Capstone™ ST-300
Repellent

Penetrating Sealer for Porous Surfaces
Technical Information
Description

Typical Properties

Capstone ST-300 is an anionic aqueous fluorochemical
dispersion with no intentionally-added VOC that provides
a durable, non-film forming, transparent protective barrier
against oil and water on porous mineral surfaces. Capstone™ ST-300 is a repellent used in water-based penetrating sealers for stone, unglazed tile, grout, terra cotta,
concrete, and brick. Capstone™ ST-300 provides oil andwater repellency, stain resistance, and easy stain cleanup.

Appearance

Colorless to yellow liquid

Stability

Stable at normal temperatures.
Perishable if frozen. Viscosity may
increase with time or cold storage

pH

7.5–9.0

Active Solids, %14Density, g/mL

1.1

Flash Point (Closed Cup), °C (°F)

Does not flash™

Applications and Formulating Information

Shelf Life

2 years

Capstone ST-300 is used in diluted solutions containing
1.5–2.5% active ingredient (10–18% commercialproduct) working strength with deionized or soft water(<50 ppm hardness). Typical coverage rate is from
3–25 m²/L of diluted solution, depending on the porosityof the mineral substrate. Thoroughly wet the surface
being treated with the diluted product, and remove excess
liquid after 15–30 min. The optimum dilution rate should
be determined for each application. If blended, maintainpH >7.

Spray

Do not spray™

This product is anionic and is usually compatible withother materials in a blended system (except cationicadditives). It is recommended that blended system bechecked for stability. The product may be applied using
a saturated brush, roller, paint pad, mop in one or twolayers (to ensure complete coverage). DO NOT SPRAY.
A biocide should be added to formulations made using
Capstone™ ST-300 to protect the formulation against
microbial growth.

Performance
Capstone™ ST-300 (diluted to 13% of commercial
product in deionized water) was compared to acompetitive aqueous-based silicone sealer. Each productwas applied to limestone and Saltillo (Mexican clay tileor terra cotta) and allowed to dry for three days. Cornoil, Italian dressing, ketchup, mustard, grape juice, andcoffee were then placed on the treated substrates. After
24 hr, the tiles were washed with a 1% soap solutionand allowed to dry. The ratings were totaled for each tile
sample. The results below show that Capstone™ ST-300
outperformed the competitive aqueous-based silicone
sealer. Similar results have been achieved on other porous
mineral substrates.

Repellent

Capstone™ ST-300

Personal Safety, First Aid, Storage and Handling

Scoring System for Each Stain After Dry
No Visible Stain

0

Very Slight Stain

1

Light Stain

2

Moderate Stain

3

Heavy Stain/Complete Penetration of Stain into Substrate

4

See Safety Data Sheet (SDS) for use and handlingrecommendations. Review this information with all
personnel handling Capstone™ ST-300. Mix well before
using. Protect from freezing. Do not spray.

Capstone™ Repellents and Surfactants• Deliver maximum performance• Regulatory and stewardship information is available
upon request

Scoring System for Water/Oil Repellency• Are listed on TSCA inventory
5—Excellent

4—Very Good

3—Good2—Fair

1—Poor0—Penetration

5 Contact angle 100–120°

4 Contact angle 75–90°

3 Contact angle 45–75°

2 Contact angle 25–45°

1 Contact angle 10–25°

0 Contact angle <10°

Package Sizes
Tote–2,200 lb (998.8 kg), Drum–440 lb (199.76 kg),
Pail–40 lb (18.16 kg), Bottle–8 lb (3.632 kg)
For questions regarding technical data, commercial
supply, and sampling:
Chemours Advanced Performance Materials

Performance Comparison

Technical Inquiries

24 hr Stain Scores of Six Stains
Treatment

Limestone

Saltillo

Capstone™ ST-300

26

Silicone (aqueous)

813

Untreated

1921

Cumulative scale from 0 (best) to 24 (worst).
Lower score = Higher performance

Oil Repellency

Water
Repellency

Stain
Resistance

Capstone™ ST-300

Excellent

Excellent

Excellent

Silicone (aqueous)

Poor

Excellent

Poor to Good

Untreated

NoneNoneVery Poor

Treatment

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Newark, DE 19713 USA+1.866.828.7009

For more information, visit www.chemours.com/capstone
CAUTION: Do not use or resell Chemours™ materials in medical applications involving implantation in the human body or contact with internal body fluids or tissues unless agreed to by Seller in a writtenagreement covering such use. For further information, please contact your Chemours representative. For medical emergencies, spills, or other critical situations, call (866) 595-1473 within theUnited States. For those outside of the United States, call (302) 773-2000.
The information set forth herein is furnished free of charge and based on technical data that Chemours believes to be reliable. It is intended for use by persons having technical skill, at their own discretion
and risk. The handling precaution information contained herein is given with the understanding that those using it will satisfy themselves that their particular conditions of use present no health or safetyhazards. Because conditions of product use are outside our control, Chemours makes no warranties, express or implied, and assumes no liability in connection with any use of this information. As with anymaterial, evaluation of any compound under end-use conditions prior to specification is essential. Nothing herein is to be taken as a license to operate under or a recommendation to infringe any patents.
NO PART OF THIS MATERIAL MAY BE REPRODUCED, STORED IN A RETRIEVAL SYSTEM OR TRANSMITTED IN ANY FORM OR BY ANY MEANS ELECTRONIC, MECHANICAL, PHOTOCOPYING, RECORDING OR OTHERWISEWITHOUT THE PRIOR WRITTEN PERMISSION OF CHEMOURS.

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Replaces: K-20097-2
C-11342 (6/21)