STABILIZED SLURRY COMPOSITIONS HAVING ENHANCED BARRIER PROPERTIES
Provided is a stabilized slurry composition having enhanced barrier properties. The slurry includes a pigment having a BET surface area of greater than 15 m 2 /g and a composite of a microcrystalline cellulose and carboxymethyl cellulose. The slurry can be used to formulate barrier coatings to be applied to the surface of a paper or paperboard product to enhance and improve the barrier properties of the product.
1 . A slurry composition comprising:
a pigment having a BET surface area of greater than 15 m 2 /g and an aspect ratio greater than 30; a microcrystalline cellulose gel; and
water.
2 . The slurry composition according to claim 1 , wherein the pigment comprises from about 40 wt. % to about 75 wt. %, or from about 50 wt. % to about 65 wt. % of the total weight of the slurry.
3 . The slurry composition according to claim 1 , wherein the pigment is chosen from talc, kaolin, bentonite, calcium carbonate, mica, and combinations thereof.
4 . The slurry composition according to claim 3 , wherein the pigment is a lamellar talc.
5 . The slurry composition according to claim 1 , wherein the microcrystalline cellulose gel is composite consisting of microcrystalline cellulose (MCC) and carboxymethyl cellulose.
6 . The slurry composition according to claim 5 , wherein the molar ratio of microcrystalline cellulose to carboxymethyl cellulose is from about 1:1 to about 1:4.
7 . The slurry composition according to claim 1 , further comprising one or more additives.
8 . The slurry composition according to claim 7 , wherein the additive is chosen from xanthan gum, sodium alginate, acrylates, and combinations thereof.
9 . The slurry composition according to claim 7 , wherein the additives comprise from about 0.5 wt. % to about 5 wt. % of the total weight of the slurry.
10 . The slurry composition according to claim 1 , wherein a slurry comprising from about 40 wt. % to about 75 wt. % pigment solids remains in suspension as determined visually after storage at 25° C. temperature for at least 60 days.
11 . The slurry composition according to claim 10 , wherein the slurry comprises about 50 wt. % pigment solids and remains in suspension as determined visually after storage at 25° C. temperature for at least 60 days.
12 . A process for the production of paper or board with improved barrier properties, said method comprising the steps of:
providing a paper or board product having a surface, and
applying a slurry composition comprising a pigment having a BET surface area of greater than 15 m 2 /g and an aspect ratio greater than 30; a microcrystalline cellulose gel; and a polymeric binder emulsion.
13 . The process according to claim 12 , wherein the pigment is chosen from talc, kaolin, bentonite, calcium carbonate, mica, and combinations thereof.
14 . The process according to claim 12 , wherein the pigment comprises from about 40 wt. % to about 75 wt. %, or from about 50 wt. % to about 65 wt. % of the total slurry composition.
15 . The process according to claim 12 , wherein the microcrystalline gel is a composite consisting of microcrystalline cellulose and carboxymethyl cellulose.
16 . The process according to claim 12 , wherein the polymeric binder emulsion can be chosen from styrene butadiene, styrene acrylate, polyethylene, polypropylene, polyethylene oxide, polyacrylate, polyvinyl alcohol, polyvinyl acetate, polyvinyl amine, and combinations thereof.
17 . The process according to claim 12 , wherein the slurry composition further comprises one or more additives.
18 . The process according to claim 12 , wherein the slurry composition is sheared for at least 10 minutes prior to being applied to the surface of the paper or board.
19 . The process according to claim 12 wherein the slurry composition is applied to the paper or paperboard via spraying, rotogravure, rod applicator, blade applicator, and curtain coating.
20 . The process according to claim 12 , wherein the paper or board having the slurry composition applied to its surface has improved liquid and vapor barrier properties of approximately 13% improvement using the 30 minute water cobb test when compared with paper or paper board without the slurry composition.