Low Temperature Low Foaming Alkaline Cleaner and Method

The present invention is concerned with a low temperature low foaming cleaner composition. In particular, the invention is concerned with utilizing alkaline materials as highly efficient cleaners useful at temperatures as low as 60.degree. F. (15.6.degree. C.).

In order to obtain a highly efficient cleaner, high detergency components, such as alkaline components, are employed. In order to have a decreased cost involved in cleaning operations in the manufacturing processes followed by industry low temperatures are used. Foaming, however, is a common problem due to the use of surfactants to increase the ability of cleaners to operate at lower temperatures. However, due to the foaming problem, anti-foaming agents have been added to allow the low temperature operation to be utilized. With the addition of the anti-foaming agents, however, poor detergency has been noted. The combination of low temperature low foaming alkaline cleaners is obtainable by virtue of the present invention.

Alkaline cleaner compositions are well known as those that contain alkali or alkaline earth metal borates, silicates, carbonates, hydroxides, phosphates and mixtures thereof. It is to be appreciated that phosphate includes all the broad class of phosphate materials, such as phosphates, pyrophosphates, tetraphosphates, and the like. Silicates include all of the usual silicates used in cleaning such as metasilicates, silicates and the like. The alkali or alkaline earth metals include such components as sodium, potassium, calcium, magnesium, barium and the like. It is to be appreciated that a cleaner composition can be improved by utilizing various mixtures and ratios of the borates, hydroxides, carbonates, phosphates, silicates and the like. For appropriate end uses, one of the phosphates may be used and not a carbonate. Conversely, silicates may be used and no phosphates used depending upon the end use of the cleaner composition.

The invention is concerned with a low temperature low foaming alkaline cleaner composition comprising:

(a) an alkaline portion containing at least 75 percent by weight (PBW) of alkaline materials selected from the group consisting of alkali or alkaline earth metal borate, silicate, carbonate, hydroxide, phosphate and mixtures thereof;

(b) an ethoxylated alkyl phenol in an amount from about 0.1 to about 15 PBW; and

(c) an ethoxylated and propoxylated alkyl phenol in an amount from about 1 to about 15 PBW;

wherein the sum of (a), (b) and (c) equals 100%.

In particular, the invention is concerned with the combination of a 1:1 ratio of ethoxylated (5 ethoxy units) octyl phenol and ethoxylated (7 ethoxy units) octyl phenol. The nonyl phenol could be used with only slight increase in foam. The compositions are useful in solid or liquid state as is further described below.

The alkaline portion (a) of the low temperature low foaming cleaner composition contains at least 75 PBW of the cleaner composition and may contain up to 90-95 PBW.

Ethoxylated alkyl phenols are used to lower the surface tension of alkaline cleaners. The alkyl phenols that are employed are nonionic surfactants. The alkyl group can be from 6 to 12 carbon atoms, preferably C.sub.8 and C.sub.9. The ethoxylated portion generally has from 4 to 18 ethoxylated units, preferably 5 to 7 units. Most preferably, the ethoxylated alkyl phenol is a combination of two alkylated phenols. Preferably, the phenol is a combination of 5 ethoxy units of an alkylated phenol and 7 ethoxy units of an alkylated phenol on a 0.5-2:1 weight ratio, preferably a 1:1 ratio. The total ethoxylated alkyl phenol that is used in solids ranges from about 0.1 to 15 PBW of the cleaner composition.

The preparation of ethoxylated and/or propoxylated alkyl phenols are well known in the trade. Condensation reactions between phenols and ethylene oxide and/or propylene oxide are conducted until the desired ethoxylation or propoxylation is obtained. It is to be appreciated that these condensation reactions result in products that have mixtures of each of the oxide components.

In order to obtain the desirable low temperature low foaming properties of the cleaner composition, it has been found most desirable that an improved nonionic alkylated phenol be used. The material that is employed is an ethoxylated and propoxylated alkyl phenol, where the number of ethoxylated units ranges from 3 to 18, while the number of propoxylated units ranges from 3 to 18, preferably 4 to 14 ethoxylated units and 8 to 18 propoxylated units. The weight ratio of the ethoxylated and propoxylated alkyl phenol ranges from about 1 to about 15% of the cleaner composition. The sum of components (a), (b) and (c) equals 100% by weight.

It is to be appreciated that other components are added to the composition depending upon the end use of the cleaner. In some cases it is found that the metal to be treated may corrode and therefore the cleaner composition may have an anti-corrosive material present therein. Any variety of anti-corrosive materials may be employed, such as amines, borates, nitrites and the like, preferably sodium nitrite.

The cleaner composition is applicable towards any of the normal metallic substrates employed in industry, such as iron, zinc, aluminum, stainless steel, brass, copper and the like substrates.

The cleaner composition is preferably used to remove a wide variety of materials as oils and soaps that are built up on the metal during manufacturing processes which manipulate the metals. Examples of such oils are paraffinic oils, sulfurized oils, chlorinated sulfonated oils and the like. The soaps are those that are well known in the trade which are used during a drawing process to prepare metallic components.

A particular advantage of the present invention is not only the low foaming properties of the composition, but also the low temperature of its operability, that is, a temperature as low as 60.degree. F. (15.6.degree. C.) for operability. While the upper limit of cleaning temperature is the boiling point of the liquid cleaner, generally the upper temperature is about 212.degree. F. (100.degree. C.).

Frequently, the low temperature low foaming alkaline cleaner composition of the present invention is supplied on a dry solid basis. The end user takes a portion of the solid and mixes it with water by stirring and sprays it onto the substrate to obtain the necessary cleaning. The amount of the solid cleaner composition that is mixed with the water ranges from about 0.1 to about 20% by weight of the total aqueous composition.

Some industries, however, desire that liquid compositions be used as cleaners rather than having to manipulate dry products. In that situation, the present invention is also concerned with an aqueous composition. When the components of the low temperature low foaming alkaline cleaner composition is to be shipped in an aqueous medium, the use of a surfactant suspending agent is employed. It has been found particularly desirable to maintain the stability of the aqueous cleaner composition that a suspending agent, e.g., a high molecular weight carboxy vinyl polymer, be employed. The suspending agent that is employed is an effective amount, preferably ranging from about 0.1 to 5 PBW, more preferably 0.2 to 1 PBW, and even more preferably 0.2 to 0.6 PBW of the aqueous cleaner composition. The suspending agent maintains all of the surfactants in the cleaner compositions together to prevent separation therefrom. The suspending agent is an acrylic acid polymeric material generally available to the trade under the name Carbopol 914 (trademark of B. F. Goodrich for a high molecular weight carboxy vinyl polymer of the anionic type). When an aqueous system is employed as a shipping medium for the alkaline cleaner, the amount of water that is used ranges from about 25 to 65% of the cleaner composition. The cleaner composition is then considered a concentrate by the user, who in turn dilutes the aqueous cleaner concentrate composition such that there would be 0.5 to 10 parts of the cleaner concentrate per 100 parts of water. The cleaner composition is then sprayed in a manner very similar to that described above relating to the dry composition.

The aqueous solutions of the present invention when supplied to the consumer as a concentrate or when in use have an alkaline pH generally greater than 10, preferably 11.5-12.5 although concentrate has higher pH, e.g., 13.

Having now described the invention in general, recited below are preferred embodiments wherein all parts are parts by weight and all temperatures are in degrees Centigrade unless otherwise indicated. In all the examples recited below, a soiled metallic substrate was sprayed with the cleaner composition at a rate of 1.5 parts cleaner per 100 parts of water with satisfactory cleaning of an oiled steel substrate. The liquid was sprayed at the pressure (gauge) and temperature indicated for about 30 seconds. Percent clean is determined visually.

A medium duty silicated cleaner with low foam properties was formulated as follows:

Oil on Steel Panel:

Sulfurized Oil: 100% clean at 90.degree. F., 5 psi

SAE-90: 95% clean at 110.degree. F., 5 psi

A non-phosphated inhibiting cleaner for operation at 80.degree.-90.degree. F. was formulated as follows:

Oil on Steel Panel:

Sulfurized Oil: 100% clean at 78.degree. F., 10 psi

SAE-90: 100% clean at 78.degree. F., 10 psi

A non-silicated inhibiting cleaner for operation at 80.degree.-90.degree. F. was formulated as described below:

Oil on Steel Panel:

SAE-90: 100% clean at 80.degree. F., 10 psi

A medium to heavy duty alkaline cleaner for operation at 80.degree.-90.degree. F. was formulated as described below:

Oil on Steel Panel:

Paraffin Oil: 100% clean at 70.degree. F., 10 psi

Sulfurized Oil: 100% clean at 80.degree. F., 10 psi

SAE-90: 100% clean at 70 F., 10 psi

The above formulation was used to clean a soiled cold rolled steel substrate at 60.degree. F. with good cleaning results.

A low temperature cleaner was formulated as follows:

A low temperature non-phosphate cleaning composition was formulated as follows:

An inhibited low temperature cleaner was formulated as follows:

The cleaning results of Examples 5-7 are that they clean equivalently to the powdered equivalent in cleaning SAE-90 oil at 80.degree. F.

Antarox LF-222 is a propylene oxide (average 13 propoxy units) capped ethoxylated nonyl phenol (trademark of GAF Corporation).

Igepal CA-520 is an octylphenoxypoly (ethyleneoxy) ethanol of a nonionic type being a liquid with an HLB index of 10.00 (trademark of GAF Corporation).

Igepal CA-620 is octylphenoxypoly (ethyleneoxy) ethanol of a nonionic type being a liquid with an HLB index of 12.00 (trademark of GAF Corporation).

Kasil #1 is potassium silicate having 8.3% K.sub.2 O; 20.8% SiO.sub.2 and weight ratio SiO.sub.2 /K.sub.2 O of 2.5 (trademark of Philadelphia Quartz Co.).