CN102718306A - Organic copolymerized amphoteric polymeric flocculant and preparation method thereof - Google Patents

Abstract

The invention discloses an organic copolymerized amphoteric polymer flocculant and a preparation method thereof. The amphoteric polymer flocculant is composed of dimethyl diallyl ammonium halide, acrylic acid-N,N-dimethylaminoethyl ester and sorbic acid (Salt) Copolymer formed by copolymerization of three monomers and diacrylate monomer of bifunctional group. Redox initiators, inorganic peroxide initiators and polymerization aids are used simultaneously in the preparation process, which improves the conversion rate of monomers and reduces residual monomers; the preparation of flocculants is simple and can be used directly; the prepared flocculants It has the advantages of small dosage, large floc diameter and fast settlement.

Description

A kind of organic copolymerized amphoteric macromolecule flocculant and its preparation method

technical field

The invention relates to an organic copolymerized amphoteric polymer flocculant and a preparation method.

Background technique

Water is the basic material for human survival and social development. At present, the water environment in the world is facing the problems of water resource shortage, excessive consumption and serious pollution. The World Health Organization (WHO) survey shows that 80% of human diseases are related to unsafe water quality. China is a country with abundant water resources, but at the same time it is a country with severe water shortage, extremely low utilization rate of water resources and serious water pollution. These three factors seriously restrict people's normal life and sustainable economic development. Therefore, effective treatment and reuse of waste water (sewage) is an inevitable way to solve limited water resources to meet people's growing production and living needs. In the process of waste (sewage) treatment and sludge dehydration, flocculation is an important, effective, economical and convenient method. The proportion of domestic and foreign industrial wastewater and domestic sewage treated by flocculation technology is 55% to 85%. 100% of industrial and sludge dehydration is treated by flocculation; the effect of waste (sewage) water flocculation and sludge dehydration is closely related to the operation of subsequent processes, the discharge of effluent and the cost of treatment, and the flocculant is waste (sewage) water One of the key factors for water treatment and solid-liquid separation, so the research and development of new, non-toxic and efficient flocculants is the focus and direction of water treatment.

Flocculants can be divided into several categories such as microbial flocculants, inorganic flocculants and organic polymer flocculants. Microbial flocculants are relatively safe for the environment and human beings. At present, most microbial flocculants are still in the screening stage of strains, and the cost is high, which cannot meet the requirements of industrial production and application. Due to the large amount of inorganic flocculants, the generation of a lot of sludge, strong corrosion, secondary pollution and the influence of waste (sewage) water quality, the water purification effect is not ideal in some occasions, and the application is greatly limited, and is gradually being used. Organic flocculants instead. Organic polymer flocculant has the advantages of less dosage, fast flocculation speed, less sludge generation, good decolorization and little impact on waste (sewage) water quality, etc. It is divided into natural organic polymer flocculants and synthetic organic polymer flocculants; the advantages of natural organic polymer flocculants are rich sources of raw materials, low price, basically non-toxic, easy biochemical degradation and basically no secondary pollution, and the disadvantage is that the composition is complex , Unstable composition, large performance fluctuations, possible deterioration during storage, and the use of a large amount of organic solvents in the production process, which limit its practical application; the synthetic organic polymer flocculant has stable performance, and the molecular weight of the synthetic product can be controlled according to needs And structure and other advantages, can be divided into non-ionic, anionic, cationic and amphoteric. With the development of society and economy, the discharge of modern industrial and domestic sewage and the increase of chemical oxygen demand (Chemical Oxygen Demand, CODcr), the composition and properties of waste (sewage) water have become increasingly complex, and it is difficult to use conventional flocculants Meet the requirements, but the surface of particles in waste (sewage) water is usually negatively charged, and the water contains a certain amount of toxic metal ions, the use of non-ionic, anionic and cationic polymer flocculants is limited; amphoteric organic polymers The polymer molecular chain of the flocculant contains both positive and negative charge groups, called amphoteric polymer or amphoteric polyelectrolyte, which has some characteristics due to its special molecular structure, such as electrical neutralization, Adsorption bridging and intermolecular "entanglement" encapsulation, suitable for waste (sewage) water where anions and cations coexist, for dispersions, emulsions and various sludges stabilized by anionic surfactants or by cations Various stable colloidal dispersions have good flocculation and sludge dehydration effects, and can be used as water treatment flocculants, sludge dehydrating agents, adsorbents and metal ion chelating agents, etc.; The advantages of ion removal, wide range of pH requirements, and good salt resistance make amphoteric organic polymer flocculants have a wide range of applications, and have become a research hotspot at home and abroad.

At present, the synthetic amphoteric organic polymer flocculants developed at home and abroad are mainly modified by polyacrylamide (pAM), that is, by the chemical reaction of amide groups, such as Mannich reaction, hydrolysis or grafting reaction modification. , and polyacrylonitrile (pAN) as the polymer chain, amphoteric polyacrylonitrile-dicyandiamide (pAN-DCD) modified with dicyandiamide; "Organic Chemical Materials" [M], 1999 The third edition in January 2006, Chemical Industry Press, edited by Si Hang, introduced acrylamide (AM) and acrylonitrile (AN) as highly toxic chemicals; "Acrylamide Polymer" [M], April 2006 No. 1st edition, Chemical Industry Press, edited by Fang Daobin, etc., introduced the hazards of acrylamide to the human body and the environment, "There are three forms of exposure to acrylamide, oral, respiratory inhalation and skin contact. Acrylamide is distributed in body fluids after inhalation. Water is the most important pollutant. Non-occupational exposure to acrylamide mainly comes from drinking water and food contaminated with acrylamide. The toxicity of acrylamide is mainly manifested as skin damage and nervous system damage. The U.S. Environmental Protection Agency (EPA) on propylene The regulations on the toxicity of amide to humans are: short-term and long-term oral or exposure to acryloyl can cause damage to the human nervous system, and it is considered that low-concentration acrylamide is also a substance that is harmful to the nervous system. Acute poisoning is the Irritation of the skin and respiratory tract, rash at the site of contact. Chronic poisoning causes neurotoxic reactions, affecting the central and peripheral nerves." "In 1994, the International Agency for Research on Cancer (IARC) investigated the genotoxicity to animals and raised acrylamide from Group 2B (possibly carcinogenic) to Group 2A (probably carcinogenic) in 1987." "In view of the impact of acrylamide on human beings, the environment and health, WHO, IARC, the US Food and Drug Administration (FDA), EPA, the European Union (EU) and the Chinese government have all made strict regulations on the limit of acrylamide in the environment ". "Countries have strict restrictions on the maximum allowable dosage of polyacrylamide in water treatment and the maximum allowable content of residual monomer acrylamide in polyacrylamide products. For example, WHO stipulates the dosage of polyacrylamide in water purification It shall not exceed 1mg/L. The residue of acrylamide in the product shall not exceed 0.05%, that is, the maximum residue of acrylamide in drinking water is 0.0005 mg/L". With the increasing awareness of environmental protection and the severe situation of waste (sewage) water pollution control, the requirements for water treatment are getting higher and higher. The purpose and significance of the present invention aim at the toxicity of existing monomers for preparing flocculants at home and abroad, select non-(low) toxic monomers, and adopt suitable polymerization methods and process conditions to prepare a non-(low) toxic, A practical, effective and economical new organic copolymer amphoteric polymer flocculant to meet the needs of waste (sewage) water treatment.

At present, synthetic amphoteric polymer flocculants have the following defects:

1. The synthetic amphoteric polymer flocculant uses highly toxic acrylamide and acrylonitrile monomers, and the residual monomers after polymerization and small molecules after decomposition will cause secondary pollution;

2. The Mannich reaction requires the use of a large amount of organic solvents, which does not conform to the principles of green chemistry;

3. Polyacrylamide amphoteric polymer flocculant modified by Mannich reaction is not suitable for treating wastewater with high pH, and its storage stability is not high.

The present invention can achieve better performance under the premise that the flocculation efficiency of the flocculant is not reduced:

1. The selected monomer has no (low) toxicity, does not cause secondary pollution, and meets the requirements of green chemistry;

2. Copolymerization uses water as a solvent, which is more in line with the principle of clean production;

3. Overcome the shortcomings of poor dehydration effect and unstable performance of polyacrylamide flocculants;

4. For copolymerization, redox initiators are used at low temperatures, and inorganic peroxide initiators are used at high temperatures. At the same time, acidity regulators and polymerization aids are used to make the molecular weight of the product meet the requirements of use and reduce residual monomers.

Contents of the invention

Through the new technology, an organic copolymerized amphoteric polymer flocculant with stable performance, wider application range and better flocculation effect and a preparation method with simple operation are provided.

The organic copolymerized amphoteric polymer flocculant is formed by copolymerization of dimethyl diallyl ammonium halide, N,N-dimethylaminoethyl acrylate, sorbic acid (salt) and bifunctional monomer diacrylate Copolymer, characterized in that,

Monomer 1 is dimethyl diallyl ammonium halide with the formula

                                                 

In the formula, X is Cl, Br;

Monomer 2 is N,N-dimethylaminoethyl acrylate, the structural formula is

;

Monomer 3 is sorbic acid (salt), the structural formula is

 

In the formula, Y is H, Na or K;

Difunctional monomer diacrylate, the structural formula is

 

Where 1≦i≦23 (i is a positive integer),

 

    

    

The structural formula of the copolymer formed by copolymerization of three kinds of monomers and bifunctional monomer diacrylate according to a certain amount ratio is

 

In the formula, 1≦n≦49481; 1≦m≦55859; 1≦p≦71342; 1≦q≦47004; 1≦i≦23, n, m, p, q, i are positive integers.

The preparation method of the present invention has no special requirements on the above three monomers, diacrylate difunctional monomers, redox initiators, inorganic peroxide initiators, acidity regulators and polymerization aids. For example, the copolymerization monomer, the general formula can be expressed as (CH ₂ =CHCH ₂ ) ₂ N ⁺ (CH ₃ ) ₂ X ^- dimethyl diallyl ammonium halide, and the chemical formula is expressed as CH ₂ =CHCOO(CH ₂ ) ₂ N(CH ₃ ) ₂ acrylate-N,N-dimethylaminoethyl ester, the general formula can be expressed as CH ₃ CH=CHCH=CHCOOY sorbic acid (salt), the general formula can be expressed as CH ₂ =CHCOO (R) Difunctional monomeric diacrylate of _i OOCCH=CH ₂ . The test results show that in order to achieve the best performance and economic efficiency of the organic copolymerized amphoteric polymer flocculant prepared by the present invention, the three monomers dimethyl diallyl ammonium halide, acrylic acid-N,N-di The ratio of the amount of methylaminoethyl ester and sorbic acid (salt) is controlled at (15-80): (10-70): (5-60) (mol%); the quality of the difunctional monomer diacrylate It is 0.8% to 10% of the sum of the mass of the other three monomers; the sum of the mass of the monomers accounts for 10% to 60% of the mass fraction of the total mass of the reaction system.

As mentioned above, the present invention adds a redox initiator at a relatively low temperature in the early stage of the copolymerization for the purpose of obtaining a copolymer with a large molecular weight. For example, the oxidizing agent selected can be any one of hydrogen peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, and the reducing agent is any one of sodium bisulfite, potassium bisulfite, sodium sulfite, sodium thiosulfate kind. The test results show that the ratio of the amount of oxidizing agent to reducing agent is 1: (1-0.2), and the ideal effect can be achieved in the range of 0.1%-2% of the total mass of the monomer.

As mentioned above, the present invention adds an inorganic peroxide initiator at a higher temperature in the later stage of polymerization, the purpose of which is to reduce the residual monomer and increase the conversion rate of the monomer. For example, hydrogen peroxide, ammonium persulfate, sodium persulfate, potassium persulfate are selected. The test results show that the conversion rate of the monomer can achieve the desired effect when the dosage is within the range of 0.02% to 2.0% of the total mass of the monomer.

As mentioned above, the present invention adds an acidity regulator in the copolymerization reaction to adjust the pH of the polymerization system to 2-9, the purpose of which is to ensure that the initiator used can achieve the most ideal initiation efficiency. The substance used to adjust the pH is an aqueous solution of any one of sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, sodium bicarbonate and hydrochloric acid.

As mentioned above, in the present invention, a polymerization assistant is added in the copolymerization reaction, the purpose of which is to prevent the primary free radicals formed by the redox initiator and monomer free radicals from being prematurely terminated. For example, any one of diethanolamine, triethanolamine, ethylenediaminetetraacetic acid and its salts, water-soluble fluorine-containing compounds such as fluosilicic acid, calcium fluosilicate, potassium fluoride, and sodium fluoride, or a mixture of two or more of them is selected. The test results show that the dosage is within the range of 0.01% to 1.5% of the total mass of the monomers, and the copolymerization reaction initiated by the redox initiator can obtain a large molecular weight organic copolymerized amphoteric polymer flocculant and the polymerization rate can be controlled.

The method of the present invention comprises the following steps and processing conditions:

Step 1. Add dimethyl diallyl ammonium halide, polymerization aid and distilled water into the four-neck reaction flask, stir and dissolve, vacuumize twice, each time is 5 minutes, and pass nitrogen once in the middle, time is 5 minutes;

Step 2. Dilute N,N-dimethylaminoethyl acrylate with distilled water and put it into the dropping funnel (a), dissolve sorbic acid (salt) with distilled water, add bifunctional monomer diacrylate and mix evenly into the dropping liquid funnel(b);

Step 3. Under the conditions of continuous stirring and nitrogen flow, add the redox initiator at one time, raise the temperature to 35°C~45°C, adjust the pH of the aqueous solution to 2~9, add acrylic acid-N,N- The aqueous solution of dimethylaminoethyl ester, the dropping funnel (b) drop the mixed solution of sorbic acid (salt) and bifunctional monomer diacrylate into the four-neck reaction flask, drop the two dropping funnels at the same time, and control The dropping speed, the dropping time is 0.5-3 hours, and the constant temperature is 0.5-4 hours after the dropping. During the dropping and constant temperature process, check the pH value of the reaction liquid in the four-neck reaction bottle every 15 minutes, and keep the pH at 2-4 hours. 9;

Step 4. Heat up to 75°C-85°C, add inorganic peroxide initiator to continue the reaction, check the pH value of the reaction liquid in the four-neck reaction bottle every 15 minutes, keep the pH at 2-9, and the reaction time is 1-3.5 hours , cooling, and discharging to obtain an organic copolymerized amphoteric polymer flocculant product;

In the method of the present invention, temperature-variable copolymerization is carried out by three kinds of monomers and bifunctional monomer diacrylate, and there are sufficient active free radicals in the reaction system, so that the copolymerization reaction can be continuously carried out; water-soluble redox agent is used as a low-temperature initiator , to ensure that the flocculant has a sufficiently high molecular weight; adjust the pH of the reaction system to make the initiation efficiency more ideal; add a certain amount of polymerization assistant to reduce the impurities in the reaction system and prevent the premature termination of active free radicals; The inorganic peroxide initiator is added in the later stage of the polymerization reaction, which reduces the residual monomer and improves the conversion rate.

Compared with the existing amphoteric polyacrylamide flocculants used for water treatment, the present invention has the following advantages:

1. Compared with the organic copolymerized amphoteric polymer flocculants produced by the prior art, the monomers used are non-toxic (low) and have almost no impact on the environment;

2. Water-soluble redox agent is used as the low-temperature initiator, and water-soluble peroxide initiator is added in the later stage to ensure that the flocculant has a sufficiently high molecular weight, and the conversion rate is higher and the residual monomer content is lower;

3. The preparation method is simple, the reaction conditions are mild, and it is suitable for popularization and application;

4. Stable performance, suitable for a wide range of pH value, many types of wastewater treatment, small input (only 1-200mg/L), and obvious economic benefits.

BRIEF DESCRIPTION OF THE DRAWINGS The attached figure is the chemical formula for the copolymerization reaction of monomer 1, monomer 2, monomer 3 and bifunctional monomer diacrylate in a certain ratio under the action of an initiator and a polymerization aid.

Implementation case The present invention is further described as follows in conjunction with embodiment:

Example 1

Step 1, add 16g dimethyl diallyl ammonium halide, 0.008g polymerization assistant sodium edetate and potassium fluoride in the 250mL four-neck reaction flask equipped with thermometer, nitrogen device and stirrer Stir the mixture and 4g of distilled water to dissolve, vacuumize twice for 5 minutes each time, and pass nitrogen once in the middle for 5 minutes;

Step 2. Dilute 3g of acrylate-N,N-dimethylaminoethyl with 14g of distilled water and put it into the dropping funnel (a), dissolve 2g of sorbic acid (salt) with 15g of distilled water, add 1g of bifunctional monomer diacrylate and mix Evenly load the dropping funnel (b);

Step 3, under the condition of continuous stirring and nitrogen flow, add the mixture of 0.21g redox initiator potassium persulfate and potassium bisulfite at one time, the ratio of the amount of substance of oxidizing agent and reducing agent is 1: 0.7, be warming up to 35 ℃, adjust the pH of the aqueous solution to 4, add the aqueous solution of N,N-dimethylaminoethyl acrylate dropwise into the dropping funnel (a), add sorbic acid (salt) and difunctional monomer di Add the mixed solution of acrylate to the four-neck reaction flask, and drop the two dropping funnels at the same time to control the dropping speed. The dropping time is 1 hour, and the temperature is kept constant for 4 hours after the dropping. Check the pH value of the reaction liquid in the four-neck reaction flask once, and keep the pH at 4;

Step 4. Heat up to 85°C, add 0.05g of inorganic peroxide initiator potassium persulfate to continue the reaction, check the pH value of the reaction liquid in the four-necked reaction flask every 15 minutes, keep the pH at 4, react for 3.5 hours, and cool , discharged to obtain an organic copolymerized amphoteric polymer flocculant product with a molecular weight of 7.1×10 ⁶ and a conversion rate of 97.3%.

the

Example 2

Step 1, add 32g dimethyl diallyl ammonium halide, 0.016g polymerization assistant sodium edetate and potassium fluoride in the 250mL four-neck reaction flask equipped with thermometer, nitrogen device and stirrer Stir the mixture and 8 g of distilled water to dissolve, vacuumize twice for 5 minutes each time, and pass nitrogen once in the middle for 5 minutes;

Step 2. Dilute 6g of acrylate-N,N-dimethylaminoethyl with 28g of distilled water and put it into the dropping funnel (a), dissolve 4g of sorbic acid (salt) with 30g of distilled water, add 2g of bifunctional monomer diacrylate and mix Evenly load the dropping funnel (b);

Step 3, under the condition of continuous stirring and nitrogen passage, add the mixture of 0.42g redox initiator potassium persulfate and potassium bisulfite at one time, the ratio of the amount of substance of oxidizing agent and reducing agent is 1: 0.6, be warming up to 45 ℃, adjust the pH of the aqueous solution to 7, add the aqueous solution of N,N-dimethylaminoethyl acrylate dropwise into the dropping funnel (a), add sorbic acid (salt) and difunctional monomer di Add the mixed solution of acrylate to the four-neck reaction flask, and drop the two dropping funnels at the same time to control the dropping speed. The dropping time is 1.5 hours, and the temperature is kept constant for 3.5 hours after the dropping. Check the pH value of the reaction liquid in the four-neck reaction flask once, and keep the pH at 7;

Step 4. Heat up to 80°C, add 0.1g of inorganic peroxide initiator potassium persulfate to continue the reaction, check the pH value of the reaction liquid in the four-necked reaction flask every 15 minutes, keep the pH at 7, react for 3 hours, cool , discharged to obtain an organic copolymerized amphoteric polymer flocculant product with a molecular weight of 7.3×10 ⁶ and a conversion rate of 97.6%.

the

application example

The No.1 and No.2 organic copolymerized amphoteric polymer flocculants prepared in the above Examples 1 and 2 were used for flocculation treatment of printing and dyeing wastewater (see Table 1 and Table 2).               

Claims (6)

1. an organic copolymerization Amphiphatic high polymer coagulant is characterized in that molecular weight is 9 * 10 ⁴～8 * 10 ⁶, it is to be formed by three kinds of monomers and the copolymerization of bifunctional monomer's diacrylate,

Monomer 1 is the dimethyl diallyl ammonium halide, and structural formula does

X is Cl, Br in the formula;

Monomer 2 is vinylformic acid-N, TMSDMA N dimethylamine base ethyl ester, and structural formula does

；

Monomer 3 is Sorbic Acid (salt), and structural formula does

Y is H, Na or K in the formula;

Bifunctional monomer's diacrylate, structural formula does

1 ≦ i in the formula ≦ 23 (i is a positive integer),

Three kinds of monomers and bifunctional monomer's diacrylate according to the structural formula of the multipolymer that certain amount forms than copolymerization do

1 ≦ n in the formula ≦ 49481; 1 ≦ m ≦ 55859; 1 ≦ p ≦ 71342; 1 ≦ q ≦ 47004; 1 ≦ i ≦ 23, n, m, p, q, i are positive integer.

2. the preparation method of an organic copolymerization Amphiphatic high polymer coagulant as claimed in claim 1 is characterized in that, step and processing condition that this method comprises are

Step 1, in four neck reaction flasks, add dimethyl diallyl ammonium halide, reagent and additive in polymerization and zero(ppm) water stirring and dissolving, vacuumize twice, each 5 minutes time, middle logical nitrogen once, 5 minutes time;

Step 2, with distilled water diluting vinylformic acid-N, TMSDMA N dimethylamine base ethyl ester adds bifunctional monomer's diacrylate with dissolved in distilled water Sorbic Acid (salt) back;

Step 3, under continuously stirring and logical nitrogen condition, disposable adding redox initiator is warming up to 35 ℃～45 ℃; Adjustment aqueous solution pH is 2～9, tap funnel dropwise addition of acrylic acid-N, and the mixed solution of the aqueous solution of TMSDMA N dimethylamine base ethyl ester, a tap funnel dropping Sorbic Acid (salt) and bifunctional monomer's diacrylate is in four neck reaction flasks; Two tap funnels drip simultaneously, the control rate of addition, and the dropping time is 0.5～3 hour; Dripped back constant temperature 0.5～4 hour; In dropping and the thermostatic process, the pH value of reaction liquid in one time four neck reaction flask of inspection in per 15 minutes, keeping pH is 2～9;

Step 4, be warming up to 75 ℃～85 ℃, add the inorganic peroxide initiator and continue reaction, the pH value of reaction liquid in one time four neck reaction flask of inspection in per 15 minutes; Keeping pH is 2～9,1～3.5 hour reaction times, cooling; Discharging obtains organic copolymerization Amphiphatic high polymer coagulant product;

Raw materials used is dimethyl diallyl ammonium halide, vinylformic acid-N, TMSDMA N dimethylamine base ethyl ester, Sorbic Acid (salt), bifunctional monomer's diacrylate, redox initiator, inorganic peroxide initiator, reagent and additive in polymerization and acidity regulator,

Wherein dimethyl diallyl ammonium halide, vinylformic acid-N, the ratio of TMSDMA N dimethylamine base ethyl ester, three kinds of monomeric amount of substances of Sorbic Acid (salt) is (15～80): (10～70): (5～60) (mol%),

The quality of bifunctional monomer's diacrylate is 0.8%～10% of other three kinds of monomeric quality sums,

The massfraction that the quality summation of three kinds of monomers and bifunctional monomer's diacrylate accounts for the reaction system total mass is 10%～60%;

The quality of redox initiator is 0.1%～2% of a monomer mass summation, and wherein oxygenant is 1 with the ratio of the amount of substance of reductive agent: (1～0.2);

The quality of inorganic peroxide initiator is 0.02%～2.0% of a monomer mass summation;

The quality of reagent and additive in polymerization is a monomer mass summation 0.01%～1.5%.

3. the preparation method of organic copolymerization Amphiphatic high polymer coagulant as claimed in claim 2; It is characterized in that the redox initiator in the claim 2 is that oxygenant is any in hydrogen peroxide, ammonium persulphate, Sodium Persulfate, the Potassium Persulphate, reductive agent is any in sodium sulfite anhy 96, Potassium hydrogen sulfite, S-WAT, the Sulfothiorine.

4. the preparation method of organic copolymerization Amphiphatic high polymer coagulant as claimed in claim 2 is characterized in that inorganic peroxide initiator in the claim 2 is any in hydrogen peroxide, ammonium persulphate, Sodium Persulfate, the Potassium Persulphate.

5. the preparation method of organic copolymerization Amphiphatic high polymer coagulant as claimed in claim 2 is characterized in that acidity regulator in the claim 2 is any in sodium hydroxide, Pottasium Hydroxide, calcium hydroxide, yellow soda ash, sodium hydrogencarbonate, the hydrochloric acid.

6. the preparation method of organic copolymerization Amphiphatic high polymer coagulant as claimed in claim 2 is characterized in that reagent and additive in polymerization in the claim 2 is any or the mixture more than two kinds in diethylolamine, trolamine, YD 30 and salt thereof, water-soluble fluorochemicals such as silicofluoric acid, calcium silicofluoride, Potassium monofluoride, the Sodium Fluoride.

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