JPH09273542A - Pressure roller and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve adhesiveness of a fluorocarbon resin sleeve and silicone rubber, and manufacture a pressure roller efficiently by using the silicone rubber whose liner contraction coefficient is a specified value or less and which is used in a elastic body layer. SOLUTION: The outer peripheral part of a core 2 is covered with an elastic body layer 3 in a pressure roller 1, and the outer peripheral part thereof is covered with a fluorocarbon resin sleeve 4. Silicone rubber whose liner contraction coefficient is 2.0% or less is used as a silicone rubber layer whose hardness is 3 degree or less with which the outer peripheral part of the core 2 is covered, and the outer peripheral part thereof is covered with the fluorocarbon resin sleeve 4 whose thickness is 0.1mm and less, and thereby, it is difficult to receive thermal expansion and contraction in the silicone rubber so as to eliminate wrinkle generated on the fluorocarbon resin sleeve 4 while improving adhesiveness of the fluorocarbon resin sleeve 4 with which the outer peripheral part of the silicone rubber layer is covered at the time of forming.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure roller in a fixing section of an electronic copying machine or a laser beam printer (hereinafter abbreviated as LBP) and a method for manufacturing the pressure roller.

[0002]

2. Description of the Related Art Conventionally, in order to improve toner releasability as a pressure roller in a fixing section of an electronic copying machine or an LBP,
A roller is known in which the outer circumference of a cored rubber roller is covered with a fluororesin sleeve. In the conventional roller of this type, both ends of a fluororesin sleeve having an outer diameter smaller than the inner diameter of the cylindrical mold loaded inside the inner peripheral surface of the cylindrical mold are fixed to a side mold for holding a core metal, In this state, the rubber material is injected and filled into the annular space between the core metal and the sleeve at a high pressure, and the sleeve is integrated with the inner peripheral surface of the cylindrical mold while expanding the sleeve by the filling pressure. It was produced by a method of converting it (see Japanese Patent Publication No. 50-7097 and Japanese Patent Publication No. 51-27276).

[0003]

In recent years, as the copiers and LBPs have been designed to be compact and the pressure roller in the fixing section has a smaller diameter, the hardness of the silicone rubber layer has become lower. And in the conventional pressure roller, the wall thickness is especially
The thin fluorine resin sleeve having a thickness of 0.1 mm or less has a defect that wrinkles are easily formed in the axial direction, and there are cases where the pressure roller cannot be stably supplied.

Japanese Patent Laid-Open No. 7-334024 can be cited as a conventional example of the measure for the wrinkle generation of the fluororesin. The above-mentioned publication discloses a pressure roller made of silicone rubber having a specific gravity of 1.20 to 1.40 and a repulsion elastic modulus of 20 to 55% as an elastic layer of the pressure roller. However, even if the composition having the specific gravity and the impact resilience defined in the publication as described above is applied to the silicone rubber, wrinkles may occur. The above-mentioned publication points out that the above-mentioned wrinkles occur due to repeated use over a long period of time, and the cause thereof is repeated thermal expansion and thermal contraction.

By the way, looking at the silicone rubber used as the elastic layer of the pressure roller, the specific gravity of the polyorganosiloxane which is the base gum of the silicone rubber is
It is 0.98, and the specific gravity of the final composition can be established by adding various fillers to this base gum.By adding a filler having a low specific gravity, the specific gravity of the composition is light, and on the contrary, the specific gravity is heavy. The addition of the filler increases the specific gravity of the composition, and it cannot be considered that this is a parameter directly related to the function and processability of the pressure roller.

Further, a composition having a low hardness has a low stress so that the surface layer is largely deformed at the time of thermal expansion. However, it is considered that the higher the repulsion elastic modulus is, the easier it is to maintain the shape and the less wrinkles are formed. Therefore, the impact resilience tends to decrease as the filling rate of the filler increases, and the composition with high filling, that is, the composition with high specific gravity tends to decrease the impact resilience.

As described above, wrinkles are caused by repeated thermal expansion and contraction,
As a countermeasure against the occurrence of wrinkles, only controlling the specific gravity of the rubber composition used for the elastic body has a small effect, and rather controlling the heat shrinkage of the rubber should be more effective. By making it smaller, the elastic layer of the roller is less likely to undergo thermal expansion and contraction, and it is considered that wrinkles that occur in PFA (copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether) on the surface layer can be avoided.

The present invention has been made in view of the above points, and a pressure roller having excellent adhesiveness between a fluororesin sleeve and a silicone rubber, and a pressure capable of efficiently manufacturing the pressure roller. It is intended to provide a method for manufacturing a roller.

[0009]

In order to achieve the above-mentioned object, the present inventors efficiently manufacture a pressure roller having excellent reliability of adhesion between a fluororesin sleeve and rubber, and this pressure roller. As a result of earnest research to obtain a pressure roller manufacturing method capable of producing a pressure roller, there is a correlation between the linear shrinkage ratio of the silicone rubber used for the elastic layer and the wrinkles generated on the surface fluororesin sleeve. The present invention has been completed by finding that wrinkles occurring on the surface layer of the pressure roller can be avoided by using a silicone rubber having a rate of 2.0% or less.

That is, the pressure roller according to the present invention is a pressure roller in which a fluororesin sleeve having a thickness of 0.1 mm or less is coated on the outer periphery of a silicone rubber layer having a hardness of 30 degrees or less which is coated on the outer periphery of a core metal. The silicone rubber layer is characterized by using a silicone rubber having a linear shrinkage ratio of 2.0% or less, and the method for producing the same is such that metallic sodium is contained in liquid ammonia on the inner surface of a fluororesin sleeve having a thickness of 0.1 mm or less. After the surface treatment is performed using the dissolved treatment liquid or the treatment liquid in which naphthalene and metallic sodium are dissolved in an organic solvent, the adhesive treatment is applied using an adhesive, and the fluororesin sleeve subjected to this adhesion treatment After fixing both ends to the side mold that holds the cored bar that has been adhesively processed in advance with an adhesive, hold it in the cylindrical mold and place it in the annular space between the cored bar and the sleeve. The shrinkage is 2.0% or less silicone rubber is injected, is to its characterized in that the heating vulcanization to integrate the silicone rubber the fluororesin sleeve.

More specifically, the cause of wrinkles is that the roller that has been heat-molded at the time of molding the roller is cooled to room temperature, and then secondary vulcanization is usually performed at a temperature of about 200.degree. When the roller is subjected to repeated heating and cooling, it undergoes thermal expansion and contraction, and the PFA on the surface layer undergoes plastic deformation, and the PFA layer and the silicone rubber layer are bonded, so the rubber contracts at the bonding surface. It is considered that the PFA layer is wrinkled due to abnormal contraction in the 90 ° direction.

As described above, wrinkles are caused by repeated thermal expansion and contraction,
It is considered that controlling the specific gravity of the rubber composition used as an elastic body is not effective as a measure against the occurrence of wrinkles, and rather controlling the heat shrinkage of the rubber is more effective. By making it smaller, the elastic layer of the roller is less susceptible to thermal expansion and contraction, and it is considered that wrinkles that occur in the PFA on the surface layer can be avoided.

As a test method for measuring the degree of heat shrinkage, JIS C 2123 defines a linear shrinkage rate test.
The linear shrinkage ratio in the present invention is measured according to the above JIS C 2123. In the present invention, for example, in addition type silicone rubber, the compound has a depth of 2 mm,
Place in a mold of size 130 × 130 mm at room temperature, and
After vulcanizing at a pressure of about 30 kg / cm ² for 10 minutes (10 minutes is the time after the mold reaches 120 ° C) with a press preheated to 0 ° C, it is allowed to cool to room temperature, and 200 in a constant temperature bath
After secondary vulcanization at 4 ° C for 4 hours, allow to cool to room temperature, measure the two lengths connecting the midpoints of opposite sides with a caliper to a reading of 0.1 mm, and measure the average value after vulcanization. The length of one side of the test piece is defined as the linear shrinkage rate measured by the following formula.

[0014]

[Equation 1]

Generally, important factors that determine the shrinkage rate of rubber are the vulcanization temperature, the vulcanization system, and the free volume fraction in the rubber. First, regarding the effect of vulcanization temperature,
Generally, the higher the vulcanization temperature (molding temperature), the larger the linear shrinkage rate becomes. Also, due to the influence of the vulcanization system, the cross-linking chain length of the polymer is short, and a compact structure is less likely to shrink. This means that the addition type silicone rubber is difficult to shrink between the peroxide vulcanizable millable silicone rubber and the addition vulcanizing liquid silicone rubber. The reason will be described below.

In the peroxide vulcanizing type silicone rubber, an organic peroxide such as 2,5-dimethyl-2,5-di (t-butylperoxy) -hexane is used as a vulcanizing agent. Therefore, it is usually molded at a high temperature of about 160 to 210 ° C. On the other hand, addition-type silicone rubber has a high vulcanization rate, so it is usually molded at a temperature of about 90 to 140 ° C, and it can be molded at a temperature about 70 degrees lower than that of peroxide-vulcanized silicone rubber. From the viewpoint, it can be said that the addition type silicone rubber is less likely to shrink.

Further, the polymer used in the silicone rubber is mostly dimethylpolysiloxane, and the average degree of polymerization is 100 to 1,000 in the case of the liquid type used in the addition type silicone rubber, and the addition of peroxide is 6,000 to 1 for the millable type used for vulcanized silicone rubber
It can be said that the addition type silicone rubber is less likely to shrink because of its molecular structure because it is a linear polymer of about 000.

Further, the free volume is substantially
Since it depends on the organic material portion of the rubber composition, increasing the amount of the inorganic filler reduces the shrinkage. From this fact, the linear shrinkage ratio of rubbers having the same molding temperature and vulcanization system is practically determined by the amount of the filler. Therefore, by molding the pressure roller of the present invention according to the method of manufacturing the pressure roller of the present invention, wrinkles do not enter into the fluororesin of the surface layer at the time of manufacturing the pressure roller, and excellent durability is obtained. The pressure roller can be obtained.

[0019]

The pressure roller according to the present invention has a linear shrinkage ratio as a silicone rubber layer having a hardness of 30 degrees or less, which is coated on the outer periphery of the core metal.
Use 2.0% or less of silicone rubber and have a thickness around it.
Since the fluororesin sleeve of 0.1 mm or less is coated, the thermal contraction of the silicone rubber can be reduced, and the silicone rubber is less susceptible to thermal expansion and contraction. The adhesiveness of the fluororesin sleeve is improved, and wrinkles generated in the fluororesin sleeve can be eliminated.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. In FIG. 1, 1 is a pressure roller, and the pressure roller 1 has a core metal 2 covered with an elastic layer 3
Further, the outer circumference thereof is covered with a fluororesin sleeve 4. In the present invention, the elastic layer is made of silicone rubber having a heat shrinkage of 2.0% or less.

In the present invention, the rubber hardness of the elastic layer 3 made of silicone rubber is not particularly limited as long as it is 30 degrees or less according to JIS A (JIS K6301), but silicone rubber having a hardness of 20 degrees or less is generally selected. Since rubber has a low stress and tends to have wrinkles, it is preferable to use rubber having a low hardness of 20 degrees or less. As the polyorganosiloxane containing a vinyl group as the base, methylvinylpolysiloxane is generally used, but methylphenylvinylpolysiloxane or the like can also be used.

In the present invention, the formulation of the filler for the elastic layer 3 is particularly important. Generally, silicone rubber is
Reinforcing fillers and extender fillers have been added to the polyorganosiloxane of S. Wet silica and dry silica (fumed silica) are generally used as the reinforcing filler. The wet silica referred to here is a reinforcing silica made of silicon oxide (SiO ₂ ), and as a manufacturing method, a direct method of directly decomposing sodium silicate with sulfuric acid or a method of reacting sodium silicate with a salt There are various methods such as an indirect method in which an acid salt is generated and then decomposed with sulfuric acid or carbon dioxide. Typical wet silicas are NipsilVN3 (product name of Nippon Silica Industry Co., Ltd.), Carplex CS-5 (product name of Shionogi Pharmaceutical Co., Ltd.), Starsil S (product name of Kamijima Chemical Co., Ltd.), Tokusil US (Tokuyama Co., Ltd. product name), Shilton R-2 (Misawa Chemical Co., Ltd. product name), Hisil 223 (PPG (US) product name), Ultras
il VN3 (trade name of Degussa (Germany)), Vulkasil S
(Trade name manufactured by Bayer (Germany)) is exemplified, and grades having an average particle size of 30 μm or less, preferably 5 μm or less are used.

Dry silica is composed of silicon dioxide produced by a thermal decomposition method of silicon halide, a thermal oxidation of silica sand, an air oxidation method of vaporized SiO ₂ or a thermal decomposition method of an organic silicon compound. Resilient silica, Aerosil 20
0 and Aerosil R 972 (product name of Nippon Aerosil Co., Ltd.), Cab-O-Sil MS-5 (product name of Cabot (US)),
For example, Leoroseal QS 102 (trade name of Tokuyama Co., Ltd.) is exemplified. In the present invention, if necessary, wet silica and dry silica may be appropriately used in combination, and further,
For the purpose of preventing secondary bonds due to the activity of the silica surface,
Wetting agents (wetting agents) may be added, and examples of these wetting agents include silicone resins, alkoxysilanes and siloxanes, hydroxysilanes and siloxanes, silazanes, organic acid esters, and polyhydric alcohols. It

In the present invention, it is important to add a filler composed of a metal oxide to the silicone rubber in addition to these reinforcing fillers in an amount of 5 to 45 parts by weight, preferably 15 to 35 parts by weight. As the metal oxide, Celite 270,281,501,503,5
05,535,545,560,577, FC, SSC, Super Floss, Snow Floss
(These are product names of Johns-Manville (USA)) and radio lights # 100, # 200, # 300, # 500, # 500-S, # 600, # 700, # 80
0, # 800 ー S, # 900, F, SPF, Fineflow F, Fineflow
Diatomaceous earth (silicon oxide) such as B (above, trade name of Showa Chemical Industry Co., Ltd.), Crystallite AA, VX-S, VX-S-2, V
X-SR (Tatsumori Co., Ltd. product name) and Min-U-Sil 5,1
Quartz powder (silicon oxide) such as 0,15,30 (above, product name of US Silica (US)), R-310, A-110, A-SP (above, product name of Sakai Chemical Industry Co., Ltd.) Titanium oxide, zinc flower 1
Oxide, such as No. (Sakai Chemical Industry Co., Ltd. product name), Bayferrox 130 M (Bayer company (Germany) product name)
Such as iron trioxide (Bengara), OBR-20 (trade name of Nippon Benji Kogyo Co., Ltd.), triiron tetroxide (iron black), chromium oxide G 5, G 7, green S (above, Nippon Kagaku Kogyo) Chromium oxide (such as the product name manufactured by Co., Ltd.), AL-45, AL-43M, AL-30, AL-
Aluminum oxide (alumina) such as 43PC (above, trade name manufactured by Showa Denko KK) is exemplified, and in the present invention, at least one filler made of these metal oxides is used.
It is necessary to add more than one kind to the silicone rubber.

[0025] Further, the extended fillers other than the fillers made of these metal oxides are, for example, novaculite (silica sandstone), zirconium silicate, clay (aluminum silicate), talc (hydrated magnesium silicate), wollastonite. (Calcium metasilicate), aluminum sulfate,
Barium sulfate, lithopone, molybdenum disulfide, mica (mica powder), graphite and the like may be used at appropriate times or may be used in combination with a filler made of a metal oxide.

Further, in LBP, negatively charged toner is generally used, and since PFA or silicone rubber used for the pressure roller is a negatively charged substance, electrostatic offset is apt to occur, and in order to avoid this problem, an elastic body is used. Layer 3
May be imparted with conductivity. In the present invention,
By adding at least one conductivity-imparting agent as a filler for silicone rubber, the volume resistivity can be reduced to 10 ¹⁰
Ω · cm or less may be used, and as these conductivity-imparting agents, acetylene black such as Denka Black (trade name of Denki Kagaku Kogyo Co., Ltd.), Toka Black # 5500, # 4500
Conductive carbon black such as (trade name of Tokai Carbon Co., Ltd.) and Ketjen Black EC (trade name of AKZO (Netherlands)), metal powder of graphite, silver, copper, nickel, etc., conductive zinc flower NO.1 , NO.2 (product name of Honjo Chemical Co., Ltd.) and 23-K (product name of Shiramizu Chemical Co., Ltd.)
Conductive zinc white such as, conductive barium sulfate such as Pastran 4110 (trade name of Mitsui Kinzoku Co., Ltd.), conductive titanium oxide such as W-1 (trade name of Mitsubishi Materials Co., Ltd.),
Antistatic calcium carbonate such as EC-1, EC-5 (trade name of Maruo Calcium Co., Ltd.) and carbon fiber are exemplified, but carbon black such as acetylene black or Ketjen black is generally used. .

In the present invention, it goes without saying that a heat-resistant agent such as cerium oxide may be added. Further, usually, the pressure roller made of silicone rubber is often supplied with red iron oxide, and in this case, red iron oxide is generally used as a colorant. As the type of red iron oxide mentioned above, the iron oxide red iron oxide specified in SRIS 1108 (Japan Rubber Association Standard) can be applied, and when it is necessary to pay attention to the orientation in the rubber during processing, Biferrox 130 A spherical grade having an average particle size of 0.3 μm or less, such as M (trade name of Bayer (Germany)), may be added to the silicone rubber in an amount of about 0.2 to 2% by weight. Recently, in consideration of dispersibility and scattering, CP-2
In many cases, 0.3 to 4% by weight of a silicone masterbatch having a content of about 50% such as 1 (trade name of Toray Dow Corning Silicone Co., Ltd.) is added.

As the vulcanizing agent in the present invention, in the case of a millable type silicone rubber, an ordinary organic peroxide for silicone rubber can be used, such as benzoyl peroxide, bis 2,4-dichlorobenzoyl peroxide, dioctane. Mill Peroxide, Di-tert-Butyl Peroxide, Tertiary Butyl Perbenzoate, Paramonochloro Benzoyl Peroxide, 2,5-Dimethyl-2,5-Di (tert-Butyl Peroxy) -Hexane, Tertiary Butyl Cumyl Peroxide, Tertiary Butyl peroxy-2-ethyl hexanoate, tertiary butyl peroxy isopropyl carbonate, 1,3-bis (tertiary butyl peroxy)
-3,3,5-Trimethylcyclohexane, tert-butylperoxy 3,5,5-hexanoate, etc. are exemplified, but dicumyl peroxide or 2,5-dimethyl
The use of 2,5- (tert-butylperoxy) -hexane is common.

However, in the present invention, it is not a millable type using the above-mentioned organic peroxide as a vulcanizing agent,
In the presence of a platinum catalyst, an addition type liquid silicone rubber composed of a vinyl group-containing polysiloxane and a hydropolysiloxane is more advantageous than a millable type from the viewpoint of easily obtaining a composition having a low hardness and the aforementioned linear shrinkage ratio. is there.

As the material of the fluororesin sleeve used in the present invention, PFA having a thickness of 0.1 mm or less is generally used.
If necessary, a conductivity-imparting agent such as the above-mentioned conductive carbon black may be added to this PFA to reduce the volume resistivity to 10
^The pressure roller may be formed by using a conductive PFA having a resistance of ¹³ Ω · cm or less and covering the outer circumference of the elastic layer.

In the present invention, the fluororesin sleeve 4 and the silicone rubber 3 which is an elastic layer are adhered to each other by a treatment liquid containing sodium metal and liquid ammonia or tetra H
Chemlock 607 (Road-made on the inner surface of the fluororesin sleeve 4 which has been subjected to inner surface treatment with a treatment liquid in which metallic sodium and naphthalene are dissolved in THF or ethylene glycol dimethyl ether such as (trade name of Junkosha Co., Ltd.)
Far East Incorporated product name)
Use by applying a silicone primer such as DY 39-067 (trade name of Toray Dow Corning Silicone Co., Ltd.) and vulcanizing it with the elastic layer 3 made of silicone rubber. Can go crazy.

The adhesion between the core metal 2 and the elastic layer 3 can be dealt with by using a silicone-based primer such as Primer No. 16 (trade name of Shin-Etsu Chemical Co., Ltd.), At this time, the metal core metal 2 is used by activating the surface with sandplast or the like in advance, degreasing it with methylene chloride, etc., then applying a primer, and if necessary, firing at 130 ° C. for about 30 minutes. .

[0033]

EXAMPLES Next, examples of the pressure roller 1 according to the present invention will be shown below, but the present invention is not limited thereto.
The hardness and impact resilience measured by the JIS A hardness meter, which is the physical property value of the silicone rubber in the examples and comparative examples, are JIS K 63.
01, the specific gravity and the linear shrinkage are measured according to JIS C 2123, respectively.

[0034]

Example 1 A typical addition type liquid silicone rubber
DY35-681A / B (trade name of Toray Dow Corning Silicone Co., Ltd.) A liquid 10kg, Hobart mixer,
As diatomaceous earth, 0.5 Kg of Radiolite F (trade name of Showa Kagaku Kogyo Co., Ltd.), which had been previously heated at 130 ° C. for 2 hours to remove water, was added and mixed for 2 hours. Next, this composition was placed in a bale can having a capacity of 20 liters, and then defoamed in a vacuum chamber for 16 hours to prepare solution A used in Example 1. Radio light to 10 kg of B solution of DY35-681 by the same procedure.
0.5 kg of F 2 was added to prepare solution B used in Example 1.

Next, 100 pieces of metal shafts having an outer diameter of 10 mm coated with an adhesive in advance and 100 pieces of PFA sleeves having an inner diameter of 25 mm and a wall thickness of 50 μm coated with an adhesive in advance were prepared, and these metal shafts were used as side molds. After holding it, insert it into the PFA sleeve and chuck both ends, then 26mm ID, 310mm length
It was mounted together with the shaft at room temperature in the cylindrical mold. next,
A bale can containing the above composition was set on a bale pump, and liquid A and B were mixed with a static mixer, and liquid silicone rubber was filled from a side rubber injection port.

Next, the mold was heated in a hot air oven at 130 ° C. for 1 hour for vulcanization, and then the pressure roller was detached from the mold. Subsequently, 100 pressure rollers were formed by the same procedure, and the pressure rollers were heated in a constant temperature bath at 200 ° C for 4 hours and then taken out from the constant temperature bath to determine the occurrence rate of wrinkles of the fluororesin on the surface layer. I asked. It was found that the composition of Example 1 had an occurrence rate of 2 out of 100 wrinkles, and the wrinkles generated in the 2 wrinkles were extremely small, and wrinkles were hardly generated in Example 1.

[0037]

【table 1 】

[0038]

[Examples 2 to 13] 100 pressure rollers similar to those in Example 1 were used except that the composition having the composition shown in Table 1 was used, and the wrinkle occurrence rate of the fluororesin on the surface layer was determined. The quartz powder used in Examples 4 to 7 was Crystallite VX-S (trade name of Tatsumori Co., Ltd.), and the alumina used in Examples 8 to 10 was alumina.
AL-43PC (Product name manufactured by Showa Denko KK) was used in Example 11-
Zinc oxide No. 1 (trade name, manufactured by Sakai Chemical Industry Co., Ltd.) was used as the zinc oxide used in 13, and both were heated at 130 ° C. for 2 hours before use to remove water content, as in Example 1. Used from.

As can be seen from the results in Table 1, Examples 2 to 13
Then, it was found that wrinkles hardly occurred. Examples 1 to 13
All the compositions have a rebound resilience of 56% or more, and by setting the linear shrinkage of the silicone rubber to 2.0% or less, wrinkles will not occur if the specific gravity is 1.20 or less or 1.20 or more, as long as the rebound is high. I found that there was no problem above. In Example 13, the rubber layer was slightly foamed.

[0040]

[Comparative Examples 1 to 3] 100 pressure rollers were prepared in the same manner as in Examples 1 to 13 except that the formulations shown in Table 1 were used, and the wrinkle occurrence rate of the surface fluororesin was determined. In Comparative Examples 1 to 3, the occurrence rate of wrinkles was high, and the wrinkle size was large at 30 mm or more. From the results shown in Table 1, it was found that wrinkles were generated at a linear shrinkage of 2.1% or more even with a high impact resilience.

[0041]

Examples 14 to 21 X-34-290-A / B (trade name: volume resistivity 1 × 10 ⁴ Ω · cm manufactured by Shin-Etsu Chemical Co., Ltd.), which is a typical conductive addition type liquid silicone rubber, was used. 100 pressure rollers were prepared in the same manner as in Examples 1 to 14 except that the composition shown in Table 2 was used, and the wrinkle occurrence rate of the fluororesin on the surface layer was determined.

[0042]

[Table 2]

From the results shown in Table 2, by setting the linear shrinkage of the silicone rubber to 2.0% or less, wrinkles hardly enter the surface PFA layer regardless of the specific gravity and impact resilience of the composition, which is a practical problem. It turns out that there is no.

[0044]

[Comparative Examples 4 to 11] 100 pressure rollers were prepared in the same manner as in Examples 1 to 13 except that the formulations shown in Table 2 were used, and the wrinkle occurrence rate of the fluororesin on the surface layer was determined. In Comparative Examples 4 to 11, the wrinkle occurrence rate is high, and in particular, as in Comparative Examples 10 to 11, the specific gravity is 1.20 to 1.40 and the impact resilience is 20 to 55%. It turned out to occur.

[0045]

In the pressure roller according to the present invention, since the silicone rubber having a linear shrinkage ratio of 2.0% or less is used in the silicone rubber layer, the heat shrinkage of the silicone rubber, which is the elastic layer, can be reduced. Since the silicone rubber is less susceptible to thermal expansion and contraction, the adhesiveness of the fluororesin sleeve coated on the outer periphery is improved, wrinkles occurring on the fluororesin sleeve can be avoided, and the pressure roller can be manufactured efficiently. Is something that can be done.

[Brief description of drawings]

FIG. 1 is a sectional view of a pressure roller of the present invention.

[Explanation of symbols]

 1 Pressure roller 2 Core metal 3 Silicone rubber layer 4 Fluororesin sleeve

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[Procedure amendment]

[Submission date] July 16, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 2

[Correction method] Change

[Correction contents]

2. A silicone rubber is a linear shrinkage of 2.0% or less, and a pressure roller according to claim 1, wherein the modulus of repulsion elasticity is characterized Oh Rukoto in 56% or more.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction contents]

JP-A-7-334024 can be cited as a conventional example of a measure for the wrinkle generation of the fluororesin. The above publication discloses that the elastic layer of the pressure roller has a specific gravity of 1.20 to 1.40 and a repulsion elastic modulus of 20 to 55%.
A pressure roller made of silicone rubber is disclosed. Toko filtrate is wrinkles even application of the composition of the defined specific gravity resilience modulus as in publication silicone rubber may occur. The above-mentioned publication points out that the above-mentioned wrinkles occur due to repeated use over a long period of time, and the cause thereof is repeated thermal expansion and thermal contraction.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display area // B29K 27:12 83:00 105: 24 503: 04 705: 00 B29L 31:32

Claims (6)

[Claims] 1. A pressure roller in which a fluorine resin sleeve having a thickness of 0.1 mm or less is coated on the outer periphery of a silicone rubber layer having a hardness of 30 degrees or less, which is coated on the outer periphery of a core metal, and the linear shrinkage rate is used as the silicone rubber layer. The pressure roller is characterized by using silicone rubber of 2.0% or less. 2. The pressure roller according to claim 1, wherein the silicone rubber has a linear shrinkage of 2.0% or less and a repulsion elasticity of 56% or more. 3. A silicone rubber with 5 to 45 weighting fillers.
The pressure roller according to claim 1 or 2, wherein the pressure roller is contained in a weight percentage. 4. The extender filler is a metal oxide, and diatomaceous earth (silicon oxide), quartz powder (silicon oxide), alumina (aluminum oxide), titanium oxide, zinc oxide (zinc oxide),
It is characterized by containing at least one compounding agent functioning as a filler selected from the group of metal oxides consisting of chromium oxide, red iron oxide (diiron trioxide) and iron black (triiron tetraoxide). The pressure roller according to claim 1, 2 or 3. 5. A pressure roller according to claim 1, wherein the silicone rubber is an addition type liquid silicone rubber. 6. A surface treatment of the inner surface of a fluororesin sleeve having a thickness of 0.1 mm or less with a treatment liquid prepared by dissolving sodium metal in liquid ammonia or a treatment liquid prepared by dissolving naphthalene and sodium metal in an organic solvent. After applying the adhesive treatment with an adhesive, and fixing both ends of this adhesive-treated fluororesin sleeve to the side mold that holds the core metal that has been subjected to the adhesive treatment with the adhesive in advance. While holding this in a cylindrical mold, inject silicone rubber with a linear shrinkage of 2.0% or less into the annular space between the cored bar and the sleeve, heat vulcanize it, and heat the fluororesin sleeve and silicone. A method for manufacturing a pressure roller, characterized by integrating with rubber.