Supply form

   Baspar resin is supplied in 200 liter Steel drums with a content of 180 Kg.                                    

Storage                     Baspar may be stored at room temperature. It is storable for 6 months.                                                 Crystallization may sometimes occur but can be reversed by mild heating                                              without any adverse effects on product quality. 

                                         Some increase of viscosity could be corrected by adding of solvent.     

The following figure shows the change in viscosity of Baspar polymer solution (weight percent) over a four-month period. The viscosity increase is not detrimental to polymer performance. Usually the solution's viscosity can be adjusted with additional solvent and the solution used without loss of performance.

Processing

                             Binder resin Baspar may also be combined with suitable PTFE or        fluorothermoplastic powders to produce aqueous coating systems.                           

                            The ratio between the binder resin and fluoropolymer depends on the required property spectrum and must be determined by suitable trials.                           

                           The stoving conditions depend on the additives used and the required properties                            and range between 200 and 420 °C.

Use In Paints

Fillers , Pigment and Additives

Fillers are chosen in order to increase or at least not to reduce the thermal stability of the coating and in addition to impact special properties to the paint. Zinc powder may be used for primer coats in anti corrosion systems. Titanium dioxide such as Kronos RN59, talc, barium sulfate, aluminum paste may be employed for finishing coats.

Pigments must have good heat stability.

Solvents and diluents are used to lower the viscosity. A number of products are suitable and behave either as solvents or as diluents.

The two following solvent systems provide good results with respect to paint processability and high gloss:

Dimethylformamide                         1 part per weight

2-Nitropropane                                  1 part per weight

N-Methylpyrrolidone                        1 part per weight

Dimethylformamide                          1 part per weight

Ethylglycolacetate                             2 parts per weight

Of course apart from these two mixtures, other solvent systems can be used. However products of low volatility such as NMP for example should not be used in too large amounts. It is not advisable to introduce a diluent such as xylene without premixing with solvent such as DMF to avoid local precipitation of the polymer which disappears under agitation. This phenomenon is due to temporary local excess of diluents. Chlorinated solvents must be avoided since they will cause the solution to gel. Anhydrous solvents or diluents should be used to obtain optimum results. The fact that NMP and DMF are hygroscopic solvents should be taken into account.

Additives

In case of application on vertical surfaces the addition of thixotropic agent will avoid dripping and sagging.Aerosil 200 silica used at a level of 0.3 to 0.5 % on RHEDEFTAL 200 ES is effective to impart good thixotropic properties. Beyond these concentrations it tends to give paints with reduced gloss. Silica must be ground with the other components. It is better, before introducing silica into the mix, to prepare a mixture of about 5 % silica in a nonpolar solvent such as Xylene in a turbine mixer which makes its dispersion into the paint easier.

Bentone 27 gives about the same results as Aerosil 200.

In order to prevent the formation of defects such as poor leveling and discoloration we advise using Nuosperse 657(1) at a level of 0.2 g per 100g of Baspar. In addition for very difficult coating conditions we advise adding BYK 310(2) at a level of 0.025 to 0.05g per 100g of Baspar.

These additives must be preferably incorporated into the paint before grinding. They tend to settle on storage but simple stirring restores their dispersion in the paint medium.

(1)    Rhone-Poulenc Chimie,88 Boulevard Des Belges,F-69006 Lyo

(2)    BYK-Chemie GmbH,Abelstrasse 14, D-230 Wesel;FDA 175.300 approved

Preparation of the paints

The usual methods (three rolls or ball mill) can be employed. In the latter case homogenization is achieved in about 72 hours. Generally all the paint components should be ground at the same time.

Depending on the gloss, heat resistance and physical properties various pigment/binder rations can be used.

Preparation of substrates

The substrates must be very clean, carefully degreased (washing with trichloroethylene and rising with acetone) and dried.Non-metallic substrate (glass, asbestos…)are cleaned by exposure at 300°C.

Coating process

Small pieces may be coated either by dipping, brushing or with a spray-gun (with either hot or cold paint).Large surfaces may be also coated with an airless gun using hot or cold paint. It is also possible to use an electrostatic gun.

In the case of a formula well adjusted from the point of view of solvent and thixotropy, the coating can be made on a cold substrate without dripping. A 15 µ dry film can then be applied without blistering. In case of a substrate of very intricate shape it may be advisable to preheat the piece at about 80-90°C.

Curing must be performed at 220°C minimum but it is better carried out at 250°C in order to obtain good end properties.

·         3 min. at 250°C for very flexible paints.

·         5 min at 250°C usual curing time.

·         15 min at 250°C for very good chemical resistance.

Curing at 300°C for 2 to 5 min. also gives good results. The caloric capacity of the painted pieces must be taken into account. The above curing times are given for small pieces. Larger pieces need longer times or higher temperatures. When it is necessary to apply several coats of paint in order to obtain good adhesion it is better not to dry completely the preceding coat. 1 to 2 min. curing at 250°C gives excellent results.

Curing of paints with Baspar may also be made by IR irradiation. In this case, for a 6 W/cm2 apparatus, we recommend 5 min. at about 5 cm from the coated substrate.

Formulations

The following formulations illustrate the main use of Baspar. They must be considered as base formulations and should be adjusted to each particular case.

Glossy paint of different colors

BASPAR  30                                                                   100

Pigments inorganic                                                     15

DMF                                                                               27.5

2NP                                                                                27.5

Dispersion of 5% Aerosil 200 in xylene                    8

Nuosperse 657                                                             0.2

BYK310                                                                         0.025

Glossy black paint                                                            Industrial red iron oxide coat

BASPAR  30                                     100                             BASPAR 30                                          100

Special black 4 Degussa                2.5                              Red iron oxide 130F                           45

DMF                                                  27                               NMP/xylene                                        120

2NP                                                   27                               Nuosperse 657                                    0.3

Nuosperse 657                              0.2                               BYK310                                                  0.025

BYK310                                           0.025                           This paint gives a mat finish.

Aluminium paint(type car exhaust pipe)

BASPAR  30                        100                      This paint has a thermal resistance of 1000 h at 300°C

Aluminium paste               15                       Chalking begins after about 200 hours.

NMP/xylene 60/40           76

BYK310                               0.025

All these paints have a good thermal stability. Light shades are however more sensitive because the resin may become discolored without significantly altering the mechanical and adhesion properties.

We can say that for 1000 hours and more:

Light shades are stable at 200°C

Dark shades are stable at 220°C

Black and very dark shades are stable at 250°C

Non- hammer finished aluminium paints are stable at 300°C

Protective paints

Besides their thermal stability these paints show good resistance to salt spray. This requires the application of an anti –corrosion primer followed by the application of a finishing coat.

Where temperatures do not exceed 300°C we recommend the use on steel or aluminium substrates of Zinc powder or strontium chromate in the formulation of the primer.

For the under coat we propose the following formulation:

BASPAR  30                                        100

Zinc powder                                       130

NMP/xylene 60/40                           100

Aerosil 200                                         2

Nuosperse 657                                 0.1

BYK 310                                             0.025

The formulation for decorative coats quoted previously may use as finishing coats. For good stability at 300°C we recommend formulation including red iron oxide 130 F, black special 4 or aluminium powder.

These paints can stand a thermal aging of 100 h at 300°C followed by an exposure of 100 hours to salt spray.

Use as an outstanding wire enamel

Processing

The coils are impregnated by dipping. The retention of varnish on steel after draining (ASTM D-115) is about 3 %.

Curing

For small coils, it is recommended to load the components into the oven at room temperature and to bring it up to 250°C in 5 to 7 hours.

Post-  cure

A final cure of 20 min. at 250°C gives a bonding strength measured at room temperature on an aluminium solenoid (NF C 26-937) of 200N.

To obtain optimum bonding strength at high temperature, a post – cure for 1 hour at 300°C or for about 20 hours at 250°C is recommended.

Properties after curing

For 2 hours at 250°C

Property                                                                   Standard                                                       Value

Dielectric  strength  on 0.02 mm                             NF C26-925                                          150KV/mm

Volume resistivity                                                      VDE 0360

Dry                                                                                                                                                  1.200⁶ cm

After 24 hours water immersion                                                                                               4.200³ cm

Thermal aging on coated

Glass cloth                                                                   ASTM 1-366-57

Dielectric strength

.  after 1150 h at 250°C                                                                                                  43 KV/mm

.  after 2150 h at 250°C                                                                                                  40 KV/mm

     Weight loss

.  after 1150 h at 250°C                                                                                                                9%

.  after 2150 h at 250°C                                                                                                             11%

Heat resistance                                                      VDE 0360

Number of cycles of                                                                                                                 >70

24 hours at 250°C

Bonding strength

On solenoids (NF C 26-937)      

After Curing for 2 hours at 250°C and post – curing for 20 hours at 250°C                        

Measured at 25°C                                                                                                                200N    

Measured at 200°C                                                                                                      100 – 150 N

After thermal aging (measured at 25°C).                                                                                    

200°C                                             2000 hours                                                                150 N

                                                       27000 hours                                                                40 N          250°C                                            2000 hours                                                                130 N                                                                 6500 hours                                                                 40 N      

275°C                                             3000 hours                                                                  40 N       

300°C                                             2000 hours                                                                  40 N

Life – time vs. temperature.

Bonding strength measured at 25°C (standards NF C 26937) equal to 40 N.

Use as varnish for coating

Processing

·         Objects may be coated either by dipping or with a spray gun. Pneumatic guns may be used either at room or at elevated temperatures (70 - 80°C).

·         Drainage retention on steel sheet (ASTM D-115) is in the region of 3% with a non-diluted varnish. When coating a diluted varnish (15% dry extract), the thickness is about 15 to 20 microns.

·         Small parts are cured for 1 – 3 minutes at 300°C.But larger pieces are best treated at a temperature of between 200 – 250°C for an appropriate time.

Diluent                 Max ratio (per weight) : Diluent/N-Methylpyrrolidone

                                                              Toluene              100/100

                                                               Xylene                  67/100

                                                            Ethylacetate           86/100

                                                            Butylacetate           57/100

                                                            Butylglycol               57/100

                                                              Dioxane                145/100

The viscosity of such diluted varnishes remains practically unchanged after months at room temperature and solutions still remain clear. Chlorinated thinners must be avoided, as they cause the rapid gelation of the varnish.Methylethylketone is also to be avoided, since it causes the solution to gel after a few months.

Typical Formulations

The use of diluted Baspar does not allow avoidance of film defects. It is therefore recommended to use BYK 310, which can be incorporated after the addition of thinners into Baspar. The following starting formula should produce good results:

              BASPAR 30                                                        100 weight by parts

              N – Methylpyrrolidone                                     60 weight by parts

               Xylene                                                                 30 weight by parts

              Ethyl glycol                                                          10 weight by parts

               Byk 310                                                            0.05 weight by parts   

Properties after a curing at 250°C for 2 hours (or 3 min. at 300°C)

                Properties                                       Standard                                                      value                                                                                                                                              

     Dielectric rigidity on 0.2 mm                      --                                                      150KV/mm

Tensile strength                                               VDE 0360

.  dry                                                                                                                                 1.10¹⁶ cm

.  after 24 h in water                                                                                                      4.10¹³ cm

Thermal impact resistance (24 h / 250°C      VDE 0360                                 above 70 cycles

Persoz hardness          at room temperature                                                             340 sec.

                                       At 200°C                                                                                     200 sec.   

Adherence                                                         NF T30-038

.  on aluminium                                                                                                                           good

.  on steel                                                                                                                                      good

.  on sand blasted copper                                                                                                          good

.  on steel + 17 % chromium                                                                                                 medium                                                                                         

Resistance to chemical agents                      NF X41-002

.  to salt spray                                                                                                                              good

.  to usual solvents                                                                                                                      good

.  to diluted acids                                                                                                                         good

.  to detergents                                                                                                                            good

.  to grease and facts                                                                                                                  good

.  to concentrated alkalis                                                                                                           bad     

Resistance to thermal aging (200 - 250°)                 --                                                            good        

Impact resistance                                           NF T 30-019                                                  good at max.

T – Bend Test (E.C.C.A.)                                 NF T 30-039                                                       O.T.

Note:  This information is intended to provide general notes on our products and their uses. It should not therefore be construed as guaranteeing specific properties of the products described or their suitability for a particular application. Any existing industrial property rights must be observed. The quality of our products is guaranteed under our general conditions of sale. Please pay attention to check or study carefully before using these materials if they are suitable for your purpose application and process condition, etc. All the data showed in this list is only for your reference, not guaranteed.