JPS61108618A - Curable resin composition - Google Patents

Abstract

PURPOSE:A resin composition which can forma cured film of excellent flexibility, comprising a lactone-modified epoxy (meth) acrylate resin and an ethylenically unsaturated bondcontaining vinyl compound. CONSTITUTION:The title composition comprising 5-95pts.wt. lactone-modified epoxy (meth) acrylate resin obtained by reacting part or all of the epoxy groups of a lactone-modified epoxy resin obtained by polymerizing by ring opening epsilon-caprolactone with 97-5pts.wt. hydroxyl group-containing epoxy resin [e.g., a diglycidyl ether of the formula (wherein n >=1)] with (meth) acrylic acid, 95-5pts.wt. ethylenically unsaturated bond-containing vinyl compound (e.g., trimethylolpropane triacrylate), and 0-10pts.wt. photosensitizer (e.g., benzyl dimethyl ketone). This resin composition can be cured by irradiation to form a cured film of excellent flexibility.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a resin composition that is cured by irradiation with radiation to provide a cured film with excellent flexibility.

[Conventional technology]

BACKGROUND ART Radiation-curable resin compositions that are cured by irradiation with radiation such as ultraviolet rays and electron beams have been developed and practically used in various applications such as printing, paint, and electrical insulation. Its advantages are: 1) It is solvent-free and low-pollution. ■Curing speed is extremely fast and product productivity is high. (2) Since it cures as a 100% solid content, the volume change before and after curing is extremely small. ■There is no heat loss through the material or thermal effects on the material. Various types of paints and adhesives have been developed for plastics, paper, wood, inorganic materials, etc. Radiation-curable paints, inks, adhesives, etc. with these characteristics exhibit excellent properties such as adhesion, water resistance, and heat resistance.

Epoxy (meth)acrylate resins, which are obtained by subjecting the epoxy groups of epoxy resins to a ring-opening reaction with acrylic acid or methacrylic acid, are widely used.

[Problem that the invention seeks to solve]

However, this commonly used epoxy (meth)acrylate resin has the disadvantage of being hard and brittle. For example, when used as ink for paper, cracks occur in the ink when the paper is bent. Furthermore, when used as a paint on a metal plate such as iron or aluminum, if the plate coated with the paint is bent, the coating will crack and cannot be processed.

[Means for solving problems]

Therefore, the present inventors conducted intensive research to improve these drawbacks of epoxy (meth)acrylate resin and further expand the possibilities of epoxy (meth)acrylate resin. As a result, 8-caprolactone modified epoxy resin ( By using lactone-modified epoxy (meth)acrylate resin obtained by reacting meth)acrylic acid, moderate flexibility is imparted and the viscosity is significantly reduced! In addition, a radiation-curable resin composition has been obtained which has excellent adhesion, water resistance, heat resistance, and extremely good flexibility.

That is, the present invention provides (A) an epoxy resin 97 containing hydroxyl groups.
In a lactone-modified epoxy resin obtained by reacting 3 to 95 parts by weight of ε-caprolactone with 5 parts by weight and ring-opening polymerization of ε-caprolactone to the hydroxyl group of the epoxy resin, all or a part of the epoxy group contains acrylic acid or 5 to 95 parts by weight of lactone-modified epoxy acrylate or lactone-modified epoxy methacrylate resin obtained by reacting methacrylic acid, (B) 95 to 5 parts by weight of a vinyl compound containing an ethylenically unsaturated bond, and (C) photoaggravation. The present invention provides a radiation-curable resin composition containing 0 to 10 parts by weight of a radiation-curing agent.

The modified epoxy (meth)acrylate resin of the present invention is 6-
Unlike the external plasticizing method in which a plasticizer is added in that caprolactone is added to all or part of the secondary hydroxyl groups of the epoxy resin to impart flexibility to the epoxy acrylate resin, the plasticizer bleed phenomenon is also avoided. In addition, since epoxy acrylate resins generally have high viscosity, it is necessary to use large amounts of low-boiling acrylic esters that are highly irritating to the skin as diluents. Since the modified epoxy acrylate resin of the invention has a low viscosity, it is possible to reduce the amount of diluents such as low-boiling acrylic esters that are highly irritating to the skin, which improves workability. .

The epoxy resin having a hydroxyl group used in the present invention is a diglycidyl ether having the following structure manufactured from epichlorohydrin and bisphenol A, or a diglycidyl ether having the following structure manufactured from epichlorohydrin and bisphenol F with n=1 or more or more. A diglycidyl ester synthesized from a basic acid and epichlorohydrin, etc. can be used.

8-Caprolactone is produced industrially by oxidizing cyclohexanone with peracid by Bayer-Billikar reaction. In the present invention, lactones or lactams other than ε-caprolactone can also be copolymerized.

The proportion of the epoxy resin in the lactone-modified epoxy resin used for producing the lactone-modified epoxy (meth)acrylate resin of the present invention is 97 to 5 parts by weight, preferably 95 to 30 parts by weight, out of a total of 100 parts by weight. The reason for this is that if the amount is too large, the desired sufficient flexibility cannot be obtained, whereas if the amount is too small, the resin becomes too soft.

The ring-opening polymerization of ε-caprolactone to the secondary hydroxyl group of the epoxy resin is carried out at 100-240°C, preferably at 120-240°C.
Perform at 0°C.

If the temperature is lower than 100°C, the reaction rate is low;
This is because if the temperature is higher than ℃, ε-caprolactone will boil and escape from the reaction system. It is preferable to use a catalyst for this reaction. Examples of catalysts include titanium compounds such as tetrabutyl titanate, tetrapropyl titanate, and tetraethyl titanate, organic tin compounds such as tin octylate, dibutyltin oxide, and dibutyltin laurate, and stannous chloride, stannous bromide, and stannous iodide. 1 tin or the like can be used.

In particular, when it is desired to obtain a product with a narrow molecular weight distribution, it is preferable to use stannous chloride.The amount used varies depending on the reaction temperature, but is generally 1000 ppa+ to 0.01 ppm.
, preferably 500 ppm to 0.2 ppm.

The reaction may be carried out without a solvent or in a solvent without active hydrogen such as toluene or xylene. However, solvents having ester bonds are generally not preferred. This is because, during the reaction, a transesterification reaction may occur with the ester group of polycaprolactone, resulting in the production of polycaprolactone that is not bonded to the epoxy resin.

When tin chloride is used as a catalyst, it is also possible to use an ester solvent since it hardly promotes the transesterification reaction. However, when using a titanium-based catalyst, it is particularly desirable to avoid ester-based solvents because they also promote the transesterification reaction.

The lactone-modified epoxy (meth)acrylate resin used in the present invention is prepared by combining the above-mentioned lactone-modified epoxy resin with acrylic acid or methacrylic acid in the presence or absence of a ring-opening catalyst for epoxy groups, and optionally using a polymerization inhibitor and a solvent. Alternatively, it is obtained by a heating reaction in the presence of a reactive diluent, and therefore, an unmodified hydroxyl group generated by ring opening of an epoxy group is always present.

In the curable resin composition of the present invention, 5 to 95 parts by weight, preferably 20 to 80 parts by weight of the lactone-modified epoxy (meth)acrylate resin obtained in this way is mixed with ethylenically unsaturated bonds. Vinyl compound 95-
5 parts by weight, preferably 80 to 20 parts by weight are added. If there is too little lactone-modified epoxy (meth)acrylate resin, it will not be possible to provide sufficient adhesion, heat resistance, and flexibility to the cured coating, and if there is too much, the viscosity will be high, making it difficult to handle or slowing down the curing speed. may be slow.

The vinyl compound having an ethylenically unsaturated bond used in the present invention refers to an acrylic ester or methacrylic ester compound represented by the general formula (I), a radically polymerizable vinyl compound represented by styrene, N-vinylpyrrolidone, etc. It is a low viscosity liquid compound with heavy bonds.

(I)

Monofunctional (meth)acrylic esters such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, acrylic ester of tetrahydrofurfuryl alcohol, phenoxyethyl acrylate, 1 Trifunctional (meth)acrylic acid esters such as 6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, propylene glycol diacrylate, propylene glycol dimethacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate , trifunctional (meth)acrylic esters such as pentaerythritol triacrylate, etc. are used.

These vinyl compounds having ethylenically unsaturated bonds may be used alone or in combination of two or more.

The term "radiation" in the present invention generates free radicals,
Refers to all radiation sources that induce addition polymerization of vinyl bonds. The actinic radiation preferably has a wavelength of 200 to 7,500 wavelengths, preferably 2,000 to 4,000 wavelengths.

The type of actinic radiation used here is ultraviolet light.

Other forms of actinic radiation include sunlight, from artificial light sources such as carbon arc lamps, and from mercury vapor melting. A preferred electron beam system is one in which a linear cathode emits a direct electron curtain.

The radiation-curable resin composition of the present invention may contain an effective amount of a photosensitizer when the composition is photocured. Usually this amount will be about 0.01-10%, preferably about 0.1-5% by weight of the resin composition.

These photosensitizers and their curing processes are well known in the art (
Are known. - Examples include: For example, benzophenone, acetophenone benzyl, benzyl dimethyl ketone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, dimethoxyacetophenone, jetoxyacetophenone, dimethoxyphenylacetophenone, diphenyl disulfide, α-alkylbenzoin, etc. be.

These photosensitizers can also contain synergists, such as tertiary amines, to enhance the conversion of light absorption energy into polymerization-initiating free radicals.

When this curable composition is cured by electron beam irradiation, it is not necessarily necessary to add a sensitizer.

The resin composition of the present invention may contain various other additives such as thermal polymerization inhibitors, surfactants, ultraviolet absorbers, matting agents, thixotropic agents, dyes, and pigments, as desired. Furthermore, various thermoplastic resins, thermosetting resins, etc. can also be blended.

The compositions of the present invention can be cured by applying them as a thin film onto a substrate. As a method for forming a thin film, spraying, brushing, dipping, roll coating, etc. are used. Curing is preferably carried out under an inert gas (for example, nitrogen gas) atmosphere, but it can also be cured under an air atmosphere.

The cured composition according to the present invention can be used for inks, plastic coatings,
Various coating fields such as paper printing, film coating, metal coating, furniture painting, ERP, lining, and many industries such as insulation panels, insulation sheets, laminates, printed circuit boards, resist inks, semiconductor encapsulants, etc. in the electronics field. It can be applied to various fields.

〔Example〕

The present invention will be explained in more detail in the following examples. In the example,
Parts represent parts by weight.

Synthesis Example 1 Araldye 6071 (trade name of epoxy resin manufactured by Ciba Co., Ltd., epoxy equivalent: 450-5
00) 930 parts, 0.54 parts of hydroquinone monomethyl ether as a polymerization inhibitor were charged, the reaction temperature was kept at 85±5°C while air was flowing, and 144 parts of acrylic acid and 1.07 parts of triethylamine as a catalyst were added in about 2 hours. dripped.

After the dropwise addition was completed, the reaction was carried out at about 90°C for about 24 hours, resulting in an acid value of 3.38 mgKOH/g and oxirane oxygen of 0.0.
A resin with a viscosity of about 2 million cp/25° C. was obtained.

Synthesis Example 2 900 parts of Araldite 6071, 100 parts of ε-caprolactone, 0.01 parts of tetrabutyl titanium) in a 4-tubular flask equipped with a nitrogen inlet tube, a thermometer, a cooling tube, and a stirring device.
By charging the same amount and reacting at 180°C for 5 hours,
A solid resin containing 0.3 wt.chi. of unreacted ε-caprolactone and an epoxy equivalent of 520 was obtained.

Next, 780.2 parts of the above lactone-modified epoxy resin and 0.44 parts of hydroquinone monomethyl ether were charged into the same apparatus as in the comparative example, and the reaction temperature was raised to 85% while blowing air.
While maintaining the temperature at ±5°C, 108 parts of acrylic acid and 0.44 parts of triethylamine were added dropwise over about 2 hours. Approximately 90 minutes after completion of dripping
By reacting at ℃ for about 24 hours, the acid value was 4.20m.
gKOH/g 1 oxirane oxygen 0.09%, viscosity approx. 1
A resin of 1,000,000 cp/25°C was obtained.

Synthesis Example 3 500 g of Araldite 6071 was placed in the same apparatus as Example 1.
0.01 parts of ε-caprolactone, 500 parts of ε-caprolactone, and 0.01 parts of tetrabutyl titanate) were reacted at 180°C for about 7 hours, thereby converting 0.4 wt χ of unreacted ε-caprolactone into
, a solid resin having an epoxy equivalent of 940 was obtained.

Next, 940 parts of the above lactone-modified epoxy resin and 0.0 parts of hydroquinone monomethyl ether were placed in the same equipment as in the comparative example.
Add 51 parts and raise the reaction temperature to 85±5 while blowing air.
72 parts of acrylic acid and 1.0 parts of triethylamine.
01 part was added dropwise over about 2 hours. By reacting at about 90°C for about 24 hours after the completion of the dropwise addition, the acid value was 3.51mgKO.
H/g, oxirane oxygen 0.05%, viscosity approximately 500,000c
A resin of p/25°C was obtained.

Example 1.2 50 parts each of the lactone-modified epoxy acrylate resins synthesized in Synthesis Examples 2 and 3, 30 parts of trimethylolpropane triacrylate (hereinafter abbreviated as TMPTA), 10 parts of pentaerythritol triac Utz-), and N −
10 parts of vinyl pyrrolidone (hereinafter abbreviated as MVP) and 2 parts of benzyldimethylkecool (Irugaki Air-651, manufactured by Ciba) as a photoinitiator were mixed, and the mixture was coated on an iron substrate to a thickness of 15 μm, and a high-pressure mercury lamp (output 80 W/cm) was cured at a belt speed of 1 m/min, and the physical properties of the coating film were evaluated.

Table-1 Examples 3 and 4 20 parts of TMPTA, 1.6-
20 parts of hexanediol diacrylate (hereinafter abbreviated as HDDA), 10 parts of NVP, and 2 parts of benzoin isobutyl ether were mixed, and the same evaluation as in Examples 1 and 2 was performed. The results are shown in Table 2.

Table 2 Examples 5 and 6 50 parts of the lactone-modified epoxy acrylate resin synthesized in Synthesis Examples 2 and 3, 20 parts of HDDA, 20 parts of dipentaerythritol hexaacrylate, 10 parts of MVP
Example 1
．． The same evaluation as in 4 was conducted.

The results are shown in Table 3.

Table 3 Comparative Examples 1 to 3 The epoxy acrylate resin synthesized in Synthesis Example 1 was used instead of the lactone-modified epoxy acrylate resin synthesized in Synthesis Example 2.3, and the other formulations were the same as in Example 1.3.5. The physical properties were evaluated according to the conditions and curing conditions. The results are shown in Table 4.

Table 4 As shown above, when the lactone-modified epoxy 7-acrylate resin was used, the flexibility was clearly improved.

Kaoru Defudai Gakoya

Claims (1)

[Scope of Claims] (A) 97 to 5 parts by weight of an epoxy resin having a hydroxyl group contains ε
- In a lactone-modified epoxy resin obtained by reacting 3 to 95 parts by weight of caprolactone and ring-opening polymerization of ε-caprolactone to the hydroxyl group of the epoxy resin, the epoxy resin is obtained by reacting all or part of the epoxy group with acrylic acid or methacrylic acid. 5 to 95 parts by weight of the lactone-modified epoxy acrylate or lactone-modified epoxy methacrylate resin and (B) a vinyl compound having an ethylenically unsaturated bond 95
5 parts by weight and (C) 0 to 10 parts by weight of a photosensitizer.