Method For The Production of a Coating For The Inner Surface of a Receptacle, and Receptacle Obtained by a Method of Said Type

Abstract

The invention relates to a method for producing a hybrid organo-mineral layer (12) for coating the inner surface (13) of a receptacle as well as to said receptacle for holding products that are biocompatible for humans and/or animals. According to the invention, a solution is formed that contains at least one solvent, water, at least one complexing molecular alkoxysilane precursor, at least one organo-functional molecular precursor and/or silicone, and a catalytic acid, the complexed solution, which is undergoing hydrolysis and condensation, is applied to at least one portion of the inner surface of the receptacle, the applied solution is dried at a specific temperature, and the receptacle is conveyed away and stored.

Claims

1. A process for the manufacture of a neutral hybrid organo-inorganic barrier layer (12) for coating the internal face (13) of a receptacle (15) suitable for containing products biocompatible with man and/or animals, in which: a solution containing at least one solvent, water, at least one first complexing molecular precursor of the family of the alkoxysilanes, at least one second organofunctional molecular precursor and/or silicone, and citric acid as catalyst is formed, the solution thus complexed is applied to at least a part of the internal face (12) of the receptacle, the solution being in the course of hydrolysis and condensation, and the solution thus applied is dried at a predetermined temperature before evacuation of the receptacle and storage.

2. The process as claimed in claim 1, characterized in that the solution comprises at least two first precursors and/or at least two second precursors.

3. The process as claimed in claim 1, characterized in that the solution comprising at least one second precursor and silicone, it also comprises a surfactant.

4. The process as claimed in claim 1, characterized in that the predetermined drying temperature is between 140 C. and 220 C.

5. The process as claimed in claim 1, characterized in that the solvent comprises butoxyethanol and/or ethanol.

6. The process as claimed in claim 1, characterized in that the first precursor is taken from tetraethyl orthosilicate and trimethoxymethylsilane.

7. The process as claimed in claim 3, characterized in that the surfactant is taken from polyethylene glycols with a molar mass of between 1000 and 2000 g.Math.mol.sup.1, polyethylene glycol tert-octylphenyl ether and polydimethylsiloxane.

8. The process as claimed in claim 1, characterized in that the second precursor is taken from the family of dipodal silanes.

9. The process as claimed in claim 1, characterized in that the second precursor is taken from octadecyltrimethoxysilane, 1,2-bis(triethoxysilyl)ethane, bis(3-(trimethoxysilyl)propyl)amine and the family of the fluoroalkylsilanes.

10. The process as claimed in claim 1, characterized in that the solution comprises, for a total volume of 100 units, a mixture of between 58 and 77 units by volume of solvent, said volume of solvent comprising, for a total volume of solvent of 100 units, between 50 and 95 units by volume of butoxyethanol and between 5 and 50 units by volume of ethanol, between 8 and 28 units by volume of first precursor, between 4 and 11 units by volume of second precursor, between 0.3 and 2 units by volume of acid and between 3 and 17 units by volume of water.

11. The process as claimed in claim 1, characterized in that the solution comprises, for a total volume of 100 units, between 62 and 77 parts of solvent, including, for a total volume of solvent of 100 units or parts, 50 to 95 parts of butoxyethanol and from 5 to 50 parts of ethanol, between 6 and 20 parts of first alkoxysilanes precursor, between 8 and 12 parts of organosilanes precursor, between 1 and 14 parts of silicone oil and between 0.3 and 1 part of acid and between 2 and 4 parts of water.

12. The process as claimed in claim 10, characterized in that a pigment and/or functional additive is added to the solution.

13. The process as claimed in claim 1, characterized in that the solution is formed by: a first stage of formation of a first mixture of surfactant and of solvent, and the first mixture is placed under stirring for a first predetermined time, a second stage of formation of a second mixture of solvent and of first and second precursors, and the second mixture is placed under stirring for a second predetermined time, a third stage of dropwise introduction of the acid into the second mixture in order to form a third mixture, and the third mixture is placed under stirring for a third predetermined time, the solution is formed by mixing the first mixture and the third with stirring for a fourth predetermined time.

14. A receptacle (15) suitable for containing products biocompatible with man and/or animals, comprising an internal surface (13), characterized in that said internal surface is covered, over at least a part, with a solidified sol-gel coating layer (12) obtained from a solution containing at least one solvent, water, at least one first complexing molecular precursor of the family of the alkoxysilanes, at least one second organofunctional molecular precursor and/or silicone, and citric acid as catalyst, said coating forming a hybrid organo-inorganic matrix arranged in order to produce at least one chemical barrier.

15. The receptacle (15) as claimed in claim 14, characterized in that the coating layer has a thickness of between 60 and 450 min.

Description

[0109] A better understanding of the invention will be obtained on reading the description which follows of embodiments described below as nonlimiting examples and with reference to the figures which accompany it, in which:

[0110] FIG. 1 is a flow chart showing the stages of a process for the manufacture of a coating layer according to one embodiment of the invention.

[0111] FIG. 2 is an embodiment of a receptacle according to the invention.

[0112] FIG. 3 diagrammatically shows, in section, an embodiment of a device implementing the process according to one embodiment of the invention.

[0113] FIG. 1 shows a flow chart 1 giving the main stages of a process according to the embodiment of the invention more particularly described here.

[0114] The process comprises a preliminary stage (not represented) of supplying with at least one receptacle or bottle to be treated.

[0115] The receptacle is formed of a material which, suitably treated, will make it possible to contain products biocompatible with man and/or animals, that is to say compatible with an ingestion and/or an application to the human or animal body (medicaments, cosmetic products, and the like).

[0116] More specifically, the process comprises first of all or not (test 2) a stage 3 of passivation of the internal face of the receptacle in a way known per se. This is, for example, by filling with an aqueous extraction liquid, for example made of water of R or R.sub.1 grade, then emptying the water after a predetermined time.

[0117] Each of the passivation embodiments (stage 3) can be repeated several times (test 4-5), for example twice.

[0118] This passivation stage further reduces the amount of ions which risk being released subsequently into the content of the receptacle, in particular when the coating layer does not cover all or most of the internal surface of the receptacle.

[0119] It also advantageously prepares the internal face for the adhesion of the coating layer.

[0120] The (optional) passivation stage is subsequently and for example (test 6) followed by a stage 7 of preparation of the support.

[0121] This stage can, for example, be a stage of preheating between 80 C. and 90 C. (for glass or plastic bottles).

[0122] After this stage, a stage 8 of preparation and of formation of a solution according to the invention is carried out, if this has not been carried out beforehand in parallel or otherwise, for example in a separate place and in a period of time before its application which can reach several hours.

[0123] The preparation stage 8 comprises a stage of mixing the constituents of the layer.

[0124] In a first embodiment, the mixing is carried out, for example, in a vat with stirrer at a predetermined temperature and for a predetermined time, for example at a temperature of between 10 C. and 50 C., for example of between 15 C. and 35 C., for example 24 C. (ambient temperature), and mixed for a period of time of, for example, between 10 min and 1 h, for example between 25 min and 45 min, for example 30 min.

[0125] The constituents of the mixture are added substantially simultaneously, the constituents thus being formed of at least one solvent, water, of at least one first complexing molecular precursor of the family of the alkoxysilanes, of at least one second organofunctional molecular precursor and/or of silicone and of a catalyst acid, this being done in proportions which are arranged in order to form, in the end, a solution which is the source of a hybrid organo-inorganic barrier suitable for producing at least one chemical barrier, and which will be described in detail below.

[0126] The mixing stage 8 is followed by (and/or comprises), if the need arises (test 9), an addition (stage 10) of at least one surfactant and/or of at least one pigment.

[0127] There follows a stage 11 of application of the complex solution 12 thus formed (see FIG. 2) to a part of the internal face 13 of the wall 14 of the receptacle 15 to be coated, said solution being in the course of hydrolysis and of condensation. Then a stage 16 of drying the solution, applied at a predetermined temperature depending on the material of the receptacle, is carried out, before a stage 17 of evacuation and storage.

[0128] In one embodiment (FIG. 1A), and for example in the case where the process employs a surfactant, the mixing stage 8 comprises a first substage 18 of formation of a first mixture of surfactant and of solvent (for example 0.5 g of surfactant dissolved in 7 to 10 ml of solvents) g of the final mixture) for a first predetermined time, for example of a few minutes, with alternating treatments with ultrasound.

[0129] It is also possible here to add the silicone, after dissolution of the surfactant.

[0130] A second substage 19 of formation of a second mixture of solvent and of first and second precursor is then carried out, which mixture is placed under stirring for a second predetermined time of greater than 5 min, preferably of greater than 15 min, for example 20 min, when a highly reactive dipodal amine is concerned.

[0131] This will make it possible to have between 8 and 28 parts of alkoxysilane precursor and between 4 and 25 parts of organosilane sources.

[0132] A third substage 20 of dropwise introduction of the acid, for example citric acid, into the second mixture is subsequently carried out, in order to form a third mixture with mixing for a third predetermined time of greater than 10 min, for example 15 min.

[0133] The first mixture is then mixed (stage 21) with a third mixture for a fourth predetermined time of between 3 and 6 h, for example 4 h.

[0134] The mixing proportions and times, and also the rates at which they are carried out, are adjusted according to the characteristics desired for the coating, and in a tailored way within the scope of the person skilled in the art, in order to obtain the hybrid matrix of the desired thickness and the role of the desired chemical barrier for several months and in the light of the extrapolatable results described in detail below with reference to tables I to III.

[0135] As indicated above, the mixing operations are carried out in aqueous liquid which makes possible the hydrolysis of the precursors, and good fluidization making possible easier application.

[0136] The citric acid solution, before introduction into the mixture, has, for example, a concentration of 1.04 mol/l (of between 0.5 and 1.6 mol/l). In the sol prepared, the acid concentration is from 0.05 to 0.3 mol/l.

[0137] The catalysis and the drying, for example at 70 C. for the plastic material and between 140 C. and 220 C. for the glass, for example 180 C., result in a gelling being obtained which gives a solid layer, even without additional curing.

[0138] In the embodiments more particularly described here, the solvent is butoxyethanol or ethanol, the first precursor is tetraethyl orthosilicate (TEOS), the second precursor is octadecyltrimethoxysilane and/or dipodal amine, the citric acid has a concentration of between 3 and 19 parts of aqueous acid solution per 100 parts by value of the total solution, and the silicone, polydimethylsiloxane, has a viscosity of 10 centistokes at 25 C.

[0139] The parameters of the different tests 1 to 20 carried out have been represented in table I below, making it possible to illustrate the excellent results of the invention, in comparison with a crude bottle (test 1reference glass) and a bottle covered with a conventional (nonhybrid) sol-gel layer (test 2) as produced according to the process described below, with butoxyethanol as solvent, just one precursor (TEOS), acid (in this instance citric acid, able to make possible the comparison, although such an acid is not used in a known way as it is not very active in a sol-gel reaction) and polyethylene glycol (PEG) with a molecular weight of 1500 g.Math.mol.sup.1 (as additional solvent).

[0140] The following parameters were subsequently varied: [0141] addition of ethanol as additional and/or complementary solvent (tests 3 to 20) in various proportions while furthermore varying the proportions of the first solvent, i.e. butoxyethanol; [0142] addition of octadecyltrimethoxysilane as second precursor (tests 4 to 20); [0143] the proportions of citric acid (tests 2 to 20); [0144] the drying and its temperature (tests 2 to 20), the latter, however, being chosen, for most of the tests, at 200 C. for 1 hour, in order to make possible the comparison; [0145] addition or nonaddition of a second precursor, in this case a dipodal amine (tests 16 to 20); [0146] addition of silicone (tests 15, 17 to 20); [0147] implementation of a prior drying operation (test 14).

[0148] The results of these different tests (cf. table III) are subsequently examined in the light of the following criteria: [0149] Criterion A: indicating the hold in hours before degradation of the coating at 50 C. in the case of attack on the latter by concentrated citric acid buffered at pH 8 by addition of sodium hydroxide solution (3%, pH 8) (<65 means less than 65 hours) [0150] Criterion B: the hydrolytic resistance (HR) [0151] Criterion C: the mechanical deterioration (observed visually) [0152] Criterion D: the of extractable element or in other words the total amounts of extractables in microgram/l (initials of Inductively Coupled Plasma) [0153] Criterion E: comments.

[0154] The receptacle used is a round 100 ml flask made of type 3 glass (standardized).

[0155] The tests were carried out according to the following protocol:

[0156] Preparation: [0157] 0.1 g of PEG 1500 and the silicone, if the need arises, are dissolved in 2 ml of butoxyethanol (hereinafter also denoted by the abbreviation buto or butoxy) in a beaker with stirring for of the order of 45 min, the time in fact to dissolve the surfactant. [0158] 11 ml of butoxy and the TEOS are introduced into a flask, in order to obtain a second mixture which is left stirring for 20 min.

[0159] It is also at this stage that there will be introduced, for the tests concerned, the 2 ml (or 2.5 ml) of octadecyl, the dipodal amine, if the need arises, and/or the 400 l of dipodal BTSE, and the like. The dipodal BTSE is an organofunctional precursor of formula 1,2-bis(triethoxysilyl)ethane. [0160] After these 20 min of stirring the solution or sol, the amount of aqueous acid solution is introduced therein and mixing is carried out for 15 min. [0161] The mixture of the buto+PEG 1500+the silicone, if the need arises, beaker is then introduced into the sol. [0162] Everything is mixed for 4 h.

[0163] The following are provided for the application of the sol to the internal surface of the bottle: [0164] The sloping or the nonsloping of the bottle with respect to the axis of the nozzle which is in this instance used for the spraying over the wall to be coated. [0165] Its rotating. [0166] The vibrating of the nozzle in order to facilitate the passage and the dispersion of the product. [0167] The control of the flow rate of the product and of the air pressure which can vary during the deposition cycle, carried out in a way within the scope of a person skilled in the art, in order to optimize the application in the light of the other parameters.

[0168] In conclusion, table I gives the characteristics of the tests carried out. Table II gives the additional elements supplementing the characteristics specified in table I for tests 15 to 20 and table III gives the results of the tests for the proportions and mixtures as described in detail in tables I and II.

TABLE-US-00001 TABLE I Octa- PEG Buto Ethanol TEOS decyl Acid 1500 Drying Test ml ml ml ml ml g C. 1 2 14 4 4000 0.1 200-1 h 3 7 7 4 4000 0.1 150 4 16 1 2 2 1000 0.1 200-1 h 5 16.3 1 2 2 750 0.1 200-1 h 6 11.5 6 2 2 600 0.1 200-1 h 7 16.5 1 2 2 500 0.1 200-1 h 8 10.5 7.4 2 2 100 0.1 200-1 h 9 16 1 2 2 1000 (50% 0.1 200-1 h acid) 10 16.3 1 2 750 0.1 200-1 h 11 16.3 1 2 2 750 0.1 200-3 h 12 16.3 1 1.5 2.5 750 0.1 200 13 16.5 1 2 2 500 0.1 200-1 h 14 13.5 4 2 2 500 0.1 200-1 h 15 16 1 2 2 750 200-1 h 16 16 1 2 2 750 200-1 h 17 16 1 2 2 750 0.1 200-1 h 18 16 1 2 2 750 0.1 200-1 h 19 13 1 2 2 750 0.1 200-1 h 20 16 1 2 2 750 0.1 200-1 h

TABLE-US-00002 TABLE II Pre- Dipodal heating amine Dipodal Silicone bottle Drying Test microliters BTSE microliters C. C. 14 80 200-1 h 15 400 200-1 h 16 200 200-1 h 17 200 400 200-1 h 18 50 400 200-1 h 19 125 400 3000 200-1 h 20 200 400 200-1 h

TABLE-US-00003 TABLE III Aging HR Resistance Extractables Comments Test A B C D E 1 3.04 Poor 16 2 0.7 13.03 HR improvement but extractables still high 3 0.41 24.38 Ditto 4 <65 0.08 OK 1.58 Marked improvement 5 <130 0.07 OK 1.29 More homogeneous and stable sol 6 0.36 2.38 Clearer preparation 7 0.3 1.5 Clearer preparation 8 0.45 2.93 Clear preparation 9 <130 0.15 1.72 Homogeneous white sol 10 <130 0.07 OK 1.29 More homogeneous and stable sol 11 <65 0.21 1.29 Excessively long baking 12 0.53 3.02 Too much octadecyl 13 0.3 1.5 Clearer sol 14 200 0.39 OK 2.03 Preheating makes possible a reinforcement of the hold 15 >480 0.45 Silicone makes possible a better chemical resistance but a poorer hold HR 16 <65 0.25 OK 2.78 Coating grainy appearance 17 >415 0.37 OK 1.94 18 <200 0.22 OK Not enough dipodal amine to withstand aging 19 >415 0.26 OK Amount of dipodal amine optimized for resistance and appearance 20 >415 0.34 OK Idem with even better appearance

[0169] Table III shows that the glass alone (test 1) exhibits characteristics of poor resistivity HR and poor extractability (tested in a known way as specified above).

[0170] The glass treated with a conventional sol-gel (tests 2 and 3) exhibits a better resistivity (lower HR) but has, on the other hand, a very high degree of extractability.

[0171] Such results have in particular resulted in a rejection by the user of sol-gel coating techniques in the fields where the absence of contamination is highly desired, even if a drying at 200 C. (test 2) makes it possible to improve the results.

[0172] With tests 4 to 20, where a second precursor (octadecyltrimethoxysilane) in addition to the first precursor (TEOS) is provided and a first solvent (butoxyethanol) and a second solvent (in a ratio of 1.5 to 16), namely ethanol, excellent results are obtained as regards HR and extractability.

[0173] The mechanical strength is satisfactory overall.

[0174] However, it should be noted that, in tests 4 to 8, where the amount of first solvent is varied, better results are obtained by increasing the proportion, everything otherwise being equal, of butoxyethanol, and also by varying the amount of acid.

[0175] Test 14 shows the usefulness of a preheating, in comparison with the absence of preheating (test 13), on the hold.

[0176] Tests 15 and 17 to 20 show the sizable improvement which is brought about by the addition of silicone, in particular in combination with the addition of a second precursor (the dipodal amine), for a better hold with regard to aging with citric acid, tests 18 to 20 (compared with test 17) demonstrating, however, that a sufficient amount of second precursor (dipodal amine or dipodal silica) is necessary if it is desired to improve the resistance to aging.

[0177] In all these embodiments, the first molecular precursor is tetraethyl orthosilicate, known to a person skilled in the art under the abbreviated name TEOS, and the catalyst is citric acid.

[0178] Advantageously, the solvent and the first precursor are mixed, and then the second precursor and the citric acid, the amount of water for dissolution of the citric acid being sufficient and/or calculated in order for there to be no other contributions of water.

[0179] In one embodiment, additives appropriate for performing a function are added to the mixture.

[0180] The functions can be to block content-container and environment-content interactions, such as to limit the release, to color or add visual effects to the layer, to block radiation (for example UV radiation), to capture oxygen, to modify the surface activity or energy in order to influence the factors for sliding the product over the wall of the receptacle, to capture oxygen-containing compounds and/or oxygen, to render secure in biological terms (biocidal function, antibiotic function and the like).

[0181] These functions are produced by addition, to the sol-gel, in solution, of elements taken, for example, from the group SiO.sub.2, colored pigment, cerium oxide and/or silver.

[0182] The amount added is correlated with the nature of the desired function. For example, a blocking function can be produced by addition of SiO.sub.2 in a concentration, for example, of between 3.5 g.Math.l.sup.1 and 20 g.Math.l.sup.1, for example of between 4.5 g.Math.l.sup.1 and 18 g.Math.l.sup.1, and/or a biocidal function can be produced by an addition of silver in a concentration, for example, of between 0.9 g.Math.l.sup.1 and 2.5 g.Math.l.sup.1, for example of between 1.1 g.Math.l.sup.1 and 2.2 g.Math.l.sup.1.

[0183] After this stage, which is not obligatory, the process according to the embodiment of the invention more particularly described here comprises stage 11 of application of the solution in the course of gelling, for example to at least a part of the internal surface of the receptacle concerned, for example , and/or for a predetermined design (letters, name of products, logos, and the like). The application thus forms a coating layer on said portion of the internal face.

[0184] The coating solution or gel is then evenly affixed to the internal surface of the receptacle, such as to obtain a deposited layer of a substantially identical even thickness at the chosen spot.

[0185] Stage 11 can be carried out in several ways and an embodiment of a device for application of the layer according to the invention will more particularly be described with reference to FIG. 3 in a way which is in no way limiting.

[0186] The application can be carried out immediately subsequent to the formation of the solution, after the start of the gelling or may be delayed.

[0187] With respect to an end of the stage of preparation of the solution at a moment t0, the application can start, for example, at a predetermined moment t0+h, h being a duration in hours.

[0188] As the gel is substantially the same temperature as that of the formation of the solution, the person skilled in the art will adjust the duration and the conditions of storage, transportation and/or preparation before application of the postponed substance in order to obtain the rheological conditions (viscosity, coupling rate, adhesion, and the like) which are optimum and/or desired for the application envisaged, by noting that the change in viscosity follows the change in the duration.

[0189] For example, at ambient temperature, h is less than 10 h, for example less than 6 hours, for example 3 h.

[0190] If the gel is preserved at a predetermined temperature lower than the formation temperature, as the kinetics of the change in its physicochemical characteristics is then reduced, it may be preserved for a subsequent application for several weeks.

[0191] For example, the duration of preservation before use may be a predetermined duration of less than 4 days, for example of less than 3 days, for example of less than 2 days, in the case of the use of citric acid.

[0192] The temperature is then, for example, less than 10 C.

[0193] After the application stage, there follows stage 16 of drying the gel thus applied at a predetermined temperature and for a predetermined time.

[0194] In one embodiment, the receptacles comprising an opening are placed in the vertical direction with the opening at the bottom, so as to evacuate the excess solution applied.

[0195] The receptacles are dried in an oven, for example a ventilated oven, at a predetermined temperature and for a predetermined time.

[0196] If the constituent material of the receptacle is glass, the temperature is, for example, between 140 C. and 220 C., for example 200 C., for a drying time of between 15 min and 3 h, for example between 30 min and 2 h, for example 1 h, at 200 C.

[0197] If the constituent material of the receptacle is plastic, the temperature is, for example, between 15 C. and 90 C., for example at 80 C. (for 1 hour), for a drying time of between 10 min and 120 min, for example 60 min.

[0198] The drying depends on the nature of the solvent, the drying time and temperature having to be adjusted to the latter. In particular, the temperature has to be greater than the boiling point of the solvent at a predetermined pressure.

[0199] In another embodiment, the drying is carried out for a duration and at a temperature which are mentioned above but the receptacles are placed in an oven of known type.

[0200] The successive stages of application of the solution forming coating product to a part of said internal face, of evacuation of the excess coating solution and of drying the product can be repeated a predetermined number n of times.

[0201] The number n is, for example, greater than or equal to two, for example greater than or equal to three, that is to say that the stages are repeated at least three times.

[0202] Once dried, the receptacle is brought back to an ambient temperature along a predetermined temperature curve.

[0203] The curve of rise in temperature of the receptacle can be linear or stepwise, and for example, follows an affine curve, for example, in order to dry the receptacle up to the maximum drying temperature selected, the director coefficient of the (heating) temperature curve being between 2 C./min and 5 C./min.

[0204] The fall in temperature is, on the other hand, left free in order to be slow and to consequently prevent cracks on the coating layer, to cause good adhesion and to limit the differential expansion stresses of the layer and of the wall of the receptacle.

[0205] Subsequently, the same reference numbers will be used to denote identical or similar elements.

[0206] FIG. 3 shows a device 22 for coating 12 at least a portion of the internal surface 13 of a receptacle 15, according to the embodiment of the invention more particularly described here.

[0207] The receptacle 15 is, for example, a cylindrical bottle made of glass extended around an axis O.sub.z. It comprises, at one of its ends (top end), an opening as a bottleneck. The opening of the bottleneck comprises a neck C with a smaller diameter than that of the receptacle or bottle.

[0208] The receptacle thus substantially forms a chamber.

[0209] The device comprises a support S of the receptacle, for example comprising a retention clamp M in the shape of a dish or of a U, the branches L of which grip the base, that is to say the bottom, of the receptacle fixed via lateral screws (not represented).

[0210] Means 23 for rotating the receptacle around its axis O.sub.z at a predetermined speed V are provided which are known per se. The speed V can be unchanging or variable and regulated. More specifically, the means comprise, for example, a rotating rod for driving the support which extends along the axis O.sub.z and a motor for driving in a way known per se.

[0211] Means 24 for insertion/extraction (arrow 25) of a spraying tool or nozzle 26 inside the receptacle are mounted on a frame B, as dot-and-dash lines in the figure, on the side of the bottleneck of the receptacle 15.

[0212] The nozzle 26 comprises a longitudinal shaft or tube 27 connected, at its end, to the insertion means 24 comprising an actuator 28 for longitudinal displacement, such as a jack.

[0213] The action of the jack, which is integral with the nozzle 26, relocates the latter from an initial position external to the receptacle 13 to its positions (for example which can vary according to a predetermined coating program) of operation internal to the receptacle along the axis O.sub.z.

[0214] It thus makes possible a gradual descent, continuous or stepwise, of the tool for application of the coating solution (gel in formation) to the internal surface of the receptacle.

[0215] A sequence of points or lines with times and speeds adjusted in order to match the shape of the bottle can be employed in addition to and/or as replacement for the rotational movements.

[0216] The nozzle brings about vaporization 30 along a predetermined solid angle for dispersion which depends on the ejection rate and pressure controlled in a way known per se.

[0217] The tube is connected, at its opposite end, to a system 31 for dispensing a liquid coating solution according to the invention to be sprayed comprising means 32 for feeding the liquid or substantially liquid solution 33 in order to make possible the spraying, at a predetermined flow rate D.

[0218] The system 31 thus comprises a tank 34 for storage of said liquid and means 35 for moving the liquid (metering pump) arranged in order to regulate the flow rate D of the liquid via a calculator 36 and also controls the other actuators employed in the device.

[0219] The tank comprises, in its bottom, a mixing means, for example a stirrer (not represented).

[0220] The coating gel is thus the curable liquid hybrid coating material obtained by the process according to the invention and in particular according to the embodiment of the invention more particularly described above.

[0221] The device also comprises means 37 for heating the receptacle 13 known per se which make possible the rise in the temperature of a part of the internal surface of the receptacle up to a predetermined temperature threshold for drying.

[0222] More specifically, the heating of the internal surface is carried out, for example, by direct radiation from heating resistors 38 positioned outside the receptacle or by diffusion around the wall of the receptacle positioned in contact, for example, with a heating muffle (not represented).

[0223] In one embodiment, the receptacle and the resistor are substantially confined in one and the same chamber so as to form an oven for homogeneous heating of the receptacle.

[0224] The device also comprises a computer or automaton 39 for digital control comprising the calculator 36.

[0225] These are connected via a data bus 40 and in a way known per se to the actuators of the device, namely to those of the retention clamp of the receptacle, that is to say of the motor for driving in rotation, to those of the means 24 for insertion of the nozzle 26 into the receptacle (jack), the stirrer, and also to those of the means 35 for moving/feeding with liquid (pump, valve, nozzle) and heating means 37 (electrical resistors).

[0226] The calculator 36 is arranged in order to calculate, from the different set points imposed, a law for controlling each of the actuators in a way known per se.

[0227] As is obvious and as also results from the above, the present invention is not limited to the embodiments more particularly described. On the contrary, it encompasses all the alternative forms thereof and in particular those where the device implementing the process is different.