CA2076308C - Deinking composition for flotation and deinking method - Google Patents
Deinking composition for flotation and deinking methodInfo
- Publication number
- CA2076308C CA2076308C CA 2076308 CA2076308A CA2076308C CA 2076308 C CA2076308 C CA 2076308C CA 2076308 CA2076308 CA 2076308 CA 2076308 A CA2076308 A CA 2076308A CA 2076308 C CA2076308 C CA 2076308C
- Authority
- CA
- Canada
- Prior art keywords
- deinking
- propylene oxide
- ethylene oxide
- flotation
- added
- 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
- 239000002761 deinking Substances 0.000 title claims abstract description 117
- 239000000203 mixture Substances 0.000 title claims abstract description 98
- 238000000034 method Methods 0.000 title claims abstract description 86
- 238000005188 flotation Methods 0.000 title claims abstract description 62
- GOOHAUXETOMSMM-UHFFFAOYSA-N Propylene oxide Chemical group CC1CO1 GOOHAUXETOMSMM-UHFFFAOYSA-N 0.000 claims abstract description 69
- IAYPIBMASNFSPL-UHFFFAOYSA-N Ethylene oxide Chemical compound C1CO1 IAYPIBMASNFSPL-UHFFFAOYSA-N 0.000 claims abstract description 67
- 150000001875 compounds Chemical class 0.000 claims abstract description 30
- 239000010893 paper waste Substances 0.000 claims abstract description 20
- 229920001577 copolymer Polymers 0.000 claims abstract description 11
- 229920001451 polypropylene glycol Polymers 0.000 claims abstract description 9
- 150000001346 alkyl aryl ethers Chemical class 0.000 claims abstract description 6
- 229920003171 Poly (ethylene oxide) Polymers 0.000 claims abstract description 5
- 238000002156 mixing Methods 0.000 claims abstract description 5
- 230000008929 regeneration Effects 0.000 claims abstract description 5
- 238000011069 regeneration method Methods 0.000 claims abstract description 5
- 239000002245 particle Substances 0.000 claims description 24
- 239000013055 pulp slurry Substances 0.000 claims description 17
- 125000000217 alkyl group Chemical group 0.000 claims description 15
- 125000004432 carbon atom Chemical group C* 0.000 claims description 11
- 229920000233 poly(alkylene oxides) Polymers 0.000 claims description 5
- 239000000976 ink Substances 0.000 description 57
- 238000005406 washing Methods 0.000 description 25
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 24
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 23
- 230000032683 aging Effects 0.000 description 21
- 238000005187 foaming Methods 0.000 description 21
- GLDOVTGHNKAZLK-UHFFFAOYSA-N octadecan-1-ol Chemical compound CCCCCCCCCCCCCCCCCCO GLDOVTGHNKAZLK-UHFFFAOYSA-N 0.000 description 18
- 150000001298 alcohols Chemical class 0.000 description 16
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 16
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 15
- 239000003054 catalyst Substances 0.000 description 15
- 125000002947 alkylene group Chemical group 0.000 description 14
- 239000006260 foam Substances 0.000 description 14
- 230000008569 process Effects 0.000 description 14
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 12
- 238000002360 preparation method Methods 0.000 description 12
- 239000006227 byproduct Substances 0.000 description 11
- GOQYKNQRPGWPLP-UHFFFAOYSA-N heptadecan-1-ol Chemical compound CCCCCCCCCCCCCCCCCO GOQYKNQRPGWPLP-UHFFFAOYSA-N 0.000 description 11
- 239000012467 final product Substances 0.000 description 10
- 230000000694 effects Effects 0.000 description 9
- 229940012831 stearyl alcohol Drugs 0.000 description 9
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 8
- 229910001873 dinitrogen Inorganic materials 0.000 description 8
- 239000002002 slurry Substances 0.000 description 8
- 238000012360 testing method Methods 0.000 description 7
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 6
- 229920001515 polyalkylene glycol Polymers 0.000 description 6
- 150000002170 ethers Chemical class 0.000 description 5
- 239000007858 starting material Substances 0.000 description 5
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 4
- 239000005977 Ethylene Substances 0.000 description 4
- 239000002202 Polyethylene glycol Substances 0.000 description 4
- 239000004115 Sodium Silicate Substances 0.000 description 4
- 229910052799 carbon Inorganic materials 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 235000014113 dietary fatty acids Nutrition 0.000 description 4
- 239000004744 fabric Substances 0.000 description 4
- 239000000194 fatty acid Substances 0.000 description 4
- 229930195729 fatty acid Natural products 0.000 description 4
- 150000004665 fatty acids Chemical class 0.000 description 4
- 239000000835 fiber Substances 0.000 description 4
- 229920001223 polyethylene glycol Polymers 0.000 description 4
- 238000000926 separation method Methods 0.000 description 4
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 4
- 229910052911 sodium silicate Inorganic materials 0.000 description 4
- 230000003679 aging effect Effects 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- -1 ether compound Chemical class 0.000 description 3
- 230000007246 mechanism Effects 0.000 description 3
- 229920000642 polymer Polymers 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- 101100425600 Caenorhabditis elegans samp-1 gene Proteins 0.000 description 2
- 125000003158 alcohol group Chemical group 0.000 description 2
- 239000003513 alkali Substances 0.000 description 2
- 230000003466 anti-cipated effect Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 230000001419 dependent effect Effects 0.000 description 2
- NOPFSRXAKWQILS-UHFFFAOYSA-N docosan-1-ol Chemical compound CCCCCCCCCCCCCCCCCCCCCCO NOPFSRXAKWQILS-UHFFFAOYSA-N 0.000 description 2
- BXWNKGSJHAJOGX-UHFFFAOYSA-N hexadecan-1-ol Chemical compound CCCCCCCCCCCCCCCCO BXWNKGSJHAJOGX-UHFFFAOYSA-N 0.000 description 2
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 2
- 239000013067 intermediate product Substances 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 238000003672 processing method Methods 0.000 description 2
- 239000011541 reaction mixture Substances 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- CDBYLPFSWZWCQE-UHFFFAOYSA-L sodium carbonate Substances [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- TYWMIZZBOVGFOV-UHFFFAOYSA-N tetracosan-1-ol Chemical compound CCCCCCCCCCCCCCCCCCCCCCCCO TYWMIZZBOVGFOV-UHFFFAOYSA-N 0.000 description 2
- HLZKNKRTKFSKGZ-UHFFFAOYSA-N tetradecan-1-ol Chemical compound CCCCCCCCCCCCCCO HLZKNKRTKFSKGZ-UHFFFAOYSA-N 0.000 description 2
- 238000011282 treatment Methods 0.000 description 2
- FPLNRAYTBIFSFW-UHFFFAOYSA-N tricosan-1-ol Chemical compound CCCCCCCCCCCCCCCCCCCCCCCO FPLNRAYTBIFSFW-UHFFFAOYSA-N 0.000 description 2
- 238000004383 yellowing Methods 0.000 description 2
- ALSTYHKOOCGGFT-KTKRTIGZSA-N (9Z)-octadecen-1-ol Chemical compound CCCCCCCC\C=C/CCCCCCCCO ALSTYHKOOCGGFT-KTKRTIGZSA-N 0.000 description 1
- RSWGJHLUYNHPMX-UHFFFAOYSA-N Abietic-Saeure Natural products C12CCC(C(C)C)=CC2=CCC2C1(C)CCCC2(C)C(O)=O RSWGJHLUYNHPMX-UHFFFAOYSA-N 0.000 description 1
- 241001465754 Metazoa Species 0.000 description 1
- KHPCPRHQVVSZAH-HUOMCSJISA-N Rosin Natural products O(C/C=C/c1ccccc1)[C@H]1[C@H](O)[C@@H](O)[C@@H](O)[C@@H](CO)O1 KHPCPRHQVVSZAH-HUOMCSJISA-N 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- GSWGDDYIUCWADU-UHFFFAOYSA-N aluminum magnesium oxygen(2-) Chemical compound [O--].[Mg++].[Al+3] GSWGDDYIUCWADU-UHFFFAOYSA-N 0.000 description 1
- 239000010775 animal oil Substances 0.000 description 1
- 239000007844 bleaching agent Substances 0.000 description 1
- 229960000541 cetyl alcohol Drugs 0.000 description 1
- 238000001311 chemical methods and process Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000001112 coagulating effect Effects 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- MHDVGSVTJDSBDK-UHFFFAOYSA-N dibenzyl ether Chemical compound C=1C=CC=CC=1COCC1=CC=CC=C1 MHDVGSVTJDSBDK-UHFFFAOYSA-N 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 229960000735 docosanol Drugs 0.000 description 1
- LQZZUXJYWNFBMV-UHFFFAOYSA-N dodecan-1-ol Chemical compound CCCCCCCCCCCCO LQZZUXJYWNFBMV-UHFFFAOYSA-N 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- RTZKZFJDLAIYFH-UHFFFAOYSA-N ether Substances CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 235000021323 fish oil Nutrition 0.000 description 1
- 125000001165 hydrophobic group Chemical group 0.000 description 1
- BTFJIXJJCSYFAL-UHFFFAOYSA-N icosan-1-ol Chemical compound CCCCCCCCCCCCCCCCCCCCO BTFJIXJJCSYFAL-UHFFFAOYSA-N 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 229940043348 myristyl alcohol Drugs 0.000 description 1
- XGFDHKJUZCCPKQ-UHFFFAOYSA-N n-nonadecyl alcohol Natural products CCCCCCCCCCCCCCCCCCCO XGFDHKJUZCCPKQ-UHFFFAOYSA-N 0.000 description 1
- 229940055577 oleyl alcohol Drugs 0.000 description 1
- XMLQWXUVTXCDDL-UHFFFAOYSA-N oleyl alcohol Natural products CCCCCCC=CCCCCCCCCCCO XMLQWXUVTXCDDL-UHFFFAOYSA-N 0.000 description 1
- 125000004430 oxygen atom Chemical group O* 0.000 description 1
- 239000010773 plant oil Substances 0.000 description 1
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 1
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 1
- 238000004537 pulping Methods 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 102220038387 rs587780404 Human genes 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000012216 screening Methods 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 0.000 description 1
- 239000007790 solid phase Substances 0.000 description 1
- 230000009469 supplementation Effects 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
- 239000003760 tallow Substances 0.000 description 1
- KHPCPRHQVVSZAH-UHFFFAOYSA-N trans-cinnamyl beta-D-glucopyranoside Natural products OC1C(O)C(O)C(CO)OC1OCC=CC1=CC=CC=C1 KHPCPRHQVVSZAH-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- 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
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/64—Paper recycling
Landscapes
- Paper (AREA)
Abstract
A deinking composition for regeneration of waste paper by flotation comprises 99.7 to 97% by weight of a mixture which comprises monoalkyl ethers of ethylene oxide/propylene oxide copolymers represented by the following general formulas (A) and (B) and the mixing ratio of the compound (A) to the compound (B) ranges from 10:
90 to 90:10 (weight ratio); and about 0.3 to about 3.0% by weight of a polyoxyalkylene oxide selected from the group consisting of polyethylene oxides, polypropylene oxide and ethylene oxide/propylene oxide copolymers:
R1 O - (PO)n 1 - ~(EO)m ~ (PO) n2~ - H ~ (A) R2 O - (EO) m 1 - ~ (EO) m 2 ~ (PO) n ~ - H . . . . .. (g) wherein m/(n1 + n2) ranges .from 0.5 to 1.5; (m1 + m2)/n ranges from 1.1 to 2.0; EO and PO represent ethylene oxide and propylene oxide units respectively; and the EO and PO in the brackets may be in either a random or block configuration. The deinking composition exhibits excellent deinking properties. Therefore, the use of the deinking composition in the flotation method makes it possible to prepare high quality regenerated pulp, for paper-making, having a high brightness and a low content of remaining ink.
90 to 90:10 (weight ratio); and about 0.3 to about 3.0% by weight of a polyoxyalkylene oxide selected from the group consisting of polyethylene oxides, polypropylene oxide and ethylene oxide/propylene oxide copolymers:
R1 O - (PO)n 1 - ~(EO)m ~ (PO) n2~ - H ~ (A) R2 O - (EO) m 1 - ~ (EO) m 2 ~ (PO) n ~ - H . . . . .. (g) wherein m/(n1 + n2) ranges .from 0.5 to 1.5; (m1 + m2)/n ranges from 1.1 to 2.0; EO and PO represent ethylene oxide and propylene oxide units respectively; and the EO and PO in the brackets may be in either a random or block configuration. The deinking composition exhibits excellent deinking properties. Therefore, the use of the deinking composition in the flotation method makes it possible to prepare high quality regenerated pulp, for paper-making, having a high brightness and a low content of remaining ink.
Description
SPECIFICATION
TITLE OF THE INVENTION
Deinking Composition for Flotation and Deinking Method BACKGROUND OF THE INVENTION
The present invention relates to a deinking composition for reclaiming waste paper, which is used in the preparation of regenerated pulp from printed waste paper such as newspaper, magaaines, journals, wood-free paper, copying paper and computer printout paper and a method for using the deinking composition.
More specifically, the present invention relates to a deinking composition and a method of using the same, which are suitable for deinking printed waste paper through flotation, can provide high quality regenerated pulp having a high brightness and a low content of residual ink and can ensure a stable deinking operation.
There has long been known methods for reclaiming printed waste paper to give starting materials for paper-making. In particular, the reclaiming of printed waste paper has increasingly become important from the viewpoint of saving energy and natural resources as well as protection of environment and correspondingly there have been required for the development of techniques capable of providing high quality regenerated pulp having excellent properties such as a high brightness and a low content of residual ink.
In general, methods for deinking printed waste paper can roughly be divided into two groups, one of which is a washing method and the 20'6308 other of which is a flotation method. There have been known a variety of literatures and knowledges relating to these processing methods) deinking mechanisms and difference in quality between deinking compositions used in these processing methods. See, for instance, .5 Pulp & Paper, 1986, Nov. , p. 59; Pulp & Paper, 1989, Mar. , p. 60;
Pulp & Paper, I990) Mar. ) p. 76; Pulp & Paper, 1989, Mar. , p. 97;
Japanese Journal of Paper Technology. 1980, Aug., p. 37; 1989 TAPPI
Pulping Conference) p. 343; Japan TAPPI Journal, Vol. 36, p. 1029;
Japan TAPPI Journal) Vol. 39, p. 747; and U. S. Patent Nos. 4. 483) 74l and 4, 518) 459.
When summarizing literatures and, knowledges and experieneces which have been obtained through practical operations, the washing method in general comprises the step of repeatedly diluting and dehydrating a pulp slurry) or removing separated and dispersed ink particles from the pulp slurry through a screen or with a washing equipment such as a centrifugal cleaner. In this method) the separation of ink is greatly dependent upon, principally) mechanical conditions for due to washing equipments such as a press, a screen and a cleaner. Moreover, the washing method suffers from various problems concerning consumption of natural resources and energy since the use of a large amount of water is required. In addition, the washing method is greatly dependent upon mechanical factors and, therefore, workability of each step is regarded as important. In particular, when a composition having an intensive foaming ability, in particular, a deinking composition is employed) troubles due to foams arise in each equipment or process and this leads to reduction of workability and a marked increase in consumption of electric power. Thus, a composition having a low foaming ability or foaming-inhibitory properties must be used in the washing mehods. Further the separated ink particles must be fine and well dispersed in a pulp slurry in order to improve the efficiency of removing the separated ink.
On the other hand, the flotation method mainly comprises removing separated ink particles from a pulp slurry by adhering the ink particles to foams generated in a flotator. Thus) the mechanism of the removal of ink for the flotation method is completely different from that for the washing method and in other words, inks are principally removed through chemical processes unlike the washing method. The deinking method in which the flotation process is adopted sometimes comprises a so-called washing or dewatering step, but the separated ink particles are mainly removed in the flotation process.
The flotation method is advantageous in saving natural resources since the amount of water used in this method is smaller than that required for the washing method. To improve the effect of removing inks in the flotation method, the separated ink particles must be coagulated to form aggregates having a relatively large particle size.
Moreover, an appropriate foaming ability is required for the flotation process since the separated ink particles must be removed through the adhesion thereof to foams in the flotation method. This foaming ability required for the flotation method is higher than that required for the washing method. On the other hand. if the foaming ability of a composition, in particular, that of a deinking composition is too high, various problems arise. For instance, it is 20'6308 difficult to scrape out foams during the flotation process and various troubles due to foaming arise in each step. This leads to the interruption of the operation and the yield of pulp is reduced.
Accordingly, the deinking process cannot be carried out stably and it is sometimes difficult to obtain high quality regenerated pulp having a high brightness.
As has been discussed above in detail, the deinking mechanism for washing method is quite different from that for the flotation method and, therefore, they require the use of deinking compositions having different properties.
The flotation method has been adopted mainly in Japan and Europe because it can provide regenerated pulp having a brightness higher than that accomplished by the washing method and is excellent in saving in natural resources and energy as compared with the washing method. Moreover, the deinking method has recently been switched from the washing method to the flotation method likewise in the United States.
Until now, there have been filed a variety of patents relating to deinking compositions and methods for using the same. For instance, U. S. Patent No. 4, 518, 459 discloses a deinking method using a deinking composition obtained by adding a predetermined amount of propylene oxide to the terminal hydroxyl groups of alcohols or ethylene oxide adducts of alkylphenols, or by modifying, with benzyl ether, the terminal hydroxyl groups of alcohols or ethylene oxide- or ethylene oxide/propylene oxide block-adducts of alkylphenols. However) the method of this U.S. Patent relates to a washing method, while the 20'~630~
Present invention relates to a flotation method. Thus, the functions and properties of the deinking composition according to the present invention are quite different from those of the compositions used in the U. S. Patent. More specif ical ly, the U. S. patent relates to deinking compositions particularly suitable for washing methods which require low foaming abilities or low forming-inhibitory effects, while the deinking compositions of the present invention are designed such that they can ensure a stable operation during the flotation step and that they have appropriate foaming abilities.
DE-21439l2 likewise discloses a deinking method which uses a deinking composition obtained by adding ethylene oxide and propylene oxide to an alcohol or an alkylphenol to a desired extent and the flotation step is carried out at a temperature of not less than the clouding point of the deinking composition, but the method does not provide a nigh quality regenerated pulp having a high brightness and a low content of residual ink.
Japanese Unexamined Patent Publication (hereinafter referred to as ~~J. P. KOKAI") Nos. Sho 51-84905. Sho 53-31804> Sho 55-51891, Sho 55-51892 and Sho 56-79795 disclose deinking compositions comprising alkylene oxide adducts of alcohols or alkylphenols. However, these deinking compositions have foaming abilities higher than those required for each step and cannot ensure stable operations during flotation since the foaming leads to interruption of the deinking operation and a decrease in the yield of the deinking method. In addition) the deinking compositions do not exhibit sufficient abilities of trapping ink particles during the flotation and hence do not always provide high quality regenerated pulp having a high brightness and a low content of residual ink.
J.P. KOKAI No. Sho 61-41386 discloses the use of a composition comprising an alkylene oxide adduct of an alcohol and an ethylene oxide adduct of an alcohol, but the composition does not have an ability of trapping ink particles. The ethylene oxide adduct of alcohol used in this method rather has high ability of dispersing ink.
Therefore) the flotation method using this deinking composition cannot provide high quality regenerated pulp and stable operability.
J.P. KOKAI Nos. Sho 50-142804, Sho 61-186592, Sho 62-177291 and Sho 62-250291 disclose deinking compositions comprising alkylene oxide adducts of alcohols and higher fatty acids which can improve the ink-trapping properties of the alkylene oxide adducts of alcohols required for the flotation process. These compositions can improve the ink-trapping ability, but the use of these compositions makes it difficult to control foaming during flotation and to perform stable operation. J. P. KOKAI No. Sho 63-165591 discloses deinking compositions comprising alkylene oxide adducts of alcohols and alkylene oxide adducts of fatty acids for improving the ink-trapping ability of the alkylene oxide adducts of alcohols required for the flotation process. However, the use of these deinking compositions do not always provide stable operability during a deinking method in which a flotation process is included.
The deinking compositions disclosed in the foregoing German Patent and Japanese Unexamined Patent Publications do not always ensure stable operability and do not provide high quality regenerated 20'6308 pulp having a high brightness and a low content of residual ink, while the deinking composition provided by the present invention comprises a combination of two kinds of different specific deinking compositions which are designed such that they can ensure stable operation and can provide high quality regenerated pulp having a high brightness and a low content of residual ink. Moreover) the foregoing references do not disclose the influences of by-products simultaneously formed during the preparation of the deinking compositions on the deinking properties of the resulting deinking compositions.
Further Canadian Patent No. 729,071 discloses a deinking composition comprising an alkylphenol to which an alkylene oxide is added, but the deinking composition does not exhibit sufficient ink-trapping properties when it is used in the flotation method and cannot provide high quality regenerated pulp. In addition, it is not preferred from the viewpoint of protection of environment since alkylphenols are in general less biodegradable.
U. S. Patent Nos. 3, 021, 372; 2, 856, 434; 2, 903, 486; 3, 340, 309;
3, 444, 242 and 3, 625, 909 disclose compounds which are prepared by adding alkylene oxides to alcohols or alkylphenols, but these compounds quite differ) in structures and applications, from those of the present invention. U. S. Patent No. 4, l62> 186 also discloses a deinking composition, but the deinking composition comprises a combination of an oil-soluble alcohol ethoxylate with a water-soluble alcohol ethoxylate and completely differs from the deinking composition of the present invention.
TITLE OF THE INVENTION
Deinking Composition for Flotation and Deinking Method BACKGROUND OF THE INVENTION
The present invention relates to a deinking composition for reclaiming waste paper, which is used in the preparation of regenerated pulp from printed waste paper such as newspaper, magaaines, journals, wood-free paper, copying paper and computer printout paper and a method for using the deinking composition.
More specifically, the present invention relates to a deinking composition and a method of using the same, which are suitable for deinking printed waste paper through flotation, can provide high quality regenerated pulp having a high brightness and a low content of residual ink and can ensure a stable deinking operation.
There has long been known methods for reclaiming printed waste paper to give starting materials for paper-making. In particular, the reclaiming of printed waste paper has increasingly become important from the viewpoint of saving energy and natural resources as well as protection of environment and correspondingly there have been required for the development of techniques capable of providing high quality regenerated pulp having excellent properties such as a high brightness and a low content of residual ink.
In general, methods for deinking printed waste paper can roughly be divided into two groups, one of which is a washing method and the 20'6308 other of which is a flotation method. There have been known a variety of literatures and knowledges relating to these processing methods) deinking mechanisms and difference in quality between deinking compositions used in these processing methods. See, for instance, .5 Pulp & Paper, 1986, Nov. , p. 59; Pulp & Paper, 1989, Mar. , p. 60;
Pulp & Paper, I990) Mar. ) p. 76; Pulp & Paper, 1989, Mar. , p. 97;
Japanese Journal of Paper Technology. 1980, Aug., p. 37; 1989 TAPPI
Pulping Conference) p. 343; Japan TAPPI Journal, Vol. 36, p. 1029;
Japan TAPPI Journal) Vol. 39, p. 747; and U. S. Patent Nos. 4. 483) 74l and 4, 518) 459.
When summarizing literatures and, knowledges and experieneces which have been obtained through practical operations, the washing method in general comprises the step of repeatedly diluting and dehydrating a pulp slurry) or removing separated and dispersed ink particles from the pulp slurry through a screen or with a washing equipment such as a centrifugal cleaner. In this method) the separation of ink is greatly dependent upon, principally) mechanical conditions for due to washing equipments such as a press, a screen and a cleaner. Moreover, the washing method suffers from various problems concerning consumption of natural resources and energy since the use of a large amount of water is required. In addition, the washing method is greatly dependent upon mechanical factors and, therefore, workability of each step is regarded as important. In particular, when a composition having an intensive foaming ability, in particular, a deinking composition is employed) troubles due to foams arise in each equipment or process and this leads to reduction of workability and a marked increase in consumption of electric power. Thus, a composition having a low foaming ability or foaming-inhibitory properties must be used in the washing mehods. Further the separated ink particles must be fine and well dispersed in a pulp slurry in order to improve the efficiency of removing the separated ink.
On the other hand, the flotation method mainly comprises removing separated ink particles from a pulp slurry by adhering the ink particles to foams generated in a flotator. Thus) the mechanism of the removal of ink for the flotation method is completely different from that for the washing method and in other words, inks are principally removed through chemical processes unlike the washing method. The deinking method in which the flotation process is adopted sometimes comprises a so-called washing or dewatering step, but the separated ink particles are mainly removed in the flotation process.
The flotation method is advantageous in saving natural resources since the amount of water used in this method is smaller than that required for the washing method. To improve the effect of removing inks in the flotation method, the separated ink particles must be coagulated to form aggregates having a relatively large particle size.
Moreover, an appropriate foaming ability is required for the flotation process since the separated ink particles must be removed through the adhesion thereof to foams in the flotation method. This foaming ability required for the flotation method is higher than that required for the washing method. On the other hand. if the foaming ability of a composition, in particular, that of a deinking composition is too high, various problems arise. For instance, it is 20'6308 difficult to scrape out foams during the flotation process and various troubles due to foaming arise in each step. This leads to the interruption of the operation and the yield of pulp is reduced.
Accordingly, the deinking process cannot be carried out stably and it is sometimes difficult to obtain high quality regenerated pulp having a high brightness.
As has been discussed above in detail, the deinking mechanism for washing method is quite different from that for the flotation method and, therefore, they require the use of deinking compositions having different properties.
The flotation method has been adopted mainly in Japan and Europe because it can provide regenerated pulp having a brightness higher than that accomplished by the washing method and is excellent in saving in natural resources and energy as compared with the washing method. Moreover, the deinking method has recently been switched from the washing method to the flotation method likewise in the United States.
Until now, there have been filed a variety of patents relating to deinking compositions and methods for using the same. For instance, U. S. Patent No. 4, 518, 459 discloses a deinking method using a deinking composition obtained by adding a predetermined amount of propylene oxide to the terminal hydroxyl groups of alcohols or ethylene oxide adducts of alkylphenols, or by modifying, with benzyl ether, the terminal hydroxyl groups of alcohols or ethylene oxide- or ethylene oxide/propylene oxide block-adducts of alkylphenols. However) the method of this U.S. Patent relates to a washing method, while the 20'~630~
Present invention relates to a flotation method. Thus, the functions and properties of the deinking composition according to the present invention are quite different from those of the compositions used in the U. S. Patent. More specif ical ly, the U. S. patent relates to deinking compositions particularly suitable for washing methods which require low foaming abilities or low forming-inhibitory effects, while the deinking compositions of the present invention are designed such that they can ensure a stable operation during the flotation step and that they have appropriate foaming abilities.
DE-21439l2 likewise discloses a deinking method which uses a deinking composition obtained by adding ethylene oxide and propylene oxide to an alcohol or an alkylphenol to a desired extent and the flotation step is carried out at a temperature of not less than the clouding point of the deinking composition, but the method does not provide a nigh quality regenerated pulp having a high brightness and a low content of residual ink.
Japanese Unexamined Patent Publication (hereinafter referred to as ~~J. P. KOKAI") Nos. Sho 51-84905. Sho 53-31804> Sho 55-51891, Sho 55-51892 and Sho 56-79795 disclose deinking compositions comprising alkylene oxide adducts of alcohols or alkylphenols. However, these deinking compositions have foaming abilities higher than those required for each step and cannot ensure stable operations during flotation since the foaming leads to interruption of the deinking operation and a decrease in the yield of the deinking method. In addition) the deinking compositions do not exhibit sufficient abilities of trapping ink particles during the flotation and hence do not always provide high quality regenerated pulp having a high brightness and a low content of residual ink.
J.P. KOKAI No. Sho 61-41386 discloses the use of a composition comprising an alkylene oxide adduct of an alcohol and an ethylene oxide adduct of an alcohol, but the composition does not have an ability of trapping ink particles. The ethylene oxide adduct of alcohol used in this method rather has high ability of dispersing ink.
Therefore) the flotation method using this deinking composition cannot provide high quality regenerated pulp and stable operability.
J.P. KOKAI Nos. Sho 50-142804, Sho 61-186592, Sho 62-177291 and Sho 62-250291 disclose deinking compositions comprising alkylene oxide adducts of alcohols and higher fatty acids which can improve the ink-trapping properties of the alkylene oxide adducts of alcohols required for the flotation process. These compositions can improve the ink-trapping ability, but the use of these compositions makes it difficult to control foaming during flotation and to perform stable operation. J. P. KOKAI No. Sho 63-165591 discloses deinking compositions comprising alkylene oxide adducts of alcohols and alkylene oxide adducts of fatty acids for improving the ink-trapping ability of the alkylene oxide adducts of alcohols required for the flotation process. However, the use of these deinking compositions do not always provide stable operability during a deinking method in which a flotation process is included.
The deinking compositions disclosed in the foregoing German Patent and Japanese Unexamined Patent Publications do not always ensure stable operability and do not provide high quality regenerated 20'6308 pulp having a high brightness and a low content of residual ink, while the deinking composition provided by the present invention comprises a combination of two kinds of different specific deinking compositions which are designed such that they can ensure stable operation and can provide high quality regenerated pulp having a high brightness and a low content of residual ink. Moreover) the foregoing references do not disclose the influences of by-products simultaneously formed during the preparation of the deinking compositions on the deinking properties of the resulting deinking compositions.
Further Canadian Patent No. 729,071 discloses a deinking composition comprising an alkylphenol to which an alkylene oxide is added, but the deinking composition does not exhibit sufficient ink-trapping properties when it is used in the flotation method and cannot provide high quality regenerated pulp. In addition, it is not preferred from the viewpoint of protection of environment since alkylphenols are in general less biodegradable.
U. S. Patent Nos. 3, 021, 372; 2, 856, 434; 2, 903, 486; 3, 340, 309;
3, 444, 242 and 3, 625, 909 disclose compounds which are prepared by adding alkylene oxides to alcohols or alkylphenols, but these compounds quite differ) in structures and applications, from those of the present invention. U. S. Patent No. 4, l62> 186 also discloses a deinking composition, but the deinking composition comprises a combination of an oil-soluble alcohol ethoxylate with a water-soluble alcohol ethoxylate and completely differs from the deinking composition of the present invention.
20'76308 SUMMARY OF THE INVENTION
Accordingly, a primary object of the present invention is to provide a deinking composition exhibiting good deinking properties in the flotation method.
Another object of the present invention is to provide a deinking composition for regeneration of waste paper which can be used in a deinking method including a flotation step and can provide high quality regenerated pulp having a high brightness and a low content of residual ink and which can ensure stable operation of the deinking me t hod.
Another object of the present invention is to provide a flotation method for effectively deinking from waste paper.
Another object of the present invention is to provide a flotation method for effectively deinking from waste paper which can provide high quality regenerated pulp having a high brightness and a low content of residual ink and which can ensure stable operation.
These and other objects of the present invention will be apparent from the following description and Examples.
The present invention has been completed on the basis of the finding that the foregoing objects of the present invention can effectively be accomplished by simultaneously using, as a deinking composition, different monoalkyl ethers of ethylene oxide-propyelen oxide copolymers whose average-added molar number m of the propylene oxide and that n of the propylene oxide fall within specific ranges respectively and have structures different from one another and by 2A~A~o~
simultaneously using the deinking composition with a predetermined amount of a polyalkylene oxide.
According to one aspect of the present invention, there is provided a deinking composition for regeneration of waste paper by flotation, which comprises:
(1) 99.7 to 97$ by weight of a mixture comprising monoalkyl ethers of ethylene oxide/propylene oxide copolymers represented by the following general formulas (A) and (B) R10- (PO) nl- L (EO) m' (PO) n2~ -H (A) R20- (EO)ml- L (EO)m2~ (PO) n~ -H (B) wherein the averaged molar number m of the added ethylene oxide moieties ranges from 10 to 30, the averaged molar number n of the added propylene oxide moieties ranges from 8 to 35, R1 represents an alkyl group having 12 to 22 carbon atoms, R2 represents an alkyl group having 16 to 24 carbon atoms, m/(nl + n2) -0.5~1.5, (ml + m2)/n = 1. 12.0, provided that m (= ml +
m2) ranges from 10 to 30 and that n (= n1 + n2) ranges from 8 to 35, EO and PO represent ethylene oxide and propylene oxide units respectively, the EO and PO in the brackets being in the form of either a random or block configuration, and the mixing weight ratio of the compound (A) to the compound (B) ranging from 10:90 to 90:10; and (2) about 0.3 to about 3.0~ by weight of a polyalkylene oxide selected from the group consisting of polyethylene oxides, polypropylene oxides and ethylene oxide/propylene oxide copolymers.
According to another aspect of the invention, there is provided a deinking composition for regeneration of waste paper by flotation, which comprises:
(1) 99.7 to 97% by weight of a mixture comprising monoalkyl ethers of ethylene oxide/propylene oxide copolymers represented by the following general formulas (A-1 ) and (A-2 ) R30- (PO) n3- (EO) ma~ (PO) n4-H (A-1 ) R40- (PO) n5- [ (EO) ~~ (PO) n6l -H (A-2 ) wherein the averaged molar numbers ma and mb of the added ethylene oxide moieties each range from 10 to 30, the averaged molar numbers (n3 + n4) and (n5 + n6) of the added propylene oxide moieties each range from 8 to 35, R3 and R4 independently represent an alkyl group having 12 to 22 carbon atoms, ma/(n3 + n4) - 0. y1.5, mb/(n5 + n6) - 0. y1.5, EO and PO represent ethylene oxide and propylene oxide units respectively, (EO)ma~
(PO)n4 being in the form of a block configuration and [(EO)~~(PO)n6] being in the form of a random configuration, the mixing weight ratio of the compound (A-1) to the compound (A-2) ranging from 10:90 to 90:10; and >. ~~, -9a-(2) about 0.3 to about 3.Oo by weight of a polyalkylene oxide selected from the group consisting of polyethylene oxides, polypropylene oxides and ethylene oxide/propylene oxide copolymers.
According to a further aspect of the invention, there is also provided a flotation method for deinking printed waste paper, comprising the steps of defibering printed waste paper in the presence of a deinking composition as defined above to form a pulp slurry and then separating and removing separated ink particles from the pulp slurry through flotation.
-9b-20'~6~08 DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will hereinafter be explained in more detai 1.
The ether compounds represented by the foregoing general formula (A) comprise higher alcohols carrying alkyl groups having 12 to 22 carbon atoms to which propylene oxide units are added through the oxygen atom) have a ratio of the total added molar number of ethylene moieties to that of propylene oxide moieties (m/(nl + n2)) ranging from 0.5 to 1.5, preferably 0.5 to 0.9. These ether compounds have hydrophobicity higher than those of the conventional deinking compositions of higher alcohol type and thus have a strong affinity to separate ink particles and ink-trapping properties required for the flotation process. Therefore, the deinking composition of the present invention makes it possible to efficiently separate and remove) from pulp, ink particles separated during the flotation through the adhesion thereof to the generated foams of the deinking composition and to hence provide regenerated pulp having a high brightness. If the added molar number ratio exceeds 1.5, the hydrophilicity of the deinking composition increases, while the affinity of the composition to ink particles and ink-trapping properties thereof are lowered. As a result, any regenerated pulp having a high brightness cannot be obtained. On the other hand, if it is less than 0.5, the deinking composition exhibits a low foaming ability during the flotation step, it is difficult to scrape out foams during the flotation. Moreover) the deinking composition does not exhibit sufficient ink-trapping properties and thus regenerated pulp having a sufficient brightness cannot be obtained. In addition, if the added molar number ratio is controlled to a range of from 0.5 to 0.9) the ink-trapping properties of the deinking composition is further improved.
On the other hand, the ether compound represented by the foregoing general formula (B) comprises a higher alcohol to which ethylene oxide moieties are first added and the compound exhibits a desired effect when the ratio of the total added molar number of the ethylene oxide moieties to that of the propylene oxide moieties, (ml+m2)/n, ranges from 1.1 to 2Ø In particular, The compound (B) has a high affinity to printed ink on the surface of paper and excellent in ink-separation properties in particular in defibering and aging steps. If the ratio exceeds 2.0) excess foaming is caused during the flotation process and thus stable operation cannot be ensured. Further, it is difficult to sufficiently scrape out foams generated and to obtain regenerated pulp having a high brightness. On the other hand, if the ratio is less than 1.1. the resulting deinking composition does not have a sufficient affinity to printed ink on the surface of paper required for the defibering and aging steps. This leads to a decrease in the ink-separation properties and hence to the formation of only pulp having a high content of residual ink.
The compound of Formula (A) is prepared by first adding, to a higher alcohol, at least one, preferably 1 to 5 moles of propylene oxide to give a propylene oxide adduct of the higher alcohol and then adding ethylene oxide and propylene oxide in either a random or block configuration. When ethylene oxide and propylene oxide are added to a higher alcohol in a block configuration) it is preferred to first add ethylene oxide to the alcohol and then propylene oxide to the resulting adduct. Alternatively) the compound of Formula (A) can be prepared by adding) to a higher alcohol) at least one mole of propylene oxide) then randomly adding ethylene oxide and propylene oxide and further adding propylene oxide to the end of the product.
On the other hand, the compound represented by the foregoing general formula (B) can be prepared by first adding, to a higher alcohol) at least one mole) preferably 1 to 8 moles of ethylene oxide to give an ethylene oxide adduct of the higher alcohol and then adding ethylene oxide and propylene oxide to the adduct in either a random or block configuration. When the ethylene oxide and propylene oxide are added in a block configuration, it is preferred to first add ethylene oxide and then propylene oxide to the resulting ethylene oxide adduct. Alternatively, the compound of Formula (B) can also be prepared by directly adding ethylene oxide and propylene oxide to a higher alcohol in a random configuration. In this case, ethylene oxide would be first added to the higher alcohol selectively since the reactivity of ethylene oxide with the alcohol is greater than that of propylene oxide.
When preparing the foregoing ether compounds, it is very important in the present invention to control the water content of the reaction system to not more than 0.3~ and to add a catalyst, for instance) a basic catalyst such as sodium hydroxide or potassium hydroxide or a magnesium oxide-aluminum solid phase catalyst to the reaction system such that the amount of the catalyst is always maintained to not more than 0.25 with respect to an intermediate product or a final product in each alkylene oxide addition step in order to limit the content of by-products present in the final product such as polyethylene glycol, polypropylene glycol and polyalkylene glycols which are polymers of ethylene oxide and propylene oxide to about 0.3 to about 3~ by weight. However, the content of the polyalkylene glycol can subsequently be adjusted to the range defined above through supplementation of a desired polyalkylene glycol.
The higher alcohols, from which the alcohol residues: R10 of the compound (A) are derived, are those having 12 to 22) preferably 16 to 22 and more preferably 18 to 22 carbon atoms, while the higher alcohols) from which the alcohol residues: RZO of the compound (B) are derived) are those having 16 to 24, preferably 18 to 22 carbon atoms.
Specific examples of such higher alcohols include lauryl alcohol, myristyl alcohol, palmityl alcohol, heptadecanol, stearyl alcohol) nonadecanol, arachidic alcohol, behenyl alcohol, tricosanol, tetracosanol, oleyl alcohol, alcohols derived from animal and plant oil fatty acids such as tallow oil alcohol, fish oil alcohol, lard alcohol and hardened products thereof.
It is important requirements for the deinking composition that the composition has a total molar number of the added ethylene oxide moieties ranging from IO to 30 moles, preferably 12 to 28 moles per mole of a higher alcohol expressed in terms of the charged molar number thereof and a total molar number of the added propylene oxide moieties ranging from 8 to 35 moles) preferably 9 to 30 moles per mole of a higher alcohol expressed in terms of the charged molar number thereof) that the ratio of the total molar number of the added 2fl'~~~08 ethylene oxide to the total molar number of the added propylene oxide ranges from 0.5 to 1.5) preferably 0.5 to 0.9 for the compound of Formula (A) or 1.1 to 2.0 for the compound of Formula (B) and that the carbon atom number of the alkyl group ranges from 12 to 22 for the compound of Formula (A) or 16 to 24 for the compound of Formula (B).
If the carbon atom numbers of the alkyl groups of these higher alcohols are smaller than each corresponding lower limit, the resulting compound has insufficient hydrophobicity because of short chain length of the alkyl group, the foaming ability thereof is correspondingly insufficient even if the molar numbers of added ethylene oxide and propylene oxide fall within the ranges defined above respectively, the ink-trapping ability thereof during flotation is likewise insufficient and separated ink particles are not sufficiently adhered to foams generated by the compound. Thus, high quality regenerated pulp having a high brightness cannot be obtained.
On the other hand) if the length of the alkyl group is longer than the upper limit defined above, the deinking composition is not sufficiently dissolved and dispersed in a medium during defibering and accordingly high quality regenerated pulp having a high brightness and a low content of remaining ink cannot be produced.
Further if the molar numbers of added ethylene oxide and propylene oxide as well as the ratio of the total molar number of the added ethylene oxide to the total molar number of the added propylene oxide are outside the foregoing corresponding ranges, the formation of high quality regenerated pulp and stable operation of the deinking treatment cannot be ensured even if the carbon atom numbers of the 2p'~630g alkyl groups of the compounds of Formulas (A) and (li) fall within the ranges defined above.
Furthermore, it is also important reQuirements, when preparing the compounds, i.e., adding alkylene oxide to higher alcohols, that the reaction system is sufficiently purged with nitrogen gas and dehydrated at a high temperature under reduced pressure to control the water content to about 0.396 or less by weight prior to the addition of the alkylene oxide and that, upon preparing the ether compounds of Formulas (A) and (B), the amount of the catalyst is always maintained to not more than 0.2596 with respect to an intermediate product or a final product in each alkylene oxide addition step, in order to limit the content of by-products present in the final product such as polyethylene glycol, polypropylene glycol and polyalkylene glycols which are polymers of ethylene oxide and propylene oxide to about 0.3 to about 3~ by weight.
The amounts of water and catalyst greatly affect the amount of by-products, in particular polyethylene glycol, polypropylene glycol and polyalkylene glycols which are polymers of ethylene oxide and propylene oxide present in the final product as described in Journal of Japan Oi 1 Chemist' s Society. 1979, 28. p. 88l. Therefore, the control of the amounts of water and catalyst is an essential re9uirement for limiting the amount of the by-products formed during the preparation of these ether compounds to a range of from about 0.3 to about 396 by weight.
The amount of these by-products should be limited to the range defined above for the following reason: polyethylene glycol, polypropylene glycol and polyalkylene glycols are well-known as compounds having high dispersion properties and foaming ability and, therefore, if they are present in an amount of more than about 3% by weight) they serve to disperse inks and strengthen the foaming ability during flotation. In particular, the use thereof adversely affect the flotation method which requires good ink-trapping properties and an appropriate foaming ability. Since these by-products do not have hydrophobic groups such as alkyl groups, they do not exhibit ink-trapping ability at all and accordingly) they do not serve to remove ink particles separated during the flotation from a pulp slurry. On the other hand) if the amount of these by-products is less than about 0.3% by weight) the resulting deinking composition does not exhibit an appropriate foaming ability during the flotation, the separated ink particles are not sufficiently trapped by the foams and thus regenerated pulp having a high brightness cannot be obtained.
In the deinking process which is usually employed and comprises defibering and/or aging steps. the deinking composition of the present invention can be used by adding) in portions, to either or both of the defibering and aging steps.
In order to obtain high quality regenerated pulp, the deinking composition of the present invention should be added to a defibering step (or an equipment, pulper). Alternatively, to obtain a regenerated pulp having higher quality, the deinking process preferably comprises an aging step after the defibering step. The deinking composition may be added, in portions, to either or both of these defibering and aging steps, but is preferably added, in portions, to both of these defibering and aging steps.
As has already been discussed above, the deinking process can roughly be divided into two groups) i.e., a washing method and a flotation method. The deinking method in general comprises defibering, aging and washing or flotation steps. The defibering and aging steps are performed for separating ink printed on the surface of paper and finely dispersing the separated ink particles. Moreover, the washing step is carried out while the ink particles are dispersed as has been described above, but in the flotation step, the ink particles dispersed in a slurry must be coagulated during the defibering and aging steps. In other words, the washing step and the aging step require dispersed conditions of ink particles which oppose to each other. Accordingly, the deinking composition used in the flotation step must have abilities of separating and dispersing ink and an ability of coagulating the dispersed ink particles and these properties are opposed to one another. On the other hand, deinking composition required for three steps: defibering, aging and washing steps in the washing method may have the same properties.
However, the foregoing problems can be solved by the use of two different kinds of deinking compositions (A) and (B) according to the present invention.
The amount of the deinking composition of the present invention to be added to each of the defibering and aging steps ranges from 0.10 to 2~, preferably 0.15 to 1~ on the basis of th weight of waste paper.
ThIS 1S because if the amount is less than the lower limit, high quality regenerated pulp having a high brightness cannot be obtained, the foaming ability achieved is insufficient and ink particles are not satisfactorily removed during the flotation, while if the amount exceeds the upper limit) foaming during the flotation is too severe to ensure stable operation. In this respect) if the deinking composition is added to both defibering and aging steps, the total amount thereof to be added to these steps ranges from 0.1 to 2.l96 by weight, preferably 0.15 to 1.5~ by weight.
When deinking is carried out using the deinking composition of the invention, the defibering step is preferably performed at a pulp concentration ranging from 4 to 2596, a temperature ranging from 20 to 70°C in the presence of an alkaline agent such as sodium hydroxide) sodium silicate or sodium carbonate (pH = 7.5 to 1l.5) preferably 8.0 to 11.5) and optionally a bleaching agent such as hydrogen peroxide in addition to the deinking composition of the present invention. If the pulp concentration is less than 496 or the temperature is less than 20 °C) the amount of undefibrated pulp increases since the frictional force between pulp fibers during defibering is low and the content of ink in the pulp increases. Thus) the resulting regenerated pulp cannot be used as starting material for paper-making. On the other hand) the pulp concentration exceeds 259o or the temperature is higher than 70 °C, high quality regenerated pulp cannot be obtained since the frictional force between pulp fibers is extremely high and the strength of the resulting regenerated pulp is reduced due to frictional heat. Further) if the pH value during the defibering is less than 7.5, the degree of swelling of the pulp fibers during the defibering is low and accordingly the content of undefibrated fibers 20~6~0g increases, the content of ink in the pulp increases and, therefore) high Quality regenerated pulp cannot be prepared. Thus, the resulting regenerated pulp cannot be used as starting material for paper-making.
If the pH value exceeds l1.5. the resulting pulp causes yellowing by alkali baking, thereby the reduction of brightness occurs, and the strength of the resulting reclaimed paper is accordingly lowered.
The aging step may be carried out employing the same compositions used in the defibering step. The aging step is preferably performed at a pulp concentration ranging from 10 to 30%.
a temprature ranging from 30 to 80°C for at least one hour. If the pulp concentration is less than 10% and the temperature is lower than 30 °C, a sufficient aging effect cannot be ensured and accordingly high Quality regenerated pulp cannot be obtained. If the temperature exceeds 80 °C, the strength of the resulting reclaimed paper is lowered due to the effect of heat. Moreover, any significant aging effect cannot be anticipated even if the pulp concentration is increased to more than 30%. If pH for the aging step is lower than 8, any desired aging effect is not ensured. On the other hand, if the pH
value exceeds 12) the resulting pulp causes Yellowing due to the alkali baking and hence the brightness of the resulting pulp is impaired. Further) the strength of the resulting reclaimed paper is likewise lowered.
The separated ink can effectively be removed from the pulp slurry through the flotation performed at a pulp concentration of 0.5 to 1.5% and a temperature of 20 to 45°C.
The deinking method of the present invention may further 207~30~
comprise various steps commonly used in the deinking method such as dilution and/or dewatering steps, a screening step and treatments with a disperser and/or kneader without any influence on the quality of the resulting regenerated pulp and the operability of the method.
In addition, the deinking composition of the present invention may likewise be added to an ink-separation step, for instance) to a kneader, a refiner and/or a disperser, in addition to the foregoing defibering and aging steps.
If the deinking composition of the present invention is used in the deinking step of the washing method, stable operation without accompanying any trouble due to foaming can be ensured and high quality regenerated pulp having a high brightness and a low content of remaining ink unlike the usual methods and those disclosed in known patents in which ethylene oxide/propylene oxide adducts of higher alcohols are used.
The deinking composition of the present invention can be used simultaneous with polyoxyalkylene alkyl ether sulfates. fatty acids or salts thereof and/or alkylene oxide adducts of rosin.
As has been explained above in detail, if the deinking composition of the present invention is used in the flotation method, excellent deinking effect can be anticipated and high quality regenerated pulp having a high brightness and a low content of remaining ink can be obtained. In particular, according to the present invention, an increase in the brightness of the resulting reclaimed paper of at least one rank higher than that observed for the conventional method can be achieved and the content of remaining ink is at least 25% lower than that observed when the compounds (A) and (B) are not simultaneously employed. Thus, the resulting reclaimed paper has a substantially improved brightness which can be recognized even with the naked eyes.
The present invention will hereinafter be explained in more detail with reference to the following Preparation Examples and non-limitative working Examples and the effects practically accomplished by the present invention will also be discussed in detail in comparison with Comparative Examples.
Preparation Example 1 After charging 108.2 g (0.4 mole) of stearyl alcohol and 1.01 g (0.20 with respect to the final product) of KOH as a catalyst to an autoclave of stainless steel, the reaction system was sufficiently purged with nitrogen gas. Then the reaction system was sufficiently dehydrated at 135 ~ 5 °C for 0.5 hour under reduced pressure and 2l1.2 g (4.8 moles) of ethylene oxide was gradually added to the reaction system while maintaining the temperature and pressure at 125 ~ 5 °C
and 1.0 to 3.0 kg/cmz, respectively. After completion of the addition, 2o the reaction system was matured at the reaction temperature for 2 hours and the unreacted ethylene oxide was removed under reduced pressure. Subsequently, 185.6 g (3.2 moles) of propylene oxide was gradually added while maintaining the temperature and pressure at l10 i--5 °C and 1.0 to 3.0 kg/cm2) respectively. After completion of the addition, the reaction system was matured at the reaction temperature for 2 hours and the unreacted propylene oxide was removed under 20'6308 reduced pressure. Then acetic acid was added to adjust the pH of the reaction system to 6 to 8 (Sample 1).
The same procedures used above were repeated except that the conditions listed in Table 1 were used to give Samples 2 and 3.
Preparation Example 2 After charging l08.2 g (0.4 mole) of stearyl alcohol and l.27 g (0.2% with respect to the final product) of KOH as a catalyst to an autoclave of stainless steel, the reaction system was sufficiently to purged with nitrogen gas. Then the reaction system was sufficiently dehydrated at 120°C for 2.0 hours under reduced pressure and 35.2 g (0.8 mole) of ethylene oxide was gradually added to the reaction system while maintaining the temperature and pressure at 175 ~ 5 °C and 1.0 to 3.0 kg/cmz, respectively. After completion of the addition, the reaction system was matured at the reaction temperature for 2 hours and the unreacted ethylene oxide was removed under reduced pressure. Subsequently, a mixture comprising 28l.6 g (6.4 moles) of ethylene oxide and 208 g (3.6 moles) of propylene oxide was gradually added while maintaining the temperature and pressure at 120~ 5 °C and 1.0 to 3.0 kg/cm2, respectively. After completion of the addition, the reaction system was matured at the reaction temperature for 2 hours and the unreacted ethylene oxide and propylene oxide were removed under reduced pressure. Then the reaction mixture was cooled, 0.18 g (0.20% with respect to the final product) of KOH as a catalyst was additionally supplemented, the reaction system was sufficiently purged with nitrogen gas. Thereafter the reaction system was 20'~630~
sufficiently dehydrated at 120 ~ 5 °C for 2 hours under reduced pressure and 92.8 g (1.6 mole) of propylene oxide was gradually .added to the reaction system while maintaining the temperature and pressure at 115 ~5 °C and 1.0 to 3.0 kg/cm2, respectively. After completion of the addition, the unreacted propylene oxide was removed under reduced pressure, followed by cooling and addition of acetic acid to adjust the pH of the reaction system to 6 to 8 (Sample 4).
The same procedures used above were repeated except that propylene oxide was added after randomly adding, in advance, ethylene oxide and propylene oxide under the conditions listed in Table 1 to give Sample 5.
Table l: RO ~(EO)- ((EO)(PO)) H (Component (B)) Sample Alkyl Group Total ((EO)(PO)) EO/PO By-product No. (ratio: wt96) E0; PO Conf ig. (96) 1 Cls 12; 8 block 1.50 1.25 2 C1$/Cz2=70:30 18; 9 block 2.00 2.l5 3 C1 6/C18=40/60 18; 16 random 1. 13 1. 15 4 Cls 18; 10 random, block *' 1.80 2.25 5 (16/C,$=30/70 16; 13 random, block *' 1.23 2.15 ~1: Ethylene oxide and propylene oxide are randomly added and then propylene oxide is further added.
Terminal added PO molar numbers are 4 for Sample 4 and 5 for Samp 1 a 5.
Preparation Example 3 20'6308 After charging l08.2 g (0.4 mole) of stearyl alcohol and 1.20 g (0.18°6 with respect to propylene oxide (1 mole) adduct of stearyl alcohol) of KOH as a catalyst to an autoclave, the reaction system was sufficiently purged with nitrogen gas: Then the reaction system was sufficiently dehydrated at 140 ~ 5 °C for one hour under reduced pressure and 23a2 g (0.4 moles) of propylene oxide was gradually added to the reaction system while maintaining the temperature and pressure at 115 ~5 °C and 1.0 to 3.0 kg/cm2, respectively. After completion of the addition) the reaction system was matured at the reaction temperature for 2 hours and the unreacted propylene oxide was removed under reduced pressure. Subsequently) the reaction system was cooled, 0.3 g (total amount of the catalyst with respect to the final product:
0.200 of KOH was additionally supplemented) the reaction system was sufficiently purged with nitrogen gas, a mixture comprising l76 g (4 moles) of ethylene oxide and 440.8 g (7.6 moles) of propylene oxide was gradually added while maintaining the temperature and pressure at 120~5 °C and 1.0 to 3.0 kg/cm2, respectively. After completion of the' addition, the reaction system was matured, the unreacted ethylene oxide and propylene oxide were removed under reduced pressure, followed by cooling and addition of acetic acid to adjust the pH of the reaction system to 6 to 8 (Sample 6).
The same procedures used above were repeated except that the conditions listed in Table 1 were adopted to give Samples 7, 10 and 11. When the added ethylene oxide and propylene oxide were in the block configuration, ethylene oxide was first added and then propylene oxide was added.
20'~6~08 Preparation Example 4 After charging 108.2 g (0.4 mole) of stearyl alcohol and 1.67 g (0.23 with respect to propylene oxide (5 moles)~ ethylene oxide (15 moles)~propylene oxide (10 moles) adduct of stearyl alcohol) of KOH
as a catalyst to an autoclave, the reaction system was sufficiently purged with nitrogen gas. Then the reaction system was sufficiently dehydrated at 125 ~ 5 °C for 1.5 hour under reduced pressure and 1l6 g (2 moles) of propylene oxide was gradually added to the reaction system while maintaining the temperature and pressure at 115 ~ 5 °C and 1.0 to 3.0 kg/cm2, respectively. After completion of the addition, the reaction system was matured at the reaction temperature for 2 hours and the unreacted propylene oxide was removed. Subsequently, a mixture comprising 270 g (6.1 moles) of ethylene oxide and 232 g (4 moles) of propylene oxide was gradually added while maintaining the temperature and pressure at l15~ 5 °C and 1. 0 to 3. 0 kg/cm2, respectively. After completion of the addition, the reaction system was' matured and the unreacted ethylene oxide and propylene oxide were removed. Then the reaction mixture was cooled) 0.44 g (total amount of the catalyst: 0.25 with respect to the final product) of KOH as a catalyst was additionally supplemented, the reaction system was sufficiently purged with nitrogen gas and sufficiently dehydrated at a high temperature under reduced pressure. Then 116 g (2 moles) of propylene oxide was gradually added to the reaction system while maintaining the temperature and pressure at 1l5 ~ 5 °C and 1.0 to 3.0 kg/cm2, respectively. After completion of the addition) the reaction ~U7fi348 system was matured, the unreacted propylene oxide was removed) followed by cooling and addition of acetic acid to adjust the pH of the reaction system to 6 to 8 (Sample 8).
The same procedures used above were repeated except that the conditions listed in Table 2 were used to give Sample 9.
Table 2: RO (PO) m ((EO)m (PO)n2) (Component(A)) - H
Samp le Alkyl Group nl, m) ((EO)(PO)) EO/PO -product By No. (ratio: wt~) n2 Config. (96) 6 C, g l) 10, random 0. 50 1. 53 7 C~ s/C, 8=30/703, 16, block 0. 67 2. 30 8 C, a 5, 15, random, block 0. 75 2. 53 15 *' 9 C, g /C 2 2 7, 18, d i t t o 0. 86 2. 85 =70 : 30 14 10 C, a 2) 18, b 1 ock 1. 50 2. 34 11 C, s /C 1 a 3, 18, b I ock 1. 20 2. 45 =20/80 12 ~1: Ethylene ropylene oxide randomly added oxide and p are and then propylene oxideis furtheradded.
Terminal added PO molar numbers are 5 Sample and 6 for 8 for Samp 1 a 9.
Comparative Preparation Example 1 The same procedures used in Preparation Example 1 except that ethylene oxide (18 moles) and propylene oxide (18 moles) were added to stearyl alcohol (1 mole) in a block configuration so that the ratio of the total molar number of the added ethylene oxide to the total molar number of the added propylene oxide was e9ua1 to 1 to give 2o~6vo~
Sample 12.
Table 3: RO ~ (EO)-[(EO)(PO)]H
Sample Alkyl Total C(EO)(P0)] EO/PO By-product No. Group E0; PO Config.
Accordingly, a primary object of the present invention is to provide a deinking composition exhibiting good deinking properties in the flotation method.
Another object of the present invention is to provide a deinking composition for regeneration of waste paper which can be used in a deinking method including a flotation step and can provide high quality regenerated pulp having a high brightness and a low content of residual ink and which can ensure stable operation of the deinking me t hod.
Another object of the present invention is to provide a flotation method for effectively deinking from waste paper.
Another object of the present invention is to provide a flotation method for effectively deinking from waste paper which can provide high quality regenerated pulp having a high brightness and a low content of residual ink and which can ensure stable operation.
These and other objects of the present invention will be apparent from the following description and Examples.
The present invention has been completed on the basis of the finding that the foregoing objects of the present invention can effectively be accomplished by simultaneously using, as a deinking composition, different monoalkyl ethers of ethylene oxide-propyelen oxide copolymers whose average-added molar number m of the propylene oxide and that n of the propylene oxide fall within specific ranges respectively and have structures different from one another and by 2A~A~o~
simultaneously using the deinking composition with a predetermined amount of a polyalkylene oxide.
According to one aspect of the present invention, there is provided a deinking composition for regeneration of waste paper by flotation, which comprises:
(1) 99.7 to 97$ by weight of a mixture comprising monoalkyl ethers of ethylene oxide/propylene oxide copolymers represented by the following general formulas (A) and (B) R10- (PO) nl- L (EO) m' (PO) n2~ -H (A) R20- (EO)ml- L (EO)m2~ (PO) n~ -H (B) wherein the averaged molar number m of the added ethylene oxide moieties ranges from 10 to 30, the averaged molar number n of the added propylene oxide moieties ranges from 8 to 35, R1 represents an alkyl group having 12 to 22 carbon atoms, R2 represents an alkyl group having 16 to 24 carbon atoms, m/(nl + n2) -0.5~1.5, (ml + m2)/n = 1. 12.0, provided that m (= ml +
m2) ranges from 10 to 30 and that n (= n1 + n2) ranges from 8 to 35, EO and PO represent ethylene oxide and propylene oxide units respectively, the EO and PO in the brackets being in the form of either a random or block configuration, and the mixing weight ratio of the compound (A) to the compound (B) ranging from 10:90 to 90:10; and (2) about 0.3 to about 3.0~ by weight of a polyalkylene oxide selected from the group consisting of polyethylene oxides, polypropylene oxides and ethylene oxide/propylene oxide copolymers.
According to another aspect of the invention, there is provided a deinking composition for regeneration of waste paper by flotation, which comprises:
(1) 99.7 to 97% by weight of a mixture comprising monoalkyl ethers of ethylene oxide/propylene oxide copolymers represented by the following general formulas (A-1 ) and (A-2 ) R30- (PO) n3- (EO) ma~ (PO) n4-H (A-1 ) R40- (PO) n5- [ (EO) ~~ (PO) n6l -H (A-2 ) wherein the averaged molar numbers ma and mb of the added ethylene oxide moieties each range from 10 to 30, the averaged molar numbers (n3 + n4) and (n5 + n6) of the added propylene oxide moieties each range from 8 to 35, R3 and R4 independently represent an alkyl group having 12 to 22 carbon atoms, ma/(n3 + n4) - 0. y1.5, mb/(n5 + n6) - 0. y1.5, EO and PO represent ethylene oxide and propylene oxide units respectively, (EO)ma~
(PO)n4 being in the form of a block configuration and [(EO)~~(PO)n6] being in the form of a random configuration, the mixing weight ratio of the compound (A-1) to the compound (A-2) ranging from 10:90 to 90:10; and >. ~~, -9a-(2) about 0.3 to about 3.Oo by weight of a polyalkylene oxide selected from the group consisting of polyethylene oxides, polypropylene oxides and ethylene oxide/propylene oxide copolymers.
According to a further aspect of the invention, there is also provided a flotation method for deinking printed waste paper, comprising the steps of defibering printed waste paper in the presence of a deinking composition as defined above to form a pulp slurry and then separating and removing separated ink particles from the pulp slurry through flotation.
-9b-20'~6~08 DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will hereinafter be explained in more detai 1.
The ether compounds represented by the foregoing general formula (A) comprise higher alcohols carrying alkyl groups having 12 to 22 carbon atoms to which propylene oxide units are added through the oxygen atom) have a ratio of the total added molar number of ethylene moieties to that of propylene oxide moieties (m/(nl + n2)) ranging from 0.5 to 1.5, preferably 0.5 to 0.9. These ether compounds have hydrophobicity higher than those of the conventional deinking compositions of higher alcohol type and thus have a strong affinity to separate ink particles and ink-trapping properties required for the flotation process. Therefore, the deinking composition of the present invention makes it possible to efficiently separate and remove) from pulp, ink particles separated during the flotation through the adhesion thereof to the generated foams of the deinking composition and to hence provide regenerated pulp having a high brightness. If the added molar number ratio exceeds 1.5, the hydrophilicity of the deinking composition increases, while the affinity of the composition to ink particles and ink-trapping properties thereof are lowered. As a result, any regenerated pulp having a high brightness cannot be obtained. On the other hand, if it is less than 0.5, the deinking composition exhibits a low foaming ability during the flotation step, it is difficult to scrape out foams during the flotation. Moreover) the deinking composition does not exhibit sufficient ink-trapping properties and thus regenerated pulp having a sufficient brightness cannot be obtained. In addition, if the added molar number ratio is controlled to a range of from 0.5 to 0.9) the ink-trapping properties of the deinking composition is further improved.
On the other hand, the ether compound represented by the foregoing general formula (B) comprises a higher alcohol to which ethylene oxide moieties are first added and the compound exhibits a desired effect when the ratio of the total added molar number of the ethylene oxide moieties to that of the propylene oxide moieties, (ml+m2)/n, ranges from 1.1 to 2Ø In particular, The compound (B) has a high affinity to printed ink on the surface of paper and excellent in ink-separation properties in particular in defibering and aging steps. If the ratio exceeds 2.0) excess foaming is caused during the flotation process and thus stable operation cannot be ensured. Further, it is difficult to sufficiently scrape out foams generated and to obtain regenerated pulp having a high brightness. On the other hand, if the ratio is less than 1.1. the resulting deinking composition does not have a sufficient affinity to printed ink on the surface of paper required for the defibering and aging steps. This leads to a decrease in the ink-separation properties and hence to the formation of only pulp having a high content of residual ink.
The compound of Formula (A) is prepared by first adding, to a higher alcohol, at least one, preferably 1 to 5 moles of propylene oxide to give a propylene oxide adduct of the higher alcohol and then adding ethylene oxide and propylene oxide in either a random or block configuration. When ethylene oxide and propylene oxide are added to a higher alcohol in a block configuration) it is preferred to first add ethylene oxide to the alcohol and then propylene oxide to the resulting adduct. Alternatively) the compound of Formula (A) can be prepared by adding) to a higher alcohol) at least one mole of propylene oxide) then randomly adding ethylene oxide and propylene oxide and further adding propylene oxide to the end of the product.
On the other hand, the compound represented by the foregoing general formula (B) can be prepared by first adding, to a higher alcohol) at least one mole) preferably 1 to 8 moles of ethylene oxide to give an ethylene oxide adduct of the higher alcohol and then adding ethylene oxide and propylene oxide to the adduct in either a random or block configuration. When the ethylene oxide and propylene oxide are added in a block configuration, it is preferred to first add ethylene oxide and then propylene oxide to the resulting ethylene oxide adduct. Alternatively, the compound of Formula (B) can also be prepared by directly adding ethylene oxide and propylene oxide to a higher alcohol in a random configuration. In this case, ethylene oxide would be first added to the higher alcohol selectively since the reactivity of ethylene oxide with the alcohol is greater than that of propylene oxide.
When preparing the foregoing ether compounds, it is very important in the present invention to control the water content of the reaction system to not more than 0.3~ and to add a catalyst, for instance) a basic catalyst such as sodium hydroxide or potassium hydroxide or a magnesium oxide-aluminum solid phase catalyst to the reaction system such that the amount of the catalyst is always maintained to not more than 0.25 with respect to an intermediate product or a final product in each alkylene oxide addition step in order to limit the content of by-products present in the final product such as polyethylene glycol, polypropylene glycol and polyalkylene glycols which are polymers of ethylene oxide and propylene oxide to about 0.3 to about 3~ by weight. However, the content of the polyalkylene glycol can subsequently be adjusted to the range defined above through supplementation of a desired polyalkylene glycol.
The higher alcohols, from which the alcohol residues: R10 of the compound (A) are derived, are those having 12 to 22) preferably 16 to 22 and more preferably 18 to 22 carbon atoms, while the higher alcohols) from which the alcohol residues: RZO of the compound (B) are derived) are those having 16 to 24, preferably 18 to 22 carbon atoms.
Specific examples of such higher alcohols include lauryl alcohol, myristyl alcohol, palmityl alcohol, heptadecanol, stearyl alcohol) nonadecanol, arachidic alcohol, behenyl alcohol, tricosanol, tetracosanol, oleyl alcohol, alcohols derived from animal and plant oil fatty acids such as tallow oil alcohol, fish oil alcohol, lard alcohol and hardened products thereof.
It is important requirements for the deinking composition that the composition has a total molar number of the added ethylene oxide moieties ranging from IO to 30 moles, preferably 12 to 28 moles per mole of a higher alcohol expressed in terms of the charged molar number thereof and a total molar number of the added propylene oxide moieties ranging from 8 to 35 moles) preferably 9 to 30 moles per mole of a higher alcohol expressed in terms of the charged molar number thereof) that the ratio of the total molar number of the added 2fl'~~~08 ethylene oxide to the total molar number of the added propylene oxide ranges from 0.5 to 1.5) preferably 0.5 to 0.9 for the compound of Formula (A) or 1.1 to 2.0 for the compound of Formula (B) and that the carbon atom number of the alkyl group ranges from 12 to 22 for the compound of Formula (A) or 16 to 24 for the compound of Formula (B).
If the carbon atom numbers of the alkyl groups of these higher alcohols are smaller than each corresponding lower limit, the resulting compound has insufficient hydrophobicity because of short chain length of the alkyl group, the foaming ability thereof is correspondingly insufficient even if the molar numbers of added ethylene oxide and propylene oxide fall within the ranges defined above respectively, the ink-trapping ability thereof during flotation is likewise insufficient and separated ink particles are not sufficiently adhered to foams generated by the compound. Thus, high quality regenerated pulp having a high brightness cannot be obtained.
On the other hand) if the length of the alkyl group is longer than the upper limit defined above, the deinking composition is not sufficiently dissolved and dispersed in a medium during defibering and accordingly high quality regenerated pulp having a high brightness and a low content of remaining ink cannot be produced.
Further if the molar numbers of added ethylene oxide and propylene oxide as well as the ratio of the total molar number of the added ethylene oxide to the total molar number of the added propylene oxide are outside the foregoing corresponding ranges, the formation of high quality regenerated pulp and stable operation of the deinking treatment cannot be ensured even if the carbon atom numbers of the 2p'~630g alkyl groups of the compounds of Formulas (A) and (li) fall within the ranges defined above.
Furthermore, it is also important reQuirements, when preparing the compounds, i.e., adding alkylene oxide to higher alcohols, that the reaction system is sufficiently purged with nitrogen gas and dehydrated at a high temperature under reduced pressure to control the water content to about 0.396 or less by weight prior to the addition of the alkylene oxide and that, upon preparing the ether compounds of Formulas (A) and (B), the amount of the catalyst is always maintained to not more than 0.2596 with respect to an intermediate product or a final product in each alkylene oxide addition step, in order to limit the content of by-products present in the final product such as polyethylene glycol, polypropylene glycol and polyalkylene glycols which are polymers of ethylene oxide and propylene oxide to about 0.3 to about 3~ by weight.
The amounts of water and catalyst greatly affect the amount of by-products, in particular polyethylene glycol, polypropylene glycol and polyalkylene glycols which are polymers of ethylene oxide and propylene oxide present in the final product as described in Journal of Japan Oi 1 Chemist' s Society. 1979, 28. p. 88l. Therefore, the control of the amounts of water and catalyst is an essential re9uirement for limiting the amount of the by-products formed during the preparation of these ether compounds to a range of from about 0.3 to about 396 by weight.
The amount of these by-products should be limited to the range defined above for the following reason: polyethylene glycol, polypropylene glycol and polyalkylene glycols are well-known as compounds having high dispersion properties and foaming ability and, therefore, if they are present in an amount of more than about 3% by weight) they serve to disperse inks and strengthen the foaming ability during flotation. In particular, the use thereof adversely affect the flotation method which requires good ink-trapping properties and an appropriate foaming ability. Since these by-products do not have hydrophobic groups such as alkyl groups, they do not exhibit ink-trapping ability at all and accordingly) they do not serve to remove ink particles separated during the flotation from a pulp slurry. On the other hand) if the amount of these by-products is less than about 0.3% by weight) the resulting deinking composition does not exhibit an appropriate foaming ability during the flotation, the separated ink particles are not sufficiently trapped by the foams and thus regenerated pulp having a high brightness cannot be obtained.
In the deinking process which is usually employed and comprises defibering and/or aging steps. the deinking composition of the present invention can be used by adding) in portions, to either or both of the defibering and aging steps.
In order to obtain high quality regenerated pulp, the deinking composition of the present invention should be added to a defibering step (or an equipment, pulper). Alternatively, to obtain a regenerated pulp having higher quality, the deinking process preferably comprises an aging step after the defibering step. The deinking composition may be added, in portions, to either or both of these defibering and aging steps, but is preferably added, in portions, to both of these defibering and aging steps.
As has already been discussed above, the deinking process can roughly be divided into two groups) i.e., a washing method and a flotation method. The deinking method in general comprises defibering, aging and washing or flotation steps. The defibering and aging steps are performed for separating ink printed on the surface of paper and finely dispersing the separated ink particles. Moreover, the washing step is carried out while the ink particles are dispersed as has been described above, but in the flotation step, the ink particles dispersed in a slurry must be coagulated during the defibering and aging steps. In other words, the washing step and the aging step require dispersed conditions of ink particles which oppose to each other. Accordingly, the deinking composition used in the flotation step must have abilities of separating and dispersing ink and an ability of coagulating the dispersed ink particles and these properties are opposed to one another. On the other hand, deinking composition required for three steps: defibering, aging and washing steps in the washing method may have the same properties.
However, the foregoing problems can be solved by the use of two different kinds of deinking compositions (A) and (B) according to the present invention.
The amount of the deinking composition of the present invention to be added to each of the defibering and aging steps ranges from 0.10 to 2~, preferably 0.15 to 1~ on the basis of th weight of waste paper.
ThIS 1S because if the amount is less than the lower limit, high quality regenerated pulp having a high brightness cannot be obtained, the foaming ability achieved is insufficient and ink particles are not satisfactorily removed during the flotation, while if the amount exceeds the upper limit) foaming during the flotation is too severe to ensure stable operation. In this respect) if the deinking composition is added to both defibering and aging steps, the total amount thereof to be added to these steps ranges from 0.1 to 2.l96 by weight, preferably 0.15 to 1.5~ by weight.
When deinking is carried out using the deinking composition of the invention, the defibering step is preferably performed at a pulp concentration ranging from 4 to 2596, a temperature ranging from 20 to 70°C in the presence of an alkaline agent such as sodium hydroxide) sodium silicate or sodium carbonate (pH = 7.5 to 1l.5) preferably 8.0 to 11.5) and optionally a bleaching agent such as hydrogen peroxide in addition to the deinking composition of the present invention. If the pulp concentration is less than 496 or the temperature is less than 20 °C) the amount of undefibrated pulp increases since the frictional force between pulp fibers during defibering is low and the content of ink in the pulp increases. Thus) the resulting regenerated pulp cannot be used as starting material for paper-making. On the other hand) the pulp concentration exceeds 259o or the temperature is higher than 70 °C, high quality regenerated pulp cannot be obtained since the frictional force between pulp fibers is extremely high and the strength of the resulting regenerated pulp is reduced due to frictional heat. Further) if the pH value during the defibering is less than 7.5, the degree of swelling of the pulp fibers during the defibering is low and accordingly the content of undefibrated fibers 20~6~0g increases, the content of ink in the pulp increases and, therefore) high Quality regenerated pulp cannot be prepared. Thus, the resulting regenerated pulp cannot be used as starting material for paper-making.
If the pH value exceeds l1.5. the resulting pulp causes yellowing by alkali baking, thereby the reduction of brightness occurs, and the strength of the resulting reclaimed paper is accordingly lowered.
The aging step may be carried out employing the same compositions used in the defibering step. The aging step is preferably performed at a pulp concentration ranging from 10 to 30%.
a temprature ranging from 30 to 80°C for at least one hour. If the pulp concentration is less than 10% and the temperature is lower than 30 °C, a sufficient aging effect cannot be ensured and accordingly high Quality regenerated pulp cannot be obtained. If the temperature exceeds 80 °C, the strength of the resulting reclaimed paper is lowered due to the effect of heat. Moreover, any significant aging effect cannot be anticipated even if the pulp concentration is increased to more than 30%. If pH for the aging step is lower than 8, any desired aging effect is not ensured. On the other hand, if the pH
value exceeds 12) the resulting pulp causes Yellowing due to the alkali baking and hence the brightness of the resulting pulp is impaired. Further) the strength of the resulting reclaimed paper is likewise lowered.
The separated ink can effectively be removed from the pulp slurry through the flotation performed at a pulp concentration of 0.5 to 1.5% and a temperature of 20 to 45°C.
The deinking method of the present invention may further 207~30~
comprise various steps commonly used in the deinking method such as dilution and/or dewatering steps, a screening step and treatments with a disperser and/or kneader without any influence on the quality of the resulting regenerated pulp and the operability of the method.
In addition, the deinking composition of the present invention may likewise be added to an ink-separation step, for instance) to a kneader, a refiner and/or a disperser, in addition to the foregoing defibering and aging steps.
If the deinking composition of the present invention is used in the deinking step of the washing method, stable operation without accompanying any trouble due to foaming can be ensured and high quality regenerated pulp having a high brightness and a low content of remaining ink unlike the usual methods and those disclosed in known patents in which ethylene oxide/propylene oxide adducts of higher alcohols are used.
The deinking composition of the present invention can be used simultaneous with polyoxyalkylene alkyl ether sulfates. fatty acids or salts thereof and/or alkylene oxide adducts of rosin.
As has been explained above in detail, if the deinking composition of the present invention is used in the flotation method, excellent deinking effect can be anticipated and high quality regenerated pulp having a high brightness and a low content of remaining ink can be obtained. In particular, according to the present invention, an increase in the brightness of the resulting reclaimed paper of at least one rank higher than that observed for the conventional method can be achieved and the content of remaining ink is at least 25% lower than that observed when the compounds (A) and (B) are not simultaneously employed. Thus, the resulting reclaimed paper has a substantially improved brightness which can be recognized even with the naked eyes.
The present invention will hereinafter be explained in more detail with reference to the following Preparation Examples and non-limitative working Examples and the effects practically accomplished by the present invention will also be discussed in detail in comparison with Comparative Examples.
Preparation Example 1 After charging 108.2 g (0.4 mole) of stearyl alcohol and 1.01 g (0.20 with respect to the final product) of KOH as a catalyst to an autoclave of stainless steel, the reaction system was sufficiently purged with nitrogen gas. Then the reaction system was sufficiently dehydrated at 135 ~ 5 °C for 0.5 hour under reduced pressure and 2l1.2 g (4.8 moles) of ethylene oxide was gradually added to the reaction system while maintaining the temperature and pressure at 125 ~ 5 °C
and 1.0 to 3.0 kg/cmz, respectively. After completion of the addition, 2o the reaction system was matured at the reaction temperature for 2 hours and the unreacted ethylene oxide was removed under reduced pressure. Subsequently, 185.6 g (3.2 moles) of propylene oxide was gradually added while maintaining the temperature and pressure at l10 i--5 °C and 1.0 to 3.0 kg/cm2) respectively. After completion of the addition, the reaction system was matured at the reaction temperature for 2 hours and the unreacted propylene oxide was removed under 20'6308 reduced pressure. Then acetic acid was added to adjust the pH of the reaction system to 6 to 8 (Sample 1).
The same procedures used above were repeated except that the conditions listed in Table 1 were used to give Samples 2 and 3.
Preparation Example 2 After charging l08.2 g (0.4 mole) of stearyl alcohol and l.27 g (0.2% with respect to the final product) of KOH as a catalyst to an autoclave of stainless steel, the reaction system was sufficiently to purged with nitrogen gas. Then the reaction system was sufficiently dehydrated at 120°C for 2.0 hours under reduced pressure and 35.2 g (0.8 mole) of ethylene oxide was gradually added to the reaction system while maintaining the temperature and pressure at 175 ~ 5 °C and 1.0 to 3.0 kg/cmz, respectively. After completion of the addition, the reaction system was matured at the reaction temperature for 2 hours and the unreacted ethylene oxide was removed under reduced pressure. Subsequently, a mixture comprising 28l.6 g (6.4 moles) of ethylene oxide and 208 g (3.6 moles) of propylene oxide was gradually added while maintaining the temperature and pressure at 120~ 5 °C and 1.0 to 3.0 kg/cm2, respectively. After completion of the addition, the reaction system was matured at the reaction temperature for 2 hours and the unreacted ethylene oxide and propylene oxide were removed under reduced pressure. Then the reaction mixture was cooled, 0.18 g (0.20% with respect to the final product) of KOH as a catalyst was additionally supplemented, the reaction system was sufficiently purged with nitrogen gas. Thereafter the reaction system was 20'~630~
sufficiently dehydrated at 120 ~ 5 °C for 2 hours under reduced pressure and 92.8 g (1.6 mole) of propylene oxide was gradually .added to the reaction system while maintaining the temperature and pressure at 115 ~5 °C and 1.0 to 3.0 kg/cm2, respectively. After completion of the addition, the unreacted propylene oxide was removed under reduced pressure, followed by cooling and addition of acetic acid to adjust the pH of the reaction system to 6 to 8 (Sample 4).
The same procedures used above were repeated except that propylene oxide was added after randomly adding, in advance, ethylene oxide and propylene oxide under the conditions listed in Table 1 to give Sample 5.
Table l: RO ~(EO)- ((EO)(PO)) H (Component (B)) Sample Alkyl Group Total ((EO)(PO)) EO/PO By-product No. (ratio: wt96) E0; PO Conf ig. (96) 1 Cls 12; 8 block 1.50 1.25 2 C1$/Cz2=70:30 18; 9 block 2.00 2.l5 3 C1 6/C18=40/60 18; 16 random 1. 13 1. 15 4 Cls 18; 10 random, block *' 1.80 2.25 5 (16/C,$=30/70 16; 13 random, block *' 1.23 2.15 ~1: Ethylene oxide and propylene oxide are randomly added and then propylene oxide is further added.
Terminal added PO molar numbers are 4 for Sample 4 and 5 for Samp 1 a 5.
Preparation Example 3 20'6308 After charging l08.2 g (0.4 mole) of stearyl alcohol and 1.20 g (0.18°6 with respect to propylene oxide (1 mole) adduct of stearyl alcohol) of KOH as a catalyst to an autoclave, the reaction system was sufficiently purged with nitrogen gas: Then the reaction system was sufficiently dehydrated at 140 ~ 5 °C for one hour under reduced pressure and 23a2 g (0.4 moles) of propylene oxide was gradually added to the reaction system while maintaining the temperature and pressure at 115 ~5 °C and 1.0 to 3.0 kg/cm2, respectively. After completion of the addition) the reaction system was matured at the reaction temperature for 2 hours and the unreacted propylene oxide was removed under reduced pressure. Subsequently) the reaction system was cooled, 0.3 g (total amount of the catalyst with respect to the final product:
0.200 of KOH was additionally supplemented) the reaction system was sufficiently purged with nitrogen gas, a mixture comprising l76 g (4 moles) of ethylene oxide and 440.8 g (7.6 moles) of propylene oxide was gradually added while maintaining the temperature and pressure at 120~5 °C and 1.0 to 3.0 kg/cm2, respectively. After completion of the' addition, the reaction system was matured, the unreacted ethylene oxide and propylene oxide were removed under reduced pressure, followed by cooling and addition of acetic acid to adjust the pH of the reaction system to 6 to 8 (Sample 6).
The same procedures used above were repeated except that the conditions listed in Table 1 were adopted to give Samples 7, 10 and 11. When the added ethylene oxide and propylene oxide were in the block configuration, ethylene oxide was first added and then propylene oxide was added.
20'~6~08 Preparation Example 4 After charging 108.2 g (0.4 mole) of stearyl alcohol and 1.67 g (0.23 with respect to propylene oxide (5 moles)~ ethylene oxide (15 moles)~propylene oxide (10 moles) adduct of stearyl alcohol) of KOH
as a catalyst to an autoclave, the reaction system was sufficiently purged with nitrogen gas. Then the reaction system was sufficiently dehydrated at 125 ~ 5 °C for 1.5 hour under reduced pressure and 1l6 g (2 moles) of propylene oxide was gradually added to the reaction system while maintaining the temperature and pressure at 115 ~ 5 °C and 1.0 to 3.0 kg/cm2, respectively. After completion of the addition, the reaction system was matured at the reaction temperature for 2 hours and the unreacted propylene oxide was removed. Subsequently, a mixture comprising 270 g (6.1 moles) of ethylene oxide and 232 g (4 moles) of propylene oxide was gradually added while maintaining the temperature and pressure at l15~ 5 °C and 1. 0 to 3. 0 kg/cm2, respectively. After completion of the addition, the reaction system was' matured and the unreacted ethylene oxide and propylene oxide were removed. Then the reaction mixture was cooled) 0.44 g (total amount of the catalyst: 0.25 with respect to the final product) of KOH as a catalyst was additionally supplemented, the reaction system was sufficiently purged with nitrogen gas and sufficiently dehydrated at a high temperature under reduced pressure. Then 116 g (2 moles) of propylene oxide was gradually added to the reaction system while maintaining the temperature and pressure at 1l5 ~ 5 °C and 1.0 to 3.0 kg/cm2, respectively. After completion of the addition) the reaction ~U7fi348 system was matured, the unreacted propylene oxide was removed) followed by cooling and addition of acetic acid to adjust the pH of the reaction system to 6 to 8 (Sample 8).
The same procedures used above were repeated except that the conditions listed in Table 2 were used to give Sample 9.
Table 2: RO (PO) m ((EO)m (PO)n2) (Component(A)) - H
Samp le Alkyl Group nl, m) ((EO)(PO)) EO/PO -product By No. (ratio: wt~) n2 Config. (96) 6 C, g l) 10, random 0. 50 1. 53 7 C~ s/C, 8=30/703, 16, block 0. 67 2. 30 8 C, a 5, 15, random, block 0. 75 2. 53 15 *' 9 C, g /C 2 2 7, 18, d i t t o 0. 86 2. 85 =70 : 30 14 10 C, a 2) 18, b 1 ock 1. 50 2. 34 11 C, s /C 1 a 3, 18, b I ock 1. 20 2. 45 =20/80 12 ~1: Ethylene ropylene oxide randomly added oxide and p are and then propylene oxideis furtheradded.
Terminal added PO molar numbers are 5 Sample and 6 for 8 for Samp 1 a 9.
Comparative Preparation Example 1 The same procedures used in Preparation Example 1 except that ethylene oxide (18 moles) and propylene oxide (18 moles) were added to stearyl alcohol (1 mole) in a block configuration so that the ratio of the total molar number of the added ethylene oxide to the total molar number of the added propylene oxide was e9ua1 to 1 to give 2o~6vo~
Sample 12.
Table 3: RO ~ (EO)-[(EO)(PO)]H
Sample Alkyl Total C(EO)(P0)] EO/PO By-product No. Group E0; PO Config.
12 C, 8 18; 18 block 1. 0 2. 56 Preparation Example 5 The same procedures used in Preparation Example 3 except that 4 moles of propylene oxide were first added to one mole of stearylalcohol and then ethylene oxide C16 moles) and propylene oxide (12 moles) were added to the resulting adduct so that the ratio of the total molar number of the added ethylene oxide to the total molar number of the added propylene oxide was equal to 1 to give Sample 13.
Tab 1 a 4: RO (PO) ( (EO) ~, H (Component (A) " 1- (PO) nz 7 ) Samp I a Alky n 1) m, C (EO) (PO) EO/PO By-product No.' Group n2 Conf ig.
Tab 1 a 4: RO (PO) ( (EO) ~, H (Component (A) " 1- (PO) nz 7 ) Samp I a Alky n 1) m, C (EO) (PO) EO/PO By-product No.' Group n2 Conf ig.
13 C, 8 4, 16, 12 random 1. 0 2. 48 Example 1 Printed waste paper (weight ratio: offset-printed newspaper/magaaine = 7/3) as a starting material was cut into pieces of 3 X 3 cm, introduced into a pulper (available from Kumagai Riki Kogyo Co., Ltd.), warm water or water was added to control the .2076308 temperature and the pulp concentration, pH of the mixture was adjusted by the addition of sodium hydroxide and sodium silicatE and then 1.0~ (effective component) of hydrogen peroxide and 0.35 of various deinking compositions were added. Subsequently, the pulper was operated for 7 minutes to give a pulp slurry. The resulting pulp slurry was centrifuged using a filter cloth of 80 mesh to dewater and concentrate the slurry to a consistency of 15~ and water was added to adjust the pulp consistency to 5~. Then the pulper was operated for 3 minutes to further defiber. Warm water was added to adjust the pulp consistency to 1~ and the slurry was subjected to flotation for 7 minutes using a Denver type flotater (available from Kyokuto ShinkoCo.
Ltd.). The resulting pulp slurry was then concentrated to a pulp consistency of 10~ using a filter cloth of 80 mesh and diluted to 1~
with water. Then a pulp sheet was prepared from the pulp slurry using a TAPPI sheet-making machine.
The brightness of the resulting pulp sheet was determined by a color and color difference meter (Nippon Denshoku Kogyo Co., Ltd.) according to the method defined in JIS P-8123 and the content of the remaining ink was determined by an image-analyzer (Luzex: available from Nikore Co., Ltd.) in terms of the rate of area of the resulting reclaimed paper on which ink remains.
The results obtained are summarized in Table 5. In Table 5, operability during flotation (effect of foams) was evaluated on the basis of the following criteria. Further the effect accomplished by the simultaneous use of the deinking compositions) Samples 3 and 8, was examined for various amounts. The results are listed in Table 6.
A: Operability is good;
B: Foams are formed slightly in excess, but do not affect the operability.
C: Foams are formed rather insufficiently, but do not affect the operability.
D: Foams are excessly formed and the deinking operation is accordingly impracticable.
E: Foams are only slightly formed and accordingly the deinking operation is impracticable.
Table Test Deinking Composi- ConditionsBright-Residual Opera-Deinking No. t ion (wt96) PC Temp. pH ness Ink bi i ty 1 No.l/No.7:40/605 25 9.5 58.4 0.250 B
2 No.2/No.6:10/9015 40 10.9 57.7 0.275 C
3 No.3/No.8:20/805 40 9.8 58.1 0.258 A
4 No.4/No.9:70/3025 65 10.5 58.2 0.254 B
5' No.5/No.7:55/4515 30 11.5 58.4 0.251 A
6 No.l/No.8:33/6715 40 10.9 58.0 0.260 A
7 No.2/No.10:40/6015 40 11.2 57.4 0.280 B
8 No.3/No.7:70/3015 40 l1.3 59.2 0.2l4 A
9 No.3/No.11:70/3015 40 l1.1 58.6 0.233 A
10 No. 2 15 40 10.9 55.6 0:376 B
11 No. 6 15 40 l0.9 55.7 0.380 E
12 No. 12 15 40 l0.9 55.3 0.391 A
13 No. 13 15 40 l0.9 55.4 0.388 B
.276308 14 No. 7 15 40 10.8 55.9 0.363 A
Test Nos. 1~9: Examples; Test Nos. 1014: Comparative Examples.
Table 6 Deinking Compositi- Amount Added Bright - Residual Opera-at on (wt~) Defibering Step ness Ink bility No.3/No.8: 20/80 0.08 57.0 0.293 E
0.l0 57.5 0.276 C
0.35 58.l 0.258 A
1.00 58.7 0.232 A
2. 00 59. 1 0. 22l B
2.50 58.4 0.235 D
Defibering Conditions: PC = 5~; Temp. 40C; and = 9.8.
- pH
Example 2 Printed waste paper (weight ratio: offset-printed newspaper/magaaine = 7/3) as a starting material was cut into pieces of '3 X 3 cm, introduced into a pulper (available from Kumagai Riki Kogyo Co., Ltd.), warm water or water was added to control the temperature and the pulp consistency and pH of the mixture was adjusted by the addition of sodium hydroxide and sodium silicate. Then 0.15 of deinking compositions as listed in Table 7 were added and the pulper was operated for 7 minutes to give a pulp slurry. The resulting pulp slurry was centrifuged using a filter cloth of 80 mesh to dewater and adjust the pulp concentration of the slurry and pH of the slurry was adjusted by the addition of sodium hydroxide and sodium silicate. Thereafter, 1.796 of hydrogen peroxide and 0.1~ of deinking composition were added and the mixture was aged in a thermostatic oven.
After the aging, the pulp consistency of the slurry was again adjusted to 5~ with water and the pulper was operated for 3 minutes to perform defibering. Then warm water was added to control the pulp consistency to l~ and the slurry was subjected to flotation at 30°C
for 7 minutes using a Denver type flotater (available from Kyokuto Shinko Co.) Ltd.). The resulting pulp slurry was then concentrated to a pulp consistency of l096 using a filter cloth of 80 mesh and diluted to 196 with water. Then a pulp sheet was prepared from the slurry using a TAPPI sheet-making machine.
The brightness of the resulting pulp sheet was determined by a color measuring color-difference meter (Nippon Denshoku Kogyo Co.) Ltd.) according to the method defined in JIS P-8123 and the content of the remaining ink was determined by an image-analyzer (Luzex:
available from Nikore Co., Ltd.) in terms of the rate of area of the resulting paper on which ink remains.
The results obtained are summarized in Table 7. Further the effect accomplished by the simultaneous use of the deinking compositions, Samples 2 and 6 was examined for various amounts. The results are listed in Table 8.
Table 7 Test Deinking Compo- DefiberingConditions Aging Conditions No. s i t i on (wt96) PC Temp. pH PC Temp. pH
1 No.l/No.9:30/70 25 55 10.4 25 55 10.5 2~7~~Q~
2 No.2/No.6:20/80 20 65 10.1 30 60 9.6 3 No.3/No.7:60/40 5 35 9.8 20 55 10.8 4 No.4/No.8:45/55 15 55 10.3 20 55 10.9 No.5/No.7:90/10 5 35 10.8 25 60 11.2 5 6 No.4/No.7:29/71 15 55 10.3 20 55 l0.9 7 No. 3 5 35 9.8 20 55 l0.8 8 No. 8 15 55 10.3 20 55 10.9 9 No. 12 5 35 9.8 20 55 10.8 No. 13 15 55 l0.3 20 55 l0.9 Table 7 (continued) Test Bright- Residual Opera-No. ness Ink bility 1 59. 0 0. 231 A
2 58.8 0.235 A
3 59.3 0.223 A
4 58.9 0.233 A
5 59.3 0.222 A
6 59. 4 0. 221 A
7 56.5 0.341 B
8 56.8 0.339 A
9 56.3 0.346 A
10 56. 4 0. 341 A
Test Nos. 1~6: Examples; Test Nos. 710: Comparative Examples.
Table 8 Deinking Com- Amount Added Amount Added Bright-Residual Opera-position (wt9o) at Defiberingat Aging ness Ink bility No.2/No.6 0.15 not added 58.0 0.251 C
(20/80) 0.15 0.08 58.5 0.245 A
0.l5 0.10 58.8 0.235 A
0.l5 0.35 59.3 0.223 A
0.15 1.50 60.2 0.203 B
0.15 2.50 59.7 0.218 D
0.10 not added 57.4 0.275 C
0.l0 0.10 58.3 0.240 A
0.10 0.30 58.9 0.230 A
0. 10 1. 50 60. 0. 201 B
0.10 2.20 59.8 0.215 D
Ltd.). The resulting pulp slurry was then concentrated to a pulp consistency of 10~ using a filter cloth of 80 mesh and diluted to 1~
with water. Then a pulp sheet was prepared from the pulp slurry using a TAPPI sheet-making machine.
The brightness of the resulting pulp sheet was determined by a color and color difference meter (Nippon Denshoku Kogyo Co., Ltd.) according to the method defined in JIS P-8123 and the content of the remaining ink was determined by an image-analyzer (Luzex: available from Nikore Co., Ltd.) in terms of the rate of area of the resulting reclaimed paper on which ink remains.
The results obtained are summarized in Table 5. In Table 5, operability during flotation (effect of foams) was evaluated on the basis of the following criteria. Further the effect accomplished by the simultaneous use of the deinking compositions) Samples 3 and 8, was examined for various amounts. The results are listed in Table 6.
A: Operability is good;
B: Foams are formed slightly in excess, but do not affect the operability.
C: Foams are formed rather insufficiently, but do not affect the operability.
D: Foams are excessly formed and the deinking operation is accordingly impracticable.
E: Foams are only slightly formed and accordingly the deinking operation is impracticable.
Table Test Deinking Composi- ConditionsBright-Residual Opera-Deinking No. t ion (wt96) PC Temp. pH ness Ink bi i ty 1 No.l/No.7:40/605 25 9.5 58.4 0.250 B
2 No.2/No.6:10/9015 40 10.9 57.7 0.275 C
3 No.3/No.8:20/805 40 9.8 58.1 0.258 A
4 No.4/No.9:70/3025 65 10.5 58.2 0.254 B
5' No.5/No.7:55/4515 30 11.5 58.4 0.251 A
6 No.l/No.8:33/6715 40 10.9 58.0 0.260 A
7 No.2/No.10:40/6015 40 11.2 57.4 0.280 B
8 No.3/No.7:70/3015 40 l1.3 59.2 0.2l4 A
9 No.3/No.11:70/3015 40 l1.1 58.6 0.233 A
10 No. 2 15 40 10.9 55.6 0:376 B
11 No. 6 15 40 l0.9 55.7 0.380 E
12 No. 12 15 40 l0.9 55.3 0.391 A
13 No. 13 15 40 l0.9 55.4 0.388 B
.276308 14 No. 7 15 40 10.8 55.9 0.363 A
Test Nos. 1~9: Examples; Test Nos. 1014: Comparative Examples.
Table 6 Deinking Compositi- Amount Added Bright - Residual Opera-at on (wt~) Defibering Step ness Ink bility No.3/No.8: 20/80 0.08 57.0 0.293 E
0.l0 57.5 0.276 C
0.35 58.l 0.258 A
1.00 58.7 0.232 A
2. 00 59. 1 0. 22l B
2.50 58.4 0.235 D
Defibering Conditions: PC = 5~; Temp. 40C; and = 9.8.
- pH
Example 2 Printed waste paper (weight ratio: offset-printed newspaper/magaaine = 7/3) as a starting material was cut into pieces of '3 X 3 cm, introduced into a pulper (available from Kumagai Riki Kogyo Co., Ltd.), warm water or water was added to control the temperature and the pulp consistency and pH of the mixture was adjusted by the addition of sodium hydroxide and sodium silicate. Then 0.15 of deinking compositions as listed in Table 7 were added and the pulper was operated for 7 minutes to give a pulp slurry. The resulting pulp slurry was centrifuged using a filter cloth of 80 mesh to dewater and adjust the pulp concentration of the slurry and pH of the slurry was adjusted by the addition of sodium hydroxide and sodium silicate. Thereafter, 1.796 of hydrogen peroxide and 0.1~ of deinking composition were added and the mixture was aged in a thermostatic oven.
After the aging, the pulp consistency of the slurry was again adjusted to 5~ with water and the pulper was operated for 3 minutes to perform defibering. Then warm water was added to control the pulp consistency to l~ and the slurry was subjected to flotation at 30°C
for 7 minutes using a Denver type flotater (available from Kyokuto Shinko Co.) Ltd.). The resulting pulp slurry was then concentrated to a pulp consistency of l096 using a filter cloth of 80 mesh and diluted to 196 with water. Then a pulp sheet was prepared from the slurry using a TAPPI sheet-making machine.
The brightness of the resulting pulp sheet was determined by a color measuring color-difference meter (Nippon Denshoku Kogyo Co.) Ltd.) according to the method defined in JIS P-8123 and the content of the remaining ink was determined by an image-analyzer (Luzex:
available from Nikore Co., Ltd.) in terms of the rate of area of the resulting paper on which ink remains.
The results obtained are summarized in Table 7. Further the effect accomplished by the simultaneous use of the deinking compositions, Samples 2 and 6 was examined for various amounts. The results are listed in Table 8.
Table 7 Test Deinking Compo- DefiberingConditions Aging Conditions No. s i t i on (wt96) PC Temp. pH PC Temp. pH
1 No.l/No.9:30/70 25 55 10.4 25 55 10.5 2~7~~Q~
2 No.2/No.6:20/80 20 65 10.1 30 60 9.6 3 No.3/No.7:60/40 5 35 9.8 20 55 10.8 4 No.4/No.8:45/55 15 55 10.3 20 55 10.9 No.5/No.7:90/10 5 35 10.8 25 60 11.2 5 6 No.4/No.7:29/71 15 55 10.3 20 55 l0.9 7 No. 3 5 35 9.8 20 55 l0.8 8 No. 8 15 55 10.3 20 55 10.9 9 No. 12 5 35 9.8 20 55 10.8 No. 13 15 55 l0.3 20 55 l0.9 Table 7 (continued) Test Bright- Residual Opera-No. ness Ink bility 1 59. 0 0. 231 A
2 58.8 0.235 A
3 59.3 0.223 A
4 58.9 0.233 A
5 59.3 0.222 A
6 59. 4 0. 221 A
7 56.5 0.341 B
8 56.8 0.339 A
9 56.3 0.346 A
10 56. 4 0. 341 A
Test Nos. 1~6: Examples; Test Nos. 710: Comparative Examples.
Table 8 Deinking Com- Amount Added Amount Added Bright-Residual Opera-position (wt9o) at Defiberingat Aging ness Ink bility No.2/No.6 0.15 not added 58.0 0.251 C
(20/80) 0.15 0.08 58.5 0.245 A
0.l5 0.10 58.8 0.235 A
0.l5 0.35 59.3 0.223 A
0.15 1.50 60.2 0.203 B
0.15 2.50 59.7 0.218 D
0.10 not added 57.4 0.275 C
0.l0 0.10 58.3 0.240 A
0.10 0.30 58.9 0.230 A
0. 10 1. 50 60. 0. 201 B
0.10 2.20 59.8 0.215 D
Claims (2)
1. A flotation method for deinking printed waste paper, comprising the steps of defibering printed waste paper in the presence of a deinking composition to form a pulp slurry and then separating and removing separated ink particles from the pulp slurry through flotation, the deinking composition comprising:
(1) 99.7 to 97% by weight of a mixture comprising monoalkyl ethers of ethylene oxide/propylene oxide copolymers represented by the following general formulas (A-1) and (A-2):
R3O- (PO) n3- (EO) ma ~ (PO)n4-H (A-1) R4O- (PO) n5- [(EO) mb~ (PO)n6]-H (A-2) wherein the averaged molar numbers ma and mb of the added ethylene oxide moieties each range from 10 to 30, the averaged molar numbers (n3 + n4) and (n5 + n6) of the added propylene oxide moieties each range from 8 to 35, R3 and R4 independently represent an alkyl group having 12 to 22 carbon atoms, ma/(n3 + n4) ranges from 0.5 to 1.5, mb/(n5 + n6) ranges from 0.5 to 1.5, EO and PO represent ethylene oxide and propylene oxide units respectively, (EO)ma~(PO)n4 being in the form of a block configuration and [(EO)mb~(PO)n6] being in the form of a random configuration, the mixing weight ratio of the compound (A-1) to the compound (A-2) ranging from 10;90 to 90:10; and (2) 0.3 to 3.0% by weight of a polyalkylene oxide selected from the group consisting of polyethylene oxides, polypropylene oxides and ethylene oxide/propylene oxide copolymers.
(1) 99.7 to 97% by weight of a mixture comprising monoalkyl ethers of ethylene oxide/propylene oxide copolymers represented by the following general formulas (A-1) and (A-2):
R3O- (PO) n3- (EO) ma ~ (PO)n4-H (A-1) R4O- (PO) n5- [(EO) mb~ (PO)n6]-H (A-2) wherein the averaged molar numbers ma and mb of the added ethylene oxide moieties each range from 10 to 30, the averaged molar numbers (n3 + n4) and (n5 + n6) of the added propylene oxide moieties each range from 8 to 35, R3 and R4 independently represent an alkyl group having 12 to 22 carbon atoms, ma/(n3 + n4) ranges from 0.5 to 1.5, mb/(n5 + n6) ranges from 0.5 to 1.5, EO and PO represent ethylene oxide and propylene oxide units respectively, (EO)ma~(PO)n4 being in the form of a block configuration and [(EO)mb~(PO)n6] being in the form of a random configuration, the mixing weight ratio of the compound (A-1) to the compound (A-2) ranging from 10;90 to 90:10; and (2) 0.3 to 3.0% by weight of a polyalkylene oxide selected from the group consisting of polyethylene oxides, polypropylene oxides and ethylene oxide/propylene oxide copolymers.
2. A deinking composition for regeneration of waste paper by flotation which comprises:
(1) 99.7 to 97% by weight of a mixture comprising monoalkyl ethers of ethylene oxide/propylene oxide copolymers represented by the following general formulas (A-1) and (A-2):
R3O- (PO) n3- (EO) ma~ (PO) n4-H (A-1) R4O- (PO) n5- [(EO)mb~ (PO) n6]-H (A-2) wherein the averaged molar numbers ma and mb of the added ethylene oxide moieties each range from 10 to 30, the averaged molar numbers (n3 + n4) and (n5 + n6) of the added propylene oxide moieties each range from 8 to 35, R3 and R4 independently represent an alkyl group having 12 to 22 carbon atoms, ma/ (n3 + n4) ranges from 0.5 to 1.5, mb/ (n5 + n6) ranges from 0.5 to 1.5, EO and PO represent ethylene oxide and propylene oxide units respectively, (EO)ma~ (PO) n4 being in the form of a block configuration and [(EO)mb~(PO)n6] being in the form of a random configuration, the mixing weight ratio of the compound (A-1) to the compound (A-2) ranging from 10:90 to 90:10; and (2) 0.3 to 3.0% by weight of a polyalkylene oxide selected from the group consisting of polyethylene oxides, polypropylene oxides and ethylene oxide/propylene oxide copolymers.
(1) 99.7 to 97% by weight of a mixture comprising monoalkyl ethers of ethylene oxide/propylene oxide copolymers represented by the following general formulas (A-1) and (A-2):
R3O- (PO) n3- (EO) ma~ (PO) n4-H (A-1) R4O- (PO) n5- [(EO)mb~ (PO) n6]-H (A-2) wherein the averaged molar numbers ma and mb of the added ethylene oxide moieties each range from 10 to 30, the averaged molar numbers (n3 + n4) and (n5 + n6) of the added propylene oxide moieties each range from 8 to 35, R3 and R4 independently represent an alkyl group having 12 to 22 carbon atoms, ma/ (n3 + n4) ranges from 0.5 to 1.5, mb/ (n5 + n6) ranges from 0.5 to 1.5, EO and PO represent ethylene oxide and propylene oxide units respectively, (EO)ma~ (PO) n4 being in the form of a block configuration and [(EO)mb~(PO)n6] being in the form of a random configuration, the mixing weight ratio of the compound (A-1) to the compound (A-2) ranging from 10:90 to 90:10; and (2) 0.3 to 3.0% by weight of a polyalkylene oxide selected from the group consisting of polyethylene oxides, polypropylene oxides and ethylene oxide/propylene oxide copolymers.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22042791 | 1991-08-30 | ||
| JP220427/1991 | 1991-08-30 |
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| Publication Number | Publication Date |
|---|---|
| CA2076308A1 CA2076308A1 (en) | 1993-03-01 |
| CA2076308C true CA2076308C (en) | 1999-08-17 |
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ID=16750948
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2076308 Expired - Lifetime CA2076308C (en) | 1991-08-30 | 1992-08-18 | Deinking composition for flotation and deinking method |
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| Country | Link |
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| CA (1) | CA2076308C (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2627043B2 (en) * | 1993-02-26 | 1997-07-02 | ライオン株式会社 | Deinking agent and deinking method by flotation using the deinking agent |
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1992
- 1992-08-18 CA CA 2076308 patent/CA2076308C/en not_active Expired - Lifetime
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