JPH09151329A - Anti-aging agent for starch paste - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To sufficiently prevent an increase in viscosity of a paste solution, gelation and generation of a precipitate, and to effectively prevent deterioration of paper strength and size when coated on paper. Provided is a novel anti-aging agent for starch paste solution. SOLUTION: The alkylene oxide adduct of rosin is contained as an active ingredient, and the oxyalkylene group contains 60 mol% or more of oxyethylene group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antiaging agent for starch paste liquid, and more specifically, for use as an adhesive for surface sizing agents, binders for pigment coating and internal additions in the paper industry. The present invention relates to a drug to be added to a self-modified starch paste solution for the purpose of preventing aging and stabilizing viscosity.

[0002]

2. Description of the Related Art In the paper manufacturing industry, starch paste solutions are used as various adhesives as described above, but these starch paste solutions age with time and cause various problems.
Aging of starch is a phenomenon in which amylose contained in a starch paste solution undergoes reassociation via hydrogen bonds and gels.

There are mainly two types of reassociation methods. One is a phenomenon in which reassociation spreads throughout the system and the entire liquid thickens and gels, in which case operability is impaired. The other is a phenomenon in which re-association proceeds in an extremely narrow range and precipitation of a gelled product occurs. When this starch paste solution is used for a size press solution, etc., the surface strength of the paper and the strength of the coating layer are improved. It is not preferable because it decreases.

As described above, the aging of the starch paste solution is caused by the reassociation of amylose. Therefore, generally, the higher the paste solution concentration and the lower the temperature, the easier the progress of the process. In recent years, the number of cases in which a high-concentration glue solution is applied by a gate roll coater has been increasing, and there is an increasing demand for prevention of aging of the starch paste solution.

Starch is most often used as an adhesive used in the paper manufacturing industry, and the performance required for these starches is low viscosity, particularly low viscosity at high concentration, and strong adhesive strength. , Excellent fluidity, excellent water retention, and resistant to aging.

Therefore, the starch used is enzyme-modified,
Oxidative modification, hydrolysis with acid or alkali, etherification,
Those which have been subjected to a chemical treatment such as esterification and cationization are used, and normally, these modified starches are gelatinized at a temperature of 100 ° C. or less before use.

On the other hand, in the paper manufacturing industry, due to demands for cost reduction and rationalization, the number of methods (self-denaturation method) in which starch is gelatinized at high speed under high temperature and high pressure at the same time, and at the same time, denaturation such as heat denaturation and thermochemical denaturation is increasing It's starting.

However, such self-modified starch has a marked aging tendency, and the demand for aging prevention is becoming more and more stringent with the increase in high-concentration coating, and various measures have been proposed for this purpose.

For example, as a method for preventing the aging of a paste solution, JP-A-55-129432 proposes a method of using xanthan gum, JP-A-3-258884 proposes the use of dextran, and JP-A-3-281640. The publication proposes the use of tamarin seed gum or pullulan.

By utilizing these polysaccharides,
Although a certain degree of effect is observed in increasing the viscosity of the starch paste solution and preventing gelation, the effect cannot be said to be satisfactory.

Further, Japanese Patent Publication No. 59-29601 discloses a fatty acid ester having 1 to 22 carbon atoms, a sulfuric acid ester of an aliphatic alcohol having 1 to 22 carbon atoms and salts thereof, and 1 to 22 carbon atoms. It has been proposed to use an ether of an aliphatic alcohol, an alkylbenzene sulfonic acid and a salt thereof, and JP-A-62-24033.
No. 6, gazette proposes the use of polyoxyethylene alkylphenyl ether, which is a nonionic surfactant.

However, although the use of these surfactants has a considerable effect on the increase in viscosity and the prevention of gelation, depending on the type and the amount added, precipitation or the formation of a surfactant is observed. Since it inhibits the hydrogen bond of the OH group of starch, it has a problem that the strength and the sizing property are reduced when it is used as a size press or a pigment coating paint.

Further, Japanese Patent Application Laid-Open No. 61-36386 proposes a method of combining a higher alcohol having 1 to 18 carbon atoms, an ethylene oxide adduct of a higher fatty acid and polyvinyl alcohol having a carboxyl group. Although the paper strength can be prevented to some extent even by the method, when used as a coating paint, there is a drawback that the paint viscosity increases.

Further, Japanese Patent Laid-Open No. 1-1778 proposes a method in which a nonionic acrylamide-based polymer and an alkaline aqueous solution of a styrene-based polymer are used in combination, but in order to prevent an increase in viscosity and gelation. Although some effect is recognized, the effect is not satisfactory. Further, JP-A-4-174795 proposes the use of anhydrous silica fine powder, but the effect is not satisfactory.

[0015]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is possible to sufficiently prevent the viscosity increase of a paste solution, gelation and the generation of precipitates, and to apply it to a paper. It is an object of the present invention to provide a novel anti-aging agent for a starch paste solution, which can effectively prevent deterioration of paper strength and size.

[0016]

Accordingly, the present invention is based on the general formula

[0017]

Embedded image R ₁ —O— (AO) _n —R ₂ (wherein R ₁ is a residue of rosin or a derivative thereof, and AO is 6
An oxyalkylene group containing 0 mol% or more of an oxyethylene group, n is an integer of 5 to 45, R ₂ is a hydrogen atom or an alkyl group or an alkenyl group having 1 to 12 carbon atoms, and is an alkylene of a rosin group. It is characterized by containing an oxide adduct as an active ingredient.

In the present invention, it is preferable that the above antiaging agent contains polyacrylamides and / or polyvinyl alcohols.

In the compound represented by the chemical formula 2, R ₁
As the rosin residue represented by, a residue such as tall rosin, gum rosin and wood rosin can be used. It is also possible to use residues of derivatives of these rosins, such as asymmetric reaction products, polymers, and hydrogenated products, and some of the residues of these rosins or their derivatives are esterified. Good. And these can be used individually or in mixture of 2 or more types.

In the compound of the chemical formula 2, the oxyalkylene group represented by AO represents an oxyethylene group alone or a mixed oxyalkylene group of an oxyethylene group and an oxypropylene group and / or an oxybutylene group.

When it is a mixed oxyalkylene group,
It is necessary to contain at least 60 mol% or more of an oxyethylene group, and if the oxyethylene group is less than 60 mol%, a sufficient antiaging effect of the paste solution cannot be obtained. The addition form of the oxyethylene group and the oxypropylene group and / or the oxybutylene group may be either block addition or random addition.

In the compound shown in Chemical formula 2, the number of added oxyalkylene groups, n, must be in the range of 5 to 45. When n is less than 5, increase in viscosity of the paste solution cannot be sufficiently prevented, and when n is more than 45, increase in viscosity can be prevented, but problems such as paper strength reduction and size reduction occur.

In the compound shown in Chemical formula ₂ , R ₂ is a hydrogen atom or an alkyl group or an alkenyl group having 1 to 12 carbon atoms. If the number of carbon atoms in R ₂ exceeds 12, it is not possible to sufficiently prevent the viscosity of the paste solution from increasing.

The amount of the antioxidant added to the starch paste solution of the present invention is 0.1 to 20% by weight, preferably 0.5 to 10% by weight, based on the starch paste solution. If it is less than 0.1% by weight, the effect of preventing aging is not sufficient, and if it exceeds 20% by weight, the paper strength tends to decrease.

There is no particular limitation on the method of addition to the starch paste solution,
The starch may be added either before or after gelatinization, but it is usually suitable to add it immediately after gelatinization.

The anti-aging agent for a starch paste solution of the present invention, when used in combination with polyacrylamides or polyvinyl alcohols, not only exerts a further excellent anti-aging effect but also exerts an effect in improving paper strength. .

The polyacrylamides and polyvinyl alcohols used in combination with the antiaging agent in the present invention are not particularly limited. Generally, those commonly used in the paper industry for clear coats, pigment coating binders, and internal additions can be used, but preferably, anionic polyacrylamides having an anionic monomer content of 5 mol% or less, both. The combined use with ionic polyacrylamides or nonionic polyacrylamides is preferable in that the viscosity of the paste solution is not increased.

The method for producing the compound represented by the above chemical formula 2 is not particularly limited, but it is generally produced as follows. That is, rosin as a raw material and an alkaline substance such as 0.1 to 5% by weight of potassium hydroxide or sodium hydroxide with respect to rosins as a catalyst are charged in a pressure reactor as a catalyst, and after deoxidation treatment, It can be produced by dropping an alkylene oxide at a temperature of 100 to 200 ° C. under a pressure of 1 to 5 kg / cm ² and carrying out an addition reaction.

Further, it can be produced by addition-polymerizing the alkylene oxide moiety in advance and then subjecting the polyalkylene oxide and the rosin to an esterification reaction.

The starch acting as the antiaging agent of the starch paste solution of the present invention may be any one commonly used for surface size, pigment coating binder, and internal addition, such as sweet potato starch, potato starch, wheat flour. Unmodified starch such as starch, corn starch, rice starch, tapioca starch, and various modified starches such as oxidized starch, etherified starch, esterified starch, and self-modified starch modified by the self-denaturing method Can be applied.

[0031]

The antiaging agent for a starch paste solution of the present invention prevents the viscosity increase of the starch paste solution, gelation, and the formation of precipitates, and reduces the strength when used as a size press or a pigment coating paint, It is not always clear why the reduction in size can be prevented, but perhaps the rosin skeleton having a polycyclic structure inhibits the reassociation of amylose in starch, and when used as an adhesive, the rosin skeleton has a cyclic structure, resulting in a paper structure. It is considered to contribute to the improvement of strength.

When used in combination with polyacrylamides or polyvinyl alcohols, the dispersion-stabilizing action of these water-soluble synthetic polymers stabilizes the dispersion of the amylose in a fine state even when a re-association product of amylose is produced. It is considered that not only prevent the aging of the starch paste solution but also improve the strength because the water-soluble synthetic polymer itself acts as an adhesive because it inhibits the growth.

[0033]

Therefore, by adding the anti-aging agent of the present invention to the starch paste solution, the viscosity of the starch paste solution is not increased, gelation and precipitation are not generated, and the aging of the starch paste solution is prevented. Moreover, when used as a size press or as a pigment coating paint, the strength and the size are not deteriorated.

Further, by using the antiaging agent of the present invention in combination with polyacrylamides or polyvinyl alcohols, the effect of preventing the aging of the starch paste solution is further enhanced and the strength is further improved.

[0035]

EXAMPLES The present invention will be specifically described below based on examples, but the present invention is not limited to these examples.

[Preparation of Antiaging Agent] Example 1 Tall rosin (Harima Chemical Co., Ltd., Hartall RW)
W, acid value 167. In the following examples and comparative examples, the same) 336.0 g and 85% potassium hydroxide (first-grade reagent) 3.36 g (rosin ratio 1% by weight) were charged into a 1 liter glass autoclave, and degassing under reduced pressure was performed. Then, at 130 ° C. ± 10 ° C. and 1.0 to 2.5 Kg / cm ² , 440.0 g of ethylene oxide (10 mol per 1 mol of rosin).
Mol) was added slowly. After the completion of addition, the mixture was aged for 2 hours, cooled, and the pH was adjusted to 6 to 7 with acetic acid to obtain the antioxidant of Example 1.

Examples 2, 4 to 6 The aging prevention of Examples 2 and 4 to 6 was performed in the same manner as in Example 1 except that the kind, amount and addition order of alkylene oxide were changed as shown in Table 1. I got an agent.

In Table 1, EO is ethylene oxide and PO is propylene oxide. For example, "E
"O / PO = 20/10" means that a mixture of 20 mol of ethylene oxide and 10 mol of propylene oxide was used per 1 mol of rosin, and "EO-
"PO = 20-10" means that after adding 20 mol of ethylene oxide to 1 mol of rosin, another 10
It shows that mol propylene oxide was added dropwise. The following notations are also the same.

Example 7 21.1 g of butyl alcohol (first-grade reagent) and 0.87 g of 85% potassium hydroxide (first-grade reagent) (ratio to butyl alcohol: 2% by weight) were charged in a 1-liter glass autoclave and depressurized under reduced pressure. After performing the manual operation, 130 ℃ ± 10
° C., ethylene oxide 440 1.0~2.5Kg / cm ^2.
0 g (35 mol per mol of rosin) was added slowly. After aging for 2 hours after addition, cool and add pH with acetic acid.
Was adjusted to 6 to 7 to obtain a butyl alcohol ethylene oxide adduct.

Then, 403.9 g of the obtained butyl alcohol ethylene oxide adduct and 84.
0 g and 2.44 g of anhydrous sodium p-toluenesulfonate (first-class reagent) as an esterification catalyst (ratio of raw material to 0.5% by weight) were charged in a 1-liter four-necked flask, a thermometer, a nitrogen inlet tube, After attaching a drainage tube and a stirring rod, the temperature was raised in a nitrogen stream, and while dehydrating, the reaction was allowed to proceed at 220 ° C. for 5 hours and then cooled to obtain the antioxidant of Example 7.

Example 8 An antiaging agent of Example 8 was obtained in the same manner as in Example 7 except that 1-decanol (primary reagent) was used instead of butyl alcohol.

Example 9 An antiaging agent of Example 9 was obtained in the same manner as in Example 1 except that gum rosin (acid value 170) was used in place of tall rosin.

Example 10 Example 10 was repeated except that wood rosin (acid value 155) was used in place of tall rosin.
Anti-aging agent was obtained.

Example 11 An antiaging agent of Example 11 was obtained in the same manner as in Example 1 except that polymerized rosin (acid value 150) was used in place of tall rosin.

Example 12 The same procedure as in Example 1 was repeated except that asymmetric asymmetric tall rosin (manufactured by Harima Kasei Co., Ltd., Handy's T-100, acid value 165) was used instead of tall rosin. 12
Anti-aging agent was obtained.

Example 13 Hydrogenated rosin instead of tall rosin (Rika Hercules
An anti-aging agent of Example 13 was obtained in the same manner as in Example 1 except that stevelite resin, acid value 162, manufactured by Co., Ltd. was used.

Comparative Example 1 Instead of tall rosin, stearic acid (produced by NOF CORPORATION,
Except for using beef tallow stearate, acid number 203),
The same operation as in Example 1 was carried out to obtain the antioxidant of Comparative Example 1.

Comparative Example 2 Instead of tall rosin, cetyl alcohol (Nippon Rika
An antiaging agent of Comparative Example 2 was obtained in the same manner as in Example 1 except that Conol 1695, hydroxyl value 230, manufactured by Co., Ltd. was used.

Comparative Examples 3 to 6 Antiaging agents of Comparative Examples 3 to 6 were obtained in the same manner as in Example 1 except that the kind, amount and addition order of alkylene oxide were changed as shown in Table 1. .

[Preparation of starch paste solution by self-denaturation method] Unmodified corn starch powder was dispersed in water to form a uniform slurry with a solid content concentration of 30%, which was used as an oxidizing agent for 100 parts by weight of starch solids. 1.0 of ammonium persulfate
Parts by weight, 1.0 solid part by weight of sodium carbonate for pH adjustment, and 0.01 part by weight of caustic soda were added and sufficiently stirred to obtain a uniform slurry of pH 9.5 to 10.0. This slurry was placed in a 1-liter autoclave at 140 ° C. for 5
It was cooked for a minute to obtain a starch paste solution. (Hereinafter simply referred to as "starch paste solution")

[Addition of Antiaging Agent to Starch Paste Solution] Each of the antiaging agents obtained in Examples 1-2, 4-13 and Comparative Examples 1-6 was added to the above-mentioned self-modified starch paste solution in starch 100. 5 parts by weight relative to solid parts and an antiseptic (manufactured by Shinto Paint Co.
0.1 part by weight of neocintol 5087) was added, and the mixture was diluted with warm water so that the solid concentration of starch was 10%. In Example 3, the same antiaging agent as in Example 2 was used, and the addition amount was 1 part by weight. Further, Comparative Example 7 was carried out without adding an antioxidant.

[Performance Test] 1. Storage stability test The starch paste solution containing the antioxidant of each of the above Examples and Comparative Examples was stored at 60 ° C and 40 ° C for 24 hours, and the viscosity stability was measured. To measure the viscosity, use a BL type viscometer,
The viscosity at the storage temperature was measured. (Measurement speed:
60 rpm, rotor: No. 1-3)

2. Measurement of gel generation amount Regarding the paste solution subjected to the above storage stability test, the paste solution after storing for 24 hours was diluted with warm water to a starch solid content concentration of 5%, and
Centrifugation was carried out at 00 rpm for 20 minutes, and the precipitated gel component was separated by filtration and calculated from the dry weight.

3. Coating Test on Paper The starch paste solution of each of the above-mentioned Examples and Comparative Examples was diluted with warm water so that the solid concentration of starch was 5%, and was coated on paper. The quality of the base paper (acid base paper) used in the test was as follows. Basis weight: 70 g / cm ² Steckigt Sizing degree: 2 seconds Internal additive chemicals (addition ratio to pulp) Talc: 16% Emulsion sizing agent: 0.05% (Harima Chemicals Co., Ltd., Hersize NES405) Sulfuric acid band: 3%

For coating, a lab size press manufactured by Kumagai Riki Kogyo Co., Ltd. was used and dried at 110 ° C. for 180 seconds with a rotary drum dryer manufactured by Kumagai Riki Kogyo Co., Ltd.

A Surface strength of coated paper (suitability for RI printing) Device: RI tester (manufactured by Kumagai Riki Kogyo Co., Ltd.) Speed: 60 rpm Ink: Tack 25 (manufactured by Toyo Ink Co., Ltd.)

B Size Property (Water Spot Measurement Method) 10 μl of distilled water was dropped on the paper surface, and the time required for the distilled water to permeate was measured.

[Test Results] Raw material composition of the antioxidant and
The results of each of the above tests are shown in Table 1.

[0059]

[Table 1] As can be understood from the above test results, the anti-aging agent for a starch paste solution of the present invention, compared with the conventional anti-aging agents, does not affect the surface strength and sizing property when coated, and It has the effect that the thickening of the paste solution and the generation of gel can be effectively prevented.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiro Abe, 4 Harima Kasei Co., Ltd., 671 Mizusui, Noguchi-cho, Kakogawa-shi, Hyogo Prefecture

Claims (2)

[Claims] 1. A compound represented by the general formula: R ₁ —O— (AO) n —R ₂ (wherein R ₁ is a residue of rosin or a derivative thereof, and AO is 6).
An oxyalkylene group containing 0 mol% or more of an oxyethylene group, n is an integer of 5 to 45, R ₂ is a hydrogen atom or an alkyl group or an alkenyl group having 1 to 12 carbon atoms, and is an alkylene of a rosin group. An antiaging agent for starch paste liquid, which contains an oxide adduct as an active ingredient 2. An antiaging agent for a starch paste solution according to claim 1, which contains polyacrylamides and / or polyvinyl alcohols.