Compositions: coating or plastic – Coating or plastic compositions – Marking
Reexamination Certificate
1999-08-03
2002-04-16
Wu, David W. (Department: 1713)
Compositions: coating or plastic
Coating or plastic compositions
Marking
C524S502000, C524S556000, C524S577000, C525S055000, C106S031090, C106S031860
Reexamination Certificate
active
06372031
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to washable coloring compositions comprising specific low-molecular weight stryrene-maleic anhydride copolymers. Such copolymers provide excellent washability enhancing performance in association with colorants and inks. Also, these specific compounds exhibit low viscosities which allow for greater amounts of washability enhancing copolymers to be added within colorant and ink formulations while simultaneously permitting the retention of sufficiently low overall viscosities of the target compositions. Such copolymers provide highly effective prevention of permanent colorations to certain substrates, such as skin, clothing, and the like, by the inks, dyes, and the like, within the target compositions. Marker styluses, writing implements, and other colorant transfer devices, containing these inventive compositions, are also encompassed within this invention.
DISCUSSION OF THE PRIOR ART
All U.S. and foreign patents cited within this specification are hereby incorporated by reference. The term “washable coloring composition” in conjunction with this invention is intended to encompass marker compositions (such as large childrens' markers and slimmer felt-tip pens, as merely examples), paints, spray-pattern indicators, and other colored compositions which can be removed from certain surfaces through contact with water and/or with detergents.
Washable coloring compositions, such as within ink markers, were developed in the past in order to provide children with writing and/or coloring implements which may not permanently stain or discolor certain surfaces, most notably clothing and skin. Such washable ink marker compositions generally require water-soluble colorants which also have a low affinity for coloring skin, clothing, and other surfaces, but which exhibit much higher affinity for coloring paper substrates. Although water-soluble polymeric colorants are preferred, acid dyes are also well known color components of such marker compositions.
The washability of such compositions is generally dependent upon the solubility of the colorants or dyes utilized, but such a characteristic can be substantially improved by the presence of certain washability enhancing additives within the marker formulation. Such enhancers are a class of compounds (including polymers) which enhance washability and removal of the colorants from undesirable surfaces. Without intending to be bound by any scientific theory, it is believed that these enhancers function by either reacting with potential “stain sites” on the substrate before the colorant or ink, or complexing with the colorant at its reactive sites, thereby preventing the reaction of the substrate with the highly reactive sites of the colorant. In the past, such compounds have included dye-blocking polyaromatic sulfonates and their salts, such as described in U.S. Pat. No. 5,116,410 to Miller, European Patent Application No. 557,115 A1 to Kaiser et al., and PCT Application No. WO 98/36032 to Santini et al. Such specific dye-blockers have proven somewhat useful in preventing permanent colorations on certain substrates; however, many (such as sulfonated phenol/formaldehyde condensation products) are highly colored and as such tend to have an adverse effect on the brightness of some shades of the target marker composition, producing a shade with a dull, dirty appearance. This problem is particularly noticeable with regard to lighter color shades. As a result, it has proven difficult to produce certain colored markers without requiring extra amounts of colorant, etc., to compensate for the interference from the dye-blocker compounds. Furthermore, many of the prior art dye-blocker compounds possess very high viscosities which, when incorporated within standard ink markers, translate into higher overall viscosities for those target formulations. Such marker compositions generally must exhibit a viscosity of below about 7.0 centipoise in order to function properly and permit adequate flow of the colorant composition through the marker nib of the stylus. In order to adjust the viscosity, it has been necessary to reduce the amount of dye-blocker compound present in the target composition, which, in turn, translates into a less effective washable marker composition. The greater amount of dye-blocker compound, the greater the ability to prevent discolorations of certain substrates. Thus, there is a need to provide a washability enhancing agent within washable marker formulations which can be utilized in high proportions and which does not deleteriously increase the viscosity of the target composition.
Furthermore, the great amount of prior art dye-blocker compounds within target marker compositions has limited the use of such compositions to those stored within relatively large marker styluses (such as childrens' markers). A washability enhancing compound which can be utilized in relatively high proportions to permit increased washability while simultaneously not deleteriously increasing the intrinsic viscosity of the target composition would provide a heretofore unknown advantage within the washable coloring composition art.
DESCRIPTION OF THE INVENTION
It is thus an object of the invention to provide a washability enhancing compound of low molecular weight and low viscosity which is compatible with inks, colorants, dyes, and the like. It is another object of this invention to provide a washability enhancing compound which can be added in very high proportions to a marker composition without increasing the viscosity a deleteriously high amount for standard marker performance. A further object of the invention is to provide a washable marker comprising a marker composition which is easily removed from surfaces such as skin and clothing but exhibits a high affinity for standard writing surfaces, such as paper. Yet another object of this invention is to provide a relatively inexpensive and yet highly effective stain blocker compound for use within washable marker compositions.
The present invention encompasses specific low molecular weight styrene/maleic anhydride copolymers at least a portion of which conform to the following structure (I):
wherein m is from about 1 to about 3, n is from about 6 to about 40, and X is a counter-ion. Such a counter ion may be an alkali metal (such as sodium, potassium, and the like), hydrogen, ammonium, or an amine. The molecular weight of this invention copolymer should be at most about 10,000, preferably from about 800 to about 8,000, and most preferably from about 1,200 to about 1,800. Such a specific copolymer thus must also possess an intrinsic viscosity of from about 1.0 to about 20 centipoise, preferably from about 1.5 to about 16, more preferably from about 1.5 to about 7, and most preferably from about 2 to about 6. Such copolymers, although they may exhibit intrinsic viscosities greater than the target 7.0 centipoise, are generally present with a certain solids content prior to introduction within the target compositions. Upon mixing, the solids are dissolved and the overall viscosity of the resultant composition should be at most about 7.0 (if a marker composition is desired), although the final viscosity may be much higher if other types of washable coloring compositions are desired.
Such a copolymer exhibits an affinity for undesirable writing surfaces (such as skin, clothing, and the like) greater than for other writing surfaces, such as paper (cellulosic-based or otherwise). Furthermore, colorants, dyes, pigments, inks, and the like, appear to exhibit an affinity for this specific type of copolymer which is less than the affinity such compounds exhibit for desirable writing surfaces, such as paper. As a result, this inventive low molecular weight coplymer has proven to be an effective washability enhancing component to prevent permanent colorations (and to facilitate the removal of colorations) from undesirable writing surfaces (again, such as skin, clothing, and the like).
The low molecular weight is necessary in order to provide a low viscosity for the co
Valenti Michael A.
VanDahm Richard A.
Egwim Kelechi C.
Milliken & Company
Moyer Terry T.
Parks William S.
Wu David W.
LandOfFree
Washable coloring compositions comprising low... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Washable coloring compositions comprising low..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Washable coloring compositions comprising low... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2921072