KR100280199B1 - Rubber composition for bladder usable for drinking water - Google Patents

Abstract

The present invention relates to a bladder rubber composition for drinking water. The rubber composition according to the present invention is 60 to 70% by weight of butyl rubber, 20 to 28% by weight of carbon black, 2 to 4% by weight of castor oil (CASTOR OIL, castor oil), 0.1 to 0.8% by weight of stearic acid, dibenzothiazil Dibenzothiazyl disulfide (DM) 0.5 ~ 1.5 wt%, sulfur 0.2 ~ 3 wt% and zinc oxide 2 ~ 4 wt%, so mechanical properties such as tensile strength, elongation and hardness are improved, so it can be used as rubber composition for bladder. Suitable for In addition, the bladder rubber composition according to the present invention is stable for a nontoxic test (elution test) and is suitable for drinking water, is heat resistant, durable, and has a property of not being easily cured.

Description

Rubber composition for drinking water {Rubber composition for bladder usable for drinking water}

The present invention relates to a bladder rubber composition for drinking water, and more particularly to a bladder rubber composition for drinking water containing butyl rubber improved mechanical properties and chemical resistance.

CR (polychloroprene, neoprene) or EPDM (ethylene-propylene-diene rubber) has been used as the main component of the conventional rubber. Neoprene rubber has high tensile strength, resists oxidation and ozone, and has good durability, but is expensive compared to other elastomers, and EPDM rubber has been used in construction materials, automobiles, and machinery parts.

Synthetic rubber, the main component of which is neoprene rubber or EPDM rubber, is easily cracked, weak in durability, and harmful substances are eluted at temperatures of 120 ° C. or higher, which makes them unsuitable for use in preparing bladder for drinking water. In addition, due to the characteristics of the structure used such as bladder, synthetic rubber products that continue to shrink and expand repeatedly should maintain flexibility, but synthetic rubber, which is a main component of neoprene rubber or EPDM rubber, has many problems.

Therefore, there is a need for a rubber composition suitable for producing bladder, which is resistant to heat and more flexible.

It is an object of the present invention to provide a bladder rubber composition for drinking water, which is resistant to heat and is durable by using butyl rubber and various additives, and which has excellent chemical resistance.

The bladder rubber composition for drinking water according to the present invention is a new rubber composition that is resistant to heat and is not easily cured even by continuous shrinkage and expansion. Butyl rubber, carbon black, castor oil (CASTOR OIL, castor oil), stearic acid, dibenzothiazyl disulfide Feed (Dibenzothiazyl disulfide, DM), sulfur and zinc oxide, more specifically 60-70% by weight butyl rubber, 20-28% by weight carbon black, 2-4% by weight castor oil, stearic acid 0.1-0.8 wt%, dibenzothiazyl disulfide (DM) 0.5-1.5 wt%, sulfur (S) 0.2-3 wt% and zinc oxide (ZnO) 2-4 wt%.

The butyl rubber contained in the bladder rubber composition for drinking water according to the present invention is a polymer material in which a large amount of isobutylene units and a small amount of isoprene are irregularly distributed in a molecule, and generally has a saturation of 0.5 to 2.5 mol%. Isobutylene-isoprene copolymer rubber. Butyl rubber is amorphous under normal conditions, but when it is stretched, it crystallizes like a fiber. Since isoprene in rubber has a 1,4-linked structure, it is formed as a linear polymer, and unlike natural rubber, it does not crystallize even when cooled. And does not lose flexibility even at -50 ° C.

In addition, butyl rubber has excellent chemical resistance, very low gas permeability, and is less susceptible to aging by oxygen than other elastomers except silicone and softens rather than broken by oxidation. It is more resistant to ozone than natural rubber, has high acid resistance, good solvent resistance, and has excellent mechanical and electrical properties. It is used for the interior of tire tubes and tubeless tires, and is also used for the production of mechanical products.

The bladder rubber composition for drinking water according to the present invention includes dibenzothiazyl disulfide (DM) as a vulcanization accelerator and carbon black as a reinforcing agent. In addition, stearic acid contained in the bladder rubber composition for drinking water according to the present invention is used as a vulcanization accelerator and acts as a dispersant to improve the dispersion of carbon black.

Meanwhile, the method for preparing the bladder rubber composition for drinking water according to the present invention includes material preparation → mixing and kneading → maturation (48 hours) → sutoring (twice in an extruder) → embossing (in embossing M / C) → frangie Processing and cutting of the bureda (press and workshop) → molding → vulcanization → washing → inspection, the compounding and kneading is mixed with the compounding components in a conventional mixer, and roll, compression molding machine, extrusion molding machine or injection molding machine It is molded in a predetermined form by the same conventional rubber molding machine.

The bladder rubber composition for drinking water of the present invention is suitable for the production of various rubber products by molding and vulcanization, and is particularly effective for producing rubber for bladder.

Hereinafter will be described an embodiment according to the present invention. However, the present invention is not limited to the examples.

Example 1

65% by weight butyl rubber, 26% by weight carbon black, 3% by weight castor oil (castor oil), 0.7% by weight stearic acid, 1.3% by weight dibenzothiazyl disulfide (DM), 1% by weight sulfur (S) and oxidation After mixing and kneading 3% by weight of zinc (ZnO) and aging for 48 hours, it proceeds according to the above-described manufacturing method to obtain a vulcanizate of the resulting rubber composition.

Example 2

Butyl rubber 64.72 wt%, carbon black 25.89 wt%, castol oil (castor oil) 3.24 wt%, stearic acid 0.65 wt%, dibenzothiazyl disulfide (DM) 1.29 wt%, sulfur (S) 0.97 wt% and oxidation 3.24% by weight of zinc (ZnO) is blended and kneaded, aged for 48 hours, and then proceeded to the above-described preparation method to obtain a vulcanizate of the resulting rubber composition.

The vulcanizates obtained in Examples 1 and 2 and vulcanizates of conventional rubber are subjected to tensile strength, elongation and hardness tests in accordance with KSM 6518-96 and the results are shown in Table 1.

Test Items Conventional rubber Example 1 Example 2 Tensile Strength (kgf / ㎠) Elongation (%) Hardness (HS) 119.365060 16476055 164.676055 Tensile strength change rate (%) Elongation change rate (%) Hardness change (hs) after aging (100 ± 1 ℃ × 24hrs) -8.1-7.55 -3.1-4.85 -3.2-4.75

Comparing the conventional rubber with Examples 1 and 2, it can be seen that the mechanical properties are improved because the bladder rubber composition for drinking water of the present invention has excellent tensile strength and elongation.

On the other hand, the results of the dissolution test of Examples 1 and 2 according to KSM 6613-93 are shown in Table 2.

Test Items unit Result Free sulfur % 0.05 Elution Odor and taste Turbidity Color and potassium manganate consumption Reduction of residual chlorine -Dodoppmppm 1 or less 5 or less 0.80.9

As shown in Table 2, Examples 1 and 2 can be seen that the components eluted at a high temperature is non-toxic and suitable for use in drinking water.

New drinking water bladder rubber composition developed by the present inventor is excellent in tensile strength, elongation rate, hardness, and the like, and is stable as a result of non-toxic test (elution test), and is also suitable for producing rubber products for drinking water. Therefore, a rubber product made of a conventional rubber composition hardens and does not withstand continuous shrinkage and expansion, and easily cracks, and at high temperatures, a substance harmful to the human body is eluted from rubber to solve problems that are inadequate for use in drinking water. In addition, the bladder rubber composition for drinking water according to the present invention is particularly suitable for producing bladder for drinking water, because it is heat-resistant, durable, and not easily cured and non-toxic.

Claims (1)

Butyl rubber 60-70 wt%, carbon black 20-28 wt%, castol oil (castor oil) 2-4 wt%, stearic acid 0.1-0.8 wt%, dibenzothiazyl disulfide (DM) 0.5-1.5 wt% Bladder rubber composition for drinking water, containing 0.2-3% by weight of sulfur (S) and 2-4% by weight of zinc oxide (ZnO).