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The glass frame containing mineral oil is one of the root causes of the dissolution and swelling of the insulating glass butyl or silicone insulating glass sealant

Abstract: This article uses butyl glue, silicone glue, and/or glass glue to make a series of insulating glass, and the compatibility test and result in an analysis of butyl glue/silicone glue/glass glue. One of the reasons for the dissolution or swelling of the base/silicone insulating glass sealant during framing is the use of mineral oil-containing glass glue.

Keywords: insulating glass, glass glue, mineral oil, compatibility  

The butyl insulating glass sealant on the inner channel of the insulating glass and the silicone insulating glass sealant on the outer channel is directly sealed as a whole. The glass glue used in the framing of the insulating glass is in direct contact with the outer silicone insulating glass sealant of the insulating glass through point type, and it is in direct contact with the inner butyl insulating glass sealant of the insulating glass. However, whether it is in direct contact or indirect contact, the sealing performance of insulating glass requires that the various sealing and adhesive materials used should have good compatibility, and no dissolution, swelling, etc. should be caused.

At the end of 2019, a glass deep processing company in Saudi Arabia delivered the insulating glass made by the combination of internal and external butyl/silicone insulating glass sealant to the customer (specially insulating glass door and window company). The door and window company used glass glue to install the frame on the building. After 2-3 months of use, the inner butyl insulating glass sealant will dissolve to varying degrees-the butyl glue flows into the insulating glass spacer along with the aluminum spacer frame. In winter, condensation or condensation appears in the insulating glass. Frosting phenomenon, the hollow glass completely fails to seal. Through the detection and analysis of the hollow glass that has been problematic, the detection results obtained are shown in Table (1). The properties of the inner and outer insulating glass sealant and the original rubber of the insulating glass have changed, that is, the pores of the silicone insulating glass sealant are filled with oil and swelling, and the butyl insulating glass sealant is in the state of a homogeneous cement with moderate hardness. It becomes a paste that can stick to black hands, showing dissolution. Others such as color, odor at room temperature, flame burning characteristics, and volatile matter have also undergone fundamental changes. 

To understand the root causes of changes in properties of the inner and outer butyl/silicone insulating glass sealants in the framing process of insulating glass, Jinan LIJIANG Glass simulated a series of insulating glass and used butyl rubber/silicone. Compatibility test between glue/glass glue.

Table 1 The inspection results of problematic insulating glass

Test itemsInner butyl rubberOriginal butyl gumExternal silicone glueOriginal silicone glueGlass glue
Color and conditionSticky black ointmentModerately soft and hard homogeneous clayLight blackBright black/
Smell at room temperatureSmell of mineral oilTastelessSmell of mineral oilTastelessstrong mineral oil smell
ElasticityComes in the form of a dissolved ointment that cannot be pulledCan be pulled into stripsBetterGenerally/
Volatilize
180/3h
4.940.174.940.4721.04
Section//There is oil in the pores of the silicone rubberNo other substances in the pores of the silicone/
Flame burningBlack smoke
yellow flame
Can be directly ignited
Smell of mineral oil
Black smoke yellow flame
Can be directly ignited
Smell of mineral oil
White smoke with a small amount of black smoke
White dust
Poor flame retardancy
White smoke
White dust
Poor flame retardancy
White and black smoke
White dust
Can be directly ignited
Remark
1. The insulating glass adopts aluminum spacer with a width of 5mm; 3A molecular sieve, plastic gusset
2. The thickness of the insulating glass outer channel silicone glue is about 1.5mm-2.2mm, and the average thickness is about 2.0mm
3. Irregularly coated glass glue frame on the outer silicone glue and two pieces of glass

1. Preparation of test piece  

1.1 Preparation of hollow glass specimen

The size of the insulating glass is 5A: 350X300, the inner seal is coated with Huayna 130 type butyl insulating glass sealant, and the outer seal is coated with 2mm thick Huaya type II silicone insulating glass sealant, and the commercial contains mineral oil. The glass glue used for single-sided coating, peripheral coating, or spot coating is in direct contact with the outer insulating glass sealant. At the same time, a group of insulating glass is coated with only the inner butyl glue, and the outer silicone glue and glass glue are not coated. As a blank control test.

1.2 Preparation of butyl rubber/silicone rubber/glass glue compatibility test piece

In the compatibility test pieces of butyl rubber, silicone rubber, and glass glue containing mineral oil, the butyl rubber adopts a certain domestic brand of butyl rubber and a foreign brand of butyl rubber, but butyl rubber is used in the main test. Mainly use Jinan LIJIANG Glass butyl insulating glass sealant. The butyl rubber is made into a round piece with a diameter of 100mm and a thickness of 6mm. Coat the middle of the round piece with silicone insulating glass sealant (a domestic and foreign brand silicone insulating glass sealant, the main test is still used Jinan LIJIANG Glass silicone insulating glass sealant), the size is 65mm*65mm, and the thickness of the glue is 0-7 (mm) according to the test design requirements. After the silicone insulating glass sealant is cured, apply a commercially available glass glue containing mineral oil in the middle of the sealant, the size is 35 X 35, and the thickness is 0-5 (mm) according to the test design requirements.

2. Test results and discussion  

2.1 Insulating glass test results and discussion

From the comparison of Table (2) and Table (3), it can be seen that after dot coating of glass glue on the outer insulating glass sealant, the inner and outer butyl/silicone insulating glass sealant of the insulating glass is in the color, state, and normal temperature. The odor, elasticity, volatile content, cross-section, and flame combustion properties of the glass have undergone fundamental changes, while the hollow glass that is not coated with glass glue has no obvious internal and external butyl/silicone insulating glass sealant properties. 

Table 2 The test results of testing insulating glass not coated with glass glue

Test itemsInner butyl rubberOriginal Butyl GumOuter silicone glueOriginal glass glue
Color and conditionModerately soft and hard homogeneous clayModerately soft and hard homogeneous clayBlack bright color Bright black color
Smell at room temperatureTastelessTastelessTastelessTasteless
ElasticityCan be pulled into stripsCan be pulled into stripsGenerallyGenerally
Volatilize0.760.800.730.77
Section//There is no oil in the pores of the silicone rubberThere is no oil in the pores of the silicone rubber
Flame burningBlack smoke
yellow flame
Can be directly ignited
No mineral oil odor
Black smoke
yellow flame
Can be directly ignited
No mineral oil odor
White smoke
white dust
good flame retardancy
White smoke
white dust
good flame
retardancy

Table 3 The test results of testing insulating glass for spot coating of glass glue

Test itemsInner butyl rubberOriginal Butyl GumExternal silicone glueOriginal silicone glueGlass glueOriginal glass glue
Color and conditionSticky black ointmentModerately soft and hard homogeneous clayThere is smoke, and the glue turns white after the oily substance volatilizesBright black color
No oil leakage
Semi-translucent milky whiteTransparent milky white
Smell at room temperature Similar to glass glueTastelessSimilar to glass glueTastelessStrong mineral oil smellStrong mineral oil smell
ElasticityComes in the form of a dissolved ointment that cannot be pulledCan be pulled into stripsBetterGenerally

Volatilize9.380.80Silicone glue in direct contact with glass glue 14.41 Silicone glue in ortho-contact with glass glue 2.020.7735.8647.08
Section

There is a small amount of oil in the individual pores of the silicone rubberNo other substances in the pores of the silicone

Flame burningblack smoke yellow flame Can be directly ignited No mineral oil odorblack smoke yellow flame Can be directly ignited No mineral oil odorWhite smoke with a small amount of black smoke
White dust
Good flame retardancy
White smoke
White dust
Good flame retardancy
White smoke with  black smoke
White dust
Can be directly ignited
White smoke with  black smoke
White dust
Can be directly ignited

It can be proved that the change in the properties of the inner and outer butyl/silicone insulating glass sealant on the insulating glass is caused by the dot coating of glass glue on the outer silicone sealant. The following diagrams are used to further intuitively explain the reasons for the dissolution of butyl rubber.

(Illustration 1)

The blank control test "Insulating glass" was made on March 30, 2021, with only internal butyl insulating glass sealant applied at room temperature for 10 days, the edge of the butyl rubber sealing line was smooth and straight, and no butyl rubber was dissolved. Phenomenon. It shows that the original glass, 3A molecular sieve, aluminum spacer frame, and plastic gusset cannot cause the butyl glue to dissolve.

Figure 1 The test result of insulating glass only coated with butyl rubber

Figure 1 The test result of insulating glass only coated with butyl rubber

(Illustration 2)   

The insulating glass was made on March 30, 2021, with only A side coated with glass glue and silicone insulating glass sealant in direct contact. When placed at room temperature for the third day, the butyl glue was dissolved and migrated into the insulating glass spacer. After 10 days at room temperature, the edge of the joint between the aluminum spacer and the butyl glue in the insulating glass spacer showed obvious semi-elliptical spheres or irregularities. Regular zigzag shape, as shown in Figure A, and the remaining three sides where glass glue is not applied, the butyl glue does not dissolve, and the edge of the butyl glue sealing line is still smooth and straight. Explain that the outer insulating glass sealant did not cause the butyl glue to dissolve, but because the mineral oil contained in the indirect contact glass glue gradually migrated to the butyl rubber through the outer silicone insulating glass sealant, dissolving the butyl glue. The base material causes dissolution.

Figure 2 The test result of insulating glass only one side coated with glass glue

Figure 2 The test result of insulating glass only one side coated with glass glue

(Illustration 3)

On March 30, 2021, the four peripheries were coated with 3mm thick glass glue and insulating glass in direct contact with silicone insulating glass sealant. After the glass glue was cured, the insulating glass was placed vertically, with side A on the bottom, and B Face up. When insulating glass is placed at room temperature for 10 days, obvious butyl glue dissolves on the stressed surfaces A and B and migrates into the hollow glass spacer layer into a semi-elliptical or irregular zigzag shape, while the non-stressed surfaces C and D The migration phenomenon in the dissolution of butyl rubber is not obvious. It shows that the migration speed of the mineral oil contained in the glass glue is greatly affected by the external force.

Figure 3 The test result of insulating glass surrounding coated with glass glue

Figure 3 The test result of insulating glass surrounding coated with glass glue

(Illustration 4) 

On March 30, 2021, the insulating glass coated with glass glue on the external silicone insulating glass sealant was placed at room temperature for 10 days. When the butyl glue corresponding to the glass glue was applied, the butyl glue appeared to dissolve and disappear. Migrate into the hollow glass spacer layer into a semi-elliptical shape. It shows that the real culprit for the dissolution of butyl glue is glass glue.

Figure 4 The test result of insulating glass spot coated with glass glue

Figure 4 The test result of insulating glass spot coated with glass glue

2.2 butyl rubber/silicone rubber/glass glue compatibility test results and discussion  

2.2.1 Butyl rubber/silicone rubber compatibility

A certain domestic brand of butyl rubber, a foreign brand of butyl rubber, and Huayna 130 type butyl rubber are cross-phased with a domestic brand of silicone rubber, a foreign brand of silicone rubber, and Huayna type II silicone insulating glass sealant. In the capacitive test, the thickness of the silicone rubber is designed to be 3mm. The test pieces are placed at room temperature for 30 days and heated at 90°C/168h to detect the dissolution of the butyl rubber and the swelling of the silicone rubber. The test results are shown in Table (4). 

It can be seen that the used domestic and foreign butyl rubber and domestic and foreign silicone rubber are placed at room temperature for 30 days and 90℃/168h heat treatment, and there is no dissolution of butyl rubber and swelling of silicone rubber, indicating that the butyl rubber used Glue and silicone glue is completely compatible. 

2.2.2 Compatibility of butyl glue/glass glue

The butyl rubber adopts a certain domestic brand butyl rubber, a foreign brand butyl rubber, and Huayna 130 type butyl rubber. The thickness of the silicone rubber is designed to be 0mm, that is, no silicone rubber is applied but on the butyl rubber. Directly apply 3mm of commercially available glass glue containing mineral oil, and check the compatibility of glass glue and butyl glue at room temperature. The test results are shown in Table (5).

It can be seen that the use of mineral oil-containing glass glue and direct contact with domestic, domestic, and foreign butyl rubber, butyl rubber dissolution occurs in a very short period (less than 2h).

2.2.3 Compatibility of butyl rubber/silicone rubber/glass glue  

2.2.3.1 The influence of glass glue thickness on the compatibility of butyl glue/silicone glue/glass glue

In this butyl glue/silicone glue/glass glue compatibility, butyl glue adopts Huaya 130 type butyl insulating glass sealant with a thickness of 6mm; silicone glue adopts Huaya type Ⅱ insulating glass sealant, The thickness is 7mm; the glass glue adopts commercially available glass glue containing mineral oil. The thickness is designed to be 0mm, 1mm, 2mm, and 5mm. Separate the ground from the butyl rubber, observe the dissolution of the butyl rubber in the separated part, whether there is an obvious substance sticking to the black hand on the finger touch, and observe whether the silicone rubber is abnormal. The test results are shown in Table (6) and Figure (5-7). 
It can be seen from Table (6) that when the thickness of the silicone glue is constant, as the thickness of the coated glass glue increases, the total amount of mineral oil in the glass glue increases accordingly, so more mineral oil enters the butyl group through the silicone glue. Dissolve the butyl rubber, so the time for the butyl rubber to dissolve is shortened, that is, the faster the butyl rubber dissolves. At the same time, the silicone glue in contact with the glass glue has the phenomenon of oiling to varying degrees, that is, the silicone glue is swelled by the mineral oil in the glass glue. When the silicone glue is not coated with glass glue, neither the butyl glue nor the silicone glue has abnormal phenomena. 
Figure  Seven  

2.2.3.2 The influence of the thickness of silicone rubber on the compatibility of butyl rubber/silicone rubber/glass glue

In this butyl glue/silicone glue/glass glue compatibility, butyl glue adopts Huaya 130 type butyl insulating glass sealant with a thickness of 6mm; silicone glue adopts Jinan LIJIANG Glass insulating glass sealant, The thickness is respectively designed as 0mm, 3mm, 4mm, 5mm, 6mm and 7mm; the glass glue is commercially available glass glue containing mineral oil, the thickness is 1mm, and the test piece is placed at room temperature. After every appropriate hour, it is sealed from silicone insulating glass. Slowly separate the rubber edge from the butyl rubber, observe the dissolution of the butyl rubber in the separated part, whether there is an obvious substance sticking to the black hand on the finger touch, and observe whether the silicone rubber is abnormal. The test results are shown in Table (7). 

When the thickness of the glass glue is constant, that is, when the total amount of mineral oil contained in the glass glue is constant, the thickness of the silicone glue increases accordingly, because the mineral oil in the glass glue diffuses into the route of the butyl glue through the silicone glue As a result, the time required for growth is longer, so the time for butyl rubber to dissolve is correspondingly delayed. This phenomenon can also be seen in Table (7). But as the thickness of the silicone glue increases to a certain extent, when the mineral oil in the glass glue reaches the interface between the silicone glue and the glass glue, its content is not enough to cause the butyl glue to dissolve significantly. It is difficult to conclude that it will have a fatal impact on the insulating glass. Without exception, all silicone glues have the phenomenon of oil emission, that is, the silicone glue is swelled by the mineral oil in the glass glue.
From the above cases and the analysis of the test results, the insulating glass frame uses the glass glue containing mineral oil to contact the insulating glass outer silicone sealant. Sooner or later, the inner and outer sealant of the insulating glass will have problems, which will affect the insulating glass. 

Therefore, glass glue containing mineral oil cannot be used for framing of butyl/silicone insulating glass, and such harmful mineral oil cannot be mixed into insulating glass glue for processing insulating glass.

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Jinan LIJIANG Glass Automation Equipment Co., Ltd. serves China's architectural glass and industrial glass industries, specializing in manufacturing energy-saving doors, windows, curtain walls, and hollow glass complete sets of processing production lines and glass deep processing equipment. Jinan LIJIANG Glass Machinery is well-known in the industry for its technological innovation, sincere service, pragmatic and stable corporate style. Its products are distributed in various provinces, cities, and autonomous regions across the country, and are exported to more than a dozen countries and regions such as the United States, Eastern Europe, Southeast Asia, and South Africa. Jinan LIJIANG Glass Machinery is widely recognized and loved by the international and domestic markets.

Jinan LIJIANG Glass Machinery is leading the industry's technological innovation strength, strictly following the ISO9001: 2000 version of the international quality system certification, and making every effort to create professional, high-quality, safe, and standardized high-quality products-three series, more than 20 types of insulating glass and glass deep processing, and The equipment not only meets the needs of users in all aspects of scale, quality, efficiency, etc. but also fully meets the user's personalized design and manufacturing requirements. Among them, the company independently researched and developed through aluminum LJBZ1800P, LJZB2025, LJZB2535 series vertical insulating glass production lines, LJST03 two-component sealant glue machine, LJTB01 insulating glass butyl glue coating machine, and other equipment have reached the advanced level of similar products.


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