JP2002226519A - Energy ray-curable resin composition and paint using the same - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] A paint which gives a coating film which can be removed only with alcohol even from hard-to-remove stains such as shoe ink and hair dyeing solution,
And an energy ray-curable resin composition used for the same. SOLUTION: A urethane acrylate obtained by reacting a polyisocyanate (A) having an alicyclic structure with a (meth) acrylate compound (B) having at least one hydroxyl group in a molecule is provided. I do.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an energy ray-curable resin composition which can be cured by irradiation with energy rays, and a coating material using the same.

[0002]

2. Description of the Related Art Conventional building materials such as floors and walls,
In general, various structures and molded products are coated with a paint in order to protect the base material and keep the appearance.

Conventionally, as a coating material, a solvent type obtained by dissolving a synthetic resin with a solvent has been generally used. However, from the viewpoint of improving the working environment and preventing danger against fire, a resin curable by irradiation with energy rays is used. Various types of energy ray-curable paints have been developed, and have been put to practical use in a wide range of fields, such as decorative board coating, woodwork paints, paper coatings, resist materials, and adhesives.

[0004] One of the important required performances for such coating applications is stain resistance, and even in energy ray-curable paints, a fluorine-based surface modifier is used in combination in order to facilitate removal of adhered stains. (Japanese Patent Laid-Open No. 11-
No. 269287), those using a UV-curable silicone resin in combination (JP-A-11-29720), and those using a compound having a specific structure (JP-A-2000-3433).
No. 4, JP-A-8-217840) and various types of paints have been proposed.

[0005]

However, in the case of a coating film made of such an energy ray-curable paint,
Although it was possible to remove relatively easy-to-drop contaminants such as oil-based inks, it was difficult to remove hard-to-drop contaminants such as shoe ink and hair dyes. Further, the one disclosed in Japanese Patent Application Laid-Open No. Hei 8-259644 can cope with contamination caused by shoe polish, but its removal requires sequential treatment with alcohol, petroleum, and benzene, and its performance is sufficient. Was not. Therefore, there is a need for an energy ray-curable paint that provides a paint film that easily penetrates a paint film such as shoe ink and hair dyeing liquid and that can easily remove contaminants that are difficult to remove with alcohol alone.

The present invention has been made in view of the above, and has been made in consideration of the above circumstances. A paint which provides a coating film which can remove even hard-to-remove stains such as shoe ink and hair dyeing solution with only alcohol, and an energy ray used therefor An object is to provide a curable resin composition.

[0007]

According to a first aspect of the present invention, there is provided an energy ray-curable resin composition comprising: a polyisocyanate (A) having an alicyclic structure; It contains urethane acrylate obtained by reacting with a (meth) acrylate compound (B) having a hydroxyl group.

[0008] In the energy ray-curable resin composition, urethane acrylate comprises the component (A) and the component (B).
The component is prepared by mixing the isocyanate group in the component (A) with the hydroxyl group in the component (B) at a molar ratio of 1.00 / 1.00 to 1.00.
It is preferred that the reaction be carried out at a ratio in the range of /1.20 (claim 2).

[0009] The energy ray-curable resin composition may further contain a photopolymerization initiator.

[0010] The paint of the present invention comprises any one of the above-mentioned energy ray-curable resin compositions (claim 4).

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the polyisocyanate (A) having an alicyclic structure used in the present invention include hydrogenated diphenylmethane diisocyanate (hydrogenated MDI), isophorone diisocyanate and the like. They may be used, or a plurality of them may be used in combination.

Preferred examples of the hydroxyl group-containing (meth) acrylate (B) include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate and 2-hydroxyethyl methacrylate.
Hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, caprolactone-modified 2-hydroxyethyl acrylate, polyethylene glycol monoacrylate, polypropylene glycol monoacrylate, pentaerythritol triacrylate, dipentaerythritol pentaacrylate Can be Among them, 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate are preferably used. These may be used alone or in combination of two or more.

The components (A) and (B) have a molar ratio (NCO / OH) of 1.00 / 1.00 to 1 of an isocyanate group in the component (A) and a hydroxyl group in the component (B). .00
/1.20, preferably 1.00 / 1.00
The reaction is carried out at a ratio of 1.00 / 1.05. The molar ratio of hydroxyl groups is 1.
When it is less than 00, the remaining isocyanate impairs stain resistance. On the other hand, when the molar ratio of hydroxyl groups is greater than 1.20 with respect to the molar ratio of isocyanate, excess hydroxyl groups impair stain resistance.

The urethane acrylate can be synthesized by a known method. For example, a predetermined amount of (A)
The component and the component (B) are charged at a time, and are heated to 70 to 80 ° C. in the presence of a polymerization initiator such as hydroquinone monomethyl ether.
By heating and stirring until free isocyanate disappears.

When the resin composition of the present invention is formed into a paint, the resin composition can be diluted with an organic solvent such as ethyl acetate, methyl ethyl ketone and the like, and with monomers. The urethane acrylate content is preferably 50% by weight or more.

As the monomers used for dilution, known and commonly used ones can be used. Among them, typical ones are 2-ethylhexyl acrylate, styrene, methyl methacrylate, tetrahydrofurfuryl (meth) acrylate and phenoxy. Ethyl (meth) acrylate,
Isobornyl (meth) acrylate, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1 , 6 hexanediol di (meth) acrylate, EO-modified bisphenol di (meth) acrylate, PO-modified bisphenol di (meth) acrylate,
Trimethylolpropane tri (meth) acrylate, E
O-modified trimethylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, tris ((meth) acryloxyethyl) isocyanurate, dipentaerythritol hexa (meth) acrylate And dipentaerythritol penta (meth) acrylate. These may be used alone or in combination of two or more.

A photopolymerization initiator is added to the energy ray-curable resin composition of the present invention, if necessary.

The type of the photopolymerization initiator is not particularly limited, and known photopolymerization initiators can be used.
-Hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, benzoin isopropyl ether, benzophenone and the like. These may be used alone or in combination of two or more.

When a photopolymerization initiator is used, its addition amount is about 1 to 10% by weight, and about 3 to 5% by weight, based on the total amount of urethane acrylate and the above-mentioned optional monomers. % Is preferred.

The energy ray-curable resin composition of the present invention may further comprise a light stabilizer, an ultraviolet absorber,
Catalysts, colorants, antistatic agents, lubricants, leveling agents, defoamers, polymerization accelerators, antioxidants, flame retardants, infrared absorbers,
Surfactants, surface modifiers and the like can be added.

The energy ray source for curing the energy ray-curable resin composition of the present invention is not particularly limited. No.

[0022]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. In the following, all the mixing ratios and “%” are based on weight unless otherwise specified.

Synthesis Example 1 A flask was charged with 222 g (1 mol) of isophorone diisocyanate, 286 g (2.2 mol) of 2-hydroxypropyl acrylate, and 0.25 g of hydroquinone monomethyl ether.
The reaction was carried out at 80 ° C. until the residual isocyanate concentration became 0.1%, to obtain urethane acrylate C.

[Synthesis Example 2] Hydrogenated MDI 262 was added to a flask.
g (1 mol), 2-hydroxyethyl acrylate 24
3.6 g (2.1 mol) and 0.25 g of hydroquinone monomethyl ether were charged and reacted in the same manner as in Synthesis Example 1 to obtain urethane acrylate D.

[Comparative Synthesis Example 1] 168 g (1 mol) of hexamethylene diisocyanate and 267.8 g (2.06 mol) of 2-hydroxypropyl acrylate were placed in a flask.
And 0.22 g of hydroquinone monomethyl ether were charged and reacted in the same manner as in Synthesis Example 1 to obtain urethane acrylate E.

[Comparative Synthesis Example 2] 500 g of polypropylene glycol (molecular weight: 2000) (0.25
Mol) and 111 g of isophorone diisocyanate (0.
5 mol), and reacted at 70 to 80 ° C. until the residual isocyanate concentration becomes 3.4%. 67.6 g (0.52 mol) of 2-hydroxypropyl acrylate and 0.34 g of hydroquinone monomethyl ether
After the addition, the mixture was further reacted under the conditions of 70 to 80 ° C. until the residual isocyanate concentration became 0.1%, to obtain urethane acrylate F.

Table 1 shows the types of the components (A) and (B) and the NCO / OH ratio in the above synthesis examples and comparative synthesis examples.

[0028]

[Table 1]

[Examples 1 and 2, Comparative Examples 1 and 2] The urethane acrylates obtained in the above synthesis examples and comparative synthesis examples, 1-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator (Irgacure 184, Ciba-Geigy) And ethyl acetate as a diluent solvent were blended at the ratio shown in Table 2 and uniformly dissolved to prepare a total of four resin compositions.

The curability and stain resistance of the obtained resin composition were examined in the following manner. The results are also shown in Table 2.

[Curability] Each resin composition was applied to a glass plate with a 100 μm applicator and dried in an oven at 80 ° C. for 30 minutes to obtain a test sample, which was coated using a high-pressure mercury lamp of 80 W / cm. Integrated illuminance required to eliminate film surface tack (mJ /
cm ² ).

Stain resistance Each resin composition was applied to a glass plate with a 100 μm applicator, dried in an oven at 80 ° C. for 30 minutes, and dried at 200 mJ / cm using an 80 W / cm high-pressure mercury lamp.
Specimens cured with an integrated illuminance of cm ² were used as specimens, and four types of contaminants (oil-based inks (black, red), shoe ink, hair dye solution)
, The surface of the cured coating was contaminated, left for 24 hours, wiped off with ethanol, and the surface condition was visually observed. When the contamination was almost completely removed, the result was evaluated as ○, and when the contamination was remarkable, the result was evaluated as ×.

[0033]

[Table 2]

As can be seen from Table 2, the coatings of Examples 1 and 2 give a coating film having excellent curability and stain resistance, whereas the coatings without alicyclic polyisocyanate (Comparative Example 1) In the coating film of No. 1, easily removable contaminants such as oil-based ink can be removed, but it is difficult to remove shoe ink and hair dyeing liquid. In addition, even when the alicyclic polyisocyanate was used, the one in which a polyol other than the hydroxyl group-containing (meth) acrylate was used in combination in the urethane acrylate skeleton (Comparative Example 2) was inferior not only in stain resistance but also in curability.

[0035]

According to the energy ray-curable resin composition of the present invention, a coating film which is excellent in curability and can be easily removed only with alcohol even for hard-to-remove stains such as shoe ink and hair dye solution. A paint is obtained.

Continued on the front page F-term (reference) 4J011 QA03 QA09 QA13 QA23 QA24 QA38 QA39 QA45 QA46 QB16 SA01 SA21 SA31 SA51 VA01 WA02 4J027 AC03 AC04 AC06 AG03 AG04 AG24 AJ08 BA05 BA07 BA20 BA26 BA28 BA29 CB10 P08PAJB03 FA05 4J100 AB02Q AL03Q AL04Q AL08Q AL62Q AL63Q AL66P AL66Q AL67P AL67Q BA08P BA21P BA38P BC04P BC08Q BC43Q BC45Q BC53Q BC75Q CA01 CA04 DA36 FA03 JA01

Claims (4)

[Claims] An urethane acrylate obtained by reacting a polyisocyanate (A) having an alicyclic structure with a (meth) acrylate compound (B) having at least one hydroxyl group in a molecule. Energy ray-curable resin composition. 2. The method according to claim 1, wherein the urethane acrylate is (A)
The component and the component (B) were prepared such that the molar ratio of the isocyanate group in the component (A) to the hydroxyl group in the component (B) was 1.00 / 1.0
The energy ray-curable resin composition according to claim 1, wherein the reaction is carried out at a ratio within a range of 0 to 1.00 / 1.20. 3. The energy ray-curable resin composition according to claim 1, further comprising a photopolymerization initiator. 4. A paint comprising the energy ray-curable resin composition according to claim 1.