JPH0670185B2 - Coloring composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a color forming composition that can be used for various products such as toothpaste and shampoo, and in particular, a color forming composition that produces a vivid color by an external action. It is about.

[Conventional technology]

In general, in consumer goods, by utilizing changes in conditions and conditions of use such as carbonless paper or color-changing gum, a different color tone from the color tone before use can be expressed to create new colors. Some products have added product value, and such functional addition is also desired for other products.
For example, regarding toothbrushing, the degree of cleaning of teeth and the number of times of brushing correlate almost with each other.The greater the number of times of brushing, the higher the cleaning effect, but generally the number of times of brushing is determined by each person's habits. The current situation is that there is no standard for whether or not it is. Therefore, there is a demand for toothpaste that informs the end point of brushing by, for example, a color change.

Therefore, the following techniques have already been proposed for imparting such a function.

(I) When a dye coated with a white pigment is used, the coating layer is peeled off by a mechanical force such as a frictional force or a shearing force when necessary to develop the color of the core dye (JP-A-60-16913, JP-A-55). -1
No. 53709) Method.

(Ii) A method in which activated clay, zeolite, etc. are mixed with a coating or microencapsulated product of a coloring organic compound having a conjugated double bond that reacts with them, and the coating is destroyed by mechanical force to cause a chemical reaction to develop a color. (JP-A-49-1737) or a method of applying a chemical reaction such as a redox reaction.

(Iii) A method that utilizes changes in the oral cavity such as changes in pH and reaction with saliva (amylase).

However, in these methods, since the color-forming substances were limited to pigments and oil-soluble dyes, the color tone produced when used in an aqueous system was not fresh, and moreover, the color change due to only dispersion was almost continuous, so the color development was continuous. In addition, there is a problem with the safety of the color former, and the above method was insufficient for use as a time indicator for toothpaste. On the other hand, mix a water-soluble dye with a fresh color with a carrier (kaolin),
There are some examples of coating with a hydrophobic membrane material or gelatin and mixing it in an aqueous system, but water molecules or organic solvent molecules (such as ethanol) may permeate the membrane material and elute the dye, and the elution can be suppressed. However, when the coating was broken, the dye was immediately eluted by water molecules, which was unsuitable as a time indicator.

[Problems to be solved by the invention]

Therefore, an object of the present invention is to provide a color forming composition which can be used in an aqueous solvent system and shows a clear and clear color change in a predetermined time.

[Means for solving problems]

The present invention uses a water-insoluble cationic polymer as a base material for immobilizing a dye, and a water-soluble anionic dye is sorbed or ionically bound to the base material to immobilize the immobilized dye, which is specified in an aqueous medium. When the surfactant of is acted, an exchange reaction occurs between the water-soluble anionic dye and the surfactant,
This is based on the finding that the water-soluble anionic dye gradually diffuses in the aqueous medium, the bright color of the water-soluble anionic dye is developed, and the above problems can be effectively solved.

That is, the present invention comprises (A) an immobilizing dye in which a water-soluble anionic dye is fixed to a water-insoluble cationic polymer and (B) an ionic or semipolar nonionic surfactant, ) Is coated with a member for surface coating, a coloring composition is provided.

As the water-soluble anionic dye of the component (A) used in the present invention, any of those having an anionic functional group such as a carboxyl group and a sulfonate group in the molecule can be used, but it is safe for household consumer products. From this point of view, the water-soluble anionic dyes described in the official standard for food additives or the standard for cosmetic raw materials are preferable. Specifically, Red No. 2 (Amaranth), Red No. 3 (Erythrosin), Red No. 102 (New Coccin), Red No. 104 (1) (Ploxin B), Red No. 105 (1) (Rose Bengal) ), Red 106 (acid red), yellow 4 (tartrazine), yellow 5 (sunset yellow FCF), green 3 (fast green FCF), blue 1 (brilliant blue FCF), blue 2
No. (indigo carmine) and the like are exemplified. These dyes may be used alone or in combination of two or more.

As the water-insoluble polymer used as the carrier for the dye, any water-insoluble polymer having a cationic functional group in the molecule can be used. Specific examples thereof include bisphenol / epichlorhydrin type epoxy resin piperazine polycondensate [trade name: Trepal (Toray)], a copolymer of an acrylic ester and methacryloyloxyethylene trimethyl halide, and chitosan. It The form of the above water-insoluble cationic polymer is arbitrary, but fine particles are preferable, and those having a large surface area are preferable in order to sorb or ionically bond the water-soluble anionic dye at a high ratio per unit weight. Therefore, it is desirable to use those having a surface area of 0.1 to 500 m ² / g, preferably 1 to 500 m ² / g, and a particle diameter of 0.1 to 500 μm, preferably 1 to 20 μm.

The immobilized dye of the component (A) can be prepared by any method. For example, a water-soluble anionic dye and water-insoluble cationic polymer particles are mixed with a solvent such as water or ethanol under acidic conditions, and both are mainly ionized. It can be easily prepared by drying and pulverizing after the active binding. The amount of the water-soluble anionic dye immobilized on the water-insoluble cationic polymer particles is about the ionic equivalent, but the sorption on the particles enables stable immobilization even if the amount of the ionic equivalent or more. Incidentally, as a guide, it is preferable to use 0.5 to 20 parts by weight of the water-soluble anionic dye per 100 parts by weight of the cationic polymer.

The surfactant used as the component (B) of the present invention is an ionic or semipolar nonionic surfactant, and the following are exemplified.

Anionic surfactants having 8 to 16 carbon atoms alkylbenzenesulfonate (abbreviated as C ₈ -C _16. Hereinafter the same), alpha-olefin sulfonates of C ₈ -C _20, alkyl of C ₈ -C ₁₆ (alkenyl ) Sulfate salt, polyoxyethylene alkyl (alkenyl) with C _{8 to} C ₁₆ and ethylene oxide addition mole number 1 to 100
Sulfuric esters, fatty acid salts of C ₈ -C _18, acyl sarcosinates of C ₈ -C _22, fatty acyl -L- glutamate C ₈ -C _22, alkyl naphthalene sulfonates C ₈ -C _16, C _{8 to} C ₂₀ fatty acid monoglyceride ester salt, rosin acid salt, C _{8 to} C ₂₀ alkyl (alkenyl) group in the main chain, and a C _{1 to} C ₃ alkyl group or an alkali group which forms an ester bond with the main chain (alkali ( (Earth) α-sulfo fatty acid salt composed of metal, C ₆ ~
C ₂₀ dialkyl sulfosuccinate, C _{8 to} C ₂₀ alkane sulfonate, C _{8 to} C ₂₀ alkyl phosphate, cholate, C _{8 to} C ₂₄ alkyl group or alkyl phenyl group-containing ethylene oxide Illustrative are phosphoric acid monoester salts and diester salts having an addition mole number of 2 to 50. Na, K, Mg, Ca, or triethanolamine is used as the counterion of these anionic surfactants. The above surfactants can be used alone or in combination of two or more.

Mono-long chain alkyl quaternary ammonium salt cationic surfactant C ₁₀ ~C _24, C
₁₀ mono-long chain alkyl benzyl quaternary ammonium salts -C _24, mono-long-chain alkyl ethoxy quaternary ammonium salts of C ₁₀ -C _24, benzalkonium chloride, benzethonium chloride and the like. These can also be used alone or as a mixture of two or more kinds.

Amphoteric surfactants C _{8 to} C ₂₂ alkylbetaine-type and alkylimidazolinium betaine-type amphoteric surfactants are listed.

Semi-polar nonionic surfactant C _{8 to} C ₂₀ amine oxide and C _{8 to} C ₂₀ sulfoxide, and further C _{8 to} C ₂₂ fatty acid dialkylol amide and its ethylene oxide adduct (ethylene oxide addition The number of moles is 2 to 20 moles). These surfactants can be used alone or in combination.

Of the above-mentioned surfactants, sodium lauryl sulfate is particularly preferably used in the present invention.

In the present invention, the components (A) and (B) can be used in arbitrary amounts, but the components (A) / (B) can be used in 0.1 / 10 to 10
It is preferable to use at 1/1 (weight ratio), preferably 1/10 to 5/1.

In the present invention, the components (A) and (B) are contained in such a form that the water-soluble anionic dye in the component (A) and the surfactant of the component (B) undergo an exchange reaction by an action from the outside. There is. Specifically, as in the case where the component (A) is encapsulated, the case where the surface of the component (A) is covered with a colorless, white or light-colored material, This may be the case when the coating is destroyed.

The surface coating member is nitrocellulose,
Polymers such as ethyl cellulose, chitosan, sodium polyacrylate, polyvinyl alcohol, and white pigments such as titanium oxide, silicon oxide, calcium phosphate,
Calcium carbonate, aluminum hydroxide, magnesium phosphate, magnesium carbonate, talc, acid clay and the like can be used. At this time, it is also possible to adjust the mechanical strength of the film material, control the breaking speed due to the mechanical destructive force, and adjust the color development start time.

Color development by the color forming composition of the present invention is performed in an aqueous medium. Here, the term "in an aqueous medium" includes not only water but also the case where an organic solvent such as ethyl alcohol, propylene glycol, or glycerin is added to water.

The color-forming composition of the present invention is based on the above-mentioned constitution, but, for example, a fragrance, an organic acid salt, a water-soluble polymer, an oil component or the like can be added.

〔The invention's effect〕

By using the color-forming composition of the present invention, in an aqueous medium, it is possible to obtain a clear coloration in a low concentration region peculiar to a water-soluble dye, which is different from the coloration of a pigment or solubilization of an oil-soluble dye. .

When a polymer other than the cationic polymer is used as a carrier, the dye is eluted before use, whereas the method of the present invention allows the water-soluble dye to be stably immobilized on the cationic polymer, By acting an ionic surfactant or a semipolar nonionic surfactant on the immobilized dye due to the action, the color density changes with time, so that it can be widely applied as a time indicator for toothpaste, shampoo, etc.

Next, the present invention will be described with reference to examples, but the present invention is not limited thereto.

〔Example〕

Example 1 Immobilization of component (A) in which blue color No. 1 which is a water-soluble anionic dye is immobilized on bisphenol epichlorhydrin type epoxy resin piperazine polycondensate [average particle size 5 μ, trade name: Trepal (Toray)] A dye was used. Next, to 25 g of the fixed dye, 50 g of a 10% ethyl acetate solution of nitrocellulose as a polymer for coating the fixed dye was added, and the mixture was sufficiently kneaded in a mortar to obtain a dye lump. This mass is then added to a volume of 30
Put in a 0 ml small crusher, add 70 g of titanium oxide while crushing and mix, form a coating layer of titanium oxide on the surface of the pigment lumps coated with nitrocellulose, and then dry to have a particle size of 10 to 1000 μ Some extent of surface coated dye particles was obtained.

The particle composition is shown below. Here, the dye immobilization rate refers to the dye content rate in the immobilized dye.

Surface coating dye particle composition: Next, 2% of the above-mentioned surface-coated dye particles was added to the following toothpaste containing the component (B) sodium lauryl sulfate to prepare a toothpaste containing the coloring composition of the present invention.

Next, add 1g of physiological saline to 1g of the above toothpaste composition and add 3x10
Using a toothbrush (wrist lion, normal hardness) on a cm Teflon plate, brushing at 400 gr / cm ² brushing pressure and 120 strokes / min, and the bluishness of the desired foam as a b value by a color difference meter. Difference in b value Δb (Δb = b Formulation 1) between a system containing an anionic surfactant for causing an exchange reaction (formulation 1) and a system not containing it (formulation 2)
-B Formulation 2) is collectively shown in Table-1.

In the above experiment, in both systems of Formulations 1 and 2, the surface-coated polymer particles were destroyed by brushing to cause the exposed dispersion of the immobilized dye, but it is clear from Table 1 that sodium lauryl sulfate is anionic dye and ion. In a system (prescription 2) which does not contain an ionic surfactant in a system (invention product: formulation 1) in which coloration is caused by a dye released by an exchange reaction, and which is only colored by an immobilized dye exposed and dispersed by brushing (formulation 2). It can be seen that there is a large difference in the degree of foam coloring depending on the value over time.

Example 2 Surface-coated particles were prepared in the same manner as in Example 1 except that various dyes shown in Table 2 were used. Next, using these particles, a toothbrush (wrist lion,
(Normal hardness), the surface-coated dye particles were destroyed by brushing for 2 minutes at a brushing pressure of 400 g / cm ² and a stroke number of 120 times / min to expose the immobilized dye. 2% of the obtained powder was added and dispersed in a 2 wt% sodium lauryl sulfate aqueous solution, and the mixture was shaken at 35 ° C for 3 minutes (stroke number: 120
After 10 times / min), the mixture was filtered through a 0.45 μ membrane filter, the absorbance of the filtrate was determined at the maximum absorption wavelength of the dye, and the amount of free dye was determined from the calibration curve prepared in advance.

The results are shown in Table 2 together with the dyes used.

As is clear from Table-2, in the water-soluble anionic dye immobilization system, a large amount of dye was released from the exposed immobilization dye based on the exchange reaction, and remarkable coloration was observed in the filtrate, but in the oil-soluble dye immobilization system, Almost no coloration of the filtrate was observed.

Example 3 The same surface-coated dye particles as in Example 1 were used, and powders crushed by the brushing method (brushing pressure 400 g / cm ² , stroke number 120 times / min, brushing time 2 minutes) as in Example 2 were used. % Surfactant and 2% aqueous solution of inorganic electrolyte, the amount of free dye was determined in the same manner as in Example 2, and the contribution of the surfactant to the release of dye was investigated. Table 3 shows the results together with the surfactants and the inorganic electrolytes.

As is clear from Table 3, when an ionic or semipolar nonionic surfactant is used, coloring by a free dye based on an exchange reaction occurs, whereas a mere inorganic ion or nonpolar nonionic surfactant is used. Then, it can be seen that the release of the dye does not occur.

Example 4 The amount of free dye was determined in the same manner as in Example 3 except that the same surface-coated pigment particles as those used in Example 1 were used and the amount of sodium lauryl sulfate added was changed, and the concentration of the surfactant was determined. I investigated the effect of. The results are shown in Table-4.

From Table 4, it can be seen that the amount of free dye is the largest in the micelle forming region, and it is somewhat reduced at the liquid crystal forming concentration due to the decrease in the mobility of the surfactant molecule. The amount of free dye below the critical micelle concentration is clearly smaller than above the critical micelle concentration.

Example 5 Yellow iron oxide prepared in the same manner as in Example 1 using the same surface-coated dye particles as those used in Example 1 or, as a comparative example, yellow iron oxide having an average particle size of 0.5 μ instead of the immobilized dye. The following dentifrice compositions were prepared using the contained surface-coated pigment particles.
Next, the degree of coloration when brushing in the oral cavity for a predetermined time was visually judged by the following evaluation criteria.

Coloration Evaluation Criteria Score Evaluation 0 points No coloration (0 to 2ppm) ^{* 3} 1 point Slightly colored (3 to 19ppm) 2 points Somewhat colored (20 to 29ppm) 3 points Considerable color (30 to 49ppm) ) 4 points Vivid coloration (50ppm <) ^{* 3} () The above toothpaste formulation is a color sample in which sodium lauryl sulphate is used as a surfactant and free blue No. 1 is used instead of the surface coating pigment particles. For blue No. 1, the panel is 5 people, and the result is shown by the average of 5 people. The results are summarized in Table-6.

From Table-6, the dentifrice containing the color forming composition of the present invention is 2 to
It turns out that the color changes after 2.5 minutes, the end point of brushing is clearly detected, and the degree of coloring increases with time and becomes more vivid, so that the brushing time can be properly controlled, which is very excellent.

Claims (1)

[Claims] 1. A component (A) containing (A) an immobilizing dye in which a water-soluble anionic dye is fixed to a water-insoluble cationic polymer and (B) an ionic or semipolar nonionic surfactant. Is coated with a surface coating member.