阅读说明：本技术 一种高分子类石膏缓凝剂及其制备方法和应用 (Polymer gypsum retarder and preparation method and application thereof ) 是由 王肇嘉 战佳宇 杨飞华 李沙 李万民 温晓庆 于 2020-12-14 设计创作，主要内容包括：本发明提供一种高分子类石膏缓凝剂及其制备方法和应用,所述高分子类石膏缓凝剂,包括以下原料：包括以下原料：聚环氧琥珀酸、聚天冬氨酸和聚羧酸减水剂。本发明还提供高分子类石膏缓凝剂的制备方法和高分子类石膏缓凝剂的应用。本发明提供的高分子类石膏缓凝剂能够在石膏浆体硬化过程中实现高效缓凝,同时降低用水量提高强度,有效解决由于缓凝而引起石膏强度降低的问题。(The invention provides a polymer gypsum retarder as well as a preparation method and application thereof, wherein the polymer gypsum retarder comprises the following raw materials: the method comprises the following raw materials: polyepoxysuccinic acid, polyaspartic acid and polycarboxylic acid water reducing agent. The invention also provides a preparation method of the polymer gypsum retarder and application of the polymer gypsum retarder. The polymer gypsum retarder provided by the invention can realize high-efficiency retarding in the hardening process of gypsum slurry, simultaneously reduces the water consumption, improves the strength, and effectively solves the problem of gypsum strength reduction caused by retarding.)

1. A polymer gypsum retarder is characterized by comprising the following raw materials: polyepoxysuccinic acid, polyaspartic acid and polycarboxylic acid water reducing agent.

2. The polymer gypsum retarder of claim 1, wherein the polycarboxylate water reducer is a polyester water reducer or a polyether water reducer; preferably, the polyester water reducer is a methacrylic acid water reducer, and the polyether water reducer is an allyl ether water reducer.

3. The polymer gypsum retarder according to claim 2, which is prepared from the following raw materials in parts by weight:

10-70 parts of polyepoxysuccinic acid

2.5-60 parts of polyaspartic acid

5-50 parts of a polycarboxylic acid water reducing agent.

4. The polymer gypsum retarder according to claim 3, which is prepared from the following raw materials in parts by weight:

20-60 parts of polyepoxysuccinic acid

5-40 parts of polyaspartic acid

10-50 parts of a polycarboxylic acid water reducing agent.

5. The polymer gypsum retarder according to claim 4, which is prepared from the following raw materials in parts by weight:

20-50 parts of polyepoxysuccinic acid

5-40 parts of polyaspartic acid

10-40 parts of a polycarboxylic acid water reducing agent.

6. A preparation method of a polymer gypsum retarder is characterized by comprising the following steps: mixing the polyepoxysuccinic acid and the polyaspartic acid, and then spray-drying into powder.

7. The method for preparing the polymer gypsum retarder according to claim 6, comprising: mixing the polyepoxysuccinic acid, the polyaspartic acid and the polycarboxylate superplasticizer, and then spray-drying into powder.

8. Use of the polymer gypsum retarder according to any one of claims 1 to 5 or the polymer gypsum retarder obtained by the preparation method according to claim 6 or 7, in addition to gypsum for retarding and compensating for strength loss.

9. The use of claim 8, wherein the polymeric gypsum-based retarder is added in an amount of 0.01 to 0.5% by weight based on the total weight of the gypsum.

10. Use according to claim 8 or 9, wherein β -CaSO in the gypsum₄·1/2H₂The content of O is 60 to 95 percent.

Technical Field

The invention relates to the technical field of gypsum cementing materials, in particular to a high-molecular gypsum retarder as well as a preparation method and application thereof.

Background

The semi-hydrated gypsum and the anhydrous gypsum formed by calcining or cooking the gypsum at a certain temperature are important cementing materials, and the gypsum cementing materials have the advantages of low production energy consumption, light weight, good fireproof performance, quick setting, heat insulation, fire resistance, humidity regulation, good decoration and the like. Has been widely used for preparing gypsum composite cementing materials, building gypsum products, industrial moulds, artistic models and the like.

In practical application, after being mixed with water, the gypsum cementing material has short setting time and can lose fluidity within a few minutes, so that in order to meet the requirements of production technology or construction operation, a retarder is often required to be added to prolong the setting time, so that the gypsum slurry can keep plasticity for a long time. The gypsum retarder disclosed in the prior art comprises small-molecular organic acid and soluble salt thereof, alkaline phosphate and macromolecular protein. Although these retarders can have a good retarding effect, when the usage amount is too large, the strength of the gypsum hardened body will generate a large loss, which seriously affects the wide application of the gypsum cementing material. There is therefore still a need to provide new retarders that achieve high retardation at low loadings and low strength loss.

Disclosure of Invention

The embodiment of the invention provides a high-molecular gypsum retarder which can realize high-efficiency slow setting in the hardening process of gypsum slurry, simultaneously reduce the water consumption and improve the strength, and effectively solve the problem of low gypsum strength caused by slow setting.

The embodiment of the invention provides a polymer gypsum retarder, which comprises the following raw materials: polyepoxysuccinic acid, polyaspartic acid and polycarboxylic acid water reducing agent.

In the invention, in the hardening process of the gypsum slurry, negatively charged groups in polyepoxysuccinic acid and polyaspartic acid molecules in the retarder can be chelated with calcium ions in the gypsum, so that the concentration of the calcium ions in the solution is reduced, and the calcium ions are adsorbed on active growth points of gypsum crystals, thereby causing lattice distortion and reducing the growth rate of the gypsum crystals. Polyepoxysuccinic acid and polyaspartic acid have synergistic retarding effect and can realize high-efficiency retarding at low mixing amount. Meanwhile, the water consumption of the standard thickness of the gypsum can be reduced due to the steric hindrance and the dispersion of macromolecules of the polycarboxylic acid water reducing agent, the strength loss caused by the delayed coagulation of polyepoxysuccinic acid and polyaspartic acid components is compensated, and the water consumption is further reduced and the strength is improved.

According to the polymer gypsum retarder provided by the embodiment of the invention, the polycarboxylate water reducer is a polyester water reducer or a polyether water reducer; preferably, the polyester water reducer is a methacrylic acid water reducer, and the polyether water reducer is an allyl ether water reducer.

The polymer gypsum retarder provided by the embodiment of the invention comprises the following raw materials in parts by weight:

10-70 parts of polyepoxysuccinic acid

2.5-60 parts of polyaspartic acid

5-50 parts of a polycarboxylic acid water reducing agent.

The polymer gypsum retarder provided by the embodiment of the invention comprises the following raw materials in parts by weight:

20-60 parts of polyepoxysuccinic acid

5-40 parts of polyaspartic acid

10-50 parts of a polycarboxylic acid water reducing agent.

The polymer gypsum retarder provided by the embodiment of the invention is prepared from the following raw materials in parts by weight:

20-50 parts of polyepoxysuccinic acid

5-40 parts of polyaspartic acid

10-40 parts of a polycarboxylic acid water reducing agent.

According to the invention, by adopting the components in the parts by weight, the setting time of gypsum can be effectively prolonged and the water consumption of standard consistency can be reduced in the hardening process of gypsum slurry, so that the strength loss of a gypsum hardened body is reduced. So that the function is better played.

The embodiment of the invention also provides a preparation method of the polymer gypsum retarder, which comprises the following steps: mixing the polyepoxysuccinic acid and the polyaspartic acid, and then spray-drying into powder.

The preparation method of the polymer gypsum retarder provided by the embodiment of the invention comprises the following steps: mixing the polyepoxysuccinic acid, the polyaspartic acid and the polycarboxylate superplasticizer, and then spray-drying into powder. In the invention, the high molecular gypsum retarder obtained by the method is added into gypsum for prolonging the setting time of the gypsum and reducing the strength loss of a gypsum hardened body,

the embodiment of the invention also provides an application of the polymer gypsum retarder or the polymer gypsum retarder obtained by the preparation method in retarding and compensating strength loss by adding the polymer gypsum retarder into gypsum; preferably, the gypsum composite cementing material is applied to gypsum composite cementing materials and gypsum building products, wherein the gypsum composite cementing materials comprise plastering gypsum, putty and gypsum-based self-leveling mortar, and the gypsum building products comprise gypsum boards, gypsum blocks and gypsum decorative products. The high-molecular gypsum retarder provided by the invention can have good effects of retarding and compensating strength loss in the gypsum composite cementing material and gypsum building products.

According to the application provided by the embodiment of the invention, the addition amount of the polymer gypsum retarder is 0.01-0.5% of the total weight of the gypsum.

According to the application provided by the embodiment of the invention, the beta-CaSO in the gypsum₄·1/2H₂The content of O is 60 to 95 percent.

The invention has the beneficial effects that: the high molecular gypsum retarder provided by the invention reduces the growth rate of gypsum crystals in the hardening process of gypsum slurry, can realize high-efficiency retarding at a low mixing amount, and can reduce the water consumption of standard consistency of gypsum and reduce the strength loss.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention are described clearly and completely below, and it is obvious that the described embodiments are some, not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The examples do not show the specific techniques or conditions, according to the technical or conditions described in the literature in the field, or according to the product specifications. The instruments and the like are conventional products which are purchased by normal distributors and are not indicated by manufacturers. The process is conventional unless otherwise specified, and the starting materials are commercially available from the open literature. The examples do not show the specific techniques or conditions, according to the technical or conditions described in the literature in the field, or according to the product specifications.

According to the invention, the polyepoxysuccinic acid is of formula:

M＝H⁺、Na⁺、K⁺、NH₄ ⁺

polyaspartic acid is of the formula:

the polycarboxylate superplasticizer is a polyester type superplasticizer or polyether type superplasticizer; wherein

The polyester water reducing agent has the following formula:

R₁、R₂＝-H、-CH₃

R₃＝-CH₂-CH₂-、

R₄＝C₁～C₄、-H

M＝H⁺、Na⁺、K⁺

preferred methacrylic water reducing agents:

the polyether water reducing agent is as follows:

R₁、R₂、R₃、R₅＝-H、-CH₃

R₄＝-CH₃、-C₂H₅、

R₆＝-CH₂-CH₂-、

R₇＝Cv₁～C₄、-H

X＝-CH₂-、

Y＝-CH₂-、-C＝O

M＝H⁺、Na⁺、K⁺

preferably an allyl ether water reducing agent, of the formula:

in the following examples of the present invention, the polyepoxysuccinic acid used is specifically polyepoxysuccinic acid sodium; the polycarboxylic acid water reducing agent is a methacrylic acid water reducing agent; the polyaspartic acid is polyaspartic acid sodium salt; beta-CaSO in the gypsum₄·1/2H₂The O content is 90 +/-5%.

Example 1

The embodiment provides a polymer gypsum retarder, and a preparation method thereof comprises the following steps:

and (3) putting 60 parts of polyepoxysuccinic acid, 20 parts of polyaspartic acid and 20 parts of polycarboxylic acid water reducer into a stirrer according to the weight of dry matters, fully and uniformly mixing, and performing spray drying to prepare powder, thus obtaining the polymer gypsum retarder.

The retarder prepared in the embodiment is added into the building gypsum, the addition amount of the retarder is 0.01 percent of the total weight of the gypsum, and the setting time and the strength performance test are carried out under the water consumption of standard consistency.

Comparative example 1

And (3) taking the building gypsum without the retarder as a comparison, and testing the setting time and the strength performance under the water consumption of the standard consistency.

Table 1 example 1 comparison of performance test results

Example 2

The embodiment provides a polymer gypsum retarder, and a preparation method thereof comprises the following steps:

and (3) putting 20 parts of polyepoxysuccinic acid, 40 parts of polyaspartic acid and 40 parts of polycarboxylic acid water reducer into a stirrer according to the weight of dry matters, fully and uniformly mixing, and performing spray drying to prepare powder so as to obtain the polymer gypsum retarder.

The retarder prepared in the embodiment is added into the building gypsum, the addition amount of the retarder is 0.05 percent of the total weight of the gypsum, the setting time and the strength performance test are carried out under the water consumption of standard consistency, and meanwhile, the building gypsum without the retarder is used as a comparison.

Table 2 example 2 comparison of performance test results

Example 3

The embodiment provides a polymer gypsum retarder, and a preparation method thereof comprises the following steps:

and (3) putting 40 parts of polyepoxysuccinic acid, 30 parts of polyaspartic acid and 30 parts of polycarboxylic acid water reducer into a stirrer according to the weight of dry matters, fully and uniformly mixing, and performing spray drying to prepare powder so as to obtain the polymer gypsum retarder.

The retarder prepared in the embodiment is added into the building gypsum, the addition amount of the retarder is 0.5 percent of the total weight of the gypsum, the setting time and the strength performance test are carried out under the water consumption of standard consistency, and meanwhile, the building gypsum without the retarder is used as a comparison.

Table 3 comparison of results of performance measurements for example 3

Example 4

The embodiment provides a polymer gypsum retarder, and a preparation method thereof comprises the following steps:

and (3) putting 45 parts of polyepoxysuccinic acid, 5 parts of polyaspartic acid and 50 parts of polycarboxylic acid water reducer into a stirrer according to the weight of dry matters, fully and uniformly mixing, and performing spray drying to prepare powder, thus obtaining the polymer gypsum retarder.

The retarder prepared in the embodiment is added into the building gypsum, the addition amount of the retarder is 0.05 percent of the total weight of the gypsum, the setting time and the strength performance test are carried out under the water consumption of standard consistency, and meanwhile, the building gypsum without the retarder is used as a comparison.

Table 4 example 4 comparison of performance test results

Comparative examples 2 to 4

Comparative examples 2-4 show the synergistic retarding effect of polyepoxysuccinic acid and polyaspartic acid by comparing the effect of adding polyepoxysuccinic acid and polyaspartic acid alone and the effect of the mixture of polyepoxysuccinic acid and polyaspartic acid on the performance of gypsum.

Putting 50 parts of polyepoxysuccinic acid and 50 parts of polyaspartic acid into a stirrer, fully and uniformly mixing according to the weight of dry matters, and preparing powder by spray drying.

Polyepoxy succinic acid (comparative example 2) in an amount of 0.05% by weight based on the total weight of gypsum, polyaspartic acid (comparative example 3) in an amount of 0.05% by weight based on the total weight of gypsum, and a mixed retarder (comparative example 4) in an amount of 0.025% by weight based on the total weight of polyepoxy succinic acid and polyaspartic acid prepared as described above were added to the building gypsum, respectively, and the setting time and strength properties were measured at the same water amount for the standard consistency.

TABLE 5 comparative examples 2-4 Performance test results

Comparative example 5

A methacrylic acid water reducing agent in an amount of 0.5% of the total weight of gypsum was added to the building gypsum, and the setting time and strength performance tests were carried out at a water consumption of standard consistency by weight of dry matter, while the building gypsum without retarder (comparative example 1) was used as a comparison.

Table 6 comparative example 5 performance test results

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.