US4445970A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High mineral composite fine paper
Assignee: Willamette Industries Inc
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Filing: 1981-06-01
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Granted: 1984-05-01
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Expires: 2001-06-01
Abstract
Abstract Composite fine paper suitable for offset and gravure printing at high speeds and containing over 30% filler up to 70% filler for basis weights of 30-150 lbs/3300 ft 2 , is produced on a high speed paper-making machine from a furnish containing large quantities of filler, preferably a mixture of clay and talc, and including 3-7% of an ionic latex which is selected to provide good retention and good strength without leaving a residue on the screen.
Inventors
- 👤 Richard L. Post
- 👤 Robert G. Fort
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 03:05
CPC Classifications
D; D21; D21F; D21F11/00; B; B41; B41M; B41M1/00; B41M1/26; B41M1/36; D21H; D21H17/00; D21H17/20; D21H17/33; D21H17/34; D21H17/41; D21H17/44; D21H17/45; D21H17/455; D21H17/62; D21H17/63; D21H17/67; D21H17/68
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
200 words
A method of manufacturing fine paper containing mineral filler at a high speed comprising: preparing an acidic paper furnish including paper-making fibers; an amount sufficient of mineral filler to retain internally in the fine paper web formed of 30-70% mineral filler, and wherein said mineral filler is system compatible; at least one retention aid agent which comprises a water soluble cationic polymer; and 3-7%, based on the dry furnish, of a cationic latex or amphoteric latex which is cationic at acid pH, said cationic or amphoteric latex being selected from latices which provide good mineral filler retention without substantial reduction in strength, which have a charge opposite to and less than the sum of the charges of the other ingredients of said furnish, and which precipitate on the fibers and fillers to exhaustion or near exhaustion; forming a wet paper web from said furnish such as to produce fine paper of thickness 1.5-15 mils and weight 30-150 lbs/3300 ft 2 containing internally greater than 30% mineral filler up to 70% mineral filler, and having tensile and Z-directional strength sufficient to withstand high-speed offset or gravure printing; drying said web; and surface treating the dried web to improve the printability thereof.
Claim 2
Independent Claim
200 words
A method of manufacturing fine paper containing mineral filler at a high speed comprising: preparing an acidic paper furnish including paper-making fibers; an amount sufficient of mineral filler to retain internally in the fine paper web formed of 30-70% mineral filler, and wherein said mineral filler is system compatible; at least one retention aid agent which comprises a water soluble cationic polymer; and 3-7%, based on the dry furnish, of a cationic latex or amphoteric latex which is cationic at acid pH, said cationic or amphoteric latex being selected from latices which provide good mineral filler retention without substantial reduction in strength, which have a charge opposite to and less than the sum of the charges of the other ingredients of said furnish, and which precipitate on the fibers and fillers to exhaustion or near exhaustion; forming a wet paper web from said furnish such as to produce fine paper of thickness 1.5-15 mils and weight 30-150 lbs/3300 ft 2 containing internally greater than 30% mineral filler up to 70% mineral filler, and having tensile and Z-directional strength sufficient to withstand high-speed offset or gravure printing; drying said web; and surface treating the dried web to improve the printability thereof.
Claim 3
Dependent Claim
18 words
A method according to claim 1 wherein said wet paper web is formed on a Fourdrinier paper machine.
Claim 4
Dependent Claim
12 words
A method according to claim 1 wherein said furnish also comprises alum.
Claim 5
Dependent Claim
32 words
A method according to claim 3 wherein said furnish comprises approximately 5-10 lbs of rosin size per ton of dry furnish and sufficient of said alum to provide a pH of 4.0-5.0.
Claim 6
Dependent Claim
22 words
A method according to claim 1 wherein said paper-making fibers are cellulose fibers and comprise 50-100% hardwood kraft and 0-50% softwood kraft.
Claim 7
Dependent Claim
19 words
A method according to claim 5 wherein said cellulose fibers comprise approximately 25% softwood kraft and 75% hardwood kraft.
Claim 8
Dependent Claim
20 words
A method according to claim 1 wherein said latex is selected from styrene-butadiene latex, acrylic latex, and polyvinyl acetate latex.
Claim 9
Dependent Claim
22 words
A method according to claim 1 wherein said latex is amphoteric at a pH of 7.0, and is cationic under acidic conditions.
Claim 10
Dependent Claim
34 words
A method according to claim 1 wherein said retention aid agent comprises two said cationic polymers, each of which is added to the furnish at a different stage during the preparation of said furnish.
Claim 11
Dependent Claim
29 words
A method according to claim 1 wherein said mineral filler is selected from the group consisting of kaolin clay, talc, titanium dioxide, aluminum hydrate, hydrated silica and mixtures thereof.
Claim 12
Dependent Claim
17 words
A method according to claim 1 wherein said filler comprises a mixture of talc and kaolin clay.
Claim 13
Dependent Claim
25 words
A method according to claim 11 wherein said mixture of kaolin clay and talc is in the ratio of 95:5 to 5:95 parts by weight.
Claim 14
Dependent Claim
16 words
A method according to claim 11 wherein said mixture comprises 5-75% talc and 95-25% kaolin clay.
Claim 15
Dependent Claim
25 words
A method according to claim 10 or 11 or 12 or 13 wherein the particle size of said filler ranges from 0.5 to 15 microns.
Claim 16
Dependent Claim
59 words
A method according to claim 1 wherein said preparation of the paper furnish comprises mixing hardwood pulp, broke, softwood pulp and filler, feeding the resultant slurry to a funnel where latex and rosin are added, passing the resultant mixture into a machine chest, adding alum and a first cationic polymer, adding dilution water, and adding a second cationic polymer.
Claim 17
Dependent Claim
28 words
A method according to claim 15 wherein each of said cationic polymers is added in an amount of about 0.25 to 3 lbs per ton of dry furnish.
Claim 18
Dependent Claim
43 words
A method according to claim 1 wherein said surface treating of the dried web comprises surface sizing of the dried web comprising coating the dried web with starch size at the rate of 30-200 lbs of said starch size per ton of paper.
Claim 19
Dependent Claim
47 words
Method according to claim 1 wherein said surface treating of the dried web comprises coating the dried web with starch, polyvinyl alcohol, styrene-butadiene latex, polyvinyl acetate latex, clay, titanium, calcium carbonate, talc, or any combination thereof to improve the surface of printing or other functional end use.
Claim 20
Dependent Claim
16 words
Method according to claim 1 wherein the thickness of the said paper ranges from 2.0-8.0 mils.
Claim 21
Dependent Claim
39 words
Method according to claim 1 wherein said paper-making fibers are cellulose fibers comprised of bleached and unbleached hardwood and softwood fibers pulped by various pulping methods, i.e. groundwood, sulfite and kraft pulping including thermomechanical, semichemical and soda pulping process.
Claim 22
Dependent Claim
13 words
Method according to claim 1 wherein said paper-making fibers contain 1-100% synthetic fibers.
Claim 23
Dependent Claim
21 words
A method according to claim 1 wherein said fine paper produced has a filler content no greater than 50% by weight.
Claim 24
Dependent Claim
77 words
Fine paper of 2-13 mils thickness produced according to the method of claim 1 and containing about 40% mineral filler for a basis weight of about 40 lbs/3300 ft 2 , about 50% mineral filler for a basis weight of about 50 lbs/3300 ft 2 , about 60% mineral filler for a basis weight of about 60 lbs/3300 ft 2 , or about 70% mineral filler for a basis weight of about 70-150 lbs/3300 ft 2 .
Claim 25
Dependent Claim
38 words
Fine paper of 3-10 mils thickness having sufficient tensile and Z-directional strength to withstand high-speed offset or gravure printing, of weight 30-150 lbs/3300 ft 2 , containing 30-70% mineral filler, produced according to the method of claim 1.
Claim 26
Dependent Claim
38 words
Fine paper of 3-10 mils thickness having sufficient tensile and Z-directional strength to withstand high-speed offset or gravure printing, of weight 30-150 lbs/3300 ft 2 , containing 30-70% mineral filler, produced according to the method of claim 14.
Claim 27
Dependent Claim
16 words
Fine paper according to claim 23 having a filler content no greater than 50% by weight.
Claim 28
Dependent Claim
21 words
Fine paper according to claim 25 or 26 wherein said filler has a particle size no greater than about 325 mesh.
Claim 29
Dependent Claim
93 words
Fine paper of 2-13 mils thickness produced according to the method of claim 3 and containing about 40% mineral filler for a basis weight of about 40 lbs/3300 ft 2 , about 50% mineral filler for a basis weight of about 50 lbs/3300 ft 2 , about 60% mineral filler for a basis weight of about 60 lbs/3300 ft 2 , or about 70% mineral filler for a basis weight of about 70-150 lbs/3300 ft 2 , said fine paper having sufficient tensile and Z-directional strength to withstand high-speed offset or gravure printing.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-05-01 | 1987-10-31 | 1988-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-01 | 1991-10-31 | 1992-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-01 | 1995-10-31 | 1996-05-01 | $7700.00 | Window Closed / Lapsed |