NO823442L - DISHWASHER AND RINSEWARE FOR DISHWASHERS. - Google Patents

Description

The invention relates to an improvement in washing and rinsing agents for 'dishwashers'.

In machine dishwashing processes - two products are usually used, i.e. a detergent for use in the main ash cycle. and a rinse aid preparation for use in the rinse cycle. Both products usually contain a detergent-active material.

Since both products are used on the objects that are to be cleaned or rinsed by showering the washing or rinsing bath

containing these products, on them, which implies the use '

of a pump, the development of too much foam in this connection is a serious problem. Too much foam can cause too much noise, can damage the heating coil in the dishwasher, can lead to improper functioning of the pump and can reduce the overall efficiency of the dishwashing process. Consequently, only low-foam detergent active materials are usually used in; washing and rinsing agents for machine use. Even so, far too much foam can be developed, e.g. of the dirt that is removed from the objects to be cleaned, if no further precautions are taken. rules, such as the use of foam suppressants. This foam formation can cause the pressure in the pump such as the washing bath or

the rinsing water is sprayed on the objects with, in order for them to be cleaned, will fall, which causes the above-mentioned disadvantages.

v

It is therefore an object of the present invention to provide a washing and rinsing agent for machine use which, when used in a washing or rinsing operation, prevents the pump pressure from falling to a particular extent. . '. It has now been found that this purpose can be achieved by incorporation

in a washing or rinsing agent for machine use a small, effective amount of a special group of polymers. The washing or rinsing agent for machine use, where the special group of polymers is included, is of the usual type and composition, as the washing active material contains a non-ionic detergent, preferably a low-foaming one.

In its broadest aspect, the invention therefore relates to a washing and rinsing agent for machine use which comprises a non-ionic detergent, and this is characterized by the fact that a small, effective amount of a special group.of polymers.-The special group-of-polymers'consists of polyelectrolytes which.contain cationic charges, either permanently "or.at the use-pH value. They-have a cationic charge, to--■ carbon atom in the backbone ratio of from 0.03 to 0.5. They may contain additional neutral or anionic groups, with a ratio of anionic to cationic material as high as 3:1. They have a molecular weight in the range of 5 x. 10 3 to 5 x 10 '5 .'

' The special group of polymers consists of three types of polymers, . i.e. s .. such as are based on quaternized diethylaminoethyl methacrylate such as are based on dimethyldialkylammonium halide, and quaternized polysaccharides.

To' the first class belongs as a typical example a' copolymer of N-vinylpyrrolidone and quaternized diethylaminoethyl 1-methacrylate with molecular weight 10<5>.

To the second class belong as typical examples poly-. (dimethyldiallyla• mm■ bnium chloride) with a molecular weight of 10 5, and poly-' (dimethyldiallylairarium chloride-acrylamide) with a molecular weight of

.2.5 x 105 . to 5 x 10 and having a mole percent ratio of dimethyldiallylammonium chloride to acrylamide varying from 20:80 to 80:2.0. To this second class also belong 1,5-dimethyl-1,5-diazoundecamethylene/polymethobromide with molecular weight 5 x 10 3 io:4.. , To the third class belong 2-hydroxypropyltrimethyl-ammonium chloride ethers of hydroxyethyl cellulose with molecular weight . of .10<5>- 2.5 x IO<5>. Typical are commercially available polymers belonging to ■ the above classes', "Gafquat" 734 from Gaf • Corp. ; "Merquat" 550 from Chemviron, Brussels, Belgium; "Polybrene" from Aldrich Chem. Co-., Milwaukee, Wisc.','USA; "Polymer" JR 125 and "Polymer" JR 40.0 from.. .Union. Carbide, etc.

The polymers according to the invention are used in the washing or rinsing agent for dishwashers in an amount of 0.1 - 10%, preferably 0.2 - 1% by weight.

The rest of the mixture consists of the usual ingredients, which are present in washing or rinsing agents for machine use.

■Thus, the machine detergent usually comprises from 0.1 to 10% by weight of a non-ionic detergent, preferably a low-foaming one. This is a well-known class of non-ionic detergents, and examples of such are well-described in

the book "Nonionic Surfactants". by M. ■ Schick. Furthermore.. it comprises 1 - 8.0% by weight of one or more building salts, . f. e.g. alkali-metal-ortho--, -pyro-, -tripol<y-,>-hexametaphos.phater, .. alkali- ■ metal citrates, alkali metal carbonates, alkali metal carboxymethyloxysuccirate, alkali metal nitrile triacetate, zeolites, etc.

In addition, it contains 1 - 80% of an alkali metal silicate,

.1 - 50% of an oxygen or chlorine bleach, and it may also contain, as . evventuelle ..ingredients , perfume, germicides, . corrosion inhibitors, enzymes, bleach precursors, reducing agents, clay species, etc. Puf f are salts, e.g.: borates, can'also be included!

A fabric softener usually also comprises 1 60%, preferably 10 - 35%, by weight of a non-ionic detergent, preferably a low-foaming one, and further any ingredients, e.g. solvents, (un) organic acids, preservatives, perfumes, dyes, hydrotropes, enzymes, germicides, all. in the usual quantities..

It has been found in this respect that it is of specific use if the rinse aid also contains a small amount, i.e. 0.1% by weight of an anionic detergent. The advantages of the present invention thereby increase significantly in a rinsing agent. ■ The anionic detergent can be of any well-known type, including fatty acid soaps. Typical examples are

■ alkylarylsulfonates, alkanesulfonates, olefinsulfonates, alkyl sulfates, alkyl ether sulfates, etc.

Preferred anionic detergents are the alkali metal salts of straight-chain C₂Q-C₂₂-alkylbenzene sulfonates and alkali metal salts of C₂₂-C₂₂-alkyl ether sulfates containing 1-10. moles of alkylene oxide. Alkyl ether carboxylates are also suitable.

The products according to the invention can be made in any suitable physical form, e.g. powders, granules, tablets, liquids

6.s.v. <:>For dishwasher products, the granular form is usually produced, while the rinse aid is usually in liquid form.

In the latter case, the various ingredients in the rinse aid can of course. the rinse water is also added..

The invention must be in it. the following is illustrated by means of examples.

Examples A-F- In the following examples A-F, a normal washing process was carried out in a commercial household dishwasher. In the main wash, 30 g of a common commercial detergent was used, and at the beginning of the last rinse cycle, 2 ml of a liquid cloud lleh j.elpegent with the following composition:

The tests were carried out with this rinsing aid as well as with this mixture which. either an anionic detergent had been added, a polymer or both. The anionic detergent was sodium dodecylbenzenesulfonate and the polymer was "Gafquat" 7 34, a copolymer of N-vinylpyrrolidone and quaternized diethylaminoethyl methacrylate with a molecular weight of 105. ■ Number of rotas ions - per my. for the lower shower arm in the dishwasher was counted at different temperatures. A decrease in the number indicates a drop in pump pressure; if the number of rotations remains constant; the pump pressure remains constant. The following results were obtained. Example-. A ■■

Example B

' • Example ;C '. ■'• •• ''.-'■ Example D ,:Example E ..

Example F

Example G-Glass items were washed in a commercial dishwasher using , in the main wash,. 35 g of the following main washing product:

This was repeated, with the same mixture as before, with 0.3% of "Gafquat" 734 added. The appearance of the glass glass stands.

with regard to the presence of stains on them after drying was then assessed according to. following grading scale:

1 = no spots

2 = 1-5 3 6-10 A = 11-20 "

5 more than 20 spots.

After one wash, the following results were obtained:

.'-. without "Gafquat" 734: 3.1

with " " : 2,3

After four washes':

...without "Gadquat". 734 : 4.5

with - " i : 1.0

A'rinse cycle with one basic product according to

the examples A - F, compared'with this base product- which- was

. added .10% "Gafquat" 734, gave. following results:

one rinse cycle

without "Gafquat"- 734': 1.6

-with-- ' " " : 1.0. four'skylie cycles

without "Gafquat" 734.: 2 .5

with, " " 1.0.

Example H

Eh'dishwasher operation.was carried out in a commercial . dishwasher using the same main detergent as

in example G in a concentration of 3 g per litres.

Comparison was made in an identical manner, but now by using the same hbwood detergent, to which 0.5% of "Gafquat" 734 had been added.

The number of rotations per minute of the lower shower arm was counted at different temperatures and the following results were obtained:

Rotation speed for shower arm

Claims (7)

1. -. Detergent or rinse aid for dishwashers, comprising a non-ionic detergent, characterized in that it contains 0.1 10% by weight of polyelectrolytes containing cationic charges and having a ratio between cationic charge and carbon atom in the backbone of 0.03 0.5 and a molecular weight. in the .range from 5 x 10 3 to -5- x 10 5-.''...' 2. Washing or rinsing agent as specified in claim 1, characterized in that the polyelectrolytes further contain neutral or anionic groups, with a ratio between anionic and cationic groups of no more. than 3:1. 3.. Detergent or fabric softener as stated in claim 1 or 2", characterized in that it contains 0.2 - 1% by weight of the <p> oil electrolytes. 4. Detergent or rinse aid as specified in any of the preceding claims, . characterized in that the polyelectrolytes are based on quaternized diethylaminoethyl methacrylate, diethyldialkylammonium halide or quaternized polysaccharide. 5. Detergent for dishwashers according to any of the preceding claims, characterized by the fact that it also includes: (I) - 0.1 - 10% by weight of a non-ionic detergent, (II) 1 - .80% by weight of a builder's total, (III) 180% by weight of an alkali metal silicate, (.IV) 1 '> 50% by weight of a bleaching agent. 6.. Rinse aid as specified in any of claims 1-4, characterized in that it also comprises 1 - 60%, preferably 10-35%, by weight, of a non-ionic detergent. . 7. Rinse aid as specified in claim 6, characterized in that it also comprises 0.1 - by weight of an anionic detergent. •■ <8> .' Detergent or rinse aid as set forth in any one of the preceding claims, characterized in that the polyelectrolyte is a copolymer of N-vinylpyrrolidone and. quaternized . diethylaminoethyl methacrylate.