Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D29/00—Producing belts or bands
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L9/00—Compositions of homopolymers or copolymers of conjugated diene hydrocarbons
  • C08L9/06—Copolymers with styrene
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/001—Combinations of extrusion moulding with other shaping operations
  • B29C48/0018—Combinations of extrusion moulding with other shaping operations combined with shaping by orienting, stretching or shrinking, e.g. film blowing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
  • B29C48/07—Flat, e.g. panels
  • B29C48/08—Flat, e.g. panels flexible, e.g. films
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
  • B29C48/09—Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels
  • B29C48/10—Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels flexible, e.g. blown foils
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/01—Use of inorganic substances as compounding ingredients characterized by their specific function
  • C08K3/013—Fillers, pigments or reinforcing additives
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/0008—Organic ingredients according to more than one of the "one dot" groups of C08K5/01 - C08K5/59
  • C08K5/005—Stabilisers against oxidation, heat, light, ozone
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/01—Hydrocarbons

Definitions

• 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.
• 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.
• the synthetic rubber elastic bands should possess a rubber-like feel similar to the feel of natural rubber bands
• 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.
• thermoplastic polyurethane elastomers 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• the synthetic copolymer is a block copolymer.
• the copolymeric material is Styrene - Butadiene - Styrene (SBS) block polymeric material and the extender may be a paraffinic/napthenic extender.
• SBS Styrene - Butadiene - Styrene
• the copolymeric material may comprise SBS materials of different molecular weights combined together.
• the elastic band made in accordance with the present invention may be either opaque or translucent.
• the composition comprises a synthetic copolymeric material with additives and/or modifiers and having properties which satisfy the following minimum requirements.
• a more preferred set of minimum requirements properties is as follows:
• One preferred composition which has achieved at least the first mentioned range of properties comprises a block copolymeric material with an average
• a preferred synthetic copolymer used in the present invention is Solprene 411 which is a styrene-butadiene block copolymer having a
• 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.
• additives or modifiers may include U.V. absorbers, pigments, anti-oxidants, release agents, anti-tack agents, external lubricants, drying agents or the like.
• 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 411 may be used in preference to the other synthetic rubbers.
• Oil Extender is in direct proportion to the amount of non-oil extended SBSR used.
• the following raw materials in the following amounts may be used to produce a clear or translucent synthetic rubber band.
• 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.
• 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.
• 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
• Tinuvin P and Tinuvin 327 marketed by Ciba-Geigy; U/R marketed by Shipuro Ltd; and UV531 marketed by Cyasorb.
• 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.
• 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.
• 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
• This product exhibited the following properties:
• Rubber bands were produced using a composition of the following formulation:
• This product exhibited the following properties:
• Irganox 1010 0.5 Irganox PS800 0.5
• This product exhibited the following properties
• 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.
• a high-speed mixer Fielder mixer
• ZDS-K twin screw extruder
• ESA single screw extruder
• Zone 1 2 3 Stock Temp. Set (°C) 120 120 120 140 - 185°C
• 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.
• 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.
• any equipment used for mixing plastici ⁇ ed 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 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.
• Synthetic rubber bands do not grab the wearer's hair when used as a styling aid in hair fashion.
• 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.

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Compositions Of Macromolecular Compounds (AREA)

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Family Cites Families (9)

• 1982
  • 1982-11-30 EP EP82903438A patent/EP0095466A1/de not_active Withdrawn
  • 1982-11-30 WO PCT/AU1982/000202 patent/WO1983001955A1/en unknown

Non-Patent Citations (1)

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