Document VjZ8nKRk0mDVvEXEZKgdg1Rk4

(i2) United States Patent Lasmarias et al. US006824651B2 US006824651B2 (io) Patent No.: US 6,824,651 B2 (45) Date of Patent: Nov. 30,2004 (54) TALC COMPOSITION AND USE IN PAPER PRODUCTS (75) Inventors: Vicente Lasmarias, Highlands Ranch, CO (US); Shripal Sharma, Highlands Ranch, CO (US); Alexis Layne, Littleton, CO (US) (73) Assignee: Luzenec America, Inc., Centennial, CO (US) ( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 12 days. (21) Appl. No.: 10/404,786 (22) Filed: Mar. 31, 2003 (65) Prior Publication Data US 2003/0205344 A1 Nov. 6, 2003 Related U.S. Application Data (63) Continuation of application No. 10/005,722, filed on Nov. 2, 2001, now Pat. No. 6,565,646. (51) Int. Cl.7 .......................... D21H 17/68; D21H 17/63 (52) U.S. Cl........................ 162/181.6; 162/158; 162/175; 162/178; 162/172; 162/168.3 (58) Field of Search ............................ 162/181.1-181.6, 162/164.1, 168.3, 164.6, 168.2, 158, 175, 172, 178; 106/801, 287.1, 286.6, 469 (56) References Cited U.S. PATENT DOCUMENTS 4,295,933 A 10/1981 Smith 162/168.3 4,495,245 A 4,710,270 A 5,244,542 A 5,454,864 A 5,458,679 A 5,492,560 A 5,516,405 A 5,972,100 A 6,033,524 A 6,565,646 B l 2003/0096143 A l 2004/0065419 A l 1/1985 Zunker ............................ 428/403 12/1987 Sunden et al.................... 162/175 9/1993 Bown et al................... 162/164.3 * 10/1995 Whalen-Shaw ................ 106/416 * 10/1995 Fairchild ........................ 106/465 2/1996 Fairchild .................. 106/204.01 5/1996 De Witt ....................... 162/164.1 10/1999 Dumas ........................ 106/501.1 3/2000 Pruszynski et al.............. 162/165 * 5/2003 Lasmarias et al.............. 106/801 * 5/2003 Lasmarias et al.............. 428/702 * 4/2004 Lasmarias et al.................. 162/5 FOREIGN PATENT DOCUMENTS WO WO 01/86067 11/2001 OTHER PUBLICATIONS R. A. Gil in "Applications of Wet-End Paper Chemistry: Fillers for papermaking" 1995, Blackie Academic & Profeesional, Edited by Che On Au and Ian Thorn; pp 54-59.* * cited by examiner Primary Examiner---Jos A. Fortuna (74) Attorney, Agent, or Firm--Sheridan Ross PC. (57) ABSTRACT This invention discloses a talc additive for use as a filler in making paper products which is useful in preventing dusting or linting of paper. Also disclosed is a method of making the additive and using it in making paper. 14 Claims, No Drawings PLAINTIFFS EXHIBIT CAM-246 US 6,824,651 B2 12 TALC COMPOSITION AND USE IN PAPER PRODUCTS talc particles have a top size of less than about 1.5% and a particle size of about 5 microns. CROSS REFERENCE TO RELATED APPLICATION The present invention is also directed to a paper product which includes the talc composition of the present invention 5 and a method for making such a paper product. The method The present application is a continuation of U.S. patent application Ser. No. 10/005,722, filed Nov. 2, 2001, now includes adding the talc additive to a paper pulp and forming the paper pulp into a paper product. U.S. Pat. No. 6,565,646, entitled "TALC COMPOSITION AND USE IN PAPER PRODUCTS," which is incorporated 10 herein by this reference. DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a treated talc FIELD OF THE INVENTION composition, a method of making the same and use of the composition as a filler in making paper. The use of untreated This invention relates generally to the field of talc and talc in the paper making process is well known and has been more specifically relates to the use of a treated talc in paper 15 performed for many years. However, the use of untreated products. talc results in linting and dusting problems. Talc is more BACKGROUND OF THE INVENTION prone to linting or dusting than clay or other fillers due to talc's hydrophobicity and chemically inert planar surface. In the field of offset printing, the ink is first transferred Some paper making mills add a strengthened such as starch, from the printing plate to a blanket and then from the blanket 20 to the paper pulp mixture in order to improve the surface to paper. This offset mode is also used commercially for strength of the paper and overcome linting. However, the printing letterpress, called dry offset, or gravure, called addition of such a strengthener can affect the cost and the offset gravure. In offset printing, some picking of fibers or processing of the paper pulp. The process of the present fillers from the paper surface, called linting or dusting, is invention for making the treated talc composition includes normal due to some stiff, unfibrillated fibers that are not 25 processing talc to a talc particle size of less then 10 completely bonded to the sheet. Offset linting or dusting is micrometers in diameter, and imparting a cationic charge to a sheet surface phenomenon. However, these fibers and the surface of the talc particles. fillers because they are loosely bound to the paper can be Talc, in its unadulterated form, is a platy mineral, meaning transferred to the blanket, which will cause printing imper fections in resultant copies and inferior print copy. In 30 that talc will crystallize in a thin sheet and will tend to flake along cleavage planes. Talc can be processed as part of the addition, excessive linting or dusting will also lead to present invention by any suitable method. For example, one increased blanket maintenance. Thus, offset printers desire such method is by milling talc with an air classified mill to use paper which does not lint or dust excessively. ("ACM"). Here, the talc is dry and is hammered to achieve In the paper-making process, cellulosic fibers are softened 35 a desired particle size distribution curve. The talc particles with water before being processed into paper. Fillers such as are then screened to the desired median particle size. The clay, titanium dioxide, talc, and calcium carbonate, are ACM process produces more fractured talc particles than added to the papermaking process to improve paper prop delaminated talc particles. Another talc milling method is a erties such as opacity, brightness, and printability. Each filler fluidized energy method ("FEM"). Here, the talc is mixed is unique due to differences in physico-chemical and mor 40 into a slurry with water such that the talc is held in phological properties. One example of a substance which suspension and the talc particles are sorted to achieve the will reduce linting or dusting is clay. Titanium dioxide is an right particle size distribution curve. Although both methods excellent filler for opacity purposes due to is high refractive will produce talc that is suitable for use in the present index and particle size. Due to its hydrophobicity, talc is an invention, talc produced by ACM processing is preferred excellent pitch/stickie control. In addition, talc is an excel 45 because it produces a talc material with a lower top size (i.e., lent filler for purposes of improving machine drainage, sheet the quantity of particles retained on a 325-mesh screen or smoothness and printability. However, as a filler, talc does greater than 45 microns in diameter). The advantages of a not affiliate with the water-based cellulosic fibers as well as smaller top size are discussed in more detail below. certain other fillers that are more hydrophilic. Thus, a A cationic charge is imparted to the surface of the talc method of modifying talc's affinity to the cellulosic fibers of 50 particles. In this manner, it is believed that the ability of the the raw paper is needed. talc to adhere to the paper surface is improved to achieve SUMMARY OF THE INVENTION reduced dusting and/or linting during offset printing. In preferred embodiments, the cationic charge on the talc This invention discloses a sized and treated talc compo particles is retained during reslurrying, such as during a sition that is useful in preventing dusting or linting of paper 55 paper making process, and more preferably, the cationic when such talc is added to paper pulp during the paper charge on the talc particles is retained in the presence of making process. Also disclosed is a method of preparation of anionic trash (filtrate from a groundwood pulp). The step of the talc of the present invention and its use in making paper. imparting a cationic charge to the surface of the talc particles More particularly, the talc of the present invention is milled can be accomplished by mixing the talc particles with water to have a particle size of less than 10 micrometers and a 60 to create a slurry and, adding a cationic compound to the cationic charge to the surface of the talc particles. For slurry. The cationic compound can be any suitable cationic example, a cationic charge can be added to the particle by compound and in particular, can be cationic wet-end starch, mixing talc particles with water to create a slurry and, cationic wax-based emulsion, polydadmacs and carboxym adding a cationic compound to the slurry. In preferred ethylcellulose. embodiments, the cationic compound is selected from cat 65 In another aspect of the invention, the talc particles in the ionic wet-end starch, cationic wax-based emulsion, poly- talc composition have a top size of less than about 1.5%, dadmacs and carboxymethylcellulose. Also, preferably, the more preferably less than about 1.0%, and even more US 6,824,651 B2 34 preferably, less than about 0.5%. As noted above, the term top size refers to the weight percentage of the talc particles TABLE 1-continued in a given composition which are retained on a 325-mesh screen or are greater than 45 microns in diameter. In preferred embodiments, talc compositions in accordance 5 Compounds Supplier Functionality Mol. Charge pH Weight Density with the top size parameters of the present invention are ECCat 2010 Nalco Polydadmac High High prepared by milling in an air classified mill process. As demonstrated in the Examples, it has been found that use of talc compositions in accordance with the top size parameters of the present invention significantly reduces linting and 10 MicroCAT 300 Imprint DS Acrysol National Starch CibaGeigy Rohm & Modified Starch Paraffin Wax Polyurethane 6 (in solution) 5 6.0-8.0 dusting during offset printing. Finnfix or Haas Noviant Resin Sodium 6-8 (in As noted above, the process of the present invention Cellufix Carboxymethyl solution) includes processing talc to a talc particle size of less then 10 micrometers in diameter. In a further aspect of the present invention, the talc particles in the talc composition can have 15 a median particle size of about 7 microns, and in a further embodiment, can have a median particle size of about 5 Percol 292 Poly- CibaGeigy Mutek Cellulose Quaternary Acrylate Salt and Acrylamide Poly-diallyl- 3.8 (in solution) 6.0-8.0 High Low microns. It has been found that particle size of the talc composition has varying effects on its use as a filler in making paper. For example, as demonstrated in the 20 Examples, larger particle sizes, such as 10 microns and 7 microns, produce faster drainage of liquid during paper DADMAC PRP 5333 Chemtall (Pearl River dimethylammouniumch loride 2- hydroxyethylformaldehyde 1.0-2.0 production. It is believed this effect on drainage is achieved because the larger particle sizes open up the wet web during sheet forming allowing faster drainage. Alternatively, 25 smaller particle sizes, such as 5 microns provide porosity and sheet gloss benefits. PRP 4635 Hydrocol Polymers) Chemtall (Pearl River Polymers) Ciba- cationic polymer in solution Hydrated 4.0-8.0 10.0 The present invention is also directed to a method of making a paper product which includes adding a talc addi tive of the present invention to a paper pulp and forming the 30 2D7 Geigy Aluminum Silicate and Crystalline Quartz paper pulp into a paper product. In any given paper making process, various stages are set for additives to be mixed with the cellulose fibers that make up paper pulp. When talc is Hercobond Dowfax WP 310 Hercules Dow Polyether Polyol used as an additive to the paper, the talc is processed through *The PRP 5228 compound is a melamine-formaldehyde (MF) hydrochlo three stages before reaching the paper pulp. The talc is 35 ride polymer. prepared in a unit which is typically called a talc dispersion unit. The talc is mechanically sheared in the talc dispersion unit. From the talc dispersion unit, the talc enters into a Example 1 storage chest. From the storage chest, the talc is processed through a talc delivery line where it is finally added to the paper pulp. According to the present invention, the talc additive can be prepared by imparting a cationic charge to 40 A talc slurry was treated with cationic polymers, dried and re-slurried to simulate talc treatment in a paper-making plant. Three types of chemicals were used to modify the the surface of the talc particles at any of the three stages, surface of the talc, a surfactant, a dry strength resin and either at the talc dispersion unit, the talc storage chest, or in CMC. The talc slurry was prepared by dissolving 40 dry the talc delivery pipe. Further, the steps of adding a talc grams of talc in 180 grams of a water-cationic compound additive to a paper pulp and forming the pulp into a paper 45 mixture in a Dispermat mixer for 10 minutes. The water- product are conducted according to conventional processes. cationic compound mixture was prepared by mixing 20 grams of the active chemical in distilled water. In preparing The following examples are provided for the purposes of illustration and are not intended to limit the scope of the present invention. 50 the starch solution, a 4% slurry of starch and distilled water was cooked and stirred in a water bath maintained at 95 Celsius for 30 minutes. The talc's cationic charge was EXAMPFES determined before and after drying and after re-slurrying to determine cation charge retention. In order to determine the The compounds used in all of the experiments are delin eated in Table 1. 55 charge, immediately after preparation of the talc slurry, a 10 milliliter sample was titrated to its end-point with a 0.001N polydadmac solution using a Mutek Particle Charge Detec TABEE 1 tor ("PCD") tester. The amount of polydadmac titrant con sumed in the titration is multiplied by 100 in order to express Mol. Charge Compounds Supplier Functionality pH Weight Density the results in /req/L. The remainder of the talc slurry was filtered through a Buchner funnel using a #4 Whatman filter PRP 5228 Chemtall MF-based* 1.5-2.0 Low Low 60 pad. A 10 milliliter sample of the filtrate was then titrated (Pearl and measured using a Mutek PCD. The charge of the talc is River then determined by subtracting the unfiltered talc solution PRP 4440 Polymers) Chemtall (Pearl River Polymers) Polydadmac 4--8 Med Med charge from the filtered talc solution charge. The talc par ticles retained on the filter pad were dried overnight in an 65 oven maintained at 105 Celsius and reslurried in distilled water to 20 wt. % solids. The results of this test are contained in Table 2. 5 TABLE 2 US 6,824,651 B2 6 The results of the visual ranking of the uncalendered sheets are shown in Table 4. Cationic Charse (wea/Ll of Treated Talc PRP 5228 PRP 4440 ECCat 2010 5 TABLE 4 Talc Treatments at Reduced Dosages Run 1: Visual Total 330 >1500 >1500 Clay, % Talc, % Treatment Dosage, % Ranking Aqueous Talc Run 2: (After drying and reslurrying) Anionic 330 >1500 ND >1500 ND 10 28 22 0 None None 2 6* None None 6 22 ACM, 6 None None 4 22 6 Imprint DS 0.01 7 22 6 Imprint DS 0.05 3 Total Aqueous Talc -15 ND ND 1140 90 1050 Negative (Lost the Charge) ND ND 15 22 ACM, 6 Imprint DS 0.01 22 ACM, 6 Imprint DS 0.05 22 6 Imprint DS 0.03 22 ACM, 6 Imprint DS 0.03 22 6 Starch 0.04 2 2 2 2 8 ND = Not Determined 22 6 Starch 0.07 5 22 6 Starch 0.1 1 22 ACM, 6 Starch 0.04 3 As Table 2 shows, only the PRP 4440 treated talc held the 20 22 ACM, 6 Starch 0.07 3 cationic charge. The effects of pH to simulate the use of the 22 ACM, 6 Starch 0.1 8 treated talc in acid and neutral papermaking conditions and the presence of dissolved colloidal substances (anionic 22 ACM, 6 Aerosol 22 ACM, 6 CMC 0.5 0.5 4 1 trash) to simulate the papermaking process were also mea Note: sured. The cationic charge of the solutions were evaluated at 25 6* is 6 x m talc manufactured by the FEM process, as differentiated herein two pH levels, 4.5 and 7.0. The cationic charge of the talc from the ACM processed talc, 6. This same comment applies to Tables 5 was higher at pH of 4.5 than at a pH level of 7.0. Although and 6 herein below. not wishing to be bound by any particular theory, it is The results indicate that talc treated with either 0.10% believed that this result is due to the predominance of H+ starch and 0.50% CMC had the lowest Tinting propensity ions in a lower pH solution over the OH- ions in solution. 30 and appeared to outrank the clay control. The ACM talc In order to assess the effects of anionic trash, filtrate from treated with Imprint DS ranked the same as the clay control a groundwood pulp was introduced to the PRP 4440-treated in linting propensity. The results of this example demon talc solution. The introduction of the anionic trash changed strate that treating the talc before adding it to the paper the charge of the talc particles. reduces the linting of the paper. 35 Example 2 Example 4 In this example, four compounds were applied to talc to modify the surface and the treated Since only uncalendered sheets were tested to this point, supercalendered sheets were prepared and tested through an IGT Fluff Test. Supercalendering a hand sheet of paper is 40 conducted by passing the sheet between nips of heated rollers at high pressures a certain number of times. This Composition of Handsheet Visual Ranking process imparts smoothness for better printability and improves sheet gloss, an important factor in judging super- 22% Clay, 8% talc (control) 5 calendered sheets. In order to perform the IGT Fluff test, the 22% Clay,8% talc with 1% starch 22% Clay,8% talc with 2% starch 22% Clay,8% talc with 0.3% Imprint DS 3 1 45 sheets are passed through five (5) stages: the IGT inking 2 unit, the fluff tester, the printability tester, a visual ranking, 22% Clay,8% talc with 0.6% Dowfax WP-310 6 and a scanner. The IGT inking unit applies oil through an 22% Clay,8% talc with 0.5% Hercobond 4 IGT burette to one cylinder and ink to another cylinder. The cylinders are mounted on top of the transfer rollers. A fluff Treatment of talc with starch and Imprint DS showed a marked reduction in linting propensity. Treatment of talc with Hercobond also showed a reduction in linting propen sity. 50 tester is swiped over the entire cross-section of the sheet. The fiber and filler particles from the swiping will be transferred to the ink roller. The ink roller is then mounted to the tester and a strip is printed. The cleanliness of the strip is a measure of the linting propensity of the treatment. If Example 3 55 there are several treatments to be visually evaluated, the treatments are grouped in terms of "similar cleanliness" and The compounds tested in Example 2, and some additional subsequently graded with respect to each of the treatments compounds, were tested again at lower dosages. The same in the group. In addition, the strips can be passed through a process was followed in preparing the treated talc samples scanner, which will filter out the background and will count and handsheets were developed. As before, the uncalendered 60 the number of lint/dust particles, quantified by the respective handsheets were examined and ranked by visually assessing sizes of the particles. The output of the scanner will show the the printed strips for cleanliness, with 1 as the best and 10 total number of counts over the total area tested. as the worst. Supercalendered sheets were prepared and In addition, a vacuum drainage test was performed on the subjected to the IGT Fluff test (described in detail in supercalendered sheets. The vacuum drainage test tests the Example 4); however, the amount of fibers picked from the 65 drainage time through the sheet. In order to perform the sheets was insufficient to differentiate between the different vacuum drainage test, a 1 liter Erlenmeyer flask with a side treatments and, thus, no reliable data was able to be gleaned. adapter was attached to a vacuum gage. The vacuum gage US 6,824,651 B2 78 was operatively attached to a vacuum pump. A constant vacuum was applied and maintained throughout the test. A TABLE 7 500 milliliter slurry, with the additives, dosages, and shear of the talc particles simulating the process requirements, at headbox consistency was prepared using a Britt jar. The 5 Scanner Counts and Visual Ranking for Top (T) and Bottom (B) Side of ______________________Supercalendered Sheets______________________ slurry was poured into a Buchner funnel and the time for 400 Mean Mean milliliters of water to drain from the slurry was recorded. This time is called the drainage time, which is a measure of the free drainage in a paper making process. The results are Size Total Visual Size Total Visual Set Counts mm2 mm2 Rank Counts mm2 mm2 Rank No. (T) (T) (T) (T) (B) (B) (B) (B) shown in Table 5. 10 3-1 28 0.23 6.58 3 17 0.20 3.48 2 3-2 21 0.23 4.8 1 7 0.14 0.95 1 TABLE 5 3-3 45 0.22 9.84 7 3-4 27 0.28 7.47 5 15 0.25 3.68 12 0.28 3.34 7 5 Results of the Vacuum Drainage Test 3-5 20 0.27 5.37 6 3-6 15 0.20 3.02 2 4 0.24 0.96 8 0.21 1.66 4 3 Time Steady 15 3-8 20 0.24 4.81 4 20 0.10 2.01 6 Set Clay, Talc, Dosage, (400 Max. State No. % % Treatment % mL) Vacuum Vacuum The results of Table 7 demonstrate that the ACM 7 3-1 28 0 None 0 53 16.5 3-2 22 ACM, 6 None 0 40 16 3-3 22 ACM, 6 Imprint DS 0.01 39 16 3-4 22 ACM, 6 Imprint DS 0.03 Not Run 14.4 13.3 13.5 micrometer processed talc without treatment, the FEM pro cessed talc with treatment, the clay control, and the ACM 5 micrometer processed talc without treatment all performed similarly and superior to the remaining sets. These results 3-5 22 3-6 22 3-7 22 6 None 0 42 16.2 14.2 6 Imprint DS 0.01 40 16 13.5 6 Imprint DS 0.03 Not also indicate that the various treatments respond differently to the process of supercalendering. Run 25 The principles, preferred embodiments and modes of 3-8 22 ACM, (5 p i ) , 6 3-9 28 0 None None 0 0 46 16.3 14.2 51 16.4 14.4 operation of the present invention have been described in the foregoing specification. The invention which is intended to be protected herein should not, however, be construed as limited to the particular forms disclosed, as these are to be The results of Table 5 demonstrate that the 7 micrometer 30 regarded as illustrative rather than restrictive. Variations and talc produced the fastest drainage, followed by the 5 changes may be made by those skilled in the art without micrometer talc and clay. Imprint DS treatment also departing from the spirit of the present invention. improved drainage time. Accordingly, the foregoing best mode of carrying out the The supercalendered sheets were also tested for physical invention should be considered exemplary in nature and not properties like brightness, opacity, gloss, and porosity. The 35 as limiting to the scope and spirit of the invention as set forth results of these tests are shown in Table 6. in the appended claims. TABLE 6 Physical Properties of Supercalendered Sheets Set Clay Talc, No. % % Treatment Bright- OpaDosage ness city, % %% Gloss, % Poro COF COF sity Static Kinetic 3-1 28 0 None 3-2 22 ACM, None 0 0 66.8 92 19.8 65.6 93.2 20.3 98 0.418 0.332 108 0.400 0.302 3-3 22 ACM, Imprint 0.01 6 DS 3-4 22 ACM, Imprint 0.03 6 DS 3-5 22 6 None 0 3-6 22 6 Imprint 0.01 DS 3-7 22 6 Imprint 0.03 DS 3-8 22 ACM, None 0 (5 p i ) , 6 67.4 91.5 19.4 130 0.404 0.316 66.8 91.6 19.1 121 0.408 0.311 67.3 91.8 21.1 101 0.404 0.304 66.3 93.6 18.4 127 0.408 0.311 67.6 92.3 19.6 147 0.399 0.310 66.6 91.9 25.2 82 0.395 0.307 Sheets filled with untreated 5 fim ACM significantly We claim: improved gloss and reduced porosity. Thus, the results of the 1. A paper product having reduced linting and dusting testing show that using a particular size of talc and/or 60 having a modified talc filler wherein the talc filler comprises: treating the talc will result in lower linting/dusting problems, as well as improving other desirable paper properties. talc particles, wherein said talc particles have a diameter less than 10 micrometers, are prepared by milling in an The top side and bottom side of the supercalendered air classified mill process, and the surface of said talc sheets were tested with the scanner. The sets were visually particles is modified with a cationic compound such ranked with respect to the other sets, with the best set getting 65 that the talc particles are less hydrophobic and have a a rank of 1 and the worst set getting a rank of 7. The results cationic charge to increase the affinity of the talc of the scanner testing are shown in Table 7. particles to paper fibers. US 6,824,651 B2 9 10 2. The paper product, as claimed in claim 1, wherein said talc particles are less hydrophobic and have a cationic charge surface of said talc particles are prepared by a process of: to increase the affinity of the talc particles to paper fibers, mixing the talc particles with water to create a slurry; and, and wherein said talc particles are prepared by milling in an adding a cationic compound to the slurry. air classified mill process. 3. The paper product, as claimed in claim 2, wherein said 5 9. The process, as claimed in claim 8, wherein said surface cationic compound is selected from the group consisting of of said talc particles is modified by: cationic wet-end starch, cationic wax-based emulsion, poly- mixing the talc particles with water to create a slurry; and, dadmacs and carboxymethylcellulose. adding a cationic compound to the slurry. 4. The paper product, as claimed in claim 1, wherein said 10. The process, as claimed in claim 9, wherein said talc particles have a top size of less than about 1.5%. 10 cationic compound is selected from the group consisting of 5. The paper product, as claimed in claim 1, wherein said cationic wet-end starch, cationic wax-based emulsion, poly- talc particles have a top size of less than about 1.0%. dadmacs and carboxymethylcellulose. 6. The paper product, as claimed in claim 1, wherein said 11. The process, as claimed in claim 8, wherein said talc talc particles have a top size of less than about 0.5%. particles have a top size of less than about 1.5%. 7. The paper product, as claimed in claim 1, wherein said 15 12. The process, as claimed in claim 8, wherein said talc talc particles have a particle size of about 5 microns. particles have a top size of less than about 1.0%. 8. A process for making a paper product having reduced 13. The process, as claimed in claim 8, wherein said talc linting and dusting, comprising adding a talc additive to a particles have a top size of less than about 0.5%. paper pulp and forming the paper pulp into a paper product, 14. The process, as claimed in claim 8, wherein said talc wherein said talc additive comprises talc particles having a 20 particles have a particle size of about 5 microns. size of less than 10 micrometers; and the surface of said talc particles is modified with a cationic compound such that the UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO. : 6,824,651 B2 DATED : November 30, 2004 INVENTOR(S) : Lasmarias et al. Page 1 of 1 It is certified that error appears in the above-identified patent and that said Letters Patent is hereby corrected as shown below: Column 5, Line 38, delete "and the treated" change to - . - has been inserted. Column 6, Lines 64-64, "The vacuum drainage test tests the drainage time through the sheet." has been deleted. Signed and Sealed this Tenth Day of May, 2005 JON W. DUDAS Director o f the United States Patent and Trademark Office