CA2057667A1 - Laminates - Google Patents
LaminatesInfo
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- CA2057667A1 CA2057667A1 CA 2057667 CA2057667A CA2057667A1 CA 2057667 A1 CA2057667 A1 CA 2057667A1 CA 2057667 CA2057667 CA 2057667 CA 2057667 A CA2057667 A CA 2057667A CA 2057667 A1 CA2057667 A1 CA 2057667A1
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- laminate according
- water soluble
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Abstract
Laminates ABSTRACT OF THE DISCLOSURE
A laminate comprising a layer of a water soluble polymer which provides mechanical strength and a protective layer of a relatively water insoluble degradable polymer has potential uses in disposable products such as laundry hampers and disposable diapers.
A laminate comprising a layer of a water soluble polymer which provides mechanical strength and a protective layer of a relatively water insoluble degradable polymer has potential uses in disposable products such as laundry hampers and disposable diapers.
Description
OF T~ INVENllON
The present invention relates to laminates of a water soluble polymer and a relatively water insoluble polymer. More particularly the present invention relates to laminates of a water soluUe polymer and a degradable relatively water insoluble polymer.
BACKGROUND OF T~ INVENTION
There are a number of uses of laminates or foils comprising a water soluble polymer and a relatively water insoluble polymer. One such use is in laundry hampers for hospita1s. Such hampers may be made of a relatively strong water soluble polymer. For the laundry hampers the outer layer is relative thick and provides most of the mechanical strength of the hamper. The 20 outer layer is also a water soluble polymer. When the hamper is placed in a washing machine the outer layer dissolves. The inner layer of the hamper is a relatively thin layer of insoluble polymer to protect the water soluble polymer from any dampness in the laundry. The full hamper is placed in a washing machine and the outer layer dissolves. The thin ifiner layer breaks under the mechanical action in the washing machine. The polymas are then discharged 30 with the water ~rom the washing machine. The hamper technology would also have potential use in the disposable diaper applications.
This technology might also be applicable in food packaging applications such as for foods which are moistened or cooked in water.
There are a series of patents in the name of Roland K. Belz which disclose similar laminates. In these patents the soluble layer comprises an acrylate polymer which is soluble only in alblline or acidic mediums.
Representative of such patents are United States Patent 4,261,066 issued April 14, 1981; United States Patent 4,469,728 issued September 4, 1984; and United States Patent 4,671,982 issued June 9, 1987. The Belz patents appear to be mainly concerned with the use of foils in sanitary applications such as covers for toilet seats.
Polyvinyl alcohol having a degrees of hydrolysis of greater than 80 weight % is soluble in either hot or cold water. Preferably the polyvinyl alcohol has a degree of hydrolysis of from 80 to 95 weight % so that it is cold water soluble. The properties of polyvinyl alcohol are discussed in Volume 23, page 849 of the Kirk Othmer Encyclopedia of Chemistry and Technology. One other advantage that polymers based on polyvinyl alcohol have is that they are biodegradable.
The polylactides, polyhydroxy butyrate and copolymers of beta hydroxy butyric acid, and beta hydroxy valeric acid are insoluble biodegradable polymers. To the best of applicant's knowledge these types of polymers have not been used in the above applications.
The present patent application seeks to provide additional water insoluble biodegradable polymer structures useful in the above applications.
20~7~67 SI~MARY OF T~ INVEN'IION
Accordingly, the present invention provides a laminate comprising one or more layers of one or more water soluble polymers and one or more layers of a relatively water insoluble polymer comprising residues of one or more monomers of the Formula:
-OCRIR2-(CR3R4)D-CO-wherein n is 0 or an integer from 1 to 5 and R" R2, R3, and R4 are independently selected the group consisting of a hydrogen atom and Cl 4 alkyl radicals.
VET~ILXD DESCRII'l'ION
The water soluble polymers useful in accordance with the present 2 o . invention may be selected frosn the group consisting of polyvinyl acetate having a molecular weight of not less than 30,000, preferably greater than 50,000 and a degree of saponification of not less than about 80%; polymers comprising:
(i) from 20 to l00 weight % of one or more C3 6 ethylenically unsaturated mono- or di- carboxylic acids;
(ii) 0 to 50 weight % of anhydrides of C46 dicarboxylic acids; and 30 (iii) from 0 to 80 weight % of one or more copolymerizable monomers;
provided that polymers containing monomers other than carboxylic acids or anhydrides thereof are sufficiently neutralized with an alkali or alkaline earthmetal or ammonia, ammonium hydroxide or a C~4 a1kyl primary amine to yield a water soluble polymer; soluble cellulose derivatives; polymers of C8 12 vinyl 2~7~67 aromatic monomers which polymers have been sulphonated; co and homopolymers of amides of C~6 ethylenically unsaturated carboxylic acids which amides are unsubstituted or substituted at the nitrogen atom by up to two radicals selected from the group consisting of Cl4 a1kyl radicals; polyvinyl pyrrolidine; polyvinyl pyrrolidone; and polyglutamic acid.
o Suitable water soluble polymers include vinyl acetate polymers having a molecular weight greater than about 30,000, more preferably greater than about 50,000. Preferably the polymers will have been saponified to not less than about80% most preferably to from about 87 to 90 weight % so that they are soluble in both hot and cold water. At a degree of saponification from 97 to 99 % the polyvinyl aclohol wi11 be soluble in hot water.
The water soluble polymer may be a co or homopolymer of one or more C~6 ethylenically unsaturated carboxylic acids and optionally anhydrides of C46 ethylenically unsaturated dicarboxylic acids. Preferred acids are acrylic and methacrylic acid. A preferred anhydride is mateic anhydride.
The water soluble polymer may be a copolymer comprising:
(i) from 20 to 100, preferably from 50 to 100, weight % of one or more of the above mono- or di- carboxylic acids;
Qi) from 0 to 50, preferably 0 to 20 weight % of anhydrides of C46 dicarboxylic acids; and (ii) from 0 to 80, preferably from 0 to 50, weight % of one or more copolymerizable monomers;
2~7~g7 provided that polymers containing monomers other than carboxylic acids or anhydrides thereof are sufficiently neutra1ized with an allcali or a1kaline earth metal or ammonia, ammonium hydroxide or a C,4 aL~cyl primary amine to yield a water soluble polymer.
Suitable copolymerizable monomers include C~l2 vinyl aromatic monomers which are unsubstituted or substituted by a Cl~ a1kyl radical such as styrene, ~-methyl styrene, p-methyl styrene, and t-butyl styrene. The comonomer may be a C~6 a1kenyl nitrite such as acrylonitrile or methacrylonitrile. The copolymerizable monomer may be a Cl 6 alkyl ester of a C~6 ethylenically unsaturated mono- or di- carboxylic acid. Preferred ester monomers include methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, and butyl acrylate. If the polymer contains monomers other than carboxylic acid groups then the carboxylic acids should be sufficientty neutralized to yield a water soluble polymer. Depending on the acid content in the copolymer the acid groups in the copolymers wilt be at least partially, preferably at least about 60%, more preferably over 80%, most preferably greater than 95 weight % neutralized, with an alkali or aL'Icaline earth metat or ammooia, ammonium hydroxide or a Cl4 alkyl primary amine, preferably with an alkali or a1kaline earth metal such as a sodium, potassium or catcium salt.
The water soluble polymer may be a polymer of a C~l2 vinyl monomer, which monomer is unsubstituted or substituted by a Cl4 atkyl radicat, which ~37~7 polymers have been sulphonated. Suitable monomers include styrene, alpha methyl styrene, p-methyl styrene, and t-butyl styrene. The polymers should be uncrosslinked or have such a low degree of crosslinking that they will be water soluble. The polymers are sulphonated. The polymers may be sulphonated with a sulphonadon agent such as sulphur trioxide or a sulphur trioxide o generation agent. However, care must be taken in the sulphonation reaction to minimize the development of crosslinks in the polymer. A par~cularly useful method of sulphonating vinyl aromatic polymers is to use a complex of su1phur trioxide or a sulphur trioxide generating agent such as oleum, and a tri-CI 4 a1kyl phosphate. Typically the sulphur trioxide and tri-alkyl phosphate may be used in a mole ratio from 1:4 to about 1:1. A useful process for sulphonating polystyrene is disclosed in United States Patent 3,205,285 in the name of Turbak et al issued September 13, 1965.
The water soluble polymer may be based on a naturat polymer. The polymer may be a cellulose derivative such as hydroxy ethyl cellulose or hydroxy propyl cellulose.
The water soluble polymer may be a polymer of one or more amides of C~6 ethylenically unsaturated carboxylic acids. The amide may be unsubstituted or substituted at the nitrogen by up to two C,4 alkyl radicals. Preferred amides include acrylamide and methacrylamide.
2~7~7 The water soluble polymer may be polyvinyl pyrrolidine or polyvinyl pyrrolidone.
The water soluble polymer may be poly glutamic acid.
The water soluble polymer may be polyethylene oxide.
To enhance the solubility properties of ~e water soluble layer, it may further comprise small amounts typically less ~an about 10, more preferably from 1 to 5 weight % of an agent which will help to dissolve the water soluble layer. Such agents include water soluble carbonates, secondary and tertiary phosphates, silicates, borates, and amines.
The relatively water insoluble layer comprises a polymer of one or more monomer residues of the Formula:
2 o -OCR~R2-(CR3R4)~-CO-wherein n is 0 or an integer from 1 to 5 and Rl, R2, R3, and R4 are independently selected the group consisting of a hydrogen atom and C14 a11y1 radicals.
The relatively water insoluble polymer may comprise a homopolymer of monomer residues of Formula I wherein n is 0 and one or Rl and R2 is a methyl radical and the other is a hydrogen atom. In such a case the polymer would be a homopolymer of lactic acid. Typically such polymers are prepared by a ring opening polymerization of lactide in the presence of a catalyst such as stannous octoate.
2 0 ~ 7 The relatively water insoluble polymer may comprise a homopolymer of monomer residues of Formula I wherein n is l, one of R, and R2 is a methyl radical and the other is a hydrogen atom and R3, and R4 are hydrogen atoms.
In this case the polymer would be a homopolymer of beta hydroxy bu~ric acid (PHB). Typica11y such polymers are produced by growing a microorganism in o a culture medium, typically under conditions imposing a strain on the microorganism so it can't metabolize the polymer. The polymer is then extracted from the microorganism.
The relatively water insoluble polymer may comprise a copolymer containing monomer residues of Formula I wherein n is 1, one of Rl and R2 is a methyl radical and the other is a hydrogen atom and R3, and R4 are hydrogen 20 atoms (e.g. residues of beta hydroxy butyric acid) and monomer residues of Formula I wherein n is 1, one of Rl and R2 is an ethyl radical and the other is a hydrogen atom and R3, and R4 are hydrogen atoms. In comonomer would be residues of hydroxy va1eric acid. The copolymer would be a copolymer of hydroxy-butyric and valeric add, sometimes referred to a PHBV. While there is no limitation on the ratio of butyric units to valeric units typically the weight ratio of C4 to C5 units can range from 90:10 to 10:90. In some instances it may be desirable to use a polymer having a weight ratio of C4 to C5 units from about 50:50 to about 90:10, more preferably from about 60:iO to 80:20.
2~7667 Each layer in the laminate may be from about 0.5 to 15, typically from about 0.5 to 10, most preferably from about 0.5 to 5 mils thick. The laminate may comprise more than two layers. For example, the laminate could comprise a water soluble polymer layer coated on each surface with a thinner water insoluble layer. Such a product would be suitable for example in a food wrapper or bag such as for car~dies etc. The outer water insoluble layer would biodegrade in the natural environment exposing the water soluble layer which would dissolve in water in the environment.
The laminates may be formed by a number of methods. The simplest method is by co-extrusion or extruding the water insoluble layer over one or more sheets of the water soluble layers. The water soluble polymers may be extruded at temperatures from about 150 up to about 200C. Care should be taken to avoid degrading the water soluble and relatively less water soluble polymers in the extrusion processes. Typica11y the extruders will operate at speeds from about 50 to 150 preferably from about 80 to 120 RPM's.
Genera11y the extruders will have a L:D ratio from about 24:1 to about 40:1.
In the alternative the laminate may be prepared by cast coating. The water soluUe polymer may be cast from water. The relatively less water soluUe polymer may be cast from a suitable organic solvent. For polylactic acid a useful solvent includes methylene chloride. The cast films may then be laminated together. In some instances, it may be desirable to treat one or more surfaces of one or more layers of the laminate with a solvent and/or an adhesive 2~7~7 to improve the bond between the layers of the laminate.
The layers used in the laminate may contain conventional additives such as, antioxidants, plasticizers, and fillers which may be either organic, ;norganic, fibrous or particulate. These types of additives are well known to those skilled in the art. Typically the fillers are used in amounts of up to about 60 preferably from about 30 to 50 weight ~. Particulate fillers may be inorganic fillers such as day, calcium car~onate, talc, mica, and the like. Fibrous fillers include natural fibers such as linen, cotton, and ~e like, and staple synthetic fibers such as polyolefin fibers, polyamide fibers, and polyester fibers. Organic fillers include cellulosic fillers, preferably selected from the group consisting of:
starch, functionalized starch, cellulose, functionalized cellulose, wood flour, 2o flour of nut shells, cotton and linen fibre, flock, or flour or a mixture thereof.
Particularly useful fillers may be selected from the group consisting of: starch, functionalized starch, a-cellulose, functionalized cellulose, wood flour and nut shell flour or a mixture thereof.
Antioxidants and plasticizers are typically used in very small amounts, typically in a total amount of not more than about 5 weight %. Such agents are 3 0 well known to those skilled in the art. It should also be noted that in some instances it may be desirable to use a polymeric softening agent such as the low molecular weight acrylate polymers (PARALOIDS) or even some rubbers as fixed plasticizers.
The present invention will now be illustrated by the following non-2~7~67 limiting examples in which unless otherwise indicated parts means parts byweight and % means weight %.
B~se Films Polylactic acid prepared by polymerizing lactide prepared from a monomer mixture comprising about 80 weight % of D, L isomer and about 20 weight % of the meso isomer was used as a base polymer for the relatively water less soluble polymer. The polylactic acid had an intrinsic viscosity of about 1Ø
The base polymer was dissolved in methylene chloride to make a 20%
solution. The 20% solution was then drawn down on an aluminum foil at a wet thickness of 1.5 mils. The film was dried 24 hours to give a dry film having a thickness of 0.8 to 0.9 mils thickness.
ExamD!e 1 A sma11 piece of teflon tape was placed in the center of each of four polylactide films prepared as described above. Two solutions of water soluble films were prepared. One solution was a 20% solution of polyvinyl acetate (available under the trademark MOWIOL0 æ-86) having a degree of hydrolysis of 88%. The other solution was a 20% solution of a sodium salt of a sulphonated polystyrene. Each of the above solutions were drawn down over duplicates of the base film on the side having the teflon tape. The solutions were drawn down at a wet thickness of 15 mils. The samples were dried for 24 hours. The polyvinyl acetate films when dry had a thickness of 3 to 5 mils and 2~57~
the sulphonated polystyrene film had a thickness of 1 to 3 mils. The laminates were then suspended above a beaker of water with either the water soluble side immersed in the water or the less water insoluble side immersed in the water.
The water was stirred using a magnetic stirrer. A stop watch was started when the sheet was immersed in the water. The time for the teflon tape to float free in the water was measured. The results are set forth in Table 1.
.
r_ Sulphonated Polystyrene 45 seconds lPolylactide (from PVA Laminate)1 hour/25 minutes Polylactide 45 minutes (from Sulphonated Polystyrene) _ __ The results ~how that the degradable polymers are capable of acting as water protective films.
The present invention relates to laminates of a water soluble polymer and a relatively water insoluble polymer. More particularly the present invention relates to laminates of a water soluUe polymer and a degradable relatively water insoluble polymer.
BACKGROUND OF T~ INVENTION
There are a number of uses of laminates or foils comprising a water soluble polymer and a relatively water insoluble polymer. One such use is in laundry hampers for hospita1s. Such hampers may be made of a relatively strong water soluble polymer. For the laundry hampers the outer layer is relative thick and provides most of the mechanical strength of the hamper. The 20 outer layer is also a water soluble polymer. When the hamper is placed in a washing machine the outer layer dissolves. The inner layer of the hamper is a relatively thin layer of insoluble polymer to protect the water soluble polymer from any dampness in the laundry. The full hamper is placed in a washing machine and the outer layer dissolves. The thin ifiner layer breaks under the mechanical action in the washing machine. The polymas are then discharged 30 with the water ~rom the washing machine. The hamper technology would also have potential use in the disposable diaper applications.
This technology might also be applicable in food packaging applications such as for foods which are moistened or cooked in water.
There are a series of patents in the name of Roland K. Belz which disclose similar laminates. In these patents the soluble layer comprises an acrylate polymer which is soluble only in alblline or acidic mediums.
Representative of such patents are United States Patent 4,261,066 issued April 14, 1981; United States Patent 4,469,728 issued September 4, 1984; and United States Patent 4,671,982 issued June 9, 1987. The Belz patents appear to be mainly concerned with the use of foils in sanitary applications such as covers for toilet seats.
Polyvinyl alcohol having a degrees of hydrolysis of greater than 80 weight % is soluble in either hot or cold water. Preferably the polyvinyl alcohol has a degree of hydrolysis of from 80 to 95 weight % so that it is cold water soluble. The properties of polyvinyl alcohol are discussed in Volume 23, page 849 of the Kirk Othmer Encyclopedia of Chemistry and Technology. One other advantage that polymers based on polyvinyl alcohol have is that they are biodegradable.
The polylactides, polyhydroxy butyrate and copolymers of beta hydroxy butyric acid, and beta hydroxy valeric acid are insoluble biodegradable polymers. To the best of applicant's knowledge these types of polymers have not been used in the above applications.
The present patent application seeks to provide additional water insoluble biodegradable polymer structures useful in the above applications.
20~7~67 SI~MARY OF T~ INVEN'IION
Accordingly, the present invention provides a laminate comprising one or more layers of one or more water soluble polymers and one or more layers of a relatively water insoluble polymer comprising residues of one or more monomers of the Formula:
-OCRIR2-(CR3R4)D-CO-wherein n is 0 or an integer from 1 to 5 and R" R2, R3, and R4 are independently selected the group consisting of a hydrogen atom and Cl 4 alkyl radicals.
VET~ILXD DESCRII'l'ION
The water soluble polymers useful in accordance with the present 2 o . invention may be selected frosn the group consisting of polyvinyl acetate having a molecular weight of not less than 30,000, preferably greater than 50,000 and a degree of saponification of not less than about 80%; polymers comprising:
(i) from 20 to l00 weight % of one or more C3 6 ethylenically unsaturated mono- or di- carboxylic acids;
(ii) 0 to 50 weight % of anhydrides of C46 dicarboxylic acids; and 30 (iii) from 0 to 80 weight % of one or more copolymerizable monomers;
provided that polymers containing monomers other than carboxylic acids or anhydrides thereof are sufficiently neutralized with an alkali or alkaline earthmetal or ammonia, ammonium hydroxide or a C~4 a1kyl primary amine to yield a water soluble polymer; soluble cellulose derivatives; polymers of C8 12 vinyl 2~7~67 aromatic monomers which polymers have been sulphonated; co and homopolymers of amides of C~6 ethylenically unsaturated carboxylic acids which amides are unsubstituted or substituted at the nitrogen atom by up to two radicals selected from the group consisting of Cl4 a1kyl radicals; polyvinyl pyrrolidine; polyvinyl pyrrolidone; and polyglutamic acid.
o Suitable water soluble polymers include vinyl acetate polymers having a molecular weight greater than about 30,000, more preferably greater than about 50,000. Preferably the polymers will have been saponified to not less than about80% most preferably to from about 87 to 90 weight % so that they are soluble in both hot and cold water. At a degree of saponification from 97 to 99 % the polyvinyl aclohol wi11 be soluble in hot water.
The water soluble polymer may be a co or homopolymer of one or more C~6 ethylenically unsaturated carboxylic acids and optionally anhydrides of C46 ethylenically unsaturated dicarboxylic acids. Preferred acids are acrylic and methacrylic acid. A preferred anhydride is mateic anhydride.
The water soluble polymer may be a copolymer comprising:
(i) from 20 to 100, preferably from 50 to 100, weight % of one or more of the above mono- or di- carboxylic acids;
Qi) from 0 to 50, preferably 0 to 20 weight % of anhydrides of C46 dicarboxylic acids; and (ii) from 0 to 80, preferably from 0 to 50, weight % of one or more copolymerizable monomers;
2~7~g7 provided that polymers containing monomers other than carboxylic acids or anhydrides thereof are sufficiently neutra1ized with an allcali or a1kaline earth metal or ammonia, ammonium hydroxide or a C,4 aL~cyl primary amine to yield a water soluble polymer.
Suitable copolymerizable monomers include C~l2 vinyl aromatic monomers which are unsubstituted or substituted by a Cl~ a1kyl radical such as styrene, ~-methyl styrene, p-methyl styrene, and t-butyl styrene. The comonomer may be a C~6 a1kenyl nitrite such as acrylonitrile or methacrylonitrile. The copolymerizable monomer may be a Cl 6 alkyl ester of a C~6 ethylenically unsaturated mono- or di- carboxylic acid. Preferred ester monomers include methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, and butyl acrylate. If the polymer contains monomers other than carboxylic acid groups then the carboxylic acids should be sufficientty neutralized to yield a water soluble polymer. Depending on the acid content in the copolymer the acid groups in the copolymers wilt be at least partially, preferably at least about 60%, more preferably over 80%, most preferably greater than 95 weight % neutralized, with an alkali or aL'Icaline earth metat or ammooia, ammonium hydroxide or a Cl4 alkyl primary amine, preferably with an alkali or a1kaline earth metal such as a sodium, potassium or catcium salt.
The water soluble polymer may be a polymer of a C~l2 vinyl monomer, which monomer is unsubstituted or substituted by a Cl4 atkyl radicat, which ~37~7 polymers have been sulphonated. Suitable monomers include styrene, alpha methyl styrene, p-methyl styrene, and t-butyl styrene. The polymers should be uncrosslinked or have such a low degree of crosslinking that they will be water soluble. The polymers are sulphonated. The polymers may be sulphonated with a sulphonadon agent such as sulphur trioxide or a sulphur trioxide o generation agent. However, care must be taken in the sulphonation reaction to minimize the development of crosslinks in the polymer. A par~cularly useful method of sulphonating vinyl aromatic polymers is to use a complex of su1phur trioxide or a sulphur trioxide generating agent such as oleum, and a tri-CI 4 a1kyl phosphate. Typically the sulphur trioxide and tri-alkyl phosphate may be used in a mole ratio from 1:4 to about 1:1. A useful process for sulphonating polystyrene is disclosed in United States Patent 3,205,285 in the name of Turbak et al issued September 13, 1965.
The water soluble polymer may be based on a naturat polymer. The polymer may be a cellulose derivative such as hydroxy ethyl cellulose or hydroxy propyl cellulose.
The water soluble polymer may be a polymer of one or more amides of C~6 ethylenically unsaturated carboxylic acids. The amide may be unsubstituted or substituted at the nitrogen by up to two C,4 alkyl radicals. Preferred amides include acrylamide and methacrylamide.
2~7~7 The water soluble polymer may be polyvinyl pyrrolidine or polyvinyl pyrrolidone.
The water soluble polymer may be poly glutamic acid.
The water soluble polymer may be polyethylene oxide.
To enhance the solubility properties of ~e water soluble layer, it may further comprise small amounts typically less ~an about 10, more preferably from 1 to 5 weight % of an agent which will help to dissolve the water soluble layer. Such agents include water soluble carbonates, secondary and tertiary phosphates, silicates, borates, and amines.
The relatively water insoluble layer comprises a polymer of one or more monomer residues of the Formula:
2 o -OCR~R2-(CR3R4)~-CO-wherein n is 0 or an integer from 1 to 5 and Rl, R2, R3, and R4 are independently selected the group consisting of a hydrogen atom and C14 a11y1 radicals.
The relatively water insoluble polymer may comprise a homopolymer of monomer residues of Formula I wherein n is 0 and one or Rl and R2 is a methyl radical and the other is a hydrogen atom. In such a case the polymer would be a homopolymer of lactic acid. Typically such polymers are prepared by a ring opening polymerization of lactide in the presence of a catalyst such as stannous octoate.
2 0 ~ 7 The relatively water insoluble polymer may comprise a homopolymer of monomer residues of Formula I wherein n is l, one of R, and R2 is a methyl radical and the other is a hydrogen atom and R3, and R4 are hydrogen atoms.
In this case the polymer would be a homopolymer of beta hydroxy bu~ric acid (PHB). Typica11y such polymers are produced by growing a microorganism in o a culture medium, typically under conditions imposing a strain on the microorganism so it can't metabolize the polymer. The polymer is then extracted from the microorganism.
The relatively water insoluble polymer may comprise a copolymer containing monomer residues of Formula I wherein n is 1, one of Rl and R2 is a methyl radical and the other is a hydrogen atom and R3, and R4 are hydrogen 20 atoms (e.g. residues of beta hydroxy butyric acid) and monomer residues of Formula I wherein n is 1, one of Rl and R2 is an ethyl radical and the other is a hydrogen atom and R3, and R4 are hydrogen atoms. In comonomer would be residues of hydroxy va1eric acid. The copolymer would be a copolymer of hydroxy-butyric and valeric add, sometimes referred to a PHBV. While there is no limitation on the ratio of butyric units to valeric units typically the weight ratio of C4 to C5 units can range from 90:10 to 10:90. In some instances it may be desirable to use a polymer having a weight ratio of C4 to C5 units from about 50:50 to about 90:10, more preferably from about 60:iO to 80:20.
2~7667 Each layer in the laminate may be from about 0.5 to 15, typically from about 0.5 to 10, most preferably from about 0.5 to 5 mils thick. The laminate may comprise more than two layers. For example, the laminate could comprise a water soluble polymer layer coated on each surface with a thinner water insoluble layer. Such a product would be suitable for example in a food wrapper or bag such as for car~dies etc. The outer water insoluble layer would biodegrade in the natural environment exposing the water soluble layer which would dissolve in water in the environment.
The laminates may be formed by a number of methods. The simplest method is by co-extrusion or extruding the water insoluble layer over one or more sheets of the water soluble layers. The water soluble polymers may be extruded at temperatures from about 150 up to about 200C. Care should be taken to avoid degrading the water soluble and relatively less water soluble polymers in the extrusion processes. Typica11y the extruders will operate at speeds from about 50 to 150 preferably from about 80 to 120 RPM's.
Genera11y the extruders will have a L:D ratio from about 24:1 to about 40:1.
In the alternative the laminate may be prepared by cast coating. The water soluUe polymer may be cast from water. The relatively less water soluUe polymer may be cast from a suitable organic solvent. For polylactic acid a useful solvent includes methylene chloride. The cast films may then be laminated together. In some instances, it may be desirable to treat one or more surfaces of one or more layers of the laminate with a solvent and/or an adhesive 2~7~7 to improve the bond between the layers of the laminate.
The layers used in the laminate may contain conventional additives such as, antioxidants, plasticizers, and fillers which may be either organic, ;norganic, fibrous or particulate. These types of additives are well known to those skilled in the art. Typically the fillers are used in amounts of up to about 60 preferably from about 30 to 50 weight ~. Particulate fillers may be inorganic fillers such as day, calcium car~onate, talc, mica, and the like. Fibrous fillers include natural fibers such as linen, cotton, and ~e like, and staple synthetic fibers such as polyolefin fibers, polyamide fibers, and polyester fibers. Organic fillers include cellulosic fillers, preferably selected from the group consisting of:
starch, functionalized starch, cellulose, functionalized cellulose, wood flour, 2o flour of nut shells, cotton and linen fibre, flock, or flour or a mixture thereof.
Particularly useful fillers may be selected from the group consisting of: starch, functionalized starch, a-cellulose, functionalized cellulose, wood flour and nut shell flour or a mixture thereof.
Antioxidants and plasticizers are typically used in very small amounts, typically in a total amount of not more than about 5 weight %. Such agents are 3 0 well known to those skilled in the art. It should also be noted that in some instances it may be desirable to use a polymeric softening agent such as the low molecular weight acrylate polymers (PARALOIDS) or even some rubbers as fixed plasticizers.
The present invention will now be illustrated by the following non-2~7~67 limiting examples in which unless otherwise indicated parts means parts byweight and % means weight %.
B~se Films Polylactic acid prepared by polymerizing lactide prepared from a monomer mixture comprising about 80 weight % of D, L isomer and about 20 weight % of the meso isomer was used as a base polymer for the relatively water less soluble polymer. The polylactic acid had an intrinsic viscosity of about 1Ø
The base polymer was dissolved in methylene chloride to make a 20%
solution. The 20% solution was then drawn down on an aluminum foil at a wet thickness of 1.5 mils. The film was dried 24 hours to give a dry film having a thickness of 0.8 to 0.9 mils thickness.
ExamD!e 1 A sma11 piece of teflon tape was placed in the center of each of four polylactide films prepared as described above. Two solutions of water soluble films were prepared. One solution was a 20% solution of polyvinyl acetate (available under the trademark MOWIOL0 æ-86) having a degree of hydrolysis of 88%. The other solution was a 20% solution of a sodium salt of a sulphonated polystyrene. Each of the above solutions were drawn down over duplicates of the base film on the side having the teflon tape. The solutions were drawn down at a wet thickness of 15 mils. The samples were dried for 24 hours. The polyvinyl acetate films when dry had a thickness of 3 to 5 mils and 2~57~
the sulphonated polystyrene film had a thickness of 1 to 3 mils. The laminates were then suspended above a beaker of water with either the water soluble side immersed in the water or the less water insoluble side immersed in the water.
The water was stirred using a magnetic stirrer. A stop watch was started when the sheet was immersed in the water. The time for the teflon tape to float free in the water was measured. The results are set forth in Table 1.
.
r_ Sulphonated Polystyrene 45 seconds lPolylactide (from PVA Laminate)1 hour/25 minutes Polylactide 45 minutes (from Sulphonated Polystyrene) _ __ The results ~how that the degradable polymers are capable of acting as water protective films.
Claims (44)
1. A laminate comprising one or more layers of one or more water soluble polymers and one or more layers of a relatively water insoluble polymer comprising of one or more monomer residues of the Formula:
-OCR1R2-(CR3R4)n-CO- I
wherein n is 0 or an integer from 1 to 5 and R1, R2, R3, and R4 are independently selected the group consisting of a hydrogen atom and C1-4 alkyl radicals.
-OCR1R2-(CR3R4)n-CO- I
wherein n is 0 or an integer from 1 to 5 and R1, R2, R3, and R4 are independently selected the group consisting of a hydrogen atom and C1-4 alkyl radicals.
2. The laminate according to claim 1 wherein said one or more water soluble polymers is selected from the group consisting of polyvinyl acetate having a molecular weight of not less than 30,000 and a degree of saponification of not less than about 80%; polymers comprising:
(i) from 20 to 100 weight % of one or more C3-6 ethylenically unsaturated mono- or di- carboxylic acids, (ii) from 0 to 50 weight 96 of anhydrides of C4-6 dicarboxylic acids; and (iii) from 0 to 80 weight % of one or more copolymerizable monomers;
provided that polymers containing monomers other than carboxylic acids or anhydrides thereof are sufficiently neutralized with an alkali or alkaline earth metal or ammonia, ammonium hydroxide or a C1-4 alkyl primary amine to yield a water soluble polymer; soluble cellulose derivatives; polymers of C8-l2 vinyl aromatic monomers which polymers have been sulphonated; co and homopolymers of amides of C3-6 ethylenically unsaturated carboxylic acids which amides are unsubstituted or substituted at the nitrogen atom by up to two radicals selected from the group consisting of C1-4 alkyl radicals; polyvinyl pyrrolidine; polyvinyl pyrrolidone; polyglutamic acid; and polyethylene oxide.
(i) from 20 to 100 weight % of one or more C3-6 ethylenically unsaturated mono- or di- carboxylic acids, (ii) from 0 to 50 weight 96 of anhydrides of C4-6 dicarboxylic acids; and (iii) from 0 to 80 weight % of one or more copolymerizable monomers;
provided that polymers containing monomers other than carboxylic acids or anhydrides thereof are sufficiently neutralized with an alkali or alkaline earth metal or ammonia, ammonium hydroxide or a C1-4 alkyl primary amine to yield a water soluble polymer; soluble cellulose derivatives; polymers of C8-l2 vinyl aromatic monomers which polymers have been sulphonated; co and homopolymers of amides of C3-6 ethylenically unsaturated carboxylic acids which amides are unsubstituted or substituted at the nitrogen atom by up to two radicals selected from the group consisting of C1-4 alkyl radicals; polyvinyl pyrrolidine; polyvinyl pyrrolidone; polyglutamic acid; and polyethylene oxide.
3. The laminate according to claim 2, wherein said layers have a thickness from 0.5 to 15 mils thick.
4. The laminate according to claim 3, wherein in said relatively water insoluble polymer is a homopolymer of Formula I wherein n is 0 and one of R1 and R2 is a hydrogen atom and the other is a methyl radical.
5. The laminate according to claim 4, wherein said water soluble polymer is selected from the group consisting of hydroxyethyl cellulose and hydroxypropyl cellulose.
6. The laminate according to claim 4, wherein said water soluble polymer is a co or homopolymer of acrylic acid and methacrylic acid.
7. The laminate according to claim 4 wherein said one or more water soluble polymers comprises:
(i) from 20 to 100 weight % of one or more C3-6 ethylenically unsaturated mono- or di- carboxylic acids, (ii) from 0 to 20 weight % of anhydrides of C4-6 dicarboxylic acids; and (iii) from 0 to 80 weight % of one or more copolymerizable monomers;
provided that polymers containing monomers other than carboxylic acids or anhydrides thereof are sufficiently neutralized with an alkali or alkaline earth metal or ammonia, ammonium hydroxide or a C1-4 alkyl primary amine to yield a water soluble polymer.
(i) from 20 to 100 weight % of one or more C3-6 ethylenically unsaturated mono- or di- carboxylic acids, (ii) from 0 to 20 weight % of anhydrides of C4-6 dicarboxylic acids; and (iii) from 0 to 80 weight % of one or more copolymerizable monomers;
provided that polymers containing monomers other than carboxylic acids or anhydrides thereof are sufficiently neutralized with an alkali or alkaline earth metal or ammonia, ammonium hydroxide or a C1-4 alkyl primary amine to yield a water soluble polymer.
8. The laminate according to claim 7, wherein said one or more copolymerizable monomers are selected from the group consisting of C8-12 vinyl aromatic monomers which are unsubstituted or substituted by a C1-4 alkyl radical; C3-6 alkenyl nitriles; and C1-6 alkyl ester of a C3-6 ethylenically unsaturated mono- or di- carboxylic acids.
9. The laminate according to claim 8, wherein said acid is selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, and fumaric acid; said dicarboxylic acid is maleic acid; said anhydride is maleic anhydride;
and said one or more copolymerizable monomers are selected from the group consisting of styrene, .alpha.-methyl styrene, p-methyl styrene, t-butyl styrene, acrylonitrile, methacrylonitrile, methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, and butyl acrylate.
and said one or more copolymerizable monomers are selected from the group consisting of styrene, .alpha.-methyl styrene, p-methyl styrene, t-butyl styrene, acrylonitrile, methacrylonitrile, methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, and butyl acrylate.
10. The laminate according to claim 4, wherein said water soluble polymer comprises sulphonated polystyrene.
11. The laminate according to claim 4, wherein said water soluble polymer comprises one or more monomers selected from the group consisting of acrylamide, and methacrylamide,
12. The laminate according to claim 4, wherein said water soluble layer further comprises an agent selected from the group consisting of: water-soluble carbonates, secondary and tertiary phosphates, silicates, borates, and amines.
13. The laminate according to claim 3, wherein in said relatively water insoluble polymer is a homopolymer of Formula I wherein n is 1 and one of R1 and R2 is a hydrogen atom and the other is a methyl radical and R3 and R4, are hydrogen atoms.
14. The laminate according to claim 13, wherein said water soluble polymer is selected from the group consisting of hydroxyethyl cellulose and hydroxypropyl cellulose.
15. The laminate according to claim 13, wherein said water soluble polymer is a co or homopolymer of acrylic acid and methacrylic acid.
16. The laminate according to claim 13, wherein said one or more water soluble polymers comprises:
(i) from 20 to 100 weight % of one or more C3-6 ethylenically unsaturated mono- or di- carboxylic acids, (ii) from 0 to 20 weight % of anhydrides of C4-6 dicarboxylic acids; and (iii) from 0 to 80 weight % of one or more copolymerizable monomers;
provided that polymers containing monomers other than carboxylic acids or anhydrides thereof are sufficiently neutralized with an alkali or alkaline earth metal or ammonia, ammonium hydroxide or a C1-4 alkyl primary amine to yield a water soluble polymer.
(i) from 20 to 100 weight % of one or more C3-6 ethylenically unsaturated mono- or di- carboxylic acids, (ii) from 0 to 20 weight % of anhydrides of C4-6 dicarboxylic acids; and (iii) from 0 to 80 weight % of one or more copolymerizable monomers;
provided that polymers containing monomers other than carboxylic acids or anhydrides thereof are sufficiently neutralized with an alkali or alkaline earth metal or ammonia, ammonium hydroxide or a C1-4 alkyl primary amine to yield a water soluble polymer.
17. The laminate according to claim 16, wherein said one or more copolymerizable monomers are selected from the group consisting of C8-l2 vinyl aromatic monomers which are unsubstituted or substituted by a C1-4 alkyl radical; C3-6 alkenyl nitriles; and C1-6 alkyl ester of a C3-6 ethylenically unsaturated mono- or di- carboxylic acids.
18. The laminate according to claim 17, wherein said acid is selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, and fumaric acid; said dicarboxylic acid is maleic acid; said anhydride is maleic anhydride;
and said one or more copolymerizable monomers are selected from the group consisting of styrene, .alpha.-methyl styrene, p-methyl styrene, t-butyl styrene, acrylonitrile, methacrylonitrile, methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, and butyl acrylate.
and said one or more copolymerizable monomers are selected from the group consisting of styrene, .alpha.-methyl styrene, p-methyl styrene, t-butyl styrene, acrylonitrile, methacrylonitrile, methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, and butyl acrylate.
19. The laminate according to claim 13, wherein said water soluble polymer comprises sulphonated polystyrene.
20. The laminate according to claim 13, wherein said water soluble polymer comprises one or more monomers selected from the group consisting of acrylamide and methacrylamide.
21. The laminate according to claim 13, wherein said water soluble layer further comprises an agent selected from the group consisting of: water-soluble carbonates, secondary and tertiary phosphates, silicates, borates, and amines.
22. The laminate according to claim 3, wherein in said relatively water insoluble polymer is a copolymer of monomer residues of Formula I wherein n is 1 and one of R1 and R2 is a hydrogen atom and the other is a methyl radical and R3 and R4, are hydrogen atoms of monomer residues of Formula I wherein n is 2 and one or R1 and R2 is a hydrogen atom and the other is a methyl radical and R3 and R4 are hydrogen atoms.
23. The laminate according to claim 22, wherein said water soluble polymer is selected from the group consisting of hydroxyethyl cellulose and hydroxypropyl cellulose.
24. The laminate according to claim 22, wherein said water soluble polymer is a co or homopolymer of acrylic acid and methacrylic acid.
25. The laminate according to claim 22 wherein said one or more water soluble polymers comprises:
(i) from 20 to 100 weight % of one or more C3-6 ethylenically unsaturated mono- or di- carboxylic acids, (ii) from 0 to 20 weight % of anhydrides of C4-6 dicarboxylic acids; and (iii) from 0 to 80 weight % of one or more copolymerizable monomers;
provided that polymers containing monomers other than carboxylic acids or anhydrides thereof are sufficiently neutralized with an alkali or alkaline earth metal or ammonia, ammonium hydroxide or a C1-4 alkyl primary amine to yield a water soluble polymer.
(i) from 20 to 100 weight % of one or more C3-6 ethylenically unsaturated mono- or di- carboxylic acids, (ii) from 0 to 20 weight % of anhydrides of C4-6 dicarboxylic acids; and (iii) from 0 to 80 weight % of one or more copolymerizable monomers;
provided that polymers containing monomers other than carboxylic acids or anhydrides thereof are sufficiently neutralized with an alkali or alkaline earth metal or ammonia, ammonium hydroxide or a C1-4 alkyl primary amine to yield a water soluble polymer.
26. The laminate according to claim 22, wherein said one or more copolymerizable monomers are selected from the group consisting of C8-12 vinyl aromatic monomers which are unsubstituted or substituted by a C1-4 alkyl radical; C3-6 alkenyl nitriles; and C1-6 alkyl ester of a C3-6 ethylenically unsaturated mono- or di- carboxylic acids.
27. The laminate according to claim 26, wherein said acid is selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, and fumaric acid; said dicarboxylic acid is maleic acid; said anhydride is maleic anhydride;
and said one or more copolymerizable monomers are selected from the group consisting of styrene, .alpha.-methyl styrene, p-methyl styrene, t-butyl styrene, acrylonitrile, methacrylonitrile, methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, and butyl acrylate.
and said one or more copolymerizable monomers are selected from the group consisting of styrene, .alpha.-methyl styrene, p-methyl styrene, t-butyl styrene, acrylonitrile, methacrylonitrile, methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, and butyl acrylate.
28. The laminate according to claim 22, wherein said water soluble polymer comprises sulphonated polystyrene.
29. The laminate according to claim 22, wherein said water soluble polymer comprises one or more monomers selected from the group consisting of acrylamide and methacrylamide.
30. The laminate according to claim 22, wherein said water soluble layer further comprises an agent selected from the group consisting of: water-soluble carbonates, secondary and tertiary phosphates, silicates, borates, and amines.
31. The laminate according to claim 3, wherein in said relatively water insoluble polymer is a copolymer of Formula I wherein n is 1 and one of R1 and R2 is a hydrogen atom and the other is a methyl radical, and residues of Formula I wherein n is 1, and one of R1 and R2 is hydrogen and the other ethyl and R3 and R4 are hydrogen.
32. The laminate according to claim 31, wherein said water soluble polymer is selected from the group consisting of hydroxyethyl cellulose and hydroxypropyl cellulose.
33. The laminate according to claim 31, wherein said water soluble polymer is a co or homopolymer of acrylic acid and methacrylic acid.
34. The laminate according to claim 31 wherein said one or more water soluble polymers comprises:
(i) from 20 to 100 weight % of one or more C3-6 ethylenically unsaturated mono- or di-carboxylic acids, (ii) from 0 to 20 weight % of anhydrides of C4-6 dicarboxylic acids; and (iii) from 0 to 80 weight % of one or more copolymerizable monomers;
provided that polymers containing monomers other than carboxylic acids or anhydrides thereof are sufficiently neutralized with an alkali or alkaline earth metal or ammonia, ammonium hydroxide or a C1-4 alkyl primary amine to yield a water soluble polymer.
(i) from 20 to 100 weight % of one or more C3-6 ethylenically unsaturated mono- or di-carboxylic acids, (ii) from 0 to 20 weight % of anhydrides of C4-6 dicarboxylic acids; and (iii) from 0 to 80 weight % of one or more copolymerizable monomers;
provided that polymers containing monomers other than carboxylic acids or anhydrides thereof are sufficiently neutralized with an alkali or alkaline earth metal or ammonia, ammonium hydroxide or a C1-4 alkyl primary amine to yield a water soluble polymer.
35. The laminate according to claim 34, wherein said one or more copolymerizable monomers are selected from the group consisting of C8-l2 vinyl aromatic monomers which are unsubstituted or substituted by a C1-4 alkyl radical; C3-6 alkenyl nitriles; and C1-6 alkyl ester of a C3-6 ethylenically unsaturated mono- or di- carboxylic acids.
36. The laminate according to claim 35, wherein said acid is selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, and fumaric acid; said dicarboxylic acid is maleic acid; said anhydride is maleic anhydride;
and said one or more copolymerizable monomers are selected from the group consisting of styrene, .alpha.-methyl styrene, p-methyl styrene, t-butyl styrene, acrylonitrile, methacrylonitrile, methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, and butyl acrylate.
and said one or more copolymerizable monomers are selected from the group consisting of styrene, .alpha.-methyl styrene, p-methyl styrene, t-butyl styrene, acrylonitrile, methacrylonitrile, methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate, and butyl acrylate.
37. The laminate according to claim 31, wherein said water soluble polymer comprises sulphonated polystyrene.
38. The laminate according to claim 31, wherein said water soluble polymer comprises one or more monomers selected from the group consisting of acrylamide and methacrylamide.
39. The laminate according to claim 31, wherein said water soluble layer further comprises an agent selected from the group consisting of: water-soluble carbonates, secondary and tertiary phosphates, silicates, borates, and amines.
40. The laminate according to claim 4, wherein said layer of said relatively water insoluble polymer comprises up to 60 weight % of an organic filler selected from the group consisting of: starch, functionalized starch, cellulose, functionalized cellulose, wood flour, flour of nut shells, cotton and linen fibre, flock, or flour or a mixture thereof.
41. The laminate according to claim 4, wherein said waster soluble layer comprises polyvinyl acetate having a molecular weight of not less than 50,000 and a degree of saponification of not less than 80%.
42. The laminate according to claim 13, wherein said waster soluble layer comprises polyvinyl acetate having a molecular weight of not less than 50,000 and a degree of saponification of not less than 80%.
43. The laminate according to claim 22, wherein said waster soluble layer comprises polyvinyl acetate having a molecular weight of not less than 50,000 and a degree of saponification of not less than 80%.
44. The laminate according to claim 31, wherein said waster soluble layer comprises polyvinyl acetate having a molecular weight of not less than 50,000 and a degree of saponification of not less than 80%.
TT/SP-US.033
TT/SP-US.033
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2057667 CA2057667A1 (en) | 1991-12-13 | 1991-12-13 | Laminates |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2057667 CA2057667A1 (en) | 1991-12-13 | 1991-12-13 | Laminates |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2057667A1 true CA2057667A1 (en) | 1993-06-14 |
Family
ID=4148935
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2057667 Abandoned CA2057667A1 (en) | 1991-12-13 | 1991-12-13 | Laminates |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2057667A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5525706A (en) * | 1992-10-02 | 1996-06-11 | Cargill, Incorporated | Melt-stable lactide polymer nonwoven fabric and process for manufacture thereof |
-
1991
- 1991-12-13 CA CA 2057667 patent/CA2057667A1/en not_active Abandoned
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5525706A (en) * | 1992-10-02 | 1996-06-11 | Cargill, Incorporated | Melt-stable lactide polymer nonwoven fabric and process for manufacture thereof |
| US5807973A (en) * | 1992-10-02 | 1998-09-15 | Cargill, Incorporated | Melt-stable lactide polymer nonwoven fabric and process for manufacture thereof |
| US6111060A (en) * | 1992-10-02 | 2000-08-29 | Cargill, Incorporated | Melt-stable lactide polymer nonwoven fabric and process for manufacture thereof |
| US6355772B1 (en) | 1992-10-02 | 2002-03-12 | Cargill, Incorporated | Melt-stable lactide polymer nonwoven fabric and process for manufacture thereof |
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| EEER | Examination request | ||
| FZDE | Discontinued | ||
| FZDE | Discontinued |
Effective date: 20001213 |