Super absorbent resin with self-heating function as well as preparation method and application of super absorbent resin

Abstract

The invention relates to super absorbent resin with a self-heating function as well as a preparation method and application of the super absorbent resin. The method comprises the following steps: preparing an acrylic acid solution with the concentration of 20-40wt%, and then adding a sodium hydroxide solution to adjust the neutralization degree of acrylic acid to 65-75% to obtain a mixed solution; adding an initiator and a cross-linking agent into the mixed solution, uniformly mixing, and carrying out polymerization reaction under ultraviolet light to obtain colloid; granulating the colloid to obtain colloidal particles, uniformly scattering a self-heating functional material on the surfaces of the colloidal particles, and repeatedly granulating to obtain modified colloidal particles; sequentially drying, crushing and screening the modified colloidal particles, and then carrying out surface treatment to obtain the super absorbent resin with the self-heating function. The super absorbent resin prepared by the preparation method disclosed by the invention can perform spontaneous heating during liquid absorption, and heat generated by the super absorbent resin can be stored and slowly released, so that a very good heat preservation effect is achieved, and the absorption speed of the super absorbent resin is effectively increased.

Description

Technical Field

[0001] The invention relates to the technical field of polymer functional polymer chemical additives, and in particular to a highly water-absorbent resin with a self-heating function, and a preparation method and application thereof. Background Art

[0002] Super absorbent resin is a new functional polymer material developed in recent years that contains strong hydrophilic groups and moderate cross-linking. It is widely used in baby diapers, sanitary napkins, adult diapers and other sanitary products due to its excellent water absorption and water retention capabilities. At present, there are many functional sanitary napkins on the market, such as Chinese medicine sanitary napkins. In actual use, due to temperature restrictions, the efficacy of Chinese medicine is not fully exerted.

[0003] In summary, it is very necessary to provide a highly absorbent resin with self-heating function and a preparation method and application thereof. Summary of the invention

[0004] In order to solve one or more technical problems existing in the prior art, the present invention provides a highly water-absorbent resin with a self-heating function, and a preparation method and application thereof.

[0005] In a first aspect, the present invention provides a method for preparing a super absorbent resin having a self-heating function, the preparation method comprising the following steps:

[0006] (1) preparing an acrylic acid solution with a concentration of 20 to 40 wt %, and then adding a sodium hydroxide solution to adjust the neutralization degree of the acrylic acid to 65 to 75%, to obtain a mixed solution;

[0007] (2) adding an initiator and a cross-linking agent to the mixed solution and mixing them evenly, and then performing a polymerization reaction under ultraviolet light to obtain a colloid;

[0008] (3) granulating the colloid to obtain colloid particles, and then evenly spreading the self-heating functional material on the surface of the colloid particles and repeatedly granulating to obtain modified colloid particles;

[0009] (4) The modified rubber particles are dried, crushed, and sieved in sequence, and then surface treated to obtain a highly absorbent resin with a self-heating function.

[0010] Preferably, the concentration of the acrylic acid solution is 24-39 wt %; and / or in the process of adjusting the neutralization degree of acrylic acid to 65-75%, the temperature of the system is controlled not to exceed 50°C.

[0011] Preferably, the initiator is benzoin isopropyl ether; and / or the amount of the initiator used is 0.2-1% of the mass of the acrylic acid.

[0012] Preferably, the crosslinking agent is one or more of N,N-methylenebisacrylamide, glycidyl methacrylate, dipentaerythritol pentaacrylate, triallyl isocyanurate, tetraallyloxyethane; and / or the amount of the crosslinking agent is 0.05-0.2% of the mass of the acrylic acid.

[0013] Preferably, the polymerization reaction is carried out under an ultraviolet lamp with a wavelength of 365 nm, and the polymerization reaction time is 30 to 50 minutes.

[0014] Preferably, the self-heating functional material is a mixture of far-infrared ceramic powder and heating iron powder, the mass ratio of the far-infrared ceramic powder to the heating iron powder is (0.02-0.08):(1-1.2); and / or the amount of the self-heating functional material is 0.1-1% of the mass of the acrylic acid.

[0015] Preferably, the granulation is repeated at least 5 times; a meat grinder is used for granulation; the drying temperature is 150-180° C.; and / or the modified granules with a particle size of 30-80 mesh are obtained by sieving.

[0016] Preferably, the surface treatment temperature is 160-180°C, and the surface treatment time is 20-30 min; the surface treatment agent used in the surface treatment consists of 30-35 parts by weight of butanediol, 2-3 parts by weight of polybutylene glycol diglycidyl ether and 62-68 parts by weight of deionized water; modified particles with a particle size of 30-80 mesh are obtained by screening, and the amount of the surface treatment agent is 3-5% of the mass of the modified particles.

[0017] In a second aspect, the present invention provides a highly water-absorbent resin having a self-heating function, which is prepared by the preparation method described in the first aspect of the present invention.

[0018] The third aspect of the present invention provides the use of a highly absorbent resin with a self-heating function prepared by the preparation method described in the first aspect of the present invention in a sanitary napkin containing a traditional Chinese medicine component.

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

[0020] (1) In view of the problem of limited functions of Chinese medicine sanitary napkins during use, the present invention, for the first time, adds a self-heating functional material during the preparation of a super absorbent resin, so that the prepared super absorbent resin can self-heat when absorbing liquid, store the heat generated by itself and slowly release it, thereby achieving a good heat preservation effect; and, by reasonably designing the composition ratio of the self-heating functional material, the present invention can increase the temperature of 37.5°C blood by 3.5-4.5°C after being absorbed by the super absorbent resin and maintain it for about 30 minutes. The entire heat preservation process can maximize the efficacy of Chinese medicine, so that the functionality of sanitary napkins containing Chinese medicine ingredients (such as Chinese medicine sanitary napkins) is fully reflected, effectively solving the problem that the efficacy of Chinese medicine in existing sanitary napkins containing Chinese medicine ingredients (such as Chinese medicine sanitary napkins) cannot be fully exerted due to temperature limitations during actual use.

[0021] (2) The present invention adopts a unique adding method, that is, the self-heating functional material is uniformly sprinkled on the surface of the colloid particles and then repeated granulation (repeated granulation extrusion) is performed, so that the colloid particles with the self-heating functional material sprinkled on the surface form modified colloid particles with a "fish-eye" structure. The present invention repeatedly squeezes the self-heating functional material into the interior of the colloid particles through the extrusion and crushing action of a meat grinder, that is, the self-heating functional material is wrapped in the interior of the colloid particles (resin particles) to form a "fish-eye" structure; the present invention finds that the "fish-eye" structure formed by the self-heating functional material embedded in the colloid particles effectively improves the heating and heat preservation performance of the self-heating functional material, and can also improve the absorption rate of the super absorbent resin. The present invention squeezes the self-heating functional material uniformly into the resin through repeated granulation extrusion. Inside the particles, this distribution mode can effectively improve the heating efficiency of the super absorbent resin when a small amount of self-heating functional material is added, and at the same time, it can reduce the situation of local overheating, improve the overall self-heating performance of the super absorbent resin, and the formed "fish eye" structure helps to form a relatively closed area inside the resin particles, which is conducive to the accumulation of heat, reduces heat loss, and improves the thermal insulation performance of the super absorbent resin, so that the heat can be retained inside the resin for a longer time, so that it can maintain a higher temperature for a longer time; and the "fish eye" structure formed by repeated granulation and extrusion of the present invention makes a certain gap inside the super absorbent resin, which provides a large number of channels for water molecules to enter the inside of the super absorbent resin, effectively improving the absorption rate of the super absorbent resin. The present invention neither chooses to add self-heating functional materials during the polymerization process of the super absorbent resin, which will not affect the polymerization reaction and the performance indicators of the super absorbent resin, nor chooses to add self-heating functional materials during the surface treatment process, so there will be no problems such as poor adsorption and uneven mixing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 11 is an electron microscope image of the super absorbent resin with self-heating function obtained in Example 3 of the present invention; in the figure, Figure (b) is an enlarged view of the A part in Figure (a);

[0023] Figure 2 1 is an electron microscope image of the highly water-absorbent resin obtained in Comparative Example 3 of the present invention; in the image, image (b) is an enlarged image of portion A in image (a). DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0025] In a first aspect, the present invention provides a method for preparing a super absorbent resin having a self-heating function, the preparation method comprising the following steps:

[0026] (1) preparing an acrylic acid solution with a concentration of 20 to 40 wt %, and then adding a sodium hydroxide solution to adjust the neutralization degree (molar neutralization degree) of the acrylic acid to 65 to 75%, to obtain a mixed solution; in the present invention, the acrylic acid solution is an acrylic acid aqueous solution, and the sodium hydroxide solution is a sodium hydroxide aqueous solution, and the concentration of the sodium hydroxide solution is, for example, 40 to 60 wt %; specifically, step (1) is, for example: taking an appropriate amount of acrylic acid in a 1000 mL flask, adding a certain amount of deionized water so that the concentration of the acrylic acid is controlled at 20 to 40 wt %; adding a sodium hydroxide solution to adjust the molar neutralization degree of the acrylic acid to 65 to 75%; the present invention does not specifically limit the amount of the sodium hydroxide solution used, and it is sufficient to adjust the neutralization degree of the acrylic acid to a range of 65 to 75%;

[0027] (2) adding an initiator and a cross-linking agent to the mixed solution and mixing them uniformly, and then performing a polymerization reaction under ultraviolet light to obtain a colloid; specifically, step (2) is, for example: adding an initiator and a cross-linking agent to the mixed solution and ultrasonically dispersing them until they are uniformly mixed, transferring the mixed solution to which the initiator and the cross-linking agent are added into a quartz tube, and then placing the quartz tube into an ultraviolet light reactor, and performing a polymerization reaction under an ultraviolet lamp with a wavelength of 365 nm to obtain a colloid;

[0028] (3) granulating the colloid to obtain colloid particles, and then evenly spreading the self-heating functional material on the surface of the colloid particles and repeatedly granulating to obtain modified colloid particles; specifically, step (3) is, for example: after the reaction in step (2) is completed and the colloid is obtained, the colloid is taken out and granulated by a meat grinder (one granulation) to obtain colloid particles, and then evenly spreading the self-heating functional material on the surface of the colloid particles and repeatedly granulating (multiple granulations) to obtain modified colloid particles; in the present invention, for example, the particle size of the modified colloid particles is 10 μm to 1 cm, preferably 100 μm to 1 cm, and more preferably 100 μm to 1 mm;

[0029] (4) The modified rubber particles are dried, crushed, and sieved in sequence, and then surface treated to obtain a highly absorbent resin with a self-heating function.

[0030] In view of the problem of limited functions of Chinese medicine sanitary napkins during use, the present invention, for the first time, adds a self-heating functional material in the process of preparing a super absorbent resin, so that the prepared super absorbent resin can self-heat when absorbing liquid, store the heat generated by itself and slowly release it, thereby achieving a good thermal insulation effect; and, by reasonably designing the composition ratio of the self-heating functional material, the present invention can increase the temperature of 37.5°C blood by 3.5-4.5°C after being absorbed by the super absorbent resin and maintain it for about 30 minutes. The entire thermal insulation process can maximize the efficacy of Chinese medicine, so that the functionality of sanitary napkins containing Chinese medicine ingredients (such as Chinese medicine sanitary napkins) is fully reflected, effectively solving the problem that the efficacy of Chinese medicine in existing sanitary napkins containing Chinese medicine ingredients (such as Chinese medicine sanitary napkins) cannot be fully exerted due to temperature limitations during actual use. The present invention adopts a unique adding method, that is, the self-heating functional material is uniformly sprinkled on the surface of the colloid particles and then repeated granulation (repeated granulation extrusion) is performed, so that the colloid particles sprinkled with the self-heating functional material on the surface form modified colloid particles with a "fish-eye" structure. The present invention repeatedly squeezes the self-heating functional material into the interior of the colloid particles through the extrusion and crushing action of a meat grinder, that is, the self-heating functional material is wrapped in the interior of the colloid particles (resin particles), forming a "fish-eye" structure, for example, Figure 1As shown; the present invention finds that the "fish-eye" structure formed by embedding the self-heating functional material into the colloid particles effectively improves the heating and heat preservation performance of the self-heating functional material, and can also improve the absorption rate of the super absorbent resin. The present invention uniformly squeezes the self-heating functional material into the resin particles through repeated granulation and extrusion. This distribution method can effectively improve the heating efficiency of the super absorbent resin when a small amount of self-heating functional material is added, and can reduce the situation of local overheating, improve the overall self-heating performance of the super absorbent resin, and the formed "fish-eye" structure helps to form a relatively closed area inside the resin particles, which is conducive to the accumulation of heat, reduces heat loss, improves the heat preservation performance of the super absorbent resin, and allows the heat to be retained in the resin for a longer time, so that it can maintain a higher temperature for a longer time; and the "fish-eye" structure formed by repeated granulation and extrusion in the present invention allows certain gaps to exist inside the super absorbent resin, which provides a large number of channels for water molecules to enter the super absorbent resin, effectively improving the absorption rate of the super absorbent resin. The present invention neither chooses to add self-heating functional materials during the polymerization process of the super absorbent resin, which will not affect the polymerization reaction and the performance indicators of the super absorbent resin, nor chooses to add self-heating functional materials during the surface treatment process, which will not cause problems such as poor adsorption and uneven mixing.

[0031] According to some preferred embodiments, the concentration of the acrylic acid solution is 24-39wt% (for example, 24wt%, 28wt%, 30wt%, 32wt%, 35wt% or 39wt%); in the present invention, the concentration of the acrylic acid solution is controlled at 20-40wt%, more preferably 24-39wt%. If the concentration of acrylic acid is too low, the reaction activity is low, the reaction time is long, and the colloid obtained after the polymerization is soft and difficult to granulate. If the concentration of acrylic acid is too high, the polymerization reaction rate is fast, which will reduce the water retention performance of the super absorbent resin.

[0032] According to some preferred embodiments, in the process of adjusting the neutralization degree of acrylic acid to 65-75%, the temperature of the system is controlled not to exceed 50°C; in the present invention, for example, sodium hydroxide solution is slowly added dropwise to the acrylic acid solution for neutralization, and the temperature of the entire system is kept not more than 50°C.

[0033] According to some preferred embodiments, the initiator (photosensitizer) is benzoin isopropyl ether; and / or the amount of the initiator is 0.2-1% (e.g., 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9% or 1%) of the mass of the acrylic acid.

[0034] According to some preferred embodiments, the cross-linking agent is one or more of N,N-methylenebisacrylamide, glycidyl methacrylate, dipentaerythritol pentaacrylate, triallyl isocyanurate, and tetraallyloxyethane; and / or the amount of the cross-linking agent is 0.05-0.2% (e.g., 0.05%, 0.08%, 0.1%, 0.12%, 0.15%, 0.18% or 0.2%) of the mass of the acrylic acid.

[0035] According to some preferred embodiments, the polymerization reaction is carried out under an ultraviolet lamp with a wavelength of 365nm, and the polymerization reaction time is 30 to 50min (for example, 30, 35, 40, 45 or 50min); in the present invention, when carrying out the polymerization reaction, for example, the distance between the ultraviolet lamp source and the polymerization reaction system is maintained at 36 to 37cm; in the present invention, preferably, the polymerization reaction time is 30 to 50min. If the polymerization time is too short, the initiator produces fewer free radicals, the reaction is insufficient, and the prepared resin has extremely poor performance. If the polymerization time is too long, the resin is excessively cross-linked internally, which is not conducive to the stretching of the water-absorbing structure and will result in a decrease in the liquid absorption rate.

[0036] According to some preferred embodiments, the self-heating functional material is a mixture of far-infrared ceramic powder and heating iron powder, and the mass ratio of the far-infrared ceramic powder to the heating iron powder is (0.02-0.08): (1-1.2) (for example, 0.02:1, 0.04:1, 0.06:1, 0.08:1, 0.02:1.2, 0.04:1.2, 0.06:1.2 or 0.08:1.2); the present invention does not specifically limit the sources of the far-infrared ceramic powder and the heating iron powder, and products that can be directly purchased can be used. In some specific embodiments of the present invention, for example, the product number LS-YH produced by Xiamen Lvshe Biotechnology Co., Ltd. can be used. The far-infrared ceramic powder of Y68, for example, can be the 100-180 mesh heating iron powder with the product number XY-ZGCTF produced by Lingshou County Xuyang Mining Co., Ltd.; the present invention reasonably designs the composition ratio of the self-heating functional material, that is, the mass ratio of the far-infrared ceramic powder to the heating iron powder is (0.02-0.08): (1-1.2), and the temperature of 37.5°C blood can be raised by 3.5-4.5°C after being absorbed by the super absorbent resin and maintained for about 30 minutes. The whole heat preservation process can maximize the efficacy of traditional Chinese medicine, so that the functionality of sanitary napkins containing traditional Chinese medicine ingredients (such as traditional Chinese medicine sanitary napkins) is fully reflected; the present invention finds that in the self-heating functional material , if the proportion of far-infrared ceramic powder is too small and the proportion of heating iron powder is too large, the temperature of the super absorbent resin after absorbing liquid may rise too quickly, exceeding the expected temperature rise range, which may affect the comfort and safety of the product during use, and affect the thermal insulation effect; if the proportion of far-infrared ceramic powder is too large and the proportion of heating iron powder is too small, the heating iron powder cannot provide enough heat, resulting in insufficient heating effect, and will also reduce the thermal insulation effect of the product and the efficacy and comfort during use; and / or the amount of the self-heating functional material is 0.1% to 1% (for example, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8% or 0.9% of the mass of the acrylic acid .8%, 0.9% or 1%); in the present invention, preferably, the amount of the self-heating functional material is 0.1-1% of the mass of the acrylic acid. If the amount of the self-heating functional material is too little, it will affect the temperature rise and heat preservation effect of the super absorbent resin after absorbing liquid. If the amount of the self-heating functional material is too much, the temperature rise range of the super absorbent resin after absorbing liquid will exceed the expected temperature rise range, affecting the comfort and safety of the application product. In addition, due to the excessive amount of the self-heating functional material, part of the self-heating material may be easily concentrated on the surface of the colloid particles or in a local area, and a uniform "fish-eye" structure cannot be formed, thereby affecting the temperature rise uniformity and the liquid absorption performance of the super absorbent resin after absorbing liquid.

[0037] According to some preferred embodiments, repeated granulation is performed at least 5 times, for example, preferably 5 to 9 times; in the present invention, it is preferred that repeated granulation is performed at least 5 times. The present invention finds that if the number of repeated extrusion and crushing is less than 5 times, it is not enough to effectively embed the self-heating functional material into the interior of the colloid particles, resulting in an unstable or incomplete "fish-eye" structure, which will directly affect the embedding depth of the self-heating functional material. In addition, insufficient repeated extrusion times will also lead to uneven distribution of the self-heating functional material, which is easy to concentrate on the surface of the colloid particles or local areas, and cannot form a uniform "fish-eye" structure, which will ultimately affect the heating effect and thermal insulation effect after the super absorbent resin absorbs liquid, as well as the absorption rate of the super absorbent resin.

[0038] According to some preferred embodiments, a meat grinder is used for granulation; specifically, a meat grinder is used for the granulation and the repeated granulation; the drying temperature is 150-180°C (for example, 150°C, 160°C, 170°C or 180°C), and the present invention does not specifically limit the drying time, and the drying can be performed to constant weight; and / or the modified granules with a particle size of 30-80 mesh are obtained by sieving.

[0039] According to some preferred embodiments, the surface treatment temperature is 160-180°C (e.g., 160°C, 170°C or 180°C), the surface treatment time is 20-30min (e.g., 20, 25 or 30min); the surface treatment agent used in the surface treatment is 30-35 parts by weight (e.g., 30, 31, 32, 33, 34 or 35 parts) of butanediol (1,2-butanediol), 2-3 parts by weight (2, 2.5 or 3 parts) of polybutylene glycol diglycidyl ether and 62-68 parts by weight (e.g., 62, 63, 64, 65, 66 , 67 or 68 parts) of deionized water; in the present invention, "parts" refer to "parts by weight". In the specific embodiments and comparative examples, the units of parts by weight can be unified as weight units such as "g" or "kg"; the present invention has no special requirements for polybutylene glycol diglycidyl ether, and can use products that can be directly purchased or products synthesized by existing methods; modified particles with a particle size of 30 to 80 mesh are obtained by sieving, and the amount of the surface treatment agent is 3 to 5% (for example, 3%, 3.5%, 4%, 4.5% or 5%) of the mass of the modified particles.

[0040] In a second aspect, the present invention provides a highly water-absorbent resin having a self-heating function, which is prepared by the preparation method described in the first aspect of the present invention.

[0041] The third aspect of the present invention provides the use of a highly absorbent resin with a self-heating function prepared by the preparation method described in the first aspect of the present invention in a sanitary napkin containing a traditional Chinese medicine component.

[0042] The present invention will be further described below by way of examples, but the protection scope of the present invention is not limited to these embodiments.

[0043] Example 1

[0044] This embodiment provides a highly water-absorbent resin with a self-heating function and a preparation method thereof, wherein the preparation raw materials include the following components:

[0045] 200 parts by weight of acrylic acid, 166 parts by weight of 50wt% sodium hydroxide aqueous solution, 634 parts by weight of deionized water, 0.4 parts by weight of N,N-methylenebisacrylamide, 2 parts by weight of benzoin isopropyl ether, 0.4 parts by weight of self-heating functional material (the self-heating functional material is a mixture of far-infrared ceramic powder and heating iron powder in a mass ratio of 0.02:1) and a surface treatment agent (spray 3 parts by weight of the surface treatment agent for every 100 parts by weight of the modified particles).

[0046] The preparation method comprises the following steps:

[0047] ① Take 200 parts by weight of acrylic acid in a flask, add 634 parts by weight of deionized water to obtain an acrylic acid aqueous solution with a concentration of 24wt%; start stirring, cool the flask with ice water, slowly add 166 parts by weight of a 50% sodium hydroxide aqueous solution, control the system temperature within 50°C, adjust the molar neutralization degree of acrylic acid to 75%, and obtain a mixed solution.

[0048] ② Add 2 parts by weight of benzoin isopropyl ether and 0.4 parts by weight of N,N-methylenebisacrylamide to the mixed solution obtained in step ①, and disperse by ultrasonic until the mixture is uniformly mixed to obtain a polymerization reaction system, transfer the polymerization reaction system to a quartz tube, and then place the quartz tube in an ultraviolet reactor, and perform polymerization reaction for 50 minutes under an ultraviolet lamp with a wavelength of 365nm to obtain a colloid.

[0049] ③ The colloid obtained in step ② is granulated once through a meat grinder to obtain colloid particles, and then 0.4 parts by weight of the self-heating functional material is evenly sprinkled on the surface of the colloid particles and the granulation is repeated 5 times through the meat grinder to obtain modified colloid particles.

[0050] ④ The modified rubber particles are placed in an oven and dried at 160°C, then crushed and sieved to obtain modified particles of 30 to 80 mesh, and then the surface of the modified particles is sprayed with a surface treatment agent and mixed evenly, and then placed in an oven for surface treatment at 160°C for 30 minutes. After the surface treatment, the temperature is cooled to room temperature to obtain a highly absorbent resin with self-heating function; wherein the amount of the surface treatment agent is sprayed with 3 parts by weight of the surface treatment agent per 100 parts by weight of the modified particles, and the surface treatment agent is a mixture of 30 parts by weight of butanediol, 2 parts by weight of polybutylene glycol diglycidyl ether and 68 parts by weight of deionized water.

[0051] Example 2

[0052] This embodiment provides a highly water-absorbent resin with a self-heating function and a preparation method thereof, wherein the preparation raw materials include the following components:

[0053] 220 parts by weight of acrylic acid, 176 parts by weight of 50wt% sodium hydroxide aqueous solution, 604 parts by weight of deionized water, 0.35 parts by weight of dipentaerythritol pentaacrylate, 1.76 parts by weight of isopropyl benzoin, 0.88 parts by weight of self-heating functional material (the self-heating functional material is a mixture of far-infrared ceramic powder and heating iron powder in a mass ratio of 0.03:1.1) and a surface treatment agent (spray 3.5 parts by weight of the surface treatment agent for every 100 parts by weight of the modified particles).

[0054] The preparation method comprises the following steps:

[0055] ① Take 220 parts by weight of acrylic acid in a flask, add 604 parts by weight of deionized water to obtain an acrylic acid aqueous solution with a concentration of 26.7wt%; start stirring, cool the flask with ice water, slowly add 176 parts by weight of a 50% sodium hydroxide aqueous solution, control the system temperature within 50°C, adjust the molar neutralization degree of acrylic acid to 72%, and obtain a mixed solution.

[0056] ② Add 1.76 parts by weight of benzoin isopropyl ether and 0.35 parts by weight of dipentaerythritol pentaacrylate to the mixed solution obtained in step ①, and disperse them by ultrasonic until they are evenly mixed to obtain a polymerization reaction system. Transfer the polymerization reaction system to a quartz tube, and then place the quartz tube in an ultraviolet reactor, and perform polymerization reaction for 45 minutes under an ultraviolet lamp with a wavelength of 365 nm to obtain a colloid.

[0057] ③ The colloid obtained in step ② is granulated once through a meat grinder to obtain colloid particles, and then 0.88 parts by weight of the self-heating functional material is evenly sprinkled on the surface of the colloid particles and the granulation is repeated 6 times through the meat grinder to obtain modified colloid particles.

[0058] ④ The modified rubber particles are placed in an oven and dried at 160°C, then crushed and sieved to obtain modified particles of 30 to 80 mesh, and then the surface of the modified particles is sprayed with a surface treatment agent and mixed evenly, and then placed in an oven for surface treatment at 165°C for 30 minutes. After the surface treatment, the temperature is cooled to room temperature to obtain a highly absorbent resin with self-heating function; wherein the amount of the surface treatment agent is sprayed with 3.5 parts by weight of the surface treatment agent per 100 parts by weight of the modified particles, and the surface treatment agent is a mixture of 31 parts by weight of butanediol, 2.5 parts by weight of polybutylene glycol diglycidyl ether and 66.5 parts by weight of deionized water.

[0059] Example 3

[0060] This embodiment provides a highly water-absorbent resin with a self-heating function and a preparation method thereof, wherein the preparation raw materials include the following components:

[0061] 250 parts by weight of acrylic acid, 194 parts by weight of 50wt% sodium hydroxide aqueous solution, 556 parts by weight of deionized water, 0.3 parts by weight of tetraallyloxyethane, 1.5 parts by weight of isopropyl benzoate, 1.5 parts by weight of self-heating functional material (the self-heating functional material is a mixture of far-infrared ceramic powder and heating iron powder in a mass ratio of 0.04:1) and a surface treatment agent (4 parts by weight of the surface treatment agent is sprayed for every 100 parts by weight of the modified particles).

[0062] The preparation method comprises the following steps:

[0063] ① Take 250 parts by weight of acrylic acid in a flask, add 556 parts by weight of deionized water to obtain an acrylic acid aqueous solution with a concentration of 31wt%; start stirring, cool the flask with ice water, slowly add 194 parts by weight of a 50% sodium hydroxide aqueous solution, control the system temperature within 50°C, adjust the molar neutralization degree of acrylic acid to 70%, and obtain a mixed solution.

[0064] ② Add 1.5 parts by weight of benzoin isopropyl ether and 0.3 parts by weight of tetraallyloxyethane to the mixed solution obtained in step ①, and disperse by ultrasonic until the mixture is uniformly mixed to obtain a polymerization reaction system, transfer the polymerization reaction system to a quartz tube, and then place the quartz tube in an ultraviolet reactor, and perform polymerization reaction under an ultraviolet lamp with a wavelength of 365nm for 40 minutes to obtain a colloid.

[0065] ③ The colloid obtained in step ② is granulated once through a meat grinder to obtain colloid particles, and then 1.5 parts by weight of self-heating functional material is evenly sprinkled on the surface of the colloid particles and the granulation is repeated 7 times through a meat grinder to obtain modified colloid particles.

[0066] ④ The modified rubber particles are placed in an oven and dried at 160°C, then crushed and sieved to obtain modified particles of 30 to 80 mesh, and then the surface of the modified particles is sprayed with a surface treatment agent and mixed evenly, and then placed in an oven for surface treatment at 170°C for 25 minutes. After the surface treatment, the temperature is cooled to room temperature to obtain a highly absorbent resin with self-heating function; wherein the amount of the surface treatment agent is sprayed with 4 parts by weight of the surface treatment agent per 100 parts by weight of the modified particles, and the surface treatment agent is a mixture of 32 parts by weight of butanediol, 2.8 parts by weight of polybutylene glycol diglycidyl ether and 65.2 parts by weight of deionized water.

[0067] The electron microscope image of the super absorbent resin with self-heating function prepared in this embodiment is as follows: Figure 1 shown; from Figure 1It can be seen that the highly water-absorbent resin with self-heating function prepared in the present invention forms a "fish-eye" structure.

[0068] Example 4

[0069] This embodiment provides a highly water-absorbent resin with a self-heating function and a preparation method thereof, wherein the preparation raw materials include the following components:

[0070] 280 parts by weight of acrylic acid, 212 parts by weight of 50wt% aqueous sodium hydroxide solution, 508 parts by weight of deionized water, 0.168 parts by weight of N,N-methylenebisacrylamide, 0.056 parts by weight of dipentaerythritol pentaacrylate, 1.12 parts by weight of isopropyl benzoin, 2.24 parts by weight of self-heating functional material (the self-heating functional material is a mixture of far-infrared ceramic powder and heating iron powder in a mass ratio of 0.06:1.2) and a surface treatment agent (4.5 parts by weight of the surface treatment agent is sprayed on every 100 parts by weight of the modified particles).

[0071] The preparation method comprises the following steps:

[0072] ① Take 280 parts by weight of acrylic acid in a flask, add 508 parts by weight of deionized water to obtain an acrylic acid aqueous solution with a concentration of 35.5wt%; start stirring, cool the flask with ice water, slowly add 212 parts by weight of a 50% sodium hydroxide aqueous solution, control the system temperature within 50°C, adjust the molar neutralization degree of acrylic acid to 68%, and obtain a mixed solution.

[0073] ② Add 1.12 parts by weight of benzoin isopropyl ether, 0.168 parts by weight of N,N-methylenebisacrylamide and 0.056 parts by weight of dipentaerythritol pentaacrylate to the mixed solution obtained in step ①, and disperse by ultrasonic until the mixture is uniformly mixed to obtain a polymerization reaction system, transfer the polymerization reaction system to a quartz tube, and then place the quartz tube in an ultraviolet reactor, and perform polymerization reaction for 35 minutes under an ultraviolet lamp with a wavelength of 365nm to obtain a colloid.

[0074] ③ The colloid obtained in step ② is granulated once through a meat grinder to obtain colloid particles, and then 2.24 parts by weight of self-heating functional material is evenly sprinkled on the surface of the colloid particles and the granulation is repeated 8 times through the meat grinder to obtain modified colloid particles.

[0075] ④ The modified rubber particles are placed in an oven and dried at 160°C, then crushed and sieved to obtain modified particles of 30 to 80 mesh, and then the surface of the modified particles is sprayed with a surface treatment agent and mixed evenly, and then placed in an oven for surface treatment at 175°C for 25 minutes. After the surface treatment, the temperature is cooled to room temperature to obtain a highly absorbent resin with self-heating function; wherein the amount of the surface treatment agent is sprayed with 4.5 parts by weight of the surface treatment agent per 100 parts by weight of the modified particles, and the surface treatment agent is a mixture of 34 parts by weight of butanediol, 3 parts by weight of polybutylene glycol diglycidyl ether and 63 parts by weight of deionized water.

[0076] Example 5

[0077] This embodiment provides a highly water-absorbent resin with a self-heating function and a preparation method thereof, wherein the preparation raw materials include the following components:

[0078] 300 parts by weight of acrylic acid, 217 parts by weight of 50wt% aqueous sodium hydroxide solution, 483 parts by weight of deionized water, 0.15 parts of N,N-methylenebisacrylamide, 0.03 parts by weight of tetraallyloxyethane, 0.9 parts by weight of isopropyl benzoate, 3 parts by weight of self-heating functional material (the self-heating functional material is a mixture of far-infrared ceramic powder and heating iron powder in a mass ratio of 0.07:1.2) and a surface treatment agent (5 parts by weight of the surface treatment agent is sprayed on every 100 parts by weight of the modified particles).

[0079] The preparation method comprises the following steps:

[0080] ① Take 300 parts by weight of acrylic acid in a flask, add 483 parts by weight of deionized water to obtain an acrylic acid aqueous solution with a concentration of 38.3wt%; start stirring, cool the flask with ice water, slowly add 217 parts by weight of a 50% sodium hydroxide aqueous solution, control the system temperature within 50°C, adjust the molar neutralization degree of acrylic acid to 65%, and obtain a mixed solution.

[0081] ② Add 0.9 parts by weight of benzoin isopropyl ether, 0.15 parts by weight of N,N-methylenebisacrylamide and 0.03 parts by weight of tetraallyloxyethane to the mixed solution obtained in step ①, and disperse by ultrasonic until the mixture is uniformly mixed to obtain a polymerization reaction system, transfer the polymerization reaction system to a quartz tube, and then place the quartz tube in an ultraviolet reactor, and perform polymerization reaction for 30 minutes under an ultraviolet lamp with a wavelength of 365nm to obtain a colloid.

[0082] ③ The colloid obtained in step ② is granulated once through a meat grinder to obtain colloid particles, and then 3 parts by weight of self-heating functional material are evenly sprinkled on the surface of the colloid particles and the granulation is repeated 9 times through a meat grinder to obtain modified colloid particles.

[0083] ④ The modified rubber particles are placed in an oven and dried at 160°C, then crushed and sieved to obtain modified particles of 30 to 80 mesh, and then the surface of the modified particles is sprayed with a surface treatment agent and mixed evenly, and then placed in an oven for surface treatment at 180°C for 20 minutes. After the surface treatment, the temperature is cooled to room temperature to obtain a highly absorbent resin with self-heating function; wherein the amount of the surface treatment agent is 5 parts by weight of the surface treatment agent sprayed per 100 parts by weight of the modified particles, and the surface treatment agent is a mixture of 35 parts by weight of butanediol, 3 parts by weight of polybutylene glycol diglycidyl ether and 62 parts by weight of deionized water.

[0084] Example 6

[0085] Embodiment 6 is substantially the same as Embodiment 3, except that:

[0086] In step ③ of preparing the highly water-absorbent resin with self-heating function, the colloid obtained in step ② is granulated once by a meat grinder to obtain colloid particles, and then 1.5 parts by weight of the self-heating functional material is evenly sprinkled on the surface of the colloid particles and granulated three times by a meat grinder to obtain modified colloid particles.

[0087] Example 7

[0088] Example 7 is substantially the same as Example 3, except that:

[0089] When preparing the highly water-absorbent resin with self-heating function, the self-heating functional material used is a mixture of far-infrared ceramic powder and heating iron powder in a mass ratio of 0.02:1.5.

[0090] Example 8

[0091] Embodiment 8 is substantially the same as Embodiment 3, except that:

[0092] When preparing the highly water-absorbent resin with self-heating function, the self-heating functional material used is a mixture of far-infrared ceramic powder and heating iron powder in a mass ratio of 0.08:0.8.

[0093] Example 9

[0094] Example 9 is substantially the same as Example 3, except that:

[0095] When preparing the highly water-absorbent resin with self-heating function, 5 parts by weight of self-heating functional material is used (the self-heating functional material is a mixture of far-infrared ceramic powder and heating iron powder in a mass ratio of 0.04:1).

[0096] Comparative Example 1

[0097] This comparative example provides a super absorbent resin and a preparation method thereof, wherein the preparation raw materials include the following components:

[0098] 200 parts by weight of acrylic acid, 166 parts by weight of 50 wt% sodium hydroxide aqueous solution, 634 parts by weight of deionized water, 0.4 parts by weight of N,N-methylenebisacrylamide, 2 parts by weight of benzoin isopropyl ether and a surface treatment agent (3 parts by weight of the surface treatment agent is sprayed on every 100 parts by weight of the particles).

[0099] The preparation method comprises the following steps:

[0100] ① Take 200 parts by weight of acrylic acid in a flask, add 634 parts by weight of deionized water to obtain an acrylic acid aqueous solution with a concentration of 24wt%; start stirring, cool the flask with ice water, slowly add 166 parts by weight of a 50% sodium hydroxide aqueous solution, control the system temperature within 50°C, adjust the molar neutralization degree of acrylic acid to 75%, and obtain a mixed solution.

[0101] ② Add 2 parts by weight of benzoin isopropyl ether and 0.4 parts by weight of N,N-methylenebisacrylamide to the mixed solution obtained in step ①, and disperse by ultrasonic until the mixture is uniformly mixed to obtain a polymerization reaction system, transfer the polymerization reaction system to a quartz tube, and then place the quartz tube in an ultraviolet reactor, and perform polymerization reaction for 50 minutes under an ultraviolet lamp with a wavelength of 365nm to obtain a colloid.

[0102] ③ The colloid obtained in step ② is granulated once through a meat grinder to obtain colloid particles.

[0103] ④ The colloid particles are placed in an oven and dried at 160°C, and then crushed and sieved to obtain 30-80 mesh particles, and then the surface of the particles is sprayed with a surface treatment agent and mixed evenly, and then placed in an oven for surface treatment at 160°C for 30 minutes. After the surface treatment is completed, it is cooled to room temperature to obtain a highly absorbent resin; wherein the amount of the surface treatment agent is sprayed with 3 parts by weight of the surface treatment agent per 100 parts by weight of the particles, and the surface treatment agent is a mixture of 30 parts by weight of butanediol, 2 parts by weight of polybutylene glycol diglycidyl ether and 68 parts by weight of deionized water.

[0104] Comparative Example 2

[0105] This comparative example provides a super absorbent resin and a preparation method thereof, wherein the preparation raw materials include the following components:

[0106] 220 parts by weight of acrylic acid, 176 parts by weight of 50 wt% sodium hydroxide aqueous solution, 604 parts by weight of deionized water, 0.35 parts by weight of dipentaerythritol pentaacrylate, 1.76 parts by weight of benzoin isopropyl ether and a surface treatment agent (3.5 parts by weight of the surface treatment agent is sprayed per 100 parts by weight of the particles).

[0107] The preparation method comprises the following steps:

[0108] ① Take 220 parts by weight of acrylic acid in a flask, add 604 parts by weight of deionized water to obtain an acrylic acid aqueous solution with a concentration of 26.7wt%; start stirring, cool the flask with ice water, slowly add 176 parts by weight of a 50% sodium hydroxide aqueous solution, control the system temperature within 50°C, adjust the molar neutralization degree of acrylic acid to 72%, and obtain a mixed solution.

[0109] ② Add 1.76 parts by weight of benzoin isopropyl ether and 0.35 parts by weight of dipentaerythritol pentaacrylate to the mixed solution obtained in step ①, and disperse them by ultrasonic until they are evenly mixed to obtain a polymerization reaction system. Transfer the polymerization reaction system to a quartz tube, and then place the quartz tube in an ultraviolet reactor, and perform polymerization reaction for 45 minutes under an ultraviolet lamp with a wavelength of 365 nm to obtain a colloid.

[0110] ③ The colloid obtained in step ② is granulated once through a meat grinder to obtain colloid particles.

[0111] ④ The colloid particles are placed in an oven and dried at 160°C, and then crushed and sieved to obtain 30-80 mesh particles, and then the surface of the particles is sprayed with a surface treatment agent and mixed evenly, and then placed in an oven for surface treatment at 165°C for 30 minutes. After the surface treatment is completed, it is cooled to room temperature to obtain a highly absorbent resin; wherein the amount of the surface treatment agent is sprayed with 3.5 parts by weight of the surface treatment agent per 100 parts by weight of the particles, and the surface treatment agent is a mixture of 31 parts by weight of butanediol, 2.5 parts by weight of polybutylene glycol diglycidyl ether and 66.5 parts by weight of deionized water.

[0112] Comparative Example 3

[0113] This comparative example provides a super absorbent resin and a preparation method thereof, wherein the preparation raw materials include the following components:

[0114] 250 parts by weight of acrylic acid, 194 parts by weight of 50 wt% sodium hydroxide aqueous solution, 556 parts by weight of deionized water, 0.3 parts by weight of tetraallyloxyethane, 1.5 parts by weight of benzoin isopropyl ether and a surface treatment agent (4 parts by weight of the surface treatment agent is sprayed per 100 parts by weight of the particles).

[0115] The preparation method comprises the following steps:

[0116] ① Take 250 parts by weight of acrylic acid in a flask, add 556 parts by weight of deionized water to obtain an acrylic acid aqueous solution with a concentration of 31wt%; start stirring, cool the flask with ice water, slowly add 194 parts by weight of a 50% sodium hydroxide aqueous solution, control the system temperature within 50°C, adjust the molar neutralization degree of acrylic acid to 70%, and obtain a mixed solution.

[0117] ② Add 1.5 parts by weight of benzoin isopropyl ether and 0.3 parts by weight of tetraallyloxyethane to the mixed solution obtained in step ①, and disperse by ultrasonic until the mixture is uniformly mixed to obtain a polymerization reaction system, transfer the polymerization reaction system to a quartz tube, and then place the quartz tube in an ultraviolet reactor, and perform polymerization reaction under an ultraviolet lamp with a wavelength of 365nm for 40 minutes to obtain a colloid.

[0118] ③ The colloid obtained in step ② is granulated once through a meat grinder to obtain colloid particles.

[0119] ④ The colloid particles are placed in an oven and dried at 160°C, and then crushed and sieved to obtain 30-80 mesh particles, and then the surface of the particles is sprayed with a surface treatment agent and mixed evenly, and then placed in an oven for surface treatment at 170°C for 25 minutes. After the surface treatment is completed, it is cooled to room temperature to obtain a highly absorbent resin; wherein the amount of the surface treatment agent is sprayed with 4 parts by weight of the surface treatment agent per 100 parts by weight of the particles, and the surface treatment agent is a mixture of 32 parts by weight of butanediol, 2.8 parts by weight of polybutylene glycol diglycidyl ether and 65.2 parts by weight of deionized water.

[0120] The electron microscope image of the super absorbent resin prepared in this comparative example is as follows: Figure 2 shown.

[0121] Comparative Example 4

[0122] This comparative example provides a super absorbent resin and a preparation method thereof, wherein the preparation raw materials include the following components:

[0123] 280 parts by weight of acrylic acid, 212 parts by weight of 50wt% sodium hydroxide aqueous solution, 508 parts by weight of deionized water, 0.168 parts by weight of N,N-methylenebisacrylamide, 0.056 parts by weight of dipentaerythritol pentaacrylate, 1.12 parts by weight of benzoin isopropyl ether and a surface treatment agent (4.5 parts by weight of the surface treatment agent is sprayed on every 100 parts by weight of the particles).

[0124] The preparation method comprises the following steps:

[0125] ① Take 280 parts by weight of acrylic acid in a flask, add 508 parts by weight of deionized water to obtain an acrylic acid aqueous solution with a concentration of 35.5wt%; start stirring, cool the flask with ice water, slowly add 212 parts by weight of a 50% sodium hydroxide aqueous solution, control the system temperature within 50°C, adjust the molar neutralization degree of acrylic acid to 68%, and obtain a mixed solution.

[0126] ② Add 1.12 parts by weight of benzoin isopropyl ether, 0.168 parts by weight of N,N-methylenebisacrylamide and 0.056 parts by weight of dipentaerythritol pentaacrylate to the mixed solution obtained in step ①, and disperse by ultrasonic until the mixture is uniformly mixed to obtain a polymerization reaction system, transfer the polymerization reaction system to a quartz tube, and then place the quartz tube in an ultraviolet reactor, and perform polymerization reaction for 35 minutes under an ultraviolet lamp with a wavelength of 365nm to obtain a colloid.

[0127] ③ The colloid obtained in step ② is granulated once through a meat grinder to obtain colloid particles.

[0128] ④ The modified rubber particles are placed in an oven and dried at 160°C, and then crushed and sieved to obtain 30-80 mesh particles, and then the surface of the particles is sprayed with a surface treatment agent and mixed evenly, and then placed in an oven for surface treatment at 175°C for 25 minutes. After the surface treatment is completed, it is cooled to room temperature to obtain a highly absorbent resin; wherein the amount of the surface treatment agent is sprayed with 4.5 parts by weight of the surface treatment agent per 100 parts by weight of the particles, and the surface treatment agent is a mixture of 34 parts by weight of butanediol, 3 parts by weight of polybutylene glycol diglycidyl ether and 63 parts by weight of deionized water.

[0129] Comparative Example 5

[0130] This comparative example provides a super absorbent resin and a preparation method thereof, wherein the preparation raw materials include the following components:

[0131] 300 parts by weight of acrylic acid, 217 parts by weight of 50 wt% aqueous sodium hydroxide solution, 483 parts by weight of deionized water, 0.15 parts of N,N-methylenebisacrylamide, 0.03 parts by weight of tetraallyloxyethane, 0.9 parts by weight of benzoin isopropyl ether and a surface treatment agent (5 parts by weight of the surface treatment agent is sprayed on every 100 parts by weight of the particles).

[0132] The preparation method comprises the following steps:

[0133] ① Take 300 parts by weight of acrylic acid in a flask, add 483 parts by weight of deionized water to obtain an acrylic acid aqueous solution with a concentration of 38.3wt%; start stirring, cool the flask with ice water, slowly add 217 parts by weight of a 50% sodium hydroxide aqueous solution, control the system temperature within 50°C, adjust the molar neutralization degree of acrylic acid to 65%, and obtain a mixed solution.

[0134] ② Add 0.9 parts by weight of benzoin isopropyl ether, 0.15 parts by weight of N,N-methylenebisacrylamide and 0.03 parts by weight of tetraallyloxyethane to the mixed solution obtained in step ①, and disperse by ultrasonic until the mixture is uniformly mixed to obtain a polymerization reaction system, transfer the polymerization reaction system to a quartz tube, and then place the quartz tube in an ultraviolet reactor, and perform polymerization reaction for 30 minutes under an ultraviolet lamp with a wavelength of 365nm to obtain a colloid.

[0135] ③ The colloid obtained in step ② is granulated once through a meat grinder to obtain colloid particles.

[0136] ④ The colloid particles are placed in an oven and dried at 160°C, and then crushed and sieved to obtain 30-80 mesh particles, and then the surface of the particles is sprayed with a surface treatment agent and mixed evenly, and then placed in an oven for surface treatment at 180°C for 20 minutes. After the surface treatment is completed, it is cooled to room temperature to obtain a highly absorbent resin; wherein the amount of the surface treatment agent is sprayed with 5 parts by weight of the surface treatment agent per 100 parts by weight of the particles, and the surface treatment agent is a mixture of 35 parts by weight of butanediol, 3 parts by weight of polybutylene glycol diglycidyl ether and 62 parts by weight of deionized water.

[0137] Comparative Example 6

[0138] This comparative example provides a super absorbent resin and a preparation method thereof, wherein the preparation raw materials include the following components:

[0139] 250 parts by weight of acrylic acid, 194 parts by weight of 50wt% aqueous sodium hydroxide solution, 556 parts by weight of deionized water, 0.3 parts by weight of tetraallyloxyethane, 1.5 parts by weight of isopropyl benzoate, 1.5 parts by weight of self-heating functional material (the self-heating functional material is a mixture of far-infrared ceramic powder and heating iron powder in a mass ratio of 0.04:1) and a surface treatment agent (4 parts by weight of the surface treatment agent is sprayed on every 100 parts by weight of the particulate matter).

[0140] The preparation method comprises the following steps:

[0141] ① Take 250 parts by weight of acrylic acid in a flask, add 556 parts by weight of deionized water to obtain an acrylic acid aqueous solution with a concentration of 31wt%; start stirring, cool the flask with ice water, slowly add 194 parts by weight of a 50% sodium hydroxide aqueous solution, control the system temperature within 50°C, adjust the molar neutralization degree of acrylic acid to 70%, and obtain a mixed solution.

[0142] ② Add 1.5 parts by weight of benzoin isopropyl ether, 0.3 parts by weight of tetraallyloxyethane and 1.5 parts by weight of self-heating functional material to the mixed solution obtained in step ①, and ultrasonically disperse until the mixture is uniformly mixed to obtain a polymerization reaction system, transfer the polymerization reaction system to a quartz tube, and then place the quartz tube in an ultraviolet reactor, and perform polymerization reaction for 40 minutes under an ultraviolet lamp with a wavelength of 365nm to obtain a colloid.

[0143] ③ The colloid obtained in step ② is granulated once through a meat grinder to obtain colloid particles.

[0144] ④ The colloid particles are placed in an oven and dried at 160°C, and then crushed and sieved to obtain 30-80 mesh particles, and then the surface of the particles is sprayed with a surface treatment agent and mixed evenly, and then placed in an oven for surface treatment at 170°C for 25 minutes. After the surface treatment is completed, it is cooled to room temperature to obtain a highly absorbent resin; wherein the amount of the surface treatment agent is sprayed with 4 parts by weight of the surface treatment agent per 100 parts by weight of the particles, and the surface treatment agent is a mixture of 32 parts by weight of butanediol, 2.8 parts by weight of polybutylene glycol diglycidyl ether and 65.2 parts by weight of deionized water.

[0145] Comparative Example 7

[0146] This comparative example provides a super absorbent resin and a preparation method thereof, wherein the preparation raw materials include the following components:

[0147] 250 parts by weight of acrylic acid, 194 parts by weight of 50wt% aqueous sodium hydroxide solution, 556 parts by weight of deionized water, 0.3 parts by weight of tetraallyloxyethane, 1.5 parts by weight of isopropyl benzoate, 1.5 parts by weight of self-heating functional material (the self-heating functional material is a mixture of far-infrared ceramic powder and heating iron powder in a mass ratio of 0.04:1) and a surface treatment agent (4 parts by weight of the surface treatment agent is sprayed on every 100 parts by weight of the particulate matter).

[0148] The preparation method comprises the following steps:

[0149] ① Take 250 parts by weight of acrylic acid in a flask, add 556 parts by weight of deionized water to obtain an acrylic acid aqueous solution with a concentration of 31wt%; start stirring, cool the flask with ice water, slowly add 194 parts by weight of a 50% sodium hydroxide aqueous solution, control the system temperature within 50°C, adjust the molar neutralization degree of acrylic acid to 70%, and obtain a mixed solution.

[0150] ② Add 1.5 parts by weight of benzoin isopropyl ether and 0.3 parts by weight of tetraallyloxyethane to the mixed solution obtained in step ①, and disperse by ultrasonic until the mixture is uniformly mixed to obtain a polymerization reaction system, transfer the polymerization reaction system to a quartz tube, and then place the quartz tube in an ultraviolet reactor, and perform polymerization reaction under an ultraviolet lamp with a wavelength of 365nm for 40 minutes to obtain a colloid.

[0151] ③ The colloid obtained in step ② is granulated once through a meat grinder to obtain colloid particles.

[0152] ④ The colloid particles are placed in an oven and dried at 160°C, and then crushed and sieved to obtain 30-80 mesh particles, and then the surface of the particles is sprayed with a surface treatment agent and mixed evenly, and then placed in an oven for surface treatment at 170°C for 25 minutes. After the surface treatment is completed, it is cooled to room temperature to obtain a highly absorbent resin; wherein the amount of the surface treatment agent is sprayed with 4 parts by weight of the surface treatment agent per 100 parts by weight of the particles, and the surface treatment agent is mixed with 32 parts by weight of butanediol, 2.8 parts by weight of polybutylene glycol diglycidyl ether, 65.2 parts by weight of deionized water and 1.5 parts by weight of self-heating functional material.

[0153] Comparative Example 8

[0154] This comparative example provides a super absorbent resin and a preparation method thereof, wherein the preparation raw materials include the following components:

[0155] 250 parts by weight of acrylic acid, 194 parts by weight of 50wt% aqueous sodium hydroxide solution, 556 parts by weight of deionized water, 0.3 parts by weight of tetraallyloxyethane, 1.5 parts by weight of isopropyl benzoate, 1.5 parts by weight of self-heating functional material (the self-heating functional material is a mixture of far-infrared ceramic powder and heating iron powder in a mass ratio of 0.04:1) and a surface treatment agent (4 parts by weight of the surface treatment agent is sprayed on every 100 parts by weight of the particulate matter).

[0156] The preparation method comprises the following steps:

[0157] ① Take 250 parts by weight of acrylic acid in a flask, add 556 parts by weight of deionized water to obtain an acrylic acid aqueous solution with a concentration of 31wt%; start stirring, cool the flask with ice water, slowly add 194 parts by weight of a 50% sodium hydroxide aqueous solution, control the system temperature within 50°C, adjust the molar neutralization degree of acrylic acid to 70%, and obtain a mixed solution.

[0158] ② Add 1.5 parts by weight of benzoin isopropyl ether and 0.3 parts by weight of tetraallyloxyethane to the mixed solution obtained in step ①, and disperse by ultrasonic until the mixture is uniformly mixed to obtain a polymerization reaction system, transfer the polymerization reaction system to a quartz tube, and then place the quartz tube in an ultraviolet reactor, and perform polymerization reaction under an ultraviolet lamp with a wavelength of 365nm for 40 minutes to obtain a colloid.

[0159] ③ The colloid obtained in step ② is granulated once through a meat grinder to obtain colloid particles.

[0160] ④ The granules are placed in an oven and dried at 160°C, then crushed and sieved to obtain granules of 30 to 80 mesh, and then the surface of the granules is sprayed with a surface treatment agent and mixed evenly, and then placed in an oven for surface treatment at 170°C for 25 minutes. After the surface treatment, the temperature is cooled to room temperature to obtain resin particles; wherein the amount of the surface treatment agent is sprayed with 4 parts by weight of the surface treatment agent per 100 parts by weight of the granules, and the surface treatment agent is a mixture of 32 parts by weight of butanediol, 2.8 parts by weight of polybutylene glycol diglycidyl ether and 65.2 parts by weight of deionized water.

[0161] ⑤ Add 1.5 parts by weight of self-heating functional material to the resin particles obtained in step ④ and mix well to obtain a highly absorbent resin.

[0162] The present invention tests the water absorption rate and water retention rate of the super absorbent resin finally obtained in each embodiment and each comparative example, and the results are shown in Table 1; the present invention tests the absorption speed, blood absorption temperature difference and heat preservation time of the super absorbent resin finally obtained in each embodiment and each comparative example, and the results are shown in Table 1. The testing method is: in a constant temperature environment of 37.5°C, 2g of super absorbent resin is poured into 25mL of animal blood at 37.5°C and stirred, and timing is started at the same time until there are no lumps and white particles, and the mixture is allowed to stand until the animal blood is completely absorbed, and the time for the absorption to be completed is recorded as the absorption speed, in seconds; the temperature change is recorded, and when the temperature no longer rises, the temperature difference is obtained by subtracting the initial temperature of 37.5°C from the final temperature, and after reaching the highest temperature, the duration of the final temperature is the heat preservation time.

[0163] Table 1: Performance comparison results of the super absorbent resins finally obtained in each embodiment and each comparative example.

[0164]

[0165]

[0166] From the results in Table 1, it can be seen that the super absorbent resin with self-heating function prepared in Examples 1 to 5 of the present invention can effectively improve the absorption speed of the super absorbent resin compared with the conventional super absorbent resin. The present invention adds a self-heating functional material. The super absorbent resin prepared in the preferred embodiments 1 to 5 of the present invention can increase the temperature of the entire system by 3.5 to 4.5°C after absorbing liquid, and can stably maintain the temperature of the system at 41-42°C for about thirty minutes. It is well known that the fumigation temperature of traditional Chinese medicine is preferably 39-42°C, and the fumigation time of traditional Chinese medicine should generally not exceed 40 minutes each time. Therefore, the super absorbent resin with self-heating function in the present invention is applied to functional sanitary napkins, especially traditional Chinese medicine sanitary napkins, which can fully and effectively exert the efficacy of traditional Chinese medicine and can play a significant role in improving the performance of sanitary napkins.

[0167] Parts of the present invention that are not described in detail are well known to those skilled in the art.

[0168] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a highly water-absorbent resin having a self-heating function, characterized in that: The preparation method comprises the following steps: (1) preparing an acrylic acid solution with a concentration of 20 to 40 wt %, and then adding a sodium hydroxide solution to adjust the neutralization degree of the acrylic acid to 65 to 75%, to obtain a mixed solution; (2) adding an initiator and a cross-linking agent to the mixed solution and mixing them evenly, and then performing a polymerization reaction under ultraviolet light to obtain a colloid; (3) granulating the colloid to obtain colloid particles, and then evenly spreading the self-heating functional material on the surface of the colloid particles and repeatedly granulating to obtain modified colloid particles; (4) The modified rubber particles are dried, crushed, and sieved in sequence, and then surface treated to obtain a highly absorbent resin with a self-heating function.

2. The preparation method according to claim 1, characterized in that: The concentration of the acrylic acid solution is 24 to 39 wt %; and / or In the process of adjusting the neutralization degree of acrylic acid to 65-75%, the temperature of the system is controlled not to exceed 50°C.

3. The preparation method according to claim 1, characterized in that: The initiator is benzoin isopropyl ether; and / or The amount of the initiator used is 0.2-1% of the mass of the acrylic acid.

4. The preparation method according to claim 1, characterized in that: The crosslinking agent is one or more of N,N-methylenebisacrylamide, glycidyl methacrylate, dipentaerythritol pentaacrylate, triallyl isocyanurate, and tetraallyloxyethane; and / or The amount of the cross-linking agent used is 0.05-0.2% of the mass of the acrylic acid.

5. The preparation method according to claim 1, characterized in that: The polymerization reaction is carried out under an ultraviolet lamp with a wavelength of 365 nm, and the polymerization reaction time is 30 to 50 minutes.

6. The preparation method according to claim 1, characterized in that: The self-heating functional material is a mixture of far-infrared ceramic powder and heating iron powder, and the mass ratio of the far-infrared ceramic powder to the heating iron powder is (0.02-0.08): (1-1.2); and / or The amount of the self-heating functional material is 0.1-1% of the mass of the acrylic acid.

7. The preparation method according to claim 1, characterized in that: Repeat granulation at least 5 times; Granulation is performed using a meat grinder; The drying temperature is 150-180°C; and / or The modified particles with a particle size of 30 to 80 mesh are obtained by sieving.

8. The preparation method according to claim 1, characterized in that: The surface treatment temperature is 160-180°C, and the surface treatment time is 20-30 minutes; The surface treatment agent used in the surface treatment is composed of 30 to 35 parts by weight of butanediol, 2 to 3 parts by weight of polybutylene glycol diglycidyl ether and 62 to 68 parts by weight of deionized water; The modified particles with a particle size of 30 to 80 meshes are obtained by sieving, and the amount of the surface treatment agent used is 3 to 5% of the mass of the modified particles.

9. A highly water-absorbent resin having a self-heating function obtained by the preparation method according to any one of claims 1 to 8.

10. Use of the super absorbent resin with self-heating function obtained by the preparation method according to any one of claims 1 to 8 in sanitary napkins containing traditional Chinese medicine ingredients.

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