Adhesive industry

Hydrocarbon resin is a broad term that is usually used to describe a low molecular weight thermoplastic polymer synthesized via the thermal or catalytic polymerization of coal-tar fractions, cracked petroleum distillates, terpenes, or pure olefinic monomers. These resins are used extensively as modifiers in the hot melt and pressure sensitive adhesive industries. They are also used in numerous other appHcations such as sealants, printing inks, paints, plastics, road marking, carpet backing, flooring, and oil field appHcations. They are rarely used alone. 

Terpene-based hydrocarbon resins are typically based on natural products such as a-pinene, P-pinene, and ti-limonene [5989-27-5] which are obtained from the wood and citms industries, respectively. These resins, which were originally the preferred tackifiers for natural mbber appHcations, possess similar properties to aHphatic petroleum resins, which were developed later. Terpene-based resins have been available since the mid-1930s and are primarily used in the adhesives industry. 

Adhesive Transfer Processes. Many polymers, whether dehberately or accidentally, are adhesives, so that much of the adhesive industry can be regarded as a part of the mbber and plastics industry. However, there are several important material-transfer appHcations involving polymer products that are so critically dependent on controlled adhesion that they merit specific mention in that category. They include hot stamping foils, release coatings for pressure-sensitive adhesive products, photocopier materials, transfer coatings, and transfer printing of textiles. 

Today a very wide range of acrylic materials is available with a broad property spectrum. The word acrylic, often used as a noun as well as an adjective in everyday use, can mean quite different things to different people. In the plastics industry it is commonly taken to mean poly(methyl methacrylate) plastics, but the word has different meanings, to the fibre chemist and to those working in the paint and adhesives industries. Unless care is taken this may be a source of some confusion. 

Esterification. The esterification of rosin provides important commercial products for the adhesive industry. Rosin esters are formed by the reaction of rosins with alcohols at elevated temperatures. Because the carboxyl group of the resin acids is hindered by attachment to a tertiary carbon, esterification with an alcohol can only be accomplished at elevated temperatures. This hindrance is in turn responsible for the high resistance of the resin acid ester linkage to cleavage by water, acid and alkali. 

Progress in research and development in the wood-based industry and in the adhesive industry has shown many successes during the last decades. On the other hand, many industrial requirements still require considerable and important developments in this area. The main driving forces today are cheaper , quicker and more complex . The first two are caused by the heightened competition in the above-mentioned industries and the attempt to minimize costs while maintaining a certain level of product quality and performance. The key word more complex stands for new and specialized products and processes. Adhesives play a central role in wood-based panel production. The quality of bonding, and hence the properties of the wood-based panels, are determined mainly by the type and quality of the adhesive. Development in wood-based panels, therefore, is always linked to development in adhesives and resins. 

Both the wood-based panel industry and the adhesive industry show a high commitment to and great capability towards innovation. The best evidence for this is the considerable diversity of types of adhesives used for the production of wood-based panels. Well-known basic chemicals have been used for a long time for the production of the adhesives and their resins, the most important ones being formaldehyde, urea, melamine, phenol, resorcinol and isocyanate. The greater portion of the currently used adhesive resins and adhesives for wood-based panels is produced with these few raw materials. The how to cook the resins and the how to formulate the adhesive become more and more complicated and sophisticated and are key factors to meet today s requirements of the wood-based panel industry. 

Chain compositional heterogeneity is of particular relevance to functional copolymers which find widespread use in the coalings and adhesives industries.13,240,246 In these applications, the functional copolymer and a crosslinking agent are applied together and are cured to form a network polymer. The functional copolymers are based on functional monomers with reactive groups (e.g. OH), it is desirable that all copolymer molecules have a functionality of at least two. Nonfunctional polymer will not be incorporated and could plasticize the network or be exuded from the polymer. Monofunctional polymers are not involved in crosslink formation and will produce dangling ends. 

The wastewaters generated by the adhesive industries contain high concentrations of both carbon and nitrogen compounds. The process chosen to treat these wastewaters will depend on their COD/N ratio. When the COD/N ratio is high, an anaerobic treatment is the best option as it will save costs... 

Selective epoxidation of one of the double bonds in dialkenes is of practical interest (Table XVI). Although monoepoxides predominate at low H2O2 concentrations, the diepoxides are also formed at higher concentrations. The diallyl epoxides of bisphenol A are major intermediates in the adhesives industry, and their synthesis in solid-catalyzed reactions in an eco-friendly manner remains a challenge. 

The Solvent Emissions Directive was adopted in March 1999 by the European Council of Ministers and should be implemented by member states within two years. The adhesives industry uses about 130,000 tonnes of solvents in its products annually and has a key role to play in meeting the Directive s targets. The main impact of emissions reduction will be on adhesives coaters because the adhesive film forms through the evaporation of solvent. For adhesives manufacturers, the main issue is the reduction of fugitive emissions. Both oxidation and recovery are well proven abatement techniques. BELGIUM EUROPEAN COMMUNITY EUROPEAN UNION WESTERN EUROPE... 

The two major uses of phenol in 1995 were the production of bisphenol-A (35%) and the production of phenolic resins (34%) (CMR 1996). The largest use for bisphenol-A is as an intermediate in the production of epoxy resins (Thurman 1982). Phenol-formaldehyde resins comprise over 95% of this market (Thurman 1982). The plywood adhesive industry required 26% of the total production of phenolic resins in 1977. These low-cost, versatile, thermoset resins have other major uses in the construction, automotive, and appliance industries (Thurman 1982). 

The variety of applications emphasizes the versatility of naphtha. For example, naphtha is used in paint, printing ink, and polish manufacturing and in the rubber and adhesive industries, as well as in the preparation of edible oils, perfumes, glues, and fats. Further uses are found in the dry-cleaning, leather, and fur industries and in the pesticide field. The characteristics that determine the suitability of naphtha for a particular use are volatility, solvent properties (dissolving power), purity, and odor (generally the lack thereof). 

PVAc, PVA and PVB are used in a vast number of different applications [19]. The most common use of PVAc-based dispersions and dispersible polymer powders is in the construction and adhesives industry. The polymeric binders are used as... 

Milled wood lignin was mixed with the crude enzyme solution of Tram-ties versicolor extracellular phenoloxidases produced on spent sulfite liquor in a ratio of approximately 2 1. This comprised the main part of the two-component bio-adhesive. Industrial particles were bonded with 15% bioadhesive under conventional pressing conditions to have 19 mm particle boards (40 x 50 cm) of the properties described in Table IV. The bonding reaction (crosslinking) took place in aqueous solution at room temperature. If conventional pressing technology is applied, the temperature should be elevated in order to maintain water evaporation within a reasonable press time. 

Cationic polymerization processes are most important in the coatings and adhesive industries. No commerical use of the dye sensitized processes are known, but direct UV curing is extensive. 

The above-mentioned processes yield CPVC which is suitable for conversion into rigid articles the homogeneous solution processes, however, yield products used in the fiber and adhesive industries (15). 

One of the most abundant biopolymers available in nature is starch. Starch is a polysaccharide consistent of glucose monomers and is found in all green plants. Next to its occurrence in food and its use in food-related industries, the major application of starch is in the paper industry, followed by the adhesives industry. 

Formulators in the adhesives industry do not normally manufacture epoxy resins. Generally, formulators buy epoxy resins, modify them with other materials, do similar compounding to the curative, and then package the product as a complete adhesive system ready for the end user. There are many excellent textbooks6-8 available giving information about the preparation, chemistry, and use of epoxy resins in general applications. It is not the intention here to go into such detail but to focus only on epoxy adhesive systems. 

When considered against the criteria listed above, epoxy adhesive systems provide a well-balanced set of properties. This solidifies their competitive position in the adhesives industry. 

Analysis of the epoxy adhesive markets is difficult because so many market segments fragment the industry and because it is difficult to confine manufacturers, distributors, and end users into specific categories. However, there are several organizations that periodically publish market reports on the adhesives industry including epoxy adhesives.14... 

In the epoxy adhesive industry, fillers are generally added as a batch process rather than a continuous process. Batch systems are especially suited to short-run operation in which additives and materials are often changed. They allow for greater control of residence time, shear, and temperature, and they can accommodate a feed rate that is not free-flowing. 

Edward M. Petrie has been active in the adhesives industry for over 37 years—both in the formulation and the end-use sides of the industry. He has BS (Chemical Engineering) and MS (Polymer Science) degrees from Carnegie Mellon University and an MBA from Duquesne University. 

This book is aimed primarily at the formulator, but it is sometimes difficult to define who the formulator actually is. Often the end user may also need to formulate an epoxy adhesive from raw materials in order to reduce cost or because of the uniqueness of the application. Thus, I hope that the end user as well as those involved in other aspects of the adhesives industry (purchasing agents, designers, manufacturing engineers, etc.) find this book interesting and worthwhile. 

New Energy Saving Reactive Acrylic Liquid Polymers for the Pressure Sensitive Adhesives Industry... 

Most of the raw materials used in large quantities in structural adhesives are used because they are widely available, relatively safe, and inexpensive. Quite often they are made in large quantities for uses other than adhesives and the adhesive manufacturers have taken advantage of supply and price. Few new basic raw materials are being developed specifically for the adhesive industry although the traditional raw materials are being combined in new ways to enhance desired adhesive properties. New initiators, adhesion promoters, primers, and specialty chemicals are being developed for use in small quantities to provide wider application latitude and improved performance. 

The adhesives industry is the third most important market for rosin. Rosin, modified rosins, and rosin derivatives are used in several types of adhesives, including the pressure-sensitive, hot-melt, and elastomer-based latices, and solvent rubber cements. 

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