JP2883156B2 - Water swellable resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention comprises uniformly kneading and dispersing a chlorinated linear ethylene / α-olefin copolymer having a specific crystallinity and a water-swellable resin. The present invention relates to a water-swellable resin composition useful as a water-stopping material.

(Conventional technology) Conventionally, a water-swellable resin composition comprising a synthetic rubber such as natural rubber or chloroprene rubber or a thermoplastic elastomer as a base material and a water-swellable resin blended therein is used to construct an underground buried pipe. It has been used to prevent water leakage from gaps due to later subsidence and as a segment waterproof material in shield construction methods.

However, water-stop materials based on natural rubber or synthetic rubber generally require a vulcanization step, and therefore have the disadvantage that the water-swelling material has a small degree of water swelling. Was not satisfactory.

When the latter is used as a base material, the water-stopping material can be streamlined without the need for a vulcanizing step, but if a large degree of water swelling is required, the physical strength of the water-stopping material after swelling is reduced. On the other hand, a water-stopping material satisfying both the water swelling degree and the physical strength was difficult to obtain, for example, when the physical strength was increased, the water swelling degree was reduced.

Among them, a large number of water-swellable water-stopping materials have been proposed in which a superabsorbent resin is blended with an ethylene / α-olefin copolymer or chlorinated polyethylene which is a chlorinated product thereof.

For example, in order to simultaneously achieve both properties of high water swelling and shape retention in the water-stopping material, it has been proposed to use EPR having a specific breaking strength, but a large amount of paraffin oil is added, Since water is absorbed and swelled in a non-crosslinked state, it has a certain physical strength before water swelling, but has a drawback that the strength is greatly reduced in a high water swelling state.

It has also been proposed that the same EPR be used to further increase the physical strength after water swelling, and that the clay be highly filled and vulcanized, but it was difficult to obtain a sufficient degree of water swelling. Further, in order to obtain a water-swellable water-stopping material having excellent weather resistance and heat resistance, it has been proposed to cross-link non-crystalline chlorinated polyethylene with a peroxide. It showed only the degree of water swelling and was not satisfactory.

(Problems to be Solved by the Invention) When a water-blocking material formed by blending chlorinated polyethylene and a water-swellable resin and swelling with water in an uncrosslinked state, chlorination with a low degree of chlorination and high crystallinity is achieved. Polyethylene has excellent physical strength, but the internal stress is larger than the water absorption swelling pressure of the water-swellable resin, so the water swelling degree of the water-stopping material is small and the effect as a water-swellable water-stopping material cannot be expected .

On the other hand, when a non-crystalline chlorinated polyethylene having a high degree of chlorination is used, not only the physical strength of the water-stopping material is small, but also when immersed in water, the swelling pressure of the water-swellable resin is reduced. May be larger than the cohesive force of the resin, and the shape may be lost.

Further, when such non-crystalline chlorinated polyethylene is used in a vulcanization system, the same drawbacks as in the case of vulcanized rubber occur, and there is a problem that the water swelling degree of the water-blocking material becomes extremely small.

The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, a specific chlorinated linear ethylene / α-olefin copolymer and a water-swellable resin are uniformly kneaded and dispersed to be molded. Excellent physical strength even when the water-stopping material is in a non-crosslinked state,
The present invention has been completed by finding that a high water swelling degree is exhibited.

(Means for Solving the Problems) That is, the present invention provides a method for converting an α-olefin having 3 to 12 carbon atoms into 2
Chlorinated linear ethylene / α-olefin having a chlorine content of 5 to 40% by weight and a crystallinity of 0.1 to 3.0 Cal / g, obtained by chlorinating a linear ethylene / α-olefin copolymer containing 40 mol% A water characterized by uniformly kneading and dispersing a copolymer and a water-swellable resin to give a molded article having excellent physical strength and a high degree of water swelling by molding without vulcanization or non-crosslinking. A swellable resin composition and a water-swellable resin molded article formed from the composition.

Preferred Embodiment Next, the present invention will be described in more detail with reference to preferred embodiments.

Chlorinated linear ethylene / α which characterizes the present invention first
The olefin copolymer is produced by suspending a specific ethylene / α-olefin copolymer in water and blowing chlorine as described below.

Production of ethylene / α-olefin copolymer Ethylene / α used as a raw material of the composition of the present invention
The α-olefin copolymerized with ethylene in the olefin copolymer has 3 to 12 carbon atoms. Specific examples include propylene, butene-1, 4-methylpentene-1, hexene-1, octene-1, decene-1, and dodecene-1.

Of these, propylene, butene-1, 4-methylpentene-1, and hexene-1 are particularly preferred. Further, as a comonomer, dienes such as butadiene, 1,4-hexadiene, vinylnorbornene, and ethylidene norbornene may be used in combination. Ethylene / α
-Α-olefin content in the olefin copolymer is 5 to 40
Preferably it is mol%.

First, the catalyst system to be used is a combination of a solid catalyst component containing at least magnesium and titanium and an organoaluminum compound. Examples of the solid catalyst component include metal magnesium, magnesium hydroxide, magnesium carbonate, magnesium oxide, and chloride. Magnesium, etc.
Also, double salts, double oxides, carbonates, chlorides or hydroxides containing a metal selected from silicon, aluminum and calcium and a magnesium atom, and furthermore, these inorganic solid compounds are oxygen-containing compounds, sulfur-containing compounds. Examples thereof include those in which a titanium compound is supported by a known method on an inorganic solid compound containing magnesium such as a compound treated or reacted with a compound, an aromatic hydrocarbon, or a halogen-containing substance.

Specific examples of these catalysts include, for example, MgO
-RX-TiCl ₄ system (JP-B-51-3514), Mg-SiCl ₄ −
ROH-TiCl ₄ system (Japanese Patent Publication No. 50-23864), MgCl ₂ -Al (O
R) ₃ -TiCl ₄ system (JP-B-51-152, JP-B-52-15111)
Publication), MgCl ₂ —SiCl ₄ —ROH—TiCl ₄ system (JP-A-49-10)
No. 6581), Mg (OOCR) ₂ -Al (OR) ₃ -TiCl ₄ system (Japanese Patent Publication No. Sho 5
2-171010), Mg-POCl ₃ -TiCl ₄ system (JP-B-51-15)
No. 3), MgCl ₂ —AlOCl—TiCl ₄ system (Japanese Patent Publication No. 54-15316)
_{JP), MgCl 2 -Al (OR)} n X 3 - n -Si (OR ') m X 4 - m -TiC
l ₄ system (during the above formula, R, R 'is an organic residue, X is a halogen atom) solid catalyst component (JP-56-95909 JP), etc. a combination of an organoaluminum compound in preferred Examples include catalyst systems.

As an example of another catalyst system, a catalyst product in which a reaction product of an organic magnesium compound such as a so-called Grignard compound and a titanium compound is used as a solid catalyst component, and an organic aluminum compound is combined with the reaction product can be exemplified.

As the organomagnesium compound, for example, the general formula RM
gX, R ₂ Mg, an organic magnesium compound such as RMg (OR) (where, R represents an organic residue having 1 to 20 carbon atoms, X is a halogen) and their ethers錯合body, also, these organomagnesium The compound is further converted to another organometallic compound, for example,
Those modified by adding various compounds such as organic sodium, organic lithium, organic potassium, organic boron, organic calcium, and organic zinc can be used.

Specific examples of these catalyst systems include, for example, RMgX-Ti
Cl ₄ system (Japanese Patent Publication No. 50-39470), RMgX-phenol-
TiCl ₄ system (Japanese Patent Publication No. 54-12953), RMgX-halogenated phenol-TiCl ₄ system (Japanese Patent Publication No. 54-12954), RMgX
Examples thereof include those in which an organic aluminum compound is combined with a solid catalyst component such as a —CO ₂ —TiCl ₄ system (JP-A-57-73009).

Further, examples of other catalyst systems include, as a solid catalyst component,
SiO ₂ , using a solid material obtained by catalyzing an inorganic oxide such as Al ₂ O ₃ and a solid catalyst component containing at least magnesium and titanium, and exemplifying a combination of an organic aluminum compound with the solid material. I can do it.

Specific examples of these catalyst systems include, for example, SiO ₂ -RO
H-MgCl ₂ -TiCl ₄ system (JP-A-56-47407), SiO _2-
R-O-R'-MgO- AlCl 3 -TiCl 4 system (JP 57-18730
5 _{JP), SiO 2 -MgCl 2 -Al (} OR) 3 -TiCl 4 -Si (OR ')
Series ₄ (JP-A-58-21405) (in the above formula, R,
R 'represents a hydrocarbon residue. ) And the like in combination with an organoaluminum compound.

Specific examples of the organoaluminum compound to be combined with the solid catalyst component described above include the general formulas R ₃ Al and R ₂ Al
X, RAlX ₂ , R ₂ AlOR, RAl (OR) X and an organic aluminum compound of R ₃ Al ₂ X ₃ (where R is an alkyl group having 1 to 20 carbon atoms, an aryl group or an aralkyl group, and X is a halogen atom) And R may be the same or different), and preferred are triethylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum, diethylaluminum chloride, diethylaluminum ethoxide, ethylaluminum sesquichloride and the like. Mixtures and the like can be mentioned.

Although the amount of the organoaluminum compound is not particularly limited, it can be usually used in an amount of 0.1 to 1,000 moles per mole of the titanium compound.

Further, by using the above-mentioned catalyst system in a polymerization reaction after being brought into contact with an α-olefin, the polymerization activity can be greatly improved and the operation can be performed more stably than an untreated one. As the α-olefin used at this time, various ones can be used, preferably an α-olefin having 3 to 12 carbon atoms, and more preferably an α-olefin having 3 to 8 carbon atoms. Examples of these α-olefins include, for example, propylene, butene-1, pentene-1, 4-methylpentene-1, hexene-1, octene-1, decene-1, dodecene-1, and the like, and mixtures thereof. Can be mentioned.

The temperature and time for the catalyst between the catalyst system and the α-olefin can be selected in a wide range, and for example, the contact treatment can be performed at 0 to 200 ° C, preferably 0 to 110 ° C for 1 minute to 24 hours. The amount of the α-olefin to be contacted can also be selected in a wide range, but usually 1 g to 50,000 per 1 g of the solid catalyst component.
g, preferably about 5 g to 30,000 α-olefin, and 1 g to 500 g of α-olefin per 1 g of the solid catalyst component. At this time, the pressure at the time of contact can be arbitrarily selected, but usually −1 to 100 kg / cm ² · G
It is desirable to make contact under a pressure of

During the α-olefin treatment, the total amount of the organoaluminum compound used is combined with the solid catalyst component, and
It may be brought into contact with an olefin, or a part of the organoaluminum compound to be used is combined with the solid catalyst component and then brought into contact with an α-olefin, and the remaining organoaluminum compound is added separately during polymerization. A polymerization reaction may be performed.

In addition, there is no problem if hydrogen gas coexists at the time of contact between the catalyst system and the α-olefin, and there is no problem even if other inert gases such as nitrogen, argon and helium coexist. The polymerization reaction is carried out in the same manner as the polymerization reaction of an olefin using a usual Ziegler-type catalyst. That is, all the reactions are carried out in a state in which oxygen, water and the like are substantially removed, in the presence of a gas phase or an inert solvent, or using the monomer itself as a solvent. Polymerization conditions olefin temperature 20 to 300 ° C., preferably from 40 to 200 ° C., the pressure is normal pressure ~70Kg / cm ² · G, preferably 2Kg / cm ² ·
G to 60 kg / cm ² · G. Although the molecular weight can be adjusted to some extent by changing the polymerization conditions such as the polymerization temperature and the molar ratio of the catalyst, it can be effectively adjusted by adding hydrogen to the polymerization system.

Of course, different polymerization conditions such as hydrogen concentration and polymerization temperature
Multi-stage polymerization reactions of stages or more can be carried out without any problem. Of these, the gas phase polymerization method is preferred.

The linear ethylene / α-olefin copolymer, which is a preferred raw material of the present invention, is a copolymer of ethylene and α-olefin in the presence of a catalyst comprising at least a solid catalyst component containing magnesium and titanium and an organoaluminum compound. The preferred physical properties are as follows.

That is, the melt index (190 according to JIS K6760)
° C and 2.16 kg, hereinafter referred to as “MI”) is 0.01
100 g / 10 min., Preferably 0.1 to 50 g / min. Density (by JIS K6760) is 0.860~0.910g / cm ^3, preferably
0.870-0.905 g / cm ³ , more preferably 0.880-0.900 g / cm ³
It is. The maximum peak temperature (Tm) by differential scanning calorimetry (DSC) is 100 ° C. or more, preferably 110 ° C., and the boiling n-hexane insoluble content is 10% by weight or more, preferably 20 to
It is 95% by weight, more preferably 30 to 90% by weight.

MI of ethylene / α-olefin copolymer is 0.01g / 10mi
If it is less than n., the fluidity will decrease, and if MI exceeds 100 g / 10 min., the tensile strength of the chlorinated product will decrease, which is not desirable.

Chlorination of linear ethylene / α-olefin copolymer As the chlorination method of the linear ethylene / α-olefin copolymer used in the present invention, a known method can be used. For example, a powdery polymer is suspended in water, and the temperature is adjusted to about 70 to 80 ° C, preferably 90 ° C under appropriate pressure.
An aqueous suspension method of reacting the polymer with chlorine while keeping the above, a method of reacting the polymer with chlorine by dissolving the polymer in an organic solvent such as tetrachloroethylene, or N-
There is a method in which a chlorine compound such as chloracetamide is previously blended with a polymer, heated to a temperature at which the chlorine compound is decomposed and chlorine is liberated, and the liberated chlorine reacts with the polymer. Particularly, a chlorination method using an aqueous suspension method is preferred.

It is important that the chlorinated linear ethylene / α-olefin copolymer used in the present invention has a crystallinity of 0.1 to 3.0 Cal / g. A water-stopping material comprising an amorphous chlorinated linear ethylene / α-olefin copolymer having substantially no crystallinity is not preferred because it exhibits cold flow properties.

Since the water-stopping material comprising the water-swellable resin composition of the present invention is used without being particularly crosslinked or vulcanized, it is an important characteristic that it has no cold flow property. The crystallinity is 3.0C
If it is more than al / g, the elongation of the water-stopping material is inferior, and the degree of water swelling as the water-stopping material decreases, which is similarly unfavorable.

The chlorine content of the chlorinated linear ethylene / α-olefin copolymer of the present invention is 3 to 50% by weight, preferably 5 to 50% by weight.
If it is less than 5% by weight, it is difficult to uniformly knead it with the water-swellable resin, while if it exceeds 40% by weight, heat resistance and low-temperature properties as a water-stopping material are reduced. Neither is preferred.

It is considered that the reason why the chlorinated linear ethylene / α-olefin copolymer used in the present invention is preferable is as follows.

That is, since the low-density ethylene / α-olefin copolymer before chlorination has a high degree of branching, it has many amorphous portions and exhibits a soft state and has microcrystalline portions. Absent. The adjustment of the amount of microcrystals can be arbitrarily changed by controlling the amount of the comonomer α-olefin or the like. The chlorination by the aqueous suspension method is preferred in order to maintain this characteristic without disappearing during chlorination.

That is, the fine particles dispersed in water below the melting point of the low-density ethylene / α-olefin copolymer are chlorinated only on the surface,
It is considered that the crystal in that portion almost disappears, but chlorination does not proceed to the inside, and the state of fine crystals remains.

For these reasons, it is believed that chlorinated low density ethylene / α-olefin copolymers are suitable for the purpose of the present invention. Although it is possible to leave some amount of crystals when chlorinating other high-density and low-density polyethylene,
When the composition of the present invention is used as a substrate, satisfactory results cannot be obtained, and it is considered that there is a difference in crystal state.

The preferred ethylene / α-olefin copolymer of the present invention described above is suitable for the amount of the microcrystalline portion and the like.
If the chlorinated product is blended with a water-swellable resin, a water-stopping material made of the obtained composition is preferable because it has an appropriate shape-retaining property.

The water-swellable resin used in the present invention and the second feature of the present invention may be any of conventionally known resins, for example, a saponified starch / acrylonitrile graft copolymer, a starch / acrylic acid graft polymer. A crosslinked product of an alkali metal salt, a crosslinked product of an acrylic acid-alkali metal acrylate copolymer, a saponified product of an ethylene-vinyl ester-acrylate copolymer, and an alkali metal salt of an isobutylene-maleic anhydride copolymer Any of conventionally known products such as a crosslinked product, a crosslinked product of an alkali metal salt of carboxymethyl cellulose, a crosslinked polyethylene oxide, and a water-swellable polyurethane resin can be used.

Particularly preferred water swellable resin in the present invention,
It is a block copolymer or a graft copolymer of a hydrophobic polymer segment and a hydrophilic polymer segment.
For example, it is described in JP-B-56-50886, JP-B-56-54002, JP-B-57-48001, and JP-B-57-48008. Most preferred among such block or graft copolymers are those in which the hydrophilic group of the hydrophilic polymer segment is an alkali metal salt of a carboxylic or sulfonic acid.

The above water swellable resin has characteristics in water swelling degree, water absorption rate, gel strength and water swelling degree with respect to water containing salt such as seawater or groundwater, and one or more kinds thereof are used. They may be used in combination. The use ratio is selected at an arbitrary ratio depending on the required degree of water swelling and the use environment.

The chlorinated linear ethylene / α-olefin copolymer and the water-swellable resin used in the present invention can be blended in an arbitrary ratio. The water-swellable resin is preferably blended in an amount of 10 to 400 parts by weight per 100 parts by weight of the chlorinated linear ethylene / α-olefin copolymer, depending on the balance of the strength or the use.
When the amount of the water-swellable resin is less than 10 parts by weight, the obtained water-stopping material has a low water-swelling degree and is not practical. On the other hand, if the amount exceeds 400 parts by weight, the physical strength of the water-stopping material is insufficient and the water-swellable resin powder is excessively present, so that the processability and the moldability are impaired.

The essential components of the water-swellable resin composition of the present invention are as described above, but conventionally known high-density polyethylene, linear low-density polyethylene, high-pressure polyethylene, as long as the performance as a water-stopping material is not changed. Crystalline polyolefins such as polypropylene or their chlorinated products, natural rubber, various synthetic rubbers, thermoplastic elastomers and conventionally known crosslinking agents for chlorinated polyethylene, plasticizers, process oils, polybutenes, carbon black, various dyes and pigments, calcium carbonate Various fillers such as clay and clay, reinforcing agents, stabilizers, antioxidants, antiozonants, flame retardants, foaming agents and the like can be optionally added as required.

The above components can be easily and uniformly dispersed by using a conventionally known kneader such as a two-roll mill, a Banbury mixer, a kneader, or an extruder. These kneaded materials are molded by any known molding machine. For example, a string-shaped or sheet-shaped water-stopping material can be obtained by using a normal extruder. In addition, water swelling of an arbitrary shape is performed by forming a wide sheet by using a calender roll, forming an O-ring or the like by injection molding, or obtaining a molded product having various complicated shapes by press molding. A molded article of the conductive resin composition can be obtained.

(Function / Effect) The water-swellable resin composition obtained in the present invention is based on a chlorinated linear ethylene / α-olefin copolymer obtained by chlorinating a specific ethylene / α-olefin copolymer. It has excellent physical strength and fast water swelling speed, and shows high degree of water swelling even though vulcanization step and crosslinking by peroxide are unnecessary. .

In particular, when used as a waterproof material for joints such as fume pipes and PVC pipes buried underground, they have large volume swelling even if large gaps are created due to uneven settlement, etc. Is blocked and water leakage is prevented.

Also, when used as a segment waterproofing material for a shield at a large depth, it has a swelling pressure that can withstand a large underground water pressure, so that infiltration of groundwater into the shield can be prevented.

The water-swellable resin composition of the present invention preferably has excellent properties because it is related to a combination of a specific chlorinated product of a linear ethylene / α-olefin copolymer and a specific water-swellable resin composition. . In particular, since the water-swellable resin composition of the preferred combination of the present invention is used without crosslinking or vulcanization, it has excellent affinity between the chlorinated product and the water-swellable resin, particularly when dipped in water. For example, the water-swellable resin does not detach when immersed in water.

In addition, the water-swellable resin composition of the present invention can be advantageously used for other applications, such as a water-cooling material, a soil water-retaining material, a dew condensation preventing material, a water-absorbing mat, etc., in addition to being used as a water-stopping material. .

(Examples) Next, the present invention will be described more specifically with reference to examples and comparative examples. In the following, "parts" and "%" are based on weight unless otherwise specified. The water swelling is a value calculated as follows.

Degree of water swelling = weight of sample after water absorption / dry weight of sample Further, chlorinated linear ethylene / α-olefin copolymer and water swellable resin used in Examples and Comparative Examples are produced by the following production method. It was done.

Chlorinated linear ethylene / α-olefin copolymer Ethylene and butene using a catalyst consisting of triethylaluminum and a solid catalyst component obtained from substantially anhydrous magnesium chloride, 1,2-dichloroethane and titanium tetrachloride. / Butene obtained by copolymerizing -1 with
1 Copolymer resin was mechanically pulverized at room temperature to a particle size passing through a 32 mesh wire mesh.

5 kg of this ethylene / butene-1 copolymer resin powder was charged into a 100-liter glass-lined autoclave together with 70 l of ion-exchanged water, 2 g of a wetting agent, and 200 ml of a dispersing agent.
After initiating the reaction at 100 ° C. while blowing chlorine gas under stirring and maintaining the same temperature, chlorination was performed until a predetermined chlorine content was reached, followed by washing and drying by a conventional method. 15% and 30% were prepared. Crystallinity is each
It was 2.2 and 1.8 Cal / g by DSC method.

The physical properties of the ethylene / butene-1 copolymer as the raw material before the chlorination are as follows.

Density: 0.905 g / cm ³ Butene-1 content: 7.7 mol% Melt index: 1.0 g / 10 min. Maximum peak temperature of DSC: 122 ° C. Boiling n-hexane insoluble matter: 94% by weight In the present invention, boiling n- Hexane insolubles and DSC
Is as follows.

(Measurement method of boiling n-hexane insoluble matter) A 200-μm-thick sheet is formed by using a hot press, and three 20 mm × 30 mm sheets are cut out from the sheet, and are cut out using a double tube Soxhlet extractor. And extract with boiling n-hexane for 5 hours. The n-hexane insolubles are taken out, dried in vacuum (7 hours, under vacuum, 50 ° C.), and the boiling n-hexane insolubles (X, wt%) is calculated by the following equation.

(Measurement method by DSC) Approximately 5mg from a 100μm thick film formed by hot press
After accurately weighing the sample, setting it in the DSC device, raising the temperature to 170 ° C. and maintaining it at that temperature for 15 minutes, the temperature was lowered at a rate of 25 ° C./mi
Cool to 0 ° C with n. Next, from this state, the heating rate is 10 ° C.
The temperature is raised to 170 ° C at / min. 0 ° C to 170 ° C
The temperature at the position of the peak of the maximum peak that appears during the temperature rise is defined as _Tm .

Water-swellable resin (polystyrene)-(polybutadiene)-(polystyrene) block copolymer (polystyrene content 30%)
Thioglycolic acid is added to almost all of the double bonds of
A water-swellable resin A (sodium absorption: 150 times) in the form of a sodium salt of carboxylic acid was obtained.

Acrylic acid-sodium acrylate (75% mol of carboxylic acid of acrylic acid neutralized with caustic soda) to which potassium persulfate and N, N'-methylenebisacrylamide were added was prepared, and cyclohexane-sorbitan monostearate was prepared. The mixture was added dropwise to the rate solution with stirring to prepare a suspension. Then, the mixture was reacted at 60 ° C. for 6 hours to distill cyclohexane, and dried under reduced pressure at 70 ° C. to obtain a water-swellable polymer B.
(400 times the water absorption).

Example 1 To 100 parts of a chlorinated linear ethylene / α-olefin copolymer having a chlorine content of 15%, 75 parts of a water-swellable resin A and 2 parts of a tin-based stabilizer were kneaded with two rolls. Next, the obtained kneaded material was subjected to press molding at 160 ° C. and 150 kg / cm ² for 3 minutes to obtain sheets having a thickness of 1 mm and 3 mm.

For a sheet having a thickness of 1 mm, the tensile strength and other physical properties were measured based on JIS K-6301. A sheet having a thickness of 3 mm was cut into a size of about 1 cm square, and the degree of water swelling in distilled water was measured. Table 1 shows the results.

Examples 2 to 8 As shown in Table 1, the same operation as in Example 1 was carried out except that the chlorination degree of the chlorinated linear ethylene / α-olefin copolymer, the water-swellable resin and the amount of addition thereof were changed. Was repeated to prepare a sheet, and its physical properties and water swelling were measured. Table 1 shows the results.

Comparative Examples 1-2 Using a chlorinated polyethylene having a chlorine content of 30% and a crystallinity of 3.4 Cal / g produced by chlorinating high-density polyethylene according to the aqueous suspension method described above, The same operation as in Example 1 was repeated with the composition shown in the table to prepare a sheet. Table 1 shows the results.

Example 9 In order to evaluate the performance of the water-swellable resin compositions obtained in Examples and Comparative Examples, a static pressure test device composed of two iron disks was prepared. The test apparatus mainly includes two circular flat plates made of steel and having a thickness of 20 mm and a water supply pressurizing pump, and a seal groove is provided in the circular flat plate on the lower surface.

Using a 60 mm extruder, the kneaded material obtained in Example 2 and Comparative Example 1 was used to obtain a string-shaped water-swellable waterproof material having a cross section of 20 mm in width and 3 mm in thickness.

The above water-swellable water-stopping material is attached to the lower seal groove of the test device with an epoxy-based adhesive, and a 2 mm spacer is placed on the opposite surface between the upper surface and the lower surface, so that 1 mm between the upper surface and the water-stopping material.
Clearance was provided.

The upper and lower parts of the test apparatus were tightened with dowel bolts, a water supply pressurizing pump was set, a predetermined pressure was applied, and the time-dependent change in the presence or absence of water leakage was observed. The result is shown in FIG. As is clear from the figure, even after 9 months, it was able to withstand the water pressure of 7 KG / cm ² .

The water-swellable water-stopping material obtained in the present invention swells with water despite having a clearance of 1 mm with respect to the thickness,
The space is closed by the increase in volume. Moreover, since the contained water-swellable resin swells with water, the water-swellable water-stopping material sandwiched between the upper and lower two disks exhibits a high swelling pressure on the disks. As a result, it can withstand high-pressure water and can be used for construction several tens of meters below ground.

[Brief description of the drawings]

FIG. 1 is a diagram showing the relationship between pressure and water leakage in the ninth embodiment.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hitoshi Takeuchi 261-25 Yonejima, Showa-cho, Kita-Katsushika-gun, Saitama Prefecture (72) Inventor Michie Nakamura 475-6, Kinmeicho, Soka-shi, Saitama -126448 (JP, A) JP-A-61-43641 (JP, A) JP-A-57-147570 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08L 23/00- 23/36

Claims (2)

(57) [Claims] 1. A chlorinated linear ethylene / α-olefin copolymer containing 2 to 40 mol% of an α-olefin having 3 to 12 carbon atoms, a chlorine content of 5 to 40% by weight and a crystallinity of 0.1.
~ 3.0 Cal / g chlorinated linear ethylene / α-olefin copolymer and water-swellable resin are uniformly kneaded and dispersed,
A water-swellable resin composition which is molded by non-vulcanization or non-crosslinking to give a molded article having excellent physical strength and high water swelling degree. 2. A chlorinated linear ethylene / α-olefin copolymer containing 2 to 40 mol% of an α-olefin having 3 to 12 carbon atoms, a chlorine content of 5 to 40% by weight and a crystallinity of 0.1.
A water-swellable resin composition obtained by uniformly kneading and dispersing a water-swellable resin with a chlorinated linear ethylene / α-olefin copolymer of up to 3.0 Cal / g in a non-vulcanized or non-crosslinked form. A water-swellable resin molded product characterized by comprising: