Polyurea material and supercritical foaming composite insole

Abstract

The invention provides a polyurea material and a supercritical foaming composite insole, and relates to the technical field of polyurea. The polyurea material is composed of a component A and a component B, the component A at least comprises the following raw material components: first aspartic ester resin and second aspartic ester resin; the first aspartate resin is a Michael addition product of a diamine compound and a first maleate, and the second aspartate resin is a monofunctional aspartate resin and contains an amide group. The polyurea material disclosed by the invention has relatively high mechanical strength and other properties, and the properties of the supercritical foaming material can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of polyurea and relates to a polyurea material and a supercritical foaming composite shoe midsole. Background Art

[0002] Supercritical foaming materials based on polymer materials such as EVA, TPU, and TPEE have been widely used in the fields of footwear, cushioning and shock-resistant materials, and insulation materials due to their low density, good resilience, and low thermal conductivity. Supercritical foaming technology is also being applied to more polymer materials and broadening the application scenarios of polymer materials. However, supercritical foaming materials also have shortcomings such as poor wear resistance and easy dirtiness. For example, supercritical foaming footwear materials are applied to the midsole of shoes. After wearing for a period of time, the supercritical foaming material parts of the midsole of shoes exposed to the outside are prone to wear and dirtiness, which affects the appearance. Chinese patent CN118772600A discloses a highly wear-resistant TPEE supercritical foaming material, which improves the wear resistance of TPEE by adding SEBS-g-MAH and modified calcium sulfate. In addition, with the gradual development of supercritical foaming technology, the performance of the material is getting better and better, but the performance improvement will never stop. It is also a direction to use other materials and form composite materials to improve the performance of supercritical foaming materials. Summary of the invention

[0003] At present, supercritical foaming composite materials are generally prepared by combining two or more polymer materials and forming them into one body and then supercritically foaming them. The applicant has found that the supercritical foaming composite material using a composite layer, that is, adding a thinner polymer layer on the surface of the supercritical foaming material, can also improve the performance of the supercritical foaming composite material by utilizing the excellent properties of the polymer layer.

[0004] Therefore, one object of the present invention is to provide a polyurea material.

[0005] Another object of the present invention is to provide a supercritical foaming composite shoe midsole.

[0006] The technical solution of the present invention is as follows:

[0007] A polyurea material, consisting of component A and component B;

[0008] The raw material components of the A component at least include a first aspartic acid ester resin and a second aspartic acid ester resin;

[0009] The first aspartic acid ester resin is a Michael addition product of a diamine compound and a first maleate;

[0010] The structure of the second aspartic acid ester resin is shown in the following formula (1) or formula (2):

[0011]

[0012] wherein R1 is H or C1-C4 alkyl, R2 is selected from C1-C6 alkylene, R3, R4, R5, R7 and R8 are independently selected from C1-C4 alkyl, and R6 is absent or C1-C6 alkylene;

[0013] The B component is a curing agent.

[0014] Preferably, the structure of the diamine compound is as shown in the following formula (3):

[0015] NH2R9NH2(3)

[0016] Wherein, R9 is selected from C5-C7 cycloalkylene or C6-C20 substituted cycloalkylene.

[0017] Preferably, the weight ratio of the first aspartic acid ester resin to the second aspartic acid ester resin is 100:1-30.

[0018] More preferably, the weight ratio of the first aspartic acid ester resin to the second aspartic acid ester resin is 100:5-20.

[0019] Preferably, the curing agent is an isocyanate curing agent, and the NCO content in the isocyanate curing agent is 10-20wt%.

[0020] More preferably, the isocyanate curing agent contains at least a first adduct obtained by reacting a diamide diol with a first polyisocyanate compound.

[0021] Further preferably, the NCO content of the first adduct is not less than 8 wt %, and the weight proportion of the first adduct in the isocyanate curing agent is not less than 5 wt %.

[0022] More preferably, the structure of the diamide diol is as shown in the following formula (4):

[0023] HOR 10 NHCOR 11 CONHR 10 OH(4)

[0024] Among them, R 10 Selected from C1-10 alkylene, R 11 is absent or is a C1-C8 alkylene group, a C5-C7 cycloalkylene group, a C6-C10 substituted cycloalkylene group or a C6-C12 arylene group.

[0025] Preferably, the isocyanate curing agent further contains a second adduct obtained by reacting a polyether polyol or a polyester polyol with a second polyisocyanate compound.

[0026] A supercritical foamed composite shoe midsole comprises a supercritical foamed shoe material and a polyurea layer, wherein the polyurea layer is coated on the surface of the supercritical foamed shoe material, and the polyurea layer is obtained from the polyurea material described in any one of the above embodiments.

[0027] The beneficial effects of the present invention are:

[0028] (1) The present invention adds a second aspartic acid ester resin having an amide structure and monofunctionality to the existing aspartic acid ester resin. The amide structure is easy to form hydrogen bonds and can also form hydrogen bonds with other polar groups containing O, N, etc., further increasing the number and density of hydrogen bonds inside the polyurea material, so that the polyurea material has higher mechanical strength, wear resistance and other properties. The low viscosity of the second aspartic acid ester resin can also reduce the viscosity of component A, so that the polyurea material can be sprayed and other processes, and the solid content of the polyurea material is very high (more than 95%), and the environmental protection is good. The introduction of the amide structure into the isocyanate curing agent can also further improve the mechanical strength, wear resistance and other properties of the polyurea material.

[0029] (2) A polyurea layer formed by the polyurea material of the present invention is coated on the surface of the supercritical foaming material to form a supercritical foaming material composite material, which has higher properties such as resilience and tensile strength than a single supercritical foaming material. DETAILED DESCRIPTION

[0030] The technical solution of the present invention is further illustrated and described below through specific implementation methods.

[0031] In order to improve the performance of polyurea materials, especially the mechanical strength and wear resistance, the present invention provides a polyurea material, which is composed of component A and component B;

[0032] The raw material components of component A at least include a first aspartic acid ester resin and a second aspartic acid ester resin;

[0033] The first aspartic acid ester resin is a Michael addition product of a diamine compound and a first maleate;

[0034] The structure of the second aspartic acid ester resin is shown in the following formula (1) or formula (2):

[0035]

[0036] wherein R1 is H or C1-C4 alkyl, R2 is selected from C1-C6 alkylene, R3, R4, R5, R7 and R8 are independently selected from C1-C4 alkyl, and R6 is absent or C1-C6 alkylene;

[0037] Component B is a curing agent.

[0038] In the present invention, the first aspartic acid ester resin is a difunctional aspartic acid ester resin, and contains 2 secondary amine groups in the resin structure, as the main film-forming raw material component of the A component and cross-linked and cured film-forming with a curing agent. The second aspartic acid ester resin is a monofunctional aspartic acid ester resin, and the molecule is relatively small, and the viscosity is relatively low, and the viscosity of the A component can be reduced, and it is more suitable to adopt a spraying process, and contains an amide group in the molecular structure, and more hydrogen bonds can be formed between the amide groups and between the amide groups and the ester groups, and the number of hydrogen bonds in the A component is more, and the density is higher, and the mechanical strength, wear resistance, impact resistance and other properties of the polyurea material are improved. If a plurality of amide groups are contained in the second aspartic acid ester resin, due to too many and too strong internal hydrogen bonding, the viscosity of the second aspartic acid ester resin will be larger, and the state at room temperature will be semi-solid or solid, which will cause the viscosity of the A component and the polyurea material to be too large, which is unfavorable for construction or is unfavorable for the permeability of the polyurea material to the substrate surface, and may affect the bonding force of the polyurea material and the substrate. The second aspartic acid ester resin of the present invention contains only one amide group in its structure, which can provide the hydrogen bonding effect of the amide group and prevent the viscosity of the second aspartic acid ester resin from being too high.

[0039] In the present invention, the second aspartic acid ester resin represented by the above formula (1) or formula (2) can be obtained by Michael addition reaction of a monoamino compound represented by the following formula (5) or (6) with a second maleate (or fumarate),

[0040]

[0041] Wherein, R1, R2, R5 and R6 have the same meanings as described above. For example, the monoamino compound shown in formula (5) can be 2-amino-N-cyclohexylacetamide, 2-amino-N-(4-methylcyclohexyl)acetamide, 2-amino-N-(3-methylcyclohexyl)acetamide, etc., and the monoamino compound shown in formula (6) can be N-(3-aminocyclohexyl)acetamide, N-(4-aminocyclohexyl)acetamide, N-(4-aminocyclohexyl)propionamide, etc.

[0042] In the present invention, the first maleate and the second maleate can be dimethyl maleate, diethyl maleate, diisobutyl maleate, etc., respectively. From the perspective of practical industrial application, the first maleate and the second maleate can be diethyl maleate, respectively.

[0043] In some embodiments, the structure of the diamine compound is shown in the following formula (3):

[0044] NH2R9NH2(3)

[0045] Wherein, R9 is selected from C5-C7 cycloalkylene or C6-C20 substituted cycloalkylene. For example, the diamine compound can be 4,4'-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 1,2-diaminocyclohexane, 1,4-diaminocyclohexane, 1,3-diaminocyclopentane, etc. The first aspartic acid ester resin can be a commercially available aspartic acid ester resin, such as F420 and F520 of Feiyang Junyan Company, NH1420 and NH1520 of Bayer Company, etc.

[0046] In some embodiments, the weight ratio of the first aspartic acid ester resin to the second aspartic acid ester resin is 100:1-30. For example, the weight ratio of the first aspartic acid ester resin to the second aspartic acid ester resin can be any value in 100:1, 100:3, 100:5, 100:8, 100:10, 100:12, 100:15, 100:17, 100:20, 100:22, 100:25, 100:27, 100:28, 100:30, etc., without special restrictions. The second aspartic acid ester resin is monofunctional. If the content of the second aspartic acid ester resin is too high, the crosslinking density of the polyurea material may be insufficient after curing, thereby affecting the curing of component A or failing to cure normally.

[0047] More preferably, the weight ratio of the first aspartic acid ester resin to the second aspartic acid ester resin is 100:5-20.

[0048] Pigments, fillers, defoamers, wetting agents, etc. may also be added to the above-mentioned component A, which is well known to those skilled in the art.

[0049] In certain embodiments, the curing agent is an isocyanate curing agent, and the content of NCO in the isocyanate curing agent is 10-20wt%. The isocyanate curing agent can react quickly with the first aspartic acid ester resin and the second aspartic acid ester resin in component A, and the reaction is relatively sufficient. In the present invention, the content of NCO in the isocyanate curing agent can be any value of 10wt%, 10.5wt%, 11wt%, 11.5wt%, 12wt%, 12.5wt%, 13wt%, 13.5wt%, 14wt%, 14.5wt%, 15wt%, 15.5wt%, 16wt%, 16.5wt%, 17wt%, 17.5wt%, 18wt%, 18.5wt%, 19wt%, 19.5wt%, 20wt%, etc., without special restrictions. In the present invention, the weight ratio of component A to component B can be converted according to the molar ratio of -NH- groups in component A to NCO groups in component B of 1:1-1.1.

[0050] More preferably, the isocyanate curing agent contains at least a first adduct obtained by reacting a diamide diol with a first polyisocyanate compound. The first adduct contains an amide group, which has the same function as the amide group in the second aspartic acid ester resin, and can enhance the hydrogen bonding effect in the polyurea material, thereby improving the mechanical strength, impact resistance, wear resistance, etc. of the polyurea material.

[0051] Further preferably, the NCO content of the first adduct is not less than 8wt%, and the weight proportion of the first adduct in the isocyanate curing agent is not less than 5wt%. For example, the NCO content of the first adduct can be any value of 8wt%, 8.5wt%, 9wt%, 9.5wt%, 10wt%, 10.5wt%, 11wt%, 11.5wt%, 12wt%, 12.5wt%, 13wt%, 13.5wt%, 14wt%, 14.5wt%, 15wt%, 15.5wt%, 16wt%, 16.5wt%, 17wt%, 17.5wt%, etc., without special restrictions. The NCO group content in the first adduct can be adjusted and determined according to the molar ratio of the diamide diol to the first polyisocyanate compound, etc. If the weight proportion of the first adduct in the isocyanate curing agent is too small, the effect of the amide group is not obvious. For example, the weight proportion of the first adduct in the isocyanate curing agent can be any value of 5wt%, 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, 60wt%, 65wt%, 70wt%, etc., without special restrictions. More preferably, the weight proportion of the first adduct in the isocyanate curing agent is not less than 15wt%.

[0052] More preferably, the structure of the diamide diol is as shown in the following formula (4):

[0053] HOR 10 NHCOR 11 CONHR 10 OH(4)

[0054] Among them, R 10 Selected from C1-10 alkylene, R 11 is absent or C1-C8 alkylene, C5-C7 cycloalkylene, C6-C10 substituted cycloalkylene or C6-C12 aromatic group. For example, the diamide diol can be N,N'-bis(2-hydroxyethyl)oxalamide, N,N'-bis(2-hydroxyethyl)adipamide, N,N'-bis(2-hydroxyethyl)succinamide, N,N'-bis(2-hydroxypropyl)oxalamide, N,N'-bis(2-hydroxypropyl)adipamide, etc.

[0055] In some embodiments, the isocyanate curing agent further contains a second adduct obtained by reacting a polyether polyol or a polyester polyol with a second polyisocyanate compound. The polyether polyol may be a polyether diol, a polyether triol, etc., and the polyester polyol may be a polyester diol, a polyester triol, etc. The number average molecular weight of the polyether polyol or the polyester polyol may be 400-3000, or further, 500-2000. The NCO group content of the second adduct may be not less than 5wt%. The preparation method of the second adduct is not particularly limited, for example, it can be prepared according to the method of Example 6, Example 7 or Example 8 in Chinese Patent CN116505066A.

[0056] In the present invention, the first polyisocyanate compound and the second polyisocyanate compound are not particularly limited, and for example, they may be diisocyanate compounds, such as IPDI, HMDI, HDI, TDI, etc., or triisocyanate compounds, such as HDI trimer.

[0057] In the present invention, when the functionality of the second adduct is greater than 2, the isocyanate curing agent can be a combination of the first adduct and the second adduct, or a combination of the first adduct, the second adduct and the HDI trimer; when the functionality of the second adduct is 2, the isocyanate curing agent can be a combination of the first adduct, the second adduct and the HDI trimer.

[0058] On the other hand, the present invention provides a supercritical foaming composite shoe midsole, comprising a supercritical foaming shoe material and a polyurea layer, wherein the polyurea layer is coated on the surface of the supercritical foaming shoe material, and the polyurea layer is obtained from the polyurea material described in any one of the above embodiments. Even if the thickness of the polyurea layer of the supercritical foaming composite shoe midsole is relatively thin (e.g., 50-500 μm), the supercritical foaming composite shoe midsole has higher resilience, mechanical strength, wear resistance, etc. than a single supercritical foaming shoe material.

[0059] The technical solution of the present invention is further described and illustrated according to various embodiments below. Unless otherwise specified, the parts described in the following embodiments are parts by weight.

[0060] Preparation Example 1-3 Preparation of Second Aspartic Acid Ester Resin

[0061] Preparation Example 1

[0062] N-(3-aminocyclohexyl)acetamide and diethyl maleate were added to a reaction vessel in a molar ratio of 1:1.2, the temperature was raised to 90°C, the reaction was continued for 72 hours, the pressure was reduced to below -0.099 MPa, the temperature was raised to 160°C to remove low boiling points, the temperature was lowered to obtain the second day aspartic acid ester resin, recorded as resin P1, and the viscosity at 25°C was measured by a rotational viscometer NDJ-5S to be 41 mPa.s.

[0063] Preparation Example 2

[0064] N-(4-aminocyclohexyl)acetamide and diethyl maleate were added to a reaction vessel in a molar ratio of 1:1.2, the temperature was raised to 90°C for reaction for 72 hours, the pressure was reduced to below -0.099 MPa, the temperature was raised to 160°C to remove low boiling points, the temperature was lowered to obtain the second day aspartic acid ester resin, recorded as resin P2, and the viscosity at 25°C was measured by a rotational viscometer NDJ-5S to be 40 mPa.s.

[0065] Preparation Example 3

[0066] 2-Amino-N-cyclohexylacetamide and diethyl maleate were added to a reaction vessel in a molar ratio of 1:1.2, the temperature was raised to 90°C for reaction for 48 hours, the pressure was reduced to below -0.099 MPa, the temperature was raised to 160°C to remove low boiling points, the temperature was lowered to obtain the second aspartic acid ester resin, recorded as resin P1, and the viscosity at 25°C was measured by a rotational viscometer NDJ-5S to be 47 mPa.s.

[0067] Example 1

[0068] The polyurea material consists of component A and component B, and the molar ratio of the NH group in component A to the NCO group in component B is 1:1.05.

[0069] The A component consists of 100 parts of F420 resin and 1 part of resin P1 obtained in Preparation Example 1.

[0070] Component B is a combination of the second adduct and HDI trimer, and the NCO content in component B is 17.5 wt%.

[0071] The second adduct was prepared according to the method of Example 7 in Chinese Patent CN116505066A.

[0072] Example 2

[0073] The difference between this embodiment and embodiment 1 is that in embodiment 1, the resin P1 is adjusted from 1 part to 5 parts. The other steps remain unchanged.

[0074] Example 3

[0075] The difference between this embodiment and embodiment 1 is that in embodiment 1, the resin P1 is adjusted from 1 part to 20 parts. The other steps remain unchanged.

[0076] Example 4

[0077] The difference between this embodiment and embodiment 1 is that in embodiment 1, the resin P1 is adjusted from 1 part to 30 parts. The other steps remain unchanged.

[0078] Comparative Example 1

[0079] The difference between this comparative example and Example 1 is that in Example 1, the resin P1 is replaced by F420 resin, and the other steps remain unchanged.

[0080] Comparative Example 2

[0081] The difference between this comparative example and Example 1 is that in Example 1, the resin P1 is adjusted from 1 part to 35 parts. The other steps remain unchanged.

[0082] Example 5

[0083] The polyurea material consists of component A and component B, and the molar ratio of the NH group in component A to the NCO group in component B is 1:1.04.

[0084] Component A is composed of 100 parts of F520 resin, 15 parts of resin P2 obtained in Preparation Example 2, 0.6 parts of polyether modified silicone oil wetting agent and 0.5 parts of dimethyl silicone oil defoaming agent.

[0085] The B component is a combination of the first adduct, the second adduct and the HDI trimer. The NCO content in the B component is 16.3 wt %, and the weight proportion of the first adduct in the B component is 6%.

[0086] The preparation method of the first adduct is as follows: 10 parts of N, N'-bis (2-hydroxyethyl) adipamide and 40 parts of tetrahydrofuran are added to a reaction container, and after stirring and dissolving, 1.6 times the molar number of N, N'-bis (2-hydroxyethyl) adipamide IPDI is added, stirred at room temperature for 2 hours, heated to a micro-reflux of the reaction system, and continued to react for 2 hours, and tetrahydrofuran is removed to obtain the first adduct. The NCO content of the first adduct is measured to be 8.3wt%.

[0087] The second adduct is the second adduct in Example 1.

[0088] Example 6

[0089] The difference between this embodiment and embodiment 5 is that in embodiment 5, the weight proportion of the first adduct in component B is adjusted from 6% to 15%. The other steps remain unchanged.

[0090] Example 7

[0091] The difference between this embodiment and embodiment 5 is that in embodiment 5, the weight proportion of the first adduct in component B is adjusted from 6% to 40%. The other steps remain unchanged.

[0092] Example 8

[0093] The difference between this embodiment and embodiment 5 is that in embodiment 5, the first adduct is replaced by the second adduct of equal weight, and the other steps remain unchanged.

[0094] Example 9

[0095] The difference between this example and Example 5 is that in Example 5, the resin P2 is replaced by an equal weight of the resin P3 obtained in Preparation Example 3. The remaining steps remain unchanged.

[0096] Performance Testing

[0097] The tensile strength was tested according to the method of GB / T 528-2009; the tear strength was tested according to the method of GB / T529-2008; and the abrasion resistance (750g / 1000r) was tested according to the method of GB / T 1768-2996. The results are shown in Table 1 below.

[0098] Table 1

[0099] Tensile strength / MPa Tear strength / KN / m Wear resistance / mg Example 1 13.3 89 9.5 Example 2 17.0 102 8.1 Example 3 19.1 109 7.3 Example 4 15.6 97 8.4 Comparative Example 1 12.5 83 10.1 Comparative Example 2 10.2 51 14.7 Example 5 18.5 112 7.0 Example 6 19.0 115 6.6 Example 7 21.4 122 5.8 Example 8 17.8 106 7.4 Example 9 18.1 108 7.2

[0100] It can be seen from the data results in Table 1 that the polyurea material of the present invention has higher tensile strength, tear strength and wear resistance.

[0101] The polyurea materials of Examples 2, 5 and 7 were sprayed onto the surface of a supercritical foamed TPU with a thickness of 1 cm, with film thicknesses of 20 μm and 100 μm, respectively, and left at room temperature for 24 hours.

[0102] The tensile strength was tested according to ISO 1798:2008, and the ball rebound was tested according to ASTM D3574. The results are shown in Table 2 below.

[0103] Table 2

[0104]

[0105] Therefore, the above Table 2 shows that the composite layer supercritical foam material formed by covering the surface of the supercritical foam material with a layer of the polyurea material of the present invention has better tensile strength and ball rebound resilience. When the composite layer supercritical foam material is used as a shoe midsole material, the performance of the shoe can be improved.

[0106] 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 by the above embodiments, which are only preferred embodiments of the present invention and cannot be used to limit the scope of the present invention. That is, equivalent changes and modifications made according to the scope of the present invention and the contents of the specification should still be within the scope of the present invention. The scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims

1. A polyurea material, characterized in that: It is composed of component A and component B; The raw material components of the A component at least include a first aspartic acid ester resin and a second aspartic acid ester resin; The first aspartic acid ester resin is a Michael addition product of a diamine compound and a first maleate; The structure of the second aspartic acid ester resin is shown in the following formula (1) or formula (2): wherein R1 is H or C1-C4 alkyl, R2 is selected from C1-C6 alkylene, R3, R4, R5, R7 and R8 are independently selected from C1-C4 alkyl, and R6 is absent or C1-C6 alkylene; The B component is a curing agent.

2. The polyurea material according to claim 1, characterized in that: The structure of the diamine compound is shown in the following formula (3): NH2R9NH2(3) Wherein, R9 is selected from C5-C7 cycloalkylene or C6-C20 substituted cycloalkylene.

3. The polyurea material according to claim 1, characterized in that: The weight ratio of the first aspartic acid ester resin to the second aspartic acid ester resin is 100:1-30.

4. The polyurea material according to claim 3, characterized in that: The weight ratio of the first aspartic acid ester resin to the second aspartic acid ester resin is 100:5-20.

5. The polyurea material according to claim 1, characterized in that: The curing agent is an isocyanate curing agent, and the content of NCO in the isocyanate curing agent is 10-20wt%.

6. The polyurea material according to claim 5, characterized in that: The isocyanate curing agent contains at least a first adduct obtained by reacting a diamide diol with a first polyisocyanate compound.

7. The polyurea material according to claim 6, characterized in that: The NCO content of the first adduct is not less than 8wt%, and the weight proportion of the first adduct in the isocyanate curing agent is not less than 5wt%.

8. The polyurea material according to claim 6, characterized in that: The structure of the diamide diol is shown in the following formula (4): HOR 10 NHCOR 11 CONHR 10 OH(4) Among them, R 10 Selected from C1-10 alkylene, R 11 is absent or is a C1-C8 alkylene group, a C5-C7 cycloalkylene group, a C6-C10 substituted cycloalkylene group or a C6-C12 arylene group.

9. The polyurea material according to claim 5, characterized in that: The isocyanate curing agent further contains a second adduct obtained by reacting a polyether polyol or a polyester polyol with a second polyisocyanate compound.

10. A supercritical foaming composite shoe midsole, characterized in that: The invention comprises a supercritical foaming shoe material and a polyurea layer, wherein the polyurea layer is coated on the surface of the supercritical foaming shoe material, and the polyurea layer is obtained from the polyurea material according to any one of claims 1 to 9.

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