Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Patent
1984-05-23
1986-03-25
Welsh, Maurice J.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
524105, 524100, 524209, 524239, C08K 372, C08K 334
Patent
active
045784221
DESCRIPTION:
BRIEF SUMMARY
FIELD OF TECHNOLOGY
This invention relates to a novel acetal resin composition, and more specifically, to a glass-reinforced acetal resin having excellent mechanical strength and heat stability.
BACKGROUND TECHNOLOGY
It has previously been known to reinforce an acetal resin with glass fibers (see Japanese Patent Publication No. 28191/1969). Since, however, the acetal resin is chemically inert, mere mixing of the acetal resin with a reinforcing material such as glass fibers or glass powder does not produce a reinforcing effect, and in an extreme case, the mechanical strength of the resulting mixture becomes lower than the non-reinforced polyacetal resin.
To improve upon this point, methods have been proposed in which glass fibers are treated with aminosilane, vinylsilane or epoxysilane, and isocyanates, polycarbodiimide, alkoxymethylmelamines, etc. are used as coupling agents. Methods are also known to coat glass fibers themselves with a phenoxy resin, a polyamide, polyurea, polystyrene, etc. and to blend the coated glass fibers with an acetal resin.
These methods, however, have various defects in industrial practice. For example, they are expensive, the increase in mechanical strength is small, the heat stability of the resulting molding material is markedly impaired, and its toxicity is high.
Some of the present inventors previously found and proposed that the reinforcing effect of glass fibers or powder on an acetal resin can be greatly increased by incorporating a polyfunctional cyanate ester (or its prepolymer) or a mixture (or pre-reaction product) of a polyfunctional cyanate ester (or its prepolymer) and a polyfunctional maleimide (or its prepolymer) in the acetal resin (see Japanese Laid-Open Patent Publication No. 98,356/1983).
DISCLOSURE OF THE INVENTION
It is an object of this invention to provide a novel glass-reinforced acetal resin composition.
Another object of this invention is to provide a glass-reinforced acetal resin composition in which glass fibers or glass powders have excellent adhesion to the acetal resin.
Still another object of this invention is to provide a glass-reinforced resin composition having excellent mechanical strength and heat stability.
Further objects and advantages of this invention will become apparent from the following description.
According to this invention, these objects and advantages are achieved by an acetal resin composition comprising polyfunctional maleimide or its prepolymer, and maleimide,
The acetal resin (A) used in this invention may be a homopolymer or copolymer having oxymethylene units. Preferably, the acetal resin is composed mainly (in a proportion of at least 50 mole % based on the entire recurring units) of oxymethylene units, or substantially of oxymethylene units and oxyalkylene units having at least 2 carbon atoms (preferably 2 to 9 carbon atoms). Especially preferably, the acetal resin is composed substantially of oxymethylene units; or contains not more than 40 mole % (preferably not more than 10 mole %) of oxyalkylene units having at least 2 carbon atoms and is composed substantially of oxymethylene units and oxyalkylene units.
The acetal resin is produced, for example, from a formaldehyde monomer or a cyclic oligomer such as its trimer (trioxane) or tetramer (tetraoxane) as a starting material (in which case, an oxymethylene homopolymer composed substantially only of oxymethylene units is obtained), or from the above material and a cyclic ether such as ethylene oxide, propylene oxide, epichlorohydrin, 1,3-dioxolane, 1,3-dioxepane, a formal of a glycol and a formal of a diglycol (in which case an oxymethylene copolymer composed of oxymethylene units and units of an oxyalkylene having at least 2 carbon atoms is obtained).
Such manufacturing methods are well known in the art.
The polyfunctional cyanate ester or its prepolymer used in the composition of this invention denotes a polycyanate ester having at least two cyanate ester groups in the molecule or its prepolymer.
Preferably, the polycyanate ester is a compound represented by th
REFERENCES:
patent: 4506053 (1985-03-01), Sakurai et al.
Kawata Toshikatsu
Kiboshi Shinji
Miyawaki Junichi
Sakurai Masanori
Umemura Toshikaju
Mitsubishi Gas Chemical Company Inc.
Moore M. L.
Welsh Maurice J.
LandOfFree
Acetal resin composition does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Acetal resin composition, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Acetal resin composition will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-631268