BRPI0711227A2 - method for increasing retention and drainage in a papermaking process - Google Patents

Abstract

METHOD FOR INCREASING RETENTION AND DRAINAGE IN A PAPER MANUFACTURING PROCESS The invention relates to a paper or cardboard produced from a pulp comprising cellulose fibers and an effective amount of SMS. In addition, a method for increasing retention and dehydration during the papermaking process is also presented. The method involves adding an effective amount of SMS to said papermaking process. The invention also features a method for increasing retention and drainage in a papermaking process, which comprises the steps of: adding an effective amount of starch and an effective amount of SMS to a pulp in said papermaking process paper, in which said starch is selected from the group consisting of: tapioca starch; potato starch; maize starch; glossy corn starch; rice starch; and wheat starch. In addition, the invention comprises a method for increasing retention and drainage in a papermaking process, which comprises the steps of: adding an effective amount of modified starch and an effective amount of SMS to a slurry of said process papermaking.

Description

METHOD FOR INCREASING RETENTION AND DRAINING IN PAPER MANUFACTURING

FIELD OF THE INVENTION This description relates to a method for increasing retention and dehydration during a papermaking process by the addition of a synthetic metal silicate to the papermaking process, as well as to paper or paper made from a paper silicate. synthetic metal. This description also relates to a method for increasing retention and dehydration during a papermaking process by the addition of a starch and a metalsynthetic silicate to the papermaking process.

BACKGROUND OF THE INVENTION

Retention and dehydration systems for use in papermaking currently use any component or combination of the following components: flocculant, coagulant, and inorganic particulate. When one or more of these chemical compounds are added to an aqueous pulp containing cellulose fibers, fines, fillers, and other additives, and subsequently introduced into a paper machine, sheet formation is facilitated with improved retention and dehydration. Throughout recent papermaking history several different inorganic particulates have been used as part of the retention and dehydration system. The inorganic particulate ranges from colloidal silica or silica sols, modified silica sols and borosilicate sols, to smectite clayeyers, used alone or in combination with each other. Still, there is a need for a new synthetic inorganic particulate that will provide even greater retention and dehydration without sacrificing the properties of paper or cardboard.

BRIEF DESCRIPTION OF THE INVENTION The present invention also provides a method for increasing retention and dehydration during the papermaking process which comprises the step of: adding an effective amount of SMS to said papermaking process.

The present invention provides a paper or paper made from a pulp comprising cellulose fibers and an effective amount of SMS and starch.

The present invention also provides a method for increasing retention and dehydration during the papermaking process which comprises the step of: adding an effective amount of SMS and starch to said papermaking process.

DETAILED DESCRIPTION OF THE INVENTION

"SMS" means a synthetic metal silicate of the following formula: (Mg3-xLix) Si4Na0.33 [Fy (OH) 2 -y] 2O10, wherein: χ = 0 to 3.0; and y = 0.01 to 2.0.

The SMS of the present invention can be obtained by combining simple lithium magnesium silicates and fluoride salts in the presence of mineralizing agents and by subjecting the resulting mixture to hydrothermal conditions. As an example, a silica gel with magnesium hydroxide and lithium fluoride may be combined in a refluxing aqueous solution for two days to obtain SMS. (See Industrial & Chemical Engineering Chemistry Research (1992), 31 (7), 1654 , which is incorporated herein by reference). SMS can also be obtained directly from Nalco Company, Naperville, IL 60563. Currently, SMS is available as a Nalco product no. DVP4J001.

"Papermaking process" means a method of producing paper products from pulp, which comprises forming an aqueous cellulosic pulp, draining the pulp to form a sheet and drying the sheet. The steps of forming the papermaking pulp providing, draining and drying can be performed in any conventional manner generally known from the skilled artisan.

"COD" means chemical oxygen demand.

"GCC" means crushed calcium carbonate.

"HWK" means bleached hardwood kraft.

"MCL" means average rope length.

"SWK" means softwood bleached kraft.

"TMP" means thermal mechanical pulp.

"PCC" means precipitated calcium carbonate.

"CTMP" means chemical thermal mechanical pulp.

"GWD" means ground wood pulp.

"DIP" means pulp with ink removed.

"kg" means kilogram.

"T" means ton.

As indicated above, the present invention provides a method for increasing retention and dehydration during the papermaking process which comprises the step of adding an effective amount of SMS. SMS may be added to said papermaking process as a solid or as a dispersion. In one embodiment, the SMS is added to a folder located in said papermaking process. The pulp may comprise one or more cellulose fibers, fines and fillers dispersed in water.

In another embodiment, the effective amount of SMS added to said pulp ranges from 0.001 to 6 kg / t based on our pulp solids, or from 0.01 to 3 kg / t based on pulp solids.

In another embodiment, a colloidal silica is added to the pulp of said papermaking process. In an additional embodiment, the weight ratio of the silica-colloidal to the SMS ranges from 0.01: 1 to 100: 1. In another embodiment , a colloidal borosilicate is added to said pulp of said papermaking process. In a further embodiment, the weight ratio between colloidal oborosilicate and SMS ranges from 0.01: 1 to 100: 1.

In another embodiment, one or more polymers may be added to the paste before, after, or in combination with addition of said SMS. Polymers can be selected from the group consisting of the following polymer types: cationic; anionic; nonionic; dipolar; and amphoteric.

In a further embodiment, the cationic polymers are selected from the group consisting of: natural carbohydrates; synthetic branched linear crosslinked flocculants; organic microparticles; acrylamide copolymers diallyl dimethyl ammonium chloride and; dimethyl and acrylamide aminoethyl (meth) acrylate copolymers; deacrylamide and (meth) acrylic acid copolymers; dimethyl aminoethyl (meth) acrylate acrylamide copolymers; dimethyl-methyl chloride-methyl quat eacrylamide dimethyl (meth) acrylate copolymers; and dimethyl (meth) acrylate terpolymers, acrylamide, and (meth) acrylic acid. An example of the aforementioned organic microparticles is found in U.S. Pat. No. 5,274,055, to Honig and Harris, which is incorporated herein by reference. In yet another embodiment, the natural carbohydrate types are selected from the group consisting of: guar gum and starch.

In a further embodiment, the anionic polymers are selected from the group consisting of: acrylic acid homo-polymers, and copolymers of methacrylamide 2-acrylamido-2-methyl propane sulfonate with acrylamide or methacrylamide.

In a further embodiment, the nonionic polymers are selected from the group consisting of: depolyethylene oxide and polyacrylamide. In another embodiment, one or more inorganic coagulants, or inorganic coagulants, or a combination thereof, are added to said paste. In yet another embodiment, the organic coagulants are polyalkylene polyamines prepared from dimethyl amine and ethylene imines epichlorohydrin. In yet another embodiment, inorganic coagulants are selected from the group consisting of: alum; polyaluminium chloride and polyaluminium sulfate sulfate.

In another embodiment, the invention comprises a method for increasing retention and dehydration during a papermaking process, which comprises the steps of adding an effective amount of SMS, wherein said SMS is added to a pulp of said manufacturing process. of paper; and providing a paper or cardboard machine and forming a dry paper or cardboard. In an additional embodiment, the SMS is added to said paste prior to dehydration and the formation of a paper or dry cardboard on a paper machine or cardboard.

As indicated above, the present invention provides a method for increasing retention and drainage in a papermaking process which comprises the steps of: adding an effective amount of starch and an effective amount of SMS to a pulp of said papermaking process. wherein said starch is selected from the group consisting of: tapioca starch; potato starch; corn starch; glossy cornstarch; rice starch; Wheat bread. In one embodiment, one or more additional polymers may be added to the paste. In yet another

In this embodiment, the polymers are selected from the group consisting of: cationic polymers; anionic polymers, nonionic polymers; dipolar polymers; and amphoteric polymers. In another embodiment, starch is added to said pulp before, after, or in combination with the addition of SMS.

In another embodiment, an effective amount of said amount is added to the pulp of said papermaking process in an amount of approximately 0.1 to about 25 kg / t based on the solids in the pulp.

In another embodiment, an effective amount of said amount is added to the pulp of said papermaking process in an amount of approximately 2.5 to about 12.5 kg / t based on the solids in the pulp.

As indicated above, the present invention provides a method for enhancing retention and drainage in a papermaking process which comprises the steps of: adding an effective amount of amidomodified and an effective amount of SMS to a pulp of the papermaking diode. paper. In one embodiment, one or more additional polymers may be added to the papermaking process. In yet another embodiment, the polymers are selected from the group consisting of: cationic polymers; anionic polymers; nonionic polymers; dipolar polymers; and amphoteric polymers.

In another embodiment, the modified starch is added to said paste before, after, or in combination with addition of said SMS.

In another embodiment, the modified starch is selected from the group consisting of: tapioca starch; potato starch; maize starch; glossy cornstarch; rice starch; and wheat starch.

In another embodiment, the eccationic or amphoteric modified starch.

In another embodiment, the pulp is a thin dough or a thick dough. In another embodiment, an effective amount of modified dimer is added to said pulp of said papermaking process in an amount of from about 0.1 to about 25 kg / t, based on the solids in the paste.

In another embodiment, an effective amount of modified amine is added to said pulp of said papermaking process in an amount of from about 2.5 to about 12.5 kg / t based on the pastes solids.

The present invention will be further described in the following examples, which show various methods of application, but do not lend themselves to limiting the invention prescribed by the appended claims.

Example 1

A synthetic lightweight coated thin dough which has a consistency of 0.7% by weight has been prepared. Fine dough solids consist of 50 wt% dry hydrogen peroxide blended TMP, 25 wt% softwood bleached kraft, 14.5 wt% kaolin clay, and 10.5 wt% ultrafine GCC. The blended TMP consists of 80 wt% hardwood fibers and 20 wt% softwood fibers. Targeted Madeiramole Kraft is a dry coating pulp purchased from Weldwood, Hinton Canada. Softwood kraft was pulped into deionized water and whipped to a 360 ml Canadian Starndard Freeness index. Kaolin clay was purchased from Imerys, 100 Mansell Court East, suite 300, Roswell, G 30074, while GCC was obtained from Omya North America, 100 North Point Center East, suite 310, Alfaretta, GA 30022. The thin mass was produced from coarse parsley by using the targeted mixed TMP filtered material and deionized water containing 2.0 mM calcium, 0.23 mM magnesium, 4.9 mM sulfate and 21.8 mM sodium. An appropriate amount of a salt solution was used with the TMP filtered material to obtain the 0.9% by weight consistency with 950 mg / l COD, a pH of 8.2, and a conductivity of 2500 Micros / cm.

The cationic starch used herein is Solvitose N and is available from Avebe, Prins Hendrikplein 20, 9641 GKVeendam, The Netherlands. The commercial product used in this example is PC 1131, which is a non-fluoride synthetic lithium sodium metal silicate and can be obtained from Rockwood Specialties, Ltd, Widnes, Cheshire, UK. Nalkat® 2020 and 61067 are commercial products available from Nalco Company, 1601 West DiehlRoad, Naperville, IL. 60563.

Flocculation activity was measured by Focused Beam Reflectance Measurement (FBRM), also known as Scanning Laser Microscopy or SLM, using the Lasentec ™ M500 (Lasentec, Redmond, Washington). A description of the theory behind the FBRM operation can be found in Preikschat, FK and Preikschat, E., in "Apparatus and Method for Particle Analysis", United States Patent Office, 4,871,251, 1989, which is incorporated herein by title. of reference. The following references are incorporated by reference and describe in detail how this technique is used to measure performance and how it correlates with paper machine experience: Gerli, A., Keiser, Β. A., and Surya, Ρ. I., "The use of focused beam reflectance measurement in the development of a new nanotize particle", AppitaJ., 54 (1), 36-40 (2001); Clemencon, I. and Gerli, A., "The Effect of Flocculant / Microparticle Retention Programs on Flake Properties", Nord. Pulp Pap. Res. J., 14 (1), 23-29 (1999); Gerli, A., Oosterhof, F., and Keiser, Β. A., "An Inorganic Nanotize Particle - Part of a New Retention / Dehydration System", Pap. Technol. (Bury, United Kingdom), 40 (8), 41-45 (1999). The change in the length of the numeric chlamydia or fine mass MCL as a function of the timeout to characterize a flocculation response. The change in MCL caused by particulate addition correlates with additive performance in the papermaking process where higher AMCL (mean string length change) indicates better performance. Peak change in MCL provides a representation of the speed and extent of flocculation under the present shear conditions.

300 ml of lightweight synthetic coated dough was poured into a 500 ml glass beaker and placed on the Focused Beam Reflectance Measurement (FBRM) bench. Mixing was started at 710 rpm. Coagulant, starch, flocculant and particulate were added as indicated in the table entitled "Sequence of Addition".

Addition Sequence

Event Time

0 Start of mixing at 710 rpm

6 Add 4 kg / ton of Nalkat® 2020

21 Add 5 kg / ton Solvitose-N Starch

51 Add 1.5 kg / ton of 61067

96 Add Particulate

In this example, SMS performance is compared to that of the commercial product. The change in the average chord is compared for the samples. Results are illustrated in the following table.

<table> table see original document page 10 </column> </row> <table>

Note: Inorganic particulate is added in a base of active ingredients.

As can be seen from this data, the SMS gives a significantly higher response to deflocculation compared to the commercial product. This higher SMS flocculation response has been shown to correlate with greater fines particle retention during papermaking.

Example 2

A thin slurry of synthetic alkaline thin paper mixed at a consistency of 0.5 wt% was prepared. The slurry solids are composed of 32 wt% SWK, 48 wt% HWK, and 20 wt% GCC. Ultra thin. SWK is prepared from dry coating pulp obtained from a plant located in Alberta Canada, retransformed into deionized water at a consistency of 2-4% by weight and up to a Canadian Standard Freeness Index (CSF) of 360ml. HWK was prepared separately from the dry-covering pulp from a northern United States plant, retransformed into pulp in deionized water to a consistency of 2-3 wt%, and blended to a CSF index of 360 ml. GCC was Ultrafine obtained from Omyafil. The corresponding thick slivers and GCC were combined and diluted with deionized water containing 1.5mM calcium, 0.74mM magnesium, 2.2mM sodium, 2.99mM chloride, 0.75mM sulfate and 2.2mM of baking soda. The slurry was 0.5 wt% consistency, with a pH of 8.1 and a conductivity of 600 microS / cm.

The comparative particulate in this example is Laponite®RD commercially available from Rockwood Specialties, Ltd, Widnes, Cheshire, United Kingdom. Laponite® RD is a synthetic hydrous sodium, lithium and magnesium silicate which is identified by CAS No. 533320-86-8 and has a typical chemical composition based on weight percentage: SiO2 59.5; MgO27.5; Li 2 O 0.8; and Na 2 O 2.8.

300 ml of the synthetic alkaline thin paper pulp was poured into a 500 ml glass beaker and placed on the FBRM. Mixing was started at 710 rpm. Starch, sweetener and inorganic particulate were added in the following addition sequence:

<table> table see original document page 12 </column> </row> <table>

The application of FBRM is described in the preceding example. In this example, SMS is compared to Laponite RD. The results are summarized in the following table.

<table> table see original document page 12 </column> </row> <table>

Note: Inorganic particulate is added in a base of active ingredients.

As can be seen from these data, the SMS provides a significantly higher deflocculation response compared to the previously existing and commercially available synthetic hydrous sodium, lithium and magnesium silicate known as Laponite RD. The larger response of SMS-generated flocculation indicates greater fines retention during papermaking compared to what is currently available.

Example 3

In this example, the dehydration performance of SMS is compared to that of a commercially available material in a lightweight coated paste obtained at a Canada plant. The fiber composition of the pulp is shown in the table below. The cationic starch used in this study was Cato31, which is commercially available from National Starch, 742 Grayson Street, Berkeley, CA 94710-2677. The PCC is produced at the plant and was obtained at it. Nalkat® 7655 and Nalco 7526 are commercial products available from NalcoCompany, 1601 West Diehl Road, Naperville, IL 60563. The commercial product used in this example is PC 1131, which is a synthetic hydrous sodium and lithium metal silicate other than fluoride and can be obtained from RockwoodSpecialties, Ltd, Widnes, Cheshire, UK.

Table. Pulp fiber composition (% by weight) for Example 3

<table> table see original document page 13 </column> </row> <table>

The mixed fiber and filler solids were diluted with white water to a consistency of 0.7% by weight.

Vacuum dehydration analysis of the products was performed using the Vacuum Drain Tester (here indicated as VDT).

The VDT is a self-covering pulping device, which means that a pulp-containing pulp is drained under vacuum onto a filter paper or a yarn, resulting in the formation of an overlapping pulp. Thus, it is similar in principle of operation and provided dehydration information to other vacuum dehydration devices described in the literature (eg, see Forsberg, S. and Bengtsson, M., "The Dynamic Drainage Analyzer, (DDA)", Proceedings Tappi 1990 Papermaker1S Conference, pages 239-45, Atlanta, GA, April 23-25, 1990, which is incorporated by reference). The VDT used herein, identified as VDT +, which is available from NalcoCompany, 1601 West Diehl Road, Naperville, IL760563, has been modified so that the mix of chemical additives with binder was made in an upper chamber of the instrument.

Subsequently, the treated pulp is transferred by the gravity of the upper mixing chamber to the vacuum dehydrating chamber. The dehydration rate, in ml / s, was calculated when determining the time required to collect 400ml of filtered material or white water. The operating conditions are summarized in the table below.

Table: VDT + Test Conditions

<table> table see original document page 14 </column> </row> <table>

The results of the comparison of dehydration are shown in the table below. As can be seen, a higher dehydration rate, i.e. 15.7 ml / s, was obtained with the inorganic particulate of the present invention, oSMS, compared to the commercial product.

<table> table see original document page 14 </column> </row> <table>

Note: Inorganic particulate is added in a base of active ingredients.

Example 4

In this example, the effect of various modified starches on the dehydration performance of SMS is determined in a 100% mass of TMP targeted with paper umusine peroxide in Canada. The characteristics of the dough are given in table I.

Table I - Characteristics of peroxide-targeted TMP mass

<table> table see original document page 15 </column> </row> <table>

The cationic cornstarch used in this study is Cat 31, commercially available from National Starch, 742 Grayson Street, Berkeley, CA 94710-2677. The cationic detapioca starches used in this study are medium and high load Dinabond 132 andDinabond 180 and, respectively, commercially available from International AdditiveConcepts, 380 Crompton Street, Charlotte, NC, 28273-6214. The cationic potato starch used in this study is Topcat771, commercially available from Penford Products, 1001 First Street, P.O. Box 428, Cedar Rapids, IA, 52404-2175. They are described in Table II.

Table II Measured charge density of various starches

<table> table see original document page 15 </column> </row> <table>

The flocculant used is 6D16, which is commercially available from Nalco Company, 1601 WestDiehl Roadf Naperville, IL 60563. The gravity dehydration analysis of the programs was performed using the dynamic filtration system (DFS-03) manufactured by Mutek (BTG, Herrching , Germany). During the measurement of dehydration, 1 liter of mass is introduced into the subjected agitation compartment at 800 rpm shear during the addition of chemical additives as described in table III. The mass is drained through a 25 mesh screen for 60 seconds and the amount of filtered material is determined gravimetrically for the drainage period.

Table III. Dynamic Filtration System Test Conditions (DFS-03)

<table> table see original document page 16 </column> </row> <table>

The results of comparing dehydration paraSMS with the various modified starches described above in Table II are given in Table IV as the donation mass collected after 60 seconds. The mass of TMP targeted with peroxide used is described in Table I. As can be seen, significantly higher dehydration performance was observed for the 6D16 / SMS program in the presence of potato and tapioca starches compared to corn starch.

Table IV. Dehydration performance of 6D16 / SMS program with different modified starches 6D16 dosed at 0.6 kg / ton, SMS dosed at 2 kg / ton

<table> table see original document page 16 </column> </row> <table>

Example 5

This example demonstrates the effect of the various modified starches described in table II on the SMS dehydration performance using a mass described in table V of a paper mill in Canada.

Table V. GWD / GWD Peroxide / DIP / CTMP Mass Characteristics

<table> table see original document page 17 </column> </row> <table>

The cationic cornstarch used in this study is Cat 31, commercially available from National Starch, 742 Grayson Street, Berkeley, CA 94710-2677. The cationic detapioca starches used in this study are medium and high load Dinabond 132 andDinabond 180, respectively, commercially available from International AdditiveConcepts, 380 Crompton Street, Charlotte, NC, 28273-6214. The cationic potato starch used in this study is Topcat771, commercially available from Penford Products, 1001 First Street, P.O. Box 428, Ceder Rapids, IA, 52404-2175. They are described in Table II.

The gravity dehydration test was performed using the Dynamic Fitment System (DFS-03) manufactured by Mutek (BTG, Herrching, Germany). During the measurement of dehydration, 1 liter of the mass is introduced into the stirring compartment and sheared at 800rpm during the addition of the chemical additives as described in Table III. The mass is drained through a mesh screen for 60 seconds and the amount of filtered material is determined gravimetrically for the drainage period. The flocculant used for some of the tests is 61067 which is commercially available from Nalco Company, 1601 WestDiehl Road, Naperville, IL 60563.

The dehydration results for SMS dosed at 1.0kg / t with cationic corn, potato and tapioca starches and the 1.0l / kg dosloculant are shown in Table VI as the drainage mass collected after 60 seconds. Higher drainage masses were obtained in the presence of medium-load detapioca and potato starches compared to medium-load corn starch, indicating a better performance of roasting for these programs compared to the medium-load corn starch program. Similarly, a higher drainage performance was observed for medium-load detapioca starch compared to medium-load maize starch for tests performed without the program part flocculant as shown in table VII.

Table VI. Dehydration performance of 61067 / SMS program with different modified starches, 61067 dosed at 1.0 kg / t, SMS dosed at 1.0 kg / t

<table> table see original document page 18 </column> </row> <table>

Table VII. Dehydration performance of SMS program with different modified starches, SMS dosed at 2.0 kg / t

<table> table see original document page 18 </column> </row> <table>

Claims (20)

1. METHOD FOR. Increasing retention and drainage in a papermaking process, characterized by the steps of: adding an effective amount of starch and an effective amount of SMS to a pulp of said papermaking process, wherein said starch is selected. the group consisting of: tapioca starch; potato starch; corn starch; glossy cornstarch; rice starch; Wheat bread. Method according to claim 1, characterized in that said starch is added to said paste before, after, or in combination with the addition of said SMS. Method according to claim 1, characterized in that an effective amount of starch is added to said pulp of said papermaking process in an amount of approximately 0.1 to about 25 kg / t based on the solids in the feedstock. folder. Method according to claim 1, characterized in that an effective amount of starch is added to said pulp of said papermaking process in an amount of approximately 2.5 to approximately 12.5 kg / t based on solids in the paste. Method according to Claim 1, characterized in that an effective amount of SMS is added to said pulp in an amount of from about 0.001 to about 6 kg / t based on the solids in the pastes. Method according to claim 1, characterized in that an effective amount of SMS is added to said pulp in an amount of from about 0.01 to about 3 kg / t based on the solids in the pulp. 7. METHOD FOR. Increasing retention and drainage in a papermaking process, characterized by the steps of: adding an effective amount of modified starch and an effective amount of SMS to a pulp of said papermaking process. Method according to claim 7, characterized in that said modified starch is added to said paste before, after, or in combination with the addition of said SMS. Method according to claim 7, characterized in that said modified starch is selected from the group consisting of: tapioca starch; potato starch; maize starch; glossy cornstarch; rice starch; and wheat starch. Method according to claim 7, characterized in that said modified eccathonic or amphoteric starch. Method according to claim 7, characterized in that said pulp comprises one or more cellulose fibers, fines, and fillers which are dispersed in water. A method according to claim 1, characterized in that said pulp comprises one or more cellulose fibers, fines, and fillers which are dispersed in water. Method according to claim 7, characterized in that said paste is a thin or thick mass. Method according to claim 1, characterized in that said paste is a thin or thick mass. Method according to claim 7, characterized in that it further comprises the addition of one or more polymers. Method according to claim 1, characterized in that it further comprises the addition of one or more polymers. Method according to claim 7, characterized in that an effective amount of said modified starch is added to said pulp of said papermaking process in an amount of from about 0.1 to about 25 kg / t with based on the solids in the paste. Method according to claim 7, characterized in that an effective amount of said modified starch is added to said pulp of said papermaking process in an amount of from about 2.5 to about 12.5 kg / t. , based on napasta solids. Method according to claim 7, characterized in that an effective amount of said SMS is added to said pulp in an amount of from about 0.001 to approximately 6 kg / t based on our pulp solids. Method according to claim 7, characterized in that an effective amount of said SMS is added to the pulp in an amount of from about 0.01 to about 3 kg / t based on the solids in the pulp.