CN116178781A - Polyurethane composite material for multipurpose comfortable shoe material and preparation method thereof - Google Patents

Abstract

The invention is disclosed inA polyurethane composite material for a multi-path comfortable shoe material and a preparation method thereof are provided, belonging to the technical field of polyurethane composite materials. The invention adopts solid sphere shear thickening fluid capsules and hollow sphere expandable beads to carry out virtual-real two-phase reinforcement on polyurethane foam, not only can improve the mechanical property of the foam composite material, but also can enhance the energy absorption efficiency of the foam composite material on the premise of ensuring that the density of the foam material is basically unchanged, and has a certain damping effect on external loading load for improving the stress sensitivity, and simultaneously, the reaction is carried out at room temperature, the room temperature is solidified, the energy consumption is reduced, and the large-area application is facilitated. The two-phase reinforced polyurethane foam composite material has energy absorption efficiency which is several times higher than that of the conventional polyurethane foam, and the energy absorption can reach 57.2162KJ/m ³ The compression strength reaches 3.0888MPa, and the apparent density is kept to be 0.311g/cm ³ ‑0.351g/cm ³ 。

Description

Polyurethane composite material for multipurpose comfortable shoe material and preparation method thereof

technical field

The invention relates to a polyurethane composite material for multi-purpose comfortable shoe materials and a preparation method thereof, belonging to the technical field of polyurethane composite materials.

Background technique

Polyurethane foam is a block copolymer elastomer composed of urethane bonds (—NHCOO—) connecting soft and hard segments. It is a polymer material with light weight, cushioning, and heat preservation properties. It is made of polyurethane foam. Shoe materials have good properties, such as light weight, impact resistance, chemical resistance, abrasion resistance and bending resistance. In order to pursue a light weight effect, one of the conventional methods to reduce the density of polyurethane foam is to use water as a blowing agent, but the introduction of water will lead to the increase of urea bonding and destroy the mechanical properties of the substrate. Stress softening will occur, shortening the service life of the shoe material. Therefore, mechanical properties are also the focus of polyurethane composite materials for shoe materials.

With the rapid economic development and the accelerated pace of life, people's requirements for shoes are not only comfortable, but also require long service life and multi-functionality, that is, to meet the needs of different usage scenarios and different users for shoe materials. The resilience of polyurethane shoe materials comes from the compression and release of its cell structure. Generally, flexible polyurethane foam materials are mostly homogeneous and open-cell structures. When slightly compressed, they can rely on their material strength to achieve dimensional recovery. When the cell structure is broken, the dimensional stability, recovery ability and energy absorption efficiency of the material are reduced. Therefore, energy absorption efficiency is also one of the important concerns of polyurethane composite materials for shoe materials.

Under the condition of maintaining low density, strengthening polyurethane foam can increase the application range of polyurethane foam for shoe materials. The main methods are: adding thermal foaming microspheres, adjusting the proportion and functionality of polyols, and optimizing the configuration of crosslinking agents , in addition to adding shear thickening materials and other methods. Among them, adding heat-expandable microspheres is the most convenient, low-cost, and does not increase or decrease the density.

Hollow spherical expandable beads are heat-expandable microspheres, and the outer layer is a thermoplastic resin with good gas barrier properties, which is generally formed by homopolymerization or copolymerization of monomers such as vinylidene chloride, acrylonitrile, and methacrylonitrile When the core-shell material is raised to a certain temperature, the polymer layer will soften; while the internal boiling point is lower than that of the shell hydrocarbons, which will decompose and volatilize before the polymer softens, which will cause the microspheres to expand. Foam matrix for enhanced support. The existing foaming system controls the cell size mainly by changing the number of hydroxyl groups in the polyether polyol, the types of foam stabilizers, catalysts, foaming agents and filling materials. Among them, the method of changing the filler is the most convenient and stable. For example, at present, Liu Xu of Zhejiang Huafeng New Material Co., Ltd. uses thermal foaming microspheres to strengthen the polyurethane foam matrix (CN101486801B). ³ , the available polyurethane elastomer shoe sole material has an apparent density of 0.28g/cm ³ , a tensile strength of 4.3MPa, and a hardness of ShoreC of 72; however, this invention simply adds expandable beads, What brings more to the system is the closed-cell structure, which lacks some exhaust and ventilation processes. The foam produced by this process is relatively hard, that is, the soles are stiff and rebound in leisure environments such as slow walking. If the feeling is weak, the corresponding energy absorption efficiency will be greatly reduced, and the comfort level will be poor.

Shear thickening fluid (Shear Thickening Fluid, STF) is a stress-sensitive material, which uses colloidal particles to disperse to form a suspension. At high shear rates, the particles of the suspension are coupled to each other into a closed trajectory to form particle clusters. At this time, the particles The particle concentration of the cluster is relatively large. When the system is sheared, the energy consumed increases, resulting in an increase in viscosity. The change in viscosity is used to achieve a highly nonlinear change in mechanical properties. Adding shear thickening materials to polyurethane foam can make the viscosity of the system variable and dissipate the energy of the applied stress, so as to achieve reinforcement. For example, Liu Xiaoke of Jiangnan University used shear thickening materials to enhance and modify polyurethane foam, and introduced the stress response characteristics of shear thickening materials into the composite material system to achieve an 80-90% increase in specific strength and specific energy absorption. However, in this report, the shear thickening material is directly in contact with the polyurethane foam, and the alcohol group in it will destroy the molding of the polyurethane foam to a certain extent, increasing the number of open cells and increasing the pore size, and the foam is prone to rupture and failure. For the shear thickening liquid, it is also reported that Liu Xing of Tianjin University of Technology prepared a series of STF capsule/polyurethane foam composite materials by using self-made shear thickening liquid. His research shows that adding an appropriate amount of STF capsule can improve the comprehensive mechanical properties of the composite material. The increase is more than 1 times; the purpose of using shear thickening liquid capsules in this report is to apply shear thickening liquid more conveniently. The content of STF capsules reaches 30%, and the corresponding foam density increases significantly. The material is harder, which is not conducive to shoe material application.

In summary, it is necessary to prepare polyurethane composite materials for shoe materials with moderate mechanical properties and good energy absorption efficiency while maintaining a low density.

Contents of the invention

Aiming at the above-mentioned problems in the prior art, the present invention provides a method for preparing a polyurethane composite material for multipurpose comfortable shoe materials. The invention adopts solid sphere shearing thickening liquid capsules and hollow sphere expandable beads to strengthen polyurethane foam in both virtual and solid phases, and the reaction can be carried out at room temperature, which is beneficial to large-area preparation and has cheap and easy-to-obtain raw materials. This method uses expandable beads as hollow balls, which are hollow inside. After thermal expansion in the foaming stage, an expanded ball with a stable size can be formed, which can exist in the foam system as closed cells, and the ratio of open and closed cells is regulated, which is beneficial to bear the load. .

In the preparation method of the present invention, by effectively controlling the ratio of the amount of substances used, under the premise of ensuring that the density of the foam material is basically unchanged, two-phase reinforcement of solid spheres and hollow spheres is carried out, which can not only improve the mechanical properties of the foam composite material but also enhance its Energy absorption efficiency, and the improvement of stress sensitivity has a certain damping effect on external loads. At the same time, the reaction occurs at room temperature and can be cured at room temperature, which reduces energy consumption and is conducive to large-area applications.

The invention provides a method for preparing a polyurethane composite material for multipurpose comfortable shoe materials, comprising:

(1) Mix material A (polyether polyol), foaming catalyst, deionized water, anti-yellowing agent, gel catalyst, hollow ball expandable beads and solid ball shear thickening liquid capsule in a predetermined ratio , to obtain the matrix preform.

(2) Mix the matrix prefabricated material and material B (isocyanate) evenly according to a predetermined ratio, and stir it mechanically for 6-10 seconds, pour it into the mold quickly and flow evenly, and carry out compression molding. After 2-5 minutes after the foaming is completed, open the mold and take out the material , aging at 20-28 degrees Celsius for 20 minutes to obtain a polyurethane composite material for shoe materials.

In one embodiment, the shear thickening liquid is firstly prepared into solid spherical shear thickening liquid capsules, which are dried at room temperature for later use.

In one embodiment, the preparation method of the shear thickening liquid capsule is to use a surfactant, sodium alginate solution, and calcium chloride solution to prepare the shear thickening liquid capsule.

In one embodiment, the preparation method of self-made shear thickening liquid is to mix ethylene glycol (PEG) with a mass ratio of 3:1 and silicon dioxide (SiO ₂ ) powder, and place it in a refrigerator at 25°C after fully stirring. Vacuum drying chamber for 24 hours to remove air bubbles and obtain a shear thickened liquid.

In one embodiment, the surfactant used in the preparation of the shear thickening liquid capsule is Span series, the addition amount is 10-30%, the concentration of sodium alginate solution is 5-10 mg/mL, and the concentration of calcium chloride solution is 10～20mg/mL.

In one embodiment, the preparation method of the shear thickening liquid capsule adopts the method of Xing Liu of Tianjin University of Technology to prepare the shear thickening liquid capsule. The specific steps are: drop the prepared shear thickening fluid (Shear Thickening Fluid, STF) into liquid paraffin to form a water-in-oil emulsifier, stir at 25°C for 30 minutes; add the hydrophilic surfactant to the sodium alginate solution Mix well, then slowly add water-in-oil emulsifier; mix for 20 minutes at 25°C to form a water-in-oil-in-water multiple emulsion. Draw the water-in-oil-in-water multiple emulsion into a small diameter syringe. The syringe is set as a micro-syringe pump with a driving speed of 8-13 μL/min, pushing it into the prepared calcium chloride solution to form spherical droplets. Rinse with deionized water and dry at room temperature.

In one embodiment, the mass parts of each component in step (1) is 100 parts of material A, 2 to 4 parts of foaming catalyst, 0.3 to 0.4 parts of deionized water, 3 to 5 parts of anti-yellowing agent, The gel catalyst is 0.15-0.2 parts, the hollow ball expandable beads is 1-5 parts, and the solid ball shear thickening liquid capsule is 1-5 parts.

In one embodiment, in step (1), 1-3 parts of hollow sphere expandable beads and 1-3 parts of solid sphere shear thickening liquid capsule.

In one embodiment, in step (1), there are 3 parts of hollow sphere expandable beads and 3 parts of solid sphere shear thickening liquid capsule.

In one embodiment, the hollow spherical expandable beads (or heat-expandable microspheres, expandable foaming microspheres, etc.) used in step (1) are EXPANCEL series, DE series, UM115 series, UM116 series One or more of them, the primary particle size is 6-10 μm, and the minimum foaming temperature is 80-85°C.

In one embodiment, the mass fraction of material B in step (2) is 60-75 parts.

In one embodiment, the mass fraction of material B in step (2) is 70 parts.

In the present invention, material A and material B can be the AB material of the existing polyurethane soft foam; such as the polyether polyol mentioned in "Polyurethane Foam Handbook"-conventional proportioning-polyether polyol for insoles.

In one embodiment, material A is one or more of polyether diols or polyether triols.

In one embodiment, material B is one or more of isocyanate or liquefied diphenylmethane diisocyanate.

In the present invention, the AB material, foaming catalyst, anti-yellowing agent, gel catalyst, etc. used in the polyurethane foam preparation process are all conventional polyurethane foam preparation raw materials and can be purchased commercially. For example, foam catalysts, gel catalysts, can be purchased under the brands of Huafon, Huntsman, Momentive, Gas and Chen.

In one embodiment, the foaming catalyst, anti-yellowing agent and gel catalyst are purchased from China Huafeng Group.

In one embodiment, the anti-yellowing agent used is one or more of HN130, HN150, and C-21.

In the present invention, the mass fraction of material B needs to be strictly controlled, otherwise the foaming reaction will not be complete and the curing effect will be poor. The foaming time is also a key point. If the mixing time is insufficient, it may be sent to the pressure mold for foaming before sufficient contact may result in incomplete foaming or no foaming at all; if the mixing time is too long, it will start before being transferred to the mold If it is foamed, the obtained product will have too large pores and the output will decrease. The foaming temperature also has a significant effect on the cells. The mixed reaction of material A and material B will release heat equivalent to the degree of reaction. The ratio directly affects the expansion rate of the expandable beads.

In the present invention, when the AB material reacts, the ambient temperature affects both reaction efficiency and speed. When the temperature is lower than 15°C, the reaction efficiency and speed of the two are greatly affected. Preferably, the working environment is kept at around 25°C.

The second object of the present invention is to provide a polyurethane composite material for multipurpose comfortable shoe materials prepared according to the above method.

In the present invention, the shear thickening liquid is made into capsules and mixed into the system in the form of solid spheres, which improves the problem of interfacial compatibility and avoids the direct contact between too many alcohols and isocyanate to damage the foaming effect; and Liu Xing from Tianjin University of Technology is different. The purpose of using shear thickening liquid capsules in the present invention is to better retain the characteristics of shear thickening. At the same time, it is dispersed in the foam elastomer in the form of solid balls, and the local stress-strain sensitivity is enhanced, and it provides stronger rebound and support effects macroscopically during high-speed ballasting. The shear thickening properties of STF capsules and the excellent cushioning properties of polyurethane foam are the reasons for the improved mechanical properties of the composites. In addition, the present invention synergizes the capsules of the shear thickening solution and the expandable beads in the polyurethane foam, and the density of the expandable beads can partially offset the adverse effects of the capsules of the shear thickening solution.

In the present invention, by adding hollow spherical expandable beads and solid spherical shear thickening liquid capsules, the closed cell ratio in the cell structure is increased, and the energy absorption effect of the composite material is improved. Although the solid sphere shear thickening liquid capsule increases the density of the composite material to a certain extent, adding an appropriate amount can not only improve the effect of energy absorption and resistance reduction, but also enrich the bubbles and form cell clusters. The hollow sphere expandable beads are distributed on the cell wall of the polyurethane foam to form micropores, which indirectly reduces the cell size formed by foaming, and the finer foam is conducive to the improvement of mechanical properties. In addition, the introduction of hollow spheres also reduces the density of the composite.

The polyurethane foam of the invention can be applied to the field of energy-absorbing shoe materials.

The present invention also provides the application of the polyurethane composite material for multi-purpose comfortable shoe materials, specifically for making multi-purpose comfortable shoe materials to provide matching support strength and Shock absorbing effect. At the same time, the universality of age and body shape is improved. When the elderly use this shoe material, the existence of the hollow ball reduces the density of the composite material. Ball-shear thickener capsules respond to low-velocity loads with less change in viscosity and less irritation on the ball of the foot. When heavy people use this shoe material, the solid ball shear thickening liquid capsule can provide better support for the composite material system, avoid stress collapse, and prolong the service life.

Advantages and effects of the present invention:

1. The present invention uses a solid sphere shear thickening liquid capsule, and the shear thickening liquid has a damping effect under stress conditions, which can change the viscosity of the system to achieve energy absorption and dissipation. In addition, the outer calcium alginate shell also absorbs impact energy, thereby enhancing the strength of the STF capsule. Thus, the overall composite can be stress-sensitive due to the damping properties of the STF capsules in terms of mechanical forces. In the present invention, the introduction of the shear thickening liquid capsule can adjust the strain rate effect and change the cell structure (there are small cells on the cell); through STF capsule-solid sphere, expandable bead microsphere-hollow sphere, Give full play to the role of the real matrix and cell structure to realize the super comfort of casual shoes, suitable for all kinds of fast walking shoes and slow walking shoes.

2. The present invention enhances the elasticity and mechanical strength of the matrix through hollow spherical expandable beads, which can partially replace water as a foaming agent, thereby eliminating foam collapse to a certain extent. When the expandable beads are heated and expanded, the particle size can reach 10-20 μm, which can achieve a stable cell size. At the same time, due to its closed form, the open and closed porosity of the foam system can be adjusted, thereby improving the energy absorption efficiency of the overall composite material. compressive strength.

3. The two-phase reinforced polyurethane foam composite material of the present invention has energy absorption efficiency several times higher than that of conventional polyurethane foam, and the energy absorption can reach 52.4489KJ/m ³ -57.2162KJ/m ³ ; meanwhile, the compressive strength can reach 3.0888MPa-3.7076MPa , but also maintain an apparent density of 0.311g/cm ³ -0.351g/cm ³ . The apparent density of polyurethane used for shoe materials is usually 0.2-0.4g/cm ³ , and the apparent density of this patent is kept in the range of 0.3-0.35g/cm ³ , which can provide a comfortable foot feeling, neither light nor heavy, It has a shoe feel but is not cumbersome. It can provide foot support and cushioning performance in daily leisure and competitive sports scenes, protect the knees, and magnify the benefits of sports.

Description of drawings

Figure 1 is a schematic cross-sectional view of the composite material, in which 1-1 is a solid sphere shear thickening liquid capsule, and 1-2 is a hollow sphere expandable bead.

Figure 2 is the SEM scanning image of the composite material.

specific implementation plan

test methods:

1. Determination method of apparent density: according to GB/T6343-1995 Determination of apparent (volume) density of foamed plastics and rubber, cut into a sample with a size of 20×20×10mm, accurately measure the length, width and height of the sample, Accurate to 0.02mm. Then use an electronic balance to accurately weigh the sample mass, requiring an accuracy of 0.0001g, and then calculate the apparent density.

2. Determination method of compressive strength: Measure according to the standard of GB/T6669-2008 compression permanent deformation of slow rebound foam polymer materials, use a universal strength testing machine to test, and analyze the performance curve image of the test results to obtain the compressive strength.

3. Energy absorption measurement method: Measure according to the standard of GB/T6669-2008 compression permanent deformation of slow rebound foam polymer materials, and use a universal strength testing machine to analyze the performance curve image of the test results to calculate the energy absorption.

Example 1

The polyurethane composite material for multipurpose comfortable shoe materials and its preparation method are implemented according to the following steps:

(1) Self-made shear thickening solution, the specific preparation method is: take PEG and SiO ₂ with a mass ratio of 3:1, stir them thoroughly and place them in a vacuum drying room at 25°C for 24 hours to remove air bubbles and obtain shear thickening solution. thickened liquid.

(2) Prepare shear thickening liquid capsules by literature method, dry at room temperature for later use;

Specifically: adopt the method of Xing Liu of Tianjin University of Technology to prepare shear thickening liquid capsules. The specific steps are as follows: drop self-made shear thickening fluid (STF) into liquid paraffin to form a water-in-oil emulsifier, and stir at 25° C. for 30 minutes. Add the hydrophilic surfactant to the sodium alginate solution and mix well, then slowly add the water-in-oil emulsifier. Mix for 20 minutes at 25°C to form a water-in-oil-in-water multiple emulsion. Draw the water-in-oil-in-water multiple emulsion into a small diameter syringe. The syringe was set as a micro-syringe pump with a drive speed of 10 μL/min, pushing it into the prepared calcium chloride solution to form spherical droplets. Rinse with deionized water and dry at room temperature.

(3) In parts by mass, 100 parts of material A (polyether polyol), 2 parts of foaming catalyst, 0.36 parts of deionized water, 3 parts of anti-yellowing agent, 0.19 parts of gel catalyst, hollow ball expandable beads 3 parts are mixed evenly with 3 parts of solid ball shear thickening liquid capsules to obtain matrix prefabricated material;

(4) Mix the matrix prefabricated material and B material (isocyanate) evenly in a mass ratio of 100:70, stir it mechanically for 6-10s, pour it into the mold quickly and flow evenly, and carry out compression molding. Open the mold and take it out after 2 minutes of foaming The material is cured at 20-28 degrees Celsius for 20 minutes to obtain the matrix material.

The obtained sample has smooth skin, uniform cells, low molding shrinkage, apparent density of 0.311g/cm ³ , compressive strength of 3.0888MPa, and energy absorption of 57.2162KJ/m ³ . It is a group with ideal effect in the examples of this patent, which maintains a moderate apparent density and obtains the maximum energy absorption effect at the same time.

Figure 1 is a schematic cross-sectional view of the prepared composite material. Adding hollow spherical expandable beads and solid spherical shear thickening liquid capsules to the polyurethane matrix are evenly distributed, synergistically regulating the apparent density of the matrix, while enhancing its compressive strength and energy absorption efficiency, without increasing the apparent density excessive.

Fig. 2 is a SEM scanning image of the polyurethane composite material prepared in this example, which characterizes its internal cell structure. Through observation, it can be found that the addition of hollow spherical expandable beads has a great influence on the shape of cells. After adding hollow spherical expandable beads, it is equivalent to introducing impurity nuclei into the system, which is conducive to the formation of fine cells for the adsorption of gas. When it is distributed on the cell wall, it becomes a state that the cell wall has a depression. This depression forms a small through hole. When a low-speed load is applied, the gas has enough time to escape from the through hole. When the load is withdrawn, it can Breathe in air to restore form. When the high-speed load is applied, the gas has no time to escape, which can provide a good energy-absorbing and shock-absorbing effect on the shoe material. Adding an appropriate amount of hollow spherical expandable beads can not only increase the cell density, but also have thicker cell walls, which have higher durability when faced with long-term or repeated loads.

The composite material prepared in Example 1 can ideally meet the requirements of multi-purpose comfortable shoe materials, that is, it can correspond to various usage scenarios and exhibit different usage effects. For example, in the jogging scene, the shoe material is moderately exhausted, absorbing shock and avoiding damage to the knees; in the competitive sports scene, the air is instantly locked, providing high rebound performance, and boosting speed. This embodiment relatively perfectly reaches the practical standard of one shoe with multiple functions, taking into account both density and energy absorption effect.

Example 2

The polyurethane composite material for multipurpose comfortable shoe materials and its preparation method are implemented according to the following steps:

(1) As shown in step (1) of Example 1, prepare a shear thickening solution, cool to room temperature for subsequent use;

(2) As shown in step (2) of Example 1, prepare shear thickening liquid capsules, and dry them at room temperature for later use;

(3) In parts by mass, 100 parts of material A (polyether polyol), 2 parts of foaming catalyst, 0.36 parts of deionized water, 3 parts of anti-yellowing agent, 0.19 parts of gel catalyst, hollow ball expandable beads 1 part is uniformly mixed with 3 parts of solid ball shear thickening liquid capsule to obtain matrix prefabricated material;

(4) Mix the matrix prefabricated material and B material (isocyanate) evenly in a mass ratio of 100:70, stir it mechanically for 6-10s, pour it into the mold quickly and flow evenly, and carry out compression molding. Open the mold and take it out after 2 minutes of foaming The material is cured at 20-28 degrees Celsius for 20 minutes to obtain the matrix material.

The obtained sample has smooth skin, uniform cells, low molding shrinkage, apparent density of 0.351g/cm ³ , compressive strength of 3.7067MPa, and energy absorption of 52.4489KJ/m ³ .

Compared with Example 1, the addition amount of the hollow spherical expandable beads is reduced, the apparent density is somewhat increased, and the energy absorption unit is reduced, and the energy absorption efficiency is slightly reduced. Embodiment 2 can also be applied to multi-purpose comfortable shoe materials, only compared with Embodiment 1, Embodiment 1 is better.

Example 3

The polyurethane composite material for shoe materials and its preparation method are implemented according to the following steps:

(1) As shown in step (1) of Example 1, prepare a shear thickening solution, cool to room temperature for subsequent use;

(2) As shown in step (2) of Example 1, prepare shear thickening liquid capsules, and dry them at room temperature for later use;

(3) In parts by mass, 100 parts of material A (polyether polyol), 2 parts of foaming catalyst, 0.36 parts of deionized water, 3 parts of anti-yellowing agent, 0.19 parts of gel catalyst, hollow ball expandable beads 3 parts are uniformly mixed with 5 parts of solid ball shear thickening liquid capsules to obtain matrix prefabricated material;

(4) Mix the matrix prefabricated material and B material (isocyanate) evenly in a mass ratio of 100:70, stir it mechanically for 6-10s, pour it into the mold quickly and flow evenly, and carry out compression molding. Open the mold and take it out after 2 minutes of foaming The material is cured at 20-28 degrees Celsius for 20 minutes to obtain the matrix material.

The obtained sample has smooth skin, uniform cells, low molding shrinkage, apparent density of 0.912g/cm ³ , compressive strength of 4.2586MPa, and energy absorption of 19.9390KJ/m ³ .

Compared with Example 1, the addition amount of the solid sphere shear thickening liquid capsule increases. Since the density of the shear thickening liquid capsule is much greater than that of the foam itself, when the amount of the shear thickening glue added is relatively large, it has a greater impact on the density of the matrix, and because of its position in the foam matrix, it is effective The foaming space is reduced, and the cells are the core of the energy absorption and shock absorption of the foam material, and finally the energy absorption efficiency is reduced.

Comparative example 1:

The preparation of polyurethane composite materials for shoe materials without adding hollow sphere expandable beads and solid sphere shear thickening liquid capsules is specifically implemented according to the following steps:

(1) As shown in step (1) of Example 1, prepare a shear thickening solution, cool to room temperature for subsequent use;

(2) As shown in step (2) of Example 1, prepare shear thickening liquid capsules, and dry them at room temperature for later use;

(3) In parts by mass, 100 parts of material A (polyether polyol), 2 parts of foaming catalyst, 0.36 parts of deionized water, 3 parts of anti-yellowing agent, and 0.19 parts of gel catalyst are mixed evenly to obtain a matrix prefabricated material;

(4) Mix the matrix prefabricated material and B material (isocyanate) evenly in a mass ratio of 100:70, stir it mechanically for 6-10s, pour it into the mold quickly and flow evenly, and carry out compression molding. Open the mold and take it out after 2 minutes of foaming The material is cured at 20-28 degrees Celsius for 20 minutes to obtain the matrix material.

The obtained sample has smooth skin, uniform cells, low molding shrinkage, apparent density of 0.258cm ³ , compressive strength of 2.7268MPa, and energy absorption of 24.754KJ/m ³ . In this comparative example, a blank substrate was prepared, and only the part of the polyurethane foam was reserved, and no other synergistic substances were added. The energy absorption effect of this material is limited. At the same time, the weakness of the polyurethane foam itself is not eliminated, and it is prone to stress softening under long-term loads, which shortens the service life.

Comparative example 2

The polyurethane composite material for shoe materials and its preparation method are implemented according to the following steps:

(1) As shown in step (1) of Example 1, prepare a shear thickening solution, cool to room temperature for subsequent use;

(2) As shown in step (2) of Example 1, prepare shear thickening liquid capsules, and dry them at room temperature for later use;

(3) In parts by mass, 100 parts of material A (polyether polyol), 2 parts of foaming catalyst, 0.36 parts of deionized water, 3 parts of anti-yellowing agent, 0.19 parts of gel catalyst, hollow ball expandable beads 0 part and 3 parts of solid sphere shear thickening liquid capsule are mixed uniformly to obtain matrix prefabricated material;

(4) Mix the matrix prefabricated material and B material (isocyanate) evenly in a mass ratio of 100:70, stir it mechanically for 6-10s, pour it into the mold quickly and flow evenly, and carry out compression molding. Open the mold and take it out after 2 minutes of foaming The material is cured at 20-28 degrees Celsius for 20 minutes to obtain the matrix material.

The obtained sample has smooth skin, concentrated distribution of some cells, small molding shrinkage, apparent density of 0.76g/cm ³ , compressive strength of 3.5924MPa, and energy absorption of 25.0071KJ/m ³ . On the basis of the blank matrix, only solid ball shear thickening liquid capsules are added, and its density and specific gravity are much larger than that of the polyurethane foam itself, which increases the apparent density of the overall composite material. Although the compressive strength has been enhanced, its weight The increase in the load for the application of competitive sports scenes, and as a daily casual shoe material, the exhaust effect has not been improved, but the weight load has increased, which has certain restrictions on the age of the audience.

Comparative example 3

The polyurethane composite material for shoe materials and its preparation method are implemented according to the following steps:

(1) As shown in step (1) of Example 1, prepare a shear thickening solution, cool to room temperature for subsequent use;

(2) As shown in step (2) of Example 1, prepare shear thickening liquid capsules, and dry them at room temperature for later use;

(3) In parts by mass, 100 parts of material A (polyether polyol), 2 parts of foaming catalyst, 0.36 parts of deionized water, 3 parts of anti-yellowing agent, 0.19 parts of gel catalyst, hollow ball expandable beads 3 parts are mixed evenly with the ratio of 0 part of solid ball shear thickening liquid capsule to obtain matrix prefabricated material;

(4) Mix the matrix prefabricated material and B material (isocyanate) evenly in a mass ratio of 100:70, stir it mechanically for 6-10s, pour it into the mold quickly and flow evenly, and carry out compression molding. Open the mold and take it out after 2 minutes of foaming The material is cured at 20-28 degrees Celsius for 20 minutes to obtain the matrix material.

The obtained sample has smooth skin, uniform cells, low molding shrinkage, apparent density of 0.211g/cm ³ , compressive strength of 2.037MPa, and energy absorption of 23.5864KJ/m ³ . Due to the addition of expandable beads, the closed cell ratio increases, the density of the composite material is greatly reduced, and the compressive strength is reduced. The adaptability to competitive sports scenes is reduced, and the scope of application scenarios is narrowed. It does not meet the ideal requirements of a shoe with multiple uses. .

Comparative example 4

The polyurethane composite material for shoe materials and its preparation method are implemented according to the following steps:

(1) As shown in step (1) of Example 1, prepare a shear thickening solution, cool to room temperature for subsequent use;

(2) As shown in step (2) of Example 1, prepare shear thickening liquid capsules, and dry them at room temperature for later use;

(3) In parts by mass, 100 parts of material A (polyether polyol), 2 parts of foaming catalyst, 0.36 parts of deionized water, 3 parts of anti-yellowing agent, 0.19 parts of gel catalyst, hollow ball expandable beads 3 parts are mixed evenly with 3 parts of solid ball shear thickening liquid capsules to obtain matrix prefabricated material;

(4) Mix the matrix prefabricated material and material B (isocyanate) evenly in a mass ratio of 100:75, stir it mechanically for 6-10 seconds, quickly pour it into the mold and flow evenly, and press the mold. After 2 minutes of foaming, the mold is opened and taken out The material is cured for 40 minutes at 20-28 degrees Celsius to obtain the matrix material.

The obtained sample had sunken skin, partly collapsed and turned yellow inside the cells, and felt chaffy. The apparent density was 0.573g/cm ³ , the compressive strength was 4.037MPa, and the energy absorption was 29.3762KJ/m ³ .

Compared with Example 1, this embodiment increases the addition ratio of material B. The amount of material B added determines the content of the hard segment. When material B increases, the hardness of the foam matrix increases, and the difficulty of foaming increases, resulting in an increase in density and compressive strength. At the same time, due to the relative excess of material B, the reaction with water is enhanced, causing the gel reaction speed to not keep up with the foaming reaction speed, which is easy to cause foam collapse, and heartburn due to prolonged aging time. Under this ratio, the cell structure is severely damaged, and the energy absorption effect is greatly reduced, which cannot meet the needs of appearance and use.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore The scope of protection of the present invention should be defined by the claims.

Claims (10)

1. A method for preparing polyurethane for a multi-purpose comfortable shoe material, which is characterized by comprising the following steps:

(1) Uniformly mixing the polyether polyol A, a foaming catalyst, deionized water, a yellowing resistant agent, a gel catalyst, hollow sphere expandable beads and solid sphere shear thickening fluid capsules according to a preset proportion to obtain a matrix pre-material;

(2) Uniformly mixing the matrix prefabricated material and the B material isocyanate according to a preset proportion, mechanically stirring for 6-10s, rapidly pouring into a mold, uniformly flowing, pressing, opening the mold after foaming is finished for 2-5 minutes, taking out the material, and curing at 20-28 ℃ to obtain the composite material.

2. The preparation method of claim 1, wherein in the step (1), the mass parts of each component are 100 parts of the material A, 2-4 parts of the foaming catalyst, 0.3-0.4 part of deionized water, 3-5 parts of the yellowing-resistant agent, 0.15-0.2 part of the gel catalyst, 1-5 parts of the hollow sphere expandable beads and 1-5 parts of the solid sphere shear thickening fluid capsule.

3. The preparation method according to claim 1, wherein the mass fraction of the material B in the step (2) is 60-75.

4. The method of claim 1, wherein step (1) comprises 3 parts of hollow sphere expandable beads and 3 parts of solid sphere shear thickening fluid capsules; and (3) 70 parts of material B in the step (2).

5. The preparation method of the solid sphere shear thickening fluid capsule according to claim 1, wherein the shear thickening fluid capsule is prepared by using a surfactant, a sodium alginate solution and a calcium chloride solution.

6. The process according to claim 1, wherein the expandable beads of hollow spheres used in the step (1) are one or more of the EXPANCEL series, DE series, UM115 series and UM116 series, and have an initial particle diameter of 6 to 10. Mu.m, and a minimum foaming temperature of 80 to 85 ℃.

7. The method according to claim 1, wherein the material a is one or more of polyether glycol or polyether triol; the material B is one or more of isocyanate or liquefied diphenylmethane diisocyanate.

8. A polyurethane composite for shoe materials prepared by the method according to any one of claims 1 to 7.

9. The use of the polyurethane composite for shoe materials as claimed in claim 8.

10. The use according to claim 9, in the field of energy absorbing footwear, including multi-use comfort footwear.

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