JPS60179500A - Density control microcapsule and manufacture - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates generally to microcapsules useful as fabric colorants or brighteners, and more particularly to controlled density microcapsules dispersed in aqueous bleaching solutions. The present invention relates to microcapsules having a distribution.

BACKGROUND OF THE INVENTION Various colorants and brighteners are known and useful in treating fabrics. For example, bluing agents are used to mask the undesirable yellow color of fabrics after washing. Typical colorants are dyes and pigments, such as ultramarine, and optical brighteners.

Many colorants are virtually insoluble in aqueous solutions and are in particulate form when added during the cleaning process. During washing and cooling, if the colorant particles are small enough and dispersed in the washing liquid, the particulates will become deposited on the fabric and reduce the yellowing of the fabric by partially compensating for the short wavelength blue absorption. Mask discoloration.

Although the combination of particulate colorants and laundry additives is a convenient means of treating fabrics, young particulate colorants lose their effectiveness in oxidizing environments, such as hypochlorite bleach solutions. .

U.S. Patent No. 4,271,030 Specification ■ discloses a granular pigment,
For example, liquid hypochlorite sea bream white agent with ultramarine
It is said that it is stably suspended in the composition by a flocculant filling 50% of the total amount.

U.S. Pat. No. 3,666,680 discloses an encapsulating material for particles said to be useful in protecting optical brighteners in aqueous bleaches. Ru.

The disclosed encapsulated drug is a styrene monomer, and encapsulation is accomplished by a two-stage one process.

Traditional manufacturing methods for encapsulated brighteners are multi-step or difficult to control, and known compositions with brighteners in aqueous solutions result in sedimentation, flocculation or stability problems. .

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a simple and efficient method for producing microcapsules that are stable in aqueous bleaching solutions and are useful as fabric colorants. Another object of the invention is to have a controlled density distribution, for example a density controlled to approximate the density of an aqueous bleaching solution - and aqueous? The objective is to provide microcapsules that can be dispersed to customers at RT.

Additional objects, advantages, and characteristic features of the present invention will be set forth in part in the following description, and in part will become apparent to those skilled in the art upon consideration of the present invention. On one side, a swamp with a predetermined solution density;
Compositions useful for treating fabrics consisting of a plurality of microcapsules dispersed in body and white liquid
, provided. The plurality of microcapsules have a density distribution within about ±0.05 g 1 cc of the solution density in a bleaching solution, and more preferably within about 0.05 g 1 cc of the solution density in a bleaching solution.
．． 0.005 to about 0.01 g/cc. Preferred microcapsule embodiments have an outer layer and an inner core, the outer layer having a density lower than the solution density, and the inner core being a colorant.

In another aspect of the invention, an aqueous solution containing particulate matter from about 0.1 microns to about 500 microns in diameter in an amount up to about A method for making pigment capsules with controlled density distribution is provided which comprises dispersing an active agent in an aqueous solution and incorporating a coagulant into the solution to form the capsules.

Practice of the present invention results in microcapsules useful as fabric treatment colorants dispersed in aqueous bleach solutions.

Broadly speaking, microcapsules according to the present invention have a diameter of about 0.5 mm.
O11 microns to 500 microns, more preferably about 0.1 microns to about ]0 microns, most preferably about 1
It has a micron diameter and has an outer layer and an inner calyx. The inner core is derived from a granular, substantially water-insoluble material that functions as a colorant for fabrics. includes. For example, among the known and useful fluorescent compounds are coumarins, pyrazines, azoles, and anthraquinones. Suitable dyes and pigments include, for example, ultramarine blue, sulfanthrene dye (available from EI DuPont de Numua), and monastral colorant (available from EI DuPont de Numua). available).

Colorants useful in the present invention are substantially water-insoluble and desirably have a higher density than the aqueous solution in which they are dispersed for fabric treatment. For example, ultramarine has a density of 2.35g/
cc, ultramarine particles begin to precipitate from aqueous solution within about 4 hours even when having small particle sizes under extreme pressure.

The inner core of microcapsules according to the present invention will generally have a diameter of at least about 0.1 microns, and usually will be within the range of about 0.1 to about 10 microns. Unencapsulated particles of this size would settle out of an unstirred solution due to their high density. The microcapsules according to the invention can be dispersed in aqueous solutions,
A particularly preferred composition is one in which the microcapsules are made to have a controlled density distribution approximating the solution density of the desired solution in which they are to be dispersed. Dispersed in salt bleach and has a density of approximately 1.0-1.2 g ZCC approximately 0.01
, more preferably about 0.005.

Typical liquid hypochlorite bleaches used for laundry operations are hypochlorous acid bleaches, which facilitate the removal of stains and soils from fabrics due to the strong oxidizing ability of the hypochlorite ions that are released in aqueous solutions. Contains sodium chlorate, density approximately 1.08g
/Cc. An aqueous solution of thorium hypochlorite is originally basic.

It is well known that hypochlorite ions are stabilized by basic solutions, so regular aqueous hypochlorite bleaches usually contain a small amount of sodium hydroxide or sodium carbonate (
Adjust the pH of the solution to approximately 10.5-12.0).

Aqueous hypochlorite bleaches can also contain additional ingredients and can have a higher pH. For example, U.S. Pat.
, 151,104 discloses a liquid hypochlorite whitening agent with pH #In-14, and U.S. Pat.
No. 71,463 discloses an aqueous hypochlorite solution containing a synthetic detergent.

The method for producing pigment capsules with a widely distributed and controlled density distribution involves preparing an aqueous solution containing pigment granules, dispersing a predetermined amount of a relatively low density polymer and a surfactant into the aqueous solution, and dispersing a suitable coagulation method. It consists of mixing a dissolving agent into it.

By varying the weight ratio of the polymer forming the outer layer and the coloring agent forming the inner core, microcapsules with various desired densities can be produced. For example, microcapsules having ultramarine as an inner layer are usually Outer layer to inner core weight ratio from about 4:1 to about 7!1, preferably from about 511 to 6!
:1.

A particularly preferred embodiment has an average particle size of about 1 micron, an average density of about 1.075 g/cc, and a density distribution of about 0.00
Microcapsules having a weight of 5 g/CC have been produced. Preferred microcapsules are suitable for use in liquid bleaching solutions, such as hypochlorite bleaches having a density of about 1.078 g/cc, preferably about 0% for hypochlorite solutions.
．． It is readily dispersed in amounts of 5 to about 1 part by weight.

The theoretical density of microcapsules can be predicted from formula D) below.

[In the formula, the average density of the microcapsules is 1 (g/cc
) and the weight of the polyethylene (i.e. 'Jit) is M
l (g), and the amount of N (i.e., a small amount) in the inner core material is M2
(g), the density of the polymer is dl, and the density of the inner core material is d2] For example, Ml 7 M2 is 3.04 and dl is 0.
915 g/cc, and d2 is 2.35 g/cc.
Then, the theoretical density of microcapsules is 1.0
It would be 8g/CC. Stokes' law is the following formula (2)
It is useful in predicting suitable microcapsule diameters and acceptable average densities such that the microcapsules float and do not settle in the aqueous solution in which they are dispersed, as shown by .

(2) [1o-1(D2・△d-g)t [In the formula, 0o is the terminal sinking velocity or ascent velocity (m7 seconds), η is the viscosity (kg/sec-m), and D is is the microcapsule diameter (m), △d is the density difference between the microcapsule and the aqueous solution, and g is the vehicle force constant (9,8 ton/m-sec)] Critical terminal velocity (which can be canceled out by Brownian motion and thermal fluctuations) is 1.2 × 10 m7 seconds. Thus, for example, microcapsules with an average density K 1.075 g/cc and an average diameter of 1.5 microns:
Predicted terminal velocity in hypochlorite bleach 3.7 X to
−9 m/s. This predicted terminal velocity is critical II! :It's actually cheaper than AT.

The following experimental methods, materials and results are described for the purpose of illustrating the invention. However, other aspects, advantages, and modifications within the scope of the invention will be apparent to those skilled in the art.

EXPERIMENTAL The general method for preparing pigment capsules according to the invention is to disperse a 75Jr quantity of particles to be encapsulated in an aqueous solution, add sufficient monomer emulsion and stir in the presence of a suitable surfactant. It consists of preparing the emulsion (e.g., mechanically at about 300-800 rpm), adjusting the temperature, maintaining the temperature within the desired range, and incorporating the coagulant into the emulsifying solution. The microcapsules are then cooled to room temperature.

Emulsion? Preferred polymers for AM are ethylene derived hydrocarbon polymers. These polymers have relatively low densities and can be emulsified in aqueous systems with suitable surfactants. A combination suitable for the gun of the present invention -
Surfactant emulsions are commercially available from various companies.

“Bo IJ, (
Poly) BM 20 J, "Bareco" available from Petrolite Corporation.
25n or 1M69J, and fi-A C580-20'' available from Allied Chemical. Table 1 below shows data for these four polyethylene-surfactant systems.

table! Particle size (μ) 0.09 0.09 0.20 0.13
% Active Solids 40 25 40 20 Suitable coagulants are, for example, water-soluble salts that provide polyvalent cations. A particularly preferred coagulant is calcium chloride.

The density of the microcapsules formed according to the present invention is
It was measured on a density gradient column containing an inpropatol/ethylene glycol mixture for saturated NaBr solution. The column was calibrated with glass beads of known density. 17$i of the solution containing the microcapsules was placed in the head of the column, equilibrated to form a narrow blue band), and the density was recorded. Example 1 below illustrates the use of four different polyethylene-surfactant systems and the encapsulation of ultramarine blue ("OMBJ") to prepare thirteen microcapsule compositions according to the present invention. The density distribution of each preparation of Minoro capsules is quite narrow (±0.005 g/
cc) was found.

Example I Composition N015 below was prepared as follows.

Gunjo 5151 (available from Wittaker Clark & Daniels, Inc.)
4.35 g of water and 27 g of polyester M 2047.
Dispersed in 73g. The dispersion was warmed to 75-80° C. and 10 g of calcium chloride (10 qb solution) was slowly added within 10 minutes to effect encapsulation. Then,
The obtained capsules were cooled to room temperature and added with a hypochlorite ion agent to give a concentration of 0.5% by weight (based on ultramarine blue).
diluted to Compositions No. 1-4 and q6 were prepared in a similar manner.

1 6.19 1 1 0.998 2 4.01! 1 1.056 3 4.19 1 1 1.051 4 4.19 + 1 1+063 5 4.39 Words 1 1.075 6 4.58 i l 1.062 Example ■ The following composition! 1o, 7 and 8 were prepared in a similar manner to Example I, but using Pareco 2FIL as the polymer-surfactant emulsion and formulated at room temperature @7 4.91
+ 1 1.08 8 5.20 i 1 1.05 Example ■ The following compositions Nos. 9 to 11 were prepared in a similar manner to Example ■ above, but at room temperature, the polymer-surfactant emulsion Valeco BM-69 was used as the suspension.

9 5.0: l 1.07 10 4.5 + 1 1.06 11 4.0! 1 1.09 Example culm The following compositions N012 and 13 were prepared in a similar manner to RiJ Example I, but using A'0580-20 as the polymer-surfactant emulsion at room temperature. 01
2 4·0 + I LO7 133,8: 11-06 A preferred composition according to the invention consists of an aqueous hypochlorite solution and sufficient of the present microcapsules to provide functional whitening.

Hypochlorite ion is unstable over long periods of time;
Eventually, when in aqueous solution, it converts to chloride ions and chlorate, resulting in a corresponding loss of available chlorine. The overall decomposition of hypochlorite ion to chloride represents an undesirable loss of oxidizing capacity of the solution upon storage. The chemical stability of hypochlorite in the presence of the microcapsules of the present invention was measured over 14 days at 21°C, 32°C and 38°C with an initial pH of 11.2 to 11.6 and is acceptable. It was discovered that

The evening seasoning performance of the present composition and the control composition of several oars was determined by applying a swatch of unwashed cotton (10%) to Tide (Tle).
) washing in the presence of detergents and various compositions;
The increase in whiteness of the swatches was evaluated by instrumental measurement. Washing was carried out in a Kθnmore washing machine in approximately 661°C of industrial soft water containing 102 g of Maid detergent and 256 g of each composition sample. Runs with Tide alone and Tide plus bleach (256 g) were performed as controls. The wash load consists of 5 swatches and polyester/cotton 65/35 ballast 5 bond (
It consisted of approximately 2.27 kg).

The reflectance values (L, a, b) of each sample are Gardner (
Gardner) Xl, + -31 colorimeter and the whiteness value (W)
by) calculated using the formula W=L +3a -31). The whiteness increase (ΔW) was calculated by subtracting the initial whiteness value from the post-treatment value. LSD (i Least Significant Difference) values were instrumented using the standard formula. Uv at a predetermined position in the colorimeter [Novial]
The value of ΔW measured on the filter gives a measure of the blue tinting effect of the sample. The ΔW values measured without the filter in place give a measure of the increased blue-tinting effect of the detergent brightener samples that can occur in these systems.

Table 1 below shows the performance test results for three samples (1-3) formulated with ultramarine blue and full strength hypochlorite bleach. Samples 1 and 2 were encapsulated oMB compositions according to the invention. Sample 3 used a non-encapsulated group back. Sample 4 used detergent only, while sample 5
used detergent and bleach.

Table ■ Sample No. (Nobia Alphy 4 Detergent 0.38 1.47 2.185 Detergent 10 Bleach 1.21 2.17 4.22 LSD O, 390,
550,63 Sample N.

(Nobia Alphy 4 Detergent 24.40 31.32 35.685 Detergent 10 Bleach IL49 27.06 28.46 LSD O
, 590, 640, 58 The above data demonstrate that there is an effect on blue tinting performance in the case of the composition according to the invention and that one incorporation of capsules does not interfere with the blue tinting function.

Although the invention has been described with respect to particular embodiments thereof, it will be appreciated that the invention is susceptible to further modifications. This application is generally in accordance with the original subject matter of the present invention, and is intended to be within the known or customary practice in the art to which the present invention pertains, and to be applicable to the essential features described above and to fall within the scope of the present invention. It is intended to cover any variations, uses, or adaptations of the invention including any deviations from the foregoing disclosure.

Applicant's agent Kiyoshi Inomata

Claims (1)

[Claims] 1. A liquid bleaching solution having a predetermined solution density, and a plurality of microcapsules dispersed in the bleaching solution (provided that the plurality of microcapsules have a solution density of about 0.05 g in the bleaching solution) 1. A composition useful for treating fabrics, characterized in that it has a density distribution within lcc. 2. A plurality of microcapsules have an outer layer and an inner core,
The composition according to claim 1, wherein the outer layer has a density lower than the solution density, and the inner core has a density higher than the solution density. 3. The composition according to claim 2, wherein the inner core is a whitening agent or a coloring agent. 4. The composition of claim 1, wherein the microcapsules are present in an amount of about 0.05 parts by weight to about 1 part by weight of the solution. 5. The composition according to claim 2, wherein the outer layer is polyethylene. 6. The composition according to claim 5, wherein the inner core is ultramarine blue. 7. The solution density is approximately 1. os g/cc, and the outer layer of the microcapsule has a density of about 0.91 to about 0.97 g/cc.
The composition according to claim 6, wherein the composition of claim 6 has an outer layer to inner layer weight ratio of about 4+1 to about 7:1. . 9. Multiple microcapsules have a diameter of approximately 0.1 micron.
9. The composition of claim 8 having a diameter of about 500 microns. 10, 1 coalesced outer layer encapsulating the granular core (but 1
The coalescence layer has a view ratio of about 4+1 to about 7S to the core of the granular material.
1. A microcapsule characterized in that the microcapsule is made of L, and one coalesced layer essentially consists of polyethylene. 11. Microcapsules according to claim ν, 10, wherein the granular core is characterized by a brightening agent or a coloring agent. 12. The microcapsule according to claim 21o, wherein the granular core is ultramarine blue. 13. The average diameter of the microcapsules is about 0.1 microns to about 500 microns, and the microcapsules have an average density of about t, 0.7 g/cc to about 1. Microcapsules according to claim 10, having os g/QQ. 14. Dose a predetermined amount of granules having a diameter of about 1 micron to about 10 microns in a water solution, disperse a predetermined amount of polyethylene and a surfactant in the aqueous solution, and add a coagulant to the aqueous dispersion. A method for producing pigment capsules having a controlled density distribution, characterized in that the pigment capsules are mixed with a pigment capsule having a controlled density distribution. 15. The method of claim 14, wherein the coagulant provides polyvalent cations in the aqueous solution. IO, the amount of polyethylene and the amount of particulates are polyethylene to particulates in solution]74% ratio of about 4 = 1 to about 7:
15. The method of claim 14, which is sufficient to provide 1. 17. The method according to claim 16, wherein the coagulant is ground calcium. 18. The method of claim 16, wherein the granules are ultramarine and have a diameter of about 0.1 microns to about 10 microns. 19. The density distribution of the capsules formed during mixing is approximately 1.0.
17. The method of claim 16, having from 2 g/cc to about 1-10 g,/cc. 201, the capsules formed upon mixing have an average density of about 1.
17. The method of claim 16, having a 0.08 g/cc.