Bismaleimide Laminating resin

TG-MS is an ideal technique for identifying residual volatiles in polymers. The detection of residual volatiles (and of other impurities) can often yield clues as to manufacturing processes. In many cases, such as in the determination of highly volatile materials, of residual solvents or plasticisers, use of TG-MS is requested. Specifically, there are reports on the entrapment of curing volatiles in bismaleimide laminates [145] and elastomers [48], on the detection of a curing agent (dicumylperoxide) in EPDM rubbers and of bromine flame retardants in electronic waste [50], of plasticisers such as bambuterol hydrochloride [142] or TPP and diethylterephthalate in cellulose acetate [143], on solvent extraction and formaldehyde loss in phenolic resins [164], and on the evolution of toxic compounds from PVC and polyurethane foams [146]. 

JP 62246978 (Japanese) 1987 Heat-resistant adhesives containing siloxanes and imide-containing resins Shin-Etsu Chemical Industry Co. Ltd., Japan S Ueno, N Nakanishi, S Hoshida Adhesives showed good adhesion and flexibility useful in the preparation of flexible laminates Resin was prepared from the reaction product of bismaleimides, diamines, amino-terminated siloxanes and a bisphenol A cyanate adduct. The adhesive formulation was used on polyimide films... 

The majority of base materials for circuit boards are combinations of a copper foil with a laminate, where the laminate itself consists of a carrier material and a resin. Thus properties of the base material such as mechanical strength, dimensional stability, and processi-bility are determined primarily by the carrier material. On the other hand, the resin materials are responsible for the thermomechanical and electrical properties as well as for its resistance against chemicals and moisture. Frequently used carrier materials are based on glass and carbon fibers, papers, and polyamide, whereas the majority of the laminating resins are thermosets such as epoxies, phenolics, cyanates, bismaleimide triazine (BT) resins, maleimides, and various combinations of these [13]. 

Bismaleimides (BMI) are formed from methylene dianiline and maleic anhydride. They are laminating resins that prepreg well and can be produced on conventional... 

Polybismaleimide (molding resin) Polybismaleimide filament winding and laminating resin Bismaleimide/epoxy adhesive Bismaleimide/ epoxy... 

Blends of bismaleimides with poly(betaamino crotononitrile) are storage stable materials, converted with heat to thermosetting compositions useful as coating and laminating resins. 

Figure 12.15 Temperature dependence of the transverse thermal expansion coefficients of a bismaleimide modified epoxy resin—based carbon fibre composite (Narmco Rigidite 5245C) dry (continuous curve) and wet (dashed curve). The hatching illustrates the differing constrained shrinkages (and hence thermal strain) for wet and dry laminates [23,24].

The resin systems primarily used for laminates are bismaleimides, epoxies, melamines, polyesters, polyimides, silicones, and phenolics and cyanate esters. These resins are described in Sec. 2.7.8, and the reinforcements are described in Sec. 2.6.3. 

The major use of CE resins is in the electronic industry, including printed wiring circuit boards, thin cards, multichip module laminates and ship encapsulants. CE resins have replaced epoxy and bismaleimide resins to a great extent for such microelectronic application due to their comparatively lower moisture absorption and dielectric dissipation factor. 

BMI provides a continuous service temperature of 177°C in a moist environment. These are often used in high-temperature laminates and as adhesives in the electrical/ electronics industries. Major suppliers of bismaleimide resins are Rhone Poulenc Inc. Kerimid) and Technochemie GmbH, BTL Specialty Resins, Ciba-Giegy, and Mitsubishi Petrochemical Co. 

Rajabi Laleh, and Malekzadeh Ghodratollah. Effects of bismaleimide resin on dielectric and dynamic mechanical properties of epoxy-based laminates. Iran. Polym. J. 15 no. 6 (2006) 447-455. 

Epoxy resin-based laminates are the workhorse of virtually all consumer and commercial electronic products. There are several variations of this pervasive laminate family, each developed to answer a special need. Among these are standard FR-4, multifunctional epoxy, difunctional epoxy, tetrafunctional epoxy, and BT or bismaleimide triazine blends. Each of these was developed to answer the need for a resin with a successively higher Tg or glass transition temperature. Multifunctional epoxy is the most commonly used form. 

In the presence of tertiary amines, bismaleimides will undergo polyaddition reaction with hydantoin, bishydantoins, " or thio-hydantoins to give moldings and laminates with good heat resistance, mechanical and electrical properties. It is assumed that resin prepared from A,A -[4,4-diphenyl(methane)] bismaleimide and hydantoin has the following structural unit. 

The resin matrix is usually a formulated thermoset system (i.e. a reactive matrix, which on the application of heat and pressure, chemically reacts to form an infusible reinforced laminate). The thermosetting matrices are most often based on epoxy chemistries although there are plenty of examples of phenolic, bismaleimide and polyimide matrices (for example, the HexPly range from Hexcel Composites) and a few where the resin is based on cyanate esters. Thermoplastic matrices are also encountered (i.e. matrices that can change from a solidus to a liquidus form by tbe application of heat and pressure and then revert to the solid state on cooUng) which are usually, but not exclusively, based on polysulphone, polyetbersulphone or polyether ether ketone chemistries. 

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