CN1326940C - Hydroxyl radical alkanoate multipolymer/amylum composition for manufacturing laminated material and film - Google Patents

Abstract

Films comprising a blend of polyhydroxyalkanoate copolymer and destructured starch are disclosed. Laminates having a first layer comprising a PHA copolymer and a second layer comprising a PHA copolymer/starch blend or thermoplastic starch are also disclosed. Disposable articles comprising the environmentally degradable films or laminates are also disclosed.

Description

Be used to make the polyhydroxy alkanoate copolymer/starch composites of laminating material and film

Invention field

The present invention relates to comprise the film of polyhydroxyalkanoatefrom (PHA) multipolymer/modified starch blend.Also disclose the laminating material with the first layer and second layer, described the first layer is made up of pha copolymer basically, and the described second layer comprises pha copolymer/modified starch blend or thermoplastic starch.Film or laminating material are used to prepare the disposable product of degraded by environment, are particularly useful for the degraded under the oxygen free condition.

Background of invention

The present invention relates to alleviate the needs of growing environmental problem, described environmental problem is meant that too much plastic refuse causes material volume mark cumulative in the garbage bury ground.Based on the requirement of the volume that reduces the annual solid waste that is produced by the human consumer, biodegradable polymkeric substance and just become by the product of biodegradable polymer formation becomes more and more important.The invention still further relates to the demand of development of new plastic material, this material can be used for the application that biological degradability, compostability and biocompatibility are main expectation characteristics, especially under oxygen free condition.Carry out many trials and made degradable product.Yet, because how many business success are factors such as cost, difficulty of processing and end-use energy almost do not obtain.Many compositions with splendid degradation property only have limited workability.On the contrary, be easy to composition processed and have relatively poor degradability.

Traditional disposable absorbent products has had compostability to a great extent.For example, typical disposable diaper contains 80% the compost material of having an appointment, for example, and wood pulp cellulose etc.Yet, the polyethylene egative film in the absorbent article need be replaced to the film of liquid-tight compost material especially, because one of maximum not compost component in the normally traditional disposable absorbent article of egative film.

In order to produce film, select acceptable biological degradation polyalcohol with challenging with the end-use that is easier to accept.Degradable polymer should be thermoplastic, so that can adopt conventional processing film method, comprises the continuous production on the conversion machining production line.In addition, importantly film or big film fragments form much smaller particle in the starting stage of compost through initial disintegration.

In addition, people have produced interest to the ventilation property of disposal sanitary article gradually, and this ventilation property is used for farthest reducing and the relevant sense of discomfort of high humidity accumulation.People are used to make this series products to the ventilative film that can receiving fluids allows moisture partly to see through simultaneously and nourish special interest.Before stretched operation,, filling agent particle controls the aperture in the film matrix by evenly and very being dispersed in meticulously.Material as polyolefine, has very low avidity to the weighting agent surface, thereby is difficult to obtain good particles dispersed.Polyester has preferably to a lot of solid surface that avidity makes that particle is easier to sprawl, yet if interact too by force, just can not produce the physical disturbance in required formed hole at the interface when stretching between weighting agent and film matrix.Ventilative film needs to produce with weighting agent the interactional material of proper level.And these materials must can fully extend basically, to prevent that macroscopical physical disturbance produces big tearing in the drawing process.For example, typical aromatic polyester such as polyethylene terephthalate are too fragile and can not tolerate local mechanical destruction around the single filling agent particle.

Normally hemicrystalline, the thermoplastic poly ester cpds of polyhydroxyalkanoatefrom (PHAs), as isotactic poly (3-butyric ester) or PHB, and isotaxy (3-hydroxyl fourth-acid esters-hydroxyl valerate) multipolymer or PHBV.Two kinds of multipolymers all have high crystalline and frangible/fragile shortcoming.Because crystallization velocity is slow, even after cooling, also can adhere to each other by the film of PHBV preparation; Most of PHBV is still amorphous in long-time and is clamminess.In operation of injection moulding film and blown film operation, residual tackiness has limited processing.In the polyhydroxyalkanoatefrom of long-chain by the time, as isotactic poly Hydroxyoctanoic acid ester (PHOs), because multiple amyl group and high-grade alkyl group side chain, it comes down to unbodied.If exist, yet their crystallising part has very low fusing point and extremely low crystallization velocity.For example, people such as Gagnon at " macromole " (Macromolecules), 25, among the 3723-3728 (1992)-be incorporated herein by reference-show temperature of fusion about 61 ℃, under its best Tc, reach maximum degree of crystallinity through about 3 weeks.

In addition, the composition of poly-(3-hydroxyalkyl acrylate) multipolymer is by Kaneka (United States Patent (USP) 5,292,860) and Procter ﹠amp; Gamble (United States Patent (USP) 5,498,692; 5,536,564; RE36,548; 5,685,756; 5,942,597; 5,990,271; 6,160,199) open.All these patents have all been described multiple degree of crystallinity and the fusing point method of adjusting to any required respective value that is lower than high-crystallinity PHB or PHBV with PHA, specifically are by introducing " defective " that part stops the manipulated variable of crystallisation process along main chain is random.The structure of miocrystalline multipolymer can be adjusted to fusion in the typical use range between 80 ℃ to 150 ℃, and the influence of degradation is less in the course of processing.In addition, because these multipolymers have lower degree of crystallinity and microorganism is had bigger susceptibility, their biodegradation rate is higher.Although the mechanical property of these multipolymers and melt-processed condition improve to some extent than PHB or PHBV usually, their crystallization velocity is low significantly, is usually less than PHB and PHBV.

Usually, the pha copolymer that these are newer and other biodegradable polymkeric substance, it is sizable challenge that the melting method by routine converts useful form to always.Polymkeric substance still has sizable viscosity after cooling down from its melt, like this always before obtaining enough degree of crystallinity, especially is higher than the pha copolymer of 10% weight percent for noncrystalline component concentration.Remaining tackiness typically can cause material to be adhered together or to adhere on the processing units, or simultaneously both of these case takes place, thus the production rate of limit polymerization produce product, or hinder product and collect with the quality form that is fit to.

For the production environment degradable product, people use the existing technology of knowing in the plastics industry, attempt processing on standard equipment native starch.Because native starch generally has grainy texture, therefore need sex change before melt-processed.The fusion extensibility of having found the starch (one-component or as the main component of mixture) after the modification is relatively poor, therefore wants successful producd fibers, film, foam or analogue that certain difficulty is arranged.

Be film or the laminating material that production has more acceptable processability and final use properties, biodegradable polymkeric substance needs and starch combines.Acceptable be suitable for the selection of the mixed biodegradable polymers of starch challenging.Biodegradable polymkeric substance must have suitable temperature of fusion.This temperature of fusion must be enough high, with the stability that guarantees finally to use, thereby prevent fusion or structural distortion, but temperature of fusion again can not be too high, so that starch can be processed and unlikely burning starch.These require to make that the selection of biodegradable polymers becomes very difficult when producing the film that contains starch.In addition, blend must be processed on the equipment for making film of routine.

United States Patent (USP) 5,874,486 disclose thermoplastic polymer components that includes starch ingredients and at least a certain synthetic that has disperseed weighting agent therein and the polymer composition that comprises the matrix of liquid agent.United States Patent (USP) 6,117,925 disclose the mixture of starch and certain hydrophobic polymer product of transesterification reaction.United States Patent (USP) 6,096,809 disclose the composition that comprises thermoplastic starch and at least a certain polymkeric substance, and wherein the water-content of composition is lower than 1% under melted state.United States Patent (USP) 5,844,023 disclose basically by thermoplastic starch and at least a certain polymkeric substance be used for the molecule coupling biphase polymeric dispersant formed of the mixture of blender mutually.Can improve miscibility, workability, structure, sense of touch and the tackiness of composition in the prior art.

Making for ventilative film, need the material of exploitation degraded by environment, this material has suitable avidity for solid weighting agent surface, thereby obtains good particles dispersed, and soft also being easy to extended, and destroys and produces aperture thereby only have local mechanical after stretching.

Summary of the invention

The invention discloses the blend film of the melt-processed of the degraded by environment that comprises polyhydroxy alkanoate copolymer (PHA) and modified starch.The invention also discloses the laminating material that comprises the first layer and the second layer, described the first layer is basically by pha copolymer of the present invention, and the described second layer comprises pha copolymer of the present invention/modified starch blend or thermoplastic starch of the present invention.With independent pha copolymer or separately starch film relatively, this class blended composition or laminating material provide any one or multiple different and the performance of improving.For example, the difference of intermingling material or laminating material and the performance of improvement comprise for example hardness/softness, fragility/flexible, tackiness, viscosity, toughness, ductility, workability, opacity/transparency, or in the ventilative property any one.In addition, the invention discloses the gas permeable film that comprises the PHA/ starch blending.The invention also discloses the disposable product of the film that comprises degraded by environment.Mixture of the present invention is when keeping flexibility and flexible feature, and is all biodegradable under aerobic and oxygen free condition, not very sensitive to moisture, and good shelf life stability is arranged.

The most surprising aspect is not need the starch softening agent can make the mixture fusion have workability during with PHA and starch mixing.Starch can sex change in water.Water base then modified starch energy and PHA chemical combination, and then drainage water can not influence its molecular weight distribution conversely because of the PHA hydrolysis-stable simultaneously.

Detailed Description Of The Invention

Copolymer compositions used herein is by mole per-cent.Except as otherwise noted, all other per-cents used herein, ratio and ratio all are the weight percent meters by composition.

This specification sheets comprises following detailed description: (1) material of the present invention, the performance of (2) film or laminating material, the manufacture method of (3) film or laminating material and (4) disposable products.

The present invention relates to comprise the film or the laminating material composition of polyhydroxy alkanoate copolymer and modified starch.Polyhydroxy alkanoate copolymer causes film or laminating material environment degradable apace, especially under oxygen free condition.Starch is totally biodegradable.PHA/ starch blend of the present invention is to moisture stabilization, and the goods that prepare with this mixture still keep snappiness.The invention still further relates to the gas permeable film that comprises pha copolymer/starch blend.Starch produces aperture during for stretch process nucleator is provided, thereby as particles filled dose.Yet, in the air-permeating film composition that particles filled dose can be added to pha copolymer/starch.

(1) Material

Polyhydroxy alkanoate copolymer (PHAs)

Biodegradable film or laminating material are partly by the preparation of compositions that comprises biodegradable first polyhydroxy alkanoate copolymer at least, and described polyhydroxy alkanoate copolymer comprises at least two kinds of random repeated monomer unit (RRMU).The one RRMU has formula (I):

R wherein ¹Be H or C1 or C2 alkyl, n is 1 or 2.In preferred embodiments, R1 is methyl (CH ₃).In another preferred embodiment of a RRMU, R1 is a methyl, and n is 1, and polyhydroxy alkanoate copolymer comprises the 3-hydroxybutyrate units thus.

The 2nd RRMU that is included in the biodegradable polyhydroxy alkanoate copolymer comprises at least a monomer, and this monomer is selected from by structure (II) and the group (III) formed:

R wherein ²For C3-C19 alkyl or C3-C19 alkenyl and

Wherein m is 2 to about 9.Usually, in the RRMU of formula (II), R ²Length will influence the whole crystalline reduction of multipolymer to a certain extent.In preferred embodiments, R ²Be C3-C15 alkyl or alkenyl.In another preferred embodiment, R ²Be the C3-C9 alkyl; In going back another preferred embodiment, R ²Be C5 or C7 alkyl.In selective embodiment preferred, R ²Be C15-C19 alkyl or alkenyl.In the RRMU of formula (III), (CH ₂) _mLength will influence the whole crystalline reduction of multipolymer to a certain extent.In preferred embodiments, m is 2 to 9, more preferably 2 to 5.In a further preferred embodiment, m is 5.

Preferably, for when using the polyhydroxyalkanoatefrom composition, obtaining the favourable combination of the physical properties that film has, comprise the have formula RRMU of the one RRMU structure of (I) at least about 50% multipolymer by mole.What be fit to is that the mol ratio of a RRMU and the 2nd RRMU is about 50: 50 to about 98: 2 in the multipolymer.More preferably, mol ratio is about 75: 20 to about 95: 5, in addition more preferably mol ratio at about 80: 20 to about 90: 10 scope.In addition, the suitable number-average molecular weight of polyhydroxy alkanoate copolymer is greater than about 150,000 gram/moles, and has the fusing point of being appointed as Tm1 in addition.

In another embodiment of first polyhydroxy alkanoate copolymer that is used for the laminated film composition, can comprise one or more additional RRMU.What be fit to is that additional RRMU can have structure (IV):

R wherein ⁵Be H or C1-C19 alkyl or alkenyl, and s is 1 or 2, collateral condition is that additional RRMU is different from a RRMU or the 2nd RRMU.

In another preferred embodiment, the polyhydroxyalkanoatefrom composition comprises the biodegradable second polyhydroxyalkanoatefrom homopolymer or multipolymer or its blend in addition.Preferred the 2nd PHA polymkeric substance or multipolymer comprise at least a random repeated monomer unit with structure (V):

R wherein ³Be H or C1 or C2 alkyl, and p is 1 or 2.In preferred embodiments, R ³Be methyl (CH ₃).In a further preferred embodiment, R ³Be methyl, and p is 1, second polyhydroxyalkanoatecopolymers copolymers comprises the 3-hydroxybutyrate units thus.In a further preferred embodiment, second polyhydroxyalkanoatecopolymers copolymers is the polyhydroxybutyrate ester homopolymer.Can be randomly, second polymkeric substance of degraded by environment comprises that two or more are selected from structure (V) and additional random repeated monomer unit (VII):

R wherein ⁴For C2-C19 alkyl or C2-C19 alkenyl and

Wherein q is 2 to about 16.For comprising monomeric the 2nd RRMU of structure (VII), in preferred embodiments, q is 2 to about 10, more preferably about 4 to about 8.In another preferred embodiment, q is about 5.When existing, the unitary content of additional random repeated monomer is no more than 25% by total monomer units, preferably is less than 15%, and wherein the second polyhydroxyalkanoatefrom homopolymer or multipolymer suitably have greater than about 50, the number-average molecular weight of 000g/mol.In addition, biodegradable second polyhydroxyalkanoatefrom has fusing point Tm2, than the fusing point Tm1 height of biodegradable first polyhydroxyalkanoatefrom at least about 20 ℃, thereby satisfy formula Tm2＞Tm1+20 ℃.Melting point values is generally measured by DSC (dsc), uses the method for describing among the ASTM D 3418 for example, adds in the heat scan temperature with the highest decalescence point that observes as this melting point values at DSC.Be not bound by theory, it is believed that if reach suitable blend composition, structure and high-caliber dispersion, biodegradable second polyhydroxyalkanoatefrom can be used as the nucleator of biodegradable first polyhydroxyalkanoatefrom, and improves the crystallization rate of described first multipolymer thus.

If use second polyhydroxy alkanoate copolymer as stated above, most of PHA composition comprises the first biodegradable polyhydroxy alkanoate copolymer, the second biodegradable PHA is dispersed in the external phase or matrix of first multipolymer subtly thus, and comprised, thereby improve the crystallization rate and/or the physical properties of first multipolymer with q.s.In one embodiment, composition comprises and counts about 0.01% to about 10% second pha copolymer by the gross weight of a PHA and second pha copolymer.In embodiment more specifically, composition comprises about by weight 0.1% to about 5% the 2nd PHA component.In addition more particular embodiment in, composition comprises about by weight 0.1% to about 3% second pha copolymer.

Biodegradable polyhydroxy alkanoate copolymer can be synthetic by disclosed chemistry or biological method, for example, is disclosed in United States Patent (USP) 5,618,855,5,942,597,5,990,271, RE36,548 or 6,160,199, each patent is incorporated herein by reference.

Multipolymer can be used as external phase and is present in the composition.Composition can comprise the combination of polyhydroxy alkanoate copolymer, or the combination of itself and other polymeric constituent, for example combination of additional polyester components etc.

Polyhydroxy alkanoate copolymer has fabulous avidity to solid particles surface such as starch, therefore allows this class particle directly to disperse when producing air-permeating film.Pha copolymer can be stretched and not produce macroscopic view and tear.

Typically, by the weight of the film of no softening agent, polyhydroxy alkanoate copolymer amount in blend of the present invention is greater than 25% to 99%, is preferably 30% to 95%, more preferably is 40% to 90%, and is most preferably 50% to 80%.

Typically, by the weight of the film that softening agent is arranged, the amount of polyhydroxy alkanoate copolymer in blend is 15% to 99%, is preferably 30% to 90%, more preferably is 40% to 80%, and is most preferably 50% to 70%.

Modified starch

The present invention relates to the i.e. use of naturally occurring polymkeric substance cheaply of starch.Because native starch generally has grainy texture, therefore need before melt-processed, carry out sex change.Usually, starch is by being dissolved in sex change in the water.Term " thermoplastic starch " is meant the starch with the softening agent sex change.

Suitable naturally occurring starch can comprise, but be not limited to W-Gum, yam starch, sweet potato starch, wheat starch, sago palm starch, cassava starch, Starch rice, soybean starch, arrowroot starch, bracken starch, Rhizoma Nelumbinis starch, tapioca (flour), waxy corn starch, amylomaize starch and commercial amylose starch.Also can use the mixture of starch.Although all starch can be used for the present invention, the native starch that the most normal employing of the present invention is obtained by agricultural raw material, it has supply and enriches, is easy to replenish and cheap advantage.Naturally occurring starch, especially W-Gum, wheat starch and waxy corn starch are because their economy and practicality are preferred starch polymers.

The starch of modification is modified starch, also can use.The starch of modification is defined as non-replacement or the substituted starch (that is, molecular weight changes the change of still starch not being made other necessity) that original molecular weight characteristic changes.Use treated starch if desired, the chemical modification of starch typically comprises acidity or alkaline hydrolysis, or the oxidative cleavage effect reduces molecular weight or molecular weight distribution.Starch natural, that do not have modification generally has very high molecular-weight average and wide molecular weight distribution (for example, the native corn starch molecular-weight average is up to about 60,000,000 gram/mole).(for example degrade by acid reduction, redox, enzyme reduction, hydrolysis (acidity or base catalysis), physical/mechanical, hot mechanical energy input by processing units), or they are used in combination, and the molecular-weight average of starch can be reduced to the scope of wanting required for the present invention.When carried out at the scene on the spot, thermomechanical method and method for oxidation provided extra advantage.As long as molecular-weight average is in an acceptable scope, chemical nature that starch is definite and molecular weight reduction method are not very important.The starch in the adding melts or the molecular weight ranges of starch mixture are that about 3,000 gram/moles are to about 10,000,000 gram/moles, be preferably about 10,000 gram/moles to about 2,000,000 gram/mole, more preferably be that about 20,000 gram/moles are to about 1,000,000 gram/mole.

About pectisation, starch can be in sex change in the presence of the solvent, solvent at this as softening agent.Solvent and starch mixture typically heat under pressurized conditions, and shear the process of accelerate gelation.Chemical reagent or enzyme agent also can be used to make starch denaturalization, for example by oxidation or derivatization.

Substituted starch also is a modified starch, although do not need, also can use.If expect substituted starch, the chemical modification of starch typically comprises etherification or esterification.Using substituted starch is for better consistency or miscibility are arranged with pha copolymer.Yet this must balance each other with the reduction of their degradation rates.The replacement degree of the starch that replaces with chemical process is about 0.01 to 3.0, lower replacement degree, and 0.01 to 0.06, perhaps be preferred.

Typically, by the weight of the starch of no softening agent, the amount of the modified starch part in the blend composition is about 1% to 75%, is preferably about 5% to 70%, more preferably is about 10% to about 60%, and is most preferably about 20% to about 50%.

Typically, by the film weight that softening agent is arranged, the amount of modified starch part is 1% to 85% in the blend composition, is preferably 10% to 80%, more preferably is 20% to 70%, and is most preferably 30% to 60%.

The weight of starch comprises starch and naturally occurring bound water content in composition.Term " irreducible water " is meant starch and other component are mixed and made into the naturally occurring water of finding before the composition among the present invention in starch.Term " free-water " is meant the water of composition that is used for making the present invention of adding.In case those of ordinary skill in the art can find that according to present disclosure component sneaks into composition, water just no longer can be distinguished out by its source again.By the weight of starch, the amount that starch typically contains irreducible water is about 5% to 16%.As everyone knows, extra free-water can be used as polar solvent or softening agent mixes, and is not counted in the weight of starch.

Can be used for example starch of the present invention has StarDri 100, and StaDex 10, and StaDex 15 or StaDex 65 are all from Staley company.StaDex 10 and StaDex 15 come the dextrin of the white of dent corn starch from the beginning.These dextrin have lower solvability in cold water, in the full-bodied bonding application facet of needs as tackiness agent.StaDex 65 also is the white dextrin from dent corn starch, and medium solvability is arranged in cold water, can be in the bonding application facet of the high viscosity of the medium solids content of needs as tackiness agent.The StarDri material is many dextrin of sex change in advance, typically is used for food applications.

Other composition

The thermoplastic polymer of the degraded by environment fully compatible with PHA and starch can be included in film of the present invention or the laminating material.So-called " compatible substantially " is meant when softening temperature that is heated to above composition and/or temperature of fusion, and polymkeric substance is possible to mix the substantially uniform mixture of formation with PHA and starch under shearing or expansion.In addition, the inclusion in the compatible polymeric should not reduce the performance of starch and PHA blend basically.Thermoplastic polymkeric substance must can flow when being heated to the machinable melts of formation, and can solidify again after generation crystallization or vitrifying.

Polymkeric substance must have fully low temperature of fusion to prevent the obvious degradation in the course of processing, and still enough again height make in film or the laminating material use has thermostability.The suitable temperature of fusion of biodegradable polymers is about 80 ℃ to about 230 ℃, and is preferably about 90 ℃ to about 200 ℃.Polymkeric substance must have and is suitable for film forming rheological properties.

Be applicable to that the non-limiting example at biodegradable thermoplastic polymer of the present invention comprises aliphatic poly esteramides, diprotic acid/dibasic alcohol aliphatic polyester; The modified aromatic adoption ester of polybutylene terephthalate that comprises polyethylene terephthalate, the modification of modification; Aliphatic/aromatic copolyesters, polycaprolactone comprise poly-(3-butyric ester), poly-(3-hydroxy alkane acid ester), poly-(3-hydroxycaproic ester) and poly-(3-hydroxyl valerate); The polyester and the urethane that obtain by aliphatic polyol (for example, dialkyl group alkoxide polymer); Polymeric amide comprises the polyethylene/vinyl alcohol copolymer; Lactic acid polymer comprises lactic acid homopolymer and lactic acid copolymer; Lactide polymer comprises lactide homopolymers and lactide copolymer; Co-glycolide polymers comprises glycollide homopolymer and glycolide copolymer, and their mixture.

Be suitable for also have polyvinyl alcohol and its multipolymer of the present invention.

Preferred temperature of fusion is 160 ℃ of extremely about 175 ℃ poly(lactic acid) homopolymer or multipolymers.The thermoplastic polymer of degraded by environment must be able at a good pace solidify, and preferably the flowing down of expansion, and then forms heat-staple membrane structure, as typically running in as injection molding or blown film extrusion method in known working method.

The specific embodiment that is applicable to preferred lactic acid polymer of the present invention or lactide polymer includes but not limited to those poly(lactic acid)-based polyalcohols or polylactide-based polyalcohol, and they are commonly referred to as " PLA " in industry.Therefore, term " poly(lactic acid) ", " polylactide " and " PLA " replaceable use, the homopolymer or the multipolymer that comprise lactic acid or rac-Lactide, the polymer property of the polymkeric substance that this forms based on the polymkeric substance that is formed by certain monomers or minimum repeated monomer unit.But, should be appreciated that term " poly(lactic acid) ", " polylactide " and " PLA " are not represented the generation type of limit polymerization thing.The embodiment of commercially available polylactic acid polymer comprises various available from Chronopol Inc. (Golden, poly(lactic acid) CO), or with trade(brand)name EcoPLA ^The polylactide of selling.Other embodiment of the commercially available poly(lactic acid) that is fit to comprises NATUREWORKS available from Cargilll Dow, available from the LACEA of Mitsui Chemical, or available from BiomerPLA resin L5000.

Depend on used concrete polymkeric substance, working method and film or the end-use of laminating material, may be more than a kind of polymkeric substance.Preferably use two kinds of different polyester.For example, if use have temperature of fusion for about 160 ℃ to about 175 ℃ crystallizable poly(lactic acid), just can use than other poly(lactic acid) to have than low melting point with than low-crystallinity and/or than second poly(lactic acid) of high copolymer content.Alternatively, the aliphatics aromatic polyester can use with crystallizable poly(lactic acid).Two kinds of polymkeric substance if desired, polymkeric substance only need distinguish by chemical stereospecificity or by molecular weight.

In one aspect of the invention, may need to use second-order transition temperature to be lower than 0 ℃ biodegradable thermoplastic polymer.Polymkeric substance with so low second-order transition temperature comprises EASTAR BIO and BIONELLE.

Softening agent can be used for the present invention and takes modified starch and starch can be flowed, and promptly produces thermoplastic starch.Identical softening agent or two kinds of independent softening agent can be used for increasing melt processable.Softening agent also can improve the snappiness of the finished product, it is believed that it is because softening agent can reduce the second-order transition temperature of composition that snappiness is improved.Softening agent should be preferably fully compatible with polymeric component of the present invention, and softening agent may change the character of composition effectively like this.Among the present invention, term " compatible substantially " is meant that when softening temperature that is heated to above composition and/or temperature of fusion softening agent energy and starch form full and uniform mixture.

The extra softening agent or the thinner that are used for biodegradable thermoplastic polymer can exist, with the temperature of fusion of reduction polymkeric substance and the consistency of improvement and thermoplastic starch blend integral body.In addition, if there be softening agent or the thinner that suppresses the polymer melted temperature, having more, the biodegradable thermoplastic polymer of high melting temperature can be used.Softening agent typically has the molecular weight that is lower than about 100,000 gram/moles, may be preferably block or random copolymers or terpolymer, and so one or more chemical species and another softening agent, starch, polymkeric substance or their mixture are compatible.

The non-restrictive example of useful hydroxyl softening agent comprises sugar for example glucose, sucrose, fructose, raffinose, maltodextrose, semi-lactosi, wood sugar, maltose, lactose, seminose, erythrose, glycerine and tetramethylolmethane; Sugar alcohol is tetrahydroxybutane, Xylitol, maltose alcohol, mannitol and sorbyl alcohol for example; Polyvalent alcohol is ethylene glycol, propylene glycol, dipropylene glycol, butyleneglycol, hexanetriol or the like for example, and their polymer and their mixture.Also can be used for hydroxyl softening agent of the present invention poloxomers and poloxamines are arranged.Also being applicable to of the present invention is the organic compound that does not have hydroxyl that forms hydrogen bond, comprises the derivative of urea and urea; The acid anhydrides of sugar alcohol such as the acid anhydrides of sorbitan; Animal protein is gelatin for example; The vegetable egg white matter is sunflower protein, soy-protein, cotton seed protein for example; And their mixture.Other suitable manufacturing methods has phthalic ester, Succinic acid dimethylester and diethyl ester and relevant ester, triacetin, glycerine list and diacetic acid esters, glycerine list, two and tripropionate, butyric ester, stearate, lactate, citrate, adipic acid ester, stearate, oleic acid ester and other biodegradable precursor (father) acid esters.Aliphatic acid such as ethylene acrylic, EMA, divinyl vinylformic acid, divinyl toxilic acid, acrylonitrile-acrylic acid, propylene toxilic acid and other hydrocarbon are the acid on basis.All softening agent can use separately or with its mixture.Low-molecular-weight softening agent is preferred.The molecular weight that is fit to is less than about 20,000g/mol, preferably less than about 5,000g/mol, be more preferably less than about 1,000g/mol.The softening agent that is more suitable for is at United States Patent (USP) 3,182, those that describe in 036 and 5,231,148.

Preferred plasticizer comprises glycerine, mannitol and sorbyl alcohol.The amount of softening agent depends on the amount of molecular weight and starch and the softening agent avidity to starch.Usually, the amount of softening agent increases along with the increase of starch molecule amount.Typically, the softening agent that exists in final film composite is about 2% to about 70%, more preferably is about 5% to about 55%, is most preferably about 10% to 50%.

Randomly, other composition can by composition weight count less than about 50%, preferred about 0.1% to about 20%, more preferably from about 0.1% mix in the composition to about 12% amount.Can use optional material to improve the physical properties of processibility and/or improvement the finished product, as elasticity, tensile strength and modulus.Other benefit includes, but not limited to comprise the stability, brightness, color of oxidative stability, flexible, screen resilience, workability, processing aid, viscosity modifier and smell control.

The indefiniteness embodiment of other optional member comprises aromatics/aliphatic polyester multipolymer; its easier hydrolytic cleavage; therefore be easier to biological degradation; as those at United States Patent (USP) 5; 053; 482; 5; 097; 004; 5; 097; 005 and 5; the multipolymer of describing in 295,985; biodegradable aliphatic polyester amide polymer; polycaprolactone; be derived from the polyester or the urethane (being the dioxane polymeric diacyl) of aliphatic polyol; the polymeric amide that comprises the polyethylene/vinyl alcohol copolymer; cellulose ester or its plastifying derivative; salt; slip(ping)agent; crystallization accelerator such as nucleator; the crystallization delayed-action activator; odor mask; linking agent; emulsifying agent; tensio-active agent; cyclodextrin; lubricant; other processing aid; white dyes; antioxidant; fire retardant; dyestuff; pigment; weighting agent; protein and their basic salt; wax; the clayization resin; filler; anti-hard caking agent; static inhibitor; or their mixture.Can use slip(ping)agent to reduce the interior bonding or frictional coefficient of film.And, also can use slip(ping)agent to improve the stability of film, especially under high humidity or high-temperature condition.The slip(ping)agent that is fit to has polyethylene.Also can in melt, add salt and make film, or salt is used as processing aid the easier response of water.The solubleness that salt also helps to reduce tackiness agent is not dissolved it, but when they put into water or flushing, salt will dissolve, and impels the tackiness agent dissolving, thereby obtains the product to the easier response of water.

The making of gas permeable film comprises that the extension of pha copolymer/starch film stretches.Starch provides nucleator for the stretched operation that forms aperture, therefore as particles filled dose.Yet particles filled dose or grain pigment can be added in pha copolymer/starch air-permeating film composition.These weighting agents comprise polytype inorganic or organic solid, as talcum, lime carbonate, mica, potter's clay, plasticising ball, latex etc.The other weighting agent of inorganic filler such as magnesium, aluminium, silicon or titanyl compound; Hydrated magnesium silicate, titanium dioxide, clay, earth, chalk, boron nitride, Wingdale, diatomite, glass, quartz or pottery.If exist, particles filled dose on the use basis of special composition and air-permeating film typically the amount with about 1% to about 50% exist.

According to disclosure of the present invention, other embodiment of other composition knows for the person of ordinary skill of the art.

Although starch is preferred natural polymer among the present invention, also can adopt based on proteinic polymkeric substance.Suitable comprises soybean protein, zein based on proteinic polymkeric substance, or their mixture.Based on proteinic polymkeric substance can about 0.1% to about 80%, 1% to about 60% the amount of being preferably about exists.

(2) The performance of film or laminating material

The present invention adopts the form of film or laminating material, and these formal descriptions are in United States Patent (USP) 5,498, in 692, and uses blend of the present invention or lamination composition.Among the present invention, so-called " blend " is meant the composition (that is, PHA and modified starch) of two or more compositions.Among the present invention, so-called " film " is meant to have high length and thickness ratio and the high width and the continuous slice as thin as a wafer of thickness ratio.Though the accurate upper-bound to thickness does not require, preferred upper limit is about 0.254mm, more preferably from about 0.01mm even 0.005mm more preferably from about.The protection of any film is worth the continuity that depends on it, does not promptly have hole or crack.Air-permeating film has been stretched and has produced the continuous aperture that prevents liquid infiltration but can see through moisture.Air-permeating film can be one deck of multilayer film.Film can be multilayer film, that is, and and laminating material or matrix material.Laminating material is meant the two-layer or multilayer film that link together.Laminating material can have one or more layers pha copolymer/starch composites that comprises the blend that the present invention proposes.In another embodiment, laminating material can have the first layer of the pha copolymer that comprises that the present invention describes and comprise pha copolymer/starch film that the present invention proposes or the second layer of thermoplastic starch.Laminating material can have the first layer that comprises pha copolymer, and comprise the second layer of PHA/ starch blend or thermoplastic starch and comprise the 3rd layer of PHA, or the mixing of any conceivable layer.Terminology used here the first layer, the second layer or the 3rd layer only are used to describe different layers, and do not mean that the position of limiting layer.The preferred embodiment of the invention is that trilaminar laminating material is arranged, Wai Mian the two-layer pha copolymer that comprises wherein, and the middle layer comprises pha copolymer/starch blend or thermoplastic starch.

Film of the present invention can be used for multiple disposable product, including, but not limited to, disposable diaper, shrink packaging are (for example, food product pack, consumer products packing, tray and/or crate packing, or the like) or sack (groceries bag, Food preservation bag, sandwich bag, reclosable " Ziploc ^" type bag, refuse bag, or the like).In one embodiment of the invention, film is a kind of egative film or porose top flat of liquid non-permeate, is suitable as absorbable disposable sanitary articles, for example disposable diaper, feminine hygiene products etc.Except improving biodegradable and/or compostability, film of the present invention also has United States Patent (USP) 5,990, the characteristic that proposes in 271.

Film or laminating material that the present invention produces are degraded by environment.So-called " degraded by environment " is meant biodegradable, disintegratable, " to water sensitive ", dispersible, flushable or compost or their combination.In the present invention, film, multilayer film (laminating material) and goods are degraded by environment.Therefore, film and laminating material can be handled in existing compost facility easily and safely, or pour the waterways safely, and can not produce baleful consequences to existing water drain infrastructure system.The degraded by environment of film of the present invention or laminating material provides solution for these materials use the accumulation of back in environment in disposable product.The flushable property of film of the present invention when being used for disposable products such as cleaning piece and women sanitary articles provides extra convenient and dispersed for the human consumer.Although biological degradability, slaking, " to water sensitivity ", dispersibility, stackable property and flushable property all have different standards, and by different experimental measurements, usually, film among the present invention or laminating material will satisfy more than more than one these standards.

" biodegradable " is meant, when material is exposed in aerobic and/or the oxygen-free environment, finally decays to monomer component owing to microorganism, hydrolytic action and/or chemical action.Under aerobic conditions, biological degradation makes material be converted into final product such as carbonic acid gas and water.Under oxygen free condition, biological degradation makes product be converted into carbonic acid gas, water and methane.Biodegradation method is commonly called mineralising." biological degradability " is meant that all organic constituents of film finally all decompose by biological activity.

A plurality of tissues have been formulated multiple different standardized biological degradability method with country variant.Though the test under concrete test condition, testing method and required testing standard is different, and rational consistence is arranged between different testing schemes, makes them can obtain similar conclusion to most of materials.For the aerobic bioreactor degradation property, U.S.'s test has been formulated ASTM D 5338-92 testing method with materials association (ASTM): the testing method of measuring the aerobic bioreactor degradation property of plastic material under in check composting conditions.This tests the per-cent of measuring the test material that is subjected to mineralising that has functional relation with the time by the burst size of monitoring carbonic acid gas 58 ℃ of thermophilic temperature down, and the carbonic acid gas that is discharged is that the assimilation absorption owing to microorganism produces in the presence of active compost.The CO 2 test can be carried out via the electrolysis respirometry.Also can use other standard scheme, as the 301B of the Organization for Economic Cooperation and Development (OECD) formulation.At the standard biological Degradation test description under the anaerobic situation in various testing schemes, as ASTM D 5511-94.These testing schemes are used for simulating the biological degradation at anaerobic solid refuse treatment facility or sanitary landfill method material.

Film of the present invention or laminating material can fast degraded biologicallies.Quantitatively, described degraded is meant the per-cent of the material that is converted into carbonic acid gas after preset time.Also disintegration may take place.Disintegration is meant, when film or laminating material have the ability of quick fragmentation, and disintegration is small shreds, and described fragment is enough little so that can not distinguish after compost sieves, and can not cause when flushing that perhaps water shoot stops up.The material of disintegratable is also flushable.Most of slaking testing schemes have been measured measured material and have been exposed to the weight loss of various matrix after for some time.Aerobic and anaerobic disintegration test can be used.Weight loss is after material is exposed to waste water and mud, by what no longer determined by the amount of the test material of 18 mesh sieves in 1mm hole collection.For disintegration, the difference between the dry weight of the sample of recovering on the weight of initial sample and the screen cloth will determine the speed and the degree of disintegration.Because these testing schemes use identical environment basically, so be similar to the test of slaking for biological degradability.For determining slaking, need to measure the weight of surplus material; And, then need to measure the gas of separating out in order to determine biological degradability.

Film of the present invention or laminating material also are composts.ASTM has developed about the testing method of compost and standard.Three features of this thermometrically: biological degradability, slaking and do not have eco-toxicity.The testing method of measuring biological degradability and slaking has been described above.For satisfying the biological degradation standard of compost, material must reach the carbon dioxide conversion at least about 60% in 40 days.For the slaking standard, must there be test material to remain on the 2mm screen cloth less than 10%, retained material has the true shape and the thickness of processed product.For determining the last item standard-no eco-toxicity, the by product of biological degradation must not have disadvantageous effect to seed germination and plant-growth.A test of this standard is specified among the OECD 208.Reach ASTM 6400-99 specification in case product is verified, so international biodegradable product association (The InternationalBiodegradable Products Institute) will issue the compostability sign.Testing scheme is followed the DIN 54900 of Germany, and it has measured the material of decomposition is finished in any permission in a compost circulation maximum ga(u)ge.

Film of the present invention can be heat bonding.Heat bondable film is that the bonding and ventilative heat bonding method of pressurized heat is necessary.Film also can be lamination or heat-sealing.The polymkeric substance that fusing point is lower is that heat seal process is required.Can preferred multiple material, to reach best heat seal condition.Comprise the film of PHA and starch blending or comprise that the pha copolymer/laminating material of starch blend layer can improve the bonding characteristic of film.

(3) Make the method for film or laminating material

The film and the laminating material that have enhanced degraded by environment and/or compost among the present invention can use the program processing of conventional production individual layer or multilayer film on conventional equipment for making film.Modified starch mixes the heat treatable composition of generation with the hemicrystalline polyhydroxy alkanoate copolymer of ductility.The bead of PHA/ starch blend of the present invention can pass through at first dry mixed, and melting mixing is made in the film forcing machine then.Alternatively, if in the film forcing machine undercompounding, bead is dry mixed at first, melting mixing in the pre-mixing forcing machine is then granulated again again, then carries out film and extrudes.

Need relative low processing temperature that the thermolysis of starch is minimized with the common processing of starch.PHA melts being lower than under 150 ℃ the temperature, so the thermolysis of starch is minimized.

PHA/ starch blend of the present invention can use injection moulding or blown film extrusion method melt-processed to become film, and these two kinds of methods have description in " plastics extruding technology " second edition (Plastics Extrusion Technology-2nd Ed.) that Allan A.Griff (Van Nostrand Reinhold-1976) compiles.The injection moulding film is extruded from the linear slot mould.Usually plain net cools off on large-scale mobile polishing metal roll.Its very fast cooling is peeled off from first roll, through one or more auxiliary cooling roll, coats traction rollers or " retreatment " roll of rubber then by a cover, finally arrives the roll film wrapping head.

In blown film was extruded, melt was upwards extruded by thin ring mould opening.This method is also referred to as tubular film and extrudes.By the central introducing air of mould, thereby also to make it to expand to the pipe inflation.Thereby the formation moving bubble, by the control internal air pressure size of moving bubble is remained unchanged.The film tube air cooling, air blows out from the one or more air rings around pipe.Then with the pair of traction rollers traction pipe formation flat structure that makes it to cave in, and with it around to wrapping head.When film is applied to egative film, can launch, and further be cut into the width that is applicable to product then with flat tubular film cutting opening.

Injection moulding film and blown film process may be used to produce individual layer or multilayer film structure.For for single thermoplastic material or thermoplastic component blend manufacture order layer film, only need to use single forcing machine and single manifold mould.

For the production of multilayer film of the present invention or laminating material, preferably use the coextrusion method.These methods need be more than one forcing machine, and coextrusion feed sleeve pipe or branch manifold mold system or both combinations, to obtain multilayer film structure.

United States Patent (USP): 4,152,387 and 4,197,069 discloses the feed principle of coextrusion.A plurality of forcing machines and feed are telescopic joint, and the relation that described feed sleeve pipe uses removable flow insulated wall to be directly proportional according to the volume with the polymkeric substance that passes through described fluid channel changes the geometric position of each fluid channel.The fluid channel is designed to: at the point of material, after eliminating interfacial stress and flow instability, material converges to together with identical speed and pressure.In case material converges in the feed sleeve pipe, they just flow in the single manifold mould as the fluid of composite structure.Importantly, melt viscosity between the material and melt temperature differ and are not big especially in these technologies; Otherwise flow instability can cause the layer thickness profile in the wayward multilayer film of mould.

The coextrusion of alternative feed sleeve pipe be branch manifold mould or blade mold, as above-mentioned United States Patent (USP): 4,152,387,4,197,069 and United States Patent (USP) 4,533,308 in disclosed.Although melt-flow is externally converged before entering die body in the feed cannula system, in branch manifold mould or blade mold, each melt-flow has its manifold in mould, wherein polymkeric substance independent diffusion in its manifold separately.Each melt-flow near mould outlet with die width combination completely.Removable blade can provide the controllability of each fluid channel outlet, it is directly proportional with the volume of material that exports by the fluid road, thereby melt is flow to together with identical linear velocity, pressure and required width.

Because the melt flow property and the melt temperature of institute's processing materials may alter a great deal, therefore use blade mold just to have several advantages.Self has insulating characteristics mould, and wherein the material that differs greatly of fusing point for example differs up to the material of 175  (80 ℃) and can process together.

Each manifold can be designed and regulate to be used for specific polymkeric substance (or multipolymer) in the blade mold.Thereby the influence of the manifold design that the flowing of every kind of polymkeric substance only is subjected to it, and be not subjected to the influence of the power that other polymkeric substance applies.This material that makes melt viscosity fall far short can coextrusion form multilayer film.In addition, blade mold can also be regulated single manifold width, makes internal layer, and for example water-soluble biodegradable polymkeric substance such as Vinex 2034 can be surrounded by the water-insoluble material fully, can not stay the exposed edge edge that is subject to the water influence.Above-mentioned patent also discloses being used in combination of feed cannula system and blade mold, thereby obtains more complex multilayered structures.

Multilayer film of the present invention can comprise two-layer or more multi-layered.Usually, preferred equilibrated or symmetric three layers and five layer films.Equilibrated three layer multi-layer films comprise intermediate core layer and two identical skins, and wherein said intermediate core layer is between described two skins.Equilibrated five layer films comprise intermediate core layer, two identical tack coats and two identical skins, and wherein said intermediate core layer is between described two tack coats, and each tack coat is between described sandwich layer and each skin.Though the balance film is optional for film of the present invention, they curl or distortion than non-equilibrium film is more difficult.

In three-layer thin-film, intermediate core layer can comprise 10% to 80% of overall film thickness, and each skin comprises 10% to 50% of overall film thickness.When using tack coat, each tack coat comprises about 5% to about 10% of overall film thickness.

Air-permeating film is made by the extension oriented film.Can run through film and carry out the homogeneous stretching, for example, by " plastics film " (Plastics Films) second edition that J.H Briston publishes at New York Longman Inc. (1983), the stretching of in the tenter stentering, implementing of the 83rd to 85 page of description.Alternatively, can run through film and carry out the incremental stretching, for example in the operation of ring-roller, as United States Patent (USP) 4,116,892 and 5,296,184 is described such, wherein replaces parallel stretch zones and keep the regional coexistence of tensile of reality.Oriented film causes that adherent local mechanical destroys between starch and polymeric matrix.This destruction produces empty structure around the starch, causes passing the formation of the continuous aperture of film.The aperture is for enough little, thereby the feasible unbalanced big capillary force that causes owing to minimum radius-of-curvature can stop liquid to penetrate.Therefore, liquid is held safely by porous-film.Because the transportation of moisture is not subjected to the obstruction of capillary force, therefore aperture can transmit moisture continuously.Be the control that obtains aperture is formed, starch is dispersed in the film matrix before stretched operation equably and subtly.PHA or PHA/ starch blend can be stretched among the present invention, do not have macroscopical tear.

(4) Disposable products

The invention still further relates to the disposable product that comprises PHA/ starch blend of the present invention or laminating material.For example, stackable absorbent article comprises liquid permeable topsheet, comprises the film of the present invention liquid-tight egative film of (for example, comprising the film of PHA/ starch blend among the present invention), and the absorbent core between top flat and egative film.This class absorbent article comprises baby diaper, adult-incontinence briefs and protection pad and woman's sanitarg mapkin and liner.The disposable personal care product comprises ventilative product, but this product receiving fluids allows to see through some moisture simultaneously.

The additional product that comprises PHA/ starch blend of the present invention or laminating material comprises the personal cleansing wipe thing; Disposable hygienic health-care product such as bandage, wound dressings, wound is cleaned pad, operating coat, surgical mask, operation pad; The disposable product such as the clothes of other social public organizations and health care, cleaning piece, liner, bed clothes product such as coverlet and Pillow cases, and foam pad mattress.

Film of the present invention or laminating material are when the egative film of the liquid non-permeate that is used as absorbent article of the present invention such as disposable diaper, and its thickness typically is 0.01mm to about 0.2mm, and preferred 0.012mm is to about 0.051mm.

Other embodiment of absorbent article of the present invention comprises the sanitary towel that is used for receiving and holding vagina movement such as menstruation.The effect that disposable sanitary napkin is designed to by clothing such as underwear or trousers or specially designed belt remains near the human body.The embodiment that is easy to be suitable for this type of sanitary towel of the present invention is disclosed in the United States Patent (USP) 4,589,876 in United States Patent (USP) on May 20th, 4,687,478 and 1986 on August 18th, 1987.Obviously, comprise among the present invention that the film of PHA/ starch blend or laminating material of the present invention can be as the egative films of liquid non-permeate in this class sanitary towel.On the other hand, should be appreciated that the present invention is not limited to any concrete sanitary towel configuration or structure.

Importantly, absorbent article of the present invention is than using the conventional absorbent article such as polyolefine material (for example, polyethylene egative film) having biodegradable and/or compostability to a greater extent.

Embodiment 1

Present embodiment demonstration comprises the processing of binary blend of the modified starch of preferred polyhydroxy alkanoate copolymer and unplasticised mistake.Specifically, comprise the polyhydroxy alkanoate copolymer of 3-hydroxycaproic ester (hereinafter representing) of 3-butyric ester and about 12 molar percentages and the mixture of modified starch, utilize injection moulding film extrusion method melt-processed to become film with the PHBH multipolymer.StarDri 1 and PHBH are in 150 ℃ of blend and thoroughly mixing.There is not the starch softening agent to exist.On the basis of PHBH and starch equivalent weight dry weight, the content of PHBH is that 10 to 90 weight percents do not wait.It is found that for being formed with the film of usefulness, the content of PHBH need be on 25 weight percents.

Embodiment 2

Present embodiment demonstration comprises the processing of binary blend of sex change (thermoplasticity) starch of preferred polyhydroxy alkanoate copolymer and plasticising.Specifically, comprise the polyhydroxy alkanoate copolymer of 3-hydroxycaproic ester (hereinafter representing) of 3-butyric ester and about 12 molar percentages and the mixture of thermoplastic starch, utilize injection moulding film extrusion method melt-processed to become film with the PHBH multipolymer.StarDri 1/ sorbyl alcohol of 70/30 blend and PHBH are in 150 ℃ of blend and thoroughly mixing.On the basis of PHBH and starch equivalent weight dry weight, the content of PHBH is that 10 to 100 weight percents do not wait.It is found that for being formed with the within reason sticking film of usefulness, the content of PHBH need be on 15 weight percents.Film can present embodiment in whole ratio manufacturings.

Embodiment 3-32

The processing of present embodiment demonstration double-layer lamination film.The PHBH polymkeric substance of describing in embodiment 1 is as the first layer.The PHBH/ thermoplastic starch blend of describing in embodiment 2 is as the second layer.Laminating material utilizes the manufacturing of coextrusion method according to following form:

Embodiment #	The first layer	The second layer	The second layer	Form
						(％)	(％)	(％PHBH)	(% starch)
3	10	90	0	100
					4	10	90	10	90
5	10	90	25	75
					6	10	90	50	50
7	10	90	75	25
					8	10	90	90	10
9	25	75	0	100
					10	25	75	10	90
11	25	75	25	75
					12	25	75	50	50
13	25	75	75	25
					14	25	75	90	10
15	50	50	0	100
					16	50	50	10	90
17	50	50	25	75
					18	50	50	50	50
19	50	50	75	25
					20	50	50	90	10
21	75	25	0	100
					22	75	25	10	90
23	75	25	25	75
					24	75	25	50	50
25	75	25	75	25
					26	75	25	90	10
27	90	10	0	100

28	90	10	10	90
					29	90	10	25	75
30	90	10	50	50
					31	90	10	75	25
32	90	10	90	10

Embodiment 33

Present embodiment three processing of ironed film layer by layer of having demonstrated, (the first and the 3rd) layer uses the PHBH multipolymer among embodiment 1 outside, or alternatively uses at middle (second) layer.When the PHBH multipolymer was skin, the PHA/ thermoplastic starch blend in embodiment 2 was used in the middle layer, in this embodiment, starch can account for blend up to about 90%.In this embodiment, in the mixture starch part up to 50%.Utilize coextrusion method manufacturing three press mold layer by layer, according to:

Embodiment #	The first layer	The second layer	The second layer	Form	The 3rd layer
							(％)	(％)	(％PHBH)	(% starch)	(％)
34	10	80	0	100	10
						35	10	80	10	90	10
36	10	80	25	75	10
						37	10	80	50	50	10
38	10	80	75	25	10
						39	10	80	90	10	10
40	25	50	0	100	25
						41	25	50	10	90	25
42	25	50	25	75	25
						43	25	50	50	50	25
44	25	50	75	25	25
						45	25	50	90	10	25
46	50	50	0	100	10
						47	50	40	10	90	10
48	50	40	25	75	10
						49	50	40	50	50	10
50	50	40	75	25	10

51	50	40	90	10	10
						52	50	25	0	100	25
53	50	25	10	90	25
						54	50	25	25	75	25
55	50	25	50	50	25
						56	50	25	75	25	25
57	50	25	90	10	25
						58	45	10	0	100	45
59	45	10	10	90	45
						60	45	10	25	75	45
61	45	10	50	50	45
						62	45	10	75	25	45
63	45	10	90	10	45

Embodiment 64

Every square metre 100 gram, the PHBH resin/starch injection moulding film of the lime carbonate filling of volume percent 27.5% is biaxially oriented, and the assessment vapor transmission rate.Each sample stretches 400% and continue 5 seconds on machine direction.Processing stretching sample 0%, 50%, 100%, 150%, 250% and 400% on the vertical direction then.Each sample kept 5 seconds at stretch position.The vapor transmission rate of specimen then.Expectation only has relatively low vapor transmission rate at the film of machine direction stretch.Along with the increase of amount of tension on the processing vertical direction, the vapor transmission rate of oriented film will increase to the value of manyfold (promptly 4 to 30 times) than non-stretched film.

All patents of mentioning in this manual, patent application (with any patent at its announcement, and asking in the foreign patent of any corresponding publication) and the disclosure of publication all are incorporated herein by reference.Yet, clearly do not admit to introduce the present invention and lecture or disclose the present invention with any file for referencial use.

Though illustrated and described specific embodiments of the present invention, but it is evident that for those of ordinary skill in the art, according to disclosure of the present invention, under the situation that does not break away from the spirit and scope of the present invention, can carry out various other changes and modification to it.Therefore appending claims is intended to comprise that all these belong to change and modification within the scope of the present invention.

Claims (21)

1. composition, described composition comprises:

Modified starch; With

Comprise at least two kinds of unitary polyhydroxy alkanoate copolymers of random repeated monomer

Wherein first monomeric unit has structure (I):

R wherein ¹Be H or C1 or C2 alkyl, and n is 1 or 2; With

Wherein second monomeric unit has structure (II)

R wherein ²Be C3-C19 alkyl or C3-C19 alkenyl,

Or described second monomeric unit has structure (III)

Wherein m is 2 to 9

Wherein said composition is a form of film.

2. composition as claimed in claim 1, wherein said polyhydroxy alkanoate copolymer comprise the 3rd random repeated monomer unit, and described monomeric unit has structure (IV)

R wherein ⁵Be H or C1-C19 alkyl or alkenyl, and s is 1 or 2, collateral condition is that described the 3rd monomer is different from described first or second monomer.

3. composition as claimed in claim 1, described composition also comprises second polyhydroxyalkanoatecopolymers copolymers or multipolymer.

4. composition as claimed in claim 1, the content of wherein said polyhydroxy alkanoate copolymer counts 25% to 99% by the weight of described film.

5. composition as claimed in claim 1, described composition also comprises softening agent, and the content of wherein said polyhydroxyalkanoate copolymer counts 15% to maximum 99% by the weight of described film.

6. composition as claimed in claim 4, wherein said contents of starch counts 1% to 75% by the weight of described film.

7. composition as claimed in claim 5, wherein said contents of starch counts 1% to 85% by the weight of described film.

8. sack, described sack comprises film as claimed in claim 1.

9. wrap, described wrap comprises film as claimed in claim 1.

10. absorbent article, described absorbent article comprises film as claimed in claim 1.

11. multi-layer laminated films, wherein one deck comprises composition as claimed in claim 1 at least.

12. multi-layer laminated films as claimed in claim 11, wherein the second layer is made up of pha copolymer.

13. multi-layer laminated films as claimed in claim 11, wherein said one deck at least is the middle layer, and described film also comprises two skins, and wherein said two skins are made up of pha copolymer.

14. multi-layer laminated films, described multi-layer laminated films has the one deck that comprises composition as claimed in claim 1 at least, and has one deck of being made up of the polyhydroxy alkanoate copolymer that comprises at least two random multiple monomeric units at least

Wherein first monomeric unit has structure (I)

R wherein ¹Be H or C1 or C2 alkyl, and n is 1 or 2; With

Wherein second monomeric unit has structure (II)

R wherein ²Be C3-C19 alkyl or C3-C19 alkenyl,

Or described second monomeric unit has structure (III)

Wherein m is 2 to 9.

15. composition as claimed in claim 1, described composition are the oriented film form with continuous hole, described continuous hole stops the infiltration of liquid and allows aqueous vapor to see through.

16. composition as claimed in claim 1, described composition also comprises the dispersed microparticles weighting agent, and described composition is the oriented film form with continuous hole, and described continuous hole stops the infiltration of liquid and allows aqueous vapor to see through.

17. laminated multi-layer thing as claimed in claim 11, wherein said one deck at least also comprises the dispersed particles weighting agent, the continuous hole that described layer is stretched and can stops liquid infiltration and allow aqueous vapor to see through to produce.

18. composition, described composition comprises:

Modified starch; With

Comprise at least two kinds of unitary polyhydroxy alkanoate copolymers of random repeated monomer

Wherein first monomeric unit has structure (I)

R wherein ¹Be H or C1 or C2 alkyl, and n is 1 or 2; With

Wherein second monomeric unit has structure (II)

R wherein ²Be C3-C19 alkyl or C3-C19 alkenyl,

Or described second monomeric unit has structure (III)

Wherein m is 2 to 9

Wherein said composition is the air-permeating film form.

19. a composition, it is by to modified starch and comprise that at least two kinds of unitary polyhydroxy alkanoate copolymers of random repeated monomer carry out common processing and produce,

Wherein first monomeric unit has structure (I)

R wherein ¹Be H or C1 or C2 alkyl, and n is 1 or 2; With

Wherein second monomeric unit has structure (II)

R wherein ²Be C3-C19 alkyl or C3-C19 alkenyl,

Or described second monomeric unit has structure (III)

Wherein m is 2 to 9.

20. reduce the method for environmental pollution, the goods that described method is included in the solid waste disposal facility or deposition comprises composition as claimed in claim 1 in the sanitary landfill, the biological degradation of wherein said goods is faster than the biodegradation rate of the goods that do not comprise described composition.

21. method as claimed in claim 20, wherein said solid waste disposal facility or sanitary landfill have the environment that carries out anaerobic degradation.