JPS6322981B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for molding a laminated rubber plate. In other words, the present invention relates to the molding of laminated rubber boards, such as floor rubber boards, where decorative elements are important as well as functionality. As shown in FIGS. 3 and 4, a vulcanizable rubber powder 4 composed of two or more colors is spread and filled over the entire surface of the cavity of a rubber plate vulcanization mold 7, and then the mold It is characterized in that vulcanizable unvulcanized rubber plates 5 of the same shape as the cavity are placed one on top of the other, and are heated under pressure using a press vulcanizer, laminated, and vulcanized. That is, the present invention provides a laminated rubber plate 1 having a surface with a random, multicolored speckled pattern or an elegant marble-like pattern and a surface rubber 2 with excellent functionality, and a method for molding the same.

Conventionally, there are the following methods for forming such a rubber plate.

Conventional method (1) As shown in Figure 2, rubber latex containing a vulcanizing agent is mixed with vulcanized rubber powder of two or more colors and dried to produce rubber powder 4' that can be vulcanized in multiple colors and vulcanized scrap rubber. Rubber latex containing a vulcanizing agent is mixed with the powder and dried to produce a vulcanizable rubber powder 6, and a vulcanizable rubber powder 4' composed of two or more colors is placed in the cavity of a vulcanization mold 7. After spreading and filling halfway, vulcanizable powder rubber 6 is further spread and filled on top of the rubber, and the rubber is compressed and laminated using a press vulcanizer using a push-type upper mold 9, and heated and vulcanized. A laminated rubber plate 1 is obtained by sulfurization. Although this laminated rubber plate also has excellent functions and surface patterns, it has the following drawbacks.

Disadvantages (1) Mixed latex of vulcanized rubber powder requires large equipment and long drying time to dry the moisture contained in the rubber latex.

Disadvantage (2) In order to provide superior functionality to the laminated rubber plate, a large amount of expensive latex is used, resulting in high material costs.

Disadvantage (3) Dry vulcanized rubber powder containing a large amount of rubber latex aggregates into large lumps or large particles, which requires loosening work, which is quite difficult.

Disadvantage (4) Rubber powder contains a large amount of air and has a porosity of 60 to 75% by volume, although it varies depending on the type of rubber and particle size. For this reason, a push-in upper mold 9 is required, and the cavity of the vulcanization mold 7 is deep and the thickness of the mold is large, resulting in poor heat conduction and a long vulcanization time to vulcanize a thick rubber plate.

Disadvantage (5) Unless the multi-colored vulcanizable rubber powder 4' and the vulcanizable rubber powder 6 are uniformly spread and filled over the entire surface of the cavity of the vulcanization mold, the fluidity of the rubber powder will be poor. Therefore, there is a drawback that the strength varies greatly within a single laminated rubber plate that is laminated and vulcanized.

Due to these shortcomings, laminated rubber plates, which have excellent decorative patterns, are no longer used.

Conventional method (2) Rubber powder is compression-molded into the vulcanization mold 7 and push-in upper mold 9 of the method of conventional method (1) without applying heat, and preformed into an unvulcanized rubber plate shape. It is possible to mold a laminated rubber plate exactly the same as the conventional method (1) by placing it in a normal rubber plate vulcanization mold and applying pressure and heat to vulcanize it. This method has the same drawbacks as the conventional method (1) except that the vulcanization time can be shortened.

Conventional method (3) A different color vulcanized rubber powder is kneaded into vulcanizable unvulcanized rubber, rolled, and used as surface rubber.A vulcanizable unvulcanized rubber plate is laminated with a base rubber plate. and fill it into the vulcanization mold cavity.
There is a method of laminating rubber sheets under pressure and heating and vulcanization molding to form a laminated rubber plate with a multicolored speckled pattern on the surface layer. This method is still in use today because the process is simple, but it has the following drawbacks. During rolling into a shape and vulcanization molding in a vulcanization mold cavity, different colored vulcanized rubber powder settles into the unvulcanized rubber, resulting in a small number of different colored speckled patterns that are unclear and have no decorative value. The biggest drawback is that it is inferior.

For this reason, a method has been used in which chips of unvulcanized rubber of a different color are sprinkled on top of the unvulcanized surface rubber plate to create a speckled pattern, but this method has the disadvantage that it is one step inferior in terms of decoration.

The present invention has been made as a result of various studies in order to improve these drawbacks and obtain a laminated rubber plate with excellent decorative value.
The surface rubber 2 formed from vulcanizable rubber powder 4, which is composed of several types of rubber powder with different colors and particle sizes, has an excellent pattern, and the porosity of the base rubber 3 is close to 0. When vulcanizable unvulcanized rubber plates 5 are combined and laminated, the laminated rubber plate 1 can be efficiently vulcanized and molded using a general rubber plate vulcanization mold without using the push-in upper mold 9, and the conventional method ( We discovered that the drawback of 1) can be improved.

That is, in the present invention, a vulcanizable rubber powder composed of two or more colors is spread and filled over the entire surface of a vulcanizing mold cavity, and a vulcanizable rubber powder having the same shape as the mold cavity surface is placed on top of this. It is characterized in that unvulcanized rubber plates are stacked one on top of the other, and then heated under pressure using a press vulcanizer, laminated, and vulcanized.

Further, in the present invention, the vulcanizable rubber powder includes 20 to 80 parts by weight of unvulcanized rubber powder and 80 to 20 parts by weight of vulcanized rubber powder.
It is a unique mixture consisting of parts by weight. In other words, in a vulcanizable rubber powder, a mixture of two or more colors consisting only of vulcanizable unvulcanized rubber can be vulcanized and molded by pressurization and heating in a vulcanization mold cavity. This has the disadvantage that the rubber particles flow and form a flowing pattern, making the pattern of each laminated rubber plate inconsistent. Therefore, vulcanized rubber powder is mixed with this to prevent the flowing pattern, thereby making the pattern uniform. . The mixing ratio varies depending on the particle size and plasticity of each rubber powder, as well as the required pattern, but it is unique in the range of 20 to 80 parts by weight of unvulcanized rubber powder and 80 to 20 parts by weight of vulcanized rubber powder. Advantageously, a mixture of

Furthermore, the present invention provides natural or synthetic rubber 100
Add 300 to 1,500 parts by weight of vulcanized rubber powder and the desired amount of vulcanizing agent, vulcanization accelerator, reinforcing agent, softener, coloring agent, and other rubber chemicals to the weight part, and mix it in a kneading machine. It is characterized in that it is kneaded to obtain a single color or multicolor vulcanizable rubber powder, and is used to form a laminated rubber plate of a single color or a mixture of different color rubbers. That is, vulcanizable rubber powder is the most excellent method in terms of manufacturing cost and pattern.

Depending on the type of rubber used and the type and amount of vulcanizing agents, reinforcing agents, fillers, softeners, and other rubber chemicals, 300 to 1500 parts by weight per 100 parts by weight of natural rubber or synthetic rubber. By kneading the vulcanized rubber powder, it is possible to obtain a vulcanizable rubber powder in which the unvulcanized rubber acts as a binder and coats the vulcanized rubber powder. At this time, if there are two or more colors,
The use of vulcanized rubber powders with different particle sizes results in a bedable rubber powder that molds excellent patterns, and when used alone, it results in a surface layer rubber with an excellent multicolored pattern. Furthermore, when two or more of these are mixed in a blender, a surface layer rubber with a more complex color pattern can be obtained. It is not preferable to use more than 1500 parts by weight of vulcanized rubber powder per 100 parts by weight of natural rubber or synthetic rubber because the physical properties of the surface rubber will deteriorate.

Furthermore, the present invention provides (a) natural or synthetic rubber
For 100 parts by weight, 300 to 1500 parts by weight of vulcanized rubber powder, and the desired amount of vulcanizing agent, vulcanization accelerator, reinforcing agent,
A monochromatic or multicolored vulcanizable rubber powder obtained by adding a softener, a coloring agent, and other rubber chemicals and kneading it in a kneading machine, (b) a vulcanized rubber powder, and (c) an uncured rubber powder. The vulcanizable rubber powder is characterized in that the vulcanizable rubber powder is a unique mixture of two or three of the vulcanized rubber powders.

A method for improving the pattern and texture of surface rubber by adding a different color vulcanized rubber powder or a different color unvulcanized rubber powder to the vulcanizable rubber powder, and mixing the two in a blender. It is.

Furthermore, in the present invention, the thickness of the colored patterned surface layer rubber formed by vulcanization using vulcanizable rubber powder composed of two or more colors is 40% or less of the thickness of the laminated rubber plate. Since the porosity of the vulcanization mold cavity is 60 to 75%, even if the top surface of the vulcanization mold cavity is filled with vulcanizable rubber powder and molded, the surface rubber layer will have a thickness of 40% of the depth of the vulcanization mold cavity. In other words, it is easier to mold a surface layer rubber having a thickness of 40% or less of the thickness of the laminated rubber plate.

The effects of the present invention are as follows.

(1) Among the methods for forming laminated rubber plates with speckled or marble-like patterns, this method allows for the most combination of color tones and textures, and also forms laminated rubber plates with clear and elegant patterns. This is a possible method.

(2) According to the method set forth in claim 3 for producing a vulcanizable rubber powder composed of two or more colors forming the surface rubber, (a) No expensive binder is required and the material cost is low. It is.

(b) By using a kneading machine such as a Banbury mixer or a pressure kneader, vulcanizable rubber powder can be produced efficiently and with a small number of man-hours.

(c) Even if the vulcanized rubber powder is an inexpensive general-purpose rubber (natural rubber, SBR, etc.), it is possible to mold a laminated rubber plate with excellent weather resistance by using chlorosulfonated polyethylene (Hypalon) as the binder rubber. can do.

(3) By mixing vulcanizable rubber powder composed of two or more colors for the surface layer rubber using a large-capacity ribbon blender to form a large lot, it is possible to prevent variations in the surface pattern of the laminated rubber plate.

(4) Since rubber powder is used for the surface layer rubber, the air inside the vulcanization mold cavity is well vented during the molding process, and there is no possibility of defective products due to bubbles or blisters in the surface layer rubber.

(5) Even if the vulcanizable rubber powder for the surface layer rubber spreads somewhat unevenly, the base rubber is an unvulcanized rubber plate that can be vulcanized, so it has good fluidity inside the vulcanization mold cavity. Since the pressure becomes uniform, the molded laminated rubber plate exhibits uniform physical properties.

Next, examples of the present invention will be described.

Example [Beige rubber compound] Natural rubber 70 SBR 30 Valve handle 0.5 Yellow pigment 2 Surface treatment calcium carbonate 130 Stearic acid 1 Phenolic anti-aging agent 2 Titanium oxide 4 Zinc white 5 Process oil 3 Vulcanization accelerator 1.5 Sulfur Yellow 2.5 Total 251.5 [Contains brown Hypalon] Hypalon #40 100 Vulcanization accelerator TRA 2 Magnesium oxide 4 Pentaerythritol 2 Precipitated calcium carbonate 100 Process oil 10 Chlorinated paraffin #40 10 Valve Handle 3 Carbon black 0.1 231.1 [Contains black rubber for base] ] Natural rubber 60 Recycled tire rubber 80 Hard clay 30 Precipitated calcium carbonate 80 Stearic acid 1 Zinc white 5 Vulcanization accelerator 1.5 Phenol anti-aging agent 1 Sulfur Yellow 2.5 261 Beige colored rubber compound is kneaded and rolled to about 10 mm.
rubber plate. This is vulcanized in a vulcanizer, and the vulcanized rubber is turned into beige-colored vulcanized rubber powder that passes through a 16-mesh sieve in a rubber crusher.

Knead the brown Hypalon mixture. When 231.1 parts by weight of this brown Hypalon kneaded rubber and 500 parts by weight of beige vulcanized rubber powder are kneaded in a Banbury mixer, a vulcanizable rubber powder 4 consisting of two colors, beige and brown, is obtained. Black rubber compound for the base,
The mixture is kneaded and rolled to 4 mm and 8 mm, and cut to the same shape as the cavity surface of the vulcanization mold 7 to obtain black vulcanizable unvulcanized rubber plates 5 of 4 mm and 8 mm.

Molding example 1 As shown in Figure 3-a, the depth of the vulcanization mold 7 is 6 mm.
A vulcanizable rubber powder 4 composed of beige and brown colors is spread and filled into the cavity, and a 4 mm black vulcanizable unvulcanized rubber plate 5 is placed on top of it and pressed. Pressure is applied by a vulcanizer,
They were heated, laminated, and vulcanized to form a 6 mm laminated rubber plate consisting of a 2 mm surface layer with beige and brown patterns and a 4 mm black base layer, as shown in Figure 3-b.

Molding example 2 As shown in Figure 4-a, the depth of the vulcanization mold 7 is 10 mm.
A vulcanizable rubber powder 4 composed of beige and brown colors is spread and filled into the cavity to a depth of 6 mm, and an 8 mm black vulcanizable unvulcanized rubber plate 5 is placed on top of it. Using a press vulcanizer, the rubber is laminated and vulcanized under pressure and heat, and as shown in Figure 4-b, a 2 mm surface rubber layer with beige and brown patterns and an 8 mm black base layer are laminated. 10mm
It is possible to form laminated rubber plates.

This example was explained using the simplest combination of two colors, but by combining the above with multiple colors, a laminated rubber plate with an elegant decorative pattern on the surface layer can be produced and molded using a relatively simple process. It's a method.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a laminated rubber plate according to an embodiment of the present invention, Fig. 2-a is a cross-sectional view of a molding structure of a laminated rubber plate using rubber powder of a conventional method, and Fig. 2-b is a conventional method. Figure 3-a is a cross-sectional view of a laminated rubber plate molded using the rubber powder of the present invention, and Figure 3-b is a cross-sectional view of the laminated rubber plate molded using the method of the present invention. FIG. 4-a is a cross-sectional view of the molding structure of a laminated rubber plate formed by the method of the present invention, and FIG. 4-b is a cross-sectional view of a laminated rubber plate molded by the method of the present invention. 1...Laminated rubber plate, 2...Surface rubber with a multicolored pattern of the laminated rubber plate, 3...Lower layer rubber (base rubber) of the laminated rubber plate, 4,4'...Constructed of two or more colors Vulcanizable rubber powder, 5... Vulcanizable unvulcanized rubber plate, 6... Vulcanizable rubber powder, 7... Vulcanization mold, 8... Vulcanization mold upper mold, 9... ...Push type upper mold.

Claims (1)

[Claims] 1. A vulcanizable rubber powder composed of two or more colors is spread and filled over the entire surface of a vulcanization mold cavity,
A vulcanizable unvulcanized rubber plate having the same shape as the mold cavity surface is placed on top of this, and this is heated under pressure using a press vulcanizer, and then laminated and vulcanized. Method for forming laminated rubber plates. 2 Vulcanizable rubber powder is unvulcanized rubber powder 20~
The method of forming a laminated rubber plate according to claim 1, wherein the mixture is a unique mixture consisting of 80 parts by weight of vulcanized rubber powder and 80 to 20 parts by weight of vulcanized rubber powder. 3 300 parts per 100 parts by weight of natural or synthetic rubber
~1500 parts by weight of vulcanized rubber powder and the desired amount of vulcanizing agent, vulcanization accelerator, reinforcing agent, softening agent, coloring agent and other rubber chemicals are added and kneaded in a kneading machine to form monochrome or multi-colored powder. 2. The method of forming a laminated rubber plate according to claim 1, wherein the colored vulcanizable rubber powder is used to form a laminated rubber plate made of a single rubber or a mixture of different colored rubbers. 4 (a) For 100 parts by weight of natural or synthetic rubber,
Obtained by adding 300 to 1,500 parts by weight of vulcanized rubber powder and desired amounts of vulcanizing agent, vulcanization accelerator, reinforcing agent, softening agent, coloring agent, and other rubber chemicals and kneading in a kneading machine. Vulcanizing the mixture of two or three of monochrome or multicolor vulcanizable rubber powder, (b) vulcanized rubber powder, and (c) unvulcanized rubber powder. The method for molding a laminated rubber plate according to claim 1, wherein the rubber powder is made into a rubber powder. 5. Claim 1, in which the thickness of the colored patterned surface layer rubber, which is vulcanized and molded using vulcanizable rubber powder composed of two or more colors, is 40% or less of the thickness of the laminated rubber plate.
A method for forming a laminated rubber plate as described in .