MXPA01006367A - Plastic articles comprising biodegradable pha copolymers - Google Patents

Abstract

The present invention relates to biodegradable PHA copolymers comprising at least two randomly repeating monomer units. The present invention further relates to a plastic article comprising a biodegradable copolymer, wherein the biodegradable copolymer comprises at least two randomly repeating monomer units (RRMU) wherein the first RRMU has structure (I), wherein R1 is H, or C1 or C2 alkyl, and n is 1 or 2;the second RRMU has structure (II) and wherein at least 50%of the RRMUs have the structure of the first RRMU. The present invention further relates to an absorbent article comprising a liquid pervious topsheet, a liquid impervious backsheet comprising a film comprising a PHA of the present invention and an absorbent core copositioned between the topsheet and the backsheet.

Description

PLASTIC ITEMS COMPRISING PHA BIODEGRADABLE COPOLYMERS TECHNICAL FIELD The present invention relates to biodegradable PHA copolymers and plastic articles comprising these biodegradable PHA copolymers.

BACKGROUND DK THE RENEWAL Polymers find uses in a variety of plastic items including films, sheets, fibers, flutes, molded articles, adhesives and many other specialized products. For applications in the areas of packaging, agriculture, household goods and personal care products, polymers usually have a cycle of use ceno (monkeys of 12 meees). For example, in food packaging, polymers play a role as a protective agent and are quickly discarded after the contents are consumed. Domestic products such as bottles for and parales are discarded once the product is used.

* Most of this plastic material ends up in the stream of solid waste, directed to disappear quickly and to an increasingly expensive landfill site. While some efforts have been made to recycle, the nature of the polymers and the way they are produced and converted to products limit the number of applications for recycling possible. The repeated processing even of pure polymers results in the degradation of the material and consequently in poor mechanical properties. Different grades of chemically similar plastics (eg, polyethylenes of different molecular weights, as used in bed jars and grocery bags) mixed at the time of collection may cause processing problems that cause the recovered material to be inferior or inutile. ilizable. The applications of absorbent articles such as diapers, sanitary napkins, tampons and the like, involve several different types of plastics. In these cases, recycling is particularly expensive due to the difficulty in separating the different components. Disposable products of this type generally comprise some 8 ~ &"fluid-permeable upper material material class, an absorbent core, and a fluid-impermeable reinforcing canvas material. Heretofore, these absorbent structures have been prepared using, for example, upper canvas materials prepared from polyethylene or polypropylene materials with formed, woven, non-woven, or porous film. Reinforcing canvas materials typically comprise flexible polyethylene sheets. The absorbent core materials typically comprise wood pulp fibers or wood pulp fibers in combination with absorbent gelling materials. Although these products broadly comprise materials that could be expected to eventually degrade, and although products of this type contribute only a very small percentage of the total solid waste materials generated by consumers each year, they do not. There is a need to invent - these disposable products from materials that are capable of composting or compost. A disposable absorbent product. conventional is already a product with the capacity to form fertilizer to a greater degree. A disposable diaper, for example, consists of approximately 80% of materials that can form compost, for example, wood pulp fibers, and the like. In the composting process, the dirty disposable absorbent articles are comminuted and mixed with the organic waste prior to the formation of fertilizer per se. After fertilizer formation is completed, particles that can not form compost are removed by screening. In this way, even today, absorbent articles can be processed successfully in commercial plants for the formation of fertilizer. However, there is a need to network the amount of materials that can not form compost in the disposable absorbent articles. There is a particular need to replace the polyethylene reinforcement canvases in the absorbent articles with liquid impervious films of material that can form, fertilizer, because the reinforcing canvas typically is one with the components that can not form larger fertilizer. of a conventional disposable absorbent article. In addition-to have the ability to form compost, the films used as reinforcement canvases for absorbent articles must meet many other requirements d &; performance. For example, resins must be thermoplastic in such a way that they can be used - methods for conventional film processing. These methods include the extrusion of molten film and blown film of single layer structures and the extrusion of melted or blown film of multilayer structures. Other methods include extrusion coating a material on one or both sides of a substrate that can form compost such as, for example, another film, a woven fabric or a paper web. Still other properties are essential in the operations for conveying products, where films are used to manufacture absorbent articles. Properties such as tensile strength, tensile modulus, tear resistance, and thermal softening point determine a greater degree of how well a film will run over the conversion lines. In addition to the properties mentioned above, they are. other properties still needed to meet the requirements of the end user of the absorbent article. The properties of the film such as impact resistance, puncture resistance, and moisture transmission are important as they influence the durability and containment of the absorbent article while it is being used. Once the absorbent article is discarded and enters a process for composting, other properties become important. Regardless of whether the incoming waste is pre-shredded or not, it is important that the film or large fragments of the film go through an initial break to very small particles during the early stages of composting. The films of large fragments can be extracted by screening the fertilizer stream and will never become part of the final fertilizer In the past, the biodegradability and physical properties of a variety of polyhydroxyalkanoates (PHAs) have been studied. Polyhydroxyalkanoates are polyester compounds produced by a variety of microorganisms, such as bacteria and algae.While polyhydroxyalkanoates have been of general interest due to their biodegradable nature, their current use as a plastic material has been hampered by their thermal instability. For example, poly-3-hydroxyborate (PHB) is a product for natural energy storage. to bacteria and algae, and is present in discrete granules within the cell-cytoplasm. However, unlike other biologically synthesized polymers such as proteins and polysaccharides, PHB is thermoplastic having a high degree of crystallinity and a well-defined melting temperature of about 180 ° C. Unfortunately, PHB becomes unstable and Due to this thermal instability, commercial applications of PHB have been limited to extreme temperatures, as a result, the researchers hCn studied other polyhydroxyalkanoates such as poly (3-hydroxybutyrate). -co-3-hydroxyvalerate) (PHBV), in the hope of discovering a polyhydroxyalkanoate having sufficient thermal stability and other chemical and physical properties suitable for use in practical applications Unfortunately, polyhydroxyalkanoates such as PHB and PHBV are difficult to process in suitable films for canvas reinforcement applications. previously, the thermal instability of the PHB causes this. processing is almost impossible. In addition, the slow crystallization rates and the flow properties of PHB and PHBV make film processing difficult. Examples of PHB homopolymer and PHBV copolymers are described in U.S. Patent 4,393,167, Holmes et al., Issued July 12, 1983, and U.S. Patent 4,880,592, issued November 14, 1989. Copolymers of PHBV are commercially available from Imperial Chemical Industries under the trade name BIOPOL. PHBV copolymers are currently produced with valerate contents ranging from about 5 to 24 mol%. Increasing the valerate content decreases the melting temperature, crystallinity and polymer stiffness. A summary of the BIOPOL technology in BUSINESS 2000í (Winter 1990) is provided. Due to the slow rate of crystallization, a film made of PHBV will adhere to itself even after cooling; A substantial fraction of PHBV remains amorphous and viscous for long periods of time. In the molten film operations, where the film is immediately cooled on refrigerant rollers after leaving the film matrix, the molten PHBV often adheres to the rollers restricting the speed at which the film can be processed, or even avoiding that the film can be collected. In blown films, the residual viscosity of the PHBV causes the > Tubular film will adhere to itself after it has cooled and collapsed for winding. U.S. Patent 4,880,592, Ilartini et al., Issued November 14, 1989, discloses a means to achieve a PHBV monolayer film for diaper reinforcement canvas applications by coextruding PHBV between two layers of sacrificial polymer. , for example, a polyolefin, stretching and orienting the multilayer film and then removing the polyolefin layers after the PHBV has had time to crystallize. The remaining PHBV film is then laminated to either water soluble films or water insoluble films such as polyvinylidone chloride or other polyolefins. Unfortunately, these drastic and annoying processing measures are necessary in an attempt to identify the inherent difficulties associated with the processing of PHBV in films.

Based on the above, there is a need for plastic items that can biodegrade. In fact, these biodegradable articles could facilitate the "recycling" of plastic articles in another product that can be used, humus, through the formation of fertilizer. To meet this need, there is a preliminary need for a biodegradable polymer that has the ability to be easily processed in a plastic article for use in a disposable product.

OBJECTIVES OF THE INVENTION An object of the present invention is to provide a biodegradable polyhydroxyalkanoate (PHA) copolymer. An object of the present invention is also to provide plastic articles comprising a biodegradable polyhydroxyalkanoate (PHA). An object of the present invention is also to provide a method for using a biodegradable polyhydro Lal canoate (PHA) to produce plastic articles, *. An object of the present invention is also to provide a disposable sanitary undergarment comprising a film consisting of a biodegradable polyhydroxyalkanoate (PHA).

BRIEF DESCRIPTION D? THE INVENTION The present invention relates to biodegradable and novel polyhydroxyalkanoate (PHA) copolymers, which comprise at least two randomly repeating monomer units. The present invention is further related to plastic articles comprising a biodegradable cope polymer, wherein the copolymer comprises at least two randomly repeating monomer units, wherein the first monomer unit has the structure wherein R1 is H, or Ci or C2 alkyl, and n is 1 or 2; the second monomeric unit has the structure ~ { and wherein at least 50% of the monomer units of random repetition have the structure of the first monomeric unit. These plastic articles include films, sheets, fibers, foams, molded articles, non-woven fabrics, elastomers, and adhesives. The present invention furthermore relates to an absorbent article comprising a liquid permeable top sheet, a biodegradable liquid impermeable backing sheet comprising a film consisting of a biodegradable PHA and an absorbent core placed between the top canvas and the lie of reinforcement.

DETAILED DESCRIPTION The present invention responds to the need for a biodegradable copolymer having the ability to be easily processed in a plastic article. The present invention also responds to the need for disposable plastic articles with a biodegradability and / or capacity to form increased fertilizer. In the sense in which it is used in the present, "ASTM" means American Society for Testing and Materials.

At. In the sense in which it is used in the present, "comprising" means that other steps and other ingredients may be added that do not affect the final result. This term encompasses the terms "consisting of" and "consisting essentially of". In the sense in which it is used herein, "alkyl" means a chain containing saturated carbon which may be straight or branched; and situitu (mono- or poly-) or unsubstituted. As used herein, "alkenyl" means a carbon-containing chain that can be monounsaturated (ie, a double bond in the chain) or oli-unsaturated (that is, two or more) double links in the chain); straight or branched; and substituted (mono- or poly-) or unsubstituted. In the sense in which it is used herein, "PHA" means a polyhydroxyalkane or la. present invention. In the sense in which it is used in the present, "PHB" means the homopolymer poly- (3-hydroxybutyl).

As used herein, "PHBV" means the copolymer poly (3-hydroxybutyrate-co-3'-hydroxyvalerate). In the sense in which it is used herein, "PHBMV" means the copolymer poly (3-hydroxybutyrate-co-3-hydroxy-methyl-1-valerate). In the sense in which it is used herein, "biodegradable" means the ability of a compound to eventually degrade by completing C02 and water or biomass by microorganisms and / or natural environmental factors. In the sense in which it is used herein, "capacity to form compost" means a material that meets the following three requirements: (1) the material is capable of being processed in a facility for compost formation for solid waste; (2) if it is processed like this * the material will end up in the fertilizer badly; and (3) if the fertilizer is used in the soil, the material will eventually biodegrade in the soil. For example, a material of polymeric film present in a solid waste subject to an installation for compost formation for processing does not necessarily end in the final subscription. Certain composting facilities subject the stream of solid waste to air classification prior to the additional • processing, in order to separate the paper and other materials. A polymer film could most likely be separated from the stream of solids in this air classification and therefore will not be processed in the installation for compost formation. However, this can still be a material "with the capacity to form fertilizer" according to the above definition because it is "capable" of being processed in a facility for fertilizer formation. The requirement that the material end up in the final fertilizer typically means that it undergoes a form of degradation in the process for composting. Typical, the stream of solid waste will be subjected to an aesmenuzamiento step in a phase prior to the composting process. As a result, the polymer film will be present as fragments instead of a sheet. In the final stage of the fertilizer formation process, the finished fertilizer will undergo a screening step. Typically, the polymer fragments will not pass through screens if they maintain the size they imately had after the comminution step. The compostable materials of the present invention will have quite a loss in integrity during the composting process to allow partially degraded fragments to pass through the screens. However, it can be envisaged that an installation for composting training could subject the stream of solid waste to a very rigorous shredding and preferably a screening by slab, in which case non-degradable polymers such as polyethylene could meet the requirement (2). ). Therefore, complying with the requirement (2) is not sufficient for a material that will have the capacity to form fertilizer within the present definition. What distinguishes the material that can form fertilizer as defined in the present material similar to polyethylene is the requirement (3j, that the material is ultimately biodegraded in the soil.) This requirement of biodegradability is not essential for the process for the formation of fertilizer or the use of the soil for compost formation Solid waste and the resulting fertilizer may contain all types of non-biodegradable materials, eg sand, however, to avoid an accumulation of man-made materials in the In this case, it is required that these materials be completely biodegradable, it is not absolutely necessary for this biodegradation to be rapid, since the material itself and the interate decomposition products are not toxic or otherwise harmful to the environment. soil or crops, it is completely acceptable that its biodegradation takes several months or even years, since this requirement is present only to avoid an accumulation of man-made materials in the usual. All polymer composition proportions noted herein refer to molar proportions, unless specifically indicated otherwise. The present invention relates to biodegradable copolymers which can surprisingly be processed easily in plastic articles, in particular in films compared to the PHB homopolymer and the PHBV copolymer. As used herein, "plastic article" means a copolymer processed into a film, sheet, fiber, foam, molded article, non-woven fabric, elastomer or adhesive. The PHAs useful for the processing in plastic articles of the present invention comprise at least two randomly repeating monomer units (RRMU) * The first RRMU has the structure where R1 is H, or Ci or C2 alkyl and n is 1 or 2 The second RRMU has the structure In one embodiment of the present invention, at least about 50%, but less than 100%, of the RRMU have the structure of the first RRMU, more preferably at least about 60%, most preferably at least about 70%; still more preferably at least about 80%, most preferably at least about 90%.

* When a PHA of the present invention is processed into a film, sheet, or soft elastic fiber, preferably between about 50% and 99.9% of the RRMU, they have the structure of the first RRMU unit; more preferably between about 75% and 99%; even more preferably between about 85% and 98%; most preferably between about 85% and 95%. When a PHA of the present invention is processed into a normal fiber or molded article (eg, injected or blow molded), preferably between about 80% and 99.5% of the first RRMU have the structure of the first RRMU; more preferably between about 90% and 99.5%; even more preferably between about 95% and 99.5%. When a PHA of the present invention is processed in an elastomer or an adhesive, preferably between about 50% and 85% of the RRMU have the structure of the first RRMU. When a PHA of the present invention. it is processed in a non-woven product, preferably between approximately 85% and p9.5% of the RRMU have the structure • of the first RRMU; more preferably between about 90% and '99.5%; of '# I still greater preference of between approximately 95% and 99.5%. In one embodiment of the present invention, R1 is Ci alkyl and n is 1, thereby forming the monomeric repeat unit 3-hydroxybutyrate. In another embodiment of the present invention, R1 is a C2 alkyl and n is -l, thereby forming the monomeric repeat unit 3-hydroxyvalerate. In another embodiment of the present invention, R1 ^ is H and n is 2, thereby forming the monomeric repeat unit 4-hydroxyluthira or. In another embodiment of the present invention, R1 is H and n is 1, thereby forming the monomeric repeat unit 3-hydroxypropionate. In another embodiment, the copolymer useful in the present invention comprises one or more additional RRMU having the structure wherein R3 is H, or an alkyl or alkenyl of Cl f C2, C31- C, C ^, Ce, C7, Cs, C, CID, Cu, C12, C13 / C1, C15, C3.6 / Cp, C18 / o C1; and m is 1 or 2; and where the additional RRMUs are not equal to the first RRMU or the second RRMU. Preferably, the copolymer comprises 3, 4, 5, 6, 1, Q f 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 or more different RRMU. In a preferred embodiment of the present invention, R3 is an alkyl or alkenyl of Ci, C2, C3, C4, C5, e, C7, Cs, Cg, C, Cu, 12, C13, C? 4, C15, ±? , u, Cis, or C? 9; and m is 1. In a preferred embodiment of the present invention, R3 is an alkyl of Ci and m is 1, thereby forming the monomeric repeat unit 3-hydroxybutyrate. In another embodiment of the present invention, R3 is an alkyl of C.C2 and m is 1, thereby forming the monomeric repeat unit 3-hydroxyvalerate. In another embodiment of the present invention, R3 is H and m is 2, thereby forming the monomeric repeat unit 4 -hydroxybutyrate. In another embodiment of the present invention, R3 is H and m is 1, thereby forming the monomeric repeat unit 3-hydroxypropionate. Preferably, the novel, biodegradable PHAs of the present invention comprising the two RRMUs have a first RRMU having the structure wherein R1 is H, or Ci or C2 alkyl, and n is 1 or 2; and a second RRMU that has the structure where at least 50% of the RRMU have the structure of the first RRMU. Preferably, the novel biodegradable PHAs of the present invention, which comprise three RRMUs, have a first RRMU having the structure wherein R is H, or alkyl or alkenyl of Ci or C2 and n is 1 or 2; a second RRMU that has the structure CH3 I CH-CH3 O i II -O-CH- CH2- C- and a third RRMU that has the structure wherein R3 is H, or an alkyl or alkenyl of Ci, C2, C3, C4, s, Ce, C? , Ce, Cg, Cio, u, C? 2, C13, C14, C15, Ci6 / Cp, 5 Cis, or Cig; and m is 1 or 2; where at least 50% of the RRMÜ have the structure of the first RRMU; and wherein the third RRMUs are not the same as the first monomeric random repeat unit or the second monomeric random repeat unit.

Synthesis of Biodegradable PHAs The biodegradable PHAs of the present invention can be synthesized by synthetic methods with chemical or biological basis. A chemical approach involves ring-opening polymerization of the β-lactone monomers as will be described below. The catalysts or initiators used may be a variety of materials such as, for example, aluminoxanes, dis tanoxanes, or alkoxy-zinc and alkoxy-aluminum compounds (see Agostini, D.E., J.B. Lando, and J.R. Shelton, J. POLYM.

SCI. PART A-1, Vol. 9, pp. 2775-2787 (1971); Gross, R.A., Y. Zhang, G. Konrad, and R.. Lenz, MACROMOLECULES, Vol. 21, pp. 2657-2668 (1988); and Dubois, P., I. Barakat, R. Jéróme, and P. Teyssié, MACROMOLECULES, Vol. 26, pp. 4407-4412 (1993); Le Bogne, A. and N. Spassky, POLYMER, Vol. 30, pp. 2312-2319 (1989); Tanahashi, N., and Y. Doi, MACROMOLECULES, Vol. 24, pp. 5732-5733 (1991); Hori, Y., M. Suzuki, Y. Takahashi, A. Ymaguchi, and T. Meshishita, MACROMOLECULES ,. Vol. 26, p. 4388-4390 (1993); and Kemnitzer, J.E., S.P. McCarthy, and R.A. Gross, MACROMOLECULES, Vol. 26, pp. 1221-1229 (1993)). The production of isotactic polymer can be carried out by the polymerization of an enantiomerically pure monomer and an initiator without racemization, either with retention or inversion of the stereocenter configuration or by polymerization of the racemic monomer with an initiator that preferably polymerizes a enantiomer. ' For example: - CH3 PHBMVsopoiu random The PHA derived naturally from the present invention are isotactic and have the absolR configuration in the stereo molecules in the polymer structure. Alternatively, isotactic polymers can be produced where the configuration of the stereocenters is predominantly S. Both isotactic materials will have the same physical properties and most of the same chemical reactivities except when a reactive is implied is specific, such as for example an enzyme Atactic polymers, polymers with random incorporation of stereocenters R and S, can be produced from racemic monomers and initiators or polymerization catalysts that show no preference for any enantiomer while these initiators or catalysts often polymerize the monomers of high optical purity for isotactic polymer (eg, "." distanoxane catalysts) (see Hori, Y., M. Suzuki, Y. Takahashi, A. Yamaguchi, T, Neshishita, MACROMOLECULES, Vol. 26, pp. 5533-5534 ( 1993).) Alternatively, the isotactic polymer can be produced from racemic monomers if the polymerization catalyst has an improved reactivity for one enantiomer with respect to the other.

'Depending on the degree of preference, stereo-ho R or S opolomers, stereo-block copolymers separately or a mixture of stereo-block copolymers and stereo-homopolymers can be produced. (see Le Borgne, A, and N. Spassky, N., POLYMER, Vol. 30, pp. 2312-2319 (1989); Tanahashi, N., and Y.

Doi, MACROMOLECULES, Vol. 24, pp. 5732-5733 (1991); Y Benvenuti, M. and R.W. Lenz, J. POLYM. SCI .: PART A: POLYM. CHEM., Vol. 29, pp, 793-805. (1991)). Some initiators or catalysts. They are known to produce predominantly syndiotactic polymers, polymers with stereo-repeat repeating units * R and S alternating, precursors of racemic monomers (see Kemnitzer, JE, SP McCarthy and RA Gross, MACROMOLECULES, Vol. 2G, p.1221-1229 (1993)) while some initiators or catalysts can produce all three types of stereopolymers (see Hocking, PJ and RH Marchessault, POLYM BULL., Vol. 30, pp. 163-170 (1993)). For example, the preparation of copolymers of poly (3-hydroxybutyrate-co-3-tiderox-alkanoate) the comonomer of 3-hydroxyalkanoate is a 3-alkyl-β-propiolactone wherein the alkyl group contains at least three (3) carbons in length, it is carried out in the following way. Adequate precautions are taken to exclude air and moisture. The lactone monomers (purified, dried, and stored under an inert atmosphere), the β-butyrolactone and a 3-alkyl-β-propiolactone in the desired molar ratio are loaded by syringe or cannula into a glass tube or flask with borosilicate, oven-dried, purged with argon and flamed, covered with a rubber packing. The polymerization catalyst is added as a toluene solution via a syringe. The tube is shaken in circles carefully to mix the reagents (but without making contact with the rubber packing) and then heated in an oil bath at the desired temperature for the prescribed time. As the reaction proceeds, the mixture becomes viscous and can solidify. If an isotactic polymer is produced, the solid polymer precipitates until the total mass solidifies. The product can then be cooled, removed from the tube and freed from the residual monomer by vacuum drying. Alternatively, the product can be dissolved in a suitable solvent (eg, chloroform) and recovered by precipitation in a non-solvent (eg, ether-hexane mixture, 3: 1 v / v), and dried at empty. The molecular weight is determined by standard methods such as eg size exclusion chromatography (SEC, also known as gel permeation chromatography or GPC). The comonomer content of the polymers is determined by nuclear magnetic resonance (NMR). In a preferred method for synthesizing the PKA- of the present invention, the initiator is an alkyl-zinc alkoxide, as set forth in - United States Patent No. 5,648,452 entitled "Polymerization of Beta-S bituted-Beta-Propiolactones Initiated by Alkylzinc Alkoxides", L.A. Schechtman and J.J. Kemper, assigned to The Procter and Gamble Company, issued July 13, 1997. These initiators have the general formula R1ZnOR2, wherein R1 and R2 are independently a C'i-Cio alkyl. In a preferred method of synthesis, the initiator is selected from the group consisting of ethyl isopropoxide-zinc, methyl-zinc isopropoxide, ethyl-zinc ethoxide, or ethyl-zinc methoxide-most preferably isopropoised ethyl-zinc. Other cpolymers useful in the present invention can be produced by replacing the starting materials (monomers) in the above process with the 3-alkyl-β-lactones corresponding to the desired monomer units in the final copolymer product. Alternatively, the biological synthesis of the biodegradable PHAs useful in the present invention can be carried out by fermentation with the appropriate organism (natural or engineered) with the reservation of ali. It was adequate (simple c of multiple components). The biological synthesis can also be - - carrying out botanical species engineered to express the copolymers of interest (see World Patent Application No. 93-02187, Somerville, Poirier and Dennis, published on February 4, 1993; and the Patent of the States -United No. 5,650,555, Dennis et al., Granted on 22 - July 1997, and the United States Patent No. 5,610,041, Nawrath et al., Issued on 11 March 20,. 1997; and Poole, R., SCIENCE, Vol. 245, pp. 1187-1189 (1989)).

CRYSTALLINITY The percentage by volume of crystallinity (Fc) of a semi-crystalline polymer (or copolymer) often determines what kind of end-use properties the polymer possesses. For example, highly crystalline polyethylene polymers (greater than 50%) are tough and rigid, and suitable for products such as, for example, plastic milk containers. On the other hand, the low crystalline polyethylene is flexible and strong, and is suitable for products such as, for example, food wraps and. trash bags. The crystallinity can be determined in several ways, including x-ray diffraction, differential scanning calorimetry (DSC), density measurements and infrared absorption. The most appropriate method depends on the material that will be tested. X-ray diffraction is the most appropriate when little is known about the thermal properties of the material and structural changes can occur in the crystal. The basic principle rests on the fact that the amorphous parts of the material disperse the x-rays in a diffuse or wide range of angles, while the crystals diffract the x-rays at sharp angles, defined precisely. However, the dispersed intensity is constant. This allows the calculation of the amount of crystalline material in a sample if the amorphous and crystalline diffracted intensities can be separated. A very precise method has been developed by Ruland, which can detect differences in the percentage of crystallinity as small as 2% (see Vonk, C, FJ Ralta-Calleja, X-RAY SCATTERING FROM SYNTHETIC POLYM ™ RS, Elsevier: Amsterdam, (1989) and Alexander, L., X-RAY DIFRACT-ION METHODS IN POLYMER SCIENCE, Robert Kreiger Pub. Co., New York, (1979)). At the time of fusion, the crystals require a fixed amount of heat at the melting temperature that transforms from crystalline matter to molten material. This heat of fusion can be measured by several techniques, the most popular being DSC. If the heat of fusion of a 100% crystalline material is known, and there is no significant annealing, or the melting / recrystallization phenomenon occurs at the time of heating to melting, then the DSC can very accurately determine the fraction on weight of crystallinity (see THERMAL CHARACTERI ZAT10N OF POLYMER MATERIALS, E. Turi, Ed., Academic Press, New York, (1980), and Wunderlich, B., MACROMOLECULAR PHYSICS, Academic Press, New York, (1980)).

If the densities of pure Crystalline material and pure amorphous material are known, then density measurements of a material can provide the degree of crystallinity. This simulates the additivity of specific volumes, but this requirement is met for polymers (or copolymers) of homogeneous structure. This method depends on the careful preparation of. the sample in such a way that there are no bubbles or large gaps in If purely crystalline and amorphous absorption bands can be identified, then the infrared absorption spectrum offers a convenient way to determine crystallinity, (see Tadokoro, H., STRUCTURE OF CRYSTALLINE POLYMERS, John Wiley &Sons, New York, ( 1979)) .- It should be noted that different techniques will often give rise to slightly different values of Fc, because they are based on different physical principles. For example, density measurements often provide values greater than the x-ray diffraction. This is due to the continuous change in density at the interface between the crystalline and amorphous polymer material (or copolymer). While x-ray diffraction does not detect this matter as crystalline, density measurements will be affected by this interface region. In general, the PHAs of the present invention preferably have a crystallinity of between about 0.1% and 99%, as measured by x-ray diffraction; more preferably between about 2% and 80%; more preferably still between about 20% and 70%. . When a PHA of the present invention will be processed in a film; The amount of crystallinity in 'this PHA' is. more preferably between 2% and 65%, as measured by x-ray diffraction; more preferably between about 5% and 50%, still more preferably between about 20% and 40%. When a PHA of the present invention will be processed in a ho-ja, the amount of crystallinity in it. PHA is most preferably between-about 0.1% and 50%, as measured by x-ray diffraction; of better preference between between 5% and 50%; most preferably between about 20% and 40%.

When a PHA of the present invention will be processed into a normal fiber or a non-woven fabric, the amount of crystallinity in this PHA is more preferably between about 60% and 99%, as measured by x-ray diffraction; more preferably between about 70% and 99%; more preferably between about 80% and 99%. When a PHA of the present invention will be processed into a soft elastic fiber, the amount of crystallinity in this PHA is more preferably between about 30% and 80% as measured by x-ray diffraction; more preferably between about 40% and 80%; more preferably still between about 50% and 80%. When a PHA of the present invention will be processed in a molded article, the amount of crystallinity in this PHA is more preferably between about 10% and 80%, as measured by x-ray diffraction; a greater preference of between about 20% and 70%; more preferably still between about 30% and 60%.

When a PHA of the present invention will be processed in an elastomer or adhesive, the amount of crystallinity in this PHA is more preferably less than about 50%, as measured by x-ray diffraction; of greater preference less than about 30%; more preferably less than about 20%.

FUSION TEMPERATURE Preferably, the biodegradable PHAs of the present invention have a melt temperature (Tm) of between about 30 ° C and 160 ° C, more preferably between about 60 ° C and 140 ° C, more preferably still between approximately 90 ° C and 120 ° C.

PLASTIC ARTICLES COMPRISING PHA The PHAs of the present invention can be processed into a variety of plastic articles, among which include: • films, sheets, fibers, foams, molded articles, non-woven fabrics, elastomers, and adhesives.

A. Films In one embodiment of the present invention, the plastic article is a film. In the sense in which it is used herein, "film" means an extremely thin continuous piece of a substance having a high ratio of length to thickness and a high ratio of width to thickness. Insofar as there is no requirement for a precise upper limit or thickness, a preferred upper limit could be 0.254 mm, more preferably even approximately 0.01 mm, more preferably still approximately 0.005 mm. The protective value of any film depends on it being continuous, that is, without holes or cracks, as it must be an effective barrier for molecules. such as atmospheric water vapor and oxygen. The film of the present invention can be used in a variety of disposable products including, but are not limited to: disposable diapers, shrink wrappers (e.g., food wraps, wraps for consumer products, pallet wraps and / or cages and the like), or bags (bags for grocery stores, bags to store food, bags for sandwiches, resealable Ziploc® bags, trash bags and the like). In a preferred embodiment of the present invention, the film of the present invention is impermeable to liquids and suitable for use in disposable, absorbent sanitary inner garments, such as, for example, disposable diapers, feminine hygiene products and the like. More preferably, the films of the present invention, in addition to the increased biodegradability and / or capacity to form fertilizer, have the following properties: a) a machine direction tension modulus (MD) of between about 10,000 and 100,000 pounds / square inches (6,895 x 108 dynes / square centimeters to 6,895 x 109 dynes / square meters), b) tear strength in MD of at least 70 grams per 25.4 μm thickness, c) tear resistance in the cross machine direction (CD) of at least 70 grams per 25.4 μm thickness, d) an impact strength of at least 12 cm as measured by falling ball drop, e) lower moisture transport speed at approximately 0.0012 grams per square centimeter for 16 hours, f) a module at 60 ° C of at least 5.52 x 107 dynes / centimeter, square inches (800 pounds / square inches), and g) a thickness of between approximately 12 μm and 75 μm. The methods for testing these performance criteria are discussed in more detail later. Prior to the Applicant's invention, the polyhydroxyalkanoates studied for use in the production of commercial plastics presented significant impediments to their use in plastics. As discussed above, polyhydroxyalkanoates such as PHB and the codend! PHBV number are difficult to process due to their thermal instability. In addition, these polyhydroxyalkanoates are especially difficult to process in films due to their low crystallization rate. The Applicants have found that the PHA copolymers of the present invention, which comprise a second RRMU as defined above, have a branched alkyl of three (3) carbons, surprisingly they are easier to process into films, especially as compared to the PHB or the PHBV. The Applicants discovered in a surprising manner that these random, linear copolymers with a limited number of branched alkyl chains, of average size, containing three (3) carbons, provide, in addition to the biodegradability, the following properties, in particular as compared to the PHB or the PHBV: a) a lower melting temperature, b) a lower degree of crystallinity, and c) an improved melting rheology. This is especially surprising in light of the fact that the straight, longer, branched branched chain of the medium-sized branched alkyl contains only two (2) carbons. Without being limited by theory, the Applicants believe that features a) and b) are achieved by excluding the second RRMU from the crystal lattice of the first RRMU, resulting in a decreased temperature for thermal processing and improved stiffness and elongation properties. Again, without being limited by theory, the Applicants believe that feature c) is achieved by the increased entanglement between the copolymer chains due to the side chains of the second RRMU. This increased entanglement may occur because of the increased hydrodynamic volume of the cope-lime (for example, the second omerfca unit creates defects in the helical structure), the "hooking" or "capture" of the side chains on different copolymer structures while in fusion, or decreased chain cleavage due to the lower Tm (ie, the enlarged thermal process window). 1. Performance criteria and test methods for films For a film to perform satisfactorily as a reinforcement sheet for disposable diaper, with the ability to form compost, it must be made from resins or structures that are biodegradable and must demonstrate the following properties of high strength, a suitable barrier for fluids, a suitable modulus or flexibility and a high melting point. The reinforcement sheets of the disposable diapers must have sufficient resistance to both the process in a high speed disposable diaper conversion machine and to provide a "moisture proof" barrier in the use of an infant or toddler. The humidity test should be good enough for the clothes or bedding, already. Whether it's the baby's infant c, do not j * moisten or get dirty. It must have a module or flexibility that is, at the same time, very low to be a nice and soft material to be used as the outer cover of a diaper for small children and still high enough to be easily handled over the converters from the disposable diaper to high speed without wrinkling, bending, or folding. It must have sufficient heat resistance so that it will not permanently deform, melt, or lose strength under typical heat storage conditions or lose its integrity in the high speed disposable diaper converters that typically use heat-melted adhesives to join the components of a disposable diaper. Films that are sufficiently resistant to be suitable as biodegradable reinforcing liners and / or capable of composting for disposable diapers preferably demonstrate two properties: (a) breaking strength of a falling weight 'and (b) resistance to tear both in the direction of the manufacturing machine and in the direction transverse to the manufacturing machine. The preferred reinforcing liners of the present invention can resist the fall of a spherical steel ball of approximately 19 millimeters in diameter and 27.6 to 28.6 grams of mass from a height of 12 centimeters in such a way that at least 50% of the tests do not result in a break of any size (deformation is acceptable). Preferred materials are those that exhibit 50% or less of faults from a height of more than 20 centimeters. Similarly, the acceptable reinforcement liners of the present invention demonstrate an average break propagation strength of 70 grams per 25.4 microns thickness of the material both in the machine direction and in the cross direction to the manufacturing machine when employs a standard Elmendorf pendulum test device, such as the Elmendorf Model No. 60-100, against 16 sheets of material that have been prepared with a cut or nick in accordance with the TAPPI Method T 414om-88. Those reinforcing canvases that show resistance to tear propagation of 200 or more grams per 25.4 microns of thickness in the transverse direction to the machine are preferred, since these are particularly good to avoid a tendency to fail in the use at the break. 43 It has also been found that barrier films sufficient to carry moisture are those that allow the passage of less than 0.0012 grams of synthetic urine on an absorbent paper towel per square centimeter of area per 25.4 microns of thickness during each 16 hours of time. when the test film is placed between the absorbent paper towel and a diaper core containing typical absorbent gelling material and a pressure simulating that of a baby. The specific conditions of the test are those in which the core area is greater than that of the test material, the core is loaded with synthetic urine at its theoretical capacity and placed under a weight of approximately 35 g / cm2 (0.5 psi). It has also been found that materials of sufficient heat resistance demonstrate a Vicat softening point of at least 45 ° C. Vicat softening is tested using a Heat Distortion Apparatus Model No. CS-107 or equivalent and an ASTM modification of D-1525. The modification is in the preparation of the sample. A film with a size of 19 square millimeters from 4.5 to 6.5 mm in thickness is prepared for Vicat needle penetration tests by melting the material that will be tested in a mold using a temperature of 120 ° C and a pressure of 7.031 x 105 g / cm2 (10, 000 psi) (using a Carver press or similar) for two minutes after a warm-up period of at least 2 minutes. The Vicat softening point is the temperature at which a flat-tipped needle of circular cross-section of 1 mm square will penetrate the sample to a depth of 0.1 cm under a load of 1000 g using a uniform temperature rise rate of 50 ° C per hour. It has also been found that materials of sufficient modulus in the machine direction demonstrate a module of the 1% superior secant type in at least about 6.895 x 108 dynes / cm2 (10,000 psi) and below approximately 6,895 x 109 dynes / cm2 (100,000 psi). The test is performed on a machine to test electronic tension such as, for example, the Instron Model 4201. A strip of material with 2.54 cm wide, preferably 0.00254 cm thick, is cut to a length of approximately 30 cm with the longest dimension parallel to the machine direction of the material. The test strip is clamped in the clamps of the tension tester in such a way that the actual caliber or length of the tested material is 25.4 cm. The jaws are separated at low speed in the range of 2.54 cm per minute to 25.4 cm per minute and a stress strain curve is plotted in a diagram within a device for attachment. The secant modulus at 1% is determined by reading the tension or load of the diagram at the elongation stress point at 1%. For example, the 1% stress point is achieved when the distance between the jaws has increased by 0.254 cm. When the jaws are separated at the speed of 2.54 cm per minute and the recording device is running at a speed of 25.4 cm per minute, the 1% stress point will be located at a distance of 2.54 cm from the starting point. The response to stress is divided by the thickness of the sample material if it is not 0.00254 cm thick. Particularly mild, and therefore preferred, materials exhibit 1% drying moduli in the range of 6.895 x 108 to 2.068 x 109 dynes / cm2 (10,000 to 30,000 psi). Since absorbent articles can experience temperatures as high as • 140 ° F (60 ° C) during storage in warehouses or boarding in trucks or rail cars, it is important that the film of the reinforcement canvas and - " • Other components maintain their integrity at these temperatures.Although it is expected that the modulus of the films will decrease somewhat between 20 ° C and 60 ° C, the module should not decrease so much as to allow the film to deform in the package before reaching For example, a polyethylene reinforcement sheet with a temperature module of approximately 4 x 109 dynes / cm2 (58,000 psi) may have a module at 60 ° C of 1.2 x 109 dynes / cm2 (18,560 psi) which is acceptable A softer polyethylene reinforcement sheet with an ambient temperature modulus of approximately 8.0 x IO8 dynes / cm2 (11,600 psi) may have a module at 60 ° C of approximately 3.5 x 108 dynes / cm? (5,076 psi) ) that is even a In general, an acceptable reinforcing canvas film of the present invention will have a modulus at 60 ° C of at least 5.52 x 107 dynes / cm2 (800 psi). The module's dependence on temperature, also referred to as the module / temperature spectrum, is best measured in a dynamic mechanical analyzer (DMA), such as, for example, a Perkin Elmer 7 Series / Unix Thermomechanical Analyzer TMA 7 equipped with a software package 7 Series / Unix DMA 7 Temperature / Time, 'hereinafter referred to as the DMA 7, available from Perkin-Elmer Corporation of Nowalk, Connecticut. There are many other types of DMA devices, and the use of dynamic mechanical analysis to study the modulus / temperature polymers spectrum is well known to those skilled in the art of characterizing polymers (or copolymers). This information is well summarized in two books, the first being DYNAMIC MECHANICAL ANALYSIS OF POLYMERIC MATERIALS, MATERIALS SCIENCE MONOGRAFS VOLUME 1 by T. Murayama (Elsevier Publishing Co., 3978) and the second being MECHANICAL PROPERTIES OF POLYMERS AND COMPOSITES, VOLUME 1 of LE Nielsen (Marcel Dekker, 1974). The operating mechanism and procedures for using the DMA 7 can be found in the Perkin-Elmer User Manuals 0993-8677 and 0993-8679, both dated May 1991. For those experts in the use of the DMA 7, the following run conditions must be sufficient to replicate the module data at 60 ° C presented hereinafter.

To measure the modulus / temperature spectrum of a film sample, the DMA 7 is set to run in a temperature sweep mode and is equipped with an extension measurement system (EMS). A film sample approximately 3 mm wide, 0.0254 mm thick and of sufficient length to allow 6 to 8 mm length between the jaws of the sample to be mounted on the EMS. The device is then enclosed in an environmental chamber continuously swept with helium gas. Tension is applied to the film in the longitudinal direction to achieve a deformation or strain of -0.1 percent of the original length. A dynamic sinusoidal stress is applied to the sample at a frequency of 5 cycles per second. In the t-emperature scan mode, the temperature increases at a rate of 3.0 sC / minute from 25 ° C to the point where the sample melts or breaks, while the frequency and voltage remain constant. The temperature-dependent behavior is characterized by changes in the monitoring of the effort and the phase difference in time between stress and stress. The storage module values in Pascais are calculated by the computer together 49 with other data and they are shown as temperature functions in a finish! with video screen. Normally, the data is stored on a computer disk and a printed copy of the module / storage temperature spectrum is taken for further review. The 60 ° C module is determined directly from the spectrum. 2. METHOD FOR FILM MAKING The films of the present invention used as reinforcing liners having an increased biodegradability and / or ability to form compost can be processed using conventional methods to produce single layer or multilayer films in manufacturing equipment. of conventional film. The granules of the PHAs of the present invention can first be mixed dry and then molten in a film extruder. Alternatively, if insufficient mixing is present in the film extruder, the granules can be mixed first dry and then melts mixed in a combined extrusion previously followed by a new granulation formation prior to extrusion of the film.

The PHAs of the present invention can be processed into films using film extrusion methods either melt or blown, both described in PLASTICS EXTRUSION 5 TECHNOLOGY - 2nd Ed., By Alian A. Griff (Van Nostrand Reinhold - 1976). The molten film is extruded through a linear slot die. In general, the flat web is cooled on a polished metal roller with great movement. It cools quickly and is removed from this roller, passes over one or more auxiliary chill rollers, then through a set of rollers for extraction or - • • transport '' covered with rubber and finally to a wire feeder. A method to make a film of cast reinforcement sheet for the absorbent articles of the present invention is described in an example below. In extrusion of film by blowing, the melt is extruded upwards through a thin annular die opening. This process is also referred to as an extrusion of tubular film. The air is introduced through the center of the matrix, to inflate the tube and thereby cause it to expand. Then a bubble forms in movement that remains at a constant size ** > by controlling the "" internal air pressure. The tube of the film is cooled with air, blown through one or more cooling rings surrounding the tube. The tube is then collapsed by dragging it into a flattening frame through a pair of extraction rollers and in a winder. For reinforcing canvas applications, the flattened tubular film opens in subsequent cut, it is unfolded and further cut into widths suitable for use in the products. Both cast film and blow film processes can be used to produce film structures either monolayer or ultilapa. For the production of monolayer films from a single thermoplastic material or a mixture of thermoplastic components, only a single extruder and a single distributor matrix are required. For the production of the multilayer films of the present invention, coextrusion processes are preferably used. These processes require more than one extruder and one matrix system, either a coextrusion or multiple distribution feed block, or a combination of the two to achieve the multilayer film structure. U.S. Patents 4,152,387 and 4,197,069 disclose the principle of coextrusion augmentation block. The multiple extruders are connected to the feed block which uses movable flow dividers to proportionally change the geometry of each individual flow channel in direct relation to the volume of the polymer passing through the flow channels. they design in such a way that at their 'point of confluence, the materials flow together at the same velocity of flow and pressure - eliminating interfacial tension and flow instabilities. Once the materials are joined in a feed block, they flow in an individual distribution matrix as a composite structure. It is important in these processes that the melting viscosities and melting temperatures of the materials do not differ "too; otherwise the instabilities of 'flow can result in the conduction of the matrix for poor control of the thickness distribution of the layer in the multilayer film. 53 An alternative for feed block coextrusion is "a multiple or cross-linked matrix as set forth in U.S. Patents 4,152,387, 4,197,069, and in U.S. Patent 4,533,308 mentioned above. While in the feedblock system, the melted currents are conducted together outward and before entering the matrix body, in a multiple distribution or blade matrix, each molten current has its own distribution in the 'matrix, where the polymers spread independently in their respective distributions. • The melt streams are matched near the die gap with each melt current in the total width of the die. The movable blades provide an adjustment capacity in 'the output of each flow channel in direct proportion' to the volume of material flowing through it. same, allowing the melts to flow together at the same desired linear flow rate, pressure and width. Since the melt flow properties and melting temperatures of the processed materials can vary widely, the use of a blade die has several advantages. The matrix can be lent to thermal clg characteristics, where materials of melting temperatures that differ greatly, for example up to 175 ° F (80 ° C), can be processed together. • Each distribution in a blade matrix can be designed and made for a specific polymer (or copolymer). In this way, the flow of each polymer is influenced only by the design of its distribution and not by the forces imposed by other polymers. This allows materials with melting viscosities that differ greatly to be coextruded into multilayer films. In addition, the blade matrix also provides the ability to tailor the width of the individual distributions, such that an inner layer, for example a biodegradable water-soluble polymer similar to Vinex 2034, can be completely surrounded by water-insoluble materials. without leaving exposed edges susceptible to water. The patents mentioned above also expose the combined use of power block systems and blade matrices to achieve more complex multilayer structures. The multilayer films of the present invention can comprise two or more layers. In general, three-layer and five-layer balanced or symmetrical films are preferred. The multilayer balanced three layer films comprise a core core layer and two identical outer layers, wherein the core core layer is placed between the two outer layers. The five-layered balanced multilayer films comprise a core core layer, two identical tie layers and two identical outer layers, wherein the core core layer is placed between the two tie layers and a tie layer is placed between the core core layer and each outer layer. Balanced films, although not essential for the films of the invention, are less prone to coiling or twisting than unbalanced multilayer films. In three-layer films, the core core layer comprises 30 to 80 percent of the total film thickness and each outer layer comprises 10 to 35 percent of the total film thickness. The tie layers, when used, each comprise between about 5 percent and 10 percent * of the total thickness of the films. - - * < -. 3 & & amp; 56 B. Holes In another embodiment of the present invention, the plastic article is a sheet. In the sense in which it is used herein, "sheet" means a very thin continuous piece of a substance, which has a high ratio of length to thickness and a high ratio of width to thickness, where the material is thicker than 0.254 mm. Sheet formation - share many of the same characteristics as. the film in terms of properties and manufacturing, except that the formation of leaves is more rigid and has a self-supporting nature. These differences in rigidity and support d n result in some modification of manufacturing methods. 1. Manufacturing methods The sheets, due to the thickness and consequent stiffness, can not be blown like a film. However, many other of the same processes used to manufacture films can be modified to carry out sheet formation. An example is the melt extrusion described above. In addition to extrusion, sheet formation is also carried out by winding and calendering. to . Winding Winding produces a film with an orientation predominantly in the machine direction by accelerating the film from a point nip or point of contact where the thickness is reduced (ENCYCLOPEDIA OF POLYMER SCIENCE AND ENGINEERING. 'Vol. 8, pp. 88-106, John Wiley and Sons, New York, (1986), hereinafter referred to as "EPSE-1"). Large forces are found at the nip point, although the total orientation can be increased with respect to other forms of orientation in the machine direction. b. Calendering, To produce a non-oriented film or sheet with high performance, calendering is used (G. W. Eghmy, Jr. in MODERN PLASTYCS, J.

Agrandoffr ed. Encyclopedia, Vo? 59 (10A), pp. 220-222 (1982) and R. A. Elden and A. "D." Swan, CALENDERING OF PLASTICS, American Elsevier 'Co., Inc., New Yorí, (1971)). The calendering process employs sets of specially hardened drive rolls, supported in such a way that they can bend or twist in position relative to each other during operation. This is to control the thickness in the calendered material. The calenders are usually made up of four rollers that form three nip points. These nip points are the nip feed, measurement and finishing points. The nip point fed is where the polymer is supplied, mixed and heated. The nip point of measurement reduces the thickness of the sheet to the approximate final thickness. The determined nip adjusts the gauge of the blade by varying the position of the third or middle roller, (see EPSE-2).

C. Fibers In another embodiment of the present invention, the plastic article is a fiber. In the sense in which it is used herein, "fiber" refers to a macroscopically homogeneous and flexible body, which has a high ratio of length to width and a small cross section. A general summary of fibers can be found in the ENCYCLOPEDIA OF POLYMER SCIENCE AND ENGINEERING, Vol. 6, p. 647-755 and pp. 802-839, John Wiley and Sons, New York, (1986) (hereinafter referred to as "EPSE ~ 2 ') The fibers of the present invention are useful as textiles in threads for undergarments. The present invention is also useful for manufacturing lightweight fibrous materials useful in agricultural applications to protect, stimulate or control vegetable cultivation, as well as in greenhouse thermal screens, furrow covers, turf decks, barriers and hydroponics. The key properties are light, air and moisture permeability.An important aspect is the cost effectiveness when considering the terms of weight, strength and dimensional stability.An elastomeric fiber is a fiber consisting of polymers (or copolymers) with a main glass transition temperature well below room temperature (see EPSE-2) This criterion excludes some fibr with elastic properties, such as, for example, hard fibers, corrugated, but allows the inclusion of fibers of multiple constituents where one of the constituents is an elastomer. All the elastomeric fibers are characterized by a greater elongation in the lower, breaking module, and a 6 recovery greater than a large deformation than normal fibers. 1. Methods for manufacturing the fiber The fibers of the present invention can be processed using a variety of conventional techniques well known in the art, including but not limited to: melt spinning, dry spinning and wet spinning. Often combinations of these three basic processes are used. In yarn by f >When used, a PHA of the present invention is heated above its melting point and the molten PHA is passed through a spinner. A spinner is a matrix with many small holes that vary in number, shape and diameter (see EPSE-2). The molten PHA jet is passed through a cooling zone where the PHA solidifies and then transfers towards a team of post-rounds t and absorption. In the dry spinning, with PHA of the present invention it is dissolved and the PHA solution is extruded under pressure through a spinner (see EPSE-.2). The jet of the PHA solution is passed through a heating zone where the solvent evaporates and the filament solidifies. In wet spinning, a PHA of the present invention also dissolves and the solution is passed through a spinner which is immersed in a coagulation bath (see ESPE-2). As the PHA solution emerges from the orifices of the spinner within the coagulation bath, the PHA can be precipitated or chemically regenerated. Normally, all these processes need an additional stretch so that useful properties can be obtained, for example to serve as textile fibers. "Stretched" refers to the stretching and attenuation of the fibers to achieve an irreversible extension, induce a molecular orientation and develop a fine fiber structure (see ESPE-2). This fine structure is characterized by a high degree of crystallinity and by the orientation of both the crystallites and the amorphous PHA chain segments.

D. Foams In another embodiment of the present invention, the plastic article is a flexible foam. As used herein, "foam" refers to the PHA of the present invention whose apparent density has been substantially decreased by the presence of many cells distributed throughout its volume (see ASTM D 883- 62T, American Society for Testing and Materials, Philadelphia, Pa., (1962)). These "two phase" gas / solid systems in which the solid is continuous and composed of a synthetic polymer or rubber include cellular polymers (or copolymers), expanded plastics and foamed plastics (ENC YCLOPEDIA OF CHEMICAL TECHNOLOGY, Vol. 11, John Wiley &Sons, New York (1980), hereinafter referred to as "ECT"). The gaseous phase is distributed in bags or empty spaces called cells that are classified into two types, open and closed. The open cell materials are foams whose SB cells interconnect in such a way that the gases can pass freely through the coats. Closed cell materials have cells that are discrete and isolated from each other. The foams are further categorized into flexible and rigid foams. This classification is based on a particular ASTM test procedure (see ASTM D, Vol. 37, pp. 1566-1578, American Society of Testing and Materials, Fiiadelfia, Pa., (1978)). A flexible foam is a foam that does not break when a 20 x 2.5 x 2.5 cm piece is wrapped around a 2.5 cm mandrel at a uniform speed of 1 lap / 5s at 15-25 ° C. Foams that do not break under this test are called rigid foams. The foams find many applications such as packaging, comfortable cushioning, insulation and structural components. In some packaging areas, a foamed material having increased biodegradability and / or ability to form fertilizer could offer benefits superior to those currently used as packaging such as for example , polystyrene, paper and starch foams. In containers for hot foods, polystyrene offers significantly higher thermal insulation compared to the only paper wrappers, currently degradable alternatives. Foamed articles comprising a PHA of the present invention have the thermal insulation properties of polystyrene, are even biodegradable and / or have the ability to form compost. These materials are ideal for hot prepared foods and cold food packaging.

The pieces of foamed polystyrene are used as cushioning materials for consumer and industrial articles Many of these pieces end up in landfills The foamed pieces comprising a PHA of the present invention perform well as polystyrene and have a biodegradability and / or ability to form increased fertilizer Other packaging materials that can form different fertilizer such as starch, these pieces of PHA are resistant to very common solvents and liquids, including water. i. Methods for making foam The foams of the present invention can be processed using conventional procedures well known to those skilled in the art. A predominant method for foam production involves expanding a fluid polymer (or copolymer) phase to a low density cellular phase and then preserving this state (see ECT). Other processes include leaching materials that have previously been dispersed in the polymer or copolymer), agglomerating small particles and dispersing cellular particles in a polymer (or co-polymer). These steps constitute the expansion process. There is cellular initiation, cell growth and cell stabilization. Many methods are used-to create, make cells grow and stabilize. The expandable formulations depend on the increase in pressure inside the cells initiated in relation to the surrounding ones. The cells are stabilized either by chemical (for example cross-linking, polymerization) or physical (crystallization, vitreous fusion transition). Polystyrene is an example of a polymer that is foamed by this type of process. A blowing agent such as, for example, isomeric pentanes and hexanes or halocarbons (H, R. Lasman, MODERN PLASTICS, Vol. 42 (1A), p.314 (1964)) is mixed with the polymer (or copolymer) either by heating and leaving the blowing agent to penetrate the polymer (U.S. Patent 2 ^ 681,321, issued June 15, 1954, F, Staatny and R. Gaeth, assigned to BASF), or by polymerizing the polystyrene in presence of the spreading agent (U.S. Patent 2,983,692, issued May 9, 1961, G. F. D'Alelio, assigned r, Koppers Co.). The manufacture of articles is usually carried out in multiple steps, the first of which uses steam, hot water or hot air to expand the polymer in preformed beds of low density. These preformed beds are allowed to age, sometimes in multiple steps to correct the size of the cell and then packaged into molds and fused together by heat and additional expansion (SJ Skinner, S. Baxter, and PJ Gray, Trans. J PLAST.Int.Volume 32, page 180 (1964)). The stabilization is carried out by cooling the polymer to temperatures below its glass transition temperature. The decompression expansion processes create and develop cells by decreasing the external pressure during processing. Cellular polypropylene and polypropylene are often produced in this way. A blowing agent for decomposition is premixed with the polymer (or copolymer) and fed through an extruder under elevated temperature and pressure so that the blowing agent is partially decomposed. When the material exits the extruder, it enters a lower pressure zone. The simultaneous expansion and cooling are carried out, resulting in a stable cellular structure due to the rapid crystallization of the polymer (R. H. Hansen, 61).

SPE J., .Vol. 18, p 77 (1962), W. T. Higgins, MOD. PLAST., Vol. 31 (7), p. 99, (1954)). The dispersion processes produce foams by directly dispersing the solid or gas in the polymer phase (or copolymers) and then, when necessary, stabilizing the mixture (ECT). In this foaming process, a gas is mechanically dispersed in the polymer or monomeric phase, producing a foam of temporary stability. This foam. then it is chemically stabilized by crosslinking or polymerization. - Latex foam rubber is manufactured in this way (see ECT).

E. Molded articles Eri another embodiment of the present invention, the plastic article is a molded article. As used herein, "molded article" means objects that are formed from polymer or copolymer materials (eg, FA) that are injected, compressed or blown by means of a gas in the form defined by a female mold. These objects can be solid objects similar to toys, or hollows similar to bottles and containers.

, * - The molding of thermoplastics by injection is a multi-step process by which a PHA of the present invention is heated until it is melted, then it is put into a closed mold where it takes the form and finally solidifies upon cooling . There are a variety of machines that .used in injection molding. Three common types are beating devices, screw plasticizer with injection and reciprocating screw (see ENCYCLOPEDIA OF POLYMER SCIENCE AND NGINEERING, Vol. 8, pp. 102-138, John Wiley and Sons, Nevv-York, (1986); hereinafter referred to as "EPSE-3"). A blow molding machine consists of a cylinder, a propagator and a plunger. The plunger pushes molten ai into the mold. A plasticador by screw cor-a second injection by stages consists of a plasticador, a directional valve, a cylinder without a propagator, and a device for golpeo. After plastication by the screw, the striking device pushes the melt into the mold. A machine for reciprocating screw injection consists of a barrel and a screw. The screw rotates to melt 'and mix the material and ... sf 4,.; i. * «< * -. «* > *! íf ''. . then it moves forward to push the melt into the mold. The 'compression molding in thermoplastics consists in changing an amount of a PHA of the present invention in the lower half of an open matrix. The upper and lower halves of the matrix are driven together under pressure and then the molten PHA is adapted to the shape of the matrix, the mold then cooled to solidify the plastic (see EPSE-3). - Blow molding is used to produce bottles and other hollow objects (see EPSE-3). In this process, a molten PHA tube known as a pa ri is extruded into a closed and hollow mold. The pa ri is then expanded by a gas, pushing the PHA against the walls of a mold. The subsequent cooling hardens the plastic. The mold is then opened and the article is removed. Blow molding has several advantages over injection molding. The pressures used are much lower than in injection molding. Blow molding can typically be carried out at pressures of 25-100 psi between the plastic and the surface of the mold. For comparison, injection molding pressures can reach 10,000 to 20,000 psi (see EPSE-3). In cases where the PHA has too high molecular weights to flow easily through the molds, blow molding is the technique of choice. High molecular weight polymers (or copolymers) often have better properties than low molecular weight analogs, for example, higher molecular weight materials have a greater resistance to environmental stress cracking., (see EPSE-3) .. - It is possible to make extremely thin walls in the. blow molding products. This means that less PHA is used and the solidification times are shorter, resulting in lower costs through the conservation of the material and superior performance. Another important characteristic of blow molding is that it uses only a female mold, slight changes in the extrusion conditions and the nozzle can be used to vary the thickness of the wall (see EPSE-3 '). This is an advantage with structures whose required wall thicknesses can not be predicted in the. Advance. Evaluation of articles of various thicknesses can be undertaken, and the thinnest, lightest and cheapest item, which complies with the specifications, can be used. v Non-woven In another embodiment of the present invention, the plastic article is a non-woven material. In the sense in which it is used in the present "non-woven" it means porous, textile-like materials, usually in the form of a flat sheet, composed mainly or completely, of fibers assembled into wefts that are manufactured by processes other than spinning, weaving or weaving. A general view of non-woven fabrics can be found in the ENCYCLOPEDIA OF POLYMER SCIENCE AND ENGINEERING, Second Edition, Vol. 10, pp, 204-226 (hereinafter referred to as "EPSE-4"). Other names for these materials are joined fabrics, formed fabrics or fabrics undergoing engineering. The thickness of the cloth sheets can vary from 25 mm to several centimeters and the weight of 10 g / m ^ kg / mz Non-woven fabrics have a wide range of physical properties that depend on the material and the process used to form the weft. A fabric can be self-supporting and rigid as paper or as soft as a fabric for conventional dress.

In contrast to conventional textiles, the fundamental structure of all non-woven materials is a weft of fibers arranged more or less randomly (NONWOVENS IND., Vol. 17, p.36 (Mar. 1986), NONWOVENS WORLD, Vol. , p.36 (May-June 1986)). In this way, the key element is the individual fiber. Tension, tear and tactile properties in non-woven materials arise from adhesive or other chemicals and physical bonds, fiber to fiber friction created by entanglement and reinforcement by other materials such as foams and films (see EPSE-4) ). 1 • Method for the manufacture of non-woven fabrics The non-woven fabrics of the present invention can be manufactured by conventional techniques known in the art The production of non-woven fabrics involves: 1) manufacture of fibers of various lengths and diameters; ) create a weft of these fibers, and 3) bonding of the fibers within the weft by adhesive, or mechanical-frictional forces created by the contact of the fiber or the entanglement.

In addition to these steps, reinforcing the weft by forming a composite with other materials (e.g., yarns, canvases, films, networks and unattached wefts) is sometimes preferred. The variations of one or several of these steps allow the enormous variation of types of non-woven fiber. The term "classified fibers" was originally applied to fibers of natural origin too long to be processed in textile machines, but excluding the endless filaments, for example, silk. In the context of the present, as applied to the PHA of the present invention, the "classified fibers" are of relatively uniform length, approximately 1.3-10.2 cm, with a regular corrugation, that is, a shape similar to three-dimensional weft. Regenerated and other extruded fibers are endless fibers as they are formed. They are cut during the manufacturing process to a specific length to comply with a processing or marking need. Extruded fibers are also produced as continuous filaments without corrugation. The processes for forming wefts from graded fibers are different from those that use continuous filaments. Products obtained from classified and filamentous fiber webs can differ substantially in properties (see EPSE-4).

The mechanical properties of the fibers as defined by their chemical composition determine the final properties of the fabric. The structure of the weft and the union maximize the characteristics of the inherent fibers (see EPSE-4). Other materials that can be used in the nonwovens of the present invention in combination with the PHA are wood pulp; regenerated fibers including viscose rayon and cellulose acetate; and synthetic fibers such as poii (ethylene terephthalate) (PET), nyion-6, nylon 6,6, polypropylene (PP), and poly (vinyl alcohol). The faces of the disposable diapers or sanitary napkins produced from PHA non-woven fabrics of the present invention preferably feel dry even when the internal absorbent layer is saturated. Important fiber characteristics that affect performance include length, diameter, density, corrugated, cross-sectional shape, spin finish (lubricant that is added to the surface of the extruded fibers to improve their processing capacity), dullness (small amounts of Ti02 pigment added before extrusion to increase whiteness or to reduce brightness) and the drag ratio. 4 75 to . Methods for manufacturing the plot The characteristics of the fiber plot determine the physical properties of the final product. These characteristics depend significantly on the architecture of the fiber, which is determined by the mode of the formation of the weft. The fiber architecture includes the direction of the predominant fiber, whether it is oriented or random, the shape of the fiber (straight, bent or twisted), the degree of interfiber or tangled, corrugated coupling, and compaction (density control). Of the plot) . The characteristics of the weft are also influenced by the diameter, fiber length, weft weight and chemical and mechanical properties of the polymer (see EPSE-4). The choice of method for forming the weft is determined by the length of the fiber. Initially, the methods for forming the wefts from length-rated fibers (fibers too long to be handled by conventional spinning equipment, usually between about 1.2 and 20 cm long, but not endless) are based on the textile carding process, while the formation of the weft from short fibers is based on technologies for papermaking. Although these technologies are still in use, other methods have subsequently been developed. For example, the wefts are formed from long, virtually endless filaments directly from the bulk polymer; both the web and the fibers are produced simultaneously (see EPSE-4). A variety of methods for making wefts are known, including carding, air laying, wet forming, spinning and meltblowing. The carding process is derived from the old manual methods of fiber carding, where the natural sorted fibers i 'are handled by needle beds. In carding, heaps of sorted fibers are mechanically separated into individual fibers and formed into a coherent web by the mechanical action of the moving scales of closely spaced needles. In the air-laying process, the orientation created by the carding is improved in an efficient manner by capturing the fibers in a screen of an air stream (see United States Patent No. 3,338,992, GA Kennes, assigned to El. du 11 Pont de Nemours & Co. , Inc., granted on August 29, 1967). The fibers are separated by means of teeth or needles and are introduced in a current of air. The total randomization could exclude any preferential orientation when the fibers are collected on the screen. The wet forming processes use very short fibers. Initially, the wefts are formed of short fibers by modified paper techniques. The fibers are continuously dispersed in a large volume of water and trapped in an endless wire screen in motion. Once the screen is trapped on the screen, it is transferred to bands or felts and dried in heated drums (see EPSE-4). The process of the spin-linked weft involves making fibers and wefts simultaneously, directly from the bulk polymer. Bulk polymer is melted, extruded and dragged (often by force triboeléctricas) to filaments that are randomized and deposited in bands as a continuous frame. 'The filaments are virtually endless. The spinning process produces filament wefts with little corrugation in a normal diameter range of approximately 1.7 dtex (1.5 den) or slightly higher. The irrest regency and uniformity of the diameter of these filaments are similar to standard textile fibers and filaments (see EPSE-4). Each production line is suitable for a specific polymer and an individual binding system (see United States Patent 4, 163,305 (August 7, 1979), V. Semjonow and J. Foedrowitz (for Hoechst AG)), The wefts are also produced directly from bulk polymers by the molten sputtering process (see US Pat. United No. 3,322,607, SL Jung, assigned to The duPont de Nemours &; Co-, Inc., May 30, 1967). The molten PHA is pushed through very flax holes in a special matrix in a high velocity air stream where the PHA is formed into very fine, albeit irregular filaments of indeterminate lengths. The filaments are formed simultaneously in a web where melting and resolidification, and possibly static forces, keep them together (see EPSE-4). The plot consists mainly of filaments with very fine diameters. b. Union of the frame The union of the fibers provides the resistance of the frame and influences other properties. Both adhesive and mechanical means are used. The mechanical union uses the coupling of the fibers by friction forces. Bonding can also be achieved by chemical reaction, that is, by the formation of covalent bonds between the binder and the fibers (see EPSE-4).

G. Elastomers In another embodiment of the present invention, the plastic article is an elastomer. In the sense in which it is used in the present "Velastornero" refers to materials that exhibit both a capacity of deformation in a greater interval in the application of tension as the recovery practically complete in the elimination. can be found in the Encyclopedia of Polymer Science and Engineering, Second Edition, Vol. 5, pp. 106-127 (hereinafter referred to as "EPSE-5"). Preferably, an elastomer of the present invention, at room temperature , it can be repeatedly stretched to at least twice its original length and after removing the stress load, it will return immediately and violently to approximately its original length.The elastomers of the present invention are superior to the glass transition temperature Tg and amorphous in the tension-free state to exhibit a high local segment mobility necessary for deformation.The chains are flexible and the forces in Thermolecular (interchain) are weak. The elastomers of the present invention possess a sufficient number of physical or chemical crosslinkers to form a continuous network in order to restrict the release of the chain. The thermoplastic elastomers of the present invention have many of the properties of conventional elastomers such as for example vulcanized rubbers, although they are processed as thermoplastics instead of thermosetting. a transition from a fluid melt to a reversible ec solid. The thermoplastic elastomers of the present invention are multi-phase systems, wherein at least one phase is soft and elastic and or. i last. With thermoplastic elastomers, the transition from a processable melt to a solid, rubber-like object is fast J 1 reversible and takes place at the time of cooling. Preferably, the PHAs of the present invention that are processed in an elastomer have a sufficiently high branched content to allow them to act as thermoplastic elastomers, with crystalline areas acting as the solid segment and the amorphous segments acting as the soft segment. The thermoplastic elastomers of the present invention can be processed in conventional plastic equipment, such as injection molds. The structural parameters important for thermoplastic elastomers are the molecular weight, the soft and hard nature of the segments and the proportion of the soft to hard segments. The ratio of the soft to hard segments affects the total modulus of the elastomer, increasing with the proportion of the hard segments. The elastomers of the present invention comprising a PHA of the present invention can also be used in admixture formulations with other polymers (or copolymers), including elastomeric PHAs, to increase impact strength and hardness in more rigid materials.

H Adhesive In another embodiment of the present invention, the plastic article is an adhesive. In the sense in which it is used in the present "adhesive" means a material that joins two different materials, called ends for adhesion, together. A general analysis on adhesives can be found in the Encyclopedia of Polymer Science and Engineering, Vol. 1, pp. 547-577, (hereinafter referred to as ': EPSE-6') In one embodiment of the present invention, the adhesive is applied as a liquid, preferably of a low viscosity., the adhesive wet the surface of the end for adhesion and flows in the cracks in the surfaces of the ends for adhesion. The liquid form of the adhesive is obtained by heating to the point where the flow occurs, dissolving or dispersing the material in a solvent or initiating with liquid monomers or oligomers that polymerize or react after the application. The adhesive then goes through a phase change to a solid either on cooling, by solvent evaporation or by reaction, to bond and acquire the necessary strength to resist the cutting forces. However, pressure sensitive adhesives are an exception, as there is no phase change. The PHAs of the present invention can be processed into a variety of adhesives, including, but are not limited to, hot melt, solution, dispersion and pressure sensitive adhesives. 1. Heat Melt Adhesives As used herein, "heat melt adhesive" refers to a thermoplastic polymer or copolymer (e.g., a PHA of the present invention) that is heated to obtain a viscosity liquid or flowable and after the application is cooled to obtain a solid. In general, the molecular weight of the adhesive is made to provide melt flowability, although it is still too strong in the solid form to withstand the cutting forces experienced in the application. Due to their thermoplastic properties, the PHAs of the present invention are particularly useful as hot melt adhesives. The main characteristic of hot melt adhesives is the ability of the thermoplastic material to flow through 4, above a certain temperature, well above the normal use temperature of the joint. At the time of cooling, the material solidifies, either through the passage of the vitreous transition temperature of one of the components, or through the crystallization temperature. This solidification lends itself to physical integrity for the bond. In the PHA, the solidification mode is crystallization. 2. Solutions and Dispersions The adhesives of the present invention can be applied either as solutions, in water or an organic solvent, or in the form of aqueous dispersions. In any form, the solvent must be removed after application for the adhesive to achieve the required solid form. The solution or dispersion is normally applied to one of the surfaces to be bonded, and the solvent is removed after the second surface is joined; frequently, heating if required to facilitate the drying step. With porous substrates, such as paper or wood, the final drying can be carried out after the formation of the joint. The solids content of the solutions can vary from 5 to 95%, although values of 20 to 50% are more common. In the sense in which it is used herein, "dispersion" refers to when the adhesives are prepared by constant emulsion polymerization or dispersed as large particles in some carrier fluid. In addition to its economic advantage, dispersions containing 40 to 50% solids offer a lower viscosity than solutions, even if the solids are high molecular weight polymers (EPSE-6). The dispersions of the adhesive of the present invention can be prepared by high shear in the presence of surfactants to obtain floating formulations, procedures which are well known to those skilled in the art. 3. Pressure Sensitive Adhesives Another type of adhesive of the present invention is a pressure sensitive adhesive. Unlike other adhesives, pressure sensitive adhesives do not change their physical state from the initial application to the final break of the adhesive bond. They remain permanently deformable and can be altered even with a slight application of pressure. They are adhesives that in dry form are permanently sticky at room temperature and adhere firmly to the surface with simple contact. The most common pressure sensitive adhesive is on a backing, usually in the form of a tape. The common "maskin tape" adhesive tape, for example, is applied manually after the user removes the desired length of a roll. Many bandages are kept on the skin by pressure sensitive adhesives.

DISPOSABLE RODUCTS FOR PERSONAL CARE The present invention also relates to disposable personal care products comprising a PHA of the present invention. For example, compost-capable absorbent articles, comprising a liquid-permeable top sheet, a liquid impervious backing sheet, comprising a film of the present invention (ie, a film comprising a PHA of the present invention). invention), and an absorbent core placed between the upper canvas and the reinforcing canvas. These absorbent articles include diapers for infants, underpants and 17 incontinent adult pads and pads and linings for feminine hygiene. Additional personal care products comprising a PHA of the present invention include towels for personal cleansing; disposable health care products such as bandages, wound dressings, wound cleaning pads, surgical gowns, surgical covers, surgical pads; other institutional and disposable health care products such as gowns, towels, pads, bedding articles such as sheets and pillowcases, cushions for foam mattresses.

A, Absorbent Articles The films of the present invention used as liquid impervious reinforcing canvases in the absorbent articles of the present invention, such as disposable diapers, typically have a thickness of 0.01 mm to about 0.2 mm, preferably 0.012 mm to approximately 0.051 mm. In general, the liquid impervious reinforcing canvases are combined with a liquid permeable upper sheet and an absorbent core placed between the upper canvas and the reinforcing canvas. Optionally, the elastic members and the tape tab fasteners can be included. While the upper canvas, the reinforcing canvas, the absorbent core and the elastic members can be assembled in a variety of well-known configurations, a preferred diaper configuration is generally described in U.S. Patent 3,360,003, "entitled" Contrac tibie Side Portion for Disposable Diaper "that was awarded to Kenneth B. Buell on January 14, l 'jld. The top canvas preferably has a soft and non-irritating feel to the wearer's skin. In addition, the upper canvas is permeable to liquids, allowing the liquids to penetrate easily through its thickness. A suitable top canvas can be manufactured from a wide variety of materials such as for example porous foams, cross-linked foams, plastic films. with openings, nylon fibers (for example, wood or cotton fibers), synthetic fibers (for example, pellet or polypropylene fibers) or a combination of natural and synthetic fibers. Preferably, the upper canvas is made from a hydrophobic material to isolate the user's skin from the liquids in the absorbent core. A particularly preferred topcoat comprises fibers of rated length having a denier of about 1.5. As used herein, the term "classified length fibers" refers to those fibers having a length of at least about 16 mm. There are several manufacturing techniques that can be used to make the upper canvas. For example, the upper canvas can be woven, non-woven, joined by spinning, carding, or the like. A preferred top canvas is thermally bonded and bonded by means well known to those skilled in the art of fabrics. Preferably, the top sheet has a weight of between about 18 and 25 g / m2, a minimum dry tensile strength of at least about 400 g / cm in the machine direction and a wet tensile strength of less about 55 g / cm in the cross-machine direction.

In a preferred embodiment of the invention, the top sheet comprises a PHA of the present invention. The upper canvas and the reinforcing canvas are joined together in any suitable manner. In the term in which it is used in the present, the term "attached" encompasses configurations according to which the upper canvas is directly attached to the reinforcing canvas by fixing the upper canvas directly to the reinforcing canvas, and the configurations according to which the upper canvas indirectly joins the reinforcing canvas when fixing the. canvas superior to the intermediate members which in turn are fixed to the reinforcing canvas. In a preferred embodiment, the upper canvas and the reinforcing fabric are fixed directly together at the periphery of the diaper by attachment means such as adhesive or any other joining means known in the art. For example, a continuous, uniform adhesive layer, a patterned adhesive layer or an array of separate lines or spots of adhesive may be used to secure the upper canvas to the reinforcing canvas.

In a preferred embodiment of the present invention, the adhesive comprises a PHA of the present invention. Tape tab fasteners are typically applied to. the rear waistband region of the diaper to provide a fastening means for holding the diaper on the wearer. The tape tab fasteners may be any of those known in the art, such as the fastener tape, set forth in United States Patent 3,848,594 issued to Kenneth B. Buell on November 19, 1974. These fasteners are made of tape. Tape or other means to fasten the diaper-typically are applied near the corners of the diaper. < Preferred diapers have elastic members positioned adjacent the periphery of the diaper, preferably along each longitudinal edge such that the elastic members tend to shrink and hold the diaper against the legs of the wearer. The elastic members are secured to the diaper in a condition that can be contracted in such a way that in a normally unrestricted configuration, the elastic members effectively contract or fold the diaper. The elastic members can be secured in a contractile condition in at least two ways. For example, the elastic members can be stretched and secured while the diaper is in an uncontracted condition. Alternatively, the diaper can be contracted, for example, by refolding an elastic member secured and connected to the diaper while the elastic members are in their relaxed or unstretched condition. Elastic members can take a multitude of configurations. For example, the width of the elastic members may vary from about 0.25 mm to 25 mm or more; the elastic members may comprise a single strand of elastic material or the elastic members may be rectangular or curvilinear. Still further, the elastic members can be attached to the diaper in various ways that are known in the art. For example, the elastic members can be sealed by heat and pressure, ultrasonically joined to the diaper using a variety of bonding patterns or the elastic members can simply be attached to the diaper.

In a preferred embodiment of the present invention, the elastic members comprise a PHA of the present invention. The absorbent core of the diaper is placed between the upper canvas and the reinforcing canvas. The absorbent core can be manufactured in a wide variety of sizes and shapes (eg, rectangular, hourglass, asymmetric, etc.) and a wide variety of materials. The total absorbent capacity of the absorbent core must, however, be compatible with the liquid cargo designed for the intended use of the absorbent article or diaper. In addition, the size and absorbent capacity of the absorbent core can vary to suit users from small children to adults. A preferred embodiment of the diaper has an absorbent core in the shape of an hourglass. The absorbent core is preferably an absorbent member comprising an air felt fabric or fiber, wood pulp fibers and / or a particulate absorbent polymer composition placed therebetween. In a preferred embodiment of the present invention, the absorbent polymer composition of the absorbent core comprises a PHA of the present invention. Other examples of absorbent articles according to the present invention are sanitary napkins designed to receive and contain vaginal discharges such as menstruation. Disposable sanitary napkins are designed to be held adjacent to the human body by means of a garment, such as an undergarment or pant or by a specially designed band. Examples of the kinds of sanitary napkins to which the present invention readily adapts are known from U.S. Patent 4,687,478, entitled "Shaped Sanitary Napkin With Flaps" which was given to Kees J, Van Tilburg on August 18, 1987, and in U.S. Patent 4,589,876, entitled "Sanitary Napkin" which was granted to Kees J. Van Tilburg on May 20, 1986. It will be apparent that the films of the present invention which comprise a PHA of the present, described therein, can be used as the waterproof reinforcing canvas of these sanitary napkins. On the other hand, it will be understood that the present invention is not limited to any specific sanitary towel configuration or structure. In general, sanitary napkins comprise a liquid-impermeable backing sheet, a liquid-permeable top sheet and an absorbent core placed between the backing sheet and the top sheet. The reinforcement web comprises a PHA of the present invention. The upper canvas can comprise any of the upper canvas materials analyzed with respect to the diapers. The adhesives used may comprise a PHA of the present invention. The absorbent core can comprise any of the absorbent core materials analyzed with respect to the diapers, among which a PHA of the present invention is included. Importantly, the absorbent articles according to the present invention are biodegradable and / or capable of composting to a greater degree than conventional absorbent articles employing materials such as a polyolefin reinforcement sheet (e.g., a polyethylene) .

EXAMPLE 1 Poly (3-hydroxybutyrate-co-3-hydroxy-methyldvalerate) The poly (3-hydroxybutyrate-co-3-hydroxy-4-methylvalerate) is prepared according to the general methods described above and is based on the published procedure of Hoi et al. (Hoi, Y-, M. Suzuki, Y. Takahashi, A. Yomaguchi, and T. Neshishita, MACROMOLECULES, Vol. 26, pp. 5533-5534 (1993)) for the polymerization of β-butyrolactone. Specifically, the purified [S] -3-met.ilpropiolactcna ([S] -β-butyrolactone) (9.5-0 g, 110 mmol) and [S] -3-isopropylpropiolactone (0.83 g, 5.8 mmol) are charged to a sealed glass tube with packing, purged with argon, dry, by means of a syringe. The initiator, 1,3-dichloro-1,3,3-tetrabutyldistanoxane prepared according to R. Okawara and M. Wada, (J. ORGANOMET. CHEM. (1963), Vol. 1, pp. 81-88. ) and dried overnight at 80 ° C, dissolved in dry toluene to produce a 0.18 M solution. Using a syringe, 0.65 mL of the initiator solution (0.12 mmoles disoxane) is added to the tube. The tube is gently swirled to mix the contents and then heated at 100 ° C for 4 hours by immersing its lower half in an oil bath.As the reaction proceeds, the contents of the tube become viscous. , the tube is removed from the oil bath and allowed to cool to room temperature The solid is dissolved in chlorofrure, recovered by precipitation in a hexane-ether mixture, collected by filtration and dried under vacuum The comonomer composition of the copolymer is determined by XH-NMR spectroscopy and was found, within the experimental ror, which is the same as the load ratio (95: 5). The molecular weight was determined by size chromatography with chloroform as the mobile phase, and narrow polystyrene standards were used for calibration.

EXAMPLE 2 Poly (3-hydroxy-lerato-co-3-hydroxy-4-methylvalerate) The poly (3-hydroxy-valerate-co-3-hydroxy-4-methyl-valerate) is prepared following the same procedure of Example 1, except for using [S] -3-ethylpropiolactone (9.50 g, 94.9 mmol) and [S] -3-isopropylpropiolactone (0.71 g, 5.0 mmol) as the monomeric charge.

EXAMPLE 3 Poly (3-hydroxybutyrate-co-3-hydroxy-valerate-co-3-hydroxy-4-methylvalerate) Poly (3-hydroxybutyl-co-3-hydroxy-valerate-co-3-hydroxy-4-methylvalerate) is prepared following the same procedure of Example 1, with the exception that [S] -3-methylpropiolactone (7.20 g, 83.6 mmol), [S] -3-ethylpropiolactone (1.14 g, 11.4 mmol) is used; and [S] -3-isopropylpropiolactone (0.71 g, 5.0 mmol) as the monomeric charge.

EXAMPLE 4 Poly (3-hydroxy-butyrate-co-3-hydroxy-4-methylvalerate-co-3-hydroxyoctanoate) Poly (3-hydroxybutyrate-co-3-hydroxy-4-methyldvalerate-co-3-hydroxyoctanoate) . is prepared following the same procedure of Example 1, with the exception that [S] -3-methylpropiolactone (9.50 g, 110 mmol), [S] -3-isopropylpropiolactone (0.41 g, 2.9 mmoies) was used, and [SJ-3-pentylpropiolactone (0.50 g, 2.9 mmol) as the monomeric charge i.

EXAMPLE 5 Poly (3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxy-4-methylvalerate-co-3-hydroxyoctanoate) Poly (3-hydroxybutyrate-co-3-hydroxy-valerate-co-3-hydroxy) -4-methyl-valerate-co-3-hydroxy-octanoate) is prepared following the same procedure as in Example 1, with the exception that [S] -3-methopropiolactone (7.20 g, 83.6 immoles), [S] - 3-yl-propiolactone (1.14 g, 11.4 mmol), [SJ -3-isopropylpropiolactone (0.36 g, 2.5 mmol), and [S] -3-pentylpropiolactone (0.43 g, 2.5 mmol) as the monomeric charge.

EXAMPLE 6 Single layer film capable of composting The poly (3-hydroxybutyl-co-3-hydroxy-4-methylvalerate) copolymer (PHBMV) of the composition of 5 mol% methylvalerate / 95 mol% butyrate is Insert into an individual screw extruder (Rheomix Model 202) with diameter 0.75 inch screw A constant tapered screw having a 20: 1 ratio of length to diameter and a compression ratio of 3: 1 is employed. The temperature of both heating zones of the extruder barrel is 25 ° C higher than the melting temperature of the PHBMV. The extruder is equipped with a 6-inch wide mold and a 0.04-inch mold opening. The mold is maintained at 20 ° C above the melting temperature of the PHBMV. The copolymer melts into the extruder and is pumped into the mold at the other end of the extruder. The screw rpm remains constant at 30 rpm. The copolymer is pushed through the mold and collected on an extraction roller collection system (Postex) at a rate that allows crystallization of the polymer before extraction. The width of these films is nominally 4 inches and the thickness is approximately 0.002 inches.

EXAMPLE 7 Single layer film capable of composting PHBMV films (95: 5) are produced by melting the material between sheets of Teflon in a Carver Press (Fred S. Carver Inc., Menomonee. Falls, Wl) a 20 ° C above the melting temperature. The pressure in the sheets is adjusted to produce films approximately 0.25 mm thick. The films are cooled identically to room temperature by placing the molds between long aluminum plates (5 kg) and allowing the films to cool to room temperature.

EXAMPLE 8 Multilayer film capable of composting The PHBMV film sheets can be prepared as in Example 6 of the compositions of PHBMV (95: 5) and PHBMV (50:50). These sheets can then enclose a sheet of a polymer having good oxygen barrier properties but a poor water vapor transmission rate, or a polymer film that can be soluble in water such as a poly (vinyl alcohol) ( PVA). The films are placed in an accumulated Carver Press in the following order PHBMV (95: 5), PHBMV (50: 50), PVA, PHBMV (50: 50), PHBMV (95: 5). The material is then subjected to pressure at a temperature of 5 ° C above the melting temperature of the PHBMV (50: 50), although below the melting temperature of the PHBMV (95: 5). After compression at 2000 Ib for 30 minutes, the pressure is released and the film is allowed to cool to room temperature.

EXAMPLE 9 Disposable diaper with compost capability A disposable baby diaper in accordance with this invention is prepared as follows. The dimensions listed are for a diaper that is intended to be used with a child in the size range of 6 to 10 kilograms. These dimensions can be modified proportionally for children of different sizes, or for trusses of adults with incontinence, according to standard practice. 1. Reinforcement web: 0.020-0.038 mm film consisting of a 92: 8 copolymer (3-hydroxybutyrate-co-3-hydroxy-methyl-valerate) (prepared as described in Example 1); wide at the top and at the bottom of 33 was; cut inward on both sides to a width in the center of 28.5 cm; length of 50.2 cm. 2. Top canvas: polyethylene fibers of carded and thermally bonded classified length (Hercules polypropylene type 151); width at the top and bottom 33 cm; cut inwards on both sides to a width in the center of 28.5 cm; long of 50.2 in. 3. Absorbent core: comprises 28.6 g of pulp of cellulose wood and 4.9 g of particles of * absorbent gelling material (Nippon Shokubai commercial polyacrylate); 8.4 mm thick, calendered; width at the top and bottom of 28.6 cm; cut inward on both sides to a width in the center of 10.2 cm; length of 44.5 cm. 4. Elastic bands for the leg: four individual rubber strips (2 per side); width of 4.77 mm; length of 370 mm; thickness of 0.178 mm (all previous dimensions are in relaxed state). The diaper is prepared in a standard way by placing the core material covered with the upper canvas on the reinforcing canvas and applying glue. Elastic bands (designated "internal" and "external", corresponding to the bands closest to and farthest from the core, respectively) are stretched to approximately 50.2 cm and are placed between the upper canvas / reinforcement canvas between each longitudinal side (2 bands per side) of the core. The inner bands along each side are placed approximately 55 mm from the narrowest width of the core (measured - from the inner edge of the elastic edge). This provides a spacer element along each side of the diaper comprising the upper canvas material / flexible reinforcing fabric 1 between the inner elastic and the curved edge of the core. The inner bands stick down along their length in the stretched state. The outer bands are placed approximately 13 mm from the inner bands and stick down along their length in the stretched state. The upper canvas / reinforcement canvas assembly is flexible and the bands taped down contract to stretch the sides of the diaper.

EXAMPLE 10 Light weight tampon with capacity to form compost A lightweight tampon suitable for use between menstrual periods comprises a pad (surface area 117 sec2; air felt SSK 3.0 g) containing 1.0 g of particles. of absorbent gelling material (commercial polyacrylate, Nippon Shokubaí); the pad is interposed between a porous, film-formed top canvas according to U.S. Patent 4,463,045 and a reinforcing scrim comprising a 0.03 mm thick 92: 8 copolymer film of poly (3-hydroxybutyrate) copolymer. co-3-hydroxy-4-methylval time), as prepared according to Example 1.

EXAMPLE 11 Sanitary towel with capacity to form compost A catamenial product in the form of a sanitary napkin having two wings extending out from its absorbent core is prepared using a pad in the shape of Example 10 (surface area of 117 cm 2; 8.5 g of SSK air felt), by the design of U.S. Patent 4,687,478, Van Tillburg, August 18, 1987. The canvas materials of. reinforcement and top canvas are the same as those described in Example 10.

EXAMPLE 12 Sheet with capacity to form compost The process of preparation of the film of Example 6 is modified by replacing the mold in the extruder with a mold with an opening thickness of approximately 0.25 cm and width of .15 cm. The extraction after the extrusion is carried out by inserting the sheet that emerges • from the extruder between two counter-rotating cylinders. The sheet is extracted from the extruder "in this way and lengths of 32 cm are cut, obtaining leaves approximately 13 cm wide and 0.18 cm thick.

EXAMPLE 13 Fiber with capacity to form compost The PHBMV of the 5% molar composition of methylvalerate / 95% molar butyrate is introduced into a single screw extruder (Rheomix Model 202) with a screw diameter of 0.75 inches. A constant tapered screw having a ratio of 20: 1 in length to diameter and a ratio of 3: 1 compression is employed. The temperature of both heating zones of the extruder barrel is 25 ° C above the melting temperature of the PHBMV. The extruder is equipped with nozzle mold containing 5 holes of 500 mm diameter. The mold is maintained at 20 ° C above the melting temperature of the PHBMV. The polymer melts inside the extruder and is pumped into the mold at the other end of the extruder. The screw rpm remains constant at 30 rpm. The polymer is pushed through the mold and the molten extruded fibers are conducted through a region where a fast air stream is applied such that the polymer fibers are elongated and thinned to about one fifth of the diameter of the fibers. holes (approximately 100 mm). The fibers are collected on a cardboard mat. A wide distribution of fiber lengths of several centimeters in length is obtained. Most of the fiber lengths (more than 50%) are in the range of 1.3 to 15 cm.

EXAMPLE 14 Rigid foam with capacity to form compost The PHBMV (40 g) of the composition of 5 mol% of meth iivalerat or 95 mol% of butyrate and 4 g of a common blowing agent, p, p '-oxi-bis benzenesulfonhydrazide are charged to a mixing chamber of a Rheomix type 600 fusion mixer equipped with rotating knives. The temperature of the mixing chamber is increased above the melting temperature of the PHBMV, although below the degradation temperature of the blowing agent (158 ° C), after mixing for 10 minutes at 60 rpm, the mixture of The copolymer is collected and transferred to a heated aluminum tray, extending approximately in such a way that the resulting mass is approximately 0.5 cm thick. The copolymer is then placed in an oven (National Appliance Company, model 5830) and heated to the melting temperature of the PHBMV again, and it is maintained at that temperature until the copolymer is completely melted (at about 5 minutes). The temperature of the furnace is then increased to 160 ° C, at that temperature, the blowing agent degrades and the copolymer initiates the foaming process. At this point the copolymer foam is removed from the furnace and placed in a second furnace at a maximum crystallization rate of the PHBMV (approximately 80 ° C). The copolymer is left in this oven for 6 hours. EXAMPLE 15 Flexible foam with the ability to form compost The procedure of Example 14 is used with the following modifications: 40 g 0 of poly (3-hydroxybutyrate-co-3-hydroxy-4-methylvalerate) copolymer of the composition of 60% molar methylvalerate / 40% molar butyrate (PHBMV (40:60)) instead of PHBMV (95: 5).

EXAMPLE 16 Molded article with the ability to form fertilizer Injection molded articles are obtained by using a Mini Max Model CS-183 Moulder (Custom Scientsific Instruments, Whippeny, N.J.). The temperature of the rotor and the stator cuvette is kept constant at 20 ° C above the melting temperature of the polyhydroxyalkanoate used. Approximately 0.5 grams of PHBMV (95: 5) are charged to the stator bucket and allowed to melt for 3 minutes. The molten copolymer is mixed radially as the tilt of the rotor increases and decreases five times. A steel mold in the shape of a weight is sprayed with a light coating of silicone release in the mold. The mold is placed in the mold support wheel of the Mini Max molding machine and the molten polymer is injected into the mold by the action of the tilt of the rotor. The copolymer is molded into dumbbell-shaped pieces 0.03 inches thick, 1 inch wide, 0.125 inches wide in the middle part of the piece and 0.25 inches wide at the ends. These molded parts are suitable for mechanical testing. - • y 1 1 0 E JEMPLO 17 S 1 Non-woven fabric with capacity to form fertilizer Poly (3-hydroxybutyrate-co-3-hydroxy-4-methylvalerate) copolymer (PH3MV) of the composition 2% molar methylvalerate / 98% molar of butyrate is introduced into a single screw extruder (Rheomix Model 202, Paramus, NJ) with a screw diameter of 0.75 inches. A constant taper screw having a 20: 1 ratio of length to diameter and a compression ratio of 3: 1 is employed. The temperature of the two heating zones of the extruder barrel is 25 ° C above the melting temperature of the PHBMV. The extruder is equipped with a mold with nozzle containing 5 holes 500 mm in diameter. The mold is maintained at 20 ° C above the melting temperature of the PHBMV. The poiimer melts into the extruder and is pumped into the mold at the other end of the extruder. The screw rpm remains constant at 30 rpm. The polymer is pushed through the mold and the molten extruded fibers are led through a region where a fast air stream is applied such that the polymer fibers are elongated and thinned to about one fifth of the diameter of the fibers. holes (approximately 100 mm). The fibers are collected on a cardboard mat. The mat moves in such a way that an area of 10 cm x 10 cm is covered evenly with the fibers. The collection of fibers on the mat continues, until there is a fiber mat approximately 0.5 cm thick. A wide distribution of fiber lengths to several inches in length is obtained. Most fiber lengths (more than 50%) are in the range of 0.5 to 6 inches. The mat is then transferred to a Carver Press (Fred S. Carver Inc., Menomonee Falls, Wl) and pressurized to 1000 Ib of force for 10 minutes at a temperature of 5 ° C below the melting temperature of the PHBMV. . The resulting non-woven sheet is removed from the press.

EXAMPLE 18 Elastomer with capacity to form compost PHBMV films (70:30) are produced by melting the material between sheets of Teflon at 20 ° C above the melting temperature. The pressure on the sheets is adjusted to produce films approximately 0.5 mm thick. The films are then cooled identically to room temperature by placing the molds between long aluminum plates (5 kg) and allowing the films to cool to room temperature. The films are allowed to age for 2 days, then subsequently cut into strips 10 cm long and 1 cm wide. The strips are then placed in an Instron universal test machine (Model 1122, Canton, MA) and elongated at a rate of 1 inch / minute until an elongation of 300% of the original length is achieved. The films are kept elongated for two days until an additional crystallinity develops. The strips are removed from the Instron and at the time of a subsequent extension, the material returns to its previous length (after treatment in the Instron).

EXAMPLE 19 Adhesive with capacity to form compost PHBMV (50:50) can be used as a hot melt adhesive in the following way. Approximately PHBMV (50:50) Ig is placed between two polymer films, such as poly (vinyl alcohol) (PVA), or poly (3-hydroxylbutyrate) (PHB) or any other PHA having a temperature of fusion of at least 10 ° C higher than PHBMV (50:50). The film / adhesive assembly is placed in a Carver Press (Fred S. Carver Inc., Menomonee Falls, Wl) and then pressurized to a temperature of 5 ° C above the melting temperature of PHB: MV ( 50:50). After compression at 2000 Ib of force for 30 minutes, the pressure is removed and the bonded film assembly is allowed to cool to room temperature. All publications mentioned above are hereby incorporated by reference in their entirety. It should be understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes may be suggested in the light thereof by someone skilled in the art and should be included in the spirit and essence of this. application and the scope of the appended claims.

Claims (19)

1. * CLAIMS 1. A plastic article other than a film comprising a biodegradable copolymer, wherein the biodegradable copolymer comprises at least two randomly repeating monomer units, wherein the first randomly repeating monomeric unit has the structure wherein] is H, or Ci or C alkyl and n is 1 or 2; the second unit - random repetition monomer has the structure and wherein at least 50% of the randomly repeating monomer units have the structure of the first monomeric random repeat unit.
2. 2. The plastic article according to claim 1, wherein R1 is a Cx or C2 alkyl and n is 1.
3. 3. The plastic article according to claim 2, wherein R1 is a Ci alkyl.
4. 4. The plastic article according to claim 1, wherein R1 is H and n is 2.
5. 5. The plastic article according to claim 1, wherein the plastic article is a fiber.
6. 6. The plastic article according to claim 1, wherein the plastic article is a foam.
7. 7. The plastic article according to claim 1, wherein the plastic article is a molded article.
8. 8. The plastic article according to claim 1, wherein the plastic article is a non-woven fabric.
9. 9. The plastic article according to claim 1, wherein the plastic article is an elastomer. 116
10. 10. The plastic article according to claim 1, wherein the plastic article is an adhesive.
11. 11. The plastic article according to claim 1, wherein the plastic article is a sheet.
12. 12. The article by. The plastic according to claim 1, wherein the copolymer comprises one or more additional randomly repeating monomer units. the structure wherein R3 is H, or a C1-C19 alkyl or alkenyl; and m is 1 or 2; and wherein the additional random repetitive monomer units are not equal to the first random repeat monomer unit or the second monomeric random repeat unit.
13. 13. The plastic article according to claim 12, wherein the plastic article is a fiber.
14. 14. The plastic article according to claim 12, wherein the plastic article is a foam.
15. 15. The plastic article according to claim 12, wherein the plastic article is a molded article.
16. 16. The plastic article according to claim 12, wherein the plastic article is a non-woven fabric.
17. 17, The plastic article according to claim 12, wherein the plastic article is an elastomer.
18. 18. The plastic article according to claim 12. wherein the plastic article is an adhesive.
19. 19. The plastic article according to claim 12, wherein the plastic article is a sheet.