SE459967B - STRUCTURAL COATING OF A GLASS TYPE, CERAMIC OR DINNER SUBSTRATE OR SUBSTANCES AND PROCEDURES FOR ITS PREPARATION - Google Patents

Description

In a wide-ranging aspect, the invention provides a method of forming a structural coating (as defined herein) on a glassy, ceramic or porcelain substrate or substrate to thereby protect and reinforce the substrate, comprising the steps of applying a coating material containing free iso- cyanate groups on the substrate and subjecting the thus coated substrate to treatment with a desiccant at room temperature, the desiccant being in vapor phase and being: (a) ammonia, an amine or an alkanolamine; or (b) a multicomponent agent comprising (i) water and (ii) an additional component selected from an amine, alkanolamine or other hydratable compound.

More particularly, the invention provides a method of forming a structural coating (as defined herein) on a glass bottle to thereby protect and reinforce the glass bottle, comprising the steps of applying a one-component coating material containing free isocyanate groups to the surface of the glass bottle and thus exposing the coating. the bottle for treatment with a desiccant at room temperature, the desiccant being: (a) in vapor phase and (b) a multicomponent agent comprising water and an amine.

In a further aspect, the invention provides a structural coating (as defined herein) comprising a coating material containing free isocyanate groups applied to a glassy, ceramic or porcelain substrate or substrate and then dried at room temperature by a steam phase desiccant, 459 967 the drying agent is: (a) ammonia, an amine or an alkanolamine; or (b) a multicomponent agent comprising (i) water and (ii) an additional component selected from an amine, alkanolamine or other hydratable compound.

In a further aspect, the invention also provides a glass bottle, the surface of which is protected and reinforced by a structural coating (as defined herein), the coating comprising a one-component coating material containing free isocyanate groups applied to the surface of the bottle and dried then at room temperature by means of a drying agent, which is: (a) in the vapor phase and (b) a multicomponent agent comprising water and an amine.

For the purposes of the description, the following should be understood: 1. In the case of a structural coating, retaining film or the like which is to be subjected or has been subjected to the process according to the invention, the term "drying" is to be understood as (i) including within its scope "curing" and the like. (ii) indicating that the coating is either free of "tack", insoluble in solvents, possessing a far-reaching degree of integrity or capable of withstanding reasonable abrasion or reasonable pressure without damage. It should also be understood that a dry coating may exhibit some or all of the foregoing qualities. »B 459 967 2. The term" substrate "refers to an article or article surface which may be structurally reinforced and / or stabilized by the structural coating of the invention.

The substrate is glassy, ceramic or porcelain in nature. The term "coating material" refers to a material which, after application to the substrate and treatment with the drying agent, will contribute to the formation of the structural coating according to the invention. The material contains isocyanate groups, may be of the one-component type and may include solvents, additives or additives and / or one or more surfactants as desired.

It can be clear, transparent or opaque. 4. The term "structural coating" refers to a coating (such as an organic coating) that functions to protect, reinforce and contain (by enclosing or otherwise) a substrate to which the coating is applied. The coating is provided by the coating material as defined above and is effective at reduced thicknesses not previously considered possible, i.e. thicknesses in the order of 10-20 microns. This does not mean that the invention is limited to coatings or coated substrates, where the thicknesses are of this order of magnitude (the invention is not as limited as will become apparent hereinafter). What is simply meant is that the coating is effective at such reduced thicknesses. The term "structural coating" is for the purposes of this invention to be understood as synonymous with "retentive film" (or the like).

. The term "desiccant" refers to the chemical compound or compounds which effect curing or drying of the coated material. The term may sometimes in this text alternatively be referred to as a catalytic agent or simply as a catalyst.

The drying (or catalytic) agent may be ammonia, an amine or an alkanolamine. In another embodiment of the invention, it may be a multicomponent agent (eg a bicomponent agent) comprising water as the first component together with at least one further compound selected from an amine or alkanolamine or any other hydratable compound which, in combination with the water , will accelerate the desired function.

It is believed that the water and the additional component (s) cooperate, or co-react, to form a hydrated complex type agent, which agent is thereby effective for drying the coated material at an accelerated rate and thereby for structurally strengthening the substrate. , on which the material has been coated.

It was, of course, known to coat glass bottles prior to the present invention. However, the prior art coated bottles have always been characterized by coatings of considerable thicknesses and / or have required heat to perform the coating process. Although the bottles thus coated were reasonably satisfactory in terms of use, they tended to have an improper coating thickness as well as a tendency to falter if the storage, transport and use conditions were other than ideal to make the bottles unattractive to users. In addition, there was a clear need for refinement and improvement in coating procedures.

It was also known to coat certain substrates with coating vehicles containing curable groups and to dry the vehicles in the vapor phase. However, the known procedures were not related to the fields to which the present invention pertains. The coating of the substrates defined herein in accordance with the process described herein had never been contemplated before, and consequently the surprising results obtained by the present invention could not have been foreseen either.

As briefly stated above, we have discovered that special substrates, coated in accordance with the invention, receive a dramatic improvement in certain functional properties. We have especially discovered that thus coated glass bottles not only obtain these improved properties but also quite unexpectedly do so at coating thicknesses which were not previously considered possible. A glass bottle coated according to the invention coated in accordance with the invention is thus capable of achieving a higher degree of acceptance among the users. In connection with this, the coatings, which are capable of being dried quickly at room temperature, can be applied in a more efficient and economical manner than is the case with thermal application. In addition, the coatings of the present invention are applied as liquid coatings, which have significant practical advantages in addition to powder coating coatings, which are also abundant in the prior art.

The current situation in the glass bottle industry is such that a uniform level of technology in the field is generally available to manufacturers all over the world. The same techniques, processes, raw materials, intermediates and the like were thus used to produce a similar type of product. A thin protective structural coating such as that provided by the present invention and having a high degree of abrasion resistance, improved tensile strength and ability to achieve excellent adhesion to a cross section of glass or ceramic substrates, opens up enormous possibilities for the glass container industry. When linked to this the fact that the compositions described here can be cured at room temperature within minutes, it is realized that the invention represents a dramatic advance - capable of large-scale industrial application - 459 967 in the glass bottle industry.

Once the structural coating has hardened, it adds increased strength against blasting or breakage to a glass container, lowers the possibility of surface scratching and, in case of breakage, it retains a larger percentage of glass fragments within an intimate proximity to the breaking point. An associated consequence is that bottles can be made of thinner glass (and thus lighter in weight) with the resulting economic benefits.

In the foregoing description, structural reinforcement of the substrate has been mentioned. Although it is emphasized that the description should not be construed as bound by any particular theory of function, it is nevertheless assumed that the increase in the breaking strength of a glass container, coated in accordance with the invention, may be due to the following: - (a) the filling by the liquid the coating material of any surface cracks or other defects, whereby the entire container after curing is structurally reinforced; and (b) the elimination of water molecules from such surface cracks or other defects by the reactive groups contained in the coating material, thereby providing a completely anhydrous surface, which in turn prevents the spread of further surface defects.

The invention will now be described with sequential reference to (i) preferred subgeneric behavioral features and (ii) specific detailed examples. It is to be understood that the following description is merely illustrative of the invention and is not to be construed as limiting.

The coating is advantageously of one-component type (or single-vessel type) containing free isocyanate groups. The term 4,596,967 "free isocyanate groups" includes within their scope such potentially free groups, the meaning to be given is that the prepolymer has isocyanate groups which are releasable or available for reaction with water molecules or any other compound having active hydrogen sites. (for the purpose of polymer spreading and / or film formation). Compounds containing free isocyanate groups should be understood as encompassing all such compounds.

Accordingly, this includes not only isocyanates with urethane structure and polyisocyanates but also those with polyisocyanurate, biuret, allophanate and urea structures! .

Particularly preferred isocyanate-containing coating materials are toluene diisocyanate (TDI) prepolymers, xylene diisocyanate (XDI) polymers (hydrogenated or other) and mixtures thereof and based thereon. Others include prepolymers of 4,4'-diisocyanatodiphenylmethane (MDI), trimethylhexamethylene diisocyanate (TMDI), hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI) and suitable mixtures thereof.

Certain additives in usually minimal amounts (eg trace quantities up to 2%) can also be used to advantage in the composition to achieve the optimum degrees of adhesion to the substrate or to modify, as required, the rheological properties. of the coating to facilitate its application procedure. Adhesion promoters are typically silane-based compositions, exemplified by -glycidoxypropyltrimethoxysilane. Additional additives may include flow promoters / surfactants, wax emulsions and water purifiers, which are exemplified by silicone-based compositions, polyethylene wax emulsions and monofunctional iso- (9,459,967) cyanates and molecular sieves, respectively. Additional additives may include organometals and inorganic salts in turn exemplified by the respective dibutyltin dilaurate, lead tetretyl, titanium acetylacetonate, dimethyltin dichloride, stannous and zinc octoates and bismuth nitrate and ferric chloride.

As stated above, the coatings and coated substrates of the present invention are effective at reduced thickness - with resulting benefits as indicated.

Typically, but not necessarily, the thicknesses may be in the order of 10-20 microns (eg, 15 microns). Depending on the special circumstances and requirements, however, thicker coatings (eg in the order of 40 microns) can be applied. However, it should also be understood that coated substrates can be recoated to any desired thickness.

As indicated, the drying agent (or the catalytic agent) may be ammonia, an amine or an alkanolamine. Alternatively, it may be a multicomponent agent with the additional components as set forth above. The desiccant effects its treatment in vapor phase. When the agent is a multicomponent agent, the additional component can first be complexed with water molecules listed above (to form an hydrated complex type agent). The term "meadow phase" is intended to indicate that the desiccant is in gaseous, meadow or any other incorporated airborne form (eg dispersion, mist or aerosol) in which it is available for reaction. The drying operation does not require heat but is performed at room temperature.

The term "amine" includes within its scope not only those with simply primary aliphatic monofunctional structure but also amines characterized by (i) polyfunctionality and (ii) a more advanced degree of hydrogen substitution. In the case of tertiary amines, these may be (a) 459 967 polyfunctional, (b) aromatic, (c) aliphatic or cycloaliphatic in nature.

The amine itself can be exemplified within wide limits. Thus, typical examples are mono compounds such as methylamine, ethylamine, propylamine, isopropylamine and the myriad isomers of butylamine and polyfunctional amines such as hydrazine, ethylenediamine, propylenediamine and diethylenetriamine. Further examples are diethylamine, triethylamine and dimethylethanolamine (DMEA) and ditertiary amines such as N, N, N ', N'-tetramethylethylenediamine (TMEDA) and N, N, N', N ', 2-pentamethyl-1,2-propanediamine ( PMT), and any combination of such amines, proportioned as required, whereby advantage can be taken of the synergistic effect of such a combination.

Particularly preferred desiccants are dimethylethanolamine (DMEA), N, N, N ', N'-tetramethylethylenediamine (TMEDA) and N, N, N', N'-2-pentmethyl-1,2-propanediamine (PMT).

The term "steam phase" has been defined above. When the drying agent is a multicomponent agent, this phase is advantageously obtained by atomizing or atomizing predetermined quantities of water and a selected additional component. The concentrations of water and the additional component can be varied according to situational requirements. For example, the drying can be carried out at 45-85% relative humidity, eg 65%, at a temperature in the range 20-30 ° C (eg ZSOC). The concentration of desiccant (or catalytic agent) may vary according to the additional component selected. Thus, in the case of DMEA, the concentration is advantageously in the range 1200-1800 ppm, for example 1400 ppm. For DMI and TMEDA, the respective preferred ranges are 700-900 ppm (more preferably 800) and 800-1000 ppm (more Treaty 900). q 459 967 The coating material can be applied to the substrate by any conventional measure (spraying, dipping, ironing, brushing) capable of applying a film / coating to a surface in a uniform manner and to specific wet film thicknesses. Once the coating material has been applied, it can be treated in accordance with previously developed procedures.

Initial tests performed on glass containers coated according to the invention indicate that the surface of such a container has a simply adjustable coefficient of friction. Further experiments show that the coated glass containers are better able to withstand the harsh treatment to which glass containers are subjected in conventional operations at transport lines, container filling and the like. Thus, a filled container in a transport line during movement is less likely to "jump out" of its position or be wedged by excessive friction. In addition, adjacent surfaces of glass containers can be worn against each other for much longer periods under increased pressure without adversely affecting the containers by matting, splitting, scraping or scratching, circumstances which currently occur during the transport of these articles over long distances.

In a further experiment, a liter bottle coated with a structural coating as described herein was found to exhibit greatly improved fragment retention properties when the bottle was dropped on a hard surface from a height of one meter. All these tests and trials will be performed and explained hereafter. 12,459,967 The coatings of the invention exhibit remarkably good integrity over a multifaceted range of exposure conditions. They are completely solvent-resistant and do not show any change in characteristics after rigorous cleaning (eg 20 commercial dishwasher cycles). The ability of a coated glass container to withstand rigorous cleaning will also be demonstrated hereinafter.

A further advantage is demonstrated when a glass container, coated in accordance with the invention, is recovered. Since it is possible to volatilize the coating (eg in a melting furnace), uncontaminated glass can again be made available for molding. The invention thus does not involve any loss of recyclable glass. Nor is it necessary to separate clear glass from colored glass.

We now proceed to specific detailed examples, which demonstrate both (i) the formation of the protective structural coating on the substrate and (ii) the testing of this protected and reinforced substrate. When abbreviations may require demanding explanations, such explanations are given. When one or more ingredients are generally known by the trade name or names under which they are commercially available, the trade name is given. Otherwise, the terminology is the standard terminology in technology.

EXAMPLE 1 A clear coating material for coating glass bottles was composed as follows: - Component parts by weight Toluene diisocyanate prepolymer 56.5 Aromatic hydrocarbon solvent 40.0 (an aromatic naphtha with a high flash point and commercially available under the trade name "Solvesso 100" l 13 459 967 Silicone-based flow-promoting 2.0 agent (product known commercially as "BYK 300") Silane-based adhesion-promoting 1.0 agent (product known commercially as "Sílan A 187") Wax emulsion (polyethylene wax) 0.5 The coating material was sprayed from a conventional siphon vessel spray gun. an application viscosity of 18 seconds FORD Cup No. 4 on a fresh (ie freshly made) glass bottle rotating on a turntable inside a conventional spray cabinet or casing.The coating was applied to the outer surface of the bottle to give a thickness equal to approximately 15 microns dry film.

The bottle was then placed in a drying chamber and exposed to a slightly turbulent air flow (air movement 1.5 m / sec) containing a concentration of DMEA of 1400 ppm at 25 ° C, 65% relative humidity. After exposure to this treatment for 1 minute, the chamber was evacuated and fresh air was circulated around the chamber for a post-cure period of 3 minutes.

The resulting coated bottle exhibits all the improved properties specified above. These will be demonstrated in the following examples.

EXAMPLE 2 An opaque, white coating material for coating glass bottles was formulated as follows: Components Weight Parts Xylene Diisocyanate Prepolymers 50.0 Titanium Dioxide (Pigment) 20.0 Inert Abrasive Resin for Pigment 5.0 ("Durasol 310") Ester Solvent ("Corsol EEA") ) 23.8 Pigment Moisturizer 1.0 ("Additive TI") Surfactant ("BYK 300") 0.2 The coating material was sprayed through a conventional siphon spray gun at an application viscosity of 16 seconds FORD Cup No. 4 on a fresh glass bottle rotated. The coating was applied to the outer surface of the bottle to give a thickness equal to approximately 15 microns of dry film.

The bottle was then placed in a drying chamber and subjected to drying in the manner and under the conditions set forth in Example 1. The finished product was characterized by excellent opacity and a surface with attractive gloss. In addition, the coated bottle exhibits all the improved properties specified above.

EXAMPLE 3 Introduction- Eight fresh glass bottles were taken from a bottle making oven with only the conventional stannous chloride coating applied to the hot end. Eight identical additional bottles were taken from the furnace, but in this case a conventional cold end coating of polyethylene wax had also been applied. These bottles will be compared in Example 6 here. 459 967 The eight unwaxed bottles were placed on a transport line to transport them through a side-by-side spray casing and in front of an electrostatic turbo head applicator.

The applicator applied a transparent green coating material composed as follows Component parts by weight Toluene diisocyanate prepolymers 50.0 Aromatic hydrocarbon solvent 37.0 (as in Example 1) Methyl ethyl ketone solvent_ 3.0 Organic green dye 1.5 (S fl vinyl Green GLS) Silicone (as in Example 1) Silane-based adhesion promoter 1.0 (as in Example 1) Wax emulsion (as in Example 1) 0.5 The coating material was applied via the electrostatic turbo hood to give a wet film thickness corresponding to approximately 15 microns dry film. The coated bottles (which had been rotated and which also had metal probes inserted) continued on the conveyor line through an air curtain and into a permeation zone. In the zone, controlled conditions of 25 ° C, 65% relative humidity and 1400 ppm DMEA (air movement 1.5 m / sec) were maintained.

Transport time for the bottles was arranged to give one minute permeation under these conditions.

The bottles are then passed through an air curtain and into a post-curing air movement for a period of three minutes. When the bottles were removed from the conveyor line, they were completely dry, free of solvent odor and showed the improved properties specified above. EXAMPLE 4 An opaque, etched, amber coating material was formulated as follows: Component Parts by weight Xylene diisocyanate prepolymers 25.0 Hydrogenated xylene diisocyanate prepolymers 25.0 Aromatic hydrocarbon solvent 17.0 (as in Example 1) (derived from Savinyl dye material) Silica 20.0 Silane-based adhesion promoter 1.0 (as in Example 1) Wax emulsion (as in Example 1) 0.5 This coating material was applied in the manner set forth in Example 2. Drying was performed as in Example 1. The bottles thus coated again showed the advantageous properties stated above.

EXAMPLE 5 A clear coating material was formulated according to the following Component Weight Parts Xylene diisocyanate prepolymers 28.25 Hydrogenated xylene diisocyanate prepolymers 28.25 Aromatic hydrocarbon solvent 40.0 (as in Example 1) .0 fr (as in Example 1) U1 Wax emulsion (as in Example 1) 0, 459 967 The coating material was applied as in Example 1.

In this case, drying was performed using PMT at a concentration of 800 ppm. The other drying conditions (temperature, etc.) were as in Example 1. The coated bottles again showed the advantages of the invention.

EXAMPLE 6 The burst strength properties of the two groups of cylinders listed in Example 3 were compared by subjecting them to AGR ramp pressure tests using an AGR ramp pressure tester. Prior to performing the test, the bottles were run for seven minutes on an AGR line simulator.

The results are tabulated below.

Noterz- 1. AGR is an acronym recognized in the art for American Glass Research. An AGR line simulator is a standard device that enables an observer to approximate the effect on bottles of the type of treatment to which the bottles are subjected during their lifetime in normal carrier-type filling operations, etc. The longer the simulation time, the more stressful treatment. 3. The ramp pressure test / tester is also well known in the art. The test is performed with the bottles filled with water.

The tester progressively increases the pressure over time until breakage occurs. The pressure at break is registered.

TABLE ii PRESSURE AT BÉOTT (KG PER SQUARE CENTIMETER) KG / CM2 18 459 967 Bottle 1. Tin chloride 2. Tin chloride% improvement plus P.E. Wax plus coating Carbon.2 over according to the invention carbon 1, 20.5 40.4 97 '° 2. 23.5 34.5 46'3 3. 25.6 33.4 3 °' 7 4. 15.9 40.5 l54'4. 18.9 40.2 ll3 '°, 23.3 33.9 45' ° 7, 19.5 35.9 84'3 3, 14.5 31.8 ll9'7 AVERAGE 20.2 kg / cmz 36, 3 kg / cmz 79'6 The bottles in the first column (not coated in accordance with the invention) give an average breaking pressure of 20.2 kg / cm2However, the second column (bottles coated in accordance with the invention) shows an average breaking pressure of 36/3 kg / cmz. This represents a highly significant improvement in performance and thus clearly demonstrates a dramatic increase in rupture strength.

EXAMPLE 7 Fragment Retention: A bottle coated in accordance with Example 1 and again coated to give a dry film thickness of 35-40 microns was filled with water and released from a height of 1.5 meters to land on a steel plate 6 mm thick. The test required that the plate be set at an angle of 40 relative to the substrate so that the resulting seam would be directed towards a piece of soft carpet. The purpose was to ensure only one direct shock per case. 459 967 A control bottle (not coated in accordance with the invention) was filled and similarly tested.

The control bottle disintegrated on impact with total loss of contents. The bottle according to the invention showed - no perceptible structural rupture.

EXAMPLE 8 Bottles coated in accordance with the invention exhibit excellent sliding characteristics (referred to in the art as lubricity). This is demonstrated by means of a standard sample, in which three bottles are arranged pyramidally - two below, one above - and skewed until the upper bottle is induced to slide. The results obtained when the sample was applied to three groups of bottles (two control groups, one group of bottles according to the invention) are tabulated below: - TABLE III LUBRICITY / SLIDING ANGLE BOTTLE TAP Sliding angle degrees Fresh flint glass 30-35 Standard waxed glass according to example Bottle 2 11-13 By suitable variation, of course, the result with bottles coated in accordance with the invention can be adjusted as required. The improved characteristics shown by the bottles according to the invention can eliminate the need for stearate or other lubricating sprays currently used to facilitate the movement of bottles on conveyor filling lines_ i-gßßxvßi 9 Refinishing: Three groups of unblemished 750 ml bottles, six in each group , were prepared as follows: - 459 967 Group A was not subjected to any preliminary treatment (these are referred to as standard bottles). Group B was provided with a 25 cm scratch, made with a glass cutter, midway between the shoulder and the foot of the bottles. Group C was similarly scratched and additionally coated to a thickness equivalent to 30 microns dry film, with the coating of Example 5.

The bottles were then subjected to the AGR ramp pressure test explained and described in Example 6. The results, in kg / cm 2, are tabulated. STANDARD REPAIRE REPADE AND COATED è i F. E 1. 26.0 8.5 21.8 2. 33.1 26.1 30.5 3. 13.9 14.8 22-0 4. t 41.0 14.7 15.9. 27. o 20. 1 20. 6 6. 33.5 17.2 17.3 Yarn section 29.1 l6.9 21.4 The results above show a significant improvement with regard to the bottles in column C compared with the bottles in column B.

Thus, bottles coated in accordance with the invention were capable of significantly approximating their original properties.

.EÄFEEÉ L I Q A batch of bottles coated according to Example 2 (XDI) was treated as follows: - (a) Immersion in 2% caustic soda at 85 ° C for 15 minutes. (b) Immersion in 6% caustic soda at 85 ° C for 15 minutes.

No changes in gloss, color or adhesion were detected. This example shows that bottles coated in accordance with the invention will be capable of withstanding the type of rigorous cleaning to which they would be subjected in normal use. Washing with caustic soda is an orthodox practice in breweries for cleaning used beer bottles.

EXAMPLE 1, 1 Batch of bottles coated in accordance with Example 4 (amber glass) were treated as follows- (a) 100% cognac immersion (approximately 37% alcohol) for 4 hours at ZOOC.

Resultatz- (i) No color change compared to standard. (ii) No gloss loss compared to standard. (iii) No loss of adhesion compared to standard after removal after half an hour. (iv) No blistering, film degradation or softening. (b) 100% industrial denatured spirit under watch glass for four hours at ZOOC.

Resultatz- (i) No color change compared to standard. (ii) No gloss loss compared to standard. (iii) Slight softening of the coating was noted initially; the recovery was rapid.

This example demonstrates that bottles coated in accordance with the invention should be satisfactory to the liquor market.

EXAMPLE .. 12 Rope resistance and glass strength are directly related (bottle ~ cross strength decreases in fact due to abrasion 459 967 during handling and transport). A scratch on the surface of a bottle causes a weak point and breakage will begin at this point. Rope strength is measured by rubbing two bottles against each other under increasing pressure. The result is the pressure at which a scratch can be noticed on either of the bottles. The minimum standard for bottles is 18 kg, ie at less than 18 kg a bottle is discarded.

A test - the scratch test with static compression - was performed on (i) two control bottles (prior art) and (ii) two bottles coated according to Example S. In the scratch test with static compression, the two bottles are placed one on top of the other and a static weight placed on top of the bottle for one minute. The surface is then examined for coating removal and glass scratching.

With the control bottles, scratching occurred in the range of 40-60 kg. However, with the bottles coated in accordance with the invention, no scratches were visible at the maximum load of the equipment of 110 kg.

EXAMPLE 13 In this example, which is related to Example 6, two batches of six bottles each were exposed for five minutes to an AGR line simulator and then subjected to the AGR ramp pressure test. The bottles in the first batch (B) were conventionally coated with (i) stannic chloride and (ii) the wax product known commercially as "Valspex". The bottles in the second batch (C) were coated with (i) stannous chloride and (ii) in accordance with Example 1. The results are given below: XɧEHA§DLING ¿(B) Stannic chloride (C) Stannic chloride% Improved- plus Valspex plus coating ring according to example 1 (C) over (B) ä 23 459 967 BOTTLE NO kg / cmz ka / cmz 1. 17.3 24.5 41-4 2. 17.4 24.5 90-7 3. 15.2 20.9 29-2 4. 13.9 31.1 166.9, 16.6 25.9 56.2 6, 16.7 29.6 76.9 Total 98.1 162.4 _ Average 16.35 27.1 65.6 nQ¶ ¿- Bottle 4 survived the upper limit of the test equipment.

The results show that the bottles coated in accordance with the invention obtain a dramatic improvement of the rupture strength.

It will be appreciated that since the cladding materials and desiccants are extensively variable within the parameters defined above, the foregoing examples could be significantly expanded. However, the examples given (which are representative of treatments and tests performed in the development of the invention) should be sufficient to clearly illustrate the invention and its advantages.

As a non-limiting summary, the invention thus provides protection and structural reinforcement of glassy and other substrates. This allows the manufacturer to reduce the mass of its hash material as its burst strength and fragment retention characteristics are improved. The coating material can be applied and cured within treatment times of short duration (on the order of five minutes) under room temperature conditions. It is believed that through the invention a significant advance has been achieved in the art.

Claims (11)

459 967 24 Patent claims 1. l. Structural coating comprising a one-component coating material. containing free isocyanate groups applied to a glassy, ceramic or porcelain substrate or substrate, characterized in that the coating material is dried at room temperature on the substrate by a vapor phase drying agent to a layer having a thickness of less than 40 microns, and that the drying agent is : (a) ammonia, an amine or an alkanolamine; or (b) a multicomponent agent comprising (i) water and (ii) an additional component selected from an amine or alkanolamine. 2. '.2. Structural coating according to claim 1, characterized in that the drying agent used is: (b) a multicomponent agent comprising water and an amine. 3. Structural coating according to claim 1 or 2, characterized in that the dried coating material has a layer thickness of 10-20 microns. A method of forming a structural coating on a glassy, ceramic or porcelain substrate or substrate to thereby protect and reinforce the substrate, comprising the steps of applying a one-component coating material containing free isocyanate groups to the substrate and thus exposing the coating. the substrate for drying, characterized in that coating material is applied in such a quantity that after drying a layer with a thickness of less than 46 microns is obtained, that the drying is effected by subjecting the coated substrate to treatment with a desiccant at room temperature, and that the desiccant is in the vapor phase and is: (a) ammonia, an amine or an alkanolamine; or (b) a multicomponent agent comprising (i) water and (ii) an additional component selected from an amine or alkanolamine. 5. A process according to claim 4, characterized in that the coating material is selected from toluene diisocyanate prepolymers and mixtures thereof and xylene diisocyanate prepolymers and mixtures thereof. 6. A method according to claim 4 or 5, characterized in that the drying agent is a multicomponent agent comprising or composed of water and an amine. Process according to any one of claims 4-6, characterized in that the amine is selected from DMEA, TMEDA and PMT. Process according to either of Claims 6 and 7, characterized in that the amine is DMEA and drying is carried out at a concentration of DMEA of 1200-180 ppm at a relative humidity of 45-85% and a temperature of 20-25. ° C. 459 967 '26 9. A method according to any one of claims 4-8, characterized in that the coating material is applied in such a quantity that after drying a layer with a thickness of 10-20 microns is obtained. 10. A method according to any one of claims 4-9, characterized in that the substrate is a glassy container. 11. ll. A method according to claim 10, characterized in that the glassy container is a glass bottle. you