JPS62106979A - Water-swellable waterproof material - Google Patents

Abstract

PURPOSE:To provide a water-swellable waterstop having low hardness at low temp. and excellent swell characteristics at low temp. and workability at low temp., by mixing a water-insoluble high-molecular compsn. consisting of a chlorinated polyethylene and polyisobutylene, with a highly water-absorbing resin and molding the mixture. CONSTITUTION:100pts.wt. water-soluble high-molecular compsn. (A) consisting of 30-95wt% chlorinated polyethylene and 70-5wt% polyisobutylene is mixed with (B) 15-100pts.wt. highly water-absorbing resin having water absorption capacity of 50-1,000 times its own wt. Then, the mixture is molded to give the intended water-swellable waterstop having a hardness below 65 at 2 deg.C. As the component B, a highly water-absorbing resin yielded by crosslinking a polymer containing as a monomer component an alpha,beta-unsatd. compd. having in a molecule one or two carboxyl groups or groups which can be converted into carboxyl groups by the use of a crosslinking agent is pref. used.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention relates to water-swellable fasteners, more specifically, water-swellable fasteners that have excellent low-temperature expansion properties, low hardness at low temperatures, and excellent low-temperature workability. This invention relates to a water-swellable waterproof material.

Stopping timbers are used in civil engineering and architectural work, at places where mortar and concrete are installed, and at places where water pipes are connected.
Break, my, I? t1st floor?)' (n line'm h
111 le l'-7, I! It is widely used to fill R gaps to stop water leakage.

BACKGROUND OF THE INVENTION Conventionally, water-swellable compositions such as superabsorbent resins, diene rubbers, vulcanizing agents, vulcanization accelerators,
Resin compositions that swell on contact with water have been developed, consisting of vulcanizates of mixtures of fillers, anti-aging agents, etc., or in combination with such water-swellable compositions and non-swellable compositions, such as diene-based compositions. It has been proposed to stop water by combining a vulcanized product of a mixture of rubber, a vulcanizing agent, a vulcanization accelerator, a filler, an anti-aging agent, etc. 57-135160).

However, these proposals require a vulcanization process, which poses problems in the productivity of the water-stopping material, and in addition, the diene rubber is vulcanized and cannot be reused. be.

Also known is a water-swellable composition in which a flexible thermoplastic synthetic resin such as an ethylene-vinyl acetate copolymer contains a superabsorbent resin (Japanese Patent Laid-Open No. 55-3424).

However, water-swellable compositions using thermoplastic synthetic resins such as ethylene-vinyl acetate copolymers and soft vinyl chloride resins are highly temperature dependent and have a narrow usable temperature range.
In particular, there are problems such as poor low-temperature workability and low low-temperature expansion properties.

Problems to be Solved by the Invention The present inventors have worked diligently to solve these problems and provide a water-swellable fastener that has excellent low-temperature workability and low-temperature expansion properties and does not require a vulcanization process. As a result of repeated research, we have found that a product made by using chlorinated polyethylene and polyisobutylene in a predetermined ratio as water-insoluble polymeric substances, and adding a super absorbent resin having the required water absorption capacity in a predetermined ratio. ,
We have found a scale suitable for this purpose, and have completed the present invention based on this knowledge.

Means for solving the problems, that is, the present invention provides (8) chlorinated polyethylene 30-
95% by weight of a water-insoluble polymer composition IQQ consisting of 70-5% by weight of polyisobutylene and (B) 15-15% of a super absorbent resin having a water absorption capacity of 50-1000 times its own weight.
The present invention provides a water-swellable stopper which is formed by molding a mixture containing 100 parts by weight, and has a hardness of less than 65 at a temperature of 2°C.

The water-insoluble polymer substance used in the water-stopping material of the present invention is a combination of chlorinated polyethylene and polyisobutylene, and as the chlorinated polyethylene, a wide range of molecular weights from 20,000 to 200,000 can be used, but chlorine A content in the range of 25 to 45% by weight, generally 30 to 40% by weight is preferred in terms of having rubbery properties, and a crystallinity of 10% or less is preferred in terms of flexibility. On the other hand, polyisobutylene having a wide range of molecular weights from 100,000 to 5,000,000 can be used.

In the present invention, the weight ratio of the chlorinated polyethylene and polyisobutylene is 3:1 to 9.5:20.5,
Preferably, the ratio is selected in the range of 5:5 to 8:2. If the ratio of chlorinated polyethylene to polyisobutylene is less than the above range, the moldability will be poor, and the resulting fastener will be sticky and sticky, and will have low strength when expanded.On the other hand, if it is more than the above range, Water-stopping materials have poor low-temperature expansion properties and high hardness, making them difficult to work with.

Examples of the superabsorbent resin used in the water-stopping material of the present invention include commercially available starch-polyacrylate-based superabsorbent resins, crosslinked polyacrylates obtained by reverse phase polymerization in organic solvents, and vinyl Examples include superabsorbent resins obtained by crosslinking reaction products of alcohol copolymers and maleic anhydride copolymers with basic substances. Among these, a,β-unsaturated compounds having one or two carboxyl groups or groups that can be converted to carboxyl groups in the molecule are used, especially considering the water absorbency and durability of the resulting fasteners. A superabsorbent resin obtained by crosslinking a polymer contained as a polymeric component using a crosslinking agent is suitable.

The superabsorbent resin desirably has a water absorption capacity of 50 to 1000 times, preferably 100 to 800 times, its own weight.

If the water absorption capacity is less than 50 times, the resulting retaining wood will have insufficient expansion properties, and if it is 1000 times greater, the strength upon expansion will be insufficient.

In the fastener of the present invention, the superabsorbent resin is added in an amount of 15 parts by weight based on 100 parts by weight of the water-insoluble polymer composition comprising a combination of chlorinated polyethylene and polyisobutylene.
It is used in a range of 100 parts by weight, preferably 20 to 60 parts by weight. If the quantity is less than 5 parts by weight, the resulting anchoring material will have poor low-temperature expansion properties, and if it exceeds 100 parts by weight, the expansion ratio will be too large, resulting in low strength and high hardness, resulting in poor workability. .

Next, one example of a preferred method for manufacturing the fastening lumber of the present invention will be described.First, predetermined amounts of chlorinated polyethylene, polyisobutylene, and superabsorbent resin are blended, and if necessary, stabilizers, ultraviolet absorbers, After adding additives such as lubricants, fillers, flame retardants, antistatic agents, foaming agents, antifungal agents, and colorants and thoroughly kneading them, the resulting mixture is extruded or press-molded. The water stop material is obtained.

The thus obtained fastening wood is JIS K6301
According to the spring type hardness test type A at a temperature of 2°C, the hardness (JIS hardness) is less than 65.
This is necessary from the viewpoint of low-temperature workability. Those with a hardness of 65 or more have extremely poor low temperature workability.

Effects of the Invention The water-swellable fastener of the present invention has excellent low-temperature expansion properties,
It also has good strength when expanded, has low hardness at low temperatures, and has excellent low-temperature workability.

Furthermore, since a vulcanization process is not required for mounting the water stop material, productivity is also good.

This water-stopping material is used to prevent water leakage by filling gaps such as shield segment joint surfaces, humid pipes and prefabricated culvert boxes, and pouring joints of concrete structures during civil engineering and construction work, for example. Used effectively. It can also be used as a water retaining material for agriculture, forestry, and horticulture.

EXAMPLES Next, the present invention will be explained in more detail by examples.
The present invention is not limited to these examples in any way.

In addition, low-temperature expansion property, strength at room temperature expansion, and low-temperature workability were evaluated according to the following methods.

(1) After immersing a low-temperature expandable sample in still water at 2°C for 3 days, the weight expansion ratio (weight after immersion/weight before immersion) is determined, and the value is 2
．． 0 or more was evaluated as ○, and less than 2.0 was evaluated as ×.

(2) Strength at room temperature expansion The sample was immersed in still water at 18°C, and the tensile strength (kg/c shoulder 2) was determined when the expansion reached equilibrium, and the value was 1.5.
>&g/cm2 was evaluated as ◯, and less than 1.5Ag/eN was evaluated as ×.

(3) Low-temperature workability The hardness at a temperature of 2° C. was determined by the spring type hardness test type A test method according to JIS K6301, and the value less than 65 was evaluated as 0165 or more as ×.

Examples and Comparative Examples 1.5 parts by weight of a soot-based stabilizer (manufactured by Nitto Kasei Co., Ltd., TVS #8813) per 100 parts by weight of chlorinated polyethylene was added to a resin composition having the composition shown in the attached table, and chlorine. The total of polyethylene and polyisobutylene is 10
2.0 parts by weight of titanium oxide and 0.2 parts by weight of blue pigment [manufactured by Dainichiseika Kagyo Co., Ltd., PV 0171]
BLIJE) was added, and this mixture was kneaded with a roll heated to 120°C, and then press-molded at 140°C to create a water-stopping material sample with length and width of 20za+ and thickness of 21.

Each sample was evaluated for low temperature expansion properties, strength at room temperature expansion, and low temperature workability. The results are shown in the table.

The following superabsorbent resins, chlorinated polyethylene, and polyisobutylene were used.

To super absorbent resin Maleic anhydride/isobutylene copolymer [manufactured by Kuraray Soprene Chemical Co., Ltd., Kuraray Kl Gel 201,
Maximum water absorption: 200 times its own weight] B: Acrylic acid/vinyl alcohol copolymer [manufactured by Kaito Kagaku Kogyo Co., Ltd., Sumikagel 5P-520, maximum water absorption: 600 times its own weight] Chlorinated polyethylene 8: Chlorine content 35% by weight, specific gravity 1.15, hardness (Shore A) 55 [Osaka Soda Co., Ltd., Guisolac R^-
135] B: Chlorine content 35% by weight, specific gravity 1.16, hardness (Shore A) 70 (manufactured by Osaka Soda Co., Ltd., Guisorac C-2
35) Polyisobutylene

Claims (1)

[Claims] 1 (A) 100 parts by weight of a water-insoluble polymer composition consisting of 30 to 95% by weight of chlorinated polyethylene and 70 to 5% by weight of polyisobutylene, and (B) a polymer composition having a water absorption capacity of 50 to 1000 times its own weight. 1. A water-swellable waterproofing material, characterized in that it is formed by molding a mixture containing 15 to 100 parts by weight of a water-absorbing resin, and has a hardness of less than 65 at a temperature of 2°C.