HK1184805B - Lubricant combination for the processing of thermoplastic resins - Google Patents

Description

The present invention relates to a thermoplastic composition, a process for the production of a thermoplastic composition, the thermoplastic composition obtained by this process, a process for the production of a mould based on a thermoplastic composition, a mould obtained by this process and the use of a reaction mixture.

Thermoplastic polymers are very popular in the manufacture of moulds of all kinds. The processing of thermoplastic polymers into such moulds usually takes place in several steps, usually at least one of which involves heating the polymer, often to a temperature at which the thermoplastic polymer has a rheological profile sufficient for further processing. Further processing steps often involve an intensive mixing of thermoplastic polymers and other ingredients and a cutting of the polymer.

Err1:Expecting ',' delimiter: line 1 column 876 (char 875)

Err1:Expecting ',' delimiter: line 1 column 170 (char 169)

Err1:Expecting ',' delimiter: line 1 column 47 (char 46)

For environmental and economic reasons, the direct use of saturated triglycerides such as cured tallow or cured turnip oil as lubricants would be particularly advantageous, but these compounds have a very external effect (see Becker/Braun, Plastics Handbook Volume 2/1, Carl Hanser Verlag 1986, pp. 570-595) and cannot be used as such.

The present invention was based on the objective of overcoming at least part of the disadvantages of thermoplastic moulds resulting from the state of the art.

In particular, the present invention was intended to specify a thermoplastic composition lubricant based on renewable raw materials which is environmentally beneficial and which has a particularly strong internal lubricant effect and which can be manufactured from renewable raw materials in the simplest possible way.

The lubricant should also be particularly well tolerated, in particular with polyvinyl chloride.

The lubricant or a thermoplastic composition containing the lubricant should also be characterised by a particularly high thermal stability.

A thermoplastic composition including a thermoplastic material is a contribution to the solution of the problems mentioned at the beginning of this section. (a) at least one thermoplastic polymer, (b) at least one lubricant and (c) other additives where appropriate, where at least one lubricant is a reaction mixture obtained by conversion of a component containing saturated triglycerides with a primary alcohol, where the reaction mixture contains, in addition to the digestion product (fatty acid ester and primary alcohol), partial esters of glycerol, untranslated primary alcohol and untranslated triglyceride, and where the primary alcohol is a polyol with more than two OH groups.

Surprisingly, saturated triglycerides re-esterified with primary alcohols were found to be an internal lubricant in the processing of thermoplastic plastics without adversely affecting the rheological properties. In addition, these products improve the achievable thermal stability of the finished products. The lubricants consist of a high proportion of renewable raw materials and are therefore environmentally beneficial.

The composition of the invention shall include as a component (a) at least one thermoplastic polymer. For example, a suitable thermoplastic polymer shall be selected from the group consisting of polyvinyl chloride (PVC), polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polylactate (PLA), polycarbonate, polyrol, polyurethane, polyether, rubber, preferably polyisoprene, rubber, especially NBR rubber, polyadiene, copolymers of at least two of the above, in particular polypropylene/polybutylene copolymers and mixtures of at least two. To avoid this, PVC, PLA and PVC are preferably made of at least two.

In a design according to the invention, the thermoplastic composition according to the invention does not melt below 80°C, preferably at or below 140°C and preferably at or below 270°C. In most cases, the thermoplastic compositions according to the invention are preferred to melt at 350° or less. In thermoplastic compositions according to the invention, thermoplastic polymers with similar melting properties are used at a minimum of 50%, preferably at a minimum of 75% by weight and preferably at a minimum of 90% by weight, each in relation to the total weight of the thermoplastic composition.

A thermoplastic composition of the invention preferably contains at least 50% by weight of at least one thermoplastic polymer, in relation to the total weight of the thermoplastic composition. The upper limit for the content of thermoplastic polymers may be, for example, 99,999% by weight, in relation to the total weight of the thermoplastic composition, or less, for example, 98%, 96%, 94%, 92%, 90%, 90%, or less, in relation to the total weight of the thermoplastic composition. It may also be more or less than or equal to 18, 15%, 35%, or less, in relation to the total weight of the thermoplastic composition.

A composition of the invention has thermoplastic properties, but this does not preclude a thermoplastic composition of the invention from containing a proportion of non-thermoplastic polymer components, such as a proportion of duromers (often referred to in the literature as duroplasts), but at a maximum of an amount at which the thermoplastic properties of the composition as a whole are not adversely affected to such an extent that thermoplastic processing is not possible or only entails serious disadvantages.

The composition of the invention continues to contain as a component (b) at least one lubricant, the lubricant being a reaction mixture preferably obtained by conversion of a component containing saturated triglycerides with a primary alcohol, which, in addition to partial esters of glycerol, contains an ester of fatty acids and the primary alcohol.

The preferred component containing triglycerides is natural or cured oils and fats of vegetable or animal origin, and according to the invention, oils or fats with a triglyceride content greater than 50% by weight, preferably greater than 75% by weight and preferably greater than 90% by weight, respectively, by reference to the total weight of the oil or fat, are preferred.

Furthermore, according to the invention, it is preferable to use a triglyceride component for the manufacture of the lubricant, based on an iodine content of less than 20 by weight, preferably less than 10 by weight and preferably less than 5 by weight, based on oils and fats, based on the total weight of the triglyceride component, at least 75 by weight, preferably at least 85 by weight and most preferably at least 95 by weight, respectively.

Such fats and oils may occur naturally or be obtained by hydration of natural fats and oils with a higher percentage of unsaturated fatty acids and thus a higher iodine content. An example of naturally occurring fats and oils with iodine content below 20 may be coconut oil, which may vary naturally in fatty acid composition depending on the crop and growing region, and for the purposes of the invention only natural coconut oil with iodine content below 20, preferably below 10 is suitable.

Other suitable natural fats and oils with iodine levels below 20 are obtained by hydrogenation of the double bonds of the unsaturated fatty acids in natural fats and oils in a known way. For hydration, natural oils and fats are suitable as palm oil, palm kernel oil, coconut oil, olive oil, old and new cultivars' rubber oil, old and new cultivars' sunflower oil, flax oil, peanut oil, cotton seed oil, coriander oil, meadow foam oil, lard oil, beef and fish oil, chaulmograa oil, palm oil, but especially coconut oil. Both the hydrated fats and oils with iodine 20 are also the base oil of the natural coconut oil, which is also based on the natural oil of ricin, and must be obtained from at least two or three mixtures of these oils, which are still used in the market.

A primary alcohol which is incorporated into the lubricant with the triglyceride component is preferably an alcohol which has at least one structural unit -CH2-OH. This primary alcohol is a polyol with more than two OH groups, for example a polyol with three or four OH groups. The preferred primary alcohols are selected from the group consisting of trimethylolopanprol, pentaerythritol, dipentaerythritol and a mixture of at least two of these.

The conversion of the primary alcohol into the triglyceride component is preferably aimed at triglyceride re-acidification. For this reason, it is preferable to convert the saturated triglyceride component into the primary alcohol in the presence of a base as catalyst. The base is in particular hydroxides, oxides or carbonates of an alkali or earth alkali metal or alkali alkoxylates, such as sodium methylate, sodium methylate or alkali alkoxylates of the above primary alcohol compounds, with the use of a particularly preferable base selected from the group consisting of NaOH, a KOOH, LiH or a mixture of at least two of these.

Furthermore, in the context of lubricant manufacture, it is preferable to incorporate the saturated triglyceride component with the primary alcohol in a weight ratio in the range of 50:50 to 99:1; particularly preferably in the range of 60:40 to 98:2; and most preferably in the range of 70:30 to 95:5.

Furthermore, in the context of lubricant manufacture, it is preferable to incorporate the saturated triglyceride component with the primary alcohol at a temperature in the range of 100 to 300 °C, preferably in the range of 150 to 280 °C and most preferably in the range of 200 to 250 °C.

It has now been shown to be particularly advantageous, according to the invention, when the reaction mixture obtained after degreasing, which contains, in addition to the degreasing product (fatty acid ester and primary alcohol), partial esters of glycerol and unconverted primary alcohol, unconverted triglyceride and, where appropriate, the base used as a catalyst, is used directly as a lubricant component (b) without further purification.

The lubricant described above is preferably contained in the thermoplastic composition of the invention in a quantity in the range of 0,001 to 10 g/cm3, preferably between 0,1 and 5 g/cm3 and most preferably between 0,3 and 3 g/cm3 respectively by the total weight of the thermoplastic composition.

(c) Other additives may be used as components in the composition of the invention, the additive being preferably one of the additives selected from the group consisting of fillers, pigments, stabilizers, other lubricants, plasticizers, anti-lockers, anti-fouling agents, antistatic agents, flame retardants, propellants, fats, oils, antioxidants, acid catchers, nucleating agents, solvents and a mixture of at least two of them.

Pigments are generally any inorganic or organic pigment which is compatible with the thermoplastic composition as such and in particular with the thermoplastic composition in the context of the intended processing. Pigments may give a colour to the thermoplastic composition, but pigments which colour the thermoplastic composition white or black are also suitable. Pigments which are particularly suitable are, for example, titanium dioxide, pigments based on zirconium oxide, barium sulphate, zinc oxide (zinc white) and lithone (zinc sulphate/barium sulphate), soot, rubber-titanium mixtures, iron oxides, antimony oxide, chromium oxide, spironite, cobalt blue and azithromycin, pigments such as cadmium oxide, cadmium oxide, pyrol or anthracene, pigments such as cadmium oxide, anthracene, anthracene, or pigments such as pigments of anthracene, cadmium oxide, or pigments of anthracene.

Fillers are in particular calcium carbonate, dolomite, gypsum, wolastonite, magnesium oxide, magnesium hydroxide, silicates, china clay, tallow, glass fibres, glass balls, wood balls, mica, metal oxides or metal hydroxides, soot, graphite, rock flour, heavy spatter, glass fibres, tallow, kaolin or chalk or metal sulphates, such as heavy metal sulphates, which may have a stabilising effect on the thermoplastic composition in addition to a filling or pigmentation effect.

The proportion of pigments or fillers or mixtures of one or more pigments and one or more fillers in the total thermoplastic composition may be up to about 50% by weight, depending on the thermoplastic composition. The invention provides that a thermoplastic composition contains only small amounts of pigments or fillers, for example, 0,5 to about 10 or 1 to about 5%. However, it is also possible that a thermoplastic composition according to the invention contains larger amounts of pigments or fillers or mixtures thereof, for example, about 10 to about 50% by weight or about 20 to about 40%, respectively, depending on the total weight of the thermoplastic composition.

Stabilizers prevent plastics such as PVC from decomposing or changing chemically at high temperatures, thus improving weather resistance.

Other lubricants are used to facilitate polymer processing by reducing friction between polymer chains and reducing the adhesion of the melt to the walls.

Many plasticizers belong to the group of phthalates (DEHP, DINP and DIDP), as well as the adipate and citrate groups.

Anti-fouling agents are used to prevent the formation of surface cloudiness caused, for example, by water droplets, and are published in, for example, DE 10 2004 038 980 A1 and Plastics Additives Handbook, 5th Edition, Hanser Verlag, pp. 609 to 626, and are available from Emery Oleochemicals GmbH.

Err1:Expecting ',' delimiter: line 1 column 93 (char 92)

Water or organic solvents such as alcohols, such as polyglycol, in particular polyethylene glycol or polypropylene glycol, or a mixture of the above, may be used as solvents.

According to a particular embodiment of the thermoplastic composition of the invention, it contains: (a) 50 to 99,999 weight %, preferably 60 to 94,9% and preferably 70 to 89,7% by weight of at least one thermoplastic polymer; A process for the production of a thermoplastic composition by contacting at least one of the following composition components also contributes to solving the tasks mentioned at the outset: (a) 50 to 99,(b) 0,001 to 10%, in particular, 0,1% to 5% by weight and 0,3% to 3% by weight, in particular, by weight, of the total thermoplastic composition, of at least one lubricant and (c) 0 to 49,999%, in particular, 5 to 39,9% by weight and 10 to 29,7% by weight, in particular, of the total thermoplastic composition, of at least one additive, whereby the sum of the components A to C is 100% by weight and whereby the thermoplastic componentsThe preferred lubricants and additives are those compounds which were previously mentioned as preferred thermoplastic polymers, lubricants and additives in connection with the thermoplastic composition of the invention.

The simplest way of bringing the components A, B and C into contact is by simply mixing the three components dry (dry mixing), whereby at least one thermoplastic polymer can be used, for example, as a granulate, or by heating at least one thermoplastic polymer above its melting point and thus melting it, and then incorporating the components B and C into the melt (melt mixing), after which the mixture can be cooled and, if necessary, converted into a granular form.

A thermoplastic composition obtained by the process described above also contributes to the solution of the problems mentioned at the beginning, preferably if this thermoplastic composition has the same properties as the thermoplastic composition of the invention described at the beginning.

A process for the manufacture of a mould continues to contribute to the tasks mentioned at the outset, including the following steps: (ii) heating the thermoplastic composition to the glass transition temperature of the thermoplastic polymer or to a temperature above the glass transition temperature of the thermoplastic polymer; (iii) manufacture of a mould from the thermoplastic composition obtained in step II)

In step I) of the method of manufacture of a mould, a thermoplastic composition of the invention or a thermoplastic composition obtained by the method of the invention is first provided.

In this context, it is again preferable to heat the thermoplastic composition to a temperature in the range of 5° below the glass transition temperature (Tg) to 100°C above the glass transition temperature of the thermoplastic polymer used, preferably to a temperature in the range of 1° above the glass transition temperature (Tg) to 50° above the glass transition temperature (Tg), with most thermoplastic polymers being heated to a temperature in the range of 1° below the glass transition temperature (Tg) to 20°C, but also to a temperature in the range of 1° above the glass transition temperature (Tg) to 50°C above the glass transition temperature (Tg), whereby the thermoplastic polymer is inserted and the temperature is in the range of 1° below the glass transition temperature (Tg) to 20°C, but also within the thermoplastic polymer's upper boundary, but not exceeding the thermoplastic transition temperature (Tg).

In principle, the steps I and II can be performed simultaneously or in succession. For example, it is useful to perform steps I and II simultaneously if the thermoplastic composition is produced by a melt-blending process. In this case, it may be advantageous to transfer the composition produced by the melt-blending process directly into a mould. For example, it is useful to perform steps I and II successively if the thermoplastic composition is produced by a dry-blending process or if the thermoplastic composition is produced by a melt-blending process but not immediately after the formation of a mould but is first cooled.

In step III of the method of manufacturing a mould according to the invention, the thermoplastic composition obtained in step II is heated to produce a mould, preferably a container, film, fibre, profile or tube. In particular, injection moulding, extrusion moulding, compression moulding, layer moulding, lamination moulding, hollow moulding, vacuum moulding and transfer moulding are considered as methods of manufacturing a mould, with particular preference being given to injection moulding.

Furthermore, it is consistent with the design of the method of manufacturing a thermoplastic mould according to the invention that at least one further process step (IV) at least a part of the mould obtained in process step (III) is used as mould grout and is reduced in its cross-section. The cross-section of the mould is the cross-section of a region of the mould consisting in the main of the thermoplastic mould mass according to the invention. For example, in the case of containers or bindings, the cross-section of the mould represents the thickness of a transformation of these containers or sections. In the case of moulds shaped more like threads or strands, the cross-section represents the thickness of these strands or strands.

In the case of flatter structures such as plates, sheets, plates, films or films, the cross-section represents the strength of the flatter structure. In general, all methods known to the skilled person and suitable for this purpose are used to reduce the cross-section. These include, for example, stretching in one or two directions, pulling in one or two directions, slinging or bubbling, preferably at elevated temperatures, where the thermoplastic composition of the vessels of the invention is so soft or even liquid that stretching, pulling slinging or bubbling can be carried out. The sub-area in which the cross-section is made up of the cutting makes up at least 80% of the body, preferably in the form of a step III.In the case of the production of films, the drawing or stretching can be carried out in one or more dimensions. For example, the track running from an extruder can be drawn on a roller at a higher speed than the exit speed from the extruder.It is still possible for two or more of the steps (I) to (IV) to be supplemented by further steps and/or at least overlapping in time. This is particularly the case for steps (III) and (IV).

A further contribution to the solution of the problems mentioned at the outset is made by a mould obtained by the process described above.

Finally, the use of the reaction mixture described in connection with the thermoplastic composition of the invention as a lubricant in thermoplastic compositions also contributes to the solution of the problems mentioned at the outset.

The solution is now explained in more detail by means of non-limiting examples.

Example 1:Desturation of cured tallow with trimethylolpropane

518.3 g of cured sebum (iodine < 1), 81.7 g trimethyl propane and 0.061 g LiOH × H2O were presented in a glass flask and heated to 240 °C by stirring.

Err1:Expecting ',' delimiter: line 1 column 51 (char 50)

Example 2:Cured tallow treated with pentaerythritol

517.2 g of cured sebum (iodine < 1), 82.8 g of pentaerythritol and 0.06 g of LiOH × H2O were presented in a glass flask and heated to 240 °C by stirring.

Err1:Expecting ',' delimiter: line 1 column 51 (char 50)

The acidity is 0.22 and the acidity is 170.0.

Example 3:Mestering of tallow with triethylene glycol

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Examples 4-7:Manufacture of a thermoplastic composition according to the invention

A dry mixture was produced from PVC powder and various additives in a Henschel blender (material quantity = 3 kg, heating temperature = 120°C, subsequent cooling), the compositions of which are given in the following table. Other

Beispiel	4	5	6	7
PVC Evipol SH 6520	100	100	100	100
Bleisulfat 3-basisch	3	3	3	3
Bleistearat 28%	0,5	0,5	0,5	0,5
Calciumstearat	0,5	0,5	0,5	0,5
Distearylphthalat	1
Umesterungsprodukt aus Beispiel 1		1
Umesterungsprodukt aus Beispiel 2			1
Umesterungsprodukt aus Beispiel 3				1

Other Examples 5 to 7 are as follows:

Manufacture of flat-rolled products of iron or non-alloy steel

The dry blends from examples 4 to 7 were extruded onto a flat strip on a double-slotted extruder from Weber (extrusion parameters: speed = 15 UpM (B1-B3), 25 UpM; temperature = 180°C). Other

Beispiel	Maschinenbelastung (%)	Massedruck (bar)
4	49	382
5	46	362
6	48	365
7	49	376

The products of the invention are comparable to the standard lubricant disteryl phthalate and reduce the mass pressure in the extruder without changing the machine load.

The thermal stability was determined from the extruded data according to EN 60811-3-2: 1995 paragraph 9 (Kongorot test) at 200°C. Other

Beispiel	Stabilität [min]
4	46
5	51
6	51
7	51

The lubricants used in accordance with the invention result in a better thermal stability than the standard.

Claims (20)

1. A thermoplastic composition including

   a) at least one thermoplastic polymer,

   b) at least one lubricant, and also

   c) optionally other additional substances,

   wherein the at least one lubricant is a reaction mixture which is obtainable via the reaction of a primary alcohol with a component including saturated triglycerides, wherein the reaction mixture, which in addition to the transesterification product (ester of fatty acid and primary alcohol), also comprises partial ester(s) of glycerol, unreacted primary alcohol and unreacted triglyceride, and wherein the primary alcohol is a polyol having more than two OH groups.
2. The thermoplastic composition according to Claim 1, wherein the component including triglyceride is selected from the group consisting of coconut oil, palm kernel oil, hardened tallow, hardened rapeseed oil, hardened palm stearin, hardened castor oil and a mixture of at least two thereof.
3. The thermoplastic composition according to Claim 1 or 2, wherein the component including triglycerides is based to an extent of at least 75% by weight, based on the total weight of the component including triglycerides, on oils and fats with an iodine number of less than 20.
4. The thermoplastic composition according to any of the preceding claims, wherein the primary alcohol is selected from the group consisting of trimethylol-propane, pentaerythritol, dipentaerythritol and a mixture of at least two thereof.
5. The thermoplastic composition according to any of the preceding claims, wherein the reaction of the primary alcohol with the component including saturated triglycerides takes place in the presence of a base.
6. The thermoplastic composition according to Claim 5, wherein the base is a hydroxide, an oxide or a carbonate of an alkali metal or of an alkaline earth metal or is an alkali metal alkoxylate.
7. The thermoplastic composition according to Claim 6, wherein the base is selected from the group consisting of NaOH, KOH, LiOH and a mixture of at least two thereof.
8. The thermoplastic composition according to any of the preceding claims, wherein the component including saturated triglycerides is reacted with the primary alcohol in a ratio by weight in the range from 50 : 50 to 99 : 1.
9. The thermoplastic composition according to any of the preceding claims, wherein the reaction of the primary alcohol with the component including saturated triglycerides takes place at a temperature in the range from 100 to 300°C.
10. The thermoplastic composition according to any of the preceding claims, wherein the thermoplastic polymer is selected from the group consisting of polyvinyl chloride, polypropylene, polyethylene, polyethylene terephthalate, polylactate, polycarbonate, polystyrene, polyurethane, polyether, rubber and copolymers of at least two of the above.
11. The thermoplastic composition according to any of the preceding claims, wherein additional substance present comprises at least one additional substance selected from the group consisting of fillers, pigments, stabilizers, further lubricants, plasticizers, antiblocking agents, antifogging agents, antistatic agents, flame retardants, blowing agents, fats, oils, antioxidants, acid scavengers, nucleating agents, solvents and a mixture of at least two thereof.
12. The thermoplastic composition according to any of the preceding claims, wherein the composition comprises an amount of about 0.001 to about 10% by weight of the lubricant, based on the total weight of the thermoplastic composition.
13. The thermoplastic composition according to any of the preceding claims, wherein the thermoplastic composition comprises

    a) at least 50 to 99.999% by weight of the at least one thermoplastic polymer,

    b) 0.001 to 10% by weight of the at least one lubricant and

    c) 0 to 49.999% by weight of the further additional substances,

    based in each case on the total weight of the thermoplastic composition, wherein the entirety of components a) to c) is 100% by weight.
14. A process for the production of a thermoplastic composition by bringing at least the following composition components

    A) at least 50 to 99.999% by weight, based on the total weight of the thermoplastic composition, of at least one thermoplastic polymer;

    B) 0.001 to 10% by weight, based on the total weight of the thermoplastic composition, of at least one lubricant as defined in Claims 1-13; and

    C) 0 to 49.999% by weight, based on the total weight of the thermoplastic composition, of at least one additional substance

    into contact, wherein the entirety of components A) to C) is 100% by weight.
15. A thermoplastic composition obtainable via the process according to Claim 14.
16. A process for the production of a moulding, including the steps of:

    I) the provision of a thermoplastic composition according to any of Claims 1 to 13 or 15,

    II) the heating of the thermoplastic composition to the glass transition temperature of the thermoplastic polymer or to a temperature above the glass transition temperature of the thermoplastic polymer;

    III) the production of a moulding from the heated thermoplastic composition produced in step II).
17. The process according to Claim 16, wherein, in a further step IV), the mass cross section of at least one sub-region of the moulding obtained in step III) is reduced in comparison with step III).
18. The process according to Claim 16 or 17, wherein the moulding is selected from a group consisting of a container, a foil, a fibre, a profile and a tube.
19. A moulding obtainable via a process according to any of Claims 16 to 18.
20. The use of a reaction mixture obtainable via the reaction of a primary alcohol with a component including saturated triglycerides, as lubricant in thermoplastic compositions; wherein the reaction mixture, which in addition to the transesterification product (ester of fatty acid and primary alcohol), also comprises partial ester(s) of glycerol, unreacted primary alcohol and unreacted triglyceride, and wherein the primary alcohol is a polyol having more than two OH groups.