CN110982131A - Method for producing latex foamed product by using low-protein latex - Google Patents

Abstract

The invention relates to the technical field of latex foamed products, in particular to a method for producing a latex foamed product by using low-protein latex. The natural latex foaming product comprises, by weight, 100 parts of latex, 2-5 parts of a vulcanizing agent, 0.5-6 parts of a foaming agent, 1-5 parts of a foam stabilizer, 0.5-1.5 parts of a gelling agent, 3-5 parts of an active agent, 3-12 parts of an auxiliary agent and 1-15 parts of a filler. The natural latex in the raw materials for preparing the natural latex foaming product provided by the invention is low-protein natural latex, and has the characteristics of nature, environmental protection, no pollution, no toxicity, allergy resistance and the like. And a proper amount of the foam stabilizer and the activator are added in the production and preparation process of the latex foamed product, and the production process parameters are changed, so that the prepared latex foamed product has good foam stability, uniform cell size, regular and stable cell structure, few internal defects of the product and the like, the prepared foamed product has good resilience, and the tensile strength, the elongation at break, the rebound rate and the like are all remarkably improved.

Description

Method for producing latex foamed product by using low-protein latex

Technical Field

The invention relates to the technical field of latex foamed products, in particular to a method for producing a latex foamed product by using low-protein latex.

Background

The natural rubber is an elastic solid obtained by coagulating and drying a natural latex collected from Brazilian rubber trees. The rubber hydrocarbon (polyisoprene) content is more than 90%, and the rubber hydrocarbon also contains a small amount of protein, fatty acid, sugar, ash and the like. The natural rubber has the performances of high elasticity, high strength, wear resistance, tear resistance, acid and alkali resistance, corrosion resistance, excellent insulativity, flexibility and the like, is widely applied to the aspects of industrial and agricultural industry, national defense, traffic, transportation, mechanical manufacture, the field of medicine and health, daily life and the like, and cannot be replaced by other materials. The natural rubber foam material is also called natural latex sponge, is a porous open type low-density material, and is a rubber continuous foam body. The current method of preparing natural latex sponges is the Dunlop method. The Dunlop method is basically characterized in that: after the latex is foamed, it may be coagulated with sodium fluorosilicate, a gelling agent with retarding action, and then hardened in a steam chamber. The basic processes are latex preparation, foaming, gelling and setting, vulcanization, washing and drying.

The proteins contained in the natural latex foam are mainly proteins firmly bound in the micelles and proteins in the whey pressure, and the remaining water-soluble proteins are allergens. Meanwhile, the macromolecular protein combined on the surface of the colloidal particles can be degraded to regenerate water-soluble protein, the protein can migrate to the inner surface of the foaming material in the process of producing the foaming material, most of the soluble protein in the finished foaming material is distributed on the inner surface of the foaming material, and at least 4 soluble polypeptides in the soluble protein can cause allergic reaction of a human body. Meanwhile, some problems of the natural latex products are gradually exposed during the use of the foaming material. Investigation shows that a large proportion of users in high-risk groups such as medical workers, patients who have undergone multiple operations and the like who are in contact with the latex foam material for a long time can have anaphylactic reactions when contacting with latex, allergic reactions such as bronchial asthma, contact urticaria, conjunctivitis, rhinitis and the like can occur in allergic people contacting with natural latex products, and anaphylactic shock and even death can be caused in severe cases.

In addition, the existing sponge products also have the problems of large compression set, low tensile strength and elongation at break and unsatisfactory rebound rate of prepared sponge products due to factors such as nonuniform cell size, rough cell structure, internal defects of the products and the like.

In conclusion, there is a need to design a low-protein natural latex foam material and a production method thereof, wherein the low-protein natural latex foam material has low latex protein content, effectively avoids allergic reaction of allergic users, and has the advantages of simple production method, low cost, high production efficiency, good comprehensive performance, health and environmental protection.

Disclosure of Invention

In order to solve the technical problems, the first aspect of the invention provides a natural latex foamed product, which comprises, by weight, 100 parts of latex, 2-5 parts of a vulcanizing agent, 0.5-6 parts of a foaming agent, 1-5 parts of a foam stabilizer, 0.5-1.5 parts of a gelling agent, 3-5 parts of an active agent, 3-12 parts of an auxiliary agent and 1-15 parts of a filler.

As a preferable technical scheme, the foaming agent is selected from one or more of cetyl trimethyl ammonium bromide, cetyl pyridinium bromide, cetyl propylamine, oleic acid, ricinoleic acid soap, saponin, organic siloxane and phosphate.

As a preferable technical scheme, the foaming agent is cetyl pyridinium bromide and organosiloxane, and the weight ratio of the foaming agent to the organosiloxane is (1-3): 1.

as a preferred technical scheme, the organic siloxane is polyether modified organic siloxane.

As a preferable technical scheme, the active agent comprises zinc oxide and an anionic surfactant, and the weight ratio of the zinc oxide to the anionic surfactant is (2-3): 1.

as a preferable technical scheme, the anionic surfactant is selected from one or more of fatty alcohol sulfate, fatty acid salt, alkyl allyl sulfonate and alkyl benzene sulfonate.

As a preferred embodiment, the alkylbenzene sulfonate comprises sodium 4-octylbenzenesulfonate and sodium hexadecylbenzenesulfonate.

As a preferable technical scheme, the weight ratio of the 4-octyl sodium benzene sulfonate to the hexadecyl sodium benzene sulfonate is (1: 2) to (2: 1).

As a preferable technical scheme, the protein content of the latex is 0.05-1.0 wt%.

As a preferred technical scheme, the natural latex foam product comprises a latex mattress, a latex pillow, a throw pillow, a waist pillow, a cushion, an automobile headrest, a foam shoe product and sponge.

As a preferred technical scheme, the latex is ammonia-free latex or low-ammonia latex.

In a second aspect, the present invention provides a method for preparing the natural latex foamed product, comprising the following steps:

1) mixing latex: stirring and mixing the latex, the auxiliary agent and the vulcanizing agent according to the formula ratio for 30min to obtain a compound latex for later use, standing and curing for 12-72 hours;

2) mechanical bubble: adding the filler, the foaming agent and the foam stabilizer in the formula amount into the compound rubber material for mixing, stirring and foaming the mixed system in a mechanical foaming machine at the rotating speed of 200-350 r/min for 1-5 min, and then reducing the rotating speed to 50-60 r/min for uniform foaming for 1-3 min; then adding an active agent, stirring for 0.5-2 min, adding a gelling agent, and stirring for 1-3 min to obtain a foamed rubber material;

3) injecting a foam rubber material into a film: injecting the foaming rubber material into a mold, and shaping at 95-110 ℃;

4) and (3) vulcanization: vulcanizing the formed prototype together with the model at the temperature of 90-110 ℃ for 15-30 min;

5) and (3) post-treatment: stripping, washing and drying to obtain the product.

The natural latex in the raw materials for preparing the natural latex foamed product is prepared from natural latex through deproteinizing the natural latex to obtain deproteinized latex, and then the deproteinized latex and other raw materials are used together to prepare the natural latex foamed product, wherein the pure natural low-protein latex foamed product has the characteristics of nature, environmental friendliness, no pollution, no toxicity, allergy resistance and the like. And residual protein in the foaming material is adsorbed in the foaming material under the action of a specific active agent, a foaming agent, a foam stabilizer and the like, so that the allergic protein is wrapped, the migration speed of the allergic protein to the surface of the foaming material is reduced, and the harm of allergy and the like brought by the latex product is further reduced. Can effectively avoid the safety hazard caused by protein allergy in latex in high risk groups such as medical workers, patients who have undergone multiple operations and the like and are in contact with the latex foaming material for a long time. Because a proper amount of the foam stabilizer is added in the production and preparation process of the latex foaming product, the production process parameters of the traditional latex foaming product are changed, the prepared latex foaming product has good foam stability, the size of the foam pores is uniform, the pore structure is regular and stable, the internal defects of the product are few, and the like, the compression permanent deformation of the prepared foaming product is small, and the tensile strength, the elongation at break, the rebound rate and the like are all obviously improved. The foam rubber is widely applied to the fields of latex mattresses, latex pillows, throw pillows, waist pillows, cushions, automobile headrests, foamed shoe products, sponges and other products.

Detailed Description

The technical features of the technical solutions provided by the present invention are further clearly and completely described below with reference to the specific embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The words "preferred", "preferably", "more preferred", and the like, in the present invention, refer to embodiments of the invention that may provide certain benefits, under certain circumstances. However, other embodiments may be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, nor is it intended to exclude other embodiments from the scope of the invention.

When an amount, concentration, or other value or parameter is expressed as a range, preferred range, or as a range of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted to include the ranges "1 to 4", "1 to 3", "1 to 2 and 4 to 5", "1 to 3 and 5", and the like. When a range of values is described herein, unless otherwise stated, the range is intended to include the endpoints thereof and all integers and fractions within the range.

In addition, the indefinite articles "a" and "an" preceding an element or component of the invention are not intended to limit the number requirement (i.e., the number of occurrences) of the element or component. Thus, "a" or "an" should be read to include one or at least one, and the singular form of an element or component also includes the plural unless the stated number clearly indicates that the singular form is intended.

The invention provides a natural latex foamed product, which comprises the following raw materials, by weight, 100 parts of latex, 2-5 parts of a vulcanizing agent, 0.5-6 parts of a foaming agent, 1-5 parts of a foam stabilizer, 0.5-1.5 parts of a gelling agent, 3-5 parts of an active agent, 3-12 parts of an auxiliary agent and 1-15 parts of a filler.

The latex in the present invention is a milky white liquid that looks like milk. In the present invention, a low-protein latex obtained by deproteinizing a natural latex is used. The deproteinization process is not particularly limited, and methods known to those skilled in the art can be used, including but not limited to deproteinization with protease, wherein the protease used is not particularly limited, and includes but not limited to one or more of trypsin, alkaline protease, papain, and neutral protease.

The natural latex for deproteinization treatment in the present invention is composed of rubber hydrocarbon, protein, lipid, water-soluble substance, ash, inorganic salt, water, inorganic salt and trace amount of ribonucleic acid and thiol. Most latex particles are spherical, and some latex particles on rubber trees are pear-shaped, the particle size of the latex particles is approximately distributed between 15nm and 3 mu m, the inner layer of the latex particles is cis-1, 4-polyisoprene rubber hydrocarbon with the content of about 94 percent, and the outer layer of the latex particles is coated by a certain amount of protein phospholipid and other substances. The hydrocarbon and protein in natural latex are susceptible to branching and crosslinking reactions. Since the natural latex contains a certain amount of protein, the protein is adsorbed on the surface of the rubber particles, which makes the rubber product susceptible to mildew, and the protein can become an allergen to cause anaphylaxis. Meanwhile, in the process of manufacturing the natural latex product, the foaming performance of the foaming material is influenced because the surface of the product generates viscosity, and the uniformity of the diameter, distribution and the like of the pores of the manufactured product, the usability and the like of the product are greatly influenced.

The vulcanizing agent in the invention is a compound which converts linear macromolecules of latex into a three-dimensional network structure under certain temperature and pressure conditions. The vulcanizing agent is not particularly limited, and includes, but is not limited to, sulfur, peroxides, metal oxides, quinone oxime compounds, amine compounds, and the like.

The foaming agent in the invention is a substance capable of reducing the surface tension of the system to form foam, and a physical foaming agent or a chemical foaming agent can be selected. The chemical foaming agent can be selected from surfactant foaming agents, and the surfactant can be selected from one or more of nonionic surfactant, cationic surfactant and anionic surfactant.

In some embodiments, the foaming agent is selected from one or more of cetyltrimethylammonium bromide, cetylpyridinium bromide, cetylpropylamine, oleic acid, ricinoleic acid soap, saponin, organosiloxane, phosphate.

Preferably, the foaming agent is cetyl pyridinium bromide (CAS: 140-72-7) and organosiloxane, and the weight ratio is (1-3): 1.

in some embodiments, the organosiloxane is a polyether modified organosiloxane.

The polyether modified organic siloxane is organic silicon nonionic surfactant with unique performance which is prepared by graft copolymerization of polyether and dimethyl siloxane.

In some preferred embodiments, the polyether modified organosiloxane has a viscosity of 800 to 2000CP at 25 ℃.

The polyether modified organic siloxane can be prepared by a chemical reaction method, for example, unsaturated polyether and hydrogen-containing silicone oil react for a period of time at a certain temperature under the condition that a platinum rhodium complex solution is used as a catalyst. It can also be purchased from commercial sources such as Hongya silicone Co., Ltd, Dongguan.

The activator is a component capable of activating a vulcanization system, fully playing the vulcanization role of a vulcanizing agent, reducing the consumption of the vulcanizing agent and shortening the vulcanization time.

In some embodiments, the active agent comprises zinc oxide and an anionic surfactant, and the weight ratio of the zinc oxide to the anionic surfactant is (2-3): 1.

the anionic surfactant in the present invention is a surfactant that can generate hydrophobic anions in water, and includes various fatty acids, such as oleic acid, stearic acid, and the like, and various anionic surfactants known to those skilled in the art can be selected.

In some embodiments, the anionic surfactant is selected from one or more of fatty alcohol sulfates, fatty acid salts, alkyl allyl sulfonates, alkyl benzene sulfonates.

Preferably, the alkylbenzene sulfonate comprises sodium 4-octylbenzenesulfonate and sodium hexadecylbenzenesulfonate.

Preferably, the weight ratio of the 4-octyl sodium benzene sulfonate to the sodium hexadecylbenzene sulfonate is (1: 2) - (2: 1).

Further, the weight ratio of the 4-octyl sodium benzene sulfonate to the sodium hexadecylbenzene sulfonate is 1.2: 1.

further, the active agent is composed of 3 parts by weight of zinc oxide, 1 part by weight of stearic acid, 1.2 parts by weight of sodium 4-octylbenzenesulfonate, and 1 part by weight of sodium hexadecylbenzenesulfonate. According to the invention, zinc oxide reacts with stearic acid to generate zinc soap, so that the solubility and dispersibility of zinc oxide in rubber are increased, and the zinc soap and the accelerator generate a complex compound, so that the vulcanization efficiency of natural rubber is improved. In addition, zinc oxide and stearic acid can generate soluble zinc salt capable of chelating and crosslinking the precursor, and the effects of protecting weak bonds, generating shorter crosslinking bonds and increasing new crosslinking bonds are achieved. In addition, during the use process of the rubber product, the polysulfide bond of the vulcanized rubber is broken, hydrogen sulfide is generated in the process, the aging of the rubber can be accelerated, and zinc oxide can react with the hydrogen sulfide to generate zinc sulfide, so that the hydrogen sulfide is reduced, and a cross-linked network is protected; furthermore, zinc oxide also sews up broken sulphur bonds, stabilizing the cross-linked network.

Furthermore, the applicant has found that when a weight ratio of 1.2: 1, the sodium 4-octyl benzene sulfonate and the sodium hexadecylbenzene sulfonate can play a good synergistic effect with foaming agents, foam stabilizers and other components in the system, the foaming effect of the processed product is obviously improved, the size of foam holes is more uniform, the structure of the holes is regular and stable, and the mechanical properties such as permanent deformation, strength and the like are obviously improved. Probably because the difference of cohesive strength between the 4-octyl benzene sulfonic acid sodium and the hexadecyl pyridine bromide and the polyether modified organic siloxane molecular chains is small, the molecular chains can be well diffused mutually, so that tighter intermolecular force is generated among the foaming agent, the foam stabilizer and the active agent, the solubility and the dispersity of the zinc oxide can be further improved, the zinc oxide can be more uniformly dispersed in the latex, and the phenomenon that the foaming process of the zinc oxide is large and unstable due to the agglomeration of particles is avoided. Moreover, the latex melt strength can be effectively improved due to the strong interaction among the components, so that the growth of the foam pores is more stable and uniform, and the formation of foam nuclei is prevented from being blocked, thereby achieving the effect of simultaneously increasing the formation of the foam nuclei and the growth of the foam pores, enabling the foam pores of the prepared rubber product to be stable and uniform, and reducing the formation of internal defects. In addition, in the system, the structures of polyether, pyridine and the like in polyether modified organic siloxane, cetyl pyridinium bromide and the like can form stronger complexing action with zinc oxide, so that the acting force between polymer molecular chains is strengthened, even if covalent cross-linking bonds such as polysulfide bonds, monothio bonds and the like are broken in the use process of a rubber product, the product cannot be torn, and the breaking elongation of the rubber product is improved.

The foam stabilizer is a component for stabilizing foam pores formed in the foaming process, the specific components of the foam stabilizer are not particularly limited, and various surfactants can be selected as the foam stabilizer.

In some embodiments, the foam stabilizer is selected from one or more of castor oil soap, potassium oleate, glycerin, polyethylene glycol.

The gelling agent in the present invention is a component that rapidly coagulates or gels the latex. The gelling agent in the invention is one of coagulants, and sodium silicofluoride is adopted as the gelling agent in the invention. The sodium silicofluoride is made into aqueous dispersion by a ball mill for use, the total solid content is 15-25 wt%, if the total solid content is large, the viscosity is too large, the dispersion in latex is difficult, and if the total solid content is too low, the foam stability is not favorable. Since the pH of the dispersion is 5 or less, partial gelation often occurs in use, and the pH is prevented by adding a certain amount of sodium hydroxide to sodium silicofluoride and adjusting the amount to about 6, and a value exceeding 7 prolongs the gelation time, makes the foam unstable, and makes the gel soft and sticky and hardly dispersible.

The auxiliary agent in the invention comprises 5-10 parts by weight of vulcanization accelerator, 2-15 parts by weight of anti-aging agent and the like.

The vulcanization accelerator in the invention is a substance which can shorten the rubber vulcanization time, reduce the vulcanization temperature, reduce the vulcanizing agent dosage, improve the physical and mechanical properties of rubber and the like. In the present invention, the vulcanization accelerator is not particularly limited, and includes, but is not limited to, aldamines (e.g., vulcanization accelerator H), guanidines (e.g., vulcanization accelerator D), thiurams (e.g., vulcanization accelerator TMTD), thiazoles (e.g., vulcanization accelerator M), dithiocarbamates (e.g., vulcanization accelerator ZDMC), xanthates (e.g., vulcanization accelerator ZBX), thioureas (e.g., vulcanization accelerator NA-22), sulfenamides (e.g., vulcanization accelerator CZ), accelerator PX, accelerator PPP, accelerator MZ, accelerator M, and the like.

The antioxidant in the present invention is a component for inhibiting or preventing the aging of the product, and the specific components thereof are not particularly limited, and an amine antioxidant, a phenol antioxidant, a phosphorus antioxidant, a sulfur antioxidant, and the like can be selected. The anti-aging agents can be used singly or in combination.

Examples of the amine-based antioxidant include diphenylamine-based antioxidants such as octylated diphenylamine, dioctylated diphenylamine, 4 '- (α -dimethylbenzyl) diphenylamine, p- (p-toluenesulfonamide) diphenylamine, a reaction product of diphenylamine and acetone, a reaction product of diphenylamine and isobutylene, a reaction product of diphenylamine, acetone and aniline, and various alkylated diphenylamines, p-phenylene-based antioxidants such as N, N' -diphenyl-p-phenylenediamine, N-isopropyl-N '-phenyl-p-phenylenediamine, N' -di-2-naphthyl-p-phenylenediamine, N-cyclohexyl-N '-phenyl-p-phenylenediamine, N-phenyl-N' - (3-formyloxy-2-hydroxypropyl) p-phenylenediamine, N '-bis (1-methylheptyl) p-phenylenediamine, N' -bis (1, 4-dimethylpentyl) p-phenylenediamine, N '-bis (1-ethyl-3-methylpentyl) p-phenylenediamine, N- (1, 3-dimethylbutyl) -N' -phenyl-p-phenylenediamine, mixed diaryl-p-phenylenediamine, phenylhexyl-p-phenylenediamine and the like, p-phenylene-phenylenediamine 6332-naphthylamine, phenyl-naphthylamine, 2-trimethylquinoline-2, 2-dihydroquinoline-and the like, 2,6, 2,6, 2,6, 2,6, 2.

As the amine-based antioxidant, 4' - (α -dimethylbenzyl) diphenylamine, octylated diphenylamine or dioctylated diphenylamine is preferable.

Examples of the phenol-based antioxidant include 2, 6-di-t-butyl-p-cresol, 2-t-butyl-4-methoxyphenol, 3-t-butyl-4-methoxyphenol, 2, 6-di-t-butyl-4-ethylphenol, 2, 6-di-t-butyl-4-sec-butylphenol, 2- (1-methylcyclohexyl) -4, 6-dimethylphenol, 2, 6-di-t-butyl- α -dimethylamino-p-cresol, 2,4, 6-tri-t-butylphenol, styrenated phenol, alkylated phenol, 2, 6-diphenyl-4-octadecyloxyphenol, n-octadecyl-3- (3, 5-di-t-butyl-4-hydroxyphenyl) propionate, 2-t-butyl-6- (3 ' -t-butyl-5 ' -methyl-2 ' -hydroxybenzyl) -4-methylphenyl acrylate, and 2- [1- (2-hydroxy-3, 5-di-t-butyl-3, 5-di-t-pentylphenyl) -ethyl ] -4, 6-di-t-pentylphenyl acrylate.

Further, as the phenol-based antioxidant, there are reaction products of 2,2 ' -methylenebis (4-methyl-6-tert-butylphenol), 2 ' -methylenebis (4-ethyl-6-tert-butylphenol), 4 ' -methylenebis (2, 6-di-tert-butylphenol), 2 ' -methylenebis [6- (1-methylcyclohexyl) phenol, 2 ' -methylenebis (4-methylcyclohexyl) p-cresol ], 2 ' -methylenebis (6- α -methylbenzyl-p-cresol), methylene-crosslinked polyhydric alkylphenols, ethylene glycol bis [3, 3-bis (4-hydroxy-3-tert-butylphenyl) butyrate ], 4 ' -butylidenebis (6-tert-butyl-m-cresol), 2 ' -ethylidenebis (4-sec-butyl-6-tert-butylphenol), 2 ' -ethylidenebis (4, 6-di-tert-butylphenol), triethylene glycol bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate ], 1, 6-hexanediol bis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], 1,3, 5-di-tert-butyl-3-4-hydroxy-5-phenyl-dimethyl-butyl-4-propylphenol, 3-dimethyl-3-4-dimethyl-3-butyl-4-hydroxy-5-dimethyl-butyl-phenyl-5-dimethyl-5-methyl-3-4-dimethyl-butyl-3-methyl-4-butyl-tert-butyl-methyl-4-butyl-4-methyl-phenyl-4-methyl-butyl-.

Further, as the phenol type antioxidant, there are 1,1, 3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 1,3, 5-tris (3, 5-di-t-butyl-4-hydroxybenzyl) -2,4, 6-trimethylbenzene, 1,3, 5-tris (4-t-butyl-3-hydroxy-2, 6-dimethylbenzyl) isocyanurate, 1,3, 5-tris (3, 5-di-t-butyl-4-hydroxybenzyl) isocyanurate, 3, 5-tris (2-hydroxyethyl) -S-triazine-2, 4,6- (1H, 3H, 5H) trione of 3, 5-di-t-butyl-4-hydroxyhydrocinnamic acid, triester of 1,1, 3-tris (3-methyl-4-hydroxy-5-t-butylphenyl) butane, 1,3, 5-tris (3, 5-di-t-, Tetrakis [ methylene-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] methane, and the like.

Further, examples of the phenol-based antioxidant include 4,4 ' -thiobis (6-t-butyl-m-cresol), 4 ' -thiobis (6-t-butyl-o-cresol), bis (3, 5-di-t-butyl-4-hydroxybenzyl) sulfide, 2-thiobis (4-methyl-6-t-butylphenol), 2-thiodiethylene bis [3- (3, 5-di-t-butyl-4-hydroxyphenyl) propionate ], 2, 4-bis [ (octylthio) methyl ] o-cresol, N ' -hexamethylenebis (3, 5-di-t-butyl-4-hydroxyhydrocinnamide), 2,4, 6-tris (3, 5-di-t-butyl-4-hydroxybenzylthio) -1,3, 5-triazine, 2, 4-bis (n-octylthio) -6- (4-hydroxy-3, 5-di-tert-butylaniline) -1,3, 5-triazine, calcium bis (ethyl 3, 5-di-tert-butyl-4-hydroxybenzylphosphonate), diethyl 3, 5-di-tert-butyl-4-hydroxybenzylphosphonate, and the like.

As the phenol type antioxidant, 2, 6-di-t-butyl-p-cresol, 2 '-methylenebis (4-methyl-6-t-butylphenol) or 4, 4' -thiobis (6-t-butyl-m-cresol) is preferable.

Examples of the phosphorus-based antioxidant include triphenyl phosphite, diphenyl-2-ethylhexyl phosphite, diphenylisooctyl phosphite, diphenylisodecyl phosphite, diphenyltridecyl phosphite, diphenylnonylphenyl phosphite, dibutylhydrogen phosphite, 4-butylidenebis (3-methyl-6-t-butylphenyl didodecyl) phosphite, tris (2-ethylhexyl) phosphite, triisodecyl phosphite, tridecyl phosphite, tris (nonylphenyl) phosphite, tris (dinonylphenyl) phosphite, diisodecyl pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, dinonylphenyl pentaerythritol diphosphite, tris (4-oxo-2, 5-di-t-butylphenyl) phosphite, di-t-butylphenyl diphosphite, diphenyl-isodecyl phosphite, diphenyl-pentaerythritol diphosphite, diphenyl-2, 5-di-t-butylphenyl phosphite, diphenyl-2-ethyl-dodecyl phosphite, diphenyl-decyl, Tris (4-oxo-3, 5-di-tert-butylphenyl) phosphite, tris (2, 4-di-tert-butylphenyl) phosphite, 1, 3-tris (2-methyl-4-ditridecyl) phosphite-5-tert-butylphenyl) butane, 2-methylenebis (4, 6-di-tert-butylphenyl) octylphosphite, tetraphenylpropylene glycol diphosphite, tetraphenyltetratridecyl pentaerythritol tetraphosphite, 4 '-butylidenebis (3-methyl-6-tert-butylditridecyl) phosphite, 2' -ethylenebis (3-methyl-6-tert-butylphenol) fluorophosphite, cyclopentanetetrakisoctadecyl bis (octadecyl) phosphite, tris (2, 4-di-tert-butylphenyl) phosphite, and mixtures thereof, 4, 4' -isopropylidenediphenol alkyl (C12-C18) phosphite, cycloneopentanetetraylbis (2, 4-di-t-butylphenyl phosphite), cycloneopentanetetraylbis (2, 6-di-t-butyl-4-methylphenyl phosphite), cycloneopentanetetraylbis (nonylphenyl phosphite), hydrogenated bisphenol A pentaerythritol phosphite polymer, and the like.

As the phosphorus-based antioxidant, tris (nonylphenyl) phosphite, triisodecyl phosphite, triphenyl phosphite or tris (2, 4-di-t-butylphenyl) phosphite is preferable.

Examples of the sulfur-based antioxidant include dialkyl thiodipropionates such as dilauryl thiodipropionate, ditridecyl thiodipropionate, ditetradecyl thiodipropionate and distearyl thiodipropionate, and esters of alkylthiopropionic acids such as butylthiopropionic acid, octylthiopropionic acid, laurylthiopropionic acid and stearylthiopropionic acid with polyhydric alcohols, for example, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and trishydroxyethyl isocyanurate, for example, pentaerythritol tetralaurylthiopropionate.

The sulfur-based antioxidant is preferably dilauryl thiodipropionate, ditridecyl thiodipropionate, dimyristyl thiodipropionate, pentaerythritol tetralauryl thiopropionate, or the like.

The compounding agent used in the filler rubber industry can reduce the using amount of rubber and improve the mechanical property, wear resistance, tear resistance and the like of products. The filler in the present invention may be an organic filler or an inorganic filler which can be used for modifying rubber. Examples of the inorganic filler include, but are not limited to: alumina, hydrated alumina, aluminum hydroxide, magnesium oxide, talc, titanium white, titanium black, calcium oxide, calcium hydroxide, magnesium aluminum oxide, clay, pyrophyllite, bentonite, china clay, magnesium carbonate, barium sulfate, aluminum silicate, magnesium silicate, calcium carbonate (including light and heavy calcium carbonates, etc.), calcium silicate, calcium aluminosilicate, silica, white carbon, black carbon, zirconium, zirconia, magnesium sulfate, and silicon carbide (SiC), and the like. These inorganic compound fillers may be used alone or in combination of two or more.

In some embodiments, the protein content of the latex is 0.05 to 1.0 wt%.

The latex of the invention is low-protein latex obtained by deproteinizing natural latex by protease. The content of the protein is obtained by testing according to the standard on the national standard GB/T8088-2008.

The applicant has found in the course of the present invention that the possible problems of allergy, mildew, etc. are indeed avoided when using a latex with a low protein content, but that the vulcanization properties, mechanical properties, etc. of the rubber articles are also reduced. Probably, the protein in the latex is decomposed in the process of vulcanizing the latex, and amino acid and other high-activity components containing amino groups, carboxyl groups and the like are generated, and the high-activity components promote the interaction among the latex, the vulcanizing agent and the active agent in a system, promote the vulcanizing speed and the vulcanizing degree, so as to improve the mechanical property of the product, so that when the protein content in the latex is low, the mechanical property is correspondingly reduced. After the applicant adopts specific components such as a compound active agent, a foaming agent, a stabilizing agent and the like, the vulcanization performance, the mechanical performance and the like of the prepared rubber product are not influenced, and even the vulcanization performance, the mechanical performance and the like of the prepared rubber product are obviously improved. Probably because the long and short phase of 4-octyl sodium benzene sulfonate and the hydrophobic alkyl chain segment of the sodium hexadecyl benzene sulfonate are cooperated, the interaction force between the soluble zinc salt formed by the sodium 4-octyl benzene sulfonate and the stearic acid and the cetyl pyridinium bromide, the polyether modified organic siloxane and the like is further enhanced. Under the action of the components, the zinc oxide is uniformly dispersed to play a reinforcing role and also becomes a nucleating agent for forming bubble nuclei, which is beneficial to regulating and controlling the foaming performance of the product.

In some embodiments, the natural latex foamed article includes, but is not limited to, a latex mattress, a latex pillow, a throw pillow, a waist pillow, a seat cushion, an automotive headrest, a foamed article of footwear, a sponge, and the like.

In some preferred embodiments, the latex is an ammonia-free latex or a low ammonia latex.

The low-ammonia latex is latex obtained by preserving natural latex through a low-ammonia preserving system, wherein the low-ammonia preserving system and the preserving method adopt a method of BCT-2 disclosed in the patent with the publication number of CN110003541A and the paragraph [0045] of the specification.

The ammonia-free latex in the invention is latex obtained by preserving natural latex through an ammonia-free preservation system, wherein the ammonia-free preservation system and the preservation method adopt a method of BCT-2 disclosed in the patent with the publication number of CN110003541A and the paragraph [0043] of the specification.

In a second aspect, the present invention provides a method for preparing the natural latex foamed product, comprising the following steps:

1) mixing latex: stirring and mixing the latex, the auxiliary agent and the vulcanizing agent according to the formula ratio for 30min to obtain a compound latex for later use, standing and curing for 12-72 hours;

2) mechanical bubble: adding the filler, the foaming agent and the foam stabilizer in the formula amount into the compound rubber material for mixing, stirring and foaming the mixed system in a mechanical foaming machine at the rotating speed of 200-350 r/min for 1-5 min, and then reducing the rotating speed to 50-60 r/min for uniform foaming for 1-3 min; then adding an active agent, stirring for 0.5-2 min, adding a gelling agent, and stirring for 1-3 min to obtain a foamed rubber material;

3) injecting a foam rubber material into a film: injecting the foaming rubber material into a mold, and shaping at 95-110 ℃;

4) and (3) vulcanization: vulcanizing the formed prototype together with the model at the temperature of 90-110 ℃ for 15-30 min;

5) and (3) post-treatment: stripping, washing and drying to obtain the product.

The present invention will be specifically described below by way of examples. It should be noted that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention, and that the insubstantial modifications and adaptations of the present invention by those skilled in the art based on the above disclosure are still within the scope of the present invention. In addition, the starting materials used are all commercially available, unless otherwise specified.

Examples

Example 1

This example provides a natural latex foamed product, which is prepared from raw materials including, by weight, latex 100, a vulcanizing agent 3, a foaming agent 2.5, a foam stabilizer 2, a gelling agent 0.8, an activator 4, an auxiliary agent 8, and a filler 9.

The latex contains 0.65 wt% of protein, the vulcanizing agent is sulfur, the foaming agent is a mixture of cetyl pyridinium bromide and polyether modified organic siloxane (the viscosity at 25 ℃ is 800-2000 CP, and the foaming agent is purchased from Hongyan silicone Co., Ltd., Dongguan city), the weight ratio is 2.5: 1, the foam stabilizer is potassium oleate, the gelling agent is sodium silicofluoride, the active agent is composed of 3 parts by weight of zinc oxide, 1 part by weight of stearic acid, 1.2 parts by weight of 4-octylbenzene sulfonate and 1 part by weight of sodium hexadecylbenzene sulfonate, the auxiliary agent is composed of 5-10 parts by weight of vulcanization accelerator and 2-15 parts by weight of anti-aging agent, the vulcanization accelerator is TMTD, the anti-aging agent is 4, 4' - (α -dimethylbenzyl) diphenylamine, and the filler is a mixture of talcum powder and white carbon black which are equal in quantity.

The preparation method of the natural latex foaming product comprises the following steps:

1) mixing latex: stirring and mixing the latex, the auxiliary agent and the vulcanizing agent according to the formula ratio for 30min to obtain a compound latex for later use, standing and curing for 36 hours;

2) mechanical bubble: adding the filler, the foaming agent and the foam stabilizer in the formula amount into the compound rubber material for mixing, stirring and foaming the mixed system in a mechanical foaming machine at the rotating speed of about 300r/min for 3min, and then reducing the rotating speed to 60r/min for uniform foaming for 2 min; then adding an active agent, stirring for 1min, adding a gelling agent, and stirring for 2min to obtain a foamed rubber material;

3) injecting a foam rubber material into a film: injecting the foaming rubber material into a mold, and shaping at 100 ℃;

4) and (3) vulcanization: vulcanizing the formed prototype together with the model at 105 ℃ for 25 min;

5) and (3) post-treatment: stripping, washing with water for 4 times, and drying.

Example 2

This example provides a natural latex foamed product, which is prepared from raw materials including, by weight, latex 100, a vulcanizing agent 5, a foaming agent 6, a foam stabilizer 5, a gelling agent 1.5, an activator 3, an auxiliary agent 3, and a filler 15.

The latex contains 0.15 wt% of protein, the vulcanizing agent is sulfur, the foaming agent is a mixture of cetyl pyridinium bromide and polyether modified organic siloxane (the viscosity at 25 ℃ is 800-2000 CP, and the foaming agent is purchased from Hongyan silicone Co., Ltd. of Dongguan), the weight ratio is 2.5: 1, the foam stabilizer is potassium oleate, the gelling agent is sodium silicofluoride, the active agent is composed of 3 parts by weight of zinc oxide, 1 part by weight of stearic acid, 1.2 parts by weight of 4-octylbenzene sulfonate and 1 part by weight of sodium hexadecylbenzene sulfonate, the auxiliary agent is composed of 5-10 parts by weight of vulcanization accelerator and 2-15 parts by weight of anti-aging agent, the vulcanization accelerator is TMTD, the anti-aging agent is 4, 4' - (α -dimethylbenzyl) diphenylamine, and the filler is a mixture of talcum powder and white carbon black which are equal in quantity.

The preparation method of the natural latex foaming product comprises the following steps:

1) mixing latex: stirring and mixing the latex, the auxiliary agent and the vulcanizing agent according to the formula ratio for 30min to obtain a compound latex for later use, standing and curing for 36 hours;

2) mechanical bubble: adding the filler, the foaming agent and the foam stabilizer in the formula amount into the compound rubber material for mixing, stirring and foaming the mixed system in a mechanical foaming machine at the rotating speed of about 300r/min for 3min, and then reducing the rotating speed to 60r/min for uniform foaming for 2 min; then adding an active agent, stirring for 1min, adding a gelling agent, and stirring for 2min to obtain a foamed rubber material;

3) injecting a foam rubber material into a film: injecting the foaming rubber material into a mold, and shaping at 100 ℃;

4) and (3) vulcanization: vulcanizing the formed prototype together with the model at 105 ℃ for 25 min;

5) and (3) post-treatment: stripping, washing with water for 4 times, and drying.

Example 3

This example provides a natural latex foamed product, which is prepared from raw materials including, by weight, latex 100, a vulcanizing agent 3, a foaming agent 2.5, a foam stabilizer 2, a gelling agent 0.8, an activator 4, an auxiliary agent 8, and a filler 3.

The latex contains 0.65 wt% of protein, the vulcanizing agent is sulfur, the foaming agent is a mixture of cetyl pyridinium bromide and polyether modified organic siloxane (the viscosity at 25 ℃ is 800-2000 CP, and the foaming agent is purchased from Hongyan silicone Co., Ltd. of Dongguan), the weight ratio is 2.5: 1, the foam stabilizer is potassium oleate, the gelling agent is sodium silicofluoride, the active agent is composed of 3 parts by weight of zinc oxide and 1 part by weight of stearic acid, the auxiliary agent is composed of 5-10 parts by weight of vulcanization accelerator and 2-15 parts by weight of anti-aging agent, the vulcanization accelerator is TMTD, the anti-aging agent is 4, 4' - (α -dimethylbenzyl) diphenylamine, and the filler is a mixture of talcum powder and white carbon black with the same amount.

The preparation method of the natural latex foaming product comprises the following steps:

1) mixing latex: stirring and mixing the latex, the auxiliary agent and the vulcanizing agent according to the formula ratio for 30min to obtain a compound latex for later use, standing and curing for 36 hours;

2) mechanical bubble: adding the filler, the foaming agent and the foam stabilizer in the formula amount into the compound rubber material for mixing, stirring and foaming the mixed system in a mechanical foaming machine at the rotating speed of about 300r/min for 3min, and then reducing the rotating speed to 60r/min for uniform foaming for 2 min; then adding an active agent, stirring for 1min, adding a gelling agent, and stirring for 2min to obtain a foamed rubber material;

3) injecting a foam rubber material into a film: injecting the foaming rubber material into a mold, and shaping at 100 ℃;

4) and (3) vulcanization: vulcanizing the formed prototype together with the model at 105 ℃ for 25 min;

5) and (3) post-treatment: stripping, washing with water for 4 times, and drying.

Example 4

This example provides a natural latex foamed product, which is prepared from raw materials including, by weight, latex 100, a vulcanizing agent 3, a foaming agent 2.5, a foam stabilizer 2, a gelling agent 0.8, an activator 4, an auxiliary agent 8, and a filler 9.

The latex contains 0.65 wt% of protein, the vulcanizing agent is sulfur, the foaming agent is cetyl pyridinium bromide and the weight ratio of the cetyl pyridinium bromide to the foaming agent is 2.5: 1, the foam stabilizer is potassium oleate, the gelling agent is sodium silicofluoride, the active agent is composed of 3 parts by weight of zinc oxide, 1 part by weight of stearic acid, 1.2 parts by weight of 4-octyl benzene sodium sulfonate and 1 part by weight of sodium hexadecylbenzene sulfonate, the auxiliary agent is composed of 5-10 parts by weight of vulcanization accelerator and 2-15 parts by weight of anti-aging agent, the vulcanization accelerator is TMTD, the anti-aging agent is 4, 4' - (α -dimethylbenzyl) diphenylamine, and the filler is a mixture of talcum powder and white carbon black in equal amount.

The preparation method of the natural latex foaming product comprises the following steps:

1) mixing latex: stirring and mixing the latex, the auxiliary agent and the vulcanizing agent according to the formula ratio for 30min to obtain a compound latex for later use, standing and curing for 36 hours;

2) mechanical bubble: adding the filler, the foaming agent and the foam stabilizer in the formula amount into the compound rubber material for mixing, stirring and foaming the mixed system in a mechanical foaming machine at the rotating speed of about 300r/min for 3min, and then reducing the rotating speed to 60r/min for uniform foaming for 2 min; then adding an active agent, stirring for 1min, adding a gelling agent, and stirring for 2min to obtain a foamed rubber material;

3) injecting a foam rubber material into a film: injecting the foaming rubber material into a mold, and shaping at 100 ℃;

4) and (3) vulcanization: vulcanizing the formed prototype together with the model at 105 ℃ for 25 min;

5) and (3) post-treatment: stripping, washing with water for 4 times, and drying.

Example 5

This example provides a natural latex foamed product, which is prepared from raw materials including, by weight, latex 100, a vulcanizing agent 3, a foaming agent 2.5, a foam stabilizer 2, a gelling agent 0.8, an activator 4, an auxiliary agent 8, and a filler 9.

The latex contains 0.65 wt% of protein, the vulcanizing agent is sulfur, the foaming agent is a mixture of polyether modified organic siloxane (800-2000 CP at 25 ℃, purchased from Hongyan organosilicon Co., Ltd., Dongguan) with a weight ratio of 2.5: 1, the foam stabilizer is potassium oleate, the gelling agent is sodium silicofluoride, the active agent is composed of 3 parts by weight of zinc oxide, 1 part by weight of stearic acid, 1.2 parts by weight of 4-octyl benzene sodium sulfonate and 1 part by weight of sodium hexadecylbenzene sulfonate, the auxiliary agent is composed of 5-10 parts by weight of vulcanization accelerator and 2-15 parts by weight of anti-aging agent, the vulcanization accelerator is TMTD, the anti-aging agent is 4, 4' - (α -dimethylbenzyl) diphenylamine, and the filler is a mixture of talcum powder and white carbon black with the same amount.

The preparation method of the natural latex foaming product comprises the following steps:

1) mixing latex: stirring and mixing the latex, the auxiliary agent and the vulcanizing agent according to the formula ratio for 30min to obtain a compound latex for later use, standing and curing for 36 hours;

2) mechanical bubble: adding the filler, the foaming agent and the foam stabilizer in the formula amount into the compound rubber material for mixing, stirring and foaming the mixed system in a mechanical foaming machine at the rotating speed of about 300r/min for 3min, and then reducing the rotating speed to 60r/min for uniform foaming for 2 min; then adding an active agent, stirring for 1min, adding a gelling agent, and stirring for 2min to obtain a foamed rubber material;

3) injecting a foam rubber material into a film: injecting the foaming rubber material into a mold, and shaping at 100 ℃;

4) and (3) vulcanization: vulcanizing the formed prototype together with the model at 105 ℃ for 25 min;

5) and (3) post-treatment: stripping, washing with water for 4 times, and drying.

Example 6

This example provides a natural latex foamed product, which is prepared from raw materials including, by weight, latex 100, a vulcanizing agent 3, a foaming agent 2.5, a foam stabilizer 2, a gelling agent 0.8, an activator 4, an auxiliary agent 8, and a filler 9.

The latex contains 0.65 wt% of protein, the vulcanizing agent is sulfur, the foaming agent is a mixture of cetyl pyridinium bromide and polyether modified organic siloxane (the viscosity at 25 ℃ is 800-2000 CP, and the foaming agent is purchased from Hongyan silicone Co., Ltd. of Dongguan), the weight ratio is 2.5: 1, the foam stabilizer is potassium oleate, the gelling agent is sodium silicofluoride, the active agent is composed of 3 parts by weight of zinc oxide, 1 part by weight of stearic acid and 1 part by weight of sodium hexadecylbenzene sulfonate, the auxiliary agent is composed of 5-10 parts by weight of vulcanization accelerator and 2-15 parts by weight of anti-aging agent, the vulcanization accelerator is TMTD, the anti-aging agent is 4, 4' - (α -dimethylbenzyl) diphenylamine, and the filler is a mixture of talcum powder and white carbon black in equal amount.

The preparation method of the natural latex foaming product comprises the following steps:

1) mixing latex: stirring and mixing the latex, the auxiliary agent and the vulcanizing agent according to the formula ratio for 30min to obtain a compound latex for later use, standing and curing for 36 hours;

2) mechanical bubble: adding the filler, the foaming agent and the foam stabilizer in the formula amount into the compound rubber material for mixing, stirring and foaming the mixed system in a mechanical foaming machine at the rotating speed of about 300r/min for 3min, and then reducing the rotating speed to 60r/min for uniform foaming for 2 min; then adding an active agent, stirring for 1min, adding a gelling agent, and stirring for 2min to obtain a foamed rubber material;

3) injecting a foam rubber material into a film: injecting the foaming rubber material into a mold, and shaping at 100 ℃;

4) and (3) vulcanization: vulcanizing the formed prototype together with the model at 105 ℃ for 25 min;

5) and (3) post-treatment: stripping, washing with water for 4 times, and drying.

Example 7

This example provides a natural latex foamed product, which is prepared from raw materials including, by weight, latex 100, a vulcanizing agent 3, a foaming agent 2.5, a foam stabilizer 2, a gelling agent 0.8, an activator 4, an auxiliary agent 8, and a filler 9.

The latex contains 0.65 wt% of protein, the vulcanizing agent is sulfur, the foaming agent is a mixture of cetyl pyridinium bromide and polyether modified organic siloxane (the viscosity at 25 ℃ is 800-2000 CP, and the foaming agent is purchased from Hongyan silicone Co., Ltd. of Dongguan), the weight ratio is 2.5: 1, the foam stabilizer is potassium oleate, the gelling agent is sodium silicofluoride, the active agent is composed of 3 parts by weight of zinc oxide, 1.2 parts by weight of 4-octyl benzene sodium sulfonate and 1 part by weight of sodium hexadecylbenzene sulfonate, the auxiliary agent is composed of 5-10 parts by weight of vulcanization accelerator and 2-15 parts by weight of anti-aging agent, the vulcanization accelerator is TMTD, the anti-aging agent is 4, 4' - (α -dimethylbenzyl) diphenylamine, and the filler is a mixture of talcum powder and white carbon black which are equal in quantity.

The preparation method of the natural latex foaming product comprises the following steps:

1) mixing latex: stirring and mixing the latex, the auxiliary agent and the vulcanizing agent according to the formula ratio for 30min to obtain a compound latex for later use, standing and curing for 36 hours;

2) mechanical bubble: adding the filler, the foaming agent and the foam stabilizer in the formula amount into the compound rubber material for mixing, stirring and foaming the mixed system in a mechanical foaming machine at the rotating speed of about 300r/min for 3min, and then reducing the rotating speed to 60r/min for uniform foaming for 2 min; then adding an active agent, stirring for 1min, adding a gelling agent, and stirring for 2min to obtain a foamed rubber material;

3) injecting a foam rubber material into a film: injecting the foaming rubber material into a mold, and shaping at 100 ℃;

4) and (3) vulcanization: vulcanizing the formed prototype together with the model at 105 ℃ for 25 min;

5) and (3) post-treatment: stripping, washing with water for 4 times, and drying.

Performance testing

The resilience of the sponge provided in the examples was measured according to GB/T10652-2001, compression set was measured according to GB/T10653-2001, and tensile strength was measured according to GB/T2491 (the moving rate of the tensile tester jig was 800 mm/min. + -. 80 mm/min; results are shown in the following table).

TABLE 1 Performance test Table

Examples	Rebound resilience (%)	Compression set/%)	Tensile strength/MPa	Elongation at break/%
					1	71.8	6.21	0.23	297
3	59.4	9.85	0.16	254
					4	58.2	11.0	0.14	233
5	57.9	13.75	0.13	235
					6	60.9	8.24	0.17	263
7	56.6	14.0	0.13	229

As can be seen from the above table, the natural rubber latex foamed product provided by the present invention has lower compression set, higher resilience, tensile strength and better elongation at break, which is indirectly reflected from another angle, and the prepared foamed product has good foam stability, uniform cell size, regular and stable cell structure, less internal defects of the product, etc.

The foregoing examples are merely illustrative and serve to explain some of the features of the method of the present invention. The appended claims are intended to claim as broad a scope as is contemplated, and the examples presented herein are merely illustrative of selected implementations in accordance with all possible combinations of examples. Accordingly, it is applicants' intention that the appended claims are not to be limited by the choice of examples illustrating features of the invention. Also, where numerical ranges are used in the claims, subranges therein are included, and variations in these ranges are also to be construed as possible being covered by the appended claims.

Claims (10)

1. A natural latex foamed product is characterized in that raw materials for preparing the natural latex foamed product comprise, by weight, 100 parts of latex, 2-5 parts of a vulcanizing agent, 0.5-6 parts of a foaming agent, 1-5 parts of a foam buffering agent, 0.5-1.5 parts of a gelling agent, 3-5 parts of an active agent, 3-12 parts of an auxiliary agent and 1-15 parts of a filler.

2. The natural latex foamed product according to claim 1, wherein said foaming agent is selected from one or more of cetyltrimethylammonium bromide, cetylpyridinium bromide, cetylpropylamine, oleic acid, ricinolic acid soap, saponin, organosiloxane, and phosphate.

3. The natural latex foamed product according to claim 2, wherein the foaming agent is cetylpyridinium bromide and organosiloxane, and the weight ratio is (1-3): 1.

4. the natural latex foamed article according to claim 1, wherein said organosiloxane is a polyether-modified organosiloxane.

5. The natural latex foamed product according to claim 1, wherein the active agent comprises zinc oxide and an anionic surfactant in a weight ratio of (2 to 3): 1.

6. the natural latex foamed article according to claim 5, wherein said anionic surfactant is selected from one or more of fatty alcohol sulfate, fatty acid salt, alkyl allyl sulfonate, and alkyl benzene sulfonate.

7. The natural latex foamed article of claim 6, wherein said alkylbenzene sulfonates comprise sodium 4-octylbenzenesulfonate and sodium hexadecylbenzenesulfonate.

8. The natural latex foamed product according to claim 7, wherein the weight ratio of said sodium 4-octylbenzenesulfonate to said sodium hexadecylbenzenesulfonate is (1: 2) to (2: 1).

9. The foamed natural latex article according to any one of claims 1 to 8, wherein the latex has a protein content of 0.05 to 1.0 wt%.

10. The method for producing the natural latex foamed product according to any one of claims 1 to 9, comprising the steps of:

1) mixing latex: stirring and mixing the latex, the auxiliary agent and the vulcanizing agent according to the formula ratio for 30min to obtain a compound latex for later use, standing and curing for 12-72 hours;

2) mechanical bubble: adding the filler, the foaming agent and the foam stabilizer in the formula amount into the compound rubber material for mixing, stirring and foaming the mixed system in a mechanical foaming machine at the rotating speed of 200-350 r/min for 1-5 min, and then reducing the rotating speed to 50-60 r/min for uniform foaming for 1-3 min; then adding an active agent, stirring for 0.5-2 min, adding a gelling agent, and stirring for 1-3 min to obtain a foamed rubber material;

3) injecting a foam rubber material into a film: injecting the foaming rubber material into a mold, and shaping at 95-110 ℃;

4) and (3) vulcanization: vulcanizing the formed prototype together with the model at the temperature of 90-110 ℃ for 15-30 min;

5) and (3) post-treatment: stripping, washing and drying to obtain the product.