Classifications

• • 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
  • C08J3/00—Processes of treating or compounding macromolecular substances
  • C08J3/20—Compounding polymers with additives, e.g. colouring
  • C08J3/22—Compounding polymers with additives, e.g. colouring using masterbatch techniques
  • C08J3/226—Compounding polymers with additives, e.g. colouring using masterbatch techniques using a polymer as a carrier
• • 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
  • C08J2433/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Derivatives of such polymers

Definitions

• the present invention is generally directed to the incorporation of so-called “additives” into various synthetic materials.
• additives include anti-oxidants, antistatic agents, colorants, coupling agents, emulsifiers, flame retardants, foaming agents, fragrances, heat stabilizers, impact modifiers, lubricants, mold-release agents, organic peroxides, plasticizers, polyurethane foam catalysts, pourpoint modifiers, preservatives, silane coupling agents, slip and anti-blocking agents, smoke suppressants, ultraviolet (“UV”) stabilizers, viscosity modifiers, and so forth.
• UV ultraviolet
• the present invention is directed to novel concentrated polymeric compositions, any one of which is particularly useful for uniformly dispersing a particular additive throughout a number of different plastic materials.
• the present invention is also directed to a method for manufacturing the novel concentrated polymeric composition, mentioned above, as well as to a method for utilizing the concentrated polymeric composition to uniformly disperse a particular additive throughout a number of different plastic materials.
• many of the commercially-available color concentrates presently prepared specifically for uniform incorporation into the bulk of various plastic materials, comprise a pigment ingredient uniformly dispersed throughout a polymeric carrier ingredient.
• a color concentrate is itself typically uniformly dispersed throughout a plastic article - - such as a plastic part, or compound - - during the "processing" or manufacture of such a plastic article or compound and while such a yet-to-be-formed plastic article or compound is in a liquid or so-called "molten" rotate.
• plastic articles of this type might include plastic cooking and eating utensils and dinnerware, various plastics or elastomerics that are to be formed into toys for children, a wide assortment of outdoor recreational furniture, various plastics which are incorporated into the bodies of many of the motor vehicles currently seen on the road, and so forth.
• ABS acrylonitrile-butadiene-styrene
• FEP fluorinated ethyl enepropylene
• polystyrene PS
• PVC polyvinyl chloride
• SAN styrene-acrylonitrile
• TFE tetrafluoroethylene fluorocarbon polymer
• color concentrates One problem with virtually all of the several presently commercially-available color concentrates is that a specific polymer that is utilized to make such a concentrate is typically compatible with only a few plastic materials.
• a specific polymer that is utilized to make such a concentrate is typically compatible with only a few plastic materials.
• one such color concentrate which includes a rather specific polymeric carrier ingredient can generally be used to color only a very small number of different plastic materials; and, as a result, other color concentrates which include different polymeric carriers must therefore be selected for purposes of effectively coloring other plastic materials.
• the need for a separate color concentrate to color each such plastic material is due, we believe, to the incompatibility -- for one reason or another -- between the carrier polymer and the plastic material or substance into which the color concentrate is dispersed.
• Our novel polymeric concentrate comprises an additive ingredient and a polymeric carrier having a number-average molecular weight ("Mn") ranging between about 500 and about 20, 000.
• Mn number-average molecular weight
• Our polymeric carrier is a polymer which comprises about 10 parts-by-weight to about 100 parts-by-weight of a first monomeric ingredient which can be represented by the
• our polymeric carrier further comprises about 0 parts-by-weight to about 30 parts-by-weight of a second monomeric ingredient selected from the group consisting of an acid monomer, polymerizable half esters of dicarboxylic acids and/or salts thereof, and combinations thereof; and about 0 parts-by ⁇ weight to about 70 parts-by-weight of a third monomeric ingredient that is capable of being free radical addition copolymerized with the first monomeric ingredient.
• the polymeric concentrates of our invention comprise distinct additive ingredient particles that are uniformly dispersed throughout the bulk of the polymeric carrier briefly discussed above.
• the polymeric concentrate of our present invention is generally useful for incorporation into a wide assortment of different plastic materials or substances, for purposes of producing a wide variety of plastic articles or compounds having uniform physical, properties.
• polymeric concentrate of our invention is especially useful, when incorporated into plastic materials that exhibit polarity.
• plastic materials that exhibit polarity.
• polar plastic materials which are suitable in this regard include but are not limited to halogenated vinylic polymers, polyamides, polycarbonates, polyesters, polyethers, polyurethanes, polyvinyl esters, polyvinyl ethers, and the styrenics.
• Halogenated vinylic polymers that are illustrative include polyvinyl chloride (“PVC”), polyvinyl fluoride, polyvinylidine chloride, and so forth.
• polyamide Illustrative of one such polyamide is the family of polymers generically referred to as "nylon".
• nylon polymers
• nylon includes "NYLON 6", “NYLON 11”, “NYLON 12”, “NYLON 66”, and “NYLON 610", the structure of each of these being well-known to those skilled in the art. (See, for example, pages 433-437, of the "Textbook of Polymer Science", second edition, by Fred W. Billmeyer, Jr., published in 1971 by
• PC bisphenol A polycarbonate
• polyesters include polybutylene
• PET polyethylene terephthalate
• inventions include polybutylene oxide, polyoxymethylene, polypropylene oxide, and the epoxy resins.
• MDI methyl diphenyl isocyanate
• TDI toluene diisocyante
• PMMA polymethyl methacrylate
• PVA polyvinyl acetate
• polyvinyl ethers that would be suitable for our invention include polyvinyl isobutyl ether, polyvinyl methyl ether, and so forth.
• styrenics includes but is not limited to polymers made from styrene monomer, polyacrylonitrilebutadiene-styrene (“ABS”), polystyrene (“PS”), styreneacry l onitr i le (“SAN”) copolymer, and styrene-butadiene copolymer.
• styrene monomer includes but is not limited to v i nyl benzene monomer, a l pha-methylstyrene monomer, paramethylstyrene monomer, ortho-chlorostyrene monomer, Vertiary-butylstyrene monomer, al lyl benzene, and various mixtures of these.
• the polymeric carrier of our invention has a number-average molecular weight (“Mn”) that ranges between about 500 and about 20,000.
• composition and molecular weight of the polymeric carrier are both so chosen as to enable the "solid" polymeric
• Tg glass-transition temperature
• the polymeric carrier will have a Tg that may vary between about 20°C.
• Tg of the polymeric carrier will be highly dependent upon such factors as the type and/or amount of additive that is to be dispersed, the shipping-and-handling conditions to which the polymeric carrier is to be subjected, the various "transfer" conditions to which the polymeric carrier is subjected before incorporation into a particular plastic material or
• the polymeric concentrate of our present invention is, moreover, preferably dispersed throughout the polymeric or plastic material or substance, while the plastic material or substance is in a molten state, employing methods well-known to those skilled in the art.
• polymeric concentrate of our invention can thus readily be incorporated into the bulk of a wide assortment of different plastic materials, for producing a number of plastic articles including but not limited to various
• automotive articles such as fenders, dashboards, and seats; a wide assortment of outdoor and indoor furniture; various commercial and home appliances and flooring tiles; cooki ng and eating utensils and dinnerware; various building and construction materials; a wide assortment of recreational and sporting equipment; certain machine parts; computer keyboards and enclosures; a wide assortment of plastic containers of various shapes; various toys for children; and so forth.
• one aspect of our invention is directed to a novel polymeric concentrate comprising an additive ingredient dispersed throughout a polymeric carrier.
• the polymeric concentrate comprises about 10 weight percent to about B0 weight percent of the additive ingredient and about 20 weight percent to about 90 weight percent of the polymeric carrier.
• the polymeric concentrate comprises about 20 weight percent to about 80 weight percent of the additive ingredient and about 20 weight percent to about 80 weight percent of the polymeric carrier. More preferably, the polymeric concentrate comprises about 30 weight percent to about 60 weight percent of the additive ingredient and about 40 weight percent to about 70 weight percent of the polymeric carrier.
• Exemplary pigments which are suitable for purposes of our invention include a number of well-known inorganic and organic pigments such as carbon black, metal powder, titanium dioxide, iron, cadmium, chromium and zinc pigments, ferric hydrates, ultramarine blue, and other oxidic or sulfidic inorganic pigments as well as organic pigments such as azopigments, water-insoluble vat dyes, phtha locyani ne blue, bisoxazine, quinacridone and perylenetetracarboxylic acid dyestuffs. Additional well-known exemplary pigments that are suitable for purposes of our invention are disclosed, for example, at pages 37-55 of the textbook entitled “Coloring of Plastics", by T. G. Webber, published in 1979 by WileyInterscience, a division of John Wiley & Sons, Inc.; see also pages 253-290 of Volume II of the textbook entitled “Pigment Handbook", second edition, edited by Peter A. Lewis,
• the pigment ingredient and the polymeric color carrier can be combined, employing any one of a number of well-known methods.
• Typical commercial eguipment that may be
• about 0.0001 parts-by-weight to about 10 parts-by-weight, preferably about 0.001 parts-by-weight. to about 9 parts-by-weight, and more preferably about 0.01 parts-by-weight to about 8 parts-by-weight of the polymeric color concentrate can readily be dispersed throughout 100 parts-by-weight of the plastic material or substance, to produce a uniformly-colored plastic article or compound having various useful mechanical properties.
• plastic materials or substances are those which exhibit polarity.
• plastic substances are those which exhibit polarity.
• ABS acrylonitrile-butadiene-styrene
• bisphenol A bisphenol A
• PC polycarbonate
• PET polyethylene terephthalate
• PMMA polymethyl methacrylate
• PS polystyrene
• PVC polyvinyl chloride
• SAN styrene-acrylonitrile copolymer
• our polymeric carrier has a number-average molecular weight ("Mn") of between 500 and 20,000.
• Mn number-average molecular weight
• our polymeric carrier has an Mn of between 500 and 15,000. More preferably, our polymeric carrier has an Mn of between 600 and 12,000. Still more preferably, our polymeric carrier has an Mn of between 650 and 9,000. Most preferably, our polymeric carrier has an Mn of between 700 and 6,000.
• the polymeric, carrier is a polymer which comprises about 30 parts-by-weight to about 10 parts-by-weight of a "first monomeric ingredient".
• first monomeric ingredient may mean only one ingredient. or may mean several, including combinations, any one of which can be represented by the following
• R 2 is either an organic residue having a formula weight of less than about 300.
• R 2 is either an organic residue having a formula weight of less than about 300.
• R 2 is an alkyl group. Most preferably, R 2 is a methyl group.
• alkoxyalkyl groups for purposes of this aspect or feature of our invention include methoxyethyl,
• alkyl groups for purposes of our invention include amyl, butyl, cetyl, decyl, dodecyl, ethyl, 1-ethyl hexyl, 2-ethyl hexyl, he ⁇ yl, isoamyl, isobutyl, isopropyl, methyl, ootadeoenyl, octadecyl, octyl, propyl, sec-butyl, terf-amyl, terf-butyl, and 3,5,5-trimethylhexyl.
• Preferred alkyl groups include methyl, ethyl, butyl, and 2-ethyl hexyl.
• Exemplary alkyl aromatic groups for purposes of our invention include tolyl and xylyl.
• Exemplary aromatic groups for purposes of our present invention include phonyl, biphenyl, and naphthyl.
• inventions include cyclopentyl, cyclooctyl, and cyclohexyl.
• the first monomeric ingredient is selected from the group consisting of methyl methacrylate, ethyl acrylate, butyl acrylate, and combinations thereof.
• the polymeric carrier of our invention is a polymer which comprises about 0 parts-by-weight to about 30 parts-by-weight of a second monomeric ingredient selected from the group consisting of an acid monomer, polymerizable half esters of dicarboxylic acids and/or salts thereof, and combinations thereof.
• our polymeric carrier comprises at least about 0.0001 parts-by-weight up to about 29 parts-by-weight of the second monomeric ingredient. More preferably, the polymeric carrier of our invention comprises at least about
• the polymeric carrier of our invention comprises at least about 1.0 parts-by-weight up to about 15 parts-by-weight of the second monomeric ingredient.
• Exemplary acid monomers, as well as polymerizable half esters and/or salts thereof, for purposes of our invention include alpha, beta-ethylenically unsaturated monocarboxylic acid as well as monoesters of alpha, beta-ethylenically unsaturated dicarboxylic acids.
• suitable acid monomers for purposes of our invention include but are not limited to acrylic acid, othacrylic acid, fumaric acid-monoethyl ester, fumaric acid, itaconic acid, maleic acid, maleic anhydride, methacrylic acid, fumaric acid-monomethyl ester, and methyl hydrogen maleate.
• Ethacrylic acid is structurally represented as
• Fumaric acid-monoethyl ester is structurally represente as
• Fumaric acid-monomethyI ester is structurally
• Methyl hydrogen maleate is structurally represented as
• Preferred acid monomer is selected from the group consisting of acrylic acid, methacrylic acid, fumaric acid, maleic anhydride, and combinations thereof.
• the polymeric carrier of our invention is a polymer which also comprises about 0 parts-by-weight to about 70 parts-by-weight of a third monomeric ingredient that is capable of being free radical addition copolymerized with the first monomeric ingredient.
• the third monomeric ingredient is preferably selected from the group consisting of acrylonitrile, an olefin, a vinyl amine, a vinyl aromatic, a vinyl ester, a vinyl ether, a vinyl halide, and so forth, and combinations thereof.
• the polymeric carrier comprises at least about 0.0001 parts-by-weight up to about 65 parts-by-weight of the third monomeric ingredient; more preferably, the polymeric carrier comprises at least about 0.001 parts-by-weight up to about 60 parts-by-weight of the third monomeric ingredient; and, still more preferably, the polymeric carrie of our invention comprises at least about 0.01 parts-by-weight up to about 50 parts-by-weight of the third monomeric ingredient.
• the polymeric carrier comprises about 0.1 parts-by-weight. up to about 50 parts-by-weight of the third monomeric ingredient.
• the polymeric carrier comprises about 10 parts-by-weight up to about 30 parts-by-weight of the third monomeric ingredient.
• Exemplary olefins for purposes of our invention include but are not limited to 1-hexene, 2-hexene, 3-hexene,
• Exemplary vinyl amines for purposes of our invention include but are not limited to vinyl carbazole ("N-vinyl carbazole”), vinyl pyrrolidone ("N-vinyl-2-pyrrolidone”), and combinations thereof.
• Exemplary vinyl aromatics for purposes of our invention include but are not limited to vinylbenzene, alphamethylstyrene, para-methylstyrene, vinyl naphthalene, ally) benzene, para-chlorostyrene, and combinations thereof.
• Exemplary vinyl esters for purposes of our invention include but are not limited to vinyl acetate, vinyl benzoate, vinyl butyrate, vinyl propionate, and combinations thereof.
• Exemplary vinyl ethers for purposes of our invention include but are not limited to methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, isobutyl vinyl ether, and so forth, as well as a vinyl ether wherein the alkyl portion has up to about eighteen (18) carbon atoms, and combinations thereof.
• Exemplary vinyl halides for purposes of our invention include but are not limited to vinyl bromide, vinyl chloride, vinyl fluoride, vinyl idene chloride, vinylidene fluoride, and combinations thereof.
• the third monomeric ingredient is selected from the group consisting of vinyl benzene, alphamethylstyrene, para-methylstyrene, 1,3-butadiene, vinyl acetate, and combinations thereof.
• poly (styrene) standards utilized, presently commercially available from the Dow Chemical Company of Midland, Michigan, are more particularly characterized as having number-average molecular weight (“Mn") values of 2,250,000; 1,030,000;
• each such polymeric carrier thus investigated by us was deemed “miscible” in a particular plastic material when incorporation of about 10 parts-by-weight of the
• DMA mechanical analysis
• SEM scanning electron microscopy
• blend films were cast from a solution of about 1 part-by-weight of the polymeric carrier and about 9 parts-by-weight of the polar plastic material, wherein the polymeric carrier and the polar plastic material were then both dissolved in about 500 parts-by-weight of a common solvent such as tetrahydrofuran ("THF”) or methylene chloride, to produce a solution.
• Blend films were prepared by drying the solution in an aluminum dish in a hood for about 24 hours to produce a film; and, thereafter, further drying the resultant films in a vacuum oven at a temperature that ranged from about 50°C. to 70°C. for about 24 hours more.
• the Tg of the blend was deemed by us to be the single glass-transition temperature of blend which comprised the 10 parts-by-weight of the polymeric carrier in the 90 parts-by-weight of the polar plastic material; and the term "blend" is thus understood to mean 10 parts-by-weight of the polymeric carrier in 90 parts-by-weight of the polar plastic material.
• the 3-milligram film sample was maintained at such temperature for about ten (10) minutes to establish a socalled “melt-equilibrium" condition.
• SAN M M M ABS comprises particles of poly-1,3-butadiene dispersed throughout styrene-acrylonitrile (“SAN") copolymer.
• Polymeric carrier No. 1 was prepared in accordance with methods set forth in U.S. Pat. No. 4,546,160 to Brand et al., at a reaction temperature of about 182°C. and at a 12-minute residence time. More particularly, polymeric carrier No. 1 can be characterized as polymethyl methacrylate (“PMMA") homopolymer having a number-average molecular weight (“Mn”) of about 5200, and a glass-transition temperature (“Tg”) of 84 degrees Celsius (“°C”).
• PMMA polymethyl methacrylate
• Mn number-average molecular weight
• Tg glass-transition temperature
• Polymeric color carrier No. 2 was also prepared in accordance with methods set forth in U.S. Pat. No. 4,546,160, at a reaction temperature of about 182°C. and at a 12-minute residence time. More particularly, polymeric carrier No. 2 can be characterized as a copolymer of 20 weight percent ("wt.-%") styrene (“S”) and 80 wt.-% methyl methacrylate (“MMA”). Polymeric carrier No. 2 had an Mn of about 5000, and a Tg of 78°C.
• Polymeric carrier No. 3 was also prepared in accordance with methods set forth in U.S. Pat. No. 4,546,160, at a reaction temperature of about 182 °C. and at a 12-minute residence time. More particularly, polymeric carrier No. 3 can be characterized as a terpolymer of 20 wt.-% S, 70 wt.-% MMA and 10 wt.-% acrylic acid ("AA"). Polymeric carrier No. 3 had an Mn of about 3000 and a Tg of 78° C. The ABS utilized, commercially available under the "L
• Virginia had a dual Tg of 105°C. and 132°C.
• the PC utilized available under the "LEXAN” brand from General Electric Co. of Pittsfield, Massachusetts, had an Mn of 26,600; an Mw of 48,600; and a Tg of 1.49 °C.
• the PVC utilized available from Aldrich chemical Co., Inc., of Milwaukee, Wisconsin, had an Mn of 81,900; an Mw of
• the PET utilized, available from Hoechst-Celanese of
• T-907 had an intrinsic viscosity of 0.67, a Tg of 78°C., and a melting temperature of 230°C.
• the letter "M” is an indication that each of the above-described polymeric carriers was found to be miscible in the indicated polar plastic material, as determined via the DSC, DMA, and SEM analytical techniques mentioned above.
• PMMA polymethyl methacrylate copolymer
• such blends comprising about 10 partsby-weight of each one (1) of the three (3) PMMA polymeric carriers listed above, when combined with 90 parts-by-weight of each one (1) of the four (4) above-identified plastic materials, was found either to be miscible (“M”) or was found to be immiscible (“I”), as determined via DSC analysis, and such is indicated in Table II, above.
• the PMMA homopolymer identified above in Table II as having an Mn of 5200, is polymeric carrier No. 1, discussed above.
• Table III thus presents the as-is physical properties of a number of commercially-available polar plastic materials as well as the physical properties of each such plastic material after inclusion of 2 parts-by-weight of polymeric carrier No. 3 info 98 parts-by-weight of each such plastic material.
• Percent strain at break presented above, represents the percent elongation, at the length at which the sample coupon failed, relative to the initial length of the sample.
• Example 2 Polymeric Color Concentrates Polymeric color concentrates, in accordance with the principles of our invention, were prepared by combining first 70 parts-by-weight and thereafter 50 parts-by-weight of polymeric carrier No. 2 initially with 30 parts-by-weight and thereafter with 50 parts-by-weight of a well-known pigment ingredient, namely phthalocyanine blue, using a commercial roll mill at a temperature of about 120°C.
• a well-known pigment ingredient namely phthalocyanine blue
• Example 4; Yet Another Color Concentrate Polymeric carrier No. 4 was also prepared in accordance with methods set forth in U.S. Pat. No. 4,546,160, at a reaction temperature of 185oC. and at a 12-minufe residence time. More particularly, polymeric carrier No. 4 can be characterized as a tetrapolymer of 40 weight percent ("wt.%”) butyl acrylate (“BA”), 30 wt.-. methyl methacrylate (“MMA”) monomer, 20 wt.-% styrene (“S”) monomer, and 10 wt.-. acrylic acid (“AA”) monomer. Polymeric carrier No. 4 had a numberaverage molecular weight (“Mn”) of 3600 and a glasstransition temperature (“Tg”) of 17 degrees Celsius ( “ ° C “ ) .
• Mn numberaverage molecular weight
• Tg glasstransition temperature
• Example 5 Still Another Color Concentrate Polymeric carrier No. 5 was also prepared in accordance with methods set forth in U.S. Pat. No. 4,546,160, at a temperature of 182°C. and at a 12-minute residence time.
• polymeric carrier No. 5 can be any polymeric carrier No. 5. More particularly, polymeric carrier No. 5 can be any polymeric carrier No. 5.
• Polymeric carrier No. 5 had a number-average molecular weight (“Mn") of 6000 and a glass-transition temperature (“Tg") or 38 degrees Celsius (“°C”). Fifty (50) parts-by-weight of the pigment ingredient mentioned above in connection with Example 3 was combined with fifty (50) parts-by-weight of polymeric carrier No. 5, using the above-noted roll mill at a temperature of 80°C., for purposes of producing polymeric color concentrate No. 5A.
• Example 6 Yet Another Color Concentrate Polymeric carrier No. 6 was also prepared in accordance with methods set forth in U.S. Pat. No. 4,546,160, at a temperature of 188°C. and at a 12-minute residence time.
• polymeric carrier No. 6 can be any polymeric carrier No. 6
• MMA methyl methacrylate
• BA butyl acrylate
• S styrene
• AA acrylic acid
• Polymeric carrier No. 6 had a number-average molecular weight (“Mn”) of 5700 and a glass-transition temperature (“Tg”) of 63 degrees Celsius ( “°C.”).
• Color concentrate No. 3B for example, was utilized to show that a large number of different plastics from various types or classes of polar polymers can be colored using a single color concentrate. With respect to the remainder of the polymeric color concentrates presented in Table VI, generally a representative polar plastic material from each class was chosen to show the ability of a particular color concentrate.

Landscapes

• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Processes Of Treating Macromolecular Substances (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=24251796

Family Applications (1)

Country Status (6)

Cited By (1)

Citations (3)

• 1991
  • 1991-08-02 EP EP19910915593 patent/EP0542884A4/en not_active Withdrawn
  • 1991-08-02 WO PCT/US1991/005512 patent/WO1992002565A1/en not_active Application Discontinuation
  • 1991-08-02 JP JP51484291A patent/JPH06500143A/ja active Pending
  • 1991-08-02 CA CA002088481A patent/CA2088481A1/en not_active Abandoned
  • 1991-08-05 PT PT9857391A patent/PT98573A/pt not_active Application Discontinuation
• 1993
  • 1993-02-05 FI FI930510A patent/FI930510A/fi not_active Application Discontinuation

Patent Citations (3)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events