RU2784098C1 - Composition for manufacturing latex-based gloves - Google Patents

Abstract

FIELD: rubbers.

SUBSTANCE: invention relates to dipped articles based on synthetic latex, in particular, to household nitrile gloves with textured fingers, intended to protect the hands from water, non-toxic substances, and fouling. Claimed is a composition for manufacturing latex-based gloves, containing potassium oxide hydrate, casein, aqueous ammonia, NF dispersing agent, zinc oxide, sulphur; additionally, the composition contains butadiene nitrile latex, agidol, ZDEC, and pigment paste.

EFFECT: improved composition for moulding gloves for the purpose of protecting the hands from the impact of surface-active agents contained in huge amounts in detergents.

1 cl, 11 tbl

Description

The invention relates to dipped products based on synthetic latex, in particular to household nitrile finger textured gloves designed to protect hands from water, non-toxic substances and dirt.

From the patent RU 2358626 (IPC A41D 19/00, publ. 06/20/2009), a latex composition based on nitrile letex with a high content of potassium hydroxide is known.

However, this composition can affect the skin of human hands, causing allergic reactions, and it is also susceptible to surfactants.

Known composition for the production of latex gloves (patent RU 2771752, IPC C08L 9/04, C08L 9/10, publ. 05/11/2022), which includes latex and vulcanizing agents. Other components are introduced into the composition at will, based on the further use of the latex product. In a particular case, to obtain gloves, a latex composition can be prepared, consisting of 96-97 wt. % latex on a dry matter basis, 3.0-3.6% curing agent, 0.2-0.3% fatty alcohol sulfoester salt and 0.1-0.2% antioxidant based on the total dry matter of the composition taken as 100%. Sulfur, zinc oxide, zinc diethyldithiocarbamate, titanium dioxide can be used as vulcanizing agents for compositions for film products. Vulcanizing agents are introduced into the composition of the latex composition in the form of dispersions in the emulsifier. The emulsifier is selected from the group of salts of sulfoesters of fatty alcohols or ethoxylated salts of sulfoesters of fatty alcohols with a degree of oxyethylation of 2-10. The preferred option is ethoxylated salts of sulfoesters of fatty alcohols with a degree of ethoxylation of 2-10. Emulsifiers introduced during the production of latexes according to the invention act as size stabilizers for dispersed particles and prevent their agglomeration and precipitation from dispersions. As a dispersion stabilizer, NF dispersant can be used - the sodium salt of the condensation product of naphthalene sulfonic acid and formaldehyde, which provides effective particle stabilization, but causes coloring of curing agent dispersions, which gives dark shades to products obtained by ionic deposition.

Patent RU 2694346 (IPC C08L 21/02, publ. 07/11/2019) describes a latex composition for the manufacture of elastomeric products containing a mixture of a base polymer, the base polymer being a carboxylated acrylonitrile-butadiene polymer; a crosslinking agent; with pH regulator for a pH range of 9.5 to 10.5. The crosslinker is a mixture of a trivalent metal or a trivalent metal compound; polyethylene glycol, wherein the polyethylene glycol of ethylene glycol has a molecular weight ranging from 200 Daltons to 200,000 Daltons; a hydroxide ion containing compound, wherein the hydroxide ion containing compound is selected from the group consisting of potassium hydroxide, sodium hydroxide, ammonium hydroxide, or mixtures thereof. A method for producing a latex composition and elastomeric gloves are also described.

Known latex composition for the manufacture of nitrile industrial gloves (patent RU 2358626, IPC A41D 19/00, publ. 20.06.2009):

Composition Dry weight, % Nitrile latex 100 Potassium hydroxide solution 65 Sodium lauryl sulfate 0.72 zinc oxide 3.25 Sulfur 0.5 Dithiocarbamate Accelerator 0.25 bactericidal agent 0.25 Antifoaming agent 0.6 color pigment 0.3 Titanium dioxide 0.5

Known latex for the manufacture of products by immersion dipping (patent RU 2771752, IPC C08L 9/04, C08L9/10, publ. 05/11/2022), containing structural units formed from at least one monomer, which is a conjugated diene, according to at least one monomer which is acrylic acid nitrile; and at least one monomer which is an unsaturated carboxylic acid.

Closest to the claimed is a composition for the manufacture of gloves based on natural rubber (patent RU 2548436, IPC C08J 5/02, C08L 7/02, C08L9/08, publ. 20.04.2015), containing potassium hydroxide, naphtha, casein, ammonia water, NF dispersant, zinc diethyldithiocarbamate, zinc oxide, sulfur. The composition also contains styrene-butadiene latex, oleic acid, thiourea, carbon black, polymethylsiloxane liquid and dibutyl phthalate in the following ratio, wt. %:

natural latex 90.91 Styrene-butadiene latex 1.85 Potassium hydroxide 0.33 Oleic acid 0.17 Naftam 0.83 Casein 0.16 Ammonia water 0.01 Dispersant NF 0.28 Zinc diethyldithiocarbamate 2.62 zinc oxide 0.29 Sulfur 0.44 thiourea 0.58 Technical carbon 0.99 Polymethylsiloxane liquid 0.09 dibutyl phthalate 0.45

However, these compositions are susceptible to surfactants and destroy the latex film.

The technical problem is to create household nitrile gloves designed to protect hands from water, non-toxic substances and dirt.

The technical result of the invention is the improvement of the composition for molding gloves in order to protect hands from the effects of surfactants contained in large quantities in detergents.

The technical result is achieved by introducing butadiene nitrile latex, agidol, ethylcymate and pigment paste into a composition for making gloves containing potassium oxide hydrate, casein, aqueous ammonia, NF dispersant, zinc oxide and sulfur, in the following ratio, wt. %:

Nitrile Butadiene Latex 93.392 Potassium hydroxide 0.013 Agidol 0.94 Casein 0.18 Ammonia water 0.005 Dispersant NF 0.13 Ethylcymate 2.67 zinc oxide 1.38 Sulfur 1.07 pigment paste 0.22

The manufacturing process of the inventive gloves includes several stages.

Prepare solutions and dispersions that are part of the latex mixture and coagulant.

The preparation of solutions and dispersions that are part of the latex mixture is carried out on equipment according to recipes, temperature and time conditions.

Softened water or condensate is obtained from the steam power plant.

Preparation of the latex mixture .

The preparation of the latex mixture is carried out according to the recipe. Before preparing the latex mixture, it is necessary to homogenize the latex in a reactor or a vat equipped with a stirrer for at least 30 minutes.

The formulation of the latex mixture based on butadiene nitrile latex is shown in table 1.

Table 1. Material name
(ingredient) Parts of mass per 100 ppm
dry matter
texa %% by mass Latex butadiene nitrile 100,000 93.392 Potassium hydroxide 0.014 0.013 Powder 2246 (agidol) 1.0 0.94 Casein 0.098 0.18 Ammonia water 25% 0.0057 0.005 Dispersant NF 0.14 0.13 Ethylcymate 2.85 2.67 zinc oxide 1.47 1.38 Sulfur 1.15 1.07 The pigment paste is blue.
Lacanil Aqua 5017 0.24 0.22 TOTAL: 107.07 100,000

Latex from barrels through the filter is poured into a container with a volume of 1.2 m ³ . With constant stirring, semi-finished products are introduced in the sequence indicated in the recipe. After the introduction of each of the semi-finished products, the mixture is stirred for 15±5 minutes. and leave to mature for at least 48 hours at ambient temperature to remove air bubbles.

Preparation of solutions, dispersions, emulsions .

The recipe for preparing a solution of potassium hydroxide is given in table 2.

Table 2. Name of ingredients Parts of mass in
natural
expression, g Bulk
share of dry matter
entities in
solution, % Bulk
share of ak-
active
substances, % Weight
ingre-
dients,
kg Potassium hydroxide 10.0 10.0 10.0 10.0 Softened water 90.0 - - 90.0 TOTAL: 100.0 10.0 10.0 100.0

A portion of potassium hydroxide is dissolved in softened water with stirring for 20 minutes.

The recipe for preparing the NF dispersant solution is given in Table 3.

Table 3 Name of ingredients Parts of mass in
natural
expression, g Bulk
percentage of solids in
solution, % Bulk
share of ak-
active
substances, % Weight
ingre-
dients,
kg Dispersant NF 10.0 10.0 10.0 10.0 Softened water 90.0 - - 90.0 TOTAL: 100.0 10.0 10.0 100.0

A weighed portion of the NF dispersant is dissolved in softened water with stirring for 20 minutes.

The recipe for the preparation of ammonium caseinate solution is given in table 4.

Table 4 Name of ingredients Parts of mass in
natural
expression, g Bulk
percentage of solids in
solution,
% Bulk
share of ak-
active
substances, % Weight
ingre-
dients,
kg Casein 8.0 8.0 8.0 8.0 Ammonia water, 25% 1.9 0.475 - 1.9 Softened water 90.0 - - 90.1 TOTAL: 100.0 8.475 8.0 100.0

The container is filled with a measured amount of water heated to a temperature of (60 ± 10) ° C, a measured amount of ammonia is added there, mixed and the required amount of casein is added.

Stirred for 60 min. Shelf life 48 hours.

The recipe for preparing a hydrochloric acid solution is given in table 5.

Table 5 Name of ingredients Parts of mass in
natural
expression, g Bulk
share of solids in solution, % weight of ingredients,
kg Hydrochloric acid, 36% 13.89-27.78 5.00-10.00 13.89-27.78 Softened water 86.11-72.22 - 86.11-72.22 TOTAL: 100.00-100.00 5.00-10.00 100.00

A weighed amount of hydrochloric acid is added to the water and stirred for (5 ± 1) min.

The recipe for preparing a solution of soda ash is shown in table 6.

Table 6 Name of ingredients Parts of mass in
natural
expression, g Bulk
share of dry matter
substances in solution, % Ingredient weight
dients,
kg soda ash 7.00-10.00 7.00-10.00 7.00-10.00 Softened water 93.00-90.00 - 93.00-90.00 TOTAL: 100.00 7.00-10.00 100.00

A portion of soda ash is dissolved in a measured amount of water with a temperature of (60 ± 10) ° C and stirred until completely dissolved.

The recipe for the preparation of the accelerator dispersion is given in Table 7.

Table 7 Name of ingredients Parts of mass
in kind
nominal expression
nii, g Bulk
proportion of dry
substances in
emulsions,% Bulk
share asset
nyh ve-
entities in
emulsions Weight ing-
redients,
kg Ethylcymate 40.00 40.00 40.00 20.80 Ammonium caseinate solution
8.475% 13.0 1.10 - 6.97 Dispersant solution NF, 10% 8.00 0.80 - 4.16 Potassium hydroxide solution, 10% 2.00 0.20 - 1.04 Softened water 36.16 - - 19.03 TOTAL: 100.00 42.10 40.00 52.00

Bulk ingredients are weighed, loaded into a ball mill and a weighed amount of ammonium caseinate, NF dispersant solution and potassium hydroxide are added there. The dispersion is treated for 48 hours. The shelf life of the dispersion is not more than 5 days.

The zinc oxide dispersion recipe is given in Table 8.

Table 8 Name of ingredients Parts of mass
in kind
nominal expression
nii, g Bulk
proportion of dry
substances in
emulsions,% Bulk
share asset
nyh ve-
entities in
emulsions Weight ing-
redients,
kg zinc oxide 40.0 40 40.0 20.0 Dispersant solution NF, 10% 9.0 0.9 - 4.5 Softened water 51.0 - - 25.5 TOTAL: 100.0 40.9 40.0 50.0

Zinc oxide is weighed, loaded into the mill, the NF dispersant solution and softened water are also added there. The dispersion is treated for 48 hours. The shelf life of the dispersion is not more than 5 days.

The recipe for the preparation of the antioxidant dispersion is given in Table 9.

Table 9 Name of ingredients Parts of mass
in kind
nominal expression
nii, g Bulk
proportion of dry
substances in
emulsions,% Bulk
share asset
nyh ve-
entities in
emulsions Weight ing-
redients,
kg Powder 2246 (agidol) 40.0 40.0 40.0 twenty Ammonium caseinate solution, 8.475% 30.0 2.5 - 15.0 Dispersant solution NF, 10% thirty 3.0 - 15.0 TOTAL: 100.0 45.5 40.0 50.0

The powder is weighed, loaded into the mill, and a solution of the NF dispersant and ammonium caseinate is also introduced there. The dispersion is treated for 48 hours. The shelf life of the dispersion is not more than 5 days.

The recipe for the preparation of a sulfur dispersion is given in table 10.

Table 10 Name of ingredients Parts of mass
in kind
nom expression
nii, g Bulk
proportion of dry
substances in
emulsions,% Bulk
share asset
nyh ve-
entities in
emulsions Weight ing-
redients,
kg Sulfur 40.0 40.0 40.0 20.0 Ammonium caseinate solution 8.475% 15.0 1.3 - 7.5 Ammonia, 25% 2.0 0.5 - 1.0 Softened water 43.0 - - 21.5 TOTAL: 100.0 41.8 40.0 50.0

Sulfur is weighed, loaded into the mill, a weighed amount of ammonium caseinate solution, ammonia and softened water are also introduced there. The dispersion is processed (72±2) hours. Shelf life is not more than 5 days.

Preparation of aqueous coagulant.

The recipe for the preparation of an aqueous coagulant is shown in table 11.

Table 11 Name of ingredients Parts of mass
in kind
nominal expression
nii, g Bulk
proportion of dry
substances in
emulsions,% Bulk
share asset
nyh ve-
entities in
emulsions Weight ing-
redients,
kg Calcium nitrate 40.0 40.0 40.0 520.0 Softened water 60.0 - - 780.0 TOTAL: 100.0 40.0 40.0 1300.0

Calcium nitrate is loaded into a jacketed container, where it is melted at a temperature of (75±5)°C. A portion of the molten calcium nitrate is loaded into the reactor and softened water according to the recipe. The coagulant is stirred (35±5) min.

After analysis, pour into a dipping bath.

The production of gloves is carried out on the production line JB-RJA01.

The molds pass through a vulcanizing oven, gaining a temperature of up to 110°C, and then through hot water flares, after which the water is shaken off. Dip the form in the coagulant, shake off the excess coagulant. Dry the coagulant in the drying chamber for 30 seconds. Dip molds with coagulant into the latex mixture. Forms of hands with a latex mixture enter the drying chamber for 30 seconds. Carry out the rolling of the corolla. The molds are then immersed in a bath of glove surface treatment solution. The gel is dried and vulcanized on molds for 55 minutes. Remove the gloves from the molds by hand and dust them. Checked for defects and packaged.

An example of the preparation of the claimed composition .

Prepared solutions and dispersions included in the composition of the latex mixture. To do this, a sample of potassium hydroxide was dissolved in softened water with stirring until complete dissolution. A weighed portion of the NF dispersant was dissolved in softened water with stirring. The container was filled with a measured amount of water heated to a temperature of (60±10)°C, a measured amount of ammonia was added there, mixed, and the required amount of casein was added. Stirred for 60 min. Zinc oxide was weighed, loaded into a mill, and a solution of the NF dispersant and softened water were added there. The dispersion was processed for 2-3 hours. Sulfur was weighed, loaded into a mill, and a weighed amount of ammonium caseinate solution, ammonia, and softened water were added there. The dispersion was processed (72±2) hours.

The pigment paste was introduced into the container with the mixture before washing the bath.

A latex mixture was prepared in the following ratio of components, wt. % :

Nitrile Butadiene Latex 93.392 Potassium hydroxide 0.013 Agidol 0.94 Casein 0.18 Ammonia water 0.005 Dispersant NF 0.13 Ethylcymate 2.67 zinc oxide 1.38 Sulfur 1.07 pigment paste 0.22

and left to mature.

Claims (2)

Composition for the manufacture of latex-based gloves containing potassium hydroxide, casein, aqueous ammonia, NF dispersant, zinc oxide, sulfur, characterized in that it additionally contains butadiene nitrile latex, agidol, ethylcymate and pigment paste in the following ratio, wt. %: Nitrile Butadiene Latex 93.392 Potassium hydroxide 0.013 Agidol 0.94 Casein 0.18 Ammonia water 0.005 Dispersant NF 0.13 Ethylcymate 2.67 zinc oxide 1.38 Sulfur 1.07 pigment paste 0.22