Gypsum self-leveling agent for adsorbing and decomposing formaldehyde and application of gypsum self-leveling agent

Abstract

The invention belongs to the technical field of gypsum self-leveling, and particularly discloses gypsum self-leveling capable of adsorbing and decomposing formaldehyde. According to the gypsum self-leveling agent, the inherent high porosity of the gypsum self-leveling agent is utilized, and the dual-component improvement of the activated carbon and the decomposition component is added, so that the gypsum self-leveling agent can be decomposed after adsorbing formaldehyde, the harm of the formaldehyde can be eradicated, and the defect that in the prior art, activated carbon is adopted as an adsorbent, and desorption can be performed after adsorption saturation is avoided. And meanwhile, the gypsum in the gypsum self-leveling process releases heat during curing, so that a heat source can be provided for the formaldehyde decomposition reaction, and the formaldehyde decomposition reaction is promoted. In addition, the activated carbon can also promote the setting and hardening speed in the later period of gypsum self-leveling, and the airing period after gypsum self-leveling construction is shortened. The invention also provides application of the gypsum self-leveling material, and the gypsum self-leveling material is used as a ground leveling layer material.

Description

Technical Field

[0001] The invention belongs to the technical field of gypsum self-leveling, and in particular relates to a gypsum self-leveling capable of absorbing and decomposing formaldehyde, and application thereof. Background Art

[0002] Formaldehyde is a colorless, pungent gas. Indoor formaldehyde mainly comes from glue decoration materials and furniture. Formaldehyde is a common environmental allergen. Some people will develop allergic dermatitis after exposure to formaldehyde. Long-term exposure to formaldehyde may lead to respiratory diseases such as chronic pharyngitis and chronic bronchitis. Formaldehyde can interfere with the normal functioning of the human immune system and increase the risk of cancer, especially nasopharyngeal cancer and leukemia.

[0003] At present, common formaldehyde treatment methods such as opening windows for ventilation or plant purification have limited formaldehyde absorption and weak purification capabilities. It is difficult to remove formaldehyde in corners with poor ventilation or in furniture and decoration materials. In order to improve the adsorption effect, the method of using activated carbon to adsorb formaldehyde may release the adsorbed formaldehyde again after reaching adsorption saturation, so it cannot achieve the effect of eradicating formaldehyde.

[0004] At the same time, gypsum self-leveling is a new type of product in China. It is a material made of gypsum as the base material, composited with cement, fillers and admixtures. It has good fluidity, dimensional stability and comfort. It can effectively solve the problems of hollowing, cracking and poor flatness of fine stone concrete leveling layer. It can meet the flatness requirements of the ground for laying wooden floors, floor glue and other floor materials. It is the best choice for indoor floor leveling.

[0005] Gypsum self-leveling is the most widely used material for interior decoration. If gypsum self-leveling can be used to deal with the formaldehyde pollution problem in interior decoration, it will provide a new direction for the innovation of interior decoration technology. Summary of the invention

[0006] In order to solve the problems of limited absorption, weak purification ability, and easy desorption after adsorption saturation in conventional formaldehyde treatment methods in the prior art, and in combination with the characteristics of large-scale application of gypsum self-leveling, the inventors of the present invention have proposed a new gypsum self-leveling material that can absorb and decompose formaldehyde based on the long-term research on gypsum self-leveling. The gypsum self-leveling uses its higher porosity and improves its composition to decompose after adsorbing formaldehyde, which can eliminate the harm of formaldehyde. In addition, the activated carbon can also promote the coagulation and hardening speed of the gypsum self-leveling in the later stage, and shorten the air-drying period after the gypsum self-leveling construction.

[0007] The present invention specifically adopts the following technical solutions:

[0008] A gypsum self-leveling material that absorbs and decomposes formaldehyde, comprising the following components in percentage by mass, based on the total mass of the gypsum self-leveling material being 100%:

[0009]

[0010] The decomposition components include copper hydroxide and alkali, and the molar ratio of the copper hydroxide to the hydroxide in the alkali is 1.6:1 to 2:1.

[0011] The above-mentioned gypsum self-leveling provided by the present invention, firstly, based on its own high porosity characteristics, there are still a large number of pores on the surface after hardening during application, and the presence of activated carbon also creates pores on the surface of the gypsum self-leveling during application, ensuring that the activated carbon located inside still maintains good adsorption of formaldehyde. Secondly, the formaldehyde adsorbed by the activated carbon reacts with the copper hydroxide in the decomposition component under alkaline conditions and decomposes (as shown in the following formula 1), which also avoids the drawback of desorption after adsorption saturation when using activated carbon as an adsorbent in the prior art; at the same time, the gypsum in the gypsum self-leveling releases heat during curing, which provides a heat source for the decomposition reaction and promotes the reaction of decomposing formaldehyde. In addition, the addition of activated carbon can also improve the late coagulation and hardening speed of the gypsum self-leveling, and the surface of the material after coagulation has many pores, which can also effectively accelerate the loss of internal moisture and shorten the air-drying period when the gypsum self-leveling is applied.

[0012]

[0013] Generally, the alkali can be selected from conventional alkaline substances such as sodium hydroxide and potassium hydroxide to provide an alkaline environment for the above decomposition reaction.

[0014] Furthermore, the gypsum powder is a desulfurized gypsum powder obtained by calcining the wet desulfurization product of a power plant, and its main component is calcium sulfate hemihydrate, and it does not contain radioactive elements and toxic components.

[0015] Furthermore, the retarder is a composite amino acid, such as modified polyurethane, which can achieve a retarding effect without affecting the flow properties of the gypsum self-leveling material during application, thereby extending the flow time of the gypsum self-leveling material.

[0016] Furthermore, the water reducing agent is a polycarboxylic acid water reducing agent, which can effectively improve the flowability and construction time of the gypsum self-leveling material during application.

[0017] Furthermore, the leveling agent is a cellulose water-retaining agent or a cellulose ether water-retaining agent, so as to exert the water-retaining function of the mortar and increase the flowability.

[0018] Of course, gypsum powder, retarder, water reducing agent and leveling agent are conventional basic components in gypsum self-leveling and are not limited to those described above, and any conventional selection in the art may be used.

[0019] The present invention also provides a method for preparing the above-mentioned gypsum self-leveling, which comprises uniformly mixing gypsum powder, activated carbon, retarder, water reducer, homogenizer and decomposition components according to a predetermined mass ratio to obtain the gypsum self-leveling.

[0020] The present invention also provides an application of the above-mentioned gypsum self-leveling, wherein the remaining components of the gypsum self-leveling except the activated carbon are uniformly mixed with water to obtain a premixed slurry with a fluidity of 140mm to 150mm, and then the activated carbon and the premixed slurry are uniformly mixed to serve as a floor leveling layer material.

[0021] Adding activated carbon at the end can effectively prevent it from reacting with other small amounts of components and becoming ineffective.

[0022] It is further preferably used as floor heating backfill leveling material. The heat provided by the floor heating pipe can further provide a heat source for the above-mentioned formaldehyde decomposition reaction, so that the gypsum in the gypsum self-leveling can continue to decompose the adsorbed formaldehyde after the gypsum is cured, thereby achieving the purpose of long-term formaldehyde removal.

[0023] The above-mentioned self-leveling gypsum provided by the present invention, based on its excellent properties of adsorbing and decomposing formaldehyde, can be used in construction such as indoor floor renovation, and can further treat formaldehyde continuously released from indoor furniture, etc., and play a long-term effect on improving residential safety. DETAILED DESCRIPTION

[0024] For a better understanding of the present invention, the following examples are further illustrative of the present invention and are only used to explain the content of the present invention, but not to limit the present invention. All similar embodiments listed based on the present invention should fall within the protection scope thereof.

[0025] Example 1

[0026] This embodiment provides a gypsum self-leveling material that absorbs and decomposes formaldehyde and a construction application process thereof.

[0027] First, 70 kg of gypsum powder, 20 kg of activated carbon (400 mesh), 0.5 kg of modified polyamino acid retarder, 0.3 kg of polycarboxylic acid water reducer, 0.2 kg of hydroxypropyl methylcellulose water retaining agent (400 Pa·s), 8.3 kg of copper hydroxide and 1.7 kg of sodium hydroxide were weighed and set aside.

[0028] Then, the remaining components except the activated carbon were mixed to obtain a mixed powder, and water with a mass of half of the mixed powder was added thereto, and the mixture was fully stirred and mixed at 500 rpm for 3 minutes to obtain a premix slurry.

[0029] Again, the activated carbon is evenly sprinkled into the premixed slurry and mixed thoroughly to obtain a gypsum self-leveling slurry.

[0030] The fourth step is to pump the gypsum self-leveling slurry to the indoor construction area for self-leveling leveling process.

[0031] Step 5: After leveling, let it stand until the plaster hardens.

[0032] Finally, open the windows for ventilation to reduce the moisture content of the self-leveling gypsum before proceeding with the subsequent brick laying process.

[0033] Example 2

[0034] This embodiment provides a gypsum self-leveling material that absorbs and decomposes formaldehyde and a construction application process thereof.

[0035] First, 60 kg of gypsum powder, 20 kg of activated carbon (400 mesh), 0.7 kg of modified polyamino acid retarder, 0.25 kg of polycarboxylic acid water reducer, 0.2 kg of hydroxypropyl methylcellulose water retaining agent (400 Pa·s), 15.08 kg of copper hydroxide and 3.77 kg of sodium hydroxide were weighed and set aside.

[0036] Then, the remaining components except the activated carbon were mixed to obtain a mixed powder, and water with a mass of half of the mixed powder was added thereto, and the mixture was fully stirred and mixed at 500 rpm for 3 min to 4 min to obtain a premix slurry.

[0037] Again, the activated carbon is evenly sprinkled into the premixed slurry and mixed thoroughly to obtain a gypsum self-leveling slurry.

[0038] The fourth step is to pump the gypsum self-leveling slurry to the indoor construction area for self-leveling leveling process.

[0039] Step 5: After leveling, let it stand until the plaster hardens.

[0040] Finally, open the windows for ventilation to reduce the moisture content of the self-leveling gypsum before proceeding with the subsequent brick laying process.

[0041] Example 3

[0042] This embodiment provides a gypsum self-leveling material that absorbs and decomposes formaldehyde and a construction application process thereof.

[0043] First, 60 kg of gypsum powder, 20 kg of activated carbon (200 mesh), 0.7 kg of modified polyamino acid retarder, 0.25 kg of polycarboxylic acid water reducer, 0.2 kg of hydroxypropyl methylcellulose water retaining agent (400 Pa·s), 7.08 kg of copper hydroxide and 1.77 kg of sodium hydroxide were weighed and set aside.

[0044] Then, the remaining components except the activated carbon were mixed to obtain a mixed powder, and water with a mass of half of the mixed powder was added thereto, and the mixture was fully stirred and mixed at 500 rpm for 3 minutes to obtain a premix slurry.

[0045] Again, the activated carbon is evenly sprinkled into the premixed slurry and mixed thoroughly to obtain a gypsum self-leveling slurry.

[0046] The fourth step is to pump the gypsum self-leveling slurry to the indoor construction area for self-leveling leveling process.

[0047] Step 5: After leveling, let it stand until the plaster hardens.

[0048] Finally, open the windows for ventilation to reduce the moisture content of the self-leveling gypsum before proceeding with the subsequent brick laying process.

[0049] In order to verify the formaldehyde treatment effect of the above-mentioned gypsum self-leveling and the influence of activated carbon on the setting time of gypsum self-leveling, several comparative experiments were carried out.

[0050] Comparative Example 1

[0051] The similarities between this comparative example and Example 1 are not described here, and only the differences from Example 1 are described. The difference between the comparative gypsum self-leveling provided in this comparative example and the gypsum self-leveling in Example 1 is that the use of activated carbon is eliminated, and the amount of gypsum powder is adjusted to 90 kg; the rest is as shown in Example 1, and the construction application of the comparative gypsum self-leveling is completed.

[0052] Comparative Example 2

[0053] The similarities between this comparative example and Example 1 are not described here, and only the differences from Example 1 are described. The difference between the comparative gypsum self-leveling provided in this comparative example and the gypsum self-leveling in Example 1 is that the use of copper hydroxide and sodium hydroxide is eliminated, and the amount of gypsum powder is adjusted to 80 kg; the rest is as shown in Example 1, and the construction application of the comparative gypsum self-leveling is completed.

[0054] Comparative Example 3

[0055] The similarities between this comparative example and Example 1 are not described here, and only the differences from Example 1 are described. The difference between the comparative gypsum self-leveling provided in this comparative example and the gypsum self-leveling in Example 1 is that the use of sodium hydroxide is eliminated; the rest is as shown in Example 1, and the construction application of the comparative gypsum self-leveling is completed.

[0056] The setting time of the gypsum self-leveling in the above-mentioned embodiments and comparative examples, and the formaldehyde removal effect of the provided gypsum self-leveling were monitored at different time periods.

[0057] The specific monitoring method for formaldehyde removal effect is as follows: 3The experiment was carried out in a sealed glass test chamber, using formaldehyde solution (concentration 37% to 40%), and detecting low-density formaldehyde gas (1.0 mg / m 3 The formaldehyde removal rate is recorded according to the formaldehyde limit of GB / T 18883-2002 "Indoor Air Quality Standard" of 0.1mg / m 3 When testing the purification efficiency of gaseous pollutants in air purifiers in GB / T 18801-2008 "Air Purifiers", the initial concentration of the gas is set to 10 times the limit value specified in GB / T18883-2002, that is, the formaldehyde gas is set to 1.0 mg / m 3 .

[0058] The performance test results are shown in Table 1 below.

[0059] Table 1 Performance test of each embodiment and comparative example after construction

[0060]

[0061] It can be seen from Table 1 that the gypsum self-leveling materials provided by the embodiments of the present invention show a good formaldehyde removal effect in 1 hour, and the formaldehyde concentration can be increased from 1.0 mg / cm 3 The removal rate of formaldehyde in the 3h period can be reduced to at least half of the level (Example 3), and at least 73% can be achieved after 3h. Moreover, according to the test, the higher the content of the decomposition components, the higher the formaldehyde removal rate in 3h when the content of activated carbon remains unchanged.

[0062] In contrast, in Comparative Example 1, no activated carbon was added, and the porous structure of the gypsum base itself was used to attract and decompose formaldehyde, and the removal rate was only 35.7%. In addition, by comparing the setting time, it can be seen that the presence of activated carbon helps to shorten the setting time.

[0063] If only activated carbon is added in Comparative Example 2 without adding decomposition components, the 3h removal rate is only 53.6%, which mainly depends on the adsorption effect of activated carbon, which is no different from the removal effect of directly using activated carbon and other adsorbents in the prior art. There must be a desorption effect after reaching adsorption saturation.

[0064] If no alkali is added in Comparative Example 3, the copper hydroxide in the decomposition component will be consumed first as a simple alkaline substance, which will eventually lead to a decrease in its decomposition rate.

[0065] It can be seen that the self-leveling gypsum provided by the present invention, the activated carbon for adsorbing formaldehyde, and the copper hydroxide and alkali for decomposing formaldehyde are all indispensable.

[0066] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A gypsum self-leveling material that absorbs and decomposes formaldehyde, characterized in that: Taking the total mass of the gypsum self-leveling as 100%, the following components are included in mass percentage: The decomposition components include copper hydroxide and alkali, and the molar ratio of copper hydroxide to hydroxide in the alkali is 1.6:1 to 2:

1.

2. The gypsum self-leveling according to claim 1, characterized in that: The base is selected from sodium hydroxide and potassium hydroxide.

3. The gypsum self-leveling according to claim 1 or 2, characterized in that: The gypsum powder is desulfurized gypsum powder obtained by calcining the wet desulfurization product of a power plant.

4. The gypsum self-leveling according to claim 1 or 2, characterized in that: The retarder is a composite amino acid retarder.

5. The gypsum self-leveling according to claim 1 or 2, characterized in that: The water reducing agent is a polycarboxylic acid water reducing agent.

6. The gypsum self-leveling according to claim 1 or 2, characterized in that: The leveling agent is a cellulose water retaining agent or a cellulose ether water retaining agent.

7. The use of gypsum self-leveling according to any one of claims 1 to 6, characterized in that: Includes steps: S1. Mix all components of the gypsum self-leveling except activated carbon with water to obtain a premixed slurry with a fluidity of 140 mm to 150 mm; S2. Evenly mix the activated carbon and the premixed slurry to form a floor leveling layer material.

8. The use according to claim 7, characterized in that: The self-leveling gypsum is used as a leveling layer material for floor heating backfill.

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