Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Patent
1991-02-06
1992-10-13
Kight, III, John
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From phenol, phenol ether, or inorganic phenolate
525507, 528129, 549560, 549517, 568719, C08G 6508, C08L 6114
Patent
active
051552027
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to resins having a higher heat resistance and lower water absorption, cured substances therefrom useful for materials to be used in sealing or laminating electronic parts, and a method for producing the same.
BACKGROUND ART
Conventionally resin compositions containing epoxy resins, phenolic novolak resins, and cure promoters have been extensively used in the field of electric and electronic parts, especially as sealants for IC. In recent years, however, development of electronic materials have led to high level of storage and packing densities which in turn require particularly a sealant to have a higher resistance to heat and a lower water absorption. Above all, severe conditions such as immersion in a soldering bath as conducted in providing high density packing have posed an increasing need for cured substances to have a higher resistance to heat and a lower water absorption. However, conventional compositions such as cresol novolak epoxide resins commonly used as epoxy resins have insufficient heat resistance under the severe condition of immersion in a soldering bath. Similarly, polyepoxide compounds produced by epoxidation of polyphenols which are produced by condensation of phenols and aromatic aldehydes having a phenolic hydroxyl group have been proposed as those having a heat resistance as disclosed in Japanese Patent KOKAI (Laid-open) No. Sho 63-264622. However, they are less preferred in water absorption than cresol novolak epoxide resins.
Japanese Patent KOKOKU (Post-Exam.) No. Sho 62-20206 proposes polyglycidyl ethers derived from condensation of .alpha.-naphthol and form aldehyde as resins capable of producing cured substances excellent in heat resistance. The polyglycidyl ethers are excellent for an increased resistance to heat imparted by incorporation of naphthalene rings, but suffer from higher softening points, or higher melt viscosities caused by the incorporation of naphthalene rings resulting in an disadvantage of poor workability.
On the other hand, phenolic novolak resins commonly used as curing agent are still unsatisfactory in heat resistance. An attempt has been made to enhance the heat resistance by reducing the content of lower molecular weight components (such as binuclear phenol novolaks) still resulting in unsatisfactory resistance under severer conditions (for example, immersion in a soldering bath).
DISCLOSURE OF THE INVENTION
The present invention provides a resin capable of producing cured substances which can withstand such severer conditions and exhibits higher resistance to heat and lower water absorption, and in addition has a good workability. The present inventors have discovered that introducing naphthol rings into epoxy resins and curing agents can achieve a higher resistance to heat and a lower water absorption as well as a good workability. The present invention has been accomplished based on such discovery.
That is, the present invention provides: general formula [I]: ##STR3## wherein X is H or ##STR4## R is an alkyl group having 1 to 4 carbon atoms, and n is 1 to 10;
(2) a phenolic novolak resin according to the item (1) wherein the compound is a phenolic novolak compound represented by the general formula [II]: ##STR5## wherein R is an alkyl group having 1 to 4 carbon atoms;
(3) a phenolic novolak resin according to the item (2) wherein the compound is a phenolic novolak compound represented by the general formula [III]: ##STR6##
(4) a phenolic novolak resin according to the item (3) wherein the compound is a phenolic novolak compound represented by the general formula [IV]: ##STR7##
(5) a phenolic novolak resin according to the item (1) wherein the compound is a phenolic novolak compound represented by the general formula [V]: ##STR8## wherein m is 2 to 10;
(6) a phenolic novolak resin according to the item (5) wherein the compound is a phenolic novolak compound represented by the general formula [VI]: ##STR9##
(7) a phenolic novolak resin according to the item (1) wherein the compound is a phenolic novol
REFERENCES:
patent: 4404357 (1983-09-01), Taylor et al.
patent: 4424315 (1984-01-01), Taylor et al.
patent: 4551409 (1985-11-01), Gulla et al.
patent: 4551508 (1985-11-01), Urasaki
Kimura Ichiro
Morita Hiromi
Murata Kazuyuki
Nagao Susumu
Jones Richard Lee
Kight III John
Nippon Kayaku Kabushiki Kaisha
LandOfFree
Phenolic novolak resins, cured substances therefrom and method f does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Phenolic novolak resins, cured substances therefrom and method f, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Phenolic novolak resins, cured substances therefrom and method f will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1301526