JPH0651877B2 - Polymer Electrolyte Builder - Google Patents

Description

TECHNICAL FIELD The present invention relates to a water-soluble polyelectrolyte builder that can substitute for a phosphate. Conventionally, phosphate, especially tripolyphosphate, has been widely used as a builder for detergents,
From the standpoint of water quality conservation, it became clear that it could cause water quality eutrophication, which was a serious problem.

Therefore, there has been a strong demand for the development of builders that can substitute for phosphates.

The present invention provides a water-soluble polymer builder that overcomes such drawbacks of eutrophication of water quality and can substitute for phosphate.

[Conventional technology]

Phosphate is water-soluble as a builder for detergents,
It has several excellent properties such as the ability to sequester polyvalent metal ions in hard water, the ability to clean solid particle dirt, and the ability to prevent dirt particles from reattaching to cloth.

On the other hand, in recent years, it has been proposed and used to use synthetic zeolite as a builder as an inorganic builder, but unlike phosphates, these are only water-insoluble particles, and the phosphate builder has It is hard to say that it is complete with characteristics.

In particular, it has been revealed that the synthetic zeolite builder is inferior to the above-mentioned excellent performance of the phosphate builder in the cleaning power for dirt of solid particles and the ability of preventing dirt particles from reattaching to cloth. .

On the other hand, various organic builders have also been proposed. For example, U.S. Pat. No. 3,308,067 describes that the disadvantage of the alkali metal salt of polycarboxylic acid on the water quality of the above-mentioned tripolyphosphate can be eliminated, and the cheapest sodium salt of polymaleic acid is useful among them. . However, since the sodium salt of polymaleic acid has insufficient solubility in cold water, its usefulness is limited, and it cannot be said to be satisfactory.

The present invention eliminates the eutrophication drawbacks of phosphate builders and has the ability to clean solid particle soils comparable to that of phosphate builders, as well as the excellent redeposition of solid particle soils on cloth. It is an object of the present invention to provide a water-soluble polyelectrolyte builder having some properties such as good prevention ability and good solubility in cold water.

[Problems to be solved by the invention]

As described above, the conventionally used phosphate builders have an excellent ability to sequester polyvalent metal ions and, at the same time, an excellent detergency against stains on solid particles.

As a method of compensating for the decrease in detergency associated with the conversion from detergents containing phosphate builders to detergents not containing these, it has been proposed to incorporate synthetic zeolite, but with regard to washing solid particle dirt Is not a satisfactory solution.

The present inventors have paid attention to such problems, and have excellent polyvalent metal ion sequestering ability to the extent that they can be replaced by phosphate builders and excellent detergency for solid particle stains, and their ability to prevent redeposition of soiled solid particles on cloth. The present invention has been achieved through repeated research to develop a water-soluble builder having

An object of the present invention is to provide a water-soluble builder having the excellent polyvalent metal ion sequestering ability of conventional phosphate builders, the excellent detergency for solid particle stains, and the ability to prevent redeposition of soil solid particles on cloth. Especially.

[Means for solving problems]

The present inventors have conducted extensive studies to achieve the above-mentioned object, and as a result, a homopolymer of styrene sulfonate or a styrene sulfonate and an ethylenically unsaturated monomer having a carboxylic acid group and / or a carboxylic acid group. It was found that the problem can be solved at once by using a water-soluble polymer electrolyte composed of a copolymer of an ethylenically unsaturated monomer having an acid group and a hydroxyl group as a builder, and the present invention based on this finding Has been completed.

That is, the present invention is a homopolymer of styrene sulfonate or an ethylenically unsaturated monomer having styrene sulfonate and a carboxylic acid group and / or an ethylenically unsaturated monomer having a carboxylic acid group and a hydroxyl group. The present invention provides a water-soluble polymer electrolyte composed of a copolymer with

It is known that the water-soluble polyelectrolyte in such a range has a characteristic behavior in terms of performance as a builder depending on the constitution of the monomer. For example, styrene sulfonate has the solubility of polymer chains in water and the ability to prevent redeposition of soiled solid particles on cloth. It has the ability to prevent redeposition on cloth, and the hydroxyl group has the ability to dissolve the polymer chain in water and the ability to prevent redeposition of soiled solid particles on cloth.
Therefore, the constitution of these components is an important factor, particularly the water-soluble electrolyte of a copolymer of styrene sulfonic acid and an ethylenically unsaturated monomer having a carboxylic acid group and ethylene having a styrene sulfonic acid and a carboxylic acid group. A water-soluble electrolyte of a copolymer of a polyunsaturated monomer, an ethylenically unsaturated monomer having a carboxylic acid group and a hydroxyl group exhibits preferable performance.

The water-soluble polyelectrolyte builder of the present invention can be produced by various methods, but generally, it can be produced by polymerizing these constituent monomers in water or another solvent.

The object of the present invention is a homopolymer of styrene sulfonate, or an ethylenically unsaturated monomer having styrene sulfonate and a carboxylic acid group and / or an ethylenically unsaturated monomer having a carboxylic acid group and a hydroxyl group. It can be basically achieved by a water-soluble polyelectrolyte of a copolymer with the body.

Examples of the ethylenically unsaturated monomer having a carboxylic acid group include acrylic acid, methacrylic acid, itaconic acid and fumaric acid, and one or two of these can be used. Examples of the ethylenically unsaturated monomer having a carboxyl group and a hydroxyl group include hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, triethylene glycol monoacrylate and triethylene. Glycol monomethacrylate, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, etc. can be mentioned.
More than one species can be used.

The water-soluble polyelectrolyte of the present invention is a styrene sulfonate alone or an ethylenically unsaturated monomer having a styrene sulfonate and a carboxylic acid group and / or an ethylenically unsaturated monomer having a carboxylic acid group and a hydroxyl group. by polymerizing the dimer in water, KOH, NaOH, 4 to 12, preferably a pH of the aqueous solution with an aqueous solution of NH ₄ OH or amines pH7.5~1
It can be manufactured by adjusting the range to 1.0.

The copolymerization ratio of styrene sulfonate in the polymer is preferably 3 mol% or more of the monomer of styrene sulfonate in the polymer, and particularly preferably 5 mol% or more in the polymer. .

The composition ratio of such a sulfonate exerts the effects of imparting water solubility as a builder and preventing dirt solid particles from reattaching to the cloth.

The copolymerization ratio of carboxylic acid groups in the polymer is preferably 20 mol% or more of carboxylate units in the polymer,
It is particularly preferably 30 mol% or more and 90 mol% or less in the polymer.

Depending on the composition ratio of the carboxylic acid group, effects such as polyvalent metal ion sequestering ability and cleaning power for dirt on solid particles are exhibited.

Polymerization of the water-soluble polyelectrolyte of the present invention, these ethylenically unsaturated monomers in water in the usual radical polymerization initiator, for example, potassium persulfate, persulfates such as ammonium persulfate, or cumene hydroperoxide, A conventional polymerization method may be used in which each component is introduced together or partially or continuously with an organic peroxide such as t-butyl hydroperoxide into a polymerization vessel while stirring under a nitrogen atmosphere and polymerization is performed.

A method in which each component is continuously introduced is preferable for reasons such as removal of heat of polymerization reaction. The polymerization temperature is 40 ° C to 100
℃ is good.

The molecular weight of the water-soluble polymer obtained by such a polymerization method depends on the concentration of the monomer present in the polymerization system, the amount of the polymerization initiator used, the polymerization temperature and the like.

The concentration of the monomer can be freely selected, but generally 5 to 5
It is carried out at 0 wt%, usually 10 to 30 wt%. Polymerization at a high concentration of the monomer is not preferable because the viscosity in the polymerization system becomes high and it becomes difficult to remove the heat of polymerization reaction. Also, polymerization at a too low concentration is not preferable because it is economically disadvantageous.

When the amount of radical polymerization initiator used for polymerization is large, the molecular weight of the water-soluble polymer electrolyte tends to be small, and when the amount of radical polymerization initiator is small, the molecular weight of the water-soluble polymer electrolyte is large. Shows a tendency to become.

Usually, the amount of radical polymerization initiator used is 0.
It is used within the range of 01 wt% to 10 wt%.

The method for obtaining the water-soluble polymer electrolyte in the present invention is not limited to such a method.

[Action]

With respect to the water-soluble polyelectrolyte of the present invention, it is not clarified what action mechanism the builder effect is.

However, a homopolymer of styrene sulfonate or a water-soluble polymer composed of a monomer unit having a styrene sulfonate and a carboxylic acid group and / or a monomer unit having a carboxylic acid group and a hydroxyl group, It is considered that they interact with each other such as polyvalent metal ion sequestering ability, detergency of solid particle dirt, ability to prevent dirt solid particles from redepositing on cloth, and solubility in water.

Furthermore, it is considered that the polymer has extremely advantageous properties as a builder, such as being highly safe for biological systems and having high stability.

〔The invention's effect〕

Among the various effects of using the polyelectrolyte builder of the present invention, the notable points are the detergency of solid particle stains and the effect of preventing redeposition of soiled solid particles on cloth, compared with sodium tripolyphosphate. Is also excellent at low concentrations.

Furthermore, the ability to prevent redeposition of such solid particle stains on the cloth,
It can be said that the polyelectrolyte builder of the present invention is a water-soluble builder having performance comparable to or higher than sodium tripolyphosphate conventionally used in the mainstream, such as cleaning effect in a low concentration range.

As described above, synthetic zeolite builders have recently been in the limelight for the purpose of substituting phosphates, but the fact is that they are not satisfactory in terms of performance.

Since the polyelectrolyte builder of the present invention is water-soluble, it can be said that it is a novel builder that can replace them.

〔Example〕

Hereinafter, the present invention will be described more specifically with reference to Examples, but the scope of the present invention is not limited by the description of these Examples.

Synthesis Example 1 Sodium styrenesulfonate (trade name: Spinomer NaS
S, manufactured by Toyo Soda Kogyo Co., Ltd.) was polymerized at 90 ° C. in the presence of ammonium persulfate to give a weight average molecular weight of 5.5 ×.
20% by weight of 10 ⁴ sodium styrenesulfonate polymer
An aqueous solution was obtained. The pH of the aqueous solution was 8.5. The amount of unreacted sodium styrenesulfonate by the bromine addition method is
It was a trace, and the polymerization rate was measured to be 99% or more.

Synthesis Example 2 Sodium styrenesulfonate (trade name: Spinomer NaS
S, manufactured by Toyo Soda Kogyo Co., Ltd.) was mixed at 90 ° C. in the presence of ammonium persulfate to prepare an aqueous solution of sodium styrenesulfonate = methacrylic acid copolymer having a weight average molecular weight of 3 × 10 ^4. Obtained.

Unreacted methacrylic acid was measured by gas chromatography to determine the polymerization rate of methacrylic acid, which was confirmed to be 99% or more. In addition, elemental analysis of the polymer revealed that it contained 18 mol% of sodium styrenesulfonate unit based on the amount of sulfur contained.

Using a 10% sodium hydroxide aqueous solution, a 20 wt% aqueous solution of sodium styrenesulfonate = sodium methacrylate copolymer having a pH of 8.0 was obtained.

Synthesis Example 3 Sodium styrenesulfonate (trade name: Spinomer NaS
S, manufactured by Toyo Soda Kogyo Co., Ltd.), an aqueous solution of a monomer mixture of acrylic acid and 2-hydroxyethyl methacrylate is polymerized at 90 ° C. in the presence of ammonium persulfate to give a styrenesulfonic acid having a weight average molecular weight of 3 × 10 ^4. Sodium =
Acrylic acid = 2-hydroxyethyl methacrylate copolymer was obtained.

Unreacted acrylic acid and 2-hydroxyethyl methacrylate were measured by gas chromatography to determine the polymerization rate of each monomer, but it was confirmed that each was 99% or more.

From the content of sulfur by elemental analysis of the polymer, the copolymer composition of sodium styrenesulfonate = acrylic acid = 2-hydroxyethylmethacrylate was 12.5 mol%,
The calculated values were 23.5 mol% and 64 mol%.

〔Test method〕

(1) Method for measuring calcium ion sequestering ability The calcium ion sequestering ability of the builder was measured using a calcium ion selective electrode at pH 10 and 30 ° C.

It was evaluated by the reduction of the free calcium ion concentration in the system by the builder added to hard water having a hardness of 100 ppm.

(2) Measurement of agglomeration of solid particle dirt in water Iron oxide particles (average particle size 0.2 × 10 ^-4 cm Toda Color 120R manufactured by Toda Kogyo Co., Ltd.) were selected as a model of solid particle dirt, and iron oxide particles in water were selected. The average particle size was determined from the volume-based particle size distribution by using a centrifugal automatic particle size distribution analyzer CAPA-500 type (Horiba Seisakusho).

(3) Preparation of solid particle-contaminated cloth, adhesion test method for solid particle dirt, and cleaning test conditions Iron oxide particles were selected as solid particles to prepare a contaminated cloth. Contamination cloth is white cloth (10g) in iron oxide water dispersion cloth (0.2g /).
20 cm x 10 cm cloth) and put it on a vertical shaker for 30
It was prepared by contaminated for a minute. (Average reflectance: 21.3%) Also, the soil adhesion to the cloth and the washing experiment are performed by the Terg-O-Tometer.
Was used under the condition of inversion number of 60 cpm. In the case of adhesion test, 5 sheets of 10 cm x 10 cm white cloth are put in 500 ml of the liquid under the specified conditions. In case of washing experiment, 30 pieces of white cloth are put on each of the soiled cloth and the white cloth for checking recontamination from the washing bath. ℃
For 10 minutes, and then rinsed for 3 minutes. For contamination, 0.1 g of iron oxide was dispersed by ultrasonic irradiation, and the volumetric flask was placed in a thermostat at 30 ° C for 24 hours.
The liquid left standing for a time was used.

The amount of iron oxide deposited on the cloth was measured by ashing the test cloth in a muffle furnace (600 ° C., 6 hours), dissolving it in a 1: 1 hydrochloric acid aqueous solution, and measuring it by an atomic absorption method.

Example 1 The calcium ion sequestering ability was measured using the polymers produced in Synthesis Examples 1 to 3. Table 1 shows the calcium ion sequestering ability of the water-soluble polymer builder of the present invention.

Among the polymers, the polymer of the present invention of Synthesis Example 2 shows a good ion sequestering ability.

Example 2 Using the polymers produced in Synthesis Examples 1 to 3, the average aggregate particle size of iron oxide particles was measured in water.

The results are shown in Table-2, and it is clear that the polymer electrolyte builders of the present invention of Synthesis Examples 1 to 3 can stably disperse iron oxide particles, which are a model of solid particles of soil, as fine particles.

The polyelectrolyte builder of the present invention is particularly excellent in the dispersibility of solid particle stains in water in the low concentration range of the builder.

Example 3 The amount of iron oxide particles attached to a cloth was measured using the polymers produced in Synthesis Examples 1 to 3. The results are shown in Table-3.

The addition of the polyelectrolyte builder of the present invention significantly reduced the amount of iron oxide deposited on the cloth.

Example 4 Using the polyelectrolyte builder of the invention of Synthesis Example 2,
The iron oxide-contaminated cloth was washed, and the iron oxide adhering to the cloth before and after washing was analyzed to examine the cleaning rate.

It is shown that the polyelectrolyte builder of the present invention has a higher cleaning rate in the low concentration region as compared with sodium tripolyphosphate which is a phosphate builder. The results are shown in Figure 1.

Further, white cloth was put in the washing bath of this example, and the redeposition phenomenon of the white cloth was examined. The polymer electrolyte builder of the present invention showed an excellent anti-redeposition effect at any builder concentration. The results are shown in Figure 2.

(All of the above tests were carried out under the conditions of Fe ₂ O ₃ 50 ppm, pH 10 and 30 ° C.)

[Brief description of drawings]

Figure 1 and Figure 2 show the amount of builder added and redeposited Fe ₂ O, respectively.
₃ shows the relationship between the amount and the cleaning rate.

Claims (3)

[Claims] 1. A homopolymer of styrene sulfonate, or an ethylenically unsaturated monomer having styrene sulfonate and a carboxylic acid group and / or an ethylenically unsaturated monomer having a carboxylic acid group and a hydroxyl group. Water-soluble polyelectrolyte builder consisting of a copolymer with 2. The ethylenically unsaturated monomer having a carboxylic acid group is one or more monomers selected from methacrylic acid, acrylic acid, itaconic acid, fumaric acid and salts thereof. The water-soluble polyelectrolyte builder according to claim 1. 3. An ethylenically unsaturated monomer having a carboxylic acid group and a hydroxyl group is hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, triethylene glycol mono. The water-soluble polyelectrolyte builder according to claim 1, which is one or more monomers selected from acrylate, triethylene glycol monomethacrylate, polyethylene glycol monoacrylate, and polyethylene glycol monomethacrylate.