Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D183/00—Coating compositions based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon, with or without sulfur, nitrogen, oxygen, or carbon only; Coating compositions based on derivatives of such polymers
  • C09D183/04—Polysiloxanes
• • 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
  • B29C33/00—Moulds or cores; Details thereof or accessories therefor
  • B29C33/56—Coatings, e.g. enameled or galvanised; Releasing, lubricating or separating agents
  • B29C33/60—Releasing, lubricating or separating agents
  • B29C33/62—Releasing, lubricating or separating agents based on polymers or oligomers
  • B29C33/64—Silicone
• • 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
  • B29D30/00—Producing pneumatic or solid tyres or parts thereof
  • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
  • B29D30/0601—Vulcanising tyres; Vulcanising presses for tyres
  • B29D30/0654—Flexible cores therefor, e.g. bladders, bags, membranes, diaphragms
• • 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
  • B29D30/00—Producing pneumatic or solid tyres or parts thereof
  • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
  • B29D30/0601—Vulcanising tyres; Vulcanising presses for tyres
  • B29D30/0662—Accessories, details or auxiliary operations
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
  • C08J7/04—Coating
  • C08J7/0427—Coating with only one layer of a composition containing a polymer binder
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
  • C08J7/04—Coating
  • C08J7/043—Improving the adhesiveness of the coatings per se, e.g. forming primers
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D183/00—Coating compositions based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon, with or without sulfur, nitrogen, oxygen, or carbon only; Coating compositions based on derivatives of such polymers
• • 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
  • B29D30/00—Producing pneumatic or solid tyres or parts thereof
  • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
  • B29D30/0601—Vulcanising tyres; Vulcanising presses for tyres
  • B29D30/0654—Flexible cores therefor, e.g. bladders, bags, membranes, diaphragms
  • B29D2030/0655—Constructional or chemical features of the flexible cores
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2321/00—Characterised by the use of unspecified rubbers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2483/00—Characterised by the use of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen, or carbon only; Derivatives of such polymers
• • 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
  • C08K3/18—Oxygen-containing compounds, e.g. metal carbonyls
  • C08K3/24—Acids; Salts thereof
  • C08K3/26—Carbonates; Bicarbonates
• • 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
  • C08K3/34—Silicon-containing compounds
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T152/00—Resilient tires and wheels
  • Y10T152/10—Tires, resilient
  • Y10T152/10495—Pneumatic tire or inner tube

Definitions

• the present invention relates to compositions in the form of silicone curable elastomer emulsion by water evaporation and crosslinking intended to be applied to the vulcanization bladders as a bonding primer during the manufacture of tires.
• the invention also relates to vulcanization bladders coated with a primer according to the invention.
• Rubber tires for vehicles are usually made by molding and vulcanizing a construction made of raw or unvulcanized raw rubber casing in a molding press in which the green envelope is pressed outwardly. against the surface of a mold by means of a butyl rubber bladder (also called “bladder”) expandable by an internal fluid (water vapor, nitrogen, ).
• a butyl rubber bladder also called “bladder”
• the green envelope is shaped against the outer surface of the mold which defines the pattern of the tread of the envelope and the configuration of the sidewalls.
• the casing is vulcanized.
• the bladder is dilated by the internal pressure provided by a fluid such as compressed (hot) gas, hot water and / or steam, which also participates in the heat transfer for vulcanization.
• the envelope is then allowed to cool a little in the mold, this cooling being sometimes favored by the introduction of cold or cooler water into the bladder. Then the mold is opened, the bladder is deflated by releasing the pressure of the internal fluid and the envelope is removed from the envelope mold.
• This use of vulcanization bladders is well known in the art.
• the surface of the bladder also tends to stick on the inner surface of the envelope after the vulcanization of the envelope and during the portion of the vulcanization cycle of the envelope during which the bladder is deflated.
• air bubbles can be trapped between the surfaces of the bladder and the envelope, and promote the occurrence of vulcanization defects of the envelopes resulting from improper heat transfer.
• the bladder coated with the primary is in the majority of cases inflated by injection of a hot gas in order to optimize its elasticity performance, the primary undergoes then an elongation of the order of 300%.
• the molding / demolding cycle is repeated several times depending on the life of the bladder which results in significant physical stresses on the primary.
• the elongation resistance is therefore an important criterion for a primer which must therefore be able to withstand a stretch of 300% on an expandable bladder without physical deterioration while ensuring good affinity with the lubricant compositions used to to optimize the number of molding / demoulding by bladder.
• the primer must also have good adhesion properties on the bladder to avoid any phenomenon of delamination.
• good affinity is meant that the lubricant must adhere to the primary to ensure its action on several molding / demolding cycles.
• composition in the form of a silicone oil in water emulsion, based on siloxane, which does not give off hydrogen, which is useful in the molding-demolding of tires comprising:
• This composition when it is crosslinked on the bladder can play either the role of a lubricant composition, or the role of a primer with sufficient lubricating properties to thereby avoid the application of an additional lubricant composition.
• this type of composition has primer properties still insufficient, especially when the bladder is inflated before its first use to optimize its performance. The primer must then be able to withstand an elongation equivalent to 300% at temperatures ranging from room temperature to temperatures that may be greater than 150 ° C.
• the present invention therefore aims to propose a new use of an aqueous silicone emulsion curable in an elastomer by evaporation of water and crosslinking to form a primer on an expanding bladder for the manufacture of a tire, said primer for:
• said emulsion being composed of:
• a silicone phase consisting of: at least one crosslinkable linear polyorganosiloxane A oil comprising hydroxylated and / or alkoxylated functions with a dynamic viscosity of between 20000 and 2 ⁇ 10 6 mPa ⁇ s, preferably between 70 ⁇ 10 6 3 and 1, 1 x 10 6 mPa.S and even more preferably between 100 x 10 3 and 300 x 10 3 mPa.S,
• crosslinking agent D comprising hydroxylated and / or alkoxylated functions, such as, for example, a hydroxylated and / or alkoxylated polyorganosiloxane resin or a silicone adhesion promoter having hydroxylated and / or alkoxylated crosslinking functions,
• the crosslinking agent D is not a silicone adhesion promoter having hydroxylated and / or alkoxylated crosslinking functional groups
• at least one silicone adhesion promoter B is optionally present, with the proviso that at least one of the constituents A , B, D carries at least three crosslinking functions per molecule, and (ii) a non-silicone hydrophilic phase, consisting of:
• At least one dispersible CH filler in an aqueous phase in a proportion of at least 5% by weight, preferably between 10% and 50% by weight, relative to the total weight of the emulsion;
• At least one polycondensation catalyst C and / or at least one water-soluble adhesion promoter B ', and (Hi) water optionally, at least one polycondensation catalyst C and / or at least one water-soluble adhesion promoter B ', and (Hi) water, said emulsion optionally containing at least one plasticizer G as additional additives and / or at least one bactericide H.
• the constituents of the emulsion are defined with reference to their initial chemical structure, that is to say the one which characterizes them before emulsification. Since they are in an aqueous medium, their structure is likely to be greatly modified following the hydrolysis and condensation reactions.
• dynamic viscosity is meant within the scope of the invention the viscosity of Newtonian type, that is to say the dynamic viscosity, measured in a manner known per se at a given temperature, a sufficiently low shear rate gradient so that the measured viscosity is independent of the velocity gradient.
• the main constituent of the emulsion on a weight basis, is polyorganosiloxane A, which preferably comprises at least one viscous and reactive silicone homopolymer or copolymer, capable of forming, by polycondensation, a three-dimensional crosslinked network in association with a crosslinking agent.
• the functionalities considered are functionalities giving access to a crosslinking, preferably by (hydrolysis) / condensation. These functionalities are hydroxyls or alkoxyls.
• alkoxysilane E By way of examples of alkoxysilane E, mention may be made of: ViSi (OEt) 3 , ViSi (OMe) 3 , Si (OEt) 4 , MeSi (OMe) 3 and Si (OMe) 4 .
• crosslinkable polyorganosiloxane A has the following formula (I):
• - R f hydrogen or a linear or branched C 1 -C 4 alkyl, optionally substituted by a linear or branched C 1 -C 3 alkyl, preferably a methyl, ethyl, propyl or ethoxyethyl;
• - R 3 , R 4 , R 5 , R 6 , R 7 and R 8 are radicals, identical or different, selected from the group consisting of: linear or branched alkyls, C 1 -C 30 , preferably a methyl ; linear or branched C 2 -C 20 alkenyls, C 5 -C 12 aryls, optionally substituted with 1 to 3 linear or branched C 1 -C 3 alkyls, the aralkyls comprising for the C 6 -C 6 aryl part; C 8 carbon atoms and for the linear or branched C 1 -C 4 alkyl moiety, such as benzyl, phenethyl or the
• R N corresponds to identical or different radicals between them which define themselves as amine radicals, preferably aminoalkyl or alkyl radicals comprising one or more epoxide and / or carboxylic functions and / or methacryloxy and / or mercapto and / or isocyanates and / or isocyanurates and / or cyano;
• R e represents radicals that are identical to or different from one another, which are defined as being radicals corresponding to the same definition as that given above for R 3 to R 8 and / or radicals corresponding to the same definition as that given above for R N ;
• the crosslinkable polyorganosiloxane A is a silicone oil formed by a homo or a copolymer of formula (I) given above, in which:
• R e , R3 to R8 are radicals identical to or different from each other and chosen from the group consisting of:
• R 9 and R 10 which may be identical or different, represent: a C 1 -C 6 alkyl; C 3 -C 8 cycloalkyl; C 2 -C 8 alkenyl; C 5 -C 8 cycloalkenyl, aryl, alkylarylene and arylalkylene; each of the aforementioned radicals being optionally substituted by a halogen atom (and preferably flu
• R 9 and R 10 are independently chosen from the group of radicals consisting of: a methyl, an ethyl, a propyl, an isopropyl, a cyclohexyl , vinyl, phenyl, and 3,3,3-trifluoropropyl.
• R 9 and R 10 are independently chosen from the group of radicals consisting of: a methyl, an ethyl, a propyl, an isopropyl, a cyclohexyl , vinyl, phenyl, and 3,3,3-trifluoropropyl.
• at least about 80% by number of these radicals are methyl radicals.
• crosslinkable polyorganosiloxane oil A to ⁇ , ⁇ -dihydroxy-poly (dimethyl) (methylphenyl) siloxane oils, and in particular to oils of this type prepared by the anionic polymerization process described in US Pat. aforementioned US patents: US-A-2,891,920 and especially US-A-3,294,725 (cited as reference).
• This emulsion polymerization process is particularly advantageous because it makes it possible to directly obtain an emulsion containing the polyorganosiloxane A. Moreover, this process makes it possible to obtain, without difficulty, polyorganosiloxane A oils in high viscosity emulsion.
• it will be preferred, however, from polyorganosiloxane oils already polymerized for the preparation of the emulsion for example using the emulsification techniques of the silicone phase described in FR-A-2 697 021.
• the dynamic viscosity ⁇ at 25 ° C. of these polyorganosiloxanes A is, moreover, necessary for the dynamic viscosity ⁇ at 25 ° C. of these polyorganosiloxanes A to be between 20,000 and 2 ⁇ 10 6 mPa ⁇ s, preferably between 70 ⁇ 10 3 and 1.1 ⁇ 10 6 mPa ⁇ s. and even more preferably between 100 x 10 3 and 300 x 10 3 mPa.S.
• the dynamic viscosity ⁇ of the polyorganosiloxane A is one of the essential characteristics for obtaining a primer having a set of suitable mechanical properties, in particular for elongation at break and adhesion to the bladder.
• the charges CH used can be, for example, reinforcing siliceous CH fillers.
• siliceous fillers have a particle size generally between a few nanometers and 300 microns and a BET surface greater than 50 m 2 / g.
• These siliceous fillers are chosen eg from colloidal silicas, silica powders for combustion and precipitation, or mixtures thereof. These silicas are well known, they are used, in particular, as fillers in silicone elastomer compositions, hot vulcanizable into a silicone rubber. These silicas have an average particle size, generally less than 0.1 ⁇ m and a BET specific surface area preferably between 100 and 350 m 2 / g.
• siliceous fillers such as diatomaceous earths, ground quartz, micas, or optionally hydrated alumina or titanium dioxide may also be used.
• the dispersible CH feedstock in the aqueous phase is selected from the group consisting of colloidal silicas, silica powders for combustion and precipitation, calcium carbonate and mixtures thereof.
• These CH fillers are introduced into the emulsion in the form of dry powder or in the form of colloidal emulsions, for example by simple mixing.
• crosslinking D there may be mentioned a hydroxylated and / or alkoxylated silicone resin having a weight content of hydroxyl groups and / or alkoxyls, between 0.1 and 10%, preferably between 0.2 and 5%.
• silicone resins are well-known branched organopolysiloxane polymers whose methods of preparation are described in numerous patents.
• resins that may be used include MQ resins, MDQ resins, TD resins and MDT resins. Resins that are solid or liquid at room temperature can be used. These resins can be incorporated as such into the emulsions in the polyorganosiloxane A, in solution in an organic solvent or a silicone oil, or in the form of aqueous emulsions (EP-A-0 359 676).
• Aqueous emulsions of silicone resins that can be used are, for example, described in US-A-4,028,339, US-A-4,052,331, US-A-4,056,492, US-A-4,525,502 and US-A. -4,717,599 cited as reference.
• this resin D can act as a crosslinking agent by virtue of its hydroxyl and / or alkoxyl functions, able to react by condensation with the crosslinkable groups of the silicone oil A.
• the crosslinking agent D is a polyorganosiloxane resin carrying condensable hydroxyl substituents and comprising at least two different siloxyl units chosen from those of formula (R 11 ) 3 SiO 1/2 (M); (R 11) 2 SiC> 2/2 (D); R 11 SiO 3Z 2 (T) and SiO 4/2 (Q), at least one of these units being a T or Q unit, in which formula R 11 represents a monovalent organic substituent as defined above and said resin exhibiting a weight content of hydroxyl substituents of between 0.1 and 10% by weight, and preferably between 0.2 and 5% by weight.
• MQ resins 1 As concrete examples of resins that may be used, mention may be made of MQ resins 1
• each OH group is carried by a silicon atom belonging to an M, D or T unit.
• examples of resins that may be used include hydroxylated organopolysiloxane resins not comprising, in their structure, a Q-unit. More preferentially, mention may be made of hydroxylated DT and MDT resins comprising at least 20% by weight of T-units and having a weight content of hydroxyl group ranging from 0.1 to 10% and more preferably from 0.2 to 5%. In this group of more preferential resins, those in which the average number of substituents R 11 for a silicon atom is comprised, per molecule, between 1, 2 and 1, 8, are more particularly suitable. Even more advantageously, resins of this type are used, in the structure of which at least 80% by number of the substituents R 11 are methyl radicals.
• the resin is liquid at room temperature.
• the resin has a dynamic viscosity at 25 ° C. of between 0.2 and 200 Pa.s, especially between 0.5 and 50 Pa.s, better still between 0.8 and 5 Pa.s.
• said emulsion is diluted for compressed air spray applications, so that the amount of water is between 0.5% and 55%, preferably between 1.5% and 45%. and even more preferably between 30% and 45%, by weight relative to the total weight of the emulsion.
• polycondensation catalysts C examples include organometallic salts, and titanates such as the orthotitanate of tetrabutyl.
• organometallic salt there may be mentioned zirconium naphthenate and zirconium octylate.
• Said catalyst is preferably a catalytic compound with tin, usually an organotin salt.
• organotin salts which can be used are described in particular in the work of NOLL, Chemistry and Technology of Silicones Academy Press (1968), page 397. It is also possible to define, as catalytic compound, either distannoxanes or polyorganostannoxanes, or the reaction product of a tin salt, especially a tin dicarboxylate on ethyl polysilicate, as described in US-A-3,862,919.
• the reaction product of a sodium silicate, alkyl or an alkyltrialkoxysilane on dibutyltin diacetate as described in Belgian Patent BE-A-842 305 may also be suitable.
• the catalyst is the tin salt of an organic acid, such as dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin dioctate, zinc naphthenate, cobalt naphthenate, zinc octylate, cobalt octylate and dioctyltin di (isomercaptoacetate).
• an organic acid such as dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin dioctate, zinc naphthenate, cobalt naphthenate, zinc octylate, cobalt octylate and dioctyltin di (isomercaptoacetate).
• the preferred tin salts are tin bischelates (EP-A-147,323 and EP-A-235,049), diorganotin dicarboxylates and, in particular, the catalysts described in GB-A-1,289. 900 such as dibutyl or dioctyltin diacetate, dibutyl or dioctyltin dilaurate or the hydrolysis products of the aforementioned species (for example diorgano and polystannoxanes).
• the polycondensation catalyst C is generally introduced into the emulsion in a proportion of 0.05 to 5 parts by weight, relative to the total weight of the emulsion.
• Dioctyltin dilaurate or di- (2-ethylhexyl) -tin dilaurate is particularly preferred.
• the nature of the surfactant TA will be easily determined by those skilled in the art, the objective being to prepare a stable emulsion.
• the anionic, cationic, nonionic and zwitterionic surfactants can be used alone or as a mixture.
• alkali metal salts of aromatic hydrocarbon sulfonic acids or alkali metal salts of alkylsulphuric acids there may be mentioned alkali metal salts of aromatic hydrocarbon sulfonic acids or alkali metal salts of alkylsulphuric acids.
• Nonionic surfactants are more particularly preferred in the context of the invention.
• polyalkylene ether aryl ether mention may be made of polyoxyethylenated alkylphenols.
• alkyl ether of polyalkylene oxide mention may be made of polyethylene glycol isodecyl ether and polyethylene glycol trimethylnonyl ether containing from 3 to 15 ethylene oxide units per molecule. Mention may also be made of ethoxylated isotridecyl alcohol, eg with from 8 to 9 moles of ethylene oxide per mole of isotridecyl alcohol.
• the amount of surfactant TA is a function of the type of each constituent present and the nature of the surfactant used.
• the emulsion comprises from 0.5 to 10% by weight of surfactant (more preferably from 0.5 to 5% by weight).
• the surfactant TA is present up to 3% by weight relative to the total weight of the emulsion.
• the emulsion according to the invention has the following composition in parts by weight: of at least 100 parts of an ⁇ - ⁇ -dihydroxylated polydiorganosiloxane silicone oil A,
• adhesion promoter B and / or B 'chosen from the group consisting of: the product of hydrolysis of an aminoalkyltrialkoxysilane, bis-aminoalkyltrialkoxysilane and / or tris-aminoalkyltrialkoxysilane, the oligomers or amino silicone resins comprising D, T and / or Q siloxyl units, optionally M, with at least part of the D, T and M units carrying one or more amino functionalities,
• the hydroxylated silicone resins preferably from the resins of the genus T (OH) , DT (OH) , DQ (OH) , DT (OH) , MQ (OH) , MDT (OH) , MDQ (OH) and their mixtures, these resins having silicates substituted by vinyl radicals, and / or phenyl and / or trifluoro-
• siliceous filler CH preferably selected from the group consisting of: a precipitated silica or not, a colloidal or powdered silica, the micas and the mixtures of these products,
• siliceous additive AS such as sodium silicate or organosilicate.
• adhesion promoters B or B ' are known to those skilled in the art which according to their nature will be preferentially soluble in the aqueous phase or in the silicone phase.
• the optional organic substituents of adhesion promoters B or B 'other than the OH group (s) and the organic group (s) with Fr function are: linear alkyl radicals or branched, having 1 to 6 carbon atoms; cycloalkyl radicals having 3 to 8 carbon atoms; linear or branched alkenyl radicals having from 2 to 8 carbon atoms; aryl radicals having from 6 to 10 carbon atoms; alkylarylenes having 6 to 15 carbon atoms; or arylalkylene radicals having 6 to 15 carbon atoms.
• the solubility in the silicone phase and / or the hydrophilic phase being a function
• Fr is an optionally substituted amino function.
• the water-soluble adhesion promoter B has the formula:
• R 12 R 13 NR 9 -Si (OH) 3 in which R 9 represents a C 1 -C 10 alkylene radical and R 12 and R 13 independently represent a hydrogen atom or a (C 1 -C 6 ) alkyl group .
• R 9 represents a C 1 -C 10 alkylene radical
• R 12 and R 13 independently represent a hydrogen atom or a (C 1 -C 6 ) alkyl group .
• 3-aminopropyltrihydroxysilane is used in a proportion of 0.5 to 15 parts by weight relative to the total weight of the emulsion, preferably in the proportion of 0.6 to 5 parts by weight, and more preferably 0.8 to 3 parts by weight.
• plasticizers G mention may be made, although this is not limiting, of the alkylbenzenes and, in particular, those described in the patent application FR 2,446,849.
• the emulsion of the invention as defined above is, furthermore, characterized in that it comprises droplets of silicone dispersed phase in at least partially crosslinked form.
• the emulsion can be stored in this form, before use, in an appropriate packaging, protected from the air. And it is only after application on the bladder that the droplets of dispersed silicone phase merge by coalescence to form a homogeneous material, which then finishes its transformation into an elastomer by crosslinking and removal of water (evaporation).
• the preparation of the aqueous silicone emulsion may be carried out from an emulsion of at least a portion of the silicone phase (i) in an aqueous phase containing at least a part of the hydrophilic phase (H) and / or water, using mechanical stirring means.
• the silicone phase (i) which is emulsified in the aqueous phase, comprises all or part of its constituents [A, B, D, inter alia] before the actual emulsification stage ( mixing / homogenization - stirring) with the aqueous phase (non-silicone hydrophilic phase (M)).
• the CH charge of the non-silicone hydrophilic phase is preferably added to the mixture after emulsification.
• the emulsification is advantageously carried out using conventional homogenization and stirring means, such as, for example, kneaders, planetary mixers, colloid mills, single or twin screw extruders, or homonenizers. at a temperature for example between 10 and 50 ° C.
• the pH is optionally adjusted between 4 and 13 by addition of acid or organic or inorganic base (eg potash, amine).
• the final emulsion obtained is homogenized, then optionally degassed, and is then packaged in airtight and steam-proof packaging.
• the emulsion can be stored in this form, before use, in an appropriate packaging, protected from the air.
• This emulsion is intended to be applied to an expandable bladder before use of a lubricating composition.
• the application of this emulsion can be carried out by conventional methods such as spraying, brushing, application using a sponge or a brush. It is only after application on the bladder that the droplets of the silicone phase (i) merge by coalescence to form a homogeneous material, which then completes its transformation into an elastomer by crosslinking and removal of water (evaporation).
• the emulsion forms an adherent elastomer on the bladder by crosslinking (e.g., polycondensation) accompanied by removal of water (preferably at room temperature).
• This primer has proved to be particularly useful in combination with lubricant compositions (or mold release agents) lacking groups (SiH), and more particularly with the lubricating compositions described in applications FR-A-2802546, FR-A-2825099, FR-A-2838447 and WO-03/087227.
• the release agent is either applied to the primed bladder or the inner surface of the uncured tire ("the inner liner"). This combination allows the uncured tire to slide on the bladder (bladder) when the press closes while ensuring a smooth unfolding step of the molded tire (vulcanized).
• the primary system according to the invention / release agent prevents adhesion of the vulcanized tire on the bladder.
• the number of demoulding possible by application of release agent, but also the number of possible moldings by bladder is increased without loss of quality in the vulcanized tire, particularly in terms of the symmetry of the tires thus obtained.
• the present invention therefore also relates to the method of applying the oil-in-water emulsion which has just been described on the surface of an expandable bladder, as a primer.
• the crosslinking is carried out by drying at room temperature, which can be accelerated by heating, in particular at 80-180 ° C., preferably at 120-170 ° C.
• the invention also relates to an expandable rubber bladder coated on its outer surface with an aqueous silicone emulsion curable in an elastomer by evaporation of water and crosslinking as described above, for the shaping and vulcanization of bandages. pneumatic or semi-pneumatic. The life of this bladder thus obtained is lengthened.
• Another subject of the invention consists of an expandable rubber bladder coated with a primer according to the invention obtainable by drying and / or heating a bladder at a temperature of 20 to 180 ° C. .
• the last subject of the invention relates to the use of an expandable rubber bladder coated with an adhesion primer according to the invention in combination with a non-vulcanized tire whose inner surface has been treated with a lubricating composition for the manufacture of tires.
• Example 1 The following examples which illustrate the invention demonstrate the excellent properties of the primers from the emulsions according to the invention.
• Example 1 The following examples which illustrate the invention demonstrate the excellent properties of the primers from the emulsions according to the invention.
• This example illustrates an emulsion according to the invention.
• the formulation of this composition which is an oil-in-water emulsion, is given in Table 1 below:
• the promoter B 1 is an aqueous solution of T (OH) amine resin prepared by producing a 40% aqueous solution of gamma-aminopropyl triethoxysilane, then stripping the ethanol formed by hydrolysis.
• the solution is perfectly clear and has a solids content of 23%.
• Example 2 a) Emulsions A (Invention), B and C (Comparative) are applied by spray using a compressed air gun to a rubber plate from a bladder (butyl type rubber). After drying for one hour at room temperature, the plate is placed in an oven at 170 ° C. for 10 minutes in order to allow complete evaporation of the water and to accelerate the crosslinking. The quantity of product applied is determined by difference in weight (layer of approximately 5 mg / cm 2 ).
• Each bladder plate coated with the primer to be tested is then subjected to an extension of 300%.
• the primer layer is then examined using a binocular magnifier (x20) to assess the presence of cracks in the primer during extension and / or after extension.
• the primer obtained from emulsion A has no cracks.
• the primer obtained from emulsion B has cracks and does not hold a 300% elongation.
• the primer obtained from emulsion C shows no crack.
• a bladder coated with a primer obtained from emulsion A (Invention) obtained according to the protocol described in Example 2 (steps (a) and (b)) is spray-treated with a standard lubricant composition (lubricant silicone composition XR3900 RTU provided by Rhodia). The operation is repeated with a bladder coated with a primer derived from emulsion C
• the durability of the system corresponds to the number of tires made without degradation of the surface of the inflatable bladder.
• the bladder to be tested is pressed in contact with an unvulcanized tire casing film, according to a series of pressure and temperature cycles simulating the manufacturing steps of a tire on the industrial tool (typically baking at 170 ° C.). ° C for 7 minutes for each molding / demolding cycle for a passenger car tire).
• the tire casing film is replaced at each feed.
• the test is finished when the two surfaces in contact remain stuck.
• the primer coated bladder from emulsion A allows more than 40 molding / demolding cycles without bonding the tire.
• the adhesion of the primary to the bladder is good even after more than 40 molding / demolding cycles.

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• Chemical Kinetics & Catalysis (AREA)
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• Heating, Cooling, Or Curing Plastics Or The Like In General (AREA)
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• 2005
  • 2005-04-08 FR FR0503502A patent/FR2884170B1/fr not_active Expired - Fee Related
• 2006
  • 2006-04-06 JP JP2008504805A patent/JP2008536967A/ja active Pending
  • 2006-04-06 EP EP06743648A patent/EP1899131A2/fr not_active Withdrawn
  • 2006-04-06 CN CNA2006800198069A patent/CN101247934A/zh active Pending
  • 2006-04-06 US US11/910,960 patent/US20090114327A1/en not_active Abandoned
  • 2006-04-06 WO PCT/FR2006/000764 patent/WO2006106236A2/fr active Application Filing
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