Foaming polyurethane material and ultralight high-elastic insole

Abstract

The invention provides a foamed polyurethane material and an ultralight high-elastic insole, and relates to the technical field of shoe materials. The foamed polyurethane material is prepared from a component A and a component B, the component A comprises polyether glycol, a chain extender, a cross-linking agent, a surfactant, a catalyst and water, and the component B is a polyisocyanate monomer. According to the invention, the cross-linking agent is added into the foaming polyurethane material, and the composition of the polyether glycol and the surfactant is optimized, so that the low-density polyurethane foaming material can be obtained and used for preparing ultralight high-elastic insoles.

Description

Technical Field

[0001] The invention belongs to the technical field of shoe materials and relates to a foamed polyurethane material and an ultra-light and highly elastic insole. Background Art

[0002] With the continuous development of sports shoe technology, ultra-light and highly elastic soles have also become the choice of many sports shoes, such as the use of supercritical foaming TPU as the midsole material. There is a similar demand for insoles. The production process of polyurethane insoles rarely uses supercritical foaming. Generally, chemical foaming and infusion processes are used. For example, raw materials composed of polyether diols, chain extenders, cross-linking agents, catalysts, water, isocyanate monomers, etc., foaming and curing reactions occur under appropriate conditions (such as pouring into a mold, reacting at 50-60°C for 3-6 minutes). Chinese patent CN114763433A discloses a low-density polyurethane microporous foam composition, which uses a polyol with better physical strength and lower Tg and gas-phase silica or its suspension to improve the pore opening, solving the problem that the low-density foam surface is easy to shrink and the physical properties are insufficient, but the density of the obtained polyurethane foam is still basically 0.3g / cm 3 To achieve ultra-lightweight polyurethane insoles, the key technology is to increase the foaming ratio and foaming uniformity. However, increasing the foaming ratio may cause the cells to shrink, resulting in a lower foaming ratio and failure to achieve ultra-light and highly elastic insoles.

[0003] Therefore, in order to obtain ultra-light and high-elastic insoles, it is necessary to improve the foaming uniformity and cell strength while increasing the foaming ratio. Especially when the density of the polyurethane sole is as low as 0.15g / cm 3 , or even lower (such as 0.1g / cm 3 ), this situation faces challenges. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a foamed polyurethane material and an ultra-light and high-elastic insole.

[0005] The technical solutions of the present invention are as follows:

[0006] A foamed polyurethane material is prepared from component A and component B;

[0007] The raw material components of the A component include polyether diol, chain extender, cross-linking agent, surfactant, catalyst and water;

[0008] The chain extender is selected from C2-C8 alkyl glycol;

[0009] The structure of the cross-linking agent is shown in the following formula (1):

[0010] HOR 1 NHR2 OH(1)

[0011] Among them, R 1 and R 2 independently selected from C1-C6 alkylene;

[0012] The B component is a polyisocyanate monomer.

[0013] Preferably, the polyether diol is composed of polypropylene glycol and polytetramethylene glycol in a weight ratio of 1:1-10:1, and the number average molecular weight of the polyether diol is 500-2000.

[0014] Preferably, the surfactant is selected from polyether modified silicone oil and / or amino silicone oil.

[0015] More preferably, the amino silicone oil has an ammonia value of 0.2-2 mmol / g.

[0016] More preferably, the structure of the amino silicone oil is as shown in the following formula (2):

[0017] R 3 Me2SiO(SiOMe2) a (SiOMeR 4 ) b (SiOMeR 5 ) c SiMe2R 3 (2)

[0018] Among them, R 3 is selected from C1-C4 alkyl, R 4 The structure is -(CH2)3(NHCH2CH2) d NH2, R 5 The structure is -(CH2)3(NHCH2CH2) e NHCOR 6 , R 6 Selected from C1-C4 alkyl, Me is methyl, a≥0, b>0, c>0, 0.05≤c / (a+b+c)≤0.3, 10≤a+b+c≤200, d=0-1, e=0-1.

[0019] Preferably, the catalyst is selected from triethylenediamine or a combination of triethylenediamine and bis(2-dimethylaminoethyl)ether.

[0020] Preferably, the polyisocyanate monomer is selected from diisocyanate monomers;

[0021] Preferably, the isocyanate monomer is selected from MDI.

[0022] Preferably, the molar ratio of active hydrogen in the A component to NCO groups in the B component is 1:1.15-1.25.

[0023] Preferably, the weight proportion of the polyether diol in the raw material components of component A is 70-90%;

[0024] The weight proportion of the chain extender in the raw material components of component A is 3-8%;

[0025] The weight proportion of the cross-linking agent in the raw material components of component A is 0.3-1.5%;

[0026] The surfactant accounts for 0.5-2% by weight of the raw material components of component A;

[0027] The weight proportion of the catalyst in the raw material components of component A is 0.5-2.5%;

[0028] The weight proportion of water in the raw material components of component A is 3-5%.

[0029] An ultra-light and highly elastic insole is prepared from the foamed polyurethane material described in any one of the above embodiments.

[0030] The beneficial effects of the present invention are as follows: in order to improve the uniformity of the pores and the pore strength under high foaming performance, thereby obtaining a low-density foamed polyurethane material, the present invention adopts the following design ideas: (1) more hydrogen bonds are introduced into the polyurethane, for example, the cross-linking agent contains a tertiary amine group and the surfactant contains amino silicone oil, which can form more hydrogen bonds after participating in the cross-linking reaction; (2) the polyether diol contains polytetramethylene ether diol, which can further improve the pore strength and improve the mechanical properties of the foamed polyurethane. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is the appearance of the insole obtained in Example 1.

[0032] Figure 2 This is the appearance of the insole obtained in Comparative Example 1. DETAILED DESCRIPTION

[0033] The technical solution of the present invention is further illustrated and described below through specific embodiments. On the one hand, the present invention provides a foamed polyurethane material prepared from component A and component B;

[0034] The raw material components of component A include polyether diol, chain extender, cross-linking agent, surfactant, catalyst and water;

[0035] The chain extender is selected from C2-C8 alkyl glycol;

[0036] The structure of the cross-linking agent is shown in the following formula (1):

[0037] HOR 1 NHR 2 OH(1)

[0038] Among them, R 1 and R 2 independently selected from C1-C6 alkylene;

[0039] Component B is a polyisocyanate monomer.

[0040] For polyurethane foam material, generally add a certain amount of water in raw material, utilize the reaction of water and NCO group to produce carbon dioxide and primary amino group, carbon dioxide plays the effect of whipping agent, primary amino group can continue to react with NCO group, increase the molecular weight of polyurethane, even cross-linking reaction can occur, improve cell wall strength.When needs realize the higher foaming ratio of polyurethane material, obtain the polyurethane foam material of lower density, need to add more water, this improves the reaction rate of water and NCO group, may cause abscess to be too large or uneven and shrink.In order to realize that polyurethane material still can obtain comparatively even and the abscess with higher intensity under higher foaming ratio, avoid foaming back abscess to produce shrinkage, the present invention adds cross-linking agent in the raw material of A component, contain three active hydrogens in the structure of cross-linking agent, wherein 1 active hydrogen is secondary amino group, cross-linking reaction is had to autocatalysis, can improve the reaction rate of cross-linking agent and NCO group, form competition with the reaction of water and NCO group, reduce the reaction rate of water and NCO group, avoid abscess to be too large or uneven. The cross-linking agent can further increase the cross-linking density of the pore wall and improve the mechanical strength. The cross-linking agent contains tertiary amine groups, which can form more hydrogen bonds in the structure of the pore wall, thereby further improving the mechanical strength and avoiding the generation of shrinkage holes when achieving a high foaming ratio.

[0041] Examples of chain extenders include 1,4-butanediol, 1,2-ethylene glycol, 1,5-pentanediol, and 1,6-hexanediol. Examples of crosslinkers include diethanolamine, dipropanolamine, dibutanolamine, and dihexanolamine.

[0042] In some embodiments, the polyether diol is composed of polypropylene glycol (PPG) and polytetramethylene glycol (PTMEG) in a weight ratio of 1:1-10:1, and the number average molecular weight of the polyether diol is 500-2000. In the present invention, the polyether diol contains some PTMEG, which can further improve the mechanical strength and elasticity of the polyurethane foam material. For example, the weight ratio of PPG and PTMEG diols can be any value among 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, etc., or any value in between, without particular limitation. The number average molecular weight of the polyether diol can be any value among 500, 600, 800, 1000, 1200, 1500, 1800, 2000, etc., or any value in between, without particular limitation. Those skilled in the art know that PPG with a number average molecular weight of 1000 can be recorded as PPG-1000, PTMEG with a number average molecular weight of 1000 can be recorded as PTMEG-1000, and so on.

[0043] In some embodiments, the surfactant is selected from polyether-modified silicone oil and / or amino silicone oil. Polyether-modified silicone oil is a commonly used foaming agent for polyurethane foaming materials and can be directly obtained from the market. The present invention unexpectedly discovered that the inclusion of amino silicone oil in the surfactant can further improve the mechanical strength and elasticity of the polyurethane foam while providing a better foaming effect. This may be due to several reasons, such as the flexible structure of the amino silicone oil, the ability of the amino group to participate in the cross-linking reaction, and the ability to form more hydrogen bonds.

[0044] The surfactant can be a single polyether-modified silicone oil, a single amino silicone oil, or a combination of polyether-modified silicone oil and amino silicone oil, such as a weight ratio of polyether-modified silicone oil to amino silicone oil of 5:1-1:1.

[0045] In some embodiments, the amino silicone oil has an ammonia value of 0.2-2 mmol / g. For example, the ammonia value can be any value among 0.2 mmol / g, 0.25 mmol / g, 0.3 mmol / g, 0.35 mmol / g, 0.4 mmol / g, 0.45 mmol / g, 0.5 mmol / g, 0.55 mmol / g, 0.6 mmol / g, 0.8 mmol / g, 0.9 mmol / g, 1 mmol / g, 1.2 mmol / g, 1.5 mmol / g, 1.8 mmol / g, 2 mmol / g, etc., or any value therebetween, without particular limitation. Further, the viscosity of the amino silicone oil at 25° C. can be 100-5000 mPa.s.

[0046] In some embodiments, the structure of amino silicone oil is shown in the following formula (2):

[0047] R 3Me2SiO(SiOMe2) a (SiOMeR 4 ) b (SiOMeR 5 ) c SiMe2R 3 (2)

[0048] Among them, R 3 is selected from C1-C4 alkyl, R 4 The structure is -(CH2)3(NHCH2CH2) d NH2, R 5 The structure is -(CH2)3(NHCH2CH2) e NHCOR 6 , R 6 Selected from C1-C4 alkyl, Me is methyl, a ≥ 0, b > 0, c > 0, 0.05 ≤ c / (a+b+c) ≤ 0.3, 10 ≤ a+b+c ≤ 200, d = 0-1, e = 0-1. The value of c / (a+b+c) is the molar ratio of amide groups in the amino silicone oil.

[0049] In the structure of the amino silicone oil shown in the above formula (2), the side chain contains an amide structure. The amide structure can form more hydrogen bonds in the polyurethane material and can further disperse the amino groups of the side chain to avoid the concentration of the amino groups. The amide group can also improve the compatibility of the amino silicone oil in component A to avoid the added amino silicone oil affecting the effect due to poor compatibility.

[0050] There is no particular restriction on the preparation method of the amino silicone oil shown in formula (2), and the preparation method can be the following: ① The corresponding cyclosiloxane monomer (such as octamethylcyclotetrasiloxane D4) and dialkoxysilane (such as 3-aminopropylmethyldimethoxysilane, acetylaminopropylmethyldimethoxysilane) are polymerized in the presence of a capping agent (such as decamethyltetrasiloxane) and a catalyst (such as siloxane tetramethylammonium hydroxide); ② It is obtained by hydrolysis and condensation of dichlorosilane (such as dimethyldichlorosilane, 3-aminopropylmethyldichlorosilane and acetylaminopropylmethyldichlorosilane) and trimethylchlorosilane in water; ③ It is obtained by condensation reaction of amino silicone oil containing primary amino groups in the side chain (such as c=0 in the above formula (2)) with acyl chloride (such as acetyl chloride, propionyl chloride) to remove HCl. Taking the above method ③ as an example, the specific preparation process can be as follows: the side amino silicone oil (in the above formula (2), R 5 With R 4The same) and the acid-binding agent triethylamine are added to an organic solvent (such as tetrahydrofuran), the reaction vessel is placed in an ice-water bath, and an acyl chloride solution (such as acetyl chloride solution, the molar number of acyl chloride can be 0.3-0.5 times the molar number of primary amino groups in the pendant amino silicone oil) is added dropwise. After the addition is complete, the reaction is continued for 1-12 hours, and then the temperature is raised to 20-25°C for reaction for 1-6 hours. The product is filtered and low-boiling substances are removed from the filtrate to obtain the product.

[0051] In some embodiments, the catalyst is selected from triethylenediamine or a combination of triethylenediamine and bis(2-dimethylaminoethyl)ether. Triethylenediamine is a very important tertiary amine catalyst in the production of flexible foam polyurethane. It can promote the reaction between isocyanate and water, i.e., the foaming reaction, and the reaction between hydroxyl groups and isocyanate, i.e., the gelling reaction.

[0052] In some embodiments, the polyisocyanate monomer is selected from diisocyanate monomers, such as MDI, IPDI, HMDI, TDI, etc.; further, the isocyanate monomer is selected from MDI. MDI is a diisocyanate monomer commonly used in preparing foamable polyurethane materials.

[0053] In some embodiments, the molar ratio of active hydrogen in component A to NCO groups in component B is 1:1.15-1.25. The above-mentioned active hydrogen includes H on the polyether hydroxyl group, H on the amino group, and H in water. Since the primary amino group generated after the reaction of the NCO group with water can continue to react with the NCO group, it is necessary to have an excess of NCO groups relative to the active hydrogen. For example, the molar ratio of active hydrogen to NCO groups can be any value among 1:1.15, 1:1.17, 1:1.18, 1:1.2, 1:1.22, 1:1.25, etc., or any value in between, without particular limitation. Furthermore, the molar ratio of active hydrogen to NCO groups is 1:1.15-1.20.

[0054] In some embodiments, the weight proportion of the polyether diol in the raw material components of component A is 70-90%, for example, it can be 70%, 75%, 80%, 85%, 90%, etc.;

[0055] The weight proportion of the chain extender in the raw material components of component A is 3-8%, for example, it can be 3%, 4%, 5%, 6%, 7%, 8%, etc.;

[0056] The weight proportion of the crosslinking agent in the raw material components of component A is 0.3-1.5%, for example, it can be 0.3%, 0.5%, 0.7%, 0.8%, 1%, 1.2%, 1.5%, etc.;

[0057] The weight proportion of the surfactant in the raw material components of component A is 0.5-2%, for example, it can be 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.7%, 1.8%, 2%, etc.;

[0058] The weight proportion of the catalyst in the raw material components of component A is 0.5-2.5%, for example, it can be 0.5%, 1%, 1.5%, 2%, 2.5%, etc.;

[0059] The weight proportion of water in the raw material components of component A is 3-5%, for example, it can be 3%, 3.5%, 4%, 4.5%, 5%, etc.

[0060] On the other hand, the present invention also provides an ultra-light and highly elastic insole, which is prepared from the foamed polyurethane material described in any of the above embodiments. The ultra-light and highly elastic insole of the present invention can be formed by the above foamed polyurethane material through a process of infusion and heat curing, and the density of the obtained ultra-light and highly elastic insole can be as low as 0.1-0.12 g / cm 3 , and has good mechanical properties, tensile strength ≥0.8MPa, elongation at break ≥150%, permanent compression deformation ≤15%, and rebound rate ≥25%.

[0061] The technical solution of the present invention is further described and illustrated below based on various embodiments. Unless otherwise specified, the parts in the following embodiments are parts by weight.

[0062] Example 1

[0063] Component A, based on 100% by weight, consists of 5% 1,4-butanediol, 1% diethanolamine, 1% polyether modified silicone oil foaming agent, 1.7% triethylenediamine, 3.5% water and the balance polyether diol;

[0064] The polyether diol is PPG-1000.

[0065] Component B is MDI.

[0066] The molar ratio of active hydrogen in component A to NCO groups in component B is 1:1.18.

[0067] At 25° C., component A and component B were mixed evenly and poured into an insole mold, heated at 60° C. for 3 minutes, and cooled to room temperature to obtain an insole.

[0068] The appearance of the insole obtained in this embodiment is as shown in the attached Figure 1 As shown, the appearance is smooth, indicating good foaming performance.

[0069] Comparative Example 1

[0070] The difference between this comparative example and Example 1 is that in Example 1, diethanolamine is replaced by triethanolamine in an equal weight ratio. The other steps remain unchanged.

[0071] The appearance of the insole obtained in this comparative example is as shown in the attached Figure 2As shown, the appearance is slightly rough, indicating that the foaming performance is not good enough. The possible reason is that some cells shrink after foaming.

[0072] Comparative Example 2

[0073] This comparative example differs from Example 1 in that diethanolamine in Example 1 was replaced with triethylenediamine at an equal weight ratio. The remaining steps remained unchanged. The insole obtained in this comparative example exhibited significant shrinkage, likely due to the excessive use of triethylenediamine as a catalyst, which resulted in an overly rapid catalytic reaction, particularly the reaction between water and NCO groups. This resulted in rapid CO2 production, hindering foaming and causing excessively large pores, which were prone to shrinkage.

[0074] Example 2

[0075] The difference between this embodiment and embodiment 1 is that in embodiment 1, the polyether diol is adjusted to be composed of PPG-1000 and PTMEG-1000 in a weight ratio of 10:1.

[0076] Example 3

[0077] The difference between this embodiment and embodiment 1 is that in embodiment 1, the polyether diol is adjusted to be composed of PPG-1000 and PTMEG-1000 in a weight ratio of 1:1.

[0078] Example 4

[0079] The difference between this embodiment and embodiment 2 is that in embodiment 2, the polyether-modified silicone oil foam leveling agent is adjusted to be composed of the polyether-modified silicone oil foam leveling agent and amino silicone oil in a weight ratio of 5:1.

[0080] The structure of amino silicone oil is shown in the above formula (2), wherein R 3 is methyl, R 4 It is -(CH2)3NH2, a=85.2, b=8.6, c=0.

[0081] Example 5

[0082] The difference between this embodiment and embodiment 2 is that in embodiment 2, the polyether-modified silicone oil foam leveling agent is adjusted to be composed of the polyether-modified silicone oil foam leveling agent and amino silicone oil in a weight ratio of 5:1.

[0083] The structure of amino silicone oil is shown in the above formula (2), wherein R 3 is methyl, R 4 -(CH2)3NH2, R 5 It is -(CH2)3NHCOC2H5, a=70.7, b=6.5, c=4.9.

[0084] Example 6

[0085] The difference between this embodiment and embodiment 5 is that in embodiment 5, the weight ratio of the polyether-modified silicone oil foam leveler to the amino silicone oil is adjusted from 5:1 to 1:1. The remaining steps remain unchanged.

[0086] Example 7

[0087] Component A, based on 100% by weight, consists of 6% 1,4-butanediol, 1.2% dipropanolamine, 1.5% polyether modified silicone oil foaming agent, 2% triethylene diamine, 4% water and the balance polyether diol;

[0088] The polyether diol is a combination of PPG-800 and PTMEG-1200 in a weight ratio of 5:1.

[0089] Component B is MDI.

[0090] The molar ratio of active hydrogen in component A to NCO groups in component B is 1:1.20.

[0091] At 25° C., component A and component B were mixed evenly and poured into an insole mold, heated at 50° C. for 5 minutes, and cooled to room temperature to obtain an insole.

[0092] Example 8

[0093] The difference between this embodiment and embodiment 7 is that the polyether-modified silicone oil foam leveling agent is adjusted to consist of the polyether-modified silicone oil foam leveling agent and amino silicone oil in a weight ratio of 3:1.

[0094] The structure of amino silicone oil is shown in the above formula (2), wherein R 3 is methyl, R 4 -(CH2)3NH2, R 5 It is -(CH2)3NHCOC2H5, a=78.1, b=5.7, c=9.1.

[0095] Performance Testing

[0096] Tensile strength and elongation at break: tested according to the method of GB / T 6344-2008.

[0097] Density: tested according to GB / T 6343-2009.

[0098] Rebound rate: tested according to the method of GB / T 6670-2008.

[0099] Compression set: test temperature 70℃, compression rate 75%, test time 24h.

[0100] Appearance: Visual inspection to see if it is smooth. A smooth appearance indicates good foaming performance.

[0101] The results are shown in Table 1 below.

[0102] Table 1

[0103]

[0104] Therefore, the above results demonstrate that the present invention can produce an ultralight polyurethane foam material. Comparing Example 1 with Comparative Examples 1-2, omitting the crosslinking agent or replacing it with other raw materials results in poor foaming performance, with the cells shrinking after foaming, preventing the achievement of a low foam density, and also impairing resilience. Comparing Example 1 with Examples 4-6, the addition of amino silicone oil further reduces foam density, improves resilience, and reduces compression set. Furthermore, the amide groups in the amino silicone oil further enhance performance.

[0105] As described above, the basic principles, main features, and advantages of the present invention are shown and described. Those skilled in the art should understand that the present invention is not limited to the above-described embodiments. The above-described embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. In other words, equivalent changes and modifications made within the scope of the present invention and the contents of the specification should still fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A foamed polyurethane material, characterized in that: Prepared from component A and component B; The raw material components of the A component include polyether diol, chain extender, cross-linking agent, surfactant, catalyst and water; The chain extender is selected from C2-C8 alkyl glycol; The structure of the cross-linking agent is shown in the following formula (1): HOR 1 National Rural Health Mission 2 OH(1) Among them, R 1 and R 2 independently selected from C1-C6 alkylene; The B component is a polyisocyanate monomer.

2. The foamed polyurethane material according to claim 1, characterized in that The polyether diol is composed of polypropylene glycol and polytetramethylene ether diol in a weight ratio of 1:1-10:1, and the number average molecular weight of the polyether diol is 500-2000.

3. The foamed polyurethane material according to claim 1, characterized in that The surfactant is selected from polyether modified silicone oil and / or amino silicone oil.

4. The foamed polyurethane material according to claim 3, characterized in that The amino silicone oil has an ammonia value of 0.2-2 mmol / g.

5. The foamed polyurethane material according to claim 3, characterized in that: The structure of the amino silicone oil is shown in the following formula (2): R 3 Me2SiO(SiOMe2) a (SioMeR 4 ) b (SioMeR 5 ) c SiMe2R 3 (2) Among them, R 3 is selected from C1-C4 alkyl, R 4 The structure is -(CH2)3(NHCH2CH2) d NH2, R 5 The structure is -(CH2)3(NHCH2CH2) e NHCOR 6 , R 6 Selected from C1-C4 alkyl, Me is methyl, a≥0, b>0, c>0, 0.05≤c / (a+b+c)≤0.3, 10≤a+b+c≤200, d=0-1, e=0-1.

6. The foamed polyurethane material according to claim 1, characterized in that The catalyst is selected from triethylenediamine or a combination of triethylenediamine and bis(2-dimethylaminoethyl)ether.

7. The foamed polyurethane material according to claim 1, characterized in that The polyisocyanate monomer is selected from diisocyanate monomers; Preferably, the isocyanate monomer is selected from MDI.

8. The foamed polyurethane material according to claim 1, characterized in that: The molar ratio of active hydrogen in the A component to NCO groups in the B component is 1:1.15-1.

25.

9. The foamed polyurethane material according to claim 1, characterized in that: The weight proportion of the polyether diol in the raw material components of component A is 70-90%; The weight proportion of the chain extender in the raw material components of component A is 3-8%; The weight proportion of the cross-linking agent in the raw material components of component A is 0.3-1.5%; The surfactant accounts for 0.5-2% by weight of the raw material components of component A; The weight proportion of the catalyst in the raw material components of component A is 0.5-2.5%; The weight proportion of water in the raw material components of component A is 3-5%.

10. An ultra-light and highly elastic insole, characterized in that: The foamed polyurethane material is prepared from the foamed polyurethane material according to any one of claims 1 to 9.

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