ITEM FOR FOOD CONTACT APPLICATIONS

Abstract

The invention relates to an item selected from the group consisting of containers for packaging, serving, storing and/or transporting fats, oils and fatty foods, tools for the consumption of fats, oils and fatty foods, tools for producing, preparing, shaping and processing fats, oils and fatty foods, as well as parts of machines for producing, preparing, shaping and processing fats, oils and fatty foods, including a moulded body consisting of a particular thermoplastic polycarbonate composition, wherein the moulded body is in direct contact with the fats, oils and fatty foods during the use of the item. The invention also relates to the use of the specific thermoplastic polycarbonate composition for producing the moulded body as a part of the item, the use of the item for transporting, packaging, storing, handling, producing, preparing, processing and shaping fats, oils and fatty foods, and a method for producing a shaped fat or fatty food.

Claims

1-15. (canceled)

16. A thermoplastic molded article for food contact applications comprising: A) aromatic polycarbonate, B) rubber-modified vinyl (co)polymer comprising: B.1) 80% to 95% by weight, based on the rubber-modified vinyl (co)polymer B, of structural units derived from at least one vinyl monomer, and B.2) 5% to 20% by weight, based on the rubber-modified vinyl (co)polymer B, of one or more elastomeric graft substrates having glass transition temperatures <50 C. and containing at least 50% by weight based on B.2 of structural units derived from 1,3-butadiene, wherein the rubber-modified vinyl (co)polymer B contains (i) a disperse phase consisting of (i.1) rubber particles grafted with vinyl (co)polymer composed of structural units of B.1, and (i.2) vinyl (co)polymer likewise composed of structural units of B.1 enclosed in the rubber particles as a separate disperse phase, and (ii) a rubber-free vinyl (co)polymer matrix consisting of structural units of B.1 which is not bonded to the rubber particles and is not enclosed in these rubber particles, wherein the disperse phase of (i) has a median diameter D50 measured by ultracentrifugation of 0.3 to 2.0 m.

17. The article of claim 16, wherein component A is an aromatic polycarbonate based exclusively on bisphenol A.

18. The article of claim 16, wherein component B.1 is a mixture of structural units derived from styrene and acrylonitrile.

19. The article of claim 16, wherein component B.1 further comprises additional structural units derived from butyl acrylate or methyl methacrylate.

20. The article of claim 16, wherein component B.2 is polybutadiene rubber or styrene-butadiene (block) copolymer rubber.

21. The article of claim 16, wherein component B is free from alkali metal, alkaline earth metal, ammonium or phosphonium salts of saturated fatty acids having 8 to 22 carbon atoms, resin acids, alkyl- and alkylarylsulfonic acids and fatty alcohol sulfates.

22. The article of claim 16, wherein the component B contains less than 20 ppm of ions of alkali metals and alkaline earth metals.

23. The article of claim 16, further comprising one polymer additive selected from the group consisting of C8-C22 fatty acid esters of pentaerythritol, C8-C22 fatty acid esters of glycerol, tris(2,4-di-tert-butylphenyl)phosphite, 2,6-di-tert-butyl-4-(octadecanoxycarbonylethyl)phenol, tetrakis(2,4-di-tert-butylphenyl)-4,4-biphenyldiphosphonite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite and triethylene glycol bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate].

24. The article of claim 16, wherein the thermoplastic composition comprises 60-75% by weight of the component A, 24-39% by weight of the component B and 0.1-1% by weight of a polymer additive or a polymeric blend partner.

25. The article of claim 16, wherein the article is a container for packaging, for serving, for storage and/or for transport of fats, oils or fat-containing foodstuffs; a tool for consumption of fats, oils or fat-containing foodstuffs; a tool for production, preparation, shaping and processing of fats, oils or fat-containing foodstuffs; or a part of a machine for the production, preparation, shaping or processing of fats, oils or fat-containing foodstuffs.

26. The article of claim 16, wherein the article is a mold.

27. The article of claim 26, wherein the article is a chocolate mold.

28. A process for producing a molded fat or fat-containing foodstuff, the process comprising the steps of: a) heating the fat or fat-containing foodstuff above its melting point, b) filling the molten fat or fat-containing foodstuff into an article of claim 26, c) cooling the fat or fat-containing foodstuff below its melting point and d) demolding the molding produced from the fat or fat-containing foodstuff in process steps a) to c) from the article.

Description

EXAMPLES

Component A1

[0220] Linear polycarbonate based on bisphenol A having a weight-average molecular weight M.sub.W of 28 000 g/mol (determined by GPC at room temperature in methylene chloride against a BPA-PC standard).

Component A2

[0221] Linear polycarbonate based on bisphenol A having a weight-average molecular weight M.sub.W of 25 000 g/mol (determined by GPC at room temperature in methylene chloride against a BPA-PC standard).

Component A3

[0222] Linear polycarbonate based on bisphenol A having a weight-average molecular weight M.sub.W of 19 000 g/mol (determined by GPC at room temperature in methylene chloride against a BPA-PC standard).

Component B-1

[0223] Acrylonitrile-butadiene-styrene (ABS) polymer produced in a bulk polymerization process which contains a disperse phase composed of polybutadiene-containing rubber particles which are grafted with styrene-acrylonitrile copolymer and contain enclosed styrene-acrylonitrile copolymer as a separate disperse phase and a styrene-acrylonitrile copolymer matrix which is not chemically bonded to the rubber particles and not enclosed in the rubber particles. Component B has an A:B:S ratio of 23:10:67% by weight and a gel content, determined as the acetone-insoluble proportion, of 20% by weight. The acetone-soluble proportion of the styrene-acrylonitrile copolymer in component B is 80% by weight based on the component B and has a weight-average molecular weight M.sub.W (measured by GPC in tetrahydrofuran as the solvent with a polystyrene standard) of 165 kg/mol. The median particle size of the disperse phase D50, measured by ultracentrifugation, is 0.85 m. The melt volume flow rate (MVR) of the component B1, measured according to ISO 1133 (2012 version) at 220 C. with a piston load of 10 kg, is 6.7 ml/10 min.

Component B-2

[0224] Precompound composed of 50% by weight of an ABS-type graft polymer produced in an emulsion polymerization process having an A:B:S ratio of 12:56:32% by weight and 50% by weight of a styrene-acrylonitrile copolymer produced in a bulk polymerization process having a styrene-acrylonitrile ratio of 72:28% by weight and having a weight-average molecular weight Mw of 100 kg/mol measured by GPC in dimethylformamide at 20 C. with a polystyrene standard.

Component C1

[0225] Pentaerythritol tetrastearate

Component C2

[0226] Irganox 1076 (BASF, Ludwigshafen, Germany)

[0227] 2,6-di-tert-butyl-4-(octadecanoxycarbonylethyl)phenol

Production and Testing of the Molding Compounds According to the Invention

[0228] The mixing of the components was carried out under good manufacturing practice (GMP) conditions in a Werner & Pfleiderer ZSK-70 twin-screw extruder at a melt temperature of 260 C. and with application of a reduced pressure of 100 mbar (absolute).

[0229] The molded bodies were produced at melt temperatures of 260 C. or 290 C. and in both cases at a mold temperature of 80 C. in an Arburg 270 E injection molding machine.

[0230] The melt volume flow rate (MVR) was determined according to ISO 1133 (2012 version) at 260 C. with a piston load of 5 kg after a dwell time of 5 minutes.

[0231] IZOD notched impact strength was determined at 23 C. according to ISO 180-1A (1982 version) on each of ten test specimens measuring 80 mm10 mm4 mm and is reported in table 1 as the average of ten individual measurements. The test specimens were produced at a melt temperature of 260 C.

[0232] Vicat B/120 as a measure of heat resistance was determined according to ISO 306 (2013 version) on test specimens measuring 80 mm10 mm4 mm with a piston load of 50 N and a heating rate of 120 C./h. The test specimens were produced at a melt temperature of 260 C.

[0233] Melt viscosity as a measure of melt flowability was determined according to ISO 11443 (2014 version) at temperatures of 260 C. or 300 C. and in both cases at a shear rate of 1000 s.sup.1.

[0234] The stress cracking resistance (ESC) in rapeseed oil was used as a measure of the stability of the molded bodies in contact with fats, oils and fat-containing foodstuffs. The time until stress cracking-induced fracture failure at room temperature of a test specimen injection-molded under the above-described conditions and having dimensions of 80 mm40 mm4 mm was determined by subjecting the test specimen to 2.4% outer fiber strain by means of a clamping template and completely immersing it into the rapeseed oil. This measurement was carried out according to DIN EN ISO 22088 (2006 version).

[0235] The relative percentage change in melt flow rate MVR (delta MVR) was used as a measure of the hydrolysis resistance of the molded bodies.

delta MVR=100(MVR.sub.after storageMVR.sub.before storage)/MVR.sub.before storage,

[0236] wherein the MVR was measured according to ISO 1133 (2012 version) at 260 C. with a piston load of 5 kg before and after seven days of storage at 95 C. and 100% relative humidity. In the present case the storage was performed on pellets.

[0237] Surface gloss was measured in reflection at viewing angles of 20 and 60 with a Haze-Gloss instrument from BYK-Gardner GmbH (Geretsried, Germany) according to DIN 67530 (1982 version) on test specimens having dimensions of 60 mm40 mm4 mm. An injection mold polished to a high shine was used to produce the test specimens. The test specimens were produced at a melt temperature of 260 C.

[0238] The tensile elastic modulus as a measure for stiffness was determined at room temperature according to ISO 527 (1996 version). The test specimens were produced at a melt temperature of 260 C.

[0239] According to COMMISSION REGULATION (EU) No 10/2011 of Jan. 14, 2011 concerning materials and objects made of plastic which are intended to come into contact with foodstuffs, total migration is to be understood as meaning the amount of non-volatile substances emitted from a material or article into food simulants. Total migration was determined according to DIN EN 1186-14 (2002 version) on test bars having dimensions of 80 mm10 mm4 mm in respective two-hour complete contact with a) isooctane and b) in ethanol (95% by volume) as food simulants at 70 C. To this end such a test bar having a total surface area of 0.16 dm.sup.2 was in each case completely immersed in 37 ml of the food simulant. The test specimens were produced at a melt temperature of 260 C.

[0240] To simulate the influence of polycarbonate compositions on the constitution of different foodstuffs with which molded bodies produced from these polycarbonates compositions are in direct contact upon use of articles containing such molded bodies, 100 g of pellets of the compositions 1 and V5 were stored for 2 days at room temperature (RT) in 100 g in each case of different food simulant media. After storage the haze value (clouding) according to ISO 14792 (containing 1999 version) of the decanted media employed was analyzed using a Perkin Elmer Lambda 950 instrument. A higher haze (clouding) value in the same medium points to increased migration from the pellets into the medium and thus indicates increased influencing of the foodstuff constitution which is not desired in the food contact application. The employed media simulate different types of foodstuffs.

[0241] A similar test was used to simulate migration characteristics under conditions such as are encountered in the production of a molded fat or fat-containing foodstuffsuch as for instance a chocolate moldingusing a mold.

[0242] To this end 30 g of pellets of samples 1, V2 and V5 were in each case stored for 2 hours with stirring in 30 g of isooctane heated to 70 C. in a glass flask, the isooctane was then decanted and the haze (clouding) value of the decanted food simulant according to ISO 14792 (1999 version) was analyzed using a Perkin Elmer Lambda 950 instrument.

TABLE-US-00001 TABLE 1 Compositions and properties thereof 1 V2 V3 V4 Components [parts by weight] A1 70 100 A2 100 A3 100 B-1 30 C1 0.3 C2 0.1 Properties ESC (time until fracture) [h] melt >24 >24 <0.01 temperature in the injection mold: 260 C. ESC (time until fracture) [h] melt 2.5 0.5 temperature in the injection mold: 290 C. Notched impact strength [kJ/m.sup.2] 55 68 Vicat B/120 [ C.] 133 146 MVR [ml/10 min] 15 14 Melt viscosity (260 C.) [Pa s] 243 735 546 260 Melt viscosity (300 C.) [Pa s] 241 205 Tensile elastic modulus [MPa] 2316 2324 Hydrolysis resistance (delta MVR) [%] 8 Gloss (20) 43 201 Gloss (60) 84 177 Total migration in isooctane <10 mg/dm.sup.2 not determined Total migration in ethanol (95%) <10 mg/dm.sup.2 not determined

[0243] The data in table 1 show that the inventive composition 1 solves the technical problem. Said composition features an improved melt flowability compared to pure polycarbonate having a molecular weight corresponding to that of component A in the inventive composition (V2). The produced articles exhibit good resistance to oil and a low gloss coupled with mechanical properties similar to an article made of the pure polycarbonate. Increasing the temperature during processing to achieve a melt flowability in injection molding similar to that in the composition according to the invention results in a significantly poorer resistance to stress cracking in oil of the thus produced articles. Compared to pure polycarbonate having a lower molecular weight which has a similar melt flowability to the inventive composition (V4), the inventive composition exhibits a markedly improved resistance to stress cracking in oil of the articles produced under comparable conditions by injection molding.

TABLE-US-00002 TABLE 2 Compositions and properties thereof 1 V2 V5 Components [parts by weight] A1 70 100 70 B-1 30 B-2 30 C1 0.3 0.3 C2 0.1 0.1 Properties Haze [%] 2.68 0.13 Mixture of 90% by volume of water and 10% by volume of ethanol, 2 days at RT Haze [%] 5.53 0.21 Mixture of 50% by volume of water and 50% by volume of ethanol, 2 days at RT Haze [%] 0.44 0.27 Mixture of 97% by weight of water and 3% by weight of acetic acid, 2 days at RT Haze [%] 0.19 0.31 Isooctane, 2 days at RT Haze [%] 0.34 0.34 0.39 Isooctane, 2 hours at 70 C.

[0244] The data in table 2 show that the compositions 1 and V5 influence the constitution of the different food simulant media in markedly different ways although both compositions are comparable in terms of the proportions of polycarbonate, ABS and additives. The haze values for the aqueous food simulants are markedly lower after contact with the composition V5 than after contact with the composition 1, i.e. the constitution of these aqueous simulants is influenced by the composition V5 to a markedly lesser extent than by the inventive composition 1. By contrast, in isooctane which serves as a simulant for fat-containing foodstuffs clouding is markedly lower after contact with the inventive composition 1 than after contact with the composition V5. It is apparent from the foregoing that composition 1 is more suitable for use in contact with fat-containing foodstuffs while the composition V5 is more advantageous for contact with water-containing foodstuffs such as coffee for instance. Also at higher temperatures and shorter contact times between the food simulant and the pellets with isooctane as the food simulant for fats and fat-containing foodstuffs a lower clouding (haze) is observed with the inventive composition 1 than for V5. This also suggests better suitability for use in the production of molded fats and fat-containing foodstuffs, such as chocolate moldings. While composition V2 exhibits equally good characteristics in this regard as composition 1 it has the disadvantage, shown in table 1, of a markedly higher melt viscosity and an undesirably high gloss for use in the production of chocolate molds.