JPS60162899A - Papermaking method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention utilizes a cationic method obtained by reacting cyanoethylated starch with hydroxylamine or its salts as a P water agent or paper strength enhancer during paper making to convert the terminal nitrile group into an amidoxime. The present invention relates to a novel papermaking method characterized in that starch is added to an e-Rose slurry during papermaking.

Conventionally, in the paper manufacturing industry, cationized starch has been added internally during paper making and used as a paper strength enhancer, filler retention agent, size fixing agent, pH improver, etc. As alkaline starch in the presence of strong alkali.

For example, by reacting with a haloalkylamine such as 2-dimethylaminoethyl chloride or an aminochlorohydrin compound such as 3-chloro-2-hydroxyderovir dimethylamine, or in the presence of a catalytic amount of alkali. A commonly used method is to react with glycidyl amines such as diethylamine.

Also known is a method for producing cationized starch in which starch and an alkali metal salt of cyanami-P are reacted under alkaline conditions.

The present invention utilizes a completely new cationized starch obtained by reacting cyanethylated starch with human dixylamine or its salts in an aqueous system to convert the terminal nitrile group into an amidoxime in an almost neutral region.
It is characterized by its use as a paper strength enhancer, v aqueous property improver, filler retention agent, size fixing agent, and for improving printability.

The cationic starch used in the present invention is produced by the following reaction formula.

(2) H According to this method, cationized starch with a high degree of substitution can be obtained in high yield.

The cationized starch currently on the market is produced by the method described above, but most of them have a low degree of substitution and a poor yield. It is only slightly observed in colloid titration with potassium sulfonate (indicator: toluidine blue). Therefore, when it is added internally in paper making, adsorption to i4 Luso is insufficient, and it is considered to be completely unsuitable as a furnace water agent or filler retention agent, which requires some degree of cohesiveness, although it may be used as a paper strength enhancer.

On the other hand, the cationized starch used in the present invention can have a wide range of cation substitution degrees, ranging from high-substitution products for reactor water agents and filler retention agents that require cohesive properties to medium-sized ones for use as paper strength enhancers. It can easily be used for even replacement products.

Conventionally, polyacrylamide-based paper strength enhancers have been widely adopted as internally added paper strength enhancers, and their effects are considered to be much superior to starch-based ones. However, when the cationized starch of the present invention is used, this An effect on the paper direction comparable to that was observed, and in the printability test, it was found to have strong surface strength as shown in the examples. As for the high-substitution product, the freeness value was measured and it was found that it was sufficiently durable to be used as a reactor water agent. As described above, when the cationized starch according to the present invention is used, a remarkable effect is observed compared to conventional cationized starch.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited by these Examples.

Reference Example (a) Production of cyanethylated starch Oxidized starch (purity 87%) 46 f was placed in a backflow cooler,
Place in a Sanrokorpen equipped with a thermometer and stirrer, and add 1 part distilled water.
Add 50-1N -NaOH12,5- and 1 at 70°0.
Heat and stir for some time to dissolve. The amount of NaOH added was 5 mol/starch. Transfer the solution to a glass autoclave equipped with a stirrer, and add 13f acrylonitrile.
(100 mol of starch) was added and heated and stirred at 70° 0 for 5 hours. After the reaction was completed, unreacted acrylonitrile was quantified by the dodecyl mercaptan method. As a result, the reaction rate of acrylonitrile was 83 mol.

(b) Production of amidoximated starch 100 t of the above cyanethylated starch paste solution (18.6% product as starch) was placed in the same trilocol pen, and 9.49 t of hydroxylamine sulfate (100 mol of starch) was added to 5N of hydroxylamine sulfate. A solution dissolved in 20 mg of NaOH (based on hydroxylamine) is added, and the mixture is heated and stirred at 70°0 for 5 hours. After the reaction, a sample equivalent to 10 μm of starch was taken, diluted with 100 μm of distilled water, and titrated with 400% polyvinyl potassium sulfate solution using toluidine blue as an indicator.
A value of 2.5m was obtained. This value corresponds to a displacement pressure of 50.4 ratios for starch.

Examples will be described below, and the cationic starch used was one in which the conditions of the above production method were slightly changed, and only the substitution rate was changed.

Example 1 /4' A/P as LBKP (freeness 400
m1%O8'? ), adding 3% bread soil to pulp,
The cationized starch of the present invention was made into paper with a basis weight of 5,017 m'' and evaluated by its burst strength as a paper strength enhancer. The results are shown in Table 1.

Table 1 Qin Commercially available cationic starch 3-chloro-2-hydroxypropyldimethylamine modified product Commercially available preacrylamide Mannich compound I Dimethylamine and formalin modified product of lyacrylamide Example 2 NUKP as Nogurzo (Freeness 550 mt
The cationized starch of the present invention was evaluated as a paper strength enhancer based on the bursting strength of paper with a basis weight of 5097 m 2 and 3 g of pulp added to the bread soil. The results are shown in Table 2.

Table 2 Hata Same as Example 1 Whale Same as Example 1 However, Modification rate change Example 3 Use corrugated waste paper tin as Noyalp, commercially available I lyacrylamide anion modified product (modification rate 10%) to cationized starch 30% combination, 3 tb of bread soil added, tsubo@fiof
The cationized starch of the present invention was evaluated as a paper strength enhancer by papermaking and bursting strength under the conditions of 0.05%/m". The results are shown in Table 3.

Table 3 Example 4 Same as Jar Example 1 LBKP (Freeness 400 mO
F) Printing suitability was evaluated using a paper making and engineering GT printing suitability tester with the addition of 4 g of bread soil and a basis weight of 50 f/m2.

Printing conditions are spring A, ink tack 15, printing pressure 50.
Judgment was made based on the printing speed using the fluff chamber in Kg/cm''. The results are shown in Table 4.

Table 4 *Example 5 same as Example 1 F aqueous evaluation was carried out using a standard freeness tester using recycled waste paper, with the addition of 3 g of bread soil and the addition of a sample of 10.06%.

The results are shown in Table 5.

Table 5 *Same as Example 1

Claims (1)

[Claims] A papermaking method characterized in that, during papermaking, cationized starch obtained by reacting cyanoethylated starch with hydroxylamine or a salt thereof in an aqueous system and converting a terminal nitrile group into an amidoxime is added to a noclude slurry.