KEZADOL GR

Kezadol GR should be used in order to prevent blisters and porosity in the following rubber processes.
Kezadol GR is used Low pressure curing in the cable industry.
Kezadol GR is used in compounds cured in heat transfer fluids.

CAS Number: 1305‑78‑8 (this is for calcium oxide)  
EC / EINECS Number: 215‑138‑9 (for CaO) 
For Kezadol GR, the main active component is calcium oxide (CaO). 
Since Kezadol GR is a granulated mixture rather than a single pure chemical, the formula and molecular weight correspond to CaO itself:
Chemical formula: CaO
Molecular weight: 56.08 g/mol

SYNONYMS:
Kezadol GR, Kettlitz Kezadol GR, Calcium oxide desiccant granules, Kezadol GR, Kettlitz Kezadol GR, Calcium oxide desiccant granules, Calcium oxide (CaO), Calcium oxide, Calx, Calcium monoxide, Caloxol W 3, Calcia, Calxyl, Rhenosorb C, Rhenosorb F, Desical P, Caloxol CP 2, Burnt lime, Calcia (CaO), Airlock, Quicklime (CaO), CML 31, Bell CML(E), CML 21, CML 35, Vesta PP, QC-X, Bell CML(P), Caloxal CPA, CSQ, CML 35S, E 529, FCA 8A, F Raimu 1300D, F Raimu 900K, Nanotek CaO, Mikuronraimu, NanoActive CaO, NanoActive CaO Plus, Calciogreen, Caltrac, KSX, Rhenogran CaO 80, Bell CML 41, Chelan, Power-Ca, Moisutoppu 10, Borumikku, Vesta 20, NanoActive Calcium Oxide, Shell Lime HTO, Fishcal, CAC 20209A, Rhenofit F, Moisutoppu 20, Rhenofit C, Stomilex, Vesta QCX, CA 602, OM 1, OM 1 (pigment), Polycal OFT 15, DryPaste S 1, Hyper Expan M, Nekafin 2, Polycal O 5325, Polycal OS 325, Caloxol CP 2HU, CaO, CL 90Q90, CaO WFK Super 40, CaO 80, UPC-B 01, JYQ-S 02, F Raimu 1300K, Calcium oxide (CaO), TK 107, Rapidquell Quicklime CL 90Q, Vesta 18, WKF 40, HAL-G, Seisekkai J 1P, Kezadol PCI, HAL-J, 12610-14-9, 60873-85-0, 104624-96-6, 245321-52-2, 2641773-61-5

Kezadol GR is a granular desiccant and acid absorber with high calcium oxide content, designed for moisture control, improved rubber compound quality, and protection of curing equipment from acid and corrosion.
For Kezadol GR, the main active component is calcium oxide (CaO).

Since Kezadol GR is a granulated mixture rather than a single pure chemical, the formula and molecular weight correspond to CaO itself.
The remaining part of Kezadol GR consists of coatings or dispersing agents, which are proprietary and not publicly disclosed.
These do not significantly change the chemical formula of the active CaO component.

Kezadol GR is a soft 81.5 % calcium oxide granule coated with special dispersing agents, for use as a desiccant in rubber compounds which are cured on micro-wave systems, LCM or hot air.
Kezadol GR is a water‑scavenging (desiccant) additive used in rubber compounds.

Kezadol GR’s designed to absorb moisture present in uncured rubber mixes (especially from fillers), thereby preventing defects like blisters and porosity during curing processes such as microwave, LCM (liquid curing medium), or hot air vulcanization.
In addition to moisture absorption, Kezadol GR acts as an acid absorber, reducing corrosion from HCl, and can help inhibit nitrosamine formation in rubber compounds.

Kezadol GR is a soft 81.5 % calcium oxide granule coated with special dispersing agents, for use as a desiccant in rubber compounds which are cured on micro-wave systems, LCM or hot air.
Moisture which is present in all rubber chemicals, especially fillers, will be absorbed and the calcium oxide will change to calcium hydroxide after reaction with the moisture.

This reaction will happen while storing the uncured rubber compounds.
Kezadol GR is a soft 81.5% calcium oxide granule coated with special dispersing agents, for use as a desiccant in rubber compounds which are cured on micro-wave systems, LCM or hot air.

Moisture which is present in all rubber chemicals, especially fillers, will be absorbed.
The calcium oxide will change to calcium hydroxide.
This reaction will happen while storing the uncured rubber compounds.

It is also possible to use Kezadol GR as acid absorber e g. in systems containing chlorine.
Kezadol GR has a delayed action but a fast reaction.
If calcium oxide powder preparations are used they react during the mixing process, and so a higher dosage is required, which has a negative effect on the physical properties of the vulcanizate.

Kezadol GR is inactive during mixing but then reacts faster than other calcium oxide preparations, permitting shorter standing time between mixing and extrusion.
In comparison to CaO preparations in powder form, which react already during mixing process,.

Kezadol GR is a specialized additive used in the rubber industry as a moisture scavenger and acid absorber.
Kezadol GR's main role is to remove moisture from uncured rubber compounds, which helps prevent defects like blisters, porosity, or uneven curing.

Kezadol GR is particularly useful in modern curing processes, such as microwave, LCM (liquid curing medium), and hot air curing, where moisture control is critical.
Kezadol GR is composed mainly of calcium oxide (CaO), which makes up about 81.5% of the granules.

The granules are coated with dispersing agents to make them soft and easy to mix into rubber compounds.
This coating also moderates the reactivity of calcium oxide during the initial stages of mixing, ensuring the additive activates primarily when needed.

Physically, Kezadol GR appears as light grey soft granules, approximately 6–8 mm in size.
The granules have a density of roughly 2.36 g/cm³ and should be stored in cool, dry, sealed containers to maintain their effectiveness.

Exposure to moisture during storage can partially convert CaO to Ca(OH)₂, reducing its activity.
The shelf life of Kezadol GR is typically around one year if stored properly.

 
USES and APPLICATIONS of KEZADOL GR:
Primary Use: Kezadol GR is used as a desiccant in rubber compounding, especially in uncured rubber mixes containing moisture.
Curing Systems: Kezadol GR is used in pressureless continuous curing systems (microwave, LCM, hot air) where moisture control is critical.
Cable Industry: Kezadol GR is used in low-pressure curing for cables to prevent porosity in rubber insulation.

Rubber Types: Kezadol GR is compatible with a wide range of rubbers: NR, SBR, BR, IIR, EPDM, ACM, FKM, etc. (per Kettlitz).
Nitrosamine Inhibition: By acting as a base / absorber, Kezadol GR helps reduce nitrosamine formation during vulcanization.

Kezadol GR should be used in order to prevent blisters and porosity in the following rubber processes.-
Kezadol GR pressureless continuous curing systems like micro-wave, LCM, fluid beds or hot air
Kezadol GR is used Low pressure curing in the cable industry

Kezadol GR is used in compounds cured in heat transfer fluids
In addition to absorbing moisture, Kezadol GR can neutralize hydrochloric acid (HCl), helping protect metal parts in the curing equipment from corrosion and reducing the formation of nitrosamines, which are harmful substances that can appear during rubber vulcanization.

The coated granules help reduce dust compared to fine CaO powders, making it easier and safer to handle.
Overall, Kezadol GR is a multi-functional additive for rubber manufacturing.

Kezadol GR removes moisture, neutralizes acids, helps inhibit nitrosamine formation, and disperses easily in the compound.
Its controlled reactivity and broad compatibility make Kezadol GR a valuable ingredient for improving rubber quality, reducing defects, and protecting both the equipment and the finished product.

Kezadol GR is compatible with a wide variety of rubbers, including natural rubber (NR), SBR, BR, butyl rubber (IIR), EPDM, ACM, FKM, and HNBR.
The soft granules disperse well, even in soft rubber compounds, ensuring uniform moisture removal throughout the mixture.

Recommended dosages of Kezadol GR vary, but in many cases, 5–10% of the filler weight is used.
The dosage may be adjusted based on the amount of moisture present in the compound.
From a safety perspective, Kezadol GR is alkaline due to the calcium oxide content.

-Broad Polymer Compatibility uses of Kezadol GR:
Kezadol GR is compatible with a very wide range of rubbers: natural rubber (NR), SBR, BR, IIR (butyl), EPDM, ACM, FKM, HNBR, and even silicone rubbers.
This broad compatibility gives formulators flexibility: they can use Kezadol GR in different rubber types without switching to different desiccants.

-Dual Functionality: Moisture & Acid Scavenging uses of Kezadol GR:
Beyond just absorbing moisture, Kezadol GR serves as an acid absorber: it neutralizes HCl (hydrochloric acid) that may form in rubber compounds, forming calcium chloride.
This acid‑absorption function of Kezadol GR helps in reducing metal corrosion inside curing equipment or molds, particularly when chloride-containing systems are used.

-Nitrosamine Inhibition uses of Kezadol GR:
One notable benefit is Kezadol GR's potential to reduce nitrosamine formation in rubber compounds.
Nitrosamines are often a concern in rubber formulations (health / regulatory), and Kezadol GR helps mitigate that risk.

-Delayed Reactivity / Controlled Activation uses of Kezadol GR:
Kezadol GR is phlegmatized (treated) so that its calcium oxide core doesn’t react too quickly during mixing.
Most of the reaction (CaO → Ca(OH)₂) happens after the compound is mixed, during storage of the uncured rubber.

This “delayed action” is strategically useful: Kezadol GR gives time for moisture to be removed (or for the compound to be processed) before full reaction, reducing process risk.

-Improved Dispersion uses of Kezadol GR:
The granules are “soft” and coated with dispersing agents, which helps them disperse well even in soft rubbers or on open mills.
Better dispersion means more uniform moisture-scavenging throughout the rubber mix, reducing local defects (e.g., porosity or uneven curing).

BENEFITS & CHARACTERISTICS of KEZADOL GR:
*Efficient Moisture Control: 
Kezadol GR is effectively scavenges water in uncured rubber compounds, minimizing defects like blisters.

*Acid Neutralization: 
Kezadol GR helps mitigate acidic corrosion by reacting with HCl to form calcium chloride.

*Delayed Reactivity: 
During mixing, reactivity is limited (helps avoid premature reaction), but after mixing Kezadol GR becomes active, giving flexibility in processing.

*Good Dispersion: 
The soft, coated granules are easy to disperse, even in soft rubbers or on open mills, which improves processability.

*Nitrosamine Reduction: 
Kezadol GR reduces the risk of nitrosamine formation — an important safety / health consideration.

COMPOSITION of KEZADOL GR:
The main active component of Kezadol GR is calcium oxide (CaO) — approximately 81.5% CaO in the granules, per Kettlitz / Chemiteca.
The CaO granules are coated with special dispersing agents, to make them “soft granules” that disperse well in rubber compounds.
According to Knowde / Kettlitz, the granules are “phlegmatized” — meaning treated to moderate their reactivity / aggressiveness.

FUNCTIONAL CHARACTERISTICS of KEZADOL GR:
*Soft granules for easy dispersion in rubber compounds
*Delayed reactivity allows safe handling and mixing before full activation
*Dual function: moisture absorption + acid neutralization
*Compatible with a wide range of rubbers: NR, SBR, BR, IIR, EPDM, ACM, FKM, HNBR

OPTIMIZED DOSAGE STRATEGY of KEZADOL GR:
The suggested dosing of Kezadol GR: around 5–10% of filler weight (not just of total compound) in many cases, assuming some moisture is present.
For each “part” of water in the uncured compound (by weight), roughly 4 parts of Kezadol GR (by weight) are needed to absorb it, based on its CaO content.
They recommend adding Kezadol GR in the second mixing stage, because in the first stage (at higher temperature) a lot of moisture may escape, and you don’t want all CaO reacting too early.

STORAGE AND STABILITY CONSIDERATIONS of KEZADOL GR:
Storage recommendation: keep Kezadol GR in cool, dry conditions in sealed containers.
About 1 year under these conditions.
Because the granules are “active” CaO that reacts with water, humidity control during storage is important.
If exposed to moisture, they will gradually convert to Ca(OH)₂, reducing effectiveness.

STRATEGIC VALUE FOR RUBBER MANUFACTURERS of KEZADOL GR:
In continuous / pressureless curing systems (like microwave, LCM, hot air), moisture control is critical.
Kezadol GR offers a tailored solution for these modern curing processes.

Because Kezadol GR helps both moisture and acid, it reduces multiple risks (blow‑holes, corrosion, nitrosamines), making it a multi-functional additive rather than just a moisture absorbent.
Its good dispersion and controlled reactivity make Kezadol GR possible to use less aggressive or less purely reactive CaO, which can help maintain the mechanical and visual integrity of the final rubber vulcanizate.

DOSAGE of KEZADOL GR:
The dosage of Kezadol GR (80 % CaO) depends on the moisture contained in the compound.
The molecular weight of calcium oxide is 56, and 18 for water.
By these relations it can be seen that for every part of water by weight expected in the rubber compound approx. 4 parts of Kezadol GR are required in order to avoid blisters on profiles.

Kezadol GR is a standard practice to add quantities in excess of this amount, however, usually between 5 and 10 % calculated on the filler quantity.
We recommend to add Kezadol GR in the second mixing stage.

A big part of the humidity can escape in the first step at higher mixing temperatures without being absorbed by CaO.
Kezadol GR can be added to the compound together with the special packing, if mixing temperatures of more than 85 °C are achieved (melting range of the PE foil 60–85 °C).

PHYSICAL and CHEMICAL PROPERTIES of KEZADOL GR:
Physical & Chemical Properties
Appearance: Light grey, soft granules, about 6–8 mm in diameter. 
Physical form: Granular solid. 
Density: Approx. 2.36 g/cm³ at 20 °C (for the granules) per supplier data. 
Storage Stability: Recommended storage is in cool, dry conditions and sealed packaging; shelf life ~1 year. 
Chemical Reactivity: Calcium oxide reacts with moisture (water) in the rubber compound to form calcium hydroxide, which is how it “scavenges” moisture. 

Targeted Reaction with Acid: Kezadol GR can neutralize HCl, forming CaCl₂, which helps protect metal parts from acid corrosion.
Appearance: Light grey, soft granules
Granule size: Approximately 6–8 mm
Density: ~2.36 g/cm³
Physical form: Solid, granular
Solubility: Reacts with water to form calcium hydroxide (Ca(OH)₂); essentially insoluble in most organic solvents

Storage stability: Stable when stored in cool, dry, sealed containers; shelf life ~1 year
Chemical Properties
Main component: Calcium oxide (CaO) (~81.5% by weight)
Other components: Coating/dispersing agents to improve dispersion and reduce immediate reactivity
Reactivity:
Reacts with moisture to form calcium hydroxide, scavenging water in rubber compounds
Neutralizes acids such as HCl to form calcium chloride
Helps inhibit nitrosamine formation during vulcanization

pH: Strongly alkaline in water suspension (due to CaO content)
Molecular Weight: 56.07740
Exact Mass: 55.95750
EC Number: 215-138-9
ICSC Number: 0409
UN Number: 1910
DSSTox ID: DTXSID5029631

Color/Form: Grey-white, cubic crystals 
Colorless, cubic, white crystals 
Crystals, white or grayish white lumps, or granular powder 
Greyish-yellow, hydroscopic lumps
HScode: 2825909000
PSA: 17.07000
XLogP3: -0.11880

Appearance: Calcium oxide appears as an odorless, white or gray-white solid in the form of hard lumps. 
Used in insecticides and fertilizers.
Density: 3.3-3.4 g/cm3
Melting Point: 2572 °C
Boiling Point: 2850 °C
Flash Point: 2850ºC
Refractive Index: 1.83
Water Solubility: Reacts

Storage Conditions: Store at RT.
Vapor Pressure: 0 mmHg (approx)
Flammability characteristics: Noncombustible Solid, but will support combustion by liberation of oxygen.
Explosive limit: No explosive propertiy
Odor: Odorless
PH: SATURATED SOLN IN WATER IS ABOUT 12.8
Experimental Properties: Crumbles on exposure to moist air 
Commercial grade is usually yellowish or brownish tint, due to iron 

Readily absorbs CO2 and H2O from air, becoming air-slaked. 
A powerful caustic to living tissue. 
The powdered oxide may react explosively with water.
Air and Water Reactions: Crumbles on exposure to moist air. 
Reacts with water to form corrosive calcium hydroxide, with evolution of much heat. 
Temperatures as high as 800° C have been reached with addition of water (moisture in air or soil). 
The heat of this reaction has caused ignition of neighboring quantities of sulfur, gunpowder, wood, and straw 

Reactive Group: Bases, Strong
Reactivity Alerts: Water-Reactive
Reactivity Profile: A base and an oxidizing agent. 
Neutralizes acids with generation of heat. 
Nonflammable, but will support combustion by liberation of oxygen, especially in the presence of organic materials. 
Reacts very violently with liquid hydrofluoric acid. 
Reacts extremely violently with phosphorus pentaoxide when reaction is initiated by local heating.
Autoignition Temperature: Not flammable

FIRST AID MEASURES of KEZADOL GR:
-Description of first-aid measures
*General advice:
Show this material safety data sheet to the doctor in attendance.
*If inhaled:
After inhalation: 
Fresh air.
*In case of skin contact: 
Take off immediately all contaminated clothing. 
Rinse skin with
water/ shower.
*In case of eye contact:
After eye contact: 
Rinse out with plenty of water. 
Call in ophthalmologist. 
Remove contact lenses.
*If swallowed:
After swallowing: 
Immediately make victim drink water (two glasses at most). 
Consult a physician.
-Indication of any immediate medical attention and special treatment needed.
No data available

ACCIDENTAL RELEASE MEASURES of KEZADOL GR:
-Environmental precautions:
Do not let product enter drains.
-Methods and materials for containment and cleaning up:
Cover drains. 
Collect, bind, and pump off spills. 
Observe possible material restrictions. 
Take up dry. 
Dispose of properly. 
Clean up affected area.

FIRE FIGHTING MEASURES of KEZADOL GR:
-Extinguishing media:
*Suitable extinguishing media:
Carbon dioxide (CO2) 
Foam 
Dry powder
*Unsuitable extinguishing media:
For this substance/mixture no limitations of extinguishing agents are given.
-Further information:
Prevent fire extinguishing water from contaminating surface water or the ground water system.

EXPOSURE CONTROLS/PERSONAL PROTECTION of KEZADOL GR:
-Control parameters:
--Ingredients with workplace control parameters:
-Exposure controls:
--Personal protective equipment:
*Eye/face protection:
Use equipment for eye protection. 
Safety glasses
*Body Protection:
protective clothing
*Respiratory protection:
Recommended Filter type: Filter A 
-Control of environmental exposure:
Do not let product enter drains.

HANDLING and STORAGE of KEZADOL GR:
-Conditions for safe storage, including any incompatibilities:
*Storage conditions:
Tightly closed. 
Dry.

STABILITY and REACTIVITY of KEZADOL GR:
-Chemical stability:
The product is chemically stable under standard ambient conditions (room temperature).
-Possibility of hazardous reactions:
No data available