Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Patent
1996-01-19
1998-01-20
Seidleck, James J.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From phenol, phenol ether, or inorganic phenolate
528112, 528297, 528354, 528355, C08G 5940, C08G 6500, C08G 6308
Patent
active
057102341
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention relates to novel ortho spiroesters useful for formulating a resin composition which cures with either low shrinkage or expansion during molding and to a resin composition of low curing shrinkage containing said ortho spiroesters and a cured product of said composition.
BACKGROUND TECHNOLOGY
In general, thermosetting resins such as epoxy resins, unsaturated polyesters and polyfunctional (meth)acrylic resins cure invariably with shrinkage and this leads to cracking and poor appearance by internal stress. Even epoxy resins, known to cure with the least shrinkage among a variety of thermosetting resins, undergo a volume shrinkage on the order of 3 to 6% and thereby pose a number of problems.
Remedial measures hitherto adopted are, for example, an addition of inorganic fillers such as silica, calcium carbonate and alumina to lower the degree of curing shrinkage on a relative scale. The resin compositions in question, however, increase in viscosity as a result of the addition of fillers and become difficult to cast at low temperature.
Attempts have been made to prevent volume shrinkage by adding resins that are inert and miscible with epoxy resins to epoxy resins as disclosed in Japan Tokkyo Koho No. Sho 58-57,423 (1983). This approach, however, is not desirable as it often tends to deteriorate the properties, particularly the heat resistance, of cured resins.
Apart from the aforementioned attempts, studies are in progress to reduce the degree of shrinkage by modifying resins alone. For example, 1,4,6-trioxaspiro(4,4)nonane which is prepared by the reaction of ethylene oxide with .gamma.-butyrolactone is known as a monomer that undergoes no Polymers obtained by ring-closing polymerization of this compound are thermoplastic, but they could become thermosetting when the compound is Sci., Polym. Shimp., 56, 117 (1976)!.
According to the aforementioned scheme, ortho spiroesters containing a hydroquinone or 2,2-bis(4-hydroxyphenyl)propan skeleton are ring-opened and cured at room temperature for 24 hours in the presence of boron trifluoride-diethyl ether complex as a catalyst. This procedure can reduce the shrinkage substantially to zero during curing.
Ortho spiroesters, however, are solids or highly viscous liquids at room temperature and, in commercial uses as casting materials or adhesives, they are often mixed with diluents of larger curing shrinkage. Ortho spiroesters, however, are known to cure with lower heat resistance than epoxy resins. Hence, they cannot be used in high proportions in the cases where they are used in admixture with diluents of larger curing shrinkage in applications requiring high heat resistance.
Screen printing has been used widely in the conventional patterning. This technique, however, generates such phenomena as bleeding and smudging and is finding it difficult to cope with the trend for higher density and accuracy in patterning. To solve this problem, patterning by dispense of resist formulations based on photosensitive resins is drawing attention. Resists of this kind are, for example, dry-film photoresists and liquid developable resist inks.
Dry-film photoresists, however, tend to trap air bubbles during lamination under heat and also leave some uncertainty about heat resistance and adhesive properties. Besides, they are expensive.
On the other hand, liquid resists are tacky after precure and cause soiling of masks. In consequence, liquid resists are not amenable to a procedure of close-contact exposure which contributes to higher resolution and is advantageous to tapering. Furthermore, liquid photoresists currently available on the market use organic solvents as developing solutions and these solvents are potential air pollutants and also expensive. For example, Japan Kokai Tokkyo Koho No. Sho 61-243,869 (1986) discloses photosensitive resin compositions which are mainly composed of phenol novolak resins and can be developed with a weakly alkaline aqueous solution. The compositions in question, however, suffered loss of their adhesive strength to
REFERENCES:
patent: 4368314 (1983-01-01), Endo et al.
patent: 4574132 (1986-03-01), Sayles
patent: 4707534 (1987-11-01), Schult
patent: 4738899 (1988-04-01), Bluestein et al.
patent: 5369192 (1994-11-01), Ko et al.
Fujishiro Koichi
Furukawa Masaya
Teramoto Takero
Watanabe Kazuhiro
Gulakowski Randy
Nippon Steel Chemical Co. Ltd.
Nippon Steel Corporation
Seidleck James J.
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