Surface-modifying method and elastic body with modified surface

Patent metadata

Field	Value
Publication number	US-9469736-B2
Application number	US-201214118136-A
Country	US
Kind code	B2
Filing date	May 31, 2012
Priority date	Jun 3, 2011
Publication date	Oct 18, 2016
Grant date	Oct 18, 2016

Abstract

The present invention aims to provide a method for modifying a surface of a rubber vulcanizate or a thermoplastic elastomer, which can impart excellent sliding properties and excellent durability against repeated sliding motion, and allow the surface to maintain the sealing properties, without using expensive self-lubricating resins. The present invention relates to a method for modifying a surface of an object of a rubber vulcanizate or a thermoplastic elastomer, the method including: Step 1 of forming polymerization initiation points on the surface of the object; and Step 2 of radical-polymerizing a monomer starting from the polymerization initiation points to grow polymer chains on the surface of the object.

First claim

The invention claimed is:

1. A gasket for syringes, at least partially having a surface modified by a method for modifying a surface of an object of a rubber vulcanizate or a thermoplastic elastomer,
the method comprising:
Step 1 of forming polymerization initiation points on the surface of the object; and
Step 2 of radical-polymerizing a monomer starting from the polymerization initiation points to grow polymer chains on the surface of the object,
wherein the rubber vulcanizate or thermoplastic elastomer contains an allylic carbon atom which is a carbon atom adjacent to a double bond.

2. A tire, at least partially having a groove surface modified by a method for modifying a surface of an object of a rubber vulcanizate or a thermoplastic elastomer,
the method comprising:
Step 1 of forming polymerization initiation points on the surface of the object; and
Step 2 of radical-polymerizing a monomer starting from the polymerization initiation points to grow polymer chains on the surface of the object.

3. The gasket for syringes according to claim 1 , wherein the polymerization initiation points are formed through adsorption of a photoinitiator onto the surface of the object.

4. The gasket for syringes according to claim 3 , wherein the photoinitiator is a benzophenone compound.

5. The gasket for syringes according to claim 3 , wherein the adsorbed photoinitiator is irradiated with light so that the photoinitiator chemically bonds to the surface of the object.

6. The gasket for syringes according to claim 1 , wherein the radical polymerization is photo-radical polymerization.

7. The gasket for syringes according to claim 5 , wherein the light is ultraviolet light having a wavelength of 300 to 450 nm.

8. The gasket for syringes according to claim 5 , wherein an inert gas is inserted into a reaction container and a reaction solution during or before the light irradiation, to create an atmosphere replaced with the inert gas.

9. The gasket for syringes according to claim 1 , wherein the monomer is at least one selected from the group consisting of ionic monomers and zwitterionic monomers.

10. The gasket for syringes according to claim 1 , wherein the monomer is at least one selected from the group consisting of acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, isobutyl acrylate, tert-butyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, 3-sulfopropyl methacrylate potassium salt, 2-(methacryloyloxy)ethyltrimethylammonium chloride, and 2-methacryloyloxyethyl phosphorylcholine.

11. The gasket for syringes according to claim 1 , wherein the monomer is at least one compound represented by the following formula:

wherein R A represents a hydrogen atom, a methyl group, an ethyl group, or a propyl group;
R B represents a C1 to C10 alkylene group; and R C represents a hydrogen atom or a C1 to C10 alkyl group.

12. The gasket for syringes according to claim 1 , wherein the polymer chains are represented by any of the following formulae (1) to (3):

wherein n is an integer of 1 or greater,

wherein n is an integer of 1 or greater; and 5≦a/b≦200, and

wherein n is an integer of 1 or greater; p≧2; q=2, 3, or 4;
and R is a hydrocarbon group.

13. The gasket for syringe according to claim 1 , wherein the monomer is a fluoroalkyl group-containing monomer.

14. The gasket for syringes according to claim 12 , wherein the fluoroalkyl group-containing monomer is at least one selected from the group consisting of 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,12-heneicosafluorododecyl acrylate (H 2 C═CHCO 2 CH 2 CH 2 (CF 2 ) 9 CF 3 ), 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl acrylate (H 2 C═CHCO 2 CH 2 CH 2 (CF 2 ) 7 CF 3 ), 3-(perfluorobutyl)-2-hydroxypropyl acrylate (F(CF 2 ) 4 CH 2 CH(OH)CH 2 OCOCH═CH 2 ), 3-perfluorohexyl-2-hydroxypropyl acrylate (F(CF 2 ) 6 CH 2 CH(OH)CH 2 OCOCH═CH 2 ), 3-(perfluoro-3-methylbutyl)-2-hydroxypropyl acrylate ((CF 3 ) 2 CF(CF 2 ) 2 CH 2 CH(OH)CH 2 OCOCH═CH 2 ), and 3-(perfluoro-5-methylhexyl)-2-hydroxypropyl acrylate ((CF 3 ) 2 CF(CF 2 ) 4 CH 2 CH(OH)CH 2 OCOCH═CH 2 ).

15. The gasket for syringes according to claim 12 , wherein the fluoroalkyl group-containing monomer is a compound represented by the following formula (8), (9), (10), or (11):

wherein R 31 represents hydrogen, a methyl group, an ethyl group, or a propyl group; R 32 represents —O— or —NH—; R 41 represents a methylene group, an ethylene group, or a propylene group; R 51 represents a ketone group, and may or may not be present; w1 represents an integer of 1 to 100; and z represents an integer of 1 to 6,

wherein R 31 represents hydrogen, a methyl group, an ethyl group, or a propyl group; w2 represents an integer of 4 to 10; and z represents an integer of 1 to 6,

wherein R 31 represents hydrogen, a methyl group, an ethyl group, or a propyl group; w3 and w4 each independently represent an integer of 1 to 6; and z represents an integer of 1 to 6, and

wherein R 31 represents hydrogen, a methyl group, an ethyl group, or a propyl group; w3 and w4 each independently represent an integer of 1 to 6; z represents an integer of 1 to 6; and α represents an integer of 1 or 2.

16. The gasket for syringes according to claim 6 , wherein the photo-radical polymerization comprises bringing a liquid radical polymerizable monomer or a solution thereof into contact with the surface of the object or the surface of the object to which the photoinitiator is adsorbed or covalently bonded; and irradiating the surface with light to allow polymerization to proceed.

17. The gasket for syringes according to claim 15 , wherein the liquid radical polymerizable monomer or the solution thereof contains a polymerization inhibitor, and the monomer is polymerized in the presence of the polymerization inhibitor.

18. The gasket for syringes according to claim 16 , wherein the polymerization inhibitor is 4-methylphenol.

19. The gasket for syringes according to claim 1 , wherein the polymer chains each have a length of 10 to 50000 nm.

Assignees

• Minagawa Yasuhisa
• Sumitomo Rubber Ind

Inventors

• Minagawa Yasuhisa

Classifications

• C08F291/02

  on to elastomers · CPC title

• B60C1/0016

  Compositions of the tread · CPC title

• B60C11/1346

  covered by a rubber different from the tread rubber · CPC title

• F16J15/56

  Other sealings for reciprocating rods · CPC title

• F16J15/3284

  characterised by their structure; Selection of materials · CPC title