JPS63202450A - Elastic body, surface of which has fluoroplastic layer, and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention generally provides a surface with mold releasability, lubricity, wear resistance,
The present invention relates to elastic bodies used in various applications requiring oil resistance, weather resistance, etc., and methods for manufacturing the same. More specifically, the present invention applies to various elastic rollers and elastic plates used in various office equipment such as printing machines, printers, and copying machines, as well as elastic members in other fields, such as oil seals, backings, and gaskets used in automobiles. The present invention relates to elastic bodies such as tubes, hoses, etc., sealing materials used in architecture and civil engineering, and various types of tubes and hoses in the chemical and food industries, and their manufacturing methods.

Conventionally, elastic bodies used in the various fields mentioned above include:
Silicone rubber and fluorine rubber are common. In addition, in recent years, mold releasability, lubricity, heat resistance, abrasion resistance, oil resistance or weather resistance,
Furthermore, attention has been focused on fluororesin, which is well known for its excellent properties such as electrical insulation, water repellency, and non-toxicity, and elastic bodies with fluororesin formed on the surface are being used, and various researches are being conducted. Experiments have been carried out, but nothing that is comprehensively satisfactory has yet been found.

That is, for example, silicone rubber has excellent rebound properties, mold releasability, durability, etc., but is inferior in lubricity, abrasion resistance, and oil resistance. Although fluororubber has provided an elastic body with heat resistance, oil resistance, weather resistance, electrical insulation properties, etc., it is not satisfactory in other properties such as mold releasability, lubricity, abrasion resistance, and repulsion. It's expensive. In addition, an elastic body in which a fluororesin is fired on the surface of fluororesin rubber has been proposed, but the manufacturing cost is high, and when the fluororesin layer is fired, the fluororesin deteriorates due to the firing temperature, making it difficult to achieve the desired rubber elasticity. The problem was that it was not possible to obtain

There is also a method of forming latex with fluororesin dispersed on the rubber surface and making the fluororesin stand out on the surface to form an elastic body having the fluororesin on the surface, but the layer thickness of the fluororesin obtained by this method is It was about 1 to 3 liters at most, and was not particularly satisfactory in terms of strength.

Furthermore, there is also a method of obtaining an elastic body having a fluororesin layer on the surface by once forming a film with a fluororesin and closely bonding the film to the surface of the elastic body. however,
In order to bond a fluororesin that has been fired into a film to an elastic body, the surface of the fluororesin that is to be bonded to the elastic body is treated with a treatment agent such as a sodium ammonia solution to make it easier to bond, and then an adhesive is used. It must be glued to an elastic body.

Therefore, although this is true in the case of a flat elastic body, when producing a cylindrical or other special shaped elastic body, it is difficult to maintain the fluororesin film in such a shape and adhere it uniformly to the elastic body. Met.

Furthermore, a film is first formed with a fluororesin, the adhesive surface of the film is treated in the same manner as above and an adhesive is applied, and unvulcanized rubber is then placed in contact with the adhesive. There is also a method of obtaining an elastic body having a fluororesin on the surface by vulcanizing it. However, this method has a number of manufacturing problems, such as the complexity of the process for obtaining adhesion between the fluororesin layer and the elastic layer, and the difficulty in maintaining the shape during adhesion.

Additionally, attempts have been made to coat the surface of fluororubber or silicone rubber with fluororesin powder or dispersion, and then sinter it using a dielectric heating method so as not to deteriorate the physical properties of the rubber, thereby obtaining an elastic body with fluororesin on the surface. ing. However, even with this method, the rubber temperature is about 250℃.
When heated to a certain degree and has a large coefficient of thermal expansion, the shape changes unstablely during firing, and when the first elastic layer is thick, undesirable defects such as cracks and unevenness occur in the fluororesin layer formed on the surface layer. . More specifically, a good quality fluororesin layer can be obtained using this method if the thickness of the elastic layer is at most 5.
．． Even if the thickness is up to about 0mm, if you want a particularly high quality one, the thickness of the elastic layer should be at most 1.5mm.
There was a certain level of convergence, and beyond that, the desired result could not be obtained.

An object of the present invention is to provide an elastic body that has a high-quality fluororesin layer on its surface and sufficiently maintains its properties as an elastic body, and a method for producing the same.

Another object of the present invention is to provide an elastic body having a fluororesin layer on its surface, which has an elastic layer having a sufficient thickness of about 1.5 mm or more, and a method for manufacturing the same.

The above aspects are achieved by the elastic body and the method for manufacturing the same according to the present invention. In summary, the present invention includes a fluororesin layer forming a surface layer, a first elastic layer provided as a lower layer of the fluororesin layer, and a second elastic layer disposed as a lower layer of the first elastic layer. The elastic body layer is made of fluorine rubber or silicone rubber, and the fluorine resin is PTFE resin (tetrafluoroethylene resin). , a fluororesin such as PFA resin (copolymer of tetrafluoroethylene resin/perfluoroalkoxyethylene resin) is suitable.

The above-mentioned elastic body can take various shapes such as a flat plate shape or a roll shape, but in any case, a fluororesin layer is formed on the surface of the first elastic body to form a multilayer body, and then the multilayer body is used to form a multilayer body. It is suitably manufactured by coating the surface of the second elastic body.

Difference j Next, the elastic body and manufacturing method according to the present invention will be explained in more detail with reference to the drawings.

Referring to FIG. 1, one embodiment of the elastic body according to the present invention is illustrated. According to this embodiment, a plate-shaped elastic body is illustrated. In this embodiment, one elastic body is: A fluororesin layer 1 forming a surface layer, a first elastic layer 2 provided as a lower layer of the fluororesin layer 1, and a second elastic layer disposed as a lower layer of the first elastic layer 2. Preferably, a primer layer 3 is disposed between the first elastic layer 2 and the second elastic layer 4.

The fluororesin layer 1 is made of a fluororesin such as PTFE resin (tetrafluoroethylene resin) or PFA resin (a copolymer of tetrafluoroethylene resin or perfluoroalkoxyethylene resin), and the layer thickness is 5 pm to 50 ILm. Preferably IOpm
~30 ILm, more preferably 15 pLm ~ 25 μm
It is said that The first elastic layer 2 and the second elastic layer 4 are made of silicone rubber or fluororubber. The first elastic layer 2 is thin, with a layer thickness of 0.2 mm to 5.0 mm, preferably 0.2 mm to 3.0 mm, and more preferably 0.2 mm.
#1.5mm, and the second elastic layer 4 is the first elastic layer 2.
The layer thickness is 0.5 mm or more, preferably 1 mm.
．． 0mm or more, more preferably 3.0mm-10.0m
It is assumed that m. - For example, the fluororesin layer 1 has a thickness of 15I
The 4-fluoroethylene resin layer and the first elastic layer 2 of Lm have a thickness of 0.
．． The 5 mm thin silicone rubber layer and the second elastic layer are 5 mm thick silicone rubber layers.

Next, a method for manufacturing a flat elastic body having such a structure will be explained with reference to FIG. 2.

First, a dispersion of tetrafluoroethylene resin (a dispersion of fluororesin powder in water with a surfactant) la and a first elasticity made of thin silicone rubber vulcanized into a flat plate shape with a thickness of 0.5 mm are prepared. Prepare the body layer 2, and apply the dispersion 1a on the first elastic layer 2 to a thickness of 3 by any method.
Coat with 3ILm (step (a)).

The resultant product consisting of the dispersion 1a and the first elastic layer 2 thus formed is charged into a shape-retaining mold B made of stainless steel and fired by dielectric heating (step (b)).
As a result of this firing, the fluororesin dispersion has a layer thickness of 15IL.
The result is a 4-fluorochemically modified tyrene resin layer 1 of m.

In the above step (b), the coefficient of linear expansion of the shape-retaining YJ6 is 20 to 30% of that of silicone rubber, and therefore, by using such a shape-retaining mold 6, the thin silicone rubber layer 2 can be transformed into a 4-fluoroethylene resin layer. In the direction of the surface where 1 is formed,
In other words, thermal expansion in the horizontal direction is prevented. Furthermore,
Since the thin silicone rubber layer 2 is held in a concave shape within the shape-retaining mold 6, distortion caused by heating is contained within the silicone rubber layer 2. Furthermore, thin silicone rubber layer 2
Since the thickness of the silicone rubber layer 2 is less than 0.5 mmL, the absolute amount of thermal expansion of the thin silicone rubber layer 2 in the direction perpendicular to the direction of the surface on which the 4-fluoro ethylene resin layer is formed is small. In the firing process for forming layer l, the 4-fluoroethylene resin layer l of the thin silicone rubber layer 2
The shape stability on the forming surface is very high, and it is possible to form a high-quality 4-fluoroethylene resin layer 1 without defects such as cracks and waviness.According to the research of the present inventors, a thin silicone rubber layer It has been found that the practical limit for the thickness of No. 2 is approximately 5 mm, and that if the thickness exceeds this, it is not possible to easily form a high quality tetrafluoroethylene resin layer.

Next, a commonly used primer 3 is applied to the side opposite to the fluororesin layer 1 of the multilayer body 5 preferably consisting of the first elastic layer 2 and the fluororesin layer 1 (step (d)), and then In a conventional manner, a thick silicone rubber layer 4 vulcanized and molded to a thickness of 5 mm is adhered and heat-bonded to the surface coated with the primer 3.

By the above manufacturing method, it is possible to obtain a thick elastic plate which has a high-quality fluororesin layer on its surface and which sufficiently maintains its properties as an elastic body.

Furthermore, as described above, it is also possible to use PFA powder instead of the tetrafluoroethylene resin dispersion 5 as the fluororesin, and to heat with an electric furnace instead of dielectric heating. Also, fluororubber can be used instead of silicone rubber as the elastic layer.

FIG. 3 shows an example of a roller-shaped elastic body according to the present invention. According to this embodiment, a fluororesin layer l, a first elastic Calendar 2,
A first layer of primer 3 and a second elastic layer 4 are laminated. The material and layer thickness of each layer are the same as those of the flat elastic body described in connection with FIG.

An embodiment of the method for manufacturing the roller-shaped elastic body will be described with reference to FIG. 4. First, a thin silicone rubber layer 2 with a thickness of 0.5 mm which is vulcanized into a tube shape is prepared, and a dispersion 1a of tetrafluoroethylene resin is applied to the surface of the silicone rubber layer 2 to a thickness of 33 tons. Coating (step (a)).

An inner shape holding cylinder 8 is inserted into the resultant product consisting of the dispersion 1a and the first elastic layer 2 thus formed, and the tubular thin silicone rubber layer 2 is fired by dielectric heating while maintaining its shape. (Step (b)), the fluororesin dispersion was formed into a 4-layer film with a layer thickness of 15 #Lm by the baking.
This becomes the fluoroethylene resin layer 1.

Next, the inner shape retaining cylinder 8 is removed, and the outer shape retaining cylinder 9 is applied to the outer peripheral surface of the multilayer elastic body 5 made of the first elastic body layer 2 and the tetrafluoroethylene resin layer 1 produced in step (b). The iron core 7 is placed at the 1st cylindrical shaft position (step (
c)).

After that, a primer 3 is applied to the surface of the iron core 7 and the inner surface of the tube-shaped thin silicone rubber layer 2 (step (d)).
), unvulcanized liquid silicone rubber is injected into the space between the iron core 7 coated with the primer and the tubular thin silicone rubber layer 2.

Next, vulcanization is performed in a usual manner to form a silicone rubber layer 4 (step (e)).

The above method provides a high quality fluororesin layer on the surface.

Moreover, it is possible to obtain a roller-shaped elastic body with a large thickness of the elastic portion, which sufficiently maintains the characteristics as an elastic body.

As is clear from the above description, the elastic body according to the present invention has the following characteristics:
A fluororesin layer forming a surface layer, and a first elastic layer provided as a lower layer of the fluororesin layer.

Since the structure includes a second elastic layer disposed as a lower layer of the first elastic layer, it has excellent mold releasability, lubricity, abrasion resistance, oil resistance, weather resistance, etc. An elastic body can be provided, and the elastic body can be formed by forming a fluororesin layer on the surface of a thin elastic body to form a multilayer body, and then combining the multilayer body with a thick elastic body. Therefore, it is possible to obtain a thick elastic body having a high-quality fluororesin layer on the surface and having desired hardness and elasticity.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of an elastic body according to the present invention. FIGS. 2A to 2E are explanatory diagrams illustrating the manufacturing process for manufacturing the elastic body shown in FIG. 1. FIG. 3 is a sectional view of another embodiment of the elastic body according to the present invention. FIGS. 4(&) to (e) are explanatory diagrams illustrating the manufacturing process for manufacturing the elastic body of FIG. 3. FIG. l: Fluororesin layer 2: First elastic layer 3 Nib rimer layer 4: Second elastic layer 7: Core metal 11 Figure 2 (() 1a~1==555==L-2↓ ↓ ('') 5 (zj play Eji ↓ (Town 5 (I = Nil 3 ↓ Figure 3 Figure 4 Copper Figure 4 ↓

Claims (1)

[Claims] 1) A fluororesin layer forming a surface layer, a first elastic layer provided as a lower layer of the fluororesin layer, and a first elastic layer disposed as a lower layer of the first elastic layer. 1. An elastic body having a fluororesin layer on its surface, characterized in that it has two elastic body layers. 2) The elastic body according to claim 1, wherein the first and second elastic body layers are formed of fluororubber or silicone rubber. 3) The thickness of the fluororesin layer is 5 μm to 50 μm, and the first
The elastic body according to claim 1 or 2, wherein the thickness of the elastic body layer is 0.2 mm to 5.0 mm, and the thickness of the second elastic body layer is 0.5 mm or more. 4) The elastic body according to claim 1, 2, or 3, wherein the elastic body has a flat plate shape. 5) Claim 1, wherein the elastic body is roller-shaped;
The elastic body according to item 2 or 3. 6) Forming a fluororesin layer on the surface of the first elastic body to form a multilayer body, and then using the multilayer body to cover the surface of the second elastic body. A method for manufacturing an elastic body having 7) The manufacturing method according to claim 6, wherein the first and second elastic layers are formed of fluororubber or silicone rubber. 8) The thickness of the fluororesin layer is 5 μm to 50 μm, and the first
The manufacturing method according to claim 6 or 7, wherein the elastic layer has a thickness of 0.2 mm to 5.0 mm, and the second elastic layer has a thickness of 0.5 mm or more. 9) The multilayer body is formed into a cylindrical shape, and the second elastic body layer is formed by filling the inside of the multilayer body with a second elastic body. The manufacturing method described in Section 8. 10) The manufacturing method according to claim 9, which comprises holding the outside of the molded multilayer body with a shape-retaining member, filling the inside with unvulcanized rubber, and then vulcanizing the unvulcanized rubber. .