Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L61/00—Compositions of condensation polymers of aldehydes or ketones; Compositions of derivatives of such polymers
  • C08L61/20—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen
  • C08L61/26—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen of aldehydes with heterocyclic compounds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
  • C08G59/40—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the curing agents used
  • C08G59/42—Polycarboxylic acids; Anhydrides, halides or low molecular weight esters thereof
  • C08G59/4246—Polycarboxylic acids; Anhydrides, halides or low molecular weight esters thereof polymers with carboxylic terminal groups
  • C08G59/4261—Macromolecular compounds obtained by reactions involving only unsaturated carbon-to-carbon bindings
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
  • C08J5/24—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs
  • C08J5/241—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs using inorganic fibres
  • C08J5/244—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs using inorganic fibres using glass fibres
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
  • C08J5/24—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs
  • C08J5/249—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs characterised by the additives used in the prepolymer mixture
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L35/00—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a carboxyl radical, and containing at least one other carboxyl radical in the molecule, or of salts, anhydrides, esters, amides, imides or nitriles thereof; Compositions of derivatives of such polymers
  • C08L35/06—Copolymers with vinyl aromatic monomers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L63/00—Compositions of epoxy resins; Compositions of derivatives of epoxy resins
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L79/00—Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen with or without oxygen or carbon only, not provided for in groups C08L61/00 - C08L77/00
  • C08L79/04—Polycondensates having nitrogen-containing heterocyclic rings in the main chain; Polyhydrazides; Polyamide acids or similar polyimide precursors
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2363/00—Characterised by the use of epoxy resins; Derivatives of epoxy resins
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2479/00—Characterised by the use of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen with or without oxygen, or carbon only, not provided for in groups C08J2461/00 - C08J2477/00
  • C08J2479/04—Polycondensates having nitrogen-containing heterocyclic rings in the main chain; Polyhydrazides; Polyamide acids or similar polyimide precursors
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2205/00—Polymer mixtures characterised by other features
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L25/00—Compositions of, homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring; Compositions of derivatives of such polymers
  • C08L25/02—Homopolymers or copolymers of hydrocarbons
  • C08L25/04—Homopolymers or copolymers of styrene
  • C08L25/08—Copolymers of styrene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L9/00—Compositions of homopolymers or copolymers of conjugated diene hydrocarbons
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K1/00—Printed circuits
  • H05K1/02—Details
  • H05K1/03—Use of materials for the substrate
  • H05K1/0313—Organic insulating material
  • H05K1/0353—Organic insulating material consisting of two or more materials, e.g. two or more polymers, polymer + filler, + reinforcement
• • Y—GENERAL 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
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/2933—Coated or with bond, impregnation or core
  • Y10T428/2964—Artificial fiber or filament
  • Y10T428/2967—Synthetic resin or polymer
• • Y—GENERAL 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
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/2933—Coated or with bond, impregnation or core
  • Y10T428/2971—Impregnation
• • Y—GENERAL 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
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31511—Of epoxy ether
• • Y—GENERAL 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
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31511—Of epoxy ether
  • Y10T428/31515—As intermediate layer
• • Y—GENERAL 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
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31511—Of epoxy ether
  • Y10T428/31515—As intermediate layer
  • Y10T428/31522—Next to metal
• • Y—GENERAL 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
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31511—Of epoxy ether
  • Y10T428/31529—Next to metal
• • Y—GENERAL 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
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T442/00—Fabric [woven, knitted, or nonwoven textile or cloth, etc.]
  • Y10T442/20—Coated or impregnated woven, knit, or nonwoven fabric which is not [a] associated with another preformed layer or fiber layer or, [b] with respect to woven and knit, characterized, respectively, by a particular or differential weave or knit, wherein the coating or impregnation is neither a foamed material nor a free metal or alloy layer
  • Y10T442/2926—Coated or impregnated inorganic fiber fabric
  • Y10T442/2951—Coating or impregnation contains epoxy polymer or copolymer or polyether

Definitions

• This invention concerns a thermosetting resin system that is useful in the manufacture of high performance prepreg, laminate and composite materials as well as the prepregs, laminates and composites made from the thermosetting resin composition.
• Plastics have certain mechanical and structural properties that can be improved when the plastics are combined with reinforcing components.
• Composites formed of various fibers embedded in a polymer resin matrix, for example, are especially useful.
• Such compositions are susceptible to enormous physical property variations depending upon, for example, the nature of the fiber used, how the fiber is utilized, and the fiber matrix or binder.
• the uses for such composites range from airframes to tennis rackets and from boat hulls to rocket motor casings, and laminates for use, for example, as multilayer printed circuit boards in the electronics industry.
• thermosetting resin composition useful in the manufacture of high performance composite and laminate materials.
• the thermosetting resin composition comprises: at least one epoxy resin; at least one styrene maleic anhydride copolymer; and at least one bis-maleimidetriazine resin.
• This invention also provides prepregs, laminates and composites manufactured from the disclosed thermosetting resin compositions.
• thermosetting resin compositions useful in the manufacture of high performance composite materials, and prepregs, laminates and composites manufactured therefrom.
• the compositions are particularly useful in the preparation of laminates having low dielectric constants and low dielectric loss (“low loss”). These electrical properties help solve signal speed and signal integrity problems encountered with high speed analog digital applications manufactured using laminates with prior art resin systems.
• Laminate materials manufactured with the thermosetting resin compositions of the present invention can have low and flat dielectric loss ( ⁇ 0.01) and low dielectric constant ( ⁇ 4) at high frequency range of 2 GHz to 10 GHz, at comparatively low cost.
• “Flat dielectric loss” means that the dielectric loss is essentially constant over a range of frequencies.
• the compositions of this invention may have a dielectric loss as low as ⁇ about 0.01 over a frequency range of from 2 to 10 GHz. (As is understood by those skilled in the art, dielectric loss and constant depend on resin content and can additionally depend on other factors, such as the substrate used in a laminate).
• prepregs prepared from the compositions of this invention are also non-tacky and easy to process.
• the thermosetting resin composition includes the following ingredients: (1) at least one epoxy resin; (2) at least one styrene maleic anhydride; and (3) a bis-maleimidetriazine resin.
• the composition optionally includes one or more of the following: (4) a filler; (5) a toughener; (6) an accelerator; (7) a flame retardant; (8) a solvent; and/or (9) other additives.
• epoxy resin in this context refers to a curable composition of oxirane ring-containing compounds as described in C. A. May, Epoxy Resins, 2nd Edition, (New York & Basle: Marcel Dekker Inc.), 1988.
• the epoxy resin is added to the resin composition in order to provide the desired basic mechanical and thermal properties of the cured resin and laminates made there from.
• Useful epoxy resins are those that are known to one of skill in the art to be useful in resin compositions useful for electronic composites and laminates.
• epoxy resins include phenol types such as those based on the diglycidyl ether of bisphenol A (“Bis-A epoxy resin”), on polyglycidyl ethers of phenol-formaldehyde novolac or cresol-formaldehyde novolac, on the triglycidyl ether of tris(p-hydroxyphenol)methane, or on the tetraglycidyl ether of tetraphenylethane, or types such as those based on tetraglycidylmethylenedianiline or on the triglycidyl ether of p-aminoglycol; cycloaliphatic types such as those based on 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate.
• epoxy resin also includes within its scope reaction products of compounds containing an excess of epoxy (for instance, of the aforementioned types) and aromatic dihydroxy compounds.
• epoxy resins which are derivatives of bisphenol A (“Bis-A epoxy resin”), particularly FR4.
• FR4 is made by an advancing reaction of an excess of bisphenol A diglydicyl ether with tetrabromobisphenol A.
• Mixtures of epoxy resins with bismaleimide resin, cyanate resin and/or bismaleimide triazine resin can also be used.
• epoxy resins are generally represented by a single, unequivocal structural formula. The skilled person will know that this should be taken to include deviating products resulting from side reactions occurring during epoxy resin preparation. As these side products constitute a normal component of cured epoxy resins, they likewise constitute a normal component of the resins according to this invention.
• Epoxy resins are present in the composition of this invention in an amount from about 8% to about 26%, and preferably from about 10 to about 23%, based on 100% by weight solids of the composition.
• BPA Bisphenol A
• BPADGE bisphenol A diglycidyl ether
• Both the BPA and the BPADGE may optionally be brominated, i.e. substituted with one or more bromine atoms.
• Resin systems incorporating optionally brominated bisphenol A and optionally brominated bisphenol A diglycidyl ether that are useful in the present invention are described in U.S. application Ser. No. 09/269,014, filed Sep. 24, 1997, which is incorporated herein by reference in its entirety.
• the aromatic moieties of BPA and BPADGE are preferably substituted with two bromine atoms, to give tetrabromobisphenol A (TBBA) and tetrabromobisphenol A diglycidyl ether (TBBADGE), respectively.
• TBBA tetrabromobisphenol A
• TBADGE tetrabromobisphenol A diglycidyl ether
• brominated novolacs can also be used as co-cross-linking agent. Brominated co-crosslinking agents are preferred because of their flame retarding properties.
• the desired resin properties determine the amount of optionally brominated BPA and optionally brominated BPADGE to be incorporated into the resin.
• Tg of epoxy resins cross-linked with SMA can be increased substantially by the use of at least 5% by weight of BPA.
• a co-crosslinking agent it is generally present in amount of about 5% to about 60%, preferably about 15% to about 55%, based on 100% by weight solids of the composition.
• the composition of this invention contains both TBBA and TBBADGE.
• the TBBA is present in an amount of from about 3% to about 21 wt %, preferably from about 6% to about 19%, and the TBBADGE is present in amount of from about 9 wt % to about 30 wt %, preferably from about 11 wt % to about 26 wt %, each based on 100% by weight solids of the composition.
• thermosetting resin compositions of this invention includes one or more styrene maleic anhydride compounds (SMA).
• SMA improves the thermal and electrical properties of the resulting cured polymer and products made therefrom by reacting with unreacted elastomer ingredients and by-products.
• Copolymers of styrene and maleic anhydride have been described, inter alia, in Encyclopedia of Polymer Science and Engineering Vol. 9 (1987), page 225. Within the framework of this invention the term “copolymer” likewise refers to SMA or mixtures of SMA. Copolymers of styrene and maleic anhydrides (SMA) are commercially available in two types. Type 2 comprises mostly high-molecular weight copolymers (MW generally higher than 100,000, for instance, 1,000,000). These are in fact thermoplastics, which are unsuitable for use in the manufacture of prepregs. Moreover, because of their low anhydride content (5-15%) they are not particularly suitable for use as a crosslinking agent for epoxy resin either.
• the type 1 SMA copolymers which have a molecular weight in the range of about 1400 to about 50,000 and an anhydride content of more than 15% by weight, are especially suited for use in compositions of this invention. Preference is also given to SMA copolymers having a molecular weight in the range of 1400 to 10,000. Examples of such copolymers include the commercially available SMA 1000, SMA 2000, SMA 3000, and SMA 4000. These copolymers have a styrene maleic anhydride ratio of 1:1, 2:1, 3.1, and 4:1, respectively, and a molecular weight ranging from about 1400 to about 2000. Mixtures of these SMAs may also be used.
• SMA polymers are present in the thermosetting resin compositions of this invention in an amount from about 10% to about 26%, preferably from about 15 to about 23%, based on 100% by weight solids of the composition.
• the amount of epoxy resin exceeds the amount of SMA in order to provide an excess of functionality of the epoxy over the SMA.
• the weight ratio of epoxy resin to SMA copolymer is preferably about 2:1 to about 1.5:1 (epoxy:SMA).
• thermosetting resin compositions of this invention further includes a Bis-maleimidetriazine resin (BT).
• BT resins are commercially available from Mitsubishi.
• Bis-maleimidetriazine resins are present in the thermosetting resin compositions of this invention in an amount from about 15% to about 50%, preferably from about 25 to about 40%, based on 100% by weight solids of the composition.
• One or more fillers can optionally be added to the resin compositions of this invention to improve chemical and electrical properties of the cured resin.
• properties that can be modified with fillers include, but are not limited to, coefficient of thermal expansion, lowering CTE, increasing modulus, and reducing prepreg tack.
• useful fillers include particulate forms of Teflon®, talc, quartz, ceramics, particulate metal oxides such as silica, titanium dioxide, alumina, ceria, clay, boron nitride, wollastonite, and mixtures thereof.
• Preferred fillers include calcined clay or fused silica. Another preferred filler is fused silica. Yet another preferred filler is silane treated silica.
• the silane treated filler filler is fused silica treated with epoxy silane.
• fillers are present in the thermosetting resin compositions of this invention in an amount from about 0% to about 20%, preferably from about 0 to about 10%, based on 100% by weight solids of the composition.
• the thermosetting resin compositions of this invention may include one or more tougheners.
• the tougheners are added to the resin compositions to improve the drillability of the resulting composites and laminates.
• Useful tougheners include methyl methacrylate/butadiene/styrene copolymer, methacrylate butadiene styrene core shell particles, and mixtures thereof.
• a preferred toughener is methacrylate butadiene styrene core shell particles, which is available from Rohm & Haas (100 Independence Mall West, Philadelphia, Pa.), sold under the trade name Paraloid®.
• tougheners are present in the thermosetting resin compositions of this invention in an amount from about 1% to about 5%, preferably from about 2 to about 4%, based on 100% by weight solids of the composition.
• One or more accelerators are typically added to the composition to crosslink the resins and to enhance the rate of resin cure.
• the accelerators chosen may be any accelerators that are know to speed up the rate of thermosetting resin cure.
• suitable accelerators may be mentioned imidazoles, more particularly alkyl substituted imidazoles such as 2-methylimidazole and 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl, 4-methylimidazole.
• Other suitable accelerators include tertiary amines, e.g. benzyldimethylamine and 4,4′ and 3,3′ diaminodiphenylsulphone.
• One preferred accelerator is 2-ethyl-4-methylimidazole.
• the amount of accelerator used is dependent on the type of epoxy resin, the type of cross-linking agent, and the type of accelerator. Employing a too large amount of accelerator will lead to a too highly reactive resin system.
• the skilled person can easily determine the amount of accelerator needed to provide a resin system that is sufficiently reactive to allow ready processing into prepregs. In general, such amount will be between 0.01 and 5% by weight of accelerators, calculated on the overall weight of epoxy resin and co-crosslinking agent present in the composition. In many cases this will be the 0.01-0.05% by weight range.
• the resin gel is dependent on the type anal amount of accelerator, the type and amount of solvent, and the type of prepreg to be manufactured.
• thermosetting resin compositions of this invention may include one or more flame retardants. Any flame retardant that is known to be useful in resin compositions used to manufacture composites and laminates may be used. Examples of useable flame retardants include, but are not limited to, halides of glycidyl etherified bifunctional alcohols, halides of novolac resins such as bisphenol A, bisphenol F, polyvinylphenol or phenol, creosol, alkylphenol, catecohl, and novolac resins such as bisphenol F, inorganic flame retardants such as antimony trioxide, red phosphorus, zirconium hydroxide, barium metaborate, aluminum hydroxide, and magnesium hydroxide, and phosphor flame retardants such as tetraphenyl phosphine, tricresyl-diphenyl phosphate, triethylphosphate, cresyldiphenylphosphate, xylenyl-diphenyl phosphate, acid phosphate
• decabromodiphenylethane which has the following structure:
• Decabromodiphenylethane is commercially available, for example, from Albemarle Corporation (451 Florida St., Baton Rouge, La. 70801). The Albemarle product is sold as SaytexTM 8010. Decabromodiphenylethane has been unexpectedly found to be easily dispersed in the resin composition. Decabromodiphenylethane also has the unexpected and synergistic result of significantly improving dielectric properties of the cured resin. As a result, the flame retardant can be included in the resin composition of this invention in amounts far greater than is necessary for a flame retardant in order to also enhance the dielectric properties of the cured resin.
• decabromodiphenylethane When used as the flame retardant, it is preferably present in the thermosetting resin compositions of this invention in an amount of from about 10% to about 50%, more preferably from about 20% to about 45%, based on 100% by weight resin solids of the composition.
• a brominated flame retardant When used, it is preferably present in an amount sufficient to provide a total bromine content to the composition of about 8% to about 30%, preferably about 10 to about 20%, based on 100% by weight solids of the composition.
• One or more solvents are typically incorporated into the thermosetting resins of this invention in order to provide resin solubility, control resin viscosity, and in order to maintain the resin ingredients in a suspended dispersion.
• Any solvent known by one of skill in the art to be useful in conjunction with thermosetting resin systems can be used.
• Particularly useful solvents include methylethylketone (MEK), toluene, dimethylformamide (DMF), or mixtures thereof.
• MEK methylethylketone
• DMF dimethylformamide
• the choice of solvent is often dictated by the resin curing method. When the resin is cured with hot air, then ketones are typically the preferred solvent. When the resins are IR cured, then a mixture of ketones and toluene is typically preferred.
• solvents are present in the thermosetting resin compositions of this invention in an amount of from about 20% to about 50% as a weight percentage of the total weight of the composition.
• thermosetting resin composition of the present invention may further contain other additives such as defoaming agents, leveling agents, dyes, and pigments.
• a fluorescent dye can be added to the resin composition in a trace amount to cause a laminate prepared therefrom to fluoresce when exposed to UV light in a board shop's optical inspection equipment.
• a useful fluorescent dye is a highly conjugated diene dye.
• UVITEX® OB (2,5-thiophenediylbis(5-tert-butyl-1,3-benzoxazole), available from Ciba Specialty Chemicals, Tarrytown, N.Y.
• One useful composition of this invention has the following formulation: HIGH PERFORMANCE ELECTRICAL LAMINATE FORMULATION Preferred Ingredients Range(wt %) Amounts(wt %) Epoxy Resin Bis-A Epoxy Resin 10-26 15-23 Brominated Bis-A Epoxy (TBBADGE) 9-30 13-26 Tetrabromobisphenol A (TBBA) 7-21 11-19 SMA 10-26 15-23 Toughener 1-5 2-4 Methacrylate butadiene styrene core shell particles (Paraloid 2591) Accelerator 0.05-1.0 0.2-0.5 BT Resin 15-50 25-40 Filler 0-20 0-10
• the ingredients are suspended in a DMF, MEK or MEK/DMF solvent in a ratio ranging from about 50-80 wt % solids to 50-20 wt % solvent and preferably about 70 wt % solids to about 30 wt % solvent.
• thermosetting resin compositions of this invention are useful for making prepregs in a continuous process.
• Prepregs are generally manufactured using a core material such as a roll of woven glass web which is unwound into a series of drive rolls.
• the web then passes into a coating area where the web is passed through a tank which contains the thermosetting resin system of this invention, solvents and other components.
• the glass web becomes saturated with the resin in the coating area.
• the resin saturated glass web is then passed through a pair of metering rolls which remove excess resin from the resin saturated glass web and thereafter, the resin coated web travels the length of a drying tower for a selected period of time until the solvent is evaporated from the web.
• a second and subsequent coating of resin can be applied to the web by repeating these steps until the preparation of the prepreg is complete whereupon the prepreg is wound onto roll.
• Lamination process typically entail a stack-up of one or more prepreg layers between one or two sheets of conductive foil (such as copper foil). Lamination methods and parameters may vary widely, and are generally well known to the person of ordinary skill in the art.
• the stack In a typical cure cycle, the stack is maintained at a pressure of about 40 psi to about 900 psi and under a vacuum of about 30 in/Hg.
• the stack temperature is raised from about 180° F. to about 375° F. over a period of about 20 minutes.
• the stack remains at a temperature of about 375° F. for 75 minutes after which the stack is cooled from a temperature of 375° F. to a temperature to 75° F. over a 20 minute period.
• thermosetting resins of this invention are premixed in a mixing vessel under ambient temperature and pressure.
• the viscosity of the pre-mix is ⁇ 600-1000 cps and can be adjusted by adding or removing solvent from the resin.
• Fabric substrate typically but not limited to E glass
• thermosetting resin mix can also be coated directly on Cu substrate (RCC—resin coated Cu) using slot-die or other related coating techniques.
• thermosetting resin compositions [0037] In this example, the electrical and thermal properties of castings of the thermosetting resin compositions according to the invention were measured.
• the ingredients of the composition and their amounts are listed in Tables 1 and 2.
• Table 1 is an unfilled resin composition.
• Table 2 is a filled resin composition.
• DMF was used as solvent to provide a total solids content of about 67% for the unfilled resin composition and about 71% for the filled resin composition.
• TABLE 1 Unfilled Resin Composition Amount Ingredient (percentage of 100% solids) Epoxy resin Bis A epoxy 17% TBBA 11% TBBADGE 17% SMA 22.5% BT resin 30% 2-ethyl-4-methylimidazole 0.08% Toughener (Paraloid ®) 2.4% Fluorescent dye (Uvitex ® OB) 0.02%

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• 2002
  • 2002-12-05 WO PCT/US2002/038949 patent/WO2003048251A1/en not_active Application Discontinuation
  • 2002-12-05 EP EP02804513A patent/EP1461387B1/de not_active Expired - Lifetime
  • 2002-12-05 AT AT02804513T patent/ATE544819T1/de active
  • 2002-12-05 AU AU2002365609A patent/AU2002365609A1/en not_active Abandoned
  • 2002-12-05 US US10/310,418 patent/US20030158337A1/en not_active Abandoned
• 2005
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• 2009
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• 2010
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