DE2559857C2 - Cross-linkable thermosetting copolymer and process for making the same - Google Patents

Description

R ₁ -CO ₂ -CH = CH-CO ₂ -R ₂ in which:

10

Rt (a) is an alkyl radical with 2 to 6 carbon atoms and one ω-hydroxyl group;

(b) a 2,3-dihydroxypropyl group or

(c) a group of the general formula:

—K

OH

20th

wherein

x = 2 or 3 and

m - is a numerical value from 1 to 800;

R _{2 is} a linear or branched-chain alkyl radical having 4 to 12 carbon atoms;

3.6 to 34.8% by weight of butyl acrylate or 2-ethyl-hexyl acrylate and

the remainder styrene. Vinyl acetate, acrylic acid or methyl methacrylate in solution or emulsion in Presence of a catalyst producing free radicals at an elevated temperature of up to 97 ° C.

2.Verfahren for the preparation of a copolymer according to claim 1, characterized in that one delivering free radicals in a manner known per se in solution or emulsion in the presence of a free radical Catalyst polymerizes at elevated temperature up to 97 ° C:

(a) 12.8 to 25% by weight of a diester of the general formula:

R ₁ -CO ₂ -CH = CH-CO ₂ -R ₂ in which:

CH ₁ ) J- OH

The invention relates to a crosslinkable, thermosetting Copolymer and a process for its preparation.

It is generally known. Maleic anhydride, maleic acid, fumaric acid and itaconic acid in the technical Scale for the synthesis of (a) unsaturated polyesters and (b) monoesters and diesters of to use monobasic fatty alcohols.

The type (a) unsaturated polyesters can be synthesized to be terminal Have hydroxyl groups. Leave unsaturated polyesters with such terminal hydroxyl groups polymerize with acrylic and vinyl monomers and furthermore with amino resins under the influence of thermal cross-networks. As a result, thermosetting compositions can be produced from such polyesters will. On the other hand, polyesters of type (a) can be based on their unsaturation, i.e. due to the presence of a large number of double bonds per molecule, polymerize, with the Copolymerization with other monomers, e.g. B. acrylic esters and vinyl acetate to a rapid cross-linking and gelation leads.

A copolymerization of polymeric iridescent unsaturated Polyesters of the type described with other unsaturated monomers, e.g. B. acrylic acid and methacrylic acid esters, as well as vinyl acetate, therefore obviously do not lead to industrially usable ones Solution or emulsion copolymers.

Monoesters and diesters of type (b) are used as comonomers for the preparation of solution and Emulsion Copolymers Used However, they cannot be used to add hydroxyl groups to introduce the copolymers, d. H. to make the copolymers crosslinkable.

The parent application DE 25 52 634 describes the synthesis of monounsaturated monounsaturated groups containing hydroxyl groups Maleic and fumaric acid diesters are described, with which the disadvantages outlined let overcome. These diesters correspond to the general formula I:

R ₁ -CO ₂ -CH = CH-CO ₂ -R ₂
where mean:

(I)

45

Ri (a) is an alkyl radical with 2 to 6 carbon atoms and an ω-hydroxyl group; a 2,3-dihydroxypropyl group or a group of the general formula:

(a) an alkyl radical with 2 to 6 carbon atoms and an ω-hydroxyl group;

(b) a 2,3-dihydroxypropyl group or

(c) a group of the general formula II

(Π)

- K CH ₂ VO} ^ - {f CU ₁ ) J- OH

55

wherein

π = 2 or 3,

χ = 2 or 3 and

m = a number from 1 to 800;

R _{2 is} a linear or branched-chain alkyl radical having 4 to 12 carbon atoms;

(b) 3.6 to 34.8% by weight of butyl acrylate or 2'ethyl hexylacfylät And

(c) the remainder is styrene, vinyl acetate, acrylic acid or methyl methacrylate.

η = 2 or 3

χ = 2 or 3 and

m = a number from 1 to 800;
R _{2 is} a linear or branched-chain alkyl radical with 4 to 12 carbon atoms.

The unsaturated diesters containing a hydroxyl group are prepared by adding polyols of the formula R (OH, an alcohol of the formula R ₂ OH and maleic or fumaric acid or an anhydride of the acid in the presence of toluene sulfonic acid as a catalyst in a molar ratio of polyol to alcohol to acid or anhydride of 1: 1.1: 1 reacts with one another.

Preferably in the preparation of the compounds excess alcohol removed from the reaction product after the esterification is carried out in advantageously by distillation.

It has surprisingly been found that the unsaturated diesters described are also found below monomers described in more detail to form solution and emulsion copolymers with particularly advantageous physical properties, for example low viscosity and (reshaping properties (»polymerize permit. These copolymers can be crosslinked with amino resins, for example to thermosetting protective coatings.

The invention relates to a crosslinkable, thermosetting copolymer and a method for its manufacture according to the claims.

The diesters of the general given values used for the preparation of a copolymer according to the invention Formula I are not copolymerizable with those known from DE-OS 14 68 704 and 15 68 883 Monomeu ί confusingly, for the production of which epoxy compounds are used

The preparation of the general diesters required for the preparation of a copolymer according to the invention Formula I is described in more detail in the parent patent.

The diesters can be prepared, for example, with the alkyl acrylates and methyl methacrylate specified in the claims. Styrene and vinyl acetate in propanol and 2-ButoxyäthanoI in the presence of z. B. butyl peroctoate or copolymerize benzoyl peroxide at temperatures from 92 to 97 ° C. The copolymerization products obtained contain 70 to 75% polymer with viscosities of 9,000 to 20,000 cps in the presence of Amino resins are crosslinkable and thermosetting. The monomers described are also included Vinyl acetate, styrene, the specified alkyl acrylates and methyl methacrylate in the aqueous phase with a Content of a surface-active compound is copolymerizable at 60 to 75 ° C. The resulting Products contain 44 to 55% polymer with viscosities from 500 to 2000 cps. These emulsion copolymers too are crosslinkable and thermosetting in the presence of amino acids.

The parts and percentages given in the examples relate to parts by weight or percentages by weight.

I. Preparation of the copolymerizable diesters

A) A cylindrical round bottom reactor equipped with a column and a condenser for the condensation of glycol, a fatty alcohol water ser separator. The stirrer and thermometer were loaded with the following components:

Maleic Anhydride 588 grams 6.0 moles

Isobutanol 590 grams 6.6 moles

Ethylene glycol 372 g 6.0 mol

p-toluenesulfonic acid 3 g

Water 5 g

The reaction components were heated to a temperature of 105 ^{8 C.} As a result of the onset of a strongly exothermic reaction, the reaction temperature rose to 120 ° C within 30 minutes. As soon as the exothermic reaction started, the temperature was increased to 135 to 140 ^° C. Most of the esterification took place at 140 ^° C. During this period, 75 g of water were collected. Then, the temperature was raised to 165 to 17O ⁰ C. During this period another 2 | g of water collected. Then 45 g of isobutanol were distilled off. During this final period the acid number dropped to 8.

The analysis of the product obtained showed:

Acid number 8th Hydroxyl number 230 viscosity 120 cps 2-hydroxyethyl isobutyl ester content 82% other esters 15% free isobutanol 3%

B) A cylindrical reactor, as described under A), was charged with the following components:

Maleic anhydride
n-butanol

Ethylene glycol

p-toluenesulfonic acid

water

588 grams of 6.0 Mo'e
590 grams 6.6 moles
372 grams of 6.0 moles

3g

5g

The reaction components were heated to 105 ° C. As a result of the onset of a strongly exothermic reaction, the reaction temperature ^{rose to 12P 1 C within 30 minutes.} Once the exothermic reaction had occurred, the temperature was 135 to 140 ⁰ C heated Most of the esterification was carried out at 14O ⁰ C. During this period, 75 g of water were collected. The temperature was then increased to 165 to 170 ⁰ C. During this time an additional 21 grams of water was collected. Then 45 g of n-butanol were distilled off. During this final period the acid number dropped to 8.

The analysis of the reaction product obtained led to the following results:

Acid number 8

Hydroxyl number 230

Viscosity 120 cps

2-hydroxyethyl isobutyl ester content 82%

other esters 15%
free n-butanol 3%

C) In a device as described under A), the following were carried out in a further experiment Components implemented with each other:

Maleic anhydride 490 g 5.0 moles Octanol (2-ethylhexanol ) 715g 5.5 moles Ethylene glycol 310g 5.0 moles p-toluenesulfonic acid 3g water 5g trapped Esterification water 85 g distilled off 2-ethylhexanol 57 g Analysis: Acid number 10 Hydroxyl number 185 viscosity 120 cps 2-HydroxyethyIoctyIestergehall 85% other esters 10% free octanol 5%

D) In a device as described under A)
were implemented together;

Maleic anhydride 588 grams 6.0 moles

1,2-propylene glycol 456 g 6.0 mol

Isobutano! 490 grams 6.6 moles

p-toluenesulfonic acid 3 g

Water 5 g

trapped

Esterification water 96 g io

distilled off

Isobutanol 75 g

Analysis:

Acid number 10 15

Hydroxyl number 180

Viscosity 110 cps

{2-hydroxy) propylisobutyl-

ester content 81%

other esters 16% 20

Isobutanol 3%

Maleic anhydride 98 g Isobutanol 82 g Polypropylene oxydiol 1000 g p-toluene sulfonic acid 2g water 5g trapped Esterification water 20 g distilled off Isobutanol 10g

t.OMol 1.1 mol 1.0 mol

E) In a device as under A; described
were implemented together:

Analysis:

Acid number 12

Hydroxyl number 64

Viscosity 900 cps hydroxy (polypropyleneoxy) isobutyl

ester content 72%

other esters 20%

Polypropylene oxydiol 5%

free isobutanol 3%

H) In a device as described in A), were implemented together:

25th

Maleic anhydride 588 g 6.0 moles ; Isobutanol 490 g 6.6 moles Diethylene glycol 636 g 6.0 moles p-toluenesulfonic acid 3g water 5g trapped Esterification water 94 g distilled off Isobutanol 73 g Analysis: Acid number 12th Hydroxyl number 167 viscosity 160 cps 2- (2-hydroxyethoxy) ethyIiso- butyl ester content 80% other esters 16% free isobutanol 4%

Fumaric acid 696 g 6.0 moles Isobutanol 490 g 6.6 moles Ethylene glycol 372 g 6.0 moles p-toluenesulfonic acid 3g water 5g

30th

35

40 The esterification reaction began at a temperature of about 130 ⁰ C.

Collected esterification

water 200 g distilled isobutanol 70 g Analysis: Acid number 11th Hydroxyl number 190 viscosity 130 cps 2-hydroxyethyl isobutyl ester salary 84% other esters 12% free isobutanol 4%

F) In a device as described under A) 45, the following were implemented with one another:

I) In a device as described under A), the following were implemented with one another:

Maleic anhydride 588 g 6.0 moles Isobutanol 490 g 6.6 moles Glycerin 552 g 6.0 moles p-toluenesulfonic acid 3g water 5g trapped Esterification water 90 g distillieites Isobutanol 70 g Analysis: Acid number 10 Hydroxyl number 230 viscosity 600 cps Di (hydroxypropyl) isobutyl ester content 70% other esters 27% free isobutanol 3%

Itaconic acid 650 g 5.0 moles Isobutanol 407 g 5.5 moles Ethylene glycol 310g 5.0 moles p-toluenesulfonic acid 3g water 5g Toluene hydroquinone \ 5g 5% in isobutanol I.

50

55 The esterification reaction proceeded more slowly than in the case of the use of maleic anhydride.

Collected esterification water 170 g isoDUtanol 35 g

The reaction product tended to homopolymerize when exposed to sunlight.

65

G) In a device as described under A),
were implemented together:

Analysis:

Acid number
Hydroxyl number

15 180

viscosity

Hydroxytriyl isobutyl ester content of other esters
free isobutanol

200 cps 80% 16% 4%

II. Preparation of the copolymers

The following examples illustrate solution copolymerization of the starting compounds prepared under A) to I) with acrylic, methacrylic and styrene monomers.

Example I.

A cylindrical reactor equipped with a reflux condenser, stirrer, thermometer, two addition vessels and a heating mantle was charged with 825 g of propanol. The temperature was brought to 90 ° C, whereupon a monomer mixture and a catalyst solution in the reactor over a period of 5 hours the following composition were given:

15th

20th

Monomer mixture:
Methyl methacrylate
Acrylic acid
Butyl acrylate
Connection according to A

Catalyst solution:
Propanol
t-butyl peroctoate

1000 g 300 g 800 g 700 g

90g 13g

25th

30th

Liquid viscosity = 13,000 cps polymer content = 70%

40

It was found that the starting compound A was completely copolymerized.

Thermosetting compound:

Polymer according to Example 1 100 g of water-reducible amino resin

(60%) 10 g

Dimethylethanolamine 3 g

Water 30 g

45

50

A 0.0762 mm thick film of the resulting reaction product was kept at 176.7 ° C. for 5 minutes heated the film had the following properties:

Pencil hardness

NAK extractable

Components

= 2H

= 12% on a solids basis.

set to the hardness of a graphite pencil. Used became a range of standard pencils ranging in hardness from 4B to 4H.

About 6.35 mm of the pencil lead was exposed using fine sandpaper (400 carbides). The for The test pencil used was then in a normal writing position at an angle of 45 ° over the too testing film. The pressure applied was just before the pressure that caused the lead to break. Marks or scratches that were visible at an oblique angle under high exposure, indicated the pencil was harder than the film. The hardness was expressed in degrees of the nearest softer pencil.

The degrees of hardness with increasing hardness are:
4B, 3B, 2B, HB.FH2H, 3H, 4H.

B. MÄK extractable components.

The solubility of a polyvinyl acetate acrylic polymer or acrylic polymers in methyl ethyl ketone decreases as does the degree of crosslinking of these polymers increases. As a result, the extractability of a polymer in methyl ethyl ketone can be used to to determine the degree of cross-linking.

A 0.076 mm thick film of the polymer to be examined is applied from a suspension or solution deposited an aluminum foil. 3 to 5 g of the film are then extracted for 24 hours in a Sohxlet extraction device with methyl ethyl ketone.

The insoluble part is then dried and weighed. As a result, those with methyl ethyl ketone extractable constituents or the insoluble constituents determined in% by weight.

The copolymerization brought about by free radicals took place at 96 ° C. under reflux of propanol. That produced reaction product had the following properties:

Examples 2 to 9

Example 2: as in Example 1, but using the compound prepared according to B.

Example 3: as in Example 1, but using the compound prepared according to C.

Example 4: As Example 1, but using the compound prepared according to D.

Example 5: As Example 1, but using the compound prepared according to E.

Example 6: As Example 1, but using the compound prepared according to F.

Example 7: As Example 1, but using the compound prepared according to G.

Example 8: As Example 1, but using the compound prepared according to H.

Example 9: As Example 1, but using the compound prepared according to I.

The solution polymers prepared according to Examples 2 to 9 had the following properties:

Viscosity range of
liquids
Polymer content

= 9,000 to 18,000 cps = 67 to 72%

Test methods:

A. Pencil hardness

In this test, the hardness of a film produced in the manner described was related to properties of films
made of thermosetting materials (example 1)
Pencil hardness = H to 3H

Mj \ R.-extranated
Components

= 8 to 15%
Solid basis

Table I.

Solution copolymers of Examples 2 to 9

Vinyl acetate 655 g

Connection according to A 100g

2-ethylhexyl acrylate 28 g

Monomer mixture

Exit game
vefbin no.
manure

viscosity
cps

Polymer lead content pen% hardness

MÄK-extra components that can be added here

The following was mixed into the vessel from which the catalyst was added:

B.
C.
D.
E.
F.
G
H

2
3
4th
5
6th
7th

15,000
9,000

17,000
10,000

18,000
10,000
13,000

72
67
67
67
67
68
70

2H H

2H H

3H H

2H

ok

15 11 14 8 14 12

Ammonium persulfate 3

Ammonia (26%) 2.5

Water 27.5

I catalyst I solution

In the container for
were entered:

the addition of the activator

The examples show that the solution copolymers prepared according to the invention are thermosetting Have properties.

Example 10

The apparatus and reaction conditions corresponded to those of Example 1. The monomer mixture was made from the following ingredients. The other components have not been changed:

Styrene 1000 g

Butyl acrylate 800 g

Acrylic acid 300 g

Starting compound according to A 700 g

Activator:

NaHSOjCH ₂ CUH ₂ O 1 1 activator

Water 32 J solution

The aqueous phase was heated to 72 ⁰ C, whereupon 72 g of ivionomerengemisches were added. Therein 1 g of ammonium persulfate was added, whereby the emulsion polymerization was initiated. The reaction temperature rose to 77.degree. C. as a result of the exothermic reaction that began. The monomer mixture, the catalyst solution and the activator solution were added to the reactor over a period of 6 hours. The emulsion polymer obtained had the following properties:

Analysis:

viscosity
Polymer content

Polymer content
viscosity
free monomers
Particle size

Movie

= 17,000 cps = 68%

= 55

= 1000 cps
= 0.4%
= 0.2 to

0.4 microns
= constant,

clear

Thermosetting compound:

Properties one of a
thermosetting mass produced film:

Pencil hardness = 3H

MÄK extractable

Components = 13%

This copolymer was also thermosetting.

The following examples illustrate "emulsion copolymerization of compounds prepared according to A to I with acrylic, methacrylic, styrene and vinyl acetate monomers.

Example 11

A cylindrical reactor was used with three addition containers (for the monomers, the catalyst and an activator), a condenser, a stirrer and a thermometer, was charged with the following components:

Emulsion polymer: Example 10
water reducible UF resin

100 g
10g

A 0.0762 mm thick film cast from the indicated mixture was left for 5 minutes heated to 176.7 ° C. The following properties were found:

Pencil hardness = H

MÄK extractable

Components = 15%

water 54Ug aqueous non-ionic phase surface-active links 34 g anionic surface-active links 26 g Protective colloid 8g

From these results it can be seen that the emulsion polymer of Example 11 in the presence of Amino resins is crosslinkable

Examples 12-19

There were further tests with the device described in the example and in compliance with the j specified reaction conditions carried out with | with the exception that instead of the connection, j as described under A, connections used! obtained according to B, C, D, E, F, G, H and I | became.

The following was mixed into the vessel from which the monomers were added to the reaction vessel:

Example 12:

The compound according to B was used

Example 13:

The compound according to C was used

12th

Example 14: polymer content

The compound according to D was used. viscosity

Example 15:

The compound according to E was used. Particle size

Example 16: 5

The compound according to F was used. Movie

Example 17:

The tie according to G was used.

Example 18:

The compound according to H was used. ok

Example 19:

The compound according to I was used.

In Examples 12-19, emulsion polymers were made manufactured. The emulsion polymers had the following properties:

= 54 to = 800 to

1500 cps = 0.2 to

0.5 micron = clear,

constant

Cross-connectivity:

The thermosetting compositions according to Examples 12 bis provided films with the following properties:

Pencil hardness MÄK extractable components

= Hto2H = 12 to 17%.

Table II

Emulsion copolymers of Examples 12-19

Starting Example Viscosity Particle Size Film Compound No. cps (microns)

Pencil-MÄK-extra hardness herebare

Components

B. 12th 1200 20th 0.3-0.4 C. 13th 1500 0.2-0.4 D. 14th 1500 0.3-0.5 E. 15th 1500 0.3-0.5 F. 16 1500 0.3-0.5 G 17th 1500 0.3-0.5 H 18th 1000 0.2-0.4 I. 19th 1500 0.2-0.4 example

The compound produced as described under A, 40 was copolymerized with acrylic monomers using those described in Example 11 Device and under the conditions specified there, with the following changes:

The monomer mixture had the following composition:

Methyl methacrylate
Butyl acrylate
Acrylic acid
Connection according to A

300

240

50

100

aqueous phase:

Water 540 g

non-ionic surface-active compounds 18 g

anionic surfactants
Connections 12 g

The reaction temperature was maintained at 68 to 70 ° C. The emulsion polymer obtained had the following Characteristics:

Polymer content
viscosity
pH
Particle size

= 47.5 .. = 500 cps = 7.5 = 0.1 to 0.2 microns

all films were clear H H

2H H

2H H H H

13 17 16 17 12 17 12 15

Film free monomers

clear.

constant

0.5%

Cross-connectivity:

The thermosetting composition of Example 20 provided films with the following properties:

Pencil hardness = H

MÄK extractable

Components = 20%

example

The procedure described in Example 20 was repeated except this time Methyl methacrylate was replaced by styrene, in the same weight ratio. The received Emulsion polymer showed the following properties:

60

55 polymer content
viscosity
PH value
Particle size

Film free monomers

= 47.6 = 700 cps = 7.5 = 0.1 to

0.2 micron = clear,

constant = 0.5%

Cross-connectivity:
With the thermosetting composition of Example 20:

Pencil hardness = H

MÄK extractable

Ingredients = 18%.

Example 22
(Comparative example)

Two hydroxyesters A and B were made. The hydroxy ester A, component (a) des copolymefs according to the invention was made according to the teachings of the parent application P 25 52 634 from propylene glycol, Isobutanol and maleic anhydride are produced. The hydroxyester B was according to the teachings of DE-OS 15 68 883 made from propylene oxide, isobutanol and maleic anhydride. The manufacture of the Hydroxyester took place under the same conditions; H. Lower Application of the same concentrations, des same catalyst and under the same temperature conditions.

The following results were obtained:

A B (as of

Technology)

Viscosity 35

(Sp. 1-20 turns
per minute) cps

Acid number 5.7

NMR analysis:
Maleate / Fumarate isomer 57/43.

Ratio of 1 / 2.18

Unsaturation / ester

Structure (assumed):

OH

CH-COOCHiHCH ₁
CH-COOCH ₂ CH (CH ₃ ) 2

87

93.4

93/7
1/1

CH ₃

CHCOOCH ₂ CH-OCOCh = CHCOOH
CHCOOCH ₂ CH (CHj) ₂

The high acid number of the Hydroxyestera B indicates thereupon that at least in part a non-monometonic product is present, d. H. that the monomer of specified structure is partially polymerized. In contrast, however, indicates the acid number of the Hydroxyester A, component (a) of the copolymer according to the invention, clearly indicates the presence of a monomeric compound.

The two hydroxy esters A and B vinyl acetate and 2-ethylhexyl acrylate became the copolymers! » A '(according to the invention) and B '(comparison).

The following table lists the physical properties of the emulsions produced:

A '(invention) B' (comparison)

Polymer content 54.0 54.3

viscosity

3/50 turns 890 710

per minute cps

3/50 turns 1560 1160

per minute cps

pH 5.1 5.1

Germ content ppm 1000 700

Bluish bluish film

Pencil hardness 3B-2B B

Crosslinkable film F H

Starting from the copolymer emulsions produced, Cross-linking experiments were carried out using ammonia and melamine it was found that emulsion B 'was completely unstable and coagulated when ammonia was added. Dhs indicates then that there was an excess of carboxyl groups. In contrast, the emulsion A 'behaved (Invention) absolutely stable.

Claims (1)

Patent claims: 1. Cross-linkable, thermosetting copolymer, obtained by copolymerization of of a diester of (a) 12.8 to 25 general formula: