JP3475528B2 - UV curable resin composition and coating agent containing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition which is cured by irradiation with ultraviolet rays, and more particularly to an ultraviolet curable resin composition useful as a coating agent for plastic films and metals and a coating agent containing the same.

[0002]

2. Description of the Related Art A resin composition which is cross-linked and cured in a short time by irradiation of ultraviolet rays has hitherto used a cationic polymerization composition using a cationic initiator and an epoxy resin, and a radical initiator and an unsaturated resin. The radical polymerization type composition was mainly. As a cationic polymerization type ultraviolet curable resin composition, in order to improve the physical properties of the cured coating film obtained, studies have been made to use an epoxy resin and other compounds in combination, and an ultraviolet curable resin containing an epoxy resin and a polyester resin is used. Mold resin compositions are disclosed in Japanese Examined Patent Publication No. 2-30326 and Japanese Unexamined Patent Publication No. 5-186755. However, as is well known, cationic polymerization systems have the drawback that curing is inhibited by the humidity in the atmosphere during curing, and the resulting cured coating film has sufficient adhesion, coating hardness, and processability. Does not mean

In order to overcome the drawbacks of the above-mentioned cationic polymerization type ultraviolet curable resin composition, a method of simultaneously performing cationic polymerization and radical polymerization by further adding a radical polymerizable substance and a photoradical initiator has been proposed. Has been considered. For example, a composition in which an epoxy resin is used in combination with a liquid cycloaliphatic or aromatic diacrylate as a radical polymerizable substance, a radical photoinitiator and an OH-terminated polyether, polyester or polyurethane is disclosed in JP-A-6-228413. However, the adhesion to the substrate is not yet satisfactory, and the coating film hardness and processability are insufficient.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ultraviolet curable resin composition which gives a coating film having excellent adhesion to plastic films and metals, coating film hardness and processability.

[0005]

The present invention provides (A) 40 to 90 parts by weight of an epoxy compound which is liquid at room temperature, (B) 5 to 50 parts by weight of a polyester resin, and (C) a cationic photopolymerization initiator (A). ) 1 to 15 parts by weight per 100 parts by weight,
1 to 50 parts by weight of (D) an isocyanuric ring compound having an acryloyl group and / or a methacryloyl group, and 1 to 15 parts by weight of (E) a photoradical polymerization initiator based on 100 parts by weight of (D). Provided is a characteristic ultraviolet-curable resin composition.

The epoxy compound (A) which is liquid at room temperature is a compound having at least one epoxy group,
Used in an amount of ˜90 parts by weight. If it is less than 40 parts by weight, the ultraviolet curability will deteriorate, and if it exceeds 90 parts by weight,
The effect of improving the adhesion, workability and hardness of the obtained coating film is not observed. As the epoxy compound (A) which is liquid at room temperature, conventionally known aromatic epoxy compounds, alicyclic epoxy compounds, and aliphatic epoxy compounds can be used alone or in combination depending on the required performance. At least 50 cycloaliphatic epoxy compounds are used because of the rapid curing rate by ultraviolet rays.
It is particularly preferable that the content is wt%. As the alicyclic epoxy compound, those containing cyclohexene oxide or cyclopentene oxide in its molecular structure are preferably used.

Specific examples of the alicyclic epoxy compound will be given below.

[Chemical 1]

[0008]

[Chemical 2]

[0009]

[Chemical 3]

Examples of the aliphatic epoxy compound include polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether and trimethylolpropane triglycidyl ether. Examples of the aromatic epoxy compound include cresol novolac epoxy resin and bisphenol type epoxy resin.

The polyester resin (B) is a linear polyester resin derived from polybasic acids and polyhydric alcohols, and is used in an amount of 5 to 50 parts by weight, preferably 10 to 30 parts by weight. . If it is less than 5 parts by weight, the adhesion to organic films and metals, coating film hardness, and workability are not sufficient, and if it exceeds 50 parts by weight, the viscosity of the resin composition increases and the workability deteriorates. Sex tends to decrease. (B) Polyester resin has an average molecular weight of 1000 to 3
It is preferably 0000. Average molecular weight is 1000
If the average molecular weight is more than 30,000, the compatibility with the epoxy compound tends to be poor and the adhesiveness tends to decrease.

The polybasic acids include adipic acid, isophthalic acid, terephthalic acid, phthalic acid, hydrogenated phthalic acid, sebacic acid, trimellitic acid, naphthalenedicarboxylic acid,
Typical examples include fumaric acid, maleic acid, and itaconic acid. As the polyhydric alcohols, ethylene glycol, propylene glycol, butylene glycol,
1,6-hexanediol, 1,4-butanediol,
Neopentyl glycol, diethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol,
Typical examples are bisphenol A ethylene oxide adducts and bisphenol A propylene oxide adducts.

As commercially available polyester resins, Toyobo Byron (trade name) series (manufactured by Toyobo Co., Ltd.) such as Byron 103, 200, 220, 300, 500, 5 is used.
60, 600, 610 and Byron GK130, Vitel (trade name) series (manufactured by Goodyear), such as Vitel PE-200, 207.

The (C) photocationic polymerization initiator is an initiator which releases a substance which initiates cationic polymerization upon irradiation with ultraviolet rays, and (A) 1 to 15 parts by weight per 100 parts by weight of an epoxy compound which is liquid at room temperature. , Preferably 5 to 10 parts by weight. By blending in this range, adhesion to plastic film and metal,
A cured coating film having good coating hardness and workability can be obtained. (C) As the photocationic polymerization initiator, an aryldiazonium salt (for example, PP-33 (manufactured by Asahi Denka Kogyo Co., Ltd.)), an aryliodonium salt, an arylsulfonium salt (for example, FC-509 (manufactured by 3M Co.), UVE10).
14 (manufactured by GE), UVI-6974, UVI-6.
970, UVI-6990, UVI-6950 (made by Union Carbide Co.), SP-170, SP-150.
(Manufactured by Asahi Denka Kogyo Co., Ltd.), allene-ion complex (for example,
CG-24-61 (made by Ciba-Geigy) is mentioned.

The isocyanuric ring compound (D) having an acryloyl group and / or a methacryloyl group is a compound having both an isocyanuric ring and at least one acryloyl group or methacryloyl group as a radically polymerizable group in the molecule. The acryloyl group and / or the methacryloyl group may be directly bonded to the isocyanuric ring or may be indirectly bonded through another arbitrary group.

[0016]

These can be used alone or in combination of two or more in the composition of the present invention.
It is used in an amount of 50 parts by weight, preferably 5 to 15 parts by weight. If the amount is less than 1 part by weight, sufficient coating film hardness cannot be obtained,
If it exceeds 50 parts by weight, the adhesiveness and workability are deteriorated. The compound can be easily polymerized or cross-linked to form a coating film by allowing it to coexist with a substance that generates a radical upon irradiation with ultraviolet rays and irradiating with ultraviolet rays.

The isocyanuric ring compounds having an acryloyl group and / or a methacryloyl group include isocyanuric acrylate and isocyanuric methacrylate (for example, Aronix M-215, M-315, M-32).
5 (manufactured by Toagosei Chemical Industry Co., Ltd.)).

The photoradical polymerization initiator (E) is an initiator which releases a substance which initiates radical polymerization upon irradiation with ultraviolet rays, and (D) a heterocyclic compound having an acryloyl group and / or a methacryloyl group and / or an inorganic compound. The amount is 1 to 15 parts by weight, preferably 3 to 10 parts by weight, based on 100 parts by weight of the cyclic compound. By blending in this range, it is possible to obtain a cured coating film having good adhesion to plastic films and metals, coating film hardness, and workability. (E) Photo-radical polymerization initiators are roughly classified into self-cleaving type typified by acetophenone type, benzoin ether type and ketal type and hydrogen abstraction type typified by benzophenone type, benzyl type and thioxanthone type. To be done.

Examples of the self-cleaving type initiator include IRGACURE 907, IRGACURE 369, IRGACURE 184 (manufactured by Ciba-Gaiki), KAYACURE.
Examples include BDMK (manufactured by Nippon Kayaku Co., Ltd.) and Darocur 1173 (manufactured by Merck). Examples of the hydrogen abstraction type initiator include KAYACURE BP-100 and KA.
YACURE DETX-S (manufactured by Nippon Kayaku Co., Ltd.), Irgacure 651 (manufactured by Ciba Geigy), benzyl (manufactured by Kurogane Kasei) and the like can be mentioned.

The ultraviolet-curable resin composition containing the above-mentioned components (A) to (E) of the present invention can be added to an organic or inorganic pigment, an extender pigment, an antifoaming agent, a leveling agent, a slipping agent, etc. within a range not impairing the purpose. A coating material can be obtained by blending the above-mentioned additive for paints.

The ultraviolet curable resin composition of the present invention and the coating agent containing the same are made of polyethylene terephthalate (PE
T) film, polyethylene naphthalate (PEN) film, nylon film, vinyl chloride film, vinylidene chloride film and other plastic films, iron, aluminum, plated steel plates, tin-free steel, stainless steel, and other metal surfaces, ordinary coating Methods such as roll coating, gravure coating, gravure offset coating, curtain flow coating, reverse coating, screen printing, spraying and dipping can be applied. The film thickness of the cured coating varies depending on the application, but is 0.5-
A range of about 50 μ, preferably about 1 to 20 μ is suitable.

As a light source for curing the ultraviolet-curable resin composition of the present invention and a coating material containing the same, a light source containing a light having a wavelength of 200 to 450 nm is usually used.
For example, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a xenon lamp, a carbon arc lamp or the like can be used.

[0024]

[Example 1]

3,4-Epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate ("UVR-6110" manufactured by Union Carbide) 65 parts Polyester resin 19 parts ("Byron 300" manufactured by Toyobo Co., Ltd., molecular weight 15000-20000) Light Cationic polymerization initiator ("UVI-6990" manufactured by Union Carbide) 6 parts 2,4-bis (acryloxyethyl) -6-ethanol isocyanurate 10 parts ("Aronix M-215" manufactured by Toagosei Co., Ltd.) Radical polymerization initiator (“Darocur 1173” manufactured by Merck Co., Ltd.) 0.5 part Surfactant (“L-7604” manufactured by Nippon Unicar Co., Ltd.) 0.4 part was mixed and stirred to prepare coating material 1. This is thickness 30
It was coated on a 0 μm aluminum plate and a 100 μm PET film to a thickness of 7 μm,
The coating was cured by passing it under one W / cm high-pressure mercury lamp at a speed of 5 m / min.

Example 2 3,4-Epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate (“UVR-6110” manufactured by Union Carbide) 62 parts Polyester resin 22 parts (“Byron 220 manufactured by Toyobo Co., Ltd.”) , Molecular weight 2000-3000) Photocationic polymerization initiator (“UVI-6950” manufactured by Union Carbide) 6 parts Tris (acryloxyethyl) isocyanurate 10 parts (“Aronix M-315” manufactured by Toagosei Co., Ltd.) Radical polymerization initiator (“Irgacure 184” manufactured by Ciba-Geigy) 0.5 part Surfactant (“L-7604” manufactured by Nippon Unicar Co., Ltd.) 0.4 part was mixed, and paint 2 was prepared in the same manner as in Example 1. It was prepared and applied on an aluminum plate and a PET film to cure the coating film.

Example 3 Instead of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, bis- (3,4-epoxycyclohexyl) adipate ("U" manufactured by Union Carbide Co.) was used.
A coating material 3 was prepared in the same manner as in Example 2 except that VR-6199 ") was used, and the coating material 3 was applied onto an aluminum plate and a PET film to cure the coating film.

Example 4 The procedure of Example 2 was repeated except that a phosphazene-based curable resin (“PPZ-N1000” manufactured by Idemitsu Petrochemical Co., Ltd.) was used instead of tris (acryloxyethyl) isocyanurate. Make paint 4,
It was applied on an aluminum plate and a PET film to cure the coating film.

Example 5 Except that 10 parts of 65 parts of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate were replaced with cresol novolac epoxy resin (“DEN431” manufactured by Dow Chemical Co.). A coating material 5 was prepared in the same manner as in Example 2 and applied on an aluminum plate and a PET film,
The coating was cured.

Comparative Example 1 A coating material 6 was prepared in the same manner as in Example 1 except that 2,4-bis (acryloxyethyl) -6-ethanol isocyanurate and a photoradical polymerization initiator were omitted. It was applied on a plate and PET film and the coating was cured.

[Comparative Example 2] A coating material 7 was prepared in the same manner as in Example 2 except that tris (acryloxyethyl) isocyanurate and the photoradical polymerization initiator were omitted, and the coating material 7 was applied onto an aluminum plate and a PET film. , The coating was cured.

Comparative Example 3 A coating material 8 was prepared in the same manner as in Example 2 except that bisphenol A diglycidyl ether was used instead of tris (acryloxyethyl) isocyanurate, and the coating material 8 was formed on an aluminum plate and a PET film. Was applied to cure the coating film.

Comparative Example 4 Example 2 was repeated except that hydrogenated dicyclopentadienyl diacrylate was used instead of tris (acryloxyethyl) isocyanurate.
Paint material 9 is prepared in the same manner as above, and an aluminum plate and P
It was applied onto an ET film and the coating film was cured.

The adhesion, pencil hardness and workability of the coating films obtained in Examples 1 to 5 and Comparative Examples 1 to 3 were evaluated. The results are shown in Table 1. The evaluation was performed as follows. (1) Adhesion (evaluated by the coating film applied to the PET film) Based on JIS K5400, 100 goggles and a cellophane tape peeling test were performed to show the number of goggles where the paint did not peel off. (2) Pencil hardness (Evaluated by the coating film applied to the PET film and the coating film applied to the aluminum plate) Based on JIS K5400, Mitsubishi pencil "Uni" at room temperature
The maximum hardness that the coating film peeled off and did not reach the base was displayed. (3) Workability (Evaluated by the coating film applied to the aluminum plate) Using a 1/2 inch rod in a DuPont impact tester,
A weight of 500 g was dropped from a height of 50 cm from the back side (aluminum plate side) of the coating film surface, and cracks generated in the coating film were visually evaluated. ⊚: No abnormality. ○: Some cracks occurred. Δ: Many cracks occurred. X: Cracks were generated on the entire surface.

[0034]

[Table 1]

[0035]

According to the present invention, an ultraviolet curable resin composition suitable for vehicles such as varnishes, paints and inks was obtained. The coating film obtained from the ultraviolet curable resin composition of the present invention and the coating material containing the same has excellent adhesion to plastic films and metals, and also has good surface hardness and processability.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI G03F 7/032 501 G03F 7/032 501 (56) Reference JP-A-6-228413 (JP, A) JP-A-5-186755 (JP, A) JP-A-2-1958 (JP, A) JP-A-4-261489 (JP, A) JP-A-60-127321 (JP, A) JP-B 2-30326 (JP, B2) (JP-A) 58) Fields investigated (Int.Cl. ⁷ , DB name) C08L 63/00-63/10 C08G 59/18 C08G 59/40 C09D 163/00-163/10 G03F 7/027-7/032

Claims (3)

(57) [Claims] 1. An epoxy compound which is liquid at room temperature (A) 4
0 to 90 parts by weight, (B) polyester resin 5 to 50 parts by weight, (C) photocationic polymerization initiator to 1 to 15 parts by weight with respect to (A) 100 parts by weight, (D) acryloyl group and / or methacryloyl. Isocyanuric cyclizations with groups
1 to 50 parts by weight of the product, and 1 to 15 parts by weight of (E) a photoradical polymerization initiator relative to 100 parts by weight of (D), an ultraviolet-curable resin composition. 2. The ultraviolet curable resin composition according to claim 1, wherein the epoxy compound which is liquid at room temperature contains at least 50% by weight of an alicyclic epoxy compound. 3. A coating agent including the claims 1 or 2 UV-curable resin composition.