Polyten & Marcus Oil Waxes

Polyethylene waxes are low molecular weight ethylene derived polymers supplied in different forms including micronized and oxidized polyethylene wax used in a wide variety of applications including adhesives, candles, plastics and coatings.

In addition to the Polyethylene waxes, Polyten manufactures and distributes additives such as Anti-Oxidants, UV Stabilizers, Calcium Carbonate Masterbatch and Pigments.

For more information about Polyten & Marcus Oil waxes, contact:
a.talebi@polyten.ca  |    (647)-403-1497

Asphalt

The Marcus homopolymer polyethylenes, with their ideal combination of hardness, high melting point, and exceptionally low melt viscosity are perfect additives, at rates of 3–5 %, to bitumen roofing and sheeting compounds.

In these products, bitumen is blended with thermoplastic elastomers of varying types (amorphous polyolefins and SBS).  The inclusion of these polymers results in a dramatic increase in viscosity and a consequent disruption of flow characteristics.  The incorporation of an additive amount of a Marcus homopolymer wax brings about a significant improvement of flow during hot torching procedures, stimulating the formation of a smooth and high gloss coating with added water repellency properties.

Cable filling

The Marcus homopolymer waxes have an excellent combination of characteristics to provide powerful gel forming aids for oils and polybutenes.

The major properties are:

• Highly crystalline
• Excellent heat stability
• High melting
• Good gel forming nature at 5 – 10% level
• Inert
• Good electrical properties

Electrical and telecommunication cables are manufactured with a filling/flooding compound packed inside them for providing water and gas tightness.  These compounds must have a good stability to the high shear forces which occur during manufacture and which could cause breakdown of the compound consistency.  This consistency must also be maintained over a wide temperature range and there should be no migration.

The Marcus homopolymers as high performance additives possess the properties necessary to formulate stable and heat resistant gels and being highly crystalline, have little tendency to migrate.

Coatings & Paints

The nature of the characteristics of the Marcus polyethylenes are harnessed in dispersion, emulsion and micronized forms to great effect for a variety of applications in this field, the prime reasons for use being:

• Mar, scratch and abrasion resistance
• Slip modification
• Rheological modification
• Flatting

The presence of fine particles of a hard polyethylene, both at and protruding from the surface of a film, reduces the coefficient of friction.  This means that other surfaces do not directly abrade the surface, and thus mar, scratch and abrasion resistances are improved.  The additional slip created also provides an external lubricating action, useful in finished metal which subsequently has to undergo forming.

The addition of a dispersion to a varnish or lacquer reduces the gloss, having a flatting action.   The extent of flatting depends upon many parameters and is not as great as with a colloidal silica.  However, a polyethylene dispersion has very food transparency and smoothness, giving a soft silky feel.  Most commonly the two are used in combination.

The polyethylene dispersions possess thixotropic characteristics.  Consequently they impart good anti-settling and anti-sagging feature to pigmented finishes.  In this respect, the oxidized grades are of particular value and these rheology properties make them a goal choice for aluminum flake control in automotive base coat lacquers.

Colour Concentrate

These are compounds to facilitate the colouring of a wide variety of plastics, the pigment being bound up in a concentrated form as an easier to handle and non-dusting form.  Which facilitates dispersion in many plastic compounds.  The pigment loading can be as high as 60% for inorganics (which are easier to disperse), and 25 – 50 % for organic pigments and carbon black
Concentrates are normally composed of a carrier polymer of either the same type as that to be colored, or of a type which has good compatibility with the one to be colored.  This is important because if the polymers are not compatible with each other, there is a diminution of the mechanical properties of the finished article.   The other components are the pigment and a wax.
There is a multitude of formulations, each with different ratios, depending upon the production method, specific pigment structure and known degree of difficulty in dispersing.  With these variables in mind, the amount of wax which is employed can range between 5 – 20%, though the norm is around 5 – 10%.  Normally, the concentrate can be let down to color in levels from 1-5 %.  Thus, the quantity of wax in the final article falls between 0.2 – 0.5%, when it is not detrimental to the mechanical properties.
The Marcus homopolymer polyethylene waxes, being of a chemically inert character and possessing excellent thermal stability and low melt viscosity, are well suited for the production of these concentrates, not only for the colouring of polyolefins, but also for a broad spectrum of other polymers.  Their low melt viscosity results in excellent wetting out of the pigment, which together with the high shear forces developed during processing, results in the breaking down of pigment agglomerates.  This subsequently results in a very efficient and uniform distribution of the pigment throughout the polymer being coloured.

In summary, the necessity and advantages gained in utilizing the Marcus performance polyethylene waxes are: 

• Better wetting characteristics
• Easier processability
• Superior dispersing power
• Higher pigment loading
• Excellent thermal stability
• Improved polymer flow properties

There is a variety of methods available for the production of colour concentrates, encompassing batch preparation by milling and high intensity mixing procedures to continuous techniques via internal mixing and extrusion.

Some of the methods for the production of color concentrates are:

1. Milling
The components are compounded together on a two roll mill with the temperature maintained at a low enough temperature in order to ensure that the blend has a sufficiently “workable” viscosity to provide adequate mixing and shear. Cycle times are relatively long.

2. High Intensity mixing
The components are processed together and heat develops from the friction generated by mixing. This causes the wax to soften and wet / adsorb the pigment and subsequently coat the carrier polymer particles. Following this the crude concentrate is extruded on single or twin screw equipment and strand granulated. In general, processing via a twin screw would require a lower wax concentration than by single screw. 
This method also constitutes the basis for preparing non-dusting pigment concentrates (without polymer).  
Related to this method is the production of flushed colours in which wax is melted in a blend with a pigment press cake and during processing the water separates and the pigment is dispersed and coated with wax. MARCUS polyethylenes are particularly suited for this as their exceptionally low melt viscosity provides excellent wetting behaviour.

3. Internal mixing (Banbury)
All components are processed together and very high shear forces are developed in a very short time. Following this the crude concentrate is then sheeted and diced prior to extruding for strand granulation.

4. Continuous internal mixing
A continuous variation of the previous method employing Buss or Farrel equipment and particularly suitable for large scale operations.  

Corrugated board

There are several treatments for board.  One is impregnation which is an internal saturation process.  For this, the wax melt has to be very low in viscosity and the temperature of application is normally 80 - 90º C.

Another application is coating which provides improved surface properties, including abrasion resistance.  These coatings are based on paraffins, which have small amounts (10%) of an EVA, added to provide toughness and flexibility.  A small amount  (about 10% of Marcus 200) of higher melting and harder wax is also incorporated to provide better abrasion resistance.

The only emulsion type of value would be anionic, as the coating would deposit only water insoluble material and the amine would volatilize.  A nonionic would not be of use as the nonionic surfactant, which is waster soluble/sensitive, would stay in the film.  It would also tend to destroy the strength of the board.

Dispersions (Non - Aqueous Based)

Many application (primarily for inks and coatings) for the Marcus polyethylenes dictate that these products are suitably dispersed in solvent/binder vehicles as fine particles for convenience of use.  These can be aliphatic, aromatic, polar and vegetable oils as well as blends thereof.
There are a number of techniques which can be employed, these being:

1.  Solution - Crystallization
This method consists of preparing a hot and clear solution of the polyethylene at a concentration of 25-40%.  This solution is then shock cooled under high shear mixing with the remaining cold solvent, in order to crystallize the wax as rapidly as possible to obtain a final solids content in the range 10 - 15%.  There are a variety of ways to effect this shock cooling procedure.  This method in general produces fine particle sized dispersions, which exhibit varying degrees of structures, depending upon the individual wax and the solvent and production parameters used. 
In employing this procedure a knowledge of the nature of polyethylenes and the influence of this upon the behaviour in solvents is required.  Polyethylenes are composed of fractions of differing molecular weights and degrees of branching.  Each has different solubility characteristics and thus the time to reach a complete state of dissolution is variable.  Therefore, it is essential that in preparing a solution, adequate time be allowed to elapse so that a "clear" solution be obtained, in order to insure that the polyethylene has been truly dissolved.  Failure to do this can result in the presence of gels in the resulting dispersion.  It is also important to determine the cloud point of the solution which is the temperature at which the polyethylene, its concentration and the nature of the solvent.  When preparing the dispersion, optimum and reproducible results are obtained when the temperature of the hot concentrate is 5 - 10 DEG C above its cloud point prior to the addition of cold solvent, to effect the shock cooling stage.

2.  Mechanical
This typically effected with the polyethylene at a concentration of 20 -30% being ground with solvent/binder in a ball or pebble mill.  This cold milling procedure, although giving reproducible results, is a lengthy and time-consuming process to break the polyethylene down to the desired fineness.

3.  Solution - Mechanical
The polyethylene wax, at a concentration of 20 - 30%, is dissolved in the solvent (normally mineral oil) and then poured onto a chilled triple roll mill when the dispersion is formed. The particle size is frequently reduced further by subsequent milling.

4. Micronized Pre-Dispersions
The micronized polyethylenes theoretically may be directly stirred into an ink or coating as they are already in a fine form.  However, the surface area of a micronized particle is very large and requires an effort for effective wetting.  Consequently, it is general practice to make a pre-dispersion of the product in solvent prior to addition.  These dispersions can be as high as 50% solids.  Another reason for preparing a pre-dispersion is to avoid a dusting problem which is endemic to this class of product.

Emulsions (Water based dispersions)

These are stable and fine particle sized (typically 0.05 microns) dispersions of oxidized polyethylene wax (MARCUS 3400 & 3500) in water. The stability is attained by the inclusion of a surfactant into the wax during the emulsification procedure. There are three main types of emulsions used in practice and these are:
Anionic
The surface active portion has a negative charge and is normally a fatty acid in combination with an amine. The acid commonly employed is oleic acid and there are many amines which can be used and differing ones are chosen depending upon the application. Among the most used are Morholine, Amino-methyl-propano (AMP) Diethylaminoethanol (Diethylethanolamine) and Ammonia (25-28%).
Non-ionic
This class of emulsion has no charge and an ethoxylated nonyl phenol or alcohol is the most suitable choice (with an ethoxylation degree of 9-10 moles EO) although a small amount of saponifying agent is also incorporated. This is usually potassium hydroxide.
Cationic
These emulsions have a positive charge and as a consequence, exhaust very well onto negatively charged surfaces. The preferred type of surfactant is an ethoxylated amine ( with an ethoxylation degree of 2 moles EO ) and it is used in combination with a small amount of acetic acid. 
Another type of surfactant which can be used and has very useful properties is an imidazoline but again, must be used in combination with acetic acid.
There are a number of different ways of preparing polyethylene emulsions, the most widely used being the wax to water method and the pressure emulsification technique. 

Wax to water emulsification

a.)  Anionic

The oxidized MARCUS 3400 or 3500  and oleic acid are mixed and melted together the temperature being adjusted to within the range 125-130ºC. The amine is stirred in and the blend well mixed for a short time in order to allow the amine to react with the fatty acid and oxidized polyethylene. It can be advantageous during this step to let the melt cool somewhat in order that the amine does not volatilize too much.  While the wax melt is being processed, soft or demineralised water is heated to a temperature of 95-98ºC.  The temperature of the wax melt is again adjusted to 125-130ºC and then poured in a slow steady stream into the well stirred water. In effecting this, it is not necessary to have high speed or high shear mixing and an ordinary propellor or turbine design is perfectly adequate providing, that it is so placed as to give a thorough mixing and circulation action. It is also beneficial to place it so that a small vortex is created at the surface and the wax melt added at this point is very efficiently and rapidly dispersed.

Following the wax melt addition, the emulsion is cooled ( under continuous stirring ) as quickly as possible to room temperature. Cooling may be  made through use of a double jacketed vessel or, more preferably by passage through an external heat exchanger. It is important that rapid cooling is applied with stirring since if left to cool slowly and without stirring, a “crust” is formed and also, in addition, the emulsion has a pronounced tendency to display instability and creaming.

After cooling, the addition of a bactericide is made to protect the emulsion from subsequent contamination and bacteriological attack which can cause discolouration, gelling, separation and high odour to develop.

As a final step the emulsion is filtered as it is inevitable that some foreign matter and oversized particles are present.

The maximum solids content which can be comfortably attained is 25%.

b.) Non-ionic
The procedure is essentially the same as for anionic. The oxidized wax and surfactant are mixed and melted together and the temperature adjusted to 125-130ºC.

While this is being done, a potassium hydroxide solution in monoethylene glycol is prepared. This is done by heating 1 part of the KOH with 2 parts of glycol ( the dissolution process is violent and consequently heating should be gentle ). This solution is dark yellow brown and becomes viscous upon cooling. Therefore, for addition to the wax melt it is recommended that it is added hot. An alternative means of adding the KOH is as a solution in water. However, this is not advised as there is a real risk that when added, and too quickly, boiling occurs and the wax melt overflows the vessel.

As for anionic preparation, water is heated to 95-98ºC. The KOH solution is stirred into the wax melt and mixed well for a short time to ensure that the wax is correctly saponified. Following this the emulsion is prepared as described above.

The maximum solids content which can be attained is slightly higher than with anionics and is 30%.

c.) Cationic
The same procedure is basically followed as for those above. However, cationics are difficult to prepare by this technique due to the low boiling point of acetic acid ( 118ºC ) and much is lost during the mixing stage and this results in poor quality emulsions. The pressure method is advised as this is carried out in a closed vessel.

Pressure emulsification

In this method, emulsification is carried out in a closed vessel. It has many advantages over the wax to water route in that it offers:

• Greater uniformity and consistency of production.
• Production time / batch size is quicker / larger
• Higher solids content easier to produce
• Essential for some formulation types

In pressure emulsification there are two techniques which can be adopted, these being the “direct” and “indirect”methods. The latter is by far and away the better procedure but requires, however, two vessels rather than a single one as in the case of the first procedure.

The reactor should be of stainless steel and double jacketed for steam heating and water cooling. It should be fabricated sufficiently thick to withstand an internal pressure of 5 kgs / cm2 (approximately 65 psi ) and fitted with pressure and temperature recorders together with safety and drain valves. The stirrer can be of the propeller, turbine or anchor design and it is not necessary for high speed / shear.

a.) Direct

This method is suitable for the preparation of non-ionic emulsions but not, for good quality anionics or cationics.

Water is charged to the reactor and stirring is commenced. The other ingredients are charged and the order has no significance. Heating is begun and the filling port is closed. Heating is continued until a temperature of 125 -130ºC is attained. This condition is maintained for a period of 15 -30 minutes under continuous stirring. Heating is stopped and cooling is effected until ambient temperature is reached. The cooling is preferably done by evacuating the contents (whilst hot and under pressure) directly to atmospheric pressure via an external heat exchanger of a coil or plate design. This shock cooling step ensures a finer particle sized emulsion and also enables a wider margin of error to be built into the procedure.

b.) Indirect

In this procedure the same means is followed except that a portion of the water charge is omitted such that a high solids concentrate is initially processed. Following a maintenance of the temperature for 15 - 30 minutes, the second water charge is injected at a controlled rate into the bulk of the concentrate, whilst it is still under pressure, at just below the boiling point of water. It is better if the temperature of the injected water is at the same temperature as the concentrate although, this necessitates a second pressure vessel. Following this, the mixture may be cooled immediately and the preferred means is via an external heat exchanger.

In general, this method allows greater lot to lot reproducibility and gives better results for all emulsion types but particularly for anionics and cationic.  

Fruit Coating

An application for the Marcus oxidized grades 3300,3400 & 3500 emulsion (essentially anionic formulations with highly volatile amines) is predominantly to citrus fruit (oranges, lemons, grapefruit etc.).

The fruit is harvested in the green (unripe) state and is washed to remove insecticide and fungicide residues. In this process the natural waxes in the skin are removed. It is imperative that these natural protectants are replaced, otherwise the fruit can lose up to 50% of it's weight within a few weeks. At the same time, due to the loss of water, there is an interference with the chemical reactions which are responsible for the development of a full flavoured juice.

The polyethelene emulsion is used in combination with an alkali soluble resin solution and variable ratios are formulated to maintain the optimum benefits for the requirements of the many different species.
Application is by dipping, brushing or spraying and the dosage rate is about one litre (of a 15-20% solids coating) per ton of fruit.

The key characteristic of the oxidized polyethylenes used in this application are related to the density of the wax, which in turn has a significant influence upon the barrier properties (permeable to gases thereby allowing the fruit to ripen under the coating and impermeable to water vapour transmission). The higher the density the better these features are. The MARCUS 3400 & 3500 with densities of 0.96 have an unsurpassed efficiency in this application, the prime advantages being:

• Excellent barrier properties.
• Reduced shrinkage.
• Provision of high gloss to the coating.
• Hard, high melting and non tacky.

Hot melt adhesive

These are predominantly blends of an EVA copolymer together with a tackifying resin and a hydrocarbon wax. The EVA is the backbone of the formulation and provides the strength in terms of the mechanical properties, film forming nature, flexibility and cohesion. The tackifying resin (there are numerous types with varying chemical structure) delivers the tack at the application temperature, with ultimate adhesion and improvement in substrate wettability.

The wax is a key element of the blend and is primarily employed in fast packaging and bookinding applications. Its function is to modify a number of critical application and performance characteristics. While there is a broad spectrum of ratios for the formulations, a typical example would be:  

Percent
EVA (28% VA, 400 MI) — 40
Tacifying resin — 30
Wax — 30
Antioxidant — 0.5

The Marcus low molecular weight polyethelene homopolymers 200,300,500, and 4040 are ideally tailored in structure for use for hot melts due to their:

• Low molecular weight (Mn = 1100).
• High crystallinity (Approximately 70 - 75%).
• Narrow distribution (Mw / Mn = 1.2 - 1.5).
• Exceptionally low melt viscosity (10-60 mPas at 149°C).

These features are essential for the high performance additive function they possess and are crucial in maintaining good compatibility in a diverse range of formulations. Their attributes may be summarized as:

• Reduction of blend viscosity.
• Shortening of setting time.
• Improved wettability.
• Greatly improved heat resistance.
• Diminished blocking tendency.

It is suitable, in some instances, to incorporate a high performance MARCUS polyethylene as the sole wax component, or to completely supplant Fischer-Tropsch wax. However, a combination of paraffinic and microcrystalline waxes is the norm in order to meet specific application requirements. In this respect it is to be noted that the highly crystalline and high melting MARCUS polyethylenes have a far greater, more dramatic and positive influence than any of the other waxes upon:

• Reduction of setting time.
• Improvement of heat resistance.

Hot Melt Coatings

These are coatings comprising very high levels of wax (mainly paraffin) together with an EVA and LDPE (or blend) and applied by curtain coating, for example, to corrugated board.
The Marcus homopolymers are ideal components for use in this application due to their combination of inherent property parameters.Thus, their high melting points and hardness coupled with a very low melt viscosity aid in achieving coatings with vastly improved characteristics. Improvements which can be obtained are:

• Better blocking resistance.
• Greater hardness and scuff resistance.
• Improved appearance.
• Superior barrier properties.
• Resistance to grease and water.
• Augmented strength (adhesion and cohesion)

Hot melt road marking

These compounds are blends of a thermoplastic resin together with a plasticizer, extender, aggregate, glass beads and pigment plus other additives to enhance performance.
The Marcus polyethylene homopolymers possess a unique combination of high melting point, hardness, and extremely low melt viscosity. Consequently, they rank as perfect high performance additives for attaining a dramatically improved quality in a HMRM compound. The benefits to be secured come from an addition level in the range of 3-5% (on total formulation).

The principle features improved are: 

• Lower viscosity and application temperature.
• Increased softening point.
• Superior abrasion resistance.
• Improved wetting characteristics.
• Facilitates sprayability.
• Attainment of thinner, sharper markings.
• Good black marking resistance.

Polishes

A major use of the MARCUS oxidized polyethylenes 3400 & 3500 in emulsion form (principally non-ionic emulsion) is in drybright and buffable polishes for floors.
These products, of which there are many formulation types, are based typically upon acrylic polymer emulsions which can comprise up to 80% of total in a drybright recipe, together with an alkali soluble resin solution (10%) and which functions as a leveling agent. In addition there are small amounts of a plasticizer to ensure a completely film forming nature, as well as a coalescing aid and a wetting agent.
In semi and fully buffable polishes the oxidized polyethylene is normally incorporated as a lesser ingredient together with other waxes having superior buff-ability characteristics. The polyethylene improves the gloss and modifies the slip and durability aspects of the polish. The solids content of a polish is usually about 15% and thus the polyethylene concentration (on a solids basis) to obtain all the main fold high performance advantages is in the range 0.5 - 1.0%.
The MARCUS 3400 & 3500 products are readily emulsified to give very fine and stabilized particles which are lamellar and rhombic in habit and the size in a well formulated emulsion in the region of 0.05 microns average. During the course of drying a preponderance of the particles gravitate to the surface and it is this phenomenon which helps to bring about the valuable modification advantages which are summarized as follows:

• Modification of surface slip parameters. 
• A major contributor to gloss level.
• Durability.
• Good rub and scuff mark resistance.
• Improved resistance to dirt pick up.

Polish (Solvent liquid and paste)

The Marcus homopolymers with their hardness and high melting point, together with the gel forming power in solvents, are of major significance in the formulation of paste polishes for floors, cars and furniture.
A paste would typically have a wax content level of 20-25% and of this 2-4% (depending upon formulation type) would be a homopolymer polyethylene. The main functions are to bind the solvent and impart a smooth gel structure which maintains the same consistency over a wide temperature range. This aspect is one for which the MARCUS products are suited in hot climate regions since they provide excellent heat stability. Also, possessing high melting points, the pouring temperature of the paste is elevated again, thus leading to ease of production in high ambient temperatures.
The same principle is applicable to solvent liquids in which the level of homopolymer wax required is in the range 0.5-1.0%. It adds heat stability to the fluid dispersion eliminating phase separation where high temperatures persist. 

Polyolefins

The Marcus series of polyethylene homopolymers are fully compatible with polyolefin polymers. Addition levels greater than 5% are not recommended as the mechanical properties of the polymer are impaired. Also, the end application characteristics such as sealability of film is diminished. In general, the polyethylene waxes act to decrease the "viscosity" of the polymer, that is, increase the melt index. This has the effect of improving the flow characteristics. Also, a fall in the power requirement occurs in converting operations. The MARCUS polyethylenes being of a highly crystalline nature have no tendency to migrate. In principle, these polyethylenes do significantly improve the processability of polyolefins and the potential exists to boost output. However, there is no influence upon reducing the melt fracture tendency of narrow molecular weight distribution polymer once the critical shear rate is exceeded. 

Printing Inks

A major application area for which the Marcus polyethylenes are well suited when in the appropriate form (dispersion, micronized, and emulsion) is for addition to letterpress, lithographic, screen, gravure and flexographic inks. Also, particularly for the micronized grades, in overprint lacquers / varnishes.
The nature of the wax for addition to printing inks is very important as it has to be of the correct structure, molecular weight and distribution in order to have a regular and fine particle size, and also possess adequate hardness to give optimum results. For example, if the structural features do not have the right balance, the particle size will be too large which will lead to an unacceptable reduction in film gloss, resulting in poor performance, particularly in offset inks where the film thickness is around 5 microns. Further, if the wax is too hard then the inherent brittleness can give rise to a powdering problem.
The MARCUS polyethylenes have a very good balance of properties which single them out for imparting valuable high performance attributes in inks whether it be from dispersion or from micronized and emulsified forms. The optimum results are secured with an addition level as low as 0.5% (on total ink solids).

Broadly, the advantages are:

• Rub resistance improvement.
• Slip and anti - blocking properties.
• Minimum gloss reduction.
• Tack reduction.
• Reduced smudging tendency.
• Better abrasion and scratch resistance.
• Modification of rheological characteristics.

PVC Compounds

PVC is a polymer with very useful properties and for processing it requires the addition of a stabilizer system, together with lubricants, of both internal and external.
PVC compounds are formulated for rigid and flexible applications and are adapted to a number of processing methods covering extrusion, injection and blow molding, as well as calendering. These techniques encompass the use of PVC in the fabrication of pipes, profiles, bottle, sheet and jacketing for wires and cables.
The MARCUS polyethylenes, both homopolymer and oxidized grades, are highly efficient lubricants for PVC compounds and each family has a specific function. The homopolymer grades (200, 300, 500 & 4040), being completely non polar and composed mainly of linear chains, are essentially incompatible with PVC. Consequently, they possess a very strong external lubricating power and have a pronounced influence upon inter-particle and melt-wall lubrication, and hence, prolong gelation time. Their efficiency is such that only small dosage rates are needed, which vary from 0.1% to 1.0%. The addition level is dependent upon the stabilizer system in play, the design parameters of the specific processing equipment, and the presence of other lubricants. Frequently, the inclusion of a high performance MARCUS homopolymer has a synergistic influence on the other external lubricants which can lead to an overall lower lubricant concentration being required, resulting in consequent cost savings.
The MARCUS oxidized grades have functional polar groups (carboxyl, hydroxyl, and ester), and although external in action also have a distinct internal lubricating action. Thus, they act to reduce the gelation time and are, like the homopolymers, effective at low incorporation levels, between 0.1 - 0.5%. They are of outstanding value in tin and calcium / zinc stabilized systems and find use in rigid and flexible clear articles. Frequently these oxidized polyethylenes are employed to there best effect in combination with the homopolymers to obtain the desired compound behavior in increasing or decreasing the gelation time to fit the design parameters of the processing equipment.
Although the levels of incorporation of wax are small, there is an accentuation of the high efficiency of lubrication as one of the virtues of wax.

This aspect along with other key advantages highlight:  

• Highly efficient lubricants by all conversion means.
• Excellent filler and modifier dispersants. 
• Superb release agents.
• Significantly improve surface finish.
• Ease and speed processing rates.

Release, Lubricant & Sizing

The MARCUS oxidized polyethylenes 3400 & 3500, when deposited on a substrate from emulsion, have inherent and highly efficient lubricating and release properties. These are harnessed as high performance components of processing aids in a number of applications.
As release aids they are very effective in the die casting of Al, Zn and Mg alloys due to their high melting points and burning off features. They are also used in the mold release of polyurethanes and in the forming of concrete.
In the glass industry their lubricant function plays an important role as a component of a treatment for the reduction of breakage when newly formed thin walled and highly fragile bottles come off the production line, there being a slippage action rather than an impacting one when the bottles contact each other. The same lubricating efficiency also applies in the treatment of glass fibre as it is produced. The application of the polyethylene emulsion in this instance allows the fibre to be immediately wound up without breaking.  

Rubber Processing

The Marcus homopolymer polyethylenes have a unique and tailored combination of physical and chemical characteristics, which coupled with their excellent compatibility features and chemical inertness, makes them outstanding high performance additives for the processing of natural and synthetic elastomers.
Their nature provides an extremely effective lubricant function with minimal detrimental influence upon curing rates and mechanical properties. Consequently, when incorporated at levels between 2 - 10 % (depending upon the the extent of filler loading), they are highly efficient in action no matter what the processing method, whether it be milling, calendering or an internal mixing operation. Equally, there are benefits to be secured in subsequent extrusion and molding procedures. For convenience of use the polyethylenes are available in pastille and powder form, the latter providing ease of dispersion.

A summary of the prime advantages of these polyethylenes in compounding with natural and synthetic elastomers are:

• Compatibility with elastomers.
• Good lubricant / release action from equipment.
• Excellent flow properties (lower Mooney viscosity).
• Easily dispersible.
• Chemically inert with good electrical properties.
• No detrimental influence upon curing rate.
• Minimal effect upon mechanical properties.
• Improved filler dispersion.

Textiles

Oxidized polyethylenes, MARCUS 3400 and 3500 are widely utilized as components of finishes for textiles, primarily in cotton and cotton - synthetics treatments.
These grades in emulsion form and when suitably formulated as non-ionics and cationics have good compatibility with the other ingredients, and also possess excellent stability in the presence of electrolytes and under a wide variety of differing pH conditions.
Typically, a non-ionic or cationic emulsion is blended with a finishing resin and metallic salt catalyst. The application to the fabric is through addition to a padding bath to achieve a wet pick up of 50%. The fabric is subsequently dried and subjected to a curing step. The amount of polyethylene added to secure the optimum benefit is in the range 0.2 - 0.5%.

The advantages attained, mainly as a result of the high performance lubricant characteristics of these grades are:

• Improved tear strength.
• Excellent abrasion resistance.
• Effective softening action.
• Reduced needle wear and cutting.
• Permanence to washing.

Wax Blends

The MARCUS series of homopolymers have very useful physical and chemical characteristics making them compatible with a broad spectrum of other waxes and upgrading the features of other types, notably, paraffin wax. These benefits are frequently secured at low addition levels without modifying the other positive features of the paraffin.
A MARCUS homopolymer blended at a level of 3 - 5% into a paraffin wax will significantly boost the softening point and hardness of the latter without having any detrimental effect upon the melt viscosity.
These advantages are of value in the modification of paraffin wax for a number of applications such as have already been outlined but also in the formulation of crayons and candles.

To summarize, the benefits which may accrue are:

• Boosting of softening point and hardness.
• Low melt viscosity maintained.
• Gloss and opacity.