OPAQUE POLYESTER-BASED MATERIALS

Abstract

The invention discloses a preform for a container comprising a polyester, titanium dioxide, and a light absorbing additive. In addition, a process for preparing a polyester-based container from such a preform is disclosed, as well as a polyester-based container obtainable by such a process. The opaque containers can for instance be used for storing light-sensitive solids and/or liquids. The optical properties of the preform result in improved properties during blow-moulding processes.

Claims

1. A preform for a container, said preform comprising: a polyester, titanium dioxide, a light absorbing additive; wherein said preform has a transmittance at 550 nm of 0.1% or less and a transmittance at 1300 nm of 0.5% or more, wherein the transmittance is measured at 2 mm sample thickness.

2. A preform for a container, said preform comprising: a polyester, titanium dioxide, a light absorbing additive; wherein said preform has an absorption at 550 nm of 25% or more and an absorption at 1300 nm of 20% or less, wherein the absorption is measured at 2 mm sample thickness.

3. The preform for a container of claim 1, wherein the transmittance at 1300 nm of said preform is at least 0.5 percentage point more than the transmittance at 550 nm of said preform.

4. The preform for a container of claim 2, wherein the absorption at 1300 nm of said preform is at least 10 percentage point less than the absorption at 550 nm of said preform.

5. The preform for a container of claim 1, wherein the polyester comprises one or more selected from the group consisting of polyethylene terephthalate, virgin bottle grade polyethylene terephthalate, postconsumer polyethylene terephthalate, polyethylene terephthalate glycol-modified (PETG), polyethylene naphthalate, polybutylene terephthalate, polyethylene furanoate, and polylactic acid.

6. The preform for a container of claim 1, wherein the light absorbing additive comprises a pigment.

7. The preform for a container of claim 1, wherein the light absorbing additive comprises a dye.

8. The preform for a container of claim 1, wherein the light absorbing additive comprises one or more organic compounds selected from the group consisting of Solvent Yellow 43 (CAS number 19125-99-6/1226-96-9), Solvent Yellow 72 (CAS number 61813-98-7), Solvent Yellow 93 (CAS number 4702-90-3/61969-52-6), Solvent Yellow 114 (CAS number 75216-45-4), Disperse Yellow 64 (CAS number 10319-14-9), Disperse Yellow 201 (CAS number 80748-21-6), Disperse Yellow 241 (CAS number 83249-52-9), Solvent Violet 36 (CAS number 61951-89-1), Solvent Red 23 (CAS number 85-86-9), Solvent Red 26 (CAS number 477-79-6), Solvent Red 111 (CAS number 82-38-2), Solvent Red 135 (CAS number 71902-17-5), Solvent Red 149 (CAS number 71902-18-6/21295-57-8), Solvent Red 179 (CAS number 89106-94-5), Solvent Red 195 (CAS number 164251-88-1), Solvent Red 207 (CAS number 15958-68-6), Solvent Green 3 (CAS number 128-80-3), Solvent Green 28 (CAS number 71839-01-5), Disperse Blue 60 (CAS number 12217-80-0), Solvent Blue 36 (CAS number 14233-37-5), Solvent Blue 97 (CAS number 61969-44-6), Solvent Blue 101 (CAS number 6737-68-4), Solvent Blue 104 (CAS number 116-75-6), Solvent Orange 60 (CAS number 61969-47-9/6925-69-5), Disperse Orange 47 (CAS number 12236-03-2), Solvent Black 7 (CI number 50415:1, CAS number 8005-02-5), Pigment Blue 15:1 (CI number 74160, CAS number 147-14-8), Pigment Blue 15:3 (CI number 74160, CAS number 147-14-8), Pigment Green 7 (CI number 74260, CAS number 1328-53-6), Pigment Orange 43 (CI number 71105, CAS number 4424-06-0), Pigment Orange 64 (CI number 12760, CAS number 72102-84-2), Pigment Orange 72 (CI number 211095, CAS number 78245-94-0), Pigment Red 122 (CI number 73915, CAS number 980-26-7), Pigment Red 144 (CI number 20735, CAS number 5280-78-4), Pigment Red 149 (CI number 71137, CAS number 4948-15-6), Pigment Red 177 (CI number 65300, CAS number 4051-63-2), Pigment Red 178 (CI number 71155, CAS number 3049-71-6), Pigment Red 179 (CI number 71130, CAS number 5521-31-3), Pigment Red 187 (CI number 12486, CAS number 59487-23-9), Pigment Red 202 (CI number 73907, CAS number 3089-17-6), Pigment Red 214 (CI number 200660, CAS number 40618-31-3), Pigment Red 220 (CI number 20055, CAS number 68259-05-2), Pigment Red 242 (CI number 20067, CAS number 52238-92-3), Pigment Red 247 (CI number 15915, CAS number 43035-18-3), Pigment Red 254 (CI number 56110, CAS number 84632-65-5), Pigment Red 264 (CI number 561300, CAS number 88949-33-1), Pigment Violet 19 (CI number 73900, CAS number 1047-16-1), Pigment Violet 23 (CI number 51319, CAS number 6358-30-1), Pigment Violet 29 (CI number 71129, CAS number 81-33-3), Pigment Yellow 109 (CI number 56284, CAS number 5045-40-9), Pigment Yellow 110 (CI number 56280, CAS number 5590-18-1), Pigment Yellow 119 (CI number 77496, CAS number 68187-51-9), Pigment Yellow 128 (CI number 20037, CAS number 79953-85-8), Pigment Yellow 138 (CI number 56300, CAS number 30125-47-4), Pigment Yellow 147 (CI number 60645, CAS number 4118-16-5), Pigment Yellow 151 (CI number 13980, CAS number 31837-42-0), Pigment Yellow 180 (CI number 21290, CAS number 77804-81-0), Pigment Yellow 181 (CI number 11777, CAS number 74441-05-7), Pigment Yellow 183 (CI number 18792, CAS number 65212-77-3) Pigment Yellow 191 (CI number 18795, CAS number 129423-54-7), Pigment Yellow 53 (CI number 77788, CAS number 8007-18-9), Pigment Yellow 62 (CI number 13940, CAS number 12286-66-7), Pigment Yellow 95 (CI number 20034, CAS number 5280-80-8), and Pigment Blue 60 (CI number 69800, CAS number 81-77-6); and/or inorganic compounds selected from the group consisting of Pigment Black 26 (CI number 77494, CAS number 68186-94-7), Pigment Brown 24 (CI number 77310, CAS number 68186-90-3), Pigment Brown 29 (CI number 77500, CAS number 12737-27-8), Pigment Green 36 (CI number 74265, CAS number 14302-13-7), Pigment Green 50 (CI number 77377, CAS number 68186-85-6), Pigment Red 101 (CI number 77491, CAS number 1332-37-2), Pigment Black 28 (CI number 77428, CAS number 68186-91-4), Pigment Black 29 (CI number 77498, CAS number 68187-50-8), Pigment Black 30 (CI number 77504, CAS number 71631-15-7), Pigment Black 33 (CI number 77537, CAS number 68186-94-7 or 75864-23-2), Pigment Brown 29 (CI number 77500, CAS number 12737-27-8), Pigment Brown 33 (CI number 77503, CAS number 68186-88-9), Pigment Blue 29 (CI number 77007, CAS number 057455-37-5), Pigment Blue 28 (CI number 77346, CAS number 1345-16-0), Pigment Blue 36 (CI number 77343, CAS number 68187-11-1), Pigment Green 17 (CI number 77288, CAS number 1308-38-9), Pigment Yellow 164 (CI number 77899, CAS number 68412-38-4), Pigment Yellow 184 (CI number 771740, CAS number 14059-33-7), and Pigment Yellow 42 (CI number 77492, CAS number 51274-00-1), or oxides comprising metals or elements selected from the group consisting of Na, Al, Si, S, Zn, Ni, Fe, Mn, Ti, V, Bi, Co, Cr, Cu, Sn, and Sb.

9. The preform for a container of claim 1, further comprising polymethylpentene.

10. The preform for a container of claim 1, further comprising cyclic olefin polymer.

11. The preform for a container of claim 10, wherein the cyclic olefin polymer comprises one or more cyclic olefin copolymers.

12. The preform for a container of claim 10, wherein the cyclic olefin polymer comprises one or more cyclic olefin homopolymers.

13. The preform for a container of claim 10, wherein the cyclic olefin polymer comprises one or more selected from the group consisting of ethylene-norbornene copolymer, ethylene-phenyl norbornene copolymer, ethylene-tetracyclododecene norbornene copolymer, ethylene-dicyclopentadiene copolymer, norbornene homopolymer, phenyl norbornene homopolymer, tetracyclododecene norbornene homopolymer, and dicyclopentadiene homopolymer.

14. The preform for a container of claim 9, wherein the total amount of polymethylpentene and/or cyclic olefin polymer together is 5% or less, based on the total weight of the preform.

15. The preform for a container of claim 1, wherein the amount of titanium dioxide is 8% or less, based on the total weight of the preform.

16. The preform for a container of claim 1, comprising a layer, wherein the polyester, the titanium dioxide, the light absorbing additive, and the optional polymethylpentene and/or cyclic olefin polymer, are comprised in said layer.

17. A process for preparing a polyester-based container, said process comprising the steps of: heating the preform of claim 1 using a near-infrared (NIR) radiation source, and moulding the preform into a container.

18. The process of claim 17, wherein the preform is heated to 80-130° C.

19. The process of claim 17, wherein the preform is blow moulded into a container.

20. The process of claim 17, wherein the temperature difference between the outside of the preform, which faces the NIR radiation source, and the inside of the preform is 20° C. or less during said heating, wherein the temperature difference is measured on a preform of 3 mm thickness.

21. A polyester-based container obtainable by the process of claim 17.

22. The container of claim 21, having a transmittance at 550 nm of 1% or less, when measured at 0.25 mm sample thickness.

Description

EXAMPLES

Example 1

[0073] Concentrates with TiO.sub.2, PET carrier polymer and light absorbing additives were produced on a Kraus Maffei Berstorff ZE 25Rx46D twin screw extruder with a temperature profile of 270-280° C. Carrier resin content was typically 35%, whereas the combined content of TiO.sub.2 and light absorbing additives was typically 65%.

[0074] With the concentrates, plaques with dimensions 60 mm×53 mm×2 mm were prepared by adding 10 wt. % of the concentrate to polyester (Invista T94N PET resin, IV=0.84 dl/g), using an Arburg 221K Allrounder 350-100. The extruder temperature profile was set to 285° C. All plaques contained enough opacifier and light absorbing additive to have a transmittance value of zero between 300-700 nm. The transmittance curves from 300 to 1700 nm of the opaque plaques were collected using a Shimadzu UV3600 plus spectrometer equipped with an ISR 1503 integrating sphere and are plotted in FIG. 1. For comparison, natural PET was added to the graph, which spectrum is plotted on the secondary y-axis with transmittance values of 0-100%.

[0075] Table 1 shows the composition of the four plaques and transmittance values. Cleary can be seen that samples 3 and 4 have a higher transmittance at 1300 nm than sample 2, whereas the transmittance at 550 nm is zero for all three opaque samples.

TABLE-US-00001 TABLE 1 % T @ % T @ Sample Opacifier Light absorber 550 nm 1300 nm  1* Natural PET none 89 90  2* TiO.sub.2 iron oxide (IO) <0.01 0.01 3 TiO.sub.2 dye mix of SR 135, SG 3 <0.01 3.9 4 TiO.sub.2 PBk 30 <0.01 0.6 *= comparative

Example 2

[0076] Preforms for a container were made from the materials from Example 1. The concentrates were used to produce polyester (PET) preforms (Invista T94N resin, IV=0.84 dl/g). The 25 g preforms for 0.5 litre bottles with PCO neck finish were produced using an Arburg Allrounder 320, equipped with a Piovan T200 dryer and DB-60 control unit, with extruder temperature profile and hot runner temperatures set at 285° C. PET was dried to a dew point of −45° C. Dosing of the concentrates at 10 wt. % was done using a Movacolor MCBalance.

[0077] Preforms were heated on a Corpoplast LB01 using the same PET bottle blowing settings for all preforms. After heating, the preform was transported and instantly measured on a Thermoscan 3D from Blow Moulding Technologies to determine the inside and outside temperature of the heated preform. Table 2 shows the temperature difference between the inside and the outside of the preforms with a wall thickness of 3.0 mm, during heating using NIR radiation.

TABLE-US-00002 TABLE 2 Outside Inside Preform temperature temperature Δ T no. composition (° C.) (° C.) (° C.)  1* PET, TiO.sub.2, IO 120 94 26 2 PET, TiO.sub.2, dye mix 106 93 13 3 PET, TiO.sub.2, PBk30 112 92 20 *= comparative

Example 3

[0078] Concentrates with TiO.sub.2, polymethylpentene (PMP) carrier, polymer and light absorbing additives were produced on a Kraus Maffei Berstorff ZE 25Rx46D twin screw extruder with a temperature profile of 270-280° C. Carrier resin content was typically 35%, whereas the combined content of TiO.sub.2 and light absorbing additives was typically 65%.

[0079] With the concentrates, plaques with dimensions 60 mm×53 mm×2 mm were prepared by adding 6 wt. % the concentrate to polyester (Invista T94N PET resin, IV=0.84 dl/g) using an Arburg 221K Allrounder 350-100. The extruder temperature profile was set to 285° C. All plaques contained enough opacifier and light absorbing additive to have a transmittance value of zero between 300-700 nm. The transmittance curves from 300 to 1700 nm of the opaque plaques were collected using a Shimadzu UV3600 plus spectrometer equipped with an ISR 1503 integrating sphere and are plotted in FIG. 2. For comparison, natural PET was added to the graph, which spectrum is plotted on the secondary y-axis with transmittance values of 0-100%.

[0080] Table 3 shows the composition of the four plaques and transmittance values. Cleary can be seen that samples 6 and 7 have a higher transmittance at 1300 nm than sample 5, whereas the transmittance at 550 nm is zero for all three opaque samples.

TABLE-US-00003 TABLE 3 % T @ % T @ Sample Opacifier Light absorber 550 nm 1300 nm  1* Natural PET none 89 90  5* TiO.sub.2, PMP iron oxide (IO) <0.01 <0.01 6 TiO.sub.2, PMP dye mix of SR 135, SG 3 <0.01 6.3 7 TiO.sub.2, PMP PBk 30 <0.01 3.9 *= comparative

[0081] Containers with a wall thickness of 0.25 mm were prepared in the following manner: preforms with typically 6 wt. % of the concentrates were heated on a Corpoplast LB01 using the same PET bottle blowing settings for all preforms. FIG. 3 shows the transmittance curves from 300 to 1500 nm of the blown containers measured using a Shimadzu UV3600 plus equipped with an ISR 1503 integrating sphere. The resulting containers maintain low transmittance at 550 nm after blowing.

Example 4

[0082] Preforms with 6 wt. % of the concentrates for a container were made from the materials from Example 3. The concentrates were used to produce polyester (PET) preforms (Invista T94N resin, IV=0.84 dl/g). The 25 g preforms for 0.5 litre bottles with PCO neck finish were produced using an Arburg Allrounder 320, equipped with a Piovan T200 dryer and DB-60 control unit, with extruder temperature profile and hot runner temperatures set at 285° C. PET was dried to a dew point of −45° C. Dosing of the concentrates was done using a Movacolor MCBalance.

[0083] Preforms were heated on a Corpoplast LB01 using the same PET bottle blowing settings for all preforms. After heating, the preform was transported and instantly measured on a Thermoscan 3D from Blow Moulding Technologies to determine the inside and outside temperature of the heated preform. Table 4 shows the temperature difference between the inside and the outside of the preforms with a wall thickness of 3.0 mm, during heating using NIR radiation.

TABLE-US-00004 TABLE 4 Outside Inside Preform temperature temperature Δ T no. Composition (° C.) (° C.) (° C.)  1* PET, PMP, TiO.sub.2, IO 120 97 23 2 PET, PMP, TiO.sub.2, dye mix 98 88 10 3 PET, PMP, TiO.sub.2, PBk30 106 90 16 *= comparative

Example 5

[0084] Analogous to Examples 3-4, preforms with cyclic olefin polymer (COP) as opacifier were produced and measured on a Thermoscan 3D from Blow Moulding Technologies to determine the inside and outside temperature of the heated preform. Table 4 shows the temperature difference between the inside and the outside of the preforms with a wall thickness of 3.0 mm, during heating using NIR radiation.

TABLE-US-00005 TABLE 5 Outside Inside Preform temperature temperature Δ T no. Composition (° C.) (° C.) (° C.)  1* PET, COP, TiO.sub.2, IO 123 99 24 2 PET, COP, TiO.sub.2, dye mix 110 96 13 3 PET, COP, TiO.sub.2, PBk30 113 96 17 *= comparative

Example 6

[0085] Concentrates with TiO.sub.2, PET carrier polymer and light absorbing additives were produced on a Kraus Maffei Berstorff ZE 25Rx46D twin screw extruder with a temperature profile of 270-280° C. Carrier resin content was typically 40%.

[0086] With the concentrates, plaques with dimensions 60 mm×53 mm×2 mm were prepared by adding the concentrate to 8 gram polyester (Invista T94N PET resin, IV=0.84 dl/g), using an Arburg 221K Allrounder 350-100. The extruder temperature profile was set to 285° C. Transmittance curves from 300 to 1700 nm of the plaques were collected using a Shimadzu UV3600 plus spectrometer equipped with an ISR 1503 integrating sphere and are plotted in FIGS. 4 and 5.

[0087] Table 6 shows the composition of the seven plaques and transmittance values measured at 550 and 1300 nm. Cleary it can be seen that whereas comparative samples 12-14 all have a transmittance of <0.1% at 550 nm, none has a transmittance of 0.5% or more at 1300 nm.

TABLE-US-00006 TABLE 6 Opacifier % T @ % T @ Sample (wt. %) Light absorber (wt. %) 550 nm 1300 nm  8 TiO.sub.2 (4.76) iron oxide (0.031) <0.01 0.03  9 TiO.sub.2 (4.76) dyes (0.014) 0.01 6.8 10 TiO.sub.2 (7.5) iron oxide (0.049) <0.01 0.01 11 TiO.sub.2 (7.5) dyes (0.022) <0.01 2.8  12* TiO.sub.2 (7.5) carbon black (0.001) <0.01 0.2  13* TiO.sub.2 (10.5) carbon black (0.001) <0.01 0.05  14** TiO.sub.2 (4.76) carbon black (0.0086) <0.01 <0.01 *= comparative sample according to EP-B-1 970 181 **= comparative sample according to JP-B-3 112 086

Example 7

[0088] The concentrates in example 6 were used to produce polyester (PET) preforms (Invista T94N resin, IV=0.84 dl/g). 25 g preforms for 0.5 litre bottles with PCO neck finish were produced using an Arburg Allrounder 320, equipped with a Piovan T200 dryer and DB-60 control unit, with extruder temperature profile and hot runner temperatures set at 285° C. PET was dried to a dew point of −45° C. Dosing of the concentrates was done using a Movacolor MCBalance. Preforms were heated on a Corpoplast LB01 using the same PET bottle blowing settings for all preforms.

[0089] Transmittance curves from 300 to 1700 nm of the preforms with a thickness of 0.25 mm were collected using a Shimadzu UV3600 plus spectrometer equipped with an ISR 1503 integrating sphere and are plotted in FIGS. 6 and 7. Table 7 shows the transmittance values of the preforms at 550 and 1300 nm. Clearly it can be seen that comparative examples 12 and 13 have a transmittance of >0.1% at 550 nm. In view of comparative example 14, by using more carbon black the preform becomes more grey, is more difficult to blow mould, and has a weak transmittance at 1300 nm.

TABLE-US-00007 TABLE 7 Opacifier % T @ % T @ Sample (wt. %) Light absorber (wt. %) 550 nm 1300 nm  8 TiO.sub.2 (4.76) iron oxide (0.031) 0.8 17.9  9 TiO.sub.2 (4.76) dyes (0.014) 0.5 33.8 10 TiO.sub.2 (7.5) iron oxide (0.049) 0.04 6.5 11 TiO.sub.2 (7.5) dyes (0.022) 0.05 25.4  12* TiO.sub.2 (7.5) carbon black (0.001) 0.9 19.3  13* TiO.sub.2 (10.5) carbon black (0.001) 0.4 15.2  14** TiO.sub.2 (4.76) carbon black (0.0086) 0.04 11.4 *= comparative sample according to EP-B-1 970 181 **= comparative sample according to JP-B-3 112 086