Exposure Conditions

The current status of the weathering tests is described in Table 6. The outdoor exposure test is being carried out at three different sites (north: Hokkaido, central: Chiba and south: Okinawa) in Japan. Testing conditions of outdoor and accelerated weathering exposures are also shown in Table 6, while the geo­graphic features of the different outdoor exposure locations are shown in Table 7. The conditions of the

TABLE 5—Sealants tested.

Sealants

Mark

Number of products

Silicone (two-pan)

SR-2

2

Silicone-modified poly ether (general purpose) (one – pan)

MS-1 (GP)

3

Silicone-modified polyether (high weatherability) (one-part)

ms-і (hw)

3

Silicone-modified polyether (general purpose) (two – part)

MS-2 (GP)

2

Silicone-modified polyether (stress relaxation type) (two-part)

MS-2 (SR)

2

Poly sulfide (one-part)

PS-1

1

Polysullide (two-part)

PS-2

2

Silicone-curable poly isobutylene (two-part)

IB-2

3

Polyurethane (one-part)

PU-T

2

Polyurethane (two-part)

PU-2

1

Acrylic urethane (two-part)

UA-2

1

Acrylic (water borne, one-part)

AC-1

2

TABLE 6—Experimental conditions and current status of exposure tests.

Outdoor exposure

Accelerated exposure

Xenon arc lamp (XWM)

Open flame carbon arc (SWM)

Fluorescent UV lamp (UV)

Term

Plan

20 years

10 000 h

5000 h

5000 h

Current

12 month

3500 h

3500 h

– (started)

Interval of

status

1 month

500 h

transformation

Conditions

[Location within Japan]

[Irradiation]

[Irradiation]

[Irradiation]

• North

• 550 W/m2

• 255 W7m2

• 25 W7m2

• Central

• 290-800 nm

• 300-700 nm

• 300-400 nm

• South

• b. p.:63°C

• b. p.:63°C

• b. p.:63°C (on)

• [Angle]

• r. h.:50%

• r. h.:50%

• 50°C (off)

•45°

• 102 min. irrad.+18 min. spray

• 102 min. irrad.+ 18 min. spray

• 4 h on +4 h off

North

Central

South

Latitude

43°46’N

35°43’N

24"44’N

Average maximum temperature (°С)

11.8

18.8

26.2

Average minimum temperature (°С)

2.2

10.6

21.0

Precipitation (mm/year)

1150

1481

2058

Amount of UV radiation* (()’•, MJ/m2 in year)

240

313

367

TABLK 7—Geographic features of outdoor test locations.

aWave length: 315-400 nm.

accelerated exposure were based on ISO 4892 (Plastics-Methods of exposure to laboratory light sources)

[5] . The switching interval of the extension/compression position in the accelerated weathering exposure was chosen as 500 h.

(a) Chemical type of sealants

FIG. 4—(a) Degree of degradation in outdoor weathering exposure (6 months), (b) Degree of degradation in outdoor weathering exposure (12 months).

[XWM]

Intermediate Results

Outdoor Exposure

The degree of degradation of the sealants after 6 and 12 months outdoor exposure is shown in Figs. 4(a) and 4(b) as the average over the three outdoor exposure sites and the different sealant products for each chemical type of sealant.