DE102016001519A1 - Water-based lubricants for conveyor belts - Google Patents

Abstract

The invention relates to water-based lubricants for conveyor belts. In particular, the invention relates to water-based lubricants for conveyor belts for the beverage industry.

Description

The invention relates to water-based lubricants for conveyor belts. In particular, the invention relates to water-based lubricants for conveyor belts for the beverage industry.

Lubricants for conveyor belts for the beverage industry must meet high requirements, in particular with regard to their suitability for food and compatibility. For lubrication of conveyor belts in bottling lines of the beverage industry, either lubricating oils are used or emulsions / dispersions, which are diluted to varying degrees with water, depending on the application technology. The WO 2007/040678 A1 describes such a concept. It is a silicone emulsion that is diluted with water. Depending on the degree of dilution one then speaks of a "wet" or "semidry" lubrication. In the case of a "wet" lubrication with typical dilutions of the lubricant from 1: 100 to 1: 1000, the water consumption is very high. At a dilution of less than 1: 100 one speaks of "semidry" lubrication. In both cases, it should be noted that the hardness of the added water has a decisive influence on the performance and compatibility of the lubricant with the transported packaging material. Accordingly, typically increased amounts of free organic acids must be added to a "wet" or "semidry" lubricant to neutralize the water hardness alkalinity. A disadvantage of emulsions or suspensions, however, is that agitators are often required when mixing with water and they have a poorer storage stability than homogeneous solutions. In addition, it is not possible to realize a closed film of lubricating component on the transport chain, which adversely affects the tribological properties. Common to all these lubricants is the relatively expensive cleaning of the conveyor belts.

An object of the present invention was therefore to provide a tribologically highly effective lubricant formulation which is effective in very small amounts and does not need to be further diluted with water. Thus, a maximum of water savings is possible. In addition, the formulation of the invention is biodegradable and applicable in the food industry. The formulation is also storage stable, completely soluble in water and easy to remove from the conveyor belts.

These objects are achieved by providing a water-based lubricant composition having a water content of 50 to 96% by weight, 4 to 40% by weight of at least one viscosity-providing component and 0.05 to 10% by weight of preservative, anti-pollution substances includes. There are no solids and no water-insoluble components.

The water-based lubricant composition of the invention is readily biodegradable and environmentally friendly in an aqueous environment. In addition, it is characterized by good compatibility with application-relevant materials, such as chain materials, application technology and packaging. The low-temperature behavior of the aqueous lubricant composition according to the invention can be improved by the addition of antifreeze, for. As low molecular weight glycol or glycerol can be significantly improved. Furthermore, additives can be added in order to specifically influence the properties of the lubricant composition according to the invention. If desired, the aqueous lubricant compositions according to the invention may also be formulated foam-free.

The lubricant composition according to the invention comprises from 4 to 30% by weight of at least one viscosity-providing component and from 0.05 to 10% by weight of preservative, pollution-inhibiting substances, the remainder being water.

In addition, the lubricant composition of the invention
0.05 to 15% by weight antifreeze,
0.05 to 15% by weight corrosion inhibitor,
0.05 to 5% by weight defoamer,
0.05 to 5 wt.% Wetting agent,
From 0.05% to 5% by weight of biocides,
0.005 to 2 wt .-% fragrances
contain.

The viscosity-providing component of the lubricant composition according to the invention is selected from the group consisting of water-soluble carboxylic acid esters, or a mixture of water-soluble carboxylic acid radicals and low molecular weight polyalkylene glycols. It is preferable to use water-soluble ethoxylated esters of dicarboxylic acids which have been named Nycobase 618 of the Company Nyco SA. The low molecular weight polyalkylene glycols used are preferably a polyethylene glycol having the average molar mass of 200-600, which are sold by Clariant Deutschland GmbH under the name PG 200-600.

For low temperature applications, the lubricant composition of the invention may contain an antifreeze selected from the group consisting of monohydric and / or polyhydric alcohols and / or alcohol derivatives, e.g. As glycerol or 1,2-propanediol.

Neutralizing and unneutralized carboxylic acids, neutralized phosphoric acids and / or phosphoric acid derivatives, benzoic acid and / or benzoic acid derivatives, triazoles, alcohol amines, glycolamines are used as corrosion inhibitors for the lubricant composition according to the invention.

As a wear-protective agent, water-soluble compounds containing sulfur, phosphorus and / or nitrogen, such as salts of sulfonic acid derivatives and thiols are used.

To prevent foaming additives such. As polydimethylsiloxanes or polymers of acrylate derivatives can be used.

Depending on the application, the lubricant composition according to the invention may comprise emulsifiers and / or wetting agents, for example foaming or non-foaming emulsifiers from the class of ionic (eg sulphonates) and nonionic (eg fatty alcohol ethoxylates) surfactants, alkylene oxide polymers, phosphate esters and quaternary ammonium compounds, alkoxylated silicones and silicone derivatives as well as carboxylic acid derivatives.

In addition, the lubricant composition of the invention biocides, such as. B. isothiazolone derivatives.

Also, depending on the application, the use of fragrances is possible, which are selected from the group consisting of alcohols, aldehydes, ketones, esters, alkenes, salts z. As copper salts and / or zinc sulfates.

The lubricant composition according to the invention preferably comprises 5 to 20% by weight of viscosity-providing compound and 0.05 to 10% by weight of preservative substances which protect against contamination and 0.05 to 5% by weight of wear protection agent, the remainder being water.

Most preferably, the lubricant composition of the present invention comprises from 7.5 to 15% by weight of viscosity-providing compound and from 0.05 to 10% by weight of preservative, anti-soiling substances, and from 0.1 to 1.5% by weight of anti-wear agent, the remainder Water.

With the lubricant composition according to the invention it is ensured that the performance of the lubricant is not significantly affected by production-related Abdusche with water.

The lubricant composition according to the invention is further characterized by an excellent sprayability, which can also be applied in non-pressurized nozzles and the risk of clogging of nozzles is minimized. In addition, the application with all common methods, such as with or without compressed air operated nozzles, brushes, sliding plates) is possible.

The lubricant composition of the invention also provides excellent wear protection in all common chain material packaging combinations, z. For example, pairing can plastic chain, tetrapack plastic chain, PET (disposable and reusable) plastic chain or steel chain, glass bottle plastic chain or steel chain.

The lubricant composition according to the invention has excellent compatibility with common packaging, chain materials and application techniques. In addition, when using the lubricant composition according to the invention, a significant improvement in the storage and transport stability, with regard to the influence of temperature and vibration, is achieved.

The lubricant composition of the present invention is also excellent in biodegradability.

Hereinafter, the lubricant composition of the present invention will be described in detail by way of examples.

Examples

The preparation of the example formulations is carried out by mixing the majority of the individual components by means of a stirrer and heating to 70 ° C for 30 min and then cooling and stirring the temperature-critical constituents. Example 1: Viscosity-giving component: Nycobase 618 9.27% Wear protection: MPS 0.39% Deion. water 90.34% Example 2: Viscosity-giving component: Nycobase 618 10.0% Wear protection: MPS 0.4% biocide: Acticide MBS 0.10% defoamers: ES 561 1.0% Corrosion protection: M 528 L 2.0% Deion. water 86.5% Example 3: Viscosity-giving component: Nycobase 618 9.27% Preservative, against pollution protective components: SurTec 192 0.5% SurTec 055 1.0% Deion. water 89.23% Example 4: Viscosity-giving component: Nycobase 618 10.0% Viscosity-giving component: PG 200 2.5% Wear protection: Lubio EP 1 0.5% biocide: Acticide MBS 0.15% Wetting agent: Hydrolite 5 0.9% defoamers: ES 561 1.0% Corrosion protection: M 528 L 7.0% Deion. water 77.95% Example 5: Viscosity-giving component: Nycobase 618 10.0% Frost protection: glycerin 2.5% Wear protection: Lubio EP 1 0.5% biocide: Acticide MBS 0.2% defoamers: ES 561 1.0% Deion. Wsaser 85.8% Example 6: Viscosity-giving component: Nycobase 618 9.27% Wear protection: MPS 0.39% Preservative, against pollution protective components: Redokon CDD AH 0.014% Redokon CDD B 0.001% Deion. water 90.325%

The components used are, as already mentioned above PG 200, Nycobase 618. Further, M 528 L is used, which is a mixture of various neutralized organic and inorganic acids marketed by Cortec Corporation. Surtec 192 is a mixture of phosphates, silicates and amino-neutralized organic acids available from SurTec Deutschland GmbH. SurTec 055 is a mixture of amines, silicates and hydrocarbons as well as anionic and non-ionic surfactants, also from SurTec Deutschland GmbH. Hydrolite 5 is a pentadiol from Symrise AG. MPS is a salt of organic sulfur compounds marketed by Raschig GmbH. Acticide MBS is a mixture of benzisothiazoles and methylisothiazolone from Firmas Thor GmbH. Lubio EP1 is a salt of an organic sulfur compound from Schäfer Additivsysteme GmbH. ES 561 is a silicon-containing defoamer from Additivchemie Luers GmbH. Glycerin is obtained from Brenntag GmbH. Redokon CDD A-H and Redokon CDD B are chlorine dioxide solutions from Redokon GmbH.

The above example formulations have now been tested for their effectiveness.

1. Wear protection

The SRV test (vibration-friction-wear) is a common test for quantifying the wear protection effect of lubricants. This is usually done on the material pairing steel - steel. In the present case, the material pairing POM (polyoxymethylene) steel was chosen for better transferability to the application. The wear rate was evaluated after a test period of 6 hours at a load of 95 N / mm ² . Table 1 product Wear rate [mm ³ / h] Interflon Fin Food lube AL (Drylube oil based from mineral oil with PTFE) 0.67 P3 Lubodrive RF (Drylube oil-based hydrocarbon resin) 1.72 Neomoscan G7 (wetlube water based from amine acetate) 0.69 example 1 0.04 Example 2 0.10

Table 1 shows that all three examples according to the present invention have significantly lower wear rates than commonly used products.

2. Spreading behavior

Good spreading behavior is essential in the case of minimum quantity lubrication for maintaining a continuous lubricating film. The spreading behavior is usually determined in the context of contact angle measurements on the relevant surface. The lower the contact angle, the better the wetting of the surface. Table 2 product Contact angle [°] on PBT after 15 s Example 4 38 Example 2 51 Lubostar CP (wetlube water-based silicones) 64

Table 2 shows that the examples of the present invention have significantly better spreading performance than the commonly used Wetlube Lubostar CP. The investigations were carried out on PBT, as a commonly used chain material.

3. Tests on conveyors different pairings

The check of the lubricity performance of the water-based example formulation was carried out on a standard Krones conveyor using various relevant material combinations at room temperature and a typical chain speed of 0.8 m / sec. The friction coefficients were determined in each case on an original sealed 1 l glass water bottle, a 1.5 l PET disposable bottle and a 1.5 l TetraPack. The drums on the conveyor chain were fixed to a spring balance with a cord. Table 3 Coefficient of friction averaged over 120 sec for different material pairings Steel / Glass POM / PET POM / Tetra Pack Example 2 0.11 0.09 0.15 Example 4 - 0.07 0.15

Usually, the friction coefficients of the different material pairings should be in the range of 0.05 to 0.20. Table 3 shows the good lubricity of the compositions tested.

With the lubricant composition of Example 3, to demonstrate excellent performance with minimal lubricant consumption, a 1.5 liter PET disposable bottle was tested over a period of 4 hours under the conditions described above. It was relubricated with 0.05 ml of lubricant every 5 minutes. The coefficient of friction was continuously 0.09 +/- 0.01 and is therefore within the ideal range for this combination of materials.

4. Corrosion protection

When using water-based lubricants instead of an oil-based dry lubricant, ensure sufficient corrosion protection of the application technology to protect components such as Zumess valves or spray valves. Typical corrosion protection tests are carried out by incorporating relevant components into the lubricant formulation at elevated temperature. Table 4 Resistance of non-stainless steel components of the application technology to the lubricant Anticorrosive additive Steel at 70 ° C after 14 days of storage Example 2 2% by weight reasonable Example 4 7% by weight Good example 1 0% by weight insufficient Neomoscan G7 no information from the manufacturer insufficient

Table 4 shows that sufficiently additive aqueous lubricant formulations can provide adequate protection for corrosion-prone application techniques.

5. Cleaning

Impurities in food containers must be avoided for hygienic and cosmetic reasons. Typical impurities are normal dusts, particles of packaging, leaking food, wear particles of chain and slide strip, as well as lubricant residues. Table 5 Additive for pollution prevention Protection against residue build-up on conveyor chain Example 3 available sufficient example 1 unavailable insufficient P3 Lubodrive RF no information from the manufacturer insufficient Neomoscan G7 no information from the manufacturer insufficient DryExx SF no indication of the (Drylube water based) manufacturer insufficient

On the lubricants listed in Table 5, the build-up of soiling was carried out both on the fly and during laboratory tests on an original PBT chain on the test conveyor. Surprisingly, a significant reduction of the residue structure was achieved in Example 3.

7. Defoamer

Excessive foaming when applying Conveyor lubricants should be avoided due to reduced tribological effectiveness. Foaming lubricants can also be applied worse, especially when using spray nozzles. The use of a defoamer in Example Formulation 5 visually showed a significant reduction in foaming tendency. Table 7 defoamers Defoaming effect visually at the conveyor Example 4 available sufficient example 1 unavailable insufficient

8. Clarity

All formulations of Examples 1 to 6 are clear solutions. Due to the homogeneity of the system, there are clear advantages in terms of storage and transport stability, uniform applicability without the use of stirrers, and avoidance of water-insoluble residues on the conveyor chain in the case of emulsions / suspensions. Table 8 Type Appearance example 1 solution clear Example 2 solution clear Example 3 solution clear Example 4 solution clear Example 5 solution clear Example 6 solution clear Lubostar CP emulsion cloudy Interflon Fin Food Lube AL suspension cloudy P3 Lubodrive RF solution clear Neomoscan G7 solution clear DryExx SF emulsion cloudy

9. Abduschung with water

The cleaning of conveyor chains usually requires a production stoppage because the frictional behavior is strongly influenced by the amount of water ordered and is typically worsened in the case of increased humidity. Also, it can not be ruled out that transported water bottles burst and this leads to a localized Abduschung the lubricant from the conveyor chain. Table 9 ΔCoF PET / PBT after flashing with excess of water (water: lubricant 500: 1) Example formulation 2 + 35% DryExx SF + 70%

Surprisingly, it has been found that the formulation according to Example 2, even at Abkuschung with 500 times the amount of water compared to the applied lubricant to the chain only leads to a moderate deterioration of the friction coefficient of 35%. This enables the uninterrupted filling operation in the event of malfunctions or in the cleaning, which was not the case in comparison with a known lubricant composition, since the coefficient of friction was deteriorated by 75%.

10. Applicability

The lubricant composition according to Example 5 could be applied by means of metering via metering valve or solenoid valve and subsequent application by means of sliding plate as well as by means of compressed air-operated or compressed air-operated nozzles. In particular, the possibility that the composition of Example 4 can be applied in minimal quantities by means of airless nozzles, this formulation differs from commonly used standard products, such as. Eg DryExx SF or P3 Lubodrive RF.

11. Compatibility with packaging, application technology and chain material

For further verification of the properties of the lubricating compositions of the present invention, incorporation tests on sealing material, tubing, tubing, nozzle components, pump diaphragms and solenoid valves of common application technique and POM chain material were carried out at 70 ° C for 4 weeks with Example Formulation 5. No material changes were detected.

For the package compatibility, originally filled 1.5 l PET disposable bottles, 1 l glass bottles, 0.5 l tin and 0.5 l TetraPack were placed on a glass surface wetted with the formulation according to Example 5 for 30 sec and then stored for 72 hours on a clean glass surface. Then was visually examined for material change, such as stress, cracking or discoloration. In no case abnormalities were observed.

12. Biodegradability

All of the example formulations mentioned are due to the high water content, as well as by the very good biodegradability of the viscosity generator used highly environmentally friendly and biodegradable.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2007/040678 A1 [0002]

Claims (8)

Water-based lubricant composition for conveyor belts comprising from 4 to 30% by weight of at least one viscosity-providing component, from 0.05 to 10% by weight of preservative, anti-pollution substances, ad water to 100% by weight, characterized in that the viscosity- providing component a water-soluble carboxylic acid ester or a mixture of a water-soluble carboxylic acid ester and a low molecular weight polyalkylene glycol. The lubricant composition of claim 1, further comprising one or more components selected from the group consisting of 0.05 to 5% by weight of wear protection agent, 0.05 to 15% by weight antifreeze, 0.05 to 15% by weight corrosion inhibitor, 0.05 to 5% by weight of wear protection agent, 0.05 to 5% by weight defoamer, 0.05 to 5 wt.% Wetting agent, From 0.05% to 5% by weight of biocides, 0.005 to 2 wt .-% fragrances. Lubricant composition according to claim 1, characterized in that a compound or mixture is selected from the group consisting of foaming or non-foaming emulsifiers from the class of ionic and nonionic surfactants as preserving, pollution-proof substances. Lubricant composition according to claim 2, characterized in that a water-soluble compound containing sulfur, phosphorus and / or nitrogen is selected as the wear protection agent. Lubricant composition according to claim 2, characterized in that a compound selected from the group consisting of monohydric and / or polyhydric alcohols, alcohol derivatives is used as antifreeze. The lubricant composition according to claim 2, characterized in that as corrosion inhibitors is a compound selected from the group consisting of neutralized and unneutralized carboxylic acids, neutralized phosphoric acids and / or phosphoric acid derivatives, benzoic acid and / or benzoic acid derivatives, triazoles, alcohol amines, glycol amines is used. The lubricant composition according to claim 2, characterized in that as defoamers a compound selecting from the group consisting of polysiloxanes, or polymers of acrylate derivatives, selecting a compound as wetting agents from the group consisting of ionic and nonionic surfactants, as biocidal isothiazolone derivatives and as fragrance a compound selected from the group consisting of alcohols, aldehydes, ketones, esters, alkenes, copper and / or zinc salts. Use of the lubricant composition according to one of the preceding claims in undiluted form or in a dilution of 1: 1000.