UA55521C2 - Thermoplastic polymeric composition - Google Patents

Abstract

Thermoplastic polymeric composition for sausage casing consists of one or mixture of polyamides and processing admixture; as such an admixture there is used a substance which is compatible with polyamide and is selected from aliphatic series with C6-C20 hydrocarbon chain length and aromatic carboxylic acids, sulfonic acids, full- and partly substituted esters of carboxylic acids and polyatomic alcohols, amides of aliphatic and aromatic acids, sulfanilamides, polyatomic or higher monatomic alcohols, oligomeric polyamides, lactams, polyalkyleneoxides with molecular mass about 20,000, esters thereof and mixtures of mentioned substances in amount of 0.01-0.5 mass percents, and which has a thermal stability up to 300°С. Polyamides 6, 12, 612, 66 or copolymers of polyamides are used as polyamides, and admixture is permitted for contact with food products. Composition may include dye, colorant and filling agent up to 10 mass percents.

Description

The invention relates to a new thermoplastic polymer mixture suitable for extrusion processing into an oriented product, in particular, oriented sleeve films for sausage and sausage casings. Sleeve film can include one or more polyamide layers or be completely made of this mixture.

Recently, single-layer and multi-layer biaxially oriented sleeve films containing layers based on synthetic polyamides have been increasingly used as casings for cooked sausage products. These shells are characterized by high barrier properties with respect to oxygen, mechanical strength, elasticity, the ability to tightly fit the product without forming wrinkles.

The technology for obtaining biaxially oriented sleeve films includes the following operations: 1. Preparation of a granular polymer mixture, which usually includes granules of the main polymer, polymer impurities and superconcentrates, and loading it into the extruder; 2. Melting of the polymer mixture, pushing it through a ring die and forming it in the form of a primary sleeve with a thickness of 250 - 270 μm; 3. Sharp cooling (hardening) of the primary sleeve with water at a temperature of 19 - 2170; 4. Heating the primary sleeve to a temperature of 55 - 7570; 5. Two-axis orientation hood with a multiplicity of 2.5 - 2.9 / 2.9 - 3.4 in the longitudinal and transverse directions, respectively; 6. Thermosetting of the finished sleeve at a temperature of 155 - 19570; 7. Cooling the sleeve and winding it into a roll.

The most serious technological problems arise during orientation extraction and are associated with sleeve breaks. They lead to large losses of raw materials and working time. These breaks occur due to insufficient plasticity of the primary sleeve, which is especially characteristic of films that contain red or black dyes in the polyamide layers.

In the end, the stage of the orientation hood determines the industrial rate of production of sleeve films.

Therefore, manufacturers of such films are forced to vary their composition, guided by the need to ensure the stability of the technical process, often to the detriment of consumer characteristics of the final product, such as strength and barrier properties.

Thus, to increase the plasticity of the primary sleeve, multicomponent compositions based on polyamides are used.

German patent Mo2850181 (class B650O81/34, A22C13, publ. 05/29/1980) claims a sleeve film made of an elongated mixture of shrinkable synthetic polymers, which contains at least one aliphatic polyamide, an ionomer resin and/or one modified ethylene copolymer with vinyl acetate. As a polyamide, it contains polycaproamide (PA 6), polyaminoenantoamide (PA 7), polyhexamethylene adipinamide (PAbb) and/or polyhexamethylene sebacinamide (PA 610) in the form of a mixture or in the form of a copolymer, and may additionally contain polyaminoundecanamide (PA 11) and/or polylaurinlactam ( PA 12), as a copolymer, for one or more polyamides named above. the onomer resin is a copolymer of ethylene with a p,p-unsaturated monocarboxylic acid, for example, (meth)acrylic acid. The introduction of ionomer resin contributes to the achievement of greater uniformity of the exhaust bubble and the absence of unextruded areas. At the same time, the use of ionomer resin is limited by the tendency of ionomers to thermal destruction, which leads to interruptions in the operation of single-screw extruders due to a large gap in the melting temperatures of the components, to inhomogeneity of the optical properties (in particular, gloss) of the film and to an increase in the tendency of the film to stick (block) in the roll .

When adding certain dyes and pigments, mainly red and black, in a concentration of more than 195% of the total mass, there are great difficulties associated with the uneven distribution of the pigment in the primary sleeve and an increase in its stiffness, in connection with which, its orientation hood often becomes impossible.

In patent ER 03251518! (class А22С13/00, publ. 07/26/1989) claims a biaxially oriented packaging film made on the basis of a polyamide composition containing dyes. The composition includes aliphatic polyamide, terephthalic acid polyester, aromatic polyamide and pigment in the ratio of 65 - 85:7-15:4-19: 0.5 - 10 (weight 95), respectively, and the proportion of aromatic polyamide is more acceptable equal to or greater than the weight dye particles. To ensure the ability of the primary sleeve to draw, an expensive aromatic polyamide pre-mixed with a dye is added to the polyamide-polyester mixture.

The introduction of aromatic polyamides into the composition in significant quantities significantly increases the cost and price of biaxially oriented sleeve polyamide-containing films.

Patent 5 3632728 (class B2907/24, publ. 04.01.1972) shows that the uniform thickness and homogeneity of a biaxially stretched flat polyamide film is achieved by using a blank polyamide film with a water content of more than 195% by weight of polyamide. At the same time, the use of this method is associated with the mutually exclusive requirements of a sufficiently long exposure of the workpiece in water and preservation of the amorphous state of polyamide, because water accelerates the crystallization of polyamide. In addition, it is technologically very difficult to ensure uniform wetting of the workpiece, without which it is impossible to obtain a film of uniform thickness.

Patent EP 00628208 (class СО89У5/18, publ. 05/28/1987) claims very thin flat polyamide films obtained by casting extrusion. Small amounts (0.001 - 0.295) of dispersion consisting of a solid initiator for the formation of crystallization centers and a liquid organic dispersant selected from the group of polyalkylene glycols, paraffin oils, ethers of carbocyclic acids, organopolysiloxanes, alkylated alkylphenols, alkylated fatty acids, alkylated amines and fatty acid amides. Crystallization initiators are barium sulfate, trisubstituted calcium phosphate, calcium chloride and talc. The advantages achieved by the introduction of crystallization center initiators into the polymer mixture during casting extrusion are an obstacle in the orientation of polyamide films obtained from the amorphous state. The disadvantages of this method include the additional stage of obtaining the dispersion, which is then mixed with polyamide granulate.

The closest technical solution to the proposed one is described in US patent 5534277 (class

A22C13/00, publ. 07/09/1996), which claims at least a three-layer film, the outer layers of which consist of a mixture of crystalline polyamide and an admixture that disrupts the crystallinity of the latter.

As such an admixture, a mixture of a second crystalline polyamide, different from the first crystalline polyamide, and an olefinic material is used. The first crystalline polyamide is selected from the group consisting of PA 6, PA 66, co-polyamides and ter polyamides. As a material that breaks the crystallinity of the first polyamide, it is most appropriate to use polyamide materials such as PA 11, PA 12, PA 610, PA 612 (polyhexamethylenedodecaneamide), copolymer PA 6/66 (copolyamide of caprolactam, hexamethylenediamine and adipic acid) and copolymer PA 66/610 (copolymer obtained from a mixture of monomers for PAbb and

PAb10). As such, olefinic materials can be used, such as copolymers of ethylene and an unsaturated acid, ethylene and an ether of an unsaturated acid, modified polymers and ionomers. However, the use of such a thermoplastic polymer mixture does not solve all the problems that arise in the orientation process, especially when the film thickness is less than 50 μm. The introduction of such an admixture, more acceptable in the amount - 4095, also affects the consumer properties of the manufactured film, including its strength, water and gas permeability. To overcome these shortcomings, it is necessary to produce a multilayer film instead of a single-layer film.

The task solved in this invention is the development of a new thermoplastic polymer mixture based on one or a mixture of several polyamides, which allows, when processed on conventional extrusion equipment (single-screw extruder), to ensure the stability of the process of orientation extraction without the introduction of additional technological operations and to obtain on its basis a sleeve a film that retains the high strength and barrier characteristics characteristic of polyamides.

The next task of the invention is to reduce the production cost and to obtain intensively and uniformly colored products with an improved appearance.

The solution to the given problem is achieved by the fact that in a thermoplastic polymer mixture consisting of one or a mixture of polyamides and a technological admixture, a substance compatible with polyamide is used as an admixture, selected from a number of higher aliphatic hydrocarbon chain lengths Св - Сго and aromatic carboxylic acids, sulfonic acids, fully and partially substituted esters of carboxylic acids and polyhydric alcohols, amides of aliphatic and aromatic acids, sulfonamides, polyhydric or higher monohydric alcohols, oligomeric polyamides, lactams, polyalkylene oxides with a molecular weight of up to 20,000, their esters and mixtures of these substances, and which has a thermal stability of up to 300 "7C in the amount of 0.01 - 0.595 wt.

It is advisable as polyamides, first of all, to use polyamides b, 12, 66, 612 or copolymers of polyamides or their mixtures.

It is more acceptable to use an admixture allowed to come into contact with food products.

The thermoplastic mixture can contain dye, pigment, filler up to 1095 wt.

Unlike both conventional and "structural" plasticizers, which sharply reduce the softening temperature and viscosity of polymer melts, the proposed additives practically do not change the extrusion conditions and do not deteriorate the strength and barrier characteristics of polymers. This enables their use in a conventional single-screw extruder without the introduction of additional technological stages of mixing.

When using the proposed additives in the declared quantities, the technologically necessary plasticity of the primary sleeve is achieved, which is manifested in the stability of the technical process, especially when obtaining films dyed in "problematic" colors. Reducing the number of breaks during orientation extraction leads both to an increase in the industrial speed of production of the stated film, and to a decrease in the waste of polyamide raw materials. Dyes, pigments or fillers up to 1095 wt. are allowed to be added to the claimed mixture, while the sleeve films are uniformly and intensively colored, preserving the plasticity and barrier characteristics of the polyamide film.

This fact, as well as the advantages of the obtained films in terms of consumer characteristics, will be confirmed by the following examples.

Example Me1

Granule PA b (brand B4, VABE company) and an admixture - the product of transesterification of sunflower oil with glycerin (hydroxyl number 298 - 3305 mg KOH/g) are mixed in a "drunk barrel" type mixer and loaded into the extruder hopper. The mass content of polyamide and impurities in the mixture is 99.95 : 0.0590, respectively. A primary sleeve with a diameter of 26.5 mm and a thickness of 250 - 270 μm is formed from a melt with a temperature of 256 - 2627 C. At a temperature of 60 "C, it is subjected to a biaxial orientation drawing using the pneumatic method with coefficients of longitudinal stretching - 2.6, transverse - 3.0. Then oriented the sleeve is subjected to relaxation annealing at a temperature of 160 - 180"C for 15 seconds, which is accompanied by a longitudinal shrinkage of 1.2 times, cooled to 20"C and wound into a roll. The finished film is glossy, has a thickness of 39 - 41 µm and a diameter of 79 - mm .

During the 48 hours of operation of the line, two cases of film breakage were observed during orientation extraction.

The results of studies of mechanical and barrier characteristics are presented in table Me1.

The mechanical characteristics of sleeve films were determined using a "Hecker" tearing machine at a speed of 110 mm/min. Water vapor permeability was determined at 23"7C and relative humidity 6595 according to OIM 53 122-74, oxygen permeability was determined at 23"C and relative humidity

6595 by SIM 53 380-69.

An example of Me2

The sleeve film is made according to example Me1 using as polyamide PA 66 (brand A4, company "VAB5E"), extrusion was carried out at temperatures of 270 - 2907C, extraction - at 75"C, annealing - at 170 - 19026.

During 48 hours of operation of the line, there were three cases of film breakage during orientation extraction.

An example of MeZ

The sleeve film is manufactured according to the technology described in example 1 from a mixture of polyamides PA 6 and

PA 612 and iron oxide pigment in the form of a 2095th superconcentrate based on PA 6. The content of PA 6, PA 612, pigment, impurities 77.93 : 20.00 : 2.00 : 0.0795 by weight, respectively. Extrusion was carried out at temperatures of 245 - 2607C, extraction - at 72"C, annealing - at 160 - 17070.

During the 48 hours of operation of the line, two cases of film breakage were observed during orientation extraction.

Example Me4

Sleeve film is made according to example Me1 with the addition of a dye - pyrylene red in the form of a 2590th superconcentrate. Mass content of polyamide, dye, admixture - 99.43 : 0.50 : 0.0795, respectively.

During 48 hours of operation of the line, there were three cases of film breakage during orientation extraction.

Example Me5

The sleeve film is made according to the Me2 example with the addition of carbon black in the form of a 3095th superconcentrate and polyethylene glycol with a molecular weight of 10,000 as impurities. The mass content of polyamide, pigment and impurities in the mixture is 98.92:1.00:0.08905.

During the 48 hours of operation of the line, four cases of film breakage during the orientation extraction were observed.

Example Mob

The sleeve film is made according to example Me1 using oleic acid as an impurity and with the addition of a brown iron oxide pigment in the form of a 2095 superconcentrate based on PA 6.

The mass content of polyamide, pigment and impurities in the mixture is 97.94:2.00: 0.06905.

During the 48 hours of operation of the line, one case of film rupture was observed during orientation extraction.

Example Me7

The sleeve film is made according to example Me2 using glycerol as an impurity and with the addition of a brown iron oxide pigment in the form of a 2096th super-concentrate based on PA 6.

The mass content of polyamide, pigment and impurities in the mixture is 97.95:2.00:0.05905.

During the 48 hours of operation of the line, two cases of film breakage were observed during orientation extraction.

Example Med

Sleeve film is made according to the example of MeZ using glycerol triacetate as an impurity.

The mass content of polyamide, pigment and impurities in the mixture is 97.90:2.00:0.10905.

During the 48 hours of operation of the line, four cases of film breakage during the orientation extraction were observed.

Example Me9

The sleeve film is made from a mixture of PA 6, brown iron oxide pigment in the form of a 2095 superconcentrate based on PA 6, PA 6/66 copolymer (C35 brand, BA5E company), PA 6T/6I copolymer (ZEGAE brand "by Eop"), oleic acid and chalk and yakyinvy. of the anti-blocking additive with the mass content of the components, respectively 77.24: 7.87: 3.94: 9.38: 0.07: 1.5095. Modes of extrusion, extraction and annealing as described in example Me1.

During the 48 hours of operation of the line, one case of film rupture was observed during orientation extraction.

Example Me10

Sleeve film is made by co-extrusion of five layers:

PA (5μm)/adhesive (Zμm) / PP (1O0μm) / adhesive (Zμm) / PA (23μm), where PA is a polyamide layer according to example Me1; adhesive - a layer of polyethylene grafted with maleic anhydride (1.5 - 295), (brand "Vupei! -

СХА4Я1Е558" of the company "by Ropg");

PP - a layer of polypropylene brand "Kaplen-35" produced by Moscow Oil Refinery LLC.

The polypropylene layer was extruded at a temperature of 260 - 270"C, adhesive layers - at a temperature of 240 - 26076.

The layers were joined in a special co-extrusion head at a temperature of 26070.

Modes of extrusion of the polyamide layer, extraction and annealing of the sleeve according to the example of Moe1.

During 48 hours of operation of the line, there were three cases of film breakage during orientation extraction.

Example Me11

The sleeve film is made according to the example of Me4 with the addition of ethylenediamine M,M'-stearylamide (brand "Gokhatiy" of the company "Nepke!") as impurities. The mass content of polyamide, pigment and impurities in the mixture is 98.94: 1.00: 0.0695.

During the 48 hours of operation of the line, two cases of film breakage were observed during orientation extraction.

Example Me12

Sleeve film is made according to Meb's example with the addition of polyethylene glycol distearate-400 (Aidgisp) as an impurity. The mass content of polyamide, pigment and impurities in the mixture is 98.92: 1.00: 0.089.

During the 48 hours of operation of the line, four cases of film breakage during the orientation extraction were observed.

Example Me13

The sleeve film is made according to the Mob example with the addition of polyethylene polypropioamide with a molecular weight of 5000 (brand "AdiaoI-5" of the company "Royuteg Spetis! Ippomaig5 So") as impurities.

The mass content of polyamide, pigment and impurities in the mixture is 98.95:1.00:0.05905.

During 48 hours of operation of the line, there were three cases of film breakage during orientation extraction.

Example Me14

Sleeve film is made according to example Me9 using anisic (p-methoxybenzoic) acid as an impurity. The mass content of polyamide, pigment and impurities in the mixture is 97.96: 2.00: 0.0496.

During the 48 hours of operation of the line, two cases of film breakage were observed during orientation extraction.

Example Me15

Sleeve film is made according to example Me10 using y-butyrolactam (brand "2-

RUKO!" of the company "IZR") as impurities in the outer layer of polyamide. The mass content of polyamide, pigment and impurities in the outer layer is 97.91:2.00:0.09905.

During 48 hours of operation of the line, there were three cases of film breakage during orientation extraction.

Example Me16 (comparative)

The sleeve film is made according to the example of Moe1, but without an admixture.

During 2 hours of operation of the line, eleven cases of film breakage were observed during orientation extraction.

Example Me17 (comparative)

The sleeve film was made according to the Me2 example, but without an admixture.

During 2 hours of operation of the line, fifteen cases of film breakage during orientation extraction were observed.

Example Me18 (comparative)

They tried to make a sleeve film according to the examples of MeZ and Me4, but without an admixture.

The primary sleeve cannot be inflated.

Example Me19 (comparative)

Sleeve film is made according to example 8 without admixture.

During the 48 hours of operation of the line, five cases of film breakage were observed during orientation extraction.

Example Me20 (comparative)

The multilayer sleeve film is made according to example Mev8, and the PA layer - as in example Me11.

During the 48 hours of operation of the line, four cases of film breakage during the orientation extraction were observed.

Table rameter 112|z3314|51|61|7|8 9 |t10|11|t12| 1314 | 1516/1791 20 increments of 90195 8080/7695 zv 1000/1085 79 vya| 82/91 102 vv | in | 98 lengthening, o

Breaking load, 195119012051201119811801178|18211401183|20011801197|193|1851200120211601155

"N/m?"

The number of shell breaks per 24 111.51 11.5121|0511 12 10511.511 121151 1 11.5|1132|1180125| 2 hours of work

Claims (4)

1. Thermoplastic polymer mixture for sausage and sausage casings, consisting of one or a mixture of polyamides and a technological admixture, which differs in that as an admixture, a substance compatible with polyamide is used, selected from a number of higher aliphatic ones with a hydrocarbon chain length Сб6-С»о and aromatic carboxylic acids, fully and unsaturated esters of carboxylic acids and polyhydric alcohols, amides of aliphatic acids, polyhydric alcohols, oligomeric polyamides, lactams, polyalkylene oxides with a molecular weight of up to 20,000, their esters, 1 mixtures of the mentioned substances, 1 which has thermal stability up to 3002С, in amount of 0.01-0.595 wt. 2. Thermoplastic polymer mixture according to item I, which differs in that as polyamides, primarily, polyamides 6, 12, 612, 66 or copolymers of polyamides or their mixtures are used. 3. Thermoplastic polymer mixture according to claim 1, which is characterized by the fact that an admixture allowed to come into contact with food products is used. 4. Thermoplastic polymer mixture according to item I, which is characterized by the fact that it contains a dye, pigment or filler up to 1095 wt.