JPS5818385B2 - Epoxy resin molding material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an epoxy resin emulsion composition, and more specifically, after mixing a liquid epoxy resin and an amine derivative that is poorly soluble in water and has two or more active hydrogens, an emulsifier and, if necessary, After adding a small amount of water or adding and mixing the epoxy resin and the amine derivative in the presence of an emulsifier and optionally a small amount of water,
This is a method for producing an epoxy resin emulsion composition, which is characterized by adding water and, if necessary, a protective colloid to emulsify it.

It is well known that epoxy resin emulsion compositions are widely used in paints, adhesives, and binders for processing paper, cloth, etc. Among these, the field in which they are used in particularly large quantities is paints, and Conventionally, bisphenol A type epoxy resins have been widely used.

One of the properties particularly required for this paint is that it dries quickly to the touch, and for this purpose it is necessary to use a high molecular weight epoxy resin.

By the way, it is known to obtain a high molecular weight epoxy resin by reacting an epoxy resin with an amine compound in advance, but all of these methods are carried out in an epoxy resin solution in an organic solvent. It is not yet known to increase the molecular weight of the epoxy resin as an epoxy resin emulsion composition.

Of course, an epoxy resin organic solvent solution containing such a high molecular weight epoxy resin as an active ingredient is effective in terms of improving dryness to the touch due to the high molecular weight of the epoxy resin. Because of the necessity to use organic solvents, there are problems with the human body during work (particularly poisoning due to solvents), work management problems associated with handling flammable solvents, and large amounts of the solvent volatilize. There are various problems such as pollution caused by

For this reason, a water-based engineered resin composition that does not use such organic solvents is strongly desired.

For this reason, it is already known to use an epoxy resin emulsion composition mixed with a curing agent emulsion as a water-based paint that does not use organic solvents. Types of epoxy resin as the resin component are mainly used.

However, the epoxy resin used in such emulsions has a small molecular weight, so it takes a long time to dry to the touch, and therefore it takes a long time to develop the desired strength, making it difficult to recoat in a short period of time. It has disadvantages such as difficulty in

In order to improve this drawback, it is effective to use an epoxy resin with a large molecular weight as described above, but in general, high molecular weight epoxy resins have the drawback that they are difficult to emulsify because they are solid. However, it was hardly known that an emulsion composition made of such a high molecular weight epoxy resin could be produced and used for purposes such as coatings.

For these reasons, there has been a strong demand for an epoxy resin emulsion composition containing a high-molecular-weight epoxy resin as an active ingredient, which does not have the disadvantages associated with the use of organic solvents and can also improve dryness to the touch.

Therefore, the present inventors conducted extensive research on epoxy resin emulsion compositions that do not involve the use of organic solvents, in order to increase the molecular weight of the epoxy resins and produce epoxy resin compositions with improved dryness to the touch. The inventors have discovered that an epoxy resin emulsion composition containing a high molecular weight epoxy resin as an active ingredient can be obtained only under specific conditions, and have completed the present invention.

That is, the present invention uses a liquid epoxy resin and an amine derivative that is poorly soluble in water and has two or more active hydrogen atoms, so that the amount of functional groups in the amine derivative is 0.1 to 1.0 equivalent per equivalent of epoxy group in the epoxy resin. Mix to the extent that
After adding an emulsifier and a small amount of water as necessary, or adding and mixing the epoxy resin and the amine derivative of the above range in the presence of an emulsifier and a small amount of water as necessary, water and a small amount of water as necessary. This is a method for producing an epoxy resin emulsion composition whose active ingredient is a high-molecular-weight epoxy resin that is emulsified by adding a protective colloid according to the conditions.

By using the epoxy resin emulsion composition thus obtained together with a curing agent for epoxy resin emulsions, various problems caused by the use of organic solvents can be avoided (the extremely remarkable effect of improving dryness to the touch can be achieved). play.

Furthermore, the strength of paper can also be improved by impregnating paper with the epoxy resin emulsion composition obtained in this way and curing it under heat.

This is because the resin component of the composition is a precondensate of an epoxy resin and an amine derivative having two or more active hydrogen atoms, so the tertiary amine structure in the precondensate develops a catalytic effect when heated. This is due to further polymerization of the precondensate.

As described above, in the present invention, a liquid epoxy resin and an amine derivative having two or more active hydrogen atoms are mixed, and then a pore-forming agent is added, or the epoxy resin and the amine derivative are mixed in the presence of an emulsifier, and both are mixed in advance. After pre-condensing to increase the molecular weight, water is added to this to inhibit the condensation reaction,
To make a stable emulsion, simply mix the epoxy resin and the hardener emulsion for epoxy resin (
In other words, although they appear to be similar at first glance to methods used in normal use, their contents are completely different, and this is clearer than the comparison of the two described below.

The liquid epoxy resin used in the present invention is a commercially available ordinary liquid epoxy resin, for example, an epoxy resin obtained from an acetone condensate of bisphenol A or resorcinol and epichlorohydrin, an epoxidized polyolefin resin, a polyorthocresol formaldehyde poly(2・3-epoxyglobil) ether and polyph; Epoxidized novolak resins such as enol formaldehyde poly(2,3-epoxyglobil) ether, polyglycidyl esters of polycarboxylic acids such as hexahydrone tar acid and tetrahydrophthalic acid. Examples include liquid epoxy resins such as alicyclic epoxy resins such as, but in the present invention, bisphenol A type liquid epoxy resins are particularly preferred.

Examples of amine derivatives that are poorly water-soluble and have two or more active hydrogen atoms include modified aliphatic amines, high molecular weight aliphatic amines, diaminodiphenylmethane, methanelenediamine, liquid aromatic amines, fatty acid-modified polyamides, and amines. Generally, curing agents for epoxy resins such as epoxy resin adducts are exemplified, but aromatic amines that are sparingly soluble in water and curing at room temperature, such as Sumicure ML (
Preferred are liquid modified aromatic amines (manufactured by Sumitomo Chemical Co., Ltd.), SUMICURE MT (room-temperature curing aromatic polyamines, manufactured by Sumitomo Chemical Co., Ltd.), and the like.

The mixing ratio of the liquid epoxy resin and the amine derivative is usually 0.1 to 1.0 equivalent of the functional group in the amine derivative per 1 equivalent of the epoxy group in the epoxy resin.
Considering storage stability, it is preferable to use an amount of the amine derivative that is less than the chemical equivalent.

Of course, even if amounts corresponding to chemical equivalents are used, if the method of the present invention is followed, both components will remain as precondensates without completing the reaction in the emulsion, and water evaporation during use will occur. Since the curing reaction is completed by heating or the like, in this case it can be effectively used as a so-called one-component epoxy resin emulsion composition with improved dryness to the touch.

If the proportion of the amine derivative is less than the one specified in the present invention, the epoxy resin and the amine derivative will not be sufficiently precondensed, and therefore the epoxy resin will not have a high molecular weight, making it difficult to use it for applications such as paints. Even if used, sufficient effects cannot be expected.

On the other hand, when the amine derivative is used in such a range that the functional group in the amine derivative is 0.1 equivalent or more and less than 1 equivalent per equivalent of epoxy group in the liquid epoxy resin,
Since the high-molecular-weight epoxy resin still has unreacted epoxy groups, this epoxy resin emulsion composition is used as a room-temperature curing agent and an amine used as a curing agent for epoxy resins in the same way as in the conventional method. By adding the compound or its emulsion, it can be effectively used for paints with improved touch dryness and other uses.

The curing agent added at this time is added so that the functional groups in the curing agent are chemically equivalent to or more than the unreacted residual epoxy groups in the epoxy resin emulsion composition.

Of course, if it is necessary not only to cure at room temperature but also to heat cure as necessary, a heat curing curing agent may be added to the emulsion composition having such unreacted epoxy groups. Effectively used as a material with excellent dryness to the touch.

Examples of curing agents for this purpose include latent curing agents such as imidazoles, metal salts of organic carboxylic acids, and tertiary amines.

The emulsifier used in the present invention is not particularly limited,
For example, Emulgen A, which has already been widely known
-90 (manufactured by Kao Atlas Co., Ltd.) and Ninotsukor FK-5 (
(manufactured by Nikko Chemical Co., Ltd.), etc., and the amount used is usually 15 parts by weight or less per 100 parts by weight of the epoxy resin.

Also, the amount of water used as necessary with the emulsifier is sufficient to uniformly mix the liquid epoxy resin, amine derivative, and emulsifier, and the amount may vary depending on the mixing ratio of each, the target compound, etc. The amount is usually 0 to 30 parts by weight, more preferably 0 to 20 parts by weight, based on 100 parts by weight of all mixed components.

If this amount of water becomes too large, will it be possible to get it? The storage stability of the epoxy resin emulsion composition obtained is poor (and a sufficient effect in terms of dryness to the touch cannot be obtained).

In the method of the present invention, water is then added to form a complete emulsion composition, which is the most distinctive feature of the invention.

In other words, the reason for this is not clear (but if a liquid epoxy resin and an amine compound were added together with a large amount of water and an emulsifier to emulsify it, or if emulsions of a liquid epoxy resin and an amine compound were mixed together), The effect obtained with the present invention as described above cannot be obtained, and only when mixed with an emulsifier and, if necessary, a small amount of water as in the present invention, and then a large amount of water is added to form an emulsion. Excellent effects can be obtained.

Furthermore, after mixing the epoxy resin and the amine derivative or in the presence of an emulsifier, a better effect can be obtained by allowing the mixture to stand for some time, usually 5 to 60 minutes, before adding water. be able to.

) The amount of water used at this time may be such that it has a concentration necessary for use as a normal emulsion composition, and is generally 50 to 150 parts by weight based on 100 parts by weight of all mixed components.

Also, after adding water to room temperature or after slightly heating (usually 30
~60°C) and aging is also effective.

The protective colloid in the present invention is not necessarily an essential component of the present invention (but may be added as necessary, for example, when a high degree of storage stability is required).

Examples of protective colloids for this purpose include methyl cellulose and polyvinyl alcohol, but in particular, styrene-butadiene latex, polyvinyl propionate emulsion, polyvinyl acetate emulsion, ethylene vinyl acetate emulsion, polyacrylic emulsion, and phthalinic colloid. Although other synthetic resin emulsions such as nitrile emulsions, polystyrene emulsions, and styrene-acrylic emulsions exhibit remarkable effects, the amount of these protective colloids added is usually equal to or less than the amount of the epoxy resin.

When using the epoxy resin emulsion composition obtained according to the present invention, if a curing accelerator is required, it may be optionally added to either the main ingredient (epoxy resin emulsion composition) or the curing agent side, or both sides. Can be done.

In this way, the present invention involves mixing a liquid epoxy resin and an amine derivative that is poorly water-soluble and having two or more active hydrogen atoms in a specific ratio, adding an emulsifier and, if necessary, a small amount of water, and then further mixing; An emulsion composition containing an epoxy resin as an active ingredient whose molecular weight has been increased by performing two-stage emulsification, in which an epoxy resin and an amine derivative are added and mixed in the presence of a small amount of water as necessary, and then water is added and emulsified. This process is completely different from simply mixing emulsions of an epoxy resin and an amine derivative, or emulsifying an epoxy resin and an amine compound together with an emulsifier in a large amount of water in one step. be.

The epoxy resin emulsion composition produced by this method exhibits excellent dryness to the touch when used in paints, etc., compared to those obtained by the other methods mentioned above.

The present invention will be specifically explained below using examples.

In the example, "center part" indicates parts by weight. Example 1 100 parts of Sumiepoxy ELA-128 (bisphenol A type liquid epoxy resin, manufactured by Sumitomo Chemical Co., Ltd.) and Sumicure MT-1 (aromatic polyamine-based epoxy curing agent,
(Manufactured by Sumitomo Chemical Co., Ltd.) were mixed well, and 10 parts were mixed at room temperature.
After standing for a minute, 5 parts of an emulsifier (Emulgen A-90, manufactured by Kao Atlas Co., Ltd.) and 20 parts of water were added with thorough stirring.

To this mixture, 30 parts of Sumikaflex 400 (ethylene-vinyl acetate emulsion, manufactured by Sumitomo Chemical Co., Ltd.) was added as a protective colloid.

After mixing well, 115 parts of water was gradually added with stirring.

The obtained epoxy resin emulsion composition was left at room temperature for one month, but the storage stability was good.

3 parts of aminoethylpiperazine (manufactured by Steel Chemical Co., Ltd., curing agent for epoxy resins) was added to 100 parts of this epoxy resin emulsion composition, and then applied to a glass plate.

The dryness of this coating film to the touch was 90 minutes at room temperature.

On the other hand, for comparison, 6.7 parts of aminoethylpiperazine was added to 100 parts of an emulsion composition prepared in exactly the same manner as above, except that Sumicure MT-1 was not used, and this was applied to a glass plate. Dryness to the touch was 150 minutes.

Further, the epoxy resin emulsion composition obtained earlier was impregnated into two sheets of paper, which were then stacked on top of each other, and heated and cured in a dryer at 120° C. for 1 hour.

As a result, I was able to glue the two pieces of paper together.

Example 2 100 parts of Sumiepoxy ELA-128 and 35 parts of Persamide 140 (manufactured by Daiichi General Co., Ltd., a hardening agent for polyamide-based epoxy resins) were mixed, and after being left at room temperature for 30 minutes, an emulsifier (Emulgen A-90, Kao Atlas) was mixed. and 20 parts of water were added with thorough stirring.

To this mixture was added 30 parts of Sumikaflex 400 as a protective colloid.

After mixing well, 115 parts of water was gradually added with stirring.

The epoxy resin emulsion composition thus obtained formed a good coating film after water evaporation even without the addition of a curing agent.

Example 3 100 parts of Sumiepoxy ELA-12s and 50 parts of Persamide 140 were added in the presence of 20 parts of Sumikaflex 400 and 7 parts of an emulsifier (Emulgen A-90) and mixed well, and then 130 parts of water was added with stirring. Gradually add the epoxy resin emulsion composition to the barrel.

This emulsion was aged for 1 hour while stirring at 50° C. This emulsion was applied to a glass plate.

This dryness to the touch was reached in 2 hours.

Moreover, this emulsion had stable storage properties over a long period of time.

Example 4 After thoroughly mixing 100 parts of Sumiepoxy ELA-128 and 20 parts of Persamide 125, they were left to stand at room temperature for 10 minutes, and then 5 parts of an emulsifier (Emulgen A-90, manufactured by Kao Atlas Co., Ltd.) was added and mixed well. After mixing, add 12 liters of water while stirring.
0 parts were added gradually.

After adding water, the mixture was aged at 50° C. for 24 hours with stirring.

After adding 4.4 parts of aminoethylpiperazine to 100 parts of the obtained epoxy resin emulsion composition, it was applied to a glass plate.

The stickability of this coating film was 80 minutes at room temperature.

On the other hand, for comparison, emulsion composition 10 was prepared in the same manner as above except that persamide 125 was not used.
When a mixture of 0 parts and 25 parts of aminoethylpiperazine was applied to a glass plate, the dryness to the touch was 150.
It was a minute.

Comparative Example 1 100 parts of Sumiepoxy ELA-128, 7 parts of an emulsifier (Emulgen A-90) and 20 parts of Sumikaflex 400 were mixed with good mixing wave stirring and 80 parts of water was gradually added to obtain an epoxy resin emulsion.

Next, 50 parts of persamide, 140.2 parts of acetic acid, and 1 part of an emulsifier (Emulgen A-90) were added, and while stirring well, 50 parts of water was gradually added to obtain an emulsion of the hardening agent.

The epoxy resin emulsion and the hardening agent emulsion were mixed and then applied to a glass plate.

This coating took 4 hours to dry to the touch at room temperature.

This mixture was placed in a polycup to check its pot life, but after being left at room temperature for a day and night, the mixture gelled and could no longer be used.

Claims (1)

[Claims] 1 A liquid epoxy resin and an amine derivative that is poorly soluble in water and has two or more active hydrogens are used in such a manner that the functional group of the amine derivative is 0.1 per equivalent of the epoxy group in the epoxy resin.
After increasing the molecular weight of the epoxy resin by condensation to a range of ~1.0 equivalent, add an emulsifier and optionally a small amount of water, or add an emulsifier and optionally a small amount of water in the above range. A method for producing an epoxy resin emulsion composition, which comprises condensing the epoxy resin and the amine derivative to increase the molecular weight of the epoxy resin, and then emulsifying the epoxy resin by adding water and, if necessary, a protective colloid.