A sanitary napkin structure and preparation method thereof

Abstract

A sanitary napkin structure comprises a water-repellent layer, an absorbent core and a fabric layer from bottom to top, wherein the absorbent core structure is a film structure provided with permeable holes; the raw material emulsion of the film structure comprises the following components: a star-shaped modified acrylic resin, acrylate, a cross-linking agent, a photoinitiator, an initiator, an auxiliary agent, and a solvent; wherein the raw materials of the star-shaped modified acrylic resin comprise: a star-shaped acrylic monomer, acrylate, acrylamide, a cross-linking agent, an initiator, an auxiliary agent, a solvent, and silica particles 1 modified by acrylic acid and modified silica particles 2. The absorbent core of the sanitary napkin structure provided by the present invention can keep water molecules inside the star-shaped acrylic copolymer, prevent the loss of water molecules, keep the sanitary napkin dry and comfortable, and has a strong water absorption capacity, a fast water absorption rate and excellent water retention performance.

Description

Technical Field

[0001] The present invention relates to the technical field of sanitary products, and in particular to a sanitary napkin structure and a preparation method thereof. Background Art

[0002] Sanitary napkins are essential products for women during menstruation. They are designed to improve women's quality of life during menstruation. After years of development and improvement, they can now meet women's needs well.

[0003] However, the absorbent core of traditional sanitary napkin products generally uses a mixture of fluff pulp and super absorbent resin as the absorbent material. This combination of absorbent materials improves the absorption performance to a certain extent, but during use, problems such as slow absorption speed, insufficient liquid absorption, and back-seepage may still occur. These problems not only affect the use effect of sanitary napkins, but may also cause certain troubles to women's physiological health.

[0004] In summary, there is an urgent need to develop a new technical solution to solve the problems existing in the existing technology and meet the development needs of the current market. Summary of the invention

[0005] Based on this, the present invention provides a sanitary napkin structure and a preparation method thereof. The absorbent core of the sanitary napkin structure provided by the present invention is prepared from a mixed emulsion of components such as a star-shaped modified acrylic resin, an acrylic ester, and a cross-linking agent, wherein the modified acrylic resin is prepared from components such as a star-shaped acrylic monomer, acrylic acid-modified silica particles 1 and modified silica particles 2, and has strong water absorption capacity, a relatively fast water absorption rate, and excellent water retention performance.

[0006] One object of the present invention is to provide a sanitary napkin structure, which comprises, from bottom to top, a water-repellent layer, an absorbent core and a fabric layer, wherein the absorbent core structure is:

[0007] A membrane structure provided with permeable holes;

[0008] The raw material emulsion of the film structure comprises the following components:

[0009] Star-shaped modified acrylic resin, acrylate, crosslinking agent, photoinitiator, initiator, auxiliary agent, solvent;

[0010] Wherein, the raw materials of the star-shaped modified acrylic resin include:

[0011] A star-shaped acrylic acid monomer, acrylic acid salt, acrylamide, a crosslinking agent, an initiator, an auxiliary agent, a solvent, and acrylic acid-modified silica particles 1 and modified silica particles 2;

[0012] The modified silica particles 1 are hydroxylated silica, partially grafted with acrylic acid and partially grafted with oleic acid;

[0013] The modified silicon dioxide particles 2 are the product of hydroxylated silicon dioxide, which is partially grafted with acrylic acid and partially grafted with alkyl acid.

[0014] Furthermore, the mass ratio of the star-shaped acrylic acid monomer, acrylic acid salt, acrylamide, crosslinking agent, initiator, auxiliary agent, solvent, modified silica particles 1 and modified silica particles 2 is (20-40):(5-15):(5-15):(1-5):(0.1-2):(1-5):(40-100):(5-10):(5-10).

[0015] Furthermore, the pore size of the permeable pore is 60-130 μm.

[0016] Furthermore, the star-shaped acrylic monomer is trimethylolpropane trimethacrylate.

[0017] Furthermore, the cross-linking agent is N,N-methylenebisacrylamide.

[0018] Furthermore, the photoinitiator is 2-hydroxy-2-methyl-1-phenyl-1-propanone.

[0019] Furthermore, the initiator is selected from one or more of ammonium persulfate, sodium persulfate, potassium persulfate, and azo initiators.

[0020] Furthermore, the auxiliary agent is selected from one or more of an emulsifier, a surfactant, a leveling agent, a accelerator or a film-forming auxiliary agent.

[0021] Furthermore, in the modified silica particles 1, the ratio of acrylate to oleic acid is 1:0.1-0.3.

[0022] Furthermore, in the modified silica particles 2, the ratio of acrylate to alkyl acid is 1:1-3.

[0023] Another object of the present invention is to provide a method for preparing the above-mentioned sanitary napkin structure, including a method for preparing an absorbent core, wherein the method for preparing the absorbent core comprises the following steps:

[0024] S1, adding silicon dioxide to strong acid and hydrogen peroxide for treatment to obtain hydroxylated silicon dioxide 1; blending the hydroxylated silicon dioxide 1 with acrylic acid and oleic acid, and performing ultrasonic heating reaction to obtain modified silicon dioxide particles 1;

[0025] S2, adding silicon dioxide to a strong acid and hydrogen peroxide for hydroxylation treatment to obtain hydroxylated silicon dioxide 2; blending the hydroxylated silicon dioxide 2 with acrylic acid and an alkyl acid, and subjecting the mixture to ultrasonic heating reaction to obtain modified silicon dioxide particles 2;

[0026] S3, blending the star-shaped acrylic acid monomer, acrylic acid salt, acrylamide, crosslinking agent, initiator, auxiliary agent, solvent, modified silica particles 1 and modified silica particles 2, heating and reacting under an inert gas atmosphere, and purifying to obtain a star-shaped modified acrylic resin;

[0027] S4, blending the star-shaped modified acrylic resin, acrylate, crosslinking agent, photoinitiator, initiator, auxiliary agent, and solvent to obtain an emulsion;

[0028] S5. Apply the emulsion on the surface of the fabric, react under light conditions, and then treat with steam, dehydrate and dry to obtain the absorbent core.

[0029] Furthermore, in step S1, the temperature of the heating reaction is 60-80°C; and the time of the heating reaction is 8-12h.

[0030] Furthermore, in step S2, the temperature of the heating reaction is 60-80°C; and the time of the heating reaction is 8-12h.

[0031] Furthermore, in step S3, the heating temperature is 60-100°C.

[0032] Furthermore, in step S5, the thickness of the emulsion coating is 0.5-2 mm.

[0033] The present invention has the following beneficial effects:

[0034] The absorbent core of the sanitary napkin structure provided by the present invention is prepared from a mixed emulsion of star-shaped modified acrylic resin, acrylic ester, crosslinking agent and other components, wherein the modified acrylic resin is prepared from star-shaped acrylic monomer, silica particles 1 modified by acrylic acid and fatty acid, and modified silica particles 2 and other components. The present invention firstly performs hydroxylation treatment on silica to enhance the activity of its surface groups, and then reacts with acrylic acid and oleic acid to obtain modified silica particles 1 with unsaturated double bond structures introduced on the surface, and uses the same treatment method to obtain modified silica particles 2 with unsaturated double bonds and alkyl chains introduced; then, the star-shaped acrylic monomer is used as the core structure, and copolymerized with acrylate, acrylamide and modified silica particles 1 and 2 to obtain a star-shaped modified acrylic resin. The star-shaped modified acrylic resin has a strong water absorption capacity and a fast water absorption rate. On the one hand, its molecules contain abundant hydrophilic groups such as ester groups and amide groups, which can form hydrogen bonds with water molecules, thereby attracting and fixing a large number of water molecules, and can quickly absorb a large amount of menstrual blood; on the other hand, the star-shaped structure of its molecules can increase the contact area between the polymer and the water molecules, accelerate the adsorption and diffusion process of the water molecules, so that the sanitary napkin can quickly absorb the menstrual blood after contacting it, and reduce the possibility of blood accumulation on the surface of the absorption core or overflow. In addition, the star-shaped modified acrylic resin is copolymerized so that the modified silica particles 1 and 2 are uniformly dispersed in the star-shaped acrylic matrix, as spatial cross-linking sites, to form a stable network structure, so that the star-shaped acrylic ester copolymer has an ultra-high specific surface area, thereby improving its water absorption rate; at the same time, the stable network structure can extend the path for water molecules to diffuse from the inside of the resin to the outside, thereby keeping the water molecules inside the star-shaped acrylic ester copolymer, preventing the loss of water molecules, and keeping the sanitary napkin dry and comfortable. DETAILED DESCRIPTION

[0035] In order to more clearly illustrate the technical solution of the present invention, the following examples are listed. Unless otherwise stated, the raw materials, reactions and post-treatment methods shown in the examples are common raw materials on the market and technical methods well known to those skilled in the art.

[0036] The words "preferred", "preferably", "more preferably", etc. in the present invention refer to embodiments of the present invention that can provide certain beneficial effects in certain circumstances. However, other embodiments may also be preferred under the same circumstances or other circumstances. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not applicable, nor is it intended to exclude other embodiments from the scope of the present invention.

[0037] It should be understood that, except in any operating examples, or where otherwise indicated, all numbers indicating, for example, the amounts of ingredients used in the specification and claims should be understood to be modified in all cases by the term "about". Therefore, unless indicated to the contrary, the numerical parameters set forth in the following specification and the appended claims are approximate values ​​that vary depending on the desired properties to be obtained by the present invention.

[0038] The azobisisobutylamidine hydrochloride in the examples and comparative examples of the present invention is V50, produced by Hubei Shixing Chemical.

[0039] The "parts" in the embodiments of the present invention refer to parts by mass.

[0040] Example 1

[0041] A sanitary napkin structure comprises, from bottom to top, a water-repellent layer, an absorbent core and a fabric layer, wherein the absorbent core structure is:

[0042] A thin film structure having permeable pores with a pore size of 60-130 μm;

[0043] The raw material emulsion of the film structure comprises the following components:

[0044] 10 parts of star-shaped modified acrylic resin, 50 parts of isobutyl acrylate, 15 parts of N,N-methylenebisacrylamide, 1 part of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1 part of azobisisobutylamidine hydrochloride, 5 parts of dioctadecyldimethylammonium bromide, and 200 parts of deionized water;

[0045] The raw materials of the star-shaped modified acrylic resin include:

[0046] 30 parts of trimethylolpropane trimethacrylate, 10 parts of sodium acrylate, 8 parts of acrylamide, 1 part of N,N-methylenebisacrylamide, 1 part of azobisisobutylamidine hydrochloride, 2 parts of dioctadecyldimethylammonium bromide, 80 parts of deionized water, and 1 8 parts of silica particles modified with acrylic acid and 2 8 parts of modified silica particles;

[0047] The modified silica particles 1 are hydroxylated silica, partially grafted with acrylic acid and partially grafted with oleic acid;

[0048] The modified silicon dioxide particles 2 are the product of hydroxylated silicon dioxide, which is partially grafted with acrylic acid and partially grafted with lauric acid.

[0049] The preparation method of the above absorbent core comprises the following steps:

[0050] S1, adding silicon dioxide to a mixed solution of concentrated sulfuric acid and hydrogen peroxide (the mass ratio of concentrated sulfuric acid to hydrogen peroxide is m:m=7:3, and the concentration of the hydrogen peroxide is 30%), reacting at 80°C for 1 hour, washing and removing unreacted concentrated sulfuric acid and hydrogen peroxide to obtain hydroxylated silicon dioxide 1; using ethanol as a solvent, blending the hydroxylated silicon dioxide 1, acrylic acid and oleic acid, reacting under ultrasonic conditions at 70°C for 10 hours, and then filtering, washing and drying to obtain modified silicon dioxide particles 1;

[0051] Wherein, the mass ratio of silicon dioxide, acrylic acid and oleic acid is m:m:m=1:5:1;

[0052] S2, adding silica to a mixed solution of concentrated sulfuric acid and hydrogen peroxide (the mass ratio of concentrated sulfuric acid to hydrogen peroxide is m:m=7:3, and the concentration of the hydrogen peroxide is 30%), reacting at 80°C for 1 hour, washing and removing unreacted concentrated sulfuric acid and hydrogen peroxide to obtain hydroxylated silica 2; using ethanol as a solvent, blending the hydroxylated silica 2, acrylic acid and lauric acid, reacting under ultrasonic conditions at 70°C for 10 hours, and then filtering, washing and drying to obtain modified silica particles 2;

[0053] Wherein, the mass ratio of silicon dioxide, acrylic acid and lauric acid is m:m:m=1:5:5;

[0054] S3, according to the above mass parts, trimethylolpropane trimethacrylate, sodium acrylate, acrylamide, N,N-methylenebisacrylamide, azobisisobutylamidine hydrochloride, dioctadecyldimethylammonium bromide, deionized water, and acrylic acid-modified silica particles 1 and modified silica particles 2 are mixed, reacted under a nitrogen atmosphere at 70° C. for 2 h, filtered, washed, and dried to obtain a star-shaped modified acrylic resin;

[0055] S4, blending the star-shaped modified acrylic resin, isobutyl acrylate, N,N-methylenebisacrylamide, 2-hydroxy-2-methyl-1-phenyl-1-propanone, azobisisobutylamidine hydrochloride, dioctadecyldimethylammonium bromide and deionized water to obtain an emulsion;

[0056] S5, the emulsion is applied to the upper and lower surfaces of the non-woven fabric, the thickness is 1.5 mm, and then the wavelength is 450 nm and the intensity is 50 mW / cm 2 The absorbent core is irradiated with light for 120 seconds, and then placed in a steam tunnel oven for curing for 5 minutes. After dehydration, drying and cutting, the absorbent core is obtained.

[0057] Example 2

[0058] A sanitary napkin structure comprises, from bottom to top, a water-repellent layer, an absorbent core and a fabric layer, wherein the absorbent core structure is:

[0059] A thin film structure having permeable pores with a pore size of 60-130 μm;

[0060] The raw material emulsion of the film structure comprises the following components:

[0061] 10 parts of star-shaped modified acrylic resin, 55 parts of isobutyl acrylate, 16 parts of N,N-methylenebisacrylamide, 1 part of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1 part of azobisisobutylamidine hydrochloride, 5 parts of dioctadecyldimethylammonium bromide, and 250 parts of deionized water;

[0062] The raw materials of the star-shaped modified acrylic resin include:

[0063] 25 parts of trimethylolpropane trimethacrylate, 8 parts of sodium acrylate, 7 parts of acrylamide, 1 part of N,N-methylenebisacrylamide, 1 part of azobisisobutylamidine hydrochloride, 2 parts of dioctadecyldimethylammonium bromide, 70 parts of deionized water, and 1 6 parts of silica particles modified with acrylic acid and 2 7 parts of modified silica particles;

[0064] The modified silica particles 1 are hydroxylated silica, partially grafted with acrylic acid and partially grafted with oleic acid;

[0065] The modified silicon dioxide particles 2 are the product of hydroxylated silicon dioxide, which is partially grafted with acrylic acid and partially grafted with lauric acid.

[0066] The preparation method of the above absorbent core is the same as that of Example 1.

[0067] Example 3

[0068] A sanitary napkin structure comprises, from bottom to top, a water-repellent layer, an absorbent core and a fabric layer, wherein the absorbent core structure is:

[0069] A thin film structure having permeable pores with a pore size of 60-130 μm;

[0070] The raw material emulsion of the film structure comprises the following components:

[0071] 12 parts of star-shaped modified acrylic resin, 60 parts of isobutyl acrylate, 20 parts of N,N-methylenebisacrylamide, 1 part of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1 part of azobisisobutylamidine hydrochloride, 5 parts of dioctadecyldimethylammonium bromide, and 250 parts of deionized water;

[0072] The raw materials of the star-shaped modified acrylic resin include:

[0073] 35 parts of trimethylolpropane trimethacrylate, 12 parts of sodium acrylate, 10 parts of acrylamide, 1 part of N,N-methylenebisacrylamide, 1 part of azobisisobutylamidine hydrochloride, 2 parts of dioctadecyldimethylammonium bromide, 90 parts of deionized water, and 10 parts of acrylic acid-modified silica particles 1 and 9 parts of modified silica particles 2;

[0074] The modified silica particles 1 are hydroxylated silica, partially grafted with acrylic acid and partially grafted with oleic acid;

[0075] The modified silicon dioxide particles 2 are the product of hydroxylated silicon dioxide, which is partially grafted with acrylic acid and partially grafted with lauric acid.

[0076] The preparation method of the above absorbent core is the same as that of Example 1.

[0077] Comparative Example 1

[0078] A sanitary napkin structure. The difference between this comparative example and Example 1 is that in the preparation method of the absorbent core, the modified silica particles 1 are replaced by unmodified silica, and the other components and preparation method are the same as those in Example 1.

[0079] Comparative Example 2

[0080] A sanitary napkin structure. The difference between this comparative example and Example 1 is that in the preparation method of the absorbent core, trimethylolpropane trimethacrylate is replaced by isobutyl acrylate, and the other ingredients and preparation method are the same as those in Example 1.

[0081] Test Case

[0082] A performance comparison test was performed on Examples 1-3 and Comparative Examples 1-2.

[0083] Test method: GB / T14207-2008 is used to test water absorption and blood absorption.

[0084] The test results are shown in Table 1.

[0085] Table 1 Absorption performance test results

[0086] project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Artificial menstrual blood penetration time (s) 5.65 5.58 5.62 6.53 9.57 Artificial menstrual blood backflow volume (g) 0.51 0.48 0.49 1.56 2.89 Water absorption (g) 52.2 53.4 52.6 48.3 45.6

[0087] According to Table 1, it can be concluded that the absorbent core prepared by the mixed emulsion of modified acrylic resin, acrylate, crosslinking agent and other components in the embodiment of the present invention has excellent liquid absorption capacity, and its penetration time, re-infiltration amount, water absorption amount and other data are significantly better than those of Comparative Examples 1-2. However, since Comparative Example 1 uses unmodified silica to replace the modified silica particles 1 component, it is difficult for the prepared star-shaped acrylate copolymer to form a more three-dimensional and dense microporous structure, and the specific surface area is relatively low, so the absorption capacity of the prepared absorbent core is significantly reduced, the water retention performance is not ideal, and the artificial menstrual blood re-infiltration amount is large; Comparative Example 2 uses isobutyl acrylate to replace trimethylolpropane trimethacrylate. After modification, the hydrophilic groups in its molecules are less, the absorption capacity of water molecules is weak, and it does not have a star-shaped structure, and the contact area between it and water molecules is small, so the performance of the prepared absorbent core product is greatly reduced.

[0088] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0089] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A sanitary napkin structure, comprising, from bottom to top, a water-repellent layer, an absorbent core and a fabric layer, characterized in that: The absorbent core structure is: A membrane structure provided with permeable holes; The raw material emulsion of the film structure comprises the following components: Star-shaped modified acrylic resin, acrylate, crosslinking agent, photoinitiator, initiator, auxiliary agent, solvent; Wherein, the raw materials of the star-shaped modified acrylic resin include: A star-shaped acrylic acid monomer, acrylic acid salt, acrylamide, a crosslinking agent, an initiator, an auxiliary agent, a solvent, and acrylic acid-modified silica particles 1 and modified silica particles 2; The modified silica particles 1 are hydroxylated silica, partially grafted with acrylic acid and partially grafted with oleic acid; The modified silica particles 2 are hydroxylated silica, which is partially grafted with acrylic acid and partially grafted with alkyl acid; The star-shaped acrylic monomer is trimethylolpropane trimethacrylate.

2. The sanitary napkin structure according to claim 1, characterized in that: The mass ratio of the star-shaped acrylic acid monomer, acrylic acid salt, acrylamide, crosslinking agent, initiator, auxiliary agent, solvent, modified silica particles 1 and modified silica particles 2 is (20-40):(5-15):(5-15):(1-5):(0.1-2):(1-5):(40-100):(5-10):(5-10).

3. The sanitary napkin structure according to claim 1, characterized in that: The pore size of the permeable pore is 60-130 μm.

4. The sanitary napkin structure according to claim 1, characterized in that: In the modified silica particles 1, the mass ratio of acrylic acid to oleic acid is 1:0.1-0.

3.

5. The sanitary napkin structure according to claim 1, characterized in that: In the modified silica particles 2, the mass ratio of acrylic acid to alkyl acid is 1:1-3.

6. The method for preparing the sanitary napkin structure according to any one of claims 1 to 5, characterized in that: The invention relates to a method for preparing an absorbent core, wherein the method comprises the following steps: S1, adding silicon dioxide to strong acid and hydrogen peroxide for treatment to obtain hydroxylated silicon dioxide 1; blending the hydroxylated silicon dioxide 1 with acrylic acid and oleic acid, and performing ultrasonic heating reaction to obtain modified silicon dioxide particles 1; S2, adding silicon dioxide to a strong acid and hydrogen peroxide for hydroxylation treatment to obtain hydroxylated silicon dioxide 2; blending the hydroxylated silicon dioxide 2 with acrylic acid and an alkyl acid, and subjecting the mixture to ultrasonic heating reaction to obtain modified silicon dioxide particles 2; S3, blending the star-shaped acrylic acid monomer, acrylic acid salt, acrylamide, crosslinking agent, initiator, auxiliary agent, solvent, modified silica particles 1 and modified silica particles 2, heating and reacting under an inert gas atmosphere, and purifying to obtain a star-shaped modified acrylic resin; S4, blending the star-shaped modified acrylic resin, acrylate, crosslinking agent, photoinitiator, initiator, auxiliary agent, and solvent to obtain an emulsion; S5. Apply the emulsion on the surface of the fabric, react under light conditions, and then treat with steam, dehydrate and dry to obtain the absorbent core.

7. The method for preparing the sanitary napkin structure according to claim 6, characterized in that: In step S1, the temperature of the heating reaction is 60-80°C; the time of the heating reaction is 8-12 h.

8. The method for preparing the sanitary napkin structure according to claim 6, characterized in that: In step S2, the temperature of the heating reaction is 60-80°C; the time of the heating reaction is 8-12 h.

9. The method for preparing the sanitary napkin structure according to claim 6, characterized in that: In step S3, the heating temperature is 60-100°C.