US3087832A - Transferable magnetic coating composition and transfer web coated therewith - Google Patents

Transferable magnetic coating composition and transfer web coated therewith Download PDF

Info

Publication number
US3087832A
US3087832A US77864158A US3087832A US 3087832 A US3087832 A US 3087832A US 77864158 A US77864158 A US 77864158A US 3087832 A US3087832 A US 3087832A
Authority
US
United States
Prior art keywords
coating
iron oxide
transfer
material
web
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
Inventor
Mark V Fogle
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NCR Corp
Original Assignee
NCR Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NCR Corp filed Critical NCR Corp
Priority to US77864158 priority Critical patent/US3087832A/en
Application granted granted Critical
Publication of US3087832A publication Critical patent/US3087832A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01FMAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
    • H01F41/14Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for applying magnetic films to substrates
    • H01F41/16Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for applying magnetic films to substrates the magnetic material being applied in the form of particles, e.g. by serigraphy, to form thick magnetic films or precursors therefor
    • GPHYSICS
    • G06COMPUTING; CALCULATING; COUNTING
    • G06KRECOGNITION OF DATA; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K1/00Methods or arrangements for marking the record carrier in digital fashion
    • G06K1/12Methods or arrangements for marking the record carrier in digital fashion otherwise than by punching
    • G06K1/125Methods or arrangements for marking the record carrier in digital fashion otherwise than by punching by magnetic means
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/62Record carriers characterised by the selection of the material
    • G11B5/68Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent
    • G11B5/70Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer
    • G11B5/702Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the bonding agent
    • G11B5/7023Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the bonding agent containing polyesters, polyethers, silicones, polyvinyl resins, polyacrylresins or epoxy resins
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S428/00Stock material or miscellaneous articles
    • Y10S428/90Magnetic feature
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S428/00Stock material or miscellaneous articles
    • Y10S428/914Transfer or decalcomania
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S52/00Static structures, e.g. buildings
    • Y10S52/04Magnetic connecting means for building components
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/31504Composite [nonstructural laminate]
    • Y10T428/31652Of asbestos
    • Y10T428/31663As siloxane, silicone or silane
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/31504Composite [nonstructural laminate]
    • Y10T428/31801Of wax or waxy material
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/31504Composite [nonstructural laminate]
    • Y10T428/31844Of natural gum, rosin, natural oil or lac

Description

April 30, 1963 WAX COATING COATING LAYER CONTAINING I POLYSILOXANE RESIN, POLYSILOXANE AGUM, AND IRON OXIDE PARTICLES FILM OR WEB BASE INVENTOR MARK V. FOG E m g/W HIS ATTORNEYS United States Patent This invention relates to a transferable magnetic coating composition and to a transfer web coated therewith.

'Dhe transfer web coated with the novel coating composition is used, coated side against a receiving material surface, and the transfer of (the coating material is [brought about by the impact of a type, or other marking instrument, in selected areas, applied either to the back of the transfer web or to the back of the receiving material, to cause break-away of the coating from the web and adherence of such brokenaaway material to the receiving surface.

it is important that as much magnetic material be transfer-red cleanly and well defined by the marking instru ment as is possible, consistent with the area of [the mark to be made, so that the largest possible signal may be magnetically impressed on and sensed from a given recorded mark, and it is a main feature of this invention that complete transfer of the magnetic material be made to the receiving surface. It is within the bounds of use of this coated trans-fer web to pre-m-agnetize it so the transferred material is already in a magnetized condition or the magnetic material may be magnetized in the desired polarity after being transferred. It will be apparent that the marking instrument itself, if made of magnetizable material, could be used to magnetize the transferred material in the desired polarity as it is being transferred. The FIGURE in the drawing exemplifying the product of this invention is a cross-sectional view of a film or web base material coated with a first layer containing a homogeneous blend of a solid polysiloxane resin, a linear polysiloxane gum, and magnetic iron oxide particles, said first layer being overcoated with a thin second layer of wax.

In the best practice, the web material on which the novel transfer composition is coated is thin paper, thin foil of metal, or thin film of film-forming polymer material, that, because of its thinness and pliability, responds to the marking impacts applied thereto, the consequent distortion of the base web material aiding in the breakaway of the magnetic coating composition therefrom, and its transfer and adherence to the receiving surface.

The magnetic component of the magnetic coating composition is dispersed in a binder material dissolved in a readily evaporable liquid vehicle to form a solution-dispersion that may be applied to a supporting web material and dried to a solid coating at room temperature. The binder material is a pliable linear dimethyl-siloxane polymer which has had mixed therewith an embrittling compound of the polysiloxane methyl and/or methyl-phenyl derivative type, the polysiloxane structure giving the embrittling characteristics to it.

After the base web has been coated with the magnetic coating composition, and allowed to dry, an over-coating of a waxy material such as paraffin wax of a fraction that is solid at room temperature (about degrees centigrade), is applied in a very thin coating to prevent the blocking or sticking together of the turns of a coil of such coated web and, additionally, to aid in the adherence of the transferred magnetic composition to the receiving surface.

3,087,832 Patented Apr. 30,, 1963 The linear dimethyl-siloxane polymer has the general formula and is of such length as to give the material pliability in the hands, at room temperature (ZOdegrees centigrade). This polymer is a clear viscous gum with a plasticity number ranging from to 120 as measured with the Williams plasticity number test (AST-M, D926, room temperature for three minutes.

The solid embrittling resin that preferably is used is the mentioned methyl and/ or methyl-phenyl polysiloxane having the general formula Grams Toluene 5200 Dimethyl-siloxane polymer gum SE-76 605 Polysiloxane resin R-S 071, as disclosed in United States Patent No. 2,718,483 336 Black magnetic iron oxide powder 1043 and plasticized with a compatible silicone oil, if necessary, to achieve the required transfer and handling characteristics. It will be apparent that the iron oxide constitutes about half of the solids of the preferred composition, by weight, and that of the other solids which constitute the binder, the resin consitutes about one-third, although great variations are permissible in these relative amounts. The characteristic sought for in the coating on the web is its easy and complete transfer from the supporting web to the receiving surface.

The foregoing composition is applied to the supporting web, as a liquid slurry, to give a coating, when dried, of about 0.0001 of an inch. On top of the dried coating is coated a film of paraflin wax, which coating need not be more than 0.00005 of an inch in thickness. Tissue paper, such as is used in making carbon transfer sheets, of a thickness of 0.0005 of an inch, makes a very suitable supporting web. Yoshino paper is commonly used for such a web.

The foregoing preferred example may be modified considerably with regard to the relative proportions of material used. For instance, the variations of the relative amounts of materials used may well be within the following percentages, by weight:

Dimethyl-silicone polymer, as specified, up to 60 Polysiloxane resin, as specified, up to 50 Black magnetic iron oxide, or equivalent, up to Toluene, or other rapidly evaporable vehicle, to make a coating slurry.

characteristics, or characteristics more to be desired for a particular intended use. Among the magnetic material 3. substitutes for iron oxide are ferrite materials, cobaltnickel alloys, iron, steel, and the like, in powdered form.

It is well known to use powdered magnetic materials in a transfer composition andin transfer webs coated with such as disclosed in United States Patent No. 2,744,031, which issued on the application of Robert E. Mumma, May 1, 1956, the novelty of the present invention over what is disclosed in said patent, being the use of such magnetic materials in combination with the named silicone derivative polymers which give greatly improved transfer characteristics.

What is claimed is:

1. As an article of manufacture, a thin pliable web of transfer coating supporting material having coated on a surface thereof a mixture of black magnetic iron oxide powder and a binder material consisting of linear dimethyl silicone polymer gum and a solid polysiloxane resin as. an embrittling component, the iron oxide constituting about half the weight of the coating and the resin about one-third the weight of the binder, the outer surface of the coating having a thin coating of wax to aid in the adherence of the iron oxide and binder to a receiving sheet.

2. A coated web as in claim 1 in which the coating is modified by the addition thereto of a plasticizing silicone oil to give it the desired consistency.

3. A transfer coating for liquid application to a transfer Web at room temperature and which will dry to a solid film thereon at room temperature, consisting of, in proportional parts by weight: 605 parts of a linear dimethyl siloxane polymer gum; 336 parts of solid methylphenyl substituted polysiloxane resin; 1,043 parts of black magnetic iron oxide powder; and a sulficient amount of rapidly-evaporable vehicle to make a coating slurry.

References Cited in the file of this patent UNITED STATES PATENTS 2,744,031 Mumma May 1, 1956 2,777,781 Kordig Jan. 15, 1957 2,820,717 Newman Jan. 21, 1958 2,866,711 Hart Dec, 30, 1958 2,875,098 Blatz Feb. 24, 1959 2,912,344 Newman et a1 Nov. 10, 1959

Claims (1)

1. AS AN ARTICLE OF MANUFACTURE, A THIN PLIABLE WEB OF TRANSFER COATING SUPPORTING MATERIAL HAVING COATED ON A SURFACE THEREOF A MIXTURE OF BLACK MAGNETIC IRON OXIDE POWER AND A BINDER MATERIAL CONSISTING OF LINEAR DIMETHYL SILICONE POLYMER FUM AND A SOLID POLYSILOXANE RESIN AS AN EMBRITTLING COMPONENT, THE IRON OXIDE CONSITUTING ABOUT HALF THE WEIGHT OF THE COATING AND THE RESIN ABOUT ONE-THIRD THE WEIGHT OF THE BINDER, THE OUTER SURFACE OF THE COATING HAVING A THIN COATING OF WAX TO AID IN THE ADHERENCE OF THE IRON OXIDE AND BINDER TO A RECEIVING SHEET.
US77864158 1958-12-08 1958-12-08 Transferable magnetic coating composition and transfer web coated therewith Expired - Lifetime US3087832A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US77864158 US3087832A (en) 1958-12-08 1958-12-08 Transferable magnetic coating composition and transfer web coated therewith

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US77864158 US3087832A (en) 1958-12-08 1958-12-08 Transferable magnetic coating composition and transfer web coated therewith
CH8144159A CH395729A (en) 1958-12-08 1959-12-04 Material for the application of marks on a receiving surface

Publications (1)

Publication Number Publication Date
US3087832A true US3087832A (en) 1963-04-30

Family

ID=25114000

Family Applications (1)

Application Number Title Priority Date Filing Date
US77864158 Expired - Lifetime US3087832A (en) 1958-12-08 1958-12-08 Transferable magnetic coating composition and transfer web coated therewith

Country Status (2)

Country Link
US (1) US3087832A (en)
CH (1) CH395729A (en)

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3214285A (en) * 1962-08-10 1965-10-26 Pacific Ind Inc Method of pressure transfer sheet and resulting article
US3340086A (en) * 1959-08-17 1967-09-05 Groak Josef Transfer systems
US3386847A (en) * 1964-10-16 1968-06-04 Burroughs Corp Silicone release coating transfer paper
US3387986A (en) * 1965-04-01 1968-06-11 Ibm Transfer medium for typing on non-receptive surfaces
US3505955A (en) * 1966-01-17 1970-04-14 Gerhard Ritzerfeld Method and arrangement for producing printing forms
US3857720A (en) * 1973-02-08 1974-12-31 Ncr Co Polysiloxane coated transfer base
US3862047A (en) * 1970-08-05 1975-01-21 Gen Dynamics Corp Method and composition for detecting flaws in metallic surfaces, holes and otherwise
FR2311834A2 (en) * 1975-05-22 1976-12-17 Gen Electric Article self-adhesive provided with a peelable protective layer
US4039707A (en) * 1973-05-29 1977-08-02 General Electric Company Article comprising a silicone pressure-sensitive adhesive and a releasable anti-stick layer and process of using same
US4049860A (en) * 1975-11-19 1977-09-20 Hoffmann & Engelmann Paper support carrying anti-adhesive layer
US4064313A (en) * 1976-12-17 1977-12-20 Rank Xerox Ltd. Heat fixing member for electrophotographic copiers
US4096314A (en) * 1975-06-06 1978-06-20 Kores Holding Zug Ag Pressure-sensitive transfer sheet
US4110300A (en) * 1976-11-12 1978-08-29 Toray Silicone Company, Ltd. Self-extinguishing silicone rubber compositions
US4153753A (en) * 1976-08-20 1979-05-08 Trevor P. Woodman Spectrally selective surfaces and method of fabricating the same
US4643917A (en) * 1983-11-02 1987-02-17 Konishiroku Photo Industry Co., Ltd. Heat-sensitive transfer recording medium
US5292593A (en) * 1992-04-06 1994-03-08 Ncr Corporation Transfer ribbon for use with a thermal printer or with an impact printer
US5752357A (en) * 1991-11-11 1998-05-19 Piller; Helmut Method for the reversibly fixing a covering to a supporting surface, and parts and materials suitable for carrying out the method

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2744031A (en) * 1949-10-15 1956-05-01 Ncr Co Sheet having a transferable coating containing magnetizable material
US2777781A (en) * 1955-03-04 1957-01-15 Ditto Inc Transfer sheet having waxy top protective coating
US2820717A (en) * 1953-08-17 1958-01-21 Columbia Ribbon Carbon Mfg Manifold sheet and composition therefor
US2866711A (en) * 1956-03-30 1958-12-30 Moore Business Forms Inc Carbon paper inks and method for making same
US2875098A (en) * 1955-07-18 1959-02-24 Du Pont Coated polymeric thermoplastic dielectric film
US2912344A (en) * 1957-10-11 1959-11-10 Columbia Ribbon Carbon Mfg Pressure-sensitive transfer element for placing smudge-resistant marks

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2744031A (en) * 1949-10-15 1956-05-01 Ncr Co Sheet having a transferable coating containing magnetizable material
US2820717A (en) * 1953-08-17 1958-01-21 Columbia Ribbon Carbon Mfg Manifold sheet and composition therefor
US2777781A (en) * 1955-03-04 1957-01-15 Ditto Inc Transfer sheet having waxy top protective coating
US2875098A (en) * 1955-07-18 1959-02-24 Du Pont Coated polymeric thermoplastic dielectric film
US2866711A (en) * 1956-03-30 1958-12-30 Moore Business Forms Inc Carbon paper inks and method for making same
US2912344A (en) * 1957-10-11 1959-11-10 Columbia Ribbon Carbon Mfg Pressure-sensitive transfer element for placing smudge-resistant marks

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3340086A (en) * 1959-08-17 1967-09-05 Groak Josef Transfer systems
US3214285A (en) * 1962-08-10 1965-10-26 Pacific Ind Inc Method of pressure transfer sheet and resulting article
US3386847A (en) * 1964-10-16 1968-06-04 Burroughs Corp Silicone release coating transfer paper
US3387986A (en) * 1965-04-01 1968-06-11 Ibm Transfer medium for typing on non-receptive surfaces
US3505955A (en) * 1966-01-17 1970-04-14 Gerhard Ritzerfeld Method and arrangement for producing printing forms
US3862047A (en) * 1970-08-05 1975-01-21 Gen Dynamics Corp Method and composition for detecting flaws in metallic surfaces, holes and otherwise
US3857720A (en) * 1973-02-08 1974-12-31 Ncr Co Polysiloxane coated transfer base
US4039707A (en) * 1973-05-29 1977-08-02 General Electric Company Article comprising a silicone pressure-sensitive adhesive and a releasable anti-stick layer and process of using same
FR2311834A2 (en) * 1975-05-22 1976-12-17 Gen Electric Article self-adhesive provided with a peelable protective layer
US4096314A (en) * 1975-06-06 1978-06-20 Kores Holding Zug Ag Pressure-sensitive transfer sheet
US4049860A (en) * 1975-11-19 1977-09-20 Hoffmann & Engelmann Paper support carrying anti-adhesive layer
US4153753A (en) * 1976-08-20 1979-05-08 Trevor P. Woodman Spectrally selective surfaces and method of fabricating the same
US4110300A (en) * 1976-11-12 1978-08-29 Toray Silicone Company, Ltd. Self-extinguishing silicone rubber compositions
US4064313A (en) * 1976-12-17 1977-12-20 Rank Xerox Ltd. Heat fixing member for electrophotographic copiers
US4643917A (en) * 1983-11-02 1987-02-17 Konishiroku Photo Industry Co., Ltd. Heat-sensitive transfer recording medium
US5752357A (en) * 1991-11-11 1998-05-19 Piller; Helmut Method for the reversibly fixing a covering to a supporting surface, and parts and materials suitable for carrying out the method
US5292593A (en) * 1992-04-06 1994-03-08 Ncr Corporation Transfer ribbon for use with a thermal printer or with an impact printer

Also Published As

Publication number Publication date
CH395729A (en) 1965-07-15

Similar Documents

Publication Publication Date Title
US4391853A (en) Methods of making adhesive articles and resulting products
US4913946A (en) Fluorescent adhesive tape for use as a highlighter
US4436809A (en) Method for light-shielding a roll photographic film
US5503905A (en) Tick pattern for simulated wood transfer films and method of making same
CA1158104A (en) Tamper-indicating sheet
EP0188635A1 (en) Thermochromic composition
JPS57174296A (en) Heat transfer magnetic recording medium
JPS63268777A (en) Microencapsulated ink composition
WO1993024241A1 (en) Fabric with reversible enhanced thermal properties
EP0060025A2 (en) Temperature indicator
CA1176988A (en) Coating composition
KR950703031A (en) WATERBORNE COATING COMPOSITIONS HAVING IMPROVED METALLIC PIGMENT ORIENTATION With Improved Metallic Pigment Orientation
GB914703A (en) Reversal type electroscopic developer powder
EP0276147A3 (en) Toner and developer compositions with long chain alcohol waxes
JPS5551583A (en) Ink-jet recording paper
GB865184A (en) Improvements in or relating to printers' make-ready
US4171398A (en) Transfer sheet
KR940005733A (en) Gas barrier resin composition and film thereof and preparation method thereof
US3107174A (en) Heat sensitive copy sheet and method of making
JPH0366773A (en) Flexible multi-layer marker tape and preparation thereof
GB1046411A (en) Transfer materials
JPS55145746A (en) Aqueous polymer dispersion* paper coating composition and coated paper product made therewith
US2872340A (en) Transfer element and method of making the same
US4318953A (en) Transfer materials
US4985302A (en) Removable self-adhesive sheet with writable surface