JPH0480957B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a packing material that expands with water and exhibits high sealing properties, and more specifically, the present invention relates to a packing material that expands with water and exhibits high sealing properties. The present invention relates to a method for manufacturing an expandable packing material.

Conventionally, it is generally known that a resin is used alone as a cross-linked water-swellable rubber, but this has a large volume reduction when swollen upon water absorption and volume when dried after water absorption, resulting in a poor sealing effect. I can't perform to my full potential. Furthermore, it is not effective because the water-absorbing resin has a property of separating from the rubber phase and leaching into the water when swollen in water, resulting in a volume reduction. The present invention
It was developed to eliminate these disadvantages peculiar to water-absorbing resins, and its purpose is to improve the elasticity and water-swellability of rubber, and to prevent volume reduction over time after expansion. The purpose of the present invention is to produce a novel packing material having the ability to minimize swelling return. Hereinafter, the structure of the present invention and practical effects will be described in detail with reference to Examples.

The composition of the water-swellable packing material of the present invention contains styrene-butadiene rubber, natural rubber, butadiene rubber, acrylonitrile-butadiene rubber, butyl rubber, chloroprene rubber, acrylic rubber, ethylene-propylene rubber, isoprene rubber, and recycled tire rubber, recycled butyl. Rubber is used. The polymer content in these compositions is 15 to 60% by weight.

Next, as water-absorbing resins, starch-based polymers,
Cellulose polymers, polyacrylic polymers, acrylate polymers, isobutylene polymers, polyvinyl alcohol polymers, and the like are used. The resin content in the composition is 5 to 80% by weight, and as the expandable cement, a calcium sulfoaluminate expander, a lime-gypsum expander, or the like is used. The lime-gypsum-based swelling agent that occupies the composition is an expansive cement mixture, and all of these are ettringite (hydrated sulfate of calcium and aluminum) formed by hydration of calcium sulfonate in the cement. It utilizes the expansion that results from formation, and is also known as a "static rock crushing material." In the present invention, for example, Expan manufactured by Onoda Cement Co., Ltd. is used after adjusting the particle size. The swelling agent is suitably used in an amount of 5 to 70% by weight.

Fillers, reinforcing agents, coloring agents, vulcanization aids, activators, tackifiers, vulcanization accelerators, vulcanizing agents, lubricants, softeners, foaming agents, foaming aids, etc. are used to produce the packing material of the present invention. These ingredients are added in appropriate amounts as needed, but the proportions used vary depending on the purpose of use. The manufacturing operation is carried out by masticating the polymer and then adding and mixing the resin and the swelling agent in one or several batches. As the kneading material, a usual kneading material such as a roll, a kneader, a Banbury, etc. is used. For molding materials, extrusion molding machines, press molding machines, calendar molding machines, etc. are used, and for vulcanization materials, press vulcanization machines, can vulcanization machines, UHF vulcanization machines, Glace beads continuous vulcanization machines, round vulcanization machines, etc. are used. A press vulcanizer or the like is used to mold and vulcanize the material into a belt, rod, plate, disk, ring, sheet, etc., depending on the application.

The packing material manufactured in this way has good rubber elasticity and compression recovery properties, and is compatible with the mating material. It can be used in areas where conventional water-stopping materials have been used, such as joints, concrete joints, and manholes.

As described above, the water-swellable packing material of the present invention contains 10 to 100 parts by weight of a resin that is incompatible with the polymer,
This is a new packing material consisting of 10 to 200 parts by weight of a polymer and an expanding agent that is incompatible with the resin. Immediately after the resin and expanding agent are installed in the gap, the packing material expands and internal pressure builds up naturally. It can exhibit superior water-stopping material performance and sealing function, and can increase long-term water-stopping effects.

Examples of the present invention will be described below.

Example 1 100 parts of natural rubber, 5 parts of zinc white, vulcanization accelerator
DM0.2 parts, vulcanization accelerator M0.4 parts, vulcanization accelerator D0.6
After kneading 1 part of stearic acid, 2 parts of sulfur, 50 parts of dixie clay, 30 parts of resin, 40 parts of Expan, and 40 parts of process oil in a roll, 5 m/m
A packing material was produced by vulcanization in a slap mold, and its expansion rate was 36% after 24 hours, 140% after 7 days, and 250% after 14 days.

Furthermore, after 21 days, we measured the expansion rate over a long period of time.
230%, and 220% after 28 days.

Example 2 70 parts of natural rubber, 60 parts of recycled tires, 5 parts of zinc white,
Vulcanization accelerator DM 0.2 parts, vulcanization accelerator M 0.4 parts, vulcanization accelerator D 0.6 parts, stearic acid 1 part, sulfur 2 parts,
40 parts of resin, 50 parts of Expan, 40 parts of process oil
As a result of the same experiment as in Example 1, the expansion rate was
42% after 24 hours, 220% after 7 days, 310% after 14 days
It was hot.

In addition, the decrease in expansion rate on long-term days was 280% after 21 days and 275% after 28 days.

Comparative example 1 70 parts of natural rubber, 60 parts of recycled tires, 5 parts of zinc white,
Vulcanization accelerator DM 0.2 parts, vulcanization accelerator M 0.4 parts, vulcanization accelerator D 0.6 parts, stearic acid 1 part, sulfur 2 parts,
As a result of experimenting in the same manner as in Example 1 using 20 parts of Dixie clay, 30 parts of white carbon, 40 parts of resin, and 40 parts of process oil, the expansion rate was 28% after 24 hours, 7.
It was 110% after 1 day and 230% after 14 days. Also, the decrease in the expansion rate on long-term days is 170% after 21 days and 140% after 28 days.
As shown above, it was found that the swelling return was significantly large.

If the packing material according to the present invention is used in this way, the resin and expandable cement will naturally apply internal pressure due to the expansion of the packing material immediately after it is installed in the gap, and it will exhibit water-stopping and sealing functions.
It can improve the long-term water stopping effect.

Claims (1)

[Claims] 1 Crosslinkable natural rubber, styrene-butadiene rubber, butadiene rubber, acrylonitrile-butadiene rubber, neoprene rubber, isobutylene rubber, isoprene rubber, ethylene-propylene rubber, and recycled rubber alone or a blend of each polymer, 100 parts by weight 10 to 100 parts by weight of a water-absorbing resin that is incompatible with the polymer,
Furthermore, expandable cement is added to 100 parts by weight of polymer,
A method for producing a rubber packing material, which comprises mixing and kneading 10 to 200 parts by weight.