JPH06287260A - Activation energy beam-curable water-containing resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition consisting of a vehicle which is a reaction product of specific compounds and water, having water resistance, solvent resistance and curing properties equivalent to a nonaqueous system, excellent in stability, low viscosity and low irritation to skin and useful for printing ink, etc. CONSTITUTION:The objective composition consists of a vehicle which is a reactional product obtained from (A) an acrylic acid ester having a hydroxyl group in the molecule, (B) an organic polyisocyanate and (C) polyethylene glycols having hydroxyl group and water. In the vehicle, the component C is HO(OCH2 CH2)nOR [R is H or lower alkyl; (n) is 3-25] and a ratio of the component A/the component B used is (25-70)/(30-75) and the component C/these components (A+B) is 0.2-0.6.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an active energy ray-curable water-containing resin composition.

[0002]

2. Description of the Related Art Active energy ray curable resin compositions are
It is generally recognized as being excellent in safety because it does not contain a solvent, and in terms of productivity and energy saving because it has excellent curability. The active energy ray-curable resin composition is, in light of such characteristics, an overcoat agent for various plastic films, a paint for woodworking,
It is used as an active ingredient in various coatings such as printing ink and adhesives.

In the above-mentioned applications, when it is particularly necessary to reduce the viscosity of the product, a convenient method such as using a large amount of a reactive diluent or using an organic solvent together is usually adopted. However, when a large amount of the reactive diluent is used, problems such as skin irritation and deterioration of curability are likely to occur, and when an organic solvent is used in combination, the risk of air pollution and fire increases.

Therefore, in recent years, from the viewpoints of prevention of air pollution, regulation under the Fire Service Law, occupational safety and health, etc., there has been an increasing demand for making the composition aqueous. Various water-based active energy ray-curable resin compositions have already been developed. However, in the skeleton of the vehicle resin used for these, (meta)
Since there are relatively many ester moieties derived from acrylic acid esters, hydrolysis and performance deterioration may occur over time, and gelation may occur during product storage.
At present, it has not been possible to achieve satisfactory characteristics.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances regarding an aqueous active energy ray-curable resin composition.
A water-based active energy ray-curable resin composition having curability and water resistance comparable to those of non-aqueous active energy ray-curable resin compositions, and having relatively low viscosity, low skin irritation and excellent leaving stability. The purpose is to collect things.

[0006]

Means for Solving the Problems In order to solve the above problems, the present inventor has focused on vehicle constituent components in a composition, and as a result of diligent research on the types of constituent components and their use ratios, It was surprisingly found that an excellent water-based active energy ray-curable resin composition satisfying the above purpose can be obtained by selecting the following specific component as a vehicle. The present invention has been completed based on such findings.

That is, the present invention relates to an active energy ray-curable water-containing resin composition containing a vehicle and water as essential components, wherein the vehicle (A) has an acrylic acid ester containing at least one hydroxyl group in the molecule (B). The present invention relates to an active energy ray-curable water-containing resin composition, which is a reaction product of an organic polyisocyanate and (C) a polyethylene glycol having at least one hydroxyl group.

The vehicle in the active energy ray-curable water-containing resin composition of the present invention is a reaction product composed of the components (A), (B) and (C) as described above.
The component (A) is a hydroxyl group-containing acrylate ester, and various compounds having at least one hydroxyl group and at least one (meth) acryloyl group in the molecule are applicable. Specific examples include 2-hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate. , 2-hydroxyalkyl (meth) acrylate, 2-aralkyloxypropyl (meth) acrylates such as 2-phenoxypropyl (meth) acrylate, pentaerythritol triacrylate, etc., and these can be used alone or in combination. The amount of the component (A) used is usually 25 to 70% by weight, preferably 30 to 65% by weight, based on the sum of the components (A) and (B) in the vehicle. When a polyol polyacrylate such as a polyepoxy acrylate is used, the viscosity of the product to be obtained tends to increase, so it is preferable to use it in combination with the acrylates exemplified above.

Component (B), which is an organic polyisocyanate, corresponds to an organic polyisocyanate having three or more reactive isocyanate groups in the molecule. Further, its molecular weight is preferably about 500 to 1000. (B)
Specific examples of the component include, for example, trimer obtained from various diisocyanates such as 1,6-hexane diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, and trimethylol. Examples thereof include a prepolymer reacted with a polyhydric alcohol such as propane, polymethylene polyphenyl polyisocyanate, and the like.
The amount of the component (B) used is usually 30 to 75% by weight, preferably 35 to 70% by weight, based on the sum of the components (A) and (B) in the vehicle.

As the polyethylene glycols as the component (C), various polyethylene glycols having at least one hydroxyl group in the molecule can be used without particular limitation.
Those represented by are particularly preferable.

H- (OCH ₂ CH ₂ ) _n —OR (1) (In the formula, R is a hydrogen atom or a lower alkyl group, and n is 3
Indicates an integer of -25. ) The amount of the component (C) used in the vehicle is usually (C) / {(A) + (B)} = 0.2 to
It is preferable to satisfy the condition of 0.6, preferably 0.25 to 0.4. If the ratio is less than 0.2, the water dispersibility of the water-containing resin composition itself is poor, or even if the initial water dispersibility is relatively good, separation tends to occur over time. Is not preferable. On the other hand, when it exceeds 0.6, the curing becomes insufficient due to a decrease in the crosslink density, or the water resistance of the coating tends to decrease even if it is sufficiently cured, which is not preferable.

The method for producing the vehicle comprising the components (A) to (C) will be described below. First, (A) component and (B)
The components are reacted in the above proportions to obtain a prepolymer having free isocyanate groups. Then, the prepolymer and the component (C) are reacted in the above-mentioned use ratio. The reaction temperature is 40 to 100 ° C., preferably 60 to 80 ° C., and the total reaction time is about 4 to 12 hours. In the above urethanization reaction, it is preferable to use a known urethanization catalyst such as stannous octylate for promoting the reaction. Further, in order to prevent the polymerization of the component (A) during the urethanization reaction, hydroquinone, methoxyphenol,
A polymerization inhibitor such as phenothiazine is added to the reaction system in an amount of 10
~ 5000 ppm, preferably 50-2000 ppm, or air-sealed.

The reaction product obtained above can be easily made into the active energy ray-curable water-containing resin composition of the present invention by dispersing it in water according to various known methods. Specifically, while the reaction product is vigorously stirred, water is gradually added to adjust the solid content to about 20 to 50% by weight. The temperature in the system during dispersion is usually 40 to 100 ° C., preferably 60 to 80 ° C., and after the dispersion is completed, the desired water-containing resin composition can be obtained by cooling. Even in the dispersion step, the above-mentioned operation for preventing the polymerization of the component (A) can be carried out if necessary.

The active energy ray-curable water-containing resin composition of the present invention is as described above, (A), (B) and (C).
It is an oil-in-water emulsion obtained by forcibly emulsifying and dispersing a reaction product consisting of components. The water content in the composition is not particularly limited, but is determined in consideration of workability, viscosity, etc. of the composition to be obtained, and is usually in the range of 60 to 900 parts by weight with respect to 100 parts by weight of the vehicle. The composition does not substantially contain a reactive diluent for the purpose of reducing skin irritation, but is a conventionally known reactive diluent within a range that does not adversely affect the skin irritation and the stability of the water-containing resin composition. It does not prevent the combined use of a small amount of the agent.

The active energy ray-curable water-containing resin composition of the present invention contains, in addition to the above-mentioned essential components, vehicle and water, a hydrophilic solvent such as a lower alcohol, a colorant, a photoinitiator, and the like, if necessary. Additives such as a leveling improver may be appropriately used in combination without departing from the objects and effects of the present invention. Since the water-containing resin composition of the present invention itself has good leaving stability, it is not necessary to add a surfactant, and therefore, the water resistance of the cured film is good, and in particular, the film whitening phenomenon during immersion is prevented. be able to.

The optimum viscosity of the active energy ray-curable water-containing resin composition of the present invention cannot be uniquely determined because it varies depending on the use, but it is usually preferably about 2 to 500 cP / 25 ° C.

The active energy ray-curable water-containing resin composition of the present invention obtained as described above has excellent curability and water resistance, and has a relatively low viscosity and good stability over time. Various applications in which known non-aqueous active energy ray-curable resin compositions have been used, such as various overcoat agents for various plastic films, wood coatings, electrodeposition coatings, printing inks, various coating agents such as paper quality improvers, etc. Can be applied to laminating adhesives for paper and plastic film substrates. Furthermore, it can be suitably used as an auxiliary agent for improving the water dispersion stability of other active energy ray-curable resin compositions.

[0018]

EFFECTS OF THE INVENTION According to the present invention, curability and water resistance comparable to those of non-aqueous active energy ray-curable resin compositions are obtained, and relatively low viscosity and low skin irritation are exhibited. An aqueous active energy ray-curable resin composition having stability over time can be provided.

[0019]

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. In the following, "parts" and "%" are based on weight unless otherwise specified.

Example 1 In a flask equipped with a stirrer, a thermometer, an air blowing tube, and a reflux condenser, HMDI trimer (manufactured by Nippon Polyurethane Co., Ltd., trade name Coronate HX) 343.5 parts, hydroxypropyl acrylate 166.3 parts, 0.7 parts of 4-methoxyphenol and 0.007 parts of a polymerization inhibitor (manufactured by Wako Pure Chemical Industries, trade name Q-1301) were charged. Next, 0.14 parts of stannous octoate was charged while blowing air and stirring, and the temperature inside the system was raised to 75-80 ° C and kept for 1.5 hours, after which polyethylene glycol monomethyl ether (trade name, manufactured by Toho Chemical Industry, trade name) Methoxy PEG
# 400) 190.3 parts was added to react the residual isocyanate groups in the HMDI trimer with the hydroxyl groups in polyethylene glycol monomethyl ether. 80 parts of the obtained polyurethane acrylate was kept warm at 60 to 70 ° C., and 120 parts of deionized water was added and dispersed under stirring to obtain an emulsion having a nonvolatile content of 40%. The proportions of the components of the polyurethane acrylate used, the viscosity of the emulsion at 25 ° C. and the stability after standing for 1 month at room temperature are shown in Table 1 (the same applies hereinafter).

Example 2 The same flask as in Example 1 was charged with HMDI trimer 249.
1 part, hydroxypropyl acrylate 32.9 parts, pentaerythritol triacrylate 280.0 parts, 4
-0.7 parts of methoxyphenol and 0.007 parts of the polymerization inhibitor (Q-1301) were charged. Then stannous octylate 0.1 with air blowing and stirring
After charging 4 parts, the inside of the system was heated to 75 to 80 ° C. and kept for 1.5 hours, and 138.0 parts of methoxy PEG # 400 was added and reacted. The obtained urethane acrylate was dispersed in water in the same manner as in Example 1 to obtain an emulsion having a nonvolatile content of 40%.

Example 3 The same flask as in Example 1 was charged with HMDI trimer 225.
8 parts, pentaerythritol triacrylate 349.
1 part, 0.7 parts of 4-methoxyphenol and 0.007 part of the above-mentioned polymerization inhibitor (Q-1301) were charged. Next, 0.14 parts of stannous octoate was charged while blowing air and stirring, and the temperature inside the system was raised to 75-80 ° C.
After incubating for 5 hours, methoxy PEG # 400 125.
1 part was added and reacted. The obtained urethane acrylate was dispersed in water in the same manner as in Example 1 to give a nonvolatile content of 40
% Emulsion was obtained.

Example 4 A flask similar to Example 1 was charged with HMDI trimer 235.
3 parts, pentaerythritol triacrylate 363.
7 parts, 0.7 parts of 4-methoxyphenol and 0.007 part of the above-mentioned polymerization inhibitor (Q-1301) were charged. Next, 0.14 parts of stannous octoate was charged while blowing air and stirring, and the temperature inside the system was raised to 75-80 ° C.
After incubating for 5 hours, polyethylene glycol monomethyl ether (trade name methoxy PEG # 1 manufactured by Toho Chemical Industry Co., Ltd.)
000) 138.3 parts and methoxy PEG # 400
55.1 parts were added and reacted. The obtained urethane acrylate was dispersed in water in the same manner as in Example 1 to obtain an emulsion having a nonvolatile content of 40%.

Example 5 A flask similar to Example 1 was charged with HMDI trimer 235.
3 parts, pentaerythritol triacrylate 363.
7 parts, 0.7 parts of 4-methoxyphenol and 0.007 part of the above-mentioned polymerization inhibitor (Q-1301) were charged. Next, 0.14 parts of stannous octoate was charged while blowing air and stirring, and the temperature inside the system was raised to 75-80 ° C.
After incubating for 5 hours, polyethylene glycol monomethyl ether (trade name: methoxy PEG # 2, manufactured by Toho Chemical Industry)
25) 35.8 parts and Methoxy PEG # 400 6
5.2 parts was added and reacted. The obtained urethane acrylate was dispersed in water in the same manner as in Example 1 to obtain an emulsion having a nonvolatile content of 40%.

(Curing test) Various emulsions (active energy ray-curable resin water-containing composition) obtained in Examples 1 to 5 were subjected to varnish preparation and curing test of the varnish under the following conditions, and their film performances were obtained. Was evaluated. The evaluation results are shown in Table 2.

Varnish Preparation: The emulsion and 5% of the photoinitiator (Ciba Geigy, trade name Irgacure 184) with respect to the solid content were stirred and mixed until uniform. Hardening property: The above varnish was coated on an ABS plate in a film thickness of 5 μm, dried with hot air at 80 ° C. for 1 minute, and then irradiated with ultraviolet rays from a high pressure mercury lamp of 80 W / cm to make the film tack-free. The amount of energy (mJ) was evaluated. Preparation of cured film: In evaluation of pencil hardness, solvent resistance and water resistance, a cured film obtained by preparing a similar dry film and then irradiating the film with 100 mJ of ultraviolet rays to cure the film was used. Pencil hardness: According to JIS-K-5400. Solvent resistance: After the cured film is left in MEK for 24 hours, the appearance change is visually observed. Water resistance: After the cured film is left in deionized water for 24 hours, the appearance change is visually observed.

[0027]

[Table 1]

[0028]

[Table 2]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location G03F 7/027 513 7/038 // C08F 2/44 MCQ 7442-4J (72) Inventor Masaya Kageyama Arakawa Chemical Industry Co., Ltd. 1-9-1 Tsurumi, Tsurumi-ku, Osaka City (72) Inventor Satoshi Nagano 1-1-9 Tsurumi Chemical Co., Ltd., Tsurumi-ku, Osaka City

Claims (3)

[Claims] 1. An active energy ray-curable water-containing resin composition comprising a vehicle and water as essential components, wherein the vehicle comprises (A) an acrylic acid ester containing at least one hydroxyl group in the molecule, (B) an organic poly (ester). An active energy ray-curable water-containing resin composition, which is a reaction product of isocyanates and (C) polyethylene glycols containing at least one hydroxyl group. 2. In the vehicle, (C) is represented by the following general formula (1) H- (OCH ₂ CH ₂ ) _n —OR (1) (wherein R is a hydrogen atom or a lower alkyl group, and n is 3).
Indicates an integer of -25. ) The active energy ray-curable water-containing resin composition according to claim 1, which is represented by the formula (1). 3. The use ratio of each component in the vehicle is (A) :( B) = 25 to 70:30 to 75 (wt%), and (C) / {(A) + (B )} = 0.2
The active energy ray-curable water-containing resin composition according to claim 1, which satisfies the condition of?