HUE026648T2 - Machine cleaning of plastic parts - Google Patents

Abstract

Use of a surfactant free rinsing agent comprising at least one polymer, cationic dissociable groups or a combination of cationic and anionic dissociable groups, for avoiding or reducing stress cracking in plastic parts, during its cleaning, is claimed. An independent claim is also included for mechanical cleaning of plastic parts, comprising (a) cleaning the plastic parts, and (b) rinsing the plastic parts surfactant free rinsing agent to prevent or reduce stress cracking of the plastic parts.

Description

Machine cleaning of plastic paris f0001|Tîïë invention relates to: the use of a rinse aid in the machine cleaning of plastic pacts, and also a method Ihr machine cleaning; of plastic parts, 100021 The machine cleaning of plastic parts is obviously known from prior use, ; Examples of items which are composed either entirely or partly of plastic and ore typically cleaned by machine are feadd, mfer ahd, in the food sector fe.g. crockery), in the medicinal product sector (e.g. surgical instruments) and in the laboratory sector (e,g. experimental animal: cages). The demand on the plastic parts in the context of machine cleaning can lead to the formation of Stress cracks in the plastic. The stress crack formation results in a significantly reduced service life of the pi as lie parts. 10003) Against this background, the object of the invention is to improve the machine cleaning: of plastic parts, f000H| This object is achieved by the features of tbc independent claims. Advantageous embodiments of the invention are disclosed in the dependent claims. 10005) The .invention is based on the surprising discovery that, a surfactant-lfee rinse aid, comprising at least one polymer having cationic dissociable groups or a combinaison of cationic and anionic dissociable groups, firstly achieves a good I drying effect on plastic parts and secondly prevents or at least reduces stress crack, formation on these plastic parts. J0000J The discovery proceeds fern the fact ihat stress crack formaion on plastic parts is promoted through contact of the plastic surface with the surfactants typically present in rinse aids and by the effects of elevated temperatures, The plastic parts may he exposed to the latter in the context of machine cleaning, for example, in beat drying and/or in the course of a possible subsequent thermal sterilization. |000T| Firstly, some terms used in the context of the invention: will be elucidated, |9li8| f'feg terra machine cleaning refers to the cleaning of itéras proceedmi automatically, preferably in a. dishwasher, wherein no human intervention is required daring the course of the eleanrag, 1rs the context of the invention, the term dishwasher Includes any dishwasher known is the prior ant which is suitable for cleaningflasie parts, partieulariy dishwashers which can he Used industrially or in the household and also special washing machines, mm Machine cleaning of items generally includes at least one cleaning step and at least one rinsing step. In the cleaning step, cleaning solution is applied to the items to dissolve the adhering; dirt, lie rinsing step serves: to rinse off residues of the cleaning agents potentially remaining on the items and to improve the inai drying process, The rinsing step, therefore, is generally the last step in the context of machine cleaning in which the Itéras are rinsed with liquid,

Időiéi in the context of the invention, the term rinse aid refers to a composition, which is used in the machine cleaning of items in dishwashers, for improving the final drying process. pllll lie rinse aid used according to the invention is snrföoianí-íree, he, it contains no surfactants, Surfactants are compounds which reduce surface tension;, ie, amphiphilic compounds having at least one hydrophobic and one hydrophilic part in the moleenle. lathe context of the invention, the term surfactant refers to the group consisting of anionic surfactants, cationic surfactants, amphoteric surfactants, nochersic surfactants and block copolymers (particularly composed of ethylene oxide and propylene oxide units). To illustrate these surfactant classes, reference is made to Rcmipp Chemieiexikon, |#h edition, Georg Thieme Verlag, keyword “surfactants”. ptifl The rinse aid used according to the invention comprises at least one polymer having cationic: dissociable groups: or a; combination of cationic and anionic dissociable groups, Maoromolecular compounds built op from low molecular weight monomer units are designated as polymers. By way of example, reference: is made to Korapp Chemielexikon, lö* edition, Georg Thieme Verlag, keyword ^polymers”, |őill| lonieaiy dissociable groups dissociate in sufficiently polar solvents (e,g< water) into inns and counterions. Accordingly, the at least one polymer in the raise aid diluted rmê$ fer use m aqueous solution Is préséit m least partially in ionic fern. Im the context of the invention, It Is soBMeuf if the at least one polymer has cstlpnfe dissociable groups. The at feast rate polymer, however, preferably m m ampbolyiie polymer, he. It has both cationic mû anionic dissociable groups, PS14| By way of preference, the at least one polymer may comprise at feast one monomer unit having at least one cationic dissociable group and/or comprise at least one monomer unit having at least one anionic dissociable group. The at least one polymer gartieolarly preferably comprises at least one monomer unit having at least one quaternary ammonium function and/or at least one monomer unit having at least one carboxyl function. |§015§ The at least one polymer preferably has an average mofeeolar weight greater than 1Ö 0ÖÖ, preferably greater than S§ 000:,: more preferably greater than 10# 000 and/or less than 1 000 000, preferably less than 500 000.

The at least one polymer i s ad vantageously a copolymer based on acrylate or methacrylate, it Is preferable that the monomer units of the copolymer comprise at least one quaternary ammonium compound andfef N-IsoprOpylacrylamide and/or 2-acrylamidO"2-methyl-l'-propanesaiphonic acid, wherein the quaternary ammonium compound. Éieíhacryiamidöpropylírimeihyiammoninm chloride Is preferred, 10§!?] : Cationic and ampholytic polymers, such as ate used In the eoutext of the inventions, are known to those skilled in the art, llefefenee is made, fer exarnpie, to: BBT ?67 őM fel, whihh descrihes m ampholyife polymer based on acrylate or methacrylate, which comprises as monomer units a quaternary ammonium compound (e.g. methaeryiamidopropyltBmethylammoninm chloride), N~ isopropylacryiamide and optionally 2-;aorylamido»2«methyhl~propanesoiphonie add. Polymers of this kind are commercially available. P#1S| The surfactant-tree: rinse aid used according to the invention may comprise more than one polymer haying: cationic dissociable groups or a combination of cationic and anionic dissociable groups. The surfactant-free rinse aid preferably comprises two polymers having cationic dissociable groups or a combination of cationic and anionie dtssociabie groups. mn The suriactanMree rinse aid used according to the invention preferably has a proportion of polymers havi ng cationic dissoci able groups or a combination of cationic and anionic dissociable groups of at least 0.00 ! % by weight, peferably at least 0,01% by weight, more preferably at feast 0Y!% by weight, more preferably ál least !% by weight, more preferably at least 2% by weight, particularly preferably at least 3% by weight and/or at most 40% by weight, pteferabiy at most 3()% by weight, more preferably at most 20% by weight, more preferably atmest 10% by weight, particularly preferably at most 5% by weight, f®#20] The snrfèetânt-ffee rinse aid used according to the Invention may comprise further ingredients. The surfactant-tree rinse aid may comprise, for example, at least one acid for adjusting the pH and/or as chelating; agent, 1'he at least one acid may be an organic acid, preferably an α-hydroxyearboxylic acid such as citric acid, tartaric acid, matie acid, lactic acid nie, Particular preference: is: given to citric aeid. The snrfacfant-feee rinse ill preferably comprises; 43 to: 30% by weight acid. The sorfactant-ffee rinse aid particularly preferably comprises 5 to 20% by weight acid. It la advantageous: if the surfactant-tree rinse aid additionally comprises at least one polyear boxylate, preferably a polyacrylate, particularly preferably a copolymer of acrylic acid with 2,5·· turandione. The list of possible ingredients is not exhaustive. In particular, the solvent present in the rinse aid used according to the invention is generally water, preferably fully demineralhed water. ftlEtJ The surfactant-free rinse aid used according to the Invention, diluted ready for use in aqueous solution at a temperature of 20%.', advantageously has a surface1 tension of » |# mN/m, preferably > bd gÄm as measdfed using the ring detachment method äoeosdlngio DeNoüy), |0f22J The sumetant-iree rinse aid is preferably used in accordance with the invention at a temperature of the rinse water of 65°C to 9S°€, more preferably 80°C to 9ÍHC, particularly preferably at 85eC. I0023J Preferred dosages of a rinse aid concentrate in water may be 0.5 - :2 ml/!, for example,: ca, I mML The inveoiloh further relates to a method for machine cleaning of plastic parts eompnsing the steps of: a. éleimül, the jdastic parts; b. rinsíng the plastic paris; wherein a snrfaetant-&amp;ee ribs® aid la accordance with the invention described above is used in step b) for preventing or reducing stress creek formation on the plastic parts. |8$Μ] The list of method steps is not exhaustive. I« particular, the method may indude two or mere dealing: steps máim optionally one or more pre-rinsing or Intermediate rinsing steps. As already described above, however, rinsing step b} is generally the last step in the content of machine cleaning In which the plastic parts are rinsed with lipuid, A drying step is generally provided after the rinsing step, preferably drying with hot air. Alternatively or in addition, the plastic parts may he subjected to sterilization, preferably thermal sterilization. The thermal sterilization is particularly preferably a steam sterilization. The steam sterilisation is advantageously carried oat at temperatures of 121 - 134°C, preferably at a temperature of 13d°€. |®02$] The features of 'the method according to the invention have already been illustrated above in the context of the use according to the invention. 10826] In the cleaning process, the cleaning in step aj Is preferably carried out at StFC to $5ÖC,. preferably at S!Ö:C io 7CPÜ, and particularly preferably at 60*0 andfor the rinsing In step b) is carried out at 6'5°C to 95°€:! preferably at 8ΟΛ0 to .9020, particularly preferably at: liPC. ; f0827| The rinse aid used according to the invention And also the method Cab he used in this connection with any type of plastic parts which are accessible to machine cleaning. For example, the invention can be used in the cleaning of plastic parts in the medicinal product sector, food sector and laboratory sector. In particular, the rinse aid used according to the invention and also the method are I used in the machine cleaning of plaitlc parts which are composed of polysniphone, polyphenylsnlphone, polyetherimide, polyphenylene oxide, ABi |acrylonitriio-bnfadiene>'Styrenc) plastics and polycarbonate plasties. These plasties are particularly vulnerable to stress cracks. |Í02S] Working examples of the invention are described below by means of examples. The figures show:

Fig> 1 and 2; Drying results of the invention and a comparison;

Fig, 3 and 4; Results of the stress oracle formation test.

Example 1: [0029! Three rinse aids vs hieb may be used according to the invention are prepared according to the immolations below. The amounts of the starting materials to fee used are stated in % by weight.

Example 2: fi@3§! Expérimentai animal cages composed of polyphenylsidphone were cleaned in a washing maciimé «sing the rinse aid from Example LI according to the following programme: cleaning at 40°C with neodisher LahoCkan FLA (alkaline detergent, obtainable from Dr, Weigert), dosage 4 mi/i, duration. 3 min ~ rinsing át §5's€ with the rinse aid from Example 1.,. dosage ! ml/l, dyraikm 30 s drying with hot air at 115°C, duration 2 min, [§§31| A very good drying result was achieved m the plastic animal cages which was improved compared to rinsing with (felly demineralized} water only. Fig, i shows the drying results $shte*«(I aeeofdmg to the mvemion. Fig:, % Û* comparison 0« timing with (felly deI»ÂfÎ2èci| water only. Very lew drops rsm&amp;mod m the surface ($ drops er less da 1¾¾ top surface) In the inventive example, while in the comparison the drying was slgniricamly worse (more than 100 drops on the top sar&amp;ee), Even on omitting the final drying step, very good drying of the cages was still achie ved.

Example 3: !§032J Varions experimental animal cages or parts of experimental animal cages composed of polysulphone, poiyphenylsulphone, polyetherimkk and polycarbonate were treated in a simulated rinsing step with 1 rnl/l of a rinse aid according to each of Examples 1.1: to 13 in hot water it S5*0. The cages or cage parts were then dried with hot air and subsequently steam stcrifod at 134°C fer 10 minutes in an autoclave, if cycles were carried out. No stress crack formations were evident fsee Fig. 3)..

Comparative example; f$i33J ÄS: in Example % but using a conventional rinse aid based on non-ionic surfectaopy Stress crack formations were seen on the plastic parts (see Fig. 4),

Claims (5)

TREATMENT OF PERSONAL PATIENTS 1, The use of a surfactant-free bonding material comprising at least one polymer having cationic dissociating groups or a combination of cationic and anionically dissociable groups is a plastic machine component in the salt, the plastic parts. to prevent or reduce cracks. 2, according to claim 1! The surfactant-free rinse-release material is lubricated with the at least one polymer and ion-dissociable groups. 3, according to Clause 1 or 2! A tenside-free rinse aid application, wherein the at least one polymer comprises at least one monomer unit having at least one cationic dissociating group and / or contains at least one monomer strength of at least one anionically clis-cleavable group, 4, A surfactant-free rinse application according to claim 3, characterized in that the at least one polymer comprises at least one monomer unit having at least one εememyl ammonium moiety and / or at least one monomer unit having at least one carboxyl group. &Amp; Ä 1-4. The surfactant-free rinse aid of any one of claims 1 to 3, wherein the at least one polymer is an acrylate or rheniacrylate-based copolymer. &Amp; The surfactant-free batch material time according to claim 5, wherein the copolymer comprises at least one quaternary ammonium compound as monomer units and / or N-propyl acrylamide and / or 2-3-chloran-2-ylmethyl-2-propane sulfonic acid, both. preferably the quaternary ammonium compound is methane amide propyl (methylammonium Yum) chloride. T, 1-8. A surfactant-free clay-like clay formulation as claimed in any one of claims 1 to 4, wherein the proportion of polymers having cationic dissociating groups or combinations of cationic and anionic dlsoylating groups in the curing agent is at least 0.001 wt%, preferably at least 0.01 wt%. preferably at least 0.1% by weight, preferably at least 1% by weight, and preferably at least 2% by weight, particularly preferably at least 3% by weight, and preferably at least 40% by weight, preferably up to 30% by weight, and preferably up to 20% by weight and preferably with a weight of not more than 1 and more preferably not more than 5% by weight. § 1-7 Tensile-free material for use according to one of the claims; wherein the at least one polymer has an average molecular weight of greater than 10000, preferably greater than 50000, more preferably greater than 10, and / or less than 10000, preferably less than 500,000. application, soaked lyricate, as the tensile free leachate, when ready for use in an aqueous solution, exhibits a surface tension of> 50 rnN / m, preferably> 60 mWm at a temperature of 2 ° C. 1 &amp; The tensile-free batch material according to one of claims 1 to 9, characterized by a soaked liquid, is the plastic parts of the polystyrene, polyphenylsulfone, polyether-lime, polyphenylene oxide, ABS (acrylonitrile-Suiadian-Styrene) and polycarbonate plastics -; are composed of plastics selected from the group of intestinal \ t 11, 1-10. The tensile-free material of the tensile-free material according to any one of claims 1 to 4, wherein said agent is a tensile-free material. Characteristically, the tensile free cavity material contains at least one acid, wherein the at least one acid is preferably an organic acid, and preferably is a fatty acid, particularly preferably citric acid 12, The tensile free baking agent according to claim 11, characterized in that the tensile-free rinse aid is Containing from 0.5 to 30% by weight, preferably from 5 to 20% by weight of acid, II. Tensile-free rinse aid according to one of claims 1 to 4, characterized in that the surfactant-free rinse also contains a polar-bicarbonate. 14, A machine for machine cleaning of plastic parts, comprising the following steps: a) cleaning of art parts:; head on bfelMse of mliny ag parts; contemplating that, in step (b), in the case of the plastic parts to prevent or reduce the formation of stress cracks, one of claims 1-13 is used. A surfactant-free application of a surfactant according to any one of claims 1 to 3. If the method according to claim 14, wherein the step of purification in step a) is carried out at SÖ-ÖSX-m, preferably §S ~ 7? C and particularly preferably at 6 ;; In step (b), the reaction is carried out at <RTI ID = 0.0> Ss-1 </RTI> C, preferably BÖ-90eC, and particularly preferably 8S. and / or the plastic parts are furthermore considered to be thermal sterilization, wherein the thermal sterilization is preferably a gauze sterilization, wherein the steam sterilization is preferably carried out at a temperature of 121 to 134 ° C, particularly preferably at 134 ° C.