DE2507810A1 - PROCESS FOR MANUFACTURING UNSATATULATED POLYESTER RESINS - Google Patents

Description

VIANOVA KUNSTHARZ AKTIENGESELLSCHAFT, A lOlO Vienna, I., Johannesg. 14th

Process for the production of unsaturated polyester resins

509842/0988

Solutions of ethylenically unsaturated polyester resins in copolymerizable Monomers are widely used as binders for coatings and molding compounds.

Binders of this type are not only characterized by their high level of application properties, such as flexibility, Hardness and hardening speed, resistance to various reagents, etc., but also because of the fact that these Properties can be varied in a simple manner within wide limits. So z. B. the mechanical properties of the cured products can be influenced by a suitable structure of the polyester chain. By suitable coordination of the solubility properties it can be achieved that there are no compatibility problems with the desired monomers or their polymers occur, so that in this respect, too, extensive options for adapting the products to the requirements of practice exist.

Further advantages are that the required raw materials, dicarboxylic acids, Polyols and ethylenically unsaturated monomers, as a rule, are inexpensive and manufactured on a large scale and that the production of the unsaturated polyester, even with very different structures, in the usual universal synthetic resin plants can be carried out.

To the usual hardening process using organic Recently, peroxides have been hardening by means of electron beams came.

The advantages of electron beam curing are known to those skilled in the art and essentially comprise the following points:

1. The curing takes place at room temperature, so that the coating temperature-sensitive materials (e.g. plastic, wood, paper, rubber, foils) is possible. In principle any type of substrate is suitable.

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2. The drying process takes a few seconds, which enables an enormous increase in production.

3. Low space requirements and energy costs, no warm-up times and quick control and switching options.

4. There is no loss of solvent. This causes the problems the risk of fire and air pollution is largely reduced.

5. Electron radiation is far more energetic than UV radiation. The radicals required for polymerization form directly from the irradiated material. There are therefore no initiators and catalysts necessary, whereby again a better stability, which is due to Hara3.

6. In the case of electron beam curing, it is in contrast to UV curing the use of pigments, dyes or fillers is possible.

Unsaturated polyester resins have so far been manufactured according to two principles:

On the one hand, unsaturated components, mostly maleic anhydride or fumaric acid, are partially used in the production of the polyester chain used. The ones used during hardening as connection points Ethylenic double bonds that serve are then distributed in the finished product in a statistical manner over the polyester chain.

In the second type, saturated polyesters are first produced, which have free hydroxyl and carboxyl groups. The double bonds are then by reaction with unsaturated Acid anhydrides or isocyanates or epoxides introduced. As the hydroxyl and carboxyl groups in the saturated polyesters are statistically distributed, also have the double bonds in the unsaturated polyesters produced in this way a statistical distribution.

The demand for unsaturated polyesters that are comparable

509842/0988

wise lower doses of radiation can be cured, led to the development of products with a higher content ethylenic double bonds. It had to be noted, however, that this increases the flexibility of the cured products was significantly worsened. The reason for this is in the fact to look for, that in the production by the usual processes the double bonds in a statistical manner over the Polyester chain are distributed, so that an increase in the content of double bonds necessarily leads to a higher network density in the hardened material and thus leads to a lower flexibility.

The object of the present invention was therefore to provide a process for the production of unsaturated, electron beam curable To develop polyester resins which, despite their high reactivity, have high elasticity.

This object could be achieved according to the present invention be solved by linear, possibly pre-crosslinked, saturated polyester resins, which have more than one hydroxyl group at each end of the chain, with an ethylenically unsaturated one Isocyanate converts.

Zv / ar describes British Patent No. 1,337,876 through Electron beam curable binders in which the components dissolved in the unsaturated, monomeric compounds pass through Conversion of aliphatic, alicyclic or aromatic dicarboxylic acids to the corresponding polyhydroxylated bis-oxazolines and subsequent reaction with unsaturated isocyanates is produced.

However, these products have some serious drawbacks. In comparison to polyester resins, there are dicarboxylic acids only available with low molecular weights. In practice, dietary fatty acids rearrange with molecular weights 600 represents the upper limit.

509842/0988

The properties of these 'components can therefore only be found in one narrow framework can be varied by the differences between aliphatic, alicyclic and aromatic dicarboxylic acids is given. Only Mononiero can dissolve the polyester or mixtures of monomers are used, which are so low Have solubility parameters that they are in the liquid and polymerized State with the strongly non-polar products based on aliphatic, alicyclic and aromatic dicarboxylic acids are verträglicii. As can be seen from the cited patent specification, can convert the dicarboxylic acids to the polyhydroxy-Iated Bis-oxazolines only in the case of the longer-chain representatives, such as B. the dimeric fatty acids, take place in substance. In all other cases must be worked in dilution, so that expensive Procedures for i · Isolation are necessary. Another The disadvantage is that in practice only a limited number of dicarboxylic acids are available as industrial-scale products stand. These disadvantages can be avoided by the inventive Products are avoided.

The invention relates in particular to a method of manufacture electron beam curable unsaturated polyester resins dissolved in polymerizable monomers, which is characterized in that a linear, optionally pre-crosslinked, terminal one prepared in a known manner Saturated polyester bearing oxazoline groups with the structural principle

O CH

- j linear polyester - C

• 2 ^ c - j linear polyester - C 1

HOH ₂ C - C - N , ^ _Ν __ _c _

^CH 2 ^0H CH ₂ OH

or in the pre-crosslinked form

R [OOC - linear polyester - C

- C - CH ₂ OH CH ₂ OH

where R remains after the esterification of the hydroxyl groups

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Benden radical of a polyhydroxyl compound and n is greater than 2, preferably 3, with

10-100 mole percent, preferably 30-90 mole percent, of a free one Ethylenically unsaturated isocyanate precursor bearing isocyanate group from di- or polyisocyanates and polymerizable Monomers that contain at least one isocyanate-reactive

I o hydrogen atoms and the group -C = CC, preferably in the presence of a non-isocyanate-reactive polymerizable monomer at 20-100 ° C, preferably at 50-80 ° C, the mole percent of the isocyanate precursor being based on the hydroxyl groups of the polyester _t and dissolves the unsaturated polyester obtained in one or more polymerizable monomers up to a solids content of 30-95% by weight, preferably 60-90% by weight.

Saturated polyesters with the above-mentioned construction principle can according to the German Offenlegungssnschrift No. 2 249 378 manufactured are, if one linear polyesters from diols and dicarboxylic acids, which exclusively carry terminal caroxyl groups, with amino alcohols, preferably tris (hydroxymethyl) aminomethane implements. The polyesters can optionally be subjected to partial esterification before the reaction with the amino alcohol are precrosslinked with polyols with more than two hydroxyl groups.

As unsaturated isocyanate precursors, products of the reaction of di- or polyisocyanates with ethylenically unsaturated ones are used Monomers which contain at least one isocyanate-reactive Contain hydrogen atom and the grouping -C = C- C-. The proportions of the two reactants are chosen so that the isocyanate precursor has a free isocyanate group contains.

As diisocyanates for the preparation of the precursor are, for. B.

suitable:

2,4- or 2,6-tolylene diisocyanate, isopurone diisocyanate, cyclohexane-1,4-di isocyanate, trimethyl-hexamethy 1-en-1,6-diisocyanate,

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Hexamethylene 1,6-diisocyanate, tetramethylene diisocyanate.

Hydroxy-alkyl esters of acrylic or methacrylic acid are preferably used as monomers for reaction with the diisocyanates, ζ. B. Hydroxyäthylacry] at, Hydroxyäthylinethacrylat, 2-Hydroxypropylacrylat, 2-IIydroxypropy. imethyl acrylate, 4-hydroxybutyl methacrylate / tripropylene glycol monomethacrylate c. V / ei ters carboxyl- containing α, β-unsaturated compounds can be reacted with the diisocyanates with elimination of carbon dioxide, e.g. B. acrylic or methacrylic acid, maleic acid half-esters from maleic anhydride and monoalcohols with 1 to 8 carbon atoms.

The representation of the unsaturated isocyanate-containing Vorpi-oduktes takes place in the following way;

In a flask, the diisocyanate is presented, and an equivalent amount of the isocyanate-reactive monomers are added dropwise with stirring and Feuchtαgkeitsausschluß that the reaction temperature at 30 - 35 ^C C remains. The mixture is then slowly to 60 - 70 ⁰ C heated and stirred for about one hour at diesel · temperature. The products obtained are liquid or crystalline substances, depending on the starting compounds used. These are dissolved in polymerizable solvents that do not carry reactive hydrogen atoms, e.g. B. methyl, ethyl, propyl, butyl (meth) acrylate, styrene or substituted styrenes. However, it is easily possible to mix the liquid or crystalline precursors as such with the respective resin solutions, since they are easily soluble in the monomeric resin solvents.

The polyester resins are preferably used as a solution in polymerizable Monomers used for the reaction with the ethylenically unsaturated, isocyanate-containing precursors. as polymerizable solvents can be used in this phase, all monOiiieren compounds that are not isocyanate-reactive Contain hydrogen, e.g. B. alkyl or acrylic esters of (meth) acrylic acid or styrene or substituted styrenes.

509842/0988

These polymerizable monomers, which are also quantitatively crosslinked by the irradiation, are used in amounts of 5-70 % by weight, preferably 10-10% by weight. The reaction of the unsaturated precursor isocyanatnältigen with the saturated polyesters are bai 20 - 1OO ^C C, preferably at 50 -80 ^c C the reaction is at 50 -. 80 terminates ^"J C after 1-5 hours and is kontrolliei't by Isocyanatbestinuumgen In The reaction time is correspondingly lengthened at a lower temperature.

The amount of isocyanate-containing precursor depends on the molecular weight of the polyester used and depending on the desired Properties of the coating vary widely It is 10-100 mol%, preferably 30-90 mol%, based on on the existing isocyanate-reactive hydrogen atoms of the used Base resin.

The unsaturated polyesters produced according to the invention are then with polymerizable monomers on a solid body diluted by 30-95% by weight, preferably 60-90% by weight. as In addition to the abovementioned non-isocyanate-reactive compounds, monomers can now also brew other compounds which can be brewed for this purpose Monomers are used.

The coating compositions according to the invention can be used alone or can be used together with pigments, fillers, dyes. Metal, glass, ceramics can also be used as substrates heat-sensitive materials such as B. plastic, wood, rubber or paper can be used.

The necessary for the curing of the coatings according to the invention High-energy radiation preferably originates from accelerated electrons with at least 100 kV, preferably 300-500 kV. The irradiation can take place under an air atmosphere, but preferably under an inert gas atmosphere.

The following examples illustrate the invention without restricting it.

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Resin No. Dimethyl- Neopentyl- Triethylen- Adipdn- Tris- M Hydroxyl-

terephthalate glycol glycolic acid (hydroxymethyl) - number

aminomethane

1 180 300

2 180 270

O 3 300

^ 4 388 500

5,516,666

317 242 350 264 ω
I. 365 251 8 10 267 438 242 850 264 531 238 1140 196 588 118 3400 66

Manufacture of linear polyester resins

The resins were manufactured in accordance with German Offenlegungsschrift No. 2,249,378 by transesterification of dimethyl terephthalate with the glycol, esterification with adipic acid up to a constant acid number and subsequent reaction with 1Yis- (hydroxymethyl) -amJ η exethane. the Polyester resins were dissolved in various monomers, the following resin solutions K) resulted in: Z?

75% in methyl methacrylate (referred to as "resin solution" of the corresponding resin number)

75% in ethyl acrylate (referred to as "resin solution a" of the corresponding Harsnunuaor) 75% in n-butyl acrylate (referred to from "resin solution b" of eutrproci.er.den resin number

Manufacture of unsaturated isocyanate-containing precursors

222 g (1 mol) Isopiiorondiisocyanat were initially heated to 35 ⁰ C and with stirring and exclusion of moisture while einor hour, 1 mole of the respective isocyanate were added dropwise monomers. The batch was then slowly warmed to 70 ° C. and gorülu-t at this temperature for one hour.

A-. 130 g of hydroxyethyl methacrylate

B: 116 g of hydroxyethyl acrylate

C: 130 [r hydroxypropyl acrylate

D: 72 g of acrylic acid

E: 172 g of maleic acid monobutyl ester

In addition, 174 g (1 mol) of tolylene diisocyanate were reacted with under similar reaction conditions

F: 130 g of hydroxyethyl methacrylate G: 130 g of hydroxypropyl acrylate

The reaction mixture contains in each case 1 mol of free isocyanate groups.

Execution examples Example 1 :

143 g of resin solution 1 were admixed with 85 g of a 75% strength methyl methacrylate solution of precursor A and the mixture was stirred at 70 ° C. for 4 hours. The reaction product obtained has a solids content of 75 % in methyl methacrylate. (Coating compound 1)

Example 1 a:

Analogous to Example 1, with the difference that the resin solution 1a was used (coating composition la)

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Example 1b:

Analogous to Example 1, with the difference that resin solution 1b was used (coating composition 1b).

Example 2:

143 g of resin solution 1 were mixed with 80 g of a 75% strength methyl methacrylate solution of the precursor B reacted and stirred for 4 hours at 70 ° C. The reaction product was mixed with 23 g of styrene well thinned, so that a 65% solution resulted (coating mass 2).

Example 3:

143 g of resin solution 2 were mixed with 107 g of a 75% strength methyl methacrylate solution of the precursor A are added, and the mixture is stirred at 70 ° C. for 4 hours. The reaction product has a solid body of 75% in methyl methacrylate (coating composition 3).

Example 3 a:

Analogous to Example 3, with the difference that the resin solution 2 a was used (coating composition 3 a).

Example 3 b:

Analogous to Example 3, with the difference that the resin solution 2 b was used (coating composition 3 b).

Example 4:

143 g of resin solution 2 were mixed with 107 g of a 75% strength methyl methacrylate solution of the precursor C reacted and stirred at 70 ° C for 4 hours. The reaction product obtained was with 44 g of a mixture of equal parts of styrene and hydroxyethyl methacrylate further diluted so that a 60% solution resulted (coating composition 4).

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Example 5:

143 g of ¹ resin solution 3 were reacted with 107 g of a 75% strength methyl methacrylate solution of precursor A and the mixture was stirred at 70 ° C. for 4 hours. The reaction product has a solids content of 75 % in methyl methacrylate (coating compound 5).

Example 5 a:

Analogous to Example 5, with the difference that resin solution 3 a was used (coating compound 5 a).

Example 5 b:

Analogous to Example 5, with the difference that the resin solution 3 b was used (coating mass 5 t).

Example 6:

143 g of resin solution 3 were mixed with 67 g of a 75% strength methyl methacrylate solution of the precursor D reacted and stirred at 7O ° C for 4 hours. A reaction product with a results Solids content of 75% in methyl methacrylate (coating compound 6).

Example 7:

143 g of resin solution 3 were reacted with 82 g of a 75% strength methyl methacrylate solution of precursor F and the mixture was stirred ^{at 70 ° C. for 2 hours.} The reaction product has a solids content of 75% in methyl methacrylate (coating compound 7).

Example 8 ·.

143 g of resin solution 3 were reacted with 82 g of a 75% igon methyl methacrylate solution of precursor G and the mixture was stirred at 70 ° C. for 2 hours. The reaction product obtained was further diluted with 23 hydroxyethyl acrylate, so that a 65% strength

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Solution resulted (coating composition 8). Example 9 :

I3 g of Karzlösung 4 were reacted with 80 g of precursor A, dissolved in 27 g of methyl methacrylate _T , and ^{the mixture was stirred at 70 °} C. for 4 hours. The reaction product has a solids content of 75% in methyl methacrylate (coating compound 9).

Example 9 a:

Analogous to Example 9, with the difference that the resin solution 4 a was used (coating compound 9 a).

Example 9 b:

Analogous to Example 9, with the difference that the resin solution 'f b was used (coating compound 9 b).

Example 10:

143 g of the resin solution 5 was mixed with 50 g of a 75% Metnylmethacrylatlösung of the precursor A converted and stirred for 4 hours at 70 ⁰ C. The reaction product obtained has a solids content of 75 % in methyl methacrylate (coating composition 10).

Example 10 a :

Analogous to Example 10, with the difference that resin solution 5 a was used (coating material 10 a).

Example 10 b:

Analogous to Example 10, with the difference that resin solution 5b was used (coating composition 10b).

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Example 11:

143 g of resin solution 2 were mixed with 120 g of a 75% strength methyl methacrylate solution of the precursor E reacted and stirred at 7O ° C for 4 hours. The reaction product has a solids content of 75% in methyl methacrylate (coating composition 11).

Conferences are required

The coating compositions produced according to the examples given above were on degreased aluminum plates in a layer thickness of 60 μm applied and in a nitrogen atmosphere under the electron beam guided.

The accelerator voltage was 500,000 V and the current intensity 18 i, iA. The samples were irradiated continuously twice and at different doses. The films of the above coating compositions cure at 3-5 Mrad and are scratch-resistant, acetone-resistant and particularly elastic «

The results of testing the coatings obtained, at a total irradiation dose of 4 Mrad, are shown below Table summarized.

Explanations to the table

Pendulum hardness
Acetone test

Erichsen depression

according to König DIN 53 157

Exposure to acetone in seconds until the film swells, with 180 seconds as upper limit

DIN 53 156 (60 μ layer thickness)

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Tabel

'Coating compound

} Pendulum hardness

Acetone test

Erichsentiefung

a
b
2
3

a
b
4th
5

a
b
6th
7th

130 s 125 s 105 s 130 s 180 s 165 s 130 s 160 s 160 s 150 s 115 s 150 s 140 s

> 180 s

150 s

154 s

> 180 s

> 180 s

> 180 s

> 180 s

170 s

> 180 s

> 180 s

> 180 s

> 180 s

> 18O s

6.5 mm 6.3 'mm 7.3 ram 6, .p mm 3.5mm 3, 1mm 5.1mm

3.1 mm

6.2 mm 6.0 mm

7.5 mm

5.6 mm

6.8 mm

8th 125 S. ISO S. 7.4 mm 9 165 S. > 180 s 5.1 mm 9 a 150 S. ^ 180 S. 5.0 mm 9 b 125 S. > 18C S. 6.3 mm • 10 100 S. > 180 S. 8.1 mm 10 a 95 S. > 180 G 7.9 mm 10 b 90 S. > 180 S. 8.3 mm 11 135 S. 130 S. 5.7 mm

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Claims (2)

Process for the preparation of unsaturated polyesters which are in particular electron beam curable and dissolved in polymerizable monomers, characterized in that a linear, optionally precrosslinked, terminal oxazoline group-bearing polyester, prepared in a known manner, is constructed using the principle of construction HC - O v ^, - - ο - CH ₂ I ^ lin ^ea ^ er polyester - C i HOH ₀ C -CN ^ ^ N-C-CH _n OH ² II ² CH ₂ OII CH ₂ OH or in the pre-crosslinked form R / 0OC - linear polyester - C C - CH ₀ OH ι ² CH ₂ OH where R is one remaining after the esterification of the hydroxyl groups Represents a residue of a polyhydroxyl compound and η is greater than 2, preferably 3, with 10 - 100 Mo. 1%, preferably 30 - 90 mol%, of an ethylenically unsaturated isocyanate bearing a free isocyanate group before a product made from di- or polyisocyanates and polymerizable monomers containing at least one isocyanate-reactive hydrogen atom and the -C = CC 'group contain, preferably in the presence of a nichtisocyanatreaktiven polymerizable monomers at 20 - 1OO ° C, preferably at 50 80 ° C, where the molar percentages of Isocyanatvorproduktes are based on the hydroxyl groups of the polyester, and the obtained unsaturated polyester with one or more polymerizable monomers up to a solids content 30-95 wt .-%, preferably 60-90 wt .-% dissolved. ^; reacted 9842/0988 2. The method according to claim 1, characterized in that the amino alcohol for introducing the oxazoline group into the unsaturated polyester preferably tris (hydroxymethyl) aminoiFietnan is used. 509842/0988