Reinforced pavement-marking sheet material

• US 4,490,432 A
• Filed: 11/01/1983
• Issued: 12/25/1984
• Est. Priority Date: 04/23/1982
• Status: Expired due to Term

• Current Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Original Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Inventors: Jordan, Stanley J.
• Primary Examiner(s): HERBERT JR, THOMAS
• Application Number:
  US06/547,663
• Time in Patent Office: 420 Days
• Field of Search: 428/337, 428/323, 428/324, 428/331, 428/220, 404/14, 264/1.6, 264/1.7
• US Class Current: 428/220
• CPC Class Codes: B29C 43/003 characterised by the choice of material
• CPC Class Codes: B29C 43/24 Calendering
• CPC Class Codes: B29K 2021/00 Use of unspecified rubbers as moulding material
• CPC Class Codes: B29K 2105/16 Fillers
• CPC Class Codes: B29K 2223/00 Use of polyalkenes or derivatives thereof as reinforcement
• CPC Class Codes: B29L 2007/008 Wide strips, e.g. films, webs
• CPC Class Codes: E01F 9/512 Preformed road surface markings, e.g. of sheet material; Methods of applying preformed markings
• CPC Class Codes: Y10T 428/25 Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 428/251 Mica
• CPC Class Codes: Y10T 428/259 Silicic material

Abstract

Pavement-marking sheet material which comprises a non-crosslinked elastomeric precursor such as acrylonitrile-butadiene polymer; a thermoplastic polymer such as polyethylene which reinforces the sheet material, e.g., by orientation of the thermoplastic polymer so that the calendered product exhibits greater tensile strength downweb than crossweb; and a particulate inorganic filler, which preferably includes platelet-type fillers such as talc, mica, or magnesium silicate.

Claims

1. Pavement-marking composition in sheet form comprising 100 parts of non-crosslinked elastomer precursor, at least 5 parts of a thermoplastic reinforcing polymer which is dispersed in the elastomer as a separate phase and softens at a temperature between about 75°

and 200°

C., and a particulate inorganic filler dispersed in the composition;

said composition being processable on calendering rolls to a thickness between about 1/4 and 5 millimeters, and in sheet form having a greater tensile strength downweb than it has in the crossweb direction.

2. Pavement-marking composition of claim 1 in which said thermoplastic reinforcing polymer comprises polyolefin.

3. Pavement-marking composition of claim 1 which has a tensile strength of at least 10 kilograms per square centimeter.

4. Pavement-marking composition of claim 1 in which the non-crosslinked elastomer precursor comprises acrylonitrile-butadiene polymer.

5. Pavement-marking composition of claim 1 in which said thermoplastic reinforcing polymer comprises polyethylene.

6. Pavement-marking composition of claim 5 in which the polyethylene is selected from linear low-density polyethylenes and high-density polyethylene having a molecular weight of at least about 20,000 and low-density polyethylene having a molecular weight of at least about 75,000.

7. Pavement-marking composition of claim 1 which further includes a thermoplastic extender resin that is miscible in, and forms a single phase with, the non-crosslinked elastomer precursor.

8. Pavement-marking composition of claim 7 in which said thermoplastic extender resin comprises a halogenated paraffin.

9. Pavement-marking composition of claims 1, 2, 5, 6, 3, 7, 4, or 8 in which the filler comprises platelet fillers.

11. Pavement-marking composition of claims 1 or 10 having an embossed top surface.

10. Pavement-marking composition in sheet form comprising 100 parts of non-crosslinked elastomer precursor;

at least 5 parts of a polyethylene reinforcing polymer which is dispersed in the elastomer as a separate phase and is selected from linear low-density polyethylene and high-density polyethylene having a molecular weight of at least about 20,000 and a low-density polyethylene having a molecular weight of at least about 75,000; and

a particulate inorganic filler dispersed in the composition;

said composition being processable on calendering rolls to a thickness between about 1/4 and 5 millimeters, and in sheet form having a tensile strength of at least 10 kilograms per square centimeter and an abrasion loss in the test described herein of no more than about 5 grams;

the tensile strength downweb being significantly greater than the tensile strength crossweb.

12. Pavement-marking composition of claim 10 in which the non-crosslinked elastomer precursor comprises acrylonitrile-butadiene polymer.

13. Pavement-marking composition of claim 10 which further includes a thermoplastic extender resin that is miscible in, and forms a single phase with, the non-crosslinked elastomer precursor.

14. Pavement-marking composition of claim 13 in which said extender resin comprises a halogenated paraffin.

15. Pavement-marking composition of claim 14 in which the non-crosslinked elastomer precursor comprises acrylonitrile-butadiene polymer.

16. Pavement-marking composition of claims 10, 13, 14, 12 or 15 in which the filler comprises platelet fillers.

17. Pavement-marking composition of claims 10, 13, 14, 12 or 15 in which the filler is selected from magnesium silicate, talc or mica filler particles.