JP3551050B2 - Method for producing thermosetting resin aqueous solution - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing a thermosetting resin aqueous solution, and more particularly to a method for producing a thermosetting resin aqueous solution that is useful as a water-proofing agent for a paper coating resin composition and as an ink deposition improver.
[0002]
[Prior art]
Thermosetting resins used for paper coating resins are conventionally deammonia-reacted with urea and polyalkylenepolyamine, then dehydrated and condensed with dibasic carboxylic acid, and further deammoniaized with urea to form polyurea polyamide. It is obtained by synthesizing and then reacting polyurea polyamide with formaldehyde in an aqueous solution (see Japanese Patent Publication No. 56-29929).
[0003]
[Problems to be solved by the invention]
However, the conventional method has a problem that the hue of the obtained thermosetting resin changes variously from yellow-red to reddish-brown and is not constant, which is not preferable as a paper coating resin.
The present inventors have developed a thermosetting resin aqueous solution for coated paper which is excellent in water resistance effect, generates a small amount of formaldehyde from coated paper, has excellent ink inking property during printing, and has a stable hue. As a result of intensive studies, the present invention has been achieved.
[0004]
[Means for Solving the Problems]
That is, the present invention provides a deammonification reaction between urea and a polyalkylene polyamine, followed by a dehydration condensation with a dibasic carboxylic acid, and a deammonia reaction with urea to synthesize a polyurea polyamide. In a method of obtaining a thermosetting resin aqueous solution by reacting with formaldehyde under acidity or once under alkaline conditions and then further reacting under acidic conditions, methylol urea is used in at least one of the two deammonia reactions. An object of the present invention is to provide a method for producing a thermosetting resin aqueous solution characterized by being present.
Hereinafter, the present invention will be described in detail.
[0005]
BEST MODE FOR CARRYING OUT THE INVENTION
Examples of the polyalkylene polyamine used in the present invention include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, iminobispropylamine, 3-azahexene-1,6-diamine, and 4,7-diazadecane-1,10-diamine. Examples of such amines include two primary amino groups and at least one secondary amino group in the molecule.
These polyalkylene polyamines are used singly or as a mixture of two or more.
[0006]
Examples of the dibasic carboxylic acid include, for example, aliphatic carboxylic acids such as succinic acid, glutaric acid, adipic acid, sebacic acid, maleic acid, and fumaric acid, and aromatic acids such as isophthalic acid and terephthalic acid. Examples thereof include carboxylic acids and mixtures of these carboxylic acids.
[0007]
Examples of the methylol urea used in the present invention include those synthesized by a conventional method in a molar ratio of urea to formalin in the range of 1: 1 to 1: 3.
As described above, methylol urea is used in either one of the two deammonification reactions or in both reactions, and the total amount thereof is preferably 0.1 to 1 based on 100 parts by weight of urea. Parts by weight, more preferably 0.2 to 0.6 parts by weight based on 100 parts by weight of urea.
[0008]
In the first deammonification reaction, the reaction molar ratio of urea and polyalkylene polyamine is preferably around 1: 2.
The reaction temperature is preferably in the range of 100 to 200C, more preferably in the range of 120 to 170C.
This reaction is carried out while removing ammonia out of the reaction system, and the reaction time is usually in the range of 2 to 8 hours.
[0009]
The amount of the dibasic carboxylic acid used in the following dehydration condensation reaction with the dibasic carboxylic acid is preferably in the range of 0.8 to 1.2 mol per 1 mol of the polyalkylene polyamine.
The reaction temperature is preferably in the range of 120 to 250 ° C, more preferably 130 to 200 ° C. When the condensation is carried out while removing by-product water out of the reaction system, the reaction time is usually 2 to 10 hours. Range.
[0010]
The polyurea polyamide polyamine obtained by the condensation reaction is subjected to a deammonification reaction with urea in the presence or absence of methylol urea. The amount of urea used in this reaction is preferably 0.5 to 1.5 mol, more preferably 0.7 to 1.2 mol, based on 1 equivalent of the secondary amino group in the polyalkylene polyamine. Range.
The reaction temperature in the second deammonification reaction is preferably in the range of 100 to 180 ° C, more preferably 120 to 150 ° C. This deammonification reaction is carried out while removing by-product ammonia to the outside of the reaction system, and the reaction time is usually about 1 to 5 hours.
[0011]
In this way, a polyamide polyurea is obtained, and the methylol urea can be present in one or both of the above-mentioned two deammonification reactions, either in whole or in part.
[0012]
The polyamide polyurea is then reacted with formaldehyde in water. The reaction is carried out at a polyamide polyurea concentration of preferably 20 to 70% by weight, more preferably 30 to 60% by weight, and a pH of preferably 7 or less, more preferably 3.5 to 6.5. Done. The reaction temperature and reaction time are usually in the range of 40 to 80 ° C and 1 to 10 hours, respectively.
The pH is adjusted using, for example, an inorganic or organic acid such as hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, and acetic acid.
[0013]
In the reaction between the polyamide polyurea and formaldehyde, the reaction is once carried out under alkaline conditions, for example, at a pH of 8 to 12, and the pH is further reduced to preferably 7 or less, more preferably 3.5 to 6.5. May be.
In this case, it is preferable that the reaction is carried out at a temperature of 40 to 80 ° C. for 0.5 to 3 hours under alkaline conditions, and at a temperature of pH 7 or less at a temperature of 40 to 80 ° C. for 1 to 10 hours.
The amount of formaldehyde used in the reaction with the polyamide polyurea is preferably 0.2 to 1 mol, more preferably 0.3 to 0.7 mol, based on 1 mol of the total urea used for the synthesis of the polyamide polyurea. Range.
After completion of the reaction, if necessary, the pH is adjusted to 6 to 9 using an alkali such as caustic soda and caustic potash to obtain the thermosetting resin aqueous solution of the present invention.
[0014]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, it is excellent in water resistance, ink adhesion | attachment property, etc., and the amount of formalin generation is small, and the resin aqueous solution which stabilized the hue was obtained, and this aqueous solution can be used advantageously as a coating composition for paper etc.
[0015]
【Example】
Hereinafter, the present invention will be described more specifically with reference to examples. In the examples, parts and% are parts by weight and% by weight, respectively.
[0016]
Example 1
While stirring a mixture of 292 parts of triethylenetetramine and 60 parts of urea, the mixture was reacted at 145 to 150 ° C. for 4 hours while removing by-product ammonia from the reaction system.
Next, 146 parts of adipic acid were added, and a condensation reaction was performed at 150 to 155 ° C for 5 hours. After cooling to 120 ° C, 240 parts of urea and 0.72 parts of methylol urea were added, and a deammonification reaction was performed at 125 to 130 ° C for 2 hours. Thereafter, 1350 parts of water was gradually added to obtain an aqueous solution of polyurea polyamide.
Next, 202.5 parts of 37% formalin was added, the pH was adjusted to 5 using concentrated hydrochloric acid, and the mixture was stirred at 65 ° C for 4 hours. After cooling to 30 ° C., the pH was adjusted to 8 with a 30% aqueous sodium hydroxide solution to obtain a thermosetting resin aqueous solution having a solid content of 30%.
The obtained resin aqueous solution was equivalent in performance to a thermosetting resin aqueous solution obtained without adding methylol urea, and had a yellow hue of APHA200.
[0017]
Example 2
A mixture of 292 parts of triethylenetetramine, 60 parts of urea, and 0.36 part of methylol urea was reacted at 145 to 150 ° C. for 4 hours while removing by-product ammonia to the outside of the reaction system.
Next, 146 parts of adipic acid were added, and a condensation reaction was performed at 150 to 155 ° C for 5 hours. After cooling to 120 ° C, 240 parts of urea and 1.44 parts of methylol urea were added, and a deammonification reaction was performed at 125 to 130 ° C for 2 hours. Thereafter, 1350 parts of water was gradually added to obtain an aqueous solution of polyurea polyamide.
Next, 202.5 parts of 37% formalin was added, the pH was adjusted to 5 using concentrated hydrochloric acid, and the mixture was stirred at 65 ° C for 4 hours. After cooling to 30 ° C., the pH was adjusted to 8 with a 30% aqueous sodium hydroxide solution to obtain a thermosetting resin aqueous solution having a solid content of 30%.
The obtained resin aqueous solution was equivalent in performance to a thermosetting resin aqueous solution obtained without adding methylol urea, and had a yellow hue of APHA250.
[0018]
Example 3
A mixture of 292 parts of triethylenetetramine, 60 parts of urea, and 0.18 part of methylol urea was subjected to a deammonification reaction at 150 to 153 ° C for 3 hours.
Next, 146 parts of adipic acid were added, and a condensation reaction was performed at 155 to 160 ° C for 5 hours. After cooling to 130 ° C, 240 parts of urea and 0.72 parts of methylol urea were added, and a deammonification reaction was performed at 130 to 135 ° C for 2 hours. Thereafter, 550 parts of water was gradually added to obtain an aqueous solution of polyurea polyamide.
Next, 121.5 parts of 37% formalin was added, the pH was adjusted to 4 using 20N-sulfuric acid, and the mixture was stirred at 70 ° C for 4 hours. After cooling to 30 ° C., the pH was adjusted to 6.5 with a 30% aqueous sodium hydroxide solution to obtain a thermosetting resin aqueous solution having a solid content of 50%.
The obtained resin aqueous solution was equivalent in performance to a thermosetting resin aqueous solution obtained without adding methylol urea, and had a yellow hue of APHA400.
[0019]
Example 4
A mixture of 292 parts of triethylenetetramine, 60 parts of urea, and 0.36 part of methylol urea was subjected to a deammonification reaction at 150 to 153 ° C for 3 hours.
Next, 146 parts of adipic acid were added, and a condensation reaction was performed at 155 to 160 ° C for 5 hours. After cooling to 130 ° C., 240 parts of urea and 1.44 parts of methylol urea were added, and a deammonification reaction was carried out at 130 to 135 ° C. for 2 hours. Thereafter, 550 parts of water was gradually added to obtain an aqueous solution of polyurea polyamide.
Next, 121.5 parts of 37% formalin was added, the pH was adjusted to 4 using 20N-sulfuric acid, and the mixture was stirred at 70 ° C for 4 hours. After cooling to 30 ° C., the pH was adjusted to 6.5 with a 30% aqueous sodium hydroxide solution to obtain a thermosetting resin aqueous solution having a solid content of 50%.
The obtained resin aqueous solution was equivalent in performance to a thermosetting resin aqueous solution obtained without adding methylol urea, and had a yellow hue of APHA500.
[0020]
Comparative Example 1
A mixture of 292 parts of triethylenetetramine and 60 parts of urea was subjected to a deammonification reaction at 145 to 150 ° C for 4 hours.
Next, 146 parts of adipic acid were added, and a condensation reaction was performed at 150 to 155 ° C for 5 hours. After cooling to 120 ° C, 240 parts of urea was added, and a deammonification reaction was performed at 125 to 130 ° C for 2 hours. Thereafter, 1350 parts of water was gradually added to obtain an aqueous solution of polyurea polyamide.
Next, 202.5 parts of 37% formalin was added, the pH was adjusted to 5 using concentrated hydrochloric acid, and the mixture was stirred at 65 ° C for 4 hours. After cooling to 30 ° C., the pH was adjusted to 8 with a 30% aqueous sodium hydroxide solution to obtain a thermosetting resin aqueous solution having a solid content of 30%.
The hue of the obtained resin aqueous solution was yellow-red.

Claims (1)

A urea and a polyalkylene polyamine are subjected to a deammonification reaction, followed by a dehydration condensation with a dibasic carboxylic acid, and further a deammonia reaction with a urea to synthesize a polyurea polyamide. Or a method for obtaining a thermosetting resin aqueous solution by further reacting under acidic conditions once reacted under alkaline conditions, wherein methylol urea is present in at least one of the two deammonification reactions. Of producing an aqueous thermosetting resin solution.