MXPA97000637A - Pipe assembly for san collection - Google Patents

Abstract

The present invention relates to a sample assembly, which comprises: open, a closed end, an internal surface and an external surface, and a barrier covering, multiple cups, associated on the outer surface of the container, and which extends over a larger portion of the outer surface of the container, this coating has a first cup, comprising a PVDC coating material, and a second layer, on the first layer, comprising a metal oxide.

Description

PIPE SET FOR BLOOD COLLECTION BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a multilayer barrier coating, to provide an effective barrier against the permeability of gas and water to containers, especially plastic tubes for blood collection. 2. Description of the Related Art With the increasing emphasis on the use of plastic products for medicine, there is a special need to improve the barrier properties of articles made of polymers. These medical products that would derive a considerable benefit from improving their barrier properties include, but are not limited to, collection tubes and particularly those used for blood collection. These blood collection tubes require certain standards. of performance are acceptable for use in medical applications. Such performance standards include the ability to maintain more than 90% of the original volume of extraction in a period of one year, be sterilizable by means of radiation and not interfere in testing and analysis. Therefore, there is a need to improve the barrier properties of articles made of polymers and, in particular, in evacuated plastic tubes for blood collection, in which certain performance standards must be met and the article is effective and can be used in medical applications. SUMMARY OF THE INVENTION The present invention relates to a container made of plastic, comprising at least two barrier materials arranged on the external or internal surface of the composite container, previously formed. Conveniently, the barrier coating materials comprise a first layer of a polymeric material, applied to the outer surface of the composite container, previously formed, a second layer of a polymeric material, applied to the first layer, and, optionally, a third layer of an organic material, applied on the second layer. The first layer, a size coat, is preferably of an organic barrier composition, such as polyvinylidene chloride (PVDC). The coating can be formed on a portion of the inner surface, on a portion of the outer surface, or on both surface portions of the container. The second layer of the barrier coating is preferably of a composition based on silicon oxide, such as SiOx, wherein x is from 1.0 to about 2.5; or a composition based on aluminum oxide. More preferably, the second layer is of a composition based on silicon oxide, applied on the first layer. The optional third layer of the barrier coating, preferably an organic barrier composition, such as polyvinylidene chloride (PVDC), is more preferably applied on the second layer. Preferably, the size coat and the optional third layer comprises a polymer of vinylidene chloride-methyl methacrylate-methacrylate-acrylic acid (PVDC), epoxy coating of stable materials, polymers or parylene polyesters. Preferably, the thickness of the PVDC sizing coating is about 500 to 1,200 microns and more preferably about 700 to 1,000 microns. A second convenient layer, which is disposed on the first layer, comprises a composition based on silicon oxide, such as SIOx. Such a film is conveniently derived from volatile organic silicon compounds.

The composition based on silicon oxide provides a dense coating, impervious to steam, on the organic coating of sizing. Preferably, the thickness of the silicon oxide-based layer is from about 100 to 10,000 Angstroms (Á) and more preferably from about 1,000 to 3,000 Á. A coating above 5,000 Á can be split and, therefore, it is not effective as a barrier. A third optional convenient layer is disposed on the second layer. Preferably this third optional layer of PVDC, which is disposed on the second layer, has approximately a thickness of 500 to 1,200 microns and more preferably of about 700 to 1,000 microns. The PVDC layers can be applied by immersion or spraying techniques. A method for depositing a film based on silicon oxide is as follows: (a) pretreat the first layer on the container with a first coating of oxygen plasma; (b) flowing, in a controlled manner, a gas stream, which includes an organic silicon compound, into the plasma; and (c) depositing a silicon oxide on the first layer, while maintaining a pressure of less than about 500 mTorr, during deposition. Although the pre-treatment step is optional, it is believed that this pre-treatment step provides better adhesion qualities between the second layer and the size coat. The organic silicon compound is preferably combined with oxygen and, optionally, with helium, or another inert gas, such as argon or nitrogen, and at least a portion of the plasma is confined, preferably in magnetic form, adjacent to the surface of the first layer during deposition, more preferably by an unbalanced magnetron. More preferably, the method for depositing a barrier coating on a substrate, such as a plastic collection tube, comprises the following steps: (a) immersing the surface of the substrate in an emulsion-based PVDC solution; (b) thermally curing the solution on the substrate; (c) vaporizing an organic silicon component and mixing this volatilized organic silicon component with an oxidizing component and, optionally, a component of an inert gas, to form a gas stream outside the chamber; (d) establishing an irradiation discharge plasma in the chamber, from one or more of the components of the gas stream; (e) flowing, in a controllable manner, the gas stream within the plasma, while confining at least a portion of the plasma there; and (f) depositing a second layer of a silicon oxide coating, adjacent to the first layer of PVDC. Optionally, a third layer of a PVDC coating can be applied on the second layer by immersion or spraying techniques. An emulsion-based PVDC solution can be used to submerge the surface of the vessel, followed by thermal curing. PVDC solutions based on solvents, where the solvent is CHCI3, CCI4 and the like, can be used for spray coating, followed by thermal curing. Optionally, the container and / or the first layer can be treated by flame or treated by plasma oxygen or treated by corona discharge, before applying the multilayer coatings. Plastic tubes coated with a multilayer barrier coating, comprising a size coat, and an oxide layer and an overcoat layer are able to substantially maintain much better vacuum retention, extraction volume and its retention of mechanical integrity, compared to the previous tubes comprised of polymer compositions and mixtures thereof, without a coating of barrier materials, or of tubes comprising only an oxide coating. In addition, the resistance of the tube to impact is much better than that of the glass. Most notable is the clarity of the multilayer coating and its durability to substantially withstand impact and abrasion resistance. More preferably, the container of the present invention is a blood collection device. This blood collection device can be either an evacuated blood collection tube or a non-evacuated blood collection tube. This blood collection tube is conveniently made of polyethylene terephthalate, polypropylene, polyethylene naphthalate or its copolymers. An impression can be placed on the multilayer barrier coating applied to the container of interest. For example, a product identification, bar code, trade name, company logo, lot number, expiration date and other data and information may be included on the barrier coating. Also, the matte finish or a corona discharge surface can be developed over the barrier coating, in order to make the surface suitable for additional written information on the label. Similarly, a pressure-sensitive adhesive label can be placed on the barrier coating to accommodate several hospital over-labels, for example. Preferably, the multilayer barrier coating of the present invention provides a clear or colorless appearance and may have printed matter applied thereto. A further advantage is that the method of the present invention provides a reduction in gas permeability of three-dimensional objects, which has not been achieved with a conventional deposit method, typically used, with thin films. It has been found in the present invention that the organic material, the epoxide, provides a good platform for the growth of dense SiOx barrier material. It has been found that the epoxy layer improves the adhesion between a plastic surface and the SiOx and, in general, improves the thermomechanical stability of the coated system. In addition, the epoxy sizing coating has a role of a smoothing (leveling) layer, which covers the particles and imperfections on the surface of a polymer and reduces the density of defects in deposited inorganic coatings. The good binding properties of the PVDC are also due to the fact that the PVDC is polar and the polarity provides a means for good bonding between SiOx and PVDC. further, it has been found that a good bonding formation is obtained between plastic tubes made of polypropylene and PVDC. Thus, the present invention provides the resources to substantially improve the barrier properties of polypropylene tubes. The adhesion properties of both the PVDC coating and the oxide coating can be further improved substantially by prior methods of surface treatment, such as flame or oxygen plasma. Therefore, a significant reduction in the permeability of the article is due to the substantially improved SiOx surface coating, which is obtained by the use of a PVDC sizing coating on the surface of the plastic article. The third optional layer of the PVDC improves the layer of SiOx, because it covers its defects and / or irregularities in the SiOx layer. Also, the PVDC coating improves the abrasion resistance of the SiOx coating. A plastic blood collection tube, coated with a multilayer barrier coating, according to the present invention, will not interfere with the testing and analysis traditionally performed on the blood within the tube. These tests include, but are not limited to, routine chemical analysis, biological inertness, hematology, blood chemistry, blood type, toxicology analysis or therapeutic drug monitoring and other clinical tests involving bodily fluids. Likewise, a plastic blood collection tube coated with the barrier coating is capable of being treated by an automatic machinery, such as centrifuges, and can be exposed to certain levels of radiation in the sterilization process substantially without change in the optical or mechanical and functional properties. DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a typical blood collection tube, with a stopper. Figure 2 is a longitudinal sectional view of the tube of Figure 1, taken along line 2-2; Figure 3 is a longitudinal sectional view of a tube-shaped container, similar to the tube of Figure 1; , without a plug, comprising a multilayer barrier coating. Figure 4 is a longitudinal sectional view of a tube-shaped container, similar to the tube of Figure 1, with a stopper, comprising a multilayer barrier coating. Figure 5 is a longitudinal sectional view of a further embodiment of the invention illustrating the tube with a plug similar to Figure 1 and with the multilayer barrier coating covering both the tube and its cap.

Figure 6 illustrates a plasma deposit system. Figure 7 is a general schematic diagram, illustrating the layers that are deposited on a substrate. DETAILED DESCRIPTION The present invention can be incorporated into other specific forms and is not limited to any specific modality described in detail, which is merely exemplary. Various other modifications will become apparent and will be readily available to those skilled in the art, without departing from the scope and spirit of the invention. The scope of the invention will be measured by the appended claims and their equivalents. With reference to the drawings, in which similar reference characters refer to similar parts in all the various views. Figures 1 and 2 show a typical blood collection tube 10, having a side wall 11, extending from an open end 16 to a closed end 18, and a stopper 14, which includes a lower annular portion of a flap 15, which extends inside and is pressed against the inner surface 12 of the side wall, to hold the plug 14 in place. Figure 2 schematically illustrates that there are three mechanisms for a change in vacuum in a blood collection tube: (A) a gas permeation material through the stopper; (B) a gas permeation material through the tube and (C) the exhaust at the tube interface and the plug. Therefore, when there is substantially no gas permeation and no leakage, there is good vacuum retention and good retention of the extraction volume. Figure 3 shows the preferred embodiment of the invention, a plastic tube coated with at least two layers of barrier materials. The preferred embodiment includes many components, which are substantially identical to the components of Figures 1 and 2. Therefore, FIG. similar components that perform similar functions will be numbered identically to those components of Figures 1 and 2, except that an "a" suffix will be used to identify those components in Figure 3. Referring now to Figure 3, the preferred embodiment of the invention, the collection tube assembly 20 comprises a plastic tube 10a, having a side wall Ia, extending from an open end 16a to a closed end 18a. A barrier coating 25 extends over a substantial portion of the inner surface of the tube, with the exception of the open end 16a. The barrier coating 25 comprises a first layer 26 of a polymer material, such as an acrylate, a second layer 27 of a multiple sequence of inorganic and organic coatings, and a third layer 28 of an organic overcoat layer. , such as the PVDC. Figure 4 illustrates an alternative embodiment of the invention, in which the collection tube assembly 40 comprises a plug 48 instead of the open end 41 closing the tube 42. As can be seen, the side wall 43 extends from the end open 41 to closed end 44 and plug 48 includes an annular upper portion 50, which extends over the upper edge of tube 42. Plug 48 includes a lower annular portion or skirt 49, which extends into and presses against the surface inside 46 of side wall 43, to hold plug 48 in place. Likewise, the plug has a septum portion or partition 52, for receiving a cannula therethrough. Thus, the user, once he receives a container, as shown in Figure 4, with a sample contained therein, can insert a cannula through the septum 52 to receive part or all of the contents in the tube 42, for perform several tests on a sample. Covering a substantial portion of the length of the tube is a multilayer barrier coating 45. The multilayer barrier coating 45 covers substantially the majority of the tube, with the exception of its open end 41. The multilayer barrier coating 45 comprises a first layer 54 of a polymer material, such as the PVDC, a second one. layer 56 of an inorganic material, such as a silicon oxide material, and a third layer 57 of an organic barrier material, such as PVDC. Figure 4 differs from the embodiment of Figure 3, in that the tube can be evacuated with the simultaneous placement of the plug 48, after the application of the layers 54 and 56 on the tube. Alternatively, the multilayer barrier coating can be applied to the tube after it has been evacuated. Figure 5 shows one more mode of barrier coating and a tube. The alternative modality operates in a manner similar to the modality illustrated in Figure 4. Therefore, similar components that perform similar functions will be numbered identically to the components in the modality of Figure 4, except that the suffix "a "to identify those components in Figure 5. Referring now to Figure 5, a further embodiment of the invention, wherein the multilayer coating 45a incorporates both the upper portion 50a of the cap 48a, as well as the entire surface external tube 42a. The multilayer barrier coating 45a includes saw teeth 62 at the tube interface and plug. These teeth are coincident, so that it can be determined if the sealed container has been violated. Such an embodiment can be used, for example, to seal the container with the cap in place. Once the sample has been placed inside the tube, the sample can not be violated by removing the plug. Additionally, the teeth can be coincident, so that it can be determined if the sealed container has been violated. Such an arrangement may be appropriate, for example, in drug abuse testing, identification of specimens and quality control. In an alternative embodiment of the invention, the multilayer barrier coating 45 is applied repeatedly or in sequence to the inner and / or outer surface of the tube. Preferably, the coating is applied at least twice. Practitioners of the art will understand that such tubes may contain reagents in the form of additives or coatings on the inner wall of the tube. The multilayer barrier coating forms a substantially clear or translucent barrier. Therefore, the contents of a plastic tube with a multilayer barrier coating, comprising at least two layers of barrier materials, are substantially visible to the observer at the same time as it identifies the information, which can be displayed on The multilayer barrier coating, after it has been applied to the plastic tube.

The first layer of the multilayer barrier coating can be formed on the tube by a dip coating, roller coating or by spraying an aqueous emulsion of the PVDC homopolymer, followed by thermal curing. The first and third layers may preferably be copolymers of vinylidene chloride-acrylonitrile-methyl methacrylate-methyl acrylate-acrylic acid, thermoset epoxy coatings, polymers or parylene polyesters. Preferably, the first and third layers are of a parylene polymer. Parylene is the generic name of the members of a series of polymers developed by Union Carbide Corporation. The basic member of this series, called the parylene N, is poly-p-exlylene, which is a linear crystalline material.

Parylene C, a second member of the parylene series, is produced from the same monomer as parylene N and modified by the substitution of a chlorine atom for one of the aromatic hydrogens: Parylene D, a third member of the parylene series, is produced from the same monomer as parylene N and modified by a substitution of the chlorine atom by two of the aromatic hydrogens: More preferably, the layer is a polymer of vinylidene chloride-methyl methacrylate-methacrylate-acrylic acid (PVDC). This polymer is available as DARAN® 8600-C (trademark of WR Grace and Co.), sold by GRACE, Organic Chemicals Division, Lexington, Mass., USA The first and third layers of the barrier coating, a polymer material, it can be a parylene polymer applied to the second layer by a process similar to vacuum metallization, as described in US Patents Nos. 3,342,754 and 3,300,332, the disclosures of which are incorporated herein by reference. Alternatively, the third layer may be a polymer of vinylidene chloride-acrylonitrile-methyl methacrylate-methyl acrylate-acrylic acid, applied to the second layer by dip coating, roller coating or by spraying an aqueous emulsion of the polymer, followed by by air drying the coating, as described in U.S. Patent Nos. 5,093,194 and 4,497,859, the disclosures of which are incorporated herein by reference. The second layer of the multi-layer barrier coating, an inorganic material, can be formed on the acrylate coating by radiofrequency discharge, direct or double deposit of ion beams, electronic deposit or plasma chemical vapor deposition, as described in U.S. Patent Nos. 4,698,256, 4,809,876, 4,992,298 and 5,055,318, the disclosures of which are incorporated herein by reference. For example, a method of depositing an oxide coating is provided by establishing a radiation discharge plasma in the previously evacuated chamber. The plasma is derived from one or more components of the gas stream and is preferably derived from the gas stream itself. The article is placed in the plasma, adjacent preferably to the confined plasma, and the gas stream flows controllably into the plasma. A film based on silicon oxide is deposited on the substrate to a desired thickness. The thickness of the oxide coating is approximately 100 to 10,000 Angstroms (Á). A thickness less than 5,000 A can provide a sufficient barrier, and a thickness greater than about 5,000 can form cracks, thus decreasing the effectiveness of the barrier. More preferably, the thickness of the oxide coating is from about 1,000 to 3,000 Á. Another method for depositing an oxide coating is by confining a plasma with a magnetic field. Preferably, the magnetically improved method for depositing a film based on silicon oxide on a substrate is preferably conducted in a previously evacuated chamber and colliding or initiating a radiation discharge from a gas stream. This gaseous stream preferably comprises at least two components: a component of volatized organic silicon, an oxidizing component, such as oxygen, nitrous oxide, carbon dioxide or air, and, optionally, an inert gas component. Examples of suitable organic silicon compounds, useful in plasma deposition methods, are liquid or gaseous at room temperature and have, when volatilized, a boiling point of about 0 to 150 ° C., include: dimethylsilane, trimethylsilane, diethylsilane , propylsilane, phenylsilane, hexamethyldisilane, 1,2,2-tetramethyldisilane, bis- (trismethylsilane) methane, bis- (dimethylsilyl) -methane, hexamethyldisiloxane, vinyltrimethoxysilane, vinyltriethoxysilane, ethylmethoxysilane, ethyltrimethoxysilane, divinyltetramethyldisiloxane, hexamethyldisilazane, divinyl-hexamethyltrisiloxane, trivinyl-pentamethyltrisiloxane, tetraethoxysilane and tetramethoxysilane. Among the preferred organic silicones are 1, 1, 3, 3-tetramethyldisiloxane, trimethylsilane, hexamethyldisiloxane, vinyltrimethylsilane, methyltrimethoxysilane, vinyltrimethoxysilane and hexamethyldisilazane. These preferred organic silicon compounds have boiling points of about 71, 55.5, 102, 123 and 1272C, respectively. The optional inert gas of the gas stream is preferably helium, argon or nitrogen. The volatized organic silicon component is preferably mixed with the oxygen component and the inert gas component, before flowing into the chamber. The quantities of these gases, thus mixed, are controlled by the flow controllers, in order to control, in an adjustable manner, the ratio of the flow rate of the components of the gas stream.

Various optical methods known in the art can be used to determine the thickness of the deposited film while in the deposit chamber or the thickness of the film can be determined after the article is removed from the deposit chamber. The deposition method of the present invention is preferably practiced at a relatively high power and a fairly low pressure. A lower pressure of about 500 milliTorr (Torr) must be maintained during the deposit, and preferably the chamber is at a pressure between 50 and 500 mTorr, approximately, during film deposition. The low pressure of the system results in lower deposit rates, while the higher system pressure provides higher deposit rates. When the plastic article to be coated is sensitive to heat, the higher pressure of the system can be used to minimize the amount of heat to which the substrate is exposed during deposit, because the high substrate temperatures they are avoided for polymers with low transition temperature to glass (Tg), such as polypropylene and PET (Tio of -ioac and 60se, respectively) The substrate is electrically isolated from the deposit system, (except for electrical contact with the plasma) and is at a temperature of less than about 80 ° C. during the deposit, that is, the substrate is not deliberately heated With reference to Figure 6, the system for depositing a film based on silicon oxide comprises a enclosed reaction 170, within which a plasma is formed and within which a substrate or tube 171 is placed, to deposit a thin film of material on a sample holder 172. Substrate can be of any material compatible with vacuum, such as plastic. One or more gases are supplied to the reaction chamber by the gas supply system 173. An electric field is created by a power supply 174. The reaction chamber can be of an appropriate type to make any deposit of chemical vapor enhanced by plasma (PECVD) or a plasma polymerization process. Also, the reaction chamber can be modified so that one or more articles can be coated with an oxide layer simultaneously inside the chamber. The pressure in the chamber is controlled by a mechanical pump 188, connected to the chamber 170 by a valve 190. The tube to be coated is first faced within the chamber 170 in a sample holder 172. The chamber pressure is reduced to almost 5 mTorr by a mechanical pump 188. The operating pressure of the chamber is approximately 90 to 140 mTorr for the PECVD or plasma polymerization process and is achieved by the flow of the chamber. the process gases, oxygen and trimethylsilane, inside the chamber through the monomer inlet 176. The thin film is deposited on the external surface of the tube and has a desired uniform thickness or the deposition process can be periodically interrupted to minimize the heating of the substrate and / or the electrodes and / or physically remove the particulate matter from the articles . The magnets 196 and 198 are positioned behind the electrode 200, to create an appropriate combination of magnetic and electrical fields in the region of the plasma around the tube. The system is suitable for low frequency operation. An example frequency is 40 kHz. However, there may be some advantages of operating at a much higher frequency, such as in the radiofrequency range of several megahertz. The film based on the silicon oxide or its mixtures used according to this description may contain additives and conventional ingredients that do not adversely affect the properties of the articles obtained therefrom.

As shown in Figure 7, the epoxide coating A and coating B based on silicon oxide may have defects or irregularities C. It is believed that the complete coverage of the substrate D can not be achieved with only the epoxy coatings and that one based on silicon oxide. Thus, a third coating of the PVDC, E, can be applied over the silicon oxide coating, to produce a substantially complete barrier coating on the surface of the substrate. A variety of substrates can be coated with a barrier coating by the process of the present invention. Such substrates include, but are not limited to packs, containers, bottles, jars, tubes and medical devices. A plastic tube for blood collection, coated with the coating of the multilayer barrier, will not interfere with tests and analyzes, which are traditionally performed on blood in a tube. Such tests include, but are not limited to, routine chemical analysis, inert biological status, hematology, blood chemistry, blood type, toxicology analysis or therapeutic drug monitoring, and other clinical tests involving body fluids. Also, the plastic blood collection tube, coated with the barrier coating, is capable of being treated with an automatic machinery, such as centrifuges, and can be exposed to certain radiation levels in the sterilization process, substantially without change in the optical or mechanical and functional properties. A plastic blood collection tube, coated with the multilayer barrier coating, is capable of maintaining 90% of the original volume extracted, in a period of one year. The retention of the volume of extraction depends on the existence of a partial vacuum, or a reduced pressure, inside the tube. The extracted volume changes in direct proportion to the change in vacuum (reduced pressure). Therefore, the retention of the extraction volume depends on the good retention of the vacuum. A plastic tube coated with a barrier coating substantially prevents gas permeation through the tube material, in order to maintain and increase the vacuum retention and the retention of the volume extracted from the tube. The plastic tubes without the multilayer coating of the present invention can maintain about 90% of the extracted volume for about 3 to 4 months. If the coating of the multilayer barrier is also coated or applied on the inner surface of the plastic blood collection tube, the barrier coating can be hemo-repellent and / or have characteristics of a clot activator.

It will be understood that no difference is made if the plastic composite container is evacuated or not evacuated, in accordance with this invention. The presence of a barrier coating on the external surface of the container has the effect of maintaining the overall integrity of this container that retains the sample, so that it can be properly disposed without any contamination to the user. Remarkable is the clarity of the barrier coating, when it is coated or applied over the container, and its resistance to abrasion and scrapes. The barrier coating used in accordance with this disclosure may contain conventional additives and ingredients that do not adversely affect the properties of the articles made therefrom. The following examples are not limited to any specific embodiment of the invention, and are only illustrative. EXAMPLE 1 METHOD FOR COVERING PLASTIC SUBSTRATES WITH MULTI-LAYER BARRIER COATINGS A water-based emulsion of the PVDC copolymer was applied to the substrate by rolling the emulsion onto the substrate and baking for 15 to 20 minutes at 682C. The substrate coated with the PVDC emulsion was then cleaned with a mixture comprising equal parts of a solution of a micro-detergent and deionized water (DI). The substrate was rinsed thoroughly in DI water and allowed to air dry. The cleaned substrate was then stored in a vacuum oven at room temperature until the time it was to be coated. The clean substrate was then attached to a support, which was mounted halfway between the electrodes in the glass vacuum chamber. The chamber was closed and a mechanical pump was used to achieve a basic pressure of 5 mTorr. The electrode configuration is capacitively coupled internally with permanent magnets on the back side of titanium electrodes. This special configuration provides the ability to confine the irradiation between the electrodes, due to the increase in the probability of collision between electrons and reactive gas molecules. The net result of applying a magnetic field is similar to increasing the power applied to the electrodes, but without the disadvantages of increased bombardment energies and increased substrate heating. The use of the magnetron discharge allows operation in the low pressure region and a substantial increase in the polymer deposition regime. The monomer consisting of a mixture of trimethylsilane (TMS) and oxygen was introduced through a stainless steel pipe near the electrodes. The gases were mixed in the monomer inlet line, before being introduced into the chamber. Flow rates were manually controlled by stainless steel valves for dosing. A power supply operation at an audible frequency of 40 kHz was used to supply the power to the electrodes. The system parameters used for deposition of the TMS / O2 polymerized plasma thin film on the polymer substrate were as follows: Previous Treatment TMS Flow = 0 sccm Superficial Base Pressure = 5 mTorr Oxygen Flow = 10 sccm System Pressure = 140 mTorr Power = 50 Watts Time = 2 minutes Ó Wx? IJ-d? OW "Fl, uj. od, e ™ TM, S, - = 0.75 - 1.0 sccm Oxygen Flow = 2.5 - 3.0 sccm System Pressure 90-100 mTorr Power 30 watts Storage Time 5 minutes sccm = standard cubic centimeters per minute After depositing the thin film , the reactor was allowed to cool. The reactor was then opened and the substrate removed. A top protective coating of a water-based emulsion of the PVDC copolymer was then applied by the dip coating and cured at 65dC for 10 minutes to produce a final coating thickness averaging about 6 microns. EXAMPLE 4 COMPARISON OF SUBSTRATES WITH AND WITHOUT MULTI-LAYER BARRIER COATINGS All substrates prepared according to Example 1 above, oxygen permeance (OTR) was evaluated in the oxide coatings, as follows. (i) Oxygen Permeance (OTR) Oxygen permeance (OTR) film or plate samples were tested using the MO WITH Ox-TRAN 2/20 apparatus (sold by Modern Controls, Inc., of 7500 Boone Avenue N Minneapolis, MN 55428). A single side of the film sample was exposed to a 100% oxygen atmosphere. Oxygen permeation through the sample film was entrained in a stream of nitrogen carrier gas on the opposite side of the film and detected by a COULMETRIC sensor. An electrical signal was produced in proportion to the amount of oxygen permeation through the sample. Samples were tested at 30 ° C and relative humidity (H.R.). The samples were conditioned for 1 to 20 hours before determining the oxygen permeance. The results are given in Table 1, in units of cc / m2-atm-day. Oxygen permeance (OTR) tube samples were tested using a MOCON Ox-TRAN 1,000 apparatus (sold by Modern Controls, Inc., 7500 Boone Avenue N., Minneapolis, MN 55428). A pack adapter was used to mount the tubes so as to allow the outside of the tube to be immersed in a 100% O2 atmosphere, while the interior of the tube is flooded with nitrogen carrier gas. The tubes were then tested at 202C and 50% H.R. These tubes were allowed to equilibrate for 2-14 days, before determining a steady state permeability. The results are given in Table 1 in units of cc / m2-atm.-day.

TABLE 1 Second layer = 1000 - 3000 Angstroms (as measured by the Electron Microscope of Sweeping PP = polypropylene tubes = nominal wall thickness = 102 microns PVDC = first layer = Angst.roms third layer = Angstroms

Claims (16)

1. CLAIMS 1. A sample assembly, which comprises: a plastic container, having an open end, a closed end, an internal surface and an external surface; and a multi-layered barrier coating, associated on the outer surface of the container, and extending over a larger portion of the outer surface of the container, this coating has a first layer, comprising a PVDC coating material, and a second layer, on the first layer, comprising an oxide of a metal.
2. 2. The assembly of claim 1, further comprising a third layer, on the second layer, which includes an organic material.
3. 3. The assembly of claim 1, further comprising a closure at the open end of the container, whereby an interface of the container and closure is formed.
4. The assembly of claim 3, wherein the coating of the multilayer barrier includes saw teeth in correspondence, against violations, adjacent to the container interface and closure.
5. 5. The assembly of claim 1, wherein the second layer is of a composition based on aluminum oxide or silicon oxide.
6. 6. The assembly of claim 5, wherein the second layer comprises the silicon oxide.
7. The assembly of claim 5, wherein the second layer is deposited by radiofrequency discharge, direct deposit of ion beams, double deposition of ion beams, electronic deposit, chemical vapor deposition of plasma or magnetically increased plasma systems .
8. The assembly of claim 2, wherein the third layer is thermoset epoxy, parylene polymer, vinylidene chloride-acrylonitrile methyl methacrylate polymer-methyl acrylate-acrylic acid polymer, or polyesters.
9. The assembly of claim 2, wherein the second layer comprises the silicon oxide and the third layer comprises the polyvinylidene chloride.
10. The assembly of claim 1, further comprising a multilayer barrier coating on the inner surface of the container, having a first layer including the PVDC, a second layer, on the first layer, of a metal oxide and a third layer of an organic material.
11. 11. A multi-layer barrier coating, which comprises:: a first layer including the PVDC; a second layer, on the first layer, which includes a metal oxide; and a third layer, on the second layer, comprising an organic material.
12. 12. The coating of claim 11, wherein the second layer is aluminum oxide or silicon oxide.
13. The coating of claim 11, wherein the third layer is polyvinylidene chloride.
14. 14. A method for depositing a multilayer barrier coating on a plastic substrate, within a previously evacuated chamber, this method comprises: (a) immersing a PVDC emulsion; (b) curing said emulsion; (c) vaporizing an organic silicon component and mixing this volatilized organic silicon component with an oxidizing component and, optionally, a component of an inert gas, to form a gas stream outside the chamber; (d) establishing an irradiation discharge plasma in the chamber, from one or more of the components of the gas stream; (e) flowing, in a controllable manner, the gas stream within the plasma, while confining therein at least a portion of the plasma; and (f) depositing a second layer of a silicon oxide coating, adjacent to the first layer.
15. 15. The method of claim 14, further comprising: (g) dip coating a third layer of PVDC on the second layer.
16. 16. The method of claim 14, wherein the first layer is pretreated with oxygen plasma.