A composite board comprising inorganic and/or cellulosic materials and a latex composition as a binder, said composite board having dimensional stability and strength

Claim 2

A latex composition, useful as a binder for inorganic and cellulosic materials to form a composite, comprising an aqueous dispersion of copolymer particles, the copolymer composition being such that the copolymer has a T g whereby the resulting composite has sufficient strength for necessary handling and use and maintains dimensional stability with increased temperature and humidity.

Claim 3

A latex composition, useful as a binder for inorganic and cellulosic materials to form a composite, comprising an aqueous dispersion of copolymer particles, the copolymer composition being such that the copolymer has a T g whereby the resulting composite (a) maintains dimensional stability with increased temperature and humidity and (b) has a modulus of rupture of at least about 130 psi (0.9 MPa) or at least 140 psi (0.96 MPa) as measured by ASTM 367-­78.

Claim 4

A latex composition, useful as a binder for inorganic and cellulosic materials to form a composite, comprising an aqueous dispersion of copolymer particles, the copolymer composition being such that the copolymer has a T g whereby the resulting composite (a) maintains dimensional stability with increased temperature and humidity and (b) has a modulus of rupture of at least about 130 psi (0.9 MPa) or at least 140 psi (0.96 MPa) as measured by ASTM 367-­78.

Claim 5

A composition as claimed in Claim 1 or 2 wherein the copolymer has (1) a T g of at least 35°C, (2) a T g of from 35°C to 115°C, or (3) a T g of from 50°C to 110°C.

Claim 6

A composition as claimed in any one of the preceding claims wherein the copolymer comprises (1) a monovinylidene monomer and an aliphatic conjugated diene, (2) a monovinylidene monomer, an aliphatic conjugated diene monomer and an α,β-ethylenically unsaturated monomer, (3) a monovinylidene monomer and an ester of an ethylenically unsaturated carboxylic acid, (4) a monovinylidene monomer, an ester of the ethylenically unsaturated carboxylic acid and an α,β-­ethylenically unsaturated carboxylic acid, (5) styrene and ethyl acrylate, (6) two or more esters of an ethylenically unsaturated carboxylic acid, (7) two or more esters of an ethylenically unsaturated carboxylic acid selected from the group consisting of methyl methacrylate and butyl acrylate, or ethyl acrylate and butyl acrylate, (8) styrene, butadiene and fumaric acid, or (9) styrene and butadiene.

Claim 7

A composition as claimed in any one of the preceding claims wherein the copolymer comprises a hard monomer having, as a homopolymer a T g of at least 80°C, and a soft monomer having, as a homopolymer a T g of less than 35°C.

Claim 8

A composition of Claim 5 wherein the hard monomer is present in an amount of from 50 to 99 weight percent and the soft monomer is present in an amount of from 1 to 50 weight percent.

Claim 9

A composite board comprising inorganic or cellulosic materials or both inorganic and cellulosic materials and a latex binder comprising a copolymer with a T g such that the resulting ceiling board maintains dimensional stability with increased temperature and humidity, and the resulting ceiling board has a modulus of rupture of at least 130 psi (0.9 MPa) as measured by ASTM 367-78.

Claim 10

A composite board comprising inorganic or cellulosic materials or both inorganic and cellulosic materials and a latex binder comprising a copolymer with a T g such that the resulting ceiling board maintains dimensional stability with increased temperature and humidity, and the resulting ceiling board has a modulus of rupture of at least 130 psi (0.9 MPa) as measured by ASTM 367-78.

Claim 11

A composite board as claimed in Claim 7 wherein the latex binder comprises (1) a monovinylidene monomer, an aliphatic conjugated diene monomer and an α,β-ethylenically unsaturated carboxylic acid, (2) methyl methacrylate, ethyl acrylate and fumaric acid, (3) a copolymer of styrene and butadiene (4) a copolymer of styrene and one or more esters of ethylenically unsaturated carboxylic acid selected from the group consisting of methyl methacrylate, ethyl acrylate and butyl acrylate, or (5) a polymer of styrene, ethyl acrylate and acrylic acid.

Claim 12

A process for preparing a latex composition useful as a binder for inorganic and cellulosic materials to form a composite which comprises emulsion polymerizing an aqueous mixture of: (1) a hard monomer having a T g of at least 80°C and a soft monomer having a T g of less than 35°C. (2) a monovinylidene monomer and an aliphatic conjugated diene, (3) a monovinylidene monomer, an aliphatic conjugated diene monomer and a α,β-ethylenically unsaturated monomer, or (4) a monovinylidene monomer, an ester of an ethylenically unsaturated carboxylic acid and an α,β-­ethylenically unsaturated carboxylic acid.

Claim 13

A process for preparing a latex composition useful as a binder for inorganic and cellulosic materials to form a composite which comprises emulsion polymerizing an aqueous mixture of: (1) a hard monomer having a T g of at least 80°C and a soft monomer having a T g of less than 35°C. (2) a monovinylidene monomer and an aliphatic conjugated diene, (3) a monovinylidene monomer, an aliphatic conjugated diene monomer and a α,β-ethylenically unsaturated monomer, or (4) a monovinylidene monomer, an ester of an ethylenically unsaturated carboxylic acid and an α,β-­ethylenically unsaturated carboxylic acid.

Claim 14

A process for preparing a composite board which comprises (1) providing a dispersion of inorganic or cellulosic materials or a mixture of inorganic and cellulosic materials, (2) adding to the dispersion a latex composition as claimed in any one of Claims 1 to 6 and a flocculant, (3) pouring the resulting furnish into a mold and (4) diluting and draining the furnish.