Plastic and nonmetallic article shaping or treating: processes – Forming articles by uniting randomly associated particles – Utilizing diverse solid particles
Reexamination Certificate
2000-05-19
2001-10-02
Theisen, Mary Lynn (Department: 1732)
Plastic and nonmetallic article shaping or treating: processes
Forming articles by uniting randomly associated particles
Utilizing diverse solid particles
C264S109000, C264S119000
Reexamination Certificate
active
06296795
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to non-woven fibrous batts, shaped articles, fiber binders and related processes for the production of these fibrous batts and shaped articles.
BACKGROUND OF THE INVENTION
Some years aqo processes were developed for producing fibrous batts by contacting fibers with a dry fiber-binder based on certain thermoplastic polymers. Such processes are described in the following U.S. Patents among others:
Buck et al U.S. Pat. No. 3,993,518, “Buck '518”;
Buck et al U.S. Pat. No. 3,997,942, “Buck '942”;
Buck et al U.S. Pat. No. 4,047,991, “Buck '991”;
Buck et al U.S. Pat. No. 4,050,997, “Buck '997”;
Buck et al U.S. Pat. No. 4,051,294, “Buck '294”;
Buck et al U.S. Pat. No. 4,053,673, “Buck '673”;
Buck et al U.S. Pat. No. 4,053,674, “Buck '674”;
Buck U.S. Pat. No. 4,211,817, “Buck '817”;
Buck et al U.S. Pat. No. 4,363,680, “Buck '680”;
Buck U.S. Pat. No. 4,550,050, “Buck '050”;
Buck U.S. Pat. No. 4,457,793, “Buck '793”;
Buck et al U.S. Pat. No. 4,473,428, “Buck '428”; and
Elsen U.S. Pat. No. 4,869,950, “Elsen”.
These prior processes became commercially successful in the Unites States of America and in a number of overseas countries because of their advantages over the prior art, as set forth in the above patents. However, over the ten or fifteen years of their widespread use the cost of the polyvinylidene-polyvinyl chloride copolymer (“PVDC/PVC copolymer”) used in these processes increased dramatically so that these processes became uneconomic. For several years scrap PVDC/PVC copolymers were available but eventually the supply of these materials became insufficient to satisfy the market. In addition certain disadvantages associated with the use of PVDC/PVC copolymers and other chlorinated materials, including corrosion of equipment, restricted the use of these materials in certain applications. Since the PVDC/PVC copolymers were thermoplastic, they suffered from an additional disadvantage in that they could not be hot molded into certain shaped articles useful for example as automobile insulating products.
More recently a new type of dry powder bonding system was developed by this inventor as described in Buck U.S. Pat. No. 5,804,005, (Buck '005) and in Buck U.S. Pat. No. 6,039,821 (Buck '821) and in a number of foreign countries which are signatory to the Patent Cooperation treaty (“PCT”). Several other patents based on the same or similar chemistry are currently pending. Buck '005 and Buck '821 employ epoxy polymers in dry powder form which when distributed throughout a fibrous batt can be advanced to high molecular weights and cured to either the B stage or more fully cured to the C stage by processing methods described in these two patents. The B stage products may be molded into various shapes in a heated mold such as is used to mold phenolic polymers and certain other thermosetting polymers. In order to maintain firmness during and immediately after the hot molding process which may be carried out at 200° to 230° C., catalysts and agents which cause the epoxide chain molecules to cross link with each other must be employed. Examples include trimelletic anhydride, tetracarboxy benzene dianhydride, and other multi-functional cross-linking agents. These agents are quite expensive, however, and even they do not raise the glass transition temperature (T
g
) of the epoxide polymer sufficiently to hold the molded batt in a firm and rigid position immediately upon its removal from the molding press.
The epoxide polymers themselves are relatively expensive; the cross-linking agents are even more costly; and the results of hot molding are not equivalent to those obtained with phenol formaldehyde or novalac polymers. Consequently these epoxide bonded and molded products, while having the desirable advantages of freedom from phenol or formaldehyde, are not competitive in the market place. In fact, while the process of Buck '005 has achieved commercial success in the USA and a number of other countries, the commercial products have been based on scrap powder paint with an epoxide base. Powders formulated from these materials function very effectively in flat cushion batts and semi-compressed materials and possess many advantages over earlier technologies, including freedom from chlorine, from phenol, from formaldehyde, and from other undesirable bi-products. The batts made from scrap powder paint, which compete effectively with phenolic and novalac polymers in flat, non-molded fibrous batts cannot be molded with the rigidity obtainable with the phenolic polymers.
OBJECTS OF THE INVENTION
The prime object of the current invention is to utilize a bonding material in fine, dry powder form which is inexpensive enough to compete with phenolic polymers and function as well or better in producing the hardness and shape-holding properties of batts bonded with those polymers, yet at the same time is entirely free from the odors, noxious gases, discoloration, and toxicity associated with formaldehyde-containing batts which are widely used in many molded products throughout the world but which are believed to pose a significant health hazard both in processing and in the fibrous products made from them. Surprisingly a method has been discovered, which is described in this invention, which accomplishes these objectives with great satisfaction and effectiveness.
Another object of the present invention is to provide an improved process which is substantially free of one or more of the other disadvantages of the prior processes.
Still another object is to provide an improved process which produces a batt which has an improved flexural strength both when hot and when cold.
An additional object is to provide an improved process for the production of batts and molded articles which exhibit improved tensile strength in the presence of moisture.
Still another object is to provide an improved shaped article.
Yet another object is to provide a fiber binder which can advantageously be used in the process of the present invention.
Additional objects and advantages of the present invention will be apparent to those skilled in the art by reference to the following description and drawings.
REFERENCES:
patent: T101102 (1981-10-01), Turner
patent: 3723223 (1973-03-01), LeCompte
patent: 3765971 (1973-10-01), Fleissner
patent: 3943981 (1976-03-01), Brabander
patent: 3993518 (1976-11-01), Buck
patent: 3997942 (1976-12-01), Buck
patent: 4012549 (1977-03-01), Slysh
patent: 4014726 (1977-03-01), Fargo
patent: 4047991 (1977-09-01), Buck
patent: 4051294 (1977-09-01), Buck
patent: 4053673 (1977-10-01), Buck
patent: 4053674 (1977-10-01), Buck
patent: 4139698 (1979-02-01), Watts
patent: 4147737 (1979-04-01), Sein
patent: 4197349 (1980-04-01), Walser
patent: 4211817 (1980-07-01), Buck
patent: 4212704 (1980-07-01), Durand
patent: 4221602 (1980-09-01), Walser
patent: 4233046 (1980-11-01), Walser
patent: 4363680 (1982-12-01), Buck
patent: 4397756 (1983-08-01), Lehmann
patent: 4457793 (1984-07-01), Buck
patent: 4470877 (1984-09-01), Johnstone
patent: 4473428 (1984-09-01), Buck
patent: 4476175 (1984-10-01), Forry et al.
patent: 4524164 (1985-06-01), Viswanathan
patent: 4528127 (1985-07-01), Holderegger
patent: 4548676 (1985-10-01), Johnstone
patent: 4550050 (1985-10-01), Buck
patent: 4585685 (1986-04-01), Forry
patent: 4609686 (1986-09-01), Giordzno
patent: 4714096 (1987-12-01), Guay
patent: 4804414 (1989-02-01), Gleason
patent: 4869950 (1989-09-01), Elsen
patent: 4874661 (1989-10-01), Brown
patent: 4900615 (1990-02-01), Kissell
patent: 4940513 (1990-07-01), Spendel
patent: 4959125 (1990-09-01), Spendel
patent: 5026746 (1991-06-01), Floyd
patent: 5059282 (1991-10-01), Ampulski
patent: 5095054 (1992-03-01), Lay
patent: 5100435 (1992-03-01), Onwumere
patent: 5130394 (1992-07-01), Nguyen
patent: 5164046 (1992-11-01), Ampulski
patent: 5194206 (1993-03-01), Koch
patent: 5288318 (1994-02-01), Mayer
patent: 5290350 (1994-03-01), Besnard
patent: 5321100 (1994-06-01), Belder
patent: 5334639 (1994-08-01), Rice
patent:
Murphy David R.
Theisen Mary Lynn
LandOfFree
Non-woven fibrous batts, shaped articles, fiber binders and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Non-woven fibrous batts, shaped articles, fiber binders and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Non-woven fibrous batts, shaped articles, fiber binders and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2583356