CA2083460A1 - Water-in oil emulsions and their use in paper treatment - Google Patents
Water-in oil emulsions and their use in paper treatmentInfo
- Publication number
- CA2083460A1 CA2083460A1 CA002083460A CA2083460A CA2083460A1 CA 2083460 A1 CA2083460 A1 CA 2083460A1 CA 002083460 A CA002083460 A CA 002083460A CA 2083460 A CA2083460 A CA 2083460A CA 2083460 A1 CA2083460 A1 CA 2083460A1
- Authority
- CA
- Canada
- Prior art keywords
- microemulsion
- paper
- surfactant
- weight
- water
- 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.)
- Abandoned
Links
- 239000000839 emulsion Substances 0.000 title claims abstract description 6
- 239000004530 micro-emulsion Substances 0.000 claims abstract description 43
- 239000004094 surface-active agent Substances 0.000 claims abstract description 22
- 239000002904 solvent Substances 0.000 claims abstract description 17
- 239000007864 aqueous solution Substances 0.000 claims abstract description 12
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 11
- 229910052783 alkali metal Inorganic materials 0.000 claims abstract description 10
- 150000001340 alkali metals Chemical class 0.000 claims abstract description 10
- 229910052784 alkaline earth metal Inorganic materials 0.000 claims abstract description 9
- -1 alkaline earth metal salts Chemical class 0.000 claims abstract description 7
- 238000000034 method Methods 0.000 claims description 28
- IMNFDUFMRHMDMM-UHFFFAOYSA-N N-Heptane Chemical group CCCCCCC IMNFDUFMRHMDMM-UHFFFAOYSA-N 0.000 claims description 16
- 239000003795 chemical substances by application Substances 0.000 claims description 7
- 229910052751 metal Inorganic materials 0.000 claims description 5
- 239000002184 metal Substances 0.000 claims description 5
- 150000003839 salts Chemical class 0.000 claims description 5
- BVKZGUZCCUSVTD-UHFFFAOYSA-M Bicarbonate Chemical class OC([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-M 0.000 claims description 4
- 150000001342 alkaline earth metals Chemical class 0.000 claims description 4
- 239000011575 calcium Substances 0.000 claims description 4
- 239000002270 dispersing agent Substances 0.000 claims description 4
- 239000002563 ionic surfactant Substances 0.000 claims description 4
- 229910052791 calcium Inorganic materials 0.000 claims description 3
- 239000003960 organic solvent Substances 0.000 claims description 3
- 238000005406 washing Methods 0.000 claims description 3
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims description 2
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims description 2
- 238000009835 boiling Methods 0.000 claims description 2
- 125000004432 carbon atom Chemical group C* 0.000 claims description 2
- 150000004649 carbonic acid derivatives Chemical class 0.000 claims description 2
- 235000014113 dietary fatty acids Nutrition 0.000 claims description 2
- 239000000194 fatty acid Substances 0.000 claims description 2
- 229930195729 fatty acid Natural products 0.000 claims description 2
- 150000004665 fatty acids Chemical class 0.000 claims description 2
- 229910052749 magnesium Inorganic materials 0.000 claims description 2
- VTHJTEIRLNZDEV-UHFFFAOYSA-L magnesium dihydroxide Chemical class [OH-].[OH-].[Mg+2] VTHJTEIRLNZDEV-UHFFFAOYSA-L 0.000 claims description 2
- 235000012254 magnesium hydroxide Nutrition 0.000 claims description 2
- 150000002739 metals Chemical class 0.000 claims description 2
- 239000002736 nonionic surfactant Substances 0.000 claims description 2
- SNQQPOLDUKLAAF-UHFFFAOYSA-N nonylphenol Chemical class CCCCCCCCCC1=CC=CC=C1O SNQQPOLDUKLAAF-UHFFFAOYSA-N 0.000 claims description 2
- 150000001298 alcohols Chemical class 0.000 claims 2
- CDBYLPFSWZWCQE-UHFFFAOYSA-L sodium carbonate Substances [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 claims 2
- 235000011116 calcium hydroxide Nutrition 0.000 claims 1
- 238000007598 dipping method Methods 0.000 claims 1
- 238000001704 evaporation Methods 0.000 claims 1
- 230000008020 evaporation Effects 0.000 claims 1
- 150000004679 hydroxides Chemical class 0.000 claims 1
- 239000001095 magnesium carbonate Substances 0.000 claims 1
- 235000011160 magnesium carbonates Nutrition 0.000 claims 1
- 229920000847 nonoxynol Polymers 0.000 claims 1
- 235000011182 sodium carbonates Nutrition 0.000 claims 1
- 230000002209 hydrophobic effect Effects 0.000 abstract description 5
- 238000005470 impregnation Methods 0.000 abstract description 2
- 150000002500 ions Chemical class 0.000 description 10
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 6
- 239000001913 cellulose Substances 0.000 description 5
- 229920002678 cellulose Polymers 0.000 description 5
- 238000006731 degradation reaction Methods 0.000 description 5
- 239000002253 acid Substances 0.000 description 4
- 230000002378 acidificating effect Effects 0.000 description 4
- 150000007513 acids Chemical class 0.000 description 4
- 230000032683 aging Effects 0.000 description 4
- 230000015556 catabolic process Effects 0.000 description 4
- 229910052708 sodium Inorganic materials 0.000 description 4
- 239000011734 sodium Substances 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- QWDJLDTYWNBUKE-UHFFFAOYSA-L magnesium bicarbonate Chemical compound [Mg+2].OC([O-])=O.OC([O-])=O QWDJLDTYWNBUKE-UHFFFAOYSA-L 0.000 description 3
- 229910000022 magnesium bicarbonate Inorganic materials 0.000 description 3
- 235000014824 magnesium bicarbonate Nutrition 0.000 description 3
- 239000002370 magnesium bicarbonate Substances 0.000 description 3
- 238000010422 painting Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 2
- LRHPLDYGYMQRHN-UHFFFAOYSA-N N-Butanol Chemical compound CCCCO LRHPLDYGYMQRHN-UHFFFAOYSA-N 0.000 description 2
- AMQJEAYHLZJPGS-UHFFFAOYSA-N N-Pentanol Chemical compound CCCCCO AMQJEAYHLZJPGS-UHFFFAOYSA-N 0.000 description 2
- 125000000217 alkyl group Chemical group 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000000151 deposition Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- ZSIAUFGUXNUGDI-UHFFFAOYSA-N hexan-1-ol Chemical compound CCCCCCO ZSIAUFGUXNUGDI-UHFFFAOYSA-N 0.000 description 2
- 239000011777 magnesium Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 description 2
- 239000003981 vehicle Substances 0.000 description 2
- 238000004383 yellowing Methods 0.000 description 2
- DNIAPMSPPWPWGF-GSVOUGTGSA-N (R)-(-)-Propylene glycol Chemical compound C[C@@H](O)CO DNIAPMSPPWPWGF-GSVOUGTGSA-N 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- XDTMQSROBMDMFD-UHFFFAOYSA-N Cyclohexane Chemical compound C1CCCCC1 XDTMQSROBMDMFD-UHFFFAOYSA-N 0.000 description 1
- FBPFZTCFMRRESA-FSIIMWSLSA-N D-Glucitol Natural products OC[C@H](O)[C@H](O)[C@@H](O)[C@H](O)CO FBPFZTCFMRRESA-FSIIMWSLSA-N 0.000 description 1
- 101100536354 Drosophila melanogaster tant gene Proteins 0.000 description 1
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 1
- 229920002488 Hemicellulose Polymers 0.000 description 1
- NHTMVDHEPJAVLT-UHFFFAOYSA-N Isooctane Chemical compound CC(C)CC(C)(C)C NHTMVDHEPJAVLT-UHFFFAOYSA-N 0.000 description 1
- 241000283986 Lepus Species 0.000 description 1
- 241001435619 Lile Species 0.000 description 1
- 229920003171 Poly (ethylene oxide) Polymers 0.000 description 1
- DBMJMQXJHONAFJ-UHFFFAOYSA-M Sodium laurylsulphate Chemical compound [Na+].CCCCCCCCCCCCOS([O-])(=O)=O DBMJMQXJHONAFJ-UHFFFAOYSA-M 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 239000008135 aqueous vehicle Substances 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 229910052728 basic metal Inorganic materials 0.000 description 1
- 150000003818 basic metals Chemical class 0.000 description 1
- 238000004061 bleaching Methods 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 1
- 239000000920 calcium hydroxide Substances 0.000 description 1
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- HQWPLXHWEZZGKY-UHFFFAOYSA-N diethylzinc Chemical compound CC[Zn]CC HQWPLXHWEZZGKY-UHFFFAOYSA-N 0.000 description 1
- JVSWJIKNEAIKJW-UHFFFAOYSA-N dimethyl-hexane Natural products CCCCCC(C)C JVSWJIKNEAIKJW-UHFFFAOYSA-N 0.000 description 1
- 235000019329 dioctyl sodium sulphosuccinate Nutrition 0.000 description 1
- YHAIUSTWZPMYGG-UHFFFAOYSA-L disodium;2,2-dioctyl-3-sulfobutanedioate Chemical compound [Na+].[Na+].CCCCCCCCC(C([O-])=O)(C(C([O-])=O)S(O)(=O)=O)CCCCCCCC YHAIUSTWZPMYGG-UHFFFAOYSA-L 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 150000008282 halocarbons Chemical class 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 125000004435 hydrogen atom Chemical class [H]* 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000001473 noxious effect Effects 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 230000036647 reaction Effects 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 235000019333 sodium laurylsulphate Nutrition 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 239000000600 sorbitol Substances 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
- VZGDMQKNWNREIO-UHFFFAOYSA-N tetrachloromethane Chemical compound ClC(Cl)(Cl)Cl VZGDMQKNWNREIO-UHFFFAOYSA-N 0.000 description 1
- 239000004753 textile Substances 0.000 description 1
- 231100000167 toxic agent Toxicity 0.000 description 1
- 239000003440 toxic substance Substances 0.000 description 1
- 230000001988 toxicity Effects 0.000 description 1
- 231100000419 toxicity Toxicity 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H25/00—After-treatment of paper not provided for in groups D21H17/00 - D21H23/00
- D21H25/18—After-treatment of paper not provided for in groups D21H17/00 - D21H23/00 of old paper as in books, documents, e.g. restoring
Landscapes
- Paper (AREA)
- Colloid Chemistry (AREA)
Abstract
WATER-IN-OIL EMULSIONS AND THEIR USE IN PAPER TREATMENT
ABSTRACT
Water-in-oil (W/O) microemulsion containing an aqueous solution of water soluble alkali metal and alkaline earth metal salts, a hydrophobic solvent and a surfactant. Such a microemulsion is used in order to deacidify papers by impregnation.
ABSTRACT
Water-in-oil (W/O) microemulsion containing an aqueous solution of water soluble alkali metal and alkaline earth metal salts, a hydrophobic solvent and a surfactant. Such a microemulsion is used in order to deacidify papers by impregnation.
Description
~3 '1.~3~
lile pres~,lt inven~ion re,a~es ~o microemulsions of wa~er~ oi7 (~/'û~ ~ype and to tfleir use in the treatment of paper produc~s.
More ~ar~icularly, t~e present invention relates to W/0 microemulsions con~ainirly alkali meta7 and alhaline earth metal sa~ts, and to their ùse for deacid;fy;ng paper and pa~e~ produclx, such as books, drawings, paintings on paper an~ prin~inys.
Paper is knowrl to undergo degradation over time. The mos~ impor~arl~ factor among those factors which cause paper-ùegrada~ion is the acidity present in paper products.
Sucn acidity may have several origins, such as, for example:
-- ~ne acidic charac-ter or hydrolys;s of add;tives used in ~aper manufactor;ng process; and -- the conver-sion of air pollutànts adsorbed by paper (e.g.:
SU2) into strong acids (H2SG4);
-- lignine degr-adation;
-- oxidation of cellulose and hemicellulose dur;ng bleach-ing, or during the course of natural ageing.
In ar;dic paper, ageing causes discolouring (yellowing), brittleness, and, in general, loss of mecnanical properties of the paper. These effects are more serious if paper contains a large amount of lign;ne.
The acid-catalysed degradation process of paper ~ 3 ~
produc~s carl be s~opped by dear_idificatiorl.
The most widely used deacidification process is based or~ e pre~ipitation of an alhaline buffer on the cellulosic fivres of paper ~W.J. ~arrow, Restoration methods; Society oi` American Ar-c;nivists, Richmorld, Virginia, ~ct. 27, 1942).
The ~heets are soaked in a solution of calcium hydroxide, whi~rl neu~rali~es the acids presen~; residual calcium rhy~rvxide is subsequently conver~ed into carbonate by means or a b;carvo~la~e soiu~ion. Carbonate deposited on paper ~u~)plies an alhalirle r-eser-ve which, during a certain time periou, neutr-ali~es the acids coming from same paper and from 5Ur roundirlg environment.
unfortuna~ely, this process cannot be applied for a bulk tr-eatmen~ OT books, because these must be previously disassembled into individual sheets, and the individual snee~s must be treated and dried one by one.
~ urthermore, the use of such an aqueous solution causes, during the drying, the bonding of pages and the swelling of paper fibres.
The trend in the development of processes for paper deacidification was therefore one of depositing substances which may supply an alkaline buffer, while avoiding use of the aqueous vehicle.
~ a-A-2 18û 248 discloses an expensive process for paper pruducts preservation, in which a polymeric film is coated 3 _ r ~
,i,e me~r~ou ~isclosed in u.S. pa~ent 4 ~22 &43 uses a ~s~lena ion uorlsL i ~u~ed b y sa l~ts of basic metals and a su~u~ior) eonl~osed by an inert halogerlated hydrocarbon an~ a ~vrTde~dr)~. urlfor~urla~ely, ~he me~hod requires the use of IJ9~n~ O nydr oc;a r r)Or~S, Wil i~1 ar e nox ioUS and pollutan~.
T;le ~r~;es~ d isclc~seu in U.S. patent 3 676 055 pr u~eses a po~ r ea~merl~ for acidic books. According to this ~"~ "e ~o~ks are first dipped in a solution or ~s~er-siorl coln~osed by alkali metal and alkal;ne earth metal o~ides, arlri an or-garlic solvent. Subsequently, for the end pr-eser-va~ion treatment, a solution of alkyl oxides, or of a mixture of alkyl oxides under pression developed by a propeilarlt (Freon 12j -is used.
,his process suTfers from the following drawbacks:
-- two treatmenl sie~s;
-- inK migra~ion; and -- ~ne use of Freorl ~i.e., a halogenated hydrocarbon), which causes the process to be environmentally unfriendly.
in another_ process (G. ~elly, Non aqueous deaeidificatiorl of Books and Paper in Conservation of Library and Archive Materials and the Graphic Arts (G.
i-etherbridge, ed.), London, Butterworths, 1987, page 117) ~ne dried books are impregna~ed with diethylz;nc vapors at 3 ~
` c . L) i y ~ rly i ~ ; r)~u l r ~ es ~h~ ~c i d i t y ~nd i s ~ nver ted, wn~ r- du~or i)s ~;he nor~ noisture amount, into zinc 'J, io~, i,r)US l~avirl~ ~n a~h~line reserve.
The ~)ru(~es~ re~luir-e~ ~ very deep pre-drying because ~ne react ion ~el,ween w~er ~nd die~hilzinc is very fast; this ~r e-~ir y i rly c~ r-~ ion migr~t, c;i~u~;~ d~mages to paper produc~t.
rur t,herlnore~ in the presence of oxygen, diethylzinc is iv~ d ~ro~:~3s~ ~;e~y conditions mus~ be carefully uor~ (~r ~i i e~ .
~c i d ,o~er- ean b~ d~ac; i d i f i ed al so i n gas phase . Such a ~o~ isclc~s~ in U.S. p~tent 4 619 735, which use~
~mirles, such as mel~mine derivatives. Unfortunately, this process results in the likelihood that a low alkaline reserve will be found, andfurthermore causes paper yellowing and displays toxicity risks.
Therefore, the object of the present invention is to obviate or mitigate at least one of the disadvantages of the processes known from the prior art and to provide a relatively low-cost product and process for deacidifying paper and paper products in bulk, which process renders such paper products resistant to the effect of acids present in paper and/or deriving from surrounding environment.
The present Applicant has found now that the use of a microemulsion makes it possible to deposit an alkaline reserve and consequently protection of - 5 ~ R ~
paper to be achieved, with a relatively simple, low-cost and environmentally friendly process, because only surfactants are used, which Can be recovered at process end.
"Mi~;roemulsion" means a dispersed system of oil-in-wa~er or- wa~er-in-oil. "Oil" means a hydrofobic, water immiscible liquid.
These microemulsions are very stable, clear systems.
Ine stari1i~y of mi~;roemu7sions ix obta;ned by us;ng surfa~;~an~s (an~l, possibly, co-surfactants) which form a s~a~ er monolayer ar-ound dis~ersed water droplets.
The clearness results from dispersed droplets being of srnall. size (~û-1~ûO A~.
Tne use of a microemulsion of water-in-oil ~WiO) type as the vehicle Tor deac;dify;ng substances of paper d;splays two advantages:
-- Owing to the small amour-t of water contained in the emulsion, it does not cause the fibres to be swollen;
-- No pr-oblems ar ise during the drying step, because the i s pe r se n t p hase i s vo 7 a t i 1 e .
Therefore, in one of its aspects, the present invention provides a microemulsion of water-in-oil type containing the following components:
(a) an aqueous solution of alhal i metal and/or ellkal ine earth met~l :;al ts soluble in water in dispersed ph~lse, (b) a hydrophobic dispersant agent in continuous phase, 6 ~1 3 (~,) di~ ~ec~, One surTdc~arlt ayerl~:.
In another of its aspects, the present invention provides a microemulsion of water-in-oil, characterized in that its essential components are the following:
a~ 1-3û~ by we-igh~ of a 10 3 - 1G M aqueous solution of water-soluble alkali metal and alkaline earth me~al salts, b~ 5û-95% by weight of a hydrofobic organic solvent as the d i sper san~ agent, ( (.: ) 1 -4U~ y we i ght of at 1 east one non- i on i c or i on i c surfactant.
When an ionic: surfactant is used, the microemulsion possiL)ly compr ises from 1 to 20s6 by weight (based on surfactant) of an organic co-surfactant.
Particularly preferred accord;ng to the present inven~ion is a microemulsion containing 6-lû~ by weight of a lû-- - 1û-~ M aqueous solution of alkali metal and alkaline earth metal saits, 70-90% by weight of a hydrophobic solvent, 5-25% by weight of a surfactant.
I n the m i c roemu l s i on accord i ng to the present invention, water is used in order to act as the vehicle for the alkalating agent, therefore the amount of water used in the process is really kept at a minimum.
The salts of alkal i metals and alkal ine earth metals used in the emulsion according to the present invention can a ~ o~iues, ;)y~r-oxiues, oar~onaces an~ bicar-bonates of the me~als of ~roups I al)d II, as well as diborates ~e.g.:
i~a2B4G73; a~l o; them being watet-soluble.
Pre~erred cornpound are those containing Mg, Na, Ca;
parciculariy pr~ferred are non-toxicant compounds, such as maynes-ium ans sodium ox-ide~, carbonates and bicarbonates, and calciurn and magnesium hydroxides.
The hydrophobic organic solvent used in the microemulsion accordirlg to the present invention has a boiling poin~ comprised witnin the range of from O'C to 16ûC, pre;erarly comprised within the range of from ~O'C to 1 û ~, Non-limiting examples of solvents are cyclohexane, n-heptane, n-hexane, isooctane~ The preferred solvent is heptane.
The surfactar)t pr-esent in the microemulsion according 10 trle present invention is used in order to stabilize the small dispersed water droplets, reduc;ng the interfacial ~ension o; the sy~tem.
Examples of non-ionic surfactants are polyethoxylated long-chain aliphatic alcohols, in particular CH3~(CH2)n-CH20~(CH2CH20)m-CH2CH2OH
in which n = l-~û, and m = 1-1ûû; the fatty acids monoesters wi~h polyoxyethylene, in particular sorbitol monostearate (monopalmitate, and so forth); ethoxylated nonyl-phenols, ;n particular 1n3-(c~l2 )8-C6 H4~0~(CH2u;12G)n~H
irl w;lich n = 1-lûG.
Examp1es of ion ic surfactants are A:)T (sodium dioccy1su1fosurcinate) and SGS (sodium laurylsulfate).
When a nor1-ionic surfactant is used, the use of only one sur-fac:tant is enough Gn the contrary, when a ionic surfactant is used, it is sometimes necessary to employ a co-surfactant which decreases the density of surface charge generated by the ionic surfactant, reaching the interface and thus decreasing the interfacial tension. In that way, the co-surfactant makes it possible to achieve a dispersion of small water droplets. An example of Such a co-surfactant iS a linear-chain aliphatic alcohol with 3-16 carbon atoms, in particular n-butanol, n-pentanol, n-hexanol.
The microemu1sion according to the present invention obtained in tna~, way is suitab1e for the treatment of acidic paper in or der- to decrease the acidity thereof, and considerabiy s10w down its degradation over time and a1teration of i ~s mechanical proper-ties.
In another of its aspects, the present invention provides a process for the treatment of paper products, characterized in that the products are impregnated by di,uping into the above disclosed microemulsion, and the surfactant is subsequently removed by washing with solvent and the products are dried.
;r~ ~he process accordillg ro cr)e ~resent inven~iorl -che irrl~re91~a~iOrl OT ~aper wi~h rhe emulsion -is carried out at roorl) ~errlperature (2~ C). Trhe weiyh~ ratio of mirroemulsion to pa~er is comprised within the range of frorn 1:1 to 50:1.
The washirly of ~he impr-egnated paper is carried out wi~h a solvent, for example with an apolar solvent such as n-hep~ane, or an alcor)ol such as e~hanol.
Tne resul~iny ~reated paper- is dr-ierJ at a temperature co(llprised wicr~in cr-he range of fr-om O-C to ~G-C preferably comprised wi~hin the range of frorn 25C to 6~ C.
The evaluacion of the treatment is carried out by means OT rneasurement OT pH value and of alkaline reserve of paper.
~ ccording to the preferred process the WjO
rnicroemul~ion is prepared by starting from an aqueous soluiion con~a;ning salts of alkali metals or alkaline earth metals, a hydrophobic solvent and a surfactant. The acidic paper is impregnated by being dipped into this microemulsion a~ room terrlperature. The ratio of microemulsion to paper, by weight, is comprised within the range of from 2:1 to 20:1.
After the impregnation paper ;s washed with the solvent and then is oven dried at the temperature of ~O C.
The values obtained for the alkaline reserve and for the pH
value of paper demonstrate that the process according to the present invention provides a high de-acidification rate.
Therefore, the process according to the present - lo - ~3Li~)~
invention makes it possible to treat in bulk paper products, suCh as books (without that they have to be disassembled), drawings, paintings on paper, paintings, documents, and so forth; the fast deposition of alkalifier agents on paper fibres, or fast deacidification of paper; and the removal of soil from paper.
, he process acc;ording to the present, invention is sui~aL)ie Tor deacidifying cellulose-based paper, as well as ,~ui,o-~;on~aining paper.
Tbe process ~ccording to the present invention is simF~le and c:hea~, because it does not require special eclu i pmen t ~ and i s env i ronmental 1 y compati bl e, because the reac:tants used c:an be recycled wi thout releasing eco-toxic ~uL~ance~; into the env i ronment.
In erder to better understand the present invention, arld to practice i t, some ; 1 lustrat;ve, non-limiting examples are reported in the following.
The pH vaiue and the reflectance within the blue range [~ (3~) j have been determined according to the methods as described by Gavid N.-S. Hon, Historic Textile and Paper Materi~ls II; Chap~ter 2, page 24, American Chemical Society, 1 369 .
Exam~l e A water-in-oil (W~O) microemulsion was prepared by s i mpl y mi x i ng the fol 1 ow i ng components:
~ Q ~ 3 - ~ ~
I / 70 (.)T il~) I,dl~
1~ OT so~iurTI dioc T y 1 SU 1 T oSur_c i nate, ~nd a7r OT an ~4ueous solution OT s~ldium bicarbonate at 5% by weiyh~.
A sheec OT pure cellulose Whatlnarl paper with pH 5.7 was imllletseri in cnis microemulxioll. Tne paper was soahed for one hour at roorrl temper-a~ure (25 C~. The ratio of microemulsion t~ paper, uy weiyhc, was 5:1.
~ o treated paper was subsequently washed with ethanol, arld then was dr-ieo inside arl air-circulation oven at 50'C
for 3U rminutes The fo71Owirlg charar_~eristics OT paper were determined:
p~ = 10.0; depusiced alkaline reserve 0.1û~ (as expressed as percent CaC03 content, based on paper weight).
Exam~le 2 A water-in-oil ~W/0) microemulsion was prepared by simply rnixing tne following components:
80,u~ by weight OT heptane, 11,5~ by weight of sodium dioctylsulfosuccinate, and 8,5~ by weight of an aqueous solution of magnesium bicarbonate at 4% by weight.
A sheet of pure cellulose Whatman paper with pH 5.7 was immersed in this microemulsion. The paper was soahed for one hour at room temperature (25 C). The ratio of microemulsion to paper, by weight, was 5:1.
- 12 - ~ 3~
The so-treated paper wac subsequently washed with ethanol and then was dried inside an air-circulation oven at 50DC for 30 minutes.
The fo71Owiny crlar~c~eristics of paper were determined:
pH = 5 i; deposileu alkalirle reserve 0.15~ (as expressed as per cer~r, Ca~03 con~en~, based on paper weight).
Exam,ole 3 wa~er-irl-oil (WjOj microemulsion was prepared by ~ilnply mi~iny ~he followiny components:
~û ~ or heptarle, i 1, 5~ OT sod i um dioc:tylsu7fosuccinate, and OT an aqueous so7utiorl of magnesium bicarbonate at 4%
by wei ght h pu7p-corlrairlirlg paper sheet, visibly yellowed and naviny a pH value of 5.1, was dipped in this microemulsion.
The paper was soaked for one hour at room temperature ~5'C) Tne ratio of microemulsion to paper, by weight, was So ~r-ea~ed ~aper was subse4uently washed with ethanol arld then was dried inside an air-circulat;on oven at 50-C
Tor 30 minutes.
The following character;stics of paper were determined:
pH = a.6; reflectance within the blue range [Z (~)] 57.
The resulting paper was exposed to those condit;ons whir_h ar-e known to cause an accelerated paper ageing.
- 13 ~
InereTore~ ~a~er was ke~ stored inside an oven at 90 C with a rela~ive humidity of 5G~.
Under such conditions, during a one week storage, paper undergoes a degradation rate which corresponds to 147-420 years of natùral ageing.
The resùlts obtained are reported in follow;ng Table 1.
~'3 ~
. .
o ~, "- C~l ~ ~ t ~ ~ ~ = ~ C , =,~, o~ ~ , ,, ~
~, U~
g L _ "
O ~_ - 15 ~ .r ~ ~
Exan)Dle ~
A warer-in-oil (WjO) microemulsion was prepared by simply mixing the following comp~nents:
aG ~ of heptane, 11,5% of sodium dioc~ylsulfosucc;nate, and 8,~ of an aqueous solution of magnesium hydrogen carbona~e a~ 4X by weight A book (tied paper sheets having a pH value of 5.1) was dipped into this microemuls;on. The book was soaked for one hour at room temperature (25'C). The ratio of microemulsion to book, by weight, was 2:1.
The so treated book was subsequently washed with etharlol and then was air-dried, at room temperature.
The treated book had a pH value of 7.2.
ExamDle 5 A water-in-oil (W/0) microemulsion was prepared by simply mixing the following components:
~,5X of heptane, 22,5~ of LIALET 125j2(~) (a mixture of diethoxylated Ct20H
and C1 5 OH), lG,0~ of an aqueous solution of magnesium bicarbonate at 4X
by weight.
A sheet of pure cellulose Whatman paper with pH ~.7 was immersed in this microemulsion. The paper was soaked for one hour at room temperature ~25'C). The ratio of microemulsion r,'~
? r , L) y w ~ i ~ i l i,, ~ ,, ~ --, i , r~ p~p~?r was subsequentlY waerleri with ethan~l erl wa~, ~ir ie~i in~irie ~n air-r_iroulaibion oven ~ û'~, r .^,U Irl i rl~",~!j, ;oliowin~ or~ar-ar~,ler isi,iC,s or ,oaper were de~ermined:
,uii = ~ . r~; rie~ s i ~ed aiha7 ir~e r~ser ve ~1.11% ~ax exl~ressed as r ~ r ~ , u3 (~ o r ~ L~ ~ r~ r~ O r ~ ) r-~ r W ~3 i 9 rl t ) .
lile pres~,lt inven~ion re,a~es ~o microemulsions of wa~er~ oi7 (~/'û~ ~ype and to tfleir use in the treatment of paper produc~s.
More ~ar~icularly, t~e present invention relates to W/0 microemulsions con~ainirly alkali meta7 and alhaline earth metal sa~ts, and to their ùse for deacid;fy;ng paper and pa~e~ produclx, such as books, drawings, paintings on paper an~ prin~inys.
Paper is knowrl to undergo degradation over time. The mos~ impor~arl~ factor among those factors which cause paper-ùegrada~ion is the acidity present in paper products.
Sucn acidity may have several origins, such as, for example:
-- ~ne acidic charac-ter or hydrolys;s of add;tives used in ~aper manufactor;ng process; and -- the conver-sion of air pollutànts adsorbed by paper (e.g.:
SU2) into strong acids (H2SG4);
-- lignine degr-adation;
-- oxidation of cellulose and hemicellulose dur;ng bleach-ing, or during the course of natural ageing.
In ar;dic paper, ageing causes discolouring (yellowing), brittleness, and, in general, loss of mecnanical properties of the paper. These effects are more serious if paper contains a large amount of lign;ne.
The acid-catalysed degradation process of paper ~ 3 ~
produc~s carl be s~opped by dear_idificatiorl.
The most widely used deacidification process is based or~ e pre~ipitation of an alhaline buffer on the cellulosic fivres of paper ~W.J. ~arrow, Restoration methods; Society oi` American Ar-c;nivists, Richmorld, Virginia, ~ct. 27, 1942).
The ~heets are soaked in a solution of calcium hydroxide, whi~rl neu~rali~es the acids presen~; residual calcium rhy~rvxide is subsequently conver~ed into carbonate by means or a b;carvo~la~e soiu~ion. Carbonate deposited on paper ~u~)plies an alhalirle r-eser-ve which, during a certain time periou, neutr-ali~es the acids coming from same paper and from 5Ur roundirlg environment.
unfortuna~ely, this process cannot be applied for a bulk tr-eatmen~ OT books, because these must be previously disassembled into individual sheets, and the individual snee~s must be treated and dried one by one.
~ urthermore, the use of such an aqueous solution causes, during the drying, the bonding of pages and the swelling of paper fibres.
The trend in the development of processes for paper deacidification was therefore one of depositing substances which may supply an alkaline buffer, while avoiding use of the aqueous vehicle.
~ a-A-2 18û 248 discloses an expensive process for paper pruducts preservation, in which a polymeric film is coated 3 _ r ~
,i,e me~r~ou ~isclosed in u.S. pa~ent 4 ~22 &43 uses a ~s~lena ion uorlsL i ~u~ed b y sa l~ts of basic metals and a su~u~ior) eonl~osed by an inert halogerlated hydrocarbon an~ a ~vrTde~dr)~. urlfor~urla~ely, ~he me~hod requires the use of IJ9~n~ O nydr oc;a r r)Or~S, Wil i~1 ar e nox ioUS and pollutan~.
T;le ~r~;es~ d isclc~seu in U.S. patent 3 676 055 pr u~eses a po~ r ea~merl~ for acidic books. According to this ~"~ "e ~o~ks are first dipped in a solution or ~s~er-siorl coln~osed by alkali metal and alkal;ne earth metal o~ides, arlri an or-garlic solvent. Subsequently, for the end pr-eser-va~ion treatment, a solution of alkyl oxides, or of a mixture of alkyl oxides under pression developed by a propeilarlt (Freon 12j -is used.
,his process suTfers from the following drawbacks:
-- two treatmenl sie~s;
-- inK migra~ion; and -- ~ne use of Freorl ~i.e., a halogenated hydrocarbon), which causes the process to be environmentally unfriendly.
in another_ process (G. ~elly, Non aqueous deaeidificatiorl of Books and Paper in Conservation of Library and Archive Materials and the Graphic Arts (G.
i-etherbridge, ed.), London, Butterworths, 1987, page 117) ~ne dried books are impregna~ed with diethylz;nc vapors at 3 ~
` c . L) i y ~ rly i ~ ; r)~u l r ~ es ~h~ ~c i d i t y ~nd i s ~ nver ted, wn~ r- du~or i)s ~;he nor~ noisture amount, into zinc 'J, io~, i,r)US l~avirl~ ~n a~h~line reserve.
The ~)ru(~es~ re~luir-e~ ~ very deep pre-drying because ~ne react ion ~el,ween w~er ~nd die~hilzinc is very fast; this ~r e-~ir y i rly c~ r-~ ion migr~t, c;i~u~;~ d~mages to paper produc~t.
rur t,herlnore~ in the presence of oxygen, diethylzinc is iv~ d ~ro~:~3s~ ~;e~y conditions mus~ be carefully uor~ (~r ~i i e~ .
~c i d ,o~er- ean b~ d~ac; i d i f i ed al so i n gas phase . Such a ~o~ isclc~s~ in U.S. p~tent 4 619 735, which use~
~mirles, such as mel~mine derivatives. Unfortunately, this process results in the likelihood that a low alkaline reserve will be found, andfurthermore causes paper yellowing and displays toxicity risks.
Therefore, the object of the present invention is to obviate or mitigate at least one of the disadvantages of the processes known from the prior art and to provide a relatively low-cost product and process for deacidifying paper and paper products in bulk, which process renders such paper products resistant to the effect of acids present in paper and/or deriving from surrounding environment.
The present Applicant has found now that the use of a microemulsion makes it possible to deposit an alkaline reserve and consequently protection of - 5 ~ R ~
paper to be achieved, with a relatively simple, low-cost and environmentally friendly process, because only surfactants are used, which Can be recovered at process end.
"Mi~;roemulsion" means a dispersed system of oil-in-wa~er or- wa~er-in-oil. "Oil" means a hydrofobic, water immiscible liquid.
These microemulsions are very stable, clear systems.
Ine stari1i~y of mi~;roemu7sions ix obta;ned by us;ng surfa~;~an~s (an~l, possibly, co-surfactants) which form a s~a~ er monolayer ar-ound dis~ersed water droplets.
The clearness results from dispersed droplets being of srnall. size (~û-1~ûO A~.
Tne use of a microemulsion of water-in-oil ~WiO) type as the vehicle Tor deac;dify;ng substances of paper d;splays two advantages:
-- Owing to the small amour-t of water contained in the emulsion, it does not cause the fibres to be swollen;
-- No pr-oblems ar ise during the drying step, because the i s pe r se n t p hase i s vo 7 a t i 1 e .
Therefore, in one of its aspects, the present invention provides a microemulsion of water-in-oil type containing the following components:
(a) an aqueous solution of alhal i metal and/or ellkal ine earth met~l :;al ts soluble in water in dispersed ph~lse, (b) a hydrophobic dispersant agent in continuous phase, 6 ~1 3 (~,) di~ ~ec~, One surTdc~arlt ayerl~:.
In another of its aspects, the present invention provides a microemulsion of water-in-oil, characterized in that its essential components are the following:
a~ 1-3û~ by we-igh~ of a 10 3 - 1G M aqueous solution of water-soluble alkali metal and alkaline earth me~al salts, b~ 5û-95% by weight of a hydrofobic organic solvent as the d i sper san~ agent, ( (.: ) 1 -4U~ y we i ght of at 1 east one non- i on i c or i on i c surfactant.
When an ionic: surfactant is used, the microemulsion possiL)ly compr ises from 1 to 20s6 by weight (based on surfactant) of an organic co-surfactant.
Particularly preferred accord;ng to the present inven~ion is a microemulsion containing 6-lû~ by weight of a lû-- - 1û-~ M aqueous solution of alkali metal and alkaline earth metal saits, 70-90% by weight of a hydrophobic solvent, 5-25% by weight of a surfactant.
I n the m i c roemu l s i on accord i ng to the present invention, water is used in order to act as the vehicle for the alkalating agent, therefore the amount of water used in the process is really kept at a minimum.
The salts of alkal i metals and alkal ine earth metals used in the emulsion according to the present invention can a ~ o~iues, ;)y~r-oxiues, oar~onaces an~ bicar-bonates of the me~als of ~roups I al)d II, as well as diborates ~e.g.:
i~a2B4G73; a~l o; them being watet-soluble.
Pre~erred cornpound are those containing Mg, Na, Ca;
parciculariy pr~ferred are non-toxicant compounds, such as maynes-ium ans sodium ox-ide~, carbonates and bicarbonates, and calciurn and magnesium hydroxides.
The hydrophobic organic solvent used in the microemulsion accordirlg to the present invention has a boiling poin~ comprised witnin the range of from O'C to 16ûC, pre;erarly comprised within the range of from ~O'C to 1 û ~, Non-limiting examples of solvents are cyclohexane, n-heptane, n-hexane, isooctane~ The preferred solvent is heptane.
The surfactar)t pr-esent in the microemulsion according 10 trle present invention is used in order to stabilize the small dispersed water droplets, reduc;ng the interfacial ~ension o; the sy~tem.
Examples of non-ionic surfactants are polyethoxylated long-chain aliphatic alcohols, in particular CH3~(CH2)n-CH20~(CH2CH20)m-CH2CH2OH
in which n = l-~û, and m = 1-1ûû; the fatty acids monoesters wi~h polyoxyethylene, in particular sorbitol monostearate (monopalmitate, and so forth); ethoxylated nonyl-phenols, ;n particular 1n3-(c~l2 )8-C6 H4~0~(CH2u;12G)n~H
irl w;lich n = 1-lûG.
Examp1es of ion ic surfactants are A:)T (sodium dioccy1su1fosurcinate) and SGS (sodium laurylsulfate).
When a nor1-ionic surfactant is used, the use of only one sur-fac:tant is enough Gn the contrary, when a ionic surfactant is used, it is sometimes necessary to employ a co-surfactant which decreases the density of surface charge generated by the ionic surfactant, reaching the interface and thus decreasing the interfacial tension. In that way, the co-surfactant makes it possible to achieve a dispersion of small water droplets. An example of Such a co-surfactant iS a linear-chain aliphatic alcohol with 3-16 carbon atoms, in particular n-butanol, n-pentanol, n-hexanol.
The microemu1sion according to the present invention obtained in tna~, way is suitab1e for the treatment of acidic paper in or der- to decrease the acidity thereof, and considerabiy s10w down its degradation over time and a1teration of i ~s mechanical proper-ties.
In another of its aspects, the present invention provides a process for the treatment of paper products, characterized in that the products are impregnated by di,uping into the above disclosed microemulsion, and the surfactant is subsequently removed by washing with solvent and the products are dried.
;r~ ~he process accordillg ro cr)e ~resent inven~iorl -che irrl~re91~a~iOrl OT ~aper wi~h rhe emulsion -is carried out at roorl) ~errlperature (2~ C). Trhe weiyh~ ratio of mirroemulsion to pa~er is comprised within the range of frorn 1:1 to 50:1.
The washirly of ~he impr-egnated paper is carried out wi~h a solvent, for example with an apolar solvent such as n-hep~ane, or an alcor)ol such as e~hanol.
Tne resul~iny ~reated paper- is dr-ierJ at a temperature co(llprised wicr~in cr-he range of fr-om O-C to ~G-C preferably comprised wi~hin the range of frorn 25C to 6~ C.
The evaluacion of the treatment is carried out by means OT rneasurement OT pH value and of alkaline reserve of paper.
~ ccording to the preferred process the WjO
rnicroemul~ion is prepared by starting from an aqueous soluiion con~a;ning salts of alkali metals or alkaline earth metals, a hydrophobic solvent and a surfactant. The acidic paper is impregnated by being dipped into this microemulsion a~ room terrlperature. The ratio of microemulsion to paper, by weight, is comprised within the range of from 2:1 to 20:1.
After the impregnation paper ;s washed with the solvent and then is oven dried at the temperature of ~O C.
The values obtained for the alkaline reserve and for the pH
value of paper demonstrate that the process according to the present invention provides a high de-acidification rate.
Therefore, the process according to the present - lo - ~3Li~)~
invention makes it possible to treat in bulk paper products, suCh as books (without that they have to be disassembled), drawings, paintings on paper, paintings, documents, and so forth; the fast deposition of alkalifier agents on paper fibres, or fast deacidification of paper; and the removal of soil from paper.
, he process acc;ording to the present, invention is sui~aL)ie Tor deacidifying cellulose-based paper, as well as ,~ui,o-~;on~aining paper.
Tbe process ~ccording to the present invention is simF~le and c:hea~, because it does not require special eclu i pmen t ~ and i s env i ronmental 1 y compati bl e, because the reac:tants used c:an be recycled wi thout releasing eco-toxic ~uL~ance~; into the env i ronment.
In erder to better understand the present invention, arld to practice i t, some ; 1 lustrat;ve, non-limiting examples are reported in the following.
The pH vaiue and the reflectance within the blue range [~ (3~) j have been determined according to the methods as described by Gavid N.-S. Hon, Historic Textile and Paper Materi~ls II; Chap~ter 2, page 24, American Chemical Society, 1 369 .
Exam~l e A water-in-oil (W~O) microemulsion was prepared by s i mpl y mi x i ng the fol 1 ow i ng components:
~ Q ~ 3 - ~ ~
I / 70 (.)T il~) I,dl~
1~ OT so~iurTI dioc T y 1 SU 1 T oSur_c i nate, ~nd a7r OT an ~4ueous solution OT s~ldium bicarbonate at 5% by weiyh~.
A sheec OT pure cellulose Whatlnarl paper with pH 5.7 was imllletseri in cnis microemulxioll. Tne paper was soahed for one hour at roorrl temper-a~ure (25 C~. The ratio of microemulsion t~ paper, uy weiyhc, was 5:1.
~ o treated paper was subsequently washed with ethanol, arld then was dr-ieo inside arl air-circulation oven at 50'C
for 3U rminutes The fo71Owirlg charar_~eristics OT paper were determined:
p~ = 10.0; depusiced alkaline reserve 0.1û~ (as expressed as percent CaC03 content, based on paper weight).
Exam~le 2 A water-in-oil ~W/0) microemulsion was prepared by simply rnixing tne following components:
80,u~ by weight OT heptane, 11,5~ by weight of sodium dioctylsulfosuccinate, and 8,5~ by weight of an aqueous solution of magnesium bicarbonate at 4% by weight.
A sheet of pure cellulose Whatman paper with pH 5.7 was immersed in this microemulsion. The paper was soahed for one hour at room temperature (25 C). The ratio of microemulsion to paper, by weight, was 5:1.
- 12 - ~ 3~
The so-treated paper wac subsequently washed with ethanol and then was dried inside an air-circulation oven at 50DC for 30 minutes.
The fo71Owiny crlar~c~eristics of paper were determined:
pH = 5 i; deposileu alkalirle reserve 0.15~ (as expressed as per cer~r, Ca~03 con~en~, based on paper weight).
Exam,ole 3 wa~er-irl-oil (WjOj microemulsion was prepared by ~ilnply mi~iny ~he followiny components:
~û ~ or heptarle, i 1, 5~ OT sod i um dioc:tylsu7fosuccinate, and OT an aqueous so7utiorl of magnesium bicarbonate at 4%
by wei ght h pu7p-corlrairlirlg paper sheet, visibly yellowed and naviny a pH value of 5.1, was dipped in this microemulsion.
The paper was soaked for one hour at room temperature ~5'C) Tne ratio of microemulsion to paper, by weight, was So ~r-ea~ed ~aper was subse4uently washed with ethanol arld then was dried inside an air-circulat;on oven at 50-C
Tor 30 minutes.
The following character;stics of paper were determined:
pH = a.6; reflectance within the blue range [Z (~)] 57.
The resulting paper was exposed to those condit;ons whir_h ar-e known to cause an accelerated paper ageing.
- 13 ~
InereTore~ ~a~er was ke~ stored inside an oven at 90 C with a rela~ive humidity of 5G~.
Under such conditions, during a one week storage, paper undergoes a degradation rate which corresponds to 147-420 years of natùral ageing.
The resùlts obtained are reported in follow;ng Table 1.
~'3 ~
. .
o ~, "- C~l ~ ~ t ~ ~ ~ = ~ C , =,~, o~ ~ , ,, ~
~, U~
g L _ "
O ~_ - 15 ~ .r ~ ~
Exan)Dle ~
A warer-in-oil (WjO) microemulsion was prepared by simply mixing the following comp~nents:
aG ~ of heptane, 11,5% of sodium dioc~ylsulfosucc;nate, and 8,~ of an aqueous solution of magnesium hydrogen carbona~e a~ 4X by weight A book (tied paper sheets having a pH value of 5.1) was dipped into this microemuls;on. The book was soaked for one hour at room temperature (25'C). The ratio of microemulsion to book, by weight, was 2:1.
The so treated book was subsequently washed with etharlol and then was air-dried, at room temperature.
The treated book had a pH value of 7.2.
ExamDle 5 A water-in-oil (W/0) microemulsion was prepared by simply mixing the following components:
~,5X of heptane, 22,5~ of LIALET 125j2(~) (a mixture of diethoxylated Ct20H
and C1 5 OH), lG,0~ of an aqueous solution of magnesium bicarbonate at 4X
by weight.
A sheet of pure cellulose Whatman paper with pH ~.7 was immersed in this microemulsion. The paper was soaked for one hour at room temperature ~25'C). The ratio of microemulsion r,'~
? r , L) y w ~ i ~ i l i,, ~ ,, ~ --, i , r~ p~p~?r was subsequentlY waerleri with ethan~l erl wa~, ~ir ie~i in~irie ~n air-r_iroulaibion oven ~ û'~, r .^,U Irl i rl~",~!j, ;oliowin~ or~ar-ar~,ler isi,iC,s or ,oaper were de~ermined:
,uii = ~ . r~; rie~ s i ~ed aiha7 ir~e r~ser ve ~1.11% ~ax exl~ressed as r ~ r ~ , u3 (~ o r ~ L~ ~ r~ r~ O r ~ ) r-~ r W ~3 i 9 rl t ) .
Claims (15)
1. Microemulsion of water-in-oil type, in particular for the treatment of paper products, containing the following components:
(a) an aqueous solution of alkali metal and/or alkaline earth metal salts soluble in water in dispersed phase , (b) a hydrofobic dispersant agent in continuous phase , (c) at least one surfactant agent.
(a) an aqueous solution of alkali metal and/or alkaline earth metal salts soluble in water in dispersed phase , (b) a hydrofobic dispersant agent in continuous phase , (c) at least one surfactant agent.
2. Microemulsion according to claim 1, characterized in that it contains the following components:
(a) 1-30% by weight of a 10-3 - 10 M aqueous solution of water-soluble alkali metal and alkaline earth metal salts, (b) 50-95% by weight of a hydrofobic organic solvent as the dispersant agent, (c) 1-40% by weight of at least one non-ionic or ionic surfactant.
(a) 1-30% by weight of a 10-3 - 10 M aqueous solution of water-soluble alkali metal and alkaline earth metal salts, (b) 50-95% by weight of a hydrofobic organic solvent as the dispersant agent, (c) 1-40% by weight of at least one non-ionic or ionic surfactant.
3. Microemulsion according to any of the preceding claims, characterized in that it preferably contains the following components:
(a) 5-10% by weight of a 10 2 - 10 1 M aqueous solution of alkali metal and alkaline earth metal salts;
(b) 70-90% by weight of an hydrofobic solvent; and (c) 5-25% by weight of a surfactant.
(a) 5-10% by weight of a 10 2 - 10 1 M aqueous solution of alkali metal and alkaline earth metal salts;
(b) 70-90% by weight of an hydrofobic solvent; and (c) 5-25% by weight of a surfactant.
4. Microemulsion according to any of the preceding claims, characterized in that said salts of alkali metals and alkaline earth metals used in the emulsion according to the present invention can be oxides, hydroxides, carbonates of the metals of Groups I and II, as well as diborates, all of them being water-soluble.
5. Microemulsion according to claim 4, charaterized in that the preferred salts are magnesium and sodium carbonates and bicarbonates, and calcium and magnesium hydroxides.
6. Microemulsion according to any of the preceding claims, characterized in that the hydrofobic solvent has a boiling point comprised within the range of from 0°C to 160°C, preferably comprised within the range of from 50° C
to 100°C.
to 100°C.
7. Microemulsion according to claim 6, characterized in that the preferred solvent is heptane.
8. Microemulsion according to any of the preceding claims, characterized in that said surfactant is of non-ionic type and is selected from poly-ethoxylated long-chain alifatic alcohols, fatty acids monoesters with polyoyethilene, ethoxylated nonylphenols.
.
.
9. Microemulsion according to claim 1, characterized in that the surfactant is of ionic type and is selected from (C8-C20)-alkylsulfates.
10. Microemulsion according to claim 9, characterized in that it comprises a co-surfactant.
11. Microemulsion according to claim 10, characterized in that the co-surfactant is selected from linear chain alifatic alcohols with 3-16 carbon atoms.
12. Process for the treatment of papers and paper products, in particular for deacidifying them, characterized in that it comprises the following steps:
-- impregnating the paper product by dipping said paper product in a microemulsion of water-in-oil type containing an aqueous solution of water soluble alkali metals and/or alkaline earth metal salts, a hydrofobic dispersant agent and a surfactant agent, -- removing said surfactant agent from said paper product by washing with solvent, and -- removing said solvent from said paper product by evaporation.
-- impregnating the paper product by dipping said paper product in a microemulsion of water-in-oil type containing an aqueous solution of water soluble alkali metals and/or alkaline earth metal salts, a hydrofobic dispersant agent and a surfactant agent, -- removing said surfactant agent from said paper product by washing with solvent, and -- removing said solvent from said paper product by evaporation.
13. Process according to claim 12, characterized in that the ratio of microemulsion to paper, by weight, is comprised within the range of from 1:1 to 50:1.
14. Process according to claim 13, characterized in that the ratio of microemulsion to paper, by weight, is preferably comprised within the range of from 2:1 to 20:1.
15. Process according to any of claims from 12 to 14, characterized in that the washing solvent is an apolar solvent, preferably n-heptane.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ITMI91A003102 | 1991-11-20 | ||
| ITMI913102A IT1252006B (en) | 1991-11-20 | 1991-11-20 | MICROEMULSIONS OF WATER IN OIL AND THEIR USE IN PAPER TREATMENT |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2083460A1 true CA2083460A1 (en) | 1993-05-21 |
Family
ID=11361147
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002083460A Abandoned CA2083460A1 (en) | 1991-11-20 | 1992-11-20 | Water-in oil emulsions and their use in paper treatment |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0543372A1 (en) |
| JP (1) | JPH0615161A (en) |
| CA (1) | CA2083460A1 (en) |
| IT (1) | IT1252006B (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6080448A (en) * | 1998-04-03 | 2000-06-27 | Preservation Technologies Lp | Deacidification of cellulose based materials using hydrofluoroether carriers |
| AU2002246036A1 (en) * | 2002-01-15 | 2003-07-30 | Consorzio Interuniversitario Per Lo Sviluppo Dei Sistemi A Grande Interfase C.S.G.I. | Basic suspension, its preparation and process for paper deacidification |
| AU2003903296A0 (en) * | 2003-06-30 | 2003-07-10 | Raustech Pty Ltd | Chemical compositions of matter |
| ITUA20161894A1 (en) * | 2016-03-22 | 2017-09-22 | Univ Degli Studi Di Palermo | Composition for deacidification and paper reduction and related method for paper restoration |
| CN112962348B (en) * | 2021-02-05 | 2022-11-29 | 青岛大学 | Method for repairing damaged and aged paper file paper |
| CN115787350B (en) * | 2022-11-04 | 2024-05-31 | 国家图书馆 | Fluorine-containing deacidification liquid for paper |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3898356A (en) * | 1974-02-28 | 1975-08-05 | Us Army | Method of deacidifying paper |
| US4522843A (en) * | 1984-01-25 | 1985-06-11 | Kundrot Robert A | Deacidification of library materials |
-
1991
- 1991-11-20 IT ITMI913102A patent/IT1252006B/en active IP Right Grant
-
1992
- 1992-11-18 JP JP4309053A patent/JPH0615161A/en active Pending
- 1992-11-19 EP EP92119718A patent/EP0543372A1/en not_active Withdrawn
- 1992-11-20 CA CA002083460A patent/CA2083460A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| EP0543372A1 (en) | 1993-05-26 |
| ITMI913102A1 (en) | 1993-05-20 |
| IT1252006B (en) | 1995-05-27 |
| JPH0615161A (en) | 1994-01-25 |
| ITMI913102A0 (en) | 1991-11-20 |
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| Date | Code | Title | Description |
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| FZDE | Discontinued | ||
| FZDE | Discontinued |
Effective date: 19950520 |