JPH0461913B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a granular detergent composition containing an α-sulfo fatty acid ester salt, in which hydrolysis of the α-sulfo fatty acid ester salt is suppressed when stored for a long period of time. In recent years, phosphates in detergents have been regulated for environmental reasons, and granular detergents that can provide good detergency and powder properties without the use of phosphates have been studied, including alternative builders and interfaces. This is done in terms of the active agent itself. Among these, α-sulfo fatty acid ester salts have attracted attention because they have excellent detergency and dirt dispersibility, are insensitive to calcium, and exhibit detergency even in highly hard washing water. Powdered detergents using this activator have been reported in Japanese Patent No. 47-12582 and the like. However, there is a problem in that α-sulfofatty acid ester salts undergo hydrolysis and ester bonds are cleaved, and are easily converted into α-sulfofatty acid di-salts that are poorly soluble in water and have poor surface activity. As a countermeasure for this, for example, JP-A-52-117908
It is reported in the above publication that polyethylene glycol is added to a detergent slurry containing an α-sulfo fatty acid ester salt to prevent hydrolysis of the α-sulfo fatty acid ester salt during spray drying. In addition, JP-A No. 50-151905 discloses that the ester bonds of α-sulfo fatty acid ester salt powder are easily broken during storage, and that this is because powdered α-sulfo fatty acid ester salt can be spray-dried. It has been reported that this is promoted during preparation, and as a countermeasure to this problem, the combined use of a hindered phenol compound and a hydroxypolycarboxylic acid or a salt thereof has been proposed. Furthermore, JP-A No. 52-28507 proposes the use of a specific alkali builder because α-sulfo fatty acid ester salts are hydrolyzed over time in the coexistence of an alkali builder such as sodium silicate. ing. However, none of the above-mentioned methods is still satisfactory, and in particular, the lack of sufficient storage stability leads to deterioration over time in the market, and improvements have been delayed. In addition, since alkaline builder is an essential ingredient in laundry detergent and is also necessary for powder physical properties, it is necessary to use a general-purpose alkaline builder and α
- It has been desired to stably coexist a sulfo fatty acid ester salt. As a result of intensive studies from the above viewpoint, the present inventors have found that by powder blending powder of an acidic substance that is solid at room temperature into a granular detergent containing α-sulfo fatty acid ester salt, α- The present inventors have discovered that the hydrolysis of sulfo fatty acid ester salts over time is suppressed, and that hydrolysis is also prevented even in the coexistence with a general-purpose alkali builder, leading to the completion of the present invention. That is, the granular detergent composition of the present invention contains 1 wt% of the powder and granular detergent containing the α-sulfo fatty acid ester salt.
One or more selected from boric acid, organic carboxylic acid, organic oxycarboxylic acid, nitrilotriacetic acid, ethylenediaminetetraacetic acid, para-toluenesulfonic acid, aluminum sulfate, hydrogen sulfate, hydrogen sulfite, and salts thereof, whose aqueous solution has a pH of 7 or less, It is characterized by being mixed with powder. The present invention will be explained in more detail below. The α-sulfo fatty acid ester salt used as the main active ingredient in the present invention has the general formula () (In the formula, R ₁ and R ₂ represent an alkyl group, and M
is a cation. ) In the formula, R ₁ is preferably an alkyl group having 4 to 20 carbon atoms, and R ₂ is preferably an alkyl group having 1 to 6 carbon atoms, and these may be linear or branched. It may be in the form of Moreover, as _R2 , a methyl group, an ethyl group, an n-propyl group, and an isopropyl group are suitable. M is sodium;
Alkali gold such as potassium is preferred, and other examples include magnesium. Such α-sulfo fatty acid ester salts have a carbon number of 6 to 22, for example.
It can be produced according to a conventional method using a fatty acid as a raw material, and hydrogenated beef tallow fatty acid and hydrogenated palm oil fatty acid are preferable as the raw fatty acid. The oxidizing substance used in the present invention is one that is solid at room temperature, and a 1 wt % aqueous solution thereof preferably has a pH of 7 or less. Among these acidic substances, boric acid and sodium bisulfite are most preferred, dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, and fumaric acid, oxycarboxylic acids such as tartaric acid, malic acid, and citric acid, nitrilotriacetic acid, and ethylenediaminetetraacetic acid. Carboxylic acids such as acetic acid are also preferred acidic substances, and para-toluenesulfonic acid, aluminum sulfate, sodium hydrogen sulfate, and the like are also used. To produce the granular detergent composition of the present invention, α-
The sulfo fatty acid ester salt or, if necessary, a detergent slurry containing detergent components such as other active ingredients and builders is spray-dried, or a detergent composition containing the α-sulfo fatty acid ester salt is granulated into powder. It can be produced by making it into granules and powder-blending the granular detergent with an acidic substance. At this time, by reducing the particle size of the acidic substance, the hydrolysis prevention effect can be further enhanced. For example, a granular detergent with a particle size of about 200 to 1000 μm and a granular acidic substance with a particle size of about 20 to 400 μm are mixed. Further, the mixing ratio of the two is preferably such that 0.005 to 0.1 part by weight of the granular acidic substance is added to 1 part by weight of the α-sulfo fatty acid ester salt. The granular detergent composition of the present invention can further contain the following optional components as required, and can effectively prevent the decomposition of α-sulfo fatty acid ester salt over time even when it contains an alkali builder. . Alkali builders are usually contained in detergent compositions in an amount of 5 to 40 wt%. These ingredients include alkylbenzene sulfonates, alkyl sulfonates, α-olefin sulfonates, alkyl sulfates, alkyl polyether sulfates, anionic surfactants such as fatty acid soaps, alkyl ethoxylates, and alkyl phenyl ethoxylates. , nonionic surfactants such as alkyl alkanolamides, amphoteric surfactants such as alkyl betaines, alkali builders such as polyethylene glycol, sodium silicate, sodium carbonate, sodium bicarbonate, sodium tripolyphosphate, sodium pyrophosphate, sodium citrate,
Examples include chelate builders such as sodium ethylenediaminetetraacetate and sodium nitrilotriacetate, and neutral builders such as zeolite and sodium sulfate. These components may be blended with α-sulfo fatty acid ester salts in a detergent slurry and spray-dried to make powder and granules so that they coexist in detergent particles, or they may be made into powder and granules separately and powder blended. It's okay. According to the granular detergent composition of the present invention, by powder-mixing the granular acidic substance to the granular detergent containing α-sulfo fatty acid ester, even in the coexistence of an alkali builder, α-sulfo fatty acid Decomposition of the ester salt over time is effectively suppressed, and deterioration of the performance of the detergent composition during long-term storage can be prevented. Example A powdery detergent (average particle size: 400μ) having the following composition was prepared by a spray drying method. Sodium salt of α-sulfo fatty acid methyl ester (number of carbon atoms in fatty acid residue: 14-18) 15wt% Sodium alkyl sulfate (number of carbon atoms in alkyl group: 12-16) 10wt% No. 2 silica 10wt% Zeolite 10wt% Water 4wt% Amirabilite Balance This powdery granular detergent is mixed with powdery acidic substances and other powdery substances shown in Table 1 at the weight percentages shown in Table 1 to form a granular detergent composition. It was created. These compositions (Comparative Examples Nos. 1 to 4 and Examples
The hydrolytic increase rate of Nos. 1 to 17) was measured by the following method, and the results are shown in Table 1. Measuring method of hydrolysis increase rate The total amount of active agent T is determined by methylene blue back titration method, and the total amount of α-sulfo fatty acid ester salt and α-sulfo fatty acid di-salt is determined from the blending ratio of the active agent.
Ask for TM. Next, the detergent composition was heated at pH 11 and at 50°C.
90% ethanol solution to separate the α-sulfofatty acid di-salt as an insoluble component. 50% of this di-salt
Dissolve in ethanol solution, determine the amount S of di-salt by methylene blue back titration method, and determine the hydrolysis rate D by the following formula. D=S/TM×100 By the above operation, the detergent composition is immediately prepared and
The hydrolysis rate after being left at 35°C for one month is determined, and the rate of increase in hydrolysis is calculated using the following formula. Hydrolysis increase rate = (hydrolysis rate after 1 month) -
(Hydrolysis rate immediately after production)

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Claims (1)

[Claims] 1 Powdered detergent containing α-sulfo fatty acid ester salt and 1wt% aqueous solution having a pH of 7 or lower: boric acid, organic carboxylic acid, organic oxycarboxylic acid, nitrilotriacetic acid, ethylenediaminetetraacetic acid, para-toluenesulfonic acid, aluminum sulfate, sulfuric acid A granular detergent composition characterized in that one or more selected from hydrogen, hydrogen sulfite, and salts thereof are mixed in powder form.