Adhesives used in the shoe business, cloth shoes, shoes of cloth used shoe glue basically self-preparation, the vast majority of the remaining adhesive outsourcing. Currently, the country has produced shoes with adhesive manufacturers more than 200, including more than 100 located in coastal areas, is generally accompanied by a shoe factories base. Guangdong is China's largest footwear production base, the current annual output of 3 billion pairs of footwear export two billion pairs. Guangdong shoe factory is also the country with the largest adhesive, a total of more than 70, most of them are foreign-funded enterprises in these adhesive factory which has about half the production of export goods (and export shoe matching). Guangdong shoes with firm size on the glue has more than 30 levels, for example Haenam light, the South China Sea tyrants, Zhongshan Weiming other companies were more than 10,000 tons of production scale, a few dozens of varieties, including Haenam Light Company production capacity of several tons, and its products into almost all the major footwear production base, leather products production base. Fujian Province, Zhejiang Province, each with about 40 companies producing shoes with adhesive. Jiangsu Province, Shandong Province, Tianjin, each with more than 10 companies producing shoes with adhesive.

    Among all kinds of shoes with adhesive to stick gum outsole is crucial, adhesive highest performance requirements, but also footwear companies, manufacturing enterprises are most concerned adhesive adhesive varieties. Currently sticky adhesive outsole whether at home or abroad, basically polyurethane, neoprene-based. In view of the shoe for other purposes adhesives low-tech and technology is more mature, less impact on the industry, therefore, the following main comments sticky rubber outsole.

    Adhesive performance outsole

    In all shoe adhesives, adhesive performance requirements of external bottom up, so it should have the following properties:

    1) of the heterogeneous material having sufficient adhesive strength to adapt to the application of new materials;

    2) proper drying speed, good tack to accommodate high-speed production needs;

    3) to reach the final (maximum) time is shorter adhesive strength;

    4) layer (film) has sufficient resistance to bending properties, heat resistance, water resistance, cold resistance, used for light-colored rubber outsole shoe also requires yellowing resistance, resistance requirements for bonding plasticized PVC material agent;

    5) low toxicity, in order to meet the requirements of relevant laws and regulations;

    6) sizing process is simple, easy to operate, flexible and adjustable cycle.

    Development rubber outsole

    The earliest adhesive sticky outsole is used nitrocellulose glue, can only be used leather uppers and leather bottom bonding. With the synthesis of new materials used in footwear, plastic is not suited to the nitrocellulose.

    After 1932 there neoprene, rubber-based adhesives have been widely used, it can not only be bonded leather and leather, but also be able to rubber and leather bonded together, in 1939 the company first performed in Germany COMPO rubber sole and leather the bonding process was slow crystallization neoprene, poor tack accordingly, to achieve the ultimate bond strength long time, resulting in the application is not widespread in shoe production. After the 1957 Bayer introduced rapid crystallization neoprene, neoprene adhesive makes widely used bonding outsole possible. The early 1960s, Bayer invented the polyurethane adhesive, neoprene unable to solve the sticky PVC, PU shoe problem. The late 1960s, thermoplastic rubber (TPR) to enter the footwear industry, which is a hard sticky material, then in addition to (halogenated) after treatment with polyurethane adhesive TPR at the end, there had been direct bonding adhesive with SBS SBS (TPR) bottom and vulcanized rubber sole. SBS is a hot glue because activated, the operation inconvenient to use, and its vitality is not long, rubber outsole market has always been occupied by a neoprene and polyurethane. Primer foreign countries choose different varieties, mainly in Western Europe and the United States to use polyurethane rubber, Asian countries, Eastern Europe and Australia, and multi-purpose neoprene.

Whether neoprene or polyurethane glue, basically solvent. Organic solvents on rubber, plastic material has a very good penetration, but toxic, flammable, polluting the environment. The early 1970s to the mid-1980s, there have been attempts to study the climax of hot melt adhesive to bond the outsole, however, a serious lack of respect due to the adaptability of the material, adhesive strength and sizing equipment, etc. exist, this attempt has failed to achieve industrialization. 1980s, the German research and development with a polyurethane adhesive dispersion. Mid-1980s, the European launch of solvent-free reactive polyurethane hot melt adhesives, also for various reasons over the years is still not able to achieve industrialization. Therefore, solvent-based dominance outsole rubber is not shaken.

    Neoprene Adhesives

    The molecular structure of regular neoprene adhesive, cohesive and strong, is a crystalline polymer, with a strong polarity, for a variety of materials with good adhesion properties, widely used. Neoprene adhesive has the following characteristics:

    1) without curing has a good cohesion, good initial tack, after being dried glue stick material upon contact there a strong adhesive strength;

    2) bonding the soft material, the expansion can alleviate the stress concentration caused by contraction;

    3) there are good water resistance, aging resistance, flex, for a variety of materials have good adhesion and reliable performance;

    4) solvent-based neoprene manufacturing process is simple, easy to operate, low prices.

    Because of neoprene inexpensive, used in the production of footwear outsole with neoprene rubber has long been based. However, since the 1980s, with the shoes with diverse materials, the quality of bonding have higher requirements, the first generation of ordinary neoprene adhesive can not fully meet the requirements of the substrate adhesion, appears the grafted neoprene, the requirements for different materials, there is a dollar graft neoprene, binary, ternary and quaternary copolymers, basically solved the various vulcanized rubber sole, TPR bottom and upper bond issue of . However, for bonding PVC and PU bottom of the die, still have to use PU glue to fix the problem.

    The solvent used in the first neoprene benzene, excellent solubility, adhesive properties are more easily controlled, but the considerable toxicity of benzene, after the user in a number of toxic deaths instead of toluene as solvent. Toxicity of benzene toluene, although much smaller than, but still serious poisoning if inappropriate measures the operator and the pollution of the environment. In the 1980s, was once gasoline, ethyl toluene mixed solvent instead of the majority or all instead of Toluene, but increased costs, adhesive performance is unstable, irritating odor heavier workers are not willing to use, plus the time environmental, labor laws and no special emphasis must not use toluene, therefore, no benzene solvents neoprene has not promote open. The mid-1990s, some footwear production base in multiple occurrences of workers affected by triphenyl poisoning, even after an accident resulting in the death of leukemia, restrict the use of increasingly strong voice triphenyl glue. Fujian Provincial Environmental Protection Agency to develop and publish the Fujian Provincial Environmental Protection product approval technical conditions - shoes with adhesive, defined by the product of the raw materials into benzene, halogenated hydrocarbon content; China Green environmental certification mark established by the Committee shoes with adhesive green flag standards, restrictions on the use of BTEX. In this context, there are a number of units produced in succession without triphenyl of neoprene, polyurethane rubber. Because plastic does not contain toluene solvent mixture used is higher than the price of containing triphenyl prices, making the finished adhesive 10-20% price increase, many manufacturers, especially small and medium still containing triphenyl shoe adhesives, workers poisoning incidents still occur. March 2002, Hebei baigou luggage business due to the use of adhesives containing triphenyl (component adhesives and shoes with plastic almost), with poor ventilation, or no ventilation, causing many workers appear leukemia, paralysis, death after the case was disclosed CCTV, causing the central leadership attaches great importance to instruct relevant departments of the National luggage, footwear and related corporate reorganization to investigate the situation with glue containing triphenyl adhesive has been greatly restricted, some of the company's products were ordered out of the market. Therefore, with the enhancement of environmental protection, pollution poisoned intensified, including triphenyl of neoprene will become less and less, or even be eliminated.

    The early 1980s to the early 1990s, some of our units have been carried out research chloroprene latex used in footwear production, bonding footwear parts, stretch last, sip side, including heel, etc., but trying to stick outsole efforts have not been successful.