DE1769414A1 - Process for the production of foam bodies for packaging purposes - Google Patents

Description

FARBENFABRIKENBAYERAG "69 * 1 * LEVERKUSEN-Bayerwerk 2 O. Μθί 1968 Patent department

Pr / Kr

Process for the manufacture of foam bodies for packaging purposes

The invention relates to a method for producing Foam bodies for packaging purposes, the Schautnkcrper made of copolymers of ethylene, vinyl chloride and others Comonomers exist.

It is known to make packaging strands made of foams to produce that foaming a foamable plastic in molds. Go is obtained z. B. Foam bodies for packaging purposes, by placing blowing agent-containing and pre-blown polystyrene beads in a mold and with the help foams by steam to form moldings.

Foam moldings can also be produced by foaming polydol / polyisocyanate / water mixtures in molds. The disadvantage of this method is that relatively expensive molds and foaming devices are required.

The invention relates to a process for the production of Le A 11 356 - 1 -

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shaped showo ^ crpern as packaging material, characterized in that eat the shape of the object to be packaged in a foam body with a heated punching tool practically flat surface, the foam body made of copolyroerisates based on ethylene, vinyl chloride and optionally other monomers, impresses.

Foam bodies made from copolymers of

60-92 wt .- # vinyl chloride,

10-8 wt .- ^ ethylene or 30-8 wt .- # ethylene and propylene, wherein the propylene content of 0.1 - 15 wt .- # may be, and 0-10 wt .- # of a crosslinking monomer

with more than one copolymerizable double bond

suitable.

Examples of monomers which contain more than one copolymerizable double bond are: polyallyl compounds such as triallyl isocyanurate, diallyl isocyanurate, trimethylolpropane triallyl ether, Trimethylolpropane diallyl ether, triallyl phosphate, Polyvinyl compounds such as di- or trivinylbenzenes or the corresponding toluenes or vinyl esters of polybasic carboxylic acids such as divinyl adipate, divinyl maleate, divinyl phthalate, vinyl or

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or allyl esters of unsaturated carboxylic acids such as. B. Acrylsäureallyleeter, Methacrylsäureallylester, Itaccr> säurediallylester, fumaric acid diallyl ester, acrylic or methacrylic ester of polyfunctional alcohols such. B. glycol diacrylate, glycol dimethacrylate, methylnorbornenyl acrylic ester, acrylic and methacrylic esters of hydroxyalkyl (eth) acrylic acid esters.

Preferably in the (^ polymers as monomers having more than one copolymerizable double bond contained in copolymerized form: triallyl isocyanurate, triallyl phosphate, Glykoldi- M oethacrylat, divinyl adipate, Trimethylolpropantrimethacrylsäureester, glycol diacrylate, allyl acrylate, Hydroxymethylnorborneny acrylate!.

The crosslinking monomers can be copolymerized Form in amounts of 0-10% ~ 6, preferably 0.01-5% by weight, be contained in the copolymer!

The production of the foam bodies such as foam sheets λ from ethylene, vinyl chloride and, if appropriate, further monomers can be carried out according to the processes of the German patent applications

F 49 964 IVc / 39b (patent), F 50 864 IVc / 39b (patent

), F 53 160 IVc / 39b (patent) and the German patent application (patent ..; Le A

.11 499) or based on the procedures of this

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Registrations.

17694H

The method according to the invention is carried out in such a way that a punching tool is in the shape of the object to be packaged heated and impressed in the foam body. It is particularly advantageous to use the object to be packaged itself as a punching tool to use. The punching tool or the object to be packaged is heated to temperatures above the begin nenden softening point of the foam. Temperatures of 50 - 140 ° C are suitable for this. At these temperatures A slight pressure is enough to impress the shape of the object to be packaged into the foam body. In many cases, the weight of the item to be packaged is sufficient.

If you want to pack an object from two sides, it is useful to place the heated object between two Foam sheets and briefly presses with pressures below 0.1 atm. The pressing time depends on the temperature the punching tool or the item to be packaged. At higher temperatures, it can be selected to be short will.

The temperature to be selected for the deformation of the foam depends on the softening point of the copolymer. Have copolymers with a high ethylene content (over 15 percent by weight)

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a relatively low softening range. They can be deformed at temperatures of 50 - 60 ° C. Copolymers with a content of less than 15 wt .- ^ ethylene and optionally crosslinking comonomers soften in the range of 50-90 C. Correspondingly higher temperatures of 60 - HO ⁰ C. are therefore required for embossing.

It is most advantageous to choose copolymers with a softening point from 40 - 60 ° C, d. H. Copolymers consisting of approx. 15 wt .- # vinyl chloride and 85 wt .- # ethylene. In In these cases, the item to be packaged or the punching tool only needs to be brought to temperatures of approx. 60 - approx. To be heated to 110 ° C.

It was surprising that the foams of the specified Compositions are so outstandingly suitable for the process according to the invention, especially since, for example, foam made from polyisocyanates can no longer be thermally deformed afterwards. Due to their property, polystyrene foams are also to soften and melt within a narrow temperature range is not suitable for the process according to the invention. They are also too hard as packaging materials and their softening temperatures are too high. In contrast, own the foams according to the invention based on ethylene, vinyl chloride

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and, if necessary, other monomers a surprisingly large one. Softening range of approx. 20 - 50 temperature units ( ⁰ C). In addition, these foams are elastic and can be compressed up to 60 % of their original volume without the foam structure collapsing. You therefore have a large tolerance when heating the object to be packaged. Due to the elasticity of the foam, there is no risk of breakage

for shock-sensitive objects to be packed.

No expensive molds are required to carry out the method according to the invention. This is a real advantage in the packaging of small series of articles in which a preparation of foam molding would be too costly.

The method according to the invention is particularly advantageous for packaging glass appliances. Since glass appliances are mostly made by hand, their dimensions vary. According to the method according to the invention, the right packaging foam body can easily be produced for every object. This rational packaging way, preferably for the packaging of laboratory glassware, bottles, households glasses, glass electrical devices, such as tubes, incandescent lamps etc. may be used. The elastic foam offers these fragile objects excellent protection. Since the foam in the

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mentioned temperature ranges does not yet melt, but only shrinks, the object does not stick on the foam body.

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example 1

On a 6 cm thick foam sheet, consisting of a Copolymer of 15 wt .- $ ethylene and 85 wt .- / 6 vinyl chloride and with a density of 16 g / l, an Anschütz-Thiele advance made of Jena glass, previously heated to 60 ° C, is placed and made by hand briefly pressed into the fabric. The glass apparatus can be removed from this half-shell packaging form without that only traces of the polymer stick to the glass wall. The counter shell is made in the same way.

Example 2

The glass apparatus as in Example 1 is heated to 80 ° C. and placed between two 5 cm thick foam sheets consisting of 15% by weight of ethylene and 85% by weight of vinyl chloride. The plates are pressed for 10 seconds in a 0.1 atmospheric press. The shape of the glass apparatus is then embossed into both foam sheets.

Example ^

A bubble counter made of Jena glass is heated to 120 ° C in a drying cabinet and, as in Example 2, between two 5 cm thick foam sheets, consisting of a copolymer of 11.8 wt. - ^ ethylene, 0.1 wt. # Triallyl isocyanurate and 88, 1

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Wt .- # vinyl chloride with a density of 20 g / l, with 0.1 atm pressed. The shape of the apparatus is indented into both foam sheets. The apparatus is solidified by the foam enclosed. The object packed in this way can easily be thrown from a height of 2 m onto a stone floor without the glass apparatus breaks.

Example 4

A positive impression of a porcelain plate made of plaster of paris or steel is heated to 120 ° C and with it when printing 0.3 atü the negative form of the porcelain plate in a 3 cm thick foam sheet, consisting of 13 wt .- ^ ethylene, 1 wt% divinyl adipate and 86 wt% vinyl chloride, within Embossed for 10 seconds. This embossing process can be carried out either by hand or with the help of a machine.

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Claims (3)

Claims c ru- _k 1 .J) Process for the production of shaped foam bodies as packaging material, characterized in that the shape of the object to be packaged is converted into a foam body with a practically flat surface with a heated punching tool, the foam body being made from copolymers based on ethylene, vinyl chloride and optionally further monomers exists, imprints. 2.) The method according to claim 1, characterized in that the foam body from Copolynierisaten of 60-92 wt .- # vinyl chloride and 30-8 % by weight of ethylene or 30-8 % by weight of ethylene and propylene, the propylene content being 0.1-15% by weight and 0-10 wt. 5 * from a monomer with more than one copolymerizable double bond exist. 3.) Method according to claim 1 and 2, characterized in that the punching tool is the object to be packaged . Λ 11 Ί56 - 9 - 109827/1661