Patent Application
20130035267
1. Field of the Invention
This invention relates to the use of water-based lubricants for textile machines, in particular, the use as needle oils and/or sinker oils in textile knitting machines.
2. Description of Related Art
Lubricants that must meet high requirements are used for lubricating textile knitting machines. The compositions of a needle oil or sinker oil should have a constant viscosity at different machine speeds and temperatures. In this case, the operating viscosity of the lubricant should lie in the range of ISO VG 15-ISO VG 100. The compositions of the needle or sinker oils, moreover, should be resistant to aging.
The lubricants are to be present in the form of a colorless and clear solution as possible. These colorless lubricants are to have a good-to-excellent scourability, i.e., washing out ability; in particular, it should be possible to scour the lubricants at low temperatures. When a lubricant can be scoured only incompletely, it results in problems in the subsequent treatments of knit fabrics. In particular, a uniform dyeing of the knit goods is no longer possible, and irreversible color defects are the result.
In addition, the lubricants are also to have a long shelf life even at low temperatures without the formation of precipitates. The formation of precipitates can result in the clogging of the oil supply systems of the knitting machines.
The lubricant also must not have a tendency toward phase separation over the overall service temperature range of 0° C. to 80° C. The phase separation of the lubricant can result in a deficient lubrication of the machine parts, and thus, can result in unevenness of the knit fabric, which also can result in defects in the knitwear in the subsequent color treatment.
In addition to good protection against wear and tear and erosion, the lubricant must also provide the lowest possible level of friction. This results in a considerable energy savings and in reducing the noise level, which in turn results in improving work conditions.
In addition, the lubricant has to be slightly biodegradable, since the lubricant can get into the waste water via the scouring process and correspondingly has to be treated and decomposed via the clarification process.
The textile oils that are used over time, which are present in the form of an emulsion, in most cases are composed of more than 80% mineral oil, to which the usual wear-protecting and corrosion-protecting additives are added. In addition, emulsifiers are added to improve the scourability. In this connection, both anionic emulsifiers (e.g., sulfonates) and nonionic emulsifiers (e.g., fatty alcohol ethoxylates or else NPE), as well as cationic emulsifiers (e.g., quaternary ammonium compounds) can be used. At times, small amounts of water (less than 1%) have to be added to emulsifier-containing textile oils to stabilize them or reduce their tendency toward precipitation. Higher concentrations of water result in unacceptably high cloudiness by forming an emulsion, which results in phase separation, or can produce hydrolysis of the additives that are used.
In addition, it is known to apply a lubricating agent to textile yarns by a roller, which runs over the corresponding yarn, being immersed in a lubricating agent emulsion to facilitate the processibility of the yarns. To this end, a composition that contains 50 to 80 parts by weight of poly(oxyethylene-oxy-1,2-propylene)glycol, 10 to 40 parts by weight of emulsifier, and 10 to 40 parts by weight of an ester is described in U.S. Pat. No. 3,338,830. This mixture is present as a concentrate and is diluted with water, so that 1 to 25% by weight of non-aqueous components is present and is used in the form of an aqueous emulsion. From German Patent DE 30 08 500 C2 and corresponding U.S. Pat. No. 4,250,046, a water-soluble metal-working fluid that contains diethanol disulfide and one or more water-soluble polyoxyalkylene glycols are known. This liquid is used for working metals, whereby maximum pressure and anti-friction properties are ensured by preparing a sufficient amount of liquid.
The object of this invention is to prepare a liquid water-based lubricant for textile machines, with which the above-mentioned drawbacks, which develop when a mineral oil is used, are overcome, and which is present in the form of a solution.
So that the lubricant can be used in textile machines, it should be biodegradable, and it should be scourable at the lowest possible temperatures as well as used in an overall service temperature range without phase separation, should offer good protection against wear and tear and corrosion, and should have as low a friction level as possible.
According to the invention, a water-based lubricant for textile knitting machines, which contains 5 to 50% by weight of water-soluble polymer and/or 5 to 50% by weight of emulsifier add water up to 100% by weight, is therefore used.
In addition, the lubricant can also contain 0 to 15% by weight, in particular 2 to 5% by weight, of corrosion-reducing and protecting, respectively agent; 0 to 10% by weight, in particular 0.2 to 5% by weight, of wear-reducing and protecting, respectively agent; 0 to 1% by weight, in particular 0.01 to 0.75% by weight, of biocide; and 0 to 50% by weight, in particular 2 to 25% by weight, of an anti-icing agent.
The water-soluble polymer that is contained in the lubricant is selected from the group that consists of polyalkylene glycols, in particular polyethylene glycol with molar masses of 1,000 to 35,000, water-soluble esters, polyacrylates, polymethacrylates, polyvinyl pyrrolidones, polyacrylamides, carboxymethyl cellulose, polyanionic cellulose, hydroxy cellulose, and hydroxyethyl cellulose.
The emulsifier that is contained in the lubricant is selected from the group that consists of nonionic, anionic and cationic emulsifiers, in particular alkylene oxide polymers, sulfonates, carboxylic acid and dicarboxylic acid derivatives with a chain length of 6 to 16 carbon atoms, phosphate esters, and quaternary ammonium compounds.
The corrosion-protecting and wear-protecting agent that is contained in the lubricant is selected from the group that consists of water-soluble phosphorus and/or sulfur compounds, and nitrogen compounds, the biocide is benzoic acid, and the anti-icing agent is selected from the group that consists of low-molecular glycols, in particular ethylene glycol, propylene glycol, trimethylene glycol, glycerol, salts or ionic liquids.
The lubricant according to the invention can also be used in the form of a concentrate. In this case, primarily the reduced goods traffic is advantageous, since the finished formulation can be produced directly by customers by dilution with water. Moreover, the storage space that is required at the user site is reduced. Besides, the user can adjust the lubricant directly to the desired viscosity for its application.
To ensure that the lubricant is biodegradable, can be scoured, i.e. washed out at the lowest possible temperatures, can be used in the overall service temperature range without phase separation, offers good protection against wear and tear and corrosion, and has as low a friction level as possible, water is used as a carrier liquid. Special water-soluble additives, such as polyalkylene glycol and/or water-soluble esters, are added to this carrier liquid, and then the corresponding operating viscosity is set between ISO VG 15-ISO VG 100.
In this connection, it is pointed out expressly that the examples below do not involve any emulsions, but rather true clear aqueous solutions. The application is exclusively the lubrication of machines or machine parts and not the lubrication/finishing of yarns.
The advantageous properties of the lubricant according to the invention are shown based on the subsequent examples and the comparison example.
The lubricant has the following composition:
Table 1 shows the results of the studies of the properties of the lubricating agent according to the invention in accordance with the invention compared to that of a known mineral-oil-based lubricating agent.
The KLM test is performed as follows:
In a Petri dish (diameter 80 mm), an acetone-purified knitting needle (length 44 mm) is placed on a round filter (filter paper with a diameter of 55 mm, Whatman) and covered with 10 ml of aqueous textile oil. After 48 hours of storage at room temperature, the needle (black spots) and the filter paper (yellow-red coloring) are checked for corrosion.
The study results shown in Table 1 can be summarized as follows. The lubricant that is produced according to the invention is a virtually colorless, limpid solution. The complete scourability is itself added without washing agents at low temperatures, which makes possible a considerable savings in energy. The friction level that is drastically reduced in comparison to the conventional needle oils allows one to expect a clearly improved energy efficiency as well as a lower noise level and extended holding times during operation. By the exchange of mineral oil or a basic oil corresponding to the latter by water, a greater focus is placed on durability with the lubricant of this invention.
In Table 2, the properties of the formulations of Example 2 and 3 are listed.
Also here, the comparison with the comparison example shows the excellent properties of the use according to the invention of a water-based lubricant according to Examples 2 and 3.
In Table 3, the properties of the formulations of Examples 5 and 6 are listed.
Advantageously, the water that is used can be used both in the distilled, demineralized form and as tap water, which simplifies a possible application in the form of a concentrate.
To achieve the required operating viscosity of ISO VG 15-ISO VG 100, it may be necessary to adjust the aqueous lubricant to a lower viscosity. By evaporating a portion of the water at the friction site, the target viscosity is then achieved.
The emulsifiers that are optionally contained in the lubricant comprise all non-ionic, anionic and cationic systems from the cleaning agent industry and the metal-working industry.
Examples of the nonionic emulsifiers that are used are alkylene oxide polymers, such as alcohol ethoxylates that consist of, e.g., ethylene oxide and/or propylene oxide with alkylene oxide units of 5-50 and linear or branched alkyl radicals with a chain length of C10 to C20.
Examples of anionic emulsifiers are sulfonates, carboxylic acid and dicarboxylic acid derivatives with a chain length of 6 to 16 carbon atoms, as well as phosphate esters.
Examples of cationic emulsifiers are quaternary ammonium compounds.
Water-soluble polymers comprise polyalkylene glycols, whereby polyethylene glycols with molar masses of 1,000 to 35,000 are preferred. Moreover, water-soluble esters, such as, for example, polyacrylates or polymethacrylates, can be used, as well as polyvinyl pyrrolidones or polyacrylamide, cellulose or sugar derivatives, in particular carboxymethyl cellulose, polyanionic cellulose, hydroxycellulose, and hydroxyethyl cellulose. The desired viscosities can be set by different molecular weights of the polymers.
Typical usable corrosion- and wear-protecting additives originate from the (cool)lubricant industry and comprise phosphorus-containing and/or sulfur-containing water soluble compounds as well as boron compounds, such as boric acid derivatives, or nitrogen compounds, such as, e.g., triazole derivatives or VCIs (volatile corrosion inhibitors, e.g., secondary amines).
To avoid bacterial growth in the aqueous solution accompanied by sludge formation, bactericides can be added, e.g., benzoic acid. To improve the low-temperature behavior, anti-icing agents, such as low-molecular glycols, in particular ethylene glycol, propylene glycol, trimethylene glycol, glycerol, salts or ionic liquids, can be used.
The advantages of the lubricant according to the invention can be listed as follows:
They can be scoured, i.e., washed out with tap water at room temperature without washing agents, thus energy is saved in the washing process,
Water pollution is significantly reduced by the elimination of mineral oil and washing agent; a clarifying step can be eliminated.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2010 015 757.0 | Apr 2010 | DE | national |
| 10 2011 016 818.4 | Apr 2011 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP11/01961 | 4/18/2011 | WO | 00 | 10/18/2012 |
