WO2021226869A1

WO2021226869A1 - Solid polycarboxylic acid water reducing agent and preparation method therefor

Info

Publication number: WO2021226869A1
Application number: PCT/CN2020/090002
Authority: WO
Inventors: 朱建民; 刘兆滨; 董振鹏; 杨雪; 张建东
Original assignee: 辽宁奥克化学股份有限公司
Priority date: 2020-05-13
Filing date: 2020-05-13
Publication date: 2021-11-18
Also published as: DE112020007177T5

Abstract

The present invention provides a solid polycarboxylic acid water reducing agent and a preparation method therefor. The preparation method comprises: melting a polyether polyol monomer and a hyperbranched monomer into a liquid; adding an initiator to the liquid, stirring, and then adding an unsaturated carboxylic acid and a chain transfer agent to obtain a mixed solution; and performing aging treatment on the mixed solution, and then cooling and solidifying to obtain the solid polycarboxylic acid water reducing agent. According to the solid polycarboxylic acid water reducing agent in the present invention, the hyperbranched monomer is added, so that the requirement for the viscosity during polymerization is reduced, the workability of concrete is better in the concrete evaluation process, there are no phenomena such as bleeding, mortar bleeding, and stone leakage, and under the condition of a low water-cement ratio, the viscosity of the concrete can be decreased. In addition, according to the method in the present invention, the anhydrous solid polycarboxylic acid water reducing agent product can be obtained once the preparation is ended. Unlike the traditional stock solution water agent, a powder polycarboxylic acid water reducing agent can be obtained by spray drying. Compared with the powder polycarboxylic acid water reducing agent, the solid polycarboxylic acid water reducing agent greatly reduces the production cost and the long distance transport cost.

Description

Solid polycarboxylic acid water reducer and preparation method thereof

Technical field

The invention relates to the field of concrete admixtures, in particular to a solid polycarboxylic acid water reducing agent and a preparation method thereof.

Background technique

Water reducer is an indispensable part in today's concrete industry, starting from the first generation of lignosulfonate series of ordinary water reducing agents, to the second generation of naphthalene-based water-reducing agents, melamine-based water-reducing agents, and amino High-efficiency water-reducing agents such as sulfonate-based water-reducing agents and fatty acid-based water-reducing agents, and to the current third-generation polycarboxylic acid-based high-performance water-reducing agents, each water-reducing agent has its own unique advantages; In particular, the polycarboxylic acid-based high-performance water-reducing agent is the most widely used concrete in today's concrete, and it has its presence in major projects.

However, most of the polycarboxylic acid-based water-reducing agents on the market are mainly mother liquor water agents, and the solid content of the product is generally about 40%-50%, which will increase the cost during transportation. The application in engineering construction is restricted. Although the mother liquor of water reducing agent can be directly converted into powder polycarboxylic acid by spray drying method, the spray drying method has high energy consumption, and some products will be lost during drying and production. Security Question.

CN108192041A discloses a preparation method and application of a powdered polycarboxylic acid water reducing agent, the preparation of a benzene ring-containing polycarboxylic acid water reducing agent and how to spray and dry it into a powdered polycarboxylic acid water reducing agent Method and application. The preparation method includes: preparing a polycarboxylic acid monomer a, a small benzene ring-containing monomer b, and a benzene ring-containing polyether monomer c in an aqueous medium through free radical copolymerization to obtain a polycarboxylic acid water reducing agent Mother liquor; the polycarboxylic acid water-reducing agent mother liquor is directly passed through the centrifugal atomizer of the sprayer to form droplets without adding a release agent. The average particle size of the powder is controlled to be 50-150um, and the droplets are dried after entering the drying chamber The material is turned into powder, and the material is led to the discharge port through the induced draft fan, and the material is packaged and discharged by the bag packaging machine to obtain the powdery polyshuttle acid water reducing agent. The invention will have a certain loss during the spray centrifugation process, and spray drying requires a higher temperature, and the energy consumption requirement under the same output is too high.

CN108484841A discloses a method for preparing a solid sheet-like polycarboxylic acid water-reducing agent by bulk polymerization. The solid sheet-like polycarboxylic acid water-reducing agent is prepared by bulk polymerization, and a certain amount of just synthesized liquid polyether is monohydrated. Add body and viscosity reducer into the reaction kettle, stir and heat; control the temperature at 100-105℃, start adding a certain amount of initial initiator, organic peroxy initiator, solubilizer, chain transfer agent, initial initiator; 5min later , Start to add the small monomer solution, the time for adding the small monomer solution is a hour, the small monomer solution is composed of a certain proportion of fluorinated functional monomer and acrylic acid; after the small monomer solution is added dropwise for 10 minutes, put it into the kettle A certain amount of organic peroxygen initiator is put in every 10 minutes afterwards, until the last time is put in before the small monomer solution is dripped; after the dripping, the temperature is raised to 110-115℃, and the temperature is maintained Constant, curing for b hours, then cooling the slices and packaging to obtain a solid sheet-like polycarboxylic acid water reducing agent. In the invention, the process is relatively complicated in the synthesis process, and the higher reaction temperature causes a great loss of energy consumption.

It should be noted that the information disclosed in the foregoing background section is only used to enhance the background understanding of the present invention, so it may include information that does not constitute the prior art known to those of ordinary skill in the art.

Summary of the invention

The purpose of the present invention is to overcome the shortcomings of the prior art and provide a solid polycarboxylic acid water reducing agent with good workability and low production and transportation costs.

In order to achieve the above objectives, the present invention adopts the following technical solutions:

A preparation method of solid polycarboxylic acid water reducing agent, including:

Melt polyether monomer and hyperbranched monomer into liquid;

Adding an initiator to the liquid and stirring, then adding an unsaturated carboxylic acid and a chain transfer agent to obtain a mixed solution; and

The mixed solution is subjected to aging treatment, and then cooled and solidified to obtain the solid polycarboxylic acid water reducing agent.

In some embodiments, based on the total mass of each raw material, the added amount of the polyether monomer is 82-89%, the added amount of the hyperbranched monomer is 0.4-3%, and the unsaturated carboxylic acid The addition amount of the chain transfer agent is 7-11%, the addition amount of the chain transfer agent is 0.2-0.7%, and the addition amount of the initiator is 0.4-1.5%.

In some embodiments, the polyether monomer is selected from one or more of methallyl polyoxyethylene ether, prenol polyoxyethylene ether and hydroxybutyl polyoxyethylene ether, and The molecular weight of the polyether monomer is 1200-5000, preferably 2000-4000.

In some embodiments, the hyperbranched monomer has a structure as shown in Formula I, wherein n is an integer from 1 to 15, m is an integer from 1 to 10, x is an integer from 1 to 10, and y is from 1 to 1. An integer of 10.

In some embodiments, the initiator is selected from benzoyl peroxide, lauryl peroxide, ammonium persulfate, potassium persulfate, sodium persulfate, azobisisobutyronitrile, azobisisoheptonitrile, One or more of azobisisovaleronitrile, azobiscyclohexylcarbonitrile, dimethyl azodiisobutyrate, dicyclohexyl peroxydicarbonate, and hexadecyl peroxydicarbonate.

In some embodiments, the unsaturated carboxylic acid is selected from one or more of acrylic acid, methacrylic acid, itaconic acid, maleic anhydride, maleic acid, and fumaric acid.

In some embodiments, the chain transfer agent is selected from sodium methacrylate sulfonate, sodium allyl sulfonate, thioglycolic acid, mercaptopropionic acid, mercaptoethanol, n-dodecyl mercaptan, sodium hypophosphite, ethylene One or more of sodium sulfonate, sodium propenyl sulfonate and sodium styrene sulfonate.

In some embodiments, the unsaturated carboxylic acid and the chain transfer agent are added to the liquid by dropping, and the dropping time is 0.5-2h.

In some embodiments, the aging treatment time is 0.5-3h.

On the other hand, the present invention provides a solid polycarboxylic acid water reducing agent, which is prepared according to the above method.

Due to the addition of hyperbranched monomers, the solid polycarboxylate water-reducing agent of the present invention has reduced requirements for viscosity during polymerization, and has good workability to concrete in the process of concrete evaluation, without bleeding, bleeding, or bleeding. Phenomena such as stone leakage can reduce the viscosity of concrete under the condition of low water-cement ratio. In addition, the method of the present invention can obtain an anhydrous solid polycarboxylic acid water reducing agent product after the preparation is completed, and it does not need to be spray-dried like the traditional mother liquor water agent to obtain the powder polycarboxylic acid water reducing agent, and the powder polycarboxylic acid water reducing agent Compared with the agent, the production cost and the long-distance transportation cost are greatly reduced.

Detailed ways

The technical solution of the present invention will be further described below according to specific embodiments. The protection scope of the present invention is not limited to the following embodiments, and these examples are listed for exemplary purposes only and do not limit the present invention in any way.

The invention provides a preparation method of a solid polycarboxylic acid water reducing agent, which comprises the following steps:

Melt polyether monomer and hyperbranched monomer into liquid;

Based on the total mass of each raw material, the added amount of the polyether monomer is 82-89%, the added amount of the hyperbranched monomer is 0.4-3%, and the added amount of the unsaturated carboxylic acid is 7- 11%, the added amount of the chain transfer agent is 0.2-0.7%, and the added amount of the initiator is 0.4-1.5%.

The polyether monomer and the hyperbranched monomer first melt into a liquid within a certain temperature range. The polyether monomer can be completely melted first, and then the hyperbranched monomer is added to melt. The temperature of the chemical material can be controlled at 65-100°C.

The polyether monomer used in the present invention is selected from one or more of methallyl polyoxyethylene ether, prenol polyoxyethylene ether and hydroxybutyl polyoxyethylene ether, and the polyether monomer The molecular weight is 1200-5000, preferably 2000-4000.

The hyperbranched monomer used in the present invention is a polymer obtained by adding polyvinyl polyamine as a raw material to random blocks of ethylene oxide and propylene oxide. It has a structure as shown in formula I, where n represents epoxy The addition number of ethane (EO), which is an integer of 1-15, preferably an integer of 3-10, m represents the addition number of propylene oxide (PO), which is an integer of 1-10, preferably 2 An integer of -6, x is an integer of 1-10, and y is an integer of 1-10.

After both the polyether monomer and the hyperbranched monomer are melted into a liquid, an initiator needs to be added to the liquid and stirred. The initiator used in the present invention is an oil-soluble initiator, which is selected from the group consisting of benzoyl peroxide and ten Diacyl, ammonium persulfate, potassium persulfate, sodium persulfate, azobisisobutyronitrile, azobisisoheptonitrile, azobisisovaleronitrile, azobiscyclohexylcarbonitrile, azobisisobutyric acid One or more of dimethyl ester, dicyclohexyl peroxydicarbonate and hexadecyl peroxydicarbonate, the stirring time is usually 5-10min.

After adding the initiator and stirring, add the unsaturated carboxylic acid and the chain transfer agent to the liquid. The unsaturated carboxylic acid and the chain transfer agent can be mixed first and then added at the same time. 0.5-2h.

The unsaturated carboxylic acid used in the present invention is selected from one or more of acrylic acid, methacrylic acid, itaconic acid, maleic anhydride, maleic acid and fumaric acid.

The chain transfer agent used in the present invention is selected from sodium methacrylate sulfonate, sodium allyl sulfonate, thioglycolic acid, mercaptopropionic acid, mercaptoethanol, n-dodecyl mercaptan, sodium hypophosphite, sodium vinyl sulfonate , One or more of sodium propenyl sulfonate and sodium styrene sulfonate.

After adding the unsaturated carboxylic acid and the chain transfer agent, a mixed solution is obtained, and the mixed solution is continuously stirred under a certain constant temperature condition for aging treatment, and the aging treatment time is 0.5-3h.

After the aging treatment, the temperature is lowered to about 60°C and the material is discharged, and the anhydrous solid polycarboxylic acid water reducing agent can be obtained when the product is solidified at room temperature.

The solid polycarboxylic acid water-reducing agent prepared by the present invention can be prepared by adding water to the solid polycarboxylic acid water-reducing agent into liquids of different concentrations or further processed into powdered solid polycarboxylic acid water-reducing agent according to different construction requirements. The solid polycarboxylic acid water-reducing agent can be directly mixed into dry-mixed mortar or sprayed concrete for use. The original performance of the water-reducing agent will not be reduced during the change of the shape.

Due to the addition of hyperbranched monomers, the solid polycarboxylic acid water-reducing agent of the present invention has reduced requirements for viscosity during polymerization, and at the same time, its state is stable, and no adhesion occurs when stored at room temperature. The solid polycarboxylic acid water-reducing agent of the present invention has excellent water-reducing and dispersing effect, and has good workability to concrete in the process of concrete evaluation. It exhibits good fluidity and retention ability, maintains excellent workability at different dosages, and shows strong adaptability to different types of cement.

In addition, the preparation process of the present invention can directly obtain anhydrous solid polycarboxylic acid water-reducing agent products, and does not need to be spray-dried like the traditional mother liquor water agent to obtain the powder polycarboxylic acid water-reducing agent. The mother liquor of carboxylic acid water reducer is simple and has a short cycle, and is more convenient in operation. The product has more obvious advantages in transportation distance and transportation cost. At the same time, if polyether thermal materials can be used to produce solid polycarboxylic acid water reducer, the total cost can be saved. About 30%, which greatly improves the energy saving and consumption reduction of water reducing agent manufacturers.

Therefore, the overall process of the preparation method of the present invention is green and environmentally friendly, is conducive to industrialized production and industrialized promotion and application, and has good economic benefits and social significance.

The following specific examples are used to further illustrate the present invention. These examples describe preferred implementations, but do not constitute a limitation to the present invention. Any person familiar with the profession may use the above-mentioned content of the invention to change it into equivalent changes. The equivalent embodiment.

Example

Preparation Example Synthesis of Hyperbranched Monomer

In a 0.3L dry stainless steel autoclave, 40g of polyethylene polyamine, 0.2g of catalyst, nitrogen replacement for 3 times in the airtight reactor, heated to 120°C, slowly add 29.34g of ethylene oxide and 23.2g to the reactor at the same time Propylene oxide, maintain the reaction temperature at 120-130°C and pressure 0.3-0.4MPa during the feeding process. After feeding is completed, continue stirring at 120°C for 1 hour, and then cool to about 75-80°C for discharge to obtain hyperbranched monomers. body.

Example 1

First put 350g of methallyl polyoxyethylene ether (theoretical molecular weight is 2400) into the reactor, heat up to 70°C, after the material is completely melted into a liquid state, add 3.5g of the hyperbranched monomer obtained in the preparation example and continue stirring 10min, then add 3.5g benzoyl peroxide as initiator. After stirring for 10min, start dripping the mixture of 37.5g acrylic acid and 2g thioglycolic acid. Control the dripping reaction time within 1h±5min. After the reaction, the temperature is raised to 75℃ After aging for 2 hours, pour into the tray and discharge the material after the aging is finished. After the product is solidified, an anhydrous solid polycarboxylic acid water reducing agent can be obtained.

Example 2

First, put 357g of methallyl polyoxyethylene ether (theoretical molecular weight 3000) into the reactor, raise the temperature to 75°C, after the material is completely melted into a liquid state, add 4g of the hyperbranched monomer obtained in the preparation example and continue stirring for 10 minutes , After adding the initiator 3.6g benzoyl peroxide, stirring for 10 minutes, start to add dropwise feeding by a mixture of 37.9g acrylic acid and 2.2g sodium hypophosphite, control the dripping reaction time at 1h±5min, and aging for 2h after the end of the reaction. After the aging is over, pour into the tray and discharge the material. After the product is solidified, an anhydrous solid polycarboxylic acid water reducing agent can be obtained.

Example 3

First, put 351g of methallyl polyoxyethylene ether (theoretical molecular weight 3000) into the reactor, and raise the temperature to 75°C. After the material is completely melted into a liquid state, add 5g of the hyperbranched monomer obtained in the preparation example and continue stirring for 10 minutes , After adding 4g azobisisobutyronitrile as the initiator, stirring for 10min, start to add dropwise a mixture of 35.3g acrylic acid, 1.5g mercaptopropionic acid, 0.7g mercaptoethanol, and control the dripping reaction time within 1h±5min. Aging for 2 hours after the end, pour into the tray after the end of the aging, and after the product is solidified, an anhydrous solid polycarboxylic acid water reducing agent can be obtained.

Example 4

First, put 345g of prenol polyoxyethylene ether (theoretical molecular weight of 2400) into the reactor, and raise the temperature to 75°C. After the material is completely melted into a liquid state, add 5g of the hyperbranched monomer obtained in the preparation example and continue stirring for 10 minutes. After adding 4g azobisisobutyronitrile as the initiator, stirring for 10min, start to add dropwise a mixture of 40.2g methacrylic acid and 2.3g sodium hypophosphite, control the dripping reaction time within 1.5h±5min, and aging after the end of the reaction 2.5h, after the aging is finished, pour it into the tray and discharge it. After the product is solidified, an anhydrous solid polycarboxylic acid water reducing agent can be obtained.

Example 5

First, put 326g of isopentenol polyoxyethylene ether (theoretical molecular weight 3000) into the reactor, raise the temperature to 70°C, after the material is completely melted into a liquid state, add 6g of the hyperbranched monomer obtained in the preparation example and continue stirring for 10 minutes. After adding initiator 2g azobisisobutyronitrile, 2.5g azobisisovaleronitrile, stirring for 10min, start to add dropwise a mixture of 36.2g methacrylic acid, 2.3g sodium hypophosphite, control the dripping reaction time in 1.5h±5min, aging for 2.5h after the end of the reaction, pour into the tray after the end of aging, and after the product solidifies, an anhydrous solid polycarboxylic acid water reducing agent can be obtained.

Example 6

First, 364g of hydroxybutyl polyoxyethylene ether (theoretical molecular weight is 2400) is put into the reactor, and the temperature is raised to 75°C. After the material is completely melted into a liquid state, 6g of the hyperbranched monomer 3 obtained in the preparation example is added and the stirring is continued for 10 minutes , After adding initiator 3.8g ammonium persulfate, stirring for 10min, start to add dropwise feeding by a mixture of 30.9g methacrylic acid and 3g sodium methacrylic acid sulfonate, control the dripping reaction time within 1h±5min, and aging after the reaction is over 2.5h, after the aging is finished, pour it into the tray and discharge it. After the product is solidified, an anhydrous solid polycarboxylic acid water reducing agent can be obtained.

Example 7

First, put 350g of hydroxybutyl polyoxyethylene ether (theoretical molecular weight is 3000) into the reactor, and raise the temperature to 75°C. After the material is completely melted into a liquid state, add 3g of the hyperbranched monomer obtained in the preparation example and continue stirring for 10 minutes. After adding the initiator 3.8g ammonium persulfate, stirring for 10min, start to add dropwise a mixture of 30.9g methacrylic acid and 3g sodium methacrylic acid sulfonate, control the dripping reaction time within 1h±5min, and aging 2.5 after the completion of the reaction h. After the aging is finished, pour into the tray and discharge the material. After the product is solidified, an anhydrous solid polycarboxylic acid water reducing agent can be obtained.

Example 8

First put 342g of hydroxybutyl polyoxyethylene ether (theoretical molecular weight of 3600) into the reactor, and raise the temperature to 80°C. After the material is completely melted into a liquid state, 4g of the hyperbranched monomer obtained in the preparation example is added and stirring is continued for 10 minutes. After adding initiator 3.5g azobisisobutyronitrile, stirring for 5 minutes, start to add dropwise a mixture of 32.7g methacrylic acid, 7g itaconic acid, 1g mercaptopropionic acid, 0.7g mercaptoethanol, and control the dripping reaction time At 1h±5min, aging for 2h after the end of the reaction. After aging, pour into the tray and discharge the material. After the product is solidified, an anhydrous solid polycarboxylic acid water reducing agent can be obtained.

Put the solid polycarboxylic acid water-reducer prepared in Examples 1-8 into an oven to melt, and use a petroleum product kinematic viscosity tester to test the viscosity of the samples of Examples 1-8 and Comparative Example 1 at 70°C with a viscometer. -8 viscosity, the comparative example is only that the hyperbranched monomer is not added under the same conditions as the example, and the molecular weight of the sample of example 1-8 and the comparative example 1-8 (without hyperbranched monomer added) are tested by gel liquid chromatography. ) The molecular weight of the sample, and the results are shown in Table 1.

Table 1 Comparison of viscosity and molecular weight of solid polycarboxylic acid water-reducer prepared in Example and Comparative Example

It is concluded through the test that the viscosity of the sample after adding the hyperbranched monomer is generally between 3000-3500, and the viscosity without the hyperbranched monomer is generally between 4900-5500, and the molecular weight of the solid polycarboxylic acid water-reducing agent is not large. Change; it is proved that adding hyperbranched monomers can significantly reduce the viscosity of solid polycarboxylic acid water-reducing agent. The decrease in viscosity indicates that the equipment requirements of solid polycarboxylic acid water-reducing agent in the production have been reduced, and the production will be increased when the product is sliced There is improvement, and there is more room for improvement in product profit.

The solid polycarboxylic acid water-reducing agent prepared in Examples 1-8 is configured as a water-reducing agent with a concentration of 10%. According to the test requirements of the high-performance water-reducing agent in the GB8076-2008 "Concrete Additives" standard, the examples are synthesized The performance of the sample and the commercial water reducer (HD-14 high-performance polycarboxylic acid water reducer produced by Shenyang Haida Building Material Factory) was compared. The experimental formulation is shown in Table 2, and the concrete performance test results are shown in Tables 3 and 4. Shown.

Table 2 Concrete test ratio (kg/m ³ )

Table 3 Concrete performance test results of Qianshan Cement 42.5

Table 4 Concrete performance test results of Conch Cement 42.5

The above-mentioned experimental results show that the solid polycarboxylic acid water-reducing agent prepared by the present invention has good adaptability to different types of cement, and has a higher water-reducing rate and retention performance than the mother liquor of traditional polycarboxylic acid water-reducing agent, and the present invention The addition of hyperbranched monomer reduces the viscosity of the product and the bleeding rate of concrete without obvious bleeding, bleeding and stone leakage, which can improve the workability of concrete to a certain extent.

Those skilled in the art should note that the described embodiments of the present invention are only exemplary, and various other substitutions, changes and improvements can be made within the scope of the present invention. Therefore, the present invention is not limited to the above-mentioned embodiments, but only by the claims.

Claims

A preparation method of solid polycarboxylic acid water reducing agent, characterized in that it comprises:

Melt polyether monomer and hyperbranched monomer into liquid;

Adding an initiator to the liquid and stirring, then adding an unsaturated carboxylic acid and a chain transfer agent to obtain a mixed solution; and

The mixed solution is subjected to aging treatment, and then cooled and solidified to obtain the solid polycarboxylic acid water reducing agent.
The preparation method according to claim 1, characterized in that, based on the total mass of each raw material, the added amount of the polyether monomer is 82-89%, and the added amount of the hyperbranched monomer is 0.4-3 %, the addition amount of the unsaturated carboxylic acid is 7-11%, the addition amount of the chain transfer agent is 0.2-0.7%, and the addition amount of the initiator is 0.4-1.5%.
The preparation method according to claim 1, wherein the polyether monomer is selected from the group consisting of methallyl polyoxyethylene ether, prenol polyoxyethylene ether and hydroxybutyl polyoxyethylene ether And the molecular weight of the polyether monomer is 1200-5000, preferably 2000-4000.
The preparation method according to claim 1, wherein the hyperbranched monomer has a structure as shown in formula I, wherein n is an integer of 1-15, m is an integer of 1-10, and x is 1- An integer of 10, and y is an integer of 1-10.
The preparation method according to claim 1, wherein the initiator is selected from the group consisting of benzoyl peroxide, lauryl peroxide, ammonium persulfate, potassium persulfate, sodium persulfate, azobisisobutyronitrile , Azobisisoheptonitrile, azobisisovaleronitrile, azobiscyclohexylcarbonitrile, dimethyl azodiisobutyrate, dicyclohexyl peroxydicarbonate and hexadecyl peroxydicarbonate One or more of.
The preparation method according to claim 1, wherein the unsaturated carboxylic acid is selected from one or more of acrylic acid, methacrylic acid, itaconic acid, maleic anhydride, maleic acid and fumaric acid .
The preparation method according to claim 1, wherein the chain transfer agent is selected from the group consisting of sodium methacrylate sulfonate, sodium allyl sulfonate, thioglycolic acid, mercaptopropionic acid, mercaptoethanol, n-dodecyl One or more of mercaptan, sodium hypophosphite, sodium vinyl sulfonate, sodium propylene sulfonate and sodium styrene sulfonate.
The preparation method according to claim 1, wherein the unsaturated carboxylic acid and the chain transfer agent are added to the liquid by dropwise addition, and the time for the dropwise addition is 0.5-2h.
The preparation method according to claim 1, wherein the time of the aging treatment is 0.5-3h.
A solid polycarboxylic acid water reducing agent, characterized in that the solid polycarboxylic acid water reducing agent is prepared according to any one of claims 1 to 9.