DE1952464B2 - USE OF FIBER REINFORCED POLYVINYL ALCOHOLIC RESIN FILMS FOR PACKAGING FOOD - Google Patents

Description

Fiber-reinforced resin sheets of polyvinyl alcohol (hereinafter referred to as PVA) or partially so as esterified, etherified or acetalized PVA, optionally with the addition of plasticizer have long been known and are used as drive belts and conveyor belts, which can also be prepared by spin technical process (F. Kainer, "Polyvinyl alcohol", 1949, pp. 211/12). PVA and its partially hydrolyzed common esters such as polyvinyl acetate are used, optionally mixed with one another and with the addition of a plasticizer, for gluing and finishing textile threads of various types and for impregnating fabrics and paper.

In the food sector, packaging films made of PVA are used because of their high tear resistance and low oxygen permeability estimated. However, the vapor and smoke permeability turns out to be These films are sometimes considered disadvantageous, which is why they are also made with a vinylidene chloride-vinyl chloride copolymer coated or glued (GB-PS 9 60 203). The hot water solubility of PVA will in boilers for z. B. Rice exploited, which is made of a hot water resistant perforated material and are coated on the inside with PVA (GBPS 9 63 845).

Synthetic casings made from unreinforced PVA have been known for a long time. characterized by sterility and impermeability to bacteria as well as in the case of opaque training by an appearance identical to that of natural casings and peel off smoothly and cleanly and lengthways with the help of an inserted thread let tear open (F. Ka "iner, 1. c, p. 23 7/38)! Disadvantageous What is part of these casings is their high degree of extensibility in the wet state, the extensibility of up to 700 ° C the dry shell. They are therefore despite the good vapor and smoke permeability of PVA films useless for the production of sausages, in which the raw sausage emulsion is cooked and / or smoked in the casing and then packed in slices are sold, and therefore have become economically 6 " not enforced.

Artificial casings made of paper with a hydrophobic polymer with low vapor and smoke permeability is soaked (CH-PS 2 40 984) are also only suitable for wrapping food that has already been cooked and smoked sausages.

The stretchable, moisture-resistant packaging material made from Roecucratcei'uh ^ c. Do tnt is coated with a backing product made of polymerized fatty acids if necessary (DT-PS 9 02 449), because of its elasticity, sieve is suitable for wrapping irregularly shaped meat products such as ham, but not for sausage products that are processed in the sausage casing and sold as cut goods will.

The invention was based on the object of providing a food film, in particular an artificial one Wuisthülle to provide the desired level of water vapor and smoke permeability with the required strength and dimensional accuracy, especially for meat products, which are given to the consumer as cut goods can be used.

The object is achieved according to the invention in that a fiber-reinforced PVA resin film is used, which consists of a fiber insert and a film-forming, optionally crosslinked and / or plasticized PVA resin with a degree of substitution of at least about 20 ⁰ O, based on the OH groups, consists. This film is preferably used in the form of a tube, optionally with a longitudinal seam, and in particular as an artificial sausage casing.

It is characterized by high strength and elasticity when re-moistened from "and here surpasses the sausage casings made of fiber-reinforced regenerated cellulose that have been used for years. This is surprising because unreinforced PVA sausage casings can be found in the moistened state stretch considerably more than unreinforced, clear regenerated cellulose casings. It was therefore not to be expected that by using the same fiber core as with fiber-reinforced regenerated cellulose casings, one like that severe reduction in ductility would be caused.

The PVA resin films to be used according to the invention are generally suitable for wrapping and Packing of food and especially for sausage products such as Bolognese sausages, salami among other things .. which are dispensed in the form of relatively small, appropriately sized packs, whereby each package contains a small predetermined amount of sausage in the form of a given number of slices. When the sausages are mechanically sliced, due to the dimensional accuracy of the film obtain a product of uniform thickness that is easy to pack.

The films to be used according to the invention can be produced in a simple manner by a saturating fibrous web material with an aqueous or organic solution of a PVA resin or impregnated with a melt-extruded film of a PVA resin and the impregnating resin in and then makes it insoluble and hardens on the material. Long-fiber material is preferably used as the fiber material Hemp paper; it is either preformed into a tube and then soaked and post-treated or first soaked and treated and then shaped into a tube. Preferably the Triinkharz is also crosslinked, e.g. B. with formaldehyde. The crosslinking agent becomes the soak resin solution or added to the melt or in a further treatment stage with the impregnated material mi touched. The one saturated with PVA resin Material is already in the form of a tube or al · -! L; ichi.L'S BahnmaUrial \ · .τ: in the latter case

It is cut in the desired manner and the degree of substitution does not, for example, exceed 80%

tu tubular casings processed. The finished- dissolve to varying degrees in numerous

The tubular casings can then be rich in organic solvents including

Once cured or conditioned anhydrous organic solvents. For this purpose

ft-earth. The necessary and optional processes include alcohols such as methanol, ethanol and isopro-

Rating levels are shown schematically in the drawing; Ethers such as monomethyl, monoethyl,

represents and by solid or dashed lines monobutyl and diethyl ether of ethylene glycol and

specified. Diethylene glycol; Ketones such as acetone, methyl ethyl

Monomeric vinyl alcohol is a free compound ketone, diacetone alcohol, methyl isobuiyl ketone and

not known. All attempts to produce it are made up of cyclohexanone; Esters such as ethyl acetate, methyl acetate

th to a rearrangement of the compound to acet and n-butyl acetate; chlorinated compounds such as carbon

aldehyde. In technical terms, PVA resins are therefore used as nitrogen tetrachloride and ethylene dichloride; Coal

Licherweise by hydrolysis of PoK vinyl combines hydrogens such as benzene and toluene; Nitro compound

products that contain aliphatic * or aromatic genes such as nitrobenzene and heterocyclic compounds

Vsnyl ester units included. These include homo-fertilizers such as dioxane and tetrahydrofuran. The loading

polyvinyl esters such as polyvinyl acetate, polyvinyl propio- handle organic solvent also includes

nat, polyvinyl benzoate and carboxylated polyvinyl mixtures of water and organic solvents,

esters, for example those obtained by copolymerization that contain sufficient organic solvent,

a vinyl ester such as vinyl acetate, vinyl propionate to the solubility properties of water alone

and change vinyl benzoate with an ethylenically unsaturated ao, for example if at least 10 vol .- "/»

Carboxylic acid such as acrylic acid, methacrylic acid and the entire solvent is organic.

Maleic acid obtained compounds. The extent of PVA resins with a degree of substitution up to

the hydrolysis is controlled so that products with about 80 ° 0 are still in aqueous-alkaline media

the desired degree of OH group substitution to be soluble. Are preferred here because of the

keep. The PVA, which can be used for the invention, has improved overall properties of the

Resins have a degree of substitution (SG) of minimal foils, the resins with an OH group

at least about 20%, based on the OH group substitution ₃ degrees of at least about 40 °.

salary; Usually the degree of substitution is in the range, on the other hand, with increasing OH group

Range from about 40 to about 99.99 » ₀ , the pen content being the solubility of the resin in general

the latter number depends on the technical production 30 and in particular in hydrophobic liquids.

maximum achievable hydrolysis effective wedge. Resins with a degree of OH group substitution of

Among the resins containing carboxyl groups, for example above 80 ° 0, in the above-described or-

the purposes of the invention to dissolve the resins with a ganic solvent to a lesser extent

Degree of substitution up to about 25 ° 0, preferably in the high. but can advantageously be in aqueous

Range from about 0.1 to 10 ° 0, based on the 35 solvents and the more hydrophilic organic

Carboxyl groups, useful. see solvents such as alcohols and their

Mix and dissolve the PVA resins to be used according to the invention. For resins with an OH group

must be film-bonding resins. i.e., a degree of poly substitution of at least about 98 ° 0 is required

Degree of merization (PG) of at least about 800, especially water, is preferred. Also suitable for

point. Such resins are known to be characterized by these and other resins with a high degree of substitution

Viscosity of at least 4 cP, e.g. B. in the range of mixtures of lower alcohol such as methanol or

labeled about 4 to about 65 cP and above. Ethanol and water with a volume ratio

determined for 4% by weight aqueous solutions with an alcohol to water ratio of at least 0.4: 1.

20 ° C, usually on an Ostwald-iFenske- The selection of the solvent is also made by

Viscometer. These properties are necessary so that 45 affects the heat sensitivity of PVA resins,

the saturating fiber material is sufficiently saturated during the final drying of the impregnated

and the "insolubilized dried film webs should, if possible, use high temperatures

has the desired strength and wet strength. and / or reduced pressures can be avoided.

In general, the solubility of the PVA decreases. Therefore, solvents are preferred that are below

The molecular weight and OH group content are volatile at 50 normal conditions, for example a

from, while the film strength and the melting solvent, its boiling point (at 760 mm Hg)

increase point. For example, resins with a temperature not exceeding 100 ° C are available.

OH group substitution degree over about 95 ° 0 we- To dissolve the alkali-soluble PVA resins

They are soluble and melt at higher temperatures. 3 to 8% sodium hydroxide solution is often used or watered and form films that can also be used without crosslinking 55 solutions of other alkaline substances, such as

are very wet strength. The crosslinking, however, makes KOH, NH ₄ OH and (CHj) ₄ NOH; in all cases

these and other resins are still solid, and less so for the shells with comparable properties

sensitive to water and received accordingly. In general, the alkali concentration fluctuates

the resin in the film is preferably crosslinked. of the aqueous solutions from about 1 to about 20%>.

The solvent for the impregnating resin solution can be 60 The PVA resin is made by evaporating the solvent

any aqueous or organic liquid, preferably at a moderate temperature!

be in which "the" PVA resin used in each case in the range of 100 to 120 ° C or in a Koagu

solves. z. B. with the formation of viscous solvents. the water bath made insoluble. The composition de

Contains 1 to 40% by weight PVA resin. Which del-coagulating baths will vary depending on the one used solvent in the individual case for certain uses 65 resin and solvent and generally includes water

Application purposes are preferred depends primarily on natural and organic solutions of acids or acids

on the PVA resin used. zen such as sulfuric acid, ammonium sulfate and dcre

PY - \ - H: irze with a lower OH group - mixtures or organic liquids (i.e. not

dissolving diluents), in which the particular, practically uniform polymer, resin used is only partially soluble or completely insoluble within a temperature range of 10 ° C and which completely melt coagulation of the resin, is preferred,
works. In general, such aqueous coagulant solutions which are equivalent to self-supporting and nonetheless fibrous solutions, which extrude 1 to 20% railway material-impregnating films, are effective without being thermally bathed Feisäure and Na ₉ SO ₄ or (NH ₄ ) ₂ SO _{4 can be} in an amount, they must be effectively softened from about 5% to saturation (for example 40%>), preferably so far that contained in normal shear. Acid, highly concentrated aqueous salt rate, the melt viscosity of the resin is in the range from about 100 to about 1000 P in the solution, like concentrated ammonium containing sulfuric acid. Active monium sulfate solutions are particularly suitable, the same plasticizers are moisturizing as well as regenerating baths that contain a non-dissolving water-soluble monomeric or polymeric alcohols, thinners such as acetone or benzene, amines or amides such as glycerine, ethylene glycol, the organic solvent. Propylene glycol, polyethylene glycols and polypropylene - Preferably a crosslinking agent 15 glycols with a molecular weight of up to about is provided, which reacts with the deposited PVA at 1000 (triethylene glycol, tripropylene glycol, polyethylene drying and hardening in the heat, where glycol 200, polyethylene glycol, Polyethylene glycol forms a film on and in the fiber web, which is 400, polyethylene glycol 600, etc.), trimethylolpropane, insoluble in water and relatively insoluble in water, sorbitol, formamide, urea; Polyoxyethylene ether is sensitive. Either a soluble ester and an ester containing 2 to 20 moles of ethylene oxide units per wetting agent of the impregnating resin solution and containing a molecule such as polyoxyethylene monophenyl then containing 2 to 7 ethylene oxide units each is activated when the impregnated material is dried, or the molecule impregnated with PVA resin solution or Furfuryl alcohol ether of polyoxyethylene material treated in a further operation with a len containing 3 to 12MoI ethylene oxide units per solution of the crosslinking agent. Usage as a molecule and similar ethoxylated urea derivatives; Possible crosslinking agents for this purpose are aldehydes, such as dimethylolformamide and trimethylolpropane. Special formaldehyde, glutaraldehyde and glyoxal; plasticizers whose boiling ethylol compounds, such as water-soluble formaldehyde point (at 760 mm Hg), are above about 220 ° C. are preferred.
Amine and formaldehyde amide condensation ^ ro- - Generally about 5 to about 40 ° Ό, vorzugsdukte. for example dimethylolurea, trimethylol 30, about 15 to about 30% plasticizer, based on lolmelamine and liquid urea-formaldehyde resins; based on the weight of the P VA resin, added to the diisocyanates, e.g. B. of dimerized linoleic acid or suitable melt viscosities in the above 4,4'-methylene-bis (cyclohexyl isocyanate); Polyepoxide area to achieve. The plasticizer content can be such as butadiene epoxide; Polyamide epichlorohydrin resin; but acid halides such as adipic acid chloride or Seba-35 are also above or below the specified values, provided that the softened cynic acid chloride and polymeric ketenes z. B. the di-resin to self-supporting, practically non-tacky ketene of dimerized linoleic acid. Extrude films if necessary.

or if desired, a catalyst can be used for the warping of the relatively high temperatures involved wetting agents are added, either extrusion are used, the resin is intended the resin solution, in the solution of the crosslinking 40 moderately neither water nor other volatile by means of or separately from both. Contain substances so that there are no errors in the WeH the fibrous web material with a melt surface of the extruded film. It will extruded PVA resin impregnated and coated, therefore care should be taken that the moisture content PVA resins with an OH- are preferably used in the resin mixture fed into the extruder Group degree of substitution of at least about 60% 45 remains below about 0.5% based on the total used. If the resins contain carboxyl groups, then weight.

A maximum degree of substitution becomes with respect to the type of extruder is not limited to the functional carboxyl groups of about 5% and any can be preferred for the melt extrusion, especially about 0.5%. These resins form devices formed by thermoplastics can easily be used to form film-like coatings on which, for example, a fibrous web material which is saturated in the USA can be extruded, the process described in patent specification 29 58 364 penetrate from this and form ultimately converted in and on. In general, the sheet material is continuously produced films that perform the desired work and have flat or tubular resin strength and wet strength. Since with increasing obtain film whose temperature above the Erweigendem molecular weight and OH group content 55 monitoring point of the particular resin (for example, 5 off the solubility and the film strength is increased to 10 ⁰ C above the melting temperature) provide filmbüdende resins having a OH- Groups are made until the fibrous web material in the desired degree of substitution is about 95 · / · when it is impregnated with resin and coated accordingly. If so, foils are softened, which also produce a flat fiber-reinforced foil without first being wetting and which are quite moisture-resistant. Preferably then they are formed into tubular casings, but the melt-extruded resins are also crosslinked with one another as an adhesive for the seam-like. Aqueous or organic solvents that hit the edges are also preferred

Melt up to about 215 ° C. Your degree of polymerisation 65

ranges from about 1000 to about 5000, their hemp paper, depending on the size and size you want

Viscosity in 4Vdger aqueous solution, measured as the weight of the casing to be produced from 20.4 to

stated above is less than about 45 cP. Weighs 27.2 g / m *, other nonwoven webs such as Yoshinci-

3547

Paper, rice paper, paper made from polyvinyl alcohol resin fibers, Hemp, rayon, cotton and nylon as well as woven products such as gauze, marquisette, Filter gauze, organdy and voile in question. In some cases, the web material can with a Surfactants or crosslinking agents can be pretreated to make the PVA resin lighter thoroughly penetrates the material.

The films used according to the invention are in essentially clear, but can also be colored with approved pigments or dyes.

Furthermore, the impregnating resin solution or the melt, in addition to the PVA resin, can contain small amounts up to about 20% by weight of other film-forming resins such as polyvinyl acetate, amylose, etc. added if they are compatible with the PVA resin and the application conditions and the characteristic Advantages with regard to the strength properties of the resin films do not impair.

The foils can also be coated, impregnated or chemically reacted with other monomeric or polymeric substances in order to change the outer and / or inner surface of the PVA resin film of the foil and to adapt it to certain special purposes. In general, the same agents are used for this purpose which are customarily used for cellulose casings in order to impart a certain desired gloss, flexibility, strength, shrinkage, adhesive or non-adhesive properties, wet strength, water permeability, vapor permeability, abrasion, abrasion resistance, fungus resistance and other properties to them. Particularly useful auxiliaries are, in addition to the above-described internal and external lubricants and release agents, for example oils such as silicone oils and polymethylhydrogensiloxane, fats such as acetylated monoglycerides, C ₁₆ to C 4 fatty acid ketendimers, cetyl alcohol or other compounds such as aluminum sulfate. Lactic acid, inositol, methyl cellulose and carboxymethyl cellulose; Shrink coating and adhesive coating agents to be applied to the inside Γ these can be protein-like substances, e.g. B. Mixtures of gelatin and acetylated monoglycerin and gelatin hardened with dialdehydes such as glutaraldehyde and liquid smoke; Furthermore, coating substances to be applied to the outside which reduce the water and steam permeability, such as vinylidene chloride homopolymers and copolymers and polymer mixtures of a paraffin wax and a dimerized ester of an epichlorohydrin-bisphenol reaction product.

The following examples serve to explain the invention in more detail.

example 1

In this example, the production of a fiber casing by impregnating and coating a Fiber paper tube with an aqueous polyvinyl alcohol copolymer solution and subsequent evaporation of the water from the soaked material described.

An aqueous 10% solution of a polyvinyl alcohol-polyvinyl acetate copolymer with an OH group content (SG) of 99.5% and a degree of polymerization (PG) of about 1600 was prepared. The copolymer was dissolved at about 90 to 95 ° C and the viscous solution after cooling with 2.25% glycerol as a plasticizer, 0.4% formaldehyde as a crosslinking agent and 0.22% lactic acid as a catalyst for the Crosslinking agent added.

A web of long-fiber hemp paper, weight 25.5 g / m ² , was pulled off a supply roll, formed into a tube and soaked and coated with the viscous polyvinyl alcohol copolymer solution over a hollow, annular body. The rate of application of the resin solution corresponded to a wall thickness of the coated tube of about 1.27 mm. The tube was then dried with hot air at 120 ° C. and then cured at 140 ° C., a thorough crosslinking of the film and formation of hydrogen bonds between the substituents of the polyvinyl alcohol copolymer molecules taking place. The cured shell was post-treated in a humid atmosphere, whereby it absorbed water and became flexible and easy to handle. The air containing water vapor from the dryer was withdrawn and the water was recovered in a solvent recovery unit.

After drying and restoring the moisture equilibrium (to about 12%) under controlled humidity conditions, the wall thickness of the shell was about 101 to 152 μm. When immersed in water, the shell swelled to a wall thickness of about 152 to 203 μm. The casing had a greater tensile strength and a lower elongation at break than a casing made of fiber-reinforced regenerated cellulose: the tensile strength was 304 to 375 kg / m and the elongation at break was about 15 to 30 ⁰ O, compared to 250-322 kg / m and about 60 to 70 ⁰ Zo with a fiber-reinforced regenerated cellulose casing.

A casing produced as above was first soaked in hot water, then with an emulsion stuffed for Bolognese sausages, sealed at both ends and cooked and smoked as usual. The shell did not crack anywhere, and the vapor and smoke permeability was about the same as with a conventional regenerated cellulose fiber casing. The circumference of the envelope, originally 38 cm, fluctuated less than 4.76 mm in the course of the entire operation.

Example 2

In this example, a saturating fiber material is first treated with an aqueous polyvinyl alcohol copolymer solution impregnated and coated, and the coated web obtained then becomes a seam deformed having hose.

A viscous 10% solution of a polyvinyl alcohol / polyvinyl acetate copolymer with an OH group content SG of 98% and a PG of about 1400, containing 2.25% glycerol, 0.4% formaldehyde and 0.22% vol lactic acid was produced according to Example 1 and applied to a web of long-fiber hemp paper according to Example 1 with the aid of an applicator roller with a doctor blade;

and the impregnated paper web was damp about 1.27 mn thick and was dried under the same conditions net as in Example 1. The dry coated web was about 101 to 152 µm thick; again when wet, their thickness was about 152 to 203 μm. Tuesday The tensile strength in the re-moistened state and the elongation at break were equivalent Paper soaked and coated with regenerated cellulose is superior.

609529 /:

The soaked, dried and hardened paper was conditioned in humid air, in the desired air Way and cut on a conventional closing machine to form a tube with a lengthwise Seam processed. A 10% aqueous solution of a was used as an adhesive for the seam Polyvinyl alcohol-polyvinyl acetate copolymers (OH groups SG about 99.5 per cent), softened with glycerine and formaldehyde and lactic acid in the same Ratio as containing the impregnating resin solution, applied. After gluing the edges, the Sheath heated to dry the adhesive and continuous in itself and in the interconnected Network surfaces. This shell did not burst along the seam in the usual tensile tests on.

Table 1
example

Impregnating resin solution

Polyvinyl

alcohol copolymer

PVA / PVAC
(OH-SG 88 Vo;
PG 1500)

PVA / PVAC
(OH-SG 86%.
PG 1700)

PVA / PVAC
(OH-SG 990 / ,;
PG 1800)

dto.

dto.
dto.

dto.
dto.

Crosslinking agents

0.4% formaldehyde 0.22% lactic acid

dto.

0.4% formaldehyde 0.3% malic acid

l, 25% trimethylolmelamine,

0.2% citric acid

0.5% polyamide epichlorohydrin

1.0% dimethylolurea

0.2% lactic acid 5% glyoxal 0.3% malic acid

5.5% glutaraldehyde 0.2% malic acid

With regard to their strength and their processing properties resembled the shell I ai BeSs ^ l ·

Examples 3 to 10

as in Example 2 with 10% aqueous inner " λ r, ^filmblldende n polyvinyl alcohol copoly-ϊη and m, ^yC , ^{Cnn and Verne} '^" gsmitl: el enthieliea'rbS η ^em ?' ^oak long fiber hemp paper dry; _{in the} ^{soaked pa pics} were poured. ₇₁ ? ^ r'T ^{the seam} closing aralkoholPo! ^{flattened deformed} · ^The polyvinyl and StftvT ^ny wT ^tat ' ^copolymers (PVA / PVAC) h of fo p, h τ? n ^{ht not used} adhesives are in was Ä R ^elle ! ^an 8 ^e 8 ^ebe "· Glycerine was used as a plasticizer in all examples

dto. dto.

Application device
Air knife

Blanket coating machine

3-roller application machine
with running in the same direction
Rollers

3-v roller application machine
with direct order

4-roller application machine
with running in the same direction
Rollers

dto.

Glue for seam

like impregnating resin solution dto.

30% 2,4-toluene diisocyanate in acetone

3O ⁰ Z ₀ cyanoacrylate ester in acetone

30 "Ό Buiadiendiepoxide in acetone

like impregnating resin solution

dto.
dto.

tem polyvinyl alcohol
Sheaths from example 1 and 2

water soluble

^; nigen of

a named,

Example 11
It became the procedure of

id- 'pointed ^

e 'vorana, ^Jltun S ^is S ^ens chaften to "as the ~ ₅₅ HdLen ^ahead g ^e gangenen examples.

Examples 12 to 16

general procedure strength solutions prepared GWB UNH ^P v ^{IyVinylaIkoholhar2en} of Beiweitere organic 10% "" ■ "'the Sen fl crosslinking agent contained moderate poisons flat long-fiber paper webs AAF' ^le were ^{resin-impregnated} webs and molded into tubes in the" ind Application devices, materials for the seams, the PpIjK •. 'Crosslinking agents and the 1 * · ω aen impregnating resin solutions.

Tabel 2 Impregnating resin solution
Polyvinyl alcohol
copolymer Crosslinking agents solvent Application machine Glue for seam example PVA / PVAC
(OH-SG 38%;
PG 1200) 0.4% mold
. aldehvd
0.22% milk
acid Methanol /
water
30:70 Air knife Aqueous PVA / PVAC
solution
(Example 2) 12th PVA / PVAC
(OH-SG 70%;
PG 1500) dto. Methylethyl
ketone Blanket
Coating machine dto. 13th PVA / PVAC
PMA ")
"""' ^r ^ S0%;
PG 1400) 0.4% form
aldehyde,
0.3% malic acid Methyl acetate 3-roll order
machine with the same
meaningful running
Rollers 30% 2,4-toluene
diisocyanate in acetone 14th PVA / PVAC
(OH-SG
99.5%; PG
1000) 1.25% tri-
methylol
melamine,
0.2% lemons
acid Methanol /
water
30:70 3-roller application
machine with
direct order 30% diketender
dimerized linoleum
acid in acetone 15th PVA / PVAC
(OH-SG, 30%;
PG 1800) 0.5% glutar
aldehyde,
0.2% malic acid benzene 4-roller application
machine with the same
meaningful running
Rollers 30% butadiene
di-epoxide in acetone 16

Terpolymer with carboxyl groups - SG approx. 5 ° Ό, obtained by hydrolyzing a polyvinyl acetate / polymethacrylic acid Copolymers.

The finished casings possessed the same strength and processing properties as that Cases of the previous examples.

In these examples again glycerine was used as a plasticizer, which by any of the other plasticizers listed above could be substituted, then envelopes with comparable properties were obtained.

Example 17

to make them samable and easy to use. The next time it was immersed in water, it swelled up " Wall thickness from 152 to 203 µm. Your tensile strength and heat resistance were larger and their elongation at break was smaller than those of more common ones fiber-reinforced regenerated cellulose casings and they lieC As described in example 1, lightly stuff yourself, cook and smoke.

In this example, a paper tube is coated with an aqueous solution of a polyvinyl alcohol copolymer soaked and treated in a coagulating bath.

An aqueous 10% solution of a polyvinyl alcohol resin with an OH group SG of 99.5% and a PG of about 1100 without the addition of a plasticizer and a crosslinking agent was prepared and, as in Example 1, on a tubular web of long fiber hemp paper, grammage 25.5 g / m ^2, is applied, the wet coated tube with wall thickness of about 1.27 mm was guided by two Koagulierbäder, which was an aqueous 5% sulfuric acid solution at 15 ⁰ Zo sodium sulfate. The coagulated tube was pulled through two water baths and thoroughly rinsed, softened in a further bath with an aqueous solution containing 30% glycerol, 1% formaldehyde and 0.2% lactic acid and finally pre-dried, crosslinked and completely dried.

The approximately 101 to 152.4 μm thick shell was with Treated enough moisture to restore their moisture balance and make them bend

Example 18

The procedure was as in Example 17 with the difference that

a) as a solvent for the impregnating resin solution eir methanol-water mixture 30:70 and

b) two acetone coagulating baths were used

The casing obtained, like the casing of the preceding examples, had a higher strength and lower elongation at break than the usual fiber-reinforced regenerated cellulose casings and HeI stuffing, cooking and / or smoking, as described in Example 1, with good results.

Example 19

In this example, an aqueous alkaline * solution of an alkali-soluble, film-forming poly vinyl alcohol resin is used

Example 17 was repeated with the difference that

a) for the production of the 10% impregnating resin solution a polyvinyl alcohol-polyvinyl acetate copolymer: with an OH group content of about 50 ° /

13th

in

(SG 50 ° / o) and dissolved a DP of about 1600 aqueous 4 ° / "sodium hydroxide solution and b) for coagulating a dilute l ⁶ / o aqueous sulfuric acid was used.

The obtained fiber-reinforced polyvinyl alcohol resin shell had the same strength and processing properties as the casings of the previous ones Examples.

Examples 20 to 27

These examples explain further embodiments, in those with aqueous alkaline 10% Polyvinyl alcohol resin solutions was worked.

In all examples, the procedure was generally as in Example 19 and glycerine was used as the plasticizer used.

Table 3

Example of an impregnating resin solution

Polyvinyl alcohol copolymer

NaOH

Crosslinking agents

Crosslinking agent im
Softener bath

PVAPVAC 3 (OH-SG 50 ^e , V.

PG 1600)

PVA / PVAC 8 (OH-SG 40%;

PG 1700)

PVA / PVAC / PA ") 4 (OH-SG 50%;

PG 1300)

PVATVAC / PA ⁶ ) 4 (OH-SG 30 ⁰ Zo:

PG 1800)

PVA / PVAC / PA ⁶ ) 4 (OH-SG 50 »/ ο;

PG 1800)

PVA / PVAC / PMAO 4 (OH-SG 50 Vo;

PG 1300)

PVA / PVAC 4 (OH-SG 40 Vo;

PG 1700)

PVA / PVAC 4 (OH-SG 40 «/ ο;

PG 1700)

^a ) Terpolymer containing 0.5 '/ »acrylate, obtained by hydrolyzing a polyvinyl acetate / polyacrylic acid copolymer;

b) terpolymer containing 8% acrylate, obtained by hydrolyzing a polyvinyl / polyacrylic acid copolymer;

^c ) Terpolymer with a carboxylate content of about 3%, obtained by hydrolyzing a polyvinyl acetate / maleic acid copolymer.

1 ⁰ zo trimethylol

melamine,

0.3 per cent malic acid

1 ⁰ zo trimethylol

melamine,

0.3 per cent malic acid

0.2% methylol melamine

All of the finished casings were, like the casings in the previous examples, with regard to theirs Processing and elongation properties of the common fiber-reinforced regenerated cellulose casings think.

Example 28

In this example, a flat fibrous sheet material was treated with an aqueous alkaline solution Polyvinyl alcohol resin impregnated and coated, the resin regenerated and on the flat sheet material the resin-impregnated and coated fiber web material in a further operation to one Deformed envelope.

A 10% aqueous-alkaline impregnating resin solution according to Example 20 was applied to a flat in a 4-roll application machine with co-rotating rolls Web of long fiber hemp paper according to Example 1 applied. The impregnated and coated paper web was replaced by a series of coagulating, washing and softening tapes of the same composition out as in Example 20 and then the finished paper web in a closing machine to one Deformed tube with a longitudinal seam; An aqueous polyvinyl alcohol resin solution was used as the adhesive for the seam as used in example 2. The casing obtained was identical in its strength and processing properties the covers of the previous examples.

Example 29

This example illustrates the use of melt-extruded polyvinyl alcohol resin in US Pat Manufacture of synthetic casings.

100 parts by weight of dry polyvinyl alcohol-polyvinyl acetate copolymer with an OH group SG of about 71% and a viscosity in 4 ° oiger aqueous solution of about 11 cP / 20 ° C were uniformly with 20 parts by weight of a Polyoxyafkylenphenoläthers mixed, d .r contained an average of five ethylene oxide units per molecule and is known as a polymeric plasticizer for polyvinyl alcohol. The moisture content of the mixture betruc less than 0.1 wt ^0th ''.

A long fiber hemp paper web according to Example 1 was formed into a tube and placed on a Mandrel impregnated and coated with the melt-extruded copolymer (outlet temperature about 175 ° C). The application speed was measured so that the wall thickness of the impregnated and coated Tubing was about 127 to 254 µm. The coated tube was immediately followed cooled with air of about 15 "C, then brought into contact with an aqueous solution, which contained l "o formaldehyde and 0.2 ° ο lactic acid and finally at temperatures up to 140 "C

dries. After this hardening, the casing was conditioned (moisture content 10-15% by weight).

The finished casing had a higher tensile strength and a significantly lower elongation at break as corresponding fiber-reinforced casings made from regenerated cellulose.

The finished casing was soaked in hot water as in Example 1 and then with a Bolognese sausage emulsion stuffed and in usual

ίο way cooked and smoked. The shell burst not on and the vapor and smoke permeability were about the same as conventional fiber-reinforced Regenerated cellulose casings.

Examples 30 to 39

These examples illustrate further embodiments of the manufacture of casings with melt-extruded Polyvinyl alcohol resin.

The general procedure of Example 29 was repeated; the various polyvinyl alcohol copolymers and plasticizers are summarized in Table 4 below.

Tabel 4th OH-SG Viscosity ^a ) Plasticizers Parts by weight / Exit example Art 100 parts temperalur Powder vinyl alcohol copolymer Vo cPs Copolymer formula 99.5 10 20th ⁰ C 99.5 10 according to example 29 10 200 30th 99.5 10 according to example 29 15th 205 31 PVA / PVAC 98.0 12th Polyethylene glycol 15th 200 32 PVA'PVAC 98.0 12th according to example 29 25th 195 33 PVA / PVAC 95 9 Polyethylene glycol 10 195 34 PVA / P VAC 95 9 according to example 29 - 10 200 35 PVA'PVAC according to Example 29 -f 5 190 36 PVA / PVAC 85 11th Triethylene glycol 15th PVA / PVAC 70 12th according to example 29 30th 185 37 95 15th Glycerin 20th 175 38 PVA / PVAC according to example 29 190 39 PVA / PVAC PVA / PVAC /

PMAA ")

») As a 4% aqueous solution at 20 ³ C; ^b ) Terpolymer with a carboxyl group SG of approx. 1 °, Ί acrylic acid copolymers.

produced by hydrolyzing a polyvinyl acetate / polymeth-

The finished casings of Examples 30 to 39 were similar to those of Example 29. The best results have been obtained with copolymers having an OH-SG of at least 95 ¹ Vo.

Example 40

In this example, a flat sheet of fiber paper with melt extruded polyvinyl alcohol copolymer was used coated and then shaped into a tube.

A sample of plasticized polyvinyl alcohol copolymers according to Example 30 was at about 200 ^c C to a flat soft, about 50S exlrudiert to strong film and this film together with ß; a curse train from Langfa: -e - Hanfp.ipie:; -: 'v [\ ^: '. Example ! / 'vNchen? \ v ( ^l i to 30 (α: μ;!; ilen ¹ A;:, ■■■■:; ■ with chrome surfaces hinclurciuiefiihri. The ^ - coated and soaked material was about 254 μm thick. It was 15.24 cm wide cut and led through a bath containing as a crosslinking agent 1 ° / o dimethylolurea and 0.2 ⁰ O lactic acid in aqueous solution. the treated film was then formed into a continuous tube, wherein as an adhesive for the near ' t an aqueous 10% solution of a polyvinyl alcohol-polyvinyl acetate copolymer was used which contained 2% glycerol, 1% formaldehyde and 0.2% lactic acid Ready-to-use and cross-linked at a temperature of up to 140 C.

The received! Hill ·; nlatr.te not along the seam, lü! '. «F ;;: i ^ io 'Ie;";ül'lxhjn subject to ver-iidien ·.'.;: Rde:; Their properties were similar to those of the garbage from the previous examples.

19 52 4154

17 18

dieiidiepoxide and the diketene of dimerized Examples 41 to 43 Linoleic acid repeated as an adhesive for the seam.

The received casings corresponded in their strength

The procedure according to Example 42 was carried out with a keii: s and elongation properties of the casings 30% acetone solution from toluene diisocyanate, buta- 5 Example 40.

1 sheet of drawings

Claims (1)

Claim: Use of fiber-reinforced polyvinyl alcohol resin films consisting of a fiber insert and a film-forming, optionally crosslinked and / or plasticized polyvinyl alcohol resin with a degree of substitution of at least about 20 ° / e, based on the OH groups, Preferably in the form of a hose with ίο possibly a longitudinal seam for packing food, especially as artificial sausage casings.