4- 1,8-naphthalic

Formula M.p. Methyl ester M.p. Ethyl ester M.p. Acetyl deriv M.p. Benzoyl deriv M.p 3.5 Dinitro. benzoyl deriv. M.p. Naphthal- ene sulphonyl deriv. M.p. 

WATER-INSOLUBLE NAPHTHALIC ACID IMIDE DYESTUFFS... 

Water-insoluble naphthalic acid imide dyestuffs of the... 

New water-insol. naphthalic acid imide dyestuffs - used to dye blends of polyamide or urethane- and polyester or tri acetate fibres having good light and washing fastness C91-110.342 RICH DE GB LI) ... 

A waler-insol. naphthalic acid imide dyestuff of formula (I) is new ... 

Naphthalic acid (naphthalene-1,8-dicarboxylic acid) [518-05-8] M 216.9, m 270°, PKeu(I) 2.1, pKEst(2) 4.5. Crystd from EtOH or aq EtOH. 

Naphthalic anhydride [81-84-5] M 198.2, m 274°. Extracted with cold aqueous Na2C03 to remove free acid, then crystd from acetic anhydride. 

The copolymers are prepared using a mixture of dimethyl terephthalate and dimethyl naphthalate. Published data indicates a reasonably linear relationship between and copolymer composition on the lines discussed in Section 4.2, e.g. Tg for a 50 50 copolymer is about 100°C which is about mid-way between Tg figures for the two homopolymers. In line with most other copolymers there is no such linearity in the crystalline melting point (T, ). As comonomer levels are introduced drops from the values for both homopolymers and indeed crystallisation only readily occurs where one of the components is dominant, i.e. 80%. Thus commercial copolymers are usually classified into two types ... 

A solution of 66.5 g. (1.01 moles) of 85% potassium hydroxide in 300 ml. of water in an 800-ml. beaker is heated to 60-70 , and 100 g. (0.505 mole) of commercial 1,8-naphthalic anhydride (Note 1) is stirred in. The pH of the resultant deep-brown solution is adjusted to a value of 7 (Note 2) with 6N hydrochloric acid and 3N potassium hydroxide. It is treated with 10 g. of decolorizing carbon and filtered. This operation is repeated. The filtrate is concentrated in a 1.5-1. beaker on a steam bath to about 180 ml. The concentrate is cooled to room temperature, 800 ml. of methanol is added with vigorous stirring by hand, and the mixture is cooled to 0-5°. The precipitated dipotassium naphthalate is separated by filtration, washed with 150 ml. of methanol, and dried in a vacuum oven at 150°/150 mm. The dried cream-colorcd salt weighs 130 135 g. (88 92%). 

Suitable 1,8-naphthalic anhydride, m.p. 274-275°, is obtainable from Coaltar Chemicals Corp., 420 Lexington Ave., New York, N. Y. 

In the early 1990s interest developed in the packaging material polyethylene naphthalate (PEN), a close cousin of PET. PEN has thermal stability 20°C higher than PET. Kodak had samples of the material sifting in its labs from the makers Teijin in Japan, as early as the beginning of the 1970s. Teijin is still the premier producer of PEN film and plastic today, and is involved with DuPont on the film manufacturing side. 

Naphthalic anhydride has been prepared by the hydrolysis of the dinitrile of ,2-naphthaIic acid,1 by the oxidation of suitably substituted hydrocarbons or ketones,2 or by the dehydrogenation of the 3,4-dihydro compound with bromine 3 or with sulfur.4... 

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