EP0352783A2 - Cleaning and/or conditioning agent for glass-ceramic surfaces containing organic polysiloxanes - Google Patents

Abstract

The invention relates to a cleaning and / or conditioning agent for glass ceramic surfaces, which is characterized in that it contains epoxy-functional organopolysiloxanes. The cleaning and / or conditioning agent may also contain other components such as non-reactive organopolysiloxanes, surfactants, organic solvents, abrasives, acids, additional additives and water, the composition being in the form of an oil-in-water or water-in-oil emulsion .

Description

The invention relates to a cleaning and / or conditioning agent for glass ceramic surfaces, which contains organopolysiloxanes.

As is well known, heat-resistant cooking appliances for domestic and industrial use are increasingly being made from glass-ceramic materials. In the case of glass ceramic cooktops in particular, stubborn and difficult-to-remove contaminants occur with increasing service life due to the burning or even carbonization of splashed or overflowed cookware. Without appropriate conditioning, excessive chafing can cause severe damage to the surface and, when using cleaning tools such as glass scrapers, even clod-like breakouts on the glass ceramic surface, which can destroy them. Especially with foods with a high sugar content, cleaning without massive surface damage is practically impossible after burning.

The use of organopolysiloxanes in cleaning compositions, such as solutions for washing window panes, car polishes, metal and textile cleaners, is well known. The publications GB-PS 11 72 479, GB-PS 11 71 479, US-PS 3,681,122 and US-PS 4,124,523 essentially describe cleaning agents which consist of an organopolysiloxane, an alkali salt of the 3rd to 5th main group, an abrasive and Water and possibly a thickener and a nonionic surfactant. Although these formulations are generally suitable for cleaning glass ceramic surfaces, the conditioning effect for protecting the surface is completely inadequate. In particular, the protective effect against burnt-on food residues with a high sugar content is insufficient. DE-OS 33 21 289 results in a water-in-oil emulsion consisting of an amino-functional organopolysiloxane, a cyclic dimethylpolysiloxane, a polysiloxane-polyoxyalkylene block copolymer, a scouring powder, a surfactant and water. Although the cleaning effect of this formulation is also present, the protective effect of the amino-functional organopolysiloxane contained as protective film former is again unsatisfactory, in particular with respect to burnt-on food residues containing high levels of sugar. DE-PS 29 52 756 describes compositions which contain a metal oxide and / or amino group-containing polysiloxane, a cleaning or cleaning agent and additional surfactants. The care products in question have a cleaning and conditioning effect, but show a low storage stability as a result of a continuous increase in viscosity, poor polishability and inadequate protection against burning, high-sugar foods. DE-OS 33 27 926 sets out an emulsion formulation which is composed of an amino-functional polydimethylsiloxane, emulsifiers, acid constituents, a solvent, an abrasive, protective film improvers and water. The care products in question perform a cleaning and conditioning effect, but have the same disadvantages as described for DE-PS 29 52 756.

There is therefore a desire for a cleaning and conditioning composition that removes contaminants from glass ceramic surfaces and that also acts as a conditioning agent for the cleaned glass ceramic surfaces to prevent or delay the formation of stubborn and difficult to remove contaminants. The object of the invention is therefore an improved cleaning and / or conditioning agent for glass ceramics which does not have the deficiencies of the prior art listed above.

The invention relates to a cleaning and / or conditioning agent for glass ceramic surfaces which contains organopolysiloxanes, which is characterized in that the organopolysiloxane has epoxy groups.

Destruction of the glass ceramic surface is avoided in the long term by the agent according to the invention. The separating effect of the protective film prevents the burnt-on food from sticking firmly and enables the surface to be cleaned easily and gently at all times. The agent according to the invention is easy to apply and polish and is not prone to smearing or streaking.

zusammen, wobei
R jeweils unabhängig voneinander eine Kohlenwasserstoffgruppe und
Q eine epoxyfunktionelle Gruppe bedeuten,
a für 1, 2 oder 3,
b für 0, 1 oder 2,
c für 1 oder 2,
d für 0, 1 oder 2,
e für 1 oder 2 und
f für 1 oder 2 stehen und
die Summen aus b und c sowie aus d, e und f jeweils nicht größer als 3 sind.The organopolysiloxanes used according to the invention which have epoxy groups are preferably composed of units of the general formulas

together, being
R each independently of one another a hydrocarbon group and
Q represents an epoxy functional group,
a for 1, 2 or 3,
b for 0, 1 or 2,
c for 1 or 2,
d for 0, 1 or 2,
e for 1 or 2 and
f stand for 1 or 2 and
the sums of b and c and of d, e and f are each not greater than 3.

Examples of radicals R are
Alkyl groups with 1 to 22 carbon atoms,
Alkoxyalkyl groups with 1 to 22 carbon atoms,
Aryl groups with 6 to 22 carbon atoms and
Alkaryl groups with 7 to 22 carbon atoms.

Preferred radicals R are methyl, ethyl, methoxyethyl, phenyl and 2-phenylethyl groups.

Particularly preferred radicals R are methyl groups.

entspricht, wobei A Alkyl-, Alkoxyalkyl-, Aryl- oder Alkarylrest bedeutet und die Summe aus x, y und z kleiner 500 ist.Epoxy-functional organopolysiloxanes of the formula have proven particularly advantageous
(CH₃) ₃SiO [(CH₃) ₂SiO] _x [R¹R²SiO] _y [QCH₃SiO] _z Si (CH₃) ₃
proven, being
R¹ and R² are alkyl, aryl or alkaryl and Q of the formula

corresponds, where A is alkyl, alkoxyalkyl, aryl or alkaryl and the sum of x, y and z is less than 500.

Examples of the radicals R¹ and R² are methyl, ethyl and phenyl groups.

Preferred radicals R¹ and R² are methyl groups.

Examples of epoxy functional groups Q are

Preferred epoxy functional groups Q are

The ratio of the indices x, y and z is preferably in a range which results in an epoxy number (equiv./100 g) of 0.4-0.015.

Epoxy-functional organopolysiloxanes with an epoxy number (equiv./100 g) of 0.3-0.08 are particularly preferably used.

The viscosity of the epoxy-functional organopolysiloxanes used is preferably 5-50,000 mm² / s at 25 ° C.

The particularly preferred viscosity range is 10-1000 mm² / s.

The epoxy-functional polysiloxanes can be produced by known processes, such as described in DE-AS 10 61 321. In these publications epoxy-functional polysiloxanes, for example via a transition metal-catalyzed addition of an unsaturated epoxide, such as allyl glycidyl ether, to corresponding Si-H-containing polysiloxanes.

• (A) 5-30 Gew.-%, vorzugsweise 10-20 Gew.-%, erfindungsge­mäß eingesetztes, epoxyfunktionelles Organopolysiloxan
• (B) 0-30 Gew.-%, vorzugsweise 1-5 Gew.-% bei Öl-in-­Wasser-Emulsionen und vorzugsweise 10-­20 Gew.-% bei Wasser-in-Öl-Emulsionen, nichtreaktives Organopolysiloxan
• (C) 1-20 Gew.-%, vorzugsweise 5-15 Gew.-%, oberflächen­aktives Mittel
• (D) 0-50 Gew.-%, vorzugsweise 5-30 Gew.-%, organisches Lösungsmittel
• (E) 5-25 Gew.-%, vorzugsweise 10-15 Gew.-%, Scheuermittel
• (F) 0-10 Gew.-%, vorzugsweise 0-4 Gew.-%, einer sauren Komponente
• (G) 0-10 Gew.-%, zusätzliche Additive, ausgewählt aus der Gruppe der Verdickungsmittel, Konser­vierungsmittel, Farbstoffe und Duftstoffe
• (H) 1-89 Gew.-%, Wasser.

In addition to the epoxy-functional organopolysiloxane, the cleaning and / or conditioning agent according to the invention can also contain other components. If additives are used, the following composition, which can be in the form of both an oil-in-water emulsion and a water-in-oil emulsion, has proven to be particularly effective:

• (A) 5-30% by weight, preferably 10-20% by weight, of epoxy-functional organopolysiloxane used according to the invention
• (B) 0-30% by weight, preferably 1-5% by weight for oil-in-water emulsions and preferably 10-20% by weight for water-in-oil emulsions, non-reactive organopolysiloxane
• (C) 1-20% by weight, preferably 5-15% by weight, of surfactant
• (D) 0-50% by weight, preferably 5-30% by weight, organic solvent
• (E) 5-25%, preferably 10-15%, abrasive
• (F) 0-10% by weight, preferably 0-4% by weight, of an acidic component
• (G) 0-10% by weight, additional additives selected from the group of thickeners, preservatives, dyes and fragrances
• (H) 1-89 wt% water.

The non-reactive organopolysiloxanes (B) are preferably trimethylsilyl group-containing dimethylpolysiloxanes, cyclic dimethylpolysiloxanes, octamethylcyclotetrasiloxanes, decamethylcyclopentasiloxanes or mixtures thereof.

As surface-active substances (surfactants) (C) anionic surfactants such as e.g. Alkyl sulfonates, alkyl benzene sulfonates, sulfosuccinates and nonionic surfactants such as e.g. Alkyl polyglycol ethers, fatty acid polyglycol esters, alkylaryl polyglycol ethers, polyethoxylated fatty acid glycerides, polyglycerol fatty acid esters, polyethoxylated sorbitan esters, fatty acid alkylolamides, polydiorganosiloxane-polyoxyalkylene copolymers and the like. Among other things, these surfactants stabilize the emulsion, support surface cleaning and improve the formation of protective films.

The organic solvent (D) is a hydrocarbon-based solvent, e.g. Gasolines or alcohols, e.g. Isopropanol and ethanol.

The abrasive component (E) serves to enhance the cleaning effect and can be any finely divided powder which provides the desired abrasive effect. Examples of suitable abrasive substances are aluminum oxide, quartz, chalk, diatomaceous earth, colloidal silicon dioxide, sodium metasilicate or talc.

Organic and inorganic acids are used as acidic component (F). For example, acetic acid, citric acid, amidosulfonic acid, acid sulfates, phosphates and phosphoric acid esters are suitable.

The compositions according to the invention can also contain further additives (G) selected from the group of thickeners, preservatives, dyes and fragrances.

The emulsion formulations can be produced by any suitable mixing technique and are characterized by a particularly high storage stability and effect. To produce an oil-in-water emulsion, an oil phase is first formed from components (A) and (C) and optionally (B) and (D), which is then mixed with the aqueous phase (H) with constant stirring. Components (E) and optionally (F) and (G) are then dispersed in successively. In the case of a water-in-oil emulsion, components (A) and (C) and optionally (B) and (D) likewise first form an oil phase, into which the aqueous phase containing the remaining constituents is then dispersed with constant stirring .

During the cleaning and / or conditioning process, the cleaning and / or conditioning agent according to the invention is distributed and rubbed onto the dry glass ceramic surface to be treated using a cloth.

If 100% epoxy-functional organopolysiloxane is used, the epoxy-functional organopolysiloxane is applied to the clean, possibly pre-cleaned glass ceramic surface. For the pre-cleaning of the glass ceramic surface known liquid household detergents that are suitable for cleaning glass ceramic surfaces can be used. Both synthetic and natural tissues are suitable as a textile carrier material for taking up the epoxy-functional organopolysiloxane. The active ingredient can be applied to the fabric by dipping, padding, spraying or brushing, either using the 100% active ingredient or else in a form diluted with a suitable solvent such as hydrocarbons or chlorinated hydrocarbons and then dried. The application amount is 1-100%, based on the weight of the carrier material, but preferably 5-50%. In order to avoid loss of active substance during transport and storage, the cloth treated in this way is preferably sealed in a plastic film.

After the cleaning and / or conditioning process, the glass ceramic surface is polished. The polishing to a streak-free and wet-wipe-resistant protective film is achieved quickly and easily with the agent according to the invention without unpleasant lubrication. After the treatment, the glass ceramic surface has a well-groomed and shiny surface and is permanently protected against the burning of food residues, especially against foods that contain a lot of sugar.

The protective film has a high resistance to thermal stress and to the action of water containing surfactants.

Example 1:

Production of

629 g (5.5 mol) of allyl glycidyl ether were placed together with 530 g of isopropanol, 6 g of powdered Na₂CO₃ and 10 ml of a solution of 1% by weight of hexachloroplatinic acid in isopropanol and flushed with nitrogen for 15 min. The mixture is then heated to 90 ° C. with constant stirring (reflux) and slowly 1500 g of a trimethylsilyl end-blocked liquid dimethylmethylhydrogensiloxane copolymer with a viscosity of 12 mm² / s (25 ° C.) and an Si-H content of 62. 2 cm³ H₂ / g added dropwise. Nitrogen purging was continued. After the metering had ended (about 1 h), the mixture was refluxed for a further 2 hours and the residual Si-H content was checked at regular intervals, which decreased to a maximum of 0.05 cm³ H₂ / g. It was then cooled to 80 ° C., treated with activated carbon and filtered. After removal of the solvent at 120 ° C. and 2 mbar, 1980 g of a colorless organopolysiloxane were obtained with the following properties: Viscosity (25 ° C): 50 mm² / s Epoxy number: 0.22 [equiv./100 g]

Example 2:

Production of

325 g (2.85 mol) of allyl glycidyl ether were placed together with 275 g of isopropanol, 4.5 g of powdered Na₂CO₃ and 6 ml of a solution of 1% by weight of hexachloroplatinic acid in isopropanol and flushed with nitrogen for 15 min. The mixture was then heated to 90 ° C. with constant stirring (reflux) and slowly 1500 g of a trimethylsilyl-end-blocked liquid dimethylmethylhydrogensiloxane copolymer with a viscosity of 54 mm² / s (25 ° C.) and an Si-H content of 38. 8 cm³ H₂ / g added dropwise. Nitrogen purging was continued. After the metering had ended (about 1 h), the mixture was refluxed for a further 2 hours and the residual Si-H content was checked at regular intervals, which decreased to a maximum of 0.05 cm³ H₂ / g. It was then cooled to 80 ° C., treated with activated carbon and filtered. After removal of the solvent at 120 ° C. and 2 mbar, 1800 g of a colorless organopolysiloxane were obtained with the following properties: Viscosity (25 ° C): 140 mm² / s Refractive index (25 ° C): 1.418 Epoxy number: 0.16 [equiv./100 g]

Example 3:

Production of

690 g (5.5 mol) of 3,4-epoxycyclohexylethylene were placed together with 530 g of isopropanol, 5.3 g of powdered Na₂CO₃ and 10 ml of a solution of 1% by weight of hexachloroplatinic acid in isopropanol and flushed with nitrogen for 15 min. The mixture was then heated to 90 ° C. with constant stirring (reflux) and slowly 1500 g of a trimethylsilyl-end-blocked liquid dimethylmethylhydrogensiloxane copolymer with a viscosity of 12 mm² / s (25 ° C.) and an Si-H content of 62.2 cm³ H² / g added dropwise. Nitrogen purging was continued. After the metering had ended (about 1 h), the mixture was refluxed for a further 2 hours and the residual Si-H content was checked at regular intervals, which decreased to a maximum of 0.05 cm³ H₂ / g. It was then cooled to 80 ° C., treated with activated carbon and filtered. After Removal of the solvent at 120 ° C. and 2 mbar gave 2100 g of a colorless organopolysiloxane with the following properties: Viscosity (25 ° C): 60 mm² / s Refractive index (25 ° C): 1,424 Epoxy number: 0.21 (equiv./100 g)

Example 4:

Preparation of a cleaning and / or conditioning agent for glass ceramic surfaces using the epoxy-functional organopolysiloxane described in Example 1 in the form of an oil-in-water emulsion with the following composition: Epoxy-functional organopolysiloxane (analogous to example 1) 20% by weight Linear dimethylpolysiloxane with a viscosity of 100 mm² / s at 25 ° C 2% by weight Liquid paraffinic hydrocarbon with boiling range 80-110 ° C 25% by weight Non-ionic emulsifier (e.g. octylphenol ethoxylate with approx. 10 ethylene oxide units) 8% by weight citric acid 3% by weight Alumina of particle size 1-100 microns 10% by weight water 30% by weight

The two organopolysiloxanes were mixed together with the liquid paraffinic hydrocarbon and the emulsifiers to form an oil phase, and the water was then slowly added with constant stirring. Finally, the citric acid and the alumina were dispersed.

In this way, a storage-stable, viscous oil-in-water emulsion was obtained.

Example 5:

Preparation of an oil-in-water emulsion with the same composition as given in Example 4, with the difference that the product prepared in Example 2 was used as the epoxy-functional organopolysiloxane.

Example 6:

Preparation of an oil-in-water emulsion with the same composition as given in Example 4, with the difference that the product prepared in Example 3 was used as the epoxy-functional organopolysiloxane.

Examples 7: (Comparative example )

Viskosität (25 °C): 50 mm²/s Aminzahl [m equiv./g]: 1,4 Preparation of an oil-in-water emulsion with the same composition as given in Example 4, with the difference that instead of an epoxy-functional organopolysiloxane, an amino-functional organopolysiloxane with the following structure was used:

Viscosity (25 ° C): 50 mm² / s Amine number [m equiv./g]: 1.4

Example 8:

Preparation of a water-in-oil emulsion using the epoxy-functional organopolysiloxane described in Example 1 with the following composition: Epoxy-functional organopolysiloxane (analogous to example 1) 10% by weight Cyclic dimethylpolysiloxane with a viscosity of 5.0 mm² / s at 25 ° C (decamethylcyclopentasiloxane) 15% by weight Isopropanol 4% by weight Polydimethylsiloxane-polyoxyalkylene copolymer 1.5% by weight Nonylphenol ethoxylate with approx. 4 ethylene oxide units 0.5% by weight Polishing clay with a particle size of 1-100 µm 10% by weight water 59% by weight

The epoxy-functional organopolysiloxane was mixed homogeneously with the cyclic organopolysiloxane and the polydimethylsiloxane-polyoxyalkylene copolymer. The isopropanol and then a mixture of water, nonylphenol ethoxylate and polishing clay were incorporated into the resulting oil phase with constant stirring.

A storage-stable, viscous water-in-oil emulsion was obtained.

Example 9:

Comparative testing of cleaning and conditioning effects.

Execution:

Approx. 1 g of the care product was applied to a lightly soiled decorative glass ceramic test plate measuring 28 cm x 28 cm and evenly distributed. The plate was then polished in a circular motion with a household cloth until the surface appeared streak-free.

At this point, the cleaning effect and the grip of the protective film were assessed.

Then, to check the protective effect, the surface was sprinkled with an approximately 3 mm high layer of sugar and heated until the sugar completely caramelized or carbonized. After cooling, the adhesion of the caramelized sugar, the ease and completeness of detachment from the surface as well as the surface quality with regard to damage (clod breakage) were assessed.

To check the wet wiping strength of the protective film, part of the pretreated surface was wiped with a wet household cloth before the sugar test and the sugar content was repeated in the manner described above.

The results are summarized in Table 1. Table 1 example 4th 5 6 7 8th Storage stability at 4o ° C very well Good Good bad Good Polishability very well Good Good medium very well Cleaning effect Good Good Good Good Good Grip Good Good Good medium very well Wet wipe resistance Good Good Good Good very well Protective effect (separation effect and surface quality) very well medium Good bad (partly plaice break) very well

Claims (7)

1. Use of an agent containing organopolysiloxane for cleaning and / or conditioning glass ceramic surfaces, characterized in that the organopolysiloxane has epoxy groups. 2. Use of an agent according to claim 1, characterized in that the epoxy-functional organopolysiloxane consists of units of the general formulas

composed, whereby
R each independently represent a hydrocarbon group and Q an epoxy-functional group,
a for 1, 2 or 3,
b for 0, 1 or 2,
c for 1 or 2,
d for 0, 1 or 2,
e for 1 or 2 and
f stand for 1 or 2 and
the sums of b and c and of d, e and f are each not greater than 3. 3. Use of an agent according to claims 1 or 2, characterized in that epoxy-functional organopolysiloxanes of the formula
(CH₃) ₃SiO [(CH₃) ₂SiO] _x [R¹ R²SiO] _y [QCH₃SiO] _z Si (CH₃) ₃
used, where
R¹ and R² are alkyl, aryl or alkaryl and Q of the formula

corresponds, where A is alkyl, alkoxyalkyl, aryl or alkaryl and the sum of x, y and z is less than 500. 4. Composition according to one or more of claims 1 to 3, characterized in that in addition to 5-30 wt .-% epoxy-functional organopolysiloxane as further components (B) 0-30 wt .-% non-reactive organopolysiloxane,
(C) 1-20% by weight of surfactant,
(D) 0-50% by weight organic solvent,
(E) 5-25% by weight of abrasive,
(F) 0-10% by weight of an acidic component,
(G) 0-10% by weight of additional additives selected from the group of thickeners, preservatives, colorants and fragrances and
(H) 1-89 wt% water
are included. 5. Composition according to claim 4, characterized in that it is in the form of an oil-in-water emulsion. 6. Composition according to claim 4, characterized in that it is in the form of a water-in-oil emulsion.