Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
2002-06-24
2003-11-18
Sanders, Kriellion A. (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C524S101000, C524S405000, C524S414000, C524S418000, C524S424000, C524S432000
Reexamination Certificate
active
06649674
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to flame-proof polyester molding compositions and more particularly to thin-walled moldings made therefrom.
SUMMARY OF THE INVENTION
A flame-proofed polyester molding composition is disclosed. The composition that exhibits good flame-resistance, particularly in thin-walled moldings, contains red phosphorus, nitrogen-containing compounds and a small amount of a hydrotalcite. The composition is particularly suitable for the preparation of moldings, sheeting and fibers.
BACKGROUND OF THE INVENTION
Polyester molding compositions which are rendered flame-proof are of considerable importance in the electrical/electronics field and are used for the production of supports for voltage-carrying parts, for example. Apart from good flame-resistance, these compositions also have to have good mechanical and electrical properties. In addition, halogen-free molding compositions, particularly ones that are free of halogenated flame retarding agents, are increasingly being required.
There has been a series of developments in this field.
Thus JP-A 06-157880 describes molding compositions comprising polyethylene terephthalate which are made flame-resistant by melamine cyanurate and organophosphates and which exhibit good corrosion behavior in addition to good smoke fume properties.
Flame-proof polyester molding compositions are known from JP-A 11-140290 which contain fluorine compounds in addition to organophosphates and melamine cyanurate.
WO 98/30632 discloses flame-resistant thermoplastic polyesters which contain coated red phosphorus and a phenolic novolac resin.
WO 99/27016 describes red phosphorus in combination with an additional phosphorus compound and a fluoropolymer for the flame-proofing of mixtures of polybutylene terephthalate and polycarbonate.
JP-A 11-335531 relates to molding compositions comprising polybutylene and polyethylene terephthalate which in addition to coated red phosphorus contain triazine compounds and cyanuric acid compounds and a polyolefine, and which are suitable for use in the electrical/electronics field.
Nevertheless, no satisfactory degree of success has hitherto been achieved in formulating polybutylene terephthalate in particular, without the admixture of less flammable polymers such as polycarbonate, with halogen-free flame-retardants such that good flame-resistance is achieved, especially for thin-walled applications/-moldings.
DETAILED DESCRIPTION OF THE INVENTION
Surprisingly, it has now been found that the flame-resistance of polyester molding compositions, particularly polybutylene terephthalate, which comprise red phosphorus and melamine cyanurate, may be considerably improved by the addition of small amounts of a hydrotalcite, particularly in thin-walled components and moldings. Moreover, the molding compositions according to the invention exhibit an outstanding resistance in the glowing wire test.
The present invention thus relates to molding compositions containing:
A) one or more polyester, polyester carbonate or polycarbonate
B) 5 to 30 parts by weight, preferably 10 to 20 parts by weight, most preferably 14 to 20 parts by weight, of a flame retardant containing
b1) 16 to 50% by weight, preferably 28.5 to 50% by weight, most preferably 33 to 50% by weight (with respect to B) of red phosphorus, and
b2) 50 to 84% by weight, preferably 50 to 71.5% by weight, most preferably 50 to 67% by weight (with respect to B) of a nitrogen compound,
C) 0.001 to 0.69 parts by weigh, preferably 0.05 to 0.50 parts by weight, of a hydrotalcite, as well as
D) 1 to 50 parts by weight, preferably 10 to 40 parts by weight, most preferably 10 to 35 parts by weight, of fillers and/or reinforcing agents,
E) 0 to 50 parts by weight, preferably 0.001 to 40 parts by weight, most preferably 0.001 to 25 parts by weight, of other conventional functional additives,
wherein the sum of the proportions of A to E is 100 parts by weight.
Polyesters as defined by component A) firstly comprise polyalkylene terephthalates, i.e. reaction products of dicarboxylic acids, preferably aromatic dicarboxylic acids, or reactive derivatives thereof (e.g. dimethyl esters or anhydrides) and aliphatic, cycloaliphatic or araliphatic diols, and mixtures of said reaction products, and secondly comprise completely aromatic polyesters which are described in detail below.
Polyalkylene terephthalates may be produced by known methods from terephthalic acid (or reactive derivatives thereof) and aliphatic or cycloaliphatic diols containing 2 to 10 C atoms (Kunststoff-Handbuch, Volume VIII, pages 695 et seq., Karl-Hanser-Verlag, Munich 1973).
The preferred polyalkylene terephthalates contain at least 80, preferably 90 mol % with respect to the dicarboxylic acid, of terephthalic acid radicals, and at least 80, preferably at least 90 mol % with respect to the diol component, of ethylene glycol and/or 1,3-propanediol and/or butanediol radicals.
In addition to terephthalic acid radicals, the preferred polyalkylene terephthalates may contain up to 20 mol % of radicals of other aromatic dicarboxylic acids containing 8 to 14 C atoms, or of aliphatic dicarboxylic acids containing 4 to 12 C atoms, such as radicals of phthalic acid, isophthalic acid, naphthalene-2,6-dicar-boxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid or cyclohexane-diacetic acid.
Apart from ethylene or 1,3-propanediol or 1,4-butanediol radicals, the preferred polyalkylene terephthalates may contain up to 20 mol % of other aliphatic diols comprising 3 to 12 C atoms or cycloaliphatic diols comprising 6 to 21 C atoms, e.g. radicals of 1,3-propanediol, 2-ethylpropanediol-1,3, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, cyclohexane-dimethanol-1,4, 3-methylpentanediol-2,4, 2-methylpentanediol-2,4, 2,2,4-trimethylpentanediol-1,3 and 1,6,2-ethylhexanediol-1,3, 2,2-diethylpropanediol-1,3, 2,5-hexanediol, 1,4-di-(&bgr;-hydroxyethoxy)-benzene, 2,2-bis-(4-hydroxycyelohexyl)-propane, 2,4-dihydroxy-1,1,3,3-tetramethyl-cyclobutane, 2,2-bis-(3-&bgr;-hydroxyethoxyphenyl)propane and 2,2-bis-(4-hydroxypropoxy-phenyl)-propane (DE-A 24 07 674, 24 07 776, 27 15 932).
The polyalkylene terephthalates may be branched by the incorporation of relatively small amounts of trihydric or tetrahydric alcohols or of tri- or tetrabasic carboxylic acids, such as those described in DE-A 19 00 270 and U.S. Pat. No. 3,692,744, incorporated herein by reference for example. Examples of preferred branching agents include trimesic acid, trimellitic acid, trimethylol-ethane and -propane, and pentaerythritol.
It is advisable to use not more than 1 mol % of the branching agent with respect to the acid component.
Particularly preferred polyalkylene terephthalates are those which are produced solely from terephthalic acid and reactive derivatives thereof, (e.g. dialkyl esters thereof) and ethylene glycol and/or 1,3-propanediol and/or 1,4-butanediol (polyethylene-, polypropylene- and polybutylene terephthalates), as well as mixtures of these polyalkylene terephthalates. Within the scope of the present invention, the use of mixtures of polybutylene- and polyethylene terephthalates is quite particularly preferred.
The preferred polyalkylene terephthalates also include copolyesters which are produced from at least two of the aforementioned acid components and/or from at least two of the aforementioned alcohol components; the most preferred copolyesters are poly(ethylene glycol/1,4-butanediol) terephthalates.
The polyalkylene terephthalates generally have an intrinsic viscosity of about 0.4 to 1.5, preferably 0.5 to 1.3, as measured in phenol/o-dichlorobenzene (1:1 parts by weight) at 25° C.
The completely aromatic polyesters which are also suitable are the reaction products of aromatic dicarboxylic acids or reactive derivatives thereof with corresponding aromatic dihydroxy compounds.
The compounds discussed above in the description of the polyalkylene terephthalates may be used as aromatic dicarboxylic acids. Mixtures of 5 to 100 mol % isophthalic acid and 0 to 95 mol % terephthalic acid, particularly mixtures ranging from about 8
Peerlings Henricus
Wagner Michael
Bayer Aktiengesellschaft
Gil Joseph C.
Preis Aron
Sanders Kriellion A.
LandOfFree
Flame-proof polyester molding compositions comprising... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Flame-proof polyester molding compositions comprising..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Flame-proof polyester molding compositions comprising... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3170368