GB2114934A - Sheet for use in a magnetic recording tape cassette - Google Patents

Sheet for use in a magnetic recording tape cassette Download PDF

Info

Publication number
GB2114934A
GB2114934A GB08302171A GB8302171A GB2114934A GB 2114934 A GB2114934 A GB 2114934A GB 08302171 A GB08302171 A GB 08302171A GB 8302171 A GB8302171 A GB 8302171A GB 2114934 A GB2114934 A GB 2114934A
Authority
GB
United Kingdom
Prior art keywords
sheet
magnetic recording
base sheet
recording tape
base
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.)
Granted
Application number
GB08302171A
Other versions
GB2114934B (en
GB8302171D0 (en
Inventor
Haruo Shiba
Toshihiko Ishida
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.)
TDK Corp
Original Assignee
TDK 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 TDK Corp filed Critical TDK Corp
Publication of GB8302171D0 publication Critical patent/GB8302171D0/en
Publication of GB2114934A publication Critical patent/GB2114934A/en
Application granted granted Critical
Publication of GB2114934B publication Critical patent/GB2114934B/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/62—Record carriers characterised by the selection of the material
    • G11B5/73—Base layers, i.e. all non-magnetic layers lying under a lowermost magnetic recording layer, e.g. including any non-magnetic layer in between a first magnetic recording layer and either an underlying substrate or a soft magnetic underlayer
    • G11B5/739—Magnetic recording media substrates
    • G11B5/73923—Organic polymer substrates
    • G11B5/73925—Composite or coated non-esterified substrates
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
    • B32B5/16—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by features of a layer formed of particles, e.g. chips, powder or granules
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/62—Record carriers characterised by the selection of the material
    • G11B5/72—Protective coatings, e.g. anti-static or antifriction
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/62—Record carriers characterised by the selection of the material
    • G11B5/73—Base layers, i.e. all non-magnetic layers lying under a lowermost magnetic recording layer, e.g. including any non-magnetic layer in between a first magnetic recording layer and either an underlying substrate or a soft magnetic underlayer
    • G11B5/739—Magnetic recording media substrates
    • G11B5/73923—Organic polymer substrates
    • G11B5/73927—Polyester substrates, e.g. polyethylene terephthalate
    • G11B5/73931—Two or more layers, at least one layer being polyester
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2264/00—Composition or properties of particles which form a particulate layer or are present as additives
    • B32B2264/10—Inorganic particles
    • B32B2264/107—Ceramic
    • B32B2264/108—Carbon, e.g. graphite particles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/20—Properties of the layers or laminate having particular electrical or magnetic properties, e.g. piezoelectric
    • B32B2307/21—Anti-static
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/40—Properties of the layers or laminate having particular optical properties
    • B32B2307/412—Transparent
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2429/00—Carriers for sound or information
    • B32B2429/02—Records or discs

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Wood Science & Technology (AREA)
  • Laminated Bodies (AREA)
  • Magnetic Record Carriers (AREA)
  • Adhesive Tapes (AREA)

Abstract

A sheet for a use as the base for a magnetic tape cassette comprises a first base sheet (1), a sliding layer (2) provided on the upper surface of said first base sheet, a second base sheet (3), and an antistatically treated sheet (4) laminated on the lower surface of said second base sheet. The antistatic sheet may be of carbon powder and can be incorporated with the base sheet (3). The sliding layer is preferably of silicone. <IMAGE>

Description

SPECIFICATION Sheet for cassette type magnetic recording tape This invention relates to a sheet for a cassette type magnetic recording tape having an improved resistance against peeling of a sliding layer from the base sheet.
It has been well known to render the surface of the base sheet of the cassette type magnetic recording tape to be highly slidabie so as to secure its stable running on the magnetic head. As a method for improving such sliding property, there has widely been adopted one, wherein silicon is coated in layer on the base sheet. On the other hand, it has also been known to coat antistatic agent on the base sheet, or mix it into the material for the base sheet for antistatic treatment.
However, when the thus antistatically treated base sheet is subjected to the silicon coating, the antistatic agent exudes out with the lapse of time with the consequence that the silicon layer as coated thereon is floated and peeled off to reduce the sliding effect of the magnetic tape.
As the result of studies and experiments towards improvement in the various disadvantages, as mentioned above, with the base sheet for the magnetic tape having the sliding layer formed on its upper surface, the present inventors have found out that, by kneading an antistatic agent into the base sheet having the sliding layer on its upper surface, or by laminating a sheet coated with the antistatic agent on the lower surface of the base sheet, there can be provided a practially desirable sheet for the magnetic recording tape which has effectively solved the above mentioned shortcomings, and secures the stable running property of the magnetic tape without the peeling phenomenon of the sliding layer being taken place with its use over a long period of time.
It is therefore the primary object of the present invention to provide an improved base sheet for the cassette type magnetic recording tape free from all these disadvantages as mentioned above.
According to the present invention, in general aspect of it, there is provided a sheet for a cassette type magnetic recording tape which comprises in combination a first base sheet, a sliding layer placed on the upper surface of said first base sheet, a second base sheet, and an antistatically treated sheet laminated on the lower surface of said second base sheet.
The foregoing object, other objects as well as specific construction of the cassette type magnetic recording tape according to the present invention and the materials for use in manufacturing such tape will become more apparent and understandable from the following detailed description thereof, when read in conjunction with the accompanying drawing.
In the accompanying drawing, single Figure 1 is a longitudinal cross-section of one embodiment of the base sheet for the cassette type magnetic recording tape according to the present invention, wherein reference numeral 1 designates an upper sheet of base material, a numeral 2 refers to a sliding layer, 3 denotes a lower sheet of the base material, 4 refers to a layer of antistatic agent, and 5 indicates a layer of adhesive agent.
In the following, the present invention will be explained in detail in reference to the accompanying drawing.
For the upper and lower sheets for the cassette type magnetic recording tape according to the present invention, there may be used various base material of synthetic resins such as, for example, polyethylene terephthalate, polypropylene, polyethylene of ultrahigh molecular weight, polycarbonate, polymethylene terephthalate, and so on.
The base sheet having the sliding layer is such one that a peelable silicon material, for example, has been coated on its upper surface, and the antistatically treated sheet is such one, in which the antistatic agent, e.g., carbon powder, has been coated on the lower surface thereof, or such one, in which the antistatic agent has been added into and kneaded with the base material in advance, followed by forming the material into a sheet.
These two sheets, when they are in such a structure that the upper base sheet has the sliding layer coated on its top surface and the lower base sheet has the antistatically treated layer formed by coating the antistatic agent placed on the lower surface thereof, are integrally laminated, wherein the antistatic coating layer constitutes the lower surface of the tape. While the lamination of these both sheets can be done in any arbitrary manner as has been used conventionally, it can be advantageously done, from the industrial standpoint, by fusion-bonding them together under heat, or sticking together with use of an adhesive agent. The adhesive agent for use may be arbitrarily chosen depending on whether the base material for both sheets is same or different in quality, or depending on the kind of the resin constituting the base material.
In the following, explanations will be given as to a preferred embodiment of the sheet for the cassette type magnetic recording tape according to the present invention in reference to the accompanying drawing.
Figure 1 shows a longitudinal cross-section, in part, of one embodiment of the sheet for the cassette type magnetic recording tape of the present invention, wherein the sliding layer 2 like a silicon coating is formed on the upper surface of the base sheet 1, and the antistatic coating layer 4 is formed on the lower surface of the base sheet 3, both base sheets being integrally and rigidly joined together through the adhesive layer 5.
Thus, the laminated sheet for the cassette type magnetic recording tape according to the present invention is not liable to exfoliation of the silicon sliding layer from the base sheet during its use over a long period of time due to exudation of the antistatic agent, hence the stable running of the magnetic tape is secured in its use over a long period of time, and the magnetic recording tape can enjoy its high practical utility. The sheet for the cassette type magnetic tape according to the present invention has, in general, its surface fixed resistance of 1013 or below and no exfoliation of the sliding layer occurs even after 1,000 times of passage of the recording tape on the magnetic head, hence it is highly suitable as the sheet for the cassette type magnetic recording tape.
Further, the sheet for the cassette type magnetic recording tape according to the present invention, when it is made of the base sheets, the antistatic agent, and the adhesive agent, all having good transparency, can be made into a transparent tape, thereby making it possible to provide the cassette type magnetic recording tape of very advanced design.
Although, in the foregoing, the present invention has been described with reference to a preferred embodiment thereof, it should be understood that the embodiment is merely illustrative and not restrictive, and that any changes and modifications may be made within the spirit and scope of the invention as set forth in the appended claims.

Claims (2)

1. A sheet for a cassette type magnetic recording tape, which comprises in combination: a first base sheet, a sliding layer provided on the upper surface of said first base sheet, a second base sheet, and an antistatically treated sheet laminated on the lower surface of said second base sheet.
2. The sheet for the cassette type magnetic recording tape according to Claim 1, which is made up of base sheets, antistatic agent, and adhesive agent, all being transparent, so as to render the entire magnetic tape to be perfectly transparent.
GB08302171A 1982-02-23 1983-01-26 Sheet for use in a magnetic recording tape cassette Expired GB2114934B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1982024503U JPS58127464U (en) 1982-02-23 1982-02-23 Sheet for magnetic tape cassettes

Publications (3)

Publication Number Publication Date
GB8302171D0 GB8302171D0 (en) 1983-03-02
GB2114934A true GB2114934A (en) 1983-09-01
GB2114934B GB2114934B (en) 1985-06-12

Family

ID=12139991

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08302171A Expired GB2114934B (en) 1982-02-23 1983-01-26 Sheet for use in a magnetic recording tape cassette

Country Status (4)

Country Link
JP (1) JPS58127464U (en)
DE (1) DE3306089A1 (en)
GB (1) GB2114934B (en)
NL (1) NL8300248A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0150406A1 (en) * 1984-01-20 1985-08-07 BASF Aktiengesellschaft Tape cassette, in particular magnetic tape cassette and its liner sheet
US4624423A (en) * 1984-05-19 1986-11-25 Basf Aktiengesellschaft Tape cassette with liner

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5561212A (en) * 1993-03-05 1996-10-01 Baylor University Poly(methylene oxalate), a new composition of matter
US5451643A (en) * 1993-03-05 1995-09-19 Baylor University Poly(alkylene dicarboxylates) and synthesis thereof
US5371171A (en) * 1993-03-05 1994-12-06 Baylor University Poly(methylene oxalate) and precursors thereto

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS537115Y2 (en) * 1973-05-22 1978-02-22

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0150406A1 (en) * 1984-01-20 1985-08-07 BASF Aktiengesellschaft Tape cassette, in particular magnetic tape cassette and its liner sheet
US4709290A (en) * 1984-01-20 1987-11-24 Basf Aktiengesellschaft Tape cassette, in particular a magnetic tape cassette, and a support liner therefor
US4624423A (en) * 1984-05-19 1986-11-25 Basf Aktiengesellschaft Tape cassette with liner

Also Published As

Publication number Publication date
JPS58127464U (en) 1983-08-29
DE3306089A1 (en) 1983-09-01
GB2114934B (en) 1985-06-12
GB8302171D0 (en) 1983-03-02
NL8300248A (en) 1983-09-16

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Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee

Effective date: 19950126