JPH11335437A - Water-based urethane resin with excellent gloss and removability - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous urethane resin which forms a film having excellent gloss when applied to a substrate, and which is excellent in the removability of the film from the substrate. SOLUTION: In an aqueous urethane resin comprising an organic diisocyanate compound, a polyol compound, an ionic group-forming compound and, if necessary, a chain extender, the polyol compound is obtained by reacting a bisphenol compound with an alkylene oxide having 2 to 4 carbon atoms. An aqueous urethane resin which is a bisphenol skeleton-containing polyether polyol having a number average molecular weight of 300 to 2500 and has excellent number gloss and removability, wherein the number average molecular weight of the aqueous urethane resin is in the range of 2000 to 15000.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous urethane resin having excellent gloss and removability. More specifically, the present invention relates to an aqueous urethane resin which forms an excellent glossy film when dried after being applied to a base material and is easily removed with water when the film is removed from the base material so that it can be easily removed. .

[0002]

2. Description of the Related Art Water-based polishing agents used as floor waxes, furniture waxes and the like are required to have various properties.
For example, when taking floor wax as an example, important properties required include, first of all, the ability to impart gloss and aesthetics to the surface of the base material, the physical properties of the coating, and the durability. It is necessary that an old film be easily re-dissolved and easily removed during work or the like, and that a new film can be re-applied thereon.

[0003] Conventional aqueous polishes have good gloss when applied to a substrate, but have poor removability from the substrate and are difficult to remove with water. was there. As a result, there have been problems such as damage to the surface of the base material and troublesome removal work. Conversely, if the removability is to be improved, the gloss is not always satisfied, and there is no finding that satisfies both the gloss and the removability.

Various compositions using aqueous acrylic resins, aqueous urethane resins and the like as aqueous polishes have been proposed. For example, Japanese Patent Application Laid-Open No. 62-205168 discloses the use of a urethane resin containing a carboxylic acid and / or a carboxylate and having an acid value of 40 to 200 mgKOH / g. Although the removability was good, the removability with water was not always sufficient, and the gloss after coating was not sufficient.

[0005] Japanese Patent Application Laid-Open No. Hei 8-92529 discloses that by crosslinking an aqueous urethane resin with calcium, a film formed when applied to the floor surface is toughened and durability and abrasion resistance are improved. Have been. However, although the introduction of the crosslinked structure improves various durability, the removability of the film was not satisfactory. Japanese Patent Application Laid-Open No. 8-109353 discloses α, β-containing a carboxyl group or a salt thereof and a carbonyl group in the molecule.
It is disclosed that crosslinking is performed using an unsaturated carboxylic acid-based polymer or a urethane-based polymer with a hydrazine group-containing compound or the like. However, similar to the above, the removability of the obtained film was not satisfactory.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object the high glossiness and excellent removability which were not satisfied with conventional aqueous urethane resins and aqueous acrylic resins. An object of the present invention is to provide an aqueous urethane resin having both of the above.

[0007]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventor has found that a polyether polyol having a specific structure is used as a component of the aqueous urethane resin, and the number average molecular weight of the resin is Was determined to be a lower specific range than in the prior art, whereby an aqueous urethane resin satisfying both the gloss and the removability was obtained. That is, the gist of the present invention is to provide an aqueous urethane resin comprising an organic diisocyanate compound, a polyol compound, an ionic group-forming compound and, if necessary, a chain extender, wherein the polyol compound is a bisphenol compound having 2 to 4 carbon atoms.
A bisphenol skeleton-containing polyether polyol having a number average molecular weight of 300 to 2500 obtained by reacting the above alkylene oxide, wherein the aqueous urethane resin has a number average molecular weight in the range of 2,000 to 15,000. Water-based urethane resin with excellent properties. Although a water-soluble urethane resin obtained by copolymerizing a polyether polyol containing a bisphenol skeleton is known, the conventional one has a high molecular weight of 20,000 to 30,000 or more, and in terms of the removability aimed at by the present invention. Not enough.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The aqueous urethane resin in the present invention comprises an organic diisocyanate compound, a polyol compound, an ionic group-forming compound and, if necessary, a chain extender. Examples of the organic diisocyanate compound include 2,4-tolylene diisocyanate and a mixture of this and 2,6-tolylene diisocyanate (abbreviated as TDI), 4,4'-diphenylmethane diisocyanate (MDI), and 1,5-naphthalenediisocyanate (NDI ), Isophorone diisocyanate (IP
DI), 4,4'-dicyclohexylmethane diisocyanate (H12MDI), hexamethylene diisocyanate (HMDI), xylylene diisocyanate (XD
I) and hydrogenated TDI and the like, and these can be used alone or in combination. The use amount of these organic diisocyanate compounds is usually about 15 to 50% by weight based on all components constituting the urethane resin.

The polyol compound which is a component of the aqueous urethane resin of the present invention needs to be a polyether polyol having a bisphenol skeleton. The polyether polyol is obtained by adding one or more alkylene oxides having 2 to 4 carbon atoms selected from ethylene oxide, propylene oxide, butylene oxide, and the like to a bisphenol compound.

As the bisphenol compound, bisphenol A (4,4'-dihydroxydiphenyl-2,2-
Propane), bisphenol F (4,4'-dihydroxydiphenylmethane), bisphenol S (4,4'-dihydroxydiphenylsulfone), bisphenol AF
(4,4'-hexafluoroisopropylidene diphenol), 4,4'-biphenol, 4,4'-thiodiphenol, 4,4'-dihydroxydiphenyl ether and the like, and substituted derivatives thereof.

The number average molecular weight of the polyol compound must be 300 to 2500. If the molecular weight is too small, the continuity of the film when the resulting urethane resin is applied to a substrate is reduced, and a smooth film cannot be formed. Further, the cohesive force of the resin is increased, so that the removability tends to decrease. On the other hand, if the molecular weight is too large, the glossiness when the urethane resin is applied to the base material is not sufficient, and the physical properties of the coating tend to deteriorate, such as an increase in tackiness and a reduction in coating strength. The preferred range of this molecular weight is 500-2000, more preferably 500-15.
00.

[0012] Such a polyether polyol can be obtained as a commercial product. For example, the bisphenol A has a number average molecular weight of 300
As a product of ~ 2,500, a trade name of Adeka Polyether BPX-11, BPX-33, BPX-55, BPX-100 manufactured by Asahi Denka Kogyo Co., Ltd.
0, BPX-2000 etc. can be used. The main component of the polyol compound is the polyether polyol, but other polyols can be added as long as the performance is not affected. The usage amount of these polyol compounds is usually about 25 to 75% by weight based on all components constituting the urethane resin. As the ionic group-forming compound, both an anionic type and a cationic type can be used.

Examples of the anionic type include those having a carboxyl group, such as dimethylolpropionic acid, dimethylolbutanoic acid, 1-carboxy-1,5-pentylenediamine, 3,5-diaminobenzoic acid, and the like. Examples include half ester compounds of triol with maleic anhydride or phthalic anhydride, and those having a sulfonate alkali metal base include 2-sulfo-1,4-butanediol sodium salt and 5-sulfo-di- β-hydroxyethyl isophthalate sodium salt and the like.

When a compound containing a carboxyl group is used, a neutralizing agent such as triethylamine, monoethanolamine, diethanolamine, triethanolamine, triethylenediamine, dimethylaminoethanol or the like is used as a neutralizing agent to form a carboxyl group salt and render it hydrophilic. An alkali metal compound such as an amine, sodium hydroxide, or potassium hydroxide is used. The neutralization ratio for the carboxyl group is usually 50 to 100 mol%.

Examples of the cationic type include N-methyldiethanolamine, N-methylethanolamine, triethanolamine and the like. When these tertiary nitrogen compounds are used, hydrochloric acid, acetic acid, propionic acid, lactic acid and the like are used as neutralizing agents. The neutralization ratio for tertiary nitrogen is usually 50 to 10
0 mol%. Of the ionic group-forming compounds, the anionic type containing a carboxyl group is preferred from the viewpoints of availability of raw materials, easy handling, and ease of resin production. In order to enhance the removability of the film, it is desirable to use an alkali metal compound having a low volatility or an amine having a high boiling point among the neutralizing agents. The amount of the ionic group-forming compound to be used is usually 3 to 3 with respect to all components constituting the urethane resin.
It is about 20% by weight.

Examples of the chain extender include ethylene glycol, propylene glycol, 1,4-butanediol,
Short-chain diols such as 1,3-butanediol, neopentyl glycol, 3-methylpentanediol, 1,6-hexanediol, hydrazine, ethylenediamine, propylenediamine, hexamethylenediamine, phenylenediamine, xylylenediamine, isophoronediamine, Diamines such as piperazine, water, and the like. These may be used alone or in combination of two or more. The use amount of these chain extenders is usually about 2 to 20% by weight based on all components constituting the urethane resin. However, since the ionic group-forming compound also serves as a chain extender, it may be used in some cases. The chain extender may not be used.

The number average molecular weight of the aqueous urethane resin to be used in the present invention must be in the range of 2,000 to 15,000. More preferred molecular weight is 3000
12000, most preferably 3000 to 1000
It is in the range of 0. When the number average molecular weight is less than 2,000, the removability of the film is good, but the physical properties are inferior and it is not practical. When the number average molecular weight exceeds 15,000, the film properties are good, but the removability is poor.

The amount of ionic groups in the urethane resin is usually about 1 to 7% by weight, preferably 1 to 5% by weight, more preferably 1.5 to 3.5% by weight, based on resin solids.
% By weight. If the ionic group content is too small, not only does the self-emulsifying property of the urethane resin become insufficient, the average particle size of the urethane resin becomes large, and the dispersion stability becomes poor, but also the gloss is hardly produced because the film is difficult to form densely and smoothly. Tend to be. On the other hand, if the ionic group content is too large, the film properties and water resistance tend to decrease. The average particle diameter of the urethane resin is preferably smaller from the viewpoint of gloss, and is usually 0.4
μm or less, preferably 0.2 μm or less.

In the method for producing the aqueous urethane resin of the present invention, the above-mentioned organic diisocyanate compound, polyol compound, ionic group-forming compound and, if necessary, a chain extender are added to N-methyl-2-pyrrolidone, acetone, methyl ethyl ketone or the like. In the presence or absence of a catalyst such as an organic tin compound such as dibutyltin dilaurate, dibutyltin dioctoate, or stannas octoate, or a tertiary amine compound such as triethylamine or triethylenediamine in a solvent alone or in combination. After the reaction at ℃, neutralization with the above neutralizing agent, water is added, phase inversion and emulsification is carried out, and if necessary, a solvent removal treatment is carried out to produce an aqueous urethane resin (solution method).

As another method, the above-mentioned organic diisocyanate compound, polyol compound and ionic group-forming compound can be prepared by using a solvent such as N-methyl-2-pyrrolidone, acetone, methyl ethyl ketone alone or in combination in the presence of the catalyst or After reacting at 50 to 100 ° C. in the absence of an isocyanate group-terminated prepolymer, neutralize, add water, phase invert and emulsify, extend the chain with diamine or water, and remove the solvent if necessary. Manufacturing method (prepolymer mixing method)
Is mentioned.

In any of the production methods, the urethane resin of the present invention is obtained as an emulsified dispersion in water, and the resin solid content in this emulsified dispersion is usually 20 to 50% by weight. In the present invention, since the number average molecular weight of the urethane resin needs to be controlled within the above range, the former solution method is preferred as a production method because the molecular weight can be more easily controlled. The following shows an example of a recipe for producing a urethane resin having a molecular weight of 2,000 to 15,000 using each component constituting the urethane resin of the present invention.

1 mol of BPX-1000 (number average molecular weight 1000) as a polyol compound, 1 mol of dimethylolpropionic acid (134 molecular weight) as an ionic group-forming compound, and 1 mol of neopentyl glycol (molecular weight 104) as a chain extender When used, the number average molecular weight of a mixture of those active hydrogen containing compounds is calculated as follows. When a urethane resin having a number average molecular weight of 6000 is designed using the above isophorone diisocyanate (IPDI, molecular weight 222) as an organic diisocyanate compound, IPDI
If the required number of molecules is n, then (number average molecular weight of the mixture) × (n + 1) + (molecular weight of IPDI) × n = 6000 413 × (n + 1) + 222 × n = 6000 n 9.52

Accordingly, the required number of moles of IPDI for the above mixture is calculated as follows. In this case, the charged amounts of the reaction raw materials are as follows. BPX-1000 1 mol 1000 g Dimethylolpropionic acid 1 mol 134 g Neopentyl glycol 1 mol 104 g IPDI 2.71 mol 602 g

The aqueous urethane resin according to the present invention is mainly composed of the above-mentioned self-emulsifying aqueous urethane resin containing an ionic group, but the aqueous acrylic resin and the aqueous styrene / acrylic resin within a range that does not affect the performance. , An aqueous vinyl acetate resin, an aqueous epoxy resin, an aqueous silicone resin, an aqueous fluorine-containing resin, an olefin wax, and the like.

In order to further enhance the film-forming property at the time of film formation, in addition to the above-mentioned N-methyl-2-pyrrolidone, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, A cosolvent such as 3-ethoxyethyl propionate may be contained. In addition, various surfactants, antifoaming agents, and the like can be blended to improve the wetting property and leveling property with the base material. The solid content in the liquid mixture at the time of final use is usually 2
About 30% by weight.

The aqueous urethane resin of the present invention can be used for wood, stone,
Resin components such as waxes for floors and furniture, and other cleaning agents for polishing, used for the purpose of applying gloss to the surface by applying it to metal, synthetic resin flooring, wall materials, furniture, etc. to improve the aesthetic appearance. It can be widely used for general household use and business use. As a method of coating the substrate, any method such as flow coating, brush coating, mop coating, roll coating, spray coating, dipping and the like can be used. Drying after coating is well performed at room temperature, and heat drying, hot air drying and the like are not particularly required. The aqueous urethane resin of the present invention is not only excellent in imparting gloss and aesthetic appearance to the substrate surface, but also
Since it has excellent removability from the substrate, it can be easily removed by wiping with water, etc., and recoating is possible even when recoating is required due to dirt or scratches on the surface film. .

[0027]

EXAMPLES Specific examples of the present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the scope of the present invention. In the following examples,% indicates% by weight. Example 1 Adeka polyether was placed in a 2 L four-neck separable flask.
700.0 g of BPX-1000 (number average molecular weight: 1000), 26.8 g of dimethylolpropionic acid, 20.8 g of neopentyl glycol, 92.0 g of N-methyl-2-pyrrolidone, and 0.18 g of dibutyltin dioctoate were charged. After homogeneous dissolution at 100 ° C, isophorone diisocyanate (IP
DI) was added and reacted at 80 ° C. for 10 hours to obtain a polyurethane resin solution.

Next, 6.4 g of sodium hydroxide was added to deionized water 7
An aqueous solution dissolved in 66.7 g is gradually added and phase inversion / emulsification is carried out while neutralizing, and the solid content is 30% and the viscosity is 20 mPa · s / 25 ° C.
(Measured with Tokyo Keiki Seisakusho's EM type viscometer,
The same applies to the following). Average particle size is 0.0
2 μm (measured with a DLS-7000 dynamic light scattering measurement device manufactured by Otsuka Electronics Co., Ltd .; the same applies hereinafter). This is designated as resin A.

Example 2 Adeka polyether was placed in a 2 L four-neck separable flask.
100.0 g of BPX-1000 (number average molecular weight 1000), 28.1 g of dimethylolpropionic acid, 62.4 g of neopentyl glycol, 68.3 g of N-methyl-2-pyrrolidone, 0.034 g of dibutyltin dioctoate, acetone 21
After charging 1.1 g and uniformly dissolving at 40 ° C., 80-TD
151.0 g of I (tolylene diisocyanate having a ratio of 2,4-form to 2,6-form of 80:20) was added and reacted at 55 ° C. for 15 hours to obtain a polyurethane resin solution. Next, an aqueous solution in which 6.3 g of sodium hydroxide was dissolved in 728.5 g of demineralized water was gradually added to cause phase inversion and emulsification. Then, acetone was removed by flowing nitrogen, and the solid content was 30% and the viscosity was 200 mPa · s / 25 ° C. A homogeneous turbid liquid was obtained. The average particle size was 0.08 μm. This is called resin B.

Example 3 Adeka polyether was placed in a 2 L four-neck separable flask.
147.5 g of BPX-33 (number average molecular weight 590), 29.6 g of dimethylolbutanoic acid, neopentyl glycol 2
6.0 g, N-methyl-2-pyrrolidone 69.1 g, dibutyltin dioctoate 0.35 g, acetone 161.4
g of IPDI and uniformly dissolved at 40 ° C.
2.6 g was added and reacted at 55 ° C. for 20 hours to obtain a polyurethane resin solution. Then, an aqueous solution in which 7.2 g of sodium hydroxide was dissolved in 737.5 g of demineralized water was gradually added, and phase inversion was performed.
After emulsification, acetone was removed by flowing nitrogen to obtain a uniform emulsion having a solid content of 30% and a viscosity of 80 mPa · s / 25 ° C. The average particle size was 0.15 μm. This is resin C
And

Example 4 Adeka polyether was placed in a 2 L four-neck separable flask.
200.0 g of BPX-1000 (number average molecular weight 1000), 26.8 g of dimethylolpropionic acid, 20.8 g of neopentyl glycol, 0.18 of dibutyltin dioctoate
g, 124.1 g of N-methyl-2-pyrrolidone and 70
After uniformly dissolving at 12 ° C., 124.8 g of IPDI was added and reacted at 80 ° C. for 14 hours to obtain a polyurethane resin solution. Then 6.4 g of sodium hydroxide was added to 744.
An aqueous solution dissolved in 8 g was gradually added, and phase inversion and emulsification were performed to obtain a uniform finely turbid liquid having a solid content of 30% and a viscosity of 100 mPa · s / 25 ° C. The average particle size was 0.03 μm. This is designated as resin D.

Example 5 Adeka polyether was placed in a 2 L four-neck separable flask.
200.0 g of BPX-1000 (number average molecular weight 1000), 26.8 g of dimethylolpropionic acid, 20.8 g of neopentyl glycol, 0.18 of dibutyltin dioctoate
g, 90.2 g of N-methyl-2-pyrrolidone and 70 ° C.
After uniformly dissolving with 113.2 g of IPDI,
The reaction was carried out at a temperature of 4 ° C. for 4 hours to obtain a polyurethane resin solution. Then, an aqueous solution of 6.4 g of sodium hydroxide dissolved in 751.7 g of demineralized water is gradually added, and the mixture is phase-inverted and emulsified while neutralizing the mixture. I got The average particle size was 0.02 μm. This is designated as resin E.

Comparative Example 1 Adeka polyether BPX-1000 of Example 1 (number average molecular weight
1000) Adeka polyether P-1000 (number average molecular weight 1000
Polypropylene glycol, manufactured by Asahi Denka Kogyo Co., Ltd.), the same raw materials and the same amount were used, and the same production was carried out to obtain a uniform finely turbid liquid having a solid content of 30% and a viscosity of 30 mPa · s / 25 ° C. Obtained. The average particle size was 0.03 μm.
This is designated as resin F.

Comparative Example 2 Adeka polyether was placed in a 2-liter four-neck separable flask.
177.0 g of BPX-33 (number average molecular weight 590), 40.2 g of dimethylolpropionic acid, 31.2 g of neopentyl glycol, 0.12 g of dibutyltin dioctoate,
After 130.1 g of N-methyl-2-pyrrolidone was charged and uniformly dissolved at 70 ° C., 141.9 g of IPDI was added, and 80 ° C.
For 4 hours to obtain a polyurethane resin solution. Next, an aqueous solution in which 9.6 g of sodium hydroxide was dissolved in 780.6 g of demineralized water was gradually added, and the mixture was phase-inverted and emulsified to obtain a homogeneous finely turbid liquid having a solid content of 30% and a viscosity of 20 mPa · s / 25 ° C. The average particle size was 0.23 μm. This is designated as resin G.

Comparative Example 3 Adeka polyether was placed in a 2-liter four-neck separable flask.
100.0 g of BPX-1000 (number average molecular weight 1000), 28.1 g of dimethylolpropionic acid, 62.4 g of neopentyl glycol, 69.4 g of N-methyl-2-pyrrolidone, 0.035 g of dibutyltin dioctoate, and acetone 16
1.8 g was charged and uniformly dissolved at 40 ° C., and then 80-T
156.3 g of DI was added and reacted at 55 ° C. for 22 hours to obtain a polyurethane resin solution. 115.6 g of acetone was added and diluted, and 6.3 g of sodium hydroxide was added to 739 g of demineralized water.
An aqueous solution dissolved in 8 g was gradually added, phase inversion and emulsification was carried out, and acetone was removed by inflow of nitrogen to obtain a solid content of 30%. Viscosity 550mP
A homogeneous turbid liquid of a · s / 25 ° C was obtained. The average particle size is 0.1
It was 2 μm. This is designated as resin H. Table 1 shows the raw material charge weight and the number average molecular weight of the resin solids of Examples 1 to 5 and Comparative Examples 1 to 3.

Examples 6 to 10 Using the aqueous polyurethane resins produced in Examples 1 to 5,
The film performance was evaluated. Using a black vinyl chloride tile as a base material, each liquid was prepared according to the formulation shown in Table 2, and 50
Each solution was applied with a gap of μm and dried at room temperature for 24 hours to obtain a sample. Each evaluation method is as follows. (Non-adhesiveness) Those with no adhesion to the film by touch were evaluated as good, and those with adhesiveness were evaluated as poor. (Gloss) Incident angle 60 according to JIS Z8741
And the reflectivity at a light receiving angle of 60 ° were measured, and the gloss of the specular gloss reference surface was defined as 100 and expressed as a percentage.

(Removability) The test piece film was rubbed 10 times with gauze impregnated with demineralized water, and the degree of removal of the rubbed portion was visually judged as follows. Excellent: completely removed. Good: More than half removed. Bad: Most of the sample remains without being removed. Table 2 shows the evaluation results. In each case, the glossiness of the dried film was high, and the film was easily removed (redissolved) by wiping with water. Comparative Examples 4 to 6 As a result of evaluating the coating in the same manner as in Examples 6 to 10 for the aqueous polyurethane resins produced in Comparative Examples 1 to 3,
There was nothing satisfying both glossiness and removability. Table 2 shows the evaluation results of Examples 6 to 10 and Comparative Examples 4 to 6.

[0038]

[Table 1]

[0039]

[Table 2]

[0040]

The aqueous polyurethane resin of the present invention has both glossiness and removability when applied to a substrate. Therefore, by applying this to floor materials, wall materials, furniture, etc., it is possible to enhance the luster and beauty of the base material,
Since it is easily redissolved in water, an old film can be easily removed by wiping with water or the like without using an alkaline cleaning agent when repainting or the like.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI // C08G 65/28 C08G 65/28

Claims (1)

[Claims] 1. An aqueous urethane resin comprising an organic diisocyanate compound, a polyol compound, an ionic group-forming compound and, if necessary, a chain extender, wherein the polyol compound is obtained by reacting a bisphenol compound with an alkylene oxide having 2 to 4 carbon atoms. An aqueous urethane resin having excellent gloss and removability, wherein the obtained polyether polyol is a bisphenol skeleton-containing polyether polyol having a number average molecular weight of 300 to 2500, and the number average molecular weight of the aqueous urethane resin is in the range of 2000 to 15000.