JPH0393878A - Water-swelling water-sealing material and preparation thereof - Google Patents

Abstract

PURPOSE:To profitably prepare the subject material having excellent durability and swelling stability by vulcanizing a composition containing a sulfur-modified chloroprene, a filler and a specific reactive crosslinked product. CONSTITUTION:(A) 100 pts.wt. of a sulfur-modified chloroprene rubber, (B) 40-150 pts.wt. of a filler such as carbon black, (C) a water-swelling polyurethane crosslinked product prepared by reacting (i) 40-250 pts.wt. of a polyoxyalkylene glycol containing 50-90wt.% of oxyethylene units with (ii) an isocyanate component comprising a diisocyanate and a tri- or more-functional polyisocyanate in an NCO:OH of 1.1:1-3.0:1, and, if necessary, a stabilizer, a plasticizer, etc., to provide a composition. The composition is mixed with a vulcanizing agent such as sulfur and a vulcanization-arrelerating agent and subsequently molded into the objective material.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a water-swellable water-stopping material button and its production. More specifically, the water-swellable composition has excellent moldability, particularly extrusion moldability, and the composition obtained by molding and vulcanizing the composition has excellent durability and swells well even in electrolyte aqueous solutions. This invention relates to a water-swellable water-stopping material that has excellent water-stopping properties, exhibits extremely low extractables due to long-term immersion in water, etc., and can be produced industrially advantageously, and a method for producing the same. It is something.

[Conventional technology]

Many water-swellable water-stopping materials have been proposed in the past, in which superabsorbent resins are dispersed in resins or elastomers. However, since the superabsorbent resins commonly used in the past are based on polymer electrolytes, they have had the disadvantage that the degree of swelling in electrolyte aqueous solutions such as seawater is significantly lower than in fresh water.

On the other hand, in order to solve these drawbacks, water-stopping materials using nonionic water-swellable urethane resins have been proposed. For example, water-swellable substances made by blending water-swellable urethane resin with rubber and curing them (Japanese Unexamined Patent Application Publications No. 57-26654, JP-A No. 57-11972), buttons and soft resins or rubbers with high Water-absorbing and water-retaining material containing water-absorbing anti-lipid and water-swellable urethane prebolymer
120655), etc. have been reported.

With these methods, water-swellable rubber-based water-stopping materials whose degree of swelling in an electrolyte aqueous solution is similar to that in water can be obtained. Therefore, the manufacturing process is
It is necessary to carry out the reaction in two steps: combining a water-swellable urethane prepolymer, mixing the prepolymer with rubber, and curing the mixture by adding a hardening agent such as a polyol or polyamine to the mixture. Yes, it has become complicated! It had some drawbacks.

However, in the curing reaction VCh, if the crosslinking degree of the water-swellable polyurethane crosslinked product is low, the urethane prepolymer with a low degree of crosslinking will be extracted by long-term immersion in water, etc., and the durability and swelling stability will decrease. death! Therefore, it is necessary to increase the degree of crosslinking of water-swellable polyurethane. However, increasing the degree of crosslinking of water-swellable polyurethane significantly reduces its moldability, especially in systems where extrusion moldability must be ensured. This has been a major obstacle in obtaining water-swellable water-stopping materials with low extraction rates.

[Problem to be solved by the invention]

The present invention has been made to improve these conventional drawbacks. In other words, a water-swellable composition with excellent moldability, especially extrusion properties, and a water-swellable composition obtained by vulcanizing the composition, which has excellent durability and swelling stability, and also has good swelling properties against electrolyte water dissolution. It is an object of the present invention to provide a water-swellable water-stopping material P which has the following properties and can be produced industrially advantageously, and a method for producing the same.

[Means to solve the problem]

As a result of various studies, the inventors used sulfur-modified chloroprene rubber as an elastomer, which has high mechanical dissolubility and a large decrease in viscosity due to mastication, and added a filler button to this sulfur-modified chloroprene rubber. and polyoxyalkylene glycol are mixed uniformly, and an isocyanate consisting of zoisocyane}D and a trifunctional or higher functional polyisocyanate is added, and the reaction is carried out to form a rubber compound without using a urethane prepolymer or a curing agent. A water-swellable composition obtained by producing a water-swellable polyurethane crosslinked product consisting of a one-step reaction product of polyoxyalkylene glycol and an isocyanate, and then adding a vulcanizing agent etc. has excellent moldability, especially extrusion molding. It has been found that even if the degree of crosslinking of water-swellable urethane is increased, good extrudability can be obtained. The water-swellable water stop material 0#+ obtained by molding and vulcanizing them has good durability and swelling stability, and has an extremely low extraction rate due to long-term immersion in water. The present invention has been completed by discovering that an excellent water-swellable water-stopping material can be provided industrially advantageously.

That is, the first invention of the present invention uses sulfur-modified chloroprene rubber as an elastomer, filler, and polyoxyalkylene glycol containing 50 to 90% by weight of oxyethylene units, zoisocyanate, and trifunctional or higher functional polyisocyanate. This is a water-swellable water-stop material characterized by being made by vulcanizing a composition containing a reaction crosslinked product with

Further, the second invention provides an isocyanate consisting of a diisocyanate and a trifunctional or higher-functional polyisocyanate after mixing sulfur-modified chloroprene rubber, filler P, and polyoxyalkylene glycol containing 50 to 90% by weight of oxyethylene units. to the hydroxyl group of polyoxyalkylene glycol: ○H=1.1:1-5.0
: After adding and reacting in an amount in the range of 1 to form a crosslinked product consisting of the polyoxyalkylene glycol and isocyanate, adding a vulcanizing agent, and then vulcanizing the resulting composition after molding. A method for producing a water-swellable water-stopping material characterized by:

The present invention will be explained in detail below.

The basic composition of the water-swellable waterproof material of the present invention is sulfur-modified chloroprene rubber, filler. and vulcanizing a composition containing a crosslinked product obtained by reacting a polyoxyalkylene glycol containing 5 to 9 ffl% oxyethylene units with an isocyanate consisting of a diisocyanate and a trifunctional or higher functional polyisocyanate. It is characterized by the fact that

Next, each of the above-mentioned formulations and their proportions will be explained.

In the present invention, the filler used may be any filler that is commonly used in sulfur-modified chloroprene rubber, such as carbon black, silica filler,
Examples include calcium carbonate, Merck, clay titanium oxide, etc. Among these, carbon delac and silica fillers are mainly used. A casing, an anti-aging agent, a stabilizer, a plasticizer, a plasticizing agent, etc. can also be added as part of the filler.

The amount of filler added varies depending on the required characteristics of the water-swellable water-stopping material that is the object of the present invention, but is usually 40 to 150 parts, preferably 50 parts per 100 parts of sulfur-modified chloroprene rubber. ~The 120-year long yearning club is desirable. If it is less than 40 parts by weight, the strength of the water-swellable water-stopping material will be insufficient, and if it exceeds 150 parts by weight, the hardness of the water-swellable water-stopping material will be too high and the elongation will be reduced, which is not desirable.

The polyoxyalkylene glycol used in the present invention is a polymer containing hydroxyl groups at both ends obtained by cycloaddition polymerization of alkylene oxide using ethylene glycol as a starting material. The polyoxyalkylene glycol has 50 to 90 oxyethylene units.
If the weight is high and the case is good, one containing 6 to 80 weight f% is desirable! Yes.

Examples of other oxyalkylene units include oxyzolobylene and oxybutylene, and oxypropylene units are preferably used. If the oxyethylene unit content is less than 50% by weight, the swelling degree of the water-swellable water-stopping material obtained will be insufficient, and if it exceeds 90% by weight, the swelling degree of the water-swellable waterstopping material will decrease over time due to crystallization of the oxyethylene units. It's good because it increases the target! It's not right. The molecular weight of the polyoxyalkylene glycol used is usually 10% due to swelling degree and ease of handling.
A value in the range of 00 to 6,000, preferably 2,000 to 5,000 is preferably used.

The amount of polyoxyalkylene glycol used is 100% of sulfur-modified chloroprene rubber! I want 40 to 250 parts by weight, preferably 5 to 200 parts by weight! Yes. If it is less than 40 parts by weight, the swelling degree of the resulting water-swellable water-stopping material will be small, and if it exceeds 250 parts by weight, it will be difficult to uniformly disperse the polyoxyalkylene glycol in the sulfur-modified chloroprene rubber compound, so it is preferable. do not have.

In the present invention, an isocyanate consisting of zoisocyanate and a polyisocyanate with higher functionality is used. Examples of the isocyanate include trifunctional or higher functional polyisocyanates, such as triphenylmethane triisocyanate, tris(p-isocyanate phenyl) thiophosphite, polymethylene polyphenyl isocyanate, and diisocyanates, such as toluylenezoisocyanate. Examples include the use in combination with 1-1 diisocyanate, naphthylene-1,5-diisocyanate, 1-toluidine diisocyanate, zophenylmethane diisocyanate, and the like. 1.So-called crude MDI modified with diphenylmethane diisocyanate (containing approximately 50% by weight of zoisocyanate and approximately 50% by weight of trifunctional or higher polyisocyanate, average NCO group = approximately 5) are also mentioned as examples of isocyanates.

As the isocyanate used in the present invention, crude MDIt or a combination of crude MDI and zophenylmethane zoisocyanate can be particularly preferably used from the viewpoint of safety and ease of handling.

In the present invention, polyoxyalkylene glycol and isocyanate react to produce a crosslinked product (hereinafter referred to as water-swellable polyurethane crosslinked product), but the production of the water-swellable polyurethane crosslinked product is a urethane prepolymer. It is carried out in one step reaction without using. The structure of the water-swellable crosslinked polyurethane consists of branching and crosslinking at trifunctional or higher functional polyisocyanate moieties.

! In addition, the content of trifunctional or higher-functionality polyisocyanate in the isocyanate is preferably in the range of 10 to 50% by weight of the isocyanate. If the weight is less than 10% by weight, the degree of crosslinking of the water-swellable crosslinked polyurethane obtained is too low and the swelling stability decreases, and if it exceeds 50% by weight, the degree of crosslinking of the water-swellable crosslinked polyurethane is too high and the degree of swelling is reduced. Undesirable.

In addition, the amount of isocyanate to be used should be determined based on the desired characteristics of the water-wettable water-stopping material and the amount of the mixture used during the urethane production reaction in which polyoxyalkylene glycol and isocyanate react to produce a water-swellable cross-linked polyurethane. Although it varies depending on the amount of water present in the polyoxyalkylene glycol, NCO:OH=1 for the hydroxyl group of polyoxyalkylene glycol.
．． 1: 1~5.0: 1, Haotong or 1.1 5
: 1 to 2.2 : Used in the range of i. 1.1
: If it is less than 1, the urethane production reaction will not proceed sufficiently, and unreacted polyoxyalkylene glycol will remain.
If it exceeds 5.0:1, the allophanate reaction will increase due to excess polyisocyanate, resulting in a high degree of crosslinking of the water-swellable polyurethane crosslinked product. I hope it's the cause! Not good.

When molding the composition containing the sulfur-modified chloroprene rubber, the filler P, and the water-wettable polyurethane crosslinked product, the VC of the present invention has a hardening agent for the purpose of improving moldability, especially extrusion moldability. Either the peptizer or the plasticizer or both can be added. Examples of dehydrating agents include thiuram-based vulcanization accelerators, dithioate-based vulcanization accelerators, and guazonine-based vulcanization accelerators.Use these alone! or can be used together. Among these, PPD
(Pentamethylene dithiocarbamic acid piperidine salt) is preferably used. The amount added is preferably 0 to 40 parts by weight per 100 parts by weight of the sulfur-modified chloroprene rubber. shi<
is preferably 0 to 15 parts by weight. The plasticizer to be added may be one that is commonly used and blended into elastomers, and the additive amount is 0 to 80 parts by weight per 100 parts by weight of sulfur-modified chlorodelene rubber. ~50 Jushabu.

? In the invention, when vulcanizing a composition containing sulfur-modified chloroprene rubber, a filler, and a water-swellable polyurethane crosslinked product, a sulfur-modified chloroprene rubber curing agent, vulcanization accelerator, etc. are used. be able to.

As the vulcanizing agent, vulcanization accelerator, etc., the sulfur-modified
o A combination of vulcanizing agent and vulcanization accelerator that is compatible with the plain rubber may be used. For example, a vulcanizing agent such as sulfur, a sulfur compound 1 or a metal oxide such as zinc oxide, magnesium baride, or lysazo, and a vulcanization accelerator such as a guanizone system, a sulfenamide system, a thiuram system, a thiazole system, or a dithiocarbamate system. Agents can be used in combination. Organic peroxides can also be used as vulcanizing agents, but in this case no vulcanization accelerator is required. Examples of organic peroxides include:
Zokuruperoxide, 1,1-bis(t-butylperoxy)5,5,5-trimethylcyclohexane, n-
Examples include detyl-4,4'-bis(cybutylperoxy)valerate, 2,5-zomethyl-2,5-di(5-butylperoxy)hexane, and the like. The amounts of the vulcanizing agent, vulcanization accelerator, etc. to be used are those generally used in the vulcanization of ordinary sulfur-modified chloroprene rubber.

The production of the water-engravable water-stopping material according to the present invention is carried out by mixing, reacting, and vulcanizing the various ingredients described above. It is fine as long as it is possible. Examples include roll housing or internal mixers such as Banbury mixer kneaders and pressurized kneaders. Among these, a pressurized seconder is most preferably used in terms of safety and stability of the reaction.

Vulcanization can be carried out by any conventional method without particular limitation, such as hot pressure vulcanization, hot air vulcanization, etc.

1 of the water-swellable waterproof material of the present invention! ! To give a specific example of the manufacturing method, first, sulfur-modified chloroprene rubber is placed in the device and masticated, and then filler buttons and polyoxyalkylene glycol are added and mixed uniformly. Next, after adding a urethane raw material or a catalyst as necessary, an isocyanate consisting of zoisocyanate and a trifunctional or higher functional polyisocyanate is added, and the mixture is heated at a temperature of 40 to 125°C.
The entire reaction was carried out for 0 to 50 minutes to produce a water-swellable polyurethane crosslinked product consisting of a reaction product of polyoxyalkylene glycol and isocyanate, which also served as a vulcanizing agent and vulcanization accelerator for a substantial amount of sulfur-modified chlorodelene rubber. A water-swellable water-stopping material can be obtained by adding an agent, molding and vulcanization.

The present invention involves uniformly dispersing polyoxyalkylene glycol in a so-called sulfur-modified chloroprene rubber compound, which is made by uniformly mixing ω1t yellowed chloroprene rubber, filler material, and polyoxyalkylene glycol, and then adding diisocyanate and polyoxyalkylene glycol. Polyisocyanin with higher functionality
By adding and reacting an isocyanate consisting of the This water-swellable composition has excellent moldability, especially extrusion moldability, due to the reduced viscosity of the composition due to the decomposition properties of the sulfur-modified chloroprene rubber, which is an elastomer component.

The sulfur-modified chloroprene rubber compound uniformly containing the water-swellable polyurethane cross-linked product is vulcanized by adding a vulcanizing agent, whereby the sulfur-modified chloroprene rubber cross-linked product and the water-swellable polyurethane cross-linked product are mutually bonded. A structure that is intertwined with each other, the so-called IPN (interpenel, rating P)
A water-swellable water-stopping material with excellent swelling stability and excellent swelling stability can be obtained by using a composition in the form of a polymer (Nebwork).

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples in any way. Among them, the swelling ratio is 20 from the extruded or shaped vulcanized product.
Cut out an X2On square sample piece, immerse it in tap water and various electrolyte aqueous solutions at 23°C for 7 days, and then measure its weight.
It was calculated using the following formula.

The extraction rate was determined by the following formula by immersing in tap water at 25°C for 50 days, then drying at 105°C for 1 day using a gear open, measuring the weight.

Example 1 A 20-e pressurized seconder (Moriyama Manufacturing Co., Ltd.) was used with the formulation shown in the table.
D20-40 type) was used for mixing and reaction. First, sulfur-modified chloroprene rubber was masticated on a roll for 5 minutes, then put into a seconder and further masticated for 5 minutes.
Filler and poly(oxyethylene-oxy7° propylene) glycol [Random containing hydroxyl groups at both ends, obtained by addition polymerizing ethylene glycol with ethylene oxide and propylene oxide at a weight ratio of 90:10 by a conventional method. Copolymer molecular weight approximately 5000, OH group =
2] and mixed uniformly. After adding didetyl tin maleate as a urethane production catalyst, a polyisocyanate mixture (trade name MDI-CR200X) JDI-LT
Mixed polyisocyanate (both manufactured by Mitsui Toatsu Chemical Co., Ltd.) was added, and stirring was continued for 15 minutes at a temperature of 70° C. to obtain a reaction mixture. A vulcanizing agent was added to the resulting reaction mixture using a roll, and then a tape-shaped extrudate with a cross section of 5 mm x 20 mm was obtained using a vented rubber extruder with a screw diameter of 60 mm. The obtained extrudate was heated and vulcanized at 150° C. for 1 hour in an open gear. The surface condition, physical properties, swelling degree, and extraction rate of the obtained vulcanized tape are shown in the table.

Comparative Example 1 Using the formulation shown in the table, the same operation as in Example 1 was carried out to obtain a reacted raw material. After adding a vulcanizing agent to the obtained reaction product using a roll, a tape-shaped extrudate with a cross section of 5 runs x 2Q mx was obtained using a vented rubber extruder with 6 screw diameters. The obtained extrudate was heated at 150°C while the gear was open.
It was vulcanized by heating at ℃ for 1 hour.

The surface condition, physical properties, degree of swelling, and extraction rate of the obtained vulcanized tape are shown in the table, but the surface condition of the tape was poor and could not be put to practical use.

Comparative Example 2 A reaction product was obtained by carrying out the same operation as in Example 1 using the formulation shown in the table. A vulcanizing agent was added to the obtained reaction product using a roll, and then a tape-shaped extrudate of 3 mm x 20 mm was obtained using a vented rubber extruder with a screw diameter of 60 mm.

The obtained extrudate was heated and vulcanized at 150° C. for 1 hour in an open gear. The surface condition, physical properties, degree of swelling, and extraction rate of the obtained vulcanized tape are shown in the table.The extraction rate was high and the molded product had poor swelling stability.

EXAMPLE 2 Using the poly(oxyethylene-oxyzolopyrene) glycol used in Example 1 with the formulation shown in the table, the same mock-up was carried out to obtain a reaction product. After adding a plasticizing agent and a Wκ additive using the obtained reaction raw material roll, a tape-shaped extrudate with a cross section of 5 m x 20 was obtained using a vented rubber extruder with a screw diameter of 6 Q x m. . The resulting extrudate was vulcanized in T-gear ozone by heating at 150°C for 1 hour. The surface condition, physical properties, moisture content, and extraction rate of the obtained vulcanized tape are shown in the table.

Example 3 The same operation as in Example 1 was performed using the formulation shown in the table to obtain a reaction product. The obtained reaction product was treated with a plasticizer (
After adding the vulcanizing agent and the vulcanizing agent, use a vented rubber extrusion block with a screw diameter of 60 mm to make the cross section 5F + 3! A tape-shaped extrudate with a diameter of 2 times was obtained.

The resulting extrudate was vulcanized by heating in a gear oven at 150°C for 1 hour. The surface condition of the obtained vulcanized tape,
The physical properties, degree of swelling, and extraction rate are shown in the table.

1) Chloroprene rubber with yellowing properties: Trade name: Denkaku Kuchilosolene PM-40 (“i!t Ki Kagaku Kogyo Co., Ltd.)
2) Non-sulfur modified chloroderene rubber: Trade name: Denka Chloroprene M-40 (manufactured by T-Kikagaku Kogyo Co., Ltd.) 3
) Magnesium oxide: Product name, Kiyowa Mag 100 (manufactured by Kyowa Chemical Industry Co., Ltd.) 4) Anti-aging agent: Product name, Naugard 445 (manufactured by Uniroyal Co., Ltd.) 5) Product name, Seast SO (Manufactured by Tokai Carbon Co., Ltd.) 6) Wet process silica: Product name: Nip Seal VN-5 (
(manufactured by Nippon Silica Co., Ltd.) 7) Plasticizer: Product name, Polycyde W-1000 (manufactured by Dainippon Ink and Chemicals Co., Ltd.) 8) Catalyst: Product name, MARK BT-5 1 (manufactured by Adeka Argus Chemical Co., Ltd.) ) 9) Crude MDI: Product name, MDI-CR200 (
Mitsui Toatsu Chemical Co., Ltd., #) 10) Bifunctional M]M Nisho product name, MDI-L'l" (
Mitsui Toatsu Chemical Co., Ltd.) 11) Zinc oxide: Product name, Zinc No. 1 (Seido Chemical Co., Ltd.)
) 12) Vulcanizing agent: Trade name, Perhexa 5M (1.
1-bis(sheepylperoxy)+,3,5-trimethylcyclohexane) (NOF Corporation #15)
PPD (pentamethylene dithiocarbamate biperidine salt): Product name, Noxeler PPD (Ouchi Shinko Co., Ltd.)
[Effects of the Invention] As explained above, the water-swellable composition of the present invention has excellent molding processability, particularly extrusion moldability, and can be molded or molded.
The water-swellable waterproof material obtained by vulcanization has excellent water-swellability, and the degree of swelling in electrolyte aqueous solutions such as water is close to the degree of swelling in water, and it can be used for long periods of time. It is an extremely useful water-stopping material with very little extractable matter when immersed in water, excellent swelling stability, and durability.

In addition, conventional water-swellable polyurethane-containing elastomer compositions first synthesize a water-swellable urethane prepolymer,
Next, a complicated process is required in which the water-swellable urethane prepolymer is mixed with an elastomer, and then a curing agent is added and reacted to form a cross-linked water-swellable polyurethane.However, in the present invention, water-swellable urethane It is possible to form a water-swellable cross-linked polyurethane in a single reaction without using a curing agent, making it possible to industrially produce water-swellable water-stopping materials with great advantage. become capable.

The water-swellable water-stop material obtained as described above can be suitably used for segment sealing materials, Hume tube comb rings, hacking, separator water-stop plates, and the like.

Patent author: Denki Kagaku Kogyo Co., Ltd.

Claims (2)

[Claims] (1) A composition containing a sulfur-modified chloroprene rubber, a filler, and a reaction crosslinked product of a polyoxyalkylene glycol containing 50 to 90% by weight of oxyethylene units and an isocyanate consisting of a diisocyanate and a trifunctional or higher-functionality polyisocyanate. Water-swellable waterproof material made by vulcanizing. (2) After mixing sulfur-modified chloroprene rubber, filler, and polyoxyalkylene glycol containing 50 to 90% by weight of oxyethylene units, isocyanate consisting of diisocyanate and trifunctional or higher functional polyisocyanate is added to the hydroxyl groups of the polyalkylene glycol. N.C.O.
:OH is added in an amount in the range of 1.1:1 to 3.0:1 and reacted to produce a crosslinked product consisting of the polyoxyalkylene glycol and isocyanate, and then a vulcanizing agent is added, and then a vulcanizing agent is added. A method for producing a water-swellable water-stopping material, which comprises molding and then vulcanizing the obtained composition.