Clear coat formulation

Cationic and photolatent base clear coat formulations curing in shadowed areas... 

As reported in Table 26, poly(MAPO) and poly(MAPO-co-MMA) systems are found [124] to display a higher photoinitiation activity in clear coating formulations, expressed in terms of half-time of the curing process, essentially due to their shorter induction period, as compared with the structural model PIVPO. The polymeric systems, therefore, appear to be preferable for their higher productivity in clear coatings formulations. 

A key example is demonstrated by Ranjbar and Rastegar [26], who focused on varying nanosilica particle types of acrylic-melamine clear-coat formulations. A marked improvement in the modulus (coefficient pertaining to physical property) and hardness was observed by the incorporation of nanosilica particles, irrespective... 

Using present ideas of glass structure, frits can be formulated to have maximum durability. Zirconia enamels have a lower than optimum acid resistance, but titania enamels have superior durability at low pH values. Encouraging crystallisation in the enamel enhances mechanical strength and therefore chemical resistance by reducing the incidence of damage sites which act as foci for attack. The addition of an extra (clear) coat on to the top most coat of enamel gives superior chemical resistance". 

Coating formulations (lacquers) are clear, transparent, low-viscosity, solvent-free liquids that are stable with a shelf life of several months and are suitable for optical applications ranging from the ophthalmic to the optical fibre market. As an example of the former, Figure 4.15 shows a plate half coated with a layer of ABRASIL coating material only a few micrometres thick with the scratch traces from steel wool being observed on the uncoated half.18... 

As previously discussed, food effects are an important parameter for enteric-coated systems, especially for drugs, that are sensitive to food. Pancreatic enzyme-containing products fail when they come in contact too early with lipids, proteins, and carbohydrates present in food. The clinical efficacy of pancreatic enzymes formulated as enteric-coated tablets was investigated in man and dog [44], The enteric materials examined were hydroxypropyl methylcellulose phthal-ate (HPMCP), cellulose acetate phthalate (CAP), and the methacrylic acid copolymer USP/NF Type C. In vivo behavior monitored by x-ray scintigraphy showed clear differences between the three coating formulations. HPMCP-coated products adhered to the gastric mucosa, whereas CAP and methacrylate copolymer... 

The pharmaceutical and biological availability of eight commercial furose-mide preparations was compared including two products with modified release properties [67], an enteric-coated tablet and a sustained-release preparation, in the form of a capsule containing diffusion pellets [28], A correlation between the rate of dissolution of different techniques and the area under the plasma concentration time curve was documented. The sustained-release preparation and the enteric-coated formulation clearly showed different pharmacokinetic behavior compared with conventional tablets. Although the literature mentions the maximal absorption at pH 5.5, the modified release formulations only showed a relative bioavailability of 80%. 

Moisture Protection of SEPIFILM LP Water vapor transmission rates were measured on free films, including titanium dioxide (Figure 27). SEPIFILM LP shows significantly lower moisture permeability compared to regular or PVA-based coating formulations. Removal of titanium dioxide (SEPIFILM LP clear) improves moisture resistance. 

The enteric materials examined were hydroxypropyl methylcellulose phthal-ate (HPMCP), cellulose acetate phthalate (CAP), and the methacrylic acid copolymer USP/NF Type C. In vivo behavior monitored by x-ray scintigraphy showed clear differences between the three coating formulations. HPMCP-coated products adhered to the gastric mucosa, whereas CAP and methacrylate copolymer... 

The initial approach should be to first identify which formulation properties are critical for its in vivo function. Thereafter, all potential physiological factors that may influence this function should be identified and the correlation between the animal and man regarding those factors should be considered. For example, in the case of a pH-dependent enteric-coat formulation, the dissolution of the coating layer will clearly be a critical formulation variable. The pH in the stomach and small intestine, as well as gastric emptying, will all be critical variables. If the correlation of such parameters with man is poor for all available animal models, there is no rationale for performing such studies if the deviations cannot be accounted for when interpreting the results. 

Applications. Clear phenolic varnishes find use today in industrial coatings as food can linings and maintenance primers and in trade sales coatings as general-purpose clears, floor varnishes, and premium exterior clears. Many of the cooked phenolic varnish can coatings formulations have not changed in the last 40 years, but some cold-cut systems have come into use. The excellent wetting and... 

In the second example (Table 2), two acrylic adhesive formulations are compared. The first contains a hydrogenated rosin ester tackifier, which shows relatively good UV stability. This tackifier can be replaced by one of lower stability (and lower cost), such as the nonhydrogenated rosin ester, by the incorporation of the appropriate light stabilizers. As these data show, some improvement in stability is seen when a BTZ is used at 0.5% (or a combination of BTZ/HALS at 0.25%/0.25%), but the best stability is achieved when the adhesive is stabilized with a HALS at the same level (0.5%). It should be pointed out that BTZs are commonly used in films and coatings (e.g., automotive clear coats) when the objective is to protect the material below the film. Similar applications can be imagined where UVA-containing adhesive films are used to screen and protect other substrates. 

The laminate sheet is a flexible decorative sheet for use in surfacing an automobile body panel. The laminate revealed in this invention contains several layers, including clearcoat, tie coat, color coat, and adhesive layer. Clearcoat is formulated from polyvinylidene fluoride (to assure excellent weather resistance), tie coat is formulated from acrylic (good adhesion to both clear coat and color coat and weather resistance), color coat was formulated from PVC (see formulation in the above table) and adhesive was pressure sensitive acrylic formulation. 

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