Classifications

• • 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
  • B29C48/022—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the choice of material
• • 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
  • B29C48/25—Component parts, details or accessories; Auxiliary operations
  • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
  • B29C48/395—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die using screws surrounded by a cooperating barrel, e.g. single screw extruders
  • B29C48/40—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die using screws surrounded by a cooperating barrel, e.g. single screw extruders using two or more parallel screws or at least two parallel non-intermeshing screws, e.g. twin screw extruders
  • B29C48/405—Intermeshing co-rotating screws
• • 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
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2021/00—Use of unspecified rubbers as moulding material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
  • B29K2105/0005—Condition, form or state of moulded material or of the material to be shaped containing compounding ingredients

Definitions

• a method for the continuous production of a composition comprising rubber, hydrocarbon resin and solvent
• the present invention relates to a method for the production of a composition comprising rubber, hydrocarbon resin and solvent, in particular, an adhesive formulation.
• compositions are produced in dissolving apparatus in which the various ingredients are added by a "batch” method and are left in contact until the solvent has dissolved the rubber and the hydrocarbon resin as well as any additives that are present.
• this method does not ensure uniformity of the properties of the various production batches of a given composition.
• the subject of the present invention is a method for the continuous production of a composition of the type indicated above, with the use of a dual-screw extruder.
• control systems with which an extruder is typically provided ensure that the process parameters - such as, for example, the time spent in the extruder, the amount of energy supplied per unit of product, the number of revolutions of the screws per unit of time, the thermal profile, and the like - which influence these properties, are maintained over time.
• a dual-screw extruder preferably of the co-rotating type, enables effective mixing of the various components of the composition to be achieved, also allowing the solvent content of the composition to be reduced, typically from values of about 65% to values of about 45-50%. This reduction is particularly significant in view of the fact that the recovery of the solvent from the final composition involves considerable costs and that a certain quantity of solvent - proportional to that which is present initially - is in any case dispersed to the exterior, resulting in environmental and economic damage.
• the method of the invention preferably provides for the addition of at least one fraction of the solvent at a point of the extruder that is downstream of its initial section. Even more preferably, the solvent is added at a plurality of different points disposed downstream of the initial section of the extruder.
• the first addition of solvent may take place at a distance of at least 4 D (where D denotes the diameter of one of the two extruder screws) , for example, 20 D, from the initial section of the extruder.
• the temperature is kept within a range of between 60°C and 120°C whereas, in the portion of the extruder that is downstream of the point at which the first addition of solvent is performed, the temperature is kept within a range of between 40°C and 80°C, the temperature in the upstream portion being greater than that prevailing in the downstream portion.
• the rubber used may be selected from the group consisting of natural rubbers, synthetic rubbers, and mixtures thereof, for example, styrene-isoprene-styrene (SIS) , styrene- butadiene-styrene (SBS) , and natural rubber (NR) .
• SIS styrene-isoprene-styrene
• SBS styrene- butadiene-styrene
• NR natural rubber
• a hydrocarbon resin is a resin prepared by the polymerization of unsaturated constituents of coal tar, rosin, or petroleum. Hydrocarbons having tackifying properties, for example, of the type marketed under the name Escorez or Wing-tack, and mixtures thereof are preferably used.
• the solvent is selected, for example, from the group consisting of hexane, pentane, dichloropropane, and mixtures thereof .
• Figure 1 shows schematically a dual-screw extruder in which a method according to the invention is implemented
• FIGS 2 and 3 show schematically respective dual- screw extruders in which further embodiments of the method of the invention are implemented.
• a method for the continuous production of a composition comprising rubber, hydrocarbon resin, and solvent provides for the use (Figure 1) of a dual-screw extruder 10, for example, of the co-rotating type.
• a first section 12, a second section 14, a third section 16, and a fourth section 18, arranged in succession, are distinguished in the extruder 10.
• the first section 12 has a length equal to 16 D (where D denotes the diameter of one of the two screws of the extruder 10)
• the second section 14 has a length equal to about 12 D
• the third section 16 has a length equal to about 12 D
• the fourth section 18 has a length equal to about 16 D.
• Rubber 20, hydrocarbon resin 22, as well as conventional additives 24, for example, oxidising agents are introduced at the beginning of the first section 12.
• the temperature of the first section 12 is kept between 60 and 120°C. Homogenization of the ingredients introduced takes place in the first section 12.
• a fraction of between 5 and 20% of the total solvent 26 is introduced at the beginning of the second section 14.
• the temperature of the second section 14 is kept between 30 and 80°C. Dissolving of the rest of the ingredients in the solvent 26 takes place in the second section 14.
• a further fraction of between 5 and 20% of the total solvent 26 is introduced at the beginning of the third section 16.
• the temperature of the third section 16 is kept between 20 and 60°C. Further dissolving of the rest of the ingredients in the solvent 26 takes place in the third section 16.
• a variant of the production method of the invention is described with reference to Figure 2.
• a first section 12, a second section 14, a third section 16, a fourth section 18, and a fifth section 28, arranged in succession, are distinguished in the extruder 10.
• the first section 12 has a length of about 12 D
• the second section 14 has a length of about 8 D
• the third section 16 has a length of about 12 D
• the fourth section 18 has a length of about 8 D
• the fifth section 28 has a length of about 16 D.
• Rubber 20 a fraction of between 30 and 50% of the total hydrocarbon resin 22, as well as additives 24, are introduced at the beginning of the first section 12.
• the temperature of the first section 12 is kept between 60 and 120°C. Homogenization of the ingredients introduced takes place in the first section 12.
• the remaining fraction of the hydrocarbon resin 22 is introduced at the beginning of the second section 14.
• the temperature of the second section 14 is kept between 60 and 80°C. Further homogenization of the ingredients introduced takes place in the second section 14.
• a fraction of between 5 and 20% of the total solvent 26 is introduced at the beginning of the third section 16.
• the temperature of the third section 16 is kept between 30 and 80°C. Dissolving of the rest of the ingredients in the solvent takes place in the third section 16.
• a further fraction of between 5 and 20% of the total solvent 26 is introduced at the beginning of the fourth section 18.
• the temperature of the fourth section 18 is kept between 20 and 60°C. Further dissolving of the rest of the ingredients in the solvent takes place in the fourth section 18.
• Further fractions of solvent 26 are introduced at the beginning of and along the fifth section 28 so as to reach the desired total quantity of solvent .
• the temperature of the fifth section 28 is kept between 20 and 40°C. Complete dissolving of the rest of the ingredients in the solvent 26 is achieved in the fifth section 28.
• the temperature of the composition produced at the outlet of the extruder 10 must necessarily be less than the boiling point of the solvent 26 used.
• a further variant of the production method of the invention is described with reference to Figure 3.
• a first section 12, a second section 14, and a third section 16, arranged in succession, are distinguished in the extruder 10.
• the first section 12 has a length of about 20 D
• the second section 14 has a length of about 12 D
• the third section 16 has a length of about 24 D.
• Rubber 20, hydrocarbon resin 22, and additives 24 are introduced at the beginning of the first section 12 and a fraction of between 2 and 10% of the total solvent 26 is introduced at a distance of 4 D from the beginning of the extruder 10.
• the temperature of the first section 12 is kept between 40 and 80°C. Homogenization of the ingredients introduced takes place in the first section 12.
• a fraction of between 5 and 20% of the total solvent 26 is introduced at the beginning of the second section 14.
• the temperature of the second section 14 is kept between 30 and 60°C. Dissolving of the rest of the ingredients in the solvent 26 takes place in the second section 14.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Processes Of Treating Macromolecular Substances (AREA)
• Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Extrusion Moulding Of Plastics Or The Like (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (11)

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Citations (11)

Family Cites Families (4)

• 2002
  • 2002-07-03 IT IT2002TO000578A patent/ITTO20020578A1/it unknown
• 2003
  • 2003-06-30 WO PCT/EP2003/006928 patent/WO2004005007A1/en not_active Ceased
  • 2003-06-30 JP JP2004518635A patent/JP4340628B2/ja not_active Expired - Fee Related
  • 2003-06-30 CN CNB038196328A patent/CN100400266C/zh not_active Expired - Fee Related
  • 2003-06-30 BR BRPI0312540-8A patent/BR0312540B1/pt not_active IP Right Cessation
  • 2003-06-30 EP EP03762558A patent/EP1539457B1/en not_active Expired - Lifetime
  • 2003-06-30 AT AT03762558T patent/ATE337903T1/de active
  • 2003-06-30 US US10/519,493 patent/US7875221B2/en not_active Expired - Fee Related
  • 2003-06-30 DE DE60308038T patent/DE60308038T2/de not_active Expired - Lifetime
  • 2003-06-30 AU AU2003249905A patent/AU2003249905A1/en not_active Abandoned
  • 2003-06-30 ES ES03762558T patent/ES2270106T3/es not_active Expired - Lifetime

Patent Citations (11)

Non-Patent Citations (3)

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