Foam for filled tire and filled tire

Abstract

To provide foam for a tire that has excellent elastic deformation property with respect to a temporary load and excellent durability, and to provide a tire.SOLUTION: Foam for a filled tire for filling a cavity part that is formed with a tire body and rims is obtained from a composition including: a polycarbonate polyol; a polyol having a hydroxyl value of 200 to 1000 mgKOH / g; and a polyisocyanate. A filled tire includes a cavity part that is formed with a tire body and rims and filled with the foam for a filled tire.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a foam for an inflated tire and an inflated tire. [Background technology]

[0002] Conventionally, technology related to maintenance-free tires has become important in the industrial tire field due to improvements in autonomous driving technology, etc. As a maintenance-free tire, for example, a puncture-proof filled tire is known (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 58-401 Summary of the Invention [Problem to be solved by the invention]

[0004] The present inventors have examined the filler disclosed in Patent Document 1 and have found that when a large force is temporarily applied to such a filler, the filler may be easily deformed and difficult to return to its original shape (plastic deformation), and that the durability of the filler may not satisfy the level currently required.

[0005] Therefore, an object of the present invention is to provide a foam for filled tires that has excellent elastic deformability against temporary loads and is excellent in durability. Another object of the present invention is to provide an inflated tire. [Means for solving the problem]

[0006] As a result of intensive research to solve the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by a foam obtained from a composition containing a polycarbonate polyol, a polyol having a hydroxyl value of 200 to 1000 mgKOH / g, and a polyisocyanate, and have arrived at the present invention. That is, the present inventors have found that the above problems can be solved by the following configuration.

[0007] [1] A foam for filled tires that fills a cavity formed between a tire body and a rim, the foam for filled tires being obtained from a composition containing a polycarbonate polyol, a polyol having a hydroxyl value of 200 to 1000 mgKOH / g, and a polyisocyanate. [2] Density: 0.1 to 0.5 g / cm 3 The foam for filled tires according to [1], [3] The filled tire foam according to [1] or [2], wherein the polycarbonate polyol comprises polycarbonate polyol 1 having a hydroxyl value of 20 to 100 mgKOH / g, and polycarbonate polyol 2 having a hydroxyl value of more than 100 mgKOH / g and not more than 250 mgKOH / g. [4] The filled tire foam according to any one of [1] to [3], wherein the polyol having a hydroxyl value of 200 to 1000 mgKOH / g includes a polyether polyol having a hydroxyl value of 200 to 400 mgKOH / g. [5] The foam for filled tires according to any one of [1] to [4], wherein the polyisocyanate contains polymeric MDI. [6] The foam for a filled tire according to any one of [1] to [5], wherein the composition further contains water. [7] The foam for filled tires according to any one of [1] to [6], which includes chemical crosslinking. [8] An inflated tire in which a cavity formed by a tire body and a rim is filled with the foam for an inflated tire according to any one of [1] to [7]. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a foam for an infilled tire that has excellent elastic deformability against a temporary load and is excellent in durability. The present invention also provides an inflated tire that has excellent elastic deformation properties against temporary loads and is excellent in durability. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view schematically showing one embodiment of an inflated tire of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described below. The following description of the components may be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. In the present specification, each component can be used alone or in combination of two or more kinds. In this specification, when two or more types of a certain component are used in combination, the "content" of the component means the total content of those two or more types, unless otherwise specified. In the present specification, the method for producing each component is not particularly limited unless otherwise specified, and may be, for example, a conventionally known method. In this specification, being superior in at least one of elastic deformation property and durability against temporary load is also referred to as "having superior effects of the present invention."

[0011] [Foam for filling tires] The foam for a filled tire of the present invention will be described below. The foam for inflated tires of the present invention (foam for inflated tires of the present invention) is a foam for inflated tires that fills a cavity formed by a tire body and a rim, and is obtained from a composition containing a polycarbonate polyol, a polyol having a hydroxyl value of 200 to 1000 mgKOH / g, and a polyisocyanate.

[0012] The reason why the foam of the present invention having the above-mentioned configuration can solve the problems of the present invention is not entirely clear, but the present inventors speculate as follows. That is, it is presumed that the polycarbonate polyol contained as the polyol component in the composition used to obtain the foam of the present invention imparts toughness to the foam of the present invention, and the polyol having a hydroxyl value within a specific range imparts flexibility to the foam of the present invention; therefore, by combining the above-mentioned toughness and flexibility, the foam of the present invention has excellent elastic deformability against temporary loads and is therefore excellent in durability. The mechanism by which the effect is obtained is not limited by the above speculation. In other words, even if the effect is obtained by a mechanism other than the above, it is included in the scope of the present invention.

[0013] [For filling tires] The foam of the present invention is used to fill (fill) a cavity formed by a tire body and a rim in an inflated tire having the tire body and the rim. The foam of the present invention can fill the entire cavity.

[0014] [Composition] The foam of the present invention is obtained from a composition containing a polycarbonate polyol, a polyol having a hydroxyl value of 200 to 1000 mgKOH / g, and a polyisocyanate. In this specification, the above composition is also referred to as a "specific composition."

[0015] [Polycarbonate polyol] In the present invention, the specific composition comprises a polycarbonate polyol. Polycarbonate polyol is a compound having a plurality of repeating units represented by [—RO—CO—O—] and a plurality of hydroxy groups. R (divalent linking group) in the repeating units is not particularly limited.

[0016] The hydroxyl value of the polycarbonate polyol is preferably 10 to 300 mgKOH / g, from the viewpoint of achieving better effects of the present invention.

[0017] (Polycarbonate polyol 1, 2) From the viewpoint of achieving better effects of the present invention, the polycarbonate polyol preferably contains polycarbonate polyol 1 having a hydroxyl value of 20 to 100 mgKOH / g and polycarbonate polyol 2 having a hydroxyl value of more than 100 mgKOH / g and 250 mgKOH / g or less.

[0018] When the polycarbonate polyol contains polycarbonate polyol 1 and polycarbonate polyol 2, from the viewpoint of achieving better effects of the present invention (particularly durability), it is preferable that the hydroxyl value of polycarbonate polyol 2 is more than 100 mgKOH / g and not more than 200 mgKOH / g. When the polycarbonate polyol contains polycarbonate polyol 1 and polycarbonate polyol 2, the upper limit of the hydroxyl value of polycarbonate polyol 1 can be set to 80 mgKOH / g or less. In the present invention, the hydroxyl value of the polycarbonate polyol can be measured in accordance with JIS K1557-1:2007.

[0019] (Polycarbonate polyol 1 and 2 content) When the polycarbonate polyol contains polycarbonate polyol 1 and polycarbonate polyol 2, it is preferable that the content of polycarbonate polyol 1 in the total amount of polycarbonate polyols 1 and 2 is 40 to 60 mass%, with the remainder being polycarbonate polyol 2, from the viewpoint of achieving better effects of the present invention.

[0020] (hydroxy group) From the viewpoint of achieving better effects of the present invention, the polycarbonate polyol preferably has two hydroxy groups per molecule. From the viewpoint of achieving better effects of the present invention, the polycarbonate polyol preferably has a hydroxy group at its terminal.

[0021] (Polycarbonate polyol content) The content of the polycarbonate polyol (when the polycarbonate polyol includes polycarbonate polyols 1 and 2, the total content of these) is preferably 30 to 60 mass % of the total amount of the specific composition, from the viewpoint of achieving better effects of the present invention.

[0022] [Polyol] In the present invention, the specific composition contains a polyol having a hydroxyl value of 200 to 1000 mgKOH / g. In this specification, a polyol having a hydroxyl value of 200 to 1000 mgKOH / g is also referred to as a "specific polyol." The specific polyol is a compound having a hydroxyl value of 200 to 1000 mgKOH / g and having a plurality of hydroxy groups. The specific polyol does not include polycarbonate polyol.

[0023] From the viewpoint of achieving better effects of the present invention, the specific polyol preferably contains a polyol having a hydroxyl value of 200 to 400 mgKOH / g. In the present invention, the hydroxyl value of the specific polyol can be measured in accordance with JIS K1557-1:2007.

[0024] (Polyether polyol) From the viewpoint of achieving better effects of the present invention, the specific polyol preferably contains a polyether polyol having a hydroxyl value of 200 to 1000 mgKOH / g. The polyether polyol is a compound having a polyether skeleton and a plurality of hydroxy groups. From the viewpoint of achieving superior effects of the present invention, the polyether polyol preferably has two primary hydroxy groups (i.e., hydroxy groups bonded to the terminals). From the viewpoint of achieving better effects of the present invention, the specific polyol preferably contains a polyether diol having a hydroxyl value of 200 to 1000 mgKOH / g.

[0025] Examples of the polyether polyol include polyols obtained by adding at least one oxide selected from ethylene oxide, propylene oxide, butylene oxide, etc. to at least one selected from polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerin, 1,1,1-trimethylolpropane, 1,2,5-hexanetriol, 1,3-butanediol, 1,4-butanediol, 2,2-(4,4'-dihydroxyphenyl)propane (bisphenol A), 4,4'-dihydroxyphenylmethane (bisphenol F), and pentaerythritol; and polyoxytetramethylene oxide. From the viewpoint of achieving better effects of the present invention, the specific polyol preferably includes a polyether diol obtained by adding the above oxide to bisphenol A, and more preferably includes a polyether diol obtained by adding ethylene oxide to bisphenol A.

[0026] From the viewpoint of achieving better effects of the present invention, the specific polyol preferably contains a polyether polyol having a hydroxyl value of 200 to 400 mgKOH / g, more preferably a polyether diol obtained by adding the above oxide to bisphenol A and having a hydroxyl value of 200 to 400 mgKOH / g, and even more preferably a polyether diol obtained by adding ethylene oxide to bisphenol A and having a hydroxyl value of 200 to 400 mgKOH / g.

[0027] (Specific polyol content) From the viewpoint of achieving better effects of the present invention, the content of the specific polyol is preferably 10 to 60 parts by mass, more preferably 20 to 40 parts by mass, relative to 100 parts by mass of the polycarbonate polyol (total amount).

[0028] [Polyisocyanate] In the present invention, the specific composition includes a polyisocyanate. The polyisocyanate is not particularly limited as long as it has a plurality of isocyanate groups in one molecule. Examples of polyisocyanates include aromatic polyisocyanates such as tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), phenylene diisocyanate, xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), tolidine diisocyanate (TODI), and naphthalene diisocyanate (NDI); hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate, norbornane diisocyanate methyl (NBDI), transcyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), H6XDI (hydrogenated XDI), and H 12 Examples include aliphatic polyisocyanates such as MDI (hydrogenated MDI) and H6TDI (hydrogenated TDI); polyisocyanate compounds such as polymethylene polyphenylene polyisocyanate, such as polymeric MDI; carbodiimide-modified polyisocyanates of these isocyanate compounds; isocyanurate-modified polyisocyanates of these isocyanate compounds; and urethane prepolymers obtained by reacting these isocyanate compounds with general polyol compounds. These polyisocyanates may be used alone or in combination of two or more.

[0029] (Polymeric MDI) Polymeric MDI is generally a mixture of monomeric MDI (represented by the structural formula below, where n is 0) with various isomer contents and polynuclear MDI (represented by the structural formula below, where n is 1 or more) with several structures. Monomeric MDI generally refers to diphenylmethane diisocyanate containing an isomer represented by the following structural formula (where n is 0), and is composed primarily of 4,4'-diphenylmethane diisocyanate. [ka]

[0030] From the viewpoint of achieving better effects of the present invention, the polyisocyanate preferably contains polymeric MDI. The isocyanate group content of the polymeric MDI can be, for example, 20 to 40% by mass of the total amount of the polymeric MDI.

[0031] (Mole equivalent ratio of isocyanate groups in polyisocyanate to all hydroxy groups in polycarbonate polyol and specific polyol) In the specific composition, the molar equivalent ratio (NCO / OH) of the isocyanate groups in the polyisocyanate to all the hydroxy groups in the polycarbonate polyol and the specific polyol is preferably 1.0 to 3.0, more preferably 1.5 to 2.5, from the viewpoint of achieving better effects of the present invention.

[0032] (water) It is preferred that the specific composition further contains water, from the viewpoint that the effect of the present invention is more excellent, the specific composition is more easily foamed, and the density of the foam of the present invention can be reduced, resulting in a reduction in weight. The water that the specific composition can further contain is not particularly limited, and examples thereof include tap water and distilled water. (Water content) When the specific composition further contains water, the content of water is preferably 0.5 to 5 parts by mass, more preferably 1.0 to 4.0 parts by mass, per 100 parts by mass of polycarbonate polyol (total amount), from the viewpoints that the effects of the present invention are more excellent, the specific composition is more easily foamed, the density of the foam of the present invention is reduced, and the weight can be reduced.

[0033] (additives) In addition to the above-mentioned components, the specific composition may further contain additives within the scope of the present invention, such as catalysts such as 1,4-azabicyclo[2.2.2]octane, foam stabilizers, fillers, fibers, adhesion promoters, surfactants, and antioxidants. The type and content of the additive can be selected appropriately.

[0034] (form) The specific composition can be prepared, for example, from a base agent that is a polyisocyanate and a curing agent (curing agent in a broad sense) that contains all components except the polyisocyanate. When the specific composition is a two-component type having the above-mentioned base agent and a curing agent in a broad sense, the curing agent in a broad sense includes polycarbonate polyol and specific polyol as a curing agent in a narrow sense that reacts with polyisocyanate.

[0035] (How to use) Examples of methods for using the specific composition include a method of mixing the above components and a method of mixing the above base agent and the above curing agent (curing agent in a broad sense).

[0036] (foam) The foams of the present invention are obtained from the specific compositions by foaming the specific compositions. The specific composition can be foamed by mixing the above-mentioned components (in the case of a two-component type, the above-mentioned base agent and the above-mentioned curing agent (curing agent in a broad sense)) in an environment where they come into contact with atmospheric moisture, for example. When the specific composition further contains water, the specific composition tends to foam. The temperature conditions when foaming the specific composition are not particularly limited, and can be, for example, 0 to 50°C.

[0037] (density) The density of the foam of the present invention is 0.1 to 0.5 g / cm from the viewpoint of achieving a more excellent effect of the present invention and reducing the weight of the foam of the present invention. 3 is preferably 0.1 to 0.3 g / cm 3 is more preferred. In this specification, the density of the foam can be measured in accordance with JIS A 9511:2017.

[0038] (chemical crosslinking) The foam of the present invention preferably contains chemical crosslinks, from the viewpoint of achieving better effects of the present invention. Chemical crosslinks generally refer to crosslinks formed between molecules by covalent bonds. In the present invention, a chemical crosslink can be formed by reacting the polycarbonate polyol and / or specific polyol with the polyisocyanate. That is, the reaction product of the polycarbonate polyol and / or specific polyol with the polyisocyanate can be crosslinked two-dimensionally or three-dimensionally by forming the chemical crosslink. From the viewpoint of achieving better effects of the present invention, the foam of the present invention preferably has a three-dimensional structure formed by the above-mentioned chemical crosslinking. From the viewpoint of achieving better effects of the present invention, the three-dimensional structure formed by chemical crosslinking is preferably formed by reacting the polycarbonate polyol and / or specific polyol with a polyisocyanate containing polymeric MDI.

[0039] [Filled tires] The inflated tire of the present invention is an inflated tire in which a cavity formed by a tire body and a rim is filled with the foam for an inflated tire of the present invention.

[0040] The inflated tire of the present invention will now be described with reference to the accompanying drawings, in which: FIG. FIG. 1 is a cross-sectional view schematically showing one embodiment of an inflated tire of the present invention. 1, an inflated tire 1 has a tire body 3 that forms the outer contour of the tire, and a rim 5. When the tire body 3 is fitted onto the rim 5, the inflated tire 1 has a circular shape. In FIG. 1, the cavity formed by the tire body 3 and the rim 5 is entirely filled with a foam for infilled tire 7. The tire body 3 has a pair of sidewall portions 9 and 11 and a tread portion 13 .

[0041] [Tire body] The tire body used in the filled tire of the present invention is not particularly limited. Examples thereof include conventionally known tire bodies. The tire body may be made of either resin or rubber. Examples of the tire body include tires for industrial vehicles such as forklifts; tires for large vehicles such as passenger cars and buses; tires for heavy machinery such as trucks and cranes; and tire bodies used in tires for wheelchairs, bicycles, and motorcycles.

[0042] [rim] The rim used in the inflated tire of the present invention is not particularly limited as long as it is compatible with various tire bodies. The rim may be, for example, a wheel rim.

[0043] [Cavity] In the inflated tire of the present invention, the cavity formed by the tire body and the rim is filled with the foam for an inflated tire of the present invention. That is, in the inflated tire of the present invention, the entire cavity formed by the tire body and the rim is filled (saturated or filled) with the foam for an inflated tire. In this respect, the inflated tire of the present invention differs from a pneumatic tire (run-flat tire) in which a part of the cavity formed by the tire body and the rim is occupied by a run-flat support body. The inflated tire of the present invention does not include a run-flat tire.

[0044] [Foam for filling tires] In the inflated tire of the present invention, the foam that fills the cavity formed by the tire body and the rim is not particularly limited as long as it is the foam for an inflated tire of the present invention.

[0045] (Manufacturing method) As a method for producing the filled tire of the present invention, for example, a tire body is combined with a rim, a pre-mixed specific composition is injected through a valve attached to the rim, the entire cavity formed by the tire body and the rim is filled with the specific composition, and the specific composition is foamed and reacted to form a foam, thereby producing the filled tire of the present invention.

[0046] The filled tire of the present invention can be used, for example, as a tire for industrial vehicles such as forklifts; a tire for large vehicles such as passenger cars and buses; a tire for heavy machinery such as trucks and cranes; or a tire for wheelchairs, bicycles, and motorcycles. [Example]

[0047] The present invention will be described in more detail below with reference to examples. The materials, amounts used, ratios, treatment details, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the following examples.

[0048] [evaluation] The following evaluations were carried out, and the results are shown in Table 1.

[0049] [Preparation of foam] The components in Table 1 below were used in the compositions (parts by mass) shown in the table. These were stirred in the air at room temperature (25°C) for 1 minute and immediately poured into a mold (open-top) of a specified shape and foamed. Foaming ceased approximately 30 seconds after foaming began. The reactants were then left to stand for 24 hours to complete the foaming and curing reactions, yielding various foams. In Table 1, the molar equivalent ratio of the isocyanate groups in the polyisocyanate to the total hydroxy groups in the polycarbonate polyol and the specific polyol is shown in the column "NCO of polyisocyanate / OH of total polyol (molar equivalent ratio)." (Foam density) Using each foam prepared as described above, the density (g / cm) of each foam was measured in accordance with JIS A 9511:2017. 3 The results are shown in the "Density" column of Table 1.

[0050] [Elastic deformation (compressive yield point)] (Preparation of test specimens for compression test measurements) Using each foam prepared as described above, a test piece for compression test (5 cm length, 5 cm width, 5 cm height) was prepared in accordance with JIS A9511:2017.

[0051] (Compression test) Using the test specimens for compression tests prepared as described above, a compression test was conducted in accordance with JIS A9511:2017 at a temperature of 23°C and a deformation rate of 5 mm / min. The stress (MPa) at the compressive yield point was measured from the compression SS curve, where the vertical axis represents compressive strength (MPa) and the horizontal axis represents compressive strain (%). The measured stress is shown in the column for compressive yield point in Table 1.

[0052] (Evaluation criteria for elastic deformation) In the present invention, when the stress at the compressive yield point measured as described above was 1.5 MPa or more, the foam was evaluated to have excellent elastic deformability against a temporary load. The greater the stress is above 1.5 MPa, the better the elastic deformability is.

[0053] [Durability] (Manufacturing of filled tires) A filled tire having a tire size of 6.50-10 was manufactured as follows. First, the rubber tire body and wheel rim were assembled. Next, the components in Table 1 below were used in the compositions (parts by mass) shown in the table, and these were mixed by stirring for 1 minute in the air at room temperature (25° C.). The composition mixed as described above was immediately injected in a liquid state into the cavity formed by the tire body and the wheel rim through a valve attached to the rim, and foaming and curing reactions were carried out at room temperature (25°C) to produce each filled tire. The entire interior of each filled tire was filled with foam.

[0054] (Driving test) Each filled tire manufactured as described above was mounted on a drum testing machine, and a load of 150% of the maximum load capacity specified by the Japan Automobile Tire Manufacturers Association (JATMA) was applied, and the running distance until a change (for example, deformation of the tire body) occurred in the test tire was measured. The results are shown as an index value, with the running distance of Comparative Example 1 being set at 100.

[0055] (Durability evaluation criteria) In the present invention, when the index value of the mileage measured as described above was 200 or more, the inflated tire was evaluated as having excellent durability (that is, having a long lifespan). The greater the index value above 200, the better the durability.

[0056] [Table 1]

[0057] [Table 2]

[0058] Details of each component shown in Table 1 are as follows: (Polycarbonate polyol) Polycarbonate polyol A: Trade name: Benebiol NL1030B, manufactured by Mitsubishi Chemical Corporation, hydroxyl value 110 mg KOH / g. Polycarbonate polyol B: Product name: Nipporan 963, manufactured by Tosoh Corporation, hydroxyl value: 56 mgKOH / g. Condensate of 3-methyl-1,5-pentanediol:1,6-hexamethylenediol = 90:10 (mass ratio) and diethyl carbonate. Number average molecular weight (Mn): 2,000. Has one hydroxyl group at each end. Polycarbonate polyol C: Product name: Kuraray Polyol C-590, manufactured by Kuraray Co., Ltd., hydroxyl value: 224 mg KOH / g, molecular weight: 500. Polycarbonate polyol C is composed of MPD (methyl pentanediol):1,6-hexanediol in a ratio of 9:1. It has one hydroxyl group at each end. Polycarbonate polyol D: Nipponlan 982R, manufactured by Tosoh Corporation, hydroxyl value 58 mg KOH / g. Polycarbonate diol. Has one hydroxyl group at each end. Polycarbonate polyol E: Duranol T5650J, manufactured by Asahi Kasei Corporation, hydroxyl value 140 mgKOH / g. This polycarbonate diol is obtained by polymerization of 1,5-pentanediol, 1,6-hexanediol, and a carbonate compound. It has one hydroxyl group at each end.

[0059] Polytetramethylene ether glycol: PTMG1000, manufactured by Mitsubishi Chemical Corporation, hydroxyl value 114 mg KOH / g Polytetramethylene ether glycol does not fall under the category of polycarbonate polyol or specific polyol.

[0060] (Polyol) Polyol 1: 1,4-butanediol, manufactured by Tokyo Chemical Industry Co., Ltd., hydroxyl value 1246 mg KOH / g. Polyol 1 is not a specific polyol. Polyol 2: Product name: BA-3U Glycol, manufactured by Nippon Nyukazai Co., Ltd., hydroxyl value: 314 mg KOH / g. 2,2-bis(4-polyoxyethyleneoxyphenyl)propane. Has one hydroxy group at each end. Polyol 2 is a specific polyol. Polyol 3: Product name: BA-10 Glycol, manufactured by Nippon Nyukazai Co., Ltd., hydroxyl value: 170 mg KOH / g. 2,2-bis(4-polyoxyethyleneoxyphenyl)propane. Has one hydroxy group at each end. Polyol 3 does not qualify as a specific polyol. Polyol 4: Trade name: Diethylene glycol, manufactured by Kanto Chemical Co., Ltd., hydroxyl value: 1058 mg KOH / g. Compound name: Diethylene glycol.

[0061] Catalyst: 1,4-azabicyclo[2.2.2]octane, manufactured by Tokyo Chemical Industry Co., Ltd. Foam stabilizer: Siloxane-polyalkylene oxide copolymer. Product name: Niax silicone L-5111, manufactured by Momentive. Water: Distilled water

[0062] (Polyisocyanate) Polyisocyanate: Millionate MR-400, manufactured by Tosoh Corporation, polymeric MDI. A mixture of monomeric MDI and its polynuclear derivatives. NCO group content: 30.4% by mass.

[0063] The results in Table 1 confirm that the foam of the present invention exhibits the desired effects. On the other hand, Comparative Example 1, in which the composition did not contain polycarbonate polyol but instead contained polytetramethylene ether glycol, Comparative Example 3, in which the composition did not contain polyol having a specified hydroxyl value, and Comparative Examples 2 and 4 to 7, in which the composition did not contain polyol having a specified hydroxyl value but instead contained polyol having a hydroxyl value other than the specified one, did not satisfy the above criteria for elastic deformability and durability against temporary load. The molar equivalent ratio of the isocyanate groups in the polyisocyanate to the total hydroxy groups in the polycarbonate polyol and specific polyol in Comparative Examples 5 to 7 (the column "NCO of polyisocyanate / OH of total polyol (molar equivalent ratio)" in Table 1) was the same as in Example 4. [Explanation of symbols]

[0064] 1 Filled tire 3 Tire body 5 rims 7. Foam for filling tires 9, 11 Side wall section 13 Tread section

Claims

1. The foam for filled tires fills a cavity formed by a tire body and a rim, and is obtained from a composition containing a polycarbonate polyol, a polyol having a hydroxyl value of 200 to 1000 mgKOH / g, and a polyisocyanate.

2. Density is 0.1 to 0.5 g / cm ３ 2. The filled tire foam of claim 1, wherein

3. 2. The filled tire foam according to claim 1, wherein the polycarbonate polyol comprises a polycarbonate polyol 1 having a hydroxyl value of 20 to 100 mgKOH / g, and a polycarbonate polyol 2 having a hydroxyl value of more than 100 mgKOH / g and not more than 250 mgKOH / g.

4. 2. The filled tire foam according to claim 1, wherein the polyol having a hydroxyl value of 200 to 1000 mgKOH / g comprises a polyether polyol having a hydroxyl value of 200 to 400 mgKOH / g.

5. 10. The filled tire foam of claim 1, wherein the polyisocyanate comprises polymeric MDI.

6. 10. The filled tire foam of claim 1, wherein the composition further comprises water.

7. 10. The filled tire foam of claim 1, comprising chemical crosslinks.

8. An inflated tire in which a cavity formed by a tire body and a rim is filled with the foam for an inflated tire according to any one of claims 1 to 7.

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