JPS5814300B2 - Method for producing flexible rubber-like porous material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rubber-like porous body having water absorbing properties, which is made mainly of vulcanized rubber powder and mixed and sintered with porous secondary particulate vinyl chloride resin.

The applicant has already filed patent No. 597, 891 (
Holds a patent for ``microporous polyvinyl chloride separator'' (dated February 24, 1971).

This patent describes the mixing of polyvinyl chloride, which is made up of a large number of primary particles of 0.5 to 50 microns (l4) agglomerated to form secondary particles with a particle size of 10 to 100 microns, and dense spherical polyvinyl chloride with a particle size of 10 to 80 microns. The present invention relates to a microporous separator for storage batteries that is formed by sintering and has a two-stage porous structure of primary particles and secondary particles.

The present application is a development of the patented invention.

Generally, it is already known to obtain porous bodies by sintering plastic particles, but these bodies are hard and brittle and have no rubber elasticity at all.

Porous bodies having rubber elasticity include spongy bodies made from latex.

However, although it has elasticity, it has the disadvantage of large bubbles.

Alternatively, soluble substances such as salt, inorganic substances such as sulfate, and organic substances such as starch are mixed with rubber, and after molding, these substances are removed with an aqueous solution of acid or alkali, or finely powdered calcium carbonate, etc. is added and acid is removed. There is a method of obtaining a rubber-like foam by using and removing the foam, but this method has the drawback of requiring many steps and increasing costs.

The present invention does not require a special treatment method of mixing inorganic or organic substances to produce a rubber-like porous body, but uses extremely fine vulcanized rubber powder to impart appropriate flexibility and hardness to the porous body. The object of the present invention is to obtain a material that is flexible enough not to break even when bent 180 degrees.

The manufacturing process for this product is extremely simple.

That is, in the present invention, extremely fine vulcanized rubber powder or vulcanized rubber foam powder and a plasticizer are mixed in the first step, polyvinyl chloride is added to this, and the mixture is gently mixed to the extent that the individual particles are not destroyed. , the mixture was filled into a mold and heated using a heating press at a predetermined temperature (140-150°C) and time (5-150°C).
After heating under pressure for 10 minutes), the mold is removed from the mold.

The resulting sintered particles form a rubber-like porous body with appropriate voids.

As mentioned above, the process is simple as it only requires two steps: mixing and heat treatment, and compared to the conventional manufacturing method of porous bodies, the soluble substances mixed inside are dissolved and extracted through special treatment. The process has features that are not required at all.

Therefore, it has two major features: it has extremely high flexibility in terms of functionality, and it simplifies the process.

The vulcanized rubber powder or vulcanized rubber foam powder used in the present invention can be any type of natural rubber or synthetic rubber, such as natural rubber, isoprene rubber, styrene-ptadiene rubber, nitrile rubber, and chloroprene rubber. Rubber, butyl rubber, ethylene propylene rubber, urethane rubber, etc. Vulcanized products mixed with various compounded chemicals such as vulcanizing agents, vulcanization accelerators, vulcanization aids, fillers, reinforcing agents, softeners, organic or inorganic pigments, etc. It is finely ground.

The resin to be mixed is polyvinyl chloride (PVC straight resin), but many synthetic resins can be used as long as they can form fine particles.

Examples of the plasticizers used include phthalic acid, esters, phosphoric esters, epoxidized vegetable oils, polyester plasticizers, adipic acid polyesters, liquid NBR, and chlorinated paraffins.

The present invention is most suitable for printing rolls, rolls for office machines, rolls for electronic equipment, molded products, and printing materials.

Next, examples of the present invention will be described.

Example 1 100 parts by weight of a vulcanized rubber powder made of an SBR compound that has passed through a sieve with an opening of 149 μm and 30 parts by weight of a plasticizer DOP (dioctyl phthalate) are placed in a mixer and mixed gently to form a porous rubber mixture. Secondary particulate polyvinyl chloride (
PVC straight resin, average particle size 40 microns) 8
Add 0 parts by weight and mix gently again to make volume ratio 300%.
Using a heating and pressing press, it was heated and pressed at 145° C. for 10 minutes.

As a result, there was no abnormality in the 180 degree bending test, JISA
The hardness measured by a mold hardness meter was 46.

The porosity was 18%. Example 2 70 parts by weight of NBR and PVC passed through a 149μ sieve
100 parts by weight of a vulcanized rubber powder consisting of a blend of polyblended NBR as a main component and a plasticizer DBP.
30 parts by weight of dibutyl phthalate, 1 part by weight of crosslinking agent triazine (6dibutylamino 1,3.5} riazine 2,4 dithiol) and 3 parts by weight of stabilizer (thiobutyltin) were gently mixed in a mixer. Secondary particulate polyvinyl chloride (PVC straight resin, average particle size 4
0 micron) was added and gently mixed again, filled into a mold at a volume ratio of 300%, heated and pressure molded at 180°C for 20 minutes using a heating and pressing press, and then heated to 120°C.
Cool it down and take it out.

As a result, there was no abnormality even when the product was bent 180 degrees in a bending test.

Further, the hardness was measured with a JISA type hardness meter and was found to be 45.

This porosity was 10%.

Example 3 100 parts by weight of a fine powder of a vulcanized rubber foam mainly composed of SBR that has passed through a sieve with an opening of 149 microns and 80 parts by weight of a plasticizer DBP (dibutyl phthalate) are placed in a mixer and gently mixed. Furthermore, polyvinyl chloride (PVC
80 parts by weight of straight resin (average particle size 70 microns) was added thereto and gently mixed again, filled into a mold at a volume ratio of 300%, and heated and pressure molded at 140° C. for 10 minutes using a heat and pressure press.

As a result, there was no abnormality even when the product was bent 180 degrees in a bending test.

The hardness was 45 using a JISA type hardness meter.

The porosity was 21%.

Example 4 100 parts by weight of vulcanized rubber powder based on natural rubber passed through a sieve with an opening of 149 microns and plasticizer DBP (
Add 9 parts by weight of dibutyl phthale}) to a mixer and mix gently, then add 80 parts by weight of polyvinyl chloride (PVC straight resin, average particle size 70 microns) and mix gently again. The mixture was filled into a mold and heated and pressure molded at 150° C. for 8 minutes using a heat and pressure press.

As a result, there was no abnormality at all in the 180 degree bending test, and the hardness was 42 on a JISA type hardness tester.

This porosity was 19%. Reference example 1 SBR100 passed through a sieve with an opening of 149 microns
Parts by weight, 80 parts by weight of polyvinyl chloride, and 80 parts by weight of plasticizer were placed in a mixer and gently mixed.

The mixture will not be homogeneously mixed but will be non-uniformly mixed.

This was filled into a mold with a volume of 300%, and molded under the same conditions as Example 3.

The resulting product was bent 180 degrees and cracked, resulting in JISA
When the hardness was measured using a mold hardness meter, it varied from 35 to 55.

In addition, some portions had no holes.

Claims (1)

[Claims] 1. Vulcanized rubber powder or vulcanized rubber foam powder of a rubber compound mainly composed of natural rubber, synthetic rubber, or a mixture of these and synthetic resins having a particle size that can pass through a sieve with an opening of 149 microns. 70 parts by weight, 30 to 50 parts by weight of polyvinyl chloride agglomerated from primary particles with a particle size of 0.5 to 5 microns and formed into secondary particles with a particle size of 10 to 100 microns;
and 10 to 35 parts by weight of plasticizer in the mixing order,
A flexible product characterized by mixing vulcanized rubber powder or vulcanized rubber foam powder with a plasticizer, then polyvinyl chloride with or without the addition of a crosslinking agent and a stabilizer, and sintering this mixture. A method for producing a porous rubber material.