JP3023409B2 - Moisture-curable water-swellable polyurethane composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moisture-curable water swelling excellent in storage stability which is used as a waterproof material or a sealing material for preventing water leakage from a concrete joint portion in a tunnel, a joint portion of a fume pipe, or the like. The present invention relates to a water-soluble polyurethane composition.

[0002]

2. Description of the Related Art As a moisture-curable water-swellable polyurethane composition, a composition using a terminal isocyanate group-containing urethane polymer obtained by reacting a polyoxyalkylene polyol containing an oxyethylene group and a polyisocyanate is disclosed in -38750.
This swells the composition utilizing the hydrophilicity of the oxyethylene groups in the urethane polymer. On the other hand, when filling these polyurethane compositions into vertical joints or inclined joints, it is preferable to use a paste-like composition without dripping, and various thixotropic agents are used for this purpose. Colloidal silica is widely used as a thixotropic agent in a composition containing a urethane prepolymer containing a terminal polyisocyanate group as a main component. Colloidal silica is advantageous in that it is inactive against isocyanate and has a small amount of water, so that it can be easily blended into a urethane prepolymer having a terminal isocyanate group. However, when a small amount is added, it is unstable against shear stress such as discharge from a container or molding after filling, while when a large amount is added, thixotropic change after storage is large, and the apparent viscosity is significantly increased. There is a disadvantage that. In particular, when colloidal silica is used as the water-swellable urethane prepolymer containing an oxyethylene group, a large amount of colloidal silica needs to be blended. Therefore, there is a disadvantage that not only the viscosity rise after storage is remarkable, but also it is extremely unstable against shear stress. This is considered to be due to the interaction between oxyethylene groups in the prepolymer and colloidal silica. As a technique for remedying this drawback, a method in which a polymer containing no oxyethylene group is mixed and used is disclosed in Japanese Patent Publication No. 4-71433, but it is not sufficient to obtain storage stability and stable thixotropic properties.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems and to provide a moisture-curable water-swellable polyurethane composition having excellent storage stability.

[0004]

Means for Solving the Problems As a result of studying the above problems, the present inventors have found that a composition comprising a water-swellable urethane prepolymer (A) is reacted with a polyisocyanate and a monoamine to obtain a molecule. It has been found that a composition using a thixotropic agent (B) having a plurality of urea bonds therein exhibits stable thixotropic and is excellent in storage stability. That is, the present invention comprises a water-swellable urethane prepolymer (A) and a thixotropic agent (B) having a plurality of urea bonds in a molecule obtained by reacting a polyisocyanate with a monoamine. (B) is 6 to 15% by weight, preferably 8 to 1% by weight of the liquid component in the composition.
0% by weight. The liquid component in the present invention refers to a component that exhibits fluidity at room temperature, such as a prepolymer and a solvent or a plasticizer that is blended as necessary.

The present invention relates to a polyether polyol represented by the general formula: R-[(OR ₁ ) _m- (OCH ₂ CH ₂ ) _n -OH] _p (1) wherein R is a polyhydric alcohol And OR ₁ is an oxyalkylene group having 3 to 4 carbon atoms, m and n are the degrees of polymerization of the oxyalkylene group and the oxyethylene group, respectively, and m + n is a hydroxyl equivalent of the polyether polyol of 500 to 5000. And p represents an integer of 2 to 4. The content of the oxyethylene group in the total weight of the oxyalkylene group and the oxyethylene group is 50 to 90% by weight.) The NCO group at the terminal obtained by reacting two or more kinds with a polyisocyanate is 1.0 to 10.0.
Water-swellable urethane prepolymer containing 1% by weight (A)
And the general formula

Embedded image Wherein R ₂ is a polyisocyanate-derived polyisocyanate residue, R ₃ and R ₄ are monoamine-derived residues, and one of the groups is hydrogen. And q is an integer of 2 to 4.) and a thixotropic agent (B).

[0006]

Preferred examples of the polyhydric alcohol corresponding to R in the general formula (1) include aliphatic dihydric alcohols (eg, ethylene glycol, propylene glycol, 1,4-butanediol, etc.). , Trihydric alcohols (eg, glycerin, trioxyisobutane, 1,2,3
-Butanetriol, etc.), and tetrahydric alcohols (eg, erythritol, pentaerythritol, 1,2,3,4-pentanetetrol and the like).

The polyether polyol represented by the general formula (1) can be produced by adding alkylene oxide having 3 to 4 carbon atoms and ethylene oxide to the above polyhydric alcohol in a random or block manner by a conventional method. . Examples of the alkylene oxide having 3 to 4 carbon atoms include propylene oxide and butylene oxide.

In producing the water-swellable urethane prepolymer (A), the polyisocyanate to be reacted with the polyether polyol represented by the above general formula (1) may be any of those used in the production of ordinary polyurethane resins. Can be used. That is, it is an aliphatic polyisocyanate, an aromatic polyisocyanate, or an alicyclic polyisocyanate. More specifically, C ₂ -C ₈ linear or branched aliphatic polyisocyanates; benzene-based or naphthalene-based polyisocyanates which are unsubstituted or substituted by halogen or C ₁ -C ₄ alkyl groups [The isocyanate group may be bonded to the aromatic ring directly or via a suitable crosslinking group (for example, a C ₁ -C ₄ alkylene group)]; C ₃ -C ₆
An alicyclic polyisocyanate (the alicyclic group can be substituted by a methyl group, and the isocyanate group is bonded to the cycloalkyl ring directly or via a suitable crosslinking group (for example, a C ₁ -C ₄ alkylene group)) Can be done.] More specifically, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, phenylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, polyphenylmethane polyisocyanate (polymeric MDI), naphthylene-1,5-diisocyanate, triphenyl Methane triisocyanate, diphenylsulfone diisocyanate; and hydrogenated compounds such as
-Methyl-2,4-diisocyanatocyclohexane,
1-methyl-2,6-diisocyanate cyclohexane, dicyclohexylmethane diisocyanate; ethylene diisocyanate, propylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate; dimer of the above diisocyanate (uretdione diisocyanate) Nurate triisocyanate) and the like. These polyisocyanate compounds may be used alone or in combination of two or more.

The water-swellable urethane polymer (A) is produced by reacting the polyether polyol and the polyisocyanate by a conventional method.

The polyisocyanate corresponding to R ₂ in the general formula (2) includes the same polyisocyanates as used in the production of the water-swellable urethane prepolymer (A) described above. Particularly, preferred as the polyisocyanate are arylalkylaryl diisocyanates such as 4,4'-diphenylmethane diisocyanate.

General formula

Embedded image The thixotropic agent (B) having a plurality of urea bonds in the molecule of the polyurea compound represented by
₂ [NCO] _q (where R ₂ is a polyisocyanate residue, q
Represents an integer of 2 to 4. ) Is reacted with a monoamine R ₃ R ₄ NH (wherein R ₃ and R ₄ are monoamine residues, one of which may be hydrogen). That is, the monoamine may be a primary amine or a secondary amine. Specifically, R ₃ and R ₄ are each independently of the other hydrogen, an optionally substituted aliphatic hydrocarbon group, is a alicyclic hydrocarbon group or an aromatic hydrocarbon group, R ₃ and R ₄ And both are not hydrogen at the same time. More particularly, R ₃ and R ₄ independently of one another are hydrogen; a C ₁ -C ₈ linear or branched saturated or unsaturated aliphatic hydrocarbon group; a C ₁ -C ₄ alkyl group is an aryl-substituted C ₁ -C ₄ alkyl group; a halogen atom or C ₁ -C ₄ benzene ring which may be substituted by an alkyl group or a naphthalene ring; alicyclic group which may C ₃ -C ₆ substituted . However, R ₃ and R ₄ are not both hydrogen at the same time. More specifically, aliphatic primary amines (eg, methylamine, ethylamine, propylamine, isopropylamine, butylamine, amylamine, hexylamine, etc.), aliphatic secondary amines (eg, dimethylamine, diethylamine, dipropylamine, Diisopropylamine, dibutylamine, etc.), aliphatic unsaturated amines (eg, allylamine, diallylamine, etc.), alicyclic amines (eg, cyclopropylamine, cyclobutylamine, cyclopentylamine, cyclohexylamine, etc.), aromatic amines (eg, Aniline, diphenylamine, methylaniline, ethylaniline, toluidine, xylidine, benzylamine, naphthylamine, etc.)
And the like. In particular, the monoamine is preferably a monoalkylamine, and more preferably a linear monoalkylamine.

These polyisocyanates and monoamines are each used as a solvent or dioctyl phthalate (DO).
P) or the like, dissolved or dispersed in an isocyanate-inactive liquid medium, and reacted in a conventional manner at an isocyanate group / amino group or imino group ratio of 1.0 to 1.1 to form a plurality of urea bonds in the molecule. To produce a thixotropic agent (B).

[0013] The moisture-curable water-swellable polyurethane composition of the present invention has a thixotropic property having a plurality of urea bonds in a molecule obtained by reacting a water-swellable urethane prepolymer (A) and a polyisocyanate with a monoamine. It is a composition comprising the agent (B), and a swelling ratio can be adjusted by using a non-water-swellable urethane prepolymer in combination, if necessary.
The non-water-swelled urethane prepolymer can be produced by reacting a polyether polyol containing no oxyethylene groups with various polyisocyanates.

Further, the composition can be used by blending various fillers, plasticizers, solvents, additives and the like. As the filler, calcium carbonate, talc, clay, carbon black, titanium oxide, calcium hydroxide, and the like can be used. As the plasticizer, dialkyl phthalate such as dibutyl phthalate, diheptyl phthalate, dioctyl phthalate; dialkyl diadipate such as nonyl adipate can be used. As the solvent, toluene,
Xylene and other hydrocarbon solvents having no active hydroxyl group can be used. As the additive, a curing catalyst, an antioxidant, an ultraviolet absorber, an antioxidant, a silane coupling agent and the like can be used.

[0015]

Next, the present invention will be specifically described with reference to examples and comparative examples. Parts are parts by weight. Example 1 (1) Synthesis of water-swellable urethane prepolymer 360 parts of polyoxyalkylene diol having a weight average molecular weight of 4,000 obtained by copolymerizing propylene glycol with ethylene oxide and propylene oxide (copolymerization ratio of ethylene oxide is 80% by weight). And 80 parts of a polyoxyalkylene triol having a weight average molecular weight of 5,000 (copolymerization ratio of ethylene oxide is 70% by weight) obtained by copolymerizing ethylene oxide and propylene oxide with glycerin, and diphenylmethane diisocyanate 4
By reacting with 9.9 parts at 80 to 85 ° C. for 2 hours, a water-swellable urethane prepolymer having a terminal NCO group content of 1.37% by weight (hereinafter referred to as prepolymer A) was obtained. (2) Synthesis of non-water-swellable urethane prepolymer 360 parts of polyoxypropylene diol having a weight average molecular weight of 3000 obtained by polymerizing propylene oxide with propylene glycol, and polyoxypropylene triol 100 having a weight average molecular weight of 4,000 obtained by polymerizing propylene oxide with glycerin. Is reacted with 59.1 parts of diphenylmethane diisocyanate at 80 to 85 ° C. for 2 hours to obtain a non-water-swellable urethane prepolymer having a terminal NCO group content of 1.18% by weight (hereinafter referred to as prepolymer B).
I got (3) Synthesis of thixotropic agent 100 parts of diphenylmethane diisocyanate was dissolved in 300 parts of dioctyl phthalate, and 55 parts of n-butylamine was added to dioctyl phthalate 3
An amine solution dissolved in 20 parts was added dropwise and reacted at room temperature to obtain a dispersion paste of a thixotropic agent having a plurality of urea bonds in the molecule. This dispersion paste is a composition containing 20% by weight of a thixotropic agent and 80% by weight of dioctyl phthalate. (4) Preparation of Sealing Material Composition With respect to 450 parts of prepolymer A, heavy calcium carbonate 1 was added.
45 parts, rutile type titanium oxide 35 parts, xylene 120
And 410 parts of the above thixotropic agent-dispersed paste were kneaded and dispersed to obtain a sealing material composition.

Example 2 (1) Preparation of Sealing Material Composition To 300 parts of prepolymer A and 150 parts of prepolymer B obtained in Example 1, 145 parts of heavy calcium carbonate, 35 parts of rutile-type titanium oxide, xylene 100
And 390 parts of the above thixotropic agent-dispersed paste were kneaded and dispersed to obtain a sealing material composition.

Example 3 (1) Preparation of Sealant Composition To 180 parts of prepolymer A and 270 parts of prepolymer B obtained in Example 1, 145 parts of heavy calcium carbonate, 35 parts of rutile-type titanium oxide, 100 parts of xylene
And 390 parts of the above thixotropic agent-dispersed paste were kneaded and dispersed to obtain a sealing material composition.

[0018]

Comparative Example A comparative example using only colloidal silica as a thixotropic agent will be described below.

Comparative Example 1 (1) Preparation of Sealing Material Composition Based on 450 parts of the prepolymer A obtained in Example 1, 145 parts of heavy calcium carbonate, 35 parts of rutile type titanium oxide, 120 parts of xylene, and dioctyl phthalate 32
8 parts and 80 parts of colloidal silica were kneaded and dispersed to obtain a sealing material composition.

Comparative Example 2 (1) Preparation of Sealing Material Composition To 300 parts of prepolymer A and 150 parts of prepolymer B obtained in Example 1, 145 parts of heavy calcium carbonate, 35 parts of rutile type titanium oxide, xylene 100
Parts, 328 parts of dioctyl phthalate, and 80 parts of colloidal silica were kneaded and dispersed to obtain a sealing material composition.

The following tests were performed on the moisture-curable compositions of Examples 1 to 4 and Comparative Examples 1 and 2, and the results shown in Table 1 were obtained.

(1) Extrudability JIS A 5758 “Sealants for construction” “4.2.
Extrusion "(measuring temperature 20 ° C).

(2) Slump JIS A 5758 “Sealant for building” “4.3”
Slump (vertical) was measured (measuring temperature 20 ° C.) according to “Slump test”. Furthermore, the slump after the sample was manually kneaded with a gold spatula for about 1 minute was measured in the same manner.

(3) Storage Stability After the composition sealed in a cartridge container was left in an oven at 50 ° C. for 5 days, the extrudability and slump were measured according to the above-mentioned methods.

(4) Water swelling ratio The composition was spread in a sheet having a thickness of 2 mm and cured at room temperature for 7 days. The cured product was cut into 35 × 35 × 2 mm.
The swelling ratio was measured from the volume left after standing in tap water at 20 ° C. for 7 days.

[Table 1]

[0026]

[Test results] The composition using the thixotropic agent of the present invention
It was a stable paste with no run-off and showed good extrudability even after storage.

[0027]

The present invention provides a composition which is useful as a sealing material and a waterproofing material, and particularly useful as a water-stopping material.
By using the composition of the present invention, a moisture-curable water-swellable polyurethane sealing material having excellent storage stability and stable thixotropic properties can be obtained.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A 64-24851 (JP, A) JP-A 51-96848 (JP, A) JP-A 61-14279 (JP, A) JP-A 60-1985 120750 (JP, A) JP-A-53-67733 (JP, A) JP-A-62-169874 (JP, A) JP-A-62-212478 (JP, A) JP-A-3-188177 (JP, A) JP-A-49-99131 (JP, A) U.S. Pat. No. 3,547,848 (US, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 75/00-75/16 C08G 18/00-18 / 87 C09D 5/34 C09D 175/00-175/16 C09J 175/00-175/16 CA (STN) REGISTRY (STN)

Claims (3)

(57) [Claims] A polyether polyol represented by the general formula: R-[(OR ₁ ) _m- (OCH ₂ CH ₂ ) _n -OH] _p (1) (wherein R is a residual polyhydric alcohol) The group, OR ₁ is an oxyalkylene group having 3 to 4 carbon atoms, m and n are the degrees of polymerization of the oxyalkylene group and the oxyethylene group, respectively, and m + n is equivalent to the hydroxyl equivalent of the polyether polyol of 500 to 5000. And p represents an integer of 2 to 4. One or two kinds of oxyethylene groups in the total weight of the oxyalkylene group and the oxyethylene group are 50 to 90% by weight.) A NCO group at a terminal obtained by reacting with the above and a polyisocyanate is 1.0 to 10.0.
Water-swellable urethane prepolymer containing 1% by weight (A)
And the general formula Wherein R ₂ is a polyisocyanate-derived polyisocyanate residue, R ₃ and R ₄ are monoamine-derived residues, and one of the groups is hydrogen. And q represents an integer of 2 to 4.) and a thixotropic agent (B). 2. The composition according to claim 1, wherein the thixotropic agent (B) is contained in an amount of 6 to 15% by weight based on the liquid component in the composition.
A moisture-curable water-swellable polyurethane composition contained. 3. A moisture-curable, water-swellable polyurethane sealing material using the composition according to claim 1.