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
  • B29C73/00—Repairing of articles made from plastics or substances in a plastic state, e.g. of articles shaped or produced by using techniques covered by this subclass or subclass B29D
  • B29C73/16—Auto-repairing or self-sealing arrangements or agents
  • B29C73/163—Sealing compositions or agents, e.g. combined with propellant agents
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
  • B29L2030/00—Pneumatic or solid tyres or parts thereof

Definitions

• the invention refers to a composition of a pseudo-plastic non-Newtonian viscous fluid type that achieves the sealing of the elastic wall from rubber of a precinct where there is air under pressure. Practically, the sealing is achieved instantaneously after the accidental breaking of the precinct.
• precincts may be: tubeless tires or with chamber for bicycles, motorbikes and motor vehicles of any type where the inside pressure is between 1 and 10 bars.
• compositions comprised of a liquid support which consists mainly of glycol and water that maintain in suspension fibers, particles and filling material, with additives as antioxidant agents, anti-corrosion and antibacterial (RO 118133 B) are known.
• these compositions must also assure a good anti-corrosion protection at metallic surfaces which this comes into contact with, the corrosion being amplified in the conditions of some high thermal stress.
• a new tendency is the manufacturing of rims from duralumin. This material that represents an alloy ensures the rim with the necessary hardness and a low weight. Exposed at an aqueous system, in high temperature conditions, this material is tested to the cavity corrosion.
• the technical problem, which this invention solves, is represented by the assurance of a high anti-corrosion protection, especially at the elements made of aluminum, in the conditions of some thermal stresses with relative high periods and values.
• the composition minimizes potential precipitation of anti-corrosion component, assuring an increase of the life time of composition in accordance with anti-corrosion protection aspect.
• the corrosion of cavity at aluminum elements is minimized.
• compositions that assure the sealing of elastic wall of one precinct under pressure in the conditions when perforating object has a diameter of 3 mm are known.
• the technical problem that this invention solves is represented by the achievement of one composition used at the tires with/without chamber for vehicles with an operation regime, especially in hard conditions, where the air pressure in the precinct is comprised between 2-6 atmospheres, the loads are of 12-15 t on the axle and the wedges frequency is high, where the perforating object dimension may reach the dimension of 20 mm.
• the composition doesn't have a constant viscosity.
• constant pressure and temperature respectively, its viscosity decreases with the increase of shearing strength and with speed gradient.
• Pseudo-plastic behavior independent of time, is practically registered in operation, at high values of speed gradient, respectively.
• a composition that assures the elastic wall sealing of one precinct where there is air under pressure is the more stable in operation as this has a thixotrope viscoelastic character more pronounced at low values of speed gradient, in this case, the rheologic behavior depends not only of stress size through the parameters of shearing strength and speed gradient, but also of stress period, of stress history.
• the time effect in this case, is reversible, the composition presenting the phenomenon of ,,elastic hysteresis".
• the deviation from non-Newtonian behavior is manifested through modification of fluid viscosity in time at constant stress, determined by modifications in fluid structure.
• the thixotropy phenomenon is evidenced through measurements of viscosity using Brookfield viscosimeter.
• the indicator needle doesn't remain fixed in a stable position on scale but it is slowly moved on dial.
• composition is constituted from 10... 70% softened water, 10... 70% propylene glycol, 0,5...8% natural and/or synthetic fibers, chosen between cellulose, aramide, acrylic, or melamine fibers, the fibers having a length of 0,5...5 mm and a thickness of 1...25 ⁇ m, 0,1... 6% solid particles, chosen from elastomers with a length of 0, 1...4 mm and a thickness of 0,1...
• 0,9 mm consisting of particles of vulcanized rubber treated with esters of unsaturated fatty acids with inferior alcohols and activated with UV radiations and polyethylene pulp, the particles having a thickness of 0,1...5 ⁇ m and a diameter of 0,1...4 mm or mixtures of these, in ratio of 3:1, 5...30% filling material chosen between dextrin or amorphous silica, or mixture of these in ratio 4:1 , 0,1...5% thixotropic agent, chosen between biopolymer based on gum of xanthan, biopolymer based on scleroglucen and cellulose ethers, 0,2...
• 10% lubricant agent chosen between mixtures of ethoxilated esters of sorbitan, mixtures of vegetable or silicone oils, 0,5...5% emulsifier chosen between the active non-ionic ethoxilated surface agents, polvvinylic alcohols and sodium salt of the dinaphtilmethane-disulphonic acid or their mixtures, 2...15% agents of thermal stabilization of polysaccharide polymeric systems, chosen from mixtures in ratio of 1:1:6:8...1:2:10:15 of anti-oxidant agents, consisting of azocompounds, antibacterial, anticorrosion consisting of one aliphatic monocarboxylic acid that contain 3 up to 16 carbon atoms in aliphatic chain, preferentially between 6 up to 12 carbon atoms, the acid being neutralized with an alkaline hydroxide and stabilizers of pH chosen between mixtures of tri-sodium phosphate and borax in ratio of 1:10...1:15, the percents being expressed in weight.
• composition is constituted, in general limits, from:
• the liquid support comprised from 10...70% in weight softened water. Using of softened water is indicated, because the ions of Ca 2+ and Mg 2+ represent catalysts of bio-chemical reactions that lead to system damage.
• the liquid support also contains 10...70% propylene glycol, preferable chosen from toxicity point of view.
• the liquid support assures, on one hand, solids transport that forms the sealing stopper, and on the other hand, assures thermal stability to composition at low temperatures, at freezing, respectively.
• Natural and/or synthetic fibers in proportion of 0,5... 8 % in weight, hydrophilic, preferably, consisting of reactive hydroxyl groups chosen between polysaccharide cellulose fibers or synthetic derivates of these, aramide, acrylic, melamine fibers, the fibers having a length of 0,5...5 mm and a thickness of 1...25 ⁇ m;
• Solid particles in proportion of 0,1...6% in weight, with activated surface preferably, chosen from elastomers with a length of 0,1...4 mm and a thickness of 0,1... 0,9 mm consisting of particles of vulcanized rubber treated with esters of unsaturated fatty acids with inferior alcohols and activated with UV radiations and polyethylene pulp, the particles having a thickness of 0,1...5 ⁇ m and a diameter of 0,1...4 mm or mixtures of these, in ratio of 3:1.
• the activation treatment with UV radiations of the particles of vulcanized rubber, according to invention is made with wave lengths of 200...450 nm and an intensity of 170...220 mW/cm 2 .
• the filling material has agglutination properties, being of organic nature (polysaccharide class) or mineral origin (amorphous silica).
• thixotropic agent one of the following polysaccharide biopolymers may be used: biopolymer based on gum of xanthan or biopolymer based on scleroglucen. Using of biopolymer based on scleroglucen is indicated, this having a good stability due to its non-ionic character in comparison with cationic compounds used regularly as thermal stabilizers.
• the biopolymer based on gum of xanthan has a low anionic character, and in this case it is necessary to establish the compatibility with cationic compounds. Also ethers of cellulose, and carboxymethylcellulose, hydroxiethylcellulose may be used;
• Lubricant agent in proportion of 0,2... 10% in weight, used in order to decrease the torsion and friction, assuring an easier movement of mass composition in comparison with inside wall of the precinct, limiting its adherence at surface.
• Lubricant agent in proportion of 0,2... 10% in weight, used in order to decrease the torsion and friction, assuring an easier movement of mass composition in comparison with inside wall of the precinct, limiting its adherence at surface.
• Mixtures of ethoxilated esters of sorbitan, mixtures of vegetable oils and silicone oils may also be used.
• Emulsifier agent in proportion of 0,5...5% in weight, used in order to avoid forming of agglomerations in mass, layers on stages, assuring a good homogenization of the mixture.
• Active non-ionic ethoxilated agents of surface, polyvynil alcohol and sodium salt of dinaphtilmethanedisulphonic acid may also be used;
• H Agents of thermal stabilization of polysaccharide polymeric systems in proportion of 2...15%, with the purpose of extending the thermal limits of these systems up to high values, chosen from mixtures in ratio of 1:1:6:8...1:2: 10: 15 of anti-oxidant agents, antibacterial agents, anti-corrosion agents and stabilizer agents of pH, as follow: anti-oxidant agents of azocompounds type chosen between triazoles, pyrazoles, izo-oxazoles, izo-thiazoles, thiazoles. Generally, salts of alkaline metals from solubility point of view are used. Preferable, 1 ,2,3 benzotriazole 1 ,2,3- toliltriazole, 2-mercaptobenztiazolate of sodium.
• ti-azocompounds and thiourea may be used.
• anti-bacterial agents in order to prevent polysaccharide fermentation of the polysaccharides present in system.
• Sodium benzoate, tetrametaborate of sodium, cocodiaminediacetate may be used.
• anti-corrosion agents used in order to protect metallic surfaces with which these may come into contact, rim, cord and valve, respectively, against corrosion, consisting of one monocarboxylic aliphatic acid that contains 3 up to 16 carbon atoms in aliphatic chain, preferably between 6 up to 12 carbon atoms, the acid being neutralized with an alkaline hydroxide.
• the acid is chosen between the acids: hexanoic, heptanoic, iso-heptanoic, octanoic, 2-ethyl-hexanoic, nonanionic, decanoic, undecanoic, dodecanoic, neodecanoic or combinations of these.
• the octanoic acid and 2-ethyl-hexanoic acid are preferably used. Because the solubility of these acids decreases as the carbon atoms number increases, their solubility is made in basic solutions of alkaline hydroxide and also sodium and potassium hydroxide.
• composition is presented as a homogeneous gel that keep in constant suspension a mixture of fibers and particles, having an apparent dynamic viscosity measured with Brookfield viscosimeter, using the rotor 4, at rotation speed of 20 rot/min, of 2000 ... 9000 cPs, a pH of 7...10, freezing temperature being of minimum -35°C, and the evaporation temperature of 104 0 C, in normal pressure conditions. But, inside the precinct, the pressure is higher than 1 bar, reaching the value of 10 bar.
• composition presents stability, this is not separated on stages, at a centrifugation of 2500 rot/min for a period of 30 minutes. This speed, assured of a standard centrifuge, corresponds for a tire of 13", one movement speed of 250 km/hour.
• Example 1 In an example of composition achievement for tires of bicycles, motorbikes, where the air pressure in the precinct is less or equal to 2 bar, a composition is constituted from 30...60% in weight softened water, 30...60% in weight propylene glycol, 0,4...2% in weights natural and/or synthetic fibers chosen from cellulose, aramide, acrylic or melamine fibers, the fibers having a length of 0,5...5 mm and a thickness of 1...25 ⁇ m, 0,3...1% in weight solid particles chosen from elastomers with a length of 0,1...4 mm and a thickness of 0,1...0,9 mm consisting of particles of vulcanized rubber treated with esters of fatty acids with inferior alcohols and activated with UV radiations and polyethylene pulp, the particles having a thickness of 0,1.5 ⁇ m and a diameter of 0,1...4 mm or mixtures of these, 8...10% in weight filling material chosen between dextrin and amorphous silica or mixtures of these in ratio
• the composition that can be used is the following: 42% in weight softened water, 38 % in weight propylene glycol, 0,8% in weight cellulose and acrylic fibers in ratio of weight 3: 1 , the fibers having a length of 0,5...5 mm and a thickness of 1 ...25 ⁇ m, 0,4% in weight solid particles constituted from elastomers with a length of 0,1...4 mm and a thickness of 0,1...0,9 ⁇ m consisting of particles of vulcanized rubber treated with esters of unsaturated fatty acids with inferior alcohols and activated with UV radiations and polyethylene pulp, the particles having a thickness of 0,1...5 mm and a diameter of 0,1.
• emulsifier constituted from mixtures of polyvinyl alcohol and sodium salt of dinaphtilmethanedisulphonic acid in weight ratio of 1:3, 4% in weight agents for thermal stabilization of polysaccharide polymeric systems, using mixtures of thiourea, tri-sodium phosphate-borax in ratio of 1 :10, sodium salt of 2-ethylhexanoic, cocodiamineacetate acid.
• the composition has an apparent dynamic viscosity at the speed of 20 rot/min comprised between 2000 and 3000 cPs , with a pH of 7...10 , a freezing temperature of minimum -35 0 C, an evaporation temperature, in conditions of normal pressure, of 104 0 C and a density of 1,05... 1,15 g/cm 3 .
• Example 2 In another example of composition achievement for with/without chamber for vehicles tires, where the air pressure in the precinct is less or equal to 4 bar, a composition is constituted from 25...55% in weight softened water, 25...55% in weight propylene glycol, 0,6...3% in weights natural and/or synthetic fibers chosen from cellulose, aramide, acrylic or melamine fibers, the fibers having a length of 0,5...5 mm and a thickness of 1...25 ⁇ m, 0,3...2% in weight solid particles chosen from elastomers with a length of 0,1...4 mm and a diameter of 0,1...0,9 mm consisting of particles of vulcanized rubber treated with esters of fatty acids with inferior alcohols and activated with UV radiations and polyethylene pulp, the particles having a thickness of 0,1.5 mm and a thickness of 0,1...4 ⁇ m or mixtures of these, 9...18% in weight filling material chosen between dextrin and amorphous silica or mixtures of these in ratio 4:1
• the composition that can be used is the following: 33% in weight softened water, 30,8 % in weight propylene glycol, 1 ,8% in weight aramidic, the fibers having a length of 0,5...5 rnm and a diameter of 1...25 ⁇ m, 8% in weight solid particles constituted from elastomers with a length of 0,1...4 mm and a thickness of 0,1...0,9 ⁇ m consisting of particles of vulcanized rubber treated with esters of unsaturated fatty acids with inferior alcohols and activated with UV radiations and polyethylene pulp, the particles having a thickness of 0,1...5 mm and a diameter of 0,1...4 mm, in weight ratio of 1 :1 , 14% in weight filling material consisting of dextrin, 0,4% in weight thixotropic agent biopolymer based on scleroglucen
• the composition has an apparent dynamic viscosity at the speed of 20 rot/min comprised between 3000 and 6000 cPs , with a pH of 7...10 , a freezing temperature of minimum -35 0 C, an evaporation temperature, in conditions of normal pressure, of 104 0 C and a density of 1 ,07... 1 ,2 g/cm 3 .
• Example 3 In an example of composition achievement for with/without chamber for industrial vehicles tires, agriculture, bus, trucks with tire diameter of 406,4...965, 2 mm, where the air pressure in the precinct is between 4 bar - 10 bar, a composition is constituted from 20...50% in weight softened water, 20...50% in weight propylene glycol, 1...4% in weights natural and/or synthetic fibers chosen from cellulose, aramide, acrylic or melamine fibers, the fibers having a length of 0,5...5 mm and a thickness of 1...25 ⁇ m, 0,5...3% in weight solid particles chosen from elastomers with a length of 0,1...4 mm and a thickness of 0,1...0,9 ⁇ m consisting of particles of vulcanized rubber treated with esters of fatty acids with inferior alcohols and activated with UV radiations and polyethylene pulp, the particles having a thickness of 0,1..5 ⁇ m and a diameter of 0,1...4 mm or mixtures of these, 10...20% in weight filling
• the composition that can be used is the following: 35% in weight softened water, 31 % in weight propylene glycol, 2% in weight cellulose fibers, fibers having a length of 0,5...5 mm and a thickness of 1...25 ⁇ m, 0,6% in weight solid particles constituted from elastomers with a length of 0,1...4 mm and a thickness of 0,1...0,9 ⁇ m consisting of particles of vulcanized rubber treated with esters of unsaturated fatty acids with inferior alcohols and activated with UV radiations and polyethylene pulp, the particles having a thickness of 0,1...5 mm and a diameter of 0,1...4 mm, in weight ratio of 3:1 , 18*% in weight filling material based on dextrin and amorphous silica mixtures, in ratio in weight of 4:1, 0,4% thixo
• the composition has an apparent dynamic viscosity at the speed of 20 rot/min comprised between 5000 and 8000 cPs , with a pH of 7...10 , a freezing temperature of minimum -35 0 C, an evaporation temperature, in conditions of normal pressure, of 104 0 C and a density of 1 ,09... 1,25 g/cm 3 .
• Example 4 In an example of composition achievement for with/without chamber tires, where the air pressure in the precinct is between 2 bar - 6 bar, in hard conditions, the loads are of 12-15 t on the axle and the wedges frequency is high, where the perforating object dimension may reach the dimension of 20 mm a composition is constituted from 20...50% in weight softened water, 20...50% in weight propylene glycol, 1 ,5...5% in weights natural and/or synthetic fibers chosen from cellulose, ararnide, acrylic or melamine fibers, the fibers having a length of 0,5...5 mm and a thickness of 1...25 ⁇ m, 0,5...3% in weight solid particles chosen from elastomers with a length of 0,1...4 mm and a thickness of 0,1...0,9 mm consisting of particles of vulcanized rubber treated with esters of fatty acids with inferior alcohols and activated with UV radiations and polyethylene pulp, the particles having a thickness of 0,1.5 ⁇ m and a diameter of 0,1...
• the composition that can be used is the following: 3O% in weight softened water, 28,1 % in weight propylene glycol, 3% in wei ght cellulose and melaminic fibers, fibers having a length of 0,5...5 mm and a thickness of 1...25 ⁇ m, 1% in weight solid particles constituted from elastomers with a length of 0,1...4 mm and a thickness of 0,1...0,9 ⁇ m consisting of particles of vulcanized rubber treated with esters of unsaturated fatty acids with inferior alcohols and activated with UV radiations, 20% in weight filling material based on dextrin and amorphous silica mixtures, in ratio in weight of 4:1 , 0,4% thixotropic agent biopolymer based on scleroglucen, 6 % in weight
• the composition has an apparent dynamic viscosity between 5000 and 9000 cPs , with a pH of 7...10 , a freezing temperature of minimum -35 0 C, an evaporation temperature, in conditions of normal pressure, of 104 0 C and a density of 1,1... 1,3 g/cm 3 .
• the solid particles and particles are oriented to the discontinuity, case in which they are overconcentrated, forming in the end a seal, that generally has the shape of a small base cone trunk oriented to the external elastic wall in the position in which he is situated near the road, and more as it moves away from the road considering the elasticity of the wall, the shape of the seal is modified, small base becoming centre precinct oriented, this deformation continuing during the entire motion period, the formed seal not being expulsed.

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• 2004
  • 2004-10-04 RO ROA200400837A patent/RO121646B1/ro unknown
  • 2004-10-05 EP EP04816704A patent/EP1984168A1/en not_active Withdrawn
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