Skinned substrates with highly crosslinked polyurethane layer

Patent metadata

Field	Value
Publication number	US-9517607-B2
Application number	US-201314410090-A
Country	US
Kind code	B2
Filing date	Jun 20, 2013
Priority date	Jun 27, 2012
Publication date	Dec 13, 2016
Grant date	Dec 13, 2016

Abstract

PVC-skinned composites include a substrate, a skin and an intermediate polyurethane layer. The polyurethane layer is characterized in having a low molecular weight between crosslinks, i.e., is somewhat highly crosslinked. The high level of crosslinking in the polyurethane leads to improved performance of the skin layer. The skin layer retains its original color upon aging, is less prone to shrinking and other loss of physical properties, and adheres better to the polyurethane layer.

First claim

What is claimed is:

1. A skinned composite comprising
a) a substrate,
b) an exterior plasticized polymeric skin having a thickness of 0.5 to 2 mm covering at least a portion of the substrate, the exterior plasticized polymer skin comprising a thermoplastic polymer and 25 to 45% by weight of a plasticizer based on the combined weight of the plasticizer and the thermoplastic polymer and further having one or more score lines on an exposed and/or an inner surface; and
c) a polyurethane layer interposed between the substrate and the plasticized polymeric skin, wherein the polyurethane layer is the reaction product of a reaction mixture that contains one or more polyisocyanates and one or more isocyanate-reactive compounds that contain two or more isocyanate-reactive groups, wherein the polyurethane has a calculated molecular weight per crosslink of no greater than 1250 as calculated by the formula

MW
xl

=

A
+
B

A
⁡

(

C
-
2

)

CD

+

B
⁡

(

F
-
2

)

EFG

+

B
⁡

(

F
-
1

)

⁢

(

1
-

1
E

)

(

E
+
1

)

⁢
G

wherein
A is the combined weight, in grams, of all isocyanate-reactive materials that contain at least 2 isocyanate-reactive groups/molecule, including any water, provided to the reaction mixture;
B is the combined weight, in grams, of all isocyanate compounds provided to the reaction mixture;
C is average functionality of all isocyanate-reactive compounds provided to the reaction mixture that contain at least 2 isocyanate-reactive groups/molecule, including any water;
D is the average equivalent weight in grams per hydroxyl group of all isocyanate-reactive compounds provided to the reaction mixture that contain at least 2 isocyanate-reactive groups/molecule, including any water;
E is the isocyanate index, calculated as the number of equivalents of isocyanate groups provided to the reaction mixture divided by the number of equivalents of isocyanate-reactive groups provided to the reaction mixture;
F is the average functionality of all isocyanate compounds provided to the reaction mixture; and
G is the average equivalent weight in grams per isocyanate group of all isocyanate compounds provided to the reaction mixture.

2. The skinned composite of claim 1 wherein the skin is a plasticized polymer of vinyl chloride.

3. The skinned composite of claim 1 , wherein the density of the polyurethane layer is from 48 to 480 kg/m 3 .

4. The skinned composite of claim 1 wherein the polyisocyanate(s) have an average functionality of at least 2.0 and an isocyanate equivalent weight of 85-200.

5. The skinned composite of claim 1 which exhibits a discoloration, after heating for 8 days at 120° C., characterized by a ΔE* value of 3 or less.

6. A method for preparing the skinned composite of claim 1 , comprising positioning the skin and the substrate within a mold to form a gap between the skin and the substrate, introducing the reaction mixture into the mold between the skin and the substrate and curing the reaction mixture in the mold between the skin and substrate.

7. A skinned composite comprising
a) a substrate,
b) an exterior plasticized polymeric skin having a thickness of 0.5 to 2 mm covering at least a portion of the substrate, the exterior plasticized polymer skin comprising a thermoplastic polymer and 25 to 45% by weight of a plasticizer based on the combined weight of the plasticizer and the thermoplastic polymer, and further having one or more score lines on an exposed and/or an inner surface; and
c) a polyurethane layer interposed between the substrate and the plasticized polymeric skin, wherein the polyurethane layer is the reaction product of a reaction mixture that contains one or more polyisocyanates and one or more isocyanate-reactive compounds that contain two or more isocyanate-reactive groups, wherein the reaction mixture has an isocyanate index of from 0.9 to 1.25 and the isocyanate-reactive compounds that contain two or more isocyanate-reactive groups are selected from the group consisting of:
1) a blend of a high functionality polyol having a hydroxyl functionality of at least 4, and a hydroxyl equivalent weight of 80 to 250 with at least one low equivalent weight polyol, aminoalcohol or polyamine that has an equivalent weight per isocyanate group of up to about 125, and a functionality of 3 to 4;
2) a blend of a high functionality polyol having a hydroxyl functionality of at least 4, and a hydroxyl equivalent weight of 80 to 250 with one or more high equivalent weight polyether polyols or polyether amines, the high equivalent weight polyol or polyether amine having a functionality of 2 to 3 and an equivalent weight of at least 350 to 2200;
3) a blend of a high functionality polyol having a hydroxyl functionality of at least 4, and a hydroxyl equivalent weight of 80 to 250 with at least one low equivalent weight polyol, aminoalcohol or polyamine that has an equivalent weight per isocyanate group of up to about 125and a functionality of 3 to 4 and one or more high equivalent weight polyols or polyether amines having a functionality of 2 to 3 and an equivalent weight of at least 350 to 2200;
4) a blend as in any of 1)-3), further including water; and
5) a blend as in any of 1)-4), further including one or more aliphatic polyesters having a hydroxyl functionality of at least 2 and a hydroxyl equivalent weight of about 350 to 1500 and which are a reaction product of an aliphatic dicarboxylic acid (or corresponding acid chloride or diester) with at least one polyol having at least 2 hydroxyl groups and a hydroxyl equivalent weight of 150 or less, or a mixtu

Assignees

• Dow Global Technologies Llc

Inventors

• Cavalca Sara
• Fregni Sabrina

Classifications

• C08G18/482

  Mixtures of polyethers containing at least one polyether containing nitrogen · CPC title

• B32B2266/0278

  Polyurethane · CPC title

• B32B27/304

  comprising vinyl halide (co)polymers, e.g. PVC, PVDC, PVF, PVDF · CPC title

• B32B27/302

  comprising aromatic vinyl (co)polymers, e.g. styrenic (co)polymers · CPC title

• B29K2105/04

  cellular or porous · CPC title