JP3125410B2 - Coating composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to paints, adhesives, surface treatment agents having excellent mechanical strength, hydrolysis resistance, durability, solvent resistance, and abrasion resistance and having high surface hardness. The present invention relates to a coating agent used for a sealing agent and the like.

[0002]

2. Description of the Related Art Polyurethane emulsions provide a coating film having abrasion resistance, adhesion and rubber elasticity.
It is widely used for paints, adhesives and coatings. However, as compared with the properties obtained from the solvent-based polyurethane resin, the properties of the coating film obtained from the emulsion were considerably inferior in points such as solvent resistance and water resistance. In particular, in the case of a polyurethane emulsion using a polyester diol, not only the hydrolysis resistance of the film formed is poor, but also the problem that the molecular weight decreases during storage of the emulsion actually occurs.

Further, when polyether diol is used, there is a problem that heat resistance is insufficient and satisfactory physical properties cannot be obtained, and when applied to artificial leather, sufficient wear resistance cannot be obtained. For these improvements, it has generally been made to make a self-crosslinkable latex. For example,
Carboxylated latex and melamine-formaldehyde resin or urea-formaldehyde resin, carboxylated latex and aziridine compound (JP-A-55-1)
No. 64244), and a combination of a latex into which a functional group having reactivity with an isocyanate such as a hydroxyl group is introduced, and a blocked isocyanate.

However, when a formalin-based resin is used, unreacted formalin is contained, and there is a problem that this is dissipated into the atmosphere. This is not only unfavorable in working environment but also a small amount of formalin is produced from the final product. Due to the release, the effect cannot be ignored in some applications. Further, the aziridine compound has a problem in that its use or method of use is limited due to its toxicity. Further, in the case of blocked isocyanate, there is a problem that it cannot be used depending on the application because the crosslinking temperature is relatively high.

In recent years, oxazoline compounds have been introduced as a new crosslinking agent which solves these problems as a low-toxicity crosslinking agent which can be crosslinked at a relatively low temperature (Japanese Patent Publication No. Sho 6).
3-48884, JP-A-2-99537). However, also in the curing system, the latex requires a functional group having reactivity with oxazoline, and at this time, if the amount of the functional group introduced is small, the curing does not proceed sufficiently, and if it is too large, it becomes alkali swellable, The problem of reduced alkali resistance and eventually water resistance remained.

[0006]

Accordingly, a self-curing latex which retains water resistance and alkali resistance even when a functional group such as a carboxyl group is introduced, and is used in combination with a low-toxicity curing agent. There is a demand for a coating agent composition in which a cured film is excellent in mechanical strength, abrasion resistance, and adhesion to a substrate, and has high surface hardness. An object of the present invention is to provide such a coating composition.

[0007]

Means for Solving the Problems The present inventors have a good film forming property when practically used to solve the above-mentioned problems,
As a result of diligent research on a coating composition of a polyurethane emulsion that gives a coating film with excellent water resistance, durability, abrasion resistance and solvent resistance and a high surface hardness, a carboxylated polyurethane emulsion using an amorphous polycarbonate diol was obtained. The present inventors have found that the problem can be solved by combining the compound with an oxazoline compound, and completed the present invention.

That is, the present invention relates to an organic diisocyanate and a compound represented by the following general formulas (1), (2) and (3).
It consists of repeating units, and the ratio of (1) and (2) is 9: 1 to 1
1: 9, with respect to the total amount of (1), (2) and (3),
The total of one or more of (3) is 0 to 10%
(However, the percentage and the percentage are the percentage of the number of the repeating units.
And percentage. ) Aliphatic polycarbonate diol
A non-crystalline polycarbonate diol,

[0009]

Embedded image A diol represented by the following general formula (4);

[0010]

Embedded image Trimethylolethane and trimethylolp as required
Lopan, sorbitan, glycerin, pentaerythritol
Urethane consisting of a compound selected from sorbitol
Prepolymers, short-chain diols, diamines,
Consists of a reaction product with a chain extender selected from functional amines
Polyurethane emulsion (A), characterized in that
And 2-vinyl-2-oxazoline, 2-vinyl-4
-Methyl-2-oxazoline, 2-vinyl-5-methyl
-2-oxazoline, 2-isopropenyl-2-oxa
Zoline, 2-isopropenyl-4-methyl-2-oxa
Zoline, 2-isopropenyl-5-ethyl-2-oxa
One or more addition-polymerizable oxo selected from zoline
Copolymerizable with sazoline (a) and (a) if necessary
Comprising a polymer (B) obtained by polymerizing a monomer (b)
The present invention relates to a coating agent composition.

The present invention will be described below. Examples of the amorphous polycarbonate diol used in the present invention include those that are viscous liquids at room temperature. Among them, aliphatic polycarbonate diols are preferred, and more preferably,
The repeating unit consists of the following general formulas (1), (2) and (3) , wherein the ratio of (1) and (2) is 9: 1 to 1: 9,
With respect to the total amount of (1), (2), and (3) , the sum of one or more of (3) is 0 to 10% (however, the%
And the ratio indicate % and the ratio of the number of repeating units. ) Aliphatic polycarbonate diols.

[0012]

Embedded image (M and n are integers of 4 to 6 and m ≠ n, R 'and R "are alkylene having 2 to 6 carbon atoms)

The organic diisocyanate used in the present invention includes, for example, 2,4-tolylene diisocyanate,
2,6-tolylene diisocyanate and its mixture (TDI), diphenylmethane-4,4'-diisocyanate (MDI), naphthalene-1,5-diisocyanate (NDI), 3,3'-dimethyl-4,4'-biphenylene Diisocyanate (TODI), crude TDI,
Polymethylene polyphenyl diisocyanate, crude MD
I and other aromatic diisocyanates, xylylene diisocyanate (XDI), phenylene diisocyanate and other aliphatic diisocyanates, and 4,4'-methylenebiscyclohexyl diisocyanate (hydrogenated MD
Aliphatic diisocyanates such as I), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), and cyclohexane diisocyanate (hydrogenated XDI). Compounds having one hydrophilic center and at least two isocyanate-reactive groups include compounds of the general formula

[0014]

Embedded image

Wherein R is an alkyl group having 1 to 3 carbon atoms, such as 2,2-dimethylolpropionic acid, 2,2-dimethylolbutyric acid and 2,2-dimethylol Valeric acid and the like . If this is actually used <br/> et al, was added trimethylamine, triethylamine, tri -n- propylamine, tributylamine, amines such as triethanolamine, sodium hydroxide, potassium hydroxide, ammonia, or the like Used
Is good.

Naturally, suitable surfactants, such as higher fatty acids, resin acids, acidic fatty alcohols, sulfates, higher alkyl sulfonates, alkylaryl sulfonates, sulfonated castor oil, sulfosuccinates and the like. The emulsion stability may be maintained by using a combination of an anionic surfactant or a nonionic surfactant represented by a known reaction product of ethylene oxide with a long-chain fatty alcohol or a phenol. Used in the present invention, as a compound having at least three isocyanate-reactive groups, trimethylolethane, trimethylolpropane, sorbitan, glycerol, pentaerythritol, sorbitol Le, and the like.

The chain extenders used in the present invention include short-chain diols such as ethylene glycol and 1,4-butanediol, ethylenediamine, propylenediamine, hexamethylenediamine, tolylenediamine, xylylenediamine, diphenyldiamine, diaminodiamine. Diphenylmethane, diaminocyclohexylmethane, piperazine, 2-
Examples include various diamines such as methylpiperazine and isophoronediamine and water, or polyfunctional amines such as diethyltriamine and triethylenetetramine.

The polyurethane emulsion used in the present invention can be obtained as follows. That is, for example, by reacting an organic diisocyanate, an amorphous polycarbonate diol and a compound having one hydrophilic center and at least two isocyanate-reactive groups,
A terminal urethane prepolymer is obtained. In the reaction here, an organic solvent inert to isocyanate such as acetone, methyl ethyl ketone, toluene, dioxane, dimethylformamide, N-methylpyrrolidone, tetrahydrofuran and the like can be used.

Next, if necessary, the obtained prepolymer is neutralized, then emulsified and dispersed in water, and the molecular weight is increased with a chain extender. When the prepolymer reaction is performed using a solvent, for example, it is necessary to remove by a method such as distillation under reduced pressure after completion of the chain extension reaction.

The polymer (B) used in the present invention includes
Polymerizable oxazoline (a) and optionally (a)
A polymer obtained by polymerizing a copolymerizable monomer (b) is used.
However, as used in the examples, Nippon Shokubai Co., Ltd.
Oxazoline-based cross-linking agents that are commercially available from
Can be used. This known oxazoline crosslinking
The agent is disclosed in detail in JP-A-2-99537.
As the addition-polymerizable oxazoline (a),
One selected from the group of the following compounds described in
One or more compounds are used, and if necessary
The copolymerizable monomer (b) to be used is also described in the same JP
What is being used.

2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5
Methyl-2-oxazoline, 2-isopropenyl-2-
Oxazoline, 2-isopropenyl-4-methyl-2-
Oxazoline, 2-isopropenyl-5-ethyl-2-
Oxazoline ,

Of these, 2-isopropenyl-2-oxazoline is preferred because it is industrially available. The amount of the addition polymerizable oxazoline (a) is not particularly limited, but is preferably 5% by weight or more in the polymer (B). If the amount is less than 5% by weight, the degree of curing is insufficient, and durability and water resistance tend to be impaired.

In the present invention, the mixing ratio of the polyurethane emulsion (A) and the polymer (B) is not particularly limited, but the polymer content is 100 parts by weight of the solid content of the polyurethane emulsion (A). (B) Resin content 1
The range is preferably from 50 to 50 parts by weight. If the amount is less than 1 part by weight, the degree of curing is insufficient, and durability and water resistance are impaired. If the amount is more than 50 parts by weight, adhesion to a substrate tends to be impaired.

When the present coating composition is put into practical use, extenders or fillers such as clay, talc, calcium carbonate, mica, etc., white pigments such as titanium white, dyes, polyvinyl alcohol, methyl cellulose,
Thickeners such as carboxymethylcellulose, starch, dextrin, dispersants, emulsifiers, wetting agents, defoamers such as silicone oil, deicing agents such as ethylene glycol, N-methylpyrrolidone, triethylene glycol di- (2- Various additives such as a film forming aid such as ethyl butyrate), di (2-ethylhexyl) adipate, diethyl phthalate, and diphenyl phthalate may be appropriately added and used.

[0025]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. Parts in the examples mean parts by weight.

Synthesis example of amorphous polycarbonate diol
(1) In a reactor equipped with a stirrer, a thermometer, a fractionating tower, and a vacuum pump, 416 parts (4.0 mol) of 1,5-pentanediol were added.
And 472 parts (4.0 mol) of 1,6-hexanediol were added, and 1.84 parts (0.08 mol) of sodium metal was added at 70 to 80 ° C. with stirring. After the sodium had completely reacted, 472 parts (8.0) of diethyl carbonate were introduced. As the reaction temperature was raised to 95-100 ° C, ethanol began to distill. The temperature was gradually raised to 160 ° C. in about 6 hours.

During this time, ethanol containing about 10% of diethyl carbonate was distilled off. Thereafter, the pressure in the reactor was further reduced to 10 mmHg or less, and the reaction was carried out at 200 ° C. for 4 hours under strong stirring. The resulting polymer was dissolved in dichloromethane after cooling, neutralized with dilute acid, washed repeatedly with water several times, dehydrated with anhydrous sodium sulfate, distilled off the solvent, and further distilled at 2-3 mmHg at 140 ° C. Let dry for hours. The obtained amorphous polycarbonate diol (hereinafter C)
Abbreviated as 5,6-PCDL. ) Has a number average molecular weight of 200
It was 0.

Synthesis example of amorphous polycarbonate diol
(2) Synthesis example (1) using 360 parts (4.0 mol) of 1,4-butanediol instead of 1,5-pentanediol.
Amorphous polycarbonate diol (hereinafter C)
4,6-PCDL). The C4,6-PCDL had a number average molecular weight of 2,000.

Example of Synthesis of Amorphous Polycarbonate Diol
(3) Synthesis example (1) using 360 parts (4.0 mol) of 1,4-butanediol instead of 1,6-pentanediol.
In the same manner as described above, an amorphous polycarbonate diol (hereinafter abbreviated as C4,5-PCDL) was obtained. The C4,5-PCDL
Had a number average molecular weight of 2,000.

Production Example of Polyurethane Emulsion (1 ) 500 parts of the above C5,6-PCDL (molecular weight: 2,000)
126 parts of hexamethylene diisocyanate (HDI),
58.5 parts of dimethylolpropionic acid whose carboxyl group was neutralized with triethylamine, methyl ethyl ketone (M
EK) (1647 parts) was placed in a reactor having a reflux condenser, a thermometer, and a stirrer, and a urethanization reaction was performed at 80 ° C for 4 hours to obtain an NCO-terminated prepolymer solution.

The prepolymer solution was gradually added to 1562 parts of distilled water set at a temperature of 30 ° C. while stirring to prepare an emulsion of the prepolymer solution. Then a 20% aqueous solution of isophorone diamine (IPDA) 1
After adding 06.5 parts over 30 minutes, the temperature was raised to 40 ° C., and the mixture was reacted for 1 hour to increase the molecular weight. The MEK was removed under reduced pressure to obtain a polyurethane emulsion (1) having a solid content of 30%.

Production example of polyurethane emulsion (2)
(6) With a composition as shown in Table 1, polycarbonate diol was converted to C4,6-PCDL or C4,5-PCDL, C
6 -PCDL (Carbodiol D- manufactured by Toagosei Co., Ltd.)
2000), a polyether polyol (PTMG manufactured by Asahi Kasei Kogyo Co., Ltd.), and a polyester polyol (Polylite ODX-668 manufactured by Dainippon Ink Co., Ltd.) except that solids were prepared in the same manner as in the polyurethane emulsion production method (1). Polyurethane emulsions (2), (3), (4), (5), and (6) were obtained at a concentration of 30%.

Production example of polyurethane emulsion (7)
(9) Polyurethane emulsion (7) having a solid content of 30% in the same manner as in the production example (1) or (2) of the polyurethane emulsion except that diisocyanate was replaced with isophorone diisocyanate in the composition shown in Table 1. (9) was obtained.

[0034]Production example of polyurethane emulsion (1
0) Other than replacing part of the diol with trimethylolpropane
Is similar to the polyurethane emulsion production example (9).
To give a 30% solids polyurethane emulsion (9)
Obtained.

Example 1 A coating agent (1) prepared according to the formulation shown in Table 2 was
Using a knife coater, 30 g of a plain woven cloth of 46 yarns / in using nylon 66 long fiber yarn (420d / 70f)
/ M ² (weight after drying), dried at 100 ° C. for 5 minutes, and then cured at 150 ° C. for 5 minutes to obtain a coated cloth. Various physical properties were evaluated using the obtained coated cloth. Table 3 shows the results. The evaluation method in this example is as follows.

1. Treatment conditions Moisture heat treatment: 10 at 50 ° C and 95% RH atmosphere
Treating the coated cloth for 00 hours. 2. Tensile strength (kgf / in) Measured by the labeled strip method based on JIS-L-1036. The value of the heat-moisture treated product is indicated by the retention of tensile strength relative to the value of the untreated product.

3. Tear strength (kgf) Measured by the single tongue method based on JIS-L-1096. The value of the heat-moisture treated product is indicated by the retention of tear strength relative to the value of the untreated product. 4. Adhesive force (kgf / in) A sample with a width of 25 mm and a length of 200 mm was prepared, and the coated surfaces of the two samples were overlapped with each other at an end of 3 cm.
Using a two-pack polyurethane hot melt adhesive, heat and pressure bonding (adhesion area becomes 25 mm x 30 mm), and measure the breaking strength of the bonded part when the both ends of the strip are gripped and pulled.

5. Tackability Two sample pieces of 50 mm width and 50 mm length are overlapped with each other on the coating surface, sandwiched by glass plates from both sides, and placed on a top with a load of 3 kg, left in an oven at 70 ° C. for 24 hours, and taken out. At room temperature, the two sample pieces are peeled off, and the tackiness is determined based on the following criteria. ○ No tack at all △ Adhesive, scratched surface × Both sides stick together and do not separate

6. Texture Hand-rubbed the coated cloth and judged according to the following criteria. ◎ Extremely flexible ○ Flexible △ Somewhat hard and rough × Hard and hard

Examples 2 and 3 and Comparative Example 7 Coating agents were prepared according to the formulations shown in Table 2, and various physical properties were measured in the same manner as in Example 1. Table 3 shows the results.

Comparative Examples 1 to 3 Various coating agents were prepared according to the formulation examples shown in Table 2 and various physical properties were measured in the same manner as in Example 1. Table 3 shows the results.

Example 5 As shown in Table 4, polyurethane emulsion (7) 1
00 parts of oxazoline-based crosslinking agent (Nippon Shokubai Co., Ltd. et
3 parts of Pocross K-1010E solids ( 40%) were added, and the following physical properties were measured.

1. Pencil hardness A polyurethane emulsion composition is applied on a glass plate and dried at 140 ° C. for 2 minutes to obtain a coating film having a thickness of about 30 μ. The pencil hardness is measured according to JIS-K-5400.

2. Adhesiveness A polyurethane emulsion composition is applied to a soft PVC sheet and dried at 140 ° C. for 2 minutes to obtain a coating film having a thickness of about 30 μ. Adhesion was measured according to the cross-cut rub method of JIS-K-5400, To display.

3. Abrasion resistance A polyurethane emulsion composition is applied on a glass plate and dried at 140 ° C. for 2 minutes to obtain a coating having a thickness of about 30 μm. The weight loss after 700 rotations was measured using a wear wheel CS-17 with a load of 500 g and a taper abrasion tester.

4. The water-resistant polyurethane emulsion composition was coated on a polyvinyl chloride sheet, dried at 140 ° C. for 2 minutes, immersed in room temperature water for 24 hours, and visually evaluated for the degree of whitening and deterioration of the film.

5. NaOH resistance After leaving the PVC sheet coated with the polyurethane compound in a 5% NaOH aqueous solution at room temperature for 24 hours, the state of the film was visually judged. Table 4 shows the obtained physical properties.

Examples 6 to 7 Samples were prepared by applying the polyurethane emulsion composition obtained in the same manner as in Example 5 according to the formulation shown in Table 4, and various physical properties were determined in the same manner as in Example 5. It was measured. Table 4 shows the results.

Comparative Examples 4 to 6 Samples were prepared by applying the polyurethane emulsion compound obtained in the same manner as in Example 5 with the compounding recipe shown in Table 4, and various physical properties were obtained in the same manner as in Example 5. It was measured. Table 4 shows the results.

[0050]

It is apparent that the coating composition of the present invention gives a coating film having excellent mechanical strength, hydrolysis resistance, NaOH resistance and abrasion resistance and having a high surface hardness.

[0051]

[Table 1]

[0052]

[Table 2]

[0053]

[Table 3]

[0054]

[Table 4]

Continuation of the front page (56) References JP-A-2-99537 (JP, A) JP-A-2-107767 (JP, A) JP-A-2-108227 (JP, A) JP-A-60-15473 (JP) , A) John T .; Zermanl, Journal of Water Borne Coatings, 1984, p2-6 (58) Fields investigated (Int. Cl. ⁷ , DB name) C09D 1/00-201/10 CA (STN) REGISTRY (STN)

Claims (1)

(57) [Claims] 1. An organic diisocyanate having the following general formula
From the repeating units represented by (1), (2) and (3)
And the ratio of (1) and (2) is 9: 1 to 1: 9,
(1), (2), a kind of (3) for the total amount of (3)
Or the total of two or more is 0 to 10% (however,
And percentage indicate the percentage and percentage of the number of repeating units.
You. ) Amorphous consisting of aliphatic polycarbonate diol
And polycarbonate diol, [Formula 1] A diol represented by the following general formula (4) : Trimethylolethane and trimethylolp as required
Lopan, sorbitan, glycerin, pentaerythritol
Urethane consisting of a compound selected from sorbitol
Prepolymers, short-chain diols, diamines,
Consists of a reaction product with a chain extender selected from functional amines
Polyurethane emulsion, characterized in that (A), you
And 2-vinyl-2-oxazoline, 2-vinyl-4
-Methyl-2-oxazoline, 2-vinyl-5-methyl
-2-oxazoline, 2-isopropenyl-2-oxa
Zoline, 2-isopropenyl-4-methyl-2-oxa
Zoline, 2-isopropenyl-5-ethyl-2-oxa
One or more addition-polymerizable oxo selected from zoline
Copolymerizable with sazoline (a) and (a) if necessary
Comprising a polymer (B) obtained by polymerizing a monomer (b)
A coating agent composition.