MXPA97000639A - Pipe assembly for san collection - Google Patents

Abstract

The present invention relates to a plastic container coated with a multilayer barrier coating. This multi-layer barrier coating is useful to provide an effective barrier against gas permeability in vessels and to prolong the shelf life of vessels, especially evacuated devices, made of plastic for the collection of the blood.

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. COMPENDIUM OF THE INVENTION The present invention relates to a container composed of plastic, with multiple coating materials, organic and inorganic, 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, comprising a sequence of coatings, which comprise applied organic and inorganic materials on the first layer, and a third layer of an organic material, applied on the second layer. The first layer, a size coat, is preferably a highly interlaced acrylate polymer. 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 is preferably a sequence of multiple organic and inorganic coatings. Preferably, the sequence of the coatings can be expressed as follows: Second Layer = S (inorganic coating + organic coating + inorganic coating) n where n = 0-10. More preferably, the inorganic coating is a composition based on silicon oxide , such as SiOx, where x is from 1.0 to approximately 2.5; or a composition based on aluminum oxide. More preferably, the organic coating is a highly interlaced acrylate polymer. Optionally, a third layer of a barrier coating, preferably an organic barrier composition, such as polyvinylidene chloride, is more preferably applied on the second layer. Preferably, the first coating is a mixture of monomers of monoacrylate (for example isobornyl acrylate) and diacrylate (for example an epoxy diacrylate or a urethane diacrylate), as described in US Pat. Nos. 4,490,774, 4,696,719, 4,647,818, 4,842,893, 4,954,371 and 5,032,461. whose descriptions are incorporated herein by reference. The sizing coating is cured by a beam of electrons or by a source of ultraviolet radiation. Conveniently, the first layer is formed of a substantially interlaced component, selected from the group consisting of polyacrylates and mixtures of polyacrylates, and monoacrylates having an average molecular weight between 150 and 1.ird , 000 and with a vapor pressure within the range of 1 x 10 ~ 6 up to 1 x 10-1 Torr, at standard temperatures and pressures. More preferably, the material is a diacrylate. Preferably, the thickness of the acrylate sizing coating is about 0.1 to 10 microns and more preferably about 0.1 to 5 microns. A second convenient layer, which is disposed on the first layer, preferably comprises a sequence of multiple coatings, comprising a composition based on silicon oxide, such as SiOx, which is conveniently derived from volatile organic silicon compounds, and the Acrylate The silicon oxide based composition provides a dense, vapor impermeable coating. Preferably, the thickness of the silicon oxide based coating is about 100 i 2,000 Angstroms (Á) and more preferably about 500 to 1,000 Á. A coating above 5,000 A can split and, therefore, not be effective as a barrier. The acrylate supplies a platform for the deposit of the inorganic coating. Preferably, the thickness of the acrylate coating is about 0.1 to 10 microns and more preferably about 0.5 to 3 microns. An optional thlayer may be disposed on the second layer and preferably comprises a polymer of vinylidene chloride-methyl methacrylate-acrylic acid and methacrylate (PVDC), heat-stable epoxy coatings, polymers or parylene polyesters. Preferably, the thickness of the PVDC layer is about 2 to 15 microns and more preferably 3 to 5 microns. The process of applying the first layer to a container is preferably carried out in a vacuum chamber, in which a curable monomer component is dosed to a heated vaporizer system. where the material is atomized and condenses on the surface of the container. Following the deposition of the monomer on the surface of the container, it is cured by suitable means, such as curing by electron beams. The deposition and cure steps can be repeated until the desired number of layers has been achieved.

A method for depositing a coating based on silicon oxide is as follows: (a) pretreating the first layer on the container with a first plasma coating of oxygen; (b) flowing, in a controlled manner, a gas stream that includes an organic silicon compound in a plasma; and (c) depositing a silicon oxide on the first layer, while maintaining a pressure of less than about 500 microns of Hg, during deposition. Although the pre-treatment step is optional, it is believed that this pre-treatment step is provided to improve the qualities of the adhesion between the second layer and the first layer. The organic silicon compound is preferably combined with oxygen and, optionally, helium, or other 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. The PVDC layer is applied to the second layer, by immersion or spraying and then followed by drying by air at a temperature of approximately 50dC. More preferably, the method for depositing a barrier coating on a substrate, such as a plastic collection tube, comprises the following steps: (a) selecting a curable component, which comprises: (i) polyfunctional acrylates or (ii) mixtures of mono-acrylates and polyfunctional acrylates; (b) rapidly vaporizing the component within the chamber; (c) condensing a first layer of a film of the vaporized component on the outer surface of the container; (d) cure the film; (e) vaporizing an organic silicon component and mixing this volatilized organic silicon component with an oxidizing component and, optionally, an inert gas component, to form a gas stream outside the chamber; (f) establishing a radiation discharge plasma within the chamber, from one or more of the components of the gas stream; (g) controllably flowing the gas stream into the plasma, while confining at least a portion of the plasma there; (h) depositing a silicon oxide coating, adjacent to the first layer; (i) repeating steps (a) through (d) above, whereby an acrylate coating is deposited on the silicon oxide coating; and (j) repeating steps (e) through (h) above; thus depositing a coating of silicon oxide on the acrylate coating. optionally, the method further comprises: () immersing the PVDC on the silicon oxide coating. Optionally, steps (i) to (j) may be repeated for about 1 to 10 times, before immersing the PVDC on the silicon oxide coating. 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 second coating layer. Plastic tubes coated with a multiple barrier coating, comprising a size coating, and an oxide layer and an overcoat layer are able to substantially maintain much better vacuum retention, extraction volume and retention of mechanical integrity, compared to the previous tubes comprised of polymer compositions and mixtures thereof, without a coating of barrier materials or tubes comprising only one oxide coating. In addition, the resistance of the tube to impact is much better than that of the glass. More remarkable 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. Also, an adhesive, pressure-sensitive adhesive can be placed over the barrier coating to accommodate several hospital over-labels, for example. Preferably, the multilayer barrier coating of the present invention provides a transparent or colorless appearance and may have printed matter applied to it. An advantage is that the method of the present invention provides a reduction in gas permeability of three-dimensional objects, which we have achieved with a conventional deposit method, typically used with thin films. It has been found in the present invention that the organic acrylate material provides a good platform for the growth of SiOx dense barrier material. It has been found that the highly interlaced layer of acrylate improves the adhesion between a plastic surface and SiOx and, in general, improves the thermomechanical stability of the coated system. In addition, the acrylate sizing coating has a role of a leveling (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 acrylate are also due to the fact that the acrylate is polar and the polarity provides a means for good bond formation between the SiOx and the acrylate. In addition, it has been found that good bonding is obtained between plastic tubes made of polypropylene and acrylate. Thus, the present invention provides the resources to substantially improve the barrier properties of polypropylene tubes. The adhesion properties of both the acrylate 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 an acrylate sizing coating on the surface of the plastic article. The PVDC layer improves the SiOx layer, because it covers its defects and / or irregularities in the SiOx coating. Also, the PVDC coating improves the abrasion resistance of the SiOx coating. A plastic tube resembling the blood collection, coated with a multilayer barrier coating, according to the present invention, will not interfere with the testing and analysis that are traditionally performed on the blood in a 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. Similarly, a plastic blood collection tube coated with the barrier coating is capable of being subjected to automatic machinery, such as centrifuges, and may be exposed to certain levels of radiation in the sterilization process substantially without change in properties optical or mechanical and functional. 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 an amplified diagram, partially in section, of an instantaneous evaporation apeirate.

Figure 7 illustrates a plasma deposit system. Figure 8 is a general schematic diagram illustrating the layers deposited on the 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 illustrates schematically that there are three mnisms for a change in blood 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 one layer of a barrier material. The preferred embodiment includes any component, which are substantially identical to the components of Figures 1 and 2. Therefore, similar components that perform similar functions will be numbered identically to those components of Figures 1 and 2, except that a suffix will be used. "a" for identifying those components in Figure 3. Referring now to Figure 3, the preferred embodiment of the invention, the assembly 20 of the collection tube comprises a plastic tube 10a, having a side wall a, which is extends 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 1 VBAC. The second layer preferably comprises a multiple sequence of coatings, expressed as follows: Second Layer = S (inorganic coating + organic coating + inorganic coating) n where n = 0 - 10.

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, a second layer 56 of a multiple sequence of inorganic and organic materials, such as the oxide. silicon: io and the acrylate, and a third layer 57 of an organic barrier material, such as PVDC. Figure 4 differs from the mode 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 embodiment of Figure 4, except that the suffix will be used. "a" for identifying 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 the external surface of the tube 42a. The multilayer barrier coating 45a includes 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, since it can be displayed over 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 an immersion coating, roller coating or spraying an acrylate monomer or the monomer mixture, followed by the UV light curing process. The material of the acrylate polymer can also be applied to the tube by a process of evaporation and cure, carried out as described in the patent of E. U. A., No. 5,032,461, the description of which is incorporated herein by reference. The evaporation of the acrylate and the curing process involve first atomizing the acrylate monomer into droplets of about 50 microns and then evaporating them and separating them from a hot surface. This produces a molecular vapor of acrylate, which has the same chemistry as the starting monomer. Acrylates are available with almost any desired chemistry. They usually have one, two or three acrylate groups per molecule. Various mixtures of mono-, di- and tri-acrylates are useful in the present invention. More preferably, they are monoacrylates and diacrylates. Acrylates form one of the most reactive classes of chemicals. They heal quickly when exposed to UV light or electron beam radiation to form an interlaced structure. This imparts properties of abrasion resistance and high temperature in the coating. The monomer materials used are of relatively low molecular weight, between 150 and 1,000, and preferably in the range of 200 to 300 and have vapor pressures between approximately lx 10"Torr and lx 10 Torr, at standard temperature and pressure (ie, they are boiling materials). relatively low.) A vapor pressure of approximately lx10"2 is preferred. Polyfunctional acrylates are especially preferred. The monomers employed have at least two double bonds (ie, a plurality of olefinic groups). The high vapor pressure monomers used in the present invention can be vaporized at low temperatures and thus do not degrade (break) by the heating processes. The absence of non-reactive degradation products means that the films formed of these low molecular weight, high vapor pressure monomers have low volatile component levels. As a result, substantially all deposited monomers are reactive and will cure to form an integral film when exposed to a radiation source. These properties make it possible to provide substantially continuous coatings, despite the fact that the film is very thin. Cured films exhibit excellent adhesion and are resistant to chemical attack by organic solvents and inorganic salts. Due to their reactivity, the physical properties and other properties of cured films, formed of these components, polyfunctional acrylates are particularly useful monomeric materials. The general formula for these polyfunctional acrylates is :: OR II Rl - (OC - C = CH2) n I R2 wherein: R1 is an aliphatic, alicyclic or mixed aliphatic / alicyclic radical; R2 is a hydrogen, methyl, ethyl, propyl, butyl or pentyl; and n is from 2 to 4.

Such polyfunctional acrylates can also be used in combination with various onocrylates, such as those having the formula: XJ CH3 (CH2) r- C - (CH2) S - X3 CH20C - C = CH2 • i O R2 where: R2 is as defined above; X1 is H, epoxy, 1,6-hexanediol, tripropylene glycol or urethane; and r, s are from 1 to 18.

O • I CH2OC - C = CH2; and I «2 ? 3 is CN or COOR3, where R3 is an alkyl radical containing 1 to 4 carbon atoms. More often, X3 is CN or C00CH3. The diacrylates of the following formula are particularly preferred: CH2 (CH2) rC? L (CH2) sCH2OC-CH = CH2 I CH2OC-CH = CH2 in which: X1, r and s, have the above definitions. Healing is achieved by opening the double bonds of the reactive molecules. This can be achieved by means of an energy source, such as an apparatus that emits infrared radiation, electrons or ultraviolet. Figure 6 illustrates the process of applying an acrylate coating. An acrylate monomer 100 is directed through a dielectric evaporator 102 and then through an ultrasonic atomizer 104 and into a vacuum chamber 106. The monomer droplets are atomized ultrasonically and they vaporize, where they condense on a rotating tube or film that is loaded onto a drum 108. The condensed monomer liquid is subsequently cured by radiation by means of an electron beam gun 110 .

The second layer of the multilayer 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 vapor deposition with plasma, as it is described in US Pat. 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 A 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 magnets. Preferably, the magnetically improved method for depositing a film based on silicon oxide on a substrate is preferably conducted in a chamber previously evacuated from irradiation discharge from a gas stream. The 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, which are liquid or gaseous at room temperature and have a boiling point of about 0 to 150 ° C, include: dimethylsilane, trimethylsilane, diethylsilane, propylsilane, phenylsilane, hexamethyldisilane, 1,1 , 2,2-tetramethyldisilane, bis- (trismethylsilane) methane, bis- (dimethylsilyl) -methane, hexamethyldisiloxane, vinyl-trimethoxy-silane, vinyl-triethoxysilane, 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 127SC, 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, so as to control adjustably 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 (mTorr) must be maintained during the deposit, and preferably the chamber is at a pressure between 43 and 490 mTorr, approximately, during the deposition of the film. 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 the deposit, because high temperatures of the substrate are avoided for polymers with low glass transition temperature (Tg), such as polypropylene and PET (Tg of -10dC 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 80ac during deposition, that is, the substrate is not deliberately heated.With reference to Figure 7, 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 the plasma polymerization process and is achieved by the flow of the chamber. the process gases, oxygen and trimethylsilane, within 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 placed behind the electrode 200, to create an appropriate combination of magnetic and electric 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. The third layer of the multilayer barrier coating can be formed in the second layer by a dip coating, roller coating or by spraying an aqueous emulsion of the polyindoleyl chloride, or its homo or copolymers, followed by air drying. The third layer may preferably be copolymers of violidene chloride-acrylonitrile methyl methacrylate-methyl acrylate-acrylic acid, thermoset epoxy coating, polymers or parylene polyesters.

Preferably, the third layer is a parylene polymer. Parylene is the generic name for members of the polymer series developed by Union Carbide Corporation. The base member of the series, named parylene N, is poly-p-exylene, 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 (registered trademark of WR Grace and Co.), sold by GRACE, Organic Chemicals Division, Lexington, Mass., USA The third layer of the barrier coating, a polymer material, can be a parylene polymer applied to the second layer by a process similar to vacuum metallization, as described in U.S. Patent 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 spraying an aqueous emulsion of the polymer, followed by air drying of 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.

As shown in Figure 8, the acrylate 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 coatings based on the silicon oxide and acrylate coatings. Although the defects and irregularities are substantially reduced to the minimum with the sequence of the silicon oxide and acrylate coatings, a final coating of the PVDC, E, can be applied over the last silicon oxide coating, to produce a barrier coating complete 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 subjected to automatic machinery, such as centrifuges, and may 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 RECOVERING PLASTIC SUBSTANCES AND SUBSTRATES WITH MULTI-LAYER BARRIER COATINGS An acrylate coating was applied to polypropylene tubes films (substrates) of various thicknesses in one chamber, in which the Tripropylene Glycol Diacrylate (TPGDA) was fed into the evaporator and vaporized instantaneously at about 343ßc on the substrate inside the chamber and condensed. The condensed monomer film was then cured with E-beams by an electron beam gun. The substrate coated with the acrylate coating (TPGDA) after cleaning with a mixture comprising equal parts of a solution of micro-detergent and deionized water (DI). The substrate was rinsed thoroughly in DI water and allowed to air dry. The clean substrate was then stored in a vacuum oven at room temperature until it cooled. 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 / 0 polymerized plasma thin film on the polymer substrate were as follows: Previous Treatment TMS Flow = 0sccm Superficial Base Pressure = 5 mTorr Oxygen Flow = 10 sccm System Pressure = 140 mTorr Power = 50 Watts Time = 2 minutes Fully Oxide Deposition -? "U-jt, od? E ~ TMMS = n0. -7r5e - * 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 The process of applying the acrylate coating, followed by the oxide deposit was then repeated. A top protective coating of a water-based emulsion of the PVDC copolymer was then applied by the immersion coating and cured at 65 ° C for 10 minutes to produce a final coating thickness averaging about 6 microns. EXAMPLE 2 METHOD FOR COATING PLASTIC SUBSTRATES WITH A MULTI-LAYER BARRIER COATING An acrylate coating was applied to polypropylene tubes films (substrates) of various thicknesses in a chamber, in which a mixture of 60:40 isobornyl acrylate: Epoxy diacrylate (IBA: EDA) was fed into the evaporator and vaporized instantaneously at about 343 c on the substrate inside the chamber and condensed. The condensed monomer film was then cured with UV radiation by an actinic light source at 365 nm.

The substrate coated with the acrylate coating (IBA: EDA) after cleaning with a mixture comprising equal parts of a solution of micro-detergent and deionized water (DI). The substrate was rinsed thoroughly in DI water and allowed to air dry. This clean substrate was then stored in a vacuum oven at room temperature until it cooled. The clean substrate was then attached to a support, which was mounted halfway between the electrodes inside 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 / 02 polymerized plasma thin film on the polymer substrate were as follows:.

Previous Treatment TMS Flow = O sccm Superficial Base Pressure = 5 mTorr Oxygen Flow = 10 sccm System Pressure = 140 mTorr Power = 50 Watts Time = 2 minutes Oxide Tank TMS Flow = 0.75 - 1.0 sccm Oxygen Flow = 2.5 - 3.0 sccm System Pressure 90-100 mTorr Power 30 watts Deposition Time 5 minutes After depositing the thin film, the reactor was allowed to cool. The reactor was then opened and the substrate with a multilayer barrier coating was removed. The process of applying the acrylate coating, followed by the oxide deposit was then repeated. A top protective coating of a water-based emulsion of the PVDC copolymer was then applied by the dip coating and cured at 65 ° C for 10 minutes to produce a final coating thickness averaging about 6 microns. EXAMPLE 3 COMPARISON OF L08 SUBSTRATES WITH AND WITHOUT LQ8 MULTI-LAYER BARRIER COATINGS All substrates prepared in accordance with Examples 1 and 2 above, were evaluated in the oxygen permeance (OTR) 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 device (sold by Modern Controls, Inc., 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. The samples were tested at 303C and 0 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% oxygen atmosphere, while the interior of the tube is flooded with nitrogen carrier gas. The tubes were then tested at 20dC 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 IBA: EDA = iso-norbomil: epoxy diacrylate (60:40), UV curing TPGDA = tripropylene glycol diacrylate, cured with E-bundles SiOx coating = 1000 - 3000 Angstroms (as measured by the Scanning Electron Microscope) ) PC = polycarbonate PP = polypropylene Plate = 1905 microns thick Film = 76.2 microns thickness Tubes = nominal wall thickness of 1016 microns 110 = interlazable acrylate, UV curing

Claims (19)

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 an organic coating material of sizing, and a second layer, on the first layer, comprising a sequence of inorganic and organic coatings.
2. 2. The assembly of claim 1, further comprising a third layer on the second layer, including 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 1, wherein the coating of the multilayer barrier includes teeth in correspondence against violations, adjacent to the container interface and closure.
5. 5. The assembly of claim 1, wherein the first layer is a polymerized mixture of mono- and di-acrylates.
6. The assembly of claim 1, wherein the second layer is an inorganic and organic coating sequence, comprising compositions based on aluminum oxide or silicon oxide, and the acrylates.
7. The assembly of claim 6, wherein the sequence of coatings is applied to the first layer, according to the following expression: S (inorganic coating + organic coating + inorganic coating) n where n = 0-10 inorganic coating = aluminum or silicon oxide; and organic coating = acrylates, 8.
8. The assembly of claim 6, wherein the inorganic coating of the second layer is deposited by radiofrequency discharge, direct deposit of ion beams, double deposition of ion beams, electronic deposit, deposit of plasma chemical vapor or magnetically enhanced plasma systems.
9. The assembly of claim 2, wherein the third layer is thermoset epoxy, parylene polymer, vinylidene chloride-acrylonitrile methyl methacrylate polymer-methyl acrylate-acrylic acid, or polyesters.
10. The assembly of claim 1, wherein the first layer comprises polymerized acrylate and the second layer comprises silicon oxide and polymerized acrylates.
11. The assembly of claim 1, further comprising a multilayer barrier coating on the inner surface of the container, having a first layer including an acrylate sizing coating material, a second layer, on the first layer , comprising a sequence of inorganic and organic coatings, and a third layer, on the second layer, of an organic material.
12. 12. A multi-layer barrier coating, which includes: a first layer having an acrylate material; a second layer, on the first layer, having a sequence of inorganic and organic coatings; and a third layer, on the second layer, comprising an organic material.
13. The coating of claim 12, wherein the second layer comprises a sequence of inorganic and organic coatings, including aluminum oxide or silicon oxide compositions, and the acrylates.
14. 14. The coating of claim 12, wherein the third layer is polyvinylidene chloride.
15. 15. A method for depositing a multilayer barrier coating on a plastic substrate, this method comprises: (a) selecting a curable component, which comprises: (i) polyfunctional acrylates or (ii) mixtures of mono-acrylates and polyfunctional acrylates; (b) vaporizing the component instantaneously within the chamber; (c) condensing a first layer of an acrylate film of the vaporized component on the external surface of the substrate; (d) curing the acrylate film; (e) vaporizing an organic silicon component and mixing this organic component of volatilized silicon with an oxidizing component and, optionally, an inert gas component, to form a gas stream outside the chamber; (f) establishing an irradiation discharge plasma within the chamber, from one or more of the components of the gas stream; (g) controllably flowing the gas stream into the plasma, while confining therein at least a portion of the plasma; (h) depositing a silicon oxide coating, adjacent to the first layer; (i) repeating steps (a) through (d) above, whereby an acrylate coating is deposited on the silicon oxide coating; and (j) repeating steps (e) through (h) above; thus depositing a coating of silicon oxide on the acrylate coating.
16. 16. The method of claim 15, further comprising: (k) immersing the PVDC over the oxide coating. silicon.
17. The method of claim 15, further comprising: (k) repeating steps (i) to (j), approximately 1 to 10 times.
18. 18. The method of claim 17, further comprising: (1) immersing the PVDC on the silicon oxide coating.
19. 19. The method of claim 15, wherein the first layer of the acrylate coating is pretreated with oxygen plasma.