JPWO2011114849A1 - Organic polyisocyanate composition, water-stopping material-forming composition, and water-swellable water-stopping material - Google Patents

Abstract

It contains an aromatic isocyanate group-terminated prepolymer (a1) and an aliphatic organic polyisocyanate (a2) that is one or more compounds selected from a specific group, and the ratio of the content and number of isocyanate groups is within a predetermined range. This is an organic polyisocyanate composition (A) for moisture-curing water-stopping material. Here, the prepolymer (a1) is a reaction product of an aromatic polyisocyanate (a11) and a polyether polyol (a12), and the polyether polyol (a12) has an oxyethylene group content in a specific range. And a polyether polyol (a12-1) having a nominal average functional group number of 2 and a polyether polyol (a12-1) having a specific range of oxyethylene group content and a nominal average functional group number of 3 Become.

Description

  The present invention relates to an organic polyisocyanate composition, a waterstop material-forming composition, and a water-swellable waterstop material. More specifically, a water-swelling water-stopping material having good curability, water-swelling property, water-stopping property, heat resistance and easy handling properties, and an organic polyisocyanate composition and a water-stopping material-forming composition used therefor About.

  Moisture-cure water-swelling water-stopping materials that are used in a single solution or with the addition of a catalyst are widely used as jointing materials for civil engineering and construction, caulking materials, and steel sheet piles for water-stopping purposes. It is used.

JP 2006-307035 A JP 2001-247642 A Japanese Patent Publication No.53-38750

  However, the water-stopping material disclosed in Patent Document 1 has a problem that the resin deteriorates due to frictional heat generated during the driving operation of the steel sheet pile, and the water-stopping property is lowered.

  Moreover, there exists what disclosed the water-swellable water stop material which mix | blends and uses two liquids, the main agent containing a polyisocyanate group, and the hardening | curing agent containing an active hydrogen group for the purpose of raising durability (patent document 2). .

  However, in the two-component water-stopping material as disclosed in Patent Document 2, not only the mixing work becomes complicated at the time of work at the construction site, but also the above-mentioned 2 due to a mixing error or insufficient stirring. When the liquid is not blended according to the set blending ratio, there is a problem in that sufficient performance cannot be exhibited and the water stop performance is deteriorated due to weakness. In addition, the two-component water-stopping material has a problem that the pot life after blending the two components is shortened.

  Furthermore, the water-swellable water-stopping material disclosed in Patent Document 3 has a problem that heat resistance is insufficient.

  Accordingly, an object of the present invention is to provide a water-swellable water-stopping material that is easy to blend, has excellent heat resistance, and has sufficient durability against frictional heat, and an organic polyisocyanate composition and a water-stopping material-forming composition used therefor. To provide things.

  The inventors of the present invention have arrived at the present invention as a result of intensive studies to solve the problems in the conventional water-swellable water-stopping material.

That is, the present invention includes the following (1) to (10).
(1) Organic for moisture-curing water-stopping material having an isocyanate group content of 0.5 to 15% by mass and containing an aromatic isocyanate group-terminated prepolymer (a1) and an aliphatic organic polyisocyanate (a2) A polyisocyanate composition (A) comprising:
The aromatic isocyanate group-terminated prepolymer (a1) is a reaction product of an aromatic polyisocyanate (a11) and a polyether polyol (a12),
The polyether polyol (a12) has a nominal average functional group number of 2 and an oxyethylene group content in the polyoxyalkylene chain of 50 to 100% by mass, and a nominal average functional group number of And a polyether polyol (a12-2) having an oxyethylene group content in the polyoxyalkylene chain of 50 to 100% by mass,
The aliphatic organic polyisocyanate (a2) is an isocyanurate group-containing organic polyisocyanate (a21), an allophanate group-containing organic polyisocyanate (a22), and an activity in which the number of functional groups is 2-3 and the molecular weight is 300 or less. One or more compounds selected from the group consisting of a reaction product (a23) of a hydrogen group-containing compound and an aliphatic diisocyanate,
And,
The ratio of the isocyanate group of the aromatic isocyanate group-terminated prepolymer (a1) to the isocyanate group of the aliphatic organic polyisocyanate (a2) (number of isocyanate groups in a1: number of isocyanate groups in a2) is 8: The organic polyisocyanate composition (A) which is 1-1: 4.
(2) Organic polyisocyanate composition (A) as described in said (1) whose isocyanate group content in the said aliphatic organic polyisocyanate (a2) is 5-50 mass%.
(3) Organic polyisocyanate composition (A) as described in said (1) or (2) whose isocyanate group content in the said aliphatic organic polyisocyanate (a2) is 5-40 mass%.
(4) The organic polyisocyanate composition (A) according to any one of (1) to (3), wherein the polyether polyol (a12) has a number average molecular weight of 200 to 8,000.
(5) In the polyether polyol (a12), the mass ratio (a12-1: a12-2) of the polyether polyol (a12-1) to the polyether polyol (a12-2) is 2: 1 to 40. The organic polyisocyanate composition (A) according to any one of (1) to (4),
(6) Ratio of the isocyanate group of the aromatic isocyanate group-terminated prepolymer (a1) to the isocyanate group of the aliphatic organic polyisocyanate (a2) (number of isocyanate groups in a1: number of isocyanate groups in a2) The organic polyisocyanate composition (A) according to any one of (1) to (5), wherein is 6: 1 to 1: 1.
(7) The organic polyisocyanate composition (A) according to any one of (1) to (6), further including a plasticizer (B).
(8) A water-stopping material-forming composition containing the organic polyisocyanate composition (A) and the catalyst (C) according to any one of (1) to (7).
(9) A water-stopping material-forming composition containing the organic polyisocyanate composition (A), the plasticizer (B), and the catalyst (C) according to any one of (1) to (7). .
(10) A water-swellable water-stopping material using the water-stopping material-forming composition according to (8) or (9).

  EFFECT OF THE INVENTION According to the present invention, a water-swellable water-stopping material that is easy to blend, has excellent heat resistance, and has sufficient durability even when frictional heat is applied, and an organic polyisocyanate composition and a water-stopping material-forming composition used therefor Can be provided.

  The aromatic isocyanate group-terminated prepolymer (a1) used in the present invention has one or two or more kinds of aromatic polyisocyanate (a11) and oxyethylene group content in the polyoxyalkylene chain of 50 to 100% by mass. This is a terminal isocyanate group-containing urethane prepolymer having an isocyanate group content of 0.5 to 15% by mass obtained by reacting with a polyether polyol (a12).

  As the aromatic polyisocyanate (a11), known aromatic polyisocyanates can be used. Specifically, for example, known 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate (hereinafter, tolylene diisocyanate is abbreviated as TDI), xylene-1,4-diisocyanate, xylene-1,3- Diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 2,2′-diphenylmethane diisocyanate, 4,4′-diphenylether diisocyanate, polymethylene polyphenylene polyisocyanate (hereinafter abbreviated as polymeric MDI), 2- Nitrodiphenyl-4,4′-diisocyanate, 2,2′-diphenylpropane-4,4′-diisocyanate, 3,3′-dimethyldiphenylmethane-4,4′-diisocyanate, 4,4′-diphenylpropyl Aromatic diisocyanates such as pan diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, naphthylene-1,4-diisocyanate, naphthylene-1,5-diisocyanate, 3,3′-dimethoxydiphenyl-4,4′-diisocyanate, and , Polymers of these aromatic diisocyanates, polymeric materials, and mixtures of two or more of these. Among these, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4′-difelmethane diisocyanate, 2,4′-difelmethane diisocyanate and mixtures thereof have a high reaction rate, And it is preferable for the reason that physical properties are good.

The polyether polyol (a12) is a polyether polyol having a polyoxyalkylene chain in which the ratio of oxyethylene groups in the polyoxyalkylene chain is 50 to 100% by mass. By using this polyether polyol (a12), it is possible to obtain an isocyanate group-terminated prepolymer having excellent hydrophilicity. When the ratio of the polyoxyethylene group is less than 50% by mass, there is a problem in that a water-stopping material having sufficient water expandability cannot be obtained. The polyether polyol (a12) is preferably represented by the general formula R [— (OR ¹ ) _n OH] _p (where R is a polyhydric alcohol residue, (OR ¹ ) _n is an oxyethylene group and 3 to 3 carbon atoms. A polyoxyalkylene chain composed of 4 alkylene groups (wherein the proportion of oxyethylene groups occupies 50 to 100% by mass of the mass of the polyoxyalkylene chains), and n is a number indicating the degree of polymerization of the oxyalkylene groups. The number corresponding to the number average molecular weight of the polyol is 200 to 8,000, and p is a number of 2 to 8), or a mixture of two or more polyether polyols.

  Examples of the polyhydric alcohol include dihydric alcohols (ethylene glycol, propylene alcohol, etc.), trihydric alcohols (glycerin, trimethylolpropane, etc.), tetrahydric alcohols (erythritol, pentaerythritol, etc.), pentahydric alcohols (Arhat, xylit, etc. Etc.) and hexavalent alcohol (Sorbit, Mannich etc.).

  The polyether polyol (a12) has a nominal average functional group number of 2 and an oxyethylene group content in the polyoxyalkylene chain of 50 to 100% by mass, and a nominal average functional group number of 3 It is a polyether polyol (a12-2) having an oxyethylene group content in the polyoxyalkylene chain of 50 to 100% by mass, which makes it easy to balance the viscosity and the crosslinking density. It is preferable from a viewpoint that a thing is obtained.

  In the present invention, the nominal average functional group number refers to the number of functional groups per molecule of an initiator such as a polyhydric alcohol used when obtaining a polyether polyol (the number of active hydrogen atoms per molecule of the initiator). .

  In the polyether polyol (a12), the proportion of the polyether polyol (a12-1) and the polyether polyol (a12-2) used is not particularly limited, but the mass ratio (a12-1: a12-2) is It is good that it is 2: 1-40: 1. If the ratio of the polyether polyol (a12-2) is less than the lower limit, the crosslinking density of the water-stopping material is lowered, so that the strength tends to be lowered. When the ratio of the polyether polyol (a12-2) exceeds the upper limit, the viscosity of the isocyanate group-terminated prepolymer is increased and workability is liable to be deteriorated.

  The aromatic isocyanate group-terminated prepolymer (a1) used in the present invention comprises the polyether polyol (a12) and the aromatic polyisocyanate (a11) as active hydrogen groups derived from the polyether polyol (a12). Is obtained by reacting the aromatic polyisocyanate (a11) -derived isocyanate group (NCO group) in an excessive amount. The ratio of the isocyanate group to the active hydrogen group (number of isocyanate groups: number of active hydrogen groups) is preferably 1.1: 1 to 3: 1. In addition, as the reaction method, a known method can be appropriately employed. For example, a mixture of the aromatic polyisocyanate (a11) and the polyether polyol (a12) is obtained at 40 to 100 ° C. for 1 to 48 hours. The method of making it react is mentioned.

  The isocyanate group (NCO group) content in the aromatic isocyanate group-terminated prepolymer (a1) is preferably 0.5 to 15% by mass, and more preferably 1.0 to 5% by mass. When the isocyanate group content is less than 0.5% by mass, the molecular weight becomes too large, so there is a problem that the viscosity of the isocyanate group-terminated prepolymer becomes high, and when it exceeds 15% by mass, when reacting with moisture in the air, Since the amount of carbon dioxide generated is too large, there is a problem that air bubbles increase in the water stop material obtained after curing.

  The aliphatic organic polyisocyanate (a2) used in the present invention has an isocyanurate group-containing organic polyisocyanate (a21), an allophanate group-containing organic polyisocyanate (a22), and the number of functional groups is 2 to 3, and the molecular weight is 300. One or more compounds selected from the group consisting of a reaction product (a23) of an active hydrogen group-containing compound and an aliphatic diisocyanate, which are the following.

  Examples of the isocyanurate group-containing organic polyisocyanate (a21) include aliphatic diisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate (hereinafter abbreviated as HDI), 3-methyl-1,5-pentane diisocyanate, and lysine diisocyanate; Hydrogenated tolylene diisocyanate; Hydrogenated xylene diisocyanate; Hydrogenated diphenylmethane diisocyanate; Tetramethylxylene diisocyanate; Starting from aliphatic diisocyanates such as norbornene diisocyanate, an isocyanuration catalyst is added according to a known synthesis method. It is obtained by polymerizing the isocyanate group of the aliphatic diisocyanate. As the polymerization method, a known method can be appropriately employed. For example, first, the mixture of the aliphatic diisocyanate and the isocyanuration catalyst is stirred at 40 to 150 ° C. for 1 to 10 hours, Examples include a method in which the isocyanurate-forming catalyst is deactivated, and the unreacted aliphatic diisocyanate is removed by distillation as necessary. Examples of the isocyanurate-forming catalyst include organometallic compounds such as potassium acetate, quaternary ammonium salts and the like. The addition amount of such an isocyanurate-forming catalyst is preferably 0.0001 to 0.1 parts by mass with respect to 100 parts by mass of the aliphatic diisocyanate.

  The allophanate group-containing organic polyisocyanate (a22) includes the aliphatic diisocyanate, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, cyclohexanol, 2-ethylhexanol, and tridecanol. , Ethylene glycol, 1,2-propylene glycol, 1,4-butanediol, 1,3-butanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, diethylene glycol, dipropylene glycol, trimethylolpropane, Using an active hydrogen group-containing compound having 1 to 3 functional groups (number of active hydrogen groups) such as glycerin and a molecular weight of 300 or less as a raw material, an allophanate catalyst is added and reacted according to a known synthesis method. By It is. The molecular weight of the active hydrogen group-containing compound is preferably 32 to 300. As the synthesis method, a known method can be appropriately employed. For example, first, a mixture in which a mass ratio of the aliphatic diisocyanate and the active hydrogen group-containing compound is 95: 5 to 60:40. The allophanatization catalyst is added to and stirred at 90 to 150 ° C. for 1 to 10 hours. Then, the allophanate catalyst is deactivated, and the unreacted aliphatic diisocyanate is removed by distillation as necessary. A method is mentioned. Examples of the allophanatization catalyst include organometallic compounds such as tin octylate, and the addition amount of the allophanate catalyst is 0 with respect to 100 parts by mass of the mixture of the aliphatic diisocyanate and the active hydrogen group-containing compound. It is preferable that it is 0.0001-0.1 mass part.

  Moreover, the reaction product (a23) of the active hydrogen group-containing compound and the aliphatic diisocyanate is the same aliphatic diisocyanate as described above, ethylene glycol, 1,2-propylene glycol, 1,4-butanediol, 1,3-butanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, diethylene glycol, dipropylene glycol, trimethylol propane, glycerin and the like have 2 to 3 functional groups (number of active hydrogen groups) and a molecular weight. It is obtained by reacting with an active hydrogen group-containing compound that is 300 or less. The molecular weight of the active hydrogen group-containing compound is preferably 62 to 300. In addition, as the reaction method, for example, first, the aliphatic diisocyanate and the active hydrogen group-containing compound are mixed at a mass ratio of 90:10 to 60:40 and stirred at 40 to 100 ° C. for 1 to 10 hours. Then, a method of distilling off the unreacted aliphatic diisocyanate as necessary is exemplified.

  The aliphatic organic polyisocyanate (a2) includes the isocyanurate group-containing organic polyisocyanate (a21), the allophanate group-containing organic polyisocyanate (a22), and the number of functional groups of 2 to 3, and a molecular weight of 300. After synthesizing the reaction product (a23) of the following active hydrogen group-containing compound and aliphatic diisocyanate, these may be used alone or in combination of two or more at any ratio. Two or more of these may be synthesized and used simultaneously.

  The isocyanate group (NCO group) content in the aliphatic organic polyisocyanate (a2) is preferably 5 to 50% by mass, and more preferably 10 to 40% by mass. When the isocyanate group content is less than 5% by mass, the molecular weight becomes too large and the blending amount with respect to the aromatic isocyanate group-terminated prepolymer (a1) increases, so that the magnification when the water-stopping material expands with water is increased. There is a problem that the gap between the steel sheet piles may not be filled, and if it exceeds 40% by mass, the molecule of the organic polyisocyanate becomes small, so that it tends to volatilize and there is a problem that the odor is tight.

  In the organic polyisocyanate composition (A) of the present invention, the ratio of the aromatic isocyanate group-terminated prepolymer (a1) to the aliphatic organic polyisocyanate (a2) is determined by the aromatic isocyanate group-terminated prepolymer ( The ratio of the isocyanate group of a1) to the isocyanate group of the aliphatic organic polyisocyanate (a2) (number of isocyanate groups of a1: number of isocyanate groups of a2) is 8: 1 to 1: 4, preferably , 6: 1 to 1: 1. When the amount of the aromatic isocyanate group-terminated prepolymer (a1) is larger than the above range, the strength, heat resistance, and consequently water-stop properties of the water-stopping material are likely to be adversely affected. When the amount of the aliphatic organic polyisocyanate (a2) is larger than the above range, the magnification when the water-stopping material expands with water becomes low, so that there is a possibility that the gap between the steel sheet piles cannot be filled.

  In the organic polyisocyanate composition (A) of the present invention, other known stabilizers such as other phosphate esters (trade name JP-508, manufactured by Johoku Chemical Industry Co., Ltd.) and antifoaming agents (trade name BYK-A535, Big Chemie) Manufactured) and additives such as plasticizers can be further contained. By using a stabilizer, the storage stability becomes longer, and by using an antifoaming agent, bubbles in the water-stopping material after curing are reduced, so that the strength of the water-stopping material is improved.

  As the plasticizer (B) used in the organic polyisocyanate composition (A) of the present invention, a known plasticizer can be used. For example, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, Di-2-ethylhexyl phthalate, diisononyl phthalate, diisodecyl phthalate, butyl benzyl phthalate, diethyl adipate, dibutyl adipate, dihexyl adipate, diethylhexyl adipate, diisononyl adipate, diisodecyl adipate, bis (adipate) Butyl diglycol), diethyl sebacate, dibutyl sebacate, dihexyl sebacate, di-2-ethylhexyl sebacate, dimethyl maleate, diethyl maleate, dibutyl maleate, dihexyl maleate, di-2-ethyl maleate Ester compounds such as hexyl, diisononyl maleate, diisodecyl maleate; phosphate compounds such as tributyl phosphate, tri-2-ethylhexyl phosphate, triphenyl phosphate, tricresyl phosphate; 1-phenyl-1-xylylethane, 1 There are aromatic hydrocarbon compounds such as -phenyl-1-ethylphenylethane, and these can be used alone or in combination of two or more. Among these, 1-phenyl-1-xylylethane, 1-phenyl-1-ethylphenylethane, and diisodecyl phthalate are preferable because a water-stopping material having good hydrolysis resistance can be obtained.

  In the organic polyisocyanate composition (A) of the present invention, the proportion of the plasticizer (B) is not particularly limited, but preferably the mass of the plasticizer (B) is the aromatic isocyanate group-terminated prepolymer (a1). And the aliphatic organic polyisocyanate (a2) in an amount not exceeding the total mass. If the proportion of the plasticizer (B) is too large, the magnification when the water-stopping material expands with water becomes low, and thus there is a possibility that the gap between the steel sheet piles cannot be filled.

  The water-stopping material-forming composition of the present invention includes the organic polyisocyanate composition (A) and the catalyst (C), or the organic polyisocyanate composition (A), the plasticizer (B), and the catalyst (C). Containing.

  As the catalyst (C), any conventional catalyst that promotes the urethanization reaction can be used. For example, triethylenediamine, bis (N, Ndimethylamino-2-ethyl) ether, N, N, N ′, Tertiary amines such as N′-tetramethylhexamethylenediamine and carboxylates thereof; aromatic amines such as 1-methylimidazole, 1,2-dimethylimidazole and 1-isobutyl-2-methylimidazole and carboxylates thereof; Examples thereof include carboxylic acid metal salts such as potassium acetate, potassium octylate and tin octylate, and organic metal compounds such as dibutyltin laurate.

  In the waterstop material-forming composition of the present invention, the amount of the catalyst (C) used is preferably 0.01 to 5 parts by mass, more preferably 100 parts by mass of the organic polyisocyanate composition (A) of the present invention. Is 0.02 to 2 parts by mass. If the amount of the catalyst (C) used is less than the above range, the curing time cannot be shortened and the effect is small. If it is more than the above range, the curing time after blending is shortened, which may cause problems in workability. .

  The plasticizer (B) used in the water-stopping material-forming composition of the present invention is as described in the organic polyisocyanate composition (A) of the present invention. In the water-stopping material-forming composition, the ratio of the organic polyisocyanate (A) of the present invention to the plasticizer (B) is not particularly limited, but preferably the mass of the plasticizer (B) is the present invention. It is good to set it as the quantity which does not exceed the total mass of the said aromatic isocyanate group terminal prepolymer (a1) and the said aliphatic organic polyisocyanate (a2) in organic polyisocyanate (A). If the proportion of the plasticizer (B) is too large, the magnification when the water-stopping material formed is expanded with water is low, and therefore there is a possibility that the gap between the steel sheet piles cannot be filled.

  The water-swellable water-stopping material of the present invention can be obtained by curing the water-stopping material-forming composition. As a curing method, a known method can be appropriately adopted. For example, a method of leaving the water-stopping material-forming composition in air at 0 to 40 ° C. for 1 to 96 hours can be mentioned.

[Synthesis Example 1: Isocyanate group-terminated prepolymer P1]
A reactor equipped with a stirrer, a cooling pipe, a nitrogen introduction pipe, and a thermometer was purged with nitrogen, and then TDI (Nippon Polyurethane Industry Co., Ltd., trade name “T-80”, NCO group content 48.2 mass) was added to the reactor. %) Was charged with 5.8 g of an aromatic hydrocarbon compound (manufactured by Nippon Oil Corporation, trade name “Nisseki Hysol SAS-296”) as a plasticizer. Next, 564 g of the following polyol A and 141 g of the following polyol B were charged into the reactor while stirring at room temperature and reacted at 80 ° C. to 90 ° C. for 15 hours to obtain an isocyanate group (NCO group) content of 1.5. An isocyanate group-terminated prepolymer “P1” having a mass% and a viscosity of 2,700 mPa · s at 25 ° C. was obtained.

[Synthesis Example 2: Isocyanate group-terminated prepolymer P2]
After replacing the reactor equipped with a stirrer, a cooling pipe, a nitrogen introducing pipe and a thermometer with nitrogen, 60.0 g of TDI (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name “T-80”) was used as a plasticizer. 229 g of an aromatic hydrocarbon compound (manufactured by Shin Nippon Oil Co., Ltd., trade name “Nisseki Hysol SAS-296”) was charged. Next, 646 g of the following polyol A and 65 g of the following polyol B were charged into the reactor while stirring at room temperature and reacted at 80 ° C. to 90 ° C. for 15 hours to obtain an isocyanate group (NCO group) content of 1.5. An isocyanate group-terminated prepolymer “P2” having a mass% and a viscosity of 2,500 mPa · s at 25 ° C. was obtained.

<Raw material 1>
Polyol A: PB-5064 manufactured by Toho Chemical Industry, ethylene oxide (EO) / propylene oxide (PO) adduct, EO / PO (mass ratio) = 70/30, hydroxyl value = 22, number of functional groups per molecule of initiator = 2
Polyol B: GRB-2543 manufactured by Toho Chemical Industry, ethylene oxide (EO) / propylene oxide (PO) adduct, EO / PO (mass ratio) = 50/50, hydroxyl value = 72, number of functional groups per molecule of initiator = 3.

[Polyisocyanate composition formulation example]
A reactor equipped with a stirrer, a cooling pipe, a nitrogen introducing pipe, and a thermometer was purged with nitrogen, and then 500 g of P1 obtained in Synthesis Example 1 and an HDI trimerization product (manufactured by Nippon Polyurethane Industry Co., Ltd.) , 17.9 g (P1 / Coronate HX = 2/1 in terms of the molar ratio of NCO groups) of 17.9 g (trade name “Coronate HX”, NCO group content 21.3 mass%), stirred at room temperature for 2 hours, and the main agent (poly Isocyanate composition) “S1” was obtained.
Further, using “P1” and “P2” obtained in Synthesis Examples 1 and 2 as the isocyanate group-terminated prepolymer (prepolymer), the above-mentioned trimerized HDI as the organic polyisocyanate (organic isocyanate) and the following raw material 2 Each component was mixed and stirred in the combinations and blending ratios shown in Table 1 until uniform at room temperature to obtain main agents “S2” to “S13”. The isocyanate group-terminated prepolymer “P1” was directly used as the main agent “S14”, and the isocyanate group-terminated prepolymer “P2” was used as the main agent “S15”.

<Raw material 2>
C-2770: Allophanate of HDI (manufactured by Nippon Polyurethane Industry Co., Ltd., NCO group content 19.4% by mass)
C-HL: Adduct body of HDI (Nippon Polyurethane Industry Co., Ltd., NCO group content 12.8% by mass)
MR-200: Polymeric MDI (manufactured by Nippon Polyurethane Industry Co., Ltd., NCO group content 30.7% by mass).

[Additive example]
A reactor equipped with a stirrer, a cooling pipe, a nitrogen introducing pipe, and a thermometer was purged with nitrogen, and then 950 g of diisodecyl phthalate (trade name DIDP, manufactured by Daihachi Chemical Industry Co., Ltd.) and Kao Riser No. 300 g of imidazole catalyst (manufactured by Kao Corporation) was charged and stirred at room temperature for 2 hours to obtain an additive “K1”.

<Examples 1 to 11>
After mixing the main agents “S1” to “S10” obtained in the blending example of the polyisocyanate composition and the additive “K1” obtained in the blending example of the additive in the combinations and blending ratios shown in Table 2, respectively. Pour into a plastic tray with a length of 19 cm, a width of 10 cm, and a depth of 2 cm, placed on a horizontal table, to a thickness of 2 mm, and let stand at 25 ° C. for 48 hours. To “R11”, which were taken as Examples 1 to 11, respectively.

<Comparative Examples 1-7>
Except having used "S11"-"S15" as a main ingredient, it carried out similarly to Examples 1-11, and obtained the water-stop material "R12"-"R18" of a cured film form, and these were comparative examples 1-7 in order, respectively. It was.

[Test method for tensile strength after water swelling (curing at room temperature)]
After the water-stopping materials obtained in Examples and Comparative Examples were each immersed in ion-exchanged water at 25 ° C. for 24 hours, they were punched with a JIS No. 2 dumbbell according to JIS K6251, and the tensile strength was measured at 300 mm / min as a test piece. did. The results are shown in Table 2.
Tensile strength after water swelling: 3N or more is acceptable.

[Tensile strength after water swelling (after heat abuse) test method]
The water-stopping materials obtained in Examples and Comparative Examples were each heated in a dryer heated to 180 ° C. for 20 minutes. Next, after being immersed in ion-exchanged water at 25 ° C. for 24 hours, it was punched with a JIS No. 2 dumbbell according to JIS K6251, and the tensile strength was measured at 300 mm / min using this as a test piece. The results are shown in Table 2.
Tensile strength after water swelling: 3N or more is acceptable.

[Method for measuring volume swelling ratio]
The waterstop materials obtained in the examples and comparative examples were each cut into a square with a side of 70 mm. Next, after immersing in ion-exchanged water at 25 ° C. for 24 hours, the length, width, and thickness were measured, and the magnification with respect to the volume before immersion was calculated. The results are shown in Table 2.
Volume swelling ratio: 3 times or more is accepted.

  In the waterstop material of the present invention obtained by adding the aliphatic organic polyisocyanate (a2) to the aromatic isocyanate group-terminated prepolymer (a1), there is a difference in the reaction rate of the isocyanate group in each compound. First, the isocyanate group of the fast-reacting aromatic isocyanate-terminated prepolymer (a1) reacts with moisture taken in from the air to become amino-terminated terminals, and then the slow-reacting aliphatic organic polyisocyanate (a2) ) Has a stepwise cross-linking effect in which the isocyanate group reacts with the amino group terminal to form a urea bond, so that, as shown in Table 2, high tensile strength after water swelling is present even after heat abuse. can get. On the other hand, since the water-stopping material to which the aliphatic organic polyisocyanate (a2) is not added has no difference in the reaction rate of the isocyanate group, the reaction between the isocyanate group and moisture is performed simultaneously. As a result, since the cross-linking effect in which the amino group which is a reaction product of water and isocyanate group and the unreacted isocyanate group further react is reduced, the tensile strength after water swelling after heating abuse is lowered. Moreover, the thing with little addition amount of the said aliphatic organic polyisocyanate (a2) has inferior tensile strength after water swelling both after room temperature curing and after heat abuse. Furthermore, when the amount of the aliphatic organic polyisocyanate (a2) added is too large, the content of the isocyanate group-terminated prepolymer and the content of the oxyethylene group are relatively decreased, so that the volume swelling ratio is decreased. . The addition of aromatic polyisocyanate in place of the aliphatic organic polyisocyanate (a2) provides a certain degree of tensile strength after water swelling after curing at room temperature. Since the group urea bond is more likely to occur, the decrease in tensile strength after water swelling after heat abuse is significant.

  As described above, according to the present invention, a water-swellable water-stopping material that is easy to blend, has excellent heat resistance, and has sufficient durability even when frictional heat is applied, and an organic polyisocyanate composition used therefor In addition, it is possible to provide a water-stopping material-forming composition. Therefore, the organic polyisocyanate composition, the water-stopping material-forming composition, and the water-swellable water-stopping material of the present invention are a joint material, a caulking material, and a steel sheet pile for civil engineering and building applications for the purpose of water stoppage. It can be preferably used for water materials.

Claims (10)

Organic polyisocyanate composition for moisture-curing waterstop materials having an isocyanate group content of 0.5 to 15% by mass and containing an aromatic isocyanate group-terminated prepolymer (a1) and an aliphatic organic polyisocyanate (a2) An object (A),
The aromatic isocyanate group-terminated prepolymer (a1) is a reaction product of an aromatic polyisocyanate (a11) and a polyether polyol (a12),
The polyether polyol (a12) has a nominal average functional group number of 2 and an oxyethylene group content in the polyoxyalkylene chain of 50 to 100% by mass, and a nominal average functional group number of And a polyether polyol (a12-2) having an oxyethylene group content in the polyoxyalkylene chain of 50 to 100% by mass,
The aliphatic organic polyisocyanate (a2) is an isocyanurate group-containing organic polyisocyanate (a21), an allophanate group-containing organic polyisocyanate (a22), and an activity in which the number of functional groups is 2-3 and the molecular weight is 300 or less. One or more compounds selected from the group consisting of a reaction product (a23) of a hydrogen group-containing compound and an aliphatic diisocyanate,
And,
The ratio of the isocyanate group of the aromatic isocyanate group-terminated prepolymer (a1) to the isocyanate group of the aliphatic organic polyisocyanate (a2) (number of isocyanate groups in a1: number of isocyanate groups in a2) is 8: The organic polyisocyanate composition (A) which is 1-1: 4.   The organic polyisocyanate composition (A) according to claim 1, wherein an isocyanate group content in the aliphatic organic polyisocyanate (a2) is 5 to 50% by mass.   The organic polyisocyanate composition (A) according to claim 1 or 2, wherein an isocyanate group content in the aliphatic organic polyisocyanate (a2) is 5 to 40% by mass.   The organic polyisocyanate composition (A) according to any one of claims 1 to 3, wherein the polyether polyol (a12) has a number average molecular weight of 200 to 8,000.   In the polyether polyol (a12), the mass ratio (a12-1: a12-2) of the polyether polyol (a12-1) to the polyether polyol (a12-2) is 2: 1 to 40: 1. The organic polyisocyanate composition (A) according to any one of claims 1 to 4.   The ratio of the isocyanate groups of the aromatic isocyanate group-terminated prepolymer (a1) to the isocyanate groups of the aliphatic organic polyisocyanate (a2) (number of isocyanate groups in a1: number of isocyanate groups in a2) is 6: The organic polyisocyanate composition (A) according to any one of claims 1 to 5, which is 1-1: 1.   The organic polyisocyanate composition (A) according to any one of claims 1 to 6, further comprising a plasticizer (B).   A water-stopping material-forming composition comprising the organic polyisocyanate composition (A) and the catalyst (C) according to any one of claims 1 to 7.   A water-stopping material-forming composition comprising the organic polyisocyanate composition (A) according to any one of claims 1 to 7, a plasticizer (B), and a catalyst (C).   A water-swellable water-stopping material using the water-stopping material-forming composition according to claim 8 or 9.