JPH0356578B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is useful as a water resistance agent, ink adhesion improver, etc. for paper coating compositions, and has other advantages such as no coloring of coated paper, excellent blister resistance, and no generation of formaldehyde. The present invention relates to a method for producing a novel thermosetting resin aqueous solution having such properties. Traditionally, pigments and water-based binders have been the main ingredients,
It is known to produce coated paper with excellent printability by coating paper with a paper coating composition containing an adjuvant such as a waterproofing agent. In recent years, there has been significant progress in coated paper manufacturing technology. For example, in order to increase productivity, the solid concentration in the coating composition is increased and coating is performed at high speed with a blade coater. It is required that there is no increase in viscosity and that coating properties are good. Furthermore, as printing becomes more sophisticated and faster, and offset rotary printing becomes more widespread, improvements in the water resistance, ink transferability, and blister resistance of the coating layer are required. In order to improve these performances, many proposals have been made in the past, such as modification of the aqueous binder component and improvement of the auxiliary component. For example, water resistance can be improved by increasing the amount of aqueous binder relative to the pigment, but on the other hand, ink transferability during printing decreases, so a method is generally used in which a water resistance agent is added as an auxiliary component. A typical example of a water-resistant agent in this case is a water-based binder water-resistant agent, but while all of the previously used or proposed water-resistant agents have effective advantages, they also have serious drawbacks. However, it was not practically satisfactory. For example, melamine-formaldehyde initial condensates have insufficient ink transfer properties on coated paper and insufficient water resistance when the pH of the coating composition is high, and free formaldehyde is generated from coated paper. There are problems such as large amounts. In addition, the reaction product of polyamide urea and formaldehyde has an excellent effect on improving the ink transfer properties of coated paper and has good water resistance, but it is said that although the amount of free formaldehyde generated from coated paper is small, it is not completely absent. It has drawbacks. Furthermore, although dialdehydes such as glyoxal do not contain free formaldehyde, they have a poor effect on improving the ink transfer properties of Miyako paper. Therefore, there is a strong demand for the development of a water-resistant agent that can provide coated paper with excellent water resistance and ink transfer properties, and which does not generate formalin, which has a harmful and irritating odor. In view of these circumstances, the present inventors have developed a waterproofing agent that can provide coated paper with excellent waterproofing effects, no generation of harmful formaldehyde, and excellent ink transfer properties during printing. As a result of intensive research, we have arrived at the present invention. That is, the present invention provides (a) a polyalkylene polyamine, (b) 0.2 to 1.0 mole of urea per mole of amino groups in the polyalkylene polyamine (a), and (c) 1 mole of the polyalkylene polyamine (a). (d) A polyamide polyurea obtained by reacting 0.3 to 0.7 mol of dibasic carboxylic acid as a raw material, and (d) 0.01 to 2 mol of glyoxal and glutaraldehyde per 1 mol of urea in (b). This is a method for producing an aqueous thermosetting resin solution, which is characterized by reacting it with a selected dialdehyde. The polyalkylene polyamine used in the present invention is a polyalkylene polyamine having two primary amino groups and at least one secondary amino group in the molecule, such as diethylene triamine, triethylene tetramine, tetraethylene Pentamine, iminobispropylamine, 3
-Azahexane-1,6-diamine, 4,7-diazadecane-1,10-diamine, and the like.
These polyalkylene polyamines can be used not only alone but also as a mixture of two or more. Dibasic carboxylic acids used in the present invention include aliphatic carboxylic acids such as succinic acid, glutaric acid, adipic acid, sebacic acid, maleic acid, and fumaric acid; aromatic carboxylic acids such as isophthalic acid and terephthalic acid; Examples include mixtures of these. The dialdehyde used in the present invention is glyoxal or glutaraldehyde,
Each may be used alone or a mixture of the two may be used. Among these, glyoxal is particularly preferred. The polyamide polyurea referred to in the present invention is a polyamide polyurea (hereinafter referred to as polyamide polyurea [ A]
) or a polyamide polyurea (hereinafter referred to as polyamide polyurea [B]) obtained by dehydration condensation of a polyalkylene polyamine and a dibasic carboxylic acid, followed by a deammonia reaction with urea. In polyamide polyurea [A], the molar ratio of urea and polyalkylene polyamine is approximately 1:2
It is preferable to conduct it nearby. The reaction temperature is 100
-200℃, preferably 120-170℃,
While removing the generated ammonia from the system,
Allow time to react. Next, 1 mole of polyalkylene polyamine is subjected to dehydration condensation with 0.3 to 0.7 mole of dibasic carboxylic acid. The reaction is carried out at a reaction temperature of 120 to 250°C, preferably 140 to 200°C, for 2 to 10 hours while removing generated water from the system. The condensation reaction product thus obtained is further reacted with urea.
The amount of urea is 0.2 to 1.5 mol, preferably 0.5 to 1.1 mol, per mol of secondary amino groups in the raw material polyalkylene polyamine. Reaction temperature is 100-180
℃, preferably 120-150℃, and at this temperature 1
The reaction is carried out for ~5 hours while removing generated ammonia from the system. In this way, polyamide polyurea [A] is obtained. In the polyamide polyurea [B], the reaction between the polyalkylene polyamine and the dibasic carboxylic acid is carried out at a temperature of 120 to 250°C, preferably 140 to 200°C, while removing the water produced from the system. Time is done. The reaction is carried out at a molar ratio of 1.4 to 3.0 mol, preferably 1.8 to 2.5 mol, of polyalkylene polyamine per mol of dibasic carboxylic acid. The dehydration condensation reaction product thus obtained is then reacted with urea. The amount of urea used is 0.2 to 1.0 per mole of amino group in the raw material polyalkylene polyamine.
mol, preferably 0.4 to 0.8 mol. The reaction temperature is 100-180°C, preferably 120-150°C. The reaction is carried out at this temperature for 1 to 5 hours while removing the generated ammonia from the system. As a method of charging urea, it is possible to charge the required amount all at once and perform the reaction, or it is also possible to charge a part of the required amount and complete the deammonification reaction, and then charge the remaining urea and perform the deammonification reaction again. In this way, polyamide polyurea [B] is obtained. The polyamide polyurea obtained as described above is dissolved in water and reacted with dialdehyde. The reaction is carried out in an aqueous solution of polyamide polyurea with a concentration of 20 to 70% by weight, preferably 30 to 60%, using an acid such as hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, etc. to a pH of 8 or less, preferably 4 or less. After adjustment, the reaction is carried out at a temperature of 40 to 80°C for 1 to 10 hours. The appropriate amount of dialdehyde is 0.01 to 2 mol, preferably 0.05 to 1 mol, per 1 mol of total urea used to synthesize the polyamide polyurea. After the reaction is complete, if necessary, lower the pH of the reaction product to 6.
Adjust to ~9. In this way, the thermosetting resin produced by the method of the present invention can be used as a water resistant agent for paper coating compositions,
It is useful as an ink adhesion improver, and the coating composition for paper using it has no color shock (significant thickening of the composition, aggregation of pigments, etc.), and has excellent stability of the coating solution. The coated paper obtained by coating this on a paper base has excellent water resistance in the coating layer, no formaldehyde generation, excellent ink transfer properties, no coloration, and is suitable for offset wheel transfer printing. It has various excellent features such as being effective in improving blister resistance. The present invention will be explained below using Examples and Reference Examples. In the text, % represents weight % unless otherwise specified. Example 1 292 g (2 moles) of triethylenetetramine in a four-necked flask equipped with a thermometer, reflux condenser, and stirring bar.
and 60 g (1 mol) of urea were charged, and the reaction was carried out for 4 hours while removing ammonia generated from the system at 145-150°C. Next, 146 g (1 mol) of adipic acid was added and condensation was carried out at 150-155°C for 5 hours. The reaction was carried out.
After cooling to 120℃, add 240g (4 moles) of urea.
Deammonification reaction was carried out at 125-130°C for 2 hours.
Thereafter, 380 g of water was gradually added to obtain an aqueous solution of polyamide polyurea. Next, add 290g (2 mol) of 40% glyoxal aqueous solution and adjust the pH with 50% sulfuric acid.
After adjusting the temperature to 3.0, the mixture was stirred for 5 hours at 70°C.
The reaction solution was cooled to 25°C to obtain a thermosetting resin aqueous solution with a solid content of 50%. Example 2 Diethylenetriamine was added to the same apparatus as in Example 1.
Prepare 206g (2 moles) and 60g (1 mole) of urea,
Ammonia removal reaction was carried out at 140-145°C for 5 hours, then 146 g (1 mol) of adipic acid was added, and 160-145°C
Dehydration condensation was carried out at 170°C for 2 hours. After cooling to 120℃, add 120g (2 moles) of urea and heat to 130-140℃.
The deammoniation reaction was carried out for 1.5 hours. Then water
250 g was gradually added to obtain an aqueous solution of polyamide polyurea. Next, 40% glyoxal is an aqueous solution of 290%
After adjusting the pH to 3.5 with 37% hydrochloric acid, the mixture was stirred at 70° C. for 4 hours while keeping it warm. The reaction solution was cooled to obtain a thermosetting resin aqueous solution with a solid content of 50%. Example 3 In an apparatus similar to Example 1, 365 g (2.5 moles) of triethylenetetramine, 20 g of water, and 146 g of adipic acid were added.
(1 mol) was charged and subjected to dehydration condensation at 155 to 160°C for 4 hours. Next, add 60g (1 mol) of urea,
After removing ammonia at 145-150℃ for 3 hours,
After cooling to 130°C, 240g (4 moles) of urea was added, and ammonia removal reaction was carried out at 130-140°C for 3 hours. 230 g of water was gradually added to obtain an aqueous solution of polyamide polyurea. Next, 580 g (4 mol) of 40% glyoxal aqueous solution was added and the pH was adjusted to 3.5 with 50% sulfuric acid.
After adjusting to
A 40% thermosetting resin aqueous solution was obtained. Example 4 In exactly the same manner as in Example 1, an aqueous solution of polyamide polyurea was obtained. Next, 600g of 25% glutaraldebide aqueous solution
(1.5 mol) was added, the pH was adjusted to 3.0 with 50% sulfuric acid, and the mixture was stirred at 70° C. for 5 hours to obtain an aqueous thermosetting resin solution with a solid content of 36%. Reference Example 1 The thermosetting resin aqueous solutions according to the present invention of Examples 1 to 4 and, for comparison, Sumireze Resin 613 (Sumitomo Chemical Co., Ltd. trade name: melamine-formaldehyde resin), Sumitomo Chemical Co., Ltd. trade name: Sumiraze Resin 636 (Sumitomo Chemical Co., Ltd. trade name) : reaction product of polyamide polyurea and formaldehyde) and glyoxal as water resistant agents in the proportions shown in Table 1 (both solid content weight ratio), and nests were added so that the concentration was 55%. A paper coating composition was prepared.

[Table] (1) Preparation of coated paper The composition obtained in the above manner was applied to coated base paper with a basis weight of 85 g/m ² using a coating rod, with a dry solid content of approximately 15 g/m on one side. ² , and dried with hot air at 120°C for 30 seconds.
This coated paper was then supercalendered (roll temperature 60°C, roll linear pressure 60Kg/cm, 2 passes), and the humidity conditioned at 20°C and 65% RH, which was used as a test sample and subjected to various tests. . Second result
Shown in the table. (2) Various test methods (A) Physical properties of coating liquid PH of coating liquid Using glass electrode PH meter, measurement temperature 20℃ Viscosity of coating liquid Using B-type viscometer, rotation speed 60 rpm, measurement temperature 20℃ (B) Physical properties of coated paper Water resistance of coating film (a) Wet Rub method Approx.
ml was dropped, rubbed 7 times with a fingertip, the eluted amount was transferred to black paper, and the eluted amount was determined visually. The evaluation criteria were as follows. Water resistance (poor) 1-5 (excellent) (b) Wet Pick method Using an RI tester (manufactured by Mei Seisakusho),
After the coated surface was moistened with a water supply roll, it was printed, and the peeling off and damage on the coated surface were observed and judged with the naked eye. Judgment criteria is Wet Rub
Same as law. Determination of formaldehyde from coated paper
Compliant with JIS L-1041 solution phase extraction method (2) acetylacetone method The amount of formaldehyde was measured after sealing it in a polyethylene bag to prevent it from migrating or escaping. Ink transfer properties of coated paper: Printed using an RI tester using the following method.
Ink transferability was visually observed and judged. The evaluation criteria are (excellent) and 5 to 1 (poor). (a) Method A Printing is performed after water is dripped into the ink that is being mixed. (b) Method B: Print after moistening the surface to be coated with a water supply roll. (c) Method C: Print using a combination of methods A and B above. Whiteness and heat-resistant whiteness of coated paper The whiteness of coated paper before and after heat treatment in a hot air dryer at 150℃ for 30 minutes was determined by measuring the B value of a Hunter reflectance meter in accordance with JISP-8128. Tested. The larger the number, the better the whiteness. Blister resistance: Print on both sides of coated paper using off-circle ink using an RI tester, and after adjusting the humidity, immerse it in a heated silicone oil bath to show the lowest temperature at which blisters occur. .

【table】

Claims (1)

[Scope of Claims] 1 (a) a polyalkylene polyamine, (b) 0.2 to 1.0 mol of urea per mol of amino group in the polyalkylene polyamine of (a), and (c) the polyalkylene polyamine of (a) 1 mole of polyamide polyurea obtained by reacting 0.3 to 0.7 mole of dibasic carboxylic acid as a raw material; A method for producing an aqueous thermosetting resin solution, which comprises reacting with a dialdehyde selected from aldehydes. 2. The method according to claim 1, wherein the proportion of dialdehyde to be reacted with the polyamide polyurea is 0.05 to 1 mole per mole of total urea used in producing the polyamide polyurea. 3. The method according to claim 1, wherein the dialdehyde is glyoxal.