Polymer-based foam compositions comprising inorganic particulate fillers

Abstract

There is disclosed a polymer-based foam composition comprising a polymer and up to 20 M.-% particles of one or more inorganic particulate materials, based on the total weight of the composition, wherein the one or more inorganic particulate materials comprise less than 20 wt.-% Al, calculated as Al.sub.2O.sub.3-content. According to one aspect, the one or more inorganic particulate materials comprise phyllosilicates. Also part of the present invention is the use of such polymer-based foam compositions and their method of production.

Claims

1. A polymer-based foam composition comprising a polymer; and from 1 to 20 wt.-% inorganic particulate materials, based on the total weight of the polymer-based foam composition; wherein the inorganic particulate materials comprise chlorite and at least one phyllosilicate selected from mica, talc, kaolin, and combinations thereof; wherein the inorganic particulate materials comprise from 1 wt.-% Al to 10 wt.-% Al; and wherein the inorganic particulate materials have a d.sub.50 from 3 to 4.5 microns.

2. A polymer-based foam composition comprising inorganic particulate materials that comprise chlorite and at least one phyllosilicate selected from mica, talc, kaolin and combinations thereof; wherein the inorganic particulate materials comprise from 1 wt.-% Al to 10 wt.-% Al; the polymer-based foam composition contains N.sub.f=100,000 or more cells per cm.sup.3; and the inorganic particulate materials have a d.sub.50 from 3 to 4.5 microns.

3. The polymer-based foam composition according to claim 1, wherein the polymer-based foam composition comprises a polymer-based foam film having a thickness ranging from 1 to 850 μm.

4. The polymer-based foam composition according to claim 1, wherein the polymer is a thermoplastic polymer or a rubber.

5. The polymer-based foam composition according to claim 4, wherein the thermoplastic polymer is a polyolefin.

6. The polymer-based foam composition according to claim 1, wherein the polymer is present in a greater weight amount than any other component of the polymer-based foam composition.

7. The polymer-based foam composition according to claim 1 having an average cell size of φ=600 μm or less in either the vertical direction (φ.sub.VD), or the width direction (φ.sub.WD) or both.

8. The polymer-based foam composition according to claim 1 having a ratio φ.sub.VD/φ.sub.WD of the average cell size in a vertical direction φ.sub.VD to the average cell size in a width direction φ.sub.WD of 1 or more.

9. The polymer-based foam composition according to claim 1 containing N.sub.f=100,000 or more cells per cm.sup.3.

10. The polymer-based foam composition according to claim 1 produced by an extrusion process.

11. The polymer-based foam composition according to claim 1 produced by a blown film process.

12. A method of manufacturing a good, the method comprising incorporating the polymer-based foam composition of claim 1 in the good, wherein the good comprises packaging, a food packaging product, a plastic part for automotive vehicles, or a thermal and/or noise insulation foam, pipe, consumer good or appliance.

13. A method of formation of the polymer-based foam composition as defined in claim 1, comprising: a) providing a polymer composition; b) providing the inorganic particulate materials; c) introducing the inorganic particulate materials into the polymer composition in a blown film process; and d) foaming the polymer composition using a gas.

14. The method of claim 13, wherein the gas is CO.sub.2, nitrogen, or a noble gas.

Description

EXAMPLES

(1) Tests and analytical results of filled polyethylene foams and films according to the present invention are described herein. 100 μm films were obtained through blown film extrusion of a low-density polyethylene (LDPE) formulation containing 5 wt.-% phyllosilicates, as described hereinabove. The process was carried out with a throughput of about 8 kg/h and an N2-pressure of about 90 bar.

(2) In order to test the performance of various phyllosilicate compositions of varying Al-content, the following tests were performed. The compositions used as nucleating agents are listed in Table I.

(3) TABLE-US-00001 TABLE I List of phyllosilicates used in the Examples Number Phyllosilicate Inventive Example 1 phyllosilicate having 1 wt.-% Al Inventive Example 2 Talc having less than 0.5 wt.-% Al Comp. Ex. phyllosilicate having 20 wt.-% Al

(4) The phyllosilicate according to Inventive Example 2 has a BET surface area of 6.5 m.sup.2×g.sup.−1 and a d.sub.50-median diameter of 3.7 μm. The Al-containing phyllosilicate according to the Comparative Example has a d.sub.50-median diameter of 5.8 μm.

(5) The phyllosilicate of Inventive Example 1 was phyllosilicate comprising about 1 wt.-% aluminium, calculated as Al.sub.2O.sub.3-content.

(6) The properties of the polyethylene films obtained under the same conditions, and using the different phyllosilicates as listed above are shown in Table II.

(7) TABLE-US-00002 TABLE II Properties of films obtained foam cell density Density average foam cell Number (cells × cm.sup.−3) (g × cm.sup.−3) diameter (μm) Inventive Example 1 4.44 × 10.sup.5 0.45 130.3 Inventive Example 2 4.34 × 10.sup.5 0.51 125.3 Comparative Example 7.98 × 10.sup.4 0.51 221.2

(8) It can be seen from the Inventive Examples 1 and 2, when compared to the Comparative Example, that the properties obtained according to the present invention are improved, compared to when 20 wt.-% Al-containing phyllosilicate is employed.