Paper mats

• US 5,156,718 A
• Filed: 01/18/1991
• Issued: 10/20/1992
• Est. Priority Date: 11/03/1989
• Status: Expired due to Fees

• Current Assignee: Gencorp Incorporated
• Original Assignee: Gencorp Incorporated
• Inventors: Neubert, Terry C.
• Primary Examiner(s): Chin, Peter
• Application Number:
  US07/643,391
• Time in Patent Office: 641 Days
• Field of Search: 162/145, 162/146, 162/168.1, 162/168.2, 162/168.3, 162/158, 162/169, 162/160, 162/168.4, 162/168.6, 162/168.7, 162/181.6, 162/181.8
• US Class Current: 162/145
• CPC Class Codes: D21H 17/43 Carboxyl groups or derivatives thereof

Abstract

A paper mat is made from an aqueous slurry or dispersion of kraft wood pulp, a large amount of finely divided inorganic pigments and as a binder an anionic latex of a copolymer of at least one conjugated diene monomer, at least one vinyl substituted aromatic monomer, at least one acrylic-type monomer and at least one monomer having a vinyl group and an activatable methyl, ethyl, propyl or butyl ester group. The mat of this invention exhibits improved properties over mats made from other latex binders.

Claims

1. The method which comprises forming an aqueous slurry to make a mat comprising on a dry weight basis from about, in parts by weight:

space="preserve" listing-type="tabular">______________________________________ 5.0 to 20.0 kraft wood pulp 0.5 to 3.0 polyethylene particles 60.0 to 85.0 finely divided clay or talc 1.0 to 2.0 chopped glass fibers 0.1 to 0.0015 antioxidant 0.01 to 0.02 water clarifier, and 8.0 to 16.0 copolymer binder (from an anionic latex) ______________________________________

forming a sheet on a screen from the slurry, removing water from the slurry using the screen to form a sheet, compressing the sheet and drying and cooling the sheet to form a paper mat wherein the latex of the copolymer binder has a solids content of from about 40 to 60% and wherein the copolymers of the latex comprises;

(a) from about 30 to about 60% by weight of at least one conjugated diene monomer selected from the group consisting of butadiene-1,3, isoprene, piperylene, 2,3-dimethyl-1,3-butadiene, pentadiene and hexadiene.

(b) from about 36 to 66% by weight of at least one vinyl substituted aromatic monomer selected from the group consisting of styrene, alpha methyl styrene, para methyl styrene, methyl vinyl toluene, p-vinyl toluene and 3-ethylstyrene.

(c) from about 1 to 4% by weight of at least one acrylic type monomer selected from the group consisting of acrylamide, methacrylamide, itaconic acid, acrylic acid and methacrylic acid.

(d) from about 3 to 6% by weight of at least one monomer having a vinyl group and an activatable methyl, ethyl, propyl or butyl ester group, and selected from the group consisting of methyl acrylamidoglycolate, ethyl acrylamidoglycolate, butyl acrylamidoglycolate, methyl acrylamidoglycolate methyl ether, butyl acrylamidoglycolate butyl ether, methyl methacrylaoxyacetate, ethyl acrylamido-N-oxalate (N-ethyloxalyl acrylamide), N, N'"'"'-Bis (ethyloxalyl) acrylamide, N-isopropyl, N-ethyloxalyl-3-propylamino methacrylamide, N-ethyloxalyl-N'"'"'-methyleneaminoacrylamide, ethyl N-2-ethyloxamatoacrylate, ethyl 3-pyruvylacrylate, ethyl methylenepyruvate, methyl acrylthiocarbonyl-oxyacetate (methyl thiacryloxyacetate), methyl thiacrylthioglylcolate, methyl acryl-2-thioglycolate, methyl acryl-2-thioglycolate, methyl thiacrylamidoacetate, methyl acrylamidoglycolate thioether, methyl acrylamido-N-methylenethioglycolate and p-ethyl oxalyl styrene.

2. The method according to claim 2, wherein said conjugated diene monomer is butadiene-1,3-where said vinyl substituted aromatic monomer is styrene, where said acrylic-type monomer is a mixture of itaconic acid and acrylamide and where the monomer having a vinyl group and an activatable vinyl, ethyl, propyl or butyl ester group is methylacrylamidoglycolate methyl ether.

3. The product produced by the method of claim 2.

4. A paper mat comprising about, in a dry weight basis, in parts by weight:

space="preserve" listing-type="tabular">______________________________________ 5.0 to 20.0 kraft wood pulp 0.5 to 3.0 polyethylene particles 60.0 to 85.0 finely divided clay or talc 1.0 to 2.0 chopped glass fibers 0.0 to 0.0015 antioxidant 0.01 to 0.02 water clarifier, and 8.0 to 16.0 copolymer binder from an anionic latex having a solids content of from about 40 to 60% by weight ______________________________________

wherein the copolymer comprises

(a) from about 30 to 60% by weight of at least one conjugated diene selected from group consisting of butadiene-1,3, isoprene, piperylene, 2,3-dimethyl-1,3-butadiene, pentadiene and hexadiene,

(b) from about 36 to 66% by weight of at least one vinyl substituted aromatic monomer selected from the group consisting of styrene, alpha methyl styrene, para methyl styrene, methyl vinyl toluene, p-vinyl toluene and 3-ethyl stryene,

(c) from about 1 to 4% by weight of at least one acrylic type monomer selected from the group consisting of acrylamide, methylacrylamide, itaconic acid, acrylic acid and methacrylic acid,

(d) from about 3 to 6% by weight of at least one monomer having a vinyl group and an activatable methyl, ethyl, propyl or butyl group and selected from the group consisting of;

methyl acrylamidoglycolate

ethyl acrylamidoglycolate

butyl acrylamidoglycolate

methyl acrylamidoglycolate methyl ether

butyl acrylamidoglycolate butyl ether

methyl methacrylaxyacetate

ethyl acrylamido-N-oxalate (N-ethyloxalyl acrylamide)

N-N'"'"'-Bis(ethyloxalyl)acrylamide

ethyl N-2-ethyloxamatoacrylate

ethyl 3-pyruvylacrylate

methyl acrylthiocarbonyloxyacetate (Methyl thia-cryloxyacetate)

methyl thiacrylthiogylcolate

methyl acryl-2-thioglycolate

methyl thiacrylamidoacetate

methyl acrylamidoglycolate thioether

methyl acrylamido-N-methylenethioglycolate, and p-ethyl oxalyl styrene.