Abstract:
A flexible, form-fitting glove having improved water and chemical permeation resistance and a method of manufacture. The glove is multi-layered and formed utilizing a standard dip line.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims priority and the benefit of the filing date of U.S. Provisional Patent Application Ser. No. 61/363,871, filed on Jul. 13, 2010, which is herein incorporated by reference. 
     
    
     FIELD 
       [0002]    The present application pertains to water-resistant and chemical-resistant gloves. More particularly, the present application relates to flexible, sensitive, water-resistant and chemical-resistant gloves made by the use of a dip-line process. 
       BACKGROUND 
       [0003]    Although there are many types of chemical-resistant gloves available, most suffer the disadvantage of being uncomfortable to the wearer due to the presence of stiff, inflexible materials. 
         [0004]    Historically, in order to obtain the necessary chemical and water resistance, various membranes impervious to certain chemical agents and water were laminated or heat-sealed together to produce a glove. These gloves were typically insensitive and stiff, which made hand movement difficult for the wearer. 
         [0005]    Therefore, there exists a need for a water-resistant and chemical-resistant glove that is flexible and comfortable and that is made by a dip line process. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  illustrates a glove that can be formed according to the present application; and 
           [0007]      FIG. 2  is a depiction of an exemplary cross-section of a portion of the glove of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0008]    While embodiments of this application can take many different forms, specific embodiments thereof are shown in the drawings and will be described herein in detail with the understanding that the present disclosure is to be considered as an exemplification of the principles of the application, as well as the best mode of practicing same, and is not intended to limit the application to the specific embodiment illustrated. 
         [0009]    The present application relates to a skin-covering, which has improved comfort and also improved resistance to water and chemical permeation. The present application includes a method of forming such a skin-covering. The skin-covering can be a five-fingered glove, but it also can be a mitten having only a thumb or a mitten having any combination of fingers present from zero to five. (See  FIG. 1 ) Such skin-covering is not limited to a glove or mitten, and can comprise an apron, coat, hat, scarf, sock or shoe. 
         [0010]    The chemical-resistant nature of the glove results from the presence of a multi-layer composition of at least two substantially water-proof layers and a chemical-resistant layer. The substantially water-proof layer is comprised of a mixture of polyurethane and nitrile, although generally it can be made of any material that imparts a substantially water-proof character to the glove, such as polyethylene, nitrile, polyurethane, chloroprene latex, natural latex, butyl latex, fluoric latex, and mixtures thereof. The chemical-resistant layer is comprised of polyvinyl alcohol (PVA), although any material that imparts a chemical-resistant nature to the glove is useful. 
         [0011]    Optionally, the glove also comprises a donnable layer, which lies next to the skin. In terms of orientation, the PVA layer is sandwiched between two substantially water-proof layers, preferably comprised of a mixture of polyurethane and nitrile. The layer of the polyurethane and nitrile mixture also provides chemical resistance. 
         [0012]    The PVA layer provides chemical permeation resistance. It is well-known that a broad range of chemicals such as organic solvents, plasticizers, pesticides and detergents cannot readily permeate PVA. U.S. Pat. Nos. 4,902,558 and 5,059,477, and U.S. application Ser. Nos. 12/862,311; 61/363,871; and 61/393,712, each assigned to Honeywell, which are hereby incorporated by reference, discuss the advantages of having a PVA layer in a chemical-resistant glove. These patents explain that water will tend to swell and plasticize the PVA layer. Therefore, the PVA layer should be protected on both top and bottom from the presence of water. Accordingly, if the PVA layer is next to a donnable layer, the donnable layer must be substantially water-proof. Suitable donnable layers include those of synthetic fiber, natural fiber, chloroprene latex, natural latex, butyl latex, fluoric latex, polyurethane, polyethylene and mixtures thereof. The donnable layer can be cotton, polyurethane or latex rubber. A substantially water-proof fabric material is also contemplated. 
         [0013]    It is to be understood that there is no set limitation as to the number of layers that the glove can have so long as the glove is comfortable and flexible enough for its intended use. There is also no limitation as to the presence of duplicate layers. 
         [0014]    One embodiment of the glove ( 10 ) comprises multiple layers, including at least one outer layer of a mixture of polyurethane and nitrile ( 12 ), enclosing and protecting one adjacent layer of PVA ( 14 ), which is directly adjacent to one/two polyurethane and nitrile mixture layers ( 16 - 18 ) for a grand total of three to five layers. (See  FIG. 2 ) 
         [0015]    Layer  20  is the donnable layer, which when worn is adjacent to the skin of the wearer and is optional. There are no restrictions as to the arrangement of the layers except that the PVA layer preferably is protected from moisture. Also, the thickness of the layers ranges from about 0.1 mm to about 1 mm for both the polyurethane and nitrile mixture layer and the PVA layer. The glove can contain about 1 to 70 weight percent polyvinyl alcohol and 1 to 70 weight percent polyurethane and nitrile mixture. The thickness of the donnable layer is in the range of about 0 mm to about 6 mm thick, or about 0 to 50 weight percent. 
         [0016]    In another embodiment, the polyvinyl alcohol layer ( 14 ) is in the range of about 1 to 70 weight percent and the polyurethane and nitrile mixture layer ( 12 ) is in the range of about 1 to 70 weight percent, and the polyurethane and nitrile mixture layer ( 16 - 18 ) is in the range of about 1 to 70 weight percent. 
         [0017]    The present application also contemplates a method of forming a water-resistant and chemical-resistant glove. The method can also encompass the addition of one or more additives wherein the additives comprise an adhesive, a colorant, an anti-microbial agent, a fiber, a fragrance or mixtures thereof. 
         [0018]    The method of forming a water-resistant and chemical-resistant glove comprises optionally placing a donnable layer (i.e., liner) on a hand-shaped former, optionally placing a coagulant on the hand-shaped former, then dipping the hand-shaped former into a polyurethane and nitrile mixture so that a continuous layer of the mixture is deposited on the former and removing the former from the mixture; dipping the former into an aqueous solution of polyvinyl alcohol so that a continuous layer of polyvinyl alcohol is deposited on the former and removing the former from the polyvinyl alcohol solution; dipping the former into a polyurethane and nitrile mixture so that a continuous layer of the mixture is deposited on the former and removing the former from the mixture. The glove can then be stripped from the former. The paired dipping and removing steps can be independently repeated multiple times to form multiple layers, as desired. A donnable layer (i.e., liner) can optionally be placed on the glove as the final step in addition to or instead of the first step. 
       EXAMPLE 1 
       [0019]    A chemical and mechanical resistant glove was made the process below. A porcelain former was cleaned and dried. The former was then dipped into a calcium nitrate coagulant solution. It remained in this solution for about 15 seconds. The former was then withdrawn from the solution and allowed to dry at room temperature. Next, the coated former was dipped into a mixture of polyurethane and nitrile, also having color pigments dispersed therein. The dwelling period was about 30 seconds. The former was then withdrawn and dried for about 14 minutes. Next the former was dipped into a polyvinyl alcohol solution. The dwell period was about one minute. The former was then removed from this solution, allowed to dry for about 17 minutes at about 65° C., then cooled at room temperature for about 8 minutes. Next, the coated former was dipped twice into a polyurethane and nitrile mixture. The dwell time was 0 seconds. Each dipping had a drying time of 4 minutes at 65° C. Next, cotton flock was put on. The glove was dried and stripped from the former. 
         [0020]    From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the application. It is to be understood that no limitation with respect to the specific article and/or method illustrated herein is intended or should be inferred. It is, of course, intended to cover by the appended claims all such modifications as fall within the scope of the claims.