JP2918798B2 - Water-soluble graft polymer, its production method and use - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for grafting an ethylenically unsaturated dicarboxylic acid such as (meth) acrylic acid and maleic acid onto a polyether containing ethylene oxide as a main component at a high graft ratio, in other words, onto a polyether. The present invention relates to a method for producing a water-soluble graft polymer having a small amount of unpolymerized monomer and excellent gel resistance.

[0002] The present invention also relates to a water-soluble graft polymer obtained by grafting (meth) acrylic acid and an ethylenically unsaturated dicarboxylic acid to a polyether compound and having a gel resistance of 0.16 or less.

[0003] Further, the present invention relates to a detergent composition containing the water-soluble graft polymer.

[0004]

2. Description of the Related Art Attempts to graft polymerize (meth) acrylic acid to polyether compounds have been made in various fields of application such as polyurethane. For example, JP
JP-A-5-71710 discloses a polymer obtained by graft-polymerizing acrylic acid to a polyoxyalkylene compound in an amount of 3 to 15% by weight based on the total charged amount, and a method for producing the polymer.
However, in this case, when the obtained graft polymer is used as a dispersant such as a builder or an inorganic pigment, there is a problem that the gel resistance is poor.

Further, when a hydrophilic ethylenically unsaturated monomer is graft-polymerized in an amount of 25% by weight or more with respect to the total charged amount, the carboxylic acid density is too high, and the gel resistance is poor when used for the above purpose. There's a problem.

JP-A-59-62614 discloses that at least 20% by weight of a polyglycol ether having at least one hydrophobic group is added to a graft polymer.
In the graft polymer obtained by graft polymerization of the above hydrophilic ethylenically unsaturated monomer and a method for producing the same, a method using a solvent of water or toluene, or a method in which the reaction temperature is 90 ° C. or lower even without a solvent is disclosed. I have. The graft efficiency of the graft polymer obtained by this method is low, and there are many ungrafted polymers. When this graft polymer is used as a builder or a dispersant such as an inorganic pigment, satisfactory performance cannot be obtained, and when used as a builder for a liquid detergent, there is a problem that the polymer is separated.

Further, Japanese Patent Application Laid-Open No. 3-177406 discloses a similar graft polymer obtained by polymerization in an aqueous solvent. However, the disclosed polymerization method for graft polymerization in an aqueous solvent has poor grafting efficiency, and many of the resulting polymers are ungrafted polycarboxylic acids. There is a problem that the intended performance cannot be obtained very badly.

As described above, according to the conventional technique, a graft polymer having high graft efficiency and good gel resistance cannot be easily produced.

[0009]

According to the present invention, an ethylenically unsaturated dicarboxylic acid such as (meth) acrylic acid or maleic acid is grafted onto a polyether having a high graft ratio.
It is another object of the present invention to provide a method for producing a water-soluble graft polymer having good gel resistance.

Another object of the present invention is to provide a water-soluble graft polymer obtained by grafting (meth) acrylic acid and an ethylenically unsaturated dicarboxylic acid to a polyether compound and having a gel resistance of 0.16 or less. Make it an issue.

[0011]

Means for Solving the Problems The present inventors have intensively studied a method for producing a water-soluble graft polymer which has improved the above problems, has less non-grafted polymer, and has improved gel resistance. As a result, the present invention has been completed.

According to the present invention, 50 mol of ethylene oxide is used.
A polyether compound (A) having a number average molecular weight of 200 or more having 1% or more as a constitutional unit is composed of 40 to 90 mol% of (meth) acrylic acid (b1) and 10 to 60 mol% of an ethylenically unsaturated dicarboxylic acid (b2). When the monomer component (B) is graft-polymerized in an amount of 5% by weight or more and less than 25% by weight with respect to the polyether compound (A) to obtain a water-soluble graft polymer, the polyether compound (A) The monomer component (B) is mixed with the polyether compound (A) in advance in the presence of a polymerization initiator substantially without using a solvent, and at least half of (b2) is mixed with the polyether compound (A). (B) and a polymerization initiator, and a graft polymerization reaction is performed at a temperature of 120 ° C. or higher.

The present invention is also a water-soluble graft polymer obtained by grafting (meth) acrylic acid and an ethylenically unsaturated dicarboxylic acid to a polyether compound and having a gel resistance of 0.16 or less.

The polyether compound (A) used in the present invention has a number average molecular weight of 200 or more having ethylene oxide as a constituent unit in an amount of 50 mol% or more. Ethylene oxide and other alkylene oxides are dissolved in water or alcohol. It is obtained by polymerizing in a known manner as a starting point.

Examples of the alcohol for obtaining the polyether include primary alcohols having 1 to 22 carbon atoms such as methanol, ethanol, n-propanol and n-butanol; secondary alcohols having 3 to 18 carbon atoms; t-butanol Tertiary alcohols such as ethylene glycol, diethylene glycol, propanediol, butanediol and propylene glycol; diols such as glycerin and trimethylolpropane; and polyols such as sorbitol.

The other alkylene oxide copolymerizable with ethylene oxide is not particularly limited, but propylene oxide and butylene oxide are preferred. Further, the content of other alkylene oxides copolymerizable with ethylene oxide must be less than 50 mol% as a whole. When the content is 50 mol% or more, the graft ratio of the obtained graft polymer decreases. Further, as the polyether compound (A), the hydroxyl groups at all or some of the terminals of the polyether obtained as described above may be substituted with fatty acids having 2 to 22 carbon atoms, succinic acid, succinic anhydride, and maleic acid. And those esterified with dicarboxylic acids such as maleic anhydride and adipic acid.

The molecular weight of these polyethers is 2
00 or more. When the molecular weight is smaller than 200, there is a problem that the amount of ungrafted polyether increases. If the molecular weight is as high as 20,000 or more, the gel resistance becomes poor. Therefore, the molecular weight is preferably 20,000 or less, more preferably 6,000 or less.

In the present invention, the polyether compound (A)
In addition, 40 to 90 mol% of (meth) acrylic acid (b1) and 10 to 60 m of ethylenically unsaturated dicarboxylic acid (b2)
ol% of the monomer component (B) must be graft-polymerized in an amount of 5% by weight or more and less than 25% by weight based on the polyether compound (A). When the amount is less than 5% by weight, the carboxylic acid density of the obtained graft polymer is too low, and various properties such as polyvalent metal ion chelating ability,
Performance such as dispersibility is not satisfied. On the other hand, if the content is 25% by weight or more, the carboxylic acid density is too high, and the gel resistance deteriorates.
The amount of the graft polymerization used for (A) in (B) is 7 to
23% by weight is more preferred and 10-20% by weight is most preferred.

The copolymerization ratio of (meth) acrylic acid (b1) and ethylenically unsaturated dicarboxylic acid (b2) is such that (b1) is 40
To 90 mol%, and (b2) to 10 to 60 mol%.
Here, when (b2) is less than 10 mol%, the molecular weight of the side chain portion of the graft polymer increases, and the gel resistance deteriorates. In other words, the ethylenically unsaturated dicarboxylic acid (b
By adding 2), the molecular weight of the side chain portion can be controlled, thereby improving the gel resistance. In addition, (meth) acrylic acid (b1)
If the amount is less than mol%, there is a problem that the rate of introduction of maleic acid (b2) into the graft polymer decreases and the amount of remaining monomer increases.

The graft polymerization is carried out in the presence of a polymerization initiator.
This is performed substantially without using a solvent. As the polymerization initiator, known radical initiators can be used,
Organic peroxides are particularly preferred.

Examples of the organic peroxide include ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide; t-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, p-menthane hydroperoxide, , 5-Dimethylhexane-2,5-dihydroperoxide, 1,1,3,3
Hydroperoxides such as -tetramethylbutyl hydroperoxide; di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, α, α'-bis (t-butylperoxy) p
Dialkyl peroxides such as -diisopropylbenzene, α, α'-bis (t-butylperoxy) p-diisopropylhexyne; t-butylperoxyacetate, t-butylperoxylaurate, t-butylperoxybenzoate Peroxyesters such as di-t-butylperoxyisophthalate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxyisopropylcarbonate; n-butyl-4,4 Peroxyketals such as -bis (t-butylperoxy) valeate and 2,2-bis (t-butylperoxy) butane; diacyl peroxides such as dibenzoyl peroxide;

The amount of the polymerization initiator is not particularly limited, but is preferably 0.1 to 15% by weight, more preferably 0.5 to 10% by weight, based on the monomer (B). If the amount is smaller or larger, the grafting efficiency of the monomer to the polyether decreases. Further, the polymerization initiator can be added to the polyether in advance, or can be added simultaneously with the monomer to be added.

The graft polymerization is carried out substantially without a solvent. When water or an organic solvent such as alcohol or toluene is used, the grafting efficiency of the monomer onto the polyether decreases. When a solvent is used for adding the initiator and the monomer, the amount is preferably as small as possible, preferably 5% by weight or less based on the total amount, or it is preferably immediately distilled off from the reaction system after the addition.

The polymerization temperature is 120 ° C. or higher, preferably 12 ° C.
It is performed at a temperature of 0 ° C or more and 160 ° C or less. When the temperature is lower than 120 ° C., the grafting efficiency of the monomer to the polyether decreases. At a temperature higher than 160 ° C., thermal decomposition of the polyether and the graft polymer may occur.

At the time of graft polymerization, it is preferable to initially charge a part or all of the polyether compound (A). Further, it is preferable to initially charge at least half of the amount of the ethylenically unsaturated dicarboxylic acid (b2) used together with the polyether compound (A). Then, the remaining monomer and the initiator are separately dropped after heating the polyether to 120 ° C. or higher. At this time, when a part of the polyether compound (A) is initially charged, the remaining polyether compound (A) can be mixed with an initiator or a monomer and dropped.

The obtained polymer can be used as it is as a dispersant or scale inhibitor by dissolving it in a solvent such as water or alcohol, or it can be used by adding a base. Examples of the base include a monovalent metal salt such as a sodium salt and a potassium salt, a divalent metal salt such as a calcium salt, a trivalent metal salt such as an aluminum salt, an ammonium salt, and an organic amine salt such as monoethanolamine and triethanolamine. Can be mentioned. In that case, water is preferable as the solvent.

The water-soluble graft polymer obtained by the production method of the present invention has an appropriate carboxylic acid density and an appropriate molecular weight, so that it is very excellent in dispersing solid particles. Also, since the graft rate is high and the gel resistance is good,
Even when mixed with liquid detergent, it becomes a homogeneous solution, precipitates,
Since no separation or the like occurs, it can be used as a detergent composition. Further, the detergent composition containing the water-soluble graft polymer obtained by the production method of the present invention has a water-soluble graft polymer content of 0.1%.
1% to 15%, and a surfactant and, if necessary, an enzyme can be compounded and used.

As the surfactant, anionic surfactants, nonionic surfactants, amphoteric surfactants and cationic surfactants can be used.

Examples of the anionic surfactant include alkyl benzene sulfonate, alkyl or alkenyl ether sulfate, alkyl or alkenyl sulfate,
α-olefin sulfonate, α-sulfo fatty acid or ester salt, alkane sulfonate, saturated or unsaturated fatty acid salt, alkyl or alkenyl ether carboxylate, amino acid type surfactant, N-acyl amino acid type surfactant, Examples thereof include an alkyl or alkenyl phosphate or a salt thereof.

Examples of the nonionic surfactant include polyoxyalkylene alkyl or alkenyl ether, polyoxyethylene alkyl phenyl ether, higher fatty acid alkanolamide or an alkylene oxide adduct thereof, sucrose fatty acid ester, alkyl glycooxide, and fatty acid glycerin monoester. Examples thereof include esters and alkylamine oxides.

Examples of the amphoteric surfactant include a carboxy type or sulfobetaine type amphoteric surfactant, and examples of the cationic surfactant include a quaternary ammonium salt.

The content of these surfactants is from 5 to 70
% By weight, and more preferably 20 to 60% by weight. However, when a nonionic surfactant is used, the concentration of the nonionic surfactant is preferably 50% by weight or more, more preferably 60% by weight or more for the purpose of compacting the detergent and improving the detergency. , 70
% Or more is most preferred.

As the enzyme to be incorporated in the detergent composition containing the water-soluble graft polymer obtained by the production method of the present invention, protease, lipase, cellulase and the like can be used. Particularly, protease, alkaline lipase, alkaline cellulase and the like having high activity in an alkaline washing solution are preferable. The amount of the enzyme is 0.01 to 5% by weight.
Is preferred. If the ratio is out of this range, the balance with the surfactant is lost, and the cleaning power cannot be improved.

The detergent composition containing the water-soluble graft polymer obtained by the production method of the present invention may contain a known alkali builder, chelate builder, anti-redeposition agent, fluorescent agent, bleaching agent, fragrance, etc., if necessary. The components commonly used in the above detergent composition may be blended. Further, zeolite may be blended. Silicates, carbonates, sulfates and the like can be used as the alkali builder. Chelate builders include diglycolic acid, oxycarboxylate, EDTA
(Ethylenediaminetetraacetic acid), DTPA (diethylenetriaminehexaacetic acid), citric acid and the like can be used as needed.

Further, the water-soluble graft polymer obtained by the production method of the present invention exhibits good performance as an inorganic or organic dispersant having poor solubility in water. For example,
It exhibits good performance as a dispersant for inorganic pigments such as heavy or light calcium carbonate and clay used for paper coating and as a dispersant for water slurries such as cement and coal.
In addition, it is also used for cooling water system, boiler water system, seawater desalination equipment, water treatment agent for scale prevention in pulp digester, black liquor concentration kettle, fiber treatment agent such as dyeing assistant and fiber antistatic assistant. can do.

Further, the water-soluble graft polymer obtained by the production method of the present invention can be used as a water-absorbing resin by crosslinking with a crosslinking agent. Since the water-soluble graft polymer obtained by the production method of the present invention has a high grafting ratio, the water-absorbent resin obtained by crosslinking with a crosslinking agent has a low soluble content, and also contains a polyether in its main chain, so that it has salt resistance. Water-absorbent resin having a high water content is obtained. The crosslinking is carried out by a known method and is not particularly limited, but is preferably carried out by a reaction between a carboxylic acid of the graft polymer and a crosslinking agent.

[0037]

【Example】

(Example 1) 100 parts by weight of monomethoxypolyethylene glycol having an average molecular weight of 1100 and 10 parts by weight of maleic acid were charged into a glass reactor equipped with a thermometer, a stirrer, a nitrogen inlet tube, and a reflux condenser, and the mixture was placed under a nitrogen stream. The mixture was heated and melt-mixed, and the temperature was raised to 145 ° C. with stirring. Next, while keeping the temperature at 145 to 147 ° C., 13 parts by weight of acrylic acid and 1.2 parts by weight of di-t-butyl peroxide were separately dropped continuously over 2 hours, and then stirring was continued for 30 minutes. Was. After cooling, aqueous sodium hydroxide solution (48
% Solution) with stirring to obtain a pH of 7.5 to obtain an aqueous sodium salt solution of the graft polymer 1.

(Example 2) Monomethoxy polyethylene glycol 100 having an average molecular weight of 1100 was placed in a glass reactor equipped with a thermometer, a stirrer, a nitrogen introducing tube, and a reflux condenser.
Parts by weight, and 7 parts by weight of maleic acid.
The mixture was melted by heating and heated to 145 ° C. with stirring. Next, while maintaining the temperature at 145 to 147 ° C., 10 parts by weight of acrylic acid and 0.1% of di-t-butyl peroxide were added.
9 parts by weight separately and continuously dropped over 2 hours,
Thereafter, stirring was continued for 30 minutes. After cooling, an aqueous sodium hydroxide solution (48% solution) was added to the mixture so as to have a pH of 7.5 while stirring to obtain an aqueous sodium salt solution of the graft polymer 2.

Comparative Example 1 100 parts by weight of polyethylene glycol having an average molecular weight of 1100 was charged into a glass reactor equipped with a thermometer, a stirrer, a nitrogen inlet tube, and a reflux condenser, and heated and melted under a nitrogen stream. 145 under stirring
The temperature was raised to ° C. Next, while maintaining the temperature at 145 to 147 ° C., 23 parts by weight of acrylic acid and 1.2 parts by weight of di-t-butyl peroxide were separately dropped continuously over 2 hours, and then stirring was continued for 30 minutes. Was. After cooling, an aqueous sodium hydroxide solution (48% solution) was added to adjust the pH to 7.0.
The solution was neutralized to 5 to obtain an aqueous sodium salt solution of comparative graft polymer 1.

Comparative Example 2 Monomethoxy polyethylene glycol having an average molecular weight of 1100 was placed in a glass reactor equipped with a thermometer, a stirrer, a nitrogen inlet tube, and a reflux condenser.
Parts by weight and 14.6 parts by weight of maleic acid were charged, heated and melt-mixed in a nitrogen stream, and heated to 145 ° C. with stirring. Next, while keeping the temperature at 145 to 147 ° C,
Acrylic acid (19.7 parts by weight) and di-t-butyl peroxide (1.2 parts by weight) were separately added dropwise continuously over 2 hours, and then stirring was continued for 30 minutes. After cooling, a sodium hydroxide aqueous solution (48% solution) was
In addition, an aqueous solution of sodium salt of Comparative Graft Polymer 2 was obtained in an amount of 7.5.

(Comparative Example 3) Monomethoxy polyethylene glycol 100 having an average molecular weight of 2,000 was placed in a glass reactor equipped with a thermometer, a stirrer, a nitrogen inlet tube, and a reflux condenser.
Parts by weight and 20.4 parts by weight of maleic acid were charged and melted and mixed by heating under a nitrogen stream, and the temperature was raised to 145 ° C. with stirring. Next, while keeping the temperature at 145 to 147 ° C,
Acrylic acid (29.6 parts by weight) and di-t-butyl peroxide (2.5 parts by weight) were separately added dropwise continuously over 2 hours, and then stirring was continued for 30 minutes. After cooling, a sodium hydroxide aqueous solution (48% solution) was
In addition, an aqueous solution of sodium salt of Comparative Graft Polymer 3 was obtained.

Example 3 Examples 1 and 2 and Comparative Examples 1 and 2
Gel resistance tests of the graft polymers obtained in 2 and 3 were performed by the following measurement methods, and the results are summarized in Table 1.

Measurement method Zinc nitrate hexahydrate 10g, calcium chloride dihydrate 10
g, 10 g of an aqueous sodium salt solution (concentration: 25% by weight) of the graft polymer and 10 g of ion-exchanged water were added to prepare a total of 40 g of test solution.

2. The test solution was sealed and allowed to stand in a constant temperature bath at 80 ° C. for 30 minutes, and the absorbance was measured at a UV wavelength of 380 nm with a 1 cm quartz cell using a Shimadzu spectrophotometer.

3. The obtained value was used as the gel resistance.

That is, the smaller the value of the degree of gelation, the better the gel resistance, and preferably 0.5 or less, more preferably 0.2 or less.

Example 4 Examples 1 and 2 and Comparative Examples 1 and 2
In order to evaluate the performance as a detergent composition of the graft polymer obtained in 2, 3, the following detergency test was performed. The results are shown in Table 5.

Test Method 1. The artificial soil of the components shown in Table 2 was dispersed in carbon tetrachloride to prepare an artificial soil solution, and a cotton white cloth was passed through the artificial soil solution, dried and cut to obtain 10 cm × 1
A 0 cm soiled cloth was made.

2. Using the detergent compositions shown in Table 3, the stained cloth was washed under the washing conditions shown in Table 4, and after drying the stained cloth, the reflectance was measured.

3. The cleaning rate was determined from the following equation.

Cleaning rate = (Reflectance after cleaning−Reflectance before cleaning) / (Reflectance of white cloth−Reflectance before cleaning) × 100 (Example 5) Examples 1 and 2 and Comparative Examples 1 and 2 In order to evaluate the performance of the obtained graft polymer as a detergent composition, the following detergency test was conducted. The results are shown in Table 9.

Test Method 1. The artificial soil of the components shown in Table 6 was dispersed in carbon tetrachloride to prepare an artificial soil solution, and a cotton white cloth was passed through the artificial soil solution, dried and cut to obtain 10 cm × 1
A 0 cm soiled cloth was made.

2. Using the detergent composition shown in Table 7, the stained cloth was washed under the washing conditions shown in Table 8, and after drying the stained cloth, the reflectance was measured.

3. The cleaning rate was determined from the following equation.

Washing rate = (Reflectance after washing−Reflectance before washing) / (Reflectance of white cloth−Reflectance before washing) × 100

[0056]

[Table 1]

[0057]

[Table 2]

[0058]

[Table 3]

[0059]

[Table 4]

[0060]

[Table 5]

[0061]

[Table 6]

[0062]

[Table 7]

[0063]

[Table 8]

[0064]

[Table 9]

[0065]

The water-soluble graft polymer obtained by the present invention is obtained by reacting (meth) acrylic acid (A) with a polyether compound (A) having a number average molecular weight of 200 or more and having ethylene oxide as a constituent unit in an amount of 50 mol% or more. b1) 40-9
0 mol% and ethylenically unsaturated dicarboxylic acid (b2)
By graft-polymerizing the monomer component (B) composed of 10 to 60 mol% in an amount of 5% by weight or more and less than 25% by weight,
It can be said that the gel composition has excellent gel resistance and excellent performance as a detergent composition.

Therefore, in the present invention, the gelation resistance is improved by setting the charged amount of the monomer to be grafted to a specific range, and further including an ethylenically unsaturated dicarboxylic acid in a monomer component of 10 mol% or more. In addition, a water-soluble graft polymer having greatly improved detergency has been found.

Continuing from the front page (72) Inventor Hideyuki Nishibayashi 992, Nishioki, Okihama-shi, Aboshi-ku, Himeji-shi, Hyogo Pref. 7-53645 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) C08F 283/06

Claims (5)

(57) [Claims] 1. A composition comprising at least 50 mol% of ethylene oxide.
The polyether compound (A) having a structural unit has (meth)
(T) 40-90 mol% of acrylic acid (b1) and ethyl
Unsaturated dicarboxylic acid (b2) from 10 to 60 mol%
To the polyether compound (A)
And graft at a ratio of 5% by weight or more and less than 25% by weight.
A water-soluble graft polymer having a gel resistance of 0.16 or less. 2. A polyether compound (A) having a number average molecular weight of 200 or more and having ethylene oxide as a constituent unit in an amount of 50 mol% or more is added with (meth) acrylic acid (b1) 40
Graft polymerization of a monomer component (B) consisting of from 90 to 90 mol% and an ethylenically unsaturated dicarboxylic acid (b2) from 10 to 60 mol% with respect to the polyether compound (A) in an amount of 5% by weight or more and less than 25% by weight. To obtain a water-soluble graft polymer, the monomer component (B) is added to the polyether compound (A) in the presence of a polymerization initiator without substantially using a solvent, and the monomer component (b2) A water-soluble graft, wherein at least half of the amount used is mixed in advance with a polyether compound, and the remaining monomer component (B) and a polymerization initiator are added, followed by a graft polymerization reaction at a temperature of 120 ° C. or more. A method for producing a polymer. 3. A detergent composition comprising the water-soluble graft polymer according to claim 1 and a surfactant. 4. A detergent composition comprising a water-soluble graft polymer obtained by the production method according to claim 2 and a surfactant. 5. A detergent composition comprising 0.1% to 15% of a water-soluble graft polymer obtained by the production method according to claim 2, and 50% or more of a nonionic surfactant.