US3520815A - Process of preparing stable detergent composition - Google Patents

Description

United States Patent Clfice 3,520,815 Patented July 21, 1970 U.S. Cl. 252-99 4 Claims ABSTRACT OF THE DISCLOSURE A detergent composition is disclosed having both improved deforming agent and chlorine-release stabilities upon prolonged storage. The detergent composition, particularly suitable for use in automatic dishwashers, contains as essential ingredients 2. chlorine degradable polyethenoxy nonionic surfactant deforming agent, chlorinated trisodium phosphate, and sodium metasilicate pentahydrate.

This application for United State Letters Patent is a continuation-in-part of application Ser. No. 586,023 filed Oct. 12,1966, now abandoned.

The present invention relates to a method for preparing a new detergent composition having both improved defoaming agent and chlorine-release stabilities upon prolonged storage. The detergent composition useful in automatic dishwashers contains as essential ingredients, a

chlorine degradable polyethenoxy nonionic surfactant defoaming agent, chlorinated trisodium phosphate, and so dium metasilicate pentahydrate.

E[t is well known in the art that many detergent compositions which have a granulated consistency require special additives or processing steps to prevent composition agglomeration or caking and sticking. For example, Milenkevich et al., in U.S. Pat. No. 2,895,916, discloses a procedure for preparing detergent compositions by adding water and a water-soluble alkyl metal silicate to an anhydrous water-soluble alkyl metal condensed phosphate to substantially hydrate the phosphate before the addition of any chlorinated trisodium phosphate to the mixture. Caking and sticking of the mixture is apparently avoided by this procedure. Further, Matthaei, in U.S. Pat. No. 3,247,118, describes a highly complicated procedure for avoiding caking and sticking of a granulated detergent composition containing chlorinated trisodium phosphate. It is essential to the Matthaei process that mixing be performed of an anhydrous condensed phosphate with water and thereafter chlorinated trisodiumphosphate is added to the mixture. The mixture is subsequently dried to remove moisture prior to being packaged. Notwithstanding the fact that the order of mixing ingredients of the Matthaei procedure is opposite to the order of mixing of the present invention, the low chlorinated trisodium phosphate concentration thereof would not exhibit any significant defoaming agent instability.

It has now been found that by practice of the present invention and in contrast to the experience of the prior art, water is not required in the basic composition to prevent caking and sticking during storage.

Generally stated, the present detergent composition contains the following essential ingredients, expressed as weight percents:

Ingredient: Parts by weight Chlorine degradable polyethenoxy nonionic surfactant defoaming agent 0.1-3 Chlorinated trisodium phosphate 30-80 Sodium metasilicate pentahydrate 5-45 Soda ash 0-40 Calcium silicate O-2 Water-soluble condensed alkali metal phosphate 0-60 and sufiicient water to provide a total moisture content of from 20 to 50 weight percent. Preferably, the composition contains from 30 to 35 weight percent water.

The method of this invention requires mixing together the essential ingredients in any order, as long as the water and water-soluble condensed alkali metal phosphate are mixed in the presence of at least one other ingredient. It appears that soda ash, sodium metasilicate pentahydrate and calcium silicate either separately or in combination aid in preventing caking of the mixture.

A simple mixture of condensed phosphate, chlorine degradable polyethenoxy nonionic surfactant defoaming agent, chlorinated trisodium phosphate, sodium metasilicate pentahydrate, with or without condensed phosphates, and calcium silicate is subject to another difliculty. During storage, chlorine is released by the chlorinated trisodium phosphate and attacks the defoaming agent, degrading it, with the result that the activity of the defoaming agent and the available chlorine tend to decrease after prolonged storage.

In general, the method of this invention comprises mixing together a chlorine degradable polyethenoxy nonionic surfactant defoaming agent, chlorinated trisodium phosphate, sodium metasilicate pentahydrate, and other ingredients such as a water-soluble condensed alkali metal phosphate, if desired, with sufiicient water to provide a total moisture content of from 20 to 50 weight percent. Desirably, the moisture content is from 30 to 35 Weight percent and more desirably from about 31.5 to 32.5 weight percent. It is essential that Water and condensed phosphate be mixed together in the presence of at least one of the other ingredients, if a condensed phosphate is to be present in the composition.

The essential ingredients in the composition of this invention and their concentrations are:

Concentration, wt. percent Chlorine degradable polyethenoxy nonionic surfactant defoamin g agents found useful herein are well known. For example, these materials are disclosed in U.S. Pat. No.

3 2,674,619 and appear generally as compounds having the formula:

where y equals at least and (C H O) equals 90%, of the total weight of the compound. Additional useful defoaming agents are disclosed in U.S. Pat. No. 2,380,166 and appear generally as a mixture of a lipophilic partial ester of a long chain fatty acid and a hydrophilic polyhydroxylic organic compound, and a highly hydrophilic hydroxypolyoxyethylene ether of a lipophilic partial ester of a long chain fatty acid and a hydrophilic polyhydroxylic organic compound.

U.S. Pat. No. 2,856,434 also describes defoaming agents useful herein. This patent discloses benzyl ethers of alkylphenoxy polyethoxyethanols having the formula:

r 0 cnzormno 011206115 wherein R is an alkyl group of eight to fifteen carbon 7 atoms and n is an integer from twelve to forty. Polyoxyalkylene surfactants described in U.S. Pat. No. 2,677,700 are also usefully employed herein. These surfactants arr pear to be a cogeneric mixture of compounds having the formula:

Y(oxypropylene) EH wherein Y is a residue of an organic compound containing one active hydrogen atom capable of reacting with 1,2 propylene oxide, n is an integer, and E is a polyoxyalkylene chain wherein the oxygen/ carbon atom ratio is equal to or greater than 0.50; and E constituting 95%, by weight, of the mixture.

U.S. Pat. No. 2,673,882 also describes defoaming agents useful herein. These materials are described to be mixed polyoxyalkylene ethers of hexitols represented by the following formula:

wherein R is the residue of a hexitol; x and y represent 2 or 3 and are of different values; in and n each represents an integer above 6 and below about and the ratio of mm lies within the limits of from 3:1 to 1:3. Alkylphenoxy polyoxyethylene ethanols produced by reaction of an alkylphenol with ethylene oxide; and the oxyalkylated glycerols, produced by reaction with glycerol of a mixture of ethylene and propylene oxides are also useful defoaming agents. Yet additionally useful defoaming agents, representing a preferred group, are those having the formula:

3 e )X( 2 4 )y wherein R represents an alkyl group of 1 to about 15 carbon atoms and x and y represent a positive number from 2 to 98. Acetylenic glycol 2,4,7,9-tetramethyl-5- decyne-4,7-diol type compounds as well as ethylene oxide condensates with addition product of propylene oxide and ethylenediamine are also usefully employed herein. The composition of the latter group of addition products appears to have the general formula:

wherein x and y are positive numbers from 2 to 48.

The composition of the present invention may contain, in addition to the above nonionic surfactants, diglycol laurate, an anionic defoaming agent.

A defoaming chlorine degradable polyethenoxy nonionic surfactant defoaming agent as used herein is defined as a material which will decrease foam height at least 10 percent as measured by the Defoamer Test. In this test 0.015 grams of the agent is dissolved in 500 milliliters of water heated to 70 C. This solution is added to a Waring Blendor containing 1.0 gram of a non-fat dried milk and 1.5 grams of chlorinated trisodium phosphate, and the components are mixed for 30 seconds. The

water, non-fat dried milk, and chlorinated trisodium phosphate, alone, give a foam height of about 3.5 inches.

The composition of this invention may also contain other detergents, germicides, water softeners, insulating agents, and the like, as desired.

Suitable water-soluble condensed alkali metal phosphates include the sodium and potassium pyrophosphates, metaphosphates and pyrophosphates such as sodium tripolyphosphate, sodium hexametaphosphate, tetrasodium pyrophosphate, the corresponding potassium phosphates, and the like.

In general, the water component may be mixed with the other ingredients of the composition of this invention in any order of addition, so long as the water and the condensed phosphates, if any are to be present, are mixed in the presence of another ingredient of the final composition. The water may be added to any of the single components with the exception of the condensed phosphates or mixtures of more than one of the components.

The composition of this invention exhibits far greater stability of the chlorine-degradable defoaming agent and chlorinated trisodium phosphate upon prolonged storage. Because of the high concentration of the chlorinated trisodium phosphate in the composition of this invention, the addition of water in the stated manner was found necessary to avoid degrading the defoaming agent. No drying to remove a part of the added water is necessary to prepare the final product.

The invention is further illustrated by the following specific but non-limiting examples.

EXAMPLE I This example demonstrates the improved chlorine-degradable defoaming agent stability and available chlorine retention in the compositions of this invention.

The control or blank sample was prepared as follows: 10 parts of soda ash were placed in a mixer, and 23 parts of sodium tripolyphosphate were added. The mixture was blended for 1 minute. To the mixture was added 1 part of a defoaming compound having the general formula:

wherein R appears to be ethyl and x and y are selected such that the compound has a molecular Weight of about 1200. This defoaming compound is commercially available as the trademarked product Makon NF-12 by Stephan Chemical Co. of Chicago, Ill. The mixture was blended for one minute. Then, with blending between each addition, 15 parts of sodium metasilicate pentahydrate, 1 part of calcium silicate, and 50 parts of chlorinated trisodium phosphate were added.

Sample 1 was prepared from two batches. In one batch, 5 parts of sodium tripolyphosphate, 15 parts of sodium metasilicate pentahydrate, 50 parts of chlorinated trisodium phosphate, and 2.5 parts of water were mixed together for 2 minutes. In the second batch 10 parts of soda ash, 18 parts of sodium tripolyphosphate, and 1 part of the defoaming compound indicated were mixed for 2 minutes. The two batches were then combined and mixed for an additional two minutes. Then 1 part of calcium silicate was added, and the total formulation was mixed for an additional two minutes.

Sample 2 was prepared from 2 batches. In one batch 5 parts of sodium tripolyphosphate, 15 parts of sodium metasilicate pentahydrate, 50 parts chlorinated trisodium phosphate and 2.5 parts of water were mixed together. In a second batch 10 parts of light soda ash, 18 parts of sodium tripolyphosphate and one part of Makon NF12 previously defined were blended together for two minutes. The 2 batches were then combined and mixed for an additional 2 minutes. Then, one part of calcium silicate was added, and the total formulation was mixed for an additional 2 minutes.

Sample 3 was prepared by mixing one batch for 2 minutes 5 parts of sodium tripolyphosphate, 12.5 parts of sodium metasilicate pentahydrate, and 50 parts chlorinated trisodium phosphate. The second batch was prepared by mixing in 2 minutes 12.5 parts soda ash, 18 parts of sodium tripolyphosphate, and one part of Makon NF-12. The two batches were then combined and mixed for an additional 2 minutes. Then, one part of calcium 6 As shown in the table, the water addition is critical for obtaining improved defoaming agent stability and retention of active chlorine in the detergent compositions of this invention upon prolonged storage.

silicate was added, and the total formulation was mixed 5 EXAMPLE 2 2.? addlilctmal i d t d t th d f In this example a series of samples having the same g g g o fi i f fi g composition (except for the blank which contained no an We 3 on m y an added water) were formed, the difference between the a .3 (grage g yz peno S 0 d g 1 f samples being the manner of preparation, sequential mixth e p E i g 8 E 2 ing rather than master batching, and the order of addi- 70 Pg Q q f 3: 5 m '66 0 tion of the various components in the mixture. The quant '2 1a a t "E i g tity of each component in the samples and the abbreviacon ammg 0 a a me i mlxmg or tion for each component adopted for use in Table B were seconds, and then as soon as a definite line of demarcaas follows. tion was observed, measuring the foam height.

The active chlorine was measured as follows: A sample containing approximately 2 g. of a chlorinated detergent was weighed to the closest 0.1 mg., and transm Abb.e ferred to a 300 ml. flask containing 100 ml. of distilled imi; tiori iii Water. To the flask was added from 2-3 g. of potassium Ingredient by Table 0 iodide crystals and 10 ml. of glacial acetic acid. The sosodiummpolyphosphate 23 TPP l tion was then titrated with 0.1 N sodium thiosulfate g gg g DEX (standardized with a 0.1000 N potassium iodate solution) 851mm fliggigfigfiigfiflfiig: 15 SM until most of the yellow color of iodine was destroyed. gi ga g eg gg p p t 5% 01 1; T0 the solution was added 0.5 g. of thyodene, and the jj 25 W titration was continued until all of the blue color disappeared. The available chlorine was calculated as follows: Available chlorine, Wt. percent The order of addition of the components in each sam- N t N s O 0 03546 ple and the respective available chlorine and foam heights Na2s2o3 S 1 a2 2 3X of the samples after prolonged storage at 38 C. is given amp 6 W below in Table B.

TABLE B Sample No Blank 4 5 6 7 8 9 10 11 if ff .i SA TPP S SM SA 'IPP SM 'IPP TPP TPP DEF DEF DEF DEF OLP W DEF DEF DEF SA SA SM SM W CLP SA SM SM P 1; 53 5? 55% CLP SA T P CS CLP CLP W CLP SA SA SA OLP 1 as as CS 08 CS CS CS CS Available chlorine, wt. percent after 38 C2 storage for:

0 days 1.70 1.62 1.62 i. 7 days 1. 40 1. 42 1. 54 1.62 14 days. 1.25 1.30 1. 54 1. 4e 21 days. 1.20 1.24 1. 40 1. 51 28 days. 1. 07 1. 37 1.42 35 days .02 1. 09 1.38 1. 38 Foam height, eighths of aiti inch after 38 C. s orage:

5 4 5 5 4 4 e 5 3 913 121?" 1i 9 s 5 e 6 5 12 6 14 days 24 13 6 6 6 21 days. 22 18 e e 6 16 28 days 20 7 8 8 8 8 20 8 35 days 22 22 7 9 6 The moisture contents of the detergent mixtures were The blank and Samples 4 and 10 showed poor chlorine obtained by heating a 10 g. sample of the mixture on an stability and defoaming agent stability. The blank con- Ohaus moisture balance for 15 minutes at a temperature tained no water, and Samples 4 and 10 were formed by of about -150 C. No additional Weight loss was mixing sodium tripolyphosphate and water in the absence found after the first ten minutes of heating. 60 of any of the other ingredients. In contrast, when the The test results obtained for these samples is shown water was mixed with the condensed phosphate in the below in Table A. presence of other ingredients and in quantities sufficient TABLE A Foam height, eigliths of an inch Available chlorine Sample No. Control 1 2 3 Control 1 2 3 Storage time at 38 (3.,

days:

to provide about 31.5 to 32.5 weight percent total moisture in the final mixture, as measured with a moisture balance, a greatly improved chlorine release agent and defoaming agent stability was observed.

EXAMPLE 3 In this example, the efiFect upon the chlorine release agent stability and defoaming agent stability caused by various quantities of water in the mixture was determined. All of the samples were prepared using the following addition sequence: 10 parts of soda ash, one part of Makon NF-12, 15 parts of sodium metasilicate pentahydrate, 50 parts of chlorinated trisodium phosphate, water in varying amounts, 23 parts of sodium tripolyphosphate, and one part of calcium silicate. The chlorine release agent stability and defoaming agent stability for the samples after prolonged storage at 38 C. is shown in Table C.

TABLE Sample No 1 2 3 4 Water added, parts 0. 5 2. 0 2. 5 3. 0 Available chlorine wt. percent after storage at 38 0 for 1. 66 1. 58 1 61 1. 55 1. 33 1. 52 1 50 l. 58 28 days 1. 22 1. 45 1 42 1. 44 Foam height, eighths of an inch after 38 0. storage for:

4 4 4 4 8 6 6 i 28 days 20 6 8 As shown in Table C, the preferred quantity of water in the mixture is from 2 to 3 parts corresponding to a total moisture content in the final mixture of from 31 to 33 weight percent.

What is claimed is:

1. A process for forming a detergent composition having improved defoaming agent and chlorine-release agent stabilities consisting essentially of mixing sufiicient water to provide a total moisture content of from to 50 weight percent with the following essential ingredients, expressed as weight percents:

(A) A chlorine degradable polyethenoxy nonionic surfactant defoaming agent 0.1-3 (B) Chlorinated trisodium phosphate 30-80 (C) Sodium metasilicate pentahydrate 5-45 (D) Soda ash 0-40 (E) Calcium silicate 0-2 (F) Water-soluble condensed alkali metal phosphate 0-50 the Water and the water-soluble condensed alkali metal phosphate, if present, having been mixed in the presence of at least one other of said ingredients.

2. A process of claim 1 wherein the water is mixed with the following essential ingredients, expressed as Weight percent:

(A) A chlorine degradable polyethenoxy nonionic surfactant defoaming agent 0.5-2 (B) Chlorinated trisodium phosphate 35-60 (C) Sodium metasilicate pentahydrate 10-30 (D) Sodaash 2-30 (E) Calcium silicate 0-2 (F) Water-soluble condensed alkali metal phosphate 10-40 3. The process of claim 1 wherein sufficient water is added to provide a total moisture content of from 30 to 35 weight percent total moisture in the final product.

4. The process of claim 1 wherein sufiicient water is added to provide a total moisture content of from about 31.5 to 32.5 weight percent total moisture in the final