Transparent solid detergent composition

Abstract

A transparent solid detergent includes; 3.5 wt % or above of at least one fatty acid salt selected from the group consisting of compounds expressed by the following general formulas (I)-(III);R—COO−H2N+(CH3)—CH2-CH2-SO3−X+  (I)R—COO−H2 N+—C2—CH2—SO3−X+  (II)R—COO−H2 N+—CH2—CH2—SO2−X+  (III)(wherein the formulas R is a saturated or unsaturated hydrocarbon group with carbon number 7˜23, and X is an alkali metal or organic alkali)sodium salt of fatty acid and/or potassium salt of fatty acid;humectant; andwater.

Description

TECHNICAL FIELD

The present invention relates to a transparent solid detergent composition, and more particularly, to an improvement of counter ions of fatty acid thereof.

BACKGROUND ART

A transparent solid detergent composition has a high-class image from the transparency and also, in case where proper quantity of dye or pigment is added, it is widely used for high-class detergent for face etc. because of its deep color tone or metallic impression.

In prior arts, the transparent solid detergent composition includes a base materials such as fatty acid soap and transparent ingredients such as glycerol sugar etc..

As for the fatty acid soap, alkali metal soaps which have sodium ion or potassium ion etc. as “counter ions” of fatty acid are known.

These fatty acid alkali metal soaps have advantages such as low cost, good foaming and creamy feeling, but also have disadvantages such as slightly large frictional solubility and a feeling of tautness after face washing. When a soap of fatty acid and weak base such as triethanolamine and lysine etc. was used, a feeling of tautness after washing was found, and no sufficient improvement was achieved.

DISCLOSURE OF INVENTION

An object of the invention is to provide a transparent solid detergent composition having improved feeling of use and resistance to frictional solubility etc.

It has been found that a transparent solid detergent composition including fatty acid soap of N-methyltaurine alkali metal salt, taurine alkali metal salt or hypotaurine alkali metal salt can improve the frictional solubility and the feeling of tautness after washing without negative influence to its transparency.

Namely, the transparent solid detergent composition according to the present invention includes; 3.5 wt % or more of at least one fatty acid salt selected from the group consisting of compounds expressed by the following general formulas (I)-(III);

R—COO − H 2 N + (CH 3 )—CH 2 —CH 2 —SO 3 − X +   (I)

R—COO − H 2 N + —CH 2 —CH 2 —SO 3 − X +   (II)

R—COO − H 2 N + —CH 2 —CH 2 —SO 2 − X +   (III)

(wherein the formulas, R is a saturated or unsaturated hydrocarbon group with carbon numbers of 7˜23, and X is an alkali metal or organic alkali)

sodium salt of fatty acid and/or potassium salt of fatty acid;

humectant; and

water.

It is also preferable that mole ratio of “the counter ions” of fatty acid is in following range;

“the counter ions” of general formulas (I)˜(III): 5˜50
sodium:                          40˜95
potassium:                       0˜20.

It is also preferable that the total amount of the fatty acid salt is in 35-55 wt %; humectant is in 15-35 wt %; and water is in 15-25 wt % respectively in the composition.

Also, it is preferable to include polyether humectant which has polyhydric alcohol with three or more hydroxyl groups, 2-100 moles of addition polymerized propylene oxide and not greater than 50 moles of addition polymerized ethylene oxide. The amount of polyether humectant is preferably 5˜50 wt % to the total humectant.

Also, it is preferable that the detergent composition be prepared by heating and dissolving a mixture of the fatty acid salt, humectant and water, and pouring the mixture into a frame, cooling and solidifying.

Furthermore, “a transparent solid detergent composition” in the specification means a substantially transparent composition from which color agents such as dye, pigment are eliminated.

BRIEF DESCRIPTION OF DRAWING

FIG. 1 is an explanatory view of suitable production process of the transparent solid detergent composition according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

The preferred embodiments of the present invention will be explained below.

In this invention, R of the general formulas (I)˜(III) is a saturated or unsaturated hydrocarbon group having a carbon number of 7˜23. As for hydrocarbons used in the present invention, examples are as follows; a straight chain saturated hydrocarbon group such as a heptyl group, an octyl group, anonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group, a tetraeicocyl group; a branched chain saturated hydrocarbon group such as a 2-methyheptadecyl group, 2-ethylpentyl group; a straight chain unsaturated hydrocarbon group such as a 8-heptadecenyl group, oleil group, 4,6-octadecadienyl group; and a branched chain unsaturated hydrocarbon group such as a 2-methyloctadeca-6-enyl group.

As for X used in the above general formulas (I)-(III), examples are as follows; an alkali metal such as sodium, potassium and lithium; and an organic alkali such as triethanolamine, diethanolamine and lysine.

The R—COO— moiety of the fatty acid sodium salt or fatty acid potassium salt is the same as the definition of R—COO— of general formulas (I)˜(III).

It is preferable that the fatty acid of the general formulas (I)˜(III) and the fatty acid of the sodium salt and potassium salt be the same.

Further, it is preferable to prepare the detergent composition by adding an alkali agent comprising the taurine counter ion, sodium ion and potassium ion substantially equivalent to the fatty acid, which is heated and dissolved.

As for humectant used in the present invention, examples are as follows; saccharides or polyol such as sucrose, sorbitol, glycerol, 1,3-butyleneglycol, propyleneglycol, dipropyleneglycol. In these, polyether humectant which has polyhydric alcohol with three or more hydroxyl groups, 2-100 moles of addition polymerized propylene oxide and not greater 50 moles of addition polymerized ethylene oxide is especially preferable. The polyether humectant is preferably included 5˜50 wt % to the total humectant. As for polyhydric alcohol, the following are exemplified; glycerol, diglycerin, pentaerythritol, and dipentaerythritol. Further, various monosaccharides, disaccharides, and oligosaccharides can be used for the polyhydric alcohol.

As for disaccharides used in the polyhydric alcohol of the polyether compound, examples are as follows; trehalose, saccharose, maltose, and lactose. As for polysaccharide, gentianose, raffinose, melezitose, stachyose, cellulose, hemicellulose, starch and chitin glycogen are exemplified. As for sugar alcohol, D-sorbitol, D-mannose and D-mannitol etc. are exemplified. As for sugar carboxylic acid, D-mannonic acid, D-gluconic acid, aldonic acid and uronic acid etc. are exemplified. As for carbohydrate derivative, examples are as follows; inositol, alpha-acrose, glucoson, methylfructopyranoside, sorbitan, ethylglucofuranoside, gluconolactone, arbutin, monoacetylsorbitol, diacetylsorbitan, sorbitan lauric acid ester, sorbitan oleic acid ester, and glucose phosphoric ester.

Also the transparent solid detergent composition according to the present invention can include the following agents in addition to the essential components. Examples are an anionic surface active agent such as soaps that are usually included in a detergent composition, alkyl sulfuric ester (salt), polyoxy ethylene alkyl ether sulfuric acid (salt), hydroxyalkyl ether carboxylic acid (salt), an ampholytic surface active agent such as an imidazoline ampholytic surface active agent and betaine ampholytic surface active agent etc; a nonionic surface active agent such as polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, sugar fatty acid ester, alkyl glycoside, and maltitol hydroxy aliphatic ether; a cationic surface active agent such as trimethylalkyl ammonium chloride etc; a plant extraction component such as swertia herb, peony root, iris, and horsetail; a drug such as tranexamic acid, and arbutin; perfume; and antiseptics.

The transparent solid detergent composition according to the present invention is preferably manufactured as shown in FIG. 1 .

Namely, various kinds of fatty acid and a lower alcohol such as ethyl alcohol are heated and dissolved in at 40-60° C. Added to this are the alkalis that become to “counter ions” and neutralize. To this are added the humectant and other additives, such as the saccharides, polyol and the like. This mixture is dissolved homogeneously. If necessary, perfume and coloring agent are added. This solution is poured into a frame for cooling and solidifying. After cooling, the frame is removed. If necessary these are cut into a predetermined shape and allowed to age and dry for 40-60 days. If necessary, molding polishing, surface drying, wiping the surface and packing are performed.

Preferred embodiments of the present invention will be explained in detail hereunder.

Evaluation method

In the following test examples, evaluations were conducted as follows.

Solidification

Good:          Solidification as a whole
Average (Av.): Solidification as a whole but soft
Bad:           Solidification is not obtained

Transparency

Each sample was cut to the thickness of 20 mm and placed on 26 points printed character and the readability thereof was determined and evaluated according to the following standards.

Very good (V.G.): Clearly readable
Good:             Readable
Average:          Read it with slight difficulty
Bad:              Unreadable

Homogeneity

Good:    Homogeneous as a whole
Average: Partially homogeneous
Bad:     Crystallized as a whole

Foaming

Twenty women panelists (20-40 years old) tested the sample of solid soaps in actual use of face washing, foaming the soaps by hand with tap water, and evaluated according to the following standards.

Very good: Extremely fine foaming
Good:      Fine foaming
Average:   Average foaming
Bad:       Bad foaming

Feeling of Tautness After Washing

Twenty women panelists (20-40years old) tested the sample of solid soaps in actual use of face washing, foaming the soaps by hand with tap water, and evaluated according to the following standards.

Very good: No feeling of tautness after washing
           and extremely fine.
Good:      No feeling of tautness and fine
Average:   Average
Bad:       Feeling of tautness

Frictional Solubility

Frictional solubility was evaluated according to the friction solubility of Japan Industrial Standard K-3304.

A sample fragment of predetermined weight (cross section 15 mm×20 mm) was placed on the film wetted with tap water of 40° C. This film was rotated and the soap was rubbed and dissolved for 10 minutes. The friction solubility of a certain area was evaluated from the weight before and after the friction dissolving.

Very good: 20 or less.
Good:      20˜35.
Average:   35˜50.
Bad:       50 or more.

Counter Ion of Fatty Acid

Transparent solid detergent compositions were prepared by using sodium, sotium N-methyltaurate, sodium N-taurate, and sodiium hypotaurate as the counter ions of mixed fatty acid and various tests were conducted. The results are shown in Table 1.

The salt of the mixed fatty acid (beef tallow fatty acid/coconut oil fatty acid=8/2) was mixed in the proportions of Table 1.

40 wt % of the fatty acid salt, 10 wt % of sorbitol, 5 wt % of glycerine, 10 wt % of sugar, 15 wt % of ethanol and 20% of ion-exchanged water were mixed and the detergent compositions were prepared by frame method.

The mixture was heated 70-80° C. and homogeneously dissolved, and the resultant was poured in a frame. After this process, the composition was cooled and solidified and aged to prepare a solid detergent composition.

The counter ions are added in the amount of equivalent to the fatty acid and shown in mole ratio unless otherwise stated.

	TABLE 1
	Test example
	1	2	3	4
	Sodium	100	80	80	80
	Sodium N-methyltaurate	—	20	—	—
	Sotium N-taurate	—	—	20	—
	Sodium Hypotaurate	—	—	—	20
	Solidification	Good	Good	Good	Good
	Transparency	V.G	V.G	V.G	V.G
	Homogeneity	Good	Good	Good	Good
	Foaming	Av.	Good	Good	Good
	Feeling of tautness	Bad	V.G.	V.G.	V.G
	Feeling of solubility	Good	V.G.	V.G.	V.G

As shown in Table 1, the detergent compositions including “the counter ions” of sodium N-methyltaurate sodium N-taurate, and sodium hypotaurate were clearly improved in foaming, feeling of tautness and frictional solubility etc. in comparison with the counter ion of sodium only even for same fatty acid.

Mole Ratio of Taurine Counter Ion

The inventors conducted tests to determine the suitable “counter ion ratio” (mole ratio) of sodium N-methyltaurate. The test method is the same as the example of Table 1.

TABLE 2
Test example	5	6	7	8	9	10	11	12
Sodium	99	95	90	80	70	60	50	40
N-methyl-	1	5	10	20	30	40	50	60
taurine Na
Solidification	Good	Good	Good	Good	Good	Good	Good	Good
Transparency	V.G	V.G	V.G	V.G	V.G	V.G.	Good	Av.
Homogeneity	Good	Good	Good	Good	Good	Good	Good	Bad
Foaming	Av.	Good	Good	Good	Good	Good	Good	—
Feeling of	Bad	Good	Good	V.G.	V.G.	V.G.	V.G	—
tautness
Frictional	Good	Good	Good	V.G.	V.G.	V.G.	V.G.	—
solubility

As is clear from Table 2, the effect of N-methyltaurine can be observed from the mole ratio of from 5 or more. The effect of the sodium N-methyltaurate fatty acid is observed when it was 3.5 wt % or more of the composition.

Effect of Potassium Ion

Generally the addition of potassium ion has a tendency to promote a disadvantage in solidification, while improving detergency and foaming. Tests were conducted on the addition effect of the potassium ion with the various quantities of sodium N-methyltaurate

The test method is the same as method of Table 1. Proportions of the counter ions were shown in mole ratio.

TABLE 3
Test example	13	14	15	16	17	18	19	20
Sodium	90	85	80	70	60	50	40	30
Potassium	10	10	10	10	10	10	10	10
N-methyl-	0	5	10	20	30	40	50	60
taurine Na
Solidification	Good	Good	Good	Good	Good	Good	Good	Bad
Transparency	V.G.	V.G.	V.G.	V.G.	V.G.	V.G.	Good	—
Homogeneity	Good	Good	Good	Good	Good	Good	Good	—
Foaming	Good	Good	Good	Good	Good	Good	Good	—
Feeling of	Bad	Good	Good	V.G.	V.G.	V.G.	V.G.	—
tautness
Frictional	Av.	Good	Good	V.G.	V.G.	V.G.	V.G.	—
solubility

TABLE 4
Test example	21	22	23	24	25	26	27
Sodium	80	75	70	60	50	40	30
Potassium	20	20	20	20	20	20	20
N-methyltaurine Na	0	5	10	20	30	40	50
Solidification	Good	Good	Good	Good	Good	Good	Bad
Transparency	V.G.	V.G.	V.G.	V.G.	V.G.	V.G.	—
Homogeneity	Good	Good	Good	Good	Good	Good	—
Foaming	V.G.	V.G.	V.G.	V.G.	V.G.	V.G.	—
Feeling of tautness	Bad	Good	Good	V.G.	V.G.	V.G.	—
Frictional solubility	Av.	Good	Good	V.G.	V.G.	Good	—

TABLE 4
Test example	21	22	23	24	25	26	27
Sodium	80	75	70	60	50	40	30
Potassium	20	20	20	20	20	20	20
N-methyltaurine Na	0	5	10	20	30	40	50
Solidification	Good	Good	Good	Good	Good	Good	Bad
Transparency	V.G.	V.G.	V.G.	V.G.	V.G.	V.G.	—
Homogeneity	Good	Good	Good	Good	Good	Good	—
Foaming	V.G.	V.G.	V.G.	V.G.	V.G.	V.G.	—
Feeling of tautness	Bad	Good	Good	V.G.	V.G.	V.G.	—
Frictional solubility	Av.	Good	Good	V.G.	V.G.	Good	—

As is clear from Tables 3 to 5, a 20 or less mole ratio of potassium ion improved forming ability. However, exceeding 20 mole ratio of potassium may have a negative effect on solidification and homogeneity.

Amount of Fatty Acid Salt

In next, the inventors conducted tests for the amount of fatty acid salt in the composition.

A fatty acid salt part and a remaining part were prepared as below and these were compounded and mixed with a proper ratio and the compositions for testing were obtained.

Fatty Acid Salt Part

Salts of mixed fatty acid (C14/C16/C18/isoC18=60/20/10/10) were blended so as to be a mole ratio of fatty acid sodium salt/fatty acid potassium salt/fatty acid sodium N-methyltaurate salt=70/10/20.

Remaining Part

The remaining part was prepared by blending 10 parts of sorbitol, 5 parts of glycerol, 10 parts of sugar, 15 parts of ethanol and 20 parts of ion exchanged water.

The mixture of the fatty acid salt part and the remaining part were heated 40-60° C. and homogeneously dissolved, and the resultant was poured in the frame. After this process, the composition was cooled and solidified and allowed to age to prepare a solid detergent composition.

TABLE 6
Test example	35	36	37	38	39	40	41
Fatty acid salt part	30 wt %	35	40	45	50	55	60
Solidification	Bad	Good	Good	Good	Good	Good	Good
Homogeneity	—	Good	Good	Good	Good	Good	Bad

As a result of Table 6, the blending amount of the fatty acid salt in the composition was preferably 35-55 wt %.

Humectant Amount

A test method for the determination of preferable amount of humectant is as below. Ethanol was added to the mixed fatty acid (C14/C16/C18/isoC18=60/20/10/10) and heated it to about 60° C. in a reaction container. Sodium hydroxide/sodium N-methyltaurate with the proportion of the listed below was added to this and neutralized and obtained the fatty acid soap part. The fatty acid soap part and humectant were blended as listed below, and 10 wt % of ethanol and 20 wt % of ion exchanged water were added and heated 70˜80° C. to dissolve. The detergent compositions were prepared by frame method. The results are shown in Tables 7-10.

	TABLE 7
	Test example
	42	43	44	45	46
Na/N-methyltaurine Na			95/5
Soap part	25	35	45	55	60
Total humectant amount	45	35	25	15	10
Solidification	Av.	Good	Good	Good	Impossible
Transparency	V.G.	V.G.	V.G.	V.G.	—
Homogeneity	Good	Good	Good	Good	—
Foaming	Good	Good	Good	Good	—
Feeling of tautness	Good	Good	Good	Good	—
Frictional solubility	Av.	Good	Good	Good	—

	TABLE 7
	Test example
	42	43	44	45	46
Na/N-methyltaurine Na			95/5
Soap part	25	35	45	55	60
Total humectant amount	45	35	25	15	10
Solidification	Av.	Good	Good	Good	Impossible
Transparency	V.G.	V.G.	V.G.	V.G.	—
Homogeneity	Good	Good	Good	Good	—
Foaming	Good	Good	Good	Good	—
Feeling of tautness	Good	Good	Good	Good	—
Frictional solubility	Av.	Good	Good	Good	—

	TABLE 9
	Test example
	52	53	54	55	56
	Na/N-methyltaurine Na			50/50
	Soap part	25	35	45	55	60
	Total humectant amount	45	35	25	15	10
	Solidification	Bad	Good	Good	Good	Good
	Transparency	—	V.G.	V.G.	Good	Av.
	Homogeneity	—	Good	Good	Good	Av.
	Foaming	—	Good	V.G.	V.G.	Good
	Feeling of tautness	—	V.G.	V.G.	V.G.	Good
	Frictional solubility	—	V.G.	V.G.	V.G.	V.G.

	TABLE 9
	Test example
	52	53	54	55	56
	Na/N-methyltaurine Na			50/50
	Soap part	25	35	45	55	60
	Total humectant amount	45	35	25	15	10
	Solidification	Bad	Good	Good	Good	Good
	Transparency	—	V.G.	V.G.	Good	Av.
	Homogeneity	—	Good	Good	Good	Av.
	Foaming	—	Good	V.G.	V.G.	Good
	Feeling of tautness	—	V.G.	V.G.	V.G.	Good
	Frictional solubility	—	V.G.	V.G.	V.G.	V.G.

As is clear from Tables 7-10, transparency sometimes becomes a little low, when the proportion of N-methyltaurine increases in the counter ions. However, it is possible to improve the transparency by addition of proper amount of the humectant. Especially, when the blending amount of the humectant is 15-35 wt % in the composition, improvement of transparency,, feeling of tautness and solubility can be observed.

Effect of the Polyether Humectant

Ethanol was added to the mixed fatty acid (C14/C16/C18/isoC18=60/20/10/10) and heated to about 60 ° C. in a reaction container. Sodium hydroxide/potassium hydroxide/sodium N-methyltaurate with the proportion of 80/10/10 were added to this and neutralized and the fatty acid soap part was obtained. 40 wt % of the fatty acid soap part and 25% of humectant with the proportions (weight ratio) in Table 11 were blended, and 15 wt % of ethanol and 20 wt % of ion exchanged water were added and heated 40˜60° C. to dissolve the mixture. The detergent compositions were prepared by frame method.

	TABLE 11
	Test example
	62	63	64	65
	Sorbitol	40	40	40	40
	Glycerol	20	15	10	0
	Sugar	40	40	40	40
	POP (9) diglycerylether	0	5	10	50
	Solidification	Good	Good	Good	Good
	Homogeneity	Good	Good	Good	Good
	Foaming	Good	Good	Good	Good
	Feeling of tautness	Good.	V.G.	V.G.	V.G.
	Frictional solubility	Good	V.G.	V.G.	V.G.

As is clear from Table 11, the polyether humectant has a better feeling of tautness and solubility effect in comparison with other humectant components.

Counter Ions of the Formulas (I)-(III)

Ethanol was added to the mixed fatty acid (C14/C16/C18/isoC18=60/20/10/10) and heated to about 60° C. in a reaction container. Counter ions of sodium hydroxide/potassium hydroxide/counter ions in Table 12 with the proportions of 70/10/20 were added to this and neutralized and the fatty acid soap part was obtained. 40 wt % of the fatty acid soap part, 10 wt % of sorbitol, 5 wt % of glycerine, 10 wt % of Sugar, 15 wt % of ethanol and 20 wt % of ion exchanged water were added and heated 40˜60° C. to dissolve the mixture. The detergent compositions were prepared by frame method.

TABLE 12
Ex-
am-		Solidi-	Homo-	Foam-	Feel-	Solu-
ple	Ion	fication	geneity	ing	ing	bility
66	N-methyltaurine Na	Good	Good	Good	V.G.	V.G.
67	N-methyltaurine K	Good	Good	Good	V.G.	V.G.
68	N-taurine Na	Good	Good	Good	V.G.	V.G.
69	N-taurine K	Good	Good	Good	V.G.	V.G.
70	N-hypotaurine Na	Good	Good	Good	V.G.	V.G.
71	N-hypotaurine K	Good	Good	Good	V.G.	V.G.
72	N-methyltaurine TEA	Good	Good	Good	V.G.	V.G.

Because of the results of Table 12, counter ions of the present invention have not to be limited.

The preferred blending examples of the present invention will be explained hereinunder.

All of the blending examples were prepared by frame method and had excellent transparency, resistance to friction solubility and feel of use.

Blending Example I

	Lauric acid	7.0	wt %
	Myristic acid	10.0
	Palmitic acid	3.0
	Stearic acid	6.0
	Iso stearic acid	1.5
	Sorbitol	7.5
	Alcohol	15.0
	Salt of Edete acid	0.1
	Sodium hydroxide	1.1
	Sodium N-methyltaurate	9.2
	Sodium hydroxyalkyl ether carboxylate	3.0
	Salt	0.5
	Sucrose	10.0
	POP (9) diglyceryl ether	5.0
	BHT	0.1
	Coloring agent	q.s.
	Ion exchanged water	Balance

	Lauric acid	5.0	wt %
	Myristic acid	10.0
	Palmitic acid	3.0
	Stearic acid	5.0
	Isostearic acid	3.0
	Glycerol	10.0
	Diglycerin	3.5
	Sorbitol	4.0
	Alcohol	10.0
	Salt of edete acid	0.1
	Sodium hydroxide	3.6
	Sodium N-methyltaurate	3.5
	Sodium hydroxyalkyl ether carboxylate	2.0
	POE (60) hardening castor oil	2.0
	Lauroyl imidazolinium betaine	2.0
	Salt	0.5
	Sucrose	10.0
	BHT	0.1
	Coloring agent	q.s.
	Ion exchanged water	Balance

	Lauric acid	8.0	wt %
	Myristic acid	12.0
	Palmitic acid	4.0
	Stearic acid	6.0
	Oleic acid	4.0
	Sorbitol	11.0
	Glycerol	5.0
	Alcohol	16.5
	Salt of edete acid	0.1
	Sodium hydroxide	4.2
	Sodium N-methyltaurate	5.5
	Salt	0.5
	Sucrose	11.0
	BHT	0.1
	Titanium oxide	0.1
	Coloring agent	q.s.
	Ion exchanged water	Balance

	Lauric acid	7.0	wt %
	Myristic acid	10.0
	Palmitic acid	3.0
	Stearic acid	6.0
	Isostearic acid	1.5
	Sorbitol	7.5
	Alcohol	15.0
	Salt of edete acid	0.1
	Sodium hydroxide	6.0
	Potassium N-taurate	2.1
	Sodium hydroxyalkyl ether carboxylate	3.0
	Salt	0.5
	Sucrose	10.0
	POP (9) diglyceryl ether	0.1
	Coloring agent	q.s.
	Ion exchanged water	Balance

As described above, according to the transparent solid detergent composition of the present invention, it is possible to improve transparency, resistance to solubility, and feeling after washing by using the aforementioned counter ions of fatty acid.

While there has been described what are at present considered to be preferred embodiments of the invention, it will be understood that various modifications may be made thereto, and it is intended that the appended claims cover all such modifications as fall within the true spirit and scope of the invention.

Claims

1. A transparent solid detergent composition comprising;(i) a mixture of fatty acid salts consisting of: (a) 3.5 or more of weight % of at least one fatty acid salt expressed by the following general formula: R—COO−H2N+A−X+ wherein R is a saturated or unsaturated hydrocarbon group having 7 to 23 carbon atoms, H2N+A−X+ is a counter anion selected from the group consisting of: H2N+(CH3)—CH2—CH2—SO3−X+; H2N+—CH2—CH2—SO3−X+; and H2 N+—CH2—CH2—SO2−X+ and X is an alkali metal or organic alkali; and (b) 35 to 55 weight % of sodium salt of fatty acid and/or potassium salt of fatty acid other than fatty acids recited under (a); (ii) 15 to 35 weight % of a humectant; and (iii) 15 to 25 weight % of water.

2. A transparent solid detergent composition according to claim 1, wherein the counter ions of fatty acid are in a mole ratio of counter ions of the formula H2N+A−X+ to sodium ions to potassium ions of fatty acid of about 5-50:40-95:0-20 and wherein said sodium and potassium ions are sodium and potassium ions other than sodium and potassium ions present in the formula H2N+A−X+.

3. A transparent solid detergent composition according to claim 1, wherein the humectant comprises a polyether humectant comprising (i) a polyhydric alcohol having at least three hydroxyl groups and (ii) at least one addition-polymerized alkylene oxide selected from the group consisting of an addition-polymerized propylene oxide and an addition-polymerized ethylene oxide, an amount of the polyether humectant being from 5 to 50% by weight of a total amount of the humectant.

4. A transparent solid detergent composition according to claim 2, comprising, as a percent by weight of the total weight of the composition, 35-55 % of the total amount of the fatty acid salts, 15-35 % of the humectant, and 15-25 % of water.

5. A transparent solid detergent composition according to claim 1, wherein said composition is prepared by heating and dissolving said mixture of the fatty acid salts, the humectant and water, and pouring the mixture into a frame, cooling and solidifying.

6. A transparent solid detergent composition according to claim 1, wherein said polyether humectant includes from 2 to 100 moles of the addition-polymerized propylene oxide and up to 50 moles of the addition-polymerized ethylene oxide.