JPH04353503A - Curable composition and production thereof - Google Patents

Abstract

PURPOSE:To provide the title low-viscosity composition for e.g. coatings of low shrinkability and good in adherability and heat resistance, comprising an inorganic substance and a (meth)acrylate prepared by reaction between (meth) acrylic acid, etc., and an alcohol in the presence of a copper compound. CONSTITUTION:(A) An inorganic substance (e.g. talc) is mixed with (B) a (meth) acrylate [e.g. trimethylolpropane tri(meth)acrylate] prepared by reaction between (1) (meth)acrylic acid and/or a (meth)acrylic ester and (2) an alcohol (e.g. trimethylolpropane) in the presence of p-toluenesulfonic acid as a catalyst and a copper compound such as cuprous oxide a polymerization inhibitor, into a slurry, thus obtaining the objective composition.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a curable composition that can be cured by ultraviolet rays or heat, and is used in paints, inks, adhesives, polymer concrete, etc., and is particularly suitable for use in resist inks, and a method for producing the same. It is related to.

0002

2. Description of the Related Art Generally, a curable composition is composed of a reactive prepolymer, an inorganic substance such as an inorganic filler or pigment, a reactive diluent, a polymerization initiator, and the like.

The above-mentioned inorganic substances are blended to improve physical properties such as low shrinkage, adhesion, heat resistance, and corrosion resistance, and to reduce costs, and it is usually preferable to add as much as possible. However, adding a large amount of inorganic material increases the viscosity of the curable composition, making it extremely difficult to handle. Therefore, conventionally, in order to lower the viscosity of curable compositions,
Although the molecular structure of resins (reactive prepolymers, reactive diluents), the shape of inorganic substances, particle size, particle size distribution, etc. have been investigated, satisfactory results have not yet been obtained.

[0004]The viscosity of the curable composition is adjusted by the above-mentioned reactive diluent so that it has an optimum viscosity depending on the intended use. Usually, (meth)acrylate is used as a reactive diluent for curable compositions.

[0005] In order to increase the amount of inorganic substances in the curable composition, it is desirable that the reactive diluent has a low viscosity or a high dilutability. However, in general, those with low viscosity have a small number of functional groups and are inferior in reactivity, which reduces the curing speed of the curable composition, while those with a large number of functional groups and high reactivity have a large molecular weight and high viscosity. It becomes less effective as a diluent. Therefore, conventionally, the viscosity of the curable composition has been adjusted by using a low-viscosity composition with a small number of functional groups and a high-reactivity composition with a large number of functional groups in combination.

[0006]

[Problem to be solved by the invention] Therefore, although there is a demand for (meth)acrylates with high reactivity, low viscosity, or high dilutability, such (meth)acrylates have not yet been obtained. It is.

The present invention has been made in view of the above, and its object is to provide a curable composition that can achieve low viscosity using (meth)acrylate with high dilutability, and a method for producing the same.

[0008]

[Means for Solving the Problems] As a result of various studies to solve the above problems, we have found that the viscosity of the curable composition depends not only on the type of reactive diluent contained therein, but also on the viscosity of the curable composition.
We found that it is greatly influenced by the manufacturing method,
The present invention has been completed.

That is, the present invention provides a method for producing a curable composition comprising an inorganic substance and (meth)acrylate as essential components, in which (meth)acrylic acid and/or (meth)acrylate is used as the (meth)acrylate. A method for producing a curable composition, the gist of which is to use a (meth)acrylate obtained by reacting an acrylic acid ester and an alcohol in the presence of a copper compound, and the curable composition obtained by the above production method. It is a composition.

To explain in more detail, (meth)acrylate is produced by dehydrating esterification of acrylic acid or methacrylic acid (hereinafter referred to as (meth)acrylic acid) with alcohol in the presence of a catalyst and a polymerization inhibitor, or It is produced by transesterification reaction between ester or methacrylic ester (hereinafter referred to as (meth)acrylic ester) and alcohol. If purification is necessary, it is preferable to purify by extraction or adsorption, as distillation may not achieve the purpose of the present application.

Examples of the esterification catalyst include commonly used sulfuric acid, sulfonic acids, phosphoric acid, boron trifluoride, and cationic ion exchange resins.

A copper compound is used as the polymerization inhibitor in the present invention. Examples of the copper compound include metallic copper, copper oxides, sulfides, hydroxides, ammonia complexes, sulfates, halides, carbonates, phosphates, and carboxylates, such as copper powder, Cuprous oxide, cupric oxide, cuprous sulfide, cupric sulfide, cuprous sulfate, cupric sulfate, cuprous chloride,
Cupric chloride, cuprous bromide, cupric bromide, cupric hydroxide,
Basic copper chloride, basic copper carbonate, cupric phosphate, cuprous cyanide, copper thiocyanate, copper acetate, basic copper acetate, copper formate, copper oxalate, copper citrate, copper tartrate, acrylic acid Examples include copper, copper methacrylate, copper naphthenate, copper phthalate, cupric ammonium chloride, copper phthalocyanine, copper dimethyldithiocarbamate, copper dibutyldithiocarbamate, and two or more of these may be used in combination. Further, commonly used polymerization inhibitors such as phenolic compounds such as hydroquinone and hydroquinone monomethyl ether, amine compounds such as phenylenediamine and phenothiazine, nitro compounds, and sulfur compounds may be used in combination.

A preferable amount of the copper compound to be used is 0.000 to (meth)acrylic acid or (meth)acrylic ester.
01 to 5% by weight, more preferably 0.05 to 0.5% by weight.

As the (meth)acrylate, monofunctional and polyfunctional (meth)acrylates can be used, and examples of the monofunctional (meth)acrylate include benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, and ethoxydiethylene glycol (meth)acrylate. Acrylate, tetrahydrofurfuryl (meth)acrylate, dicyclopentenyl (meth)acrylate, etc.
As meth)acrylate, ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate
Acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6 hexanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri( meth) acrylate, pentaerythritol tri(
Examples include meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and 2,2-bis[4-((meth)acryloyloxydiethoxy)phenyl]propane. The preferred range of the amount of (meth)acrylate used is 5 to 95% by weight based on the curable composition.

Examples of inorganic substances include inorganic fillers and pigments, which can be widely used such as talc, clay, silica, calcium carbonate, barium sulfate, calcium sulfate, mica, glass beads, cement, asbestos, kaolin, and carbon black. . Further, the shape thereof may be any shape as long as it can be dispersed in (meth)acrylate, and it may be in any shape such as powder or fiber. The amount of the inorganic substance used is preferably in the range of 5 to 90% by weight based on the curable composition.

[0016] In addition, various polymers,
Prepolymers, oligomers, polymerization initiators, stabilizers, surfactants, leveling agents, antistatic agents, pigments, and dyestuffs can be added to the curable composition, and a suitable range of their usage is determined according to the curable composition. It is 90% by weight or less based on the weight of the product.

[0017]

[Examples] In order to explain the present invention more specifically, the present invention will be explained in detail by giving Examples and Comparative Examples, but the present invention is not limited to these Examples.

``Example 1'' In a 1 liter four-necked flask equipped with a stirrer, a water separator with a cooling tube, a thermometer, and an air blowing tube, 201.3 g of trimethylolpropane and 389.1 g of acrylic acid were added as a solvent. Toluene 265.
5g, p-toluenesulfonic acid 36.2g as a catalyst,
0.4 g of cuprous oxide as a polymerization inhibitor was weighed out, and the produced water/toluene was distilled off at a pressure of 230 Torr under air blowing. The separated toluene was refluxed and reacted for 8 hours. The reaction temperature at this time was 70 to 85°C.

Next, the above reaction solution was transferred to a separating funnel, and 623.5 g of toluene was added, followed by 500 g of water and then 4%
It was washed with 1100 g of NaOH water and further with 500 g of water. After that, the toluene layer was passed through a strongly acidic ion exchange resin (Dowex HCR-W2H), and hydroquinone monomethyl ether was adjusted to 100 ppm as a polymerization inhibitor, and the toluene was removed under reduced pressure to produce a yield of 417.8 g and a viscosity of 84 cps. A pale yellow transparent liquid trimethylolpropane triacrylate (hereinafter referred to as TMPTA) was obtained at 25° C. (yield: 94%). In addition, the obtained TMPTA
The Cu content therein was 0.1 ppm or less.

[0020] Thereafter, 80.0 g of the obtained TMPTA and 20.0 g of talc as an inorganic substance were mixed and stirred for 5 minutes at 5000 rpm using a homodisper. Then, after leaving it for 1 hour in a constant temperature bath at 25°C, the above T
The viscosity of the slurry composition consisting of MPTA and talc was measured and was found to be 900 cps/25°C.

Examples 2 to 10 The same operations as in Example 1 were carried out under the same conditions except that the copper compounds shown in Table 1 below were used as polymerization inhibitors. Table 1 shows the physical properties (viscosity and residual polymerization inhibitor content) of the TMPTA thus obtained and the viscosity of the slurry composition composed of TMPTA and talc.

"Comparative Examples 1 to 3" Table 1 below as a polymerization inhibitor
The same operation as in Example 1 was carried out with all other conditions being the same except for using the substances shown in . As a result, the physical properties (viscosity and residual polymerization inhibitor content) of the obtained TMPTA,
Table 1 shows the viscosity of this slurry composition consisting of TMPTA and talc.

[0023]

[Table 1]

[Examples 11 to 13] In Example 11, 402.9 g of methacrylic acid and 174 g of trimethylolpropane were used.
．． In Example 12, 345.9 g of acrylic acid and 236.4 g of 1,6 hexanediol were charged, and in Example 13, 233.5 g of acrylic acid and 362.2 g of ethoxydiethylene glycol were charged, all other conditions being the same. The same operation as in Example 1 was performed. Note that the Cu content in the obtained (meth)acrylate was 0.1 ppm or less.

Further, Table 2 shows the viscosity of the obtained (meth)acrylate and the viscosity of the slurry composition composed of this (meth)acrylate and talc.

Comparative Examples 4 to 6 Using 0.4 g of hydroquinone as a polymerization inhibitor and keeping all other conditions the same, Comparative Example 4 was the same as Example 11, Comparative Example 5 was the same as Example 12, and Comparative Example 5 was the same as Example 12. In Example 6, the same operation as in Example 13 was performed. In addition, the hydroquinone content in the obtained (meth)acrylate is 1
It was less than ppm.

Further, Table 2 shows the viscosity of the obtained (meth)acrylate and the viscosity of the slurry composition composed of this (meth)acrylate and talc.

"Example 14" First, methyl acrylate 4
64.7g, 201.3g of trimethylolpropane, 7.3g of sulfuric acid as a catalyst, 0 cuprous oxide as a polymerization inhibitor
．． 4 g was charged and the reaction was carried out by transesterification. Note that the methanol produced in the above reaction was removed by azeotropy with methyl acrylate.

Next, after removing excess methyl acrylate under reduced pressure, the mixture was diluted with 890 g of toluene, and the same purification operation as in Example 1 was performed to obtain TMPTA. Note that the Cu content in the obtained TMPTA was 0.1 ppm or less.

After that, the same operation as in Example 1 was carried out, and T
The viscosity of a slurry composition consisting of MPTA and talc was measured. The results are shown in Table 2 along with the viscosity of TMPTA.

Comparative Example 7 The same operation as in Example 14 was carried out under the same conditions except that 0.4 g of hydroquinone was used as a polymerization inhibitor. Furthermore, the obtained TMP
The hydroquinone content in TA was 1 ppm or less.

Further, Table 2 shows the viscosity of the obtained TMPTA and the viscosity of the slurry composition composed of this TMPTA and talc.

``Example 15'' The same operation as in Example 1 was carried out under all other conditions, except that calcium carbonate was used instead of talc as the inorganic substance. Also, TMP
Table 2 shows the viscosity of the slurry composition composed of TA and calcium carbonate.

Comparative Example 8 The same operation as in Example 15 was carried out under the same conditions except that 0.4 g of hydroquinone was used as the polymerization inhibitor. Furthermore, the obtained TMP
The hydroquinone content in TA was 1 ppm or less.

Further, Table 2 shows the viscosity of the obtained TMPTA and the viscosity of the slurry composition composed of this TMPTA and calcium carbonate.

[0036]

[Table 2]

As can be seen from the above Examples 1 to 15 and Comparative Examples 1 to 8, there were cases in which a copper compound was used as a polymerization inhibitor for dehydration esterification or transesterification, and cases in which something other than a copper compound was used. Even when compared with the (meth)acrylate obtained, no differences were observed in terms of the obtained (meth)acrylate itself, appearance, or physical properties. The residual polymerization inhibitor content is 1 ppm or less). However, as is clear from a comparison of the viscosities of the slurry-like compositions made of the obtained (meth)acrylate and inorganic substance, the (meth)acrylate produced using a copper compound exhibits higher dilutability. ing. This shows that (meth)acrylate produced by dehydration esterification or transesterification using a copper compound as a polymerization inhibitor has excellent dilutability with respect to inorganic substances.

[0038] Here, one method for synthesizing the reactive prepolymer used in the photocurable composition is shown in Synthesis Example 1 below.

"Synthesis Example 1" Epoxy equivalent weight 180-200
Pisphenol A type epoxy resin (ARALDIT
EGY250 CIBA-GEIGY) 173
g, 70 g of acrylic acid, and 1.2 g of diethylaminoethyl methacrylate were placed in a flask equipped with a stirrer and a thermometer, and reacted at 80 to 100°C. When the acid value reached 1.9, the mixture was cooled and a light yellow color was obtained. Transparent liquid (15000ps
/25°C) was obtained.

``Example 16'' and ``Comparative Examples 9 to 11'' were kneaded with three rolls according to the compounding ratio shown in Table 3 below.
A resist ink of 50 to 300 ps/25° C. was obtained. In addition, in Example 16, TMPTA obtained in Example 1 was
In Comparative Examples 9 to 11, TMPTA obtained in Comparative Example 1 was
Moreover, in Comparative Example 9, HDDA obtained in Comparative Example 5 is further used. Then, this ink was applied to a glass-epoxy printed board on which a circuit pattern was formed to a thickness of about 20 μm by screen printing. After that, a negative mask was applied and a high pressure mercury lamp of 80 W/cm was applied to cure the coating film until the surface hardness reached 3H or higher (JIS D-0202). We conducted a test. These results are shown in the same table.

"Comparative Example 12" A resist ink of 500 ps/25° C. was obtained by kneading with three rolls according to the compounding ratio shown in Table 3 below. This ink was applied to a glass-epoxy printed board on which a circuit pattern was formed in the same manner as in Example 16 above. Note that the film thickness at this time was approximately 30 μm. Thereafter, various performance tests were conducted in the same manner as in Example 16.

[0042] These results are shown in the same table.

[0043]

[Table 3]

[0044] The various performance tests shown in the table are as follows:
The test was conducted according to the following test method.

"Curing" 80W/cm high pressure mercury lamp,
It is installed at a position 10 cm above a belt conveyor that moves at a speed of 10 m/min, and ultraviolet rays are irradiated toward this belt conveyor. A substrate printed with each resist ink is placed on the belt conveyor, passed through an ultraviolet irradiation position, and the surface hardness of the coating film is measured. At this time, if the surface hardness of the coating film is 3H or less, the substrate is passed through the ultraviolet irradiation position many times until the surface hardness becomes 3H or more. The test results were expressed as the minimum number of passes until the surface hardness reached 3H or higher.

"Solder resistance" After the coating film is cured, the substrate is
The condition of the coating film when immersed in molten solder at ℃ for 30 seconds was judged as follows (JIS C-6481
).

○: No abnormality in appearance of coating film
x: "Pressure Cooker Test (PCT)" in which blistering, melting, and peeling were observed. After the coating film had been cured, the substrate was treated in an autoclave at 121° C. and 98% HR for 24 hours. The adhesion of the coating film was judged. Note that adhesion is determined according to the adhesion test shown below.

[0048] Adhesion test (JIS-0202): 1m
In a cellophane adhesive tape peel test with a grid pattern of m intervals,
It is expressed as follows based on the ratio of the area of the coating film remaining after the cellophane adhesive tape is peeled off.

○: 100/100 △: 10-9
9/100 ×: 0 to 9/100 "Solvent Resistance" The adhesion of the coating film was judged when the substrate after the coating film had been cured was immersed in trichlorethylene at 25° C. for 1 hour. The adhesion is determined according to the adhesion test described above.

[0050] In Comparative Example 9, in order to make the compounding ratio of the reactive prepolymer (resin of Synthesis Example 1) and talc, which is an inorganic substance, and the viscosity of the resist ink similar to those in Example 16, TMPTA was used. This is an example using HDDA with low viscosity. In the above example, since HDDA, which is less reactive than TMPTA, is used as a reactive diluent, the curing speed of the resist ink is slow and the solder resistance is also poor.

Comparative Example 10 is an example in which the amount of talc, which is an inorganic substance, added was reduced in order to make the viscosity of the resist ink similar to that of Example 16. In the above case, since the amount of the inorganic substance is small, the shrinkage rate during curing becomes large, and it seems that sufficient adhesion is not obtained.

Comparative Example 11 is an example in which the amount of the reactive prepolymer (resin of Synthesis Example 1) was reduced in order to make the viscosity of the resist ink similar to that of Example 16. In the above method, since the reactive resin content is small, the curing speed of the resist ink is slow and the adhesion is poor.

In Comparative Example 12, since the composition was the same as in Example 16, the viscosity of the resist ink was higher than in the Example.

[0054]

According to the production method of the present invention, a (meth)acrylate having high dilutability with respect to inorganic substances can be obtained, so that it is possible to reduce the viscosity of a curable composition. In other words,
If the composition is the same as before, the viscosity of the curable composition can be lowered, and if the viscosity is the same as before, it is possible to increase the amount of inorganic substances or reactive prepolymers in the curable composition. This means that more reactive (meth)acrylates can be used.

[0055] Therefore, the curable composition obtained by the production method of the present invention does not have the same performance as the conventional one (the same composition as the conventional one shows the same performance), but has a low viscosity, so it can be used, for example, in paints. When used as such, it has very good workability.

Furthermore, the curable composition obtained by the production method of the present invention has low shrinkage, adhesion, heat resistance, and corrosion resistance, since the amount of inorganic material can be increased as long as the viscosity is the same as that of the conventional one. It is possible to improve physical properties such as, and reduce costs.

Claims (4)

[Claims] Claim 1: A method for producing a curable composition comprising an inorganic substance and (meth)acrylate as essential components, wherein the (meth)acrylate is (meth)acrylic acid and/or (meth)acrylic ester. and alcohol in the presence of a copper compound. 2. The method for producing a curable composition according to claim 1, wherein the (meth)acrylate is a polyfunctional (meth)acrylate. 3. The copper compound is metallic copper, copper oxide, sulfide,
3. The compound according to claim 1 or 2, characterized in that it is at least one member selected from the group consisting of hydroxides, ammonia complexes, sulfates, halides, carbonates, phosphates, and carboxylates. Method for producing curable composition. 4. A curable composition obtained by the production method according to claim 1.