JPS5853653B2 - Method for producing cationic thermosetting resin aqueous solution - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an aqueous cationic thermosetting resin solution that is useful as a wet strength improver for paper, has a high solid content concentration, and is highly stable.

It is well known that polyamide polyamine-epichlorohydrin resins are useful as paper strength improvers, especially wet strength improvers, as described in Japanese Patent Publication No. 35-3547, for example.

However, the polyamide polyamine-epichlorohydrin resin specifically disclosed in the publication is usually obtained in the form of an aqueous solution with a concentration of 10 to 30%, but unless the viscosity of the product is increased, it may not have sufficient wet strength when processed into paper. On the other hand, if the product viscosity is increased, the viscosity increases over time and eventually gels, which is an inconvenient drawback.In order to lower the apparent viscosity, this type of product is manufactured at a low temperature of about 10℃. Currently, it is commercialized in concentrated concentrations.

Therefore, since the concentration is low, the volume of the product increases, which is extremely disadvantageous industrially in handling such as transportation.

For these reasons, the present inventors have developed a polyamide polyamine-epichlorohydrin that not only has excellent effects as a wet strength improver, but also has a high solid content concentration and is highly stable, such as not causing gelation over a long period of time. As a result of intensive studies to produce an aqueous resin solution, we discovered that the above objective could only be achieved if the ratio of raw material compounds, intermediates (polyamide polyamines), and the viscosity of the final reactants were regulated within specific ranges. This led to the present invention.

That is, the present invention synthesizes a polyamide polyamine by heating and condensing an aliphatic dicarboxylic acid and a polyalkylene polyamine in the presence of one or more sulfonic acids such as sulfuric acid, para-toluenesulfonic acid, and benzenesulfonic acid. Next, in a method for producing a cationic thermosetting resin aqueous solution by reacting the polyamide polyamine with epichlorohydrin in an aqueous solution, (1) aliphatic dicarboxylic acid and polyamide at a molar ratio of 1:1.0 to 1.2; The alkylene polyamine is added to the polyamide polyamine produced in the presence of one or more sulfonic acids in an amount of 0.005 to 0.1 times the mole of the polyamine.
Viscosity in 0% aqueous solution (25°C) is 400-1.0
(2) Next, 16 to 1.7 times the mole of epichlorohydrin to the secondary amino group in the polyamide polyamine was added in an aqueous solution with a concentration of 15 to 50%, and the product was 15 of
% aqueous solution (25°C) viscosity is 30-150c
ps, (3) dilute with water as necessary so that the solid content in the reaction product is 15 to 30%, and (4) heat the aqueous solution of the obtained reaction product at 25°C. p in
Adjust so that H is 3-5.

This is a method for producing a cationic thermosetting resin aqueous solution.

The present invention will be specifically explained below.

Suitable aliphatic dicarboxylic acids for use in the present invention include malonic acid, succinic acid, geltaric acid, adipic acid, and sebacic acid, but adipic acid is particularly preferred from an industrial standpoint.

Suitable polyalkylene polyamines include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, iminobispropylamine, and the like.

Regarding the reaction molar ratio of aliphatic dicarboxylic acid and polyalkylene polyamine, the smaller the molar ratio of polyalkylene polyamine, the more polyamide polyamine with a crosslinked structure tends to be produced, resulting in poor stability of the final product; There is a tendency that the higher the molar ratio of the polyamide polyamine, the more difficult it is to increase the degree of polymerization of the polyamide polyamine.

Furthermore, the higher the degree of polymerization of the produced polyamide polyamine, the greater the effect of improving the wet strength of the final product on paper, but the stability of the final product itself will be deteriorated.

For this reason, the reaction molar ratio of aliphatic dicarboxylic acid and polyalkylene polyamine is preferably in the range of 1:1.0 to 1.2. The time required to increase the viscosity to a certain level can be reduced by about 40% compared to when no sulfonic acids are used.

Moreover, when a certain amount was used, the stability of the final product did not worsen, but rather showed a tendency to improve.

This is completely unexpected from the conventional technology.
When other catalysts such as phosphoric acids are used, the stability of the final product becomes extremely poor even though the reaction is promoted, which shows that the addition of sulfonic acids is of great significance in the present invention.

Furthermore, by shortening the reaction time, the thermal energy required for the reaction can be reduced, and the reaction cycle can also be shortened, leading to an increase in the production amount per unit time.

As the sulfonic acids used in the present invention, sulfuric acid, benzenesulfonic acid, and para-toluenesulfonic acid are preferable, and the amount used is 0.00% per mole of the polyamine used.
005 to 0.1 mole, preferably 0.01 to 0
．． A range of 0.05 mol is good.

If it is less than 0.005 mol, the reaction promotion effect is small, and if it is 0.005 mol or less,
, if the amount exceeds 1 mol, the final product will have poor stability over time;
When stored at 50°C, gelation occurs within a few days.

At the same time, from the viewpoint of the performance and stability of the final product, it is necessary to adjust the reaction so that the viscosity of the 50% aqueous solution of polyamide polyamine produced is 400 to 1,000 cps at 25°C.

That is, the viscosity in a 50% aqueous solution is 400 cps.
If it is lower, the final product will not exhibit a sufficient wet strength improvement effect, and if it exceeds 1000 cps, the stability of the final product will deteriorate, leading to gelation.

The appropriate temperature for the polyamidation reaction is 100 to 250°C, preferably 130 to 200°C, and the reaction is continued until the viscosity of a 50% aqueous solution is 400 to 1,000 cps.

Next, the polyamide polyamine aqueous solution thus obtained is reacted with epichlorohydrin in an aqueous solution at a temperature in the range of 30 to 80°C.

The reaction ratio at this time is such that the ratio of secondary amino groups in the polyamide polyamine to epichlorohydrin is 1:1.6 to 1.
．． A range of 7 is preferable.

If the molar ratio of epichlorohydrin is less than 1.6, the final product will have poor stability over time, and gelation will occur within a few days when stored at 50°C.

On the other hand, if the molar ratio of shrimp chlorohydrin exceeds 1.7, the desired wet strength cannot be obtained, and unreacted epichlorohydrin increases, which is undesirable in terms of odor.

The reaction between the polyamide polyamine and epichlorohydrin is carried out in an aqueous solution with a concentration of 15-50%, preferably 15-40%, and the viscosity of the product is 30-150 cps at 25°C when the solid content of the product is 15%. is the end point of the reaction.

If the viscosity at this time is lower than 30 cps, the wet strength will not be sufficient, while if it exceeds 150 cps, the stability of the product will deteriorate, and when it is added to the pulp slurry in the papermaking process, it will cause strong foaming, making it difficult for the papermaking process. Not only will this make it difficult to do so, but it will also damage public sentiment.

Once the reaction solution has reached the desired viscosity, it is diluted with water if necessary to a solids concentration of 15-30%, and then an acid such as hydrochloric acid, sulfuric acid, phosphoric acid, or formic acid is added to stop the reaction. , acetic acid, etc. are added to adjust the pH to 3 to 5 to obtain the desired product.

Thus, according to the method of the present invention, an aliphatic dicarboxylic acid and a polyalkylene polyamine are reacted in a specific ratio and in the presence of a specific amount of sulfonic acids such that the viscosity of the polyamide polyamine falls within a specific range, and then The cationic thermosetting resin aqueous solution obtained by reacting the polyamide polyamine obtained in 1. Approximately 10% is required to provide an excellent wet paper strength enhancing effect equivalent to or better than polyamide polyamine-epichlorohydrin resin produced by a known method, and to form a stable product with the resin produced by a known method. However, it can be made into a product with a high concentration of 15 to 30%, and has extremely excellent properties such as excellent stability.

In addition, the aqueous resin solution obtained by the method of the present invention can be used not only as a wet strength improver for paper, but also as a retention aid for additives added during the papermaking process, and to improve papermaking speed. It can also be used as a water flow improver or a settling and flocculant for removing fine particles from wastewater such as industrial wastewater.

The present invention will be explained below with reference to Examples.

Example 1 103 g (1.0 mol) of diethylenetriamine, io, y of water, and 146 g (1.0 mol) of adipic acid are placed in a 50 Qm four-way flask equipped with a thermometer, reflux condenser, and stirring bar.
and 98% sulfuric acid; 1' (0.02 mol) were charged, the temperature was raised while removing water, and the reaction was carried out at 155 to 160°C for 12 hours.

Thereafter, 210 g of water was gradually added to obtain an aqueous solution of polyamide polyamine.

The polyamide polyamine aqueous solution had a solids content of 50.3% and a viscosity of 690 cps (25°C).

12' of this polyamide polyamine aqueous solution in another flask.
1 (0.3 mol) and water 26 (Bi'), and 44.4 & (0.48 mol) of epichlorohydrin at 25°C.
It was dropped in 0 minutes.

The temperature was then raised to 60° C., and kept at the same temperature. When the viscosity of the reaction solution reached 245 cps (25° C.), 225 g of water was added, and the pH was then adjusted to 4.2 with hydrochloric acid.

The resulting product had a solid content of 15.3% and a viscosity of 91 cps (
25°C).

This product did not gel even after being stored at 50°C for 30 days.

Example 2 Diethylenetriamine 10 was added to a reactor similar to Example 1.
:l (1.0 mol), water 11. Adipic acid 138.79
(0.95 mol) and para-toluenesulfonic acid 6.9
．． 9 (0.04 mol), and while removing water, 16
It was made to react at 0-165 degreeC for 8 hours.

Thereafter, 200 g of water was gradually added to obtain a polyamide polyamine aqueous solution.

This product has a solid content of 50.2% and a viscosity of 530 cps (25
°C).

Next, the entire amount of this polyamide polyamine aqueous solution was mixed with 60% water.
1, and 148 iL of epichlorohydrin (6 mol) was added dropwise thereto at 30° C. over 15 minutes.

Then, the reaction solution was stirred while keeping it warm at 55 to 60°C until the viscosity of the reaction solution was 28.
When it reaches 0 cps (258C), add 125g of water.
was added, and the pH was adjusted to 3.5 with hydrochloric acid.

The resulting product had a solids content of 25.6% and a viscosity of 193 cps.
(25°C).

This product did not gel even after being stored at 50°C for 30 days.

The viscosity of this product when diluted to 15% is 57c.
ps (25°C).

Example 3 Diethylenetriamine 10 was added to a reactor similar to Example 1.
:l (1 mol), water 10g, adipic acid 138.79 (
0.95 mol) and 3 g (0.03 mol) of 98% sulfuric acid
was charged and reacted at 155 to 156°C for 13 hours while removing water.

Thereafter, 205 g of water was added to obtain a polyamide polyamine aqueous solution.

This product has a solid content of 50.2% and a viscosity of 540 cps (2
5°C).

In another flask, 125 g (0.3 mol) of this 50% polyamide polyamine aqueous solution and 186 g of water were charged, and 44 g of epichlorohydrin was added. i (0.48 mol) was added.

The viscosity was 360 cps (at 25°C) when stirred at 60°C.
), the pH was adjusted to 3.6 with hydrochloric acid.

The resulting product had a solid content of 28.6% and a viscosity of 348 cps.
(25°C).

This product did not gel even after being stored at 50°C for 30 days.

In addition, if this thing is diluted to 15%, it will be 73 cps (25
°C).

Example 4 In a reactor similar to Example 1, 131.9 (1 mol) of iminobispropylamine, 10 g of water, 146 g of adipic acid were added.
(1 mol) and 6.9 g of para-toluenesulfonic acid (
0.04 mol), and while removing water, 160 to 16
The mixture was reacted at 5° C. for 6.5 hours, and then 235 g of water was added to obtain a polyamide polyamine aqueous solution.

This product has a solid content of 50.1% and a viscosity of 770 cps (25
°C).

The entire amount of this polyamide polyamine aqueous solution and 920 g of water were placed in another flask, and then 1 liter of epichlorohydrin was added.
41 (1.6 mol) was charged and stirred while keeping warm at 60°C.

When the viscosity of the reaction solution reached 180 cps, the pH was adjusted to 4.2 with hydrochloric acid and further diluted with water to a solid content of 15%.

This has a viscosity of 66 cps (25°C) and
It did not gel even after being stored at 0°C for 30 days.

Example 5 Diethylenetriamine 10 was added to a reactor similar to Example 1.
3. ! 9 (1 mol), 10 g of water 1 adipic acid 1.38.
79 (0,95 mol), and 8 g (0,0 mol) of 98% sulfuric acid
8 mol) and reacted at 155 to 156° C. for 11 hours while removing water.

Thereafter, 210 g of water was added to obtain a polyamide polyamine aqueous solution.

This product has a solid content of 50.1% and a viscosity of 550 cps (25
℃).

In another flask, 126 g (0.3 mol) of this 50% polyamide polyamine aqueous solution and 137 g of water were charged, and 44.4 g (0.48 mol) of epichlorohydrin was added.

Stir while keeping warm at 60℃, viscosity is 500cps (25℃)
When the pH reached 3.6, the pH was adjusted to 3.6 with hydrochloric acid, and the solution was further diluted with water to a solid content of 30%.

It has a viscosity of 320 cps (25°C) and
Further, it did not gel even after being stored at 50°C for 30 days.

The viscosity when diluted to 15% is 62c.
ps (25°C).

Comparative Example 1 Diethylenetriamine 10 was added to the same reactor as Example 1.
3 g (1 mole), 1 water (Bi' and 138 adipic acid)
．． 7 g (0.95 mol) was charged and reacted at 155 to 156 °C while removing water without adding sulfonic acids, but the viscosity of the 50% aqueous solution was 510 cps (25 °C).
It took 20 hours to reach this point.

Comparative Example 2 Diethylenetriamine 10 was added to the same reactor as Example 1.
:l (1 mol), water 1 (Bi', adipic acid 138.1
(0.95 mol) and para-toluenesulfonic acid 0.5
g (0,003 mol), and while removing water, 160
Although the reaction was carried out at ~165°C, it took 12 hours for the 50% aqueous solution to reach a viscosity of 510 cps (25°C).

Comparative Example 3 In a reactor similar to Example 1, 103 g (1 mole) of diethylene) IJ amine, 10.9 g of water, 138 g of adipic acid,
'l (0,95 mol) and 15 g (0,1 mol) of 98% sulfuric acid
5 mol) and reacted at 155 to 156° C. for 10 hours while removing water.

Thereafter, 215 g of water was added to obtain a polyamide polyamine aqueous solution.

This product has a solid content of 50.2% and a viscosity of 560 cps (2
5°C).

This 50% polyamide polyamine aqueous solution 12 (1 (0.3 mol)) and 138 g of water were placed in another flask, and 44.4.9 (0.48 mol) of epichlorohydrin was added thereto.

The viscosity was 490 cps (25°
When reaching C), adjust the pH to 3.4 with hydrochloric acid,
When further diluted with water to 25% solids, the viscosity is 195 cp.
s (25°C).

This product gelled in 3 days when stored at 50°C.

The viscosity when diluted by 15% is 64 cps.
(25°C).

Comparative Example 4 Polyamide polyamine aqueous solution obtained in Example 1 [solid content 5
0.3%, viscosity 690 cps (25°C)] 12'l
(0.3 mol) and 254 g of water into a four-eye flask, and add 41.6 j of epichlorohydrin! (0.45 mol) was added dropwise over 20 minutes at 25°C.

Then, the mixture was stirred at 55°C until the viscosity of the reaction solution was 185.
cps (25°C), 215 g of water was added and the pH was adjusted to 3.6 with hydrochloric acid.

The resulting product had a solid content of 15.1% and a viscosity of 68 cps (
25°C).

This product gelled in 2 days when stored at 50°C.

Comparative Example 5 The same reaction as in Example 1 was carried out, but the reaction was stopped when the viscosity of the reaction solution reached 45 cps at the stage of epichlorohydrin modification, the pH was adjusted to 4 with hydrochloric acid, and the solid content was reduced to 15% with water. diluted to

The viscosity was 17.8 cps.

Comparative Example 6 Diethylenetriamine 10 was added to the same reactor as in Example 1.
311.0 mol), 10 g of water, 146 g of adipic acid (1
, 0 mol) and 2 g (0.02 mol) of 98% sulfuric acid were charged and reacted at 150 to 153° C. for 3 hours while removing water, and then 205 g of water was added to obtain an aqueous polyamide polyamine solution.

This product has a solid content of 50.2% and a viscosity of 230 cps (
25°C).

Transfer the entire amount of this polyamide polyamine aqueous solution to another flask, add 850 g of dilution water and 14 g of epichlorohydrin.
8i (1.6 mol) was added, stirred at 65°C,
When the viscosity reached 250 cps (25° C.), the pH was adjusted to 4.5 with hydrochloric acid, and then diluted to a solid content of 15%.

The viscosity of this was 92 cps (25°C).

Comparative Example 7 Polyamide polyamine aqueous solution 125&( obtained in Example 3)
0.3 mol), 200 g of water and epichlorohydrin 5
0g (0.54 mol) was heated and stirred at 65℃, and the viscosity was 37.
When the temperature reaches 0 cps (25℃), adjust the pH with hydrochloric acid.
Adjusted to 3.6.

The resulting product had a solids content of 28.5% and a viscosity of 354 cps.
(25°C).

When this material is diluted to 15%, the viscosity is 74 cps (2
5°C).

Reference Example 1 Using each of the aqueous resin solutions obtained in Examples 1 to 5 and Comparative Examples 3 to 7, a paper making test was conducted using the TAPPI standard paper making method, and the performance of the resulting paper was measured.

Paper making conditions Valve used: NBKP/LBKP=1/1 mixed product beating
Solubility: 435CC (Canadian standard furnace water dust) Resin addition amount: 20.8% (relative to pulp) Heat treatment conditions: 110°C x 10 minutes Paper making average weight: 80g/rrl The results are shown in Table 1.

Claims (1)

[Claims] 1. A polyamide polyamine is synthesized by heating and condensing an aliphatic dicarboxylic acid and a polyalkylene polyamine, and then the polyamide polyamine is reacted with epichlorohydrin in an aqueous solution to produce a cationic thermosetting resin aqueous solution. (1) The molar ratio is 1:1.0 to 1.2.
An aliphatic dicarboxylic acid and a polyalkylene polyamine are prepared in a 50% aqueous solution (25° C.) of the resulting polyamide polyamine in the presence of one or more sulfonic acids in an amount of 0.005 to 0.1 times the mole of the polyamine. (2) Next, 1.6 to 1.7 times the mole of epichlorohydrin to the secondary amino groups in the polyamide polyamine was added at a concentration of 15 to 50%. in an aqueous solution of and 1 of the product
Viscosity in 5% aqueous solution (25℃) is 30-150c
ps, (3) dilute with water as necessary so that the solid content in the reaction product is 15 to 30%, and (4) heat the aqueous solution of the obtained reaction product at 25°C. p in
Adjust so that H is 3-5. A method for producing a cationic thermosetting resin aqueous solution, characterized by: