Polyurethane sponge for shoe material and method for preparing the same

Abstract

The application relates to the technical field of polyurethane sponges, in particular to a polyurethane sponge for shoe materials and a preparation method thereof, the polyurethane sponge for shoe materials comprises the following raw materials in percentage by weight: a foaming agent 0.5-0.7%, toluene diisocyanate 14-16%, silicon oil 0.5-0.7%, triethylene diamine 0.4-0.6%, a tin catalyst 0.08-0.12%, an antibacterial agent 0.8-0.12%, a dispersing agent 3-5%, and the balance is polyether polyol; the antibacterial agent is prepared by the reaction of polyhexamethylene guanidine hydrochloride and a carboxyl-terminated hyperbranched polyester, and then the reaction with zinc ions and calcium ions; the polyurethane sponge has the advantages of improved antibacterial property.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of polyurethane sponge, in particular to a polyurethane sponge for shoe materials and a preparation method thereof. BACKGROUND

[0002] The polyurethane material is a polymer containing urethane groups in a macromolecular backbone, and the polyurethane sponge prepared by foaming the polyurethane material has good resilience, air permeability, mechanical properties, corrosion resistance and flame retardance. Based on the excellent performance of the polyurethane sponge, the polyurethane sponge can be widely applied to industrial production and daily life, such as packaging materials, seats, shoe materials and the like.

[0003] For shoe materials, the polyurethane sponge is commonly used for insoles, upper materials and the like. Based on the improvement of living standards, people gradually improve the requirements for shoe materials, and require the shoe material sponge to have softness, resilience, air permeability and the like. However, the shoe material sponge on the market does not have antibacterial ability, which is not conducive to foot health. SUMMARY

[0004] In order to make the shoe material sponge have antibacterial property, the application provides a polyurethane sponge for shoe materials and a preparation method thereof.

[0005] In a first aspect, the application provides a polyurethane sponge for shoe materials, which adopts the following technical scheme:

[0006] The polyurethane sponge for shoe materials comprises the following raw materials in weight percentage: 0.5-0.7% of a foaming agent, 14-16% of toluene diisocyanate, 0.5-0.7% of silicone oil, 0.4-0.6% of triethylene diamine, 0.08-0.12% of a tin catalyst, 0.8-1.2% of an antibacterial agent and 3-5% of a dispersing agent; and the balance is polyether polyol.

[0007] The antibacterial agent is prepared by the reaction of polyhexamethylene guanidine hydrochloride and carboxyl-terminated hyperbranched polyester, and then the reaction with zinc ions and calcium ions.

[0008] By adopting the technical scheme, the antibacterial agent molecule contains polyhexamethylene guanidine hydrochloride unit and zinc ion metal active center, both of which have antibacterial effect, and the combination of the two can improve the antibacterial capacity of the antibacterial agent. Moreover, the hyperbranched molecule is added to the structure of the antibacterial agent. Due to the large steric hindrance of the molecular structure of the hyperbranched molecule, after the coordination reaction of the hyperbranched molecule with zinc ions and calcium ions, the antibacterial agent has more molecular defects and more active metal active center reaction sites. The molecules of sodium alginate in the dispersant are connected by (1→4) bonds of β-D-mannuronic acid (β-D-mannuronic, M) and α-L-guluronic acid (α-L-guluronic, G). Sodium alginate can quickly form a gel under extremely mild conditions. The calcium ion metal center in the antibacterial agent can undergo ion exchange reaction with the sodium ion on the G unit of sodium alginate, and the G unit is stacked to form a cross-linked network gel structure. Microcrystalline cellulose and sodium cellulose as dispersants can enhance the dispersibility of the antibacterial agent, and the intermolecular hydrogen bonds can be formed between the microcrystalline cellulose, sodium cellulose and sodium alginate, which can anchor the antibacterial agent. Therefore, under the condition that the three raw materials of the dispersant exist at the same time, the anchoring effect on the antibacterial agent can be enhanced, and the antibacterial washing resistance of the polyurethane sponge is stronger.

[0009] As preferred: the polyurethane sponge includes the following raw materials by weight percentage: foaming agent 0.6%, toluene diisocyanate 15%, silicone oil 0.6%, triethylene diamine 0.5%, tin catalyst 0.1%, antibacterial agent 1%, dispersant 4%; the balance is polyether polyol.

[0010] By adopting the above technical scheme, by further optimizing the ratio of each raw material of the polyurethane sponge, the comprehensive performance of the polyurethane sponge can be further improved.

[0011] As preferred: the preparation method of the antibacterial agent is as follows:

[0012] S1, in 30-40 parts by weight of deionized water, 8-12 parts by weight of carboxyl-terminated hyperbranched polyester and 1.8-2.5 parts by weight of polyhexamethylene guanidine hydrochloride are added, stirred until dissolved, the pH is adjusted to 9-10, and the temperature is raised to 50-60℃, and stirred for 20-24h; S2, continue to add 0.7-1.0 parts by weight of zinc nitrate and 0.3-0.6 parts by weight of calcium nitrate, stir until dissolved, then raise the temperature to 60-70℃, and stir for 16-20h to obtain the antibacterial agent.

[0013] By adopting the above technical scheme, by condensation reaction of polyhexamethylene guanidine hydrochloride and carboxyl-terminated hyperbranched polyester to form a ligand, and then coordination reaction with zinc ions and calcium ions, a metal organic framework material is prepared, which is used as an antibacterial agent.

[0014] As preferred: the pH in S1 is adjusted by sodium hydroxide or potassium hydroxide.

[0015] By adopting the above technical solution, the two substances can adjust the pH without affecting the reaction system and forming impurities.

[0016] As preferred: the tin catalyst is one or both of stannous octoate and dibutyltin dilaurate.

[0017] By adopting the above technical solution, both of the two tin catalysts are raw materials commonly used for polyurethane sponge and are suitable for the foaming system of the present application.

[0018] As preferred: the dispersant includes the following raw materials by weight: 3-5 parts by weight of microcrystalline cellulose, 4-6 parts of sodium alginate, and 1-3 parts of sodium cellulose.

[0019] By adopting the above technical solution, sodium alginate can quickly form a gel under extremely mild conditions, and the calcium ion metal center in the antibacterial agent can undergo an ion exchange reaction with the sodium ions on the G unit of sodium alginate, and the G unit is stacked to form a cross-linked network gel structure. Microcrystalline cellulose and sodium cellulose as a dispersant can enhance the dispersibility of the antibacterial agent, and intermolecular hydrogen bonds can be formed between microcrystalline cellulose, sodium cellulose, and sodium alginate, which can anchor the antibacterial agent. The three substances have a synergistic effect, which can enhance the anchoring effect of the antibacterial agent and make the antibacterial resistance of the polyurethane sponge stronger.

[0020] As preferred: the polyurethane sponge further adds ≤3% of color paste.

[0021] In a second aspect, the present application provides a preparation method of polyurethane sponge for shoe materials, which adopts the following technical solution: a preparation method of polyurethane sponge for shoe materials, which includes the following preparation steps:

[0022] S1, according to the weight fraction of each raw material, polyether polyol, foaming agent, silicone oil, tin catalyst of triethylenediamine, and antibacterial agent are stirred and mixed, the stirring and mixing temperature is 20-35℃, and a first reaction liquid is obtained;

[0023] S2, toluene diisocyanate is added to the first reaction liquid, and after stirring and reaction, the stirring and reaction temperature is 20-40℃, and it is placed in a mold for curing and cooling, to obtain polyurethane sponge for shoe materials.

[0024] By adopting the above technical solution, the preparation method of the present application does not have special requirements for equipment and has a larger tolerance range for process parameters, which is suitable for mass production.

[0025] In summary, the present application includes at least one of the following beneficial technical effects:

[0026] 1、In the application, the antibacterial agent molecule contains polyhexamethylene guanidine hydrochloride unit and zinc ion metal active center, both of which have antibacterial effect, and the combination of the two can improve the antibacterial ability of the antibacterial agent. And adding hyperbranched molecules in the structure of the antibacterial agent, because the molecular structure of the hyperbranched molecules has a large steric effect, after the coordination reaction of the hyperbranched molecules with zinc ions and calcium ions, the antibacterial agent formed has more molecular defects and more active metal active center reaction sites. The molecules of sodium alginate in the dispersant are connected by (1→4) bonds of β-D-mannuronic acid (β-D-mannuronic, M) and α-L-guluronic acid (α-L-guluronic, G). Sodium alginate can quickly form a gel under very mild conditions, and the calcium ion metal center in the antibacterial agent can undergo ion exchange reaction with the sodium ion on the G unit of sodium alginate, and the G unit is stacked to form a cross-linked network gel structure. Microcrystalline cellulose and sodium cellulose as dispersants can enhance the dispersibility of the antibacterial agent, and intermolecular hydrogen bonds can be formed between microcrystalline cellulose, sodium cellulose and sodium alginate, which can anchor the antibacterial agent, so that the anchoring effect of the antibacterial agent is enhanced when the three raw materials of the dispersant exist at the same time, and the antibacterial resistance of the polyurethane sponge is stronger.

[0027] 2、The polyurethane sponge prepared in the application has excellent antibacterial performance, and the antibacterial rate of Escherichia coli is greater than 98.2%, which can reach 99.8%, and after washing for 50 times, it can still reach 97.9% and above; the antibacterial rate of Staphylococcus aureus is greater than 98.6%, which can reach 99.9%, and after washing for 50 times, it can still reach 98.1% and above; and the tensile strength of the polyurethane of the application is greater than 132Kpa. It is proved that the polyurethane sponge of the application has good mechanical properties and excellent antibacterial performance. DETAILED DESCRIPTION

[0028] The application will be further described in detail in combination with specific content.

[0029] Raw materials

[0030] In the raw materials used in the examples of the application, the average molecular weight of the carboxyl-terminated hyperbranched polyester is 1000; the average molecular weight of polyhexamethylene guanidine hydrochloride is 220; the type of polyether polyol is DL-1000D; the type of silicone oil is L595; and the rest of the raw materials are ordinary commercially available products.

[0031] Preparation example

[0032] Preparation example 1

[0033] An antibacterial agent is prepared by the following method:

[0034] S1. Add 10g of carboxyl-terminated hyperbranched polyester and 2.1g of polyhexamethylene guanidine hydrochloride to 35g of deionized water, stir until dissolved, adjust the pH to 9 with sodium hydroxide, raise the temperature to 55℃, and stir for 24h.

[0035] S2. Continue to add 0.8g of zinc nitrate and 0.5g of calcium nitrate, stir until dissolved, heat to 65℃, and stir for 20h to obtain the antibacterial agent.

[0036] Preparation Example 2

[0037] A dispersant, the preparation method of which is as follows:

[0038] 4 kg of microcrystalline cellulose, 5 kg of sodium alginate and 2 kg of sodium cellulose were mixed to obtain a dispersant.

[0039] Example

[0040] Example 1

[0041] A polyurethane foam for footwear materials, the raw materials and their amounts are shown in Table 1, and its preparation method is as follows:

[0042] S1. According to the weight proportions of each raw material, the polyether polyol, foaming agent, silicone oil, triethylenediamine tin catalyst and antibacterial agent are stirred and mixed at a temperature of 35°C to obtain the first reaction solution.

[0043] S2. Toluene diisocyanate is added to the first reaction solution, and after stirring and reacting, the stirring temperature is 40°C. The solution is then placed in a mold for curing and cooling to obtain polyurethane foam for shoe materials.

[0044] The foaming agent was water; the tin catalyst was stannous octoate; the antibacterial agent was from Preparation Example 1; and the dispersant was from Preparation Example 2.

[0045] Table 1. Raw materials and dosage (kg) for Examples 1-3

[0046] Example 1 Example 2 Example 3 Polyether polyol 78.52 79.4 80.28 Blowing agent 0.5 0.6 0.7 Toluene diisocyanate 16 15 14 Silicone oil 0.5 0.6 0.7 Triethylene diamine 0.6 0.5 0.4 Tin catalyst 0.08 0.1 0.12 Antibacterial agent 0.8 0.8 0.8 Dispersant 3 3 3

[0047] Example 4

[0048] A polyurethane foam for shoe materials differs from Example 2 in that the amount of dispersant added is 4 kg, the amount of polyether polyol added is 78.4 kg, and the remaining steps are the same as in Example 2.

[0049] Example 5

[0050] A polyurethane foam for shoe materials differs from Example 2 in that the amount of dispersant added is 5 kg, the amount of polyether polyol added is 77.4 kg, and the remaining steps are the same as in Example 2.

[0051] Example 6

[0052] A polyurethane foam for shoe materials differs from Example 4 in that the amount of antibacterial agent added is 1 kg, the amount of polyether polyol added is 78.2 kg, and the remaining steps are the same as in Example 2.

[0053] Example 7

[0054] A polyurethane foam for shoe materials differs from Example 4 in that the amount of antibacterial agent added is 1.2 kg, the amount of polyether polyol added is 78 kg, and the remaining steps are the same as in Example 2.

[0055] Example 8

[0056] A polyurethane foam for shoe materials differs from Example 2 in that its raw materials also include 2 kg of color paste and 77.4 kg of polyether polyol, while the remaining steps are the same as in Example 2.

[0057] Comparative Example

[0058] Comparative Example 1

[0059] A polyurethane foam for footwear materials differs from Example 2 in that the dispersant is replaced with an equal amount of polyether polyol, while the remaining steps are the same as in Example 2.

[0060] Comparative Example 2

[0061] A polyurethane foam for footwear materials differs from Example 2 in that sodium alginate is not added to its dispersant, while the remaining steps are the same as in Example 2.

[0062] Comparative Example 3

[0063] A polyurethane foam for footwear materials differs from Example 2 in that it does not contain microcrystalline cellulose in its dispersant, while the remaining steps are the same as in Example 2.

[0064] Comparative Example 4

[0065] A polyurethane foam for footwear materials differs from Example 2 in that sodium cellulose is not added as a dispersant, while the remaining steps are the same as in Example 2.

[0066] Comparative Example 5

[0067] A polyurethane foam for footwear differs from Example 2 in that, during the preparation of its antibacterial agent, the added calcium nitrate is replaced with an equal amount of zinc nitrate, while the remaining steps are the same as in Example 2.

[0068] Performance testing test methods / test methods

[0069] Polyurethane foams were prepared according to Examples 1-8 and Comparative Examples 1-5, and then tested according to the following testing methods. The test results are shown in Table 2.

[0070] Tensile strength: Tested according to the test method in GB / T 6344;

[0071] Antibacterial rate: Tested according to the test method in GB / T 20944.3.

[0072] Table 2 shows the test results of Examples 1-8 and Comparative Examples 1-5.

[0073]

[0074] As can be seen from Examples 1-7, Comparative Examples 1-5, and the test data in Table 2, the polyurethane sponge prepared in this application exhibits excellent antibacterial properties. Its antibacterial rate against *Escherichia coli* is greater than 98.2%, reaching 99.8%, and even after 50 washes, it still maintains a rate of 97.9% or higher. Its antibacterial rate against *Staphylococcus aureus* is greater than 98.6%, reaching a maximum of 99.9%, and even after 50 washes, it still maintains a rate of 98.1% or higher. Furthermore, the tensile strength of the polyurethane in this application is 132 kPa or higher. This demonstrates that the polyurethane sponge of this application possesses both good mechanical properties and excellent antibacterial performance.

[0075] The test data from Examples 2 and 4-5 show that, when the content of the antibacterial agent added to the polyurethane sponge of this application is constant, gradually increasing the content of the dispersant gradually improves the antibacterial properties of the polyurethane sponge, and also gradually improves the wash resistance of the antibacterial properties of the polyurethane sponge. Combined with Comparative Examples 1-5, the sodium alginate molecule in the dispersant is composed of β-D-mannuronic acid (M) and α-L-guluronic acid (G) linked by (1→4) bonds. Sodium alginate can rapidly form a gel under extremely mild conditions. The calcium ion metal center in the antibacterial agent can undergo an ion exchange reaction with the sodium ions on the G units of sodium alginate, and the G units stack to form a cross-linked network gel structure. Microcrystalline cellulose and sodium cellulose, as dispersants, can enhance the dispersibility of antibacterial agents. Furthermore, intermolecular hydrogen bonds can form between microcrystalline cellulose, sodium cellulose, and sodium alginate, anchoring the antibacterial agent. Therefore, the simultaneous presence of these three dispersant ingredients enhances the anchoring effect on the antibacterial agent, resulting in stronger antibacterial and wash-resistant properties of the polyurethane foam. However, increasing the amount of dispersant added has a certain impact on the foaming reaction of the polyurethane foam system, leading to a decrease in the tensile strength of the polyurethane foam.

[0076] Through Examples 2 and 6-7, it was found that when the amount of dispersant added is constant, the antibacterial rate of polyurethane sponge increases as the amount of antibacterial agent added gradually increases; however, the tensile strength of polyurethane sponge decreases.

[0077] The embodiments described above are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A polyurethane foam for footwear materials, characterized in that: It comprises the following raw materials in weight percentages: foaming agent 0.5-0.7%, toluene diisocyanate 14-16%, silicone oil 0.5-0.7%, triethylenediamine 0.4-0.6%, tin catalyst 0.08-0.12%, antibacterial agent 0.8-1.2%, dispersant 3-5%; the balance is polyether polyol; The antibacterial agent is prepared by reacting polyhexamethylene guanidine hydrochloride and carboxyl-terminated hyperbranched polyester, followed by reaction with zinc ions and calcium ions. The preparation method of the antibacterial agent is as follows: S1. Add 8-12 parts by weight of carboxyl-terminated hyperbranched polyester and 1.8-2.5 parts by weight of polyhexamethylene guanidine hydrochloride to 30-40 parts by weight of deionized water, stir until dissolved, adjust the pH to 9-10, raise the temperature to 50-60℃, and stir for 20-24 hours. S2. Continue to add 0.7-1.0 parts by weight of zinc nitrate and 0.3-0.6 parts by weight of calcium nitrate, stir until dissolved, heat to 60-70℃, stir and react for 16-20 hours to obtain the antibacterial agent; The dispersant comprises the following raw materials in parts by weight: 3-5 parts by weight of microcrystalline cellulose, 4-6 parts by weight of sodium alginate and 1-3 parts by weight of sodium cellulose.

2. The polyurethane foam for shoe materials according to claim 1, characterized in that: The polyurethane foam comprises the following raw materials in weight percentages: 0.6% foaming agent, 15% toluene diisocyanate, 0.6% silicone oil, 0.5% triethylenediamine, 0.1% tin catalyst, 1% antibacterial agent, and 4% dispersant; the balance is polyether polyol.

3. The polyurethane foam for shoe materials according to claim 1, characterized in that: The pH in S1 is adjusted by sodium hydroxide or potassium hydroxide.

4. The polyurethane foam for shoe materials according to claim 1, characterized in that: The tin catalyst is one or both of stannous octoate and dibutyltin dilaurate.

5. The polyurethane foam for shoe materials according to claim 1, characterized in that: The polyurethane foam also contains ≤3% colorant.

6. A method for preparing a polyurethane foam for shoe materials according to any one of claims 1-5, characterized in that: It includes the following preparation steps: S1. According to the weight proportions of each raw material, stir and mix the polyether polyol, foaming agent, silicone oil, triethylenediamine tin catalyst and antibacterial agent. The stirring temperature is 20-35℃ to obtain the first reaction solution. S2. Add toluene diisocyanate to the first reaction solution, stir and react. The stirring temperature is 20-40℃. Place it in a mold for curing and cooling to obtain polyurethane foam for shoe materials.

Images