SUPER ABSORBENT RESIN AND PREPARATION METHOD THEREOF

Abstract

The present invention relates to a sodium polyacrylate super absorbent resin for blood absorption with a gradual hierarchical structure. When a blood simulant solution is used as the detection medium, according to ISO 19699-1:2017(E), the absorption capacity of the blood simulant solution is ≥18.0 g/g, Preferably ≥18.5 g/g; the absorption rate of the blood simulant solution is ≤45 s, preferably ≤40 s, more preferably ≤38 s; when human blood is used as the detection medium, according to ISO 19699-1:2017(E), the absorption capacity of the human blood is ≥8.0 g/g, preferably ≥8.3 g/g, more preferably ≥8.6 g/g; the absorption rate of the human blood is ≤45 s, preferably ≤40 s, more preferably ≤35 s, most preferably ≤25 s. The present invention combines organic cross-linking and inorganic cross-linking for surface modification, so that the resin has a gradual hierarchical structure, thereby ensuring that it has excellent blood absorption properties, while also having excellent water absorption properties and gel strength, and other performance.

Claims

1. A super absorbent resin, wherein, when a blood simulant solution is used as the detection medium, according to ISO 19699-1:2017(E), the absorption capacity of the blood simulant solution is ≥18.0 g/g, preferably ≥18.5 g/g; the absorption rate of the blood simulant solution is ≤45 s, preferably ≤40 s, more preferably ≤38 s.

2. A super absorbent resin, wherein, when human blood is used as the detection medium, according to ISO 19699-1:2017(E), the absorption capacity of the human blood is ≥8.0 g/g, preferably ≥8.3 g/g, more preferably ≥8.6 g/g; the absorption rate of the human blood is ≤45 s, preferably ≤40 s, more preferably ≤35 s, most preferably ≤25 s.

3. The super absorbent resin according to claim 2, wherein, when a blood simulant solution is used as the detection medium, according to ISO 19699-1:2017(E), the absorption capacity of the blood simulant solution is ≥18.0 g/g, preferably ≥18.5 g/g; the absorption rate of the blood simulant solution is ≤45 s, preferably ≤40 s, more preferably ≤38 s.

4. The super absorbent resin according to claim 1, wherein, with respect to the super absorbent resin, the residual monomer content is ≤1000 mg/kg, preferably ≤800 mg/kg, calculated as acrylic acid; the volatile content is ≤10.0%; the pH value is 5.0-8.0; concerning the particle size distribution, the content of the sample with particle size <150 μm is ≤5 wt %, the content of sample with particle size <106 μm is ≤1 wt %; the bulk density is 0.65 g/cm.sup.3-0.80 g/cm.sup.3; and/or the whiteness is ≥70%.

5. The super absorbent resin according to claim 1, wherein characterized in that, the super absorbent resin is surface modified sodium polyacrylate resin.

6. The super absorbent resin according to claim 5, wherein the surface modification includes surface crosslinking using polyvalent metal salt solution A, preferably aluminum salt solution, calcium salt solution, magnesium salt solution or zinc salt solution, more preferably aluminum salt solution, and solution B prepared from compounds containing epoxy groups and solvents.

7. A preparation method of super absorbent resin, wherein the method comprises the following steps: (1) weigh the surface dispersant; (2) weigh the polyvalent metal salt, preferably aluminum salt, calcium salt, magnesium salt or zinc salt, more preferably aluminum salt, and prepare it into solution A; (3) weigh the compound containing epoxy groups, and prepare it into solution B; (4) mix the surface dispersant, the solution A, the solution B and sodium polyacrylate resin; (5) carry out the crosslinking reaction to obtain surface modified sodium polyacrylate super absorbent resin with a gradual hierarchical structure.

8. The method according to claim 7, wherein the particle size of the sodium polyacrylate resin is 120 μm-830 μm, more preferably 150 μm-380 μm.

9. The method according to claim 7, wherein the surface dispersant is selected from methanol, ethanol, acetone or fumed silica, preferably methanol or ethanol; the mass ratio of the surface dispersant to the sodium polyacrylate resin is (1-15):100, preferably (1-10):100, and more preferably (1-5):100.

10. The method according to claim 7, wherein the aluminum salt of solution A is selected from aluminum chloride, aluminum sulfate, ammonium aluminum sulfate, aluminum nitrate and alum, preferably aluminum sulfate or ammonium aluminum sulfate; the solvent of solution A is selected from water, acetone and polyols; preferably water and/or glycerol, and the mass ratio of glycerol to water is (0-0.7):1; the mass concentration of aluminum salt in solution A is 3%-25%, preferably 10%-25%, more preferably 10%-20%; the mass ratio of aluminum salt to sodium polyacrylate resin is (0.010-0.050):1, preferably (0.025-0.030):1.

11. The method according to claim 7, wherein the compound containing epoxy groups of solution B is selected from epoxy resin, epichlorohydrin, propylene oxide, glycidyl ether, polyethylene glycol diglycidyl ether and ethylene glycol diglycidyl ether, preferably epichlorohydrin, glycidyl ether or polyethylene glycol diglycidyl ether; the solvent of solution B is selected from alcohols and ketones, preferably methanol, ethanol, isopropanol, acetone or butanone, more preferably ethanol or methanol; the mass concentration of the compound containing epoxy groups in solution B is 10%-25%; the mass ratio of the compound containing epoxy group to the sodium polyacrylate resin is (0.001-0.006):1, preferably (0.002-0.004):1, more preferably 0.003:1.

12. The method according to claim 7, wherein in step (4), the surface dispersant, solution A, solution B are mixed uniformly, and then mixed with sodium polyacrylate resin; or, the surface dispersant, solution A, solution B are mixed with sodium polyacrylate resin in sequence; or, the surface dispersant, solution B, solution A are mixed with sodium polyacrylate resin in sequence; or, the surface dispersant and the solution B are mixed uniformly with the sodium polyacrylate resin, and then the solution A and the previously obtained mixture are mixed uniformly.

13. The method according to claim 12, wherein the surface dispersant and solution B are mixed firstly, and then mix with the sodium polyacrylate resin uniformly at room temperature; subsequently, the solution A is heated to 60-100° C., preferably 60-80° C., and mixed uniformly with the mixture obtained as described above at the said temperature.

14. The method according to claim 7, wherein the temperature of the crosslinking reaction in step (5) is 50-200° C., preferably 80-185° C., more preferably 120-140° C.; and the time is 20-210 min, preferably 25-120 min, more preferably 30-90 min.

15. The method according to claim 7, wherein when human blood is used as the detection medium, according to ISO 19699-1:2017(E), the absorption capacity of the human blood is ≥8.0 g/g, preferably ≥8.3 g/g, more preferably ≥8.6 g/g; the absorption rate of the human blood is ≤45 s, preferably ≤40 s, more preferably ≤35 s, most preferably ≤25 s.

16. The method according to claim 15, wherein when a blood simulant solution is used as the detection medium, according to ISO 19699-1:2017(E), the absorption capacity of the blood simulant solution is ≥18.0 g/g, preferably ≥18.5 g/g, the absorption rate of the blood simulant solution is ≤45 s, preferably ≤40 s, more preferably ≤38 s.

17. The method according to claim 15, wherein with respect to the super absorbent resin, the residual monomer content is ≤1000 mg/kg, preferably ≤800 mg/kg, calculated as acrylic acid; the volatile content is ≤10.0%; the pH value is 5.0-8.0; concerning the particle size distribution, the content of the sample with particle size <150 μm is ≤5 wt %, the content of sample with particle size <106 μm is ≤1 wt %; the bulk density is 0.65 g/cm.sup.3-0.80 g/cm.sup.3; and/or the whiteness is ≥70%.

18. A super absorbent product, wherein the product contains the super absorbent resin according to claim 1.

19. The product according to claim 18, wherein the product comprises sanitary napkins and/or blood-absorbing products for medical use.

20. The use of the product according to claim 18, wherein it is used for absorbing blood.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0032] Hereinafter, the embodiments of the present invention will be further described, wherein each embodiment is only an exemplary and/or preferred embodiment of the present invention, and is not intended to constitute a limitation on the scope of the present invention. Those skilled in the art can make many different improvements and modifications based on the above description and the following description of the embodiments, which will not depart from the spirit and essence of the present invention.

[0033] Accordingly, the scope of the present invention is only intended to be limited by the scope of protection required by the claims.

Example 1

[0034] (1) Weigh methanol, the mass ratio of methanol to sodium polyacrylate resin is 1:20;

[0035] (2) Weigh aluminum sulfate and prepare it into aqueous solution A with a mass concentration of 25%; the mass ratio of aluminum sulfate to sodium polyacrylate resin is 0.025:1;

[0036] (3) Weigh polyethylene glycol diglycidyl ether and prepare it into ethanol solution B with a mass concentration of 20%; the mass ratio of polyethylene glycol diglycidyl ether to sodium polyacrylate resin is 0.0030:1;

[0037] (4) Methanol and solution B are well mixed firstly, then mixed uniformly with sodium polyacrylate resin at room temperature; then, solution A is heated to 60° C. and mixed with the mixture above mentioned uniformly at 60° C.;

[0038] (5) The resin processed in step (4) is put into a tray, entered an oven for cross-linking reaction, the reaction temperature is 120° C., and the reaction time is 90 minutes, to obtain the surface-modified super absorbent resin of the present invention.

Example 2

[0039] The concentration of solution A in Example 1 is changed to 20%, the concentration of solution B is 25%. The others are the same as in Example 1.

Example 3

[0040] The solution A in Example 1 is changed to an aqueous solution of ammonium alum (ammonium aluminum sulfate dodecahydrate) with a mass concentration of 25%. Entered into the oven for cross-linking reaction, the reaction temperature is 140° C., the reaction time is 60 minutes. The others are the same as in Example 1.

Example 4

[0041] The solution A in Example 2 is changed to an aqueous solution of ammonium alum (ammonium aluminum sulfate dodecahydrate) with a mass concentration of 20%. Entered into the oven for cross-linking reaction, the reaction temperature is 140° C., the reaction time is 60 minutes. The others are the same as in Example 2.

Example 5

[0042] The solution A in Example 4 is changed to a solution of ammonium alum (ammonium aluminum sulfate dodecahydrate) in water and glycerol, the mass concentration of which is 11%, and the mass ratio of glycerol to water is 1:6. Enter the oven for cross-linking reaction, the reaction temperature is 140° C., and the reaction time is 50 minutes. The others are the same as in Example 4.

Example 6

[0043] The mass ratio of methanol to sodium polyacrylate resin in Example 1 is changed to 1:50, solution B is changed to an ethanol solution with an epichlorohydrin mass concentration of 25%, and the solvent of solution A was glycerol and water, the mass ratio of glycerol to water is 3:5. The others are the same as in Example 1.

Example 7

[0044] The solution A in Example 6 is changed to a solution of ammonium alum (ammonium aluminum sulfate dodecahydrate) in water and glycerol, with a mass concentration of 11%, and the mass ratio of glycerol to water was 1:6. Entered the oven for cross-linking reaction, the reaction temperature is 140° C., and the reaction time is 50 minutes. The others are the same as in Example 6.

Example 8

[0045] The surfactant in Example 7 is changed to ethanol, and the mass ratio of ethanol to sodium polyacrylate resin is changed to 3:100. The others are the same as in Example 7.

Example 9

[0046] After mixing methanol, solution A, and solution B in Example 1, they were mixed with sodium polyacrylate resin and mixed uniformly. Solution A is changed to alum aqueous solution, and the mass ratio of methanol to sodium polyacrylate resin is changed to 1:10. Other conditions are the same Example 1.

Example 10

[0047] The methanol, solution B, and solution A in Example 1 were mixed with sodium polyacrylate resin in sequence, and the solution A is changed to an aqueous solution of aluminum nitrate. Other conditions are the same as in Example 1.

Example 11

[0048] After mixing the methanol, solution A, and solution B in Example 3, they are mixed with sodium polyacrylate resin and mixed uniformly. The compound containing epoxy group of solution B is changed to glycidyl ether, the mass ratio of glycidyl ether to sodium polyacrylate resin is 0.0060:1. Other conditions are the same as in Example 3.

Example 12

[0049] The methanol, solution B, and solution A in Example 3 are mixed with the sodium polyacrylate resin in sequence. Other conditions are the same as in Example 3.

Example 13

[0050] The mass ratio of methanol to sodium polyacrylate resin in Example 1 is changed to 3:20, the reaction temperature is changed to 185° C., the reaction time is 20 minutes, and the solution B is changed to a methanol solution of epichlorohydrin with a mass solubility of 10%, the ratio of propylene oxide to sodium polyacrylate resin is 0.00101. Other conditions are the same as in Example 1.

Example 14

[0051] The mass concentration of aluminum sulfate in solution A in Example 1 is changed to 10%, and the mass ratio of aluminum sulfate to sodium polyacrylate resin is changed to 0.010′1. Other conditions are the same as in Example 1.

Example 15

[0052] The mass concentration of ammonium alum of solution A in Example 3 is changed to 3%, and the mass ratio of ammonium alum to polyacrylic acid resin is changed to 0.045:1. Other conditions were the same as in Example 3.

Example 16

[0053] The heating temperature of solution A in Example 1 is changed to 80° C., the heating temperature in step (5) is changed to 80° C., and the time is changed to 180 minutes. Other conditions are the same as in Example 1.

Comparative Example 1

[0054] The specific process is carried out as disclosed in CN 1696181A, and the steps are as follows:

[0055] 1) Preparation of Treatment Solution A:

[0056] Choose acetone as the dispersant, epichlorohydrin as the cross-linking agent, and DMP-30 as the cross-linking accelerator; put the dispersant, cross-linking agent, and cross-linking accelerator in a glass container and stir to prepare treatment solution A. The mass concentration of epichlorohydrin is 12%;

[0057] 2) Preparation of Treatment Solution B:

[0058] Put the deionized water in a glass container and heat it to 90° C., weigh the aluminum sulfate salt and the second cross-linking agent glycerin, add the deionized water and stir to prepare treatment solution B, the mass concentration of aluminum sulfate is 15%;

[0059] 3) Treatment of Resin by Treatment Liquid:

[0060] Weigh 60 kg of sodium polyacrylate resin and place it in a 300 rpm stirrer. While stirring, spray treatment liquid A and treatment liquid B on the surface of the water absorption resin in sequence, and then put the resin into the tray and heat it in the oven for crosslinking reaction, the reaction temperature is 120° C., the reaction time is 100 minutes, and the surface modification of the sodium polyacrylate resin is obtained.

[0061] Hereinafter, various properties/indices and test methods of the super absorbent resin of the present invention prepared according to Examples 1-16 and the sodium polyacrylate resin prepared according to Comparative Example 1 will be described in detail.

[0062] 1 Blood Absorption Capacity, Blood Absorption Rate and Gel Strength

[0063] The detection medium uses human blood and blood simulant solution respectively to test the blood absorption capacity and the blood absorption rate of the super absorbent resin of the present invention.

[0064] Human blood was purchased from hospital, and its blood absorption capacity and blood absorption rate were tested according to the test method described in ISO 19699-1:2017(E) (replace the blood simulant solution in the test method described in ISO 19699-1:2017(E) with human blood for testing), the specific method is as follows.

[0065] The blood simulant solution is prepared according to the preparation method described in ISO 19699-1:2017(E), and the test method is according to the test method of the blood absorption capacity and blood absorption rate described in ISO 19699-1:2017(E). The specific method is as follows.

[0066] Physical Properties of Human Blood:

[0067] After testing, the corresponding parameters of human blood used in the present invention are as follows:

TABLE-US-00001 Property Value Standard Density (1.04-1.05) g/ml GB/T 22230-2008 ISO 758 Viscosity (3.2-4.4) mP .Math. s GB/T 5561-2012 ISO 6388 pH value 6.35-7.35 GB/T9742-2007 ISO 6353-1

[0068] Preparation Method of Blood Simulant Solution:

[0069] A.1 Principle

[0070] The blood simulant solution is formulated according to the main physical properties of human blood, which has similar flow and viscosity characteristics, and can well simulate the performance of human blood.

[0071] A.2 Formula

[0072] Unless otherwise specified, the following reagents can only be used with reagents marked as chemically pure. The chemical composition of the blood simulant solution includes the following substances:

TABLE-US-00002 Deionized water (three grade 860.000 g ± 1.000 g water specified in ISO3696): Sodium chloride:  10.000 g ± 0.010 g Sodium carbonate:  40.000 g ± 0.040 g Glycerol (glycerin): 140.0 ml Sodium benzoate:    1000 g ± 0.001 g Blue pigment: 0.050 ml Sodium carboxymethyl cellulose   5.000 g ± 0.005 g (molecular weight 25000): Standard modifier (non-ionic 10.0 ml polymeric fluorine-containing surfactant):

[0073] A.3 Physical Properties of Blood Simulant Solution

[0074] At (23±1)° C., the blood simulant solution will meet the requirements in the following table:

TABLE-US-00003 Property Value Standard Density (1.05 ± 0.05) g/ml GB/T 22230-2008 ISO 758 Viscosity (7.3 ± 1.1) mPa .Math. s GB/T 5561-2012 ISO 6388 Surface Tension (40 ± 4) mN/m GB/T 22237-2008 EN 14370 pH value 11.0 ± 0.1 GB/T9742-2007 ISO 6353-1

[0075] A.4 Preparation Method

[0076] A.4.1 Weigh 10.00 g sodium chloride, 40.00 g sodium carbonate, 1.00 g sodium benzoate, 5.00 g sodium carboxymethylcellulose with an analytical balance, and pour them into a 2000 mL beaker in turn;

[0077] A.4.2 Use a 250 ml graduated cylinder to measure 140.00 ml glycerol and pour it into the beaker in A.4.1, and use an analytical balance to weigh 860 g deionized water into the beaker, and stir evenly.

[0078] A.4.3 Use a 500 ml graduated cylinder to measure 300 ml of the mixture in A.4.2 each time, pour it into the mixer, turn on the switch and start timing with a stopwatch, stir for 7 minutes, turn off the switch, pour out the mixture, and stir the remaining mixture in this way.

[0079] A.4.4 The mixed liquid after stirring in A.4.3 is stirred once again with a stirrer according to the method in A.4.3, and then 10.0 ml standard vehicle and 0.05 ml blue pigment are added to the stirred liquid, and the mixture is evenly stirred and left for 24 hours before use.

[0080] Method for Measuring the Absorption of Blood Simulant Solution:

[0081] B.1 General Principles

[0082] In the blood simulant solution, the amount of liquid absorbed by the super absorbent resin for absorbing blood in a certain period of time is measured by the weighing method.

[0083] B.2 Reagent

[0084] B.2.1 Blood simulant solution

[0085] The blood simulant solution should be prepared as described above.

[0086] B.3 Equipment

[0087] B.3.1 Analytical balance: the range is 100 g, and the sensitivity is 0.0001 g.

[0088] B.3.2 Nylon tea bag: The size is 100 mm×150 mm, the bag is made of nylon filter cloth with a pore size of 300 mesh, and the basis weight is 58 g/m.sup.2.

[0089] B.3.3 Glass beaker: 2000 ml capacity.

[0090] B.3.4 Timer: The timing range is 60 min, accurate to 0.1 s.

[0091] B.3.5 Drying rack with clamping wire and clamp.

[0092] B.3.6 Thermometer: The range is 100° C.

[0093] B.4 Sampling

[0094] To ensure that the samples taken from large bags or containers are representative, the top layer (approximately 20 cm) should be removed. A spoon is used to take 500 grams of the test sample, and it is placed in a suitable airtight container within 3 minutes after taking it.

[0095] Before the sample is tested, the sample should be placed in a closed container to reach equilibrium with the laboratory environment temperature. The recommended test conditions refer to ISO291. If the above conditions are not met, the temperature and relative humidity should be recorded.

[0096] B.5 Measurement Procedure

[0097] B.5.1 Weigh (1.000±0.005) g sample, accurate to 0.0001 g, and record the mass of the sample as m.sub.0, pour all the sample into the tea (4.8.3.2) and spread it flat on the bottom of the tea bag (the sample attached to the inside of the tea bag should also be poured into the bottom of the tea bag), and heat stitched about 3-5 cm along the edge of the opening of the tea bag.

[0098] B.5.2 Fill a glass beaker (4.8.3.3) with 1800 mL of blood simulant solution (4.8.2.1), put the tea bags into the beaker containing the blood simulant solution according to the number, so that the liquid is immersed in the tea bag and the height is 2.0 cm, and press count down with a stopwatch. (Each beaker puts at most 2 groups, that is, 4 tea bags).

[0099] B.5.3 After 30 minutes, take out the tea bags in sequence according to their numbers, fold the upper left corner of the tea bags down for about ½, and hang them on the drying rack with a clip, and hang them at an angle of about 45°.

[0100] B.5.4 After hanging for 10 minutes, take down the weighing mass in the order of hanging and mark it as m.sub.1. When multiple samples are tested at the same time, they cannot touch each other.

[0101] B.5.5 According to the above method, the blank value of the teabag used above is measured without placing the sample, and the mass of the blank teabag after absorbing the liquid is recorded as m.sub.2.

[0102] B.6 Display of Measurement Results

[0103] The absorption capacity of the blood simulant solution can be calculated according to formula (4):

[00001]$\begin{array}{cc}m=\frac{m_1-m_2-m_0}{m_0}& \left(4\right)\end{array}$

[0104] wherein:

[0105] m—The amount of blood simulant solution absorbed by the sample, in grams per gram (g/g);

[0106] m.sub.1—The mass of the tea bag containing the sample after absorbing the liquid, in grams (g); [0107] m.sub.2—The mass of the blank test teabag, in grams (g); [0108] m.sub.0—The mass of the sample to be weighed, in grams (g);

[0109] Perform two measurements at the same time, and take the arithmetic mean value as the measurement result, and the result should be rounded to one decimal place.

[0110] Method for measuring absorption rate of blood simulant solution:

[0111] C.1 General Principles

[0112] In the blood simulant solution, the rate of absorption of the blood simulant solution was measured by the liquid no-flow method, and the time required for 1 g of sodium polyacrylate resin to absorb 5.0 ml of the blood simulant fluid.

[0113] C.2 Reagent

[0114] C.2.1 Blood simulant solution should be prepared as described above.

[0115] C.3 Equipment

[0116] C.3.1 Analytical balance: the range is 100 g and the accuracy is 0.0001 g.

[0117] C.3.2 Glass beaker: 100 mL capacity.

[0118] C.3.3 Glass measuring cylinder, type A or B (laboratory glass products) with a capacity of 5.0 mL (accurate to 0.1 ml).

[0119] C.3.4 Timer. The timing range is 60 min, accurate to 0.1 s.

[0120] C.4 Sampling

[0121] Appropriate protective equipment should be used when handling samples over 10 g, such as a dust mask or a fume hood.

[0122] To ensure that the samples taken from large bags or containers are representative, the top layer (approximately 20 cm) should be removed. Use a spoon to take 1,000 grams of the test sample, and place it in a suitable airtight container within 3 minutes after taking it.

[0123] Before the sample is tested, the sample should be placed in a closed container to reach equilibrium with the laboratory environment temperature. The recommended test condition temperature is (23±1)° C. and relative humidity is (50±10)% (ISO 291, class II).

[0124] C.5 Test Steps

[0125] Perform at least two tests according to the following procedure:

[0126] C.5.1 Use an analytical balance (C.3.1) to weigh (1.000±0.005) g of the sample to be tested, accurate to 0.001 g, and pour it into a beaker (C.3.2).

[0127] C.5.2 Shake or tap the beaker by hand to spread the sample evenly on the bottom of the beaker.

[0128] C.5.3 Use a graduated cylinder (C.3.3) to measure 5.0 mL of blood simulant solution (C.2.1) at (23±1)° C. Pour into the center of the bottom (C.5.2) (control the speed so that the liquid does not splash on the inner wall of the beaker when pouring) and start timing at the same time.

[0129] C.5.4 When the fluidity of the liquid in the cup disappears, stop the stopwatch and record the elapsed time t.

[0130] One way to determine complete absorption is to tilt the beaker slightly and observe whether there is liquid flow.

[0131] C.6 Presentation of the Results

[0132] Calculate the arithmetic average based on the measured value of the simulated blood absorption rate, and round it to an integer, expressed in seconds.

[0133] The absorption rate of blood simulant solution is calculated by the time it takes to absorb 5.0 ml of blood simulant solution with 1 g SAP.

[0134] The gel strength was tested according to the method described in the literature reported by Zhu Youliang et al. (Zhu Youliang, Wu Guoqiang, Synthesis of water absorption resin with core-shell structure, Plastics, 2005, 34(1):23-26 (, , , , ,2005, 34(1):23-26)). The test results are shown in Table 1.

TABLE-US-00004 TABLE 1 Resin performance test results Absorption Absorption capacity of rate of Absorption Absorption blood blood capacity rate of simulant simulant Gel of human human Gel solution(g/g) solution (s) strength blood (g/g) blood (s) strength Example 1 18.6 37 excellent 8.0 27 excellent Example 2 19.0 36 excellent 8.5 23 excellent Example 3 18.8 37 excellent 8.3 25 excellent Example 4 18.5 38 excellent 8.6 30 excellent Example 5 18.7 37 excellent 8.5 32 excellent Example 6 18.7 37 excellent 8.7 33 excellent Example 7 18.3 39 excellent 8.3 32 excellent Example 8 18.6 39 excellent 8.6 36 excellent Example 9 18.3 44 excellent 8.3 40 excellent Example 10 18.1 45 excellent 8.7 45 excellent Example 11 18.1 45 excellent 8.6 45 excellent Example 12 18.2 44 excellent 8.2 43 excellent Example 13 18.4 42 excellent 8.4 42 excellent Example 14 18.0 41 excellent 8.0 41 excellent Example 15 18.4 43 excellent 8.4 43 excellent Example 16 18.2 42 excellent 8.2 42 excellent Comparative 4.3 110 excellent 2.3 220 excellent example 1

[0135] It can be clearly seen from the data listed in Table 1 that the super absorbent resin of the present invention has excellent absorption performance and gel strength regardless of whether the detection medium is a blood simulation solution or real human blood for testing. Among them, the amount of blood absorption is significantly higher than that of the comparative example, and the blood absorption rate is much faster than that of the comparative example.

[0136] 2 Residual Monomer

[0137] According to GB/T20405.2-2006, the monomer residual amount of the super absorbent resin in examples 1-8 of the present invention (calculated as acrylic acid) is ≤800 mg/kg; the residual monomer of the super absorbent resin in examples 9-16 of the present invention (calculated as acrylic acid) is ≤1000 mg/kg.

[0138] 3 Volatile Content

[0139] According to GB/T20405.4-2006, the volatile of the super absorbent resin in Examples 1-16 of the present invention is ≤10.0%.

[0140] 4 pH Value

[0141] According to GB/T20405.1-2006, the pH value of the super absorbent resins of Examples 1-16 of the present invention is ≥5.0 and ≤8.0.

[0142] 5 Particle Size Distribution

[0143] The test method is as follows:

[0144] 5.1 General principles

[0145] Through a series of standard sieves, the quantitative super absorbent resin is divided into several specific particle size components. Weigh each component and report it as a percentage of the total.

[0146] 5.2 Equipment

[0147] 5.2.1 Analytical balance: 1000 g range, 0.01 g accuracy.

[0148] 5.2.2 Beaker: made of glass or plastic, with a capacity of 250 mL

[0149] 5.2.3 Vibrating screen machine: Retsch VE1000 and equivalent types. It can be loaded with 3 standard sieves with a diameter of 200 mm, with bottom collecting pan and upper cover, grounded to prevent static electricity.

[0150] 5.2.4 Standard sieve: a stainless steel sieve with a diameter of φ200 mm, with apertures of 45 μm, 106 μm, 150 μm, with a bottom collecting pan and upper cover.

[0151] 5.2.5 Brush: made of camel hair. Used to clean standard sieve.

[0152] 5.2.6 Stopwatch: measuring range 60 min, accurate to 0.1 s.

[0153] 5.3 Sampling

[0154] Warning: Use appropriate protective equipment, such as dust mask or fume hood, when handling samples over 10 g.

[0155] In order to ensure that the samples taken from large bags or containers are representative, the uppermost layer (approximately 20 cm) should be removed. Use a spoon to sample and place it in a suitable closed container within 3 minutes after sampling.

[0156] Before the sample is tested, the sample should be placed in a closed container to reach equilibrium with the laboratory environment temperature. The recommended test conditions are: (23±2)° C., relative humidity (50±10)%. If the above conditions are not met, the temperature and relative temperature should be recorded.

[0157] Before taking the sample out of the container for testing, shake the container 3 to 5 times to ensure that the sample is even, then leave it for 5 minutes, open the lid and take out the sample.

[0158] 5.4 Steps

[0159] 5.4.1 Make sure the sieve is dry. Lightly inspect each sieve for damage and cleanliness. The sieve should be replaced if damaged. Use a brush to remove residual particles on the sieve.

[0160] 5.4.2 Place the bottom plate and the sieve on a standard vibrating machine in the order of bottom plate, 45 μm, 106 μm, and 150 μm from bottom to top.

[0161] 5.4.3 Weigh (100±0.01) g of the super absorbent resin sample, record it as m, and put it into a beaker.

[0162] 5.4.4 Pour all the samples in the 5.4.3 beaker into the top sieve.

[0163] 5.4.5 Cover the upper cover and seal it according to the standard vibrating screen machine instructions.

[0164] 5.4.6 Ensure that the equipment is grounded to prevent static electricity.

[0165] 5.4.7 Set up the vibrating screen machine according to the following conditions: [0166] Strength: (70±2)% (set for Retsch VE1000). [0167] Amplitude: 1.0 mm [0168] Oscillation time: 10 min.

[0169] 5.4.8 Start the vibrating screen machine. After shaking for 10 minutes, weigh the mass of the sample remaining on the 106 μm sieve as m.sub.1, the mass of the sample remaining on the 45 μm sieve as m.sub.2, and the mass of the sample remaining on the bottom plate as m.sub.3.

[0170] 5.5 Calculation

[0171] The percentage of each part is calculated according to the following formula:

Sample content below the 150 μm screen: X.sub.1=[(m.sub.1+m.sub.2+m.sub.3)/m.sub.s]*100%

Sample content below the 106 μm screen: X.sub.2=[(m.sub.2+m.sub.3)/m.sub.s]*100%

Sample content below the 45 μm screen: X.sub.3=[m.sub.3/m.sub.s]*100%

[0172] wherein:

[0173] X.sub.1—The content of the sample below the 150 μm screen, expressed in %;

[0174] m.sub.1—The mass of the sample remaining on the 106 μm sieve, expressed in g;

[0175] m.sub.2—The mass of the sample remaining on the 45 μm sieve, expressed in g;

[0176] m.sub.3—The mass of the sample remaining on the chassis, expressed in g;

[0177] m.sub.s—The total mass of the sample, expressed in g;

[0178] X.sub.2—The content of the sample below the 106 μm screen, expressed in %;

[0179] X.sub.3—The content of the sample below the 45 μm screen, expressed in %;

[0180] Perform two measurements at the same time, and take the arithmetic mean value as the measurement result, and round the result to one decimal place.

[0181] After measurement, the particle size distribution of the super absorbent resins of Examples 1-16 of the present invention is ≤5% (the content of samples with a particle diameter of <150 μm), and ≤1% (the content of samples with a particle diameter of <106 μm).

[0182] 6 Bulk Density

[0183] According to ISO17190-9, the bulk density of the super absorbent resin in Examples 1-16 of the present invention is ≥0.65 g/cm.sup.3 and ≤0.80 g/cm.sup.3.

[0184] 7 Whiteness

[0185] According to GB/T22427.6-2008, the whiteness of the super absorbent resins of Examples 1-16 of the present invention is ≥70%.

[0186] Obviously, the above-mentioned embodiments are merely examples for clear description, and are not intended to limit the implementation. For those of ordinary skill in the art, other modifications or changes in different forms can be made on the basis of the above description. There is no need and cannot give an exhaustive list of all implementation methods. The obvious changes or modifications derived from this are still within the protection scope of the present invention.