DE1183412B - Covering cellulose hydrate films with vinylidene chloride copolymers using an anchoring agent - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Boarding school Class: B44d

German class: 75 c - 5/06

Number: 1183 412

File number: B 350Q6 VI b / 75 e

Filing date: March 23, 1955

Opening day: December 10, 1964

The invention relates to a moisture-proof, sheet-shaped packaging material comprising a cover comprises a vinylidene chloride copolymer.

It is a not yet fully resolved problem in the manufacture of moisture proof, arch shaped Packaging material consisting of a base film made of regenerated cellulose, which is provided with a coating of a vinylidene chloride copolymer, a really strong one To cause the coating to adhere to the base film. Surface coatings made of vinylidene chloride copolymers, such as B. vinylidene chloride-acrylonitrile copolymers, adhere relatively poorly to base films made of regenerated cellulose and the like, and the usual measures for attaching the known moisture-proof surface coatings of the base film do not give satisfactory results when applied to these copolymers will. However, if the surface coating does not adhere well to the base film is, of course, the desired good properties with respect to moisture resistance, heat sealability, flexibility and strength, which are inherent in the copolymers mentioned are not fully exploited.

The invention provides a moisture-proof, sheet-shaped packaging material which is a grand film made of regenerated cellulose and a moisture-proof making surface coating of a vinylidene chloride copolymer comprising even if the moisture-proof packaging material is used for long periods Time in direct contact with water or moisture is held. :

It is already known that polymerized ethyleneimines increase the adhesive strength of hydrophobic layers on films made of regenerated cellulose 'The Polyäthylenimine can be applied to the cellulose hydrate films from dilute aqueous solution e.g. from a: 1 "/ own aqueous solution or from a dilute solution in an organic solvent, e.g. 0.5 "/ intrinsically alcoholic Solution. On this cellulose film, various types of waterproof varnishes, including polymerized vinyl compounds such as polyvinyl chloride and the like.

A method for producing films and in particular films made of regenerated cellulose, which are coated with lacquer layers, is also known, which is characterized in that the films are coated with cellulose hydrate films before the lacquer layer is applied
Vinylidene chloride copolymers under ~
Use of an anchoring means

Applicant:

British Cellophane Limited,

Bridgwater, Somerset (UK)

Representative:,

Dipl.-Chem. Dr. W. Koch, “■ ■

Hamburg-Großfiottbek,

and Dr.-Ing. R. Glawe ,,

Munich 22, Liebherrstr. 20, patent attorneys

Named as inventor:
William Berry j _: ,, ....,.,

Edward George Sanderson, -, ".-. ■

Bridgwater, Soiteset (UK) -

Claimed priority: '* ₍ ''''".
Great Britain, ybpx'26, röai "J954 (15 601).

a polyalkylene imine or with a polyalkylene imine mixture. The polyalkylene imine can be added to the mother liquor, that is, to the solution of the raw materials. for the film or the softener bath which is provided in the process of making the film an imine content of 0.1% or less is sufficient for a good effect: ■ · ■■ '· ·· -. ■■■■■ r ",:,; ·: -' - ■ ". . ' -. ■. · ·. · -

The polyalkylenimines, however, prove to be unfavorable as anchoring agents made from regenerated cellulose in those cases in which the coating layer to be anchored was not made of a plasticized plastic, for example not of a wax-containing cellulose. In these Färilen preferred manuals anchoring means katibniscbe - urea-formaldehyde-ilarze. These have incidentally J against waehshaltigen Nitröeelluloseschichten more arid uöd soft- 'Kunstetoffschdchten made proved to be the best anchoring means · ταΜ ■ consequently in the art · than Vetankerungsmdttel · for paint layers on sheets of reclaimed Celialose ^r more ■ with higher imports. '■

As has now been found, when used as anchoring means for polymers Vinyl compounds on cellulose hydrate films known polyalkyleneimines, preferably polyethyleneimine, a surprisingly high anchorage strength as an anchoring agent for vinylidene chloride copolymers. The anchoring achieved is much stronger than when using urea-formaldehyde resins as adhesive. These

Polyalkyleneimines are relatively low polymer and have a viscosity of about 100 poise in 20% aqueous solution at 20 ° C. The preferred Polyalkyleneimine is polyethyleneimine.

When using the polyethyleneimines according to the invention, the treatment is preferred the base film with the polyalkyleneimine before the surface coating is applied

wherein the excess plasticizer is removed in the manner indicated above, and it can then the polyalkyleneimine in aqueous solution, e.g. B. by means of rollers or spray devices, applied who-5 the. However, the invention also relates to the production of films which do not contain any plasticizer contain.

But you can also take place before the application of the surface coating treatment of the

However, the outstanding effect is noticeable in the base film with the polyalkyleneimine as a special feature value only against shifts that perform from process step. It can, for. B. the Vinylidene chloride copolymers exist. ready-dried base film with a thin covering

Formulated from a liquid composition suitable for use in accordance with the invention Polyalkylenimines can be carried out in a known manner, consisting of one in an organic Polymerization of the appropriate 15 solvents, such as. B. Ethylene alcohol, dissolved Alkylenimines are produced. The preferred polyalkyleneimine consists, whereupon then the

Solvent from the surface of the film Heat evaporation can be removed. The concentration of polyethyleneimine 20 in the liquid composition can be within in the range from 0.01 to 1.0 percent by weight, with a range from 0.05 to 0.10 percent by weight is preferred.

The moisture-proofing surface

carried out during the manufacture of the film. In addition, vinylidene chloride copolymers can be added at can z. B. water-soluble polyalkyleneimine which forms the base film from a solution in an organic viscose, from which the film will later be applied in a known manner to see solvents. The educated will be added. Preference is given to solubility in organic solvents however, the film after the actual vinylidene chloride copolymers have been formed and the film has been lightened, and while this is still in gel formation on base films made of regenerated cellulose is in the form of polyalkyleneimine from solutions in organic solvents are at acts. The term "gel state" is known and used, for example, in the British patent * Used in the description for the swollen font 622 481 described. The Preferred Vinyli «· water-containing state that the film originally made of the chloride copolymers for application if it is coagulated during manufacture 35 Solutions in organic solvents are those and before it is dried, d. H. that is to say to all of those produced by polymerization in a known manner

Mixtures of 75 to 92 percent by weight of monomeric vinylidene chloride and 25 to 8 percent by weight percent monomeric acrylonitrile and or odes

be obtained continuously by an aqueous 4 ° methyl methacrylate before drying, the ge <riges bath being passed, which should give the polyalkyleneimine total proportions 100%. Contains suitable orga · ^ in the desired concentration. The preferred concentration of polyethyleneimine in the
aqueous bath is within the range of
0.01 to 1.0 percent by weight, calculated on the bath 45
weight, and especially in the area between
0.05 and 0.1 percent by weight. The pH of the bath
is not critical and can range from 4 to 11
lying, with a pH of 8 to achieve the
best results is preferred. The bath temperatures of vinylidene chloride mixed polymers and did door can be between 15 and 80 ° C, an application of such an aqueous copolymer * temperature of 60 ° C being particularly suitable. If dispersions on base films made from regenerated cellulose, the aqueous bath also contains a water-soluble soft loose material, this is described, for example, in British patent specification Macher for the film made from regenerated cellulose, 655,732. Preferred vinylidene chloride. B. glycerol, then the treatment with mixed polymers for the application of colloidal polyalkyleneimine and the impregnation with dispersions in aqueous media are those which take place at the same time as the plasticizer. Before the obtained by polymerization in aqueous film enters the drying device, a dispersion of a mixture of (a) 75 to 98 Ge excess of liquid can be removed by means of pressure rollers by weight percent monomeric vinylidene chloride and (b) or a doctor blade. The amount of poly- 60 25 to 2 percent by weight of one of the following veralkylenimine can be adjusted by adjusting the concentration of bonds that hold a substituted vinyl group ent- '- tration on polyalkylenimine in the aqueous bath, or a mixture of two or more of the and or or by changing the amount of like compounds, such as. B. monomeric acrylic excess liquid can be controlled. If onitrile, monomeric methyl methacrylate, methyl is desired, the polyalkyleneimine should be applied separately from acrylate and ethyl acrylate, the proportions being applied together with the plasticizer, the gel-like quantity can be 100%. The mixture from which the film or the gel-like film is first treated with an aqueous merization of the vinylidene chloride copolymers obtained by means of a polymeric solution of the plasticizer can also be 0.25 to

Cases for the state in which the film has swollen before it is finally dried. Here can the gel-like film made of regenerated cellulose briefly

Niche solvents are methyl ethyl ketone and a "mixture of equal parts by weight of methyl ethyl ketone and toluene.

The moisturizing surface over-f A mixture of vinylidene chloride copolymers can also be applied to the base film using a colloidal disper-f sion can be applied in an aqueous medium .; The production of aqueous colloidal dispersion,

Contain 2.5 percent by weight of itaconic acid or itaconic anhydride, calculated on the total weight of the copolymerizable constituents present.

The thickness of the surface moisturizing coating on each side of the base film is typically about 0.0013 mm. The surface moisturizing coating adheres firmly to the base film when the coated film in direct contact with water at room temperature for a considerable period of time is brought or when in direct contact with boiling water for at least 10 minutes is brought.

The regenerated cellulose film can be made from viscose or copper ammonium cellulose in a known manner or from another aqueous dispersion of cellulose.

The following examples illustrate particular embodiments of the method according to the Invention.

The proportions given in the description are to be understood as proportions by weight.

Example I.

A moisture-proof sheet-like packaging material is made in the following way:

A purified gel-like film of regenerated cellulose with a thickness of 0.023 mm, which is known in Way made of viscose is passed through an aqueous bath (pH = 8), the one Has a temperature of 60 ° C and has the following composition:

Glycerin 5.0 parts

Polyethyleneimine 0.05 parts

Water 94.95 parts

After leaving the bath, the film is passed between pressure rollers to remove the excess Remove liquid from the film surface. Subsequently, the film is then through it dried so that it is passed over drying rollers at a temperature of 100 ° C. The dried one The film is coated on both sides in a known manner with a 40% strength aqueous dispersion of vinylidene chloride copolymers coated, the polymerisation of a mixture of 94% monomeric vinylidene chloride and 6% monomeric! Methyl methacrylate is obtained in aqueous dispersion. Thereupon the on its surface with coated film dried at 100 ° C.

The result is a sheet-shaped packaging material made from a base film of regenerated Cellulose and a moisture-proofing surface coating made from a vinylidene chloride copolymer consists. The surface coating, which has a thickness of 0.0013 mm, will also then still held on the base film if the packaging material was uninterrupted for 15 minutes is immersed in boiling water. The packaging material is particularly suitable for Packaging that is in direct contact with products that contain large amounts of water for a long time or contain moisture, such as B. Ice cream, fresh or frozen vegetables, frozen meat, Cheese and butter.

Example II

A moisture-proof, sheet-shaped packaging material was made in the following manner:

A purified gel-like film of regenerated cellulose with a thickness of 0.023 mm, which is known in Way made of viscose is passed through an aqueous bath (pH = 8) that has a temperature of 60 ° C and has the following composition:

Ethylene glycol 5.0 parts

Polyethyleneimine 0.1 part

Water 94.9 parts

After leaving the bath, the film is passed between pressure rollers and in the in the manner described in Example I dried. The dried film is covered on both sides with a Solution of 17.5% vinylidene chloride "MiscEpolymeren, which in a solvent mixture of 50%

ao methyl ethyl ketone and 50% toluene is dissolved, coated, The vinylidene chloride copolymer is made by polymerizing a mixture of 90% monomeric vinylidene chloride and 10 Vo monomeric acrylonitrile in aqueous dispersion and separation, Washing and drying of the copolymer obtained. The coating bath is at a temperature of 55 ° C and the coated film is dried at 100 ° C. The thickness of the coating each side of the film is 0.0013 mm.

The product was a sheet-shaped packaging material made from a base film of regenerated Cellulose and a moisture-proofing surface coating made of vinylidene chloride copolymers. The surface coating will still be held in place by the base film even if the Packaging material is immersed in boiling water continuously for 60 minutes.

Example III

A moisture-proof, sheet-like packaging material is made in the following way:

A completely dried FUm made from regenerated

Cellulose with a thickness of 0.023 mm, which has been plasticized by the incorporation of 15% glycerine, calculated on the weight of the oven-dry film, is passed through a bath of a 1% alcoholic solution of polyethyleneimine. After the excess solution has been removed from the film surface by a doctor blade, the alcoholic solvent is removed from the film surface by evaporation with the action of heat. The dried film is coated on both sides with a 15% solution of vinylidene chloride copolymers in a solvent mixture of 50% toluene. The Vraylidene chloride mixed polymer is obtained by polymerizing a mixture of 80% monomeric vinylidene chloride and 20% monomeric methyl acrylate. The coated film is dried at 100 C ^p. The surface coating of the mixed polymer, which has a thickness of 0.0013 mm on both sides of the film, is still held in place by the base film even if it is immersed in boiling water for 20 minutes without interruption.

Example IV

A moisture-proof, sheet-like packaging material is made in the following way:

7 8

A completely dried film of regenerated free acid was sufficient, the possible cellulose with a thickness of 0.023 mm, which had been formed by way of a slight decomposition of the Misck incorporation of 10% glycerine and 5% urea, polymer, in the solution pre-calculated on the weight of oven dry film to has been as a condensation catalyst softened to the hands, of the urea formaldehyde resin in a 0.3 ^fl / o alcoholic solution of poly heat during drying are used to search through a bath of 5 hardnesses can, äthylenimin led. After removing the over- The surface coating survived the action of the liquid from the film surface by means of the boiling water when immersed! The alcoholic solvent is applied with a doctor blade for 30 minutes without the surface coating on the film surface becoming detached from the base film by evaporation under heat; the surface coating at a temperature between 80 and peeled off after immersion in a boiling temperature of 90 ° C. The dried film is on both water for 35 minutes. Pages with a 40% aqueous colloidal disper- The use of Polyalkyleniminea for the addition of vinylidene chloride copolymers over-strengthening of moisture-proofing coatings, which are made by polymerizing in aqueous dispersions of vinylidene chloride mixed polysion of a mixture of 80% vinylidene monomer It has a number of advantages, based on base films made from regenerated cellulose chloride and 20% monomeric acrylic chloride. So it becomes as has been held above. The film, which is provided with a coating on its surface through the use of polyalkyleneimines, dries better at 100 ° C. as an anchoring agent. The mixed polymer surface coating, consisting of 20 moisture proofing surfaces, has a thickness of 0.0013 mm on both sides of the vinylidene chloride mixed polymer line a '? has on film, still adheres firmly to the base film made of regenerated cellulose achieved as a base film when the film is immersed in boiling water for 10 minutes without interruption through the use of other anchoring agents, such as. Formaldehyde urea resins or mold. 25 aldehyde melamine resins. In addition to> · · 1 γ, this result is quite surprising because the. Superiority of the • ■ "polyalkylenimines over these other anchoring

A moisture-proof, arch-shaped packaging material with a view to anchoring moist-

Kungsmaterial is produced in the following way: Keits-making surface coatings from

A cleaned gel-like film made of regenerated 3 ° vinylidene chloride copolymers on base fuels

Cellulose with a thickness of 0.023 mm, which is used in regenerated cellulose in cases where others

has been made from viscose in a known way, moisture-proofing surface coatings,

is not used in an aqueous bath with a soft, e.g. nitrocellulose

macher and an anchoring agent at pH = 8 is detectable. The anchorage obtained is at

led, which has a temperature of 60 ° C 35 of the use of polyalkylenimines in such

and has the following composition: cases not better and in general even

Polyethylene glycol (average worse than that when using

Molecular weight 300) 5 parts, for example, cationic formaldehyde urea

Polyethyleneimine 0.05 parts ^har f * ³ ^ anchoring agent is achieved

Water 94 95 parts ⁴ ° Other notable benefits are the following:

Ge after leaving the ^Ba ^ ^s _f. ^ F ^{ird d. F "m} 1. There are only very small amounts ta between squeeze rollers durchgeführt.und ^ m ^ of polyalkyleneimines, for example, as described to reduce ta same manner in Example I. - _{Q Q} J _G ^ _{chtsproi enU} calculated on the dried The dried fihn is on both ₄₅ weight of the aqueous treatment bath, required, S ^ i T ^er i ¹⁷ ' ^{5 mg of lot} ™ ^g , ^Vmyl i ^d _n T; by one effective anchoring of the ob-

S? W- ^ ^1S , ^P L ° / ^mer * "■ ^e £ foT? T ^S ? - · Ι ° ^η 50/0 surface coating on the base film to Ϊ-

Methyl ethyl ketone and 50%. Toluene coated. _{rich Oi} J _{s result} ^ _{under savings}

The vinylidene chloride mixed _{polymer is made possible by aQ material and UQter} retention of the * -

Polymerisation.a mixture of 90% mono- ₅₀ desired flexibility of the film. '

merem vinylidene chloride and 10% monomeric _{2 The basic film made of} regenerated cellulose fat

Obtain acrylonitrile. The coating _{bath is treated on the basis of the} ρφ.

Maintained a temperature of 55 ° C and the over-alkylenimines and odorless after drying.

The drawn film is dried at 100 ° C. The fat " _ * . . "..,", ..., ⁶ . . . .

of the coating on both sides of the foot is ₅₅ ³ " ψ , ^{no hard} " ^or drying agent is required.

0.0013 mm. The surface coating will also then. JP ', ",. . ,,,

still captured by the basic film when the verse ⁴ " ^Das _f ^en _t ^W ?! ^Ch ? ^a i ^e i; -Tt ^ J

packaging material without interruption 60 minutes ^{mi "el} folding bath is stable

is immersed in boiling water for a long time. wide pH range, which extends from pH = 4 to

For comparison, in Example III loading _6o was - r ~ ¹ ^ ^"r f ^C. -, - _{t A}

wrote procedures repeatedly, but the ⁵ ·? «Polyalkylenimineipolymermeren.unter dm

the plasticizer and the anchoring agent ent- conditions of the present method mciit

holding bath had the following composition: ^ Jn ** ™ ψ ** ^ ' ^? ^ ^ f * ⁰ ** "

f, ,,,,,. ⁶ Unrestricted base vane before covering

Polyethylene glycol (average _{size will be}

Molecular weight 300) 5 parts 65 ^{5 5}

Cationic formaldehyde-urea- With the expression "fixing" or "anchoring"

Resin 0.2 part is fixing in the present specification

Water 94.8 parts of the surface coating on the base film in the

Manner means that the product obtained is the harmful effects of water or moisture survives. In other words, the surface moisturizing coating should be removed from the water-sensitive base film does not peel off, throw or peel off, if that Product in direct contact with boiling water for at least 10 minutes or at least Is brought into contact with water at 20 ° C for 7 days.

10

Claims (1)

Claim: Use of the as an anchoring agent for coatings made of polymeric vinyl compounds Cellulose hydrate foils' known polyalkylenimines, preferably of polyethylenimine, as Anchoring agent for coatings made from vinylidene chloride copolymers. Considered publications:
German patent specification No. 753 191.