JPH09208752A - Water-swelling rubber composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water-swelling rubber composition containing a ketiminized polyamide resin, a glycidyl etherified compound, a water-absorbing resin and a rubber as essential components, having high swelling ratio, keeping the shape over a long period even in a state swollen with water, having excellent stability and useful for water-stopping material, etc. SOLUTION: The composition contains (A) a ketiminized polyamide resin derived from (i) a polyamide resin derived from a polymerized fatty acid and a polyalkylene polyamine and (ii) a 5-7C ketone and having 95-100% conversion of the primary amino group of the component A to ketimine, (B) a glycidyl etherified compound produced by glycidyl etherifying a polyether polyol produced by adding an alkylene oxide to a polyhydric alcohol or a polyether polyamine produced by adding an alkylene oxide to a polyamine, (C) a water- absorbing resin such as a crosslinked product of a neutralized polyacrylic acid and (D) a rubber such as natural rubber as essential constituent components.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-swellable rubber composition, and more particularly, a water-swellable rubber composition having a shape-retaining property for a long period of time in a state of absorbing water and swelling, particularly a water-swellable sealing material. It is about.

[0002]

2. Description of the Related Art Conventionally, as a water-swellable sealing material, a water-absorbing substance such as a cross-linked product of a neutralized polyacrylic acid, a cross-linked product of a starch-acrylic acid graft copolymer, a cross-linked carboxymethyl cellulose salt, or polyvinyl alcohol is used as a rubber. Those which are added to the above to give water swelling property are used.

[0003]

However, these water-swellable sealing materials have a small swelling rate and are inferior in water stopping performance, and those having a large swelling rate are long-term storage due to deformation of the shape when swollen in water. It has a problem of insufficient formability.

[0004]

Means for Solving the Problems As a result of various investigations, the present inventors have conducted various investigations to solve the above problems in order to obtain a water-swellable rubber having a good shape-retaining property for a long period in a state of absorbing water and swelling. Has reached the present invention. That is, the present invention is a water-swellable rubber composition characterized by containing a ketiminated polyamide resin (A), a glycidyl ether compound (B), a water-absorbent resin (C) and rubbers (D) as essential constituents. It is a thing.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION As the ketiminated polyamide resin (A) used in the present invention, a polyamide resin (a) derived from a polymerized fatty acid (a) and a polyalkylene polyamine (b), and a carbon number of 5 It is derived from the ketones (b) of 7.

The polymerized fatty acid (a) of the present invention contains a large amount of unsaturated fatty acids such as linoleic acid and oleic acid derived from natural tall oil fatty acid, soybean oil, safflower oil, rice husk oil, cottonseed oil and the like. Examples thereof include those containing a dibasic acid as a main component, which is obtained by heating a fatty acid in the absence of a catalyst or a catalyst such as activated clay and alumina silicate. Further, as the polyalkylene polyamine (b),
Examples thereof include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and pentaethylenehexamine.

The polyamide resin (a) of the present invention is derived from the above-mentioned polymerized fatty acid (a) and polyalkylene polyamine (b), and the primary amine value is usually 10-18.
It is 0, preferably 20 to 150. Primary amine value is 1
When it is less than 0, the primary amino group regenerated by contacting water with the ketiminated polyamide resin (A) obtained by further reacting this polyamide resin with ketones does not sufficiently react with the glycidyl ether compound (B). Therefore, it is not sufficient to prevent the deformation of the shape when swollen with water. Also, the primary amine value is 180
When it exceeds, the reaction with the glycidyl ether compound (B) proceeds rapidly when the water-swellable rubber composition comes into contact with water, and the swelling ratio becomes low.

The ketones (b) of the present invention have 5 to 5 carbon atoms.
Examples of the ketone of 7 include diethyl ketone, methyl propyl ketone, methyl butyl ketone, methyl isobutyl ketone, ethyl butyl ketone, dipropyl ketone, methyl amyl ketone, diacetone alcohol, cyclohexanone and methylcyclohexanone. Preferred is methyl isobutyl ketone.

The conversion rate of primary amino groups of ketiminated polyamide resin (A) to ketimine is preferably 95 to 100%. If the conversion to ketimine is less than 95%, the glycidyl ether compound reacts with the amine remaining in the ketiminated polyamide resin even in the absence of moisture to form an epoxy resin, which is a rubber or water absorbent resin. The water-swelling rubber composition tends to have irregularities on its surface.

The total amine equivalent of the ketiminated polyamide resin (A) is usually 150 to 300, preferably 180 to 25.
0. If it is less than 150, the resin becomes too hard and the swelling ratio of the water-swellable rubber composition is lowered. If it exceeds 300, the desired shape-retaining property of the water-swellable rubber upon absorption of water cannot be obtained.

The glycidyl ether compound (B) used in the present invention is a compound obtained by glycidyl etherification of a polyether polyol (c) obtained by adding an alkylene oxide to a polyhydric alcohol such as propylene glycol, bisphenol A and glycerin sorbitol. , A compound obtained by glycidyl etherification of a polyether polyamine (d) obtained by adding an alkylene oxide to a polyamine such as ethylenediamine and diethylenetriamine. Preferred (B) is a glycidyl ether compound of a propylene oxide adduct of propylene glycol (polyoxypropylene glycol).

The epoxy equivalent of the glycidyl ether compound (B) is usually 200 to 450, preferably 250 to 35.
0. If it is less than 200, the resin is hard and the rubber is easily cracked. When it exceeds 450, it is difficult to obtain the desired shape-retaining property of the water-swellable rubber when absorbing water.

As the water absorbent resin (C) used in the present invention, a cross-linked product of a polyacrylic acid neutralized product, a self-crosslinking polyacrylic acid neutralized product, a starch-acrylic acid graft copolymer cross-linked product, and a starch. -Hydrolysate of crosslinked acrylonitrile graft polymer, saponified product of vinyl acetate-acrylic acid ester copolymer, crosslinked product of acrylate-acrylamide copolymer, acrylic acid-2-acrylamide-2
Examples include crosslinked products of methylpropanesulfonic acid copolymer salts, crosslinked products of isobutylene-maleic anhydride copolymer salts, crosslinked carboxymethylcellulose salts, etc., which are selected depending on the use and purpose.

Examples of the rubbers (D) used in the present invention include natural rubber, synthetic rubber, regenerated rubber and elastomer. Specifically, natural rubber, styrene-butadiene rubber, isoprene rubber, acrylonitrile-butadiene rubber, chloroprene rubber, ethylene propylene terpolymer, butyl rubber and recycled rubber thereof, ethylene-vinyl acetate thermoplastic elastomer, styrene-isoprene-styrene. , Styrene-butadiene-styrene, polybutadiene and the like, which are selected depending on the use and purpose.

The contents of the ketiminated polyamide resin (A) and the glycidyl ether compound (B) are 100 parts by weight of the total amount of the water absorbent resin (C) and the rubber (D).
The total amount of (A) and (B) is usually 3 to 20 parts by weight, preferably 5 to 15 parts by weight. When the amount is less than 3 parts by weight, the shape retention of the water-swellable rubber composition is not sufficient when absorbing water. 20
If the amount is more than parts by weight, the surface of the water-swellable rubber composition becomes too hard when absorbing water, and the swelling rate decreases.

The weight ratio of (A) and (B) is usually (A).
/ (B) = 30/70 to 70/30, preferably (A)
/ (B) = 40/60 to 60/40. When the amount of (A) is less than 30 parts by weight, the unreacted glycidyl ether compound causes bleeding from the surface of the water-swelling rubber composition when absorbing water, and when it exceeds 70 parts by weight, water formed after kneading is used. Irregularities occur on the surface of the swollen rubber composition.

The weight ratio of (C) and (D) is usually (C).
/ (D) = 10/90 to 30/70, preferably (A)
/ (B) = 15/85 to 25/75. When the amount of (C) is less than 10 parts by weight, the water absorption capacity is insufficient and the swelling does not occur. If the amount exceeds 30 parts by weight, the shape swelling cannot be obtained due to excessive swelling.

The water-swellable rubber composition of the present invention comprises (A),
The constituent components of (B), (C) and (D) are kneaded using a usual rubber kneading machine such as a roll, a kneader, a Banbury mixer, an intermix, and a calendar roll,
It is molded by an extrusion molding machine or a press molding machine. The water-swellable rubber composition of the present invention has a shape-retaining property for a long time even in an unvulcanized product, but in order to further improve the physical properties of the molded product, a crosslinking agent for causing intermolecular crosslinking is added. You may.

The cross-linking agent used in the present invention is a substance that forms a cross-linkage bond between each molecule of the water-absorbent resin and rubber, and includes sulfur, sulfur chloride, organic peroxides, organic sulfur compounds, and metal oxides. Compounds, rubber vulcanizing agents such as alkylphenol resins, polythiol compounds, azo compounds and the like can be used. Sulfur and organic peroxide crosslinking agents are preferred.

The water-swellable rubber composition of the present invention is usually manufactured as follows. Water absorbent resin (C) on rubbers (D)
And (C) at the same time or after the addition of (C), the ketiminated polyamide resin (A) and the glycidyl ether compound (B) are added, and if necessary, a filler, a softening agent, a plasticizer, and tackifier. A usual compounding agent for rubber such as an agent, a reinforcing agent, an antiaging agent, and a stabilizer is added, and kneading is performed using a calender roll, a kneader, a Banbury mixer, an intermix and the like. Then, it is made into a sheet by calender rolls, or a bridging agent such as a vulcanizing agent or a vulcanization accelerator is added, followed by press molding, or after extrusion, vulcanization treatment is usually performed at 100 ° C or higher to swell in water. A molded product of the rubber is obtained. The vulcanization treatment is not limited to thermal vulcanization, steam vulcanization, and hot air vulcanization, and natural vulcanization and hot water vulcanization may be used. In addition, it is preferable to apply a pressure-sensitive adhesive or a coating agent to the surface of the thus obtained molded product according to the purpose of use.

[0021]

EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited thereto. In the following,% indicates% by weight. Examples 1 to 5 and Comparative Examples 1 and 2 Mixtures (units are parts by weight) shown in Table 1 were kneaded by an intermix to prepare blended products 1 to 5 of the present invention and comparative blended products 6 and 7 (ketiminized polyamide). Resin and content of glycidyl ether compound are out of the range).

[0022]

[Table 1]

1) Cross-linked product of neutralized modified polyacrylic acid sodium 2) Naphthenic oil 3) Sanyo Chemical Co., Ltd .: Chemiox KC-502 (conversion rate 97.0%, total amine equivalent 260) 4) Sanyo Chemical Industry Product: Glycier PP-300P (epoxy equivalent 296) 5) Dibenzothiazyl disulfide 6) Tetramethylthiuram monosulfide 7) 2-Mercaptoimidazoline

These compounded products 1 to 4, 6 and 7 were rolled by a calender roll to obtain a sheet having a thickness of 3 mm.
Further, the blended product 5 was pressed at 135 ° C. for 11 minutes to obtain a sheet having a thickness of 3 mm. Tensile tests (JIS K 6301) were performed on these sheets, and the swelling ratios during immersion in water and immersion in warm water were measured. Table 2 shows the results.

[0025]

[Table 2]

1) Swelling rate when immersed in water: Weight change rate of test piece when immersed in tap water for 21 days 2) Swelling rate when immersed in hot water: Test piece when immersed in tap water at 70 ° C. for 7 days Change in weight x: Shape is lost after 1 day, measurement is not possible 3) Shape retention after immersion in water: Shape retention of test piece when immersed in tap water for 28 days ◯: Good Δ: Partially collapsed x : Deformation on the whole 4) Shape retention when immersed in warm water: Shape retention of test piece when immersed in tap water at 70 ° C for 28 days ○: Good △: Deformation on part ×: Deformation on the whole

[0027]

INDUSTRIAL APPLICABILITY The water-swellable rubber composition of the present invention forms a skeleton (matrix) of a hydraulic substance by a crosslinking reaction between a ketiminated polyamide resin and a glycidyl ether compound when absorbing water. It does not lose its shape-retaining property, and a product having a large swelling rate can be obtained. Further, the stability in water is good, and the swelling rate is not significantly reduced. Therefore,
The water-swelling rubber of the present invention can be used in a wide range of applications such as a waterproof material and a packing material.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location C08L 77/08 LQR C08L 77/08 LQR C09K 3/10 C09K 3/10 Z (72) Inventor Sekine Mihiro 2-5-24 Atago, Kazo-shi, Saitama Prefecture Saitama Gomu Kogyo Co., Ltd. (72) Inventor Sadakatsu Yasui 1-11, Hitotsubashi-honcho, Higashiyama-ku, Kyoto Sanyo Chemical Industry Co., Ltd. (72) Inventor Tatsuo Asano Sanyo Kasei Kogyo Co., Ltd., 1-11, Hitotsubashi-honcho, Higashiyama-ku, Kyoto

Claims (3)

[Claims] 1. A water-swellable rubber composition comprising a ketiminated polyamide resin (A), a glycidyl ether compound (B), a water-absorbent resin (C) and rubbers (D) as essential constituents. . 2. The ketiminated polyamide resin (A),
Polyamide resin (a) derived from polymerized fatty acid (a) and polyalkylene polyamine (b) and ketone (b) having 5 to 7 carbon atoms, and (A) primary amino group of ketimine The water-swellable rubber composition according to claim 1, wherein the conversion rate is 95 to 100%. 3. The glycidyl ether compound (B) is obtained by glycidyl etherifying a polyether polyol (c) obtained by adding an alkylene oxide to a polyhydric alcohol or a polyether polyamine (d) obtained by adding an alkylene oxide to a polyamine. The water-swellable rubber composition according to claim 1 or 2.