WO2024159089A1

WO2024159089A1 - Flame retardant and orange colorant combined for use with thermoplastics

Info

Publication number: WO2024159089A1
Application number: PCT/US2024/013095
Authority: WO
Inventors: Qingliang HE; Patrick Jacobs; Christopher Simpson
Original assignee: Lanxess Corporation
Priority date: 2023-01-27
Filing date: 2024-01-26
Publication date: 2024-08-02

Abstract

The present disclosure relates to a novel flame retardant and colorant additive composition for thermoplastic polymers, the additive composition including at least one phosphorus- containing flame retardant and an orange colorant, as described herein. The presently disclosed additive compositions are useful over a wide range of thermoplastic applications, particularly in thermoplastic polymers that are processed and/or used at high temperatures. The resultant thermoplastic compositions have a ΔE of <20, preferably a ΔE<10, more preferably ΔE<5, from a color number beginning with "2" in the RAL color chart. Use of the additive composition improves processing of thermoplastics.

Description

FLAME RETARDANT AND ORANGE COLORANT COMBINED FOR USE WITH THERMOPLASTICS

FIELD OF THE INVENTION

The present disclosure relates to a flame retardant and an orange colorant additive composition for thermoplastic polymers and to compositions combining the flame retardant, colorant, and one or more thermoplastic polymers.

BACKGROUND OF THE INVENTION

During melt processing of thermoplastics, a variety of additives are often added, serving various purposes, e.g., antioxidants, lubricants, stabilizers, flame retardants, etc. While essential for providing flame retardancy to thermoplastics, flame retardant additives can impact the stability of thermoplastics during melt processing, such as by increasing polymer degradation and/or discoloration. For example, these types of effects have been discussed and reported in the literature for certain phosphorus-containing flame retardants, such as described in US Patent Nos. 7,255,814 and 9,534,109 for phosphinate flame retardants.

E-Mobility is increasingly a leading trend in the industry, where high voltage cable and plastic parts used in this segment will typically have a warning color coding, which is often orange. Accordingly, experts in flame retardant industry are looking for a non-halogenated flame retardant system that will not have a negative impact to orange color dyes or pigments. More importantly, the orange color cannot compromise process stability, flame retardancy and other ancillary properties like mechanical and/or electrical properties. Meeting these objectives with commercially available flame retardants has proven difficult.

US 2022/0153962 describes high-voltage components, especially high-voltage components for electromobility, containing thermoplastic polymer compositions based on polyamide and 10,10'-oxybis-12H-phthaloperin-12-one [CAS No. 203576-97-0] for signal color orange. Although not exemplified, flame retardants are an optional component for the thermoplastic components with a preferred flame retardant being aluminum tris(diethylphosphinate) [CAS No. 225789-38-8], such as Exolit® OP1230 or Exolit® OP1240 from Clariant International Ltd. Muttenz, Switzerland. The application does, however, not disclose an additive composition for adding to thermoplastics that contains a flame retardant and a colorant combined prior to being added to polyamide.

When the present inventors added the disclosed colorant of US 2022/0153962 to Exolit OP 1312 (the preferred phosphorous-containing flame retardant taught), in glass filled PA66, it destabilized the injection molding process. Additionally, the orange dye imparted a dark dull reddish color as opposed to a bright orange. Therefore, there is a need for phosphorous- containing flame retardants that are compatible with 10,10'-oxybis-12H-phthaloperin-12-one and other orange colorants in polyamides. There is further a need to combine phosphorous flame retardant and colorant, as well as other thermoplastic additives, in a stable additive composition that may be utilized not just with polyamide, but with a variety of thermoplastic polymers.

The present disclosure utilizes a newer class of phosphorus-containing flame retardant in an additive composition for thermoplastic polymers that stabilizes the injection molding process and will result in bright orange colored thermoplastics. The phosphorus containing flame retardants of the present disclosure, which are also described in the present Applicant’s copending patent application nos. PCT/US2019/067184, PCT/US2019/067221 , and PCT/US2019/067230, provide the additional benefit of being compounded into thermoplastic polymers at high temperatures, such as high temperature polyamides and polyterephthalate esters, without decomposing due to the high thermal stability of these phosphorus-containing flame retardants.

The inventors’ co-pending patent applications PCT/US2021/037706, PCT/US2021/037716 and PCT/US2022/050062 describe such flame retardants with stabilizer and with synergist and stabilizer for use in thermoplastics but do not disclose how thermal stability and/or processability of such systems would be impacted by a colorant. Unexpectedly, the flame retardant additive compositions previously disclosed by Applicant were compatible with orange dye, such as 10,10'-oxybis-12H-phthaloperin-12-one, and are able to provide orange flame retardant thermoplastic compositions with enhanced processability during extrusion and injection molding processes without negative effect to the flame retardant performance. Moreover, the additive compositions produce thermoplastics with a bright orange hue.

The presently disclosed colorant containing additive compositions are therefore useful over a wide range of thermoplastic applications, particularly in thermoplastic polymers used in e- mobility applications that are processed and/or used at high temperatures.

SUMMARY OF THE INVENTION

The present disclosure provides a flame retardant and colorant additive composition, for thermoplastic polymers, comprising

(A) at least one phosphorus-containing flame retardant of empirical formula (I):

wherein R an alkyl or aryl group, M is a metal and y is 2 or 3, such that M^(+)y is a metal cation where (+)y represents the charge formally assigned to the cation, a, b, and c represent the ratio of the components to which they correspond relative to one another in the compound, and satisfy the charge-balance equation 2(a)+c=b(y), and a and c are not zero, and (B) an orange colorant.

In certain preferred embodiments, R is unsubstituted alkyl, y is 3 and a and c are not zero.

More preferably, a is 1 , b is 1 , c is 1 and M is Al or Fe. Most preferably, M is Al and the flame

most preferably where R is methyl or ethyl.

The flame retardant and colorant additive composition may further comprise (C) at least one flame retardant synergist and/or additional flame retardant. The additive composition may additionally comprise (D) one or more stabilizers.

In some embodiments, the (C) at least one flame retardant synergist and/or additional flame retardant comprises a nitrogen-containing flame retardant synergist, such as melam or melamine polyphosphate. In some embodiments, component (C) comprises polydibromostyrene.

In certain embodiments, the (D) stabilizer is chosen from zinc borate or zinc stannate. In some embodiments, the (D) stabilizer comprises a carbodiimide, such as an aromatic polycarbodiimide.

In some embodiments, the flame retardant and colorant additive composition comprises from 20 to 99.95 wt%, such as from 40 to 95 wt% or from 50 to 90 wt%, based on the total weight of the additive composition, of the at least one phosphorus-containing flame retardant (A), from 0.01 to 50 wt%, such as from 0.05 to 25 wt%, from 0.1 to 20 wt% or from 0.5 to 10 wt%, based on the total weight of the additive composition, of the at least one colorant (B), from 0 to 80 wt%, such as from 10 to 60 wt% or from 20 to 50 wt%, based on the total weight of the additive composition, of the at least one flame retardant synergist and/or additional flame retardant (C), and from 0 to 35 wt%, such as from 0 to 10 wt%, based on the total weight of the additive composition, of the one or more stabilizers (D).

The present disclosure additionally provides a method of improving processing of thermoplastics by adding the flame retardant and colorant additive composition comprising or consisting of (A) and (B) to a thermoplastic polymer. The additive composition used in the method may further comprise or consist of any combination of (C) and (D) with (A) and (B).

The present disclosure further provides a flame retardant thermoplastic composition comprising

(i) at least one thermoplastic polymer,

(ii) at least one phosphorus-containing flame retardant of empirical formula (I) above, and

(iii) an orange colorant.

In some embodiments, the at (i) least one thermoplastic polymer is chosen from the group consisting of polyesters and polyamides. In some of those embodiments, the (i) thermoplastic polymer comprises or consists of polyamide 6,6 (PA 66), and/or polyamide-6 (PA 6).

Preferably, the flame retardant (II) is of formula (II), where R is methyl or ethyl, and the orange colorant is a perinone, such as Solvent Orange 11 or Solvent Orange 60.

In some embodiments, the at least one thermoplastic polymer (i) is present in the flame retardant thermoplastic composition in an amount of from 30 to 95 wt%, such as from 40 to 90 wt% or from 50 to 90 wt%, based on the total weight of the flame retardant thermoplastic composition. In certain embodiments, the phosphorus-containing flame retardant (ii) is present in an amount of from 1 to 30 wt%, such as from 3 to 20 wt%, based on the total weight of the flame retardant thermoplastic composition. The at least one orange colorant (iii) is present in the flame retardant thermoplastic composition in an amount of from 0.01 to 5 wt%, such as from 0.05 to 2.5 wt%, from 0.1 to 2.0 wt% or from 0.2 to 1 .0 wt% or 0.2 to 0.5 wt%, based on the total weight of the composition.

The flame retardant thermoplastic composition may further comprise (iv) at least one inorganic filler (e.g., glass fiber), (v) at least one flame retardant synergist and/or additional flame retardant, and/or (vi) at least one stabilizer, and/or (vii) one or more further additives to enhance the properties of the thermoplastic composition. In some embodiments, the (v) at least one flame retardant synergist and/or additional flame retardant comprises a nitrogen-containing flame retardant synergist, such as melam or melamine polyphosphate. In some embodiments, component (v) comprises polydibromostyrene.

In certain embodiments, the (vi) stabilizer is chosen from zinc borate or zinc stannate. In some embodiments, the (vi) stabilizer comprises a carbodiimide, such as an aromatic polycarbodiimide.

The at least one inorganic filler in the flame retardant thermoplastic composition is from 1 to 50 wt%, e.g., from 5 to 50 wt%, from 10 to 40 wt%, or from 15 to 30 wt%, based on the total weight of the flame retardant thermoplastic composition. The (vi) at least one stabilizer is often from 0.01 to 5 wt%, based on the total weight of the flame retardant thermoplastic composition.

In some preferred embodiments, the flame retardant thermoplastic composition comprises the at least one thermoplastic polymer (i) in an amount of from 40 to 90 wt%, the at least one phosphorus-containing flame retardant (ii) in an amount of from 3 to 20 wt%, the orange colorant (iii) in an amount of from 0.01 to 5 wt%, the at least one inorganic filler (iv) in an amount of from 10 to 40 wt%, the at least one flame retardant synergist and/or additional flame retardant (v) in an amount of from 5 to 25 wt%, all based on the total weight of the flame retardant thermoplastic composition. In some embodiments, the composition further comprises at least one stabilizer (vi) in an amount of from 0.01 to 5 wt%, based on the total weight of the flame retardant thermoplastic composition.

The preceding summary is not intended to restrict in any way the scope of the claimed invention. In addition, it is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

DETAILED DESCRIPTION

Unless otherwise specified, the word “a” or “an” in this application means “one or more than one .

The term “alkyl” in this application includes “arylalkyl,” unless the context dictates otherwise.

The term “aryl” in this application includes “alkylaryl,” unless the context dictates otherwise. The term “phosphonic acid” as used herein refers to alkyl or aryl substituted phosphonic acid, unless the context dictates otherwise.

The term “pyrophosphonic acid” as used herein refers to alkyl or aryl substituted pyrophosphonic acid, unless the context dictates otherwise.

represent the ratio of the components to which they correspond relative to one another in the compound, and satisfy the charge-balance equation 2(a)+c=b(y), and a and c are not zero, and

(B) an orange colorant.

The at least one phosphorus-containing flame retardant of the present disclosure (component (A)) has the following empirical formula:

wherein R is an alkyl or aryl group, M is a metal and y is 2 or 3, such that M^(+)y is a metal cation where (+)y represents the charge formally assigned to the cation, a, b, and c represent the ratio of the components to which they correspond relative to one another in the compound, and satisfy the charge-balance equation 2(a)+c=b(y), and a and c are not zero.

Often, a is 1 or 2, b is from 1 to 4, e.g., 1 or 2, and c is 1 or 2, and the product is charged balanced. Examples of suitable metals (M) include, but are not limited to, Al, Ga, Sb, Fe, Co, B, Bi, Mg, Ca, and Zn. As is common with inorganic coordination compounds, formula (I) is empirical or idealized such that the compounds may be coordination polymers, complex salts, salts where certain atomic valences are shared, etc. For example, in many embodiments, empirical formula (I) represents a monomer unit (i.e., coordination entity) of a coordination polymer, the extended coordination polymer structure thereby forming the phosphorus-containing flame retardant of the present disclosure.

In certain embodiments, y in formula (I) is 2 (i.e., M^(+)y is a di-cationic metal). In certain embodiments, the di-cationic metal M is Mg, Ca, or Zn. In other embodiments, y in formula (I) is 3 (i.e., M^(+)y is a tri-cationic metal), a is 1 , b is 1 , and c is 1 . In certain embodiments, the tri-cationic metal M is chosen from Al, Ga, Sb, Fe, Co, B, and Bi. In certain embodiments, the tri-cationic metal M is Al, Fe, Ga, Sb, or B.

In one example, M is Al and y is 3 and the phosphorus-containing flame retardant has the following empirical formula:

As shown herein, the absence of subscripts a, b and c in an empirical formula indicates that the subscripts are each 1 , signifying a 1 : 1 : 1 ratio of the di-anionic pyrophosphonic acid ligand, metal atom, and mono-anionic pyrophosphonic acid ligand. In many embodiments, empirical formula (II) represents a repeating monomer unit (i.e., coordination entity) of a coordination polymer, the extended coordination polymer structure thereby forming the phosphorus-containing flame retardant of the present disclosure.

Often, R is C1-12 alkyl, C₆-io aryl, C7-18 alkylaryl, or C7-18 arylalkyl, wherein said alkyl, aryl, alkylaryl, or arylalkyl are unsubstituted or are substituted by halogen, hydroxyl, amino, C1.4 alkylamino, di-Ci.4 alkylamino, C1-4 alkoxy, carboxy or C2-5 alkoxycarbonyl. In some embodiments, said alkyl, aryl, alkylaryl, or arylalkyl are unsubstituted C1-12 alkyl, C₆ aryl, C7-10 alkylaryl, or C7-10 arylalkyl, for example, Ci_₆ alkyl, phenyl, or C7-9 alkylaryl. In some embodiments, R is substituted or unsubstituted Ci_₆ alkyl, C₆ aryl, C7-10 alkylaryl, or C7-12 arylalkyl, e.g., C1.4 alkyl, C_s aryl, C7-9 alkylaryl, or C7-10 arylalkyl. In many embodiments, R is unsubstituted C1.12 alkyl, e.g., Ci_₆ alkyl. In many embodiments, lower alkyl phosphonic acids are used, e.g., methyl-, ethyl-, propyl-, isopropyl-, butyl-, t-butyl- and the like. R as alkyl may be a straight or branched chain alkyl group having the specified number of carbons and includes e.g., unbranched alkyls such as methyl, ethyl, propyl, butyl, pentyl, hexyl heptyl, octyl, nonyl, decyl, undecyl, dodecyl, and branched alkyl such as isopropyl, isobutyl, sec-butyl, t-butyl, ethyl hexyl, t-octyl and the like. For example, R as alkyl may be chosen from methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-buty, and t-butyl. In many embodiments, R is methyl, ethyl, propyl or isopropyl, for example methyl or ethyl.

Often, when R is aryl it is phenyl. Examples of R as alkylaryl include phenyl substituted by one or more alkyl groups, for example groups selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-buty, t-butyl, and the like. Examples of R as arylalkyl, include for example, benzyl, phenethyl, styryl, cumyl, phenpropyl and the like.

In many embodiments, R is chosen from methyl, ethyl, propyl, isopropyl, butyl, phenyl and benzyl. In certain embodiments, R is methyl, ethyl, propyl, isopropyl or butyl and M is Al, Fe, Zn or Ca.

In certain preferred embodiments, R is unsubstituted alkyl, y is 3 and a and c are not zero. More preferably, a is 1 , b is 1 , and c is 1 and M is Al or Fe. Most preferably, M is Al.

The phosphorus-containing flame retardant of the present disclosure has a high phosphorus content (i.e., a higher ratio of phosphorus atoms to metal atoms (P to M)) as compared to phosphorus-containing flame retardants described in the art. For example, tri-cationic metals (e.g., aluminum) and di-cationic metals (e.g., zinc) are known to form tri-substituted and di-substituted charge balanced compounds, respectively. As seen in the art, tris- phosphonate aluminum salts — having a phosphorus to aluminum ratio of 3:1 — and di- phosphonate zinc salts — having a phosphorus to zinc ratio of 2:1 — are known as flame retardants. However, in accordance with the pyrophosphonic acid ligand formation of the present disclosure, the ratio of phosphorus to metal in the flame retardant product is higher. For example, as demonstrated in the Examples disclosed herein, the ratio of phosphorus to aluminum, or the ratio of phosphorus to iron, in the resulting flame retardant product was 4:1 .

The phosphorus-containing flame retardant of the present disclosure can be a mixture of compounds of empirical formula (I).

The phosphorus-containing flame retardant of empirical formulas (I) and (II) may be prepared by a process as disclosed in WO 2020/132075 or WO 2021/076169. Additionally, the phosphorus-containing flame retardant of empirical formula (I) may be prepared by preparing a metal phosphonic acid solution; and reacting a reaction mixture of alkyl or aryl substituted pyrophosphonic acid with the metal phosphonic acid solution at a reaction temperature from 130 °C to 240 °C, preferably 190 °C to 210 °C, more preferably 195 °C to 205 °C, for an amount of time sufficient to produce the phosphorus-containing flame retardant. The process will typically include preparing the alkyl or aryl substituted pyrophosphonic acid before adding it to the reaction mixture with the metal phosphonic acid solution.

The pyrophosphonic acid prepared and/or used in the process may be represented by the following formula:

wherein R is as described above and preferably is unsubstituted alkyl, such as methyl or ethyl.

The process of preparing the unsubstituted or alkyl or aryl substituted pyrophosphonic acid may comprise adding a catalyst to unsubstituted or substituted phosphonic acid, and heating for an amount of time sufficient to produce the unsubstituted or substituted pyrophosphonic acid. A heating temperature of 105 °C or higher is used. In certain embodiments, where the temperature to heat the unsubstituted or substituted phosphonic acid is about 240°C or higher, and a vacuum or nitrogen purge is utilized, a catalyst may not be necessary to produce pyrophosphonic acid. The nitrogen flow rate is typically about 2L/min to about 6L/min, most preferably about 5L/min. Alternatively, a catalyst may not be necessary where vacuum is pulled below 10 Torr.

The phosphonic acid used to form the pyrophosphonic acid is preferably unsubstituted C-i. 12 alkyl, e.g., C1-6 alkyl, more preferably methyl or ethyl.

The catalyst used to prepare pyrophosphonic acid may be any Lewis Acid that facilitates dehydration. The catalyst can be present in the reaction in an amount ordinarily ranging from about 0.001 to about 0.5 mol % and preferably from about 0.01 to 0.1 mol % based on the weight of the reactants.

In preparation of the metal phosphonic acid solution, the phosphonic acid used is as described above. The metal phosphonic acid solution may be prepared from a mixture comprising (a) the alkyl or aryl substituted phosphonic acid, (b) a solvent for the phosphonic acid, and (c) a metal or suitable metal compound, which are reacted at a temperature above the melting point of the phosphonic acid but below the boiling point of the phosphonic acid to ensure that a solution is maintained and no metal phosphonic acid salt is formed. That is, the metal phosphonic acid should be free of precipitate. Typically, the components (a), (b), and (c) will be mixed at temperature ranging from 100 °C to 280 °C. Often, the ratio by weight of the phosphonic acid (a) to the solvent (b) ranges from about 1 :3 to 1 :50, more preferably about 1 .2.5 to 1 :25, most preferably about 1 .2.75.

The metal of the metal phosphonic acid solution should be capable of being oxidized and may be represented in its corresponding cationic form by the formula M^(+)y where M is a metal, (+)y represents the charge of the metal cation, and y is 3. A suitable metal compound may be represented by the formula M^^+)yXq, where M is a metal, (+)y represents the charge of the metal cation, y is 3, X is an anion, and the values for p and q provide a charge balanced metal compound.

Suitable solvents may be organic or inorganic. Examples of suitable solvents for the phosphonic acid include, but are not limited to, water, sulfones, sulfoxides, halogenated (e.g., chlorinated) hydrocarbons, aromatic hydrocarbons, and ethers.

The reaction mixture is heated or reacted at the reaction temperature for an amount of time sufficient to produce the phosphorus-containing flame retardant. Often, the flame retardant product will precipitate from the reaction mixture such that the reaction is run for a time sufficient to achieve such precipitation. After reacting, the product reaction mixture is cooled ensuring that the pyrophosphonic acid remains in liquid form. The excess pyrophosphonic acid and the solvent if present in the product reaction mixture can be removed by filtration/washing and optionally recovered. The recovered excess pyrophosphonic acid and/or solvent may be recycled, e.g., back into the reactor in which a metal phosphonic acid solution reacts with the pyrophosphonic acid. The flame retardant product is often isolated by filtration, optionally followed by additional work up (e.g., washing, drying, sieving, etc.). The resulting crystalline flame retardant product, which is generally in the form of a powder or small particles, is readily processable, i.e., without requiring or necessitating grinding, milling, or other such physical processing before use.

The phosphorus-containing flame retardant of the present disclosure may further contain a compound or mixture of different compounds of empirical formula (IX)

wherein R is H, an alkyl, aryl, alkylaryl or arylalkyl group, a, b, c and d represent the ratio of the components to which they correspond relative to one another in the compound, and a is generally a number of from 0 to 8, e.g., from 0 to 6, from 0 to 4, or from 0 to 2, c is generally a number of from 0 to 10, e.g., from 0 to 8, from 0 to 6, from 0 to 4 or from 0 to 2, d is generally a number of from 1 to 6, e.g., 1 to 4 or 1 to 2, M is a metal, y is a number of from 2 to 5, such as 2, 3 or 4, often 2 or 3, and M<⁺>y is a metal cation where (+)y represents the charge formally assigned to the cation. The values of a, b, c, d and y may vary, but will satisfy the charge-balance equation 2(a)+c+d=b(y), and only one of a or c can be 0. In many embodiments, c is not zero. In instances where a di-anionic phosphonic acid ligand is present in the compound, the charge balance equation becomes 2(a)+c+d+2(d)=b(y). The value for b is limited only in that it must satisfy the preceding equations, but in many embodiments b is a number of from 1 to 4, e.g., 1 or 2. In some embodiments, a is 0, 1 , or 2 (e.g., 0 or 1), c is 1 or 2, and d is 0, 1 , or 2 (e.g., 0 or 1), and the product is charged balanced. Often, c in the formula (IX) above is not zero (e.g., c is from 1 to 10, from 1 to 8, from 1 to 6, from 1 to 4, or 1 or 2).

When a compound or mixture of different compounds of empirical formula (IX) is present, the compound or mixture of compounds of formulas (I) and/or (II) typically makes up all, substantially all, or at least a majority of the flame retardant product, such as at least 75%, 85%, 90%, 95%, 98%, or higher, or any range therebetween, by weight of the flame retardant product. In certain embodiments, the at least one phosphorus-containing flame retardant of the present disclosure (component (A) consists of a compound or mixture of compounds of formulas (I) and/or (II).

Compounds of formula (IX) can be prepared according to various methods, such as those disclosed in U.S. Pat. Nos. 9,534,108; 9,745,449; 9,752,011 ; 9,758,640; and 9,765,204; and WO 2021/132095.

The compositions will further comprise (B) an orange colorant, preferably a solvent dye.

In the context of the present invention, orange is considered to mean a color which, in the RAL color system according to https://de.wikipedia.Org/wiki/RAL-Farbe#Orange, has a color number beginning with a “2” in the RAL color chart. In particular, a distinction is made between orange shades according to Table 1 :

TABLE 1

L* _a* _b*

RAL 2000 Yellow orange 58.20 37.30 68.68

RAL 2001 Red orange 49.41 39.79 35.29

RAL 2002 Blood orange 47.74 47.87 33.73

RAL 2003 Pastel orange 66.02 41.22 52.36

RAL 2004 Pure orange 56.89 50.34 49.81

RAL 2005 Luminous orange 72.27 87.78 82.31

RAL 2007 Luminous bright orange 76.86 47.87 97.63

RAL 2008 Bright red orange 60.33 46.91 60.52

RAL 2009 T raffic orange 55.83 47.79 48.83

RAL 2010 Signal orange 55.39 40.10 42.42

RAL 2011 Deep orange 59.24 40.86 64.50

RAL 2012 Salmon orange 57.75 40.28 30.66

RAL 2013 Pearl orange 40.73 32.14 34.92

RAL 2017 RAL orange

Tab. 1 shows the apparatus-independent CIE L*a*b* color values for the respective RAL value: L* stands for luminance, a*=D65 and b*=10°. The color model is standardized in EN

ISO/CIE 11664-4 “Colorimetry — Part 4: CIE 1976 L*a*b* colour space”. For L*a*b* color space (also: CIELAB) see: https://de.wikipedia.org/wiki/Lab-Farbraum. Each color in the color space is defined by a color locus having the Cartesian coordinates {L*, a*, b*}. The a*b* coordinate plane was constructed using opponent color theory. Green and red are at opposite ends of the a* axis from one another and the b* axis runs from blue to yellow. Complementary shades are respectively opposite one another at a 180° angle; the midpoint between them (the coordinate origin a*=0, b*=0) is gray.

The L* axis describes the brightness (luminance) of the color with values of 0 to 100. In the diagram it stands perpendicular to the a*b* plane at the origin. It may also be referred to as the neutral gray axis since all achromatic colors (gray shades) are contained between the endpoints of black (L*=0) and white (L*=100). The a* axis describes the green or red fraction of a color, with negative values representing green and positive values representing red. The b* axis describes the blue or yellow fraction of a color, with negative values representing blue and positive values representing yellow.

The a* values range from approximately -170 to +100 and the b* values from -100 to +150, with the maximum values being achieved only at moderate brightness of certain shades. The CIELAB color solid has its greatest extent in the region of moderate brightness, although this differs in height and size depending on the color range.

The invention encompasses orange-like shades that have a color distance AE<20 between the L*a*b* coordinates of the polymer composition and the L*a*b* coordinates of a color number beginning with “2” in the RAL color chart, preferably a AE<10, more preferably AE<5.

Suitable orange colorants are dyes of the perinone type. Examples of perinone dyes suitable for dyeing of plastics are described in U.S. Patent Nos. 5,466,805; 5,530,130; and 5,955,614, the contents of which is incorporated herein.

In certain embodiments, 10,10'-oxybis-12H-phthaloperin-12-one [CAS No. 203576-97-0], also known as Solvent Orange 11 , of the formula (X) meets the required requirements.

10,10'-Oxybis-12H-phthaloperin-12-one may either be prepared by the synthesis route specified in EP 1 118 640 A1 under example 3) or is obtainable from Angene International Limited, UK Office, Churchill House, London or Lanxess Deutschland GmbH, Cologne.

10,10'-Oxybis-12H-phthaloperin-12-one may be used directly in powder form or else in the form of a masterbatch, compact or concentrate, preference being given to masterbatches and particular preference to with the flame retardants and other components described herein.

In one particularly preferred embodiment, the orange colorant is Macrolex® Orange HT from Lanxess Deutschland GmbH, Cologne.

In other embodiments, the orange colorant may be 12H-Phthaloperin-12-one [CAS No. 6925-69-5], known as Solvent Orange 60, obtainable for example as Macrolex® Orange 3G from Lanxess Deutschland GmbH, Cologne.

Most preferably, the orange colorant is Macrolex® Orange HT from Lanxess Deutschland GmbH, Cologne. Thermoplastics containing the additive compositions for electromobility are preferably colored orange, with particular preference for shades corresponding in the RAL color system to the color numbers RAL2001 , RAL2003, RAL2004, RAL2007, RAL2008, RAL2009, RAL2010 and RAL2011 , and very particular preference for the shades corresponding in the RAL color system to the color numbers RAL2003, RAL2008 and RAL2011.

“Similar shades” permissible in accordance with the invention are shades whose color distance in the L*a*b* system has a AE of <20, preferably a AE<10, more preferably AE<5, from a color number beginning with “2” in the RAL color chart. For elucidation of AE defined in EN ISO 11664-4 see, for example: https://de.wikipedia.org/wiki/Delta_E.

The flame retardant and colorant additive composition may further comprise at least one flame retardant synergist and/or additional flame retardant (component (C)).

Examples of suitable flame retardant synergists include condensation products of melamine (e.g., melam, melem, melon), melamine cyanurate, reaction products of melamine with polyphosphoric acid (e.g., dimelamine pyrophosphate, melamine polyphosphate), reaction products of condensation products of melamine with polyphosphoric acid (e.g., melem polyphosphate, melam polyphosphate, melon polyphosphate), melamine-poly(metal phosphate) (e.g., melamine-poly(zinc phosphate), a triazine-based compound, such as a reaction product of trichlorotriazine, piperazine and morpholine, e.g., poly-[2,4-(piperazine- 1 ,4-yl)-6-(morpholine-4-yl)-1 ,3,5-triazine]/piperazin (e.g., MCA® PPM Triazine HF), a metal hypophosphite, such as aluminum hypophosphite (e.g., Italmatch Phoslite® IP-A), calcium hypophosphite (e.g., Italmatch Phoslite® IP-C); an organic phosphinate, such as aluminum dialkylphosphinate, e.g., aluminum diethylphosphinate (Exolit OP); and aluminum dihydrogen phosphite, other flame retardants like 9,10-dihydro-9-oxa-10- phosphaphenanthrene-10- oxide (DOPO), di-DOPO, or DOPO derivatives and the like . In many embodiments, a nitrogen-containing synergist is used. Suitable nitrogen-containing synergists may be chosen from, e.g., melamine derivatives such as melamine and its condensation products (melam, melem, melon or similar compounds with higher condensation levels), melamine cyanurate, and phosphorus/nitrogen compounds such as dimelamine phosphate, dimelamine pyrophosphate, melamine phosphate, melamine pyrophosphate, melamine polyphosphate, melam polyphosphate, melon polyphosphate, and melem polyphosphate, and mixed polysalts thereof. Examples of additional flame retardants suitable for the present flame retardant and stabilizer additive composition include halogenated flame retardants, alkyl or aryl phosphine oxide flame retardants, alkyl or aryl phosphate flame retardants, alkyl or aryl phosphonates, alkyl or aryl phosphinates, and salts of alkyl or aryl phosphinic acid. The additive composition may additionally comprise one or more stabilizers (component

(D)).

Examples of suitable stabilizers include carbodiimides, metal hydroxides, oxides, oxide hydrates, borates, molybdates, carbonates, sulfates, phosphates, silicates, siloxanes, stannates, mixed oxide-hydroxides, oxide-hydroxide-carbonates, hydroxide-silicates, hydroxide-borates, preferably where the metal is zinc, magnesium, calcium or manganese, often zinc. In many embodiments, a stabilizer is chosen from zinc borate, zinc stannate, zinc molybdate complex (e.g., Kemgard 911 B), zinc molybdate/magnesium hydroxide complex (e.g., Kemgard MZM), zinc molybdate/magnesium silicate complex (Kemgard 91 1C), calcium molybdate/zinc complex (e.g., Kemgard 911 A), and zinc phosphate complex (e.g, Kemgard 981), polysiloxane, montmorillonite, kaolinite, halloysite, and hydrotalcite.

In certain embodiments, the stabilizer (D) includes at least one carbodiimide (i.e., a compound comprising the functionality -N=C=N-). In certain of those embodiments, the at least one carbodiimide is an aromatic carbodiimide. Preferably, the carbodiimide is polymeric, meaning the compound contains repeating -N=C=N- groups in its chemical structure. Often, the polymeric carbodiimide contains from 2 to 500 groups -N=C=N- per mole, such as from 2 to 100 groups -N=C=N- per mole, e.g., up to 20 such groups or up to 10 groups per mole. In many embodiments, the carbodiimide is a polymeric aromatic carbodiimide. Carbodiimide compounds, including polymeric carbodiimides, are known and can be produced according to known processes.

Preferably, the carbodiimide is of the general formula (III), (IV) or (V) as follows:

where R¹ and R² are independently hydrogen or Ci-C ₀-alkyl , C₆-Ci₂-aryl, C₇-Ci₃-aralkyl, or C₇-Ci3-alkylaryl, a and b are mutually independently a whole number from 1 to 5 and c and d are mutually independently a whole number from 0 to 10;

where R⁴ is NCO,

R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, R¹¹, R¹² are independently hydrogen or Ci-C-io-alkyl, C6-Ci2-aryl, C₇- Ci3-aralkyl, or C₇-Ci3-alkylaryl, g is a whole number from 0 to 5, h is a whole number from 1 to 100; or

where m is a whole number from 1 to 5000, preferably a whole number from 2 to 500, such as 3 to 20 or 4 to 10,

R³ is arylene, alkyl-substituted arylene, alkylaryl-substituted arylene, or aralkyl-substituted arylene, e.g., R³ is chosen from arylene, Ci-Ci₂-alkyl-substituted arylene, C₇-Ci₈- alkylaryl-substituted arylene, C₇-Ci₈-aralkyl-substituted arylene, and Ci-Ci₂-alkyl- substituted Ci-C₈-alkylene-bridged arylene comprising a total of 7 to 30 carbon atoms,

R' is aryl, alkylaryl, aralkyl or R³-NCO,

R" is -N=C=N-aryl, -N=C=N-alkylaryl, -N=C=N-aralkyl or -NCO.

In certain embodiments, R³ is an arylene having one or more aliphatic and/or cycloaliphatic substituents having at least 2 carbon atoms, preferably branched or cyclic aliphatic moieties having at least 3 carbon atoms, at one ortho position, preferably both ortho positions, with respect to the aromatic carbon atom(s) that bears the -N=C=N- group(s). For example, in some embodiments, R³ is

are independently C1-C3 alkyl, e.g., independently methyl, ethyl or isopropyl. In many embodiments, the polymeric aromatic carbodiimide is of the formula (VI):

where R¹³, R¹⁴ and R¹⁵ are independently C1-C3 alkyl, R¹⁶ is -NCO, and n is from 0 to 200, such as from 1 to 100, from 1 to 20 or from 1 to 10. Often, R¹³, R¹⁴ and

R¹⁵ are independently methyl, ethyl or isopropyl. In many embodiments, R¹³, R¹⁴ and R¹⁵ are each isopropyl. In other embodiments, each benzene ring bears only one methyl group.

Other suitable examples of particular carbodiimides are of the formulas (VI I) and (VIII):

where R = NCO, and n is a whole number from 1 to 200, often from 1 to 20.

The quantitative proportions of the components (A), (B), (C) and (D) in the flame retardant and colorant additive composition may vary and may generally depend on, e.g., the intended application, processing conditions, etc. In many embodiments, the flame retardant and colorant additive composition comprises from 20 to 99.95 wt%, such as from 40 to 95 wt% or from 50 to 90 wt%, based on the total weight of the additive composition, of the at least one phosphorus-containing flame retardant (A), from 0.01 to 50 wt%, such as from 0.05 to 25 wt%, from 0.1 to 20 wt% or from 0.5 to 10 wt%, based on the total weight of the additive composition, of the at least one colorant (B), from 0 to 80 wt%, such as from 10 to 60 wt% or from 20 to 50 wt%, based on the total weight of the additive composition, of the at least one flame retardant synergist and/or additional flame retardant (C), and from 0 to 35 wt%, such as from 0 to 10 wt%, based on the total weight of the additive composition, of the one or more stabilizers (D). The present disclosure further provides a flame retardant thermoplastic composition comprising

(i) at least one thermoplastic polymer,

(iii) an orange colorant as described above. The flame retardant thermoplastic composition may further comprise (iv) at least one inorganic filler (e.g., glass fiber), (v) at least one flame retardant synergist and/or additional flame retardant, (vi) one or more stabilizers, and/or (vii) further additives to enhance the properties of the thermoplastic composition.

The at least one thermoplastic polymer (i) is often present in the flame retardant thermoplastic composition in an amount of from 30 to 95 wt%, such as from 40 to 90 wt% or from 50 to 90 wt%, based on the total weight of the flame retardant thermoplastic composition. The at least one thermoplastic polymer may be a thermoplastic polyester, polyamide, polystyrene, including high impact polystyrene (HIPS), polyolefin, polycarbonate, polyurethane, polyphenylene ether, or other thermoplastic polymer. In many embodiments, the thermoplastic polymer comprises a polyester (e.g., a polyalkylene terephthalate) or polyamide. In many embodiments, the thermoplastic polymer comprises a polyamide. More than one thermoplastic polymer (thermoplastic polymer blends) can be used, such as polyphenylene ether/styrenic resin blends, polyvinyl chloride/acrylonitrile butadiene styrene (ABS) or other impact modified polymers, such as methacrylonitrile and a-methylstyrene containing ABS, and polyester/ABS or polycarbonate/ABS. The thermoplastic polymer may be unreinforced or reinforced, for example, glass reinforced, such as a glass-filled polyester (e.g., glass-filled polyalkylene terephthalate) or a glass-filled polyamide.

Examples of thermoplastic polyesters include homopolyesters and copolyesters obtained by polycondensation of an acid component and a diol component. For example, suitable polyesters may be chosen from polybutylene terephthalate and polyethylene terephthalate.

The diol component may contain one or more of the following glycols: ethylene glycol, trimethylene glycol, 2-methyl-1 ,3-propane glycol, 1 ,4-butylene glycol, hexamethylene glycol, decamethylene glycol, cyclohexane dimethanol, or neopentylene glycol. The acid component may contain one or more of the following acids: terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1 ,5- naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4'- diphenoxyethandicarboxylic acid, p-hydroxybenzoic acid, sebacic acid, adipic acid and polyester-forming derivatives thereof. In many embodiments, the thermoplastic polyester is chosen from polyethylene terephthalate), poly(1 ,3-trimethylene terephthalate), poly(1 ,4-butyleneterephthalate), and blends thereof. For example, thermoplastic polyester blends can comprise from about 1 to about 99 parts by weight of one polyester and from about 99 to about 1 part by weight of a different polyester based on 100 parts by weight of both components combined. The poly(1 ,4-butylene terephthalate) may be one obtained by polymerizing a diol component which is comprised of at least 70 mol %, e.g., at least 80 mol %, of 1 ,4-butylene glycol, with an acid component which is comprised of at least 70 mol %, e.g., at least 80 mol %, of terephthalic acid and/or polyester-forming derivatives thereof.

Thermoplastic polyamides include polyamides derived from a diamine and a dicarboxylic acid, polyamides obtained from an aminocarboxylic acid, including in combination with a diamine and/or a dicarboxylic acid, and polyamides derived from a lactam, including in combination with a diamine and/or a dicarboxylic acid. Examples of suitable polyamides include aliphatic polyamides such as polyamide-4,6, polyamide-6, polyamide-6,6, polyamide- 6,10, polyamide-6, 12, polyamide-11 and polyamide-12; polyamides obtained from an aromatic dicarboxylic acid, such as terephthalic acid and/or isophthalic acid, and an aliphatic diamine, such as a hexamethylenediamine or nonamethylenediamine; polyamides obtained from aliphatic dicarboxylic acids, such as adipic acid and/or azelaic acid, and aromatic diamines, such as meta-xylylenediamine; polyamides obtained from both aromatic and aliphatic dicarboxylic acids, such as both terephthalic acid and adipic acid, and an aliphatic diamine, such as hexamethylenediamine; polyamides obtained from adipic acid, azelaic acid, and 2,2-bis-(p-aminocyclohexyl)propane; and polyamides obtained from terephthalic acid and 4,4’-diaminodicyclohexylmethane. Mixtures and/or copolymers of two or more of the foregoing polyamides or prepolymers thereof, respectively, may also be used.

The polyamides may be made by any known method, such as via polymerization of a monoaminomonocarboxylic acid or a lactam thereof having at least two carbon atoms between the amino and carboxylic acid group, of substantially equimolar proportions of a diamine which contains at least two carbon atoms between the amino groups and a dicarboxylic acid, or of a monoaminocarboxylic acid or a lactam thereof as defined above, together with substantially equimolar proportions of a diamine and a dicarboxylic acid. The dicarboxylic acid may be used in the form of a functional derivative thereof, for example, a salt, an ester or acid chloride.

Polyamides with melting points of at least 280 C are used extensively for producing molding compositions which make possible the production of molded articles, e.g. for the electrical and electronics industry, with excellent dimensional stability at high temperatures and with very good flame-retardant properties. Molding compositions of this type are demanded for example in the electronics industry for producing components which are mounted on printed circuit boards according to the so-called surface mounting technology, SMT. In this application, these components must withstand temperatures of up to 270°C for short periods of time without dimensional change.

Such high temperature polyamides include certain polyamides produced from alkyl diamines and diacids, such as polyamide 4,6. Further, many high temperature polyamides are aromatic and semi-aromatic polyamides, i.e., homopolymers, copolymers, terpolymers, or higher polymers that are derived from monomers containing aromatic groups. An aromatic or semi-aromatic polyamide may be employed or blends of aromatic and/or semi-aromatic polyamides may be used. Blends with aliphatic polyamides may also be used.

Examples of suitable high temperature aromatic or semi-aromatic polyamides include polyamide-4,T, poly(m-xylylene adipamide) (polyamide-MXD,6), poly(dodecamethylene terephthalamide) (polyamide- 12, T), poly(decamethylene terephthalamide) (polyamide-10,T), poly(nonamethylene terephthalamide) (polyamide-9,T), hexamethylene adipamide/hexamethylene terephthalamide copolyamide (polyamide-6,T/6,6), hexamethylene terephthalamide/2-methylpentamethylene terephthalamide copolyamide (polyamide-6,T/D,T); hexamethylene adipamide/hexamethylene terephthalamide/hexamethylene isophthalamide copolyamide (polyamide-6,6/6,T/6,l); poly(caprolactam-hexamethylene terephthalamide) (polyamide-6/6,T); hexamethylene terephthalamide/hexamethylene isophthalamide (polyamide-6,T/6,l) copolymer; and the like.

Certain embodiments of the invention are thus to compositions comprising a polyamide that melts at high temperatures, e.g., 280° C or higher, 300°C, or higher, or 320°C or higher. In some embodiments, the polyamide has a melting temperature from 280 to 340°C, such as polyamide 4,6 or the aromatic and semi-aromatic polyamides described above.

Preferred polyamides are polyamide-6, polyamide-6,6, polyamide-11 , polyamide-12, polyphthalamides, such as polyamide-4,T, polyamide-6, T/6, 6, and polyamide-6, 6/6, T/6, 1 copolymers, glass-filled polyamides thereof, and blends thereof. For example, thermoplastic polyamide blends can comprise from about 1 to 99 parts by weight of one polyamide and from about 99 to about 1 part by weight of a different polyamide based on 100 parts by weight of both components combined. In some embodiments, the polymer is a thermoplastic elastomer (e.g., thermoplastic polyolefins or thermoplastic polyurethanes). In some embodiments, the thermoplastic elastomer is a thermoplastic polyurethane.

The at least one phosphorus-containing flame retardant (ii) is as described above and is present in the flame retardant thermoplastic composition in a flame retardant effective amount. Often, the presently disclosed phosphorus-containing flame retardant is present in an amount of from 1 to 30 wt%, such as from 3 to 20 wt%, based on the total weight of the flame retardant thermoplastic composition.

The at least one orange colorant (iii) in the flame retardant thermoplastic composition is as described above and is often present in the flame retardant thermoplastic composition in an amount of from 0.01 to 5 wt%, such as from 0.05 to 2.5 wt%, from 0.1 to 2.0 wt% or from 0.2 to 1.0 wt% or 0.2 to 0.5 wt%, based on the total weight of the composition.

At least one inorganic filler (iv) may be present in the flame retardant thermoplastic composition. As known in the art, an inorganic filler can reduce the molding shrinkage coefficient and linear expansion coefficient of a resultant molded article and improve high and low heat shock property. Various fillers in the form of fiber or non-fiber (e.g., powder, plate) may be used depending on the desired article. Some examples of fibrous filler, which are types of inorganic filler, may be those such as, glass fiber, glass fiber having a noncircular cross section, such as flat fiber, carbon fiber, silica fiber, silica alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, boron fiber, potassium titanate fiber, and further, metal fibrous substances such as stainless, aluminum, titanium, copper and brass. Typical fibrous filler is glass fiber or carbon fiber. Alternatively, the inorganic filler may be a powdery filler, such as carbon black, graphite, silica, quartz powder, glass bead, glass powder, calcium silicate, kaolin, talc, clay, diatomaceous earth, silicates, such as wollastonite, metal oxides, such as iron oxide, titanium oxide, zinc oxide and alumina, metal hydroxides, metal carbonates, such as calcium carbonate and magnesium carbonate, metal sulfates, such as calcium sulfate and barium sulfate, silicon carbide, silicon nitride, boron nitride and various metal powders. Another example of inorganic filler is plate-like filler such as mica, glass flake and various metal foils. These inorganic fillers can be used alone or in combination of two or more. In use, the inorganic fillers are desirably treated previously with a sizing agent or surface treatment agent, if necessary.

When present, the amount of the at least one inorganic filler in the flame retardant thermoplastic composition is often from 1 to 50 wt%, e.g., from 5 to 50 wt%, from 10 to 40 wt%, or from 15 to 30 wt%, based on the total weight of the flame retardant thermoplastic composition.

The flame retardant thermoplastic composition may further comprise at least one flame retardant synergist and/or additional flame retardant (v). Exemplary flame retardant synergists and additional flame retardants are described above. When present, the amount of the at least one flame retardant synergist and/or additional flame retardant (v) is often from 1 to 25 wt%, such as from 5 to 25 wt%, based on the total weight of the flame retardant thermoplastic composition.

The flame retardant thermoplastic composition may further comprise at least one stabilizer (vi). Exemplary additional stabilizers are as described above. When present, the amount of the at least one stabilizer is often from 0.01 to 5 wt%, based on the total weight of the flame retardant thermoplastic composition.

Other ingredients or additives (vii) may be present in the flame retardant thermoplastic composition and are typically employed in amounts less than 10 percent by weight of the flame retardant thermoplastic composition, e.g., less than 5 percent by weight, and include non-limiting examples such as antioxidants, UV stabilizers, lubricants, impact modifiers, plasticizers, other stabilizers or acid scavengers, heat stabilizers, pigments, dyes, optical brighteners, anti-static agents, anti-dripping agents, e.g. PTFE, and other additives used to enhance the properties of the resin.

In many embodiments, the flame retardant thermoplastic composition comprises the at least one thermoplastic polymer (i) in an amount of from 30 to 95 wt%, the at least one phosphorus-containing flame retardant (ii) in an amount of from 1 to 30 wt%, the orange colorant (Hi) in an amount of from 0.001 to 5 wt%, the at least one inorganic filler (iv) in an amount of from 0 to 50 wt%, the at least one flame retardant synergist and/or additional flame retardant (v) in an amount of from 0 to 25 wt%, all based on the total weight of the flame retardant thermoplastic composition. In many embodiments, the flame retardant thermoplastic composition comprises the at least one thermoplastic polymer (i) in an amount of from 40 to 90 wt%, the at least one phosphorus-containing flame retardant (ii) in an amount of from 3 to 20 wt%, the orange colorant (Hi) in an amount of from 0.01 to 5 wt%, such as from 0.05 to 2.5 wt%, from 0.1 to 2.0 wt% or from 0.2 to 1 .0 wt%, or 0.2 to 0.5 wt%, the at least one inorganic filler (iv) in an amount of from 0 to 50 wt%, such as from 10 to 40 wt%, the at least one flame retardant synergist and/or additional flame retardant (v) in an amount of from 0 to 25 wt%, such as from 5 to 25 wt%, all based on the total weight of the flame retardant thermoplastic composition. In some embodiments, the composition further comprises at least one stabilizer (vi) in an amount of from 0 to 5 wt%, such as from 0.01 to 5 wt%, based on the total weight of the flame retardant thermoplastic composition.

Preparing the flame retardant and colorant additive composition

The present invention is not limited by any particular method of mixing the components (A), (B), (C) and (D) of the presently disclosed flame retardant and colorant additive composition. For example, the at least one phosphorus-containing flame retardant (A) and the orange colorant (B), optionally with at least one flame retardant synergist and/or additional flame retardant (C) and/or one or more stabilizers (D) may be mixed/blended by conventional mixing techniques, such as tumble mixing, convective mixing, fluidized bed mixing, high- shear mixing, etc. Conventional processing agents may also be used, e.g., dispersing agents, anti-static agents, binders, coupling agents, etc.

Preparing the flame retardant thermoplastic composition

The present invention is not limited by any particular method of blending the components of the presently disclosed flame retardant thermoplastic composition. Suitable compounding and blending techniques known in the art may be used. For example, one method comprises blending the thermoplastic polymer and additives in powder or granular form and melt-mixing the blend (e.g., using a twin-screw extruder). The thermoplastic polymer, flame retardant, colorant, synergist and other additives are typically pre-dried before melt-mixing. The extruded blend may be comminuted into granular pellets or other suitable shapes by standard techniques. Other melt-mixing process equipment such as a kneader mixer or bowl mixer can be used to compound the flame retardant additives and any additional ingredients with the thermoplastic polymer. In either case, a generally suitable machine temperature may range from about 200° to 330° C, depending on the specific type of thermoplastic selected.

The flame retardant thermoplastic compositions can be molded in any equipment suitable for such purpose, e.g., in an injection molding machine. After pelletizing, the granular pellets are typically re-dried before being molded in an injection molding machine suitable for such purpose. Often, the process temperature ranges from about 200° to 330°C, depending on the molding properties of the specific thermoplastic polymer, loading levels of the additives and/or reinforcement filler, and other factors like thickness and gate size of the mold cavity. Those skilled in the art will be able to make suitable adjustments in the molding process to accommodate the composition or tooling differences.

Further non-limiting disclosure is provided in the Examples that follow. EXAMPLES

Example 1 - Flame Retardant

Methylphosphonic acid (MPA) (3678.8 g, 38.3 mol, 30 eq, 75% aqueous solution) and alumina (130.2 g, 1.28 mol, 1 eq) were mixed at room temperature with limited exotherm observed (about 2 °C increase). The pot temperature was set to 165 °C, with stirrer at 200 RPM under atmospheric pressure, nitrogen purge (4 L/min). When no distillate water was observed at the condenser, 1 .0 g of seeding material, which was the flame retardant product produced from MPA and alumina as described herein, was optionally added. The reaction mixture was heated at 165 °C for 3 hours. The product reaction mixture containing a white slurry product was then cooled to about 130 °C and poured into 1 .5 L of water in a beaker cooled in an ice water bath. The white slurry was then filtered off, washed by water (500 mL x 3), and dried to yield fine crystals at 92% yield. The product had a 4:1 phosphorus to aluminum ratio (ICP Elemental Analysis) according to the following empirical formula:

The product empirical formula above represents repeating monomer units (i.e., coordination entities) of a coordination polymer forming the pure crystalline product.

Example 2 - Flame Retardant

A 1 L flask was charged with 800 mL xylenes and set up with a Dean-Stark trap. The solution was heated to 115 °C and methylphosphonic acid (MPA) (33.89 g, 0.35 mol) was added. The acid was allowed to dissolve and the temperature was increased such that the solution began to reflux. Alumina (4.01 g, 0.039 mol) was added in portions over 3 hours. The reflux was maintained at 142 °C overnight. The resulting solid product was isolated by filtration, washed with DMF (100 mL) and Et20 (2 x 50 mL), and dried to yield a fine powder (18.86 g, 71% yield). The product had a 4:1 phosphorus to aluminum ratio according to the following empirical formula:

Example 3 - Flame Retardant

Methylphosphonic acid (MPA) (2216 g, 23.1 mol, 15 eq, aqueous solution) and aluminum trihydroxide (120 g, 1 .5 mol, 1 eq) were mixed at room temperature. The pot temperature was set to 165 °C, with stirrer at 200 RPM under atmospheric pressure, nitrogen purge (4 L/min). When no distillate water was observed at the condenser, 1.0 g of seeding material, which was the flame retardant product produced from MPA and aluminum trihydroxide as described herein, was optionally added. The reaction mixture was heated at 165 °C for 3 hours. The product reaction mixture containing a white slurry product was then cooled to about 130 °C and poured into 1 .5 L of water in a beaker cooled in an ice water bath. The white slurry was filtered off, washed by water (500 mL x 3), and dried to yield fine crystals at approximately 100% yield. The product had a 4:1 phosphorus to aluminum ratio (ICP Elemental Analysis) according to the following empirical formula:

Example 4 - Flame Retardant

Methylphosphonic acid (MPA) (1412.6 g, 14.7 mol, 30 eq, 75% aqueous solution) and iron oxide (78.2 g, 0.49 mol, 1 eq) were mixed at room temperature. The pot temperature was set to 130 °C for about 12 hours, with stirrer at 250 RPM under atmospheric pressure, nitrogen purge (4 L/min). The reaction mixture was subsequently heated to 165 °C for 12 hours. The product reaction mixture containing an off-white slurry product was then cooled to about 130 °C and poured into 1.5 L of water in a beaker cooled in an ice water bath. The off-white slurry was filtered off, washed by water (500 mL x 3), and dried to yield fine off- white color crystals at 92% yield. The product had a 4:1 phosphorus to iron ratio (ICP Elemental Analysis) according to the following empirical formula:

Example 5 - Flame Retardant

Methylphosphonic acid (MPA) (1727 g, 18.4 mol, 15 eq, 75% aqueous solution) was cooled to 5 °C in an ice water bath under nitrogen flow (1 L/min). Aluminum isopropoxide (250 g, 1 .2 mol, 1 eq) was added in portions as the pot temperature was maintained below 10 degree C. The pot temperature was then set to 165 °C, with stirrer at 250 RPM. At 165 °C, 4.5 g of seeding material, which was the flame retardant product produced from MPA and aluminum isopropoxide as described herein, was optionally added, and the reaction mixture was kept at 165 °C for 3 hours. The product reaction mixture containing a white slurry product was then cooled to about 130 °C and poured into 1 .5 L of water in a beaker cooled in an ice water bath. The white slurry was filtered off, washed by water (500 mL x 3), and dried to yield fine crystals at 44% yield. The product had a 4:1 phosphorus to aluminum ratio (ICP Elemental Analysis) according to the following empirical formula:

The product empirical formula above represents repeating monomer units (i.e., coordination entities) of a coordination polymer forming the pure crystalline product. Example 6 - Flame Retardant

Ethylphosphonic acid (EPA) (55.0 g, 0.50 mol, 30 eq) and alumina (1.70 g, 17 mmol, 1 eq) were mixed at room temperature with 50 mL of water. The pot temperature was set to 165 °C, with stirrer at 250 RPM under atmospheric pressure, nitrogen purge (4 L/min). The reaction mixture was heated at 165 °C for 3 hours. The product reaction mixture containing a white slurry product was then cooled to about 130 °C and poured into 100 mL of water in a beaker cooled in an ice water bath. The white slurry was filtered off, washed by water (50 mL x 3), and dried to yield fine crystals at 76% yield. The product had a 4:1 phosphorus to aluminum ratio (ICP Elemental Analysis) according to the following empirical formula:

Example 7 - Flame Retardant

A three-neck 250 mL flask was charged with 114.6 g methylphosphonic acid, which was then heated. At 105 °C the methylphosphonic acid melts, and vigorous stirring was begun under a N₂ blanket. The methylphosphonic acid was heated to 240 °C and 7.78 g of alumina was added as quickly as possible without causing a large exotherm. The slurry was cooled until it was just above the melting point of the excess methyl phosphonic acid, ~110 °C, and then added to 250 mL of H₂O while ensuring that the rate of addition did not cause excessive steam formation. The resulting mixture was agitated to break up any large clumps that might have formed, the product was isolated by filtration, washed with an additional 750 mL of H₂O, and dried to yield 45.08 g of the product as fine colorless crystals at 87% yield. The product empirical formula above represents repeating monomer units (i.e., coordination entities) of a coordination polymer forming the pure crystalline product.

Example 8 - Flame Retardant

A three-neck 250 mL flask was charged with 149.8 g ethylphosphonic acid, which was heated to melting, 62 °C. Vigorous stirring was begun under a N₂ blanket, the ethylphosphonic acid was heated to 240 °C and 6.9 g of alumina was added as quickly as possible without causing a large exotherm. The slurry was cooled to ~80 °C, and then added to 250 mL of H₂O while ensuring that the rate of addition did not cause excessive steam formation. The resulting mixture was agitated to break up any large clumps that might have formed, the product was isolated by filtration, washed with an additional 750 mL of H₂O, and dried to yield 49.07 g of the product as fine colorless crystals at 84% yield. The product empirical formula above represents repeating monomer units (i.e., coordination entities) of a coordination polymer forming the pure crystalline product.

Example 9 - Flame Retardant

A resin kettle was charged with 83 g of methylphosphonic acid, which was heated to 120 °C. An intermediate material prepared from 50 g. methyl phosphonic acid and 35.4 g. aluminum tris(isopropoxide) in the presence of water was added to the resin kettle as a syrup. The resulting solution contained a 5:1 molar ratio of methylphosphonic acid : aluminum methylphosphonic acid intermediate, which was heated to 240 °C with mechanical stirring. Stirred continued at 240 °C for about 30 min after a solid had formed. 500 ml_ of H₂O was added and the mixture was stirred for 16 h while a uniform slurry was made. As above, the product was isolated by filtration, washed with an additional 750 mL of H₂O, and dried to yield 64.3 g of the product as fine colorless crystals at 93% yield. The product empirical formula above represents repeating monomer units (i.e., coordination entities) of a coordination polymer forming the pure crystalline product. Example 10 - Flame Retardant

A three-neck 1 L flask was charged with 1305 g methylphosphonic acid, which was then heated. At 105 °C the methylphosphonic acid melted, and vigorous stirring was begun under vacuum. The methylphosphonic acid was heated to 180 °C and 61 g of alumina was added as quickly as possible without causing a large exotherm or excessive foaming. The slurry was cooled until it was just above the melting point of the excess methyl phosphonic acid, ~110 °C, and then added to 1 L of H₂O while ensuring that the rate of addition did not cause excessive steam formation. The resulting mixture was agitated to break up any large clumps that might have formed, and the product was isolated by filtration, washed with an additional 1 .5 L of H₂O, and dried to yield 408 g of the product as fine colorless crystals at 84% yield. The product empirical formula above represents repeating monomer units (i.e., coordination entities) of a coordination polymer forming the pure crystalline product.

The products from each of Examples 7-10 had a 4:1 P to Al ratio (ICP Elemental Analysis).

Example 11 - Flame Retardant

A 1 L reaction vessel was charged with 1412.6 g methylphosphonic acid, which was then heated to 165 °C under nitrogen purge (4L/min) at 250 RPM stirring. 78.2 g of iron oxide was added in portions without causing a large exotherm. The reaction mixture was heated at 165 °C for about 24 hours. The product reaction mixture containing an off-white slurry product was then cooled to about 130 °C and poured into 1.5 L of water in a beaker cooled in an ice water bath. The product was isolated by filtration, washed with an additional 500 mLx3 of water, and dried to yield fine off-white color crystals at 83% yield. The product had a 4:1 phosphorus to iron ratio (ICP Elemental Analysis) according to the following empirical formula:

Example 12 - Preparation of Methylpyrophosphonic acid °

Methylposphonic acid (MPA) (1920g, 15eq, fresh aq. sol. 75%) and AI₂O₃ (0.8g, 7.5 mmol, 0.05 mol% base on total MPA) were put in a 2 L RBF at room temperature with magnetic stir bar. It was heated carefully to remove the solvent water (pot set to 200 °C), and then carefully pulling vacuum to remove the water generated from the reaction. The target end point is 33% conversion.

Hour 1 , pot set @ 200 °C, vacuum started @ 19.4 Torr, end @ 14.2 Torr, conversion 34.1%

Example 13 - Aluminum in Methylphosphonic acid Solution

AI₂O₃, H₂O, 75% MPA Al in MPA solution

130 °C, 100 RPM, Vac

MPA (1024g, 8eq, fresh aq. sol. 75%) and AI₂O₃ (50.2 g, total 0.50mol, 1.0eq, combining with catalytical amount from Example 2) were mixed at room temperature in a 3L reactor. The pot temperature was set to 130 °C at 100 RPM without nitrogen purge. The pot temperature was stable around 110 degree C for about 1 hour, while the white slurry turned into opaque and then a clear pale yellow solution. After the pot temperature became stable at 130 °C, kept the reaction mixture at 130 °C overnight. The second morning, carefully pulled vacuum to remove water while set up the pot temperature to 200 °C, and the house vacuum was stable at 57 Torr in the end till no distillate coming out.

Example 14- Flame Retardant

Methylpyrophosphonic acid product of Example 12 was preheated to 205 °C and a seeding material (1.9 g, 0.5 wt% of the theoretical amount of the flame retardant) was added to it. The preheated methylpyrophosphonic acid was then poured the 200 °C solution of Example 13 at 300 RPM. After mixing, the reaction was kept at 200 °C for 5 min. The reaction mixture was then cooled to 130 °C and poured slowly and carefully into 2.8L water in a 4L beaker at room temperature and stirred at 250 RPM for 10 min. The white slurry was filtered off and dried over house vacuum for 4 hours. The solid was then transferred to a beaker and stirred with 700 mL water for 10 min and suction dried with the house vacuum overnight. The crude yield was 83.0%, 100 mesh at 99 min sifting yield was 94.0%.

The resulting material had Acid # < 0.1 mg KOH/g sample and 4:1 P to Al ratio (ICP Elemental Analysis).

Example 15 - Flame Retardant

MPA (1553g, 12eq, sol. 75%aq) was put in a 3L resin reactor. It was heated carefully to remove water (pot set to 200 °C, 150 RPM), carefully pulling vacuum when there was not distillate coming out. Target end point of conversion is 71% (31P NMR measurement, set MPA 100 %). Day 2, pot set @ 200 °C, vacuum @ 150 Torr, 37.2% conversion; Day 3, pot set @ 200 °C, vacuum @ 200 Torr, 54.4% conversion; Day 4, pot set @ 200 °C, vacuum @ 120 Torr, 69.1% conversion to pyrophosphonic acid.

1.

O pot set @ 200°C O O p p off vacuum HO |'‘CT | ^OH

Separately, MPA (768g, 6eq, fresh aq. sol. 75%) and AI2O3 (51.0g, 0.50mol, 1.0eq) were mixed at room temperature. The pot temperature was set to 130 °C first, at 250 RPM without nitrogen purge. The pot temperature stabled around 110 degree C for about 1 hour, while the white slurry turned into opaque and then the clear pale yellow solution. The pot temperature then set to 200 °C. Carefully pulling vacuum to remove water with vacuum stable at 140 Torr in the end till no distillate coming out.

2. o AI₂O₃, H₂O, 75% MPA ~ _{A| in MPA} o ^H 200 °C, 250 RPM, 140 Torr solution

The pyrophosphonic acid was preheated to 200 °C and then mixed at 200 °C and 250 RPM with the Al in MPA solution. No seeding material was needed and the slurry stayed. The reaction mixture was kept at 200 °C for 3 hour. The reaction mixture was then poured slowly and carefully into 2.8L water in a 4L beaker at room temperature and stirred at 250 RPM for 10 min. The white slurry was filtered off and dried over house vacuum for 4 hours. The solid was then transferred to a beaker and stirred with 700 mL water for 10 min and suction dried with house vacuum overnight. The crude yield was 88.7%. The SEM showed that the product was in needle form. The material was further dried in 60 °C oven and sift through 100 Mesh sieves (67.5% @ 99 min; 97.2% @ 198 min).

Example 16 - Polymer Compositions

The presently disclosed flame retardant and colorant combined was evaluated in polyamide- 6,6 thermoplastic compositions. The ingredients are listed below and shown in Table 2, including the ratios of the blended components.

Thermoplastic polymer:

Polyamide-6,6 (PolyNil® P-50/2 from Nilit)

Inorganic filler:

Glass fiber (ChopVantage® 3540 from PPG)

Phosphorus-containing flame retardant (Phos-FR):

Phos-FR produced according to Example 7 above

OP 1312

Colorant

Macrolex® Orange HT from LANXESS

Flame retardant synergist:

Melam or melamine polyphosphate (MPP)

Stabilizer:

Zinc borate A Liestritz 18 mm twin screw extruder was used to compound the formulations shown in Table 1 at 265°C and 200 rpm. AVandorn 55 candence injection molder was used to prepare 0.8 mm (thickness) samples for each formulation at 260-280°C and a mold temperature at 80°C. Each prepared formulation was evaluated for flame retardant activity under UL-94 testing and the molecular weight of the polymer was determined by gel permeation chromatography (GPC).

Table 2

As shown in Table 1 , all formulations containing colorant exhibited V-0 performance under UL-94 testing. However, when comparative flame retardant OP 1312 was used, the injection molding process was unstable. Even narrower process window was observed when orange colorant was added to the comparative flame retardant (formulation 3). In contrast, much more stable injection molding process was observed with formulations 1 ,2, 5 and 6 containing flame retardant according to the disclosure, specifically, formulation 1 and 5 are showed more stable injection molding process than these counter parts, formulation 2 and 6. All these indicating less polymer degradation cause by flame retardant additives and colorant. The inclusion of colorant in formula 1 and 5 results in less energy consumption than the formulations without (2 and 6) also provides a broader process window for injection molding process.

Example 17 - Polymer Compositions

The presently disclosed flame retardant and colorant combined can be combined in polyamide-6 thermoplastic compositions. The ingredients are listed below and shown in Table 2, including the ratios of the blended components.

Thermoplastic polymer:

Polyamide-6 (Durethan® B30S from LANXESS)

Inorganic filler:

Glass fiber (ChopVantage® 3540 from PPG)

Phosphorus-containing flame retardant (Phos-FR):

Phos-FR produced according to Example 7 above

Additional flame retardant:

Polydibromostyrene (Firemaster® PBS-64HW from LANXESS)

Carbodiimide:

Aromatic polycarbodiimide of formula (VI) above (Stabaxol® P100 from LANXESS)

A twin-screw extruder can be used to compound the formulations shown in Table 3 at 255- 265°C. An injection molder is used to prepare 1 .6 mm (thickness) samples for each formulation at 245-255°C and a mold temperature at 80°C.

Table 3

Example 18 - Polymer Compositions

Alternative polyamide-6,6 thermoplastic compositions are provided below. The ingredients are listed below and shown in Table 4, including the ratios of the blended components.

Thermoplastic polymer:

Polyamide-6,6 (PolyNil® P-50/2 from Nilit)

Inorganic filler:

Glass fiber (ChopVantage® 3540 from PPG)

Phosphorus-containing flame retardant (Phos-FR):

Phos-FR produced according to Example 7 above

Flame retardant synergist:

Melam

Heat Stabilizer:

Zinc Stannate (Flamtard S from William Blythe)

Carbodiimide:

Aromatic polycarbodiimide of formula (VI) above (Stabaxol® P100 from LANXESS)

A twin screw extruder is used to compound the formulations shown in Table 4 at 265°C. An injection molder is used to prepare 0.8 mm (thickness) samples for each formulation at 260- 280°C and a mold temperature at 80°C.

Table 4

Although particular embodiments of the present invention have been illustrated and described, it will be apparent to those skilled in the art from consideration of the specification and practice of the present disclosure that various modifications and variations can be made without departing from the scope of the invention, as claimed. Thus, it is intended that the specification and examples be considered as exemplary only, with a true scope of the present invention being indicated by the following claims and their equivalents.

Claims

What is claimed is:

1 . A flame retardant and colorant additive composition, for thermoplastic polymers, comprising

is a metal cation where (+)y represents the charge formally assigned to the cation, a, b, and c represent the ratio of the components to which they correspond relative to one another in the compound, and satisfy the chargebalance equation 2(a)+c=b(y), and a and c are not zero, and

(B) an orange colorant.

2. The flame retardant and colorant additive composition of claim 1 , wherein in the empirical formula (I), a is 1 or 2, b is from 1 to 4 and c is 1 or 2.

3. The flame retardant and colorant additive composition of claim 1 , wherein y is 3, a is 1 , b is 1 and c is 1 .

4. The flame retardant and colorant additive composition of claim 3, wherein M is chosen from Al, Ga, Sb, Fe, Co, B, and Bi.

5. The flame retardant and colorant additive composition of claim 4, wherein M is Al or Fe.

6. The flame retardant and colorant additive composition of any one of claims 1-5, wherein in the empirical formula (I) R is C1-12 alkyl, C₆-io aryl, C7-18 alkylaryl, or C₇-is arylalkyl, wherein the alkyl, aryl, alkylaryl, or arylalkyl are unsubstituted or are substituted by halogen, hydroxyl, amino, C- alkylamino, di-Ci.4 alkylamino, C1-4 alkoxy, carboxy or C2-5 alkoxycarbonyl.

7. The flame retardant and colorant additive composition of claim 6, wherein R is unsubstituted C1-12 alkyl, Ce aryl, C7-10 alkylaryl, or C7-10 arylalkyl.

8. The flame retardant and colorant additive composition of claim 6, wherein R is unsubstituted Ci.₆ alkyl.

9. The flame retardant and colorant additive composition of claim 8, wherein R is chosen from methyl, ethyl, propyl, isopropyl, butyl, and t-butyl.

10. The flame retardant and colorant additive composition according to any one of claims 1-9, wherein M is Al, y is 3, a is 1 , b is 1 and c is 1.

11 . The flame retardant and colorant additive composition of claim 10, wherein R is Ci-₆ alkyl.

12. The flame retardant and colorant additive composition of claim 11 , wherein R is chosen from methyl and ethyl.

13. The flame retardant and colorant additive composition of claim 1 further comprising

(C) at least one flame retardant synergist and/or additional flame retardant.

14. The flame retardant and colorant additive composition of claim 13, wherein component (C) comprises a nitrogen-containing flame retardant synergist.

15. The flame retardant and colorant additive composition of claim 1 , further comprising

(D) one or more stabilizers.

16. A flame retardant thermoplastic composition comprising at least one thermoplastic polymer and the flame retardant and colorant additive composition according to any one of claims 1-15, wherein the thermoplastic composition has a AE of <20, preferably a AE<10, more preferably AE<5, from a color number beginning with “2” in the RAL color chart.

17. The flame retardant thermoplastic composition of claim 16, wherein the at least one thermoplastic polymer is chosen from the group consisting of polyesters and polyamides.

18. The flame retardant thermoplastic composition of claim 17, wherein the at least one thermoplastic polymer is a polyamide chosen from the group consisting of polyamide-4,6, polyamide-6, polyamide-6,6, polyamide-6,10, polyamide-6,12, polyamide-11 , polyamide-12, polyamide-4,T, polyamide-MXD,6, polyamide-12, T, polyamide-10,T, polyamide-9,T, polyamide-6, T/6, 6, polyamide-6, T/D,T, polyamide-6, 6/6, T/6, 1, polyamide-6/6,T, polyamide- 6, T/6, 1, and mixtures thereof.

19. The flame retardant thermoplastic composition of claim 16, further comprising at least one inorganic filler.

20. The flame retardant thermoplastic composition of claim 19, wherein the inorganic filler comprises glass fiber.

21 . A method of improving processing of a thermoplastic polymer comprising adding to the thermoplastic polymer the flame retardant and colorant additive composition of any of claims 1-15.

22. The method of claim 21 , wherein the thermoplastic polymer is chosen from the group consisting of polyesters and polyamides.

23. The method of claim 21 , wherein the thermoplastic polymer is a polyamide chosen from the group consisting of polyamide-4,6, polyamide-6, polyamide-6,6, polyamide-6,10, polyamide-6,12, polyamide-11 , polyamide-12, polyamide-4,T, polyamide-MXD,6, polyamide- 12,T, polyamide-10,T, polyamide-9,T, polyamide-6,T/6,6, polyamide-6,T/D,T, polyamide- 6,6/6,T/6,l, polyamide-6/6,T, polyamide-6,T/6,l, and mixtures thereof.

24. The method of claim 21 , further comprising adding at least one inorganic filler to the thermoplastic polymer.

25. The method of claim 24, wherein the inorganic filler comprises glass fiber.

26. The method of claim 21 , wherein the processing is an injection molding process.