WO2015038129A1

WO2015038129A1 - Coated sorbents and methods of making

Info

Publication number: WO2015038129A1
Application number: PCT/US2013/059467
Authority: WO
Inventors: Chieh-Chun Chau; Samuel A. Incorvia; Louis Patrone
Original assignee: Multisorb Technologies, Inc.
Priority date: 2013-09-12
Filing date: 2013-09-12
Publication date: 2015-03-19

Abstract

A sorbent compound for melt extrusion in a polymer includes a particulate porous sorbent having pores extending from the surface into the body of the particle. A lubricating coating that facilitates melt extrusion of the particles with a polymer compound covers the surface, but not the pores. The method includes the steps of hydrating the sorbent to fill the voids or pores in the sorbent with water or other substance that the sorbent is capable of absorbing, coating the hydrated gel with a lubricating material or other material, then removing the water or other substance so that the voids in the gel structure are free from water and not coated with the lubricating material. A substantial portion of the surface of the exterior of the gel particle is thereby coated with the coating material for easy feeding in a compounding feeder while leaving the pores essentially free from coating.

Description

TITLE OF THE INVENTION

COATED SORBENTS AND METHODS OF MAKING

BACKGROUND OF THE INVENTION

FIELD OF THE INVENTION

[0001 ] This invention relates generally to sorbents and more particularly to coated, finely-divided, particulate sorbents for compounding in a polymer melt.

DESCRIPTION OF RELATED ART

[0002] Silica gel and activated carbon are examples of sorbents that are commonly used as desiccants and volatile organic absorbers. Silica gel and activated carbon are highly porous and hygroscopic and the bulk density of these sorbents is low. Because these sorbents are fluffy and hygroscopic, they are hard to feed smoothly from a hopper to extrude in a compou nding extruder. Issues such as inconsistent feed, caking, and bridging at the feed port often occur. These difficulties become more pronounced as the loading content and feed rate are increased.

[0003] Silica gel compounds with a polymer such as but not limited to polypropylene and nylon can be injection molded or extruded into shaped articles. The shaped articles are used for moisture absorption or regulation in electronic, automotive, food, pharmaceutical, and other types of packaging products.

[0004] It is not easy to coat silica gel or other porous or microporous sorbents with a lubricant or protective coating because the coating materials can be absorbed into silica gel due to its high absorption functionality. Unlike coating of other inorganic mineral particles, direct coating could negatively affect the absorption functionality of such sorbents.

[0005] A sorbent and a method of providing a particulate sorbent having smooth, consistent, and high feeding rate characteristics to achieve high loadings of silica gel in a polymer matrix while maintaining absorption capacity are desired.

BRIEF SUMMARY OF THE INVENTION

[0006] Briefly stated and in accordance with one aspect of the invention, a method and sorbent particles made in accordance with the method to enable high loading of a sorbent such as silica gel and activated carbon in extrusion with a polymer to form a compound are provided. The resulting compound can be shaped into molded articles, machinable articles, films, sheets, and other shaped articles. [0007] In accordance with another aspect of the invention, a method to allow easy feeding of silica gel or activated carbon in extrusion to make a sorbent loaded polymer compound is described.

[0008] In accordance with yet another aspect of the invention a formulation to facilitate feeding of fine powdery sorbent such as silica gel or activated carbon for extrusion compounding is described.

[0009] In accordance with a further aspect of the invention, a method of making a silica gel compound that includes a lubricant coated on the silica gel prior to melt extrusion with a polymer is described. The

lubricated silica gel facilitates extrusion without compromising its

absorptive capacity.

[001 0] In accordance with a still further aspect of the invention a compound that contains silica gel with a mean particle size of 300 microns or smaller and with the silica gel loading of 20% or higher and a method for making the compound are described.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

[001 1 ] The novel aspects of the invention are set forth with

particularity in the appended claims. The invention itself, together with further objects and advantages thereof may be better understood by referring to the following detailed description of a number of embodiments of the invention taken in connection with the accompanying drawing in which:

[001 2] Figure 1 is a diagrammatic view in cross section of a porous sorbent particle; [001 3] Figure 2 is the diagrammatic cross-sectional view of the particle of Figure 1 showing the pores filled with an absorbable substance;

[001 4] Figure 3 is the diagrammatic cross-sectional view of the particle of Figure 2 coated with a lubricating coating;

[001 5] Figure 4 is the diagrammatic cross-sectional view of the particle of Figure 3 showing the pores emptied and free of coating;

[001 6] Figure 5 is the diagrammatic cross-sectional view of the particle of Figure 2 coated with a protective coating and a lubricating coating;

[001 7] Figure 6 is the diagrammatic cross-sectional view of the particle of Figure 5 showing the pores emptied and free of coating;

[001 8] Figure 7 is a diagrammatic view of an extruded sheet of a sorbent material with multiple particles of Figure 4 or Figure 6 imbedded within it; [001 9] Figure 8 is a cross-sectional view of a blister pack for a pharmaceutical product made from the sorbent material of Figure 7;

[0020] Figure 9 is a thermoformed or injection molded cup made from the sorbent material in Figure 7; [0021 ] Figure 1 0 is a thermoformed or injection molded lidded cup where the lidding material is made from the sorbent material in Figure 7;

[0022] Figure 1 1 is a thermoformed or injection molded tray made of the sorbent material in Figure 7;

[0023] Figure 1 2 is an overwrapped tray protecting a perishable item where the overwrap is made from the sorbent material in Figure 7;

[0024] Figure 1 3 is a lidded thermoformed or injection molded tray where the lid stock is made from the sorbent material in Figure 7;

[0025] Figure 1 4 is an enclosed electronic device with a housing made from the sorbent material in Figure 7; [0026] Figure 1 5 is a flip top vial made from the sorbent material in Figure 7, containing some perishable items;

[0027] Figure 1 6 is an open top vial made from the sorbent material in Figure 7; [0028] Figure 1 7 is an extruded or injection molded hollow cylinder or tu be made of the sorbent material in Figure 7;

[0029] Figure 1 8 is an extruded or injection molded solid cylinder made of the sorbent material in Figure 7; [0030] Figure 1 9 is a machinable blank made from the sorbent material in Figure 7; and

[0031 ] Figure 20 is an injection molded or blow molded bottle made of the sorbent material in Figure 7.

DETAILED DESCRIPTION OF THE INVENTION

[0032] A method of making a coated sorbent with improved feeding characteristics, for example, for use in compounding with a polymer, injection molding, extrusion, and other polymer processing; and a microporous sorbent made by the method are described. While the embodiments described herein use silica gel as an example sorbent, the invention is not so limited. Other particulate porous or microporous sorbents such as but not limited to activated carbon, volatile acid

absorbers, hydrocarbon absorbers, molecular sieves, clay, and calcium chloride may also be used. As used herein, "porous" is intended to include "microporous." When silica gel is referred to, it should be understood that such other sorbents are intended to be included. The improved compound can contain a high loading of silica gel with retained absorption capacity and optionally with enhanced absorption rate.

[0033] A method according to this disclosure includes the steps of hydrating the sorbent to fill the voids or pores in the silica gel with optionally coating the hydrated gel with a protective layer, coating the hydrated gel with a lubricating material or other material, and then removing the water or other pore filling substance so that the pores in the gel structure are free from water and not coated with the lubricating or other material. A substantial portion of the surface of the gel particle is thereby coated with the coating material for easy feeding, such as into a compounding feeder while leaving the pores free from coating to maintain the effectiveness of the sorbent. While the invention is described by way of example in which silica gel is hydrated, it will be understood that sorbents that absorb materials other than water would have their pores filled with the material they are intended to absorb. Additionally, while the invention is also described by way of example in which the sorbent is hydrated with water, it will be understood that other materials than water can fill their pores, examples of such being alcohols, volatile substances and various combinations thereof, and that the invention should not be limited as such. [0034] The coating can also provide additional functionality. By selecting an appropriate coating material, it can enhance properties such as the absorption rate, adhesion to the polymer matrix, the ability to be sintered, and other characteristics. Moreover, the interior of the gel particle is intact and the absorption performance of the gel is unaffected.

[0035] Figure 1 is a schematic view of an uncoated silica gel particle 1 0 having a plurality of pores 1 2 extending from a surface 1 3 of the particle into the body thereof. The drawing is representative only. The actual silica gel particles have many more pores than shown. Additionally, the size of the pores 1 2 is exaggerated and fewer pores than actually exist are shown for illustrative purposes only. Actual silica gels pores range from approximately 0.5 nanometers to 300 nanometers or more depending upon the type of sorbent, and are many in number. Additionally, there are smaller pores within the primary surface pores, along with side channels, and branches which contain smaller pores themselves. This microporous structure creates a large surface area in proportion to the overall size and internal volume of the particle, allowing for a high degree of absorption.

[0036] The silica gel 1 0 can be any of the well-known types with various pore sizes and geometries. The mean particle size of the gel can range from 1 to 300 microns, preferably 2 to 1 00 microns as determined by conventional particle size analyzing techniques. [0037] As shown in Figures 2-4, a coated sorbent particle 22 may be manufactured by the following steps: [0038] 1 . Hydrate the silica gel particle 1 0 with water 1 4 to at least substantially fill the pores 1 2, as shown in Figure 2;

[0039] 2. Coat or encapsulate the hydrated gel l 0 with a polymer or compound 1 8, as shown in Figure 3; and [0040] 3. Dry the particles to remove the water 1 4 to create a coated particle 22 as shown in Figure 4, with the surface coated, but the pores free of coating.

[0041 ] The dried particles 22 illustrated in Figure 4 may be extruded with a polymer, for example. [0042] Another method of manufacturing a coated sorbent is illustrated by Figures 2, 5, and 6. The manufacturing method may include the following steps:

[0043] 1 . Hydrate the silica gel particle 1 0 with water 1 4 to at least substantially fill the pores 1 2, as shown in Figure 2; [0044] 2. Coat or encapsulate the hydrated gel 1 0 with a first polymer or compound 24 followed by coating the particle again with a second polymer or compound 1 8, as shown in Figure 5; and

[0045] 3. Remove the water 1 4 to create a coated particle 28 as shown in Figure 6 with the surface coated, but the pores free of coating. [0046] The particles manufactured according to such a method may be extruded with a polymer 30.

[0047] Referring to Figures 1 -4, silica gel particles 1 0 are first hydrated with water 1 4 to saturate the pores 1 2 and fill or at least substantially fill all or at least a large portion of the pores 1 2, extending inwardly from the surface of the particle 1 0, with water 1 4. A typical water content of the filled silica gel 1 0 is about 20% or more by weight. It can vary from about 5% to 30% depending on the morphology of the particle. Preferably, only enough water to fill the pores is used and no excess water 1 4 is used which would induce agglomeration of the sorbent particles, or cause the residual moisture to be higher than desired. The hydrating process can be done in a conventional mixer or blender with the water 1 4 added continuously to the gel 1 0 by spray jets or other known means, while the gel 1 0 is being agitated in the mixer, preferably by mechanical agitation, or other known means.

[0048] A number of lubricating formulations such as the materials described below can provide the easy feeding characteristics of the coated gel 1 0 in the making of extruded compounds.

[0049] Although lubrication is of interest, the coating materials 1 8 can generally be any of lubricants, surfactants, and adhesives or other materials that enhance the characteristics of the sorbent particles for a desired purpose. Lubricants can consist of saturated fatty acids such as stearic acid (O s), palmitic acid (Ο ε), myristic acid (CM) and lauric acid (C12), and/or unsaturated fatty acids such as oleic (Ci s) acid. They can also be metal-substituted fatty acids such as zinc stearate, calcium stearate, aluminum stearate, sodium stearate, magnesium stearate and the like.

They can also be acid esters such as stearyl stearate and montan wax. They can also be saturated hydrocarbons such as alkanes and mineral oils. They can also be hydrocarbon-based waxes such as paraffin wax and polyolefin- based waxes of different molecular weights. They can also be acid amides such as plastic processing slip additives erucamide, stearamide and oleamide. Surfactants can be soaps such as sodium stearate as also classified under metal-substituted fatty acid, benzenesulfonate,

polyethylene oxide, anionic sulfate, sulfonate, phosphate, and carboxylates and any compounds classified as surfactants. Adhesives can be any reactive or bonding materials that can bond the sorbents to a polymer matrix such as silane coupling agents, epoxy-based crosslinking agents, and other functionalized adhesives that could change the surface

characteristics, such as polarity, hydrophobicity, or reactivity, of the sorbents. [0050] The thickness of the coating can vary depending on the natu re of the material and the particle size of the sorbents. It can range from 0.5 to 1 00 micron, preferably 1 to 20 micron. It is ideal to use a thin enough coating to provide the desired functionality, without being so thin that the functionality is lost, or so thick a coating that the particles could start to agglomerate.

[0051 ] Prior to applying a coating material, a protective material 26 that is compatible with the state of hydration may be applied to the hydrated gel. The protective material is preferably a water-soluble polymer such as polyvinylpyrrolidone (PVP), polyethylene oxide (PEO), polyethylene glycol (PEG), polyvinyl alcohol (PVOH) or others. It can also be any hygroscopic material that is compatible with the hydrated gel such as water-based polymer emulsions such as a poly(lactic) acid emulsion, an acrylic latex emulsion, a styrene latex emulsion, and the like.

[0052] Referring now to Figure 3, the hydrated gel 1 6 in particulate form is now coated with a protective material 1 8 and/or a lubricating material. The coating material can be a polymer or another organic or inorganic compound that has the required lubricating characteristics for the sorbent and polymer involved. The material can be coated using known means, but in such a fashion that the coating 1 8 does not enter the interior pore structure of the silica gel 1 0.

[0053] The coating method can vary depending on the nature of the material. A liquid polymer solution can be added to a quantity of hydrated silica gel 1 6 in a blender while under agitation. Care should be taken to prevent particles from combining into clusters of gels with portions of the gel 1 6 uncoated. A lubricating coating such as stearic acid or wax can be heated to melt the material into liquid then sprayed onto the gel being mixed. The coated silica gel 20 is then dried to remove the water 1 4 absorbed in the structure. The drying can be done in an oven at a

temperature sufficient to reduce the water content to 5% by weight or below, preferably 3% or below, more preferably 1 % or below. This temperature can range between around 80°C to around 1 00°C, and is preferably around 90°C. This temperature range allows for the water to be driven off, without causing the coating to melt off the particle, or scorch the particle itself, which can occur at temperatures over 1 00°C.

[0054] Optionally the dried or de-hydrated silica gel 22 can be ground to break up the clusters, to homogenize the blend, and/or to narrow the particle size distribution. [0055] The coated, de-hydrated gel 22 can then be used for extrusion compounding. The encapsulated gel may be fed in a hopper in an extruder to extrude with a polymer30. Suitable polymers include polyolefins such as polypropylene, polyethylene, and their copolymers; polystyrene, polyesters such as PET and PLA, nylon, polycarbonate, PMMA and other common thermoplastics. The loading of the coated silica gel in the polymer 22 can range from 1 0 to 60% by weight. In some embodiments, extrusions of 40% or higher loading with easy feeding characteristics are permitted.

[0056] The following are examples of some aspects of this disclosure:

[0057] Example 1 : Preparation of PVP coated silica gel and

compou nds

[0058] Five gallons of water was mixed slowly in a Sigma mixer with 490 lbs. of silica gel supplied by Multisorb Technologies Inc. (MTI) having particle sizes ranging from 1 to 300 microns. The silica gel/water mixture was stored in a container until the moisture content in the gel, determined by weight loss method by heating the samples in an oven, was

approximately 20.8%.

[0059] The hydrated silica gel was coated with a polyvinylpyrrolidone solution, such as Luvitec^® K90 (available from BASF) solution that

contained 20% of PVP in water. 540 lbs. of hydrated gel was pre-mixed in a mixer with 1 75 lbs. of PVP solution that was fed into the gel at

approximately 55^°C with the mixer running. The mixture was fu lly homogenized and then cooled to room temperature.

[0060] The PVP coated silica gel was ground in a grinder and sifted through two screen packs with 40 and 200 mesh screens respectively. The residual moisture content in the ground silica gel /PVP mixture was measured at approximately 20%. The mixture was then dried in a forced air oven at approximately 90^°C for various times to achieve residual moisture of 5% or lower. The dried mixture was then used for extrusion.

[0061 ] Polyolefin resins including Sunoco CP360H polypropylene and Dow LDPE 6401 low density polyethylene were used in extruding the compou nds. The resins were fed into the extruder that was set at temperatures ranging from 1 80^° C - 220^° C across the heating zones with the die temperature set at 220^° C.

[0062] Sample #1 is a control sample that was made by extruding dried uncoated silica gel with the polypropylene in a twin screw extruder without coating. The silica gel was dried in the forced air oven at 90^°C for 24 hours to achieve residual moisture of 3% or below. The dried silica gel was then fed from a feeder connected to the extruder to allow the silica gel to merge into the polymer melt. The compounded strands were cooled and pelletized.

[0063] The PVP coated silica gel was extruded with the polypropylene and LDPE resins in the twin screw extruder. The resins were fed into the extruder at the same set temperatures ranging from 1 80^° C - 220^° C across the heating zones with the die temperature set at 220^° C. The PVP coated silica gel was then fed from the same feeder connected to the extruder to allow the silica gel to merge into the polymer melt. The compounded strands were cooled and pelletized in the same manner. Sample 2 is the polypropylene compound and Sample 3 is the LDPE compound both consisted of the PVP coated silica gel as described above. Table-1 summarizes the samples with respect to the types of the material, the content of silica gel and the description of the process and treatment methods of the silica gel.

[0064] Example 2: Preparation of stearic acid and PVP coated silica gel and compounds

[0065] Gasil^® 200DF silica gel with a mean particle size of

approximately 4.5 micron was obtained from PQ Corporation. The gel was pre-mixed in a Hobart mixer with water continuously dripping in from a tube with the mixer running to reach moisture content of approximately 22.7%. A Luvitec^® K90 (BASF) aqueous solution that contained 20% of PVP was diluted with water to achieve a net PVP content of approximately 1 0%. This diluted PVP solution was added to the hydrated gel while mixing in the mixer to achieve a weight ratio of PVP solution/hydrated gel equal to 31 /69%. After the blend was homogenized through sufficient mixing, about 5% parts per hundred by weight of stearic acid in powder form obtained from Aldrich Chemical was added to the blend. It is important to ensure that the wetted particles are still free flowing and not forming agglomerates. The blend was then further mixed in the mixer to achieve homogeneity.

[0066] The total mixture, approximately 5 lbs., was then dried in a forced air oven for 24 hours at between 70- 1 00 degrees C, though the preferred temperature is about 90-degrees C to remove the moisture and to prevent volatilization or decomposition of the lu bricating layer, such as stearic acid in this case. The material ratio in the mixture was Gasil^®

200DF/PVP/stearic acid = 73 /22 / 5. The residual moisture by weight loss measurement was determined to be approximately 3% or lower. The mixture was then used for extrusion.

[0067] As a comparison, Gasil^® 200DF silica gel was mixed with stearic acid without hydrating with water. Stearic acid and Gasil^® 200DF gel were mixed with approximately 5 /95 ratio in a Hobart mixer and with the same quantity as above. The mixture was heated in the forced air oven at 90C for 24 hours to dry any residual moisture and allow the stearic acid to melt and coat onto the silica gel.

[0068] Dow polyethylene LDPE640I was used for extruding with the silica gel materials as prepared. The process set up and condition were the same as described above. The compounded strands were pelletized. [0069] Sample 4 is an LDPE compou nd that was made with Gasil^®

200DF silica gel mixed and coated with stearic acid without hydrating with water. Sample 5 is an LDPE compound made with Gasil^® 200DF silica gel that was hydrated-coated-dehydrated and with material ratio of Gasil^® 200DF/PVP/stearic acid = 73 /22 / 5. Table- 1 shows a comparison of Sample 4 and Sample 5 with respect to the types of the material, the content of silica gel and the description of the process and treatment methods of the silica gel.

[0070] Example 3 : Moisture absorption performance

[0071 ] The silica gel content in the compounds was determined by Thermal Gravimetric Analyzer (TGA) in a TA Instrument TGA2950 analyzer. Samples were heated from room temperature to 580^° C in a nitrogen purged oven and cooled to room temperature. Plastic resins and organic coatings were decomposed in this heating process. The weight loss versus temperature was recorded. The silica gel content indicated by the residue weight determined by using the software of the instrument was used for calculation of the moisture absorption capacity.

[0072] The compounded pellets were compression molded to form sheets in a Carver hot press. The molded sheets were cut into 3"x2"x0.02" pieces and dried in a vacuum chamber to remove any residual moisture. The dried sheet samples were stored in an 80% relative hu midity (RH) chamber at 25^° C for 480 hours for a moisture absorption test. The absorption capacity for various examples is listed in Table- 1 . [0073] Table-1 : Moisture absorption capacity of silica gel compounds with various encapsulation methods

[0074] Test data show that coated silica gel has a higher absorption capacity than uncoated gel. For PQ Gasil^® 200DF gel, the absorption capacity on net gel weight basis of the hydrate-coat-dehydrate sample (Sample 5) was notably higher than that of the gel simply coated with stearic acid (Sample 4 ). The compounds also allowed greater amounts of gel to be loaded. The higher capacity and higher loading allowed the total absorption capacity of the molded sheet for the hydrate-coat-dehydrate sample (Sample 5) to be higher on milligram per unit volume basis. [0075] For samples from MTI gel, the absorption capacity on net gel weight basis of the hydrate-coat-dehydrate compounds (Sample 2, Sample 3) was about the same as that of the non-coated gel (Sample 1 )

compounded in polypropylene. However, the hydrate-coat-dehydrate compounds allowed higher gel loadings in the matrix with smoother feeding due to the lubricity of the coating. As a result the total absorption capacity of the molded sheets for the hydrate-coat-dehydrate samples was higher on milligram per unit volume basis. For product absorption performance, the benefit can be determined by multiplying the weight of the product by the weight percent of silica gel and by the percent of absorption/gel weight, to get the total absorption.

[0076] Once pelletized, the pellets can be remelted so that the sorbent loaded resin 30 can be used for a number of plastic products. Such products are illustrated, but not limited to those in Figures 8-20. One such product, as illustrated in Figure 8, is a blister pack 31 protecting a pharmaceutical or nutraceutical product 32. The blister pack 31 has a thermoformed layer 33 and a covering layer 34 each of which could be made from the sorbent loaded resin 30.

[0077] Figures 9 and 1 0 illustrate an open cup 35 and a sealed cup 38, respectively. In Figure 9, the cup 35 protects a sensitive material 36 by having its body 37 made of the sorbent loaded with sorbent loaded resin 30. However, the sorbent cup 38 protects the sensitive material 36 by having an injection molded or thermoformed cup 39 made of the sorbent loaded resin 30, having an extruded lid stock 40 made of the sorbent loaded resin 30, or having both the cup 39 and the lid stock 40 made of the sorbent loaded resin 30.

[0078] Figures 1 1 through 1 3 illustrate the use of the sorbent loaded resin 30 with trays. Figure 1 1 illustrates a tray 41 where the body 42 is made of the sorbent loaded resin 30. The overwrapped tray 43 in Figure 1 2 protects a sensitive material 44 by having an overwrap 46 made of the sorbent loaded resin 30. However, a tray 45 could also be made of the sorbent loaded resin 30, and the overwrap 46 could be a standard resin or made of the sorbent loaded resin 30. Additionally, as shown in Figure 1 3, a package 47 protecting the sensitive material 44 could be a tray 48 covered with a lid stock 49, and the lid stock 49, the tray 48 or both could be made of the sorbent loaded resin 30.

[0079] The sorbent loaded resin can also be used to protect sensitive electronic devices as shown in Figure 1 4. Here, the outer housing 51 of an electronic device 50 could be made of the sorbent loaded resin 30 to protect the interior electronic components 52. In addition, or as an alternative, the electronic components 52 could have portions made from the sorbent loaded resin 30, or the sorbent loaded resin could be a stand^¬ alone part designed to conform to a specific space.

[0080] The sorbent loaded resin 30 can also be used to protect sensitive material 55 stored in vials as shown in Figures 1 5 and 1 6. While a first vial 53 has an integrated cap and a second vial 56 does not, bodies 54, 57 of each vial may be made of the sorbent loaded resin 30. In the case of the first vial 53, the cap 64 and hinge 66 could be made of the sorbent loaded resin 30 or be made from compatible non-sorbent loaded resin. For the second vial 56, a separable cap (not shown) could be made of the sorbent loaded resin, or could be made of non-loaded resin as well.

[0081 ] Because of its versatility, the material can also be injection molded or extruded in any desired form as shown in Figures 1 7- 1 9. This ranges from tubular designs 58, solid canisters or cylinders 59, and multifaceted machineable blocks 60. These conformations are flexible in their use, such as a separate component for another assembly, or as a stand-alone item. Besides peptization followed by injection or blow molding, the sorbent could be sintered into forms as shown in Figures 1 7- 1 9. The sintering can be performed with the sorbent loaded resin in a pelletized form or as individual discrete particles resulting in a form that has a high degree of porosity. In the case of sintering in pelletized form, the coated sorbent particles are compounded and pelletized with any polymer that would be compatible with the sintering process. The pellets would then be used for the sintering process. When sintering discrete particles, the lubricating coating is selected to be compatible with the method of sintering used. This could be, but is not limited to, a coating comprising 5% silane coupling agents, or other compatible resin. In this instance, standard sintering techniques can be used, as one would be sintering the resin or coupling agents together instead of the actual particles. This would also decrease the likelihood of dusting particles with the sorbent embedded in them, a common problem with standard sintered products.

[0082] The sorbent loaded resin 30 can also be used for the body 32 of a bottle 61 to protect a sensitive material 62 as shown in Figure 20. The bottle 61 can be produced by either blow molding, or by injection molding, though any standard molding technique can also be used. [0083] While the invention has been described in connection with a number of embodiments thereof, those skilled in the art will recognize that many modifications and changes may be made therein without departing from the true spirit and scope of the invention which accordingly is intended to be defined solely by the appended claims.

Claims

1 . A sorbent compound comprising: a particulate porous sorbent comprising a plurality of particles, each of the particles having a body having a surface and a plurality of pores extending from the surface into the body; and a lubricating coating on the surface of the particles, but not the pores, the coating facilitating melt extrusion of the particles with a polymer compound.

2. The sorbent compound of claim 1 in which the lubricating coating comprises a material selected from the group consisting of: water- soluble polymers, lubricants, surfactants, adhesives, polyvinylpyrrolidone, polyethylene oxide, polyethylene glycol, polyvinyl alcohol, wax,

functionalized wax, saturated fatty acids, metal substiatuted fatty acid, acid ester, saturated hydrocarbon, hydrocarbon-based wax, or polyolefin based waxes, stearic acid, palmitic acid, myristic acid, lauric acid, oleic acid, zinc stearate, calcium stearate, aluminum stearate, sodium stearate, magnesium stearate, stearyl stearate, montan wax, alkanes, mineral oils, paraffin wax, erucamide, stearamide, oleamide, sodium stearate, benzenesulfonate, anionic sulfate, sulfonate, phosphate, carboxylates, polyethylene oxide, silane coupling agent, or epoxy-based crosslinking agents, coatings that change the surface polarity, coatings that change the su rface hydrophobicity, and coatings that change the surface reactivity.

3. The sorbent compou nd of claim 1 in which the particulate porous sorbent is selected from the group consisting of: silica gel, activated carbon, volatile acid absorbers, hydrocarbon absorbers, and molecular sieves, clay, and calcium chloride.

4. The sorbent compou nd of claim 1 in which the lubricating coating comprises a layer having a thickness of about 0.5 to 1 00 microns.

5. The sorbent compou nd of claim 4 in which the layer has a thickness of about 1 to 20 microns.

6. The sorbent compou nd of claim 1 in which the particles have an absorbed substance content of at least about 5%-30% by weight

7. The sorbent compou nd of claim 1 in which the particles have an absorbed substance content of at least about 20% by weight.

8. The sorbent compou nd of claim 6 in which the absorbed substance is selected from a group consisting of water, alcohol, absorbable volatile chemicals, and combinations thereof.

9. The sorbent compound of claim 1 further comprising an intermediate layer of protective coating between the surface of the particles and the lubricating coating.

1 0. The sorbent compound of claim 9 in which the lubricating coating has a thickness of about 0.5 to 1 00 microns.

1 1 . The sorbent compound of claim 1 0 in which the lubricating coating has a thickness of about 1 to 20 microns.

1 2. The sorbent compound of claim 9 in which the protective coating comprises a material selected from a group consisting of: water- soluble polymers, hygroscopic materials, polyvinylpyrrolidone (PVP), polyethylene oxide (PEO), polyethylene glycol (PEG), polyvinyl alcohol (PVOH), water-based polymer emulsions such as poly(lactic) acid based emulsion, acrylic latex emulsions, and styrene latex emulsions.

1 3. The sorbent compound of claim 1 0 in which the lubricating coating comprises a material selected from a group consisting of: water- soluble polymers, lubricants, surfactants, adhesives, polyvinylpyrrolidone, polyethylene oxide, polyethylene glycol, polyvinyl alcohol, wax,

functionalized wax, saturated fatty acids, metal substiatuted fatty acid, acid ester, saturated hydrocarbon, hydrocarbon-based wax, or polyolefin based waxes, stearic acid, palmitic acid, myristic acid, lauric acid, oleic acid, zinc stearate, calcium stearate, aluminum stearate, sodium stearate, magnesium stearate, stearyl stearate, montan wax, alkanes, mineral oils, paraffin wax, erucamide, stearamide, oleamide, sodium stearate, benzenesulfonate, anionic sulfate, sulfonate, phosphate, carboxylates, polyethylene oxide, silane coupling agent, epoxy-based crosslinking agents, coatings that change the surface polarity, coatings that change the su rface

hydrophobicity, and coatings that change the surface reactivity.

1 4. The sorbent compou nd of claim 9 in which the particulate porous sorbent comprises a sorbent selected from a group consisting of: silica gel, activated carbon, volatile acid absorbers, molecular sieves, clay, and calcium chloride.

1 5. The sorbent compou nd of claim 9 in which the particulate porous sorbent has an absorbable substance content of at least about 30%.

1 6. The sorbent compou nd of claim 9 in which the particulate porous sorbent has an absorbable substance content of at least 20%.

1 7. The sorbent compou nd of claim 1 5 in which the absorbable substance is selected from a group consisting of water, alcohol, absorbable volatile substances, and combinations thereof.

1 8. A method comprising: providing a particulate porous sorbent comprising a plurality of particles, each of the particles having a plurality of pores; filling the pores of the particles; coating the particles with a lubricating coating after filling the pores; and emptying the pores after coating the particles.

1 9. The method of claim 1 8 in which the particulate porous sorbent is selected from a group consisting of: silica gel, activated carbon, volatile acid absorbers, hydrocarbon absorbers, molecular sieves, clay, and calcium chloride.

20. The method of claim 1 8 in which the particulate porous sorbent comprises particles having a size ranging from about 1 to 300 microns.

21 . The method of claim 1 8 in which filling the pores comprises filling the pores with an absorbable substance.

22. The method of claim 21 in which the absorbable substance is selected from a group consisting of water, alcohol, absorbable volatile substances, and combinations thereof.

23. The method of claim 21 in which filling the pores with an absorbable substance comprises mixing the particulate porous sorbent with the absorbable substance.

24. The method of claim 23 in which the absorbable substance is sprayed on the particulate porous sorbent.

25. The method of claim 23 in which the absorbable substance is poured on the particulate porous sorbent.

26. The method of claim 23, further comprising agitating the particulate porous sorbent and the absorbable substance until

homogenous.

27. The method of claim 26, further comprising storing the sorbent and the absorbable substance mixture in a container.

28. The method of claim 21 comprising filling the pores with the absorbable substance until the absorbable substance content is at least 5%-30% by weight.

29. The method of claim 28 comprising filling the pores with the absorbable substance until the absorbable substance content is at least 20% by weight.

30. The method of claim 1 8 in which coating the particles with lubricating coating comprises coating the particles with

polyvinylpyrrolidone.

31 . The method of claim 30 in which coating the particles with polyvinylpyrrolidone comprises coating the particles with a solution of 20% polyvinylpyrrolidone.

32. The method of claim 1 8 in which coating the particles with a lubricating coating comprises mixing the particles and lubricating coating in a mixer.

33. The method of claim 1 8 in which coating the particles with a lubricating coating comprises adding the lubricating coating to the particles at a temperature of between about 40°C and 90°C.

34. The method of claim 1 8, further comprising cooling the coated particles to room temperature.

35. The method of claim 1 8 in which coating the particles with a lubricating coating comprises maintaining a residual absorbable substance level of the particles to about 5% by weight or more.

36. The method of claim 1 8 in which coating the particles with a lubricating coating comprises maintaining a residual absorbable substance level of the particles to at least 20% by weight or more.

37. The method of claim 1 8, further comprising grinding the coated particles after emptying the pores.

38. The method of claim 37, further comprising sifting the ground particles.

39. The method of claim 38 in which sifting the particles comprises sifting through 40 mesh and 200 mesh screens.

40. The method of claim 21 , further comprising drying the particles to remove the absorbable substance.

41 . The method of claim 40 in which drying the particles to remove the absorbable substance comprises removing the absorbable substance so that the particles have at most 5% residual absorbable substance by weight.

42. The method of claim 1 8, further comprising compounding the sorbent particles with a polymer.

43. The method of claim 42 in which compounding the sorbent and the polymer comprises extruding at least one strand of combined sorbent and polymer and pelletizing at least one strand of combined sorbent and resin.

44. The method of claim 42 in which the polymer comprises a material selected from a group consisting of: polypropylene, polyethylene, polypropylene copolymers, polyethylene copolymers, polyester, polylactic acid, polyethylene terephthalate, nylon, polycarbonate, and

polymethylmethacralate.

45. The method of claim 1 8, further comprising coating the particles with a protective coating prior to coating the particles with the lubricating coating.

46. The method of claim 45 in which the particles comprise silica gel having a size ranging from 1 to 300 microns.

47. The method of claim 45 in which the filling of the pores comprises filling the pores with an absorbable substance.

48. The method of claim 47 in which the absorbable substance is selected from a group consisting of water, alcohols, volatile chemicals, and combinations thereof.

49. The method of claim 47, further comprising mixing the particulate porous sorbent and the absorbable substance.

50. The method of claim 47, further comprising agitating the sorbent and the absorbable substance until homogenous.

51 . The method of claim 47 in which the filling the pores with an absorbable substance comprises filling the pores with the absorbable substance until the absorbable substance content is about5% to 30% by weight.

52. The method of claim 47 in which the filling the pores with an absorbable substance comprises filling the pores with the absorbable substance until the absorbable substance content is at least 20% by weight.

53. The method of claim 45 in which coating the particles with the protective coating comprises coating the particles with

polyvinylpyrrolidone.

54. The method of claim 53 in which coating the particles with polyvinylpyrrolidone comprises coating the particles with a solution of 1 0% polyvinylpyrrolidone.

55. The method of claim 45 wherein coating the particles with the protective coating comprises mixing the particles and protective coating in a mixer.

56. The method of claim 45 in which coating the particles with a protective coating comprises having a protective coating to particle weight ratio of about 31 /69.

57. The method of claim 45 in which the coating the coated particle with the lubricating coating comprises coating the coated particle with stearic acid.

58. The method of claim 57 in which the coating the coated particle with stearic acid comprises achieving a ratio of 5 parts stearic acid per hundred parts of coated particle.

59. The method of claim 45, in which filling the pores comprises filling the pores with an absorbable substance and emptying the pores comprises drying the particles to remove the absorbable substance.

60. The method of claim 59 in which drying the particles

comprises exposing the particles to a temperature between about 70°C and 1 00°C.

61 . The method of claim 60 in which the temperature is about

90°C.

62. The method of claim 59 in which drying the particles to remove the absorbable substance comprises removing the absorbable substance until the particles have at most about 3% residual absorbable substance by weight.

63. The method of claim 45, further comprising compounding the sorbent particles with a polymer.

64. The method of claim 63 in which the sorbent particles are compounded with the polymer using an extruder and further comprising making at least one strand of combined sorbent and polymer and

pelletizing at least one strand of combined sorbent and resin.

65. The method of claim 63 in which the polymer comprises a material selected from a group consisting of: polypropylene, polyethylene, polypropylene copolymers, polyethylene copolymers, polyester, polylactic acid, polyethylene terephthalate, nylon, polycarbonate, and

polymethylmethacralate.

66. A sorbent loaded polymer comprising: a polymer body; a sorbent entrained in the body, the sorbent comprising particles having a body having a surface, a plurality of pores extending from the surface into the body, and a coating on the surface of the body but not in the pores.

67. The sorbent loaded polymer of claim 66 in which the coating comprises a lubricating coating.

68. The sorbent compound of claim 67 in which the lubricating coating comprises a material selected from a group consisting of: water- soluble polymers, lubricants, surfactants, adhesives, polyvinylpyrrolidone, polyethylene oxide, polyethylene glycol, polyvinyl alcohol, wax,

functionalized wax, saturated fatty acids, metal substiatuted fatty acid, acid ester, saturated hydrocarbon, hydrocarbon-based wax, polyolefin based waxes, stearic acid, palmitic acid, myristic acid, or lauric acid oleic acid, zinc stearate, calcium stearate, aluminum stearate, sodium stearate, magnesium stearate, stearyl stearate, montan wax, alkanes, mineral oils, paraffin wax erucamide, stearamide, oleamide, sodium stearate,

benzenesulfonate, anionic sulfate, sulfonate, phosphate, and carboxylates or polyethylene oxide silane coupling agent, epoxy-based crosslinking agents, coatings that change the surface polarity, coatings that change the surface hydrophobicity, and coatings that change the surface reactivity.

69. The sorbent loaded polymer of claim 66 in which the sorbent is selected from the group consisting of: silica gel, activated carbon, volatile acid absorbers, molecular sieve, clay and calcium chloride.

70. The sorbent loaded polymer of claim 66 in which the polymer body comprises a polymer selected from the group consisting of polyolefins, polyesters, and polystyrene, polypropylene, polyethylene, and their copolymers; polystyrene, polyesters, PET, PLA, nylon, polycarbonate, and poly(methyl methacrylate).

71 . The sorbent loaded polymer of claim 66 in which the sorbent has a particle size of from 1 -300 micron.

72. The sorbent loaded polymer of claim 66 in which the coating comprises polyvinylpyrrolidone.

73. The sorbent loaded polymer of claim 66 in which the sorbent comprises silica gel having a mean particle size of about 4.5 micron and the coating comprises polyvinylpyrrolidone.

74. The sorbent loaded polymer of claim 66, the polymer further comprising an intermediate coating between the surface of the particles and the coating.

75. The sorbent loaded polymer of claim 74 in which the

intermediate coating comprises a material selected from a group consisting of: water-soluble polymers, hygroscopic materials, polyvinylpyrrolidone (PVP), polyethylene oxide (PEO), polyethylene glycol (PEG), polyvinyl alcohol (PVOH), water-based acrylic latex emulsions, and styrene latex emulsions.

76. The sorbent loaded polymer of claim 74 in which the coating comprises a material selected from a group consisting of: water-soluble polymers, lubricants, surfactants, adhesives, polyvinylpyrrolidone, polyethylene oxide, polyethylene glycol, polyvinyl alcohol, wax,

functionalized wax, saturated fatty acids, metal substiatuted fatty acid, acid ester, saturated hydrocarbon, hydrocarbon-based wax, polyolefin based waxes, stearic acid, palmitic acid, myristic acid, or lauric acid oleic acid, zinc stearate, calcium stearate, aluminum stearate, sodium stearate, magnesium stearate, stearyl stearate, montan wax, alkanes, mineral oils, paraffin wax erucamide, stearamide, oleamide, sodium stearate, benzenesulfonate, anionic sulfate, sulfonate, phosphate, and carboxylates or polyethylene oxide silane coupling agent, epoxy-based crosslinking agents, coatings that change the surface polarity, coatings that change the surface hydrophobicity, and coatings that change the surface reactivity.

77. The sorbent loaded polymer of claim 66 in which the sorbent has a residual absorbable substance level of about 3% or less.

78. The sorbent loaded polymer of claim 66 in which the polymer is pelletized.

79. The sorbent loaded polymer of claim 78 in which the pellets are sintered together to form a porous article.

80. The porous article of claim 79 in which the porous article absorbs a composition selected from a group comprising: oils, volatile gases, flue gases, hydrocarbons, exhaust gases, carbon dioxide, and water vapor.

81 . An article comprising a sorbent compound of coated porous sorbent without coating pores of the sorbent and a resin.

82. The article of claim 81 wherein the article comprises a molded article, a molded housing, an insert or a fit-in piece, a blister pack, a cup, a tray, a housing, lidstock, a wrap, a liner, an integrated part, a flip-top vial, an open ended vial, a machineable blank, a tube, a pouch, or a bottle

83. The article in claim 82 in which the article is used with a material from a group consisting of: pharmaceuticals, test strips, effervescent tablets, electronic devices, electronic components, chemicals, chemical preparations, and consumable products.

84. The article of claim 82 in which the article is used in

conjunction with a second article from the group consisting of: molded articles, cups, blister packs, single-serve containers, bottles, paperboard containers, and cans.