Hair care appliance with thermochromic hair curlers and method of manufacturing same

• US 5,606,983 A
• Filed: 12/02/1994
• Issued: 03/04/1997
• Est. Priority Date: 12/02/1994
• Status: Expired due to Term

• Current Assignee: Lawrence P. Monty, Patrick T. Monty
• Original Assignee: Lawrence P. Monty, Patrick T. Monty
• Inventors: Monty, Lawrence P., Monty, Patrick T.
• Primary Examiner(s): Mancene, Gene
• Assistant Examiner(s): Philogene, Pedro
• Application Number:
  US08/348,735
• Time in Patent Office: 823 Days
• Field of Search: 132/229, 132/233, 132/228, 132/245, 132/262, 132/269
• US Class Current: 132/229
• CPC Class Codes: A45D 2/362 with a heat accumulator, i.e. for heating before use
• CPC Class Codes: A45D 4/16 Independent devices characterised by heating the hair-curling or hair-waving means before use A45D1/20 takes precedence

Abstract

The hair care appliance of this invention has a housing, which holds a set of hair curlers and encloses electrical heating means for heating the curlers, and has a transparent cover which covers the set of curlers and the top of the housing. Each curler has a reversibly thermochromic thermoplastic elastomeric surface layer (around which hair is to be curled) which preferably covers a mandrel portion of a thermoplastic body. The thermoplastic body has ends of larger diameter than the mandrel portion of the body, and the mandrel may be hollow. A hollow mandrel may contain a double-walled metal core, which may contain a heat-retaining material. The elastomeric surface layer is preferably molded from an thermoplastic elastomer composition containing particulate thermochromic material, which preferably comprises reversibly thermochromic dye encapsulated in micro-capsules. The thermochromic dye components are chosen to be non-toxic and environmentally benign. The combination is preferably prepared to have a complete and distinct color change at a curler temperature optimum for curl retention. The colors within the preferred curling temperature range and outside that range are easily distinguished by users, even if they suffer from red/green color blindness. Thermochromic thermoplastic elastomer (TTPE) compositions for the curler mandrel surface layer are disclosed, along with a process for preparing such compositions. Preferred processes for manufacturing the curlers using the TTPE compositions are disclosed.

Claims

1. A hair curler comprising:

a) a hollow cylindrical core having first and second ends,

b) a hollow, substantially cylindrical plastic form enclosing said core except for at least one of said first and second ends, said form including a mandrel portion for winding of hair to be curled, said mandrel portion having an outer surface, and

c) a reversibly thermochromic layer covering at least said mandrel portion of said plastic form, said reversibly thermochromic layer having a first color indicative of a temperature within a range suitable for curling hair and a second color indicative of a temperature outside of said range.

2. A hair curler as in claim 1, wherein said first color is indicative of a temperature range between 94 degrees Celsius and 125 degrees Celsius.

3. A hair curler as in claim 1, wherein said second color is indicative of a temperature range around 20 degrees Celsius.

4. A hair curler as in claim 1, wherein said first color is indicative of a temperature range around 110 degrees Celsius.

5. A hair curler as in claim 1, wherein said first color is white and said second color is blue.

6. A hair curler as in claim 1, wherein said first and second colors are distinguishable by normal human color vision and by human vision characterized by red/green color blindness.

7. A hair curler as in claim 1, wherein said reversibly thermochromic layer (c) comprises:

a) 100 parts of a block copolymer having a polystyrene phase and a polyisoprene phase,

b) 50 to 200 parts of a plasticizer oil,

c) 0 to 200 parts of an inert particulate filler,

d) 1 to 5 parts of an anti-oxidant and UV stabilizer,

e) 0 to 10 parts of a lubricant,

f) 10 to 100 parts of a thermochromic particulate material, and

g) optionally, 0 to 100 parts of conventional dyes and pigments.

8. A hair curler as in claim 1, wherein said reversibly thermochromic layer (c) is between 0.5 millimeter and 2.0 millimeters thick.

9. A hair curler as in claim 1, further comprising a heating element contained within said hollow cylindrical core and surrounded by said substantially cylindrical plastic portion.

10. A hair curler as in claim 1, wherein said mandrel portion further comprises a reversibly thermochromic elastomer.

11. A hair curler as in claim 1, wherein said mandrel portion further comprises a reversibly thermochromic thermoplastic elastomer.

12. A hair curler as in claim 1, further comprising an integral heating element disposed within at least said mandrel portion.

13. A hair curler as in claim 1, wherein said reversibly thermochromic layer further comprises a thermoplastic elastomeric composition containing a reversibly thermochromic particulate material.

14. A hair curler as in claim 13, wherein said reversibly thermochromic layer further comprises an elastomeric composition containing 5% to 20% of said reversibly thermochromic particulate composition.

15. A hair curler as in claim 13, wherein said reversibly thermochromic layer further comprises an elastomeric composition containing about 10% of said reversibly thermochromic particulate composition.

16. A hair curler as in claim 13, wherein said reversibly thermochromic particulate composition further comprises micro-capsules containing a reversibly thermochromic substance.

17. A hair curler as in claim 16, wherein said micro-capsules contain a thermochromic dye.

18. A hair curler as in claim 16, wherein said micro-capsules contain a glucoside dye.

19. A hair curler as in claim 16, wherein said micro-capsules comprise an electron-donating chromagenic substance, an electron-accepting substance, and a solvent encapsulated by a hydrophilic high-molecular-weight compound.

20. A hair curler as in claim 16, wherein said micro-capsules have diameters of less than about 100 micrometers.

21. A hair curler as in claim 16, wherein said reversibly thermochromic substance comprises a substance selected from the list consisting of:

a) a composition further comprising;

i) an electron-donating chromagenic substance,

ii) an electron-accepting substance, and

iii) a solvent,

b) thermochromic esters of alkoxylated methyl glucosides,

c) thermochromic spirooxazepin-oxazine compounds,

d) thermochromic polyacetylenes,

e) thermochromic liquid-crystal esters,

f) combinations thereof with each other,

g) combinations thereof with conventional pigments, and

h) combinations thereof with conventional dyes.

22. A hair curler as in claim 13, wherein said thermoplastic elastomer comprises a material selected from the list consisting of:

a) a block copolymer having a polystyrene phase and a polyisoprene phase,

b) a block copolymer having a polystyrene phase and a butadiene phase,

c) a block copolymer having a polystyrene phase and an ethylene propylene phase, and

d) mixtures thereof.

23. A reversibly thermochromic hair curler, comprising:

a) a hollow cylindrical core having first and second ends,

b) a hollow cylindrical plastic portion enclosing said core except for at least one of said first and second ends, said cylindrical plastic portion including a mandrel portion for winding of hair to be curled, and

c) a reversibly thermochromic layer covering said mandrel portion of said cylindrical plastic portion,

said thermochromic layer further comprising a layer between 0.5 millimeter and 2.0 millimeters thick of a thermoplastic elastomer containing 5% to 20% by weight of a reversibly thermochromic particulate composition having at least one color indicative of a temperature range suitable for curling hair,

said particulate composition further comprising a reversibly thermochromic material encapsulated in micro-capsules having diameters of less than about 100 micrometers.

24. A personal care appliance, comprising:

a) a base, further comprising

i) a multiplicity of heating elements, each disposed to hold and heat a hair curler,

ii) conducting means for conducting electrical power to said multiplicity of heating elements, and

iii) an insulative enclosure supporting said multiplicity of heating elements and enclosing at least a portion of said conducting means,

b) a multiplicity of hair curlers adapted to fit over said heating elements, each of said hair curlers including a mandrel portion for winding of hair to be curled, said mandrel portion being characterized by a reversibly thermochromic surface, said reversibly thermochromic surface having a first color indicative of a temperature within a range suitable for curling hair and a second color indicative of a temperature outside of said range, and

c) a cover adapted to fit removably upon said base and over said multiplicity of curlers, at least a portion of said cover being transparent to provide a view of said multiplicity of said hair curlers.

25. A personal care appliance as in claim 24, wherein said first and second colors are distinguishable by normal human color vision and are distinguishable by human vision characterized by red/green color blindness.

26. A personal care appliance as in claim 24, wherein said first color is indicative of a temperature range between 94 degrees Celsius and 125 degrees Celsius.

27. A personal care appliance as in claim 24, wherein said second color is indicative of a temperature range around 20 degrees Celsius.

28. A personal care appliance as in claim 24, wherein said first color is indicative of a temperature range around 110 degrees Celsius.

29. A personal care appliance as in claim 24, wherein said first color is white and said second color is blue.