JPH0676514B2 - Water-swellable composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a water-swellable composition. Specifically, the present invention is
The present invention relates to a water-swellable composition containing polyvinyl chloride (PVC) or ethylene vinyl acetate copolymer (EVA).

[Conventional technology and problems]

PVC is one of the most widely used plastics today due to its excellent mechanical properties and low price.
A composition obtained by blending PVC with a polyurethane resin is known in Japanese Patent Publication No. 53-29705, Japanese Patent Publication No. 58-46265, etc.
A composition that imparts water swelling property to PVC has not yet been known. EVA is also a thermoplastic resin that is excellent in flexibility and rubber elasticity and has excellent low-temperature characteristics, and its demand is expanding, but EVA with water swelling property is not known yet.

On the other hand, a water-swelling urethane resin is conventionally known as typically seen in JP-B-53-38750, and has been conventionally used as a sealing material or the like.

The present inventors have repeatedly studied to obtain water-swellable PVC and water-swellable EVA by blending PVC and EVA with a water-swellable urethane resin, but PVC, EVA and water-swellable urethane resin Compatibility and miscibility are extremely poor, and a composition that can withstand practical use is
It couldn't be easily obtained.

[Means for solving problems]

However, after various investigations, the present inventors have found that a uniform and stable composition can be obtained by adding nitrile butadiene rubber (NBR) as a third component when mixing PVC or EVA and a water-swelling urethane resin. The inventors have found out and completed the present invention.

That is, the present invention is a solid polyvinyl chloride or ethylene vinyl acetate copolymer 1-90 parts (weight ratio), nitrile butadiene rubber 1-90 parts (weight ratio) and water-swelling urethane resin 1-90 parts (weight ratio). Ratio).

For PVC and EVA used in the present invention, commercially available resins can be used as they are, and as NBR, ordinary ones can be used.

The water-swellable polyurethane resin used in the present invention is particularly preferably in the form of a paste, and as such a paste-like water-swellable polyurethane resin, a reaction between a water-swellable polyurethane prepolymer having a terminal isocyanate group and water and / or a curing agent is performed. There is a resin obtained by

The terminal isocyanate group-containing water-swellable polyurethane prepolymer is, for example, propylene oxide / ethylene obtained by reacting ethylene oxide / propylene oxide random / block-polymerized polyoxyalkylene glycol having a hydroxyl equivalent of 400 to 6000 with an organic diisocyanate by a conventional method. Prepolymers having an oxide ratio of 7/3 to 0/10 can be mentioned.

The prepolymer can be partially cured by a conventional method with a curing agent such as water or an amine type or a polyol type to be a paste-state water-swellable polyurethane resin. The curing may be performed by using water and a curing agent together. As a curing agent, 4,4'-methylene-bis-2-chloroaniline, 1,4
-Butanediol, hydroquinone-bis- (β-hydroxy) ether, resorcinol-bis- (β-hydroxy) ether, 1,2-bis- (2-aminophenolthio) ethane, trimethylene glycol di-p-amino Benzoate and the like can be used alone or in combination.

In the water-swellable composition of the present invention, the compounding ratio of PVC or PVA and NBR and the water-swellable polyurethane resin can be widely varied, and PVC or PVA 1 to 90 parts, NBR 1 to 90 parts, and water swellable polyurethane resin. It can be freely mixed within the range of 1 to 90 parts.

Further, the water-swelling composition of the present invention may further contain what is usually called a water-absorbent resin.

As what is usually called a water-absorbent resin here, a carboxyl group, a carboxylate salt, a carboxylic acid amide, a carboxylic acid imide, a carboxyl group such as a carboxylic acid anhydride or a group that can be induced into a carboxyl group in the molecule. Those containing one or two α, β-unsaturated compounds as a main component, and optionally other α, β-unsaturated compounds added and polymerized, or those further modified with isocyanates or the like can give.

Examples of such a water-absorbent resin include starch / acrylic acid graft copolymers, salts of styrene-maleic anhydride copolymers, cross-linked products of sodium polyacrylate, cross-linked products of polyvinyl alcohol / maleic anhydride reactants, vinyls. Known superabsorbent polymers such as saponified products of ester / ethylenically unsaturated carboxylic acid or its derivative can be used.

Such a water-absorbent resin is preferably added within the range of 2 to 30% in the water-swellable composition of the present invention, and by further adding such a water-absorbent resin, the water absorption rate and the water absorption rate can be easily adjusted. The merit of being able to do is obtained.

The water-swellable composition of the present invention is thermoplastic, but when it contains a large amount of NBR, it can be vulcanized by adding substances such as a vulcanizing agent and a crosslinking agent.

As such substances, sulfur, chlorine chloride, organic peroxides, organic sulfur compounds, metal oxides, rubber vulcanizing agents such as alkylphenol resins, polythiol compounds, polyamine compounds, azo compounds and the like can be used. Crosslinking with sulfur and organic peroxides is particularly preferred.

Sulfur is preferably powdered sulfur, and suitable organic peroxides include benzoyl peroxide, dicumyl peroxide, methyl ethyl ketone peroxide, lauryl peroxide, cyclohexanone peroxide, t-butyl perbenzoate, t-butyl hydroperoxide, t. −
Examples include butylbenzene peroxide, cumene hydroperoxide and t-butyl peroctoate.

Suitable organic sulfur compounds include tetramethylthiuram disulfide (TT), N, N'-dithiobismorpholine and the like.

Suitable metal oxides include zinc white, magnesia, litharge and the like.

Suitable alkylphenol resins include alkylphenol formaldehyde resins containing 7-10% methylol groups.

Suitable polythiol compounds include trimethylolpropane trithioglycolate, trimethylolpropane tri (3-mercaptopropionate), glycol dimercaptopropionate, glycol dimercaptoacetate, pentaerythritol tetra (3-mercaptopropionate). ), Pentaerythritol tetrathioglycolate, dipentaerythritol hexa (3-mercaptopropionate), and the like.

Suitable polyamine compounds include aldehyde-amine condensates, guanidines and the like.

Suitable azo compounds include azobisisoptyronitrile, 2-t-butylazo-2-cyano-4-methylpentane, 4-t-butylazo-4-cyano-valeric acid and the like.

Furthermore, in the present invention, if necessary, tar, asphalt, animal and vegetable oils and fats, aliphatic polybasic acid esters,
An appropriate amount of a plasticizer such as DOP or DBP, a filler such as calcium carbonate, talc, clay, titanium dioxide or the like, a coloring agent, and an antioxidant may be contained.

The water-swellable composition of the present invention is obtained by appropriately mixing the above-mentioned components and kneading them using a kneading roll, a Banbury mixer or the like. A molded product can be obtained by molding or vulcanizing it as it is.

The water-swellable composition of the present invention is PVC or EVA to which an appropriate water-swelling property is imparted, and the water-swelling rate thereof is about 10 to.
100%. Since the composition has water absorbency, moisture permeability, air permeability, thermoplasticity or vulcanizability, and has good moldability (injection extrusion, injection, calender molding are possible), the film, the yarn, A wide variety of molded products such as foams and molds can be manufactured, and these molded products can be applied to applications such as zipper check, seals, packing, agricultural films, and packaging materials (especially for blue products).

〔Example〕

 Hereinafter, the present invention will be described in more detail with reference to Examples.

[Production of paste-like water-swellable polyurethane resin]

40% MOCA in 50 parts of a urethane prepolymer obtained by the reaction of 1 mol of a polyether obtained by adding ethylene oxide and propylene oxide to propylene glycol and having an average molecular weight of 5000 and 78% of ethylene oxide group and 3.0 mol of TDI.
Five parts were reacted at 40 ° C. to obtain a 6000 cps paste urethane resin at the same temperature, which was used.

Example 1 Commercially available PVC (Neon Zeon Geon 103EP) and NBR (Neon Zeon Nipol 1041 acrylonitrile content 41%) 1 each
00 parts by weight and 200 water-swelling urethane resin produced above
A part by weight was kneaded at 120 to 140 ° C. using a roll to prepare a plate-shaped press sheet.

The water swelling ratio of this product was 76% after immersion in water for 7 days, and the water vapor permeability was 1400 (g / m ² · 24 hr).

Example 2 50 parts by weight of commercially available PVC (Geon 103EP manufactured by Zeon Corporation), NBR
(Nihon Zeon Nipol DN204 acrylonitrile content 33
%) 20 parts by weight, DOP plasticizer 50 parts by weight, and 20 parts by weight of the water-swelling urethane resin produced above were kneaded at 120 ° C. using a roll to prepare a film having the following thickness.

The water swelling ratio (immersion in water for 7 days) is as follows: Film thickness (mm) Water swelling ratio (%) 1.0 10 0.5 16 0.25 25 0.10 35 Example 3 EVA (Toyo Soda Ultrasen 750 vinyl acetate 32%) ) NBR
(Nippon Zeon Nipol1042 acrylonitrile content 33%)
And the above water-swellable urethane resin was kneaded in the following composition at 100 to 120 ° C. using a roll. These water swelling rates (immersion in water for 7 days) are as follows: EVA 100 parts by weight 100 parts by weight NBR 40 5 Water swelling urethane 100 40 Water swelling rate 76% 18% Example 4 EVA (Toyo Soda Ultrasen 720 acetic acid) Vinyl 28%) 50 parts by weight, NBR (Nipol1042) 100 parts by weight, zinc white 5.0 parts by weight,
Stearic acid 1.0 part by weight SRF carbon black 40 parts by weight,
70 parts by weight of urethane resin was kneaded using a roll at 100 to 120 ° C. After that, 1.25 parts by weight of sulfur and 0.30 part by weight of accelerator TS were added and kneaded with a roll, followed by press vulcanization at 150 ° C. for 60 minutes with a 2 × 200 × 200 m / m press plate. The water swelling ratio (7 days) of this product was 43%.

Example 5 A press sheet was prepared in the same manner as in Example 1 except that the same components as in Example 1 were used and the compounding ratio of the water-swellable polyurethane resin was changed, and the water swelling ratio was measured. It was the result.

Example 6 Using the same components as in Example 1 above, a press sheet was prepared in the same manner as in Example 1 while changing the NBR compounding ratio, and the water swelling ratio was measured. The results were as follows. .

Example 7 Using the same components as in Example 1 above, a press sheet was prepared in the same manner as in Example 1 except that the compounding ratio of PVC was changed, and the water swelling ratio was measured. The results were as follows. .

Example 8 Commercial PVC (Neon Zeon Geon 103EP) and NBR (Nihon Zeon Nipol 1041 acrylonitrile content 41%) 1 each
00 parts by weight and 50 parts by weight of the paste-like water-swelling polyurethane resin produced as described above were kneaded at 120 to 140 ° C. using a roll to prepare a plate-shaped press sheet.

The water swelling ratio of this product was 30% after immersion in water for 7 days, the tensile strength was 118 kgf / cm ² , and the elongation was 385%.

Comparative Example 1 A plate-like press sheet was prepared in the same manner as in Example 8 except that PVC latex (Geon Latex 151 manufactured by Nippon Zeon, solid content: 52%) was used instead of PVC (Geon 103EP manufactured by Nippon Zeon).

The water swelling ratio of this product was 28% after immersion in water for 7 days, the tensile strength was 75 kgf / cm ² , and the elongation was 263%.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yasumasa Hayashida 7-35 Higashiohisa, Arakawa-ku, Tokyo 7-35 Asahi Denka Kogyo Co., Ltd. (56) Reference JP-A-47-1484 (JP, A) JP Showa 57-23618 (JP, A)

Claims (1)

[Claims] 1. Solid polyvinyl chloride or ethylene vinyl acetate copolymer 1-90 parts (weight ratio), nitrile-butadiene rubber 1-90 parts (weight ratio) and water-swelling urethane resin 1
A water-swellable composition consisting of ˜90 parts (weight ratio).