1, preface
The success of polymer modified asphalt waterproofing membrane depends not only on its own quality, but also on the bonding and sealing between the membrane and the roof. The traditional construction method of modified asphalt waterproofing membrane is hot melt construction. The asphalt on the surface of the membrane is heated and melted, and then bonded to the roof. This construction method is not only labor intensive, but also pollutes the environment. If the construction technology is slightly improper, the adhesive seal between the membrane and the roof or the lap joint of the membrane will be lax, resulting in roof leakage. Therefore, people began to study and apply self-adhesive polymer modified asphalt waterproofing membrane.
China resin online, new fashion, welcome! ~ self-adhesive modified asphalt adhesive is an important raw material for producing modified asphalt waterproofing membrane. It has the advantages of high strength, high elongation, good adhesion, good flexibility at low temperature, self-healing, convenient and fast construction, etc. Adhesive is not only the bonding layer between the covering material and the roof, but also the stress buffering and absorbing layer between the coiled material and the roof. When the roof cracks due to stress, the adhesive layer has plasticity and considerable ductility, which can buffer or absorb the roof stress through its own deformation, thus reducing the influence of roof deformation on the covering materials, thus prolonging the service life of the coiled material and solving the problem of difficult construction of traditional coiled material.
2. Main raw materials
2. 1 asphalt, as the main component of adhesive, is the key to determine its adhesiveness. When selecting asphalt, plasticity, elasticity and adhesion should be considered comprehensively, and low softening point asphalt is generally selected.
2.2 Modified asphalt is fragile at low temperature and easy to flow at high temperature. Adding modified asphalt can improve its low temperature flexibility and heat resistance. Thermoplastic elastomer SBS has not only the fluidity and thermoplasticity of plastic, but also the elasticity and toughness of rubber. It has incomparable advantages over other modified materials and becomes the first choice of modified materials.
2.3 tackifier tackifier can improve the adhesion and wettability of asphalt, and improve the bonding strength between self-adhesive modified asphalt adhesive and adherend. The selected tackifiers are mainly rosin, terpene resin and petroleum resin [3]. 2.4 The purpose of using talcum powder and light calcium carbonate as fillers in modified asphalt is to reduce cost and reinforce, and at the same time adjust viscosity.
3, production technology and product performance
3. 1 adhesive basically contains 40% ~ 65% asphalt additive, 5% ~ 25% SBS, 5% ~ 30% tackifier, 2% ~ 25% filler, and 10% ~ 30%.
3.2 preparation method: firstly, heat and dehydrate the asphalt, add the dehydrated asphalt into a stirring tank, add additives, then raise the temperature to 180 ~ 2 10℃, add SBS, and stir for 60 ~ 90 min to completely melt SBS, or melt the mixture of asphalt and SBS with a colloid mill; After SBS is melted, the tackifier is added and stirred for 30 minutes. Finally, the filler is added and stirred evenly, which is the self-adhesive modified asphalt adhesive.
3.3 Production process flow
3.3 Performance test The performance of self-adhesive modified asphalt adhesive was tested by GB/T4507- 1999 and JC863-2000, mainly testing its softening point, bonding peel strength between coils, shear strength and shear strength between bonding coils and substrate. The peeling strength is bonded to the sample of 200mm× 150mmSBS modified asphalt waterproofing membrane, and the bonding area is 200mm×25mm；; ; The shear strength between rolls is to draw an area of 300mm× 100mm on a 300mm×200mm roll sample, and then cut it into five 300mm×50mm samples after bonding; The shear strength of the coiled material and the base course is 150mm×50mm, and the coiled material is bonded to the cement mortar sample, and the bonding length is100 mm. Except the softening point, all other samples are tested at room temperature for 7 days. See table 1 for the performance test results.
4. Factors affecting the adhesion performance
4. The ductility and wax content of1asphalt have an important influence on the bonding performance. Except that the ductility of asphalt is required to be greater than 100cm at 25℃, the wax content is not easy to be too much, otherwise it will directly affect the bonding performance. In addition, the solubility of asphalt also has some influence. The asphalt used should not contain too much asphaltene, free carbon and mechanical impurities to ensure the adhesion of the adhesive.
4.2 When SBS is used to modify asphalt, the miscibility between asphalt and SBS is more important. The so-called good miscibility means that asphalt and SBS with moderate melting index are ideal. SBS is a block copolymer of styrene (S) and butadiene (B), in which butadiene is a soft segment; 2- terminal styrene is a hard segment, which aggregates into physical cross-linked regions. Different block ratios (S/B) have a certain influence on the adhesive properties.
4.3 tackifier
(1) Rosin The molecular structure of rosin contains both hydrogenated phenanthrene nucleus with good compatibility with hydrocarbons and carboxyl group with high polarity, so it has good compatibility with elastomers. The tackifying effect of rosin is good, but because the resin acid of rosin contains * * * yoke double bonds, it has high reactivity, instability and easy oxidation.
(2) Polyterpene resins used as tackifiers are mainly а-х-ene or β-х-ene resins, and their solubility and compatibility are not as good as those of rosin, especially the resins with high softening point are incompatible with polymer compounds with polydisperse molecular weight, but still have good compatibility with SBS asphalt. The tackifier of terpene resin is slightly worse than rosin, but it has better oxidation resistance and heat resistance.
(3) Petroleum resin aromatic hydrocarbon Petroleum resin has poor compatibility with SBS and is generally not used as tackifier. Aliphatic petroleum resin is the main tackifier, but its tackifying effect is not as good as rosin and terpene resin.
Considering the bonding performance, high and low temperature performance and cost factors, it is best to choose the mixed tackifying system of rosin and terpene resin. In a certain range, the tackifying effect of mixed tackifier system increases with the increase of tackifier dosage, but beyond this range, the tackifying effect is not obvious, and the heat resistance of modified asphalt adhesive will also be affected.
4.4 The surface-treated active filler is the best filler. Because the surface of active filler particles can combine with polymer chains to form a cross-linked structure, when one of the molecular chains is stressed, the stress can be dispersed to other molecular chains through cross-linking points; If one of the chains is broken, the other chains can still work, and all chains will not be endangered immediately, so the mechanical properties of modified asphalt can be improved.
5. Application of self-adhesive modified asphalt adhesive The specific manufacturing method of self-adhesive polymer modified asphalt waterproofing membrane is to roll-coat a layer of self-adhesive modified asphalt adhesive on the surface of modified asphalt waterproofing membrane with a thickness of about 0.5 ~ 0.8 mm, and then spread a layer of release paper.
During construction, the release paper can be removed and pasted on the roof, and the laying can be completed at one time, which can reduce the construction process, improve work efficiency and shorten the construction time, and can be combined with various coiled materials to increase the thickness of waterproof layer. If the covering coil is damaged due to poor aging resistance, the self-adhesive layer can still maintain good waterproof and sealing effect, thus preventing leakage and saving manpower, material resources and financial resources consumed by decoration.
The detailed information of "self-adhesive polymer modified asphalt waterproofing membrane adhesive" can be found in Zhong Da Consulting & Construction, and all relevant construction materials you want are available.
For more information about project/service/procurement bidding, and to improve the winning rate, please click on the bottom of official website Customer Service for free consultation:/#/? source=bdzd