DE2005044A1 - Improved Process for Making Oil-Free Alkyd Resins - Google Patents

Description

Patent attorneys

Dr. Dieter l ·. fviorf ^ _pebruary , _197O -

Dr. Hans-A. Bre.us 0-4057

28

o «j, f.-.— · -UöiSir. 28

Ζ '". CELANESE CORPORAiDIOH · · \

522 Fifth Avenue, New York, NY ₉ V.St.A.

Improved Process for Making Oil Free Alkyd Resins

The invention relates to an improved method of manufacture oil-free alkyd resins, the coatings being improved by e flexibility, chemical resistance, adhesion- · ability and significantly higher surface hardness compared to the generally acceptable, customary alkyd resins *

Usual alkyd resins are essentially composed of; oleyl oils, aromatic dibasic acids and an aliphatic monobasic larg-chain unsaturated fatty acid and are used for the production of pilm coatings for use as stoving enamels for equipping industrial plants, for devices, strips and lanyards and Like. Used. The well-known disadvantages of conventional alkyd resins are the poor retention of the glass, hardness to aging or brittleness of the coating, which occur over a period of time, and it is generally assumed that these disadvantages are caused by air oxidation of the unsaturated bonds. long-chain fatty acids of common alkyd resins, which are required to produce a coating with the desired flexibility. Further provide conventional alkyd, the more old 40 ^ zweibaeische aromatic acids, in particular Phthelaäureai ^ rld containing _r lceiiie coatings with zufriedenetellonden Eigensohaiten, including flexibility ^ ,. ohemisone resistance, and the like Häitt .-. · 'In the approach of polyesters on the Basi It is known of phthalic anhydride as the acid component Sf; -J ^ B ^ * fi; lf * Io] Bf;. '.

rV- '■ 009134 /

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tional alcohols such as glycerine, pentaerythritol or trimethylolpropane, regardless of whether these are used individually or in combination, are soft ^: and show no scratchiness. On the other hand, resins of this type containing about 40% phthalic anhydride are very brittle and have no adhesive strength.

There has now been an improved method of making oil-free Alkyd resins, i.e. alkyd resins without the long chain fatty acids, have been found to be superior coatings among other things - Provides in terms of flexibility, chemical resistance and adhesiveness, with phthalic anhydride contents above Ao wt. ~ # Can be used. These are oil-free alkyd resins from an interpolymer of a polyol with 3 pB 4 functional parts Hydroxyl groups, an aliphatic diol with 5 to 7 Carbon atoms and a phthalic anhydride component · built up. The interpolymer so produced is practical free from gel formation.

The process of the invention is carried out by reacting the polyol, aliphatic diol and "; d.eä:; phthalic anhydride in the presence a catalytic amount of a dialkyl tin (IV) oxide carried out under temperature conditions that bring about an esterification of the reaction materials. .

The dialkyl tin (IV) oxide catalysts are also available as dialkyl tin oxide known. These catalysts contain alkyl groups, in which each alkyl radical has 1 to 6 carbon atoms. Typical examples of these catalysts are dimethyl tin (IV) oxide, Diethylan (IV) -O3cyd, dibutyltin (IV) oxide, dihexylsinn (IV) oxide and the like. The preferred catalyst is dibutyl-8in (IV) oxide. The amounts of catalyst are in the range from about 0.05 to about 5% by weight of the total mass, preferably

009834 / 19A7

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from about 0.1 to about 1 wt .- ^. · ■ '-

The temperature conditions for the reaction can to 25O ⁰ C ₁ if necessary, are at about-100th · ■■■ /.- "'■ :" ■■ ■: ■■, ■ - ■. ■ - "," ■.

Usable polyols include, for example Glycerin, "Pentaerythritol and TrimethyIolpropan. Among the aliphatic Moles that can be used include pehtanediol, hexanediol, and - ': he, phtanediol, and particularly preferred is 1,6-hexanediol. As a phthalic anhydride component can for example phthalic acid, isophthalic acid and phthalic anhydride be used.

The amounts of polyols in the interpolymer can be in the range from about 2.5 to 25% by weight, preferably from about 5 to 20% by weight, based on the total interpolymer. The aliphatic diol may be in the amount ranging from about 25 to 45 wt .- ^, preferably from about 30 to 40 wt. ~ Fo _t based on 'the total interpolymers are. Die'Phthalsäureanhydridkom- · pOnentö may range 'of about 45 to 65 parts by weight 5i, preferably about 50 to 60 wt .- ^ ₁ are based on the total interpolymers. It will of course be understood that the total amount of the components does not exceed 100% by weight. Curable compositions can be made using the oil-free alkyd resins of the invention in combination with amine resins to produce excellent elm. and melamine-iormaldehyde condensation products which are known. Particularly preferred amines are the methoxyalkylmelamines with 3 to 6 methoxyalkyl groups, the alkyl radicals having 1 to 6 carbon atoms. The. Amine resins in these curable compositions are in the range of about 5 to 50 weight percent with the remainder being the interpolymer described above.

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009834/1947

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The interpolymers of the invention are particularly suitable for the production of alkyd resins, urethane resins, epoxy resins for the production of laminates, waxes, flame retardants and the like. · ■ ^;

The following examples serve to illustrate the invention without limiting it.

example 1

116 g of pentaerythritol, 452 g of 1,6-hexanediol and 631 g of phthalic anhydride are placed in a reaction vessel. Nitrogen is passed over the reactants to replace air present and to add heat. The esterification reaction takes place at a temperature not above 234 ^° C. for a period of 7 hours. During this period, 76.8 grams of water are removed. After the reaction has ended, the reaction product is cooled and a sufficient amount of a butanol / xylene solvent is added. 50:50 ratio is added _; and an oil-free alkyd resin with 60% solids is obtained, which is practically free of gel formation and has the following properties:

Pesticides ■ 60.1 $ + 15t \

Viscosity ■■ 720 cP V 'acid number «3.2

Colour ". -1 (Gardner)

■ ·· '■ *' Example 2

5η _Λ a reaction vessel are 116 g of pentaerythritol, 452 g of 1,6-hexanediol, 631 g of phthalic anhydride and 6 g of dibutyl- ■. tin oxide (tin (IV) oxide) given. Nitrogen is passed over the reactants to replace the air present and to add heat. The esterification takes place at temperatures not above 239 ^° C. for a period of 5 hours. During this period, 81 g of water are

00983A / 1947

far away. After the reaction has ended, the reaction product is cooled and sufficient amounts of a butanol / xylene solvent (ratio 50:50) are added to obtain an oil-free alkyd resin with 6Q $ solids which is essentially free from formation and has the following propertiesί

solids a 60.4 $ + · 1 # - ■

Viscosity. "A .470 oP acid number = 2.5.. Color = .11 / 2 (Gardner)

The excellent properties of the mimes produced with the oil-free alkyd resins according to Example 1 and hexamethoxymethylmelamine "correspond" to the properties of the mimes obtained with the oil-free alkyd resins according to Example 2 and hexamethoxyraethylmelamine. It is noted, however, that the oil-free alkyd resin according to Example 2 required less time to complete the reaction using dibutyltin (IV) oxide as a catalyst, al8 the oil-free alkyd resin according to Example 1. ..... ■ »'. . ■ '

It should darauf-, noted that the foregoing description is only preferred embodiments of the invention explained E _r and that the skilled person can carry out variations within the framework of the invention, ·

.009034 / 194-7

Claims (1)

c-4657 L -4. Feb 2 $$ 5 OA Patent claims 1.Improved process for the production of oil-free alkyd resins, which can deliver superior coating compositions, thereby . characterized in that an intermediate polymer is produced, da.3 is practically free from gelation, internally a polyol ώ1ΐ. · 3 to 4 functional hydroxyl groups, one aliphatic Egg with 5 to 7 carbon atoms and a phthalic acid. anhydride component in the presence of a catalytic!.! close a dialkyl tin (IV) oxide, in which each alkyl group 1 to 6 carbon atoms can be implemented. 2. The method according to claim 1, characterized in that the interpolymer, the polyol in amounts of about 2.5 to 25 wt .- $, the aliphatic diol in amounts of about 25 to 45 wt .- $, phthalic anhydride in amounts of about 46 to 65 wt .- 5 · and the Dlalkyl-tin (IV) oxide in amounts of 0.05 to about 5 wt .- ^ ', ..., where the weight # is based on the total mass and the total percentages do not exceed 100% by weight - 5 $, 3 · The method according to claim 1, characterized in that the Interpolymers daa polyol in amounts of about 5 to 20 wt .- #, the aliphatic diol in amounts of about 30 to 40 wt .- #, phthalic anhydride in amounts of about 50 to 60 wt .- # and the dialkyl tin (IV) oxide in amounts of about 0.1 to about 1 wt .- #, where the weight percentage refers to the total mass and the total percentage β 100 j6 do not exceed. 4. Process according to Claim 3, characterized in that the aliphatic diol used is ...: 1,6-hexarudiol. 5. The method according to claim.4, "- characterized in that one ■ "*" 009834 / 19A7 ORIGINAL INSPECTED c-4657. : .a & - ν t '. . ■ ' '■■' '' · -, 0ΪΗ ■ · used as eolyol pentaerythritol "" 6. The method according to claim 5, characterized in that the catalyst used is dibutyltin (IV) oxide. ' ;. ', 00 98 3 4 / ■ ORIGINAL INSPECTED