JPS648032B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to moisture-curing polyurethane resin primers containing dilutable solvents for flooring or paving materials and the like. Since this type of moisture-curing urethane cures by reacting with moisture such as atmospheric moisture, it has been widely used as a one-component polyurethane as a paint, adhesive, or filler. In the field of polyurethane flooring materials,
This type of moisture-curing urethane has long been used as a primer for underlying substrates, and today, this polyurethane-based flooring material has abrasion resistance,
As a chemical-resistant and elastic seamless flooring material, it is used as flooring material for schools, hospitals, condominiums, general offices, factories, etc., as well as paving materials for gymnasium floors and all-weather outdoor exercise facilities (also called fields and tracks). It has a wide range of uses. By the way, in the construction of such flooring materials or paving materials, unless the base material is destroyed by the solvent contained in moisture-curing urethane, as in the case of a base material such as asphalt concrete, these primers cannot be used. Moisture-curing one-component urethane is used, but the one currently in use is a moisture-curing urethane pre-containing solvent obtained from the reaction of tolylene diisocyanate and a polyol whose main component is polyether polyol. It is a polymer. Normally, the above tolylene diisocyanate-based moisture-curing urethane prepolymer solution is applied as a primer to the underlying concrete and mortar, and then a two-component room-temperature-curing urethane is applied on top to create the desired thickness. By forming elastic seamless flooring materials, polyurethane-based flooring materials are constructed. On the other hand, thick coatings mainly made of polyurethane resin are often used for floors intended for exercise such as gymnasiums, and for pavement bases such as fields and tracks used as outdoor exercise facilities. In some cases, urethane alone can be used to form an elastic product of any thickness, but from the standpoint of providing even more elasticity, reducing costs, or effectively utilizing waste materials, waste tire powder or chips can be used as a two-component or two-component product. It may also be used in combination with a one-component urethane resin. In these various types of construction, if the base is newly installed concrete or mortar and has not been sufficiently dried, especially in the winter or indoors where it is difficult to dry, first apply the above-mentioned method on top of the base. When applying a tolylene diisocyanate primer and then applying a two-component urethane resin for flooring,
Within 3 to 12 months after finishing, a blackish-brown stain-like pattern is often observed on the surface layer of urethane flooring, but such a stain-like pattern cannot be removed with simple operations such as daily cleaning. Although the essential functions of the flooring material are not degraded or inhibited by this, the aesthetic appearance is significantly impaired, which is undesirable because the service life thereof is shortened. In addition, in the case of construction in which waste tire powder or chips are mixed into urethane for the purpose of imparting further elasticity, reducing costs, or recycling waste as described above, the urethane contained in the tire is
Polyurethane coatings are probably contaminated by components such as amine-based rubber anti-aging agents and extender oils, resulting in a surface condition similar to the one above, which significantly impairs aesthetics. , it can no longer be used for applications that require aesthetic appearance, and its frequent applications are restricted. However, as a result of intensive research into the prevention of contamination of the urethane surface layer due to the mixing of rubber powder or rubber chips from tires, etc., and the insufficiently dry base of concrete or mortar, the present inventors found that a specific polymethylene Using a moisture-curing polyurethane resin primer made of a urethane prepolymer with isocyanate groups at the end obtained using polyphenyl isocyanate and its dilutable solvent can be used to seal various contaminants and is an excellent solution to stain-like patterns. The present invention was completed based on the discovery that a blocking effect can be imparted. Furthermore, as will be described later, the present inventors have devised a laboratory-scale blemish-like pattern generation reproduction apparatus that can quickly confirm the effectiveness of this resin in obtaining the resin primer of the present invention. According to the method, it is possible to reproduce the appearance of a stain-like pattern similar to that seen at an actual construction site in a short period of time. In the present invention, a polyether polyol having a molecular weight of 200 to 3000 is used as an essential polyol component, and as an isocyanate component, a polyether polyol having a structural formula of (However, n in the formula is 0 and an integer from 1 to 4.) Using polymethylene polyphenyl isocyanate, the content of free isocyanate groups obtained by reacting these two components is The present invention provides a moisture-curing polyurethane resin primer consisting of an isocyanate prepolymer of 13 to 25 percent by weight solids and its dilutable solvent, particularly for use in flooring or paving materials and the like (hereinafter referred to as , "flooring materials, etc."
It is abbreviated as ), it provides a resin that has an excellent sealing effect against various contaminants from the underlying substrate of these flooring materials. Here, the polyol has a molecular weight of
A polyether polyol in the range of 200 to 3000 is essential, and in addition to this, a so-called low molecular weight polyol with a molecular weight of 200 or less is used,
Preferably, trifunctional low molecular weight polyols are used. First, typical starting materials (initiators) for producing the former polyether polyol are ethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, hexylene glycol, glycerin, trimethylolpropane, and trimethylol. Ethane, 1,
2,6-hexanetriol, pentaerythritol, α-methyl glycoxide, sorbitol,
Suucrose: An active hydrogen-containing compound such as ethylenediamine or diethylenetriamine, and in the presence of such an active hydrogen-containing compound, an alkylene oxide or its equivalent substance represented by typical examples such as ethylene oxide, propylene oxide, butylene oxide, or styrene oxide It is a polyether polyol containing a hydroxyl group at the end, which is obtained by reacting one or more of these. Representative low molecular weight polyols of the latter include ethylene glycol, diethylene glycol,
These include propylene glycol, dipropylene glycol, butylene glycol, hexylene glycol, glycerin, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, or pentaerythritol. On the other hand, the organic isocyanate component to be reacted with the polyol component has the structural formula: (However, n is as described above.) A polymethylene polyphenyl isocyanate represented by is used, and both of these components are formed into a urethane preform through a known and commonly used urethanization reaction in a ratio such that the molecular terminal becomes an isocyanate. Give the polymer. This urethane prepolymer is then diluted with a dilutable solvent to provide a resin solution with a resin content of 20-70% by weight, preferably 30-60% by weight. Typical diluent solvents used are those that do not react with isocyanates, such as toluene, xylene, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, or cellosolve acetate, which can be used alone or in combination to form urethanes. It is used together with the polyol component and organic isocyanate component from the early stage of the reaction. That is, this urethanization reaction is carried out in a conventional manner for 2 to 5 hours in a reaction vessel at 30 to 80°C in the presence of a conventional urethanization catalyst by adding the above-mentioned polyol component, organic isocyanate component, and solvent. Accordingly, the urethanization is carried out with stirring, and typical examples of the urethanization catalyst include metal catalysts such as dibutyltin laurate, tin octylate, and lead octylate. The content of free isocyanate groups in the urethane prepolymer obtained by such an operation is preferably 13 to 25 percent, particularly 13 to 22 percent, based on the weight of the resin solid content, and the viscosity of the resulting resin solution is about 20 to 500 cps. Easy to paint range is good. The resin of the present invention corresponds to a conventional tolylene diisocyanate-based moisture-curing urethane in which the tolylene diisocyanate is replaced with polymethylene polyphenyl isocyanate. The effect is not inferior to that of toluene diisocyanate, and first of all, the resin of the present invention has low toxicity because it uses polymethylene polyphenyl isocyanate, which has a lower vapor pressure than tolylene diisocyanate. It is toxic and has excellent properties of blocking stain patterns when used as a primer, and is therefore particularly useful as a primer for polyurethane flooring or paving materials and the like. It is applied to substrates such as concrete or mortar as a primer for materials, and is used as a sealant to prevent contamination of vulcanized rubber products. It is also used as a primer and adhesive for civil engineering, architecture, and woodworking. Next, the present invention will be explained in more detail with reference to Examples, and unless otherwise specified, all percentages are based on weight. Example 1 "Hiprox DP-" with a molecular weight of 2000 and an OH value of 56
2000'' (bifunctional polyether polyol manufactured by Dainippon Ink and Chemicals Co., Ltd.) 1000 g, 1,3-butylene glycol 60 g, trimethylolpropane 30 g, polymethylene polyphenyl isocyanate (using crude MDI manufactured by Nippon Polyurethane Co., Ltd.) Add 2713g and toluene so that the resin content is 60%, stir and mix at 50℃ for 3 hours, and the NCO% becomes 9.6 and the viscosity (at 25℃; the same applies below) becomes 260cps.
Urethane prepolymer and diluent solvent (toluene)
A moisture-curable polyurethane resin primer was obtained. Example 2 Xylene as a diluent solvent was added to the resin obtained in Example 1 to make the resin content 50%, and the viscosity was 74 cps.
A moisture-curable polyurethane resin primer was obtained. Example 3 Xylene as a diluent solvent was added to the polyurethane resin obtained in Example 1 to make the resin content 40% to obtain a moisture-curable polyurethane resin primer with a viscosity of 27 cps. Example 4 “Hipox RT-” with a molecular weight of 400 and an OH value of 422
400'' (trifunctional polyether polyol manufactured by Dainippon Ink and Chemicals Co., Ltd.), 403 g of the polymethylene polyphenyl isocyanate used in Example 1, and a mixture of equal weights of ethyl acetate and toluene were mixed with resin content. 50% at 50℃
After stirring and mixing for hours, the NCO% was 8.3 and the viscosity was
A moisture-curable polyurethane resin primer of 360 cps consisting of a urethane prepolymer and a dilutable solvent (toluene) was obtained. Comparative example 1 “Hiprox DP” with a molecular weight of 1000 and an OH value of 112
-1000” (bifunctional polyether polyol manufactured by Dainippon Ink & Chemicals Co., Ltd.) 1000g, trimethylolpropane 90g, 1,3-butylene glycol 201g
Toluene was added to 1400 g of 2,4-/2,6-(80/20) tolylene diisocyanate so that the resin content was 60%, and the mixture was stirred and mixed at 60°C for 5 hours, and the NCO% was 6.5 and the viscosity was A polyurethane resin primer consisting of a urethane prepolymer and a diluent solvent (toluene) with a yield of 1300 cps was obtained. Comparative Example 2 Xylene was added as a diluent solvent to the polyurethane resin obtained in Comparative Example 1, and the resin content was 40%.
A polyurethane resin primer with a viscosity of 17 cps was obtained. Examples 1 to 4 and Comparative Example 1 obtained above,
For each of the resins in 2, we investigated whether or not they caused a stain-like pattern when used as a primer.
Using a specially devised device to reproduce the generation of this stain-like pattern, we conducted a forced generation test, and also conducted an generation test at an actual construction site for polyurethane-coated flooring. First, (1) the test method for forced generation of a stain-like pattern from a mortar base is to place mortar with sand: portland cement = 3:1 (weight ratio) in a tin box measuring 20 x 20 cm and 5 cm high. The surface was poured to a height of 3 cm and the surface was smoothed with a metal trowel, and the surface was left in a room under standard conditions for 7 days, and the surface was placed in a dryer at 60℃ for 7 days to dry thoroughly. Two types of mortar were prepared, the former being a wet mortar and the latter being a dry mortar. Next, a fixed amount of each resin primer was applied separately onto both of these mortar disks, and the number of times of application was varied depending on the sample. The primer was then allowed to dry for about 4-5 hours under standard conditions indoors. Next, after drying each urethane primer, apply a two-component polyurethane coating flooring material "Priadaik PF-359/E-135" (Dainippon Ink & Chemicals Co., Ltd.)
Co., Ltd. product) to a thickness of 1.5 mm and left to cure in a room under standard conditions for 7 days. Then, leave the tin box in steam at 100-105℃ for 8 hours and remove it from the steam atmosphere.
The entire tin box was then covered with a 25-micron polyester film and exposed to a 1000 watt ultraviolet lamp for three hours to force a blotchy pattern. Next, as another example, (2) a test method for forced generation of a stain-like pattern from a urethane substrate containing rubber chips with a diameter of 2 to 3 mm, a size of 20 x 20 cm and a height of 5 cm is used.
Rubber chips/polyurethane coated flooring material ("Praiadik PF-359/E") was placed inside a tin box.
-135'') = 2/1 (weight ratio) was added, the thickness was made smooth to 10 mm, and a urethane base was installed. Next, this substrate was left in the standard state for 7 days, and then each resin primer was applied separately to the surface of the substrate, and the number of applications was varied depending on the sample. After that, it is dried for 4 hours under standard conditions indoors, and then a two-component flooring material called "Prior Adix" is applied on top of this dry primer layer.
PF-359/E-135" was applied separately to a thickness of 2 mm and left in standard conditions for 7 days. Thereafter, in the same manner as in the case of the stain-like pattern generation test from the mortar base (1) above, first water vapor,
Next, treatments were performed in the order of ultraviolet irradiation to forcibly generate a blotchy pattern. (3) Results of forced stain pattern generation tests Tables 1 and 2 summarize the results of the stain pattern generation tests for mortar bases and urethane bases containing rubber chips.

【table】

[Table] On the other hand, whether or not a stain-like pattern occurs when each resin obtained in Example 2 and Comparative Example 2 is used as a primer for the flooring material at an actual polyurethane-coated flooring construction site. The results of the test were as follows. In other words, the resin of Comparative Example 2 was used as a primer at a rate of 0.3 kg/m ² on a mortar base placed in the winter and where polyurethane coating was applied within two weeks after the mortar base was placed. A stain-like pattern appeared after 6 months had passed, but in contrast, no stain-like pattern was observed even after 1 year had passed in the area where the resin primer of Example 2 was applied at the same amount. It has been confirmed that the resin primer of the present invention has the effect of sealing various contaminants that cause such stain-like patterns and blocking the patterns, and it has also been confirmed that this effect is significant. It was done. Example 5 Using a four-necked flask, 101.4 g of polymethylene polyphenyl isocyanate was added to 12.5 g of "Hiprox RQ-500" (manufactured by Dainippon Ink & Chemicals Co., Ltd.) with a molecular weight of 500 and an OH value of 449, and nitrogen was added. Gas flow down 80
By reacting for 2 hours at ℃, xylene was added to the urethane prepolymer with a free isocyanate group content of 24.0%.
113.9 g was added to obtain a moisture-curable polyurethane resin primer liquid with a viscosity of 100 cps (at 25° C.) and a free isocyanate group content of 12.00%. This was subjected to a forced generation test using the stain-like pattern generation reproduction device described above. The results are shown in Table 3. Comparative Examples 3 to 6 Molecular weight 2000, OH value 56 using a 4-necked flask
352.5g of polymethylene polyphenyl isocyanate to 1000g of "Hiprox DP-2000",
464.7g, 634.3g, 848.2g were added and reacted to give free isocyanate group contents of 5%, 7%, 9.5%,
Add xylene to 12% urethane prepolymer, solids content 50%, viscosity 50cps, 40cps, 35cps,
A 25 cps moisture-curing polyurethane resin primer was obtained. This was subjected to a forced generation test using the stain-like pattern generation reproduction device described above. The results are shown in Table 3. Comparative Example 7 Using a four-necked flask, instead of 101.4 g of polymethylene polyphenyl isocyanate in Example 5,
248.3g of the same isocyanate was added and reacted in the same manner as in Example 5, resulting in a free isocyanate group content of 28%.
260.8 g of xylene was added to the urethane prepolymer to obtain a moisture-curable polyurethane resin primer having a solid content of 50%, a viscosity of 50 cps (at 25°C), and a free isocyanate group content of 14.0%. Furthermore, a forced generation test was conducted using a spot-like pattern generation reproduction device. The results are shown in Table 3.

【table】

Claims (1)

[Claims] 1 A polyether polyol with a molecular weight of 200 to 3000 is an essential polyol component, and this and the following structural formula (However, n in the formula is 0 and an integer from 1 to 4.) The free isocyanate group content obtained by the reaction with polymethylene polyphenyl isocyanate represented by the formula is 13 to 13 per solid weight of resin.
Moisture-curing polyurethane resins for non-dry substrates such as concrete or mortar, flooring or paving materials mixed with rubber powder or chips such as tires, and the like, consisting of 25% isocyanate prepolymers and their dilutable solvents. Primer.