TRACEABLE COMPOSITE POLYMERS AND PREPARATION METHODS THEREOF FOR PROVIDING TRANSPARENCY IN PRODUCTION VALUE CHAINS

Abstract

The present invention is in the field of polymers comprising identifiable tracers by spectroscopic methods such as XRF, IR, NIR and XRD allowing information to be encoded by the polymers, and in particular polymers for conservation, restoration and retouching in artworks, electronics, coatings, plastics, packaging, 3D printing, rubber, and the like.

Claims

1. A polymer having one or more functionalities associated with at least one XRF-detectable metal ion, the polymer being grafted with at least one additional polymer.

2. The polymer according to claim 1, wherein the polymer is selected from fluoropolymers, phenolic resins, polyanhydrides, polyketones, polyesters, polyolefins, vinyl polymers, acrylics, polybenzimidazole, polycarbonate, polystyrene and polyvinyl chloride.

3. The polymer according to claim 1, wherein the polymer is selected from polystyrenes; polycarbonates; polyamides; polyacrylates; polyurethanes; and epoxy polymers.

4. The polymer according to claim 1, wherein the one or more functionality is an acrylate.

5. The polymer according to claim 1, wherein the one or more functionality is selected from an amine, a hydroxyl, a carboxylic acid and a thiol.

6. The polymer according to claim 1, wherein the metal ion is selected from Na, K, Ba, Ca, Mg, Ni, Al, Cr, Co, Cu, Hf, Fe, Pb, Sn, Zn, Ti, Zr, Y, Se, Nb, Sr, Mn, Mo, V Bi and La.

7. The polymer according to claim 1, wherein the at least one additional polymer is selected from thermoplastic polymers, elastomers, polyolefines, plastics, and rubber.

8. The polymer according to claim 1, wherein the at least one additional polymer is selected from polyethylene glycol, polyethylene, polypropylene, acrylonitrile butadiene styrene (ABS), polystyrene, high impact polystyrene, polycarbonate and rubber.

9. The polymer according to claim 1, selected from maleic anhydride grafted polypropylene (-MAH-g-PP) polymers.

10. The polymer according to claim 1, selected from PAA450NaY-MAH-g-PP, PAA450Ner-MAH-g-PP, PAA450NaMo-MAH-g-PP, PAA450KY-MAH-g-PP, PAA450KZr-MAH-g-PP, PAA450KMo-MAH-g-PP, PAA6NaY-MAH-g-PP, PAA6Na7r-MAH-g-PP and PAA6NaMo-MAH-g-PP.

11. A composition comprising a polymer according to claim 1.

12. The composition according to claim 11, being a master batch.

13. The composition according to claim 11, being in a form of a pellet.

14. A composite comprising a polymer according to claim 1.

15. A method of marking an object to be authenticated, the method comprising forming a film or a mark on at least a region of said object, said mark being in the form of a composite according to claim 14.

16. A method of authenticating an object having been marked with a composite material according to claim 14, the method comprising directing a primary electromagnetic signal to the material and detecting and analyzing a (secondary) response signal from the material.

17. The method according to claim 16, the method comprising directing an X-ray signal in the direction of the material and measuring an X-ray response signal.

18. An object comprising a polymer according to claim 1.

19. The object according to claim 18, wherein the object is a packaging material, a textile, an electronic object, an ink composition, a master batch or a rubber-based product.

20. A packaging material comprising a polymer according to claim 1.

21. (canceled)

Description

DETAILED DESCRIPTION OF EMBODIMENTS

Methods of Preparation

[0077] Methods of preparing the polymeric composite material of the present invention (described below) include reaction between polymers and tracer carrying monomers (for example, metal modified monomers). By using both polymers and monomers one may easily obtain the traceable polymeric composite material of the present invention essentially having the main properties of the parent polymer. For example, one may use the B72 polymer as the parent polymer and obtain a traceable or a code-carrying modified B72 polymer which keeps the basic properties of original B72 polymer (e.g. adhesiveness, transparency, flexibility, solvability, etc). Furthermore, by controlling the reaction of the parent B72 with the tracer carrying monomers (e.g. by controlling concentration of the monomers or other agents used in the process and/or the conditions of the process), the resulting modified B72 may enhance or suppress some of the original properties according the required application. For instance, one may use the modified B72 for anti-counterfeit and authentication-verification purposes wherein the modified B72 may be less solvable the parent B72.

(i) Wet Chemistry

[0078] The traceable composite polymer of the present invention may be formed by using tracer carrying monomer and a parent polymer dissolved in a solvent, in the presence of a radical initiator.

(ii) Reactive Extrusion

[0079] The traceable composite polymer of the present invention may be prepared by using a reactive extruder wherein polymerization is achieved without the use of solvents.

Polymeric Compositions of the Invention

[0080] Compositions of the invention were prepared using any one of the polymers listed in Table 1 below. In the Table, M is Nb, Mo, Y or Zr derived from salts such as from NbCl.sub.5, MoCl.sub.5, YCl.sub.3, NbCl.sub.5 (used as hydrate molecules).

TABLE-US-00001 TABLE 1 PAA450 Polyacrylic acid powder with a Mw = 450 K PAA450Na Sodium modified polyacrylic acid powder with a Mw = 450 K PAA450K Potassium modified polyacrylic acid powder with a Mw = 450 K PAA450NaM PAA450Na complexed with a heavy metal PAA450KM PAA450K complexed with a heavy metal PAA6Na Polyacrylic sodium salt powder with a Mw = 6 K (used as reference) PAA6NaM Polyacrylic sodium salt powder with a Mw = 6 K complexed with a heavy metal (used as reference)

Preparation of Sodium/Potassium Salt PAA450

[0081] Option A: in DI-Water

[0082] 10 g PAA450 were mixed with dilute NaOH (0.05N) until the solution became alkaline and kept for 24 h. The functionalized polymer was collected by filtration, washed with water to remove excess NaOH and dried in vacuum.

[0083] 10 g PAA450 were mixed with dilute KOH (0.05N) until the solution became alkaline and kept for 24 h. The functionalized polymer was collected by filtration, washed with water to remove excess NaOH and dried in vacuum.

[0084] Option B: in Ethanol

[0085] 5.1 g of KOH/NaOH were added into 100 ml ethyl alcohol (purity 95%) in a glass bottle and mechanically stirred to reach full dissolution. Then, 10 g of PAA450 were added into the solution with constant stirring for 9 hours at room temperature. After 9 hours of mixing, the product was filtrated and washed with water to remove excess of KOH/NaOH and dried at 50° C. overnight.

[0086] Option C: in Iso Propyl Alcohol (IPA)/DI-Water (95:5) Mixture

[0087] As ethanol is known to have negative environmental effects, IPA was used as an alternative. However, since PAA is not soluble in IPA, different IPA:water compositions were tested to dissolve both PAA and KOH/NaOH. 95:5 wt % IPA: water was found to dissolve PAA and KOH, but not NaOH.

[0088] Thus, 5.1 g of KOH were added into 100 ml IPA/water solution in a glass bottle and mechanically stirred to reach full dissolution. Then, 10 g of PAA450 were slowly added into the KOH solution with constant stirring until full dissolution. The solution was stirred for 9 hours at room temperature. The product was allowed to sit for 24 hrs under to hood, for IPA/water evaporation, then 100 cc DI-water were added to remove excess unreacted KOH. The product was then dried in an oven at 50° C. overnight.

Complexation with Metal Ions

[0089] Metal salts, such as metal chlorides were used for their water solubility (YCl.sub.3, MoCL.sub.5, ZrOCl.sub.2).

[0090] 100 mg PAA6Na were stirred with a definite excess concentration of metal salt solution under natural pH (0.05 N, 50 ml) for 9 h. The product (PAA6NaM) was collected by filtration and washed with excess distilled water to remove un-complexed metal ions.

[0091] 100 mg PAA450Na was stirred with a definite excess concentration of metal salt solution at its natural pH (0.05 N, 50 ml) for 9 h. The product (PAA450NaM) was collected by filtration and washed with excess distilled water to remove un-complexed metal ions.

[0092] 100 mg PAA450K was stirred with a definite excess concentration of metal salt solution at its natural pH (0.05 N, 50 ml) for 9 h. The product (PAA450KM) was collected by filtration and washed with excess distilled water to remove un-complexed metal ions.

[0093] All the above experiments were repeated at different pH values (ranging from 3 to about 6-7).

[0094] In the IR spectrum of the PAA450, asymmetric (C—O).sub.2 stretching of the carboxylate group COOH absorbed strongly near 1698 cm.sup.−1. On the contrary, PAA450Na exhibited a small absorption near 1698 cm.sup.−1 indicating presence of a small amount of COOH groups. A new asymmetric (C—O).sub.2 stretching peak with high absorption was observed near 1539 cm.sup.−1, indicating new COONa bonds. Upon coordination with the metal Y, the (C—O).sub.2 stretching frequency was shifted down from 1539 cm.sup.−1, for COONa, to 1531 cm.sup.−1, indicating complexation with metal Y ions (COOY bond). To calculate the reaction yield, the following equation was used:

[00001]$\mathrm{complexation}\%=\frac{{\left(A_{\mathrm{COOH}}/A_{C-H}\right)}_{PAA450}-{\left(A_{\mathrm{COOH}}/A_{C-H}\right)}_{PAA450M}}{{\left(A_{\mathrm{COOH}}/A_{C-H}\right)}_{PAA450}}$

[0095] As shown in Table 2 below, PAA450Na exhibited a high complexation yield, suggesting that the majority of COOH groups reacted with Na. PAANaY also showed a similar complexation yield, suggesting a small number of COOH groups and that the majority of COO groups are bonded to metal ion Na or Y.

TABLE-US-00002 TABLE 2 A.sub.C−H A.sub.COOH % complexation PAA450 0.411 1.605     0% PAA450Na 4.91  1.835 90.42% PAA450NaY 0.306 0.025  97.9%

[0096] TGA Results

[0097] Thermogravimetry analysis of the polymer-metal complexes described above was used to reveal variation of thermal stability by complexation with metal ions (creation of COOM bonds). Generally, the thermal decomposition behavior of a polymer-metal complex depends on the macromolecular characteristics of the polymer support and the type of coordination geometry. Un-complexed PAA (comprising only COOH) was shown to undergo multiple decomposition steps with increasing temperatures:

[0098] Step A: Evaporation of absorbed water molecules;

[0099] Step B: Release of water from intramolecular anhydride formation due to heating;

[0100] Step C: Release of water from intermolecular anhydride formation due to heating;

[0101] Step D: Decarboxylation and decomposition; and

[0102] Step E: Organic burn.

[0103] All 5 decomposition steps noted for PAA450 were as expected. PAA450Na exhibited a higher weight loss at the beginning, as compared to PAA450, due to water evaporation; however, from step B to D only approximately 10% weight loss was observed as compared to PAA450 (which showed an 82% weight loss). This small decrease in weight indicated the lack of COOH groups and supported the observation that the majority of COOH groups reacted with NaOH to yield new COONa bonds with better thermal stability. From step E, PAA45Na showed a deep decrease in weight due to burning of the organic moieties of the polymer.

[0104] PAA450NaZr behaved in a similar way to PAA450, suggesting pronounced amount of carboxylic acid groups (step B to D) and supports a low degree of conversion. PAA450NaY behaved in a similar way to PAA450Na, suggesting presence of a small amount of carboxylic acid groups (step B to D), indicating a high degree of conversion. Both PAA450NaY and PAA450NaZr demonstrated smaller weight losses with increasing temperatures as compared to PAA450. This indicates an enhanced thermal stability of the new COOM (M=Zr or Y) ionomers.

[0105] Comparing PAA450NaY to PAA450NaZr, PAA450NaY exhibited smaller weight loss meaning better thermal stability. For PAA450NaY a residual of 61% inorganic (Y) content was observed at the end of test temperature of 600° C.

[0106] XRF Results

[0107] XRF readings of polymers of the invention showed that before a metal, e.g., yttrium underwent complexation, no metal was detected in PAA450 and PAA450Na. However, after complexation, the peak intensity was increased, confirming the presence of the metal, e.g., yttrium.

[0108] Condensation Reaction with MAH-g-PP or AA-g-PE

[0109] A common way of increasing the adhesion, compatibilization, wettability properties of polymers is modification with a polar polymer or low molecular weight additive such as maleic anhydride, unsaturated carboxylic derivatives and vinyl or acrylic compounds containing more than one functional group. The low molecular weight compounds can be grafted on the polymer in the melt, forming graft or block co-polymers during processing.

[0110] Maleic anhydride-grafted polypropylene (MAH-g-PP) is a compatibilizer which is very effective and commonly used for polymer matrix at the interface. It is used for improving poor interfacial adhesion between additives and PP matrix. The addition of 2.5%-5.0% of MA-g-PP to a PP composite did not affect the T.sub.m value.

[0111] Condensation of PAA450 with MAH-g-PP

[0112] PAA450 and MAH-g-PP were first heated at 80° C. for 2 h and then mixed in a tremble mixer for 10 min The mixed PAA450 and MAH-g-PP were compounded by co-rotating twin screw extruder and operated temperatures for barrel zones were 160° C., 165° C., 170° C. and 175° C., and the temperature of die zone was 180° C.

[0113] Condensation of PAA450NaY with MAH-g-PP

[0114] PAA450NaY and MAH-g-PP were first heated at 80° C. for 2 h and then mixed in a tremble mixer for 10 min. The mixed PAA450NaY and MAH-g-PP were compounded by co-rotating twin screw extruder and operated temperatures for barrel zones were 160° C., 165° C., 170° C. and 175° C., and the temperature of die zone was 180° C.

[0115] Condensation of PAA450NaZr with MAH-g-PP

[0116] PAA450NaZr and MAH-g-PP were first heated at 80° C. for 2 h and then mixed in a tremble mixer for 10 min. The mixed PAA450NaZr and MAH-g-PP were compounded by co-rotating twin screw extruder and operated temperatures for barrel zones were 160° C., 165° C., 170° C. and 175° C., and the temperature of die zone was 180° C.

[0117] Condensation of PAA450NaMo with MAH-g-PP

[0118] PAA450NaMo and MAH-g-PP were first heated at 80° C. for 2 h and then mixed in a tremble mixer for 10 min. The mixed PAA450NaMo and MAH-g-PP were compounded by co-rotating twin screw extruder and operated temperatures for barrel zones were 160° C., 165° C., 170° C. and 175° C., and the temperature of die zone was 180° C.

[0119] Condensation of PAA450KY with MAH-g-PP

[0120] PAA450KY and MAH-g-PP were first heated at 80° C. for 2 h and then mixed in a tremble mixer for 10 min. The mixed PAA450KY and MAH-g-PP were compounded by co-rotating twin screw extruder and operated temperatures for barrel zones were 160° C., 165° C., 170° C. and 175° C., and the temperature of die zone was 180° C.

[0121] Condensation of PAA450KZr with MAH-g-PP

[0122] PAA450KZr and MAH-g-PP were first heated at 80° C. for 2 h and then mixed in a tremble mixer for 10 min. The mixed PAA450KZr and MAH-g-PP were compounded by co-rotating twin screw extruder and operated temperatures for barrel zones were 160° C., 165° C., 170° C. and 175° C., and the temperature of die zone was 180° C.

[0123] Condensation of PAA450KMo with MAH-g-PP

[0124] PAA450KMo and MAH-g-PP were first heated at 80° C. for 2 h and then mixed in a tremble mixer for 10 min. The mixed PAA450KMo and MAH-g-PP were compounded by co-rotating twin screw extruder and operated temperatures for barrel zones were 160° C., 165° C., 170° C. and 175° C., and the temperature of die zone was 180° C.

[0125] Condensation of PAA6NaY with MAH-g-PP

[0126] PAA6NaY and MAH-g-PP were first heated at 80° C. for 2 h and then mixed in a tremble mixer for 10 min. The mixed PAA6NaY and MAH-g-PP were compounded by co-rotating twin screw extruder and operated temperatures for barrel zones were 160° C., 165° C., 170° C. and 175° C., and the temperature of die zone was 180° C.

[0127] Condensation of PAA6NaZr with MAH-g-PP

[0128] PAA6NaZr and MAH-g-PP were first heated at 80° C. for 2 h and then mixed in a tremble mixer for 10 min. The mixed PAA6NaZr and MAH-g-PP were compounded by co-rotating twin screw extruder and operated temperatures for barrel zones were 160° C., 165° C., 170° C. and 175° C., and the temperature of die zone was 180° C.

[0129] Condensation of PAA6NaMo with MAH-g-PP

[0130] PAA6NaMo and MAH-g-PP were first heated at 80° C. for 2 h and then mixed in a tremble mixer for 10 min The mixed PAA6NaMo and MAH-g-PP were compounded by co-rotating twin screw extruder and operated temperatures for barrel zones were 160° C., 165° C., 170° C. and 175° C., and the temperature of die zone was 180° C.

[0131] Compatibility of the immiscible blend components can be greatly improved using peroxides, taking advantage of high reactivity of polyolefins to free radical that good starting point for promoting compatibilization between polypropylene or polyethylene with low molecular weight compounds can be used by adding in the melt to initiate grafting—coupling reactions forming graft or block co-polymers during processing.

[0132] Master Batch Production

[0133] PAA450-MAH-g-PP pellets were dehydrated in convection drying oven at 80° C. for 3 h and subsequently compounded with PP to produce a concentrated master batch (a reference Master batch). The reference master batch was dry blended with PP at different ratios and injected by injection molding to produce specimens for testing.

[0134] In a similar fashion, master batches of PAA450NaY-MAH-g-PP, PAA450NaZr-MAH-g-PP, PAA450NaMo-MAH-g-PP, PAA450KY-MAH-g-PP, PAA450KZr-MAH-g-PP, PAA450KMo-MAH-g-PP, PAA6NaY-MAH-g-PP, PAA6NaZr-MAH-g-PP, PAA6NaMo-MAH-g-PP, and others could be prepared.