GB2212809A

GB2212809A - Process for producing shoesole material with thermoplastic character and improved features.

Info

Publication number: GB2212809A
Application number: GB8727713A
Authority: GB
Inventors: Gyula Murlastis; Mariann Szulman; Gyoergy Marton; Kocsis Jozsef Karger; Miklos Schober; Balazs Kozma; Laszlo Maczo; Jenoe T Kovacs; Julianna Toth
Original assignee: BOER ES CIPOEIPARI KUTATO FEJL; CIPOEGYAR TISZA; Taurus Gumiipari Vallalat
Current assignee: BOER ES CIPOEIPARI KUTATO FEJL; CIPOEGYAR TISZA; Taurus Gumiipari Vallalat
Priority date: 1986-10-10
Filing date: 1987-11-26
Publication date: 1989-08-02
Anticipated expiration: 2007-11-26
Also published as: HU197338B; DE3734259A1; GB2212809B; CS270574B2; AT392281B; ATA31788A; CS732687A2; YU185887A; IT8722196A0; BG47025A3; DE3734259C2; RO103958B1; HUT46049A; GB8727713D0; IT1222855B

Description

r r) r 1 L 2 1 2 8J.0 9 MAT PROCESS FOR PROOUCING SHOESOLE 1ERIAL WITH

THERM,:

PLASTIC CHARACTER AND IMPROVED FEATURES The invention relates to a process LCr producing shoesole material with thermoplastic cha:acter and improved features. Under improved features resistance to oil and chemicals, flowability and ageing resistance are meant.

Predominant majority of thermoplastic shoesole materials f-or the shoe industry is made by using block- copolymers based cn styrene/diene - f irst of all styrenef/butadiene-, in 4-dj) the P01YS Lyrene ratio being present in form Of 2 block lies in the range between 25 and 35 mass-%. In addition, howeve:

infreqjently and exclusively for producing soles with 2 inicrocell fcaim structure, ethylene/vinlvl-acetate (E/VAC) used to be.applied (e.g. BE-PS 891 480).

Block-copolymers on styrene/diene basis represent the oldest members of the family of thermoplastic elastomers, they are produced in anionic or vital polymerization. In the multi- component sole-mixtures for the shoe industry in addition to said thermoplastic elastomer as further components other polymers, plasticizers, fillers, processing promoting additives, ageing inhibitors, pigments, other additives, in certain cases foaming agents are contained.

1) 4 Among the disadvantageous characteristics of the sole-,-.-iaterials made with thermoplastic elastcmers on styreneldiene basis let us mention most the disadvantageous resistance to oil and chemicals, weari- some processing due to restri%cted flowability in the melt state (injection moulding), as well as tendency to ageing resulting necessarily from the presence of unsaturated double bands. 'En certain cases the abovementioned disadvantages are accompanied by shrinkage of form, as shrinkage of the s-le-rr.ixture is most sensitive to even small quantitativet chalrlwes o.f the components and depends fundamentally on the chemical structure of the ther,-,,cplia-c-4L. .'Lc on styrene/butadiene basis (i.e. segment is within the block, linear or star-shaped structure.

I' difficulty lies 4 de A further source c. An that to their particular production technology only a few company is able to produce block copolymers TPS on styrene/diene basis (ANIC, FINA, PHILLI. PETROLEUM, SHELL), which leads in a given case to the defencelessness of the processing respectively applying companies.

In technical literature several examples are to be found for increasing the resistance to oil and chemicals of the sole-materials made with styrene/diene block-copolymers. The US-PS 4 209 594 describes a process, in course of which polystyrene inoculated with alkyl-acrylate is used as additive, 1 1 3 - in the US-PS 4 225 500 chlorinated polyethylene (CPE) is used fo, the same purpose in addition to usual receptural components. Besides said polar additives crystalline polyolefines, such as high-density polyethylene (NSPE) (US-PS 4 216 132), linear low-density polyethylene (LKSPE) (US-PS 4 495 323) are considered effective for increasing the resistance to oil. An example is also known from technical literature, according to which nct a polar or strongly crystalline thermoplastic synthetic Material is used, but a polar thermoplastic elastomer, 1 y such as carboxylated syterene/butadiene block-ccpc.

is recoMmended (US-PS 4 409 357). Comr-ncn drawl.ack me.

of said systems can be characterized unter -Uhe heaj -line ccmpatibillity. The not properly c=p@tit'le components or those which could not or cannot be rendered compatible in course of mixing, may result in the unfavourable resistance to folding of the sole-material, eventually in scaling or break.

Improvement of injection moulding respectively processing becomes possible in two ways. The use of slipping agents of metallic soap type is rather restricted, as wandering to the surface considerably deteriorates stickiness of the sole-material. As a consequence, consumers prefer the use of flowabilit increasing agent of polymer type, just as polystrene and shockproof polystyrene (see Japanese Patent Application 80.116 944 or the Czechoslovakian Patent 4 189 445), which serve simultalneously for the adjustment of the hardness of the final, product. In part-icular, 1 examples relating to the use of poly(-Z-methyl-styrene) are known (US-PS 4 409 357 and 4 495 323). However, homogenization of polystyrene and styrene copolymers in the mixture is most wearisome. as this process becomes possible only in special itwo- worm mixing extruders.

Although introduction of crystalline poly- ethylenes (US-PS 4 216 132 and 4 4015 323) may also increase flowability of the mixture, their presence affects negatively adherence of the SO'Le-Mat- L The Cited Czechoslovak ian patent tries to elir.-.in2te said defficiency by using E/VAC. As a matter of fact, provement of adherence is intended to achieve im,. by using polymers inoculated with pola.- monomers (e.g. US-PS 4 209 594) or polar polymers (e.g. CFE according to the US-PS 4 225 500), as well as thermoplastic elastomers having carboxy groups at their 20 ends (US-PS 4 409 357).

To eliminate the presence of double bonds leading to ageing, US-PS 4 209 594 recommends the application of hydrogenated, i.e. subsequently saturated styrene/diene rubber. Another possibility for removing double bonds lies in vulcanization performed, simultaneously with sole-formation, which involves necessarily losing of thermoplastic character and possitility of repeated processing. This phenomenon occurs with a g e., n g f U 11 v vulcanizable sole materdal mixtures on styrene/butadiene rubber (SBR basis containing the components in a random distributicn (HU-PS 182 250).

Summing up prior arts, it can be stated that no sole material to be used in the shoe industry having been prepared by using thermoplastic elastomers, on styrene/diene basis is known, which could be characterized by proper resistance to oil and chemicals, flowability in the melt state and resista7ce to, simultaneously meeting the requirements in respect to durable foldability and adherence -Ficulty lies in that the manufacturer etc. A further Oif.

the mercy of the suppliers of scle material is at L o Lhe elastomers.

The aim of the invention is to produce a sole material with a thermoplastic character, which - when comPl2red to materials having been prepared by using traditional styrene/butadiene block-copolymers - shows a better resistance to chemicalsand ageing, - can be easily processed.

simultaneously it A further aim of the invention lies in producing this sole-material without applying block-copolymers on styrene/diene basis.

Further aim of the invention lies in that this improved thermoplastic sole-material could be manufactured by means of the usual equipments of the rubber indjustry without any difficulty.

6 - The invention is based on the recognition, that a sole material meeting all the requirements can be obtained, in so far the styrenei"butadiene rubber (56R) with static monomer distribution is plasticized - eventually in presence of other diene rubbers -, with crystalline, inoculated and/or not-inoculated polyolefine and/or ocolefine copolymer, eventually other additives known per se, in the presence of a peroxydic or sulphuric vulcanizing system, during mixing i.e. subjecting to shearing and pressure at a tempe- rature above the softening point of po-lyolefine.

A further recognition of the inventicn +1 e -ics of h lies in that the flowing charactezist sole material thus obtained can be adjusted in ccmipliance with prevailing requirements by the proper selecticn of the melt-index of the polyolefine applied, and Mooney-viscosity of the used rubber, as well as of quality and quantity of the vulcanizing system.

For those skilled in art it may be surprising, that inspite of the cros5-1inking agents applied a material with thermoplastic character can be obtained, which can be easily processed due to its good flowabili ty. According to experiences namely the formation of a not fusible material could be expected.

Furtheron, it is surprising, that by using diene rubbers being not resistent to oil and chemicals - 7 a product with improved resistance to oil and chemicals can be obtained.

A further surprising element of the invention lies in that by mixing polar rubbers and apolar olefine in accordance with the invention a well compatible system could be obtained.

At last, it is considered as surprising, that the product having been obtained by the process according to the invention is well-resistant to age 4 Lng, as presence of the vulcanizing agents:_ght to Cause the increased ageing ci the polyole'L.-Lne.

Summing up what has been said, the invention relates to a process for producing 2 thermop'12StiC sole material showing improved features, when ccm.pared to that made by using block-polymers on styrene/buta-moplastic diene basis, by applying 40 7 60 mass-% the.7 fine, 60-40 mass-% diehe rubber, 0 - 20 mass-% polyole. thermoplastic polystyrene and/or styrene copolymer, 0.1 - 600 mass-% plasticizers, filler, auxiliary materials, dyestuff, cross-linking agent known per se and other additives, by using one or more members thereof; the process comprising plasticizing as thermoplastic polyolefine polar inoculated polyolefine, polar ol--olefine copolymer, apolar polyolefine, respectively the mixture thereof having a melt index in -'[he range between 0.1 and 30 dg/min, when measured at 190 CC under a load of 21.2 N, with a crystalline ratic above 5 mass-%, wherein relative proportion of polar: apolar olefines amounts to 1:1 the most, with a rubber an static styrene/butadiene and/or ce-methyl-styrene/butadiene copolymer basis serving as diene rubber, wherein the content of styrene respectively styrene-derivative is maximally 10 - 50 mass-%, their Mooney viscosity lies in the range between 25 and 65 Mooney grade at 100 0 C, measured with a rotor indicated with L, after the expiration of four minutes in certain cases with other diene rubber, 5UPPOsed that the prcportion of SBR and other diene rubbers is 1:1 the most, by subjecting to shear and pressure at a temperatu.-e above the softening point of the polyolefine having tening point, in the presence of the highest S04LL peroxydic or -gulphuric cross-linking agents.

In sense of the invention as polar polyclelfine out of the inoculated polyclefines advantageously maleized polyolefine (inoculated with maleic acid or malic acid anhydride), out of the copolymer types advantageously ethylene/vinyl-acetate copolymer, ethylene/ethyl acrylate WEA) copolymer are used, out of the apolar types linear low and high density polyethylene, polypropylene homo- and copolymers, as well as the combination thereof are recommended.

As diene rubber, in addition to the obligaiory application of SBR-type5 polybutladiene (BR), polyisoprene (IR), natural rubber CNR), as well the Comtin2tion thereof can be used.

9 - In accordance with the invention out of the peroxidic systems dicumyl peroxyde, 1,3-bis/t.-butylperoxy-isopropyl/benzene, 2,5-dimethylhexane-2, 5-di-t.-butylperoxyde; 2,5-dimethylhexine-3+2,5-di-t.-butylperoxyde etc. can be advantageously used; out of the sulphuric types surface treated sulphur, colloidal sulphur, as well as sulphur-donor compounds can be used together with known accelerator systems.

1.0 Expediently, the sole-materi2l according to the invention is prepared 50, that firstly pclyclefine is charged into the mixer being usual in the rubte, industry, thereafter the rubber and the other adc"I.6ives (filers, plasticizers, dystuff etc.) are adted; thereafter is waited still the temperature of the mixture exceeds the softening point of the poLyclefine due to external heating and/or by the internal friction caused by the components according to the receipt, thereafter cross-linking agent is added.

The warm material leaving the mixer is lapped, cut into strips for further use, or made-up in form of granules.

Main advantages of the process according to the invention are, as follows:

- difficultly produced, difficultly available expensive block-copolymers on styrene/butadiene basis respectively sole materials manufactured therewith can be replaced with a mixture prepared - from cheap thermoplastic synthetic material produced in large mass and from several types of rubbers. since by using the process according to the invention a shoesole material for direct further-processing can be producad, considerable energy and material saving can be achieved in comparison with tChe processes which are working with styrene/ butadiene block-copolymers or by adding these copolymers. In this case namely sole-materJLal is formed on mixing extruders requiring considerable tion investmerlit. and labour, whereby energy consumpt surpasses that of the mixers of the rubber industry. Material savings appear in the fEact that while with mixers usual in the rubber industry - operating discontinuously - switchingover to an other quality, colour etc. may be performed from one charge to the other, continuously operated extruders require complete running out and cleaning. in comparison to the sole- material prepared from the usual block-copolymers on styrene/diene basis the product prepared in accordance with the invention shows improved resistance to oil and chemicals; flaving properties of the sole-material according to the invention are most advantageous, realiza- C 11 - tion of the prccess can be brought in compliance with prevailing requirements, e.g. by changing the receipt; tendency to ageing of the sole-material having been prepared according to the process of the invention is far less both under artificial and natural conditions, than that of the mixture containing styrene/butadiene block-copolymers serving as basis of comparison. shrinkage of the sole-material gained with the process according to the invention can trol be adjusted and cont Lled; ing the sole mnaterial having been prepared af ord.

4.

to the inventicn can be glued more easily, its abrasion resistance to wear, additional tensile strength, permanent folding and slip-proofness are better, than those of the products made with block-copolymers on styrene-butadiene basis.

Realization of the process according to the invention will be detailed by means of examples without intending to restrict.

12 Example 1

A mixture with a composition as detailed below was prepared in an internal 27-1S laboratory mixer of the type Werner-Pfleiderer, at 170 OC, revolution/minute n = 30; mixing was performed for 10 minutes. The mixture thus prepared was granulated, than on an injection moulding machine with a worm-gear driven piston specimen-plates were prepared for the tests.

Components of the mixture quantity a mass-% b mass-% Ethylene/vinyl acetate copolyme- Styrene-butadiene rubber Sulphur XXX N,W-Diphenyl-quanidine XXX Tetramethyl-thiuram20 - disulfide XXXX Dizumyl-peroxyde Antioxydant of quinoline type 60 2 1 0,2 1 60 1 1 X Evathane 2805 - ICI product vinyl-acetate content 28.5; crystalline proportion: 8 %; melt index MFI/ 19003 21.2 N/ = 5 dg/min 1 X X xXX xxXX xxxxx SzKSz - 30 ARKP/N Soviet product styrene content 30 % Mooney viscosity ML (1+4) at 100 Denax - Bulgarian Product Thiuram M - Monsanto product Flectol. H - Monsanto product 0 C = 42 Characteristics of the material with the aforementioned composition are summarized in t,' -e enclosed table. It is quite obvious that the sole material according to the example has a particularly low flowability, which results in easy processing. Resistance to oil and chemicals, so e.g. isooctane, paraffin cil and instrument oil is excellently good. I, such a manner it becomes possible to use the sole-r-,atE:--,a'L to working shoes.

Results of tests directed to resistance to ageing are better than average, which becomes obvious from the slight change in tensile strength and tensile elongation occurring under the influence of age-ing conditions. Similar conclusions can be drawn from the comparison of adhesion strength measured before and after ageing.

Linear shrinkage values of the sole material are also advantageous, which enables the production of form-soles with dimensional accuracy.

Results of resistance to abrasion and folding of the sole-material are surprisingly good. These 14 indices, as well as excellent results of gluing tests determining decisively processability represent determinaltive factors in respect to the application of the material in the shoe-industry. From the data of the table it becomes also obvious that changing of the vulcanization system (l/a - 1/b system) does not influence essentially the physical- mechanical indices.

ExamDle 2 A mixture with a composition as detailed below was prepared in an int ernal 2-1-S laboratcry 0 E the type Werner-Pfleiderer, at 160 l., mixer c. of revolutions of the rotor amounted 'LO 50 r.p.m. Mixing was performed for 8 minutes. From the granulated mixture thus obtained specimen-plates were prepared on an injection moulding machine with a worm-gear driven piston.

Components of the mixture a b mass-% mass-% Ethylene/vinyl acetat copolymer x 20 Polyethylene xx 20 Styrene-butadiene rubber xxx 60 Sulphur 2,2-dibenzene-thiazil-disulfide xxxx N,N'-diphenyl-quanidine xxxxx 3,3,6,6,9,9-hexamethyl-1,2,4,5-tetracyclononane Kaolin Instrument oil e 2 1.5 1.5 6 1? 8 X Evathane 2005 - ICI product crystalline ratio: 15 %, MFI 5 dg/min X X = Tippolen FA 2210 -Hungar-ian p-roduct crystalline ratio: 30 % MFI = 0.32 xxx = according to Example 1 xxXX = according to Example 1 xxxXX = according to Example 1 x MFI = melt index - 1 6 - Inspite of the high polyethylene content the advantages - as described in Example 1 appear here too. Excellent processability of the material (low flowability) is accompanied by a good resistance to oil and chemicals, when compared to traditionally prepared TR sole-materials with SBS basic polymer (mixture according to Example 6). Changing of the vulcanizing system (sulphuric, peroxydic) does not involve essential change in respect to the physical indices of the sole material.

Examnle 3 In a qui$--kmixer of the Farell-Bridge type 'ailed below was a m.4xture with a composition as det prepared (mixing parameters: mixing temperature, r.p.n,. of the rotor, mixing time: 6 minutes).

After having granulated the mixture specimen-plates were prepared on an injection-moulding machine with worm-gear driven piston.

Components of the mixture a mass-% b m ass - k Ethylene/ethyl acrylate copolymer X Maleized polyethylene xx Polypropylene xxx Styrene-butadiene rubber Sulphur N N '-dip hen y I -qu2riidine xxxxxx 1.5 Pclybutadiene rubber Xxxxx Tetramethyl-thiuram-disulfide xxxxxx Antioxydant of kaolin type xxxxxyx Natural zeolite Extraction oil xxXX 25 2 5 1.5 600 X X X XXX xxXX Lucobit - BASF product (Ethylene/lethyl-acrylate copolymer and bitumen in a 50-50 proportion) crystalline part: 6 MFI = 3 do/min polyethylene inoculated with 5 % maleic acid, crystalline ratio 22 %; MFI = 2.5 dg/min Tippolen K 823; MFI 0.1 dg/min; Hungarian product, product of TVK Solprene 303 -Phillips product Styrene content: 48 %; ML (1+4) at 100 0 C = 45 xxxxx xxxxxx = Plasticator 32 - GDR product, ML (1+4) at 100 0 C = 600 = according to Example 1 xxxxxxx = according to Example 1 From the data of the table enclosed it b ecomes obvious that inspite of the high filling ratio and high content of plasticizer (3/b mixture) this sole-material also shows the advantageous chara--terlis.1Lics, as emphasized in the specification, (outstanding resistance to oil and chemicals, good flowability, low tendency to shrinkage).

Example 4

A mixture with a composition as de',aJled be"low was prepared in an inner mixer of the type Commerio 0 the f 190 C, r.p.m. ol t (120 1) at a temperature ok rotor: n = 60; mixing was performed for 4 minutes. After having comminuted the mixture, plates were prepared on an injection-moulding machine provided with worm-gear driven piston.

19 - Components of the mixture Inoculated polypropylene x Ethylene/vinyl acetate copolymer xx Polystyrene xxx Styrene-butadiene rubber xxxx Natural rubber xxxxx Polyisoprene xxxxxx Surface treated sulphur Tetramethyl-thiuram-disulfide xxxxxxx Talcum instrument oil Phenolic antioxydant Pigment X xX xXX xXXX xxxXX xxxXxx xxxxxxx XXxXxxxx cuantity r m a S S - %) L 0 0.4 1 2 C.

1 1 xxxxxxXX polypropylene ino,culated with acrylic acid crystalline ratio: 52 %; MFI = 2.5 dg/min according to Example 1 PSZM 115 - Soviet product MFI = 8 dg/min according to Example 1 Smoked I. product of Malaysia ML(1+4) 100 OC = Cariflex IR - Shell product ML(1+4) 100 OC = 52 according to Example 1 according to Example 1 As it becomes obvious from the characteristics having been summarized in the table, the mixture according to Example 4 is also meeting the requirements according to the aim set.

Example 5

A mixture with a composition as detailed below was prepared in an inner laboratory mixer of the Werner-Pfleiderer type (2 1), with a r.p.m.

n = 80, at 150 a C, mixing was performed for 5 minutes.

After having granulated the mixture, specimenplates were prepared by injection moulding.

Components of the mixture Ethylene/vinyl acetate copolymer x Atactic polypropylene xx Styrene-butadiene rubber xxx Sulphur Tetramethyl-thiuram-disulfide xxxx N,N'-Diphenyl-quanidine xxxxx Antioxydant of quinoline type xxxxxx Dolomite Instrument oil Zinc-stearate slidint agent quantity 42 8 50.

0.2 2 1 5 1 1 21 - X X X X X X X xxxxx xxxxxx according to Example 1 Tipplen APP-A - Hungarian product, product cf TVK according to Example 1 according to Example 1 according to Example 1 according to Example 1 Physico-mechanical and chemical characteristics of the sole-material according to Example 5 - as sum- marrized in the table enclosed - verify the excellent applicability of the product in the shoe industry. Excellent resistance to oil, flowability, resistance to ageing, slight shrinkage are accompanied by slight abrasion, good foldability, high additional tensille strength and good gluing properties.

Number of example 1 2 3 (mixture for tested index a b a b a b comparison) Tensile strength (NImm 2) prior to ageing 7.9 7.0 7.2 6.8 6.7 6.6 6.8 7.2 (Hungarian Standard MSZ 490) 7.8 6.0 after ageing (MSZ 493) 7.2 7.4 6.5 6.5 5.6 5.8 6.4 6.0 Tensile elongatin (%) 550 prior to ageing (MSZ 4901) 500 490 450 470 350 340 360 400 after ageing (MSZ 493) 4BO 480 440 460 350 320 330 360 380 Additional tensile strength (N/mm) (MSZ 492) 5,6 56 50 50 48 43 52 53 25 Flexing resistence (up to 25 KO (MSZ 13571) 0 0 0 0 2 2 2 1 2 Abrasion resistance ( nj) 210 270 (MSZ 495) 180 150 170 190 200 210 180 linear shrinking (70 OC) 0.5 0.5 0.5 0.5 1.0 1.0 1.0 1.0 3.0 Flowability X (Nm) 7.5 7.3 6.4 8.3 12.5 12.3 11.0 6.0 14.5 i, 1 Number of example 1 2 3 4 5 6 tested index a b a b a b (mixture for comparison) Resistance to chemicals (% of loss) - isooctane (after 24 h) 8.0 7.9 7.5 7.2 5.0 5.2 5.5 6.0 8.5 - paraffin oil (measured after 1 week) 2.5 2.3 2.4 2.3 1.0 1.0 1.5 2.0 3.8 - instrumcnt oil (measured after 1 week) 4 4 3.6 3.6 2.5 2.3 3.0 3.4 5.5 Coefficient of friction - in a dry state 0.88 0.85 0.90 0.80 0.70 0.65 0.78 0.8 0.5 - in a wet state 0.70 0.70 0.65 0.70 0.55 0.52 0.68 0.6 0.44 Adhesion strength XX (N/mm) - prior to ageing 6.8 6.8 6.9 6.9 6.2 6.2 6.2 6.4 4.5 - after ageing 5.8 5.7 6.0 6.0 6.0 6.0 6.0 6.0 3 8 X = flowability was determined by following the change of Plasticity of the specimen having been subjected to a kneading effect in the mixing chamber of the rheclogic measuring instrument (Brabender-Plasti,Corder PLV-15). Tmper-ature of " durber: 170 'E, r.p.m. n = 45/ridn. In the Table the e4jilibriLfn irrirEnt values ebtaircd after 20 m. ki3aclirxj am gjvtrl. xx = The specimen was glued to upper leather, for this purpose a two-component polyurethane glue (VINICOLER-777 + 5 % Fixdur 6 H5rter) was used.

1 1 Example 6 (mixture for comparison) In order to be able to demonstrate advantageous features of the mixtures as presented in Examples 1 to 5, we prepared a thermoplastic rubber mixture on the basis of SBS block-copolymer with traditional. composition and mode of preparation. The mixture components corresponding to the composition as detailed below were mixed at 130 OC in a dry-mixer; thereafter the Mixture was homogenized in a screw-extruder and glranulated. Specimen-plates needed for the 'Les'.s were prepared in an injection moulding machine with worm-gear driven piston.

Components of the mixture Q u anti ty (mass-%) Styrene-butadiene-styrene-block- copolymer Polystyrene xX Ethylene/vinyl acetate copolymer xxx Silica xxxx Instrument oil Antioxydant of the quinoline type xxxxx X X xx xxx 20 20 10 5 1 = Solprene 1205 - Phillips Petroleum = according to Example 4 = according to Example 1 xxxx = Suparil - GOR product 1 Xxxxx = according to Example 1 Characteristics according to the table enclosed demonstrate it well, that flowability, resistance to oil, chemicals and ageing fall behind the similar characteristics according to Examples 1 to 5. From the point of view of application as sole material shrinkage and wear - being decisive in this respect - are also inferior to the similar indices o.L" the product having been produced accc.rd,..n-,' to the process, as recommended in the specification.

26 -

Claims

C 1 a i m S

Process for producing a thermoplastic solematerial - showing improved features, when compared to that made by using block-pblymers on styrene/butadiene basis - by applying 40- 60 mass-% thermoplastic poly olefine, 60 40 mass% diene rubber, 0 - 20 mass-% thermoplastic polystyrene and/or styrene copolymer, 0.1 - 600 mass-% plasticizer, filler, auxiliary mate- f rials, dyestuf.L, cross-linking agent known per se and other additives, by using one or more members thereof, comprising plasticizing as thermoplastic 4 lar pclyolefine polar inoculated polycle'Line, pc 1:1-olefiine copolymer, apolar polycle-fine, respectively the mixture thereof, having a melt index in the range 0between 0.1 and 30 dg/min, when measured at 190 C under a load of 21.2 N. , with a crystalline ratio abcve 5 mass-%, wherein relative proportion of polar:apolar olefines amounts to 1:1 the most; with a rubber on static styrene/butadiene and/or cZ-methyl-styrene/ butadiene copolymer basis serving as diene rubbar, wherein the content of styrene respectively styrene-derivative is maximally 10 - 50 mass-%, their Mooney viscosity lies in the range between 25 and 65 Mooney degree at 100 OC, measured with a rotor indicated with L, after the expiration of four minutes, in certain cases with other diene rubber, supposed that the proportion of SBR and other diene rubbers is 1:1 the most, by subjecting to shear and pressure at a-tem- perature above the softening point of the polyolefine having the highest softening point, in the presence of peroxydic or sulphuric cross-linking agents.
2. A process of producing a thermoplastic material suitable for molding into footwear soles, which process comprises mixing a styrene/butadiene rubber and/or an ()&-methyl styrene/butadiene rubber with a polyolefin and/or an Ot-olefin copolymer, which polyolefin or copolymer is at least partially crystalline and optionally may be inoculated, the mixing being conducted in the presence of a peroxide- or sulphur-based crosslinking agent and comprising subjecting the mixture to shear forces and pressure at a temperature above the softening point of the polyolefin or the &_-olefin copolymer or, where there are more than one such polymer present, above the softening point of the polyolefin/ CL-olefin copo2ymer having the highest SC.Lening point.
3. A process as claimed in claim 2, which comprises incorpcrating one or more further diene rubbers ani.lor ad,-i--1-ves into the mixture.
4. A thermoplastc material made Ity the process cf any one of claims 1 to 3.

5. A molded footwear sole made of the thermoplastic material claimed in claim 4.

-;z 7 - Amendments to the claims have been filed as follows 1. A process for producing a thermoplastic shoesole mater-Lal.

which comprises r...ix-Lng together:

(1) 40 to 60 parts by weight of one or more at least partially crystalline thermoplastic polyolefin, (!1) 40 to 60 parts by weight of one or more diene rubber, (111) 0 to 20 parts by weight of a thermoplastic polystyrene and/or styrene copolymer, together with 0.1 to 600 parts of a plasticiser, a filler, process- ing aids, dyestuff, cross-linking agent and other compounding additives, wherein:

(a) the thermoplastic polyolefin is a polar gra-fted lefin and/or a polar cy,'-olef n copolymer, polyol optionally together with one or more apclar polyclefins, the polyoLefln or mixture thereof having a melt the range of 0.1 to 30 dg/mA-n when measured index in 41 at lgk--,C under a load of 21.2 N, (t the diene rubber is a randomi styrene/butadiene ccpz-lymer and/or o- me'Lhyl stvrene/bil-ladiere copolymer, on--.'-ionally together with one or more other diene rubbers, the.ubber or mixture thereof having a Mooney v-scos--,-y L A ' -- A 'C n the range of 25 to 65 when measured at 1.00c and wherein the r.-ixng process involves su--,'--ctinp- the mix-lure to shear forces in the presence of a peroxide- and,'or a sulphur-based cross-linking agent at a temperature above the melttng point 25 of the polyolefin component (1).

2. A process according to claim 1, wherein the crystalline ratio of the polyolefin(s) (I) is at least 5 weight %.

-he rat 3. A process according to claim 1 or 2, wherein -11 lic, of pclar to apolar cop--r.en-ts of the 3C the range of (IC. to l):11 to 10.

_,27- 4. A process according to any one of cla-ms 1 to ---, wherein the polar polyolefin is a male-inated polyole-fin.
5. A process according to any one of claims 1 to 4, wherein as polar polyolefins ethylene/vinyl-acetate copolymer is used.
6. A process according to any one of claims 1 to 5, wherein the styrene content of the random styrene/butadiene rubber is in the range of from 10 to 50 weight %.
7. A process according to any one of claims 1 to 5, wherein I Llhe styrene content of the random Cv-' -methyl-styrene/butadd ene 10 copolymer rubber is in the range of from 10 to 50 weight 7,.
8. A process according to any one of claims 1 to 7, wherein natural rubber is used as one of the diene rubbers.
9. A process according to any one of claims 1 to 8, wherein polvbutadiene is used as one of the diene rubbers.
10. A process according to any one of claims 1 to 9, wherein a modified d'ene rubber is used as one of the diene rubbers.
11. A process according to clair., 10, wherein the mod.J."-'--d diene rubber is a carboxv-iated d.4ene rubber.
12. A process accordinp- to clair. 10, wherein the modified A. J diene rubber is a epoxydized natural rubber.
13. A process according to any one of claims 1 to 12, wherein the sulfur cross-linking agent is a sulfu.--donor system.
14. A process according to claim 13, where-in the sulfur-j2.nDr .e-. is 4-etra,-,ethvl-thLuram-disu-fide.

sys'. 1 - o -
15. A process accord-ng to any one of c.'a.,-.s 1 te IZ, comprising either batchwise O.r continuous production of --he thermoplastic shoescle material.
16. A process as claimed in any one of claims 1 to 11-, which includes the further step of making the footwear sole material into footwear soles.
17. A thermoplastic material made by the process of any one of claims 1 to 15.

1 L 8. A moulded fool-wear sole made of the thermotlastic material claimed in claim 17.

Published 1989 atThe Patent=ce,Stste House, 5671 High Holborn, London WCIR4TP. Further copies maybe obtEdned from The PatentOMce. EWLIes Branch, St Mary Cray, Orpington- Kent BRS 3RD. Printed by Multiplex techniques R4 St Mary Cray. Kent, Con- 1/87