Coloured TPU foam material, preparation method and use thereof, as well as method for preparing shaped body, sheet and shoe material by using same

Abstract

Disclosed are a colored TPU foam material, a preparation method and a use thereof, as we as a method for preparing a shaped body, a sheet and a shoe material by using same. The colored TPU foam material is composed of colored foam particles or colored foam sheets; the concentration of a pigment in the colored foam particles or the colored foam sheets is 0.01-5 wt %; the pigment has the same concentration inside and outside the colored TPU foam material, and the colored TPU foam material has a hardness of shore A 5-65, a density of 0.05-0.5 g/cm.sup.3, and an average cell size of less than 100 m. The present invention has features such as a good internal and external color uniformity, no wrinkles being present on the surface, etc.

Claims

1. A method for preparing a color thermoplastic polyurethane (TPU) foam material which comprises color TPU foam particles; the color TPU foam particles have a pigment; a concentration of the pigment in the color TPU foam particles is 0.015 wt %, the method comprises the following steps: premixing the pigment with TPU particles, extruding the TPU particles premixed with the pigment, and then granulating the TPU particles premixed with the pigment underwater by using a pelletizer to obtain color TPU particles; immersing the color TPU particles in a high-pressure fluid until equilibrium is reached between the high-pressure fluid and the color TPU particles; after reaching the solubility equilibrium, heating and foaming the color TPU particles by placing the color TPU particles in a water bath or steam to obtain a semi-finished product of the color TPU foam particles; placing the semi-finished product into a closed container, flushing in high pressure air into the container to replace the high-pressure fluid with the high pressure air such that the semi-finished product of the color TPU foam particles shrinks uniformly to obtain a final product of the color TPU foam particles having a smooth surface; wherein the high pressure air has a pressure of 0.150.5 MPa and a temperature which is a room temperature; the color TPU foam material comprising the color TPU foam particles obtained through the above steps has a uniform concentration of the pigment from an inside of the color TPU foam material to an outer surface of the color TPU foam material; the color TPU foam material has a hardness of shore A 5-65, a density of 0.05-0.5 g/cm.sup.3, and an average cell size of less than 100 m.

2. A method for preparing a color thermoplastic polyurethane (TPU) foam material which comprises color TPU foam particles; the color TPU foam particles have a pigment; a concentration of the pigment in the color TPU foam particles is 0.015 wt %, the method comprises the following steps: premixing the pigment with TPU particles, extruding the TPU particles premixed with the pigment, and then granulating the TPU particles premixed with the pigment underwater by using a pelletizer to obtain color TPU particles; immersing the color TPU particles in a high-pressure fluid until a solubility equilibrium is reached between the high-pressure fluid and the color TPU particles, wherein the high-pressure fluid has a pressure of 110 MPa, and a temperature of 060 C.; after reaching the solubility equilibrium, heating and foaming the color TPU particles by placing the color TPU particles in a water bath or steam to obtain a semi-finished product of the color TPU foam particles; heating the semi-finished product of the color TPU foam particles using hot air, wherein a temperature of the hot air is 100-140 C.; placing the heated semi-finished product into a closed container, flushing in high pressure air or nitrogen into the container to replace the high-pressure fluid with the high pressure air or nitrogen such that the heated semi-finished product of the color TPU foam particles shrinks uniformly to obtain a final product of the color TPU foam particles having a smooth surface; wherein the high pressure air or nitrogen has a pressure of 0.150.5 MPa and a temperature which is a room temperature; the color TPU foam material comprising the color TPU foam particles obtained through the above steps has a uniform concentration of the pigment from an inside of the color TPU foam material to an outer surface of the color TPU foam material; the color TPU foam material has a hardness of shore A 5-65, a density of 0.05-0.5 g/cm.sup.3, and an average cell size of less than 100 m.

3. A method for preparing a color thermoplastic polyurethane (TPU) foam material which comprises a color TPU foam sheet; the color TPU foam sheet has a pigment; a concentration of the pigment in the color TPU foam sheet is 0.015 wt %, the method comprises the following steps: premixing the pigment with TPU articles, extruding the TPU particles premixed with the pigment, and then casting or molding the TPU particles premixed with the pigment into a color TPU sheet; immersing the color TPU sheet in a high-pressure fluid until a solubility equilibrium is reached between the high-pressure fluid, and the color TPU sheet, wherein the high-pressure fluid has a pressure of 110 MPa, and a temperature of 060 C.; after reaching the solubility equilibrium, heating and foaming the color TPU sheet by placing the color TPU sheet in a water bath or steam to obtain a semi-finished product of the color TPU foam sheet; placing the semi-finished product into a closed container, flushing in high pressure air into the container to replace the high-pressure fluid with the high pressure air such that the semi-finished product of the color TPU foam sheet shrinks uniformly to obtain a final product of the color TPU foam sheet having a smooth surface; wherein the high pressure air has a pressure of 0.150.5 MPa and a temperature which is a room temperature; the color TPU foam material comprising the color TPU foam sheet obtained through the above steps has a uniform concentration of the piggy ent from an inside of the color TPU foam material to an outer surface of the color TPU foam material; the color TPU foam material has a hardness of shore A 5-65, a density of 0.05-0.5 g/cm.sup.3, and an average cell size of less than 100 m.

4. The method of claim 1, wherein the high-pressure fluid is as CO.sub.2 fluid, a solubility of the high-pressure fluid in the color TPU particles is 830 wt %.

5. The method of claim 2, wherein the high-pressure fluid is a CO.sub.2 fluid, a solubility of the high-pressure fluid in the color TPU particles is 830 wt %.

6. The method of claim 3, wherein the high-pressure fluid is a CO.sub.2 fluid, a solubility of the high-pressure fluid in the color TPU sheet is 830 wt %.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a optical schematic view of the yellow TPU foam particles prepared in Example 1.

(2) FIG. 2 is a optical schematic view of the section of yellow TPU foam particles prepared in Example 1.

(3) FIG. 3 is a electron microscope schematic view of the section of yellow TPU foam particles prepared in Example 1.

(4) FIG. 4 is a optical schematic view of the yellow TPU foam particles prepared in Comparative Example 1.

(5) FIG. 5 is a optical schematic view of the low TPU foam particles prepared in Comparative Example 3.

(6) FIG. 6 is a optical schematic view of the yellow TPU foam particles of a molded product prepared in Example 5.

(7) FIG. 7 is a optical schematic view of the yellow/white TPU mixed particles of a molded product prepared in Example 5.

(8) FIG. 8 is an optical schematic diagram of the process for preparing 7 colored TPU foam wafer embodiment.

DETAILED DESCRIPTION OF THE INVENTION

(9) To further explain the technical solution of the present invention, the present invention is explained in detail through the following specific embodiments.

Example 1

(10) The TPU particles (produced by Ningbo Jinsul) and 1 wt % yellow organic pigment (Permanent yellow HR) were dry blended by the extruder, an underwater pelletizer and then that can be made into a diameter of 2 mm, an aspect ratio of 1.5 ellipsoid TPU particles. The particles are placed in an autoclave, use the low-temperature high-pressure CO.sub.2 fluid dipping TPU particles at high pressure, and the fluid CO.sub.2 dissolved in the TPU resin particles that reach to equilibrium. Placed the impregnated TPU particles in a water bath or steam heated to foam, obtained color TPU foam particles marked as B1. Placed the TPU foam particles as 81 at room temperature, high-pressure air contained in the pressure to obtain the yellow TPU foam particles marked as 82, Table 1 is Example 1 related process parameters. Studies have shown that the density of prepared yellow TPU foam particles is 0.18 g/cm.sup.3, a hardness of A15. Shown in FIG. 1, obtained yellow TPU foam particles as a single ellipsoidal, smooth surface, there is no obvious shrinkage marks. Shown in FIG. 2, obtained the yellow TPU foam particles as a 100% closed cell structure, an average cell size of 15 microns. Shown in FIG. 3, the interface section yellow TPU obtained expanded particles are yellow, and the yellow pigment is uniformly distributed in the inner and outer materials.

Comparative Example 1

(11) In addition to the TPU foam particles were not contained in the pressure treatment, the other operation is the same as in Example 1, the density of prepared yellow TPU foam particles is 0.45 g/cm.sup.3. Shown in FIG. 4, the surface of prepared TPU foamed particles occurs significant wrinkles and a large area of the depression.

Comparative Example 2

(12) Reference the process of CN10229709A for preparing the color TPU foam particles. Placed the yellow TPU particles into the autoclave of temperature is 120 C., through the high-pressure CO.sub.2 fluid at pressure of 8 MPa, and impregnated TPU particles for 1 h, 2 h, 3 h, 4 h, 6 h, 12 h. Then rapid relief-pressure to obtain TPU foam material. Prepared the TPU foam material was irregular lumps or flakes, and the individual TPU foam particle can not be distinguished, while the large size cell structure of the sample was observed to appear on the surface. Whereby, impregnated for 1 h, 2 h, 3 h, 4 h to foam which obtained irregularly TPU foam was pale yellow, density respectively was 0.52, 0.54, 0.48, 0.45 g/cm.sup.3. Wherein impregnated for 6 h, 12 h to obtain the irregularly TPU foam was dark yellow. It may be described that TPU resins occurs chemically degrade, the density of the prepared TPU foam was 0.61 g/cm.sup.3.

Comparative Example 3

(13) Reference W02005/066250, W02007/082838, W020101136398 for preparing color TPU foam particles. Placed the yellow TPU particles and the dispersant into the autoclave in a water bath with stirring, the yellow TPU particles suspended in a water bath, and the bath temperature was 120 C. Through 20% of the butane being a blowing agent, impregnated yellow TPU particles were 1 h, 2 h, 3 h, 4 h under stirring state, and then rapidly relieving to obtain TPU foam particles material. As shown in FIG. 5, wherein impregnated the TPU particles for 1 h and 2 h that obtained the TPU foam particles was non-uniform light yellow, the density of 0.20 g/cm.sup.3. Impregnated the TPU particles for 3 h and 4 h that obtained the TPU foam particles was non-uniform dark yellow. It may be described that TPU resins occurs chemically degrade, the density of the prepared TPU foam was 0.18 g/cm.sup.3.

Comparative Example 4

(14) Reference the process of CN103642200A for preparing the color TPU foam particles. Placed the yellow TPU particles into the autoclave of temperature is 120 C., through the high-pressure CO.sub.2 fluid at pressure of 8 MPa, and impregnated TPU particles for 1 h, 2 h, 3 h, 4 h. Then rapid relief-pressure to obtain TPU foam material. Whereby, impregnated the TPU particles for 1 h and 2 h that obtained the TPU foam particles was non-uniform light yellow, the density of 0.47 g/cm.sup.3. Impregnated the TPU particles for 3 h and 4 h that obtained the TPU foam particles was non-uniform dark yellow. It may be described that TPU resins occurs chemically degrade, the density of the prepared TPU foam was 0.51 g/cm.sup.3.

Example 2

(15) In addition to changing the source of TPU resins (Purchase from Ningbo Golden Harvest, Yantai Wanhua, Dow Chemical Company, Bayer Company), granulation size and operating conditions, the other operation that is the same as in Example 1. Prepared yellow TPU foam particles are both smooth surface, no significant contraction. Both inside and outside the color TPU foam particles which having a uniform pigment distribution that can be observed from the incision. Specific data are shown in Table 1.

Example 3

(16) In addition to changing the amount of the yellow organic pigment 0.1, 0.5, 1, 2.5 wt %, the other operation is the same as in Example 1. Prepared yellow TPU foam particles are both smooth surface, no significant contraction. Both inside and outside the color TPU foam particles which having a uniform pigment distribution that can be observed from the incision. Specific data are shown in Table 2.

Example 4

(17) In addition to content of the pigment is increased to 3 wt %, the TPU foam particles B1 continued foaming by hot air for 30 s, the hot air temperature is 100-140 C., to obtain B2. And after the pressure of the high pressure air contained to prepare B3, the other operation is the same as in Example 1. Prepared yellow TPU foam particles are both smooth surface, no significant contraction. Both inside and outside the color TPU foam particles which having a uniform pigment distribution that can be observed from the incision. Specific data are shown in Table 3.

Example 5

(18) Placed the yellow TPU foam particles as B2 or B3 in the EPP foam particles molding machine of the shoe mold, then close the mold. And the water vapor was bubbled into the mold to heat the mold, then cooling the mold for cold water, drainage, blowing, open mold, to obtain the yellow TPU foam particles molded soles. Wherein the steam temperature is 138 C., the heating time for 40 s. As shown in FIG. 6, the yellow TPU foam particles molded material have a good interfacial on and the pigment distribution in the surface of the molding. Tests show that: the average density of the yellow TPU foam particles molded of soles is 0.29 g/cm.sup.3, a hardness of A42.

Example 6

(19) The 20 wt % yellow and 80 wt % red and white TPU foam particles injected into the EPP foam particles molding machine of the shoe mold, then close the mold. And the water vapor was bubbled into the mold to heat the mold, then cooling the mold for cold water, drainage, blowing, open mold, to obtain the yellow TPU foam particles molded soles. Wherein the steam temperature is 145 C., the heating time for 10 s. As shown in FIG. 7, the mixed color TPU foam particles molded material have a good interfacial bond, and the pigment did not occur significantly migration in the TPU foam particles. Tests show that: the average density of the mixed color TPU foam particles molded of soles is 0.36 g/cm.sup.3, a hardness of A45.

Example 7

(20) The TPU particles (produced by Dow Chemical) and 1 wt % pigment were dry blended by the extruder, molded into a color TPU sheet which having a thickness of 2 mm, and cut into wafers of 20 mm diameter. The color TPU wafers are placed in an autoclave, use the low-temperature, high-pressure CO.sub.2 fluid dipping TPU particles at high pressure, and the fluid CO.sub.2 dissolved in the TPU resin particles that reach to equilibrium. Placed the impregnated TPU particles in a water bath or steam heated to foam, obtained yellow TPU foam particles marked as B1. Placed the TPU foam particles as B1 at room temperature, high-pressure air contained in the pressure to obtain the yellow TPU foam discs marked as B2. In addition to changing the kind of the color of the pigment, the content of titanium dioxide is 3 wt %, other process parameters are the same as in Example 1. FIG. 8 shows the optical photo of the addition of titanium dioxide, carbon black, phthalocyanine blue, pigment fast scarlet, permanent yellow pigments, fluorescent green color obtained TPU foam. As shown in FIG. 8, prepared TPU foam had no significant contraction marks. Both inside and outside the color TPU foam particles which having a uniform pigment distribution that can be observed from the incision. Table 4 shows the color TPU wafer performance.

Comparative Example 5

(21) In addition to the pigment is not added, the other operation is the same as Example 7. Prepared TPU foam are smooth surface, and no significant contraction of white TPU foam particles material. The color of TPU foam sheet obtained from Comparative Example 5 is dark that compared to the TPU foam sheet was added with titanium dioxide obtained from Example 7.

Example 8

(22) In addition to the thickness of yellow TPU cast sheet is 15 mm, the other operation is the same as Example 7. Prepared the thickness of yellow Further, prepared TPU foam material was no obvious shrinkage mark, and both inside and outside the color TPU foam particles which having a uniform pigment distribution.

Example 9

(23) Using the chopper with the rubber sponge on the hardness of A20, a thickness of 30 mm yellow TPU foam sheet which were split, and the thicknesses of TPU foam sliced is 0.2, 0.5, 1, 2, 5, 10 mm. Prepared the yellow TPU foam sliced was color uniform, homogeneous in structure, with smooth surface.

Example 10

(24) Placed the thickness of 8 mm yellow TPU foam sheet into a temperature of 155 C. insoles mold, merging mold, hot pressing, water-cooled, open the mold, prepared yellow TPU foam insoles. The resulting yellow TPU foam shoes was colorful, homogeneous in structure, no significant contraction marks.

Example 11

(25) Placed the upper thickness of 10 mm, under thickness of 3 mm trapezoidal fluorescent blue TPU foam insoles into a temperature of 175 C. shoe mold, merging mold, hot pressing, water-cooled, open the mold, prepared fluorescent blue TPU sports shoes in the end. The resulting fluorescent blue TPU foam shoe was colorful, homogeneous in structure, no significant contraction marks.

(26) TABLE-US-00001 TABLE 1 Preparation of process parameters and performance indicators of color TPU foam particles as shown in Particles Impregation Foaming Cell Color Example Size Conditions Time Pressure Density Hardness Size Degree Example 1 2 mm, 1.5 5 MPa/0 C. 30 s 0.20 MPa 0.21 g/cm.sup.3 A21 20 m moderation Example 2 1 mm, 1.5 3 MPa/50 C. 60 s 0.15 MPa 0.32 g/cm.sup.3 A32 18 m moderation 0.5 mm, 1.5 1 MPa/50 C. 60 s 0.15 MPa 0.5 g/cm.sup.3 A64 6 m moderation 2 mm, 3 10 MPa/0 C. 20 s 0.40 MPa 0.09 g/cm.sup.3 A7 72 m shallower 3 mm, 1.5 5 MPa/30 C. 10 s 0.50 MPa 0.35 g/cm.sup.3 A37 20 m moderation 4 mm, 1.5 8 MPa/60 C. 5 s 0.20 MPa 0.28 g/cm.sup.3 A29 30 m moderation 5 mm, 1.5 10 MPa/60 C. 30 s 0.20 MPa 0.18 g/cm.sup.3 A16 40 m moderation

(27) Performance Indicators of Different Yellow Pigment Content of Color TPU Foam Particles

(28) TABLE-US-00002 Pigment Average Color Content Density Hardness Cell Size Degree 0.1 wt % 0.22 g/cm.sup.3 A20 17 m shallower 0.5 wt % 0.20 g/cm.sup.3 A17 18 m moderation 1 wt % 0.18 g/cm.sup.3 A15 15 m moderation 2 wt % 0.16 g/cm.sup.3 A14 14 m moderation 5 wt % 0.12 g/cm.sup.3 A10 12 m darker

(29) TABLE-US-00003 TABLE 3 The effects of hot air foam secondary or not on the performance parameters of TPU foam particles Hot air foam Average Color or not Density Hardness Cell Size Degree Example 1, 0.18 g/cm.sup.3 A15 15 m moderation none Example 4, yes 0.07 g/cm.sup.3 A6 78 m moderation

(30) TABLE-US-00004 TABLE 4 The parameters of using different types pigment prepared color TPU foam sheet Average Color Pigment Color Density Hardness Cell Size Degree permanent 0.18 g/cm.sup.3 A15 15 m moderation yellow HR permanent 0.20 g/cm.sup.3 A17 20 m moderation orange RL pigment fast 0.16 g/cm.sup.3 A15 18 m moderation scarlet 2R phthalocyanine 0.17 g/cm.sup.3 A13 17 m moderation blue BGS fluorescent green 0.19 g/cm.sup.3 A13 17 m moderation LP-9002 carbon black 0.21 g/cm.sup.3 A21 20 m moderation titanium 0.25 g/cm.sup.3 A25 22 m uniform white dioxide No added 0.20 g/cm.sup.3 A17 20 m white, darker pigment

(31) The foregoing embodiments and the drawings are not limited to the shape and pattern of the product of the present invention, one of ordinary skill in the art relevant to any of its variations or modifications made to the appropriate, are to be regarded as not departing from the scope of the present invention patent.