Abstract:
A cap device for providing warmth to the head of a person including an outer cap having a water impervious outer surface and sized to fit over the hair of a person, a liner located inside the outer cap, the liner being sized to contact the hair of a person, and a heat source including a crystalline compound capable of exothermic reaction with water. The preferred heat source is calcined calcium oxide and a powdered zeolite in a ratio of from about 14 to 20 for calcium oxide and from about 7 to 10 for powdered zeolite.

Description:
BACKGROUND 
       [0001]    This invention relates to a cap that can be worn in the shower or other places where the user wished to keep her or his hair from becoming wet. More particularly, the invention relates to shower cap in which an exothermic reaction contained within the cap generates sufficient heat to warm a cleaner and conditioner in the cap to cleanse and condition the users&#39; hair. 
         [0002]    Caps that are worn in the shower to keep one&#39;s hair dry are not new. Some caps may be made of synthetic materials that are water impervious and may be used in the shower, as a protection from rain, or as a bathing cap for swimming in a pool or other body of water. The cap may be decorated to give added visual appeal. 
         [0003]    Shower caps have been modified to include additional features. U.S. Pat. No. 5,987,967 discloses a shower cap with a pouch for long hair. U.S. Pat. No. 5,455,970 discloses a shower cap using an elastic band to maintain the positioning of the cap. 
         [0004]    In some instances, it is desirable to apply heat to one&#39;s hair. U.S. Pat. No. 4,061,898 discloses a shower cap that includes electric heating elements to facilitate drying the user&#39;s hair. U.S. Pat. No. 6,425,403 describes a shower cap which may be used with a hand-held, hot-air blower or hair drier. U.S. Pat. No. 5,773,802 discloses a shower cap with multiple layers, one of which is intended to absorb heat from a microwave device and retain sufficient heat to warm the head or hair of the user. The heat is retained by a dielectric material. 
         [0005]    U.S. Pat. No. 6,918,138 discloses a single or dual chamber plastic ampoule or like structure that contains a supercooled liquid that will exotherm when crystallized to generate heat. Once crushed or broken the chamber releases the active ingredient, such as sodium carbonate, though other exotherms may be employed. By breaking the ampoule and then placing the cap on the head, the cap will be warm enough to allow use of the rinse-free solution which is described in that patent. The major drawback of using a supercooled liquid is that the amount of liquid used is relatively small (to generate just enough and not dangerously high heat) and does not easily contact the entire inside of the cap. At best the user has to wait for it to conduct to the other portions of the cap. Also, the heat is generated and cooling begins right away. 
         [0006]    Accordingly, it would be a great advantage if a heater for a shower cap could be [provided that generated heat over a large part of the interior of the cap. 
         [0007]    Another advantage would be if the heat would continue to be generated for a longer period of time, to allow the user to shower as well as shampoo. 
         [0008]    Other advantages will appear hereinafter. 
       SUMMARY 
       [0009]    The present invention includes a shower cap or other piece of apparel that is worn to protect the hair or head from water, such as when taking a shower, to eliminate the need to dry wet hair or to preserve a hair styling that has been previously done to the hair. The cap includes a liner. Also operably connected to the device is a heat generating material that is placed in the cap, the liner or the package for the cap. 
         [0010]    The preferred material is any of the crystalline materials that can be ground or otherwise reduced in size and that produce an exothermic reaction when contacted with water. Calcium oxide and water form the preferred exothermic heat generating material. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a perspective view of the device of this invention in use. 
           [0012]      FIG. 2  is a perspective view of several devices of this invention in a package. 
           [0013]      FIG. 3  is a bottom view of the device of this invention. 
           [0014]      FIG. 4  is a section view of the device taken along line  4 - 4  of  FIG. 3 . 
           [0015]      FIG. 5  is a perspective view of another embodiment of this invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    For the purpose of this invention, the term cap is defined as any of the water impervious caps well known for use in commercial and consumer products. These caps are available in a variety of shapes, sizes, colors and may have designs or images printed or molded thereon. One such cap  11  is shown in  FIG. 1  for purposes of illustration in position on a person  13  using the device.  FIG. 2  illustrates a plurality of caps  11  in package  14 . Cap  11 , as is conventional in the industry, includes a liner  15 , seen in  FIG. 3 . The liner  15  contacts the person&#39;s head and often serves to prevent contact by the person with the harder outer surface of cap  11 . 
         [0017]    The present invention provides a source of exothermic heat that is generated when a heat generating chemical comes into contact with an activating agent. In the prior noted U.S. Pat. No. 6,918,138, an ampoule holding a supercooled liquid is used as a heat source, and the heat is generated when a small crystalline portion of the liquid is introduced, such as by breaking a membrane or seal. 
         [0018]    The previously identified drawbacks that supercooled liquids have, namely of localized heat and a risk of premature activation are solved by the present invention. Specifically, the heating element comprises a chemical in crystalline form that has an exothermic reaction when contacted by an activating liquid. Because each crystal is separately exothermic, the material can be spread throughout the entire 
         [0019]    In accordance with the invention, the heating element may be placed inside the cap, or it may be placed in the package so that the activation of the heating element warms the appropriate part of the cap prior to putting it on. In a preferred embodiment, the heating element is in the form of small granules or crystals  17 , seen in  FIG. 4 , that are embedded on one side of liner  15 , which is porous in this embodiment. The user  13  adds water to the liner  15  to begin the exothermic reaction of crystals  17 , then puts on the shower cap as the temperature rises to a predetermined level that is comfortable. 
         [0020]    In another embodiment shown in  FIG. 5 , crystals  17  are kept in a pouch  19  that is of a size and shape to hold the predetermined number of crystals  17  or other heat producing material in an interior pocket  21 . Pouch  19  includes a seal  25  that can be broken, ruptured or otherwise opened to allow water to reach the crystals  17  inside pouch  19 . 
         [0021]    Pouch  19  can be incorporated into cap  11  as seen in  FIG. 3 , or pouch  19  can be inside package  14 , in  FIG. 2 , so that the activation takes place before cap  11  is removed. When the package is used to hold the heat source, an additional feature may be employed. In  FIG. 2 , one preferred packaging element is shown. Cap  11  includes a temperature indicator  37  that advances in color as the temperature increases in order to inform the user of the degree of exotherm. In  FIG. 2 , the temperature indicator  37  is printed in the form of a trademark lettering to advertise the product, but a separate thermometer scale could also be employed. When the indicator  37  shows the temperature for use has been reached, the cap  11  is put on as needed. These temperature indicating labels  37  have in inbuilt adhesive that can be attached to the outside label to indicate and record the temperature. When a desired temperature is reached, or if needed, is exceeded, the label color will change to show the number of temperature increments that have been reached or exceeded. The indicator has a permanent recording function so that the maximum temperature reached is always recorded. Such labels are available commercially. Technical Industrials Inc. manufactures and sells such products, which have the name Temperature Recording Labels in the industry. 
         [0022]    The preferred heat generating material is a crystal that, when free from moisture, is stable for up to three to five years or more, and which react when moisture is present to generate heat. The preferred crystal is made from a crystalline mixture of calcium oxide. Calcium oxide is commercially available from a number of sources, one of which being Calcium Oxide Fisher Scientific S79946. For efficient integration of this component into the fabric, the calcium oxide is ground into small particles or crystals and a sieve is used to insure uniform particle size. 
         [0023]    In the most preferred mixture of the heat generating material is a mixture of calcium oxide with a zeolite powder. More than 150 zeolite types have been synthesized and 48 naturally occurring zeolites are known. They are basically hydrated alumino-silicate minerals with an “open” structure that can accommodate a wide variety of positive ions, such as Na+, K+, Ca 2 +, Mg 2 + and others. These positive ions are rather loosely held and can readily be exchanged for others in a contact solution. Some of the more common mineral zeolites are: analcime, chabazite, heulandite, natrolite, phillipsite, and stilbite. An example mineral formula is: Na 2 Al 2 Si 3 O 10 -16H 2 O. 
         [0024]    Preferred is a ratio of calcium oxide to powdered zeolite of from about 14 to 20 for calcium oxide and from about 7 to 10 for powdered zeolite. Most preferred is a ratio of calcium oxide to powdered zeolite is 17:8.5. 
         [0025]    The heat generation material most preferred, using the above components includes a calcined calcium oxide. This material is available as a small article size, with a diameter less than about 0.2 mm, and as a particle of somewhere between 0.2 and 0.8 mm. Larger particles are ground and smaller ones sieved, and the calcium oxide is then calcined. It has been found to be effective to calcine for at least 60 to 120 minutes, and preferably about 90 minutes, at temperatures above 500° C., and most preferably at about 550° C. for that period of time. The calcined calcium oxide is, of course, desiccated to prevent any contamination by moisture. Laboratory grade citric acid and powdered zeolite are mixed with the calcium oxide in moisture free conditions, in an appropriate reaction ratio to provide the exothermic reaction upon contact by the activating agent water. 
         [0026]    In a preferred embodiment, the heat generation material also includes a small quantity of polyalkyl glycol such as polyethylene glycol or similar materials which are used to coat the calcium oxide prior to initiating the exothermic reaction. This small coating, of 1% to 7% polyethylene glycol by weight in the total composition slows down the reaction with water to prolong the heat for over two hours. A preferred weight percent of polyethylene glycol is from 3% to 4%. Tests have been made that kept a container of one liter of water at a temperature of 140° F. to 165° F. for more than two hours. While this is a long time for a shower cap to remain hot, extending the reaction time at least for as long as needed to complete whatever other personal hygiene practices being performed is of considerable value. 
         [0027]    Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.