MX2008009158A - Papermaking processes using coagulants and optical brighteners - Google Patents

Abstract

A method of making paper or paperboard is described, which includes introducing at least one charged starch, preferably having a degree of substitution greater than 0.045, and at least one optical brightening agent to a papermaking pulp and then forming the pulp into paper or paperboard. The present invention further describes methods of improving optical brightener performance.

Description

PAPER MANUFACTURING PROCESSES THAT USE COAGULANTS AND OPTICAL POLISHERS BACKGROUND OF THE INVENTION The present invention relates to paper manufacturing processes and products manufactured from these processes. More particularly, the present invention relates to the treatment of paper pulp with at least one ged starch, such as cationically ged starches and one or more optical brighteners. Optical brighteners or optical brightening agents (OBAs) and Fluorescent Bleaching Agents (FWAs) are typically used in certain papermaking processes to increase or improve the brightness of paper or paperboard and / or to increase or improve fluorescence intensity of the paper. The OBA / FWA products can be added in the size press with other additives. Other certain OBA / FWAs can be added in the wet part of the papermaking process. The present invention relates, in part, to the increased retention and / or efficiency of the OBAs / FWAs, whether present from the addition of the wet part of the OBA or the OBA present in the cutout (contains recycled paper), as well as not mitigate or overshadow the impact of the OBA from any source, on the paper machine and on the final sheet of paper. Many consumers prefer paper with a High brilliance, and the brilliance of paper is typically promoted as an important parameter to consumers of paper products. In order to achieve brilliance in the paper, especially papers having a high brightness, such as above 80%, one or more optical brighteners or optical brightening agents are added during the papermaking process. These optical brighteners can be very expensive and raise the full cost of the paper product. This can be seen by any consumer who buys paper. For example, there may be a significant cost difference between a paper that has a brightness of 80% compared to a brightness of 96%. Typically, the optical brighteners are added to the wet part process, or to the size press or to both the wet part and the size press within the papermaking process. In typical papermaking processes, coagulants and flocculants are additionally used during the papermaking process in order to obtain desirable pulp acteristics, paper acteristics, and retention and functionality of the paper machine. Typically, the coagulants neutralize the system ge and help the pulp fibers, fines, fillers and functional additives to coagulate electrostatically together by retaining them in the sheet and form a paper product more uniform. Traditional coagulants include polyaminoamido glycol, polyethylene imine, polyamine, polyisocyanate, alum and polyaluminium chloride. While coagulants are necessary to produce paper that have adequate acteristics, many of these coagulants, unfortunately, affect in a negative way, previously added optical brighteners. In particular, traditional coagulants can dull the effect of the optical brighteners, thereby reducing the ISO brightness of the paper and / or reducing the fluorescence intensity of the paper. As a result, papermakers have typically added more optical brighteners, particularly in the wet part of the paper machine system, to compensate for this overshadowing that occurs with the use of traditional coagulants. The coagulants are also typically added in the wet part stage of the papermaking process either to a coarse raw material or to a thin raw material feed location. Thus, there is a need for a new papermaking process that avoids this opaque effect caused by traditional coagulants. In addition, there is a need to develop a process that will allow the use of optical brighteners without the need to provide an additional amount of optical brighteners to compensate the use of coagulants during the papermaking process. A feature of the present invention is to provide a method for making paper or paperboard which preferably does not obscure the effects of optical brightening agents. A further feature of the present invention is to provide a method that allows for the reduction in the amount of optical brightening agents and still achieves satisfactory brightness and / or fluorescence intensity of the paper in the paper or paperboard. Further features and advantages of the present invention will be set forth in part in the description that follows, and in part will be apparent from the description, or may be learned by the practice of the present invention. The objects and other advantages of the present invention will be understood and achieved by means of the elements and combinations particularly indicated in the description and the appended claims. In order to achieve these and other advantages, and in accordance with the purposes of the present invention, as they are incorporated and widely described herein, the present invention relates to a method for manufacturing paper or paperboard which involves introducing at least one starch ionically charged (preferably with a degree of substitution above 0.045) and at least one optical brightening agent to a paper pulp to form a treated pulp. The treated pulp can then be formed into a paper or cardboard product. The ionically charged starch and the optical brightening agent can be added in any order. For example, the starch can be added to the thin raw material and the optical brightening agent can be added to the coarse raw material, the OBA can be added to the thin raw material, to the coarse raw material, or both, and / or the starch can be added to the thin raw material, the coarse raw material, or both. The present invention further relates to a method for improving optical brightening performance by using at least one ionically charged starch (preferably with a degree of substitution above 0.045) and at least one optical brightening agent and adding these components to a pulp. paper to form a treated pulp then form the treated pulp into a paper or cardboard. The present invention further relates to paper or paperboard that can be obtained by one or more of the methods of the present invention. It will be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide an additional explanation of this invention, as claimed. The accompanying drawings, which are incorporated within and constitute a part of this application, illustrate various embodiments of the present invention and together with the description, serve to explain at least one or more principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS Figs. 1 and 2 are flow diagrams showing a papermaking process according to one or more embodiments of the present invention. Fig. 3 is a bar graph comparing several test sheet samples with optical brightening agents with or without cationic starches and measuring the resulting ISO brightness. Fig. 4 is a photograph showing the fluorescence image of several samples of test sheets containing an optical brightening agent with or without a cationic starch. DETAILED DESCRIPTION OF THE PRESENT INVENTION The present invention provides methods for making paper or paperboard that use one or more optical brightening agents during the papermaking or papermaking process. For purposes of the present invention, paper pulp will refer to pulp that can be made into paper or cardboard products.

In the present invention, one or more ionically charged starches, such as cationic starch or starches that preferably have a degree of substitution greater than 0.045., they are added to the paper pulp together with at least one optical brightener people. According to the present invention, the ionically charged starch can be added to the pulp separately or in any combination. Paper and paperboard products manufactured according to the methods of the present invention preferably exhibit increased paper brightness and / or paper fluorescence intensity compared to the same paper and paperboard that are manufactured by the same process but without the presence of cationic starch. , which has a degree of substitution greater than 0.045 and is added to the wet part of the paper machine system. In the present invention, the ionically charged starch and the optical brightening agent can be added in any order of introduction such as fed one after the other into the paper pulp. The optical brightening agent and the starch can be added in the same stage of the papermaking process or they can be added in different stages of the papermaking process, while both components are added before the pressing step of a process of paper manufacture. For example, the two components can be add within 50 minutes each other, within 40 minutes each other, within 20 minutes each other, within 10 minutes, or within 5 minutes each other, or within 2 minutes, or within 1 minute Enter yes, or even within seconds between each other in the pulp. The starch, as stated, is an ionically charged starch which is preferably a cationically charged starch or cationic starch, which preferably has a degree of substitution greater than 0.045. The loaded state of the starch refers to the complete net charge of the starch. Two or more charged starches can be used, such as two or more cationic starches. When two or more starches are used, the starches may be added as a premixed composition, or they may be added at the same time, sequentially, or in any order to the pulp, alone or in combination with one or more optical brightening agents. When two or more starches are used, one of the starches can be a neutral starch. Preferably, at least one of the charged starches has a degree of substitution ranging from about 0.045 to about 0.5, such as from about 0.07 to about 0.45 or from about 0.10 to about 0.40, or from about 0.15 to about 0.4. Other degrees of substitution can be used above and below these intervals. Generally, a degree of substitution above 0.045 is preferred and can be used. The degree of substitution may be above 0.4 and higher degrees of substitution will benefit the present invention. Preferred cationic starches include, but are not limited to, potato starches, corn starches, and other wet part starches, and combinations thereof. Specific examples of cationic starches that may be used in the present invention include, but are not limited to, BUFLOC 5521 and BUFLOC 5567 products, both available from Buckman Laboratories International, Inc., Memphis, Tennessee. Other examples include, but are not limited to, Raifix, Raisiobond, and products supplied to the industry by CIBA. With respect to optical brightening agents, one or more optical brightening agents can be used, such as two or more or three or more. For purposes of the present invention, optical brightening agents include fluorescent whitening agents. For purposes of the present invention, optical brightening agents are typically chemicals that are used to purify and / or increase the whiteness or possible brightness of paper fibers. The optical brightening agents can also be optical brightening agents and can include water soluble coloring matters. The bleaching agents optics can be fluorescent dyes that absorb invisible UV light from daylight and re-emit it in the visible spectrum, thereby increasing the brightness with excellence of whiteness on paper. When two or more optical brightening agents are used, as with starch, they can be added as a premix, sequentially, or in any order to the pulp. General classes of optical brightening agents include stilbenes, stilbene derivatives, distilbiphenyls, triazinylamino stilbene and the like. For purposes of the present invention, an optical brightening agent includes coloring agents. Examples of OBAs include stilbene disulfonate, stilbene tetrasulfonate, stilbene hexasulfonate, 4,4'-diamin stilbene, 2,2'-disulfonic acid, or stilbene derivatives. The OBAs described in U.S. Patent Nos. 5,873,913; 6,723,846; 4,025,507; and 6,464,832; and US Patent Application Publication Nos. 2004/0077515; 2004/0074021 may be used and incorporated in their entirety by reference herein. Examples of specific optical brightening agents include, but are not limited to, Blankophor, Leucophor, Tinopal, Catowhite OWA grades, Unipal, Palinil Brilliant White, Uvitex, Milkawhite, Fluolite, Kalbrite, OBA-C and W. The preferred amount of starch ionically charged, such as cationic starch, can be any effective amount to enable improved optical brightening performance, such as improvement with respect to the ISO brightness of the paper and / or fluorescence intensity of the paper. In the alttive, or in combination with this property improvement, the ionic starch, such as the cationic starch, may be added in an amount of about 0.25 to about 25 pounds per ton of dry pulp or a base of solids, or of about 1.0 pounds to 20 pounds per ton of dry pulp on a dry solid basis and more preferably from about 1 pound to about 6 pounds per ton of dry pulp on a dry solids basis. With respect to optical brightening agents, conventional amounts are used, such as from about 1 pound to about 50 pounds per ton of dry pulp, and more preferably from about 2.0 to about 10.0 pounds per ton of dry pulp on a dry solids basis . With respect to this process, this process is preferably used when manufacturing thin paper or paper that is coated or uncoated chemical pulp paper, newspaper, quality newspaper, supercalendered (SC), and weight coating grades Lightweight (LWC). The uncoated chemical pulp paper is manufacture of raw material that is drained freely. Coated chemical pulp paper is a publication grade in which the coating raw material generally does not contain more than 10% by weight of mechanical pulp. Supercalendered (SC) is calendered paper outside the machine that uses a stack that has altting chilled iron fiber rolls. The LWC are coated papers of relatively low grammage. The finished paper with newspaper paper is mainly made up of mechanical pulp, commonly used for newspaper printing papers. Preferably, the starch and the brightening agent are introduced at or prior to the introduction of the pulp into a mixing vessel. In at least one embodiment of the present invention, the optical brightening agent and the starch may be added at or prior to the introduction of the pulp into a machine container. In at least one embodiment of the present invention, the starch and the optical brightening agents can be added to the pulp prior to the gluing press. The starch and the optical brightening agent can generally be added at any location in the papermaking process and can be added prior to the silo of foamed water in a papermaking process or can be added prior to the machine container or can be added previous to Mixing vessel or can be added before or after the first refiner. The method of the present invention can be practiced on conventional papermaking machines with modifications that can be easily made in view of the present invention. The method can employ many different types of pulp or combinations thereof. For example, the pulp may comprise virgin and / or recycled pulp, such as virgin sulphite pulp, trimming pulp, a hardwood kraft pulp, a softwood kraft pulp, mixtures of such pulps, and the like. An enzyme composition can optionally be used to treat the pulp and can contain any conventional pulp-treating enzyme having cellulite activity. Other conventional papermaking components may be present as long as these other components do not adversely affect the starch, or the optical brightening agent. Preferably, the enzyme composition also exhibits hemicellulitic activity. Suitable enzymes and compositions containing enzymes include those described in U.S. Patent No. 5,356,800 to Jaquess, U.S. Patent Application No. 09 / 031,830 filed on February 27, 1998, and inttional publication No. WD 99/43780, all incorporated into the present in their totalities by reference. Other exemplary pulp-treating enzymes are BUZYME® 2523 and BUZYME® 2524, both available from Buckman Laboratories International, Inc., Memphis, Tenn. The cellulitic enzyme composition preferably contains from about 5% to about 20% by weight of enzyme. The preferred enzyme composition may additionally contain polyethylene glycol, hexylene glycol, polyvinyl pyrrolidone, tetrahydrofuryl alcohol, glycerin, water and other conventional enzyme composition additives, such as, for example, described in U.S. Patent No. 5,356,800. The enzyme can be added to the pulp in any amount, such as from about 0.001 to about 0.100% by weight of enzyme based on the dry weight of the pulp, for example, from about 0.005 to about 0.05% by weight. In one embodiment of the present invention, the enzyme composition contains at least one oligomer of polyamide and at least one enzyme. The polyamide is present in an amount effective to stabilize the enzyme. Exemplary enzyme compositions containing polyamide oligomers and enzymes are described in International published application No. WO 99/43780, which is incorporated herein by reference in its entirety. According to the present invention, the composition of enzyme may include a combination of two or more different enzymes. The enzyme composition may include, for example, a combination of a lipase and a cellulose, and optionally may include a stabilizing agent. The stabilizing agent can be a polyamide oligomer as described herein. A microparticle additive can be added to the pulp at any time during the process. The microparticle additive can modify the load of the pulp or the load of a component of the pulp. The microparticle additive may be, for example, a filler or modifier, a filler, a coagulating agent, and / or a retention aid. The microparticle additive can be a natural or synthetic hectorite, bentonite, zeolite, alumina sol, silica or any of the conventional particulate additives as are known to those of skill in the art. A biocide can be added to the treated pulp or pulp according to the conventional uses of biocides in papermaking processes. For example, a biocide can be added to the treated pulp in a mixing vessel. Useful biocides in papermaking pulps according to the present invention include biocides well known to those of skill in the art, for example, BUSAN® 1130, available from Buckman Laboratories International, Inc., Memphis, Tenn. A flow chart of a papermaking system for carrying out the method of the present invention is set forth in FIG. 1. It will be understood that the system shown is exemplary of the present invention and is in no way intended to restrict the scope of the invention. In the system of FIG. 1, a supply of starch and a supply of optical brightening agent (OBA) are added at respective desired concentrations with a flowing pulp stream to form a treated pulp anywhere in the front of the wet process as shown. The pulp supply shown represents a pulp flow, for example, supplied from a pulp containment tank or silo. The pulp supply shown in FIG. 1 can be a duct, containment or mixing tank, or another container, passage, or mixing zone for the flow of the pulp. The starch supply or OBA may be, for example, a containment tank having an outlet in communication with an inlet of the treated pulp tank. The pulp treated with the starch and OBA can be passed from the treated pulp tank through a refiner, and then through a mixing vessel where optional additives including a biocide can be combined with the treated pulp. The refiner has an entrance in communication with an outlet of the treated pulp tank, and an outlet in communication with an inlet of the mixing vessel. According to the embodiment of FIG. 1, the pulp treated in the mixing vessel is passed from a mixing vessel outlet through a communication to an inlet of a machine vessel. The mixing vessel and the machine vessel can be of any conventional type known to those skilled in the art. The machine container ensures a level head, that is, a constant pressure on the treated pulp or raw material throughout the downstream portion of the system, particularly in the headbox. In the system of FIG. 1, the drained pulp resulting from the paper making in the head box is recirculated to the foaming water silo. In the embodiment shown in FIG. 2, a cationic starch and / or OBA are added to the refined treated pulp in the mixing vessel or to the pulp box, and the system includes a conventional pulp box. The additional cationic starch can be added to the pulp box although it is not shown in FIG. 2. The system of FIG. 2 has a second refiner between the machine container and the pulp box. Other additives, which include pH adjusting agents such as alum, can also be added in the pulp box. The pH adjusting agents can be added at other points along the flow of pulp or pulp treated through the apparatus. The apparatus of the present invention may also include regulatory devices to provide a suitable concentration of OBA to the pulp flow, for example, from about 0.05 to about 2.5 weight percent OBA, based on the weight of dry pulp solids. The apparatus may include a regulating device for providing an adequate amount of the cationic starch to the pulp flow, for example, from about 0.05 percent to about 1.5 weight percent of the cationic starch, which has a degree of substitution preferably greater than 0.045, based on the weight of dry pulp solids. Other regulating or dosing devices are preferably provided for the other additives and ingredients that may be used during the method. A cleaner, for example, a centrifugal force cleaning device, may be arranged between, for example, the fan pump and the screen, according to any of the embodiments of FIGS. 1-2 previous. The present invention further relates to a method for improving the optical brightening performance at practicing one of the embodiments of the methods of the present invention which includes introducing at least one ionically charged starch, such as cationic starch, and at least one optical brightening agent to a paper pulp to form a treated pulp and then forming the pulp treated on paper or cardboard. Preferably, the improved optical brightening performance includes an increase in ISO brightness of paper and / or an increase in fluorescence intensity of the paper. These increases are compared to the same method using the same amount of optical brightening agents compared to the same method using the same amount of optical brightening agents, but without any loaded starch and / or any starch that is added prior to the glue pressing. In the present invention, the present invention provides a method for preventing mitigation of the optical brightening agent and / or retaining the color or brilliance achieved by using optical brightening agents. The improvement in optical brightener performance can be measured by either the ISO brightness of the paper or the fluorescence intensity of the paper and can be in the order of at least 5% or more, such as 10% or more, or approximately 5% to approximately 25% compared to the same paper that is manufactured in the same process with the same OBAs and quantities but without any loaded starch that is used prior to glue pressing. In addition to the benefits mentioned in the above achieved with the present invention, the present invention can additionally achieve, as an option, excellent filler retention, such as PCC, Ti02, clay and the like. In addition, the highest ash retention is achieved, and can still be achieved with a decrease in filling amounts used in view of the ability of the present invention to increase retention speed. Also, with the present invention, it is possible to achieve a reduced amount of sheet defects, as measured by ULMA defects. Particularly, less dusting, for example, in the previous section of the dryers, can be achieved, reduced holes in all categories can be achieved (for example, reduction in small holes, reduction in medium holes, reduction in small points of light) . Furthermore, with the present invention, increased drainage can be achieved, which allows for speed increases and / or steam reduction. In addition, with the present invention, the present invention can promote sizing retention and can increase FPR and / or FPAR. Also, the present invention can promote strength, such as improving the fiber to fiber and fiber to filler link. In addition, with the present invention, less breakage and / or functionality of the machine is achieved of improved paper. Also, with the present invention, a reduction in debling and dusting can be achieved. Also, with the present invention, a reduction in BOD (biological oxygen demand) and / or COD (chemical oxygen demand) can be achieved. One or more of those improvements can be achieved with the present invention, as compared when loaded starch is not used. In one or more embodiments of the present invention, the present invention can improve one or more of the following properties: (a) an increase in filler retention compared to no charged starch that is present; (b) an increase in the ash content in the sheet in the compared paper when loaded starch is not used; (c) an increase in drainage compared when loaded starch is not present; (d) an increase in sizing retention compared when loaded starch is not present; (e) a reduction in breaks compared when loaded starch is not present; (f) a reduction in debling and / or compacted powdering when loaded starch is not present. With respect to one or more of these improvements property, the improvement may be in the order of at least 2%, at least 5% or more, such as 7% or more, 10% or more, 25% or more, 50% or more, 75% or more , 100% or more, such as from 2% to 100%, from 5% to 75%, from 10% to 50%, and any of the intervals or values within these ranges, where the percent improvement is compared to same paper that is manufactured in the same process with the same OBAs, and quantities, but without any loaded starch that is used prior to the glue pressing. The particular numerical improvements detailed in the examples can be achieved here, in general, with respect to other embodiments of the present invention, which mean other OBAs, other charged starches and / or process conditions. The present invention also relates to the pulp and paper obtained from the present invention. In particular, the present invention relates to a pulp pulp or slurry containing pulp, one or more optical brightening agents, and at least one cationic charged starch, preferably having a degree of substitution greater than 0.045. The charged starch can have any degree of substitution described in the above. The amounts can be the amounts described in the above. The pulp may additionally contain other conventional ingredients, such as at least one filler, at least one biocide, at least one microparticle, so less an enzyme, at least one polymer, other starches, or any combination thereof. Similarly, the present invention relates to a paper or paperboard obtained from the present invention. In particular, the paper or paperboard can be any type of paper, such as the paper grades mentioned above, or the paper or paperboard contains pressed cellulose fibers, at least charged starch, which preferably has a degree of substitution of greater than 0.045, and at least optical brightening agent. The degree of substitution for the charged starch, such as a cationic starch, can have the various degrees of substitution mentioned in the above. As stated, paper can be thin or paper that is coated or uncoated. The paper can be newspaper, newspaper, quality paper, supercalendered, or light weight coating grades. The paper manufactured from the pulp can be recycled pulp and / or virgin. The present invention will be further clarified by the following examples, which are proposed to be exemplary of the present invention. EXAMPLES Experimental: The pulp suspension used in this example contained 70% by weight of bleached hardwood and 30% by weight of softwood bleached with a 380 mL CSF. The optical brightener used was Tinopal. Both BFL 5521 as BFL 5567 (from Buckman Laboratories International, Inc.) were cationic starches with different charge densities. During the preparation of the test sheet, 15 lb / ton (as received) of OBA was first added to the coarse pulp raw material (2.2% consistency) followed by the cationic starch. Then, the pulp feedstock was diluted to 0.4% and the test sheets were prepared by the standard Tappi T205 method. Figure 3 shows the brightness results of the prepared test sheets. The introduction of OBA increased the paper's ISO brightness from 64.0 to 65.2. In the addition of 7 lb / ton (as received) of cationic starches of BFL 5521 and BFL 5567, the brightness was further increased to 65.2 and 66.0 respectively. FIG. 4 shows the fluorescence image of the prepared paper samples. In this experiment, small pieces of paper were cut from the test sheets and taped onto the fluorescence lamp. The photo was taken in a dark room using a digital camera. As can be seen, the introduction of cationic starches increased the fluorescence intensity (samples 3 and 5). In addition, samples with higher cationic starch dosages (samples 4 and 6) exhibited higher fluorescence intensity.

Thus, cationic starches, such as starch compositions BFL 5521 and BFL 5567, improved the optical brightening performance by increasing both the ISO brightness of the paper and the fluorescence intensity of the paper (excited by UV light). In a further experiment, the effects of the starch-based coagulants of the present invention were compared against other coagulants that are conventionally used, especially polyamine and a polyDMDAAC. In this particular experiment, as shown in the table below, the fluorescence and brightness were measured for the test sheets manufactured from a pulp having 70% by weight of bleached hardwood and 30% by weight of bleached softwood. The pulp also had an OBA (OBA Leucophor) present in the amount of 15 pounds per ton of dry pulp, based on a dry solids base. In one of the samples, no coagulant was present. In two other samples, a cationic starch, according to the present invention, was present in the wet pulp in an amount of 4 pounds per ton of dry pulp based on a dry solids base. Both of these cationic starches are available from Buckman Laboratories International. The remaining four samples contained a conventional coagulant in the pulp, especially polyamine or polyDMDAAC, in an amount of 2 pounds per ton or 4 pounds per ton Dry pulp based on a dry solids base. As seen in the table below, the samples containing cationic starch with OBA had a significantly higher brightness and a significantly higher fluorescence compared to the control sample, as well as samples containing conventional coagulants that additionally contained an OBA. It is clear that the present invention provides superior brightness and fluorescence properties and that OBA is not quenched or decreased by the presence of cationic starches. 1.2 gram test sheet pH = 8.0 70% bleached hardwood 15 # / ton OBA % bleached soft wood Example 2 In one experiment, a five-day experimental test on a paper mac was conducted to determine the effects of using a cationic starch together with an optical brightener. In particular, the organic coagulant BUFLOC 5567 was used. More specifically, the coagulant BUFLOC 5567 was introduced in the traw material stage starting at 0.5 lb / ton, which gradually increased to 2 lb / ton, and then it was increased to 3 lb / ton, and then increased to 4 lb / ton for the rest of the trial. The dosage was then decreased by 1 lb / ton each reel until the assay was determined. From this experiment, it was noted that the breaks on the mac fell from an average of 2.4 breaks per day (based on an average of one month) to an average of 1.6 breaks per day during the trial. The breaks on the mac is a term understood by those skilled in the art and refers to the paper that is formed on the mac that is not broken prior to being rolled In addition, during the experiment, there was no significant impact on head loading with the addition of BUFLOC 5567 coagulant at any dose. Also, ULMA holes (only purples) were not significantly impacted during the experiment. In addition, during the experiment, it was determined that the screwing of the gluing press was faster and easier, which may be due to the better fiber to fiber bonding or better bonding achieved with the use of BUFLOC 5567 coagulant. experiment, retention gains were achieved, and even during a five-day trial, retention and distribution of fillers and other functional additives on paper were achieved. It is believed that a thirty-day experiment would show even greater increases in the retention rate. With respect to the transfer of the OBA (transfer of optical brightening agent), the level of brilliance and fluorescence were not significantly affected through the use of coagulant BUFLOC 5567. In the production of brightness grade 92, the average brightness of a week before and one week after the experiment it was 91.8 and the average fluorescence was 2.4. During the experiment, the average brightness was approximately 91.3 and the fluorescence was of about 2.2. More importantly, the use of optical brightening agent dropped significantly and still, average brightness and average fluorescence were maintained as described above. More specifically, prior to the experiment, the use of OBA was around 750-950 ml / m per side. However, during the experiment with the use of BUFLOC 5567, a significant reduction in the OBA was obtainable. Specifically, the OBA used during the experiment was around 450-550 ml / min. To meet the optical specifications. This is a complete reduction of approximately 500-700 ml / min. The load based on the hardwood level container remains constant at approximately 0.73 pounds per ton. Thus with the present invention, the amount of OBA can be significantly reduced and still levels of brightness and fluorescence levels were maintained at acceptable levels. It was also determined at one point, that the resin control additive could be removed with no effect on the complete quality of the paper. In addition, there was a significant reduction in dusting when the coagulant BUFLOC 5567 was used. Example 3 In this experiment, a forty-five day experimental trial was run on a paper mac to determine the longer term effects of using the BUFLOC 5567 coagulant in view of the OBA's efficiency. Specifically, for a period of forty-five days, the coagulant BUFLOC 5567 was used in the amount of 2.6 lbs / ton. As established, an OBA was also present. The following observations were made from the experiment: • The breaking time on the machine was reduced by 13 to 17 minutes per day when the 45 days of use were compared to 104 days without the BUFLOC 5567. • The stretch between the 2nd press and the the dryer section was reduced by 4 to 5 feet with the added drainage of BUFLOC 5567. • Ash retentions from the first step increased a minimum of 11% with the added use of BUFLOC 5567. • ULMA Small Holes decreased from 3.8 small holes per 1,000,000 linear feet to 0.75 small holes per 1,000,000 linear feet with BUFLOC 5567. • ULMA Medium Holes decreased from 5.9 medium holes per 1,000,000 linear feet to 0.4 medium holes per 1,000,000 linear feet with BUFLOC 5567. * Small Light Points ULMA decreased by 210 small light points per 1,000,000 linear feet at 40 small points of light per 1,000,000 linear feet with BUFLOC 5567.

Breakdown Time Data Without BUFLOC With BUFLOC Difference 5567 5567 Days 104 45 Minutes 149,760 64,800 Totals Minutes 5753 1703 Break Time Totals 3,841% 2,628% 1,213% Break,% Breakdown Location Data Breaking Breaking Breaking Breaking the Part of the Total Reel for Wet Press by Gluing Machine by Day Day Day by Day 104 Days 0.26 1.34 0.27 1.87 without BUFLOC 5567 45 Days with 0.20 1.00 0.18 1.38 BUFLOC 5567 Difference 0.06 0.34 0.09 0.49 Breakdown per Day Minutes 43.66 28.93 11.89 28.67 Average Breakthrough by Location Minutes 2.60 9.74 1.09 13.43 Total savings. per Day During the course of the evaluations performed with the BUFLOC 5567, as it was introduced to the system, the vacuum of suction would decrease and the humidity of the gluing press would decrease until the steam control of the 6th section took it back to the target. As the evaluations took place, the stretching between the 2nd press and the dryer section was reduced with this added drainage. At equal refiner charges, press charges, charges filling and equivalent suction vacuum, the stretch was reduced by 4 to 5 feet with 2.6 Lbs / T of the BUFLOC 5567. The suction vacuum decreased from 17.78 '' to 17.25 '' with the introduction of BUFLOC 5567. The Press Moisture Gluing Machine decreased from 3.0% to 2.8% until the steam controller effect of the 6th section. The vapor pressure of the 6th section dropped from 59.5 psig to 52.5 psig. The effect of BUFLOC 5567 on the retentions is more pronounced with the ash retentions of the first step (FPAR) in comparison with the complete retentions. The introduction of BUFLOC 5567 during the trials indicated a complete increase in retention of the first step (FPR) from 2% to 5%. An increase of 11% to 20% in FPAR was observed with the introduction of BUFLOC 5567. Evaluation on 92 BCP (brightness copy paper) APAM (1.15 lbs./T, Microparticles (1.35 lbs./T) and Use of Filler (16%) at 2,850 lbs / T of BUFLOC 5567, FPR increased 7% and FPAR increased 22% Use of BUFLOC 5567 of 3.0 lbs./T, APAM (0.7 lbs./T, Microparticle ( 1.0 lbs / T) and Filler Use Constant (15%), 2-4% increase in FPR and 11-13% increase in FPAR During the introduction of BUFLOC 5567 to the suction of the fan pump, there was evidence of the filler and the reading of the weight that indicated that the BUFLOC 5567 was having an effect on the fines and retention of the filler. Each time it was introduced, the reading and the weight of the filler would increase until their respective controllers took everything back to the target. The following is a summary of the filler trends. An ABB scanner was used for the measurements. While using the BUFLOC 5567, ULMA defects were reduced. Improvements in ash retentions as set forth in the above should lead to a reduction in defects. Also, as noted during the evaluations, a reduction in dusting was observed in the previous main section dryers. This would also lead to reduction in ULMA defects. The following is a summary of the historical data reviewed: * ULMA Small Holes decreased from 3.8 small holes per 1,000,000 linear feet to 0. 75 small for a 1,000,000 linear feet with BUFLOC 5567. • ULMA Medium Holes decreased from 5.9 medium holes per 1,000,000 linear feet to 0. 4 medium holes per 1,000,000 linear feet with BUFLOC 5567. * ULMA Small Light Dots decreased from 210 small light points per 1,000,000 linear feet to 40 small light points per 1,000,000 linear • The only negative trend occurred with the ULMA Big Dark Points. It is not clear as to how this happened with all the positive results observed in the other defect categories. The ULMA Big Dark spots increased from 19 to 44 dark spots per 1,000,000 linear feet. During the initial evaluation of BUFLOC 5567, a 7.2% increase in fluorescence was observed in the same use of OBA. This indicated that BUFLOC 5567 was helping to retain the OBA. The use of OBA decreased from 163 oz./T to 149 oz./T over 92 BCP to achieve the target fluorescence. Example 4 In a further experiment, the effects of the present invention were studied in a foamy water system containing an OBA. Prior to the introduction of the BUFLOC 5567 coagulant, the baseline for the paper having a brightness of 92, was a fluorescence of 2.5, and the baseline for the paper having a brightness of 96, was a fluorescence of 6.0. When the coagulant BUFLOC 5567 was introduced at a rate of 1.5 kg / t, the fluorescence averaged 3.2 for the grade 92 brightness paper, and when the coagulant BUFLOC 5567 was introduced at a rate of 2.0 kg / t, fluorescence averaged 2.6 for paper that has a brightness of 92. In this study, the BUFLOC 5567 was introduced on the suction side of the screens. Also, with respect to paper having a brightness of 96, the OBA consumption was reduced to achieve comparable brightness. In particular, historically, the amount of OBA was 3700-4300 ml / min per side. During the use of the coagulant BUFLOC 5567, at a rate of 1.5 kg / t, the OBA averaged an amount of 2400 ml / min per side, which was an average of a 40 percent reduction in OBA consumption with no oscillation greater in the brilliance of the paper. In addition, dusting studies were performed based on the non-BUFLOC 5567 coagulant which is present compared to the BUFLOC 5567 coagulant at a dosing rate of 1.5 kg / t - and a dosing rate of 2.0 kg / t. The following table provides the results.

From these results, it can be clearly seen that the loaded starch coagulant can be used in all grades of paper to improve the brilliance and fluorescence efficiency as well as improved retention, drainage, water elimination and / or formation. In addition, as shown in the studies, the use of loaded starch coagulant significantly improves retention and distribution of fillers and other functional additives while reducing dusting, tarnishing, leaf defects, and / or holes, and allows for The superior paper machine and ho a quality. Applicants specifically incorporate the complete contents of all references cited in this description. In addition, when an amount, concentration, or other value or parameter is given as either a range, preferred range, or a list of superior preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed to from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether the ranges are disclosed separately. Where a range of numerical values is quoted herein, unless otherwise stated, the range is proposed to include the endpoints thereof, and all integers and fractions within the range. It is not proposed that the scope of the invention be limited to the specific values quoted when defining a range.

Other embodiments of the present invention will be apparent to those skilled in the art from consideration of the present specification and the practice of the present invention disclosed herein. It is proposed that the present specification and examples be considered as exemplary only with a scope and true spirit of the invention which is indicated by the following claims and equivalents thereof.

Claims (22)

1. CLAIMS 1. A method for manufacturing paper or paperboard, characterized in that it comprises introducing a) at least one charged starch, which has a degree of substitution greater than 0.045, and b) at least one optical brightening agent, in any order, and same time or at a different time, to a paper pulp to form a treated pulp and then to form the treated pulp into paper or cardboard.
2. 2. The method of compliance with the claim 1, characterized in that the charged starch is a cationic starch. 3. The method according to claim 1, characterized in that the charged starch is a mixture of two or more charged starches. 4. The method according to claim 1, characterized in that at least two charged starches are introduced. The method according to claim 1, characterized in that the optical brightening agent is a stilbene compound or a di-styrylbiphenyl compound. 6. The method according to claim 1, characterized in that the optical brightening agent is a coloring matter. 7. The method of compliance with the claim 1, characterized in that the charged starch has a degree of substitution of about 0.01 to about 0.5. The method according to claim 1, characterized in that the charged starch has a degree of substitution of about 0.15 to about 0.42. 9. The method according to claim 1, characterized in that the charged starch has a degree of substitution of about 0.12 to about 0.
3. 3. The method according to claim 1, characterized in that the method forms thin paper or coated or uncoated chemical pulp paper, newspaper, quality newspaper, supercalendered, or lightweight coated paper grades. The method according to claim 1, characterized in that at least one charged starch and the at least one optical brightening agent are introduced at or prior to the introduction of the pulp into a mixing vessel. The method according to claim 1, characterized in that the at least one charged starch and the at least one optical brightening agent are added at or prior to the introduction of the pulp into a machine container. 13. The method according to claim 1, characterized in that the at least one starch loaded and the at least one optical brightening agent is introduced prior to a size press. The method according to claim 1, characterized in that the charged starch is added in an amount of about 1 to about 20 pounds per ton of dry pulp. 15. The method according to claim 1, characterized in that the charged starch is added in an amount of about 0.25 to about 5 pounds per ton of dry pulp. 16. A method for improving optical brightening performance, characterized in that it comprises introducing a) at least one charged starch, and b) at least one optical brightening agent, in any order, at the same time, or at a different time, to a pulp to form a treated pulp and then form the treated pulp into paper or cardboard. The method according to claim 16, characterized in that the improvement in optical brightener performance includes an increase in the ISO brightness of the compared paper - to the same method but with no loaded starch that is added prior to any size press. 18. The method of compliance with the claim 16, characterized in that the optical brightening performance includes an increase in the fluorescence intensity of the paper as compared to the same method that is practiced, but with no loaded starch that is added prior to any size press. 19. The paper or cardboard, characterized in that it is obtained from the method of claim 1. 20. A pulp composition, characterized in that it comprises pulp, at least one charged starch having a degree of substitution of greater than 0.045 and at least one optical brightening agent. 21. The pulp composition according to claim 20, characterized in that the charged starch is a cationic starch and has a degree of substitution greater than 0.045 to about 0.5. 22. The method according to claim 16, characterized in that at least one of the following properties is improved: (a) an increase in retention of the filler compared to no loaded starch that is present; (b) an increase in the ash content of the sheet in the compared paper when no loaded starch is used; (c) an increase in drainage compared when no loaded starch is present; (d) an increase in size retention compared when no loaded starch is present; (e) a reduction in breaks compared when nothing of loaded starch is present; (f) a reduction in the dissolving and / or powdering compared when no loaded starch is present.