JPH0548259B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to polyurethane, particularly to a urethane composition with improved thixotropy for use as a civil engineering and construction material. (Prior technology) The prepolymer with an NCO group at the end, which is an intermediate of polyurethane, reacts with moisture in the air and turns into an elastic body. Utilizing this property, the prepolymer can be used as it is or mixed with a filler, etc. The urethane composition obtained can be used as caulking material, sealing material,
As civil engineering and construction materials such as adhesives, dam construction,
It is widely used in the construction work of buildings and houses to fill in cracks, joints, and around sash, and to bond parts together. (Problems to be Solved by the Invention) When applying sealants, caulking materials, adhesives, etc. to vertical surfaces such as walls and ceilings, and downward facing surfaces, they must have fluidity at the time of application, and at the same time, harden after application. It is necessary to have thixotropy to maintain the shape of the material so that it does not sag until it changes into an elastic body. In order to impart this thixotropic property, it is known to add amorphous fine powdered dry silica, plastisol of vinyl chloride, etc.
4746, Japanese Unexamined Patent Publication No. 50-80354, etc.). The effectiveness of these thixotropic agents depends on the amount and type of filler, and is also greatly affected by variations in the quality of the filler, which often causes problems during construction, which is a serious problem. ing. (Means for solving the problem) As a result of various studies to improve this thixotropic property, we found that if a mixture of a polyurethane prepolymer and a filler is reacted with water and then a thixotropic agent is mixed in, a strong thixotropic property can be obtained. The present invention was achieved by finding that this is expressed. That is, the present invention is as follows. (1) 2 to 30% by weight of NCO at the ends generated by the reaction between polyol and organic polyisocyanate
The following formula (1) The amount used (parts by weight), M is the NCO group content of the prepolymer (% by weight), and Y is the amount of water (parts by weight) contained in the filler and thixotropic agent. and a urethane composition with improved thixotropy, which is characterized by adding and kneading a thixotropy imparting agent. The polyols used in the present invention include water, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,3- and 1,4-butanediol, 4,4'-dihydroxydiphenylpropane, 4,4'-dihydroxydiphenylpropane, and 4,4'-dihydroxydiphenylpropane. Addition of alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide to enylmethane, glycerin, 1,2,6-hexanetriol, 1,1,1,-trimethylolpropane, pentaerythrite, sorbitol, sucrose, etc. It is a polyether polyol obtained by polymerization. Other polytetramethylene ether polyols, polymer polyols, and polybutadiene polyols can also be used. The molecular weight of these polyols is suitably between 300 and 6,000, and they may be used singly or in combination of two or more. In addition, as necessary, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, neopentyl glycol, triethylene glycol, tripropylene glycol, 1,3- and 1,4-butanediol, bishydroxyethylhydroquinone, glycerin,
1,2,6-hexanetriol, 1,1,1-
Trimethylolpropane, pentaerythritol,
Low molecular weight polyhydric alcohols such as diglycerin can also be added. Examples of the organic polyisocyanate used in the present invention include 2,4-tolylene diisocyanate, 2,
6-Tolylene diisocyanate, and mixtures thereof, crude tolylene diisocyanate, 4,4'-
Diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, and mixtures of both, polymethylene polyphenyl polyisocyanate (crude diphenylmethane diisocyanate),
These include xylylene diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, hexahydroxylylene diisocyanate, and carbodiimide modified products, dimers, trimers, etc. of these polyisocyanates. The amount of organic polyisocyanate used is such that the NCO group content of the polyurethane prepolymer produced by the reaction with polyol and polyhydric alcohol is 2 to 30% by weight, and the suitable NCO group content is adjusted depending on the purpose of use. Ru. If it is less than 2% by weight or more than 30% by weight, the physical properties of the product will deteriorate. Inorganic and organic fillers used in the present invention include, for example, calcium carbonate, talc, clay, kaolin, aluminum hydroxide, barium hydroxide, barium sulfate, calcium sulfate, asbestos, glass fiber,
Silica balloon, Shirasu balloon, Perlite,
These include permiculite, powdered synthetic resins, petroleum waxes, vegetable waxes, and natural and synthetic staple fibers. The particle size of these particles is preferably about 0.1 to 30 microns. The filler is used in an amount of 20 to 200 parts per 100 parts by weight of the prepolymer (in the present invention, parts indicate parts by weight). To produce a mixture of polyurethane prepolymer and filler, organic polyisocyanate and polyol may be reacted to form a prepolymer, and then filler may be mixed, or organic polyisocyanate, polyol, and filler may be mixed. After that, the organic polyisocyanate and the polyol may be reacted to form a prepolymer. In the present invention, the amount of water used (X parts) depends on the amount (parts) of water contained in the filler and thixotropic agent to be mixed with 100 parts of the polyurethane prepolymer having an NCO group content of M% by weight. , defined by equation (2). X=M/42×A×9−Y...(2) In formula (2), the value of A is preferably 0.05 to 0.40,
Among these, 0.1 to 0.25 is particularly suitable. If the value of A is lower than this range, sagging will occur after construction, and if it is higher than this range, construction will become difficult. Examples of the thixotropic agents used in the present invention include fine particulate silica, aluminum oxide, titanium oxide, vinyl chloride plastisol, surface-treated bentonite, and calcium carbonate. The thixotropic agent is used in an amount of 1 to 100 parts per 100 parts of the prepolymer, preferably 2 to 50 parts. In addition, in the present invention, a solubilizer,
Solvents, adhesion enhancers, catalysts, stabilizers, colorants, etc. can be used. Examples of plasticity include dibutyl phthalate,
Dioctyl phthalate, dioctyl adipate,
These include dibutyl sebacate, trischloroethyl phosphate, and chlorinated paraffin. Examples of the solvent include toluene, xylene, and aliphatic and aromatic hydrocarbons having a boiling point of 180 to 380°C. Examples of adhesion enhancers include silane coupling agents from Shin-Etsu Chemical Co., Ltd. and organic titanates from Nippon Soda Co., Ltd. As a catalyst, for example, an organometallic compound such as dibutyltin dilaurate, tin octoate, or lead octoate is used. Examples of stabilizers include positionally hindered phenols such as Irganox-1010 and -1076 manufactured by Ciba Geigy, benzotriazoles such as Tinuvin-P, -327, and -328, Sanol LS-770, -744, and Tinuvin-144. These positionally hindered amines may be used alone or in combination of two or more. To carry out the present invention, first, an organic polyisocyanate is reacted with a polyol and a polyhydric alcohol in a nitrogen stream by heating and stirring at 80 to 100°C for 2 hours to obtain a polyurethane prepolymer. Filler is added to polyurethane prepolymer and kneaded at room temperature to 50°C using a powerful mixing device such as a roll, planetary mixer, or dissolver to uniformly disperse the filler. At this time, after uniformly mixing the organic polyisocyanate, polyol, polyhydric alcohol, and filler using the above device,
A prepolymer can also be produced by heating for a period of time or by leaving it at room temperature for several days. Next, a required amount of water is added to this mixture, and the mixture is kneaded using the above-mentioned apparatus at room temperature to 50°C so as to be sufficiently uniformly dispersed.The temperature is then raised to 70 to 90°C to allow the water to react. After the water reaction is completed, a pre-dried thixotropic agent is added and kneaded using the above-mentioned device at room temperature to 60°C to uniformly disperse the mixture. If necessary, a plasticizer or solvent is added and mixed, and the viscosity is adjusted to an appropriate level to produce a product. The urethane composition according to the present invention is easy to apply;
Because it has excellent thixotropy, it does not cause any development such as sagging after installation. Furthermore, since there is no difference in thixotropy due to differences in filler type or lot, it is possible to always produce construction materials of constant quality. (Example) Next, an example of the present invention will be described. The water content in the filler and thixotropic agent used in the Examples was measured in accordance with JIS K6223. In addition, sag was measured using the slump test method described in JIS A5758. Example 1 Polymethylene polyphenyl polyisocyanate (manufactured by Mitsui Nisso Urethane Co., Ltd.,
MDI-CR) 584 g (4.29 equivalents) was charged. While stirring at 50°C in a nitrogen stream, add 400 g (0.4 equivalents) of a polyol with a molecular weight of 2000 obtained by addition polymerizing equimolar moles of propylene oxide and ethylene oxide to propylene glycol and 19 g (0.4 equivalents) of neopentyl glycol, A heating reaction was carried out at 80°C for 2 hours to obtain prepolymer A having an NCO group content of 14.5% by weight and a viscosity of 21,100 cps/25°C. Charge 530 g of prepolymer A and 290 g of calcium carbonate with a water content of 0.2% by weight (manufactured by Tsuchiya Kaolin Co., Ltd., Heavy Charcoal Cal) into the mixer of Contents 1, and mix at room temperature for 30 g.
Stir and mix for a minute. Next, add 1.7g of water and heat at 30°C.
After stirring and mixing for 15 minutes, the mixture was stirred at 80° C. for 60 minutes to react with water. After the reaction, the internal temperature was lowered to 50°C, and 40 g of fine particulate silica (Aerosil 200, manufactured by Nippon Aerosil Co., Ltd.) with a water content of 2.5% by weight was added and mixed for 30 minutes. To this mixture, 70 g of toluene was added and mixed for 15 minutes to form urethane. Composition C was obtained. The slump test result of urethane composition C was 0 mm.
No sag was observed at all. In this embodiment, the value of A in equation (2) is 0.2. Example 2 Carbodiimide-modified polymethylene polyphenyl polyisocyanate (manufactured by Mitsui Nisso Urethane Co., Ltd.,
MDI-LD) 606g (4.18 equivalents), molecular weight obtained by addition polymerizing propylene oxide and ethylene oxide to propylene glycol in a 1:3 molar ratio
2000 polyol (400 g (0.4 equivalent)) and dipropylene glycol (26 g (0.4 equivalent)) were reacted in the same manner as in Example 1, and the NCO group content was 13.5% by weight and the viscosity was
Prepolymer B was obtained at 35,800 cps/25°C. Next, 530 g of prepolymer B and 290 g of talc with a water content of 0.5% by weight (manufactured by Nippon Talc Co., Ltd., Simgon Talc) were stirred in a mixer, and treated in the same manner as in Example 1.
0.6g was reacted. Further, 40 g of particulate silica having a water content of 2.5% by weight was added and treated in the same manner as in Example 1, and then 70 g of toluene was added and mixed to obtain urethane composition D. The slump test result of urethane composition D was 0 mm, and no sagging was observed after construction. In this example, the value of A in equation (2) was 0.2. Example 3 Molecular weight obtained by addition polymerizing 308.6 g (2.27 equivalents) of polymethylene polyphenyl polyisocyanate and equimol of propylene oxide and ethylene oxide to propylene glycol in the mixer of Content 1.
2000 polyol 211.4 g (0.211 eq.), neopentyl glycol 10 g (0.211 eq.), water content 0.2
290 g of calcium carbonate (wt%) and 1.7 g of water were charged, and the mixture was stirred and mixed for 30 minutes at an internal temperature of 50° C. or less while cooling. Next, the temperature was raised and a heating reaction was carried out at 80°C for 60 minutes. After the reaction, the internal temperature was cooled to 50℃ and the water content was 2.5.
40 g of particulate silica (wt%) was added and mixed for 30 minutes, and further 70 g of toluene was added and mixed for 15 minutes to obtain urethane composition E. This urethane composition E
The slump test result was 0 mm, and no sagging was observed after construction. In this example, the value of A in equation (2) was 0.2. Example 4 Urethane composition F was obtained in exactly the same manner as in Example 1 except that 1.0 g of water was used in Example 1. The slump test result of this urethane composition F was 0 mm, and no sagging was observed after construction. In this example, the value of A was 0.12. Comparison rows 1 to 3 Table 1 shows the influence of water on slump and workability when the amount of water used in Example 1 was varied.

[Table] As is clear from Table 1, the A value in equation (2) is
If it is less than 0.05, sag will occur, and if it is more than 0.40, the composition will gel, resulting in poor workability. (Effects of the Invention) The urethane composition of the present invention has good workability and does not cause sag, so it can be easily used for adhesion of wooden materials and buildings and for filling voids in civil engineering construction work. I can do it.

Claims (1)

[Scope of Claims] 1. A mixture of 100 parts by weight of a polyurethane prepolymer having 2 to 30% by weight of NCO groups at the terminals produced by the reaction of a polyol and an organic polyisocyanate and 20 to 200 parts by weight of a filler is added with the following: Formula (1) X = M / 42 × (0.05 to 0.40) × 9-Y (1) [However, Y represents the amount (parts by weight) of water contained in the filler and thixotropic agent. ] A urethane composition with improved thixotropy, characterized in that after adding and reacting the amount of water shown in the following, 1 to 100 parts by weight of a thixotropy imparting agent are added and kneaded.