JPH0374498A - Thixotropic, aqueous liquid detergent composition, its manufacture, and method for cleaning dirty tableware - Google Patents

Abstract

PURPOSE: To obtain the subject composition having a cleaning power and chemical stability by mixing layered clay, a polymer thickener, a chlorine-type bleach, and a silicate in a specified ratio.

CONSTITUTION: This composition is obtained by mixing (A) 1 to 5 wt.% (preferably 2.5 to 3.5 wt.%) layered clay having a particle diameter of about 0.001 to 1 μm, such as synthesized hectorite, (B) 0 to 5 wt.% (preferably 0.1 to 0.3 wt.%) polymer thickener, such as a crosslinked acrylic acid (salt), (C) 0.5 to 40 wt.%, (preferably 1 to 25 wt.%) builder, such as sodium polyacrylate, (D) 0.1 to 5 wt.% (preferably 0.3 to 2 wt.%) available chlorine derived from a bleach, and (E) 5 to 40 wt.% (preferably 15 to 25 wt.%) silicate provided that the weight ratio of the component (A) to the component (B), if present, is 40:1 to 5:1.

COPYRIGHT: (C)1991,JPO

Description

[Detailed description of the invention] 4 to gloss 44 Cleaning compositions for automatic dishwashers have become extremely popular.

The market for this product has expanded significantly over the past decade, as dishwashers have become increasingly popular in consumer homes and the frequency at which dishwashers are used to clean dishes has increased.

Powdered dishwashing compositions have been found to have very good cleaning power. However, powder has some disadvantages that make it difficult to use. That is, the powder may spill out of the box or spout and be deposited in undesirable locations. t
However, it is difficult to use the powder in a dishwasher in the correct dosage because the powder pours into the small measuring cup of the dishwasher very quickly. Moreover, the powder
If stored for a long time under conditions of high ambient temperature or humidity, it will turn into a cake.

These undesirable aspects of powders have led to liquid products for automatic dishwashing. Unlike powders, liquids do not splatter and cake from the container unless forced through an opening.

Liquids are also easier to dose into measuring cups, which is why automatic dishwashing liquids [゛°autodish liquids]
The cleaning product is viscous and pours more slowly than the powder, and the liquid is expelled through a much smaller opening, so the cleaning product flows into the measuring cup in a relatively small stream. Due to their characteristics, liquid products can be metered and used more easily and accurately.

Autodish liquids are also advantageous in that they dissolve quickly in cleaning liquids and can be produced in a simpler process than powders.

However, the autodish liquid itself has some problems. The main disadvantage of such liquids is that they have a tendency to undergo phase separation or syneresis. When phase separation occurs, solids suspended in the liquid, such as thickeners, builder salts, or porcelain protectants, precipitate out of the liquid. The resulting product has a transparent or translucent layer and an opaque and wet solid layer. Such phase separation seems to suggest that the product is somewhat compromised or defective, giving a negative impression to the consumer. The present invention therefore aims at producing an autodish liquid with improved phase stability.

Additionally, drawbacks exist with autodish fluids in which non-phosphate materials are used as builders.

In phosphate-based compositions, the builder is present in the composition at a level above its solubility and thus in the form of suspended solids. When water-soluble builder substances are used, the consistency of the resulting composition is not maintained in the detergent measuring cup of an automatic dishwasher.The rheology of the composition is also quite different from that of a normal liquid with phosphate as a builder. different. The present invention therefore also aims to provide a composition in which non-phosphate materials are used as builders, yet which has a rheology and consistency similar to conventional autodish fluids.

Conventional autodish liquids also have the disadvantage of losing bleach activity during product storage. Autodish liquids are usually aqueous compositions. The composition usually contains chlorine bleach to improve cleaning power. but,
The longer chlorine bleach is left in an aqueous environment, the more it breaks down.
As a result, bleach activity is lost. Therefore, the present invention
It is also an object to produce an autodish liquid composition with less chlorine bleach loss.

Ordinary autodish liquids have phosphate as a builder, which softens the washing liquid water in the dishwasher.
It also contains a phosphate compound that helps suspend dirt particles. However, despite the effectiveness of phosphate builders, significant efforts have been made to prohibit the use of phosphate compounds in household cleaning compositions. Accordingly, there has been a growing desire to produce phosphate-free compositions for use in dishwashers as well. Although significant efforts have been made to identify suitable phosphate builder substitutes, fully satisfactory phosphate-free machine dishwashing compositions have not yet been obtained, and phosphate substitutes, such as calcium or magnesium-bound It has disadvantages such as low strength, poor solid suspension properties, and incompatibility with chlorine bleach. Phosphate builder replacements are usually susceptible to chlorine bleach degradation, i.e., non-phosphate builder-containing compositions not only lose builder, but also lose a significant amount of the chlorine bleach they also contain. The disadvantage is usually that the cleaning power of compositions that are substantially free of phosphate builders is reduced. It is therefore an object of the present invention to provide an autodish liquid that is substantially phosphate-free but still has cleaning power comparable to phosphate-based compositions and chemical stability against chlorine bleach. shall be.

The composition of the present invention is an aqueous liquid cleaning composition containing a combination of clay as a thickening agent and a polymeric thickener. Combinations such as those described above not only achieve advantageous viscosities in compositions, but also improve phase stability and reduce chlorine bleach loss in aqueous environments, compared to clay or polymeric thickeners alone. Better. Moreover, the phosphate-free cleaning compositions of the present invention have highly effective cleaning power.

One specific example of the present invention is: a) layered clay with a particle size of about 0.001 to 1.0 μm
b) 0-5% polymer thickener, C> 0.5-40% builder, d) 0.1-5% available chlorine from bleach, e) 5-40% silicate. An aqueous liquid cleaning composition containing a weight ratio of clay to polymeric thickener present in the composition from 40=1 to 5:1.

In a preferred embodiment of this composition, the clay is synthetic hectorite and the polymeric thickener has a molecular weight of 500.000.
~5,000,000 crosslinked polyacrylate.

Another embodiment of the invention comprises: a) layered clay with a particle size of about 0.001 to 1.0 microns;
b) 0-5% polymer thickener; C) 0.5-40% builder; d) 0.1-5% available chlorine from bleach; e) 5-40% silicate. and substantially phosphate-free, wherein the optionally included polymeric thickener is present in the composition, the clay to thickener weight ratio is 40. :1 to 5:1. The composition may be substantially free of other thickening or stabilizing agents, such as polyvalent metal ions, long chain fatty acids, or mixtures thereof.

In the specific example above, the builder has a molecular weight of 2,
000 to 6,000, which is much smaller than polymer thickeners, but is still a polymer, polycarboxylate.

The composition of the present invention is composed of thixoLrop.
ic) and 1,000 to 50,0O in 5sec-'
It has a viscosity of Ocps.

The composition of the present invention is preferably used, for example, as an automatic dishwashing detergent.

Two further embodiments of the composition of the present invention include colorants and/or
Alternatively, it may contain an opacifying agent and a surfactant, respectively.

In one preferred embodiment, the ratio of silicate to clay in the composition is 9:1 to 2:1, preferably 7:1 to 2:
1, most preferably in an amount ratio of 5:1 to 2:1. If an optional polymeric thickener is present, the silicate to clay ratio is from 12:1 to 2:1, preferably 10:
1 to 2=1, most preferably 8:1 to 2+1.

The present invention also provides a method of imparting phase or bleach stability to chlorine-containing thixotropic cleaning compositions. The method includes incorporating into the composition a stabilizing system consisting of a specified amount of clay and a polymeric thickener having a specified relative weight ratio to each other.

The present invention also provides improved cleaning power to phosphate-free cleaning compositions by adding, in addition to the stabilizing system, the polyacrylic builders described above.

Additionally, the present invention provides a method of making a thixotropic aqueous cleaning composition. In one embodiment of this method, the clay is dispersed in water to form a slurry, heated to 40°C and stirred, then the polymeric thickener is added and then the silicate and stirred. Alternatively, the water may be heated first and then the clay added.

In another embodiment, some non-phosphate builder is added to the water before the clay to give the composition better viscosity during handling.

The first specific example of the Japanese invention is as follows: a) particle size of about 0. OO1~1. OALm layered clay 0
．． 1-5%, b) 0-5% polymer thickener, C) 0.5-40% builder, d) 0.1-10% available chlorine from bleach, e) 5-5% silicate. 40% of the clay and optionally present polymeric thickener in a weight ratio of 40:1.
5:1.

Together, the clay and polymeric thickener in the composition constitute a stabilizing system. Clay and polymeric thickeners, when both present in a given relative weight ratio to each other, provide improved product stability while reducing bleach loss in an aqueous environment.

Suitable Leh particles for use in the compositions of this invention are determined by their particle size. Thus, very fine synthetic hectorite clays are particularly preferred because their small particles are particularly useful in imparting desired properties to compositions thickened and stabilized in binary stabilization systems. This is because it is clear that "Particle size" should be understood to mean the particle size that the dry clay particles have after being warmed up. A suitable particle size for the clay used in the present invention is 0.
001 to 1.0μ, preferably 0.005 to 0.5
μLR is also preferably 0.01 to 091 μm. If the clay material listed below has a particle size larger than desired, it is also possible to crush or crush the material as a means of bringing the average particle size within the desired range.

Clays suitable for thickening systems in cleaning compositions include smectites,
It may include organophilic layered clay minerals belonging to the geological classifications of kaolin, illite, chloride, attapulgite and mixed layer clay.

Typical examples of specific clays belonging to the above classification are: 1) smectites such as montmorillonite, bentonite, pyrophyllite, hectorite, saponite, sauconite, nontronite, talc, and vaprite; 2) illites such as brabesite, muscovite, and baragonite. 3) Chlorides such as colensite, beninite, donbasite, and sootite; 4) Attapulgite such as seviolite and polygorskite.

The layered clay mineral may be naturally occurring or platform-based. Preferred clay minerals for use in the present invention are natural or platform smectites and apurgites (particularly hectorite, montmorillonite and bentonite), of which hectorite is particularly preferred.

Many of the above clays are commercially available, and a typical example of commercially available hectorite is manufactured by Laporte Industry in the UK.
Laponites of esLtd, R.T. of the United States,
VanderbilL's Veegum Pro and V
eegum F, as well as US National Lea
d Company's Baroid Divisio
Barasyms of n.

Macaloids and Propaloids.

A particularly preferred commercially available hectorite is synthetic hectorite L
aponite S%Laponite XLS, L
Among aponite RD and Laponite RDS, Laponite X is particularly preferable.
It is LS. Laponite
, 5a204.4%, LizOO, 8%, structure H2O7
, 8%, specific gravity is 3.54, and bulk density is 1.0.
It is a synthetic hectorite.

Effective levels of layered clay in compositions with stabilizing systems are from about 1 to about 5% by weight, preferably from about 2.0 to about 4.5%, most preferably from about 2.5 to about 3.5% by weight. Weight%.

The polymeric thickener of the stabilizing system may suitably be a polycarboxy polymer copolymerized with a multivinyl or multiallyl functionalized crosslinker.

Preferably, the polycarboxy polymer is copolymerized with a polyargenyl polyether of a multivalent compound; the multivalent compound should have at least 4 carbons and 3 hydroxyl groups. Such thickening agents are described in U.S. Pat. No. 2,798,053, U.S. Pat. No. 4,130,501
and co-pending U.S. Patent Application No. 202,087 filed June 2, 1988 by Elliott et al. and assigned to the present applicant. All of these documents are incorporated herein by reference. More specifically, the thickener is a water-dispersible copolymer of α-β monoolefinically unsaturated lower aliphatic carboxylic acid crosslinked with a polyether of a polyol. The polyol may be selected from oligosaccharides, reduced derivatives of oligosaccharides in which the carbonyl group is converted to an alcohol group, and pentaerythritol. The hydroxyl groups of this polyol are etherified with allyl groups, and the polyol has at least two allyl groups per molecule.

Suitable copolymers include acrylic acid and low ratios (0.71 to
1.5%) of polyallylsucrose. The molecular weight of the crosslinked polymer thickener is approximately 400.000
to 10,000,000, preferably 5
00,000 to 5,000,000, most preferably about 1,000,000 to 4,000,000.

Commercially available crosslinked polymers based on allyl sucrose modified polyacrylic acid include, for example, B, F, Goodri
Carb manufactured by ch Chemical Company
There is opo I resin. This substance is called Carbopol
941R (m, w, 1,250,000), Car
bopol 934R (++, w, 3,000,00
0) and Carbopo 1940R (Lw, 4,0
00,000), Carbopol 950R, Car
bo-pol 951R1 and Carbopol 9
Contains 54R. Most preferred is Carbopol 9
It is 34R.

The polymeric thickener in the compositions of the present invention is about 0 to about 5% by weight.
, preferably from about 0.1 to about 1% by weight, most preferably from about 0.15 to about 0.4% by weight.

For stabilized systems comprising both layered clay and polymeric thickener, the relative weight ratio of clay to thickener is from about 40:1 to about 5=1, preferably from 35:1 to 10=1, Most preferably it should be about 30:1 to 15:1.

It should be pointed out that there is no need for the additional components required in other clay and polymer-containing thickening systems to be present in the stabilizing system used in the present invention. That is, the clay and polymer systems used in the present invention do not require the presence of polyvalent ions, long chain fatty acids, or combinations thereof to thicken the composition; is considered not necessary. Indeed, when preparing the cleaning compositions of the invention containing the stabilizing system described above,
The resulting composition can be free of thickening substances other than layered clays and crosslinked polymer thickeners, such as polyvalent ions, long chain fatty acids, or combinations thereof.

The cleaning compositions of the present invention contain builder components that sequester hardness ions, namely calcium and magnesium, present in the cleaning water. If not sequestered, the cations can react with soil and surfactant molecules to form undesirable precipitates.

This deposit can remain on the surface to be cleaned and cause spotting or film staining.

The builder component of the composition can be a phosphate-containing compound. The compounds include orthophosphates, pyrophosphates and polyphosphates, as well as organophosphates. Suitable counterions include alkali metal ions, ammonium or substituted ammonium, and the like. Preferred phosphate builders are polyphosphates because they have the greatest solubility and hardness sequestering effects. Most preferred are hydrated alkali metal salts of polyphosphoric acid.

This hydrated salt crystallizes in the form of needles, whereas the unhydrated phosphate crystallizes in the form of cubes. Needle-shaped crystals do not often fuse into larger crystals.

As the unhydrated phosphate crystals coalesce, they increase the viscosity of the liquid over time. Such uncontrollable viscosity increases are preferably avoided by initially using the aqueous phase phosphate.

The cleaning compositions of the present invention can also contain non-phosphate builders in addition to or in place of phosphate builders. Non-phosphate builders may suitably be inorganic materials such as alkali metal carbonates as are known. Alternatively, the builder may be an organic material such as an alkali metal salt of citric acid or other polycarboxylic compounds.

Non-phosphate builders include Molecular Covenant t, oo.

Polycarboxy polymer molecules of ~100,000 are most preferred, with molecular weights of 2,000 to 2,000 being preferred, especially for non-phosphate builders with bleach stability, and 3,000 to 10,000. It turned out to be the most preferable. Suitable polycarboxy polymer compounds include homopolymers of acrylic acid, maleic acid, itaconic acid, etc., and copolymers of monomeric materials such as those described above. Commercially available non-phosphate builder materials include Alc.

Icospe to the Chemical Company
rse 602N (m, w, 4,500, solids 45%
), and 5okalan PA-30 (m, +s, 8,
000).

The builder compound is present in the composition in an amount of about 0.1% to about 40%, preferably 0.5% to 20%, most preferably 2% to about 10%.
exists at the level of

Assuming that the amount of polycarboxylate polymer builder required to sequester the hardness cations present in the water is stoichiometrically related to the amount of hardness cations, a hardness level of 240 pp.
m, approximately 20% polymer builder is required,
Builder levels of 0.5-20% or 2-10% run the risk of being substantially inadequate. However, even at low levels, polycarboxylate polymers have been found to exhibit sufficient builder activity to sequester hardness ions and provide acceptable cleaning. Without limiting the invention described herein in any way, Applicant:
We believe that the above-mentioned levels of builder activity obtained from low builder levels are due to a "marginal effect." The crystals do not grow as they would in the absence of the polymer, i.e.
The defective crystals remain dispersed, and each individual crystal has a different tendency to stick to surfaces, so they cannot form films or speckles on glass or other surfaces.

The cleaning compositions of the present invention, when used as automatic dishwashing formulations, typically also contain an oxidizing agent. Traditionally, sodium hypochlorite has been used as an oxidizing agent in liquid dishwashing compositions because this material is inexpensive. However, it is also possible to use other oxidizing agents.
For example, heterocyclic N-bromo and N-chloroimides such as trichlorocyanuric acid, tribromocyanuric acid, dibromocyanuric acid and dichlorocyanuric acid, and salts of the imides with water-soluble cations such as potassium and sodium. Can be used. An example of hydrated dichlorocyanuric acid is C1earo manufactured by 01in Corporation.
There is nCDB 56. The oxidizing material is present in the composition in an amount of about 0.
1-1.5% available chlorine is present so that it is produced.

Preferred compositions have 0.5-1.2% available chlorine.

Automatic dishwashing cleaning compositions based on the compositions of the invention also contain alkali metal silicates. This material is used as a cleaning agent, a source of alkalinity, a corrosion inhibitor, and a protector for the shine of ceramic tableware. Sodium silicates having a 5iCh:Ha20 ratio of about 1.0 to about 3.3, preferably about 2 to about 3.2 are particularly effective. Silicates may be used in aqueous liquid form or in solid form,
The silicates are present in an amount of about 1 to 50%, preferably about 5 to about 20%, by weight of the composition.

The amount of water present in the liquid composition of the present invention is inappropriate if it is so large that the viscosity is too low and the flow marks are too high, or so small that the viscosity is too high and the flow marks are too low. In both these cases the thixotropic properties are reduced or destroyed. Accordingly, water will normally be about 25% to 80% by weight of the composition, preferably about 45% to 80% by weight of the composition.
It is present in an amount of 75% by weight, most preferably about 55-65% by weight.

The cleaning compositions of the present invention may optionally contain one or more bleach-stable surfactants. These surfactants should have low foaming properties, since air bubbles will interfere with the cleaning operation of the dishwasher.

Claims (14)

[Claims] (1) (a) 1 to 5% by weight of layered clay with a particle size of approximately 0.001 to 1 μm; (b) 0 to 5% by weight of a polymer thickener; (c) 0.5 to 40% by weight of a builder. , (d) 0.1 to 5% by weight of available chlorine from bleach, and (e) 5 to 40% by weight of silicates, relative to the layered clay and polymeric thickener, if present. A thixotropic aqueous liquid cleaning composition having a weight ratio of 40:1 to 5:1. (2) (a) 2.5-3.5% by weight of clay, (b) 0.1-0.3% by weight of polymer thickener, (c) Sodium polyamide with a molecular weight of 3,000-6,000. 2. The method according to claim 1, comprising 1 to 25% by weight of acrylate, (d) 0.3 to 2% by weight of available chlorine derived from bleach, and (e) 15 to 25% by weight of silicate. Composition. (3) The composition according to claim 1 or 2, wherein the layered clay is synthetic hectorite. (4) The composition according to any one of claims 1 to 3, characterized in that the polymeric thickener is crosslinked polyacrylic acid or a salt thereof and has a molecular weight of 500,000 to 5,000,000. thing. (5) The ratio of clay to polymer thickener is 20:1 to 10.
The composition according to any one of claims 1 to 4, characterized in that: :1. (6) (a) about 1 to 5% by weight of layered clay with a particle size of about 0.001 to 1 μm, (b) 5 to 40% by weight of silicate, (c) 0.5 to 40% by weight of builder, and (d) Contains 0.1 to 5% by weight of available chlorine derived from bleach and is substantially free of polymeric thickeners, with a relative weight ratio of silicate to clay of 7:1 to 2: 1. A thixotropic aqueous liquid cleaning composition. 7. The composition of claim 6, wherein the silicate to clay ratio is from 9:1 to 2:1. (8) The composition according to any one of claims 1 to 7, which contains substantially no phosphate. (9) Builder has an average molecular weight of 1,000 to 10,000
The composition according to any one of claims 1 to 8, characterized in that it is a sodium salt of polyacrylic acid. 10. A composition according to any one of claims 1 to 9, characterized in that it also contains 1 to 10% by weight of a bleach-stable surfactant. (11) The composition according to claim 1, characterized in that it also contains 0.05 to 0.5% by weight of an opacifying agent. (12) A method of making a thixotropic aqueous liquid cleaning composition according to claim 1, comprising: (a) adding substantially all of the water required by the composition at room temperature or slightly below room temperature; (b) adding clay to the water in the container to form a slurry in the container; (c) heating the water to about 40°C and maintaining this elevated temperature level for about 40 minutes; (d) optionally add a polymeric thickener to the slurry and stir for approximately 30 minutes; (e) add silicate to the vessel and then mix for up to 1 hour.
(f) Add the builder to the container and then mix for up to 15 minutes.
(g) cooling the slurry in the container to a temperature lower than 30° C.; (h) adding and mixing a bleaching agent to the slurry in the container. (13) The builder is a low molecular weight polycarboxylic acid or its salt, and the builder substance is added to the water in the container in an amount of about 10% by weight or less of the total clay present in the composition, and no clay is added to the water. 13. The method according to claim 12, characterized in that the method is added during the treatment. (14) (a) preparing an aqueous solution of the composition of claim 1; (b) exposing soiled dishes to said aqueous solution being agitated in an automatic dishwasher; and (c) rinsing the dishes. How to wash dishes.