Document EqzEG6ny9w2R0Mj1QD3RgkzJg
(12) United States Patent
Lasmarias et al.
US006824651B2
(10) Patent N0.: 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); Shripa] Shanna, 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. N0.: 10/404,786 (22) Filed: Mar. 31, 2003
(65) Prior Publication Data
US 2003/0205344 A1 Nov. 6, 2003
Related US. Application Data
(63) Continuation of application No. 10/005,722, ?led on Nov. 2, 2001, now Pat. No. 6,565,646.
(51) Int. Cl.7 ....................... .. D21H 17/68; D21H 17/63 (52) US. 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 1/1985 Zunker ..................... .. 428/403
4,710,270 A 12/1987 Sunden et al.
.... .. 162/175
5,244,542 A
9/1993 Bown et al. .... ..
162/164.3
5,454,864 A * 10/1995 Whalen--ShaW ----------- -- 106/416
5,458,679 A * 10/1995 Fairchild .................. .. 106/465
5,492,560 A 2/1996 Fairchild 5,516,405 A 5/1996 De Witt
.. 106/204.01 162/164.1
5,972,100 A 10/1999 Dumas .................. .. 106/501.1
6,033,524 A 3/2000 PrusZynski et al. ....... .. 162/165
6,565,646 B1 * 5/2003 Lasmarias et al. ........ .. 106/801
2003/0096143 A1 * 5/2003 Lasmarias et al.
428/702
2004/0065419 A1 * 4/2004 Lasmarias et al. ........... .. 162/5
FOREIGN PATENT DOCUMENTS
W0
WO 01/86067
11/2001
OTHER PUBLICATIONS
R. A. Gil in "Applications of Wet--End Paper Chemistry: Fillers for papermaking" 1995, Blackie Academic & Pro feesional, 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 tale additive for use as a ?ller 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
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.
The present invention is also directed to a paper product
CROSS REFERENCE TO RELATED APPLICATION
Which includes the talc composition of the present invention and a method for making such a paper product. The method
The present application is a continuation of US. patent application Ser. No. 10/005,722, ?led Nov. 2, 2001, now
includes adding the talc additive to a paper pulp and forming the paper pulp into a paper product.
US. 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 ?ller in making paper. The use of untreated
This invention relates generally to the ?eld of talc and talc in the paper making process is Well knoWn and has been
more speci?cally relates to the use of a treated talc in paper
products.
15
performed for many years. HoWever, the use of untreated talc results in linting and dusting problems. Talc is more
BACKGROUND OF THE INVENTION
prone to linting or dusting than clay or other ?llers due to
talc's hydrophobicity and chemically inert planar surface.
In the ?eld of offset printing, the ink is ?rst transferred Some paper making mills add a strengthener, 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 ?bers or processing of the paper pulp. The process of the present
?llers from the paper surface, called linting or dusting, is invention for making the treated talc composition includes normal due to some stiff, un?brillated ?bers 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 ?bers and the surface of the talc particles.
?llers 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 ?ake 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 classi?ed 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 ?bers 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 ?ller ?uidiZed 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 ?ller 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 ?ller for purposes of improving machine drainage, sheet the quantity of particles retained on a 325-mesh screen or
smoothness and printability. HoWever, as a ?ller, talc does greater than 45 microns in diameter). The advantages of a
not af?liate With the Water-based cellulosic ?bers as Well as smaller top siZe are discussed in more detail beloW.
certain other ?llers that are more hydrophilic. Thus, a
A cationic charge is imparted to the surface of the talc
method of modifying talc's af?nity to the cellulosic ?bers 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 making process. Also disclosed is a method of preparation of the talc of the present invention and its use in making paper. More particularly, the talc of the present invention is milled
charge on the talc particles is retained in the presence of anionic trash (?ltrate from a groundWood pulp). The step of imparting a cationic charge to the surface of the talc particles 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 mixing talc particles With Water to create a slurry and, adding a cationic compound to the slurry. In preferred
compound and in particular, can be cationic Wet-end starch,
cationic Wax-based emulsion, polydadmacs and carboxym
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
Mol. Charge
Compounds Supplier Functionality 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 classi?ed 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 signi?cantly reduces linting and 10
MicroCAT 300
Imprint DS
Acrysol
National
Starch Ciba-
Geigy
Rohm &
Modi?ed Starch
Paraf?n Wax
Polyurethane
6 (in solution)
5
6.0-8.0
dusting during offset printing.
Haas Finn?x or Noviant
Resin Sodium
6-8 (in
As noted above, the process of the present invention 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
Cellu?x Percol 292
Ciba-
Geigy
Carboxymethyl
Cellulose
Quaternary
Acrylate Salt
and
Acrylamide
solution)
3.8 (in
solution)
High
LoW
embodiment, can have a median particle siZe of about 5 microns. It has been found that particle siZe of the talc
composition has varying effects on its use as a ?ller 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
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 bene?ts.
PolyDADMAC
PRP 5333
PRP 4635
Hydrocol
Mutek
Chemtall
(Pearl
River
Polymers)
Chemtall
(Pearl
River
Polymers)
Ciba-
Poly-diallyldimethyl
ammouniumch loride 2-
hydroxyethyl
formaldehyde
cationic
polymer in
solution
Hydrated
6.0-8.0
1.0-2.0 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 ?bers that make up paper pulp. When talc is
Hercobond Hercules DoWfax WP DoW
310
Polyether Polyol
used as an additive to the paper, the talc is processed through *The PRP 5228 compound is a melamine-formaldehyde
three stages before reaching the paper pulp. The talc is 35 ride polymer. prepared in a unit Which is typically called a talc dispersion
hydrochlo
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 ?nally added to the
paper pulp. According to the present invention, the talc additive can be prepared by imparting a cationic charge to
40
Atalc 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 the starch solution, a 4% slurry of starch and distilled Water
illustration and are not intended to limit the scope of the
present invention.
Was cooked and stirred in a Water bath maintained at 95
50 Celsius for 30 minutes. The talc's cationic charge Was
EXAMPLES
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 charge, immediately after preparation of the talc slurry, a 10
eated in Table 1.
milliliter sample Was titrated to its end-point With a 0.001N 55 polydadmac solution using a Mutek Particle Charge Detec
TABLE 1
tor ("PCD") tester. The amount of polydadmac titrant con sumed in the titration is multiplied by 100 in order to express
Compounds Supplier Functionality
Mol. Charge
pH Weight Density
the results in yeq/L. The remainder of the talc slurry Was ?ltered through a Buchner funnel using a #4 Whatman ?lter
PRP 5228 Chemtall MF-based" 1.5-2.0 LoW LoW 60 pad. A 10 milliliter sample of the ?ltrate Was then titrated (Pearl and measured using a Mutek PCD. The charge of the talc is
River then determined by subtracting the un?ltered talc solution
Polymers)
charge from the ?ltered talc solution charge. The talc par
PRP 4440 Chemtall Polydadmac 4-8 Med Med
ticles retained on the ?lter pad Were dried overnight in an
(Pearl
River
65 oven maintained at 105 Celsius and reslurried in distilled
Polymers)
Water to 20 Wt. % solids. The results of this test are contained
in Table 2.
TABLE 2
US 6,824,651 B2 6
The results of the visual ranking of the uncalendered sheets are shoWn in Table 4.
Cationic Charge geg/L of Treated Talc
TABLE 4
PRP 522s PRP 4440
ECCat 2010
Talc Treatments at Reduced Dosages
Run 1:
Total Aqueous Talc Run 2:
(After drying and
reslurrying)
330 Anionic
330
>1500 >1500
ND
>1500 >1500
ND
Clay, %
Visual
Talc, % Treatment Dosage, % Ranking
28 10
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 1140 Negative
22
ACM, 6 Imprint DS
0.01
2
(Lost the Charge) 15
22
ACM, 6 Imprint DS
0.05
22
6
Imprint DS
0.03
2 2
ND 90 ND 1050
ND ND
22
ACM, 6 Imprint DS
0.03
2
22 6 Starch 0.04 8
ND = Not Determined
22 6 Starch 0.07 5
22
6 Starch 0.1
1
As Table 2 shows, only the PRP 4440 treated talc held the 20 cationic charge. The effects of pH to simulate the use of the
treated talc in acid and neutral papermaking conditions and
the presence of dissolved colloidal substances (anionic
22
ACM, 6
Starch
0.04
22
ACM, 6
Starch
0.07
22
ACM, 6
Starch
0.1
22
ACM, 6
Acrosol
0.5
22
ACM, 6
CMC
0.5
3 3 8 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 ,urn 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, ?ltrate 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.
Example 2 35 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
22% Clay, 8% talc (control) 22% Clay, 8% talc With 1% starch 22% Clay, 8% talc With 2% starch 22% Clay, 8% talc With 0.3% Imprint DS 22% Clay, 8% talc With 0.6% DoWfax WP-310 22% Clay, 8% talc With 0.5% Hercobond
Visual Ranking
process imparts smoothness for better printability and improves sheet gloss, an important factor in judging super calendered sheets. In order to perform the IGT Fluff test, the 45 sheets are passed through ?ve (5) stages: the IGT inking unit, the ?uff tester, the printability tester, a visual ranking, and a scanner. The IGT inking unit applies oil through an IGT burette to one cylinder and ink to another cylinder. The
cylinders are mounted on top of the transfer rollers. A ?uff
Treatment of talc With starch and Imprint DS shoWed a marked reduction in linting propensity. Treatment of talc
50
tester is sWiped over the entire cross-section of the sheet. The ?ber and ?ller particles from the sWiping Will be
With Hercobond also shoWed a reduction in linting propen
transferred to the ink roller. The ink roller is then mounted
sity. 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 ?lter out the background and Will count
and handsheets Were developed. As before, the uncalendered 60 the number of lint/dust particles, quanti?ed 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 ?bers picked from the 65 drainage time through the sheet. In order to perform the
sheets Was insuf?cient to differentiate betWeen the different vacuum drainage test, a 1 liter Erlenmeyer ?ask 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
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
slurry Was poured into a Buchner funnel and the time for 400
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
TABLE 7
Scanner Counts and Visual Ranking for Top (T) and Bottom (B) Side of Supercalendered Sheets
Mean Mean
Size; Totazl Visual
Size; Totazl Visual
get Counts mm In? Rank cognts In]? In]? R3151`
0' (D (T) ( ) (D ( ) ( ) ( ) ( )
shoWn in Table 5.
TABLE 5 _
Results of the Vacuum Drainage Test
10 3-1 28 0.23 6.58 3
3-2 21 0.23 4.8
1
3-3 45 0.22 9.84 7 3-4 27 0.28 7.47 5
3-5 20 0.27 5.37 6 3_6 15 020 302 2
17 0.20 3.48 7 0.14 0.95 15 0.25 3.68 12 0.28 3.34
4 0.24 0.96 8 021 L66
2 1 7 5
4 3
_
Time
15 3-8
Steady
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
5; Acid 6 gene 8 i3 125 1;; micrometer processed talc Without treatment, the FEM pro
' , one
3_3 22 ACM, 6 Imprint D5 001 39 16
..
135 20 cessed talc With treatment, the clay control, and the ACM 5
3_4 22 ACM, 6 Imprint D5 003 Not Run
micrometer processed talc Without'treatment all performed similarly and superior to the remaining sets. These results
2'2 g I Nf'neDS 801 :3 122
also indicate that the various treatments respond differently
--
3_7 22
mprint
.
6 Imprint D5 003 Not
.-
to the process of supercalendering.
Run 25 The principles, preferred embodiments and modes of
3'8 22 (lag/L6 None 0
46 16'3 14'2
operation of the present invention have been described in the
3_9 28 0' None 0
51 164 144
foregoing speci?cation. 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 demohstrate that the 7 hherohleter 30 regarded as illustrative rather than restrictive. Variations and
tale Produced the fastest dralhage followed by the 5 changes may be made by those skilled in the art Without
hheretheter tale ahd elay- hhpnht DS treatment also departing from the spirit of the present invention.
hhproved dralhage thhe-
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 %
%
Bright- Opa
Treat- Dosage ness city, Gloss, Poro- COF COF
merit %
% % % sity Static Kinetic
3-1 28 0 None 0
3-2 22 ACM, None 0
6
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 M), 6
66.8 92 19.8 98 0.418 0.332 65.6 93.2 20.3 108 0.400 0.302
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 ?lled With untreated 5 pm ACM signi?cantly
We claim:
improved gloss and reduced porosity. Thus, the results of the 60 1. A paper product having reduced linting and dusting
testing shoW that using a particular siZe of talc and/or having a modi?ed talc ?ller Wherein the talc ?ller comprises:
treatlng thqtalc wlllfesllltln 10Wef11I1t1I1g/d1lSt1hg Phoblems, talc particles, Wherein said talc particles have a diameter
as Well as improving other desirable paper properties.
less than 10 micrometers, are prepared by milling in an
The top side and bottom side of the supercalendered
air classi?ed mill process, and the surface of said talc
sheets Were tested With the scanner. The sets Were visually
particles is modi?ed 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 af?nity of the talc
of the scanner testing are shoWn in Table 7.
particles to paper ?bers.
US 6,824,651 B2
10
2. The paper product, as claimed in claim 1, wherein said surface of said talc particles are prepared by a process of:
mixing the talc particles With Water to create a slurry; and,
adding a cationic compound to the slurry. 3. The paper product, as claimed in claim 2, Wherein said cationic compound is selected from the group consisting of cationic Wet-end starch, cationic Wax-based emulsion, poly dadmacs and carboXymethylcellulose.
talc particles are less hydrophobic and have a cationic charge to increase the af?nity of the talc particles to paper ?bers, and Wherein said talc particles are prepared by milling in an air classi?ed mill process.
9. The process, as claimed in claim 8, Wherein said surface of said talc particles is modi?ed by:
miXing the talc particles With Water to create a slurry; and,
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 particles have a particle siZe of about 5 microns.
siZe of less than 10 micrometers; and the surface of said talc particles is modi?ed 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) : Lasniarias et at.
Page 1 of 1
It is certified that error appears in the above-identi?ed 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
.. W4)...
JON W. DUDAS Director ofthe United States Patent and Trademark O?`ice