Windshield wipers containing nonionic surfactant

Abstract

Paper towels especially towels having wet strength derived from cationic wet-strength resins are useful for wiping glass surfaces such as windshields of motor vehicles and this usefulness is significantly improved by the incorporation onto the paper towel of a non-ionic surfactant especially ethoxylates of linear secondary alcohols. Preferably the linear alkyl hydrophobe portion of a mixture of secondary alcohols having 11 to 15 carbon atoms and the hydrophylic portion is a polyethylene oxide chain randomly attached to the linear aliphatic chain and having approximately 15 ethylene oxide units.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to nonionic detergents surfactants on wet strength paper towels in particularly to ethoxylated secondary alcohols on paper towels having cationic wet strength resins.

2. Description of the Prior Art

Prior art paper towels designed for wiping purposes have been altered usually both chemically and physically to improve the wiping action. For example, wet strength chemicals (resins) have been added to the towels to retain their strength under the wet or moist conditions encountered during washing and wiping surfaces especially glass surfaces. Also chemical detergents and surfactants have been added to the paper towels to assist in the cleaning function. Most detergent surfactants can be divided into three subclasses that is anionic, cationic, and non-ionic detergents. As the division suggests, these detergents have certain chemical properties and thus are useful in certain applications because of their properties. Therefore these detergents are generally selected on the basis of their chemical nature.

In developing an acceptable wiping towel for glass surfaces and more particularly, glass surfaces of moving vehicles, the following requirements are important: the products must be of the throw-away variety, i.e., reasonably inexpensive; the detergent must foam with water on the glass to aid in removing visibility-obstructing dirt and grim, and the foam must break down within a short period after foaming. The detergent surfactant must be readily absorbable into the towel so that it can be substantially removed from the windshield during wiping. Moreover, the chemical must not leave a visible or light-defracting film obstructing the driver's visibility. Also, the film should resist condensation or fine droplet formation (i.e. fogging) of the windshield. It was previously believed that most non-ionic detergents were unsuitable because they leave a distinct layer of film on the windshield (see U.S. Pat. No. 3,354,089). The cationic detergents were eliminated because they are substantive to cellulose and relatively unavailable. Specific anionic detergents were discovered to be suitable and compatible with usual wet strength resins. See U.S. Pat. No. 3,354,089 and U.S. Pat. No. 3,335,449.

SUMMARY OF THE INVENTION

A paper sheet having wet strength and containing a ethoylated secondary alcohol non-ionic surfactant is suitable for wiping glass surfaces. The suitable nonionic ethoxylates of linear secondary alcohols are those having the following formula. ##EQU1## wherein x and y are integers each having a value from 0 to 14 and the sum of x plus y is from 10 to 14. Wet strengthened paper stock suitable for windshield wiper or toweling use is impregnated either by spraying, by size-press application, or by any other standard coating application technique with an active amount of the above-disclosed nonionic surfactant. Such a paper towel impregnated with the nonionic surfactant when used with moisture to wipe glass surfaces exhibit moderate sudsing to facilitate cleaning of the glass surface and wipes clean without leaving a light-defracting film, that is no haziness is left on the glass surface.

DETAIL DESCRIPTION OF THE INVENTION

The one class of nonionic detergents surfactants discovered to be suitable for use on paper windshield wipers is ethoxylated linear secondary alcohols of the following general formula: ##EQU2## wherein x and y are integers each having a value of from 0 to 14 and the sum of x plus y is from 10 to 14.

Wet-strength resin containing paper stock (cellulosic sheet material) is suitable as the base sheet for practicing this invention. Typical wet strength resins which are employed in making such paper stock are urea-formaldehyde, polyureaformaldehyde, melamine-formaldehyde, glyoxalacrylamide and similar known wet strength resins for papermaking. The specific wet strength resin employed is not critical to the practice of this invention since the nonionic detergent surfactant is compatible with conventional wet-strength resins. The nonionic surfactant can be applied to the paper either before or after the application of the wet strength resin to the paper and either before or after the curing of the wet strength resin. Furthermore, formed wet strength paper products can be rewet with a solution of the nonionic surfactant to impart an activating amount of the surfactant to the paper.

It has been found that the present non-ionic detergent surfactant when applied to wet-strengthen paper cleans glass surfaces and does not leave a visible film upon the glass surface while it loosens dirt by easily foaming up in small quantities of water without producing excessive amounts of suds. The non-ionic detergent surfactants can be sprayed onto paper products under usual production line conditions without causing significant eye irritation to the workers in the evirons of the spraying activity.

An active amount of a nonionic detergent surfactant of the present invention on paper towels depends upon the contemplated end use of the towel especially the type and amount of soil that may be encountered on the glass surface. Usually from about 0.01 to about 2.0% of the surfactant based upon the weight of the dry wet-strengthen paper stock is suitable with from about 0.5 to about 0.75% preferred.

The nonionic detergent surfactants used in the present invention are produced by ethoxylating a mixture of linear secondary alcohols containing from 11 carbon atoms to 15 carbons atoms with a hydrophylic moiety containing about 15 ethylene oxide groups. Such ethoxylated secondary alcohols comprise a mixture of compounds of the above general formula wherein n is from 11 to 15. Such detergent surfactants are available commercially under the tradename TERGITOL 15 S 15.

The following examples are illustrative and further describe this invention. Included are examples employing a representative sampling of other non-ionic surfactants which demonstrate the surprising functionality of only one non-ionic detergent surfactant namely those of the above general formula which function satisfactorily as a detergent surfactant for windshield wipers. Obviously the functionality of these specific non-ionic detergents surfactant employed in this invention could not be predicted on a basis of their being a member of the class of non-ionic surfactants in view of the demostrated inoperability of representative members of the class of nonionic detergent surfactants shown in the following examples and table and in view of the negative teachings in U.S. Pat. No. 3,354,089 in column 2, lines 7 to 11.

EXAMPLE I

Detergents surfactants listed in Table I were each sprayed in a regular pattern onto a clean windshield that had been previously washed and then rinsed with distilled water. An ordinary commercially available paper towel having some wet strength but having no detergent or surfactant was then used to wipe the area of the windshields that had been sprayed with the detergent surfactant being tested. During moderate handwiping of the windshield with the paper towel, the sudsing characteristics of the test solution were observed. The moderate wiping of the windshield in a regular pattern was continued for approximately one minute thereby duplicating the usual effort of a service station attendant cleaning a motor vehicle windshield. The first observation during initial wiping was whether any sudsing developed. The quantity and duration of the sudsing was observed and those which gave a large quantity of suds which could not be substantially removed during the one minute wiping action were rated as no good as were those which gave no suds. Those surfactants that sudsed and whose suds were essentially removed during the wiping test were rated as having good sudsing characteristics.

After the one minute of wiping a moist film remained on the windshield which was allowed to dry. The windshield was then visually observed with an unaided eye for any detectable haze or visible film residue. These observations were recorded as either leaving a visible residue (yes) or not leaving a visible residue (no). The above test was performed for all of the detergent surfactants listed in Table I and from the results reported it is obvious that the non-ionic detergent surfactant employed in the present invention has unique properties not attributable to the general class of non-ionic detergents surfactants even the closely related detergent surfactants sold under the trade name TERGITOL 15 S.

Igepal is a series of non-ionic surfactants available from GAF Corporation. Igepal CO-630 and Igepal CO-880 are nonylphenoxpoly (ethyleneoxy) ethanols having 9 and 30 moles of ethylene oxide in their respective molecular structure. Igepal RC 520 is Dodecylphenoxy (ethyleneoxy) ethanol having 6 moles of ethylene oxide in its molecular structure. Igepal DM 430, DM 710 and DM 880 are Dialkylphenoxypoly (ethyleneoxy) ethanol having 9, 10-11 and 30 moles of ethylene oxide in their respective molecular structure.

TERGITOL 15-S is a series of non-ionic sufactants available from Union Carbide and are ethoxylates of secondary linear alcohols of the formula: ##EQU3## wherein x and y are integers each having a value of from 0 to 14, x plus y is from 10 to 14 and n is 3 for TERGITOL 15 S 3, 5 for 15 S5, 7 for 15S7, 9 for 15S9, 12 for 15 S12 and 15 for 15 S15.

Pluronic is a series of non-ionic surfactants available from Wyandotte Chemical Company formed by the condensation of propylene oxide with propylene glycol and have the general formula: ##EQU4## The characteristics of the specific Pluronic surfactant in Table I are listed in Table II.

TABLE I ______________________________________ SUDSING VISIBLE SURFACTANT CHARACTERISTICS FILM ______________________________________ Polyethoxylethyl- Good Yes aliphatic Aliphatic polyester " Yes IGEPAL CO-630 " Yes IGEPAL CO-880 " Yes IGEPAL RC-520 No good Yes IGEPAL DM 430 Good Yes IGEPAL DM 710 " Yes IGEPAL DM 880 " Yes Octylphenoxypolyethoxy " Yes ethanol TERGITOL 15S3 " Yes TERGITOL 15S5 " Yes TERGITOL 15S7 " Yes TERGITOL 15S9 " Yes TERGITOL 15S12 " Yes TERGITOL 15S15 " No PLURONIC L-62DAP " Yes PLURONIC L-35 " Yes PLURONIC L-44 " Yes PLURONIC L-64 " Yes PLURONIC F-87 " Yes PLURONIC F-88 " Yes PLURONIC F-108 No good Yes PLURONIC F-127 Good Yes PLURONIC P-75 " Yes PLURONIC P-103 " Yes ______________________________________

TABLE II ______________________________________ MOLECULAR % POLY SURFACTANT WEIGHT %POLY(ETHYLENEOXY)GROUP ______________________________________ Pluronic L-62DAP 1750 20 Pluronic L-35 950 30 Pluronic L-44 1200 40 Pluronic L-64 1750 40 Pluronic F-87 2250 70 Pluronic F-88 2250 80 Pluronic F-108 3250 80 Pluronic F-127 4000 70 Pluronic P-75 2050 50 Pluronic P-103 3250 30 ______________________________________

Claims

What is claimed:

1. A wiper for glass surfaces consisting essentially of a wet-strengthened paper sheet containing an active amount of a nonionic detergent surfactant of the following general formula: ##EQU5## wherein x and y are integers each having a value of from 0 to 14 and the sum of x plus y is from 10 to 14.

2. The paper sheet of claim 1 wherein the activating amount of detergent surfactant is from about 0.01 to about 2.0%, based upon the dry weight of the paper.

3. A wiper for glass surfaces consisting essentially of wet-strengtened paper sheet containing an active amount of a non-ionic detergent surfactant wherein the non-ionic detergent surfactant is an ethoxylated secondary alcohol produced by ethoxylating a mixture of linear secondary alcohols containing from 11 carbon atoms to 15 carbon atoms with a hydrophylic moiety containing 15 ethylene oxide groups.