JP3360367B2 - Water stop composite - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates is related to water-absorbing rubber composition obtained by mixing a water-absorbent resin and rubber <br/> of fine, waterproof composite, for example, Ya water stopping material Used for caulking materials and the like.

[0002]

2. Description of the Related Art Heretofore, there have been known waterproof materials, packing, sanitary materials and the like using a water-absorbing resin.

For example, Japanese Patent Application Laid-Open No. 59-120653 discloses a water-absorbing material obtained by uniformly mixing a mechanically pulverized superabsorbent polymer in a rubber component.

Further, there is disclosed an invention in which an ion-sequestering agent is further added to the above-described water-absorbing material to prevent the swelling performance from being lowered or hardened (JP-A-60-92339).

However, the conventional water-absorbent resin is produced by suspension polymerization or gel polymerization, and the obtained polymer is finely divided into fine particles of 10 to 100 μm by mechanical pulverization.

[0006] By mechanical pulverization, angular particles are easily obtained, and the particle diameter is relatively large. Therefore, after kneading to make a product and then swelling with water, the smoothness of the surface is lost.

[0007] In addition, mechanical pulverization is disadvantageous in that a difference in physical properties between the inside and the outside of the gel mass is apt to occur, and that many of them are eluted when immersed in water after kneading the rubber.

[0008]

DISCLOSURE OF THE INVENTION The present invention relates to a water stopping water having a high swelling ratio and less elution due to water immersion by using fine particles having an average particle diameter of 5 μm or less produced by an emulsion polymerization method as a water-absorbing resin . A composite material is provided.

[0009]

The present invention is characterized in that (1) a water-in-oil type water-swellable polymer emulsion, which is a water-absorbent resin having an average particle diameter of 5 μm or less, and rubber are uniformly mixed. Composite for water stoppage ,

(2) An aqueous solution of a mixture of a water-soluble vinyl monomer and a crosslinking agent in a water-absorbent resin having an average particle size of 5 μm or less,
After emulsification in an organic dispersion medium in the presence of a hydrophobic surfactant,
The water- stop composite according to (1), which is a water-in-oil type water-swellable polymer emulsion obtained by polymerizing the same.

(3) The water- stop composite material according to (1), wherein the water-in-oil type water-swellable polymer emulsion is obtained by removing volatile substances such as water before, during or after polymerization. ,

(4) The composite material for waterproofing according to (1), wherein the rubber is natural rubber or synthetic rubber.

[0013]

The water-absorbent resin of the present invention having an average particle diameter of 5 μm or less is obtained by emulsifying an aqueous solution of a mixture of a water-soluble vinyl monomer and a crosslinking agent in an organic dispersion medium in the presence of a hydrophobic surfactant. A water-in-oil type water-swellable polymer emulsion obtained by polymerizing this is used.

The water-soluble vinyl monomer includes (1) a nonionic vinyl monomer, (2) an anionic vinyl monomer,
(3) It is selected from cationic vinyl monomers.

(1) As the nonionic vinyl monomer,
(Meth) acrylamide, vinyl methyl ether, vinyl ethyl ether, vinyl pyrrolidone, etc.
(2) Examples of the anionic vinyl monomer include (meth) acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, vinylsulfonic acid, styrenesulfonic acid, itaconic acid, maleic acid, fumaric acid, and arylsulfonic acid. And (3) the cationic vinyl monomer includes:
Neutralized salts or quaternized dialkylaminoalkyl (meth) acrylates such as dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, etc., dimethylaminomethyl (meth) acrylamide and dimethylaminopropyl (meth) acrylamide And dialkylaminoalkyl (meth) acrylamide.

The crosslinkable monomer is a copolymerizable with a water-soluble vinyl monomer and includes, for example, N, N'-methylenebis (meth) acrylamide, divinylbenzene, vinyl (meth) acrylate and the like. A divinyl compound,
Examples include vinyl-based methylol compounds such as methylol (meth) acrylamide, vinyl aldehyde compounds such as acrolein, and methyl acrylamide glycolate methyl ether.

The amount of the crosslinkable monomer used is 0.001 to 5% by weight, preferably 0.005 to 5% by weight, based on the total amount of the monomer.
It is compounded and polymerized at a ratio of 1% by weight.

If it is less than 0.001% by weight, it is partially solubilized and does not become water-swellable particles, and the effect is reduced. If it exceeds 5% by weight, the crosslink density is too large and the water swellability is deteriorated. It is not preferable because the interface area is reduced and the processing effect is reduced.

The water swellability in pure water is 20 to 1 in apparent volume.
000 times and the particle diameter is about 2.5 to 10 times.

The water-in-oil type water-swellable polymer emulsion comprises:
An emulsion obtained by emulsifying and dispersing an aqueous solution containing a water-soluble vinyl monomer and a crosslinkable monomer in an organic dispersion medium containing a hydrophobic surfactant and polymerizing using a radical polymerization initiator, or An emulsion obtained by removing volatile substances such as water to less than 25% by weight of the polymer before, during and / or after the polymerization.

If necessary, a hydrophilic surfactant can be added. The emulsion thus obtained is as follows.

Water-swellable polymer particles 25-75% by weight, organic dispersion medium 20-70% by weight, hydrophobic surfactant 0.5-75%
It comprises 5% by weight and 0 to 5% by weight of a hydrophilic surfactant, and the average particle diameter of the water-swellable polymer is 5 μm or less.

These polymerization methods can be carried out by a generally known method, for example, as described in JP-A-1-292070.
And Japanese Patent Application Laid-Open No. 2-296852.

Examples of the rubber include natural rubber and synthetic rubber.

The natural rubber or the synthetic rubber may be any of an uncrosslinked rubber, a partially crosslinked rubber and a crosslinked rubber. Examples of the uncrosslinked rubber include natural rubber, styrene-butadiene rubber, styrene-butadiene block copolymer and styrene- Isoprene block copolymer, butadiene rubber, isoprene rubber, acrylonitrile-butadiene rubber, acrylic rubber, ethylene-propylene-dienter-polymer rubber, ethylene-propylene rubber, chloroprene rubber,
Butyl rubber, halogenated butyl rubber, theocol, polyether rubber, ethylene-vinyl acetate rubber, hypalone, polyisobutylene, urethane rubber and the like are used.

As the partially crosslinked rubber, for example, a partially crosslinked butyl rubber or a reclaimed rubber is preferably used. As the crosslinked rubber, a crosslinking agent such as sulfur, magnesium oxide, zinc oxide, a lead compound, etc. A material obtained by adding a crosslinking accelerator and applying heat to perform so-called semi-vulcanization or vulcanization treatment is used.

These rubbers may be used alone or as a blend of two or more.

Also, various softeners, inorganic or organic reinforcing agents, fillers, anti-aging agents for preventing aging due to sunlight, heat, etc., to improve the hardness and hand of the rubber; Various oils, lubricants, coloring agents such as dyes and pigments, and the like can be added.

As the softener, for example, sub oil, mineral oil, vegetable oil, animal oil and the like are used. As the inorganic reinforcing agent and filler, for example, clay, magnesium carbonate, hydrated silica, calcium carbonate, carbon black and the like are used. As the reinforcing agent and the filler, for example, various fiber chips and plastic powders are used.

The mixing ratio of the water-absorbent resin and rubber, but may be determined by applications using the rubber 100 for normal use
1 to 300 parts by weight, preferably 50 to 20 parts by weight based on parts by weight
It is used in the range of 0 parts by weight.

The water-absorbent resin and the rubber can be mixed by a conventional method using a mixer such as a roll mixer, a Banbury mixer, an extruder or a coder.

The obtained composition has water- stopping property , water-holding property and water-absorbing property, and can be used, for example, for a water-stopping material, caulking, packing and the like.

In the present invention, if necessary, a filler, a coloring agent, a foaming agent, a crosslinking agent, an accelerator, a curing agent, a solvent,
Known substances such as a stabilizer, an antioxidant, and a fragrance may be mixed and used.

Hereinafter, the present invention will be described more specifically with reference to examples.

[0035]

EXAMPLES Production examples of the water-absorbing resin used in the examples will be described.

(1) 22.5 g of sorbitan monooleate is dissolved in 250 g of a hydrocarbon solvent having a boiling point of 158 to 177 ° C.

On the other hand, 315 g of sodium acrylate, N,
0.15 g of N 'methylenebisacrylamide and 0.03 g of ammonium persulfate are dissolved in 435 g of water, mixed with the previously dissolved hydrocarbon solution with stirring, and emulsified.

After the emulsion was deoxygenated by introducing nitrogen, an aqueous solution of sodium hydrogen sulfite was added dropwise and polymerized at 60 ° C.

After cooling to 40 ° C. after the polymerization, the boiling point was 400 ° C.
As described above, a hydrocarbon solvent 175 having a kinematic viscosity of 90 cSt / 40 ° C.
g, azeotropic distillation was performed under reduced pressure, and 420 g of water and 245 g of a hydrocarbon solvent having a boiling point of 158 to 177 ° C were distilled off.

The resulting emulsion was milky white, having a polymer concentration of 62%, a water content of 2.9%, an average particle diameter of 3.5 μm, and
It had a viscosity of 500 cps (B-type viscometer 30 rpm).

(2) The same procedure as in Example 1 was repeated except that 315 g of sodium acrylate was changed to 100 g of acrylamide and 215 g of sodium acrylate.

The obtained emulsion had a polymer concentration of 61.
%, Water content 3.0%, and viscosity of 1500 cps.

(3) The same procedure as in Example 1 was repeated except that 315 g of sodium acrylate was replaced with 300 g of quaternary methyl chloride of dimethylaminoethyl methacrylate.

The emulsion obtained had a polymer concentration of 58.
%, Water content 3.5%, and viscosity of 1300 cps.

(4) (Comparative Example 1) A commercially available powdery water-absorbing resin (Sumikagel SP-510 acrylic acid / vinyl alcohol copolymer, average particle size 10 μm, manufactured by Sumitomo Chemical Co., Ltd.) was used as it was.

(5) (Comparative Example 2) A commercially available powdery water-absorbing resin (Sumikagel NP-1020, manufactured by Sumitomo Chemical Co., Ltd., sodium acrylate polymer average particle diameter: 10 µm) was used as it was.

Next, examples of mixing with various materials will be described. (1) After kneading the compound of the following compounding ratio with a Banbury mixer, molding with an extruder,
A test piece was prepared by vulcanization at 60 ° C. for 30 minutes.

EPDM 100 parts by weight Zinc oxide 5 parts by weight Stearic acid 1 part by weight MBT 0.5 parts by weight TMTM 1.5 parts by weight Sulfur 1.5 parts by weight HAF black 50 parts by weight Hydrocarbon solvent 15 parts by weight + Production Example 1 2, 3 Comparative Examples 1, 2 5 parts by weight each

EPDM: ethylene propylene rubber, third
Ingredient, dicyclopentadiene MBT: 2-mercaptobenzothiazole TMTM: tetramethylthiuram monosulfide

(2) Kneading and molding in the same manner as in 1
A test piece was prepared by vulcanizing for 30 minutes.

CR 100 parts by weight Magnesium oxide 4 parts by weight Stearic acid 1 part by weight SRF black 29 parts by weight Zinc oxide 5 parts by weight EU 0.5 parts by weight + Production Examples 1, 2, 3 Comparative Examples 1, 2 5 parts by weight each

CR: chloroprene rubber EU: 2-mercaptoimidazoline

(3) The following proportions of the components were kneaded, and then poured into a mold to prepare a test piece.

Agent A (prepolymer) average molecular weight of about 2,0
By reacting the polyoxypropylene glycol of Example No. 00 with an excess of toluene diisocyanate, a prepolymer having a terminal isocyanate group content of 5% was prepared.

Agent B (curing agent) Liquid polyamine containing methylene bis (o-chloroaniline) 32 parts HAF black 30 parts Lead catalyst 4 parts 4,4'-thiobis (6-t-butyl-3-methylphenol) 1 part Hydrocarbon Solvent 33 parts

Agent A 50 parts by weight Agent B 50 parts by weight + Production Examples 1, 2, 3 Comparative Examples 1, 2 5 parts by weight each

Each test piece was evaluated by the following method. (1) Dissolution test based on JIS K 6353-Potassium permanganate consumption (COD value)

A test water containing 2 ppm of residual chlorine is prepared. Take 1 liter of this water, thoroughly wash the test piece having a surface area of 20 cm ² , remove water droplets, soak it, and leave it in a dark place at 20 ° C. ± 2 ° C. for 24 hours while avoiding ventilation with the outside. Collect water and use it as sample water.

Reagents and instruments are prepared in advance based on JIS K6353.

Transfer 100 ml of sample water into an Erlenmeyer flask,
Add 5 ml of dilute sulfuric acid, then add 10 ml of N / 100 potassium permanganate solution and boil for 5 minutes.

Next, 10 ml of an N / 100 sodium oxalate solution are immediately added, and an N / 100 potassium permanganate solution is further added dropwise until a faint red color remains without disappearing (a).
ml).

A blank is similarly processed (bml).

The potassium permanganate consumption is determined by the following equation.

[0064]

(Equation 1)

A: Potassium permanganate consumption (mg /
l) f: Factor of N / 100 potassium permanganate solution I: sample water (ml) B: 0.316 (mg / l)

(2) Water Absorption Swelling Ratio A test piece of ² cm × 3 cm × 0.8 cm (surface area: 20 cm ² ) is thoroughly washed with water, dried at 60 ° C. for 24 hours, and weighed (ag).

This is immersed in 1 liter of distilled water, and
After standing for 24 hours at, the test piece is taken out, the water content is sufficiently removed, and the weight is measured (bg).

The water absorption swelling ratio is determined by the following equation.

[0069]

(Equation 2)

(3) Change in water absorption swelling rate due to repeated water absorption swelling and drying shrinkage The water absorption swelling rate test piece used in (2) is used as it is.

The test specimen whose weight was measured after immersion in distilled water was dried at 60 ° C. for 24 hours.

This test piece was again subjected to distilled water 1 in the same manner as in (2).
and left at 20 ± 2 ° C. for 24 hours.

After immersion in distilled water and drying as described above 100 times, the water absorption swelling ratio is measured in the same manner as in (2).

The evaluation results are shown in Tables 1 to 3.

[0075]

[Table 1]

[0076]

[Table 2]

[0077]

[Table 3]

[0078]

The present invention has a COD value of 5 ppm or less, which is the COD standard value for waterworks, and is extremely low as compared with a commercially available powdery water-absorbent resin.

Further, the water absorption swelling ratio is sufficiently large, and is sufficiently useful as a waterproof packing.

Further, even when water absorption swelling and drying shrinkage are repeated, the decrease in the water absorption swelling ratio is extremely small as compared with a commercially available powdery water absorbent resin.

Continuation of the front page (56) References JP-A-1-252669 (JP, A) JP-A-62-285933 (JP, A) JP-A-1-292070 (JP, A) JP-A-1-2922071 (JP) , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 33/02 C08L 9/00-21/02

Claims (4)

(57) [Claims] 1. A composite material for waterproofing, wherein a water-absorbent resin having an average particle size of 5 μm or less, which is a water-in-oil type water-swellable polymer emulsion, and rubber are uniformly mixed. 2. A water-absorbent resin having an average particle size of 5 μm or less emulsifies an aqueous solution of a mixture of a water-soluble vinyl monomer and a crosslinking agent in an organic dispersion medium in the presence of a hydrophobic surfactant. The water- stop composite according to claim 1, which is a water-in-oil type water-swellable polymer emulsion obtained by polymerization. 3. The water- stop composite according to claim 1, wherein the water-in-oil type water-swellable polymer emulsion is obtained by removing volatile substances such as water before, during, or after polymerization. 4. A rubber natural rubber, or waterproof composite of claim 1 wherein the synthetic rubber.