POLYMER-BASED FOAM COMPOSITIONS COMPRISING INORGANIC PARTICULATE FILLERS

Abstract

There is disclosed a polymer-based foam composition comprising a polymer and up to 20 wt.-% 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 up to 20 wt.-% particles of one or more inorganic particulate materials, based on the total weight of the composition; wherein the one or more Inorganic particulate materials comprises less than 20 wt.-% Al, calculated as Al.sub.2O.sub.3-content.

2. A polymer-based foam wherein the one or more Inorganic particulate materials comprise greater than 0 wt.-% Al.

3. A polymer-based foam according to claim 1, wherein the said inorganic particulate material is a phyllosilicate.

5. A polymer-based foam according to claim 1, comprising a polymer-based foam film having a thickness ranging from 1 to 850 m.

8. A polymer-based foam according to claim 1, wherein the one or more phyllosilicates further comprise one or more of talc, kaolin, mica, chlorite and/or pyrophyllite.

7. A polymer-based foam according to claim 2, wherein the one or more phyllosilicates comprise aluminium in an amount ranging from greater than 0 to 50 wt.-%, all values calculated as Al.sub.2O.sub.3-content.

8. A polymer-based foam according to claim 1, wherein the polymer is a thermoplastic, a thermoplastic elastomer, or a rubber.

9. A polymer-based foam according to claim 6, wherein the thermoplastic is a polyolefin.

10. A polymer-based foam composition according to claim 1, wherein the polymer is the major component of the composition.

11. A polymer-based foam according to claim 1, wherein the talc has surface BET area of 1 to 200 m.sup.2.Math.g.sup.1.

12. A polymer-based foam according to claim 1 having an average cell size of =600 m or less in either the vertical direction (.sub.VD), or the width direction (.sub.Wd) or both.

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

14. A polymer-based foam according to claim 1 containing N.sub.f=10,000 or more cells per cm.sup.3.

15. A polymer-based foam according to claim 1 any previous claim produced by an extrusion process.

16. A polymer-based foam according to claim 1 produced by a blown film process.

17. A method of manufacturing a good, the method comprising incorporating 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.

18. A method of formation of a polymer-based foam composition as defined in claim 1, comprising: a) providing a polymer composition; b) providing particles of one or more inorganic materials; c) introducing the particles of one or more inorganic materials into the polymer composition in a blown film process; and d) foaming the polymer composition using a gas such as CO.sub.2, nitrogen or a noble gas.

Description

EXAMPLES

[0062] Tests and analytical results of filled polyethylene foams and films according to the present invention are described herein. 100 m 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.

[0063] 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.

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

[0064] The phyllosilicate according to Inventive Example 2 has a BET surface area of 6.5 m.sup.2g.sup.1 and a d.sub.50-median diameter of 3.7 m. The Al-containing phyllosilicate according to the Comparative Example has a d.sub.50-median diameter of 5.8 m.

[0065] The phyllosilicate of Inventive Example 1 was phyllosilicate comprising about 1 wt.-% aluminium, calculated as Al.sub.2O.sub.3-content.

[0066] The properties of the polyethylene films obtained under the same conditions, and using the different phyllosilicates as listed above are shown in Table II.

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 (m) 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

[0067] 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.