JPH05202336A - Coating agent composition - Google Patents

Abstract

PURPOSE:To provide a coating agent composition composed of a polyurethane emulsion and giving a coating film having excellent mechanical strength, hydrolysis resistance, NaOH resistance and abrasion resistance and high surface hardness. CONSTITUTION:The objective coating agent composition is produced by adding a specific oxazoline-type cross-linking agent to a polyurethane emulsion composed of an amorphous polycarbonate diol, a compound having one hydrophilic center and >=2 groups reactive with isocyanate and, as necessary, a compound having >=3 groups reactive with isocyanate and a chain extender.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Polyurethane emulsion gives a coating film having abrasion resistance, adhesiveness and rubber elasticity,
It is widely used for paints, adhesives, and coatings. However, as compared with the physical properties obtained from solvent-based polyurethane resins, the physical properties of coating films obtained from emulsions were considerably inferior in terms of solvent resistance, water resistance and the like. Particularly, in the case of a polyurethane emulsion using polyester diol, in addition to the hydrolysis resistance of the formed film being poor, a problem that the molecular weight is lowered 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 it is applied to artificial leather, sufficient abrasion resistance cannot be obtained. In order to improve these properties, it has been common practice to use a self-crosslinking latex. For example,
Carboxylated latex and melamine-formaldehyde resin or urea-formaldehyde resin, carboxylated latex and aziridine compound (JP-A-55-1
No. 64244), a combination of a latex having a functional group having reactivity with isocyanate such as a hydroxyl group introduced therein 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 in the atmosphere, which is not preferable in the working environment and a small amount of formalin is produced from the final product. Since it is released, its effect cannot be ignored depending on the application. Further, the aziridine compound is problematic because of its toxicity, which limits its intended use or method of use. 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.

Recently, an oxazoline compound has been introduced as a new cross-linking agent for solving these problems, which is low in toxicity and cross-links at a relatively low temperature (Japanese Examined Patent Publication 6).
3-48884, JP-A-2-99537). However, even in the curing system, the latex needs to have a functional group reactive with oxazoline. At that time, if the introduced amount of the functional group is small, the curing does not proceed sufficiently, and if it is too large, the alkali swelling is caused, The problem that the alkali resistance, and eventually the water resistance, was reduced remained.

[0006]

Therefore, it is a self-curing latex, which is capable of retaining water resistance and alkali resistance even when a functional group such as a carboxyl group is introduced, and in combination with a low-toxic curing agent. A coating agent composition is desired in which a cured film has excellent mechanical strength, wear 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 put to practical use in order to solve the above-mentioned problems.
As a result of diligent research on a coating composition for a polyurethane emulsion which is excellent in water resistance, durability, abrasion resistance and solvent resistance and gives a coating film with high surface hardness, a carboxylated polyurethane emulsion using an amorphous polycarbonate diol The present invention has been completed by discovering that the problem can be solved by combining the compound with an oxazoline compound.

That is, the present invention relates to a compound having an organic diisocyanate, an amorphous polycarbonate diol and a group having one hydrophilic center and at least two isocyanate-reactive groups, and if necessary, at least 3
Polyurethane emulsion (A) characterized by comprising a reaction product of a urethane prepolymer composed of a compound having reactivity with one isocyanate and a chain extender,
General formula (1)

[0009]

[Chemical 3]

(In the formula, R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen, halogen, alkyl, phenyl or a substituted phenyl group, and R ₅ is an unsubstituted group having an addition-polymerizable unsaturated bond. Which is an organic group) and is polymerized with an addition-polymerizable oxazoline (a) and optionally a monomer (b) which does not react with one or more oxazoline groups but is copolymerizable with (a). It relates to a coating agent composition comprising the polymer (B).

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. Of these, aliphatic polycarbonate diols are preferable, and more preferably,
The repeating unit is composed of the following general formulas A, B and C, and the ratio of A and B is 9: 1 to 1: 9, and the total amount of A, B and C is the sum of one or more of C Is 0 to 10% (however, the percentage and the ratio indicate the number of repeating units).

[0012]

[Chemical 4] (M and n are integers of 4 to 6 and m ≠ n, R ′ and R ″ are alkylene having 2 to 6 carbon atoms)

Examples of the organic diisocyanate used in the present invention include 2,4-tolylene diisocyanate,
2,6-Tolylene diisocyanate and mixtures thereof (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
Aromatic diisocyanates such as I, xylylene diisocyanate (XDI), and phenylene diisocyanates, and 4,4'-methylenebiscyclohexyl diisocyanate (hydrogenated MD
I), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), cyclohexane diisocyanate (hydrogenated XDI) and the like. A compound having one hydrophilic center and at least two isocyanate-reactive groups has the general formula

[0014]

[Chemical 5]

A diol represented by the formula (wherein R is an alkyl group having 1 to 3 carbon atoms), for example, 2,2-dimethylolpropionic acid, 2,2-dimethylolbutyric acid and 2,2-dimethylol. Examples include valeric acid. Further, diaminocarboxylic acids such as lysine, cystine and 3,5-diaminocarboxylic acid can be mentioned. When these are actually used, amines such as trimethylamine, triethylamine, tri-n-propylamine, tributylamine and triethanolamine, sodium hydroxide, potassium hydroxide, ammonia and the like can be mentioned.

As a matter of course, suitable surfactants are representative, for example, higher fatty acids, resin acids, acidic fatty alcohols, sulfuric acid esters, higher alkyl sulfonates, alkylaryl sulfonates, sulfonated castor oil, sulfosuccinic acid esters and the like. The emulsification stability may be maintained by using together an anionic surfactant or a nonionic surfactant represented by a known reaction product of ethylene oxide with a long chain fatty alcohol or phenol. Examples of the compound having at least three isocyanate-reactive groups used in the present invention include trimethylolethane, trimethylolpropane, sorbitan, glycerin, pentaerythritol, sorbitol and triamine.

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

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

Next, if necessary, the obtained prepolymer is neutralized, then emulsified and dispersed in water, and made into a high molecular weight by a chain extender. When the prepolymer reaction is carried out using a solvent, it is necessary to remove it by a method such as vacuum distillation after the chain extension reaction is completed. The addition-polymerizable oxazoline (a) used in the present invention is represented by the following general formula (1),

[0020]

[Chemical 6]

(In the formula, R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen, halogen, alkyl, phenyl or a substituted phenyl group, and R ₅ is an unsubstituted group having an addition-polymerizable unsaturated bond. It is an organic group.) As a specific example, 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
Mention may be made of -isopropenyl-5-ethyl-2-oxazoline.

Also, one kind or a mixture of two or more kinds selected from these groups can be used. Among them, 2-isopropenyl-2-oxazoline is industrially easily available and preferable. The amount of the addition-polymerizable oxazoline (a) used is not particularly limited, but it is 5% by weight in the polymer (B).
The above is preferable. If the amount is less than 5% by weight, the degree of curing is insufficient and durability, water resistance, etc. tend to be impaired.

In the present invention, the blending ratio of the polyurethane emulsion (A) and the polymer (B) is not particularly limited, but the polymer is added to 100 parts by weight of the solid content of the polyurethane emulsion (A). Resin content of (B) 1
The range of ˜50 parts by weight is preferred. If the amount is less than 1 part by weight, the degree of curing will be insufficient, durability and water resistance will be impaired, and if it is more than 50 parts by weight, the adhesion to the substrate will tend to be impaired.

When the present coating composition is put to practical use, extenders or fillers such as clay, talc, calcium carbonate and mica, white pigments such as titanium white, dyes, polyvinyl alcohol, methyl cellulose,
Thickeners such as carboxymethyl cellulose, starch and dextrin, dispersants, emulsifiers, wetting agents, antifoaming agents such as silicone oil, antifreezing agents such as ethylene glycol, N-methylpyrrolidone, triethylene glycol-di- (2- Various additives such as film-forming aids 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 in detail below with reference to examples, but the present invention is not limited to these examples. In addition, the part in an Example means a weight part.

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 of 1,5-pentanediol (4.0 mol)
And 472 parts (4.0 mol) of 1,6-hexanediol were added, and 1.84 parts (0.08 mol) of metallic sodium was added with stirring at 70 to 80 ° C. After the sodium had completely reacted, 472 parts (8.0) of diethyl carbonate were introduced. When the reaction temperature was raised to 95 to 100 ° C, ethanol began to distill. The temperature was gradually raised to 160 ° C. in about 6 hours.

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

Synthesis Example of Amorphous Polycarbonate Diol
(2) Synthetic 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 number average molecular weight of the C4,6-PCDL was 2000.

Synthesis Example of Amorphous Polycarbonate Diol
(3) Synthetic Example (1) using 360 parts (4.0 mol) of 1,4-butanediol instead of 1,6-pentanediol.
In the same manner as above, an amorphous polycarbonate diol (hereinafter abbreviated as C4,5-PCDL) was obtained. The C4,5-PCDL
Had a number average molecular weight of 2000.

Production Example of Polyurethane Emulsion (1 ) 500 parts of the above C5,6-PCDL (molecular weight 2000),
126 parts of hexamethylene diisocyanate (HDI),
58.5 parts of dimethylolpropionic acid whose carboxyl group is neutralized with triethylamine, methyl ethyl ketone (M
1647 parts of EK) was placed in a reactor equipped with a reflux condenser, a thermometer and a stirring device, and a urethanization reaction was carried out 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 whose temperature was set at 30 ° C. with 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 reacted for 1 hour to increase the molecular weight. 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) Polycarbonate diol having the composition as shown in Table 1 is used as C4,6-PCDL or C4,5-PCDL, C.
6-PCDL (Toagosei Co., Ltd. Carbodiol D-
2000), polyether polyol (PTMG manufactured by Asahi Kasei Kogyo Co., Ltd.), and polyester polyol (Polylite ODX-668 manufactured by Dainippon Ink and Chemicals, Inc.), except that the production method (1) for the polyurethane emulsion was used to prepare a solid. 30% polyurethane emulsions (2), (3), (4), (5) and (6) were obtained.

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

Production Example of Polyurethane Emulsion (1
0) A polyurethane emulsion (9) having a solid content of 30% was obtained in the same manner as in Production Example (9) of polyurethane emulsion except that a part of the diol was replaced with trimethylolpropane.

Example 1 A coating agent (1) prepared according to the formulation shown in Table 2 was
30g with a knife coater on plain weave cloth with 46 wefts / 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. The results are shown in Table 3. The evaluation method in this example is as follows.

1. Treatment conditions Wet heat treatment: 10 at 95 ° C and 95% RH
Treat the coated fabric for 00 hours. 2. Tensile strength (kgf / in) Measured by the labeled strip method based on JIS-L-1036. The value of the wet heat treated product is indicated by the retention rate of tensile strength with respect to the untreated value.

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

5. Tackability Two pieces of sample with width 50mm and length 50mm are piled up on each other, sandwiched between glass plates from both sides, and put a load of 3kg on the upper side, leave it in an oven at 70 ° C for 24 hours, and then remove it. Two sample pieces are peeled off at room temperature, and the tackiness is judged according to the following criteria. ○ No tack at all △ Adhesive and scratches on the surface × Both sides stick together and do not separate

6. Texture Hand-rub the coated cloth and judge according to the following criteria. ◎ Very flexible ○ Flexible △ Slightly stiff and stiff × Stiff and stiff

Examples 2 to 4 Coating agents 2 to 4 were prepared according to the formulations shown in Table 2,
Various physical properties were measured in the same manner as in Example 1. The results are shown in Table 3.

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. The results are shown in Table 3.

Example 5 As shown in Table 4, polyurethane emulsion (7) 1
Oxazoline crosslinking agent (K manufactured by Nippon Shokubai Co., Ltd.)
-1030E solids 40%) was added in 3 parts,
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. Pencil hardness is measured according to JIS-K-5400.

2. Adhesiveness A soft vinyl chloride sheet is coated with the polyurethane emulsion formulation and dried at 140 ° C for 2 minutes to obtain a coating film having a thickness of about 30μ. Adhesiveness was measured according to the cross-cut love method of JIS-K-5400, Display with.

3. Abrasion resistance A polyurethane emulsion composition was applied onto a glass plate and dried at 140 ° C for 2 minutes to obtain a coating film having a film thickness of about 30µ. A taper abrasion tester was used to measure the weight loss after 700 rotations with a load of 500 g and an abrasion wheel CS-17.

4. The water resistant polyurethane emulsion formulation was applied to a vinyl chloride sheet, dried at 140 ° C. for 2 minutes, and then immersed in room temperature water for 24 hours to visually determine the degree of whitening and deterioration of the film.

5. Resistance to NaOH After the vinyl chloride sheet coated with the polyurethane compound was left at room temperature for 24 hours in a 5% NaOH aqueous solution, the state of the film was visually determined. The physical properties obtained are shown in Table 4.

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

Comparative Examples 4 to 6 Samples coated with the polyurethane emulsion formulation obtained in the same manner as in Example 5 according to the formulation shown in Table 4 were prepared, and various physical properties were the same as in Example 5. It was measured. The results are shown in Table 4.

[0050]

EFFECTS OF THE INVENTION It is clear that the coating composition of the present invention provides a coating film having excellent mechanical strength, hydrolysis resistance, NaOH resistance and abrasion resistance, and high surface hardness.

[0051]

[Table 1]

[0052]

[Table 2]

[0053]

[Table 3]

[0054]

[Table 4]

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[Procedure amendment]

[Submission date] March 5, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0053

[Correction method] Change

[Correction content]

[0053]

[Table 3]

Claims (2)

[Claims] 1. An organic diisocyanate, an amorphous polycarbonate diol, a compound having one hydrophilic center and at least two isocyanate-reactive groups, and optionally at least three isocyanate-reactive groups. A polyurethane emulsion (A) comprising a reaction product of a urethane prepolymer containing the compound and a chain extender, and the following general formula (1): (In the formula, R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen, halogen, alkyl, phenyl or a substituted phenyl group, and R ₅ is an unsubstituted organic group having an addition-polymerizable unsaturated bond. A polymer obtained by polymerizing an addition-polymerizable oxazoline (a) represented by the formula (1) and optionally a monomer (b) which does not react with one or more oxazoline groups but is copolymerizable with (a). A coating agent composition comprising (B). 2. An amorphous polycarbonate diol has the following general formulas A, B and C: (M and n are integers of 4 to 6 and m ≠ n, R ′ and R ″ are alkylene having 2 to 6 carbon atoms), and the ratio of A and B is 9: 1 to 1 : 9, the total of one, two or more of C is 0 to 10 with respect to the total amount of A, B and C.
2. The coating agent composition according to claim 1, wherein the coating composition is an aliphatic polycarbonate diol, wherein the percentage and the ratio indicate the number of repeating units.