JP3090527B2 - Aqueous composition of (meth) acrylate group-containing compound - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to heating or radiation,
For example, the present invention relates to an aqueous resin composition which is polymerized and cured by irradiation with ultraviolet rays, electron beams, microwaves, or the like.

[0002]

2. Description of the Related Art Resins used for paints and inks are usually of an organic solvent dilution type in which a resin obtained by vinyl polymerization or polycondensation is dissolved in an organic solvent, and water obtained by emulsion polymerization in water is used as a solvent. Emulsion type. These form a film by physical means of heating and drying, and are the simplest and have been awarded. However, these resins are classified as thermoplastic resins, and when heated to a temperature higher than the glass transition temperature of the resin, the physical properties are sharply reduced, and the lack of heat resistance is undesirable. Have been. As a solution in terms of resin physical properties, crosslinking by heating with methylol melamine or the like, that is, conversion to a thermosetting resin is a commonly employed means.

On the other hand, as an attempt to solve the above, radicals are generated by heating a compound having a (meth) acrylate group, particularly a compound having two or more (meth) acrylate groups in one molecule. A (meth) acrylic ester is polymerized and crosslinked in the presence of a so-called alkyd resin type or a photopolymerization initiator which generates radicals upon irradiation with radiation by blending a so-called thermal polymerization initiator to form a heat-polymerizable resin. There are radiation curable resins. In any case, the coating viscosity in actual use is limited, and it is difficult to reduce the viscosity as it is. That is, when thinner coating is required or when spray coating is performed, the film must be diluted with an organic solvent before use. However, in recent years, as the problem of air pollution caused by an organic solvent has been raised, the need for a technique for reducing the viscosity of a (meth) acrylate compound without using an organic solvent has been increasing. Therefore, an emulsion type having no problem in viscosity has been developed, but there are problems in stability of the emulsion, water resistance of the cured product, and bending property of the cured film, and at present it has not yet been put to practical use.

[0004]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention has good storage stability when a compound having a (meth) acrylate group is dispersed, emulsified or solubilized in water. The object of the present invention is to provide a composition having excellent water resistance of the cured product and good bending property of the cured film.

[0005]

Means for Solving the Problems In proceeding with the study, the present inventors have recognized that it is important to select a surfactant in order to disperse a compound containing a (meth) acrylate group in water. We proceeded with the study. As a result, although a general low molecular weight surfactant has good dispersion stability at the time of production, it has a disadvantage that long-term stability and water resistance of a cured product are deteriorated. The resin obtained by polymerizing the (meth) acrylate group by dispersing, emulsifying or solubilizing the (meth) acrylate compound and the acrylic resin in water is not only heat-resistant and surface-hardness, but also water-resistant and Paying attention to the fact that the bending property of the cured film is also improved, the present invention has been completed. That is, it is an aqueous composition of a (meth) acrylate group-containing compound containing the following a, b, and c. a. (Meth) acrylate group-containing compound (hereinafter a
Component) b. Acrylic resin (hereinafter referred to as component b) c. N ₁ mol of a structural unit represented by the following formula (I),

[0006]

Embedded image N ₂ mol of a structural unit represented by the following formula (II), and

[0007]

Embedded image N ₃ mol of a structural unit represented by the following formula (III)

[0008]

Embedded image One end of a linearly irregularly arranged compound consisting of the following formula (IV)

[0009]

Embedded image (Hereinafter, referred to as component c).

The component (a) used in the present invention includes (a)
Urethane (meth) acrylate, (b) epoxy (meth) acrylate, (c) polyol (meth) acrylate, (d) polyether (meth) acrylate,
(E) polyester (meth) acrylate,
One or more of these may be used in combination.

(A) is a compound containing a urethane group in its structure, which can be synthesized by reacting a polyisocyanate with a polyalcohol and an alcohol having a (meth) acryl group. Examples of the polyisocyanate include tolylene diisocyanate, naphthalene diisocyanate, xylylene diisocyanate, paraphenylene diisocyanate, tetramethyl xylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, and the isocyanurate ring which is a trimer of the above diisocyanate. And the like.

Examples of the polyalcohol include hydrocarbon diols such as 1,4-butanediol and 1,6-hexanediol, alicyclic diols such as cyclohexanedimethanol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol and the like. Alkylene oxide derivatives such as polyalkylene glycols, alkylene oxide adducts of hydrocarbon polyols, and alkylene oxide adducts of aromatic polyphenols; polycondensation terminal polyols of hydrocarbon polyols with succinic acid, adipic acid, terephthalic acid, or the like; or There are hydrocarbon polyols and compounds called polyester polyols obtained by ring-opening addition of aromatic polyphenols with lactone compounds such as caprolactone and γ-valerolactone. As the alcohol having a (meth) acrylic group,
Examples include hydroxyethyl acrylate, hydroxypropyl acrylate, ring-opening reactants of caprolactone and acrylic acid, hydroxyethyl methacrylate, hydroxypropyl methacrylate, and ring-opening reactants of caprolactone and methacrylic acid.

(B) is a reaction product of an epoxy compound and a (meth) acrylic group-containing terminal carboxylic acid or alcohol compound. As the epoxy compound, butyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether, nonylphenyl glycidyl ether, monoepoxidized products such as epoxidized α-olefin, neopentyl glycol, diglycidyl ether,
1,6-hexanediol diglycidyl ether, polyalkylene glycol diglycidyl ether, adipic acid diglycidyl ester, phthalic acid diglycidyl ester, dibromoneopentyl glycol diglycidyl ether, bisphenol A diglycidyl ether, tetrabromobisphenol A diglycidyl ether Polyepoxy compounds such as triglycidyl ether of trimethylolpropane, triglycidyl ether of tris (hydroxyethyl) isocyanurate, and triglycidyl ether of glycerin; and polyglycidyl ether of novolak phenol.

As the (meth) acrylic group-containing terminal carboxylic acid or alcohol compound, acrylic acid, methacrylic acid, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxyethyl (meth) acrylate or hydroxypropyl ( Meta)
Examples of the terminal carboxylic acid ester include a (1: 1) ring-opening reaction of acrylate with maleic anhydride, succinic anhydride, and phthalic anhydride.

(C) is a (meth) acrylic acid ester formed by an esterification reaction between a terminal hydroxyl compound and acrylic acid or methacrylic acid. Examples of the terminal hydroxy compound include monools such as 2-ethylhexanol and dodecyl alcohol; diols such as 1,6-hexanediol, 1,9-nonanediol and neopentyl glycol; triols such as trimethylolpropane and glycerin; and pentaerythritol. And tetraols such as ditrimethylolpropane, and hexaols such as sorbitol and dipentaerythritol.

(D) is a (meth) acrylic acid ester formed by an esterification reaction of acrylic acid or methacrylic acid with an adduct of a terminal hydroxy compound and an alkylene oxide in (c). Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, and tetrahydrofuran.

(E) is a (meth) acrylic ester synthesized by an esterification reaction of a polycarboxylic acid with a polyol and acrylic acid or methacrylic acid. As the polycarboxylic acid, a dicarboxylic acid such as succinic acid, adipic acid, azelaic acid, and hetonic acid is mainly used, and a tricarboxylic acid such as trimellitic acid can also be used. The above-mentioned terminal hydroxy compound is used as the polyol.

The component (b) used in the present invention is an acrylic resin, which is acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, stearyl acrylate,
2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, cyclohexyl acrylate, benzyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, methacrylic acid 2
-A copolymer of one or more monomers selected from ethylhexyl, lauryl methacrylate, stearyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, glycidyl methacrylate, benzyl methacrylate and cyclohexyl methacrylate; It is a polymer. Also included are those obtained by copolymerizing monomers selected from vinyl chloride, vinylidene chloride and styrene at a ratio of 20% or less. These polymers can be synthesized by suspension polymerization, emulsion polymerization, bulk polymerization, or solution polymerization.

The component c used in the present invention is a copolymer of four groups of substances (formulas I to IV). The first group is represented by the structural unit of the formula (I), wherein R ₁ is a methyl group or a hydrogen atom, and R ₂ is an alkyl group having 1 to 18 carbon atoms.
Specifically, it is called alkyl acrylate or alkyl methacrylate, and includes methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, stearyl acrylate,
Examples thereof include methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, and stearyl methacrylate.

The second group is represented by the structural unit of the formula (II):
R ₁ is as defined in the formula (I), R ₃ is an alkylene group having 2 to 4 carbon atoms, n4 represents an integer of 1 to 20. Specifically, it is referred to as polyoxyalkylene acrylate or polyoxyalkylene methacrylate, and includes 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, and poly (2-acrylate).
20) oxyethylene hydroxyl, poly (2-20) oxypropylene hydroxyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, poly (2-20) oxyethylene hydroxyl methacrylate , Poly (2-20) oxypropylene hydroxyl methacrylate and the like.

The third group is represented by the structural unit of the formula (III), R ₁ is the same as in the formula (I), and M is Na, K or NH ₄ . These are acrylates and methacrylates, which themselves have solubility in water. Specific examples include sodium acrylate, potassium acrylate, ammonium acrylate, sodium methacrylate, potassium methacrylate, and ammonium methacrylate.

The fourth group is an α-methylstyrene dimer represented by the formula (IV).

Formula (I), (II) and (III) of the component c
Are represented by n ₁ , n ₂ and n ₃ , respectively,
It is an integer of 0. The total number of moles of n ₁ , n ₂ , and n ₃ is 5 or more, and when it is less than 5, water-resistance is poor due to poor emulsifying and dispersing ability in water and poor physical properties of a film after drying alone. Cause lack of. The preferred range of the number of moles is 10 to 50 moles.

The polymer surfactant, which is the component c, is obtained by using the above-mentioned fourth group component as an essential component and one or more (meth) acrylic esters selected from the first to third groups. . Note that each group is not limited to one type, and it is also possible to combine them. In general, the component c is preferably synthesized in an emulsion polymerization system. The (meth) acrylate compounds of the first to third groups are mixed in the presence of water and a small amount of a surfactant, and a thermal polymerization initiator is added. It is obtained by adding, mixing, heating and allowing a predetermined polymerization to proceed, and then adding and blending the fourth group compound to complete the polymerization.

The aqueous composition of the present invention can be produced by any of the following methods, any of which may be used. The component (a) and the component (b) containing no solvent are mixed under heating if necessary, and the component (c) is mixed therein. If necessary, water is gradually added while mixing well under heating and pressurization to emulsify and disperse. The component (a), the component (b) and the component (c) containing a solvent are mixed well, and water is added to emulsify and disperse. The component (a) and the component (c) are mixed, and water is added to make an emulsified and dispersed solubilized product. The emulsion of the component b is mixed and mixed with the mixture. The emulsification and dispersion time and temperature are not particularly limited in the above.

The proportions of the components a, b and c in the aqueous composition of the present invention are not particularly limited and may be appropriately adjusted. The component is 5 to 50 parts by weight, preferably 10 to 40 parts by weight, and the component b is 5 to 50 parts by weight, preferably 10 to 10 parts by weight.
And c is 0.5 to 10 parts by weight, preferably 1 to 5 parts by weight.

In using the aqueous composition of the present invention, various additives can be blended, for example, calcium carbonate, mica, clay, silica gel,
There are inorganic fillers such as alumina, pigments, paints, flame retardants, and dispersants for better dispersing them. Further, there are thermal polymerization initiators such as peroxides and azo compounds for initiating polymerization, and photopolymerization initiators such as benzophenone, benzoin and benzyl ketals.

[0028]

The aqueous composition thus obtained is superior in storage stability to that obtained by using a conventional surfactant, and requires the use of a specific polymer surfactant as the component c. Obtained by Further, a thermal polymerization initiator is added to the aqueous composition, and a (meth) acrylate group is polymerized by heating to form a resin, or a photopolymerization initiator is added and blended, and after water is dried, ultraviolet irradiation or water drying is performed. The resin formed by polymerization by electron beam irradiation, unlike conventional thermoplastic resins, has excellent heat resistance and surface hardness,
And, by blending the b and c components, the water resistance is excellent, and the physical properties of the cured product of the resin, particularly the bending property of the cured film, are greatly improved.
Excellent for heat-curing or radiation-curing paints and inks represented by ultraviolet rays and electron beams.

[0029]

Next, the present invention will be described in more detail with reference to the aqueous composition of the present invention and Examples, but the present invention is not limited to only these Examples. (Component c) Four types of surfactants (c-1 to c-4) in which each structural unit other than the α-methylstyrene dimer structural unit of the formula (IV) is shown in Table 1 were prepared.

[0030]

[Table 1]

(Preparation of Aqueous Composition) Various aqueous compositions (1 to 18) were prepared by the following preparation method and in the composition shown in Table 2.
Was prepared. The component c is mixed with the component a, and water is gradually added with stirring to emulsify and disperse. Next, the emulsified b component is mixed therein.

[0032]

[Table 2]

The components a to c in Table 2 used the compounds described below. * 1: Polyester diol (1 mol) formed by esterification of 1,4-butanediol (4 mol) and adipic acid (3 mol) and tolylene diisocyanate (2
Mol) and 2-hydroxyethyl acrylate (2 mol)
Synthesized by the reaction with * 2: Reaction product of bisphenol A diglycidyl ether (1 mol) and acrylic acid (2 mol). * 3: Bisphenol A (1 mol) and ethylene oxide (1
0 mol) and an esterification reaction product with acrylic acid (2 mol). * 4: An esterification reaction product with terephthalic acid (3 mol), diethylene glycol (2 mol), 1,6-hexanediol (1 mol), and acrylic acid (2 mol). * 5: Polymer obtained by using 2-ethylhexyl methacrylate (60 parts by weight) and methyl acrylate (40 parts by weight) as monomer components, azoisobutyronitrile as a polymerization initiator, and adding 2 parts by weight thereof.

* 6: Lauryl methacrylate (55 parts by weight), n-butyl methacrylate (40 parts by weight), methacrylic acid (5 parts by weight) as monomer components, and azoisobutyronitrile in xylene (100 parts by weight) (2 parts by weight) as a polymerization initiator. * 7: 2-ethylhexyl methacrylate (50 parts by weight), methyl methacrylate (40 parts by weight), 2-hydroxyethyl methacrylate (10 parts by weight) as a monomer component, and poly (n = 5) in water (100 parts by weight). ) An aqueous dispersion polymer obtained by adding and reacting ammonium oxyethylene nonylphenyl ether sulfate (2 parts by weight) and ammonium persulfate (1 part by weight). * 8: Poly (n = 5) oxyethylene nonylphenyl ether ammonium sulfate as an anionic surfactant * 9: Poly (n = 5) oxyethylene nonyl phenyl ether acidic phosphoric acid monoester as an anionic surfactant * 10: Nonionic surfactant (N = 10) oxyethylene monostyrenated phenyl ether as an agent

Examples 1 to 11 and Comparative Examples 1 to 7 (Evaluation 1) The storage stability of the obtained aqueous compositions was evaluated, and the results are shown in Table 3. The storage stability is obtained by storing the aqueous composition at 20 ° C. and visually observing the state after a certain period.

[0036]

[Table 3]

From Table 3, immediately after the production, except for Comparative Example 7, the other comparative products showed milky white liquor, but the stability was poor.

Examples 12 to 22 and Comparative Examples 8 to 14 Samples were prepared by the following methods. [Method for Preparing Sample] (1) In the case of "heating" curing means 0.5 part by weight of benzoyl peroxide was added to 100 parts by weight of the aqueous composition prepared by the compounding method shown in Table 2, and the mixture was stirred and mixed. (2) In the case of curing means “UV” 100 parts by weight of the aqueous composition prepared by the compounding method shown in Table 2 was added to 2-hydroxy-2-methyl-1-phenylpropane-
2 parts by weight of 1-one is added and mixed with stirring. (3) When the curing means is "EB" or "None" The aqueous composition is used as it is.

Next, the samples prepared by the above-described various methods were cured by the following procedure to prepare a cured product. The physical properties of the cured product were evaluated in Evaluation 2 below, and the results are shown in Table 4. [Preparation Method of Cured Product] (1) Application The sample prepared above is applied on a glass plate to a thickness of 100 μm using a bar coater. (2) Preliminary drying (water drying) The glass plate coated with the sample is placed in an oven at 100 ° C for 10 minutes to dry the water. (3) Curing 1) In the case of thermal curing A thermosetting is carried out by placing in an oven at 150 ° C. for 10 minutes. 2) In the case of UV curing A high-pressure mercury lamp F with an irradiation intensity of 80 w / cm is passed at a conveyor speed of 5 m / min. 3) In the case of EB curing The glass plate was accelerated under nitrogen atmosphere at an acceleration energy of 200 Kv.
An electron beam with an irradiation dose of 5 Mrad is irradiated and cured.

(Evaluation 2) (1) Stickiness of Surface The degree of stickiness of the surface of the cured product is judged based on a finger touch. (2) Water resistance 5 ml of pure water is applied to the surface of the cured product, and the lid is covered with a petri dish. After 24 hours, water is wiped off, and the surface of the cured product is observed according to the following criteria. ：: No change in surface state as compared with a portion not in contact with water. Δ: Not whitened but slightly swollen. ×: Whitened. (3) Alcohol resistance Apply 5 ml of ethanol to the surface of the cured product, and cover with a petri dish. After 24 hours, the surface of the cured wipe is observed according to the following criteria. ○: No change △: Surface gloss disappeared ×: Surface melted

(4) Heat resistance The coated glass plate is placed in an oven at 120 ° C. for 10 minutes, and immediately thereafter, the glass plate is scratched with a split brush. When the film was easily scratched and the film was peeled, it was evaluated as x, and when it was not, it was evaluated as ○. (5) Surface specific resistance The coated glass plate is left in a constant temperature room at 20 ° C. and 60% RH for one day, and then the surface specific resistance is measured with a super insulation resistance meter. The larger the value is, the worse the antistatic property is. (6) Bendability Instead of a glass plate, a 0.5 mm-thick coated paper is used, coated, dried and cured. 180 coated paper
Bending and observing the state of cracks on the coating film surface. Those with no cracks were marked with ■, and those with cracks were marked with x.

[0042]

[Table 4]

The aqueous composition of the present invention was easily cured by irradiation with heat or radiation (ultraviolet rays, electron beams), had no stickiness on the surface, and was excellent in water resistance, alcohol resistance and heat resistance. Further, it can be seen that the use of the acrylic resin has excellent bendability. In addition, the antistatic performance is also good.

[0044]

The aqueous composition of the present invention has good storage stability, low viscosity, and after being dried with water, is easily polymerized and cured by heating or irradiation with radiation (ultraviolet rays, electron beams), and the desired resin is obtained. It has been found that it is possible to improve the water resistance and the bendability, and that the antistatic performance is good.

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08F 265/06 C07C 69/54 C08F 2/44 C08F 265/04

Claims (1)

(57) [Claims] 1. (meth) containing the following a, b and c
Aqueous Composition of Acrylate Group-Containing Compound a. (Meth) acrylate group-containing compound b. Acrylic resin c. N ₁ mol of a structural unit represented by the following formula (I): N ₂ mol of a structural unit represented by the following formula (II): N ₃ mol of a structural unit represented by the following formula (III): (Wherein R ₁ is a hydrogen atom or a methyl group, and R ₂ is
An alkyl group of 18, R ₃ is an alkylene group having 2 to 4 carbon atoms, M is Na, K or NH ₄ , n ₁ , n ₂ , n ₃
Is an integer of 0 to 50, n ₁ + n ₂ + n ₃ is an integer of 5 or more, and n ₄ is an integer of 1 to 20. )) Has one end of a linearly irregularly arranged compound having the following formula (IV): A copolymer comprising a compound represented by the formula: