CN110938250A

CN110938250A - Foamed sole and preparation method thereof

Info

Publication number: CN110938250A
Application number: CN201911112509.4A
Authority: CN
Inventors: 章勤华; 卢鑫
Original assignee: Zhejiang Heng Cheng Shoes Co Ltd
Current assignee: Zhejiang Heng Cheng Shoes Co Ltd
Priority date: 2019-11-14
Filing date: 2019-11-14
Publication date: 2020-03-31

Abstract

The invention discloses a foamed sole which is prepared from the following raw materials in parts by weight: EVA, OBC, maleic anhydride grafted EVA, graphene oxide flame retardant, talcum powder, wear-resisting agent, stearic acid, zinc stearate, zinc oxide, flowing agent, crosslinking agent and foaming agent; the invention adopts the raw materials of the foaming sole material rice and the special preparation process of the foaming sole material rice, the tearing strength of the prepared sole outsole reaches 13.2N/mm, is about equal to one time of the tearing strength of the sole in the prior art, the preparation process is simple, the beneficial effects of improving the tearing strength of the sole, reducing the length of the grinding trace of the sole, improving the flame retardant property of the sole and the like are realized under the condition of not influencing the efficiency and the cost of preparing the sole, and the unexpected effect is obtained.

Description

Foamed sole and preparation method thereof

Technical Field

The invention relates to the technical field of sole preparation, in particular to a foamed sole and a preparation method thereof.

Background

In the current consumer market, shoe materials are the most important application field of domestic EVA resin. Because the EVA resin blended foaming product has the performances of softness, good elasticity, chemical corrosion resistance and the like, the EVA resin blended foaming product is widely applied to soles and interior materials of medium and high-grade travel shoes, climbing shoes, slippers and sandals.

The tear strength of the shoe sole manufactured by the manufacturing method can reach 7.3N/mm to the maximum and is higher than the standard requirement, but because the EVA shoe sole is commonly used in the midsoles of jogging, casual shoes and foot training shoes, even if the tear strength is higher than the standard, the tear strength is far from insufficient in actual use and is not wear-resistant, and particularly on a court, if the quality of the court is general, the service life of the shoe sole is very short.

Disclosure of Invention

The embodiment of the application solves the problem of poor tear strength of the sole in the prior art by providing the preparation method of the foamed sole.

The embodiment of the application provides a foaming sole, which is prepared from the following raw materials in parts by weight:

the health-care food is further prepared from the following raw materials in parts by weight:

further, the preparation method of the graphene oxide flame retardant comprises the following steps:

(a) dispersing graphite oxide in NaOH aqueous solution, carrying out ultrasonic treatment on the solution for 15-40 minutes, and gradually stripping and dissolving the graphite oxide to form stable graphite oxide colloidal solution;

(b) dropwise adding a melamine salt aqueous solution into the graphite oxide colloidal solution, reacting the mixed solution for 10-60 minutes under strong stirring, then continuously stirring at a low speed for 10-60 minutes to separate out precipitates, and carrying out centrifugal separation and washing for multiple times by using water until the pH value of the washing aqueous solution is 6.5-7.5;

(c) and finally, vacuum drying the separated solid product in a vacuum drying oven at 50-75 ℃ for 5-24h, grinding and sieving with a 400-mesh sieve to obtain the graphene oxide flame retardant.

(a) dispersing 1g of graphite oxide in 100mL of 0.04mol/L NaOH solution, carrying out ultrasonic treatment for 25min at the ultrasonic frequency of 40KHz, and gradually stripping and dissolving the graphite oxide to form a stable graphite oxide colloidal solution;

(b) then, 30mL of 10mol/L melamine salt solution is dropwise added into the graphite oxide colloidal solution, the mixed solution is reacted for 30 minutes under strong stirring, then the mixed solution is continuously stirred at a low speed for 40 minutes, precipitates are separated out, and the mixed solution is filtered, centrifuged and washed with water for multiple times until the pH value of the washing water solution is 7-7.5;

(c) and finally, vacuum drying the separated solid product in a vacuum drying oven at 60 ℃ for 12h, grinding and sieving with a 400-mesh sieve to obtain the graphene oxide flame retardant.

Further, the melamine salt is selected from any one of melamine cyanurate, melamine phosphate, melamine polyphosphate, melamine borate, melamine oxalate and melamine phthalate.

Further, the cross-linking agent is a cross-linking agent TRIGNOX17, the foaming agent is foaming agent AC, the OBC is OBC 9107 or OBC 9077, the wear-resisting agent is wear-resisting agent NM-2, the stearic acid is stearic acid 1840, and the flowing agent is flowing agent 2500.

A preparation method of a foamed sole specifically comprises the following steps:

step (1): pouring talcum powder, an anti-wear agent, stearic acid, zinc stearate, zinc oxide and a flowing agent into an internal mixer, pouring EVA, OBC, maleic anhydride grafted EVA and a graphene oxide flame retardant into the internal mixer, adjusting the air pressure to be 0.75-0.8MPa and the circulating water pressure to be 0.15-0.2MPa, carrying out first internal mixing and turning, putting the crosslinking agent and the foaming agent into the same feeding bag, shaking and stirring uniformly, and then putting into the internal mixer; after the materials are subjected to secondary banburying and turning, opening the banbury mixer, and pouring the mixed materials into a roller hopper;

step (2): conveying the materials in the roller sliding hopper to an open mill immediately, dumping the materials on a roller table, adjusting the temperature of the open mill to 65-75 ℃, adjusting the roller distance to 6mm, and tabletting and dropping the materials into a material tray after mixing; adjusting the roller distance to 1.6mm, and turning twice to bundle thin; adjusting the roller distance to 2.6mm, adjusting the other direction of the falling material, pushing the falling material into a roller table, mixing, beating a triangular wrapping sheet, and then falling into a material tray; adjusting the roller distance to 6mm, mixing the thin materials on a roller table, sequentially cutting the materials and winding the rolls, and immediately conveying the materials to a granulator;

extruding and granulating the material by a screw in a granulator, wherein the temperature of the screw is set to be 80 ℃ in an A area, 80 ℃ in a B area, 85 ℃ in a C area, 85 ℃ in a D area and 90 ℃ in an E area; the extrusion frequency conversion speed is set as 45Hz of main feeding, 36Hz of a nip roll and 16Hz of cutting; the granules immediately enter a four-stage cyclone cooling barrel and pass through a vibrating screen to obtain the foaming sole material rice with uniform granules and the temperature lower than 50 ℃;

pouring foaming shoe sole material rice into a foaming mold, closing the mold, raising the temperature for foaming, controlling the temperature to be 170-174 ℃ for 240-300 seconds, immediately taking out a half-finished shoe sole after automatically opening the mold, cooling for 12 hours, removing unqualified half-finished shoe sole products with material shortage, material death, edge explosion or length error exceeding +/-2 mm, roughening the qualified half-finished shoe sole products through a wheel, and grinding off the surface skin at the bottom and side surfaces of the half-finished shoe sole products to obtain small foaming half-finished products;

and (5): putting the small foamed semi-finished product into an oil pressure die, closing the die, conveying the die into a heating station of an oil pressure forming machine, heating and forming the die at the temperature of 170-174 ℃ for 240-300 seconds; then pulling out the die, switching to a cooling station, and cooling by water for 240-300 seconds; pulling out and opening the mould, pulling out the product from the mould, and placing the product on an inspection platform; and removing unqualified soles with broken clamping, material shortage and outer wall wrinkling, and trimming and finishing qualified products to obtain the foamed soles.

Further, the concrete steps of the first banburying and stirring are as follows: adjusting the internal mixing to 80 ℃, turning materials for the first time, and cleaning the inner wall of the internal mixer; when the banburying temperature is raised to 85 ℃, turning materials for the second time; when the banburying temperature is increased to 90 ℃, turning materials for the third time; when the banburying temperature is increased to 95 ℃, turning materials for the fourth time; and (5) turning materials for the fifth time when the banburying temperature is increased to 100 ℃.

Further, the second banburying and stirring comprises the following specific steps: when the banburying temperature is increased to 107 ℃, turning materials for the sixth time; and when the banburying temperature rises to 113 ℃, turning materials for the seventh time, and banburying for 2 minutes.

One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

1. the invention adopts the raw materials of the foaming sole material rice and the special preparation process of the components thereof, the tearing strength of the prepared sole outsole reaches 13.2N/mm, is approximately equal to one time of the tearing strength of the sole in the prior art, the length of the prepared sole grinding mark is 4.6mm, which is far less than the national standard requirement of the common foaming sole of 9mm, and the unexpected effect is obtained.

2. The graphene oxide flame retardant selected by the invention is self-made, loose graphite oxide is dispersed in alkaline solution to form a single-atom-thickness segment of the graphene oxide, a lamellar layer of the graphene oxide flame retardant contains a plurality of oxygen-containing groups, has higher specific surface energy, good hydrophilicity and mechanical properties, has good dispersion stability in water and most polar organic solvents, and the graphene oxide has negative charges, has hydroxyl groups on the surface and can be stripped after being intercalated by small molecules such as amine salt and the like, so that the intercalated graphene oxide is obtained.

3. According to the invention, the melamine salt serving as a flame retardant reacts with the graphite oxide to obtain the novel flame retardant of the melamine salt intercalated graphene oxide, so that not only is the tear strength of the composite material improved, but also the flame retardant is better dispersed in the composite material, and the flame retardant property is improved.

4. The preparation method disclosed by the invention is simple in preparation process, and the beneficial effects of improving the tear strength of the sole, reducing the length of the grinding mark of the sole, improving the flame retardant property of the sole and the like are realized under the condition of not influencing the efficiency and the cost for preparing the sole, so that unexpected effects are obtained.

Detailed Description

In order to better understand the technical solutions, the technical solutions will be described in detail with reference to the description and the specific embodiments.

The following are a summary of the raw material compositions of the examples and comparative examples, resulting in table 1:

TABLE 1

Example 1

The embodiment of the application provides a preparation method of a foamed sole, which sequentially comprises the following steps:

preparing a graphene oxide flame retardant:

(a) dispersing 1g of graphite oxide in 10mL of 0.04mol/L NaOH solution, carrying out ultrasonic treatment on the solution for 25min at the ultrasonic frequency of 40KHz, and gradually stripping and dissolving the graphite oxide to form stable colloidal solution;

(b) then, 30mL of 10mol/L aqueous solution of melamine phosphate is dropwise added into the graphite oxide colloidal solution, the mixed solution is reacted for 30 minutes under strong stirring, then the mixed solution is continuously stirred at a low speed for 40 minutes, precipitates are separated out, and the mixed solution is filtered, centrifuged and washed with water for multiple times until the pH value of the washing aqueous solution is 7-7.5;

Preparing foamed soles

Step (1): pouring talcum powder, a wear-resistant agent, stearic acid, zinc stearate, zinc oxide and a flowing agent into an internal mixer, pouring EVA, OBC, maleic anhydride grafted EVA and a graphene oxide flame retardant into the internal mixer, adjusting the air pressure to be 0.75-0.8MPa and the circulating water pressure to be 0.15-0.2MPa, adjusting the internal mixing to 80 ℃, turning materials for the first time, and cleaning the inner wall of the internal mixer; when the banburying temperature is raised to 85 ℃, turning materials for the second time; when the banburying temperature is increased to 90 ℃, turning materials for the third time; when the banburying temperature is increased to 95 ℃, turning materials for the fourth time; when the banburying temperature is increased to 100 ℃, turning materials for the fifth time; putting the cross-linking agent and the foaming agent into the same feeding bag, shaking and stirring uniformly, and then feeding into an internal mixer; when the banburying temperature is increased to 107 ℃, turning materials for the sixth time; when the banburying temperature is increased to 113 ℃, turning over materials for the seventh time, banburying for 2 minutes, opening the banbury mixer, and pouring the well-mixed materials into a roller hopper;

The tearing strength of the finished product sole prepared by the method is 13.2N/mm; the length of the grinding crack is 4.6 mm; the dimensional shrinkage was 0.5%; the combustion rating V-0.

Example 2

In this example, the preparation method of the foamed shoe sole was the same as that in example 1, except that:

the raw materials varied in composition (see table 1 for details).

The tearing strength of the finished product sole prepared by the method is 11.6N/mm; the length of the grinding crack is 5.7 mm; the dimensional shrinkage was 1.1%; combustion grade V-1.

Example 3

the raw materials varied in composition (see table 1 for details).

The tearing strength of the finished product sole prepared by the method is 13.1N/mm; the length of the grinding crack is 4.6 mm; the dimensional shrinkage was 0.8%; the combustion rating V-0.

Example 4

the raw materials varied in composition (see table 1 for details).

The tearing strength of the finished product sole prepared by the method is 13.1N/mm; the length of the grinding crack is 5 mm; the dimensional shrinkage was 0.9%; the combustion rating V-0.

Comparative example a:

in this comparative example, the foamed sole was prepared in the same manner as in example 1, except that:

the preparation process of the graphene oxide flame retardant is lacked, and the raw materials are different in composition (detailed in Table 1).

The tearing strength of the finished product sole prepared by the method is 7.8N/mm; the length of the grinding crack is 8.7 mm; the dimensional shrinkage was 2.4%, which was flammable.

Comparative example B:

The tearing strength of the finished product sole prepared by the method is 8.9N/mm; the length of the grinding crack is 7.1 mm; the dimensional shrinkage was 1.8%, and the flame rating was HB.

Comparative example C:

The tearing strength of the finished product sole prepared by the method is 6.7N/mm; the length of the grinding crack is 10.3 mm; the dimensional shrinkage was 4.5% and the flame rating was V-2.

Comparative example D:

The tearing strength of the finished product sole prepared by the method is 6N/mm; the length of the grinding crack is 9.3 mm; the dimensional shrinkage was 2.9%, which was flammable.

The data of examples 1 to 4 and comparative examples A/B/C/D are collated to give the following Table 2 (Note: tear Strength measured in accordance with GB/T529, abrasion scar Length measured in accordance with GB/T3903.2, dimensional shrinkage measured in accordance with 70 ℃ C. for 40 minutes, Combustion rating measured in accordance with UL 94):

TABLE 2

The fire rating is 4 grades, HB, V-2, V-1, V-0, where V-0 is most preferred and "/" indicates no fire rating because of the combustibles.

From experimental data, compared with comparative example A, in example 1, the graphene oxide flame retardant is not used in the comparative example A, and all performances of example 1 are better than those of the comparative example A; compared with the comparative example B, the graphene oxide flame retardant is replaced by the graphene oxide and the melamine phosphate in the comparative example B, and all performances in the example 1 are superior to those in the comparative example B; compared with the comparative example C, the comparative example C replaces the graphene oxide flame retardant with melamine phosphate, and the performances of the example 1 are superior to those of the comparative example C; compared with the comparative example D, the comparative example D is not added with maleic anhydride grafted EVA, the graphene oxide flame retardant and more added with graphene oxide, and all performances of the example 1 are superior to those of the comparative example D.

The above description is only an embodiment utilizing the technical content of the present disclosure, and any modification and variation made by those skilled in the art can be covered by the claims of the present disclosure, and not limited to the embodiments disclosed.

Claims

1. The foaming sole is characterized by being prepared from the following raw materials in parts by weight:

2. the foamed sole according to claim 1, which is prepared from the following raw materials in parts by weight:

3. the foamed shoe sole according to claim 2, wherein the graphene oxide flame retardant is prepared by a method comprising the following steps:

4. The foamed shoe sole according to claim 3, wherein the graphene oxide flame retardant is prepared by a method comprising the following steps:

5. The foamed shoe sole according to claim 4, wherein the melamine salt is selected from any one of melamine cyanurate, melamine phosphate, melamine polyphosphate, melamine borate, melamine oxalate and melamine phthalate.

6. The foamed shoe sole of claim 5, wherein said cross-linking agent is selected from the group consisting of TRIGNOX17, said foaming agent is selected from the group consisting of foaming agent AC, said OBC is selected from the group consisting of OBC 9107 and OBC 9077, said anti-wear agent is selected from the group consisting of anti-wear agent NM-2, said stearic acid is selected from the group consisting of stearic acid 1840, and said flow agent is selected from the group consisting of flow agent 2500.

7. The method for preparing a foamed sole according to any one of claims 1 to 6, comprising the following steps:

8. The preparation method of the foamed sole according to claim 7, wherein the first banburying and turning comprises the following specific steps: adjusting the internal mixing to 80 ℃, turning materials for the first time, and cleaning the inner wall of the internal mixer; when the banburying temperature is raised to 85 ℃, turning materials for the second time; when the banburying temperature is increased to 90 ℃, turning materials for the third time; when the banburying temperature is increased to 95 ℃, turning materials for the fourth time; and (5) turning materials for the fifth time when the banburying temperature is increased to 100 ℃.

9. The preparation method of the foamed sole according to claim 7, wherein the second banburying and stirring comprises the following specific steps: when the banburying temperature is increased to 107 ℃, turning materials for the sixth time; and when the banburying temperature rises to 113 ℃, turning materials for the seventh time, and banburying for 2 minutes.