CN115521567A - NBE (N-butyl-diene monomer) modified SBC (styrene butadiene rubber) shoe outsole material and method for preparing shoe outsole by using same - Google Patents

Abstract

The invention discloses NBE modified SBC shoe outsole material and a method for preparing shoe outsoles by using the same. The NBE modified SBC shoe outsole material comprises butadiene-acrylonitrile rubber with thermoplastic elastic behavior, polystyrene-conjugated diene thermoplastic elastomer with higher side chain content and auxiliary materials, and the shoe outsole prepared by extruding, granulating, molding or extruding the NBE modified SBC shoe outsole material has higher slip limiting coefficient, and the bonding strength of the shoe outsole and a shoe upper fabric is especially outstanding without special surface treatment.

Description

NBE (N-butyl-diene monomer) modified SBC (styrene butadiene rubber) shoe outsole material and method for preparing shoe outsole by using same

Technical Field

The invention relates to a large sole material, in particular to an NBE modified SBC large sole material, and also relates to a method for preparing a large sole by using the NBE modified SBC large sole material, belonging to the technical field of sole material synthesis.

Background

The mass fraction of acrylonitrile combined with existing commercially available nitrile rubber (such as NBR3365, NBR1052 and NBR3355 produced by south emperor chemical company) is usually 25-42%, the Mooney viscosity is 30-90, the acrylonitrile and butadiene are copolymerized in emulsion at low temperature, the acrylonitrile and butadiene combined in the NBR molecular structure are randomly distributed, the crude rubber strength is low, the thermoplastic elastomer behavior is not available, the nitrile rubber is not suitable for being used as a sole material, and the vulcanized rubber has use value. For example, chinese patent CN103665265A, CN103450397A, CN104628955a, etc. all describe that acrylonitrile and butadiene (or/and third monomer) are copolymerized under emulsion condition to prepare nitrile rubber or modified terpolymer rubber; chinese patent (CN 110066481A) provides an application of nitrile rubber, and the components of the nitrile rubber comprise 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 to 0.8 portion of cross-linking agent DCP; 0.5-1 part of foaming crosslinking assistant; 0.2 to 0.5 portion of stearic acid and the like. Namely, it describes the vulcanization of nitrile rubber to be applied to oil resistant rubber products, and there is no report on the use of nitrile rubber as a polymer containing block or micro-block polyacrylonitrile bonded to molecular chain NBR and the use of existing commercially available NBR as a shoe material or a modified styrene-butadiene thermoplastic elastomer.

The traditional TPR sole material is a sole which is formed by blending and modifying a styrene-butadiene thermoplastic elastomer such as SBS with polystyrene, calcium carbonate powder, white oil, pigment and other functional additives through the processes of mixing, extruding, injection molding, mould pressing and the like, the common SBS is prepared by copolymerizing styrene and butadiene in the market, the model of the SBS is oil-filled and non-oil-filled such as 875, 675, 1475, 1487, 805, 815, 4452 and the like, the molecules of the rubber seeds do not contain polar groups and are also called non-polar rubber seeds, the main raw material in the TPR is SBS, the SBS is a framework of the whole sole material, and the main properties such as strength, elasticity and the like are provided for the sole material. At present, TPR sole materials are accepted by more and more manufacturers, merchants and consumers, and have the defects of low bonding force between the outsole and the upper fabric, easy degumming and poor skid resistance. For example, chinese patent (CN 105237822A) describes a formula of a sole material synthesized from natural rubber and SBS and a preparation method thereof, the formula comprises 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 part of diethylene glycol, 0.8-1.6 parts of a vulcanizing agent, 5-15 parts of softened oil and the like, the composite material has a use value after crosslinking and vulcanizing double bonds in rubber molecules by adopting peroxide, and the method adopts polyvinyl acetate (EVA) to modify SBS and polarize the composite material. Chinese patent (CN 107033520A) introduces a preparation method of wear-resistant SBS sole material, the sole material is composed of SBS, calcium carbonate, maleic anhydride, polyethylene glycol, polystyrene, resin and small materials, the preparation process of the sole is divided into 5 steps, the operation is complex, the method adopts maleic anhydride to graft SBS, polarizes the SBS, and is beneficial to polar adhesive to effectively bond the sole and vamp (such as leather) materials. The patent of 'development of rubber for SBS sole', zhang Changde et al, beijing chemical engineering, 2 nd 1994) describes that SBS is a non-polar material, and the affinity between SBS and various shoe making fabrics is poor, so that the defects that the surface of the existing adhesive needs to be chemically treated when the existing adhesive is used for bonding SBS sole, the adhesive is easy to peel and open, etc. cyclohexane is used as a solvent, SBS is grafted and modified by acrylate monomers, and the bonded SBS sole material and leather materials have bonding strength. Similarly, in documents such as the "production method of a TPR shoe material surface treatment agent", the polyurethane industry, 2013), ("application of a domestic polyurethane adhesive to a low-polarity shoe material", the polyurethane industry, 2002) and ("development of a PR surface treatment agent", a chinese adhesive, 2004), a large number of prior SBS/TPR shoe sole materials are reported to be capable of being pressed and adhered to a shoe upper fabric only by performing surface treatment on a bonding surface of a shoe sole and a shoe upper by using the polar surface treatment agent, and then coating a polyurethane adhesive.

In conclusion, the existing SBS/TPR sole materials are all non-polar materials, and the SBS modified by maleic anhydride or EVA has the defects of long preparation process, low grafting rate or easy crosslinking and condensation, and the like, and even if a small amount of grafting is carried out, the modified SBS still belongs to low-polarity macromolecules, and as the sole material, the modified SBS still can be coated with polyurethane for bonding to bond the upper fabric of the shoe after the chemical surface treatment is carried out on the injection-molded sole bonding surface; meanwhile, the degumming time of the prior TPR shoe upper is far shorter than the abrasion time of the sole, in addition, the content of the polybutadiene block vinyl unit in the prior SBS molecule is less than 18 percent, and the prepared sole has poor skid resistance. Therefore, the novel SBS or TPR sole material which has good slip resistance, easy adhesion, high adhesion strength and durability is worthy of development.

Disclosure of Invention

Aiming at the defects of the SBS or TPR sole material in the prior art, the invention aims to provide the large sole material for the shoes, which takes nitrile rubber with polarity and thermoplastic elastomer behavior and SBS with high vinyl unit content as main raw materials, the large sole material for the shoes is formed into the large sole with good wear resistance and slip resistance through blending, mould pressing and vulcanization, and the large sole material for the shoes has micro-crosslinking and higher molecular polarity, has good affinity with polar materials of vamps, and is beneficial to the shoe with lasting bonding force by using the existing adhesive under the condition that the large sole and the vamp are not subjected to surface treatment.

Another object of the present invention is to provide a styrene-conjugated diene elastomer (SBC), a thermoplastic butadiene-acrylonitrile elastomer (NBE) with thermoplastic elastomer behavior, and additives such as fillers, which are mixed and granulated (or composite material), and a method for preparing shoe outsole by using the composite material through mold pressing or injection molding, wherein the method or process has the characteristics of simple operation, low cost and easy industrial production.

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

In order to realize the technical purpose, the invention provides an NBE modified SBC shoe outsole material which comprises SBC, NBE and auxiliary materials;

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

Wherein the content of the first and second substances,

a represents a polyacrylonitrile block, B represents a polybutadiene block;

I. II, n1, n2 … … nn-1 and nn represent the polymerization degree of A, I or II is far larger than n1, n2 … … nn-1 or nn, and n1 to nn are increased in sequence, wherein n1 is more than or equal to 3 and more than or equal to 0, nn >; m1, m2 … … mm-1 and mm represent the polymerization degree of B, and m1 to mm are increased in sequence, m1 is more than or equal to 0 and less than 3, and mm is more than or equal to 3; i > II > 3.

In a preferred embodiment, the mass ratio of the butadiene block to the acrylonitrile block in the NBE is (55 to 40)/(45 to 60).

Preferably, the melt index of the NBE at the temperature of 200 ℃ is (0.1-8) g/10min, the 300% stress at definite elongation is more than 1.0MPa, the tensile strength is more than 10.0MPa, the elongation at break is 700%, the permanent deformation is less than 30%, the Shore hardness A is = 55-60, and the vitrification temperature is less than-15 ℃.

As a preferred embodiment, the SBC is a styrene-conjugated diene copolymer. The SBC is further preferably a triblock-type derivative copolymer of polystyrene-butadiene and/or isoprene, such as styrene-based elastomers known to those skilled in the art as SBS, SIS, SIBS, and the like. Preferred SBCs have a mass fraction of vinyl units in the polybutadiene block of 58 to 65%, such as SBS-179 (with a mass fraction of vinyl units in its diene units of 60%), SIS-1209 (with a mass fraction of isoprene incorporated of 70%), polystyrene-butadiene and isoprene-polystyrene (SIBS) with a mass fraction of side chains in the soft block of not less than 50%, such as SIBS-935 and SIBS1203, products manufactured by the rubber industries of the petrochemical company holy, china.

As a more preferable mode, the mass fraction of the styrene unit in the styrene-conjugated diene copolymer is not less than 30%, and the mass percentage content of the side chain unit in the conjugated diene unit is not less than 50%. In the prior art, when the content of the side chain unit in the conjugated diene unit of the polystyrene-conjugated diene rubber such as solution polymerized styrene-butadiene rubber (SSBR) is more than 57% by mass, the vulcanized rubber has good wet skid (or slip) resistance, which is a necessary condition in the preparation of high-performance tires, and the selection of the styrene elastomer with high content of side chain in the conjugated diene polymerization unit is a basic element of the shoe outsole prepared by the invention, which has slip resistance.

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

As a preferable mode, the inorganic filler is at least one of white carbon black, carbon black and calcium carbonate powder. The inorganic filler is used as a reinforcing agent, preferably the reinforcing agent is at least one of white carbon black, carbon black and calcium carbonate powder, and the specific surface area is 280-320 m ² Per g of at least one of Rodiya 175MP, determined as siliconized H810, carbon black N330 and light or heavy calcium carbonate powder with the mesh number not less than 1000 meshes. The thickness matching of the filling material is beneficial to enhancing the strength of the composite sole material and reducing the cost. In the preferred filler, calcium carbonate/white carbon black (and/or carbon black) by weight = (2-4)/1.

As a preferred embodiment, the softening oil is a white oil and/or a naphthenic oil. The softening oil is preferably white oil or naphthenic oil, such as commercial industrial white oil # 680#, # 460#, N4010, N4006 and # 100.

As a preferred scheme, the coupling agent is at least one of KH-550, silicon-69 or silicon-75. The preferred coupling agent can effectively couple and compatibilize the polar reinforcing filler and the rubber, and simultaneously increase the powder eating rate of the rubber to powder.

As a preferred embodiment, the whitening agent is an optical brightener OB, and the pigment is at least one of carbon black, ultramarine, iron red, and disperse blue.

As a preferred scheme, the cross-linking agent is at least one of dicumyl peroxide, 1,1-di-tert-butyl cyclohexane peroxide and p-menthane peroxide.

As a preferable scheme, the NBE modified SBC shoe outsole material comprises the following raw materials in parts by mass: 100 parts of SBC; NBE 20-30 parts; 10-30 parts of PS; 60-80 parts of a filling material; 30-80 parts of softening oil; 5-8 parts of a coupling agent; 0.5 to 1.5 portions of whitening agent or pigment; 1-3 parts of paraffin; 0.5 to 2.0 portions of cross-linking agent.

The invention also provides a method for preparing the shoe outsole by using the NBE modified SBC shoe outsole material, which comprises the following steps:

1) Uniformly stirring and mixing SBC, NBE, PS, a filling material, softening oil, a coupling agent, paraffin and a whitening agent or pigment in a mixer at a high speed to obtain a mixture;

2) Melting and extruding the mixture through a screw extruder, and pelletizing to obtain granules;

3) And (3) fully mixing the granules with a cross-linking agent, carrying out fusion hot-pressing cross-linking molding through an injection molding machine or a mould pressing machine, cooling and demoulding to obtain the shoe outsole.

Preferably, the melt extrusion temperature is 150 to 190 ℃.

Preferably, the melting temperature in the melting hot-pressing cross-linking forming process is 180-190 ℃, and the hot-pressing forming or cross-linking forming time is 200-300 seconds.

NBE according to the invention has the following "molecular chain" distribution:

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

Wherein "A" represents a polyacrylonitrile block, "B" represents a polybutadiene block, I, II, n1, n2 … … nn-1, nn represent the degree of polymerization of A, m1, m2 … … mm-1, mm tableThe polymerization degree of B is shown, and the polymerization degrees are positive integers which are not less than 0; and I and II are much larger than n1, n2 … … nn-1 and nn, A _I And A _II Representing homopolyacrylonitrile blocks of relatively large molecular weight at both ends of the nitrile copolymer (e.g. A) _I Number average molecular mass Mn of>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 Represents a random copolymer block of acrylonitrile and butadiene, and 0. Ltoreq. M1<3，mm≥3，3≥n1≥0，nn>3; the random copolymer block comprises a plurality of tiny polyacrylonitrile blocks and polybutadiene blocks, and the lengths of the tiny blocks show gradual change rules, such as the length of the tiny polybutadiene block is represented by B _m1 To B _mm The length of Bmm is gradually increased, the butadiene homopolymerized block with relatively large polymerization degree is formed, and the length of the polyacrylonitrile blocks is increased from A _n1 To A _nn The length of the acrylonitrile-butadiene copolymer is gradually increased, an1 is a polyacrylonitrile block with relatively small polymerization degree, one end or two ends of the acrylonitrile-butadiene copolymer are both polyacrylonitrile blocks with relatively high polymerization degree and are equivalent to hard blocks, and a polybutadiene block doped in the middle of a random copolymerization block of acrylonitrile and butadiene is equivalent to soft blocks, so that the whole acrylonitrile-butadiene copolymer shows thermoplastic elastomer behavior.

The NBE provided by the invention is prepared by three-stage polymerization:

the emulsion polymerization system employed: consists of deionized water, an emulsifier, a dispersant, an electrolyte, a molecular mass regulator, a deoxidizer, an oxidant, a reducing agent and an activator; the emulsifier is hydrogenated rosin potassium and potassium oleate; the dispersing agent is sodium methylene dinaphthalene sulfonate, and 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 hydrosulfite; the oxidant is at least one of high-activity p-menthane peroxide and pinane hydroperoxide; the reducing agent is a rongalite; the activating agent is EDTA-iron sodium.

The polymerization conditions were: the polymerization reaction raw materials are added in three sections under the temperature of 20-30 ℃ and the polymerization pressure of 0.3-0.5 MPa:

one-stage polymerization: adding acrylonitrile monomer (A) with the total setting amount of 30-50% for homopolymerization for 3.5-4 h; in the process, only part of acrylonitrile is subjected to homopolymerization, the conversion rate of A is preferably controlled to be more than or equal to 70 percent, and the number average molecular mass Mn of the polyacrylonitrile block is more than 12000;

and (2) secondary polymerization: adding a set amount of butadiene (B) to carry out polymerization reaction for not less than 3h; the process comprises the steps of growing molecular chains of B and polyacrylonitrile chain links (PA) generated in the first stage of polymerization and copolymerizing unreacted A and B, wherein the conversion rate of B is preferably controlled to be more than 80%; wherein, the combination of A and B remained in the polymerization environment, A is distributed in the copolymer molecule in a descending gradient manner to form soft segment chain links;

three-stage polymerization: adding the total set of the remaining 50-70% of A to the polymerization environment for copolymerization reaction, wherein the polymerization reaction time is not less than 3.5h, and the total monomer conversion rate of the polymerization is not less than 97%; the process comprises a chain growth reaction of A and chain links generated in the second stage and a copolymerization reaction of B and A which are not reacted in the second stage reaction; in the process, the residual quantity of B is less, and B combined in the growth of a copolymerization reaction chain is distributed in a polymer molecule in a descending sequence along with the dynamic change of the concentration of a monomer in a polymerization environment and the difference of the polymerization rates of A and B;

after the polymerization reaction is finished, the polymer latex is discharged, a certain amount of antioxidant is added and uniformly stirred, the latex is slowly added into a solution dissolved with dicyanodiamide formaldehyde condensation compound, concentrated sulfuric acid and water at 50-60 ℃ in batches for coagulation, the mixture is added and stirred, a small amount of residual unreacted monomer acrylonitrile is dissolved in a water phase, and milky white granular micelle can be obtained after 10 min.

The PS related by the invention is a hard polystyrene resin commonly known in TPR prepared by SBS in the technical field, and can be selected from polystyrene foam recycled granules or Polystyrene (PS) prepared by a bulk method or a suspension method, such as commercially available PH-888G and other commodities.

The paraffin wax is used as a release agent.

It is worth mentioning that the polymers used in the formulation of the outsole material of the invention are all thermoplastic elastomers, therefore, even if no cross-linking agent is used, the NBE, PS and SBC polymer macromolecules in the outsole after injection molding of the prefabricated extruded composite granules (TPR) are in a sea-island structure, the outsole has the usable or applicable performance, but the double bonds in NBE and SBC molecules can be effectively micro-crosslinked by properly adding a small amount of cross-linking agent in the composite granules, which is more beneficial to improving the compatibility of NBE and SBC, and simultaneously, the density of the cross-linking network of the injection molding or die-molding body is further increased, and the strength is improved.

The method for preparing the shoe outsole by using the NBE modified SBC shoe outsole material provided by the invention comprises the following steps:

the first step is as follows: SBC, NBE, PS, filler, softening oil, coupling agent, whitening agent or pigment and paraffin are put into a mixer at room temperature to be stirred and mixed evenly at high speed.

The second step is that: the mixture is put into a screw extruder to be melted and extruded and granulated at the temperature of 150 to 190 ℃, namely the TPR colored or colorless granules which are known by people.

The third step: after the granules and the cross-linking agent are fully mixed, the mixture is melted, hot pressed and cross-linked and formed on an injection molding machine or a molding press at the temperature of 180-190 ℃, the heat setting time (or the cross-linking time) is 200-300 seconds(s), and the shoe outsole with the designed style can be obtained after cooling and demolding.

The connecting agent for bonding the shoe outsole and the upper fabric prepared by the invention is preferably a polyurethane adhesive, such as commercially available south light resin adhesive.

The composite granular material and the breaking strength of shoe outsole prepared by the invention>6MPa, elongation at break>200% tear strength>54N/mm abrasion<135mm ³ Dry type slip coefficient>1.2 Peel Strength (glue and cowhide)>65N/mm。

Compared with the prior art, the technical scheme of the invention has the following beneficial effects:

compared with the defects of the TPR consisting of the existing SBS and the filling material, the invention selects the styrene-conjugated diene block thermoplastic elastomer (SBC) with a high side branched chain as the main rubber, is beneficial to the vulcanization or tabletting rubber and products and has higher anti-slip performance; simultaneously selects novel nitrile rubber with thermoplastic elastomer behavior

(NBE) is used as an auxiliary glue source to be blended with SBC, and the aim is to improve the molecular polarity of the low-polarity polymer SBC and enhance the lasting and high adhesive force of the sole and upper fabrics prepared by the blended glue and the outsole made of the existing adhesive under the condition of not carrying out surface cleaning and polishing treatment; the small amount of cross-linking agent is beneficial to micro-crosslinking of double bonds in NBE and SBC molecules, and the compatibility of the NBE and the SBC and the tensile strength of the sole are improved.

The outsole of the shoe has the advantages of good anti-slip performance, high strength, high adhesion strength between the outsole and upper fabrics, tear resistance, easy control of the composite granulation process of NBE, SBC, fillers and auxiliaries, short process, simple and convenient operation and low cost; meanwhile, the granulation to the shoe outsole manufacturing molding is simple and convenient, the molding time is short, the industrialization is easy, and the granulation can be completed by utilizing the existing mature process.

Detailed Description

The present invention is illustrated by the following examples, which are not intended to limit the scope or practice of the invention.

The number average molecular weight of the polymer was measured by Gel Permeation Chromatography (GPC) in the following examples; determining the polymer glass transition temperature (Tg) using a differential thermal analyzer (DSC); by means of H ¹ -NMR spectroscopy to determine the microstructure of the polymer; measuring the physical properties of the vulcanized rubber by adopting an INSTRON tensile machine; the adhesive strength (N/mm) was measured according to the DW-22GT-TCS2000 (100. + -. Mm/min); DIN abrasion (mm 3) was determined by the DW-15GT-7012-D rotary (40. + -.1) r/min (10. + -. 0.2) N method; the slip coefficient was measured by DW-09BL-312 by dry and wet methods.

Example 1

1.8 liters of deionized water was charged into a 5 liter polymerization reactor, followed by 70mL of a 15.0 wt% potassium oleate solution, 50mL of a 25.0 wt% disproportionated rosin potassium solution, 17mL of a 2.0 wt% ferric EDTA sodium salt solution, 15mL of a 10.0 wt% sodium methylenedinaphthalene sulfonate aqueous solution, 20mL of a 10.0 wt% potassium chloride aqueous solution, 5mL of a 5 wt% sodium dithionite aqueous solution, 16mL of a 6.5 wt% sodium formaldehyde sulfoxylate aqueous solution, 1.3g of p-menthane peroxide, and t-dodecyl sulfur3.8g of alcohol, nitrogen is used for pressing the auxiliary agent into the polymerization kettle, stirring is started, and the reaction liquid is controlled to 10-20 ℃. At this time, 230g of acrylonitrile was introduced into the polymerization reactor by nitrogen gas and reacted for 4 hours, a polymer emulsion sample was taken and the polymer was precipitated with absolute ethanol, the conversion of the polymerized monomer after filtration and drying was 78.2%, and the number average molecular weight of the polymer was Mn ₁ And =11200, at this time, 805mL (500 g) of butadiene is added into the polymerization kettle, the polymerization kettle is kept under the pressure of 0.3-0.5 MPa for 4 hours, 270g of the residual acrylonitrile in the third section of design amount can be added into the polymerization kettle when the monomer conversion rate is 82.3%, the copolymerization reaction is carried out for 3.5 hours, at this time, the monomer conversion rate is measured to be 98.4%, and the reaction can be visually ended after the polymerization reaction is not heated and changed.

Unloading, adding 3.5g of antioxidant 1076 into latex, mixing uniformly, slowly adding the latex into a solution formed by 40g of dicyanodiamide formaldehyde condensate dissolved at 50-60 ℃, 15g of concentrated sulfuric acid and 30 liters of water in batches for coagulation, adding and stirring, dissolving a small amount of residual unreacted monomer acrylonitrile in a water phase, and obtaining milky white granular micelles after 10 min.

As a result, it was found that NBE (designated NBE-1) produced had a mass fraction of vinyl units in the molecule of 11.5%, a mass fraction of incorporated acrylonitrile of 49.6%, a melt index (MFR) of 0.16g/10min, a 300% stress at definite elongation of 1.2MPa, a tensile strength at break of 10.3MPa, an elongation at break of 760%, a permanent set of 23%, a hardness (Share A) of 53, and a glass transition temperature of-18.6 ℃.

Example 2

The relevant conditions in example 1 were not adjusted to a great extent, and the amount of the auxiliary agent used was controlled within the limits of the present invention, except that the acrylonitrile added in the first and third stages was 280g, and the tertiary dodecyl mercaptan was 4g.

As a result, the number average molecular mass Mn of the first-stage polymer was determined ₁ =12400 mass fraction of vinyl units in NBE after coacervate drying (nominally NBE-2) 11.4% molecular weight, bound acrylonitrile mass fraction 52.6%, glass transition temperature-16.4 ℃, MFR 2.53g/10min,300% stress at definite elongation 1.23MPa, tear strength 11.4MPa, tear elongation 740%, permanent set 22%, hardness (Share A) 54.

Example 3

The relevant basic conditions in example 1 were kept unchanged, except that 300g of acrylonitrile, 450g of butadiene and 4.5g of tert-dodecanethiol were fed to the first and third stages.

As a result, the number average molecular mass Mn of the first-stage polymer was determined ₁ =14500, NBE after coagulation drying (designated NBE-3) molecular weight fraction of vinyl unit 11.1%, bound acrylonitrile weight fraction 57.8%, glass transition temperature-14.7 ℃, MFR 4.85g/10min,300% stress at definite elongation 1.32MPa, tensile strength 12.6MPa, tensile elongation 730%, permanent set 28%, hardness (Share A) 56.

Example 4

The relevant basic conditions in example 3 were kept unchanged, except that 290g of acrylonitrile were fed to the first and third stages, 400g of butadiene were fed to the second stage, and 5.0g of t-dodecyl mercaptan was fed.

As a result, the number average molecular mass Mn of the first-stage polymer was determined ₁ =11600, NBE after drying (demarcated NBE-4) molecular weight percentage of vinyl unit 10.7%, combined acrylonitrile weight percentage 59.3%, glass transition temperature-13.6 ℃, MFR 7.46g/10min,300% stress at definite elongation 1.35MPa, tensile strength at break 13.5MPa, tensile elongation 720%, permanent deformation 28%, hardness (Shao A) 58.

Application examples

NBE-1, NBE-2, NBE-3 and NBE-4 prepared above are respectively mixed with SBC elastomers such as SBS-179, SIS-1209, SIBS-935 and SIBS1203 and at least one of SBS with low side vinyl mass content in the molecular chain as a comparison sample and corresponding fillers and auxiliary agents, and are prepared into corresponding TPR granules by screw extrusion molding.

The specific shoe outsole preparation process comprises the following steps:

the first step is as follows: SBC, NBE, PS, filling materials, softening oil, coupling agents, brightening agents or pigments and paraffin are put into a mixer at room temperature to be stirred and mixed evenly at high speed.

The second step is that: the mixture is put into a screw extruder to be melted and extruded and cut into granules at 170 ℃, namely the TPR colored or colorless granules which are commonly known.

The third step: after the granules and the cross-linking agent are fully mixed, the mixture is melted, hot-pressed and cross-linked and formed on a lower die press at 185 ℃, the heat setting time is 250 seconds(s), and the shoe outsole with the designed style can be obtained after cooling and demoulding.

The formulations of the respective examples 1 to 4 and comparative examples 1 to 3 are shown in Table 1, and the physical properties of the outsole made of TPR pellets are shown in Table 2.

Table 1 formulation in examples (parts by mass)

Note: "SBS-815 is a product of synthetic rubber factory of China petrochemical Balng petrochemical company, the mass fraction of vinyl is 16.4%, and the product is a main rubber of the existing TPR granules.

TABLE 2 physical Properties of shoe outsoles prepared in examples 1 to 4 and comparative examples 1 to 3

Note: the bonding strength is the peeling strength of vulcanized rubber and leather; the slip resistance coefficient was measured by a dry method and a wet method. From the examples in the table it can be seen that: compared with the shoe outsole made of the SBC and NBE composite granulated material with high side-branched unit content, the shoe outsole made of the SBS-815 composite granulated material has lower slip resistance and bonding strength; the shoe outsole manufactured by vulcanizing the granules has good comprehensive physical properties.

Claims (15)

1. An NBE modified SBC outsole material is characterized in that: the component raw materials comprise SBC, NBE and auxiliary materials;

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

Wherein the content of the first and second substances,

a represents a polyacrylonitrile block, B represents a polybutadiene block;

I. II, n1, n2 … … nn-1 and nn represent the polymerization degree of A, I or II is far larger than n1, n2 … … nn-1 or nn, and n1 to nn are increased in sequence, wherein n1 is more than or equal to 3 and more than or equal to 0, nn >; m1, m2 … … mm-1 and mm represent the polymerization degree of B, and m1 to mm are increased in sequence, m1 is more than or equal to 0 and less than 3, and mm is more than or equal to 3; i > II > 3.

2. The NBE modified SBC outsole material of claim 1, wherein: the mass ratio of the butadiene block to the acrylonitrile block in the NBE is (55-40)/(45-60).

3. The NBE modified SBC outsole material of claim 1, wherein: the melt index of NBE at 200 ℃ is (0.1-8) g/10min,300% stress at definite elongation is more than 1.0MPa, the breaking strength is more than 10.0MPa, the breaking elongation is 700%, the permanent deformation is less than 30%, the Shore hardness is A = 55-60, and the glass transition temperature is less than-15 ℃.

4. The NBE modified SBC outsole material of claim 1, wherein: the SBC is a styrene-conjugated diene copolymer.

5. The NBE modified SBC outsole material of claim 4, wherein: the mass fraction of styrene units in the styrene-conjugated diene copolymer is not less than 30%, and the mass percentage content of side chain units in the conjugated diene units is not less than 50%.

6. The NBE modified SBC outsole material of claim 1, wherein: the auxiliary materials comprise PS, inorganic filling materials, softening oil, coupling agents, whitening agents or pigments, cross-linking agents and paraffin.

7. The NBE modified SBC outsole material of claim 1, wherein: the inorganic filler is at least one of white carbon black, carbon black and calcium carbonate powder.

8. The NBE modified SBC outsole material of claim 1, wherein: the softening oil is white oil and/or naphthenic oil.

9. The NBE modified SBC outsole material of claim 1, wherein: the coupling agent is at least one of KH-550, silicon-69 or silicon-75.

10. The NBE modified SBC outsole material of claim 1, wherein: the whitening agent is an optical brightener OB, and the pigment is at least one of carbon black, ultramarine, iron oxide red and disperse blue.

11. The NBE modified SBC outsole material of claim 1, wherein: the cross-linking agent is at least one of dicumyl peroxide, 1,1-di-tert-butyl cyclohexane peroxide and p-menthane peroxide.

12. The NBE modified SBC footwear substrate material according to any one of claims 1 to 11, wherein: the composite material comprises the following raw materials in parts by mass: 100 parts of SBC; NBE 20-30 parts; 10-30 parts of PS; 60-80 parts of a filling material; 30-80 parts of softening oil; 5-8 parts of a coupling agent; 0.5 to 1.5 portions of whitening agent or pigment; 1-3 parts of paraffin; 0.5 to 2.0 portions of cross-linking agent.

13. The method of preparing an outsole of an SBC outsole material modified with NBE according to any one of claims 1 to 12, wherein: the method comprises the following steps:

1) Uniformly stirring and mixing SBC, NBE, PS, a filling material, softening oil, a coupling agent, paraffin and a whitening agent or pigment in a mixer at a high speed to obtain a mixture;

2) Melting and extruding the mixture through a screw extruder, and pelletizing to obtain granules;

3) And (3) fully mixing the granules with a cross-linking agent, carrying out fusion hot-pressing cross-linking molding through an injection molding machine or a molding press, cooling and demolding to obtain the shoe outsole.

14. The method of preparing an outsole of an SBC outsole material modified with NBE according to claim 13, wherein: the melt extrusion temperature is 150-190 ℃.

15. The method of preparing an outsole of a shoe using the NBE modified SBC outsole material of claim 13, wherein: the melting temperature in the melting hot-pressing cross-linking forming process is 180-190 ℃, and the hot-pressing forming or cross-linking forming time is 200-300 seconds.