JPS5817525B2 - One-component curable composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a one-component curable composition with excellent storage stability containing a polymerizable acrylate and/or methacrylate (hereinafter abbreviated as (meth)acrylate).

Curable compositions containing polymerizable (meth)acrylate as a main component are widely used industrially as adhesives, sealants, coating agents, paints, molding materials, and the like.

When used in these applications, a curable composition containing (meth)acrylate as a main component is heated in the presence of a polymerization initiator and/or polymerization accelerator, irradiated with ultraviolet light, or heated at room temperature. A method of polymerizing by coexisting a redox catalyst is known.

A method of imparting polymerizability at room temperature to a composition containing polymerizable (meth)acrylate as a main component and creating a curable composition with excellent storage stability includes, for example, (1) blending an organic peroxide into the composition; A method of preparing a liquid containing a compound containing an organic peroxide and a compound that forms a redox system, and mixing or bringing these two liquids into contact when polymerization is desired; A method in which a mixed solution is prepared in advance, and when polymerization is desired, a compound that forms a redox system or a solution of the compound dissolved in an organic solvent is added and mixed, or ■ A redox system is formed with an organic peroxide in the composition. There is a method of preparing in advance a mixture of compounds to be polymerized, and then adding organic peroxide or a solution of it dissolved or dispersed in an organic solvent when polymerization is desired.These are conventional methods. be.

In each of these methods, there are two types of compositions, and operations such as measuring and mixing are required during polymerization, making handling complicated.

In order to solve this problem, the present inventors microcapsulated a polymerization catalyst and mixed it with (meth)acrylate, thereby making it possible to polymerize in a short time at room temperature while maintaining long-term storage stability at room temperature. God proposed a one-component curable composition and its improvement (Special Publication No. 51-40136, Special Publication No. 52-20194, Special Publication No. 53-5894, Special Publication No. 53-Sho.
-15734, Japanese Patent Publication No. 53-18079, etc.), but these are somewhat insufficient to meet higher demands regarding storage stability at room temperature or performance of cured products, such as adhesive strength when used as an adhesive. It is.

As a microencapsulation method, the aqueous coacervation method is usually the easiest and has various advantages, and is also applied to the microencapsulation of polymerization catalysts, but this method has little solubility in water. It is particularly suitable for microencapsulation of compounds that are not liquids and become particulates when stirred in an aqueous system.

Diacyl peroxide is one of the effective polymerization catalysts for curable compositions containing polymerizable (meth)acrylates, and it is made into a solution in an organic solvent and then microencapsulated by an aqueous coacervation method. However, benzoyl peroxide, p-chlorobenzoyl peroxide, 2.
Since diacyl peroxide such as 4-dichlorobenzoyl peroxide does not have sufficient solubility in organic solvents, the concentration of diacyl peroxide in the internal phase of microcapsules remains at a low concentration of about 20 wt% at most.

Therefore, in order to increase the polymerization rate of the curable composition, it is necessary to increase the amount of microcapsules containing diacyl peroxide as the internal phase, and as a result, the membrane material of the microcapsules and the internal phase must be increased. Constituent 4: For example, large amounts of organic solvents and the like are mixed into the cured product, which impairs the mechanical or electrical properties, adhesion, and surface smoothness of the cured product.

On the other hand, the m-)luoyl peroxide used in the present invention is more soluble in organic solvents than other diacyl peroxides, so the concentration in the internal phase material can be increased to 30 wt% or more, and the curable It is possible to obtain an excellent polymerization rate simply by incorporating a small amount of microcapsules into the composition, and the cured product produced by this curable composition has better mechanical, electrical properties, and adhesion than conventional ones. It becomes something.

The polymerizable component in the curable composition of the present invention is polymerizable (
One or a mixture of two or more meth)acrylates, or a mixture thereof with a radically polymerizable vinyl compound other than (meth)acrylate, such as (meth)acrylic acid, is used.

Specific examples of polymerizable (meth)acrylates that can be used include methyl (meth)acrylate, ethyl (meth)acrylate,
Acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 2- Hydroxyethyl (meth)acrylate, 2-
Hydroxypropyl (meth)acrylate, diethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, glycidyl (meth)acrylate, allyl (meth)acryle-I, 3-chloro-2
-Hydroxypropyl (meth)acrylate, 2-cyanoethyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, phenoxyethyl (meth)acryle-I, acetoxyethyl (meth)acrylate, methyl carpi Thor (
meth)acrylate, polyglopylene glycol mono(
Mono(meth)acrylates such as meth)acrylates;
Ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, 1,2-propylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, ■・4-butanediol di(meth)acrylate, ■・6-hexanethiol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(
Poly(meth)acrylate of polyols such as meth)acrylate and 1,2,6-hexanetrioltri(meth)acrylate; obtained by dehydration condensation polyesterification reaction using polybasic acid, polyol and (meth)acrylic acid as starting materials. Polyester poly(meth)acrylate, epoxy poly(meth)acrylate, diisocyanate, and glycol obtained by ring-opening addition reaction of epoxide using an epoxy compound having two or more epoxide groups in the molecule and (meth)acrylic acid as starting materials. There are also poly(meth)acrylates such as polyurethane poly(meth)acrylates obtained by condensation reaction using (meth)acrylates having hydroxyl groups in the molecule as starting materials.

A tertiary amine is used as a polymerization accelerator in the present invention.

Specific compounds include N-N-dimethylaniline, N-N-
Dimethyl para-toluidine, N-N-diethylaniline,
N-N-diethyl para-toluidine, N-N-di(β-hydroxyethyl)aniline, N-N-di(β-hydroxyethyl) para-toluidine, etc., and these can be cured as they are or in microencapsulation. It is blended into the composition.

Second, microcapsules containing m-4 luoyl peroxide as an internal phase are preferably produced using an aqueous coacervation method.
-Dissolving 20wt% or more of toluoyl peroxide,
Microcapsules are manufactured by using a polymer containing gelatin as a membrane material.

The particle size of the microcapsules is preferably in the range of 50 microns to 1000 microns, but is not limited to these ranges.

Some examples of the solubility of m-toluoyl peroxide at 20°C in water-insoluble organic solvents are benzene (
65wt%), toluene (58wt%), carbon tetrachloride (
45wt%), dimethyl phthalate (35wt%), styrene (58wt%), methyl methacrylate (53wt%)
), and in the present invention, in addition to these, xylene, anisole, dibutyl phthalate, trichlorethylene, tetrachlorethylene, methylchloroformo 8, ethylbenzene, cumene, methylbenzoate,
Solvents such as ethylbenzoate, chlorobenzene and 0-dichlorobenzene are preferably used.

These solvents may be used alone or in combination of two or more.

The microcapsules used in the present invention are suitably those whose inner phase is a water-insoluble organic solvent solution having a m-)luoyl peroxide concentration of 20 wt% to 80 wt%.
P2800457, USP2800458, USP35
31418, BP1117178, and the like.

The polymerizable (meth)acrylate contained in the curable composition of the present invention is 20 wt% to 95 wt%, and the amine that forms a redox system with diacyl peroxide is 0.1 to 95 wt%.
8 wt%, m-) The compounding amount of the luo oil peroxide microcapsules is preferably 1 to 20 wt%.

A polymerization inhibitor, ultraviolet inhibitor, antioxidant, etc. are usually added to a curable composition containing (meth)acrylate in order to maintain long-term storage stability, but the curable composition of the present invention also When these stabilizers are added, storage stability is further improved.

Furthermore, curable compositions containing (meth)acrylates have the property of inhibiting polymerization in the presence of air or oxygen; on the other hand, since these curable compositions are often used in air, For example, paraffin wax, organic metal salts, etc. are added for the purpose of improving the curing speed of the surface in contact with the curable composition, but it is also possible to incorporate these compounds into the curable composition of the present invention. It is.

Furthermore, for the purpose of improving the properties of the (meth)acrylate alone, it is also possible to prepare a composition in which, for example, polymers, inorganic fillers, etc. are dissolved or dispersed.

The one-component curable composition of the present invention has extremely good storage stability and excellent workability, and once the microcapsules are ruptured, a cured product can be formed in a short time. It is a composition.

Microcapsules can generally be ruptured by physical means such as pressurization.

Next, examples will be given to specifically explain the present invention.

All parts used in the examples are parts by weight.

Example 1 Microcapsules containing water-insoluble organic solvent solutions shown in MC-1 to MC-5 as internal phase were manufactured using British Patent No. 11171.
It was produced according to the method of Example 3 described in the specification of No. 78, with the particle size adjusted to 150μ to 450μ.

MC-1m-1 toluoyl peroxide 38 parts p-xylene 50 parts tetrachlorethylene 18 parts MC-2m-toluoyl peroxide 35 parts p-xylene 45 parts di-n-butyl phthalate 20 parts MC-3m-) Luoyl peroxide 30 parts Dimethyl dophthalate 70 parts MC-4m-) Luoyl peroxy 45 parts Dotoluene 50 parts Chlorobenzene 5 parts MC-5 Benzoyl peroxide 18 parts (25°C
(saturated concentration) anisole 82 parts (meth)acrylate or (meth)acrylate shown in Table 1
2 parts of N-N-dimethyl para-toluidine were blended with 100 parts of a composition in which a polymer was mixed and dissolved in acrylate, and further 5 parts of any of the above microcapsules were uniformly dispersed.

The curing rate and storage stability period of the obtained curable composition were measured.

The curing speed was measured by applying the curable composition to one of the two glass plates in a range of 2 crA in a constant temperature room at 23°C, stacking the other glass plate, and then applying the curable composition to one of the two glass plates. This was done by measuring the time it takes for the glass plate to stop moving by hand.

Note that after the glass plates were stacked, a load of 0.5 kg/crA was applied for the purpose of breaking the microcapsules.

In addition, the storage stability period is determined by examining the gelation time and deterioration time of the curable composition at 50°C (the point at which the curing time after a certain period of time is at least twice the initial curing time), and then at room temperature (25°C). After confirming that there is a correlation with
The storage period in °C was determined.

The flow measurement results are shown in Table 2 above, and when using microcapsules (MC-5) containing benzoyl peroxide as an internal phase material, the curing speed was slow;
Also, the shelf life is short.

Note that all of the 50°C storage periods shown in Table 2 are the results of measuring the deterioration time, and the gelation time was longer than the deterioration time, and there were no compositions that gelled before the deterioration time.

Example 2 The following three types of curable compositions (2-1, 2-2, 2-3)
was manufactured.

The number of microcapsules blended was as shown in Table 3.

Curable composition of 2-1 methyl methacrylate 60 parts 3-
Chloro-2-hydroxypropylmethacrylate 155 parts Toughlytetrimethylolpropane trimethacrylate 5 parts Unvulcanized rubber [NIpOI 20 manufactured by Nippon Zeon ■
Part 1072, l N-N-di(β-hydroxyethyl)pa 5 parts Tetruidine A microcapsule in which the internal phase of Example 1 is MC-2.

Curable composition of 2-2 Methoxyethyl methacrylate 70 parts Glycidyl methacrylate 10 parts Diethylene glycol dimethacrylate 2 parts Unvulcanized rubber [JSRN manufactured by Japan Synthetic Rubber 18 parts-230S] N-N-di(β-hydroxyethyl) A microcapsule in which the internal phase of 5 parts of toluidine Example 1 is MC-2.

Curable composition of 2-3 (comparative example) The types and amounts of other components were the same as those of curable composition 2, except that the microcapsules containing MC-5 of Example 1 as an internal phase substance were used. Composition that is the same as -2.

Using these curable compositions, the curing rate was measured according to the method described in Example 1, and the tensile shear adhesive strength and JIS K-68 were measured according to the method of JIS K-6350.
The impact adhesive strength was measured according to the method of No. 55.

The results are shown in Table-3. The material of the adherend used for the adhesive strength measurement was JIS G-4051 S-10C (iron).

Example 3 Microcapsules (MC-
6) and microcapsules (MC-7 and The example described in British Patent No. 1117178 (Exa
Particle size was adjusted to 100 to 300μ and produced according to the method of mple) 2.

The following two types of urethane (meth)acrylates were used as polymerizable (meth)acrylates.

Using 1 mol of urethane methacrylate'-tocoronate 4.048 (manufactured by Nippon Polyurethane) of 3-1 (manufactured by Nippon Polyurethane) and 10 mol of 2-hydroxyethyl methacrylate and a small amount of dibutyltin laurate as a catalyst, Product obtained by reacting for hours.

Using 1 mol of urethane acrylate coronate 4-048 (manufactured by Nippon Polyurethane) of 3-2 (manufactured by Nippon Polyurethane ■) and 10 mol of 2-hydroxyethyl acrylate based on the average molecular weight, a reaction was carried out at 60°C for 5 hours using a small amount of dibutyltin laurate as a catalyst. The product obtained by

Note that the products of 3-1 and 3-2 above are urethane (meth)
It is a mixture containing an excess of 2-hydroxy(meth)acrylate in addition to acrylate.

100 parts of any of these (meth)acrylates and N
3 parts of -N-diethyl para-toluidine and any of the above microcapsules were mixed.

When the curing speed of each composition was measured, a curable composition containing 5 parts of microcapsules MC-6 and a curable composition containing 10 parts of MC-7 (comparative example) showed the same curing speed. .

Using these curable compositions, a cured product with a thickness of 3 mm was molded by forcibly breaking the microcapsules.

Table 4 shows the results of measuring the tensile strength and elongation of this molded product.

Example 4 To 80 parts of diethylene glycol dimethacrylate, acrylic polymer [manufactured by Nippon Zeon ■, squid-4021] 2
Dissolve 0 parts of tertiary amine shown in Table 5 and add 5 parts of each
Parts were mixed.

Microcapsules MC-6 or MC-7 described in Example 3 were added to this mixture in various amounts, and the amount that gave a curing rate of 5 was determined, as shown in Table 5 below. In any composition containing any tertiary amine,
MC-7 required a higher loading than MC-6.

Example 5 A curable composition was prepared by mixing the following components.

Trimethylolpropane triacrylate 10 parts Lylate Tetrahydrofurfuryl methacrylate 55 parts 2-Hydroxypropyl methacrylate 10 parts Rate Methacrylic acid 5 parts Saturated polyester resin 71 20 parts Microencapsulated N-N-5 parts Dimethyl para-toluidine Example 1 Microcapsules with MC-1 as internal phase 5 parts Hydroquinone (polymerization inhibitor) 0.005 parts Paraffin wax with a melting point of 48 to 50°C 15 parts Tux*1 Pylon 500 manufactured by Toyobo ■2 N A mixture of 60 parts of -N-dimethyl para-toluidine and 740 parts of tetrachloroethyle was microencapsulated by a method similar to that described in Example 1.

This curable composition was applied onto a steel plate, and the microcapsules were broken with a roller to form a coating film of 100 microns, and the coating was cured to the surface after 25 minutes at room temperature.

Further, the above curable composition was placed in a polyethylene container, and a similar test was conducted after storage at room temperature for 6 months or 8 months, and as a result, the composition was hardened to the surface after 25 minutes and 30 minutes, respectively.

This composition did not gel during the storage period described above.

Claims (1)

[Claims] 1. A deep curable composition comprising the following (1), (2) and (3). (1) Polymerizable acrylate and/or methacrylate. (2) Microcapsules whose inner phase is a water-insoluble organic solvent solution containing 20 wt % or more of tertiary amine (3) m-)luoyl peroxide.