阅读说明：本技术 一种混凝土减水剂及其制备方法 (A kind of cement water reducing agent and preparation method thereof ) 是由 房晓 于 2019-09-05 设计创作，主要内容包括：本发明属于混凝土外加剂技术领域,公开了一种混凝土减水剂,是以三聚氰胺、甲醛、磺化剂、熟化剂为主原料,辅以pH调节剂,经羟甲基化、磺化、缩合、熟化反应制备得到。本发明产品存储稳定性好、游离甲醛低,更环保,在混凝土拌合物中使用时,具有对水泥分散性好、减水率高且基本不影响混凝土凝结时间和含气量的特点,且可显著提高混凝土强度。(The invention belongs to technical field of concrete additives, disclose a kind of cement water reducing agent, are to be aided with pH adjusting agent using melamine, formaldehyde, sulfonating agent, curing agent as main material, be prepared through methylolation, sulfonation, condensation, slaking reaction.Product of the present invention storage stability is good, free formaldehyde is low, more environmentally friendly, in use, having the characteristics that cement good dispersion, water-reducing rate height and having substantially no effect on concrete coagulating time and air content in concrete mix, and is remarkably improved concrete strength.)

1. a kind of cement water reducing agent is to be aided with pH adjusting agent using melamine, formaldehyde, sulfonating agent, curing agent as main material, It is prepared through methylolation, sulfonation, condensation, slaking reaction.It is characterized in that, each component parts by weight are as follows: melamine 10- 30 parts, 20-50 parts of 37% formalin, 5-15 parts of sulfonating agent, 2-10 parts of curing agent, 0.05-0.5 parts of catalyst, acid pH 0.1-5 parts of regulator, 0.1-5 parts of alkaline pH adjusting agent, 30-80 parts of water.

2. cement water reducing agent according to claim 1, which is characterized in that the sulfonating agent is sodium hydrogensulfite, Jiao Ya One or both of sodium sulphate.

3. cement water reducing agent according to claim 1, which is characterized in that the curing agent be diisopropyl ethanolamine or Triethylene glycol.

4. cement water reducing agent according to claim 1, which is characterized in that the catalyst is phthalic anhydride or horse Carry out acid anhydrides.

5. cement water reducing agent according to claim 1, which is characterized in that the acidic ph modifier is glycolic.

6. cement water reducing agent according to claim 1, which is characterized in that the alkaline pH adjusting agent is tetramethylphosphonihydroxide hydroxide Ammonium.

7. cement water reducing agent described in any claim 1-6, which is characterized in that the preparation side of the cement water reducing agent Method, comprising the following steps:

A, hydroxymethylation: equipped with thermometer, condenser and blender reaction kettle in by formula ratio be added melamine, Water, formalin, regulation system pH value to 9-11 are warming up to 50-70 DEG C, react 30-60min.

B, sulfonating reaction: the sulfonating agent of methylolation product and formula ratio is put into reaction kettle, is warming up to 70-85 DEG C, is maintained The pH value of solution reacts 60-120min between 9-11.

C, condensation reaction: the temperature of reaction system is reduced to 40-60 DEG C, adjustment pH value to 4-5 reacts 40-80min.

D, the temperature of reaction system slaking reaction: is risen into 75-85 DEG C plus curing agent, catalyst reaction 60-150min.

E, neutralization reaction: being down to room temperature for reactant, adjusts pH to 6-7 to get the cement water reducing agent.

Technical field

The invention belongs to technical field of concrete additives, and in particular to a kind of cement water reducing agent and preparation method thereof.

Background technique

Melamine system water reducer is a kind of anionic, early strong, non-research work of air entrained type high efficiency water reducing agent, is had excellent performance, can It is obviously improved the multiple performance of concrete, with significant diminishing, reinforcing effect compared with general cement water reducing agent, and The setting time on coagulation and air content are had substantially no effect on, it is good to adaptability such as steam-curing concrete and clear-water concretes.But it passes Non- PARA FORMALDEHYDE PRILLS(91,95) is handled through row in the melamine water reducing agent preparation process of system, so that containing the first that remaining is free in portioned product Aldehyde does not meet the requirement of environmental protection, and the complete formaldehyde of unreacted also will continue to that polymerization reaction occurs in storing process, cause to make Standby water-reducing agent stability is poor, stores the improper water-reducing rate that will cause and is greatly reduced.

Summary of the invention

The present invention is in view of the above-mentioned problems, provide a kind of cement water reducing agent, and the water-reducing agent free formaldehyde content is low, product Stability is good, and in order to achieve the above objectives, the present invention uses following technical scheme.A kind of cement water reducing agent, be with melamine, Formaldehyde, sulfonating agent, curing agent are main material, are aided with pH adjusting agent, are prepared through methylolation, sulfonation, condensation reaction, slaking reaction It obtains.It is characterized in that, dosage of each component (parts by weight) are as follows: 10-30 parts of melamine, 20-50 parts of 37% formalin, 5-15 parts of sulfonating agent, 2-10 parts of curing agent, 0.05-0.5 parts of catalyst, 0.1-5 parts of acidic ph modifier, alkaline pH adjusting agent 0.1-5 parts, 30-80 parts of water.

The preparation method of above-mentioned cement water reducing agent, comprising the following steps:

A, trimerization hydroxymethylation: is added by formula ratio in the reaction kettle equipped with thermometer, condenser and blender Cyanamide, water, formalin, regulation system to alkaline environment are warming up to 50-70 DEG C, react 30-60min.

B, sulfonating reaction: the sulfonating agent of methylolation product and formula ratio being put into reaction kettle, is warming up to 70-85 DEG C, It maintains the pH value of solution 8 or more, reacts 60-120min.

C, condensation reaction: the temperature of reaction system is reduced to 40-60 DEG C, adjustment system to acidic environment reacts 40- 80min。

D, the temperature of reaction system slaking reaction: is risen into 75-85 DEG C plus curing agent, catalyst reaction 60-150min.

E, neutralization reaction: being down to room temperature for reactant, adjusts pH value to faintly acid to get the cement water reducing agent.

The sulfonating agent is one or both of sodium hydrogensulfite, sodium pyrosulfite.

The curing agent is diisopropyl ethanolamine or triethylene glycol.

Preferably, the curing agent is diisopropyl ethanolamine.

The catalyst is phthalic anhydride or maleic anhydride.

The acidic ph modifier is one of sulfuric acid, glycolic.

Preferably, the acidic ph modifier is glycolic.

The alkaline pH adjusting agent is one of sodium hydroxide, tetramethylammonium hydroxide.

Preferably, the alkaline pH adjusting agent is tetramethylammonium hydroxide.

Further, the preparation method of above-mentioned cement water reducing agent, comprising the following steps:

A, trimerization hydroxymethylation: is added by formula ratio in the reaction kettle equipped with thermometer, condenser and blender Cyanamide, water, formalin, regulation system pH value to 9-11 are warming up to 50-70 DEG C, react 30-60min.

B, sulfonating reaction: the sulfonating agent of methylolation product and formula ratio being put into reaction kettle, is warming up to 70-85 DEG C, It maintains the pH value of solution between 9-11, reacts 60-120min.

C, condensation reaction: the temperature of reaction system is reduced to 40-60 DEG C, adjustment pH value to 4-5 reacts 40-80min.

D, the temperature of reaction system slaking reaction: is risen into 75-85 DEG C plus curing agent, catalyst reaction 60-150min.

E, neutralization reaction: being down to room temperature for reactant, adjusts pH to 6-7 to get the cement water reducing agent.

It should be noted that methylolated melamine sulfonating reaction is due in alkaline medium in the sulfonating reaction stage In, disproportionated reaction can occur under excess formaldehyde and high pH for system, generate formic acid, decline pH value of reaction system, easily send out too early Polycondensation reaction between raw methylol, system viscosity increase.It, during the reaction should be every to ensure that the water conservancy of sulfonating reaction carries out The pH value of a system is detected every 10min, and adjusts pH value in time in control range.Curing agent, which can be closed, possesses reaction work Property methylol, make methylol resolve into free formaldehyde back reaction rate reduce, reduce free formaldehyde content, can also reduce The reactivity of methylol prevents the reaction such as further occurrence polymerization in storing process, improves the stability of product；Hydroxide Tetramethylammonium may additionally facilitate the reaction of formaldehyde and melamine in addition to having the function of adjustment system pH value, improve reaction efficiency and Product yield reduces free formaldehyde content；Glycolic has the duality of alcohol and acid concurrently, not only adjustable system pH, but also can promote Into slaking reaction.

The utility model has the advantages that

(1) product of the present invention storage stability is good, free formaldehyde is low, more environmentally friendly.

(2) product of the present invention is in concrete mix in use, having high and basic to cement good dispersion, water-reducing rate The characteristics of not influencing concrete coagulating time and air content, and it is remarkably improved concrete strength, 7d gain in strength is rapid.

Specific embodiment