JPH0645776B2 - Active energy ray curable coating composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to an active energy ray-curable coating composition, and more specifically, to an extremely short time by an active energy ray such as an ultraviolet ray or an electron beam. The present invention relates to a novel coating composition that cures and gives a cured product excellent in paintability, adhesion to a base material, coating film physical properties, and the like.

[Conventional technology]

Conventionally, active energy ray curable paints have been extensively researched from the viewpoint of energy saving and space saving, but as compared with the current solvent type baking paint, the adhesion to the base material,
It cannot be said that the coating film physical properties such as coating film hardness and molding processability are necessarily the same, especially when the base material is a metal, there is still no paint that has good adhesiveness and can withstand coating process. The reality is that they have not been found.

[Problems to be solved by the invention]

The present invention intends to provide an active energy ray-curable coating composition that exhibits excellent adhesion to a metal can made of a metal plate such as an aluminum plate, various treated steel plates, and a copper plate, and has excellent coating film physical properties. It is a thing.

Structure of the Invention [Means for Solving Problems] That is, the present invention comprises (a) a monomer represented by the following general formula [I] and optionally a monomer having at least one vinyl group. Resin obtained by polymerization or copolymerization (However, R1 is a hydrogen atom or an alkyl group, R2 is an alkylene group or a substituted alkylene group, R3 is a hydrogen atom or a methyl group. N is 0 or an integer of 1 or more.) (B) In one molecule A compound having one or more epoxy groups (c) An active energy ray-curable coating composition comprising a polymerization initiator capable of initiating the polymerization of the compound (b) by irradiation with an active energy ray. is there.

As the monomer represented by the general formula [I] used in the present invention, an acrylate of an ethylene oxide adduct of phenol (commercially available, light ester PO-A manufactured by Kyoeisha Oil & Fat Co., Ltd., Toagosei Co., Ltd.) Aronix M-10
1, M-102, etc.), acrylate of ethylene oxide adduct of p-nonylphenol (Aronix M-111, M-113, etc. manufactured by Toagosei Co., Ltd. as commercial products)
Acrylate of propylene oxide adduct of p-nonylphenol (Aronix M-117 manufactured by Toagosei Co., Ltd. as a commercial product, Light Ester M manufactured by Kyoeisha Yushi Co., Ltd.)
P-2PA, etc.), phenyl glycidyl ether acrylate, (Aronix M-5700 etc. manufactured by Toagosei Co., Ltd. as a commercial product) and the like.

In addition, one vinyl group is included in the molecule that can be copolymerized with the above monomers.
Any monomer can be used as the monomer having at least one, as long as it is an ordinary acrylic monomer, for example, (meth) acrylic acid, methyl methacrylate, ethyl (meth) acrylate,
Butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, stearyl (meth) acrylate, maleic acid, styrene, acrylonitrile, Vinyl acetate, acrylamide, N-
Methylol acrylamide, glycidyl methacrylate, cyclohexyl (meth) acrylate, 2- (meth)
Acryloyloxyethyl phthalic acid, mono (2- (meth) acryloyloxyethyl) acid phosphate, tetrahydrofurfuryl (meth) acrylate, polyoxyalkylene glycol di (meth) acrylate such as polyethylene glycol di (meth) acrylate Can be mentioned.

The proportion of the monomer represented by the general formula [I] (a) in the resin is 20% by weight or more in the resin (a), preferably 40% by weight.
It is more than weight%.

The homopolymerization or copolymerization of the monomer represented by the general formula [I] may be carried out by an ordinary radical polymerization method, preferably solution polymerization. If the solvent used for this polymerization is required in the coating composition. If not, the solvent may be removed under reduced pressure or the like. The resin (a) thus obtained is preferably incorporated in the coating composition in an amount of 5 to 70% by weight, particularly 5 to 30% by weight.
% Range is preferred. If it is less than 5% by weight, the adhesiveness to the substrate, especially to the metal substrate cannot be exhibited.
When it is blended in an amount of 0% by weight or more, the hardness of the coating film is lowered and the coating film has no practical physical properties.

Further, the epoxy compound used in the present invention having one or more epoxy groups in one molecule may be any ordinary epoxy composition, for example, bisphenol A diglycidyl ether, bisphenol A di-β. Methyl glycidyl ether, bisphenol F diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, diglycidyl ether of bisphenol A alkylene oxide adduct, novolak glycidyl ether,
Polyalkylene glycol diglycidyl ether, glycidyl ether type epoxy resin such as epoxy urethane resin, diglycidyl ester of dibasic acid such as adipic acid diglycidyl ester, phthalic acid diglycidyl ester, monoglycidyl ester of higher fatty acid, diglycidyl dimer acid Glycidyl ester type epoxy resin such as ester, glycidyl amine type epoxy resin such as triglycidyl isocyanurate, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, vinylcyclohexenedioxide, 2-
(3,4-epoxycyclohexyl-5,5-spiro-
3,4-Evoxy) cyclohexane-meta-dioxide, alicyclic epoxy resin such as bis (3,4-epoxycyclohexyl (adipate), 1,4 butanediol diglycidyl ether, 1,6 hexanediol diglycidyl ether, glycerin Polyglycidyl ethers of aliphatic polyhydric alcohols such as triglycidyl ethers of triglycidyl ethers, triglycidyl ethers of trimethylolpropane, diglycidyl ethers of polyethylene glycol, diglycidyl ethers of polypropylene glycol, etc. Obtained polyglycidyl ether of polyether polyol, epoxidized polybutadiene, epoxidized soybean oil, monoglycidyl ether of higher aliphatic alcohol, phenol,
Examples thereof include resorcinol, t-butylphenol, and monoglycidyl ether-containing heterocyclic epoxy resins of polyether alcohol obtained by adding alkylene oxide to these, spiro ring-containing epoxy resins, and the like.

Epoxy resins used in the present invention include glycidyl ether type epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, aliphatic epoxy resins, alicyclic epoxy resins, heterocyclic epoxy resins, and spiro ring-containing compounds. One or two or more kinds of epoxy resins and the like may be appropriately blended according to the required performance. From the viewpoint of internal curability, adhesiveness, etc., a particularly preferable epoxy resin composition is mainly composed of an alicyclic epoxy resin. It is what

If necessary, the epoxy resin composition used in the present invention may contain a cationic polymerizable compound such as vinyl compounds, caprolactone, vinyl ethers and polyester resins.

Further, the present invention uses the polymerization initiator as an epoxy compound by releasing a cation upon irradiation with an active energy ray.
It is capable of initiating the polymerization of (b), and is a triallyl sulfolium salt (FC50 manufactured by 3M as a commercial product).
8. UVE-1014 from General Electric Company
Etc.), triallyldiazonium salt (SP-33 etc. of American Can Co. as a commercial product), metal onium salt (SP-150 etc. of Asahi Denka Co., Ltd. as a commercial product), peroxysilyl group-containing silicon compound or aluminum compound. Etc.

These polymerization initiators may be added in an appropriate amount according to the coating composition and the required curing rate. In the present invention, the polymerization initiator is added to 100 parts by weight of the resin component in the coating composition.
It is suitable to add 0.1 to 10 parts by weight. If the amount of the polymerization initiator is less than 0.1 parts by weight, a sufficiently cured coating film cannot be obtained, and even if it is blended in an amount of 10 parts by weight or more, no improvement in the curing speed is observed, and conversely yellowing of the coating film, paint Problems such as price increase and odor of decomposition products occur.

Further, the active energy ray-curable coating composition of the present invention comprises
If necessary, various resins and additives may be added in order to improve adhesion to the base material, coating film properties, and coating properties such as defoaming property, smoothness and lubricity. For example,
Acrylic resin, alkyd resin, oil-free alkyd resin, phenol resin, olefin resin, vinyl resin,
Butyral resins, caprolactone-modified resins, polyhydric alcohols, acid anhydrides, dyes and pigments, and paintability improving additives.

Further, in order to adjust the viscosity of the paint to an appropriate viscosity for easy coating, an appropriate amount of an organic solvent can be blended within a range that does not deteriorate the curability and the physical properties of the coating film.

Further, the active energy ray-curable coating composition used in the present invention is a compound capable of radical reaction having a (meth) acrylic group, an allyl group, a vinyl group and the like, and an aryl capable of initiating radical polymerization by active energy rays. -By blending a ketone sensitizer or the like, curability and coating film performance can be improved.

The active energy rays used in the present invention include low pressure mercury lamps, medium and high pressure mercury lamps, metal halide lamps,
There are radiations such as ultraviolet rays emitted from carbon arc lamps and xenon lamps, electron rays, and γ-rays. Any of these can be used depending on the application, but of these, the medium and high pressure mercury lamps and metal halide lamps are particularly preferably used.

The active energy ray-curable coating composition of the present invention can be used on various kinds of commonly used base materials without any problem. Further, the cured coating film exhibits excellent adhesion to the base material. The base material used here is, for example, a metal plate such as an aluminum plate, a chromate-treated steel plate, a nickel-treated steel plate, a copper plate, or a tin-plated steel plate, or an alkyd resin, a modified alkyd resin, an eponester resin, or a modified metal plate on these metal plates. Eponester resin,
Oil-free alkyd resin, polyester resin, vinyl resin, modified vinyl resin, acrylic resin, polyamide resin, urethane resin, phenol resin, urea resin,
Paints obtained by applying paints using resins such as amino resins or paints in which dyes and pigments are dispersed, and molded products thereof, or those printed on these painted plates or molded products,
Examples thereof include paper and printing paper, plastic films such as polyester, polyolefin, polyvinyl chloride and the like, molded products thereof, and those obtained by printing these plastic films and molded products.

Further, the active energy ray-curable coating composition of the present invention can be applied to a base material by a method commonly used. For example, a coating method such as a roll coater, a flow coater, a curtain flow coater, a gravure coater, a screen coater, or a spray can be used.
Further, the cured film thickness of the coating film is in the range of about 0.5 to 100 μ, but is usually preferably in the range of 1 to 10 μ.

In addition, in this coating, in order to improve the adhesion to the base material and the coating properties such as cissing, the metal plate should be cleaned with an organic solvent, corona discharge treatment, cathodic electrolysis treatment, heat treatment with an oven, etc. You can Among these, when performing heat treatment with an oven, etc.,
The heating is carried out at 100 to 250 ° C. for about 30 seconds to 20 minutes, but is usually heated at 150 to 210 ° C. for 5 to 10 minutes.

Further, in order to improve the smoothness of the coating film, the adhesion to the base material, the coating film hardness, and the molding processability, after coating the coating composition of the present invention, before or after irradiation with active energy rays, or any of these. You can heat the crab. However, in the case of heating before irradiating with active energy rays, it is necessary that the gloss of the cured coating film is within a range that does not significantly decrease. That is, in this case, 3 at 40 to 60 ° C
A range of up to 15 seconds is preferred. In addition, heating after curing with active energy rays is particularly effective in improving adhesion, coating film hardness, moldability, hot water resistance, and winding tightening resistance. In this case, the heating condition is preferably 160 to 220 ° C. and 1 to 20 minutes, more preferably 150 to 180 ° C. and 3 to 10 minutes.

〔Example〕

 The present invention will be specifically described by the following examples.

Minutes in the examples represent parts by weight.

Synthesis Example 1 200 parts of methyl isobutyl ketone was placed in a flask equipped with a stirrer, a thermometer, and a water-cooled condenser, and heated to 100 ° C. in a nitrogen atmosphere. A mixture of 180 parts of phenyl glycol monoacrylate (Kyoeisha Oil and Fat Co., Ltd. product name light ester PO-A), 20 parts of butyl alcohol, and 2 parts of benzoyl peroxide was added dropwise to the mixture while stirring for 2 hours. 1 hour after the end of dropping, benzoyl peroxide
The reaction was terminated by adding 0.2 part and maintaining for another hour.
Thus, an acrylic resin A having a nonvolatile content of 50% was obtained.

Synthesis Example 2 200 parts of methyl isobutyl ketone was placed in one flask equipped with a stirrer, a thermometer, and a water-cooled condenser, and heated to 100 ° C. in a nitrogen atmosphere. To this, a mixture of 200 parts of acrylate of propylene oxide adduct of p-nonylphenol (Aronix M-117 manufactured by Toagosei Co., Ltd.) and 2 parts of benzoyl peroxide was added dropwise over 2 hours while stirring. 1 hour after the end of the dropping, benzoyl peroxide 0.
The reaction was terminated by adding 2 parts and holding for 1 hour.
Thus, an acrylic resin B having a nonvolatile content of 50% was obtained.

Synthesis Example 3 200 parts of methyl isobutyl ketone was placed in one flask equipped with a stirrer, a thermometer, and a water-cooled condenser, and heated to 100 ° C. in a nitrogen atmosphere. A mixture of 100 parts of phenyl glycidyl ether acrylate (trade name: Aronix M-5700 manufactured by Toagosei Co., Ltd.), 100 parts of styrene, and 2 parts of benzoyl peroxide was added dropwise to the mixture while stirring for 2 hours. 1 hour after the end of the dropping, benzoyl peroxide 0.
The reaction was terminated by adding 2 parts and holding for 1 hour.
Thus, an acrylic resin C having a nonvolatile content of 50% was obtained.

Synthesis Example 4 Synthesis was carried out in the same manner as in Synthesis Example 3, except that tripropylene glycol acrylate was used in place of the phenyl glycidyl ether acrylate.
0% acrylic resin D was obtained.

Examples 1 to 6 Paints were produced with the compositions shown in Table 1 using the acrylic resins obtained in Synthesis Examples 1 to 4. The numbers in the table represent the nonvolatile content ratio.

The paints shown in the examples of Table 1 were applied to various metal plates and paint-coated plates so that the film thickness would be 6μ, and a high pressure mercury lamp (output 80 W / cm) was irradiated from a height of 10 cm for 0.5 seconds to apply the paint. Activated membrane.

Table 2 shows the physical property test results for Examples 1 to 6.

The test method and evaluation method were as follows.

1) Adhesion Adherence is based on JIS K-5400.8.5.2 base tape method, and is shown by the coating film residual rate.

2) Pencil hardness JIS K-5400.8.4.2 Compliant with the hand scraping method 3) Haze fold 1T 4 cm x 6 cm test coated plate with the coated side facing outward and the long side of 2
Fold it in half, sandwich an ET (electric tin-plated iron plate) plate of 0.24 mm in between, drop a load of 5 kg from the top, and perform impact bending.

The state of cracks in the coating film at the bent portion is visually determined.

Evaluation ◯: No crack is generated at all.

Δ: Cracks are formed in a mesh shape.

X: The coating film is completely peeled off.

4) Put the retort test coated plate in a high-pressure sterilization kettle and use steam at 130 ° C for 3
Heat treatment for 0 minutes.

Evaluation ◯: No whitening or blistering of the coating film occurs.

△: Whitening, blistering of the coating film is about 50% of the area of the test coated plate
Occurs in.

X: Whitening and blistering of the coating film occur on the entire surface of the test coated plate.

5) Tightening resistance A lid for a flat No. 2 can (diameter 83 mm × height 51 mm can for fish meat can) is punched out with a press machine with the coated surface facing outside, and this is put on the body of the flat No. 2 can and rolled. Double-tightening is performed using a tightening machine.

Evaluation ◯: No crack occurs in the coating film on the wound portion.

Δ: Network-like cracks in the coating film at the winding portion occur.

X: The coating film of the winding fastening portion is peeled off over the entire surface.

6) Scratch resistance Based on JIS K-5400.8.4.2 pencil hardness hand-shaking method, when scratching the surface with a Mitsubishi Pencil Uni 4H pencil, the state of scratches on the coating film surface is visually evaluated. To do.

In the tests 2) to 6), a TFS plate was used as the base.

As a comparative example, a coating material having the composition shown in Table 3 was manufactured. The numbers in the table represent the nonvolatile content ratio.

The coating material shown in the comparative example in Table 3 was irradiated with ultraviolet rays in the same manner as in the example to cure the coating film. Table 4 shows the results of the physical property tests of Comparative Examples.

EFFECTS OF THE INVENTION The active energy ray-curable coating composition of the present invention has good adhesion to a substrate and excellent coating film hardness and molding processability. In particular, when the base is a metal, the conventional paint does not show practical adhesion, but the paint of the present invention is remarkably improved in adhesion to metal due to the addition of a resin containing a specific monomer. . For this reason, the coating material of the present invention can form a coating having excellent coating film physical properties not only on the metal but also on the ground such as painted metal, plastic film, and paper.

Claims (1)

[Claims] 1. A resin obtained by polymerizing or copolymerizing (a) a monomer represented by the following general formula [1] and optionally a monomer having one or more vinyl groups. (However, R ₁ is a hydrogen atom or an alkyl group, R ₂ is an alkylene group or a substituted alkylene group, R ₃ is a hydrogen atom or a methyl group. N is 0 or an integer of 1 or more.) (B) One molecule Compound having one or more epoxy groups therein (c) Active energy ray curing for metal can comprising a polymerization initiator capable of initiating polymerization of the compound (b) by irradiation with active energy ray Coating composition.