Hydrophilic polymer treatment of an activated polymeric material and use thereof

• US 6,830,782 B2
• Filed: 08/27/2001
• Issued: 12/14/2004
• Est. Priority Date: 12/28/1999
• Status: Expired due to Term

• Current Assignee: KB International LLC
• Original Assignee: KB International LLC
• Inventors: Kanazawa, Hitoshi
• Primary Examiner(s): BERMAN, SUSAN W
• Application Number:
  US09/914,441
• Publication Number:
  US 20030087982A1
• Time in Patent Office: 1,205 Days
• Field of Search: 427/458, 427/2.9, 427/533, 427/535, 427/536, 427/538, 427/551, 427/553, 427/487, 427/488, 427/491, 433/8, 522/111, 522/112, 522/88, 522/79, 522/80, 522/150-166, 522/71, 522/74, 522/81, 525/388, 525/345, 525/57, 525/61, 525/54, 525/54.21, 525/54.23, 525/54.26
• US Class Current: 427/458
• CPC Class Codes: C08J 2323/12 Polypropene
• CPC Class Codes: C08J 2429/04 Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids
• CPC Class Codes: C08J 7/0427 with only one layer of a composition containing a polymer binder with more layers C08J7/042
• CPC Class Codes: C08J 7/043 Improving the adhesiveness of the coatings per se, e.g. forming primers adhesives in the form of films or foils characterised by the primer layers between the polymer carriers and the adhesives C09J7/50
• CPC Class Codes: C08J 7/054 Forming anti-misting or drip-proofing coatings
• CPC Class Codes: C08J 7/056 Forming hydrophilic coatings
• CPC Class Codes: D06M 14/00 Graft polymerisation of monomers containing carbon-to-carbon unsaturated bonds on to fibres, threads, yarns, fabrics, or fibrous goods made from such materials on to unshaped polymers C08F251/00 - C08F292/00
• CPC Class Codes: D06M 14/18 using wave energy or particle radiation
• CPC Class Codes: D06M 2200/00 Functionality of the treatment composition and/or properties imparted to the textile material
• CPC Class Codes: D21H 25/02 Chemical or biochemical treatment D21H25/18 takes precedence
• CPC Class Codes: H01M 10/24 Alkaline accumulators
• CPC Class Codes: H01M 50/417 Polyolefins
• CPC Class Codes: H01M 50/423 Polyamide resins
• CPC Class Codes: H01M 50/429 Natural polymers
• CPC Class Codes: H01M 50/44 Fibrous material
• CPC Class Codes: H01M 50/491 Porosity
• CPC Class Codes: H01M 50/494 Tensile strength
• CPC Class Codes: H01M 6/04 Cells with aqueous electrolyte
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A method of modifying a polymeric material which comprises the steps of activation-treatment and a hydrophilic polymer-treatment, or comprises the steps of activation-treatment, a hydrophilic polymer-treatment, and monomer grafting in this order, or comprises the step of a solvent-treatment followed by these steps. Thus, the polymeric material, e.g., polyolefin, is improved in hydrophilicity, adhesion, etc. without lowering the practical strength thereof. The polymeric material thus improved in adhesion and other properties can be used in many applications where water absorption and adhesion are required, such as an absorption material, e.g., a wiping/cleansing material, a water retention material, a material for microorganism culture media, a separator for batteries (or cells), a synthetic paper, a filter medium, a textile product for clothing, a medical/sanitary/cosmetic supply, and reinforcing fibers for composite materials.

Claims

1. A method of modifying a polymeric material for improving a hydrophilic property, water absorption property or adhesion property which comprises:

(a) subjecting the polymeric material to an activation step for introducing a double bond or a functional group containing at least a carbonyl group on the surface of the polymeric material to the extent that a trace of the formation of the carbonyl group is observed from a ratio of about 0.2 or less of an absorbance at around 1710 cm<sup>−

1</sup> due to carbonyl groups introduced in the surface of polymeric material to an absorbance of the crystalline region not changed by the activation step by employing a base line method of infrared spectroscopy; and

(b) treating the activated polymeric material produced in said activation step with a hydrophilic polymer in the presence of a catalyst or an initiator under conditions effective to produce said modified polymer, wherein the weight increase of the treated polymeric material is less than 5 wt %.

2. The method of modifying a polymeric material according to claim 1 further comprising the step of monomer grafting in the presence or absence of a catalyst or an initiator under conditions effective to produce said modified polymer after step (b).

3. The method according to claim 2, wherein said monomer is a compound having a carbon-carbon double bond.

4. The method according to claim 3, wherein said monomer is at least one of the monomers selected from the group consisting of acrylic acid, methacrylic acid, vinyl acetate, 2-butene acid, ethylene sulfonic acid, hydroxyalkyl acrylate, hydroxyalkyl methacrylate, acryl amide, vinyl pyridine, vinyl pyrrolidone, vinyl carbazole, maleic anhydride and pyromellitic dianhydride.

5. The method according to claim 2, wherein said step of monomer grafting is carried out by any one of or both of the following two methods:

(1) heating in the presence of catalysts or initiators and (2) UV irradiation in the presence or absence of catalysts, initiators or photo-sensitizers.

6. The method according to claim 2, wherein said initiators are at least one of peroxides, cerium ammonium nitrate (IV) or persulfates.

7. The method of modifying a polymeric material according to claim 1, further comprising the step of a solvent-treatment prior to the activation step (a), wherein the polymeric material is dipped in a solvent for about 1 minute to 60 minutes at a temperature of about 60°

C. or less, and a weight increase of the polymeric material is 10% or less of the original weight.

8. The method of modifying a polymeric material according to claim 1, further comprising the step of a solvent-treatment prior to the activation step (a) and a step of monomer grafting after step (b), wherein in the solvent-treatment the polymeric material is dipped in a solvent for about 1 minute to 60 minutes at a temperature to about 60°

C., and a weight increase of the polymeric material is up to 10% of the original weight.

9. The method according to claim 8, wherein said monomer is a compound having a carbon-carbon double bond.

10. The method according to claim 9, wherein said monomer is at least one of the monomers selected from the group consisting of acrylic acid, methacrylic acid, vinyl acetate, 2-butene acid, ethylene sulfonic acid, hydroxyalkyl acrylate, hydroxyalkyl methacrylate, acryl amide, vinyl pyridine, vinyl pyrrolidone, vinyl carbazole, maleic anhydride and pyromellitic dianhydride.

11. The method according to claim 8, wherein said step of monomer grafting is carried out by any one of or both of the following two methods:

(1) heating in the presence of catalysts or initiators and (2) UV irradiation in the presence or absence of catalysts, initiators or photo-sensitizers.

12. The method according to claim 1, wherein said polymeric material is a homopolymer or copolymer of one or more compounds selected from the group consisting of:

olefins, vinyl compounds except olefins, vinylidene compounds, polyesters, polyamides, polyimides, polyurethanes, polybenzoates, poly(benzoxazole)s, poly(benzthiazole)s, poly-(p-phenylene benzbisoxazole)s, poly-(p-phenylene benzbis-thiazole)s, poly(alkyl-p-hydroxybenzoate)s, poly(benzimidazole)s, carbonized polymeric materials, polyphenols, cellulose acetate, regenerated cellulose, vinylon, polychlal, casein, wool, silk, hemp, ramie, and jute.

13. The method according to claim 1, wherein said polymeric material is in the form of any one of fibers, woven fabrics, knitted webs, non-woven fabrics, plates, rods, films, sheets, porous films, members or parts of molded materials in a given shape or composite materials with other materials.

14. The method according to claim 1, wherein said activation-treatment is at least one of the treatments selected from the group consisting of an ozone treatment, a plasma treatment, a UV irradiation treatment and a high voltage electric discharge treatment.

15. The method according to claim 1, wherein said hydrophilic polymer is at least one member selected from the group consisting of polyvinyl alcohol, carboxymethylcellulose, poly(hydroxy-ethyl methacrylate), poly-α

-hydroxy vinylalcohol, polyacrylic acid, polyvinyl pyrrolidone, polyalkylene glycols, starche, silk fibroin, sericin, agar, gelatin, egg white and sodium arginate.

16. The method according to claim 1, wherein said initiators are at least one of peroxides, cerium ammonium nitrate (IV) or persulfates.

17. Writing materials containing modified polymeric materials obtained by the method according to claim 1.

18. Synthetic papers made of modified polymeric materials obtained by the method according to claim 1.

19. Orthodontic brackets containing modified polymeric materials obtained by the method according to claim 1.