JP3395248B2 - Method for producing modified amino resin - Google Patents

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 modified amino resin having a controlled molecular weight. The resin composition containing the amino resin modified product according to the production method of the present invention can be used for a wide range of applications such as paints, inks, adhesives and sealing agents.

[0002]

2. Description of the Related Art Conventionally, amino resins such as melamine resins and guanamine resins have been suitably used as thermosetting components in resin compositions such as paints. Such an amino resin is usually dissolved in an organic solvent together with an alkyd resin, an acrylic resin, an epoxy resin, a polyester resin, etc.
It is used as a solvent type paint. As the amino resin used as the thermosetting component, a melamine-based resin, a benzoguanamine-based resin, an acetoguanamine-based resin, a spiroguanamine-based resin, or the like can be used depending on the physical properties of the cured product to be obtained, and the amino resin can be used by appropriately modifying them. For example,
Modification with an acid compound is an effective means for improving the compatibility with other resins, the curing characteristics, and the adhesion to the substrate.

On the other hand, in recent years, from the viewpoints of environmental protection and harmfulness to the human body, it has been required to reduce the amount of organic solvent discharged during the painting process, and water-based paints and the like are being advanced.
Generally, low molecular weight amino resins are used for water-based paints and the like, but in order to impart sufficient water solubility, it is often practiced to introduce an acid compound into the amino resin by a graft reaction or the like. . However, during the modification reaction, the amino resin is condensed to have a high molecular weight, which often causes problems such as high viscosity and water insolubility, and it has been difficult to obtain an amino resin having a desired molecular weight.

[0004]

Therefore, as a result of diligent studies to control the increase in the molecular weight of the amino resin during the modification reaction of the acid compound with the acid compound, the present inventor has completely or partially neutralized it with a basic compound in advance. The inventors have found that an amino resin modified product having a controlled molecular weight can be synthesized by reacting an organic acid compound obtained by the reaction with an amino resin, and have reached the present invention.

[0005]

The present invention provides a method for producing an amino resin modified product, which comprises reacting an organic acid compound obtained by preliminarily neutralizing all or part of it with a basic compound with an amino resin. When the amino resin is modified with the organic acid compound, the condensation reaction of the amino resin is suppressed by preliminarily neutralizing all or part of the organic acid compound with the basic compound, and the molecular weight of the amino resin is controlled. A modified product is obtained.

Amino resins are generally urea, melamine,
It is obtained by methylation by reacting an amino compound such as benzoguanamine and spiroguanamine with formaldehyde, and then etherification by dehydration condensation with alcohols.

The amino resin is modified by any of the following methods 1) and 2). 1) In the presence of an organic peroxide, an ethylenically unsaturated acid and / or an ethylenically unsaturated acid anhydride, which is wholly or partially neutralized with a basic compound, is reacted with an amino resin. 2) Ethylenic unsaturation containing ethylenically unsaturated acid and / or ethylenically unsaturated acid anhydride obtained by preliminarily neutralizing all or part of the amino resin with a basic compound in the presence of peroxide. Polymerize the monomers.

In the method 1), the usual graft reaction is carried out on the amino resin in the presence of the organic peroxide. For example, the previously neutralized ethylenically unsaturated acid and / or ethylenically unsaturated acid anhydride is 1 to 30% by weight, preferably 5 to
Used at 15% by weight, in the presence of 1 to 50% by weight of organic resin with respect to the amino resin, and at 70 to 120 ° C under an inert gas flow.
It is allowed to react with the amino resin for 2 to 6 hours.

Typical ethylenically unsaturated acids include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, glutaconic acid, tetrahydrophthalic acid,
Examples thereof include 3-sulfopropyl acrylate and 3-sulfopropylomethacrylate, and typical examples of ethylenically unsaturated acid anhydrides include maleic anhydride, itaconic anhydride, glutaconic anhydride, and tetrahydrophthalic anhydride. Etc.

Examples of the organic peroxides include benzoyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, diisopropyl peroxycarbonate, dit-butyl peroxide and t-butyl peroxybenzoate.

In the method 2), the ethylenically unsaturated acid and / or the ethylenically unsaturated acid anhydride obtained by pre-neutralizing are alkyl (meth) acrylate,
Hydroxyalkyl (meth) acrylate, styrene,
With other ethylenically unsaturated monomers such as vinyltoluene, (meth) acrylonitrile, vinyl acetate,
It is radically polymerized in the presence of a peroxide in an amino resin. For example, the polymerization of the ethylenically unsaturated monomer in the amino resin is carried out in the presence of peroxide under an inert gas stream at 60 to 120 ° C. for 2 to 6 hours. On this occasion,
The ethylenically unsaturated monomer is 5 to 12 relative to the amino resin.
It is used in an amount of 0% by weight, preferably 15 to 100% by weight, and the amount of the ethylenically unsaturated acid and the ethylenically unsaturated acid anhydride in the ethylenically unsaturated monomer is 5 to 95% by weight. As the ethylenically unsaturated acid and the ethylenically unsaturated acid anhydride, those used in the above method 1) can be similarly mentioned.

In the above methods 1) to 2), prior to the reaction with the amino resin, all or part of the ethylenically unsaturated acid, ethylenically unsaturated acid anhydride or organic acid compound is preliminarily treated with a basic compound. Let it harmonize. The basic compound is used in an amount of 0.01 to 1 mol%, preferably 0.1 to 1 mol% based on the ethylenically unsaturated acid and the like. At this time, as the degree of neutralization is increased, the suppression of the condensation reaction of the amino resin becomes stronger, and an amino resin-modified product having a lower molecular weight can be obtained.

Examples of the basic compound include ammonia, monoethanolamine, ethylamine, dimethylamine, diethylamine, triethylamine, propylamine, dipropylamine, isopropylamine, diisopropylamine, triethanolamine, butylamine, dibutylamine, ethylhexylamine. , Ethylenediamine, propylenediamine, methylethanolamine, dimethylethanolamine, diethylethanolamine, morpholine, potassium hydroxide, sodium hydroxide and the like, but dimethylethanolamine is particularly preferable.

The amino resin modified product obtained by the production method of the present invention can be used alone as an oily or water-based paint, ink,
It can be used as a binder such as an adhesive or a sealing agent, but can be used as a resin composition by including other resin components if necessary. Examples of other resins include acrylic resins, epoxy resins, polyester resins, urethane resins, and the like.
It is used in an amount of 5 to 95% by weight based on the total solid content. In addition, the resin composition may include, if necessary, dyes, pigments, various additives for improving the physical properties of the cured product, such as fillers, leveling agents, curing agents, flame retardants, and thickeners. , A water-soluble organic solvent, a lubricity-imparting agent, etc. can be contained.

[0015]

[Production Example 1]

A separable four-necked flask was equipped with a temperature control regulator, a cooling tube, and a stirrer.
40 parts were charged, the temperature was raised to about 90 ° C and the inside of the reaction vessel was replaced with nitrogen, and then 280 parts ethyl acrylate and styrene were added from a dropping pipe.
168 parts, 56 parts of acrylic acid, 56 parts of hydroxyethyl methacrylate, and 56 parts of organic peroxide (“Perbutyl O” manufactured by NOF CORPORATION) were added dropwise over 3 hours. One hour after the completion of dropping, 5.6 parts of "perbutyl O" was added, and the reaction was continued for another hour. A resin solution having a solid content of 69.6% was obtained.

Example 1 A reaction apparatus similar to that of Production Example 1 was charged with 571 parts of partially butyl etherified benzoguanamine resin (“Cymel 1128” manufactured by Mitsui Cyanamid Co., Ltd., solid content 70%), 40 parts of itaconic acid, 33 parts of dimethylaminoethanol. Then, 40 parts of the organic peroxide "Perbutyl O" was dropped from the dropping tube over 1 hour after the temperature was raised to about 90 ° C. and the inside of the reaction vessel was replaced with nitrogen. After the dropwise addition was completed, the reaction was continued for another hour to obtain an amino resin-modified product having a solid content of 58.6%. To the obtained amino resin modified product 51.2 parts,
28.7 parts of the resin solution obtained in Production Example 1, 4.0 parts of dimethylaminoethanol and 16.1 parts of water were added with sufficient stirring.

Example 2 A reactor similar to that of Production Example 1 was charged with 571 parts of partially butyletherified benzoguanamine resin “Cymel 1128”, 40 parts of itaconic acid, and 5.5 parts of dimethylaminoethanol, and
After the temperature was raised to 90 ° C. and the inside of the reaction vessel was replaced with nitrogen, 40 parts of an organic peroxide “Perbutyl O” was dropped from a dropping tube over 1 hour. After the dropping was completed, the reaction was continued for another hour, and the solid content was 6
A 1.3% amino resin modified product was obtained. 48.9 parts of the obtained modified amino resin, 28.7 parts of the resin solution obtained in Production Example 1,
Dimethylaminoethanol (5.8 parts) and water (16.6 parts) were added with sufficient stirring.

Example 3 A methyl etherified benzoguanamine resin (“Melan 553” manufactured by Hitachi Chemical Co., Ltd., solid content) was added to the same reactor as in Production Example 1.
(85%) 471 parts were charged, the temperature was raised to about 90 ° C and the inside of the reaction vessel was replaced with nitrogen, and then 10 parts of ethyl acrylate, 10 parts of styrene, 5 parts of hydroxyethyl methacrylate, 15 parts of acrylic acid, dimethylaminoethanol were added from a dropping pipe. 15 parts and 8 parts of organic peroxide "Perbutyl O" were added dropwise over 1 hour. After the dropping was completed, the reaction was continued for another hour to obtain an amino resin-modified product having a solid content of 84.6%. Obtained modified amino resin 35.5
To the parts, 43.1 parts of the resin solution obtained in Production Example 1 and 21.4 parts of butyl cellosolve were added with sufficient stirring.

Comparative Example 1 A reactor similar to that of Production Example 1 was charged with 571 parts of partially butyl etherified benzoguanamine resin “Cymel 1128” and 40 parts of itaconic acid, and the temperature was raised to about 90 ° C. and the inside of the reaction vessel was replaced with nitrogen. After that, 40 parts of the organic peroxide "Perbutyl O" was dropped from the dropping tube over 1 hour. After the dropping was completed, the reaction was continued for another hour to obtain a modified amino resin having a solid content of 65.1%. To 46.1 parts of the obtained amino resin modified product, 28.7 parts of the resin solution obtained in Production Example 1, 6.2 parts of dimethylaminoethanol and water were added.
19.0 parts were added with thorough stirring.

[Comparative Example 2] 471 parts of methyl etherified benzoguanamine resin "Melan 553" was charged in the same reactor as in Production Example 1, and the reaction was carried out at about 90 ° C.
After the temperature was raised to 0 and the inside of the reaction vessel was replaced with nitrogen, 10 parts of ethyl acrylate, 10 parts of styrene, 5 parts of hydroxyethyl methacrylate, 15 parts of acrylic acid, and 8 parts of organic peroxide "Perbutyl O" were added through a dropping pipe for 1 hour. Was dropped. After the dropping was completed, the reaction was continued for another hour to obtain a modified amino resin having a solid content of 85.1%. To 35.3 parts of the obtained amino resin modified product, 43.1 parts of the resin solution obtained in Production Example 1 and 21.6 parts of butyl cellosolve were added with sufficient stirring. Example 1
Table 1 shows the weight average molecular weight (in terms of polystyrene) and the viscosity of the resin compositions of the amino resin modified products obtained in Comparative Example 1 and Comparative Examples 1 and 2.

[0021]

[Table 1]

[0022]

EFFECTS OF THE INVENTION Since the modified amino resin of the present invention is suppressed from having a high molecular weight during the modification reaction, the resin composition containing the modified amino resin has a low viscosity and excellent workability. Therefore, the amino resin modified product of the present invention can be used for a wide range of applications including paints, inks, adhesives, and sealing agents, and is extremely useful industrially.

Claims (2)

(57) [Claims] 1. In the presence of an organic peroxide, all or one of
Ethiate obtained by preliminarily neutralizing some parts with a basic compound
Renically unsaturated acids and / or ethylenically unsaturated acid anhydrides
And an amino resin are reacted with each other.
A method for producing a resin modified product. 2. Amino resin in the presence of a peroxide,
Pre-neutralize all or part of it with a basic compound.
The ethylenically unsaturated acid and / or ethylenically unsaturated
Polymerize ethylenically unsaturated monomer containing saturated acid anhydride
A method for producing a modified amino resin, which comprises: