CN101543325A - Anti-crocking rubber sole - Google Patents

Abstract

The invention discloses a blowout frost rubber sole, which relates to a rubber sole. Provided are a blowout-proof rubber sole with low production cost, long service life, aging resistance and no blooming and a preparation method thereof. The raw materials include A and B. The raw materials of A are butadiene rubber 72.9, natural rubber 20.2, styrene-butadiene rubber 6.9, precipitated hydrated silica 44.5, bis-(3-triethoxysilanepropyl)-tetrasulfide 0.8, oxidation Zinc 5.3, polyethylene glycol 3.5-4.5, stearic acid 1.0-2.0, rubber tackifier 1.1, active agent 0.8, phenolic antioxidant 0.3-0.6, tackifying resin 0.4, anti-fogging agent 1.0; B raw materials are insoluble Sulfur, tetramethylthiuram monosulfide and accelerator, A: insoluble sulfur: tetramethylthiuram monosulfide: accelerator is 500:1.0～2.5:1.0:0.7. Mixing, refining, vulcanization, vulcanization curve measurement and hydraulic molding, frost spray test.

Description

Anti-blowout rubber sole

technical field

The invention relates to a rubber sole, in particular to a production formula for a spray-out-proof rubber sole.

Background technique

China is currently the world's largest producer and exporter of footwear. However, the problem of frequent frosting on rubber soles has become one of the limiting factors for China's footwear industry at present, and frosting also has a certain seasonality. In summer and autumn, Blooming problems are more likely to occur. Frosting on the rubber surface not only seriously affects the appearance quality of the product, but also affects the service performance and life of the rubber product to a certain extent, and also affects the process performance and physical and mechanical properties of the rubber compound. Frosting will also cause scorching of the rubber material and aging of the product, which will accelerate the aging of the product and shorten the service life. The harm of blooming frost brings huge economic loss to sole manufacturer.

Frosting of rubber soles refers to the phenomenon that sulfur, waxes, accelerators, anti-aging agents, plasticizers, fillers and other compounding agents in rubber products migrate from the inside of the rubber or products to the surface and precipitate substances such as frost . The essential reason is that the amount of these compounding agents exceeds the solubility in the rubber or vulcanized rubber, which is caused by the transition from the metastable state to the stable state.

Rubber blooming is due to the fact that after the compounding agent in the rubber reaches a supersaturated state, the compounding agent near the surface of the rubber is first precipitated, and then migrates and precipitates from the inner layer to the surface layer. When the compounding agent is reduced to its saturated state in the rubber, the precipitation process ends. Finish. The main reasons for the compounding agent to reach supersaturation and rubber blooming are: improper design of rubber formula, improper process operation, fluctuation of raw material quality, rubber aging, etc. The following is a simple analysis of the above problems.

(1) Improper formula design

Improper formula design mainly means that the amount of compounding agent in rubber exceeds its maximum usage amount. Under certain conditions (mainly temperature, followed by pressure), the general compounding agent has a certain solubility in rubber, and the compounding amount that reaches the solubility of the compounding agent is called the maximum usage amount of the compounding agent. When the formula is designed, if the amount of the compounding agent exceeds its maximum amount, the compounding agent cannot be completely dissolved in the rubber, making the compounding agent reach a supersaturated state in the rubber. Since the compounding agent in the rubber will eventually reach a saturated state, in the process of reaching the saturated state, the excessively used and insoluble compounding agent will be precipitated, and blooming will be formed on the surface of the rubber. Usually, the compounding agents that are easy to cause blooming due to improper formula design include vulcanizing agent: sulfur; accelerators: dibenzothiazole disulfide (DM), tetramethylthiuram disulfide (TMTD), 2-mercaptan Benzothiazole (M), tetramethylthiuram monosulfide (TMTM), ethylenethiourea (NA-22), etc.; Antiaging agent: N-phenyl-β-naphthylamine (D), N, N' -diphenyl-p-phenylenediamine and phenyl-β-naphthylamine mixture (H), N-cyclohexyl-N'-phenyl-p-phenylenediamine (4010), N,N'di(β-naphthyl) p-Phenylenediamine (DNP), 2-mercaptobenzimidazole (MB), paraffin, etc.; plasticizer: motor oil, ester oil, etc.; active agent: zinc oxide, stearic acid, etc.; filler: light calcium , magnesium carbonate, etc.; anti-scorch agent: N-cyclohexylthiophthalimide (CTP), etc.

(2) Improper process operation

When the rubber is produced, the weighing of the compounding agent must be accurate first, so as not to cause over-compounding, so that the amount of the compounding agent exceeds its maximum amount in the rubber, and causes blooming. Secondly, it should be fully pressed according to the process operation, so as not to cause uneven tamping and uneven dispersion of compounding agents, so that the local concentration of compounding agents in the rubber material is too high, reaching a supersaturated state, resulting in blooming.

(3) Raw material quality fluctuations

Compounding agents for rubber are mostly industrial products with low purity, and their components are quite different from those commonly referred to as chemicals. The chemical components such as vulcanization accelerators and anti-aging agents are relatively clear anyway, while other compounding ingredients are very crude. For example, stearic acid for rubber is a mixed fatty acid, not pure stearic acid, which is only equivalent to a mixture of palmitic acid (palmitic acid) and oleic acid. Other substances such as zinc oxide, magnesium oxide, and carbon black contain many impurities in their manufacture. Substances such as light calcium and clay vary greatly due to different origin materials, different production methods, different processes, and different batches. Fluctuations in the quality of the compounding agent will cause changes in its purity, moisture, ash, pH value, physical properties, etc. These factors affect its solubility in rubber. If the solubility decreases, the complexing agent will bloom.

(4) Rubber aging

The aging of rubber mostly leads to the destruction of the complete and balanced network structure of the vulcanized rubber, which also destroys the chemical or physical combination between various compounding agents in the rubber system, raw rubber molecules and compounding agents, and reduces the compounding agent in the rubber. Solubility in the system. Therefore, those compounding agents that are partially in a supersaturated state will be separated from the rubber to form blooming. Blooming caused by rubber aging is different from other types of blooming. It is not easy to occur in winter and autumn with low temperature and high humidity, but in summer with high temperature and sun exposure.

The invention patent application with the publication number CN101104711 provides a production formula of anti-aging rubber belt, which is composed of neoprene, natural rubber, sulfur, vulcanizing agent DTDM, zinc oxide, anti-aging agent 4010Na, anti-aging agent ODA, stearic acid, paraffin , High wear-resistant carbon black, accelerator DM, accelerator Na-22 and engine oil. The production method is as follows: firstly, the material is kneaded by a flour mill, and then a certain weight of kneaded rubber is weighed and put into a vulcanizing machine for vulcanization. After the vulcanization is completed, the product is trimmed to be a finished product. The product has the advantages of low production cost, aging resistance, long service life and no frost on the outer surface.

The invention patent whose notification number is CN1281886 provides a preparation method of EPDM waterproof membrane. The method adopts a vulcanization system with sulfur plus low-temperature rapid vulcanization assistant. The additives are: dithiol benzothiazole, dibenzothiazole disulfide, tetramethylthiuram disulfide, zinc methylphenyl dithiocarbamate, ethylene thiourea. In addition to choosing the mixing auxiliary agent blowout prevention frost, the invention also adds the blowout prevention agent asphalt, which improves the reliability of the blowout prevention and facilitates bonding. The asphalt improves the processing performance in the whole system, makes the rubber easier to mix, and is beneficial to improve the physical properties of the waterproof membrane. Adding the mixing additive anti-blooming cream is used in the production of EPDM waterproof membrane, which is beneficial to improve the physical properties of the waterproof membrane.

The invention patent application with the publication number CN1911989 provides a high-elasticity semi-transparent rubber surface for table tennis rackets, including a matrix material composed of a blend of natural rubber and butadiene rubber, a solubilizer, sulfur, a vulcanization activator and a vulcanization accelerator , its formulation quality consists of: 40-80 parts of natural rubber; 20-60 parts of butadiene rubber; 1-5 parts of solubilizer; 1.5-3.5 parts of sulfur; 2-5 parts of vulcanization activator; 1-2.5 parts of vulcanization accelerator .

Although the above-mentioned patent documents have done appropriate research on the anti-blooming of some materials, due to the large differences in the manufacturing process and raw materials of shoe materials from the above, it can only be used as a reference for the production of anti-blooming soles. And so far, also do not see the relevant patent about the anti-blooming aspect of sole material.

Contents of the invention

The object of the present invention is to solve the problem of frosting in the existing rubber soles, and provide a frosting-proof rubber sole with low production cost, long service life, aging resistance and no frosting and a preparation method thereof.

The raw material composition of anti-blooming rubber sole of the present invention comprises A part and B part, and the raw material composition of A part and its formula by mass ratio are: butadiene rubber 72.9, natural rubber 20.2, styrene-butadiene rubber 6.9, precipitation hydration two Silicon oxide (also known as: white carbon black) 44.5, bis-(3-triethoxysilylpropyl)-tetrasulfide 0.8, zinc oxide 5.3, polyethylene glycol 3.5-4.5, stearic acid 1.0-2.0, Rubber tackifier 1.1, active agent 0.8, phenolic antioxidant 0.3-0.6, tackifying resin 0.4, antifogging agent 1.0; the raw materials of part B are composed of insoluble sulfur, tetramethylthiuram monosulfide and accelerator, According to the mass ratio, the total mass of part A: insoluble sulfur: tetramethylthiuram monosulfide: accelerator (MIX-2) is 500: (1.0-2.5): 1.0: 0.7.

The antifogging agent can be refined paraffin wax, microcrystalline wax and hydride mixture, etc.

The polyethylene glycol preferably adopts the PEG-4000 type polyethylene glycol product produced by Guangdong Dongguan Hongbai Chemical Co., Ltd., and the rubber tackifier preferably adopts the RX-80 type rubber thickener produced by Guangdong Dongguan Hongbai Chemical Co., Ltd. For adhesive products, the active agent is best to use the AT-55 active agent product produced by Guangdong Dongguan Hongbai Chemical Co., Ltd., and the accelerator is best to use the MIX-2 accelerator product produced by Guangdong Dongguan Hongbai Chemical Co., Ltd. The best phenolic anti-aging agent is the SPB type phenolic anti-aging agent produced by Guangzhou Jinchangsheng Technology Co., Ltd. The best anti-fogging agent is the 1956 type anti-fogging agent produced by Guangzhou Jinchangsheng Technology Co., Ltd. The best insoluble sulfur is Guangzhou For the IS type insoluble sulfur product produced by Jinchangsheng Technology Co., Ltd., the tackifying resin is best to use the P-90 type tackifying resin product produced by Jinjiang Dongxie Chemical Raw Materials Co., Ltd.

Described butadiene rubber, natural rubber, styrene-butadiene rubber can adopt the product of Taiwan Formosa Plastics Group Corporation, and precipitated hydrated silicon dioxide and two-(3-triethoxysilane propyl)-tetrasulfide can adopt Jinjiang Shi The products of Naibao Technology Co., Ltd., zinc oxide and stearic acid can use the products of Hangzhou Oleochemical Co., Ltd.

The preparation method of anti-spray frost rubber sole of the present invention comprises the following steps:

1) Material weighing

Weigh raw materials according to the designed formula;

2) Banbury

Mix the rubber and tackifier raw materials, start the banbury mixer to mix the materials evenly, add 2/3 of the precipitated hydrated silica, continue banburying, mix the rubber and the precipitated hydrated silica, and re-agglomerate, When the temperature reaches 100°C, add all other raw materials and the remaining precipitated hydrated silica until the temperature continues to rise to 100°C, and the mixture of all raw materials is agglomerated again;

3) open refining

When the kneading is started, the rubber material is discharged as a flake material;

4) Add sulfur

Put the refined flake material in a dry place to stand still, start to use the open mill to add vulcanization, first make the flake material in the open mill for the first and second triangular bags, and then make the third time For triangular bales, there is an accumulation of glue above the roller distance, and sulfur, vulcanization accelerator and color glue are added to the accumulation of glue at the same time, and then the glue is pounded and mixed. After uniformity, the material is discharged;

5) Measurement of vulcanization curve and hydraulic molding

Cut a small piece of material, measure the vulcanization curve with a rheometer, record the scorch time and positive vulcanization time, adjust the vulcanization time of the hydraulic press according to the recorded scorch time and positive vulcanization time, cut the above materials into shoe soles and put them in the hydraulic press for hydraulic molding , get the sole sample;

6) Hydrolysis spray frost experiment

Cut a small piece of the finished shoe sole and put it in the hydrolysis frost spraying machine, observe it after placing it, and record the frost spray phenomenon.

In step 2), the starting temperature of the internal mixer is preferably 20-30°C.

In step 3), it is best to set the roller spacing of 3mm at the beginning, and it is preferably 7.5mm when discharging. Flake discharge is convenient for further processing.

In step 4), the roll spacing of the first and second triangular bagging is preferably 0.5-1mm, and the thickness of the discharged material is preferably 2.5mm.

In step 6), said standing is preferably left for 3 days.

Because the present invention has carried out in-depth analysis on the anti-blooming formula factor of shoe soles, it is concluded that insoluble sulfur is the most important compounding agent, and its dosage plays a key role in the success of vulcanization, and excessive dosage will lead to sulfur spraying. Due to the strong hydrogen bond force of white carbon black, adding polyethylene glycol can effectively improve its dispersibility. If the dosage is large, it is easy to cause blooming due to supersaturation. Since stearic acid is an indispensable active agent in the vulcanization system, there are strict requirements on the amount used. If it is not selected properly, it is easy to oversaturation and cause blooming. Phenolic antioxidants can prevent heat aging, but excessive use can also cause blooming. It can be seen that compared with the existing rubber soles, the rubber soles prepared by the present invention have no blooming, and the product quality reaches the national standard.

Detailed ways

The following examples will further illustrate the present invention

Embodiment 1: the preparation method of anti-blooming rubber sole of the present invention comprises the following steps:

1) Material weighing

Raw material formula is shown in Table 1, wherein, the addition of insoluble sulfur, tetramethylthiuram monosulfide and promotor is according to A part (the raw material composition of A part comprises butadiene rubber, natural rubber, styrene-butadiene rubber, precipitated hydrated two Silicon oxide, bis-(3-triethoxysilylpropyl)-tetrasulfide, zinc oxide, polyethylene glycol, stearic acid, rubber tackifier, active agent, phenolic antioxidant, tackifying resin and Antifogging agent) is calculated as the total mass of 500g.

Table 1

2) Banbury

Mix the rubber and tackifier raw materials, start the banbury mixer to mix the materials evenly, add 2/3 of the precipitated hydrated silica, continue banburying, mix the rubber and the precipitated hydrated silica, and re-agglomerate, When the temperature reaches 100°C, add all other raw materials and the remaining precipitated hydrated silica, until the temperature continues to rise to 100°C, the mixture of all raw materials is agglomerated again, and the start-up temperature of the internal mixer is 20°C.

3) open refining

When the kneading is started, the rubber material is discharged as a flake material. The roller spacing of the kneading is 3mm at the beginning, and it is 7.5mm at the time of the kneading. The main purpose of the kneading is to make the rubber and the compounding agent mix more evenly. The material is discharged in sheet form, which is convenient for further processing.

4) Add sulfur

Put the refined flake material in a dry place to stand still, start to use the open mill to add vulcanization, first make the flake material in the open mill for the first and second triangular bags, and then make the third time For triangular bales, there is an accumulation of glue above the roller distance, and sulfur, vulcanization accelerator and color glue are added to the accumulation of glue at the same time, and then the glue is pounded and mixed. After uniformity, the material is discharged. The roll distance of the first and second triangular bags is 0.5mm, and the thickness of the discharge is 2.5mm.

5) Measurement of vulcanization curve and hydraulic molding

Cut a small piece of material, measure the vulcanization curve with a rheometer, record the scorch time and positive vulcanization time, adjust the vulcanization time of the hydraulic press according to the recorded scorch time and positive vulcanization time, cut the above materials into shoe soles and put them in the hydraulic press for hydraulic molding , get the sole sample;

6) Hydrolysis spray frost experiment

Cut a small piece of the finished shoe sole and put it in the hydrolysis frost spraying machine, observe it after placing it for 3 days, and record the frost spray phenomenon.

Embodiment 2: Similar to Embodiment 1, the difference is that the raw material formula is shown in Table 2, the start-up temperature of the internal mixer is 25° C., and the roll distance of the first and second triangular buns is 1 mm.

Table 2

Embodiment 3: Similar to Embodiment 1, the difference is that the raw material formula is shown in Table 3, and the starting temperature of the internal mixer is 30°C.

table 3

Embodiment 4: Similar to Embodiment 1, the difference is that the raw material formula is shown in Table 4, the starting temperature of the internal mixer is 25° C., and the roll distance of the first and second triangular buns is 1 mm.

Table 4

Embodiment 5: Similar to Embodiment 1, the difference is that the raw material formula is shown in Table 5, and the roll spacing of the first and second triangular buns is 1mm.

table 5

Embodiment 6: Similar to Embodiment 1, the difference is that the raw material formula is shown in Table 6, and the starting temperature of the internal mixer is 25°C.

Table 6

Embodiment 7: Similar to Embodiment 1, the difference is that the raw material formula is shown in Table 7, and the starting temperature of the internal mixer is 25°C.

Table 7

Samples were made according to the above formula, and placed in a high temperature and high humidity environment for hydrolysis and frost spraying experiments. Take it out after 3 days, and record the phenomenon, all normal, no frosting. See Table 8 for the physical property test results of the soles of Examples 1 to 7, which proves that the formula designed according to the above principles can effectively prevent blooming caused by aging under high temperature and high humidity conditions.

Table 8

Comparative example 1 (blooming occurs): the raw material formula is shown in Table 9.

Table 9

Comparative Example 2 (blooming occurs): see Table 10 for the composition of raw materials.

Table 10

Comparative Example 3 (blooming occurs): see Table 11 for the composition of raw materials.

Table 11

Samples were made according to the formulas of Comparative Examples 1 to 3 above, and placed in a high-temperature and high-humidity environment for hydrolysis and frost spraying experiments. Take it out 3 days later, record the phenomenon, and find that the frosting is serious.

Claims (8)

1. anti-bloom rubber soles is characterized in that its raw material is formed and comprises A part and B part, the raw material composition of A part and be butadiene rubber 72.9 by the prescription of mass ratio, natural rubber 20.2, butadiene-styrene rubber 6.9, precipitated hydrated silica 44.5, two-(3-triethoxysilane propyl group)-tetrasulfide 0.8, zinc oxide 5.3, polyethylene glycol 3.5～4.5, stearic acid 1.0～2.0, rubber tackifier 1.1, activating agent 0.8, phenol antiager 0.3～0.6, tackifying resin 0.4, antifoggant 1.0; The raw material of B part consists of: insoluble sulfur, tetramethylthiuram monosulfide and promoter, press mass ratio, A part gross mass: insoluble sulfur: tetramethylthiuram monosulfide: promoter is 500: (1.0～2.5): 1.0: 0.7.

2. a kind of anti-bloom rubber soles as claimed in claim 1 is characterized in that antifoggant is fully refined paraffin wax, microwax and hydride mixture.

3. a kind of according to claim 1 preparation method of anti-bloom rubber soles is characterized in that may further comprise the steps:

1) material weighing

Prescription raw materials weighing by design;

2) banburying

Rubber-like is mixed with tackifier class raw material, start the banbury banburying, make mixing of materials even, add 2/3 precipitated hydrated silica, continue banburying, rubber and precipitated hydrated silica mix, again caking when treating that temperature reaches 100 ℃, adds other all raw materials and remaining precipitated hydrated silica, when temperature continued to be elevated to 100 ℃, the mixture of all raw materials lumpd once more;

3) open refining

Open refining, sizing material is with the sheet material discharging;

4) add sulphur

Be put in dry place and leave standstill opening the sheet material of producing, bring into use mill to add sulphur, earlier sheet material is played the first time and the triangle bag second time in mill, played triangle bag for the third time again, above roll spacing, leave spacer gel, simultaneously sulphur, vulcanization accelerator and coloring agent are added on the spacer gel, then smash glue, mix, open the refining play and be changed to triangle bag and the clot method of beating, after mixing, discharging;

5) survey curing curve and oil pressure moulding

Clip one small pieces material, become instrument with sulphur and survey curing curve, record time of scorch and sulfurizing time are according to the cure time of record time of scorch and sulfurizing time adjusting hydraulic press, above material is cut into the sole shape be put in oil pressure moulding in the hydraulic press, promptly get the sole sample;

6) hydrolysis bloom experiment

The sole of making is cut a fritter put in the hydrolysis bloom machine, observe after the placement, record bloom phenomenon.

4. as the preparation method of a kind of anti-bloom rubber soles as described in the claim 3, it is characterized in that in step 2) in, the turn-on temperature of banbury is 20～30 ℃.

5. as the preparation method of a kind of anti-bloom rubber soles as described in the claim 3, it is characterized in that in step 3) the roller spacing of opening refining has just begun to be 3mm, is 7.5mm during discharging.

6. as the preparation method of a kind of anti-bloom rubber soles as described in the claim 3, it is characterized in that in step 4), describedly beat the first time and the roll spacing of triangle bag for the second time is 0.5～1mm.

7. as the preparation method of a kind of anti-bloom rubber soles as described in the claim 3, it is characterized in that in step 4) the thickness of discharging is 2.5mm.

8. as the preparation method of a kind of anti-bloom rubber soles as described in the claim 3, it is characterized in that in step 6) that described placement is to place 3 days.