Polyamide resin adhesives

Polymers. AH nitro alcohols are sources of formaldehyde for cross-linking in polymers of urea, melamine, phenols, resorcinol, etc (see Amino RESINS AND PLASTICS). Nitrodiols and 2-hydroxymethyl-2-nitro-l,3-propanediol can be used as polyols to form polyester or polyurethane products (see Polyesters Urethane polymers). 2-Methyl-2-nitro-l-propanol is used in tires to promote the adhesion of mbber to tire cord (qv). Nitro alcohols are used as hardening agents in photographic processes, and 2-hydroxymethyl-2-nitro-l,3-propanediol is a cross-linking agent for starch adhesives, polyamides, urea resins, or wool, and in tanning operations (17—25). Wrinkle-resistant fabric with reduced free formaldehyde content is obtained by treatment with... 

Polyamide Resins. Another class of polyamide resins, in addition to the Hquid resins used as epoxy hardeners, are the thermoplastic type, prepared generaHy by the condensation reaction of polyamines with polybasic fatty acids. These resins find use in certain hot-melt adhesives, coatings, and inks. Diamines, typicaHy EDA (233), are the principal amine reactant however, tri- and tetramines are sometimes used at low levels to achieve specific performance. 

Fig. 5. Examples of ihe correlation between measured adhesive strength and (l+cos6). (a) Plot of data from Raraty and Tabor [171J for adhesion of ice to various solids, (b) Plot of data of Barbaris [172] for adhesion of a mixture of epoxy and polyamide resin to low density poly(ethylene) treated in various ways. Both figures from ref. [31], by permission.

Waterborne coatings, 7 127-128, 10 443 Waterborne coating technologies, 10 349 Waterborne contact adhesives, phenolic resins in, 18 784 Waterborne polyamides, 10 400 Water-borne polyurethane coatings,... 

Tall oil is used as a source of turpentine. Tall oil fatty acids are mostly normal C18 acids, 75% mono- and diunsaturated, with lesser amounts of saturated and triunsaturated constituents. Tall oil is also used for waterproofing agents, dimer acids, polyamide resins for printer s ink, adhesives, detergents, and agricultural emulsifiers. 

Backing and Tear-repair. The methods and materials proposed for lining include the following (a) mulberry paper attached with starch (rice or wheat), methylcellulose, or carboxymethyl-cellulose adhesives (18 19), (b) contemporary tapa attached with starch or cellulose-derived adhesives (20 21), (c) nylon laminating tissue and heat-set polyamide resin (22) and (d) stitched backings. 

Polymers Unsaturated fatty-acid chains offer opportunities for polymerisation that can be exploited to develop uses in surface coatings and plastics manufacturing. Polyunsaturated fatty acids can be dimerised to produce feedstocks for polyamide resin (nylon) production. Work is also ongoing to develop polyurethanes from vegetable oils through manipulation of functionality in the fatty-acid chains, to produce both rigid foams and elastomers with applications in seals, adhesives and moulded flexible parts (see Chapter 5 for more information). 

As with amidoamine and polyamide cured adhesives, epoxy resins cured with aliphatic amines exhibit tensile shear strength that is dependent on the type of filler and concentration. Table 11.10 shows the effect of filler loading on strength of a simple general-purpose, room temperature curing epoxy adhesive composed of liquid DGEBA epoxy mixed with 10 pph of a tertiary amine. 

Use Modifier in alkyd and polyamide resins, polyester or metallic soap for petroleum additive, emulsifying agent, adhesives, shellac substitute, to upgrade drying oils. 

The primary components used to make polyamide-based hotmelt adhesives are copolyamides with PA 12 and so-called polyamide resins. 

According to the chemical structure of the hot-melt adhesive polymers (polyamide resins, saturated polyester, ethylene vinyl acetate copolymers, polyurethanes), the processing temperatures range between 120 and 240 °C. 

Fluid Polyamide Resin Chemistry Thermoset Coatings Thermoset Adhesives... 

The first polyamides from these polybasic acids or their corresponding esters were described by Bradley and Johnston (1) and subsequently by Falkenburg et al. (2), These chemists recognized that polyamide resins have unusual solubility in lower alcohols and that films, deposited from alcohol solution, have good water resistance, strong adhesion to various surfaces, and other... 

The polyamide resins melting above 100 C, which result from the condensation of ethylenediamine or related higher molecular weight diamines with dimer acid, find application in industry because of their film-forming and adhesive properties. These will be discussed in detail later. 

Because of this steep viscosity drop, solid polyamide resins are useful as hot melt adhesives. The resins may tend to "skin" or oxidize when exposed to air and high temperatures for long periods. However, this negative property can be circumvented by the use of antioxidants and by proper application equipment design. 

Coating formulations and properties have been detailed in technical bulletins (31). The epoxy-polyamide system is popular because it provides an unusual degree of inherent corrosion resistance. This will be discussed in detail later. The system is unusually tolerant as compared to related systems, such as amine cured, since the ratio of components is not particularly critical. Tolerance is also demonstrated because it may be applied to wet surfaces and to surfaces with tightly bound rust. Indeed, formulations are available that may be applied under water to structures such as submarines and off-shore oil well riggings. Both the corrosion resistance and the tolerance relative to application on poorly prepared wet surfaces are believed to be functions of the surface activity of the polyamide resin. Related also to the surface activity are the unusually strong adhesive properties that the system demonstrates with a broad range of substrates. 

Useful film-forming resin adhesives include polyvinyl esters and ethers and their copolymers and interpolymers with ethylene and vinyl monomers, acrylic resins and their copolymers, polyvinyl alcohol, water dispersion of polyolefin resins, polystyrene copolymers such as polystyrene butadiene, polyamide resins, natural rubber dispersions, and natural and modified carbohydrates (starch or carboxycellulose). Particularly preferred for use are aqueous dispersions of polyvinyl acetate and vinyl acetate-ethylene copolymers. 

Hot-melt polyamide resins are obtained by the reaction of diamines with diacids. While in their simplest form polyamides are the reaction of a particular diamide with a particular diamine, most of the polyamides used in adhesive formulations are complex reaction products obtained by combining several diacids and diamines to obtain the particular properties required. The most common diacid used is a dibasic acid obtained by polymerizing oleic or linoleic acid or other unsaturated fatty acids. This acid can be represented as HOOC—R—COOH, where R is a hydrocarbon residue of 34 carbon atoms and of indeterminate configuration. Commercial forms of this dimeric diacid also contain preparations of products obtained by polymerization of three or more molecules of... 

The basic resins need some form of modification to achieve (1) suitable application viscosities, (2) flexibility, and (3) reduction in costs if possible. Suitable polyamide resins (those of the more flexible variety) are thus frequently modified by the addition of EVA copolymer (high-viscosity, high-melt-point grade). The amount of EVA that can be added is restricted to a maximum of 25% in most cases because of compatibility problems. The blend is then further modified with selected tackifying resin addition and small quantities of filler, to reach an optimum balance of performance properties. To achieve maximum adhesion, it is common for polyamide hot melts of this type to be used in conjunction with a polyamide resin solution primer system for edging material. The primer is invariably a dilute solution of the base polyamide resin. 

Chem. Descrip. 1,2-Diaminocyclohexane CAS 694-83-7 EINECS/ELINCS 211-776-7 Uses Intermediate epoxy curing agent chelating agent for oil field, textiles, water treatment, detergents herbicide intermediate polyamide resins for adhesives, coatings, films, plastics, inks PL) for extenders, catalysts corrosion/scale inhibitors... 

Uses Surfactant for industrial applies., lubricants in prod, ot solid and liq. reactive polyamide resin compositions for crosslinking polyesters to enhance toughness and flexibility defoamer in food-contact coatings, paper/paperboard food pkg. adhesives, coatings, paper, cellophane, polymers... 

Chem. Descrip. N-Ethyl o/p toluenesulfonamide CAS 80-39-7 EINECS/ELINCS 201-275-1 Uses Plasticizer for adhesives, paints, printing inks, epoxy resins, polyamide resins, phenolics, melamine resins, nitrocellulose lacquers, PVAc, EVA, cellulose acetate Imparts improved adhesion, increased flexibility at lower temps.. Improved gloss, oil resist., stability at higher temps, to adhesives and coatings... 

Chem. Descrip. o,p-Toluenesulfonamide-formaldehyde resin CAS 1338-51-8 EINECS/ELINCS 215-667-5 Uses Modifier and adhesion promoter for syn. and natural resins used in adhesives and coatings applies. extender in polyamide resins food pkg. adhesives, paper, cellophane Reguiatory FDA 21CFR 175.105,176.170,177.1200 Properties Pract. colorless hard solid particles, faint formaldehyde odor sol. in usual lacquer soivs. Insol. In water, aliphatic hydrocarbons, veg. oils sp.gr. 1.35 soften, pt. 62 C ref. index 1.4275-1.4325 (25 g/75 g butyl acetate)... 

Uses Plasticizer for polyamide resins, some cellulose compds., emulsion adhesives, pkg., caulk, printing ink, surf, coatings synthesis of dyes, pharmaceuticals, other organic chemicals in resin mfg. Manuf./Distrib. Aarti Ind. Ltd Advance Coatings Aldrich Allchem Ind. ... 

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