JP2003512541A - Cation-modified polysaccharide - Google Patents

Abstract

  (57) [Summary] Modified polysaccharide with increased surface charge. The polysaccharide has been modified to include a cationic polymer, preferably a polyquaternary amine, and has a surface charge of about +5 mV to about +20 mV. The modified polysaccharide can be properly incorporated into papermaking furnishes, resulting in increased retention.

Description

Detailed Description of the Invention

FIELD OF THE INVENTION The present invention relates to modified polysaccharides as fillers and reinforcing agents for paper and board products.
More specifically, it relates to modified polysaccharides having a higher surface charge.

[0002] One goal in the context papermaking invention is to increase the amount of filler in the final product as the less the amount of fiber is a relatively expensive component. Increasing the amount of filler should not adversely affect the sizing properties of the paper or other required properties. Of the several fillers, starch is an attractive material due to its low cost and ready availability. In general, unmodified starch does not fully set in the papermaking furnish due to its lack of effective interaction with fibers and fixing aids. Despite these drawbacks, various methods of using starch as a filler in papermaking have been investigated.

In most paper and board manufacturing, starch is fully cooked.
d), used in size press. Size press starch
) May include additives that impart desirable properties to the paper or paperboard, such as improved printability, stiffness, bondability, dusting, and surface strength. Cationic starch is usually added at the wet end of the paper machine, which can improve the strength properties of the paper and the fixing rate of fine particles. Other charged synthetic polymers can be combined with cationic starch to improve overall particulate retention.

Untreated and unmodified starch particles cannot be added to the wet end of a paper machine because their fixing rate is unacceptably low. Raw starch has little particle surface charge when slurried in water. This lack of surface charge results in weak interaction with charged fixing aids and / or fibers. Strong interaction (
Without (for example, chemical ties) the starch cannot be fully anchored in the paper machine system. Mechanical filtration of the starch particles allows some degree of anchoring of the starch in the fibrous web, but such anchoring requires a particular type of headbox arrangement.

However, by imparting a surface charge to the raw starch particles, the fixation of the starch in the web can be greatly increased. Such increased starch fixing is achieved by using fixing aids that form a cross-linking bond between the charged starch particles and the fiber surface. Charge imparting to raw starch has traditionally been accomplished by chemical modification of the starch by covalently attaching certain functional groups (eg, quaternary amine groups) to the starch. In papermaking, the starch thus chemically modified is thoroughly treated and added to the wet end of the paper machine. By applying such a chemical modification process, a considerable cost is added to starch, and even if such a process is applied,
No starch having a surface charge sufficient to significantly improve the unfixed starch fixation over the unmodified starch fixation can be obtained.

Accordingly, there is a need for economical fillers for use in papermaking processes that increase particle retention without adversely affecting sizing. There is also a demand for a filler having an increased fixing rate, and further, a filler that imparts strength to a paper product into which the filler is incorporated. The present invention is directed to meeting these needs and provides additional associated advantages.

[0007] In embodiments one Summary of the Invention, the present invention provides a modified polysaccharide having an increased surface charge. The polysaccharide of the present invention is a polysaccharide modified to contain a cationic polymer. The modified starch formed in accordance with the present invention has a surface charge of about +5 mV to about +20 mV. The modified polysaccharide is advantageously incorporated into a papermaking furnish with increased fixability.

In another aspect of the invention, a paper product is provided that includes a modified polysaccharide having an increased surface charge. Paper products containing modified polysaccharides are stronger than paper products constructed in a similar manner without incorporating modified polysaccharides. In one embodiment, the paper product of the present invention comprises cellulosic fibers and modified polysaccharides. In other embodiments,
The paper product of the present invention further comprises, in addition to the cellulose fiber and the modified polysaccharide, a fixing aid that increases the fixing ratio of the modified polysaccharide to the fiber. The fixing aid may be a positively charged fixing aid or a negatively charged fixing aid.

In yet another aspect, the present invention provides a method for forming a modified polysaccharide having an increased surface charge, and the incorporation of the modified polysaccharide to increase strength and filler retention. And a method for forming an improved paper product.

Detailed Description of the Preferred Embodiments In one aspect, the present invention provides polysaccharides with increased surface charge.
The polysaccharide was modified to include a cationic additive that imparts a positive charge to the polysaccharide surface. As used herein, "polysaccharide" and "starch" are interchangeable terms, and "modified starch" and "modified polysaccharide" are used to increase the surface charge formed in accordance with the present invention. It represents a polysaccharide.

Suitable cationic additives are substances which are able to bind irreversibly and / or strongly to the starch and increase its surface charge when bound to the starch. Cationic additives include cationic organic polyelectrolytes and polymers. The cationic additive preferably comprises a cationic polymer such as a polyquaternary amine. In a preferred embodiment, the cationic additive is about 1,
It is a relatively low molecular weight, strongly positively charged polyquaternary amine having a molecular weight in the range of 000,000 g / mol to about 5,000,000 g / mol and about 3 milliequivalents of quaternary amine per gram. Such a polyquaternary amine is commercially available under the trade name Nalco 7527 from Nalco Chemical Co., Naperville, Illinois. The cationic additive is present on the starch in an amount of about 1 pound to about 15 pounds per ton of starch on a dry basis, preferably about 5 pounds per ton of starch.

Other cationic additives useful in forming the modified starches of the present invention include:
Cationic polyacrylamide, aluminum sulfate, chitosan, polyamine, polyamidoamine, polyethyleneimine, polyamide-epichlorohydrin (PAE),
Polyalkylene polyamine-epichlorohydrin (PAPAE), and amine polymers
-Epichlorohydrin (APE) etc.

The modified starch formed according to the present invention has a surface charge (as measured by zeta potential) in the range of about +1 mV to about +100 mV, preferably in the range of about +5 mV to about +20 mV. Starch from various sources can be modified to provide starch with increased surface charge. Corn, potatoes, tapioca, peas,
Suitable starch is obtained from wheat and wheat.

The modified starch of the present invention can be formed from a slurry obtained by mixing untreated starch and a cationic additive in water. In one embodiment, untreated starch is added to water at pH 10 to obtain a slurry with about 7% solids.
Starch swells in an alkaline solution to form a milky white paste. Although swelling occurs, the starch remains in individual particle form. However, at higher pH, gelation may occur as a result of denaturation (ie, chemical cooking). Gelation during the formation of modified starch must be avoided. Without intending to be bound by the theory below, I would like to propose the idea that the cationic additive diffuses into the surface of the swollen starch particles, resulting in surface charged particles. Adjusting the pH of the starch slurry treated with the cationic additive to near neutral pH traps the cationic additive within the starch particles. The addition of the cationic additive changes the appearance of the starch from a milky paste to granular sandy particles. Alternatively, in another embodiment, the modified starch can be formed by adding a cationic additive to the starch slurry at about pH 7. neutral
Although the degree of swelling at pH is less than that occurring at alkaline pH,
Sufficient to obtain modified starch with increased surface charge. In a preferred embodiment, the modified polysaccharide is a granular polysaccharide.

A representative starch particle formed in accordance with the present invention is shown schematically in FIG. Referring to FIG. 1, modified starch particles 10 include a cationic additive 12 attached to starch particles 14.

The preparation and properties of a representative modified starch with increased surface charge are described in Example 1. The measurement of the surface charge of a representative surface charge enhanced starch particle formed in accordance with the present invention is described in Example 2.

The modified starches of the present invention are advantageously incorporated into the papermaking furnish. As described below, the modified starch is well established by the pulp, which makes it an economical filler for paper products. Moreover, paper products incorporating the modified starch pulp have increased strength.

Modified starch has a greater degree of fixation in pulp than untreated starch.
Britt Jar experiments have shown that modified starch can be anchored by pulp to a comparable extent or better compared to traditional fillers, precipitated calcium carbonate (PCC). There is. For fine paper furnishes, about 60 to about 70% modified starch was generally fixed under conditions such that about 45% PCC was fixed.

The modified starch can be fully fixed by the pulp to give a pulp that results in a paper product with a high percentage of filler retention. Alternatively, in addition to the modified starch, other fixing aids can be added to the pulp to further increase the fixing rate of the modified starch. The fixing aid includes a fixing aid known in the paper manufacturing industry, and an anionic fixing aid and a cationic fixing aid as described below.

Anionic fixing aids or additives can be used to increase the fixing rate of the modified starch. Anionic fixing aids include anionic organic polyelectrolytes and polymers. The anionic fixing aid preferably comprises an anionic polymer such as anionic polyacrylamide (APAM). In a preferred embodiment, the anionic fixing aid is a relatively high molecular weight, somewhat negatively charged polyacrylamide. A preferred polyacrylamide is about 8,000,000 g /
It is a copolymer of acrylic acid (30 mol%) and acrylamide (70 mol%) having a molecular weight in the range of mol to about 15,000,000 g / mol. Such polyacrylamides are commercially available from Cytec Industries, Inc. of West Patterson, NJ (C
It is commercially available from ytec Industries Inc. under the product name of Accurac 171. Separately, anionic polyacrylamide is available from Northwest Specialty Chemica in Vancouver, Washington.
It is marketed under the product name of Nugen 24 from ls). The anionic fixing aid is present in the fibrous pulp in an amount of about 0.1 pounds to about 3.0 pounds per ton of fiber, preferably about 0.5 pounds per ton of fiber.

Other suitable anionic fixing aids include high molecular weight anionic flocculants. As described in Example 3, a typical anionic fixative (e.g. APAM) is preferably added to the pulp at the wet end of the paper machine, prior to adding the modified starch, simultaneously with the modified starch, or modified starch. The pulp can be added at any time after the addition of. As shown in Table 9, the highest fixation (72 wt%) was achieved when APAM was added to the pulp followed by modified starch. The second highest retention (58 wt%) when modified starch was added to the pulp and then APAM
) Has been achieved. Both of these conditions resulted in higher filler retention than the typical alkaline fine paper system (45 wt%).

Still other additives can also increase the fixing rate of modified starch with pulp. For example, cationic fixing aids and cationic additives can increase the pulp fixing rate of modified starch. The cationic fixative preferably comprises a cationic polymer such as, for example, cationic polyacrylamide (CPAM), which has a relatively high molecular weight and is somewhat positively charged. A preferred polyacrylamide has a molecular weight in the range of about 8,000,000 g / mol to about 15,000,000 g / mol and is a copolymer of acrylamide (90 mol%) and a quaternary amine monomer (10 mol%). Such a polyacrylamide is commercially available from Cytec Industries, Inc. of West Patterson, NJ under the product name Acurac 182RS. The cationic fixing aid is present in the fibrous pulp in an amount of about 0.1 pounds to about 12 pounds per ton of fiber, preferably about 0.4 pounds to about 6 pounds per ton of fiber. A combination of anionic and cationic fixing aids can be used with the modified starch to increase pulp fixability.

Other suitable cationic fixing aids include high molecular weight cationic flocculants (eg, commercially available from Nalco Chemical Co. of Naperville, Ill. Under the trade names Nalco 7530 and Nalco 7520). Cationic polyacrylamide].

Pulps containing strongly fixed modified starch can be formed into paper products which are characterized by high filler retention and higher strength. Paper products that benefit from incorporating modified starch include fine paper, newsprint, exposed paperboard, corrugated fiberboard, medium board, and corrugated cardboard (OCC) that uses conventional corrugated broth. .

Paper products containing modified starch and optionally one or more of the above fixing aids are:
The modified starch, and optionally the fixing aid, can be formed by adding it to the pulp furnish at the wet end of the paper machine. Depending on the properties desired for the paper product, the modified starch will contain from about 0.5% by weight to about
It can be added to the pulp furnish in an amount of 20% by weight (preferably about 3% to about 10% by weight).

The rheological properties of pulp furnishes, including their ease of dewatering from the furnish, are important factors in high speed papermaking processes and papermaking machines. One advantage of the present invention is that adding modified starch to pulp furnish does not adversely affect the flow properties of the furnish, despite the high modified starch fixation of the furnish. is there. Furthermore, treating pulp with anionic fixing aids according to the invention does not adversely affect the furnish by the addition of modified starch. Gum-like precipitates even when modified starch is added to the wet furnish of pulp furnish treated with anionic fixing aid
(Which adversely affects the quality of the pulp furnish and limits its applicability to high speed papermaking) is not formed. Similarly, adding a cationic fixing aid to a pulp furnish containing an anionic fixing aid and / or modified starch does not adversely affect the pulp furnish.

The formation and properties of a representative paper product (OCC) containing modified starch is described in Example 4. The strength properties of representative OCC products are summarized in Table 11. From these results, the Mullen burst strength for OCC products containing 3 wt% modified starch is
It can be seen that the increase is about 20% as compared to the OCC product which is similarly configured without incorporating the modified starch. Short span compression STFI,
An increase in tensile strength and stretch was also observed. This OCC product has a short-span compression STFI of about 5% compared to an OCC product that was similarly configured without modified starch.
%, Tensile strength increased about 9%, and stretch increased about 16%.

Further, (a) the amount of cationic additive used to produce the modified starch;
Representative OCC products were made by varying b) the amount of modified starch added to the pulp furnish; and (c) the type and amount of fixing aids added to the pulp furnish. Various representative O
The results of starch retention (%) for CC products are summarized in Table 12. From the results shown in Table 12, it can be seen that the modified starch is sufficiently fixed by the pulp, and that the fixing rate of the modified starch can be increased by using the fixing aid. The anionic fixing aid provided a greater degree of fixing rate improvement than the cationic fixing aid.

[0029] In manufacturing the embodiment of Example Example 1 Typical surface charge increased starch, describes the preparation and physical properties of a typical starch having an increased surface charge. A representative starch containing a cationic polymer and a polyquaternary amine (PQA) was prepared as described in set 1. A representative starch containing a polyquaternary amine, and further a fixing aid (APAM) was prepared as described in Set 2.

Set 1 cationic potato starch [Accosize 80, commercially available from Cytec Industries, Inc., West Patterson, NJ],
Steamed with 3.85% solids in a laboratory cooker (4
4g, 100 ml deionized water in 86% solids). A 0.1% solution of a representative cationic polymer (low molecular weight, highly positively charged polyquaternary amine (PQA), commercially available from Nalco Chemical Company, Naperville, Ill. Under the name Nalco 7527) is used. %
Diluted to active (0.1% actives) (1.43 g diluted to 500 ml).

5.71 g of tapioca native starch in each of beakers 1, 2 and 3
(5.0 g OD) was diluted to 50 ml with pH 10 buffer solution and left for 30 minutes. In beaker 2, add 0.95% treated cationic potato starch (1.25 g of 3.78% solution),
Mix well. In Beaker 3, 5 lb / ton Nalco 7527 was added (12.5 g of 0.1% solution) and mixed well. Remove all three of these beakers by
Equilibrate for 0 minutes.

All beakers were adjusted to pH 7 with 1N sulfuric acid and observed using a microscope. 1.0g
OD pulp (hardwood bleached kraft pulp, HWBK, aspen, disintegration, commercially available from Weyerhaeuser Co.) at 0.5% consistency 10 wt.
% (OD pulp standard) 3 types of starch samples (about 7% solid 1 ml starch)
Were added and mixed. These starch samples were observed under a microscope.

Set 2 Cationic potato starch (Akosize 80) was treated with 4.5% solids in a laboratory cooker (69, 86% solids in 1340 ml deionized water).
. A 0.1% solution of Narco 7527 was diluted 0.1% active (1.43 g diluted to 500 ml). A 0.01% active dilution of a 0.1% solution of a representative fixing aid (polyacrylamide with a high molecular weight and some negative charge, APAM, available from Cytec Industries, Inc., West Patterson, NJ under the name Acurac 171). (1.43 g to 5
Dilute to 00 ml, then 10-fold).

In each of beakers 1, 2 and 3, 5.0 g of tapioca unmodified starch (
4.4 g of OD) was diluted to 50 ml with pH 10 buffer solution and equilibrated for 15 minutes. In beaker 2, add 1.3% cationic potato starch (Akosize 80) (4.5% solution 1.25 g
), Mixed well. In Beaker 3, 5.7 lb / ton PQA (Nalco 7527) was added (12.5 g of 0.1% solution) and mixed well. After the addition treatment, these solutions were equilibrated for 30 minutes. All three beakers were adjusted to pH 7 with 1N sulfuric acid and left for 1 hour.

Pulp Treatment Hardwood bleached kraft pulp (HWBK) is disintegrated and 0.25 with deionized water.
Diluted to a% consistency. To each of the 6 beakers was added 0.5 g pulp at 0.25% consistency. Three pulp samples were pretreated with APAM by adding 0.5 lb / ton (1.25 g of 0.001% solution) APAM. The pulp was mixed well and the starch solution was added to the pulp sample. To a non-pretreated pulp sample was added 0.5 lb / ton APAM (1.25 g of 0.001% solution) and mixed. All six conditions were analyzed qualitatively using a microscope.

The first experiment was designed to quantitatively compare unmodified tapioca starch with the addition of treated cationic potato starch or a cationic polymer (polyquaternary amine (PQA)). It was done. A microscope was used to observe any physical changes and reactions with other starch particles or fibers. The results of observation with a microscope are shown in Table 1.

[0037]

[Table 1]

After adding PQA and lowering the pH, a considerable difference in the behavior of the starch slurry was observed. Starch granules appear to be highly dispersed. Furthermore, some interaction was observed between the modified starch and the fiber before and after pH adjustment. The addition of the treated starch and PQA caused the starch particles to cause some interaction when added to the fiber.

The effect of post-treatment or pre-treatment of the fibers with an anionic polymer (APAM) on the reaction of the modified starch solution was also investigated. In one case, APAM was added to the fiber before adding the starch slurry, and in another case APAM was added after adding the starch to the fiber. The observation results are shown in Table 2.

[0040]

[Table 2]

Treatment with APAM had little effect on the appearance of fibers treated with cationic starch or PQA modified starch.

Example 2 Measurement of Surface Charge of Representative Starch Particles with Increased Surface Charge In this example, measurement of surface charge of a typical starch particle with increased surface charge will be described. Surface charge is determined by measuring the zeta potential.

Sets 1 and 2: Control Starch and Modified Starch Unmodified tapioca starch was used for each test. 50 ml of pH 10 buffer was added to each starch sample (5.0 g), and this solution was allowed to stand for 1 hour. After standing for 1 hour, 5 pounds / ton (active standard (act
ive basis)] PQA (Nalco 7527) was added to the starch and mixed well to obtain a "denatured sample". No polymer was added to the control sample. The sample was left for an additional hour and then adjusted to pH 7 with 1N sulfuric acid. 1 more sample
It was left to stand for an hour before analysis.

Set 3: 5.0 g of denatured starch with varying pH
Denatured samples were made by adding in 50 ml of pH 10 buffer (above), allowing to stand for 1 hour, and then adding 5 lb / ton PQA (Nalco 7527). After 1 hour, pH with 1N sulfuric acid
It was adjusted to 7 and left for 1 hour at the end. As-received 5.0g tapioca starch
A second sample was made by adding pH 10 buffer and left. After the indicated time, 5 lbs / ton PQA (Nalco 7527) was added and left for another 2 hours without further pH adjustment. A third sample was prepared as described above, except pH 7 buffer was added to the starch without further pH adjustment.

Zeta Potential Measurements Using a Delsa 440 [Coulter Electronics, Inc., Hialeah, Fla.] Frequency range of ± 500 Hz and equal to 1/2 of the conductivity value of the sample. Performed at current, the zeta potential for all samples was measured. Two cell heights (cell
height) (16 and 84). By adding PQA, the sample remained very well dispersed and allowed to stand for 1 hour before analysis.

Table 3 shows the zeta potential measurement results from the samples of set 1. Charge is cell height
Averages of measurements at 16 and 18 at 8.6 °, 17.1 °, 25.6 °, and 34.2 °. The control standard (undenatured sample) was measured three times and the denatured sample was measured twice. These results show that the addition of the cationic polyacrylamide resulted in a modified sample with a significantly increased surface charge compared to the control.

[0047]

[Table 3]

Table 4 shows the zeta potential measurement results from the set 2 samples. Since settling in the zeta potential cell can shift the stationary plane, experiments were performed on test samples of various consistency to determine the effect on charge analysis. Examined. The analysis was performed after changing the consistency by changing the sedimentation time of the starch slurry. The same samples were made for the first set, incorporating control and denatured samples. In addition, the denatured sample was washed with deionized water to see if the charge was present on the surface of the particles, or simply weakly associated with the surface.

[0049]

[Table 4]

From these results, it can be seen that the sedimentation time has an influence on the measurement of zeta potential. These results further indicate that the charge is on the surface of the particle and is not simply weakly bound to the surface, and washing the starch particles has little effect on zeta potential measurements. It is shown that.

To examine the effect of pH on the formation of modified starch and the charge on the particles as a whole, three samples (Set 3 samples prepared as described above) were compared. The results obtained are shown in Table 5.

[0052]

[Table 5]

The modified samples all had similar cationic charges. Adjusting the pH does not appear to have a significant effect on the surface charge modification process.

EXAMPLE 3 Fixing of Representative Starch-enhancing Starch with Pulp In this example, fixing of representative starch with increased surface charge with pulp is described. To determine if the modified starch could be retained under high shear conditions, a brit jar was used to study fixability.

Pulp Preparation Prince Albert, using the following conditions:
Hardwood was purified to 400 mL CSF by Escher Wyss Conical Refiner (Bird Escher Wis, Manfield, MA):
3.0% consistency, 1.0Ws / m specific edge load, 1250
rpm, cutting length of 0.583km / s, and bar angle of 60 °. Prince Albert softwood was refined to 600 mL CSF by Escher Wis using the same conditions except that the specific edge load was 3.0 Ws / m. Power specifi
ic energy) is 48.6kW-h / t, and the power specific energy for softwood is 1.75kW-h / t.
Met. A pulp blend of 60% hardwood and 40% softwood was made. A 200 mesh screen box was used to remove fines. The final freeness value of the fines-free pulp mixture was 695 mL at 2.2% consistency.

Brit Jar Conditions A brit jar with a 100 mesh conical mesh screen was used in the determination of fixation. The pulp was added into a brit jar with stopper and mixed with starch at various speeds. After the time for sampling had elapsed, the stopper was opened and the filtrate was collected in a tared aluminum pan (about 100 ml). The pan was immediately weighed according to the same 4 point balance used for the tare. The bread was placed in an oven at 105 ° C until the next day. The dried sample was placed in a desiccator and then the pan was weighed again. The consistency of the unfixed slurry was calculated from Equation 1.

[0057]

[Equation 1]

[0058]   The fixing rate with the pulp slurry was calculated using Equation 2.

[0059]

[Equation 2]

A basic study was performed on a typical alkaline fine paper furnish to determine the appropriate degree of shear or mixing rate. The fixability of starch formed according to the present invention was compared to that of precipitated calcium carbonate.

Chemicals The pulp prepared above was diluted with deionized water to a consistency of 0.65%. Precipitated calcium carbonate (PCC) was obtained from Specialty Minerals, Inc. of Bethlehem, PA (31.6% solids). A solution of highly charged high molecular weight anionic polyacrylamide (APAM, Acurac 171) has a
It was made by diluting 3 g of APAM to 500 ml with deionized water. This solution was mixed for 15 seconds with a Braun hand blender to obtain a 0.1% APAM solution, and then 50 ml of the 0.1% solution was diluted 10 times to 500 ml with deionized water to obtain a 0.01% solution. 69
By mixing .6g starch (86% solids) with 1340ml deionized water,
A 4.5% solids solution of cationic potato starch (Akosize 80) was prepared.

Brit Jar Procedure To a Brit Jar was added pulp (2.5 g, 385 g at 0.65% consistency). Table 6 shows the chemical additions and amounts made to make the pulp samples and the mixing time after each addition.

[0063]

[Table 6]

The above conditions were carried out at three different mixing speeds (500, 1000, and 1500 rpm), and the end point was the time when the filler was actually fixed. Typical filler retention rates on fine paper machines are 50-55%. Table 7 shows the results depending on the mixing speed.

[0065]

[Table 7]

Referring to Table 7, the 500 rpm data set resulted in effective retention,
It shows that fixing is insufficient under the condition of higher mixing speed.

Fixing Modified Starches The fixings of the modified starches of the present invention were compared for a typical fine paper furnish containing PCC. APAM solution and cationic starch solution were prepared as described above. In addition, 1.43 g of stock solution was diluted to 500 ml with deionized water to obtain PQA.
A solution (Narco 7527) was made. This PQA solution was 0.1% actives and was mixed for 15 seconds on a Brown hand blender. The PCC is as described above. The pulp was diluted with deionized water to a 0.42% consistency.

Modified starch was prepared by diluting 5.0 g (12.5% solids) of unmodified tapioca starch to 50 ml with pH 10 buffer. The starch was mixed well and left for 1 hour. 12.5 ml of 0.1% PQA (Nalco 7527) was added and mixed well. The solution was left for another hour. The pH was adjusted to 7 with 1 N sulfuric acid (about 2.7 ml). The final consistency of the starch solution was 6.7%.

A control starch was made by diluting 5.0 g (12.5% solids) of native tapioca starch to 50 ml with pH 10 buffer. The starch was mixed well and left for 1 hour. 12.5 ml deionized water was added and mixed well. The solution was left for another hour. The pH was adjusted to 7 with 1 N sulfuric acid (about 2.5 ml). The final consistency of the starch solution was 6.7%.

Brit Jar Procedure For each Brit Jar experiment, 2.5 g of pulp (595 g at 0.42% consistency) was added and mixed at 500 rpm. 6.5 g of 6.7% starch was added (17.4%) to the control and modified starch. 6.25 ml for APAM
Of 0.01% solution (0.5 lb / ton) and for cationic potato starch, 0.5 g of 4.5% solids (17 lb / ton) was added. For PCC, 1.6g 31.6%
The solution was added (20%). The conditions are listed in Table 8. Experiments were conducted three times for each condition and the entire experiment was performed randomly (except for the alkaline fine paper furnish which completed the first three experiments).

[0071]

[Table 8]

[0072]   The fixing rate of the filler (modified starch or PCC) is shown in Table 9.

[0073]

[Table 9]

The highest fixation was achieved when APAM was added to the pulp followed by modified starch. The next highest retention is the addition of modified starch to the pulp, followed by APAM
Was obtained when. Both of these conditions showed higher filler retention than typical alkaline fine paper systems.

Effect of Treatment pH on Fixation of Modified Starch The pulp with the highest starch retention was obtained using pulp fibers pretreated with APAM. To investigate the effect of pH on the fixation of modified starch by pulp, pulp was treated with modified starch at three different pH conditions. Pulp, APAM, and PQA were made as described above. The original pulp mixture was diluted with deionized water to 0.41% consistency. 605g of 0.41% solution was used for each condition to add 2.5g of OD pulp. Three starch solutions were made as follows.

Modified Starch pH 10-7 5 g (12.5% solids) of unmodified tapioca starch was added to pH 10
It was diluted to 50 ml with the above buffer. The starch was mixed well and left for 1 hour. 12.5 ml
0.1% Nalco 7527 was added and mixed thoroughly. The solution was left for another hour. 1N
The pH was adjusted to 7 with sulfuric acid (about 2.7 ml). The solution was allowed to equilibrate for an additional 1 hour. The final consistency of the starch solution was 6.7%.

Modified Starch pH 10-10 5 g (12.5% solids) of unmodified tapioca starch was added to pH 10
It was diluted to 50 ml with the above buffer. The starch was mixed well and left for 1 hour. 12.5 ml
0.1% Nalco 7527 was added and mixed thoroughly. The solution was left for a further 2 hours. The final consistency of the starch solution was 6.7%.

Modified Starch pH7-7 5 g (12.5% solids) of unmodified tapioca starch was diluted to 50 ml with pH 7 buffer. The starch was mixed well and left for 1 hour. 12.5 ml 0
.1% Nalco 7527 was added and mixed well. The solution was left for a further 2 hours. The final consistency of the starch solution was 6.7%.

Brit Jar Procedure Add APAM to the pulp in the Brit Jar and mix for 30 seconds,
Then the starch slurry was added. 0.5 lb / ton APAM (6.25 m
l of 0.01% solution) and 20% starch (7.4 ml of 6.74% solution) were added. The experiment was performed randomly and was performed three times for each condition. The results of pH changes are shown in Table 10.

[0080]

[Table 10]

All of the conditions tested showed high fixation rates, with the pH7 / pH7 conditions showing somewhat higher fixation rates than the pH10 / pH10 conditions.

Example 4 Formation and Properties of Representative OCC Containing Starch-Enhanced Starch This example describes the formation and properties of a conventional corrugated board (OCC) containing modified starch. The properties of representative OCC articles were investigated and compared to OCC articles that did not contain modified starch.

OCC articles were formed from fibrous furnish containing 100% OCC. Modified starch was made by adding 5 lbs of PQA (Nalco 7527) per ton of starch, as described above. The pulp furnish was treated with 0.5 lbs of APAM (Acurac 171) per ton of fiber, 3% by weight of modified starch was added based on the total weight of the fiber, and then 5 lbs of CPAM (acure Rack 182RS) was added. After depositing the pulp furnish containing the modified starch on a support having pores, the deposited pulp was dehydrated and then dried to obtain an OCC article.

The properties of the OCC article prepared as described above are shown in Table 11. In the table, Sample 1 represents an OCC article formed without the incorporation of modified starch and Sample 2
Represents an OCC article containing 3% by weight modified starch, based on the total weight of the fiber. In the table, SSC STFI and TEA represent short span compression STFI and tensile energy absorption, respectively.

[0085]

[Table 11]

Referring to Table 11, the Mullen burst strengths for OCC article samples 1 and 2 are:
It can be seen that there is about a 20% increase over the similarly constructed OCC article without the incorporation of modified starch. Short-span compression STFI, tensile strength, and increased stretch were also observed. OCC articles containing modified starch have a short-span compression STFI of about 5% and a tensile strength of about 9% as compared to OCC articles of similar construction without the incorporation of modified starch.
, And the stretch was increased by about 16%.

The weight percentages of starch retained in a representative OCC article are comparable to each other and to OCC articles containing unmodified starch. The results are shown in Tables 12-15. Several representative examples were used, varying the amount of cationic additive used to make the modified starch, the amount of modified starch added to the pulp furnish, and the type and amount of fixing aid added to the pulp furnish. Formed an OCC article. The results of starch retention for various representative OCC articles are shown in Table 12. In these articles, the cationic additive used to form the modified starch was PQA (Nalco 7527), the anionic fixing aid was APAM (Acurac 171), and the cationic fixing aid was CPAM ( It was Acurac 182). The following terms are used in Table 12: Modified starch refers to starch modified with 5 pounds of PQA (Nalco 7527) per tonne of starch; variable PQA is pulp furnish. An OCC article made by pre-treating 1 part of fiber with 0.5 lbs of APAM (Acurac 171) and then with modified starch made from starch and various amounts of PQA (Nalco 7527). A, B, C, and D represent OCC articles containing modified starch made from 1, 2, 3, 5, and 7 pounds of PQA (Nalco 7527) per tonne of starch. Variable APAM pretreats pulp furnish with varying amounts of APAM (Acurac 171) and then with modified starch made from starch and 5 pounds PQA per ton of starch (Narco 7527). O made by Represents CC articles; E, F, and G represent OCC articles where pulp furnish was pretreated with 0.25, 0.50, and 0.75 pounds APAM (Acurac 171) per tonne of fiber. APAM / PQA / APAM is pretreated with APAM (Acurac 171) with a pulp furnish of 0.25 pounds, followed by starch, 5 pounds PQA per ton of starch (Nalco 7527)
, And OCC articles treated with modified starch made from 0.25 pounds of APAM (Acurac 171) per tonne of fiber; APAM / PQA / CPAM is an APAM with 0.25 pounds of pulp furnish. Rack 171) and then starch and 5 pounds PQA per ton of starch (Narco 7527)
Treated with modified starch made from, then 2.0 lbs of CPA per ton of fiber
Represents an OCC article treated with M (Acurac 182); Variable CPAM treats pulp furnish with various amounts of CPAM (Acurac 182), then starch and 5 pounds per tonne of starch. Represents an OCC article made by treatment with a modified starch made from PQA (Nalco 7527); H, I, and J represent pulp furnishes of 1.0, 2.0, and 3.0 per ton of fiber.
FIG. 6 represents an OCC article treated with pound CPAM (Acurac 182).

[0088]

[Table 12]

The results in Table 12 show that the modified starch is strongly retained by the pulp and that the fixing rate of the modified starch can be increased by using fixing aids. Anionic fixing aids have a greater degree of fixing rate increase than cationic fixing aids.

The weight percent of modified starch retained in a typical OCC article was determined to be 0.5 per ton of fiber.
It was investigated as a function of the amount of cationic additive (PQA, Nalco 7527) per ton of starch, pretreated with pounds of anionic fixing aid (APAM, Acurac 171). The results obtained are shown in Table 13.

[0091]

[Table 13]

The results in Table 13 show that fairly high retention rates were achieved with 1-7 pounds of PQA per ton of starch, with near optimal retention using about 5 pounds of PQA per ton of starch. It shows that it can be obtained.

Modified starch retained in a typical OCC article (5 pounds per ton starch)
The weight percent of PQA) was investigated as a function of pretreatment with various amounts of anionic fixative (APAM, Acurac 171). The results obtained are shown in Table 14.

[0094]

[Table 14]

The results in Table 14 show that the best fixing rates were achieved when pretreated with 0.50 pounds of anionic fixing aid per ton of fiber. Modified starch retained in a typical OCC article (5 lbs / ton starch)
The weight percent of PQA) was investigated as a function of treatment with various amounts of cationic fixative (CPAM, Acurac 182). The results obtained are shown in Table 15.

[0096]

[Table 15]

The results in Table 15 show that a fairly high retention rate was achieved using 1-3 pounds of CPAM per ton of starch. While the preferred embodiment of the invention has been described, it will be understood that various changes may be made without departing from the spirit and scope of the invention.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an exemplary modified polysaccharide formed in accordance with the present invention.

─────────────────────────────────────────────────── ─── Continued front page    (81) Designated countries EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, I T, LU, MC, NL, PT, SE), OA (BF, BJ , CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, K E, LS, MW, MZ, SD, SL, SZ, TZ, UG , ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AE, AG, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, BZ, C A, CH, CN, CR, CU, CZ, DE, DK, DM , DZ, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, K E, KG, KP, KR, KZ, LC, LK, LR, LS , LT, LU, LV, MA, MD, MG, MK, MN, MW, MX, MZ, NO, NZ, PL, PT, RO, R U, SD, SE, SG, SI, SK, SL, TJ, TM , TR, TT, TZ, UA, UG, UZ, VN, YU, ZA, ZW F-term (reference) 4L055 AG44 AG48 AH09 EA30 EA32                       EA35 FA10 FA23

Claims (55)

[Claims] 1. A composition comprising polysaccharide particles and a cationic additive, wherein said cationic additive is attached to said polysaccharide particles to provide polysaccharide particles having a positive surface charge. The composition. 2. The cationic additive comprises a cationic polymer.
The composition according to 1. 3. The cationic polymer comprises a polyquaternary amine.
The composition according to 2. 4. The polyquaternary amine is from about 1,000,000 g / mol to about 5,000,000 g / mol.
The composition of claim 3 having a molecular weight in the molar range. 5. The composition of claim 3, wherein the polyquaternary amine has about 3 milliequivalents of quaternary amine per gram. 6. The cationic additive is from about 1 pound to about 1 ton of polysaccharide.
The composition of claim 1, wherein the composition is present in the composition in an amount of 15 pounds. 7. The composition of claim 1, wherein the surface charge ranges from about +1 mV to about +100 mV. 8. The polysaccharide is selected from the group consisting of corn starch, potato starch, tapioca starch, pea starch, and wheat starch.
The composition of claim 1. 9. A pulp furnish containing polysaccharide particles having a positive surface charge, wherein the polysaccharide particles having a positive surface charge include a cationic additive attached to the polysaccharide particles. The pulp furnish. 10. The pulp furnish of claim 9, wherein the cationic additive comprises a cationic polymer. 11. The pulp furnish of claim 10, wherein the cationic polymer comprises a polyquaternary amine. 12. The pulp furnish of claim 9, wherein the polysaccharide particles have a surface charge in the range of about +1 mV to about +100 mV. 13. The pulp furnish according to claim 9, further comprising an anionic fixing aid. 14. The pulp furnish of claim 9, further comprising a cationic fixing aid. 15. The pulp furnish of claim 13 further comprising a cationic fixing aid. 16. The pulp furnish of claim 13, wherein the anionic fixing aid comprises anionic polyacrylamide. 17. The pulp furnish of claim 16, wherein the anionic polyacrylamide comprises a copolymer of acrylic acid and acrylamide. 18. The pulp furnish of claim 17, wherein the copolymer comprises about 30 mol% acrylic acid and about 70 mol% acrylamide. 19. The pulp furnish of claim 17, wherein the copolymer has a molecular weight in the range of about 8,000,000 g / mol to about 15,000,000 g / mol. 20. The pulp furnish of claim 13, wherein the anionic fixing aid is present in the pulp furnish in an amount of about 0.1 pounds to about 3.0 pounds per ton of fiber. 21. The pulp furnish according to claim 14, wherein the cationic fixing aid comprises a cationic polyacrylamide. 22. The pulp furnish of claim 21, wherein the cationic polyacrylamide comprises a copolymer of acrylamide and a quaternary amine monomer. 23. The copolymer comprises about 90 mole% acrylamide and about 10 mole%.
23. The pulp furnish according to claim 22, comprising the quaternary amine monomer of. 24. The pulp furnish of claim 22, wherein the copolymer has a molecular weight in the range of about 8,000,000 g / mol to about 15,000,000 g / mol. 25. The pulp furnish of claim 14, wherein the cationic fixing aid is present in the pulp furnish in an amount of about 0.1 pounds to about 3.0 pounds per ton of fiber. 26. A paper product comprising polysaccharide particles having a positive surface charge, the paper product comprising:
The paper product, wherein the polysaccharide particles having a positive surface charge include a cationic additive attached to the polysaccharide particles. 27. The paper product of claim 26, wherein the cationic additive comprises a cationic polymer. 28. The paper product of claim 27, wherein the cationic polymer comprises a polyquaternary amine. 29. The paper product of claim 26, wherein the polysaccharide particles have a surface charge in the range of about +1 mV to about +100 mV. 30. The paper product of claim 26, further comprising an anionic fixing aid. 31. The paper product of claim 26, further comprising a cationic fixing aid. 32. The paper product of claim 30, further comprising a cationic fixing aid. 33. The paper product of claim 30, wherein the anionic fixing aid comprises anionic polyacrylamide. 34. The paper product of claim 31, wherein the cationic fixing aid comprises cationic polyacrylamide. 35. The paper product of claim 26, wherein the paper product is selected from the group consisting of fine paper, newsprint, exposed paperboard, corrugated board, medium board, and conventional corrugated board. 36. A step of adding a polysaccharide particle having a positive surface charge to a first pulp furnish to obtain a second pulp furnish, wherein the polysaccharide particle having a positive surface charge is said A cationic additive attached to the polysaccharide particles; a step of depositing the second pulp furnish on a support having small pores to obtain a wet web; and dehydrating and drying the wet web to paper. Obtaining a product; a method for forming a paper product. 37. The method of claim 36, wherein the cationic additive comprises a cationic polymer. 38. The method of claim 37, wherein the cationic polymer comprises a polyquaternary amine. 39. The method of claim 36, wherein the starch particles have a surface charge in the range of about +1 mV to about +100 mV. 40. The method of claim 36, further comprising adding an anionic fixing aid to the first pulp furnish. 41. The method of claim 36, further comprising adding a cationic fixing aid to the first pulp furnish. 42. The method of claim 40, further comprising adding a cationic fixing aid to the first pulp furnish. 43. The method of claim 40, wherein the anionic fixing aid comprises anionic polyacrylamide. 44. The method of claim 41, wherein the cationic fixing aid comprises cationic polyacrylamide. 45. The method of claim 36, wherein the paper product is selected from the group consisting of fine paper, newsprint, exposed paperboard, corrugated board, medium board, and conventional corrugated board. 46. A step of adding a polysaccharide particle having a positive surface charge to a first pulp furnish to obtain a second pulp furnish, wherein the polysaccharide particle having a positive surface charge is A cationic additive attached to the polysaccharide particles; a step of depositing the second pulp furnish on a support having small pores to obtain a wet web; and dehydrating and drying the wet web, Obtaining a paper product having a higher strength than paper constructed in a similar manner without incorporating polysaccharide particles having a positive surface charge; and increasing the strength of the paper product. 47. The method of claim 46, wherein the cationic additive comprises a cationic polymer. 48. The method of claim 47, wherein the cationic polymer comprises a polyquaternary amine. 49. The method of claim 47, wherein the polysaccharide particles have a surface charge in the range of about +1 mV to about +100 mV. 50. The method of claim 47, further comprising adding an anionic fixing aid to the first pulp furnish. 51. The method of claim 47, further comprising adding a cationic fixing aid to the first pulp furnish. 52. The method of claim 50, further comprising adding a cationic fixing aid to the first pulp furnish. 53. The method of claim 50, wherein the anionic fixing aid comprises anionic polyacrylamide. 54. The method of claim 52, wherein the cationic fixing aid comprises cationic polyacrylamide. 55. The method of claim 46, wherein the paper product is selected from the group consisting of fine paper, newsprint, exposed paperboard, corrugated board, medium board, and conventional corrugated board.