JP2889907B2 - Tetramethyl biphenol composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to 3,3 ′, 5,5′-tetramethylbiphenyl-4,
The present invention relates to a 4'-diol (hereinafter referred to as tetramethylbiphenol) composition, and more particularly to a tetramethylbiphenol composition suitable for industrial use as a raw material for a resin or a resin intermediate.

[Prior Art] It is known that tetramethylbiphenol can be produced by oxidative coupling of 2,6-xylenol.

For example, in the methods described in JP-A-53-65834, JP-A-60-152433, and JP-A-63-72638, water is used as a solvent in the presence of a surfactant and an alkaline substance. To
It is disclosed that tetramethylbiphenol can be obtained by oxidative coupling of 2,6-xylenol with oxygen using a copper catalyst.

As a method for isolating tetramethylbiphenol from the reaction product, the reaction product slurry is acidified, cooled and filtered to obtain crude tetramethylbiphenol, which is further washed with an aromatic solvent such as xylene. After filtration and drying, purified tetramethylbiphenol is obtained.

[Problems to be solved by the invention]

However, the tetramethylbiphenol obtained by such a method is mainly composed of fine powder having a particle size of 75 to 105 μm, and there are some aggregates of 180 μm or more.
It is a fine powder containing not more than 80 μm and not less than 50% by weight, and is extremely difficult to handle industrially. For example, when filling dry tetramethyl biphenol into a flexible container, or charging a filled flexible container into a reactor or holder, problems in the working environment and occupational health due to scattering or floating of fine powders may occur. In addition, there are also problems such as the risk of adhesion of the container wall due to generation of static electricity and an explosion accident.

As a method for solving such a problem, a method in which the form of tetramethylbiphenol is made into a flake or prill form, or a method in which the form is dissolved in a solvent and handled, is considered. It is necessary to once melt tetramethylbiphenol before performing the process, but the melting point is extremely high at 220 ° C or higher, which is not only industrially difficult, but also causes the problem of producing heavy substances due to evaporation loss and thermal deterioration. In the latter method, tetramethylbiphenol is liable to be oxidized into tetramethyldiphenoquinone in a dissolved state, and is liable to be degraded. However, there is a problem that the solvent is required.

The present invention solves these problems and provides a tetramethylbiphenol composition that facilitates industrial handling of tetramethylbiphenol.

[Means for solving the problem]

The present invention has been made based on the finding that the above-mentioned purified fine powder of tetramethylbiphenol has a reduced scattering property in a water-containing state.

That is, the present invention relates to 3,3 ', 5,5'-tetramethylbiphenyl-4,4 in which the main component of the particle size is 75 to 105 μm and the component having a particle size of 180 μm or less is contained by 50% by weight or more. '-Diol powder having a water content of 2 to 25% by weight
A 3,3 ', 5,5'-tetramethylbiphenyl-4,4'-diol composition characterized by the following formula:

2 to 25% by weight of water-containing tetramethyl biphenol is not only excellent in the effects of preventing scattering and floating of powder, preventing generation of static electricity and the like, but also simple in its preparation and economical because no solvent or heat energy is used. In addition, the storage stability of tetramethylbiphenol is good.

If the water content is less than 2% by weight, the effect of preventing powder from scattering and floating is small, and if the water content exceeds 25%,
The powder is easily blocked and adheres to the vessel wall, making handling difficult. Therefore, the water content is 2-25
% By weight, preferably 5 to 20% by weight.

As a method for impregnating water with tetramethylbiphenol, a method of solid-liquid separation from tetramethylbiphenol dispersed in water by centrifugation or the like so that the water content is in a range of 2 to 25% by weight, or a method of drying tetramethylbiphenol Spray water while stirring the biphenol to make the water 2 ~
It can be carried out by, for example, a method of impregnating so as to have a concentration of 25% by weight.

When using water-containing tetramethyl biphenol as a raw material for a resin or a resin intermediate, if the presence of water is inconvenient, remove water by azeotropic distillation using a solvent azeotropic with water. Can be.

When tetramethylbiphenol is used as a raw material for an epoxy resin, hydrated tetramethylbiphenol can be used as it is.

〔Example〕

 Hereinafter, embodiments of the present invention will be described.

The water content referred to in the text is 3 degrees at 70 ° C in a vacuum dryer.
It was determined by measuring the loss on drying when the sample was dehydrated by heating for a period of time and became constant weight.

Example 1 An aqueous slurry containing about 30% by weight of tetramethylbiphenol was heated to 70 ° C. and dewatered by a centrifugal separator with stirring to obtain tetramethylbiphenol having a water content of 14%.

Fill the flexible container bag with 300 kg of this hydrous tetramethylbiphenol, store it at room temperature for one month, transfer it from the flexible container bag to the hopper,
Further, the reactor was charged. In this process, scattering, floating, adhesion to the vessel wall and blocking of tetramethylbiphenol were hardly recognized. Also, no deterioration in quality was observed.

Comparative Example 1 An aqueous slurry containing about 30% of tetramethylbiphenol was filtered at room temperature with a Nutsche filter to obtain a water content of 28%.
Was obtained.

The flexible container bag was filled with 300 kg of this hydrated tetramethylbiphenol, stored at room temperature for one month, transferred from the flexible container bag to the hopper, and charged into the reaction vessel. Tetramethylbiphenol adhered to the pipe, and the whole could not be easily charged into the reactor.

Comparative Example 2 About 14% aqueous tetramethylbiphenol obtained in the same manner as in Example 1 was heated at 70 ° C. and 10 ° C. using a conical vacuum dryer.
It was dried at 0 Torr until the water content became 1.2%. When trying to fill this into a flexible container, the powder scattered and floated, and the working environment deteriorated.

〔The invention's effect〕

The present invention relates to fine powder
In a very simple form that contains water by weight, it is possible to effectively prevent the scattering and floating of tetramethylbiphenol powder, which previously hindered the working environment, and without storage problems such as quality deterioration. Thus, the working environment and working efficiency can be improved without any trouble in storage, transportation, preparation and other handling of the powdered tetramethylbiphenol.

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Claims (1)

(57) [Claims] (1) The main component of the particle size is 75 to 105 μm, and the particle size is 1
3,3 ', 5,50% by weight or less contained
3,3 ', 5,5'-tetramethylbiphenyl powder comprising 5'-tetramethylbiphenyl-4,4'-diol, wherein the powder has a water content of 2 to 25% by weight. −4,
4'-diol composition.