Patent Application
20060046940
This invention relates generally to an aqueous conveyor and cutting lubricant that demonstrates greatly improved lubricity, and more particularly relates to a lubricant that employs a combination of polyamines, and an alkoxylated alcohol nonionic surfactant. The present invention may be used to lubricate conveyor chains in bottling plants and canneries, and may be applied directly to saw blades, files and cutters.
In bottling plants, containers to be filled (e.g., glass and plastic bottles) are transported by conveyors such as platform conveyors or chain-like arrangements, generally referred to as chain conveyors. The different stages in the bottling process such as, for example, bottle washing, filling, closing, labeling, and packing, are connected by way of these chain conveyors. In order to assure uninterrupted operation, the conveyor chains have to be suitably lubricated to avoid excessive friction with the containers. Lubricants containing suitable friction-reducing ingredients are normally used for this purpose. The chain conveyors are typically contacted with the lubricants by dipping or spraying. As will be readily appreciated by those skilled in the art, inadequate lubrication of chain conveyors, which are known to adopt somewhat tortuous paths within bottling plants, tends to cause containers such as glass bottles to fall off the conveyors and break.
Lubricants including certain amine compounds are known. For example, U.S. Pat. No. 5,900,392 to Laut Bernhard describes an aqueous belt lubricant composition that is formulated as a dilutable concentrate. The dilutable concentrate basically comprises:
The fatty alcohol polyglycol ether reportedly acts as an antifoaming agent in the aqueous belt lubricant composition, with most preferred chain length distributions for the alkyl group of the fatty alcohol being identified as C12 to C14 or C16 to C18 alkyl groups.
Dilutable concentrates formulated in accordance with the teachings of U.S. Pat. No. 5,900,392 have been found to have relatively short shelf lives, separating after only one to three months in storage. Moreover, suitable lubricity has been achieved by the disclosed belt lubricant composition only at relatively high dilution ratios of about 1:250 or 0.4%.
By way of the present invention, a dilutable concentrate with extended shelf life for use in preparing an aqueous conveyor and cutting lubricant that demonstrates greatly improved lubricity, is provided.
The present invention more particularly provides a dilutable concentrate that comprises: a combination of tallow di-, tri- and tetramines; at least one acid in an amount sufficient to establish a pH value of from about 3.0 to about 6.0; an alkoxylated alcohol nonionic surfactant; balance water.
In a preferred embodiment, the inventive dilutable concentrate comprises:
In a more preferred embodiment, the inventive concentrate comprises:
Other features and advantages of the invention will be apparent to one of ordinary skill from the following detailed description.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. All publications, patent applications, patents and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.
As alluded to above, by way of the present invention, the inventors have made the surprising discovery that the use of a combination of polyamines, and an alkoxylated alcohol nonionic surfactant in a dilutable concentrate used to prepare an aqueous conveyor and cutting lubricant effects a surprising and unexpected increase in the lubricating properties demonstrated by the lubricant.
The aqueous conveyor and cutting lubricant of the present invention can be used on stainless steel and plastic conveyor chains in bottling plants and canneries, and demonstrates greatly improved lubricity when used with beverage and food containers such as aluminum cans, glass bottles, and PET containers. The inventive lubricant may also be applied directly to saw blades, files and cutters.
In addition to the greatly improved lubricating properties demonstrated by the conveyor and cutting lubricant of the present invention, the inventive lubricant is low foaming and has good cleaning, dispersant and lubricating properties that are unaffected by water hardness. In addition, the inventive dilutable concentrate demonstrates increased shelf life in that the concentrate will not separate even when stored for periods of more than three (3) months.
In a preferred embodiment, the inventive lubricant is antimicrobial or biocidal, thereby serving to, among other things, reduce or prevent formation of black slime on conveyor chains and nozzle blockage due to polysaccharide formation.
As noted above, the inventive lubricant is prepared from a dilutable concentrate that comprises: a combination of tallow di-, tri- and tetramines; at least one acid in an amount sufficient to establish a pH value of from about 3.0 to about 6.0; an alkoxylated alcohol nonionic surfactant; balance water.
Tallow diamines contemplated for use in the present invention include, but are not limited to, N-Tallow alkyl trimethylene diamine, N-(3-aminopropyl)-N-tallow alkyltrimethylenediamine, N-(Tallowalkyl)-1,3-propanediamine, N-oley-1,3-diaminopropane, N-tallowalkyl-1,3-diaminopropane dioleate, N,N,N′-trimethyl-N′-tallowalkyl-1,3-diaminopropane, Tris (2-hydroxyethyl)-N-tallowalkyl-1,3-diaminopropane, polyoxyethylene (10) N-tallowalkyl-1,3-diaminopropane, and mixtures thereof. In a preferred embodiment, the tallow diamine is N-Tallow alkyl trimethylene diamine, which is available from Tomah Products, Inc., 337 Vincent Street, Milton, Wis. 53563 (“Tomah Products”), under the product designation tallow diamine.
Suitable tallow triamines include, but are not limited to, N-Tallow alkyl dipropylene triamine, N-(3-aminopropyl)-N-tallow alkyltrimethylenediamine, and mixtures thereof. In a preferred embodiment, the tallow triamine is N-Tallow alkyl dipropylene triamine, which is available from Tomah Products, under the product designation tallow triamine.
Suitable tallow tetramines include, but are not limited to, N-Tallow alkyl tripropylene tetramine, which is available from Tomah Products, under the product designation tallow tetramine.
The tallow amines are present in the inventive dilutable concentrate in an amount ranging from about 3 to about 45% by wt., based on the total weight of the concentrate. In a preferred embodiment, the tallow amines are employed in amounts ranging:
It has been found that a combination of tallow di-, tri- and tetramines and in particular, the noted combination within the ranges identified above, results in an increase in the lubricating properties demonstrated by the aqueous conveyor and cutting lubricant of the present invention.
All component ranges specified herein are % by wet weight, based on the total wet weight of the dilutable concentrate.
Acids used in the inventive dilutable concentrate serve to establish a pH value in the concentrate which ranges from about 3.0 to about 6.0 (preferably, from about 3.0 to about 4.5) and include, but are not limited to, organic acids such as acetic acid and glacial acetic acid. It is noted that pH levels of from about 3.0 to about 4.5 are preferred where excess acidity in the dilutable concentrate will serve to counter any excess alkalinity found in feed waters used in bottling plants.
In a preferred embodiment, the acid is glacial acetic acid, which is available from Eastman Chemical Company, 100 North Eastman Road, P.O. Box 511, Kingsport, Tenn. 37662-5075.
The acid(s) is present in the dilutable concentrate of the present invention in an amount ranging from about 3 to about 12% by weight, preferably from about 4 to about 8% by weight, and more preferably from about 5 to about 8% by weight, based on the total weight of the concentrate.
The alkoxylated alcohol nonionic surfactant used in the dilutable concentrate of the present invention is a compound produced by the condensation of one or more alkylene oxides (hydrophilic moiety) with one or more alcohols (hydrophobic moiety), which can be aliphatic, alkyl or alkyl aromatic in nature.
Examples of suitable alkoxylated alcohol nonionic surfactants include condensation products of one or more alkylene oxides with aliphatic alcohols. The alkyl chain of the aliphatic alcohol may be either straight or branched. The polyether can be end capped with acyl groups including, for example, methyl and benzyl groups.
Suitable alkoxylated alcohols are available from:
In a preferred embodiment, the alkoxylated alcohol nonionic surfactant is an ethoxylated/propoxylated alcohol comprising a condensation product of ethylene oxide and propylene oxide with one or more fatty alcohols having alkyl chains of less than 12 (preferably, from 6 to 10) carbon atoms. In a more preferred embodiment, the nonionic surfactant is a C6 to C10 linear alcohol alkoxylate or C6 to C10 fatty alcohol polyglycol ether, which is available from BASF Corp., under the product designation PLURAFAC SLF-18 low-foaming Linear Alcohol Alkoxylate.
The alkoxylated alcohol nonionic surfactant is present in the dilutable concentrate of the present invention in an amount ranging from about 1 to about 10% by weight, preferably from about 2 to about 6% by weight, and more preferably from about 3 to about 5% by weight, based on the total weight of the concentrate.
In addition to the above components, the inventive dilutable concentrate may advantageously contain other additives such as antimicrobial compounds, cationic surfactants, antifoaming agents (e.g., silicone and surfactant based antifoaming agents), and phosphate esters (e.g., aliphatic organic phosphate ester, alkyl ether phosphate, alcohol ethoxylate phosphate ester, potassium salt).
Examples of suitable antimicrobial compounds include, but are not limited to, isothiazolin-3-ones such as 5-chloro-2-methyl-4-isothiazoline-3-one, 2-bromo-2-nitropropane-1,3-diol, 1,2-benzoisothiazol-3(2H)-one, hexahydro-1,3,5-tris(2-hydroxyethyl)-s-triazine, and mixtures thereof.
In a preferred embodiment, the antimicrobial compound is 5-chloro-2-methyl-4-isothiazoline-3-one, which is available from Nashville Chemical & Equipment Co., Inc., 7001 Westbelt Drive, Nashville, Tenn. 37209.
The antimicrobial compound is present in the dilutable concentrate of the present invention in an amount ranging from about 0 to about 5% by weight, preferably from about 0.5 to about 2% by weight, and more preferably from about 1 to about 2% by weight, based on the total weight of the concentrate.
Examples of suitable cationic surfactants include, but are not limited to, quaternary ammonium compounds, such as alkyl dimethyl benzyl ammonium chloride, alkyl dimethyl ethyl benzyl ammonium chloride, alkyl trimethyl ammonium chloride, and dialkyl dimethyl ammonium chloride, didecyl dimethyl ammonium chloride, and mixtures thereof.
In a preferred embodiment, the cationic surfactant is alkyl dimethyl benzyl ammonium chloride, which is available from Lonza, Inc., 17-17 Route 208, Fair Lawn, N.J. 07410, under the product designation UNIQUAT QAC-80 alkyl dimethyl benzyl ammonium chloride.
The cationic surfactant is present in the dilutable concentrate of the present invention in an amount ranging from about 0 to about 5% by weight, preferably from about 1 to about 4% by weight, and more preferably from about 1 to about 3% by weight, based on the total weight of the concentrate.
The dilutable concentrate of the present invention, in a preferred embodiment, comprises:
In a more preferred embodiment, the inventive concentrate comprises:
The inventive concentrate may be prepared by first heating water to a temperature ranging from about 50 to about 70° C. The tallow amines are then liquefied and added to the heated water to form a solution. The acid(s) is added to the solution to water solubilize the tallow amines, and the resulting mixture maintained within the temperature range noted above, with agitation, for approximately two (2) hours. The mixture is then allowed to cool, and when the temperature of the mixture is below about 45° C., the alkoxylated alcohol(s), antimicrobial compound(s), and cationic surfactant(s) are added and the mixture agitated for an additional hour. In the final formulation, the tallow or fatty amines are neutralized by the acid(s) forming tallow amine acetates.
The dilutable concentrate of the present invention having a pH ranging from about 3.0 to about 6.0 (preferably, from about 3.0 to about 4.5) is diluted with water prior to use. The inventive concentrate may be diluted 300 to 0.500 times (resulting in a dosage ranging from about 0.33 to about 0.2%), and up to 1000 times (resulting in a dosage of at least about 0.1%), for conveyor chain end use applications.
The resulting aqueous lubricant may be sprayed through nozzles onto stainless steel and plastic conveyor chains where it reduces friction between beverage and food containers and the conveyor chain allowing for smoother and more consistent transport. The inventive lubricant may also be applied directly to saw blades, files and cutters.
While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of the present invention should not be limited by any of the exemplary embodiments.
