JPS6258396B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a urethane waterproof material. In general, urethane-based waterproofing materials are made of (a) a main ingredient consisting of a urethane prepolymer containing terminal isocyanate groups, and (b) a compound having active hydrogen groups such as polyols and amines, finely powdered silica, talc, carbon, calcium carbonate, etc. Ingredients include inorganic fillers, diluents such as toluene and xylene, catalysts such as lead octylate, cobalt octylate, and stannous octoate, and other additives such as modifiers and plasticizers as necessary. It can be obtained by mixing and coating a hardening agent and a curing agent. The main agent used in these is a viscous liquid with a free NCO2~5% and a viscosity of 5,000~10,000 cps/20℃, and the curing agent is also a viscous liquid with a viscosity of 10,000~5%.
It is a high viscosity liquid of 25000cps/20℃. If the viscosity of the base agent and hardener, especially the hardener, is too high, the viscosity will be high when the base agent and hardener are mixed, making it difficult to mix, making it easy for air to be drawn in during compounding, making it difficult for the air to escape. Badly, it causes pinholes. In addition, incomplete mixing may cause curing failure.
Furthermore, since the load on the metal trowel during coating work is large and the work efficiency is extremely low, it is unavoidable at construction sites to add diluents such as toluene and xylene when mixing the base agent and hardening agent to lower the viscosity and improve mixability and coating. Efforts have been made to improve workability, but this not only has an adverse effect on the waterproof membrane due to shrinkage of the coating, but also poses health and safety issues such as fire danger and poisoning due to inhalation of the diluent. Furthermore, the inorganic filler in the curing agent settles to the bottom in the form of clay during long-term storage, resulting in extremely poor dispersion even after stirring again, which poses a problem. Therefore, there are examples of adding silicone surfactants to the curing agent, but although they are somewhat effective in improving cured physical properties, they are not effective at all in preventing inorganic filler sedimentation and reducing viscosity, and are expensive and unsuitable. It's the economy. In addition, there are methods in which various diluents and the like are added to the curing agent in advance in order to lower the viscosity, but this results in separation of the liquid, deterioration of the physical properties of the coating film, and acceleration of sedimentation of the inorganic filler. The inventors of the present invention have conducted intensive research to improve the above-mentioned drawbacks, and as a result, have come up with the present invention. That is, in a two-component urethane waterproofing material consisting of a main ingredient containing a urethane prepolymer containing terminal isocyanate groups and a curing agent containing a compound having an active hydrogen group, the curing agent is a compound represented by the following general formula. relative to the total weight of the curing agent
It is a two-component urethane waterproofing material containing 0.05 to 5% by weight. General formula: P-UT(-U-P-UT)-n-U-P [wherein, P: has 2 to 8 terminal hydroxyl groups, and contains polyethylene oxide at the end of the molecule or inside the molecule. 5-50 chains
A group obtained by removing the hydroxyl group consumed in forming a urethane bond from a polyether polyol having an average molecular weight of 3000 to 30000 contained in weight%, U: Urethane bond, T: An organic diisocyanate compound excluding the isocyanate group consumed in forming a urethane bond. group, n; 0 to 10] The compound represented by the above general formula of the present invention is blended for the purpose of reducing the viscosity of the curing agent itself and preventing sedimentation of the inorganic filler in the curing agent,
They are compounds having terminal hydroxyl groups obtained by reacting a specific polyether polyol with an organic diisocyanate compound. Specific polyether polyols include polyether polyols having an average molecular weight of 3,000 to 30,000 and having 2 to 8 terminal hydroxyl groups and containing 5 to 50% by weight of polyethylene oxide chains at the ends or inside the molecule. These specific polyether polyols can be obtained by the following method, and the manufacturing method thereof is known.
That is, propylene glycol, ethylene glycol, 1,4 butanediol, 1,6 hexanediol, di- and tripropylene glycol,
di- and triethylene glycol, glycerin,
Trimethylolpropane, diglycerin, pentaerythritol, sorbitol, sugar, aniline, triethanolamine, ethylenediamine,
Starting materials having 2 to 8 active hydrogen groups, such as monoethanolamine, diethanolamine, or intermediates of their alkylene oxide adducts,
After adding a catalyst such as KOH, NaOH, CH ₃ ONa or BF ₃ and heating and dehydrating, alkylene oxide such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, and tetrahydrofuran is added at a temperature of 100 to 130°C and a pressure of 1 to 5 kg/kg. It is obtained by addition polymerization at cm ² G. Ethylene oxide may be added to the end of the molecule under the above reaction conditions, or other alkylene oxides other than ethylene oxide may be added and polymerized first, ethylene oxide may be added to any position during the addition polymerization, and then other alkylene oxides may be added and polymerized at any position during the addition polymerization. These alkylene oxides may be successively addition-polymerized, or ethylene oxide may be mixed with other alkylene oxides and randomly added-polymerized. The number of terminal hydroxyl groups in the specific polyether used in the compound represented by the general formula is preferably 2 to 8, and if it is 1, the structure of the compound represented by the general formula as the object of the present invention cannot be formed. Average molecular weight is 3000~30000 preferably 5000~
25,000, and if it is less than 3,000, the effect of reducing the viscosity of the curing agent and preventing the inorganic filler from settling in the curing agent cannot be obtained even if it is added to the curing agent. Moreover, if it exceeds 30,000, diol will be produced as a by-product in the structure, making it difficult to manufacture and unsuitable. The content of polyethylene oxide chains is preferably from 5 to 30% by weight, and if it is outside this range, even if it is incorporated into the curing agent, it will not be possible to reduce its viscosity or prevent the inorganic filler from settling in the curing agent. Next, as an organic diisocyanate compound, tolylene diisocyanate (2・4100%, 2・4/
2.6 isomer ratios 80/20 and 65/35), naphthalene diisocyanate, diphenylmethane diisocyanate, xylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate, hydrogenated MDI, and other higher aliphatic diisocyanates. Examples include aliphatic, aromatic, or alicyclic diisocyanate compounds alone or in mixtures. The reaction between such a specific polyether polyol and an organic diisocyanate compound is carried out as follows. That is, after thoroughly dehydrating a specific polyether polyol, 0.05 to 0.1% by weight of a catalyst such as triethylene diamine, organic tertiary amines, dibutyltin dilaurate, octoate, lead octylate, cobalt naphthenate, etc. is added to the mixture at room temperature for about 5 to 50% by weight. By mixing for 10 minutes and further mixing at 80 to 100°C for 30 to 60 minutes, the polyol component is completely chain-extended with isocyanate and polymerized. Regarding n in the general formula of the compound represented by the general formula, n is 0 to 10, preferably 0 to 5; if it exceeds 10, polymerization due to chain extension will be difficult to proceed, and stability will be affected. Problematic and prone to gelling. The compound represented by the general formula thus obtained is blended into the curing agent in an amount of 0.05 to 5% by weight, preferably 0.1 to 2% by weight, based on the total weight of the curing agent. Although it is not certain that the compound represented by the general formula of the present invention exhibits excellent effects in reducing the viscosity of the curing agent and preventing sedimentation of the inorganic filler in the curing agent, it is thought to be as follows. It is thought that the compound represented by the general formula plays a role like a kind of surfactant within the curing agent system. That is, the polyethylene oxide chain of the compound represented by the general formula exhibits hydrophilicity, and the other portions exhibit hydrophobicity. Therefore, when a compound represented by the general formula is blended into a curing agent, the hydrophobic moiety is coordinated with the inorganic filler, and compounds with active hydrogen groups such as polyols and amines, diluents, etc. is thought to be coordinated by the hydrophobic part. For this reason, the "wet" contact between the inorganic filler, the compound having an active hydrogen group, and the diluent becomes more complete, and the inorganic filler is surrounded by the compound represented by the general formula. The frictional resistance between the constituent particles is reduced, and this is thought to be effective in reducing the viscosity and preventing the inorganic filler from settling. In two-component urethane waterproofing materials, by blending the compound represented by the general formula of the present invention into the curing agent, it is possible to reduce the viscosity of the curing agent and prevent the inorganic filler in the curing agent from settling. Moreover, the mixing viscosity of the curing agent is low, making the application process using a metal trowel extremely efficient, and furthermore, the curing agent can be stored for a long period of time. Examples of the present invention are listed below. In the examples, "%" and "parts" represent "% by weight" and "parts by weight." Example 1 A mixture of 10 parts of 4,4-methylenebis(2-chloroaniline), 60 parts of carbon, 35 parts of calcium carbonate, 89 parts of dioctyl phthalate, and 6 parts of lead octylate as shown in Table 1 was added as a hardening agent. A test sample was obtained by blending the compound and rolling it twice using three rolls. The viscosity (cps/20°C) of these test samples was measured using BM type rotor No. 4 (60 rpm), and the presence or absence of sedimentation of the inorganic filler was also measured after 6 months and 1 year. On the other hand, the base resin and the above curing agent were blended with the compounds shown in Table 1, and the initial mixing viscosity (cps/20°C) was measured using BM type rotor No. 4 (60 rpm). The physical properties of the coating film were measured. The mixing (weight) ratio of main agent/curing agent at this time is:
1/2 (NCO/NH ₂ equivalent ratio = 1.18) and the compounds shown in Table 1 were ignored. These results are shown in Table 2. The following main ingredients were used. Main ingredient-A: Polyether polyol and tolylene diisocyanate (2/4/2/6 isomer ratio 80/20 ) with terminal isocyanate group-containing urethane prepolymers (however, free NCO3.7
%, viscosity 6000cps/20℃). Main ingredient-B: By reaction between castor oil and polyether polyol, which is a 6/4 mixture of polybutadiene polyol having a terminal hydroxyl group with an average molecular weight of 2300, and tolylene diisocyanate (2.4/2.6 isomer ratio 80/20). The resulting urethane prepolymer containing terminal isocyanate groups (free NCO 3.7%, viscosity 7000 cps/20°C). Example 2 As a curing agent, 40 parts of polyoxypropylene glycol with an average molecular weight of 2000, 35 parts of polyoxypropylene triol with an average molecular weight of 4000, 2 parts of 4,4-methylenebis(2-chloroaniline), and carbon
The same procedure as in Example 1 was carried out by adding the compounds shown in Table 1 to a mixture consisting of 60 parts of calcium carbonate, 35 parts of calcium carbonate, 24 parts of dioctyl phthalate, and 4 parts of lead octylate. The mixing (weight) ratio of main agent/curing agent at this time is 1/2 (NCO/OH equivalent ratio =
1.33, NCO/NH ₂ equivalent ratio = 5.88) and the compounds shown in Table 1 were ignored. These results are shown in Table 3.

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Claims (1)

[Scope of Claims] 1. A two-component urethane waterproofing material consisting of a main component consisting of a urethane prepolymer containing terminal isocyanate groups and a curing agent consisting of a compound having an active hydrogen group, in which the curing agent contains the following general A two-component urethane waterproofing material comprising a compound represented by the formula in an amount of 0.05 to 5% by weight based on the total weight of the curing agent. General formula: P-UT(-U-P-UT)-n-U-P [wherein, P: has 2 to 8 terminal hydroxyl groups, and contains polyethylene oxide at the end of the molecule or inside the molecule. 5-50 chains
A group obtained by removing the hydroxyl group consumed in forming a urethane bond from a polyether polyol having an average molecular weight of 3000 to 30000 contained in weight%, U: Urethane bond, T: An organic diisocyanate compound excluding the isocyanate group consumed in forming a urethane bond. Group, n; 0-10]