JPS6043364B2 - radical curable composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel radical-curable composition that is cured by energy such as ultraviolet rays, electron beams, heat, etc., and provides useful coatings or molded products.

More specifically, it contains a urethane prepolymer with unsaturated groups as its main component, has a low viscosity, and contains virtually no volatile solvents, so it meets the requirements for air pollution prevention and resource conservation. The present invention relates to a composition with extremely excellent properties. For radical curable compositions,
Various compositions are known including unsaturated polyesters.

Among them, it is well known that urethane-based materials are excellent, especially when curing with ultraviolet rays, because they are less susceptible to the effects of oxygen in the air and have a faster curing speed. Also, tolylene diisocyanate, hexamethylene diisocyanate,
It is also known that a urethane prepolymer obtained by reacting a diisocyanate compound such as xylylene diisocyanate with a monohydric alcohol having an unsaturated group can be radically cured by ultraviolet rays, electron beams, heat, or the like.

However, although urethane prepolymers synthesized from diisocyanates have low viscosity, they are not satisfactory in terms of curing speed. In fact, if the number of unsaturated groups in one molecule of the urethane prepolymer is two, the gelation rate during radical curing is low, which limits its practical use. Therefore, in general, in order to convert the diisocyanate into a trifunctional isocyanate, an adduct with trimethylolpropane or a trifunctional isocyanate is used.
A method has been devised in which a urethane prepolymer is obtained by similarly reacting a monohydric alcohol or the like having an unsaturated group using a biuret body corresponding to the urethane polymer. However, trifunctional isocyanates derived from diisocyanates are
It is not synthesized according to theory and ends up containing high molecular weight by-products and a wide molecular weight distribution. Therefore, although the urethane prepolymers derived therefrom have a cure rate superior to those made from diisocyanates, they have very high viscosities and have little flow at room temperature. Therefore, in practice, a large amount of diluent must be used, resulting in a slow curing rate. As a result of extensive research aimed at eliminating these drawbacks, the present inventors have discovered a new radical-curable composition with significantly improved viscosity and high curing speed compared to conventional compositions, and have completed the present invention. That is, in the present invention, 0.5 monohydric alcohol having a radically polymerizable unsaturated group is added to 1 mole of triisocyanate represented by the general formula (R is a divalent hydrocarbon residue having 2 to 8 carbon atoms). ~5 moles, m
A prepolymer containing a urethane bond obtained by reacting an alcohol with a valence (m is an integer of 2 to 4) of 0 to 2/mmol is
% or more of saliva, and further contains a radically polymerizable ethylenically unsaturated compound and/or an organic solvent as other components.

The triisocyanate as component A used in the present invention is represented by the above general formula, and typical examples thereof include 2,6-diisocyanate caproic acid-β-isocyanate ethyl ester, and 2,6-diisocyanate caproic acid-β-isocyanate ethyl ester. Acid-γ-isocyanate propyl ester, 2,
6-diisocyanate caproic acid-α-methyl-β-isocyanate ethyl ester, 2,6-diisocyanate caproic acid-β, β-dimethyl-γ-isocyanate propyl ester, 2,6-diisocyanate caproic acid-ω-isocyanate octyl ester ,2,6-
Examples include diisocyanate caproic acid mono(4-isocyanatecyclohexyl) ester and 2,6-diisocyanate caproic acid-(4-isocyanate benzyl) ester.

All of these are obtained by phosgenation of esters with lysine and amino alcohols. In this case, if the number of carbon atoms in R in the above general formula becomes larger than 8, the isocyanate content of the triisocyanate becomes too small and the viscosity becomes high, which is not suitable for the present invention. Examples of the monohydric alcohol having radical polymerizability as component B used in the present invention include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, and 2-hydroxypropyl acrylate. -Hydroxypropyl, diethylene glycol monoacrylate, diethylene glycol monoacrylate, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, butanediol monoacrylate, butanediol monomethacrylate, polypropylene glycol monoacrylate, polypropylene glycol monomethacrylate, 3-chloro-2-hydroxypropyl acrylate , 3-chloro-2-hydroxypropyl methacrylate, vinyl alcohol, allyl alcohol 7 alcohol, cinnamic alcohol and the like.

Others: glycerin diacrylate, glycerin dimethacrylate, trimethylolpropane diacrylate,
Monohydric alcohols having two or more unsaturated groups, such as trimethylolpropane dimethacrylate, pentaerythritol triacrylate, and pentanoerythritol trimethacrylate, can also be effectively used in the present invention. These compounds may be used alone or in combination of two or more. Examples of m-hydric alcohols used as component C in the present invention include ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol,
There are dihydric alcohols such as neopentyl glycol, polyethylene glycol, and polypropylene glycol, trihydric alcohols such as glycerin, trimethylolethane, and trimethylolpropane, and tetrahydric alcohols such as pentaerythritol.In addition, saturated or unsaturated alcohols have a hydroxyl group at the end. These include, but are not limited to, polyesters. These compounds may be used alone or in combination of two or more. When producing the urethane prepolymer which is the main component constituting the composition of the present invention, 1 mole of component A is reacted with 0.5 to 5 moles of component B and 0 to 2 mole of component C. . When the amount of component B is less than 0.5 mole, the curability becomes extremely poor and the stability of the urethane prepolymer becomes poor. Moreover, if it exceeds 5 moles, there will be too much monohydric alcohol that does not react with the triisocyanate, which will adversely affect the performance of the cured product. Furthermore, if the C component exceeds 2/mmol, problems such as formation of a urethane prepolymer with an extremely high molecular weight or gelation may occur. Methods for adding the above components include batch charging, addition of triisocyanate, addition of alcohol, and any of these methods are useful for producing the urethane prepolymer. In addition,
In addition to m-hydric alcohols, compounds that can be used equally well include compounds having functional groups that react with isocyanate groups, such as polyvalent amino compounds, polyvalent carboxyl compounds, and polyvalent mercapto J compounds.

If the viscosity of the reaction mixture during production of the urethane prepolymer becomes too high, gelation may occur during production.

In the present invention, in order to smoothly proceed with the production of the urethane prepolymer, the following ethylenically unsaturated compounds or organic solvents may be present in the reaction system in advance. Examples of the ethylenically unsaturated compounds include methyl acrylate, methyl methacrylate, ether acrylate, ethyl methacrylate, n- and i-propyl acrylate, n- and i-propyl methacrylate, and n- and i-acrylate. and t-butyl, methacrylic acid n-, i
- and t-butyl, 2-ethylhexyl acrylate,
2-ethylhexyl methacrylate, lauryl acrylate, lauryl methacrylate, cyclohexyl acrylate,
Cyclohexyl methacrylate, vinyl acetate, vinyl chloride, vinylidene chloride, acrylonitrile, methacrylonitrile, styrene, vinyltoluene, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, polyethylene glycol diacrylate, polyethylene glycol diacrylate Methacrylate, propylene glycol acrylate, propylene glycol dimethacrylate, polypropylene glycol diacrylate, polypropylene glycol dimethacrylate, 1,3-butylene glycol diacrylate,
1,3-butylene glycol dimethacrylate, 1,4-butylene glycol diacrylate, 1,4-butylene glycol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, divinylbenzene, diallyl phthalate, trimethylolethanetri There are compounds that do not react with isocyanate groups, such as acrylate, trimethylolethane trimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, glycerin triacrylate, glycerin trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, etc. Alternatively, it can be used as a mixture of two or more.

In addition, the above-mentioned organic solvents include ketone-based, ester-based,
Those that do not react with isocyanate groups, such as hydrocarbons and aromatics, are used. The urethane polymer, which is a component constituting the composition of the present invention, needs to be contained in an amount of 2% by weight or more.

This is because this urethane polymer has high reactivity, and this property is utilized to maintain a high curing rate. This is also to maintain high mechanical properties, particularly flexibility, of the finally obtained cured resin. Another reason is that this urethane polymer has a low viscosity even without a solvent and is easy to handle, so this is to take advantage of these properties. In the present invention, also,
It is also possible to add the ethylenically unsaturated compound and the organic solvent after producing the urethane prepolymer.

In this case, it goes without saying that in addition to the above compounds, saturated or unsaturated compounds having carboxyl groups, hydroxyl groups, amino groups, amide groups, mercapto groups, epoxy groups, etc. can be used. . The reaction temperature for producing the urethane prepolymer of the present invention may be within a range in which the radically polymerizable unsaturated groups do not react, and is preferably 30 to 120°C, more preferably 40 to 100°C.
'C.

The reaction proceeds even without a catalyst, but in order to make it more efficient, 0.01 to 2% by weight of a known catalyst such as a tertiary amine, a quaternary ammonium salt, or an organic tin compound is added.
It may be added to the reaction system. Furthermore, in order to prevent gelation, 0.001 to 1% by weight of a polymerization inhibitor such as phenols or quinones may be added as necessary.

The composition of the present invention contains the ethylenically unsaturated compound and organic solvent for the purpose of improving the performance of the cured product, facilitating the production of the urethane polymer, and improving workability during use. In addition, a polymer compound, a plasticizer, etc. can be included. The polymer compound mentioned here is a commonly used saturated or unsaturated compound, and is added mainly for the purpose of modifying the cured product. Examples of the polymer compound include acrylic resin, polyester resin,
Examples include polyamide resins, epoxy resins, urethane resins, cellulose derivatives, and the like. Furthermore, examples of plasticizers added for the same purpose include phthalate esters,
Examples include adipate esters, phosphate esters, and chlorinated paraffins. By providing an appropriate radical source, the composition of the present invention thus obtained cures rapidly even in the presence of air, providing transparent coatings and molded products.

In addition to low viscosity and high curability, by selecting a polyfunctional alcohol, you can further increase the concentration of unsaturated groups to improve curability, improve the flexibility of the cured product, etc. depending on the application. The performance of cured products can be changed. Radical sources include ultraviolet rays (using photosensitizers), electron beams,
Heat (polymerization catalyst), etc. can be used.

When curing the composition of the present invention with ultraviolet rays, it is essential to use the photosensitizer described below. Examples of photosensitizers include benzyl, diacetyl, benzophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, Mihira's ketone, baraquinone, dibenzylnidisulfide, 2,4- Dichlorobenzophenone, P-bromobenzophenone, xanthone, benzanthrone, uranyl nitrate, etc. can be mentioned. The amount of photomultiplier to be used is 0.1 to 1 (1) part of the composition.
About 10 parts is preferable. The composition after addition of photomultiplier 3 is as follows:
After coating or casting in a conventional manner, it can be easily cured by irradiation with a high, medium or low pressure mercury lamp, carbon arc, xenon lamp, etc. as a light source. Since the composition of the present invention uses a trifunctional isocyanate with a low viscosity, the urethane-bound prepolymer produced therefrom also has a very low viscosity and a high concentration of radically curable unsaturated groups. Therefore, a composition with low viscosity and high curability is realized, and is particularly suitable for curing with ultraviolet light, which has relatively low energy. When curing with an electron beam, a catalyst is generally not required because the accelerated electron beam itself has the ability to attack unsaturated groups in the composition and generate radicals.

Here, the electron beam refers to various electron beam accelerators such as Kotscroft type, Kotscroft-Walton type, Pan-de-Graph type, resonant transformer type, insulated core transformer type, linear type, Dynamitron type, and high-frequency type. means an electron beam emitted from a ion beam with energy energy in the range of 0.1 to 3 MeV. Furthermore, similar radiations, such as Cobalt-601Cesium-13
It can also be cured using an industrially available radiation source such as gamma rays such as 7, β rays such as strontium 901 krypton, and X rays.

Furthermore, the composition of the present invention can be thermally cured by adding a thermal polymerization catalyst, and examples of thermal polymerization catalysts that can be used here include benzoyl peroxide, methyl ethyl ketone peroxide, kyumene hydroperoxide, and azobis There are isobutyronitrile, azobisvaleronitrile, etc., but when low-temperature curing is expected, redox combinations of cobalt naphthenate, manganese naphthenate, dimethylaniline, diethylaniline, amines, mercaptans, etc. are used as accelerators. system can be used. In addition, pigments, dyes, fillers, etc. can also be added to the composition of the present invention, if necessary. The low viscosity of the composition of the present invention,
High curability is an extremely useful feature when used in paints, inks, printing plates, adhesives, molding materials, etc. Examples and comparative examples are given below to help understand the present invention.

Example 1 2,6-diisocyanate caproic acid-β-isocyanate ethyl ester (hereinafter RLTI
(abbreviated as J above) 267f (1 mol) and ethyl acetate 26
5y, and while stirring, 2-hydroxyethyl acrylate (hereinafter abbreviated as RHEAJ) 348y (3
A mixture consisting of mol), 0.9y of hydroquinone and 0.9g of triethylenediamine was added dropwise over a period of 2 hours.

During this time, the internal temperature was controlled at 40°C or less. After dropping, if kept at the same temperature for an hour, the infrared absorption spectrum shows 22
50c! The absorption of the n-1 isocyanate group completely disappeared. When ethyl acetate was distilled off from the solution thus obtained under reduced pressure, the urethane prepolymer was obtained as a pale yellow sticky liquid with a viscosity of 300 poise (same at 23° C. or lower).

Add 4 parts of benzoin isobutyl ether to 1 (1) part of this urethane prepolymer, form a 20μ thick layer on a 100μ polyester film, and burn it for 10cm with an 800W high pressure mercury lamp (manufactured by Ushio Inc., 16W/Cm).
As a result of irradiation from a distance of , it was possible to completely cure the material in 1 minute.

Note that the intensity of the ultraviolet rays at this time was 90 W/d. Comparative Example 1 Desmodyur N-75 containing a biuret form of hexamethylene diisocyanate was prepared in the same manner as in Example 1.
(manufactured by Bayer, nonvolatile content 75%) was charged into a 250-dough flask, HEAll6yl hydroquinone 0.37
A mixture of 0.37y and 0.37y of triethylenediamine was added dropwise over a period of 2 hours.

During this time, the internal temperature was controlled to below 40℃, and after dropping
It was kept at 50'C for the whole time. It was confirmed by infrared absorption spectrum that the isocyanate groups in the solution after the reaction were completely consumed. When the solvent was distilled off from the solution thus obtained under reduced pressure, the urethane prepolymer was obtained as a pale yellow, highly viscous material with a viscosity of 6,700 poise.

When the curability of this urethane-bound prepolymer was compared under the same conditions as in Example 1, it was found that it was still sticky even after 1 minute of irradiation, and 2.5 minutes of irradiation was required to completely cure it. Further, when 47 parts of trimethylolpropane triacrylate was added to the concave portion of urethane prepolymer 1 and the viscosity was the same as in Example 1, curability was compared. It required a lot of irradiation. Example 2 By the same operation as in Example 1, 53f(a).
2 mol) and 92y of ethyl acetate, and prepared polyethylene glycol monomethacrylate (NOF 1 Nisan Bremmer PE-200, demonstration! IOH value 207).
A mixture consisting of 0.3y of 162y1 hydroquinone and 0.3y of triethylene diamine was heated in 1. while keeping the internal temperature at 40°C. It took some time to drip.

After the dropwise addition, the reaction was carried out at 50°C for 8 hours, and the isocyanate groups completely disappeared. When ethyl acetate was distilled off from the resulting solution under reduced pressure, the urethane prepolymer was obtained as a pale yellow sticky liquid with a viscosity of 41 poise.

Curability was examined under the same conditions as in Example i and found that 2. It was cured by dusting and a highly flexible film was obtained.

Example 3 11EA174y (1.5 mol), trimethylolpropane triacrylate 138f and hydroquinone j
0.5y of monomethyl ether was charged, and while maintaining the temperature at 80°C, 140.5f of 2,6-diisocyanate caproic acid mono-γ-isocyanate propyl ester (a). 5 mol) was added dropwise over 1 hour.

After 5 hours of reaction at this temperature, the isocyanate groups completely disappeared. The resulting composition had a nonvolatile content of 100% and a viscosity of 30 poise. When the curability of this composition was examined under the same conditions as in Example 1, 1. It was completely hardened in the process.

Example 4 LTI 267f (1 mol), polyester glycol acrylate (Shin Nakamura Chemical Co., Ltd. RA-9G, approximately 9 ethylene glycol units) 307.5y, and hydroquinone 1da were placed in a flask and heated to 40°C. .

While stirring, add HEA45O. A solution consisting of 5f (3.9 mol) and triethylenediamine 1y was added dropwise over a period of 1 hour, and the reaction was further allowed to proceed for 1 hour at the same temperature, whereby the isocyanate groups completely disappeared. The composition thus obtained was a slightly yellow liquid with a viscosity of 9 poise.

When the curability of this composition was examined under the same conditions as in Example 1, 2. It was possible to obtain a coating that was completely cured and had excellent flexibility.

Example 5 To the urethane prepolymer 20W obtained in Example 1, (1) part of methyl methacrylate was added and uniformly dissolved.

This solution was poured into a glass vessel with an inner diameter of 10 TSR, and was completely cured by irradiation for 3 hours at a dose rate of 1 Mrad/Hr using 1000 Curie cobalt 60 as a radiation source. The cured product was a molded product with excellent solvent resistance and mold resistance, and was a major improvement over the drawbacks of polymethyl methacrylate plates.

Example 6 The urethane prepolymer part, flexible nylon stamp part, and 1 part of benzoin methyl ether obtained in Example 1 were dissolved in 200 mt of denatured alcohol, applied to a surface-treated aluminum plate, and heated at 80°C. It was dried for 1 hour.

Next, through the image, 10C from four 20W low pressure mercury lamps.
Irradiation was performed for 5 minutes at a distance of Tn. After irradiation, unexposed areas were washed away using denatured alcohol. The printing plate obtained by this method had excellent image reproducibility and sensitivity, and particularly excellent printing durability. Example 7 Part of the urethane prepolymer obtained in Example 2, part (w) of 2-hydroxyethyl methacrylate, part (a) of ethoxyethyl methacrylate, 0.4 part of methyl ethyl ketone peroxide (55% solution), and cobalt naphthenate (
(metal content: 6%) was mixed.

This mixture was applied to a bonderite-treated steel plate (#144) to a thickness of 20 μm using a percoater and heated at 70° C. to give a hardness of H. What is the name of leaving this painted plate at room temperature for a day, and what is the hardness as it hardens further? It became. The acid resistance, alkali resistance, solvent resistance, adhesion, etc. of the coating film were at a practical level. Example 8 1 part of the composition obtained in Example 4, 1 part of rutile titanium oxide, 1 part of Thai Bake R-630J (Ishihara Sangyo KK),
A part of benzyl and a part of ethyl acetate were kneaded using a three-roll roll to obtain an ultraviolet curable paint.

The thus obtained white paint having a non-volatile content of 90% or more has a viscosity that can be coated with a percoater.

An alkyd intermediate coating for automobiles was applied to a zinc phosphate-treated iron plate (Bonderite #144) to a dry film thickness of 20 μm, and heated at 140° C. for three times. Next, it was wet-sanded with a No. 600 sand vapor and dried with a hair dryer to prepare a test plate. Apply the above white paint to this test board to a thickness of 30 μm.
It was coated with a percoater so that it became 2. under the same irradiation conditions as in Example 1. After irradiation, it was completely cured and the surface was in excellent condition. The hardness of the coating film is targeted, and the adhesion (
The score was 1001100.

In addition, 180 tons passed up to 4WJφ, and the result of the DuPont impact test was 1 kg x 30 cm. Example 9 267y (1 mol) on LTI and 233q of ethyl acetate were charged into a four-loop flask equipped with a reflux condenser, thermometer, stirrer and dropping load, and heated to 40°C.

While stirring, a mixture consisting of 232y (2 moles) of HEA, 0.8y of hydroquinone monomethyl ether, and 0.8y of triethylenediamine was added dropwise over a period of 3 hours. After the dropwise addition was completed, the temperature was raised to 50°C and the mixture was reacted for 5 hours. Here, when 1,4-butanediol 45y (0.5 mol) was added and reacted for 2 Cff at the same temperature, the absorption of the isocyanate group of 2250cTr1-1 completely disappeared in the infrared absorption spectrum. The urethane prepolymer solution (70% non-volatile content) thus obtained was a slightly yellow transparent liquid with a viscosity of 2 poise. 2.8 parts of benzoin isobutyl ether was added to 100 parts of this urethane prepolymer solution to form a layer with a thickness of 20 μm on a 100 μm polyester film.

800W high pressure mercury lamp (manufactured by Ushio Inc., 16W/Cm)
When irradiated at a distance of 10 cm from the surface, complete curing could be achieved in 0.5 minutes.

Note that the intensity of the ultraviolet rays at this time was 90 W/bo. Comparative Example 2 By the same operation as in Example 9, Desmodyur N
-75 (manufactured by Bayer, non-volatile content 75%), 289y
I put it in a flask.

Note that before starting the reaction, the solvent was removed under reduced pressure. Then, 183 g of ethyl acetate was added and heated to 40°C. While stirring, add HEAll6y (1 mol), hydroquinone monomethyl ether 0.6y and triethylenediamine 0
．． A mixture consisting of 6y was added dropwise over a period of 3 hours.
After the dropwise addition was completed, the temperature was raised to 50°C and the mixture was reacted for 3 hours. Here, 1,4-butanediol 22.5y (0.25 mol)
was added and reacted at the same temperature for 8 hours, and the isocyanate groups completely disappeared. The thus obtained urethane prepolymer solution (as in Example 9, an ethyl acetate solution with a non-volatile content of 70%) was a pale yellow transparent liquid with a viscosity of 20 poise, which was as high as 10 f8 in Example 9.

When the curing properties were compared under the same conditions as in Example 9, it was cured with two powders, and the time required for curing was four times that of Example 9.

Example 10 By the same operation as in Example 9, 267y(
1 mol) and 987y of ethyl acetate were placed in a plastic bottle, and a mixture of 232y of HEA (2 mol), 2y of hydroquinone, and 2g of triethylenediamine was heated to an internal temperature of 40°C.
It took 2 hours to drip while maintaining the temperature, and after 50'
The reaction was carried out at C for 5 hours.

Next, polyethylene adipate (
Nipporan 4002, Nippon Polyurethane Kogyo KK)
When 48y (0.5 mol) was added and the reaction was further carried out at 50°C for ~ hours, the isocyanate groups completely disappeared. When ethyl acetate is distilled off from the solution thus obtained under reduced pressure,
The urethane prepolymer was obtained as a slightly yellow transparent viscous liquid with a viscosity of 510 poise.

When 1 (1) part of this urethane prepolymer was mixed with w part of methyl ethyl ketone and 4 parts of benzoin isopropyl ester, the curability was examined under the same conditions as in Example 1.
．． It was completely hardened in the process.

Example 11 43 parts of the urethane prepolymer solution obtained in Example 9, the soluble nylon stamp and 1 part of benzoin methyl ether were dissolved in 150 mL of denatured alcohol.
Coated on a surface-treated aluminum plate and dried in a hot air dryer for 50 minutes.
It was dried with Cl for 6 hours.

Next, through the image, 10c from four 20W low pressure mercury lamps.
It was irradiated for 3 minutes at a distance of m. After irradiation, unexposed areas were flushed out using denatured alcohol. The printing plate obtained by this method had excellent image reproducibility, sensitivity, and printing durability. Example 12 1 (4) parts of the urethane prepolymer solution obtained in Example 9, polyethylene glycol diacrylate (Shin Nakamura Chemical KKrA-9G.j approximately 9 ethylene glycol units)
A transparent paint was obtained by mixing 0.5 parts of 3-Kusaka Erosil (2491/380) and 4 parts of benzoin isobutyl ether.

A 5T7t thick precious wood plywood was used as the object to be coated, and a two-component urethane wood sealer for sealing was sprayed on it to a dry film thickness of 5μ, and after application, it was cured at room temperature for 2 hours.

Next, the above transparent paint was sprayed to a dry film thickness of 50 μm, and after setting for 5 minutes, irradiation was performed for 1 minute under the same irradiation conditions as in Example 1. The surface hardness of painted plywood is aimed at,
Adhesion 1001100. Impact resistance 500y x 40cm (
DuPont type, 117), cold check (-20℃×
2 hours, Type 60 C x 2 hours) No change for 20 cycles, and excellent water resistance, chemical resistance, etc.

Example 13 300 parts of the urethane prepolymer obtained in Example 10, 2
- 1 (1) part of ethylhexyl methacrylate, 5 parts of 2-hydroxyethyl methacrylate, 1 part of rutile-type titanium oxide, 1 part of Tybake R-630J (Ishihara Sangyo KK), and 3 parts of phthalocyanine blue (Dainichiseika Kagyo KK) W
A portion was placed in a pebble mill and dispersed for 16 hours.

Next, ethylene glycol dimethacrylate 5(2) was added and thoroughly mixed to obtain a solvent-free paint.
Thickness 5 with sanded surface? A layer with a thickness of 60 μm was formed on a slate board using a curtain flow coater.

Then, in a nitrogen atmosphere with an oxygen concentration of 0.1% or less, 1Me
When irradiated with a dose of 3 Mrad from a pan de graph of V1100 pA, it was completely cured. The color slate board thus obtained showed no abnormalities in the water resistance test for one month, and was cold checked (-20'Cx2hrl8OOCX).
2llrlllO cycles) were also passed. There was no change in appearance after 50 (b) tests on the weatherometer, and the gloss retention rate was 98%. What is the hardness of the coating film when applied and cured on a glass plate? It was hot. Examples 1 to 1 above
The component ratios in the composition described in No. 3 are summarized in Table 1 below.

In Table 1, the urethane prepolymer component ratio of the present invention was calculated using the following formula.

Urethane prepolymer component ratio =

Claims (1)

[Claims] 1. For 1 mol of triisocyanate represented by the general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (R is a divalent hydrocarbon residue having 2 to 8 carbon atoms), a radical polymerizable 0.5 to 5 mol of monohydric alcohol having an unsaturated group, m
A prepolymer containing a urethane bond made of 0 to 2/m mol of an alcohol of opposite valence (m is an integer of 2 to 4) is
A radical curable composition containing 0% by weight or more and further containing a radically polymerizable ethylenically unsaturated compound and/or an organic solvent as other components.