Preparation method of boneless insole

Abstract

The invention relates to a preparation method of a boneless insole, which comprises the following steps: putting polyether polyol, polyester polyol, a surfactant, a catalyst, a compatilizer, a polymeric monomer and a crosslinking monomer into a container A for mixing, and heating and stirring to obtain a component; adding diphenylmethane diisocyanate into a container B, mixing, heating and stirring to obtain a component B, and uniformly mixing the obtained component A with the component B to obtain a base material mixed component; pouring the obtained base material mixed component into a mold, and carrying out autonomous foaming to obtain the polyurethane insole; the manufacturing method comprises the following steps: opening a mold, uniformly brushing a component A on an insole precursor, adding an initiator solvent aqueous solution, closing the mold, heating and curing to obtain the boneless insole, and forming a three-dimensional network structure after a polymerization monomer and a crosslinking monomer participate in a free radical polymerization reaction, so as to limit the movement of a macromolecular chain and realize the excellent wear resistance of the insole; meanwhile, the porosity of the surface of the insole can be kept, and the breathability and deodorization performance of the insole can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of insole manufacturing, and particularly relates to a preparation method of a boneless insole. Background Art

[0002] Insoles not only enhance the wearing comfort but also have various practical functions. By providing additional cushioning and support, insoles can effectively reduce the pressure on the feet during walking or exercise, preventing foot fatigue and pain. At the same time, insoles made of antibacterial materials can inhibit the growth of bacteria, reduce odors, and keep the shoe interior clean and hygienic. In addition, insoles can increase the friction between the shoes and the feet, improve stability, and reduce the risk of slipping or spraining. For specific occasions and needs, such as sports shoes, leather shoes, or high heels, choosing the right insoles can provide additional functions and protection, thus extending the service life of the shoes.

[0003] Traditional insoles are made of materials that are prone to wear in order to ensure cushioning and elasticity. Therefore, a wear-resistant layer needs to be set on the surface. This wear-resistant layer can be artificial leather, animal skin, fiber cloth, etc., and then adhered to a polyurethane elastomer to form an insole. The wear-resistant layer is used to contact the sole instead of the polyurethane insole to avoid wear. Therefore, in the processing of traditional insoles, a wear-resistant layer needs to be pasted on the foamed polyurethane layer later, so its processing technology is relatively complex. CN118063734A discloses a substrate of a boneless polyurethane antibacterial and deodorant insole and its preparation method, by brushing a layer of acrylic primer or polyurethane primer, as well as polyurethane topcoat or acrylic topcoat on the surface of the polyurethane insole to replace the traditional surface layer such as artificial leather, animal skin, fiber cloth, etc. This patent can simplify the processing technology of the insole. However, the acrylic paint or polyurethane paint used in this patent has a very high density, which will affect the air permeability of the insole. At the same time, the nitro acid diluent used in the acrylic paint or polyurethane paint contains a large amount of organic volatile solvents, which have great potential hazards in terms of environmental protection and safety. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a preparation method of a boneless insole for the deficiencies of the above-mentioned prior art, which is characterized by including the following steps:

[0005] S1. Mix polyether polyol, polyester polyol, surfactant, catalyst, compatibilizer, polymerization monomer, and crosslinking monomer and put them into container A for stirring. After heating and stirring, component A is obtained. The heating temperature is controlled at 40 - 60°C, the rotation speed is 50 - 80 revolutions per minute, and the stirring time is 1 - 1.5 hours;

[0006] S2. Put diphenylmethane diisocyanate into container B and heat it to obtain component B, where the heating temperature is 40 - 50°C;

[0007] S3. Mix the component A and component B obtained in steps S1 and S2 evenly to obtain a base material mixed component;

[0008] S4. Pour the base material mixed component obtained in step S3 into a mold and let it foam spontaneously to obtain a polyurethane insole;

[0009] S5. Open the mold, evenly brush component A on the insole precursor, add an aqueous initiator solution, then close the mold, and heat and cure for 30 - 40 minutes at a heating temperature controlled at 50 - 70 °C to obtain a boneless insole.

[0010] With the above technical solution, by mixing polyether polyol, polyester polyol, surfactant, catalyst, compatibilizer, polymerization monomer, and crosslinking monomer and putting them into container A for stirring, and obtaining a polyol mixture component A through heating and stirring, the above is a preparation method of a boneless insole. Among them, polyether polyol is used to improve the elasticity and comfort of the insole; the polymerization monomer and crosslinking monomer do not react in steps S1 to S4, but in S5, by adding an initiator and certain temperature and time conditions, they can assist in forming a dense three-dimensional network structure on the surface, restricting the movement of polymer chains, thereby improving the wear resistance of the insole. Polyester polyol mainly acts as an adhesive to bond various materials of the insole together, improving the integrity and stability of the insole. The surfactant mainly plays the role of wetting and emulsifying during the insole forming process, which can reduce the interfacial tension and increase the wettability of the interface, thereby improving the adhesion and permeability of the coating. The catalyst plays a role in promoting chemical reactions during the insole forming process, accelerating the crosslinking reaction between polymer molecules and promoting the curing and forming of materials; by mixing diphenylmethane diisocyanate into container B for stirring and obtaining component B through heating and stirring, when diphenylmethane diisocyanate is formed, by reacting with components such as polyester polyol and polyether polyol, the crosslinking density of the insole material can be increased. Then, evenly brush component A on the obtained insole precursor for heating, and at the same time add an aqueous initiator solution. Through the secondary reaction of polyester polyol, polyether polyol, etc. with diphenylmethane diisocyanate, and radical polymerization and crosslinking on the surface, a dense wear-resistant layer is formed. In addition, this secondary reaction and radical polymerization and crosslinking are significantly different from the painting process in CN118063734A. This surface layer material does not reduce the surface wear resistance while maintaining the porosity of the polyurethane insole surface, effectively improving the breathability of the boneless insole.

[0011] The above preparation method of a boneless insole can be further set as: the polymerization monomer includes methyl methacrylate, butyl acrylate, and dodecyl methacrylate.

[0012] With the above technical solution, methyl methacrylate, butyl acrylate, and dodecyl methacrylate are added to Component A for free radical polymerization. Adding methyl methacrylate endows the insole with high mechanical stability and excellent abrasion resistance. Butyl acrylate can provide better flexibility and comfort for the insole. Dodecyl methacrylate enables the insole to have excellent weather resistance and chemical stability during the production process.

[0013] The above method for preparing a boneless insole can be further set as: the crosslinking monomer includes diacetone acrylamide and ethyl acetoacetate methacrylate.

[0014] With the above technical solution, diacetone acrylamide can easily copolymerize with other vinyl monomers to form polymers with high mechanical stability and excellent abrasion resistance, significantly improving the service life of the insole. At the same time, diacetone acrylamide has good water absorption and water retention properties. Its homopolymers or copolymers are insoluble in water but can absorb 20%-30% of their own weight in water and release water when the humidity is below 60%, making the insole fit the foot better during use and providing better support and cushioning effects; ethyl acetoacetate methacrylate can reduce the viscosity during the reaction and at the same time endow the insole with better elasticity and toughness.

[0015] The above method for preparing a boneless insole can be further set as: the initiator includes ammonium persulfate, potassium persulfate, and azodicyanovaleric acid.

[0016] The above method for preparing a boneless insole can be further set as: the concentration of the initiator aqueous solution is 0.1-2%.

[0017] With the above technical solution, the concentration range ensures that the initiator can efficiently initiate the polymerization reaction to form a polymer material. This high-efficiency initiation ability is crucial for improving production efficiency because it can shorten the production cycle and reduce production costs. The initiator concentration within the range can also ensure the stability and controllability of the polymerization reaction, avoiding product quality fluctuations caused by excessive or insufficient initiator. The concentration range of 0.1-2% helps to achieve the uniformity and consistency of the insole material. At this concentration, the initiator can be evenly distributed in the insole material, thus ensuring the uniform performance of the entire insole.

[0018] The above method for preparing a boneless insole can be further set as: when preparing Component A in step S1, an antibacterial agent and an anti-odor agent are also added to container A and stirred simultaneously.

[0019] With the above technical solution, the antibacterial agent can be a nano-silver antibacterial agent that effectively inhibits the growth of bacteria by destroying the bacterial cell membrane and inhibiting the activity of bacterial respiratory enzymes, keeping the insole clean and hygienic. The deodorant can be activated carbon that eliminates or reduces the odor in the insole by its adsorption performance, keeping the inside of the shoe fresh and hygienic. The antibacterial agent and the deodorant are directly molded into the polyurethane elastomer insole, enabling it to achieve an efficient antibacterial and deodorizing effect after contacting the sole of the foot.

[0020] The above method for preparing a boneless insole can be further set as follows: when preparing component A in step S1, an opening agent and a hardening agent are also put into container A and stirred simultaneously.

[0021] With the above technical solution, the function of the opening agent is to form micropores during the molding of the boneless insole, increasing the air permeability and moisture absorption of the insole, adjusting the softness, hardness and elasticity of the insole, improving the wearing comfort, and making the insole more comfortable. The function of the hardening agent is to harden the insole, increasing its durability and abrasion resistance. By adding the hardening agent, the insole can be made more wear-resistant and wrinkle-resistant, extending its service life. By controlling the components of the opening agent and the hardening agent, the boneless polyurethane antibacterial and deodorant insole has the characteristics of elasticity and comfort while also having wear-resistant properties, improving the service life of the product, enabling it to achieve wear-resistant and pressure-resistant characteristics without the need for an artificial leather-like wear-resistant layer. The opening agent can be an aerogel with a porous structure to improve the air permeability and moisture absorption of the insole, and the hardening agent can be a polyurethane resin to improve the durability and abrasion resistance of the insole.

[0022] The beneficial effects of the present invention:

[0023] 1. Using polyether polyol and polyester polyol as the main components, the insole has elasticity and comfort while also having the durability and abrasion resistance that were originally only possessed by the artificial leather layer. After the polymerization monomers and cross-linking monomers participate in the free radical polymerization reaction, a three-dimensional cross-linked network structure can be formed, further improving the comfort and abrasion resistance of the insole, which makes the insole have a longer service life and a simpler process.

[0024] 2. During the preparation process, an antibacterial agent and a deodorant are added, making the resulting insole have good antibacterial and deodorizing effects, effectively solving the problems of foot odor, beriberi, etc. caused by traditional insoles being prone to moisture and bacterial growth after sweating, and further improving foot health.

[0025] 3. By uniformly brushing component A on the insole precursor and introducing a free radical polymerization and cross-linking system, the density and abrasion resistance of the insole precursor surface can be further improved; at the same time, different from the painting process, more porous structures can still be maintained on the insole surface, improving the air permeability of the insole.

[0026] 4. The uniform brushing of Component A on the insole precursor and the introduction of a free radical polymerization and crosslinking system are both aqueous solution systems, without volatile organic gases, greatly improving the environmental protection and safety of the processing process.

[0027] 5. Through a systematic process step, from raw material preparation to the production of finished insoles, each step has been optimized in detail. For example, when preparing Component A, antibacterial agents, deodorants, pore-forming agents, and hardening agents are added to ensure the multifunctionality and excellent performance of the insole material. The uniformity of the foam and the overall quality of the insole are improved by pouring into a mold.

[0028] The present invention will be further described below. Detailed implementation mode

[0029] This specific embodiment is only an interpretation of the present invention and is not a limitation of the present invention. Those skilled in the art can make modifications without creative contributions to this embodiment according to needs after reading this specification, but as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

[0030] A typical method for preparing a boneless insole is as follows:

[0031] S1. Mix polyether polyol, polyester polyol, surfactant, catalyst, compatibilizer, polymerization monomer, and crosslinking monomer and put them into Container A for stirring. After heating and stirring, Component A is obtained. The heating temperature is controlled at 40 - 60 °C, the rotation speed is 50 - 80 revolutions per minute, and the stirring time is 1 - 1.5 hours;

[0032] S2. Put diphenylmethane diisocyanate into Container B and heat it to obtain Component B, where the heating temperature is 40 - 50 °C;

[0033] S3. Mix Component A and Component B obtained in steps S1 and S2 evenly to obtain a base material mixed component;

[0034] S4. Pour the base material mixed component obtained in step S3 into a mold and let it foam spontaneously to obtain a polyurethane insole;

[0035] S5. Open the mold, evenly brush Component A on the insole precursor, then close the mold and add an initiator solvent aqueous solution, and then heat and cure for 30 - 40 min. The heating temperature is controlled at 50 - 70 °C; a boneless insole is obtained.

[0036] By mixing polyether polyol, polyester polyol, surfactant, catalyst, compatibilizer, polymerization monomer, and crosslinking monomer and putting them into container A for stirring, and obtaining polyol mixture component A through heating and stirring, the above is a preparation method of a boneless insole. Among them, polyether polyol is used to improve the elasticity and comfort of the insole; the polymerization monomer and crosslinking monomer do not react in steps S1 to S4, but in S5, after adding an initiator and certain temperature and time conditions, they can assist in forming a dense three-dimensional network structure on the surface, restricting the movement of polymer chains, thereby improving the wear resistance of the insole. Polyester polyol mainly acts as an adhesive to bond various materials of the insole together, improving the integrity and stability of the insole. The surfactant mainly plays the role of wetting and emulsifying during the insole forming process, can reduce the interfacial tension, increase the wettability of the interface, thereby improving the adhesion and permeability of the coating. The catalyst plays the role of promoting chemical reactions during the insole forming process, can accelerate the crosslinking reaction between polymer molecules, and promote the curing and forming of materials; by mixing diphenylmethane diisocyanate and putting it into container B for stirring, and obtaining component B through heating and stirring. When diphenylmethane diisocyanate is formed, by reacting with components such as polyester polyol and polyether polyol, the crosslinking density of the insole material can be increased. Then, the obtained insole precursor is evenly brushed with component A and heated, and at the same time, an initiator solvent aqueous solution is added. Through the secondary reaction of polyester polyol, polyether polyol, etc. with diphenylmethane diisocyanate, and free radical polymerization and crosslinking on the surface, a dense wear-resistant layer is formed. In addition, this secondary reaction and free radical polymerization and crosslinking are significantly different from the painting process in CN118063734A. This surface layer material does not reduce the surface wear resistance, while maintaining the porosity of the polyurethane insole surface, effectively improving the breathability of the boneless insole.

[0037] Example 1:

[0038] S1. Mix polyether polyol, polyester polyol, surfactant, catalyst, compatibilizer, polymerization monomer, and crosslinking monomer and put them into container A for stirring, and obtain component A through heating and stirring. The heating temperature is controlled at 40°C, the rotation speed is 50 revolutions per minute, and the stirring time is 1 hour;

[0039] S2. Put diphenylmethane diisocyanate into container B, and obtain component B through heating, where the heating temperature is 40°C;

[0040] S3. Mix component A and component B obtained in steps S1 and S2 evenly to obtain a base material mixture component;

[0041] S4. Pour the base material mixture component obtained in step S3 into a mold, and obtain a polyurethane insole through self-foaming;

[0042] S5. Open the mold, evenly brush component A on the front body of the insole, add an initiator aqueous solution with a concentration of 1%, then close the mold, and then heat and cure for 30 minutes at a heating temperature controlled at 50°C to obtain a boneless insole.

[0043] Example 2:

[0044] S1. Put polyether polyol, polyester polyol, surfactant, catalyst, compatibilizer, polymerization monomer, and crosslinking monomer into container A and stir. After heating and stirring, component A is obtained. The heating temperature is controlled at 50°C, the rotation speed is 65 revolutions per minute, and the stirring time is 1 hour;

[0045] S2. Put diphenylmethane diisocyanate into container B and heat it to obtain component B, where the heating temperature is 45°C;

[0046] S3. Mix component A and component B obtained in steps S1 and S2 evenly to obtain a base material mixed component;

[0047] S4. Pour the base material mixed component obtained in step S3 into the mold and let it foam spontaneously to obtain a polyurethane insole;

[0048] S5. Open the mold, evenly brush component A on the front body of the insole, add an initiator aqueous solution with a concentration of 1.5%, then close the mold, and then heat and cure for 35 minutes at a heating temperature controlled at 60°C to obtain a boneless insole.

[0049] Example 3:

[0050] S1. Put polyether polyol, polyester polyol, surfactant, catalyst, compatibilizer, polymerization monomer, and crosslinking monomer into container A and stir. After heating and stirring, component A is obtained. The heating temperature is controlled at 60°C, the rotation speed is 80 revolutions per minute, and the stirring time is 1.5 hours;

[0051] S2. Put diphenylmethane diisocyanate into container B and mix it. After heating and stirring, component B is obtained, where the heating temperature is 50°C;

[0052] S3. Mix component A and component B obtained in steps S1 and S2 evenly to obtain a base material mixed component;

[0053] S4. Pour the base material mixed component obtained in step S3 into the mold and let it foam spontaneously to obtain a polyurethane insole;

[0054] S5. Open the mold, evenly brush component A on the front body of the insole, add an initiator solvent aqueous solution with a concentration of 2%, then close the mold, and then heat and cure for 40 minutes at a heating temperature controlled at 70°C to obtain a boneless insole.

[0055] This test method has simple operation steps, and at the same time does not generate excess organic waste gas, with higher safety and environmental protection performance.

[0056] The performance of the boneless polyurethane antibacterial and deodorant insoles obtained in Examples 1-3 was tested.

[0057] 1. Reference standard for deodorant performance test: GB / T 33610.2-2017 "Determination of deodorant performance of textiles - Part 2: Detecting tube method"

[0058] Test method: Place the insole in a sampling bag and contact it with a certain amount of odor gas for a period of time; use the sampling bag in contact with the odor gas as a blank control; use a detecting tube to measure the odor concentration in the container with an odor detector to determine the reduction rate of the odor component concentration.

[0059] 2. Reference standard for abrasion resistance test: GB / T 21196.3-2007: Determination of mass loss

[0060] Test method: Use an abrasion resistance testing machine, place the insole on the test bench, and apply a certain pressure and friction force for cyclic friction testing.

[0061] 3. Reference standard for air permeability test: GB / T 5453-1997 Determination of air permeability of textiles

[0062] Test method: Use an air permeability tester, place the insole in the test device, and measure the air flow rate passing through the insole per unit time.

[0063] 4. Reference standard for antibacterial performance test: GB / T 2881-2013 Technical conditions for antibacterial performance of footwear and footwear components

[0064] Test method: The absorption method is used to test the antibacterial performance of the antibacterial sample and the non-antibacterial sample, and the plate coating method is used to determine the number of colonies, so as to calculate the antibacterial rate.

[0065]

[0066] Comparative Example 1:

[0067] S1. Mix polyether polyol, polyester polyol, surfactant, catalyst, compatibilizer, polymerization monomer, and crosslinking monomer and put them into container A for stirring. After heating and stirring, component A is obtained. The heating temperature is controlled at 40, the rotation speed is 50 revolutions per minute, and the stirring time is 1 hour;

[0068] S2. Put diphenylmethane diisocyanate into container B and heat it to obtain component B, where the heating temperature is 40;

[0069] S3. Mix the component A and component B obtained in steps S1 and S2 evenly to obtain the base material mixed component;

[0070] S4. Pour the base material mixture component obtained in step S3 into a mold and let it foam spontaneously to obtain a polyurethane insole.

[0071] S5. Open the mold and evenly apply a paint layer on the insole precursor.

[0072] Comparative Example 2:

[0073] S1. Mix polyether polyol, polyester polyol, surfactant, catalyst, compatibilizer, polymerization monomer, and crosslinking monomer and put them into container A for stirring. After heating and stirring, component A is obtained. The heating temperature is controlled at 50 °C, the rotation speed is 65 revolutions per minute, and the stirring time is 1 hour.

[0074] S2. Put diphenylmethane diisocyanate into container B and heat it to obtain component B, where the heating temperature is 45 °C.

[0075] S3. Mix component A and component B obtained in steps S1 and S2 evenly to obtain a base material mixture component.

[0076] S4. Pour the base material mixture component obtained in step S3 into a mold and let it foam spontaneously to obtain a polyurethane insole.

[0077] S5. Open the mold and evenly apply a paint layer on the insole precursor.

[0078] Comparative Example 3:

[0079] S1. Mix polyether polyol, polyester polyol, surfactant, catalyst, compatibilizer, polymerization monomer, and crosslinking monomer and put them into container A for stirring. After heating and stirring, component A is obtained. The heating temperature is controlled at 60 °C, the rotation speed is 80 revolutions per minute, and the stirring time is 1.5 hours.

[0080] S2. Put diphenylmethane diisocyanate into container B and heat it to obtain component B, where the heating temperature is 50 °C.

[0081] S3. Mix component A and component B obtained in steps S1 and S2 evenly to obtain a base material mixture component.

[0082] S4. Pour the base material mixture component obtained in step S3 into a mold and let it foam spontaneously to obtain a polyurethane insole.

[0083] S5. Open the mold and evenly apply a paint layer on the insole precursor.

[0084] Test data of directly applying paint on the insole

[0085]

[0086] Beneficial effects:

[0087] By performing a secondary reaction on the surface of free radical polymerization to form a dense wear-resistant layer, compared with the insole directly painted with paint, it can still maintain excellent wear resistance; but more importantly, the coating method in the present invention can maintain a higher porosity on the surface than the paint method, thereby improving the air permeability of the insole; and based on the improvement of the air permeability, it can improve the absorption efficiency of the insole for odor in the anti-odor test, thereby achieving better anti-odor performance.

Claims

1. A method for preparing a boneless insole, characterized in that: The steps include: S1. Put polyether polyol, polyester polyol, surfactant, catalyst, compatibilizer, polymerization monomer and cross-linking monomer into container A and mix them, and obtain component A by heating and stirring. The heating temperature is controlled at 40-60° C., the rotation speed is 50-80 rpm, and the stirring time is 1-1.5 hours; S2, adding diphenylmethane diisocyanate into container B, and heating to obtain component B, wherein the heating temperature is 40-50°C; S3, uniformly mixing component A and component B obtained in steps S1 and S2 to obtain a substrate mixed component; S4, pouring the mixed components of the base material obtained in step S3 into a mold, and subjecting it to self-foaming to obtain a polyurethane insole; S5. Open the mold, evenly apply component A on the insole precursor, add the initiator aqueous solution, close the mold, heat and mature for 30-40 minutes, and control the heating temperature at 50-70° C. to obtain a boneless insole.

2. The method for preparing a boneless insole according to claim 1, characterized in that: The polymerizable monomers include methyl methacrylate, butyl acrylate, and dodecyl methacrylate.

3. The method for preparing a boneless insole according to claim 1, characterized in that: The cross-linking monomers include diacetone acrylamide and acetoacetoxyethyl methacrylate.

4. The method for preparing a boneless insole according to claim 1, characterized in that: The initiator includes ammonium persulfate, potassium persulfate, and azobiscyanovaleric acid.

5. The method for preparing a boneless insole according to claim 1, characterized in that: The concentration of the initiator aqueous solution is 0.1-2%.

6. The method for preparing a boneless insole according to claim 1, characterized in that: When preparing component A in step S1, the process also includes adding an antibacterial agent and a deodorant into container A and stirring the container at the same time.

7. The method for preparing a boneless insole according to claim 1, characterized in that: When preparing component A in step S1, the step also includes adding a pore opening agent and a hardening agent into container A and stirring them simultaneously.

Images