Patent Application
20090062436
The invention relates to flame retardant compositions comprising at least one salt of an aromatic phosphoric acid ester and polycarbonates and to a process for imparting flame retardancy to a polymer substrate comprising polycarbonates and at least one salt of an aromatic phosphoric acid ester.
Polycarbonates are thermoplastic polymers of high toughness, outstanding transparency, excellent compatibility with several polymers, and high heat distortion resistance. Polycarbonates correspond to the general formula
The economically most important polycarbonate is 2,2-bis(4-hydroxyphenyl)propane polycarbonate (1), also termed bisphenol A polycarbonate [24936-68-3] (BPA-PC):
cf. Ullmann's Encyclopaedia of Industrial Chemistry, On-Line Edition, Wiley-VCH, DOI: 10.1002/14356007.a—207, and entry Polycarbonate, Roempp On-line, www.roempp.com.
Various additives for improving the mechanical, chemical and thermal properties of polycarbonates are known. Fluorocarbon terminated poly-carbonates are useful for various technical applications, such as reducers of surface energy, “surface modifiers”, for organic materials, preferably polycarbonates, polyesters, polyacrylates or polymethacrylates or their mixtures, blends or alloys. Polymers with such a reduced surface energy possess desirable properties, such as “easy to clean”, “self-cleaning”, “antisoiling”, “soil-release”, “antigraffiti”, “oil resistance”, “solvent resistance”, “chemical resistance”, “self lubricating”, “scratch resistance”, “low moisture absorption” and “hydrophobic” surface. The preparation of particularly useful fluorocarbon terminated polycarbonates is described in the International Patent Application No. PCT/EP2004/053331.
Flame retardants are added to polymeric materials (synthetic or natural) to enhance the flame retardant properties of the polymers. Depending on their composition, flame retardants may act in the solid, liquid or gas phase either chemically, e.g. as a spumescent by liberation of nitrogen, and/or physically, e.g. by producing a foam coverage. Flame retardants interfere during a particular stage of the combustion process, e.g. during heating, decomposition, ignition or flame spread.
The addition of flame retardants to polycarbonates is known, cf. J. Troitzsch, Plastics Flammability Handbook, 3rd edition, Hanser Publishers, Munich 2004, pp. 158-172 (ISBN 3-446-21308-2).
The addition of phosphate esters to polycarbonate flame retardant compositions is known, cf. U.S. Pat. No. 6,756,433.
In applications where a sample thickness smaller or equal than 1.6 mm is required, a flame retardancy of V-0, according to UL-94 (Underwriter's Laboratories Subject 94), is obtained by the addition of a so-called anti-dripping agent, such as polytetrafluoroethylene. The addition of aromatic phosphoric ester salts to polycarbonate flame retardant compositions containing tetrafluoroethylene polymers has been described in U.S. Pat. No. 4,649,168. Other co-additives for flame retardants have been proposed, such as haloarylphosphates, cf. U.S. Pat. No. 5,478,874 or guanidine salts; cf. U.S. Pat. No. 6,518,340.
The addition of polysiloxanes of different structures has been proposed in various references; cf. U.S. Pat. Nos. 6,660,787, 6,727,302 or 6,730,720. A problem of these additives is seen in the fact that the concentration of the flame retardant must be increased to arrive at the V-0 classification, which is detrimental to the mechanical, chemical and thermal properties of polycarbonates.
Therefore, the present invention relates to finding suitable additives, which are applicable in low concentrations as flame retardants in polycarbonates. It has surprisingly been found that salts of selected aromatic phosphoric acid esters, which are applicable as so-called nucleating agents, are particularly suitable as flame retardant additives, even at low concentrations. Nucleating agents are polymer additives that control the crystallization properties of crystalline polymers by increasing the crystallization temperature and/or accelerating the crystallization rate and/or decreasing the spherulite diameter and narrowing the size distribution.
Like other flame retardants of first choice, the salts of selected aromatic phosphoric acid esters are present in small quantities in the polycarbonates and, but due to the low dosing levels, have no significant negative effect on polymer mechanics and other properties.
The present invention relates to a composition, particularly a flame retardant composition, which comprises
a) At least one salt of an aromatic phosphoric acid ester of the formula
b) A polymer substrate comprising polycarbonate or polycarbonate blends.
A preferred embodiment of the invention relates to a composition, particularly a flame retardant composition, which comprises as component a) at least one salt of an aromatic phosphoric acid ester (I), wherein
One of R1 and R2 represents phenyl or phenyl substituted by one or two C1-C4alkyl; and the other one represents C1-C4alkyl; or
R1 and R2 both represent phenyl or phenyl substituted by one or two C1-C4alkyl; or
R1 and R2 together represent the group (A), wherein
X represents C1-C4alkylene;
One of R1 and R2 represents hydrogen, methyl or tert-butyl and the other one represents tert-butyl; and
R1′ and R2′ are as defined as R1 and R2; and
n represents 1;
Mn+ represents a cation that bears one positive charge.
A particularly preferred embodiment relates to a composition, particularly a flame retardant composition, which comprises as component a) at least one salt of an aromatic phosphoric acid ester of the formula
X represents C1-C4alkylene;
One of R1 and R2 represents hydrogen, methyl or tert-butyl and the other one represents tert-butyl; and
R1′ and R2′ are as defined as R1 and R2; and
M+ represents a cation that bears one positive charge.
A highly preferred embodiment relates to a composition, particularly a flame retardant composition, which comprises as component a) at least one salt of an aromatic phosphoric acid ester (I′), wherein
X represents methylene;
One of R1 and R2 represents methyl or tert-butyl and the other one represents tert-butyl; and
R1′ and R2′ are as defined as R1 and R2; and
Mn+ represents a cation that bears one positive charge.
Highest preference is given to a composition which comprises as component a) at least one salt of an aromatic phosphoric acid ester (I′), wherein
X represents methylene;
R1 and R2 and R1′ and R2′ represent tert-butyl; and
Mn+ represents sodium or potassium.
The compositions according to the invention attain the desirable V-0 rating, according to UL-94 (Underwriter's Laboratories Subject 94) and other excellent ratings in related test methods while preserving the excellent mechanical, chemical and thermal properties of polycarbonates.
The composition, as defined above, comprises the following components:
The term salt of an aromatic phosphoric acid ester comprises within its scope preferably a metal salt, for example an alkali metal (n=1) or alkaline earth metal salt (n=2), e.g. the sodium, potassium, calcium salt.
According to an alternative embodiment, the term salts comprises non-metallic salts (n=1), e.g. the ammonium, (C1-C22alkyl)1-4ammonium or (2-hydroxyethyl)1-4ammonium, e.g. tetramethylammonium, tetraethylammonium or the 2-hydroxyethyltrimethylammonium salt.
Therefore the definition of the cation Mn+ in the formula above comprises within its scope an alkali metal atom, e.g. the sodium or potassium ion, the ammonium ion or a cation formed from an amine, e.g. (C1-C22alkyl)1-4ammonium or (2-hydroxyethyl)1-4ammonium, e.g. the tetramethylammonium, tetraethylammonium or the 2-hydroxyethyltrimethylammonium ions. In the aromatic phosphoric acid ester (I) C1-C8alkyl is present in R1 and R2 and, correspondingly in R1′ and R2′, is preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl.
Compounds (1) are exemplified by the following structural formulae:
Wherein Ra represents hydrogen or C1-C8alkyl, Rb represents C1-C8alkyl and Ra′ and Rb′ are as defined as Ra and Rb, n represents 1 or 2, preferably 1, and Mn+ represents a cation that bears one positive charge if n represents 1 or a cation that bears two positive charges if n represents 2;
Wherein R represents C1-C8alkyl, Ra represents hydrogen or C1-C8alkyl, Rb represents C1-C8alkyl, n represents 1 or 2, preferably 1, and Mn+ represents a cation that bears one positive charge if n represents 1 or a cation that bears two positive charges if n represents 2;
One of R1 and R2 represents hydrogen, methyl or tert-butyl and the other one represents tert-butyl; and
R1′ and R2′ are as defined as R1 and R2; and
M+ represents a cation that bears one positive charge, e.g. the sodium or potassium ion;
Particularly the compound:
The aromatic phosphoric acid esters and their salts are known compounds. They are available by known methods. The preparation of aromatic phosphoric esters of the formula I′ is described in the published European Patent Application No. 1 209 190.
The polymer substrate comprising polycarbonates or polycarbonate blends may be of any grade and prepared by any known method. The term polymer substrate comprises within its scope any polycarbonate homopolymers or copolymers thereof, such as copolymers with polyesters.
Polycarbonates are thermoplastic polymers that correspond to the general formula:
Polycarbonates are obtainable by interfacial processes or by melt processes (catalytic transesterification). The polycarbonate may be either branched or linear in structure and may include any functional substituents. Polycarbonate copolymers and polycarbonate blends are also within the scope of the invention. The term polycarbonate should be interpreted as inclusive of copolymers and blends with other thermoplastics. Methods for the manufacture of polycarbonates are known, for example, from U.S. Pat. Nos. 3,030,331; 3,169,121; 4,130,458; 4,263,201; 4,286,083; 4,552,704; 5,210,268; and 5,606,007. A combination of two or more polycarbonates of different molecular weights may be used.
Preferred are polycarbonates obtainable by reaction of a diphenol, such as bisphenol A, with a carbonate source. Examples of suitable diphenols are:
The carbonate source may be either a carbonyl halide, a carbonate ester or a haloformate. Suitable carbonate halides are phosgene or carbonylbromide. Suitable carbonate esters are dialkylcarbonates, such as dimethyl- or diethylcarbonate, diphenyl carbonate, phenyl-alkyl-phenylcarbonate, such as phenyl-tolylcarbonate, dialkylcarbonates, such as dimethyl- or diethylcarbonate, di-(halophenyl)carbonates, such as di-(chlorophenyl)carbonate, di-(bromophenyl)carbonate, di-(trichlorophenyl)carbonate or di-(trichlorophenyl)carbonate, di-(alkylphenyl)carbonates, such as di-tolylcarbonate, naphthylcarbonate, dichloronaphthylcarbonate and others.
Other process details, such as the addition of molecular weight regulators, acid acceptors, catalysts are disclosed in the references mentioned above.
According to an additional embodiment, the polymer substrate comprising polycarbonates or polycarbonate blends is a polycarbonate-copolymer, wherein isophthalate/terephthalate-resorcinol segments are present. Such polycarbonates are commercially available, e.g. Lexan® SLX (General Electrics Co. USA). Other polymeric substrates of component b) may additionally contain in the form as admixtures or as copolymers a wide variety of synthetic polymers including polyolefins, polystyrenes, polyesters, polyethers, polyamides, poly(meth)acrylates, thermoplastic polyurethanes, polysulphones, polyacetals and PVC, including suitable compatibilizing agents. For example, the polymer substrate may additionally contain thermoplastic polymers selected from the group of resins consisting of polyolefins, thermoplastic polyurethanes, styrene polymers and copolymers thereof. Specific embodiments include polypropylene (PP), polyethylene (PE), polyamide (PA), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), glycol-modified polycyclohexylenemethylene terephthalate (PCTG), polysulphone (PSU), polymethylmethacrylate (PMMA), thermoplastic polyurethane (TPU), acrylonitrile-butadiene-styrene (ABS), acrylonitrile-styrene-acrylic ester (ASA), acrylonitrile-ethylene-propylene-styrene (AES), styrene-maleic anhydride (SMA) or high impact polystyrene (HIPS).
A list of suitable synthetic polymers is given below:
Component a) is added to the substrate of component b) in an amount of about 0.001 to 5.0 weight %, preferably 0.01 to 2.0 weight % and most preferably 0.04 to 0.5 weight %.
A further embodiment of the invention relates to a process for imparting flame retardancy to a polymer substrate comprising polycarbonates or polycarbonate blends, which process comprises adding to said polymer substrate at least one salt of an aromatic phosphoric acid ester of the formula (I) as defined above.
The instant invention further pertains to a composition, which comprises, in addition to the components a) and b), as defined above, further additives selected from the group consisting of so-called anti-dripping agents, polymer stabilizers and additional flame-retardants, such as phosphorus containing flame-retardants, nitrogen containing flame-retardants, halogenated flame-retardants and inorganic flame-retardants.
According to a preferred embodiment, the invention relates to a composition which additionally comprises as additional component so-called anti-dripping agents.
These anti-dripping agents reduce the melt flow of the polycarbonate composition and inhibit the formation of drops at high temperatures. Various references, such as U.S. Pat. No. 4,263,201, describe the addition of anti-dripping agents to polycarbonate flame retardant compositions.
Suitable additives that inhibit the formation of drops at high temperatures include glass fibers, polytetrafluoroethylene (PTFE), high temperature elastomers, carbon fibers, glass spheres and the like.
The addition of polysiloxanes of different structures has been proposed in various references; cf. U.S. Pat. Nos. 6,660,787, 6,727,302 or 6,730,720.
According to a specific embodiment of the invention a (poly)carbonate compound of the formula
R1 and R2 independently of one another represent an aliphatic group substituted by fluorine;
X1 and X2 independently of one another represent the direct bond or C1-C12alkylene;
m represents a numeral from 1 to 1000;
R5, R6, R7 and R8 independently of one another represent hydrogen, C1-C12alkyl or C3-C12alkenyl; and
Y represents the direct bond or a bivalent group selected from the group consisting of —O—, —S—, —SO—, —SO2—,
Both Ra and Rb represent hydrogen or halogen; or
One of Ra and Rb represents hydrogen and the other one represents halogen;
R3 and R4, together with the carbon atom to which they are bonded, form a C5-C8-cycloalkylidene group with 1 to 3 C1-C4alkyl groups as optional substituents; or
R3 and R4 independently of one another represent hydrogen, an aliphatic group substituted by fluorine, C1-C12alkyl, C1-C12alkyl substituted by carboxy, C2-C12alkenyl, aryl, or the group of the partial formula
n represents a numeral from 0-10 000; and
X2, Y, R2, R5, R6, R7 and R8 are as defined above.
In the (poly)carbonate compound (1), as defined above, the substituents are defined as follows:
R1 and R2 independently of one another represent an aliphatic group substituted by fluorine;
X1 and X2 independently of one another represent the direct bond or C1-C12alkylene;
m represents a numeral from 1 to 1000;
R5, R6, R7 and R8 independently of one another represent hydrogen, C1-C12alkyl or C3-C12alkenyl; and
Y represents the direct bond or a bivalent group selected from the group consisting of —O—, —S—, —SO—, —SO2—, wherein
Both Ra and Rb represent hydrogen or halogen; or
One of Ra and Rb represents hydrogen and the other one represents halogen;
R3 and R4, together with the carbon atom to which they are bonded, form a C5-C8-cycloalkylidene group with 1 to 3 C1-C4alkyl groups as optional substituents; or
R3 and R4 independently of one another represent hydrogen, an aliphatic group substituted by fluorine, C1-C12alkyl, C1-C12alkyl substituted by carboxy, C2-C12alkenyl, aryl, or the group (A), as defined above, wherein n represents a numeral from 0-10 000 and X2, Y, R2, R5, R6, R7 and R8 are as defined above.
R1 and R2 defined as an aliphatic group substituted by fluorine is preferably a straight chain or branched hydrocarbon group, which contains at least one fluoro atom, for example fluoro-C1-C25alkyl, or is a perfluoroalkyl group of the partial formula
—(CF2)pF (B),
wherein p is a numeral from 1 to 100.
Fluoro-C1-C25alkyl is for example, mono-, difluoromethyl, 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl, 5-fluoropentyl, 6-fluorohexyl, 7-fluoroheptyl or pentafluorobutyl.
Perfluoroalkyl is a group (B) derived from the perfluoro alcohol F(CF2)p—OH wherein p is 1 to 50, for example trifluoromethyl (p=1) or pentafluoroethyl (p=2). Preferred perfluoroalkyl groups are derived form perfluoro alcohols wherein p is 5, 8, 9 or 11.
X1 and X2 defined as C1-C12alkylene is a branched or unbranched bivalent group, for example methylene, ethylene, propylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, decam ethylene or dodecam ethylene. One of the preferred definitions for X1 and X2 is C1-C8alkylene, for example C2-C8alkylene. An especially preferred definition for X1 and X2 is C2-C4alkylene, for example ethylene.
R5, R6, R7 and R8 defined as C1-C12alkyl is a straight chain or, where possible, branched radical, for example methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, 2-ethylbutyl, n-pentyl, isopentyl, 1-methylpentyl, 1,3-dimethylbutyl, n-hexyl, 1-methylhexyl, n-heptyl, isoheptyl, 1,1,3,3-tetramethylbutyl, 1-methylheptyl, 3-methylheptyl, n-octyl, 2-ethylhexyl, 1,1,3-trimethylhexyl, 1,1,3,3-tetramethylpentyl, n-nonyl, n-decyl, n-undecyl, 1-methylundecyl or n-dodecyl. One of the preferred definitions is, for example, C1-C8alkyl, for example C1-C4alkyl, such as methyl.
R5, R6, R7 and R8 defined as C3-C12alkenyl is a straight chain or, where possible, branched radical, for example allyl, 2-butenyl, 3-butenyl, isobutenyl, n-2,4-pentadienyl, 3-methyl-2-butenyl, n-2-octenyl, n-2-dodecenyl or iso-dodecenyl.
Y defined as a bivalent group of the partial formula
is preferably methylene (CH2═, Ra and Rb═H). According to alternative embodiments, both Ra and Rb represent hydrogen or halogen, for example chlorine or bromine, or one of Ra and Rb represents hydrogen and the other one represents halogen.
R3 and R4 defined as a C5-C8-cycloalkylidene group with 1 to 3 C1-C4alkyl groups as optional substituents is, for example, cyclopentylidene, methylcyclopentylidene, dimethylcyclopentylidene, cyclohexylidene, methylcyclohexylidene, dimethylcyclohexylidene, trimethylcyclohexylidene, tert-butylcyclohexylidene, cycloheptylidene or cyclooctylidene. Preference is given to cyclohexylidene.
R3 and R4 defined as an aliphatic group substituted by fluorine is for example fluoro-C1-C25alkyl, as defined above, or is the above-mentioned perfluoroalkyl group (B), wherein p is 1 to 50.
R3 and R4 defined as C1-C12alkyl is as defined above with regard to R5, R6, R7 and R8.
R3 and R4 defined as C1-C12alkyl substituted by carboxy is, for example, carboxymethyl or 1- or 2-carboxyethyl.
R3 and R4 defined as aryl is preferably phenyl or 1- or 2-naphthyl.
In the group (A) the index n represents a numeral from 0-10 000 and X2, Y, R2, R5, R6, R7 and R8 are as defined above.
Of particular interest are (poly)carbonate compounds (1), wherein
R1 and R2 independently of one another represent an aliphatic group substituted by fluorine;
X1 and X2 independently of one another represent C1-C12alkylene;
m represents a numeral from 1 to 1 000;
R5, R6, R7 and R8 represent hydrogen;
Y represents the bivalent group
wherein independently of one another R3 and R4 represent hydrogen, —CF3, C1-C12alkyl, phenyl or the group (A), wherein n represents a numeral from 0 to 10 000 and X2, Y, R2, R5, R6, R7 and R8 are as defined above or R3 and R4, together with the carbon atom to which they are bonded, form the cyclohexylidene group with 1 to 3 C1-C4alkyl groups as optional substituents.
Of particular interest are also (poly)carbonate compounds (1), wherein R1 and R2 independently of one another represent groups (B), wherein p is a numeral from 1 to 50.
Of special interest are (poly)carbonate compounds (1), wherein p is a numeral from 4 to 15.
Of very special interest are (poly)carbonate compounds (1), wherein
R1 and R2 independently of one another represent groups (B), wherein p is a numeral from 1 to 50;
X1 and X2 independently of one another represent C2-C8alkylene;
m represents a numeral from 1 to 1 000;
R5, R6, R7 and R8 represent hydrogen; and
Y represents the bivalent group
wherein
R3 represents hydrogen, —CF3, C1-C12alkyl, phenyl or the group (A), wherein the numeral n represents a numeral from 0 to 10 000 and X2, Y, R2, R5, R6, R7 and R8 are as defined above or R3 and R4, together with the carbon atom to which they are bonded, form the cyclohexylidene group with 1 to 3 C1-C4alkyl groups as optional substituents.
Of high interest are (poly)carbonate compounds (1), wherein R3 and R4 independently of one another represent hydrogen or C1-C4alkyl; or R3 and R4, together with the carbon atom to which they are bonded, form the cyclohexylidene group.
Particularly preferred are also (poly)carbonate compounds (1), wherein m is a numeral from 1 to 50, and n is a numeral from 0 to 50.
The (poly)carbonate compounds (1) are prepared by known methods. A fluoro alcohol is treated with bis(2,4-dinitrophenyl)carbonate (DNPC) to give the 2,4-dinitrophenyl carbonate of the fluoro alcohol in situ. This derivative can be isolated and treated separately, for example by hydroxy terminated bisphenol A oligomers of various molecular weights.
Brunelle et al., Macromolecules 1991, 24, 3035-3044, discloses the use of bis(2,4-dinitrophenyl)carbonate for preparation of dimer and cyclic oligomers of bisphenol A. The coupling reactions can also be carried out by carbonate linkage forming reagents, such as phosgene or carbonyl diimidazole (CDI).
Preferred fluoro alcohols are, for example, so-called fluorotelomer alcohols. These are, for example, commercially available from DuPont or Aldrich as Zonyl® BA-L.
Preferred bisphenol starting materials are, for example, bisphenol A and the compounds of the formulae:
According to an alternative embodiment a (poly)carbonate compound of the formula
is added, wherein
R0 represents the direct bond or a bivalent group selected from the group consisting of
R1 and R2 independently of one another represent a silicon containing group;
R3 and R4 independently of one another represent hydrogen, an aliphatic group substituted by fluorine, a silicon containing group, C1-C12alkyl, C1-C12alkyl substituted by carboxy, C2-C12alkenyl, aryl, or a group of the partial formula
or R3 and R4, together with the carbon atom to which they are bonded represent C5-C8-cycloalkylidene or C5-C8-cycloalkylidene that is substituted by from 1 to 3 C1-C4alkyl groups;
R5, R6, R7 and R8 independently of one another represent hydrogen, C1-C12alkyl or C3-C12alkenyl;
X1 and X2 independently of one another represent the direct bond, C1-C12alkylene or C4-C25alkylene interrupted by —O—;
Y1 and Y2 independently of one another represent the direct bond or a bivalent group selected from the group consisting of
R9 and R10 independently of one another represent the direct bond or C1-C4alkylene;
R11, R12 and R13 independently of one another represent hydrogen, C1-C12alkyl or C3-C12alkenyl;
R14 represents hydrogen, C1-C12alkyl or a silicon containing group,
m represents a numeral from 0 to 10 000; and
n represents a numeral from 0 to 10 000.
In the (poly)carbonate compound (2), as defined above, the substituents are defined as follows:
R0 represents the direct bond or a bivalent group selected from the group consisting of
R1 and R2 independently of one another represent a silicon containing group;
R3 and R4 independently of one another represent hydrogen, an aliphatic group substituted by fluorine, a silicon containing group, C1-C12alkyl, C1-C12alkyl substituted by carboxy, C2-C12alkenyl, aryl, or a group of the partial formula
or R3 and R4, together with the carbon atom to which they are bonded represent C5-C8-cycloalkylidene or C5-C8-cycloalkylidene that is substituted by 1 to 3 C1-C4alkyl groups;
R5, R6, R7 and R8 independently of one another represent hydrogen, C1-C12alkyl or C3-C12alkenyl;
X1 and X2 independently of one another represent the direct bond, C1-C12alkylene or C4-C25alkylene interrupted by —O—;
Y1 and Y2 independently of one another represent the direct bond or a bivalent group selected from the group consisting of
R9 and R10 independently of one another represent the direct bond or C1-C4alkylene;
R11, R12 and R13 independently of one another represent hydrogen, C1-C12alkyl or C3-C12alkenyl;
R14 represents hydrogen, C1-C12alkyl or a silicon containing group;
m represents a numeral from 0 to 10 000; and
n represents a numeral from 0 to 10 000.
A silicon containing group preferably represents a group of the partial formula
wherein
R17, R18, R19 and R20 independently of one another represent C1-C12alkyl, C1-C12alkyl substituted with hydroxy or amino; hydroxyC4-C12alkyl interrupted with —O—; or represents a group of the partial formula
wherein
R21 represents C1-C12alkyl or a group of the partial formula
R22, R23, R24, R25, R26, R27, R28 and R29 independently of one another represent C1-C12alkyl or C1-C12-alkyl substituted with hydroxy or amino;
p represents 0 to 200; and
q represent 0 to 200.
Of special interest as a silicon containing group is a group of the partial formula (D), wherein
R17, R18, R19 and R20 independently of one another represent methyl or a group of the partial formula
R21 represents methyl or a group of the partial formula
R22, R23, R24, R25, R26, R27, R28 and R29 are methyl; and
p and q independently of one another represent 0 to 100.
Of particular interest are (poly)carbonate compounds (2), wherein
R0 represents the bivalent group
R1 and R2 independently of one another represent a silicon containing group;
R3 and R4 independently of one another represent hydrogen, trifluoromethyl, a silicon containing group, C1-C12alkyl, phenyl or the group (C); or
R3 and R4, together with the carbon atom to which they are bonded represent C5-C8-cycloalkylidene or C5-C8-cycloalkylidene that is substituted by 1 to 3 C1-C4alkyl groups;
R5, R6, R7 and R8 are hydrogen;
X1 and X2 independently of one another represent C1-C12alkylene or C4-C25alkylene interrupted by —O—;
Y1 and Y2 independently of one another represent the direct bond or a bivalent group selected from the group consisting of
R9 and R10 independently of one another represent the direct bond or methylene;
R11, R12 and R13 independently of one another represent hydrogen, C1-C4alkyl or C3-C4alkenyl;
R14 represents hydrogen or C1-C12alkyl;
m represents 0 to 10 000; and
n represents 0 to 10 000.
Of very special interest are (poly)carbonate compounds (2), wherein
R0 represents the bivalent group
R3 represents hydrogen, —CF3, C1-C12alkyl, phenyl or the group (C);
R4 represents —CF3, C1-C12alkyl or phenyl; or
R3 and R4, together with the carbon atom to which they are bonded, form a C5-C8-cycloalkylidene group or C5-C8-cycloalkylidene that is substituted by 1 to 3 C1-C4alkyl groups;
R5, R6, R7 and R8 represent hydrogen;
X1 and X2 are each independently of the one another represent C1-C12alkylene or C4-C25alkylene interrupted by —O—;
Y1 and Y2 independently of one another represent the direct bond or a bivalent group selected from the group consisting of
R9 and R10 independently of one another represent the direct bond or methylene;
R14 represents hydrogen or C1-C12alkyl;
m represents 0 to 10 000; and
n represents 0 to 10 000.
Of interest are also (poly)carbonate compounds (2), wherein
R3 and R4 independently of one another represent hydrogen or C1-C4alkyl; or
R3 and R4, together with the carbon atom to which they are bonded, form the cyclohexylidene group.
Preferred are (poly)carbonate compounds (2), wherein X1 and X2 independently of one another represent C2-C8alkylene or C4-C25alkylene interrupted with —O—.
Also preferred are (poly)carbonate compounds (2), wherein m represents 0 to 100, and n represents 0 to 100.
Of very special interest are (poly)carbonate compounds (2), wherein
R0 represents the bivalent group
R3 and R4 independently of one another represent C1-C4alkyl; or
R3 and R4, together with the carbon atom to which they are bonded, form the cyclohexylidene group;
R5, R6, R7 and R8 represent hydrogen;
X1 and X2 independently of one another represent C2-C4alkylene or C4-C25alkylene interrupted with —O—;
Y1 and Y2 independently of one another represent the direct bond or a bivalent group selected from the group consisting of
R9 and R10 independently of one another represent the direct bond or methylene;
m represents 0 to 100, and
n represents 0 to 100.
In a (poly)carbonate compound (2) C1-C12alkyl is a straight chain or, where possible, branched alkyl group, which is the same as defined above with regard to (poly)carbonate compounds (1).
R3 and R4 defined as C1-C12alkyl substituted by carboxy is preferably carboxymethyl or 1- or 2-carboxyethyl.
R3 and R4 defined as aryl preferably represent phenyl or phenyl substituted by 1-3 C1-C4alkyl groups, e.g. methyl.
R3, R4, R5, R6, R7 and R8 defined as C2-C12alkenyl represent a straight chain or, where possible, branched alkenyl group, which is the same as defined above with regard to (poly)carbonate compounds (1).
R3 and R4 defined as C5-C8-cycloalkylidene or C5-C8-cycloalkylidene that is substituted by from 1 to 3 C1-C4alkyl groups are as defined above with regard to (poly)carbonate compounds (1).
X1, and X2, defined as C1-C12alkylene and R9 and R10 defined as C1-C4alkylene represent straight chain or, where possible, branched alkylene groups as defined above with regard to (poly)carbonate compounds (1).
X1, and X2, defined as C4-C25alkylene interrupted with —O— is straight chain or, where possible, branched, for example —CH2CH2—O—CH2CH2—, —CH2CH2CH2—O—CH2CH2—, —CH2CH2CH2—O—CH2CH2CH2— or —CH2CH2—O—CH2CH2—O—CH2CH2—.
C1-C12Alkyl substituted with hydroxy or amino is, for example, hydroxymethyl, 1- or 2-hydroxyethyl or aminomethyl, 1- or 2-aminoethyl.
Hydroxy-C4-C12alkyl interrupted with —O— is for example —CH2CH2—O—CH2CH2OH or —CH2CH2—O—CH2CH2—O—CH2CH2OH.
A fluorine containing group is a branched or unbranched radical, which contains at least one fluoro atom, for example fluoro-C1-C25alkyl; or is the group (B), wherein p is 1 to 50.
Fluoro-C1-C25alkyl is for example fluoromethyl, 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl, pentafluorobutyl, 5-fluoropentyl, 6-fluorohexyl, 7-fluoroheptyl, difluoromethyl or pentafluorobutyl.
The group (B), wherein p is 1 to 50, is, for example trifluoromethyl or pentafluoromethyl.
The (poly)carbonate compounds (2) are obtainable by known methods. A silicon alcohol is treated with bis(2,4-dinitrophenyl)carbonate (DNPC) to give the 2,4-dinitrophenyl carbonate of the silicon alcohol in situ. This derivative can be isolated and treated separately, for example by hydroxy terminated bisphenol A oligomers of various molecular weights. Brunelle et al., Macromolecules 1991, 24, 3035-3044, discloses the use of bis(2,4-dinitrophenyl)carbonate for preparation of dimer and cyclic oligomers of bisphenol A. The coupling reactions can also be carried out by carbonate linkage forming reagents, such as phosgene or carbonyl diimidazole (CDI).
Especially preferred silicon containing groups are derived from mono hydroxypolysiloxanes, wherein p=10; polysiloxanes, wherein p=64; polyalkylene oxides modified heptamethyltrisiloxanes; or 3-(polyoxyethylene)propylheptamethyltrisiloxane. Representative structural formulae are shown below:
Preferred bisphenol starting materials are the same as the ones mentioned above with regard to the preparation of the (poly)carbonate compounds (1).
(poly)carbonate compounds (1) or (2) are added to the substrate of component b) in an amount of about 0.01 to 5.0 weight % and preferably 0.25 to 1.0 weight %. The addition of mixtures of (poly)carbonate compounds (1) or (2) is suggested.
According to another embodiment the invention relates to a composition which additionally comprises further additives in selected from the group consisting of polymer stabilizers and additional flame-retardants.
Stabilizers are preferably halogen-free and selected from nitroxyl stabilizers, nitrone stabilizers, amine oxide stabilizers, benzofuranone stabilizers, phosphite and phosphonite stabilizers, quinone methide stabilizers and monoacrylate esters of 2,2′-alkylidenebisphenol stabilizers.
Additional flame-retardants as of present component are known components, items of commerce or can be obtained by known methods.
Representative phosphorus containing flame-retardants, in addition to the ones defined above with regard to component b), are for example:
Tetraphenyl resorcinol diphosphite (FYROLFLEX® RDP, Akzo Nobel), tetrakis(hydroxymethyl)phosphonium sulphide, triphenyl phosphate, diethyl-N,N-bis(2-hydroxyethyl)-aminomethyl phosphonate, hydroxyalkyl esters of phosphorus acids, ammonium polyphosphate (APP) or (HOSTAFLAM® AP750), resorcinol diphosphate oligomer (RDP), phosphazene flame-retardants and ethylenediamine diphosphate (EDAP).
Nitrogen containing flame-retardants are, for example, isocyanurate flame-retardants, such as polyisocyanurate, esters of isocyanuric acid or isocyanurates. Representative examples are hydroxyalkyl isocyanurates, such as tris-(2-hydroxyethyl)isocyanurate, tris(hydroxymethyl)isocyanurate, tris(3-hydroxy-n-proyl)isocyanurate or triglycidyl isocyanurate.
Nitrogen containing flame-retardants include melamine-based flame-retardants. Representative examples are: melamine cyanurate, melamine borate, melamine phosphates, melamine polyphosphate, melamine pyrophosphate, melamine ammonium polyphosphate and melamine ammonium pyrophosphate.
Further examples are: benzoguanamine, tris(hydroxyethyl) isocyanurate, allantoin, glycoluril, melamine cyanurate, melamine phosphate, dimelamine phosphate, melamine pyrophosphate, urea cyanurate, melamine polyphosphate, melamine borate, ammonium polyphosphate, melamine ammonium polyphosphate or melamine ammonium pyrophosphate, a condensation product of melamine from the series melem, melam, melon and/or a higher condensed compound or a reaction product of melamine with phosphoric acid and/or a reaction product of condensation products of melamine with phosphoric acid or a mixture thereof.
Special emphasis should be given to: dimelamine pyrophosphate, melamine polyphosphate, melem polyphosphate, melam polyphosphate, and/or a mixed polysalt of such a type, more especially melamine polyphosphate.
Representative organohalogen flame-retardants are, for example:
Polybrominated diphenyl oxide (DE-60F, Great Lakes Corp.), decabromodiphenyl oxide (DBDPO; SAYTEX® 102E), tris[3-bromo-2,2-bis(bromomethyl)propyl]phosphate (PB 370®, FMC Corp.), tris(2,3-dibromopropyl)phosphate, tris(2,3-dichloropropyl)phosphate, chlorendic acid, tetrachlorophthalic acid, tetrabromophthalic acid, poly-p3-chloroethyl triphosphonate mixture, tetrabromobisphenol A bis(2,3-dibromopropyl ether) (PE68), brominated epoxy resin, ethylene-bis(tetrabromophthalimide) (SAYTEX® BT-93), bis(hexachlorocyclopentadieno)cyclooctane (DECLORANE PLUS®), chlorinated paraffins, octabromodiphenyl ether, hexachlorocyclopentadiene derivatives, 1,2-bis(tribromophenoxy)ethane (FF680), tetrabromobisphenol A (SAYTEX® RB100), ethylene bis-(dibromo-norbornanedicarboximide) (SAYTEX® BN-451), bis-(hexachlorocycloentadeno) cyclooctane, PTFE, tris-(2,3-dibromopropyl)-isocyanurate, and ethylene-bis-tetrabromophthalimide.
The flame-retardant mentioned above routinely combined with an inorganic oxide synergist. Most common for this use are zinc or antimony oxides, e.g. Sb2O3 or Sb2O5. Boron compounds are suitable, too.
The above-mentioned additional flame-retardant classes are advantageously contained in the composition of the invention in an amount from about 0.5% to about 45.0% by weight of the organic polymer substrate; for instance about 1.0% to about 40.0%; for example about 5.0% to about 35.0% by weight of the polymer.
As mentioned above, the composition according to the invention may additionally contain one or more conventional additives, for example selected from pigments, dyes, plasticizers, antioxidants, thixotropic agents, levelling assistants, basic co-stabilizers, metal passivators, metal oxides, organophosphorus compounds, further light stabilizers and mixtures thereof, especially pigments, phenolic antioxidants, calcium stearate, zinc stearate, UV absorbers of the 2-hydroxy-benzophenone, 2-(2′-hydroxyphenyl)benzotriazole and/or 2-(2-hydroxyphenyl)-1,3,5-triazine groups. More specific examples are the following components:
Preferred additional additives for the compositions as defined above are processing stabilizers, such as the above-mentioned phosphites and phenolic antioxidants, and light stabilizers, such as benzotriazoles. Preferred specific antioxidants include octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (IRGANOX 1076). Specific processing stabilizers include tris(2,4-di-tert-butylphenyl) phosphite (IRGAFOS 168) and tetrakis(2,4-di-tert-butylphenyl)[1,1-biphenyl]-4,4′-diylbisphosphonite (IRGAFOS P-EPQ). Specific light stabilizers include 2-(2H-benzotriazole-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (TINUVIN 234), 2-(5-chloro(2H)benzotriazole-2-yl)-4-(methyl)-6-(tert-butyl)phenol (TINUVIN 326), 2-(2H-benzotriazole-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol (TINUVIN 329), 2-(2H-benzotriazole-2-yl)-4-(tert-butyl)-6-(sec-butyl)phenol (TINUVIN 350), 2,2′-Methylenebis(6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol) (TINUVIN 360), and 2-(4,6-Diphenyl-1,3,5-triazin-2-yl)-5-[(hexyl)oxy]-phenol (TINUVIN 1577).
The additives mentioned above are preferably contained in an amount of 0.01 to 10.0%, especially 0.05 to 5.0%, relative to the weight of the polymer component b).
The incorporation of the additive component a) and optional further components into the polymer component b) is carried out by known methods such as dry blending in the form of a powder, or wet mixing in the form of solutions, dispersions or suspensions for example in an inert solvent, water or oil. The additive components a) and optional further additives may be incorporated, for example, before or after molding or also by applying the dissolved or dispersed additive or additive mixture to the polymer material, with or without subsequent evaporation of the solvent or the suspension/dispersion agent. They may be added directly into the processing apparatus (e.g. extruders, internal mixers, etc.), e.g. as a dry mixture or powder, or as a solution or dispersion or suspension or melt.
The addition of the additive components to the polymer substrate b) can be carried out in customary mixing machines in which the polymer is melted and mixed with the additives. Suitable machines are known to those skilled in the art. They are predominantly mixers, kneaders and extruders.
The process is preferably carried out in an extruder by introducing the additive during processing.
Particularly preferred processing machines are single-screw extruders, contra rotating and co-rotating twin-screw extruders, planetary-gear extruders, ring extruders or co kneaders. It is also possible to use processing machines provided with at least one gas removal compartment to which a vacuum can be applied.
Suitable extruders and kneaders are described, for example, in Handbuch derKunststoffextrusion, Vol. 1 Grundlagen, Editors F. Hensen, W Knappe, H. Potente, 1989, pp. 3-7, ISBN:3-446-14339-4 (Vol. 2 Extrusionsanlagen 1986, ISBN 3-446-14329-7).
For example, the screw length is 1-60 screw diameters, preferably 35-48 screw diameters. The rotational speed of the screw is preferably 10-600 rotations per minute (rpm), preferably 25-300 rpm.
The maximum throughput is dependent on the screw diameter, the rotational speed and the driving force. The process of the present invention can also be carried out at a level lower than maximum throughput by varying the parameters mentioned or employing weighing machines delivering dosage amounts.
If a plurality of components is added, these can be premixed or added individually.
The additives component a) and optional further additives can also be sprayed onto the polymer substrate b). The additive mixture dilutes other additives, for example the conventional additives indicated above, or their melts so that they can be sprayed also together with these additives onto the polymer substrate. Addition by spraying during the deactivation of the polymerisation catalysts is particularly advantageous; in this case, the steam evolved may be used for deactivation of the catalyst. In the case of spherically polymerised polyolefins it may, for example, be advantageous to apply the additives of the invention, optionally together with other additives, by spraying.
The additive component a) and optional further additives can also be added to the polymer in the form of a master batch (“concentrate”) which contains the components in a concentration of, for example, about 1.0% to about 40.0% and preferably 2.0% to about 20.0% by weight incorporated in a polymer. The polymer is not necessarily of identical structure than the polymer where the additives are added finally. In such operations, the polymer can be used in the form of powder, granules, solutions, and suspensions or in the form of lattices.
Incorporation can take place prior to or during the shaping operation. The materials containing the additives of the invention described herein preferably are used for the production of molded articles, for example roto-molded articles, injection molded articles, profiles and the like, and especially a fiber, spun melt non-woven, film or foam.
Thus, present invention further pertains to a molded or extruded article, a fiber, spun melt non-woven or a foam comprising the composition of the invention.
The following examples illustrate the invention:
PC 145 Resin (GE Plastics) is vacuum-dried for 8 h at 120° C. and stabilized with IRGAFOS® P-EPQ (Ciba Specialty Chemicals). Dyneon PA5931(=PTFE) is used as an anti-dripping agent.
The polycarbonate compositions shown in Tab. 1 are extruded on a Haake TW-100 at 280° C. and pelletized by strand granulation. After drying at 120° C. for 12 h, the granulated compositions are injection molded at 290° C. into plaques of 1.6 mm or 3.2 mm thickness according to Underwriter's Laboratories flame retardancy standard UL-94.
Flame retardancy is tested according to UL-94 in the vertical mode.
Flame Retardant (FR) present in composition:
| Number | Date | Country | Kind |
|---|---|---|---|
| 06110190.3 | Feb 2006 | EP | regional |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP2007/051315 | 2/12/2007 | WO | 00 | 8/7/2008 |
