JP2009096876A - Method for producing polyurethane emulsion, polyurethane emulsion and polyurethane coated glass - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyurethane emulsion having film strength, adhesion to a body to be coated, flexibility and elasticity in a cured state. <P>SOLUTION: A method for producing the polyurethane emulsion includes (I) a step of bringing an isocyanate component (A) comprising one or more organic polyisocyanates, a polyol component (B) comprising a bifunctional polyol (B1) or a mixture of the bifunctional polyol (B1) and a bi- to tetrafunctional polyol (B2), and a polyol component (C) having a carboxy group into a reaction under the condition of an isocyanate to active hydrogen group ratio (by equivalent) of 1.0/(0.5-0.9) to produce a prepolymer (D), and (II) a step of dispersing and stirring the prepolymer (D), after neutralization, in water under the condition of ≥130 pts.mass of water based on 100 pts.mass of the prepolymer (D) to prepare an emulsion, which is then refluxed at 40-45°C for 12 h to bring the residual polyisocyanates and water into a chain extension reaction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a polyurethane emulsion for providing a polyurethane having a high elongation, a polyurethane emulsion, and a glass coated with the polyurethane emulsion. More specifically, the present invention relates to a polyurethane emulsion excellent in adhesion and elasticity and capable of preventing scattering of glass fragments even when the glass is broken when a polyurethane coating layer is formed on the glass surface, and a method for producing the same. The present invention also relates to a polyurethane-coated glass in which the polyurethane emulsion is coated on the glass surface.

  Conventionally, a water-based polyurethane emulsion obtained by curing a paint, an adhesive, a coating agent or the like has been known. This water-based polyurethane emulsion has improved adhesion, coating strength, hardness and the like when applied to an object to be coated.

For example, in Patent Document 1, while maintaining alkali resistance, hydrolysis resistance, heat resistance, etc., it is particularly excellent in low temperature flexibility and low temperature flexibility, and is suitable for adhesives, coating materials, paints, synthetic leather, and artificial leather. For the purpose of providing a polyurethane emulsion to be used, a urethane prepolymer composed of an organic diisocyanate, a polycarbonate diol, polytetramethylene glycol and a compound having one hydrophilic center and at least two isocyanate-reactive groups, and a chain extender; A polyurethane emulsion comprising the reaction product of is described.
JP 2002-179759 A

However, since the polyurethane cured product obtained by curing the polyurethane emulsion described in Patent Document 1 still lacks flexibility, for example, when the glass on which the polyurethane layer is formed is broken, the coated polyurethane cured product is also broken. Scattering of glass fragments could not be prevented.
The present invention was developed for the purpose of solving these drawbacks of conventional polyurethane emulsions. The purpose of the present invention is to provide film strength, adhesion to an object, flexibility and elasticity in a cured state. And providing a polyurethane emulsion capable of preventing scattering of glass fragments even when the glass is broken.
Another object of the present invention is to provide a polyurethane-coated glass in which this polyurethane emulsion is coated on the surface of glass or the like.

The process for producing a polyurethane emulsion according to claim 1 of the present invention comprises:
(I) an isocyanate component (A) comprising one or more organic polyisocyanates;
A polyol component (B) comprising a bifunctional polyol (B1) or a mixture of the bifunctional polyol (B1) and the 2-4 functional polyol (B2);
A polyol component (C) having a carboxyl group;
The
A step of producing a prepolymer (D) by reacting under conditions of isocyanate group / active hydrogen group (equivalent ratio) = 1.0 / 0.5 to 0.9;
(II) after neutralizing the obtained prepolymer (D), dispersing in water under conditions of 130 parts by weight or more of water with respect to 100 parts by weight of the prepolymer (D) and stirring to make an emulsion;
By refluxing this at 40 to 45 ° C., a diamine that is slowly generated by a slow reaction between the remaining polyisocyanate component and water is reacted with the remaining polyisocyanate component to complete the reaction.
The method for producing a polyurethane emulsion according to claim 2 is characterized in that, in claim 1, an aqueous pigment and an aqueous thickener are further added to the emulsion.

The polyurethane emulsion of claim 3 comprises an isocyanate component (A) comprising one or more organic polyisocyanates;
A polyol component (B) comprising a bifunctional polyol (B1) or a mixture of the bifunctional polyol (B1) and the 2-4 functional polyol (B2);
A polyol component (C) having a carboxyl group;
The
Is reacted under the conditions of isocyanate group / active hydrogen group (equivalent ratio) = 1.0 / 0.5 to 0.9 to obtain a prepolymer (D). After neutralizing this, the prepolymer (D) 100 A diamine that is slowly generated by a slow reaction of the remaining polyisocyanate component and water by refluxing at 40 to 45 ° C. by adding 130 parts by weight or more of water with respect to part by weight of the remaining polyisocyanate component The reaction is completed by the reaction.
The polyurethane emulsion of claim 4 is characterized in that, in claim 3, an aqueous pigment and an aqueous thickener are further added to the emulsion.

  The polyurethane-coated glass according to claim 5 is characterized in that the polyurethane emulsion according to claim 4 or 5 is applied to the glass surface.

According to the present invention, after curing, a polyurethane emulsion having high adhesion to an object to be coated, flexibility and elasticity having a tensile elongation at break of 500% or more, toughness having a tensile strength at break of 20 MPa or more, and water resistance is obtained. be able to.
In addition, when a urethane layer is formed on the glass surface using this polyurethane emulsion, the urethane layer does not break even if the glass is cracked. Glass fragments can also be held to prevent glass scattering, and safety can be ensured in the event of an earthquake.

Hereinafter, the configuration of the present invention will be described in detail with reference to the drawings and tables.
The process for producing the polyurethane emulsion of the present invention comprises:
(I) an isocyanate component (A) comprising one or more organic polyisocyanates;
A polyol component (B) comprising a bifunctional polyol (B1) or a mixture of a bifunctional polyol (B1) and a 2-4 functional polyol (B2);
A polyol component (C) having a carboxyl group;
Are reacted under the conditions of isocyanate group / active hydrogen group (equivalent ratio) = 1.0 / 0.5 to 0.9 to produce a prepolymer (D),
(II) after neutralizing the obtained prepolymer (D) and dispersing in water under conditions of 130 parts by weight or more of water with respect to 100 parts by weight of the prepolymer (D) to form an emulsion. It is characterized by becoming.

  The obtained polyurethane emulsion is an aqueous emulsion of an anionic polyurethane resin, and its cured product has a film strength of elongation of 500% or more and breaking tensile strength of 20 MPa or more, such as glass plate, acrylic plate, PET, etc. Excellent adhesion to polyester plates. The glass plate on which the emulsion is applied and cured to form a polyurethane layer exhibits an excellent effect that even when the glass is crushed, the fragments are not scattered.

  Examples of the isocyanate component (A) comprising the organic polyisocyanate used in the present invention include 4,4′-methylenebiscyclohexyl diisocyanate (hydrogenated MDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), and dimethylcyclohexane. Aliphatic diisocyanates such as diisocyanate (hydrogenated XDI), and the like. These may be used alone or in combination of two or more. Among them, when a prepolymer (D) neutralized product described later is introduced into water, it is preferable to avoid a rapid reaction with water until the emulsion is stabilized. Forone diisocyanate (IPDI) is more preferred.

  The polyol component (B) used in the present invention is a bifunctional polyol (B1) or a mixture (B1 + B2) of the bifunctional polyol (B1) and the 2-4 functional polyol (B2).

Although it does not specifically limit as bifunctional group polyol (B1) used for this invention, For example,
B) Polyoxypolyalkylene diol (obtained by addition polymerization of alkylene oxide to short molecular diol)
B) Polyester diol (obtained by condensation polymerization of dicarboxylic acid and diol)
C) Polyoxytetramethylene polyol (obtained by ring-opening polymerization of short molecular diol and furan)
D) Carbonate polyol (obtained by condensation polymerization of short molecular diol and dialkyl carbonate)
E) Lactone polyols (obtained by ring-opening addition polymerization of lactones to short molecular diols)
F) Castor oil-based polyol (castor oil or castor oil derivative)
G) Liquid rubber polyol (obtained by terminal hydroxylation of butadiene rubber with hydrogen peroxide)
H) and mixtures of two or more thereof. Among them, the above a) and c) are preferred from the viewpoint of compatibility with other components, suppression of increase in viscosity of the synthetic system, easy emulsification, hydrolysis resistance and the like.
The molecular weight of the bifunctional polyol (B1) needs to be 1000 to 4000, but when the molecular weight is less than 1000, the resulting polyurethane cured product has an elongation of 500 or less, which is inappropriate. When the molecular weight exceeds 4000, the compatibility with other components, particularly the compatibility with the isocyanate component (A), is deteriorated, and the production is hindered.
In order to obtain a better effect, the molecular weight is preferably 1500 to 2000 for the same reason as described above.

Although it does not specifically limit as 2-4 functional group polyol (B2) used for this invention, For example,
B) Polyoxypolyalkylene polyol (obtained by addition polymerization of alkylene oxide to short molecular polyol)
Nu) Lactone polyol (obtained by ring-opening addition polymerization of lactone to short molecule polyol)
And a mixture of two or more of these. Among these, the lactone polyols mentioned in the above (iii) are preferable from the viewpoints of compatibility with other components and easy emulsification.
Here, examples of the short molecular polyol include glycerin, trimethanolpropane, hexanetriol, pentaerythritol, and diglycerin. Of these, glycerin and trimethanolpropane are particularly preferable.
The molecular weight of the 2-4 functional group polyol (B2) is preferably 300-1000. This is because when the molecular weight is less than 300, the viscosity of the prepolymer becomes high, making it difficult to emulsify, and when the molecular weight exceeds 1000, the crosslinking effect is reduced and the film strength is lacking.
In order to obtain a better effect, the molecular weight is preferably 500 to 800 for the same reason as described above.

  In the present invention, the compounding amount of the polyol component (B) is 0.3 to 0.000 for a compound having one hydrophilic center and at least two active hydrogen groups with respect to 1 equivalent of the isocyanate component (A). It should be 5 equivalents, preferably 0.3 to 0.4 equivalents. When the said compounding quantity is less than 0.3 equivalent, the elongation rate of the polyurethane hardened | cured material obtained is 500% or less, and is unsuitable. Moreover, when exceeding 0.5 equivalent, the viscosity of a prepolymer (D) will be high and emulsification will become difficult.

  Examples of the polyol (C) having a carboxyl group used in the present invention include 2,2-dimethylolpropionic acid and 2,2-dimethylolbutanoic acid. Diaminocarboxylic acids such as lysine, cystine and 3,5-diaminocarboxylic acid can also be used. Among these, 2,2-dimethylolpropionic acid and 2,2-dimethylolbutanoic acid are preferred because they are diols, and thus the reaction with isocyanate is slow, easy to handle, and inexpensive.

In addition, the compounding quantity of bifunctional polyol (B1) and 2-4 functional group polyol (B2), and the compounding quantity of these and polyol (C) are the equivalent per isocyanate,
Bifunctional polyol (B1): 0.15 to 0.4 equivalents,
2 to 4 functional group polyol (B2): 0.06 to 0.10 equivalent,
And the total amount of B1 + B2 equivalents is 0.3 to 0.5 equivalents,
Polyol (C): 0.1 to 0.4 equivalent (details will be described later)
And the total amount of B1 + B2 + C equivalent is 0.5-0.9 equivalent (details will be described later),
It is preferable that

In the present invention, when preparing the prepolymer (D), it is necessary to further add a neutralizing agent in order to form a salt with the polyol (C) having a carboxyl group. As neutralizers, tertiary amines such as trimethylamine, triethylamine, triisopropylamine, tributylamine, triethanolamine, N-methyldiethanolamine, N-methylmorpholine, and alkalis such as sodium hydroxide, potassium hydroxide, and ammonia In order to improve the weather resistance and water resistance after drying, those having high volatility are preferable, and trimethylamine and triethylamine are particularly preferable. These can be used alone or in combination of two or more.
The amount of the neutralizing agent used is 1 to 0.3 mol of the neutralizing agent with respect to 1 mol of the polyol (C) having a carboxyl group. When the amount is less than 0.3 mol of the neutralizing agent, emulsification becomes difficult.

  A carboxylate is formed as described above and introduced into the prepolymer (D). The amount of carboxylate introduced is 0.1 to 0.4 equivalent, preferably 0.2, of a compound having one hydrophilic center and at least two active hydrogen groups per equivalent of the isocyanate component (A). It is preferable that it is -0.3 equivalent. When the amount of carboxylate introduced is less than 0.1 equivalent, emulsification is difficult, while when the amount of carboxylate introduced exceeds 0.4 equivalent, the polyurethane film after curing is resistant to hot water and alcohol. This is not preferable because the properties are lowered.

In the method for producing the polyurethane emulsion of the present invention, the step of producing the prepolymer (D) includes, for example,
(i) with respect to 1 equivalent of the isocyanate component (A),
(ii) A polyol component (B) composed of a bifunctional polyol (B1) having a molecular weight of 1000 to 4000 or a mixture of a bifunctional polyol (B1) and a 2 to 4 functional polyol (B2) is 0.3 to 0.5 equivalents,
(iii) 0.1 to 0.4 equivalent of a polyol component (C) having a carboxyl group,
It is made to react by a known method (for example, reaction at 80 to 95 ° C. for 4 hours) to obtain a prepolymer (D) having a terminal isocyanate group.
Here, the ratio of isocyanate group to active hydrogen group is isocyanate group / active hydrogen group (equivalent ratio) = 1 / 0.5 to 0.9, preferably 1 / 0.6 to 0.7. Is preferred. When this ratio is less than 1 / 0.5, the molecular weight of the polyurethane emulsion becomes small, and the required tensile strength at break (20 MPa or more) cannot be achieved in the cured polyurethane film. On the other hand, when the ratio exceeds 1 / 0.9, the viscosity of the prepolymer (D) becomes high, which makes it difficult to make an aqueous emulsion later.

In the method for producing a polyurethane emulsion of the present invention, the prepolymer (D) obtained as described above is neutralized, then dispersed in water and stirred to obtain an emulsion.
The amount of water for emulsification needs to be 130 parts by mass or more of water with respect to 100 parts by mass of the prepolymer (D). Preferably it is 150-300 mass parts of water. When the amount of water is less than 130 parts by mass, the solution gels, which is not preferable because an emulsion cannot be formed.
In addition, when emulsifying, a method of forcibly dispersing the prepolymer (D) directly in water as described above to obtain a polyurethane emulsion may be used. Alternatively, the prepolymer (D) is compatible with water. Alternatively, after dissolving in an organic solvent, water may be added in the above amount, and then the organic solvent may be removed.

  In addition, a well-known additive and auxiliary agent can be used for the polyurethane emulsion obtained by making it above as needed. For example, pigments, plasticizers, flame retardants, organic and inorganic fillers, reinforcing agents, anti-gelling agents, thickeners, viscosity modifiers, antistatic agents, surfactants (leveling agents, antifoaming agents, dispersion stabilizers) , Anti-blocking agents), antioxidants, light stabilizers, ultraviolet absorbers, and the like. In addition, since it is an essential component in the case of manufacturing a pigment in the coating method of the polyurethane emulsion of this invention mentioned later about a pigment and a thickener, it mentions later for details. The above additives and auxiliaries can be used in advance mixed with the polyol of the raw material component.

Next, the urethanization procedure for curing the polyurethane emulsion of the present invention obtained as described above to form a polyurethane film will be described below.
Since the polyurethane emulsion obtained as described above leaves 0.1 to 0.5 equivalents of unreacted residual isocyanate groups, the polyurethane emulsion is then refluxed at 40 to 45 ° C. for 12 hours or more. A polyamine that is slowly generated by a slow reaction with water is reacted with the remaining polyisocyanate component to complete the reaction.
Here, when the reflux temperature is 40 ° C. or less, the reaction between the remaining polyisocyanate and water is extremely slow, and the production of polyamine does not proceed. As a result, the remaining polyisocyanate remains and does not lead to sufficient polymerization and is dried. The later film becomes fragile and has a tensile strength of 20 Mpa or less and an elongation of 500% or less, which is not preferable. In addition, when the temperature is 45 ° C. or higher, the reaction between the residual polyisocyanate and water proceeds rapidly, so that the by-product carbon dioxide gas becomes a foaming agent to make the emulsion foamed and resinized, resulting in a clean emulsion. As a result, there is less residual polyisocyanate to be reacted with the generated polyamine, resulting in insufficient polymerization, the film after drying becomes brittle, the tensile strength is 20 Mpa or less, and the elongation is 500% or less. It is not preferable.

  At this time, a solvent such as an organic solvent can be used as necessary (although it has never been better not to use it). Solvents that can be used include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, ester solvents such as ethyl acetate, butyl acetate and isobutyl acetate, aromatic solvents such as toluene and xylene, and chloric solvents such as methylene chloride. Solvents and other organic solvents inert to isocyanates such as dioxane, dimethylfluramide, N-methylpyrrolidone, and tetrahydrofuran can be used. Among these, ketone solvents are preferable from the viewpoint that they are water-soluble and can be easily removed in a vacuum.

When a solvent is used, the solvent is removed under vacuum.
The polyurethane emulsion mixture thus obtained has a resin concentration of 40% or less and a liquid viscosity of 800 cps / 23 ° C. or less. If a polyurethane emulsion mixture with a higher resin content is required, it can be dehydrated under vacuum to increase the resin concentration and liquid viscosity.

  In urethanization, a known urethanization catalyst can be used as necessary. Specific examples include organic metal compounds such as dibutyltin dilaurate and lead octylate, and organic diamines such as triethylenediamine and N, N′-tetramethylbutanediamine.

  In the case of urethanization, as long as there is no hindrance to the polyurethane emulsion mixture, other resin-based emulsions can be blended and used. For example, acrylic emulsion, polyester emulsion, polyolefin emulsion, latex and the like. At this time, a dye may be added as necessary. The other resin-based emulsion and the dye are mixed using a ball mill, a sand grind mill or the like.

Next, a method for coating on a plate using the polyurethane emulsion obtained as described above or a mixture thereof, and particularly a coating method for coating on a glass surface will be described.
The obtained polyurethane emulsion or a mixture thereof is excellent in adhesion to the surface of glass plate, acrylic plate, PET plate, etc., and can be applied by mechanical coating, dipping, etc., or applied by brush, roller, spray, etc. be able to.

  Further, when the obtained polyurethane emulsion (resin concentration 40%) is coated on a PET film with a thickness of about 150 μm, dried at room temperature for 12 hours, and further dried at 100 ° C. for 30 minutes, a light layer with a thickness of about 60 μm is obtained. A yellow transparent film is obtained. This film has a tensile elongation at break of 500% or more, a toughness with a tensile strength at break of 20 MPa or more, and excellent water resistance.

  Furthermore, when room temperature drying is necessary, a polyurethane crosslinking agent (resin concentration: 40%) obtained by adding 1 to 3% of a reactive crosslinking agent to 100 parts by mass of the polyurethane emulsion is obtained in the same manner as described above. When coated and dried at room temperature for 1 hour, a colorless transparent film having a thickness of about 60 μm is obtained. This film has a tensile elongation at break of 500% or more, a toughness with a tensile strength at break of 20 MPa or more, and excellent water resistance.

  Here, the reactive crosslinking agent is an organic compound having two or more functional groups that react with a carboxylic acid group introduced into a polyurethane resin chain constituting a polyurethane emulsion, that is, a crosslinking reaction with the polyurethane resin in the emulsion. Refers to organic compounds. For example, a water-soluble epoxy resin such as Epolite (manufactured by Kyoeisha Chemical Co., Ltd.), a hydrophilic polycarbodiimide such as carbodilite (manufactured by Nisshinbo Co., Ltd.), an oxazolidone-based reactive polymer such as Epocross (manufactured by Nippon Shokubai Co., Ltd.) And the like.

  When these are used at room temperature drying, as described above, the addition amount is preferably 0.3 to 3% with respect to the polyurethane emulsion mixture. This is because when the amount added is less than 0.3%, the tensile elongation at break is 500% or more and the tensile strength at break is 20 MPa or more, but the water resistance is poor, and when it exceeds 3%, the tensile elongation at break is 500%. This is because

  When a polyurethane emulsion or a mixture thereof is coated on a glass product by dipping, it can be performed by a known method. The obtained urethane-coated glass product has high safety because glass fragments are not scattered even if the glass is broken. For example, a glass bottle with a film formed by dipping a polyurethane emulsion mixture (resin concentration 40%) once on the outside of a glass bottle to form a urethane layer and dried by the above method is broken into large pieces when hit with an iron hammer. The broken glass will not scatter. For comparison, when a glass bottle that does not form a urethane layer is struck with an iron hammer, it is crushed into small pieces and scattered into pieces.

In addition, the above polyurethane emulsion or a mixture thereof is made of a stained glass-like polyurethane-coated glass plate by adding a water-based pigment and a water-based thickener to produce a liquid or putty-like paint and applying it to a substrate such as glass. Can be manufactured. That is, an aqueous pigment and an aqueous thickener are added to the above-mentioned polyurethane emulsion (resin concentration 25-43%) to prepare a liquid paint. As the water-based pigment, a known water-based emulsion of a pigment can be used, and examples thereof include PSM toner (manufactured by Mikuni Dye Co., Ltd.).
In addition, water-based thickeners are materials that dissolve or disperse water to increase the viscosity. For example, Tikuzol (manufactured by Kyoeisha Chemical Co., Ltd.), Aromalon (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), Snowtex (electric Chemical Industry Co., Ltd.).
The blending amount is 5 to 15 parts by weight (other than white) or 40 to 60 parts by weight (white) of water-based pigment, 0 to water-based thickener with respect to 100 parts by weight of polyurethane emulsion (resin concentration 40%). 3 to 0.8 parts by mass (liquid paint) or 3 to 5 parts by mass (putty paint) is preferable.
The resting viscosities of the putty-like paint and the liquid paint are about 9000 cps and 3000 cps (BH viscometer), respectively.

The liquid or putty-like paint thus obtained is applied to the surface of glass or the like. That is, as shown in FIG. 1, first, a dark color such as black or dark gray is arranged in a frame shape on a substrate such as a glass plate or an acrylic plate to form an outer shell 1, and then an inner portion 2 of the frame is formed. And coloring using the liquid paint. By such a coating method, a stained glass-like polyurethane-coated glass plate can be obtained. In addition, it is also possible to change the color density by applying the polyurethane emulsion a plurality of times.
The stained glass-like polyurethane-coated glass plate obtained in this way can be produced at a lower cost than ordinary stained glass. Further, even when the glass is crushed, the polyurethane layer holds the glass fragments, so that the glass fragments can be prevented from being scattered and the safety is high.

EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example, this invention is not limited to a following example. Unless otherwise specified, “parts” and “%” in the examples mean “parts by mass” and “% by mass”, respectively. In the following, polyol (1) represents polyoxypolypropylene polyol (molecular weight 2000, functional group number 2), polyol (2) represents polyoxytetramethylene polyol (molecular weight 400, functional group number 2), polyol (3) Indicates a polyol (molecular weight 305, functional group number 3) obtained from ε-caprolactone ring-opening polymerization of trimethylolpropane.
The tensile test characteristic test described later is performed based on “JIS K6301 No. 3 dumbbell”, and the tensile tester is “Autograph S-500, manufactured by Shimadzu Corporation” and measured at a tensile speed of 100 mm / min. did.

Example 1
A four-necked flask equipped with a stirrer, a thermometer, a nitrogen seal tube, and a condenser was charged with 150 parts of methyl ethyl ketone, 170 parts of polyol (1), and 13.2 parts of polyol (3). Next, 100 parts of isophorone diisocyanate and 0.1 part of dibutyltin dilaurate were added and reacted at 80 ° C. for 3 hours. Next, a pre-adjusted carboxylate solution consisting of 50 parts of methyl ethyl ketone, 19.8 parts of dimethylolpropionic acid and 12.5 parts of triethylamine is added, and further reacted at 80 ° C. for 2 hours to obtain a product solution. Got. After cooling the product solution to 40 ° C., 718 parts of water was added to cause phase inversion, and then the product polyisocyanate and water were subjected to chain extension reaction by refluxing at 40 to 45 ° C. for 12 hours.
Thereafter, methyl ethyl ketone was removed with a rotary evaporator to obtain a polyurethane emulsion (hereinafter referred to as PE-1). The solid content of PE-1 was 35.1% and the viscosity was 600 cps / 25 ° C.
Thus, the obtained polyurethane emulsion was coated on a PET film at a thickness of 150 μm, dried at room temperature for 12 hours, and further dried at 100 ° C. for 30 minutes to obtain a polyurethane-coated colorless transparent film having a thickness of about 53 μm. This film was soft, had a tensile elongation at break of 625%, was tough with a tensile strength at break of 35.6 MPa, and was excellent in water resistance.
In addition, a glass bottle is dipped (immersed) in the obtained polyurethane emulsion, slowly pulled up, and dried at 100 ° C. for 30 minutes with the emulsion attached, to obtain a glass bottle having an outer surface coated with a polyurethane having a thickness of about 27 μm. It was. When this glass bottle was hit with an iron hammer, it was broken into large pieces, but the broken glass did not scatter. On the other hand, when a glass bottle not covered with a film was hit with an iron hammer, it was crushed into small pieces and scattered into pieces.

(Example 2)
To 100 parts by mass of the polyurethane emulsion (PE-1) obtained in Example 1, 1 part by mass of Epolite 100E (manufactured by Kyoeisha Chemical Co., Ltd.) as an epoxy resin was added and mixed. Hereinafter, this is referred to as polyurethane emulsion PE-2. This polyurethane emulsion PE-2 was applied to a thickness of 150 μm and dried at room temperature for 72 hours to obtain a colorless transparent film having a thickness of about 62 μm. This film was soft, had a tensile elongation at break of 550%, was tough with a tensile strength at break of 28.7 MPa, and was excellent in water resistance.
Further, the obtained polyurethane emulsion (PE-2) is dipped (immersed) in a glass bottle, slowly pulled up and dried at room temperature for 24 hours with the emulsion attached, and a colorless transparent film having a thickness of about 29 μm is formed on the outside. A glass bottle coated with is obtained. When this was hit with an iron hammer, it was broken into large pieces, but the broken glass did not scatter.

(Example 3)
A four-necked flask equipped with a stirrer, thermometer, nitrogen seal tube, and cooler was charged with 94 parts of polyol (2) and 25 parts of polyol (3), then 100 parts of isophorone diisocyanate and 0.1 part of dibutyltin dilaurate. 1 part and 9 parts of dimethylolpropionic acid dissolved in 9 parts of N methylpyrrolidone were added and reacted at 80 ° C. for 3 hours. Thereafter, 9 parts of triethylamine was mixed to obtain a liquid product solution. After completion of the reaction, add 356 parts of water to invert the phase,
Thereafter, the product solution was subjected to chain extension reaction between the remaining polyisocyanate and water by refluxing at 40 to 45 ° C. for 12 hours to obtain a polyurethane emulsion (PE-5). PE-5 had a solid content of 39.0% and a viscosity of 650 cps / 25 ° C.
This PE-5 was applied to a thickness of 150 μm, dried at room temperature for 12 hours, and further dried at 100 ° C. for 30 minutes to obtain a colorless transparent film having a thickness of about 62 μm. This film was soft, had a tensile elongation at break of 550%, was tough with a tensile strength at break of 28.7 MPa, and was excellent in water resistance.
Moreover, a glass bottle is dipped (immersed) in the obtained polyurethane emulsion (PE-5), slowly pulled up and dried at 100 ° C. for 30 minutes with the emulsion attached, and a colorless transparent film having a thickness of about 29 μm is formed on the outer side. A glass bottle coated with is obtained. When this was hit with an iron hammer, it was broken into large pieces, but the broken glass did not scatter.

Example 4
To 100 parts by mass of the polyurethane emulsion (PE-2) obtained in Example 2 above, 10 parts by mass (except white) or 50 parts by mass (white) of an aqueous pigment, and 0.5 parts by mass of an aqueous thickener (liquid paint) ) Or 3 parts by mass (putty-like paint) was added to create a paint.
The blending amounts of the pigment and the thickener were as shown in Table 1, and the amounts of the pigment and the thickener were adjusted so that the black paint was putty and the other colors were liquid. In addition, the quantity in the table | surface of each color is equivalent to said prescription mass part.

このようにして得られた絵具で、透明ガラス板上に、まずパテ状黒色絵具をプラスチックのスポイトを用いて枠状に配置し、絵の外郭を形成した。十分乾燥した後に、外郭の内部を各色の液状絵具で彩色して、ステンドガラス調被覆板を形成した（図１参照）。
このガラス板に鉄ハンマーを打ち付けガラスを破壊させると、ガラスにヒビが入ったが完全には割れず、破砕片の飛散もなかった。一方、透明ガラス板状に絵を書かずに鉄ハンマーを打ち付けると、ガラスは割れて飛散した。

With the paint thus obtained, a putty-like black paint was first placed in a frame shape using a plastic dropper on a transparent glass plate to form an outline of the picture. After sufficiently drying, the inside of the outline was colored with liquid paints of various colors to form a stained glass-tone coated plate (see FIG. 1).
When this glass plate was struck with an iron hammer to break the glass, the glass cracked, but it was not completely broken and the fragments were not scattered. On the other hand, when an iron hammer was struck without writing a picture on a transparent glass plate, the glass broke and scattered.

(Comparative Example 1)
In a four-necked flask equipped with a stirrer, thermometer, nitrogen seal tube, and cooler, 150 parts of methyl ethyl ketone, 72 parts of polyol (1), 30.4 parts of polyol (2), and 13.2 of polyol (3) Then, 100 parts of isophorone diisocyanate and 0.1 part of dibutyltin dilaurate were added and reacted at 80 ° C. for 3 hours.
Subsequently, a carboxylate solution consisting of 50 parts of methyl ethyl ketone, 15.6 parts of dimethylolpropionic acid, and 9.84 parts of triethylamine prepared in advance was added and reacted at 80 ° C. for 2 hours to obtain a product solution. .
The product solution was cooled to 40 ° C. or lower, charged with 474 parts of water, phase-inverted, and cooled to room temperature. A preliminarily prepared amine solution consisting of 50 parts of water and 15.3 parts of hydrazine hydrate was added dropwise, followed by a chain extension reaction for 1 hour. After completion of the reaction, the reaction was allowed to stand at room temperature for 12 hours in this state, and the reaction was terminated by a reaction between the residual isocyanate group and an excessive amount of water penetrating into the cell. Thereafter, methyl ethyl ketone was removed by a rotary evaporator to obtain a polyurethane emulsion (CPE-1). CPE-1 had a solid content of 35.1% and a viscosity of 450 cps / 25 ° C.
Thus, the obtained polyurethane emulsion was coated on a PET film to a thickness of 150 μm, dried at room temperature for 12 hours, and further dried at 100 ° C. for 30 minutes to obtain a colorless transparent film having a thickness of about 51 μm. This film was soft, had a tensile elongation at break of 300%, was tough with a tensile breaking strength of 44.4 MPa, and was excellent in water resistance. A glass bottle was dipped (immersed) in the obtained polyurethane emulsion. The glass bottle was slowly pulled up and dried at 100 ° C. for 30 minutes with the emulsion attached to obtain a glass bottle with a colorless transparent film having a thickness of about 25 μm coated on the outside.
When this was hit with an iron hammer, it was broken into large pieces, and broken pieces of glass were scattered.

As described above, the polyurethane cured product obtained by curing the emulsion obtained by the method for producing a polyurethane emulsion of the present invention has high adhesion to an object to be coated, flexibility and elasticity with a tensile elongation at break of 500% or more, and tensile fracture. It has a toughness and water resistance of 20 MPa or more.
This polyurethane cured product can be applied to coatings and paints on glass, acrylic, PET, and the like. When a polyurethane layer is formed on the glass surface using this polyurethane emulsion, the urethane layer does not break even if the glass breaks. Holds debris to prevent splashing.

It is a figure which shows the Example of this invention.

Explanation of symbols

1: Outline 2: Inside the frame

Claims (5)

(I) an isocyanate component (A) comprising one or more organic polyisocyanates;
A polyol component (B) comprising a bifunctional polyol (B1) or a mixture of the bifunctional polyol (B1) and the 2-4 functional polyol (B2);
A polyol component (C) having a carboxyl group;
The
A step of producing a prepolymer (D) by reacting under conditions of isocyanate group / active hydrogen group (equivalent ratio) = 1.0 / 0.5 to 0.9;
(II) a step of dispersing the obtained prepolymer (D) in water under a condition of 130 parts by weight or more of water with respect to 100 parts by weight of the prepolymer (D) and stirring to make an emulsion;
A process for producing a polyurethane emulsion comprising The method for producing a polyurethane emulsion according to claim 1, wherein an aqueous pigment and an aqueous thickener are further added to the emulsion. An isocyanate component (A) composed of one or more organic polyisocyanates;
A polyol component (B) comprising a bifunctional polyol (B1) or a mixture of the bifunctional polyol (B1) and the 2-4 functional polyol (B2);
A polyol component (C) having a carboxyl group;
The
Is reacted under the conditions of isocyanate group / active hydrogen group (equivalent ratio) = 1.0 / 0.5 to 0.9 to obtain a prepolymer (D), which was neutralized,
The emulsion obtained by adding 130 parts by mass or more of water to 100 parts by mass of the prepolymer (D) and refluxing at 40 to 45 ° C. is slowly generated by a slow reaction between the residual polyisocyanate component and water. A polyurethane emulsion characterized by reacting a diamine with a residual polyisocyanate component to complete the reaction. The polyurethane emulsion according to claim 3, further comprising an aqueous pigment and an aqueous thickener added to the emulsion. A polyurethane-coated glass, wherein the polyurethane emulsion of claim 4 or 5 is applied to a glass surface.

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