JP2007224240A - Puncture sealing material for tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a puncture sealing material for tire capable of decreasing the amount to be injected into a tire, generating low noise in driving and keeping the driving stability and provide a puncture sealing material for tire exhibiting excellent sealing performance even in rainy or cold environment. <P>SOLUTION: The puncture sealing material for tire is composed of a first liquid agent containing a cationic resin and a second liquid agent containing an anionic resin., especially a combination of a cationic urethane emulsion and an anionic chloroprene emulsion. The puncture sealing material for tire can decrease the amount to be injected into the tire, generates low noise in driving and keeps driving stability. Especially when the first and the second agents have hydrogen ion exponents falling within a specific range, the puncture sealing material for tire exhibits excellent sealing performance in rainy or cold environment. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a tire puncture seal material.

Conventionally, as a tire puncture sealing material for repairing a punctured tire, a natural rubber latex blended with a tackifying resin emulsion and an antifreezing agent has been frequently used (for example, see Patent Documents 1 and 2).
This tire puncture sealant is a latex in which natural rubber particles and tackifying resin particles are repelled by ionic repulsion in an aqueous solution of an antifreeze and dispersed.
As this type of tire puncture sealant, for example, “a puncture sealant for a tire containing at least a natural rubber latex, a tackifying resin emulsion and an antifreezing agent, wherein the solid content A of the natural rubber latex and the tackifying resin are used. The solid content A of the natural rubber latex is 30 to 60 parts by weight with respect to 100 parts by weight of the total solids, which is the sum A + B + C of the solids B of the emulsion and the cryoprotectant C. The content of component B was 10 to 30 parts by weight, the content of the antifreezing agent C was 20 to 50 parts by weight, and an aromatic modified terpene resin was used as the tackifying resin of the tackifying resin emulsion A tire puncture sealant characterized by the above is known (see Patent Document 1).

  The tire puncture sealing material as described above is usually injected into the tire from the air filling portion of the tire, filled with air up to a predetermined air pressure, and then traveled to reach the puncture hole. And the aggregate of a natural rubber particle is formed with the compressive force and shearing force which are received when a tire rotates and contacts, and a puncture hole is sealed.

JP 2004-035867 A Japanese Patent No. 3210863

However, since the tire puncture sealing materials described in Patent Documents 1 and 2 have a relatively slow film formation rate, there is a problem that the tire puncture sealant flows out of the tire before sealing the puncture hole. Therefore, it was necessary to inject the tire puncture sealant into the tire in a relatively large amount (usually about 400 to 500 ml).
On the other hand, when a small amount of liquid is present in the tire, this is not a problem. However, when a large amount of liquid is present, there are problems such as noise during traveling and decreased traveling stability.

  In addition, tire puncture seal materials are required to have the ability to repair punctures under weather conditions such as rain and snow or even under low temperatures (sealability), but conventional tire puncture seal materials are required under these conditions. In some cases, the sealing performance deteriorates.

  Accordingly, an object of the present invention is to provide a tire puncture seal material that can reduce the amount injected into a tire, has less noise during traveling, and can maintain traveling stability. Furthermore, it aims at providing the tire puncture sealing material which is excellent also in the sealing performance at the time of rainy weather or low temperature.

  As a result of intensive studies, the inventor has a liquid first agent containing a cationic resin and a liquid second agent containing an anionic resin. The present invention has been completed by discovering that the tire puncture sealant can reduce running noise and maintain running stability.

That is, the present invention provides the following (1) to (10).
(1) A tire puncture sealant having a liquid first agent containing a cationic resin and a liquid second agent containing an anionic resin.
(2) The tire puncture seal material according to (1), wherein the first agent is a cationic urethane emulsion.
(3) The tire puncture sealant according to (1) or (2) above, wherein the first agent has a hydrogen ion index of 4.0 to 6.0.
(4) The tire puncture sealant according to any one of (1) to (3), wherein the second agent is an anionic chloroprene emulsion.
(5) The tire puncture sealant according to any one of (1) to (4), wherein the second agent has a hydrogen ion index of 7.0 to 9.0.
(6) The tire puncture sealing material according to any one of (1) to (5), wherein the first agent and / or the second agent further contains a tackifier.
(7) The tire puncture sealant according to (6), wherein the tackifier is an emulsion obtained by emulsifying a resin.
(8) The tire puncture seal material according to (6) or (7), wherein the tackifier includes at least one selected from the group consisting of a rosin resin, a terpene resin, and a hydrogenated terpene resin.
(9) The tire puncture sealing material according to any one of (1) to (8), wherein the first agent and / or the second agent further contains an antifreezing agent.
(10) The tire puncture sealing material according to (9), wherein the antifreezing agent is ethylene glycol and / or propylene glycol.

  The tire puncture seal material of the present invention can reduce the amount injected into the tire, has less noise during traveling, and can maintain traveling stability. In particular, when the first agent and the second agent have a hydrogen ion index within a specific range, the sealing properties are excellent in rainy weather or at low temperatures.

Hereinafter, the present invention will be described in more detail.
The tire puncture seal material of the present invention is a tire puncture seal material having a liquid first agent containing a cationic resin and a liquid second agent containing an anionic resin.

The liquid first agent (hereinafter also referred to as “first agent”) containing the cationic resin is not particularly limited as long as it contains a positively charged resin and is liquid when used. Below, what is liquid at -40-80 degreeC is preferable from the point which does not choose a use environment. For example, a positively charged resin dispersed in water and / or a solvent (cationic resin emulsion), a positively charged liquid resin, and the like can be given.
Specific examples of the first agent include cationic urethane emulsions.

  A cationic urethane emulsion is a dispersion of positively charged polyurethane particles in water. Preferable examples of the cationic urethane emulsion include a urethane emulsion obtained by reacting a urethane prepolymer having a tertiary amino group with a neutralizing agent (acid) or a quaternizing agent in water.

  Specifically, as the urethane prepolymer, for example, a polyisocyanate compound (A) having two or more isocyanate groups, a compound (B) having two or more active hydrogens, a group having reactivity with an isocyanate group, Preferable examples include urethane prepolymers produced by copolymerizing a compound (C) having a tertiary amino group.

As said polyisocyanate compound (A), the various thing used for manufacture of a normal polyurethane resin can be used. Specifically, for example, TDI such as 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate; MDI such as diphenylmethane-4,4′-diisocyanate; tetramethylxylylene diisocyanate (TMXDI), trimethylhexamethylene Diisocyanate (TMHMDI), 1,5-naphthalene diisocyanate, ethylene diisocyanate, propylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), xylylene diisocyanate (XDI), triphenylmethane triisocyanate, norbornane skeleton And modified products such as diisocyanates (NBDI) having these and isocyanurate forms thereof.
These may be used alone or in combination of two or more.

  Among these isocyanate group-containing compounds, TDI and MDI are preferable. Since these polyisocyanates are general-purpose, they are inexpensive and easily available.

The compound (B) is not particularly limited as long as it is a compound having two or more active hydrogens. Specific examples include a polyol compound, an amine compound, and an alkanolamine. These may be used alone or in combination of two or more.
Among these, a polyol compound is preferable.

Specific examples of the polyol compound include polyether-based polyols such as polytetramethylene glycol, polyethylene glycol, polypropylene glycol, polyoxypropylene glycol, and polyoxybutylene glycol; polyolefins such as polybutadiene polyol and polyisoprene polyol. Polyols; adipate polyols such as 3-methylpentanediol adipate; lactone polyols; polyester polyols such as castor oil.
These may be used alone or in combination of two or more.

  The polyol compound preferably has a number average molecular weight of about 500 to 10000, more preferably about 2000 to 6000.

  Specific examples of the amine compound include ethylenediamine and hexamethylenediamine.

  Specific examples of the alkanolamine include ethanolamine and propanolamine.

The compound (C) is a compound having a group having reactivity with an isocyanate group and a tertiary amino group.
Specific examples of the group having reactivity with an isocyanate group include a hydroxy group, an amino group (—NH ₂ ), an imino group (—NH—), a mercapto group, and the like.

  As said compound (C), the compound represented by following formula (1) is mentioned suitably, for example.

In the above formula (1), R represents an alkyl group or hydroxyalkyl group having 1 to 4 carbon atoms, R ¹ and R ² may be the same or different and each an alkylene group having 1 to 4 carbon atoms Represents.
The compound represented by the above formula (1) includes a diol compound having a tertiary amino group and a triol compound having a tertiary amino group.

  Specific examples of such a compound (C) include N-methyl-N, N-diethanolamine, N-ethyl-N, N-diethanolamine, N-isobutyl-N, N-diethanolamine, and diisopropanolamine. And alkanolamines such as triethanolamine. These may be used alone or in combination of two or more.

Although the manufacturing method of the said urethane prepolymer is not specifically limited, For example, the method of superposing | polymerizing a polyisocyanate compound (A), a compound (B), and a compound (C) by stirring simultaneously etc. is mentioned.
In the production of the urethane prepolymer, the order in which the compound (B) and the compound (C) are added is not particularly limited, and may be added simultaneously, or one of them may be added first. For example, in accordance with a normal method for producing a urethane prepolymer, a method in which a polyisocyanate compound (A) and a compound (B) are reacted to produce a urethane prepolymer, and then a compound (C) is added and added is used. it can.

The copolymerization is preferably performed so that the isocyanate group content (NCO%) of the resulting urethane prepolymer is 0.3 to 3%.
Moreover, 1-50 mass% of polyisocyanate compound (A), 30-90 mass% of compound (B) with respect to the total mass of polyisocyanate compound (A), compound (B), and compound (C), compound It is preferable to contain 0.1 to 20% by mass of (C) and stir these under an inert gas atmosphere at 60 to 90 ° C. for about 2 to 8 hours. Here, NCO% represents mass% of NCO groups with respect to the total mass of the urethane prepolymer.

Moreover, the said copolymerization can be performed in presence of urethanization catalysts, such as an organotin compound, an organic bismuth, and an amine as needed, and it is preferable to carry out in presence of an organotin compound.
Specific examples of the organic tin compound include stannous acetate such as stannous acetate, stannous octoate, stannous laurate, and stannous oleate; dibutyltin acetate, dibutyltin dilaurate, and dibutyltin. Dialkyltin salts of carboxylic acids such as maleate, dibutyltin di-2-ethylhexoate, dilauryltin diacetate, dioctyltin diacetate; hydroxylations such as trimethyltin hydroxide, tributyltin hydroxide, trioctyltin hydroxide Trialkyltin: Dialkyltin oxides such as dibutyltin oxide, dioctyltin oxide and dilauryltin oxide; dialkyltin chlorides such as dibutyltin dichloride and dioctyltin dichloride, and the like.
These may be used alone or in combination of two or more.
Of these, dibutyltin dilaurate, dibutyltin acetate, and dibutyltin maleate are preferred because they are relatively inexpensive and easy to handle.

  The weight average molecular weight of the urethane prepolymer obtained by such copolymerization is preferably 1500 to 30000, and more preferably 3000 to 20000.

  The urethane prepolymer is emulsified by reacting with a neutralizing agent (acid) or a quaternizing agent in water to form a stabilized urethane emulsion.

The neutralizing agent is not particularly limited as long as it is a Lewis acid, and specifically, for example, inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, phosphorous acid, acetic acid, propionic acid, formic acid, butyric acid, lactic acid Organic acids such as malic acid and citric acid. These may be used alone or in combination of two or more.
Among these neutralizing agents, hydrochloric acid is preferable because it is inexpensive and easily available.

  The quaternizing agent is a compound capable of quaternizing the tertiary amino group of the urethane prepolymer. Specifically, for example, ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, etc. Epoxy compounds; dialkyl sulfates such as dimethyl sulfate and diethyl sulfate; alkyl sulfonates such as methyl paratoluenesulfonate; alkyl halides such as methyl chloride, ethyl chloride, benzyl chloride, methyl bromide, and ethyl bromide .

  The urethane prepolymer can be dispersed in water by adding a viscosity modifier and a chain extender, if necessary, in addition to the neutralizing agent or quaternizing agent.

  Examples of the viscosity modifier include organic solvents that are compatible with water, and specific examples thereof include ethyl acetate, acetone, and methyl ethyl ketone.

  Specific examples of the chain extender include aliphatic diamines such as ethylenediamine, propylenediamine, hexamethylenediamine, and triethylenetetramine; alicyclic diamines such as isophorone diamine and piperazine; aromatic diamines such as diphenyldiamine; A triamine etc. are mentioned.

  The method for producing the urethane emulsion is not particularly limited. For example, the urethane prepolymer and the neutralizing agent or the quaternizing agent, and if necessary, the viscosity modifier, the chain extender and the like are added to water. Then, a method of stirring and the like can be mentioned.

  As the first agent other than the urethane emulsion, polyacrylamide such as poly N, N-dialkylacrylamide and poly N, N-dialkylaminopropyl acrylamide; acrylic resin such as poly N, N-dialkylaminoethyl methacrylate; polyamide resin; Ethyleneimine resin; cationized cellulose and the like.

The hydrogen ion index (pH) of the first agent is preferably 4.0 to 6.0 from the viewpoint of excellent balance between stability and reactivity of the emulsion, and is 5.0 to 6.0. Is more preferable. When the pH of the first agent is within this range, the sealing properties are excellent in rainy weather or at low temperatures.
The hydrogen ion index can be adjusted by adjusting the amount of the neutralizing agent or adding a base as a pH adjusting agent.
Although it does not specifically limit as a base used for a pH adjuster, Specifically, a sodium hydroxide, potassium hydroxide, a tertiary amine etc. are mentioned, for example.

Next, the liquid second agent containing an anionic resin will be described.
The second agent contains a negatively charged resin and is not particularly limited as long as it is in a liquid state at the time of use. preferable. For example, a negatively charged resin dispersed in water and / or a solvent (anionic resin emulsion), a negatively charged liquid resin, or the like can be given.
Specific examples of the second agent include anionic chloroprene emulsions.

An anionic chloroprene emulsion is a dispersion of negatively charged chloroprene rubber particles in water.
Preferable examples of the anionic chloroprene emulsion include a chloroprene emulsion obtained by reacting a chloroprene rubber having an anionic group with a neutralizing agent (base) in water.
Here, the “anionic group” refers to a group that can be negatively charged by neutralization with a base. Specifically, for example, a carboxy group, a sulfo group, a phosphoric acid group and the like are preferable.

  Suitable examples of the chloroprene rubber include a copolymer of a chloroprene monomer and a vinyl monomer having an anionic group (hereinafter also referred to as “copolymer (D)”). . The polymer (D) may contain a copolymerizable ethylenically unsaturated monomer other than the above monomer as a monomer component, if necessary.

  Specific examples of the vinyl monomer having an anionic group include unsaturated fatty acids such as acrylic acid, methacrylic acid, fumaric acid, maleic acid, and crotonic acid, and styrene sulfonic acid. Of these, methacrylic acid is preferred.

  0.1-20 mass parts is preferable with respect to 100 mass parts of chloroprene monomers, and, as for the usage-amount of the vinyl monomer which has the said anionic group, 1-15 mass parts is more preferable.

Specific examples of the copolymerizable ethylenically unsaturated monomer include ethylene, styrene, methyl methacrylate, acrylonitrile, 2,3-dichlorobutadiene, 1-chlorobutadiene, and the like.
The amount of the copolymerizable ethylenically unsaturated monomer used is preferably 30 parts by mass or less with respect to 100 parts by mass of the chloroprene monomer.

The method for producing the anionic chloroprene-based emulsion is not particularly limited. For example, the chloroprene monomer, the vinyl monomer having an anionic group, and, if necessary, other copolymerizable ethylenically unsaturated monomers. A method of radical emulsion polymerization of the body in water is preferred.
Emulsion polymerization can be performed by a known method. Specifically, for example, water, each of the above monomers, a neutralizing agent (base), a polymerization initiator, a chain transfer agent, a polymerization terminator and the like are mixed. And a polymerization method. The polymerization temperature can usually be carried out in the range of 0 to 80 ° C, and preferably in the range of 5 to 50 ° C.

  The neutralizing agent is not particularly limited as long as it is a Lewis base, and specific examples include sodium hydroxide, potassium hydroxide, and tertiary amine.

As the polymerization initiator, known free radical generating substances, specifically, for example, peroxides such as potassium persulfate and ammonium persulfate; inorganic or organic peroxides such as hydrogen peroxide and t-butyl hydroperoxide Etc.
Specific examples of the chain transfer agent include alkyl mercaptans, halogenated hydrocarbons, alkyl xanthogen disulfides, sulfur and the like.
Specific examples of the polymerization terminator include phenothiazine, 2,6-t-butyl-4-methylphenol, hydroxylamine and the like.

  Examples of the second agent other than the anionic chloroprene emulsion include natural polymers such as carboxymethyl cellulose, alginic acid, and carrageenan, and polyacrylic acid.

The hydrogen ion index (pH) of the second agent is preferably 7.0 to 9.0 from the viewpoint of excellent balance between stability and reactivity of the emulsion, and is 8.0 to 9.0. Is more preferable. When the pH of the second agent is within this range, the sealing properties are excellent when it is raining or at low temperatures.
Adjustment of the hydrogen ion index can be performed by adjusting the amount of the neutralizing agent or adding an acid as a pH adjusting agent.
The acid used for the pH adjuster is not particularly limited. Specifically, for example, inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, phosphorous acid, acetic acid, propionic acid, formic acid, butyric acid, lactic acid, Examples include organic acids such as malic acid and citric acid. These may be used alone or in combination of two or more.

It is preferable that the first agent and / or the second agent further contain a tackifier from the viewpoint of obtaining excellent sealing properties.
Specific examples of the tackifier include rosin resins such as rosin esters, polymerized rosin esters, and modified rosins; terpene resins such as terpene phenols and aromatic terpenes; hydrogenated hydrogenated terpene resins. Examples include terpene resins; phenol resins; xylene resins. In addition, an emulsion obtained by emulsifying these resins is one of preferred embodiments from the viewpoint of excellent compatibility with the urethane emulsion and the chloroprene emulsion. These may be used alone or in combination of two or more.
Among these, a tackifier containing at least one selected from the group consisting of rosin-based resins, terpene-based resins, and hydrogenated terpene-based resins is preferable from the viewpoint of excellent sealing properties.

From the point which is excellent in sealing performance, content of the solid content of the said tackifier is 5-200 mass parts with respect to a total of 100 mass parts of solid content (except for tackifier) of the 1st agent and the 2nd agent. Is preferable, 50-150 mass parts is more preferable, and 80-120 mass parts is still more preferable.
Here, the solid content of the tackifier means the total of the components contained in the tackifier excluding water and the solvent. The solid content of the first agent and the second agent means the total of the components contained in the first agent and the second agent excluding the tackifier, water, and the solvent.

It is preferable that the first agent and / or the second agent further contains an antifreezing agent.
Although it does not specifically limit as an antifreezing agent, Specifically, ethylene glycol and propylene glycol are mentioned suitably, for example. These may be used alone or in combination of two or more.

The content of the antifreeze agent is superior to the performance of preventing the tire puncture sealant from freezing, and therefore the solid content of the first agent and the second agent (excluding the antifreeze agent) is 100 parts by mass in total. 80-300 mass parts is preferable, 100-200 mass parts is more preferable, and 110-180 mass parts is still more preferable.
The solid content of the first agent and the second agent means the total of the components contained in the first agent and the second agent excluding the antifreezing agent, water and the solvent.

  The first agent and / or the second agent may include, in addition to the above-described components, a filler, an antioxidant, an antioxidant, a pigment (dye), a plasticizer, a thixotropic agent, and an ultraviolet absorber, as desired. And various additives such as flame retardants, surfactants (including leveling agents), dispersants, dehydrating agents, antistatic agents, and the like.

  Examples of the filler include organic or inorganic fillers having various shapes. Specifically, for example, fumed silica, calcined silica, precipitated silica, ground silica, fused silica; diatomaceous earth; iron oxide, zinc oxide, titanium oxide, barium oxide, magnesium oxide; calcium carbonate, magnesium carbonate, zinc carbonate; Waxite clay, kaolin clay, calcined clay; carbon black; these fatty acid treated products, resin acid treated products, urethane compound treated products, fatty acid ester treated products and the like.

Specific examples of the anti-aging agent include hindered phenol compounds.
Specific examples of the antioxidant include butylhydroxytoluene (BHT) and butylhydroxyanisole (BHA).

  Specific examples of the pigment include inorganic pigments such as titanium oxide, zinc oxide, ultramarine, bengara, lithopone, lead, cadmium, iron, cobalt, aluminum, hydrochloride, sulfate, etc .; azo pigment, phthalocyanine pigment, quinacridone Pigment, quinacridone quinone pigment, dioxazine pigment, anthrapyrimidine pigment, anthanthrone pigment, indanthrone pigment, flavanthrone pigment, perylene pigment, perinone pigment, diketopyrrolopyrrole pigment, quinonaphthalone pigment, anthraquinone pigment, thioindigo pigment, benzimidazolone Examples thereof include organic pigments such as pigments, isoindoline pigments, and carbon black.

  Specific examples of the plasticizer include diisononyl phthalate (DINP); dioctyl adipate, isodecyl succinate; diethylene glycol dibenzoate, pentaerythritol ester; butyl oleate, methyl acetylricinoleate; tricresyl phosphate, trioctyl phosphate An adipate propylene glycol polyester, an adipate butylene glycol polyester, and the like.

  Specific examples of the thixotropic agent include aerosil (manufactured by Nippon Aerosil Co., Ltd.), disparon (manufactured by Enomoto Kasei Co., Ltd.), and the like.

Specific examples of the flame retardant include chloroalkyl phosphate, dimethyl / methylphosphonate, bromine / phosphorus compound, ammonium polyphosphate, neopentyl bromide-polyether, brominated polyether, and the like.
Specific examples of the antistatic agent include quaternary ammonium salts; hydrophilic compounds such as polyglycols and ethylene oxide derivatives.

Hereinafter, the usage method of the tire puncture sealing material of this invention is demonstrated. However, the method of using the tire puncture seal material of the present invention is not limited to the following method.
The tire puncture seal material of the present invention can be used as the two-component type composed of the first agent and the second agent described above.

First, the 1st agent or 2nd agent of the tire puncture sealing material of this invention is inject | poured into a puncture hole from the exterior of a tire.
The injection method is not particularly limited, and examples thereof include a method using a syringe.

Next, the other of the first agent or the second agent is injected into the tire from the air filling portion of the tire, and the first agent and the second agent are brought into contact with each other at the puncture hole portion. When the first agent and the second agent come into contact with each other, the film can be quickly formed and the puncture hole can be closed.
After that, if necessary, the tire can be filled with air up to a predetermined pressure, so that the vehicle can run as usual.

  Before or after injecting the first agent or the second agent into the tire from the air filling portion of the tire, the tire is rotated so that the puncture hole is lowered so that the injected liquid can reach the puncture hole. It is preferable to point. This step may not be performed when the puncture hole is already facing downward and the first agent and the second agent can be contacted at the puncture hole portion.

As another method of use, there is a method of injecting the first agent and the second agent into the puncture hole from the outside of the tire. The order of injecting the first agent and the second agent is not limited, and they may be injected at the same time.
According to this method, the first agent and the second agent can be more reliably brought into contact with each other at the puncture hole portion as compared with the above-described method, so that the amount of liquid injected into the tire can be further reduced and noise during running is reduced. , Running stability can be maintained.

  Since the tire puncture sealant of the present invention has a property of instantly forming a film by ionic bonding when the first agent and the second agent come into contact with each other, a large amount of liquid is injected into the tire like a conventional tire puncture sealant. Since there is no need to do so, there is little noise during traveling and traveling stability can be maintained. Moreover, when the 1st agent and the 2nd agent are the hydrogen ion index | exponents of a specific range, it is excellent also in the sealing performance at the time of rain or at low temperature.

Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these.
<Preparation of first agent (Synthesis Examples 1-2)>
Tolylene diisocyanate (Mitsui Takeda Chemical Co., Ltd.), 3-methylpentanediol adipate (Kuraray Polyol P2010, Kuraray Co., Ltd.) and N-methyldiethanolamine (Wako Pure Chemical Industries, Ltd.) are shown in Table 1 below. (G) A urethane prepolymer was synthesized by mixing (NCO% = 4.6%).
Next, hydrochloric acid (manufactured by Wako Pure Chemical Industries, Ltd.), terpene tackifier (YS Resin TO115, manufactured by Yasuhara Chemical, Synthesis Example 1 only), and piperazine 6 water as a chain extender were added to the obtained urethane prepolymer. A Japanese product (manufactured by Nippon Emulsifier Co., Ltd.), distilled water, and ethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd.) were added in the amount (g) shown in Table 1 and sufficiently stirred to emulsify. A cationic urethane emulsion of Synthesis Example 2 was obtained.
Each obtained synthesis example was used in Examples and Comparative Examples described later as the first agent.
The hydrogen ion index of the obtained cationic urethane emulsion was measured with a pH meter (manufactured by Hitachi High-Technology Co., Ltd., hereinafter the same). The results are shown in Table 1.

<Preparation of second agent (Formulation Examples 1 to 6)>
An anionic chloroprene emulsion (C-84, manufactured by Sumika Bayer Urethane Co., Ltd.) and hydrochloric acid (manufactured by Wako Pure Chemical Industries, Ltd.) as a pH adjuster were mixed in the amounts (parts by mass) shown in Table 2 below. Each second agent was obtained.
The hydrogen ion index of each obtained second agent was measured with a pH meter. The results are shown in Table 2.
Moreover, about each obtained 2nd agent, the compounding stability, freeze-thaw stability, and long-term stability were evaluated with the following method.
The results are shown in Table 2.

(Compounding stability test)
The state of dispersion after each second agent was allowed to stand at 20 ° C. for 24 hours was visually observed. “○” indicates that there was no precipitation and it was uniformly dispersed, and “△” indicates that the resin content was slightly separated. It was.

(Freeze-thaw stability test)
Each second agent was cooled at −20 ° C. for 8 hours and then heated at 80 ° C. for 16 hours. After repeating this cycle 10 times, the dispersion state was visually observed, and there was no precipitation and it was uniformly dispersed. The thing with "(circle)" and the thing in which the aggregate and the film existed was made into "x".

(Long-term stability test)
After each second agent was heated at 80 ° C. for 90 days, the dispersion state was visually observed. “○” indicates that there was no precipitation and it was uniformly dispersed, and “×” indicates that an aggregate or film was present. "

<Sealability Test and Curability Test (Examples 1-12 and Comparative Examples 1-8)>
1. Room Temperature Sealing Property A hole was formed by penetrating a nail having a diameter of 5 mm through a tread of a member obtained by cutting the tire tread portion into a length of 15 cm and a width of 22 cm.
In the environment of 20 ° C. and 65% RH, from the tread side (outside), the second agent of any of Formulation Examples 1 to 6 in the amount (g) shown in Table 3 was injected into the hole with a syringe (Comparative Example) 1-2 are excluded).
Next, assuming that the first agent was injected into the inside of the tire, from the back side (inside) of the tread to the hole portion, the amount (g) of the first agent of Synthesis Examples 1 and 2 shown in Table 3 and And a rosin ester tackifier (rosin ester tackifier emulsion, Harrier Star SK-508, manufactured by Harima Chemicals).
In order to promote film formation, the periphery of the hole portion was hit with a mallet five times from the tread side.
After leaving for 5 minutes in an environment of 20 ° C. and 65% RH, water was sprayed from the tread side to the hole portion, and the presence or absence of water leakage to the back surface (inside) was observed.
The case where there was no water leak was indicated as “◯”, and the case where there was a water leak was indicated as “x”.
The results are shown in Table 3.

  The tire puncture seal materials of Comparative Example 1 and Comparative Example 2 were evaluated for blending stability, freeze-thaw stability, and long-term stability by the same method as the blending example. As a result, the tires of Comparative Example 1 and Comparative Example 2 The puncture sealant had good freeze-thaw stability and long-term stability.

2. Water-resistant sealing property After the tire tread part is cut to 15cm in length and 22cm in width, a 5mm diameter nail is penetrated to form a hole, and the tread part is fully wetted. The sealing property was evaluated.
The results are shown in Table 3.

3. Cold seal resistance Each member and each tire puncture sealant (first agent and second agent) was cooled to −20 ° C., and the sealability was evaluated in the same manner as the above-described normal temperature sealability.
The results are shown in Table 3.

4). Curability (filming time)
About Examples 1-12, after the 1st agent and 2nd agent contacted in the normal temperature sealing test mentioned above, the time (second) required until aggregation occurred and a film was observed was measured.
For Comparative Examples 1 to 8, the time (seconds) required for aggregation to occur and the film to be observed after hitting the periphery of the hole portion five times with a mallet from the tread side was measured.
The results are shown in Table 3.

<Comparative Example 9>
100 parts by mass of natural rubber latex (HA, manufactured by Felfex), 90 parts by mass of a rosin ester-based tackifier emulsion (Harristar SK70D, manufactured by Harima Chemicals), and 100 parts by mass of ethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd.) Were mixed to obtain a natural rubber-based conventional product (pH 10.0). As a result of evaluating the blending stability, freeze-thaw stability, and long-term stability by the same method as the blending example, all evaluations were good.
About the obtained natural rubber type conventional product, normal temperature sealing properties, water-proof sealing properties, cold sealing properties and curability were evaluated by the same methods as in Comparative Examples 1-8.
The results are shown in Table 3.

As is clear from the results shown in Table 3 above, when the second agent was not used (Comparative Examples 1 and 2), the film forming speed was slow and the film was not sufficiently formed. Both sealing properties and cold-resistant sealing properties were low.
Further, when the first agent was not used (Comparative Examples 3 to 8), the film was not sufficiently formed in the presence of water, and thus the water-resistant sealability was low. In particular, Comparative Examples 3 and 4 also had low room temperature sealing properties and cold sealing properties.
Further, when the conventional natural rubber-based product was used (Comparative Example 9), the film was not sufficiently formed in the presence of water, and thus the water-resistant sealing property was low.
On the other hand, the tire puncture sealing materials of Examples 1 to 12 were excellent in normal temperature sealing properties. In addition, when any one of Formulation Examples 3 to 5 was used as the second agent, the water-proof seal resistance and the cold seal resistance were also excellent. From this result, it was found that when the hydrogen ion index of the second agent is 7.0 to 9.0, the water-resistant seal resistance and the cold seal resistance are also excellent.

  Furthermore, although Comparative Examples 1 to 9 required several minutes to 10 minutes for sufficient film formation, Examples 1 to 12 were sufficiently formed within a few seconds after the first agent and the second agent contacted. It was. That is, the tire puncture seal material of the present invention has no problem of flowing out of the tire before sealing the puncture hole, so that the amount injected into the tire can be reduced, the noise during running is reduced, and running stability is improved. Can be maintained.

Claims (10)

  A tire puncture sealant having a liquid first agent containing a cationic resin and a liquid second agent containing an anionic resin.   The tire puncture sealant according to claim 1, wherein the first agent is a cationic urethane emulsion.   The tire puncture sealant according to claim 1 or 2, wherein a hydrogen ion index of the first agent is 4.0 to 6.0.   The tire puncture seal material according to any one of claims 1 to 3, wherein the second agent is an anionic chloroprene emulsion.   The tire puncture sealing material according to any one of claims 1 to 4, wherein the second agent has a hydrogen ion index of 7.0 to 9.0.   The tire puncture sealing material according to any one of claims 1 to 5, wherein the first agent and / or the second agent further contains a tackifier.   The tire puncture sealant according to claim 6, wherein the tackifier is an emulsion obtained by emulsifying a resin.   The tire puncture seal material according to claim 6 or 7, wherein the tackifier includes at least one selected from the group consisting of a rosin resin, a terpene resin, and a hydrogenated terpene resin.   The tire puncture sealing material according to any one of claims 1 to 8, wherein the first agent and / or the second agent further contains an antifreezing agent.   The tire puncture seal material according to claim 9, wherein the antifreezing agent is ethylene glycol and / or propylene glycol.