JPH0753432B2 - Elastic roll - Google Patents

Description

The present invention relates to an elastic roll used as a fixing roll and a pressure roll of an electronic copying machine or the like.

[Conventional technology]

As an elastic roll used as a fixing roll or a pressure roll in a fixing device such as an electronic copying machine, a silicone resin elastic layer provided on a core metal on the roll is usually coated with a fluorine-based resin coating layer using an adhesive. What is formed is used.

Conventionally, as such an elastic roll, one in which a primer is applied on the inner surface of the fluororesin coating layer after etching treatment is adhered to the silicone rubber elastic layer using an adhesive composed of condensation curing type RTV silicone rubber. A known elastic roll is (JP-B-47-20747).

There is also known an elastic roll in which a silicone rubber elastic layer and a fluororesin coating layer are adhered to each other with an adhesive composed of a fluororesin-containing latex (JP-A-61-38957).

[Problems to be Solved by the Invention]

However, in those elastic rolls, since the layers constituting the rolls are made of different materials, the adhesive force obtained between the silicone rubber elastic layer and the fluororesin coating layer is unstable, and the durability of the adhesion is high. Has the drawback of being low. Further, when a condensation-curable RTV silicone rubber is used as the adhesive, the curing speed on the surface of the silicone rubber, which is the adhesive layer, is high, so that the thickness of the obtained adhesive layer becomes uneven. Since the smoothness of the surface is lowered, there is a drawback that the accuracy of the diameter of the obtained roll is lowered.

Therefore, an object of the present invention is that the adhesion between the silicone rubber elastic layer and the fluororesin coating layer is stable and has high durability,
Another object is to provide an elastic roll having a high precision in roll diameter.

[Means for Solving the Problems]

MEANS TO SOLVE THE PROBLEM This invention solves this subject, (a) The silicone rubber elastic layer provided on the roll-shaped core metal, (b) The adhesive layer provided on the said (a) layer, and (b) c) In the elastic roll having the fluorine-based resin coating layer provided on the layer (b), the adhesive layer (b) includes (i) an alkenyl group-containing diorganopolysiloxane, ( (B) Organohydrogenpolysiloxane, (c) platinum-based catalyst, and (d) two or more functional groups selected from the group consisting of epoxy groups, alkoxy groups, vinyl groups, and SiH groups in one molecule An elastic roll comprising a cured product of an addition-curable silicone rubber composition containing an organosilicon compound.

Silicone rubber elastic layer of (a) The silicone rubber used in the silicone rubber elastic layer constituting the elastic roll of the present invention is not particularly limited, and any known silicone rubber can be used. A typical example of such a silicone rubber is a cured product of a silicone rubber composition in which a filler and other additives are blended with diorganopolysiloxane as needed.

Examples of the diorganopolysiloxane used include, for example, dimethylpolysiloxane, methylvinylpolysiloxane, methylphenylpolysiloxane, and 3,3,3-trifluoropropylmethylpolysiloxane, and various siloxy units and siloxanes constituting them. Various copolymers of units can be mentioned.

As the filler, for example, famed silica, precipitated silica, hydrophobic silica, carbon black, titanium dioxide,
Ferric oxide, aluminum oxide, zinc oxide, quartz powder,
Examples thereof include diatomaceous earth, calcium silicate, talc, bentonite, asbestos, glass fiber, and organic fiber, and one or more of these may be blended. Further, as the additive other than the filler, one kind or two or more kinds among various kinds can be blended.

The type of curing of the silicone rubber composition is not limited at all,
Therefore, any of an organic peroxide curing type, an addition reaction curing type utilizing a hydrosilylation reaction of a Si-H bond and an aliphatic unsaturated bond with a platinum group metal-based catalyst, and various condensation curing types may be used.

Among such silicone rubbers, the organic peroxide curable type and the addition reaction curable type are particularly preferable in the present invention. However, when a condensation-curing type silicone rubber is used, care must be taken because the adhesive layer (b) may cause curing failure due to catalyst poison depending on the type of condensation catalyst used.

The silicone rubber elastic layer is formed on the core metal according to the usual method by molding the unvulcanized silicone rubber containing the curing agent into the required shape on the core metal that has been precoated with a primer if necessary. Then, after curing, it can be performed by polishing to a predetermined external dimension. Typical primers used include, for example, Shin-Etsu Chemical Co., Ltd. primer No. 16, N, which is usually used for adhesion of silicone rubber and metal.
o.18B (brand name) and the like. In addition, the molding of the unvulcanized silicone rubber on the core metal can be performed by a molding method such as pressure molding, injection molding, extrusion molding, or casting method.

Further, as the material of the core metal, a metal such as aluminum or iron or an alloy thereof is usually used.

Adhesive Layer of (b) The addition-curable silicone rubber composition used as an adhesive is (a) an alkenyl group-containing diorganopolysiloxane, (b) an organohydrogenpolysiloxane, and (c) a platinum-based curing agent. The catalyst and (d) the adhesiveness-imparting agent are essential components, and if necessary, the fillers and additives used in the silicone rubber elastic layer (a) may be appropriately blended.

Representative and preferred examples of the addition-curable silicone rubber composition used in the present invention will be specifically described below.

(A) Diorganopolysiloxane containing alkenyl group: This component preferably contains at least two alkenyl groups bonded to silicon atoms in one molecule. Examples of such an alkenyl group include a vinyl group and an allyl group, and a vinyl group is preferable. In addition, other organic groups bonded to the silicon atom have 10 carbon atoms.
The following monovalent hydrocarbon groups are preferable, for example, a methyl group,
Alkyl group such as ethyl group, propyl group, butyl group, aryl group such as phenyl group, tolyl group, chloromethyl group, 3,
Examples thereof include hydrocarbon groups in which some or all of hydrogen atoms such as 3,3-trifluoropropyl group are substituted with halogen atoms and the like, and among them, a methyl group and a phenyl group are preferable.
A straight-chain diorganopolysiloxane containing these alkenyl groups and monovalent hydrocarbon groups having 10 or less carbon atoms is preferable. Further, the alkenyl group may be present at any position in the molecular chain of the diorganopolysiloxane or at both ends of the molecular chain, and the content thereof is preferably 0.05 to 10 mol% in all the organic groups.

(B) Organohydrogenpolysiloxane: Since the organohydrogenpolysiloxane is a cross-linking agent that cures the composition by addition reaction with the alkenyl group in the diorganopolysiloxane of (a) above, at least 2 per molecule. It is necessary to have 4 SiH groups.
The molecular structure may be linear, cyclic or branched. The amount of the organohydrogenpolysiloxane used is such that the molar ratio [Si—H group] / [alkenyl group] of the Si—H group contained therein and the alkenyl group in the diorganopolysiloxane of (a) is 0.5 to 5 The amount is preferably in the range of.

(C) Platinum-based catalyst: This component may be a known one, and examples thereof include chloroplatinic acid, alcohol-modified chloroplatinic acid, and a complex of chloroplatinic acid and an olefin. The amount used is usually (a) above.
About 1 to 100 ppm is sufficient for the components.

(D) Adhesiveness imparting agent: As this component, a silicon compound containing a functional group that imparts adhesiveness is preferable. Examples of such a functional group include an epoxy group, an alkoxy group, a vinyl group, a SiH group and the like, and a group containing two or more of these functional groups in one molecule is particularly preferable. Further, as the silicon compound containing such a functional group, for example, And so on. The amount of the adhesion-imparting agent is usually 0.1 per 100 parts by weight of the diorganopolysiloxane of (a).
However, when the adhesiveness-imparting agent contains a Si—H bond as a functional group in the molecule, the molar ratio to the alkenyl group in the alkenyl group-containing diorganopolysiloxane is 5 to 5 parts by weight. Ratio: [SiH group] / [alkenyl group]
The amount is preferably in the range of 0.5 to 10.

The filler and the conversion agent may be known ones, for example, those exemplified in the silicone rubber elastic layer of (a), etc., and the compounding amount thereof is usually 100 parts by weight of the diorganopolysiloxane of the above-mentioned component (a). 5 to 100 parts by weight.

The hardness (JIS K 6301) of the addition-curable silicone rubber composition used for the adhesive layer after curing is preferably equal to or higher than the hardness of the silicone rubber elastic layer described above in order to obtain sufficient adhesion durability. . For example, the hardness of the silicone rubber elastic layer depends on the application or specifications, but
Since it is about 20-70, the hardness of the adhesive layer after curing is 30-
A range of 80 is preferred. The hardness can be adjusted by the structure of the (b) organohydrogenpolysiloxane, which is a crosslinking agent, or the amount of the filler added.

Examples of the method of applying the addition-curable silicone rubber composition used for the adhesive layer on the silicone rubber elastic layer include, for example, diluting the addition-curable silicone rubber composition with an organic solvent and spray-coating or dipping the solution. There is a method of applying. Examples of the organic solvent include toluene, xylene, 1,1,1-trichloroethane, tetrachloroethylene and the like. The thickness of the formed adhesive layer is preferably 0.1 to 0.3 mm, because if the thickness is too thin, the adhesive strength will decrease, and if it is too thick, the layer thickness may lack uniformity.

When a uniform adhesive layer is formed by spray coating, it is preferable to preheat the silicone rubber elastic layer on the core metal to 50 to 80 ° C. As a result, the solvent in the adhesive solution quickly volatilizes on the surface of the silicone rubber elastic layer, and the addition-curable silicone rubber composition is likely to become fine particles, and the heat of vaporization generated during solvent volatilization causes a decrease in adhesive strength. The effect of preventing the adsorption of water on the surface of the elastic layer of silicone rubber is also produced. When an addition-curable silicone rubber composition having a high viscosity is used, it is preferable to buff the surface of the layer after applying the adhesive in order to improve the surface smoothness.

(C) Fluorine-based resin coating layer In order to form the fluorine-based resin coating layer, it is necessary to use a fluorine-based resin tube in terms of strength and uniformity of the coating layer. Among them, the heat shrinkable type is particularly preferable in terms of workability. Further, the material is preferably heat resistant, and examples of the fluororesin tube of such a material include polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoroalkyl. Examples thereof include vinyl ether copolymer (PFA).

The surface of the adhesive layer is coated with a fluororesin tube made of such a material, but in order to obtain sufficient adhesive strength,
It is preferable that the inner surface of the fluororesin tube is previously etched. In addition, a commercially available fluororesin tube whose inner surface is etched with sodium-naphthalene or the like may be used.

The thickness of the fluororesin tube is preferably 0.05 to 1.0 mm, and it is desirable to properly use the fluororesin tube depending on the type of the fluororesin tube, the application of the elastic roll described later, and the like.

After coating the surface of the adhesive layer with a fluororesin tube, the fluororesin tube is heat-shrinked by a heating means such as a hot air gun or a dryer, and at the same time air is removed to give a fluororesin coating layer. To form. In order to obtain an elastic roll having a smoother surface, it is advisable to perform pressure bonding with a pressure bonding roll from above the fluororesin tube during the above process.

Finally, heat treatment is performed to cure the adhesive. In the present invention, it is preferable to perform heat treatment using a dryer at 150 ° C. for 30 to 60 minutes.

Use The elastic roll thus obtained can be used in a fixing device such as an electronic copying machine. In this case, depending on the combination of the thickness of the silicone rubber elastic layer and the thickness of the fluororesin tube, it can be used for both the fixing roll and the pressure roll.

For example, when used in a fixing roll, the thickness of the silicone rubber elastic layer is usually 0.1 to 0.5 mm, and the thickness of the fluororesin tube is preferably 0.03 to 0.1 mm.When used in a pressure roll, The thickness of the silicone rubber elastic layer is 5-10m
m, and the thickness of the fluororesin tube is preferably 0.05 to 1.0 mm.

〔Example〕

A silicone primer (external diameter 84 mmφ, length 350 mm) serving as the core of the roll was coated with a silicone-based primer (Shin-Etsu Chemical Co., Ltd., trade name No. 16). In addition, silicone rubber compound (Shin-Etsu Chemical Co., Ltd., trade name
KE-7010u) 100 parts by weight and an organic peroxide as a vulcanizing agent: 2,5
A mixture of 0.5 part by weight of -dimethyl-2,5-di (tert-butylperoxy) hexane was heat-molded by press vulcanization using a mold. After that, the silicone rubber elastic layer was formed by polishing to an outer diameter of 100 mmφ with a polishing machine. The rubber strength of this silicone rubber elastic layer was 50.

On the other hand, the addition-curable silicone rubber composition used for the adhesive layer was prepared as follows.

100 parts by weight of diorganopolysiloxane compound (Shin-Etsu Chemical Co., Ltd., trade name KE-164u) Methylhydrogenpolysiloxane of the following formula 0.1 parts by weight of chloroplatinic acid in isopropanol (Pt concentration 1% by weight) The above was uniformly dissolved using 800 parts by weight of tetrachloroethylene as a solvent and mixed to prepare an addition-curable silicone rubber composition for use as an adhesive layer.

This composition was applied to the surface of the silicone rubber elastic layer preheated to 70 ° C. using a spray gun while rotating a roll to form an adhesive layer. Then, it was left to air-dry to volatilize the solvent. When the thickness of this adhesive layer was measured by a laser length measuring device, it was about 0.2 mm.

The molar ratio of SiH group and vinyl group in the addition-curable silicone rubber composition prepared here: [SiH group] / [vinyl group] was 4.0, and the rubber hardness after curing was the same separately. It was 60 when the cured sheet was formed from the composition under the same conditions and measured.

On the other hand, heat-shrinkable fluororesin tube (ZEUS FE
The inner surface of the P resin, which had an inner diameter of 105 mmφ and a thickness of 0.25 mm before shrinkage) was subjected to etching treatment with a sodium-naphthalene tetrahydrofuran solution, and the surface of the adhesive layer was coated with this fluororesin tube. Next, the fluororesin tube was heat-shrinked with a hot air gun, and pressure was applied by a pressure roll to smooth the surface of the elastic roll after coating. Finally, in order to cure the adhesive layer, the elastic roll was left in a dryer at 150 ° C./30 minutes.
After cooling, when the outer diameter of the obtained elastic roll was measured using a laser length measuring machine, it was 100.9 to 101.0 mmφ,
The eccentricity was measured to be 0.1 mm or less. The eccentricity was measured by reading the swing width of the dial gauge of the laser length measuring machine when the outer diameter of the elastic roll was measured by rotating the roll while supporting it with a bearing.

When the obtained elastic roll was mounted on a copying machine as a pressure roll and used, the paper feed was good. further,
It was used for a long time until the abrasion of the fluorine-based resin coating layer due to the edge of the paper exceeded 0.1 mm and offset occurred, but no peeling of the adhesive layer occurred.

〔The invention's effect〕

Since the elastic roll of the present invention uses the addition-curable silicone rubber composition as the adhesive layer, the adhesion between the silicone elastic layer and the fluororesin coating layer is stable and highly durable, and the roll diameter accuracy is high. Is high.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Bibliographic references Kaihei 2-119662 (JP, U) Toshiba Silicone Co., Ltd. "Adhesive liquid silicone rubber (thermosetting, one-component type) TSE 32XX series" catalog (September 1985) Mon) 1-2 pages Toray Dow Corning Silicone Co., Ltd. “Electronics Silicone” Catalog (June 1990) pages 8-9

Claims (2)

[Claims] 1. An (a) silicone rubber elastic layer provided on a roll-shaped core metal, (b) an adhesive layer provided on the (a) layer, and (c) an (b) layer. In the elastic roll having the fluorine-based resin coating layer provided in (b), the adhesive layer (b) has (i) an alkenyl group-containing diorganopolysiloxane, (b) an organohydrogenpolysiloxane, (C) Platinum catalyst, and (D) Epoxy group, alkoxy group, vinyl group, and SiH
An elastic roll comprising a cured product of an addition-curable silicone rubber composition containing an organosilicon compound having, in one molecule, two or more functional groups selected from the group consisting of groups. 2. The JIS K 6301 adhesive layer of (b) above.
The hardness of the silicone rubber elastic layer of (a) is equal to or less than the hardness of the silicone rubber elastic layer measured according to the same standard.
The elastic roll according to claim 1, which is higher than 10.