JPS61258711A - Preparation of pellet and sheet of swellable polyvinyl chloride - Google Patents

Abstract

PURPOSE:To obtain water-swellable polyvinyl chloride having excellent elastic characteristics and being not easily destroyed by compression under highly water-absorbed state, by kneading polyvinyl chloride with a mixture obtained by kneading a high water-absorbable resin and a plasticizer. CONSTITUTION:The blending ratio of the composition consists of polyvinyl chloride 100pts. a highly water-solubable resin 10-200pts. a plasticizer 20-120pts. and a stabilizer 2-60pts. Using this blending ratio, the highly water- absorbable resin is placed in a mixer, then the plasticizer is supplied into it and the mixture is kneaded for about 20min. Polyvinyl chloride and the stabilizer are then mixed and kneaded for about more than 5min. The water- swellable resin composition thus obtd. is furthermore kneaded on a kneading roller at 120-180 deg.C for 7-8min and then is continuously taken off therefrom in a ribbonlike shape, which is supplied into a strainer extruder or a calender roll to prepare pellets or sheets.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a method for producing swellable polyvinyl chloride pellets and sheets. More specifically, there are various uses for pellets and sheets, but for example, in the case of water-stop backing for water pipes, when the pellet is immersed and swells, the force generated by the expansion of the idle volume can be utilized. This invention relates to a method for producing polyvinyl chloride pellets and sheets.

Conventionally, for example, backings for water pipes have been made of materials such as rubber, but when installing the backing, the seal portion of the water pipe must be tightened with sufficient force in order to achieve appropriate sealing pressure and frictional resistance. The adjustment is complicated, and this adjustment requires skill. Moreover, the sealing pressure of this backing decreases after many years of use, so it is necessary to apply more sealing pressure than necessary during installation, which shortens the life of the backing and prevents leakage due to aging. The backing had to be tightened again, requiring major construction work such as adjusting it or replacing the backing.

Swellable backings are available as a solution to these problems. Specifically, it is a mixture of super absorbent resin and natural rubber or ethylene vinyl acetate copolymer. These made it possible to obtain the necessary watertightness of the sealing surface by means of the pressure generated by the swellable member itself.

In other words, the tightening described above achieved a backing effect due to the self-sealing effect without any adjustment.

However, the lifespan of this backing itself was not semi-permanent because the material mixed with the superabsorbent resin itself is susceptible to aging.

The purpose of the present invention is to provide a method for producing swellable polyvinyl chloride pellets and sheets that can be used semi-permanently in various applications other than the above-mentioned backing. do.

The manufacturing method of this invention will be specifically explained. The blending ratio of this invention is 100 parts of polyvinyl chloride (parts by weight, the same applies below)
10 to 200 parts of super absorbent resin, 20-1 parts of plasticizer
20 parts and 2 to 6 parts of stabilizer. Preferably, in addition to the above ingredients, 0 to 10 parts of a superabsorbent resin processing aid and 0 to 30 parts of a vinyl chloride resin reinforcing agent are added.

At the above blending ratio, the superabsorbent resin, then the plasticizer, and (superabsorbent resin processing aid) were added to a stirrer and stirred for 20 minutes or more to completely disperse the superabsorbent resin in the 0]Fti agent. After that, transfer it to a super mixer and stir it again for at least 5 minutes at around 100°C, then mix polyvinyl chloride, a stabilizer, and (vinyl chloride resin reinforcing agent) in the same super mixer and stir it for at least 5 minutes. After that, knead with a pressure kneader or Bamba IJ + mixer at a temperature of around 150°C for 7 to 8 minutes, knead again with a mixing roll, and continuously take out the ribbon shape and put it into a strainer-po extruder to make pellets. or pass the ribbon shape through a calender to produce a sheet.

The table shows the change over time in the volumetric expansion coefficient of the swellable vinyl chloride produced by the above manufacturing method.

As is clear from the table above, the volumetric expansion of the present invention increases over time, and the physical properties after volumetric expansion at maximum water absorption, such as tensile strength and elongation, are superior to conventional superabsorbent resins. ing.

In addition, polyvinyl chloride has good durability and is semi-permanent, whereas conventional swellable members age prematurely, making it possible to solve the problems mentioned at the beginning.

As described above, in the present invention, polyvinyl chloride and spacing resin are mixed to produce homogeneous pellets and sheets, which is extremely effective.

Proceeding Amendment Rose (spontaneous) August 7, 1986 Director General of the Patent Office Mr. Kawaibe/, Indication of the case 1985 Filed Patent Application No. 100302 2 Name of the invention: 'If pickled' Rhinoceros 'November'b'yh bisonoshi 1
Relationship with the case of person making an amendment Patent applicant Katsuyama Sangyo Co., Ltd., 2-1 Sotono-cho, Higashi-ku, Osaka, Japan Voluntary amendment Numerical details: 1. Title of the invention; 2. Water-swellable resin and method for producing the same; 2. Claims/) A water-swellable resin comprising a superabsorbent resin, a polymerizing agent, and polyvinyl chloride.

2) A method for producing a water-swellable resin comprising a first step of kneading a super absorbent resin and a plasticizer, and a second step of mixing and kneading polyvinyl chloride into the kneaded product obtained in the first step.

3 Detailed explanation of the invention The present invention relates to a water-swellable resin and a method for producing the same.

Conventional water-swellable resins include KVA, urethane, rubber, etc. as mixed resins for super absorbent resins.

That is, since superabsorbent resins have the ability to absorb water, it is desirable to avoid oil-based resins as water-swellable resins.

However, conventional products made from water-swellable resins lack durability and have the disadvantage of being damaged during long-term use. For this reason, an incidental problem has arisen in which, for example, the work of replacing it with a new one is extensive.

The present inventor has now provided a water-swellable resin and a method for producing the same, in which a processed product of the water-swellable resin has excellent elasticity in a highly water-absorbing state and does not break easily even when compressed. Therefore, the present invention is a water W'B resin comprising a super absorbent resin, a plasticizer, and polyvinyl chloride, and the manufacturing method thereof includes a first step of mixing the crystalline water absorbent resin and the plasticizer. and a second step of mixing and kneading polyvinyl chloride into the kneaded material obtained in the first step.

To describe the embodiment of the present invention in detail, first, the spacing resin becomes a gel dispersed with a plasticizer (first step), and then polyvinyl chloride is docked thereon and kneaded with a stabilizer (second step). The company manufactures water-swelling genitalia.

The blending ratio of this invention may be determined according to the use of the processed product, and the blending ratio is 10 to 200 parts of super absorbent resin and 20 parts of plasticizer to 100 parts of polyvinyl chloride (same parts by weight).
Mix ~120 parts, stable part. Further, when the polyvinyl chloride resin has a polymerization degree of 500, 0 to 30 parts of an acrylic reinforcing agent is mixed in addition to the above-mentioned ingredients in order to improve physical properties.

At the above blending ratio, for example, put the super absorbent resin in a stirrer, then add the plasticizer (add super absorbent resin processing aids if necessary) and knead for about 20 minutes, (first step) 1 Next, polyvinyl chloride and a stabilizer (add a vinyl chloride resin reinforcing agent if necessary) are mixed and kneaded for about 5 minutes or more.

The water-swellable resin obtained in the above process was heated with a kneading roller for 7 hours while maintaining a temperature of 120"C to 180C.
After kneading for ~8 minutes, it is continuously taken out in the form of a ribbon, which is then put into a strainer-extruder and processed into pellets, or passed through calender rolls and processed into sheets.

Next, an example of changes over time in the volumetric expansion coefficient of the pellets obtained above is shown in the table.

Blending ratio: 100 parts of polyvinyl chloride (Sumiritsu EIX-11F, manufactured by Sumitomo Chemical Co., Ltd.)
Minikron 3000M manufactured by Mitsui Toatsu Chemical Co., Ltd.) / Super absorbent resin X00 parts (Sumikagel EIF-510 manufactured by Sumitomo Chemical Co., Ltd.) (
Kuraray Sobrene Chemical Co., Ltd. NK, Nigel) (Katsuyama Sangyo Co., Ltd., Y gel) ・Plasticizer 100 parts (Kyosai Hakko Kogyo Co., Ltd. DoP) ・Stabilizer 5 items (γ Deka, Argus Chemical (Katsuyama Sangyo Co., Ltd., DoP) MRK Co., Ltd., AC-169) As is clear from the table above, the volume expansion of the processed product according to the present invention increases over time, and the physical properties at maximum water absorption, such as tensile strength and elongation, are better than those of conventional products. superior compared to
Moreover, since the mixed resin for the super absorbent resin is polyvinyl chloride, it has good durability and can be used semi-permanently, eliminating the conventional disadvantages mentioned at the beginning. There is no sulfurization process, it can be molded under almost the same conditions as soft vinyl pellets, and it can be easily colored. Additionally, the processed product according to the present invention has superior light resistance compared to conventional products, so it is thought that the range of applications will be expanded.

The present invention is a water-swellable resin in which polyvinyl chloride is completely blended into a mixed material in which a super absorbent resin is dispersed with a plasticizer without separating, so the durability of this processed product, such as pellets, can be improved. The properties were extremely good compared to products processed using conventional water-swellable resins.

Moreover, as a result, it can be used as underground objects that strongly require durability and are difficult to replace, so the range of applications will be expanded compared to conventional products.

Claims (1)

[Claims] After putting the super absorbent resin and plasticizer into the stirrer and stirring,
A method for producing swellable polyvinyl chloride pellets and sheets, in which these are placed in a high-speed mixer, stirred again, polyvinyl chloride and a stabilizer are added thereto, stirred, kneaded, and then processed into pellets or sheets.