EP2209881B1 - Cleaning cloths for spectacles - Google Patents

Description

The subject of this invention is the use of a hard surface cleaning cloth comprising a substrate and an aqueous composition for cleaning spectacle lenses. The lenses may also be coated with a nanocoating.

The number of spectacle wearers in society continues to increase. On the one hand, changed living and working conditions on the other hand, as well as improved medical and diagnostic methods as well as greater social acceptance of wearing glasses have contributed to this. A large part of the population is constantly wearing visual aids, and many still rely on glasses for special tasks such as reading or screen work. In addition, sunglasses, whether with or without corrective lenses, are considered an important fashion accessory.

While the lenses were originally ground from mineral glass, plastic lenses are increasingly in use today. The advantage is both the lower weight and the lower tendency to breakage; disadvantageous, however, is the higher scratch sensitivity. Both to improve the scratch resistance and to impart further desirable properties, therefore, spectacle lenses made from thermosets are often coated, generally with hydrophobic nanocoatings.

Corrective and sunglass cleaning wipes are becoming increasingly popular with consumers as they allow quick and easy cleaning anywhere, anytime. The cleaning of coated lenses, however, poses some problems for the user since such glasses are difficult or impossible to wet with conventional surfactant / solvent mixtures. So far, only agents with a very high surfactant content could be used to clean such lenses. However, wipes impregnated with such agents leave drops on the surface. If these surfactant-containing drops are not polished out with a second, clean cloth, circular, interfering surfactant residues remain on the glass. The need for a second drape, however, counteracts the ease of use of the disposable wipes. Also, some types of coating are attacked by conventional detergent ingredients, so that the coating wears off over time.

It would therefore be desirable to have a residue-free cleaning agent or at least one low-residue cleaning agent, whose low residues dry out transparently and only to a limited extent, ideally not at all, affect the refractive index of the lenses. At the same time, the wetting agent should be solvent compatible. It should find use in a damp cleaning cloth, which allows a comfortable, residue-free cleaning of a pair of glasses without repolishing with a second, dry cloth. The object of this invention was therefore to provide a cleaning cloth for spectacles, which has a good cleaning performance even with nano-coated plastic lenses and at the same time protects the coating.

EP1974715 discloses an impregnation solution for impregnated cleaning wipes, in particular eyeglass wipes containing water, ethanol and pyrrolidonecarboxylic acid ester (PCA ester), furthermore surfactants, for example anionic surfactants such as sodium lauroyl sarcosinate.

It has been found that an active ingredient combination of alkylpyrrolidone (ideally 1-octyl-2-pyrrolidone), solvents and small amounts of surfactants and water applied to a paper or microfiber cloth solves the contradictions described above.

The application therefore relates to the use of a hard surface cleaning cloth comprising a substrate and an aqueous composition, the latter containing at least one alcoholic solvent, an alkylpyrrolidone and up to 0.1% by weight of at least one anionic surfactant.

With the cleaning cloth according to the invention, a significantly improved wetting of spectacle lenses made of polycarbonates, for example polydiallyldiglycol carbonates, is achieved. It does not matter if the glasses have a coating. Further advantages are that the wetting agent in the aqueous composition does not build up on the substrates used, so that it remains effective even after prolonged storage, and that it forms no or at least a transparent film, so that the optical properties of the glasses not be affected. Also, the glass coating is not damaged by the aqueous composition.

In the context of the present invention are fatty acids or fatty alcohols or their derivatives - unless otherwise stated - representative of branched or unbranched carboxylic acids or alcohols or their derivatives having preferably 6 to 22 carbon atoms. The former are particularly preferred for their vegetable base as based on renewable raw materials for environmental reasons, but without limiting the teaching of the invention to them. In particular, the oxo alcohols or their derivatives which are obtainable, for example, by the ROELEN's oxo synthesis can also be used correspondingly.

Whenever alkaline earth metals are mentioned below as counter ions for monovalent anions, this means that the alkaline earth metal is of course only present in the half-charge amount equal to the amount of the anion as the anion.

Substances which also serve as ingredients of cosmetic products are hereinafter referred to as appropriate according to the International Nomenclature Cosmetic Ingredient (INCI) nomenclature. Chemical compounds carry an INCI name in English, vegetable ingredients are exclusive listed in Linnaeus in Latin. So-called trivial names such as "water", "honey" or "sea salt" are also given in Latin. The INCI names are the " International Cosmetic Ingredient Dictionary and Handbook, Seventh Edition (1997 ), that of The Cosmetic, Toiletry and Fragrance Association (CTFA), 1101, 17th Street NW, Suite 300, Washington, DC 20036, USA ., and contains more than 9,000 INCI names, as well as references to more than 37,000 trade names and technical names, including related distributors from over 31 countries. The International Cosmetic Ingredient Dictionary and Handbook associates the ingredients with one or more chemical classes, such as "Polymeric Ethers," and one or more functions, such as "surfactants-cleansing agents," which it further details , Where appropriate, reference will also be made hereinafter.

The indication CAS means that the following sequence of numbers is a name of the Chemical Abstracts Service.
Unless otherwise stated, amounts given are percentages by weight (% by weight) of the total composition. These percentages refer to active contents.

alkylpyrrolidone

The aqueous composition used in the cleaning cloth according to the invention contains an alkylpyrrolidone. Suitable alkylpyrrolidones here have a C _6-16 -alkyl chain, in particular a C _8-18 -alkyl chain. Particularly preferred is the 1-octyl-2-pyrrolidone. This is available from International Specialty Products, for example, under the trade name Surfadone ^® LP-100. The alkylpyrrolidone is preferably used in amounts of 0.001 to 0.1 wt .-%, more preferably in amounts of 0.005 to 0.05 wt .-%.

Alcoholic solvent

Furthermore, the composition contains at least one alcoholic solvent. This solvent is preferably selected from the group comprising C _1-6 -alcohols, C _2-6 -diols and mixtures thereof, in particular selected from the group comprising ethanol, isopropanol, n-propanol, n-butanol, ethylene glycol, diethylene glycol, propylene glycol and Mixtures thereof, more preferably ethanol, isopropanol, n-propanol and mixtures thereof.

Exemplary solvents are the following compounds named INCI: Alcohol (ethanol), n-butyl alcohol, t-butyl alcohol, butylene glycol, diethylene glycol, dipropylene glycol, ethyl hexanediol, glycol, hexanediol, 1,2,6-hexanetriol, hexyl Alcohol, hexylene glycol, isopentyl diol, isopropanol (INCl isopropyl alcohol), methyl alcohol, methyl propane diol, neopentyl glycol, pentylene glycol, propane diol, propyl alcohol (n-propanol), propylene glycol, tetrahydrofurfuryl alcohol, trimethylhexanol.

Preferably, the aqueous composition contains alcoholic solvents, in particular selected from the group comprising ethanol, n-propanol, isopropanol and mixtures thereof, in amounts of 30 to 70 wt.%, Preferably 40 to 60 wt .-%.

Anionic surfactants

The aqueous composition further contains at least one anionic surfactant. Preferred anionic surfactants in the context of this invention are C ₈ -C ₁₈ -monoalkyl sulfates (in particular fatty alcohol sulfates), C ₈ -C ₁₈ -alkyl polyglycol ether sulfates (fatty alcohol ether sulfates) having 2 to 6 ethylene oxide units (EO) in the ether portion, C ₈ -C ₂₀ -alkanesulfonates, C ₈ C ₁₈ -N sarcosinates and C ₈ -C ₁₈ N-acyl taurides. Furthermore, C ₈ -C ₁₈ -α-olefin can, sulfonated C ₈ -C ₁₈ fatty acids, especially dodecyl benzene sulfonate, C ₈ -C ₂₂ -Carbonsäureamidethersulfate, sulfosuccinic acid mono- and di-C ₈ -C _le alkyl, C ₈ - C ₁₈ -Alkylpolyglykolethercarboxylate and C ₈ -C ₁₈ -Alkylisethionate or mixtures thereof are used. Preference is given to using fatty alcohol sulfates, fatty alcohol ether sulfates, secondary alkyl sulfonates, sarcosinates and / or taurides. The use of linear alkylbenzenesulfonates, however, is not preferred.
The anionic surfactants are preferably used as sodium salts, but may also be present as other alkali or alkaline earth metal salts, for example magnesium salts, and in the form of ammonium or mono-, di-, tri- or tetraalkylammonium salts, in the case of the sulfonates also in the form their corresponding acid, eg dodecylbenzenesulfonic acid.

Fatty alcohol sulphates

Suitable alkyl sulfates (fatty alcohol sulfates, FAS) are the alkali metal salts and, in particular, the sodium salts of the sulfuric monoesters of C _12-18 fatty alcohols, for example coconut oil fatty alcohol, tallow fatty alcohol, lauryl, myristyl, cetyl or stearyl alcohol or C _10-20 oxo alcohols and those half-esters of secondary alcohols of these chain lengths are preferred. Also preferred are alkyl sulfates of said chain length, which contain a synthetic, straight-chain alkyl radical produced on a petrochemical basis, which have an analogous degradation behavior as the adequate compounds based on oleochemical raw materials. Particularly preferred are the C ₁₀ -C ₁₆ alkyl sulfates, in particular the C _12-14 alkyl sulfates. Furthermore, it is also possible to use alkyl sulfates having mono- or polysubstituted alkyl chains or cyclic alkyl radicals.
The fatty alcohol sulfates are usually as alkali metal, alkaline earth metal and / or mono-, di- or Trialkanolammoniumsalz and / or but also in the form of their with the corresponding alkali metal hydroxide, alkaline earth metal hydroxide and / or mono-, di- or trialkanolamine to be neutralized in situ corresponding acid used. Preference is given here as alkali metals potassium and sodium in particular, as alkaline earth metals calcium and magnesium in particular, and as alkanolamines mono-, di- or triethanolamine. Preferably used fatty alcohol sulfates are especially the sodium or the monoethanolamine lauryl sulfate.

fatty alcohol

Alkyl ether sulfates (fatty alcohol ether sulfates, INCI alkyl ether sulfates) are products of sulfation reactions on alkoxylated alcohols. In this context, the person skilled in the art generally understands, under alkoxylated alcohols, the reaction products of alkylene oxide, preferably ethylene oxide, with alcohols, in the context of the present invention preferably with longer-chain alcohols, ie with aliphatic straight-chain or one or more branched, acyclic or cyclic, saturated or mono- or polyunsaturated, preferably straight-chain, acyclic, saturated, alcohols having 6 to 22, preferably 8 to 18, in particular 10 to 16 and particularly preferably 12 to 14 carbon atoms. In general, from n moles of ethylene oxide and one mole of alcohol, depending on the reaction conditions, a complex mixture of addition products of different degrees of ethoxylation (n = 1 to 30, preferably 1 to 20, especially 1 to 10, particularly preferably 2 to 4). Another embodiment of the alkoxylation involves the use of mixtures of the alkylene oxides, preferably of the mixture of ethylene oxide and propylene oxide. Very particularly preferred for the purposes of the present invention are low-ethoxylated fatty alcohols having 1 to 4 ethylene oxide units (EO), in particular 1 to 2 EO, for example 2 EO, such as Na-C _12-14 fatty alcohol + 2EO sulfate.

Particularly preferred anionic surfactants are fatty alcohol sulfates, such as sodium lauryl sulfate, fatty alcohol ether sulfates, such as sodium lauryl ether sulfate with 2 EO, secondary alkyl sulfonates, sarcosinates, taurides and mixtures thereof. The agent contains anionic surfactants in amounts of up to 0.1 wt.%, In particular up to 0.005 wt .-%.

Other surfactants

In addition to anionic surfactants, the aqueous composition may also contain other surface-active substances (surfactants), in particular from the class of nonionic surfactants.

Suitable nonionic surfactants here are exclusively long-chain alkylpolyglycosides having 8 to 14 carbon atoms in the alkyl moiety and 1 to 3 glycoside units and also silicone polyethers. An example of such surfactants is cocoalkyl polyglucoside with on average 1.4 glucose units. In a preferred embodiment, however, the aqueous composition is free of nonionic surfactants.

Other ingredients

In addition to the components mentioned, the aqueous composition may contain other auxiliaries and additives, as are customary in such agents. These include in particular fragrances (perfume oils), Antistatic agents, preservatives, corrosion inhibitors, complexing agents for alkaline earth ions, UV absorbers and electrolyte salts. The amount of such additives is usually not more than 1% by weight in the composition. The lower limit of the use depends on the type of additive. For example, the aqueous composition may contain up to 0.5% by weight, preferably up to 0.25% by weight of perfume. The amount of auxiliaries is preferably below 1% by weight in total.

The pH of the composition is preferably in a range of 6 to 11, more preferably 7 to 10.5.

The composition can be prepared by blending directly from its raw materials, then mixing and finally standing the blister until free of bubbles.

As the substrate for the aqueous composition, a cloth for single use is used. Preferably, a paper or microfibre cloth is used. Plastic nonwovens, on the other hand, are not suitable as substrates.

Papers are understood to be a flat material consisting essentially of fibers of predominantly vegetable origin, which is formed by dewatering a pulp slurry on a sieve. This results in a fiber felt, which is then compressed and dried. The basis weight is generally up to 225 g / m ² . The fibers that make up the main component of the paper are mainly derived from wood. Depending on the specific manufacturing process, properties and intended use, a distinction is made between different types of paper, such as banknote paper, handmade paper, tissue paper, writing paper, photographic paper, tissue paper or even crepe paper. The latter is wet or dry creped stretched and pliable made paper types. For this purpose, the so-called creping cylinders are used instead of the drying cylinder usually used in the dryer section, which are steam-heated cylinder on which the paper web is compressed by a creping doctor and thereby significantly shortened. Crepe papers are used, for example, as hygiene papers, for example as household towels.

Microfibers are textile fibers of, for example, polyesters, polyamides or polytetrafluoroethylene, which are produced during spinning from spinnerets with many holes when the spinneret tip is blown hot air at high speed, which breaks the filaments into short fibers. The resulting microfibers with an average fineness of 0.1 to 0.3 dtex are processed to a so-called microfiber tangle of extremely small pore size (1 dtex = 1 g / 10000 m). The small pore size ensures that raindrops, for example, can not penetrate into the fabric while water vapor can escape, creating a breathable and waterproof cloth at the same time.

Among the paper towels, those made of crepe paper, in particular cellulose crepe paper, are particularly suitable, as offered, for example, by the companies NeuKaliss, Schoeller & Hoesch, Lenk and Kimberly-Clark become. Preferred crepe papers have a basis weight of 20 to 50 g / m ² . In addition, microfiber cloths with a basis weight of 30 to 80 g / m ² can be used.

The substrate is impregnated with the aqueous composition and preferably individually packaged. In this case, the aqueous composition is preferably applied to the substrate in an amount of 20 to 55 g / m ² .

A process for the production of a cleaning cloth is therefore feasible, in which a substrate, preferably selected from the group consisting of paper towels, in particular crepe paper, and microfibre cloths, is impregnated with an aqueous composition containing at least one alcoholic solvent, preferably selected from the group comprising ethanol, n-propanol, isopropanol and mixtures thereof, an alkylpyrrolidone, preferably 1-octylpyrrolidone, up to 0.1% by weight of at least one anionic surfactant and optionally perfume. In this case, the application amount of the composition to the substrate is preferably 20 to 55 g / m ² .

Examples

A total of seven aqueous compositions were formulated and crepe paper towels soaked in a 1: 1 mass ratio. The compositions E1 to E3 were used according to the invention. The comparative formulation V1 had too high a surfactant content, the further comparative formulations V2 to V4 were free of alkylpyrrolidone derivatives.
The wipes were then used to clean hydrophobized ophthalmic lenses that had been treated with pigmented greasy soil, and visually evaluated to assess cleansing performance and residue formation. It was found that the compositions E1 to E3 had the best ratio between cleaning performance and residue formation. Table 1: Impregnating liquids on crepe paper (mass ratio liquid / cloth 1: 1) composition E1 E2 E3 V1 V2 V3 V4 1-octyl-2-pyrrolidone 0.01 0.01 0.15 0.01 - - - ethanol 60 60 60 60 60 60 60 Perfume 0.25 0.25 0.25 0.25 0.25 0.25 0.25 Anionic surfactant 0.001 - 0.01 0.4 0.4 0.01 - water At 100 At 100 At 100 At 100 At 100 At 100 At 100 Cleaning performance on pigmented greasy soil on hydrophobic plastic glasses (visual evaluation) ++ + ++ ++ ++ + O Residue on hydrophobic plastic glasses (visual evaluation) ++ ++ + - - - O The quantities are in wt .-% active ingredient.

Claims (11)

1. Use of a cleaning cloth for hard surfaces, which cloth contains a substrate and an aqueous composition, for cleaning ophthalmic lenses, in particular made of plastic, wherein the aqueous composition comprises

   - at least one alcoholic solvent,

   - an alkyl pyrrolidone and

   - up to 0.1 wt % of at least one anionic surfactant.
2. Use according to claim 1, characterised in that the substrate is preferably selected from the group containing paper towels, in particular crepe paper with a grammage of 20-50 g/m², and microfibre towels with a grammage of 30 to 80 g/m².
3. Use according to one of claims 1 or 2, characterised in that the alkyl pyrrolidone is 1-octyl-2-pyrrolidone.
4. Use according to one of the preceding claims, characterised in that the alcoholic solvent is preferably selected from the group containing ethanol, n-propanol, isopropanol as well as mixtures of the same and is preferably comprised in amounts of 30 to 70 wt %, preferably 40 to 60 wt %.
5. Use according to one of the preceding claims, characterised in that the aqueous composition comprises an alkyl pyrrolidone, preferably 1-octyl-2-pyrrolidone, in amounts of 0.001 to 0.1 wt %, preferably 0.005 to 0.05 wt %.
6. Use according to one of the preceding claims, characterised in that the aqueous composition comprises up to 0.5 wt %, preferably up to 0.25 wt % perfume.
7. Use according to one of the preceding claims, characterised in that the aqueous composition comprises one or more anionic surfactants, preferably selected from the group containing fatty alcohol sulfates, fatty alcohol ether sulfates, secondary alkyl sulfonates, sarcosinates, taurides as well mixtures of the same, in amounts of up to 0.1 wt %, preferably up to 0.005 wt %.
8. Use according to one of the preceding claims, characterised in that the aqueous composition is free of surfactant.
9. Use according to one of the preceding claims, characterised in that the aqueous composition is deposited in an amount of 20-55 g/m² onto the substrate according to claim 2.
10. Use according to one of the preceding claims, characterised in that the cleaning cloth is individually packaged.
11. Use according to one of the preceding claims, characterised in that the ophthalmic lenses may have a nanocoating.