Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From carboxylic acid or derivative thereof
Reexamination Certificate
2001-06-18
2004-12-28
Higtower, P. Hampton (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From carboxylic acid or derivative thereof
C528S170000, C528S322000, C528S323000, C528S324000, C528S328000, C528S332000, C528S335000, C528S342000, C428S357000, C428S394000, C428S395000, C428S474400
Reexamination Certificate
active
06835799
ABSTRACT:
The invention relates to a randomly branched polyamide comprising at least units derived from:
1. AB monomers,
2. at least one compound I, being a carboxylic acid (A
v
) having a functionality v≧2 or an amine (B
w
) having a functionality w≧2,
3. at least one compound II, being a carboxylic acid (A
v
) having a functionality v≧3 or an amine (B
w
) having a functionality w≧3, compound II being a carboxylic acid if compound I is an amine or compound II being an amine if compound I is a carboxylic acid.
In the context of this application, with the term “randomly branched” is meant that the branching points are randomly distributed in the polyamide chain.
Such a randomly branched polyamide is known from EP-345.648-B1. However, a problem encountered with the randomly branched polyamide according to EP-345.648-B1 is that the randomly branched polyamide is not intrinsically gel-free so that, while the randomly branched polyamide can for instance be obtained as a gel-free melt, during further processing of the randomly branched polyamide, gel formation may as yet occur. In the context of this application gel formation is understood to be a process involving the formation of a network in a polymer material. Gel formation gives rise to, among other things, the formation of visible inhomogeneities (“gels”) during processing of the randomly branched polyamide into, for instance, films or fibres and to deterioration of the mechanical properties of polyamide objects obtained from the randomly branched polyamide. It is also known that when randomly branched polyamide is processed in equipment where local overheating may take place or where polyamide material may accumulate, for instance in extruders and mixers, it may contain strongly crosslinked polyamide.
It is desirable to have intrinsically gel-free randomly branched polyamide available. In the context of this application “intrinsically gel-free” is understood to mean that the composition of the randomly branched polyamide is such that it cannot form crosslinked polyamide (and therefore no gels), in particular during the prepolymerization, the polymerization, the post-condensation, the processing, for instance into films or fibres, and the storage of the randomly branched polyamide, and this at a variety of ambient factors, for instance at elevated temperature and pressure.
Although the prevention of gel formation in polymeric materials has been receiving a great deal of attention in practice, at this point of time neither a structural nor a systematic approach is known to provide an adequate solution to the problem of obtaining intrinsically gel-free, randomly branched polyamide from AB monomers.
It is the aim of the inventors to provide such an intrinsically gel-free, randomly branched polyamide comprising at least units derived from:
1. AB monomers,
2. at least one compound I, being a carboxylic acid (A
v
) having a functionality v≧2 or an amine (B
w
) having a functionality w≧2,
3. at least one compound II, being a carboxylic acid (A
v
) having a functionality v≧3 or an amine (B
w
) having a functionality w≧3, compound II being a carboxylic acid if compound I is an amine or compound II being an amine if compound I is a carboxylic acid.
This aim is achieved when the amounts of all units derived from carboxylic acids and amines in the polyamide satisfy formula 1
P>
1/[(
F
A
−1).(
F
a
−1)] (1)
where:
P=
[&Sgr;(
n
i
.f
i
)]
x
/[&Sgr;(
n
i
.f
i
)]
y
(2)
where P≧1 and either X=A and Y=B, or X=B and Y=A, and
F
x
=&Sgr;(
n
i
.f
i
2
)/&Sgr;(
n
i
.f
i
) (3)
for, respectively, all carboxylic acids (X=A) and all amines (X=B), where f
i
is the functionality of either the carboxylic acid (f
i
=v
i
) or amine (f
i
=w
i
), n
i
being the number of moles of the carboxylic acid or amine and the summation involving all units derived from carboxylic acids and amines in the polyamide.
In the context of the present invention AB monomer is understood to be a monomer that has both a carboxylic acid group (A) and an amino group (B).
In the context of the present application compound I and compound II are also understood to be mixtures of several carboxylic acids having the same functionality or mixtures of several amines having the same functionality.
In the context of the present application carboxylic acid and amine are understood to be, respectively, a compound which, besides one or more carboxylic acid groups, does not carry any amine groups and the other way round. It therefore follows that units derived from carboxylic acids or amines in the polymer have a chemical composition that differs from chat of the units derived from the AB monomers. Carboxylic acid group is in the context of the present application understood to be a group that can form a covalent bond with an amine group, for instance —COOH, —COHal (Hal=halogen), —CO
2
R in which R is an alkyl residue with 1 to 20 carbon atoms and —SO
2
Hal (Hal=halogen).
In the context of the present application functionality is understood to be the number of functional groups in the carboxylic acid or the amine that can form a bond with other carboxylic acids, amines or AB monomers to form the randomly branched polyamide according to the invention A functional group that cannot form this bond, for instance a sterically hindered amine group or an aromatic amine group, is not considered as a functional group in determining the functionality. Likewise, the functionality is equated to 1 if two functional groups at a compound are both involved in a single bond with a third functional group, for instance two COOH groups that are close together which form an imide bond with an amine, for instance in the compound orthodicarboxy-benzene.
Preferably, the functionality v or w of compound I can be chosen from 2, 3, 4, 5 and 6. More preferably, the functionality of compound I is 2. Preferably, the functionality v or w of compound II can be chosen from 3, 4, 5 and 6, more preferably, the functionality of compound II is 3.
Eligible AB monomers are all AB monomers that can be used for the production of polyamides, in particular &agr;,&ohgr;-amino acids and/or lactams, for instance caprolactam, laurine lactam and dodecalactam, as well as the corresponding amino acids and aromatic amino acids, for instance p-(aminomethyl)-benzoic acid. Preferably, the lactam is &egr;-caprolactam.
Eligible carboxylic acids (A
v
) are preferably difunctional carboxylic acids, for instance adipic acid, dodecane dicarboxylic acid, isophthalic acid and terephthalic acid and trifunctional carboxylic acids, for instance 1,3,5-tris(caproic acid)melamine, trimesic acid and trimeric fatty acids with 50-60 carbon atoms as well as esters and anhydrides of said carboxylic acids. Preferably, the difunctional carboxylic acid is terephthalic acid. Preferably, the trifunctional carboxylic acid is 1,3,5-tris(caproic acid)melamine (TCAM) or trimesic acid.
Eligible amines (B
w
) are preferably difunctional amines, for instance diaminobutane, diaminohexane, diaminododecane, cyclic amines, for instance 1,4-diaminocyclohexane, 4,4′-diaminobicyclohexylamine, 1,3- and 1,4-xylylene diamine and trifunctional amines, for instance trisaminononane and bis (hexamethylene triamine). Preferably, the difunctional amine is 1,6-hexamethylene diamine. Preferably, the trifunctional amine is bis (hexamethylene triamine).
Besides the units derived from compounds I and II according to the invention also other units derived from carboxylic acids and amines may be present, for instance monofunctional carboxylic acids and amines (chain terminators).
Although the aim of the invention according to ZP-345.648-B1 is not the aim of the present invention, while said publication does not mention the measures according to the present invention, either, it does mention, besides a number of randomly branched polyamides that do not satisfy the measures according to the present invention, also a num
Aberson Rene
Nijenhuis Atze J.
Scholtens Boudewijn J. R.
DSM IP Assets B. V.
Higtower P. Hampton
Mayer Brown Rowe & Maw LLP
LandOfFree
Intrinsically gel-free, randomly branched polyamide does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Intrinsically gel-free, randomly branched polyamide, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Intrinsically gel-free, randomly branched polyamide will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3296646