EP1983854A2

EP1983854A2 - Highly chemical-resistant glove

Info

Publication number: EP1983854A2
Application number: EP07730881A
Authority: EP
Inventors: Jean Curtet; Olivier Pillard; Christine David; Sandrine Pinchon
Original assignee: Hutchinson SA
Current assignee: Hutchinson SA
Priority date: 2006-02-02
Filing date: 2007-01-29
Publication date: 2008-10-29
Anticipated expiration: 2027-01-29
Also published as: WO2007088265A2; FR2896667A1; JP2009525411A; DE602007001448D1; EP1983854B1; US20090068443A1; ATE434949T1; WO2007088265A3; FR2896667B1

Abstract

The invention concerns an article for protecting the user from risks associated with the handling of chemicals, and comprising: (i) at least one inner layer of a material selected among natural and synthetic latexes; (ii) at least one partly hydrolyzed polyvinyl alcohol (PVA) layer, having an hydrolysis rate ranging between 70 and 95%; (iii) at least one self-crosslinking synthetic latex layer.

Description

GLOVE HAVING HIGH CHEMICAL RESISTANCE

The present invention relates to a protective article to protect the user from the risks associated with the handling of chemicals.

For the protection of users when handling hazardous chemicals, multilayer materials are usually used which comprise at least one layer of a material impervious to said chemicals, i.e. a barrier material. The effectiveness of the barrier effect of a material is determined by its resistance to permeation, which is measured by the time it takes for a given chemical to pass through the material. Materials used to make personal protective equipment must also have sufficient mechanical strength and puncture resistance for common use, such as in a laboratory or workshop.

In addition, to allow the user to handle various objects and tools, a protective garment such as a glove which has a three-dimensional structure, which is devoid of seams or external welds and which is flexible is preferred. so that you can marry the user's movements. Finally, we also expect such a glove that it is resistant to water.

Generally, a barrier material provides protection against a limited number of chemicals. When a user has to handle several products belonging to different chemical families, a common solution is to superimpose resistant gloves to each of these families in order to provide additional protection. This solution, resulting in a superimposition not very ergonomic, has the disadvantage of hindering handling.

Document WO 02/080713 discloses a protective glove intended for protection against chemicals, this glove being constituted by a layer of a rubber latex and a layer of polyvinyl alcohol.

According to this document, the inner layer, which is in contact with the skin of the user, is made of polyvinyl alcohol while the outer layer is made of rubber. The outer layer of rubber, which is resistant to water, is very easily degraded in contact with certain solvents organic. Therefore these gloves are not suitable for handling these chemicals.

Protective articles having a multilayer structure based on polyolefin and on EVOH are also known: US Pat. No. 5,491,022, US 5,059,447, US Pat. No. 4,855,178, US 5,162,148. protection have the disadvantage of providing a low level of chemical protection vis-à-vis amines (methylamine, ethylamine, ..) and to have a low mechanical and thermal protection and low elasticity. On the other hand, these materials, when assembled to produce a glove, have at the welds extra thickness relative to the rest of the material, which is not the case for articles obtained by dipping.

Chemical protection has two complementary aspects: On the one hand, it is evaluated for a certain number of chemicals the duration during which a barrier material resists permeation by each of these products taken individually. On the other hand it is considered, for a desired duration of resistance, how many families of different chemicals such a material barrier.

The object of the invention was to provide a barrier material for as many chemicals as possible for as long as possible. We have also tried to develop a glove resistant to water. Compared to the articles of the prior art, it has been sought to improve the time during which the material is a barrier to chemicals and to broaden the spectrum of families of products that are stopped by this material. In addition we sought to obtain an article, including a glove, water resistant and satisfactory flexibility. Such a result has been obtained according to the present invention by the superposition of a layer of natural or synthetic latex, a partially hydrolyzed polyvinyl alcohol layer, a layer of a synthetic latex and optionally a silica-based topcoat and a dispersion of a cationic fluoropolymer.

US-5,438,709 discloses an elastomeric glove covered with a layer of polyvinyl alcohol and a thickening agent. The polyvinyl alcohol used is of a fully hydrolysed quality. The gloves described in this document are more particularly intended to be used as a base for forming an orthopedic bandage, because of their slippery character in the presence of water.

JP 56-078930 discloses a textile glove which is dipped in a polyvinyl alcohol solution and then dried and dipped in a dispersion of a polyvinyl chloride (PVC) resin, before being demolded. This process gives a textile glove that is pleasant and flexible contact.

The subject of the invention is a protective article, preferably a glove, offering improved protection against penetration by chemicals, this article comprising:

(i) at least one inner layer of a material selected from natural and synthetic latices;

(ii) at least one layer of partially hydrolyzed polyvinyl alcohol (PVA) having a degree of hydrolysis of 70 to 95%;

(iii) at least one layer of a self-crosslinking synthetic latex. According to an advantageous variant of the invention, the protection article further comprises:

(iv) at least one layer of a mixture of silica and a cationic fluorinated resin.

With respect to the barrier materials of the prior art, and as will be demonstrated in the experimental part, the materials of the invention make it possible to increase the duration of passage of said material by the solvents and to constitute a barrier against a wider range of chemicals. In addition, this material and the articles obtained from this material are of remarkable elasticity with respect to multi-layer materials of the prior art and are water resistant.

In more detail, the articles of the invention preferably comprise a support layer consisting of a textile. It may be a fabric or a knit, based on a natural fiber such as cotton, wool, linen, viscose, or synthetic fiber such as polyester, polyamide, of polyethylene, in particular high modulus and high tenacity polyethylene, aramid or para-aramid, or a mixture of several types of fibers.

Preferably, the textile support is cotton.

The textile support layer, which is in contact with the skin of the user, is intended both to promote the mechanical strength of the article of the invention and to offer a pleasant contact to the user during long use. .

The latex layer (i) is chosen for its chemical barrier properties. It is chosen from natural latices and synthetic latices.

A natural latex layer has the advantage of giving greater flexibility to the protective articles and, at equal thickness, of being less expensive than a layer of synthetic latex.

According to whether or not a textile support is used, the latex layer may constitute the first or the second thickness of the protective article from the skin of the user and towards the outer face of the article. protection. When the latex layer (i) is chosen from synthetic latices, it may consist of a polychloroprene latex, but also a nitrile or butyl rubber, a polyvinyl chloride, a fluoroelastomer, a polyurethane, a chlorosulfonylpolyethylene, a chlorinated polyethylene, an ethylene acrylic, a polyacrylate or a combination of these materials. According to one variant, provision may be made for using a layer of natural latex to which a layer of synthetic latex is superimposed.

Next if we build the protective article from a textile support and / or a layer of natural latex or if we choose instead to use the lowest number of different materials, the synthetic latex may constitute the support layer or the second or third layer of the protection article of the invention.

Advantageously, the last layer of latex is covered with an adhesion layer intended to promote better adhesion of the polyvinyl alcohol layer to the latex. This intermediate adhesion layer may consist of any material known to those skilled in the art and capable of performing this function. It may be in particular a mixture of latex, identical to that used in (i) and PVA used in (ii). Preferably, a mixture of an acrylic latex and PVA used in (ii) is chosen. The adhesion layer improves the mechanical strength of the protective article, particularly its peel strength, and contributes to the flexibility of the article.

According to a variant of the invention, the application of the adhesion layer may be replaced by the application of a coagulant of the polyvinyl alcohol.

A layer (ii) of polyvinyl alcohol (PVA) is then provided, either directly on the latex, or on the intermediate adhesion layer, or on the PVA coagulant. This layer (ii) consists of partially hydrolyzed polyvinyl alcohol having a degree of hydrolysis of between 70 and 95%, preferably between 85 and 90%.

The layer (iii) of synthetic latex may consist of any synthetic latex as already described above for layer (i). Preferably, the layer (iii) of synthetic latex is chosen from acrylic latices, styrene-butadiene latices and self-crosslinking nitrile latices.

Preferably, the layer (iii) of synthetic latex also comprises polyvinyl alcohol. The polyvinyl alcohol used in layer (iii) has any degree of hydrolysis. Preferably, it has a degree of hydrolysis of between 70 and 95%. Advantageously, the polyvinyl alcohol of layer (iii) is the same as that of layer (ii).

The proportion of latex and polyvinyl alcohol in the mixture of the layer (iii) is between 3 and 10%, preferably 4 to 8% of polyvinyl alcohol, by weight of active material relative to the weight of synthetic latex.

When present, the outer layer (iv) is advantageously constituted by a mixture of silica in aqueous dispersion and a cationic fluorinated resin. Preferably, the silica is a precipitated silica or a fumed silica. Preferably, the silica is a fumed silica of colloidal nature. The successive layers (i) to (iii) described above constitute the minimum structure of the protective articles of the invention. As already discussed, optional layers may be provided at the indicated locations, but other variations are possible around this basic structure. In addition, some layers may be present in several thicknesses.

For example, the latex of the layer (i) or the PVA of the layer (ii), the latex of the layer (iii) and optionally the mixture of the layer (iv) can be applied repeatedly with a drying step intermediate between two applications. Preferably, the protective article of the invention comprises a layer thickness (i) of natural or synthetic latex ranging from 100 to 400 microns.

Preferably, the protective article of the invention comprises a layer of polyvinyl alcohol (ii) with a thickness of between 30 and 200 μm.

Advantageously, the protective article of the invention comprises a layer thickness (ii) of PVA, with a hydrolysis rate ranging from 70 to 95%, from 60 to 150 μm and a thickness of synthetic latex layer (iii). with a thickness of 10 to 20 μm.

Preferably, the protective article of the invention comprises a layer of mixture (iv) of silica and fluororesin with a thickness ranging from 1 to 5 microns.

Preferably, the thickness of the adhesion layer is between 5 and 50 microns.

Surprisingly, the resistance to penetration by solvents of the protective articles of the invention is greater than the sum of the strengths of each of the constituent materials of these articles. Polychloroprene and partially hydrolyzed PVAs are known for their resistance to permeation by chemicals. However, nothing indicated in the prior art that the materials of the invention, when present in the same protection article and in the order indicated above, make it possible to obtain a protection much higher than the sum of the protections conferred by each of the individual materials. In addition, the protective articles of the invention have good water resistance and are of satisfactory flexibility.

Another object of the invention is a method of producing a protective article for protecting the manipulator from the risks associated with the use of chemicals.

Such a method comprises the following steps: a) optionally, dressing a mold with a textile layer; b) optionally dipping the mold or the mold / textile assembly resulting from step a) in a coagulating solution; c) dipping the mold or the mold / textile assembly from step a) or step b) into one or more aqueous dispersions of natural or synthetic latex (i); d) optionally dipping the coated mold from step c) in water to allow removal of the coagulant solution; e) drying and optionally vulcanization of the coated mold from step c) or step d); f) optionally dipping the coated mold obtained at the end of step c), d) or e) in one or more adhesion layers; g) dipping the coated mold obtained at the end of step c) or step d) or e) or f) in one or more aqueous solutions of partially hydrolyzed PVA of hydrolysis rate of between 70 and 95; %. h) dipping the coated mold obtained at the end of step g) in one or more aqueous dispersions of self-crosslinking synthetic latex, preferably chosen from acrylic latices, styrene-butadiene latices or nitrile latices; i) non-obligatorily, but preferably, dipping of the coated mold obtained at the end of step h) in one or more aqueous dispersions of a cationic fluorinated resin comprising silica; and in the final step: j) removal of the glove by sliding on the mold.

The textile support, or the mold, is coated with natural or synthetic latex by a quenching operation known to those skilled in the art. Each quenching step is optionally followed by drying and a step of vulcanization or gelling in an oven.

When the coating comprises a layer of a natural latex, the invention provides for dipping the optionally coated mold in a solution for coagulating the latex, then drying, then optionally soaking in one or more synthetic elastomer baths, each quenching being followed by drying until complete coagulation of the elastomer and then rinsing in water or in any solvent allowing the removal of the coagulant solution.

In known manner, each dipping step f) to i) is followed by drying for a period of 5 minutes to about 1 hour, at a temperature of 30 to 90 ° C. In a manner known to the man of job, it is expected at the end of step h) or step i) to dry the article and then vulcanize it before removing it from the mold.

If the dipping technique is particularly suitable for the manufacture of protective equipment such as gloves, overboots, and more generally, all items having a three-dimensional structure, it is also possible, according to a variant of the invention, to manufacture a protection article according to the invention by using other technologies known to those skilled in the art such as coating, since the succession of the layers of materials described above is reconstituted in the order indicated. The invention further relates to the protective articles described above and characterized in that they are in the form of a glove, an overboot, a combination, a hood, a tarpaulin , pants, jacket.

The aqueous solutions of polyvinyl alcohol being generally very dilute, it is preferably carried out several successive dipping in step g). EXAMPLE:

1. Manufacture of a glove: a- One dresses a shape using a cotton textile. b- The dressed form is soaked for 10 seconds in a coagulating solution. c- The dressed shape is soaked for 120 seconds in a natural latex bath. The form is then quenched for 20 seconds in a polychloroprene latex bath. This operation is repeated so as to form a second layer of polychloroprene latex. The shape is then soaked in water to allow the removal of the coagulating solution. After drying and vulcanization of the preceding layers, the form is soaked for 5 seconds in a bath consisting of:

. 88% by weight of acrylic latex (CRAYMUL marketed by CRA YV ALLE Y)

4% by weight of TiO ₂

8% by weight of PVA (MOWIOL 18-88 sold by the company SEPPIC)

The percentages are given by weight of dry matter in the composition. The composition is in the form of an aqueous dispersion at 30% solids content. After drying for 15 minutes at 75 ° C., the form is soaked for 5 seconds in a bath consisting of:

60% of PVA (MOWIOL 18-88 sold by the company SEPPIC)

30% glycerin

10% of silica (AEROSIL A200 marketed by BRENNTAG)

The percentages are given by weight of dry matter in the composition. The composition is in the form of an aqueous dispersion containing 12% solids. Operation g- is repeated a second time. After drying for 30 minutes at 75 ° C., the form is soaked for 5 seconds in a bath consisting of:

- 90% by weight of acrylic latex (CRAYMUL) - 1.5% by weight of TiO ₂

- 7% by weight of PVA (MOWIOL 20-98 sold by the company SEPPIC)

1.5% by weight of an acid catalyst (diammonium chloride). The percentages are given by weight of dry matter in the composition. The composition is in the form of an aqueous dispersion containing 28% solids. After drying for 30 minutes at 85 ° C., the form is soaked for 2 seconds in a bath consisting of: 71% by weight of water

- 20% by weight of colloidal silica (Bindzil marketed by the company Eka Chemicals)

- 9% by weight of an aqueous dispersion of cationic fluorinated polymer (OLEOPHOBOL marketed by CIBA).

The percentages are given by weight of dry matter in the composition. The composition is in the form of an aqueous dispersion containing 18% solids.

The glove is crosslinked by heating at 120 ^° C. for 30 minutes and it is demolded.

The glove obtained has the following characteristics measured at the bottom of palm:

- thickness of the natural latex layer (c-): 300 μm

- polychloroprene layer thickness (d-): 260 μm - thickness of the acrylic adhesion layer (f-): 10 μm thickness of the PVA layer (g-) (88% hydrolysis rate): 130 μm

- thickness of the acrylic layer (h-): 20 μm thickness of the topcoat (i-): 2 μm. 2. Variant in the manufacture of a glove:

The process of Example 1 is repeated by eliminating step (i-) and using in step (h-) a dispersion consisting of:

97% by weight of a styrene-butadiene latex (SYNTHOMER marketed by SYNTHOMER LtD.) - 1.5% by weight of TiO ₂

1.5% by weight of an acid catalyst (diammonium phosphate).

The percentages are given by weight of active ingredient in the composition. The composition is in the form of an aqueous dispersion containing 40% solids.

3. Variant in the manufacture of a glove:

97% by weight of a nitrile latex (PERBUNAN marketed by POLYMER LATEX)

1.5% by weight of TiO ₂

1.5% by weight of a melanin resin (PROX marketed by SYNTHRON). The percentages are given by weight of active ingredient in the composition. The composition is in the form of an aqueous dispersion at 45% solids content.

4. Permeation by a wider range of solvents:

Another glove (Cl) is prepared for comparison, reproducing steps a, b, c, d and e of Example 1 and crosslinking the glove obtained for 3 hours at 130 ° C.

Permeation tests according to the EN 374-3 standard are made comparatively on the glove of Example 1 and on the glove Cl. The results are shown in Table 1. They are expressed as a passage time for each solvent in minutes according to EN 374-3.

Table 1: Evaluation of the Versatility of Protection. 5- Resistance to water: PROCEDURE

- Cut out three pellets in the palm of 66 mm diameter in three gloves. - Weigh the three dry pellets (PS).

The pellets are then fixed in each of the absorption cells, the external face being placed towards the side containing the demineralized water.

- Fill the cell with deionized water.

- Turn over and put in an oven at 23 ° C for 10 minutes. - Empty the cells and extract the pellets.

- Stamp the tablets with Joseph paper.

- Weigh the different wet pellets (PH).

- View the film after contact (observation). EXPRESSION OF RESULTS - Calculate the swelling according to the formula:

- Calculate the mean and standard deviation of each series of tests.

This method determines the water swelling of the outside of a glove. The principle is based on the ability of a film to swell in contact with water.

The glove of the invention (Example 1) has a mass swelling evaluated by its variation index of 8.7% by weight after 90 minutes without visual degradation.

The good water resistance of the glove of the invention can be illustrated by the test below.

Swelling with water then drying until equilibrium and permeation test according to EN 374-3 with diethylamine. Transit time

After 1 hour: 61 minutes After 2 hours: 51 minutes

After 4 hours: 47 minutes 5-Mechanical resistance of the glove of Example 1: The multilayer glove of Example 1 has peel strengths between layers (ii) and (i) of a minimum value of 4.5 N / cm according to the standard ISO 36. In addition, this glove has the following mechanical properties according to EN 374-3.

Abrasion: Level 3 Cleavage: Level 1 Tearing: Level 4 Perforation: Level 1.

Claims

1. Protection article comprising:

(i) at least one inner layer of a material selected from natural and synthetic latices; (ii) at least one layer of partially hydrolyzed polyvinyl alcohol (PVA) having a degree of hydrolysis of 70 to 95%;

(iii) at least one layer of a self-crosslinking synthetic latex.

2. Article according to claim 1, characterized in that it further comprises:

3. Article according to claim 1 or claim 2, characterized in that it further comprises a support layer consisting of a natural fiber textile or synthetic.

4. Article according to claim 3, characterized in that the support layer is cotton.

5. Article according to any one of the preceding claims, characterized in that it comprises a layer (i) based on a natural latex, which constitutes the first or the second thickness of the protective article.

6. Article according to claim 5, characterized in that the thickness of natural latex is between 100 and 400 microns.

7. Article according to any one of the preceding claims, characterized in that it comprises a layer (i) of synthetic latex selected from a polychloroprene latex, a nitrile rubber, a butyl rubber, a polyvinyl chloride, a fluoroelastomer, polyurethane, chlorosulfonylpolyethylene, chlorinated polyethylene, ethylene acrylic, polyacrylate or a combination of these materials.

8. Article according to claim 7, characterized in that the thickness of the layer (i) of synthetic latex is between 100 and 400 microns.

9. Article according to any one of the preceding claims, characterized in that the latex layer (i) is covered with an adhesion layer.

10. Article according to claim 9, characterized in that the adhesion layer comprises a mixture of an acrylic latex and a polyvinyl alcohol (ii).

11. Article according to claim 9 or claim 10, characterized in that the thickness of the adhesion layer is between 5 and 50 microns.

12. Article according to any one of the preceding claims, characterized in that the layer (ii) of polyvinyl alcohol consists of partially hydrolyzed polyvinyl alcohol having a degree of hydrolysis of between 85 and 90%.

13. Article according to any one of the preceding claims, characterized in that the layer (iii) of synthetic latex is chosen from acrylic latices, styrene butadiene latices and self-crosslinking nitrile latices.

14. Article according to any one of the preceding claims characterized in that the layer (iii) of synthetic latex comprises polyvinyl alcohol.

15. Article according to any one of the preceding claims, characterized in that it comprises a thickness of synthetic latex layer (iii) between 10 and 20 microns.

16. Article according to any one of the preceding claims, characterized in that it comprises a polyvinyl alcohol thickness (ii), with a hydrolysis rate ranging from 70 to 95%, from 60 to 150 microns.

17. Article according to any one of claims 2 to 16 above, characterized in that it comprises a layer (iv) of silica mixture and a cationic fluorinated resin having a thickness between 1 and 5 microns.

18. Article according to any one of the preceding claims, characterized in that it is in the form of a glove, an overboot, a combination, a hood, a tarpaulin, a pants, a jacket.

19. Article according to any one of the preceding claims, characterized in that it withstands more than 30 minutes permeation by each of the following solvents: acetone, dichloromethane, toluene, ethyl acetate, n-heptane, n-hexane , Tetrahydrofuran, Methanol, Diethylamine, Sodium Hydroxide 40%, Sulfuric Acid 96%, Acetonitrile, Carbon Disulfide, Ammonia, Chlorine, Hydrogen Chloride, under the test conditions of EN374-3.

20. A method of producing a protective article according to any one of claims 1 to 19, characterized in that it comprises the following steps: a) optionally, dressing a mold with a textile layer; b) optionally dipping the mold or the mold / textile assembly resulting from step a) in a coagulating solution; c) dipping the mold or the mold / textile assembly from step a) or step b) into one or more aqueous dispersions of natural or synthetic latex (i); d) optionally dipping the coated mold from step c) in water to allow removal of the coagulant solution; e) drying and optionally vulcanization of the coated mold from step c) or step d); f) optionally dipping the coated mold obtained at the end of step c), d) or e) in one or more adhesion layers; g) dipping the coated mold obtained at the end of step c) or step d) or e) or f) in one or more aqueous solutions of PVA partially or completely hydrolyzed hydrolysis rate between 70 and 95%. h) dipping the coated mold obtained at the end of step g) into one or more aqueous dispersions of self-crosslinking synthetic latex; i) optionally dipping the coated mold obtained at the end of step h) in one or more aqueous dispersions of cationic fluorinated resin comprising silica; and in a final step: j) removing the glove by sliding on the mold.

21. The method of claim 20, characterized in that each dipping step f) to i) is followed by drying.