Continuous process for forming a unitary mat

Patent metadata

Field	Value
Publication number	US-10201911-B2
Application number	US-201515502441-A
Country	US
Kind code	B2
Filing date	Aug 5, 2015
Priority date	Aug 8, 2014
Publication date	Feb 12, 2019
Grant date	Feb 12, 2019

Abstract

A continuous process forms a unitary mat on a line having at least two conveyors spaced from each other. The process includes combining the isocyanate, an isocyanate catalyst, and a plurality of lignocellulosic particles to form a mixture and a self-polymerization product of the isocyanate in-situ in the mixture. The process also includes forming the unitary mat from the mixture on a first conveyer and transferring the unitary mat from the first conveyor to a second conveyor across a predetermined distance while maintaining structural integrity of the unitary mat. The lignocellulosic particles have a moisture content of 0.5 to 30 weight percent of water. Moreover, the continuous process is free of a step of adding water to the isocyanate, the isocyanate catalyst, the lignocellulosic particles, and/or the unitary mat.

First claim

What is claimed is:

1. A continuous process for forming unitary mats on a line having at least two conveyors spaced from each other, said process comprising the steps of:
A. combining an isocyanate, an isocyanate catalyst, triethyl phosphate, and a plurality of lignocellulosic particles to form a mixture and a self-polymerization product of the isocyanate in-situ in the mixture;
B. forming one of the unitary mats from the mixture on a first conveyer;
C. transferring the unitary mat from the first conveyor to a second conveyor across a distance while maintaining structural integrity of the unitary mat; and
D. continuously forming the unitary mats by steps (A)-(C) on said line having at least two conveyors,
wherein the lignocellulosic particles have a moisture content of 0.5 to 30 weight percent of water, and
wherein said continuous process is free of a step of adding water to the isocyanate or the isocyanate catalyst.

2. The continuous process of claim 1 wherein the at least two conveyors are spaced apart from each other by the predetermined distance of from 5 to 20 cm.

3. The continuous process of claim 1 wherein the isocyanate is polymeric methylene-4,4′-diphenyl diisocyanate.

4. The continuous process of claim 1 wherein the isocyanate catalyst is present in a carrier polyol.

5. The continuous process of claim 4 wherein the carrier polyol has a weight average molecular weight of from 50 to 2000 g/mol and is optionally a polyether polyol.

6. The continuous process of claim 1 wherein the mixture further comprises a polyurethane, polyurea, or combinations thereof.

7. The continuous process of claim 1 wherein the mixture comprises less than 1 weight percent of water.

8. The continuous process of claim 1 wherein the plurality of lignocellulosic particles comprises 0.5 to 20 weight percent of water.

9. The continuous process of claim 1 wherein the step of combining occurs at a temperature of from 140° F. to 180° F.

10. The continuous process of claim 1 wherein the step of forming the mat occurs at a temperature of from 325° F. to 375° F. such that a thermoset polyurethane and/or polyurea is formed.

11. The continuous process of claim 1 wherein the mixture comprises a reactive intermediate of an isocyanate polymerization reaction formed in-situ prior to the step of forming the mat.

12. The continuous process of claim 1 wherein the mixture comprises a biuret of polymeric methylene-4,4′-diphenyl diisocyanate during said step of forming the mat from the mixture.

13. The continuous process of claim 1 wherein the mixture is free of a formaldehyde resin.

14. The continuous process of claim 1 wherein the mixture is free of a tackifying compound and/or adhesive, different from the isocyanate and/or the self-polymerization product of the isocyanate.

15. A unitary mat having a length and width and comprising:
a plurality of lignocellulosic particles;
a self-polymerization product of an isocyanate; and
triethyl phosphate;
wherein said plurality of lignocellulosic particles has a moisture content of 0.5 to 30 weight percent of water; and
wherein said mat is free of a tackifying agent and/or adhesive different from said self-polymerization product of said isocyanate.

16. The unitary mat of claim 15 that maintains structural integrity when transferred from a first conveyor to a second conveyor across a distance during a continuous process of forming.

17. The unitary mat of claim 15 that is free of a formaldehyde resin and/or a reaction product of a formaldehyde resin and an isocyanate.

Assignees

• Basf Se

Inventors

• Kumar Rajesh
• Lawson Eric N

Classifications

• C08K5/526

  with hydroxyaryl compounds · CPC title

• B27N3/00

  Manufacture of substantially flat articles, e.g. boards, from particles or fibres · CPC title

• C08G18/10

  Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step · CPC title

• C08G18/7671

  containing only one alkylene bisphenyl group · CPC title

• C08G18/0895

  Manufacture of polymers by continuous processes (C08G18/0838 takes precedence) · CPC title