined range do not have abrasion resistance, and those having a number average molecular weight larger than the predetermined range make injection molding difficult and difficult to form efficiently. From such a tendency, a more preferable number average molecular weight (Mn) is
It is 1 × 10 ⁵ to 1 × 10 ⁷ , and when importance is placed on injection moldability, it is 1 × 10 ⁵ to 1 × 10 ⁶ .

Further, in the slidable contact guide for sheet conveyance or the cavity of the slidable contact guide for sheet conveyance of the injection molding die, a sliding portion where the slidable contact guide for sheet conveyance and the sheet frictionally contacts the sheet smoothly. The surface shape and the surface roughness are preferably small in order to allow the sheet to pass therethrough or to improve the releasability of the sliding contact guide for conveying the sheet from the injection molding die.

Such surface shape, roughness and shape roughness are, for example, maximum roughness (Rmax), arithmetic average roughness (R
a) The ten-point average roughness (Rz) is measured by an evaluation method defined by JIS, and the value is, for example, 25 μm or less according to the arithmetic average roughness (Ra) evaluation method.
Or less, more preferably 3.2 μm or less. If the surface roughness exceeds the above value, the sliding surface is likely to have many scratches, which is considered to cause wear.
In addition, the releasability of the sliding guide for sheet conveyance from the injection mold is inferior, and the manufacturing process is inefficient and the yield is reduced.

The lower limit of the surface shape and roughness is set to 0.1 μm in consideration of the efficiency at the time of precision cutting of the cavity surface and the support shaft of the injection molding die and the sliding guide for sheet conveyance.
m or 1 μm or more in consideration of workability. In addition, since it takes a long time for processes such as finishing of the injection mold and the support shaft surface, it is inefficient and may be affected by the formation of a transition film of the resin material, so that it is not affected by abrasion. It is considered that the surface shape and roughness of each of the above may be in the range of about 2 to 8 μm as long as the specifications and conditions are satisfied. It is considered that when the surface roughness is small, the contact angle of the water droplet becomes larger, and the non-adhesion can be improved.

The hardness of the sliding guide for sheet conveyance is as follows.
For example, Shore hardness (ASTM D2240, <JIS
K 7215>, durometer with a durometer)
The hardness is preferably D90, more preferably D50 to D80. If the hardness is too low, it is considered that it may cause abrasion of a portion of the sliding contact guide that comes into contact with a counterpart member, or a portion of the sliding member that contacts the transfer paper due to contact or sliding of the OHP transfer member or the transfer paper. It is considered that it is difficult to suppress damage to the portion of the sliding contact guide that comes into contact with the mating member, and also to the PPC sheet and the OHP transfer member.

In order to achieve such hardness, various fillers such as organic fillers and inorganic fillers (granules such as flakes and spheres, and various shapes such as fibers) may be added as needed. ~
What is necessary is just to mix 50 weight%. The various fibrous fillers such as whiskers will be described later in detail.

The non-adhesiveness of the surface of the resin molded body forming the sliding contact guide for sheet conveyance of the image forming apparatus can be determined by measuring the contact angle of water droplets adhering thereto. For example, if the contact angle of a water drop is 80 ° or more,
In the present invention, the resin molded article is considered to have sufficient non-adhesiveness, and a more preferable contact angle is 90 ° or more.

Incidentally, the contact angle can be measured, for example, by using a goniometer type contact angle tester manufactured by Elma Optical Co., Ltd. at a normal temperature and a normal pressure in a droplet of 0.01 to 0.1 ml, preferably 0.05 ml. Is typically dropped on the surface of the test piece and the contact angle is measured for 1 minute (30 seconds and 1 minute) immediately after the drop, but is not limited to such a measurement method. Needless to say, a measuring method may be used.

The fibrous reinforcing material used in the present invention preferably has a fiber diameter of 0.05 to 8 μm and a fiber length of 1 to 100 μm, and particularly has a fiber diameter of 0.1 to 3 μm and a fiber length of 1 to 40.
μm is preferred. Because, if the fiber diameter and the fiber length are smaller than the predetermined range, the wear resistance of the fluorocarbon resin cannot be improved, and there is no reinforcing effect,
If the thickness exceeds the predetermined range, the above-mentioned surface roughness becomes larger than a required range, and it becomes impossible to form a square end precisely.

Specific examples of the fibrous reinforcing material include potassium titanate whiskers, aluminum borate whiskers, magnesium borate whiskers, zinc oxide whiskers, titanium oxide whiskers, calcium carbonate whiskers, aluminum sulfate whiskers, calcium sulfate whiskers, and magnesium sulfate whiskers. , Calcium silicate whiskers, wollastonite whiskers, silicon nitride whiskers, silicon carbide whiskers, various types of ceramic whiskers such as alumina whiskers, various whiskers containing silicon oxide as a main component, mineral whiskers obtained by melting and processing igneous rock, Examples include carbon fiber, glass fiber, and graphite fiber.

The potassium titanate whisker is, for example, K _{2
O · 6TiO 2, K 2 O} · 6TiO 2 · 1 / 2H 2 O
Or K ₂ Ti ₂ O ₅ , K ₂ Ti ₄ O ₉ , K ₂ Ti
₆ O _13, K, such as ₂ Ti ₈ O _17, formula K ₂ O · n
And potassium titanate whiskers represented by TiO ₂ (n is an integer of 1 or more or an even number of 2 or more). These have a true specific gravity of 3.0 to 3.6, 3.2 to 3.3 depending on the type, a melting point of 1300 to 1400 ° C, and are produced by a flux method or a melt method.

The flux method uses a raw material (Ti
A mixture of O ₂ , K ₂ CO ₃ ) and a flux is melted and gradually cooled to synthesize K ₂ Ti ₄ O ₉ whiskers (primary compound). Then, this whisker is treated with a dilute acid aqueous solution or boiling water to extract a part of K between the layers and denature the composition,
It is heat-treated at 1000 ° C. and has a tunnel structure K
₂ Ti ₆ O ₁₃ whisker is synthesized as a secondary compound. The whisker size is 0.1-0.5 μm in diameter and 1 in length.
Many are about 50 μm, and commercially available products include Tismo N, Tismo L, and Tismo D manufactured by Otsuka Chemical Co., Ltd.

In the melt method, a raw material is mixed with K ₂ Ti ₂ O ₅ at an equivalent stoichiometric composition ratio, melted at 1100 ° C., and the melt is quenched and solidified to form acicular K ₂ Ti ₂ O ₅ . It is synthesized as a primary compound. Next, this whisker is treated by a composition / structure conversion process in the same manner as K ₂ Ti ₄ O ₉ to synthesize a K ₂ Ti ₆ O ₁₃ whisker as a secondary compound. The whisker size is characterized by being thicker than the flux method.
0-30 μm, about 80-500 μm in length, or 0.5-2.0 μm in diameter, 10-50 μm in length
There are many grades, and commercially available products include Teazax A and Teazax B manufactured by Kubota Corporation.

For aluminum borate whiskers,
It may be whitened by adding S (sulfur) thereto, but may have the chemical formula 9Al ₂ O ₃ .2B ₂ O ₃ or 2A
a white needle crystal represented by _{l 2 O 3 · B 2 O} 3,
Average fiber diameter 0.05-5μm, average fiber length 1-100μ
m.

[0054] aluminum borate whisker represented by _{9Al 2 O 3 · 2B 2 O} 3 is a true specific gravity from 2.93 to 2.9
5, having a melting point of 1400 to 1500 ° C, at least one of aluminum hydroxide and aluminum inorganic salt,
At least one of boron oxide, oxyacid and alkali metal salt in the presence of a flux comprising at least one of alkali metal sulfate, chloride and carbonate;
It is manufactured by heating to 00 ° C. to react and grow.

On the other hand, aluminum borate whisker represented by _{2Al 2 O 3 · B 2 O} 3 is a true specific gravity 2.92～
2.94, melting point 1000-1100 ° C, 9Al ₂ O ₃
・ Using the same components as those for producing B ₂ O ₃ ,
It can be produced by heating to 00 to 1000 ° C. to react and grow.

In order to further enhance the reinforcing effect of these aluminum borate whiskers and various whiskers, a surface treatment with a coupling agent may be performed. In this case, a silane-based or silicon-based coupling agent may be used. , Titanium, aluminum, zirconium, zirconaluminium, chromium, boron, phosphorus, epoxy, amino acid, modified silicone oil and the like.

Preferred commercial products of aluminum borate whisker include Albolex Y, manufactured by Shikoku Chemicals.
Alborex G, etc., and the average fiber diameter is 0.1.
5-1 μm, average fiber length is 1-30 μm.

In addition, whiskers other than those described above include P
General formula TiO such as yellow or gray tetrapot containing impurities such as b and Cd, or zinc oxide whisker (ZnO) or rutile-type white needle-like crystal in which these are broken and conical or tapered Titanium oxide whiskers ₂ and the like can also be used in the present invention.

Incidentally, the average diameter of general whiskers is as follows:
In the present invention, the average diameter is preferably 0.05 to 8 μm as described above. Furthermore, the average length of common whiskers is 1 μm or more, and is 1 to 300 μm on average, and some reach 50 to 60 mm (aspect ratio is 1 to 200). In the present invention, a fiber having a fiber length of 1 to 100 μm is preferable for the above-described reason.

When the above-mentioned whiskers are employed as the fibrous reinforcing material of the present invention, injection molding and, if necessary, cutting, are carried out, so that dimensional accuracy is improved, reinforcement is achieved, and burrs are reduced. A sliding contact guide for sheet conveyance is obtained.

The fibrous reinforcing material such as a whisker used in the present invention has a Mohs hardness of 1 to 10 in consideration of damage to a mating member with which the sliding guide for sheet conveyance slides.
Are preferred, and more preferably 3 to 9. If the Mohs' hardness is too low, the reinforcing property cannot be expected, and if it is too high, it is difficult to suppress the damage of the sliding member.

As the Mohs hardness, any of the evaluation test criteria of the new Mohs hardness and the old Mohs hardness may be employed.
The Mohs hardness described in the present application is evaluated based on the old Mohs hardness. In this case, for example, a Mohs hardness of 5 may be regarded as one critical point, a material having a Mohs hardness of less than 5 may be evaluated as having a low hardness, and a material having a Mohs hardness of 5 or more may be evaluated as having a high hardness.

Whiskers having such hardness include potassium titanate whiskers, calcium carbonate whiskers, wollastonite whiskers, magnesium sulfate whiskers, aluminum borate whiskers, and the like. Particularly preferred are potassium phosphate whiskers and aluminum borate whiskers.

Whiskers such as potassium titanate whiskers and aluminum borate whiskers in the resin composition are:
The pellets are broken during granulation or molding, and the average fiber length becomes less than 10 μm.
It is thought to be. Whisker of such dimensions has a very smooth surface of the sliding guide for sheet conveyance without impairing the flowability during injection molding, improves non-adhesiveness, and is a molded product of the sliding guide for sheet conveyance. The burr is reduced at the corners of.

The mixing ratio of the fibrous reinforcing material described above in the resin composition is such that the fluorocarbon resin is 65 to 10%.
0% by weight, 0 to 35% by weight of fibrous reinforcing material, preferably 2%
２５25% by weight. If the amount of the fibrous reinforcing material exceeds 35% by weight, the non-adhesion of the fluorocarbon resin to the toner or the like is impaired, which is not preferable.

The UL standard for flammability indicated by the physical property values of the fluorocarbon resin will be described below. The flammability test method specified in UL94 includes two test methods, a horizontal flammability test 94HB and a vertical flammability test 94V. In general, a 94V evaluation method is applied to flame-retardant materials, and UL94V-0 ( Hereinafter, it is abbreviated as V-0.)
Is the strictest certification standard.

Here, as a characteristic relating to flame retardancy, the limiting oxygen index (ASTM D 2863, JIS K 7201) indicated by the physical property value of the fluorocarbon resin described above.
Will be described below. For example, PTFE, PFA,
FEP and PCTFE have a limiting oxygen index of 95% by volume or more and are nonflammable. ETFE has a limiting oxygen index of 3
0 vol%, which is less self-extinguishing than PFA, FEP, etc. However, if the limiting oxygen index is 27 vol% or more and 100 vol% or less, it has self-extinguishing properties. It can also be used accordingly. However, if importance is attached to safety against flammability, the limiting oxygen index is preferably at least 50% by volume or more, preferably 80 to 100% by volume.

As shown in FIG. 2, the shape of the sliding contact guide for sheet conveyance of the image forming apparatus is not only a rectangular plate having an arc-shaped edge but also a sheet such as a sphere, an elliptical sphere, a column, a disk, an elliptic plate, and the like. It may have a curved surface for guiding a flat surface, or may have a step or groove formed for guiding the edge of the sheet.

Further, in the sliding contact guide shown in FIG. 2, only the surface layer of the sliding contact surface (arc surface) with the sheet is formed of a resin composition containing a fluorocarbon resin as a main component, and other portions are formed of another resin or other resin. Shown are composite moldings made of metal and the like. However, the sliding contact guide may, of course, be integrally molded with a resin composition containing a fluorocarbon resin as a main component, including the sliding contact surface with the sheet. It may be molded. Reference numeral 15 in FIG. 2 denotes a mounting hole for the image forming apparatus, which may be mounted so as to be swingable or fixed so as not to swing as required.

The volume of such a sliding contact guide is 3000
Those having a size of 0 mm ³ or less are preferred. This is because a molded product exceeding a predetermined volume has a large "sink" and it is difficult to maintain dimensional accuracy. Moreover, since hardly molded are small less than a predetermined volume, more preferably 10～10000Mm ^3, more preferably from 50~5000mm ^3.

The sliding contact guide for conveying a sheet of the image forming apparatus according to the present invention forms a recording pattern on a medium such as a photoreceptor in response to an externally applied electric signal, and controls the amount of electricity formed on the medium. It is needless to say that the present invention can also be applied to printers employing various methods for converting the above-mentioned pattern into a visible pattern. Examples of such a printer system include an electrophotographic system, an inkjet system, a thermal system, an optical printer system, and an electronic recording system.
The types of the electrophotographic method described above include the Carlson method,
Light / charge injection method, photo polarization method, photovoltaic method, charge transfer method,
Electrolytic electrophotography, electrostatic latent image photography, photoelectrophoresis, and thermoplastic method are exemplified. In addition, examples of the optical printer include a laser printer, an LED (light emitting diode) printer, a liquid crystal shutter printer, and a CRT printer. Examples of the electronic recording method include an electrostatic recording method, an energization recording method, an electrolytic recording method, and a discharge recording method.
Furthermore, there are a direct method and an indirect method. Among these electrostatic recording methods and the like, there are methods such as a wet method in which oil or the like is applied and a dry method for the method.

More specifically, light emitting diodes (LEDs) such as a toner image transfer type wet electrostatic copying machine, a dry electrostatic copying machine (PPC), a laser beam printer (LBP), a liquid crystal shutter (LCD) printer, and a facsimile printer. L
ED) and a general concept of an image forming apparatus such as a printing machine such as a printer such as a printer using a silver halide photography (CRT).

Further, the sliding guide for sheet conveyance of the image forming apparatus according to the present invention is not particularly limited in the arrangement portion in the image forming apparatus, such as a paper discharge section such as a photosensitive section, a developing section, and a fixing section. is not. If the excellent heat resistance of the fluorocarbon resin is applied, the photosensitive section, the fixing section used at a higher temperature than the developing section, and the sliding contact guide for sheet conveyance mainly used on the downstream side in the conveyance direction of the transfer paper from the fixing device. It is suitable as.

[0074]

EXAMPLES Raw materials used in Examples and Comparative Examples of the present invention are collectively shown below. In addition, in [],
Heat deformation temperature (under bending stress of 4.6 kgf / cm ² , JI
SK 7207), melting point, thermal decomposition temperature, melt viscosity, number average molecular weight, hardness (ASTM D2240,
JIS K 7215), limiting oxygen index (ASTM)
D2863), flame-retardant UL94 standards are shown in this order, and all numerical values are representative values.

(1) Polytetrafluoroethylene (PT
FE-1) DuPont: Teflon 7J [121 ° C, 327
° C, about 508 to 538 ° C, 10 ¹¹ to 10 ¹² poise (340 to 380 ° C), about 10 ⁶ to 10 ⁷ , D50
~ D65, 95% by volume or more, V-0] (2) Recycled polytetrafluoroethylene (PTFE-
2) Kitamura Co., Ltd .: KTL610 (average particle size: 10 to 20 μm) (3) Tetrafluoroethylene-perfluoroalkylvinyl ether copolymer (PFA) Asahi Glass Co., Ltd .: Aflon PFA P-63 [74 ° C.
300 to 310 ° C, 464 ° C or higher, 10 ⁴ to 10 ⁵
Poise <380 ° C>, (2-3) × 10 ⁵ , D60
~ D64, 95% by volume or more, V-0] (4) Tetrafluoroethylene-hexafluoropropylene copolymer (FEP) Asahi Glass Co., Ltd .: Aflon FEP H-330B [72]
° C, 250-282 ° C, 419 ° C or higher, 4 × 10
⁴ to 10 ⁵ poises <380 ° C>, (3 to 5) x 1
0 ^5, D60~D65,95% by volume or more, V-
0] (5) Tetrafluoroethylene-ethylene copolymer (E
TFE) Asahi Glass Co .: Aflon COP C88A [89-10
4 ° C, 260-270 ° C, 347 ° C or more, 10 ⁴
〜１０10 ⁵ poise <300 ° C.>, 1 × 10 ⁵ , D7
(5, 30% by volume, V-0) (6) Aluminum borate whisker (whisker-1) manufactured by Shikoku Chemicals: Arbolex Y (fiber diameter 0.5 to
1 μm, fiber length 10 to 30 μm, Mohs hardness 7) (7) Potassium titanate whisker (whisker-2) manufactured by Otsuka Chemical: Tismo N (fiber diameter 0.1 to 0.3 μm)
m, fiber length 20 to 30 μm, Mohs hardness 4) (8) Polyphenylene sulfide (PPS) manufactured by Tohsosa Steel Co .: GS40 (9) Polyacetal (POM) manufactured by Polyplastics: Duracon AW-01.

[Examples 1 to 8, Comparative Examples 1 and 2] In Example 1, after the respective raw materials were dry-mixed, a preform was formed by compression molding, which was removed from the mold and fired. A sliding contact guide for conveyance was formed from the obtained molded body into a shape shown in FIG. 2 by machining such as cutting.

In Examples 2 to 8 and Comparative Examples 1 and 2, the raw materials were melt-mixed at the compounding ratios shown in Table 1, and the pellets formed by granulation were subjected to an injection molding machine under conditions suitable for each resin. Injection molding was performed to produce a sliding guide for conveyance having a shape shown in FIG.

The physical properties of these sliding guides were evaluated by the following test methods, and the results are summarized in Table 1.

(1) Actual Machine Test The sliding contact guide is used under the most severe conditions in the fixing device of a dry electrostatic copying machine (high temperature, high non-adhesion to the toner in FIG. 1). No. 10) Eight pieces are mounted in parallel at regular intervals at the position, 30,000 sheets of A4 size copier paper are continuously passed, copying is repeated 30,000 times, and sheets are printed every 10,000 sheets to check the image state. Observed. (A) Adhesiveness of toner The toner contact was not observed at all in the sliding contact guide, and the toner adhering was marked as x.
It was rated on a scale. (B) Heat resistance The sliding contact guide was evaluated in two steps, in which no deformation was recognized as 印, and the one in which deformation was recognized was evaluated as ×. (C) Abrasion resistance The sliding contact surface of the sliding contact guide with the sheet (copy paper) was evaluated as a two-point scale, with no wear observed and a x-marked wear surface. (D) Image state When copying is repeated 30,000 times, the image state of a sheet (copy paper) is observed every 10,000 sheets.
Marks and those that were unclear were evaluated in two steps as x marks.

(2) Physical property test (e) Non-adhesiveness The contact angle of a water droplet was determined using a goniometer type contact angle measuring device manufactured by Elma Optical Co., Ltd. The evaluation was made with less than x. (F) Moldability Regarding whether or not it is suitable for mass production, a mark indicates that injection molding is possible, and a mark indicates that injection molding is impossible but compression molding is possible and does not require post-processing. Those that cannot be injection-molded and require post-processing in compression molding were evaluated with x. (G) Flame retardancy Evaluated based on UL standard, UL94. (H) Wear resistance Using a thrust abrasion tester, inner diameter φ17 × outer diameter φ21
× 150 ° C, 0.5k load with a 10mm long cylindrical test piece
gf, rotation speed 200rpm, mating stainless steel SUS3
04. A test was performed under non-lubricated conditions to determine the amount of wear (mg).

[0081]

[Table 1]

As is clear from the results shown in Table 1, Examples 2 to 8 can be injection-molded, have good moldability, and are excellent in heat resistance, flame retardancy and abrasion resistance of sliding surfaces. In addition, it was found that the sliding contact guide was excellent in non-adhesiveness, did not adhere toner, and provided a clear image. In Example 1, physical properties other than moldability and actual machine performance were excellent.

The embodiments 2, 3 and 4 made of PFA, FEP and ETFE are sliding contact guides which can be manufactured at low cost because they can be manufactured by the injection molding method, and can be formed into complicated shapes, so that productivity can be improved. The efficiency was excellent.

On the other hand, in Comparative Examples 1 and 2, toner adhesion was observed, and heat resistance and non-adhesion (non-adhesion of toner) were inferior.

[0085]

The sliding guide for conveying a sheet of an image forming apparatus according to the present invention can meet the demands for a higher processing speed of the image forming apparatus and a reduction in the size of the apparatus main body. There is an advantage that it is a sliding contact guide for sheet conveyance of an image forming apparatus having excellent abrasion and non-adhesion of toner.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a schematic configuration of a fixing device.

FIG. 2A is a front view of a sliding contact guide for sheet conveyance. FIG. 2B is a side view of a sliding contact guide for sheet conveyance.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heater 2 Fixing roller 3 Pressure roller 4 Conveyor belt 5 Sheet 6 Inlet guide 7 Separation claw 8 Discharge roller 9 Discharge roller 10, 11, 12, 13 Sheet sliding contact guide 14 Toner image 15 Mounting hole A Fixing device

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI C08L 27/12 C08L 27/12 // B29K 27:12

Claims (10)

[Claims] A sliding guide that slides on a sheet conveyed in the apparatus after image formation and guides the sheet;
A sliding guide for conveying a sheet of an image forming apparatus, wherein the sliding contact guide is formed of a resin composition containing a fluorocarbon resin as a main component. 2. A sheet conveying slide for an image forming apparatus according to claim 1, wherein the resin composition containing a fluorocarbon resin as a main component is a resin composition containing a fluorocarbon resin as a main component and a fibrous reinforcing material added thereto. Contact guide. 3. The fibrous reinforcing material has a fiber diameter of 0.05 to 0.05.
3. The sliding guide according to claim 2, wherein the guide is a fibrous reinforcing material having a fiber length of 8 [mu] m and a fiber length of 1 to 100 [mu] m. 4. The sliding contact guide for conveying a sheet of an image forming apparatus according to claim 1, wherein the fluorocarbon resin is a tetrafluoroethylene resin. 5. The method according to claim 1, wherein the tetrafluoroethylene resin is
5. A perfluorotetrafluoroethylene.
A sliding guide for conveying a sheet of the image forming apparatus according to the above. 6. The fluorocarbon resin according to claim 1, wherein the fluorocarbon resin is a melting type fluorocarbon resin having a crystal melting point of 250 ° C. or higher and a melting point viscosity at 280 to 380 ° C. of 1 × 10 ³ to 1 × 10 ⁶ poise. Claim 1
The sliding contact guide for sheet conveyance of the image forming apparatus according to any one of claims 1 to 3. 7. The sheet conveying slide according to claim 1, wherein the fluorocarbon resin is a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer. Contact guide. 8. The sliding contact guide for sheet conveyance of an image forming apparatus according to claim 1, wherein the fluorocarbon resin is a tetrafluoroethylene-hexafluoropropylene copolymer. 9. The sliding contact guide for sheet conveyance of an image forming apparatus according to claim 1, wherein said fluorocarbon resin is a tetrafluoroethylene-ethylene copolymer. 10. A method of manufacturing a sliding guide for conveying a sheet of an image forming apparatus, comprising: forming a sliding guide for conveying a sheet of an image forming apparatus by injection molding with a fluorocarbon resin.