JPH05222112A - Curable composition containing pyridinium salt compound - Google Patents

Abstract

PURPOSE:To provide a curable composition containing a cationically polymerizable compound which cures at a low temp. within a short time upon light irradiation and/or heating. CONSTITUTION:The title composition comprises a cationically polymerizable compound, a pyridinium salt, and a compound (a) generating a free radical upon light irradiation and/or heating. This composition can be made to cure at a low temp. within a short time upon light irradiation and/or heating by suitably selecting the compound (a). It is suited for use as the material of a coating composition, adhesive, ink, etc., because it has excellent properties after curing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a curable composition, and more particularly to a cationically polymerizable composition which is cured by light irradiation and / or heat at a low temperature in a short time. A cured product of the composition has excellent physical properties and is therefore suitably used as a material for paints, adhesives, inks and the like.

[0002]

2. Description of the Related Art Examples of catalysts and compositions for curing cationically polymerizable compounds such as epoxy compounds by light irradiation are disclosed in JP-A-50-151997 and JP-A-50-158.
No. 680 and the like. A catalyst for curing a cationically polymerizable compound such as an epoxy compound by heating and a composition thereof are described in JP-A-56-1.
No. 52833, JP-A-58-37003, JP-A-63.
-222003, JP-A-2-178319, JP-A-3-17119 and the like are known. Further, a catalyst for curing a cationically polymerizable compound such as an epoxy compound by irradiation with light and heat and a composition thereof are disclosed in JP-A No. 2 (1994).
-196812 and the like.

[0003]

A compound obtained by cationically curing a cationically polymerizable compound such as an epoxy compound has a smaller curing shrinkage and a smaller curing shrinkage than a compound obtained by radically curing a radically polymerizable compound such as an acrylic compound. It has various characteristics such as not being affected by oxygen. A cationic polymerization catalyst is generally used for this cationic curing, and this includes a photocatalyst and a thermal catalyst. For example, as a catalyst for curing the cationically polymerizable compound by light irradiation, there are sulfonium salt-based catalysts, iron-arene complexes, and the like.
Although these catalysts show high photoactivity, it is impossible to cure the cationically polymerizable composition by heating in the temperature range that is usually used, so it is possible to cure a thick film even after heat treatment after photocuring. There is a problem that you can not do it. On the other hand, JP-A-58-37003 and JP-A-63-2
23002, JP-A-2-178319, JP-A-3-
Since the catalyst described in 17119 and the like is a thermal catalyst, the cationically polymerizable compound cannot be cured by irradiation with light, and in many cases, the temperature for initiating the polymerization is high, which is a problem in practical use. The catalyst described in JP-A-2-196812 is said to be capable of curing a cationically polymerizable compound by heating and light irradiation, but in the case of photocuring, its catalytic activity is remarkably high. Low.

Therefore, a catalyst showing high activity to both light and heat and a curable composition containing the same have not been known so far. Therefore, it goes without saying that if a composition exhibiting high curability against both light and heat is provided, it will be industrially useful in terms of its wide range of application. The present invention has been made in view of these circumstances, and provides a high-performance curable composition capable of curing a cationically polymerizable compound at low temperature and in a short time by light irradiation and / or heat. Has a purpose.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to achieve the above-mentioned object. In the case of photocuring, a pyridinium salt compound and a compound capable of generating an active radical upon irradiation with light are used in combination. It was found that a pyridinium salt compound can act as a photocationic polymerization catalyst, and a cationically polymerizable compound can be photocured. In the case of thermosetting, an active radical is generated by heating with a pyridinium salt compound. It was found that the decomposition temperature of the pyridinium salt compound occurs at a lower temperature by the combined use of the compound described above, and the curable composition for curing the cationically polymerizable compound of the present invention at low temperature and in a short time by light and / or heat. Got

The present invention is a curable composition containing component (A): a cationically polymerizable compound, component (B): a pyridinium salt compound, and component (C): a compound that generates an active radical.

The present invention will be described in detail below. Examples of the cationically polymerizable compound as the component (A) used in the present invention include the following compounds. (A) As a compound having an epoxy group, 1,1,3-
Tetradecadiene dioxide, limonene dioxide, 4-vinylcyclohexene dioxide, (3,4
-Epoxycyclohexyl) methyl-3,4-epoxycyclohexylcarboxylate, di (3,4-epoxycyclohexyl) adipate, phenylglycidyl ether, bisphenol A type epoxy resin, halogenated bisphenol A type epoxy resin, o-, m-, There are epoxy compounds such as p-cresol novolac type epoxy resin, phenol novolac type epoxy resin, and polyglycidyl ether of polyhydric alcohol.

(B) Styrene and α as vinyl compounds
-Styrenes such as methylstyrene and p-chloromethylstyrene; alkyl vinyl ethers such as n-butyl vinyl ether, isobutyl vinyl ether, cyclohexyl vinyl ether and hydroxybutyl vinyl ether;
Alkenyl vinyl ethers such as allyl vinyl ether and 1-octahydronaphthyl vinyl ether; alkynyl vinyl ethers such as ethynyl vinyl ether and 1-methyl-2-propenyl vinyl ether; aryl vinyl ethers such as phenyl vinyl ether and p-methoxyphenyl vinyl ether; butanediol divinyl ether , Alkyldivinyl ethers such as triethylene glycol vinyl ether and cyclohexanediol divinyl ether; aralkyl dialkyl ethers such as 1,4-benzenedimethanol divinyl ether, N-m-chlorophenyldiethanolamine divinyl ether and m-phenylene bis (ethylene glycol) divinyl ether. Vinyl ethers; hydroquinone divinyl ether, resorcinol divinyl ether Aryl divinyl ethers such as ether; N- vinylcarbazole, there is a cationic polymerizable nitrogen-containing compounds such as N- vinylpyrrolidone.

As the (C) bicycloorthoester compound, 1-phenyl-4-ethyl-2,6,7-trioxabicyclo [2,2,2] octane, 1-ethyl-4-
Hydroxymethyl-2,6,7-trioxabicyclo [2,2,2] octane etc. (d) As the spiro orthocarbonate compound, 1,
5,7,11-Tetraoxaspiro [5,5] undecane, 3,9-Dibenzyl-1,5,7,11-tetraoxaspiro [5,5] undecane and 1,4,6-trioxaspiro [4,4] nonane, 2-methyl-1,4
6-trioxaspiro [4,4] nonane, 1,4,6-
Examples thereof include spiro orthoester compounds such as trioxaspiro [4,5] decane. These may be used alone or in combination of two or more. Among (a) to (d), the compound having an epoxy group of (a) is preferably used.

The pyridinium salt compound of the component (B) used in the present invention is a compound represented by the following general formulas [1] and [2]. As a pyridinium salt compound [1],

[0011]

[Wherein R ₁ is a hydrogen atom, methyl, ethyl,
Represents an alkyl group such as propyl or butyl or a cyano group,
R ₂ represents an alkyl group such as methyl, ethyl, propyl or butyl or an optionally substituted phenyl group, R ₃
And R ₄ is a hydrogen atom, a halogen atom such as F, Cl, Br and I, an alkyl group such as methyl, ethyl, propyl and butyl, an alkoxy group such as methoxy and ethoxy, a nitro group, a cyano group, a vinyl group and carbamoyl. Represents a group or an alkanoyl group, and X is SbF ₆ , AsF ₆ , PF ₆ or B.
Representing F ₄ ] As a pyridinium salt compound [2],

[0012]

[Wherein R ₅ and R ₆ are hydrogen atoms, alkyl groups F, Cl, B such as methyl, ethyl, propyl and butyl.
represents a halogen atom such as r or I, or an alkoxy group such as methoxy or ethoxy, and R ₇ and R ₈ represent a hydrogen atom, F or C
1, halogen atom such as Br, I, alkyl group such as methyl, ethyl, propyl and butyl, alkoxy group such as methoxy and ethoxy, nitro group, cyano group, vinyl group, carbamoyl group or alkanoyl group, and X represents SbF. ₆ , A
represents sF ₆ , PF ₆ or BF ₄ ]

The pyridinium salt compound [1] used in the present invention can be obtained, for example, by the following method.
Cinnamyl bromide, crotyl bromide, 1-bromo-3-methyl-2-butene, etc. 3-substituted-1-halogeno-2-butene and pyridine or pyridine derivative are equimolar, and if necessary, an inert solvent such as methyl alcohol, acetone or acetonitrile. It can be obtained by reacting in the presence of room temperature to reflux temperature for several hours to 30 days, and then subjecting the obtained product to ion exchange. Examples of the salt used for ion exchange include Sb
Examples thereof include alkali metal or alkaline earth metal salts of F ₆ , AsF ₆ , PF _{6 and} BF ₄ .

The pyridinium salt compound [2] used in the present invention can be obtained, for example, by the following method.
Room temperature in the presence of an inert solvent such as methyl alcohol, acetone or acetonitrile, if necessary, in equimolar amounts of halogenated methylnaphthalene derivative such as α-bromomethylnaphthalene or β-bromomethylnaphthalene and pyridine or pyridine derivative. From several hours to 30 at reflux temperature
It can be obtained by reacting for a day and then subjecting the resulting product to ion exchange. Examples of the salt used for ion exchange include SbF ₆ , AsF ₆ , PF _{6 and} BF _4.
The alkali metal or alkaline earth metal salts of

The compound which generates an active radical as the component (C) of the present invention is a compound which generates an active radical by heating or light irradiation, and examples thereof include the following.

(A) Compound that generates active radicals by light irradiation As a compound that generates active radicals by light irradiation,
A generally known photo-radical initiator can be applied, and examples thereof include benzyl type, benzoin ether type, benzyl ketal type, benzophenone type and thioxanthone type. In addition, azo compounds such as azoisobutyronitrile, azide compounds, disulfide compounds, and peroxide compounds are applicable. Particularly, a ketone-based photo radical initiator is preferably applied. For example, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-benzoyl-4′-methyldiphenyl sulfide, 3,3′-dimethyl-4-methoxybenzophenone, tetra (t-butylperoxycarbonyl) benzophenone, 2-chloro. Thioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, anthraquinone, 2-ethylanthraquinone, 1,8-dichloroanthraquinone, 1,2-benzanthraquinone, 9-fluorenone. , Benzanthuron, 9,10-phenanthrenequinone xanthone and the like are used.

(B) Compound which generates active radical by heating As a compound which generates active radical by heating, generally known azo compounds such as azoisobutyronitrile, azide compounds, disulfide compounds and peroxides. A compound or the like is applied. In particular, peroxide compounds are preferably applied, and the following compounds are used, for example. Ketone peroxides such as methyl ethyl ketone peroxide, cyclohexanone peroxide, acetylacetone peroxide; 1,1-bis (t-butylperoxy) cyclohexanone, 2,2-
Peroxyketals such as bis (t-butylperoxy) butane; Hydroperoxides such as t-butyl hydroperoxide and cumene hydroperoxide; Dialkyls such as dicumylperoxide and di-t-butylperoxide Peroxide; Diacyl peroxide such as isobutyl peroxide, acetyl peroxide and benzoylperoxide; Peroxycarbonate such as diisopropylperoxycarbonate; Peroxy such as t-butylperoxyacetate and cumylperoxyneodecanate Esters; acetylcyclohexyl sulfonyl peroxide, tetra (t-butylperoxycarbonyl) benzophenone and the like can be applied. In particular, aromatic diacyl peroxide and peroxy ester are preferably used.

The mixing ratio of the cationically polymerizable compound as the component (A) and the pyridinium salt compound as the component (B) is 0.01 to 20 parts by weight, preferably 100 parts by weight of the cationically polymerizable compound. It is mixed in a proportion of 0.1 to 10 parts by weight. If the amount of this pyridinium salt compound is less than 0.01 parts by weight, the curability of the cationically polymerizable compound will be reduced, and if it exceeds 20 parts by weight, the properties of the cured product will be reduced.

On the other hand, the compounding ratio of the component (A) cationically polymerizable compound and the component (C) active radical-generating compound is from 0.01 to 100 parts of the cationically polymerizable compound to the compound capable of generating activity. 20 parts by weight, preferably 0.
It is mixed in a ratio of 1 to 10 parts by weight. If the amount of the active radical generator is less than 0.01, the photocurability of the cationically polymerizable compound and the curing temperature cannot be reduced, and
If it exceeds the amount by weight and becomes excessive, the properties of the cured product deteriorate.

The curable composition of the present invention can be easily cured by light and / or heat. When the curable composition of the present invention is photocured, light having a wavelength of 500 nm or less, particularly ultraviolet rays, is preferably used, and therefore, as a light source, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a metal halide lamp, xenon is used. Lamps, carbon arc lamps, etc. are used. When thermosetting, it is used in the range of 30 to 200 ° C, preferably 60 to 180 ° C.

The curable composition of the present invention also contains α rays and β rays.
It can also be easily cured in a short time by ionizing radiation such as rays, γ rays, neutron rays and accelerated electron rays. Usually 0.5-60 Mrad for curing by ionizing radiation
A dose range of 1 to 50 Mrad can be used, with a range of 1 to 50 Mrad being preferred. It is also possible to cure by using light, ionizing radiation and heat in combination.

In the curable composition of the present invention, since the component (B) of the pyridinium salt compound is a latent thermal cationic polymerizable initiator, the cationic polymerizable compound component (A) can be cured by heat, resulting in thick film curing. Is possible. On the other hand, by using a pyridinium salt compound and a compound that generates an active radical upon irradiation with light, the pyridinium salt compound can function as a photocatalyst, and thus the cationically polymerizable compound can be photocured. In addition, by using a pyridinium salt compound and a compound that generates an active radical by heating, the decomposition temperature of the pyridinium salt compound can occur at a low temperature, and the cationically polymerizable compound can be thermoset at a lower temperature.

In addition to the components used in the present invention, for example, when the compound (a) having an epoxy group is used as the cationically polymerizable compound (A), it is usually used as a curing agent for epoxy resins. Hardeners such as phenolic hardeners and acid anhydride hardeners are used. Also,
If necessary, a reactive diluent, a curing accelerator, a solvent, a pigment, a dye, a coupling agent, an inorganic filler, carbon fibers, glass fibers, a surfactant, etc. may be added to the curable composition of the present invention. It is also possible to do so.

[0024]

EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples. However, the present invention is not limited to these examples. Examples 1 to 50 Various pyridinium salt compounds are dissolved in propylene carbonate, and ERL-4221 (UCC alicyclic epoxy) or UVR-6410 (UCC glycidyl epoxy) becomes 2.5 parts by weight as a pure component. As described above, 2.5 parts by weight of a compound that generates various active radicals was added to each epoxy to prepare a curable composition.
(Details of composition at the time of preparation are summarized in Tables 1 to 5)

Comparative Examples 1 to 50 A curable composition corresponding to each Example was prepared in the same manner with a compounding composition excluding compounds that generate active radicals. (Details of composition contents at the time of preparation are summarized in Tables 2 to 5)

<Preparation of Test Piece for Test> The test pieces used in Tests I and II of Examples and Comparative Examples were prepared by using the above-mentioned curable composition so that the thickness of the tin plate was 10 μm with a doctor blade. It was prepared by coating.

<Test Method> (i) Photocurability Test I The test piece was irradiated with an ultrahigh pressure mercury lamp at 5 J / cm ² . At this time, those in which the coating film is cured are indicated by ◯, and those which are not cured are indicated by X in Table 1 (101 to 104) and Table 2.

[0028]

[Table 101]

[0029]

[Table 102]

[0030]

[Table 103]

[0031]

[Table 104]

[0032]

[Table 2]

(Ii) Photocurability Test II The curable composition was subjected to UV-DSC measurement, and the time from UV irradiation to the top of the exothermic peak was determined and summarized in Table 3. The measurement conditions of UV-DSC are as follows. Measuring equipment of DSC: DSC220C (manufactured by Seiko Denshi Kogyo Co., Ltd.) UV irradiator: Ultra-high pressure mercury lamp atmosphere: Nitrogen gas stream 30 ml / min Measurement temperature: 50 ° C Sample amount: 0.1-0.3 mg Membrane thickness: 2- 10 μm Illumination time: 15 minutes Illumination: 10 mW / cm ² (365 nm)

[0034]

[Table 3]

(Iii) Electron beam curability test A test piece was irradiated with a 20 Mrad electron beam at an accelerating voltage of 175 KV. At this time, those in which the coating film is cured are indicated by ◯, and those in which the composition is thickened are indicated by Δ, in Table 4.

[0036]

[Table 4]

(Iv) Thermosetting test The compound was subjected to DSC measurement, and the exothermic onset temperature and D
The top peak temperature of the SC curve was determined and summarized in Table 5. The measurement conditions of DSC are as follows. Measuring equipment of DSC: DSC220C (Seiko Denshi Kogyo Co., Ltd.) Atmosphere: Nitrogen gas stream 30 ml / min Temperature rising speed: 10 ° C / min Sample amount: 0.3-0.8 mg

[0038]

[Table 5]

[0039]

As described above, the curable composition of the present invention can be cured at low temperature and in a short time by irradiation with light and / or heat. That is, the present invention has the following effects. (1) At the time of curing, in addition to the cationically polymerizable compound (A) and the pyridinium salt compound (B), as the component (C), a compound that generates an active radical by light or a compound that generates an active radical by heat is appropriately used. By selecting and adding,
The curing conditions can be freely selected. (2) In the case of effecting with light, high photocurability is exhibited as compared with the case where photocuring does not proceed at all without adding a compound that generates an active radical by light. (3) In the case of curing with heat, it is possible to cure at a much lower temperature than in the case of not adding a compound that generates active radicals with heat. Further, the thermosetting temperature can be controlled by appropriately selecting a compound that generates an active radical by heat. (4) Furthermore, it is also possible to coexist a compound that generates an active radical by light and a compound that generates an active radical by heat in the reaction system to perform photocuring, and then perform heat curing at low temperature as after cure. .. (5) Since the cured product of the curable composition has excellent physical properties, it is suitably used as a material for paints, adhesives, inks and the like. (Hereafter, margin)

[Chemical 1]

[Chemical 1]

Claims (2)

[Claims] 1. A curable composition comprising component (A): a cationically polymerizable compound, component (B): a pyridinium salt compound, and component (C): a compound that generates an active radical. 2. The curable composition according to claim 1, wherein the compound (C) which generates an active radical is a compound which generates an active radical upon irradiation with light and / or heat.