Transparent Resins Research Articles

Polymeric optical mixing rod coupler

Optical mixing rod couplers have been fabricated using extruded plastic tubing filled with optically transparent casting resins to form a waveguide-type mixing region. Asymmetric (1*19) splitter/combiners with plastic fiber and plastic-clad silica fiber pigtails have been made with efficiencies greater than 60% and power uniformities within 1-dB standard deviation. Tested as a combiner, the coupler had an average loss of -1.6 dB with a standard deviation of 0.71 dB. Tested as a splitter, it had an average loss of -14.9 dB with a standard deviation of 0.9 dB, and the excess loss was -2.0 dB. The results suggest that the coupler would be useful in a variety of short-distance optical interconnection applications where multimode step-index fiber is appropriate. It may also offer a higher yield than some competing, more complex techniques.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Epoxy resins for deep UV lithography

AbstractA negative resist based upon photo‐acid initiated cationic polymerization of an epoxy resin (1, 2) was reported in the early eighties with the advent of onium salts (3–5). An efficient acid generating onium salt, triphenylsulfonium hexafluoroantimonate (6), absorbs light in the deep UV producing acid upon direct photolysis in this region of the spectrum. The resin component of such a negative resist system must be optically transparent over the exposure wavelengths to obtain vertical image profiles. Another difficulty often encountered with crosslinking negative resists is swelling of the crosslinked matrix during development with organic solvents. This swelling manifests itself in distorted images and/or complete adhesion loss, especially when submicron features are involved. Our goal has been to address these problems and develop an organic developable deep UV resist capable of providing submicron images. Optically transparent commercial resins, styrene‐allyl alcohol copolymers, have been converted to glycidyl ethers, thereby providing cationically polymerizable functionalities. Careful choice of the resin was made to obtain reactive ion etch resistance, thermal stability, good adhesion, and coating properties. The synthetic procedure and characterization of the epoxy resin will be presented. The effect of the molecular weight distribution upon swelling during development and general solubility properties also will be discussed. Resist formulations exhibited sensitivities of 19 to 30 mJ/cm2 on a Perkin Elmer 500 in the deep UV (UV2) mode. The electron beam sensitivity is 3 to 5 μC/cm2 at 20 KeV. Submicron images have been generated in both optical and electron beam lithography.

タフト法によるスプール弁内の流れの可視化と画像処理

In designing spool valves which are widely used in hydraulic power applications, one of the most important problems is to estimate and reduce the axial force acting on the spool of the valve. This axial force can easily be estimated from momentum theory if the behavior of the jet issuing from the metering orifice of the spool valve is expected.In the present paper, a three-dimensional model of the spool valve has been designed to observe the flow near the metering orifice. This model is made of transparent acrylic resins. The jet issuing from the metering orifice is visualized by a tuft method. The images of flow fields recorded by CCD camera are fed into a microcomputer and an digital image processing is employed to investigate the behavior of the jet.

2 スプール弁絞りからの噴流

In designing spool valves which are widely used in hydraulic power systems, one of the most important problems is to estimate the axial force exerted on the spool of the valve. This axial force can easily be estimated from momentum theory if the geometrical shape of the jet issuing from the metering orifice of the spool valve can be obtained.In the present paper, a two-dimensional variable orifice was designed to observe the flow near the metering orifice of a spool valve. This orifice was partly made of transparent acrylic resins. The steady jet issuing from the metering orifice was visualized by means of air bubble method. The unsteady jet was also visualized by varying the width of the orifice sinusoidally. Photographs of the unsteady jet were taken by a high speed camera (16mm movie camera).

Electrical Failure Properties of Cast Epoxy Resins

Impulse and ac breakdown properties of transparent cast epoxy resins are reported having either a castin needle electrode or a needle-shaped recessed gold film electrode deposited by vacuum evaporation or sputtering, given a divergent electric field. Dielectric breakdown always initiates from the needle tip where the electric field strength is the highest. The dielectric breakdown process, which consists of tree initiation, tree propagation, and the complete puncture of the cast epoxy resin is investigated. This process varies considerably with the wave form of the applied voltage. Chemical analysis by Fourier transform infrared spectroscopy (FTIR) indicates that chemical reactions caused by voltage application take place in the epoxy during the induction period until the initiation of the tree. The dielectric breakdown strength is considerably influenced by the electrode configuration, and also by resin formulation.

Epoxy Resins IV: The Stability of the Epoxy-Triethanolamine Borate System

Abstract The diglycidyl ethers of bisphenol-A, phenolphthalein, and bisphenol-fluorenone were cured with triethanolamine borate to give transparent resins. Curing studies at 160° were made. Comparative properties of the respective epoxy resin systems including T g, hydrolysis resistance, thermal degradation and oxygen index flammability data are reported.

Studies of Nitrogen—Phosphorus Compounds. XXIX. Synthesis and Thermal Stability of Phosphorus Diamide Nitride Resins

The synthesis of resins by the reaction of trimeric or tetrameric phosphorus diamide nitride (NnPn(NH2)2n, n=3, 4) with formalin (CH2O), and the possibility of the formation of co-condensation resins through the addition of urea (CO(NH2)2) or melamine (C3H6N6) in the above reaction system have been investigated. Moreover, the thermal stability of resins has been studied by the DTA and TGA methods. In the NnPn(NH2)2n—CH2O system (n=3, 4), the rate of gelation increased with a decrease in pH, and remarkably accelerated with an increase in temperature. A mixture of these components in a suitable molar ratio was neutral and gelatinized gradually at 50°C within a period of 1—4 h. The gelatinous product was converted into a transparent resin at 80°C. The proper quantities of formalin were 7.5—9 and 16—20 mol to 1 mol of N3P3(NH2)6 and N4P4(NH2)8, respectively. The rate of gelation for the tetramer was distinctly greater than that of the trimer variety. In the N3P3(NH2)6—CO(NH2)2—CH2O and N3P3(NH2)6—C3H6N6—CH2O systems, the transparent resins were obtained in molar ratios of 1:2.5—10 and 1:1—20 of urea and melamine to the trimer variety, respectively. The resin of NnPn(NH2)2nCH2O system was found to be P 23—26%, and N 29—33%. The resin formed by the addition of urea or melamine naturally decreased the P content, while the N content did not vary appreciably. The thermal decomposition of resins reacted with NnPn(NH2)2n shifted more to the lower temperature side than did the urea—formalin and melamine—formalin resins. However, their carbonized residues formed remarkably, checked the spread of fire, and were incinerated at about 80°C.

Transparent barrier resins with high nitrile content

AbstractThe effect of 30–49 wt‐% nitrile group content on the properties of copolymers is demonstrated. The nitrile is furnished by either acrylonitrile or methacrylonitrile. The exceptional resistance of such high nitrile content resins to the passage of gases and of solvents is shown and variations therein demonstrated for different comonomers. Transparent, tough, grafted polymers of good color are described which retain these properties. These qualities, combined with low second‐order transition temperatures and adequate heat deflection temperatures, provide polymers of interest wherever containment and barrier are desired. Bottles, thermoformed containers, etc., could benefit from the use of some of the polymers described.