DE1644768B2 - COATING MATERIAL - Google Patents

Description

The invention relates to a coating material based on cellulose ethers and / or Cellulose esters, araliphatic hydrocarbons, stabilizers and antioxidants and optionally resins, plasticizers and waxes. It is known workpieces, especially those that have a finely machined surface, or at risk of breakage or with Precision manufactured are provided with a homogeneous coating that has a common Body forms with the workpiece, the shape details of the workpiece adapts, and easily and without special tool or device can be removed again (see leaflets from Hercules Powder Company (1949), February 1952, on "Ethyl. Cellulose "and" Easy-off Overcoats for Metal Parts "; U.S. Patent No. 3,051,670). The known coating materials based on cellulose ethers and / or Cellulose esters, for which it has also already been proposed to add naphthenic oil, have hitherto been considerably high production price and only offer insufficient stability under normal conditions of use. This is mainly due to the fact due to the fact that such coating materials are heated to temperatures of the order of 180 to 190 ° when used over several days must be, whereby the bath surface is in constant contact with the air under constant surface renewal. It inevitably happens to oxidation and overheating phenomena, which lead to a deterioration of the compositions, all the more rapidly than the application temperatures are increased. In the case of the known coating materials, the corrosion protection achieved is also the coated surfaces only limited because the acidify known coating materials quickly. The same applies to the ability to To offer protection against impact and handling of the workpieces, since the mechanical properties of the coating materials deteriorate at the same time as oxidation and overheating phenomena.

Eventually, the coatings tan and lose their transparency, which can lead to the Marks and other symbols attached to workpieces can no longer be easily identified.

These deficiencies also occur with known coating materials containing 0.1 to about 3.0 percent by weight of the solids content of crystalline polymer Contain polyvinyl cyclohexane, polyallyl cyclohexane or poly-4-phenyl-1-butene (see US Pat 30 57 670).

It has now surprisingly been found that the above-mentioned deficiencies can be eliminated very satisfactorily by adding liquid araliphatic hydrocarbons and in significantly larger quantities to the coating material will.

According to the invention, the coating material consists of

1) 18 to 45 percent by weight of cellulose ethers and / or cellulose esters,

2) 35 to 60 percent by weight of liquid araliphatic hydrocarbons obtained by reacting one or more aromatic hydrocarbons with one or more araliphatic ones Hydrocarbons with 10 to 40 carbon atoms produced in the presence of a Friedel-Crafts catalyst and subsequent rectification have been, or

2a) 30 to 70 percent by weight of a mixture of such araliphatic hydrocarbons with a mineral oil, the mineral oil content should be 10 to 80 percent by weight,

3) 0 to 20 percent by weight resins,

4) 0 to 10 percent by weight wax,

5) 0 to 65 percent by weight plasticizers,

6) 0.1 to 2 percent by weight of stabilizers, antioxidants and neutralizing agents.

Such a coating material requires lower temperatures for the coating of workpieces and forms clear, transparent skins with a pleasant smell, with good protection against impacts, against long-term contact with water, brine and corrosive chemical solutions as well as with good Protection against weather influences. These skins also have a relatively high softening temperature and thus in particular satisfy the Conditions for hot countries.

The term "araliphatic hydrocarbons" stands for liquid polymerization products of aromatic hydrocarbons with araliphatic hydrocarbons with 10 to 40 carbon atoms. These can be fractions of special petroleum or synthetically produced hydrocarbons. In particular, the araliphatic hydrocarbons used for the synthetic production of the araliphatic hydrocarbons can by Fisher-Tropsch synthesis or by polymerizing olefins such as ethylene, propylene or butylene getting produced. It can also be olefins which are obtained by dehydrochlorination of Chloroparafons, i. H. chlorinated paraffins, or by thermal cracking of paraffins. That

Polymerizing with aromatic hydrocarbons can be done with the help of catalysts, for example Aluminum chloride, zinc chloride, sulfuric acid, orthophosphoric acid, etc.

In this way, clear products with a more or less large molecular weight can be obtained, which are more compatible than mineral oils with all types of resins, i.e. resins. the extracted products can be mixed with plasticizers from mineral oils or vegetable oils, have an aniline point fluctuating between 40 and 60, a flash point fluctuating between 125 and 205 °, a slightly aromatic odor, a low density between 0.870 and 0.880 and finally a vapor pressure at 220 ° that does not exceed 35 mm of mercury, even if you have the Conceivably most volatile products of the product group within the scope of the invention are considered

Such araliphatic hydrocarbons have the advantage that they have special balancing and harmonizing properties Make mixtures of poorly tolerated ingredients homogeneous at all temperatures. In this way it is possible to reduce the expensive components in coating materials by about 35%, whereby such coating materials become cheaper and, moreover, obtain even better properties.

For the purposes of the invention between 0 and 20 percent by weight, preferably 5 to 15 percent by weight, as auxiliaries or fillers of the cellulose derivatives or resins to be used as plasticizers are:

Glycol ester or glycol or pentaerythritol and

of hydrogenated rosin;

modified alkyd resins;

Urea-formaldehyde resins; Resins made from urea, melamine and formaldehyde; Coumarone resins and indene resins;

esterified natural rubbers;

pure or modified phenolic resins;

Aryl sulfonamide resins;

chlorinated diphenyl resins,

metallic resinates, etc.

For those in amounts between 0 and 10 percent by weight, preferably 1 to 8 percent by weight, the Waxes that improve touch and prevent exudation can be considered:

Esters of fatty acids with

high molecular weight;

Amides of fatty acids, beeswax;

Japanese candelilla wax, oricuri;

Montan wax; Spermaceti; Lauric alcohols; Cetyl alcohols; Stearic alcohols; Linseed oil fatty acids; Stearic acid; Paraffin;

hydrogenated castor oil;

microcrystalline waxes, etc. For the plasticizers to be provided in amounts between 0 and 65 percent by weight, preferably 5 to 35 percent by weight, the following can be considered:

phosphoric acid esters, phthalates, abieta te;

Citrates; tartrates; methylcyclohexyl lactate; Mannitol propionate; methyl cyclohexyloxalate; Ricinoleate; Adipates; Sebacates; Lauric acid butylamide; Diethyl diphenyl urea; Fatty acids;

raw or blown oils of castor, cotton,

Linen or grain. For the 0.1 to 2 percent by weight stabilizers, Antioxidants and neutralizers come into consideration:

Phenol and its derivatives; Epoxy resins; epoxidized oils; Metal carbonates. S To use the coating materials according to the invention, they must be liquefied by heat, in general by heating to temperatures of 150 ° to 190 °. The ones to be coated Workpieces are in the liquefied coating

immersing ro materials. The contact time can be limited to a few seconds so that the workpieces to be coated are coated or wetted with the material. The following are some typical implementations games for coating materials according to the invention Training and results of tests carried out with them and comparative examples with known ones Materials reproduced. To carry out such experiments were about 1 kg of each coating material heated in a steel container by means of an air bath that itself again through an oil bath with electric

Heating resistors was heated. The whole was continually continued through

Temperature measurement and automatic regulation controlled The capacity of each container was about 2 liters. Each coating material was exposed to the open air for the duration of the test Left in contact, whereby the standing height of the

molten material was about ² Ii the height of the container.

After careful degassing of the coating material to be examined, measurements of tensile strength, elongation, thickness and the exudation of the protective skins immediately coated metallic test pieces. The coating temperature was according to the previous tests chosen to the effect that with a new material on a test piece of steel of 3 mm own thickness a Coating with a thickness of 2mm ± 5% was achieved. For the course of the experiments this Temperature kept constant. The coating materials were not stirred, and the immersion time was Specimens was 5 seconds. The exudation after a stay in the warming cabinet from 24 Hours measured at 7 Γ. The specifications marked with "parts" in the following examples are Weight information.

Embodiment la Ethyl cellulose 20 parts Clear microcrystalline wax,

melting at 77 ° 8 parts

p-coumarone-indene resin, melting at 80 to 85 ° 7 parts

Araliphatic hydrocarbon

with molecular weight 320 49 parts

Clear paraffin oil with a viscosity

according to E η g 1 e r of 6.1 at 50 ° 15 parts

Octylphenol 1 part

The araliphatic hydrocarbon used in this exemplary embodiment is one that is obtained when propylene is _{polymerized on benzene in the presence of AlCl 3} f> 5, and the crude polymerization product is rectified under atmospheric pressure and with retention of the fraction evaporating between 270 and 355 ° .

Comparative example Ib

Ethyl cellulose

Clear microcrystalline wax,
melting at 77 °
p-coumarone and indene resin,
melting at 80 to 85 °
Naphthene oil (viscosity according to

Engler 247 at 50 °) Ethyl cellulose 64 pieces 10 Octylphenol Esters of pentaerythritol and ITeil la hydrogenated rosin New Raw castor oil 155 Coating temperature (° C) Araliphatic hydrocarbon with 2.1 Thickness (mm) Molecular weight 370 29.6 Tensile strength (kg / cm ² ) White paraffin oil (viscosity according to 71 Strain(%) Narrow 5.5 at 50 °) 5.1 Exudation (%) Methylphenol 165 Flash point (° C) 11.1 Decrease (%) in tensile strength 1.4 Decrease (%) in elongation Embodiment 2a 24 parts 30th 5 parts 5 parts 55 pieces 35 10 parts ITeil

This comparative example differs from the

Embodiment only in that instead of

Parts araliphatic! Hydrocarbon and paraffin oil

Naphthenic oil was used. In both cases you were

Part 5 strives to have an aniline point between 60 and 75 ° to be observed on the one hand for araliphatic hydrocarbons and parts of paraffin oil and on the other hand for naphthene oil. The comparison of the properties of the hides obtained according to the two examples results from the following Tabel:

Ib

aged New (85 hours) 155 170 2.2 2.0 26.3 28.7 70 58 - 6.0 170 18.5 15.5

aged
(85 hours)

170
2.2
23.4
49

This is the fraction that evaporates between 315 and 390 °.

Comparative example 2b

Ethyl cellulose

Esters of pentaerythritol and

hydrogenated rosin

Raw castor oil

Clear naphthenic oil (viscosity according to

Engler 6.7 at 50 °)

Methylphenol

24 parts

5 parts
5 parts

65 pieces
ITeil

The araliphatic hydrocarbon with molecular The comparison of the properties of those from these

weight 370 is made as in example la, but it results in 4 ° protective skins obtained in both examples:

Coating temperature (° C)

Thickness (mm)

Tensile strength (kg / cm ² )

Strain(%)

Flash point ( ⁰ C)

Decrease (%) in tensile strength

Decrease (%) in elongation

In these two examples the effect of heating is clearly evident. For the material after Comparative example 2b one was forced to maintain a temperature of 180 ° during the experiment, because you could only achieve a homogeneous mixture at a temperature of around 170 ° and it is necessary has been to use a temperature of 180 ° to achieve a coating thickness of 2 mm, while in the case of Betspiel 2a by using the araliphatic hydrocarbon, a temperature of 160 ° was sufficient. The profit is considerable. That Product according to Comparative Example 2b results after

2a aged 2 B aged New (85 hours) New (85 hours) 160 180 160 2.3 180 2.2 2.0 37.8 2.0 33.0 40.2 65 39.7 48 68 - 60 - 195 201 5.9 16.8 4.4 20.0

Aging protective skins with strong coloring or discoloration.

Exemplary embodiment 3a

Cellulosic Acetobutyrate 30 parts
Araliphatic hydrocarbon

with molecular weight 370 39 parts

Raw castor oil 20 parts

α-methylstyrene resin 10 parts
Magnesium carbonijt 0.1 part

Epoxy resin 1 part

16 44 VbB

Comparative example 3b

Cellulose acetobutyrate
castor oil

30 parts, 59 parts of α-methylstyrene resin
Magnesium carbonate
Epoxy resin

10 parts 0.1 part 1 part

The comparison of the protective skins obtained with these two examples is as follows:

3 a new

Coating temperature (° C)
Thickness (mm)
Tensile strength (kg / cm ⁷ )
Strain(%)
Exudation (%)
Flash point ( ⁰ C)
Decrease (%) in tensile strength
Decrease (%) in elongation

The differences here are very significant. It should also be noted that the in the embodiment 3a used araliphatic hydrocarbons »· toffees aliphatic Alcoholic constituents and the only oily products of mineral origin that are compatible with cellulose acetobutyrate. They are different from the others Embodiments used araliphatic carbon

3b aged New (H) O hrs.) 150 175 2.0 2.1 43.7 40.0 55 61 - 5.0 - 235 13.5 1.6

aged (100 mercenaries)

175 2.0 34.6 60

Embodiment 4 Stabilizers Cellulose acetobutyrate 25.0 parts 35 (epoxidized soya oil) Araliphatic hydrocarbon Chelating agent with molecular weight 450 30.0 parts Magnesium carbonate Clear mineral oil (viscose after Fragrance Engler 9.2 at 50 °) 12.0 parts Dioctyl phthalate 30 parts

lenwasserstoffen by the fact that alcohols corresponding to the number of carbon atoms are aliphatic Hydrocarbons were used in the production of araliphatic hydrocarbons, The araliphatic hydrocarbons used in embodiment 3a are, moreover, a fraction which evaporates at 315 to 390 °.

2.0 parts 0.85 parts 0.10 parts 0.05 parts

709 517,

5 607

Claims (6)

Claim: Coating material on the basis of cellulose ethers and / or cellulose esters, araliphatic hydrocarbons, stabilizers and antioxidants and optionally resins, plasticizers and waxes, characterized in that the coating material consists of 1) 18 to 45 percent by weight of cellulose ethers and / or cellulose esters, 2) 35 to 60 percent by weight of liquid araliphatic hydrocarbons obtained by reacting one or more aromatic Hydrocarbons with one or more aliphatic hydrocarbons with 10 to 40 Carbon atoms in the presence of a Friedel-Crafts catalyst and then Rectification have been made, or 2a) 30 to 70 percent by weight of a mixture of such araliphatic hydrocarbons with a mineral oil, the mineral oil content should be 10 to 80 percent by weight, 3) 0 to 20 percent by weight resins, 4) 0 to 10 percent by weight wax, 5) 0 to 63 percent by weight plasticizers, 6) 0.1 to 2 percent by weight of stabilizers, antioxidants and neutralizing agents there is no