Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From carboxylic acid or derivative thereof
Reexamination Certificate
2001-08-17
2004-03-16
Boykin, Terressa (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From carboxylic acid or derivative thereof
C525S066000, C525S09200D, C525S166000, C525S167000, C525S434000, C528S272000
Reexamination Certificate
active
06706851
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to polyetheresteramides (B) containing in their chain elements bearing sulphonate groups. Polyetheresteramides (B) are copolymers obtained from the condensation of polyamide blocks containing carboxylic chain ends with polyetherdiol blocks essentially comprising alkylene oxide units and preferably ethylene oxide —(C
2
H
4
—O)— units. The incorporation of elements bearing sulphonate groups into the polyetheresteramide chain improves its intrinsic antistatic properties.
The present invention also relates to the addition of these polyetheresteramides (B) to thermoplastic polymers (A) to make them antistatic.
It is concerned with giving the thermoplastic polymer (A) antistatic properties. The formation and retention of static electricity charges at the surface of most plastics are known. The presence of static electricity on thermoplastic films leads, for example, to these films sticking together, making them difficult to separate. The presence of static electricity on wrapping films can cause the accumulation of dusts on the objects to be wrapped and thus inconvenience their use. Static electricity can also damage microprocessors or constituents of electronic circuits. Static electricity can also cause the combustion or explosion of flammable materials such as, for example, expandable polystyrene beads containing pentane.
The prior art discloses antistatic agents such as ionic surfactants of the sulphonate or ethoxylated amine type which are added to polymers. However, the antistatic properties of the polymers depend on the ambient humidity and they are not permanent since these agents migrate to the surface of the polymers and disappear. Copolymers containing polyamide blocks and hydrophilic polyether blocks have thus been proposed as antistatic agents, these agents having the advantage of not migrating and thus of giving permanent antistatic properties that are more independent of the ambient humidity.
THE PRIOR ART
U.S. Pat. No. 3,296,204 discloses linear polyamide fibres obtained by reacting 5-sulphoisophthalic acid with a diamine followed by polycondensation with an amino acid or a salt of diamine and diacid such as hexamethylene adipate. These fibres have good dyeing ability and absorb humidity like natural fibres. They are not polyetheresteramides.
Patent application JP 11 029 685 A published on Feb. 2, 1999 discloses antistatic acrylic resins containing polyetheresters obtained by condensation of polyoxyalkylene glycol and of dicarboxylic acids. Some of these diacids contain sulphonic groups. These polyetheresters are not polyetheresteramides.
Patent application JP 08 208 830 A published on Aug. 13, 1996 discloses hydrophilic elastomers containing 5-sulphoisophthalic salts and adducts of ethylene oxide with an aromatic diol. The polyetheresteramides are not clearly described. There is no description of blocks consisting of copolyamide or of polyamide oligomers of low molecular masses.
U.S. Pat. No. 5,096,995 discloses polyetheresteramides containing two types of polyether blocks, that is to say polyether blocks of the polyethylene glycol type and blocks that are adducts of ethylene oxide with an aromatic diol. The chain limiter for the polyamide blocks is a dicarboxylic acid; mention is made of diacids bearing a sulphonate group, such as the sodium salt of 3-sulphoisophthalic acid, and unsubstituted diacids, but it is preferred to use unsubstituted acids such as terephthalic acid, isophthalic acid, 1,4-cyclohexanedicarboxylic acid, sebacic acid, adipic acid or decanedicarboxylic acid. None of the examples uses diacids bearing sulphonate groups. The polyamide blocks disclosed in the examples consist of caprolactam or lauryllactam; copolyamides and polyamide oligomers of low molecular masses are not described.
Patent application JP 05 140 541 A published on Jun. 8, 1993 discloses polyetheresteramides containing polyamide blocks, formed by the condensation of caprolactam in the presence of the sodium salt of 3-sulphoisophthalic acid, and polyether blocks which are adducts of ethylene oxide with bisphenol A. There is no description of blocks consisting of copolyamide or of polyamide oligomers of low molecular masses.
Patent EP 613 919 discloses polyetheresteramides containing polyether blocks which are adducts of ethylene oxide with bisphenol A. The chain limiter for the polyamide blocks is a dicarboxylic acid; mention is made of diacids bearing a sulphonate group, such as the sodium salt of 3-sulphoisophthalic acid, and unsubstituted diacids such as terephthalic acid, isophthalic acid, sebacic acid, adipic acid and decanedicarboxylic acid. None of the examples uses diacids bearing sulphonate groups. Furthermore, the specific advantage provided by the incorporation of ionic groups, such as the sulphonate groups, into the polyetheresteramide chain to improve the antistatic properties is not described. As shown in the said patent, the use of a bisphenol-A adduct plays a heat-stabilizing role. On the other hand, the intrinsic antistatic properties of the product are not improved. The polyamide blocks disclosed in the examples consist of caprolactam; copolyamides are not described. These polyetheresteramides are added to various thermoplastic polymers to make them antistatic, but it is also necessary to add salts chosen from alkali metal halides or alkaline-earth metal halides.
According to a first form of the invention, the Applicant has now found novel polyetheresteramides containing polyamide blocks comprising dicarboxylic acid sulphonates, either as polyamide-block chain limiters or combined with a diamine as one of the constituent monomers of the polyamide block. The polyether blocks consist essentially of alkylene oxide units, preferably ethylene oxide units, but do not comprise aromatic diols, i.e. it is advantageously polyethylene glycol. These polyetheresteramides of very simple structure have very good antistatic properties as well as good heat stability.
According to a second form of the invention, the Applicant has found novel polyetheresteramides containing polyamide blocks of the polyamide oligomer type of low molecular masses, or of the copolyamide type which comprise dicarboxylic acid sulphonates and whose polyether blocks are adducts of alkylene oxide, preferably ethylene oxide, with an aromatic diol. This combination is particularly advantageous for improving the thermal behaviour.
According to a third form of the invention, the Applicant has found that the polyetheresteramides of the first and second forms of the invention are particularly useful for making a thermoplastic polymer (A) antistatic.
BRIEF DESCRIPTION OF THE INVENTION
According to a first form, the present invention relates to polyetheresteramides (B) containing polyamide blocks comprising dicarboxylic acid sulphonates either as chain limiters for the polyamide block or combined with a diamine as one of the constituent monomers of the polyamide block, and containing polyether blocks consisting essentially of alkylene oxide units.
According to a second form, the present invention relates to polyetheresteramides (B) containing polyamide blocks of the polyamide oligomer type of low molecular masses, or of the copolyamide type comprising dicarboxylic acid sulphonates, and containing polyether blocks which are adducts of alkylene oxide with an aromatic diol.
According to a third form, the present invention relates to antistatic or breathable polymer compositions comprising a thermoplastic polymer (A) and at least one polyetheresteramide (B) according to one of the above forms.
DETAILED DESCRIPTION OF THE INVENTION
The dicarboxylic acid sulphonates are ammonium or alkali metal salts of aromatic diacids. They are, for example, sodium, potassium, lithium and ammonium salts of 2-sulphoisophthalic acid, 4-sulphoisophthalic acid, 5-sulphoisophthalic acid (3-sulphoisophthalic acid), 2-sulphoterephthalic acid, 2,6-dicarboxynaphthalene-4-sulphonic acid, 2,7-dicarboxynaphthalene-4-sulphonic acid and diphenylsulphoterephthalic acid and/or alkyl esters thereof.
Briffaud Thierry
Hilgers Hermann
Lacroix Christophe
Linemann Reinhard
Atofina
Boykin Terressa
Millen, White, Zelano & Brangian, P.C.
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