Oxygen Barrier Plastic Material

Abstract

The invention relates to use of an additive as oxygen barrier in a plastic material wherein (a) the plastic material is a polyolefin, a polyolefin copolymer or a polystyrene, and the additive is (b) and optionally (c): (b) a compound of formula (I);

##STR00001## wherein Ra represents C.sub.7-C.sub.20 alkyl, C.sub.6-C.sub.10 aryl, C.sub.4-C.sub.10 heteroaryl, wherein the heteroatoms are N, O and/or S, (C.sub.2-C.sub.6)-alkenylen-(C.sub.6-C.sub.10) aryl, C.sub.1-C.sub.6-alkylen-C.sub.6-C.sub.10-aryl, the aryl and heteroaryl radicals optionally being substituted by: hydroxyl, C.sub.1-C.sub.6-alkyl, C.sub.1-C.sub.6 alkoxyl, C.sub.6-C.sub.10 aryloxy, halogen, cyano, nitro, C.sub.6-C.sub.10-aryl, di(C.sub.1-C.sub.6)alkylamino, (C.sub.1-C.sub.6)alkylthio, C.sub.6-C.sub.10-arylthio, O, S, SO.sub.3H, SO.sub.2NR.sup.1R.sup.2, CO.sub.2R.sup.3, CONR.sup.1R.sup.2, NHCOR.sup.4, COC.sub.6-C.sub.10-aryl or a combination thereof, wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4 are the same or different and independently represent hydrogen or Rb represents a group selected from the moieties of formula (II), (III), (IV), (V), (VI) and (VII);

##STR00002## wherein each Rc can be the same or different and independently represents hydrogen, C.sub.1-C.sub.20 alkyl or C.sub.6-C.sub.10-aryl, (C.sub.2-C.sub.4) alkenylen (C.sub.6-C.sub.10) aryl, C.sub.1-C.sub.4-alkylen-C.sub.6-C.sub.10-aryl, the aryl radicals optionally being substituted by hydroxyl, C.sub.1-C.sub.4-alkyl, C.sub.1-C.sub.4 alkoxyl, C.sub.6-C.sub.10 aryloxy, Cl, cyano, C.sub.6-C.sub.10-aryl, or COC.sub.6-C.sub.10-aryl; Rd represents hydrogen, C.sub.1-30 alkyl, C.sub.6-C.sub.10-aryl or halogen; Re represents hydrogen, C.sub.1-30 alkyl, C.sub.6-C.sub.10-aryl or a halogen and can be on ortho (o) or meta (m) position to Rd; X can be O or NRf where Rf represents hydrogen, C.sub.1-C.sub.20 alkyl or phenyl; Y can be O or S; n is a number from 1 to 30; (c) a transition metal catalyst.

Claims

1. A process for producing an additive as oxygen barrier in a plastic material comprising the step of mixing components (a), (b) and optionally (c) wherein (a) the plastic material is a polyolefin, a polyolefin copolymer or a polystyrene, and the additive is (b) wherein: (b) is a compound of formula (I); ##STR00011## wherein Ra is C.sub.7-C.sub.20 alkyl, C.sub.6-C.sub.10 aryl, C.sub.4-C.sub.10 heteroaryl, wherein the heteroatoms are N, O and/or S, (C.sub.2-C.sub.6)-alkenylen-(C.sub.6-C.sub.10) aryl, C.sub.1-C.sub.6-alkylen-C.sub.6-C.sub.10-aryl, the aryl and heteroaryl radicals optionally being substituted by: hydroxyl, C.sub.1-C.sub.6-alkyl, C.sub.1-C.sub.6 alkoxyl, C.sub.6-C.sub.10 aryloxy, halogen, cyano, nitro, C.sub.6-C.sub.10-aryl, di(C.sub.1-C.sub.6)alkylamino, (C.sub.1-C.sub.6)alkylthio, C.sub.6-C.sub.10-arylthio, O, S, SO.sub.3H, SO.sub.2NR.sup.1R.sup.2, CO.sub.2R.sup.3, CONR.sup.1R.sup.2, NHCOR.sup.4, COC.sub.6-C.sub.10-aryl or a combination thereof, wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4 are the same or different and independently are hydrogen or C.sub.1-C.sub.6-alkyl; Rb is a moiety selected from the group consisting of formula (II), (III), (IV), (V), (VI) and (VII); ##STR00012## wherein each Rc is the same or different and independently is hydrogen, C.sub.1-C.sub.20 alkyl or C.sub.6-C.sub.10-aryl, (C.sub.2-C.sub.4) alkenylen (C.sub.6-C.sub.10) aryl, C.sub.1-C.sub.4-alkylen-C.sub.6-C.sub.10-aryl, the aryl radicals optionally being substituted by hydroxyl, C.sub.1-C.sub.4-alkyl, C.sub.1-C.sub.4 alkoxyl, C.sub.6-C.sub.10 aryloxy, Cl, cyano, C.sub.6-C.sub.10-aryl, or COC.sub.6-C.sub.10-aryl; Rd is hydrogen, C.sub.1-30 alkyl, C.sub.6-C.sub.10-aryl or halogen; Re is hydrogen, C.sub.1-30 alkyl, C.sub.6-C.sub.10-aryl or a halogen and is on ortho (o) or meta (m) position to Rd; X is O or NRf where Rf represents hydrogen, C.sub.1-C.sub.20 alkyl or phenyl; Y is O or S; n is a number from 1 to 30; (c) is a transition metal catalyst.

2. The process as claimed in claim 1, wherein the compound (b) is used in an amount of from 0.05 to 5% by weight, based on the total weight of the plastic material and the components.

3. The process as claimed in claim 1, wherein the transition metal catalyst c) is used in an amount of from 0 to 1% by weight, based on the total weight of the plastic material and the components.

4. A composition Z comprising the components A, B, and optionally C, the component A being a plastic material selected from the group consisting of polyolefins, polyolefin copolymers and polystyrenes; the component B being an additive selected from the group consisting of formula (I); ##STR00013## wherein Ra is C.sub.7-C.sub.20 alkyl, C.sub.6-C.sub.10 aryl, C.sub.4-C.sub.10 heteroaryl, wherein the heteroatoms are N, O and/or S, (C.sub.2-C.sub.6)-alkenylen-(C.sub.6-C.sub.10) aryl, C.sub.1-C.sub.6-alkylen-C.sub.6-C.sub.10-aryl, the aryl and heteroaryl radicals optionally being substituted by: hydroxyl, C.sub.1-C.sub.5-alkyl, C.sub.1-C.sub.6 alkoxyl, C.sub.6-C.sub.10 aryloxy, halogen, cyano, nitro, C.sub.6-C.sub.10-aryl, di(C.sub.1-C.sub.6)alkylamino, (C.sub.1-C.sub.6)alkylthio, C.sub.6-C.sub.10-arylthio, O, S, SO.sub.3H, SO.sub.2NR.sup.1R.sup.2, CO.sub.2R.sup.3, CONR.sup.1R.sup.2, NHCOR.sup.4, COC.sub.6-C.sub.10-aryl or a combination thereof, wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4 are the same or different and independently are hydrogen or C.sub.1-C.sub.6-alkyl; Rb is a moiety selected from the group consisting of formula (II), (III), (IV), (V), (VI) and (VII); ##STR00014## wherein each Rc is the same or different and independently are hydrogen, C.sub.1-C.sub.20 alkyl or C.sub.6-C.sub.10-aryl, (C.sub.2-C.sub.4) alkenylen (C.sub.6-C.sub.10) aryl, C.sub.1-C.sub.4-alkylen-C.sub.6-C.sub.10-aryl, the aryl radicals optionally being substituted by hydroxyl, C.sub.1-C.sub.4-alkyl, C.sub.1-C.sub.4 alkoxyl, C.sub.6-C.sub.10 aryloxy, Cl, cyano, C.sub.6-C.sub.10-aryl, or COC.sub.6-C.sub.10-aryl; Rd is hydrogen, C.sub.1-30 alkyl, C.sub.6-C.sub.10-aryl or halogen; Re is hydrogen, C.sub.1-30 alkyl, C.sub.6-C.sub.10-aryl or a halogen and is on ortho (o) or meta (m) position to Rd; X is O or NRf where Rf is hydrogen, C.sub.1-C.sub.20 alkyl or phenyl; Y is O or S; n is a number from 1 to 30; the component C being a transition metal catalyst.

5. The composition as claimed in claim 4, wherein compounds of formula (I) are of the formula (VIII), (IX) and (X) ##STR00015## wherein Rb, Rc, Y and X are as defined in claim 4.

6. The composition as claimed in claim 4, wherein component B is a compound of formula (XI) ##STR00016## wherein Rd is hydrogen or C.sub.1-30 alkyl, C.sub.6-C.sub.10-aryl or a halogen; Re is hydrogen or C.sub.1-30 alkyl, C.sub.6-C.sub.10 aryl or a halogen and is on ortho (o) or meta (m) position to Rd.

7. The composition as claimed in claim 4, wherein the component B is N-benzylbenzamide (formula (XII)). ##STR00017##

8. The composition as claimed in claim 4, wherein in component C the metal is iron, nickel, manganese, cobalt or copper.

9. The composition as claimed in claim 4, wherein component C is cobalt oleate, cobalt propionate, cobalt stearate, or cobalt neodecanoate.

10. The composition as claimed in claim 4, further comprising a component D selected from the group consisting of colorants, fillers, acid scavengers, processing aids, coupling agents, lubricants, blowing agents, polyhydric alcohols, nucleating agents, antioxidants, antistatic agents, UV absorbers, slip agents, anti-fogging agents, anti-condensation agents, suspension stabilizers, anti-blocking agents, waxes, and a mixture thereof.

11. The composition as claimed in claim 4, TABLE-US-00010 of from 14 to 99.99 % by weight of component A; of from 0.01 to 70 % by weight of component B; of from 0 to 15 % by weight of component C; of from 0 to 80 % by weight of component D; with the % by weight being based in each case on the total weight of the composition Z; and with the weight percent of the components A, B, optionally C and optionally D always adding up to 100%, wherein component D is selected from the group consisting of colorants, fillers, acid scavengers, processing aids, coupling agents, lubricants, blowing agents, polyhydric alcohols, nucleating agents, antioxidants, antistatic agents, UV absorbers, slip agents, anti-fogging agents, anti-condensation agents, suspension stabilizers, anti-blocking agents, waxes, and a mixture thereof.

12. The composition as claimed in claim 4, wherein the composition Z is in the form of a masterbatch comprising TABLE-US-00011 of from 14 to 95 % by weight of component A; of from 5 to 70 % by weight of component B; of from 0 to 15 % by weight of component C; of from 0 to 80 % by weight of component D; with the % by weight being based in each case on the total weight of the composition Z; and with the weight percent of the components A, B, optionally C and optionally D always adding up to 100%, wherein component D is selected from the group consisting of colorants, fillers, acid scavengers, processing aids, coupling agents, lubricants, blowing agents, polyhydric alcohols, nucleating agents, antioxidants, antistatic agents, UV absorbers, slip agents, anti-fogging agents, anti-condensation agents, suspension stabilizers, anti-blocking agents, waxes, and a mixture thereof.

13. The composition as claimed in claim 4, wherein the composition Z is in the form of a compound comprising TABLE-US-00012 of from 88 to 99.9 % by weight of component A; of from 0.1 to 1.5 % by weight of component B; of from 0 to 0.5 % by weight of component C; of from 0 to 10 % by weight of component D; with the % by weight being based in each case on the total weight of the composition Z; and with the weight percent of the components A, B, optionally C and optionally D always adding up to 100%, wherein component D is selected from the group consisting of colorants, fillers, acid scavengers, processing aids, coupling agents, lubricants, blowing agents, polyhydric alcohols, nucleating agents, antioxidants, antistatic agents, UV absorbers, slip agents, anti-fogging agents, anti-condensation agents, suspension stabilizers, anti-blocking agents, waxes, and a mixture thereof.

14. A method for the manufacture of a composition Z as claimed in claim 4, comprising the step of physically mixing the components A, B, optionally C, and optionally D, %, wherein component D is selected from the group consisting of colorants, fillers, acid scavengers, processing aids, coupling agents, lubricants, blowing agents, polyhydric alcohols, nucleating agents, antioxidants, antistatic agents, UV absorbers, slip agents, anti-fogging agents, anti-condensation agents, suspension stabilizers, anti-blocking agents, waxes, and a mixture thereof.

15. A formed plastic article comprising the composition Z as claimed in claim 4.

Description

EXAMPLES

[0145] % by weight mentioned in the following examples are based on the total weight of the mixture, composition or article; parts are parts by weight;

[0146] ex means example; cpex means comparative example; MB means masterbatch; CO means compound; unless indicated otherwise.

[0147] Substances Used

[0148] Component A1:

[0149] Low Density Polyethylene (LDPE) powder: LDPE Riblene, M.F.I. 2 g/10 min 190 C. 2.16 Kg; density 0.925 g/cm.sup.3 (ASTM D3236-88).

[0150] Component B1:

##STR00010##

[0151] Component C1:

[0152] Cobalt stearate (9.5% Cobalt concentration).

[0153] Component D1:

[0154] Anhydrous Sodium Sulfite, CAS. 7757-83-7

[0155] Component D2:

[0156] Calcitec, calcium carbonate powder, particle size 99%<10 m.

[0157] Masterbatches MB1 to MB3

[0158] The components were homogenized together on a Leistritz ZSE18HP extruder at the temperature of 140 C. to obtain solid masterbatches MB1 to MB3; Table 1 gives the details.

TABLE-US-00006 TABLE 1 Components used [parts] Masterbatches A1 B1 C1 D1 D2 MB1 90 10 MB2 95 5 MB3 45 50 5

[0159] ex1, ex2 and cpex1 to cpex2:

[0160] Component A1 and the other components were mixed and homogenized in the ratios according to Table 2. The obtained Compounds CO1 to CO4 were used to manufacture 50 m monolayer films on a film blowing machine LabTech Scientific. As an example of operational mode, components A1, MB1, MB2 or MB3 were inserted through a hopper applied to the main stream of a LabTech Scientific Blow Extruder (model Lab25; 25 mm screw diameter 1:30 ratio) while internal temperature was kept between 190 and 195 C.; blown films were then collected from the unit for the necessary testing.

[0161] The oxygen barrier performance corresponding to the films prepared with compounds CO1 to CO4 was then measured by following the methods described above. Table 4 gives the details.

[0162] CO1 consists of a composition formulated with virgin LDPE resin.

[0163] CO4 consists of a sodium sulfite based composition not comprising component B1.

TABLE-US-00007 TABLE 2 Components used [parts] ex-cpex Compounds A1 MB1 MB2 MB3 cpex 1 CO1 100 (virgin LDPE) ex1 CO2 95 5 ex2 CO3 94 5 1 cpex2 CO4 94 6

[0164] Total haze is the preferred method of measuring the clarity of POs articles, which can determine their suitability for packaging applications requiring high levels of transparency. Haze was measured on PO films obtained from compounds CO1 to CO4 as described above. Table 3 gives the details.

[0165] Composition CO2 and CO3 of the present invention clearly show a significant improvement in clarity compared to the state-of-the-art composition CO4 not comprising component B. The level of clarity of the inventive compositions is very similar to virgin LDPE, as in CO1.

TABLE-US-00008 TABLE 3 Compounds Haze (%) CO1 1.5 CO2 1.9 CO3 1.8 CO4 8

[0166] In table 4, the ingress of oxygen (in ppm) measured for compositions CO1 to CO4 is reported against the time elapsed (measured in days) from the moment the cell is hermetically sealed leaving inside an oxygen-free atmosphere. Difference between subsequent measurements is reported as Delta values, and the speed of ingress per day in the same period is reported as m, according to the formula

Delta=m.Math.days

[0167] For every composition the measurements have been interrupted when one of following conditions were met: end of the interesting period of desired shelf life (196 days), or oxygen content higher than 2.0 ppm (close to the upper accuracy limit of the measurement system).

TABLE-US-00009 TABLE 4 Compounds Time CO1 CO2 CO3 CO4 [days] ppm Delta m ppm Delta m ppm Delta m ppm Delta m 0 0 0 0 0 28 7.30 7.3 0.26 1.72 1.72 0.061 0.68 0.68 0.02 3.36 3.36 0.12 35 10.20 2.9 0.41 1.68 0.04 0.06 0.67 0.01 0.001 2.90 0.46 0.07 49 1.69 0.01 0.0007 0.67 0 0 2.59 0.31 0.02 86 1.54 0.15 0.004 0.63 0.04 0.001 2.41 0.18 0.005 118 1.77 0.23 0.007 0.71 0.08 0.002 196 1.94 0.17 0.002 0.83 0.12 0.0015