Over the 100 years since its discovery, liquid crystals have been the intriguing subject for both academia and industries. The textbook of de Gennes The Physics of Liquid Crystals published in 1974 is still the bible for many LC researchers, but new subjects unmentioned in the book have also risen for these years. This chapter describes the story of the recent developments and the future perspectives in physics of liquid crystals, especially focusing on the contributions by Japanese research groups for the last decade.

Physics of Liquid Crystals

A positive resist composition comprising: at least one compound selected from a compound capable of generating an acid represented by the formula (I) as defined herein upon irradiation with actinic rays or radiation and a compound capable of generating an acid represented by the following formula (II) upon irradiation with actinic rays or radiation; and a compound capable of generating an acid represented by the formula (III) as defined herein upon irradiation with actinic rays or radiation.

Positive resist composition and pattern-forming method using the same

A radiation sensitive resin composition comprising (A) a fluorine-containing copolymer of hexafluoropropylene, at least one compound selected from the group consisting of unsaturated carboxylic acids and unsaturated carboxylic anhydrides, and an unsaturated compound (B) an acid generating compound which generates an acid upon exposure to radiation; (C) a cross-linkable compound; and (D) an organic solvent. The composition suitable is useful for a negative resist for forming a mask for the production of a circuit such as a semiconductor integrated circuit or a thin film transistor circuit for liquid crystal displays as well as a material for forming a permanent film such as an interlaminar insulating film or a color filter protective film.

Radiation-sensitive resin composition

A positive photosensitive composition comprises a compound capable of generating a specified sulfonic acid upon irradiation with one of an actinic ray and radiation and (B) a resin capable of decomposing under the action of an acid to increase the solubility in an alkali developer.

Positive photosensitive composition

https://cyberleninka.org/article/n/1310744.pdf

Poly(amidoamine), polypropylenimine, and related dendrimers and dendrons possessing different 1 → 2 branching motifs : An overview of the divergent procedures

PURPOSE: To obtain the title composition excellent in radiation sensitivity, mechanical strengths and heat resistance, by mixing a specified amic acid with a specified amine compound and a specified tetracarboxylic acid diester. CONSTITUTION: A tetra- or tri-carboxylic acid (a) is reacted with an amic acid (b) in an amount at least 2mol% excess over component (a) to obtain an amic acid (A) of formula I (wherein R 1 is a trivalent or tetravalent organic group, R 2 is a bivalent organic group, n is 1W2, and m is 2W100). 100pts.wt. component A is mixed with 20W200pts.wt. amine compound (B) having an unsaturated bond dimerizable or polymerizable with a radiation (e.g., N,N- dimethylaminoethyl methacrylate) and 1W50pts.wt. tetracarboxylic acid diester (C) of formula II (wherein R 3 is a tetravalent organic group, and X is a radiation-sensitive group). COPYRIGHT: (C)1989,JPO&Japio

PURPOSE:To obtain the title composition excellent in coating property and storage stability, small in film thinning after curing and useful for a protective film of a surface and an interlaminar insulation film of a semiconductor element, by adding water to a mixture of a specified polyimide precursor with a compound having a radiation-polymerizable unsaturated bond and an amino group (quaternary salt). CONSTITUTION:100pts.wt. polyimide precursor of formula I (wherein R is a trivalent or tetravalent organic group such as a group of any one of formulas II-IX, R is a bivalent organic group, and n is 1 or 2) is mixed with 20-200pts. wt. compound having a radiation-dimerizable or -polymerizable unsaturated bond and an amino group or its quaternary salt group. 1-100pts.wt. water is added to 100pts.wt. this mixture.

Radiation-sensitive composition

In this study, we analyzed cross-linked phenolic resins by using atomistic molecular dynamics simulations. Cross-linked structures consisting of a network of three functional phenols and two functional methylenes with degrees of cross-linking of 0.70, 0.82, and 0.92 were prepared by cross-linking reactions of linear novolac-type phenolic resins in a unit cell under three-dimensional periodic boundary conditions. Uniaxial elongations of the cross-linked structures to a strain of 0.03 were performed at 300 K. At this temperature, all structures were apparently in a glassy state, which was confirmed by the analysis of specific volume as a function of the temperature. The uniaxial elongation did not cause a significant change in the distribution of bonding potential energies (i.e., bond stretching, angle bending, and torsion angle potentials). On the other hand, the change in the potential energies owing to the uniaxial elongation indicated that cross-links suppressed local segmental motions in the cross-linked structure, probably at the region around the linear and terminal phenols, which resulted in an increase in the degree of cross-linking accompanied by a decrease in Poisson's ratio and an increase in Young's modulus.

Atomistic molecular dynamics study of cross-linked phenolic resins

We investigated the relationship between the elastic modulus, G and the reaction probability, p for polymer networks. First, we pointed out that the elastic modulus is expressed by G = {(fp/2 − 1) + O((p − 1)2)} NkBT/V (percolated network law), which does not depend on the local topology of the network structure or the existence of the loops. Here, N is the number of lattice point, V is the system volume, f is the functionality of the cross-link, kB is the Boltzmann constant, and T is the absolute temperature. We also conducted simulations for polymer networks with triangular and diamond lattices, and mechanical testing experiments on tetra-poly(ethylene glycol) (PEG) gel with systematically tuning the reaction probability. Here, the tetra-PEG gel was confirmed to be a potential candidate for ideal polymer networks consisting of unimodal strands free from defects and entanglements. From the results of simulations and experiments, it was revealed, for the first time, that the elastic modulus obeys this law...

Rubber elasticity for incomplete polymer networks.

Equilibrium swelling and phase behavior of liquid crystalline (LC) networks swollen in miscible nematogenic solvents has been investigated by polarizing microscopy as a function of temperature. Four systems, i.e., each of two different LC networks comprising dissimilar mesogens in two different nematic solvents, exhibit essentially the same swelling and phase characteristics. The swelling characteristics strongly correlate with the phases of the LC molecules inside and outside the gel. The two independent nematic-isotropic transition temperatures for the gel (TNIG) and the surrounding pure solvent (TNIS; TNIG>TNIS for all the systems examined) yield three characteristic temperature regions. In the totally isotropic and nematic phases (T>TNIG and T<TNIS, respectively), the degree of equilibrium swelling (Q) is almost independent of T, and the magnitudes of Q in these phases are comparable. Meanwhile, Q strongly depends on T in the region TNIS<T<TNIG where the LC phases inside and outside the gel are differ...

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Toshio Nakao

Papers

Radiation-sensitive resin composition

Radiation-sensitive composition

Atomistic molecular dynamics study of cross-linked phenolic resins

Rubber elasticity for incomplete polymer networks.

Volume transition of nematic gels in nematogenic solvents