JP6352706B2 - Surface modification method and surface modified elastic body - Google Patents

Description

The present invention relates to a surface modification method, a medical device such as a syringe gasket and a syringe for syringe having at least part of a modified surface obtained by the modification method, and a groove surface of a tire at least partly. The present invention relates to a surface-modified elastic body such as a tire.

For parts that slide while maintaining a sealed state, for example, gaskets that are integrated with the plunger of a syringe to seal the plunger and syringe, an elastic body such as rubber is used with an emphasis on liquid leakage resistance. However, there is a slight problem in slidability (see Patent Document 1). For this reason, a sliding property improving agent such as silicone oil is applied to the sliding surface, but it has been pointed out that silicone oil may adversely affect biopharmaceuticals that have recently been put on the market. On the other hand, gaskets not coated with a slidability improver are inferior in slidability, causing pulsation without smoothly pushing the plunger during administration, resulting in inaccurate injection volume, causing pain to patients, etc. Problem arises.

In order to satisfy the conflicting requirements of the liquid leakage resistance and the sliding property, a technique for coating a self-lubricating PTFE film has been proposed (see Patent Document 2). The manufacturing cost of the product increases and the application range is limited. In addition, there is a concern about reliability when a product coated with a PTFE film is applied to an application in which durability is required due to repeated sliding and the like. Furthermore, since PTFE is vulnerable to radiation, there is also a problem that sterilization by radiation cannot be performed.

In addition, application to other uses that require slidability in the presence of water is also conceivable. That is, water can be sent without loss by lowering the fluid resistance of the syringe inner surface of the prefilled syringe and the inner surface of the tube or tube for feeding water, increasing the contact angle with water, or reducing it significantly. By reducing the surface resistance of the inner and outer surfaces of the catheter tube, the catheter can be easily inserted into the body, and the guide wire can be easily passed through the catheter. By reducing the fluid resistance on the groove surface of the tire, increasing the contact angle with water, or reducing it significantly, water and snow on wet and snowy road surfaces will be better, resulting in improved grip and hydroplaning. And safety is improved. It can also be expected that dust and dust are less likely to adhere by reducing the sliding resistance of the tire sidewall and building walls and increasing the contact angle with water.

Furthermore, pressure loss when water or an aqueous solution is sent by a diaphragm such as a diaphragm pump or a diaphragm valve is reduced. It becomes easy to slip by improving the slidability of the sliding surface of the ski or snowboard. Signs are easier to see by improving the slidability of road signs and billboards and making the snow more slippery. By reducing the sliding resistance of the outer peripheral surface of the ship or increasing the contact angle with water, the resistance of water is reduced and bacteria are less likely to adhere to the outer peripheral surface. It is also possible to expect advantageous effects such as reducing the water resistance by improving the sliding property of the yarn surface of the swimsuit.

JP 2004-298220 A JP 2010-142573 A

An object of the present invention is to solve the above-mentioned problems and to provide a surface modification method for a vulcanized rubber or a thermoplastic elastomer capable of imparting economically advantageous functions such as slidability and liquid leakage resistance. . Further, the surface of a medical device such as a syringe gasket or a syringe having at least a part of the modified surface obtained by the surface modification method, a tire having at least a part of a tire groove surface or a sidewall surface. Another object is to provide a modified elastic body.

The present invention is a surface modification method using a vulcanized rubber or a thermoplastic elastomer as a modification target, the step 1 of forming a polymerization start point A on the surface of the modification target, and the polymerization start point A The step 2 is a step of growing a copolymer polymer chain by radical polymerization of two or more kinds of monomers starting from the above, the step 3 of forming a polymerization start point B on the surface of the copolymer polymer chain, and the polymerization start point B. And a step 4 of radically polymerizing a monomer having less charge bias than the two or more types of monomers to grow a polymer chain having less charge bias.

In the step 2, the two or more types of monomers are radically polymerized by irradiation with LED light of 300 to 450 nm starting from the polymerization starting point A, and the copolymer polymer chain is grown. The polymer starting point B is preferably used as a starting point for radical polymerization of the monomer having a small charge bias by irradiation with LED light of 300 to 450 nm to grow the polymer chain having a small charge bias.

In the step 1, a photopolymerization initiator A is adsorbed on the surface of the object to be modified, or LED light of 300 to 450 nm is further irradiated to form a polymerization start point A from the photopolymerization initiator A on the surface. In the step 3, the photopolymerization initiator B is adsorbed on the surface of the copolymer chain, or further irradiated with LED light of 300 to 450 nm, and polymerization is performed from the photopolymerization initiator B on the surface. It is preferable that the starting point B is formed.

The present invention is also a surface modification method using a vulcanized rubber or a thermoplastic elastomer as a modification target, wherein two or more types of monomers are added to the surface of the modification target in the presence of a photopolymerization initiator A. A step I of radical polymerization to grow a copolymer polymer chain, and radical polymerization of a monomer having a smaller charge bias than the two or more types of monomers in the presence of a photopolymerization initiator B on the surface of the copolymer polymer chain; The present invention relates to a surface modification method including a step II of growing a polymer chain with less charge bias.

In the step I, the two or more kinds of monomers are radically polymerized by irradiation with LED light of 300 to 450 nm to grow the copolymer polymer chain, and the step II includes the monomer having a small charge bias. The polymer chain is preferably grown by radical polymerization by irradiation with LED light of 300 to 450 nm so as to grow the above-mentioned polymer chain with less charge bias.

The photopolymerization initiators A and B are the same or different and are preferably a benzophenone compound and / or a thioxanthone compound.

It is preferable to perform a step of washing the object to be modified after at least one of step 2, step 4, step I, and step II.
The cleaning is preferably steam cleaning performed at 110 to 150 ° C.

The vulcanized rubber or thermoplastic elastomer preferably has an allylic carbon atom that is a carbon atom adjacent to a double bond.

The surface modification method is preferably polymerized in an inert gas atmosphere.
The surface modification method is preferably polymerized under vacuum degassing conditions.

The two or more types of monomers preferably include a monomer having a carboxyl group or a hydroxyl group and a monomer having an amino group or an amide group.

The monomer having a carboxyl group or a hydroxyl group is at least one selected from the group consisting of (meth) acrylic acid and hydroxyalkyl (meth) acrylate, and the monomer having an amino group or an amide group is dimethyl (meta It is preferably at least one selected from the group consisting of) acrylamide, diethyl (meth) acrylamide, isopropyl (meth) acrylamide, hydroxyethyl (meth) acrylamide, methoxymethyl (meth) acrylamide, and (meth) acrylamide.

It is preferable that the monomer with a small charge bias is (meth) acrylonitrile.

It is preferable that the two or more types of monomers, the monomer (liquid) having a small charge bias, or a solution thereof contain a polymerization inhibitor and polymerize in the presence of the polymerization inhibitor.

After the step 4 or the step II, it is preferable to irradiate an electron beam to the grown copolymer polymer chain and the polymer chain with little bias of charge.

It is preferable that the total polymer chain length including the copolymer polymer chain and the polymer chain with little charge bias is 10 to 50000 nm.
It is preferable that the ratio of the length of the copolymer polymer chain to the length of the polymer chain with little bias of electric charge is 50:50 to 99.9: 0.1.

The present invention relates to a surface-modified elastic body obtained by the surface modification method.
The present invention relates to a surface-modified elastic body that is required to have slidability, low friction or low water resistance in the presence of water or in a dry state obtained by the surface modification method.

The present invention relates to a surface-modified elastic body in which at least a part of a three-dimensional solid surface is modified by the surface modification method.
The surface-modified elastic body is preferably a polymer brush.

The present invention relates to a medical device having at least a part of the surface modified by the surface modification method.
The present invention relates to a syringe gasket having at least a part of the surface modified by the surface modification method.
The present invention relates to a syringe for a syringe having at least a part of the surface modified by the surface modification method.

The present invention relates to a tire having at least a part of a groove surface and / or a sidewall surface of the tire modified by the surface modification method.

According to the present invention, there is provided a surface modification method using a vulcanized rubber or a thermoplastic elastomer as a modification target, the step 1 of forming a polymerization start point A on the surface of the modification target, and the polymerization start Step 2 of radically polymerizing two or more types of monomers starting from point A to grow a copolymer polymer chain, Step 3 of forming a polymerization start point B on the surface of the copolymer polymer chain, and the polymerization start point A surface modification method comprising the step 4 of radically polymerizing a monomer having less charge bias than the two or more types of monomers starting from B to grow a polymer chain having less charge bias. Functionality such as liquid leakage resistance can be imparted. In other words, because the polymer chain with less charge bias is grown on the copolymerized polymer chain obtained by polymerizing the monomer, the slidability and liquid leakage resistance are remarkably improved. It becomes possible to improve. It is also economical.

It is an example of the side view of embodiment of the gasket for syringes. It is an example of the expanded view of the tread part of a pneumatic tire (whole figure not shown). It is an example of A1-A1 sectional drawing of FIG.

The surface modification method of the present invention is a surface modification method using a vulcanized rubber or a thermoplastic elastomer as an object to be modified, wherein the polymerization initiation point A is formed on the surface of the object to be modified; Step 2 of radically polymerizing two or more types of monomers starting from the polymerization start point A to grow a copolymer polymer chain, Step 3 of forming a polymerization start point B on the surface of the copolymer polymer chain, And a step 4 of radically polymerizing a monomer having less charge bias than the two or more kinds of monomers starting from the polymerization start point B to grow a polymer chain having less charge bias.

After preparing a copolymer polymer chain by polymerizing two or more monomers such as a monomer having a carboxyl group or a hydroxyl group, a monomer having an amino group or an amide group on the surface of a vulcanized rubber, etc., the charge bias of acrylonitrile, etc. It is possible to impart excellent slidability, liquid leakage resistance, and the like by polymerizing a monomer having a small amount and extending a polymer chain having a small charge bias to perform surface modification.

It is also possible to provide an economically advantageous modification method by building a scaffold with an appropriate copolymerized polymer chain and building a polymer chain with less charge bias on it.

In step 1, a polymerization start point A is formed on the surface of the rubber after vulcanization molding or the thermoplastic elastomer after molding (subject to be modified).
As the vulcanized rubber and the thermoplastic elastomer, those having a carbon atom adjacent to a double bond (allylic carbon atom) are preferably used.

Examples of rubbers to be modified include diene rubbers such as styrene butadiene rubber, butadiene rubber, isoprene rubber, natural rubber, and deproteinized natural rubber, and butyl rubber and halogenated butyl rubber containing isoprene units as a degree of unsaturation. Is mentioned. In the case of butyl rubber and halogenated butyl rubber, a crosslinked rubber made of triazine is preferred because the extract from the vulcanized rubber is reduced. In this case, an acid acceptor may be included, and suitable acid acceptors include hydrotalcite and magnesium carbonate.

In the case of other rubbers, sulfur vulcanization is preferred. In that case, you may add compounding agents, such as a vulcanization accelerator generally used by sulfur vulcanization, a zinc oxide, a filler, and a silane coupling agent. As the filler, carbon black, silica, clay, talc, calcium carbonate and the like can be suitably used.

The rubber vulcanization conditions may be set as appropriate, and the rubber vulcanization temperature is preferably 150 ° C. or higher, more preferably 170 ° C. or higher, and still more preferably 175 ° C. or higher.

As the thermoplastic elastomer, for example, a polymer compound having a rubber elasticity at normal temperature (thermoplastic elastomer (TPE) such as a styrene-butadiene styrene copolymer) by a collection of plastic components (hard segments) serving as a crosslinking point Etc .; a high molecular compound having rubber elasticity in which a thermoplastic component and a rubber component are mixed and dynamically crosslinked by a crosslinking agent (including a styrene block copolymer or an olefin resin and a crosslinked rubber component) And thermoplastic elastomers (TPV) such as polymer alloys).

Other suitable thermoplastic elastomers include nylon, polyester, urethane, polypropylene, and their dynamically crosslinked thermoplastic elastomers. In the case of a dynamically crosslinked thermoplastic elastomer, a material obtained by dynamically crosslinking a halogenated butyl rubber in a thermoplastic elastomer is preferable. In this case, the thermoplastic elastomer is preferably nylon, urethane, polypropylene, SIBS (styrene-isobutylene-styrene block copolymer) or the like.

The polymerization start point A is formed by, for example, adsorbing the photopolymerization initiator A on the surface of the modification target. Examples of the photopolymerization initiator A include carbonyl compounds, organic sulfur compounds such as tetraethylthiuram disulfide, persulfides, redox compounds, azo compounds, diazo compounds, halogen compounds, photoreducible dyes, among others. A carbonyl compound is preferred.

As the carbonyl compound as the photopolymerization initiator A, benzophenone and its derivatives are preferable. For example, a benzophenone compound represented by the following formula can be suitably used.

(Wherein R ^{1 to} R ⁵ and R ¹ ′ to R ⁵ ′ are the same or different and represent a hydrogen atom, an alkyl group, a halogen (fluorine, chlorine, bromine, iodine), a hydroxyl group, a primary to tertiary amino group, It represents a mercapto group or a hydrocarbon group that may contain an oxygen atom, a nitrogen atom, or a sulfur atom, and any two adjacent groups may be linked together to form a ring structure together with the carbon atoms to which they are bonded. )

Specific examples of benzophenone compounds include benzophenone, xanthone, 9-fluorenone, 2,4-dichlorobenzophenone, methyl o-benzoylbenzoate, 4,4'-bis (dimethylamino) benzophenone, 4,4'-bis ( And diethylamino) benzophenone. Among these, benzophenone, xanthone, and 9-fluorenone are particularly preferable because a polymer brush can be obtained satisfactorily.

As the benzophenone compound, a fluorobenzophenone compound can also be suitably used, and examples thereof include 2,3,4,5,6-pentafluorobenzophenone and decafluorobenzophenone represented by the following formula.

（式中、Ｒ^１１〜Ｒ^１４及びＲ^１１′〜Ｒ^１４′は、同一若しくは異なって、水素原子、ハロゲン原子、アルキル基、環状アルキル基、アリール基、アルケニル基、アルコキシ基、又はアリールオキシ基を表す。） As the photopolymerization initiator A, a thioxanthone compound can also be suitably used because it has a high polymerization rate and easily adsorbs and / or reacts with rubber or the like. For example, a compound represented by the following formula can be preferably used.

(In the formula, R ^{11 to} R ¹⁴ and R ¹¹ ′ to R ¹⁴ ′ are the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group, a cyclic alkyl group, an aryl group, an alkenyl group, an alkoxy group, or an aryloxy group. Represents.)

Examples of the thioxanthone compound represented by the above formula include thioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,3-diethylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 2-methoxythioxanthone, 1 -Chloro-4-propoxythioxanthone, 2-cyclohexylthioxanthone, 4-cyclohexylthioxanthone, 2-vinylthioxanthone, 2,4-divinylthioxanthone, 2,4-diphenylthioxanthone, 2-butenyl-4-phenylthioxanthone, 2-methoxythioxanthone , 2-p-octyloxyphenyl-4-ethylthioxanthone and the like. Among ^them, one or two of R 11 ^{to R 14} and ^R 11 ^{'~R 14',} is preferably one in particular two are substituted by an alkyl group, 2,4-Diethylthioxanthone (2,4- diethyl Thioxanthone) is more preferred.

As a method for adsorbing the photopolymerization initiator A such as a benzophenone compound or a thioxanthone compound on the surface of the object to be modified, a known method may be used. For example, for benzophenone compounds and thioxanthone compounds, the surface portion of the object to be modified is adsorbed on the surface by treatment with a solution obtained by dissolving benzophenone compounds and thioxanthone compounds in an organic solvent, A polymerization initiation point is formed by evaporating the organic solvent by drying as necessary. The surface treatment method is not particularly limited as long as the benzophenone compound solution and the thioxanthone compound solution can be brought into contact with the surface of the object to be modified. For example, the benzophenone compound solution and the thioxanthone compound Application, spraying, immersion in the solution, and the like are preferable. Further, when the surface modification is necessary only on a part of the surface, the photopolymerization initiator A may be adsorbed only on the part of the necessary surface. In this case, for example, the application of the solution, the solution Is suitable. As the solvent, methanol, ethanol, acetone, benzene, toluene, methyl ethyl ketone, ethyl acetate, THF, and the like can be used. Acetone is preferable because it does not swell the object to be modified, and is quick to dry and evaporate.

Further, after surface treatment with the benzophenone-based compound solution and the thioxanthone-based compound solution is performed on the site to be modified to adsorb the photopolymerization initiator A, it is further irradiated with light to be chemically bonded to the surface of the material to be modified. It is preferable to make it. For example, the benzophenone compound and the thioxanthone compound can be immobilized on the surface by irradiation with ultraviolet rays having a wavelength of 300 to 450 nm (preferably 300 to 400 nm, more preferably 350 to 400 nm). As shown in the following formula, in Step 1 and the immobilization, hydrogen on the rubber surface is extracted, and a covalent bond is formed between the carbon of the benzophenone C = O and the carbon on the rubber surface, and at the same time. Hydrogen bonds to C = O oxygen to form C-O-H. Further, since this hydrogen abstraction reaction is selectively performed with hydrogen at the allylic position of the reforming target, it is preferable that the rubber contains butadiene and isoprene units having allyl hydrogen.

Among them, by treating the surface of the modification target with the photopolymerization initiator A to adsorb the photopolymerization initiator A on the surface, and then irradiating the treated surface with 300 to 450 nm LED light. The polymerization initiator A is preferably formed. In particular, the surface of the modification target is subjected to a surface treatment with a benzophenone-based compound solution or a thioxanthone-based compound solution to adsorb the photopolymerization initiator A, and then further processed. It is preferable that the adsorbed photopolymerization initiator A is chemically bonded to the surface by irradiating the surface with 300 to 450 nm of LED light. If the wavelength is less than 300 nm, there is a possibility of damaging the molecule of the modification target, so that light of 300 nm or more is preferable, and from the viewpoint that the damage of the modification target is very small, it is 355 nm or more. More preferred is light. On the other hand, with light exceeding 450 nm, the polymerization initiator is difficult to activate and the polymerization reaction does not proceed easily, so light with a wavelength of 450 nm or less is preferable, and light with a wavelength of 400 nm or less is more preferable from the viewpoint of further activating the polymerization initiator. The wavelength of the LED light is particularly preferably 355 to 380 nm. LED light is suitable because it has a narrow wavelength and does not emit a wavelength other than the center wavelength. Even if a mercury lamp or the like is used to cut light of less than 300 nm using a filter, the same effect as LED light can be obtained. It is also possible.

In step 2, a copolymerized polymer chain is grown by radical polymerization of two or more monomers starting from the polymerization start point A.

The two or more types of monomers may be appropriately selected from a plurality of types of monomers. From the viewpoint of obtaining excellent slidability and liquid leakage resistance, a monomer having a carboxyl group or a hydroxyl group, and an amino group or an amide group It is preferable to use a monomer containing a monomer having In addition, for example, when using a monomer having a carboxyl group or a hydroxyl group and an amino group or an amide group, such as hydroxyethyl (meth) acrylamide, in addition to the monomer, another monomer having a carboxyl group or a hydroxyl group or an amino group or It is preferable to include a monomer having an amide group.

Examples of the monomer having a carboxyl group or a hydroxyl group include (meth) acrylic acid; hydroxyalkyl (meth) acrylates such as hydroxymethyl (meth) acrylate and hydroxyethyl (meth) acrylate. Among these, a monomer having a carboxyl group is preferable from the viewpoint of obtaining excellent slidability and liquid leakage resistance. More preferred is (meth) acrylic acid, and still more preferred is acrylic acid.

Examples of the monomer having an amino group or an amide group include dimethyl (meth) acrylamide, diethyl (meth) acrylamide, isopropyl (meth) acrylamide, hydroxyethyl (meth) acrylamide, methoxymethyl (meth) acrylamide, (meth) acrylamide, and the like. Is mentioned. Among these, a monomer having an amide group is preferable from the viewpoint of obtaining excellent slidability and liquid leakage resistance. More preferred is (meth) acrylamide, and still more preferred is acrylamide.

As a method for radical polymerization of two or more types of monomers in Step 2, two or more types of monomers or a solution thereof are applied to the surface of a modification target on which a benzophenone compound, a thioxanthone compound or the like is adsorbed or covalently bonded ( Spraying) or immersing the modification object in two or more monomers or a solution thereof and irradiating with light such as ultraviolet rays, radical polymerization (photo radical polymerization) proceeds, and the surface of the modification object In contrast, copolymerized polymer chains can be grown. Further, after the coating, the surface is covered with transparent glass, PET, polycarbonate or the like, and each radical polymerization (photo radical polymerization) is advanced by irradiating light such as ultraviolet rays on the surface, and on the surface of the object to be modified. On the other hand, copolymerized polymer chains can also be grown.

Further, the amount of the radical polymerizable monomer used may be appropriately set depending on the length of the polymer chain to be formed, the performance exhibited by the chain, and the like.

Conventionally known materials and methods can be applied to the coating (spraying) solvent, the coating (spraying) method, the dipping method, the irradiation conditions, and the like. In addition, as a solution of a radically polymerizable monomer, the solution which melt | dissolved in the organic solvent which does not melt | dissolve aqueous solution or the photoinitiator (benzophenone type compound, thioxanthone type compound, etc.) to be used is used. Moreover, what contains well-known polymerization inhibitors, such as 4-methylphenol, can also be used as a radically polymerizable monomer (liquid) and its solution.

In the present invention, radical polymerization of two or more monomers proceeds by light irradiation after application of the monomer (liquid) or its solution or immersion in the monomer or its solution. A UV irradiation light source such as a high-pressure mercury lamp, a metal halide lamp, or an LED lamp can be suitably used. The amount of irradiation light may be appropriately set in consideration of the polymerization time and the uniformity of the progress of the reaction. In order to prevent polymerization inhibition due to active gas such as oxygen in the reaction vessel, it is preferable to remove oxygen in the reaction vessel or in the reaction solution at the time of light irradiation or before light irradiation. Therefore, introducing an inert gas such as nitrogen gas or argon gas into the reaction vessel or in the reaction liquid and discharging the active gas such as oxygen out of the reaction system, and replacing the inside of the reaction system with an inert gas atmosphere, The inside of the reaction vessel is evacuated and oxygen is degassed as appropriate. Furthermore, in order to prevent reaction inhibition such as oxygen, a UV irradiation light source is installed at a position where an air layer (oxygen content of 15% or more) does not enter between a reaction vessel such as glass or plastic and a reaction solution or a modification target. A device such as the above is also appropriately performed.

When irradiating with ultraviolet rays, the wavelength is preferably 300 to 450 nm, more preferably 300 to 400 nm. Thereby, a copolymerized polymer chain can be favorably formed on the surface of the modification target. As the light source, a high-pressure mercury lamp, an LED having a central wavelength of 365 nm, an LED having a central wavelength of 375 nm, or the like can be used. Especially, it is preferable to irradiate 300-400 nm LED light, and it is more preferable to irradiate 355-380 nm LED light. In particular, an LED having a center wavelength of 365 nm close to the excitation wavelength of benzophenone of 366 nm is preferable from the viewpoint of efficiency.

After step 2, before performing step 3 described later, if necessary, the modification target on which the copolymer polymer chain has been grown may be subjected to a washing treatment. Thereby, at the same time it becomes a lower elution property, the liquid leakage resistance is further improved.

As the washing treatment, a conventionally known method such as immersion water washing can be adopted, but steam washing is preferable. For example, washing treatment under pressure and heating conditions such as autoclave treatment can be suitably adopted.

As for the conditions for the cleaning treatment, the pressure is preferably 0.1 to 0.5 MPa, and more preferably 0.15 to 0.4 MPa. The temperature is preferably 110 to 150 ° C, more preferably 120 to 140 ° C. The time is preferably 20 to 1000 minutes, more preferably 30 to 500 minutes. When the washing treatment is performed under the above conditions, good liquid leakage resistance can be obtained.

In step 3, a polymerization initiation point B is formed on the surface of the copolymer polymer chain.
The formation of the polymerization initiation point B is the same as in Step 1 such as newly adsorbing the photopolymerization initiator B to the surface of the obtained copolymer polymer chain, and further chemically bonding as necessary. This can be done by applying the method. Here, the photopolymerization initiator B can be the same as the photopolymerization initiator A.

In step 4, starting from the polymerization start point B, a monomer having a smaller charge bias than that of the two or more types of monomers is radically polymerized to grow a polymer chain having a smaller charge bias. By extending the copolymer chain with a polymer chain with less charge bias, excellent liquid leakage resistance and slidability can be obtained.

In step 4, a monomer with less charge bias (a monomer with less electron bias) than the two or more types of monomers is used. Here, in the present invention, a monomer having a small charge bias refers to a monomer having a charge of all atoms of −0.2 to 0.2 determined by molecular orbital calculation. Among these, from the viewpoint of liquid leakage resistance and slidability, the charge of all atoms is preferably −0.15 to 0.15, more preferably −0.1 to 0.1.

Specific examples of the monomer having a small charge bias include (meth) acrylonitrile. Among these, acrylonitrile is preferable from the viewpoint of liquid leakage resistance and sliding properties.

In the present invention, as the two or more types of monomers, a plurality of types of monomers in which at least one charge of each atom obtained by molecular orbital calculation is less than −0.2 or more than 0.2 can be used. From the viewpoint of the effect, a monomer having at least one charge of less than −0.3 or more than 0.3 is preferable, and a monomer of less than −0.35 or more than 0.35 is more preferable.

From the viewpoint of the effect of the present invention, the maximum absolute value δ1 of the charge of each atom of each of the two or more types of monomers and the maximum absolute value δ2 of the charge of each atom of the monomer with a small charge bias are expressed by the following formulas: It is preferable to satisfy.
δ1-δ2> 0.20
More preferably, δ1-δ2> 0.25. On the other hand, the upper limit of δ1-δ2 is not particularly limited, but preferably δ1-δ2 <0.50, more preferably δ1-δ2 <0.40.

In the present invention, as a specific charge calculation method, MOPAC6 is used to calculate the structure optimization of each monomer using the following keywords.
Keywords: MMOK EF PRECISE GNORM = 0.05 NOINTER GRAPH

As a method for radical polymerization of the monomer having a small charge bias, for example, the same method as the method for radical polymerization of two or more types of monomers in Step 2 can be applied.

In addition, even after performing step 4, if necessary, a washing treatment may be performed on the modification target object in which the copolymer polymer chain and the polymer chain with less charge bias are grown. For the treatment, the same method as described above can be adopted.

Moreover, you may irradiate an electron beam after the process 4 to the copolymer chain chain which grew, and a polymer chain with few bias | inclinations of an electric charge. As a result, cross-linking occurs between the polymer chains, and a surface-modified elastic body having better sliding properties and liquid leakage resistance than before cross-linking can be obtained, and at the same time, the surface-modified elastic body can be sterilized. Although the details of the crosslinked structure formed here are not clear, it is presumed that radicals are formed in the polymer chain by electron beam irradiation, and a crosslinked structure is formed between the chains.
In the case where the cleaning treatment is performed, the order is not particularly limited, but the electron beam irradiation is preferably performed after the cleaning.

The acceleration voltage of the irradiated electron beam is preferably 10 to 1000 kV, more preferably 50 to 500 kV, and still more preferably 100 to 200 kV.
The dose of the irradiated electron beam is preferably 1 kGy or more. The dose is preferably 500 kGy or less, more preferably 250 kGy or less, still more preferably 100 kGy or less, and particularly preferably 30 kGy or less. If it exceeds 500 kGy, there is a risk of adverse effects such as molecular cleavage in the polymer chain and the modification target.
In addition, as an electron beam source, a well-known electron beam irradiation apparatus can be used.

The present invention is also a surface modification method using a vulcanized rubber or a thermoplastic elastomer as a modification target, wherein two or more types of monomers are added to the surface of the modification target in the presence of a photopolymerization initiator A. A step I of radical polymerization to grow a copolymer polymer chain, and radical polymerization of a monomer having a smaller charge bias than the two or more types of monomers in the presence of a photopolymerization initiator B on the surface of the copolymer polymer chain; And a step II of growing a polymer chain with less charge bias. Specifically, a photopolymerization initiator A is used as an initiator to radically polymerize two or more types of monomers to prepare a copolymerized polymer chain, and then the photopolymerization initiator B is used as an initiator to reduce the charge bias. The surface-modified elastic body in which a polymer layer with little charge bias is formed on the outermost surface can be produced by extending the polymer chain to produce a polymer chain with little charge bias. In particular, as a monomer having a small charge bias, a monomer having a small charge bias compared to the two or more types of monomers is used, so that excellent slidability and liquid leakage resistance can be obtained.

Step I is a radical polymerization of two or more monomers starting from a polymerization initiation point A formed from the photopolymerization initiator A on the surface of the modification target to grow a copolymerized polymer chain. It is preferable to grow a polymer chain having a small charge bias by radical polymerization of the monomer having a small charge bias starting from the polymerization start point B formed from the photopolymerization initiator B on the surface of the copolymerized polymer chain. For example, in the step I, after the photopolymerization initiator A and two or more types of monomers are brought into contact with the surface of the modification target, polymerization is performed from the photopolymerization initiator A by irradiating LED light of 300 to 450 nm. A starting point A is generated, and two or more types of monomers are radically polymerized starting from the polymerization starting point A to grow a copolymer polymer chain. Step II includes a photopolymerization initiator B and a monomer with less charge bias. Then, by irradiating 300 to 450 nm of LED light, the polymerization initiation point B is generated from the photopolymerization initiator B, and the monomer having a small bias of charge from the polymerization initiation point B is used as a starting point. It can be carried out by growing polymer chains with little charge bias by radical polymerization.

As a method for radical polymerization of each of the two or more types of monomers in step I and the monomer having a small charge bias in step II, the surface of the modification target or the modification target formed with the copolymerized polymer chain, Applying (spraying) two or more types of monomers containing photopolymerization initiators A or B such as benzophenone compounds and thioxanthone compounds, or monomers (liquids) with little charge bias, or solutions thereof, or modification targets Or an object to be modified in which a polymer chain is formed is immersed in two or more types of monomers containing photoinitiator A or B, a monomer (liquid) with little bias in charge or a solution thereof, Each radical polymerization (photo radical polymerization) proceeds by irradiating light, and the surface of the modification target is a copolymerized polymer chain, a polymer with less charge bias. Can be grown over the chain in this order. Furthermore, a method of covering with the above-mentioned transparent glass, PET, polycarbonate, etc. and irradiating light such as ultraviolet rays from the top can be adopted. As described above, a reducing agent and an antioxidant substance may be added. The same materials and methods as described above can be applied to the coating (spraying) solvent, the coating (spraying) method, the dipping method, and the irradiation conditions.

In addition, after process I and II, you may wash | clean the modification target object which grew the copolymer polymer chain and the polymer chain with few bias | inclinations of an electric charge as needed. Moreover, you may irradiate an electron beam to the polymer chain which grew after process II and the polymer chain with few bias | inclinations of an electric charge. For the cleaning treatment and electron beam irradiation, the same methods as described above can be adopted.

By forming a polymer chain that includes a polymer chain with less charge bias, excellent slidability and liquid leakage resistance can be obtained. The degree of polymerization of the formed polymer chain is preferably 20 to 200000, more preferably 350 to 50000.

The length of the total polymer chain including the copolymer polymer chain and the polymer chain with little charge bias is preferably 10 to 50000 nm, more preferably 100 to 50000 nm. If it is less than 10 nm, there is a tendency that good slidability cannot be obtained. If it exceeds 50000 nm, further improvement in slidability cannot be expected, and the liquid leakage resistance tends to decrease.

In all polymer chains, the ratio of the length of the copolymer polymer chain to the length of the polymer chain with less charge bias (the length of the copolymer polymer chain: the length of the polymer chain with less charge bias) is preferably 50:50 to 99.9: 0.1, more preferably 90:10 to 99.5: 0.5.

In Step 4 and Step II, two or more types of monomers with little bias in charge may be radically polymerized starting from the polymerization start point B. Further, the copolymer polymer chain and the polymer chain with little charge bias may be laminated in two or more layers. Furthermore, a plurality of polymer chains may be grown on the surface of the modification target. The surface modification method of the present invention may crosslink between polymer chains. In this case, ionic crosslinking, crosslinking with a hydrophilic group having an oxygen atom, and crosslinking with a halogen group such as iodine may be formed between the polymer chains.

By applying the surface modification method to vulcanized rubber or thermoplastic elastomer, a surface modified elastic body can be obtained. For example, a surface-modified elastic body excellent in slidability in the presence of water or in a dry state is obtained, which is excellent in that it has low friction and low water resistance. Further, by applying the method to at least a part of a three-dimensional solid (such as an elastic body), a modified surface-modified elastic body can be obtained. Furthermore, a polymer brush (polymer brush) is mentioned as a preferable example of the surface modified elastic body. Here, the polymer brush means a grafting graft polymer by surface-initiated living radical polymerization. In addition, the graft chain is preferably oriented in the substantially vertical direction from the surface of the modification target because the entropy is reduced and the molecular motion of the graft chain is lowered, so that the slidability is obtained. Furthermore, as the brush density, a quasi-density and a density brush that are 0.01 chains / nm ² or more are preferable.

Further, by applying the surface modification method to vulcanized rubber or thermoplastic elastomer, a medical device such as a syringe gasket or a syringe for syringe having at least a part of the modified surface can be produced. The modification is preferably performed at least on the sliding portion of the gasket or syringe surface, and may be performed on the entire surface.

FIG. 1 is an example of a side view of an embodiment of a syringe gasket. The gasket 1 shown in FIG. 1 has three annular protrusions 11a, 11b, and 11c that continuously protrude in the circumferential direction on the outer peripheral surface that contacts the inner peripheral surface of the syringe barrel of the syringe. In the gasket 1, the surface modification is applied to (1) the surface of the protruding portion in contact with the syringe such as the annular protruding portions 11 a, 11 b, 11 c, and (2) the side surface including the annular protruding portions 11 a, 11 b, 11 c. The entire surface includes (3) the entire surface of the side surface and the surface 13 of the bottom surface portion.

Furthermore, by applying the surface modification method to a groove formed in a tread of a tire used in a vehicle such as a passenger car and generating a polymer brush in the groove, the fluid resistance of the groove surface on a wet or snowy road surface is reduced. Or the contact angle with water is increased, water and snow can be eliminated and brushed, and the grip can be improved.

FIG. 2 shows an example of a development view of the tread portion 2 of the pneumatic tire (not shown), and FIG. 3 shows an example of the A1-A1 cross-sectional view of FIG.
2 to 3, the central vertical groove 3 a (groove depth D <b> 1) and the shoulder vertical groove 3 b (groove depth D <b> 2) are constituted by straight grooves extending linearly in the tire circumferential direction. Such straight grooves can reduce drainage resistance and exhibit high drainage performance when traveling straight ahead.

The pneumatic tire has a narrow groove 5 (groove depth D3) extending in the tire circumferential direction on the shoulder longitudinal groove 3b side, and an intermediate inclined groove 6 (groove) extending from the narrow groove 5 toward the central longitudinal groove 3a. Depth D4), joint groove 7 (groove depth D5) that is located on the inner side in the tire axial direction than the narrow groove 5 and that connects between the intermediate inclined grooves 6 and 6 adjacent in the tire circumferential direction, and from the shoulder vertical groove 3b to the tire Shoulder lateral grooves 8, 8 a, 8 b (groove depth D 6) and the like that extend to the outside are arranged, and drainage performance can be exhibited even with such grooves. And the above-mentioned effect is exhibited by applying the method to these grooves. Moreover, the effect which suppresses adhesion of dust and dust by applying the said method to the sidewall surface is also expected.

EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited only to these.

Example 1
A vulcanized rubber gasket (vulcanized at 180 ° C. for 10 minutes) obtained by crosslinking chlorobutyl rubber containing an isoprene unit (unsaturation: 1 to 2%) with triazine is immersed in a 1 wt% acetone solution of benzophenone to vulcanize rubber surface Was adsorbed with benzophenone and dried.
The dried vulcanized rubber gasket was immersed in a glass reaction vessel containing a mixed aqueous solution of acrylic acid / acrylamide (2.5 M: 1.8 g of acrylic acid and 16.0 g of acrylamide dissolved in 100 mL of water) at 365 nm. LED-UV light having a wavelength of 80 nm was irradiated for 80 minutes for radical polymerization to grow copolymerized polymer chains on the vulcanized rubber surface. Thereafter, the surface was washed with water and dried.
Next, the dried vulcanized rubber gasket was again immersed in a 1 wt% acetone solution of benzophenone to adsorb benzophenone on the surface of the copolymerized polymer chain, and dried.
Further, the dried vulcanized rubber gasket was immersed in a glass reaction vessel containing an aqueous solution of acrylonitrile (0.57M: 2.95 g of acrylonitrile dissolved in 100 ml of water), and an LED-UV light having a wavelength of 365 nm was obtained. Radiation polymerization was performed by irradiating for 30 minutes to grow a polymer chain with little charge bias on the surface of the copolymer polymer chain. As a result, a surface-modified elastic body (laminated polymer brush) was obtained.

(Example 2)
After the copolymer polymer chain is grown on the surface of the vulcanized rubber and the surface is washed with water, the vulcanized rubber gasket is further immersed in water 10 times the volume of the gasket and steam washed at 135 ° C. and 0.32 MPa for 1 hour ( A surface-modified elastic body (laminated polymer brush) was obtained in the same manner as in Example 1 except that autoclave washing was performed.

(Example 3)
A surface-modified elastic body (laminated polymer brush) was prepared in the same manner as in Example 1 except that the polymerization time (LED-UV light irradiation time) of the two monomers (acrylic acid / acrylamide) was changed to 100 minutes. Obtained.

Example 4
A surface-modified elastic body (laminated polymer brush) was prepared in the same manner as in Example 2 except that the polymerization time (LED-UV light irradiation time) of two types of monomers (acrylic acid / acrylamide) was changed to 100 minutes. Obtained.

(Example 5)
Surface-modified elastic body (laminated polymer brush) in the same manner as in Example 3 except that the polymerization time (LED-UV light irradiation time) of the monomer (acrylonitrile) with less charge bias was changed to 22.5 minutes. Got.

(Example 6)
Surface-modified elastic body (laminated polymer brush) in the same manner as in Example 4 except that the polymerization time (LED-UV light irradiation time) of the monomer (acrylonitrile) with little charge bias was changed to 22.5 minutes. Got.

(Example 7)
A vulcanized rubber gasket (vulcanized for 10 minutes at 180 ° C.) obtained by crosslinking chlorobutyl rubber containing an isoprene unit (unsaturation: 1 to 2%) with triazine was mixed with an aqueous solution of acrylic acid / acrylamide (2.5 M: 1. 8 g of acrylic acid and 16.0 g of acrylamide dissolved in 100 mL of water), immersed in a glass reaction container containing 3 mg of benzophenone and irradiated with LED-UV light having a wavelength of 365 nm for 80 minutes. Radical polymerization was performed to grow copolymerized polymer chains on the rubber surface. Thereafter, the surface was washed with water and dried.
Next, the dried gasket was immersed in a glass reaction vessel containing an aqueous solution of acrylonitrile (0.57 M: 2.95 g of acrylonitrile dissolved in 100 mL of water) and 3 mg of benzophenone, and a wavelength of 365 nm was immersed. Radiation polymerization was performed by irradiating the LED-UV light possessed for 30 minutes to grow a polymer chain with little charge bias on the surface of the copolymer polymer chain. As a result, a surface-modified elastic body (laminated polymer brush) was obtained.

(Comparative Example 1)
A vulcanized rubber (vulcanized at 180 ° C. for 10 minutes) itself obtained by crosslinking chlorobutyl rubber containing an isoprene unit (unsaturation degree: 1 to 2%) with triazine was used.

(Comparative Example 2)
A vulcanized rubber gasket (vulcanized at 180 ° C. for 10 minutes) obtained by crosslinking chlorobutyl rubber containing an isoprene unit (unsaturation: 1 to 2%) with triazine is immersed in a 1 wt% acetone solution of benzophenone to vulcanize rubber surface Was adsorbed with benzophenone and dried.
The dried vulcanized rubber gasket is immersed in a glass reaction vessel containing an aqueous solution of acrylic acid (2.5 M: 18.0 g of acrylic acid dissolved in 100 mL of water), and an LED-UV light having a wavelength of 365 nm is obtained. Radiation polymerization was performed by irradiation for 30 minutes to grow polymer chains on the surface of the vulcanized rubber. As a result, a surface-modified elastic body (laminated polymer brush) was obtained.

(Comparative Example 3)
A vulcanized rubber gasket (vulcanized at 180 ° C. for 10 minutes) obtained by crosslinking chlorobutyl rubber containing an isoprene unit (unsaturation: 1 to 2%) with triazine is immersed in a 1 wt% acetone solution of benzophenone to vulcanize rubber surface Was adsorbed with benzophenone and dried.
The dried vulcanized rubber gasket was immersed in a glass reaction vessel containing a mixed aqueous solution of acrylic acid / acrylamide (2.5 M: 1.8 g of acrylic acid and 16.0 g of acrylamide dissolved in 100 mL of water) at 365 nm. LED-UV light having a wavelength of 80 nm was irradiated for 80 minutes for radical polymerization to grow copolymerized polymer chains on the vulcanized rubber surface. As a result, a surface-modified elastic body (laminated polymer brush) was obtained.

In addition, the charge of each atom of acrylic acid, acrylamide, and acrylonitrile calculated | required by the said molecular orbital calculation is shown to the following Tables 1-3.

The surface-modified elastic bodies produced in Examples and Comparative Examples were evaluated by the following methods.
(Polymer chain length)
The length of the polymer chain formed on the surface of the vulcanized rubber was measured using an SEM at an acceleration voltage of 15 kV and 1000 times the cross section of the modified rubber on which the polymer chain was formed. The film thickness of the polymer layer was taken as the length of the polymer chain.

(Friction resistance)
In order to measure the frictional resistance force on the surface of the surface-modified elastic body, the vulcanized rubber gaskets prepared in Examples and Comparative Examples were set in a COP resin syringe of a syringe and pushed in using a tensile tester. Friction resistance was measured (pushing speed: 30 mm / min). The friction resistance of Comparative Example 1 was set to 100, and the following formula was used, and each example was shown as a friction resistance index. A smaller index indicates a lower frictional resistance.
(Friction resistance index) = Friction resistance of each Example / Friction resistance of Comparative Example 1 × 100

(Liquid leakage resistance)
The vulcanized rubber gaskets produced in Examples and Comparative Examples were immersed in a red food solution for one day, pulled up and washed with water, and the state of adsorption to the surface of the red food was visually evaluated (red dyeing condition). The red color of the red food means that the ionic drug is slightly adsorbed, and the non-red color indicates better liquid leakage resistance.

From Table 4, by forming a copolymer chain with two types of monomers and a polymer chain with less charge bias due to less charge bias, liquid leakage resistance can be improved and good slidability can be obtained. It was. It was also revealed that slidability and liquid leakage resistance were further improved by steam cleaning.

Therefore, when used as a gasket for a plunger of a syringe, the frictional force of the plunger against the syringe is reduced together with sufficient liquid leakage resistance, so that the treatment by the syringe can be performed easily and accurately. Further, since the difference between the static friction coefficient and the dynamic friction coefficient is small, the start of pushing the plunger and the subsequent plunger approaching operation can be performed smoothly without pulsating. Further, when a syringe syringe is made of a thermoplastic elastomer and a polymer chain is formed on the inner surface thereof, prescription by a syringe can be easily performed as described above.

In addition, by forming polymer chains on the surface of grooves, sidewalls, diaphragms, skis and snowboard boards, swimming swimsuits, road signs, signboards, etc. formed on the tread of tires used in passenger cars etc. Can also be expected.

DESCRIPTION OF SYMBOLS 1 Gasket 11a, 11b, 11c Annular projection part 13 Surface 2 of a bottom part 2 Tread part 3a Center vertical groove 3b Shoulder vertical groove 5 Narrow groove 6 Intermediate inclination groove 7 Joint groove 8, 8a, 8b Shoulder horizontal groove

Claims (26)

A surface modification method using a vulcanized rubber or a thermoplastic elastomer as a modification object,
Forming a polymerization initiation point A on the surface of the modification target; and
Step 2 of radically polymerizing two or more types of monomers starting from the polymerization starting point A to grow a copolymerized polymer chain;
Forming a polymerization initiation point B on the surface of the copolymer chain; and
Look including the step 4 growing the polymerization initiation point deviation less polymer chain B the less monomer biased charge from a monomer of the two or more as a starting point by radical polymerization charge,
A surface modification method in which the monomer having a small charge bias is (meth) acrylonitrile . In the step 2, the two or more monomers are radically polymerized by irradiation with LED light of 300 to 450 nm starting from the polymerization starting point A, and the copolymer polymer chain is grown.
In the step 4, starting from the polymerization start point B, the monomer having a small charge bias is radically polymerized by irradiation with LED light of 300 to 450 nm to grow the polymer chain having a small charge bias. Item 2. The surface modification method according to Item 1. In the step 1, a photopolymerization initiator A is adsorbed on the surface of the object to be modified, or LED light of 300 to 450 nm is further irradiated to form a polymerization start point A from the photopolymerization initiator A on the surface. It is what
In the step 3, the photopolymerization initiator B is adsorbed on the surface of the copolymerized polymer chain or further irradiated with 300 to 450 nm LED light to form a polymerization start point B from the photopolymerization initiator B on the surface. The surface modification method according to claim 1 or 2, wherein A surface modification method using a vulcanized rubber or a thermoplastic elastomer as a modification object,
A step I of radically polymerizing two or more monomers in the presence of a photopolymerization initiator A on the surface of the modification target to grow a copolymerized polymer chain; and
A step II of radically polymerizing a monomer having less charge bias than the two or more monomers in the presence of a photopolymerization initiator B on the surface of the copolymer polymer chain to grow a polymer chain having less charge bias. See
A surface modification method in which the monomer having a small charge bias is (meth) acrylonitrile . In the step I, the two or more types of monomers are radically polymerized by irradiation with LED light of 300 to 450 nm to grow the copolymer polymer chain,
5. The surface modification method according to claim 4, wherein in the step II, the monomer having less charge bias is radically polymerized by irradiation with LED light of 300 to 450 nm to grow the polymer chain having less charge bias. 6. The surface modification method according to claim 3, wherein the photopolymerization initiators A and B are the same or different and are a benzophenone compound and / or a thioxanthone compound. The surface modification method according to any one of claims 1 to 6, wherein a step of washing the object to be modified is performed after at least one of the step 2, the step 4, the step I, and the step II. The surface modification method according to claim 7, wherein the cleaning is steam cleaning performed at 110 to 150 ° C. The surface modification method according to any one of claims 1 to 8, wherein the vulcanized rubber or the thermoplastic elastomer has an allylic carbon atom that is a carbon atom adjacent to a double bond. The surface modification method according to claim 1, wherein the polymerization is performed in an inert gas atmosphere. The surface modification method according to claim 1, wherein polymerization is performed under vacuum degassing conditions. The surface modification method according to claim 1, wherein the two or more types of monomers include a monomer having a carboxyl group or a hydroxyl group and a monomer having an amino group or an amide group. The monomer having a carboxyl group or a hydroxyl group is at least one selected from the group consisting of (meth) acrylic acid and hydroxyalkyl (meth) acrylate,
The monomer having an amino group or an amide group is composed of dimethyl (meth) acrylamide, diethyl (meth) acrylamide, isopropyl (meth) acrylamide, hydroxyethyl (meth) acrylamide, methoxymethyl (meth) acrylamide, and (meth) acrylamide. The surface modification method according to claim 12 , which is at least one selected from the group. The maximum value δ1 of the absolute value of the charge of each atom of each of the two or more types of monomers and the maximum value δ2 of the absolute value of the charge of each atom of the monomer with a small charge bias satisfy the following formulas : The surface modification method according to any one of the above.
δ1-δ2> 0.20 The said 2 or more types of monomer, the monomer (liquid) with little bias | inclination of an electric charge, or those solutions contain a polymerization inhibitor, It superposes | polymerizes in presence of this polymerization inhibitor. The surface modification method as described. The surface modification method according to any one of claims 1 to 15, wherein, after the step 4 or the step II, an electron beam is irradiated to the grown copolymer polymer chain and the polymer chain with little bias of charge. The surface modification method according to any one of claims 1 to 16, wherein a length of all the polymer chains including the copolymer polymer chain and the polymer chain with a small charge bias is 10 to 50000 nm. 18. The surface modification method according to claim 1, wherein the ratio of the length of the copolymer polymer chain to the length of the polymer chain with less charge bias is 50:50 to 99.9: 0.1. A surface-modified elastic body obtained by the surface modification method according to claim 1. A surface-modified elastic body that is required to have slidability, low friction, or low water resistance in the presence of water or in a dry state obtained by the surface modification method according to claim 1. A surface-modified elastic body in which at least a part of a three-dimensional solid surface is modified by the surface modification method according to claim 1. The surface-modified elastic body according to any one of claims 19 to 21, which is a polymer brush. A medical device having at least a part of the surface modified by the surface modification method according to claim 1. A syringe gasket having at least a part of the surface modified by the surface modification method according to claim 1. A syringe for a syringe having at least a part of the surface modified by the surface modification method according to claim 1. A tire having at least a part of a groove surface and / or a sidewall surface of the tire modified by the surface modification method according to claim 1.

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