CA2158805A1 - Composites of polytetrafluoroethylene, intermediate products for these and processes for their production - Google Patents

Composites of polytetrafluoroethylene, intermediate products for these and processes for their production

Info

Publication number
CA2158805A1
CA2158805A1 CA002158805A CA2158805A CA2158805A1 CA 2158805 A1 CA2158805 A1 CA 2158805A1 CA 002158805 A CA002158805 A CA 002158805A CA 2158805 A CA2158805 A CA 2158805A CA 2158805 A1 CA2158805 A1 CA 2158805A1
Authority
CA
Canada
Prior art keywords
ptfe
shaped article
plastic
melt
production
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.)
Abandoned
Application number
CA002158805A
Other languages
French (fr)
Inventor
Wolfgang Michel
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.)
Dyneon GmbH
Original Assignee
Hoechst AG
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 Hoechst AG filed Critical Hoechst AG
Publication of CA2158805A1 publication Critical patent/CA2158805A1/en
Abandoned legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00Layered products comprising a layer of synthetic resin
    • B32B27/12Layered products comprising a layer of synthetic resin next to a fibrous or filamentary layer
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00Layered products comprising a layer of synthetic resin
    • B32B27/32Layered products comprising a layer of synthetic resin comprising polyolefins
    • B32B27/322Layered products comprising a layer of synthetic resin comprising polyolefins comprising halogenated polyolefins, e.g. PTFE
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B7/00Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
    • B32B7/04Interconnection of layers
    • B32B7/12Interconnection of layers using interposed adhesives or interposed materials with bonding properties
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16CSHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/02Parts of sliding-contact bearings
    • F16C33/04Brasses; Bushes; Linings
    • F16C33/20Sliding surface consisting mainly of plastics
    • F16C33/201Composition of the plastic
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B32LAYERED PRODUCTS
    • B32BLAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2327/00Polyvinylhalogenides
    • B32B2327/12Polyvinylhalogenides containing fluorine
    • B32B2327/18PTFE, i.e. polytetrafluoroethylene

Abstract

Composite bodies of polytetrafluoroethylene (PTFE) which have a surface with good surface slip comprise layers, one on top of the other, of a) PTFE, b) a copolymer which has predominantly tetrafluoroethylene units and acts as a hot-melt adhesive with respect to the PTFE, c) a fiber material which is stable up to at least 400°C and d) at least one plastic which can be processed as a melt. For this, layers a) to c) are first compression-molded at about 350 to 400°C, after which the intermediate product thus obtained can be compression-molded in one or more steps with the plastic or plastics which can be processed as a melt.

Description

HOECHST AKLl~SELLSCHAFT HOE 94/F 923 Dr.RL-nu Werk Gendorf Composites of polytetrafluoroethylene, intermediate products for these and processes for their production Description Polytetrafluoroethylene, PTFE in the following, is a valuable material not least because of its powerful antia & esive properties and its high melt viscosity.
However, these properties make hon~; ng with other materials exceptionally difficult. Thus, the low surface tension of PTFE does not allow wetting by a & esives, and welding as a rule fails because of the high melt viscos-ity, which necessitates welding temperatures in the region of 370C, which is detrimental to many of the materials to be hon~e~ with it, in particular plastics.

The invention was thus based on the object of producing composite bodies or shaped articles in which PTFE is firmly h~n~eA to a lower-melting plastic, where this plastic can also be very much less heat-stable than PTFE.

This object is achieved according to the invention by compression-molding at a temperature of 350 to about 400C a layer of PTFE with a copolymer which is arranged in a flat form, has predominantly tetrafluoroethylene (TFE) units and acts as a hot-melt a & esive with respect to PTFE, and a fiber material which is arranged in a flat form, and is stable up to at least 400C. The copolymer is expediently employed for this purpose in the form of a film. It can also be applied to the PTFE in the form of granules or a powder, but it must then be ensured that the copolymer does not substantially melt around the fiber material on the opposite side of the sheet-like structure formed.

The intermediate product thus obt~; n~ is storage-stable and can be marketed in the form of rolls or sheets, depending on the thickness.

However, the intermediate product can also be further processed to give the end product, the composite body or shaped article, directly, if necessary after cooling to a suitable temperature, which depends on the properties of the plastic to be bonded to it. For this, the plastic which can be processed as a melt, arranged in a flat form, is compression molded with the intermediate pro-duct. "Arranged in a flat form" in the following andabove is understood as meaning a film or a layer of a powder or granules, or of a paste, and also a sheet. The processing temperature and the compression molding pressure depend on the nature and amount of the plastic which can be processed as a melt and are to be chosen by the expert according to his technical knowledge or to be determined with the aid of simple preliminary experi-ments. During this procedure, the plastic melts around the side of the fiber material arranged in a flat form which has remained exposed, a sheet-like structure (laminate) which is bonded inseparably and has outstand-ing properties being formed. The sheet-like structures thus obtained can in turn be further laminated - on the side of the lower-melting plastic - for example by compression molding with a film of the same plastic or a plastic which is compatible with this.

Preferred embodiments of the invention are explained in more detail below.

The PTFE is employed as a film or sheet of greater or lesser thickness, depending on the intended use of the composite body. If necessary, to eliminate unevenness in the surfaces of the PTFE material and/or of the compres-sion mold, a suitable intermediate layer can be intro-duced between the mold and the composite, for example a sheet-like structure - which is of course sufficiently heat-stable - of a silicone material, for example of a 215880~

silicone rubber/glass fiber fabric laminate.

Possible copolymers which act as hot-melt adhesives with respect to PTFE are primarily the copolymers which have already been employed to date for composites of PTFE with itself or other materials, that is to say copolymers having perfluoroalkyl perfluorovinyl ether units (US-A
3 946 136) or a perfluoroalkene which differs from TFE, such as hexafluoropropene (US-A 2 833 686). Copolymers of 90 to 99.5% by weight of TFE and 0.5 to 10% by weight of perfluoroalkyl perfluorovinyl ether having alkyl radicals of 1 to 10 carbon atoms, in particular 1 to 3 carbon atoms, are particularly preferred. Copolymers of 95 to 99% by weight of TFE and 5 to 1~ by weight of perfluoro-(alkyl vinyl) ether are particularly suitable.

Suitable fiber materials are woven fabrics or nonwovens of sufficiently heat-stable fibers of glass, ceramic, carbon, metal, such as stainless steel, or plastics which have a high heat stability, such as condensation products of terephthalic acid and p-phenylenediamine.

It is decisive that the fiber material arranged in a flat form allows mechanical anchoring for the melt and can thus act as the bonding member or intermediate layer between the PTFE and the plastic which can be processed as a melt. It is thus also possible, for example, first to bring more or less loose fibers into a flat form, with, for example pulverulent, copolymer which acts as a hot-melt adhesive, and then to use this as the basis for the process according to the invention.

Plastics which can be processed as a melt and which can be employed are all the customary industrial thermo-plastics, for example the relatively low-melting polymers poly(vinyl chloride) (PVC), polyethylene or polypropylene, processing depending on the properties of this plastic. Cooling of the intermediate product to the suitable further processing temperature will therefore in 215880~

general be necesæary.

One embodiment of the invention relates to lamination of the interme~;ate product with a paste of a plastic which can be processed as a melt, in particular a PVC paste.
The layer thickness of the paæte applied can vary: if the layer is to serve merely as a binder for a subsequently applied sheet-like structure - film or sheet - of the same plastic or of a plastic compatible with this, a layer thickness of up to about 100 ~m, preferably 50 to 80 ~m, is sufficient. The product thus obtained can then be further processed directly or, after cooling, at a later point in time. However, the layer thickness of the lamination can also be a few millimeters, for example up to 3 mm, whereupon correspo~; ng sheets are obtained after cooling. Suitable pastes of plastic are known to the expert. PVC pastes are described, for example, in DE-A 42 26 289 and the literature mentioned therein.

In a particular embodiment of the process, however, further processing to give the composite body can also be carried out with sufficiently heat-stable plastics in one step, for example with liquid-crystal polymers, such as completely aromatic copolyesters.

The most favorable processing conditions depend on the properties of the starting materials employed. The pressure is thus expediently also maintained during cooling. It may be advantageous to carry out the compres-sion molding under inert gas protection or under reduced atmospheric pressure. The formation of bubbles or hollow cavities can thus be suppressed by lamination in vacuo.
The process can be carried out industrially on the known laminating machines. Vacuum multilayer presses or twin-belt presses, if continuous laminates are to be produced from roll to roll, have proved suitable.

The composite bodies thus obtained are distinguished by advantageous properties, which often go beyond those of the components. Thus, for example, a thermal expansion similar to that of steel or ceramic can be achieved in composite bodies having a thin PTFE layer. The load capacity under pressure is very high. The heat distortion point and the welding properties can be adjusted within wide limits.

The thickness of the composite bodies according to the invention can likewise vary within wide limits and can be less than 100 ~m up to several millimeters.

Since all the composite bodies are based on the known good properties of PTFE, they are particularly suitable as a sliding bearing material.

The invention is explained in more detail in the follow-ing Examples.

Example 1 (inter~e~;ate product) - A glass silk fabric, 192 g/m2 (type 91121 from Inter-glas), - a film of a polymer of 96% by weight of TFE and 4~ by weight of perfluoro(n-propyl vinyl) ether, melt flow index (MFI) 10 g/minute at 372C under a load of 5 kg, thickness 25 ~m and - a PTFE sheet, thickness about 2 mm, dimensions of all the specimens 300 x 180 mm, were introduced into a vacuum multilayer press - from the top downwards.

As pressure compensation against slight unevenness in the press platen plates, a glass fiber fabric/silicone rubber laminate about 3 mm thick was placed on the PTFE sheet.

Heating up from room temperature to 370C (which was maintained for 12 minutes) took place in the course of about 35 minutes. Thereafter, the press was cooled to 230C by air cooling in the course of about 85 minutes, and then cooled to about 30C in the course of a further 60 minutes. The mean specific compression molding pres-sure was 0.6 bar (0.5 to 0.8 bar).

Strips 20 mm wide were cut off from the intermediate product thus obtained and the peel resistance was tested at a pull-off rate of 100 mm/minute in an angled peel test analogous to DIN 53 282. The peel resistance was 25 to 40 N/10 mm strip width.

Example 2 (further processing of the intermediate product) An 80 ~m thick layer of a PVC paste i8 knife-coated onto the glass fiber side of the intermediate product accord-ing to Example 1 and is gelled at 180C. The sheet-like structure thus obtained is suitable for the production of coatings of good surface slip.

However, the sheet-like structures can also be bonded -immediately after gelling or else if appropriate after cooling and reheating, in a separate process step - to a PVC film or sheet at 180C under a pressure of 1 bar in a press.

Example 3 (one-stage process) A sheet-like structure is produced from the PTFE sheet, the film and the glass silk fabric in accordance with Example 1, but is compression molded without cooling at about 350C under a pressure of 115 bar with a 100 ~m thick film of a completely aromatic copolyester (~VECTRA
C 950, melting temperature 320 to 325C, commercial product of Hoechst AG).

Claims (10)

1. A composite body comprising layers, one on top of the other, of a) polytetrafluoroethylene (PTFE), b) a copolymer which has predominantly tetrafluoro-ethylene units and acts as a hot-melt adhesive with respect to the PTFE, c) a fiber material which is stable up to at least 400°C and d) at least one plastic which can be processed as a melt.
2. The shaped article as claimed in claim 1, in which the PTFE is present in the form of a film or sheet.
3. The shaped article as claimed in claim 1 or 2, wherein the copolymer contains units of a perfluoro-alkyl perfluorovinyl ether or of a perfluoroalkene.
4. The shaped article as claimed in one or more of the preceding claims, in which the fiber material com-prises fibers of glass, ceramic, carbon, metal or plastic.
5. The shaped article as claimed in one or more of the preceding claims, in which the plastic which can be processed as a melt is poly(vinyl chloride), poly-ethylene, polypropylene or a liquid-crystal polymer.
6. An intermediate product for the production of a shaped article as claimed in claims 1 to 5, which has layers a) to c), one on top of the other, as claimed in claim 1.
7. A process for the production of the intermediate product as claimed in claim 6, which comprises pressing together layers, one on top of the other, of a) PTFE, b) a copolymer which has predominantly tetrafluoro-ethylene units and acts as a hot-melt adhesive with respect to the PTFE and c) a fiber material which is stable up to at least 400°C
at a temperature from about 350 to about 400°C.
8. A process for the production of a shaped article as claimed in claims 1 to 5, which comprises compres-sion molding an intermediate product as claimed in claim 7 with a layer of at least one plastic which can be processed as a melt, while heating.
9. The use of a shaped article as claimed in claims 1 to 5 for the production of surfaces which have good surface slip.
10. The use of a shaped article as claimed in claims 1 to 5 as a sliding bearing material.
CA002158805A 1994-10-15 1995-09-21 Composites of polytetrafluoroethylene, intermediate products for these and processes for their production Abandoned CA2158805A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4437004A DE4437004A1 (en) 1994-10-15 1994-10-15 Composite bodies made of polytetrafluoroethylene, intermediates therefor and processes for their production
DEP4437004.0 1994-10-15

Publications (1)

Publication Number Publication Date
CA2158805A1 true CA2158805A1 (en) 1996-04-16

Family

ID=6530941

Family Applications (1)

Application Number Title Priority Date Filing Date
CA002158805A Abandoned CA2158805A1 (en) 1994-10-15 1995-09-21 Composites of polytetrafluoroethylene, intermediate products for these and processes for their production

Country Status (5)

Country Link
EP (1) EP0711657A3 (en)
JP (1) JPH08183140A (en)
KR (1) KR960013651A (en)
CA (1) CA2158805A1 (en)
DE (1) DE4437004A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6994908B1 (en) 1998-08-18 2006-02-07 Daikin Industries, Ltd. Polytetrafluoroethylene laminated article

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DK172445B1 (en) 1997-08-06 1998-08-10 Ke Burgmann As A method of making a composite material comprising at least one layer of reinforcing tissue material and at least one
DE20102380U1 (en) * 2001-02-10 2001-05-23 Michel Wolfgang Air cushion composite body made of polytetrafluoroethylene
DE102005030047A1 (en) * 2005-06-27 2007-01-11 Eurocopter Deutschland Gmbh Fiber reinforced, plastic sliding bearing preform manufacture involves compressing fiber reinforced preform while moving preform along its own plane to produce rubbing and /or sliding effect on material surface
JP2021137963A (en) * 2018-05-22 2021-09-16 住友電工ファインポリマー株式会社 Slide member and method for producing slide member
CN113147137A (en) * 2021-05-13 2021-07-23 日氟荣高分子材料(上海)有限公司 Multifunctional composite material and preparation method thereof

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2833686A (en) 1955-06-20 1958-05-06 Du Pont Bonding polytetrafluoroethylene resins
US3607594A (en) * 1967-05-16 1971-09-21 Adaptation Ind Et Commerciales Process for making a self-lubricating material and products obtained thereby
US3480547A (en) * 1967-07-07 1969-11-25 Du Pont Low-friction packing or bearing material
DE2140917A1 (en) * 1971-08-16 1973-03-01 Freudenberg Carl Fa Low friction bearings - using a backed ptfe fleece to cover the bearing surface
DE2311096C3 (en) 1973-03-06 1981-08-20 Hoechst Ag, 6000 Frankfurt Process for connecting molded articles containing polytetrafluoroethylene
DE2840356A1 (en) * 1978-09-16 1980-04-03 Hoechst Ag AQUEOUS DISPERSION OF FLUORINE POLYMERS WITH IMPROVED COATING PROPERTIES
DE3018974A1 (en) * 1980-05-17 1981-11-26 Karl Schmidt Gmbh, 7107 Neckarsulm SLIDING BEARING MATERIAL
US4610918A (en) * 1984-04-13 1986-09-09 Chemical Fabrics Corporation Novel wear resistant fluoropolymer-containing flexible composites
DE3446119C1 (en) * 1984-12-18 1986-05-07 Norton Pampus GmbH, 4156 Willich Process for producing a material for plastics parts, made of polytetrafluoroethylene, having high load-bearing capacity
JP2578705B2 (en) * 1992-03-30 1997-02-05 東海ゴム工業株式会社 Resin tube for fuel pipe and method of manufacturing the same
EP1120594A3 (en) * 1992-04-14 2003-03-05 Itt Manufacturing Enterprises, Inc. Multi-layer fuel and vapor tube
US5320888A (en) * 1993-11-12 1994-06-14 E. I. Du Pont De Nemours And Company Fluoroelastomer laminates

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6994908B1 (en) 1998-08-18 2006-02-07 Daikin Industries, Ltd. Polytetrafluoroethylene laminated article
US7244503B2 (en) 1998-08-18 2007-07-17 Daikin Industries, Ltd. Polytetrafluoroethylene laminated article

Also Published As

Publication number Publication date
EP0711657A3 (en) 1996-09-11
EP0711657A2 (en) 1996-05-15
JPH08183140A (en) 1996-07-16
KR960013651A (en) 1996-05-22
DE4437004A1 (en) 1996-04-18

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