JP2610746B2 - Active energy ray-curable composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active energy ray-curable composition. This composition can be used for printing ink of various printed matter, overprint varnish for paper, overprint varnish for plastic, overprint varnish for wood, potting material for decoration, and various protective coatings.

[0002]

2. Description of the Related Art Conventionally, active energy ray-curable compositions include an acrylic monomer having at least one unsaturated double bond reactive to active energy rays in the molecule, There is an acrylic oligomer having a double bond, an acrylic polymer having no reactivity, and a photopolymerization initiator.

[0003]

Acrylic polymers are toxic and rash when attached to the skin. In addition, since it emits a peculiar odor, there is odor pollution. Furthermore, acrylic polymers have poor compatibility with other components,
The solution of the composition becomes cloudy. Further, when a solution of the above composition is applied to a substrate and this film is cured, the adhesion between the cured film and the substrate is poor. It was also found that the abrasion resistance of this cured film was low.

[0004] It is an object of the present invention to reduce toxicity and odor as compared with conventional compositions, prevent cloudiness of a solution of the composition, increase the adhesion between a cured film of the composition and a substrate, and It is also to improve the friction resistance of the cured film.

[0005]

According to the present invention, there is provided a composition which is cured by irradiation with an active energy ray, comprising a urethane oligomer having a urethane bond, the urethane oligomer having a non-polymerization-reactive end. An active energy ray containing 100 parts by weight, 1 to 30 parts by weight of a photosensitive oligomer, 1 to 100 parts by weight of a photosensitive monomer, and 1 to 30 parts by weight of a photopolymerization initiator. It relates to a curable composition.

[0006]

The present inventors have conducted a search for a huge variety of resins, oligomers and monomers. As a result, when a urethane oligomer is used in place of the above-mentioned non-reactive acrylic polymer, very good characteristics can be obtained. I found that I could get it. In particular, a composition containing a photosensitive oligomer and a photosensitive monomer, when irradiated with active energy rays, undergoes polymerization shrinkage, but when a urethane oligomer is added to the composition,
It was found that this polymerization shrinkage was alleviated. This allows
The cured coating of the composition has shown excellent adhesion to substrates such as paper, plastic, wood and the like.

[0007] It has also been found that the addition of a urethane oligomer to the composition increases the toughness of the cured film and improves the wear resistance. This is considered to be because the structure of the urethane oligomer is composed of repeating tough urethane bonds. Moreover, it was found that even when the urethane oligomer was contained in the composition solution, the solution did not become cloudy.
In addition, by replacing the odorous and toxic acrylic polymer with urethane oligomer, the working environment when applying the composition solution and the commercial value of the composition are dramatically improved.

The urethane oligomer is a reaction product of an isocyanate compound and a compound having a reactive hydroxyl group. Examples of such isocyanate compounds include isophorone diisocyanate, diphenylmethane diisocyanate, tolylene diisocyanate, 1,5-naphthalene diisocyanate, tolidine diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, lysine diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and the like. it can.

As the hydroxyl-containing compound,

Embedded image There is an aliphatic glycol represented by the following structural formula. here,
R ¹ and R ² are each independently a hydrogen atom, a methyl group, an ethyl group or a propyl group. n is an integer of 2 to 10. Specific examples of this include ethylene glycol,
Propylene glycol, 1,4-butanediol, neopentyl glycol, diethylpropylene glycol,
Butyl ethyl propylene glycol, hexamethylene glycol, cyclohexane dimethanol, 1,10-decanediol and the like.

Embedded image As described above, glycols having a spiro ring in the molecule can also be used.

When a diisocyanate is reacted with a glycol, a urethane oligomer having a linear molecular structure is formed. Of these, those represented by the following structural formula are particularly preferred.

Embedded image A is a residue obtained by removing a hydroxyl group from a hydroxyl group-containing compound. D is a residue obtained by removing an isocyanate group from diisocyanate. n is an integer of 2 to 50.

When the value of n is 1, the effect of improving the strength of the cured product due to the strong urethane bond is small. Further, it was found that when the value of n exceeds 50, the crystallinity of the urethane oligomer becomes strong and the compatibility in the composition becomes poor. The case where n is 7 to 30 is particularly preferred.

[0012] The active ray energy rays refer to ultraviolet rays, energy rays, γ rays and the like. Examples of the photosensitive oligomer include commonly used monofunctional, bifunctional, and polyfunctional urethane acrylate oligomers, polyester acrylate oligomers, and epoxy acrylate oligomers. For example, "Aronix M-6100", "Aronix M-6200", "Aronix M-8060", "Aronix M-8100", "Aronix" manufactured by Toa Gosei Co., Ltd.
"M-1100", "Aronix M-1200", "Viscoat 700", "Viscoat 3700", "Viscoat 812", "Viscoat 813", "Viscoat 823" manufactured by Osaka Organic Co., Ltd.
"," Ebicryl 436 "," Ebicryl 438 "," Ebicryl 440 "," Ebicryl 501 "manufactured by UCB Corporation.
, "Ebicryl 754", "Ebicryl 150", "Ebicryl 38", "Ebicryl 39", "Ebicryl 40",
"Ebicryl 41", "Ebicryl 42", "Ebicryl 4"
3, "Ebicryl 44", "Ebicryl 45", "Ebicryl 46", "Ebicryl 47", "Ebicryl 48", SH
"Lipoxy SP-1509", "Lipoxy SP-1"
563 '', `` Lipoxy SP-2500 '', `` Lipoxy SP-4060 ''
, "Lipoxy SP-6000", "Lipoxy SP-9000",
"Ripoxy VR-60", "Ripoxy VR-90", "Go-Serac UV-1700B", "Go-Serac" manufactured by Nippon Gosei Co., Ltd.
UV-2000B "," Gorcerac UV-3000B "," Gorcerac UV-2700B "," Gorcerac UV-7000B "and the like. These may be used alone or as a mixture of two or more.

The photosensitive monomer may be monofunctional or polyfunctional. The following are exemplified. Methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate,
An acrylate or methacrylate of an alcohol having 1 to 12 carbon atoms, such as 2-ethylhexyl methacrylate, lauryl acrylate, and lauryl methacrylate. Trimethylolpropane diacrylate, trimethylolpropane dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, neopentyl glycol dimethacrylate, 1,6-hexanediol diacrylate, 1,6
-Polyol acrylates or polyol methacrylates, such as hexanediol dimethacrylate. Alkyl-substituted amino alcohol acrylates or alkyl-substituted amino alcohol methacrylates such as diethylaminoethyl acrylate and diethylaminoethyl methacrylate; Acrylamides such as N-acryloylmorpholine. Acrylic imides. N-vinyl-2-pyrrolidone,
Toloxyethyl acrylate, toloxyethyl methacrylate and the like. These may be used alone or as a mixture of two or more. Many of the above photosensitive oligomers and photosensitive monomers are also useful as photopolymerizable diluents.

As the photopolymerization initiator, benzoin, benzoin alkyl ether, benzyldimethyl ketal,
Examples include benzophenone, Michler's ketone, azoisobutyronitrile, 1-azobis-1-cyclohexanecarbonitrile, naphthalenesulfonyl chlorides, anthraquinones, and thioxanthones. These alone,
Alternatively, two or more kinds are mixed and used. When the amount of the photopolymerization initiator is less than 1 part by weight, the photocurability of the composition is poor.

[0015]

EXAMPLES First, urethane oligomers were synthesized according to the following synthesis examples. (Synthesis Example 1) A 1-liter reactor was equipped with a stirrer, a thermometer, a dropping funnel, a condenser, a temperature regulator, and a nitrogen gas blowing device. In this reactor, 200 g of isophorone diisocyanate was dissolved in 133 g of ethyl acetate, and the reaction temperature was maintained at 40 to 50 ° C. under a nitrogen atmosphere. Next, 124 g of diethylpropylene glycol was dissolved in 124 g of ethyl acetate, and this solution was added dropwise from a dropping funnel over 2 hours.
The reaction was carried out for 2 hours while maintaining the reaction temperature at 40 to 50 ° C. Next, 0.324 g of dibutyltin laurate was added to ethyl acetate 2
Dissolved in 29 g and added to the reactor. The reaction was maintained at 60 ° C. for 2 hours. It was confirmed from the infrared spectrum that the characteristic absorption of the isocyanate group (2250 cm ^-1 ) had disappeared, and the reaction was terminated. In this urethane oligomer, the number n of repeating units of the structural unit of one set of diisocyanate and glycol was 7.

(Synthesis Example 2) The same reactor as in Synthesis Example 1 was used. 2,4-tolylene diisocyanate in a reactor
200 g was dissolved in 133 g of ethyl acetate, and the reaction temperature was maintained at 40 to 50 ° C. under a nitrogen atmosphere. Next, 128 g of neopentyl glycol was dissolved in 128 g of ethyl acetate, and the resulting solution was added dropwise from a dropping funnel over 2 hours.
The reaction was performed for 2 hours while maintaining the temperature at 50 ° C. Next, 0.33 g of dibutyltin laurate was dissolved in 231 g of ethyl acetate and added to the reactor. The reaction was maintained at 60 ° C. for 2 hours. It was confirmed from the infrared spectrum that the characteristic absorption of the isocyanate group (2250 cm ^-1 ) had disappeared, and the reaction was terminated. The number n of repeating units in this urethane oligomer was 15.

(Synthesis Example 3) The same reactor as in Synthesis Example 1 was used. 2,4-tolylene diisocyanate in a reactor
200 g was dissolved in 133 g of ethyl acetate, and the reaction temperature was maintained at 40 to 50 ° C. under a nitrogen atmosphere. Next, 150 g of 1,4-butanediol was dissolved in 111 g of ethyl acetate, and the resulting solution was added dropwise from a dropping funnel over 2 hours.
The reaction was performed for 2 hours while maintaining the temperature at 50 ° C. Next, 0.31 g of dibutyltin laurate was dissolved in 222 g of ethyl acetate and added to the reactor. The reaction was maintained at 60 ° C. for 2 hours. It was confirmed from the infrared spectrum that the characteristic absorption of the isocyanate group (2250 cm ^-1 ) had disappeared, and the reaction was terminated. The number n of repeating units in this urethane oligomer was 15.

(Test Results of Composition) The urethane oligomer of each synthesis example was blended with other raw materials in the proportions shown in the following table, mixed well, and stirred to obtain an active energy ray-curable composition. Was. These were tested as overprint varnish compositions. Each composition was applied on a coated cardboard coated with an ultraviolet curable ink using a wire bar # 6. 80W / cm 3 high pressure mercury lamps (Model QRM2077A
: Oak Co., Ltd.) to irradiate the coated cardboard on the belt conveyor with ultraviolet light to cure the coating film.
Belt conveyor speed 6m / min, irradiation distance 150mm
And The various cured films thus obtained were used as test pieces.

The following items were tested. Adhesion: By attaching cellophane tape to the cured coating on the coated cardboard piece and peeling off the cellophane tape,
The adhesion between the coated cardboard and the cured coating was evaluated. When the coated cardboard piece was torn and adhered to the peeling surface of the cellophane tape, the adhesiveness was rated as “○”. When a part between the coated cardboard piece and the cured film was partially peeled off, the adhesion was evaluated as “Δ”. When peeling between the coated cardboard piece and the cured film over the entire surface, the adhesion was evaluated as “x”. Gloss: Measured with a gloss meter (manufactured by Tokyo Denshoku Co., Ltd.). Abrasion resistance: The cured film was scratched with a nail and examined for scratches. When no scratch was formed on the cured film, the abrasion resistance was evaluated as “「 ”. When the film was scratched thinly, the abrasion resistance was evaluated as “△”. When the cured film was peeled off at the part scratched by the nail, the abrasion resistance was evaluated as “x”. The measurement results are also shown in the table.

[0020]

[Table 1]

[0021]

[Table 2]

"Gorcellac UV-2000B": (Nippon Gosei Co., Ltd.) (urethane acrylate: TDI-based yellowing type) 1,6-HDDA: 1,6-hexanediol diacrylate.

As is apparent from the above results, the use of the urethane oligomer improved the adhesion of the cured film to the coated cardboard without adhesion, and also improved the abrasion resistance. In addition, the non-reactive acrylic polymer having odor and toxicity was eliminated, and the amount of acrylic oligomer was reduced.

From the results shown in the table, the characteristics are best when the urethane oligomer of Synthesis Example 2 is added. Further, among the same urethane oligomers, the amount of the photosensitive monomer 1,6-hexanediol diacrylate is 50 to 6
The characteristics are best when the amount is 6.7 parts by weight. In Examples 1 to 4 and 5 to 8, the characteristics were best when the amount of the photosensitive monomer was 66.7 parts by weight. In Examples 9 to 12, the characteristics were almost the same when the amount of the photosensitive monomer was in the range of 50 to 66.7 parts by weight.

[0025]

As described above, when the active energy ray-curable composition of the present invention is used, a cured film having excellent adhesion to a substrate and high abrasion resistance can be obtained. . In addition, even when the composition is dissolved in an organic solvent, the solution does not become cloudy. Moreover, since an acrylic polymer having an odor and toxicity is not used, the working environment when applying the solution of the composition and the commercial value of the composition are dramatically improved.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C09D 175/04 PHV C09D 175/04 PHV

Claims (3)

(57) [Claims] 1. A composition which is cured by irradiation with an active energy ray, comprising 100 parts by weight of a urethane oligomer having a urethane bond, the urethane oligomer having a non-polymerization-reactive terminal. 1 oligomer
An active energy ray-curable composition comprising: -30 parts by weight, 1-100 parts by weight of a photosensitive monomer, and 1-30 parts by weight of a photopolymerization initiator. 2. The active energy according to claim 1, wherein the urethane oligomer is a reaction product of a diisocyanate having two isocyanate groups per molecule and a hydroxyl-containing compound having two reactive hydroxyl groups per molecule. A line-curable composition. 3. The method according to claim 1, wherein the urethane oligomer is The active energy ray-curable composition according to claim 2, which is represented by the following structural formula. [A is a residue obtained by removing a hydroxyl group from the hydroxyl group-containing compound. D is a residue obtained by removing the isocyanate group from the diisocyanate. n is 2 to 50
Is an integer. ]