Process of treating laundry in laundry driers

Abstract

The novel and advantageous process of treating laundry comprises predrying the washed and rinsed laundry to a predetermined degree of dryness such as to a moisture content between 5 and 70 percent and preferably to a moisture content of about 15 percent, subjecting the predried laundry, preferably in a laundry drier, to the action of laundry treating agents, such as brighteners, antistatic, softening, aromatizing, and the like agents, preferably by spraying said agents thereon, and completing drying of the laundry. Thereby, any moldy smell of the laundry and/or its becoming electrostatically charged are eliminated and/or the properties of the finished laundry are considerably improved. Drying is preferably effected in laundry dryers of the tumbler type and the treating composition is preferably sprayed on the laundry in aerosol form.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a process of treating laundry in laundry driers and more particularly to a process of treating the laundry in such driers in order to eliminate the undesired moldy, typical laundry smell and/or electrostatic charging of the laundry.

2. Description of the Prior Art

During the last few years laundry driers, socalled tumblers, which are controlled, regulated, and operated electronically and/or in dependence on the drying time, have been marketed. In such laundry driers or tumblers the washed laundry can be dried so that, after being centrifuged in the automatic washing machine, it is ready for ironing or can be placed into the linen closets or storage rooms.

However, when drying the laundry in such driers, it frequently takes on an undesired moldy, typical laundry smell and/or it becomes electrostatically charged. Especially laundry consisting of or containing synthetic fiber material has the tendency to be electrostatically charged.

In order to overcome these disadvantages the laundry was additionally subjected, after having been washed and rinsed -- usually four to five times -- in the washing machine to a so-called softening rinsing procedure. Thereby, preferably cation active and/or non-ionogenic agents, emulsifiers, perfumes, optical brighteners or clarifying agents, deodorants, and coloring agents were added to the rinsing water. Part of said agents get on or become attached to the laundry and are supposed to prevent the above-described disadvantages on subsequently drying the laundry in the laundry drier. However, no satisfactory results could be achieved by proceeding in this manner because said agents -- most of which are readily volatile -- were separated and removed from the laundry during drying by the air current which passes through the tumbler. Thus the losses in such agents were considerable. Furthermore, rather large amounts of said agents added to the rinsing liquor, did not adhere to the laundry but went along together with the rinsing water. As a result thereof the rinsing water containing such agents represents a rather considerable burden upon sewage or waste water purification. This is highly undersirable in view of the attempts to protect the environment.

In addition thereto such softening rinsing procedure followed automatically the rinsing procedures in the washing machine. As a result thereof, the entire laundry present in the washing machine is -- by necessity -- treated although this is not always required and sometimes even not desired, for instance, with laundry which is to be starched subsequently.

Also cartridges filled with concentrated perfume solutions have been placed at a predetermined position into the air current circulating through the tumbler in order to transfer by vaporization the perfume upon the laundry. Proceeding in this manner, however, is accompanied by two rather important disadvantages. On the one hand, only readily volatile perfumes can be applied in this manner to the laundry and, on the other hand, such application of the perfume takes place during the entire drying procedure. As a result thereof a large proportion of the vaporized perfume is carried along by the air current and is carried away and thus is not absorbed by the laundry.

SUMMARY OF THE INVENTION

It is one object of the present invention to provide a simple and effective process of treating laundry in laundry driers so as to eliminate, for instance, the moldy smell of dried laundry and that it becomes electrically charged.

Another object of the present invention is to provide a simple and effective device for carrying out said process.

Other objects of the present invention and advantageous features thereof will become apparent as the description proceeds.

In principle the process according to the present invention comprises the step of applying the treating solutions or emulsions of agents for treating laundry -- as they are known per se -- in the laundry drier or tumbler after the laundry has attained a predetermined degree of dryness. When proceeding in this manner the above-described disadvantages of the known processes are avoided.

Preferably the solutions or emulsions of the laundry treating agents are sprayed upon the laundry whereby the spraying operation is automatically initiated by a timing impulse or as soon as a predetermined degree of dryness of the laundry is attained.

For this purpose there is installed in the tumbler, for instance, an aerosol can or container at any place readily accessible to the operator. Said aerosol can is connected by means of a suitable pipeline with a nozzle which is in direct connection with the inner space of the drying drum. A valve is actuated at a predetermined moment by means of an electrical or mechanical impulse so that the treating agents are sprayed into the rotating or tumbling laundry.

Thereby, it is of advantage if spraying with the treating agents takes place shortly before the laundry is completely dried. Preferably the moisture content of the laundry should amount to between about 5 percent and about 70 percent and most advantageously to about 15 percent.

The process according to the present invention has the great advantage -- in contrast to the heretofore known processes -- that the agents used for treating the laundry are directly applied in the desired concentration to the laundry without any loss of active agent. As a result thereof, the effectiveness of the treating agents is fully preserved and the disadvantages of the known processes are not encountered.

All agents can be used in the process of the present invention that are able and required to improve the quality of the laundry, such as cation-active and/or non-ionogenic agents, antistatic agents, perfumes, deodorants, optical brighteners, dyestuffs, and others.

In addition to their brightening effect, the cation-active and/or non-ionogenic agents used in the treatment of textiles according to the present invention cause formation of layers and preferably of monomolecular layers of said agents on the textile fibers and thus produce a sliding effect of the fibers with respect to each other. Said layers improve also sliding of the textile fibers on the skin of the person wearing the laundered lingerie or garment. As a result thereof, a positive feel and a pleasing fall of the textile material will be achieved and subsequent ironing will be facilitated. Furthermore, usually the layers have a pronounced effect of dissipating static electricity and the textiles can be more readily laundered. Numerous cation-active and/or non-ionogenic agents can be used for this purpose. Especially suitable agents of this type are:

a. Fatty acid polyglycol esters of the formula

R--COO--(CH.sub.2 --CH.sub.2 --O).sub.n H,

wherein R is preferably a higher saturated fatty acid such as stearic acid or palmitic acid.

b. Fatty alcohol polyglycol ethers of the formula

R--O--(C.sub.2 H.sub.4 O) H

in which R-O preferably stands for a higher saturated fatty alcohol group such as a stearyl or palmityl alcohol group.

c. Fatty acid alkanol amides of the formula

R--CO--NH--CH.sub.2 --CH.sub.2 --OH

wherein R--CO-- indicated preferably a higher saturated fatty acid group.

d. Fatty acid amide polyglycol ethers of the formula ##SPC1##

wherein R--CO is preferably a higher saturated fatty acid group.

e. Fatty amine polyglycol ethers of the formula

R--CH.sub.2 --N=[(CH.sub.2 --CH.sub.2 --O).sub.n H].sub.2

wherein R is preferably higher alkyl derived from a saturated fatty amine.

f. Fatty acid sarkosides (this agent is an anionic agent but can also be used in the claimed process) of the formula

R--CO--N(CH.sub.3)--CH.sub.2 --COONa

wherein R preferably is higher alkyl derived from a saturated fatty acid.

g. Organic phosphoric acid esters and their salts of the formula ##SPC2##

h. Salts of primary, secondary, and tertiary fatty amines of the formulas ##SPC3##

wherein R is higher alkyl.

i. Quaternary ammonium salts of the formula ##SPC4##

wherein R is higher alkyl derived from tallow which may be hydrogenated.

j. Amphoteric ammonium compounds of the formula

R -- N = (CH.sub.2 --CH.sub.2 COONa).sub.2 .

k. Cation-active imidazoline compounds of the formula ##SPC5##

Such agents serve also as fabric softeners and antistatic agents.

Cation-active and non-ionogenic agents for treating laundry are also described, for instance, by K. LINDNER "Tenside-Textilhilfsmittel-Waschrohstoffe" vol. II (1964) on pages 1610 to 1625, where numerous agents useful for carrying out the present invention are listed.

Suitable optical brightening agents are, for instance, derivatives of 4,4'-diamino stilbene-2,2'-disulfonic acid, in which the amino groups are substituted by triazinyl or other basic groups or by acyl groups, such as acetyl, phenoxy acetyl or alkoxybenzoyl groups. Ureido substituted diamino stilbene disulfonic acids are also useful for this purpose.

Derivatives of di-benzo thiophene-5,5-dioxide of the formula ##SPC6##

can also be used.

Azoles, such as monoazoles in the form of their sulfonic acids or bisazoles, such as bis-naphthotriazolyl compounds are also useful optical brighteners, likewise coumarin derivatives. Such optical brighteners are described, for instance, in Kirk-Othmer "Encyclopedia of Chemical Technology" Second Edition, volume 3, pages 737 to 749.

Especially useful quaternary ammonium compounds are, for instance, dimethyl benzyl cetyl ammonium chloride, dimethyl distearyl ammonium chloride, and the like compounds which in aqueous solution have not only a germicidal effect but also act as deodorants because they inhibit the production of malodors due to the action of micro-organisms and, therefore, are useful odor controlling agents.

Perfumes act as malodor counteracting and masking agents without involving any chemical changes. They also have a deodorizing and/or odor modifying effect. Any suitable perfume may be used, whereby, of course, the preferred perfumes are those which do not stain and do not cause discoloration of the laundry. Especially useful are the perfumes of the floral group, imparting flower odors to the laundry, as well as those of the herbal group imparting thereto the odor of hay and grass, clover, and the like. Lavender fragrances or the fragrances of citrus fruits may, of course, also be applied to the laundry.

Suitable deodorants are, for instance, phenolic polyoxymethylene derivatives, quaternary ammonium compounds, formaldehyde derivatives, 2,4,4'-trichloro-2'-hydroxy diphenyl ether, 3,4,4'-trichloro carbanilide, alkylolamides of undecylenic acid, and others.

Antistatic agents are added especially when washing synthetic fiber materials. There are a number of antistatic agents know, such as polyhydric alcohols, for instance, glycerol; amines, for instance, triethanolamine; amides, for instance, N,N-bis-(2-hydroxy ethyl) stearyl amide; polyoxy ethylene derivatives, for instance, hexadecyl ethers of polyethylene glycols; amine soaps, for instance, the soaps of stearic acid and octadecyl amine; amine salts of alkyl sulfates, for instance, the salts of guanidine and octadecyl sulfate; quaternary ammonium compounds, for instance, octadecyl trimethyl ammonium chloride; alkyl phosphates, for instance, bisdodecyl hydrogen phosphates; amine salts of alkyl phosphonic acids, for instance, the salts of triethanolamine and octadecyl phosphonic acid, and others.

An aerosol composition which has proved to be useful for carrying out the present invention may have the following composition:

10 parts to 50 parts of a liquified or compressed, non-combustible aerosol propellant agent,

0.0 parts and, if present, at least 0.5 parts to 50 parts of a cationic and/or non-ionogenic rinsing additive,

0.0 parts and, if present, at least 0.1 parts to 5 parts of a deodorant,

0.0 parts and, if present, at least 0.1 parts to 5 parts of an optical brightening agent,

0.0 parts and, if present, at least 0.1 parts to 5 parts of a perfume, and/or

0.5 parts to 80 parts of water or a suitable solvent, especially a lower alcohol or a halogenated alkane.

It may be mentioned that the preparations used for treating the partly dried laundry need not contain all the above mentioned groups of active agents. Their composition can be varied considerably; for instance, if a special softening effect is to be achieved, the predominant component of the preparation is the softening agent while the other agents may be omitted or added only in relatively small amounts. Likewise, the preparations may specifically contain a perfume or an aromatizing agent if a pronounced aromatizing effect is desired, or such agents may be omitted completely, for instance, when laundering hospital linen.

When applying the treating preparations to the laundry, satisfactory results are achieved only by a compromise between the following facts:

a. On the one hand, the treatment with the treating solution should be effected as early as possible, i.e., with laundry of a relatively high moisture content because then optimum distribution of the active agents over and throughout the laundry will be achieved due to the extended drying and thus treatment time.

b. On the other hand, the treating solution should be applied as late as possible, i.e., when the moisture content of the laundry is very low and thus its degree of dryness is high. Thereby optimum utilization of the treating agents will be achieved and, at the same time, the optimum amount of perfume will adhere to the laundry.

As has been found, satisfactory results are achieved if the treating solution is applied to the laundry at a moisture content between about 5 percent and about 70 percent and preferably at a moisture content of about 15 percent in order to meet both above mentioned requirements. Such a moisture content corresponds to a degree of dryness between 95 percent and 30 percent and preferably of 85 percent.

Instead of subjecting the laundry to a softening, brightening and the like treatment as described hereinabove, it is also possible to subject it to a starching treatment. In this case, those pieces of the laundry which are to be starched must be separated from those pieces which are not to be starched, and must be treated separately, too. Heretofore this was not possible, because the softening rinsing step took place as the last step in the washing machine so that the entire laundry had to be subjected to the treatment with the solftening or other agents, although laundry which subsequently had to be starched needed not be treated therewith.

It is, of course, also possible to use the compositions according to the present invention without a propellant and to spray them into the dryer by the action of compressed air. Preferably a solvent is then added to the composition such as, for instance, "FREON TF" i.e., 1,1,2-trichloro-1,2,2-trifluoro ethane and the like.

BRIEF DESCRIPTION OF THE DRAWING

The attached drawing illustrates a device for introducing the treating agent into the laundry drier. In said drawing

FIG. 1 illustrates a dosing device introducing an aerosol composition into the laundry drier by means of a nozzle and valve controlled by a timer.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In said FIG. 1 the aerosol can 1 is placed into the holding device 2 with an opening at its bottom through which the outlet 4 of the aerosol can 1 can be connected by means of adapter 3 to pipe 5. The adapter 3 is designed so that it opens the valve of the aerosol can 1. The electrically controlled valve 6 is provided in said pipe 5. Pipe 5 thus is under permanent pressure. Pipe 10 leads from valve 6 to nozzle 7. Valve 6 is also connected with timing device 8 which is either controlled by the moisture content of the air leaving the drier or by the moisture content of the laundry tumbling in said drier. At a predetermined moment valve 7 is actuated for a certain period of time by an impulse issued from said timing device 8 so that a predetermined amount of active treating agent is sprayed into the dryer and onto the tumbling laundry through nozzle 7. If the aerosol can 1 becomes exhausted, it can easily be replaced by a new aerosol can. The entire dosing device is attached to door 9 of the drier.

The aerosol composition in the aerosol can 1 may be composed as described hereinafter in the Examples although it is not limited thereto.

EXAMPLE 1

6 percent of dimethyl distearyl ammonium chloride,

0.5 percent of nonyl phenol polyglycol ether (with 9 moles of ethylene oxide),

1 percent of the quaternary ammonium compound designated as "BTC 776" i.e., an alkyl dimethyl benzyl ammonium chloride, of Organon of Duesseldorf, West-Germany,

1 percent of the optical brightening agent designated as "UVITEX SEB," i.e., thiophene-2,5-bisbenzoxazole of Ciba-Geigy of Basel, Switzerland,

1 percent of a perfume designated as "HERPYL 49S/72" of the firm UOP of Paris-Colombes, France, and 90.5 percent of water.

Eighty parts of said mixture are mixed with 20 parts of the propellant designated as "FRIGEN 12A" i.e., dichlorodifluoro methane of Farbwerke Hoechst, West-Germany.

This composition for the treatment of laundry is compounded by heating the dimethyl stearyl ammonium chloride and the nonyl phenol polyglycol ether to about 60.degree. C. The quaternary ammonium compound is then added thereto and the mixture is thoroughly emulsified in water of 60.degree. C. After cooling the mixture to 40.degree. C., the optical brightening agent and the perfume are admixed thereto. Thereafter, 80 parts of said mixture are then filled with 20 parts of the propellant into suitable aerosol cans.

An aerosol can with about 350 g. of said mixture is sufficient for treating an average amount of laundry (3-5 kg. of dry laundry) in a laundry drier about 20 times. The aerosol has a softening, bactericidal, and antistatic effect.

EXAMPLE 2

Composition which has an aromatizing and softening effect and, at the same time, acts as an optical brightener:

13.0 percent of dimethyl distearyl ammonium chloride,

1.5 percent of nonyl phenyl polyglycol ether,

14.9 percent of isopropanol,

0.5 percent of perfume,

0.1 percent of the optical brightener "Blankophor FBO" of Farbwerke Bayer, i.e., a derivative of 3-phenyl-7-amino carbostyril.

As propellant there is admixed thereto

70.0 percent of the propellant mixture "FRIGEN 11/12," i.e., a mixture of 37 parts of trichloro fluoro methane and 63 parts of dichloro difluoro methane of Farbwerke Hoechst, West-Germany.

EXAMPLE 3

Composition with a softening and bactericidal effect, low in perfume and not containing any brightening agent:

12.0 percent of dimethyl distearyl ammonium chloride,

1.75 percent of alkyl (C.sub.12 - C.sub.18) dimethyl benzyl ammonium chloride

1.00 percent of nonyl phenol polyglycol ether,

15.00 percent of isopropanol,

0.25 percent of perfume.

This mixture is used together with

70.0 percent of the propellant "FRIGEN 11/12."

EXAMPLE 4

Composition with a good softening and antistatic effect for natural and synthetic fibers:

9.5 percent of dimethyl distearyl ammonium chloride,

2.0 percent of a fatty amine polyglycol ether, i.e., a tallow amine (C.sub.16 - C.sub.18) polyglycol ether

2.0 percent of cetyl trimethyl ammonium chloride,

1.0 percent of dialkyl (C.sub.12 - C.sub.18) dimethyl ammonium chloride,

15.0 percent of isopropanol,

0.5 percent of perfume.

This mixture is used with 70.0 percent of the propellant "FRIGEN 11/12."

EXAMPLE 5

Composition with a satisfactory softening effect for natural and artificial fibers and an excellent bactericidal effect.

12.75 percent of a fatty acid (C.sub.16 - C.sub.18) ethanolamide,

1.50 percent of nonyl phenyl polyglycol ether,

0.25 percent of a perfume,

15.25 percent of isopropanol,

0.25 percent of "IRGASAN DP 300" (2,4,4-trichloro-2'-hydroxy diphenyl ether of the firm Ciba-Geigy, Basel, Switzerland, as bactericidal agent.

This mixture is used with 70.0 percent of the propellant "FRIGEN 11/12."

While the process according to the present invention has proved to be especially useful when applied to laundry dried in laundry tumbler driers, it can also be employed for the treatment of laundry in drying chambers or other drying apparatus.

It has been found that at least small amounts of water or solvent must be present in the treating solution or aerosol because otherwise no homogeneous solution would be formed.

Of course, many changes and variations in the composition of the treating agents to be applied to the laundry, in the apparatus used for applying them thereto, in the manner of applying them thereto, in the degree of dryness of the laundry on application of the treating agent, and the like may be made by those skilled in the art in accordance with the principles set forth herein and in the claims annexed hereto.

Claims

I claim:

1. In a process of subjecting laundry to a finishing treatment, the improvement which consists in the steps of

a. predrying the laundry to a moisture content between about 5 percent and about 70 percent subsequently to the rinsing step,

b. spraying upon the predried laundry a composition containing at least one conventional agent for treating laundry to improve its properties, and

c. completing drying.

2. The process of claim 1, in which solutions of such agents are sprayed upon the predried laundry.

3. The process of claim 1, in which emulsions of such agents are sprayed upon the predried laundry.

4. The process of claim 1, in which the laundry is predried in step (a) to a moisture content of about 15 percent.

5. The process of claim 1, in which the treating composition is sprayed automatically upon the laundry, said spraying being initiated by an impulse controlled by and dependent on the drying time.

6. The process of claim 1, in which the spraying step is automatically initiated at a predetermined degree of dryness.

7. The process of claim 1, in which the composition consists of

10 parts to 50 parts of a non-combustible aerosol propellant,

0.5 parts to 80 parts of water,

0.0 parts to 50 parts of a cationic surface active treating agent,

0.0 parts to 5 parts of a deodorant,

0.0 parts to 5 parts of an optical brightener, and 0.0 parts to 5 parts of a perfume,

at least one of said treating agents being present in said composition.

8. The process of claim 1, in which the composition consists of

10 parts to 50 parts of a non-combustible aerosol propellant,

0.5 parts to 80 parts of water,

0.0 parts to 50 parts of a non-ionogenic treating agent,

0.0 parts to 5 parts of a deodorant,

0. 0 parts to 5 parts of an optical brightener, and

0.0 parts to 5 parts of a perfume,

at least one of said treating agents being present in said composition.

9. The process of claim 7, in which at least part of the water is replaced by an organic solvent.

10. The process of claim 8, in which at least part of the water is replaced by an organic solvent.

11. In a process of subjecting laundry to a finishing treatment with at least one of the finishing agents selected from the group consisting of a cationic surface active treating agent, a non-ionogenic surface active treating agent, an antistatic agent, a perfume, a deodorant, an optical brightener, a dyestuff, a germicidal agent, a starching agent, and a softening agent, the improvement which consists in the steps of

a. predrying the washed and rinsed laundry to a moisture content between about 5 percent and about 70 percent

b. spraying upon the predried laundry a composition containing at least one of said finishing agents, and

b. completing drying of the thus treated laundry.

12. The process of claim 11, in which the rinsed laundry is predried in step (a) to a moisture content of about 15 percent.