Clearclad HSR Data Sheet .... ()

1. PRODUCT DESCRIPTION

CLEARCLAD HSR is a cathodic electropaint system which combines all the advantages of its application technology with outstanding chemical resistance, high build capability to confer wear resistance, and excellent weathering properties due to its high degree of UV resistance. These together with its excellent decorative properties make CLEARCLAD HSR an advanced coating system for a wide range of substrates and applications.

2. SUPPLY FORM

The base resin concentrate of CLEARCLAD HSR is a tan colored, free flowing liquid of moderate viscosity. Pigmented and matte variants will vary in appearance and viscosity accordingly.

Packaging is 20 kg American Pails. Other packing types and sizes may be available on request.

3. SUPPLY SPECIFICATION

This will vary according to product type. The base resin concentrate is supplied in ready-to-dilute form, solids content 45 - 50% by weight (determined gravimetrically at 120oC for 1 hour).

4. METHOD OF DILUTION

CLEARCLAD HSR concentrates should always be pre-mixed with either high purity demineralised water, or bath material at coating solids, when making a new bath or replenishing an existing bath respectively.

Pre-mixing must take place in a suitable clean vessel equipped with a motorized stirrer. Diluting material is added gradually to the concentrate, under stir, until a solids content of less than 18% is achieved. At this stage, at least 10 minutes stirring is applied to achieve complete emulsification. Subsequently, this pre-mix may then be further diluted to the required solids or added to the bath as appropriate.

CLEARCLAD HSR concentrates must never be added directly into demineralised water or into the bath without this pre-mixing procedure.

5. CONDITIONING OF NEW BATHS

A period of at least 24 hours, and preferably 48 hours, should elapse between initial bath make up and commencement of production. During this time, the bath should be kept circulating through adequate particle filtration at its normal operating temperature, and at least one bath volume of ultrafiltrate permeate should be eliminated. Solvent loss due to permeate elimination is not significant, but the MEQ (corrected) should be maintained at a minimum value of 30 by appropriate additions of CLEARCLAD Emulsion Stabilizer.

6. BATH OPERATING PARAMETERS

 
7. ASSESMENT OF CURE

Due to CLEARCLAD HSR having extremely high resistance to chemicals and solvents, a quick unequivocal test for cure/polymerization such as the acetone rub test is difficult. Using cotton wool as the absorbent for acetone, it is normal for fully cured HSR to require 1000 double rubs. A lower number may be achieved if absorbent paper is used, but the mechanism of the test is laborious and therefore subject to operator variability.

In this case, in order that the adequacy of cure may be assessed for production quality control, we suggest that a correlation is established between resistance to acetone rubs and immersion of the test part in either acetone or ethanol. The immersion test will be assessed in terms of the length of time of immersion consistent with the coating passing a pencil hardness test.

The parameters of this test will be degree of polymerization and coating thickness. The action of the acetone/ethanol will be to permeate the coating and swell it. This has the effect of softening the coating and its apparent pencil hardness will reduce.

Example: A coated part is immersed in ethanol for 30 minutes and tested with 2B pencil. Resistance of the coating to removal to substrate would be deemed a pass.

It is not possible here to specify the performance of such a test. The user should establish the values of the parameters according to the particular degree of polymerization required by the application, as this factor can vary.

Alternatively, if the thermogram of the stoved part is monitored using an oven temperature tracking device, and this indicates compliance with the cure schedule, then this may be accepted by the user as a predictor that adequate cure has been achieved.
 

8. COVERING POWER

One kilo of the base resin concentrate of CLEARCLAD HSR will apply a coating of 1 micron over approx. 450 sq.metres assuming 100% efficiency.

Near to 100% efficiency can be achieved using closed-loop ultrafiltration reclaim. Without a reclaim system, efficiency and consequently covering power will reduce.

"Tinted" systems, using relatively low concentrations of colorants, will have covering power very similar to the base resin concentrate. Other types of pigmented systems, incorporating significant concentrations of dense colorants or matting agents will have lower covering power. This will depend entirely on the particular product and such information will form part of the appropriate data sheet.
 

9. RESISTANCE OF CLEARCLAD HSR COATING TO ULTRAVIOLET LIGHT

In addition to CLEARCLAD HSR's outstanding resistance to a great variety of chemicals, it has been formulated to have high resistance to UV light in order to render it suitable for exterior applications where resistance to the effects of weather is essential. As a transparent coating, its UV resistance is comparable to the best available exterior-quality acrylics or polyesters. However, its principal advantage is in being able to provide the well established "tinted" simulation of colored metals onto reflective "white" metal substrates, but with at least ten times the color change/fade resistance achieved with previous similar systems. (assessment using DE measurements according to the CIELAB system after exposure to minimum 500 hours QUV UVB).

LVH have developed a colorant system which will achieve yellow metal effects from "brass" through "gold" to "bronze", the actual color being determined by a combination of the mixed colorants and the color of the base metal.

Other colored "tints" in addition to hard colors including white and black in a range of gloss values may be formulated on request.
 

10. RESISTANCE OF CLEARCLAD HSR TO ARTIFICIAL PERSPIRATION

As a principal target market for CLEARCLAD HSR is door and window hardware, the resistance to handling in terms of sensitivity to human perspiration is of great importance. Accordingly, one of the prime criteria in the development of CLEARCLAD HSR has been the compliance with the perspiration test detailed in the ANSI/BHMA "American National Standard For Bored And Preassembled Locks And Latches". At full cure and 20 microns thickness, CLEARCLAD HSR will readily comply with this demanding test.

This also makes CLEARCLAD HSR suitable for other applications where, especially, contact with and resistance to human perspiration may be a requirement.
 

11. CORROSION PROTECTION AFFORDED BY CLEACLAD HSR COATING

The resistance to corrosion of any coated metal is always determined by the particular "system" - which means a combination of the base metal, its pretreatment, the type of coating applied, and the thickness and type of pigmentation of the coating.

CLEARCLAD HSR is effectively a one-coat paint system. Accordingly, its corrosion-protective properties will be principally influenced by its thickness and quality of adhesion to the base metal. In this way, HSR will provide a barrier (optimized by its thickness) to corrosive agents, and a resist against spread of corrosion (optimized by its adhesive strength). Further than this, the intrinsic corrosion resistance of the base metal should be optimized, for example by the chromating of brass and zinc. Proper preparation of the base metal will both increase the intrinsic corrosion resistance and enhance the adhesion of HSR, both factors combining to optimize the corrosion resistance of the whole system.
 

12. WEAR AND ABRASION RESISTANCE

CLEARCLAD HSR has good intrinsic abrasion resistance (as determined by ASTM D968 Falling Sand test - 18 litres/25 micron thickness). This in combination with it being a high-build product (30 micron thickness readily available) affords a high degree of wear and abrasion protection. As the absolute wear property of organic coatings is principally a function of thickness, applications demanding wear resistance should utilize the higher thickness available with HSR.

Comparison of CLEARCLAD HSR with some competitive products with respect to chemical and physical tests.

1. Using acetone soaked tissue paper. Rating is when the coating is removed to the substrate.
2. ANSI/BHMA test.
3. Gouge method. Load on pencil approx. 2000gm.
4. ASTM B117 neutral salt spray. Criterion is no more than 2mm creep of corrosion from a scribe cut to substrate.
5. ASTM D968 using Ottowa sand.
6. QUV using UVB 313 tubes. 2 hours UV at 60^oC/1 hour condensation at 0^oC. DE of 2.0 is a just perceptible change in color. "Complete fade" is equivalent to approx. DE 20.
7. Ultrafiltrate reclaim not used.