DE2111332C3 - Process for the production of copolymers - Google Patents

Description

(a) 15 to 65 percent by weight styrene,

(b) 2 to 12 percent by weight hydroxyethyl

methacrylate, hydroxypropyl methacrylate, hydroxyethyl acrylate or Hydroxypropyl acrylate,

(c) 1 to 3 percent by weight acrylic acid or

Methacrylic acid,

(d) 12 to 30 percent by weight of an ether des

N-methylolacrylic or methacrylamides with a saturated alkanol, which has 1 to 8 carbon atoms,

(e) 10 to 55 percent by weight of an ester of

Acrylic or methacrylic acid with 1 to 10 carbon atoms containing saturated alkanol or a mixture of such esters and

(f) 2 to 15 weight percent hydroxyalkyl esters

the methacrylic acid or acrylic acid of the following formula

CH, = C-C

O - CH ₂

CH, CH CH ₃
O - CH ₁ - CH ■

O -

CH ₁

; - CH

OH

where η represents numerical values between 2 and 6, R is hydrogen or a methyl group and the compound of the formula I or their mixtures have hydroxyl numbers of about 100 to about 200, the sum of the percentages of the compounds designated by (a) to (f) in each case 100 is copolymerized by heating.

2. The method according to claim I, characterized in that a mixture consisting of:

(a) 30 to 45 percent by weight styrene,

(b) 5 to 10 percent by weight of hydroxyethyl

methacrylate,

(c) 1 to 2 percent by weight acrylic acid,

(d) 18 to 22 percent by weight of an ether des

N-methylol methacrylamide with
n-butanol or isobutanol or their mixture,

(e) 25 to 35 weight percent butyl acrylate or

2-ethylhexyl acrylate or a mixture thereof and

(0 5 to 10 percent by weight hydroxyalkyl esters of methacrylic acid with hydroxyl numbers from about 130 to about 150 is copolymerized.

3. The method according to claim I or 2, characterized in that the ether of N-methylol methacrylamide with n-butanol or isobutanol reaction products of methacrylamide, paraformaldehyde, Butanol and / or isobutanol, the molar ratios, based on 1 mol of methacrylamide, 1 to 1.5 moles of paraformaldehyde and I to 3 moles of n-butanol or isobutanol and an acid or an acid donating catalyst have been present in the manufacture is, is copolymerized.

4. The method according to any one of claims 1 to 3, characterized in that such ethers des N-methylol methacrylamide with n-butanol or Isobutanol are used, which contain the catalyst or its esterification products in their solution and maleic anhydride has been used as a catalyst.

5. Use of the copolymers obtainable by the processes mentioned in claims 1 to 3 as a binder or sole binder for stoving enamels.

40

45 Baked enamels are known from German Auslegeschrift I 102 410 which

I. organic solvents and
II. Copolymers from

A) esters of acrylic or methacrylic acid with alkanols,

B) Ethers of N-Methy! Olacryl- or methacrylic acid amide with alkanols or phenylalkanols,

C) Monoesters of acrylic or methacrylic acid with polyvalent hydroxyl compounds as well possibly additionally

D) another, an ethylenically unsaturated, copolymerizable one Group containing compounds, such as acrylonitrile, acrylic and methacrylic acid, higher esters of ethylene carboxylic acids, Contains styrene and vinyl acetate.

Such stoving enamels are characterized by a number of valuable properties.

The object of the present invention is in organic Solvent-soluble film-forming copolymers of styrene, acrylic acid, N-alkoxyalkylacrylic acid amides or N-alkoxyalkyl methacrylic acid amides, Hydroxyalkyl acrylates, hydroxyalkyl methacrylates and alkyl acrylates through special selection measures that are suitable for the manufacture of improved stoving enamels.

The invention relates to a process for the preparation of organic solvents

2 ill

transforming copolymers by copolymerization of styrene, acrylic acid, N-Alkoxyalkylacryliäurearoiden or N-Alkoxyalkylraethacrylsflureamilen, Hydroxyalkyl acrylates, hydroxyalkyl acetate acrylates and acrylic acrylates in organic solvents in essence of polymerization initiators 4nd regulators, characterized in that a mixture, consisting of:

(a) 15 to 65 percent by weight styrene,

(b) 2 to 12 percent by weight of hydroxyethyl meth-

Acrylic Hydroxypropyl methacrylate Hydroxyethyl acrylate or hydroxypropyl acrylate.

(c) Ibis 3 percent by weight acrylic acid or meth

acrylic acid,

(d) 12 to 30 percent by weight of an ether des

N-methylol acrylics or methacrylamides with a saturated alkenol, which has 1 to 8 carbon atoms,

(e) 10 to 55 percent by weight of an ester of the acrylic

or methacrylic acid having a saturated one having 1 to 10 carbon atoms Alkanol or a mixture of such esters and

(Π 2 to 15 percent by weight hydroxyalkyl ester of Methacrylic acid or acrylic acid following Foxmel

R O

^C ~ ^C CH, r CH, ι

O-CH, -CH ■ - [O-CH ₂ -CH 4-CH

- CH, - CH

OH

where η represents numerical values between 2 and 6. R is hydrogen or a methyl group and the compound of the formula I or its mixtures are hydroxyl groups from about 100 to about 200, the sum of the pro: nt numbers of those denoted by (a) to (Γ) Connections each is 100. copolymerize by heating! will.

A special preferred form of execution of the Process is characterized in that a mixture, consisting of:

(a) 30 to 45 weight percent styrene.

(b) 5 to 10 percent by weight of hydroxyethyl meth-

acrylate,

(c) I to 2 percent by weight acrylic acid.

(d) 18 to 22 percent by weight of the ether of the N-Me-

ethylene methacrylamide with n-butanol or isobutanol or a mixture thereof.

(e) 25 to 35 weight percent butyl acrylate or

2-Ethylhexylacr> lat or a mixture thereof, and

(0 5 to 10 percent by weight of hydroxyalkyl esters of methacrylic acid with hydroxyl numbers of about 130 to about 150
is copolymerized.

Another preferred embodiment of the method is that as the monomeric ether of the N-methylol methacrylamide with n-bulanol or isobutanol the mixture of the reaction products of methacrylamide, paraformulehyde, butanol and / or Isobutanol, the molar ratios based on 1 mol of methacrylamide, 1 to 1.5 mol of paraformaldehyde and 1 to 3 moles of n-butanol or isobutanol and an acid or an acid donor Catalyst has been present in the production, is used for copolymerization.

A special further embodiment of the process sees in the fact that such an ether of N-Methylolmcthacrylamids with n-butanol or Isobutanol is used, which in its solution the Catalyst or its esterification products revealing and with maleic anhydride as a catalyst

j _{0 has been} inserted.

Ethers of N-methylolacrylic are used as component (d) or methacrylamides with saturated alkanols. the 1 to 8 carbon atoms such as methanol. Ethanol. Propanol. n-butanol, isobutanol. Pentanol. Hexanol.

Heplanol. Contain octanol or 2-ethylhexanol, used. Ethers of N-methylolacrylic are preferred or -melhacrylamids with isobutanol or n-butanol.

The particularly preferred ethers of N-methylol methacrylamide with n-butanol or isobutanol sverden through a particularly suitable implementation of Reaction partner in the ratio of 1 mol of methacrylamide. 1 to 1.5 moles of paraformaldehyde with 1 to 3 moles of n-butanol or isobutanol and maleic anhydride in the warm with extensive water separation receive. A reaction product is best suited ·! ~ Ίι with ratios of reactants of 1 mole methacrylamide, 1.2 moles paraformaldehyde and 2 moles of n-butanol or isobutanol and 0.01 to 0.03 moles of maleic anhydride. The used Reaction mixture of methacrylamide, paraformaldehyde. n-butanol and maleic anhydride provides about 65 percent by weight -t 3 percent by weight of ether of N-methylol methacryl-

amides with n-butanol and about 35 weight percent ± 3 weight percent n-butanol. while in the implementation made of methacrylamide. Paraformaldehyde, isobutanol and maleic anhydride a product au; about 64 percent by weight ± 3 percent by weight ethi

of N-methylol methacrylamide with isobutanol by about 36 percent by weight ± 3 percent by weight iso hutanol is obtained.

The most preferred embodiment of the method; consists in that as the ether of N-methylolmeth acrylamides with n-butanol, the reaction mixture solution from the reaction of 4 moles of methacrylamide 4.67 moles of preformaldehyde, 8 moles of n-butanol -um 0.03 mol of maleic anhydride under water separation

2 III 332

received, uses. Such a reaction mixture contains approximately:

64.0 percent by weight of the ether of N-methylolmetbacrylamide with
n-butanol,
Butanol,

Paraformaldehyde,
Water,

Methacrylamide and
Maleic acid monobutyl ester.

32.5 percent by weight
0.8 percent by weight
1.6 percent by weight
0.6 percent by weight
0.5 percent by weight

Another reaction approach, which is also approved as the most preferred embodiment of the process, consists in the fact that the ether of N-methylol- »Ethacrylamids with isobutanol the reaction mixture Ipsung from the implementation of 4 mol methacrylamide, 4.67 mol paraformaldehyde, 8.0 mol isobutanol and 0.03 mol of maleic anhydride obtained with separation of water, used.

Such a reaction mixture lasts about

63.4 percent by weight

33.0 percent by weight
0.8 percent by weight
1.5 percent by weight
0.8 percent by weight
0.5 percent by weight

of the ether of N-Meth \ - lolmethacrylamids with
Isobutanol.
Isobutanol.
Paraformaldehyde.
Water,

Methacrylamide and
Maleic acid monoisoester.

If the ether of N-methylol methacrylamide is used with isobutanol with the monomeric compounds mentioned under (a) to (0. This is how products get the hard surface paintwork after baking result. However, if a product is desired which is more elastic after the baking process To show properties, a copolymer is made with the ether of N-methylolacrylamide with n-butanol and the monomeric compounds mentioned under (a) to (f).

As component (e), esters of acrylic or methacrylic acid with 1 to 10 carbon atoms are used containing saturated monoalkanol. such as methyl methacrylate, ethyl methacrylate, butyl methacrylate. 2-ethylhexylme; hacrylate, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-isobutyl acrylate or 2-ethylhexyl acrylate used. Preferred butyl acrylate, isobutyl acrylate or 2-atliylhexyl acrylate

As component (f) are hydroxyalkyl esters of methacrylic acid or acrylic acid, the esterification products of methacrylic acid or acrylic acid and Represent polypropylene glycol, used.

The polypropylene glycol residues contained in component (f) have a molecular weight of about 200 to about 500. These hydroxyalkyl esters of Methacrylic acid or acrylic acid have hydroxyl numbers from about 100 to about 200. The particularly preferred Hydroxyalkyl esters of acrylic or methacrylic acid have hydroxyl numbers from about 130 to about 150.

As a solvent for the copolymers according to the invention are the usual, such as alkyl

benzenes, such as toluene and xylene, alcohols, such as η- um Isobutanols, monofilters of diols such as ethanediol monomethyl ether, esters of alkanols such as vinegar sii ureö thy! ester, and monoether roonocster of Di oils, such as ethanediol monomethyltroonoacetic acid ester as well as mixtures of such substances with one another or with hydrogenated gasoline.

The copolymers can be produced in the customary manner, generally expediently by solution polymerization in solvents that are also part of the finished stoving lacquer meant to be. The polymerization can expediently or by the customary initiators Initiator systems are initiated from initiators and activators.

All compounds which form free radicals under the reaction conditions are suitable as polymerization initiators for the process according to the invention. Peroxy compounds and azonitriles are preferred. Examples of suitable peroxy compounds are dibenzoyl peroxide. Diiai ' ^r oyl peroxide, dimetal peroxide. Dietary peroxide, di- 'tert-butyl peroxide. Dioctadecyl peroxyd. tert-butyl peroxypivalate, disuccino peroxide. Urea peroxide. Peracetic acid and perbenzoic acid, alkyldialkylboroperoxides and alkali persulfates, perborates and percarbonates, each alone or in combination with a reducing agent. Examples of suitable azonitriles are 1,1-azodicyclohexanecarbonitrile. o, </ - azobis- (n-cyclopropylpropionitrile). «.« '- Azobis-fisobutyronitrile), «, u'-Azobis - ('i,; - dimethy] valeronitrile),«, a'-Azobis- (a-methylenanthronitrile). (Jr / '- Azobis- (n -phenylpropionitrile) .a.a'-azobis- (n-cyclohexylpropionitrile), u, n'-azobis- (n-methyl-;. -carboxy butyronitril). disodium-y,>'' - azobis - (; - cyanovalerate ).!, I'-azodicamphane carbonitrile.

By using the usual regulators such as mercaptans and aldehydes, the degree of polymerization and thus the viscosity of the copolymers on the desired dimension set. As turn-regulating mercaptans come butyl mercaptans, octyl mercaptans. Laur>! Mercaptane and tert-dodecyl mercaptan are preferred for use.

A preferred process ? .ut production of the new copolymers consists in adding isobutanol to the solvent mixture, which is heated to the re-nut temperature and consists of xylene / n-butanol or xylene, the ratio of xylene to n-butanol or isobutanol from 1 to 10 to 2 to I can be parts by weight, the monomer mixture, including the polymerization catalysts and chain regulators, separately or as a mixture over a period of about one to ten hours, the polymerization temperatures should be between W) to about 125 ° C. The polymerization is then about 6 to 14S'undcn in order to achieve the most complete conversion of the monomers possible 60 to 125 ° C remains iben.

In the preferred embodiment of the process, the polymerization initiators or catalysts are in amounts of 0.8 to 1.5 percent by weight, based on the weight of the monomer mixture, most suitably using di-tert-bulyl peroxide is used.

In the preferred embodiment of the method the chain regulators are used in amounts of 0.5 to 1.5 percent by weight, based on the weight of the monomer mixture, most suitably tert-dodccyl mercaptan is used.

The quantitative as well as special qualitative selection of the monomeric components (a) to (0 were obtained improvements in the copolymers and the stoving enamels produced with them surprising and unpredictable.

Particularly suitable copolymers which are dissolved in 50 percent by weight in a mixture of xylene / n-butanol or xylene / isobutanol are those which have a Gardner-Holdt viscosity of I to Z at 20 ^° C.

The copolymers obtainable according to the invention are distinguished in particular by the fact that they are a have improved pigment binding capacity and the coatings produced with them already at relatively practically fully develop their valuable properties at lower stoving temperatures. Furthermore, from with such copolymers! varnishes produced varnishes with improved adhesion and impact resistance as well as with particularly pronounced elasticity, weather resistance, hardness and saponification resistance receive. If desired, coatings can also be obtained that also have other properties, such as light resistance, flexural strength, solvent resistance and temperature resistance own to a special degree.

The copolymers obtainable according to the invention can be used to produce stoving enamels which, if desired, contain the additives customary in stoving enamels, such as pigments, soluble dyes, optical brighteners and agents to promote leveling and gloss. In particular, the stoving enamels can contain, in addition to the copolymers, other customary lacquer binders, such as alkyd resins, aminoplast resins, phenoplast resins, epoxy resins, cellulose derivatives and polymers which are not identical to the copolymers of this invention, dissolved and / or dispersed. The weight ratio of the copolymers to the additional other paint binders should in general expediently be greater than 1, in particular greater than 2. The type and amount of the usual other paint binders added to the copolymers must be coordinated in such a way that clear solutions and clear films are obtained after the stoving process. It has also generally proven to be useful if the weight ratio of the solvent to the total proportion of binder in the stoving enamels is from about 0.4 to 3, in particular from about 0.6 to 1.5.

To produce coatings, the stoving enamels based on the new copolymers can be applied to the objects to be painted using the customary methods, e.g. B. by spraying, brushing on, pouring on, rolling on, flooding, dipping or soaking. The baking of the coatings can generally advantageously carried out at temperatures from about 120 to 180 ° C, in particular about of 130 to 150 ⁰ C and, in function of the temperature, over a period from about 5 to 120 minutes, more preferably about 20 to. 40 minutes. Since the valuable properties of the paintwork come into their own on metals such as iron, aluminum, magnesium and alloys of these metals, the stoving paints are particularly suitable for painting objects made of sheet metal, e.g. B. Body parts. Ships, washing machines and ice boxes, as well as cans, jugs, vats and appliances for industry and household. The stoving enamels can be used equally for the production of base and top coats: because of their adhesive strength, they are also very suitable for the production of one-coat finishes on metals, with the high one

ίο Surface gloss generally a re-polishing makes dispensable.

When the paintwork is to be baked at the lowest possible temperatures and / or Baking enamels are used which polymerize relatively little acrylic or methacrylic acid into the copolymer it may be useful to bake the stoving enamels in the presence of curing agents to burn in. As such, common acids or acid-releasing acids are suitable for curing polymers Substances such as p-toluenesulfonic acid, phosphoric acid, maleic acid or tartaric acid. The amount of hardening agent should in general be expedient about 0.01 to 5, in particular about 0.1 to 2 percent by weight of the copolymers.

The stoving enamels are preferably used with the identified copolymer as the sole binder used for single-layer paints. However, if stoving enamels or multi-layer stoving enamels with particularly high solvent resistance and excellent surface hardness and gloss retention are required for weathering, the marked copolymers are used in combination used with aminoplasts.

Preferred aminoplasts are condensation pro-

products from formaldehyde and melamine, with either about 4 to 6 moles of formaldehyde per mole of melamine weakly acidic or weakly basic have come to the reaction and with butanol, isobutanol or methanol almost completely about 80 to 100% should be etherified.

The resulting reaction products should have a molecular weight of about 300 to 1200 and in organic solvents such as xylene and n-butanol, isobutanol, methanol or glycol

ethers and other alcohols be soluble. Recipes for suitable melamine resins are given as examples in Swiss Patent 480 380 and in German Auslegeschrift 1 127 083.

The copolymer and the aminoplast wcien im

Ratio of 65 to 95 parts by weight of the copolymer and from 5 to 35 parts by weight of the aminoplast resin dissolved in the organic solvent. the The proportions of the copolymers and the alkylated aminoplast are to be chosen so that the

both components both in the coating solution as well as in the finished film. It can * any suitable Concentration of the copolymer and the aminoplast in the solvent of e.g. B. 1 to 50 percent by weight under this condition to

turn come.

If a pigment is present, the total solids content in the coating mass is between 5 and 75 percent by weight. The ratio of pigment to binder (copolymers plus aminoplast) can be between

see 1:20 and 1: 2 lie.

The copolymers given in the table below were made according to the general procedure of Example 1 produced.

409 640/155

ίο

Copol} -

Component (ill
in percent by weight

30 styrene

30-65 styrene

35-50 styrene

30- ^ 5 styrene

15-35 styrene

25-55 styrene

Component (h)

in Gewidlls-

prn / cnl

5-10 hydroxyethyl methacrylate

4-8

Hydroxyprupyl methacrylate

4-8

Hydroxyethyl methacrylate

4-8

Hydroxypropyl acrylate

5-8.

Hydroxy

ethyl acrylate

5-8

Hydroxy

ethyl acrylate

Component IcI

in Cicwiclils-

per / enl

2-3 methicrylic acid

I-2 acrylic acid

2-3 methacrylic acid

I-2 acrylic

acid

I-2 acrylic acid

2-3 methacrylic acid

Component KlI

in weight

pro / ciil

15 20

Methyl ether

from

N-methylol

acrvlamid

12-25

n-butyl

later from

N-methylol

methacrylic

amide

18-27

n-butyl

ether of

N-methylol

melhacrylic

amide

15-25
n-Butyl ether of N-Methyloi methacrylamide

12-2 .;

n-butyl

ether of

N-methylol

methacrylic

amide

15-30

Octyl ether

from

N-methylol

acrylamide

Component (0
in weight
percent Viscosity according to G ii r (1 η c r 11 ο ul I <omponen! e IeI
in weight
percent Sogcwichls-
percent in
Xylene / butano!
in weight 10 15 ratio I; I. Hydroxy at 20 C ' alicyl ester measured 10-30 the acrylic X-Z VIethylmeth- acid according to acrylic Formula I, 20-50 Hydroxyl 2-ethyl number 110 hexyl acrylate 3 8 Hydroxy alkyl esters 15-50 the acrylic R-V 2-ethyl acid hexyl acrylate according to Formula I, Hydroxyl number 150 4-10 Hydroxy alkyl esters 20-40 the meth T-X Butyl acrylate acrylic acid according to ^ Formula I * Hydroxyl number 150 4-15 Hydroxy alkyl esters 20-45 octyl the meth U-Y acrylate acrylic acid according to Formula I, Hydroxyl number 150 5-12 Hydroxy allyl ester "^; 10-40 octyl the meth T-X acrylate acrylic acid 10- ^ 40 - according to , ■ · ■>, - ■■ - ;? - *. ■■ · ■ ·:} Ethyl acetate Formula I, Hydroxyl number 180 5-15 Hydroxy alkyl esters 20-50 the meth ¹ T * ^^ n-butyl i acrylic acid acrylate according to Formula I, Hydroxyl number ί50 ";:;

Component. Ι ») 11th 2 1 1 1 332 Component (d) I. 12th Viscosity according to in weight in weight Gardner - percent continuation percent Moldl iOgewichls-
nro7cntii * in I Ί wA ^ I 11 J ^, III
X viol 'Ru tu no I Component (b) Component If) in weight 30-65 styrene in weight Component Ic) 15-30 Component (el in weight ratio I: I ITl C Γ1S 'I \ percent in weight Oclyl ether in weight percent at 20 C- percent from percent measured N-methylol T-Y acrylamide 4-10 5. 8 G Hydroxy 1 -2 acrylic 20-50 Hydroxy propyl acid Decyl alkyl esters 30-50 styrene acrylate 18-22 acrylate of acrylic n-butyl ether acid according to from Formula 1, N-methylol Hydroxyl U-X methacrylic number 200 5 - 10 amide 5 8 H Hydroxy 1.5-2.5 25-35 Hydroxy ethyl- Acrylic acid n-butyl alkyl esters methacrylate acrylate the meth 35-45 styrene 18-22 acrylic acid n-butyl according to ether of Formula I, N-methylol Hydroxyl U-Y methacrylic number 150 5-10 amide 5 - I0 I. Hydroxy 1-2 acrylic 25-35 Hydroxy ethyl acid 2-ethyl alicyl ester of 30-45 styrene methacrylate 18-22 hexyl acrylate Methacrylic i-butyl ether acid according to from Formula I, N-methylol Hydroxyl T-X methacrylic number 150 4-10 amide 5-10 J Hydroxy I - ^ acrylic 25-35 Hydroxy ethyl- acid n-butyl alkyl ester of 35-45 styrene methacrylate 18-22 acrylate Methacrylic i-butyl ether acid according to from Formula I, N-methylol Hydroxyl -j- γ methacrylic number 150 5 -8 amide 5-8 K Hydroxy 1-2 acrylic 25-35 Hydroxy ethyl- acid 2-ethyl alkyl ester of methacrylate example 1 hexyl acrylate Methacrylic ■ "■ - '-' ■.... Making the acid according to Formula I, Hydroxyl number 150 Polymer solution 1

In one with stirrer, reflux cooler and thermometer The equipped flask is poured into a mixture consisting of 317 g of xylene and 163 g of n-ButanoI, under Boil the following 65 in a steady feed for 4 hours Mixture added: 225 g styrene, 11 g acrylic acid, 30 g of hydroxyethyl methacrylate, 175 g of 2-ethylhexyl acrylate, 9 g tert-dodecyl mercaptan, 8 g di-tert-butyl

peroxide, 43 g of a 70 weight percent xylene solution of the hydroxy alkyl ester of methacrylic acid, which is an esterification product of methacrylic acid and polypropylene glycol with a hydroxyl number of about 130 represents and 184 g of a 65 percent by weight butanolic solution of the ether of N-methylol methacrylamide with n-butanol as a proportion of

Pendulum hardness according to

king

Buchholz hardness ..
Scratch resistance ..

EinbrennlempcraUircn and - / rush

JO min. 15 (V C

143 "

125
1-2

15 min. 180 C

148 "

133

30 min. ISO C

147 "

133

1 = paint surface is by scratch test with the fingernail

not vulnerable.

2 = Paint surface is by felt test with the fingernail

scratchable.

elasticity

Erichsen cupping

Deep-drawn sheet

Erichsen cupping

Bonder plate 97. ..
Mandrel bending test

ASTM D-522

Erichsenblech

Mandrel bending test
ASTM D-522
Bonder plate 97 ...

0 = flawless.

1 = 0.1 to 0.5 cm torn.

Stoving temperatures and times

30 min. 150 C

7.7mm 4.5mm

15 min. ISO C

7.2 mm 4.9 mm

30 min. 180 C

6.8 mm

4.0 mm

Long shine,
measured at an angle
45 °

Baking temperatures and times

30 min .. '150C

103%

15 min. 180 ^° C

108%

30 min. 180'C

a Reuktionsansatz is present, made from 4 mol Methacrylamide 4.67 moles paraformaldehyde. 8 moles of n-bulanol and 0.03 moles of maleic anhydride in the Bath with extensive water separation.

Subsequently, another is polymerized for 8 to 10 hours under boiling until the solution has a body content of 50 weight percent, and the viscosity of W to Y, as measured by G ard nervous H I ο dt at 20 ⁰ C,.

Use of the copolymer I

54 g of this copolymer solution I are mixed with 32 g of tilanedioxide pigment (rutile) and 9 g of xylene and 2.5 g Ethyl glycol acetate was homogenized on a ball mill for 24 hours. After subsequent dilution uuf Spray viscosity with a mixture of xylene and ethyl glycol is the sprayable stoving enamel zinc-phosphated steel sheets as well as untreated steel sheets applied, ventilated and between 150 Baked in up to 180 ° C in 30 minutes.

hardness

Resistances

Detergent solution.
Detergent solution.

Xylene

40 to 45; i Burning temperature 30 min.. Shift - 150 C " strength Dry- W Min .. Movie 140 C 0 Burden 0 length of time 0 0 3 rounds gi 4 rounds mO-m 1 I. 6 '

15 min ..! XO C

1 round = 2.5% detergent solution, boil for 8 hours,

16 hours in lye at room temperature, g = 0. no bubbles.

g I = bubbles barely visible to the eyes. g2 = slightly larger bubbles,
m = amount of bubbles.
rough = no bubbles,
m 1 = 20% bubbles on the surface. m2 = 40% bubbles on the surface. XyIoIO = Not attacked.

1 = surface scratchable, no swelling.

2 = surface scratchable, slight swelling.

3 = scratchable paint film, slight swelling.

Salt spray test according to ASTM B-117-64

.

Bonder plate 97

Bonder plate 97

load duration

240 hours

500 hours

Burn-in temperatures and - / rush

30 min., 15 minutes., 30 min. 150 C 180 C ISO C " Obis Obis Obis 1.0 mm 1.0 mm 1.0 mm 1.0 to Obis Obis 2.0 mm 1.0 mm 1.0 mm

Infiltration at the St. Andrew's Cross is given in millimeters.

Kesternichtest

Bonder plate 97

5 rounds

blow

blow

blow

The sheets are placed in a chamber with 3001

Volume hooked into which a temperature

of 40 ± 3 ° C and 100% relative humidity

prevails. In addition, 21 sulfur dioxide are in

initiated the closed chamber.

1 lap = 8 hours of exercise as described above and 16 hours at room temperature.

99%

6o shine East Therm. Aging at 140 "C 200 hours 300 hours 400 hours 500 hours 5 ₅ after 100 hours Longing, 45 ° Yellowing 102 104 105 104 104 -11 105 + 1 + 15 + 21 +26 -11.5

2 ill

The cloudiness is measured by the leukometer in comparison to magnesium oxide as normal white. The value O = MgQ.
Minus values whiter than MgO. Plus values more yellow than MgOi

Compatibility with AJkydbarzen

IO

Mixed hanging I ') in solution Im turned 2 ² Jm solution Im turned ratio. burned burned Mixed poly Movie Movie merisat / ver ver Alkyd bearable ver bearable ver 90:10 the same bearable the same bearable the same desgh the same the same 75:25 the same the same the same the same 50:50 the same the same the same the same 25:75 the same the same 10:90

15th

20th

1 ') Alkyd resin, consisting of 33% ririnen oil, trimethylolpropane

and phthalic anhydride.
2 ² ) Alkyd resin, consisting of 40% ricin oil, glycerine and phthalic anhydride.

Comparative experiment

In a comparative experiment, the procedure is the same as that given in Example 1, but with the Exception that when producing the copolymer instead of hydroxyalkyl esters from methacrylic acid and polypropylene glycol the same amount of hydroxyethyl methacrylate is used. The data are on a bonded sheet steel (Bonder 97) using a pigmented varnish and in> reproduced in the table.

The new copolymers of the present invention show in lacquer behavior all previously known binders a sum of excellent properties that in general only through several binders and then only in certain areas of the surface protection of sheet metal be considered. The mechanical bonding as well as the surface hardness, elasticity and durability against washing liquor and solvents, as also show the hardly occurring yellowing, that beer binder with completely surprising, unexpected optimal properties are present.

Use of the copolymer I
in a single coat

Stoving conditions
150'C, 30 min. According to the invention
example 1 Comparison attempt Erichsen cupping 4.5 mm 2.3 mm Mandrel bending test after ASTM D-522 over one 6 mm mandrel perfect Painting flakes off

Parts by weight

52.00
2.00

32.00
6.10
2.00
3.00
1.00

100.00

Components

Copolymer I

Epoxy resin based on bisphenol A and epichlorohydrin with an epoxy equivalent weight
from 450 to 525, an epoxy value of 0.19 to 0.22 and a softening point according to D urra η s of 65 to 75 ° C

Titanium dioxide (rutile)

Xylene

Solvesso 150 (solvent)

Ethyl glycol acetate

Silicone oil L 050 1% in xylene

Bentone 34 paste 10% in xylene

40

45 Gardner-Holdt viscosity »J« at 20 ^° C.

Ratio of binder to pigment = about 1: 1.2. Adjustment with solvent mixture to spray viscosity.

Mixed solvent

35.00 xylene
20.00 butanol
30.00 Solvesso 150
15.00 ethyl glycol acetate

Stoving conditions

30 minutes - 140 ⁰ C - 150 ⁰ C
15 minutes - 170 ° C - 180 ⁰ C

Claims (1)

2 ΠΙ Patent claims: I. Process for the preparation of film-forming copolymers which are soluble in organic solvents by copolymerization of styrene, acrylic acid or methacrylic acid, N-alkoxyalkylacrylic acid amides or N-Alkoxyalkylraetbacrylsäurearaiden.Hydroxyalkylraethacrylaten or Hydroxyalkylacrylaten and alkyl acrylates in organic solvents in the presence of polymerization initiators and regulators, characterized in that a mixture consists of out: