POLYMERIC MATERIALS

Abstract

A film for use in architectural applications (e.g. for roofs, walls or windows of buildings) comprises a polymeric material and an additive, wherein said polymeric material is a fluoropolymer and said additive is selected from titaniumnitride and tungsten oxide. Preferred polymeric materials may be ethylene chlorotrifluoroethylene (ECTFE) or an ethylene-tetrafluoroethylene copolymer (ETFE).

Claims

1. A film comprising a polymeric material (A) and an additive, wherein said polymeric material (A) is a fluoropolymer and said additive is selected from titanium nitride and tungsten oxide.

2. (canceled)

3. A film according to claim 1, wherein the ratio defined as the wt % of fluoropolymers in said film divided by the total wt % of all thermoplastic polymeric materials in said film is at least 0.95.

4. A film according to claim 1, wherein said film includes at least 0.05 wt %, and less than 3 wt % of said additive.

5. A film according to claim 1, wherein said polymeric material (A) includes a repeat unit which includes a moiety ##STR00009## wherein X is a fluorine atom.

6. (canceled)

7. A film according to claim 1, wherein said polymeric material (A) includes a structure ##STR00010## wherein X is a fluorine atom.

8. A film according to claim 5, wherein said polymeric material (A) includes at least 60 wt % of moieties of Formula III; and includes less than 90 wt % of moieties of Formula III.

9. A film according to claim 1, wherein said polymeric material (A) is an ethylene-tetrafluoroethylene copolymer.

10. A film according to claim 1, wherein said polymeric material (A) makes up at least 60 wt % of the total wt % of thermoplastic polymeric materials included in said film.

11. A film according to claim 1, wherein the sum of the wt % of all thermoplastic polymeric materials, titanium nitride and tungsten oxide in the film is at least 95 wt %.

12. A film according to claim 1, wherein said additive is titanium nitride and the sum of the wt % of polymeric material (A) and said titanium nitride in said film is at least 80 wt %, and said film includes at least 50 ppm of titanium nitride.

13. A film according to claim 1, wherein said additive is tungsten oxide and the sum of the wt % of polymeric material (A) and said tungsten oxide is at least 80 wt % and said film includes at least 250 ppm of tungsten oxide.

14. A film according to claim 1, wherein said additive is in the form of particles which are dispersed throughout said film and/or in said polymeric material (A), wherein said particles of said additive in said film have a d.sub.50 of less than 50 μm and greater than 10 nm measured by Laser Diffraction.

15. A film according to claim 1, wherein a size-ratio (SR) is defined as:
SR=thickness of the film (in μm)/Maximum dimension (in μm) of largest particle of said additive in said film wherein SR is at least 5 and is less than 100.

16. (canceled)

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18. A film according to claim 1, wherein said film is part of a building.

19. A method of making a film according to claim 1, the method comprising: (i) selecting a formulation (A) comprising an additive selected from titanium nitride and tungsten oxide, wherein said formulation (A) includes at least 1000 ppm of said additive, wherein said formulation (A) includes a polymeric material (C) which is a fluoropolymer and wherein said formulation (A) is a solid masterbatch; (ii) contacting said formulation (A) with a polymeric material (A) which is a fluoropolymer; and (iii) melt-processing said formulation (A) and polymeric material (A) to produce said film.

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29. A method of making a formulation (A) wherein said formulation (A) comprises an additive selected from titanium nitride and tungsten oxide, wherein said formulation (A) includes at least 1000 ppm of said additive, wherein said formulation (A) includes a polymeric material (C) which is a fluoropolymer and wherein said formulation (A) is a solid masterbatch, the method comprising: (i) selecting a liquid formulation (B) comprising a carrier and an additive selected from titanium nitride and tungsten oxide, wherein said liquid formulation (B) includes at least 10 wt % and less than 50 wt % of said additive and said liquid formulation (B) includes at least 50 wt % carrier and up to 90 wt % carrier, wherein said carrier has a boiling point of less than 330° C.; (ii) contacting said liquid formulation (B) with a polymeric material (C) which is a fluoropolymer; (iii) melt-processing said liquid formulation (B) with said polymeric material (C) wherein carrier is vented off during melt-processing and wherein said method comprises producing pellets comprising said polymeric material (C) and said additive.

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41. A film according to claim 1, wherein the ratio defined as the wt % of fluoropolymers in said film divided by the total wt % of all thermoplastic polymeric materials in said film is at least 0.95; wherein said film includes at least 0.2 wt %, of said additive and includes less than 3 wt % of said additive; wherein said polymeric material (A) is an ethylene-tetrafluoroethylene copolymer; wherein said polymeric material (A) makes up at least 85 wt % of the total wt % of thermoplastic polymeric materials included in said film; wherein the sum of the wt % of all thermoplastic polymeric materials, titanium nitride and tungsten oxide in the film is at least 99 wt %.

42. A film according to claim 41, wherein a size-ratio (SR) is defined as:
SR=thickness of the film (in μm)/maximum dimension (in μm) of largest particle of said additive in said film, wherein SR is at least 5 and is less than 100; and wherein said additive is in the form of particles which are dispersed throughout said film and/or in said polymeric material (A), wherein said particles of said additive in said film have a d.sub.50 of less than 50 μm and greater than 10 nm, measured by Laser Diffraction.

43. A film according to claim 41, wherein said film is part of a building, said additive is titanium nitride and the sum of the wt % of polymeric material (A) and said titanium nitride in said film is at least 80 wt %, and said film includes at least 500 ppm of titanium nitride.

44. A film according to claim 41, wherein said film is part of a building, said additive is tungsten oxide and the sum of the wt % of polymeric material (A) and said tungsten oxide is at least 80 wt % and said film includes at least 500 ppm tungsten oxide.

Description

EXAMPLE 1—PREPARATION OF LIQUID FORMULATION COMPRISING TITANIUM NITRIDE

[0114] Titanium nitride (15 wt %) as described was slowly added with constant stirring to ethylene glycol (85 wt %). After the solid titanium nitride had been added, the mixer speed was increased to produce a smooth vortex and the speed of the mixer was maintained at the increased level until the solids had been fully dispersed. The dispersion was then transferred to a bead mill and milled until the titanium nitride had been milled to the desired particle size and agglomerates had been broken down.

[0115] The particle size; measured by transmission electron microscopy (TEM) was 20 nm.

EXAMPLE 2—PREPARATION OF LIQUID FORMULATION COMPRISING TUNGSTEN OXIDE

[0116] Milled Tungsten oxide (40 wt %) of particle size less than 2 μm as described was slowly added with constant stirring as described in Example 1 to ethylene glycol (60 wt %) and the solids were fully dispersed as described in Example 1. The particle size, measured by Laser Diffraction was <2 μm.

EXAMPLE 3—PREPARATION OF MASTERBATCH COMPRISING TITANIUM NITRIDE

[0117] The liquid formulation of Example 1 (1.28 wt %) was blended with a mixture of dry polymer pellets of ETFE 6235 and C88AXMB powder to produce polymer/liquid IR absorber pre-mix.

[0118] The blended composition was fed into a twin-screw extruder to melt the ETFE polymer and disperse particles of titanium nitride in the polymer matrix. Additionally, in the extruder, the ethylene glycol is vented off. On exit from the extruder, the composition is cooled and pelletised.

[0119] The pelletised blend was characterised using MFI and Lab* colour values and results are provided in Table 1. For comparison purposes, Example C1 quoted in Table 1 is ETFE6235 in the absence of titanium nitride.

TABLE-US-00001 TABLE 1 Characteristic Example C1 Example 3 Example 4 MFI - 5 kg/297° C. 10 9.48 10.24 L* 96.82 35.08 31.65 a* 0.07 −2.89 −11.95 b* 1.28 −11.61 −0.91

[0120] From the colour data, it can be seen that the addition of the titanium nitride in the masterbatch makes the masterbatch much darker than the original resin. In the case of the MFI, it remains relatively unaffected by the addition of the liquid IR absorber additive indicating that the carrier liquid is not acting as a plasticiser and does not affect the rheology of the polymer, indicating successful removal of the liquid component.

EXAMPLE 4—PREPARATION OF MASTERBATCH COMPRISING TUNGSTEN OXIDE

[0121] The procedure of Example 3 was generally followed by blending ETFE6235 (87.27 wt %), C88AXMB Ashai beads (9.18 wt %) and the liquid formulation of Example 2 (3.55 wt %). The output of the extruder was pelletized and the pelletised blend characterised as described in Example 3. Results are recorded in Table 1. As for Example 3, oxide in the masterbatch makes the masterbatch darker compared to the original resin, but the MFI is substantially unaffected indicating that the carrier liquid has not plasticised the polymer or otherwise affected its rheology.

EXAMPLES 5 TO 10—PREPARATION OF FILMS COMPRISING MASTERBATCHES OF EXAMPLES 3 AND 4

[0122] The masterbatches of Examples 3 and 4 were mixed with ETFE6235 polymer in various proportions and extruded using a single screw extruder fitted with a film die to produce films of 200 μm thickness.

[0123] A summary of the components used to make the films is provided in Table 2. All amounts in the table are wt %.

TABLE-US-00002 TABLE 2 Example Example Example Example Example Example Example C1 5 6 7 8 9 10 ETFE6235 100 95 90 85 95 90 85 Example 3 —  5 10 15 — — — Example 4 — — — —  5 10 15

EXAMPLE 11—ASSESSMENT OF FILMS

[0124] The films produced (examples 5-10) were measured for transmittance using a UV-VIS-NIR spectrophotometer and the percentage reduction in IR transmittance measured at 700, 800, 900 and 1000 nm to illustrate the reduction (%) in IR transmittance (i.e. IR absorption). The colours of the films produced was also measured and is reported as Lab* values (L*, a*, b* and ΔE* compared to example C1). Results are provided in Table 3.

TABLE-US-00003 TABLE 3 Example 700 800 900 1000 No. nm nm nm nm L* a* b* ΔE* C1 N/A N/A N/A N/A 96.82 0.07 1.28 N/A 5 23.27 21.10 16.14  8.74 90.23 −0.03 1.51 6.59 6 29.91 28.46 24.23 17.40 87.94 −0.36 0.72 8.9 7 38.47 37.28 33.68 27.52 84.23 −0.68 0.03 12.68 8 31.06 33.47 33.49 30.45 88.95 −1.39 1.9 8.03 9 45.18 48.40 51.61 50.76 83.7 −2.62 2.14 13.42 10 52.38 55.47 59.49 59.05 81.97 −2.82 1.98 15.14

[0125] In comparison to the un-modified polymer materials (Example C5), it can be seen that by adding increasing quantities of the masterbatch Example 3 (i.e. Examples 5-7) that there is a reduction in the IR transmittance at the designated wavelengths and that this IR absorption effect increases as the quantity of the masterbatch of Example 3 is increased. Conversely as the IR absorbing effect increases the material does become darker but the transparency of the film is retained. Examples 8-10 based on the addition of the 5-7 with the exception that the IR absorbing effect is increased. Example 8-10 do become darker as the proportion of masterbatch of Example 4 is added but again the material transparency is retained.

[0126] Thus, advantageously, use of the masterbatches described, allows films to be produced which, when used on the outside of buildings (e.g. as parts of roofs or walls), allow significant visible light transmission into the building whilst limiting IR transmission into the building.

[0127] The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.