JP2012007050A - Method of producing puncture sealing agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a puncture sealing agent, by which: the time it takes to blend structural components of the puncture sealing agent can be shortened to thereby reduce production time; and the puncture sealing agent can be prevented from being gelated due to the aggregate of a latex particles to thereby prevent the puncture sealing agent from being deteriorated.SOLUTION: The method of producing the puncture sealing agent includes: mixing a latex having a solid content of 10 to 70 mass% with one of an antifreeze liquid and an adhesive emulsion; and thereafter mixing the resultant latex with the other thereof.

Description

  The present invention relates to a method for producing a puncture sealing agent.

  When a puncture occurs in a pneumatic tire (hereinafter simply referred to as “tire”), rubber latex, antifreeze (freezing agent) is used as a puncture sealing agent that is injected into the tire from a valve or the like and seals the puncture occurrence site from the inside. ) And those mainly composed of an adhesive are widely used. This puncture sealant is generally produced by stirring and mixing the above components, but since propylene glycol, which is suitably used as an antifreeze, has the property of absorbing moisture rapidly from the surroundings, the concentration of rubber latex particles However, the rubber latex particles are fused with each other to form an aggregate, and a phenomenon in which a part or all of the sealing agent is solidified (gelled) using the aggregate as a core is likely to occur.

  Various proposals have been made for this problem. For example, there is a method for producing a puncture sealing agent focusing on the mixing order of the components. As an example, a first mixing step of mixing an antifreezing agent and water, a second mixing step of mixing the mixed solution and the rubber latex that have passed through the first mixing step, and the second mixing step. A manufacturing method is disclosed that includes a third mixing step in which the mixed liquid and the adhesive that have passed through are mixed (see, for example, Patent Document 1). Moreover, the 1st mixing process which mixes rubber latex and water, the 2nd mixing process which mixes an antifreezing agent and an adhesive, the liquid mixture which passed through the said 1st mixing process, and the said 2nd mixing A manufacturing method is disclosed that includes a third mixing step in which the mixed liquid that has undergone the step is mixed and a filtration step in which filtration is performed after the third mixing step (see, for example, Patent Document 2).

  In addition, a method for producing a puncture sealing agent focusing on the mixing work of each component is also disclosed. As such, the antifreeze agent while stirring the mixed solution of the rubber latex and the adhesive contained in the cylindrical container by the rotation of the stirring blade rotating at the tip speed of 1.0 to 10.0 m / sec. Can be injected into the surface of the mixed solution at a rate of 0.01 to 0.1 liter / min per inlet from a plurality of inlets (see, for example, Patent Document 3). In this manufacturing method, it is preferable that stirring is continued for a certain period of time (for example, 5 minutes or more) even after the injection of the cryoprotectant (ethylene glycol) is completed in the antifreeze injection stirring step. This is because, after completion of the injection of ethylene glycol, the stirring of the sealant stock solution is continued for a certain period of time, so that the aggregation and growth of minute latex agglomerates formed in the sealant stock solution during stirring can be promoted. This is because the latex agglomerates can be easily removed by filtration rather than the latex agglomerates present in the agent stock solution in a minute state.

WO2008 / 032765 JP 2008-069253 A Japanese Patent No. 4188623

  However, the mixing order of the components in the method for producing the puncture sealing agent of Patent Document 1 has a problem that it takes time to mix. Moreover, in the manufacturing method of the puncture sealing agent of patent document 2, it is necessary to provide two stirring tanks for the 1st mixing process and for the 2nd mixing process in the upstream part of a manufacturing line, and also an antifreezing agent and adhesion Since mixing with the agent took time, there was much room for improvement in terms of productivity.

  As for Patent Document 3, the inventors conducted an experiment for confirming the effect of the production method of the puncture sealant, etc. After stirring the sealant stock solution for a certain period of time, the sealant stock solution was filtered. As a result, it was found that latex agglomerates could not be sufficiently removed from the sealant stock solution and gelation of the puncture sealant produced from this sealant stock solution could not be completely prevented.

  The present invention has been made in view of the above circumstances, and shortens the time required for mixing the constituents of the puncture sealing agent, thereby reducing the production time and the puncture sealing agent resulting from the agglomeration of latex particles. It aims at providing the manufacturing method of a puncture sealing agent which can prevent gelatinization effectively and can suppress deterioration of a puncture sealant, and makes it a subject to achieve this objective.

<1> The present invention is a method for producing a puncture sealing agent comprising a step of mixing a latex having a solid content of 10% by mass or more and 70% by mass or less with one of an antifreeze solution and an adhesive emulsion, and further mixing the other. is there.

  According to the invention described in <1>, it is possible to effectively prevent gelation of the sealing agent due to latex agglomerates while reducing the time required for mixing the constituent components of the puncture sealing agent.

<2> The present invention is the method for producing a puncture sealing agent according to <1>, wherein the step is a step of further mixing the adhesive emulsion after mixing the latex and the antifreeze liquid.

  According to the invention described in <2>, aggregation of latex particles can be more effectively prevented, and gelation of the puncture sealing agent due to latex aggregates is suppressed.

<3> In the present invention, when the antifreeze liquid is mixed, the stirring speed of the latex or the mixed liquid of the latex and the adhesive emulsion is 50 rpm or more and 500 rpm or less, and the dropping speed of the antifreeze liquid is 0.5 kg / min or more. It is a manufacturing method of the puncture sealing agent as described in <1> or <2> which is 500 kg / min or less.

  According to the invention described in <3>, it is possible to effectively suppress the concentration of the latex particles from being locally increased around the antifreeze solution, and to more effectively prevent aggregation of the latex particles.

  According to the present invention, the production time is shortened by shortening the time required for mixing the constituents of the puncture sealant, and the puncture sealant is effectively prevented from gelation due to the agglomerates of latex particles. The manufacturing method of the puncture sealing agent which can suppress deterioration of a sealing agent can be provided.

It is the schematic which shows an example of the sealing pump-up apparatus used in order to fill a tire with a puncture sealing agent. It is the schematic which shows the other example of the sealing and pump-up apparatus used in order to fill a tire with a puncture sealing agent, (A) is the schematic which shows the usage example of the bottle which is a container for a puncture sealing agent. (B) is the schematic which shows the usage example of an air compressor.

  The method for producing the puncture sealing agent of the present invention comprises a latex having a solid content of 10% by mass to 70% by mass (hereinafter sometimes referred to as “latex of the present invention” or simply “latex”), an antifreeze and an adhesive. After mixing with one of the emulsions, there is a step of mixing the other. Mainly by mixing latex prepared in a predetermined solid content, antifreeze and adhesive emulsion in order so that the latex does not aggregate when mixed with antifreeze, and thus gelation after mixing does not occur. , While reducing the total mixing time, it is possible to keep the latex, which is important for developing sealability, stable in an aqueous medium and effectively prevent the gelling of the sealing agent due to latex agglomerates. It becomes.

  In the method for producing the puncture sealing agent of the present invention, either the antifreeze solution or the adhesive emulsion may be mixed with the latex first, but the latex and the antifreeze solution are mixed first, and then the latex and the antifreeze solution are mixed. It is preferable to further mix an adhesive emulsion with the mixed solution. By first mixing the latex and antifreeze solution, it is possible to more effectively prevent the latex particles from agglomerating, and the gelation of the puncture sealant due to the latex agglomerates is suppressed. Increased stability.

  In addition, when mixing the antifreeze liquid, it is necessary to adjust the feeding speed of the antifreeze liquid so that the latex particles do not aggregate. However, the antifreeze liquid is mixed with the latex rather than the antifreeze liquid mixed with the mixed liquid of the latex and the adhesive emulsion. In the case of mixing the antifreeze liquid, the input speed of the antifreeze liquid can be increased, so that the time required for mixing the antifreeze liquid can be shortened, and as a result, the production time of the puncture sealing agent can be shortened.

  In the method for producing the puncture sealing agent of the present invention, the method of mixing the latex and the antifreeze liquid is not particularly limited, but it is preferable to add the antifreeze liquid dropwise thereto while stirring the latex. By doing in this way, it is suppressed that the density | concentration of a latex particle becomes high locally around an antifreeze liquid, and aggregation of a latex particle can be prevented effectively. From the viewpoint of shortening the time required for mixing and effectively preventing aggregation of latex particles, the stirring speed of the latex is preferably 50 rpm to 500 rpm. The dropping rate of the antifreeze liquid can be set according to the solid content of the latex, the stirring speed, and other mixing conditions. For example, in the above stirring speed, 0.5 kg / min to 500 kg / min is preferable. From the viewpoint of effectively preventing agglomeration, it is more preferably 0.5 kg / min to 100 kg / min.

  In the above, the stirring speed of the latex is preferably increased as the liquid depth [mm] of the mixed solution increases from the viewpoint of effectively preventing aggregation of latex particles and the viewpoint of productivity. The amount of change in the stirring speed is preferably 0.1 rpm / mm to 6.0 rpm / mm, and more preferably 0.2 rpm / mm to 1.5 rpm / mm. The amount of change in the stirring speed is preferably constant.

  The mixing of the latex and the pressure-sensitive adhesive emulsion can also be carried out in the same manner as the mixing method of the latex and the antifreeze solution, and the preferred embodiment is also the same. Furthermore, the mixture with the adhesive emulsion or antifreeze mixed later can be carried out in the same manner as the above-described method of mixing the latex and antifreeze, and the preferred embodiment is also the same.

<Latex>
The latex of the present invention is a suspension in which a polymer is dispersed in an aqueous medium and has a solid content of 10% by mass to 70% by mass. The latex may be prepared so as to have a solid content of 10% by mass to 70% by mass by newly manufacturing or diluting in accordance with the production of the puncture sealing agent. % To 70% by mass may be prepared. When the latex of the present invention is obtained by mixing a latex having a solid content exceeding a predetermined amount and water, for example, the latex can be obtained by mixing water while stirring the latex.

  Here, the solid content of the latex can be determined as follows. First, 10 g of latex is allowed to stand at 140 ° C. for 4 hours. It can be determined by measuring the mass of the residue after standing and dividing the mass of the residual by the mass of latex (mass of residual amount / mass of latex before leaving).

  The latex of the present invention has a solid content of 10% by mass to 70% by mass. When the solid content of the latex is more than 70% by mass, when mixed with the antifreeze liquid, the concentration of local latex particles around the antifreeze liquid increases so as to cause aggregation of the latex, and the latex becomes stable in an aqueous system. I can't keep it. Further, when the solid content is 70% by mass or less, the polymer is easily stabilized in the aqueous medium, and the sedimentation of the solid content can be suppressed, so that the storage stability of the latex is excellent. If the solid content is less than 10% by mass, it cannot be expected that the puncture sealant exhibits sealing properties.

  The solid content of the latex of the present invention is preferably from 20% by mass from the viewpoint of improving the sealing properties when used as a puncture sealant and effectively preventing aggregation of latex particles when mixed with antifreeze. It is 70 mass%, More preferably, it is 25 mass%-50 mass%.

  Here, the type of latex is not particularly limited, and for example, natural rubber (NR) latex, synthetic rubber latex, or synthetic resin latex can be appropriately selected and used.

  Examples of the synthetic rubber latex include SBR (styrene butadiene rubber) latex, NBR (nitrile rubber) latex, MBR (acrylic rubber) latex, BR (polybutadiene rubber) latex, IIR (butyl rubber) latex, CR latex, IR latex, And polysulfide rubber latex.

  Examples of the synthetic resin latex include carboxy-modified NBR latex, carboxy-modified SBR latex, acrylic ester latex, styrene / butadiene / resin latex, vinyl acetate latex, polyvinyl acetate latex, vinyl chloride latex, polyvinyl chloride latex, and vinylidene chloride latex. , Polyvinylidene chloride latex, polystyrene latex and the like.

  Among the above, in consideration of corrosiveness to tires and the like, it is more preferable to use synthetic rubber latex or synthetic resin latex. SBR latex, NBR latex, MBR latex, BR latex, carboxyl-modified NBR latex, and carboxyl-modified SBR latex It is more preferable to use one or more selected from the group consisting of:

Latex may be used alone or in combination of two or more.
The content of the latex is preferably 1% by mass to 70% by mass, more preferably 5% by mass to 50% by mass, and more preferably 5% by mass to 25% by mass with respect to the total mass of the puncture sealing agent. More preferably.

<Antifreeze>
The antifreeze liquid is not particularly limited as long as it has a function of preventing the puncture sealing agent from freezing when the puncture sealing agent is used in a cold region.
For example, monohydric alcohol and dihydric alcohol can be used, and examples thereof include ethanol, 1-propanol, ethylene glycol (EG), and propylene glycol (PG). The alcohol may be linear, branched, or cyclic. Among them, propylene glycol (PG) is preferably used from the viewpoint of safety, and monovalent having 1 to 5 carbon atoms from the viewpoint of reducing the viscosity of the puncture sealing agent. It is preferable to use the alcohol.

  The content of the antifreeze is not particularly limited, but is preferably 5% by mass to 90% by mass with respect to the total mass of the puncture sealing agent from the viewpoint of antifreezing property at low temperatures. More preferably, it is 20 mass%-60 mass%.

<Adhesive emulsion>
The pressure-sensitive adhesive emulsion is obtained by emulsifying a pressure-sensitive adhesive using a surfactant. The pressure-sensitive adhesive mainly improves the adhesive strength of the synthetic rubber or natural rubber, which is a solid content of latex, to the tire, and is not particularly limited as long as it does not impair the effects of the present invention. It can be used suitably.

  Examples of the resin adhesive include natural resins, modified rosins and derivatives of modified rosins, terpene resins and terpene modified products, aliphatic hydrocarbon resins, cyclopentadiene resins; aromatic petroleum resins, phenolic resins, Examples thereof include alkylphenol acetylene resins, styrene resins, xylene resins, coumarone-indene resins, and vinyl toluene-α methyl styrene copolymers.

Examples of the natural resin include rosin and dammar.
Examples of the modified rosin and modified rosin derivatives include polymerized rosin (eg, rosin acid ester resin), partially hydrogenated rosin, and the like.
Examples of the terpene resin and the modified terpene include terpene phenol resins such as pinene, α-pinene phenol resin, dipentene phenol resin, terpene bisphenol resin, and hydrogenated products thereof.
Examples of the aliphatic hydrocarbon resin include olefins and olefin polymers.

  Moreover, an acrylic adhesive, a water-soluble adhesive, etc. can also be used.

  Among these, it is preferable to use a terpene phenol resin or a rosin acid ester resin from the viewpoint that the latex is difficult to coagulate and has excellent adhesion between the latex solid and the tire.

  As the emulsifier, a known surfactant (preferably a nonionic surfactant) is used, and a terpene resin such as a rosin ester resin or a terpene phenol resin or a butyl rubber material such as polyisobutylene is used as a resin component. Can be used.

  It is preferable to use an adhesive emulsion that is compatible with latex in consideration of miscibility with latex and improvement in puncture sealing. Here, the fact that the pressure sensitive adhesive emulsion is “compatible” with the latex means that the pressure sensitive adhesive emulsion does not coagulate the latex in any way, and the pressure sensitive adhesive emulsion improves the adhesion of the latex to the tire. It is used as a thing. For example, a resin can be used by being added to an elastomer as a rubber film tackifier.

  The content of the adhesive emulsion in the puncture sealing agent is preferably 1% by mass to 15% by mass, more preferably 2% by mass to 12% by mass, with respect to the total mass of the puncture sealing agent, More preferably, it is 3 mass%-9 mass%. By setting the content to 1% by mass to 15% by mass, a practical and good sealing property can be exhibited.

<Other ingredients>
The puncture sealing agent of the present invention can further contain other components such as short fibers and surfactants as long as the effects of the puncture sealing agent of the present invention are not impaired.
Hereinafter, other components will be described.

(Short fiber)
The puncture sealing agent of the present invention may contain short fibers instead of or in addition to the pressure-sensitive adhesive. The short fibers enter holes and holes (defects) generated in the tire by puncture and cause clogging, and serve to close these holes and holes quickly and reliably.

The short fiber content is preferably 0.1% by mass to 5% by mass with respect to the total mass of the puncture sealing agent. If it is 0.1% by mass or more, the sealing property due to the addition of the short fibers can be sufficiently exhibited, and if it is 5% by mass or less, the entanglement of the short fibers can be prevented and the viscosity hardly increases. The ease of injection of the puncture sealing agent is improved, and the role of the puncture sealing agent described above is sufficiently exerted.
The content of the short fiber is preferably 0.3% by mass to 4% by mass, and more preferably 0.5% by mass to 3% by mass with respect to the total mass of the puncture sealing agent.

  In order to sufficiently exert the above-described role for the puncture sealant, various designs need to be made for the short fibers. Therefore, the specific gravity (S), length (L), diameter (D), and ratio of length to diameter (L / D) of the short fibers are preferably set in the following ranges, respectively.

(1) Specific gravity (S): 0.8 ≦ S ≦ 1.4 (more preferably 0.9 ≦ S ≦ 1.3, and still more preferably 1.0 ≦ S ≦ 1.2). When the specific gravity is 0.8 or more and 1.4 or less, short fibers do not float or sink, and long-term dispersion stability is improved.

(2) Length (L): 0.05 ≦ L ≦ 10 mm (more preferably 0.08 ≦ L ≦ 8 mm, still more preferably 0.1 ≦ L ≦ 6 mm). When the length is 0.05 mm or more, the effect of improving the sealing property by causing short fibers to clog defective portions due to punctures is satisfactorily exhibited. When the length is 10 mm or less, the relative number of short fibers increases. Therefore, the sealing property is good.

(3) Diameter (D): 1 ≦ D ≦ 100 μm (more preferably 3 ≦ D ≦ 80 μm, still more preferably 5 ≦ D ≦ 50 μm). When the diameter (thickness) is 1 μm or more, the role of short fibers that improve the sealing performance by causing the above-mentioned clogging is satisfactorily exhibited. Is good.

(4) Ratio of length to diameter (L / D): 5 ≦ L / D ≦ 2000 (more preferably 20 ≦ L / D ≦ 1600, more preferably 50 ≦ L / D ≦ 1200, particularly preferably 100 ≦ L / D ≦ 300). When L / D is 5 or more, the role of short fibers that cause the above-mentioned clogging and improve sealability is satisfactorily exhibited. When L / D is 2000 or less, lumps due to entanglement of short fibers are less likely to occur. Easy injection.

  In addition, short fibers made of one material can be used in a certain shape, but short fibers made of a plurality of materials can be used in various shapes within the range described above.

  The short fiber is not particularly limited in its material, but is preferably composed of polyester, polyethylene, nylon, polypropylene, or a composite of two or more thereof, polyethylene, nylon, polypropylene, and a composite of two or more of these. It is more preferable that it consists of either. By using such short fibers, better separation stability can be obtained.

It is preferable that the short fiber is treated with a solvent such as a higher alcohol derivative and / or a betaine activator in the whole amount or a part thereof (preferably the whole amount). By this treatment, the solvent acts as an active agent, and the dispersibility of the short fibers can be improved.
The treatment may be performed before or after inclusion in the puncture sealant. The treatment can be carried out by impregnating the short fiber with the solvent or spraying the solvent. As the higher alcohol derivative, polyglycol polyester is suitable.

  The amount of the solvent added (the amount absorbed by the short fiber by the above treatment) is preferably 0.2% by mass to 20% by mass, and 0.5% by mass to 10% by mass of the short fiber mass. Is more preferable, and it is further more preferable that it is 1 mass%-6 mass%. If it is the said range, sufficient dispersion | distribution effect of a short fiber will be acquired, the said process is favorable, and the improvement of an effect can be anticipated.

(Filler)
Also, one or more fillers may be mixed with the puncture sealant so that it can be quickly sealed and reliably sealed even with large holes. Examples of the stable filler include silicic acid, chalk, carbon black, synthetic resin reinforced with glass fiber, polystyrene particles, powder rubber obtained by grinding vulcanized products such as tires, sawdust, moslaver particles, foam particles for cut flowers Etc. can be adopted. Among these, particularly preferred fillers are rubber powder bonded with silicic acid, and synthetic resin reinforced with glass fiber.

  The filler can be added directly to the puncture sealant. However, as long as the filler has a size that makes it difficult or impossible to guide the puncture sealant through the valve without changing the valve size, these fillers generally rim the tire. Sometimes it is introduced into the inside of the tire, and when a puncture occurs in the tire, a puncture sealing agent is injected to achieve sealing.

  The filler is preferably added to the puncture sealant at about 20 g / liter to 200 g / liter, more preferably 60 g / liter to 100 g / liter, or disposed inside the tire in the tire rim set.

(water)
The puncture sealant of the present invention can contain water.
Water can be used as a dispersion medium when the pressure-sensitive adhesive is used as a pressure-sensitive adhesive emulsion, but can also be used for diluting the puncture sealing agent.

(Other additives)
The puncture sealant of the present invention may be added with a normal dispersant, an emulsifier, a foam stabilizer, a pH adjuster such as caustic soda, and a liquid resin emulsion may be used if necessary.

<Other processes>
In the present invention, after mixing the latex with the antifreeze liquid and the adhesive emulsion, a filtration step and an agglomerate growth step may be provided as necessary. Hereinafter, each step will be described.

(Filtering process)
A filtration process is a process of filtering the liquid mixture containing at least latex, an antifreeze, and an adhesive emulsion as needed. As a filtration method, a known method can be employed. Depending on the production conditions, after mixing the above-mentioned components, gelation due to aggregation of latex particles may proceed to produce fine particle aggregates. If the agglomerates are allowed to stand, gelation may proceed further with this as a nucleus. Therefore, it is preferable to remove the fine particle aggregates serving as nuclei by the filtration step, and effectively prevent gelation of the puncture sealant resulting from the latex agglomerates. As a result, the storage stability of the puncture sealing agent can also be improved.

  As a filter member of a filter used for filtration, it is preferable to use a metal mesh filter formed in a wire mesh shape. In this case, the number of meshes is preferably 50 mesh (mesh opening diameter is about 300 μm) to 400 mesh (mesh opening diameter is about 30 μm). As a material of the mesh filter, a metal material having high corrosion resistance such as stainless steel and aluminum alloy can be suitably used.

  Further, as the filter member, a porous filter having a large number of fine openings having an opening diameter substantially the same as the mesh of a mesh filter of 50 mesh to 400 mesh may be used, and a mesh filter or a porous filter may be used. A laminated filter that is laminated may be used.

(Agglomerate growth process)
Prior to the filtration step, an agglomerate growth step is preferably provided. In this agglomerate growth step, the stock solution of the sealing agent prepared by mixing the constituent components is held (standing) in the container without stirring for at least 24 hours or more, preferably 48 hours or more. . The lower limit of the standing time can be appropriately changed in the range of 24 hours to 48 hours according to the number of meshes of the mesh filter used in the filtration step.

  In addition, although the upper limit of the standing time is not particularly limited, consideration is given to the restriction of the process time (tact time) when manufacturing the puncture sealing agent, the limit of the stock amount for stocking the manufactured puncture sealing agent, etc. In addition, since the amount of water contained in the puncture sealant gradually changes due to evaporation or moisture absorption depending on the storage environment, the upper limit of the standing time is set to 480 hours or less considering the change in the amount of moisture during storage. It is preferable to set.

<Punk sealing agent>
If the agglomeration of latex particles can be effectively prevented during production of the puncture sealant, gelation of the puncture sealant due to the latex agglomerates will be suppressed, so the storage stability of the puncture sealant will increase and deterioration will occur. It is suppressed over a long period of time, and the life of the puncture sealant is extended.

  The puncture sealant of the present invention is produced by mixing the above-described materials in the order described. The production, storage and filling of the puncture sealant is preferably performed in an atmosphere of nitrogen or a rare gas in order to avoid oxidation and the like. Done.

(Solid content of puncture sealant)
The total solid content in the puncture sealing agent of the present invention is preferably 5 to 70% by mass with respect to the total mass of the puncture sealing agent. If the total solid content is 5% by mass or more with respect to the total mass of the puncture sealing agent, it is possible to ensure sufficient sealing performance. Moreover, if it is 70 mass% or less, characteristics other than a sealing property can fully be ensured.
A more preferable upper limit of the total solid content within the above range is 60% by mass, more preferably 50% by mass, and particularly preferably 40% by mass. Further, a more preferable lower limit of the total solid content within the above range is 8% by mass.

  The “total solid content” can be determined as follows. First, 10 g of the puncture sealant is left at 140 ° C. for 4 hours. It can be determined by measuring the mass of the residue after standing and dividing the mass of the residual by the mass of the puncture sealing agent (mass of residual amount / mass of the puncture sealing agent before leaving).

(Viscosity of puncture sealant)
The viscosity of the puncture sealant is 3 mPa · s to 20,000 mPa · s under the conditions assumed as actual use conditions (at least in the range of 60 ° C. to −60 ° C. before filling the tire). Is more preferably 5 mPa · s to 4,500 mPa · s, further preferably 8 mPa · s to 3,000 mPa · s, particularly preferably 10 to 3,000 mPa · s, Most preferably, it is ˜1,500 mPa · s.

  If the viscosity of the puncture sealant is 3 mPa · s or more, liquid leakage at the time of injection into the valve can be prevented. If it is 20,000 mPa · s or less, the resistance at the time of injection can be suppressed, so that the ease of injection can be prevented and the spread to the tire inner surface can be sufficiently increased. Sealability is obtained.

The puncture sealant of the present invention can further lower the freezing point by increasing the content of monohydric alcohol, and can be suitably used with low viscosity even in extremely cold regions such as −40 ° C. or lower. The viscosity of the puncture sealant at −40 ° C. is preferably 3 mPa · s to 5,000 mPa · s, more preferably 10 mPa · s to 3,000 mPa · s, and more preferably 10 mPa · s to 2,000 mPa · s. Particularly preferred is s.
The viscosity of the puncture sealant can be measured with a B-type viscometer or the like.

(How to repair punctures with puncture sealants)
As a method for repairing puncture with the puncture sealing agent of the present invention, a known method can be applied. That is, first, a container filled with a puncture sealing agent is connected to the valve opening of the tire, and an appropriate amount is injected. Thereafter, the tire may be rotated so that the puncture sealing agent spreads on the inner surface of the tire and seals the puncture holes.

  Such a puncture sealant itself can be introduced into the inside of a tire by using various pump-up devices, for example, a spray can containing a propane / butane mixed gas as a fuel gas, and is shown in FIG. The pump-up device 20 can be used more preferably.

  In the pump-up device 20 shown in FIG. 1, a small air compressor 1 is used as the pressure source. This air compressor 1 is connected to a gas introduction part 3 of a pressure vessel 4 via a hose 2. The gas introduction part 3 is formed as a riser tube that can be closed by a stopper valve 5 and extends to the liquid level of the puncture sealing agent 6 accommodated in the pressure resistant container 4.

  The pressure vessel 4 has an outlet valve 7 for taking out the puncture sealing agent 6. One end of a hose 8 is connected to the outlet valve 7, and the other end of the hose 8 is connected to a tire valve 10. A screw adapter 9 to be screwed is attached.

The pressure vessel 4 has a filling stub 12 and a jacket 11 filled with water. The filling stub 12 can be filled with calcium chloride as a heating source as required. When the puncture sealant 6 is frozen at a low temperature, the puncture sealant 6 is heated to an available temperature by the heat released by the hydration action of the heating source.
An electric cable 13 is connected to the air compressor 1, and its plug 14 is inserted into a cigarette lighter, for example.

  When puncture occurs in the tire, the screw adapter 9 is screwed to the tire valve 10, the air compressor 1 is connected to the cigarette lighter, and the plug valve 5 is opened in the gas introduction part 3 of the pressure vessel 4. The compressed air introduced from the air compressor 1 into the pressure vessel 4 through the gas introduction part 3 pushes out the puncture sealing agent 6 from the outlet valve 7 and introduces the tire valve 10 into the inside of the tire. Thereafter, air is refilled into the tire, causing the tire to inflate at a specific internal pressure. When this is finished, the screw adapter 9 is removed from the tire valve 10 and the air compressor 1 is stopped. Immediately after this, after preliminarily traveling for a certain distance and sealing the puncture hole while spraying the puncture sealing agent 6 inside the tire, the pump-up device 20 is connected again and the tire is pumped again to the required internal pressure. Up.

  Moreover, the puncture sealing agent of this invention can be used more preferably also by the pump up apparatus shown by FIG. 2 (A) and (B). In the pump-up device shown in FIGS. 2A and 2B, the same reference numerals are given to the same parts as those in the pump-up device 20 shown in FIG.

  This pump-up device includes a resin bottle 22 that is a container for the puncture sealing agent 6 shown in FIG. 2 (A) and an air compressor 1 as a pressure source shown in FIG. 2 (B). . The bottle 22 contains the puncture sealing agent 6 necessary for one puncture repair. A hose 24 having an adapter 26 disposed at the tip is connected to the bottle 22. An adapter 9 is also arranged at the tip of the hose 2 connected to the air compressor 1. However, as long as the hose 24 of the bottle 22 can be directly connected to the tire valve 10, the adapter 26 may be omitted.

  When the puncture occurs, the adapter 26 of the bottle 22 is screwed to the tire valve 10. Thereby, it communicates in the tire through the hose 24 and the adapter 26. In this state, as shown by a two-dot chain line (imaginary line) in FIG. 2A, the operator squeezes the bottle 22 and squeezes out the puncture sealing agent 6 from the bottle 22 to pass through the hose 24. Puncture sealant 6 is injected into the tire.

  When the injection of the puncture sealing agent 6 from the bottle 22 into the tire is completed, the operator removes the adapter 22 from the tire valve 10 and separates the bottle 22 from the tire.

  Next, the operator screws the adapter 9 of the air compressor 1 to the tire valve 10 and causes the air compressor 1 to communicate with the tire through the adapter 9 and the hose 2. In this state, the operator operates the air compressor 1 to refill the tire with pressurized air, and inflates the tire with a specific internal pressure. When this is finished, the operator removes the adapter 9 from the tire valve 10 and stops the air compressor 1. Immediately after this, after preliminarily traveling for a certain distance and sealing the puncture hole while spraying the puncture sealing agent 6 inside the tire, the operator requests the tire by reconnecting the air compressor 1 of the pump-up device. Pump up again to the internal pressure.

  The puncture sealant of the present invention can be applied to puncture repair of various pneumatic tires. Examples thereof include automobile tires, motorcycle tires, unicycle tires, wheelchair tires, vehicle tires used for farmland work and garden work, and the like.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist thereof. “Part” is based on mass.

Example 1
To 40 parts of SBR latex (solid content 40% by mass), 5 parts of water was added and stirred to obtain a latex having a solid content of 36% by mass. Subsequently, 45 parts of propylene glycol was added dropwise at a dropping rate of 2 kg / min and mixed while stirring the latex while increasing the stirring rate in units of 5 rpm / mm within the range of 100 to 300 rpm. Next, 10 parts of the rosin acid ester emulsion was added dropwise and mixed while stirring the resulting mixture. After leaving still for 36 hours, it filtered using a 200 mesh filter, and manufactured the puncture sealing agent.

(Example 2)
To 40 parts of SBR latex (solid content 40% by mass), 5 parts of water was added and stirred to obtain a latex having a solid content of 36% by mass. Subsequently, 10 parts of the rosin ester emulsion was added dropwise and mixed while stirring the latex. Next, 45 parts of propylene glycol was added dropwise at a dropping speed of 2 kg / min while mixing while stirring the resulting mixed liquid while increasing the stirring speed in units of 5 rpm / mm in the range of 100 to 300 rpm. After leaving still for 36 hours, it filtered using a 200 mesh filter, and manufactured the puncture sealing agent.

(Example 3)
In Example 1, puncture sealing was performed in the same manner as in Example 1 except that 5 parts of water was added to 40 parts of SBR latex (solid content: 17% by mass) and stirred to obtain a latex having a solid content of 15% by mass. An agent was produced.

Example 4
In Example 1, puncture sealing was performed in the same manner as in Example 1 except that 40 parts of SBR latex (solid content: 73% by mass) was charged with 5 parts of water and stirred to obtain a latex having a solid content of 65% by mass. An agent was produced.

(Comparative Example 1)
To 40 parts of SBR latex (solid content 40% by mass), 5 parts of water was added and stirred to obtain a latex having a solid content of 36% by mass. At the same time, 10 parts of a rosin ester emulsion was added to 45 parts of propylene glycol and stirred to obtain a mixed solution. Next, while stirring the latex while increasing the stirring speed in increments of 5 rpm / mm within the range of 100 to 300 rpm, the mixed solution of propylene glycol and rosin ester emulsion is dropped at a dropping speed of 2 kg / min and mixed. did. After leaving still for 36 hours, it filtered using a 200 mesh filter, and manufactured the puncture sealing agent.

(Comparative Example 2)
In Example 1, puncture sealing was performed in the same manner as in Example 1 except that 5 parts of water was added to 40 parts of SBR latex (solid content: 6% by mass) and stirred to obtain a latex having a solid content of 5% by mass. An agent was produced.

<Evaluation>
(Mixing time)
The time required for mixing 1 kg of a mixed solution of SBR latex, water, propylene glycol and rosin ester emulsion was measured. For Examples 1 to 4 and Comparative Example 2, the mixing time was from the time when water was started to be introduced into the SBR latex to the time when the standing was started. For Comparative Example 1, the mixing time was from the time when the rosin acid ester emulsion was started to be added to propylene glycol (at the same time when water was started to be added to the SBR latex) until the start of standing. The results are shown in Table 1 below.

(Seal performance)
The degree of deterioration of the puncture sealant over time can be evaluated by a running test using tires with holes. At that time, a puncture sealant stored for a certain period in an oven at 90 ° C. can be used as an aged model. For example, storage for 25 days corresponds to the passage of 8 years after market.

  The puncture sealants obtained in Examples 1 to 4 and Comparative Examples 1 to 2 were stored in an oven at 90 ° C. for 12 days or 25 days. A drill hole of φ2.6 mm was drilled in a 195 / 65R15 tire, 450 ml of a puncture sealant after storage was injected, the tire pressure was increased to 0.2 MPa, and the tire was mounted on a car. Thereafter, the vehicle was driven at 60 km / h or less. The one that the internal pressure drop is 0 and completely hardened within 3 km running ◎ The one that the internal pressure drop is 0 and completely hardened within 5 km running ○ The one that the internal pressure drop is 0 and completely hardened within 10 km running △ The case where the internal pressure decreased and the air leaked from the repaired part was judged as x. The results are shown in Table 1 below.

  Since the time required for mixing the puncture sealants of the examples is extremely short compared to the comparative example, it is clear that the production time of the puncture sealants can be shortened and the production efficiency is excellent. In addition, since the puncture sealant of the example had been sealed within 5 km even after storage for 25 days, it is clear that the deterioration of the puncture sealant was suppressed.

3 Gas introduction part 4 Pressure-resistant vessel 6 Sealing agent 7 Outlet valve 20 Pump-up device

Claims (3)

  A method for producing a puncture sealing agent, comprising mixing a latex having a solid content of 10% by mass or more and 70% by mass or less with one of an antifreeze and an adhesive emulsion, and further mixing the other.   The method for producing a puncture sealing agent according to claim 1, wherein the step is a step of further mixing the adhesive emulsion after mixing the latex and the antifreeze liquid.   When mixing the antifreeze liquid, the stirring speed of the latex or the mixed liquid of the latex and the adhesive emulsion is 50 rpm or more and 500 rpm or less, and the dropping speed of the antifreeze liquid is 0.5 kg / min or more and 500 kg / min or less. The manufacturing method of the puncture sealing agent of Claim 1 or Claim 2.