Glove having butyl rubber layer to provide resistance to ketone family chemicals

Abstract

A laminate of three layers includes a middle butyl rubber layer, whereas the inner layer and outer layer materials could be chosen from natural rubber latex, carboxylated acrylonitrile butadiene rubber latex, polychloroprene, polyisoprene, carboxylated styrene butadiene, and other synthetic elastomers. Even with one material used for both inner layer and outer layer, different formulations could be used. The resultant multilayer structure provides good resistance to ketone family chemicals such as acetone and MEK. The glove also exhibits superior or much improved resistance to solvent such as DMSO, chloroform, methanol, et al as compared to currently commercially available thin wall gloves made from natural rubber latex and carboxylated acrylonitrile butadiene synthetic rubber latex. The time elapsed before the material experiences breakthrough after exposure to a ketone family solvent is directly related to the thickness of the butyl layer.

Description

BACKGROUND OF THE INVENTION

Gloves are used for their barrier characteristics to protect the wearer from chemicals and contamination. The structure and composition of the glove must be resistant to contamination to prevent contact with the wearer's skin. The structure and material of the glove can be tailored to provide protection from anticipated contaminants.

Published patent applications disclose the structure of gloves resistant to solvents. One such published patent application is 2003/0075828 to Thomas et al disclosing a solid resistant glove formed from multilayers having an elastomeric substrate comprising nitrile rubber. Other published patent applications, 2004/0036196 to Conley and 2004/0107477 to Janssen, disclose surgical or medical gloves made from nitrile rubber and impermeable to many solvents. None of these published patent applications discloses the use of different materials to enhance resistance to chemical solvents and none uses a butyl layer to provide resistance to ketone family solvents.

It is an object of the invention to provide a material resistant to ketone family solvents to be made into gloves.

Another object of the invention is to provide a multilayer glove having a barrier layer of a material resistant to ketone family solvents.

It is another object of the invention to provide a glove made of multiple materials that can be made on existing equipment.

It is another object of the invention to provide a ketone family resistant glove that is inexpensive to manufacture.

These and other objects of the invention will become apparent to one of ordinary skill in the art after reading the disclosure of the invention.

SUMMARY OF THE INVENTION

A laminate of three layers includes a middle butyl rubber layer, whereas the inner layer and outer layer materials could be chosen from natural rubber latex, carboxylated acrylonitrile butadiene rubber latex, polychloroprene, polyisoprene, carboxylated styrene butadiene, and other synthetic elastomers. Even with one material used for both inner layer and outer layer, different formulations could be used. The resultant multilayer structure provides good resistance to ketone family chemicals such as acetone and MEK. The glove also exhibits superior or much improved resistance to solvent such as DMSO, chloroform, methanol, et al as compared to currently commercially available thin wall gloves made from natural rubber latex and carboxylated acrylonitrile butadiene synthetic rubber latex. The time elapsed before the material experiences breakthrough after exposure to a ketone family solvent is directly related to the thickness of the butyl layer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of the laminate of the invention; and

FIG. 2 depicts the method of making the glove.

DETAILED DESCRIPTION OF THE INVENTION

A three-layered sandwich structure shown in FIG. 1 contains an outer layer of nitrile rubber 10, a middle layer of butyl rubber 20 and an inner layer of nitrile rubber 30. This structure provides a resistance to ketone family member solvents. It is possible that other layers of other materials may be added or the three-layered sandwich structure may be repeated.

The formulation of each layer is as follows:

	Nitrile Layers	Butyl Layer
	Base	100	parts	100	parts
	Zinc Oxide	1	part	5	parts
	(Primary activator)
	Sulfur (crosslinker)	1	part	3	parts
	ZDBC (accelerator)	1	part	2	parts
	Titanium Dioxide	1	part	0	parts
	(optional)
	BHT (antioxidant)	1	part	1	part
	Color pigment	0	parts	0	parts
	(optional)

The base of the nitrile layer may be natural rubber latex or nitrile. Throughout the specification, the term ‘nitrile’ is used to encompass these two materials. The base for the butyl layer is butyl latex.

Laminates made in accordance with the invention have demonstrated the following resistance:

Acetone
	Butyl layer	Total film	Breakthrough
Sample film	thickness, mm	thickness, mm	time, min
Nitrile	x	0.1˜0.12	1
1	˜0.04	˜0.1	15

MEK
	Butyl layer	Total film	Breakthrough
Sample film	thickness, mm	thickness, mm	time, min
Nitrile	x	0.1˜0.12	1
1	˜0.02	˜0.1	5
2	˜0.04	˜0.1	15
3	˜0.06	˜0.1	25
4	˜0.09	˜0.1	35

DMSO
	Butyl layer	Total film	Breakthrough
Sample film	thickness, mm	thickness, mm	time, min
Nitrile	x	0.1˜0.12	20
1	˜0.04	˜0.1	45
2	˜0.07	˜0.1	90
3	˜0.1	˜0.1	120

Chloroform
	Butyl layer	Total film	Breakthrough
Sample film	thickness, mm	thickness, mm	time, min
Nitrile	x	0.1˜0.12	1
1	˜0.04	˜0.1	5

Methanol
	Butyl layer	Total film	Breakthrough
Sample film	thickness, mm	thickness, mm	time, min
Nitrile	x	0.1˜0.12	50
1	˜0.04	˜0.1	>60, no BT at
			60, tested
			time up to 60
			minutes.

The three-layered laminate structure is easily formed into gloves by dipping a form 32 into a first vat of nitrile rubber 34 to form a first layer, allowing that layer to cure, then dipping the form 32 having the first layer of nitrile rubber into a second vat having butyl rubber 36 to form a middle layer and allowing the middle layer to cure. Finally, the form 32 is placed into a third vat having nitrile rubber 38 to form the third layer. After final curing, the gloves are removed from the form 32. In the alternative, the form may be placed into the first vat 34 to form the third layer, thereby obviating the need for a third vat. The glove has the advantage of being formed on existing machinery using existing methods.

While the invention has been described with reference to a preferred embodiment, various modifications would be apparent to one of ordinary skill in the art without departing from the scope of the invention. The invention encompasses such various modifications.

Claims

1. A glove, comprising

a first layer of nitrile rubber,

a second layer of butyl rubber, and

a third layer of nitrile rubber.

2. The glove of claim 1, wherein

said first layer is an inner layer,

said second layer is a middle layer and

said third layer is an outer layer.

3. A method of forming a glove comprising

dipping a form into nitrile rubber to form a first layer,

dipping the form into butyl rubber to form a second layer, and

dipping said form into nitrile rubber to form a third layer.

4. The method of claim 3, wherein

said nitrile rubber and butyl rubber are stored in vats.

5. The method of claim 3, wherein

said form is dipped into a first vat having nitrile rubber, then

said form is dipped into a second vat having butyl rubber, then

said form is dipped into a third vat having nitrile rubber.

6. The method of claim 3, wherein

said form is dipped into a first vat having nitrile rubber, then

said form is dipped into a second vat having butyl rubber, then

said form is dipped into said first vat.