United States Patent [19]
`United States Patent [191
`Swei et al.
`Swei et al.
`
`1111111111111111111111111111,11!lollolf,R11111111111111111111111111111
`Hlllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllll
`US005506049A
`5,506,049
`5,506,049
`[11] (cid:9) Patent Number:
`[11] Patent Number:
`[45] (cid:9) Date of Patent:
`* Apr. 9, 1996
`* Apr. 9, 1996
`[45] Date of Patent:
`
`[54] PARTICULATE FILLED COMPOSITE FILM
`[54] PART ICULATE FILLED COMPOSITE FILM
`AND METHOD OF MAKING SAME
`AND METHOD OF MAKING SAME
`
`[75] Inventors: Gwo S. Swei, Northboro; David J.
`[75] Inventors: Gwo S. Swei, Northboro; David J.
`Arthur, Norwood, both of Mass.
`Arthur, Norwood, both of Mass.
`
`[73] Assignee: Rogers Corporation, Rogers, Conn.
`[73] Assignee: Rogers Corporation, Rogers, Conn.
`
`[ * ] Notice: (cid:9)
`[*] Notice:
`
`The portion of the term of this patent
`The portion of the term of this patent
`subsequent to Jun. 18, 2008, has been
`subsequent to Jun. 18, 2008, has been
`disclaimed.
`disclaimed.
`
`[21] Appl. No.: 177,198
`[21] Appl. No.: 177,198
`Dec. 30, 1993
`[22] Filed: (cid:9)
`Dec. 30, 1993
`[22] Filed:
`
`Related U.S. Application Data
`Related U.S. Application Data
`
`[62] Division of Ser. No. 705,624, May 24, 1991, abandoned.
`[62] Division of Ser. No. 705,624, May 24, 1991, abandoned.
`[51] Int. C1.6
` B32B 5/16
`[51] Int. Cl.6 ...................................................... .. B32B 5/16
`[52] U.S. Cl. (cid:9)
` 428/323; 428/325; 428/335;
`[52] U.S. Cl. ........................ .. 428/323; 428/325; 428/335;
`428/901
`428/901
`[58] Field of Search (cid:9)
` 428/323, 325,
`[58] Field of Search ................................... .. 428/323, 325,
`428/335, 403, 404, 405, 406, 407, 421,
`428/335, 403, 404, 405, 406, 407, 421,
`422, 457, 901
`422, 457, 901
`
`[56]
`[56]
`
`References Cited
`References Cited
`
`U.S. PATENT DOCUMENTS
`U.S. PATENT DOCUMENTS
`
`5/1980 Grandine, II (cid:9)
`
`310/490
`4,203,848
`5/1980 Grandine, ll ......................... .. 310/490
`4,203,848
`7/1980 Reed (cid:9)
`
`428/901 X
`4,211,603
`7/1980 Reed ................................. .. 428/901 X
`4,211,603
`4,307,142 12/1981 Blitstein et al. (cid:9)
`
`428/143
`4,307,142 12/1981 Blitstein et a1. .
`428/143
`4,380,521
`4/1983 Moreno et al. (cid:9)
`
`264/49
`4,380,521
`4/1983 Moreno et a1. ..
`264/49
`4,393,119
`7/1983 Concannon (cid:9)
`
`428/413
`4,393,119
`7/1983 Concannon ........................... .. 428/413
`4,409,354 10/1983 Namba et al. (cid:9)
`
`524/431
`4,409,354 10/1983 Narnba etal. ........................ .. 524/431
`4,434,116
`2/1984 Covitch (cid:9)
`
`264/49
`4,434,116
`2/1984 Covitch ...... ..
`264/49
`4,500,603
`2/1985 Freundlich (cid:9)
`
`428/409
`4,500,603
`2/1985 Freundlich ........ ..
`428/409
`4,555,543 11/1985 Effenberger etal.
`428/421
`4,555,543 11/1985 Effenberger et al. (cid:9)
` 428/421
`4,610,918
`9/1986 Effenberger et al. (cid:9)
` 428/245
`4,610,918
`9/1986 Effenberger et a1v
`428/245
`264/41
`4,692,287
`9/1987 Timmons (cid:9)
`
`4,692,287
`9/ 1987
`264/41
`4,818,619
`4/1989 Stepparola et al. (cid:9)
` 428/421
`4,818,619
`4/1989
`428/421
`4,824,511
`4/1989 Hartman et al. (cid:9)
`
`428/209 X
`4,824,511
`4/1989
`428/209 X
`4,847,135
`7/1989 Braus et al. (cid:9)
`
`428/138
`4,847,135
`7/1989
`428/138
`4,849,284
`7/1989 Arthur et al. (cid:9)
`
`428/325
`4,849,284
`7/1989
`428/325
`4,883,716 11/1989 Effenberger et al. (cid:9)
` 428/421
`4,883,716 11/1989 Eifenberger et al.
`428/421
`4,888,245 12/1989 Nitzko (cid:9)
`
`428/421
`4,888,245 12/1989 Nitzko ................................... .. 428/421
`
`(List continued on next page.)
`(List continued on next page.)
`
`FOREIGN PAI (cid:9) ENT DOCUMENTS
`FOREIGN PATENT DOCUMENTS
`
`246844 11/1987 European Pat. Off. .
`246844 ll/l987 European Pat. Off. .
`2071112 9/1981 United Kingdom .
`2071112 9/1981 United Kingdom .
`
`Primary Examiner—-Paul .l. Thibodeau
`Primary Examiner—Paul J. Thibodeau
`Assistant Examiner—H. Thi Le
`Assistant Examiner-H. Thi Le
`Attorney, Agent, or Firm—Fishman, Dionne & Cantor
`Attorney, Agent, or Firm—Fishman, Dionne & Cantor
`
`ABSTRACT
`[57]
`ABSTRACT
`[57] (cid:9)
`A particulate ?lled ?uoropolymeric matrix composite article
`A particulate filled fluoropolymeric matrix composite article
`and method of making the same is presented. Preferably, the
`and method of making the same is presented. Preferably, the
`article comprises an electrical substrate material. The
`article comprises an electrical substrate material. The
`method for making the particulate ?lled polymeric matrix
`method for making the particulate filled polymeric matrix
`composite film includes mixing a polymeric matrix material
`composite ?lm includes mixing a polymeric matrix material
`with a dispersion of particulate filler in a carrier liquid to
`with a dispersion of particulate ?ller in a carrier liquid to
`form a casting composition and adjusting the viscosity of the
`form a casting composition and adjusting the viscosity of the
`casting composition to retard separation of the particulate
`casting composition to retard separation of the particulate
`?ller from the composition. A layer of the viscosity-adjusted
`filler from the composition. A layer of the viscosity-adjusted
`casting composition is cast on a substrate and the layer is
`casting composition is cast on a substrate and the layer is
`consolidated to form the particulate filled polymer matrix
`consolidated to form the particulate ?lled polymer matrix
`composite film. Films made by the method include very thin,
`composite ?lm, Films made by the method include very thin,
`e.g less than 1.0 mil, fluoropolymeric matrix films highly
`e.g less than 1.0 mil, ?uoropolymeric matrix ?lms highly
`filled with very small diameter, preferably spherical, par-
`?lled with very small diameter, preferably spherical, par
`ticles for use as, e.g. dielectric substrate materials in laminar
`ticles for use as, e. g. dielectric substrate materials in larrrinar
`electrical circuits.
`electrical circuits.
`
`40 Claims, 1 Drawing Sheet
`40 Claims, 1 Drawing Sheet
`
`,2
`4
`
`6/1955 Hochberg (cid:9)
`2,710,266
`
`428/268
`6/1955 Hochberg .............................. .. 428/268
`2,710,266
`9/1958 Petriello (cid:9)
`
`264/39
`2,852,811
`9/1958 Petriello
`.... .. 264/39
`2,852,811
`2/1960 Petriello (cid:9)
`
`428/461
`2,923,651
`2/1960 Petxiello
`428/461
`2,923,651
`2,945,831
`7/1960 Evans et al. (cid:9)
`
`260/29.6
`7/1960 Evans et al.
`.. 260/296
`2,945,831
`2,961,345 11/1960 Petriello (cid:9)
`
`428/212
`2,961,345 1l/l960 Petriello ...... ..
`428/212
`2,980,965
`4/1961 Infantino et al. (cid:9)
`
`18/57
`2,980,965
`4/1961 Infantino et a1. .
`...... .. 18/57
`3,054,716
`9/1962 Bergstein et al. (cid:9)
`
`264/212
`3,054,716
`9/1962 Bergstein et al.
`264/212
`3,054,761
`9/1962 Moore et al. (cid:9)
`
`524/491
`3,054,761
`9/1962 Moore et a1.
`524/491
`3,292,725 11/1966 Van Mingo (cid:9)
`
`264/215
`3,292,725 11/1966 Van Zalingo .
`264/215
`3,518,332
`6/1970 Skiarchuk (cid:9)
`
`264/49
`3,518,332
`6/1970 Skiarchuk
`.... .. 264/49
`3,556,161
`8/1970 Roberts (cid:9)
`
`138/141
`3,556,161
`8/1970 Roberts ...... ..
`138/141
`3,577,508
`5/1971 Desaulniers (cid:9)
`
`264/331.15
`3,577,508
`5/1971 Desaulniers ..
`264/33l.l5
`3,679,614
`7/1972 Shah et al. (cid:9)
`
`521/62
`3,679,614 7/1972 Shah et a1. .............................. .. 521/62
`3,843,570 10/1974 Murayama (cid:9)
`
`521/62
`3,843,570 10/1974 Murayama .............................. .. 521/62
`4,049,589
`9/1977 Sakane (cid:9)
`
`521/64
`4,112,037
`9/1978 Parker et al. (cid:9)
`
`264/126
`4,112,037
`9/1978 Parker et a1. .
`264/126
`4,183,991
`1/1980 Smiley et al. (cid:9)
`
`428/220
`4,183,991
`1/1980 Smiley et a1.
`428/220
`4,196,070
`4/1980 Chao et al. (cid:9)
`
`204/226
`4,196,070
`4/1980 Chao et a1. ........................... .. 204/226
`
`4,049,589
`
`9/1977 Sakane . . . . . . . . .
`
`. . . _ .. 521/64
`
`Par Pharm., Inc., et al.
`Exhibit 1018
`Page 001
`
`(cid:9)
`(cid:9)
`

`

`5,506,049
`5,506,049
`Page 2
`Page 2
`
`U.S. PA1ENT DOCUMENTS
`US. PATENT DOCUMENTS
`
`4,895,756
`
`1/1990 (cid:9) Suzuki (cid:9)
`428/317.9
`1/1990 Suzuki ............................... .. 428/317.9
`4,895,756
`4/1990 (cid:9) Lake et al. (cid:9)
`4,915,983
`
`430/311 X
`4,915,983 4/1990 Lake et a1. .......... ..
`430/311 X
`4,985,296
`1/1991 (cid:9) Mortimer, Jr. (cid:9)
`
`428/220
`4,985,296
`1/1991 Mortimer, Jr. ........................ .. 428/220
`
`2/1991 Asaumi et al. (cid:9)
`4,990,544
`
`428/283 X
`2/1991 Asaumi et a1. ................... .. 428/283 X
`4,990,544
`6/1991 Arthur et al. (cid:9)
`5,024,871
`
`428/209
`6/1991 Arthur et a1.
`.... .. 428/209
`5,024,871
`5,061,548 10/1991 Arthur et al. (cid:9)
`
`428/209
`5,061,543 10/1991 Arthur et a1_ _________________________ ,_ 423/209
`5,077,115 12/1991 Arthur et al. (cid:9)
`
`428/137
`5,077,115 12/1991 Arthur at :11V ......................... .. 428/137
`5,198,295
`3/1993 Arthur et at (cid:9)
`
`428/323
`5,198,295
`3/1993 Anhur et a1. ......................... .. 428/323
`
`Par Pharm., Inc., et al.
`Exhibit 1018
`Page 002
`
`

`

`U.S. Patent (cid:9)
`US. Patent
`
`Apr. 9, 1996
`Apr. 9, 1996
`
`5,506,049
`5,506,049
`
`FIG. /
`
`F G. 2
`
`F G
`
`F G. 4
`
`FI G. 5
`
`Par Pharm., Inc., et al.
`Exhibit 1018
`Page 003
`
`(cid:9)
`

`

`5 ,506,049
`5,506,049
`
`1
`1
`PARTICULATE FILLED COMPOSITE FILM
`PARTICULATE FILLED COMPOSITE FILM
`AND METHOD OF MAKING SAME
`AND METHOD OF MAKING SAME
`
`This is a divisional of application Ser. No. 07/705,624
`This is a divisional of application Ser. No. 07/705,624
`filed on May 24, 1991, now abandoned. (cid:9)
`?led on May 24, 1991, now abandoned.
`
`5
`
`2
`2
`di?icult and economically extremely difficult to produce
`difficult and economically extremely difficult to produce
`thin, i.e. less than 2 mils, highly filled, i.e. greater than about
`thin, i.e. less than 2 mils, highly ?lled, i.e. greater than about
`40%, ?uoropolymer matrix composite ?lms by the paste
`40%, fluoropolymer matrix composite films by the paste
`extrusion and calendering process.
`extrusion and calendering process.
`What is needed in the art is a method which overcomes
`What is needed in the art is a method which overcomes
`the above noted deficiencies of known processing methods.
`the above noted de?ciencies of known processing methods.
`
`TECHNICAL FIELD
`TECHNICAL FIELD
`
`The present invention relates to particulate ?lled polymer
`The present invention relates to particulate filled polymer
`matrix composite materials and methods of manufacturing
`matrix composite materials and methods of manufacturing
`same and more particularly to thin films of highly filled
`same and more particularly to thin ?lms of highly ?lled
`polymer matrix composite materials.
`polymer matrix composite materials.
`
`BACKGROUND OF THE INVENTION
`BACKGROUND OF THE INVENTION
`
`10 (cid:9)
`
`SUMMARY OF THE INVENTION
`SUMMARY OF THE INVENTION
`A particulate ?lled ?uoropolymer matrix composite
`A particulate filled fluoropolymer matrix composite
`article is disclosed. The article includes a fluoropolymer
`article is disclosed. The article includes a ?uoropolymer
`matrix and up to about 95 vol. % filler particles distributed
`matrix and up to about 95 vol. % ?ller particles distributed
`throughout the matrix, wherein said particles have a maxi-
`throughout the matrix, wherein said particles have a maxi
`mum equivalent spherical diameter of less than about 10
`mum equivalent spherical diameter of less than about 10
`15 microns.
`microns.
`15
`In an alternative embodiment, a particulate filled fluo-
`In an alternative embodiment, a particulate ?lled ?uo
`ropolymer matrix composite article comprises a ?uoropoly
`ropolymer matrix composite article comprises a fluoropoly-
`mer matrix and up to about 95 vol. % filler particles
`mer matrix and up to about 95 vol. % ?ller particles
`distributed throughout the matrix wherein none of the par-
`distributed throughout the matrix wherein none of the par
`tides have a single linear dimension greater than about 10
`ticles have a single linear dimension greater than about 10
`microns.
`microns.
`In a preferred embodiment a particulate filled fluoropoly-
`In a preferred embodiment a particulate ?lled ?uoropoly—
`mer matrix composite film comprises a nonfibrillated fluo-
`mer matrix composite ?lm comprises a non?brillated ?uo
`ropolymer matrix and greater than about 15 vol. percent
`ropolymer matrix and greater than about 15 vol. percent
`25 filler particles distributed throughout the matrix. The film
`25
`?ller particles distributed throughout the matrix. The ?lm
`has a thickness less than about 2 mils and is free of visually
`has a thickness less than about 2 mils and is free of visually
`evident pin holes or tears.
`evident pin holes or tears.
`A porous fluoropolymer film comprising a nonfibrillated
`A porous ?uoropolymer ?lm comprising a non?brillated
`fluoropolymer matrix having a void volume of greater than
`?uoropolymer matrix having a void volume of greater than
`about 15 vol. % and a thickness of less than about 2 mils is
`about 15 vol. % and a thickness of less than about 2 mils is
`disclosed.
`disclosed.
`A method for making a particulate filled polymer matrix
`A method for making a particulate ?lled polymer matrix
`composite ?lm is disclosed. The method comprises mixing
`composite film is disclosed. The method comprises mixing
`the polymer with a dispersion of the particulate filler in a
`the polymer with a dispersion of the particulate ?ller in a
`carrier liquid to provide a casting composition, wherein the
`carrier liquid to provide a casting composition, wherein the
`casting composition includes relative amounts of polymer
`casting composition includes relative amounts of polymer
`and filler effective to provide a film having greater than 15
`and ?ller e?cective to provide a ?lm having greater than 15
`volume percent filler casting a layer of the casting compo-
`volume percent ?ller casting a layer of the casting compo
`sition onto a substrate and consolidating the cast layer to
`sition onto a substrate and consolidating the cast layer to
`form the particulate ?lled polymer matrix composite ?lm.
`form the particulate filled polymer matrix composite film.
`A casting composition is also disclosed. The casting
`A casting composition is also disclosed. The casting
`composition includes a mixture of liquid carrier, a polymeric
`composition includes a mixture of liquid carrier, a polymeric
`matrix material, and particles of a filler material.
`matrix material, and particles of a ?ller material.
`
`20
`
`35
`35
`
`40
`
`Laminated electrical circuit substrates which include a
`Laminated electrical circuit substrates which include a
`conductive layer supported on a dielectric ?uoropolymer
`conductive layer supported on a dielectric fluoropolymer
`matrix composite layer are known. Driven by the continuing
`matrix composite layer are known. Driven by the continuing
`trend toward increasing circuit density, very thin ?lms, e.g.
`trend toward increasing circuit density, very thin films, e.g.
`less than about 1.0 mil, of highly ?lled ?uoropolymeric
`less than about 1.0 mil, of highly filled fluoropolymeric
`matrix composite substrate materials having a substantially
`matrix composite substrate materials having a substantially
`uniform microstructure have become desirable as allowing
`uniform microstructure have become desirable as allowing
`further reduction in the size of electronic circuits. It is
`further reduction in the size of electronic circuits. It is
`technically and economically difficult to make such mate-
`technically and economically di?icult to make such mate
`rials by known methods.
`rials by known methods.
`Fluoropolymer and particulate ?lled ?uoropolymer
`Fluoropolymer and particulate filled fluoropolymer
`matrix composite ?lms are made by known papermaking,
`matrix composite films are made by known papermaking,
`skiving, casting, melt extrusion and paste extrusion and
`skiving, casting, melt extrusion and paste extrusion and
`calendering processes.
`calendering processes.
`Films produced by paper making processes required ?ber
`Films produced by paper making processes required fiber 30
`reinforcement and are limited to thicknesses greater than
`reinforcement and are limited to thicknesses greater than
`about 2 mil.
`about 2 mil.
`It is very di?icult to produce thin high quality highly ?lled
`It is very difficult to produce thin high quality highly filled
`?uoropolymer matrix ?lms by skiving due to abrasion of the
`fluoropolymer matrix films by skiving due to abrasion of the
`skiving blade by the ?ller particles and tearing of the ?lm
`skiving blade by the filler particles and tearing of the film
`associated with the resistance of the filler particles to the
`associated with the resistance of the ?ller particles to the
`skiving blade.
`skiving blade.
`The ?ller loading of ?lms made by known casting pro_
`The filler loading of films made by known casting pro-
`cesses is limited to less than about 15 volume percent.
`cesses is limited to less than about 15 volume percent.
`The high melt viscosity of neat ?uoropolymers compli
`The high melt viscosity of neat fluoropolymers compli-
`cates the production of fluoropolymer films by melt extru-
`cates the production of ?uoropolymer ?lms by melt extru
`sion. Polyvinylidene ?uoride (PVFQ) and polychlorotri?uo
`sion. Polyvinylidene fluoride (PVF2) and polychlorotrifluo-
`roethylene (PC 11-,h) are melt extrudable only within a
`roethylene (PCTFE) are melt extrudable only within a
`narrow processing window. Polyvinylfluoride (PVF) film
`narrow processing window. Polyvinyl?uoride (PVF) ?lm
`cannot be produced by melt extrusion due to thermal insta-
`cannot be produced by melt extrusion due to thermal insta
`bility. Polytetrafluoroethylene (PTFE) cannot be melt
`bility. Polytetra?uoroethylene (PTFE) cannot be melt
`extruded due to its extraordinarily high melt viscosity.
`extruded due to its extraordinarily high melt viscosity.
`Fluorocopolymers are known which provide lower melting
`Fluorocopolymers are known which provide lower melting
`temperature and lower melt viscosity at extrusion tempera-
`temperature and lower melt viscosity at extrusion tempera
`tures, e.g. copolymers of tetrafluoroethylene with hexafluo-
`tures, e. g. copolymers of tetra?uoroethylene with hexa?uo
`ropropylene (FEP) or with ethylene, copolymers of C [Pb
`ropropylene (FEP) or with ethylene, copolymers of CTFE
`with vinylidene fluoride or hexafluoropropylene.
`with vinylidene ?uoride or hexa?uoropropylene.
`The introduction of fillers further complicates the melt
`The introduction of ?llers further complicates the melt
`extrusion of fluoropolymers. In the presence of certain
`extrusion of ?uoropolymers. In the presence of certain
`fillers, especially at high filler loading level, the melt pro-
`?llers, especially at high ?ller loading level, the melt pro
`cessability of the melt extrudable ?uoropolymers is rapidly
`cessability of the melt extrudable fluoropolymers is rapidly
`degraded due to the increase in melt viscosity associated
`degraded due to the increase in melt viscosity associated
`with the presence of the filler or with filler-catalyzed thermal
`with the presence of the ?ller or with ?ller—catalyzed thermal
`degradation of the polymer matrix.
`degradation of the polymer matrix.
`A method of making highly filled PTFE composite mate-
`A method of making highly ?lled PI‘FE composite mate
`rials which exhibit excellent physical and electrical proper-
`rials which exhibit excellent physical and electrical proper
`ties by paste extrusion and calendering is set forth in
`ties by paste extrusion and calendering is set forth in
`coassigned U.S. Pat. No. 4,849,284 to D. J. Arthur, J. C.
`coassigned US. Pat. No. 4,849,284 to D. J. Arthur, .I. C.
`Mosko, C. S. Jackson and G. R. Traut, entitled "ELECTRI-
`Mosko, C. S. Jackson and G. R. Traut, entitled “ELECTRI
`CAL SUBSTRATE MATERIAL", the disclosure of which is
`CAL SUBSTRATE MATERIAL”, the disclosure of which is
`incorporated herein by reference. However, it is technically
`incorporated herein by reference. However, it is technically
`
`45
`45
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`50
`
`FIG. 1 shows a photomicrograph of a cross sectional view
`FIG. 1 shows a photomicrograph of a cross sectional view
`of a particulate filled polymer matrix composite film of the
`of a particulate ?lled polymer matrix composite ?lm of the
`present invention.
`present invention.
`FIG. 2 shows a laminar circuit substrate made by the
`FIG. 2 shows a laminar circuit substrate made by the
`process of the present invention.
`process of the present invention.
`FIG. 3 shows a cross sectional view of a conductive
`FIG. 3 shows a cross sectional view of a conductive
`through~hole communicating between layers of a portion of
`through-hole communicating between layers of a portion of
`55 a laminated electrical circuit.
`a laminated electrical circuit.
`55
`FIG. 4 shows a cross sectional view taken along lines 4-
`FIG. 4 shows a cross sectional view taken along lines 4
`4 of FIG. 3.
`4 of FIG. 3.
`FIG. 5 shows a cross sectional view of a portion of a
`FIG. 5 shows a cross sectional view of a portion of a
`laminar electrical circuit.
`laminar electrical circuit.
`
`60
`
`DETAILED DESCRIPTION OF THE
`DETAILED DESCRIPTION OF THE
`INVENTION
`INVENTION
`
`Suitable fluoropolymer matrix materials include fluori-
`Suitable ?uoropolymer matrix materials include ?uori
`nated homopolymers, e.g. polytetra?uoroethylene (PTFE)
`65 nated homopolymers, e.g. polytetrafluoroethylene (PTFE)
`65
`and polychlorotri?uoroethylene (PCTFE) and ?uorinated
`and polychiorotrifluoroethylene (PC11-h) and fluorinated
`copolymers, e.g. copolymers of tetrafluoroethylene with a
`copolymers, e.g. copolymers of tetra?uoroethylene with a
`
`Par Pharm., Inc., et al.
`Exhibit 1018
`Page 004
`
`

`

`5,506,049
`5,506,049
`
`3
`3
`monomer selected from the group consisting of hexafluo-
`monomer selected from the group consisting of hexa?uo
`ropropylene and per?uoroalkylvinylethers, copolymers of
`ropropylene and perfluoroalkylvinylethers, copolymers of
`tetrafluoroethylene with a monomer selected from the group
`tetra?uoroethylene with a monomer selected from the group
`consisting of vinylidene ?uoride, vinyl ?uoride and ethyl
`consisting of vinylidene fluoride, vinyl fluoride and ethyl-
`ene, and copolymers of chlorotrifluoroethylene with a 5
`ene, and copolymers of chlorotri?uoroethylene with a
`monomer selected from the group of hexafluoropropylene,
`monomer selected from the group of hexa?uoropropylene, >
`per?uoroalkylvinylethers, vinylidene ?uoride, vinyl ?uoride
`perfluoroalkylvinylethers, vinylidene fluoride, vinyl fluoride
`and ethylene. Blends of the above listed ?uoropolymers and
`and ethylene. Blends of the above listed fluoropolymers and
`terpolymers formed from the above listed monomers are
`terpolymers formed from the above listed monomers are
`also suitable as the fluoropolymer matrix material of the 10
`also suitable as the ?uoropolymer matrix material of the
`10
`present invention.
`present invention.
`Alternatively, polymer matrix material of the present
`Alternatively, polymer matrix material of the present
`invention may comprise a thermoplastic or thermosetting
`invention may comprise a thermoplastic or thermosetting
`polymer other than a fluoropolymer. Suitable alternative
`polymer other than a ?uoropolymer. Suitable alternative
`polymeric matrix materials include, e.g. polyole?ns, poly
`polymeric matrix materials include, e.g. polyolefins, poly- 15
`irnides, epoxy resins and cyanate esters. Speci?c examples
`imides, epoxy resins and cyanate esters. Specific examples
`of suitable polymer matrix materials include polyethylene,
`of suitable polymer matrix materials include polyethylene,
`polymethylpentene, and polybutadiene.
`polymethylpentene, and polybutadiene.
`The particulate filler material of the present invention may
`The particulate ?ller material of the present invention may
`include any organic or inorganic particulate material. The
`include any organic or inorganic particulate material. The 20
`20
`terms "particulate" and "particles" as used herein are
`terms “particulate” and “particles” as used herein are
`intended to include fibers. Suitable inorganic filler materials
`intended to include ?bers. Suitable inorganic ?ller materials
`include, e.g. glass particles, ceramic particles, metallic par
`include, e.g. glass particles, ceramic particles, metallic par-
`ticles, carbon particles and mineral particles. Speci?c
`ticles, carbon particles and mineral particles. Specific
`examples of suitable particles include glass beads, glass
`examples of suitable particles include glass beads, glass 25
`microspheres, glass ?bers, silica particles, carbon black,
`microspheres, glass fibers, silica particles, carbon black,
`titanium dioxide particles and barium titanate particles.
`titanium dioxide particles and barium titanate particles.
`Silica particles, particularly amorphous fused silica particles
`Silica particles, particularly amorphous fused silica particles
`and silica particles made by a sol gel process, and glass
`and silica particles made by a sol gel process, and glass
`particles, are preferred ?ller particles for applications, e.g.
`particles, are preferred filler particles for applications, e.g. 30
`30
`dielectric layers of laminar electrical circuits, requiring a
`dielectric layers of laminar electrical circuits, requiring a
`low dielectric constant.
`low dielectric constant.
`Speci?c examples of suitable polymeric particulate ?llers
`Specific examples of suitable polymeric particulate fillers
`include polymethylmethacrylate particles, polystyrene par
`include polymethylmethacrylate particles, polystyrene par-
`ticles and polyimide particles. Suitable polymeric particles,
`ticles and polyimide particles. Suitable polymeric particles, 35
`e.g. LARC-TPl (Rogers, Corp.), P-84 (Lenzing).
`e.g. LARC-TP1 (Rogers, Corp.), P-84 (Lenzing).
`The shape of the filler particles, the size of the filler
`The shape of the ?ller particles, the size of the ?ller
`particles and the size distribution of the filler particles are
`particles and the size distribution of the ?ller particles are
`important parameters with regard to characterizing the par
`important parameters with regard to characterizing the par-
`ticle filled composite article of the present invention. (cid:9)
`ticle ?lled composite article of the present invention.
`In a preferred embodiment of the present invention all
`In a preferred embodiment of the present invention all
`particles of the particulate ?ller exhibit an equivalent spheri
`particles of the particulate filler exhibit an equivalent spheri-
`cal diameter of less than about 10 microns (um). As used
`cal diameter of less than about 10 microns (um). As used
`herein the "equivalent spherical diameter" of a filler particle
`herein the “equivalent spherical diameter” of a ?ller particle
`is the diameter of a sphere which occupies the same volume 45
`45
`is the diameter of a sphere which occupies the same volume
`as that occupied by the ?ller particle.
`as that occupied by the filler particle.
`In an alternative preferred embodiment of the present
`In an alternative preferred embodiment of the present
`invention, each of the filler particles exhibit no single linear
`invention, each of the ?ller particles exhibit no single linear
`dimension greater than about 10 um.
`dimension greater than about 10 um.
`For extremely thin films and in applications where a
`For extremely thin ?lms and in applications where a
`substantially uniform microstructure is an important char-
`substantially unifonn microstrncture is an important char
`acteristic of the film, it is preferred that all particles of the
`acteristic of the ?lm, it is preferred that all particles of the
`particulate filler exhibit an equivalent spherical diameter of
`particulate ?ller exhibit an equivalent spherical diameter of
`less than about 5 um. Alternatively, it is preferred that all 55
`less than about 5 um. Alternatively, it is preferred that all
`55
`particles of the particulate ?ller exhibit no single linear
`particles of the particulate filler exhibit no single linear
`dimension greater than about 5 gm.
`dimension greater than about 5 um.
`In a preferred embodiment of the present invention each
`In a preferred embodiment of the present invention each
`of the filler particles is substantially spherical. The use of
`of the ?ller particles is substantially spherical. The use of
`spherical ?ller particles provides improved processability by
`spherical filler particles provides improved processability by 60
`minimizing the filler surface area for a given particle size
`minimizing the ?ller surface area for a given particle size
`and ?ller loading. Furthermore, spherical particles provide
`and filler loading. Furthermore, spherical particles provide
`isotropic properties to the ?lm since the spherical particles
`isotropic properties to the film since the spherical particles
`do not become oriented during processing.
`do not become oriented during processing.
`In a preferred embodiment of the present invention, the 65
`In a preferred embodiment of the present invention, the
`65
`filler particles of the film are of a uniform size. The use of
`?ller particles of the ?lm are of a uniform size. The use of
`a monodisperse filler, i.e. wherein all the filler particles are
`a monodisperse ?ller, i.e. wherein all the ?ller particles are
`
`50
`50
`
`40
`
`4
`4
`of substantially the same size, provides a more homoge-
`of substantially the same size, provides a more homoge
`neous ?lm having substantially uniform properties through
`neous film having substantially uniform properties through-
`out.
`out.
`In a particularly preferred embodiment of the present
`In a particularly preferred embodiment of the present
`invention, the ?ller particles comprise spherical silica par
`invention, the filler particles comprise spherical silica par-
`ticles of a substantially uniform size, i.e. all particles within
`ticles of a substantially unifonn size, i.e. all particles within
`plus or minus 10% of a nominal particle diameter. A pure
`plus or minus 10% of a nominal particle diameter. A pure
`silica powder known as GELSIL® produced by Geltech,
`silica powder known as GELSIL® produced by Geltech,
`Inc. and speci?ed as :1 micron sphere size (i10%); density
`Inc. and specified as :1 micron sphere size (±10%); density
`of 2.2 gramslcmz; free of hard agglomerations, has been
`of 2.2 grams/cm2; free of hard agglomerations, has been
`found to be particularly suitable for use in the practice of the
`found to be particularly suitable for use in the practice of the
`present invention.
`present invention.
`The particulate filler material may be treated with a
`The particulate ?ller material may be treated with a
`surface treatment to improve the moisture resistance and
`surface treatment to improve the moisture resistance and
`improve the mechanical properties of the composite ?lm of
`improve the mechanical properties of the composite film of
`the present invention.
`the present invention.
`The hydrophobic coating of the present invention may
`The hydrophobic coating of the present invention may
`comprise any coating material that is thermally stable,
`comprise any coating material that is thermally stable,
`exhibits a low surface energy, and improves the moisture
`exhibits a low surface energy, and improves the moisture
`resistance of the composite of the present invention. Suitable
`resistance of the composite of the present invention. Suitable
`coating materials, include conventional silane coatings,
`coating materials, include conventional silane coatings,
`titanate coatings and zirconate coatings. Preferred silane
`titanate coatings and zirconate coatings. Preferred silane
`coatings include: phenyltrimethoxysilane, phenyltriethox
`coatings include: phenyltrimethoxysilane, phenyltriethox-
`ysilane, 3,3,3-trifluoropropyltrimethoxysilane, (tridecaf
`ysilane, 3,3,3-trifluoropropyltrimethoxysilane, (tridecaf-
`luoro- 1,1,2,2-tetrahydrodecyl)-l-triethoxysilane and mix
`luoro- 1,1,2,2-tetrahydrodecyl)-1-triethoxysilane and mix-
`tures thereof. Further examples of suitable fluorinated silane
`tures thereof. Further examples of suitable ?uorinated silane
`compounds are set forth ill coassigned U.S. application Ser.
`compounds are set forth ill coassigned U.S. application Ser.
`No 279,474, filed Dec. 2, 1988 and entitled "FLUO-
`No 279,474, ?led Dec. 2, 1988 and entitled “FLUO
`ROPOLYMER COMPOSITE" by D. J. Arthur and G. S.
`ROPOLYMER COMPOSI ” by D. J. Arthur and G. S.
`Swei, the disclosure of which is incorporated herein by
`Swei, the disclosure of which is incorporated herein by
`refe