NL8302500A - PLASTIC MADE AND TALK CONTAINING FIREPROOF KITCHEN EQUIPMENT. - Google Patents

Description

* * N / 31.502-Kp / Pf / cs - 1 -

Refractory kitchenware made of plastic and talc;

It is known that certain plastic materials have found application in the field of refractory kitchenware. Polymethylpentene has been used, for example, for injection molded trays which can be used in the preparation of foodstuffs. Polysulfone has also been used in food processing. However, no satisfactory material has been found to date which is useful over the wide range of conditions and requirements encountered in providing frozen food containers or trays that can be used in thermal or microwave ovens.

In addition to the obvious need for a material that can withstand the temperatures prevailing in the heat source for cooking, such a material must have a unique combination of a number of other properties before baking trays made from this material , can be used successfully in the preparation of food. The material must have good electrical properties. It must be able to withstand severe thermal shocks, since refractory kitchenware made therefrom must be able to transition from extreme cold conditions to high temperature conditions in a relatively short time. The material must have good hardness and impact strength and have high tensile and flexural strength. It must also be resistant to boiling water, food acids and fats and the adverse effects of cleaning agent immersion.

In terms of food properties, the material must provide the refractory kitchenware manufactured therefrom to resist staining from a wide variety of foods. It should give a surface that has good non-stick properties and that the food contained in it comes off easily. It must not emit volatile matter and it must not contain extractables. And, apart from the need to meet all of the aforementioned requirements, articles made therefrom must have a pleasing and generally uniform appearance in order to be sold.

Refractory kitchenware / meeting the above stringent requirements is obtained by manufacturing the refractory articles from a plastic material based on fully aromatic polyesters, especially on oxy-benzoyl polyesters.

The fully aromatic polyesters used in accordance with the present invention consist of combinations of 10 repeating units of one or more of the units with

formulas 1-6 of the formula sheet, wherein x = 0, S, - u -, NH

C

or SC> 2 and n = 0 or 1 and the sum of the integers p + q + r + s + t + uin the units present is between 3 and 800.

Combinations of the above units include 15 bonds of the carbonyl group of formulas 1, 2, 4 and 5 with the oxy group of formulas 1, 3, 4 and 6. In the most general combination, all units of the above formulas may be present in a only copolymer. The simplest embodiment is formed by the homopolymers of the 20 units 1 or 4. Other combinations include mixture of units 2 and 3, 2 and 6, 3 and 5, 5 and 6, and 1 and 4.

The functional groups are preferably placed in the para (1,4) positions. They can also be placed in ortho (1,2) position relative to each other. Regarding the naphthalene unit, the most desirable positions of the functional groups are 1.4; 1.5 and 2.6. These groups can also be in the ortho position relative to each other.

The symbols p, q, r, s, t and u are integers and indicate the number of units present in the polymer.

30 The sum (p + q + r + s + t + u) can range from 3 to 800, and if present, the ratios of q / r, q / u, t / r, t / u, q + t / r + u and t / r + u vary from approx. 10/11 to approx.

11/10, while the most favorable ratio is 10/10.

Materials from which the units of formula I can be obtained are, for example, p-hydroxybenzoic acid and esters such as phenyl-p-hydroxybenzoate, p-acetoxybenzoic acid and isobutyl-p-acetoxybenzoate. The units of formula II can be derived from, for example, terephthalic acid, isophthalic acid, diphenyl terephthalab diethyl isophthalate, methyl ethyl terephthalate and

J

8302500 • »3 -% isobutyl hemiester of terephthalic acid. Compounds which lead to the unit of the formula III are, for example, ρ, ρ'-bi-phenol, 4,4'-dihydroxybenzophenone, 'resorcinol and hydroquinone.

Examples of monomers associated with formula 4 are 2-hydroxy-6-naphthoic acid, 6-hydroxy-1-naphthoic acid, 5-acetoxy-1-naphthoic acid and phenyl-5-hydroxy-1-naphthoate. Monomers associated with formula 5 include 1,4-naphthalene dicarboxylic acid, 1,5-naphthalenedicarboxylic acid and 2,6-naphthalenedicarboxylic acid. The diphenyl esters or dicarbonyl chlorides of these 10 acids can also be used. Examples of monomers associated with formula 6 are 1,4-dihydroxynaphthalene, 2,6-diacefoxynaphthalene and 1,5-dihydroxynaphthalene.

Particularly preferred in the practice of the present invention are plastic materials based on oxybenzoyl polyesters.

A preferred group of oxybenzoyl polyesters is formed by copolyesters of repeating units of formulas 7, 8 and 9 of the formula sheet, wherein X = -O or -SO 2, m = 0 or 1, n = 0 or 1, q: r * 10:15 to 15:10; p: q = 1: 100 to 20 100: 1? p + q + r = 3-600, preferably 20-200. The carbonyl groups of the unit of formula 7 or 8 are bonded to the oxy groups of a unit of formula 7 or 9? the oxy groups of the unit of formula 7 or 9 are bonded to the carbonyl group of the unit of formula 7 or 8.

Another group of aromatic polyesters that can be used are the aromatic polyesters containing recurring units of the 2,6-dicarboxynaphthalene unit and / or the p-oxybenzoyl unit and symmetrical dioxy-aryl unit, and variations thereof. Such polyesters are described in U.S. Pat. Nos.

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.

Preferred copolyesters are those having 35 repeating units of formula 10 of the formula sheet.

The synthesis of such polyesters is described in detail in U.S. Pat. 3,637,595, with the short designation "p-Oxybenzoyl copolyesters".

8302500

4 V.

- 4 -

The copolyesters to be used according to the present invention can also be chemically modified in various ways, such as by incorporation in the polyester of mono-functional reagents, such as benzoic acid, or tri- or higher functional reagents, such as trimesic acid. The benzene rings in these polyesters are preferably unsubstituted, but may optionally be substituted with non-interfering substituents.

The oxy-benzoyl polyesters useful in the present invention can be used with various fillers of types and amounts that either promote or at a minimum do not significantly affect the desired properties. Examples of suitable fillers include glass fibers, ground glass powder, polytetra-fluoroethylene, pigments and fillers, and combinations thereof.

While refractory kitchenware made from compositions containing the said oxybenzoyl polyesters and the various fillers already satisfies most requirements, they do not give the uniform, pleasant appearance necessary for a salable product. In addition, it has been found that many of the fillers cause excessive bubbling in the refractories at high temperatures.

It has now been found that a pleasing and uniform appearance can be imparted to the refractory articles and suppress or be minimized by unwanted bulge formation by incorporation in the oxybenzoyl compositions from which these articles are made of talc containing a minimum amount of materials. which decompose at elevated temperatures, for example up to 800 ° C, such as magnesium carbonate. Such talc is very pure and is obtained by selective combination from different sources or after calcination or under acid treatment.

These talcs, which are used in accordance with the present invention, are recognized by low ignition weight loss, low iron oxide content as iron oxide, and precisely controlled particle size.

a

8302500 - 5 - * *. The ignition weight loss of suitable talc is no more than about 6% or less at 950 ° C and is 2% or less at 800 ° C. The iron content determined as iron oxide (Fe2O.j) will not exceed about 1% and is preferably no more than about 0.6% and may even be lower.

Experiments and experiments conducted have clearly shown that it is essential that such talc is used in order to achieve the objects of the present invention. The use of other talc forms does not provide satisfactory properties in the finished molded product. However, such other forms of talc can be used in conjunction with the indicated talc in amounts of about 0.05-20% of the required talc forms.

The talc containing the minimum amount of decomposable material will be present in amounts of about 1-60% based on the total weight of the composition, preferably in an amount of about 35-55%.

Rutile titanium dioxide can also be used in conjunction with the talc material, including mixtures of highly purified talc and other talc. The rutile titanium dioxide will be present in an amount of about 2-20% based on the weight of the total composition. The preferred range is 5-15% by weight.

In the compositions of the present invention, the resin will generally be present in an amount of from about 35-85% and the total inert materials will make up about 65-15%. For optimal results, the inert substances form about 40-55% of the compositions. The inert materials consist of up to 55% of highly purified talc and about 0-10% of titanium dioxide.

While all of the aforementioned resins are suitable for use in the present invention, it is preferred to use the resin in which the dibasic acid, hydroxy-substituted aromatic acid and aromatic diol are present in the molar ratios of about 1: 2 : 1. Other molar ratios can be used and resins have been used, wherein the molar ratios between, for example, 8302500-6, for example, terephthalic acid, p-hydroxybenzoic acid and biphenol are 1: 3: 1, 1: 5: 1, 1: 7: 1 and 1 : 3.5: 1. Physical resins mixtures using varying reagent ratios are also suitable for use.

The composition of the present invention can be prepared by extrusion according to well known techniques. For example, a twin screw extruder can be used by adding the polymer, the special talc and the titanium dioxide into the feed port 10 and by adding the glass spin in both the discharge port and the feed port.

The compositions thus prepared can then be injection molded into the desired articles using conventional techniques.

The invention is now further illustrated by the following examples, in which, unless otherwise indicated, all parts and percentages are by weight.

Example I

This example illustrates the synthesis of a copolyester to be used according to the present invention.

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

_Quantity

Designation Ingredient_ Grams Mol 25 A p-hydroxybenzoic acid 138 1 B phenyl acetate 170 1.25 C Therminol 77 500 D diphenyl terephthalate 318 1 E hydrochloride - - 30 F hydroquinone 111 1.01 G Therminol 77 500

Components A-D were placed in a four neck round bottom equipped with thermometer, stirrer, combined nitrogen and hydrogen chloride inlet and a drain connected to a condenser. Nitrogen was slowly introduced through the inlet. The flask and contents were heated to 180 ° C

8302500-7 - after which HCl was bubbled through the reaction mixture. The outlet neck temperature was maintained at 110-120 ° C by external heating during the exchange reaction of p-hydroxybenzoic acid and phenylacetate ester.

The flask with contents was kept at 180 ° C for 6 h

stirred, then the HCl feed was shut off, the temperature of the discharge neck was raised to 180-190 ° C, and the mixture was stirred at 220 ° C for 3.5 h. Until now, 159 g of distillate were collected in the condenser. Component F10 was added thereto and the temperature was gradually increased from 220 ° C to 320 ° C over a period of 10 h (10 ° C / h). Stirring was continued at 320 ° C for 16 h and then at 340 ° C for an additional 3 h to form a slurry. The total amount of distillate, which consisted of phenol, acetic acid and phenyl acetate, was 384 g. Component G was then added and the reaction mixture was allowed to cool to 70 ° C. Acetone (750 ml) was added and the suspension was filtered, after which the solids were extracted with acetone to remove components C and G in a Soxhlet apparatus. The solids were dried under vacuum at 110 ° C overnight, after which the copolyester thus obtained (320 g, 89.2% of theory) was collected in the form of a granular powder.

Example II

Mixed together were 518 parts of isophthalic acid, 1,557 parts of terephthalic acid, 5,175 parts of para-hydroxybenzoic acid, 6,885 parts of acetic anhydride and 2,325 parts of ρ, ρ'-bisphenol and heated under reflux at a temperature of about 180 ° C for 17 h, after which the condenser was replaced with a distillation setup and the temperature was raised to 345 ° C over a period of 1 h 15 min. The reaction mixture was stirred throughout the heating period, particularly vigorously during the period when the temperature was heated to 345 ° C. The polymer yield was 8,020 parts and 8,010 parts of distillate were collected. The contents were taken from the reaction vessel, cooled and ground to particle size in the range of 0.088-0.84 mm. The resin thus obtained 8302500-8% had a molecular weight in the range 5,000-20,000 / with an average molecular weight somewhere in the middle of this range. The product was estimated to be about 50% crystalline.

The resin particles were stored under vacuum at elevated temperature and at an absolute pressure of about 100 mmHg for 8 h and recovered in the form of a granular powder.

Example III

The following amounts of the following ingredients 10 were combined as indicated.

_Quantity

Designation Ingredient _ Grams Mol A terephthalic acid 291 1.75 B p-hydroxybenzoic acid 483 3.50 15 C ρ, ρ'-bisphenol 325 1.75 D acetic anhydride 755 7.40

Components A-D were heated to 145 ° C and refluxed overnight. The condenser was replaced with a distillation attachment. The mixture was heated under stirring at a rate of 20 ° C / h to 300 ° C, whereupon the contents were removed from the reaction vessel. At this time, approximately 92-94% of the theoretical amount of acetic acid had been collected. The prepolymer was ground and further treated as in Example II, using a temperature of ca.

250-375 ° C.

Example IV

_Quantity

Designation Ingredient_ Grams Mol A p-hydroxybenzoic acid 276.0 (2.00) 30 B terephthaloyl chloride 203 1.0 C trimesic acid 8.4 0.040 D Therminol 66 1274 E ρ, ρ'-bisphenol 186 1.0 F acetic anhydride 224.6 2 , 2 8 3 0 2 5 0 Ö

_____A

- 9 -

Components A-D were heated to 130 ° C and held at this temperature for 1 h. The reaction was exothermic and the temperature was carefully kept at 130 ° C. The contents of the flask were then heated at 155 ° C for 1 h and at 180 ° C for 4 h. The mixture was then cooled to 150 ° C and component E was added, further lowering the temperature to 140 ° C. At that time, component F was added. The mixture thus obtained was then refluxed at 155 ° C for 1 h, whereupon on the condenser was replaced with a distillation column.

With the distillation of the acetic acid formed, the contents of the reaction vessel were heated to 330 ° C and kept at that temperature for 3 hours. The suspended polymer was then cooled to 250 ° C and the mixture was filtered. The solid material was worked with trichlorethylene to remove the heat transfer fluid. The dried powder was further vacuum treated as shown in Example II.

Examples V, VI and VII

The procedure of Example III was repeated using the indicated amounts of the indicated ingredients.

Amount in moles

Designation Component_ Ex V Ex VI Ex. VII

A terephthalic acid 111 25 B p-hydroxybenzoic acid 345 C ρ, ρ'-bisphenol 111 D acetic anhydride

Example VIII

Combined, 268 parts of bisphenol, 396 parts of para-hydroxybenzoic acid, 693.40 parts of acetic anhydride and 238 parts of terephthalic acid were heated to a temperature of 315 ° C over a period of 5 h with a temperature rise of 30 ° C per hour. The reaction mixture was stirred throughout the heating period. When the temperature had reached 315 ° C, the polymer content was taken from the reaction vessel and ground to a particle size in the range of 0.074-0.84 mm.

-------- ^ \ 8302500 - 10 - * *

The resin particles were further processed in an oven with a stepwise increase in temperature to 354 ° C over a 16 hour period and recovered in the form of a granular powder.

Example IX

A molding composition was prepared from the polymer of Example VIII by extrusion of a mixture of 257.5 parts of polymer in this Example VIII, 30 parts of rutile titanium dioxide and 212.5 parts of a high purity talc with the plate-like structure of natural talc, a loss on branding of 2 wt%, an iron content of Fe2C> 3 of 0.5%, and a particle size distribution in which more than 95% of the particles were less than 40 m.

The resulting mixture was injection molded into trays with a uniform, pleasant appearance, which showed no cracks or fissures or flaking at minimum temperatures of about 260 ° C.

Some of the molded articles were subjected to a staining test in which a tuft of barbecue sauce was placed on the bottom of the molded container. The container was then placed in a preheated oven to 175 ° C for 1 h. The sauce became thick, dark and crusty. After cooling, the container was washed with soap and water using a Scrunge sponge. The container was examined for coloration and the color difference between the colored and uncolored areas was observed. The difference found was very small.

Some other samples were subjected to a drop test, with five samples being dripped on the top of their outer circumference from continuously increasing heights to determine the extent to which they were able to withstand the drop impacts with no discernible damage. The average for these samples was 100 cm.

The results of these tests all indicate the suitability of the molded articles for use as refractory kitchenware.

8302500 »»? - 11 -

Example X.

A molding composition was prepared from a polymer prepared according to Example VIII by extrusion of a mixture of 271 parts of polymer and 10 parts of the talc used in Example IX.

The resulting mixture was injection molded at a screw speed of 100 rpm, an injection pressure of 14 MPa and at temperature settings of 355 ° C in Zone 1, 360 ° C in Zone 2 and 345 ° C in Zones 3 and 4.

Molded articles with generally pleasant appearance were obtained.

Examples XI-XVIII

In these examples, 257.5 parts of the resin products of Examples I-VIII were mixed with 202.5 parts of the talc used in Example IX and 40 parts of rutile titanium dioxide by passage through a twin screw extruder. The reinforced resinous compositions thus obtained were injection molded. The molded articles thus obtained were satisfactory in appearance and cracking and flaking resistance at elevated temperatures.

8302500 ---

Claims (43)

1. Refractory refractory kitchenware, characterized in that it contains a shaped aromatic polyester composition, which composition consists of about 35-65% of aromatic polyester and about 1-60% of a talc with a minimum content of materials decomposable at elevated temperatures. Kitchen utensils according to claim 1, characterized in that the aromatic polyester is an oxybenzoyl polyester. Kitchen utensils according to claim 2, characterized in that it contains about 2-20% rutile titanium dioxide. Kitchen utensils according to claim 3, characterized in that the talc is a talc with a weight loss on branding of no more than about 6% at 950 ° C, and an iron content, determined as iron oxide, of no more than 1%. Kitchen utensils according to claim 4, characterized in that the amount of talc in the composition is 35-55%. Kitchen utensils according to claim 5, characterized in that the amount of rutile titanium dioxide is 5-15%. Kitchen utensils according to claim 4, characterized in that the talc is selected from the group consisting of high-purity talc, highly purified talc, calcined talc and acid-treated talc. Kitchen utensils according to claim 3, characterized in that the oxybenzoyl polyester contains recurring units selected from the group consisting of one or more of the formulas 1, 2,3, 4, 5 or 6 of the formula sheet, wherein X - O, S, - yy * -, NH or SO ~ and n = 0 or 1, and the sum of C ^ the integers p + q + r + s + t + u in units present is between 3 and 800. Kitchen utensils according to claim 8, characterized in that the ratios of q / r, q / u, t / t, t / u, q + t / r + u and t / t + u are between 10/11 and 11/10. Kitchen utensils according to claim 9, characterized in that the ratio is 10/10. 8302500 - 13 - • * Kitchen utensils according to claim 2, characterized in that the oxybenzoyl polyester has repeating units with each of formulas 7, 8 and 9 of the formula sheet, wherein x = -0- or -SO2-; m = 0 or 1? n = 0 or 1; 5 q: r = 10:15 to 15:10; p: q = 1: 100 to 100: 1; p + q + r = 3 to 600, wherein the carbonyl groups of the unit of formula 7 or 8 are bonded to the oxy groups of the unit of formula 7 or 9 and the oxy groups of the unit of formula 7 or 9 are bonded to the carbonyl groups of the unit of formula 10 or 8. Kitchen utensils according to claim 2, characterized in that the oxybenzoyl polyester has recurring units of formula 10 of the formula sheet. Kitchen utensils according to claim 7, characterized in that n = 0. Kitchen utensils according to claim 10, characterized in that p + q + r = 20 to 200. Kitchen utensils according to claim 1, characterized in that the talc is a highly purified talc. Kitchen utensils according to claim 1, characterized in that the talc is a calcined talc. Kitchen utensils according to claim 1, characterized in that the talc is an acid-treated talc. 18. Kitchen utensils according to claim 1, characterized in that the talc is a very pure talc. 19. A method of preparing food in a fixed cooker for repeated use, wherein the food in the cooker is heated to serving temperature, characterized in that the food is placed in a shaped article made of an aromatic polyester composition, which composition contains 35-65% aormatic polyester and 1-60% talc containing a minimum content of materials decomposable at elevated temperatures. 20. Process according to claim 19, characterized in that the aromatic polyester is an oxybenzoyl polyester. Process according to claim 20, characterized in that the oxybenzoyl polyester composition contains 2-20% rutile titanium dioxide. ----- yes 8302 500 V V% - 14 - A method according to claim 21, characterized in that the talc is a talc with a weight loss on branding of not more than 6% at 950 ° C and an iron content of iron oxide of not more than 1%. A method according to claim 22, characterized in that the amount of talc in the composition is 35-55%. A method according to claim 23, characterized in that the amount of rutile titanium dioxide is 5-15% 10. A method according to claim 22, characterized in that the talc in the oxybenzoyl polyester composition is selected from the group consisting of highly purified talc, calcined talc and acid treated talc. 26. Process according to claim 21, characterized in that the oxybenzoyl polyester contains recurring units of one or more of the formulas 1, 2, 3, 4, 5 and 6 of the formal leaf, wherein x = 0, S, - j? -, NH or SC ^, and n = 0 or 1 and the sum of the integers p + q + r + s + t 20 + u in the units present is between 3 and 800. A method according to claim 26, characterized in that the ratios of q / r, q / r, t / t, t / u, q + t / r, q + .t / r + u and t / t + you are between 10/11 and 11/10. 28. The method of claim 27, wherein the ratio is 10/10. 29. Process according to claim 20, characterized in that the oxybenzoyl polyester has recurring units of any of the formulas 7, 8 and 9 of the formula sheet, wherein x = -O- or -SC ^ -, m = 0 or 1, n = 0 or 1, 30 q: r = 10:15 to 15:10, p: q = 1: 100 to 100: 1, p + q + r = 3 to 600, where the carbonyl groups of the unit of formula 7 or 8 bonded to the oxy groups of the unit of formula 7 or 9 and the oxy groups of the unit of formula 7 or 9 are offered to the carbonyl groups of the unit of formula 7 or 8. A method according to claim 22, characterized in that the heat source is thermal. 8302500 ^> <7 - 15 - A method according to claim 22, characterized in that the heat source is short wave. A method according to claim 26, characterized in that the heat source is thermal. 33. A method according to claim 26, characterized in that the heat source is short wave. 34. Polyester molding composition, characterized in that it comprises 35-65% aromatic polyester, and 1-60% of a talc containing a minimal content of materials decomposable at elevated temperatures. A composition according to claim 34, characterized in that the aromatic polyester is an oxybenzoyl polyester. 36. A composition according to claim 34, characterized in that it contains 2-20% rutile titinium dioxide. The composition according to claim 36, characterized in that the talc is a talc with a weight loss on branding of not more than 6% at 950 ° C and an iron content of iron oxide of not more than 1%. A composition according to claim 37, characterized in that the amount of talc in the composition is 35-55%. 39. A composition according to claim 38, characterized in that the amount of rutile titanium dioxide is 5-15%. The composition according to claim 37, characterized in that the talc is selected from the group consisting of high purity talc, highly purified talc, calcined talc and acid treated talc. The composition according to claim 37, characterized in that the polyester contains recurring units of one or more of the formulas 1, 2, 3, 4, 5 and 6 of the formula sheet, wherein x = O, S, - ^ - , NH or SO2, and n = 0 or 1 and the sum of the integers * 'p + q + r + s + t + uin the 35 units present is between 3 and 800. 42. A composition according to claim 37, characterized in that the oxybenzoyl polyester contains recurring units of each of formulas 7, 8 and 9 of the form 8302500-16 mule sheet, wherein x = -O- or -SC ^ - , m = 0 or 1, n = Oor 1, q: r = 10:15 to 15:10, p: q = 1: 100 to 100: 1, p + q + r = 3 to 600, where the carbonyl groups of the unit of formula 7 or 8 are bound to the oxy groups of the unit of formula 7 or 9 and the oxy groups of the unit of formula 7 or 9 are bound to the carbonyl groups of the unit of formula 7 or 8. The composition according to claim 37, characterized in that the oxybenzoyl polyester contains recurring units of formula 10 of the formula sheet. % 8302500