Classifications

• • 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
  • C08K5/36—Sulfur-, selenium-, or tellurium-containing compounds
  • C08K5/41—Compounds containing sulfur bound to oxygen
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C1/00—Tyres characterised by the chemical composition or the physical arrangement or mixture of the composition
  • B60C1/0025—Compositions of the sidewalls
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L21/00—Compositions of unspecified rubbers

Definitions

• the present invention relates to a tire covering comprising sidewalls which comprise a vulcanized composition based on at least one elastomer, and to a method for forming a uniform and varnished film on at least one of said sidewalls.
• the invention applies in particular to the protection of said envelope against the effects of migration of antioxidants and anti-ozonants present in said flanks, effects which are visible on the respective external faces of said flanks.
• the most effective anti-ozonating agents are also characterized by a very strong ability to migrate through the elastomeric substrate and to stain and color the surfaces adjacent to said substrate. More specifically, we see appearing on the surface of said flanks yellowish or brown spots. This phenomenon is known as "coloring”. In addition, it turns out that the waxes also migrate to the surface of the sides, this migration having the effect of making said surface dull and gray, or even whitish. This phenomenon is known as "efflorescence".
• the object of the present invention is to provide a tire covering comprising sidewalls which comprise a vulcanized composition based on at least one elastomer, which makes it possible to remedy the drawbacks generated by these undesirable phenomena.
• a tire casing according to the invention is such that said composition comprises in combination:
• a polymer comprising, on either side of an oxy radical of formula -O-, respectively an alkyl group and at least one alkene polyoxide block which corresponds to the formula (C n H 2n O) z and which is linked to a hydrogen atom at the end of the chain, so that said hydrogen atom forms an alcohol function with the terminal oxygen atom of said polyene alkoxide , and
• a salt of an alkali metal of an alkylsulfonic or alkylsulfuric acid In an amount between 0.5 and 10 phr, a salt of an alkali metal of an alkylsulfonic or alkylsulfuric acid.
• This plain film has the advantage of giving said flanks an unblemished appearance, so that it is thus completely remedied the aforementioned undesirable effects of said coloring and efflorescence phenomena.
• said film gives said sides a varnished appearance, that is to say gloss like varnish, which significantly improves their aesthetics.
• said polymer with an oxy radical comprises polyoxyethylene and polyoxypropylene blocks.
• said polymer with an oxy radical corresponds for example to the formula:
• RO- (C 3 H 6 O) - (C 2 H 4 O) y -H where R is a cut of alkyl groups having 13 to 15 carbon atoms (R has mainly 14 carbon atoms), the mass molecular of said polymer with an oxy radical ranging from 500 g / mol to 1100 g / mol, x being able to vary appreciably from 3 to 15 and y possibly varying from 3 to 5.
• This polymer with an oxy radical advantageously has a molecular mass which is substantially equal to 670 g / mol (in this case, x is equal or substantially equal to 5 and y is equal or substantially equal to 4), or 510 g / mol ( in this case, x and y are each equal or substantially equal to 3), or alternatively 1050 g / mol (in the latter case, x is equal or substantially equal to 15 and y is equal or substantially equal to 4).
• said polymer with an oxy radical is present in said composition in an amount substantially equal to 2 phr.
• said salt of an alkali metal is a sodium salt present in said composition in an amount substantially equal to 5 phr, and corresponding to the formula: R'-SO z -Na, where R 'is a blend of alkyl groups having 3 to 17 carbon atoms, and z is an integer equal to 3 or 4.
• R 'can for example have a majority of 8 carbon atoms or else 15 carbon atoms.
• R ' may for example have a majority of 8 carbon atoms or else 13 carbon atoms.
• said elastomer composition comprises at least one anti-ozonating agent and / or at least one antioxidant agent.
• Said anti-ozonating agent belongs for example to the group consisting of 2, 4, 6-tris (Nl, 4-dimethyl pentyl -p- phenylene diamino) 1, 3, 5 triazine and N, N 'di (1, 4 dimethylpentyl) -p-phenylenediamine.
• said antioxidant agent it consists for example of N- (1,3-dimethyl butyl) - N'-phenyl-p-phenylene diamine.
• a method according to the invention for the formation of a uniform and varnished film on the external face of at least one of the sidewalls of a tire consists in using an envelope according to the invention as defined above , and to expose statically for at least 48 hours, in an enclosure maintained at a temperature substantially equal to or greater than 25 ° C., said or each flank to an ozone environment which is such as the concentration of ozone dosed in the ambient air is substantially equal to or greater than 20 parts per hundred million, for the formation of said film with, for the latter, a thickness obtained substantially equal to or greater than 0.5 microns.
• said concentration of ozone dosed in ambient air is substantially equal to or greater than 40 parts per hundred million.
• This film also has the advantage of giving said flanks an unblemished appearance, so that the aforementioned undesirable effects are remedied in the same way, with the obtaining of a shiny appearance for said or each flank.
• CBS 1 pce zinc oxide: 3 pce stearic acid: 1 pce
• the "6PPD” is N- (1,3-dimethyl butyl) -N'-phenyl-p-phenylenediamine, agent both anti -oxidizing and anti-ozonating
• "Durazone 37” is the trade name of an anti-ozonating agent consisting of a triazine substituted by phenylene diamine, whose name is 2, 4, 6-tris (Nl, 4- dimethyl pentyl -p- phenylene diamino) 1, 3, 5 triazine
• the “CBS” is N-cyclohexyl-benzothiazyl-sulfenamide, vulcanization accelerator.
• an anti-static agent A sold by the company CLARIANT under the name HOSTASTAT HS1, at a rate of 5 pce.
• R-SO 3 - Na It is a sodium salt of an alkylsulfonic acid corresponding to the formula R-SO 3 - Na, where R is a blend of alkyl groups having respectively 3 to 17 carbon atoms, and having mainly 15 atoms of carbon;
• surfactant B sold by the company ICI under the name SYNPERONIC LF / RA 280, at a rate of 2 phr.
• polyoxyethylene block is linked to a hydrogen atom at the end of the chain, so that the latter forms an alcohol function with the terminal oxygen atom of said polyoxyethylene block.
• the molecular mass of this surfactant B is approximately 670 g / mol.
• a surfactant B sold by the company ICI under the name SYNPERONIC LF / RA 260, at a rate of 2 phr. It is a polymer comprising, on either side of an oxy radical of formula -O-, respectively a cut R of alkyl groups having from 13 to 15 carbon atoms, and polyoxyethylene and polyoxypropylene blocks, according to the formula:
• a surfactant B sold by the company ICI under the name SYNPERONIC LF / RA 310, at a rate of 2 phr. It is a polymer comprising, on either side of an oxy radical of formula -O-, respectively a cut R of alkyl groups having from 13 to 15 carbon atoms, and polyoxyethylene and polyoxypropylene blocks, according to the formula:
• an anti-static agent A consisting of a sodium octanesulfonate sold by the company STEPAN under the name "BIO-TERGE PAS-8 S" and which was dried beforehand, at a rate of 5 phr,
• an anti-static agent A consisting of a sodium octyl sulphate sold by the company RHODIA under the name "RHODAPON OLS" and which was dried beforehand, at a rate of 5 phr,
• an anti-static agent A consisting of a sodium tridecyl sulphate sold by the company RHODIA under the name "RHODAPON TDS" and which was dried beforehand, at a rate of 5 phr,
• anti-static agent A sold under the name "HOSTASTAT HS1", at rates of between 0.5 and 10 pce and
• the vulcanized envelopes respectively obtained according to Examples 1 to 16 were placed under static conditions in an outdoor atmosphere of urban type, at 20 ° C. and protected from the sun and rain. .
• This atmosphere is such that the ozone concentration measured in atmospheric air is approximately 4 parts per hundred million. This placement was carried out so as to expose each flank to this open atmosphere, for a period of 2 months.
• the vulcanized envelopes according to Examples 1 to 16 were placed under static conditions in an outdoor atmosphere of urban type, at 25 ° C. and protected from the sun and rain. This atmosphere is also such that the ozone concentration measured in atmospheric air is close to 4 parts per cent million. This placement was carried out so as to expose each flank to this open atmosphere, this time for a period of 5 months.
• the vulcanized envelopes according to Examples 1 to 16 were placed under static conditions in an ozonization enclosure, consisting of a closed chamber whose ozone concentration dosed in the air was about 40 parts per hundred million and whose interior temperature was 25 ° C. This placement was carried out so as to expose each flank to this closed atmosphere, for a period of 7 days.
• the vulcanized envelopes according to Examples 1 to 16 were placed under static conditions in an ozonization enclosure, consisting of a closed chamber whose ozone concentration dosed in the air was this time about 50 parts per hundred million and whose interior temperature was 38 ° C. This placement was carried out so as to expose each flank to this closed atmosphere, this for a period of 24 or 72 hours.
• the vulcanized envelopes according to Examples 1 to 16 were placed under static conditions in an ozonization enclosure, consisting of a closed chamber whose ozone concentration dosed in the air was about. 200 parts per hundred million and whose interior temperature was 25 ° C. This placement was carried out so as to expose each flank to this closed atmosphere, this for a period of 48 hours. As previously, at the end of this placement, the presence of a uniform and varnished film with an average thickness of 1.5 ⁇ m was observed, so that the flanks were completely free of stains and had a shiny appearance.
• the envelopes which have undergone the ozonization treatment in an enclosure are placed in the open air and under static conditions according to each of the last three methods mentioned above, under the conditions specified in said first and second modes.
• sidewalk grating friction of the sides provided with said films against a sidewalk for a few meters to determine a possible detachment or disappearance thereof;
• washing test of the resistance of said films to washing by rubbing with an aqueous solution comprising soap.
• test tubes were subjected to ozonation which respectively comprise the vulcanized compositions according to Examples 1 to 16 according to the invention, following the aforementioned fourth method of placement (in an enclosure containing 50 parts per hundred million ozone , at 38 ° C, for 24 hours and with a static surface deformation under extension of 18%). Measurements of degree of gloss were carried out on these "test pieces” 1 to 16, so as to objectively characterize the varnished nature of the films thus obtained.
• vulcanized rubber plates were used for these "test pieces" using a mold called “teflon-coated then treated with ozone as indicated above, each consisting of a stack of two half-plates .
• Each half plate has a height of 1.5 mm, a length of 15 cm and a width of 14 cm.
• Each upper plate consists of a mixture for sidewalls according to one or other of the examples 1 to 16.
• This "teflon-coated" mold is defined, on the one hand, by the steel the constituent which corresponds to the name Z3 CN 18-10 (AFNOR nomenclature) and, on the other hand, by the treatment by projectile jets followed by a “teflonnage” which one makes him undergo.
• This treatment by projectile jets is intended to obtain a determined roughness value Ra (arithmetic mean deviation of the profile), which is between 2 and 4 ⁇ m.
• a roughness tester sold under the name "MITOTUYO, SURTRONIC series” is used for all roughness measurements.
• the length L m of evaluation of the roughness on the plates is chosen equal to 4 mm, and the elementary length (measurement threshold L e by the roughness sensor, or cut-off) is chosen equal to 0.8 mm.
• said sensor it is a diamond type sensor and its displacement speed is 0.25 mm / s.
• This treatment of projectile jets is carried out at a pressure of 3 bar, at a jet distance equal to 10 cm and at a normal incidence.
• the projectiles used consist of particles of white corundum (alumina), which have an average dimension of 80 ⁇ m and a normalized dimension of 150 mesh (according to standard NF XII- 508).
• a first step spraying polytetrafluoroethylene on the internal face of the mold wall, so as to obtain a thickness of 10 to 15 ⁇ m of spray on said face. Drying is then carried out at 250 ° C. for 5 minutes, then cooling, and
• Ra which is between 0.5 and 1.2 ⁇ m, which range thus determines a surface condition determined for the two half-plates vulcanized and treated with ozone, for gloss measurements.
• varnished films with which the envelopes according to the invention are provided are such that they clearly show the various markings usually affixed on the sides, during their preparation and during subsequent tests.
• the flank markings are visible with a greater contrast compared to the rest of the external face of said flanks.
• varnished films of the envelopes according to the invention remain practically intact after use in driving.

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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)
• Tires In General (AREA)
• Treatments Of Macromolecular Shaped Articles (AREA)

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• 2000
  • 2000-07-12 ES ES00944030T patent/ES2202148T3/es not_active Expired - Lifetime
  • 2000-07-12 KR KR1020017003188A patent/KR100648851B1/ko not_active Expired - Fee Related
  • 2000-07-12 AU AU58275/00A patent/AU765652B2/en not_active Ceased
  • 2000-07-12 EP EP00944030A patent/EP1131377B1/fr not_active Expired - Lifetime
  • 2000-07-12 JP JP2001509414A patent/JP4796724B2/ja not_active Expired - Fee Related
  • 2000-07-12 DE DE60003629T patent/DE60003629T2/de not_active Expired - Lifetime
  • 2000-07-12 WO PCT/EP2000/006621 patent/WO2001004203A1/fr not_active Ceased
• 2001
  • 2001-03-08 US US09/801,520 patent/US6554037B2/en not_active Expired - Lifetime

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