HEADING 39.09 - AMINO-RESINS PHENOLIC RESINS AND POLYURETHANES IN PRIMARY FORMS.

48 COMMODITIES

This heading covers :

(1) Amino-resins

These are formed by the condensation of amines or amides with aldehydes (formaldehyde furfuraldehyde etc.). The most important are urea resins (for example urea-formaldehyde) thiourea resins (for example thiourea-formaldehyde) melamine resins (for example melamine-formaldehyde) and aniline resins (for example aniline-formaldehyde).

These resins are used for the manufacture of transparent translucent or brightly coloured articles of plastics and are much used for moulding table and fancy ware and electrical goods. In solutions and dispersions (emulsions and suspensions) (whether or not modified with oils fatty acids alcohols or other synthetic polymers) they are employed as glues and as textile dressings etc.

(See the General Explanatory Note to this Chapter exclusion (b) for the classification of glues.)

Polyamine resins such as poly(ethyleneamines) are not amino-resins and fall in heading 39.11 when complying with the requirements of Note 3 to this Chapter.

(2) Phenolic resins

This group comprises a wide range of resinous materials derived from the condensation of phenol or its homologues (cresol xylenol etc.) or substituted phenols with aldehydes such as formaldehyde acetaldehyde furfuraldehyde etc. The nature of the products varies according to the conditions under which the reaction is conducted and whether it is modified by the introduction of other  substances.

Thus the group includes :

(a) Resins (novolaks) which are permanently fusible and soluble in alcohol or other organic solvents and which are produced under acid conditions.

(b) Thermosetting phenolic resins which are obtained under alkaline conditions. In the processing a continuous range of products is obtained.

Firstly the resols in the form of liquids pastes or solids which are used as varnish bases impregnants etc. Secondly the resitols which are in the form of moulding powders and finally after complete reaction resites which are most often in finished forms such as plates sheets rods tubes or other articles generally classified in headings 39.16 to 39.26.

Certain resins of this kind are ion-exchangers and fall in heading 39.14.

(c) Oil-soluble phenolic resins (soluble in drying oils) prepared from butylphenol amylphenol parahydroxydiphenyl or other substituted phenols.

They are used mainly in the preparation of varnishes.

(d) Products based on the resins referred to at (a) (b) and (c) above modified by the incorporation of rosin or other natural resins synthetic resins (especially alkyd resins) vegetable oils alcohols organic acids or other chemicals which affect their solubility in drying oils. These products are used in the preparation of varnishes and paints as surface-coatings or impregnants.

(3) Polyurethanes

This class includes all polymers produced by the reaction of polyfunctional isocyanates with polyhydroxy compounds such as castor oil butane-1 4 polyether polyols polyester polyols. Polyurethanes exist in various forms of which the most important are the foams elastomers and coatings. They are also used as adhesives moulding compounds and fibres.

For the classification of polymers (including copolymers) chemically modified polymers and polymer blends see the General Explanatory Note to this Chapter.