JP5863308B2 - Pneumatic tire manufacturing method - Google Patents

Description

The present invention relates to a method of manufacturing a pneumatic tire, more particularly, a pneumatic tire having surface fasteners on the tire inner surface, of a pneumatic tire which is adapted to improve the adhesion between tire inner surface and the surface fastener It relates to a manufacturing method.

  Conventionally, in order to reduce resonance noise generated in a hollow portion of a pneumatic tire, a sound absorbing material has been installed in the hollow portion. In order to facilitate attachment of such accessories such as a sound absorbing material, a pneumatic tire having a hook-and-loop fastener on the inner surface of the tire has been proposed (for example, see Patent Document 1). According to this pneumatic tire with a hook-and-loop fastener, accessories such as a sound absorbing material can be easily attached and detached as necessary.

  However, if the hook-and-loop fastener is not firmly bonded to the inner surface of the tire, problems such as attachment of a sound absorbing material and the like occur during use of the pneumatic tire. As a method of adhering a hook-and-loop fastener to the inner surface of a tire, it is known that a vulcanized adhesive rubber composition layer is sandwiched between the hook-and-loop fastener and the inner surface of the tire and vulcanized and bonded by heating during tire vulcanization. Yes. However, in the conventional vulcanization adhesion, the adhesion between the tire inner surface and the hook-and-loop fastener is not necessarily sufficient, and it has been required to improve the adhesion strength to a level higher than the conventional level.

JP 2006-44503 A

An object of the present invention is the pneumatic tire having surface fasteners on the tire inner surface, the adhesion between tire inner surface and the surface fastener to provide a manufacturing method of a pneumatic tire which is adapted to improve the conventional level or higher is there.

The method of manufacturing a pneumatic tire with a hook-and-loop fastener according to the present invention that achieves the above object provides a plurality of engagement elements on one surface of a base material portion, and a plurality of anchor elements on the other surface of the base material portion. Of a pneumatic tire in which a base portion of the hook-and-loop fastener is bonded to the tire inner surface so that the engagement element is located on the tire lumen side and the anchor element faces the tire inner surface . In the production method , a vulcanized adhesive layer made of an adhesive rubber composition containing a radical initiator (x) is interposed between the base material portion and the tire inner surface, and the height of the anchor element is set to the vulcanized adhesive layer. The adhesive rubber composition contains the radical initiator (x) and the modified rubber composition (A) or (B), and the modified rubber composition (A) contains oxygen. Nitrochi stable at room temperature below The modified rubber composition (B) comprises a modified butyl rubber (1) obtained by reacting a compound (a) having a free radical in the molecule, a radical initiator (b) and a co-crosslinking agent (c) with butyl rubber. The co-crosslinking agent (c) is blended with the modified butyl rubber (2) obtained by reacting the compound (a) and the radical initiator (b) with butyl rubber.

The pneumatic tire of the present invention has a hook-and-loop fastener provided with a plurality of engaging elements on one surface of a base material portion, and a vulcanized adhesive layer interposed so that the engaging elements are located on the tire lumen side. Since the vulcanized adhesive layer is composed of an adhesive rubber composition containing a radical initiator (x), the adhesive rubber composition is crosslinked with the radical initiator (x), Since it is vulcanized and bonded to the tire inner surface and the hook-and-loop fastener, the adhesion between the tire inner surface and the hook-and-loop fastener can be improved beyond the conventional level. Here, the adhesive rubber composition contains a radical initiator (x) and a modified rubber composition (A) or (B). Since the modified rubber compositions (A) and (B) are both crosslinked by heating in the presence of the radical initiator (x), they are crosslinked at the time of vulcanization of the unvulcanized tire, and the tire inner surface and the hook-and-loop fastener Therefore, the hook-and-loop fastener can be bonded to the tire inner surface with an adhesive strength higher than the conventional level. The hook-and-loop fastener has a plurality of anchor elements on the surface of the base portion facing the tire inner surface, and the height of the anchor elements is made smaller than the thickness of the vulcanized adhesive layer.

It is preferable that the number average molecular weight of pre-Symbol denaturation rubber composition (A) and (B) is from 70,000 to 110,000. By making the number average molecular weights of the modified rubber compositions (A) and (B) within such a range, the adhesion between the tire inner surface and the hook-and-loop fastener can be improved over a long period of time.

The modified rubber compositions (A) and (B) preferably have a Mooney viscosity (ML _{1 +} 4/100 ° C.) based on JIS K6300 of 30 to 55. By setting the Mooney viscosity of the modified rubber compositions (A) and (B) within such a range, the processability is ensured and the wettability to the surface fastener is improved. Can be improved over a long period of time.

  The radical initiator (x) is preferably an organic peroxide or an azo compound. Moreover, it is preferable that the said adhesive rubber composition contains 30-80 weight part of reinforcing fillers with respect to 100 weight part of rubber components in an adhesive rubber composition. The thickness of the vulcanized adhesive layer is preferably from 0.3 mm to 4.0 mm.

Further, the base material portion may have a plurality of small holes penetrating in the thickness direction, and a part of the vulcanized adhesive layer may be present in the small holes and on the surface opposite to the base material portion to form a protrusion. .

  The method for producing a pneumatic tire according to the present invention includes an unvulcanized adhesive layer made of an adhesive rubber composition containing the radical initiator (x) on the inner surface of an unvulcanized tire, and the engagement element on the inner side in the tire radial direction. The above-described pneumatic fastener-equipped pneumatic tire is manufactured by arranging the base portion of the hook-and-loop fastener so that is positioned on the tire lumen side and vulcanizing the unvulcanized tire.

  Here, the unvulcanized adhesive layer can be bonded in advance to the base material surface opposite to the engaging element of the surface fastener and disposed on the inner surface of the unvulcanized tire.

1 is a meridian half cross-sectional view illustrating an embodiment of a pneumatic tire to which the present invention refers . 1 is a perspective view showing an example of a hook-and-loop fastener used in an embodiment of a pneumatic tire referred to by the present invention. FIG. 3 is a cross-sectional view of a main part showing a state where the hook-and-loop fastener of FIG. 2 is vulcanized and bonded to the tire inner surface. It is a perspective view which shows the example of the hook_and_loop | surface fastener used by this invention. FIG. 5 is a cross-sectional view of an essential part showing a state where the hook-and-loop fastener of FIG. 4 is vulcanized and bonded to the tire inner surface. It is a perspective view which shows the other example of the hook-and-loop fastener used by embodiment of the pneumatic tire which this invention refers . FIG. 7 is a cross-sectional view of a main part showing a state where the hook-and-loop fastener of FIG. 6 is vulcanized and bonded to the tire inner surface.

Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings. Figure 1 is an example of an embodiment of a pneumatic tire to be referred to the present invention, the tire an example of surface fastener 2 of the present invention is used in the embodiment of a pneumatic tire for reference, the surface fastener of FIG. 3 FIG. 2 Each shows a state of being vulcanized and bonded to the inner surface.

  In FIG. 1, 1 is a tread portion, 2 is a sidewall portion, and 3 is a bead portion. A carcass layer 4 is mounted between the pair of left and right bead portions 3 and 3. The carcass layer 4 is folded back from the inside to the outside of the tire around a bead core 5 disposed in each bead portion 3. Further, an inner liner layer 6 is disposed at a position closer to the tire lumen than the carcass layer 4. On the other hand, a plurality of belt layers 7 are embedded on the outer peripheral side of the carcass layer 4 in the tread portion 1.

  In the pneumatic tire, a hook-and-loop fastener 10 is installed in a region corresponding to the tread portion 1 of the tire inner surface S. As shown in FIG. 3, the hook-and-loop fastener 10 has an engagement element 12 positioned on the tire lumen side, and a vulcanized adhesive layer 9 is interposed between the base material portion 11 and the tire inner surface S. The tire inner surface S is vulcanized and bonded. As shown in FIG. 2, the hook-and-loop fastener 10 has a structure in which a plurality of engagement elements 12 are provided on a surface 11 a on the tire lumen side of a base material portion 11 having a sheet shape. The engaging elements 12 are arranged in a row along the tire circumferential direction C, and a plurality of rows are arranged along the tire width direction W. The shape of the engagement element 12 is not particularly limited. For example, as shown in the figure, the tip portion branches and a T-shape or hook shape (two-step hook shape extending in the surface direction of the hook-and-loop fastener 10). Included).

  On the other hand, accessories such as a sound absorbing material 20 are attached to the hook-and-loop fastener 10 as necessary. For example, when the sound absorbing material 20 is made of polyurethane foam, the sound absorbing material 20 can be directly engaged with the hook-and-loop fastener 10 by using the network structure of the polyurethane foam. Of course, you may make it attach the other hook-and-loop fastener which can be engaged with the hook-and-loop fastener 10 to an accessory. Examples of the accessory include a temperature sensor and a transponder in addition to the sound absorbing material 20. Moreover, the installation place in the tire inner surface S of the hook-and-loop fastener 10 can be arbitrarily selected according to the kind of attachment.

  Moreover, in the said pneumatic tire, although the height from the base-material surface of the engagement element 12 is not specifically limited, For example, it is good to set it as 0.5 mm-5.0 mm. By setting the height of the engagement element 12 in such a range, it is possible to sufficiently secure the attachment strength of the accessory such as the sound absorbing material 20 to the hook-and-loop fastener 10.

  In the present invention, the thickness of the vulcanized adhesive layer 9 is not particularly limited, but is preferably 0.3 mm or more and 4.0 mm or less. When the thickness of the vulcanized adhesive layer 9 is less than 0.3 mm, the vulcanized adhesive action cannot be sufficiently obtained. On the other hand, if the thickness of the vulcanized adhesive layer 9 exceeds 4.0 mm, workability is deteriorated and heat is hardly transmitted during vulcanization.

FIG. 4 shows an example of a hook-and-loop fastener used in the present invention, and FIG. 5 shows a state in which the hook-and-loop fastener of FIG. 4 and 5, the same components as those in FIGS. 2 and 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In FIG. 4, the hook-and-loop fastener 10 is provided with a plurality of engagement elements 12 on a surface 11 a on the tire lumen side of the base material portion 11, while a plurality of anchor elements 13 are provided on the other surface 11 b of the base material portion 11. It has a provided structure. The anchor elements 13 are arranged in a row along the tire circumferential direction C, and a plurality of rows are arranged along the tire width direction W. The shape of the anchor element 13 is not particularly limited. For example, the anchor element 13 may have a T-shape extending in the surface direction of the hook-and-loop fastener 10 by branching the tip as illustrated. Since these anchor elements 13 are embedded in the vulcanized adhesive layer 9 and adhered to the inner liner layer 6 of the tire inner surface S, the adhesive force of the hook-and-loop fastener 10 to the vulcanized adhesive layer 9 and the tire inner surface S can be improved. .

In the present invention, the height of the anchor element 13, you less than the thickness of the vulcanizing adhesion layer 9 described above. By making the height of the anchor element 13 smaller than the thickness of the vulcanized adhesive layer 9, the anchor element can be prevented from biting into the inner liner layer.

FIG. 6 shows still another example of the hook-and-loop fastener used in the embodiment of the pneumatic tire referred to by the present invention, and FIG. 7 shows a state in which the hook-and-loop fastener of FIG. 6 and 7, the same components as those in FIGS. 2 and 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 6, the hook-and-loop fastener 10 used in the pneumatic tire of the present invention is preferably formed with a plurality of small holes 14 penetrating the base material portion 11. The shape of the small hole 14 is not particularly limited, and may be, for example, a circle, an ellipse, or a polygon. By providing the small holes 14 in the base material portion 11 of the hook-and-loop fastener 10 in this way, when the hook-and-loop fastener 10 is vulcanized and bonded to the tire inner surface S, the small holes 14 function as an air passage during tire vulcanization. Further, it is possible to suppress the formation of air between the hook-and-loop fastener 10 and the tire inner surface S, and to improve the adhesiveness of the hook-and-loop fastener 10. Moreover, when the small holes 14 are provided in the base material portion 11 of the hook-and-loop fastener 10, the bonding area of the hook-and-loop fastener 10 is increased, and as shown in FIG. 7, a part of the vulcanized adhesive layer 9 has the small holes 14. Since it is vulcanized in a state of flowing out to the surface on the opposite side of the base material portion 11 to form the anchor-shaped protrusion 15, the adhesiveness of the hook-and-loop fastener 10 can be further improved.

The diameter of the small holes 14 is 0.1 mm to 1.5 mm, and the number of small holes 14 per 1 cm ² of unit area of the base material portion 11 is preferably 4 to 100. By selecting such dimensions and density, it is possible to sufficiently secure the effect of suppressing air accumulation and the effect of increasing the adhesion area. If the diameter of the small holes 14 is less than 0.1 mm, the rubber of the vulcanized adhesive layer 9 is difficult to enter the small holes 14, so that the effect of increasing the adhesion area and the anchor effect cannot be sufficiently obtained. If it exceeds 5 mm, a large amount of rubber in the vulcanized adhesive layer 9 flows out from the small holes 14, which hinders the engagement effect of the engagement elements 12. Moreover, it is not possible to number of small holes 14 is obtained sufficiently increasing effect and anchor effect of the adhesive area is less than 4 / cm ^2, the stiffness of 100 to reverse / cm ² by weight, the base portion 11 May decrease, and the base material portion 11 may be distorted during tire vulcanization.

  6 and 7 show an example in which a plurality of engaging elements 12 and small holes 14 are formed in the base material portion 11 of the hook-and-loop fastener 10. The engaging element 12 and the anchor element 13 and the small hole 14 can be formed.

  In the present invention, the vulcanized adhesive layer 9 is interposed between the tire inner surface S and the hook-and-loop fastener 10 to firmly bond the hook-and-loop fastener 10 to the tire inner surface S. The vulcanized adhesive layer 9 is formed by molding a rubber molded body made of an adhesive rubber composition containing the radical initiator (x), and an unvulcanized tire in which the rubber molded body is interposed between the tire inner surface and the surface fastener. It is formed by forming green and vulcanizing it.

  The adhesive rubber composition constituting the vulcanized adhesive layer 9 includes a radical initiator (x) and a modified rubber composition (A) or (B). Since the modified rubber compositions (A) and (B) are both crosslinked by heating in the presence of the radical initiator (x), they are crosslinked at the time of vulcanization of the unvulcanized tire, and the tire inner surface and the hook-and-loop fastener Therefore, the hook-and-loop fastener can be bonded to the tire inner surface with an adhesive strength higher than the conventional level.

  In the present invention, an organic peroxide or an azo compound can be used as the radical initiator (x). Examples of the organic peroxide include benzoyl peroxide, t-butylperoxybenzoate, dicumyl peroxide, t-butylcumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di- -T-butylperoxyhexane, 2,5-dimethyl-2,5-di-t-butylperoxy-3-hexyne, 2,4-dichloro-benzoyl peroxide, di-t-butylperoxy-di- Isopropylbenzene, 1,1-bis (t-butylperoxy) -3,3,5-trimethyl-cyclohexane, n-butyl-4,4-bis (t-butylperoxy) valerate, 2,2-bis ( Examples thereof include t-butylperoxy) butane.

  Examples of the azo compound include azodicarbonamide, azobisisobutyronitrile, 2,2'-azobis- (2-amidinopropane) dihydrochloride, dimethyl 2,2'-azobis (isobutyrate), azobis-cyankichi. Azo such as herbic acid, 1,1'-azobis- (2,4-dimethylvaleronitrile), azobismethylbutyronitrile, 2,2'-azobis- (4-methoxy-2,4-dimethylpareronitrile) A system radical initiator can be illustrated.

  The compounding amount of the radical initiator (x) is preferably 0.05 to 15 parts by weight, more preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the rubber component in the adhesive rubber composition.

  In the present invention, the modified rubber compositions (A) and (B) both have a number average molecular weight of preferably 70,000 to 110,000, more preferably 80000 to 110,000. By setting the number average molecular weight of the modified rubber composition within such a range, the mobility of rubber molecules during vulcanization is increased, so that the adhesion between the tire inner surface and the surface fastener is further improved. For this reason, adhesiveness can be improved over a long period of time. If the number average molecular weight of the modified rubber composition is less than 70,000, the peel strength may decrease. On the other hand, when the number average molecular weight of the modified rubber composition exceeds 110,000, the rubber attachment deteriorates. That is, the fracture mode when the bonded tire inner surface and the hook-and-loop fastener are peeled down reduces the ratio of the bonded surface where the adhesive layer breaks the material. Thereby, there exists a possibility that the adhesiveness over a long period may fall. The number average molecular weight of the modified rubber composition (B) is defined as the number average molecular weight of the modified rubber obtained by mixing the co-crosslinking agent (c) with the corresponding modified butyl rubber (2) and reacting with heat treatment. The number average molecular weight of the modified rubber composition is measured by gel permeation chromatography (GPC) in terms of standard polystyrene.

In the present invention, the Mooney viscosity (ML _{1 +} 4/100 ° C.) of the modified rubber compositions (A) and (B) is preferably 30 to 55, more preferably 32 to 52. By setting the Mooney viscosity of the modified rubber composition within such a range, good processability is ensured and wettability to the surface fastener is improved, and the adhesion between the tire inner surface and the surface fastener is maintained for a long period of time. It is possible to improve over the range. If the Mooney viscosity of the modified rubber composition is less than 30, the processability may deteriorate. On the other hand, when the Mooney viscosity of the modified rubber composition exceeds 55, the wettability to the hook-and-loop fastener is lowered and the rubber attachment is deteriorated. For this reason, the fracture mode when the tire inner surface and the hook-and-loop fastener are peeled off has a low ratio of the adhesive surface where the adhesive layer breaks down the material, and there is a risk that the adhesiveness over a long period of time will decrease. The Mooney viscosity of the modified rubber composition (B) is the Mooney viscosity of the modified rubber obtained by mixing the co-crosslinking agent (c) with the corresponding modified butyl rubber (2) and reacting with heat treatment. The Mooney viscosity (ML _{1 +} 4/100 ° C.) of the modified rubber composition is measured at 100 ° C. based on JIS K6300.

  The modified rubber composition (A) comprises a compound (a) (hereinafter referred to as “compound (a)”) having a nitroxide free radical that is stable at room temperature in the presence of oxygen in butyl rubber, a radical initiator ( It consists of a modified butyl rubber (1) reacted with b) and a co-crosslinking agent (c). The production method of the modified butyl rubber (1) is not particularly limited, but for example, the following method is preferred. First, the modified butyl rubber (2) obtained by grafting the compound (a) onto the butyl rubber is prepared by reacting the butyl rubber with the compound (a) and the radical initiator (b). The modified butyl rubber (1) capable of peroxide crosslinking is prepared by reacting the modified butyl rubber (2) with a co-crosslinking agent (c).

  The modified rubber composition (B) is composed of a composition obtained by blending the butyl rubber with the modified butyl rubber (2) obtained by reacting the compound (a) and the radical initiator (b) with the co-crosslinking agent (c). When this modified rubber composition (B) is heat-treated, the reaction between the modified butyl rubber (2) and the co-crosslinking agent (c) proceeds simultaneously with peroxide crosslinking.

（上記式（３）〜（８）において、Ｒは炭素数１〜３０のアルキル基、アルキレン基、アリール基、アリル基、ビニル基、カルボキシル基、カルボニル基含有基、エステル基、エポキシ基、イソシアネート基、ヒドロキシ基、チオール基、チイラン基、アミノ基、アミド基、イミド基、ニトロ基、ニトリル基、チオシアン基、シリル基、アルコキシシリル基、及びこれらの官能基を含む有機基から選ばれるいずれかを表す。） Examples of the compound (a) having a nitroxide free radical which is stable at room temperature in the presence of oxygen used in the present invention in the molecule include 2,2,6,6-tetramethyl- represented by the following formula (1), for example. 1-piperidinyloxy (hereinafter sometimes referred to as “TEMPO”), 4-oxo-2,2,6,6-tetramethyl-1-piperidinyloxy represented by the following formula (2), etc. Is exemplified. Examples of the compound (a) include compounds having a substituent at the 4-position of TEMPO represented by the following formulas (3) to (8).

(In the above formulas (3) to (8), R is an alkyl group having 1 to 30 carbon atoms, alkylene group, aryl group, allyl group, vinyl group, carboxyl group, carbonyl group-containing group, ester group, epoxy group, isocyanate. Group, hydroxy group, thiol group, thiirane group, amino group, amide group, imide group, nitro group, nitrile group, thiocyan group, silyl group, alkoxysilyl group, and any organic group containing these functional groups Represents.)

  Examples of the carbonyl group-containing group include residues of cyclic acid anhydrides such as succinic anhydride, maleic anhydride, glutaric anhydride, and phthalic anhydride. In the above formula (3), R may be a halogen such as chlorine or bromine.

  Examples of the compound (a) represented by the above formula (3) include 4-methyl TEMPO, 4-ethyl TEMPO, 4-phenyl TEMPO, 4-chloro TEMPO, 4-hydroxy TEMPO, 4-amino TEMPO, 4-carboxyl TEMPO. 4-isocyanate TEMPO and the like. Examples of the compound (a) represented by the above formula (4) include 4-methoxy TEMPO, 4-ethoxy TEMPO, 4-phenoxy TEMPO, 4-TEMPO-glycidyl ether, 4-TEMPO-thioglycidyl ether and the like. .

  Examples of the compound (a) represented by the above formula (5) include 4-methylcarbonyl TEMPO, 4-ethylcarbonyl TEMPO, 4-benzoyl TEMPO and the like. Examples of the compound (a) represented by the above formula (6) include 4-acetoxy TEMPO, 4-ethoxycarbonyl TEMPO, 4-methacrylate TEMPO, 4-benzoyloxy TEMPO and the like.

  Examples of the compound (a) represented by the above formula (7) include 4- (N-methylcarbamoyloxy) TEMPO, 4- (N-ethylcarbamoyloxy) TEMPO, 4- (N-phenylcarbamoyloxy) TEMPO, and the like. Illustrated. Examples of the compound (a) represented by the above formula (8) include methyl (4-TEMPO) sulfate, ethyl (4-TEMPO) sulfate, and phenyl (4-TEMPO) sulfate.

（上記式（９）（１０）において、Ｒは、炭素数１〜３０のアルキル基、アリール基、アリル基、ビニル基、アルコキシ基、カルボキシル基、カルボニル基含有基、エステル基、エポキシ基、グリシジル基、イソシアネート基、ヒドロキシ基、チオール基、チイラン基、チオグリシジル基、アミノ基、アミド基、イミド基、カルバモイル基、ニトロ基、ニトリル基、チオシアン基、シリル基、アルコキシシリル基、及びこれらの官能基を含む有機基から選ばれるいずれかを表す。） Furthermore, as compound (a), it is in the 3rd position of 2,2,5,5-tetramethyl-1-pyrrolidinyloxy (hereinafter sometimes referred to as “PROXYL”) represented by the following formula (9). A compound having a substituent, substituted at the 3-position of 2,2,5,5-tetramethyl-3-pyrrolin-1-oxy (hereinafter sometimes referred to as “PRYXYL”) represented by the following formula (10) And compounds having a group.

(In the above formulas (9) and (10), R is an alkyl group having 1 to 30 carbon atoms, aryl group, allyl group, vinyl group, alkoxy group, carboxyl group, carbonyl group-containing group, ester group, epoxy group, glycidyl. Group, isocyanate group, hydroxy group, thiol group, thiirane group, thioglycidyl group, amino group, amide group, imide group, carbamoyl group, nitro group, nitrile group, thiocyan group, silyl group, alkoxysilyl group, and their functions Represents any one selected from organic groups containing groups.)

Examples of the compound (a) represented by the above formula (9) include 3-amino-PROXYL, 3-hydroxy-PROXYL, 3-isocyanate-PROXYL, 3-carboxyl-PROXYL, 3-PROXYL-glycidyl ether, 3- Examples include PROXYL-thioglycidyl ether, 3-carbamoyl-PROXYL and the like. Examples of the compound (a) represented by the above formula (10) include 3-amino-PRYXYL, 3-hydroxy-PRYXYL, 3-isocyanate-PRYXYL, 3-carboxyl-PRYXYL, 3-PRYXYL-glycidyl ether, 3- PRYXYL-thioglycidyl ether, 3-carbamoyl-PRYXYL and the like are exemplified. Examples of other compounds (a) are as follows.

  The amount of the compound (a) used in the present invention is not particularly limited, but is preferably 0.001 to 0.5 mol, more preferably 0.005 to 0.1 mol, relative to 100 g of butyl rubber. It is good to. If the amount of compound (a) added is small, the amount of modification of butyl rubber may be low, and if it is large, peroxide crosslinking may not proceed.

  In the present invention, the compound (a) described above can be introduced into the molecular chain of butyl rubber by adding the radical initiator (b). As the radical initiator (b), any radical initiator can be used. Specifically, benzoyl peroxide, t-butylperoxybenzoate, dicumyl peroxide, t-butylcumyl peroxide, di-t -Butyl peroxide, 2,5-dimethyl-2,5-di-t-butylperoxyhexane, 2,5-dimethyl-2,5-di-t-butylperoxy-3-hexyne, 2,4- Dichloro-benzoyl peroxide, di-t-butylperoxy-di-isopropylbenzene, 1,1-bis (t-butylperoxy) -3,3,5-trimethyl-cyclohexane, n-butyl-4,4- Bis (t-butylperoxy) valerate, 2,2-bis (t-butylperoxy) butane, diisobutyl peroxide, cumylpa Oxyneodecanate, di-n-propylperoxydicarbonate, diisopropylperoxydicarbonate, di-sec-butylperoxydicarbonate, 1,1,3,3-tetramethylbutylperoxyneodecanate, di ( 4-t-butylcyclohexyl) peroxydicarbonate, 1-cyclohexyl-1-methylethylperoxyneodecanate, di (2-ethoxyethyl) peroxydicarbonate, di (2-ethoxyhexyl) peroxydicarbonate, t-hexylperoxyneodecanate, dimethoxybutylperoxydicarbonate, t-butylperoxyneodecanate, t-hexylperoxypiparate, t-butylperoxypiparate, di (3,5,5-trimethyl) Hexanoyl) peroxa , Di-n-octanoyl peroxide, dilauroyl peroxide, distearoyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, disuccinic acid peroxide, 2,5 -Dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane, t-hexylperoxy-2-ethylhexanoate, di (4-methylbenzoyl) peroxide, t-butylperoxy-2- Illustrate ethyl hexanoate, di (3-methylbenzoyl) peroxide and benzoyl (3-methylbenzoyl) peroxide and dibenzoyl peroxide, dibenzoyl peroxide, t-butyl peroxyisobutyrate, etc. Can do.

  Moreover, you may use what can be decomposed | disassembled at low temperature by the effect | action of a redox catalyst. Typical examples include dibenzoyl peroxide, paramentane hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide. An oxide etc. can be illustrated.

  Furthermore, azodicarbonamide, azobisisobutyronitrile, 2,2'-azobis- (2-amidinopropane) dihydrochloride, dimethyl 2,2'-azobis (isobutyrate), azobis-cyanvaleric acid, 1,1 Azo radical initiators such as' -azobis- (2,4-dimethylvaleronitrile), azobismethylbutyronitrile, 2,2'-azobis- (4-methoxy-2,4-dimethylpareronitrile) It can be illustrated.

  By adding these radical initiators (b) to the reaction system (mixed system, contact system), a carbon radical can be generated in the butyl rubber, and the compound (a) having a stable free radical reacts with the carbon radical. By doing so, a modified butyl rubber is obtained. The radical initiator (x) and the radical initiator (b) described above are independent of each other, and the types of compounds may be the same or different.

  Although there is no restriction | limiting in particular in the addition amount of the radical initiator (b) used in this invention, Preferably it is 0.001-0.5 mol with respect to 100 g of butyl rubber, More preferably, it is 0.005-0.2 mol. Good. If the amount of the radical initiator (b) added is too small, the amount of hydrogen atoms withdrawn from the butyl rubber chain may be low, and conversely if too large, the main chain of butyl rubber may be decomposed and the molecular weight may be greatly reduced.

  In the present invention, by adding the co-crosslinking agent (c), it reacts with the above-mentioned modified butyl rubber and performs a crosslinking reaction during peroxide crosslinking. The co-crosslinking agent (c) is not particularly limited, but a radical polymerizable monomer having a bifunctional or higher functionality and / or a radical polymerizable monomer having an alkoxysilyl group can be used. In particular, vulcanization obtained by constituting a modified rubber composition (A) or (B) by simultaneously reacting or blending a radical polymerizable monomer having bifunctionality or higher with a radical polymerizable monomer having an alkoxysilyl group. The modulus and breaking strength of the adhesive layer can be improved, and the durability is improved.

  Examples of the bifunctional or higher radical polymerizable monomer include, for example, ethylene di (meth) acrylate (herein, the expression ethylene di (meth) acrylate means both ethylene dimethacrylate and ethylene diacrylate, hereinafter the same), trimethylol. Propane tri (meth) acrylate, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolmethanetetra (meta ) Acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, ethoxylated trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate , Ethoxylated trimethylolpropane tri (meth) acrylate, propoxylated trimethylolpropane (meth) acrylate, propoxylated glyceryl (meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, di Pentaerythritol penta (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, polysiloxane di (meth) acrylate, various urethane (meth) acrylates, various metal (meth) acrylates, polypropylene glycol di (meth) acrylate, N, N'-phenylenedimaleimide, bismaleimidediphenylmethane, N, N'-phenylenediacrylamide, divinylbenzene, triallyl isocyanurate And the like. Among these, acrylates containing an electron withdrawing group (for example, carbonyl group (ketone, aldehyde, ester, carboxylic acid, carboxylate, amide), nitro group, cyano group, etc.) in the molecule are preferable from the viewpoint of increasing the modification rate.

  The amount of the bifunctional or higher radical polymerizable monomer added is not particularly limited, but is preferably 0.001 to 0.5 mol, more preferably 0.005 to 0, for example, with respect to 100 g of butyl rubber. .2 mol is recommended. If the addition amount of the bifunctional or higher radical polymerizable monomer is too small, the cross-linking of the modified butyl rubber may not proceed, and conversely if too large, the physical properties of the cross-linked product may be deteriorated.

The radically polymerizable monomer having an alkoxysilyl group is preferably represented by the following formula (11).
Si (OR ⁷ ) _4-n (R ⁶ -A) _n (11)
(In formula (11), R ⁶ and R ⁷ are each independently a hydrocarbon group, A is a radical polymerizable group, and n is an integer of 1 to 3)

Here, when n is 2 or 3, R ⁶ may be different from each other. Preferred examples of R ⁶ include alkyl groups such as methyl, ethyl, propyl, hexyl, dodecyl and octadecyl, cycloalkyl groups such as cyclopropyl and cyclohexyl, and aryl groups such as phenyl and benzyl.

Further, R ⁷ when n is 1 or 2 may be different from each other. Examples of such R ⁷ include alkyl groups such as methyl, ethyl, propyl, hexyl, dodecyl and octadecyl, cycloalkyl groups such as cyclopropyl and cyclohexyl, aryl groups such as phenyl and benzyl, polyethylene glycol, polypropylene glycol and the like. Preferred examples include polyoxyalkylene groups.

  Further, the radical polymerizable groups A when n is 2 or 3 may be different from each other. Preferred examples of such radical polymerizable group A include a vinyl group, an allyl group, a styryl group, a (meth) acryloxy group, a (meth) acrylamide group, a halogenated vinyl group, and an acrylonitrile group. Among them, those containing an electron withdrawing group (a carbonyl group, a halogen, a cyano group, etc.) are more preferable. Of these, a (meth) acryloxy group is particularly preferred.

  Examples of the radical polymerizable monomer having an alkoxysilyl group include vinylmethoxysilane, vinyltrimethoxysilane, vinylethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ Preferred examples include -methacryloxypropyldimethylmethoxysilane, γ-acryloxypropylmethyldiethoxysilane, γ-acryloxypropyldimethylethoxysilane, γ-acryloxypropyltriethoxysilane, N- (propyltriethoxysilane) maleimide and the like. be able to.

  Moreover, you may use what hydrolyzed and condensed the radically polymerizable monomer which has an alkoxy silyl group as a co-crosslinking agent (c). For example, an oligomer having a radically polymerizable group with a silicone oil type coupling agent having two or more repeating units of a siloxane bond and having an alkoxysilyl group may be used.

  In the present invention, the addition amount of the radically polymerizable monomer having an alkoxysilyl group is not particularly limited, but is preferably 0.0001 to 0.5 mol, more preferably 0.0003 to 100 g of butyl rubber. It may be 0.2 mol. If the amount of the radically polymerizable monomer having an alkoxysilyl group is small, the effect of improving the modulus and breaking strength of the crosslinked rubber molded product cannot be obtained. Conversely, if the amount of the radically polymerizable monomer having an alkoxysilyl group is large, the radically polymerizable monomer having an excessive alkoxysilyl group may adversely affect the compression set of the crosslinked rubber molded article, which is not preferable.

  In the present invention, the modified butyl rubber can be prepared, for example, as follows. That is, the modified butyl rubber (2) is prepared by reacting a mixture of the premixed butyl rubber, the compound (a) and the radical initiator (b) by heating to a temperature of 150 to 220 ° C. in a closed kneader substituted with nitrogen. ) Is prepared. Once the temperature is lowered, the modified butyl rubber (1) is prepared by adding the co-crosslinking agent (c) to the modified butyl rubber (2) and performing nitrogen substitution again, preferably by heating to 120 to 220 ° C. To do. By performing such sequential reaction, the graft amount of the co-crosslinking agent (c) to the butyl rubber can be increased. The above reaction is preferably carried out with nitrogen substitution, but can also be carried out under conditions where oxygen is lean.

  Further, a modified rubber composition (B) containing an unreacted co-crosslinking agent (c) may be prepared by blending the co-crosslinking agent (c) with the modified butyl rubber (2).

  In the present invention, the co-crosslinking agent (c) can be blended and reacted by a general method, and may be blended simultaneously with various additives, reinforcing fillers, and crosslinking agents. The above-described modification reaction and blending and mixing can be performed using a closed kneader, a twin screw extruder, a single screw extruder, a roll, a Banbury, a kneader and the like.

  In the present invention, the modified rubber compositions (A) and (B) can contain other rubber components other than the modified butyl rubbers (1) and (2). Examples of other rubber components include natural rubber, isoprene rubber, various butadiene rubbers, various styrene-butadiene rubbers, butyl rubber, halogenated butyl rubber, chloroprene rubber, acrylic rubber, silicone rubber, fluorine rubber, epichlorohydrin rubber, styrene-isoprene-butadiene. Copolymer, ethylene-propylene-diene terpolymer, ethylene-propylene copolymer, ethylene-propylene-butene terpolymer, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene copolymer Styrene-ethylene-butene-styrene block copolymer, styrene-ethylene-propylene-styrene copolymer, acrylonitrile-butadiene copolymer, hydrogenated acrylonitrile-butadiene copolymer, polyisobutylene, Ributen, styrene -p- methylstyrene copolymer, and the like can be exemplified halogenated styrene -p- methylstyrene copolymers. The content of the modified butyl rubber (1) and (2) is preferably 5% by weight or more, more preferably 10% by weight or more, and further preferably 30 to 100% by weight in the rubber component.

  In the present invention, the adhesive rubber composition can contain a reinforcing filler. Examples of reinforcing fillers include carbon black, silica, talc, and various clays. The compounding amount of the reinforcing filler is preferably 30 to 80 parts by weight, more preferably 40 to 70 parts by weight with respect to 100 parts by weight of the rubber component in the adhesive rubber composition. By blending the reinforcing filler in such a range, the adhesive rubber strength of the vulcanized adhesive layer can be increased while ensuring the processability of the adhesive rubber composition.

  The adhesive rubber composition may contain various additives generally blended in rubber compositions such as vulcanization or crosslinking agents, vulcanization or crosslinking accelerators, various oils, anti-aging agents, and plasticizers. it can. Such an additive can be kneaded by a general method to form a composition, which can be used for vulcanization or crosslinking. As long as the amount of these additives is not contrary to the object of the present invention, a conventional general amount can be used.

  The method for producing a pneumatic tire according to the present invention includes molding a rubber molded body using the rubber composition comprising the above-described adhesive rubber composition, and using the rubber molded body as an unvulcanized adhesive layer, An unvulcanized pneumatic tire interposed between the two is green molded. The procedure for disposing the surface fastener and the unvulcanized adhesive layer on the tire inner surface is not particularly limited. For example, an unvulcanized adhesive layer made of an adhesive rubber composition can be laminated on a portion where the surface fastener on the inner surface of the unvulcanized tire is to be disposed, and the surface fastener can be overlapped on the radially inner side. Place a surface fastener at a predetermined position on the tire molding drum, laminate an unvulcanized adhesive layer on it, wind the inner liner layer that forms the inner surface of the tire, and then green the unvulcanized tire using the usual method. Can be molded. In addition, an unvulcanized adhesive layer can be bonded in advance to the base material surface opposite to the engaging element of the hook-and-loop fastener, and this can be used and disposed on the inner surface of the unvulcanized tire by the procedure described above. When the obtained unvulcanized pneumatic tire is vulcanized and molded, by the heat treatment, the peroxide crosslinking of the unvulcanized adhesive layer and the vulcanization adhesion to the tire inner surface and the hook-and-loop fastener proceed simultaneously. The adhesiveness between the inner surface and the hook-and-loop fastener can be improved beyond the conventional level.

  In the method for manufacturing a pneumatic tire according to the present invention, in order to protect the engaging element of the surface fastener, a surface rubber laminated with a protective rubber layer can be disposed on the inner surface of the unvulcanized tire. Thereby, the pressure by the bladder at the time of vulcanization can be relieved, and the deformation and / or breakage of the engagement element can be suppressed by removing the protective rubber layer after vulcanization.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further, the scope of the present invention is not limited to these Examples.

  Ten types of adhesive rubber compositions (Compositions 1 to 10) having the composition shown in Tables 1 and 2 were kneaded for 6 minutes with a 150 cc kneader and further kneaded with an 8-inch open roll.

The raw materials used in Tables 1 and 2 are shown below.
IIR: Butyl rubber, BUTYL301 manufactured by LANXESS
Modified IIR-1: Modified butyl rubber (1) having a number average molecular weight of 115,000 and a Mooney viscosity (ML _{1 +} 4/100 ° C.) of 58, prepared by the following method.
Modified IIR-2: Modified butyl rubber (2) having a number average molecular weight of 115,000 and a Mooney viscosity (ML _{1 +} 4/100 ° C.) of 58, prepared by the following method.
Modified IIR-3: Modified butyl rubber (1) having a number average molecular weight of 60,000 and a Mooney viscosity (ML _{1 +} 4/100 ° C.) of 28, prepared by the following method.
Modified IIR-4: Modified butyl rubber (1) having a number average molecular weight of 90000 and Mooney viscosity (ML _{1 +} 4/100 ° C.) of 29, prepared by the following method.
Modified IIR-5: Modified butyl rubber (2) having a number average molecular weight of 78000 and Mooney viscosity (ML _{1 +} 4/100 ° C.) of 29, prepared by the following method.
Modified IIR-6: Modified butyl rubber (1) having a number average molecular weight of 90000 and a Mooney viscosity (ML _{1 +} 4/100 ° C.) of 45, prepared by the following method.
Modified IIR-7: Modified butyl rubber (2) having a number average molecular weight of 78000 and Mooney viscosity (ML _{1 +} 4/100 ° C.) of 43, prepared by the following method.
Radical initiator (x): organic peroxide, dicumyl peroxide, Park Mill D-40 manufactured by NOF Corporation
・ Carbon black: SRF grade carbon black manufactured by Tokai Carbon ・ Stearic acid: Bead Stearic Acid YR manufactured by NOF Corporation
・ Zinc flower: Zinc flower No. 3 manufactured by Shodo Chemical Industry Co., Ltd. ・ Sulfur: Dwarf pine sulfur manufactured by Karuizawa Seisakusho Co., Ltd. ・ Vulcanization accelerator: Noxeller DM manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.
Co-crosslinking agent (c): ditrimethylolpropane tetraacrylate, SR-355 manufactured by Sartomer

Preparation of modified butyl rubber-1 350.0 g of butyl rubber (BUTYL301 manufactured by LANXESS), OH-TEMPO (4-hydroxy-2,2,6,6-tetramethylpiperidinyl-1-oxyl, LA7RD manufactured by Asahi Denka Kogyo Co., Ltd. , 32.2 g of compound (a)), 24.2 g of 1,3-bis- (t-butylperoxyisopropyl) benzene (Perkadox 14-G manufactured by Kayaku Akzo, radical initiator (b)) And placed in a closed banbury set at 60 ° C. for 10 minutes. The resulting mixture was purged with nitrogen for 5 minutes while kneading in a closed Banbury set at 100 ° C. While kneading, the temperature was raised to 165 ° C. and kneading was continued for 20 minutes. A part of the obtained polymer was dissolved in toluene, and the polymer was isolated and purified by reprecipitation operation. The purified product was analyzed by ¹ H-NMR to confirm the introduction of a TEMPO site (alkoxyamino group). The introduction rate was 0.360 mol%.

  The reaction system was once brought to 150 ° C., 11.2 g of ditrimethylolpropane tetraacrylate (SR-355 manufactured by Sartomer, co-crosslinking agent (c)), and methacrylsilane (γ-methacryloxypropyltrimethoxysilane, Shin-Etsu Chemical Co., Ltd.) 5.8 g of KBM503 manufactured and co-crosslinking agent (c) were weighed and added and kneaded with nitrogen for 5 minutes while kneading and the temperature was raised to 185 ° C. and kneaded for 15 minutes to obtain modified butyl rubber-1. .

A portion of the resulting modified butyl rubber-1 was dissolved in toluene, and the polymer was isolated and purified by reprecipitation. The purified product was used for IR analysis and ¹ H-NMR analysis. Absorption derived from the ester carbonyl was observed near 1720 cm ⁻¹ , and from ¹ H-NMR, signals derived from ditrimethylolpropane were observed near 6.39, 6.10, 5.96, 4.12, and 3.30 ppm. Observed, it was confirmed that ditrimethylolpropane tetraacrylate was introduced in a structure that left three olefins. The introduction rate was 0.084 mol%. Further, a signal derived from methacrylsilane was observed in the vicinity of 3.55 ppm, and the introduction rate was 0.015 mol%.

The number average molecular weight and Mooney viscosity (ML _{1 +} 4/100 ° C.) of the obtained modified butyl rubber-1 were measured by the following methods. The number average molecular weight of the modified butyl rubber-1 was 115,000, and the Mooney viscosity (ML _{1 +} 4/100 ° C.) was 58.

Number average molecular weight The number average molecular weight of the modified butyl rubber was measured in terms of standard polystyrene by gel permeation chromatography (GPC).

Mooney viscosity (ML _{1 +} 4/100 ° C)
The Mooney viscosity (ML _{1 +} 4/100 ° C.) of the modified butyl rubber is based on JIS K6300, using a Mooney viscometer with an L-shaped rotor (38.1 mm diameter, 5.5 mm thickness), and a preheating time of 1 minute. The measurement was performed under the conditions of a rotor rotation time of 4 minutes, 100 ° C., and 2 rpm.

Preparation of modified butyl rubber-2 350.0 g of butyl rubber (BUTYL301 manufactured by LANXESS), OH-TEMPO (4-hydroxy-2,2,6,6-tetramethylpiperidinyl-1-oxyl, LA7RD manufactured by Asahi Denka Kogyo Co., Ltd. , Compound (a)) 32.2 g, di-t-butyl peroxide (Nippon Perbutyl D, radical initiator (b)) 30.4 g, and a sealed banbury with the temperature set at 60 ° C. And mixed for 10 minutes. The resulting mixture was purged with nitrogen for 5 minutes while kneading in a closed Banbury set at 100 ° C. While kneading, the temperature was raised to 186 ° C. and kneading for 20 minutes to obtain modified butyl rubber-2.

A part of the resulting modified butyl rubber-2 was dissolved in toluene, and the polymer was isolated and purified by reprecipitation. The purified product was analyzed by ¹ H-NMR to confirm the introduction of a TEMPO site (alkoxyamino group). The introduction rate was 0.348 mol%.

When the number average molecular weight and Mooney viscosity (ML _{1 +} 4/100 ° C.) of the obtained modified butyl rubber-2 were measured by the above-described method, the number average molecular weight of the modified butyl rubber-2 was 115,000 and the Mooney viscosity (ML _{1 + 4} / 100 ° C.) was 58.

Preparation of modified butyl rubber-3 In the preparation of modified butyl rubber-1 described above, except that 350.0 g of butyl rubber (BUTYL301 manufactured by LANXESS) was replaced with 350.0 g of butyl rubber (butyl 065 manufactured by JSR), modified butyl rubber-1 Modified butyl rubber-3 was prepared in the same manner as the preparation.

A portion of the resulting modified butyl rubber-3 was dissolved in toluene, and the polymer was isolated and purified by reprecipitation. The purified product was analyzed by ¹ H-NMR to confirm the introduction of a TEMPO site (alkoxyamino group). The introduction rate was 0.410 mol%.

When the number average molecular weight and Mooney viscosity (ML _{1 +} 4/100 ° C.) of the obtained modified butyl rubber-3 were measured by the method described above, the number average molecular weight of the modified butyl rubber-3 was 60000, Mooney viscosity (ML _{1 + 4} / 100 ° C.) was 28.

Preparation of modified butyl rubber-4 In the preparation of modified butyl rubber-1 described above, a modified butyl rubber was used except that 355.0 g of butyl rubber (BUTYL301 manufactured by LANXESS) was replaced with half of 175.0 g by butyl rubber (BUTYL402 manufactured by LANXESS). Modified butyl rubber-4 was prepared in the same manner as the preparation of -1.

A portion of the resulting modified butyl rubber-4 was dissolved in toluene, and the polymer was isolated and purified by reprecipitation. The purified product was analyzed by ¹ H-NMR to confirm the introduction of a TEMPO site (alkoxyamino group). The introduction rate was 0.485 mol%.

When the number average molecular weight and Mooney viscosity (ML _{1 +} 4/100 ° C.) of the obtained modified butyl rubber-4 were measured by the above-described method, the number average molecular weight of the modified butyl rubber-4 was 90000, Mooney viscosity (ML _{1 + 4} / 100 ° C.) was 29.

Preparation of modified butyl rubber-5 In the preparation of modified butyl rubber-2 described above, a modified butyl rubber was used except that 355.0 g of butyl rubber (BUTYL301 manufactured by LANXESS) was replaced with half of 175.0 g by butyl rubber (BUTYL402 manufactured by LANXESS). -Modified butyl rubber-5 was prepared in the same manner as the preparation of -2.

A part of the resulting modified butyl rubber-5 was dissolved in toluene, and the polymer was isolated and purified by reprecipitation. The purified product was analyzed by ¹ H-NMR to confirm the introduction of a TEMPO site (alkoxyamino group). The introduction rate was 0.482 mol%.

When the number average molecular weight and Mooney viscosity (ML _{1 +} 4/100 ° C.) of the modified butyl rubber-5 obtained were measured by the above-described method, the number average molecular weight of the modified butyl rubber-5 was 78,000 and the Mooney viscosity (ML _{1 + 4} / 100 ° C.) was 29.

Preparation of modified butyl rubber-6 In the preparation of modified butyl rubber-1 described above, half of 175.0 g of butyl rubber (BUTYL301 manufactured by LANXESS) was replaced with butyl rubber (BUTYL402 manufactured by LANXESS), and carbon was changed to SAF grade. A modified butyl rubber-6 was prepared in the same manner as the modified butyl rubber-1 except that the modified butyl rubber-1 was changed.

A portion of the resulting modified butyl rubber-6 was dissolved in toluene, and the polymer was isolated and purified by reprecipitation. The purified product was analyzed by ¹ H-NMR to confirm the introduction of a TEMPO site (alkoxyamino group). The introduction rate was 0.483 mol%.

When the number average molecular weight and Mooney viscosity (ML _{1 +} 4/100 ° C.) of the obtained modified butyl rubber-6 were measured by the above-described method, the number average molecular weight of the modified butyl rubber-6 was 90000, Mooney viscosity (ML _{1 + 4} / 100 ° C) was 45.

Preparation of modified butyl rubber-7 In the above-mentioned preparation of modified butyl rubber-2, half of 170.0 g of 350.0 g of butyl rubber (LANTYS BUTYL301) was replaced with butyl rubber (LANTYS BUTYL402), and carbon was SAF grade. A modified butyl rubber-7 was prepared in the same manner as the modified butyl rubber-2 except that the modified butyl rubber-2 was changed.

A portion of the resulting modified butyl rubber-7 was dissolved in toluene, and the polymer was isolated and purified by reprecipitation. The purified product was analyzed by ¹ H-NMR to confirm the introduction of a TEMPO site (alkoxyamino group). The introduction rate was 0.480 mol%.

When the number average molecular weight and Mooney viscosity (ML _{1 +} 4/100 ° C.) of the obtained modified butyl rubber-7 were measured by the above-described method, the number average molecular weight of the modified butyl rubber-7 was 78000, Mooney viscosity (ML _{1 + 4} / 100 ° C) was 43.

  An unvulcanized tire in which a rubber molded body made of the obtained adhesive rubber composition is interposed as an unvulcanized adhesive layer, and surface fasteners A or B are arranged on the tire inner surface as shown in Tables 3 to 5 (Examples) 1 to 11 and Comparative Examples 1 and 3) were green molded. The tire structure and the tire component shown in FIG. 1 were made common to the tire size 215 / 60R16, and the type of surface fastener and the type and thickness of the vulcanized adhesive layer were varied. The surface fasteners A and B are both nylon surface fasteners having a width of 20 mm. The surface fastener A has an engagement element (height 0.8 mm) on one surface of the base portion and an anchor element (high height) on the other surface. The surface fastener B has an engaging element (height 0.8 mm) on one surface of the base material portion. The inner surface of the tire was formed of an inner liner layer made of the rubber composition shown in Table 6. In this rubber composition for an inner liner, the compounding ingredients excluding sulfur and the vulcanization accelerator were weighed, kneaded in a closed banbury, discharged at a temperature of 160 ° C., and cooled at room temperature. This masterbatch was prepared by adding and mixing sulfur and a vulcanization accelerator in a closed banbury.

  The unvulcanized tire molded as described above was inserted into a mold and vulcanized using a bladder (steam temperature 180 ° C., vulcanization time 10 minutes) to produce a pneumatic tire with a hook-and-loop fastener (Example 1 to Example 1). 6, Comparative Examples 1 and 3). In the pneumatic tire with a hook-and-loop fastener of Comparative Example 2, the hook-and-loop fastener A was attached to the inner surface of a pre-vulcanized pneumatic tire by using an adhesive (Super X manufactured by Cemedine Co.).

  The obtained pneumatic tires (Examples 1 to 11 and Comparative Examples 1 to 3) were cut out, and the peel strength between the tire inner surface and the hook-and-loop fastener was measured according to JIS K6256-1. The obtained results are shown in Tables 3 to 5 as indices with the peel strength of Comparative Example 1 as 100. It means that peeling strength is so large that this index | exponent is large.

The types of raw materials used in Table 6 are shown below.
IIR: Butyl rubber, BUTYL301 manufactured by LANXESS
・ Carbon black: GPF grade carbon black manufactured by Tokai Carbon Co., Ltd. ・ Stearic acid: Bead Stearic Acid YR manufactured by NOF Corporation
・ Oil: Aroma oil FR-120 manufactured by Air Water INC
・ Zinc flower: Zinc flower No. 3 manufactured by Shodo Chemical Co., Ltd. ・ Magnesium oxide: Kyomag 150 manufactured by Kyowa Chemical Industry
・ Petroleum resin: Mitsui Chemicals Highlets G100X
・ Sulfur: Hunmatsu sulfur manufactured by Karuizawa Seisakusho ・ Vulcanization accelerator: MBTS, Noxeller DM manufactured by Ouchi Shinsei Chemical Co., Ltd.

  As is clear from the results of Tables 3 to 5, the pneumatic tires of Examples 1 to 10 can improve the peel strength of the surface fastener with respect to the tire inner surface to a level higher than the conventional level.

  Further, as is apparent from the results in Table 3, in Comparative Example 2, the peel strength cannot be sufficiently increased because the surface fastener is attached using an existing adhesive. In Comparative Example 3, since the adhesive rubber composition does not contain the radical initiator (x), the peel strength cannot be improved.

  Next, for the pneumatic tires of Examples 6 to 10 in which the hook-and-loop fastener B was arranged, the peel strength after the durability test was evaluated by the following method.

Peel strength after durability test Examples 6 to 10 Pneumatic tires were each assembled on a standard rim, filled with air with an air pressure of 210 kPa, and attached to an indoor drum tester (drum diameter 1707 mm) in accordance with JIS D4230. A durability test was performed in which the vehicle was run for 80 hours at a speed of 4.82 kN and a speed of 80 km / hour. The pneumatic tire after the test was cut out, and the peel strength between the tire inner surface and the hook-and-loop fastener was measured according to JIS K6256-1. The obtained results are shown in Table 7 as an index with the peel strength of Example 6 as 100. The larger the index, the greater the peel strength after the durability test, which means that the adhesion between the tire inner surface and the hook-and-loop fastener is excellent for a long period of time.

  From Table 7, it was confirmed that the peel strength of the hook-and-loop fastener with respect to the tire inner surface after the tire durability test was further improved by setting the number average molecular weight of the modified rubber composition to 70000 to 110000.

DESCRIPTION OF SYMBOLS 1 Tread part 2 Side wall part 3 Bead part 4 Carcass layer 5 Bead core 6 Inner liner layer 7 Belt layer 10 Surface fastener 11 Base part 12 Engagement element 13 Anchor element 14 Small hole S Tire inner surface

Claims (9)

A hook-and-loop fastener having a plurality of engagement elements provided on one surface of the base material portion and a plurality of anchor elements provided on the other surface of the base material portion; In the method of manufacturing a pneumatic tire in which the base portion of the hook-and-loop fastener is bonded to the tire inner surface so that the anchor element faces the tire inner surface, a radical initiator ( a vulcanized adhesive layer comprising an adhesive rubber composition comprising x), the height of the anchor element being smaller than the thickness of the vulcanized adhesive layer, and the adhesive rubber composition comprising the radical initiator (X) and a modified rubber composition (A) or (B), wherein the modified rubber composition (A) has a nitroxide free radical that is stable at room temperature in the presence of oxygen in the molecule (a), Radical initiator (b) and A modified butyl rubber comprising a modified butyl rubber (1) obtained by reacting a co-crosslinking agent (c) with butyl rubber, wherein the modified rubber composition (B) is obtained by reacting the compound (a) and the radical initiator (b) with butyl rubber. (2) The co-crosslinking agent (c) is blended with the method for producing a pneumatic tire with a hook-and-loop fastener. The method for producing a pneumatic tire according to claim 1, wherein the modified rubber compositions (A) and (B) have a number average molecular weight of 70,000 to 110,000. The pneumatic rubber according to claim 1 or 2, wherein the modified rubber compositions (A) and (B) have a Mooney viscosity (ML _{1 +} 4/100 ° C) based on JIS K6300 of 30 to 55. Tire manufacturing method . The method for producing a pneumatic tire according to any one of claims 1 to 3, wherein the radical initiator (x) is an organic peroxide or an azo compound. The said adhesive rubber composition contains 30-80 weight part of reinforcing fillers with respect to 100 weight part of rubber components in this adhesive rubber composition, The any one of Claims 1-4 characterized by the above-mentioned. A method of manufacturing a pneumatic tire. The method for producing a pneumatic tire according to any one of claims 1 to 5, wherein a thickness of the vulcanized adhesive layer is 0.3 mm or greater and 4.0 mm or less. The base material portion has a plurality of small holes penetrating in the thickness direction, and a part of the vulcanized adhesive layer is present in the small holes and on the surface opposite to the base material portion to form a protrusion. The method for producing a pneumatic tire according to any one of claims 1 to 6 , wherein the pneumatic tire is produced . An unvulcanized adhesive layer made of an adhesive rubber composition containing the radical initiator (x) is formed on the inner surface of the unvulcanized tire, and a hook-and-loop fastener is positioned on the tire lumen side on the inner side in the tire radial direction. place manner, the manufacturing method of the pneumatic tire according to any one of claims 1 to 7 so as to vulcanize the unvulcanized tire. According to claim 8, wherein said the engaging elements of previously said surface fastener of non-vulcanized adhesion layer bonded to the substrate surface opposite, to place it on the inner surface of the unvulcanized tire A method of manufacturing a pneumatic tire.

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