JPH05279435A - Active energy ray-curable composition - Google Patents

Abstract

PURPOSE:To provide the subject composition containing a resin component synthesized by reacting a carboxylic group-containing fluorocopolymer with a glycidyl group-containing vinyl monomer, curable in a very short time and capable of providing a cured material exhibiting a long-term stability even outdoors. CONSTITUTION:The objective composition contains a resin component synthesized by reacting (A) a carboxylic group-containing fluorocopolymer with (B) a glycidyl group-containing vinyl monomer (preferably glycidyl methacrylate), having a terminal unsaturated group-containing side chain and soluble in a solvent or a reactive diluent. As the component (A), a fluoroethylene-vinyl ether copolymer is preferable. The reaction between the components (A) and (B) is carried out by dissolving the component (A) in a solvent, subsequently adding the component (B) thereto, then further adding 1,8-diazabicyclo(5,4,0) undecene-7 as a catalyst and heating the resultant mixture at 100 deg.C for 5hr.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an active energy ray-curable composition.

[0002]

2. Description of the Related Art Metallic inorganic materials, plastics, wood,
A method of coating a paint to form a coating film has been used for a long time in order to impart a special function such as protection of the back surface of various base materials such as paper or water / oil repellency. As a method for effecting a coating film, an effect method by heating and an effect method by irradiation with active energy rays have been conventionally known. The latter has the advantage that the time required for the effect is shorter than that of the former, the occupation area of the coating line is small, and there is no limitation on the base material because heating is not required. It is widely used for the coating of base materials, and its application is also being actively studied in the fields of optical fiber coating, electronic parts, and special coatings such as electric wires.

The conventionally used active energy ray-curable composition is mainly composed of an oligomer component forming a skeleton of a coating film such as polyester, acrylic copolymer, polyurethane, epoxy polymer, silicone polymer and polyamide. As a polymerizable cross-linking site, it has a chain structure and has as a main component a polymer having an α, β-olefinic unsaturated bond at the terminal or side chain as a main component. It is composed of a functional or polyfunctional monomer.
These conventionally used active energy ray-curable compositions have a problem particularly in weather resistance, and none of them can withstand outdoor use sufficiently.

It is generally known that the performance of a coating film formed from a coating composition greatly differs depending on the structure of the skeleton-forming oligomer which is the main component. Therefore, it is considered that an active energy ray-curable composition having good weather resistance can be obtained by providing the skeleton-forming oligomer with a structure having good weather resistance.

As a coating composition having good weather resistance, a solvent-soluble fluoropolymer as described in JP-A-57-34107, JP-A-59-189108 and JP-A-60-67518 is used. A heat-curable coating composition is known in which a hydroxyl group contained in the coalescence is used to crosslink with an isocyanate or a melamine-based curing agent. Also,
JP-A-61-36374, JP-A-61-296073,
As disclosed in JP-A-62-25104, an isocyanate group having reactivity with a hydroxyl group contained in the fluoropolymer is reacted with a compound having an α, β-olefinic unsaturated group to cure with active energy rays. Methods for producing possible fluoropolymers are also known.

Further, as seen in JP-A-64-51418, a hydroxyl group-containing fluorocopolymer has a
A method using an unsaturated group-containing chloropolymer obtained by reacting an unsaturated carboxylic acid or its derivative is known.

[0007]

SUMMARY OF THE INVENTION An active energy ray-curable fluoropolymer obtained by reacting a conventional hydroxyl group-containing fluoropolymer with a compound having an isocyanate group and an α, β-unsaturated group is Because of its high viscosity,
There is a problem that a relatively large amount of diluent is required when it is used for applications such as paints. Normally, a system for performing active energy ray curing does not include a solvent removing step by heat for the purpose of shortening the step. Therefore, a reactive diluent (for example, a polyfunctional acrylate) is used as a diluent for the active energy ray curable coating material. When a large amount of this reactive diluent is used, there has been a problem that the weather resistance and elongation of the coating film, the adhesion to the substrate, etc. are reduced.

An unsaturated group-containing fluoropolymer obtained by reacting a hydroxyl group-containing fluoropolymer with an α, β-unsaturated carboxylic acid or a derivative thereof requires a high temperature or a long time for the reaction. There is a concern that the resin may become insoluble due to coloration or crosslinking, and when α, β-unsaturated carboxylic acid chloride is used as a modifier, its handling safety and removal of hydrogen dust produced as a result of the reaction If it is not performed sufficiently, there is a concern that it may affect rusting depending on the coating substrate.

[0009]

The present invention has been made to solve the above-mentioned problems, and the terminal obtained by reacting a fluorocopolymer having a carboxylic acid group with a vinyl monomer having a glycidyl group is unsatisfactory. Having a side chain that is a saturated group,
An active energy ray-curable composition comprising a resin component soluble in a solvent or a reactive diluent.

In the present invention, as the fluorocopolymer having a carboxylic acid group, a copolymer of fluoroolefin and another copolymerizable ethylenically unsaturated compound (hereinafter referred to as a copolymerizable monomer) is preferably adopted. .. As the fluoroolefin, a fluoroolefin having 2 to 3 carbon atoms such as tetrafluoroethylene, chlorotrifluoroethylene, vinylidene fluoride, and hexafluoropropylene is preferable,
Particularly, tetrafluoroethylene and chlorotriethylene are preferably used. The copolymerization ratio of this fluoroolefin is preferably about 30 to 70 mol%. If the proportion of fluoroolefin is larger than the above range, the solubility in a solvent or a reactive diluent becomes low, which is not preferable. On the other hand, when it is small, sufficient weather resistance cannot be obtained, which is not preferable.

As the copolymerizable monomer, vinyl ethers, allyl ethers, vinyl esters, (meth)
Acrylic monomer (in the present specification, the term “(meth) acrylic monomer” refers to an acryloyl group or a compound having an acryloyl group, and the term “(meth) acrylate” refers to an acrylic ester or a methacrylic ester. ), Olefins and the like. At least a part of these copolymerizable monomers needs to have a carboxylic acid group or a group that can be converted into a carboxylic acid group (hereinafter, collectively referred to as a functional group). In particular, it is preferable that the copolymerizable monomer having the functional group and the copolymerizable monomer having no functional group are used in combination.

When the proportion of the copolymerizable monomer is larger than the above range, the proportion of fluoroolefin becomes small,
It is not preferable because sufficient weather resistance cannot be obtained. Further, when the proportion of the copolymerizable monomer is small, the solubility in a solvent or a reactive diluent becomes small, which is not preferable. The copolymerization ratio of the copolymerizable monomer having the functional group and the copolymerizable monomer having no functional group is preferably about 1 to 45 mol% and 0 to 69 mol% based on the copolymer. ..

Here, as the copolymerizable monomer having no functional group, vinyl ethers having a linear, branched or alicyclic alkyl group or a fluoroalkyl group,
Examples include allyl ethers, vinyl esters, (meth) acrylates, olefins and the like. Preferably, at least one kind of vinyl ether having a linear, branched or alicyclic alkyl group having 1 to 10 carbon atoms, particularly 2 to 6 carbon atoms, or at least one kind of this vinyl ether and another functional group is contained. It is a combined use with a non-copolymerizable monomer. Here, preferable vinyl ethers include ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, cyclohexyl vinyl ether, 2,2,3.
3-tetrafluoropropyl vinyl ether etc. are illustrated.

As the copolymerizable monomer having a functional group, a hydroxyalkyl vinyl ether having a hydroxyl group, a hydroxyalkyl vinyl ester, a hydroxyalkyl (meth) acrylate, a carboxyalkyl vinyl ether having a carboxyl group, a carboxyalkyl vinyl ester, Carboxyalkyl (meth) acrylate, etc. Epoxy group-containing glycidyl vinyl ether, glycidyl vinyl ester, glycidyl (meth) acrylate, etc. Isocyanate group-containing isocyanate alkyl vinyl ether, isocyanate alkyl vinyl ester, isocyanate alkyl (meth) acrylate, etc. Having aminoalkyl vinyl ether, aminoalkyl vinyl ester, aminoalkyl Such as Le (meth) acrylate.

Further, the copolymerizable monomer may be a compound having a high molecular weight side chain as described later. In particular,
For example, there is a hydroxyl group-containing monomer obtained by adding a lactone compound or an alkylene oxide to the above-mentioned monomer having a hydroxyalkyl group.

When only a copolymerizable monomer having a functional group other than a carboxylic acid group is used as a monomer having a functional group, an appropriate method (for example, acid anhydride such as succinic anhydride or hexahydrophthalic anhydride in the hydroxyl group) is used. It is necessary to introduce a carboxylic acid group by reacting a substance).

By reacting the fluorocopolymer having a carboxylic acid group obtained as described above with a vinyl monomer having a glycidyl group, the terminal has a side chain having an unsaturated group, and a solvent or reactivity is obtained. A resin component soluble in the diluent can be obtained. Examples of the vinyl monomer having a glycidyl group include glycidyl methacrylate and allyl glycidyl ether. In particular, it is preferable to employ glycidyl methacrylate in terms of balance with the excellent weather resistance of the fluororesin. For the same reason, it is preferable to use a fluoroethylene-vinyl ether copolymer as the fluorocopolymer.

A fluorocopolymer having a carboxylic acid group,
The reaction method of the vinyl monomer having a glycidyl group is not particularly limited. However, usually, a fluorocopolymer having a carboxylic acid group is dissolved in a solvent or a reactive diluent, a vinyl monomer having a glycidyl group is added thereto, and a reaction catalyst such as dimethylaminoethanol is further added, and the mixture is stirred at 115 ° C. It can be obtained by reacting at 10 ° C. for 10 hours, and preferably DBU (1,8-diaza-bicyclo (5,4,0) undecene-7) or an organic acid salt thereof is reacted at 100 ° C. for 5 hours. By doing so, it is possible to reduce reactive diluent polymerization as a side reaction and coloring due to heating.

As the specific fluoropolymer in the present invention, a polymer having an intrinsic viscosity measured in tetrahydrofuran at 30 ° C. of 0.01 to 2.0 dl / g in an uncured state is preferably adopted.

The composition of the present invention contains an active energy ray curing initiator in addition to the above specific fluoropolymer except when it is not particularly required as in the electron beam curing coating composition.
As such an active energy ray curing initiator, for example,
Photo-curing initiator, specifically, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoisopropyl ether, benzoin isobutyl ether, 2
-Methylbenzoin, benzophenone, Michler's ketone, benzyl, benzyldimethylketal, benzyldiethylketal, anthraquinone, methylanthraquinone, 2,2-diethoxyacetophenone, 2-methylthioxanthone, 2-isopropylthioxanthone, 2-
Chlorothioxanthone, anthracene, 1,1-dichloroacetophenone, methylorthobenzoylbenzoate and the like can be mentioned.

The compounding amount of the active energy ray curing initiator is
About 0.1 to 10 parts by weight, particularly about 0.5 to 7 parts by weight, is preferably employed per 100 parts by weight of the cured body forming component. When the amount of the active energy ray curing initiator is too small, the curing time becomes long, which is not preferable, and when it is too large, problems such as yellowing of the cured body may occur, which is not preferable. Further, here, the cured body-forming component is
It is a component that gives a cured product by the action of active energy rays. When it contains an unsaturated group-containing fluoropolymer, and further contains a reactive diluent or a fluoroalkyl group-containing (meth) acrylate monomer described later, these also form a cured product. Included in the ingredients. However, those that do not form a cured product due to the action of active energy rays such as dissolution are not included in the cured product forming components.

Further, the composition of the present invention is
A solvent, a diluent or the like may be contained to reduce the viscosity. Examples of the solvent include aromatic hydrocarbons such as xylene and toluene, esters such as ethyl acetate and butyl acetate, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, and glycol ethers such as ethyl cellosolve. .. Further, as the reactive diluent, it is preferable to use a reactive diluent which can be polymerized by the active energy because it can prevent bubbles and blisters since volatilization at the time of curing does not occur. Examples of such reactive diluents include monofunctional or polyfunctional (meth) acrylic monomers. The (meth) acrylic monomer may include a special (meth) acrylic monomer such as a fluoroalkyl group-containing (meth) acrylate monomer that imparts water and oil repellency and low refractive index.

The reactive diluent may be any of the commonly known general-purpose (meth) acrylates and special (meth) acrylates, and may be a mixture of two or more. As the polyfunctional (meth) acrylate monomer, a compound in which a hydroxyl group of a compound such as diol or triol is replaced with a (meth) acrylate group is generally known. Specifically, 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate
Acrylate, 1,5-hexanediol (meth) acrylate, diethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate,
Examples thereof include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, and dipentaerythritol hexa (meth) acrylate. Among these, those having a low viscosity are particularly preferable.

Fluoroalkyl group-containing (meth) acrylate monomers have the general formula CH2 = CRCOOCmH2mCnF2nX
(In the formula, R is a hydrogen atom or a methyl group, m is an integer of 1 to 10, n is an integer of 1 to 21, and X is a hydrogen atom or a fluorine atom). , CH2 = CRCOOCH2CH2 (CF2) 2H CH2 = CRCOOCH2CH2CF2H CH2 = CRCOOCH2C3F6H CH2 = CRCOOCH2 (CF2CF2) 2H CH2 = CRCOOCH2 (CF2CF2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH3CH2 = CRCOOCH2CH2 3CF (CF3) 2 CH2 = CRCOOCH2CH2C10F21 CH2 = CRCOOCH2CH2 (CF2) 6H etc. can be shown. The above substances can be used alone or in combination of two or more.

In the present invention, when a reactive diluent is used, the proportion of the specific fluoropolymer and the monofunctional or polyfunctional (meth) acrylate are 1 to 98/1 to 98, respectively.
/ 1 to 98 (parts by weight), especially 20 to 60/10
It is preferably blended in a ratio of 40/10 to 40 (polymerized part).

[0026]

When the composition of the present invention is blended with another composition, it migrates to the continuous phase in a relatively large amount when the surface of the cured product or the cured product causes microscopic phase separation due to its fluorine-containing property. In addition, by curing and becoming a monomer integrally, the original durability and weather resistance are exhibited, and it becomes possible to effectively protect the cured body component and the body to be protected by it.

The composition of the present invention may contain various additives in addition to the compounds described above. Examples of such additives include leveling agents, viscosity modifiers, light stabilizers, moisture absorbers, pigments, dyes, reinforcing agents and the like. The blending amount of these additives is appropriately determined according to the purpose.

The composition of the present invention can be cured by active energies (eg, ultraviolet rays, electron beams, γ rays, etc.).

[0029]

EXAMPLES Synthesis Example 1 (Synthesis of Fluorocopolymer Having Carboxylic Acid Group) According to the method of Example 1 of JP-A-57-34107, a polymer was produced with the following two types of monomer compositions, and The following hydroxyl number average molecular weight was obtained. Next, 10 ppm by weight of triethylamine was added as a catalyst to each of them and the required amount of cobacic anhydride or hexahydrophthalic anhydride and each polymer resin, and the mixture was stirred at 65 ° C. for 5 hours to obtain a fluorocarbon having a carboxylic acid group. A copolymer was obtained. This is shown in Table 1.

[0030]

[Table 1]

In Table 1, CTFE is chlorotrifluoroethylene, HBVE is hydroxybutyl vinyl ether, CHVE is cyclohexyl vinyl ether, and EVE.
Is ethyl vinyl ether, TFE is tetrafluoroethylene, and HHPA is hexahydrophthalic anhydride.

Synthetic Example 2 (Synthesis of Fluorocopolymer Having Side Chain with Unsaturated Group) The fluorocopolymer having a carboxylic acid group produced in Synthetic Example 1 is equimolar to the acid value. (Glucidylmethacrylate) is added, and 0.1% by weight of DBU is added to the fluorocopolymer as a catalyst.
The mixture was heated and stirred for a period of time to obtain a fluorocopolymer having a side chain with an unsaturated group at the terminal. In the reaction, the fluorocopolymer can be dissolved in a solvent and reacted and then replaced with each monomer of the curable composition. However, in this synthesis example, the fluorocopolymer having a carboxylic acid group and GMA are formed. Synthesis was carried out in a state of being dissolved in a monomer composition as shown in Table 2 with respect to 100 parts by weight of the copolymer. By infrared analysis, the disappearance of the peak of the carboxylic acid group was confirmed by the reaction.

[0033]

[Table 2]

In Table 2, FA is CH2 = CHCOOCH2CH2C9
F19, CHMA is cyclolohexyl methacrylate), TMPMA is trimethyl propanol methacrylate, THFA is tetrahydrofuran acrylate,
TMP3A is trimethylpropane triacrylate.

Examples 1 to 4 Compositions of B1 to B4 synthesized in Synthesis Example 2 and a fluorocopolymer having a side chain having an unsaturated group at the terminal and a monomer composition were directly applied on a steel sheet as an electron beam curing coating composition. It was applied in a thickness of 30 μm, and irradiated with an electron beam under the irradiation conditions of an acceleration voltage of 300 KV, a current density of 7 mA and a dose rate of 3 Mrad / sec to obtain a cured product.

Examples 5 to 8 To 100 parts by weight of the composition B-2 synthesized in Synthesis Example 2 was added 3 parts by weight of Darocur (Merck Japan KK) 1173 as a photopolymerization initiator to prepare an ultraviolet-curable coating composition. The same applies to B-3 and B-4. To 50 parts by weight of B-2, 50 parts by weight of an epoxy acrylate oligomer manufactured by VISCOAT 540 (Osaka Organic Chemical Industry Co., Ltd.) was added and the same procedure was carried out to prepare an ultraviolet-curable coating composition part.

This coating composition was applied to a film applicator, allowed to stand at room temperature for 1 minute, and then applied on a steel plate in a thickness of 30 μ, and irradiated with ultraviolet rays at room temperature from a height of 20 cm with a 2 KW high pressure mercury lamp. The results of the following evaluations of the coating film after curing are shown in Table 3.

Finger touch dryness: Judgment of presence or absence of stickiness after 90 seconds of ultraviolet ray irradiation or electron beam irradiation according to JIS K5400 ○: None, ×: Yes

Weather resistance: Judgment of appearance abnormality after 2000 hour exposure of sunshine weatherometer of coating film ○: None, ×: Yes

Chemical resistance: Xylol rubbing test of coating film Judgment: Pass 200 times or more Poor: 200 times or less

Salt spray test: 500 hours Salt spray test of coating film (JIS K5400) Judgment: No rusting X: Rusting

Comparative Examples 1 to 3 Table 3 shows the evaluation results of coating films obtained in the same manner as in Examples 1 to 10 except that the unsaturated group-containing fluoropolymer was replaced by the commercially available acrylate oligomer shown in Table 5. It was

[0043]

[Table 3]

In Table 3, UAS-10 is a urethane acrylic oligomer manufactured by Sanyo Pulp Co., viscoat 540 is an epoxy acrylate oligomer manufactured by Osaka Organic Chemical Industry, and biscoat 851 is a urethane acrylate oligomer manufactured by Osaka Organic Chemical Industry.

[0045]

INDUSTRIAL APPLICABILITY The composition of the present invention is extremely excellent in curability due to active energy rays, and also has a monofunctional or polyfunctional (meth) acrylate-based monomer and a (meth) acrylic-based monomer having a fluoroalkyl group. It has excellent compatibility with the monomer, and further has curing such as giving a cured product having excellent weather resistance and chemical resistance. Further, the unsaturated group-containing fluoropolymer in the present invention has a relatively low viscosity,
When it is used as a coating composition, it has excellent coatability and can use a small amount of a diluent, so the weather resistance of the coating film, the adhesion to the substrate, the elongation, etc. are particularly excellent. As a synthesizing method, it does not produce rusting by-products such as acids, so it is also effective as a rust preventive paint.The reaction between a fluorocopolymer having a carboxylic acid group and a monomer having a glycidyl group is an optimum catalyst. It is possible to obtain a resin with little coloration without requiring high temperature due to various selections.

Further, due to the surface migration property of fluorine, there is a feature that the deterioration of weather resistance is small even if other oligomers or monomers are blended.

Since the composition of the present invention having these excellent curability can be cured in an extremely short time, it is possible to reduce the size of the cured product production line and mass production in a short time. It will be possible. Further, a cured product that is stable for a long period of time even when exposed to chemicals or outdoors is obtained. Further, since the compatibility with the (meth) acrylate-based monomer having a fluoroalkyl group is excellent, it is possible to mix a large amount of the fluoroacrylate-based monomer even in applications where a low refractive index and water / oil repellency are required. Also, at that time, there is an effect that a good cured product can be obtained.

Claims (1)

[Claims] 1. A fluorocopolymer having a carboxylic acid group and a vinyl monomer having a glycidyl group are reacted with each other to have a side chain having an unsaturated group, which is soluble in a solvent or a reactive diluent. An active energy ray-curable composition comprising a resin component.