Damp deformation resistant gypsum board and preparation method thereof

Abstract

The invention relates to the field of gypsum boards, and discloses an anti-damp deformation gypsum board, which comprises the following materials in square meters: 4500-5500 g / m < 2 > of desulfurized gypsum cooked powder, 8-10 g / m < 2 > of modified starch, 2500-3000 g / m < 2 > of water, 3-6 g / m < 2 > of sodium trimetaphosphate, 1-20 g / m < 2 > of naphthalene water reducer, 1-3 g / m < 2 > of boric acid, and 1-2 g / m < 2 > of tartaric acid. Wherein the modified starch can absorb sodium ions in the water, so that the content of the sodium ions in each square meter of the gypsum board is reduced to 600ppm; the invention further discloses a preparation method of the damp-deformation-resistant gypsum board. While the strength and environmental protection performance of the gypsum board are guaranteed, moisture absorption expansion of the gypsum board in a humid environment is effectively inhibited, and the damp deflection deformation of the board is smaller than 2 mm in the environment with the temperature being 25-30 DEG C and the humidity being 50%-90%.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of gypsum board, in particular to an anti-moisture deformation gypsum board and a preparation method thereof. BACKGROUND

[0002] Gypsum board is a kind of building material with light weight, fire resistance and excellent sound insulation performance, which is widely used in indoor decoration and partition wall fields. However, the traditional gypsum board is prone to deformation under humid environment, which leads to problems such as warping and cracking of the board, seriously affecting its performance and aesthetics.

[0003] Part of the reason for its moisture deformation comes from the use of water in gypsum board production, which requires a large amount of water. However, ordinary water contains sodium ions, which can react with calcium sulfate in gypsum to form sodium sulfate and calcium carbonate, causing changes in the crystal structure of gypsum. This transformation weakens the connection strength of the gypsum board crystals, making them prone to deformation under moisture or external force. Therefore, sodium ions significantly reduce the performance stability of gypsum board by changing the crystal structure of gypsum, weakening the adhesion and adjusting the moisture absorption.

[0004] Therefore, it is necessary to strictly control the content of sodium ions in the production of gypsum board to ensure its service life and safety. Distilled water can be used for production, but the price of distilled water is higher than that of ordinary tap water, resulting in high production cost. In the prior art, methods such as adding waterproof agent and increasing the density of gypsum board are used to improve the anti-moisture deformation ability of gypsum board, but these methods often have high cost and may affect other properties of gypsum board to some extent, and also increase the VOC content in gypsum board, thereby reducing the environmental performance of gypsum board. SUMMARY

[0005] The purpose of the present application is to provide an anti-moisture deformation gypsum board and a preparation method thereof to solve the technical problem of how to improve the anti-moisture deformation ability of gypsum board in the prior art.

[0006] To solve the above technical problems, the present application specifically provides the following technical solutions:

[0007] The present application provides an anti-moisture deformation gypsum board, which comprises desulfurized gypsum powder 4500-5500 g / square meter, modified starch 8-10 g / square meter, water 2500-3000 g / square meter, sodium trimetaphosphate 3-6 g / square meter, naphthalene-based water reducing agent 1-20 g / square meter, boric acid 1-3 g / square meter, and tartaric acid 1-2 g / square meter, in terms of the mass content of materials per square meter of the gypsum board.

[0008] The modified starch can absorb sodium ions in the water, so that the content of sodium ions in the gypsum board per square meter is reduced to 600 ppm.

[0009] As a preferred scheme of the present application, the gypsum board comprises desulfurized gypsum powder 5000g / m2, modified starch 10g / m2, water 2500g / m2, sodium trimetaphosphate 5g / m2, naphthalene water-reducing agent 1-20g / m2, boric acid 2g / m2, and tartaric acid 1g / m2, in terms of the mass content of the material per square meter of the gypsum board.

[0010] As a preferred scheme of the present application, the modified starch is a mixture of irradiated starch and carbide powder.

[0011] As a preferred scheme of the present application, the desulfurized gypsum powder has a fineness of 200 mesh.

[0012] The present application also provides a preparation method of the moisture-resistant deformation-resistant gypsum board.

[0013] S100, preparing modified starch, adding the modified starch into water to obtain intermediate water;

[0014] S200, adding desulfurized gypsum powder, sodium trimetaphosphate, naphthalene water-reducing agent, boric acid, and tartaric acid into the intermediate water in sequence, stirring uniformly to form a slurry;

[0015] S300, pouring the slurry into a mold, and forming, drying, and cutting to obtain the moisture-resistant deformation-resistant gypsum board.

[0016] As a preferred scheme of the present application, in step S100, the preparation step of the modified starch is as follows:

[0017] S101, adding soluble starch into a small amount of deionized water and anhydrous ethanol, heating and gelatinizing to obtain starch paste;

[0018] S102, adding calcium carbonate powder into the starch paste, mixing uniformly to make the starch paste wrap the surface of the calcium carbonate powder, drying, and grinding to obtain precursor particles;

[0019] S103, under ultraviolet irradiation, heating and treating the precursor particles by microwave until the starch is slightly carbonized on the surface of the calcium carbonate powder to obtain the modified starch.

[0020] As a preferred scheme of the present application, in the step S101, the mass ratio of the soluble starch to the calcium carbonate powder is 2:1.

[0021] As a preferred scheme of the present application, the soluble starch is cassava starch or modified corn starch.

[0022] As a preferred scheme of the present application, in the step S102, the drying temperature is 75-85 DEG C, and the drying time is 10-12h.

[0023] As a preferred scheme of the present application, in the step S103, the power of the ultraviolet is 175W, the wavelength of the microwave is 2450MHz, and the heating time is 10-20min.

[0024] Compared with the prior art, the present application has the following beneficial effects:

[0025] The present application effectively inhibits the moisture absorption and expansion of the gypsum board in a humid environment by adding additives such as modified starch, sodium trimetaphosphate, boric acid and tartaric acid, so that the deflection deformation of the board is less than 2mm in a 25-30 DEG C, 50%-90% humidity environment;

[0026] The present application discloses a mixed starch additive, which can adsorb sodium ions and other divalent metal ions in the gypsum board slurry system by using irradiation modified starch and mixed denatured starch with carbonide as a precursor, prevents the sodium ions and other divalent metal ions from reacting with calcium sulfate in the gypsum, ensures the connection strength of the metal inside the gypsum board, and improves the moisture resistance of the gypsum board.

[0027] The present application realizes one-step production of irradiation starch and carbonide powder in the mixed denatured starch by microwave and ultraviolet radiation, saves production time, and speeds up the production rhythm. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only exemplary, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of the provided drawings.

[0029] Figure 1 The present application provides a flowchart of the preparation method of the moisture-resistant deformation gypsum board. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application will be described clearly and completely in the following with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0031] The application provides an anti-moisture deformation gypsum board, which comprises, in terms of the mass content of materials per square meter of the gypsum board, 4500-5500 g / square meter of desulfurized gypsum powder, 8-10 g / square meter of modified starch, 2500-3000 g / square meter of water, 3-6 g / square meter of sodium trimetaphosphate, 1-20 g / square meter of naphthalene water-reducing agent, 1-3 g / square meter of boric acid and 1-2 g / square meter of tartaric acid.

[0032] The modified starch can absorb sodium ions in water, so that the content of sodium ions in the gypsum board per square meter is reduced to 600 ppm.

[0033] The water is tap water.

[0034] The application aims to provide a production formula of the anti-moisture deformation gypsum board, which can make the gypsum board have excellent anti-deformation performance in a humid environment, while keeping the light weight, fireproof and other excellent properties of the gypsum board by optimizing the material ratio and adding specific additives.

[0035] The application adds additives such as sodium trimetaphosphate, boric acid and tartaric acid, effectively inhibits the moisture absorption and expansion of the gypsum board in a humid environment, so that the moisture deflection deformation of the board is less than 2 mm in an environment of 25-30 degrees Celsius and 50%-90% humidity. The gypsum board produced by the formula keeps the excellent properties of light weight, fireproof, sound insulation and the like, while having high strength and toughness. The raw materials used in the application are widely available and low in price, and the application is easy to industrialize.

[0036] The modified starch, i.e. modified starch, can absorb heavy metal ions or other divalent ions in the system, thereby reducing the reaction between gypsum and ions, the formation of cavities between the gypsum board and the paper surface, and improving the bonding performance between the gypsum board and the surface paper, thereby improving the anti-moisture capacity of the gypsum board, preventing the separation between the core and the surface paper after the gypsum board is wetted, prolonging the service life of the gypsum board and making the gypsum board have long-term supporting performance.

[0037] Specifically, in the preferred embodiment, the gypsum board comprises, in terms of the mass content of materials per square meter of the gypsum board, 5000 g / square meter of desulfurized gypsum powder, 10 g / square meter of modified starch, 2500 g / square meter of water, 5 g / square meter of sodium trimetaphosphate, 1-20 g / square meter of naphthalene water-reducing agent, 2 g / square meter of boric acid and 1 g / square meter of tartaric acid.

[0038] The above-mentioned materials are easy to obtain and can be widely applied to the production of gypsum boards.

[0039] In particular, ordinary modified starch cannot quickly combine with sodium ions, while the carbide can adsorb sodium ions to a certain extent. Specifically, the modified starch is a mixture of irradiated starch and carbide powder.

[0040] The modified starch can reduce the sodium ion content in the gypsum board to 600 ppm or less.

[0041] The irradiated starch is a kind of starch treated by ultraviolet light after gelatinization, which has good adsorption capacity for metal ions in liquid, thereby reducing the adsorption of divalent metals such as Pb(II), Cu(II) and the like to make them into non-free ions, preventing them from reacting with calcium sulfate in the gypsum board, improving the connection ability in the gypsum board, and also improving the connection ability between the core of the gypsum board and the cover paper.

[0042] The carbide powder is a kind of substance carbonized after baking after gelatinization with starch as a precursor, which has better adsorption capacity, can not only adsorb sodium ions in tap water, but also can adsorb other organic matters in tap water, prevent sodium ions from reacting with calcium sulfate in gypsum, improve the connection ability in the gypsum board, improve the connection ability in the gypsum board, thereby improve the moisture resistance of the gypsum board.

[0043] It can be seen that the modified starch mixed by the irradiation modified starch and the carbide with starch as a precursor can adsorb sodium ions and other divalent metal ions in the gypsum slurry system, prevent sodium ions and other divalent metal ions from reacting with calcium sulfate in gypsum, ensure the connection strength of the metal inside the gypsum board, improve the moisture resistance, and the modified starch has sufficient safety and is cheap and easy to obtain.

[0044] In the disclosed embodiment of the application, the fineness of the desulfurized gypsum powder is 200 mesh.

[0045] In the disclosed embodiment of the application, the water-reducing rate of the naphthalene-based water-reducing agent is not less than 15%.

[0046] As shown in the figure, the application further provides a preparation method of the moisture-resistant deformed gypsum board, comprising the following steps: Figure 1

[0047] S100, preparing modified starch, adding the modified starch into water to obtain a prepared water, which needs to be precipitated for 10-20 h, so that the modified starch can adsorb sodium ions, other metal ions and even organic matters in tap water;

[0048] S200, sequentially adding desulfurized gypsum powder, sodium trimetaphosphate, naphthalene-based water-reducing agent, boric acid and tartaric acid into the prepared water, stirring uniformly to form a slurry (or the desulfurized gypsum powder, sodium trimetaphosphate, naphthalene-based water-reducing agent, boric acid and tartaric acid can be mixed uniformly first, then added into the prepared water, and the specific steps are not limited) ;

[0049] ​S300, pour the slurry into the mold, shape, dry, cut, and obtain the anti-moisture deformation gypsum board.

[0050] In step S300, the shaping mode of the gypsum board is the prior art, and the existing shaping scheme can be used.

[0051] In the embodiment, the modified starch is a mixture of irradiated starch and carbide powder, and the following preparation scheme can be used:

[0052] The edible starch is gelatinized, the gelatinized starch is irradiated by a UV lamp, dried, ground, and modified starch is obtained.

[0053] The preparation scheme of the carbide powder is as follows:

[0054] The starch is gelatinized by using a mixture of water and ethanol, dried after gelatinization, and baked at 600-1000 DEG C for a long time until it is denatured, and the carbide powder is obtained.

[0055] Although the performance of the modified starch in the gypsum board is good, and the amount is small, the above preparation method is relatively complicated, resulting in high cost of the preparation of the modified starch.

[0056] In order to further reduce the preparation cost of the gypsum board and speed up the production rhythm of the gypsum board accessories, the application further provides a production method of modified starch:

[0057] The preparation steps of the modified starch are as follows:

[0058] S101, soluble starch is added to a small amount of deionized water and anhydrous ethanol, heated and gelatinized, and starch paste is obtained;

[0059] S102, calcium carbonate powder is added to the starch paste, mixed uniformly, so that the starch paste is wrapped on the surface of the calcium carbonate powder, dried at a temperature of 75-85 DEG C for 10-12h, and ground to obtain precursor particles;

[0060] S103, under the irradiation of 175W ultraviolet light, the precursor particles are heated and treated by microwave, the wavelength of the microwave is 2450MHz, the heating time is 10-20min, until the starch is slightly carbonized on the surface of the calcium carbonate powder, and the modified starch containing a small amount of irradiated starch and carbide powder is obtained.

[0061] The soluble starch can be cassava starch or modified corn starch, and the cassava starch or modified corn starch has a relatively advantageous price.

[0062] In step S101, according to the mass ratio, the soluble starch: calcium carbonate powder is 2:1.

[0063] The present application realizes one-step production of irradiated starch and carbide powder in mixed modified starch through microwave and ultraviolet radiation, saves production time and speeds up the production rhythm.

[0064] The carbide powder is a kind of particle taking soluble starch as single carbon source and calcium carbonate as hard template, after uniform stirring, the soluble starch can be well wrapped on the surface of the calcium carbonate, so that in the subsequent microwave radiation process, part of the soluble starch is modified, most of the soluble starch is carbonized into ultrathin carbon, and the calcium carbonate is carbonated calcium carbonate, and the hard template releases CO2 when generating calcium carbonate, and the release of CO2 generates a large number of micropore channels on the surface of the ultrathin carbon and the irradiated starch, and the micropore channels provide attachment sites for adsorbing sodium ions and other substances.

[0065] The carbide powder provided by the present application has a large specific surface area, a large interlayer distance and inherent O - Heteroatoms, these characteristics provide a large number of active sites for reversible adsorption / desorption of sodium ions.

[0066] The present application provides a hard carbon negative electrode material with high capacity for storing sodium ions by the method of ultraviolet radiation and microwave heating.

[0067] The following further provides examples to illustrate the performance of the gypsum board:

[0068] 1. Preparation of modified starch

[0069] (1) 10g of cassava starch was added to 10g of deionized water and 2g of anhydrous ethanol, and the paste was heated at 80℃ to obtain a starch paste;

[0070] (2) The calcium carbonate was ground, 5g of calcium carbonate powder was added to the starch paste, and the mixture was uniformly mixed so that the starch paste wrapped the surface of the calcium carbonate powder, and was dried at a temperature of 80℃ for 10h, and was ground to obtain precursor particles;

[0071] (3) The precursor particles were heated and treated by microwave under the irradiation of 175W ultraviolet light, the wavelength of the microwave was 2450MHz, and the heating time was 15min, until the starch was slightly carbonized on the surface of the calcium carbonate powder, to obtain modified starch containing a small amount of irradiated starch and carbide powder.

[0072] Specifically, according to the mass ratio, the carbide powder: irradiated starch in the modified starch is 112.5:1.

[0073] 2. Preparation of gypsum board

[0074] (1) 10g of modified starch was added to 2500g of tap water;

[0075] (2) 5000g desulfurized gypsum powder, 5g sodium trimetaphosphate, 5g naphthalene water reducing agent, 2g boric acid and 1g tartaric acid were mixed uniformly, and then mixed with the material in step (1) to form a slurry;

[0076] (3) The slurry was poured into a mold, and then formed, dried and cut to obtain the moisture-resistant deformation gypsum board.

[0077] The denatured starch reduces the sodium ion content in the slurry to 450ppm.

[0078] Comparative Example 1:

[0079] The preparation conditions are the same as those in Example 1, except that no denatured starch is added.

[0080] The performance of Example 1 is characterized as follows, and the results are shown in Table 1.

[0081]

[0082] As shown in Table 1, the moisture resistance of the gypsum board of Example 1 is better than that of the gypsum board of Comparative Example 1 (without adding denatured starch) after long-term placement in a relatively humid environment. The gypsum board produced by the formula maintains the excellent properties of light weight, fire resistance, sound insulation, etc., and has high strength and toughness.

[0083] The moisture-resistant deformation gypsum board production formula provided by the present application effectively solves the problem of easy deformation of traditional gypsum board in a humid environment by optimizing the ratio of raw materials and adding specific additives. The production raw materials are cheap and easy to obtain, the amount of denatured starch additive is small, the production method is relatively simple, and the formula has a broad market application prospect.

[0084] The above examples are only exemplary embodiments of the present application and do not limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art can make various modifications or equivalent replacements to the present application within the spirit and protection scope of the present application, and such modifications or equivalent replacements are also regarded as falling within the protection scope of the present application.

Claims

1. A moisture resistant deformation resistant gypsum board, characterized by, The material mass content per square meter of the gypsum board includes desulfurization gypsum powder 4500-5500 g / square meter, modified starch 8-10 g / square meter, water 2500-3000 g / square meter, sodium trimetaphosphate 3-6 g / square meter, naphthalene water reducing agent 1-20 g / square meter, boric acid 1-3 g / square meter, and tartaric acid 1-2 g / square meter. The modified starch can absorb sodium ions in the water, so that the sodium ion content in the gypsum board per square meter is reduced to 600 ppm.

2. A moisture resistant deformation resistant gypsum board according to claim 1, characterized in that The material mass content per square meter of the gypsum board includes desulfurization gypsum powder 5000 g / square meter, modified starch 10 g / square meter, water 2500 g / square meter, sodium trimetaphosphate 5 g / square meter, naphthalene water reducing agent 1-20 g / square meter, boric acid 2 g / square meter, and tartaric acid 1 g / square meter.

3. A moisture resistant deformation resistant gypsum board according to claim 1, wherein The modified starch is a mixture of irradiated starch and carbide powder.

4. A moisture resistant deformation resistant gypsum board according to claim 1, wherein The fineness of the desulfurization gypsum powder is 200 mesh.

5. A method of producing a moisture resistant deformation resistant gypsum board according to any one of claims 1 to 4, characterized in that, The method comprises the following steps: S100, preparing modified starch, adding the modified starch into water to obtain intermediate water; S200, sequentially adding desulfurization gypsum powder, sodium trimetaphosphate, naphthalene water reducing agent, boric acid, and tartaric acid into the intermediate water, stirring uniformly to form a slurry; S300, pouring the slurry into a mold, and forming, drying, and cutting to obtain the moisture-resistant deformation gypsum board.

6. A method of manufacturing a moisture resistant deformation resistant gypsum board according to claim 5, characterized in that, In step S100, the preparation step of the modified starch is as follows: S101, adding soluble starch into a small amount of deionized water and anhydrous ethanol, heating and gelatinizing to obtain starch paste; S102, adding calcium carbonate powder into the starch paste, mixing uniformly, so that the starch paste wraps the surface of the calcium carbonate powder, drying, and grinding to obtain precursor particles; S103, under ultraviolet irradiation, heating the precursor particles by microwave until the starch is slightly carbonized on the surface of the calcium carbonate powder to obtain the modified starch.

7. A method of manufacturing a moisture resistant deformation resistant gypsum board according to claim 6, characterized in that, In step S101, the mass ratio of the soluble starch to the calcium carbonate powder is 2:

1.

8. A method of manufacturing a moisture resistant deformation resistant gypsum board according to claim 7, characterized in that, The soluble starch is cassava starch or modified corn starch.

9. A method of manufacturing a moisture resistant deformation resistant gypsum board according to claim 6, characterized in that, In step S102, the drying temperature is 75-85°C, and the drying time is 10-12 h.

10. A method of manufacturing a moisture resistant deformation resistant gypsum board according to claim 1, characterized in that, In step S103, the power of the ultraviolet light is 175 W, the wavelength of the microwave is 2450 MHz, and the heating time is 10-20 min.

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