CN111606669B

CN111606669B - Gypsum board and preparation method thereof

Info

Publication number: CN111606669B
Application number: CN201910495715.1A
Authority: CN
Inventors: 王丽; 陈红霞; 尚珺虓; 周全光
Original assignee: China National Building Materials Innovation and Technology Research Institute Co Ltd
Current assignee: China National Building Materials Innovation and Technology Research Institute Co Ltd
Priority date: 2019-06-06
Filing date: 2019-06-06
Publication date: 2021-12-17
Anticipated expiration: 2039-06-06
Also published as: CN111606669A

Abstract

The application discloses gypsum board, the gypsum board includes: 80-98 parts of gypsum powder and 1-10 parts of silica sol. The application also provides a preparation method of the gypsum board. The gypsum board has high strength and also has good humidity conditioning performance.

Description

Gypsum board and preparation method thereof

Technical Field

The application relates to the field of building materials, in particular to but not limited to a paper-surface gypsum board and a preparation method thereof.

Background

Humidity is closely related to human production and life, and the normal life of people can be influenced by over-low humidity or over-high humidity. Therefore, controlling indoor humidity is very important for production and life, especially for humid and arid areas, and adjusting humidity is very important. Indoor humidity control generally adopts an active mode and a passive mode. The active method is mainly the air conditioning technology in the prior art, has large investment and high energy consumption, is easy to generate noise pollution, causes the problems of 'building indoor air conditioning syndrome' and the like, and is not suitable for long-term use. The humidity adjusting material is used as a means for adjusting indoor relative humidity, and has the advantages of not consuming artificial energy and adjusting indoor air humidity by utilizing the self humidity absorbing and releasing performance.

The paper-surface gypsum board is an ecological, environment-friendly and convenient decoration building material, has beautiful plasticity and a breathing function, can adjust the indoor air humidity of a building, and is widely applied to indoor decoration. However, because the water resistance of gypsum is poor, after the paper-faced gypsum board absorbs moisture in a high-humidity environment, the flexibility of the board is increased, and the strength is greatly reduced, so that the application of the paper-faced gypsum board is greatly hindered. Therefore, there is a need for a paper-faced gypsum board having high moisture regulating properties and good strength stability.

Disclosure of Invention

The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

The application provides a thistle board, thistle board still has fine humidifying performance when having high strength. The application solves the contradiction between the humidity regulating performance and the mechanical strength of the paper-faced gypsum board, and provides the paper-faced gypsum board with excellent humidity regulating performance and board mechanical performance.

Specifically, the present application provides a gypsum board comprising: 80-98 parts of gypsum powder and 1-10 parts of silica sol.

In the present application, the gypsum board may include 87 to 98 parts by weight of gypsum powder and 1 to 10 parts by weight of silica sol.

In the application, the gypsum board can also comprise 0.1 to 1.5 weight parts of binding agent, 0.1 to 0.7 weight part of water reducing agent, 0.1 to 2 weight parts of rubber powder and 0 to 0.08 weight part of water retention agent.

In the application, the gypsum board can also comprise 0.1 to 1.5 weight parts of binding agent, 0.1 to 0.7 weight part of water reducing agent, 0.1 to 1.5 weight parts of rubber powder and 0 to 0.05 weight part of water retention agent.

In the present application, the gypsum board may include 80-98 parts by weight of gypsum powder, 1-10 parts by weight of silica sol, 0.1-1.5 parts by weight of binder, 0.1-0.7 parts by weight of water reducing agent, 0.1-2 parts by weight of rubber powder and 0-0.08 parts by weight of water retaining agent.

In the present application, the gypsum board may include 80-98 parts by weight of gypsum powder, 1-10 parts by weight of silica sol, 0.1-1.5 parts by weight of binder, 0.1-0.7 parts by weight of water reducing agent, 0.1-1.5 parts by weight of rubber powder and 0-0.05 parts by weight of water retaining agent.

In the present application, the gypsum board may include 87 to 98 parts by weight of gypsum powder, 1 to 10 parts by weight of silica sol, 0.1 to 1.5 parts by weight of binder, 0.1 to 0.7 part by weight of water reducing agent, 0.1 to 2 parts by weight of rubber powder and 0 to 0.08 part by weight of water retaining agent.

In the present application, the gypsum board may include 87 to 98 parts by weight of gypsum powder, 1 to 10 parts by weight of silica sol, 0.1 to 1.5 parts by weight of binder, 0.1 to 0.7 part by weight of water reducing agent, 0.1 to 1.5 parts by weight of rubber powder and 0 to 0.05 part by weight of water retaining agent.

In the present application, the gypsum board may be composed of 80 to 98 parts by weight of gypsum powder and 1 to 10 parts by weight of silica sol.

In the present application, the gypsum board may be composed of 87 to 98 parts by weight of gypsum powder and 1 to 10 parts by weight of silica sol.

In the application, the gypsum board can be composed of 80-98 parts by weight of gypsum powder, 1-10 parts by weight of silica sol, 0.1-1.5 parts by weight of binder, 0.1-0.7 part by weight of water reducing agent, 0.1-2 parts by weight of rubber powder and 0-0.08 part by weight of water retention agent.

In the present application, the gypsum board may be composed of 80-98 parts by weight of gypsum powder, 1-10 parts by weight of silica sol, 0.1-1.5 parts by weight of binder, 0.1-0.7 parts by weight of water reducing agent, 0.1-1.5 parts by weight of rubber powder and 0-0.05 parts by weight of water-retaining agent.

In the application, the gypsum board can be composed of 87-98 parts by weight of gypsum powder, 1-10 parts by weight of silica sol, 0.1-1.5 parts by weight of binder, 0.1-0.7 part by weight of water reducing agent, 0.1-2 parts by weight of rubber powder and 0-0.08 part by weight of water retention agent.

In the present application, the gypsum board may be composed of 87 to 98 parts by weight of gypsum powder, 1 to 10 parts by weight of silica sol, 0.1 to 1.5 parts by weight of binder, 0.1 to 0.7 part by weight of water reducing agent, 0.1 to 1.5 parts by weight of rubber powder and 0 to 0.05 part by weight of water retaining agent.

In the present application, the binder may be selected from any one or more of modified potato starch, modified tapioca starch, modified sorghum starch and modified corn starch;

the water reducing agent is selected from any one or more of Melflux5691F, 5581F, 2651F and 4930F;

the rubber powder is selected from

5010N、

5011L and

5111L;

the water retaining agent is selected from cellulose water retaining agents selected from any one or more of hydroxypropyl methylcellulose, hydroxyethyl cellulose, hydroxymethyl cellulose, preferably selected from any one or more of akysnobel CST324, akysnobel CST481, akysnobel CCA328, dow METHOCEL Hythylcellulose, bayer MKX40000PF01, bayer MKX60000PF 15.

In the gypsum board of the application, the gypsum crystals have uniform size, the original fibrous, columnar and flaky crystals form crystal groups with similar or consistent directions and tightly form a group, and one or more layers of amorphous compact silica sol nanometer films cover the surfaces of the gypsum crystals. The silica sol changes the process of hydration of the semi-hydrated gypsum to the dihydrate gypsum, the lapping mode among crystals and the surface appearance.

The application also provides a preparation method of the gypsum board, which comprises the following steps: mixing gypsum powder with silica sol.

In the present application, the preparation method may include:

mixing gypsum powder, silica sol, starch, a water reducing agent, rubber powder and a water-retaining agent.

In the present application, the preparation method may include:

(1) sieving gypsum powder, and uniformly mixing the gypsum powder with a water reducing agent;

(2) testing the standard consistency spread of the mixture obtained in the step (1) to determine the water consumption for the standard consistency of the landplaster;

(3) weighing the silica sol solution and water according to the water consumption of the standard consistency, and mixing;

(4) stirring the mixture obtained in the step (1), a binder, rubber powder, a water-retaining agent and the silica sol solution obtained in the step (3) to prepare slurry;

(5) flatly paving the slurry prepared in the step (4) on paper, covering the paper before the slurry is initially set, and applying pressure;

(6) and demolding after final setting is finished, and drying.

In this application, in step (1), the gypsum may be sieved through an 80-100 mesh sieve.

In the present application, the standard thickness spread of construction gypsum is determined according to GB/T17669.3-1999 standard.

In this application, the sum of the mass of water in the silica sol solution and the weighed water is equal to the water consumption for a standard consistency.

In the present application, in the step (3), SiO in the silica sol solution₂May be in the range of 29 wt% to 42 wt%.

In the preparation method of the present application, in the step (6), drying may be performed at 150 ℃ to 170 ℃ for 40min to 80 min.

In the preparation method of the present application, in the step (6), drying may be performed at 100 ℃ to 120 ℃ for 30min to 40 min.

In the preparation method of the present application, in step (6), drying may be performed at 40 ℃ to 50 ℃ to a constant weight.

In the preparation method, in the step (6), the mixture can be dried at 150-170 ℃ for 40-80 min, at 100-120 ℃ for 30-40 min, and then dried at 40-50 ℃ to constant weight.

In this application, in step (6), the drying is continued at 150 ℃ to 170 ℃ for 40min to 80min, at 100 ℃ to 120 ℃ for 30min to 40min, and then at 40 ℃ to 50 ℃ to constant weight.

Compared with the existing gypsum board, the gypsum board has the advantages that the moisture absorption performance and the moisture desorption performance are improved, and the strength is increased; the fire resistance is improved.

Additional features and advantages of the application will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the application. The objectives and other advantages of the application may be realized and attained by the structure particularly pointed out in the written description and claims hereof.

Drawings

The accompanying drawings are included to provide a further understanding of the claimed subject matter and are incorporated in and constitute a part of this specification, illustrate embodiments of the subject matter and together with the description serve to explain the principles of the subject matter and not to limit the subject matter.

FIG. 1 is a graph showing moisture absorption curves of gypsum boards prepared in examples 1 to 2 of the present application and a general gypsum board, wherein a circle is the moisture absorption curve of example 1, a triangle is the moisture absorption curve of example 2, and a square is the moisture absorption curve of a comparative example.

FIG. 2 is a graph of relative humidity versus time for gypsum board made in example 1 of the present application and for ordinary gypsum board, where the circles are the relative humidity versus time curves for example 1 and the squares are the relative humidity versus time curves for the comparative examples.

FIG. 3 is an SEM (scanning electron microscope) image of a gypsum board prepared in example 2 of the present application.

Fig. 4 is an SEM image of a gypsum board prepared in a comparative example.

Fig. 5 is a transmission electron microscope image of a gypsum board core prepared in example 2 of the present application.

FIG. 6 is a transmission electron microscope image of a silica sol.

Detailed Description

Hereinafter, embodiments of the present application will be described in detail to make objects, technical solutions and advantages of the present application more apparent. It should be noted that the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict.

The raw materials and reagents used in the following examples are all common commercial products unless otherwise specified. Modified corn starch was purchased from a Zhao quan Ying starch factory; the silica sol solution was purchased from Hibiscus rosa-sinensis refining processing Co., Ltd., model NS-13.

In the examples, the SEM used was an environmental scanning electron microscope FEI Quanta FEG 250 type, and the acceleration voltage was 20 kV; the transmission electron microscope was Tecnai G2F 30 manufactured by FEI corporation, USA, and the accelerating voltage was 300 kV.

Example 1

1000g of gypsum powder is sieved by a 80-mesh sieve. 1000g of gypsum powder and 2g of water reducing agent (Melflux 5691F, manufactured by BASF, China) were mixed uniformly, and test mixing was performedThe water consumption for the standard consistency of the mixed powder is determined according to the spreading degree of the mixed powder of 180 mm. Sieving gypsum, water reducing agent, modified corn starch 6g, and glue powder

5010N)10g and cellulose (Bayer MKX40000PF01)0.5 g; weighing 20g of silica sol solution with the concentration of 29 weight percent; water is taken out according to the standard consistency by weighing. And (3) putting the silica sol into water, uniformly stirring, pouring the uniformly mixed mixture of the gypsum, the water reducing agent, the starch, the rubber powder and the cellulose into the water, and stirring together to prepare slurry. The prepared slurry is flatly laid on lower paper, upper paper is covered before the slurry is initially set, and the thickness of the plate is 9.5 mm. And (3) demolding after final setting is finished, and placing the plate in a drying oven for drying, drying at 160 ℃ for 1 hour, drying at 110 ℃ for 0.5 hour, and then drying at 45 ℃ to constant weight.

Example 2

1000 grams of landplaster was sieved through an 80 mesh sieve. 1000g of gypsum powder and 2g of water reducing agent (Melflux 5691F, manufactured by BASF corporation) were uniformly mixed, and the water consumption for the standard consistency of the mixed powder was determined by measuring the spreadability of the mixed powder to be 180 mm. Sieving gypsum powder, 2g of water reducing agent, 6g of modified corn starch and rubber powder (a)

5010N)10g and 0.5g of cellulose (Bayer MKX40000PF01) are mixed uniformly; weighing 60g of silica sol solution with the concentration of 29 weight percent; water was used at standard consistency and weighed 608ml of water. And (3) putting the silica sol into water, uniformly stirring, pouring the uniformly mixed mixture of the gypsum powder, the water reducing agent, the starch, the rubber powder and the cellulose into the water, and stirring together to prepare slurry. The prepared slurry is flatly laid on lower paper, upper paper is covered before the slurry is initially set, and the thickness of the plate is 9.5 mm. And (3) demolding after final setting is finished, and placing the plate in a drying oven for drying, drying at 160 ℃ for 1 hour, drying at 110 ℃ for 0.5 hour, and then drying at 45 ℃ to constant weight.

Example 3

Example 3 the procedure was the same as in example 1 except that no water reducing agent was added to the formulation.

Comparative example

1000g of gypsum powder is sieved by a 80-mesh sieve. The standard consistency of the mixed flour was determined by measuring the spread of the landplaster to 180mm using water at a rate of 0.65. Uniformly mixing 6g of sieved gypsum and modified corn starch; water was used at a standard consistency and weighed to 650 ml. Then pouring the uniformly mixed gypsum and starch mixture into water, stirring the mixture together, and preparing slurry. The prepared slurry is flatly laid on lower paper, upper paper is covered before the slurry is initially set, and the thickness of the plate is 9.5 mm. And (3) demolding after final setting is finished, and placing the plate in a drying oven for drying, drying at 160 ℃ for 1 hour, drying at 110 ℃ for 0.5 hour, and then drying at 45 ℃ to constant weight.

Performance testing

The gypsum boards prepared in the above examples were tested for their performance according to GB/T17669.3-1999 standard. The results are reported in Table 1.

TABLE 1 Properties of gypsum boards prepared in examples 1-2 and comparative examples

Item	Comparative example	Example 1	Example 2	Example 3
					Absolutely dry and fracture resistant MPa	7.4	9.9	10.8	7.9
Absolute dry pressure resistance MPa	21.2	25.8	28.9	23.4
					Transverse rupture load MPa	180	290	320	220
Longitudinal breaking load MPa	362	530	611	431

And (3) testing the fire resistance: the gypsum boards prepared in examples 1-2 and comparative examples were tested for fire stability according to the fire stability test method in the Standard GB11979-89 for fire-resistant paper-faced gypsum boards. The results are reported in Table 2.

TABLE 2 fire stability of the gypsum boards prepared in examples 1-2 and comparative examples

The moisture absorption performance of different gypsum boards was tested according to the GB/T20312-2006 standard, and the results are shown in FIG. 1.

The gypsum test blocks (40mm by 160mm) were placed in water and the water absorption of the test blocks was measured over time and the results are shown in table 3.

TABLE 3 Water absorption of gypsum boards prepared in examples 1-2 and comparative examples

The gypsum boards prepared in example 2 and comparative example were observed under a scanning electron microscope, as shown in fig. 3 and 4. As can be seen from fig. 3-6, the gypsum in fig. 4 is composed of fine, irregular, fibrous, columnar and flaky crystal grains, the combination between the crystal grains is loose, and the centers of a plurality of groups of crystal grains are distributed with cavities (generated after excessive mixing water is evaporated during the drying process of the gypsum board); the gypsum crystal grains in fig. 3 are ordered compared with fig. 4, the size is uniform (the length is about 10 um), and a plurality of groups of fibrous and columnar crystal grains are close to or consistent in direction and are tightly combined into a group. The silica sol particles in the silica sol solution (after evaporation of water from the silica sol solution, the solid particles are observed under a transmission electron microscope, see fig. 6) are nano-sized (particles are uniform in size, and basically all between 20 nm and 30 nm), and the nano-particles are attached to the surface of the gypsum crystals during the hydration of the gypsum to form one or more dense films, as shown in fig. 5.

Although the embodiments disclosed in the present application are described above, the descriptions are only for the convenience of understanding the present application, and are not intended to limit the present application. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims.

Claims

1. A gypsum board, the gypsum board comprising: 80-98 parts of gypsum powder, 1-10 parts of silica sol solution, 0.1-1.5 parts of binder, 0.1-0.7 part of water reducing agent, 0.1-2 parts of rubber powder and 0-0.08 part of water-retaining agent, wherein SiO in the silica sol solution₂In the range of 29 wt% to 42 wt%.

2. The gypsum board of claim 1 wherein the gypsum powder is 87 to 98 parts by weight of gypsum powder.

3. The gypsum board of claim 1 or 2,

the binder is selected from any one or more of corn modified starch, modified potato starch, cassava modified starch and sorghum modified starch;

the water reducing agent is selected from any one or more of Melflux5691F, Melflux5581F, Melflux2651F and Melflux 4930F;

the rubber powder is selected from any one or more of VINNAPAAS 5010N, VINNAPAS 5011L and VINNAPAS 5111L;

the water retaining agent is selected from cellulose water retaining agents, and the cellulose water retaining agents are selected from any one or more of hydroxypropyl methyl cellulose, hydroxyethyl cellulose and hydroxymethyl cellulose.

4. A method of making the gypsum board of any one of claims 1-3, the method of making comprising:

(6) and demolding after final setting is finished, and drying.

5. The production method according to claim 4, wherein, in the step (1), the gypsum is sieved with a sieve of 80 to 100 meshes.

6. The preparation method according to claim 4, wherein, in the step (6), the drying is continued at 150 ℃ to 170 ℃ for 40min to 80min, at 100 ℃ to 120 ℃ for 30min to 40min, and then at 40 ℃ to 50 ℃ to constant weight.