Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J13/00—Colloid chemistry, e.g. the production of colloidal materials or their solutions, not otherwise provided for; Making microcapsules or microballoons
  • B01J13/02—Making microcapsules or microballoons
  • B01J13/06—Making microcapsules or microballoons by phase separation
  • B01J13/14—Polymerisation; cross-linking
• • 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
  • D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
  • C08J9/16—Making expandable particles
  • C08J9/18—Making expandable particles by impregnating polymer particles with the blowing agent
• • 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
  • D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
  • D21H21/50—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by form
  • D21H21/52—Additives of definite length or shape
  • D21H21/54—Additives of definite length or shape being spherical, e.g. microcapsules, beads
• • 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
  • D21H27/00—Special paper not otherwise provided for, e.g. made by multi-step processes
  • D21H27/30—Multi-ply

Definitions

• the present invention relates to a process for the production of paper or nonwoven and thermoplastic expandable microspheres useful therefore.
• Expandable thermoplastic microspheres comprising a thermoplastic polymer shell and a propellant entrapped therein are commercially available under the trademark EXPANCEL ® and are used as a foaming agent in many different applications.
• the propellant is normally a liquid having a boiling temperature not higher than the softening temperature of the thermoplastic polymer shell. Upon heating, the propellant evaporates to increase the internal pressure at the same time as the shell softens, resulting in significant expansion of the microspheres.
• the temperature at which the expansion starts is called T start> while the temperature at which maximum expansion is reached is called T ma ⁇ .
• Expandable microspheres are marketed in various forms, e.g. as dry free flowing particles, as an aqueous slurry or as a partially dewatered wet-cake. Expandable microspheres can be produced by polymerising ethylenically unsaturated monomers in the presence of a propellant. Detailed descriptions of various expandable microspheres and their production can be found in, for example, US Patents 3615972, 3945956, 5536756, 6235800, 6235394 and 6509384, and in EP 486080.
• the invention thus concerns use of thermally expandable microspheres comprising a thermoplastic polymer shell and from about 17 to about 40 wt%, preferably from about 18 to about 40 wt%, most preferably from about 19 to about 40 wt%, particularly most preferably from about 20 to about 35 wt% of a propellant entrapped in said polymer shell, and having a volume-average diameter from about 17 to about 35 ⁇ m, preferably from about 18 to about 35 ⁇ m, more preferably from about 19 to about 35 ⁇ m, most preferably from about 20 to about 30 ⁇ m, particularly most preferably from about 21 to about 30 ⁇ m, in the production of paper or non-woven for increasing the bulk thereof.
• expandable microspheres refers to expandable microspheres that have not previously been expanded, i.e. unexpanded expandable microspheres.
• volume-average diameter refers to values obtained by measuring according to ISO 13319:2000, "Determination of particle size distributions - Electrical sensing zone method". Detailed description of this measuring method can be obtained from, for example, Swedish Institute For Standards, Sweden.
• the invention further concerns a process for the production of paper or nonwoven from fibres comprising the steps of adding thermally expandable microspheres comprising a thermoplastic polymer shell and a propellant entrapped therein to a stock comprising fibres or to a web of fibres, forming paper or nonwoven from the stock or the web, and applying heat to raise the temperature of the microspheres sufficiently for them to expand and thereby increase the bulk of the paper or the nonwoven.
• the expandable microspheres have a volume-average diameter from about 17 to about 35 ⁇ m, preferably from about 18 to about 35 ⁇ m, more preferably from about 19 to about 35 ⁇ m, most preferably from about 20 to about 30 ⁇ m, particularly most preferably from about 21 to about 30 ⁇ m.
• the amount of propellant in the expandable microspheres is from about 17 to about 40 wt%, preferably from about 18 to about 40 wt%, most preferably from about 19 to about 40 wt%, particularly most preferably from about 20 to about 35 wt%.
• An embodiment of the invention concerns a process for the production of paper comprising the steps of adding expandable microspheres as described above to a stock containing cellulosic fibres, dewatering the stock on a wire to obtain paper, and drying the paper by applying heat and thereby also raising the temperature of the microspheres sufficiently for them to expand and increase the bulk of the paper.
• the expandable microspheres may be added separately or together with one or more other additive used in the papermaking process.
• the expandable microspheres can be added in any form, although it from a practical point of view is most preferred to add them in the form of an aqueous slurry, preferably having a solids content from about 5 to about 55 wt %, most preferably from about 40 to about 50 wt%.
• the slurry preferably also comprises a thickener compatible with paper making, such as anionic or cationic starch, optionally in combination with a salt such as sodium chloride.
• a thickener compatible with paper making such as anionic or cationic starch
• a salt such as sodium chloride.
• Starch may, for example, be present in the slurry in an amount from about 0.1 to about 5 wt%, preferably from about 0.3 to about 1.5 wt%.
• Sodium chloride, or another salt may, for example, be present in the slurry in an amount from about 0.1 to about 20 wt%, preferably from about 1 to about 15 wt%.
• the amount of expandable microspheres added to the stock is preferably from about 0.1 to about 20 wt%, most preferably from about 0.2 to about 10 wt% dry microspheres of the dry content in the stock. Any kind of paper machine known in the art can be used.
• paper is meant to include all types of cellulose-based products in sheet or web form, including, for example, board, cardboard and paperboard.
• the invention has been found particularly advantageous for the production of board, cardboard and paper board, particularly with a basis weight from about 50 to about 1000 g/m 2 , preferably from about 150 to about 800 g/m 2 .
• the paper may be produced as a single layer or a multi-layer paper. If the paper comprises three or more layers, the expandable microspheres are preferably not added to the portion of the stock forming any of the two outer layers.
• the stock preferably contains from about 50 to about 100 wt%, most preferably from about 70 to about 100 wt% of cellulosic fibres, based on dry material. Before dewatering, the stock besides expandable microspheres, may also contain one or more fillers, e.g.
• mineral fillers like kaolin, china clay, titanium dioxide, gypsum, talc, chalk, ground marble or precipitated calcium carbonate, and optionally other commonly used additives, such as retention aids, sizing agents, aluminium compounds, dyes, wet-strength resins, optical brightening agents, etc.
• aluminium compounds include alum, alumina- tes and polyaluminium compounds, e.g. polyaluminium chlorides and sulphates.
• retention aids include cationic polymers, anionic inorganic materials in combination with organic polymers, e.g. bentonite in combination with cationic polymers or silica-based sols in combination with cationic polymers or cationic and anionic polymers.
• sizing agents include cellulose reactive sizes such as alkyl ketene dimers and alkenyl succinic anhydride, and cellulose non-reactive sizes such as rosin, starch and other polymeric sizes like copolymers of styrene with vinyl monomers such as maleic anhydride, acrylic acid and its alkyl esters, acrylamide, etc.
• the paper, and thereby also the microspheres is preferably heated to a temperature from about 50 to about 150°C, most preferably from about 60 to about 110°C. This results in expansion of the microspheres and thereby also a bulk increase of the paper.
• the magnitude of this bulk increase depends on various factors, such as the origin of cellulosic fibres and other components in the stock, but is in most cases from about 5 to about 50 % per weight percentage of retained microspheres in the dried paper, compared to the same kind of paper produced without addition of expandable microspheres or any other expansion agent.
• Any conventional means of drying involving transferring heat to the paper can be applied, such as contact drying (e.g. by heated cylinders), forced convection drying (e.g. by hot air), infrared techniques, or combinations thereof.
• contact drying e.g. by heated cylinders
• forced convection drying e.g. by hot air
• infrared techniques or combinations thereof.
• the temperature of the contact surfaces e.g. the cylinders
• the paper may pass a series of several cylinders, e.g. up to 20 or more, of increasing temperature.
• the cellulosic fibres in the stock may, for example, come from pulp made from any kind of plants, preferably wood, such as hardwood and softwood.
• the cellulosic fibres may also partly or fully originate from recycled paper, in which case the invention has been found to give unexpectedly good results.
• Another embodiment of the invention concerns a process for the production of nonwoven comprising the steps of forming a web of fibres, adding to said web a binder and expandable microspheres as described above, and forming nonwoven and applying heat to raise the temperature of the microspheres sufficiently for them to expand and thereby increase the bulk nonwoven.
• the expandable microspheres and the binder may be added separately or as a mixture.
• the amount of expandable microspheres added is preferably from about 0.1 to about 30 wt% of dried product, most preferably from about 0.5 to about 15 wt% of dried product.
• the amount of binder added is preferably from about 10 to about 90 wt% of dried product, most preferably from about 20 to about 80 wt% of dried product.
• nonwoven as used herein is meant to include textiles made from fibres bonded together by means of a binder.
• the web of fibres can be formed in any conventional way, for example by mechanical or aerodynamical dry methods, hydrodynamical (wet) methods, or spunbonded processes.
• the binder preferably pre-mixed with expandable microspheres, can then be added to the web also in any conventional way, for example by any kind of impregnation method such as immersion of the web in a bath of binder or coating the web by kiss roll application or knife coating with a doctor blade or floating knife.
• the web comprising a binder and expandable microspheres can then be heated to a temperature sufficient for the microspheres to expand, preferably from about 70 to about 200°C, most preferably from about 120 to about 160°C.
• a temperature sufficient for the microspheres to expand preferably from about 70 to about 200°C, most preferably from about 120 to about 160°C.
• curing of the binder takes place at the same time.
• the heating can be effected by any suitable means, such as contact drying (e.g. by heated cylinders), forced convection drying (e.g. by hot air), infrared techniques, or combinations thereof.
• the fibres can be any kind of commercially available fibres, natural fibres, mineral fibres, as well as synthetic inorganic and organic fibres.
• useful fibres include polypropylene, polyethylene, polyester, viscose, and polyamide fibres, as well as fibres made from two or more of the above polymers.
• the binder can be any kind of natural or synthetic adhesive resin, such as resins of polyacrylates and co-polymers thereof, polymethacrylates and co-polymers thereof, rubber latexes such as styrene/butadiene copolymers, acrylonitrile/butadiene copolymers, poly(vinyl chloride) and copolymers, poly(vinyl ester) such as poly(vinyl acetate) and co- polymers, e.g. with ethylene, poly(vinyl alcohol), polyurethane, and aminoplast and phenoplast precondensates such as urea/ formaldehyde, urea/ melamine / formaldehyde or phenol/ formaldehyde.
• adhesive resin such as resins of polyacrylates and co-polymers thereof, polymethacrylates and co-polymers thereof, rubber latexes such as styrene/butadiene copolymers, acrylonitrile/buta
• thermoplastic polymer shell of the expandable microspheres is suitably made of a homo- or co-polymer obtained by polymerising ethylenically unsaturated monomers.
• Those monomers can, for example, be nitrile containing monomers such as acrylonitrile, methacrylonitrile, ⁇ -chloroacrylonitrile, -ethoxyacrylonitrile, fumaronitrile or crotonitrile; acrylic esters such as methyl acrylate or ethyl acrylate; methacrylic esters such as methyl methacrylate, isobornyl methacrylate or ethyl methacrylate; vinyl halides such as vinyl chloride; vinyl esters such as vinyl acetate other vinyl monomers such as vinyl pyridine; vinylidene halides such as vinylidene chloride; styrenes such as styrene, halogenated styrenes or ⁇ -methyl styrene; or dienes such as butadiene, isoprene and chloroprene.
• monomers such as acrylonitrile, methacrylonitrile, ⁇ -chloroacrylon
• the monomers comprise at least one acrylic ester or methacrylic ester monomer, most preferably methacrylic ester monomer such as methyl methacrylate.
• the amount thereof in the polymer shell is preferably from about 0.1 to about 80 wt%, most preferably from about 1 to about 25 wt% of the total amounts of monomers.
• the monomers comprise at least one vinylidene halide monomer, most preferably vinylidene chloride.
• the amount thereof in the polymer shell is preferably from about 1 to about 90 wt%, most preferably from about 20 to about 80 wt% of the total amounts of monomers.
• the monomers comprise both at least one acrylic ester or methacrylic ester monomer and at least one vinylidene halide monomer.
• the monomers comprise at least one nitrile containing monomer, most preferably at least one of acrylonitrile and methacrylonitrile, particularly most preferably at least acrylonitrile.
• the amount thereof in the polymer shell is preferably from about 1 to about 80 wt%, most preferably from about 20 wt% to about 70 wt% of the total amounts of monomers.
• the monomers comprise at least one acrylic ester monomer, at least one vinylidene halide and at least one nitrile containing monomer.
• the polymer shell may then, for example, be a co-polymer obtained from monomers comprising methyl methacrylate in a preferred amount from about 0.1 to about
• 80 wt% most preferably from about 1 to about 25 wt% of the total amounts of monomers, vinylidene chloride in a preferred amount from about 1 to about 90 wt%, most preferably from about 20 to about 80 wt% of the total amounts of monomers, and acrylonitrile in a preferred amount from about 1 to about 80 wt%, most preferably from about 20 to about
• the monomers for the polymer shell also comprise crosslinking multifunctional monomers, such as at least one of divinyl benzene, ethylene glycol di(meth)acrylate, di(ethylene glycol) di(meth)acrylate, triethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, 1 ,4-butanediol di(meth)acrylate, 1 ,6- hexanediol di(meth)acrylate, glycerol di(meth)acrylate, 1 ,3-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1 ,10-decanediol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, triallylformal tri(meth)acrylate, allyl me
• the amount thereof in the polymer shell is preferably from about 0.1 to about 10 wt%, most preferably from about 0.1 to about 1 wt%, particularly most preferably from about 0.2 to about 0.5 wt% of the total amounts of monomers.
• the propellant is normally a liquid having a boiling temperature not higher than the softening temperature of the thermoplastic polymer shell and may comprise hydrocarbons such as propane, n-pentane, isopentane, neopentane, butane, isobutane, hexane, isohexane, neohexane, heptane, isoheptane, octane or isooctane, or mixtures thereof.
• hydrocarbon types can also be used, such as petroleum ether, or chlorinated or fluorinated hydrocarbons, such as methyl chloride, methylene chloride, dichloroethane, dichloroethylene, trichloroethane, trichloroethylene, trichlorofluoromethane, perfluorinated hydrocarbons, etc.
• Preferred propellants comprise isobutane, alone or in a mixture with one or more other hydrocarbons.
• the boiling point at atmospheric pressure is preferably within the range from about -50 to about 100 °C, most preferably from about -20 to about 50 °C, particularly most preferably from about -20 to about 30 °C.
• the microspheres may comprise further substances added during the production thereof, normally in an amount from about 1 to about 20 wt%, preferably from about 2 to about 10 wt%.
• Such substances are solid suspending agents, such as one or more of silica, chalk, bentonite, starch, crosslinked polymers, methyl cellulose, gum agar, hydroxypropyl methylcellulose, carboxy methylcellulose, colloidal clays, and/or one or more salts, oxides or hydroxides of metals like Al, Ca, Mg, Ba, Fe, Zn, Ni and Mn, for example one or more of calcium phosphate, calcium carbonate, magnesium hydroxide, barium sulphate, calcium oxalate, and hydroxides of aluminium, iron, zinc, nickel or manganese.
• solid suspending agents such as one or more of silica, chalk, bentonite, starch, crosslinked polymers, methyl cellulose, gum agar, hydroxypropyl methylcellulose, carboxy methylcellulose, coll
• these solid suspending agents are normally mainly located to the outer surface of the polymer shell. However, even if a suspending agent has been added during the production of the microspheres, this may have been washed off at, a later stage and could thus be substantially absent from the final product.
• thermoplastic polymer shell made of a co-polymer obtained by polymerising ethylenically unsaturated monomers comprising at least one acrylic ester or methacrylic ester monomer and at least one vinylidene halide monomer, and from about 17 to about 40 wt%, preferably from about 18 to about 40 wt%, most preferably from about 19 to about 40 wt%, particularly most preferably from about 20 to about 35 wt% of a propellant entrapped in said polymer shell, wherein the expandable microspheres have a volume-average diameter from about 17 to about 35 ⁇ m, preferably from about 18 to about 35 ⁇ m, more preferably from about 19 to about 35 ⁇ m, most preferably from about 20 to about 30 ⁇ m, particularly most preferably from about 21 to about 30 ⁇ m.
• novel expandable microspheres can be prepared by polymerising the monomers in the presence of the propellant with the same methods as described in the earlier mentioned US Patents 3615972, 3945956, 5536756, 6235800, 6235394 and 6509384, and in EP 486080.
• the polymerisation is conducted as described below in a reaction vessel.
• one or more polymerisation initiator preferably in an amount from about 0.1 to about 5 parts
• aqueous phase preferably in an amount from about 100 to about 800 parts
• one or more preferably solid colloidal suspending agent preferably in an amount from about 1 to about 20 parts
• the temperature is suitably maintained from about 40 to about 90°C, preferably from about 50 to about 80°C, while the suitable pH depends on the suspending agent used.
• a high pH preferably from about 6 to about 12, most preferably from about 8 to about 10, is suitable if the suspending agent is selected from salts, oxides or hydroxides of metals like Al, Ca, Mg, Ba, Fe, Zn, Ni and
• Mn for example one or more of calcium phosphate, calcium carbonate, chalk, magnesium hydroxide, barium sulphate, calcium oxalate, and hydroxides of aluminium, iron, zinc, nickel or manganese.
• a low pH preferably from about 1 to about 6, most preferably from about 3 to about 5, is suitable if the suspending agent is selected from silica, bentonite, starch, methyl cellulose, gum agar, hydroxypropyl methylcellulose, carboxy methylcellulose, colloidal clays.
• Each one of the above agents have different optimal pH, depending on, for example, solubility data.
• promoters are organic materials and may, for example, be selected from one or more of water-soluble sulfonated polystyrenes, alginates, carboxymethylcellulose, tetramethyl ammonium hydroxide or chloride or water-soluble complex resinous amine condensation products such as the water-soluble condensation products of diethanolamine and adipic acid, the water-soluble condensation products of ethylene oxide, urea and formaldehyde, polyethylenimine, polyvinylalcohol, polyvinylpyrrolidone, amphoteric materials such as proteinaceous, materials like gelatin, glue, casein, albumin, glutin and the like, non-ionic materials like methoxycellulose, ionic materials normally classed as emulsifiers, such as soaps, alkyl sulfates and sul
• initiators are suitably selected from one or more of organic peroxides such as dialkyl peroxides, diacyl peroxides, peroxy esters, peroxy dicarbonates, or azo compounds.
• Suitable initiators include dicetyl peroxy dicarbonate, tert-butyl cyclohexyl peroxy dicarbonate, dioctanoyl peroxide, dibenzoyl peroxide, dilauroyl peroxide, didecanoyl peroxide, tert-butyl peracetate, tert-butyl perlaurate, tert-butyl perbenzoate, tert-butyl hydroperoxide, cumene hydroperoxide, cumene ethylperoxide, diisopropyl hydroxy dicarboxylate, azo-bis dimethyl valeronitrile, azo-bis isobutyronitrile, azo-bis (cyclo hexyl carbonit
• microspheres are normally obtained as an aqueous slurry or dispersion, which can be dewatered by any conventional means, such as bed filtering, filter pressing, leaf filtering, rotary filtering, belt filtering or centrifuging to obtain a so called wet cake that can be used as such.
• any conventional means such as bed filtering, filter pressing, leaf filtering, rotary filtering, belt filtering or centrifuging to obtain a so called wet cake that can be used as such.
• it is also possible to dry the microspheres by any conventional means, such as spray drying, shelf drying, tunnel drying, rotary drying, drum drying, pneumatic drying, turbo shelf drying, disc drying or fluidised bed-drying.
• EXAMPLE 1 A three layer paper board with a basis weight of about 180 g/m 2 was produced in a pilot paper machine with a machine speed of 7 m/min and having recirculated process water.
• the pulp was composed of 40 wt% hardwood and 60 wt% softwood pulp and was beaten to a Schopper-Riegler value of 25°SR and then dispersed to give a pulp slurry/stock.
• An aqueous slurry of expandable microspheres was before the mixing pump added to the stock used for the middle layer in an amount of about 1 wt% dry microspheres of the dry substance in the stock.
• As retention aid 0.1 wt% PolyminTM SK was used.
• EXAMPLE 2 A single layer paper board with a basis weight of about 200 g/m 2 was produced in a pilot paper machine with a machine speed of 4 m/min and not having recirculated process water.
• the pulp was composed of 50 wt% hardwood and 50 wt% softwood pulp and was beaten to a Schopper-Riegler value of 25°SR and then dispersed to give a pulp slurry/stock.
• An aqueous slurry of expandable microspheres was before the mixing pump added to the stock in an amount of about 1.75 wt% dry microspheres of the dry substance in the stock.
• As retention aid Compozil ® 0.1% BMA-OTM and 0.75% RaisamylTM 135, was used.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Dispersion Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Health & Medical Sciences (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Paper (AREA)

Priority Applications (1)

Applications Claiming Priority (4)

Publications (1)

Family

ID=33542576

Family Applications (1)

Country Status (8)

Cited By (1)

Families Citing this family (39)

Family Cites Families (28)

• 2004
  • 2004-06-01 CA CA002529139A patent/CA2529139A1/en not_active Abandoned
  • 2004-06-01 KR KR1020057024895A patent/KR100826419B1/ko not_active IP Right Cessation
  • 2004-06-01 CN CNA200480018016XA patent/CN1813105A/zh active Pending
  • 2004-06-01 EP EP04735699A patent/EP1636422A1/en not_active Withdrawn
  • 2004-06-01 US US10/505,775 patent/US20060102307A1/en not_active Abandoned
  • 2004-06-01 JP JP2006517018A patent/JP2007521410A/ja active Pending
  • 2004-06-01 WO PCT/SE2004/000835 patent/WO2004113613A1/en active Application Filing
• 2006
  • 2006-01-24 NO NO20060372A patent/NO20060372L/no not_active Application Discontinuation

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events