JP2010260904A - Puncture sealing agent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a puncture sealing agent having good sealing properties while retaining good ready injectability and spreadability in a tire. <P>SOLUTION: The puncture sealing agent comprises at least rubber particles and an adhesive agent and has a solid content of 5-19 mass% and a ratio of the content of the adhesive agent to that of the rubber particle of 9.8-100 mass%. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a puncture sealing agent used when sealing a punctured tire.

  Various puncture sealing agents are known as repair agents for sealing the occurrence of puncture. In order to fill the internal pressure so that such a puncture sealing agent can be guided into the inside of the tire and run, a device conventionally equipped with a pressure-resistant container containing a puncture sealing agent containing a liquefied gas as a pressure source, such as a spray can Is used. As the liquefied gas, a propane / butane mixed gas is mainly used, and rarely a chlorofluorocarbon is also used. One end of a hose is connected to the spray can by an outlet valve, and a screw adapter for a tire valve is attached to the other end of the hose.

  When puncture occurs in the tire, the puncture sealant is blown out of the spray can through the tire valve and into the tire, and the tire pressure is restored by the fuel gas at different levels depending on the amount of gas leakage. Filled. At this time, although depending on the degree of damage, the tire travels a distance of several kilometers while spraying a puncture sealant therein to seal the damage.

  In another apparatus, the puncture sealant is housed in a compression flask connected via an adapter to a tire valve from which a valve insert has been previously extracted. The puncture sealant is blown into the tire by the compression action of the flask. After insertion of the valve insert, the tire is reinflated to a specific internal pressure with the aid of a carbon dioxide cartridge.

By the way, the puncture sealant has (1) sealability (performance to seal the puncture hole), (2) ease of injection (easy to inject the puncture sealant from a valve, etc.) and (3) spreadability in the tire. (The puncture sealing agent injected into the tire is likely to spread).
However, the performance of (1) and the performances of (2) and (3) are in a trade-off relationship. (1) There is a method of increasing the solid content in order to improve the sealing property. However, when the solid content is increased, the viscosity increases, and (2) ease of pouring and (3) spreadability in the tire decreases. In particular, since the increase in viscosity becomes remarkable in a low temperature environment, there is a problem that a large amount of a puncture sealing agent is required to spread the tire. On the other hand, when the solid content is decreased to satisfy the performances (2) and (3), there is a problem that the sealing property is lowered.

In order to satisfy these performances, a puncture sealing agent in which the gelation rate in the Malone mechanical stability test is adjusted has been proposed (see, for example, Patent Document 1). Moreover, the puncture sealing agent which is going to satisfy | fill the said performance by selecting the material of rubber latex, a short fiber, or an adhesive agent is proposed (for example, refer patent document 2).
However, there is still room for further improvement in any case, and a puncture sealing agent that satisfies the above performances (1) to (3) has been demanded.

JP 2006-152239 A International Publication No. 04/048493 Pamphlet

  The present invention has been made in view of the above-described conventional problems, and an object thereof is to achieve the following object. That is, an object of the present invention is to provide a puncture sealing agent having good sealing properties while maintaining good ease of pouring and spreading in a tire.

As a result of intensive studies to achieve the above object, the present inventors have found that the above-described problems can be achieved by the present invention described below.
That is, the present invention
<1> Contains at least rubber particles and an adhesive, has a solid content of 5% by mass to 19% by mass, and a content ratio of the adhesive to the rubber particles is 9.8% by mass to 100% by mass. This is a puncture sealing agent.
<2> As the rubber particles, SBR (styrene butadiene rubber), NBR (acrylonitrile butadiene rubber), MBR (acrylic rubber), BR (polybutadiene rubber), IIR (butyl rubber), CR (chloroprene rubber), IR (isoprene rubber) And the puncture sealing agent according to <1>, wherein at least one selected from polysulfide rubber is used.
<3> The puncture sealing agent according to <1> or <2>, wherein at least one selected from a rosin ester resin, a terpene resin, and a butyl rubber-based material is used as the adhesive.

  ADVANTAGE OF THE INVENTION According to this invention, the puncture sealing agent which has favorable sealing property can be provided, maintaining favorable injection | pouring ease and the expansibility in a tire.

It is the schematic which shows an example of the pump up apparatus which accommodates the puncture sealing agent which concerns on this invention.

Hereinafter, the present invention will be described in detail.
<Punk sealing agent>
The puncture sealing agent of the present invention contains at least rubber particles and an adhesive, has a solid content of 5% by mass to 19% by mass, and the content ratio of the adhesive to the rubber particles is 9.8% by mass to It is 100 mass%.

  The puncture sealant is required to have (1) sealing properties, (2) ease of pouring, and (3) spreadability within the tire. The performances of (1) and (2) and (3) Are in a trade-off relationship. (1) There is a method of increasing the solid content in order to improve the sealing property. However, when the solid content is increased, the viscosity is increased, and (2) ease of injection and (3) spreadability in the tire are decreased. In particular, since the increase in viscosity becomes remarkable in a low temperature environment, there is a problem that a large amount of a puncture sealing agent is required to spread the tire. On the other hand, when the solid content is decreased to satisfy the performances (2) and (3), there is a problem that the sealing property is lowered.

  However, according to the puncture sealing agent of the present invention, the increase in viscosity is suppressed by controlling the solid content ratio within the above range, and (2) ease of pouring and (3) expansibility in the tire are good. Retained. Furthermore, the sealing performance was improved by controlling the content ratio of the adhesive to the rubber particles within the above range. As a result, while maintaining sufficient sealing performance, the injection time of the puncture sealant was shortened, and puncture repair with a smaller amount of puncture sealant became possible. Furthermore, the puncture repair kit for storing the puncture sealing agent of the present invention can be downsized.

-Solid content rate As described above, the puncture sealing agent of the present invention requires that the solid content rate be in the range of 5% by mass to 19% by mass, and in the range of 10% by mass to 19% by mass. Is more preferable.
When the solid content exceeds 19% by mass, the viscosity of the puncture sealant increases, and the ease of injection and the spreadability within the tire deteriorate. On the other hand, if it is less than 5% by mass, it is impossible to ensure sufficient sealing properties.

  In addition, the said solid content rate can be calculated | required as follows. First, 55 g (G1) of the puncture sealing agent is dried at 40 ° C. for 48 hours, and further dried at 80 ° C. for 48 hours. It can be determined by measuring the mass (G2) of the residue after drying and dividing the mass (G2) of the residue by the mass (G1) of the original puncture sealant.

  The said solid content rate in the puncture sealing agent of this invention can be achieved by adjusting the compounding quantity of the component which remains as solid content in a puncture sealing agent, such as the said rubber particle and an adhesive, for example.

-Content ratio of pressure-sensitive adhesive with respect to rubber particles As described above, the content ratio of pressure-sensitive adhesive with respect to rubber particles is required to be in the range of 9.8 mass% to 100 mass%.
When the content ratio of the adhesive to the rubber particles exceeds 100% by mass, sufficient injection ease and spreadability in the tire cannot be ensured. On the other hand, when the content ratio is less than 9.8% by mass, sufficient sealing property is secured. It becomes impossible to do.

The content ratio of the adhesive to the rubber particles is calculated by the following method.
First, “the amount of latex containing rubber particles × the solid content of latex” is A, and “the amount of emulsion containing an adhesive × the solid content of the emulsion” is B. From the above A and B, the content ratio of the pressure-sensitive adhesive to the rubber particles is calculated by the formula “B / A × 100”.

Moreover, it is preferable that the viscosity of the puncture sealing agent of this invention provided with said requirements is 3 mPa * s-2000 mPa * s in the conditions (60 degreeC--30 degreeC) assumed as an actual use condition. Further, it is more preferably 3 mPa · s to 1000 mPa · s, and particularly preferably 3 mPa · s to 700 mPa · s.
By being 3 mPa · s or more, liquid leakage at the time of pouring into the valve due to the viscosity being too low can be suitably prevented. On the other hand, when it is 2000 mPa · s or less, the resistance at the time of injection does not become too strong, and the ease of injection is obtained. Further, the spreadability on the inner surface of the tire is kept good, and a high seal ring property is obtained.
The viscosity can be measured with a B-type viscometer or the like.

<Material of puncture sealant>
The puncture sealing agent of the present invention contains at least rubber particles and a pressure-sensitive adhesive, and optionally contains other components such as an antifreezing agent.

(Rubber particles)
The rubber particles used in the present invention are preferably mixed in a latex state in the production stage of the puncture sealing agent. The rubber latex is not particularly limited, and at least one selected from NR (natural rubber) latex, synthetic rubber latex, and synthetic resin latex can be 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 (chloroprene rubber) latex, Examples include IR (isoprene rubber) latex, polysulfide rubber latex, and the like.

  Synthetic resin latex includes 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, vinylidene chloride latex, Examples thereof include polyvinylidene chloride latex and polystyrene latex.

  Among these, synthetic rubber latex is more preferably used, and SBR (styrene butadiene rubber) latex or BR (polybutadiene rubber) latex is particularly preferable.

  The content of the rubber latex is adjusted so that the solid content ratio and the content ratio of the adhesive to the rubber particles are achieved. In addition, as content in a puncture sealing agent, it is preferable to contain 2.5 mass%-17.30 mass% in solid content, It is more preferable to contain 5 mass%-16 mass%, 9 mass%-16 mass% % Is particularly preferable.

(Adhesive)
The pressure-sensitive adhesive used in the present invention is preferably mixed in an emulsion state at the production stage, and it is particularly preferable to use a resin-based emulsion.

As the resin-based emulsion, those compatible with the aforementioned latex are preferably used. The resin emulsion uses a known surfactant (preferably a nonionic surfactant) as an emulsifier, and a terpene resin such as a rosin ester resin or a terpene phenol resin or a butyl rubber such as polyisobutylene as a resin component. A system material etc. can be used.
Here, the fact that the resin-based emulsion is “compatible” with the latex means that the resin-based emulsion does not coagulate the rubber particles in the latex at all. It shows that it is used as what improves adhesive force. For example, a resin can be used by being added to an elastomer as a rubber film tackifier.

  As said terpene phenol resin, (alpha) -pinene phenol resin, dipentene phenol resin, terpene bisphenol resin, or what hydrogenated these can be used. Commercially available products can also be used.

  The content of the pressure-sensitive adhesive is preferably in the range of 0.45% by mass to 9.5% by mass and more preferably in the range of 2% by mass to 8% by mass with respect to the total mass of the puncture sealing agent. preferable.

(Antifreezing agent)
The puncture sealing agent of the present invention preferably contains an antifreezing agent. The antifreezing agent is not particularly limited, and ethylene glycol, propylene glycol and the like can be used. The content of such an antifreezing agent is preferably 10% by mass to 50% by mass. When it is 10% by mass or more, sufficient anti-freezing properties at low temperatures can be obtained, and when it is 50% by mass or less, the amount of glycol relative to the amount of rubber particles does not increase excessively, and agglomeration occurs during puncture repair. The state in which the rubber particle particles dispersed in the glycol is suppressed, and sufficient sealing properties can be obtained.

  Moreover, the puncture sealant of the present invention can contain water for dilution. Furthermore, a normal dispersant, an emulsifier, a foam stabilizer, or a pH adjuster such as ammonia or caustic soda may be added to the puncture sealant.

<Manufacture of puncture sealant>
The puncture sealant of the present invention can be produced by mixing the above-described materials by a known method. As described above, the rubber particles are preferably mixed in a latex state, and the adhesive is preferably mixed in an emulsion state.
In addition, the production, storage, and filling of the puncture sealing agent is preferably performed in an atmosphere of nitrogen or a rare gas in order to avoid oxidation or the like.

<How to repair puncture>
As a puncture repair method using the puncture sealing agent of the present invention, a known method can be applied. That is, first, the sealed container containing the puncture sealing agent is connected to the valve opening of the tire, and the puncture sealing agent contained in the sealed container is injected. Thereafter, the tire may be rotated so that the puncture sealing agent spreads on the inner surface of the tire and can seal the puncture hole.

  Such a puncture sealant can be injected into the tire using various pump-up devices. For example, it can inject | pour inside a tire with the pump up apparatus 20 as shown in FIG.

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

  Further, the pressure-resistant sealed container 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 a tire valve 10 is connected to the other end of the hose 8. A screw adapter 9 to be screwed to is attached.

  The pressure-resistant sealed container 4 includes a jacket 11 having a filling stub 12 and filled with water. If necessary, calcium chloride as a heating source can be filled into the filling stub 12. 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, for example, a cigarette lighter.

  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-resistant sealed container 4. Then, the compressed air introduced from the air compressor 1 into the pressure-resistant sealed container 4 through the gas introduction unit 3 pushes out the puncture sealing agent 6 from the outlet valve 7 and introduces it into the tire through the tire valve 10. 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.

  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.

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto.
[Examples 1-4 and Comparative Examples 1-4]
The rubber latex containing rubber particles, the emulsion containing the adhesive, the antifreeze agent, and the water described in Table 1 and Table 2 were mixed so as to have the ratios shown in Table 1 and Table 2, and Comparative Examples 1 to 8 And the puncture sealing agent which concerns on Examples 1-5 was produced.

[Evaluation]
About the produced puncture sealing agent, the following evaluation items were evaluated.
・ Punk sealability:
The prepared puncture sealant was injected into a tire with a φ4 mm nail hole, and the tire internal pressure was increased and the tire was mounted on a car. Then, the car was run and evaluated according to the following criteria.
○: Sealing completed within 10 km of replenishment travel (internal pressure drop becomes 0)
Δ: Sealing completed within 10 km to 20 km (internal pressure drop is reduced to 0)
X: The internal pressure drop does not stop even if it exceeds 20 km

·viscosity:
The viscosity of the puncture sealant was measured in a −30 ° C. environment using a B-type viscometer (manufactured by Toki Sangyo) and evaluated according to the following criteria.
◎: 400 mPa · s or less ○: Over 400 mPa · s to 600 mPa · s or less Δ: Over 600 mPa · s to 700 mPa · s or less ×: Over 700 mPa · s

3 Gas introduction part 4 Pressure-resistant sealed container 6 Puncture sealant 7 Outlet valve 10 Tire valve 20 Pump-up device

Claims (3)

Contains at least rubber particles and an adhesive,
The solid content is 5% by mass to 19% by mass,
The puncture sealing agent, wherein the content ratio of the adhesive to the rubber particles is 9.8 mass% to 100 mass%.   Examples of the rubber particles include SBR (styrene butadiene rubber), NBR (acrylonitrile butadiene rubber), MBR (acrylic rubber), BR (polybutadiene rubber), IIR (butyl rubber), CR (chloroprene rubber), IR (isoprene rubber), and polysulfide. The puncture sealing agent according to claim 1, wherein at least one selected from rubber is used.   The puncture sealing agent according to claim 1 or 2, wherein at least one selected from a rosin ester resin, a terpene resin, and a butyl rubber-based material is used as the adhesive.