Abstract:
This invention relates to a dispersions of polymeric colorants having poly(oxyalkylene) moieties mixed with unsubstituted sorbitan monooleate alone or ethoxylated dodecanol admixed with unsubstituted sorbitan monooleate. Such colorant dispersions are easy to handle and are effectively introduced into wax media, thereby providing significant improvements over other dyestuffs, pigments, and colorants.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation-in-part of co-pending application of U.S. patent application Ser. No. 09/110,722, now abandoned, filed on Jul. 7, 1998, of Michael O. Hunt et al. for Emulsified Poly(oxyalkylenated) Colorants for Wax Compositions. This application is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to a dispersion of polymeric colorants having poly(oxyalkylene) moieties mixed with unsubstituted sorbitan monooleate alone or ethoxylated dodecanol admixed with unsubstituted sorbitan monooleate. Such colorant dispersions are easy to handle and are effectively introduced into wax media, thereby providing significant improvements over other dyestuffs, pigments, and colorants. 
     BACKGROUND OF THE PRIOR ART 
     Poly(oxyalkylene) polymeric colorants have been utilized to permanently color myriad substrates, including thermoplastic resins, such as U.S. Pat. No. 4,284,729, to Cross et al., U.S. Pat. No. 4,507,407, to Kluger et al., and U.S. Pat. No. 4,751,254, to Kluger et al.; polyurethane foams, such as U.S. Pat. No. 4,846,846, to Rekers et al.; aqueous and non-aqueous liquids, such as U.S. Pat. No. 4,871,371, to Harris; and have been used as fugitive tints for textiles and threads, such as U.S. Pat. No. 4,167,510, to Brendle. Such colorants provide effective and stable colorations to such surfaces, are easily handled, and exhibit low degrees of staining due to their high solubility in water. 
     It has proven very difficult, however, to incorporate such beneficially performing colorants into wax compositions, particularly within candles, crayons, and other similar large-scale wax articles. Such colorants alone do not thoroughly disperse within waxes and therefore produce displeasing, non-homogeneous color effects. Nowhere within the prior art is there a teaching or fair suggestion as to how such problems can be remedied. As a result, there still exists a need for providing the benefits of polyoxyalkylenated polymeric colorants within wax compositions. 
     OBJECTS OF THE INVENTION 
     Therefore, an object of the invention is to provide a polyoxyalkylenated colorant composition which effectively, thoroughly, and homogeneously colors waxes. Another object of the invention is to provide an easily handled emulsified polyoxyalkylenated colorant composition for introduction within wax formulations. Additionally, it is an object of this invention to provide an emulsified polyoxyalkylenated wax colorant composition which performs at the optimum coloring level within such media. Furthermore, it is a further object of the invention to provide a method for effectively, thoroughly, and homogeneously coloring wax formulations. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Accordingly, the present invention is a colored wax composition comprising 
     a wax; 
     a polyoxyalkylenated colorant defined by the Formula (I) 
     
         R{A-[(alkyleneoxy constituent).sub.n H].sub.m }.sub.x      (I) 
    
      wherein 
     R is an organic chromophore; 
     A is a linking moiety in said chromophore selected from the group consisting of N, O, S, or CO 2  ; 
     Alkyleneoxy constituent contains from 2 to 4 carbon atoms; 
     n is an integer of from 2 to about 100; 
     m is 1 when A is O, S, or CO 2 , and m is 2 when A is N; 
     x is an integer of from 1 to about 5; and 
     a surfactant selected from the group consisting of unsubstituted sorbitan monooleate and an admixture of unsubstituted sorbitan monooleate and ethoxylated dodecanol. 
     Additionally, a method for coloring a wax composition is provided comprising the sequential steps of 
     (a) providing a solution of molten wax; 
     (b) providing a colorant emulsion comprising 
     a colorant defined by Formula (I) 
     
         R{A[-alkyleneoxy constituent).sub.n H].sub.m}.sub.x        (I) 
    
      wherein 
     R is an organic chromophore; 
     A is a linking moiety in said chromophore selected from the group consisting of N, O, S, or CO 2  ; 
     Alkyleneoxy constituent contains from 2 to 4 carbon atoms; 
     n is an integer of from 2 to about 100; 
     m is 1 when A is O, S, or CO 2 , and m is 2 when A is N; 
     x is an integer of from 1 to about 5; and 
     a surfactant formulation selected from the group consisting of unsubstituted sorbitan monooleate and sorbitan monooleate admixed with ethoxylated dodecanol; 
     (c) introducing said emulsion into said molten wax solution to produce a colored wax composition; 
     (d) pouring said colored wax composition into a mold; and 
     (e) allowing sufficient time for said colored wax composition to cool within said mold. 
     The colorants are generally the same as those disclosed within the prior patents listed above. The organic chromophore (R) is, more specifically, one or more of the following types of compounds: azo, diazo, disazo, trisazo, diphenylmethane, triphenylmethane, xanthane, nitro, nitroso, acridine, methine, indamine, thiazole, oxazine, or anthraquinone. Preferably, R is one or more of nitro, triphenylmethane, methine, or thiazole based compounds. Group A is present on group R and is utilized to attach the polyoxyalkylene constituent to the organic chromophore. Nitrogen is the preferred linking moiety. The polyoxyalkylene group is generally a combination of ethylene oxide and propylene oxide monomers. Preferably propylene oxide is present in the major amount, and most preferably the entire polyoxyalkylene constituent is propylene oxide. The preferred number of moles of polyoxyalkylene constituent per alcohol (i.e., hydrogen-capped) chain is from 2 to 15 (n would therefore preferably be from 4 to 30), more preferably from 4 to 10 (n would most preferably be from 8 to 20). Also, preferably two such polyoxyalkylene alcohol chains are present on each polymeric colorant compound (x, above, is preferably 2). The colorants utilized within the present invention are generally liquid at ambient conditions of temperature and pressure. However, if they are not liquid under such conditions they are still generally dispersable within the specific emulsifiers and thus, ultimately within the wax formulations in order to produce the inventive colored wax compositions. 
     Particularly preferred colorants, and thus merely examples of the polyoxyalkylene polymeric colorant of this invention, include the following: 
     
                       TABLE 1______________________________________Preferred Poly(oxyalkylenated) Colorants  Ex. #   Chromophore  Moles EO                          Moles PO                                  Group A______________________________________1     Triphenylmethane              10        10      N  2          Anthraquinone         4         2         N  3          Benzothiazole         8        10        N  4          Methine               7        15        N  5          Thiazo               10       14        N  6          Bisazo               16       20        N______________________________________ 
    
     The term wax is intended to encompass any wax or wax-like substance in which the utilized polyoxyalkylenated polymeric colorants alone are substantially insoluble. Waxes are generally defined as saturated fatty (high molecular weight) hydrocarbons. More specific types of such waxes include mineral waxes, such as paraffin, montan, ozokerite, microcrystalline, earth, and the like; animal waxes, such as beeswax, waspwax, Chinesewax (insectwax), and the like; vegetable waxes, such as carnauba, sugarcane wax, candelilla, flax wax, and the like; and 
     synthetic waxes, such as Fischer-Tropsch wax, polyethylene wax, and the like. Wax compositions can be molded into different articles such as candles and crayons (with the addition of sufficient amounts of suitable plasticizers, such as stearic acid), ear plugs, and the like. 
     The specific surfactants have proven to be the only emulsifiers which provide the necessary degree of dispersability (and thus solubility) for the polyoxyalkylenated polymeric colorants within the target wax formulations. It has thus been realized that unsubstituted sorbitan monooleate (that is, there are no extra moieties present on the surfactant, such as alkoxylates, alkyls, alkylenes, and any other groups), available from Imperial Chemical Industries under the tradename Span 80®, performs, as the sole emulsifying agent, at a level well above any other type of individual surfactant. Furthermore, this unsubstituted species in combination with ethoxylated dodecanol (4 EO), such as the surfactant sold under the tradename Synfac™ DG, available from Milliken &amp; Company, provides the same beneficial level of performance as the sorbitan monooleate alone. Preferably, the emulsifier is present in amounts of from about 50 to about 99 parts (out of one hundred) of the entire colorant emulsion (thus the colorant is present in amounts of from about 1 to about 50 parts). Preferably, the surfactant is present in amounts from about 70 to about 95 parts per hundred, more preferably from about 80 to about 92, and most preferably from about 81 to about 91. Within the two surfactant formulation, generally the sorbitan monooleate is present in major amounts. Preferably the sorbitan monooleate is present in amounts from about 51 to about 98 parts per hundred (of the total colorant composition) while the ethoxylated dodecanol is present in amounts from about 1 to about 49 parts; more preferably the sorbitan is present in amounts from about 74 to about 90 parts and the dodecanol from about 1 to about 18 parts. Furthermore, the colorant is present in amounts from about 3 to about 19 parts per hundred. 
     The colorant dispersion (emulsion) is generally added in an amount of from about 0.01 to about 0.5% by weight of the target wax formulation. With greater proportions of colorant emulsion being added, the resultant wax composition (or article) obtains a deeper shade of color. 
    
    
     PREFERRED EMBODIMENTS OF THE INVENTION 
     Examples of particularly preferred dispersions and colored wax compositions within the scope of the present invention are set forth below. 
     POLYMERIC COLORANT DISPERSIONS 
     EXAMPLE 7 
     3.8 parts of the undiluted colorant of Example 1 in Table 1, above, was mixed with 16.0 parts of ethoxylated dodecanol (available from Milliken Chemical as Synfac™ DG) and 80.2 parts of sorbitan monooleate (available from Imperial Chemical as Span 80®). The resulting mixture was a viscous, blue-colored, homogeneous solution. 
     EXAMPLE 8 
     3.5 parts of the undiluted colorant of the colorant in Example 1, above, was mixed with 11.5 parts of ethoxylated dodecanol and 85.0 parts of sorbitan monooleate. The resulting mixture was a viscous, blue-colored, homogeneous solution. 
     EXAMPLE 9 
     10.5 parts of the undiluted polyoxyalkylenated polymeric colorant of Example 3, above, was mixed with 14.9 parts of ethoxylated dodecanol and 74.6 parts of sorbitan monooleate. The resulting mixture was a viscous, red-colored, homogeneous solution. 
     EXAMPLE 10 
     9.0 parts of the undiluted colorant of Example 3, above, was mixed with 18.0 parts of ethoxylated dodecanol and 73.0 parts of sorbitan monooleate. The resulting mixture was a viscous, red-colored, homogeneous solution. 
     EXAMPLE 11 
     18.9 parts of the undiluted polyoxyalkylenated polymeric colorant of Example 4, above, was mixed with 81.1 parts of sorbitan monooleate. The resulting mixture was a viscous, yellow-colored, homogeneous solution. 
     EXAMPLE 12 
     12.0 parts of the undiluted colorant of Example 4, above, was mixed with 1.0 part of ethoxylated dodecanol and 87.0 parts of sorbitan monooleate. The resulting mixture was a viscous, yellow-colored, homogeneous solution. 
     EXAMPLE 13 
     9.0 parts of the undiluted polyoxyalkylenated polymeric colorant of Example 6,5, above, was mixed with 1.0 part of ethoxylated dodecanol and 76.0 parts of sorbitan monooleate. The resulting mixture was a viscous, violet-colored, homogeneous solution. 
     COLORED WA COMPOSITIONS 
     Generally, a colorant (or blend of colorants) was added to molten wax and stirred (while the solution remained in a molten state) until the wax solution became an homogeneously colored formulation. This was allowed to cool and form a colored solid. 
     EXAMPLE 14 
     The dispersion of EXAMPLE 7 was introduced into a molten paraffin wax formulation (melting point 130-150° F.) in an amount of about 2.1% by weight. Upon stirring, the composition became a thorough homogeneous medium blue shade. The composition was then poured into a candle mold and allowed to cool. The resultant candle exhibited excellent colorations. 
     EXAMPLE 15 
     The dispersion of EXAMPLE 8 was introduced into a molten paraffin wax formulation (melting point 130-150° F.) in an amount of about 2.3% by weight. Upon stirring, the composition became a thorough homogeneous medium blue shade. The composition was then poured into a candle mold and allowed to cool. The resultant candle exhibited excellent colorations. 
     EXAMPLE 16 
     The dispersion of EXAMPLE 9 was introduced into a molten paraffin wax formulation(melting point 130-150° F.) in an amount of about 0.9% by weight. Upon stirring, the composition became a thorough homogeneous medium red shade. The composition was then poured into a candle mold and allowed to cool. The resultant candle exhibited excellent colorations. 
     EXAMPLE 17 
     The dispersion of EXAMPLE 10 was introduced into a molten paraffin wax formulation(melting point 130-150° F.) in an amount of about 1.0% by weight. Upon stirring, the composition became a thorough homogeneous medium red shade. The composition was then poured into a candle mold and allowed to cool. The resultant candle exhibited excellent colorations. 
     EXAMPLE 18 
     The dispersion of EXAMPLE 11 was introduced into a molten paraffin wax formulation(melting point 130-150° F.) in an amount of about 0.5% by weight. Upon stirring, the composition became a thorough homogeneous medium yellow shade. The composition was then poured into a candle mold and allowed to cool. The resultant candle exhibited excellent colorations. 
     EXAMPLE 19 
     The dispersion of EXAMPLE 12 was introduced into a molten paraffin wax formulation(melting point 130-150° F.) in an amount of about 0.8% by weight. Upon stirring, the composition became a thorough homogeneous medium yellow shade. The composition was then poured into a candle mold and allowed to cool. The resultant candle exhibited excellent colorations. 
     EXAMPLE 20 
     The dispersion of EXAMPLE 13 was introduced into a molten paraffin wax formulation(melting point 130-150° F.) in an amount of about 1.0% by weight. Upon stirring, the composition became a thorough homogeneous medium yellow shade. The composition was then poured into a candle mold and allowed to cool. The resultant candle exhibited excellent colorations. 
     COMPARATIVE EXAMPLES 
     Emulsions comprising the same colorants as in the present invention but utilizing different but similar surfactants (in structure) to those within the present invention were then tested. Their performance as colorants were measured at two different times. First, the resultant emulsion as added to the wax within the mixing vessel was viewed. Second, the resultant molded wax article was viewed. Both measurements were made empirically since the exhibited coloring deficiencies were clear. The following table indicates the surfactants present and the measured deficiencies viewed. The same method for preparing the emulsion (3.8 parts of colorant, 16.0 parts of Synfac™ DG surfactant, and 80.2 parts of other surfactant, all added in an amount of about 2.1% by weight of the wax) as well as producing a molded wax article were followed as for the inventive examples, above. 
     
                                           TABLE 2__________________________________________________________________________  Colora           Performance ResultsEx.  (from above)   Surfactant (description)              Mixing Vessel                       Molded Wax Article__________________________________________________________________________21  Example 1   Ethoxylated Sorbitan              Residual wax                       Majority of colorant                   Monooleate (5EO)          had large colorant                       present at the bottom                                             droplets             of                       the article  22   Example 3        Ethoxylated Sorbitan      Residual wax                       Majority of colorant                   Monooleate (5EO)          had large colorant                       present at the bottom                                             droplets             of                       the article  23   Example 4        Ethoxylated Sorbitan      Residual wax                       Majority of colorant                   Monooleate (5EO)          had large colorant                       present at the bottom                                             droplets             of                       the article  24   Example 5        Ethoxylated Sorbitan      Residual wax                       Majority of colorant                   Monooleate (5EO)          had large colorant                       present at the bottom                                             droplets             of                       the article  25   Example 1        Sorbitan Trioleate        Residual wax                       Very low color                                             contained small                       levels; indicates                                             colorant particles                       poor dispersion  26   Example 3        Sorbitan Trioleate        Residual wax                       Very low color                                             contained small                       levels; indicates                                             colorant particles                       poor dispersion  27   Example 4        Sorbitan Trioleate        Residual wax                       Very low color                                             contained small                       levels; indicates                                             colorant particles                       poor dispersion  28   Example 5        Sorbitan Trioleate        Residual wax                       Very low color                                             contained small                       levels; indicates                                             colorant particles                       poor dispersion  29   Example 1        Sorbitan Monolaurate      Residual wax                       Majority of colorant                                             contained colorant   at                       bottom of                                             droplets                       article  30   Example 3        Sorbitan Monolaurate      Residual wax                       Majority of colorant                                             contained colorant   at                       bottom of                                             droplets                       article  31   Example 4        Sorbitan Monolaurate      Residual wax                       Majority of colorant                                             contained colorant   at                       bottom of                                             droplets                       article  32   Example 1        Sorbitan Hexaoleate       Residual wax                       Very low color                                             contained a large                       levels; majority                                             amount of colorant   of                       colorant at                                             droplets                       bottom of artic1e  33   Example 3        Sorbitan Hexaoleate       Residual wax                       Very low color                                             contained a large                       levels; majority                                             amount of colorant   of                       colorant at                                             droplets                       bottom of article  34   Example 4        Sorbitan Hexaoleate       Residual wax                       Very low color                                             contained a large                       levels; majority                                             amount of colorant   of                       colorant at                                             droplets                       bottom of article  35   Example 5        Sorbitan Hexaoleate       Residual wax                       Very low color                                             contained a large                       levels; majority                                             amount of colorant   of                       colorant at                                             droplets                       bottom of article__________________________________________________________________________ 
    
     Clearly, the performance of substituted sorbitan monooleate and/or sorbitan polyester surfactants exhibited deleterious effects on the colorability and dispersability of the poloxyalkylene polymeric colorant emulsions within waxes. 
     Lastly, a non-sorbitan ester surfactant was tested alone, without an ethoxylated dodecanol present, for its dispersability of the polyoxyalkylene colorants and subsequent colorability within waes. 17 parts per hundred of colorant used in combination with 83 parts of glyceryl monooleate/dioleate. The results are tabulated as follows: 
     
                       TABLE 3______________________________________Colorant  Performance ResultsEx.  (from above)          Mixing Vessel    Molded Article______________________________________36   Example 1 Residual wax contained small                           Poor dispersion with                  colorant droplets              majority of                           colorant                                                 at bottom of                           article  37   Example 3       Residual wax contained small   Poor dispersion                           with                  colorant droplets              majority of                           colorant                                                 at bottom of                           article  38   Example 4       Residual wax contained small   Poor dispersion                           with                  colorant droplets              majority of                           colorant                                                 at bottom of                           article  39   Example 5       Residual wax contained small   Poor dispersion                           with                  colorant droplets              majority of                           colorant                                                  at bottom of                           article______________________________________ 
    
     Again, clearly the sorbitan monooleate alone provides superior performance than with a non-sorbitan ester surfactant. 
     Having described the invention in detail it is obvious that one skilled in the art will be able to make variations and modifications thereto without departing from the scope of the present invention. Accordingly, the scope of the present invention should be determined only by the claims appended hereto.