Latex sponge product and preparation method thereof

Abstract

The invention relates to the technical field of latex materials, in particular to a latex sponge product and a preparation method thereof.The latex sponge product is prepared from, by weight, 90 parts of synthetic latex; 10 parts of natural latex; 4-8 parts of a vulcanization bag dispersion; 2-5 parts of a foaming agent; 0.5-2 parts of a foam stabilizer; 0.1-5 parts of a latex stabilizer; 0-2 parts of a thickening agent; 5-30 parts of a filler; 1-5 parts of an ultraviolet absorption dispersion; the ultraviolet absorption dispersoid comprises a benzotriazole ultraviolet absorbent, a dispersing agent and water in a mass ratio of (50-55): (1-5): (45-50). The oxidation resistance and ultraviolet resistance of the latex sponge product are improved by introducing the benzotriazole ultraviolet light absorber, so that the service life of the latex sponge product is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of latex materials, in particular to a latex sponge product and a preparation method thereof. Background Art

[0002] Synthetic latex sponge products are an important type of latex product. With the continuous improvement of living standards, people are paying more and more attention to hygienic, safe, and healthy products. Latex products are becoming more and more popular due to their natural raw materials, high breathability, ultra-quietness, and high resilience. Synthetic latex sponge is a low-density porous rubber material prepared by foaming latex. It has many excellent properties such as low relative density, light weight, excellent cushioning performance, rapid recovery after deformation, and fatigue resistance. Therefore, synthetic latex sponge products can be used in many fields such as home, transportation, and construction, such as mattresses, pillows, chest pads, head pads, cushioning materials, sound insulation materials, pet cushions, etc.

[0003] However, synthetic latex sponge products are prone to yellowing, powdering, cracking, etc. during use, resulting in a shorter service life. Summary of the Invention

[0004] In order to solve the problem of short service life of synthetic latex sponge products in the prior art, the present invention provides a latex sponge product. By introducing an ultraviolet absorbing dispersion, the antioxidant and anti-ultraviolet capabilities of the latex sponge product are improved, the service life is extended, and the problem of short service life of synthetic latex sponge products in the prior art is solved.

[0005] The technical solution adopted by the present invention to solve its technical problem is: A latex sponge product, comprising the following components in parts by weight: 90 parts of synthetic latex; 10 parts of natural rubber latex; 4-8 parts of vulcanization package dispersion; 2-5 parts of foaming agent; Foam stabilizer 0.5-2 parts; 0.1-5 parts of latex stabilizer; Thickener 0-2 parts; 5-30 parts of filler; 1-5 parts of UV absorbing dispersion; The ultraviolet absorbing dispersion comprises a benzotriazole ultraviolet absorber, a dispersant and water in a mass ratio of (50-55): (1-5): (45-50).

[0006] Optionally, the benzotriazole ultraviolet absorber is an alkylated benzotriazole ultraviolet absorber.

[0007] Optionally, the alkylated benzotriazole ultraviolet absorber is prepared according to the following method: A benzotriazole compound, ethylene glycol monomethyl ether, N,N-dimethylformamide, KI, potassium carbonate, and alkyl bromide are mixed, heated to reflux, reacted, cooled to room temperature, toluene and water are added, stirred, the pH is adjusted to acidic, stirred, and crystallized to obtain an alkylated benzotriazole UV absorber.

[0008] Optionally, the usage ratio of the benzotriazole compound, the ethylene glycol monomethyl ether, the N,N-dimethylformamide, the KI, the potassium carbonate, and the bromoalkane is (2-3) g: (2-8) mL: (1-3) mL: (0.5-1.5) g: (1-2) g: (0.01-0.02) mol.

[0009] Optionally, the alkylated benzotriazole ultraviolet absorber is ultraviolet absorber microspheres obtained by encapsulation treatment.

[0010] Optionally, the ultraviolet absorber microspheres are prepared according to the following method: The alkylated benzotriazole ultraviolet absorber is mixed with a sodium alginate aqueous solution containing calcium chloride, an emulsifier is added, the temperature is raised to 35° C., and stirring is performed to obtain an emulsified suspension; the emulsified suspension is placed in a heat-insulating syringe and dropwise added to a chitosan acetic acid solution under magnetic stirring, followed by stirring, filtering, and washing with water to obtain ultraviolet absorber microspheres.

[0011] Optionally, the synthetic latex is styrene-butadiene latex, with a solid mass content of 58%-68%, a pH value of 9.2-10.5, a viscosity of 200-1500 mPa.s, and a particle size of 260-340 nm.

[0012] Optionally, the natural rubber latex has a solid mass content of 60% and an ammonia mass content of 0.2%.

[0013] Optionally, the vulcanization package dispersion includes sulfur powder, accelerator, dispersant, antioxidant and water in a mass ratio of (18-27): (18-27): (3-4): (13-15): (36-54).

[0014] Optionally, the accelerator is selected from at least one of diphenylguanidine, 2-mercaptobenzothiazole, zinc diethyldithiocarbamate, and 2-mercaptobenzothiazole zinc salt.

[0015] Optionally, the latex stabilizer is selected from at least one of potassium pyrophosphate, potassium laurate, potassium hydroxide, soybean lecithin, and casein.

[0016] Optionally, the thickener is selected from at least one of sodium carboxymethyl cellulose, gelatin, carrageenan, casein, and polypropionate.

[0017] Optionally, the filler is selected from at least one of aluminum hydroxide powder, silicate powder, and hollow glass microspheres.

[0018] Another object of the present invention is to provide a method for preparing the latex sponge product as described above, characterized in that it comprises the following steps: S1: After stirring the components in the raw materials according to the formula, a pre-dispersed latex is obtained; S2: foaming the pre-dispersed latex by a foaming device to obtain a sponge sheet; S3: vulcanizing, shaping, pressing and drying the sponge sheet to obtain a latex sponge product.

[0019] The beneficial effects of the present invention are: The latex sponge product provided by the present invention is based on the high efficiency and stability of the benzotriazole ultraviolet absorber. The benzotriazole ultraviolet absorber is introduced to improve the antioxidant and ultraviolet resistance of the latex sponge product, thereby extending the service life of the latex sponge product. Furthermore, the benzotriazole ultraviolet absorber is introduced in the form of an ultraviolet absorbing dispersion to improve the uniformity of the dispersion of the benzotriazole ultraviolet absorber in the latex sponge product, thereby further improving the anti-aging performance of the latex sponge product, improving its use value, and extending its service life. DETAILED DESCRIPTION

[0020] The present invention will now be described in further detail. The embodiments described below are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.

[0021] Synthetic latex sponge products, due to their porous, low-density properties, have a large contact area with oxygen in the air during use. Sunlight has a significant impact on these products, and these effects can easily damage their appearance and performance, impacting their value and lifespan. Synthetic latex sponge products, in particular, can yellow, powder, and crack when exposed to sunlight and oxygen. Therefore, current instructions for latex sponge products require them to be stored away from light and not washed. This significantly limits the range of their use. Furthermore, the inability to expose them to sunlight and washable water can easily lead to the growth of bacteria and mites, which is detrimental to a healthy home life.

[0022] In order to solve the problem of short service life of synthetic latex sponge products in the prior art, the present invention provides a latex sponge product, wherein the raw materials include the following components in parts by weight: 90 parts of synthetic latex; 10 parts of natural rubber latex; 4-8 parts of vulcanization package dispersion; 2-5 parts of foaming agent; Foam stabilizer 0.5-2 parts; 0.1-5 parts of latex stabilizer; Thickener 0-2 parts; 5-30 parts of filler; 1-5 parts of UV absorbing dispersion; The ultraviolet absorbing dispersion comprises a benzotriazole ultraviolet absorber, a dispersant and water in a mass ratio of (50-55): (1-5): (45-50), and preferably the dispersant in the ultraviolet absorbing dispersion is a phenol dispersion.

[0023] The latex sponge product provided by the present invention is based on the high efficiency and stability of the benzotriazole ultraviolet absorber. The benzotriazole ultraviolet absorber is introduced to improve the antioxidant and ultraviolet resistance of the latex sponge product, thereby extending the service life of the latex sponge product. Furthermore, the benzotriazole ultraviolet absorber is introduced in the form of an ultraviolet absorbing dispersion to improve the uniformity of the dispersion of the benzotriazole ultraviolet absorber in the latex sponge product, thereby further improving the anti-aging performance of the latex sponge product, improving its use value, and extending its service life.

[0024] Since the currently widely used basic benzotriazole ultraviolet absorbers have low molecular weight and high mobility, they are extremely easy to migrate and volatilize during the production process of synthetic latex sponge products and subsequent use, resulting in the physical properties and surface properties of the synthetic latex sponge products being easily deteriorated under the action of sunlight and oxygen; based on this, the present invention prefers that the benzotriazole ultraviolet absorber is an alkylated benzotriazole ultraviolet absorber.

[0025] Specifically, the present invention preferably prepares the alkylated benzotriazole ultraviolet absorber according to the following method: A benzotriazole compound, ethylene glycol monomethyl ether, N,N-dimethylformamide (DMF), KI, potassium carbonate, and alkyl bromide are mixed, heated to reflux, reacted, cooled to room temperature, toluene and water are added, stirred, the pH is adjusted to acidic, stirred, and crystallized to obtain an alkylated benzotriazole UV absorber.

[0026] In the present invention, the preferred brominated alkyl is at least one selected from octane bromide, dodecane bromide, tetradecane bromide, hexadecane bromide, and octadecane bromide.

[0027] Furthermore, in the present invention, the preferred usage ratio of the benzotriazole compound, ethylene glycol monomethyl ether, N,N-dimethylformamide (DMF), KI, potassium carbonate, and bromoalkane is (2-3) g: (2-8) mL: (1-3) mL: (0.5-1.5) g: (1-2) g: (0.01-0.02) mol.

[0028] Compared to their unalkylated counterparts, alkylated benzotriazole UV absorbers have a relatively high molecular weight, reducing volatility and migration, improving heat resistance, and exhibiting a "permanent" photostability effect, further extending the lifespan of synthetic latex sponge materials. Their molar extinction coefficient is 1.55-1.68 times that of the original material, allowing them to achieve excellent UV absorption with minimal addition. Furthermore, these alkylated benzotriazole UV absorbers possess highly reactive unsaturated bonds, such as C=C, C=O, and C=N, which facilitate the bonding of UV-absorbing functional groups to the polymer chain. This makes these functional groups resistant to volatility, migration, and extraction. Furthermore, the electron cloud of these unsaturated bonds is highly mobile, readily absorbing UV energy and undergoing electron transitions, thereby exerting their UV absorption properties. This ensures that the resulting synthetic latex sponge products possess excellent UV resistance, heat resistance, water resistance, and weather resistance.

[0029] During the preparation of latex sponge products, alkylated benzotriazole UV absorbers, due to their conjugated double bonds, affect the chemical stability of the synthetic latex, causing some latex agglomeration and demulsification, and increasing the viscosity of the synthetic latex. Furthermore, due to the structural characteristics of their conjugated system, these substances pose certain hazards to the human body. If these substances are directly added to latex, the resulting synthetic latex sponge products are susceptible to phototoxicity and photosensitivity reactions upon contact with human skin. Therefore, the present invention further prefers that the alkylated benzotriazole UV absorber be encapsulated in the form of UV absorber microspheres. This not only improves the stability and smoothness of the latex sponge production process, but also further enhances the sustained-release properties of the UV absorber, thereby extending its service life while improving safety.

[0030] Specifically, the present invention preferably prepares the ultraviolet absorber microspheres according to the following method: An alkylated benzotriazole ultraviolet absorber is mixed with a sodium alginate aqueous solution containing calcium chloride, an emulsifier is added, the temperature is raised to 35°C, and stirring is performed to obtain an emulsified suspension; the emulsified suspension is placed in a heat-insulating syringe and added dropwise to a chitosan acetic acid solution under magnetic stirring, followed by stirring, filtering, and washing with water to obtain ultraviolet absorber microspheres.

[0031] During the preparation process, sodium alginate first forms a three-dimensional gel network structure under the action of calcium ions, and at the same time, the alkylated benzotriazole ultraviolet absorber is wrapped in the formed three-dimensional gel network structure to form a physical load; then, under the action of an emulsifier, an emulsified suspension is formed; due to the addition of the emulsifier, on the one hand, the interfacial tension can be reduced, and the hydrophobic alkylated benzotriazole ultraviolet absorber can be dispersed into tiny particles or micelles, reducing phase separation and precipitation; on the other hand, the alkylated benzotriazole ultraviolet absorber is wrapped in the three-dimensional gel network structure, and the gel network will restrict the molecular movement of the alkylated benzotriazole ultraviolet absorber, resulting in a decrease in absorption efficiency; but the dispersing effect of the emulsifier can make up for this defect and maintain the absorption efficiency.

[0032] The emulsified suspension is further added dropwise to the chitosan acetic acid solution, and the surface of the sodium alginate hydrogel quickly combines with the chitosan to form "core-shell" structured ultraviolet absorber microspheres with the sodium alginate gel wrapped with the alkylated benzotriazole ultraviolet absorber as the core and the chitosan as the shell. This prevents the alkylated benzotriazole ultraviolet absorber from directly contacting the synthetic latex, ensuring stability while further improving the sustained release of the ultraviolet absorber and extending the service life of the latex sponge product.

[0033] In addition, during the preparation process of the ultraviolet absorber microspheres provided by the present invention, the sodium alginate gel is cross-linked by calcium ions and is added dropwise to the chitosan acetic acid solution. + It can replace Ca²⁺, causing the sodium alginate network to partially de-crosslink, reducing the gel structure's constraints on alkylated benzotriazole UV absorbers, improving their molecular motion, and thus improving UV absorption efficiency; at the same time, it releases Ca²⁺ into the solution; the released Ca²⁺ can form coordination bonds with the amino or hydroxyl groups of chitosan, further enhancing the cross-linking density of the composite gel, thereby making the prepared UV absorber microspheres have a more stable structure, improving their sustained-release effect, and helping to further extend their service life.

[0034] In the present invention, the mass fraction of sodium alginate in the sodium alginate aqueous solution containing calcium chloride is preferably 1.5%, the mass fraction of calcium chloride is 1%, and the mass ratio of the alkylated benzotriazole ultraviolet absorber to the sodium alginate aqueous solution containing calcium chloride is 1:80; the emulsifier is preferably OP-10, and the added amount of OP-10 is (0.1-0.3)% by mass of the sodium alginate aqueous solution containing calcium chloride; and the mass fraction of acetic acid in the chitosan acetic acid solution is preferably 2%.

[0035] The preferred synthetic latex of the present invention is a high-solid styrene-butadiene latex with a solid content of 58%-68%, a pH value of 9.2-10.5, a viscosity of 200-1500 mPa.s, and a particle size of 260-340 nm. It is further preferred that the high-solid styrene-butadiene latex has a solid content of 66%, a pH value of 10-10.3, a viscosity of 500-800 mPa.s, and a particle size of 280-300 nm.

[0036] The preferred natural rubber latex of the present invention has a solid content of 60% and an ammonia content of 0.2%.

[0037] The preferred vulcanization package dispersion of the present invention comprises sulfur powder, an accelerator, a dispersant, an antioxidant, and water in a mass ratio of (18-27): (18-27): (3-4): (13-15): (36-54); wherein the accelerator is selected from at least one of diphenylguanidine, 2-mercaptobenzothiazole, zinc diethyldithiocarbamate, and 2-mercaptobenzothiazole zinc salt; the dispersant in the preferred vulcanization package dispersion is a mixture of bentonite and sodium methylenebisnaphthalenesulfonate in a mass ratio of 1:2; and the antioxidant is selected from at least one of 1010 and 616.

[0038] The preferred foaming agent of the present invention is a saponification product of oleic acid.

[0039] The preferred foam stabilizer of the present invention is castor oil saponification product.

[0040] The latex stabilizer of the present invention is preferably selected from at least one of potassium pyrophosphate, potassium laurate, potassium hydroxide, soybean lecithin, and casein; and is further preferably selected from at least one of potassium pyrophosphate, potassium hydroxide, and potassium laurate.

[0041] The thickener of the present invention is preferably selected from at least one of sodium carboxymethyl cellulose, gelatin, carrageenan, casein, and polypropionate, and is further preferably selected from at least one of sodium carboxymethyl cellulose and gelatin.

[0042] The preferred filler of the present invention is at least one selected from aluminum hydroxide powder, silicate powder, and hollow glass microspheres.

[0043] The latex sponge product provided by the present invention introduces a UV absorbing dispersion so that the addition of the UV absorber not only does not affect the stability of the latex, but also, through the synergistic effect with other components, the prepared latex sponge product still has good physical properties and surface properties after long-term exposure and oxidation.

[0044] The latex sponge product provided by the present invention can maintain stable appearance and physical properties under the action of oxygen and sunlight for a long time, improve the antioxidant and UV resistance of synthetic latex sponge materials, extend the service life, improve the use value of latex sponge, meet people's requirements for high-quality sponge materials, have very important economic and social significance, and play a positive role in promoting the development of the latex material industry.

[0045] The latex sponge product provided by the present invention can be produced and used normally, and does not cause migration and volatilization of the ultraviolet absorber due to high temperature and water washing during the production process, thereby ensuring the product stability of the latex sponge product. At the same time, the latex sponge product provided by the present invention can ensure that it will not produce yellowing, powdering, cracking, etc. for a long time in an outdoor natural environment, and maintains good surface and physical properties, breaking the concept that bedding sponge products cannot be washed or exposed to the sun. The product has a simple preparation process, relatively low cost, high economic value, and is easy to achieve large-scale production.

[0046] Another object of the present invention is to provide a method for preparing the latex sponge product as described above, comprising the steps of: S1: After stirring the components in the raw materials according to the formula, a pre-dispersed latex is obtained; Preferably, in this step, the raw materials are added in a certain order and stirred and matured, the stirring temperature is 20-30°C, and the maturation time is 1-2 hours; S2: foaming the pre-dispersed latex through a foaming device to obtain a sponge sheet; In this step, the pre-dispersed latex, the active agent dispersion, and the curing agent dispersion are added to a foaming device for foaming. The active agent dispersion is preferably a zinc oxide dispersion, which can effectively serve as a vulcanization active agent. Due to its unique properties, it can reflect ultraviolet rays and assist in the coagulation of the latex. The curing agent dispersion is preferably selected from at least one of sodium fluorosilicate and ammonium sulfate. Specifically, the mass ratio of the pre-dispersed latex to the active agent dispersion and the curing agent dispersion is preferably 100:(5-7):(4-6). The latex foaming is to control the amount of air intake, and the foaming ratio is controlled at about 7-13 times according to the density requirements of the finished product; S3: vulcanizing and shaping the sponge sheet, pressing and drying the sponge sheet to obtain a latex sponge product; The sponge sheet is preferably shaped using infrared and radio frequency methods, followed by high-temperature vulcanization to achieve vulcanization setting. Specifically, vulcanization setting involves first irradiating the surface of the synthetic latex foam with infrared radiation to set the shape, followed by a second step of shaping the foam as a whole using radio frequency equipment. The product is then subjected to 100°C steam for 20-35 minutes. The water-pressing drying process involves washing and dehydrating the latex sponge product through a water tank and a roller, followed by drying in an oven at 100-140°C for 0.3-2 hours.

[0047] The preparation method of the latex sponge product provided by the present invention has a simple preparation process and good stability. The prepared latex sponge product improves the antioxidant and anti-ultraviolet properties of the latex sponge product by introducing the benzotriazole ultraviolet absorber based on the high efficiency and stability of the benzotriazole ultraviolet absorber, thereby extending the service life of the latex sponge product. Furthermore, by introducing the benzotriazole ultraviolet absorber in the form of an ultraviolet absorbing dispersion, the uniformity of the dispersion of the benzotriazole ultraviolet absorber in the latex sponge product is improved, thereby further improving the anti-aging performance of the latex sponge product, improving its use value, and extending its service life.

[0048] The latex sponge product provided by the present invention can be used in the fields of household items, clothing decoration, etc.

[0049] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below.

[0050] Unless otherwise specified, in the embodiments and comparative examples of the present invention, the benzotriazole compound is 2, (2-hydroxy-5-methylphenyl) benzotriazole (UV-P), with a molecular weight of 225.25. The structural formula of the benzotriazole compound is as follows: ; The alkylated benzotriazole UV absorber is 2-(2H-benzotriazole)-5-n-octyloxyphenol, with a molecular weight of 340 and the structural formula is as follows: ; The preparation method of the alkylated benzotriazole ultraviolet absorber is as follows: 2.3 g of the desired benzotriazole compound (UV-P), 5 mL of ethylene glycol monomethyl ether, 1 mL of DMF, 1 g of KI, 1.4 g of potassium carbonate, and 0.015 mol of RBr (octyl bromide) were added to a three-necked flask. The mixture was heated to reflux (85°C) for 10 h. After cooling to room temperature, 30 mL of toluene and 20 mL of water were added, stirred, and diluted with dilute hydrochloric acid to adjust the pH to 3. The mixture was stirred and the water was removed. The toluene layer was washed twice with water. The toluene was evaporated to approximately 5 mL. 10 mL of ethanol was added, stirred, and cooled. Solids precipitated. The crystals were rinsed again with ethanol three times to obtain crystals of the increased molecular weight alkylated benzotriazole UV absorber 2-(2H-benzotriazole)-5-n-octyloxyphenol.

[0051] The UV absorber microspheres were prepared as follows: The 2-(2H-benzotriazole)-5-n-octyloxyphenol crystals to be encapsulated were added to a 1.5% by mass sodium alginate solution (containing a certain amount of calcium chloride, with a calcium chloride concentration of 1%). An appropriate amount of OP-10 emulsifier (the amount of OP-10 added was 0.2% of the mass of the sodium alginate solution containing calcium chloride) was added. The solution was heated to 35°C and stirred for 10 minutes to achieve rapid emulsification. The resulting emulsified suspension was placed in an insulated syringe and, under magnetic stirring, added dropwise to a beaker containing a 0.5% by mass chitosan acetic acid solution (with a 2% by mass acetic acid content). Stirring was continued for 10 minutes, filtered, and washed with water to obtain uniform white spheres, which were the encapsulated UV absorber microspheres.

[0052] Example 1 This embodiment provides a method for preparing a latex sponge product, comprising the following steps: S1: The raw materials include the following components in parts by weight: 90 parts of synthetic latex; 10 parts of natural rubber latex; 6 parts of vulcanization package dispersion; 3 parts of foaming agent; 1.5 parts of foam stabilizer; 2 parts of latex stabilizer; 1 part thickener; 12 parts of filler; 3 parts of UV absorbing dispersion; The UV absorbing dispersion includes benzotriazole UV absorber microspheres, dispersant and water in a mass ratio of 52:3:45, and the dispersant is a phenol dispersion; the synthetic latex is a high-solid styrene-butadiene latex with a solid content of 66%; the solid content of the natural latex is 60%, and the ammonia mass content is 0.2%; the vulcanization package dispersion includes sulfur powder, accelerator, dispersant, antioxidant and water in a mass ratio of 25:25:3:14:45; the accelerator is a mixture of accelerator M and accelerator ZDC in a mass ratio of 1:1; the dispersant is a mixture of bentonite and sodium methylene bisnaphthalene sulfonate in a mass ratio of 1:2; the antioxidant is 1010; the foaming agent is a saponification product of oleic acid; the foam stabilizer is a saponification product of castor oil; the latex stabilizer is potassium hydroxide; the thickener is CMCC; and the filler is silicate powder. According to the formula, each component in the raw material was stirred and matured at 25°C for 2 hours to obtain a pre-dispersed latex; S2: adding pre-dispersed latex, active agent dispersion, and curing agent dispersion in a mass ratio of 100:6:5 to a foaming device for physical foaming, and spreading the foam after the foaming multiple is sufficient to obtain a sponge sheet; wherein the active agent dispersion is zinc oxide dispersion, and the curing agent dispersion is sodium fluorosilicate; S3: The sponge sheet is shaped by infrared and radio frequency, and then vulcanized and shaped by steam vulcanization at a high temperature of 100°C for 30 minutes; the sponge sheet is roller-pressed to remove residual small particles, and then dried at 120°C for 1 hour to obtain a latex sponge product.

[0053] Example 2 The difference between this embodiment and embodiment 1 is that the raw materials include the following components: 90 parts of synthetic latex; 10 parts of natural rubber latex; 6 parts of vulcanization package dispersion; 3 parts of foaming agent; 1.5 parts of foam stabilizer; 2 parts of latex stabilizer; 1 part thickener; 12 parts of filler; 6 parts of UV absorbing dispersion.

[0054] Example 3 The difference between this embodiment and embodiment 1 is that the raw materials include the following components: 90 parts of synthetic latex; 10 parts of natural rubber latex; 4 parts of vulcanization package dispersion; 2 parts of foaming agent; 0.5 parts of foam stabilizer; 0.1 part of latex stabilizer; 1 part thickener; 5 parts of filler; 3 parts of UV absorbing dispersion.

[0055] Example 4 The difference between this embodiment and embodiment 1 is that the raw materials include the following components: 90 parts of synthetic latex; 10 parts of natural rubber latex; 8 parts of vulcanization package dispersion; 5 parts of foaming agent; 2 parts of foam stabilizer; 5 parts of latex stabilizer; 1 part thickener; 5 parts of filler; 3 parts of UV absorbing dispersion.

[0056] The following comparative examples are all compared with Example 1.

[0057] Comparative Example 1 This comparative example provides a method for preparing a latex sponge product, comprising the following steps: S1: The raw materials include the following components in parts by weight: 90 parts of synthetic latex; 10 parts of natural rubber latex; 6 parts of vulcanization package dispersion; 3 parts of foaming agent; 1.5 parts of foam stabilizer; 2 parts of latex stabilizer; 1 part thickener; 12 parts of filler; The synthetic latex is a high-solid styrene-butadiene latex with a solid content of 66%; the solid content of the natural latex is 60% and the ammonia content is 0.2% by mass; the vulcanization package dispersion includes sulfur powder, accelerator, dispersant, antioxidant and water in a mass ratio of 25:25:3:14:45; the accelerator is a mixture of accelerator M and accelerator ZDC in a mass ratio of 1:1; the dispersant is a mixture of bentonite and sodium methylene bisnaphthalene sulfonate in a mass ratio of 1:2; the antioxidant is 1010; the foaming agent is a saponification product of oleic acid; the foam stabilizer is a saponification product of castor oil; the latex stabilizer is potassium hydroxide; the thickener is CMCC; and the filler is silicate powder. According to the formula, each component in the raw material was stirred and matured at 25°C for 2 hours to obtain a pre-dispersed latex; S2: adding pre-dispersed latex, active agent dispersion, and curing agent dispersion in a mass ratio of 100:6:5 to a foaming device for physical foaming, and spreading the foam after the foaming multiple is sufficient to obtain a sponge sheet; wherein the active agent dispersion is zinc oxide dispersion, and the curing agent dispersion is sodium fluorosilicate; S3: The sponge sheet is shaped by infrared and radio frequency, and then vulcanized and shaped by steam vulcanization at a high temperature of 100°C for 30 minutes; the sponge sheet is roller-pressed to remove residual small particles, and then dried at 120°C for 1 hour to obtain a latex sponge product.

[0058] Comparative Example 2 This comparative example provides a method for preparing a latex sponge product, comprising the following steps: S1: The raw materials include the following components in parts by weight: 90 parts of synthetic latex; 10 parts of natural rubber latex; 6 parts of vulcanization package dispersion; 3 parts of foaming agent; 1.5 parts of foam stabilizer; 2 parts of latex stabilizer; 1 part thickener; 12 parts of filler; 3 parts of UV-P dispersion; The UV-P dispersion includes UV-P, dispersant and water in a mass ratio of 52:3:45, and the dispersant is phenol dispersion; the synthetic latex is high-solid styrene-butadiene latex with a solid content of 66%; the solid content of natural latex is 60%, and the ammonia mass content is 0.2%; the vulcanization package dispersion includes sulfur powder, accelerator, dispersant, antioxidant and water in a mass ratio of 25:25:3:14:45; the accelerator is a mixture of accelerator M and accelerator ZDC in a mass ratio of 1:1; the dispersant is a mixture of bentonite and sodium methylene bisnaphthalene sulfonate in a mass ratio of 1:2; the antioxidant is 1010; the foaming agent is a saponification product of oleic acid; the foam stabilizer is a saponification product of castor oil; the latex stabilizer is potassium hydroxide; the thickener is CMCC; and the filler is silicate powder. According to the formula, each component in the raw material was stirred and matured at 25°C for 2 hours to obtain a pre-dispersed latex; S2: adding pre-dispersed latex, active agent dispersion, and curing agent dispersion in a mass ratio of 100:6:5 to a foaming device for physical foaming, and spreading the foam after the foaming multiple is sufficient to obtain a sponge sheet; wherein the active agent dispersion is zinc oxide dispersion, and the curing agent dispersion is sodium fluorosilicate; S3: The sponge sheet is shaped by infrared and radio frequency, and then vulcanized and shaped by steam vulcanization at a high temperature of 100°C for 30 minutes; the sponge sheet is roller-pressed to remove residual small particles, and then dried at 120°C for 1 hour to obtain a latex sponge product.

[0059] Comparative Example 3 This comparative example provides a method for preparing a latex sponge product, comprising the following steps: S1: The raw materials include the following components in parts by weight: 90 parts of synthetic latex; 10 parts of natural rubber latex; 6 parts of vulcanization package dispersion; 3 parts of foaming agent; 1.5 parts of foam stabilizer; 2 parts of latex stabilizer; 1 part thickener; 12 parts of filler; 3 parts of alkylated UV-P dispersion; The alkylated UV-P dispersion comprises alkylated UV-P (2-(2H-benzotriazole)-5-n-octyloxyphenol, prepared according to the method described above), dispersant and water in a mass ratio of 52:3:45, and the dispersant is a phenol dispersion; the synthetic latex is a high-solid styrene-butadiene latex with a solid content of 66%; the solid content of the natural latex is 60%, and the ammonia content is 0.2%; the vulcanization package dispersion comprises sulfur powder, accelerator, dispersant, antioxidant and water in a mass ratio of 25:25:3:14:45; the accelerator is a mixture of accelerator M and accelerator ZDC in a mass ratio of 1:1; the dispersant is a mixture of bentonite and sodium methylene bisnaphthalene sulfonate in a mass ratio of 1:2; the antioxidant is 1010; the foaming agent is a saponification product of oleic acid; the foam stabilizer is a saponification product of castor oil; the latex stabilizer is potassium hydroxide; the thickener is CMCC; and the filler is silicate powder. According to the formula, each component in the raw material was stirred and matured at 25°C for 2 hours to obtain a pre-dispersed latex; S2: adding pre-dispersed latex, active agent dispersion, and curing agent dispersion in a mass ratio of 100:6:5 to a foaming device for physical foaming, and spreading the foam after the foaming multiple is sufficient to obtain a sponge sheet; wherein the active agent dispersion is zinc oxide dispersion, and the curing agent dispersion is sodium fluorosilicate; S3: The sponge sheet is shaped by infrared and radio frequency, and then vulcanized and shaped by steam vulcanization at a high temperature of 100°C for 30 minutes; the sponge sheet is roller-pressed to remove residual small particles, and then dried at 120°C for 1 hour to obtain a latex sponge product.

[0060] The latex sponge products prepared in the above embodiments and comparative examples were tested, and the testing method is as follows: 1. Gray scale grade: Refer to GB / T 250-2008. Gray scale grade is determined under standard light source, with grade 1 being the worst and grade 5 being the best. The actual laboratory light aging test uses a xenon arc lamp for 330 hours of exposure, which is approximately equivalent to one year of natural exposure.

[0061] 2. Latex stability: It is determined by the mechanical stability and the length of time on the machine during the actual production process. The better the stability of the latex, the longer the continuous production time.

[0062] The test results are shown in Table 1: Table 1 Test Method Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Latex stability SH / T 1151.1-2019 √ √ √ √ √ × × Gray scale level ISO 4892-2:2013 2 3 2 2 1 2 2 As can be seen from the data in Table 1, the latex sponge products prepared in various embodiments of the present invention have good latex stability during the preparation process, and compared with the solution of Comparative Example 1 without adding ultraviolet absorber, the anti-aging performance is improved.

[0063] In Comparative Example 2, UV-P was used as the UV absorber, and in Comparative Example 3, alkylated UV-P (2-(2H-benzotriazole)-5-n-octyloxyphenol) was used as the UV absorber, both of which resulted in poor latex stability and affected normal production.

[0064] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A latex sponge product, characterized in that: The raw materials include the following components in parts by weight: 90 parts of synthetic latex; 10 parts of natural rubber latex; 4-8 parts of vulcanization package dispersion; 2-5 parts of foaming agent; Foam stabilizer 0.5-2 parts; 0.1-5 parts of latex stabilizer; Thickener 0-2 parts; 5-30 parts of filler; 1-5 parts of UV absorbing dispersion; The ultraviolet absorbing dispersion comprises a benzotriazole ultraviolet absorber, a dispersant and water in a mass ratio of (50-55): (1-5): (45-50).

2. The latex sponge product according to claim 1, wherein The benzotriazole ultraviolet absorber is an alkylated benzotriazole ultraviolet absorber.

3. The latex sponge product according to claim 2, wherein The alkylated benzotriazole ultraviolet absorber is prepared according to the following method: A benzotriazole compound, ethylene glycol monomethyl ether, N,N-dimethylformamide, KI, potassium carbonate, and alkyl bromide are mixed, heated to reflux, reacted, cooled to room temperature, toluene and water are added, stirred, the pH is adjusted to acidic, stirred, and crystallized to obtain an alkylated benzotriazole UV absorber.

4. The latex sponge product according to claim 3, wherein The usage ratio of the benzotriazole compound, the ethylene glycol monomethyl ether, the N,N-dimethylformamide, the KI, the potassium carbonate, and the bromoalkane is (2-3) g: (2-8) mL: (1-3) mL: (0.5-1.5) g: (1-2) g: (0.01-0.02) mol.

5. The latex sponge product according to claim 2, wherein The alkylated benzotriazole ultraviolet absorber is ultraviolet absorber microspheres obtained by encapsulation treatment.

6. The latex sponge product according to claim 5, wherein The ultraviolet absorber microspheres are prepared as follows: The alkylated benzotriazole ultraviolet absorber is mixed with a sodium alginate aqueous solution containing calcium chloride, an emulsifier is added, the temperature is raised to 35° C., and stirring is performed to obtain an emulsified suspension; the emulsified suspension is placed in a heat-insulating syringe and dropwise added to a chitosan acetic acid solution under magnetic stirring, followed by stirring, filtering, and washing with water to obtain ultraviolet absorber microspheres.

7. The latex sponge product according to any one of claims 1 to 6, wherein: The synthetic latex is styrene-butadiene latex, has a solid content of 58%-68%, a pH value of 9.2-10.5, a viscosity of 200-1500 mPa.s, and a particle size of 260-340 nm.

8. The latex sponge product according to any one of claims 1 to 6, wherein: The natural rubber latex has a solid content of 60% and an ammonia content of 0.2%.

9. The latex sponge product according to any one of claims 1 to 6, wherein: The vulcanization package dispersion includes sulfur powder, an accelerator, a dispersant, an antioxidant, and water in a mass ratio of (18-27): (18-27): (3-4): (13-15): (36-54).

10. The latex sponge product according to claim 9, wherein The accelerator is selected from at least one of diphenylguanidine, 2-mercaptobenzothiazole, zinc diethyldithiocarbamate, and 2-mercaptobenzothiazole zinc salt.

11. The latex sponge product according to any one of claims 1 to 6, wherein: The latex stabilizer is selected from at least one of potassium pyrophosphate, potassium laurate, potassium hydroxide, soybean lecithin and casein.

12. The latex sponge product according to any one of claims 1 to 6, wherein: The thickener is selected from at least one of sodium carboxymethyl cellulose, gelatin, carrageenan, casein, and polypropionate.

13. The latex sponge product according to any one of claims 1 to 6, characterized in that: The filler is selected from at least one of aluminum hydroxide powder, silicate powder, and hollow glass microspheres.

14. A method for preparing a latex sponge product according to any one of claims 1 to 13, characterized in that: The steps include: S1: After stirring the components in the raw materials according to the formula, a pre-dispersed latex is obtained; S2: foaming the pre-dispersed latex by a foaming device to obtain a sponge sheet; S3: vulcanizing, shaping, pressing and drying the sponge sheet to obtain a latex sponge product.