JP2001064324A - Polymer composition and ink varnish - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polymer compsn. excellent in both surface curing and interior curing, and an ink varnish contg. this compsn. SOLUTION: This polymer compsn. comprises a reaction product (a) of a dicarboxylic acid anhydride of a cyclic alkane having an alkyl group and a (meth)acrylic ester (b) having a hydroxyl group. It is pref. that (a) is an alkylhexahydrophthalic anhydride such as a methylhexahydrophthalic anhydride or the like and (b) is a (meth)acrylic ester having at least two (meth)acroyloxy groups in the molecule such as pentaerythritol triacrylate, or the like. The ink varnish comprises the polymer compsn.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymerizable composition comprising a specific (meth) acrylate and an ink varnish using the composition. The composition of the present invention comprises:
It can be used for applications such as inks, coatings, resists and adhesives, and can be particularly suitably used as an ink, and is awarded in these technical fields.

[0002]

2. Description of the Related Art Photopolymerizable or photocurable compositions which initiate radical polymerization by active energy rays such as ultraviolet rays and electron beams are used in the fields of inks, coating agents, resists and adhesives. . Since this radical polymerization is inhibited by oxygen in the atmosphere, it is preferable to irradiate with an active energy ray under a nitrogen atmosphere containing no oxygen or a low oxygen partial pressure. However, when the thin film is cured, for example, in an ink composition used for a printing method having a small film thickness such as lithographic printing, even if a means for removing oxygen in an irradiation atmosphere is provided, the ink is mixed or left. A small amount of oxygen tends to cause surface curing failure.

On the other hand, when a thick film is cured, poor curing inside the film may be a problem in addition to poor surface curing due to oxygen in the atmosphere. In particular, in an ink composition containing a colorant, a pigment, and the like and used in a printing method having a large film thickness such as intaglio printing or stencil printing, the internal curability (thick film curability) tends to be insufficient. In order to improve the internal curability, a so-called sensitizer or the like may be added to the photocurable composition. However, the use of a conventional general sensitizer not only increases the cost of raw materials, but also tends to induce new problems such as discoloration of the cured product and generation of odor.

[0004]

An object of the present invention is to provide a composition having radical polymerizability, which is excellent in both surface curability and internal curability, and containing this composition. It is to provide an ink varnish that does.

[0005]

Means for Solving the Problems The present inventors have found that a polymerizable composition containing a reaction product of a compound having a specific structure and a compound having a polymerizable functional group can solve the above problems. Thus, the present invention has been completed.

That is, the polymerizable composition of the present invention comprises:
It is characterized by containing a reaction product of (a) a dicarboxylic anhydride of a cyclic alkane having an alkyl group and (b) a (meth) acrylate ester having a hydroxyl group. The above (a) is preferably an alkyl hexahydrophthalic anhydride, and the above (b) is preferably a (meth) acrylic acid ester having two or more (meth) acryloyloxy groups in one molecule. preferable. The reactant is preferably obtained by reacting (a) at a ratio of 0.2 to 1.0 mol with respect to 1.0 mol of the hydroxyl group in (b).

[0007] The ink varnish of the present invention is characterized by containing the polymerizable composition of the present invention.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
In the present specification, an acrylate and / or a methacrylate is referred to as a (meth) acrylate, and an acryloyloxy group and / or a methacryloyloxy group is referred to as a (meth) acryloyloxy group.

The polymerizable composition of the present invention comprises (a) a dicarboxylic acid anhydride of a cyclic alkane having an alkyl group (hereinafter, referred to as a dicarboxylic acid anhydride).
Also referred to as "component (a)." ) And (b) a (meth) acrylic acid ester having a hydroxyl group (hereinafter also referred to as “component (b)”). The composition of the present invention comprises:
Two or more of the reactants may be contained.

Although the structure of the cyclic alkane moiety in the component (a) of the present invention is not particularly limited, the cyclic alkane is preferably 4 to 8 in view of the stability, price and availability of the compound.
Those having a membered ring are preferred, those having a 5- to 7-membered ring are more preferred, and those having a 6-membered ring are most preferred. When a compound in which this portion is not a cyclic alkane but a ring having an unsaturated bond (eg, a cyclic alkene, an aromatic ring, or the like) is used, the effects of the present invention, that is, the effects of improving surface curability and internal curability Cannot be fully demonstrated.

A dicarboxylic anhydride group is bonded to the cyclic alkane. Further, at least one linear or branched alkyl group is bonded to this cyclic alkane. A preferred range of the number of carbon atoms constituting the alkyl group is 1 to 10, a more preferred range is 1 to 6, and a still more preferred range is 1 to 4. Further, a plurality of alkyl groups may be bonded to the cyclic alkane, and in that case, the types of the alkyl groups may be the same or different. One or more substituents other than an alkyl group may be bonded to the cyclic alkane by one or more, as long as the effects of the present invention are not impaired. Examples of the substituent other than the alkyl group include a halogen atom and an amino group.

(A) preferably used in the present invention
The components include 3-methylhexahydrophthalic acid,
Examples include alkyl hexahydrophthalic acids such as methyl hexahydrophthalic acid.

As the component (b) of the present invention, a hydroxyl group is represented by n
(N; an integer of 2 or more) or more and 1 to
Examples thereof include an esterification reaction product with (n-1) pieces of (meth) acrylic acid and an alkylene oxide adduct thereof.
As the alkylene oxide, ethylene oxide (E
O) or propylene oxide (PO) is preferred,
The preferred number of added moles is 1 to 10 moles, more preferably 1 to 5 moles.

The above polyol is preferably one having three or more hydroxyl groups in one molecule. Specific examples of such a polyol include trimethylolpropane, trimethylolethane, glycerin, trihydroxyethyl isocyanurate, pentaerythritol, ditrimethylolpropane, dipentaerythritol, diglycerin, and alkyl group-substituted products thereof. . Further, a polyol obtained by adding an alkylene oxide to the above polyol may be used. As this alkylene oxide, EO or PO is preferable, and the preferred number of moles of addition is 1 to 10 mol, more preferably 1 to 5 mol.

As the component (b) of the present invention, (meth) acrylic acid esters having two or more (meth) acryloyloxy groups in one molecule are preferable because of excellent curability and hardness of the cured product. used. Specific examples of the (meth) acrylate having a hydroxyl group and having two or more (meth) acryloyloxy groups include pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, and dipentaerythritol Tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, trimethylolpropane di (meth) acrylate, ditrimethylolpropane di (meth) acrylate, ditrimethylolpropane tri (meth) acrylate, tris-2-hydroxyethyl isocyanurate Di (meth) acrylate, glycerin di (meth) acrylate, diglycerin di (meth) acrylate, diglycerin tri (meth) acrylate,
And their alkylene oxides (EO, PO, etc.)
Denatured products. Among them, pentaerythritol tri (meth) acrylate and dipentaerythritol penta (meth) acrylate are particularly suitable as the component (b) because the curability of the composition and the hardness of the cured product are high.

The addition reaction product of the above polyol and (meth) acrylic acid is generally a mixture of compounds having different numbers of (meth) acryloyloxy groups or hydroxyl groups, and the number of hydroxyl groups is determined by titration or the like. It is required. When a mixture of a plurality of compounds is used as the component (b), the number of the functional groups A in the component (b) is “two or more in one molecule”. It means that the average number of functional groups A per molecule is 2 or more, calculated from the number of A and the molar ratio of the compound to the whole component (b). This component (b) may have a functional group other than a hydroxyl group and a (meth) acryloyloxy group as long as the effects of the present invention are not impaired.

The polymerizable composition of the present invention contains a reaction product of the component (a) and the component (b). This addition reaction may be performed by a conventionally known method or the like. As a catalyst for the addition reaction, a basic catalyst such as pyridine and triethylamine can be used. The preferred amount of catalyst is
It is 0.1 to 5% by weight based on the reaction solution. The reaction temperature is
The temperature may be appropriately determined depending on the compound to be used and the like, but is generally preferably 60 to 140 ° C. In this reaction, in order to stably perform the reaction, hydroquinone, hydroquinone monomethyl ether, catechol,
It is preferable to add a polymerization inhibitor such as pyrogallol, phenothiazine, or N-nitrosophenol hydroxylamine aluminum salt, or to blow in molecular oxygen. When a polymerization inhibitor is used, 10
It is preferable to use it in the range of wtppm to 2 wt%.

In the present invention, it is preferable that this addition reaction is carried out substantially without a solvent. In this case, there is an advantage that a solvent-free polymerizable composition can be obtained without performing a step of distilling a reaction solvent from a reaction solution. Further, this reaction may be performed in an organic solvent, in which case, a solvent consisting of one or more selected from benzene, toluene, xylene, ethyl acetate, butyl acetate, methyl isobutyl ketone, etc. is obtained. The concentration of the reactants to be obtained is 20-8
It is preferably used in an amount of 0% by weight.

The reaction product obtained by this addition reaction is
Component (a) is added in an amount of 0.2 to 1.0 mol (more preferably 0.4 to 1.0 mol, and still more preferably 0.6 to 1.0 mol) with respect to 1.0 mol of the hydroxyl group in the component (b). (Mol) is preferable. If the number of moles of the component (a) is less than 0.2 mole, the effect of improving curability may not be sufficiently exhibited. On the other hand, if the number of moles of the component (a) exceeds 1.0 mole, the system tends to gel during the addition reaction. The reaction ratio can be adjusted by adjusting the charging ratio of the component (a) and the component (b), the conditions of the addition reaction, and the like.

The polymerizable composition of the present invention may contain, in addition to a reaction product of the component (a) and the component (b), one or more other compounds having a radical polymerizable functional group. Examples of the “other compound” include polyfunctional (meth) acrylates having no hydroxyl group such as pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and trimethylolpropane triacrylate. No. Among these other compounds, those having low viscosity can also be used as a reactive diluent for adjusting the viscosity of the composition. From the viewpoint of curability and hardness of a cured product, the other compound is preferably a compound having two or more polymerizable functional groups in one molecule. The ratio of the reaction product of the component (a) and the component (b) to the total amount of the reaction product of the component (a) and the component (b) and the other compound is as follows:
It is preferably at least 30% by weight, more preferably at least 50% by weight. If the proportion is less than 30% by weight, the effect of improving the surface curability and the internal curability may not be sufficiently obtained.

In addition, the polymerizable composition of the present invention contains general additives such as a viscosity modifier, a filler, a coloring pigment, an adhesion-imparting agent, a leveling agent, a stabilizer, a crosslinking agent, and a polymerization inhibitor. Can be included. The composition may contain an organic solvent, but the content is preferably 20% by weight or less, more preferably 10% by weight or less based on the whole composition.

The effect of the polymerizable composition of the present invention is most remarkably exhibited when it is cured by light such as ultraviolet rays. However, the composition can be cured by heat, an electron beam or the like. As a specific method therefor, these usual curing means can be directly applied.

When curing with light such as ultraviolet light,
Usually, a photopolymerization initiator is contained in the polymerizable composition.
As the photopolymerization initiator, a conventionally known photopolymerization initiator such as benzophenone, benzoin, benzoin alkyl ether, acetophenone-based, and acylphosphine oxide-based is usually used. (Preferably 1 to 10% by weight). In addition, when the composition is photocured, the polymerizable composition of the present invention exhibits sufficient surface curability and internal curability without adding a photosensitizer. However,
A small amount of a photosensitizer such as triethanolamine or methyldiethanolamine may be used to obtain higher photocurability.

The polymerizable composition of the present invention is excellent in surface curability and internal curability, and thus is suitable as a coating agent for ink varnishes and paints, a resist, an adhesive and the like. Since the reaction product with the component (a) and the component (b) has a large amount of carboxyl groups, the composition of the present invention can be used as an alkali-developing resist or the like.

The ink varnish of the present invention contains the polymerizable composition of the present invention as an essential component, and may contain an acrylic acid-modified epoxy resin, a reactive diluent, diallyl phthalate, and the like, if necessary. When this ink varnish is used as a photocurable ink, it usually contains a photopolymerization initiator as described above. The acrylic acid-modified epoxy resin is added for the purpose of increasing the hardness of the cured product, and is usually 5 to 60% by weight (preferably 20 to 20% by weight).
About 50% by weight). Preferred specific examples include bisphenol A type epoxy (meth) acrylate and novolak type epoxy (meth) acrylate. The reactive diluent is added for the purpose of adjusting the viscosity of the ink varnish and the like, and is usually used in an amount of about 5 to 60% by weight (preferably 10 to 50% by weight). Preferred specific examples include polyethylene glycol di (meth) acrylate and hexanediol di (meth) acrylate.

An ink composition is prepared by adding a coloring pigment, a polymerization inhibitor, a leveling agent and the like to the ink varnish. The ink varnish of the present invention is suitable for an ink composition used in any printing method such as lithographic printing, intaglio printing, and stencil printing. In particular, even in intaglio printing and stencil printing, which have been conventionally difficult to apply because the ink is a thick film, a sufficient internal curability can be obtained by the ink composition using the ink varnish of the present application.

[0027]

The details of the reason why the polymerizable composition of the present invention is excellent in both surface curability and internal curability are unknown, but are presumed as follows. The reaction product of the component (a) and the component (b) has an alkyl group bonded to a cyclic alkane due to the structure of the component (a). Hydrogen atoms in this alkyl group are easily extracted by radicals generated in the composition during light irradiation. Radicals generated by this hydrogen abstraction are exchanged between molecules, which increases the amount of radicals generated in the composition, and it is considered that polymerization inhibition by oxygen is reduced. Further, as described above, when a compound in which the cyclic alkane moiety is replaced with an aromatic ring or a ring having an unsaturated bond is used, the effect of improving the surface curability and the internal curability cannot be sufficiently obtained. This is presumed to be because radicals generated by hydrogen abstraction are stabilized in the molecule when having such a structure, and the exchange of radicals between molecules is smaller than in the case of cyclic alkanes. You.

[0028]

The present invention will be described more specifically with reference to the following examples. In the following description, “parts” means parts by weight,
"%" Means% by weight. For example, a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate in a molar ratio of 70:30 is referred to as “pentaerythritol tri / tetraacrylate (70 /
30) ".

Example 1 A hydroxyl value of 160 mg KOH /
g of pentaerythritol tri / tetraacrylate (70/30) and 95 g of 4-methylhexahydrophthalic anhydride (1.0 mol per 1.0 mol of pentaerythritol triacrylate) were added to 1.5 g of triethylamine. Was reacted at 80 ° C. for 4 hours. At this time, the addition reaction rate of 4-methylhexahydrophthalic anhydride was 100%. That is, a reaction solution containing a reaction product obtained by reacting 1.0 mol of pentaerythritol triacrylate with 1.0 mol of 4-methylhexahydrophthalic anhydride was obtained. This reaction solution also contains pentaerythritol tetraacrylate.

To 100 parts of the obtained reaction solution, 2 parts of benzoin ethyl ether as a photopolymerization initiator was blended, and the composition was formed into a film under the following conditions to form an uncured coating film for evaluating curability. Created. [Film formation conditions] Coating method: Bar coater No. Use 20 Coating thickness: 10-20 μm

The uncured coating film was irradiated with ultraviolet rays by the following method, and its surface curability and internal curability were evaluated by the following methods. Table 1 shows the results. [Ultraviolet irradiation conditions] Lamp: 80 W / cm condensing high-pressure mercury lamp Lamp height: 10 cm Conveyor speed: 10 m / min

[Evaluation of Curability] Surface curability: After repeatedly passing under an ultraviolet lamp four times under the above irradiation conditions in an air atmosphere, the cured state of the coating film surface was evaluated by touching with a finger. The evaluation results are shown in the following four stages. ◎: Good (no surface tack) ○: Almost good (slight surface tack) △: Slightly poor (surface tack) ×: Not cured Internal curing: Under an air atmosphere, under an ultraviolet lamp under the above irradiation conditions After passing through a predetermined number of times, the coating film surface was rubbed with a finger so that the surface and the uncured portion were turned up and evaluated by the number of passes until the whitening was stopped.

Example 2 Hydroxyl value 115 mg KOH /
g of pentaerythritol tri / tetraacrylate (60/40) and 65 g of 4-methylhexahydrophthalic anhydride (0.95 mol per 1.0 mol of pentaerythritol triacrylate) were added to 1.3 g of triethylamine. Was reacted at 80 ° C. for 4 hours. The addition reaction rate of 4-methylhexahydrophthalic anhydride was 100%. The resulting reaction solution contains a reaction product of pentaerythritol triacrylate and 4-methylhexahydrophthalic anhydride and pentaerythritol tetraacrylate. Using this reaction solution,
In the same manner as in Example 1, the photopolymerization initiator was blended, applied, and evaluated for curability. Table 1 shows the results.

Example 3 Hydroxyl value 90 mg KOH / g
Of 200 g of dipentaerythritol penta / hexaacrylate (60/40) and 50 g of 4-methylhexahydrophthalic anhydride (0.92 mol per 1.0 mol of dipentaerythritol pentaacrylate) were added to 1.ethyl triethylamine. The reaction was carried out at 80 ° C. for 4 hours using 2 g as a catalyst. The addition reaction rate of 4-methylhexahydrophthalic anhydride was 100%. The resulting reaction solution contains the reactants and dipentaerythritol hexaacrylate. Using this reaction solution, the compounding, application, and curability evaluation of the photopolymerization initiator were performed in the same manner as in Example 1. Table 1 shows the results.

Example 4 Hydroxyl value 30 mg KOH / g
200 g of dipentaerythritol penta / hexaacrylate (20/80) and 17 g of 4-methylhexahydrophthalic anhydride (equimolar to dipentaerythritol pentaacrylate) were mixed with 1.0 g of triethylamine as a catalyst. The reaction was carried out at 80 ° C. for 4 hours while removing water from the mixture. The addition reaction rate of 4-methylhexahydrophthalic anhydride was 100%. The resulting reaction solution contains the reactants and dipentaerythritol hexaacrylate. Using this reaction solution, the compounding, application, and curability evaluation of the photopolymerization initiator were performed in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 1 Comparative Example 1 is a cyclic alkane dicarboxylic anhydride having an alkyl group.
In this example, phthalic anhydride, which is an aromatic dicarboxylic acid having no alkyl group, is used in place of methylhexahydrophthalic anhydride. The hydroxyl value used in Example 1 was 160
200 g of pentaerythritol tri / tetraacrylate (70/30) of mgKOH / g and phthalic anhydride 4
8 g (1.0 mol per 1.0 mol of pentaerythritol triacrylate) and triethylamine 1.4
The reaction was carried out at 80 ° C. for 4 hours using g as a catalyst. The addition reaction rate of phthalic anhydride was 100%. Using this reaction solution, the compounding, application, and curability evaluation of the photopolymerization initiator were performed in the same manner as in Example 1. Table 1 shows the results.

(Comparative Example 2) This Comparative Example 2 is a dicarboxylic acid anhydride of a cyclic alkane having an alkyl group.
In this example, tetrahydrophthalic anhydride, which is a dicarboxylic acid of a cyclic alkene having no alkyl group, is used in place of methylhexahydrophthalic anhydride. Dipentaerythritol penta / hexaacrylate (60/40) 20 having a hydroxyl value of 90 mg KOH / g used in Example 3
0 g and 48 g of tetrahydrophthalic anhydride (0.92 mol per 1.0 mol of dipentaerythritol pentaacrylate) were reacted at 80 ° C. for 4 hours using 1.2 g of triethylamine as a catalyst. The addition reaction rate of tetrahydrophthalic anhydride was 100%. Using this reaction solution, the compounding, application, and curability evaluation of the photopolymerization initiator were performed in the same manner as in Example 1. Table 1 shows the results.

Table 1 shows the properties of the reaction liquids obtained in Examples and Comparative Examples, and the results of evaluation of the curability. here,
The color tone of the reaction solution was evaluated in comparison with an APHA standard solution, and the viscosity was measured with a B-type viscometer at 25 ° C. and 12 rpm.

[0039]

[Table 1]

As can be seen from Table 1, the compositions of Examples 1 to 4 containing the reaction product of 4-methylhexahydrophthalic anhydride and a (meth) acrylic acid ester having a hydroxyl group were surface-hardened. Both properties and internal curability were good. An ink varnish was prepared by mixing 35 parts of the reaction solution obtained in Example 1, 50 parts of phenol novolak type epoxy acrylate, 35 parts of polyethylene glycol diacrylate and 5 parts of benzoin ethyl ether. In addition, ink varnishes were similarly produced using the reaction liquids obtained in Examples 2 to 4. When the surface curability and internal curability of these varnishes were evaluated in the same manner as above,
As in the above, it was excellent in surface curability and internal curability, and also had performance that did not cause any problem as an ink varnish.

On the other hand, in Comparative Example 1 in which phthalic anhydride was used instead of 4-methylhexahydrophthalic anhydride, both the surface curability and the internal curability were low. Also, 4
Comparative Example 2 using tetrahydrophthalic anhydride instead of methylhexahydrophthalic anhydride is a compound having a larger number of acryloyloxy groups per molecule than Comparative Example 1 as a (meth) acrylic acid ester having a hydroxyl group. Although the curability was slightly improved due to the use of
The curability was clearly lower than that of. In Table 1, the curability is a result of irradiation with ultraviolet rays in an air atmosphere, and a result of evaluation in the same oxygen concentration atmosphere.

In the present invention, various conditions can be changed within the scope of the present invention according to the purpose and application without being limited to those shown in the above specific examples.

[0043]

The polymerizable composition of the present invention is suitable as an ink varnish, a coating agent, an adhesive, etc. because of its excellent surface curability and internal curability. Also,
Since it contains a reactant having a large number of carboxyl groups, it can be used as an alkali-developable resist. The ink varnish of the present invention comprising this polymerizable composition is useful as a material for a printing ink composition because of its excellent surface curability and internal curability, and in particular, an intaglio that has been conventionally difficult to apply. It can be suitably used for printing and stencil printing.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J039 AD21 BE27 CA04 EA03 EA06 EA08 4J100 AL66P AL67P BA03P BA15H BC04H BC75P CA01 CA04 CA31 HA11 HC28 JA07

Claims (5)

[Claims] 1. A polymerizable composition comprising a reaction product of (a) a dicarboxylic anhydride of a cyclic alkane having an alkyl group and (b) a (meth) acrylate ester having a hydroxyl group. 2. The polymerizable composition according to claim 1, wherein (a) is an alkyl hexahydrophthalic anhydride. 3. The polymerizable composition according to claim 1, wherein (b) is a (meth) acrylic ester having two or more (meth) acryloyloxy groups in one molecule. 4. The reaction product according to claim 1, wherein said (a) is reacted at a ratio of 0.2 to 1.0 mol with respect to 1.0 mol of hydroxyl groups in said (b). Item 4. The polymerizable composition according to item 1, 2 or 3. 5. An ink varnish comprising the polymerizable composition according to any one of claims 1 to 4.