JP2986014B2 - Water-swellable resin composite and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a water-swellable resin composite. More specifically, the present invention relates to a water-swellable resin composite which is suitable for a water-blocking material in civil engineering, construction, and other various fields, and provides a long-term stable water-swelling performance and a confidential waterproofing effect, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, a water-swellable resin composition in which a water-swellable urethane is blended with a rubber is as follows: (1) A water-swellable urethane which has been preliminarily urethanized is blended with a rubber and then the rubber is crosslinked. (For example, Japanese Patent Application Laid-Open No. 57-23654), and (2) a method in which a rubber is kneaded with a hydrophilic polyol and a polyisocyanate, and a urethane-forming reaction is performed during kneading, followed by crosslinking of the rubber (for example, 3-938
No. 78) and (3) a compound containing a water-swellable urethane having a functional group capable of reacting at the time of rubber crosslinking (for example, JP-A-57-119972).

[0003]

However, the above-mentioned (1) dissolves urethane upon swelling in water; the (2) has high reactivity of polyisocyanate, and other than polyol during kneading (for example, water and rubber). And (3) require the use of a special hydrophilic polyol, the composition is limited, and the economical efficiency is inferior.

[0004]

Means for Solving the Problems The present inventors have made intensive studies on a water-swellable resin composition which has very little elution of water-swellable urethane and which can be easily and stably produced. .

That is, the present invention provides a kneaded product of a polyoxyethylene-based water-swellable polyurethane resin having a blocked isocyanate group and an active hydrogen-containing group, and an unvulcanized rubber.
A water-swellable resin composite cured and vulcanized; and a partial block of a terminal isocyanate group-containing prepolymer from a polyoxyalkylene polyol (a) having at least 30% by weight of oxyethylene units and an organic polyisocyanate (b) A kneaded product of a water-swellable polyurethane resin having a blocked isocyanate group and an active hydrogen group and an unvulcanized rubber obtained by reacting a compound (A) with an active hydrogen-containing compound (B) is vulcanized. The present invention relates to a method for producing a water-swellable resin composite, which comprises regenerating an isocyanate group at a temperature and curing the polyurethane resin together with vulcanization of rubber.

As the polyoxyalkylene polyol (a) constituting the partially blocked product (A), low molecular weight polyols (ethylene glycol, propylene glycol,
Bifunctional polyols such as 1,4-butanediol, cyclohexylene glycol, N-methyldiethanolamine; glycerin, trimethylolpropane, triethanolamine, pentaerythritol, sorbitol,
Trifunctional or more polyols such as shoe close),
Phenylene group-containing polyols (hydroquinone, resorcin, catechol, etc.), bisphenols (bisphenol A, bisphenol B, bisphenol F, bisphenol S, etc.), amines [amino alcohol (monoethanolamine, etc.), alkylene polyamines (ethylenediamine, diethylenetriamine, etc.) , Alicyclic diamines (such as isophorone diamine), heterocyclic polyamines (such as aminoethylpiperazine)] and the like, and ethylene oxide (hereinafter abbreviated as EO) adducts and / or EO and other alkylene oxide additions. (One or more of alkylene oxides having 2 to 4 carbon atoms, such as propylene oxide (hereinafter abbreviated as PO), butylene oxide, tetrahydrofuran, etc.) Nothing or block), and the like. Of these, preferred are co-adducts (random or block) of EO and PO of dihydric alcohols (especially ethylene glycol and propylene glycol), and co-addition of EO and PO of phenylene group-containing polyols (especially hydroquinone and bisphenol A). (Random or block), and combinations thereof.
It is preferable that the content of the oxyethylene unit (a) is usually at least 30% by weight. When the content of the oxyethylene unit is less than 30% by weight, the coefficient of water swelling is insufficient, and a sufficient function as a water-swellable rubber cannot be exhibited.

[0007] As the organic polyisocyanate (b),
Aromatic polyisocyanates (2,4- or 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, m- or p-phenylene diisocyanate, 1 , 5-naphthylene diisocyanate); aliphatic and / or alicyclic polyisocyanates [ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,
2,4-trimethylhexane diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethyl caproate, bis (2-isocyanatoethyl) fumarate, bis (2-isocyanatoethyl) carbonate, isophorone diisocyanate (IPDI), dicyclohexylmethane Diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI), bis (2-isocyanatoethyl) 4-cyclohexene-1,2-dicarboxylate, etc.]; and modified products of these diisocyanates ( A modified product containing a carbodiimide group, a uretdione group, a uretoimine group, a urea group, a buret group, an isocyanurate group, or the like. In consideration of chemical resistance, weather resistance and the like, preferred among these are aliphatic and / or alicyclic diisocyanates, and particularly preferred are HDI, IPDI and hydrogenated MDI.

The blocking agent (c) used in the present invention includes lactams (α-pyrrolidone, γ-butyrolactam, δ-valerolactam, ε-caprolactam, etc.),
Phenols (phenol, cresol, etc.), oximes (dimethyl ketoxime, methyl ethyl ketoxime, diethyl ketoxime, methyl isobutyl ketoxime, etc.), carboxylic esters (dimethyl malonate, diethyl malonate, etc.), alcohols (methanol, Ethanol, n-butanol, etc.), hydroxyl group-containing esters (ethyl lactate, amyl lactate, etc.), mercaptans (butyl mercaptan, hexyl mercaptan, etc.), acid amides (acetanilide, acrylamide,
Dimer acid amide, etc.), imidazole, 2-ethylimidazole), acid imides (succinimide, phthalimide) and the like.

The partially blocked product (A) is prepared by reacting a polyoxyalkylene polyol (a) with an excess equivalent of an organic polyisocyanate (b) by an ordinary method (70 to 130 ° C.) and containing a terminal isocyanate group (usually 2 to 2). 15% by weight,
(Preferably 4 to 10%) a urethane prepolymer, and usually 2 to 2 isocyanate groups of the urethane prepolymer.
It is obtained by reacting an amount of (c) in which 50 equivalent%, preferably 5 to 40 equivalent% is blocked in a usual manner (50 to 120 ° C.). If the blocking is less than 2 equivalent%, the effect of urethane formation during vulcanization (prevention of falling off of the water-swelling component) becomes insufficient, and if it exceeds 50 equivalent%, the Mooney viscosity of the water-swelling urethane becomes [20 ML (1 + 4) 125 ° C]. It becomes difficult to do above.

The active hydrogen-containing compound (B) includes, for example, low molecular weight polyols and low molecular weight polyamines (isophoronediaminedicyclohexylmethanediamine, tolylenediamine, diethyltolylenediamine, dimethylthioamine) exemplified as the starting material of the above (a). -Tolylenediamine, 4,4'-diamino-3,3'-dichlorodiphenylmethane, diphenylmethanediamine, etc.) and their alkylene oxide adducts. In order to increase the expansion ratio of the water-swellable resin composite, it is preferable to use a compound containing a (poly) oxyethylene group in (B).

The water-swellable polyurethane resin has an equivalent ratio of the active hydrogen group of (B) to the total of the isocyanate group and the blocked isocyanate group of (A) of 0.9 to 2.0.
(A) and (B) are mixed so as to be 0, and usually 70 to 1
It is obtained by reacting at 20C, preferably 90-120C for 0.5-5 hours. If the equivalent ratio between the isocyanate group and the active hydrogen group is less than 0.9, the urethane bond concentration will be insufficient, and the amount of eluate in water during water expansion will increase. If it exceeds 2.0, the isocyanate group reacts with an active hydrogen group other than the active hydrogen group in (B), causing foaming and curing failure.

In the production of the water-swellable polyurethane resin, a known urethanization catalyst may be used if necessary. Examples of the catalyst include organometallic catalysts (dibutyltin dilaurate, lead octylate, stannas octaate, etc.) and tertiary amine compounds (triethylamine,
Triethylenediamine).

The Mooney viscosity of the water-swellable polyurethane resin is usually preferably at least [20 ML (1 + 4) 125 ° C.]. More preferably, [30ML (1 + 4) 12
5 ° C.] or higher. Mooney viscosity is [20ML (1+
4) When the temperature is less than 125 ° C.], the viscosity of the compound of the water-swellable urethane resin and the unvulcanized rubber is too low, and it is difficult to maintain the shape after extrusion.

The unvulcanized rubber used in the water-swellable resin composite of the present invention includes natural rubber, synthetic rubber and reclaimed rubber, such as natural rubber, styrene butadiene rubber, butadiene rubber, isoprene rubber, chloroprene rubber, Examples thereof include acrylonitrile-butadiene rubber, ethylene-propylene-diene rubber, butyl rubber and their reclaimed rubbers, and are selected depending on the use and purpose.
Preferred among these are ethylene-propylene-
Diene rubber, chloroprene rubber and acrylonitrile-butadiene rubber.

Examples of the crosslinking agent for the unvulcanized rubber include sulfur, sulfur chloride, and organic peroxides (benzoyl peroxide, dicumyl peroxide, methyl ethyl ketone peroxide,
Lauryl peroxide, cyclohexanone peroxide, t-butyl perbenzoate, t-butyl hydroperoxide, t-butylbenzene peroxide, cumene hydroperoxide, t-butyl peroctoate, etc.), organic sulfur compounds (tetramethylthiuram disulfide) , N, N'-dithiobismorpholine, etc.) Metal oxides (zinc white, magnesia, litharge, etc.), alkylphenol resins, polythiol compounds [trimethylolpropanetrithioglycolate, trimethylolpropanetri (3-mercaptopropio) ), Glycol dimercaptopropionate, glycol dimercaptoacetate, pentaerythritol tetrathioglycolate, dipentaerythritol hexa (3-mercaptopropionate) ], Polyamine compounds (aldehyde-amine condensates, guanidines, etc.), azo compounds (azobisisobutyronitrile, 2-tert-butylazo-2-cyano-4-methylpentane, 4-tert-butylazo-4-cyano) -Valeric acid, etc.).

The above crosslinking agents can be used alone or in appropriate combination of two or more kinds. The compounding amount is suitably 0.5 to 10 parts by weight based on 100 parts by weight of the unvulcanized rubber. .

The water-swellable resin composite of the present invention may optionally contain a filler (eg, carbon black, anhydrous calcium silicate, calcium carbonate, zinc oxide, clay, etc.), a vulcanization accelerator (eg, guanidine, amine) Thiazole, thiuram, etc.), vulcanization accelerators, lubricants, foaming agents, stabilizers, softeners, antioxidants and other known additives. If necessary, a trifunctional or more functional blocked isocyanate compound (for example, a completely blocked product of polyphenylene polyphenyl isocyanate) may be blended with the crosslinking agent as a urethane crosslinking agent at the time of vulcanization.

In particular, when compounding with a nonpolar rubber (for example, ethylene-propylene-diene rubber), a dispersant having compatibility or reactivity with both the nonpolar component and the polar component can be compounded. As such a dispersant, a carboxylic acid group, a carboxylic acid group, a carboxylic acid anhydride group, an amide group,
Modified polyolefin-based dispersants containing at least one functional group selected from the group consisting of a hydroxyl group and an epoxy group are exemplified.

The water-swellable resin composite of the present invention is obtained by kneading a water-swellable urethane resin together with a filler and the like in an unvulcanized rubber using a Banbury mixer, kneading the vulcanizing agent on a roll,
It is obtained by vulcanization by extrusion molding, press molding or the like. The amount of the water-swellable urethane resin is 2 per 100 parts by weight of rubber.
0 to 300 parts by weight, preferably 30 to 200 parts by weight. If less than 20 parts by weight, sufficient water swelling ability does not appear,
If the amount is more than 300 parts by weight, good processability and moldability as rubber are lost. The vulcanization temperature is set according to the type of the blocking agent, and must be equal to or higher than the dissociation temperature of the blocking agent.

[0020]

The water-swellable resin composite of the present invention is stable and has no reactivity during compounding and kneading because the isocyanate group of the water-swellable urethane resin is blocked. Processing on rolls is easy. It can be molded by the usual molding method (extrusion molding, press molding, etc.) with rubber, and the urethane-forming reaction is performed in the rubber at the vulcanization temperature. The elution of the water-absorbing component is remarkably reduced, and stable expansion performance is exhibited over a long period of time. By adjusting the oxyethylene content of the water-swellable urethane resin and the compounding amount of the rubber with the rubber, the crosslinking density of the rubber, etc., the weight of the resin is 10 to 30
It becomes a water-swellable material that expands by absorbing 0% by weight of water.

The water-swellable resin composite of the present invention is (1) extruded or co-extruded with a non-expandable rubber to form a sealing material for segments of various cross-sectional shapes;
For building gaskets, etc. by forming into a hollow or plate shape using weather-resistant rubber; (3) For water-swelling packing such as grout holes by forming into a ring shape with a circular cross section by press forming It can be suitably used.

[0022]

EXAMPLES The present invention will be further described with reference to examples below, but the present invention is not limited to these examples. In the following,% means% by weight, and parts means parts by weight.

[Production of Water-Swellable Polyurethane Containing Blocked Isocyanate Group] Production Example 1 A mixture of bisphenol A and EO and PO (weight ratio 80 /
The prepolymer having an isocyanate group content of 5.5% was obtained by reacting 1000 g of polyether glycol having a number average molecular weight of 4000 obtained by adding the above 20) with 170 g of dicyclohexylmethane diisocyanate. Next, 65 g of ε-caprolactam (2 g per isocyanate group)
(5% equivalent), 415 g of an EO adduct of bisphenol A (number average molecular weight 670) in an amount such that the equivalent ratio of hydroxyl groups to isocyanate groups of the prepolymer before blocking is 1.3 and lead octylate 1. Add 65g and add 1
After reacting at 10 ° C. for 4 hours, Mooney viscosity [37 ML
(1 + 4) 125 ° C.] water-swellable polyurethane resin, A
B-1 was obtained.

Production Example 2 A mixture of EO and PO in propylene glycol (weight ratio 5
0/50), 350 g of a polyether glycol having a number average molecular weight of 4000 and bisphenol A
A mixture of 650 g of an EO adduct (number-average molecular weight: 670) and 236 g of isophorone diisocyanate was reacted to obtain a prepolymer having an isocyanate group content of 7.2%. Next, after reacting 103 g of α-pyrrolidone (40% equivalent to isocyanate group), the equivalent ratio of the prepolymer before blocking to the isocyanate group is 1.6.
80.9 g of hexamethylenediamine was added to the mixture, and reacted at 70 ° C. for 2 hours to obtain a Mooney viscosity [49M
L (1 + 4) 125 ° C.], a water-swellable polyurethane resin,
AB-2 was obtained.

Production Example 3 A mixture of bisphenol A and EO and PO (weight ratio 80 /
20), and 1000 g of a polyether glycol having a number average molecular weight of 4000, and duranate D-10.
760 g of 1 (a modified product of hexamethylene diisocyanate manufactured by Asahi Kasei Corporation) was reacted to obtain a prepolymer having an isocyanate group content of 8.5%. Next, 177 g of thiophenol (40% equivalent to isocyanate group)
After the reaction, an amount of EO and PO adducts of propylene glycol (weight ratio: 50) in which the equivalent ratio of hydroxyl groups to isocyanate groups of the prepolymer before blocking is 1.8.
/ 50, number average molecular weight 2000) 2160 g and lead octylate 20.5 g were added and reacted at 100 ° C. for 4 hours,
AB-3, a water-swellable polyurethane resin having a Mooney viscosity of [55 ML (1 + 4) 125 ° C], was obtained.

[Production of Comparative Water-Swellable Urethane] Comparative Production Example 1 A mixture of bisphenol A and EO and PO (weight ratio 80 /
The prepolymer having an isocyanate group content of 4.0% was obtained by reacting 1000 g of polyether glycol having a number average molecular weight of 4000 obtained by adding the compound (20) with 159 g of dicyclohexylmethane diisocyanate. The equivalent ratio of hydroxyl groups to isocyanate groups of the prepolymer is 1.
336 g of an EO adduct of bisphenol A (number-average molecular weight 670) and 7.5 g of lead octylate were added thereto, and reacted at 110 ° C. for 2 hours to obtain a Mooney viscosity [50].
ML (1 + 4) 125 ° C.] to give a water-swellable polyurethane resin C-1.

Examples 1-3, Comparative Example 1 Production Example 1 with 100 parts of ethylene-propylene-diene rubber
AB-1 to AB-3 and C obtained in Comparative Production Example 1
-1, 80 parts of water-swellable polyurethane, 5 parts of zinc oxide, 1 part of stearic acid, 80 parts of carbon black, and 30 parts of naphthenic oil were kneaded with a Banbury mixer to obtain a blend. After 1 part of sulfur and 2 parts of an accelerator N-cyclohexyl-2-benzothiazolylsulfenamide were compounded on a roll with this compound, the mixture was formed into a belt shape by an extruder.
Vulcanized in an oven at 0 ° C. for 10 minutes.

Examples 4 to 6, Comparative Example 2 80 parts of each of water-swellable polyurethanes AB-1 to 3 and C-1 obtained in Production Examples 1 to 3 and Comparative Production Example 1 were added to 100 parts of chloroprene rubber, and stearic acid. One part, 80 parts of carbon black and 30 parts of dioctyl phthalate were kneaded with a Banbury mixer to obtain a blend. 5 parts of magnesium oxide, 5 parts of zinc oxide, accelerator N,
After blending 2 parts of N'-diethylthiourea, the mixture was formed into a belt shape using an extruder and vulcanized in an oven at 180 ° C. for 10 minutes.

[Performance Test Examples] The tensile properties of the molded products of Examples 1 to 6 and Comparative Examples 1 and 2 are shown in Table 1, and the results of the long-term expansion test and the mass reduction test are shown in Table 2. The test method is as follows. (Mooney viscosity) According to "Physical test method for unvulcanized rubber" described in JIS K6300, a value was measured 4 minutes after preheating for 1 minute using an L-shaped rotor. (Tensile physical properties) Measured with a No. 3 dumbbell test piece according to "Vulcanized Rubber Physical Test Method" described in JIS K6301. (Expansion coefficient) A test piece of 20 × 20 × 2 mm was collected from the strip, and the weight of the test piece when immersed in tap water at 20 ° C. was measured at predetermined time intervals and calculated by the following equation. Expansion coefficient (%) = 100 × (weight after expansion−weight before expansion) / weight before expansion (weight reduction rate) The test piece after measuring the expansion coefficient for 6 months is dried in an oven at 60 ° C. to reduce the weight. Was 0.1 g or less, the weight after drying was calculated as the following equation. Mass reduction rate (%) = 100 × (mass before expansion−mass after drying) / mass before expansion

[0030]

[Table 1]

[0031]

[Table 2]

[0032]

The water-swellable resin composite of the present invention has the following effects. (1) During compounding and kneading, since the isocyanate group of the water-swellable urethane resin is blocked, it is stable without reactivity and can be easily processed on a Banbury mixer and a roll like ordinary rubber. (2)
It can be molded by the usual molding method (extrusion molding, press molding, etc.) with rubber, and the urethane-forming reaction is performed in the rubber at the vulcanization temperature. The elution of the water-absorbing component is remarkably reduced, and stable expansion performance is exhibited over a long period of time. (3) The oxyethylene content of the water-swellable urethane resin and the compounding amount in the rubber,
10 to 300% of its own weight by adjusting the crosslink density of rubber
A water-swellable substance that absorbs water is obtained.

Due to the above effects, the water-swellable resin composite of the present invention can be used as a sealing material for various industrial uses, and is particularly useful as a sealing material for segments and a gasket for construction.

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FI C09K 3/12 C09K 3/12 (72) Inventor Takuji Hashihama 2-2-2-8 Shinomachi, Nishi-ku, Hiroshima-shi Nishikawa Rubber Industries Co., Ltd. (56) References JP-A-4-253720 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08G 18/10, 18/48, 18/80 C08L 21/00, 75/08 C09K 3/12

Claims (8)

(57) [Claims] 1. A water-swellable resin composite obtained by curing and vulcanizing a kneaded product of a polyoxyethylene-based water-swellable polyurethane resin having a blocked isocyanate group and an active hydrogen-containing group and an unvulcanized rubber. 2. The polyoxyethylene-based water-swellable polyurethane resin has at least 30 oxyethylene units.
A partially blocked product of a terminal isocyanate group-containing prepolymer (A) from a polyoxyalkylene polyol (a) and an organic polyisocyanate (b) having a weight percentage of:
The composite according to claim 1, which is obtained by reacting with an active hydrogen-containing compound (B). 3. The composite according to claim 2, wherein (A) is a block copolymer in which 2 to 50% by weight of isocyanate groups of the terminal isocyanate group-containing prepolymer is blocked with a blocking agent (c). 4. The equivalent ratio of the active hydrogen-containing group of (B) to the total of the free isocyanate group and the blocked isocyanate group of (A) is from 0.9 to 2.0.
Or the complex according to 3. 5. The composite according to claim 2, wherein (b) is an aliphatic and / or alicyclic polyisocyanate. 6. The polyoxyethylene-based water-swellable polyurethane resin having a Mooney viscosity of [20 ML (1 + 4) 1].
25 [deg.] C] or higher. 7. A water-stopping material comprising the composite according to any one of claims 1 to 6. 8. A partially blocked isocyanate group-containing prepolymer (A) comprising a polyoxyalkylene polyol (a) having at least 30% by weight of oxyethylene units and an organic polyisocyanate (b), and an active hydrogen-containing compound (B), a kneaded product of a water-swellable polyurethane resin having a blocked isocyanate group and an active hydrogen group and an unvulcanized rubber is regenerated at a rubber vulcanization temperature to obtain a rubber. A method for producing a water-swellable resin composite, comprising curing the polyurethane resin together with vulcanization.