Continuous Process for the Production of Moisture-Cure, Polyurethane Sealants and Adhesives

• US 20090198036A1
• Filed: 12/24/2008
• Published: 08/06/2009
• Est. Priority Date: 12/28/2007
• Status: Active Grant

• Current Assignee: Bostik Incorporated (Totalenergies Se)
• Original Assignee: Bostik Incorporated (Totalenergies Se)
• Inventors: Duffy, Sean G.
• Granted Patent: US 8,734,609 B2
• Time in Patent Office: Days
• US Class Current: 528/85
• CPC Class Codes: B29B 7/007 for continuous mixing
• CPC Class Codes: B29B 7/325 Static mixers in general B01F25/42
• CPC Class Codes: B29B 7/48 with intermeshing devices, e.g. screws
• CPC Class Codes: B29B 7/603 in measured doses, e.g. proportioning of several materials
• CPC Class Codes: B29B 7/7461 Combinations of dissimilar mixers
• CPC Class Codes: B29B 7/748 Plants B29B7/7433, B29B7/7485, B29B7/7495 take precedence
• CPC Class Codes: B29B 7/7485 with consecutive mixers, e.g. with premixing some of the components
• CPC Class Codes: B29B 7/845 Venting, degassing or removing evaporated components in devices with rotary stirrers
• CPC Class Codes: B29B 7/94 Liquid charges
• CPC Class Codes: B29C 48/08 flexible, e.g. films
• CPC Class Codes: B29C 48/29 in liquid form
• CPC Class Codes: B29C 48/297 at several locations, e.g. using several hoppers or using a separate additive feeding
• CPC Class Codes: B29C 48/365 using pumps, e.g. piston pumps
• CPC Class Codes: B29C 48/39 a first extruder feeding the melt into an intermediate location of a second extruder
• CPC Class Codes: B29C 48/40 using two or more parallel screws or at least two parallel non-intermeshing screws, e.g. twin screw extruders
• CPC Class Codes: B29C 48/57 provided with kneading disc-like elements, e.g. with oval-shaped elements
• CPC Class Codes: B29C 48/767 through a degassing opening of a barrel
• CPC Class Codes: B29K 2075/00 Use of PU, i.e. polyureas or polyurethanes or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2105/0005 containing compounding ingredients releasing, lubricating or separating agents B29C33/56, fibers B29K2105/08, B29K2105/12; fillers B29K2105/16, recycled material B29K2105/26
• CPC Class Codes: C08G 18/0895 Manufacture of polymers by continuous processes C08G18/0838 takes precedence
• CPC Class Codes: C08G 18/10 : Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
• CPC Class Codes: C08G 18/307 : Atmospheric humidity
• CPC Class Codes: C08G 18/48 : Polyethers
• CPC Class Codes: C08G 2190/00 : Compositions for sealing or packing joints

Abstract

A process for continuous manufacturing of moisture-curable polyurethane formulations used as sealants and adhesives. The process is characterized by the fact that the reactive components are introduced independently, and without the need for a prepolymer, to a mixer. Solid or liquid raw materials can be either pre-blended or fed directly to the mixer, a twin-screw extruder, which provides the requisite energy to homogenously mix the raw materials and drive the chemical reaction. The process is designed so that the extruder barrel and screw allow variable feed addition and heat exchange down the length of the machine. This allows various operations to be performed at different points in the extruder, including reaction, dispersive mixing, distributive mixing and devolitization.

Claims

1. A process for the continuous manufacturing of polyurethanes comprising the following steps:

feeding a polyol to an upstream section of a twin-screw extruder;

feeding an isocyanate to the upstream section of said twin-screw extruder; and

mixing said polyol and said isocyanate in the upstream section of said twin-screw extruder to homogenize the polyol and isocyanate and drive the polyurethane reaction and form a polyurethane product.

2. The process of claim 1 comprising applying a vacuum at one or more locations of the extruder to remove unwanted gaseous components from the product.

3. The process of claim 1 comprising adding a catalyst to said twin-screw extruder directly after the polyol and isocyanate to accelerate the reaction in the upstream section of the extruder.

4. The process of claim 1 comprising adding one or more solid ingredients to said twin-screw extruder after the polyol and isocyanate.

5. The process of claim 1 comprising controlling the steps of feeding the polyol and feeding the isocyanate by utilizing a pump downstream of the extruder.

6. The process of claim 1 comprising removing any unwanted gases from the product by utilizing a thin-film evaporator downstream of the extruder.

7. The process of claim 1 comprising adding pigment to the product by utilizing a static mixer downstream of said twin-screw extruder.

8. The process of claim 1 comprising adding catalyst to the product by utilizing a static mixer downstream of said twin-screw extruder to uniformly mix catalyst into the polyurethane product.

9. The process of claim 1 comprising simultaneously adding catalyst and pigment to the product by utilizing a static mixer downstream of said twin-screw extruder to uniformly mix a preblend of pigment and catalyst into the polyurethane product.

10. A sealant made by the continuous process of claim 1.

11. An adhesive made by the continuous process of claim 1.