PVC Paste Resin is a unique liquid form of PVC plastic in the unprocessed state. Due to its fine particle size, its texture is like talc powder, which is non flowable. It is often mixed with plasticizers and stirred to form a stable suspension to make PVC paste
1、 Overview and Definition
PVC paste Resin is a unique liquid form of PVC plastic in the unprocessed state. Due to its fine particle size, its texture is like talc powder, which is non flowable. It is often mixed with plasticizers and stirred to form a stable suspension to make PVC paste.
The polymerization production methods of PVC paste resin mainly include micro suspension polymerization, seed lotion polymerization and mixing method. Among them, lotion polymerization PVC paste resin is mainly leather material, also known as large plate material; The PVC paste resin produced by micro suspension polymerization, also known as glove material, is mainly made of vinyl chloride monomer. Due to the low viscosity and good stability required for glove specific resins, most of the glove materials currently used in the domestic market are produced using the micro suspension method.
Preparation method, process, characteristics, and main application fields of PVC paste resin
Lotion method
The lotion polymerization formula mainly includes VCM, water, water-soluble initiator and emulsifier. Lotion polymerization has strict requirements on agitation. The initiation is carried out in the water phase. The commonly used initiator is water-soluble persulfate. Generally, the particle size of lotion obtained by emulsion polymerization is less than 0.2 μ m. In order to increase the particle size of the emulsion, the lotion seed polymerization method was developed to increase the particle size of the emulsion to 1.0 μ About m. In lotion polymerization, if there is generated high polymer latex, control the material ratio and conditions. In principle, VCM will only polymerize on the generated latex particles, and no new particles will be formed; The generated polymer latex is like crystal seed, so it is called "lotion seed polymerization". But only a reasonable particle size is not enough. It is necessary to have an appropriate particle size distribution in order to obtain PVC paste resin with excellent performance. Emulsifier is very important in lotion polymerization. The amount used determines the number of initiator particles and plays a major role in the final size of latex particles. Especially when producing seeds, using high initiation rate and low concentration emulsifiers can narrow the particle size distribution of latex.
Lotion PVC paste resin is mainly used in wallpaper and foam industry
Micro suspension method
Microsuspension polymerization is a relatively new method for preparing PVC paste resin, which was industrialized as early as the mid-1960s. The process is as follows: first, a portion of VCM (5%) is mechanically homogenized to form a stable emulsion with a particle size of 1.0 μ About m), and then polymerize (oil soluble initiators must be selected). The PVC paste resin produced by this method has excellent flowability, low emulsifier dosage, and improved thermal stability and water resistance of the resin. The production process needs to pay special attention to the following influencing factors: selecting appropriate composite emulsifiers and particle improver systems; Homogenization of components in the polymerization system; Mixing speed; The ratio of water to monomer is appropriate.
Micro suspension PVC paste resin is mainly used for gloves, artificial leather, floor rolls, conveyor belts, and toys
Mixed method
The mixed PVC paste resin production process is mainly a combination of lotion polymerization and micro suspension polymerization. In the whole reaction process, seeds after lotion polymerization and other emulsifiers, initiators, various additives and VCM are added to participate in the reaction. In the mixing method, C16 and C18 straight chain alcohols are mixed with sodium dodecyl sulfate or lauric ACID amine to form an emulsifier to form a micro lotion, and polymerization is mainly carried out in micro drops. After lotion polymerization, seeds were added to make the whole particle size become a bimodal distribution.
The mixed PVC paste resin is mainly used for artificial leather, floor leather, wallpaper, etc
2、 Supply Market Analysis
Due to the low entry threshold of PVC paste resin and the large number of enterprises entering, the industry has experienced overcapacity. However, in 2020, due to sudden public health emergencies, a surge in downstream demand drove multiple enterprises to expand production. In 2021, production capacity rebounded to 1.535 million tons.
In terms of production, according to data, the production of PVC paste resin in China increased from approximately 670000 tons to 1.044 million tons from 2012 to 2021.
3、 Demand Market Analysis
The development of the PVC paste resin industry has provided a new type of liquid material that can be transformed into PVC products only by heating. This liquid material has convenient configuration, stable performance, easy control, convenient use, excellent product performance, good chemical stability, certain mechanical strength, easy coloring, etc. It is widely used in the production of artificial leather, enamel toys, soft trademarks, wallpaper, paint coatings, foam plastics, etc.
With the rapid development of downstream markets such as synthetic leather and automotive interiors, the overall demand for PVC paste resin in China has maintained growth. According to data, the demand for PVC paste resin in China has increased from 880300 tons in 2012 to 1542500 tons in 2021.
4、 Technical Patent Analysis
As the domestic economy gradually enters a stage of high-quality development, the overall number of patent applications for PVC paste resin industry in China has increased, and the industry development will enter an important window period from scale growth to quality improvement. According to data, the number of PVC patent applications in China continued to increase from 2013 to 2020, dropping to 21267 in 2021, a year-on-year decrease of 21.75%. From 2022 to present, the number of domestic paste resin patent applications is 9296.
