Organic compounds -- part of the class 532-570 series – Organic compounds – Carbohydrates or derivatives
Reexamination Certificate
2002-05-02
2004-03-30
Barts, Samuel (Department: 1623)
Organic compounds -- part of the class 532-570 series
Organic compounds
Carbohydrates or derivatives
C536S123100, C536S124000
Reexamination Certificate
active
06713624
ABSTRACT:
FIELD OF THE INVENTION
The invention relates generally to flexible modeling compounds that can be used for molding, extruding, or sculpting shapes or figures. In particular the invention relates to starch-based modeling compounds.
BACKGROUND OF THE INVENTION
Starch-based modeling compounds are well know in the art, such as the compositions disclosed in McVicker et al., U.S. Pat. No. 3,167,440, the disclosure of which is incorporated herein by reference. Starch-based modeling compounds, which are typically used by young children, include a starch-based binder, such wheat flour, rye flour, rice flour, or tapioca flour. The starch-based binder is mixed with water, a salt, a lubricant, and a preservative, according to methods known to those skilled in the art.
Starch is the primary source of stored energy in cereal grains. Starches are composed primarily of amylose, a comparatively low molecular weight straight-chain carbohydrate, and/or amylopectin, a branched carbohydrate having a much higher molecular weight and, in solution, a higher viscosity. For example, wheat starch contains about 25% amylose and about 75% amylopectin; and tapioca starch contains about 17% amylose and about 83% amylopectin. (Percentages herein refer to percentage by weight, unless otherwise specified.) “Waxy” starches contain at least about 90% amylopectin. Waxy corn starch, for example, contains less than about 1% amylose and greater than about 99% amylopectin. Amylose and amylopectin do not exist free in nature, but as components of discrete, semicrystalline aggregates called starch granules. When an aqueous starch solution is heated, gelatinization occurs, during which the crystal structure of starch granules is disrupted, and the starch granules absorb water and hydrate, and the viscosity of the solution increases. See generally David J. Thomas & William Altwell, Starches (1999) at 25-30. Retrogradation is a process involving reassociation of starch molecules that occurs after a freshly-made starch gel is cooled. Id.
The processes of gelatinization and retrogradation affect the characteristics of starch-containing products, such as starch-based modeling compounds. During manufacturing of starch-based modeling compounds, gelatinization occurs, forming modeling compounds that are soft, and easy to manipulate and shape, due to their soft texture and low viscosity. However, retrogradation begins to occur shortly after manufacturing, and is usually well advanced in as little as 48 hours. Retrogradation causes significant hardening of starch-based modeling compounds and increases viscosity. The hardening and increasing of viscosity of the modeling compounds is undesirable because the hardened compounds are more difficult to manipulate and shape, particularly by young children.
Amylopectin starch is known to be resistant to retrogradation. However, when amylopectin is mixed with water and heated, it tends to form a paste having a sticky texture, rather than a soft gel, which is desired for a modeling compound. A sticky texture in a modeling compound causes the modeling compound to be messy for the user to manipulate, as the compound is more likely to stick to hands, molds, toys, furniture, and carpeting. There is a need for a starch-based modeling compound that has a soft, flexible texture, low viscosity, is not sticky, and resists retrogradation and hardening over time.
SUMMARY OF THE INVENTION
According to one aspect of the invention, a starch-based modeling compound includes about 2% to about 10% retrogradation inhibitor. The retrogradation inhibitor can include amylopectin. The retrogradation inhibitor can include a waxy starch, such as waxy corn starch, waxy rice starch, or waxy potato starch.
According to another aspect of the invention, a starch-based modeling compound includes about 20% to about 50% water; about 5% to about 15% salt; about 2.0% to about 4.5% lubricant; about 0.2% to about 1.0% surfactant; about 30% to about 42% starch-based binder; about 0.1% to about 1% preservative; 0% to about 1% hardener; about 2% to about 10% retrogradation inhibitor; 0% to about 25% humectant; 0% to about 0.5% fragrance; and 0% to about 3.5% colorant. The salt can be selected from sodium chloride, calcium chloride, and potassium chloride. The lubricant can be selected from mineral spirits, mineral oil, and vegetable oil. The surfactant can be selected from polyethylene glycol esters of stearic acid, polyethylene glycol esters of lauric acid, ethoxylated alcohols, polyoxyethylenesorbitan monostearate (e.g., Tween® 60, ICI Americas, Inc., Wilmington, Del.), and polyoxyethylenesorbitan monolaurate (e.g., Tween® 20, ICI Americas, Inc., Wilmington, Del.). The surfactant is preferably hydrophilic, and can have an HLB (hydrophile lipophile balance) value of about 12 to about 15. The starch-based binder can be selected from wheat flour, rye flour, rice flour, tapioca flour, and combinations thereof. The preservative can be selected from calcium propionate, sodium benzoate, methyl paraben, ethyl paraben, butyl paraben, and borax. The hardener can be selected from sodium aluminum sulfate, potassium aluminum sulfate, aluminum ammonium sulfate, aluminum sulfate, and ammonium ferric sulfate. The retrogradation inhibitor can include amylopectin. The retrogradation inhibitor can be selected from waxy corn starch, waxy rice starch, and waxy potato starch. The modeling compound can also include an acidulant. The acidulant can be selected from citric acid, alum, and potassium dihydrogen sulfate. The modeling compound can have a pH of about 3.5 to about 4.5. The modeling compound can have a pH of about 3.8 to about 4.0. The humectant can be a glycol. The glycol can be glycerin or a low molecular weight polyethylene glycol.
According to still another aspect of the present invention, a method of preparing a starch-based modeling compound includes the steps of:
(a) providing a mixer;
(b) adding the following ingredients to the mixer:
(1) about 5% to about 15% salt;
(2) about 2.0% to about 4.5% lubricant;
(3) about 0.2% to about 1.0% surfactant;
(4) about 30% to about 42% starch-based binder;
(5) about 0.1% to about 1% preservative;
(6) about 2% to about 10% retrogradation inhibitor; and
(7) about 20% to about 50% water; and
(c) mixing the ingredients for at least about 5 minutes.
The ingredients can also include: 0% to about 1% hardener; 0% to about 25% humectant; 0% to about 0.5% fragrance; and 0% to about 3.5% colorant. The salt, lubricant, surfactant, starch-based binder, preservative, and retrogradation inhibitor can be mixed to form a first mixture prior to adding the water to the first mixture; and the water can be heated to a temperature of at least about 150° F. (about 66° C.) prior to adding the water to the first mixture. The water can be heated to a temperature of at least about 170° F. (about 77° C.) prior to adding the water to the first mixture.
The features and advantages of the present invention will be apparent to those of ordinary skill in the art in view of the detailed description of the preferred embodiment, provided below.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
According to one aspect of the present invention, a starch-based modeling compound includes about 2% to about 10% retrogradation inhibitor. The retrogradation inhibitor can include amylopectin. The retrogradation inhibitor can include a waxy starch, such as waxy corn starch, waxy rice starch, or waxy potato starch.
According to another aspect of the present invention, a starch-based modeling compound includes about 20% to about 50% water; about 5% to about 15% salt; about 2.0% to about 4.5% lubricant; about 0.2% to about 1.0% surfactant; about 30% to about 42% starch-based binder; about 0.1% to about 1% preservative; 0% to about 1% hardener; about 2% to about 10% retrogradation inhibitor; 0% to about 25% humectant; 0% to about 0.5% fragrance; and 0% to about 3.5% colorant.
The water preferably meets the National Primary Drinking Water Specifications (see 40 C.F.R. ch. 1, part 141) or the requirements of ASTM F-963, Standard Consumer Safety Specifi
Doane Jr. Linwood E.
Tsimberg Lev
Barts Samuel
Hasbro Inc.
Henry Michael C.
Marshall & Gerstein & Borun LLP
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