Current situation and development prospects of silicone sealants for construction

1

Silicone Sealants Overview

Silicone sealants are silicone based products, which are of great value due to their strong adhesion and tensile strength, as well as their weather resistance, vibration resistance, moisture resistance, adaptability to large changes in heat and cold, and ease of construction, combined with their wider applicability to a wide range of scenarios, enabling bonding between most common building material products. It is commonly used for filling gaps between structures, material bonding and a variety of other applications. Silicone sealants are also commonly referred to as “room temperature adhesives” as they cure at room temperature by reacting with water in the air to form an elastic silicone rubber.

Product Recommendation: excel sealant manufacturers

2

Classification and applications

Silicone sealants can be divided into structural and general sealants depending on their performance. Since structural adhesives are mainly used for bonding between building materials and the main structure of the building, such as glass curtain walls, the materials not only need to withstand the wind load and the self-weight load of the glass, but also need to meet the standard modulus of elasticity, so its technical content is high. Ordinary sealants, on the other hand, are used in common scenarios in our daily lives. In recent years, as people’s living standards have risen, sealants with antibacterial and anti-mould components have become increasingly popular with consumers.

Depending on the chemical properties of the material, they can also be divided into deacidified, dealcoholised and deketoxime types.

Acid-free (acidic sealants) are most commonly used because of their fast curing speed and high adhesive strength, and are suitable for sealing, plugging and leak-proofing, weatherproofing, etc. However, acetic acid is produced during the curing process, which can be corrosive to metal materials.

Dehydrated (neutral sealant) curing process to avoid the production of acid, although the bond is strong, but there is a relatively slow curing speed of weaknesses.

Deketoxime type is mainly used for structural adhesives, such as glass curtain wall, hollow glass structural adhesive sealing and other fields.

Silicone sealant in China began to be used in large quantities in the 1980s. The varieties are mainly acidic silicone sealants, which are also the largest varieties in use, mainly in the construction field. Due to the rapid urbanisation process in China, glass curtain walls, aluminium curtain walls and stone curtain wall materials can be developed rapidly, the requirements for adhesive sealing materials are also correspondingly increased, promoting a large number of applications of sealants.

3

Supply and demand pattern

In the early years, China was still blank in the field of structural adhesives, and almost all imported products were used. Since China’s accession to the WTO, Chinese sealant enterprises have achieved rapid development along with the rise of the silicone industry. Through the construction of laboratories, the establishment of product quality monitoring and assurance systems, and the improvement of after-sales services, the gap between the quality of domestic leading sealant enterprises and foreign brands of sealants has narrowed considerably. Domestic enterprises have made use of their keen market sense and cost advantages to rapidly conquer the city, and the product range has been greatly enriched, and a positive development trend has been formed in which R&D and sales are mutually promoted.

At present, China’s room temperature adhesive apparent consumption of about 1 million tons, the industry market size of about 30 billion yuan, of which the construction of silicone sealant consumption accounted for about 58%. It is understood that the world’s largest consumer of silicone sealants are the construction industry, in the United States, Japan and Europe, the construction of room temperature adhesive consumption accounted for 44%, 38% and 40% of the total consumption of the region, accounting for a relatively low China. The application of room temperature adhesives in the construction sector mainly includes the sealing of building curtain walls, housing buildings and the processing of energy-saving glass for doors and windows, China is still in the urbanisation development stage, which is the fundamental reason for the relatively high proportion of room temperature adhesive consumption in the construction sector in China. According to SAGSI data, in 2020 China’s room temperature adhesive in the construction sector consumption structure: 43.7% of building curtain walls, doors and windows sealing and decorative decoration 35.8%, hollow glass processing 20.5%.

On the supply side, China’s silicone sealant industry currently has a low start-up rate, with an annual production capacity of over 1.5 million tons/year and an output of about 1.04 million tons; the annual export scale is about 50,000 tons, while the import scale is less than 10,000 tons.

Overall, there is a structural imbalance between supply and demand in China’s silicone sealant industry, with a certain reliance on imported products in the high-end market and an oversupply in the mid- and low-end markets, and a large export scale.

4

Manufacturers

According to the annual inspection list of qualified products issued by the Aluminum Door and Window Curtain Wall Committee of the China Construction Metal Structure Association and the Curtain Wall Engineering Committee of the China Construction Decoration Association, the number of enterprises certified and recommended by industry organizations in 2021 reached as many as 107, and the number of silicone sealant manufacturers in the industry is estimated to be more than 300.

The market is mixed to varying degrees, with silicone brands distributed from high-end to low-end as follows

First-line foreign brands: Wacker, Tao Xi (Dow Corning), Sika, Maitu, Henkel Baide, etc.

First-line national brands: Silicon Power, Baiyun, Zhijiang, Zhongyuan, Jitai

Second-tier national brands: Huasil, Yongan, Baolongda, Qisda, Hongying, Olya, Coats, Jianhua, Lingzhi, etc.

Third-class brands: other brands certified by the China Construction Metal Structure Association, about 80 brands.

Class IV brands: small manufacturers who have not passed the certification of the industry association.

At present, the market share and brand reputation of outstanding domestic brands are basically recognized by consumers and local engineering customers.

5

Development trend

Nowadays, China is vigorously advocating energy-saving buildings, especially the development of assembly-type buildings for the sealant materials demand pull is more obvious, but the real estate industry continues to maintain the pressure of macro-control is not reduced, it is estimated that the application of sealants in the construction field will maintain a low growth rate.