EP0107576B1 - Polyvinyl alcohol film with retarded water-solubility, process for its preparation and its use in burying dead bodies - Google Patents

Abstract

1. Method for the production of a device for burying dead bodies, comprising a polyvinyl alcohol film with retarded aqueous dissolution, obtained from a saponified polyvinyl alcohol resin, characterized in that a film is utilized such as : - its thickness is comprised between 30 and 100 mu m ; - the basic polyvinyl alcohol resin contains a proportion by weight of residual unsaponified vinyl acetate which is comprised between 0,2 and 0,7% ; - said film comprises in its body a plasticizer and an anti-blocking agent ; and - before removal of water useful for aqueous dissolution, the composition by weight of said film is approximately as follows : - polyvinyl alcohol resin : from 45 to 60% - plasticizer : from 5 to 20% - anti-blocking agent : from 0,05 to 0,2% - water : amount sufficient for aqueous dissolution of the resin.

Description

The present invention relates to a method for producing devices for burying corpses based on a film of polyvinyl alcohol with delayed aqueous dissolution, as well as such a device obtained by implementing the method.

It is known that polyvinyl alcohol films are obtained from polyvinyl alcohol resin granules, themselves obtained by polymerization, aqueous dissolution, and then saponification of the vinyl acetate produced by the action of acetic acid on acetylene. These granules are then dissolved in water, heated and added with various components and the aqueous mixture obtained is shaped into a film, for example by calendering or extrusion blow molding.

In general, polyvinyl alcohol films are soluble in water and it is known, by means of thermal or chemical treatments for example, to adjust the solubility of a polyvinyl alcohol film as a function of the temperature. water in which said film is immersed.

Furthermore, from document DE-A-3,014,616, a device for burial of corpses based on polyvinyl alcohol is already known. However, in this known device, the quality of the polyvinyl alcohol is not specified and, moreover, it is necessary to provide an internal coating.

The object of the present invention is to provide a device for burying corpses based on a film of polyvinyl alcohol, the aqueous dissolution of which, instead of being practically instantaneous as in known films, is delayed over time a few months; the device according to the invention can then be produced, among other forms, in that of shrouds, mortuary covers or coffin bowls.

We know that, today, the dead are only buried several days after their death and that they are not put into beer until the day of the burial. As a result, the bodies are exposed, generally on a bed, several days before being buried, and that, especially in hot weather, the decomposition of said bodies is sufficiently advanced before being put into beer to cause the emission of odors. foul-smelling and to raise hygiene issues.

• - masquer les imperfections du bois de cercueil,
• - et surtout réaliser une cuvette étanche pour pallier les effets de la désagrégation des corps dans le temps.

Furthermore, it is known that the coffins have an inner padding constituted by a plastic film of white polyvinyl chloride. This 100 µm plastic sheet has a dual role:

• - hide imperfections in the coffin wood,
• - and above all to make a watertight bowl to mitigate the effects of the disintegration of the bodies over time.

• - le chlorure de polyvinyle n'est absolument pas biodégradable et se retrouve toujours, même après une période de mise en terre très longue.
• - quand l'on veut procéder à des réductions de corps ou des exhumations ce qui est assez courant, les personnels qui effectuent cette opération se trouvent toujours en présence de ces cuvettes qui sont restées étanches et qui par là même contiennent tous les éléments de décomposition avec le grand nombre d'inconvénients majeurs que cela entraîne.

The realization of this waterproof polyvinyl chloride bowl poses the following problems:

• - polyvinyl chloride is absolutely not biodegradable and is always found, even after a very long planting period.
• - when we want to carry out body reductions or exhumations which is quite common, the personnel who carry out this operation are always in the presence of these basins which have remained watertight and which thereby contain all the elements of decomposition with the large number of major drawbacks that this entails.

It is therefore interesting to make a bowl which, after a few months (5 to 6 approximately), under the effect of the decomposition of the corpse, disintegrates gradually and so that the results of the decomposition are eliminated in the ground .

Thus during exhumation operations or reduction of bodies, the personnel is only in contact with dried residues, therefore without liquid or strong odor.

• - son épaisseur est comprise entre 30 et 100 µm:
• - la résine d'alcool polyvinylique de base contient une proportion en poids d'acétate de vinyle résiduel, non saponifié, qui est comprise entre 0,2 et 0,7 % ;
• - ledit film comporte dans sa masse un plastifiant et un agent anti-blocking ; et
• - avant élimination de l'eau servant à la dissolution aqueuse, la composition en poids dudit film est approximativement la suivante:
• - Résine d'alcool polyvinylique : de 45 à 60 %
• - Plastifiant : de 5 à 20 %
• - Agents anti-blocking : de 0,05 à 0,2 %
• - Eauquantité suffisante pour la dissolution aqueuse de la résine.

For these purposes, according to the invention, the method for producing a device for burying corpses, based on a film of polyvinyl alcohol with delayed aqueous dissolution, obtained from polyvinyl alcohol resin, saponified , is characterized in that a film such as:

• - its thickness is between 30 and 100 µm:
• - The base polyvinyl alcohol resin contains a proportion by weight of residual vinyl acetate, not saponified, which is between 0.2 and 0.7%;
• - Said film comprises in its mass a plasticizer and an anti-blocking agent; and
• - before elimination of the water used for the aqueous dissolution, the composition by weight of said film is approximately as follows:
• - Polyvinyl alcohol resin: 45 to 60%
• - Plasticizer: from 5 to 20%
• - Anti-blocking agents: from 0.05 to 0.2%
• - Sufficient water quantity for the aqueous dissolution of the resin.

Indeed, it has been found that one could act on the duration of the dissolution of a film of polyvinyl alcohol by varying the proportion of residual non-saponified vinyl acetate. Consequently, by adjusting this proportion of residual vinyl acetate according to the thickness of the film, it is possible to delay the apparent onset of aqueous dissolution.

Thus, thanks to the invention, it is possible to make shrouds, mortuary covers or coffin bowls which must have great mechanical resistance for a few tens of days following their contact with the body of a dead being and corresponding to the manipulations. and to the presentation of said body before its burial, but fully biodegradable after several months of contact, that is to say after burial.

It will be noted that the patent GB-A-1 026 349 describes polyvinyl alcohol films containing a molar proportion of residual non-saponified vinyl acetate of 0.2% and having a thickness of 20 μm and 100 μm.

Preferably, according to the invention, in particular when the polyvinyl alcohol film is obtained by calendering (continuous casting), a plasticizer such as glycerine is used.

In order to make the device obtained opaque, opacifiers can be added to the film, such as titanium dioxide and calcium carbonate, in a weight proportion of between 10 and 15%. It will be noted that such an opacifier indirectly plays the role of retarder of aqueous dissolution, since it influences the initial quantity of water necessary for the aqueous dissolution of the resin.

In an advantageous embodiment, in which to obtain said film, all the components, including water, are continuously mixed and the aqueous mixture is heated, then said mixture is spread on a calender where it is heated, a polyvinyl alcohol resin whose saponification of vinye acetate is such that the proportion by weight of non-saponified residual vinyl acetate is between 0.2% and 0.7%, said aqueous mixture, before spreading on the calender, is heated to a temperature between 80 and 95 ° C, and a film is produced whose thickness is between 30 and 100 microns. Said aqueous mixture can be subjected to deaeration before spreading.

Thus, according to the invention, there are obtained devices for the burial of corpses, characterized in that they are manufactured by the implementation of the process specified above and in that they are in the form of shrouds , mortuary covers, coffin or envelope bowls with high mechanical resistance for a few tens of days following their contact with the body of a dead being, but being fully biodegraded after a few months of this contact.

When said device is in the form of a sealed burial envelope, said envelope is advantageously provided with a valve allowing gas communications from the inside of the envelope to the outside. Preferably, this valve makes it possible to create a vacuum in said envelope.

A particular embodiment is described below.

• - 57 kg de granulés de résine d'alcool polyvinylique (ayant un taux résiduel d'acétate de vinyle égal à 0,3 %) ;
• - 14 kg de glycérine à titre de plastifiant ;
• - 17 kg de dioxyde de titane et de carbonate de calcium à titre d'opacifiants ;
• - 0,5 kg d'acide borique à titre de stabilisant ;
• - 0,2 kg d'alkyl aryl polyether à titre d'agent mouillant ;
• - 0,15 kg de stéarates métalliques et de polyols éthoxylés à titre d'agents anti-blocking ;

To make an 80 µm thick film, the following products are poured into the tank of a mixer:

• - 57 kg of polyvinyl alcohol resin granules (having a residual level of vinyl acetate equal to 0.3%);
• - 14 kg of glycerin as plasticizer;
• - 17 kg of titanium dioxide and calcium carbonate as opacifiers;
• - 0.5 kg of boric acid as stabilizer;
• - 0.2 kg of alkyl aryl polyether as wetting agent;
• - 0.15 kg of metal stearates and ethoxylated polyols as anti-blocking agents;

11.15 liters of water.

The aqueous mixture is heated to 85 ° C. and after complete dissolution of the components, the mixture is transmitted to a deaeration tank, then to a spreading calender adjusted to the thickness of 80 μm. The calender is heated to evaporate the water from the film and the film is dried, then wound in a reel.

To determine the mechanical and physical properties of this film, it is subjected to tests at different relative humidity (RH) and at temperatures between 22 and 23 ° C.

• - sens longitudinal N/mm2 39 - 49
• - sens transversal N/mm2 35 - 43

Tensile breaking strength (NF T 54102)

• - longitudinal direction N / mm2 39 - 49
• - transverse direction N / mm2 35 - 43

• - sens longitudinal % 156-171
• - sens transversal % 180-200

Elongation at break in tension (NF T 54 102)

• - longitudinal direction% 156-171
• - transverse direction% 180-200

Water vapor permeability g / dm2 / 24/25 µm

x relative humidity on the faces of the film.

Test conditions: 96 hours at 32 ° C in a saturated atmosphere.

In addition, with this film, bags are formed in which animal corpses are enclosed.

The bags and their contents are buried in the ground and periodic checks have shown that the mechanical resistance of the material of the said bags remains satisfactory for 30 to 60 days and that these disappear gradually from 180 days onwards and are completely eliminated after 260 days. .

With the film according to the invention, it is possible to manufacture envelopes intended to serve as a shroud.

Thus, as soon as death has been confirmed by a doctor, the corpse can be introduced into the envelope made in advance and comprising an opening, after which this opening is closed by welding, for example by means of a portable heat sealer available to the doctor, or any other authorized person. The envelope thus tightly encloses the corpse and prevents odors of decomposition from spreading. The body can remain like this for several days without resulting in odor emissions or hygienic difficulties. Indeed, on the one hand, the welding and the material of the envelope are waterproof and on the other hand, the action of the liquid emissions coming from the corpse on the material of the envelope can for example lead to a beginning of destruction of it in a few dozen days.

In particular in the case where the corpse as a result of an illness would tend to emit large quantities of gases capable of causing the sealed envelope to burst, it is advantageous to equip the latter with a valve allowing said gases to escape. escape bubble to bubble. In this case, it is advantageous that said valve is of the type through which a vacuum can be created. Thus, after the opening of the envelope has been welded, a vacuum is created inside it, for example using a simple vacuum cleaner. Such an aspiration makes it possible to delay the decomposition of the corpse since the atmosphere inside the envelope is rarefied. As a result, the exposure time of the corpse in its envelope can then be extended if necessary.

The envelope may be at least partially transparent to allow exposure of the body to family and friends before burial. However, it is advantageous for the envelope to be transparent only at the level of the face and to be opaque elsewhere, so that the corpse can be enclosed without clothing inside the cover.

In known manner, shortly before the burial, the corpse enclosed in its envelope can be introduced into a coffin. However, thanks to the envelope according to the invention, it is possibly possible to remove said coffin, which is then replaced by said envelope.

The opaque part of this envelope can be decorated and / or colored and / or simulate, for example, clothes.

In addition, the envelope can be scented and / or sanitized.

As mentioned above, the film according to the invention can also be used to produce biodegradable coffin basins.

Claims (8)

1. Method for the production of a device for burying dead bodies, comprising a polyvinyl alcohol film with retarded aqueous dissolution, obtained from a saponified polyvinyl alcohol resin,
characterized in that a film is utilized such as:

- its thickness is comprised between 30 and 100 µm ;

- the basic polyvinyl alcohol resin contains a proportion by weight of residual unsaponified vinyl acetate which is comprised between 0,2 and 0,7 % ;

- said film comprises in its body a plasticizer and an anti-blocking agent ; and

- before removal of water useful for aqueous dissolution, the composition by weight of said film is approximately as follows:

- polyvinyl alcohol resin : from 45 to 60 %

- plasticizer : from 5 to 20 %

- anti-blocking agent :from 0,05 to 0,2 %

- water: amount sufficient for aqueous dissolution of the resin.

2. Method according to claim 1,
characterized in that the plasticizer is glycerin.

3. Method according to claim 1,
characterized in that said film comprises at least one opaquing medium in a proportion by weight comprised between 10 and 25 %.

4. Method according to any one of claims 1 to 3, wherein to obtain said film, all the components inclusive of water are mixed continuously, the aqueous mixture is heated and then said mixture is spread over a calender where it is heated,
characterized in that a polyvinyl alcohol resin is used vinyl acetate saponification of which is such that the proportion by weight of residual unsaponified vinyl acetate is comprised between 0,2 and 0,7 %, in that said aqueous mixture, before being spread over the calender, is heated at a temperature comprised between 80 and 95° C, and in that a film is realized the thickness of which is comprised between 30 and 100 µm.

5. Method according to claim 4,
characterized in that said aqueous mixture is disaerated before being spread.

6. Device for burying dead bodies,
characterized in that it is realized by carrying out the method according to any one of claims 1 to 5, and in that it is in the form of a shroud, a pall, a cuffin bowl or an envelope having a great mechanical strenght during some tens of days after contacting the body of a dead person, but which is entirely biologically degraded after some months of this contact.

7. Device according to claim 6, in the form of a tight burying envelope,
characterized in that said envelope is provided with a valve permitting gas communications from the inside of the envelope to the outside.

8. Device according to claim 7,
characterized in that said valve enables to evacuate said envelope.