JPS62212455A - Emulsion resin composition and production thereof - Google Patents

Abstract

PURPOSE:To produce the titled compsn. which has excellent film-forming properties, gives a coating film having excellent adhesion and resistance to wear and water and is stable at a high concn., by polymerizing a radical- polymerizable monomer in the presence of an aq. soln. of a urethane resin. CONSTITUTION:A prepolymer obtd. by subjecting a diisocyanate (e.g., 2,4-tolylene diisocyanate), a glycol (e.g., ethylene glycol) and a glycol having a carboxyl group (e.g., 2,2-dimethylolpropionic acid) to a urethane-forming reaction, is neutralized and the molecular chain thereof is then lengthened. Water is added thereto to obtain an aq. soln. of a urethane resin having an acid value of 20-150. 99-5wt% radical-polymerizable monomer (e.g., an acrylic ester) is emulsion-polymerized in the presence of 1-95wt% (on a solid basis) said aq. soln. of the urethane resin and a radical polymn. initiator at 40-80 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an emulsion resin composition and a method for producing the same. The emulsion resin composition of the present invention has a wide range of uses such as paints and adhesives, and provides coating films with excellent abrasion resistance and adhesion.

(Prior Art) Until recently, most resin compositions were based on organic solvents, and the negative environmental effects of the solvents during coating or drying have become a problem.

In contrast, compositions containing no or only small amounts of solvents, such as water-soluble or water-dispersed resins, are attracting attention. Among them, there are water dispersions of acrylic resin and urethane resin.

Acrylic resins are characterized by good adhesion to substrates, excellent weather resistance, high gloss, and good compatibility with other additives.

On the other hand, its disadvantage is that it is too thermoplastic and tends to cause blocking.

Although urethane resins have good coating film performance such as abrasion resistance and tensile strength, they have drawbacks such as weather resistance and alkali resistance. In addition, it is considerably more expensive than acrylic resin.

In addition, in order to take advantage of the characteristics of both types, it has been practiced to physically mix them together, but in this case, depending on the resin composition, the compatibility between acrylic resin and urethane resin may be poor, resulting in poor storage stability of the compound. This is not good, and in terms of performance, it tends to cancel out the characteristics of both.

Furthermore, water dispersions in which urethane and acrylate are grafted have also been proposed (for example, Patent Publication No. 61-2720
No.], in this case, the manufacturing method of monoacrylated urethane prepolymer is complicated, and the step of grafting it with acrylate lacks stability, making it difficult to obtain a dispersion of fine particles. Furthermore, since a surfactant is used for stabilization, it may have an adverse effect on water resistance.

[Problem that the invention seeks to solve]

The present invention overcomes the drawbacks of the above-mentioned prior art and when used, provides a coating film with excellent abrasion resistance, adhesion, and water resistance, and has excellent film-forming properties. The objective is to provide an emulsion resin composition that is stable even when the oxidation rate is high.

(Means for Solving the Problem) The present inventor has developed an emulsion resin composition that is a combination of an aqueous urethane resin and an acrylic resin by radical polymerization in an aqueous urethane resin liquid, rather than simply mixing the resin components. The inventors have discovered that the above-mentioned problems can be solved by polymerizing and preparing available monomers, and have arrived at the present invention.

That is, in the present invention, in the presence of an aqueous solution of urethane resin corresponding to 1 to 95% by weight of the total resin components, 99 to 5% of the total resin components are
At least 1% by weight of the radically polymerizable monomer
The present invention provides an emulsion resin composition formed by polymerizing at least one species, and a manufacturing method.

To explain the present invention in more detail, the amount of the urethane resin is 1 to 95% by weight, and the amount of the radically polymerizable monomer is 99 to 5% by weight based on the total resin components after polymerization.
It is. If the amount of urethane resin is less than 1% by weight or the amount of radically polymerizable monomer exceeds 999% by weight, a stable emulsion resin composition cannot be obtained. If the amount of urethane resin exceeds 95% by weight or if the amount of radically polymerizable monomer is less than 5% by weight, the gloss, adhesion, and light resistance characteristic of acrylic resins cannot be obtained.

As the urethane resin, a water-based urethane resin is preferable. The water-based urethane resin is manufactured, for example, as follows. That is, first, a diisocyanate, a glycol, and a glycol having a carboxylic acid group are reacted to form a urethane, and a prepolymer is prepared.

Diisocyanates used at this time include aliphatic and cycloaliphatic or aromatic diisocyanates, examples of which include 2,4-tolylene diisocyanate,
2.6-tolylene diisocyanate, 4.4'-diphenylmethane diisocyanate.

m-phenylene diisocyanate, xylylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate ester, 1,4-cyclohexylene diisocyanate, 4
, 4'-dicyclohexylmethane diisocyanate, 5
．． 5'-dimethyl-4,4'-biphenylene diisocyanate 1-15.5'-dimethoxy-4,4'-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, isophorone diisocyanate, etc. Can be mentioned.

Glycols include ethylene glycol, diethylene glycol, and triethylene glycol.

1. Low molecular weight glycols such as 2-propylene glycol, trimethylene glycol, 1,3-butylene glycol, tetramethylene glycol, hexamethylene glycol, hydrogenated bisphenol A, ethylene oxide or propylene oxide adducts of bisphenol A, or polyols. some polyethylene glycol,
Examples include polyethers such as polypropylene glycol, polyesters that are condensates of ethylene glycol and adipic acid, hexanediol and adipic acid, ethylene glycol and phthalic acid, and polycaprolactone.

'Glycols having a carboxylic acid group include 2,2-dimethylolpropionic acid, 2,2-dimethylolbutyric acid,
Examples include 2.,2-dimethylolvaleric acid.

The reaction is dioxane, acetone, methyl ethyl ketone, N
- Organic solvents such as methylpyrrolidone and tetrahydrofuran that are inert to incyanate groups and have a high affinity for water can be used.

Then, the prepolymer is neutralized and chain-extended, and distilled water is added to obtain a water-urethane resin. As a chain extender,
Polyols such as ethylene glycol and propylene glycol, ethylene diamine, propylene diamine, hexamethylene diamine, tolylene diamine, xylylene diamine, diphenyl diamine, diaminodiphenylmethane, diaminocyclohexylmethane, piperazine, 2
-Aliphatic, cycloaliphatic and aromatic diamines such as methylpiperazine, inphorondiamine, and water.

As a neutralizing agent, trimethylamine, triethylamine,
Examples include amines such as tri-n-propylamine, tributylamine, and triethanolamine, sodium hydroxide, potassium hydroxide, and ammonia.

The acid value in water-based urethane resin is 20 to 1 per resin solid content.
50 is preferred. If the acid value is less than 20, the polymerization stability will be poor when the next emulsion resin is polymerized, and aggregates will occur. On the other hand, if the acid value exceeds 150, it will adversely affect the physical properties of the emulsion resin, such as its water resistance.

Examples of radically polymerizable monomers include acrylic esters (acrylic esters such as methyl, ethyl, propyl, butyl, 1-butyl, t-butyl, cyclohexyl, 2-ethylhexyl, lauryl, dodecyl, and stearyl);
Methacrylic acid esters (methyl, ethyl, propyl, butyl, 1-butyl, t-butyl, cyclohexyl, 2-
(methacrylic acid esters such as ethylhexyl, lauryl, dodecyl, and stearyl), hydroxyl group-containing vinyl monomers such as 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate, and aromatic unsaturation such as styrene, α-methylstyrene, and vinyltoluene. Hydrocarbons, acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, monoesters of unsaturated dicarboxylic acids such as monomethyl itaconate and monohydric alcohols, unsaturated dicarboxylic acids such as dimethyl itaconate acid and 1
Diesters with alcohols, vinyl esters such as vinyl benzoate and vinyl acetate, acrylonitrile,
Examples include nitrogen-containing vinyl salts such as methacrylonitrile, acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, vinyl chloride, vinyl fluoride, and vinylidene chloride.

As the radical polymerization initiator, not only water-soluble initiators used in ordinary emulsion polymerization but also oil-soluble initiators can be used. Examples include potassium persulfate, ammonium persulfate, azobiscyanovaleric acid, t-butyl hydroperoxide, and abbisisobutyronitrile. In addition, these radical generators and sulfites,
So-called redox catalysts made in combination with sulfoxylates can be used.

The amount of the radical polymerization initiator used is suitably 0.1% to 5% by weight based on the total amount of radically polymerizable monomers. More preferably, it is 0.2% to 5%.

The radical polymerization initiator can be added by a conventional method. For example, it can be added all at once or continuously or in parts.

The radically polymerizable monomer or radically polymerizable monomer mixture can be added all at once, continuously, or in portions, but when considering the control of polymerization heat or polymerization stability,
Continuous dropping is preferred.

Furthermore, chain transfer agents such as mercaptans can be added if necessary.

Although the reaction temperature varies depending on the type of monomer used, the type of polymerization initiator, etc., a temperature range of 40°C to 80°C is usually suitable. If the temperature is below 40°C, the polymerization rate will be slow;
When the temperature exceeds 0°C, more resin adheres to the inner wall of the pot.

According to the production method of the present invention, a stable and fine-particle emulsion resin composition can be produced without using any surfactant that is normally used in emulsion polymerization, and it has excellent mechanical stability and storage stability. It also has good compatibility with other additives when formulating paints. Of course, a surfactant may be used if necessary.

The obtained emulsion resin composition can provide a coating film with excellent abrasion resistance, adhesion, water resistance, and gloss, and can be made by appropriately selecting the ingredients, amounts, and combinations of radically polymerizable monomers. It can be applied to paints, adhesives, fiber processing agents, paper coating agents, architectural paints, etc.

(Example) Hereinafter, the present invention will be explained in more detail using reference examples, examples, formulation examples, and comparative examples.

Reference example [Production of water-based polyurethane resin] (1) Polypropylene glycol (molecular weight 1000
), dicyclohexylmethane diisocyanate 176JI, dimethylolpropionic acid 7oII and N-methylpyrrolidone 196I were placed in a reactor equipped with a reflux condenser, a thermometer and a stirring device.

A prepolymer was prepared by carrying out a urethanization reaction while maintaining the temperature at 80 to 100°C. Next, triethylamine 48II was added to this prepolymer to neutralize it, then hexamethylene diamine s, oII was added, and while adding distilled water, the temperature inside the reactor was maintained at 35 ° C. or less to carry out a polymerization reaction. By the end of the reaction, 456.9 g of distilled water was added to obtain water-based polyurethane resin C shown in Table 1. The acid value per resin solid content of this aqueous polyurethane resin was 98.

(2) Water-based polyurethane resins A, B, and D were prepared in the same manner as in (1) using the raw materials shown in Table 1.

Example 1 A reaction vessel equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen inlet tube was charged with 471.9 g of deionized water and the aqueous polyurethane resin A1331iF obtained in Reference Example, and heated to 60°C while stirring. , styrene 2571 and 2 at 60'C
- Ethylhexyl acrylate 1239 was added dropwise over 5 hours. Simultaneously with the dropwise addition of the above-mentioned hexamer mixture, a 1°-aqueous dispersion of t-butyl hydride peroxide 18II and a 10% aqueous solution of sodium formaldehyde sulfoxylate 1819', which had been prepared in advance, were also added dropwise. After the dropwise addition, the reaction solution was heated to 70'C.
The polymerization reaction was completed by maintaining the temperature for 1 hour. The obtained emulsion polymer has a nonvolatile content of 7%, 4α3%, and a viscosity of 2550 cps%p.
It was an aqueous emulsion resin composition with H7.4 and particle diameters o and oaoμ.

Examples 2 to 9 and Comparative Examples 2 and 4 The water-based emulsion resins in Table 2 (
Aqueous emulsion silane resin compositions of Examples 2 to 9 and Comparative Example 2.4) were prepared.

Comparative Examples 1 and 3 Deionized water 45611 was placed in a reaction vessel equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen inlet tube and heated to 700C, and 1 g of sodium lauryl sulfate and 2 I of potassium persulfate were added thereto.

A mixture of 252 g of nystyrene, 140 g of 2-ethylhexyl acrylate, 8 g of methacrylic acid, and 0.1' of t-dodecyl mercaptan was added to 159.611 g of deionized water containing 1 g of sodium lauryl sulfate and emulsified to form a seven-mer emulsion. was prepared and added dropwise over 5 hours to deionized water prepared in the reaction vessel. After dropping, the mixture was kept at 70°C for 2 hours to complete the polymerization reaction.
The pH was adjusted to about 7 with ammour water to obtain an acrylic emulsion resin of Comparative Example 1. In the same manner, an acrylic emulsion resin of Comparative Example 3 was obtained using the raw material parts shown in Table 2.

As shown in Table 2, stable fine particle emulsion resin compositions (Examples 1 to 9) were obtained by the production method of the present invention. Furthermore, when the amount of water-based urethane resin used was small (Comparative Example 2), stability during polymerization was poor, and generation of coarse particles was observed.

Formulation example 1 [Rust prevention paint formulation] 10 parts of ethanol, 5 parts of butyl cellosolve, 1 part of jetanolamine, and 5 parts of carbon black HP-510B were added to 100 parts of the aqueous emulsion resin composition obtained in Example 1 to form a rust prevention paint. A paint was prepared and used for the following test measurements.

Formulation Examples 2 to 10 The aqueous emulsion compositions obtained in Examples 2 to 4 and 9 and Comparative Example 1.4, the aqueous polyurethane resin obtained in Reference Example, and the raw materials shown in Table 3 were blended in the parts shown in Table 3. , Formulation example 1
A rust preventive paint was prepared in the same manner as in Example 1, and subjected to the same test as in Formulation Example 1.

〔Test method〕

Formulation Examples 1 to 10 were applied to a polished mild steel plate measuring 150 parts m x 70 m using a bar coater (A60). 25℃, 65SR
It was left to dry for 72 hours in a constant temperature and humidity chamber of H, and was subjected to the test shown below.

(1) Gloss 60 parts specular reflection gloss was measured using a gloss meter (Nippon Denshoku Kogyo "N").
Measured with D-101D").

(2) Cross-cutting (JI8 K-5400) The coating surface is cross-cut at intervals of 1 m1, cellophane tape is adhered to it, and it is peeled off at a 90° angle. The percentage of squares that do not peel off. (10n/100 is the best and 0/100 is the worst).

(5) Water resistance After immersing the sample in distilled water at 25° C. for 24 hours, it was taken out and the whitening state of the coating film was observed with the naked eye.

(4) Tsuruto Sprayability A test piece cut to the base was subjected to a salt spray test (JISZ-2371) using 50% salt water for 72 hours, and then the rust state of the coating film was observed.

○－－－－－Good Δ−−−−−−Slightly poor X --- Good The measurement results are shown in Table 3.

As shown in Table 3, as a result of testing gloss, adhesion, water resistance, and smooth sprayability, it was found that when using the emulsion resin composition of the present invention (formulation examples 1 to 4), the physical properties of water-based urethane resin and acrylic emulsion resin Blend (Blend Examples 6 to 9)
Compared to sea urchin, the gloss and adhesion were good, and the smooth sprayability was particularly excellent. When a water-based urethane resin with a high acid value was used (Formulation Example 5), the water resistance and salt spray properties were slightly inferior. Moreover, when the amount of aqueous urethane resin exceeded 95 inches (formulation example 10), gloss and adhesion were poor.

Formulation Examples 11 to 18 [Abrasion-resistant paint formulation] Deionized water, ethyl calpitol, and tributoxyethyl phosphatide were added to the aqueous emulsion resin compositions obtained in Examples 5 to 8 and Comparative Example 2.3 in the parts shown in Table 4. Fate, 40%
A formulation containing polyethylene wax, 40% alkali soluble resin and fluorosurfactant was prepared and subjected to an abrasion resistance test.

[Test method]

Formulation Examples 11 to 18 were applied to a 150in x 70cm Bonderite treated steel plate 4P144 using a bar coater (/%60), and left in a constant temperature and humidity room at a temperature of 25°C and a humidity of 65% RH for 72 hours to dry. , and was subjected to an abrasion resistance test.

The abrasion resistance test was carried out using a taper abrasion tester manufactured by Toyo Seiki, using a C8-17 abrasion ring, and applying a load of 1. The measurement results are shown in Table 4.

As shown in Table 4, as a result of the abrasion resistance test, if the emulsion silane resin composition of the present invention is used (formulation examples 11 to 14),
Superior abrasion resistance results were obtained compared to physical blends of aqueous urethane resin and acrylic emulsion (formulations 16 to 18). Furthermore, when the amount of aqueous urethane used was less than 1% (Formulation Example 15), sufficient wear resistance was not obtained.

(Effects of the Invention) As described above, by the production method of the present invention, a stable fine particle emulsion resin composition was obtained without using a surfactant. Its characteristics include excellent adhesion to substrates and abrasion resistance, and since it does not use any surfactants, it has excellent water resistance and salt water resistance, and is used as a paint, adhesive, and fiber processing agent. It can be applied to paper coating agents, architectural paints, etc.

Claims (2)

[Claims] (1) Polymerizing at least one radically polymerizable monomer corresponding to 99 to 5% by weight of the total resin components in the presence of an aqueous solution of urethane resin corresponding to 1 to 95% by weight of the total resin components. An emulsion resin composition consisting of (2) Polymerizing at least one radically polymerizable monomer corresponding to 99 to 5% by weight of the total resin components in the presence of an aqueous urethane resin liquid corresponding to 1 to 95% by weight of the total resin components. A method for producing an emulsion resin composition, characterized in that: