Source: https://patents.google.com/patent/US4051276?oq=flatulence
Timestamp: 2018-02-21 21:42:44
Document Index: 56104093

Matched Legal Cases: ['art            118', 'art            465', 'art            604', 'art            118', 'art            465', 'art            604']

US4051276A - Method of deacidifying paper - Google Patents
Method of deacidifying paper
US4051276A
US4051276A US05660286 US66028676A US4051276A US 4051276 A US4051276 A US 4051276A US 05660286 US05660286 US 05660286 US 66028676 A US66028676 A US 66028676A US 4051276 A US4051276 A US 4051276A
US05660286
The important criteria for the organo-metallic compound is: (1) that it be relatively volatile, whether at atmospheric pressure or under reduced pressure, at temperatures up to about 150° C.; (2) that it not cause discoloration of the paper, and (3) that it not interact significantly to damage inks or materials usually found in books, (4) that it be readily reactive with acids, and preferably also with alcohols and the hydroxyl groups of cellulose.
(C.sub.2 H.sub.5)2 Zn + H.sub.2 O → (C.sub.2 H.sub.5)ZnOH + C.sub.2 H.sub.6 ↑
(c.sub.2 h.sub.5) znOH + H.sub.2 O → C.sub.2 H.sub.6 ↑ + Zn(OH).sub.2
this deposits the alkaline Zn(OH)2 in the paper.
Cell OH + (C.sub.2 H.sub.5) Zn → Cell OZn(C.sub.2 H.sub.5) + C.sub.2 H.sub.6 ↑
Cell O Zn--(C.sub.2 H.sub.5) + 2H.sub.2 O → Cell OH + Zn(OH).sub.2 + C.sub.2 H.sub.6 ↑
Cell CHO + (C.sub.2 H.sub.5).sub.2 Zn → Cell CH.sub.2 OH + Zn(OH).sub.2 + C.sub.2 H.sub.6
[cell]2 C═O + (C2 H5)2 Zn → [cell]2 ═CHOH + Zn(OH)2 +C2 H6
these reactions change cellulose from an unstable to a stable material, one showing good color retention.
AlR.sub.3 + 3HX → AlX.sub.3 + 3RH
The limits on the process are set by the physical properties of the materials involved. Thus, the maximum temperature used must be below the decomposition temperatures of the components of the books and papers and the decomposition temperature of the organometallic treating agent. An exposure of paper to temperatures above 150° C will result in significant deterioration of the paper in a few hours so this in general represents the upper limit of temperature. However, most organometallics used in this process have decomposition temperatures lower than this, which will effectively lower the upper operating limit to that of the decomposition temperature of the organometallic treating agent. In the case of diethylzinc, this decomposition begins at about 120° C, or slightly below its boiling point at atmospheric pressure.
The preferred upper operating limit is about 80° C which will provide an adequate margin of safety.
The material to be deacidified is weighed and placed in the chamber and heated to 60° C while evacuating to a pressure of less than 0.1 mm of mercury absolute. When the material hs dried to the point that the pressure remains steady for 20 minutes with the pump shut off (this also insures against leaks) the treatment is begun. Any moisture in the books and papers being treated in volatized under the temperature and pressure utilized, otherwise it would inhibit the penetration of the agent, causing reaction to take place in the outer sheets and edges of the objects being treated leaving the center unchanged in acidity or inadequately treated unless the treatment is prolonged and a large excess of the treating agent is employed. In any case, such excess moisture leads to uneven distribution of the alkaline reserve imparted to the paper by the treatment, and is thus undesirable. It is advantageous to heat the books and papers slightly to prevent condensation.
Table II shows the effect of the treatment on accelerated aging in the dry oven at 100° C. The newsprint apparently was not improved by the treatment when tested in the dry oven, but the Mead Bond and the offset paper show substantial gains in fold retention as a result of the treatment. The brightness was not affected by the treatment at this level of impregnation. Higher levels of impregnation do result in improved brightness.
TABLE II__________________________________________________________________________Diethyl Zinc Vapor Phase Treatment of PaperEffect on Accelerated Aging CharacteristicsDry Oven Aging-100° C            Characteristics     Equivalent            MIT Folding     Years  Endurance*                      BrightnessPaper     Aging  Control                 Treated                      Control                           Treated__________________________________________________________________________Newsprint Zero-Start            118  135  54   53     67 Years            2.3  3.2  --   --     117 Years            1.5  1.7  40   41Mead Bond Zero-Start            465  476  84   83     67 Years            64   274  77   77     117 Years            25   92   75   76Offset Gov't     Zero-Start            604  652  76   75Printing Office     67 Years            207  432  71   71JCP-A60   117 Years            20   252  70   70__________________________________________________________________________ *1/2 Kg load.
TABLE III__________________________________________________________________________Diethyl Zinc Vapor Phase Treatment of PaperEffect on Accelerated Aging CharacteristicsHumid Oven Aging-90° C, 50% R. H.            Characteristics     Equivalent            MIT Folding     Years  Endurance*                      BrightnessPaper     Aging  Control                 Treated                      Control                           Treated__________________________________________________________________________Newsprint Zero-Start            118  135  54   53     67 Years            3.5  60   41   45     117 Years            0.6  36   36   41Mead Bond Zero-Start            465  476  84   83     67 Years            92   134  77   78     117 Years            54   122  75   74Offset Gov't     Zero-Start            604  652  76   75Printing Office     67 Years            240  441  72   69JCP-A60   117 Years            145  315  70   68__________________________________________________________________________ *1/2 Kg load.
16 sheets of a 60-lb bond paper and 16 sheets of newsprint, 81/2 × 11 inches, were placed in a treating chamber as described above and dried by heating to 68° C, while evacuating to a pressure of 0.1 Torr. After three hours, the pressure stabilized at 0.1 Torr and this pressure held for twenty minutes with the pump shut off. Then 20 ml of a 15% solution of diethylzinc in octane was injected into the treating chamber. The pressure rose immediately to about 90 Torr and reflux was noted from the condenser at the top of the chamber. Treatment was continued for 41/2 hours at a pressure of 88-90 Torr and a temperature of 68-70° C. At the end of this period, the heat was shut off and the apparatus cooled to about 60° C, at which time the apparatus was returned to atmospheric pressure with dry nitrogen, and 4 ml of methanol was injected to destroy any excess diethylzinc. After 10 minutes, the reactor was opened and the treated sheets removed. The results are shown in Table IV.
Accelerated aging tests in the dry oven at 100° C indicated that the life of the bond paper was more than doubled by the treatment. As mentioned previously, little change in the estimated life of the newsprint was noted in the dry oven tests as a result of the treatment. However, in the humid oven tests, at 90° C and 50% R. H., the fold endurance retention of the newsprint was increased four times by the treatment (from 100 years to 430 years). The bond paper again showed a doubling of its retention of folding endurance under the humid aging conditions as a result of the treatment (242 years to 475 years).
A book segment measuring 19 cm × 7.5 cm × 4 cm thick with pages having pH of 5.0 to 5.6 and acidity of about 40 meq/Kg was placed in the treating chamber in a closed position. The weight of the book was 462 g. before drying. The book was dried in the treatment chamber for 4 hours at 65° C while evacuating to a pressure of 0.07 Torr. At this time, no further water could be drawn off from the book and the pressure stabilized. Then 65 ml of a 28% solution of diethylzinc in octane was injected, raising the pressure to 85 Torr. Slow reflux of the treating solution was maintained for 51/2 hours keeping the temperature at 66°-69° C and the pressure at 85-86 Torr. At the end of this time, the reactor was cooled and backpressured with dry nitrogen to atmospheric pressure. The reactor was then purged with slightly damp nitrogen for 2 hours to destroy excess diethylzinc. The reactor was then opened and the book removed. Indicator tests with a pH pencil taken on pages 2, 59, 130, 451, 670, and 951 (last page) showed that the book was completely deacidified, with a slightly alkaline pH from the edge of the page clear to the spine. Tests of three pages taken from the front, center, and 3/4 through the book showed pH measurements of 7.38, 7.35, and 7.35 respectively and zinc oxide contents of 0.36%, 0.38% and 0.39% respectively showing the excellent penetration and even distribution obtained. The brightness of the pages averaged 65.8 for the pages of the book before treatment and 64.6 for the pages after treatment, a negligible change for such a treatment. There was no change in folding endurance of the sheets as a result of the treatment. Since this book still had its covers, and with tightly closed, it is obvious that the penetration and neutralization is extremely effective and will not require the books to be opened for treatment.
16 sheets of newsprint 81/2 × 11 and 16 similar sheets of offset paper JCP-A60 obtained from the Government Printing Office, weighing 61 and 66.6 g respectively before drying were carefully dried in a vacuum oven. After drying the sheets weighed 47.2 g (newsprint) and 62.9 g (offset).
The dried sheets of the two papers were placed in the treatment chamber in a single pile, and the chamber was heated to 60° C internal temperature while reducing the pressure in the chamber to 0.1 Torr. After 2 hours, to allow the paper to come to temperature equilibrium with the chamber, the pressure in the chamber was raised to 85 Torr with dry nitrogen, and 20 ml of a 25% solution of diethylzinc in octane was added to the bottom of the chamber, avoiding contact with the paper. Under these conditions, the octane and diethylzinc mixture boiled, filling the chamber with vapor. A condenser at the top of the chamber condensed the vapor and returned the condensate directly to the boiling solution in the bottom of the chamber, maintaining an effective concentration of diethylzinc vapor in the chamber.
The chamber was maintained at a temperature of 60° to 66° C and a pressure of 85 Torr for 1.5 hours, with a slow but steady reflux from the condenser during this time. The heat was then shut off and the chamber cooled, repressurized to atmospheric pressure and purged with slightly moist nitrogen for three hours to destroy any excess diethylzinc.
TABLE V______________________________________                         MIT FOLD                        Endurance        Alkalinity                Bright- 1/2 Kg load      pH  Meg/Kg    ness    MD*   CB**______________________________________JCP-A60 Offset paper,              1135±                                    420±control (untreated)        5.4   --        72.5  240   116JCP-A60 Offset paperdouble treated withDEZ          7.7   88        73.5  839±                                    364±                              224   139Newsprint, Control                 193±                                    31±(Untreated)  5.1   --        54.4  58    11Newsprint, double                  199±                                    59±treated with DEZ        7.7   88        52    27    25______________________________________ (±figures after MIT fold values are standard deviations) *Folds machine direction **Folds cross direction
TABLE VI______________________________________Dry Oven Aging at 100°  3 days      6 days     12 days    MD* MIT   Bright  MIT  Bright                                 MIT  Bright    Fold      ness    Fold ness  Fold ness______________________________________JCP-A60 Off-set paper, un-treated con-trol     354       69.3    203  69.6  33   68Double DEZTreatment    657       71.0    322  69.8  205  66Newsprint,Untreated     7        46      3    42.6  0.5  35controlDouble DEZTreatment     46       43      10   42.0  1.6  40Humid Oven Aging at 90° C & 50% R. H.  3 days      6 days     12 days    MD MIT    Bright  MIT  Bright                                 MIT  Bright    Fold      ness    Fold ness  Fold ness______________________________________JCP-A60 Off-set paper, un-treated con-trol     641       70.4    391  69.2  130  68Double DEZTreatment    701       70.0    652  66    337  64Newsprint,Untreated     54       46.1     8   44    0.9  38ControlDouble DEZTreatment     65       46.2     48  42    41   40______________________________________ *Folds machine direction
TABLE VII______________________________________Dry Oven       0       3       6     12    Fold,MDNewsprint   Days /  Days /  Days /                             Days /                                   36 Days Untreated control     193     7      3.3   1.6   0Newsprint Treated with DEZ&NH.sub.3        134     56     18    3.1   1.0JCP-A60 Untreatedcontrol     1135    354     203   38    1.5JCP-A60 Treatedw/ DEZ & NH.sub.3       1012    644     411   271   10.2Humid OvenNewsprint Untreated control     193     54     8.4   0.9   0Newsprint Treated with DEZ & NH.sub.3        134     81     94    51    18JCP-A60 Untreatedcontrol     1135    641     391   130   3.1JCP-A60 Treatedw/ DEZ & NH.sub.3       1012    475     479   303   59______________________________________
A packet of papers 81/2 × 11 inches in size consisting of 36 sheets of 50 lb. basis wt. offset paper with a total weight of 150 grams was placed in the treatment chamber and dried under vacuum at 65° C. After 5 hours the pressure had dropped to 0.1 Torr, indicating substantial dryness. Then 5 ml of trimethyl aluminum was injected into the chamber, taking care that none contacted the paper in the liquid state. Litle change in pressure or temperature was noted, but reflux from the condenser started immediately. Reflux was continued for two hours, after which the heat was shut off, the reactor cooled, and the pressure returned to atmospheric by back filling with nitrogen. The excess triethylaluminum was destroyed with a few ml of methanol, and the papers removed. A comparison of the papers before and after treatment is shown in Table VIII.
A packet of four different papers, a 70 lb. kraft paper, newsprint, rag handsheets, and 50 lb. offset paper, total weight 70.6 g, was placed in the chamber and evacuated at room temp (25° C) for six hours to a pressure of 0.1 Torr. At this time a stable pressure was established. Then 10 grams of diethylzinc was added, which raised the pressure to 15 mm. Slight reflux was obtained from the condenser on the chamber. The condenser was operated at 10° C while the chamber was maintained at 25° C and 15 Torr pressure. After 5 hours there was no further evidence of reflux or liquid in the chamber. The chamber was backfilled with nitrogen to atmospheric pressure and purged. There was no evidence of excess diethylzinc in the purge gas effluent. The chamber was then opened and the papers removed. The papers analyzed as shown in Table VIII.
"Writing Paper, suitable for Offset, G.P.O. No. 21056 and Property 6926, 4.4 lbs. per 500, 8 × 101/2 inch sheets were soaked for 10 minutes in a 15% solution of diethylzinc in heptane. The sheet was then drained under nitrogen and following this exposed to room conditions. There was a small temperature rise, approximately 1° C, as the diethylzinc hydrolyzed. The paper was air dried and stored for two weeks. Samples were then exposed for 12 days in the 100° C dry oven. This gives aging equivalent to 100 years under ambient conditions. Samples were also exposed for 12 days in the 90° C, 50% relative humidity oven to check the effect of moisture vapor which is, of course, present in normal aging.
TABLE IX______________________________________                           Folding Endur-         pH     Brightness ance (1/2 kg)______________________________________Control       6.8    70         345Control 12 days 100° C oven         5.0    60          12Control 12 days 90° C, 50%R.H.         4.6    61          14TABLE XAs treated    7.6    68         --As treated, 12 days100 ° C oven         6.9    62         120As treated, 12 dayshumid oven    7.1    56         200______________________________________
TABLE XI______________________________________                        Folding Endur-        pH   Brightness ance (1/2 kg)______________________________________As treated     7.8    71         --As treated, 12 days          7.1    64         104100° C ovenAs treated, 12 days          7.1    60         134humid oven______________________________________
TABLE XII______________________________________                        Folding Endur-        pH   Brightness ance (1/2 kg)______________________________________As treated     7.8    69         --As treated, 100° Coven           7.3    64          97As treated, 90° C,50% RH oven    7.2    60         159______________________________________
Even the lower amount of diethylzinc has satisfactorily deacidified and buffered the papers. The pH has again been held at neutrality during oven aging, in contrast to the control which went to the acid side. Brightness of the treated samples is quite satisfactory. Folding endurance is 8 times that of the conrol for the 100° C oven and 11 times that for the humid oven.
TABLE XIII______________________________________Newsprint                            Folding Endur-          pH     Brightness ance (1/2 kg)______________________________________Control        6.6    52         39Control, 100° oven          4.5    37         2Control, humid oven          4.2    35         1TABLE IVXNewsprintAs dipped      8.0    59         --As dipped, 100° C oven          7.3    43         3As dipped, humid oven          7.2    46         73______________________________________
Again, the lower concentration of diethylzinc has kept the samples neutral over the oven aging period. Brightness, in this experiment, is substantially improved over the control. Folding endurance has not been helped in the 100° C dry oven, but in the humid oven a remarkably good effect has been obtained, in which fold is actually almost twice as good as the unaged control.
TABLE XV______________________________________                        Folding Endur-        pH   Brightness ance (1/2 kg)______________________________________As treated     8.6    70         --As treated, 100° C oven          9.3    62         56As treated, 50% RH,          7.5    62         6090° C oven______________________________________
US05660286 1974-12-24 1976-02-23 Method of deacidifying paper Expired - Lifetime US4051276A (en)
US05536125 US3969549A (en) 1974-12-24 1974-12-24 Method of deacidifying paper
US05660286 US4051276A (en) 1974-12-24 1976-02-23 Method of deacidifying paper
US05536125 Division US3969549A (en) 1974-12-24 1974-12-24 Method of deacidifying paper
US4051276A true US4051276A (en) 1977-09-27
ID=27065041
US05660286 Expired - Lifetime US4051276A (en) 1974-12-24 1976-02-23 Method of deacidifying paper
US (1) US4051276A (en)
DE3913293A1 (en) * 1988-04-26 1989-11-09 Morris Jesse Warren A method for preserving printed cellulosic materials
DE3904111A1 (en) * 1989-02-11 1990-08-16 Battelle Institut E V Method and apparatus for environmentally friendly mass deacidification of books and other paper products
FR2666355A1 (en) * 1990-09-05 1992-03-06 Arnoult Alain Process for disinfecting graphic documents and device for its use
US5094888A (en) * 1990-02-20 1992-03-10 Fmc Corporation Strengthening cellulosic materials
US5104997A (en) * 1988-09-30 1992-04-14 Fmc Corporation Mass treatment of cellulosic materials
US5282320A (en) * 1991-08-23 1994-02-01 Fmc Corporation Book drying process
US5393562A (en) * 1993-03-02 1995-02-28 The United States Of America As Represented By The Librarian Of Congress Method of preserving and storing books and other papers
US5827578A (en) * 1994-10-13 1998-10-27 Bell; Oswald Process and device for deacidifying printed material and paper products of all kinds
EP1002899A1 (en) * 1998-11-11 2000-05-24 ZFB Zentrum für Bucherhaltung GmbH Super critical carbon dioxide for the antimicrobial treatment of contaminated paper
JP2014077197A (en) * 2012-10-09 2014-05-01 Samsung Corning Precision Materials Co Ltd Zinc oxide precursor and method of depositing zinc oxide-based thin film using the same
FR2631890A1 (en) * 1988-04-26 1989-12-01 Warren Morris Method and composition for preserving, for deacidification of cellulosic materials Printed
US5120581A (en) 1992-06-09 Method for reducing the combustibility of combustible materials
US4363699A (en) 1982-12-14 Process for stabilizing solutions of peroxidic compounds used for bleaching
US4796381A (en) 1989-01-10 Insecticidal compositions
US4522843A (en) 1985-06-11 Deacidification of library materials
US4291101A (en) 1981-09-22 Wood fibrous material and a method for improving the qualities thereof
US4335109A (en) 1982-06-15 Water repellent aqueous wood treating solutions