FR2907113A1 - Dyeing of organic glass i.e. ophthalmic or solar glass, comprises glazing the organic glass in a glaze bath, preparing a coloring bath by adding an aqueous solution, soaking the glazed organic glass in the coloring solution - Google Patents

Abstract

Dyeing of organic glass, preferably ophthalmic or solar glass, except polyester and/or polycarbonate glass, comprises glazing the organic glass in a glaze bath, preparing a coloring bath by adding an aqueous solution prepared from demineralized water under agitation and a surfactant or a mixture of surfactants at 0.5-2 wt.% of the aqueous solution, soaking the glazed organic glass in the coloring solution i.e. maintained at greater than 50[deg] C, preferably greater than 90[deg] C, where the glazing can be done before or after the dyeing stage.

Description

BACKGROUND OF THE INVENTION

  The invention relates to the field of organic glass coloring, especially ophthalmic or solar glass. State of the art: According to the state of the art, the coloration of the organic glasses is carried out before the varnishing step in a bath at a temperature typically between 90 ° C. and 95 ° C. This may lead to the following problems: risk of partial discoloration during the varnishing, because the dyes are sensitive to the alkaline solutions which are used during the varnishing step, - a contamination of the varnish bath by the dyes (because of the affinity of the solvents used to the varnishes with the dye molecules), which has the effect of reducing its life, - a risk of peeling off the varnish. In particular, if such staining is performed on a polycarbonate glass, it is frequently observed that the varnish peels off the glass; this could be related to the accumulation of the dye at the interface between the glass and the varnish, especially in the case where the glass does not establish a strong bond with the dye. On the other hand, in some cases, the direct dyeing of the organic glass leads to a certain opacity of said glass, due to the attack of the glass surface by solvents and / or dye surfactants. The present invention proposes to remedy the disadvantages enumerated above, by proposing a modified organic glass processing method which makes it possible to use not only disperse dyes, as is known from the state of the art, but also acid dyes. OBJECT OF THE INVENTION The present invention relates to a method for treating organic glass, in particular ophthalmic or solar glass. DESCRIPTION OF THE INVENTION The method for treating organic glass, particularly ophthalmic or solar glass, according to the invention, comprises the following steps: a) In a bath of varnish, the varnishing of an organic glass to be colored is carried out , in particular an ophthalmic or solar glass, b) an organic glass coloring bath is prepared by adding to a stirred aqueous solution, preferably prepared from deionized water, a surfactant or a mixture of surfactants. at a total content by weight of between 0.5% and 2% by weight of said aqueous solution, c) then adding to said aqueous solution a dye or a mixture of dyes at a rate of A total content by weight of between 0.5% and 2% relative to the weight of the said aqueous solution, d) and then the said organic glass to be colored resulting from step a) is quenched into the coloring solution obtained at the end of the reaction. result of step c), said solution being maintained at a temperature above 500C, and preferably at a temperature between 70C and 90C, knowing that step a) can be carried out before or after step d). In an advantageous embodiment, the varnishing step a) is carried out after the d) staining step. As a hypothesis, and without being bound by this theory, the inventors believe that the function of the surfactant or the surfactant mixture is to allow the penetration of the dye into the substrate, namely the organic glass.

  In a particularly advantageous embodiment of the invention, the surfactants used in the process according to the invention are chosen from: hexadecyltrimethylammonium halides (I) (abbreviated: TMDHAX, and also called cetyltrimethylammonium halide) of general formula (CH3) 3N (CH2) 15CH3X (I) 2907113 4 where X- denotes a halide element, namely fluoride (it is then TMDHAF), chloride (it is then TMDHAC), bromide (it is then TMDHAB), iodide (it is then TMDHAI), and preferably chloride, especially because it is the cheapest of the halides; compounds of the general formula (II): ## STR2 ## wherein: R 1 is hydrogen or methyl, R 2 is hydrogen or the group -CH 2 PO (ONa) ) 2, and n is an integer preferably between 4 and 12, and most preferably 8, the compounds of general formula (III): ## STR2 ## where ## STR2 ## 2 (III) wherein: R1 is hydrogen or methyl, R2 is hydrogen or the group -CH2PO (ONa) 2, and n is an integer preferably between 4 and 12, and most preferably equal to In the compounds of the general formulas (II) or (III) set forth above, the inventors believe that an increase in the alkyl chains of the groups R1 and R2 causes an increase in the viscosity and a decrease in the stability. color bath. More particularly, if R 1 is an alkyl chain having more than one carbon, solubility problems in the water of the surfactant have been observed. A particularly preferred surfactant is DPF 204 (IV) marketed by CHRYSO: CH2-PO (ONa) 2 (IV). In the organic glass coloring process according to the invention, it is used. or acid dyes, or disperse dyes.

Acid dyes are anionic dyes. Acid dyes such as disperse dyes are particularly suitable for coloring polyamides.

It is known that acid dyes are typically aminoanthraquinone sulfonic or hydroxyamino anthraquinone sulfonic acids. The sulfo groups are attached to either an arylamino residue or directly to the anthraquinone ring. They are generally obtained by replacement of the halogen, OH, SO3H groups of anthraquinone with amine residues, or else prepared by nitration of hydroxyanthraquinone sulfonic acid, followed by reduction of the nitro functions. The preferred dyes according to the invention are given below with reference to the names of the CI (Color Index) classification: - Acid Blue (HCl) (C2H40) 8 -CH2H4N2H2PO (ONa) 2 113, CAS RN [3351-05-1], 5 - Disperse Red 17, CAS RN [3179-89-3], - Disperse Yellow 3, CAS RN [2832-40-8], -Acid Yellow 42, CAS RN [6375-55-9], - Acid Red 42, CAS RN [6245-60-9].

The organic glass coloring step of the process according to the invention can be carried out more particularly with certain combinations of surfactants and dyes as enumerated below.

In a particularly advantageous embodiment, during the step of staining the organic glass, TMDHAX of formula (I) is combined with one or more acid dyes.

Indeed, there is an ion exchange between the acid dye and the surfactant TMDHAX, namely between the quaternary ammonium of said surfactant and the sulfonate functional groups of the acid dye.

More particularly, organic glass staining is successfully carried out when the TMDHAX of formula (I) is combined with one or more of the following colorants: - Acid Blue 113, - Acid Yellow 42, Acid Red 42.

With disperse dyes, and in particular Disperse Red 17 and Disperse Yellow 3, satisfactory results are not obtained when TMDHAX is used as a surfactant. The surfactants of the general formulas (II) and (III) mentioned above are combined with the disperse dyes.

More particularly, the surfactants of general formulas (II) and (III) mentioned above combine perfectly and successfully with the dyestuffs indicated below: Disperse Red 17, Disperse Yellow 3, while with the acid dyes, and in particular Acid Blue 113, Acid Yellow 42, and Acid Red 42, satisfactory results are not obtained.

The inventors believe that a chelation phenomenon occurs between the surfactants of the general formulas (II) and (III) and the disperse dyes, in particular between the phosphonate groups of the surfactant and the ketone and hydroxyl functional groups of the disperse dye.

The invention makes it possible to use dye mixtures to obtain the usual shades in the field of solar optics.

Thus, to obtain, for example, a gray tint, a mixture of dyestuffs with the following proportions by weight of dyes is typically used with the THMDAX surfactant: - 70% Acid Blue 113, - 20% by weight Acid Red 42, 5 - 10% of Acid Yellow 42. Similarly, to obtain, for example, a brown hue, a mixture of dyes with the contents in weight is typically used with one of the surfactants of general formula (I). following: - 50% Acid Blue 113 - 30% Acid Red 42 - 20% Acid Yellow 42.

The temperature of the aqueous solution of the dyeing step of the process according to the invention is typically of the order of 80 ° C. When the temperature is significantly lower, the coloration does not proceed sufficiently rapidly.

However, the temperature of the staining bath is chosen so as to control the kinetics of coloration, that is to say lower than that of the state of the art which is generally around 90.degree.

Furthermore, it is important to keep the temperature constant at +/- 5 C, preferably at +/- 3 C, and very preferably at +/- 1 C. Indeed, a small variation in the temperature causes a variation. significant kinetics, and thus can lead to a disappointing result as to the desired color.

The contents by weight of the dye and the surfactant are typically between 0.8% and 1.2%, and preferably of the order of 1%, relative to the weight of the aqueous solution of the coloring bath.

The addition of the dye or dye mixture is advantageously carried out for 2 to 10 minutes, and typically 5 minutes after adding the surfactant or surfactant mixture to the dye bath, so that the surfactant or surfactant mixture has was dispersed homogeneously in the aqueous solution. In addition, it has been found that with the dyeing step of the process according to the invention, the dyes do not release, that is to say they remain fixed on the organic glass, which makes it possible to effective cleaning of said organic glass, particularly ophthalmic or solar, without the dye fades.

The method described above has been successfully tested on polyamide or thermosetting glass-coated glasses, giving a completely homogeneous coloring result. The dye or dye mixture thus passes through the varnish and colors the substrate, namely the organic glass. On the other hand, on polycarbonate glasses coated with varnish, the expected coloring was not obtained. Only the varnish was colored. The dyeing process according to the invention can not therefore be applied to polycarbonate glasses.

According to the state of the art, as regards the varnishes used for coating organic glasses, two categories can be distinguished: the tintable varnishes which are not too reticulated, their network being sparse, the non-dyeable varnishes which have a higher hardness and better adhesion for anti-reflective treatment, because of higher crosslinking, but for which the dyes can not pass through the polymerization network and settle on the glass. It is considered that the less the network is substituted, the more the varnish is easily tintable. It is possible to make stainable varnishes non-stainable by stopping their polymerization before their network is fully crosslinked. By way of example, polysiloxane lacquers are tintable if they are made from mono-, di- or trifunctional monomers. As regards the tetra-functional monomers, it is necessary to add colloidal silica so that they are tintable.

A test for determining whether a varnish is tintable or non-tintable consists of immersing, for about 15 minutes while stirring, the substrate coated with the test varnish in a coloring bath, thermostatted at a temperature between 85 ° C. and 100 C, and preferably equal to 88 C, comprising either BPI Black is B.P.I. Sun Gray at a concentration of 10% by weight relative to the weight of the aqueous solution. The varnish is considered non-tintable if the light transmission has decreased by not more than 5%, before and after immersion of the varnished substrate in the color bath described above. In all other cases, the varnish is then considered as tintable.

There may be mentioned commercial names of tintable varnishes such as: - TS56T from Tokuyama Soda, - Silvue 339 from SDC coatings, - HI-GARD 1020 from PPG, 15 - Chemopcoat 152T from Chemoptics. Non-dyeable varnish trade names are: - Tokuyama Soda TS 56 H, - SDC Coatings Crystal Coat 1154 D, - PPG Hi-Gard 1080, - Chemoptics 152 H Chemopcoat, 25 The inventors have discovered It is quite surprising that the process described according to the invention was also suitable for varnishes known to be unstainable, and that no detachment of the varnish was observed. Indeed, comparisons have been made with reference dyes of the current market for glasses coated with non-dyeable varnish. It has thus been found that after 45 minutes of coloring, an absorption capacity of 40% is obtained with the process according to the invention, whereas with the prior art coloring baths 2907113 12 an absorption capacity of only 5% was obtained after 12 hours. Thus, the treatment method according to the invention can be carried out, for example, on the following substrates: polyamide glasses, crosslinked polythiourethane glasses resulting from the polymerization of a mixture of polythiol and polyisocyanate, more particularly on a product of MR8 (a product marketed by Mitsui Chemicals), thermosetting glasses coated with a tintable or non-tintable varnish such as di-allyl glycol polycarbonate (a material known as CR39). On the other hand, the treatment method according to the invention can not be carried out on polycarbonate, polyester or polycarbonate and polyester glasses.

EXAMPLES Example 1 To one liter of demineralized water heated to a temperature of 90 ° C. was added 10 grams of a dye, the reference CI of which was Acid Blue 113, and 10 grams of a solution containing sodium chloride. 25% cetyltrimethylammonium in water. The temperature of the color bath was stabilized by a water bath and a lid was used to limit evaporation. Then, an ophthalmic polycarbonate lens of di-allyl glycol (a material known under the trade name CR39) whose initial light absorption was 10% was immersed in the color bath. After five minutes of immersion, the glass was rinsed in a city water bath and an 80% light absorption was measured. The color was uniform on the surface of the glass. Another ophthalmic lens of the same characteristics as the previous one has been soaked in a bath containing the equivalent preparation commercially available under the name BPI Sun Vogue Marine (a reference in the ophthalmic market). After five minutes of immersion under the same conditions the glass had a homogeneous light absorption of only 40%. Example 2: Example 1 was repeated, but this time the CR39 glasses were replaced with MR8 glasses, a cross-linked polythiourethane of refractive index 1.604. After five minutes in the solution containing the mixture of the present invention, the light absorption was 65%. It was 85% after ten minutes. Using the reference commercial product, the absorption obtained was only 30% after five minutes and 40% after ten minutes. It was necessary to leave the glass for 60 minutes to obtain 85% absorption. Example 3: Example 2 was repeated after allowing the baths to stand for 30 days. The baths were shaken vigorously for five minutes, then the colorless MR8 glasses were allowed to soak in these baths. The bath containing the mixture described according to the invention made it possible to obtain the same results as those of Example 2, thus no loss of activity of the coloring power was observed. In contrast, the bath containing the commercial reference product only allowed 20% absorption after five minutes and 30% after ten, which reflects a significant loss of activity and demonstrates the stability of the staining system described in the present invention.

EXAMPLE 4 Example 1 was repeated replacing the chloride with cetyltrimethylammonium bromide The result obtained is identical to that of Example 1, demonstrating that the activation of the acidic dye is bound to 10. the presence of the cationic surfactant in the dye bath.

Claims (10)

claims   1) A process for coloring organic glass, in particular ophthalmic or solar glass, with the exception of glasses made of polyester, polycarbonate or a mixture of polycarbonate and polyester, said process comprising the following steps: a) in a bath of varnish, performs the varnishing of an organic glass to be colored, in particular an ophthalmic or solar glass; b) An organic glass coloring bath is prepared by adding to a stirred aqueous solution, preferably prepared from demineralised water, a surfactant or a mixture of surfactants at a total weight content of between 0.degree. , 5% and 2% relative to the weight of said aqueous solution; c) then adding to said aqueous solution a dye or a mixture of dyes at a total content by weight of between 0.5% and 2% by weight of said aqueous solution; d) then quenching said organic glass to be colored resulting from step a) into the coloring solution obtained at the end of step c), said solution being maintained at a temperature above 50 ° C. and preferably at a temperature between 70 C and 90 C, knowing that step a) can be performed before or after step d). 30   2) A method according to claim 1 characterized in that the surfactant is: 2907113 16 if the dye or dye mixture used in the dyeing step (step d) is a dye or a mixture of disperse dyes, a phosphonated derivative of the general formula: ## STR2 ## wherein Y is a nitrogen atom or the group -PO, R 1 is a hydrogen or a methyl group, R 2 is a hydrogen or the group - (CH2PO (ONa) 2), and n is an integer preferably of between 4 and 12, and very preferably of 8, - if the dye or mixture of dyes used in step The coloring agent is a dye or a mixture of acid dyes, a hexadecyltrimethylammonium halide (TMHDAX) of the general formula: X- + äCH3 N 1 CH3 3   3) Process according to any one of claims 1 or 2 characterized in that 1 hexadecyltrimethylammonium halide (TMHDAX) is hexadecyltrimethylammonium chloride (TMHDAC) or hexadecyltrimethylammonium bromide (TMHDAB). 5 (V) 2907113 17   4) Process according to claim 1 or 2, characterized in that the surfactant is the compound of formula: ## STR2 ##   5) Method according to any one of claims 1 to 4 characterized in that the dye is selected from the group consisting of Acid Blue 113, Disperse Red 17, Disperse Yellow 3, Acid Yellow 42 and Acid 10 Red 42.   6) Process according to any one of claims 1 to 5 characterized in that the organic glass is a polyamide glass or a thermosetting glass type.   7) Process according to any one of claims 1 to 6 characterized in that the organic glass is covered with a tintable or non-tintable varnish, the non-tintable character being established by a reduction in the transmission of light from maximum 5% between before and after immersion, for about 15 minutes in a staining bath containing either BPI Sun Gray is 25 B.P.I. Black at a mass concentration of 10% relative to the weight of the aqueous solution, with stirring and thermostatted at a temperature of between 85 ° C. and 100 ° C., and preferably equal to 88 ° C., of organic glass covered with a varnish, tintable character being established in all other cases. 2907113 18   8) Process according to any one of claims 1 to 7 characterized in that the surfactant is TMHDAC or TMHDAB and the dye or mixture of 5 dyes is Acid Blue 113 and / or Acid Yellow 42 and / or Acid Red 42.   9) Process according to any one of claims 1 to 8 characterized in that the surfactant is a phosphonated derivative of general formula (V) and the dye or mixture of dyes is Disperse Red 17 and / or Disperse Yellow 3 .   10) Method according to any one of claims 1 to 9 characterized in that the surfactant and the dye preferably have a weight percentage relative to the aqueous solution of between 0.8% and 1.2%, and very preferably equal to 1%. 20 25 30