JPH0717862B2 - Aqueous lake pigment suspension composition - Google Patents

Description

The present invention relates to a pigment suspension composition having a high pigment content.

[Conventional technology and problems]

Pigment suspensions are used in the manufacture of suspension compositions for the coating of shaped articles such as pharmaceutical tablets or pills, confectionery such as candy and the like. Such pigment suspensions are typically stirred into larger volumes of solution to produce coating suspensions used in coating processes. One of the coating methods is generally known as a film coating method, in which a film-forming polymer is contained in a coating agent solution for use. Endicott et al., U.S. Pat. No. 2,954,323, provides an example of such a film coating process.
Another technique often used for confectionery articles such as candy is commonly known as the sugar coating method, in which the pigment suspension is used by adding it to a sugar syrup solution of sugar and water.

The pigment suspensions used for the preparation of the coating suspension composition are preferably sold in the form with the highest possible pigment concentration. However, as the pigment concentration increases, the suspension becomes more viscous and tends to reach high viscosities that eventually make it difficult to drain from the container. Over a longer period of time, the thick pigment suspension may harden to an unusable degree.

In the development of concentrated pigment suspensions, it is desirable to obtain a product in which the pigment particles form a stable suspension and do not settle. The pigment suspension is required to be easily spillable from its container and to retain its uniform properties during its transport and storage until it is used for the preparation of a coating suspension composition. is there.

Signorino U.S. Pat. No. 3,981,984 describes a pigment suspension capable of achieving high pigment concentrations in non-aqueous solvents. This pigment suspension consists of pigment particles, a protective colloid such as hydroxypropyl cellulose and a non-aqueous solvent such as ethanol. The patent teaches that addition of pigment particles to the solvent makes the mixture too viscous, so that additional protective colloids are added to suspend the pigment particles and reduce the viscosity.

With the ever-increasing demands of government enforcement authorities regarding the use of organic solvents, it has become desirable to obtain aqueous pigment suspensions. High pigment contents are usually not achievable and the invention was therefore established as a result of research into the combination of components which make it possible to achieve high pigment particle contents in aqueous suspensions. However, the present invention is also applicable to pigment suspensions in organic solvents containing a sufficient amount of water to dissolve the components hereinafter referred to as viscosity reducers.

[Means, actions and effects for solving problems]

One object of the invention is to provide a pigment suspension with a high pigment content.

Another object of the invention is to provide concentrated pigment suspensions of aqueous solvents or mixtures of water and organic solvents.

Yet another object of the present invention is to obtain a concentrated pigment suspension that easily flows out of the container.

Yet another object of the present invention is to obtain a concentrated pigment suspension which does not settle on standing.

Yet another object of the present invention is a pigment suspension having a high pigment concentration which can be held in a container and transported to a customer and easily mixed with a film-forming polymer solution or sugar solution by stirring. To get.

The above and other objects of the present invention will be apparent from the following description.

The pigment suspension composition of the present invention comprises a mixture of a pigment, a salt of an organic carboxy group-containing compound and a viscosity reducing agent selected from a mixture of such a salt and an acid thereof, and an aqueous solution of sugar syrup.

Suitable pigments for use in the purposes of the present invention include FD & C pigments, i.e. dyes in combination with a metal hydroxide substratum. A variety of lakes are suitable for use in the present invention, including lakes incorporating azo, triphenylmethane, fluorescein and sulfonated indigo dyes. FD & C rake is suitable for use in food, pharmaceutical and cosmetic products.

Rake with a wide variety of strengths (concentrations) have been developed. A lake with a medium dye content is most useful for food and confectionery applications. These lakes are available from various sources. A suitable rake is Warner-Jenkinson Manufact, St. Louis, Missouri.
Crompton & Knowles of Uuring Company (hereinafter abbreviated as "WJ") and Fairlawn, NJ
Manufactured by Corporation (hereinafter abbreviated as "C &K"). For example, the following pigments are commercially available from C & K and WJ.

Yellow # 6/40% Yellow # 6/36% Blue # 1/11% Blue # 2/39% Red # 40/40% Red # 27/36% Red # 3/40% Due to variations in rake manufacturing process It has been recognized that the properties of one particular brand of rake produced by one manufacturer may not be as satisfactory for use in the present invention as the same brand of rake produced by another manufacturer.

For example, it has been found that the blue # 2/39% pigment currently manufactured by WJ is preferred for use in the present invention. Similarly, the blue # 1/11% pigment currently manufactured by C & K has been found to be preferred for use in the present invention.

A 50/50 mixture of C & K and WJ lakes is preferably used. Generally, WJ lakes tend to have darker tones, but can cause thickening. By using a mixture of WJ and C & K lakes, both dark tones and non-thickenings can be obtained more easily. Of course, for use in the present invention, the nature of the particular brand of rake needs to be reassessed by the manufacturer each time the rake is newly developed and whenever there is variation, which can be easily accomplished by those skilled in the art. That is.

The evaluation of each particular property for each particular rake is facilitated by trial and error.

The concentration of the pigment in the pigment suspension composition (by weight) is 20-
It is in the range of 65%. The preferred concentration range achieved is 25-
It is 65%, most preferably 30 to 60%. However, the concentration of pigment achieved in any particular suspension is to a certain extent related to the particular pigment used and for some pigments or brands of pigments more than with other pigments. Can also achieve somewhat higher concentrations.

Viscosity reducing agents are salts of organic carboxy group-containing compounds and mixtures of such salts with their acids. Preferred viscosity reducing agents include salts of compounds with 1 to 3 carboxyl groups. Furthermore, lactones which are considered to be converted into carboxyl group-containing compounds in water have been found to be suitable. Suitable viscosity reducing agents include salts of adipic acid, benzoic acid, citric acid, fumaric acid, succinic acid, maleic acid, lactic acid, tartaric acid and propionic acid, and mixtures of such salts with their acids. It is not limited. In addition, lactones such as ascorbic acid and glucono delta lactone may be used.

The viscosity reducing agent should be at least partially in salt form. A 50/50 mixture of salt and acid is suitable. For example, sodium citrate alone or a mixture of sodium citrate and citric acid gives excellent results. On the other hand, citric acid alone does not exhibit the above effects. It is presumed that the viscosity reducing agent forms a complex or chelate with the lake pigment particles. Furthermore, due to the presence of various dyes in the lake pigment, it is speculated that the metal hydroxide substrate of the FD & C lake is involved in the complexing of the viscosity reducing agent. The resulting complex has electronic properties such that it repels another such complex, thereby providing dispersed pigment particles that form a dilute, lower viscosity suspension, thickening the suspension. And is considered to prevent curing.

The speculation about this complexing or chelating effect is based, in part, on the fact that similar effects are not achieved by acid alone. For example, hydrochloric acid does not work, and when a given viscosity reducer is used in the acid form only, it is less effective or unsatisfactory as compared to using a salt form viscosity reducer.

The presence of the viscosity reducing agent featured in the present invention may provide a significant reduction in the viscosity of the suspension composition. As a result, good flowability of the suspension is obtained. Such a suspension can easily flow out of its container and does not cause any excessive thickening or settling. The viscosity reducing agent is present in the mixture in an amount of 0.05-5% by weight. The viscosity reducing agent is preferably present in an amount of 0.1-1.0% by weight. In many cases, even the use of relatively small amounts of viscosity reducing agents can have a significant and beneficial effect on the properties of the suspension.

When used in confectionery, a very good pigment suspension is obtained with a sugar solution as solvent. The following examples illustrate that all lakes can be used to obtain pigment suspensions based on sugar solutions.

〔Example〕

 Next, the present invention will be further described with reference to examples.

Example 1 The following ingredients were weighed and mixed. Ingredients % Sugar Solution 58.80 Sodium Citrate 0.20 Red Lake # 40/40% 40.00 This sugar solution consists of a mixture of water and sucrose in a ratio of about 4: 6. The resulting suspension showed excellent properties. The suspension was free-flowing and did not thicken for a long time.

The suspension composition of the present invention may further contain a small amount of a conventional preservative in order to prevent contamination and generation of fungi, fungi or other microorganisms. For example, suitable preservatives approved for use in products for human consumption are potassium sorbate and methylparaben. These preservatives may be used in amounts less than 0.2%.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Benjamin El. Mayers United States. New York. Highland Hills. Jial Road. 3 (72) The inventor, Valencia Shii. Malik United States. New Jersey. Fire. loan. Twenty Straight. 13-33 (56) Reference JP-A-58-89660 (JP, A) JP-A-60-40180 (JP, A) US Patent 3981984 (US, A)

Claims (10)

[Claims] 1. A suspension composition comprising a pigment, a salt of an organic carboxy group-containing compound and a viscosity reducing agent selected from a mixture of such a salt and an acid thereof, and an aqueous solution of sugar syrup. 2. The composition according to claim 1, wherein the viscosity reducing agent is a salt of a monocarboxylic acid, dicarboxylic acid or tricarboxylic acid compound. 3. A composition according to claim 1, which comprises 20 to 80% by weight of sugar syrup, 25 to 65% by weight of pigment and 0.05 to 5% by weight of a viscosity reducing agent. 4. The composition according to claim 1, wherein the viscosity reducing agent is in the range of 0.1 to 1.0% by weight. 5. A viscosity reducing agent selected from the group consisting of salts of tartaric acid, citric acid, fumaric acid, adipic acid, maleic acid and ascorbic acid, and mixtures of such salts and their acids. The composition according to the item. 6. A composition according to claim 1 wherein the viscosity reducing agent is selected from the group consisting of tartaric acid, citric acid salts and mixtures of such salts and their acids. 7. The composition according to claim 1, wherein the viscosity reducing agent is a lactone. 8. A composition according to claim 1, wherein the pigment is FD & C lake, D & C lake or carmine. 9. A composition according to claim 1, wherein the pigment is a mixture of lake pigment and titanium dioxide. 10. The composition according to claim 1, wherein the sugar syrup aqueous solution is a mixture of water and sucrose.