A sole material for casual shoes and its preparation method

Abstract

The present invention discloses a sole material for casual shoes and a preparation method thereof, which are prepared from the following parts by weight: EVA: 30-80 parts, modified polyborosiloxane: 2-15 parts, filler: 5-20 parts, heat stabilizer: 0.5-5 parts, zinc-containing compound: 0.2-5 parts, foaming agent: 0.5-10 parts, crosslinking agent: 0.5-5 parts; the modified polyborosiloxane is formed by the reaction of a polysiloxane with a hydroxyl group at the end, boric acid, a dianhydride compound, and a dibromoether compound. In the solution of the present invention, during the blending process of the modified polyborosiloxane and EVA, the melt index is better, the fluidity is better, and the compatibility is better. And the mechanical properties are also improved.

Description

Technical Field

[0001] The present invention relates to the field of polymers, and more specifically to a sole material for casual shoes. Background Art

[0002] In the prior art, the soles of most casual shoes are made of EVA material. In order to improve performance, EVA is usually blended and modified with other materials. Currently in the market, polyborosiloxane, as a strain rate-sensitive intelligent material, is an organosilicon polymer material formed by incorporating B element into the Si-O-Si main chain of polysiloxane polymer. It has unique viscoelasticity, that is, the viscosity increases rapidly with the increase of shear rate. This extremely special fluid behavior endows polyborosiloxane with excellent buffering and shock absorption performance. As an excellent modifier, it is often used for the modification of EVA and blended with EVA. However, due to the poor compatibility between polyborosiloxane and EVA material, compatibilizers often need to be added to improve their compatibility. But as the addition amount of polyborosiloxane increases, the compatibilization effect brought by the compatibilizer will also become worse. Therefore, there is an urgent need for a modified material with good compatibility between EVA and polyborosiloxane as the sole material for casual shoes. Summary of the Invention

[0003] Aiming at the deficiencies existing in the prior art, the purpose of the present invention is to provide a sole material for casual shoes.

[0004] To achieve the above purpose, the present invention provides the following technical solutions:

[0005] A sole material for casual shoes,

[0006] which is prepared from the following parts by weight:

[0007] EVA: 30 - 80 parts

[0008] Modified polyborosiloxane: 2 - 15 parts

[0009] Filler: 5 - 20 parts

[0010] Heat stabilizer: 0.5 - 5 parts

[0011] Zinc-containing compound: 0.2 - 5 parts

[0012] Blowing agent: 0.5 - 10 parts

[0013] Crosslinking agent: 0.5 - 5 parts;

[0014] The modified polyborosiloxane is formed by the reaction of polysiloxane with hydroxyl-terminated, boric acid, dianhydride compounds, and dibromoether compounds.

[0015] As a further improvement of the present invention,

[0016] The preparation method of the modified polyborosiloxane is as follows:

[0017] Step 1:

[0018] Heat the polysiloxane with hydroxyl end groups to 140 °C, then add boric acid and heat to 180 °C, and keep stirring for 0.5 h;

[0019] Step 2:

[0020] Cool down to 90 °C, add triethylamine and dianhydride compounds, and keep stirring and reacting for 5 h;

[0021] Step 3:

[0022] Heat up to 150 °C and react for 5 h while stirring;

[0023] Step 4:

[0024] Cool down to 45 °C, then add dibromoether compounds and a catalyst and react for 6 h to obtain the modified polyborosiloxane.

[0025] As a further improvement of the present invention,

[0026] The siloxane with hydroxyl end groups is dimethylpolysiloxane terminated with dihydroxy groups.

[0027] As a further improvement of the present invention,

[0028] The dianhydride compound is succinic anhydride.

[0029] As a further improvement of the present invention,

[0030] The dibromoether compound is dibromo diethyl ether.

[0031] As a further improvement of the present invention,

[0032] The catalyst is 1,1,3,3 - tetramethylguanidine.

[0033] As a further improvement of the present invention,

[0034] The boric acid is phenylboric acid.

[0035] As a further improvement of the present invention,

[0036] The mass ratio of the polysiloxane with hydroxyl groups, boric acid, triethylamine, dianhydride compounds, dibromoether compounds, and catalyst is 200 - 500:50 - 120:0.1 - 2:30 - 50:100 - 130:0.1 - 2.

[0037] As a further improvement of the present invention,

[0038] The filler is calcium carbonate;

[0039] The foaming agent is AC foaming agent;

[0040] The heat stabilizer is stearic acid;

[0041] The zinc-containing compound is zinc stearate and zinc oxide;

[0042] The crosslinking agent is DCP.

[0043] As a further improvement of the present invention,

[0044] The preparation method is as follows:

[0045] Step A:

[0046] Preheat the internal mixer to 80°C, set the rotation speed to 40 r / min, put EVA, modified polyborosiloxane, filler, heat stabilizer, and zinc-containing compound into the internal mixer for internal mixing and blending. When the temperature of the internal mixer rises to 120°C, add the foaming agent and crosslinking agent, continue to heat and stir until the temperature of the internal mixer rises to 125°C and then discharge;

[0047] Step B:

[0048] Keep the temperature of the two-roll open mill at 90°C, the rotation speed at 30 min / min, and the roll gap at 2 mm. Add the rubber compound obtained in Step A to the two-roll open mill, make 5-10 triangular bales, then take out the sheet. After cooling to room temperature, add it to the crusher to crush and obtain the sole material.

[0049] Traditional polyborosiloxanes are prepared by reacting polysiloxanes with hydroxyl end groups and boric acid. The modified polyborosiloxanes of the present application are prepared by reacting polysiloxanes with hydroxyl end groups, boric acid, dianhydride compounds, and dibromoether compounds. First, the polysiloxane with hydroxyl end groups and boric acid are polymerized. Due to the short polymerization time, the degree of polymerization is incomplete, and there are still hydroxyl groups on the molecular chain. At this time, dianhydride compounds are added for polymerization, and triethylamine is used as a catalyst. Especially when using succinic anhydride for ring-opening, the hydroxyl groups on the main molecular chain can react with the anhydride, so that the other end of the molecular chain is a carboxyl group. At this time, dibromo diethyl ether is added, and 1,1,3,3-tetramethylguanidine is used as a catalyst. The bromine group can react with the carboxyl group, and dibromo diethyl ether has two bromines, so it can play a bridging role, making the molecular chain of polyborosiloxane have ether bonds. By increasing the ether bonds, the compatibility of polyborosiloxane with EVA can be greatly improved, and the mechanical properties are also improved to a certain extent. Especially when phenylboric acid is selected as boric acid, due to the good mechanical properties of phenylboric acid, phenylboric acid is often used to polymerize polyborosiloxane. However, the structure of phenyl is often not compatible with EVA, resulting in poor performance of the final product. The modified polyborosiloxane prepared by the present invention just makes up for this point. Without using a compatibilizer, the performance is similar to or even better than that of using a compatibilizer.

[0050] In the solution of the present invention, during the blending process of the modified polyborosiloxane and EVA, the melt index is better, the fluidity is better, and the compatibility is better. And the mechanical properties are also improved. Detailed implementation mode

[0051] Example 1: Preparation of modified polyborosiloxane

[0052] Step 1:

[0053] Take the dihydroxy-terminated polydimethylsiloxane (hydroxyl content is 9.2%) and heat it to 140 °C. Then add phenylboric acid and heat it to 180 °C, and keep stirring for 0.5 h;

[0054] Step 2:

[0055] Cool down to 90 °C, add triethylamine and succinic anhydride, and keep stirring and reacting for 5 h;

[0056] Step 3:

[0057] Heat up to 150 °C and react for 5 h while stirring;

[0058] Step 4:

[0059] Cool down to 45 °C and immediately add dibromo diethyl ether and 1,1,3,3-tetramethylguanidine and react for 6 h to obtain the modified polyborosiloxane.

[0060] The mass ratio of each raw material is as follows:

[0061] Hydroxyl-terminated polydimethylsiloxane (hydroxyl content is 9.2%): 200 parts

[0062] Phenylboric acid: 100 parts;

[0063] Triethylamine: 0.5 part;

[0064] Succinic anhydride: 40 parts;

[0065] Dibromodiethyl ether: 90 parts;

[0066] 1,1,3,3-Tetramethylguanidine: 0.5 part.

[0067] Example 2: Preparation of the sole material for casual shoes

[0068] Weigh the materials according to the following parts by weight:

[0069] EVA (7470M): 60 parts

[0070] The modified polyborosiloxane prepared in Example 1: 10 parts

[0071] Calcium carbonate: 5 parts;

[0072] Stearic acid: 1 part;

[0073] Zinc stearate: 1 part;

[0074] Zinc oxide: 2 parts;

[0075] AC blowing agent: 3 parts;

[0076] DCP crosslinking agent: 1 part;

[0077] The preparation method is as follows:

[0078] Step A:

[0079] Preheat the internal mixer to 80 °C, set the rotation speed to 40 r / min, and put EVA, modified polyborosiloxane, calcium carbonate, stearic acid, zinc stearate, and zinc oxide into the internal mixer for internal mixing and blending. When the temperature of the internal mixer rises to 120 °C, add the AC blowing agent and DCP crosslinking agent, and continue to heat and stir until the temperature of the internal mixer rises to 125 °C and then discharge;

[0080] Step B:

[0081] Keep the temperature of the two-roll open mill at 90 °C, the rotation speed at 30 min / min, and the roll gap at 2 mm. Add the rubber compound obtained in Step A into the two-roll open mill, make 5 - 10 triangle wraps, then take out the sheet. After cooling to room temperature, add it to the crusher to crush and obtain the sole material.

[0082] Comparative Example 1: Preparation of Polyborosiloxane

[0083] The hydroxyl-terminated polydimethylsiloxane (hydroxyl content 9.2%) was heated to 140 °C, then phenylboronic acid was added and the temperature was raised to 180 °C, and stirring was maintained. The polyborosiloxane was obtained after reacting for 2 h

[0084] The mass ratio of each raw material was as follows:

[0085] Hydroxyl-terminated polydimethylsiloxane (hydroxyl content 9.2%): 200 parts

[0086] Phenylboronic acid: 100 parts.

[0087] Comparative Example 2:

[0088] EVA (7470M): 60 parts

[0089] Modified polyborosiloxane prepared in Comparative Example 1: 10 parts

[0090] Calcium carbonate: 5 parts;

[0091] Stearic acid: 1 part;

[0092] Zinc stearate: 1 part;

[0093] Zinc oxide: 2 parts;

[0094] AC blowing agent: 3 parts;

[0095] DCP crosslinking agent: 1 part;

[0096] The preparation method was as follows:

[0097] Step A:

[0098] The internal mixer was preheated to 80 °C, the rotation speed was set to 40 r / min, and EVA, polyborosiloxane, calcium carbonate, stearic acid, zinc stearate, and zinc oxide were put into the internal mixer for internal mixing and blending. When the temperature of the internal mixer rose to 120 °C, the AC blowing agent and DCP crosslinking agent were added, and the temperature was raised and stirred continuously until the temperature of the internal mixer rose to 125 °C and then discharged;

[0099] Step B:

[0100] The temperature of the two-roll open mill was maintained at 90 °C, the rotation speed was 30 min / min, and the roll gap was 2 mm. The rubber compound obtained in Step A was added to the two-roll open mill and rolled in a triangular shape 5 - 10 times and then sheeted. After cooling to room temperature, it was added to a crusher and crushed to obtain the sole material.

[0101] Comparative Example 3:

[0102] EVA (7470M): 60 parts

[0103] Modified polyborosiloxane prepared in Comparative Example 1: 10 parts

[0104] Silane coupling agent Si-75 (compatibilizer): 0.8 part

[0105] Calcium carbonate: 5 parts;

[0106] Stearic acid: 1 part;

[0107] Zinc stearate: 1 part;

[0108] Zinc oxide: 2 parts;

[0109] AC blowing agent: 3 parts;

[0110] DCP crosslinking agent: 1 part;

[0111] The preparation method is as follows:

[0112] Step A:

[0113] Preheat the internal mixer to 80 °C, set the rotation speed to 40 r / min, and put EVA, polyborosiloxane, calcium carbonate, stearic acid, zinc stearate, and zinc oxide into the internal mixer for internal mixing and blending. When the temperature of the internal mixer rises to 120 °C, add the AC blowing agent and DCP crosslinking agent, continue to heat and stir until the temperature of the internal mixer rises to 125 °C and discharge;

[0114] Step B:

[0115] Keep the temperature of the two-roll open mill at 90 °C, the rotation speed at 30 min / min, and the roll gap at 2 mm. Add the rubber compound obtained in Step A to the two-roll open mill, make triangular bales 5 - 10 times and then take out the sheet. After cooling to room temperature, add it to the crusher to crush and obtain the sole material.

[0116] Raw material list:

[0117]

[0118] Test:

[0119] 1. Melt index test: Refer to GB / T 3682-2000;

[0120] 2. Impact performance test: Refer to ASTM F1614-99, and use three states of a weight (only the weight of the rod), a half-weight (2.5 joules), and a full-weight (5 joules) to simulate the three exercise states of a runner walking, jogging, and running, respectively. The sampling frequency during impact is 6000 Hz.

[0121] (1)Maximum acceleration (G), which represents the peak acceleration during the impact of the hammer head on the foamed material. It is calculated based on the peak impact force (Fmax) measured by the instrument divided by the mass of the drop hammer (m). The magnitude of its value represents the shock absorption ability of the midsole material of the shoe. The smaller the value, the better the cushioning and shock absorption performance of the midsole material.

[0122] (2)Total impact time (DT), which represents the total time of impact and rebound during the process of the hammer head impacting the foamed material. The magnitude of its value can well reflect the instantaneous rebound characteristics of the midsole material during movement. The smaller the value, the shorter the time for the midsole material to return to the initial state after being stressed.

[0123] (3)Energy feedback (ER), which represents the percentage of the impact energy reused during the rebound in the impact process.

[0124] Prepare the materials obtained in Example 2, Comparative Example 2, and Comparative Example 3 into test samples for testing. The specific preparation method is as follows:

[0125] Molding and foaming: Keep the upper and lower molds of the flat vulcanizing machine at a temperature of 185°C. Weigh 220 g of the masterbatch and put it into the mold. Close the mold, and the pressure holding pressure is 10 MPa for 11 min. Obtain the semi-finished foamed test piece. After the test piece is cooled, peel off the upper and lower epidermis, and cut it into a test piece with a thickness of 18.75 mm according to the compression ratio of 1.5 (1.5x12.5 = 18.75) for secondary molding to obtain a test piece with a thickness of 12.5 mm for testing.

[0126]

[0127] After adding the modified polyborosiloxane prepared in Example 1 in Example 2, without adding a compatibilizer, the melt index is far better than that of Comparative Example 2 adding ordinary polyborosiloxane, and there is little difference in the melt index from Comparative Example 3 adding a compatibilizer and ordinary polyborosiloxane. This shows that the modified polyborosiloxane prepared by the present invention has better compatibility. And in the impact performance test, Example 2 is also better than Comparative Example 2 and 3.

[0128] Traditional polyborosiloxanes are prepared by the reaction of polysiloxanes with hydroxyl end groups and boric acid. The modified polyborosiloxanes of this application are prepared by the reaction of polysiloxanes with hydroxyl end groups, boric acid, dianhydride compounds, and dibromoether compounds. First, the polysiloxane with hydroxyl end groups and boric acid are polymerized. Due to the short polymerization time, the degree of polymerization is incomplete, and there are still hydroxyl groups on the molecular chain. At this time, dianhydride compounds are added for polymerization, and triethylamine is used as a catalyst. Especially when succinic anhydride is used for ring-opening, the hydroxyl groups on the main molecular chain can react with the anhydride, so that the other end of the molecular chain is a carboxyl group. At this time, dibromo diethyl ether is added, and 1,1,3,3-tetramethylguanidine is used as a catalyst. The bromine group can react with the carboxyl group, and dibromo diethyl ether has two bromines, so it can play a bridging role, making the molecular chain of polyborosiloxane have ether bonds. By increasing the ether bonds, the compatibility of polyborosiloxane with EVA can be greatly improved, and the mechanical properties can also be improved to a certain extent. Especially when phenylboric acid is selected as the boric acid, due to the good mechanical properties of phenylboric acid, phenylboric acid is often used to polymerize polyborosiloxane. However, the structure of the phenyl group is often not compatible with EVA, resulting in poor performance of the final product. The modified polyborosiloxane prepared by the present invention exactly makes up for this point. Without using a compatibilizer, the performance is similar to or even better than that in the case of using a compatibilizer.

[0129] In the solution of the present invention, during the blending process of the modified polyborosiloxane and EVA, the melt index is better, the fluidity is better, and the compatibility is better. And the mechanical properties are also improved.

[0130] As a specific implementation of the improvement,

[0131] In summary,

[0132] The above is only the preferred implementation mode of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions within the idea of the present invention belong to the protection scope of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A sole material for casual shoes, characterized in that: It is prepared from the following parts by weight: EVA: 30 - 80 parts Modified polyborosiloxane: 2 - 15 parts Filler: 5 - 20 parts Heat stabilizer: 0.5 - 5 parts Zinc-containing compound: 0.2 - 5 parts Blowing agent: 0.5 - 10 parts Crosslinking agent: 0.5 - 5 parts; The modified polyborosiloxane is formed by the reaction of polysiloxane with hydroxyl end groups, boric acid, dianhydride compounds, and dibromoether compounds; The preparation method of the modified polyborosiloxane is as follows: Step 1: Heat the polysiloxane with hydroxyl end groups to 140 °C, then add boric acid and heat to 180 °C, and keep stirring for 0.5 h; Step 2: Cool down to 90 °C, add triethylamine and dianhydride compounds, and keep stirring and reacting for 5 h; Step 3: Heat up to 150 °C, and react with stirring for 5 h; Step 4: Cool down to 45 °C, then add dibromoether compounds and a catalyst and react for 6 h to obtain the modified polyborosiloxane; The polysiloxane with hydroxyl end groups is bis-hydroxy-terminated polydimethylsiloxane; The dianhydride compound is succinic anhydride; The dibromoether compound is dibromo diethyl ether; The catalyst is 1,1,3,3-tetramethylguanidine; The boric acid is phenylboric acid.

2. The sole material for casual shoes according to claim 1, characterized in that: The mass ratio of the polysiloxane with hydroxyl groups, boric acid, triethylamine, dianhydride compounds, dibromoether compounds, and the catalyst is 200 - 500:50 - 120:0.1 - 2:30 - 50:80 - 130:0.1 - 2.

3. The sole material for casual shoes according to claim 1, characterized in that: The filler is calcium carbonate; The blowing agent is AC blowing agent; The heat stabilizer is stearic acid; The zinc-containing compound is zinc stearate and zinc oxide; The crosslinking agent is DCP.

4. The preparation method of the sole material for casual shoes according to any one of claims 1 - 3, characterized in that: The preparation method is: Step A: Preheat the internal mixer to 80 °C, set the rotation speed to 40 r / min, put EVA, modified polyborosiloxane, filler, heat stabilizer, and zinc-containing compound into the internal mixer for internal mixing and blending. When the internal mixer temperature rises to 120 °C, add the blowing agent and crosslinking agent, continue to heat and stir until the internal mixer temperature rises to 125 °C and discharge; Step B: Keep the temperature of the two-roll mill at 90 °C, the rotation speed at 30 min / min, and the roll gap at 2 mm. Add the rubber compound obtained in Step A into the two-roll mill, make triangular bales 5 - 10 times and then take out the sheet. After cooling to room temperature, add it to the crusher to crush to obtain the sole material.

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