An adsorption paper and its preparation method

Abstract

The present invention relates to an adsorption paper and a preparation method thereof, in particular to an adsorption paper suitable for formaldehyde adsorption and a preparation method thereof. In the present invention, zeolite is coated on the outer side of the paper base body, and a polyamide layer with a porous structure is prepared by interfacial polymerization. The polyamide layer fixes the zeolite on the paper base body and avoids physical or chemical damage during subsequent applications, enhancing the strength of the adsorption paper.

Description

Technical Field

[0001] The present invention relates to an adsorption paper and a preparation method thereof, and particularly to an adsorption paper suitable for formaldehyde adsorption and a preparation method thereof. Background Art

[0002] With the popularization of modern home decoration, the problem of formaldehyde pollution has attracted increasing attention. Formaldehyde is a gas harmful to human health, and long-term exposure may cause health problems. Therefore, effectively removing indoor formaldehyde has become an urgent need. As a new type of formaldehyde adsorption material, adsorption paper has received extensive attention for its high efficiency and convenience.

[0003] Traditional adsorption papers usually achieve their adsorption function by blending inorganic nanoparticles such as zeolite with pulp for papermaking or coating inorganic nanoparticles on paper-based materials. Compared with the former, the latter's zeolite does not affect the paper properties and does not require additional optimization of the papermaking process. Moreover, the adsorption efficiency of inorganic nanoparticles is higher. However, due to its particle structure and surface properties, zeolite is prone to fall off from the paper-based material, thus affecting the service life and performance of the adsorption paper. The prior art often uses adhesives to adhere zeolite to the surface of the paper base to avoid its shedding, but the use of adhesives reduces the air permeability of the paper-based material, and the adhesives are prone to aging, resulting in the shedding of zeolite. Therefore, how to enhance the adhesion of molecular sieves on paper-based materials without affecting air permeability has become an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method of an adsorption paper. By coating an amino-modified molecular sieve on a paper-based material and forming a polyamide network structure through interfacial polymerization, the molecular sieve is fixed on the paper-based material, solving the problem that the molecular sieve is prone to fall off in the prior art, and at the same time maintaining good air permeability.

[0005] The present invention provides a preparation method of an adsorption paper, which comprises the following steps:

[0006] (1) Prepare a paper base body with carboxyl groups on the surface: Dissolve carboxymethyl cellulose in water, and gradually add it to the pulp, and stir well to ensure uniform mixing of carboxymethyl cellulose and pulp fibers, and use the papermaking process to prepare the paper base body;

[0007] (2) Prepare amino-functionalized zeolite: After drying the zeolite at high temperature, immerse it in an ethylenediamine solution, take it out after the immersion ends, and dry and calcine it to obtain amino-functionalized zeolite;

[0008] (3) Prepare a paper base body with zeolite coated on the surface: Mix the amino-functionalized zeolite obtained in step (2) with water to form a coating solution, uniformly coat it on the paper base body prepared in step (1), and dry it.

[0009] (4) Preparation of an adsorption paper with a polyamide layer: The paper substrate coated with zeolite prepared in step (3) is coated with an organic phase solution containing dichloroformate, and after standing for 1 - 2 min, it is further coated with an aqueous phase solution containing polyamine groups to initiate interfacial polymerization to form a polyamide layer. After drying, the adsorption paper is obtained.

[0010] Preferably, the molecular sieve is one or more of ZSM-5, MCM-41, DD3R, or Y-type molecular sieves.

[0011] Preferably, the addition amount of carboxymethyl cellulose is 0.05 - 0.5 wt% of the absolute dry weight of the pulp.

[0012] Preferably, in step (2), the concentration of the ethylenediamine solution is 5 - 25 mg / L.

[0013] Preferably, in step (3), the concentration of zeolite in the coating solution is 1 - 5 wt%.

[0014] Preferably, in step (3), the coating amount of zeolite on the paper substrate is 0.5 - 2.5 g / m2.

[0015] Preferably, the acyl chloride is a long-chain aliphatic polyacyl chloride or a polyacyl chloride containing a flexible ether bond or ester bond, such as one of dodecanedioyl chloride (C12), hexadecanedioyl chloride (C16), and polyethylene glycol diacyl chloride, and the concentration is 0.005 - 0.05 wt%.

[0016] Preferably, the polyamine is one or more of ethylenediamine, hexamethylenediamine, or diethylenetriamine, and the concentration is 0.05 - 0.5 wt%.

[0017] The present invention also provides an adsorption paper prepared according to the above method. The adsorption paper includes a paper substrate, a zeolite layer, and a polyamide layer connected in sequence. The paper substrate contains carboxymethyl cellulose, and the zeolite in the zeolite layer is amino-modified zeolite.

[0018] The present invention also provides an application of the above adsorption paper in adsorbing formaldehyde.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] First, the present invention coats zeolite on the outer side of the paper substrate and prepares a polyamide layer with a porous structure through interfacial polymerization. On the one hand, the polyamide layer fixes the zeolite on the paper substrate and avoids physical or chemical damage during subsequent applications, enhancing the strength of the adsorption paper. On the other hand, the method of first coating polyacyl chloride and then coating polyamine can make the polyamide have abundant amino groups, further improving the formaldehyde removal ability of the adsorption paper.

[0021] Secondly, the zeolite modified by ethylenediamine is adopted in the present invention. On the one hand, the adsorption performance of the zeolite can be improved. On the other hand, covalent bonds can be formed with the paper substrate containing carboxyl groups on the surface and polyacyl chloride, further improving the stability of the zeolite.

[0022] In addition, specific polyamines and polyacyl chlorides are adopted in the present invention, which can provide more space during the polymerization process, contribute to the formation of a loose polymer network structure, and thus improve the air permeability of the polyamide layer.

[0023] Finally, for the adsorption paper prepared by the method provided by the present invention, the molecular sieve and the paper-based material are tightly combined through the polyamide network structure, are not easy to fall off, and at the same time maintain good air permeability, and have excellent adsorption effect and service life. Detailed implementation manners

[0024] Example 1: The adsorption paper in this example was prepared by the following method:

[0025] Prepare sulfite softwood pulp, and then gradually add carboxymethyl cellulose dissolved in water to the sulfite softwood pulp, and stir well to ensure that the carboxymethyl cellulose is evenly mixed with the pulp fibers. The addition amount of carboxymethyl cellulose in the pulp is 0.1 wt% of the absolute dry weight of the pulp, and then the paper substrate is prepared by papermaking, pressing, and drying;

[0026] Take ZSM-5 with an average particle size of 87 nm, perform high-temperature drying, then immerse it in a 10 mg / L ethylenediamine solution for 2 h, take it out after the immersion is completed, and dry and calcine it to obtain amino-functionalized zeolite;

[0027] Mix the above-mentioned amino-functionalized zeolite with water to form a coating solution with a concentration of 2 wt%, evenly coat it on the paper substrate, the coating amount is 2 g / m2, and dry it;

[0028] First coat the above-mentioned paper substrate with a n-hexane solution containing 0.01 wt% of hexadecanedioyl chloride, let it stand for 1 min, and then continue to coat it with an aqueous solution containing 0.2 wt% of diethylenetriamine to form a polyamide layer, and obtain the adsorption paper after drying.

[0029] Example 2: The adsorption paper in this example was prepared by the following method:

[0030] (1) Prepare sulfite softwood pulp, and then gradually add carboxymethyl cellulose dissolved in water to the sulfite softwood pulp, and stir well to ensure that the carboxymethyl cellulose is evenly mixed with the pulp fibers. The addition amount of carboxymethyl cellulose in the pulp is 0.1 wt% of the absolute dry weight of the pulp, and then the paper substrate is prepared by papermaking, pressing, and drying;

[0031] (2) DD3R with an average particle size of 118 nm was dried at high temperature, and then immersed in a 10 mg / L ethylenediamine solution for 2 h. After the immersion, it was taken out, dried, and calcined to obtain amino-functionalized zeolite;

[0032] (3) Mixing the amino-functionalized zeolite with water to form a coating liquid with a concentration of 2 wt%, uniformly coating the liquid on the paper substrate at a coating amount of 2 g / m2, and drying the liquid;

[0033] (4) The paper substrate is first coated with a n-hexane solution containing 0.01 wt% of hexadecane dioyl chloride, and then coated with an aqueous solution containing 0.2 wt% of diethylenetriamine to form a polyamide layer after standing for 1 minute. After drying, an adsorbent paper is obtained.

[0034] Example 3: The adsorption paper of this example is prepared by the following method:

[0035] (1) preparing sulfite softwood pulp, and then preparing a paper base through papermaking, pressing and drying;

[0036] (2) taking ZSM-5 with an average particle size of 87 nm, drying it at high temperature, and then immersing it in a 10 mg / L ethylenediamine solution for 2 h. After the immersion, taking it out, drying it, and calcining it to obtain an amino-functionalized zeolite;

[0037] (3) Mixing the amino-functionalized zeolite with water to form a coating liquid with a concentration of 2 wt%, uniformly coating the liquid on the paper substrate at a coating amount of 2 g / m2, and drying the liquid;

[0038] (4) The paper substrate is first coated with a n-hexane solution containing 0.01 wt% of hexadecane dioyl chloride, and then coated with an aqueous solution containing 0.2 wt% of diethylenetriamine to form a polyamide layer after standing for 1 minute. After drying, an adsorbent paper is obtained.

[0039] Example 4: The adsorption paper of this example is prepared by the following method:

[0040] Sulfite softwood pulp is prepared, and then carboxymethyl cellulose dissolved in water is gradually added to the sulfite softwood pulp, and the carboxymethyl cellulose is fully stirred to ensure that the carboxymethyl cellulose is evenly mixed with the pulp fibers, and the amount of carboxymethyl cellulose added to the pulp is 0.1wt% of the absolute dry weight of the pulp, and then papermaking, pressing, and drying are performed to prepare a paper base body;

[0041] Take ZSM-5 with an average particle size of 87 nm and dry it at high temperature for later use;

[0042] The zeolite is mixed with water to form a coating liquid with a concentration of 2 wt%, and the coating liquid is evenly coated on the paper substrate with a coating amount of 2 g / m2, and then dried;

[0043] The above-mentioned paper substrate was first coated with a n-hexane solution containing 0.01 wt% of hexanedicarbonyl dichloride. After standing for 1 min, it was further coated with an aqueous solution containing 0.2 wt% of diethylenetriamine to form a polyamide layer. After drying, the adsorption paper was obtained.

[0044] Example 5: The adsorption paper of this example was prepared by the following method:

[0045] Prepare sulfite softwood pulp, and then gradually add carboxymethyl cellulose dissolved in water to the sulfite softwood pulp, and stir well to ensure uniform mixing of carboxymethyl cellulose and pulp fibers. The addition amount of carboxymethyl cellulose in the pulp is 0.1 wt% of the pulp dry weight. Then, the paper substrate was prepared by papermaking, pressing, and drying.

[0046] Take ZSM-5 with an average particle size of 87 nm, perform high-temperature drying, then immerse it in a 10 mg / L ethylenediamine solution for 2 h. After the immersion, take it out, dry and calcine to obtain amino-functionalized zeolite.

[0047] Mix the above-mentioned amino-functionalized zeolite with water to form a coating solution with a concentration of 2 wt%, uniformly coat it on the paper substrate, the coating amount is 2 g / m2, and dry it.

[0048] The above-mentioned paper substrate was first coated with a n-hexane solution containing 0.01 wt% of hexanedicarbonyl dichloride. After standing for 1 min, it was dried to obtain the adsorption paper.

[0049] Example 6: The adsorption paper of this example was prepared by the following method:

[0050] Prepare sulfite softwood pulp, and then gradually add carboxymethyl cellulose dissolved in water to the sulfite softwood pulp, and stir well to ensure uniform mixing of carboxymethyl cellulose and pulp fibers. The addition amount of carboxymethyl cellulose in the pulp is 0.1 wt% of the pulp dry weight. Then, the paper substrate was prepared by papermaking, pressing, and drying.

[0051] Take ZSM-5 with an average particle size of 87 nm, perform high-temperature drying, then immerse it in a 10 mg / L ethylenediamine solution for 2 h. After the immersion, take it out, dry and calcine to obtain amino-functionalized zeolite.

[0052] Mix the above-mentioned amino-functionalized zeolite with water to form a coating solution with a concentration of 2 wt%, uniformly coat it on the paper substrate, the coating amount is 2 g / m2, and dry it.

[0053] The above-mentioned paper substrate was first coated with a n-hexane solution containing 0.01 wt% of trimellitic acid trichloride. After standing for 1 min, it was further coated with an aqueous solution containing 0.2 wt% of diethylenetriamine to form a polyamide layer. After drying, the adsorption paper was obtained.

[0054] Performance characterization

[0055] The adsorption paper of the above-mentioned embodiment was subjected to a 24-hour adsorption test on formaldehyde gas with a concentration of 60,000 mg / m3 under the same conditions, and the adsorption paper was fixed in an air flow environment with a velocity of 5 m / s for 5 hours, and then its adsorption performance for formaldehyde and other performance tests were measured. For specific results, see Table 1;

[0056]

[0057] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for preparing an adsorbent paper, characterized in that The steps include: (1) Preparing a paper base body containing carboxyl groups on the surface: dissolving carboxymethyl cellulose in water, gradually adding the carboxymethyl cellulose to paper pulp, and stirring the water sufficiently to ensure that the carboxymethyl cellulose and the paper pulp fibers are evenly mixed, and preparing the paper base body by using a papermaking process; (2) preparing amino-functionalized zeolite: drying the zeolite at high temperature, and then immersing it in an ethylenediamine solution. After the immersion is completed, the zeolite is taken out, dried, and calcined to obtain the amino-functionalized zeolite; (3) preparing a paper substrate coated with zeolite: mixing the amino-functionalized zeolite obtained in step (2) with water to form a coating liquid, uniformly coating the paper substrate prepared in step (1), and drying; (4) Preparation of adsorbent paper with a polyamide layer: The paper substrate coated with zeolite prepared in step (3) is coated with an organic phase solution containing diformyl chloride, and after standing for 1-2 minutes, an aqueous phase solution containing a polyamine group is continuously coated to initiate interfacial polymerization to form a polyamide layer, and the adsorbent paper is obtained after drying.

2. The preparation method according to claim 1, characterized in that The zeolite is one or more of ZSM-5, MCM-41, DD3R or Y-type molecular sieve.

3. The preparation method according to claim 1, characterized in that The added amount of carboxymethyl cellulose is 0.05-0.5wt% of the absolute dry weight of the pulp.

4. The preparation method according to claim 1, characterized in that The concentration of the ethylenediamine solution in step (2) is 5-25 mg / L.

5. The preparation method according to claim 1, characterized in that The concentration of zeolite in the coating solution in step (3) is 1-5 wt %.

6. The preparation method according to claim 1, characterized in that In step (3), the coating amount of zeolite on the paper substrate is 0.5-2.5 g / m 2 .

7. The preparation method according to claim 1, characterized in that The acyl chloride is a long-chain aliphatic polyacyl chloride or a polyacyl chloride containing a flexible ether bond or an ester bond, and the concentration is 0.005-0.05 wt %.

8. The preparation method according to claim 1, characterized in that The polyamine is one or more of ethylenediamine, hexamethylenediamine or diethylenetriamine, and the concentration is 0.05-0.5wt%.

9. An adsorbent paper prepared according to the method of claim 1, characterized in that The adsorption paper comprises a paper base body, a zeolite layer and a polyamide layer which are connected in sequence. The paper base body contains carboxymethyl cellulose, and the zeolite in the zeolite layer is amino-modified zeolite.

10. Use of the adsorption paper according to claim 9 in adsorbing formaldehyde.

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