CH663141A5 - OVEN KITCHEN UTENSILS MADE OF PLASTIC CONTAINING TALKUM. - Google Patents

Description

The invention is explained in more detail in the following examples, in which all parts and percentages are based on weight, unless stated otherwise. These non-limiting examples relate to certain embodiments and are intended to serve as a guide for those skilled in the art in practicing the invention.

example 1

This example illustrates the synthesis of a copolyester useful for the present invention.

The following amounts and ingredients were combined as indicated.

O

II

c

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Substance name

component

Amount of grams

Mol

A

p-hydroxybenzoic acid

138

1

B

Phenylacetate

170

1.25

C.

Therminol 77

500

-

D

Diphenyl terephthalate

318

1

E

Hydrogen chloride

-

F

Hydroquinone

111

1.01

G

Therminol 77

500

-

The compounds A to D are introduced into a four-necked round-bottom flask equipped with a stirrer, a combined nitrogen and HCl inlet and connected to a cooler. Nitrogen is slowly introduced through the piston inlet. The flask and its contents are heated to 180 ° C, after which HCl is bubbled through the reaction mixture. The outlet head temperature is maintained at 110 to 120 ° C by external heating during the exchange reaction between p-hydroxybenzoic acid and phenylacetate ester.

The flask and its contents are stirred at 180 ° C for 6 hours after which the HCl feed is stopped. The outlet head temperature is raised to 180 to 190 ° C and the mixture is then stirred at 220 ° C for 3.5 hours. At this point there are 159 g of distillate in the template. Compound F is then added and the temperature is gradually increased from 220 ° C to 320 ° C over a period of 10 h (10 ° C / h). Thereafter, stirring is continued at 320 ° C for 16 hours and then at 340 ° C for 3 hours to obtain a slurry. The total amount of distillate consisting of phenol, acetic acid and phenylacetate is 384 g. Compound G is added and the reaction mixture is allowed to cool to 70 ° C. Acetone (750 ml) is then added and the slurry filtered. The solids are extracted with acetone in a Soxhlet extractor to remove compounds C and G. The solid is dried in vacuo at 110 ° C. overnight, whereupon the resulting copolyester (320 g, 89.2% of theory) is obtained as a granular powder.

Example 2

518 parts of isophthalic acid, 1557 parts of terephthalic acid, 5175 parts of p-hydroxybenzoic acid, 6885 parts of acetic anhydride and 2325 parts of p, p'-bisphenol are mixed together and refluxed at a temperature of about 180 ° C. for 17 hours, after which the reflux condenser is passed through a The still is replaced and the temperature is raised to 345 ° C over a period of 1 1/4 hours. The reaction mixture is stirred during the heating period, particularly intensively during the period in which the temperature is increased to 345 ° C. The yield of polymer is 8020 parts, and 8010 parts of distillate are obtained. The contents are discharged from the reaction vessel, cooled and ground to a particle size in the range of 0.84 to 0.080 mm (20 to 60 mesh, U.S. Standard Sieve Series). The resin obtained has a molecular weight in the range from 5,000 to 20,000, the average molecular weight being approximately in the middle of this range. The product was estimated to have a crystallinity of approximately 50%.

The resin particles were kept under vacuum at an elevated temperature and an absolute pressure of about 100 mm of mercury for 8 hours and obtained as a granular powder.

663 141

Example 3

The following amounts of the following ingredients are combined as indicated.

Substance component Quantity designation Gram Mol

A terephthalic acid 291 1.75

B p-hydroxybenzoic acid 483 3.50

C p, p'-Biphenol 325 1.75

D Acetic anhydride 755 7.40

The compounds A to D are heated to 145 C under reflux overnight. The reflux condenser is removed and replaced by a still. The mixture is heated to 300 ° C. with stirring at a rate of 20 ° C./hour and the contents are removed from the reaction vessel. At this point, about 92 to 94% of the theoretical acetic acid is obtained. The prepolymer is ground and worked up further as indicated in Example 2 at a temperature of about 250 to 375 ° C.

Example 4

substance

component

amount

designation

Grams

Mol

A

p-hydroxybenzoic acid

276.0

(2.00)

B

Terephthaloyl chloride

203

1.0

C.

Trimesic acid

8.4

0.040

D

Therminol 66

1274

E

p, p'-biphenol

186

1.0

F

Acetic anhydride

224.6

2.2

The compounds A to D are heated to 130 ° C. and kept at this temperature for 1 hour. The reaction is exothermic and care must be taken to keep the temperature at 130 ° C. The contents are then heated to 155 ° C for 1 hour and then to 180 ° C for 4 hours. The mixture is then cooled to 150 ° C and compound E is added, further reducing the temperature to 140 JC. The connection F is then added. The mixture is then refluxed to 155C for 1 hour after which the reflux condenser is replaced with a distillation column. Acetic acid forms during the distillation and the contents of the reaction vessel are then kept at 330 ° C. for 3 hours. The suspended polymer is cooled to 250 C and the mixture is filtered through a filter. The solid is worked up with trichlorethylene to remove the heat transfer liquid. The dried powder is then worked up in vacuo as described in Example 2.

Examples 5, 6 and 7 The procedure described in Example 3 is repeated using the following amounts and compounds.

Substance constituent Amount in moles Description Ex. 5 Ex. 6 Ex. 7

A terephthalic acid 1 1 1

B p-hydroxybenzoic acid 3 4 5

C p, p'-biphenol 1 1 1

D acetic anhydride

Example 8

268 parts biphenol, 396 parts p-hydroxybenzoic acid, 693.40 parts acetic anhydride and 238 parts terephthalic

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663 141

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Acid are mixed together and heated to 315 ° C. over a period of 5 hours at a temperature increase from 30 ° C. per hour. The reaction mixture is stirred during the heating period. When the temperature of 315 ° C is reached, the polymer content is removed from the reaction vessel and ground to a particle size in the range of 0.84 to 0.074 mm (20 to 200 mesh). The resin particles are heated in an oven to 354 ° C. for 16 hours and obtained as a granular powder.

Example 9

A molding composition was made from the polymer according to Example 8 by extrusion molding a mixture of 257.5 parts of the polymer according to Example 8, 30 parts of rutile titanium dioxide and 212.5 parts of a high-purity talc with the flaky structure of natural talc, a loss on ignition of 2% by weight .-%, an iron content, determined as Fe203, of 0.5% and a particle size distribution in which over 95% of the particles are smaller than 40 μm.

The resulting mixture was injection molded into trays with a uniform, pleasing appearance that showed no cracking or blistering at minimum temperatures of about 260 ° C.

Some of the molded articles were subjected to a durability test in which a barbecue sauce was applied to the bottom of the molded container. The container was then heated in an oven preheated to 146 ° C for 1 hour. After this time, the sauce was thick, dark, and crusted. After cooling, the container was washed with soap and water using a "Scrunge" pad. The container was examined for stains and the color difference between the stain and the non-stained area was determined. The difference observed was very small.

Some other samples were subjected to a drop test in which 5 samples were dropped with their top outer peripheral surface from increasing heights to determine their ability to withstand the impact without noticeable damage. The average for these samples was 101 cm.

All results of these tests show the suitability of the molded articles for use as cookware for food.

Example 10

A molding composition was prepared from the polymer made in Example 8 by extruding a mixture of 271 parts of polymer and 10 parts of the talc used in Example 9.

The resulting mixture was injection molded at a screw speed of 100 rpm, an injection pressure of 140 bar and a temperature of 355 ° C. in zone 1, 360 ° C. in zone 2 and 345 ° C. in zones 3 and 4.

The molded objects obtained had a pleasing appearance.

Examples 11 to 18

In these examples, 257.5 parts of the resin products according to Examples 1 to 8 were mixed with 202.5 parts of the talc used in Example 9 and 40 parts of rutile titanium dioxide in a twin-screw extruder. The resulting reinforced resin compositions were injection molded. The molded articles obtained had a pleasing appearance and were resistant to cracking and blistering at elevated temperatures.

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Claims (30)

663 141 2nd PATENT CLAIMS 1. Multi-use oven cookware made of a molded aromatic polyester mass, which is not subject to blistering during shaping or use in the oven, characterized in that the polyester mass 35 to 65 wt .-% completely aromatic polyester and 1 to 60 wt .-% % of a talc with a minimum content of substances which can be decomposed at elevated temperatures, the talc being characterized by a combustion weight loss of at most 6% by weight at 950 ° C. and 2% by weight at 800 ° C. and an iron content, calculated as iron oxide , of at most 1% by weight. 2. Oven cookware according to claim 1, characterized in that the aromatic polyester is an oxybenzoylpolyester. 10th - 15th 3. Oven cookware according to claim 1 or 2, characterized in that it contains 2 to 20 wt .-% rutile titanium dioxide. 4. Oven cookware according to one of claims 1 to 3, characterized in that the content of talc in the mass is 35 to 55 wt .-%. 5. Oven cookware according to claim 3 or 4, characterized in that the content of rutile titanium dioxide is 5 to 15 wt .-%. 6. Oven cookware according to claim 4 or 5, characterized in that the talc is selected from the group of high-purity talc, highly refined talc, calcined talc and acid-treated talc. 7. Oven cookware according to one of claims 2 to 6, characterized in that the oxybenzoyl polyester repeating units from the group comprising one or more of the following formulas: - OC co -r II CO III IV oc co 0 contains ti, where x is O, S, -C-, NH or S02 is and n is 0 or 1 and the total sum of the integers p + q + r + s + 1 + u in the available units is 3 to 800. 8. Oven cookware according to claim 7, characterized in that the ratio of q / r, q / u, t / r, t / u, q + t / r, q + t / r + uundt / r + u 10 is up to 11/10. 9. Oven cookware according to claim 8, characterized in that the ratio is 10/10. 10. Oven cookware according to one of claims 2 to 6, characterized in that the oxybenzoyl polyester VI so recurring units of the formulas: u 55 (VII) (VIII) (IX) 3rd 663 141 where x = - O— or - SO2—; m '= 0 or 1; n '= 0 or 1; q ': r' = 10:15 to 15:10; p ': q' = 1: 100 to 100: 1; p '+ q' + r '= 3 to 600; the carbonyl groups of the unit of the formula VII or VIII are bonded to the oxy groups of the unit of the formula VII or IX; and the oxy groups of the formula VII or IX unit are attached to the carbonyl groups of the formula VII or VIII unit. 11. Oven cookware according to one of claims 2 to 6, characterized in that the oxybenzoyl polyester repeating units of the formula: having. 12. Oven cookware according to claim 7, characterized in that n = O. 13. Oven cookware according to claim 10, characterized in that p '+ q' + r '= 20 to 200. 14. Oven cookware according to one of claims 1 to 13, characterized in that the talc is a highly refined talc. 15. Oven cookware according to one of claims 1 to 13, characterized in that the talc is a calcined talc. 16. Oven cookware according to one of claims 1 to 13, characterized in that the talc is an acid-treated talc. 17. Oven cookware according to one of claims 1 to 13, characterized in that the talc is a high-purity talc. 18. Use of the oven cookware according to claim 1 for heating food to the serving temperature. 19. Use according to claim 18 of the oven cookware according to one of claims 2 to 17. 20. Use according to claim 18 or 19, characterized in that the heat source is thermal. 21. Use according to claim 18 or 19, characterized in that the heat source is a microwave heat source. 22. A polyester molding composition for the manufacture of an oven cookware according to claim 1, which does not cause blistering during the molding or use in the oven 35 40 Is characterized, characterized in that it contains 35 to 65 wt .-% of a fully aromatic polyester and 1 to 60 wt .-% of a talc with a minimum content of decomposable at elevated temperatures, the talc by a combustion weight loss of at most 6 wt. -% at 950 ° C and 2 wt .-% at 800 C and has an iron content, calculated as iron oxide, of at most 1 wt .-%. 23. Molding composition according to claim 22, characterized in that the aromatic polyester is an oxybenzoyl polyester. 24. Molding composition according to claim 22 or 23, characterized in that it contains 2 to 20% by weight of rutile titanium dioxide. 25. Molding composition according to one of claims 22 to 24, characterized in that talc is present in the mass in an amount of 35 to 55 wt .-%. 26. Molding composition according to one of claims 22 to 25, characterized in that the amount of rutile titanium dioxide is 5 to 15 wt .-%. 27. Molding composition according to claim 25 or 26, characterized in that the talc is selected from the group of high-purity talc, highly refined talc, calcined talc and acid-treated talc. 28. Molding composition according to one of claims 22 to 27, characterized in that the polyester contains repeating units of one or more of the following formulas: U 663 141 0 II where x for O, S, - C -, NH or SO2 and n is 0 or 1 and the total sum of the integers p + q + r + s + t + u in the available units is 3 to 800. 29. Molding composition according to one of claims 23 to 27, characterized in that the oxybenzoyl polyester repeating units of the formulas: (X) m VII Vili IX contains, where x = - O— or - S02; m '= 0 or 1; n '= 0 or 1; q ': r' = 10:15 to 15:10; p ': q' = 1: 100 to 100: 1; p '+ q' + r '= 3 to 600; the carbonyl groups of the units of the formula VII or VIII are bonded to the oxy groups of the unit of the formula VII or IX; and the oxy groups of the unit of the formula VII or IX to the car r \ -i- bonyl groups of the unit of formula VII or VIII are bound. 30. Molding composition according to one of claims 23 to 27, characterized in that the oxybenzoyl polyester repeating units of the formula: -CK> 4 having. As is known, certain plastics have found application in the field of oven cookware. For example, polymethylpentene was used for the injection molding of bowls and the like. The like. Used that can be used for the preparation of food. Polysulfone has also been used for food handling. However, no satisfactory material has yet been found that is useful within the wide range of conditions and requirements for cookware that can be used in both thermal and microwave ovens. In addition to the obvious necessity that the material has to withstand the temperatures of the heat sources used for cooking, a unique combination of other properties is also required for the material if cookware made from it is to be suitable for the preparation of food. The material must have good electrical properties. Severe thermal shocks must be tolerated so that the cookware made from it can be brought from extremely cold to high temperatures in a relatively short time. The material must have good hardness and impact resistance as well as high tensile and bending strength. It must also be resistant to boiling water and food acids and the adverse effects of detergent treatment. 40 With regard to the properties associated with the food, the material must make the cookware made from it insensitive to stains caused by a wide variety of foods. It has to provide a surface with nothing attached to it and from which the food can easily detach. It must not develop or release volatile substances and it must not contain any extractable components. In addition to all of the foregoing requirements, the articles made from the material must have a pleasing and generally uniform appearance. The aim of the invention is therefore to provide an oven cookware that meets the strict requirements of the cookware market. The dishes are obtained by making the cookware from a plastic based on 55 fully aromatic polyesters, in particular from oxy-benzoyl polyesters. The fully aromatic polyesters used according to the invention consist of combinations of repeating units with one or more of the following formulas: 5 663 141 O ti where xO, S, —C—, Represents NH or SO2 and n is 0 or 1, and the total sum of the integers p + q + r + s + 1 + u in the available units is from about 3 to about 800. Combinations of the above units result from the combination of the carbonyl group of formulas I, II, IV and V with the oxy group of formulas I, III, IV and VI. In the most comprehensive combination, all units of the above formulas can be present in a single copolymer. The simplest embodiment would be homopolymers of units I or IV. Other combinations are e.g. B. Mixtures of units II and III, II and IV, III and V, V and VI and I and IV. The functional groups are preferably in the para (- 1,4) position. They can also be in the ortho (1, 2) position to one another. In the naphthalene unit, the most desirable positions of the functional groups are 1,4; 1.5 and 2.6. Such groups can also be in the or-tho position to one another. The symbols p, q, r, s, t, and u mean integers and indicate the number of units present in the polymer. The total (p + q + r + s + t + u) can vary from 30 to 800, and the possible ratio of q / r, q / u, t / r, t / u, q + t / r, q + t / r + u and t / r + u can be between about 10/11 and 10/10, with the 10/10 ratio being the most preferred. Examples of materials from which the units of the formula I can be obtained are p-hydroxybenzoic acid and its esters, such as phenyl p-hydroxybenzoate, p-20 acetoxybenzoic acid and isobutyl p-acetoxybenzoate. The unit of formula II is e.g. B. derived from terephthalic acid, isophthalic acid, diphenyl terephthalate, diethyl isophthalate, methyl ethyl terephthalate and the isobutyl half ester of terephthalic acid. The unit of formula III results, for. B. from 25 p, p'-bisphenol; 4,4'-dihydroxybenzophenone; Resorcinol and hydroquinone. A check shows which of these substances the units of the formulas I — VI can deliver. Examples of monomers of formula IV are 2-hydroxy-6-naphthoic acid, 6-hydroxy-1-naphthoic acid, 5-30 acetoxy-1-naphthoic acid and phenyl-5-hydroxy-1-naphthoate. Monomers of formula V are e.g. 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid and 2,6-naphthalenedicarboxylic acid. The diphenyl esters or dicarbonyl chlorides of these acids can also be used. Examples of monomers of the formula VI are 1,4-di-hydroxynaphthalene, 2,6-diacetoxynaphthalene and 1,5-dihydroxy-naphthalene. In the practice of the invention, plastics based on oxybenzoyl polyesters are particularly preferred. 40 The oxybenzoyl polyesters usable according to the invention are generally those with repeating units of the formulas VIII and IX (VIII) O II c Jl ^ O II c (IX) in these formulas, x stands for - O or - SO2; m for 0 or 1; n for 0 or 1; q; r = 10:15 to 15:10; p: q = 1: 100 to 100: 1; p + q + r = 3 to 600, preferably 20 to 200. The carbonyl groups of the units of the formula I or III are bonded to the oxy groups of the units of the formula I or IV; the oxy groups of the units of the formula I or IV are bonded to the carbonyl groups of the unit of the formula I or III. 60 65 Another group of aromatic polyesters which are useful for the purposes of the present invention are the aromatic polyesters which contain the 2,6-dicarboxynaphthalene and / or the p-oxybenzoyl units and symmetrical di-oxyaryl units and variations thereof as repeating units. Such polyesters are disclosed in U.S. Patents 4,067,852; 4,083,829; 4,130,545; 4,161,470; 4,184,996; 4,219,461; 4,224,433; 4,238,598; 4,238,599; 4,256,624; 4,265,802; 4,279,803; 4,318,841 and 4,318,842. 663 141 6 The preferred copolyesters have the repeating units of the formula X: o II c c - o The synthesis of these polyesters is described in detail in US Pat. No. 3,637,595 entitled "P-Oxybenzoyl Copolyesters", which is incorporated herein by reference. The polyesters useful in the present invention can also be chemically modified in various ways, e.g. by incorporating monofunctional reactants such as benzoic acid or tri- or higher functional reactants such as trimesic acid in the polyester. The benzene rings in these polyesters are preferably unsubstituted, but can also be substituted by non-interfering substituents. The oxybenzoyl polyesters which can be used in the present invention can be used together with various fillers, the character and amounts of which do not significantly affect the desired properties. Examples of suitable fillers are glass fiber, ground glass, polytetrafluoroethylene, pigments and combinations thereof. Although the oven cookware, when made from compositions containing the oxybenzoyl polyesters and the various fillers listed above, meets most of the general requirements listed above, it lacks the uniform, pleasing appearance required of a commercial product. It was also found that many of the fillers lead to excessive blistering in the dishes at elevated temperatures. According to the invention, it has been found that a uniform and pleasing appearance can be imparted to the oven cookware and the undesirable blistering can be suppressed or reduced to a minimum if the oxy-benzoyl compositions from which the dishes are formed are mixed with talc, which is a contains a minimal amount of materials which can be decomposed at elevated temperatures, for example up to about 800 ° C., such as magnesium carbonate. Such types of talc are those of high purity, which have been selectively combined from different ores, or which have been calcined or subjected to acid treatment. The types of talc which can be used for the purposes according to the invention are characterized by a low loss on ignition, a low iron content, determined as iron oxide, and a particle size within a narrow range. The loss on ignition of suitable types of talc is not more than about 6% or less at 950 ° C and 2% or less at 800 ° C. The iron content determined as iron oxide (Fe203) is not more than about 1%, preferred types of talc have an iron content of not more than about 0.6% and less. Experiments and experiments have proven quite conclusively that it is essential to use such talcum species in order to achieve the goals set according to the invention. The use of other talc forms does not lead to satisfactory properties in the finished molded product. However, such other talc forms can be used in conjunction with the types of talc specified above in amounts from about 0.05 to about 20% of the required talc forms. _ o ol (XI The types of talc containing the least amount of decomposable material are present in amounts from about 1 to about 60% based on the total weight of the composition, preferably in a range from about 35 to about 55%. Rutile titanium dioxide can also be used with the talc material, including mixtures of highly refined talc and other talc products. The rutile titanium dioxide is present in an amount from about 2 to about 20% based on the total weight of the composition. The preferred range is about 5 to about 15%. In the molding compositions used in the present invention, the resin is usually present in an amount of about 35 to about 65%, the total amount of inert materials is about 65 to about 35%. The inert materials are present in a proportion of about 40 to about 55% of the molding compositions for best results. The inert components are present in an amount of up to about 55% highly refined talc and about 0 to 10% titanium dioxide. Although all of the resins described above are suitable for the purposes of the invention, a resin is preferably used in which the dibasic acid, the oxyaromatic acid and the aromatic diol are present in molar ratios of about 1: 2: 1. Other molar ratios can be used and resins have been used in which the molar proportions of, for example, terephthalic acid, p-hydroxybenzoic acid and biphenol are 1: 3: 1.1: 5: 1.1: 7: 1 and 1: 3.5 : 1 were. Physical mixtures of resins in which the various proportions of the reactants have been used can also be used. The compositions according to the invention can be produced by extrusion in a manner known per se. For example, a twin screw extruder can be used, with the polymer, the selected talc and the titanium dioxide being introduced through the feed opening and the glass fiber rovin through both the vent opening and the feed opening. The compositions thus produced can be processed in a conventional manner by injection molding.