Sumita Optical Glass, Inc.

Meiji Seika Kaisha, Ltd.

Rakuto Kasei Industrial Co., Ltd.

Masaaki Otsuka

Naruhito Sawanobori

Shinobu Nagahama

Masaaki Yamazaki

Masayuki Komiya

Yoshinori Yamamoto

Toshiaki Kono

Toru Hamaya

Hideaki Takaku

Koichi Tsuchiya

An optical glass suitable for mold forming having a metal composition in wt % in terms of metal oxides calculated from the composition of the following components: PO34&#x2013;50%, LiO 2&#x2013;9%, NaO 7&#x2013;28%, KO 3&#x2013;27%, provided that the total of RO is 17&#x2013;41% (R: Li, Na, K), AlO6.5&#x2013;30%, ZnO 0&#x2013;22%, BaO 0&#x2013;21%, SrO 0&#x2013;18%, CaO 0&#x2013;16%, MgO 0&#x2013;14%, provided that the total of R'O is 0&#x2013;34% (R&#x2032;: Zn, Ba, Sr, Ca, Mg), ZrO0&#x2013;1.5% and F 1.5&#x2013;32% relative to the total weight of the oxides, and exhibits a glass transition temperature (Tg) of 350&#xb0; C. or lower and a specific gravity (Sg) of 3.1 or less and is excellent in chemical durability. The optical glass can be press formed at a low temperature of about 270 to 400&#xb0; C.

Optical glass suitable for mold forming

The present invention provides an optical glass for press molding, in particular, a low softening point glass which contains, in an oxide glass of phosphate type, a durability improving component in addition to glass forming components, and has a weight loss of at most 0.15 weight % in a durability test, and which is represented, in term of elements for making up the glass, by the following chemical composition (mol %):

Optical glass for molding

A glass material is provided which is capable of exhibiting fluorescence in the visible region by ultraviolet ray excitation. This glass material is represented, in term of atoms for making up the glass, by the following chemical composition (mol %):

Oxide fluorescent glass capable of exhibiting visible fluorescence

A method for preventing redeposition of desorbed dyes to pre-dyed fabrics or its garments, which comprises adding colloid at the treatment of pre-dyed fabrics or its garments. A dye antiredeposition agent to be used at the treatment of pre-dyed fabrics or its garments, which contains a colloid in an amount of 0.4 g or more per 500 avicelase units of cellulose. The present invention has rendered possible simple and efficient prevention of redeposition of dyes at the time of the treatment of pre-dyed fabrics or its garments. Especially, when an enzyme is used in the treatment, adverse influenced upon the enzyme is characteristically small.

Method for preventing redeposition of desorbed dyes to pre-dyed fabrics

According to the present invention, there is provided a fluorophosphate fluorescent glass, capable of converting invisible ultraviolet rays into visually observable visible rays with a high efficiency and available for controlling the optical axis of a laser beam such as excimer laser, etc. The feature of this fluorescent glass consists in a fluorophosphate fluorescent glass capable of exhibiting fluorescence in the visible region, having a chemical composition comprising, at least, (I) phosphorus (P), oxygen (O) and fluorine (F), as glass constituting components, and (II) at least one member selected from the group consisting of divalent europium, terbium, samarium and manganese, as a fluorescent agent, the divalent europium being contained as an essential component and at least one of samarium and manganese being contained as an essential component when terbium is contained. In particular, a fluorophosphate fluorescent glass exhibiting a blue fluorescence containing europium as an essential component and a fluorophosphate fluorescent glass exhibiting a white fluorescence containing at least one of samarium and manganese as an essential component are provided.

Fluorophosphate fluorescent glass capable of exhibiting fluorescence in

According to the present invention, there is provided a fluorescent glass of the present invention is capable of converting invisible ultraviolet rays into visually observable visible rays with a high efficiency and available for controlling the optical axis of a laser beam such as excimer laser, etc. The feature of this fluorescent glass consists in a Tb- or Eu-containing fluorophosphate fluorescent glass having a chemical composition comprising, at least, phosphorus (P), oxygen (O) and fluorine (F), and further containing Tb or Eu as a fluorescent agent, and specifically comprising, in terms of atoms for making up the glass (mol %):

Tb-  or Eu-containing fluorophosphate fluorescent glass

A fluorophosphate optical glass having optical constants, i.e. a refractive index of 1.45 to 1.54 and an Abbe number of 75 to 90, preferably 75 to 89.5, useful as a lens for an optical instrument to obtain a good quality image, is provided, which has a chemical composition (% by mole) comprising:

Fluorosphosphate optical glass

A fluorophosphate optical glass having optical constants, i.e. refractive index (nd) of 1.54 to 1.60 and Abbe number (.nu.d) of 68 to 75 and having abnormal partial dispersion represented by a relative partial dispersion of at least 0.537 is provided, which has a chemical composition (% by weight) comprising:

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Saitama, Japan

Masaaki Otsuka