ES2208765T3 - USE OF A CLEANING FORMULATION AND PROCEDURE TO CLEAN BOTTLES. - Google Patents

Abstract

Use of an alkaline wash formulation, which includes an additive comprising: - a polyacrylate - sodium gluconate and - a wetting agent of the general formula R1 = (OC2H4) n = (OC3H8) m = OR2, in which R1 = a chain alkyl of length between C8 and C20, R2 = H, alkyl (C1 to C5) or benzyl, n = 1-20, and m = 0-15 for washing bottles.

Description

Use of a cleaning formulation and procedure To clean bottles.

The present invention concerns the use of a cleaning formulation comprising an additive, and a procedure for cleaning bottles, in particular bottles PET returnable, using such formulation.

Large quantities of drinks are sold, including carbonated soft drinks such as cola, in bottles returnable made of glass or plastic, particularly PET (poly (ethylene terephthalate)). These bottles are due Thoroughly clean and disinfect before refilling to ensure that the quality of the product is not adversely affected.

One of the biggest problems with the bottles of drinks after they have emptied is that mold can grow in the residual product and produce the characteristic pads of mold. These are difficult to eliminate because of the main component used in bottle washing detergents (caustic soda) a unless additional components are also present, to Know, chelating agents. The preferred chelating agent from the point of view of the removal of mold pads is the EDTA However, there is considerable pressure from the groups environmental and some governments to reduce or preferably eliminate the use of EDTA. An inconvenience Additional of EDTA is that it makes washing solutions of Bottles more likely to foam. This may affect adversely to the performance of the cleaning procedure unless that an antifoam agent be added. Such an addition is not only expensive, increases the polluting capacity of the dissolution of detergent and, as far as plastic bottles are concerned, you can increase the chemical damage of the bottles due to cracking by tension.

Instead of EDTA, an alternative chelating agent It is sodium gluconate. This one has the advantage of being easily biodegradable and does not increase the tendency to foam formation of Cleaning solutions However, it is a chelating agent weaker and does not remove mold pads so effectively such as EDTA, especially at relatively low caustic levels as required for low chemical damage when washing bottles of plastic.

An object of the present invention is to produce a effective detergent additive that does not have the disadvantages environmental consequences of the use of EDTA.

The document EP-A-325909 describes compositions alkaline bottle cleaning comprising agents ethoxylated nonionic surfactants blocked at the ends. Reinforcing and complexing agents may be present.

According to a first aspect of the invention, provides the use of an alkaline wash formulation that includes an additive for a bottle washing formulation according to the claim 1 and the dependent claims 2-12.

This additive, which is exempt from EDTA or from similar chelating agents, it is used with a washing formulation alkaline, more preferably a washing formulation based on caustic soda, at a concentration between 0.25 and 3%, preferably 1-2%, whereby, in the case of bottles of PET, most preferably the concentration does not exceed 1.5% with in order to minimize stress cracking. This formulation it is effective in achieving detergency, particularly against Mold pads.

Sodium gluconate offers the advantages of being commercially available and if easily soluble in both alkaline as acidic solutions, thus making possible the development of concentrated additives. In addition, sodium gluconate It will chelate both divalent and trivalent ions. As a result, In addition to facilitating the removal of mold pads, remove rust stains from the top of the bottles closed with crown cap and will prevent precipitates from forming sodium aluminate when washing bottles that carry labels of aluminum sheets Another consequence of its chelation capacity of trivalent ions is that the clays extracted from the labels old in the washroom will disperse and not precipitate over The bottles that are washed.

A wetting agent is an agent to reduce the surface tension in order to increase intimate contact between the cleaning formulation and the dirt. According to this invention, the wetting agent has the following formula general:

R 1 - (OC 2 H 4) n - (OC 3 H 8) m - OR_ {2},

in which R_ {1} = alkyl chain of length between C_ {8} and C_ {20}  \ hskip0.7cm (preferably C 10 a C_ {15}) R2 = H, (C1 to) alkyl C5) or benzyl n = 1-20 (preferably 2 a 10) m = 0-15 (preferably below 5 per biodegradability)

and preferably it is present as a component of a non-ionic mixture, which is a mixture that further comprises an antifoaming agent and a rinsing agent, in order to optimize cleaning. A preferred wetting agent it's Plurafac ™ LF 131.

Polyacrylates offer the advantage of being substantially inert, thereby limiting problems environmental factors associated with them, being easily separated by precipitation of waste water, for example, with water residual. Due to their easy solubility, they can be used at very high doses. concentrated, thereby increasing the effectiveness of the additive Detergent.

Additional preferred features of the additive according to the present invention, are found in the accompanying claims.

The additive according to the present invention is developed primarily for use in cleaning formulations in soft water areas. When desired for use in water areas hard, preferably an agent that prevents formation is added of scale, a phosphonate such as Dequest 2000 ™ or Bayhibit AM ™.

The additive can be formulated to be alkaline, acid or neutral pH, in the latter case preferably including a preservative agent, for example, formaldehyde, for prevent microorganisms from feeding on the additive and make It deteriorates.

According to a second aspect of the present invention, a procedure for cleaning bottles is provided, in particular bottles of returnable PET drinks.

This cleaning procedure is carried out below a maximum temperature of 60 ° C, above which thermal damage to PET bottles is possible, and between 50ºC and 80ºC for glass bottles.

The invention will now be described by means of following examples.

Several new PET bottles were soiled with tomato juice that had been inoculated with Aspergillus niger mold. The dirt was left in the bottles for 6 weeks, after which the molds had grown in visible colonies that were strongly attached to the surface of the PET. Cleaning tests were carried out in a bottle washer at a laboratory scale at 60 ° C, which is the maximum safe temperature for washing PET bottles. The detergent solutions were sprayed like a concentrated jet on the inside base of a bottle turned upwards at a flow rate of 4 l / min. Time was noted to remove all visible dirt. 3 bottles were cleaned for each detergent. The table below gives the total time to clean the 3 bottles.

Three reference solutions are included:

a) 1% caustic soda

b) 1% of caustic soda plus 0.5% of attached base (20% sodium gluconate + 1.2% non-ionic mixture).

c) 1% of caustic soda plus 0.3% of SU 860, in the that SU 860 is a commercially produced deputy agent based on EDTA (between 30% and 35% as EDTA Na4), and that additionally comprises sodium gluconate (<10%) and wetting agents and non-ionic defoamers (<3%).

The rest of the test solutions are made up of solution b) plus 500 mg / l of the test additive.

TABLE

Do not. Test solution Total time of washed for 3 bottles (min.) one a) 1% soda caustic > 22 two b) 1% soda caustic + 0.5% base attached 14 3 c) 1% caustic soda + 0.3% of SU 860 10 4 b) + Sokalan ™ PA 50 (polyacrylate, weight molecular 12 30,000 of BASF) 5 b) + Sokalan ™ PA 25 PN (polyacrylate, weight molecular eleven 4,000 of BASF) 6 b) + Versicol E7 (polyacrylate, molecular weight 26,000, 9 from Allied Colloids) 7 b) + Norasol ™ LMW 45 (polyacrylate, weight molecular 9 4,500 of Norso-Haars) 8 b) + extra non-ionic agent (180 mg / l) 8

The numbers 4-7 fall within the claimed range.

The tests were carried out at a dose of soda Caustic less than 1.5%, which is the limit for washing Safe PET bottles. Stress cracking tests showed that the effect of the product on the PET under tension  was lower than that of the EDTA-based product currently recommended.

Based on the previous results, it developed a formulation 9 that consisted of:

Material % Gluconate sodium 20.0 Norasol ™ LMW Four. Five 11.0 Sodium Sulphonate Cumene (40%) 15.0 Mix no ionic 4.8 Sodium hydroxide (fifty%) 2.0 Water until \ overline {100.0}

Cleaning trials showed that 1% soda Caustic + 0.2% of formulation 9 cleaned 3 bottles, which they had left aging for 12 weeks, in a cumulative time 10 minutes, while 1% of caustic soda + 0.3% of SU 860 it required 12 minutes, and 1% of caustic soda + 0.3% of a known gluconate-based adjunct agent (Stabilon Flüssig de Henkel) It required 16 minutes.

Although formulation 9 was developed to cleaning PET bottles, could be equally suitable for Clean glass bottles. In this case, it would not be subject to temperature and caustic level limitations imposed on washing of PET bottles.

Claims (13)

1. Use of an alkaline wash formulation, which It includes an additive comprising: - a polyacrylate - sodium gluconate - and a wetting agent of the general formula R 1 - (OC 2 H 4) n - (OC 3 H 8) m - OR_ {2} , in the what R_ {1} = an alkyl chain of length between C 8 and C 20, R 2 = H, (C 1 to C 5) alkyl or benzyl, n = 1-20, and m = 0-15 To wash bottles. 2. Use according to claim 1, wherein the Sodium gluconate is present in the additive in the range of 0.1 at 40% of the formulation. 3. Use according to claim 1 or 2, wherein the additive comprises a wetting agent of the general formula shown in claim 1, wherein: R_ {1} = is from C 10 to C 15,

 \ hskip0.2cm 

n = 2-10, and

 \ hskip0.2cm 

m = 0-5 4. Use according to any of the claims previous, in which the wetting agent is Plurafac ™ LF 131. 5. Additive according to any of the previous claims, wherein the wetting agent is present in a non-ionic mixture. 6. Use according to any of the claims previous, in which the polyacrylate has a molecular weight between 3,500 and 30,000. 7. Use according to claim 6, wherein the polyacrylate is present in a range between 0.1 to 20% of the formulation. 8. Use according to claim 7, wherein the polyacrylate belongs to the group consisting of, Sokalan ™ PA 25 PN, Versicol ™ E7, and Norasol ™ LMW 45. 9. Use according to any of the claims 1-8, in which the alkali is caustic soda. 10. Use according to claim 9, wherein the Caustic soda is present in the formulation in the interval between 0.25 and 3%. 11. Use according to claim 5, wherein the formulation further comprises a solubilizing agent for solubilize the nonionic mixture. 12. Use according to claim 11, wherein Solubilizing agent is sodium cumene sulfonate. 13. Procedure for washing bottles, which comprises the step of exposing the bottles to a formulation cleaner according to any of the claims 1-12, at a temperature of 60 ° C or less for PET bottles and between 50ºC and 80ºC for the bottles of glass.