US3707437A - Pulping and bleaching of wood chips in a single stage with tertiary butyl hydroperoxide - Google Patents
Pulping and bleaching of wood chips in a single stage with tertiary butyl hydroperoxide Download PDFInfo
- Publication number
- US3707437A US3707437A US3707437DA US3707437A US 3707437 A US3707437 A US 3707437A US 3707437D A US3707437D A US 3707437DA US 3707437 A US3707437 A US 3707437A
- Authority
- US
- United States
- Prior art keywords
- pulp
- percent
- chips
- tertiary butyl
- butyl hydroperoxide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04D—ROOF COVERINGS; SKY-LIGHTS; GUTTERS; ROOF-WORKING TOOLS
- E04D5/00—Roof covering by making use of flexible material, e.g. supplied in roll form
- E04D5/02—Roof covering by making use of flexible material, e.g. supplied in roll form of materials impregnated with sealing substances, e.g. roofing felt
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C3/00—Pulping cellulose-containing materials
- D21C3/003—Pulping cellulose-containing materials with organic compounds
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
- D21C9/10—Bleaching ; Apparatus therefor
- D21C9/16—Bleaching ; Apparatus therefor with per compounds
- D21C9/163—Bleaching ; Apparatus therefor with per compounds with peroxides
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T156/00—Adhesive bonding and miscellaneous chemical manufacture
- Y10T156/10—Methods of surface bonding and/or assembly therefor
- Y10T156/1052—Methods of surface bonding and/or assembly therefor with cutting, punching, tearing or severing
- Y10T156/1084—Methods of surface bonding and/or assembly therefor with cutting, punching, tearing or severing of continuous or running length bonded web
- Y10T156/1085—One web only
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
- Y10T428/24355—Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
- Y10T428/24372—Particulate matter
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
- Y10T428/24355—Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
- Y10T428/24372—Particulate matter
- Y10T428/24413—Metal or metal compound
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
- Y10T428/24355—Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
- Y10T428/24372—Particulate matter
- Y10T428/24421—Silicon containing
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/249921—Web or sheet containing structurally defined element or component
- Y10T428/249924—Noninterengaged fiber-containing paper-free web or sheet which is not of specified porosity
- Y10T428/249933—Fiber embedded in or on the surface of a natural or synthetic rubber matrix
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T442/00—Fabric [woven, knitted, or nonwoven textile or cloth, etc.]
- Y10T442/50—FELT FABRIC
- Y10T442/59—At least three layers
Definitions
- This invention relates to a method for the single stage high-yield pulping and bleaching of wood chips using a combination of tertiary butyl hydroperoxide and an aqueous alkaline medium such as aqueous sodium hydroxide.
- Prior art Wood pulps can be classified into four groups.
- Mechanical pulp or groundwood pulp is produced by a mechanical disintegration of the wood in the presence of water, generally by pressing the debarked logs against a grinding wheel rotated at high speeds.
- the yield of pulp is quite high generally from 90 to 95 percent.
- Chemi-mechanical pulps are obtained by a very mild chemical treatment to soften the wood without significant delignification. This treatment is followed by disintegrating mechanically to give a yield of pulp in the range of 80 to 95 percent.
- Semi-chemical pulps are produced by somewhat stronger cooking conditions wherein partial delignification occurs and this is followed by defibering with a mechanical treatment. Pulp yields are in the range of from 55 to 80 percent.
- Chemical pulps are obtained by a vigorous chemical treatment which removes interfiber lignins so that the fibers can separate without mechanical treatment or with only a minimum amount of mechanical treatment.
- the pulp thus produced in yields of about 42 to 58 percent requires strong bleaching since the chemical treatment frequently results in the production of a pulp which is considerably darker than the color of the original chips.
- Chemical pulps also contain high molecular weight lignin fractions which are not easily removed.
- Chemical pulping can be further sub-divided into alkaline pulping (the kraft process involving sodium hydroxide and sodium sulfide) and the acid pulping process.
- the chemical pulping methods produce high strength papers at a considerable sacrifice in pulp yield and in addition require extensive bleaching.
- In order to accomplish the bleaching at least four separate stages are usually required. In the first stage chlorine is employed and thereafter the pulp is extracted with an alkaline solution. The next stage involves the use of hypochlorite and the final bleach is usually accomplished with chlorine dioxide. In certain instances one or more of these steps may
- lignin sulfonic acids In the sulfite processes (chemi-mechanical and semichemical methods) lignin sulfonic acids, sulfite and sulfur dioxide are the pollutants.
- the lignin sulfonic acids which pollute streams from these pulping plants are bio-hard i.e., they are not susceptible to bacterial degradation and the effects of sulfur dioxide in the atmosphere cannot be minimized.
- a high-yield pulp is obtained, the yield being comparable to that obtained by the semi-chemical pulping.
- the yield is considerably superior to the yield obtained in the kraft process.
- the present method does not degrade the color during the pulping operation with the result the pulp obtained is not darker than the original wood chip and thus the extensive bleach which characterizes other prior art process and in particular the kraft process is avoided.
- Considerable delignification is obtained by the alkaline tertiary butyl hydroperoxide process of this invention while the cellulose is protected and color formation is avoided.
- the paper obtained from the pulp therefore, is superior in strength to that obtained from groundwood or semi-chemical methods and is only slightly inferior to the strength of the paper obta ned from the kraft process.
- the process of this invention has an even greater important advantage, namely it obviates completely the pollution problems associated with the prior art chemical processes which have been discussed and in addition does not present new or dangerous pollution problems.
- the tertiary butyl hydroperoxide is converted to tertiary butyl alcohol which when burned With the lignin is converted to water and carbon dioxide. It is so highly combustible that its combustion is complete and therefore does not product even small amounts of carbon monoxide.
- the tertiary butyl alcohol can be recovered as a valutable chemical compound.
- the process of the instant invention also provides substantial amounts of bleaching with the result that the use of pollution type bleaches can be substantially eliminated.
- the sodium hydroxide employed in the process is recovered in the same manner as in the kraft process, i.e. during the burning of the lignin it is converted to sodium carbonate Which in turn is reacted with unslaked lime thereby regenerating the sodium hydroxide and producing the insoluble calcium carbonate a non-polluting chemical compound.
- the advantages of the instant method of pulping over prior art methods are the production of a high yield, semi-chemical pulp, by an alkaline pulping method, requiring little if any further bleaching.
- the yields are comparable to those of the groundwood and semi-chemical methods and superior to the kraft process.
- the process does not degrade the color of the pulp and the paper obtained from the pulp is superior in strength to the paper from groundwood or semi-chemical pulps while being only slightly inferior to kraft paper and finally, it is the only method known which can substantially completely eliminate environmental pollution.
- wood chips are digested with an aqueous solution of tertiary butyl hydroperoxide and sodium hydroxide.
- the hydroperoxide perferably ranges in an amount from 2 percent to 40 percent by weight based on the weight of the dry chips and the sodium hydroxide is in an amount such that the weight ratio of tertiary butyl hydroperoxide to sodium hydroxide ranges from 4:1 to 1:3 with from 2:1 to 1:2 being preferred.
- the digestion can be carried out at a temperature in the range of from about C. to 150 C. and preferably in the range of from about 60 C. to 130 C., a particularly preferred range is from 80 C. to 110 C. At these temperatures digestion times of from 15 minutes for the higher temperatures to 120 minutes for the lower temperatures can be used. The digestion, however, can be carried out at ambient temperatures with greater efliciency with respect to chemical utilization although longer times are required. Thus reaction is time-temperature dependent i.e., with higher temperatures shorter reaction times can be used whereas with the lower temperatures longer reaction times are required. Satisfactory results are obtained with a ratio of total liquor to wood being in the range of from 1:1 to 3:1.
- the process of the instance invention is useful with both the wood chips derived from softwoods (those from some gymnosperms) and hardwoods (those from some angiosperms). From the softwoods the coniferous species such as cedar, fir, hemlock, pine and spruce are suitable. From the hardwoods the instant process is useful for pulping and bleaching such woods as alder, aspen, beech, birch, gum, oak and the like.
- the instant process can be carried out either by batch procedures or continuously in accordance with well known paper mil engineering procedures.
- the liquor resulting from the treating step contains some unreacted tertiary butyl hydroperoxide together with tertiary butyl alcohol and the water soluble lignin derivatives.
- the tertiary butyl hydroperoxide and tertiary butyl alcohol can be recovered by distillation and the tertiary butyl hydroperoxide recycled to the process.
- Tertiary butyl alcohol can be sold as a chemical and the water solution of the lignin derivatives can be treated in accordance with well known methods to recover a large number of valuable compounds.
- the instant process is superior to the kraft process since in the latter process the lignin is in the form of sulfur derivatives and generally polymerization has occured so that it is almost impossible to recover byproducts and instead the lignin derivatives are simply burned. This, of course, leads to atmospheric pollution.
- tertiary butyl hydroperoxide has become available in large commercial quantities, the most important method of production being by the oxidation of isobutane.
- This process produces an oxidate from which the tertiary butyl hydroperoxide can be obtained in pure form or the oxidate itself can be employed since it consists of a mixture of the hydroperoxide and tertiary butyl alcohol.
- the tertiary butyl hydroperoxide also has the advantage over organic peroxide compounds such as peracetic acid and the like in that it is stable and can be handled and shipped readily using normal precautions. Other organic peroxide compounds, on the other hand, are highly unstable and dangerous to ship since they are exceedingly unstable and explosive.
- the sodium hydroxide utilized in the process can be ordinary commercial caustic and the process is carried out utilizing an aqueous solution of the tertiary butyl hydroperoxide and the caustic so that no difiicult handling problems are encountered and no special auxiliary solvents or specialized equipment need be employed.
- the digestions of the wood chips in the aqueous solution of tertiary butyl hydroperoxide and sodium hydroxide can be carried out at temperatures in the rang of from about 0 C. to 150 C. A more preferable range is from about 60 C. to about 130 C., and in particular a range of from C. to C. is preferred. If it is desired to obtain the greatest possible efiiciency in chemical utilization, the digestion can be carried out at ambient temperatures. At this temperature, however, digestion times of several hours or days may be required, whereas at higher temperatures times of from about 15 minutes for the temperatures in the upper end of the range, to 2 hours or longer for temperatures in the lower end of the range can be used.
- the digestion is a time-temperature depending reaction. Atmospheric to reaction autogenous pressure can be used.
- the concentration of the hydroperoxide can range from 2 percent to 40 percent by weight based on the weight of dry chips, although higher concentrations can be utilized. A range of from 10 to 35 weight percent based on the weight of the dry chips has been found to be completely satisfactory for most woods.
- the amount of sodium hydroxide employed is related to the amount of hydroperoxide used so that the weight ratio of tertiary butyl hydroperoxide to sodium hydroxide ranges from about 4:1 to, 1:3 with. a range of from about 2:1 to 1:2, being preferred.
- the weight ratio of total liquor to dry wood preferably ranges from about 1:1 to 3:1, although higher or lower ratios may be employed with particular types of wood and digestion conditions.
- the most important process is the kraft process since two-thirds of all wood pulp is manufacture by this process. Most of the ligning and hemi-celluloses are converted to the water soluble form by the digestion step, wherein an aqueous sodium hydroxide-sodium sulfide solution is used to cook the wood chips for several hours at 100 to 200 C. There is left the cellulose fraction (45-55 percent of the original wood) in the form of a highly colored pulp.
- the principal advantage of the kraft process is the production of a very strong pulp while the lignin fraction is burned to supply power for the process.
- the disadvantages of the kraft process are the pollution problems from the digestion, burning and bleaching steps as has been described. Processes developed to avoid the disadvantages of the kraft process are those employing oxidants such as chlorite, hydrogen peroxide and peracetic acid. The advantage of these processes is higher pulp yields with less pollution, but these have not produced paper of sufiiciently high quality at an economic price. Accordingly, in
- the chips were transferred to vessels of about 400 ml. capacity and because of the relatively low liquor to wood ratios there was usually no free liquor.
- the vessels were capped and kept in a controlled-temperature oil bath which had been preheated sufficiently above the selected temperature so that the heat flow to the vessels caused the temperature to fall to that for the reaction, which required about 3 minutes.
- the vessels were withdrawn and quenched in cold water. Known amounts of water were added to facilitate removal of the product from the vessels.
- the chips and diluted spent liquor were left over night to equilibrate at ambient temperature and at about 12 percent consistency before withdrawing the liquor for pH determination. For yield and lignin determinations the cooked chips were collected and washed with several 12 hr. soakings in warm distilled water until the filtrate had a pH of 7-7.5 and was clear.
- the raw material for the examples which follow was prepared from the two peeled quaking aspen bolts which were chipped into about Ag in. chips in a 4-knife, 38-in. Carthage chipper. The chips were screened on a Sweco screen and the large knots and slivers were removed from the on-2-mesh fraction, the accepted chips were broken down further in a l2-in. Sprout-Waldron refiner fitted with B2975A spiked plates set at a near-zero gap. The chips, after this reduction, were put through a Sweco screen and the through-4on-10-mesh fraction were used in the pulping runs. These chips were about to in. cross section and approximately in. in length.
- Solutions for treating the chips were prepared by mixing the required weights of aqueous solutions containing 10 wt. percent tertiary butyl hydroperoxide and 20 wt. percent sodium hydroxide, then, further diluting with water to the specified liquor to wood ratio.
- the chips to be cooked were placed on a polyethylene sheet and turned over while being sprayed with a calculated amount of the appropriate solutions to achieve the diiferent liquor compositions used. After they had In order to understand the relationship between pulp yield and weight percent Klason lignin on dry pulp basis and the weight percent Klason lignin removed an explanation of these determinations is necessary. Thus, in run 4, for example, for each g. of chips, since the pulp yield was 76 percent, there would be 76 g. of pulp and 24 g. of the chips removed as solids in the liquor. Since the lignin content of the pulp was 14 percent, there would be 10.7 g. of lignin in the pulp and 10.4 g. of lignin in the solids of the liquor.
- Pulp S was prepared with an alkaline liquor only, and pulp HP had machine. Each pulp was dewatered, and washed in a centrifuge.
- Sheet density, breaking length, burst factor, and Elmendorf tear factor were determined according to TA-PPI Standard Method T 220 m-60.
- the breaking length for pulp HP was found to be TABLE V very good and covering a much wider range than pulp HYSC and also a wider range than pulp S.
- the breaking length range of 4000-9000 In. for an 81 percent yield aspen pulp (pulp HP) is the same as that obtained with an 82 percent yield spruce pulp, described by Rydholm, Pulping Processes, p. 284, New York, Interscience 1965.
- EXAMPLE V Two runs were carried out to compare cooking with tertiary butyl hydroperoxide and with peractic acid. As described in the prior art section herein, peracetic acid and alkali have been proposed for the pulping of hardwoods, including poplar, in 2-stages. To determine whether peractic acid and tertiary butyl hydroperoxide are interchangeable in such processing, runs were carried out modeled on the 2-stage process as set forth in Table V.
- Reagent Bath temperature C 95 Amount of oxidant, wt. percent O.D. wood 8.8 8. 8 Liquorzwood 2. 2:1 2. 2: 1
- Kappa number 92 Approx. Klason lignin, wt. percent O.D. pulp 21 14 GE bri htness 32 30 Sheet density, g./ec 0. 54 0. 50 Breaking length, m 4, 700 6, 3000 t-Butyl hydroperoxide.
- EXAMPLE VI Fifty grams of poplar chips, (nominal /3 inch) equal to 40.0 grams if oven dried, together with 20.0 g. t-butyl hydroperoxide, 8.0 g. sodium hydroxide and 224 g. of Water were slowly stirred in a round-bottomed flask for 3.5 hrs. at 85 C. The cooking solution and the chips were a light yellow color, the chips were soft and easily subdivided. After 20 seconds in a Waring Blendor with 300 ml. of water and pH adjustment to 6.4 by adding 8.0 ml. 10 percent sodium bisulfite, the pulp was filtered, water washed several times and oven-dried. The handsheet weighed 25.6 g. equal to 64 percent of the original chips. A Photovolt brightness on the dried handsheet was 86, for comparison a CEH kraft read 79 and a CEHD kraft read 91.
- the product Based on the lignin removal, the appearance of the handsheet and microscopic examination, the product is classified as a bright semi-chemical pulp.
- EXAMPLE VII Similar results were obtained with wood chips of other species including: loblolly pine, white spruce, tan oak,
- EXAMPLE IX In order to show that ambient temperature treatments are effective, aspen chips g.) were allowed to stand at room temperature for one week with an aqueous solution containing 10 wt. percent tertiary butyl hydroperoxide, 4 wt. percent sodium hydroxide (50 g. solution per 10 g. oven dried chips).
- the chips were separated, water washed and sodium bisulfite added to pH 6.5. After 1 hour in a Hobert mixer, the pulp was converted to a handsheet weighing 7.2 g. oven dried and having a Photovolt brightness of 76. For comparison, a CEH kraft read 79.
- the present pulping and bleaching process completely eliminates the pollution problems of sulfur pulping (the wraft or sulfite processes) as well as their chlorine bleaching pollution problems.
- a method for the pulping and bleaching of wood chips in a single stage which comprises treating said chips with a mixture consisting of tertiary butyl hydroperoxide and sodium hydroxide in an aqueous solution at a temperature in the range of from 0 C. to 150 C., at pressures ranging from atmospheric to the autogeneous pressure of the reaction at the temperature employed, the concentration of said hydroperoxide ranging from 2 to 40 weight percent based on the weight of the dry chips, the ratio of said hydroperoxide to sodium hydroxide ranging from about 4:1 to 1:3 and the weight ratio of total liquor to dry wood ranging from about 1:1 to 3:1.
- hydroperoxide concentration is in the range of from 10 to 35 weight percent.
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- Engineering & Computer Science (AREA)
- Architecture (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Wood Science & Technology (AREA)
- Roof Covering Using Slabs Or Stiff Sheets (AREA)
- Paper (AREA)
- Synthetic Leather, Interior Materials Or Flexible Sheet Materials (AREA)
Abstract
Description
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US5819870A | 1970-07-24 | 1970-07-24 | |
US5879870A | 1970-07-24 | 1970-07-24 | |
US14130971A | 1971-05-07 | 1971-05-07 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3707437A true US3707437A (en) | 1972-12-26 |
Family
ID=27369412
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US3707437D Expired - Lifetime US3707437A (en) | 1970-07-24 | 1970-07-24 | Pulping and bleaching of wood chips in a single stage with tertiary butyl hydroperoxide |
US3707432D Expired - Lifetime US3707432A (en) | 1970-07-24 | 1971-05-07 | Reinforced fibrous felts for roofing shingle manufacture |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US3707432D Expired - Lifetime US3707432A (en) | 1970-07-24 | 1971-05-07 | Reinforced fibrous felts for roofing shingle manufacture |
Country Status (7)
Country | Link |
---|---|
US (2) | US3707437A (en) |
BE (1) | BE769478A (en) |
CA (2) | CA949263A (en) |
DE (2) | DE2128723A1 (en) |
FR (2) | FR2100243A5 (en) |
GB (1) | GB1305496A (en) |
NL (1) | NL7109280A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5274139A (en) * | 1993-02-26 | 1993-12-28 | University Of Florida | Method for effective reaction between oxygen and organic substance utilizing regenerable hydroperioxide oxidant |
Families Citing this family (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
BE789730A (en) * | 1971-10-07 | 1973-04-05 | Bitumarin Nv | PROCESS FOR MANUFACTURING LARGE SHEETS OF COATED MATERIAL AND THEIR APPLICATION TO HYDRAULIC ENGINEERING |
US4032491A (en) * | 1973-10-19 | 1977-06-28 | Butler-Schoenke Roofing Specialties, Inc. | Roofing composition and resulting product |
US4250221A (en) * | 1976-04-29 | 1981-02-10 | Consolidated Fiberglass Products Co. | Fiberglass mat |
GB1577561A (en) * | 1976-04-29 | 1980-10-29 | Cons Fiberglass Prod | Fibreglass mat |
US4559103A (en) * | 1982-08-05 | 1985-12-17 | Honshu Seishi Kabushiki Kaisha | Packaging paper and packaging material for packaging metallic material and method of producing the same |
FR2640288B1 (en) * | 1988-12-13 | 1993-06-18 | Rhone Poulenc Fibres | NON-WOVEN TABLECLOTH SUPPORT IN CHEMICAL TEXTILE AND METHOD OF MANUFACTURING THE SAME |
US10315385B2 (en) | 2011-08-05 | 2019-06-11 | Certainteed Corporation | System, method and apparatus for increasing surface solar reflectance of roofing |
US9631367B2 (en) | 2011-08-05 | 2017-04-25 | Certainteed Corporation | System, method and apparatus for increasing surface solar reflectance of roofing |
USD855220S1 (en) * | 2016-04-01 | 2019-07-30 | Certainteed Corporation | Shingle |
US10858833B2 (en) | 2016-04-01 | 2020-12-08 | Certainteed Corporation | Roofing shingle |
-
1970
- 1970-07-24 US US3707437D patent/US3707437A/en not_active Expired - Lifetime
-
1971
- 1971-05-07 US US3707432D patent/US3707432A/en not_active Expired - Lifetime
- 1971-05-26 CA CA113,960A patent/CA949263A/en not_active Expired
- 1971-05-27 GB GB1767871A patent/GB1305496A/en not_active Expired
- 1971-06-09 DE DE19712128723 patent/DE2128723A1/en active Pending
- 1971-07-02 BE BE769478A patent/BE769478A/en unknown
- 1971-07-05 NL NL7109280A patent/NL7109280A/xx unknown
- 1971-07-05 FR FR7124476A patent/FR2100243A5/fr not_active Expired
-
1972
- 1972-05-05 FR FR7216161A patent/FR2139310A5/fr not_active Expired
- 1972-05-05 DE DE2222915A patent/DE2222915C3/en not_active Expired
- 1972-05-05 CA CA141,414A patent/CA977520A/en not_active Expired
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5274139A (en) * | 1993-02-26 | 1993-12-28 | University Of Florida | Method for effective reaction between oxygen and organic substance utilizing regenerable hydroperioxide oxidant |
Also Published As
Publication number | Publication date |
---|---|
NL7109280A (en) | 1972-01-26 |
DE2222915C3 (en) | 1975-05-07 |
BE769478A (en) | 1972-01-03 |
FR2100243A5 (en) | 1972-03-17 |
CA977520A (en) | 1975-11-11 |
DE2222915A1 (en) | 1973-05-24 |
FR2139310A5 (en) | 1973-01-05 |
GB1305496A (en) | 1973-01-31 |
CA949263A (en) | 1974-06-18 |
US3707432A (en) | 1972-12-26 |
DE2222915B2 (en) | 1974-09-19 |
DE2128723A1 (en) | 1972-01-27 |
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