Aqueous Washable Thermal Resistant Coatings and Adhesives

2018 ◽  
Vol 2018 (1) ◽  
pp. 000767-000772 ◽  
Author(s):  
John Moore

Abstract Many packaging processes require thin and fragile components to be protected or held securely in place for temporary periods of time. The most common process flow is to: apply the coating, cure or use to bond a device, conduct the process, and finish with removing the coating by washing in a liquid chemistry. Aqueous cleaning is deemed safer for devices on organic laminates and in the presence of molding compounds. These reagents use water as their major constituent. They are compatible with organic substrates (panels, laminates, boards), are worker safe, and require less expensive operating equipment. Aqueous washing is generally green and exempt from the complexity and cost of environmental and waste management regulations. Daetec's washable coatings qualify as green, and exhibit thermal resistance over 300°C, making them one of the most unique materials on the market. These coatings enable soldering, laser processing, plasma etching, and dielectric curing, all following with simple water washing. Water washable DaeCoatTM 525 is a key choice in laser processing for debris removal around the heat activation zone (HAZ), while the etch-resistant DaeCoatTM 534 supports laser patterning for plasma singulation [1]. While DaeCoatTM 532 is water soluble, another material from the same family, DaeCoatTM 537 is not, yet will wash away in an aqueous surfactant, DaeClean™ S20 (10% in water). In many ways, these products act, as surfactants, but depending upon the chemistry, will dissolve in water or an aqueous agent. Customers desiring a green protective coating or adhesive for plating or etching processes, may apply DaeCoatTM 537, send through the processes, and then wash away in the S20 aqueous agent. All products are cast from water. Film forms as 50μm thick with peel away liners are available for DaeCoatTM 532 and 537. UV curable high solids versions are also available. Applications include planarizing coatings, adhesive for die solder attach, and C4 or micro bump protection. Protective coatings for EMI/RFI shielding, dicing operations, and temporary bonding operations that may use porous carriers have been demonstrated with water washable coatings and adhesives. The success in these and related temporary applications depend upon the use of the proper washable coating. Our experience in creating solutions for these and other industry needs will be discussed as well as the criteria for using temporary washable coatings.

Author(s):  
D.R. Mattie ◽  
J.W. Fisher

Jet fuels such as JP-4 can be introduced into the environment and come in contact with aquatic biota in several ways. Studies in this laboratory have demonstrated JP-4 toxicity to fish. Benzene is the major constituent of the water soluble fraction of JP-4. The normal surface morphology of bluegill olfactory lamellae was examined in conjunction with electrophysiology experiments. There was no information regarding the ultrastructural and physiological responses of the olfactory epithelium of bluegills to acute benzene exposure.The purpose of this investigation was to determine the effects of benzene on the surface morphology of the nasal rosettes of the bluegill sunfish (Lepomis macrochirus). Bluegills were exposed to a sublethal concentration of 7.7±0.2ppm (+S.E.M.) benzene for five, ten or fourteen days. Nasal rosettes were fixed in 2.5% glutaraldehyde and 2.0% paraformaldehyde in 0.1M cacodylate buffer (pH 7.4) containing 1.25mM calcium chloride. Specimens were processed for scanning electron microscopy.


1965 ◽  
Vol 43 (1) ◽  
pp. 30-39 ◽  
Author(s):  
C. T. Bishop ◽  
M. B. Perry ◽  
F. Blank ◽  
F. P. Cooper

A group of polysaccharides, called galactomannans I, were precipitated as their insoluble copper complexes from aqueous solutions of the crude polysaccharides obtained from each of the organisms designated in the title. The five galactomannans I were homogeneous under conditions of electrophoresis and ultracentrifugation and had high positive specific rotations. The major constituent monosaccharide was D-mannose; amounts of D-galactose ranged from nil for the polysaccharide from T. rubrum to 13% for that from T. schönleinii. Methylation and hydrolysis of the five galactomannans I yielded varying amounts of the following: 2,3,5,6-tetra-O-methyl-D-galactose (not present in the products from T. rubrum), 2,3,4,6-tetra-O-methyl-D-mannose, 2,3,4-tri-O-methyl-D-mannose, 2,4,6-tri-O-methyl-D-mannose, 3,4-di-O-methyl-D-mannose, and 3,5-di-O-methyl-D-mannose. Periodate oxidation results agreed with the methylation studies. The gross structural features of each galactomannan I appear to be the same, namely, a basic chain of 1 → 6 linked α-D-mannopyranose units for approximately every 22 of which there is a 1 → 3 linked α-D-mannopyranose residue. Branch points occur along the 1 → 6 linked chain at the C2 positions of the D-mannopyranose units and once in every 45 units at the C2 position of a 1 → 6 linked D-mannofuranose residue. The D-galactose in the polysaccharides is present exclusively as non-reducing terminal furanose units; non-reducing terminal units of D-mannopyranose are also present. The variations in the identities and relative amounts of the non-reducing terminal units were the only apparent differences in the gross structural features within this group of polysaccharides.


2010 ◽  
Vol 14 (06) ◽  
pp. 499-508 ◽  
Author(s):  
Manuela Carchesio ◽  
Lucia Tonucci ◽  
Nicola d'Alessandro ◽  
Antonino Morvillo ◽  
Piero Del Boccio ◽  
...  

Water-soluble, metal-tetrasubstituted phthalocyanines ( -SO3H , MPcS and -COOH , MPcC) of platinum and ruthenium were synthesized and their photostability to visible light irradiation was determined. For the ruthenium phthalocyanines, the characteristic visible Q band of the phthalocyanines was almost totally suppressed after five days of irradiation. The platinum derivatives were instead more resistant to photodegradation, and the Q band did not decrease by more than 25%. The addition of carbonyl compounds to the phthalocyanine solution in water (at concentrations at least 1400-fold those of the phthalocyanines) dramatically accelerated the photobleaching of these phthalocyanine complexes. PtPcS turned from blue to green and to colorless with one day of visible-light irradiation in the presence of acetone. This effect decreased with the increase in molecular weight of the ketones (from acetone to 2-pentanone). The addition of alcohols (i.e. 1-butanol) or other organics (i.e. phenylacetic acid) did not affect the photostability of these metal-tetrasubstituted phthalocyanines. Dioxygen also had an important role, as when the solutions of phthalocyanines were carefully deaerated before irradiation, the visible spectra were preserved. The platinum phthalocyanines, as with the palladium analogs, sensitize the photoproduction of 1O2 , as shown by the formation of endoperoxide and its rearranged products in the presence of furfuryl alcohol (a singlet oxygen trapping agent).


2021 ◽  
Vol 28 ◽  
Author(s):  
Phuong H.L. Tran ◽  
Thao T.D. Tran

: Lipid-based formulations have recently been investigated as a promising approach to enhance the bioavailability of drugs, especially poorly water-soluble drugs. The encapsulation of lipid-based formulations in porous materials can result in a transformation of liquids or semisolid forms to solid dosage forms. Moreover, the specific structure of porous carriers could offer an enhanced ability to load and control active pharmaceutical ingredients. Although there have been prominent reports on lipid-based formulations and porous materials as promising technologies for controlled drug release, the overall methods of encapsulating lipid-based formulations need to be discussed for further formulation investigations. This review aims to present the key strategies used for producing porous carriers containing lipid-based formulations. We also discuss methods that enhance the encapsulation efficiency of loaded drugs within porous structures (instead of lipid-based formulations). Moreover, the critical factors that affect tablet formation are outlined. This overview of lipid-based formulations encapsulated within porous materials provides a summary of the technical methods used in the development of these formulations and their clinical translation.


1994 ◽  
Vol 53 (13) ◽  
pp. 1833-1835 ◽  
Author(s):  
J. Rayss ◽  
W. M. Podkoscielny ◽  
J. Widomski ◽  
A. Gorgol

2013 ◽  
Vol 821-822 ◽  
pp. 925-928
Author(s):  
Lei Wang ◽  
Xiao Juan Lai ◽  
Shao Yun Ma

Waterborne UV curable polyurethane emulision containing C=C bond was prepared with self-emulsification. 3% water soluble photoinitiator was added to the polyurethane emulision, and polyurethane films was prepared by ultraviolet irradiation. The structure of the polyurethane emulision and films were confirmed by means of Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and thermogravimetric analysis. FTIR test result shows that cross linking and solidification reaction of C=C double bond happened after UV irradiation. When C=C content increases, the particle size of polyurethane emulision increases, crosslinking degree of films increases, water resistance and heat resistance have both been improved. When C=C content is 8.51%, gel content is more than 90% and the lowest water absorption can be 12.5%.


1987 ◽  
Vol 65 (12) ◽  
pp. 3084-3092 ◽  
Author(s):  
K. Black ◽  
J. Meredith ◽  
B. Thomson ◽  
J. Phillips ◽  
T. Dietz

Steady-state fluxes of 22Na+ were measured as a function of external Na+ concentration across locust recta mounted as flat sheets under short-circuit conditions. A net flux [Formula: see text] at all concentrations confirmed that absorption was an active process obeying Michaelis–Menten kinetics with Kt of 17 mM and Vmax of 1.5 to 2.5 μequiv. cm−2 h−1. [Formula: see text] was not affected by cAMP, was independent of external Cl− levels and stimulated short-circuit current (i.e., Cl− transport), and was partially inhibited by amiloride and ouabain but not by vanadate. Using intracellular electrodes, a small Na+ conductance that was not due to cotransport with organic substrates was identified in the apical plasma membrane. A semiquantitative model for Na+ absorption in this epithelium is proposed. We surveyed the locust neurosecretory system for water-soluble factors that might control rectal Na+ reabsorption.


1997 ◽  
Vol 77 (4) ◽  
pp. 579-587 ◽  
Author(s):  
G. Masciandaro ◽  
B. Ceccanti ◽  
C. Garcia

A vermicompost (VC) from biological sludges was incorporated into two soils, or applied on their surfaces as mulch with the addition of worms (Eisenia foetida) or grass seeds (Lepidium sativum) in the experiments of "living mulch". The purpose of this research was to study the influences of different methods of organic matter application on soil chemico-physical and biochemical properties. Two texturally different soils from a Mediterranean climate, a clayey and a sandy soil, were tested in laboratory-scale experiments. Water-soluble C (WSC), NO3-N/NH4-N ratio (nitrification index), and enzyme activities (BAA-protease, dehydrogenase, and β-glucosidase) were taken as indices of soil biochemical fertility as they are related to soil physical properties and microbial activities. Surface cracking area in both soils increased, with the formation of small–medium (<1000 µm) cracks. The positive changes in cracking, the high index of nitrification, and the evolution of WSC provided evidence for high metabolism in mulched soils. Enzyme activity was similar in living mulch and control soils, and was highest when VC was directly incorporated. Significant correlations (P < 0.05) occurred between enzyme activities, organic substrates, and soil cracking area for both soils. The selected parameters were indicators of the different practices of organic matter application. Key words: Vermicompost, mulching, soil enzymes, soil cracking


Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1556
Author(s):  
Paulina Bednarczyk ◽  
Agnieszka Wróblewska ◽  
Agata Markowska-Szczupak ◽  
Paula Ossowicz-Rupniewska ◽  
Małgorzata Nowak ◽  
...  

This work presents studies on the obtaining of UV-curable coatings with antimicrobial activity. Urethane acrylates (UAs) have excellent physicochemical properties including high reactivity in systems with radical photoinitiators in the presence of UV radiation and good balance between hardness and flexibility in the formed coatings. At the same time, eugenol is well known as the compound hindering the growth of various microorganisms. Hence, the materials obtained by the modification of UA resins with eugenol can be used to protect various surfaces, especially against microorganisms. This study aimed to examine the influence of the amount of eugenol on the chemical, physical, thermal, and mechanical properties of the obtained UA coatings and find the conditions at which the optimal properties for industrial applications such coatings can be achieved. These materials were successfully obtained. Taking into account that eugenol is a very cheap reactant, and it can be obtained from natural sources by the simple distillation method, the proposed method combined the good points of obtaining protective coatings by UV curing with the utilization of vegetable, renewable reactants (biomass), such as components giving special properties to these materials, in this case, antimicrobial properties. In this study, photoreactive coatings with antimicrobial properties for the following microorganisms: fungi (C. albicans), Gram-positive bacteria (S. epidermidis) as well as Gram-negative bacteria (E. coli), were obtained. The obtained coatings were cured over a short time. They were colorless and characterized by a wide range of properties and applications.


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