GB2459541A

GB2459541A - Liquid desiccant

Info

Publication number: GB2459541A
Application number: GB0808095A
Authority: GB
Inventors: Ian Armstrong
Original assignee: Carclo Technical Plastics Ltd
Current assignee: Carclo Technical Plastics Ltd
Priority date: 2008-05-01
Filing date: 2008-05-01
Publication date: 2009-11-04
Anticipated expiration: 2028-05-01
Also published as: GB2459541B; GB0808095D0

Abstract

A liquid desiccant composition, the liquid desiccant composition comprises a molecular sieve. Preferably the molecular sieve is an aluminosilicate comprising a zeolite. Preferably the liquid desiccant composition includes an adhesive such as paraffin wax in granular or solid form or polyethylene glycol in solid form. Preferably the liquid desiccant composition includes a solvent such as n-heptane or butyl alcohols especially n-butanol although other aliphatic solvents may be used. The composition may be applied to substrates or products such as Early Pregnancy Test Kits or In-Vitro Diagnostic kits. Another invention is to a liquid desiccant composition that comprises a desiccant, an adhesive and a carrier solvent.

Description

LIQUID DESICCANT

The present invention relates generally to desiccants, and more particularly to a liquid desiccant composition having improved properties.

Desiccant materials are used in many aspects of modem life, from paper manufacturing, inks, paints, cloth and textile protection, electrical appliances, double glazing, hydrocarbon (liquids and gases) drying to pharmaceutical and drugs. The main function of desiccants is to keep moisture levels [namely Relative Humidity (RH)] down below at least 50% to stop dampness and microorganisms or bacteria from thriving or to minimise adsorption of other odorous substances.

Some products do need very low humidity levels (<lO%RH) to keep the product functionality as required, for example in the area of In-Vitro Diagnostic (I\TD) test kits. This is important to ensure that the testing kits are protected against elements that can limit their shelf life or quality, and this is a crucial part of the manufacturing process.

A vast range of commercial desiccants are made of one or a combination of *.S.

these basic essential material; Zeolites (Molecular Sieves), Silica Gel, Clay * .** ** (Bentonite), Calcium Oxide (CaO), Precipitated Calcium Carbonate (PCC), * *. Magnesium Sulphate and Calcium Chloride (Anhydride).

Desiccants are typically provided in solid form, for example as packets of silica gel or the like. Whilst these are reasonably satisfactory for many purposes, we have found there can be drawbacks with solid desiccants, depending upon the S..

* : * particular application where activity is required. The disadvantages of solid desiccants include that they cannot be integrated within the product, specially if the product is small in size; they do not give direct or on the spot protection for moisture sensitive material since it will protect the adjacent areas only; and they cannot be tailored to the product specific shape, size or the recommended dosage of desiccant.

Having appreciated the drawbacks with solid desiccants, we have now devised a liquid desiccant that substantially overcomes these problems.

In its broadest aspects, the present invention provides a desiccant composition in liquid form, particularly a desiccant composition based upon a molecular sieve. The composition can be sprayed, dispensed or otherwise deposited on a substrate and then dried to form a solid film having desiccant properties. The invention thus provides a

I

desiccant, which can integrate with a substrate or product, so dispensing with the need for separate or additional desiccants.

In one aspect, the present invention provides a liquid desiccant composition comprising a desiccant, an adhesive and a carrier solvent.

In a highly preferred aspect, the desiccant is a molecular sieve. Accordingly, the invention provides a liquid desiccant composition comprising a molecular sieve, an adhesive and a carrier solvent.

Our liquid desiccant invention is the first real liquid desiccant to provide on the spot desiccant protection in the fields of drugs and pharmaceutical products such as IVD kits.

The advantages of our liquid desiccant over ready made solid forms are: no limitation in usage in any product related to shape or size; can be integrated within the product itself or within the manufacturing process; provide protection to IVD kits or the product even during or after use by the end user (e.g. if the seal is broken); less space for packaging since it will be integrated inside the product; it will applied as a liquid which then changes to solid on the finished product. This is advantageous S...

: since the liquid desiccant will not be active when in the liquid state but only when S.. transformed from liquid form to solid form, so it can be stored in a cold place (for * ** example) ready to use at any time; the composition of the liquid desiccant is simple *.: and the ingredients are cheap and cost effective as well as non-toxic in its final solid form. Whilst certain liquid, paste or cream desiccants have been marketed, these had *... been formulated to target liquid water or surface moisture. None of them can effectively adsorb atmospheric moisture to the same low level as the present * S compositions, and thus can not provide the required level of protection.

A molecular sieve is a material containing tiny pores of a precise and uniform size, as will be well known to the skilled chemist. Molecular sieve can be naturally mined or synthetically produced compounds. Any suitable molecular sieve may be used, although we prefer to use aluminosilicate minerals, such as Zeolites. Metal aluminosilicates may be used, for example.

The adhesive is preferably paraffin wax (in granular or solid form) or a polyethylene glycol (particularly in solid form).

The carrier solvent is preferably Heptanes, especially n-Heptane, or Butyl alcohols, especially n-Butanol, although other aliphatic solvents may be used if desired.

Accordingly, in a preferred aspect, the invention provides a liquid desiccant composition comprising a molecular sieve, an adhesive that is paraffin wax or polyethylene glycol, and a carrier solvent.

A preferred embodiment is a liquid desiccant composition comprising a molecular sieve, which is an aluminosilicate compound, an adhesive that is paraffin wax or polyethylene glycol, and a carrier solvent.

Particularly preferred embodiments include heptane, especially n-Heptane and/or Butanol, especially n-Butanol, as a solvent.

The invention also provides a process comprises applying a composition of the invention to the substrate and drying.

Preferably the drying is at elevated temperature, for example, above room temperature (25°C). We prefer to oven dry, particularly at a temperature of from 60°C to 80°C. Drying flashes off the solvent. We prefer to dry for short times, for example from 120 to 150 seconds. The composition may be sprayed, dispensed or otherwise deposited on the substrate.

The substrate can be any substrate where desiccant activity is required in the * local environment, but the invention is particularly applicable to plastics and * ***,*e packaging, including plastic parts and packaging materials for pharmaceutical * ** applications. Examples of these include Early Pregnancy Test (EPT) and In-Vitro Diagnostic (IVD) kits, where moisture levels are critical for the accuracy and reliability of the test.

** **** Thus, the invention includes a substance or product comprising a liquid **** desiccant composition as described herein. It will be understood that since the solvent *..* * is flashed off, the liquid desiccant will form a solidified film on the substrate. It will be appreciated, therefore, that the invention encompasses substrates or products comprising the dried or solidified form of liquid desiccant compositions of the invention.

Preferred embodiments include an Early Pregnancy Test (EPT) or an In-Vitro Diagnostic (IVD) kit comprising a liquid desiccant composition according to the invention.

The compositions of the invention display a number of advantages. Since the compositions are in liquid form, the amount of composition can be dispensed or applied very precisely on hard to reach places, such as irregular mould cavities. The thickness of the film applied to the substrate surface can also be precisely controlled.

The compositions can be freshly prepared as required, giving an don-demand" capability, which also gives greater cost effectiveness since only the required amount is used. Since the compositions are physically applied to the product, this provides an integrated solution and dispenses with the need for separate desiccants.

The compositions display good adhesion to a variety of substrates, including most plastics and most pharmaceutical plastic packaging. The compositions have a high water adsorption capacity and can maintain low levels of relative humidity (RB), for example 10% RH or lower. They are homogenous and have a stable viscosity, have a long storage life and are safe for household use and disposal. They can be easily tailored to the demands (e.g. space and shape) of the substrates to which they are applied, and are cost effective in terms of raw materials. The compositions can be easily integrated into a production system, and are porous to allow free migration of water vapour from the atmosphere to the active desiccant when thy. After application and drying, the compositions provide a stable solid end product, which does not crumble under normal stresses. This is important in terms of customer confidence.

The compositions are easily dried with minimal complexity.

The formulations of the invention have a much higher rate of adsorption than * *** existing desiccants (for example ActiveTabTM). Suitably, the formulations provide * ** 10% relative humidity (RH) or less within 1 hour.

Preferably, in terms of adsorption, particularly water adsorption, the composition reaches equilibrium (i.e. a steady state value) within 48 hours, or more preferably within about 24 hours.

Whilst any suitable desiccant may be used (including silica gel and clays such * *,**u * as Bentonite), we prefer to use a molecular sieve. Generally speaking, these compounds have a higher water capacity at lower humidity than clay or silica gel.

They also perform more effectively as moisture absorbers at higher (greater than 25°C) or lower temperatures than clay or silica gel, and they can also adsorb water more rapidly. Molecular sieves may also be tailored to absorb water vapour only, even when other liquid vapours exist in the atmosphere. In particular, we have found that molecular sieves can be satisfactorily incorporated into liquid formulation.

Molecular sieves include natural mined or synthetically produced products (Zeolites), highly porous crystalline metallo-alumino silicates. They have many internal cavities that are linked by window openings of precise diameters. It is these diameters (measured in Angstroms) that classify molecular sieves -3A, 4A, 5A and 1OA (also known as 13X). Adsorption occurs only of molecules with smaller diameters than those cavity openings (this gives a very high surface area -about 1800 square meters per gram). Larger molecules will be excluded from adsorption.

Preferentially adsorbed are molecules of greater polarity. This makes molecular sieves ideal for adsorption of water from air and liquids. As water molecules and other contaminants from liquids and gases down to very low levels-often just 1 part per million. So, they are preferred when low level humidity is require or when it is crucial to achieve close to 0% Relative Humidity. Examples of some differing molecular sieve grades are: Grade 3A: the pores in the desiccant (Type 3A) Zeolites are perfectly sized and shaped to hold water molecules (to dry unsaturated gases and organic liquids, e.g. methanol). Used to remove water from cleaning fluids in ultrasonic baths.

Grade 4A: is a general dryer of liquids, natural gases, and excellent adsorber of carbon dioxide.

Grade 1OA: is used in air pre-purification (due to its high water and carbon dioxide adsorption capacity) and also adsorbs sulphur compounds (sweetens'). It will.

remove decomposition products following the quenching of arcing in electrical * **.

** , products.

* We prefer to use an aluminosilicate molecular sieve, particularly a metal :.. aluminosilicate molecular sieve, of which the Zeolites are examples. Zeolites are a group of aluminosilicates of sodium, potassium, calcium and barium. We particularly prefer to use grade 3A. One particular example is Sylosiv� A3 available from Grace S...

Davison. This is a micronised, highly porous, crystalline aluminosilicate with pore I....' * openings of approximately 3A.

Other documents include silica gel and Bentonite, as described further below.

Silica gel is an amorphous form of silicon dioxide, which is synthetically produced in the form of hard irregular granules (having the appearance of crystals) or hard irregular beads. A micro-porous structure of interlocking cavities (800 square meters per gram). It is this structure that makes silica gel a high capacity desiccant.

Water molecules adhere to the gels surface because it exhibits a lower vapour pressure than the surrounding air. When equilibrium of equal pressure is reached, no more adsorption occurs. Thus the higher the humidity of the surrounding air, the greater the amount of water that is adsorbed before equilibrium reached. It is in these higher humidity conditions (above 50% Relative Humidity) that stored or in-transit items are susceptible to damage.

Bentonite is smectite clay formed from the alternation of siliceous, glass-rich volcanic rocks such as tuffs and ash deposits. The major mineral in bentonite is montmorillonite, a hydrated sodium, calcium, magnesium, and aluminium silicate Cao.16[Al1.68Mgo.32(OH)2(Si4010)]. The sodium, calcium, and magnesium cations are interchangeable giving the montmorillonite a high ion exchange capacity. With water molecules binding predominantly to the cation interlayers of the fine clay crystals, the absorption capacity of clay increases with rising humidity and is higher than the absorption capacity of silica gel when conditions are below 30% relative humidity. Since clay reacts relatively slowly at low as well as high humidity levels, it slowly reduces the humidity in closed containers, but it is easy to handle. In addition, desiccant clay granules have up to 30% greater density than either silica gel or molecular sieve beads, thereby occupying less space. The industrial bentonites are generally either the sodium or calcium variety. Bentonites are important and essential in a wide range of markets including drilling mud, foundry sand binding, iron ore pelletizing, pet waste absorbents; * :. and civil engineering uses such as waterproofing and sealing. Clay is a cheaper option and generally 5-I 5% less expensive than the same amount of silica gel. **..

s.. The adhesive in the in the composition serves to stabilise the desiccant, and to * .. provide flexibility but also rigidity to the composition. It should also provide good adhesion to the chosen substrate, and be compatible with the range of different packaging materials. Bearing in mind these requirements, any suitable adhesive may be used. We particularly prefer to use waxes, such as paraffin wax from Acros Organics. **.

For example, low melting point (e.g. around 55°C) or high melting point (e.g. around 77°C) paraffin wax may be used. Alternatively, or in addition, another preferred adhesive is polyethylene glycol (PEG) from Acros Organics. The molecular weight of the PEG may vary and suitable examples include PEG1000 (m.p. 37°C), PEG1500 (m.p. 46°C), PEG4000 (m.p. 5 7°C) and PEG8000 (m.p. 5 7°C). We have found, PEG4000 to be particularly suitable in terms of its solvent dissolution properties, water adsorption, adhesion to plastics and dry desiccant surface rigidity.

The carrier solvent enables the desiccant to be presented as a liquid formulation.

The carrier solvent is preferably immiscible with water, and volatile such that it can be easily flashed off parts, which the composition is applied. Solvents with low flash points are therefore preferred. Preferably the solvent has no interaction with the desiccant or adhesive, or the substrate or parts to which it is applied, or any relevant packaging material. Suitably, the solvent is hydrophobic and evaporates easily. With these requirements in mind, any suitable solvent may be used. Solvents with low polarity are preferred, particularly when a PEG adhesive is employed -this ensures PEG dissolution.

Solvents with low or negligible water adsorption are preferred. Suitable examples include heptane, particularly n-heptane that has a low flash point (4°C) and negligible water absorption (<0.00 1%). Heptane is particularly suitable for use with wax adhesives as it can dissolve wax to make slurry. Another suitable solvent is Butanol, particularly n-butanol that has more organic behaviour than lower alcohols or ketones. It has a reasonably low water absorbency (<7%) and acceptable flash point (28°C), and is non-toxic.

Two particular embodiments have been found to give good results. In one embodiment, the liquid desiccant composition comprises a desiccant, which is a molecular sieve, particularly an aluminosilicate compound, and an adhesive, which is a wax, particularly paraffin wax, and a carrier solvent, which is heptane, particularly n-heptane.

* : * In a second embodiment, the liquid desiccant composition comprises a desiccant, which is a molecular sieve, particularly aluminosilicate compound, an adhesive, which is * a polyethylene glycol, particularly PEG4000, and a carrier solvent, which is butanol, : *. particularly n-butanol. S...

The liquid compositions of the invention are simple to prepare and generally this involves simple addition and mixing of the components. Suitably, the solid components * . are added to the carrier solvent and then homogenised. For example, the adhesive may be ***.

* : added to the solvent, followed by homogenisation to achieve a one-phase slurry. The active desiccant may then be added, followed by further homogenisation. The result is suitably a stable suspension of desiccant (e.g. a molecular sieve) in an adhesive/solvent solution.

In use, the composition is dispensed, typically sprayed, on to a substrate such as a plastic part or component. The solvent is then removed (i.e. flashed off) by drying to leave a dry, solid coating or film. Drying preferably comprises drying at elevated temperature (e.g. above 50°C), suitably by oven drying, followed by air drying, typically at room temperature and at lower than ambient relative humidity (e.g. < 30%RH). The oven-drying step is preferably short, for example between 30 to 300 seconds, although times of from 120 to 150 seconds are preferred. Drying at elevated temperature may be at any suitable temperature, depending upon the exact constitution of the formulation, but a preferred drying time is from 120 to 150 seconds. Air-drying can be for any suitable time, the principle requirement being to ensure that the residual solvent level is effectively zero. Flashing off the solvent should be carried out with good ventilation to reduce the risk of fire, To illustrate the invention, preferred embodiments thereof will now be described with reference to the accompanying drawings (which in no way restTict the scope of the invention and are for the purpose of illustration only) in which: Figure 1 shows the effect of oven flash-off time on residual solvent levels in certain preferred desiccant compositions.

Figure 2 shows the effect of mixing ratios on residual solvent levels in certain preferred desiccant compositions.

Figure 3 shows the effect of oven flash-off time and duration on the water adsorption capacity of certain Liquid Desiccant type 1 (LDT1) compositions.

Figure 4 shows the effect of oven flash-off time on the water adsorption capacity of certain Liquid Desiccant Type2 (LDT2) compositions.

Figure 5 shows the water adsorption capacity of the known desiccant Acti.v-TabTM. * ..S

Two particular liquid desiccant compositions have been developed, known as : ** Liquid desiccant Type I (LDT1) and Liquid desiccant Type 2 (LDT2). LDT1 comprises S...

an aluminosilicate molecular sieve as desiccant (especially Sylosiv� A3 from Grace Davison), a paraffin wax as adhesive from Acros Organics (either low m.p. wax, 55°C or high m.p. wax 77°C), and n-heptane as solvent. LDT2 comprises the same desiccant (e.g. * :* * Sylosiv� A3), a polyethylene glycol as adhesive (from Acros Organics), and n-butanol as solvent.

LDTI formulations have generally been found to reach equilibrium within about 24hrs or less, whereas LDT2 formulations generally reach equilibrium within about 48hrs or less. Generally speaking, increasing the amount of adhesive in the formulation tends to extend the time taken to reach equilibrium and may adversely affect the water adsorption capacity, so we prefer to use low levels of adhesive where possible.

Preferred LDT1 formulations, based on mixing ratios for a molecular sieve present at 10 parts, comprise from 1 to 10 parts of adhesive, for example 1, 2, 4 and 10 parts of adhesive. The carrier solvent preferably ranges from 10 parts to 20 parts. The mixing ratio ranges will affect the adsorption capacity as well as ease of dispensing.

Preferred ratios are around 10-parts molecular sieve to I to 2 parts adhesive and 15 to 18 parts of carrier solvent, preferably n-heptane. The moisture adsorption capacity for this particular ratio range will be 72% to 100 % of the overall desiccant capacity.

Preferred LDT2 formulations, based on mixing ratios for a molecular sieve present at 10 parts, comprise from 1 to 10 parts of PEG adhesive, for example 1,2,3,and 4 and up to 10 parts of PEG adhesive (PEG1000, or PEG1500, or PEG4000 or PEG8000) with added carrier solvent from 10 to 20 parts. The preferred ratio is 10 parts molecular sieve to 1,2,and 4 parts of adhesive (preferred PEG4000) and 18 parts of carrier solvent preferably n-butanol. The moisture adsorption capacity for this particular ratio range will be 76% to 100 % of the overall desiccant capacity.

The following apparatus was used to prepare and test the compositions.

1. Digital Balance with 1mg accuracy (ADAM 50) 2. Homogeniser (with SS Mincer) up to 24,000 rpm (PowerGen 500) 3. Fridge N 4. Temperature and humidity meter 5. Oven (forced or natural convection) 6. Stop watchlalarm timer *..* * * . 7. Micro-jet spray 781S-SS with 780S controller from EFD * .I* **** 8. Lab-ware such as: Test tubes, spatulas, pipettes,..etc. * ** * S S *..

LDT1 formulations were prepared as follows: 1. Weight about Ig of paraffin wax (either low melting point (LMP) wax or high melting point (HMP) wax) using spatula and aluminium pan. ****

* :.: 2. Empty the wax into a test tube and then add 1 8m1 of Heptane on top using a disposable pipette 3. Dissolve the wax in heptane, using the homogeniser. Mix at rate of 14,000 rpm for half minute or until one milky homogeneous one phase slurry is obtained.

4. Weight quickly about log of molecular sieve SylosivA3 using spatula and aluminium pan.

5. Empty the pan content into the test tube and use the homogeniser gently at around 8,000 rpm with up and down movement of the test tube to ensure well mixing and distribution of the desiccant within the slurry liquid.

6. Cover the test tube open with aluminium foil and put in the fridge for later use.

7. Clean the homogeniser mincer using another test tube with half-fill clean heptane as a cleaning agent. Dry the mincer with tissue.

LDT2 formulations were prepared in a similar manner, but using PEG as adhesive and n-butanol as the solvent.

Formulations were sprayed on to plastic substrates. Three types of thennoplastic substrates were used: Polystyrene (EPT kit), PMMA (Polymethylmethacrylate) and Polycarbonate (Tova windows).

A micro-jet 781 from EFD was used to control the amount and dispensing time. The time for dispensing was set to 200-250 milliseconds.

An important consideration is the need for the solvent to be removed, i.e. flashed off from the composition as quickly and as completely as possible, after application of the composition to a substrate. This can be affected by the formulation itself (e.g. the mixing ratios of the various components), as well as the processing * conditions such as the drying time and temperature.

Accordingly, residual solvent calculations (i.e. the amount of solvent S...

*. remaining in the composition after a given time) were made for various formulations * .. under different conditions. Certain results are presented in Figures 1 and 2.

The residual solvent calculations were made as follows: i. Desiccant samples were weighed after: dispensing, oven, and later at room conditions (typically 25°C and 24-30 %RH) on lhr, 24hrs and 4 S...

days periods.

S.....

* ii. Two types of mass transfer processes govern each sample: evaporation and adsorption which takes place at the same time. The first is the flashing-off the solvent (weight loss) while the other is water adsorption, which contributed to (weight gain) of the sample.

iii. In order to determine the rate of solvent flashing and the residual solvent quantity remains in the sample as related to heating time inside the oven; a dead Molecular Sieve (saturated) was used in preparation of the desiccant compositions.

Fig. 1 shows the effect of oven drying time (at 80°C) on residual solvent level for various compositions on a (Tova) Substrate. Fig. 2 shows the effect of varying the mixing ratios of the components in LDT 1 and LDT2 compositions on residual solvent levels after different times (and whilst varying the duration of the initial oven drying flash). Appendix A (Al-A4) gives further details of the accompanying calculations.

It can be seen that after 24 hours (apart from the initial oven drying, samples are left at room temperature) there is no residual solvent for any of the compositions.

However, certain compositions achieve no residual solvent after only 1 hour, although this also depends upon the duration of the initial oven drying. Generally speaking, the longer the duration of the initial oven drying, the lower the residual solvent level after 1 hour.

Appendix AS shows melting point characteristics for different adhesives.

A critical feature of the compositions is their ability to adsorb water from the surrounding environment so as to keep the moisture content at or below the required level. Tests were carried out on various LDT1 and LDT2 compositions to measure water adsorption capacity, and certain results are presented in Figs. 3 and 4.

Fig. 3 shows the effect of varying the initial oven solvent-flash temperature and duration on the final water adsorption capacity of an LDTI composition comprising either low imp paraffin wax (5 5°C average) or high m.p paraffin wax *..* * . . (77°C average) as adhesive, and using either EPT or Tova as substrates. The water *.. . s.. adsorption calculations are made by accurate weighing of the samples, and assume * that the residual solvent level will be 0% after 24hrs. Appendix B (B I -B2) gives further details of the calculations. The final water adsorption is calculated based upon measurements after 4 days (i.e. where a steady state has been achieved).

Fig. 4 shows the effect of varying the initial oven solvent-flash duration on the *** * : * : final water adsorption capacity of an LDT2 composition comprising either 1500 or PEG4000 as adhesive, using either Tova or EPT as the substrate. The calculations are made as for LDT2 described above, and Appendix C (Cl-C2) gives further details of the calculations.

It can be seen from Figs. 3 and 4 that excellent final water adsorption can be achieved for all the compositions tested, although the optimum values are affected by the flash times and temperatures employed during oven drying. Higher oven temperatures appear to have an unreliable effect on the final water adsorption capacity, particularly when using low m.p wax, although this effect may also be observed with LDT2 systems using PEG. Physical inspection of the final samples indicated that the physical appearance and strength of the dried desiccant coatings varied depending upon the oven flashing temperature and time used.

In general, our results suggest that a drying step comprising oven drying for around 120-150 seconds at a temperature of from about 60 to 80°C provides good consistency in terms of the end properties of the dried desiccant coating. These processing conditions may be appropriate depending upon the ratio of the components in the formulation.

To highlight the performance of compositions according to the invention, a comparison was made with the present type of desiccant used in EPT kit by Carclo Technical Plastics, which is the ActivTabTM. Baltimore Innovations developed this desiccant tablet. The water adsorption performance of ActivTabTM was tested and the results are shown in Fig. 5.

Fig. 5 shows that for each tablet tested, the water adsorption is slow to occur and the values even after 168 hours (12% or less by weight) are poor in comparison to those achieved with LDT1 and LDT2 systems. For example, with an LDT1 composition, we found an average water adsorption of 22.9% by weight and for.

LDT2 composition, an average water adsorption of 19.6% by weight. Based on these * * * * figures it can be seen that: **. . * * 0..0 * *. Equivalent Weight Calculation * The weight of ActivTabTM tablet is around 0.42g with 12% water adsorption capacity. This means that about 0.050g of water is the required amount to be adsorbed. S.

* LDT1 desiccant average water adsorption capacity is 22.9% or weight of desiccant required to adsorb 0.050g is O.22g dry weight (0.54g wet) * LDT2 desiccant average water adsorption capacity is 19.6% or weight of desiccant required to adsorb O.050g is 0.25g dry weight (0.46g wet) This simple calculation shows that the weight for weight, much less of either LDT1 or LDT2 composition is required for achieve the same level of water adsorption. This results in significant cost savings and reduces the quantity (i.e. weight) of desiccant formulation required.

APPENDICES

Appendix A: Determination of the residual solvent Al-System: MS: PEG4000: n-Butanol MIX RATIO 10: 1: 18 A2-System: MS: PEG4000: n-Butanol MIX RATIO 10: 2: 18 A3-System: MS: PEG4000: n-Butanol MIX RATIO 10: 4: 18 A4-System: MS: Wax: n-Heptane MIX RATIO 10: 1: 18 A5-Adhesives Melting Temperatures Appendix B: Bi-LDT1 -Low Melting Wax B2-LDTI -High Melting Wax Appendix C: Cl-LDT2 Low Melting PEG 1500 C2-LDT2 -High Melting PEG 4000 * S * I * *** * S

SIP S * *S * S S *SSS *05S * S *SSS

S S, * S

* a * . * S S S * *S * * * * a. S * * * S * * * . . .* * S S * S *.a * . Appendix A (Determination of the residual solvent) _______ ____ __________ Al Tova System MS: PEG4000: n-Butanol MIX RATIO 10: 1: 18 Substrate _____ _______ ________ ________ ___________ _______ ___________ _________ ____________ ___________ _____________ Oven temp 80°C Pan (g) Sample Solvent Sample after Solvent Solvent Sample Solvent Sample after Solvent remain (g) max (g) oven flash lost (g) remain% after lhr remain after 24hrs (g) after 24hrs% __________ _____ ______ ________ ________ (g) _______ after oven (g) lhr% __________ ____________ OvenTime 30s 2.874 3.056 0.096 3.045 0.011 89% 2.960 0% 2.961 0% (Sec) 60s 2.906 3.067 0.085 3.033 0.034 60% 2.982 0% 2.982 0% 120s 2.874 3.065 0.101 3.008 0.057 43% 2.963 0% 2.962 0% __________ 300s 2.902 3.071 0.089 2.986 0.085 5% 2.984 0% 2.984 0% ____________ A2 Substrate Tova System MS: PEG4000: n-Butanol MIX RATIO 10: 2: 18 Oven temp 80°C Pan (g) Sample Solvent Sample after Solvent Solvent Sample Solvent Sample after Solvent remain (g) max (g) oven flash lost (g) remain% after lhr remain after 24hrs (g) after 24hrs% _________ _____ ______ _______ _______ (g) _______ after oven (g) lhr% _________ ___________ Oven Time 30s 2.908 3.053 0.077 3.040 0.013 83% 2.976 0% 2.979 0% (Sec) 60s 2.878 3.054 0.093 3.027 0.027 71% 2.975 15% 2.966 0% 120s 2.908 3.056 0.078 3.018 0.038 51% 2.980 3% 2.979 0% __________ 300s 2.877 3.058 0.096 2.977 0.081 15% 2.965 3% 2.965 0% * . ** * * ** * * * . * . . * * . ,. * U * * * S * * * . U ** * . * U U * * *.. U * . *5 ___________ _______ _________________ A3 Substrate Tova System MS: PEG4000: n-Butanol MIX RATIO 10: 4: 18 Oven temp 80°C Pan (g) Sample Solvent Sample after Solvent Solvent Sample Solvent Sample after Solvent remain (g) max (g) oven flash lost (g) remain% after lhr remain after 24hrs (g) after 24hrs% _________ ______ ______ _______ ________ (g) _______ after oven (g) I hr% __________ ____________ Oven Time 30s 2.878 3.065 0.099 3.043 0.022 78% 2.982 16% 2.981 0% (See) ______ ______ ________ ________ ___________ _______ __________ ________ ___________ __________ ____________ 60s 2.907 3.069 0.086 3.025 0.044 49% 2.997 16% 2.997 0% 120s 2.878 3.072 0.102 2.994 0.078 24% 2.987 17% 2.987 0% _________ 300s 2.910 3.075 0.087 2.997 0.078 10% 3.000 0% 3.000 0% ___________ ______ ________________ A4 ______________________________________________________________ Substrate Tova System MS: Wax: n-Heptane MIX RATIO 10: 1: 18 Oven temp 80°C Pan (g) Sample Solvent Sample after Solvent Solvent Sample Solvent Sample after Solvent remain (g) max (g) oven flash lost (g) remain% after lhr remain after 24hrs (g) after 24hrs% ___________ ______ _______ _________ _________ (g) ________ after oven (g) lhr% ____________ ______________ OvenTime 30s 2.910 3.130 0.116 3.085 0.045 61% 3.066 45% 3.019 0% (See) 60s 2.908 3.133 0.119 3.059 0.074 38% 3.022 7% 3.022 0% 120s 2.910 3.133 0.118 3.026 0.107 9% 3.019 3% 3.019 0% _________ 300s 2.880 3.088 0.110 2.980 0108 2% 2.986 0% 2.986 0% ________________________________ A5 ITEM M.P. range (°C) Avg. M.P. °C Low M.P. wax 53-57 55 High M.P. Wax 73-80 77 1000mw PEG 35-40 37 1500mw PEG 44-48 46 4000mw PEG 55-60 57 * S ** * . * * . S S S * * . *. * . * S : * * . * * * * S S * * * S * S.. * * . S. Appendix B B! LTIM -Low Melting Wax Substrate Tova _______ _______ 10 MS: 1 Wax: 18 Heptane _______ _______ Water %(w/w) Water %(w/w) Oven 30s Pan (g) Sample Sample After After Max Solvent Solvent absorbed 24hrs absorbed Max time (g) after oven 1 hr 24 hrs lost max 24 hrs total ________ _______ _______ _______ flash (g) _______ _______ _______ _______ _______ ________ _______ ________ _______ Oven 110 2.880 3.285 3.234 3.164 3.081 3.083 0.051 0.214 0.010 5.1% 0.012 6.2% temp 75 2.909 3.311 3.275 3.193 3.115 3.147 0.036 0.212 0.016 8.6% 0.048 25.4% 2.913 3.286 3.254 3.185 3.109 3.114 0.032 0.197 0.020 11.3% 0.025 14.2% _______ 35 2.909 3.248 3.246 3.222 3.103 3.113 0.002 0.179 0.034 21.2% 0.044 27.5% Average 0.020 11.6% 0.032 18.3% Substrate Tova ________ ________ 10 MS: I Wax: 18 Heptane ________ ________ Water %(wlw) Water %(w/w) Oven 60s Pan (g) Sample Sample After After Max Solvent Solvent absorbed 24hrs absorbed Max time (g) after oven 1 hr 24 hrs lost max 24 hrs total ________ _______ _______ _______ flash (g) _______ _______ _______ _______ _______ ________ _______ ________ _______ Oven 110 2.910 3.354 3.240 3.126 3.132 3.133 0.114 0.234 0.012 5.9% 0.013 6.4% temp 75 2.878 3.279 3.225 3.159 3.085 3.117 0.054 0.212 0.018 9.4% 0.050 26.3% 2.882 3.296 3.256 3.191 3.107 3.119 0.040 0.219 0.030 15.1% 0.042 21.3% _______ 35 2.909 3300 3.256 3.197 3.116 3.127 0.044 0.206 0.022 12.2% 0.033 18.1% Average 0.021 10.7% 0.035 18.0% * . ** S * S. S * * S S S S * . . S. * S S * * . S * * . . *5 * S S S S S S * 5* S S I SS Substrate Tova ________ _______ 10 MS: 1 Wax: 18 Heptane _______ ________ Water %(w/w) Water %(w/w) Oven 120s Pan (g) Sample Sample After After Max Solvent Solvent absorbed 24hrs absorbed Max time (g) after oven 1 hr 24 hrs lost max 24 Hrs total ________ _______ _______ _______ flash (g) _______ _______ _______ _______ _______ ________ _______ ________ _______ Oven 110 2.879 3.312 3.143 3.120 3.134 3.132 0.169 0.229 0.051 24.8% 0.049 23.8% temp 75 2.909 3.332 3.235 3.125 3.124 3.132 0.097 0.223 0.015 7.7% 0.023 11.7% 2.914 3.339 3.275 3.232 3.152 3.169 0.064 0.224 0.037 18.6% 0.054 27.1% ________ 35 2.909 3.371 3.303 3.247 3.125 3.139 0.068 0.244 -0.002 -0.9% 0.012 5.5% Average 0.025 12.5% 0.035 17.0% Substrate Tova ________ _______ 10 MS: 1 Wax: 18 Heptane ________ _______ Water %(w/w) Water %(w/w) Oven 300s Pan (g) Sample Sample After After Max Solvent Solvent absorbed 24hrs absorbed Max time (g) after oven 1 hr 24 his lost max 24 his total ________ _______ _______ _______ flash (g) _______ _______ _______ ________ _______ ________ ________ _________ _______ Oven 110 2.910 3.327 3.116 3.147 3.152 3.152 0.211 0.220 0.045 23.0% 0.045 23.0% temp 75 2.878 3.290 3.120 3.099 3.127 3.129 0.170 0.218 0.055 28.0% 0.057 29.1% 2.883 3.303 3.184 3.104 3.112 3.128 0.119 0.222 0.031 15.5% 0.047 23.6% _______ 35 2.878 3.339 3.234 3.207 3.099 3.127 0.105 0.243 0.003 1.6% 0.031 14.4% Average 0.033 17.0% 0.045 22.5% Substrate EPT _______ _______ 10 MS: 1 Wax: 18 Heptane _______ _______ Water %(w/w) Water %(wfw) Oven time 30s Pan (g) Sample Sample After After Max Solvent Solvent absorbed 24hrs absorbed max (g) after oven 1 hr 24 his lost max 24 his max _________ ________ _______ _______ flash (g) ________ _______ _______ ________ _______ ________ ________ _________ _______ Oventemp 110 3.419 3.820 3.800 3.767 3.634 3.641 0.02 0.212 0.026 13.6% 0.033 17.3% 3.384 3.696 3.688 3.626 3.550 3.574 0.008 0.165 0.019 12.7% 0.043 29.0% 3.384 3.967 3.920 3.857 3.695 -0.047 0.308 0.036 13.0% Crumbled sample lost cohesion _________ 35 3.418 3.769 3.762 3.727 3.607 3.638 0.007 0.185 0.023 14.1% 0.054 32.8% Average 0.026 13.4% 0.043 26.4% * * S. S S * S S S S * S * S S ** . . . S * . . S S S S 55 * . . S S * S S 5I * . . *5 Substrate EPT _______ ______ 10 MS: 1 Wax: 18 Heptane _______ _______ Water %(wlw) Water %(w/w) Oven time 60s Pan (g) Sample Sample After After Max Solvent Solvent absorbed 24hrs absorbed max (g) after oven 1 hr 24 hrs lost max 24 hrs max _________ _______ _______ ______ flash (g) _______ _______ _______ _______ _______ _______ ________ ________ _______ Oven temp 110 3.404 3.778 3.746 3.698 3.603 3.612 0.032 0.197 0.022 12.7% 0.031 17.8% 3.394 3.696 3.680 3.616 3.555 3.578 0.016 0.159 0.018 12.9% 0.041 29.1% 3.438 3.819 3.793 3.746 3.603 3.664 0.026 0.201 -0.015 -8.2% 0.046 25.7% ________ 35 3.400 3.800 3.788 3.746 3.603 3.635 0.012 0.211 0.014 7.5% 0.046 24.5% Average 0.010 6.2% 0.041 24.3% Substrate EPT _______ _______ 10 MS: 1 Wax: 18 Heptane _______ _______ Water %(w/w) Water %(w/w) Oven time 120s Pan (g) Sample Sample After After Max Solvent Solvent absorbed 24hrs absorbed max (g) after oven 1 hr 24 hrs lost max 24 Hrs max _________ _______ _______ _______ flash (g) _______ _______ _______ _______ _______ _______ ________ ________ _______ Oven temp 110 3.418 3.822 3.717 3.645 3.641 3.652 0.105 0.213 0.032 16.9% 0.043 22.7% 3.417 3.736 3.705 3.645 3.591 3.613 0.031 0.168 0.023 15.6% 0.045 30.2% 3.423 3.874 3.830 3.779 3.673 3.693 0.044 0.238 0.037 17.4% 0.057 26.8% _________ 35 3.448 3.897 3.869 3.831 3.660 3.694 0.028 0.237 0.000 0.0% 0.034 16.1% Average 0.023 12.5% 0.045 24.0% Substrate EPT ________ _______ 10 MS: I Wax: 18 Heptane _______ ________ Water %(w/w) Water %(w/w) Oven time 300s Pan (g) Sample Sample After After Max Solvent Solvent absorbed 24hrs absorbed max (g) after oven 1 hr 24 hrs lost max 24 Hrs max _________ _______ _______ ______ flash (g) _______ _______ _______ _______ _______ _______ _______ ________ _______ Oven temp 110 3.434 3.836 3.682 3.643 3.667 3.671 0.154 0.212 0.043 22.8% 0.047 24.9% 3.436 3.742 3.669 3.619 3.600 3.622 0.073 0.162 0.020 13.5% 0.042 28.8% 3.351 3.783 3.648 3.577 3.603 3.604 0.135 0.228 0.048 23.6% 0.049 24.1% _________ 35 3.431 3.800 3.777 3.721 3.638 3.674 0.023 0.195 0.033 18.9% 0.069 39.5% Average 0.036 19.7% 0.052 29.3% * S ** a * S S S S * * * ** . S S * * * * * ** * S * S S S S S SS * I S SI B2 LTD1 -High Melting Wax Substrate Tova _____ ______ 10 MS: 1 Wax: 18 Heptane _____ _______ ________ Water %(w/w) Water %(w/w Oven 30s Pan (g) Sample Sample after After After Max Solvent Solvent absorbed 24hrs absorbed) Max Time _____ (g) oven flash (g) 1 hr 24 his _____ lost max 24 Hrs ______ total _____ 2.878 3.394 3.326 3.287 3.181 3.150 0.068 0.272 0.059 24.4% 0.028 11.7% jven 80 2.880 3.447 3.395 3.346 3.183 3.185 0.052 0.299 0.035 13.2% 0.037 14.0% emp 60 2.885 3.380 3.345 3.304 3.165 3.179 0.035 0.261 0.046 19.8% 0.060 25.8% Average 0.047 19.2% 0.042 17.2% Substrate Tova _____ ______ 10 MS: I Wax: 18 Heptane _____ _______ ________ Water %(W/w Water %(w/w Oven 60s Pan (g) Sample Flash After After Max Solvent Solvent absorbed) 24hrs absorbed) Max Time _____ (g) ______________ 1 hr 24 hrs _____ lost max 24 Hrs ______ total _____ o 110 2.910 3.450 3.272 3.191 3.209 3.220 0.178 0.285 0.044 17.3% 0.055 21.6% \Ten 80 2.909 3.494 3.423 3.389 3.223 3.237 0.071 0.309 0.038 13.7% 0.052 18.8% emp 60 2.917 3.333 3.295 3.251 3.144 3.147 0.038 0.220 0.031 15.6% 0.034 17.1% Average 0.038 15.5% 0.047 19.2% Substrate Tova _____ ______ 10 MS: 1 Wax: 18 Heptane _____ _______ ________ Water %(wlw) Water %(w/w Oven 120s Pan (g) Sample Flash After After Max Solvent Solvent absorbed 24hrs absorbed) Max Time _____ (g) ______________ 1 hr 24 his _____ lost max 24 Hrs ______ total _____ Oven 110 2.881 3.408 3.174 3.190 3.202 3.202 0.234 0.278 0.072 29.0% 0.072 29.0% temp 80 2.910 3.484 3.367 3.242 3.220 3.232 0.117 0.303 0.039 14.4% 0.051 18.9% * S ** . . S. S S * . . S S * S * ** S * S * * . . . . . S ** * S * S S S * S *.. * * S ** 2.885 3.273 3.227 3.176 3.105 3.119 0.046 0.205 0.037 20.1% 0.051 27.8% Average 0.049 21.2% 0.058 25.2% Substrate Tova _____ _____ 10 MS: 1 Wax: 18 Heptane _____ _______ ________ Water %(w/w) Water %(w/w Oven 300s Pan-(g) Sample Sample after oven After After Max Solvent Solvent absorbed 24hrs absorbed) Max Time ______ (g) flash (g) 1 hr 24 his _____ lost max 24 Hrs ______ total _____ O 110 2.910 3.451 3.187 3.232 3.238 3.239 0.264 0.286 0.073 28.5% 0.074 28.8% te 80 2.877 3.455 3.305 3.189 3.270 3.240 0.150 0.305 0.120 44.1% 0.090 33.1% p 60 2.916 3.357 3.260 3.175 3.181 3.190 0.097 0.233 0.057 27.3% 0.066 31.6% Average 0.083 33.3% 0.077 31.2% Substrate EPT _____ ______ 10 MS: I Wax: 18 Heptane _______ _______ Water %(w/w Water %(w/w) Oven 30s Pan Sample Sample after oven After After Max Solvent Solvent absorbed) 24hrs absorbed max Time -(g) (g) flash (g) 1 hr 24 his lost max 24 Hrs ______ max _________ O 110 3.354 3.541 3.517 3.451 3.457 3.459 0.024 0.099 0.015 16.7% 0.017 19.0% 3.383 3.854 3.823 3.791 3.644 3.667 0.031 0.249 0.039 17.4% 0.062 27.7% ______ 60 3.375 3.880 3.868 3.804 3.657 3.681 0.012 0.267 0.044 18.3% 0.068 28.4% Average 0.032 17.5% 0.049 25.0% Substrate EPT _____ ______ 10 MS: I Wax: 18 Heptane ____ _______ _______ Water %(wlw Water %(wlw) Oven 60s Pan Sample Sample after oven After After Max Solvent Solvent absorbed) 24hrs absorbed max Time (g) (g) flash (g) 1 hr 24 his ____ lost max 24 Hrs ______ max _________ o 110 3.437 3.700 3.669 3.619 3.568 3.571 0.031 0.139 0.007 5.5% 0.010 7.9% yen 80 3.437 4.079 4.022 3.983 3.785 3.803 0.057 0.339 0.045 14.8% 0.063 20.8% emp 60 3.440 3.954 3.925 3.883 3.725 3.744 0.029 0.271 0.042 17.5% 0.061 25.3% Average 0.031 12.6% 0.045 18.0% Substrate EPT 10 MS: I Wax: 18 Heptane Water %(w/w Water %(w/w) Oven l2Os Pan Sample Sample after oven After After Max Solvent Solvent absorbed) 24hrs absorbed max Time (g) (g) flash (g) 1 hr 24 his lost max 24 Hrs ______ max _________ * * *. * . ** * * * . * * . * * S ** a * * * * a a S S * I ** * S S S S S S S a.. * . . *5 3.391 3.654 3.572 3.527 3.545 3.552 0.082 0.139 0.030 24.1% 0.037 29.7% Oven 80 3.418 4.042 3.958 3.940 3.759 3.781 0.084 0.329 0.046 15.8% 0.068 23.2% temp 60 3.420 3.931 3.891 3.854 3.706 3.717 0.04 0.270 0M45 18.6% 0.056 23.1% Average 0.040 19.5% 0.054 25.4% Substrate EPT _____ ______ 10 MS: 1 Wax: 18 Heptane _____ ________ ________ Water %(w/w Water %(wlw) Oven 300s Pan Sample Sample after oven After After Max Solvent Solvent absorbed) 24hrs absorbed max Time (g) (g) flash (g) I hr 24 his ____ lost max 24 His ______ max _________ Crumbled sample Oven 110 3.381 3.592 3.487 3.506 3.492 -0.105 0.111 0.011 11.5% lostcohesion temp 80 3.424 4.040 3.923 3.859 3.760 3.790 0.117 0.325 0.045 15.6% 0.075 25.9% ______ 60 3.384 3.877 3.805 3.754 3.662 3.675 0.072 0.260 0.045 19.5% 0.058 25.1% Average 0.034 15.5% 0.067 25.5% * S ** * S * . * S * * * * * I * SI I * * * * S S I * S *.

* . S S S I S S I.. I I *.

Appendix C Cl ____ _____ _________ LTD2 -Low Melting PEG 1500 ____ ____ ____ Substrate Tova System _______ MS: PEG1500: n-Butanol MIX RATIO 10: 1: 18 _______ %(w/w) Water %(wlw) Oven 80°C Pan (g) Sample Solvent Sample Solvent Sample Sample Sample Water 24brs absorbed Max temp (g) max (g) after oven lost (g) after 1 hr after 24 after 4 adsorbed total flash (g) (g) hrs (g) days (g) 24 hrs (g) Oven 30s 2.914 3.025 0.063 3.025 0.000 2.974 2.972 2.970 0.010 21.5% 0.008 17.3% time 60s 2.883 3.024 0.080 2.996 0.028 2.956 2.954 2.950 0.010 17.1% 0.006 10.5% 120s 2.912 2.996 0.048 2.972 0.024 2.965 2.966 2.962 0.018 49.5% 0.014 38.4% _______ 300s 2.880 2.994 0.065 2.929 0.065 2.930 2.928 2.926 -0.001 -2.1% -0.003 -6.2% Average 0.009 21.5% 0.006 15.0% Substrate Tova System _______ MS: PEG 1500: n-Butanol MIX RATIO 10: 3: 15 _______ %(wlw) Water %(w/w) Oven 80°C Pan (g) Sample Solvent Sample Solvent Sample Sample Sample Water 24hrs absorbed Max temp (g) nax (g) after oven ost (g) after 1 hr after 24 after 4 adsorbed total flash (g) (g) hrs (g) days (g) 24 hrs (g) Oven 30s 2.916 3.404 0.236 3.392 0.012 3.252 3.216 3.214 0.048 18.9% 0.046 18.1% time 60s 2.911 3.344 0.209 3.330 0.014 3.221 3.203 3.178 0.068 30.4% 0.043 19.3% 120s 2.923 3.388 0.225 3.344 0.044 3.195 3.181 3.201 0.018 7.3% 0.038 15.6% _______ 300s 2.886 3.355 0.227 3.240 0.115 3.192 3.173 3.170 0.045 18.4% 0.042 17.1% Average 0.044 18.8% 0.042 17.5% * * ** * . : : : :. : : : : * S * S S S *.

* , S * S S * * 4I * S * ** Substrate EPT System _______ MS: PEG1500: n-Butanol MIX RATIO 10: 1: 18 ________ %(wlw) Water %(w/w) Oven 80°C Pan (g) Sample Solvent Sample Solvent Sample Sample Sample Water 24hrs absorbed max temp (g) max (g) after oven lost (g) after 1 hr after 24 after 4 adsorbed max flash (g) (g) hrs (g) days (g) 24 hrs (g) Oven 30S 3.388 3.509 0.069 3.508 0.001 3.477 3.453 3.456 0.013 24.9% 0.016 30.7% time 60S 3.441 3.581 0.080 3.577 0.004 3.540 3.515 3.515 0.014 22.9% 0.014 22.9% 120S 3.388 3.512 0.071 3.500 0.012 3.459 3.456 3.454 0.015 27.5% 0.013 23.8% _______ 3005 3.355 3.538 0.104 3.462 0.076 3.437 3.455 3.457 0.021 27.1% 0.023 29.6% Average 0.016 25.6% 0.016 26.8% Substrate EPT System _______ MS: PEG 1500: n-Butanol MIX RATIO 10: 3: 15 _______ %(w/w) Water %(w/w) Oven 80°C Pan (g) Sample Solvent Sample Solvent Sample Sample Sample Water 24hrs absorbed max temp (g) max (g) after oven lost (g) after 1 hr after 24 after 4 adsorbed max flash (g) (g) hrs (g) days (g) 24 hrs (g) Oven 30S 3.438 3.651 0.103 3.643 0.008 3.591 3.570 3.571 0.022 19.9% 0.023 20.8% time 60S 3.423 3.637 0.103 3.628 0.009 3.520 3.554 3.555 0.020 18.4% 0.021 19.3% 120S 3.390 3.617 0.110 3.603 0.014 3.548 3.530 3.529 0.023 19.3% 0.022 18.4% _______ 300S 3.357 3.580 0.108 3.526 0.054 3.499 3.496 3.495 0.024 20.6% 0.023 19.7% Average 0.022 19.5% 0.022 19.6% * S ** , . 6* S * S S * S S * , *d S I * * * 56 * * * *.

* . * * * I 6 6i * 1 C2 LTD2 -High Melting PEG 4000 Substrate Tova System _________ MS:PEG4000:n-Butanol MIX RATIO 10: 2: 10 ___________ %(w/w) Oven 80°C Pan (g) Sample Solvent max Sample Solvent lost Sample Sample Sample Water 24hrs water emp (g) (g) after oven (g) after 1 hr after 24 after 4days adsorbed 24 absorbed %(w/w) flash (g) (g) hrs (g) (g) hrs (g) ________ total Max 60s 2.911 3.107 0.079 3.066 0.041 3.107 3.046 3.054 0.018 15.4% 0.026 22.2% 120s 2.878 3.046 0.068 3.001 0.045 2.994 2.991 3.000 0.013 12.7% 0.022 21.6% 180s 2.911 3.114 0.082 3.037 0.077 3.051 3.046 3.054 0.014 11.4% 0.022 18.0% 300s 2.881 3.131 0.101 3.034 0.097 3.054 3.049 3.055 0.019 12.6% 0.025 16.6% Average 0.016 13.0% 0.024 19.6% Substrate Tova System _________ MS:PEG4000:n-Butanol MIX RATIO 10: 2: 10 ___________ %(w/w) Oven 80°C Pan (g) Sample Solvent max Sample Solvent lost Sample Sample Sample Water 24hrs water emp (g) (g) after oven (g) after 1 hr after 24 after 4days adsorbed 24 absorbed %(w/w) ________ -______ ______ __________ flash (g) __________ (g) hrs (g) (g) hrs (g) ________ total Max 60s 2.883 3.315 0.174 3.311 0.004 3.211 3.189 3.189 0.048 18.6% 0.048 18.6% l2Os 2.910 3.439 0.213 3.429 0.010 3.319 3.287 3.28 0.061 19.4% 0.061 19.4% 180s 2.913 3.447 0.215 3.417 0.030 3.307 3.307 3.291 0.075 23.6% 0.059 18.6% 300s 2.880 3.583 0.283 3.490 0.093 3.456 3.456 3.382 0.156 37.2% 0.082 19.6% Average 0.085 24.7% 0.063 19.0% * . *. * * * . * . . * * * .* .* * S * * * * * * * r * *S * . * . * S * * )** * . S. Substrate EPT System _________ MS:PEG4000:n-Butanol MIX RATIO 10: 2: 10 __________ %(wlw) Oven 80°C Pan (g) Sample Solvent max Sample Solvent lost Sample Sample Sample Water 24hrs water :emp (g) (g) after oven (g) after 1 hr after 24 after 4days adsorbed 24 absorbed %(w/w) ________ _________ flash (g) _________ (g) his (g) (g) his (g) ________ max max 30S 3.388 3.632 0.098 3.625 0.007 3.571 3.559 3.561 0.025 17.4% 0.027 18.8% 60S 3.396 3.639 0.098 3.636 0.003 3.598 3.568 3.571 0.027 18.6% 0.030 20.6% 120S 3.448 3.707 0.104 3.699 0.008 3.658 3.631 3.633 0.028 18.4% 0.030 19.6% 300S 3.430 3.689 0.104 3.661 0.028 3.652 3.618 3.618 0.033 21.6% 0.033 21.6% Average 0.029 19.0% 0.030 20.2%

Claims

CLAIMS: 1. A liquid desiccant composition comprising a molecular sieve.
2. A liquid desiccant composition comprising a desiccant, an adhesive and a carrier solvent.
3. A composition according to claim 2 wherein the desiccant comprises a molecular sieve.
4. A composition according to claim 1, .2 or 3, wherein the molecular sieve comprises an aluminosilicate. * .** * * *
A composition according to any one of claims.2 to 4 wherein the adhesive *..* : *,comses a wax and/or a polyethylene glycol. **.*
6. A composition according to claim 5 wherein the wax comprises paraffin wax. **.*
A composition according to any one of claims.2 to 6 wherein the carrier solvent ****..comprises an aliphatic solvent.
8. A composition according to claim 7 wherein the solvent comprises a heptane or a butyl alcohol.
9. A composition according to claim 8 wherein the solvent comprises n-heptane or n-.butamol.
10. A composition according to any preceding claim wherein in use the composition provides 10% relative humidity (RH) or less within 1 hour. 30..
11. A composition according to any one of claims 4 to 10 wherein the aluminosilicate comprises a zeolite.
12. A composition according to claim 1, or any one of claims 3 to 11 comprising a molecular sieve with a pore size of Grade 3A, 4A, 5A or 10,4.
13. A composition according to claim 12 wherein the pore size is Grade A.
14. A liquid desiccant composition according to any preceding claim comprising a molecular sieve comprising an aluminosilicate compound; paraffin wax as adhesive and n-heptane as solvent.
15. A liquid desiccant composition according to any one of claims Ito 13 comprising an aluminosilicate compound; a polyethylene glycol as adhesive and n-butanol as solvent. * S **::..
16. A composition according to claim 14 comprising, by weight, 10 parts molecular * : 15 sieve;lrom ito 10 parts of wax adhesive; and from 10to2O parts of solvent. *5**17. A composition according to claim 16 comprising 1-2 parts of wax adhesive and 15-18 parts of solvent. ***SS.....18. A composition according to claim 15 comprising, by weight, 10 parts molecular sieve; from ito 10 parts of PEG adhesive; and from 10 to 20 parts of solvent.19. A composition according to claim 18 comprising 1-4 parts of PEG adhesive and 18 parts of solvent.20. A substrate or product comprising a liquid desiccant composition according to any preceding claim.21. A substrate or product according to claim 20 comprising a dried form of the said liquid desiccant composition.22. A substrate or product according to claim 20 or 21 comprising an Early Pregnancy Test Kit (EPT) or an In-Vitro Diagnostic Kit (IVD).23. A process for applying a liquid desiccant composition to a substrate, which process comprises applying a composition according to any one of claims 1 to 1 9 to a substrate, and drying.24. A process according to claim 23 wherein the drying step is performed at from 60°C to 80°C.25. A process according to claim 23 wherein the duration of the drying step is from 120 to 150 seconds. S... * . III I * I *5** * *. * S S S... S... * I S...SS.....S S