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Materials Engineering

A waterproof glue

Sealant with high adhesive power has various applications in civil construction and in consumption

HÉLIO DE ALMEIDAWithout any advertising campaign, in just three months of 2005, 3 thousand tubes were sold of the adhesive Pesilox, a glue with high power of adhesion and resistant to water. The purchases came to over R$ 100 thousand, and were made mainly by customers who accessed the website of Adespec – Adesivos Especiais, a company operating on the premises of the Technological Researches Institute (IPT), in São Paulo. The installations are limited to two modest rooms, one occupied by the director of the company, chemical engineer Wang Shu Chen, and the other by the reactor, a piece of equipment where the chemical substances that make up the formulation are processed until they are transformed into a viscous white liquid, ready to be packaged. The two are separated by corridors in which the walls act as a sort of display, occupied by various materials, such as plaster, wood, mirrors, and Formica, glued with the adhesive.

Adespec’s success story began in the beginning of 2001, when it started its activities, housed in the Technological Companies Incubation Center (Cietec), installed in University City in São Paulo. But what motivated the creation of a company to develop new problems was a health problem faced by Wang some months before, when she was still working as development manager of a major manufacturer of adhesives. After dedicating herself for over two decades to research centers of multinationals from the sector, she went to work in a company that basically produced solvent-based adhesives and saw the number of white cells in her blood, the cells responsible for the defense of the organism, fall 30% in just three months, as a consequence of her proximity to the solvents, like toluene, ethyl acetate etc. “And that was despite not having direct contact with these products, due to the position I held”, the researcher says.

The health problem made her begin to study the relationship between the solvents and their effects on the human organism and on the environment. “I found that there are laws in various parts of the world that restrict or prohibit the use of these products, while in Brazil the initiatives to this effect are timid, in spite of advances in recent years”, she says. As each kilo of solvent-based adhesive is made up of 800 grams of solvent, this means that when the product is applied to put Formica onto a cupboard, for example, the chemical substance keeps evaporating in the air for a long time, with damages to the environment and to health.

In the same phase in which she was carrying out her studies on the theme, the researcher had contact with some customers that were looking for alternatives to the solvent-based adhesives sold in Brazil. This combination of factors was essential for the development of adhesives, waterproofers and sealants with high performance and competitive costs, without solvents or any other volatile organic compound.

The first concrete result arose in 2003, when the company launched the Prego Líquido glue, which does not use solvents or toxic substances in its formulation, and eliminates the need for drilling, screwing, or nailing. The product can be employed in civil construction for fixing baseboards, decorative moldings, pictures, mirrors and PVC conduits. It is also used in plasterboard walls, which are very porous and do not take plugs, screws or nails, for fixing floors of ceramics or wood, gluing Formica, polystyrene and walls with tiles.

Although the fixing occurs immediately after the application, the complete drying process, also called curing, takes from one to three weeks, because the product is water-based. It is worth the wait. Prego Líquido resists temperatures of 200 to 250° without any problem. The tests to corroborate the properties of the product, such as resistance to traction, impact, aging and impermeability, were done at the laboratories of the Technological Researches Institute and the Institute of Nuclear Energy and Research (Ipen). In the same year in which it launched Prego Líquido, Adespec went on to the graduate category at Cietec and became an associated company. That was when it entered into a technical cooperation agreement with the IPT, which allows the company to occupy a temporary space on its premises.

With the commercial launch of the product, the company went on to dedicate itself full-time to the development of Pesilox Fixtudo, a more advanced sealant adhesive that replaces, with advantages, silicone and polyurethane, and brings additional properties. “Pesilox serves to glue all materials, including floors subject to washing and in areas with a heavy traffic of people”, says Wang. The main differential of the adhesive in relation to Prego Líquido is the drying time, far quicker. There are various formulations, with drying times that range from nine minutes to one hour, depending on the application. To develop Pesilox, Adespec went in with a project at FAPESP, under the Small Business Innovation Research Program (PIPE), which made it possible to buy a reactor and to start the pilot plant for researching adhesives and seal nts free of solvents and based on high performance polymers, the siloxane polyethers.

Prize-winning career
In the short career since its creation in 2001, Adespec has been awarded many prizes. The last of them was handed over at the end of November during the Investors in Sustainable Business Forum II, promoted by the New Ventures Brazil Program, because of the business model shown and for its contribution to sustainable development in Brazil, because the glues it produces do not harm the environment and the consumers. Another two companies were also awarded prizes: Tramppo Lighting, which works with the recycling of light bulbs and is a resident of the Technological Companies Incubation Center (Cietec), and Empresa Brasileira de Reciclagem, from Santos, which uses recycled plastics to replace wood in civil construction.

The New Ventures Brazil Program is an initiative of the World Resources Institute (WRI), run in Brazil by the Sustainability Studies Center of the Getúlio Vargas Foundation (FGV) in partnership with Banco ABN Amro Real and Natura. Acting in Latin America since 1999, the program rewards sustainable enterprises by granting technical support in the formulation of business plans and the stimulation of private investments in the sector. During the form, the business plans of the enterprises selected were presented to a jury made up of specialists, responsible for the choice of the winners. Also in 2005, Adespec was amongst the winners of the Southeast regional stage of the Finep Technological Innovation Award, Small Business category, granted by the Financier of Studies and Projects, of the Ministry of Science and Technology. In 2004, one year after coming out of the incubator at Cietec, the company was given the National Anprotec Award for the Best Graduated Company, granted by the National Association of Entities Promoting Innovative Enterprises.

A practical display of the resistance of the material are the thousands of feet that every day cross the floor for disembarkation from trains at the Luz station of the São Paulo subway, where it was applied. Comparative tests carried out with sealants found in the market showed that Pesilox glues metal, plastic, wood, cloth, granite and stone, all of them efficiently. “It is the only water-based glue”, says Wang. This property makes it possible to repair broken tiles in swimming pools in clubs, hotels and condominiums without the need to empty them. You just have to dive in and glue the damaged piece. One of the advantages of Pesilox in relation to the sealants found in the market is that, in contact with humidity and water, the product applied does not increase in size, nor does it form bubbles. The formula has not been revealed by the researcher, but the basis of the composition is modified polyether. The formulation also includes plasticizers and antioxidants, besides stabilizing and light-absorbing agents and a catalyst.

As the product solidifies when coming into contact with the humidity of the air, the environment where it is prepared has to be dry. That is why care is needed to take it out of the reactor, when it is put into another piece of equipment, manufactured to measure to separate the liquid that will be put into the packaging.  Pesilox can also be used in industry and in civil construction as a sealant and a building movement joint existing between two walls or with the roof. When applied as a sealant in a sink or bathroom floor, for example, it also has the advantage that it can be painted. The product can be applied with a spatula or with a brush, and the excesses are easily removed with a dry cloth, paper, or even with the hand.

New formulations
Besides the 360-gram packages of Pesilox, with the standard product, other formulations are on the way to arrive on the market, with different drying times for the product, depending on the application. They were developed on the basis of demand from companies, and for the time being they will only be supplied to order. Tests have shown that the product can also be used to glue trainers, cloth, Velcro, and in various household uses. They are applications that have already attracted the attention of venture capital investment funds and of an American plastic laminate multinational, which is carrying out gluing tests with Pesilox.

The pilot plant installed at the IPT will manage to produce the quantity necessary for the product to be distributed in the market in other formats, like aluminum packagings with a smaller quantity. For the time being, two batches of 52 kilos each are coming out of the reactor on a daily basis, sold mainly to builders or consumers that seek Adespec out. For the coming year, the plans include commercial distribution in the major retail chains. Essential for this was the company’s choice to join the Research in Companies Support Program (Pappe), an initiative of the Ministry of Science and Technology (MCT), run by the Financier of Studies and Projects (Finep), in partnership with Fapesp.

The funding from the Pappe, which is intended for the production stage of the product, was used for the purchase of a reactor capable of producing per day two batches of 100 to 150 kilos each of Pesilox. The market is promising. A survey carried out by the researchers shows that the domestic consumption of glue in Brazil is about 80 million tubes a year. “From our calculations, we believe that it is quite viable for us to occupy 10% of this market, or 8 million tubes a year”, says Wang.

The Project
Development of adhesives and sealants based on silyl-terminated polyethers for use in industry and civil construction  (nº 01/09239-9); Modality Small Business Innovation Research Program (PIPE); Coordinator Wang Shu Chen — Adespec; Investment R$ 345,424.00 (FAPESP) and R$ 500,000.00 (Pappe-MCT)