JPH06336518A - Production of epoxy acrylate containing finely particulate rubber dispersed therein - Google Patents

Abstract

PURPOSE:To obtain an epoxy acrylate which not only retains the chemical resistance, moisture resistance, toughness, and good surface curability inherent in conventional epoxy acrylates but also has temp.-independent high flexibility, peel strength, and impact resistance by dispersing fine rubber particles. CONSTITUTION:An epoxy resin is mixed with an unvulcanized liquid rubber incompatible therewith, and the mixture is stirred to disperse the rubber into the resin. A vulcanizing agent is added to a melt of the mixture with heating to vulcanize the rubber. (Meth)acrylic acid is further added to this mixture to cause the acid to add the epoxy groups with ring opening.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a particulate rubber-dispersed epoxy acrylate.

[0002]

2. Description of the Related Art Epoxy resins have high mechanical strength, excellent heat resistance and chemical resistance, and are widely used in the industrial world.
Taking advantage of this feature, an epoxy acrylate synthesized by a reaction between an epoxy group and a (meth) acrylic group of (meth) acrylic acid is used as an acrylic resin raw material.

These epoxy acrylates are superior in mechanical strength, adhesive strength, heat resistance, chemical resistance, and electrical properties to ordinary polyester acrylates and urethane acrylates, and have a rapid curing rate, and further react. Since the group is an acrylic group, various curing methods such as heat curing, redox curing, and UV curing can be used by utilizing the reactivity of the double bond.

[0004]

However, since the epoxy acrylate has characteristics close to those of the epoxy resin, the drawbacks thereof are lack of flexibility, low peeling property and low impact like epoxy resin.

On the other hand, in order to improve the lack of flexibility, low peelability and low impact resistance which are the drawbacks of epoxy resins, an incompatible liquid rubber is uniformly dispersed in the epoxy resin, and a vulcanizing agent is further added. Attention has been focused on a method of obtaining an epoxy resin containing fine vulcanized rubber by adding vulcanization and curing.

It is known that the epoxy resin obtained by this method is excellent in flexibility, and the releasability and impact resistance are remarkably improved without impairing the physical and chemical properties of the original epoxy resin. (Publication No. 63-10165).

However, in the case of imparting flexibility to the epoxy acrylate by adding a liquid rubber like the epoxy resin, the epoxy acrylate has a vulcanizing agent, especially an organic peroxide because the terminal reactive group is an acrylic group. On the other hand, it is unstable and a method of vulcanizing the liquid rubber in the composition unlike the epoxy resin cannot be adopted.

Further, if the unvulcanized liquid rubber remains in a dispersed state, it has a drawback that the mechanical strength and chemical properties of the cured product are severely deteriorated under various environments such as temperature.

[0009] Therefore, there is no method for obtaining a cured product of fine particle rubber type by stirring and mixing the rubber powder which has already been vulcanized, but this method has a limitation in the particle size of the rubber particles to be dispersed. It is difficult to stabilize the quality, such as uneven dispersion due to secondary aggregation of particles,
Further, there is a drawback that the workability and working environment are poor, such as handling of fine particle powder.

[0010]

Therefore, in the present invention, an unvulcanized liquid rubber which is incompatible with the epoxy resin is stirred and dispersed in an epoxy resin which is a precursor of an epoxy acrylate, and a vulcanizing agent is added in a heated state. In addition, it proposes a method for obtaining a fine particle rubber-dispersed epoxy acrylate by obtaining a fine particle vulcanized rubber-dispersed epoxy resin and further adding (meth) acrylic acid capable of reacting with the epoxy resin and reacting it.

The epoxy resin used in the present invention can be selected depending on the use of the epoxy acrylate as the final composition.

Further, since the reaction mechanism of the final composition, epoxy acrylate, is a radical reaction, it is not necessary for the epoxy resin to have two or more functional groups for the addition reaction. A glycidyl compound having one epoxy group is included, but considering the curability of the final composition, preferably a bifunctional epoxy resin such as a condensation product of epichlorohydrin and a polyhydric alcohol or a polyhydric phenol and bisphenol A, Cyclohexane oxide-based epoxy resin Epoxy resin derived from polymer or copolymer of di- or polyolefin Epoxy resin obtained by copolymerization of glycidyl methacrylate and vinyl compound and epoxy resin obtained from glyceride of highly unsaturated fatty acid Good.

Examples of the liquid rubber include urethane rubber, polysulfide rubber, butadiene rubber, acrylonitrile butadiene rubber, chloroprene rubber, isoprene rubber, styrene butadiene rubber, and the like. The condition is that there is no carbonyl group, amino group, or the like. This is because these functional groups can react with the epoxy groups, so that the equivalent weight of the epoxy resin decreases during vulcanization, and a sufficient epoxy acrylate cannot be obtained during acrylation.

In this case, any vulcanizing agent may be used as long as it can cure or crosslink the liquid rubber component. For example, sulfur compounds such as sulfur dichloride, morpholine disulfide and alkylphenol disulfide, Oximes such as p-quinone dioxime, tetrachloro-p-benzoquinone, p, p-dibenzoyldiquinone dioxime, poly-p-dinitrosobenzene, bis-
Nitroso-4-phenyl-1,4-piperazine, N-
Nitro compounds such as (2-methyl-2-nitropropyl) -4-nitrosoaniline, t-butyl peroxide, cumene hydrate topoxide, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide. 2,5-dimethyl-2,5-di (t-butylperoxo) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3,
1,3-bis (t-butylperoxyisopropyl) benzene, 1,1-bis (t-butylperoxy) -3,
3,5-trimethylcyclohexane, n-butyl-4,
4-bis (t-butylperoxy) valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, t
Examples thereof include organic peroxides such as -butyl peroxybenzoate, t-butyl peroxyisopropyl carbonate, and t-butyl perbenzoate.

These vulcanizing agents are those which satisfactorily crosslink or cure the liquid rubber, and which decompose when the epoxy resin is heated and stirred and have no effect on (meth) acrylic acid added thereafter. Therefore, organic peroxides are preferable.

In the production of the present invention, an epoxy resin is heated to 80 to 200 ° C., preferably 100 to 150 ° C. to be melted, and 0.5 to 60 parts by weight of an incompatible liquid rubber is added to the epoxy resin and heated. Stir.

For example, since the incompatible liquid rubber can be dispersed in the epoxy resin by stirring at a stirring speed of 1,000 to 10,000 rpm, a vulcanizing agent is added dropwise to this to vulcanize the liquid rubber. When obtained, a sea-island structure matrix in which 0.5 to 30μ of fine rubber particles are dispersed is obtained.

After the vulcanizing agent is added and the vulcanization of the rubber is completed, the excess vulcanizing agent is completely decomposed by heating and stirring for 1 hour.

When an epoxy resin mixture having fine particle rubber dispersed therein is obtained, (meth) acrylic acid is added to this mixture to effect ring-opening addition of (meth) acrylic acid to the epoxy groups contained therein.

The (meth) acrylic acid is added in an amount equivalent to or slightly more than the epoxy groups contained in the mixture, for example, 1.0 to 1.3 equivalents based on the epoxy groups, and triethylamine, triethylbenzylammonium chloride or hydroxylated as a catalyst. Potassium, N, N-benzylmethylamine, benzyltrimethylammonium hydroxide, etc. are added, and the epoxy resin is esterified by heating and stirring at 60 to 130 ° C for 5 hours to obtain an epoxy acrylate oligomer.

The epoxy acrylate thus obtained has the chemical resistance, moisture resistance, and
In addition to the characteristics of toughness and good surface curability, dispersion of fine particle rubber improves flexibility independent of temperature change,
Improved peel strength and impact resistance.

Further, this epoxy acrylate utilizes a terminal (meth) acrylic group to effect radiation curing, heat curing,
Various curing methods such as anaerobic curing and primer curing are possible.
At that time, the mixing and stirring of the reactive diluent monomer, the polymerization initiator and the like can be carried out continuously during the production of the acrylic oligomer, which enables very efficient production.

[0023]

EXAMPLES Examples of the present invention will be shown below. Example 1 (1) 190 g of bisphenol A type epoxy resin in a reaction vessel
Take and stir with a homogenizer at 2000-10000 rpm, 150
Raise the temperature to ℃.

(2) A liquid prepared by previously kneading 0.5 g of 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane [Perhexane 3M; manufactured by NOF CORPORATION] Add 20g of rubber (Hiker CTBN1300X8) and stir for 3 hours.

(3) Thereafter, this was cooled to 100 ° C., and 72 g of acrylic acid was added. When the liquid temperature reached 100 ° C, 1 g of reaction catalyst triethylbenzylammonium chloride was added.
The mixture is added, stirred at 100 ° C. for 5 hours, and then naturally cooled, and the obtained composition is used as composition A, and the following formulation examples and the formulation compositions of comparative examples are adjusted.

Formulation Example 1 (Photocurable) Composition A 80g 2-Hydroxymethacrylate 30g Photoinitiator (Irgacure-184) 2g

Formulation 2 (anaerobic curability) Composition A 60g 2-hydroxymethacrylate 40g cumene hydroperoxide 1g saccharin 3g

Comparative Example 1 Bisphenol A type epoxy acrylate 80 g 2-hydroxymethacrylate 30 g Photoinitiator (Irgacure 184) 2 g

Bisphenol A type epoxy acrylate 60 g 2-hydroxymethacrylate 40 g cumene hydroperoxide 1 g saccharin 3 g

With respect to Formulation Example 1 and Comparative Example 1, a photocured material physical property test was conducted under the following conditions, and the results are shown in Table 1 below. UV light intensity: 3000mJ / cm ² Irradiation from acrylic side Tension rate: 10mm / min

[0031]

[Table 1]

Result: The peel strength was improved while the Tg was almost maintained, and the adhesive strength was improved.

An anaerobic curing property test was conducted under the following conditions for Formulation Example 2 and Comparative Example 2, and the results are shown in Table 2 below. Laminated under a load of 3Kg and left as it is for 24 hours Pulling speed: 10mm / min

[0034]

[Table 2]

Results: Improvement of peel strength as with photocuring,
An improvement in adhesive strength was seen.

Batch Production Example A fine particle rubber-dispersed epoxy acrylate was synthesized according to the procedure (1) to (3) of Example 1, and acrylic acid was added and stirred for 5 hours:

(A) Without cooling, 2-hydroxymethacrylate and a photoinitiator (Irgacure 184) were added and stirred so as to have the same compounding ratio as in Compounding Example 1.

(B) Without cooling, 2-hydroxymethacrylate and saccharin were added in the same blending ratio as in Blending Example 2, heating and stirring were continued for 4 hours, then cooled to room temperature, and cumene hydroperoxide was added. To do.

The compositions obtained by the procedures of (a) and (b) have the same properties and physical properties as those of the compositions obtained in Formulation Examples 1 and 2, and are collectively used in the production of the fine particle rubber-dispersed acrylate oligomer. It was confirmed that the composition could be compounded.

[0040]

In summary, according to the present invention, in addition to the characteristics of conventional epoxy acrylates such as chemical resistance, moisture resistance, toughness and good surface curability, dispersion of fine particle rubber does not depend on temperature change. An epoxy acrylate having high flexibility, peel strength and impact resistance is obtained.

Further, by using the terminal (meth) acrylic group, an epoxy acrylate capable of various curing such as radiation curing, heat curing, anaerobic curing and primer curing can be obtained.

Claims (3)

[Claims] 1. An unvulcanized liquid rubber that is incompatible with the epoxy resin is stirred and dispersed in an epoxy resin, and a vulcanizing agent is added in a heat-melted state to vulcanize the liquid rubber. A method for producing a fine particle rubber-dispersed epoxy acrylate, which comprises adding (meth) acrylic acid and subjecting the epoxy group contained in the mixture to ring-opening addition of (meth) acrylic acid. 2. The production method according to claim 1, wherein the vulcanizing agent is an organic peroxide. 3. The method according to claim 1, wherein the liquid rubber is a liquid rubber which can be vulcanized or cured by an organic peroxide.