New phenylphosphonic acid esters and use thereof as flame retardants

Abstract

The invention relates to a new class of phenylphosphonic acid esters combining good flame-retardant properties with a high plasticizing effect and ease of applicability.

Description

[0001] POOL 01247 A

[0002] - 1 -

[0003] New phenylphosphonic acid esters and their use as flame retardants

[0004] Phosphoric acid esters are widespread and versatile industrial products used in various applications. For example, they are components or additives in plastics, hydraulic fluids, lubricants, heat transfer fluids, paints, adhesives, sealants, and coatings. However, doubts have been growing for some time as to whether these substances still meet current product safety requirements. Therefore, especially in consumer applications, there is an increasing demand for alternatives based on different chemical structures.

[0005] In plastics, established phosphoric acid esters are used as plasticizers and flame retardants. For example, they are used to produce flame-retardant flexible PVC for floor coverings, seals, hoses, or cables. It is essential that the phosphorus compound used exhibits both plasticizing and flame-retardant properties in PVC.

[0006] In addition to the classic phosphoric acid esters, phenylphosphonic acid diesters are also known to experts as flame retardants and / or plasticizers in various plastics. For example, phenylphosphonic acid diaryls have been used in ABS polymers (J. Macromol. Sei., Part B 2012, 51, 2141-2156), in epoxy resins (J. Appl. Polym. Sei. 2015, 132, 42765) and in polycarbonates (US 2009 149587 A1).

[0007] The use of phenylphosphonic acid diphenyl ester and related phosphonates as flame retardants and plasticizers is mentioned in EP 0043482 A2, without any details or test results being given.

[0008] Phenylphosphonic acid bis(2-ethylhexyl) ester is known from US 2,400,577 A. There, it is described as suitable for use as a plasticizer, without any mention of flame-retardant properties.

[0009] CN 116396573 A describes phenylphosphonic acid diaryl esters as plasticizing flame retardants in PVC. Cardanol is used as a raw material for the production of these products and is reacted with phenylphosphonic acid dichloride to form a mixture of phenylphosphonic acid diaryl esters. The plasticizing effect of these products is attributed to the C15 side chain of cardanol. Due to the associated high molar mass of cardanol, the products described therein exhibit POOl 01247 A

[0010] - 2 - has a very low phosphorus content of less than 4.5 wt%. In practice, such a low phosphorus content means that further flame-retardant additives must be added to achieve the desired flame-retardant effect in addition to the plasticizing effect. Therefore, when testing the phosphonates according to the invention, the inventors exclusively use formulations containing other flame retardants, such as montmorillonite, anhydrite, and chlorinated polyethylene. This complex formulation represents a considerable additional technical effort. Furthermore, mineral flame retardants negatively affect the transparency of the PVC compound, which is undesirable for some demanding applications. Another disadvantage of the invention is that Cardanol is currently not available on the market in technically relevant quantities.

[0011] In addition to phenylphosphonic acid diaryl esters, halogenated phenylphosphonic acid dialkyl esters are also described in the prior art. For example, halogenated phenylphosphonic acid dialkyl esters are used as plasticizing flame retardants in PVC in CN 105601660 A, CN 105713039 A, and CN 10571340 A. However, the use of halogenated flame retardants is no longer accepted by the market after numerous brominated and chlorine-containing flame retardants, such as brominated diphenyl ethers or tris(chloroethyl) phosphate, had to be withdrawn from the market in many countries due to significant toxic effects on humans and the environment.

[0012] To overcome the aforementioned disadvantages of the prior art, halogen-free phenylphosphonic acid esters are desirable, which exhibit good flame-retardant properties in thermoplastic molding compounds, especially in PVC, while simultaneously showing good plasticizing properties.

[0013] The object of the present invention was therefore to provide halogen-free phenylphosphonic acid esters that exhibit a high flame-retardant effect in thermoplastic molding compounds, particularly PVC, while simultaneously exhibiting a high plasticizing effect. Since the PVC processing industry is geared towards handling liquid plasticizers, it would be additionally advantageous if the substances sought were available as low-viscosity liquids at room temperature (23 °C). POOl 01247 A

[0014] - 3 -

[0015] The problem is solved by phenylphosphonic acid esters of the general formula (I) wherein R represents a branched or unbranched C6-C12 alkyl, alkenyl, akinyl or aralkyl residue and Ar represents a phenyl or C1-C4 alkyl phenyl residue.

[0016] Preferably, R in formula (I) represents a branched or unbranched C8-C10 alkyl, alkenyl, akinyl or aralkyl group and Ar represents a phenyl group or a cresyl group, particularly preferably a phenyl group.

[0017] A preferred embodiment of the invention relates to phenylphosphonic acid ester mixtures containing:

[0018] (i) 20 to 99 wt% phenylphosphonic acid esters according to formula (I)

[0019] (ii) 0.5 to 50 wt% phenylphosphonic acid esters according to formula (II), as well as

[0020] (iii) 0.5 to 50 wt% phenylphosphonic acid esters according to formula (III) each refers to the total amount of phenylphosphonic acid esters, where R and Ar have the meanings mentioned above.

[0021] In a particularly preferred embodiment of the invention, the phenylphosphonic acid ester mixtures contain

[0022] (i) 30 to 70 wt% phenylphosphonic acid esters according to formula (I)

[0023] (ii) 10 to 40 wt% phenylphosphonic acid esters according to formula (II), as well as

[0024] (iii) 10 to 40 wt% phenylphosphonic acid esters according to formula (III), in each case based on the total amount of phenylphosphonic acid esters, where R and Ar have the meanings given above. POOl 01247 A

[0025] - 4 -

[0026] In a further particularly preferred embodiment of the invention, the phenylphosphonic acid ester mixtures contain

[0027] (i) 40 to 60 wt% phenylphosphonic acid esters according to formula (I)

[0028] (ii) 20 to 30 wt% phenylphosphonic acid esters according to formula (II), as well as

[0029] (iii) 20 to 30 wt% phenylphosphonic acid esters according to formula (III), in each case based on the total amount of phenylphosphonic acid esters, where R and Ar have the meanings mentioned above.

[0030] In an alternative embodiment of the invention, the phenylphosphonic acid ester mixtures contain

[0031] (i) 80 to 95 wt% phenylphosphonic acid esters according to formula (I)

[0032] (ii) 0.5 to 5 wt% phenylphosphonic acid esters according to formula (II), as well as

[0033] (iii) 4.5 to 15 wt% phenylphosphonic acid esters according to formula (III), in each case based on the total amount of phenylphosphonic acid esters, where R and Ar have the meanings mentioned above.

[0034] In a preferred embodiment, R in formula (I) or formula (III) represents n-hexyl, iso-hexyl, cyclohexyl, n-heptyl, iso-heptyl, n-octyl, 2-ethylhexyl, iso-octyl, n-nonyl, iso-nonyl, n-decyl, 2-propylheptyl, iso-decyl, n-dodecanyl, iso-dodecanyl, or mixtures thereof. In a particularly preferred embodiment of the invention, R in formula (I) or formula (III) represents 2-ethylhexyl, n-octyl, 2-propylheptyl, n-decyl, or iso-decyl.

[0035] In a preferred embodiment, Ar in formula (I) or formula (II) represents phenyl, o / m / p-cresyl, o / m / pn-propylphenyl, o / m / p-isopropylphenyl, o / m / pn-butylphenyl, o / m / p-isobutylphenyl, o / m / p-sec-butylphenyl, o / m / p-tert-butylphenyl, thymyl (2-isopropyl-5-methylphenyl), guaiacyl (2-methoxyphenyl), mequinyl (4-methoxyphenyl), or mixtures thereof. Here, "o / m / p" means that the residue can be an ortho, meth, or para isomer. In a particularly preferred embodiment of the invention, Ar in formula (I) or formula (II) represents phenyl, m-cresyl, p-cresyl, or 4-tert-butylphenyl. In a most preferred embodiment of the invention, Ar represents phenyl.

[0036] The phenylphosphonic acid ester mixtures according to the invention preferably consist of phenylphosphonic acid esters, particularly preferably of phenylphosphonic acid esters of formulas (I) to (III), wherein R and Ar have the meanings mentioned above. POOl 01247 A

[0037] - 5 -

[0038] Preferably, the phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to the invention are present as a liquid at 23°C, since such a state facilitates or even enables their use as flame retardants. Preferably, the phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to the invention have a dynamic viscosity of 5 to 5000 mPa s, particularly preferably of 5 to 2000 mPa s, and most preferably of 5 to 500 mPa s (in each case at 23°C).

[0039] Preferably, the phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to the invention have a low acid number, since high acid numbers can negatively affect the long-term stability of the plastic used, for example, PVC. Preferably, the phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to the invention have an acid number of less than 5 mg KOH / g, preferably less than 1 mg KOH / g, particularly preferably less than 0.3 mg KOH / g, and most preferably between 0.1 mg and 0.0 mg KOH / g.

[0040] The phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to the invention can be prepared by known synthesis methods (see e.g. Langmuir 1996, 12, 3881).

[0041] The phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to the invention can be used in combination with other excipients, depending on the application. Examples of excipients include plasticizers, plasticizing polymers, polymeric modifiers, stabilizers (e.g., thermostabilizers, light stabilizers, antioxidants), co-stabilizers (e.g., acid scavengers, radical scavengers), internal and external lubricants, viscosity regulators, fillers, color pigments, dyes, flame retardants, flame retardant synergists, blowing agents, and other functional additives such as antistatic agents, nucleating agents, UV stabilizers, or biocides (see, e.g., RD ​​Maier, M. Schiller, Handbuch Kunststoff-Additive [Handbook of Plastic Additives], 4th edition, Munich, Carl Hanser Verlag, 2016, pp. 513 ff).

[0042] Typical plasticizers that can be used together with the phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to the invention are carboxylic acid esters, for example, esters of benzoic acid or diesters of adipic acid, sebacic acid, azelaic acid, phthalic acid, terephthalic acid, or 1,2-cyclohexanedicarboxylic acid, or polyesters of these diaacids. Other typical plasticizers are alkylsulfonic acid esters of phenol. POOl 01247 A

[0043] - 6 -

[0044] Another aspect of the invention is therefore phenylphosphonic acid ester mixtures which, in addition to the phenylphosphonic acid esters of formulas (I) to (III) according to the invention, contain 0.1 to 70 wt.%, preferably 0.5 to 50 wt.%, more preferably 1.0 to 35 wt.% and most preferably 2.0 to 25 wt.% of the above excipients.

[0045] The phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to the invention are suitable as flame retardants. A further object of the present invention is therefore their use as flame retardants.

[0046] The phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to the invention can be used as flame retardants in all applications known to those skilled in the art. They are preferably used as flame retardants for synthetic polymers such as polyolefins, polyvinyl chloride, polycarbonates, styrene-based (co-)polymers, polyamides, polyesters, polyurethanes, elastomers such as NBR, CR, SBR, or EPDM, and thermosets such as epoxy resins, unsaturated polyester resins and phenol-formaldehyde resins, cellulose esters, and polylactic acid.

[0047] - Materials of plant origin, such as wood, wood-plastic composites, paper and cardboard, and

[0048] - Materials of animal origin, such as leather, are used.

[0049] The phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to the invention are particularly preferably used as flame retardants for polyvinyl chloride (PVC), for example in PVC molding compounds, i.e. in compositions containing PVC which are in the form of granules, a powder, a paste, a plastisol or organosol.

[0050] The invention therefore also relates to compositions, preferably in the form of granules, powder, paste, or plastisol, containing phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to the invention and polyvinyl chloride (PVC). These PVC molding compounds according to the invention are preferably flexible PVC. POOl 01247 A

[0051] - 7 -

[0052] The PVC molding compounds according to the invention can be produced by mixing and compounding PVC with the phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to the invention and optionally further auxiliary substances, e.g. stabilizers, in a manner known per se (see e.g. G. Becker, D. Braun, Kunststoff-Handbuch, Polyvinylchlorid, Vol. 2 / 2, Munich, Vienna, Carl Hanser Verlag, 1986, p. 829 ff) or by dispersing it to a plastisol or organosol ready for processing.

[0053] The PVC molding compound according to the invention preferably contains 5 to 150 parts by weight, preferably 10 to 120 parts by weight, preferably 20 to 100 parts by weight, particularly preferably 30 to 70 parts by weight of the phenylphosphonic acid esters of formulas (I) to (III) according to the invention, based on 100 parts by weight of PVC.

[0054] The PVC molding compound according to the invention is used in coatings, films, floor coverings, cables, pipes, hoses, seals, conveyor belts, roofing membranes, adhesive tape films, tarpaulins, awnings and tents.

[0055] A further aspect of the invention is the use of the phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to the invention in hydraulic fluids or for the production of hydraulic fluids. The phenylphosphonic acid esters according to the invention are preferably used in flame-retardant hydraulic fluids.

[0056] A further aspect of the invention is the use of the phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to the invention as lubricant additives. The phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to the invention are preferably used in flame-retardant lubricants.

[0057] Another object of the invention is the use of the phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to the invention as an additive for paints, adhesives, sealants and coatings.

[0058] A further aspect of the invention is the use of the phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to the invention as heat transfer fluids or in preparations used as heat transfer fluids. The phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to the invention are preferably used as heat transfer fluids or as additives for heat transfer fluid preparations. P001 01247 A

[0059] - 8 - for example, for the immersion cooling of electrical components. In addition to the phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to the invention, the heat transfer fluid preparations contain, for example, trialkyl phosphates, triaryl phosphates, mineral oils, polyalphaolefins, esters, antioxidants, metal deactivators, flow additives, corrosion inhibitors, foam inhibitors, demulsifiers and / or pour point reducers.

[0060] Another object of the invention is the use of the phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to the invention as solvents or extraction agents.

[0061] POOL 01247 A

[0062] - 9 -

[0063] Determination of the composition of phenylphosphonic acid esters

[0064] The composition of the phenylphosphonic acid esters was determined using 31The values ​​were determined by 13P NMR spectroscopy. The NMR measurements were performed on an 80 MHz Magritek Spinsolve™ 80 Phosphorus spectrometer. The reaction mixture samples were measured undiluted. Proton-decoupled spectra were used for quantification.

[0065] Determination of the viscosity of phenylphosphonic acid esters

[0066] The dynamic viscosity of phenylphosphonic acid esters was measured using an Anton Paar shear rheometer of type MCR 102 at the specified temperature with a shear rate of 200 s⁻¹. -1 according to DIN 53018.

[0067] Determination of the acid number of phenylphosphonic acid esters

[0068] The acid value of the samples was determined according to DIN EN ISO 2114 (Method B, colorimetric titration with phenolphthalein). For this purpose, the sample (10 g) was weighed out, dissolved in acetone (200 mL) and water (50 mL), and 2-3 drops of a phenolphthalein solution (0.1 wt% in ethanol / water (v / v = 4 / 1)) were added. Sodium hydroxide solution (0.1 mol / L) was titrated from a burette until the color change from colorless to pink persisted for at least 10 seconds while stirring. A blank value was measured in the same manner, but without the sample.

[0069] Synthesis example 1 (according to the invention)

[0070] Following a known procedure (Langmuir 1996, 12, 3881), a mixture of 2-ethylhexanol (0.68 parts by weight), triethylamine (0.60 parts by weight), and toluene (3.5 parts by weight) was placed in a reactor equipped with a stirrer, internal thermometer, nitrogen inlet, and reflux condenser. Phenylphosphonic acid dichloride (1.00 parts by weight) was added at 20°C. After the addition was complete, the mixture was stirred for another hour, and a solution of phenol (0.49 parts by weight), triethylamine (0.60 parts by weight), and toluene (3.5 parts by weight) was added at 20°C. After the addition was complete, POOl 01247 A

[0071] - 10 -

[0072] The mixture was stirred for another hour after dosing. To work up the reaction mixture, it was diluted with water, the phases were separated, and the solvent was removed by distillation. The crude product was washed twice successively with sodium hydroxide solution (1 mol / L) and three times with water. After drying under vacuum, the product was isolated as a low-viscosity liquid (32 mPa s at 23°C). The acid value was <0.1 mg KOH / g. The product contained 54 wt% phenylphosphonic acid (phenyl)(2-ethylhexyl) ester, 25 wt% phenylphosphonic acid bis(2-ethylhexyl) ester, and 21 wt% phenylphosphonic acid diphenyl ester.

[0073] Synthesis example 2 (comparative example)

[0074] In a reactor equipped with a stirrer, internal thermometer, nitrogen inlet, and reflux condenser, a mixture of 2-ethylhexanol (1.36 parts by weight), triethylamine (1.20 parts by weight), and toluene (7.0 parts by weight) was placed and treated with phenylphosphonic dichloride (1.00 parts by weight) at 20°C. After the dose was added, the mixture was stirred for one hour. To work up the reaction mixture, it was diluted with water, the phases were separated, and the solvent was removed by distillation. The crude product was washed twice successively with sodium hydroxide solution (1 mol / L) and three times with water. After drying, the product was isolated as a low-viscosity liquid (20 mPa s at 23°C). The acid number was <0.1 mg KOH / g. The product contained >99.9 wt% phenylphosphonic bis(2-ethylhexyl) ester.

[0075] Synthesis example 3 (comparative example)

[0076] In a reactor equipped with a stirrer, internal thermometer, nitrogen inlet, and reflux condenser, a mixture of phenol (0.98 parts by weight), triethylamine (1.20 parts by weight), and toluene (7.0 parts by weight) was placed and treated with phenylphosphonic dichloride (1.00 part by weight) at 20°C. After the addition of the phenylphosphonic dichloride, the mixture was stirred for one hour. The reaction mixture was then diluted with water and the phases separated. The crude product was washed twice successively with sodium hydroxide solution (1 mol / L) and three times with water. After removal of the solvent by distillation, the product was isolated as a white solid. The acid number was 0.4 mg KOH / g, and the melting point was 74°C. The product contained >99.9 wt% phenylphosphonic diphenyl ester.

[0077] The compositions of the prepared phenylphosphonic acid esters are summarized again in Table 1. POOl 01247 A

[0078] - 11 -

[0079] Table 1: Composition of prepared phenylphosphonic acid esters.

[0080] Production of flexible PVC

[0081] The flexible PVC molding compounds used for testing were produced on a laboratory rolling mill. After adding the mixture of all formulation components (see Table 2), it was left on the roller until a film formed. From the point of film formation, the compounds were compounded for another 10 minutes on the rolling mill and finally removed as rolled film. The rolling temperature was 165°C.

[0082] The test specimens for determining the LOI were produced from the roller skins using a press. The pressing temperature was 170°C, the pressing time was 4 minutes for preheating at low pressure (< 10 bar) and 2 minutes at high pressure (> 100 bar). Test specimens with dimensions of 90 x 13 x 4 mm were sawn from the 4 mm thick press plates.

[0083] The test specimens used to determine the hardness of the compounds (50 x 40 x 6 mm) were pressed for a longer period at the same temperature due to their large thickness of 6 mm. The pressing time was 7 minutes for preheating at low pressure and 3 minutes for compression pressing at high pressure. POOl 01247 A

[0084] - 12 -

[0085] Table 2: Ingredients for the production of flexible PVC.

[0086] PVC samples were produced according to this regulation.

[0087] Determination of flame retardancy

[0088] The Limiting Oxygen Index (LOI) was used to assess flame retardancy. The LOI is a measure of the fire behavior of plastics and other materials. It represents the minimum oxygen concentration in a nitrogen / oxygen mixture below which combustion of a test specimen can still occur under standardized conditions. The higher the LOI, the greater the effectiveness of the flame retardant. The test was conducted according to ISO 4589-2.

[0089] Determination of the plasticizer effect

[0090] The plasticizing effect of phosphoric acid esters was determined by measuring the Shore A hardness of phosphoric acid ester-containing soft PVC compounds. The measurement principle is based on the penetration depth of a metal probe into the material sample for 15 seconds with a force of 12.5 N. The Shore A hardness was determined for test specimens with dimensions of 50 x 40 x 6 mm. The Shore hardness measurement was performed in accordance with DIN ISO 7619-1.

[0091] The measurement results are summarized in Table 3. POOl 01247 A

[0092] - 13 -

[0093] Table 3: Determination of the flame retardancy and Shore A hardness of the manufactured PVC

[0094] Pattern The results show that the PVC compound containing the phenylphosphonic arylalkyl ester S1 according to the invention achieves both good flame-retardant properties (high LOI) and good plasticizing properties (low Shore A hardness). In contrast, the PVC compound containing the phenylphosphonic dialkyl ester S2 known from US 2,400,577 A does not exhibit sufficient flame retardancy. The PVC compound containing the phenylphosphonic dialkyl ester S3 known from EP 0043482 A2 is not sufficiently plasticized. Furthermore, the PVC processing industry is geared towards handling liquid plasticizers and would not process the solid product from S3, or would do so only reluctantly.

Claims

POOL 01247 A - 14 - 1. Phenylphosphonic acid esters of general formula (I) wherein R represents a branched or unbranched C6-C12 alkyl, C6-C12 alkenyl, C6-C12 alkynyl or C6-C12 aralkyl group and Ar represents a phenyl or C1-C4 alkyl phenyl group substituted with a phenyl group.

2. Phenylphosphonic acid esters according to claim 1, wherein Ar represents phenyl, cresyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, sec-butylphenyl, tert-butylphenyl, thymyl (2-isopropyl-5-methylphenyl), guaiacyl (2-methoxyphenyl), mequinyl (4-methoxyphenyl), preferably phenyl, m-cresyl, p-cresyl or 4-tert-butylphenyl and particularly preferably phenyl.

3. Phenylphosphonic acid esters according to claim 1 or 2, wherein R represents n-octyl, iso-octyl, 2-ethylhexyl, n-decyl, or iso-decyl, preferably 2-ethylhexyl.

4. Containing mixtures of phenylphosphonic acid esters (i) 30 to 99 wt% phenylphosphonic acid esters according to one or more of claims 1 to 3 (ii) 0.5 to 50 wt% phenylphosphonic acid esters according to formula (II) (iii) 0.5 to 50 wt% phenylphosphonic acid esters according to formula (III) each based on the total amount of phenylphosphonic acid esters, wherein R and Ar have the meanings specified in claims 1 to 3. POOL 01247 A - 15 - 5. Phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to claims 1 to 4 having an acid number of less than 5 mg KOH / g, preferably less than 1 mg KOH / g, particularly preferably less than 0.3 mg KOH / g, most preferably between 0.1 mg and 0.0 mg KOH / g.

6. Phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to claims 1 to 5, which have a dynamic viscosity of 5 to 5000 mPa s, particularly preferably 5 to 2000 mPa s, most preferably 5 to 500 mPa s at 23 °C.

7. Use of phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to claims 1 to 6 as flame retardants, preferably as flame retardants for synthetic polymers, materials of plant origin or materials of animal origin, and particularly preferably as flame retardants for polyvinyl chloride (PVC).

8. Molding compound containing phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to claims 1 to 6 and polyvinyl chloride (PVC).

9. Molding compound according to claim 8, which contains 5 to 150 parts by weight, preferably 10 to 120 parts by weight, preferably 20 to 100 parts by weight, particularly preferably 30 to 70 parts by weight of the phenylphosphonic acid esters of formulas (I) to (III) according to the invention, based on 100 parts by weight of PVC.

10. Use of molding compounds according to claim 8 or 9 for the manufacture of coatings, films, floor coverings, cables, pipes, hoses, seals, conveyor belts, roofing membranes, adhesive tape films, tarpaulins, awnings or tents.

11. Use of the phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to claims 1 to 6 as a hydraulic fluid.

12. Use of the phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to claims 1 to 6 as a lubricant additive.

13. Use of the phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to claims 1 to 6 as an additive for paints, adhesives, sealants or coatings.

14. Use of the phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to claims 1 to 6 as heat transfer fluids or as additives for heat transfer fluid preparations. P001 01247 A - 16 - 15. Use of the phenylphosphonic acid esters or phenylphosphonic acid ester mixtures according to claims 1 to 6 as solvents or extraction agents.

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