阅读说明：本技术 一种涂膏型缓凝剂及其制备方法和应用 (Paste-coating retarder and preparation method and application thereof ) 是由 牛蒙召 胡建军 祝战奎 李娟� 王海龙 于 2021-01-13 设计创作，主要内容包括：本申请涉及建筑材料的技术领域,具体公开了一种涂膏型缓凝剂及其制备方法和应用。缓凝剂包括以下重量份的组分：葡萄糖酸钠113-200份,柠檬酸25-47份,增稠剂8-15份,水688-813份；其制备方法为：S1、准备原料；S2、将葡萄糖酸钠、氧化铁加于水中,得到混合液；将包括柠檬酸和增稠剂混合,得到混合物；S3、将所述混合物缓慢加入所述混合液中,并边加边搅拌；S4、静止至溶液为膏状即可。本申请的缓凝剂可用于预制构件的局部缓凝,其具有长期稳定、有效的优点。(The application relates to the technical field of building materials, and particularly discloses a paste-coating retarder as well as a preparation method and application thereof. The retarder comprises the following components in parts by weight: 200 parts of sodium gluconate 113-; the preparation method comprises the following steps: s1, preparing raw materials; s2, adding sodium gluconate and ferric oxide into water to obtain a mixed solution; mixing citric acid and a thickening agent to obtain a mixture; s3, slowly adding the mixture into the mixed solution, and stirring while adding; and S4, standing until the solution is pasty. The retarder can be used for local retarding of prefabricated parts and has the advantages of long-term stability and effectiveness.)

1. The paste coating type retarder is characterized by comprising the following components in parts by weight:

200 parts of sodium gluconate 113-.

2. The plastering retarder according to claim 1, which is characterized by comprising the following components in parts by weight:

162 parts of sodium gluconate 127-containing material, 29-41 parts of citric acid, 10-14 parts of thickening agent and 788 parts of water 743-containing material.

3. The paste-coating type retarder according to claim 1, wherein the thickener is obtained from Shankang chemical Co., Ltd., Ningpo City, with the product model number of SK-006; or the thickening agent is purchased from Rituqiu city Titian chemical industry Co., Ltd, and the product model is LT 051.

4. The pasting type retarder according to claim 1, further comprising 0.7-1.3 parts of iron oxide.

5. The plastering retarder according to claim 1, further comprising 3 to 7 parts of porous silicone microspheres.

6. A method for preparing the paste-coating type retarder according to any one of claims 1 to 4, characterized by comprising the steps of:

s1, preparing sodium gluconate, citric acid, a thickening agent, ferric oxide and water for later use;

s2, adding sodium gluconate and ferric oxide into water, and stirring to dissolve the sodium gluconate to obtain a mixed solution;

uniformly mixing citric acid and a thickening agent to obtain a mixture;

s3, slowly adding the mixture into the mixed solution, and stirring while adding;

and S4, standing until the solution is pasty.

7. The method for preparing the plastering retarder according to claim 6, wherein the mixture further comprises porous silicone microspheres, and in S2, the citric acid, the thickener and the porous silicone microspheres are uniformly mixed to obtain the mixture.

8. Use of a plaster-type retarder according to any one of claims 1 to 5 for the local retardation of prefabricated parts in order to be able to form a bare concrete surface.

Technical Field

The application relates to the technical field of building materials, in particular to a paste-coating retarder and a preparation method and application thereof.

Background

In the construction field, when large-area floor slabs are prepared, prefabricated parts and cast-in-place concrete are often required to be combined to form new large-area plates. The prefabricated member generally uses cement mortar to form a plate main body, and a plurality of steel bars are arranged in the length direction of the plate in a penetrating mode, so that the prefabricated member can be better connected with cast-in-place concrete. When the prefabricated member is prepared, an exposed aggregate concrete surface needs to be prepared on a joint surface of the prefabricated member and cast-in-place concrete, and coarse aggregates at the joint surface are exposed by 4-6mm, so that new concrete and old concrete can be reliably connected, and the tensile and shear resistance of the concrete at the joint surface is effectively improved.

When the exposed aggregate concrete surface is manufactured on the prefabricated part, firstly, a layer of retarder is coated on the inner sides of the side walls at two ends of a mould for manufacturing the prefabricated part, then cement mortar is poured, the retarder is coated on the side wall of the mould, so that the solidification speed of cement mortar at other parts is higher than that of the cement mortar at the side wall of the mould, when the cement mortar at other parts is solidified and the cement mortar at the side wall of the mould is not solidified, the prefabricated part is taken out from the mould, and then two ends of the prefabricated part are washed, so that coarse aggregate is exposed for 4-6mm, and the exposed aggregate concrete surface is formed.

When the retarder is selected, the commonly used retarder in the field of buildings mostly uses corn starch and heavy calcium as paste materials, and the retarder has the defect of short shelf life. The emulsion system of the retarder obtained according to the formula is unstable after one month after the retarder is prepared, and the retarder becomes thin or precipitates or is polluted by mixed bacteria; particularly in summer, when the temperature of the external environment is too high, the retarder is more prone to deterioration, so that a large amount of preservative needs to be added to obtain a longer shelf life, but the retarder is still prone to thinning or precipitation.

Disclosure of Invention

The application provides a plaster type retarder, a preparation method and an application thereof.

In a first aspect, the application provides a paste-coating retarder, which adopts the following technical scheme:

a paste coating type retarder comprises the following components in parts by weight:

200 parts of sodium gluconate 113-.

By adopting the technical scheme, the sodium gluconate and the citric acid are matched with each other, so that the effect of retarding coagulation is mainly achieved; in addition, the citric acid has certain antiseptic and antibacterial effects, so that the retarder has an excellent retarding effect on the whole. The addition of the thickening agent enables the retarder to be in a uniform, viscous and coatable paste shape; the sodium gluconate and the citric acid are both dissolved in water, and the thickening agent can be mixed with the solution system to realize an excellent thickening effect, so that the finally prepared coatable paste substance with the long shelf life of the retarder can be stored for 46-61 days at the ambient temperature of 37-39 ℃. When the using amount of the thickening agent is too much, the retarder is solid paste and is difficult to coat; when the amount of the thickener is too small, the prepared retarder is easy to become thin or precipitate. In addition, when the amount of citric acid is too large, the stability of the retarder is reduced, and the retarder is likely to become thin or precipitate in a short period of time: excessive citric acid usage can cause the pH of the retarder to drop, causing the pasty system of the retarder to be damaged, and further affecting the stability of the retarder. Therefore, the retarder prepared by adopting the mixture ratio maintains the system stability of the retarder through the synergistic cooperation effect between the citric acid and the thickening agent, so that the retarder has a longer shelf life.

Preferably, the paste-coating retarder comprises the following components in parts by weight:

162 parts of sodium gluconate 127-containing material, 29-41 parts of citric acid, 10-14 parts of thickening agent and 788 parts of water 743-containing material.

By adopting the technical scheme, the retarder prepared according to the formula proportion can be kept at the ambient temperature of 37-39 ℃, and the shelf life of the retarder is 51-61 days.

Preferably, the thickening agent is purchased from Shankang chemical industry Co., Ltd, Ningpo City, and the product model is SK-006; or the thickening agent is purchased from Rituqiu city Titian chemical industry Co., Ltd, and the product model is LT 051.

By adopting the technical scheme, the two thickeners are selected, and compared with other thickeners, the stability of the retarder can be effectively improved, so that the retarder is stable within 46-74 days without the phenomena of thinning or precipitation.

Preferably, the paste type retarder further comprises 0.7 to 1.3 parts of iron oxide.

By adopting the technical scheme, the iron oxide is mainly used as a coloring agent, so that the prepared retarder can be matched with the color of the prefabricated member main body.

Preferably, the paste-coating retarder also comprises 3-7 parts of porous organic silicon microspheres.

The porous organic silicon microsphere is a multifunctional special organic silicon resin microsphere, is snowy white regular free-flowing spherical fine micro powder, has a three-dimensional cross-linked reticular molecular structure, and shows excellent heat resistance and dispersion performance. The sphere has a porous structure, and the average particle size is 0.5-10 μm.

By adopting the technical scheme, when the porous organic silicon microspheres are used for preparing the obtained retarder, the excellent heat resistance of the porous organic silicon microspheres improves the heat stability of the retarder; the porous structure among the porous organic silicon microspheres enables other components in the retarder to enter the interior of the retarder, so that the porous organic silicon microspheres can be more uniformly dispersed in a retarder system; finally, the stability of the retarder is improved, and the service cycle of the retarder is prolonged, so that the shelf life of the retarder is in the range of 53-74 days.

In a second aspect, the application provides a preparation method of a paste-coating retarder, which adopts the following technical scheme:

a preparation method of a paste-coating retarder comprises the following steps:

s1, preparing sodium gluconate, citric acid, a thickening agent, ferric oxide and water for later use;

s2, adding sodium gluconate and ferric oxide into water, and stirring to dissolve the sodium gluconate to obtain a mixed solution; uniformly mixing citric acid and a thickening agent to obtain a mixture;

s3, slowly adding the mixture into the mixed solution, and stirring while adding;

and S4, standing until the solution is pasty.

By adopting the technical scheme, in the step S3, when the mixture is added into the mixed solution, the slow adding mode can effectively avoid the caking in the adding process; and the operation of adding the mixture and stirring in the mixed solution can ensure that the mixture and the mixed solution can be uniformly mixed on one hand, and also avoid caking on the other hand, thereby ensuring the uniformity and stability of the prepared retarder and further prolonging the quality guarantee period of the retarder.

Preferably, the mixture further comprises porous silicone microspheres, and in S2, the citric acid, the thickener and the porous silicone microspheres are uniformly mixed to obtain the mixture.

Because the thickening agent can be called as sticky after being stirred in water, and the porous organic silicon microspheres are substances with solid different from water, the porous organic silicon microspheres, the thickening agent and the citric acid are mixed in advance by adopting the technical scheme, so that the three are fully mixed. And then the solid mixture of the three is added into water together, so that the porous organic silicon microspheres also participate in the formation process of the viscous retarder after the thickening agent is added, the porous organic silicon microspheres are fully dispersed in the system, and the retarder has excellent stability.

In a third aspect, the application provides an application of a paste-coating retarder, which adopts the following technical scheme: use of a plaster-type retarder for the local retardation of prefabricated parts to enable the formation of a bare aggregate concrete surface.

By adopting the technical scheme, when the retarder is used for local retarding of the prefabricated part to obtain the exposed aggregate concrete surface, the exposed aggregate amount of the exposed aggregate concrete surface is 4-6mm, and the construction requirement is met.

In summary, the present application has the following beneficial effects:

1. the retarder comprises citric acid, sodium gluconate and a thickening agent, has a longer shelf life in a high-temperature environment (37-39 ℃) in summer under the condition of no addition of an additional preservative through the synergistic effect of the thickening agent and the citric acid, and does not have a solid-liquid demixing deterioration phenomenon in a period of 46-61 days; the manpower and material resources for multiple retarder preparation are reduced under the healthy and pollution-free conditions, and the method is convenient for practical application in building construction.

2. According to the application, the porous organic silicon microspheres are used in the raw materials for preparing the retarder, so that the quality guarantee period of the retarder is effectively prolonged, and the quality guarantee period is as long as 74 days.

3. The quality guarantee period of the retarder is as long as 75-90 days in winter, which is much longer than that of other retarders by 30-45 days.

Detailed Description

The present application will be described in further detail with reference to examples.

Examples

Example 1

A paste-coating retarder comprises the following components: 150kg of sodium gluconate, 29kg of citric acid, 10kg of thickening agent and 788kg of water; wherein the thickening agent is purchased from Shankang chemical Co., Ltd, Ningpo City, and the product model is SK-006. The preparation method of the retarder comprises the following steps:

s1, preparing sodium gluconate, citric acid, a thickening agent, ferric oxide and water for later use;

s2, adding sodium gluconate and ferric oxide into water and stirring to dissolve the sodium gluconate to obtain a mixed solution; uniformly mixing citric acid and a thickening agent to obtain a mixture;

s3, slowly adding the mixture into the mixed solution, and stirring while adding the mixture to avoid agglomeration in the process;

and S4, stirring the solution in the S3 uniformly, standing for 17min, and forming the solution into a paste to obtain the retarder.

The retarder is coated to two side edges of a mold for preparing the prefabricated part, cement mortar is poured in the mold, after the cement mortar is solidified, the mold is taken away, two sides of the prefabricated part are washed away (namely, two sides in contact with the retarder coated on the mold), and the setting time of the cement mortar at the position is longer due to the contact between the position and the retarder, after the cement mortar at other positions is solidified, the position is not completely solidified, when the cement mortar is washed away by water, fine aggregate, cement and the like can be washed away, and the coarse aggregate is partially exposed, so that an exposed aggregate concrete surface is formed.

Examples 2 to 17

Examples 2-17 differ from example 1 in the fact that the retarder is prepared from different raw materials and/or amounts of raw materials, as shown in Table 1, otherwise the same as example 1.

TABLE 1

Wherein the thickener with the product model number LT051 is purchased from Rituqin City Nature chemical Co Ltd; the porous organic silicon microspheres are purchased from new materials Co, Ltd, of Dongguan city, and have the product model of KM-9000 and the average particle size of 2 mu m.

Comparative example

Comparative example 1

Comparative examples 1 to 6 differ from example 16 in the fact that the retarder is prepared from different raw materials and/or amounts of raw materials, as shown in Table 2, and otherwise in example 16.

TABLE 2

Comparative example 7

Comparative example 7 differs from example 16 in that the thickener selected was pregelatinized starch, which was obtained from Shankang chemical Co., Ltd, Ningpo City. Otherwise, the same as example 16.

Comparative example 8

Comparative example 8 differs from example 16 in that the thickener selected was hydroxypropyl methylcellulose available from rituximab limited, anyu city. Otherwise, the same as example 16.

Comparative example 9

Comparative example 9 differs from example 16 in that the thickener selected is hydroxyethyl cellulose, available from Shanghai health chemical Co., Ltd. Otherwise, the same as example 16.

Comparative example 10

Comparative example 10 differs from example 16 in that the retarder selected in this comparative example is a gypsum retarder commonly used in the construction field, a high molecular protein gypsum retarder available from Wangming brand of Wangming science and technology Limited, Beijing.

Comparative example 11

Comparative example 11 differs from example 16 in that no thickener is included in the raw materials from which the set retarder is made. Otherwise, the same as example 16.

The retarders prepared in the examples 1-17 and the retarders prepared in the comparative examples 1-10 are placed in the same environment, the environment temperature is controlled to be 37-39 ℃, and the deterioration time is observed. Criteria for deterioration were: the retarder has macroscopic solid-liquid demixing (the solid-liquid demixing exceeds 1cm, namely the upper liquid phase has 1 cm). The specific results are shown in Table 3.

TABLE 3

As seen from the data results of table 3: the retarder has good stability at high environmental temperature (37-39 ℃), has long shelf life, and is not easy to generate the condition of solid-liquid layering (thinning or mould breeding): in an external environment at 37-39 ℃, the retarder can maintain a usable stable state within 46-74 days, and the quality guarantee period is long.

Among these, as can be seen from the data results of examples 4 to 14 and comparative examples 1 to 4, the amounts of citric acid and thickener have an effect on the shelf life of the retarder: when the amount of citric acid is in the range of 25-47 parts (i.e., 25-47kg for examples 1-14), the retarder remains in a stable usable state for a period of time as long as 46-61 days; when the amount of the citric acid exceeds 25-47 parts (namely 55kg of the amount in the comparative example 1), the shelf life of the retarder is shortened due to excessive amount of the citric acid, so that the shelf life of the retarder is shortened from 46-61 days to 30 days, and the time period for maintaining the retarder in a stable state is remarkably shortened; when the consumption of citric acid is too small, the bacteriostatic property of the retarder is poor, and a large amount of mould grows and breeds (8-9 days), so that the stable system of the retarder is damaged, solid precipitates appear and the phenomenon of solid-liquid stratification is obvious; the absence of citric acid (comparative example 2) further reduced the shelf life of the retarder to 20 days.

When the amount of the thickener is in the range of 8-15 parts (i.e., 8-15kg for examples 1-14), the retarder remains in a stable state for a period of time as long as 46-61 days; and when the amount of the thickening agent exceeds the range of 8-15 parts (namely, the amount of the thickening agent is 20kg or 4kg in comparative examples 3-4), the shelf life of the retarder is only 25-29 days, and the shelf life is obviously shortened. In comparative example 11, when the retarder was not composed of the thickener, the obtained retarder was liquid and could not be formed into a desired paste, nor was it gel-like, and thus it could not be used normally.

The possible reason is that the addition of the thickening agent enables the components in the retarder to be kept in a stable state, and the dosage of the citric acid can affect the pH value of the system to a certain extent, so that the stability of the retarder is affected, and the retarder is thin, deposited and bred with mould in a short time. Thus, the thickener and citric acid can cooperate to provide a retarder with a longer shelf life.

Furthermore, as can be seen from the data results of example 1, example 12 and comparative examples 7-9, the different thickeners have an effect on the time period during which the retarder is able to remain in a stable state: wherein, when the SK-006 type thickener and the LT051 type thickener are selected, the shelf life of the obtained retarder is as long as 46-61 days; when the pregelatinized starch, hydroxypropyl methyl cellulose or hydroxyethyl cellulose thickener is selected, the shelf life of the obtained thickener is only 7-12 days, which is far lower than that of the retarder of the application for 46-74 days.

The data results of examples 15-17 and comparative examples 5-6 show that the shelf life of the retarder can be remarkably prolonged after the porous organic silicon microspheres are added, so that the shelf life of the retarder is 74 days at most; however, when the addition amount of the porous silicone microspheres is too much, the shelf life of the retarder is reduced, especially when the addition amount is more than 7kg (comparative example 6), the shelf life of the retarder is only 41 days, which is far less than the shelf life of 53 days in example 17, and the reason may be that the porous silicone microspheres are inorganic water-insoluble materials, when the porous silicone microspheres are used for retarder preparation and the use amount is within a proper range, the thickener, citric acid, sodium gluconate and the porous silicone microspheres interact with each other, so that the acting forces such as ionic bonds, van der waals force and the like in the whole system are in a balanced and stable state, and further, the addition of the porous silicone can improve the thermal stability of the retarder. However, when the amount of the porous silicone microspheres is too large, intermolecular forces and the like in the system cannot maintain the long-term stability of the system, i.e., the porous silicone microspheres are difficult to stably exist in the system of the retarder for a long time, so that the retarder is easy to precipitate, and the shelf life is shortened.

In addition, the retarder of the present application has a longer shelf life at higher ambient temperatures than the conventional commercially available retarder (comparative example 10).

In conclusion, the retarder is not easy to delaminate in a high-temperature environment in summer under the condition that no additional preservative is added. In the formula for preparing the retarder, the synergistic effect of the citric acid and the thickening agent ensures that the retarder has longer shelf life; the requirement that a batch of retarder can be used for a long time when being configured in the building field is met, manpower and material resources are greatly saved, the time period for repeatedly configuring the retarder is shortened, and great convenience is brought to the preparation of prefabricated parts in the building field.

On the basis of the above research, the inventors further studied the shelf life of the retarder of the present application in winter (-8 to-5 ℃), placed the retarders prepared in the above examples 1-17 and comparative examples 1-10 in the same environment, controlled the environmental temperature at-8 to-5 ℃, and observed the deterioration time. Criteria for deterioration were: the retarder appeared to precipitate visually. The results show that the shelf life of the retarders obtained in examples 1-17 is as long as 75-90 days, and the retarders have excellent stability; the quality guarantee period of the retarder in the comparative examples 1-6 is only 30-45 days, and a large amount of precipitates are easy to appear; the shelf lives of the retarders obtained in comparative examples 7-9 were 35 days, 38 days, and 36 days, respectively, which were also much shorter than the shelf life of the retarder of the present application.

The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.