SYNTHETIC RUBBER COMPOSITION

Abstract: A polymeric composition comprising a synthetic styrene-butadiene rubber copolymer or a mixture of two or more synthetic styrene-butadiene rubber copolymers having a butadiene content in the range of 50 to 90% by weight and a styrene content in the range from 10 to 50% based on the total weight of the styrene-butadiene copolymer or mixture of copolymers, the copolymer or mixture of copolymers being suitable for use as a synthetic rubber elastic band.

Description: SYNTHETIC RUBBER COMPOSITION The present invention relates to a polymeric composition, more particularly to a synthetic rubber composition. A further aspect relates to plastic bands, particularly elastic bands made from the synthetic rubber polymeric compositions. One particular application of the present invention is in connection with a material suitable for use in compounding a synthetic rubber band for use as a replacement for natural rubber bands, and it will be convenient to describe the invention with reference to this particular application. It is to be understood however, that reference to the particular application is not to be considered as a limitation to the scope of the present invention as it will be apparent that the material could be used for other applications. It is to be noted that the term "elastic bands" as used in this specification means bands having the ability of a material to quickly recover their approximate original dimensions after removal of a load that has caused deformation. Hence "elastic bands" can be stretched or elongated by the application of a load, however they will return to their approximate original dimension on removal of the load. Elastic bands generally known as rubber bands have usually, been made from natural rubber. Although attempts have been made to use synthetic rubbers, such attempts have generally not been found to be satisfactory because of limitations to the desirable characteristics and performance of the bands such as poor weatherability, a tendency to neck during stretch, a tendency to stick together, low ultra-violet stability even with the use of an ultra-violet absorber, a non-rubber-like feel, and the like. On world wide markets, in order that synthetic elastic bands could be used as replacements for natural rubber bands which had previously been cross-linked (vulcanised) to obtain their desired end use properties it was necessary to carefully select the particular types and amounts of copolymers to give the desired properties. Some of the considerations when deciding on the particular type of polymeric material to be used in selecting the polymeric compositions suitable for use to make elastic bands in accordance with the present invention include the following: 1. The synthetic rubber elastic bands should possess a rubber-like feel similar to the feel of natural rubber bands 2. The physical properties such as ultimate tensile strength, elongation and the like, which properties will be described in more detail OMPI later, of the natural rubber band should at least be equalled, and preferably be exceeded, by the corresponding elastic bands made in accordance with the present invention 3. The synthetic elastic bands should be capable of being processed on relatively standardised equipment which is suitable for processing conventional thermoplastic materials thus, dispensing with the need to provide specialised processing equipment which is required when processing natural rubber bands. Some of the synthetic polymeric and copolymeric materials thought to be of use in synthetic elastic bands such as thermoplastic polyurethane elastomers, polyolefin thermoplastic elastomers were rejected on theoretical grounds since they were considered not to have all of the properties required from a review of their known properties. After experimentation and testing by the present applicants, it was found that styrene-butadiene copolymers, particularly styrene-butadiene-styrene rubber block copolymers and combinations of two or more such materials produced elastic bands which had acceptable properties and which could be favourably compared to natural rubber bands. Further, it was discovered by the applicants that two or more copolymers could be mechanically blended together to produce a new composite material that exhibited acceptable properties and which could be further processed on processing equipment suitable for processing non-cross-linked thermoplastic material since the cross-linking of the polymeric material was not required. Thus, the copolymeric materials of the present invention could be manufactured and processed simply like a thermoplastic material analagous to a natural rubber when moulded. It is an object of the present invention to provide a polymeric composition, more particularly, a synthetic rubber polymeric composition which is suitable for use in an elastic band as a replacement for natural rubber, and which alleviates at least some of the problems of previous attempts to provide a synthetic rubber. It is a further object of the present invention to provide an elastic band made from a synthetic rubber composition which is suitable as a replacement for a natural rubber band. According to the present invention there is provided a polymeric composition comprising a synthetic styrene-butadiene rubber copolymer or a mixture of two or more synthetic styrene-butadiene rubber copolymers having a butadiene content in the range 50 to 90% by wt and a styrene content in the range from 10 to 50% based on the total weight of the styrene-butadiene copolymer or mixture of copolymers, the copolymer or mixtures of copolymers being suitable for use in a synthetic rubber elastic band. According to a further aspect of the present invention there is provided an elastic band made from a synthetic rubber composition comprising a synthetic styrene-butadiene rubber copolymer or a mixture of synthetic styrene-butadiene copolymers having a butadiene content in the range from 50 to 90% and a Olv-T styrene content in the range from 10 to 50%, based on the weight of the copolymer or copolymers. According to a further aspect of the present invention there is provided a process for producing a synthetic rubber band comprising the steps of (1) mixing the or each polymeric composition to form a homogeneous mixture (2) heating the mixture to a first temperature (3) agitating the mixture at the first temperature (4) heating the mixture to a second temperature (5) extruding the mixture in a tube-like configuration (6) forming individual bands from the tube-like con iguration. The or each styrene-butadiene rubber copolymer may be non-oil extended or oil extended. However, if a non-oil extended rubber copolymer is used it is necessary that an extending oil such as paraffinic/ napthenic oil blend or the like be used in conjunction with the copolymer. Preferably, the extending oil is used in an amount of 0 - 150%, more preferably 0 - 100%, and even more preferably 0 - 60% by weight based on the weight of the non-oil extended synthetic rubber used. Preferably, the synthetic copolymer is a block copolymer. Preferably the copolymeric material is Styrene - Butadiene - Styrene (SBS) block polymeric material and the extender may be a paraffinic/napthenic extender. The copolymeric material may comprise SBS materials of different molecular weights combined together. OMFI The elastic band made in accordance with the present invention may be either opaque or translucent. Basically, the composition comprises a synthetic copolymeric material with additives and/or modifiers and having properties which satisfy the following minimum requirements. ultimate Tensile Strength (U.T.S.) (MPa) 3.0 Elongation at Break 700% 100% Modulus (MPa) 0.2 300% Modulus (MPa) 0.5 Tensile Set (at 600% elongation) (%) 15% Shore A hardness (10 sec delay) 18 to 90 A more preferred set of minimum requirements properties is as follows: Ultimate Tensile Strength (MPa) 8 . 5 Elongation at Break 1100% 100% Modulus (MPa) 0 . 6 - 1 .0 300% Modulus (MPa) 0 . 9 - 1. 6 Tensile Set (at 600% elongation) {%) 10% Shore A Hardness (10 sec delay) 51 59 'Tensile strength, breaking force, ultimate elongation shall be determined as described in Method B of ASTM D412' One preferred composition which has achieved at least the first mentioned range of properties comprises a block copolymeric material with an average 3 molecular weight within the range 200 x 10 to 350 x 103 and an oil extender compri 7 sing 15% to 50% by weight of the total composition. A preferred synthetic copolymer used in the present invention is Solprene 411 which is a styrene-butadiene block copolymer having a Butadiene:Styrene ' ratio of 70:30. A further preferred synthetic copolymer used in the present invention is Solprene 475 which is a styrene-butadiene block copolymer having a Butadiene:Styrene ratio of 60:40 having 50% oil content. Solprene 411 and Solprene 475 are both supplied by Phillips Chemical Co. The extender is preferably a paraffinic/napthenic oil extender such as FLEXON 765 or PROREX 131. The composition may include further additives or modifiers tc provide varying properties. Such additives or modifiers may include U.V. absorbers, pigments, anti-oxidants, release agents, anti-tack agents, external lubricants, drying agents or the like. For example, to modify the general physical properties of the composition, modifiers such as NIPPOFLEX EVA and/or HYCAR Nitrile rubber may be used. A preferred external lubricant is Zinc Stearate and/or WAX OP. A typical anti-oxidant which may be used is IRGANOX 1010 or PS800. An anti-tack agent found to be desirable is CRODAMIDE E.R. Drying agents such as ULTRASIL VN3 may be used and a preferred U.V. absorber is TINUVIN 327. It has been found particularly desirable that the copolymeric material be formed from a combination of any of the following; SOLPRENE 475, SOLPRENE 411, SOLPRENE 1205 or SOLPRENE 406. In order to obtain increased hardness, resilience or tensile strength properties Solprene 411 may be used in preference to the other synthetic rubbers. The following raw materials in amounts falling within the indicated ranges may be used to produce an opaque synthetic rubber band which has properties similar to a natural rubber band. pph based on Styrene-butadiene-styrene rubber - oil extended 0 - 100 Styrene-butadiene-styrene rubber - *+ non-oil extended 0 - 100 Oil Extender 0 - 150 + Amide (anti-tack agent) 0 - 3.0 (hydrated) Silica (drying agent) 0 - 40 Metal Stearate (lubricant) 0 - 4.0 Nickel di-butyl di Thiocarbonate (anti-oxidant) 0 - 10.0 Ouiniline (anti-oxidant) 0 - 10.0 Ester (lubricant) 0 - 4.0 hydrocarbon wax (lubricant and anti-oxidant) 0 - 10.0 the amounts indicated are in inverse proportion to one another to achieve a total weight of 100 pph of SBSR. If non oil extended SBSR is used the amount of Oil Extender is in direct proportion to the amount of non-oil extended SBSR used. Preferably the following raw materials in the following amounts may be used to produce a clear or translucent synthetic rubber band. pph based on Styrene-Butadiene-Styrene Rubber * (oil extended) 0 - 100 Styrene-Butadiene-Styrene Rubber *+ (non-oil extended) 0 - 100 Oil Extender 0 - 150 + Benztriazole (U.V. absorber) 0 - 2.5 Amide (Anti-tack agent) 0 - 3.0 (hydrated) Silica (drying agent) 0 - 40.0 (hindered) Poly-phenol (anti-oxidant) ) 0 - 2.5 ) Di Lauryl Thio Di Pro ionate (anti-oxidant) 0 - 2.5 Metal Stearate (lubricant) 0 - 4.0 Total of either type of SBSR to be 100 parts in inverse proportion to each other. The amount of oil extender used is in direct proportion to amount of non-oil extended SBSR. Either or both anti-oxidants may be used. The following pigments may be used in the manufacture of opaque bands; Titanium Dioxide, Furnace carbon black, or the like. The following pigments may be used in the manufacture of clear or translucent bands; Aluminium sulfasilicate, Unstabilised alpha phthalocyanine, organic resin particles containing fluorescent dyes in solid solution suspended within a polyamide resin system, or the like. O Other conventional pigments such as chrome, lead pigments, or the like may be used in either opaque or clear translucent bands. A preferred example of pigments for opaque bands is cadmium red together with a combination of lead chromate, lead molybdate and lead sulphate. The addition levels of the pigment in the synthetic rubber band are such so as not to detract from the performance of the synthetic rubber bands or the physical properties possessed by the band. Typical and broad addition levels of various pigments are indicated in the following table. It is to be noted that the maximum pigment level is about 40 pph of pigment based on 100 parts of copolymer. PIGMENTS TRANSLUCENT BANDS Pigment Colour Broad Addition Typical A (max) Leve ULTRAMARINE BLUE RS9 13.5 1.35 GRAPHTOL BLUE A BLP BLUE .5 .05 SIGNAL GREEN Z 8 GREEN 9.5 .95 ARC YELLOW S-16 ORANGE 12.0 1.20 AURORA PINK S-ll 8.0 .80 ULTRAMARINE BLUE RS9 PURPLE 3.0 .30 NEON RED ZN2 5.8 .58 TIOXIDE RCR/6 RED 0.1 .01 AURORA PINK S-ll 8.0 .80 ARC-YELLOW S-16 RED 0.5 .05 LUNAR YELLOW ZN-27 YELLOW 10.0 1.00 OPAQUE BANDS TIOXIDE RCR/6 WHITE 38.0 3.80 ACARB 300 BEADS BLACK 20.0 2.00 CADMIUM RED LR 1506 20.0 2.00 PERM, ORANGE L100 RED 7.0 0.70 Suitable additives used in the manufacture and processing of the elastic bands made in accordance with the present invention include the following: (a) OIL EXTENDERS Flexon 765 marketed by Esso; Shellflex 451 marketed by Shell; Dionna PN55 marketed by Phillips; and, Process oil P160 marketed by British Petroleum. (b) ANTI-TACK AGENTS Slip Quick marketed by Croda; and Unislip 4407 marketed by Unilever. (c) U.V. ABSORBERS Tinuvin P and Tinuvin 327 marketed by Ciba-Geigy; U/R marketed by Shipuro Ltd; and UV531 marketed by Cyasorb. (d) LUBRICANTS Stearic Acid marketed by Steetley; PA 520 marketed by Hoechst; and Advawax 240 marketed by Kemrez. (e) ANTIOXIDANTS Agerite G.T. marketed by Vanderbilt; Ionox 330 marketed by Shell; D.L.T.D.P. and Robac ZBuD marketed by Robinson Bros.; Agerite Resin D marketed by Vanderbilt; and Irganox 565 marketed by Ciba-Geigy. (f) ANTIOZONANTS Santowhite TBTU marketed by Monsanto; Ozone Protector 80 marketed by Reighhold Chemicals Ltd.; and Sunproof Wax marketed by Mobile. In manufacturing the synthetic rubber elastic bands of the present invention conventional processing equipment may be used. A similar process is used in the manufacture of clear translucent bands as is used in the manufacture of opaque bands. The process of the present invention is simplified when compared to the processing necessary for natural rubber which O FI gives rise to a great advantage of the present invention. Generally, the process of the present invention comprises adding the selected SBS rubber or rubbers to a conventional mixer. Whilst mixing the mixture of SBS rubbers, raise the temperature to a first temperature. Once this temperature has been obtained, slowly add the oil to the mixture. If only oil extended rubbers have been used in the selected mixture, the addition of oil is not necessary. Suitable additives such as the stabilizers, lubricants and pigments are then added to the mixture. The mixture is then mixed at a high speed whilst the temperature is raised to the a second temperature. When the mixture has been raised to this desired temperature, the silica acting as a drying agent is added. Continued high speed mixing is maintained whilst the temperature is further raised. After the mixing is completed the batch is removed from the mixer, ready for further processing into rubber bands. The mixture is further processed by adding the mixture to a conventional extrusion machine. The mixture is extruded in a tube-like configuration, ready for chopping into individual bands. The invention will now be described with reference to the following examples of compositions falling within the scope of the invention. EXAMPLE 1 The rubber bands were produced from a composition having the following formulation: OM y VI PHR (Parts per Hundred Resin) Solprene 475 including the oil extender 75 Solprene 411 50 Ultraεil VN3 1.0 Flexon 765 12.5 Zinc St. 0.7 Crodamide ER 0.5 Irganox 1010 0.15 Irganox PS800 0.15 The following properties are exhibited: Shore A 55 U.T.S. (MPa) 17.5 100% Modulus (MPa) 1.2 300% Modulus (MPa) 1.5 Tear Resistance (N/mm.) 30.4 Tensile Set (%) 12 Elongation (%) 1160 EXAMPLE 2 To improve the U.V. stability of the product of Example 1 the composition was altered as follows: y H " PHR (Parts per Hundred Resin) Solprene 475 75 Solprene 411 50 Ultrasil VN3 1.0 Prorex 131 14 Zinz. St. 0.7 Crodamide ER 0.5 Irganox 1010 0.5 Irganox PS800 0.5 Tinuvin 327 0.8 EXAMPLE 3 Solprene 475 122 Solprene 1205 19 Flexon 765 2.0 Nippoflex 631 9.0 Irganox 1010 0.3 Irganox PS800 0.3 Zinc St. 0.5 This product exhibited the following properties: U.T.S. (MPa) 9.5 100% Modulus (MPa) 1.1 300% Modulus (MPa) 1.8 Elongation (%) 1000 Shore A 55 Tensile Set % 14 S.G. 0.95 EXAMPLE 4 Rubber bands were produced using a composition of the following formulation: PHR (Parts per Hundred Resin) Solprene 475 60 Solprene 411 60 Prorex 131 15 Ultrasil VN3 0.5 Irganox 1010 0.5 Irganox PS800 0.5 Croda ide ER 0.25 Zinc St. 0.5 Tinuvin 327 1.2 This product exhibited the following properties: Elongation (%) 1828 100% Modulus (MPa) 0.97 300% xModulus (MPa) 1.35 U.T.S. (MPa) 8.98 Shore A 55 Necking slight Tensile Set (%) 15 EXAMPLE 5 Formulation phr Solprene 411 100 Prorex 131 100 Irganox 1010 0.5 Irganox PS800 0.5 Tinuvin 327 1.2 Ultrasil VN3 0.5 Zinc St. 0.7 Crodamide ER 0.25 This product exhibited the following properties OMPI Shore A (10 sec. delay) 18 Ultimate Tensile Strength (MPa) 3.0 100% Modulus (MPa) 0.20 300% Modulus (MPa) 0.50 Elongation (at break) (%) 1160 EXAMPLE 6 phr Solprene 475 122 Zinc St. 0.5 Irganox 1010 0.3 Irganox PS800 0.3 Hycar 1442X110 19 This product exhibited the following properties: U.T.S. (MPa) 8.9 100% Modulus (MPa) 0.95 300% Modulus (MPa) 1.80 Elongation (%) 898 Tensile Set (%) 20 S.G. 0.975 Shore A (10 sec. delay) 60 PROCESSING In the event that two or more polymeric raw materials are used in the formulation to make an elastic band, it is necessary that the polymeric materials be uniformly blended to produce a homogeneous mixture prior to further processing. If this is the case, the following process occurs which will be described with reference to a WERNER and PFLEIDERER KP800 processing line. Although the OM WI processing will be described with particular reference to this processing line, any suitable processing line for use with thermoplastic materials may be used. Typical operating conditions herein specified relate only to the WERNER and PFLEIDERER KP800 processing line and may be altered to suit the specific processing line used. The raw materials are weighed and then mixed in a high-speed mixer (Fielder mixer) to a pre-set temperature, the material is then fed into a twin screw extruder (ZDS-K) that in turn feeds a single screw extruder (ESA) with a spaghetti die attachment, the material is cut at the die face, cooled and then bagged. MIXING & COMPOUNDING CONDITIONS 1. Add both rubbers to mixer, mix to 30°C 2. Add oil slowly (low speed mix) 3. Add stabilizers, lubricants and pigments 4. Allow to mix at high speed to 45°C to 50°C 5. Add silica at 45°C to 50°C 6. High speed mix to 50°C to 65°C 7. Drop batch at 50°C to 65°C TWIN-SCREW (ZDS-K) Rpm of crammer: 20 - 22 Screw No. (type) : 5 or 13 Rpm of screws: 175 - 250 Drive: 42 - 65.0 KW Torque: 84% - 88% Cooling: 64/74°C - 60/90°C SINGLE SCREW (ESA) Rpm of screw: 38 - A6 Drive: 9.0 - 17 KW Torque: 17 - 28% Cooling: 60/40 - 100°C CUTTER No. of knives: 2 Setting: 4.5 9.5 Oil pressure: 6.7 7.4 Oil temperature: 24°C 32°C TEMPERATURE SETTINGS (Twin screw) (ZDS-K) Zone: 1 2 3 Stock Temp. Set (°C) 120 120 120 140 - 185°C •145 -145 -145 (Single screw) (ES-A) Zone: 4 5 6 Set (°C) 100 100 130 160 - 170°C ■140 -140 -145 Once the raw material i.e. the polymeric composition, together with any additives have been hoir.ogeneously blended by the above described process, the mixture so produced is extruded. A typical extrusion run will be described, but it is to be noted that all above machine conditions will vary each production run due to variations in raw material quality and ambient temperature. EXTRUSION TYPE - 2^" SINGLE SCREW Screens : 1x20 , 1x40 , 1x60 , 1x100 Otø TEMPERATURE SETTINGS Zone: 1 2 3 4 £ Head 1 Head 2 °C: 80 80 90 90 90 100 100 Rpm and dies will vary according to the size of the tube required. In compounding the formulation any equipment used for mixing plasticiεed PVC can be used e.g. Banbury, Henschel or Buzz-ko-kneader. The material can even be dry blended and fed straight into an extruder. The extruders can either be twin or single screw configuration, including screws using mixing pins, maddock heads etc. The described synthetic rubber band has a number of advantages including: (1) Recent studies indicate that synthetic rubber bands alleviate the condition of dermatitis amongst some people who handle natural rubber bands. The bands made in accordance with the present invention contain no natural rubber, and other attendant natural substances causing dermatitis, and thus, are not as conducive to causing dermatitis. (2) Natural rubber bands necessarily are powdered in order to prevent them from sticking together. Since the synthetic rubber bands of the present invention are fully formulated, there is no requirement that they be powdered. (3) The synthetic rubber bands of the present invention may be coloured with bright or fluorescent colours which enhances their sales appeal, may be used in colour coding systems or classifications, as fashion accessories. (4) Synthetic rubber bands do not grab the wearer's hair when used as a styling aid in hair fashion. (5) Physical or chemical properties of plastic bands are enhanced over corresponding properties of natural rubber bands such as continuous processing is possible rather than being limited to batch processing, more consistent properties are obtainable with are reproducible whereas natural rubber bands vary in accordance with natural variations of the natural rubber, synthetic bands are lighter than natural bands which means reducing postage rates, more for weight. The described arrangement has been advanced merely by way of explanation and many modifications may be made thereto without departing from the spirit and scope of the invention as defined in and appended claims.

Claims: CLAIMS : 1. A polymeric composition comprising a synthetic styrene-butadiene rubber copolymer or a mixture of two or more synthetic styrene-butadiene rubber copolymers having a butadiene content in the range 50 to 90% by weight and a styrene content in the range from 10 to 50% based on the total weight of the styrene-butadiene copolymer or mixture of copolymers, the copolymer or mixture of copolymers being suitable for use as a synthetic rubber elastic band. 2. A polymeric composition band comprising a synthetic styrene-butadiene rubber copolymer or a mixture of synthetic styrene-butadiene copolymers having a butadiene content in the range from 50 to 90% and a styrene content in the range from 10 to 50%, based on the weight of the copolymer or copolymers, incorporated into a synthetic rubber band. 3. The composition of claim 1 or claim 2 wherein at least one of the copolymeric material is non-oi1—extended. 4. The composition of claim 1 or claim 2 wherein at least one of the copolymeric material is oil-extended. 5. The composition of claim 4 in which the oil-extender is a paraffinic/napthenic oil blend. _OM 6. The composition of claim 4 or 5 in which the oil is 0 - 150% by weight based on the weight of non-oil extended polymeric material. 7. The composition of any one of claims 1 to 6 in which the polymeric material is a block copolymer. 8. A composition according to any one of claims 1 to 7 further comprising pigments in an amount from up to about 40 pph based upon 100 parts of copolymer. 9. A composition according to claim 8 in which the pigment when incorporated into the composition is suitable for producing an opaque synthetic rubber band. 10. A composition according to claim 8 in which the pigment when incorporated into the composition is suitable for producing a clear translucent band or a fluorescent band provided the composition is clear or translucent. 11. A composition according to any one of the preceding claims further comprising one or more of the following modifiers, additives or the like which are anti-tack agents, ultra-violet absorbers, lubricants, antioxidants and antiozonants. 12. A synthetic rubber band comprising a synthetic styrene-butadiene rubber copolymer or a mixture of synthetic styrene-butadiene copolymers having a butadiene content in the range from 50 to 90% and a styrene content in the range from 10 to 50%, based on the weight of the copolymer or copolymers. 13. The rubber band of claim 12 which is either clear or opaque. 14. A rubber band of claim 12 or 13 having the following properties: Ultimate Tensile Strength (MPa) 3.0 Elongation at Break 700% 100% Modulus (MPa) 0.2 300% Modulus (MPa) 0.5 Tensile Set (at 600% elongation) (%) 15% Shore A hardness (10 sec delay) 18 15. A rubber band of claim 12, or 13 having the following properties: Ultimate Tensile Strength {MPa) 8 . 5 Elongation at Break 1100% 100% Modulus (MPa) 0 . 6 - 1 .0 300% Modulus (MPa) 0 . 9 - 1 . 6 Tensile Set (at 600% elongation) (%) 10% Shore A Hardness (10 sec delay) 51 59 16. A process for producing a synthetic rubber band comprising the steps of (1) mixing the or each polymeric composition to form a homogeneous mixture (2) heating the mixture to a first temperature (3) agitating the mixture at the first temperature (4) heating the mixture to a second temperature (5) extruding the mixture in a tube-like configuration (6) forming individual bands from the tube-like configuration. 17. A process according to claim 16 further comprising adding any modifier or additive to the mixture. 18. A process according to claim 16 or 17 wherein the first temperature is 30°C, and the second temperature is between 30°C and 65°C. 19. A process according to any one of claims 16 to 18 further comprising a high speed mixing step which raises the second temperature to about 55°C. 20. A process according to claim 19 in which the high speed mixing step is performed prior to extruding the mixture. 21. A synthetic rubber band substantially as hereinbefore described with reference to the accompanying examples. 22. A clear or translucent synthetic rubber band substantially as hereinbefore described with reference to the accompanying examples. 23. An opaque synthetic rubber band substantially as hereinbefore described with reference to the accompanying examples. 24. A fluorescent synthetic rubber band substantially as hereinbefore described with reference to the accompanying examples. 25. A polymeric composition substantially as hereinbefore described with reference to the accompanying examples. 26. A process for producing a synthetic rubber band substantially as hereinbefore described with reference to the accompanying examples. 0..--PI

Inventors: MOLE CAMERON ASHLEY, STOREY GARY JOHN, MOLE, CAMERON, ASHLEY, STOREY, GARY, JOHN
Applicants: NYLEX CORP LTD, NYLEX CORPORATION LIMITED
Application year: 1982
Main classification: C08J5
IPC codes: B29C47, B29D29, C08L9