JPS6228972B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a curable resin composition that can be cured by irradiation with radioactive energy.

Epoxy resins have traditionally been widely used in the fields of paints, electrical and electronic components, adhesives, and civil engineering and construction, taking advantage of their excellent properties. Especially for paints, it has excellent chemical and water resistance, so it is used in overprint varnishes and circuit printing inks.

However, in order to cure epoxy resin,
There are disadvantages in that heating is required and curing at room temperature takes a long time, so photocuring methods are being considered from the viewpoint of improving workability and saving energy. Among these, epoxy resin compositions whose initiator is a compound that releases a Lewis acid upon irradiation with radioactive energy are approaching the level of practical use as coating resins.

The present inventors conducted various studies on such epoxy resin compositions, and found that they are composed of a conventionally known epoxy resin, a polycarboxylic acid anhydride, and a compound that releases a Lewis acid when irradiated with radioactive energy. A curable resin composition has been discovered that has a significantly faster curing speed than other curable resin compositions.

That is, the present invention provides (A) a compound that is an ester of an epoxy resin with an α,β-unsaturated carboxylic acid and has at least one epoxy group in the molecule; (B) an epoxy resin used as necessary; resin, (C) α, β of polycarboxylic acid or its acid anhydride
- A compound (D) which is an ester with a compound having an unsaturated group and a hydroxyl group and has at least one carboxyl group or acid anhydride group in the molecule, a polycarboxylic acid anhydride used as necessary, and (E ) Contains an initiator that generates a Lewis acid when irradiated with radioactive energy, and the (A) and (B) components are (B)/(A) from 0/10 to
9/1 (weight ratio), (C) component and (D) component are (D)/(C) 0/10 to 9/1 (weight ratio), epoxy group of (A) component and (B) component (C) component and
The total amount of carboxyl groups and acid anhydride groups of component (D) is 0.1 to 2 mol, and component (E) is (A) component, (B) component,
0.0001 to 0.2 relative to the total amount of component (C) and component (D)
% by weight.

The compound [(A) component] which is an ester of an epoxy resin with an α,β-unsaturated carboxylic acid and has at least one epoxy group in the molecule used in the present invention is the same as the following component (B). Epoxy resin and α,
It is a compound having at least one epoxy group in one molecule, which can be obtained by ester addition reaction of β-unsaturated carboxylic acid. In the above ester addition reaction, α,
Carboxyl group n-1/ of β-unsaturated carboxylic acid
n to 1/n equivalent (where n is the number of epoxy groups present in one molecule in the above epoxy resin)
It can be obtained by reacting at a ratio of

Here, the α,β-unsaturated carboxylic acid is
Examples include acrylic acid and methacrylic acid.

In the present invention, as component (A), a reaction product obtained by reacting an epoxy resin and an α,β-unsaturated carboxylic acid in a range other than the above ratio in the above ester addition reaction may be used as is. . For example, for 1 mole of the above epoxy resin,
Carboxyl group of the above α,β-unsaturated carboxylic acid
Obtained by reacting at a ratio of 0.1/1 or more and less than 1/n (however, n is the same as above) or more than n-1/n (however, n is the same as above) and 1.4/1 or less. It is something that Here, in the former case, unreacted epoxy resin is included, but this can be used as it is as component (B) below. In the latter case, the epoxy group of the epoxy resin may be completely esterified, but such a resin is not included in the curable resin composition of the present invention as a polyfunctional unsaturated compound. It's okay.

The epoxy resin [component (B)] used in the present invention is a compound having two or more epoxy groups in one molecule, (p-hydroxyphenyl)propane,
2,2'-bis(4-hydroxy-3,5-dibromphenyl)propane, 1,1,2,2-tetrakis(p-hydroxyphenyl)ethane, 4,4
-Glycidyl ethers of aromatic polyphenols such as dihydroxydiphenyl, resorcinol, catechol, and hydroquinone, phenol novolacs,
Novolak-type glycidyl ethers such as cresol novolak, alicyclics such as vinylcyclohexene diepoxide, limonene diepoxide, dicyclopentadiene diepoxide, (3',4'-epoxycyclohexylmethyl)-3,4-epoxycyclohexane carboxylate, etc. Epoxy resin,
Examples include heterocyclic epoxy resins such as triglycidyl isocyanurate and N,N'-diglycidyl derivatives of 5,5-dimethylhydantoin.

A compound that is an ester of a polycarboxylic acid or its acid anhydride used in the present invention with a compound having an α,β-unsaturated group and a hydroxyl group, and has at least one carboxyl group or acid anhydride group in the molecule [ Component (C)] is an esterification reaction of a polycarboxylic acid anhydride similar to component (D) below or a polycarboxylic acid ring-opened by the acid anhydride and a compound having an α,β-unsaturated group and a hydroxyl group. It is a compound having at least one carboxyl group or acid anhydride group in one molecule, and the hydroxyl group of the latter is m-
In the ratio of 1/m to 1/m equivalent (where m is the number of carboxyl groups present in one molecule in the above polycarboxylic acid, one acid anhydride group is considered as two carboxyl groups) It can be obtained by reaction.

Here, examples of compounds having α,β-unsaturated groups and hydroxyl groups include hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxybutyl acrylate, similar hydroxyalkyl methacrylates, diethylene glycol, dipropylene glycol, etc. Examples include monoacrylate or monomethacrylate of polyalkylene glycol, monoacrylate or diacrylate of polyhydric alcohol such as glycerin, trimethylolpropane, trishydroxyethyl isocyanurate, and pentaerythritol, and monomethacrylate or dimethacrylate similar to these.

Furthermore, as the component (C) of the present invention, it is possible to use a component reacted in a range other than the above-mentioned ratio in the above-mentioned esterification reaction. For example, with respect to 1 mole of the polycarboxylic anhydride, the hydroxyl group of the compound having an α,β-unsaturated group and a hydroxyl group in one molecule is 0.1/1 or more and less than 1/m (however, m
is the same as above) or beyond m-1/m
It was obtained by reacting at a ratio of 1.4/1 or less. Here, in the former case, unreacted polycarboxylic acid anhydride is included, but this can be used as it is as the component (D) below. In the latter case, the carboxyl group or acid anhydride group of polycarboxylic acid or its acid anhydride is completely esterified, and such compounds are included in the present invention as polyfunctional unsaturated compounds. It may be included in such a curable resin composition.

Polycarboxylic acid anhydride used in the present invention [(D)
Examples of ingredients include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, methylendomethylene phthalic anhydride, and succinic anhydride. Examples include dodecenylsuccinic anhydride, octenylsuccinic anhydride, trimellitic anhydride, pyromellitic anhydride, and these can be used alone or in combination of two or more.

The initiator [component (E)] that generates a Lewis acid upon irradiation with radioactive energy used in the present invention includes aromatic diazonium salts, iodonium salts,
Various onium salts such as sulfonium salts can be used. As onium salts other than diazonium salts, those represented by the following general formulas () and () can generally be used.

[(R ¹ ) _n (R ² ) _o X] ⁺ _a [MQb] ^-a () [(R ³ ) (R ⁴ ) (R ⁵ ) Y] ⁺ _a [MQb] ^-a () However, the general formula In (), R ¹ and R ² are monovalent aromatic groups or two together are divalent aromatic groups,
m and n are 0 or an integer whose sum is equal to 2 or the valence of X, and X is a halogen atom. In the general formula (), R ³ , R ⁴ and R ⁵ are a monovalent aromatic group, an alkyl group, a cycloalkyl group, or a divalent organic group constituting a heterocyclic or condensed ring structure, and R ³ , At least one of R ⁴ and R ⁵ is an aromatic group, and Y is a group a element such as sulfur, selenium, tellurium, etc. or N, P, As, Sb, etc.
It is a Va group element. R ¹ , R ² , R ³ , R ⁴ and R ⁵ may have a substituent. General formulas () and ()
Inside, M is Sb, Fe, Sn, Bi, Al, Ga, In, Ti,
Metals such as Zr, Sc, V, Cr, Mn, Cs, lanthanide rare earth elements (Ce, Pr, Nd, etc.), actinide rare earth elements (Th, Pa, U, Np, etc.) or B,
It is a metalloid such as P or As, Q is a halogen, b is an integer up to 8 that is larger than the valence of M, and a is the number obtained by subtracting the valence of M from b.
R ¹ , R ² , R ³ , R ⁴ and R ⁵ are typically phenyl groups or aryl groups such as substituted phenyl groups such as nitrophenyl groups, and the complex ion [MQb] ^-a is BF ₄ ^- , PF ₆ ^- , AsF ₆ ^- ,
SbF ₆ ^- , FeCl ₄ ^-- , SbCl ₆ ^- , SbCl ₆ ^- , BiCl ₅ ^-- ,
There are AlF ₆ ^--- , GaCl ₄ ^-- , InF ₄ ^-- , etc. Furthermore, aromatic diazonium salts include phenyl diazonium salts which may be substituted, and complex ions forming diazonium salts include the same ones as mentioned above.

Specific examples of component (E) include triphenylsulfonium hexafluoroantimonate, diphenyliodonium hexachloroantimonate, and triphenylsulfonium hexafluoroarsenate.

The above-described components (A), (B), (C), (D) and (E) are used in the following proportions.

The weight ratio of component (A) and component (B) is (B)/(A) from 0/10 to
It is in the range of 9/1, and particularly preferably 3/7 to 8/2. If the amount of component (B) used is too small, the effect of accelerating the curing speed will be reduced. In addition, in order to achieve a good balance between the heat resistance, chemical resistance, and curing speed of the epoxy resin, the weight ratio of (B)/(A) is 3/7.
A ratio of ~8/2 is particularly preferred.

The weight ratio of component (C) and component (D) is (D)/(C) from 0/10 to
It is in the range of 9/1, and particularly preferably 3/7 to 8/2. If the amount of component (D) is too small, the effect of accelerating the curing speed will be reduced. In addition, in order to achieve a good balance between the properties and curing speed of the cured product, (D)/
(C) is particularly preferably in a weight ratio of 3/7 to 8/2.

In addition, component (A), component (B), component (C), and component (D) are the combination of the epoxy groups of component (A) and component (B), and the amount of (C The total amount of acid anhydride groups and carboxyl groups in component ) and (D) is preferably 0.1 to 2 moles, preferably 0.3 to 2 moles.
It is particularly preferred that the amount is 1.5 mol. If the total amount of the acid anhydride group and carboxyl group is less than 0.1 equivalent per 1 equivalent of the epoxy group, curing tends to be insufficient, and if it exceeds 2 moles, the curing agent component becomes excessive, resulting in hardening Properties of objects tend to deteriorate.

Component (E) is used in an amount of 0.0001 to 0.2% by weight, particularly 0.001 to 0.1% by weight, based on the total amount of components (A), (B), (C) and (D). preferable. If the amount of component (E) is too small, curability tends to decrease, and if it is too large, the mechanical strength of the cured product tends to decrease. Component (E) not only serves as an initiator for the reaction between the epoxy groups in components (A) and (B) and the acid anhydride groups and carboxyl groups in components (C) and (D), but also It also serves as an initiator for the addition polymerization reaction of α,β-unsaturated bonds in components (A) and (B).

The curable resin composition of the present invention may further contain unsaturated monomers other than the components (A) and (B), a softening agent, a diluent, and the like.

Unsaturated monomers other than component (A) and (B) include ethyl acrylate, butyl acrylate, 2
- Alkyl acrylates such as ethylhexyl acrylate, methyl methacrylate, butyl methacrylate, alkyl acrylates such as 2-ethylhexyl acrylate, styrene or substituted styrenes such as α-methyl-styrene, chlorostyrene, vinyltoluene, ethylene glycol diacrylate, propylene glycol diacrylate ,
Diethylene glycol diacrylate, dipropylene glycol diacrylate, butanediol diacrylate, trimethylolpropane triacrylate, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, diethylene glycol dimethacrylate, dipropylene glycol dimethacrylate, butanediol dimethacrylate, trimethylolpropane triacrylate Examples include methacrylates, and complete esterification products of the above-mentioned epoxy resins and polycarboxylic acid anhydrides. If the amount of such unsaturated monomers is too large, the chemical resistance, heat resistance, etc. of the cured product will tend to decrease.
It is preferably used in an amount of 10% by weight or less, particularly 10% by weight or less.

The above-mentioned flexibility imparting agent includes saturated polyester dicarboxylic acid, and when using this,
It is used to replace 0 to 50 mol% of the polycarboxylic anhydride [component (C)].

Examples of the diluent include cresyl glycidyl ether, phenyl glycidyl ether, butyl glycidyl ether, styrene oxide, stearic acid glycidyl ester, etc.
It is used in an amount of 0 to 30% by weight based on the total amount of component (B).
If it exceeds 30% by weight, the mechanical strength of the cured product tends to decrease.

Other modifiers such as thixotropy-imparting agents may be appropriately added to the curable resin composition of the present invention. Further, the above-mentioned initiator [component (E)] is preferably used together with a compound capable of supplying protons, such as propylene carbonate and ethylene carbonate.

The curable resin composition according to the present invention is irradiated with radioactive energy and cured. As the radioactive energy, for example, ultraviolet rays having a wavelength of 1849 Å to 4000 Å and an intensity of 5000 to 80000 iCw/cm ² are used, and the equipment used therefor is a xenon lamp, a low-pressure, medium-pressure or high-pressure mercury lamp, or the like.

Next, examples and synthesis examples of the present invention will be shown.

Synthesis example 1 GY-250 (Ciba Geigy brand name, epoxy equivalent: 190, 2,2'-bis(p-hydroxyphenyl)propane diglycidyl ether) 95g
(0.25 mol) and 18 g (0.25 mol) of acrylic acid were reacted in a flask at 60°C for 5 hours to obtain a viscous liquid (epoxy acrylate). The acid value of the product is
The epoxy equivalent was 398 g/equivalent at 1.2 mg KOH/g. The resulting product is essentially an acrylic acid half ester of the epoxy resin described above.

Synthesis Example 2 168g (1 mol) of methylhexahydrophthalic anhydride and 116g (1 mol) of hydroxyethyl acrylate
mol) and 1.0 g of zinc oxide were reacted in a flask at 60°C for 8 hours to obtain a liquid product (polycarboxylic acid half ester). The acid value of the product is 206mgKOH/g
According to the infrared absorption spectrum, the absorption of the acid anhydride disappeared and the C=0 absorption of the ester appeared. The resulting product is essentially methylhexahydrophthalic acid monoacryloyloxyethyl ester.

Example 1 90 g of epoxy acrylate obtained in Synthesis Example 1, 57 g of methylhexahydrophthalic acid monoacryloyloxyethyl ester obtained in Synthesis Example 2, and 5 g of a 50% propylene carbonate solution of triphenylsulfonium hexafluoroantimonate were combined and treated. It was applied onto a steel plate and passed twice through a conveyor-type irradiator that irradiates ultraviolet rays with a 2KW high-pressure mercury lamp 10cm apart at a conveyor speed of 2m/min. The cured product had a smooth surface and was tack-free. The film thickness was 100μ, and the coating properties were as follows.

Pencil hardness: 3H Erichsen value: 65mm Solvent resistance (rubbing test with methyl ethyl ketone): No change Comparative example 1 GY-250 (epoxy resin) 95g and triphenylsulfonium hexafluoroantimonate
After mixing 5 g of a 50% propylene carbonate solution, an attempt was made to produce a cured coating film by irradiating the mixture with ultraviolet rays in the same manner as in Example 1, but the coating film was not cured.

The curable resin composition according to the present invention has excellent curability and also has good coating film properties.

Claims (1)

[Scope of Claims] 1 (A) An ester of an epoxy resin with an α,β-unsaturated carboxylic acid, which contains at least one carboxylic acid in the molecule.
(B) Epoxy resin used as necessary; (C) α, β of polycarboxylic acid or its acid anhydride;
- A compound (D) which is an ester with a compound having an unsaturated group and a hydroxyl group and has at least one carboxyl group or acid anhydride group in the molecule, a polycarboxylic acid anhydride used as necessary, and (E ) Contains an initiator that generates a Lewis acid when irradiated with radioactive energy, and the (A) and (B) components are (B)/(A) from 0/10 to
9/1 (weight ratio), (C) component and (D) component are (D)/(C) 0/10 to 9/1 (weight ratio), epoxy group of (A) component and (B) component (C) component and
The total amount of carboxyl groups and acid anhydride groups of component (D) is 0.1 to 2 mol, and component (E) is (A) component, (B) component,
0.0001 to 0.2 relative to the total amount of component (C) and component (D)
% by weight.