A NBE-modified SBC shoe outsole material and a method for preparing the shoe outsole

Abstract

The present invention discloses an NBE-modified SBC shoe outsole material and a method for preparing the same. The NBE-modified SBC shoe outsole material comprises a butadiene-acrylonitrile rubber exhibiting thermoplastic elastic behavior, a polystyrene-conjugated diene thermoplastic elastomer with a high side branch content, and auxiliary materials. The shoe outsole prepared by extrusion granulation, molding, or extrusion molding of the NBE-modified SBC shoe outsole material not only has a high anti-slip coefficient but also exhibits exceptional bonding strength to the upper fabric without requiring special surface treatment.

Description

Technical Field

[0001] The invention relates to a shoe outsole material, in particular to an NBE-modified SBC shoe outsole material and a method for preparing a shoe outsole using the NBE-modified SBC shoe outsole material, belonging to the technical field of shoe outsole material synthesis. Background Art

[0002] Existing commercially available nitrile rubbers (such as NBR3365, NBR1052, and NBR3355 produced by Nandi Chemical) typically contain 25-42% acrylonitrile by mass and have a Mooney viscosity of 30-90. These rubbers are formed by copolymerizing acrylonitrile and butadiene in an emulsion at low temperatures. The acrylonitrile and butadiene bound in the NBR molecular structure are randomly distributed, resulting in low raw strength and lacking the behavior of thermoplastic elastomers. Therefore, these rubbers are unsuitable for shoe soles. Only vulcanized versions are of practical value. For example, Chinese patents CN103665265A, CN103450397A, and CN104628955A all describe the preparation of nitrile rubber or modified ternary copolymer rubber by copolymerizing acrylonitrile and butadiene (or / and a third monomer) under emulsion conditions. Chinese patent (CN110066481A) provides an application of nitrile rubber, which contains 10-20 parts of nitrile rubber; 12-20 parts of chlorinated paraffin; 10-20 parts of naphthenic oil; 6-12 parts of carbon black N550; 30-40 parts of polyvinyl chloride; 10-20 parts of calcium carbonate; 3-10 parts of a foaming agent; 0.5-0.8 parts of a cross-linking agent DCP; 0.5-1 parts of a foaming and cross-linking auxiliary agent; and 0.2-0.5 parts of stearic acid. That is, the description is about the vulcanization of nitrile rubber for oil-resistant rubber products, but there is no report in the literature on the use of polymers containing block or microblock polyacrylonitrile combined with molecular chain NBR and existing commercially available NBR for shoe sole materials or modified styrene-butadiene thermoplastic elastomers.

[0003] Traditional TPR shoe sole materials are typically a polymer material modified by blending a styrene-butadiene thermoplastic elastomer (SBS) with polystyrene, calcium carbonate powder, white oil, colorants, and other functional additives. The material is then processed through mixing, extrusion, injection molding, and compression molding to create the sole. Commonly used SBS is a commercially available copolymer of styrene and butadiene. SBS grades include 875, 675, 1475, 1487, 805, 815, and 4452, both oil-extended and non-oil-extended. These rubbers contain no polar groups and are also known as non-polar rubbers. SBS, the primary raw material in TPR, forms the backbone of the sole material, providing key properties such as strength and elasticity. Currently, TPR shoe sole materials are gaining acceptance among manufacturers, retailers, and consumers. However, their drawbacks include low adhesion between the outsole and the upper fabric, easy debonding, and poor slip resistance. For example, Chinese patent (CN105237822A) describes the formula of a sole material synthesized from natural rubber and SBS and its preparation method. The formula consists of 60-80 parts of natural rubber, 15-25 parts of SBS, 10-20 parts of white carbon black, 10-15 parts of EVA, 10-15 parts of polybutadiene, 0.5-1 part of silicon 69, 0.3-0.5 parts of diethylene glycol, 0.8-1.6 parts of vulcanizing agent, 5-15 parts of softening oil, etc. The composite material needs to use peroxide to crosslink and vulcanize the double bonds in the rubber molecules before it has any use value. This method uses polyvinyl acetate (EVA) to modify SBS and polarize the composite material. Chinese patent (CN107033520A) has introduced a kind of preparation method of wear-resistant SBS sole material, sole material is made up of SBS, calcium carbonate, MALEIC ANHYDRIDE, Polyethylene Glycol, polystyrene and resin and small material, its sole preparation process is carried out in 5 steps, and operation is loaded down with trivial details, and this method adopts MALEIC ANHYDRIDE to carry out grafting SBS, with its polarization, helps polar adhesive that sole and vamp (as leather) material are reached effective bonding. (" development of SBS sole glue ", Zhang Changde etc., Beijing chemical industry, nineteen ninety-four 2 phases) described SBS in one literary composition is non-polar material, with the affinity difference between all kinds of shoemaking fabrics, need its surface be chemically treated when causing existing adhesive to be used for bonding SBS sole, shortcoming such as easy peeling off glue, it is solvent that this literary composition adopts cyclohexane, with acrylate monomer, SBS is carried out a kind of adhesive of grafting modification preparation, and the SBS sole material of bonding and leather material just have bonding strength. Similarly, in literature such as ("A Production Method for TPR Shoe Material Surface Treatment Agent", Polyurethane Industry, 2013), ("Application of Domestic Polyurethane Adhesives on Low-Polarity Shoe Materials", Polyurethane Industry, 2002), and ("Development of PR Surface Treatment Agents", China Adhesives, 2004), it is widely reported that existing SBS / TPR sole materials must first use a polar surface treatment agent to treat the bonding surface between the sole and the upper, and then apply a polyurethane adhesive before pressure bonding to the upper fabric.

[0004] In summary, existing SBS / TPR shoe sole materials are all non-polar. Modifying SBS with maleic anhydride or EVA has drawbacks such as a long preparation process, low grafting efficiency, and easy crosslinking and coagulation. Even with a small amount of grafting, the modified SBS remains a low-polarity macromolecule. Therefore, as a shoe sole material, the adhesive surface of the injection-molded sole still requires chemical surface treatment before polyurethane coating can be applied to the upper fabric. Furthermore, the debonding time of existing TPR shoe uppers is much shorter than the wear time of the soles. Furthermore, the polybutadiene vinyl unit content of existing SBS molecules is less than 18%, resulting in poor anti-slip properties for the resulting soles. Therefore, the development of new SBS or TPR shoe sole materials with excellent anti-slip properties, easy bonding, high bond strength, and long-lasting durability is worthy of development. Summary of the Invention

[0005] In response to the defects of SBS or TPR shoe sole materials in the prior art, the present invention aims to provide a shoe outsole material whose main raw materials are nitrile rubber having polarity and thermoplastic elastomer behavior and SBS having a high vinyl unit content. The shoe outsole material can be formed into a shoe outsole with excellent wear resistance and anti-slip properties through blending, molding and vulcanization. The shoe outsole material has micro-crosslinking and high molecular polarity, and has good affinity with polar materials of the upper. This is beneficial for manufacturing shoes with long-lasting adhesion between the outsole and the upper fabric using existing adhesives without surface treatment.

[0006] Another object of the present invention is to provide a method for preparing a shoe outsole by mixing and granulating a styrene-conjugated diene elastomer (SBC) and a thermoplastic butadiene-acrylonitrile elastomer (NBE) exhibiting thermoplastic elastomer behavior with fillers and other additives, and a method for preparing a shoe outsole by compression molding or injection molding the composite material. The method or process is characterized by simple operation, low cost, and ease of industrial production.

[0007] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0008] In order to achieve the above technical objectives, the present invention provides an NBE modified SBC shoe outsole material, which comprises component raw materials including SBC, NBE and auxiliary materials;

[0009] The NBE has the structure of Formula 1:

[0010] A I -Bm1 A nn -B m2 A nn-1 …B mm-1 A n2 -B mm A n1 -B mm-1 A n2 ...B m2 A nn-1 -B m1 A nn -A II

[0011] Formula 1

[0012] in,

[0013] A represents a polyacrylonitrile block, and B represents a polybutadiene block;

[0014] I, II, n1, n2...nn-1, nn represent the degree of polymerization of A, I or II is much larger than n1, n2...nn-1 or nn, and n1 to nn increase successively, 3≥n1≥0, nn>3; m1, m2...mm-1, mm represent the degree of polymerization of B, and m1 to mm increase successively, 0≤m1<3, mm≥3; I>II>3.

[0015] As a preferred solution, the mass ratio of the butadiene block to the acrylonitrile block in the NBE is (55-40) / (45-60).

[0016] As a preferred solution, the NBE has a melt index of (0.1-8) g / 10 min at 200° C., a 300% modulus of stress >1.0 MPa, a tensile strength >10.0 MPa, an elongation at break of 700%, a permanent deformation <30%, a Shore A hardness of 55-60, and a glass transition temperature <-15° C.

[0017] As a preferred embodiment, the SBC is a styrene-conjugated diene copolymer. The SBC is further preferably a triblock derivative copolymer of polystyrene-butadiene and / or isoprene, such as styrene-based elastomers known to those skilled in the art, such as SBS, SIS, and SIBS. Preferred SBCs have a vinyl unit mass fraction of 58-65% in the polybutadiene segment, such as SBS-179 (60% vinyl unit mass fraction in the diene segment) and SIS-1209 (70% bound isoprene mass fraction) produced by the Synthetic Rubber Division of Sinopec Baling Petrochemical Company, as well as polystyrene-butadiene and isoprene-polystyrene (SIBS) products with at least 50% side branches in the soft segment, such as SIBS-935 and SIBS1203.

[0018] As a preferred embodiment, the styrene-conjugated diene copolymer contains no less than 30% by mass of styrene units, and no less than 50% by mass of side-branched units in the conjugated diene units. In the prior art, when the side-branched units in the conjugated diene units of polystyrene-conjugated diene rubbers, such as solution-polymerized styrene-butadiene rubber (SSBR), are greater than 57% by mass, their vulcanizates exhibit excellent wet skid resistance (or anti-skid performance), a prerequisite for the production of high-performance tires. Selecting a styrene-based elastomer with a high mass fraction of side-branched units in the conjugated diene polymer units is essential for the anti-skid properties of the shoe outsole prepared by the present invention.

[0019] As a preferred solution, the auxiliary materials include PS, inorganic filler, softening oil, coupling agent, whitening agent or pigment, cross-linking agent and paraffin.

[0020] As a preferred solution, the inorganic filler is at least one of white carbon black, carbon black and calcium carbonate powder. The inorganic filler acts as a reinforcing agent, preferably at least one of white carbon black, carbon black and calcium carbonate powder, such as commercially available specific surface area of ​​280 to 320 m 2 At least one of Rhodia 175MP, Quecheng Silicate H810, carbon black N330, and light or heavy calcium carbonate powder with a mesh size of at least 1000 is used. The coarse and fine ratio of the filler is beneficial for enhancing the strength of the composite shoe sole material and reducing costs. The preferred filler is calcium carbonate / white carbon black (and / or) carbon black (by weight) = (2-4) / 1.

[0021] As a preferred solution, the softening oil is white oil and / or naphthenic oil. The softening oil is preferably white oil or naphthenic oil, such as commercially available industrial white oils such as 680#, 460#, N4010, N4006 and 100#.

[0022] As a preferred solution, the coupling agent is at least one of KH-550, Silicon-69, or Silicon-75. The preferred coupling agent can effectively couple and compatibly couple the polar reinforcing filler with the rubber, while increasing the rubber's "powder absorption" rate for the powder.

[0023] As a preferred solution, the whitening agent is fluorescent whitening agent OB, and the pigment is at least one of carbon black, ultramarine, iron oxide red and disperse blue.

[0024] As a preferred solution, the cross-linking agent is at least one of dicumyl peroxide, 1,1-di-tert-butylcyclohexane peroxide and p-menthane peroxide.

[0025] As a preferred solution, an NBE-modified SBC shoe outsole material includes the following raw materials by weight: 100 parts of SBC; 20-30 parts of NBE; 10-30 parts of PS; 60-80 parts of filler; 30-80 parts of softening oil; 5-8 parts of coupling agent; 0.5-1.5 parts of brightener or pigment; 1-3 parts of paraffin wax; and 0.5-2.0 parts of crosslinking agent.

[0026] The present invention also provides a method for preparing a shoe outsole from an NBE-modified SBC shoe outsole material, which comprises the following steps:

[0027] 1) SBC, NBE, PS, filler, softening oil, coupling agent, paraffin wax and brightener or pigment are uniformly mixed in a mixer at high speed to obtain a mixture;

[0028] 2) Melting and extruding the mixture through a screw extruder, and pelletizing to obtain pellets;

[0029] 3) After the pellets are fully mixed with the cross-linking agent, they are melted and hot-pressed and cross-linked by an injection molding machine or a molding machine, and then cooled and demolded to obtain the shoe outsole.

[0030] As a preferred solution, the melt extrusion temperature is 150-190°C.

[0031] As a preferred solution, the melting temperature in the melt hot pressing cross-linking molding process is 180-190° C., and the hot pressing molding or cross-linking molding time is 200-300 seconds.

[0032] The molecular chain segments of NBE involved in the present invention are distributed as follows:

[0033] A I -B m1 A nn -B m2 A nn-1 …B mm-1 A n2 -B mm A n1 -B mm-1 A n2 ...B m2 A nn-1 -B m1 A nn -A II

[0034] Formula 1

[0035] Wherein, "A" represents polyacrylonitrile block, "B" represents polybutadiene block, I, II, n1, n2...nn-1, nn represent the degree of polymerization of A, m1, m2...mm-1, mm represent the degree of polymerization of B, and the degree of polymerization is a positive integer ≥ 0; and I and II are much larger than n1, n2...nn-1 and nn, A I and A II Indicates the relatively large molecular weight homopolymer polyacrylonitrile blocks at both ends of the nitrile copolymer (such as A I The number average molecular mass Mn>10000), B m1 A nn -B m2 A nn-1 …B mm-1 A n2 -B mm A n1 -B mm-1 A n2 ...B m2 A nn-1 -B m1 A nn It represents the random copolymerization block of acrylonitrile and butadiene, and 0≤m1<3, mm≥3, 3≥n1≥0, nn>3; the random copolymerization block contains many small polyacrylonitrile blocks and polybutadiene blocks, and the lengths of these small blocks show a gradual change. For example, the length of the small polybutadiene block is determined by B m1 To B mm Gradually becomes longer, Bmm is the butadiene homopolymer block with relatively large polymerization degree, and the length of the small polyacrylonitrile block is from A to n1 To A nn Gradually becomes longer, An1 is a polyacrylonitrile block with a relatively low degree of polymerization. One end or both ends of this nitrile copolymer are polyacrylonitrile blocks with a higher degree of polymerization, which are equivalent to hard segments, and the random copolymer block of acrylonitrile and butadiene is equivalent to a soft segment because a polybutadiene block is mixed in the middle. Therefore, the entire nitrile copolymer exhibits thermoplastic elastomer behavior.

[0036] The NBE provided by the present invention is prepared by three-stage polymerization:

[0037] The adopted emulsion polymerization system consists of deionized water, an emulsifier, a dispersant, an electrolyte, a molecular weight regulator, a deoxidizer, an oxidizer, a reducing agent and an activator; the emulsifier is potassium hydrogenated rosin and potassium oleate; the dispersant is sodium methylene dinaphthalene sulfonate; the electrolyte is at least one of sodium phosphate, potassium chloride and sodium carbonate; the molecular weight regulator is tert-dodecyl mercaptan; the deoxidizer is sodium dithionite; the oxidizer is at least one of highly active peroxide of menthane and pinane hydroperoxide; the reducing agent is bleaching powder; and the activator is EDTA-sodium iron.

[0038] The polymerization reaction conditions are: temperature of 20-30°C, polymerization pressure of 0.3-0.5 MPa, and polymerization raw materials are added in three stages:

[0039] One-stage polymerization: Add 30-50% of the total set amount of acrylonitrile monomer (A) and carry out homopolymerization for 3.5-4 hours; in this process, only part of the acrylonitrile undergoes homopolymerization, and the conversion of A is preferably controlled at ≥70%, and the number average molecular weight Mn of the polyacrylonitrile block is >12000;

[0040] Second stage polymerization: Add a set amount of butadiene (B) and conduct a polymerization reaction for at least 3 hours. This process includes molecular chain growth between B and the polyacrylonitrile (PA) segments formed in the first stage polymerization, as well as copolymerization of unreacted A with B. The B conversion rate is preferably controlled to be >80%. Residual A in the polymerization environment combines with B, and A is distributed in the copolymer molecules in a decreasing gradient, forming soft segments.

[0041] Three-stage polymerization: The remaining 50-70% of the total set amount of A is added to the polymerization environment for copolymerization. The polymerization reaction time is not less than 3.5 hours, and the total monomer conversion rate is not less than 97%. This process includes the chain growth reaction of A with the chain segments generated in the second stage, as well as the copolymerization reaction of B with A that has not reacted completely in the second stage. During this process, the residual amount of B is relatively small. As the monomer concentration in the polymerization environment and the difference in the reactivity rate of A and B change dynamically, the B incorporated in the copolymerization chain growth is distributed in the polymer molecules in a descending order.

[0042] After the polymerization reaction is completed, the polymer latex is discharged, and a certain amount of antioxidant is added and stirred evenly. The latex is slowly added in batches to a solution composed of dicyandiamide formaldehyde condensate, concentrated sulfuric acid and water at 50-60°C for coagulation, and stirring is added. The remaining unreacted small amount of monomer acrylonitrile is dissolved in the aqueous phase. After 10 minutes, milky white granular micelles can be obtained.

[0043] The PS involved in the present invention is a rigid polystyrene resin commonly known in the professional and technical industry for preparing TPR using SBS. Polystyrene foam recycled pellets or polystyrene (PS) prepared by bulk or suspension methods can be selected, such as commercially available products such as PH-888G.

[0044] The paraffin wax involved in the present invention is used as a release agent.

[0045] It is worth mentioning that the polymers used in the shoe outsole material formulation of the present invention are all thermoplastic elastomers. Therefore, even without the use of a crosslinking agent, the NBE, PS, and SBC polymer macromolecules in the shoe outsole after injection molding from the pre-made extruded composite pellets (TPR) exhibit an island-in-sea structure, and the shoe outsole is still usable or applicable. However, the appropriate addition of a small amount of crosslinking agent to the composite pellets can effectively micro-crosslink the double bonds in the NBE and SBC molecules, further improving the compatibility of the NBE and SBC, while further increasing the density of the crosslinked network of the injection-molded or compression-molded body, thereby enhancing its strength.

[0046] The method for preparing a shoe outsole using an NBE-modified SBC shoe outsole material provided by the present invention is carried out by the following steps:

[0047] Step 1: Place SBC, NBE, PS, filler, softening oil, coupling agent, brightener or pigment and paraffin into a mixer at room temperature and stir at high speed to mix them evenly.

[0048] The second step: the mixed material is put into a screw extruder and melt-extruded at 150-190°C to obtain pellets, which are the well-known TPR colored or colorless pellets.

[0049] Step 3: After the pellets and the cross-linking agent are fully mixed, the mixture is melt-hot-pressed and cross-linked at 180-190°C on an injection molding machine or a molding machine. The heat setting time (or cross-linking time) is 200-300 seconds (s). After cooling and demolding, the designed shoe outsole can be obtained.

[0050] The preferred connecting agent for bonding the outsole prepared by the present invention to the upper fabric is a polyurethane adhesive, such as commercially available Nanguang resin glue.

[0051] The composite granules and shoe outsoles prepared by the present invention have a breaking strength of >6MPa, a breaking elongation of >200%, a tear strength of >54N / mm, and a wear of <135mm. 3 , dry anti-slip coefficient>1.2, peel strength (glue and cowhide)>65N / mm.

[0052] Compared with the existing technology, the technical solution of the present invention has the following beneficial effects:

[0053] Compared with the defects of the existing TPR composed of SBS and fillers, the present invention uses styrene-conjugated diene block thermoplastic elastomer (SBC) with high side branching chains as the main rubber, which is beneficial to the vulcanized or sheeted rubber and the products with higher anti-slip performance; at the same time, a new type of nitrile rubber with the behavior of thermoplastic elastomer is selected.

[0054] NBE is used as an auxiliary adhesive source in a blend with SBC to improve the molecular polarity of the low-polarity polymer SBC and enhance the long-lasting and high adhesion of the sole and upper fabrics made from the blended adhesive to the outsole made with existing adhesives without surface cleaning and polishing. A small amount of cross-linking agent is used to micro-cross-link the double bonds in the NBE and SBC molecules, improving their compatibility and the tensile strength of the sole.

[0055] That is, the shoe outsole of the present invention has good anti-slip performance and high strength, high bonding strength between the shoe outsole and the upper fabric, and is tear-resistant. The composite granulation process of NBE and SBC, fillers and additives is easy to control, the process is short, the operation is simple, convenient and low-cost. In addition, the process from granulation to shoe outsole production is simple, the molding time is short, and industrialization is easy, and the process can be completed using existing mature processes. DETAILED DESCRIPTION

[0056] The present invention is illustrated by the following examples, which are not intended to limit the scope of the invention or its implementation.

[0057] In the following examples, the number average molecular weight of the polymer was determined by gel permeation chromatography (GPC); the glass transition temperature (Tg) of the polymer was determined by differential thermal analysis (DSC); and the H 1 -NMR spectroscopy was used to determine the microstructure of the polymer; the physical properties of the vulcanized rubber were determined using an INSTRON tensile testing machine; the adhesive strength (N / mm) was determined using the DW-22GT-TCS2000 (100±mm / min) method; the DIN abrasion (mm3) was determined using the DW-15GT-7012-D rotary (40±1) r / min (10±0.2) N method; and the anti-slip coefficient was determined using the DW-09BL-312 dry and wet methods.

[0058] Example 1

[0059] In a 5-liter polymerizer, 1.8 liters of deionized water were added, and then 70 mL of 15.0 wt % potassium oleate solution, 50 mL of 25.0 wt % disproportionated rosin potassium solution, 17 mL of 2.0 wt % EDTA sodium iron salt solution, and 15 mL of 10.0 wt % sodium methylene dinaphthalenesulfonate aqueous solution were added respectively. 20 mL of 10.0 wt % potassium chloride aqueous solution were added respectively, 5 mL of 5 wt % sodium dithionite aqueous solution, 16 mL of 6.5 wt % bleaching powder aqueous solution, 1.3 g of p-menthane peroxide, and 3.8 g of tert-dodecyl mercaptan. The auxiliary agents were pressed into the polymerizer with nitrogen, and stirring was started, and the reaction solution was controlled to 10-20 ℃. At this time, 230 g of acrylonitrile was pressurized into the polymerization kettle with nitrogen and reacted for 4 hours. A sample of the polymer emulsion was taken and the polymer was precipitated with anhydrous ethanol. The conversion of the polymerized monomer after filtration and drying was 78.2%, and the number average molecular weight of the polymer was Mn1=11200. At this time, 805 mL (500 g) of butadiene was added to the polymerization kettle, and the polymerization was carried out for 4 hours while maintaining the pressure in the kettle at 0.3-0.5 MPa. When the monomer conversion was 82.3%, the remaining 270 g of acrylonitrile in the third stage design amount was added to the kettle and copolymerization was carried out for 3.5 hours. At this time, the monomer conversion was measured to be 98.4%. After the polymerization reaction showed no temperature increase, the reaction was visually terminated.

[0060] Unload and add 3.5g of antioxidant 1076 to the latex liquid. After mixing evenly, the latex is slowly added in batches to a solution consisting of 40g of dicyandiamide formaldehyde condensate, 15g of concentrated sulfuric acid and 30 liters of water at 50-60°C for coagulation, and stirring is added. The remaining unreacted small amount of monomer acrylonitrile is dissolved in the aqueous phase. After 10 minutes, milky white granular micelles can be obtained.

[0061] The results showed that the mass fraction of vinyl units in the prepared NBE (labeled as NBE-1) molecule was 11.5%, the mass fraction of combined acrylonitrile was 49.6%, the melt index (MFR) was 0.16 g / 10 min, the 300% modulus was 1.2 MPa, the tensile strength at break was 10.3 MPa, the elongation at break was 760%, the permanent deformation was 23%, the hardness (Shao A) was 53, and the glass transition temperature was -18.6°C.

[0062] Example 2

[0063] The relevant conditions in Example 1 were not significantly adjusted, and the amount of additives used was controlled within the specified range of the present invention. Only 280 g of acrylonitrile and 4 g of tert-dodecyl mercaptan were added in the first and third stages.

[0064] The results showed that the number average molecular weight of the first stage polymer Mn1 = 12400, the mass fraction of vinyl units in the NBE molecule after condensation and drying (calibrated as NBE-2) was 11.4%, the mass fraction of combined acrylonitrile was 52.6%, the glass transition temperature was -16.4°C, the MFR was 2.53 g / 10min, the 300% modulus was 1.23 MPa, the tensile strength at break was 11.4 MPa, the elongation at break was 740%, the permanent deformation was 22%, and the hardness (Shao A) was 54.

[0065] Example 3

[0066] The relevant basic conditions in Example 1 remain unchanged, except that 300 g of acrylonitrile is added in the first and third stages, 450 g of butadiene is added in the second stage, and 4.5 g of tert-dodecyl mercaptan is added.

[0067] The results showed that the number average molecular weight of the first-stage polymer Mn1 was 14500, the mass fraction of vinyl units in the NBE molecule after condensation and drying (calibrated as NBE-3) was 11.1%, the mass fraction of combined acrylonitrile was 57.8%, the glass transition temperature was -14.7°C, the MFR was 4.85g / 10min, the 300% modulus was 1.32MPa, the tensile strength at break was 12.6MPa, the elongation at break was 730%, the permanent deformation was 28%, and the hardness (Shao A) was 56.

[0068] Example 4

[0069] The relevant basic conditions in Example 3 remained unchanged, except that 290 g of acrylonitrile was added in the first and third stages, 400 g of butadiene was added in the second stage, and 5.0 g of tert-dodecyl mercaptan was added.

[0070] The results showed that the number average molecular weight of the first-stage polymer Mn1 = 11600, the mass fraction of vinyl units in the dried NBE (calibrated as NBE-4) molecule was 10.7%, the mass fraction of bound acrylonitrile was 59.3%, the glass transition temperature was -13.6°C, the MFR was 7.46 g / 10min, the 300% modulus was 1.35 MPa, the tensile strength at break was 13.5 MPa, the elongation at break was 720%, the permanent deformation was 28%, and the hardness (Shao A) was 58.

[0071] Application Examples

[0072] The NBE-1, NBE-2, NBE-3 and NBE-4 prepared above were respectively mixed with SBC elastomers such as SBS-179, SIS-1209, SIBS-935 and SIBS1203, as well as a control sample of at least one SBS with a low side vinyl content in the molecular chain and corresponding fillers and additives, and screw extruded to prepare the corresponding TPR pellets.

[0073] The specific process of preparing the outsole is carried out in the following steps:

[0074] Step 1: Place SBC, NBE, PS, filler, softening oil, coupling agent, brightener or pigment and paraffin into a mixer at room temperature and stir at high speed to mix them evenly.

[0075] Step 2: The mixed material is put into a screw extruder and melt-extruded at 170°C to produce pellets, which are known as TPR colored or colorless pellets.

[0076] Step 3: After the granules and the cross-linking agent are fully mixed, the mixture is melt-hot-pressed and cross-linked on a molding machine at 185°C for 250 seconds. After cooling and demolding, the designed shoe outsole is obtained.

[0077] The formulations of corresponding Examples 1 to 4 and Comparative Examples 1 to 3 are shown in Table 1, and the physical properties of the shoe outsoles made of TPR granules are shown in Table 2.

[0078] Table 1: Formulas in Examples (parts by mass)

[0079]

[0080]

[0081] Note: “*” SBS-815 is a product of the synthetic rubber plant of Sinopec Baling Petrochemical Company, with a vinyl content of 16.4%. It is the main rubber used in existing TPR granules.

[0082] Table 2 Physical properties of the outsoles prepared in Examples 1 to 4 and Comparative Examples 1 to 3

[0083]

[0084]

[0085] Note: Adhesion strength refers to the peel strength between the vulcanized rubber and leather; the anti-slip coefficient is measured using both dry and wet methods. The examples in the table show that compared to outsoles made from SBC and NBE composite granules with high side branching unit content, outsoles made from SBS-815 composite granules exhibit lower anti-slip performance and adhesion strength. The vulcanized granules of the present invention exhibit excellent overall physical properties.

Claims

1. An NBE modified SBC shoe outsole material, characterized by: Component raw materials including SBC, NBE and excipients; The NBE has the structure of Formula 1: A I -B m1 A nn -B m2 A nn-1 …B mm-1 A n2 -B mm A n1 -B mm-1 A n2 ...B m2 A nn-1 -B m1 A nn -A II Formula 1 in, A represents a polyacrylonitrile block, and B represents a polybutadiene block; I, II, n1, n2...nn-1, nn represent the degree of polymerization of A, I or II is much greater than n1, n2...nn-1 or nn, and n1 to nn increase in sequence, 3≥n1≥0, nn>3; m1, m2...mm-1, mm represent the degree of polymerization of B, and m1 to mm increase in sequence, 0≤m1<3, mm≥3; I>II>3; The mass ratio of the butadiene block to the acrylonitrile block in the NBE is (55-40) / (45-60); The SBC is a styrene-conjugated diene copolymer; the mass fraction of the styrene unit in the styrene-conjugated diene copolymer is not less than 30%, and the mass percentage of the side branch unit in the conjugated diene unit is not less than 50%; The auxiliary materials include a cross-linking agent.

2. The NBE-modified SBC shoe outsole material according to claim 1, characterized in that: The NBE has a melt index of (0.1-8) g / 10 min at 200° C., a 300% modulus of stress greater than 1.0 MPa, a tensile strength greater than 10.0 MPa, an elongation at break of 700%, a permanent deformation less than 30%, a Shore A hardness of 55-60, and a glass transition temperature less than -15° C.

3. The NBE modified SBC shoe outsole material according to claim 1, characterized in that: The auxiliary materials include PS, inorganic filler, softening oil, coupling agent, whitening agent or pigment, cross-linking agent and paraffin.

4. The NBE modified SBC shoe outsole material according to claim 3, characterized in that: The inorganic filler is at least one of white carbon black, carbon black and calcium carbonate powder.

5. The NBE modified SBC shoe outsole material according to claim 3, characterized in that: The softening oil is white oil and / or naphthenic oil.

6. The NBE modified SBC shoe outsole material according to claim 3, characterized in that: The coupling agent is at least one of KH-550, silicon-69 or silicon-75.

7. The NBE modified SBC shoe outsole material according to claim 3, characterized in that: The whitening agent is fluorescent whitening agent OB, and the pigment is at least one of carbon black, ultramarine, iron red and disperse blue.

8. The NBE modified SBC shoe outsole material according to claim 3, characterized in that: The cross-linking agent is at least one of dicumyl peroxide, 1,1-di-tert-butyl cyclohexane peroxide and p-menthane peroxide.

9. The NBE modified SBC shoe outsole material according to any one of claims 1 to 8, characterized in that: The composition comprises the following raw materials in parts by weight: 100 parts of SBC; 20-30 parts of NBE; 10-30 parts of PS; 60-80 parts of filler; 30-80 parts of softening oil; 5-8 parts of coupling agent; 0.5-1.5 parts of brightener or pigment; 1-3 parts of paraffin wax; and 0.5-2.0 parts of cross-linking agent.

10. A method for preparing a shoe outsole using the NBE modified SBC shoe outsole material according to any one of claims 1 to 9, characterized in that: The following steps are involved: 1) SBC, NBE, PS, filler, softening oil, coupling agent, paraffin wax and brightener or pigment are mixed uniformly in a mixer at high speed to obtain a mixture; 2) The mixed material is melted and extruded through a screw extruder, and pelletized to obtain pellets; 3) After the granules are fully mixed with the cross-linking agent, they are melted and hot-pressed and cross-linked by an injection molding machine or a molding machine, and then cooled and demolded to obtain the shoe outsole.

11. The method for preparing a shoe outsole from an NBE modified SBC shoe outsole material according to claim 10, characterized in that: The melt extrusion temperature is 150-190°C.

12. The method for preparing a shoe outsole from an NBE-modified SBC shoe outsole material according to claim 10, characterized in that: The melting temperature in the melt hot pressing cross-linking molding process is 180-190° C., and the hot pressing molding or cross-linking molding time is 200-300 seconds.

Images