JPH0230326B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cationic polymerizable liquid energy ray-curable resin composition, which contains an epoxy resin, a thermoplastic saturated polyester resin, and a photopolymerization initiator as essential components. The present invention relates to a cationic polymerizable energy ray-curable resin composition that provides a strong coating film with excellent adhesion, flexibility, impact resistance, and the like.

BACKGROUND ART Resin compositions curable with energy rays such as ultraviolet rays or electron beams have attracted attention from the viewpoint of energy saving, resource saving, space saving, and pollution control, and active research and development is being carried out in the fields of inks, paints, and varnishes. Along with this, demands on coating film performance have also increased.
In the field of paints, there is a demand for energy ray-curable resin compositions that have coating performance equivalent to or better than conventional solvent-based paints, but such compositions have not always been satisfactory.

The present inventors have conducted various studies regarding energy ray curable resin compositions in order to produce a cationic polymerization type energy ray curable resin composition that provides a strong coating film with adhesion and flexibility to substrates. As a result, the inventors found that an epoxy resin composition containing a thermoplastic saturated polyester resin provided an excellent cured coating film, and completed the present invention.

The purpose of the present invention is to create a cationically polymerized liquid energy ray-curable resin composition that provides a strong coating film with excellent coating properties, particularly excellent adhesion to various substrates, flexibility, impact resistance, and durability. It's about providing things. Specifically, the object of the present invention is to provide a cationic polymerizable energy ray-curable resin composition particularly suitable for varnishes, paints, ink vehicles, coatings, and the like.

The cationically polymerized liquid energy ray-curable resin composition of the present invention includes (a) one or more epoxy resins that are liquid at room temperature and have at least one or more epoxy groups in one molecule; 60 to 95 parts by weight, (b) 5 to 40 parts by weight of a thermoplastic saturated polyester resin having an average molecular weight of 2,500 to 30,000, and (c) a photopolymerization initiator that releases a substance that initiates cationic polymerization upon irradiation with energy rays; ) and (b) in an amount of 0.1 to 10 parts by weight per 100 parts by weight of the mixture.

First, 1 is the main component of the composition of the present invention.
Epoxy resin (a), which is liquid at room temperature and has at least one epoxy group in its molecule, is a conventionally known epoxy resin that is polymerized or crosslinked by energy ray irradiation in the presence of a photopolymerization initiator to form a coating film. Examples of the epoxy resin used in the epoxy resin composition include conventionally known aromatic epoxy resins, alicyclic epoxy resins, and aliphatic epoxy resins. Here, preferred aromatic epoxy resins are polyglycidyl ethers of polyhydric phenols or their alkylene oxide adducts having at least one aromatic nucleus, such as bisphenol A or its alkylene oxide adducts and epichlorohydrin. Examples include glycidyl ether and epoxy novolac resin produced by the reaction of In addition, as the alicyclic epoxy resin, at least 1
Cyclohexene oxide or cyclopentene oxide-containing compound obtained by epoxidizing a polyglycidyl ether of a polyhydric alcohol having 2 alicyclic rings or a cyclohexene or cyclopentene ring-containing compound with an appropriate oxidizing agent such as hydrogen peroxide or peracid. can be mentioned. A typical example of a polyglycidyl ether of a polyhydric alcohol having at least one alicyclic ring is a glycidyl ether produced by reacting hydrogenated bisphenol A or its alkylene oxide adduct with epichlorohydrin. Further, representative examples of cyclohexene oxide or cyclopentene oxide-containing compounds include those represented by the following formula.

Preferred aliphatic epoxy resins include polyglycidyl ethers of aliphatic polyhydric alcohols or their alkylene oxide adducts, polyglycidyl esters of aliphatic long-chain polybasic acids, and homopolymers and copolymers of glycidyl acrylate and glycidyl methacrylate. Typical examples include diglycidyl ether of 1,4-butanediol, diglycidyl ether of 1,6-hexanediol, triglycidyl ether of glycerin, triglycidyl ether of trimethylolpropane, diglycidyl ether of polyethylene glycol, and polypropylene glycol. Polyglycidyl ether of polyether polyol obtained by adding one or more alkylene oxides (ethylene oxide, propylene oxide) to aliphatic polyhydric alcohol such as diglycidyl ether, ethylene glycol, propylene glycol, and glycerin. , diglycidyl esters of aliphatic long chain dibasic acids. Furthermore, monoglycidyl ethers of aliphatic higher alcohols, phenols, cresols, butylphenols, monoglycidyl ethers of polyether alcohols obtained by adding alkylene oxide to these, glycidyl esters of higher fatty acids, etc. may be blended as diluents. can.

The epoxy resin composition used in the present invention can contain these aromatic epoxy resins, alicyclic epoxy resins, or aliphatic epoxy resins alone or in a wide variety of combinations depending on the desired performance. A particularly preferable epoxy resin composition from the viewpoint of adhesion to the base material is one mainly composed of an alicyclic epoxy resin, and a cyclohexene oxide or cyclopentene oxide-containing compound as mentioned above is used as an epoxy resin composition. Alicyclic epoxy resin having an epoxy group [for example, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, bis(3,4-epoxycyclohexylmethyl)adipate] is preferably 20 to 95% by weight. those within the range of
More preferably, the content is 50 to 90% by weight.

In addition to the above-mentioned epoxy resins, cationic polymerizable compounds such as cyclic ethers, vinyl ethers, lactones, and vinyl compounds can also be used as constituent components of the epoxy resin composition used in the present invention.

An essential component of the cationic polymerizable energy beam curable resin composition of the present invention, which has an average molecular weight of 2500 to
30000 thermoplastic saturated polyester resin is a linear saturated polyester resin having thermoplasticity obtained by the reaction of organic acids or their esters with alcohols. Examples of raw organic acids include adipic acid, isophthalic acid, terephthalic acid, phthalic acid, hydrogenated or chlorinated phthalic acid, sepacic acid, trimellitic acid, aliphatic acid, dimer acid, etc., and alcohols include diethylene glycol. Typical examples include butylene glycol, ethylene glycol, neopentyl glycol, dipropylene glycol, propylene glycol, polypropylene glycol, polyethylene glycol, and the like.

The thermoplastic saturated polyester resin that can be used in the present invention has an average molecular weight within the range of 2,500 to 30,000, preferably an average molecular weight of 5,000.
~25,000, and if the average molecular weight is less than 2,500, there will be little effect on flexibility and adhesion.On the other hand, if the average molecular weight exceeds 30,000, the compatibility with epoxy resin etc. will decrease and the adhesion will be improved. is not effective enough.

Useful commercially available thermoplastic saturated polyester resins include the Toyobo Vylon (trade name) series (commercially available from Toyobo Co., Ltd.), such as Vylon 103, 200,
300, 500, 560, 600, 630 and Byron GK130,
Further examples include the Vitel (trade name) series (commercially available from Guttoyer), such as Vitel PE-200 and 207.

The amount of thermoplastic polyester resin as an essential component can be varied widely depending on the required performance, but generally it is in the range of 5 to 40 parts by weight per 100 parts by weight of the resin content of the composition of the present invention. If the content is less than 5 parts by weight, no blending effect will be obtained, and if it is more than 40 parts by weight, not only will the viscosity of the composition of the present invention increase significantly, but the inherent performance of the energy beam cured coating will deteriorate. A particularly preferred amount is 5 to 30 parts by weight.

Among these thermoplastic saturated polyester resins, those having a hydroxyl group or a carboxyl group at the end of the molecular chain are particularly effective in improving adhesiveness.

On the other hand, the photopolymerization initiator used in the present invention that releases a substance that initiates cationic polymerization upon irradiation with energy rays is not particularly limited, but particularly preferred is an onium salt that releases a Lewis acid capable of initiating polymerization upon irradiation. It belongs to a group of double salts. Such a photopolymerization initiator basically has the general formula [R ¹ _a R ² _b R ³ _c R ⁴ _d Z] ^+m [MX _o+n ] ^-m [wherein the cation is onium and Z is N≡
N, S, Se, Te, P, As, Sb, Bi, O, halogen (for example I, Br, Cl), R ¹ , R ² ,
R ³ and R ⁴ are organic groups which may be the same or different. a, b, c, and d are each integers of 0 to 3, and a+b+c+d is equal to the valence of Z. M
is a metal or metalloid that is the central atom of the halide complex, and B, P, As, Sb,
Fe, Sn, Bi, Al, Ca, In, Ti, Zn, Sc, V,
Cr, Mn, Co, etc. X is halogen, m
is the net charge of the halide complex ion,
n is the number of halogen atoms in the halide complex ion. ].

Such photopolymerization initiators are known per se; for example, diazonium compounds in which Z is N≡N are disclosed in U.S. Pat.
It is described in No. 3794576 etc. Other onium-based photopolymerization initiators are described in Belgian Patent No. 828841, Belgian Patent No. 828669, French Patent No. 2270269, and the like.

The above diazonium compounds are described in the above US patents.
It can be obtained by the method described in No. 3708296, No. 3949143, etc. Compounds in which Z is S, Se, Te, J. Knapozyk et al., JACS, 91 , 145
(1969), AL Maycock et al. J. Organic
Chemistry, 35 , No. 8, 2532 (1970), Goethals et al., Bul.Soc.Chim.Belg., 73 , 546 (1964), HM
It can be produced by the method described in Leicestar et al., JACS, 51 , 3587 (1929). Z is P, N, As,
Representative onium salts such as Sb and Bi are J. Goerdeler
Methoden der Organishen Chimie, 11/12 ,
591-640 (1958), K. Sasse's 12/1, 79-112
(1963). A typical onium salt where Z is halogen is OAPtitsyna
Dokl.Adad.Nauk., SSSR, 163 , 383
(1965), M. Drexler et al. JACS, 75 , 2705
(1953) and others. Furthermore, the onium salts referred to herein include pyrylium salts such as thiopyrylium described in U.S. Patent No. 4139655, and oxonium salts such as aryloxysulfoxonium salts described in JP-A-56-8428. It will be done.

Examples of other compounds that can be used to initiate the polymerization of epoxides are iodoform, α,α-dibromoparaxylene, bromoform, carbon tetrabromide, hexachloroparaxylene, and others described in U.S. Pat. No. 3,895,954. These are catalysts, bis(perfluoroalkylsulfonyl)methane salts, and organic halogen compounds such as diazonium salts of sulfonylmethane as described in US Pat. No. 3,586,616, German Patent No. 2,419,274, and the like.

These photoinitiators have the required curing speed,
It may be added in an appropriate amount depending on the curing method to be applied, and in general, it is preferably 0.1 to 10 parts by weight based on 100 parts by weight of the resin content of the curable composition of the present invention.

In addition, if necessary, the energy ray-curable resin composition of the present invention may contain olefins other than the cationically polymerizable substances described above in order to improve the properties of the paint or coating film, as long as the effects of the present invention are not impaired. resins, acrylic resins, petroleum resins, alkyd resins, polyether compounds, polyether polyol compounds, vinyl acetate resins, vinyl chloride resins, butyral resins, rubber resins, vinyl alcohol resins, acid anhydrides It can be used in combination with a physical epoxy resin curing agent, pigments, dyes, and various paint additives.

Furthermore, as proposed in U.S. Pat. No. 4,156,035, the cationic polymerizable resin composition used in the present invention may be blended with an acrylate or methacrylate compound and a carbonyl photosensitizer to improve coating film performance and curing properties. It is also possible to improve.

The energy ray-curable resin composition of the present invention can be applied to the surface of a substrate by a conventional coating method such as a roll coater, gravure coater, gravure offset, flow coating, screen printing, spraying, or dipping method. . that time,
In order to improve paintability and adhesion to the substrate, the surface of the substrate may be pretreated such as alcohol treatment or corona discharge treatment before application, or the resin composition may be applied to the extent that there is no adverse effect such as a decrease in performance. It can be applied by adding an organic solvent to the material. The thickness of the cured coating film is determined by the required performance for the various base materials.
A range of about 0.1 to 20μ is appropriate, preferably 3
It is about ~10μ. Energy rays used to apply the curable resin composition of the present invention to various substrates to form a cured coating film include ultraviolet rays, electron beams, and radiation. Among these, methods using ultraviolet irradiation are practical. This is the most preferable method. Further, coating film formation using the curable composition of the present invention can be carried out after or while heat treating the substrate, or by applying the curable composition to the substrate, followed by heat treatment and energy ray irradiation. It can also be effectively promoted by combining the following. Furthermore, when coating the composition, it is also possible to use an organic solvent to adjust the viscosity within a range that does not cause any adverse effects such as deterioration of the performance of the energy ray-curable resin composition.

By containing an epoxy resin, a thermoplastic saturated polyester resin, and a photopolymerization initiator as essential components, the energy ray-curable resin composition of the present invention can improve the paintability during painting, and at the same time has excellent properties on various substrates. A cured coating film having adhesion, flexibility, impact resistance, durability, etc. can be obtained.

That is, the energy ray-curable resin composition of the present invention is coated and cured on the surface of various base materials, and then subjected to bending processing, molding processing, embossing processing, lamination processing,
It is also possible to perform post-processing such as printing. Furthermore, after performing pretreatment such as corona discharge treatment on the surface of the cured coating, lamination, metal vapor deposition,
Post-processing such as printing is also possible. The curable composition of the present invention can be used, for example, in agricultural films and sheets, vinyl chloride cosmetic films, plastic adhesive films,
Protective paints and finishing paints for various plastic films and sheets such as polyester films for magnetic tapes, films and sheets for vacuum deposition, printed paper such as wrapping paper, folding cartons, and label paper, and various base materials such as metal cans, steel plates, and aluminum foils. It can be used as a coating paint, intermediate coat paint, undercoat paint, ink vehicle, etc.

Hereinafter, representative examples of the energy ray-curable resin composition of the present invention will be described in more detail as examples, but the present invention is not limited to the following examples. In the examples, "parts" means parts by weight.

Example 1 3,4-epoxycyclohexylmethyl-3,
65 parts of 4-epoxycyclohexyl carboxylate (epoxy equivalent: 131-143), 1,4-butanediol diglycidyl ether (epoxy equivalent:
125-143) 20 parts, thermoplastic saturated polyester resin (manufactured by Toyobo Co., Ltd., trade name: Vylon 500, molecular weight
20000-25000) 15 parts, silicone surfactant
An energy beam curable resin composition consisting of 0.5 parts of PP-33 (manufactured by Asahi Denka Kogyo Co., Ltd.) and 3 parts of a photopolymerization initiator was diluted with 20 parts of ethyl acetate solvent to form a polyester film for magnetic tape (12μ thick). ) under a high-pressure mercury lamp (output 80 W/cm, 4 KW) installed at a height of 10 cm.
Ultraviolet rays were irradiated by passing at a speed of 25 m/min to obtain a coated polyester film with excellent coating film smoothness and adhesion. Next, a metal cobalt thin film was formed on the surface of this coating layer by vacuum evaporation. This product had a specular appearance, and no peeling of the deposited film was observed in a cellophane tape peeling test. On the other hand, in the above composition containing no thermoplastic saturated polyester resin, peeling of the film was observed in the cellophane adhesive test against the polyester film.

Example 2 3,4-epoxycyclohexylmethyl-3,
30 parts of 4-epoxycyclohexylcarboxylate (epoxy equivalent: 131-143), bis(3,4-
40 parts of epoxycyclohexylmethyl) adipate (epoxy equivalent: 180-200), 1,4-butanediol diglycidyl ether (epoxy equivalent: 125-200)
143) 20 parts, thermoplastic saturated polyester resin (manufactured by Toyobo Co., Ltd., trade name Vylon 300, molecular weight 20,000 ~
25000), 1 part of silicone surfactant, and 3 parts of photopolymerization initiator PP-33 (manufactured by Asahi Denka Kogyo Co., Ltd.) to a thickness of 120 μm.
soft vinyl chloride film (polyvinyl chloride 100
(Plasticizer content: 40 parts) was applied uniformly to the surface to a film thickness of 4 μm. Next, by irradiating ultraviolet rays with a high-pressure mercury lamp (output 80 W/cm, 4 KW) at a distance of 10 cm below the lamp at a speed of 20 m/min, a coated soft vinyl chloride film with excellent adhesion and flexibility of the cured film was obtained. Ta. This coated vinyl film showed no minute cracks or peeling phenomena in the cured film even after a 500-hour durability test using a Sunshine Super Long Run Weathermeter.

Furthermore, as a comparative test, a coated soft vinyl chloride film obtained using the energy ray curable resin composition containing no thermoplastic saturated polyester resin was found to have minute cracks in the cured film after 300 hours of weather testing. .

Example 3 60 parts of trimethylolpropane triglycidyl ether (epoxy equivalent: 135 to 165), 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexyl carboxylate (epoxy equivalent:
131-143) 30 parts, thermoplastic saturated polyester resin (manufactured by Gutdeyer, trade name Vitel PE-200, molecular weight 15,000-20,000) 10 parts, silicone surfactant 0.5 part, and photopolymerization initiator PP-33 (Asahi Denka) An energy beam curable resin composition consisting of 3 parts (manufactured by Kogyo Co., Ltd.) was applied to the surface of a 100μ polycarbonate film to a film thickness of 5μ, and placed under a high-pressure mercury lamp (output 80W/cm, 4KW) installed at a height of 10cm. ,
A cured film was obtained by UV irradiation by passing at a speed of 10 m/min. This coating showed excellent adhesion in a cross-cut peeling test using cellophane tape.

For comparison, when the curable resin composition containing no thermoplastic saturated polyester resin was used, peeling of the coating film was observed in a cross-cut peeling test using cellophane tape.

Example 4 20 parts of bisphenol A diglycidyl ether (epoxy equivalent 180-200), 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate (epoxy equivalent 131-143)
45 parts, 1,4-butanediol diglycidyl ether (epoxy equivalent: 125-143) 20 parts, thermoplastic saturated polyester resin (manufactured by Toyobo Co., Ltd., trade name: Vylon GK-130, molecular weight 5000-8000) 15 parts, silicone interface Activator 0.5 part and photoinitiator FC―
An energy beam curable resin composition consisting of 4 parts of 508 (manufactured by Minnesota Mining and Manufacturing Co.) was diluted with 25 parts of ethyl acetate solvent and applied to an aluminum sheet plate (0.2 m/m) in an amount of about 6 μm. The coating film was cured by irradiation for 2 seconds under a high-pressure mercury lamp (output 80 W/cm, 1 KW) installed at a height of 15 cm. The cured film applied to this aluminum plate showed excellent cellophane adhesiveness and bending workability.

Furthermore, in a comparative test, a coated aluminum sheet plate obtained using the curable resin composition containing no thermoplastic saturated polyester resin had insufficient adhesiveness with cellophane tape.

Example 5 3,4-epoxycyclohexylmethyl-3,
70 parts of 4-epoxycyclohexylmethylcarboxylate (epoxy equivalent: 131-143), bisphenol A diglycidyl ether (epoxy equivalent: 450
~500) 15 parts, thermoplastic saturated polyester resin (manufactured by Toyobo Co., Ltd., trade name: Vylon 200, molecular weight
15000-20000) 15 parts, blue pigment Heliogen Blue
(manufactured by BASF), 2 parts of a silica additive, and 4 parts of a photopolymerization initiator FC-508 (manufactured by Minnesota Mining and Manufacturing Company). It was printed on a white painted board and dried by irradiating it for 3 seconds under a high-pressure mercury lamp (output 80 W/cm, 1 KW) installed at a height of 15 cm. This cured ink showed good adhesion to the coated plate in the cross-cut cellotape test.

As a comparative test, the printed coated plate obtained using an energy ray-curable ink composition containing no thermoplastic saturated polyester resin did not exhibit good adhesion in the cellophane tape test.

Claims (1)

[Claims] 1. As essential components: (a) one or two epoxy resins that are liquid at room temperature and have at least one epoxy group in one molecule;
60 to 95 parts by weight (b) 5 to 40 parts by weight of a thermoplastic saturated polyester resin with an average molecular weight of 2,500 to 30,000 (c) A photopolymerization initiator that releases a substance that initiates cationic polymerization upon irradiation with energy rays, (a) , a liquid cationic polymerizable energy ray-curable resin composition containing 0.1 to 10 parts by weight per 100 parts by weight of the mixture (b). 2. Cationic polymerization energy beam curing according to claim 1, wherein the epoxy resin as component (a) contains 20 to 95% by weight of an alicyclic epoxy resin having an epoxy group on an alicyclic ring. resin composition. 3. Cationic polymerization-based energy beam curing according to claim 2, wherein the epoxy resin as component (a) contains 50 to 90% by weight of an alicyclic epoxy resin having an epoxy group on an alicyclic ring. resin composition. 4. The cationic polymerizable energy ray-curable resin composition according to any one of claims 1 to 3, wherein the thermoplastic saturated polyester resin as component (b) has an average molecular weight within the range of 5,000 to 25,000.