Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/0008—Organic ingredients according to more than one of the "one dot" groups of C08K5/01 - C08K5/59

Definitions

• the present invention relates to a biodegradable plastic compound for use in thermoplastic applications and to its method of manufacture, and in particular to biodegradable polymers including, but not limited to, polyvinylalcohol (PVA) and polyvinylalcohol/ polyvinylacetate copolymer, (PVA/PVAc).
• biodegradable polymers including, but not limited to, polyvinylalcohol (PVA) and polyvinylalcohol/ polyvinylacetate copolymer, (PVA/PVAc).
• PVA and PVA/PVAc copolymers are known biodegradable materials.
• PVA and PVA/PVAc (of greater than 85% PVA) are soluble in warm and hot water.
• PVA/PVAc (of less than 85% PVA content) is readily soluble in water at room temperature. Post dissolution these materials will bio-degrade on exposure to bacteria present in the environment. These polymers and their part degradation and degradation products are non- toxic and pose no risk of bio-accumulation or long term hazard to the environment.
• US-A-1, 040,506 discloses a process of manufacturing PVA film at 196-218°C, using mould lubricants as auxiliaries in amounts from 0.2-2%.
• US-A-3, 997,489 discloses the improvement of melt flow index (MFI) of plasticised PVA by the addition of 0.5-5 % by weight of wax or waxy materials and 0.5- 5% of polyethylene polymer or copolymers which enabled thermoplastic processing at 205-240°C. MFI data was determined at 210°C and 230°C.
• US-A-5,206,278 discloses extrudable compositions of plasticised PVA co-compounded with 5-95 weight % of polyethylene oxide (PEO) or PEO copolymers of average molecular weight 100,000- 500,000.
• US-A-5,349,000 Air products discloses plasticised PVA co-compounded with 8-25 weight % polyester-polyether block-copolymers, the compound being processed at 200°C.
• the Hoechst process described by Zimmermann and Harreus in EP-A-0004587 and US-A- 4,323,492, (Zimmermann et al) has claimed the improve plasticisation of PVA by specific particle size control of materials blended in a force action mixer prior to compounding or extrusion.
• the Hoechst process for the preparation of plasticised PVA film describing the aforementioned plasticisation process is further detailed by Harreus et al, Hoechst Resins Special Print 'Plastics films formed from poly vinyl alcohol' and discloses desired extrusion barrel temperatures of 215-225°C, die extrusion temperatures of 165-195°C, and operating pressures of 150-200 bar for the preparation of cold water soluble film.
• the PVA Plasticiser blend is described as 'not a free flowing process' with the material described as 'rubber elastic' in behaviour. Additional disclosure in Mowiol - Polyvinyl Alcohol, Hoechst Aktiendeschaft (1991) indicates die extrusion temperatures from 220- 150°C depending upon grade of Mowiol (PVA).
• Zimmerman et al in US-A-4,542,178 encompass co-compounded plasticised and unplasticised PVA, optionally with various starch, cellulose, gelatine or vinyl based fillers. Also Zimmermann et al in US-A-4,656,216/EP-A-0155606 have claimed a film of co-compounded PVA with N-vinyl-N-methylamide, which will retain its water dissolution characteristics on storage with acidic chemicals which would otherwise so degrade water soluble PVA as to render it insoluble. The material is processed at 200°C and extruded at 170°C at the die.
• US-A-4,469,837 (Cattaneo) describes a compound based on PVA, and polyol plasticisers such as Glycerol, Mannitol and Pentaerythriol with working extrusion temperatures from 190-220°C.
• polyol plasticisers such as Glycerol, Mannitol and Pentaerythriol with working extrusion temperatures from 190-220°C.
• US-A- 4,529,666 discloses similar materials based on one or more 1,4- monoanhydrohexitols and or one or more 1,4- 3,6-dianhydrohexitols, such as mono and di anhydro-sorbitols and mannitols. Plasticisation is carried out at 170-200°C and materials die extruded at 210-230°C.
• EP-A-0635545-A2 Air Products describes a process based on PVA, Glycerol and Pentaerythriol compounding at 195-225°C. This disclosure claims the addition of small amounts of mineral acids will improve the stability of PVA.
• US-A-3,886,112 discloses the working of plasticised PVA with 65- 98 weight % water and 0.5-5% borate salts.
• US-A- 5,322,866 discloses a process whereby PVA is co-compounded with starch and 13% w/w water and extruded wet (or semi -dry in the patent terminology), the product necessitating air curing to 5% water before use.
• WO93/09171/US-A-5,462,981 (Bastioli et al) discloses a process for the preparation of compound from PVA, plasticisers, starch, 0-7% urea and 5-40% water.
• Irish Patent No. S71912/WO 97/09379 discloses that PVA PVAc copolymer comprising 70-85% PVA and 30-15% PVA with molecular weights in the range 20,000 to 90,000 can be more efficiently plasticised by the addition of 3-15% weight equivalent glycerol with the aid of 4-6"% weight equivalent of stearamide or stearic acid salts as a 'stabiliser'.
• the mixing of components is carried out at 106-140°C and the material processed at 195-225°C into thermoplastic materials.
• the present invention seeks to provide an improved method of manufacturing an article or material using biodegradable polymers such as PVA/PVAc and to improved, biodegradable articles prepared using the method.
• the present invention provides a method of manufacturing a homogeneous biodegradable plastics compound, comprising mixing a polyhydroxylated polymer or copolymer with a plasticiser or a blend of plasticisers and a stabiliser or a blend of stabilisers, the stabiliser or blend thereof comprising a surface active agent, dispersing aid and or mould lubricant and thermoplastically processing the mixture at 120°C to 205°C, the thermoplastic processing including compounding the mixture at a temperature in the range of 140°C to 205°C, the resulting compound having a melt flow index of 0.2 to 375 g/10 minutes using 21.6Kg at 190°C (ISO 1133 method), the plasticiser and stabiliser or blends thereof rendering the mixture stable to thermoplastic processing, with the proviso that the stabiliser does not comprise stearamide or stearic acid salt when used singly as the stabiliser at a mixing temperature of 106°C to 140°C with polyvinylalcohol or polyvinylalcohol/
• the compounding temperature may be in the range of 140°C to 185°C in which case the biodegradability of the resulting compound is identical to that of the uncompounded mixture of its components.
• the biodegradability of the resulting compound is reduced by not more than 30% of that of the uncompounded mixture of its components.
• the polymer or copolymer may comprise polyvinylalcohol or polyvinylalcohol/ polyvinylacetate copolymer or a co-compound thereof selected from polyethylene, polystyrene, polyhydroxy butyrate, polyhydroxyvalerate, polycaprolactone or any polyhydroxylated polymer or any thermoplastically processable polymer.
• the polymer or copolymer may comprise any polyhydroxylated polymer.
• the blend of stabilisers acts as a super-plasticiser and is used to enhance the effectiveness of the plasticiser by rendering the molten plastic more fluid and easier to process than can be achieved using a single stabiliser.
• the plasticiser may be selected from any low-volatile or low melting alcohol, ester or ether, or any bi- or tri-functional alcohol, ester or ether or any combination thereof.
• the plasticiser preferably comprises any material selected from :-
• Glycerol propylene glycol, 1,3-propanediol, ethylene glycol; or
• citric acid (C, to C 4 ) alcohol tri-esters or mixed tri-esters or glycol esters or (C
• any vegetable base oils including soya oil or corn oil; or
• the stabiliser comprises any material selected from:-
• the plasticiser includes Triacetin. Glycerol mono-stearate as a stabiliser is also particularly useful.
• the stabiliser may also include a blend of stabilisers including a stearic acid salt and/or stearamide.
• the stabiliser comprises calcium stearate alone or in admixture with another stabiliser compound.
• Mixing may be carried out at a temperature of at least 55°C to form a plasticised compound which can be thermoplastically processed at a temperature of at least 120°C.
• the plasticiser or blend thereof is preferably used in an amount from 2-30% weight equivalents of the polymer or copolymer.
• the stabiliser or blends thereof is preferably used in an amount from 2-6% weight equivalents of the polymer or copolymer.
• the mixture may include one or more of a) fillers including pigments and dyes, inorganic materials such as barium sulphate or calcium carbonate, or organic materials such as starch and b) conventional auxiliaries such as anti- oxidants and ultraviolet stabilisers.
• the invention also provides a biodegradable article or material manufactured from a homogeneous biodegradable plastics compound prepared by mixing a polyhydroxylated polymer or copolymer with a plasticiser or a blend of plasticisers and a stabiliser or a blend of stabilisers, the stabiliser or blend thereof comprising a surface active agent, dispersing aid and/or mould lubricant and thermoplastically processing the mixture at 120°C to
• thermoplastic processing including compounding the mixture at a temperature in the range of 140°C to 205°C, the resulting compound having a melt flow index of 0.2 to 375 g/10 minutes using 21.6Kg at 190°C (ISO 1133 method), the plasticiser and stabiliser or blends thereof rendering the mixture stable to thermoplastic processing, with the proviso that the stabiliser does not comprise stearamide or stearic acid salt when used singly as the stabiliser at a mixing temperature of 106°C to 140°C with polyvinylalcohol or polyvinylalcohol/ polyvinylacetate copolymer.
• Biodegradation of a material is definable as its breakdown by action of bacteria.
• the ratio expressed as a percentage of the Biological Oxygen Demand over a 5 day period (BOD5), verses its Chemical Oxygen Demand (COD) of a 1% aqueous solution colloidal suspension of test material.
• BOD5 is a measure of bio-digestion by bacteria and the COD reflects the comparative amount of oxygen for the theoretical 100% digestion of the material.
• the BOD5 is critically determined on exposure to an unconditioned, broad spectrum bacteria effluent sludge, typical of municipal effluent water treatment. BOD5 and COD are expressed in mg/1 Oxygen.
• Materials showing poor BOD5/COD may be judged an environmental hazard from the point of view of bio-accumulation (ie at risk of accumulating in the biosphere). Also, as many environmental agencies judge pollution discharge in surface water and ground water by COD measurement, the environmental discharge of non-degrading materials as soluble COD or poorly degrading material, sometimes referred to as 'hard COD', may constitute a risk of breach of permitted environmental discharge limits.
• Uncompounded PVA/PVAc is biodegradable and exhibits a typical BOD5/COD ratio of 0.2 tol%.
• Thermally damaged materials exhibiting visible, UV and IR spectroscopic evidence of degradation, indicated above
• some PVA copolymers exhibit BOD5/COD ratios of less than 0.2% and in some cases less than 0.1%, eg Economaty AX2000 exhibiting visible, UV and IR evidence of thermal degradation gave a BOD5/ COD ratio of ⁇ 0.15%.
• Plasticised PVA compound (10-15 weight % glycerol as plasticiser) exhibits improved biodegradability (BOD5/COD ratios 3-10%) due to decomposition of their plasticiser content and also by the consequential improved inoculation effect accelerating biodegradation of the PVA.
• BOD5/COD ratios 3-10% As with unplasticised materials, materials exhibiting visible, UV and IR spectroscopic evidence of thermal degradation have lower BOD5/COD ratios indicative of poorer biodegradation qualities. Materials with comparable amounts of the same plasticiser can exhibit greatly differing BOD5/COD ratios based on their thermal treatment.
• thermoplastic compounding of plasticised PVA or PVA/PVAc below 185°C will retain the same BOD5/COD ratio of its plasticised compound prior to thermoplastic processing.
• the BOD5/COD ratio falls by 25-50% depending upon the stabiliser/plasticiser enhancer system employed.
• Above 205 °C biodegradation properties as defmed by the BOD5/COD ratio become increasingly compromised. Materials processed above 240°C become so degraded that their PVA content can be regarded as virtually non-biodegradable.
• plasticised PVA compounds manufactured from PVA raw materials demonstrating visible, UV and IR evidence of unsaturation and potential thermal damage whether by dehydration or chemical inclusion or derivatisation of the polymer tend to exhibit poorer BOD5/COD ratios post thermoplastic extrusion, indicating poorer thermal stability.
• the apparent retardation of biodegradation of PVA is disproportionate to the degree of chemical alteration of the material, ie a small amount of thermal degradation, severely slows digestion of the dissolved compound by bacteria.
• the present invention provides an improved method for the manufacture of biodegradable plastic materials comprising mixing a biodegradable polymer, especially PVA/PVAc copolymer (70-95% PVA and 30-5% PVAc) with systems of 'plasticiser' and 'stabiliser' at temperatures from 55-150°C.
• Mixing is typically carried out in a force action blender or other conventional polymer mixing apparatus.
• the exact mixing temperatures reached have been found to be non-critical.
• the key parameters to efficiency of the plasticising process have been found to be mechanical efficiency, temperature and time in combination. Thus, high speed mixing of a compound previously made at a high temperature can be carried out at lower temperature with less vigorous mixing but would require a longer cycle time.
• the action attributed to the stabiliser is to enhance the action of the plasticiser and maintain the stability of the resultant compound.
• the invention relates to the use of combinations of materials in the stabiliser system, which tends to magnify the system's effectiveness.
• the resultant material can be conventionally processed in numerous thermoplastic applications at temperatures of 120-205°C, eg; into blown film, sheet or other extrusion, injection moulded articles, woven or non-woven fibres or expanded foam products, or compounded as pellets for re-use in the aforementioned applications, and the resulting products have superior biodegradability characteristics, as measured by the BOD5/COD ratio, than have conventionally formulated and compounded PVA or PVA/PVAc products.
• the materials produced by the present invention have improved melt flow characteristics as illustrated by their Melt Flow Index (MFI) whilst retaining good strength characteristics, and are therefore capable of being manipulated at lower temperatures than comparable materials previously disclosed, thereby incurring minimal or negligible thermal degradation. Therefore, the materials produced can be worked and re-worked with a greater degree of control and reproducibility of physical performance in application and much less visible discolouring of the material, in particular in applications exhibiting minimal degradation from 205-185°C and in applications exhibiting negligible degradation from 185-120°C. Materials worked below 185°C so that irreversible degradation of the compound is avoided retain the positive biodegradation qualities of their PVA/PVAc starting materials. For example, the present invention renders the material capable of being
• the degree of hydrolysis of PVA plays a role in improving MFI and processability of PVA/PVAc due to a process termed 'internal plasticisation'.
• Simply decreasing the hydrolysis level of PVA/PVAc polymers ie. increasing PVAc content
• the present invention provides for materials whereby the molecular weight (MWt) of the polymer and the composition of the Plasticiser/Stabiliser system may be additionally varied to influence MFI in a predictable and controllable manner.
• Admix 1 in the figure comprises Stearamide: calcium stearate 2:1 and admix 2 comprises Glycerol monostearate: calcium stearate 2:1.
• the data shown in this figure were generated on a Demag S65 machine, using an injection pressure of 666 bar, a holding pressure of 450 bar, a back pressure of 100 bar, a cooling time of 10 sec, a holding time of 2 sec, a cycle time of 20 sec. and a barrel temperature of 180°C with a PVA/glycerol/admix 1 as described above.
• FIG. 5 gives an illustration of the use of levels of Stabiliser from 0-6%), demonstrating significant beneficial effect on lowering Die Temperature and ergo on improving MFI.
• the typical 'S' shape of the illustrations shown in Figure 5 indicate that the significant beneficial effect of relatively higher levels of Stabiliser (namely 2-6%>) is not obtained at lower levels.
• This surprising effect is wholly unpredictable from applications of similar compounds used as mould lubricants at typically lower levels than 2%. At application levels above 5%, screw slip becomes evident and at levels above 6%, the beneficial effect is lost.
• plasticiser employed may be used in the range 2-30% weight equivalents. Plasticiser levels of 2-15%) are generally preferred and the most preferred plasticisers are low- volatile liquids or low melting solids with a melting point of not greater than 100°C.
• low-volatile refers to any material which is normally liquid at 20°C and 1 bar (1 MPa) and whose boiling point is greater than or equal to 150°C at 1 bar (1 MPa).
• the process of the invention has the capability to produce a range of compounded plastic materials with varying physical characteristics, eg; melt flow index, strength, flexibility and rate of dissolution, depending upon the degree of hydrolysis of the PVA/PVAc copolymer, its average molecular weight and the qualities and type of Plasticiser(s) and Stabiliser(s) employed.
• the present invention includes the manufacture of such a range and its use in providing a plastics processor with materials which can be used alone or in any combination so that he may obtain materials to match his specific desired product performance criteria suitable for the manufacture of a wide variety of plastic articles with different performance needs, as exemplified in Table 1 below, which sets out observed technical data for a selection of the materials described in the examples below. Materials such as those whose manufacture is described herebelow, may be blended to give a material of predictable MFI and strength, providing an optimum in performance for a desired application between the two materials.
• the present invention provides for the preparation of materials with varying properties which may be used predictably and reproducibly under real life production application conditions to manufacture multitudinous biodegradable products by conventional thermoplastic processes.
• the 'Plasticiser' may be any material indicated in Schedule A or any combination of materials indicated in Schedule A.
• the 'Stabiliser' may be any compound listed in Schedule B, (excluding stearamide or stearic acid salts when used on their own as sole stabiliser and the compound mixed at a temperature in the range of 106-140°C), or any combination of materials listed in Schedule B (including stearamide and stearic acid salts).
• All materials whose manufacture is described below are homogeneous compounds and may be conventionally blended with fillers, including pigments, dyes, barium sulphate, calcium carbonate or other inorganic materials, starch or other organic fillers and auxiliaries such as anti-oxidants and UV stabilisers.
• Fillers including pigments, dyes, barium sulphate, calcium carbonate or other inorganic materials, starch or other organic fillers and auxiliaries such as anti-oxidants and UV stabilisers.
• Materials with high surface polarity and or acidity or alkalinity such as silica, silicic acid, alumina and titanium dioxide should be avoided unless suitably deactivated by being rendered neutral or by coating such materials with an inert barrier such as mineral oils or silicone fluid.
• PVA/PVAc polymers may be heat damaged, limiting their biodegradation, and describes how they may be manipulated thermoplastically with retention of their biodegradation properties by the super- plasticisation processes described herein, it follows that other co-compounds of PVA/PVAc with other polymeric materials or copolymers of PVA/PVAc with other monomers, eg ethylene, styrene, PET, PBT or other biodegradable monomers e.g. hydroxybutyrates, hydroxyvalerates or caprolactone, or indeed other poly-hydroxlayed polymers not related to PVA/PVAc may be similarly heat damaged with corresponding negative effects on biodegradation.
• monomers eg ethylene, styrene, PET, PBT or other biodegradable monomers e.g. hydroxybutyrates, hydroxyvalerates or caprolactone
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 50,000 - 100 parts Glycerol - 15 parts
• the Ingredients were combined and mixed in a force action blender between 1,500 and 3,000 rpm, until a temperature of 125-135°C was reached.
• the resultant powder was cooled to room temperature, sieved and compounded as pellet using a Prism TSE 16TC twin screw extruder with a 4.5mm die or Blown as film using 90°, 30 mm Blow die.
• Temperatures at the feed-zone, work-zone and die zone were; 170°C, 195°C and 170°C respectively.
• Working pressures were 60-95 bar (6-9.5 MPa). Pale yellow Pellet and film were obtained.
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 50,000 - 100 parts Glycerol - 10 parts
• the Ingredients were combined and mixed in a force action blender between 1 ,500 and 3,000 rpm, until a temperature of 125-135°C was reached.
• the resultant powder was cooled to room temperature, sieved and compounded as pellet using a Prism TSE 16TC twin screw extruder with a 4.5mm die or Blown as film using 90°, 30 mm Blow die.
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 50,000 - 100 parts Glycerol - 5 parts
• the Ingredients were combined and mixed in a force action blender between 1,500 and 3,000 rpm, until a temperature of 125-135°C was reached.
• the resultant powder was cooled to room temperature, sieved and compounded as pellet using a Prism TSE 16TC twin screw extruder with a 4.5mm die or Blown as film using 90°, 30 mm Blow die.
• Temperatures at the feed-zone, work-zone and die zone were; 170°C, 210°C and 210°C respectively.
• Working pressures were 60-95 bar (6-9.5 MPa). Pale yellow Pellet and film were obtained.
• Example 4 (Comparative Example) Ingredients:
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 50,000 - 100 parts
• Example 4A Ingredients:
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 50,000 - 100 parts Glycerol - 10 parts
• the Ingredients were combined and mixed in a force action blender between 1,500 and 3,000 rpm, until a temperature of 120-135°C was reached.
• the resultant powder was cooled to room temperature, sieved and compounded as pellet using a Prism TSE 16TC twin screw extruder with a 4.5mm die or Blown as film using 90°, 30 mm Blow die.
• Temperatures at the feed-zone, work-zone and die zone were; 174°C, 186°C and 174°C respectively.
• Working pressures were 100 bar (10 MPa). Good quality Pellet and film were obtained.
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 50,000 - 100 parts Glycerol - 15 parts Stearamide - 2 parts
• the Ingredients were combined and mixed in a force action blender between 1 ,500 and 3,000 rpm, until a temperature of 80-135°C was reached.
• the resultant powder was cooled to room temperature, sieved and compounded as pellet using a Prism TSE 16TC twin screw extruder with a 4.5mm die or Blown as film using 90°, 30 mm Blow die.
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 50,000 - 100 parts
• the Ingredients were combined and mixed in a force action blender between 1,500 and 3,000 ⁇ m, until a temperature of 80- 135°C was reached.
• the resultant powder was cooled to room temperature, sieved and compounded as pellet using a Prism TSE 16TC twin screw extruder with a 4.5mm die or Blown as film using 90°, 30 mm Blow die.
• Example 6A Ingredients:
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 20,000 - 100 parts
• the Ingredients were combined and mixed in a force action blender between 1,500 and 3,000 ⁇ m, until a temperature of 80-135°C was reached.
• the resultant powder was cooled to room temperature, sieved and compounded as pellet using a Prism TSE 16TC twin screw extruder with a 4.5mm die or Blown as film using 90°, 30 mm Blow die.
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 50,000 - 100 parts Glycerol - 5 parts
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 80,000 - 100 parts Glycerol - 15 parts
• Example 8B Ingredients:
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 80,000 - 100 parts Glycerol - 15 parts
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 20,000 - 100 parts Glycerol - 15 parts
• PVA/PVAc (75-80%PVA:25-20%PV Ac), Ave. MWt 20,000 - 100 parts
• the Ingredients were combined and mixed in a force action blender between 1,500 and 3,000 ⁇ m, until a temperature of 80-123°C was reached.
• the resultant powder was cooled to room temperature, sieved and compounded as pellet using a Prism TSE 16TC twin screw extruder with a 4.5mm die or Blown as film using 90°, 30 mm Blow die.
• Example 9C Ingredients:
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 20,000 - 100 parts
• the Ingredients were combined and mixed in a force action blender between 1,500 and 3,000 ⁇ m, until a temperature of 80-123 °C was reached.
• the resultant powder was cooled to room temperature, sieved and compounded as pellet using a Prism TSE 16TC twin screw extruder with a 4.5mm die or Blown as film using 90°, 30 mm Blow die.
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 20,000 - 100 parts Glycerol - 15 parts
• Temperatures at the feed-zone, work-zone and die zone were; 150°C, 170°C and 125°C respectively.
• Working pressures were 50-85 bar (5-8.5 MPa). Good quality Pellet and film were obtained.
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 20,000 - 100 parts Glycerol - 2 parts
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 20,000 - 100 parts
• the Ingredients were combined and mixed in a force action blender between 1,500 and 3,000 ⁇ m, until a temperature of 80-123 °C was reached.
• the resultant powder was cooled to room temperature, sieved and compounded as pellet using a Prism TSE 16TC twin screw extruder with a 4.5mm die or Blown as film using 90°, 30 mm Blow die.
• Example 10 Ingredients:
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 50,000 - 100 parts
• the Ingredients were combined and mixed in a force action blender between 1,500 and 3,000 ⁇ m, until a temperature of 80-123 °C was reached.
• the resultant powder was cooled to room temperature, sieved and compounded as pellet using a Prism TSE 16TC twin screw extruder with a 4.5mm die or Blown as film using 90°, 30 mm Blow die.
• Example 11A Ingredients:
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 50,000 - 100 parts Glycerol - 12 parts
• the Ingredients were combined and mixed in a force action blender between 1,500 and 3,000 ⁇ m, until a temperature of 80-123°C was reached.
• the resultant powder was cooled to room temperature, sieved and compounded as pellet using a Prism TSE 16TC twin screw extruder with a 4.5mm die or Blown as film using 90°, 30 mm Blow die.
• Temperatures at the feed-zone, work-zone and die zone were; 152°C, 175°C and 129°C respectively.
• Working pressures were 60-80 bar (6-8 MPa). Good quality Pellet and film were obtained.
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 50,000 - 100 parts
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 50,000 - 100 parts
• the Ingredients were combined and mixed in a force action blender between 1,500 and 3,000 ⁇ m, until a temperature of 80-123°C was reached.
• the resultant powder was cooled to room temperature, sieved and compounded as pellet using a Prism TSE 16TC twin screw extruder with a 4.5mm die or Blown as film using 90°, 30 mm Blow die.
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 50,000 - 100 parts
• the Ingredients were combined and mixed in a force action blender between 1,500 and 3,000 ⁇ m, until a temperature of 80-123°C was reached.
• the resultant powder was cooled to room temperature, sieved and compounded as pellet using a Prism TSE 16TC twin screw extruder with a 4.5mm die or Blown as film using 90°, 30 mm Blow die.
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 20,000 - 100 parts Triacetin - 15 parts
• PVA PVAc 80-95%PVA:5-10%PVAc
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 50,000 - 100 parts Glycerol - 15 parts
• Example 14 Ingredients:
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 50,000 - 100 parts
• the Ingredients were combined and mixed in a force action blender between 1 ,500 and 3 ,000 ⁇ m, until a temperature of 80- 135 °C was reached.
• the resultant powder was cooled to room temperature, sieved and compounded as pellet using a Prism TSE 16TC twin screw extruder with a 4.5mm die or Blown as film using 90°, 30 mm Blow die.
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 50,000 - 100 parts Glycerol - 15 parts
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 50,000 - 100 parts Glycerol - 15 parts
• the resultant powder was cooled to room temperature, sieved and compounded as pellet using a Prism TSE 16TC twin screw extruder with a 4.5mm die or Blown as film using 90°, 30 mm Blow die.
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 50,000 - 100 parts Glycerol - 15 parts
• Arquard HC Pastilles (Trade Mark of Akzo Nobel) (dimethyl-ditallow-ammonium chloride) - 3.0 parts
• the Ingredients were combined and mixed in a force action blender between 1,500 and 3,000 ⁇ m, until a temperature of 80-135°C was reached.
• the resultant powder was cooled to room temperature, sieved and compounded as pellet using a Prism TSE 16TC twin screw extruder with a 4.5mm die or Blown as film using 90°, 30 mm Blow die.
• Temperatures at the feed-zone, work-zone and die zone were; 160°C, 175°C and 146°C respectively.
• Working pressures were 65-70 bar (6.5-7.0 MPa). Good quality Pellet and film were obtained.
• Example 18A Ingredients:
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 50,000 - 100 parts
• the Ingredients were combined and mixed in a force action blender between 1,500 and 3,000 ⁇ m, until a temperature of 80-135°C was reached.
• the resultant powder was cooled to room temperature, sieved and compounded as pellet using a Prism TSE 16TC twin screw extruder with a 4.5mm die or Blown as film using 90°, 30 mm Blow die.
• PVA/PVAc (75-80%PVA:25-20%PVAc), Ave. MWt 50,000 - 100 parts Triethyl citrate (Al Jungbunzlaur) - 15 parts Stearamide - 2 parts Calcium Stearate - 1 part
• the Ingredients were combined and mixed in a force action blender between 1 ,500 and 3,000 ⁇ m, until a temperature of 80-135°C was reached.
• the resultant powder was cooled to room temperature, sieved and compounded as pellet using a Prism TSE 16TC twin screw extruder with a 4.5mm die or Blown as film using 90°. 30 mm Blow die.
• Temperatures at the feed-zone, work-zone and die zone were; 183°C, 183°C and 159°C respectively.
• Working pressures were 95-10 bar (9.5-10 MPa). Good quality Pellet and film were obtained. (NB: excessive temperature on subsequent heat treatment can cause the plasticiser in this material to yellow significantly.
• citric acid C, to C 4
• alcohol tri-esters or mixed tri-esters or glycol esters or (C j -C 4 ) acid esters thereof or
• Lactic acid (C, to C 4 ) alcohol esters ethylene or propylene glycol esters.
• Any vegetable base oils eg.; soya oil or corn oil.
• Any gum resin materials used as dispersing aids eg. Permalyn 5095 or 5110 (Trademark; Hercules Chemicals).
• Any wax ionomer or dispersing aid eg. Aclyn 295A (Trademark; Allied Signal Inc).
• sorbitan fatty ester eg. Span 20 to 85, (Trademark; Atlas Chemical Inc.) etc.

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

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• 1997
  • 1997-04-15 IE IES970280 patent/IES970280A2/en not_active IP Right Cessation
• 1998
  • 1998-03-06 CA CA002283499A patent/CA2283499A1/en not_active Abandoned
  • 1998-03-06 AU AU65153/98A patent/AU6515398A/en not_active Abandoned
  • 1998-03-06 EP EP98910956A patent/EP0964887A1/de not_active Withdrawn
  • 1998-03-06 WO PCT/IE1998/000022 patent/WO1998039382A1/en not_active Application Discontinuation

Non-Patent Citations (1)

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