BE370865A - - Google Patents

Description

       

   <Desc / Clms Page number 1>
 



   Improvements to the compositions for plaster as well as to the methods of manufacture and application thereof.



   The invention relates to compositions for coatings and coating systems more particularly intended to dry in relatively short times.



   In finishing articles by applying a series of coats of paint, the practice has always been to allow each coat to dry thoroughly before applying the next coat. Now, in the automobile industry, in which the speed of manufacture is an important factor in lowering the cost price, many efforts have been made to facilitate painting operations.

   In one of these processes, air drying is replaced by baking or steaming, but although this substitution results in a significant reduction in drying time, baking cannot be performed at very high temperatures, because it has a harmful effect on the body to be painted, in particular if, as is often the case, the body in question includes pieces of wood with glued joints.

   Another process used to facilitate the painting operation

 <Desc / Clms Page number 2>

 is to use quick-drying pyroxylin coatings, but these coatings are expensive and have difficulty in adhering to the metal of the body to be painted, unless it has been thoroughly cleaned, which in turn presents difficulties and incurs costs.



   In recent years, it has therefore been common practice to form the complete coating by first applying a series of sub-layers (or primer coats) without pyroxylin so as to ensure good adhesion to the metal of the coating. crate and 'to constitute a good base, with steaming of each of the layers separately, and ending with the application of one or more superficial layers based on pyroxyline. accompanied by suitable sanding operations.



   The present invention refers generally to the set or system of coating layers which lie beneath the surface layers and which will be referred to as the "underlay or neck system. - basecoats ',' and mainly to the primer coats.



   Before describing the features of the invention, it seems useful to first define some of the expressions used below. By "resin based on polyhydric alcohols and polybasic acids" is meant substances which comprise the reaction product of one or more polyhydric alcohols, at least one polybasic acid (with or without monobasic acids) and one or more oils or oily acids, added (or replaced by) natural gums.

   by the expression "oily type" or "oily type vehicle" is meant products containing appreciable amounts of drying or semi-drying oils and comprising natural or synthetic gums, such as "Amberol". and other resinous condensation products of phenol with formaldehyde; it is necessary

 <Desc / Clms Page number 3>

 also include varnishes based on polyhydric alcohol and polybasic acid resins formed by heating a polyhydric alcohol and polybasic acid resin, prepared in advance, with the desired oil or oils according to the usual methods of preparing varnishes.



   The term "non-pyroxylin coating" does not include coatings which contain nitrocellulose.



   By the expression "ratio of pigment to binder" is meant a ratio in which the expression "pigment" includes all the pigments and "fillers" or fillers, while the expression "binder" includes all the pigments. non-volatile constituents of the "vehicle", such as oil, resin based on polyhydric alcohols and polybasic acids, natural resin, drier and plasticizer, the ratio being expressed by weight.



   By "oil content" is meant the number of liters of oil per 100 kg of gum, when referring to oily type vehicles, and the percentage of oil in the reaction product when this refers to resins based on polyhydric alcohols and polybasic acids.



   By “oil units” is meant the number of parts by weight of oil present in the composition, relative to 100 parts of pigments.



   It has been discovered, however, that it is possible to shorten the drying times of underlay systems by first drying the primer coat and then drying all the primer coats simultaneously in one. second drying operation, provided that the primer coats have the characteristics indicated below.



   It has also been found that it is possible to apply all the coats of the underlayment system at a rapid rate, without intermediate baking, and to dry.

 <Desc / Clms Page number 4>

 then all these layers in a single operation, provided certain precautions are taken which are described in detail below.



   The object of the invention is therefore in particular to obtain the following results: a) to produce compositions for coatings which set rapidly when they are applied in thick films; b) to produce sub-layer systems in which it is possible to apply several layers one after the other without intermediate drying and to dry them in a single operation; c) to use this property in particular for all the layers of the underlay system, all these layers being dried in a single baking or a single air drying; d) to realize a system of undercoats for cars, mobile in which it is possible to carry out the entire application and the drying of the system in a time not exceeding three hours at a temperature of 71 0 approximately, or an equivalent time at a different temperature;

   (e) to establish a method of adjustment for the manufacture of the compositions for plasters and of the undercoat systems making it possible to obtain, by a single rapid drying in air or by steaming, a film having the desired characteristics of flexibility, adhesion, sanding, texture, toughness, hardness, thickness, good filling, minimum porosity, no pitting, no peeling, no blisters, no softening and non-disgorging.



   In order to obtain these different results, a few embodiments of sublayers according to the invention have been described below and which, of course, should not be considered as limiting the latter; figures given represent parts by weight.

 <Desc / Clms Page number 5>

 
 EMI5.1
 RESINOUS BIB3TS BASED ON POLYFLYDRIFIED ALCOHOLS AND POT ACIDS; TBASI QUE '. 3. -
 EMI5.2
 EXSMEM 1 ZZ2MBLf 2.-
 EMI5.3
 
<tb> Type <SEP> has <SEP> the oxide <SEP> Type <SEP> gray.
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>



  Ingredients. <SEP> -
<tb>
<tb>
<tb>
<tb> Pigments
<tb>
<tb>
<tb>
<tb>
<tb> Oxide <SEP> of <SEP> iron <SEP> 20.58
<tb>
<tb>
<tb>
<tb>
<tb> Smoke <SEP> black <SEP> <SEP> 3.48 <SEP> - <SEP>
<tb>
<tb>
<tb>
<tb>
<tb> Asbestine <SEP> 4. <SEP> 35 <SEP> 9. <SEP> 84
<tb>
<tb>
<tb>
<tb> Kaolin <SEP> 10.88 <SEP> 4.64
<tb>
<tb>
<tb>
<tb>
<tb> White <SEP> fixed <SEP> 4.36 <SEP> -
<tb>
<tb>
<tb>
<tb>
<tb> Litharge <SEP> 0.85
<tb>
<tb>
<tb>
<tb>
<tb> Lithopone <SEP> - <SEP> Il.62
<tb>
<tb>
<tb>
<tb>
<tb> Carbon <SEP> block <SEP> (black <SEP> of <SEP> gas) - <SEP> 0,

  he
<tb>
<tb>
<tb>
<tb>
<tb> Barite <SEP> <SEP> <SEP> <SEP> - <SEP> 17.25
<tb>
<tb>
<tb>
<tb> Silica <SEP> - <SEP> 8.71
<tb>
<tb>
<tb>
<tb>
<tb> Vehicle <SEP> not <SEP> volatile
<tb>
 
 EMI5.4
 Polyhydric alcohol resin z
 EMI5.5
 
<tb> and <SEP> of polybasic <SEP> acids <SEP> 10.83 <SEP> -
<tb>
<tb>
<tb> Resin <SEP> C <SEP> to <SEP> base <SEP> of alcohols <SEP> polyhy-
<tb>
<tb>
<tb> drics <SEP> and <SEP> of polybasic <SEP> acids <SEP> - <SEP> 10.70
<tb>
<tb>
<tb> Gum-ether <SEP> 2.13
<tb>
<tb>
<tb> Phthalate <SEP> dibntyric <SEP> 0.53 <SEP> 0.95
<tb>
<tb>
<tb> Drying agent <SEP> - <SEP> 0.35
<tb>
<tb>
<tb> Special <SEP> ingredient
<tb>
<tb>
<tb> Eugenol <SEP> - <SEP> 0.054
<tb>
<tb>
<tb> Solvents
<tb>
 
 EMI5.6
 Naphte à point d'dolair.élavd (bouil-
 EMI5.7
 
<tb> lant <SEP> between <SEP> 140 * 0. and <SEP> 190 C.

   <SEP> approximately) <SEP> 89.10 <SEP> 31.596
<tb> Essences <SEP> mineral <SEP> boiling <SEP> between
<tb> 136 <SEP> and <SEP> 2070 <SEP> C. <SEP> approximately. <SEP> 12.97 <SEP> 4.18
<tb>
<tb> Total <SEP> 100.00 <SEP> 100.00
<tb>
 
 EMI5.8
 UDity: 1 of oil absorption of
 EMI5.9
 
<tb> <SEP> combination of <SEP> pigments <SEP> 34.01 <SEP> 20.25
<tb> Ratio <SEP>, <SEP> oil absorption units <SEP>
<tb> oil <SEP> units <SEP> 100 / 22.2 <SEP> 100 / 48.5
<tb>
   OILY-TYPE PREPARATIONS.
 EMI5.10
 EXAMPLE 3. EXAMPLE Phew.
 EMI5.11
 
<tb>



  Type <SEP> to <SEP> the oxide. <SEP> Type <SEP> gray.
<tb>
<tb>
<tb>
<tb>
<tb>



  Ingredients.-
<tb>
<tb>
<tb> Pigments
<tb>
<tb>
<tb> Oxide <SEP> of <SEP> iron <SEP> 11.88
<tb>
<tb>
<tb> Lithopone <SEP> - <SEP> 11.87
<tb>
<tb>
<tb> Carbon <SEP> blook <SEP> 0.79 <SEP> 0.10
<tb>
<tb>
<tb> White <SEP> of <SEP> barite <SEP> 15. <SEP> 79 <SEP> 15.92
<tb>
<tb>
<tb> White <SEP> from Spain <SEP> 38.75 <SEP> 39. <SEP> 80
<tb>
<tb>
<tb> Vehicle <SEP> not <SEP> volatile
<tb>
<tb>
<tb> Varnish <SEP> to <SEP> base <SEP> of <SEP> 200.352 <SEP> liters
<tb>
 
 EMI5.12
 ghinhail wood dthai.
 EMI5.13
 
<tb> of <SEP> lin <SEP> for <SEP> 100 <SEP> Kgs <SEP> of <SEP> eraser.

   <SEP> 8.35 <SEP> 8.41
<tb> Drying agent <SEP> 0.22 <SEP> 0.22
<tb> Special <SEP> ingredient
<tb> pitch <SEP> of <SEP> stearin <SEP> 0.30 <SEP> 0.41
<tb> Solvents
<tb> Petrol <SEP> mineral <SEP> (see <SEP> ex.1) <SEP> 14.66 <SEP> 15.44
<tb> Xylene <SEP> 9.26 <SEP> 7.83
<tb>
<tb> Total <SEP> 100.00 <SEP> 100.00
<tb>
<tb> Uses <SEP> of absorption <SEP> of oil <SEP> of <SEP> the
<tb> <SEP> combination of <SEP> pigments <SEP> 17.03 <SEP> 16.44
<tb> Report: <SEP> oil absorption <SEP> units <SEP>
<tb>
 
 EMI5.14
 hail units. 1004fi, 4100/49.

 <Desc / Clms Page number 6>

 
 EMI6.1
 LL'M 4a, Varnish at. Amberol
Gray typa.
 EMI6.2
 



  In gradients.-
 EMI6.3
 
<tb> Pigments
<tb> Asbestine <SEP> 11.80
<tb> Kaolin <SEP> 5.89
<tb> Lithopone <SEP> 13.24
<tb> Carbon <SEP> blook <SEP> 0.122
<tb> Barite <SEP> <SEP> <SEP> <SEP> 19.67
<tb> Silica <SEP> 9.93
<tb> Vehicle <SEP> not <SEP> volatile
<tb> Varnish <SEP> to <SEP> base <SEP> of <SEP> 176.96 <SEP> liters
China <SEP> wood <SEP> <SEP> oil <tb>, <SEP> for
<tb> 100 <SEP> Kgs <SEP> of Amberol <SEP> containing <SEP> of
<tb> siccative <SEP> with <SEP> lead <SEP> and <SEP> manganese <SEP> 10.

   <SEP> 54
<tb> Special <SEP> ingredient
<tb>
 
 EMI6.4
 1-Oxy-2-mathomy-4 methyl benzene 0.008
 EMI6.5
 
<tb> Solvents
<tb>
 
 EMI6.6
 Mineral spirits (see example 1) aO.00
 EMI6.7
 
<tb> Xylene <SEP> 10.00
<tb>
<tb> Total <SEP> 100.00
<tb>
<tb>
<tb>
<tb>
<tb> Oil <SEP> <SEP> absorption <SEP> units of
<tb>
<tb>
<tb> the <SEP> combination <SEP> of <SEP> pigmenta <SEP> 20.25
<tb>
<tb>
<tb> Report:

   <SEP> oil absorption <SEP> units <SEP>
<tb>
<tb>
<tb> oil <SEP> units <SEP> 100 / 52.4
<tb>
   As an example of suitable primer and sealants for use with these new primers, especially in the single bake process, or in processes in which all of the primers are baked simultaneously, we have indicated the following
PRINT LAYERS
 EMI6.8
 EXEMPU 5. BXEMEEE 6.
 EMI6.9
 
<tb>



  Type <SEP> to. <SEP> oxida
<tb>
<tb> Resin <SEP> to. <SEP> base <SEP> of al- <SEP> Type <SEP> hui-
<tb>
 
 EMI6.10
 polyhydric and leux cools
 EMI6.11
 
<tb> polybasic <SEP> acids. <SEP> the oxide.
<tb>
 
 EMI6.12
 In edients, -
 EMI6.13
 
<tb> Pigments
<tb>
<tb>
<tb>
<tb> Oxide <SEP> of <SEP> iron <SEP> 8.22 <SEP> 7.69
<tb>
<tb>
<tb>
<tb> Smoke <SEP> black <SEP> <SEP> 1.59 <SEP> 3.03
<tb>
<tb>
<tb>
<tb> Asbestine <SEP> 3.78 <SEP> 3.47
<tb>
<tb>
<tb>
<tb> Kaolin <SEP> 4.73 <SEP> 4.46
<tb>
<tb>
<tb>
<tb> Talc <SEP> 3.78 <SEP> 3.64
<tb>
<tb>
<tb>
<tb> Litharge <SEP> 0.35 <SEP> -
<tb>
<tb>
<tb>
<tb> Vehicle <SEP> not <SEP> volatile
<tb>
<tb>
<tb>
<tb> Resin <SEP> B <SEP> to <SEP> baqe <SEP> of alcohols <SEP> polyhy-
<tb>
<tb>
<tb>
<tb>
<tb> drics <SEP> and <SEP> of polybasic <SEP> acids <SEP> 11.82 <SEP> -
<tb>
<tb>
<tb>
<tb>

  <SEP> to <SEP> base <SEP> of <SEP> 200,352 <SEP> liters
<tb>
<tb>
<tb>
<tb> oil <SEP> from <SEP> wood <SEP> from <SEP> China <SEP> - <SEP> huila
<tb>
<tb>
<tb>
<tb>
<tb> of <SEP> lin <SEP> for <SEP> 100 <SEP> Kga <SEP> of <SEP> eraser.- <SEP> 12.40
<tb>
<tb>
<tb>
<tb> Drying agent <SEP> - <SEP> 0.21
<tb>
<tb>
<tb>
<tb> solvents
<tb>
<tb>
<tb>
<tb>
<tb> Naphtha <SEP> at <SEP> flash point <SEP>.

   <SEP> high (see
<tb>
<tb>
<tb>
<tb> ex.1) <SEP> 20.85 <SEP> - <SEP>
<tb>
<tb>
<tb>
<tb> <SEP> mineral essences <SEP> (see <SEP> ex.1) <SEP> 18.26 <SEP> 30.08
<tb>
<tb>
<tb>
<tb>
<tb> <SEP> essence of <SEP> turpentine <SEP> - <SEP> 6.97
<tb>
<tb>
<tb>
<tb> Toluene <SEP> 26.62 <SEP> 28.15
<tb>
<tb>
<tb>
<tb>
<tb> Total <SEP> 100.00 <SEP> 100.00
<tb>
<tb>
<tb>
<tb>
<tb> Oil absorption <SEP> <SEP> units <SEP> from <SEP> the
<tb>
<tb>
<tb>
<tb> <SEP> combination of <SEP> pigments <SEP> 36.9 <SEP>. <SEP> 43.77
<tb>
<tb>
<tb>
<tb>
<tb> Ratio <SEP>: <SEP> oil absorption <SEP> units <SEP>
<tb>
 
 EMI6.14
 '- # units u oos5. 100 / 84.1

 <Desc / Clms Page number 7>

 
 EMI7.1
 1 '"àmberol" varnish
 EMI7.2
 
<tb> Type <SEP> to <SEP> the oxide.
<tb>
 
 EMI7.3
 Ingredient.-
 EMI7.4
 
<tb> Pigments.
<tb>
<tb>



  Iron <SEP> oxide <SEP> <SEP> 7.69
<tb>
<tb> Smoke <SEP> black <SEP> <SEP> 3.03
<tb>
<tb> Asbestine <SEP> 3.47
<tb>
<tb> Kaolin <SEP> 4.46
<tb>
<tb> Talc <SEP> 3.54
<tb>
<tb> Non-volatile <SEP> vehicle '.
<tb>
<tb>



  <SEP> to <SEP> base <SEP> of <SEP> 176.96 <SEP> liters
<tb>
 
 EMI7.5
 of amber-Chinese wood oil per 100 Kas dtamberol
 EMI7.6
 
<tb> containing <SEP> a <SEP> siccative <SEP> to <SEP> lead
<tb>
<tb> and <SEP> manganese. <SEP> Il.94
<tb>
<tb> Special <SEP> ingredient
<tb>
 
 EMI7.7
 1 (Ozr 2-mtho $ t mthl benzene 0.007
 EMI7.8
 
<tb> Solvents
<tb>
<tb> <SEP> mineral essences <SEP> (see <SEP> ex.1) <SEP> 37.713
<tb>
<tb> Toluene <SEP> 28.15
<tb>
<tb> Total <SEP> 100.00
<tb>
<tb> Oil <SEP> absorption <SEP> units <SEP> of
<tb>
<tb> the <SEP> combination <SEP> of the <SEP> pigments <SEP> 43.77
<tb>
<tb> Report <SEP>:

   <SEP> oil absorption <SEP> units <SEP>
<tb>
 
 EMI7.9
 oil units 100 / 73.6 RESIN SEALANTS BASED ON POLYHYDRIC ALCOHOLS AND
 EMI7.10
 OF POLYB! 8IC ACIDS.-
 EMI7.11
 
<tb> Example <SEP> 7. <SEP> Example <SEP> 8.
<tb>
<tb>
<tb>
<tb>



  Type <SEP> to <SEP> the oxide <SEP> ap- <SEP> Type <SEP> gray <SEP> ap-
<tb>
<tb>
<tb>
<tb> foldable <SEP> with <SEP> knife. <SEP> foldable <SEP> to
<tb>
<tb>
<tb>
<tb> knife.
<tb>
<tb>
<tb>
<tb>
<tb>



  Ingredients.-
<tb>
<tb>
<tb>
<tb>
<tb> Pigments
<tb>
<tb>
<tb>
<tb>
<tb> Oxide <SEP> of <SEP> iron <SEP> 25.33 <SEP> -
<tb>
<tb>
<tb>
<tb> Smoke <SEP> black <SEP> <SEP> 2.85 <SEP> -
<tb>
<tb>
<tb>
<tb>
<tb> Asbestine <SEP> 5.12 <SEP> 12.23
<tb>
<tb>
<tb>
<tb>
<tb> Kaolin <SEP> 12.76 <SEP> 5.76
<tb>
<tb>
<tb>
<tb>
<tb> White <SEP> fixed <SEP> 5.12 <SEP> -
<tb>
<tb>
<tb>
<tb>
<tb> Litharge <SEP> 1.02 <SEP> -
<tb>
<tb>
<tb>
<tb> Lithopone <SEP> - <SEP> 14.35
<tb>
<tb>
<tb>
<tb>
<tb> Carbon <SEP> blook <SEP> - <SEP> 0.14
<tb>
<tb>
<tb>
<tb>
<tb> Barite <SEP> <SEP> blank <SEP> - <SEP> 21.43
<tb>
<tb>
<tb>
<tb> Silica <SEP> - <SEP> 10.75
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> non-volatile <SEP> vehicle
<tb>
<tb>
<tb>
<tb> Resin <SEP> A <SEP> of alcohols <SEP> polyhydri-
<tb>
<tb>
<tb>
<tb>
<tb> ques <SEP> and <SEP> of acids <SEP>

  polybasic <SEP> 12.79 <SEP> -
<tb>
<tb>
<tb>
<tb>
<tb> Resin <SEP> 0 <SEP> of alcohols <SEP> polyhydri-
<tb>
<tb>
<tb>
<tb>
<tb> ques <SEP> and <SEP> of polybasic <SEP> acids <SEP> - <SEP> 13.30
<tb>
<tb>
<tb>
<tb> Gum-ether <SEP> 2.56 <SEP> -
<tb>
 
 EMI7.12
 Dibatyl phthalate 0.64 1; 17
 EMI7.13
 
<tb> Drying agent <SEP> - <SEP> 0.42
<tb>
<tb> Special <SEP> ingredient
<tb>
<tb> Eugenol <SEP> - <SEP> 0.066
<tb>
<tb> Solvents
<tb>
 
 EMI7.14
 Naphtha at the point of high oiliness
 EMI7.15
 
<tb> (see <SEP> ex. <SEP> 1) <SEP> 29.25 <SEP> 20.384
<tb> <SEP> mineral species <SEP> (see <SEP> ex.1) <SEP> 2.56 <SEP> -
<tb>
<tb> Total <SEP>] 00.00 <SEP> 100.00
<tb> Unit <SEP> of absorption <SEP> of oil <SEP> of <SEP> the
<tb> <SEP> combination of <SEP> pigments <SEP> 34.01 <SEP> 20.25
<tb>
 
 EMI7.16
 Report :

   oil absorption units OOf bzz.5 1 ------- = oil line lou / za 100 / 48.5

 <Desc / Clms Page number 8>

   OILY TYPE SEALANTS.
 EMI8.1
 



  EXEM1? LE 9 EXEMED 10 EXEMP 11 EXEMJ? LE 12 Type to Type Gray Type Gray Type
 EMI8.2
 
<tb> oxide <SEP> oxide <SEP> applicable <SEP> applicable
<tb>
 
 EMI8.3
 applica- applicable by spray- at the cou- ble by at. water supply. sprayed water. (as ex-
 EMI8.4
 
<tb> tion <SEP> (com <SEP> ample <SEP> 4).
<tb> me <SEP> ex.3).
<tb>
<tb>



  Ingredient
<tb> Pigments
<tb> Oxide <SEP> of <SEP> iron <SEP> 11.88 <SEP> 13.68 <SEP> - <SEP> - <SEP>
<tb> Lithopone <SEP> - <SEP> - <SEP> 11.87 <SEP> 13.62
<tb> Carbon <SEP> block <SEP> 0.79 <SEP> 0.91 <SEP> 0.10 <SEP> 0.12
<tb> Barite <SEP> <SEP> white <SEP> 15.79 <SEP> 18.25 <SEP> 15.92 <SEP> 18.30
<tb> White <SEP> from Spain <SEP> 38.75 <SEP> 44.66 <SEP> 39.80 <SEP> 45.69
<tb> Vehicle <SEP> my-volatile
<tb> Varnish <SEP> to <SEP> base <SEP> of
<tb> 200,352 <SEP> liters
<tb> of <SEP> wood oil <SEP>
China-oil <tb> <SEP>
<tb> from <SEP> lin <SEP> for <SEP> 100
<tb>
 
 EMI8.5
 Kgs of gum. 8.3ari 8.69 8.41 8169 Drying agent 0, aa z3 0, & a 0.23 Special ingredient Stearin wood 0.30 olza Oè4l O.S3
 EMI8.6
 
<tb> Solvents
<tb> Essences <SEP> mineral
<tb>
<tb> them (see <SEP> ex.1). <SEP> 14.

   <SEP> 66 <SEP> 13.35 <SEP> 15.44 <SEP> 13.12
<tb>
 
 EMI8.7
 Xylene 9.86 - 7.83 - Total 0. 100.00 100.00 100.00
 EMI8.8
 
<tb> Absorption <SEP> units
<tb>
<tb> oil <SEP> from <SEP> the
<tb> <SEP> combination of
<tb>
<tb> pigments <SEP> 17.03 <SEP> 17.03 <SEP> 16.44 <SEP> 16.44
<tb>
 
 EMI8.9
 Ratio: oil absorption units =
 EMI8.10
 
<tb> oil <SEP> units
<tb> 100 / 47.4 <SEP> 100 / 47.4 <SEP> 100 / 49.1 <SEP> 100 / 49.1
<tb>
 
The resins referred to above were obtained by heating together the following ingredients, in the proportions (parts by weight) shown, until the acid numbers were as shown.
 EMI8.11
 
<tb>



  Ingredients <SEP> Resin <SEP> A <SEP> Resin <SEP> B <SEP> Resin <SEP> C
<tb>
<tb> Glycerin <SEP> 23.1 <SEP> 19. <SEP> 3 <SEP> 16.72
<tb> Linseed <SEP> oil <SEP> <SEP> 30.8 <SEP> 29.6 <SEP> Phthalic anhydride <SEP> <SEP> 46.1 <SEP> 37.6 <SEP> 26.91
<tb> Huila <SEP> from <SEP> wood <SEP> from <SEP> China <SEP> - <SEP> 13.5 <SEP> Resin <SEP> - <SEP> - <SEP> 18.17
<tb> Oil <SEP> <SEP> acids from <SEP> wood
<tb> from <SEP> China. <SEP> - <SEP> 38.20
<tb>
 
 EMI8.12
 Total 100. uu 100.

   uu 100.00
 EMI8.13
 
<tb> Digit <SEP> of <SEP> acid <SEP> 52 <SEP> 30 <SEP> 20
<tb>
 However, it has been found that in order to manufacture the
 EMI8.14
 resin 0, it is good to increase the glycerin and the phthalic anhydride until a resin is obtained.

 <Desc / Clms Page number 9>

 homogeneous, then add the resin, and finally add the acids of Chinese wood oil and heat until the desired acid number is obtained.



   In the above examples, the vehicle used in the oily type compositions can be made with any of the ordinary varnish gums, in combination with China wood oil and linseed oil, provided that there is a preponderance of Chinese wood oil.



   In the above examples, the amounts of siccant indicated refer to amounts of a mixture of resinate and linoleate of lead and manganese, this mixture containing 14% lead and 4.5 d of manganese.



   Examples of coating systems in accordance with the invention are given below.



   SYSTEMS INCLUDING ALCOHOL-BASED RESINS
POLYHYDRICS AND ACIDS: POLYBASICS.



    EXAMPLE 13
Oxide products
The printing layer of Example 5.



   The putty of Example 7.



   The primer of example 1.



     EXAMPLE 14
Oxide products and gray products.



   The printing layer of Example 5.



   The putty of Example 8.



   The primer of example 2.



     OILY TYPE SYSTEMS.-
EXAMPLE 15
Oxide products
The printing layer of Example 6.



   The putty of Example 9.



   The primer of example 3.



   EXAMPLE 16.



   Oxide products and gray products.



   The printing layer of Example 6.



   The putty of Example 11.



   The primer of example 4.



   EXAMPLE 16-A
Produces oxide and gray products.



   The printing layer of Example 6a.



   The mastic of Example 4a.



   The primer of Example 4a.

 <Desc / Clms Page number 10>

 



   MIXED SYSTEMS.-
EXAMPLE 17: Oxide products.



   The printing layer of Example 5.



   The putty of Example 10.



   The primer of example 3.



   EXAMPLE 18
Produced with oxide and gray products.



   The printing layer of Example 6.



   The putty of Example 8.



   The primer of example 2.



   As indicated by the preceding examples, the advantages of the invention can be obtained, either by systems of the resinous type based on polyhydric alcohols and polybasic acids, or by systems of the oily type or combinations thereof. systems, and sealants and primers can be of various types, such as oxide plasters or gray plasters. However, due to the rapid drying of the resin primers of polyhydric alcohols and polybasic acids, it is not practical to apply these primers to oily type primer coats unless the latter are are not dried beforehand.



   Although in all of the above-described systems there has been talk of a mastic filler, it should be understood that the mastic filler can be omitted from any of the above-mentioned systems and from all of the above. systems coming within the scope of the invention, provided that the surface to which the underlayment system is to be applied is sufficiently smooth so that it is superfluous to apply a mastic coating to fill the irises. regularities of the surface, or when the conditions required for the quality of the finished product do not correspond to optimum results.

   It should also be understood that the mastic may be of a consistency suitable for application with a knife, as indicated by the systems of Examples 7,8 and 10, used in the combinations of Examples 13, 14 and 17 above, or. well can be diluted with volatile solvents, such as those indicated below.

 <Desc / Clms Page number 11>

 above, to allow it to be applied by spraying. In practice, however, it has been found convenient and satisfactory to employ also the undiluted primers as spray-applied sealants, as indicated by the compositions of Examples 9 and 11, used in the systems of Examples 15 and 15. 16 above.



   Although the specific characteristics needed in a system. undercoats vary with the particular product to be painted and with the arbitrary reception conditions which have been set, it can be said that in general the characteristics of systems of this type, in particular for automobile bodies, are substantially the following.



     Plexibility and adhesion.- The different couohas must adhere to each other, and all the layers must adhere to the metal and not come off in large pieces but must tend to be scraped off in the form of a tape. In other words, the product should have a clear tendency to "lend itself" like soap, when cut with a knife, and not have a tendency to shatter and no cracking or chapping should occur. under normal exposure conditions.



   Toughness .-- When a knife is pulled across the surface, so as to produce a scraping effect, the film should not break off into pieces or become chalky.



     Hardness.- The film must have considerable resistance to penetration or abrasions to the usual test with the fingernail, in order to resist sanding and to be hard throughout its thickness.



     Sanding - In wet sanding operations, the composition must not clog the sandpaper, it must not sand too hard or too much

 <Desc / Clms Page number 12>

 slowly and it should not "hold" too much, that is, have too much of a tendency to pull the sandpaper out of the operator's hand.



   Texture, - The film must be sufficiently free of hard grains so that no harmful abrasions occur during sanding and to prevent small hard particles from being dislodged, which would produce debuts on the surface.



   Minimum porosity. - The porosity (the film must not exceed a certain limit, so as not to exert an absorption effect (like a blotter) too exaggerated when applying the superficial layers and thus pocket a penetration In practice, speaking of the non-porosity of the base coats, it is said that they "hold" to the color coat.



   Pitting.- The film must not show pitting, that is, very small pits which, in the color layer, give the appearance of needle holes.



   Lifting.- The film must not separate and wrinkle or form sinuosities on the surface, or cause pinholes when applying the top coats.



   Bulbs. - The film must not form blisters or blisters during the application of the superficial coats due to the local evolution of gas from the primer system.



   Bevel Cut.- The film should be properly beveled, that is, when the operator makes a cut in the separated layers, a sawtooth appearance of the edges should not occur. adjacent layers thus laid bare.



   Softening.- The pellioule must not soften or form a paste under the action of water, during

 <Desc / Clms Page number 13>

 sanding operations, and must not be quickly softened by the diluting action of petroleum.



     Thick Sure.- The film should dry properly in thick layers, such as those needed to fill abrasions or other irregularities in the surface to which the film is applied, and it should give a smooth surface when sanding.



   Drying .-- The film must dry throughout its mass instead of being soft at the bottom and hard on the surface, which is known as surface hardening, and it must dry with sufficient speed and uniformity, so as not to not to undergo in the exposure to normal weathering, subsequent drying with bulk reduction, which would lead to defects such as chapping and cracking.



     Non-bleeding.-The ingredients of the basecoats should not be absorbed by the colorcoat, which will damage the tint and other qualities of the latter.



   Thanks to the invention, all of the above characteristics can be obtained, and in addition the special feature of allowing adequate drying of all the base coats in a single, short-term stoving phase, that is, that is to say in a single oven passage not exceeding three hours at approximately 71 C., or an equivalent period at different temperatures. The five typical systems given in Examples 13 to 17 meet all these conditions and, when they have been applied with a single primer coat, a single coat of mastic and one, two or three coats of primer. , they produced satisfactory dandruff when drying for two hours at 71 C.

   The typical combination given in example 18 is not intended for drying in a single oven pass but is particularly suitable for double oven passage, in which the printing layer is

 <Desc / Clms Page number 14>

 steamed for 1 to 2 hours at 710., while the mas- tic and two or three coats of primer were steamed for additional hours at 70 0.



   In practice, when all the basecoats are to be dried simultaneously, it has been found useful to allow the primer to sit for a period of 5 to 15 minutes to allow the solvents to evaporate, followed by the sealant. is applied with a knife or spray, if one coat of putty is used, and the desired number of coats of primer are applied immediately, preferably by spraying, without waiting for intermediate drying, at least at least more than 10 minutes between these coats to allow the partial evaporation of the solvents. The whole is then dried in an oven for a maximum of three hours at 71 ° C., or for an equivalent period at different temperatures.



   When there is no disadvantage in carrying out several drying operations, the procedure is preferably carried out in the same way, except that the printing layer is preferably first dried in an oven, for example during two hours at 71 C., and the mastic and primer coats are then applied and baked in a second step, for a period not exceeding three hours at 71 C., or an equivalent period at a different temperature .



   In practice, it has been found that the presence of a large amount of solvents facilitates leveling when a primer coat is being sprayed, and it is therefore common practice to dilute the composition. coated with varying amounts of solvents, depending on the viscosity desired for spraying. for example, the sizes given in Examples 3 and 4 spray better, as experience has shown, when diluted with 10% by volume mineral spirits.

 <Desc / Clms Page number 15>

 the particular finish compositions which can be used in the application of the invention can vary within fairly wide limits, namely;

   
The combinations of pigments both for the resinous type based on polyhydric alcohols and polybasic acids and for the oily type can vary from the point of view of their chemical composition and physical properties; a) Their chemical composition can be very variable with regard to the iron oxide content in oxide products. In gray products, lithopone can be replaced by titanium or lead pigments, and the latter can also vary within wide limits.

   Carbon black can be replaced by other blacks, such as carbon block and black known as "Keystone filler". fillers, such as asbestos, kaolin, fixed white, barite white, silica, Spanish white and talc can generally substitute for each other outside of the limitations specified herein Likewise, if desired, a buff-colored material can be prepared by using lithopone and a yellow pigment, eg ocher, in place of iron oxide.

   In the case of some resin = products based on polyhydric alcohols and polybasic acids containing vehicles with relatively high acid numbers, such as those with an acid number greater than 10 (calculated on the basis of solids in the non-volatile vehicle), and also in the case of certain oily type vehicles which tend to react with basic pigments, such as Congo resin and wood oil based varnishes.
China, there are examples where pigments, such as zinc oxide, Spanish white and lead carbonate, must be excluded, to avoid passage to

 <Desc / Clms Page number 16>

 the consistency of the liver,

   or thickening of the compositions in their containers during periods of storage before use. Generally, however, the invention is not limited to particular pigment combinations with regard to limitation of chemical compositions. b) Their physical properties: relatively high percentages of talc should be avoided in basecoat products used under pyroxylin-based topcoats, as otherwise there is a risk of sacrificing the good adhesion of the topcoats to the basecoat system. bottom layers.

   In addition, it has been observed that a predominance of hard fillers, such as barite white and silica, should usually be avoided in sealants and primers, except in the case of products. intended for stone sanding, due to the difficult sanding properties they give to the primer coats. Likewise, it is good to choose pigments and fillers of a relatively good texture or fineness, if, - no excessive and expensive grinding would have to be carried out to remove the hard grains which would produce harmful scratches on the surface during sanding. . pigments which bleed during the application of the surface layers should also be avoided.

   The degree of oil absorption of the pigment combination is of prime importance and is discussed in detail in the following paragraphs.



   : By "oil absorption" is meant the number of parts by weight of acid-refined linseed oil, having an acid number of 6 to 8, which are necessary to moisten 100 parts by weight of pigment and bring it to a determined consistency. The total number of oil absorption units for any given combination of pigments is determined directly, or by multiplying the weight of each pigment employed,

 <Desc / Clms Page number 17>

 expressed as a percentage of the total pigment combination, by its "oil uptake" and adding the results.



   For example, if this rule is applied to the pigment combination of the primer of Example 2, the total oil absorption of the pigment combination is achieved as follows:
 EMI17.1
 
<tb> Pigments <SEP> Weight <SEP>% <SEP> of <SEP> the <SEP> Absorption <SEP> Units <SEP> of ab-
<tb>
<tb>
<tb> Combination <SEP> to- <SEP> of oil <SEP> sorption
<tb>
<tb>
<tb> tale <SEP> of <SEP> pig- <SEP> of oil <SEP> <SEP> for
<tb>
<tb>
<tb> ments. <SEP> pigment, <SEP> the <SEP> quantity
<tb>
<tb>
<tb> of <SEP> pigment
<tb>
<tb> used.
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>



  Asbestine <SEP> 18.88 <SEP> 25.6 <SEP> 4.83
<tb>
<tb>
<tb> Kaolin <SEP> 8090 <SEP> 38.0 <SEP> 3.38
<tb>
<tb>
<tb> Lithopone <SEP> 22.26 <SEP> 17.0 <SEP> 3.78
<tb>
<tb>
<tb>
<tb> Carbon <SEP> blook <SEP> 0.21 <SEP> 129.9 <SEP> 0.27
<tb>
<tb>
<tb> Barite <SEP> <SEP> white <SEP> 33.05 <SEP> '11 .4 <SEP> 3.77
<tb>
<tb>
<tb> Silica <SEP> 16.78 <SEP> 25.3 <SEP> 4.22
<tb>
<tb>
<tb> 100.

   <SEP> 00 <SEP> 20.25
<tb>
 
Although various methods can be employed to determine the oil absorption by the pigments used, the results will vary with the method chosen and the figures given above are based on the following method, known as the "oil absorption method". spatula ", which was described in" The Paint, Oil & Chemisai Review "of. May 7, 1984 on page 10, and it is this method that we will preferably use:
5 grams of pigment are weighed out and spread on a finely ground glass plate to form a layer about 40 m / m wide and 75 to 100 m / m long.



  A 10 cc lunge-type pipette is filled almost completely with linseed oil and weighed. 20 drops of oil are added to one closed end of the pigment layer and mixed with a stiff spatula until a firm, putty-like paste forms. Add 5 drops of oil and incorporate them into the dough by gentle but firm pressure, until a soggy dough is obtained. The intact dry pigment is gradually added until the

 <Desc / Clms Page number 18>

 dough becomes firm again. Repeat until all of the dry pigment is incorporated into a firm, putty-like pellet, gradually reducing the amount of oil used. Another drop of oil is added and it is introduced into the dough.

   Collect all the dough in a ball and place it on the. blade of a spatula near the handle * The meatball is gently transferred onto a spatula with a blade of
6 m / m approximately by passing it under the meatball. We lower the end of the spatula and very gently throw the: dumpling. If no piece of dough sticks to the spatula, add another drop of oil and introduce it into the dumpling. Repeat until a little dough sticks to the spatula. The pipette is weighed again and the oil absorption expressed in grams of oil per 100 grams of pigment is calculated. All these operations are carried out under a relative humidity of 50% at 25 ° C., in a chamber of constant temperature and humidity.



   Grinding - It has also been noticed that the method and the degree of grinding of the compositions for basecoats have an important effect on the apparent oil absorption, i.e. the total initial oil absorption of the combination of pigments can be either slightly or significantly increased, depending on the method and degree of grinding chosen, the oil absorption increasing with the fineness of the grinding.



   The limits of the acceptable determined oil absorption values for the pigment compositions given above remain true regardless of the conditions of grinding, but the ratio of oil absorption units The oil units in the optimum product decreases as the grinding increases. Most of the experiences have been based on operations. curve grinding time with steel ball mill

 <Desc / Clms Page number 19>

 and experience has shown that the conditions for grinding are thus satisfactorily fulfilled.

   From the practical point of view, however, the grinding can be carried out in a steel ball mill, in a grinding mill, in a horizontal roller mill, in an apparatus for the preparation of colloidal solutions or other grinding equipment. usual. In the grinding of basecoat compositions, for most combinations of pigments, suitable gildings are for example, in the case of the steel ball mill, 6 hours with a load of two parts by weight of steel balls to one part by weight of material; a single pass through 75 cm grinders. diameter or more, or in a horizontal roller mill set up to achieve a corresponding degree of fineness.



   The resins based on polyhydric alcohols and polybasic acids used in the compositions indicated above can be replaced by other resins based on polyhydric alcohols and polybasic dibasic acids in which an amount of Sufficient oil is also chemically combined to give sufficient solubility and flexibility, without significantly delaying drying. For example, it has been found that the oil content can vary from 23 to 50% in the case of linseed oil and from 25 to 80% in the case of Chinese wood oil, based on the weight of the dry resin composition.

   Resins based on polyhydric alcohols and polybasic acids modified with natural gums, chemically combined with these resins to obtain satisfactory solubility, or resins based on polyhydric alcohols and acids can also be used. polybasic, modified by both gums and oils.



  Non-volatile vehicles used in products

 <Desc / Clms Page number 20>

 Oily type products may include any common natural gums, synthetic gums, such as gum ethers, or "Amberol" or resins based on polyhydric alcohols and polybasic acids constituting the compound. rubber of these vehicles. As suitable oils, Chinese wood oil, linseed oil, perilla oil, soybean oil, and fish oil can be used, although it is preferable to use a mixture of Chinese wood oil and linseed oil, the first being in a predominant quantity over the second.

   The presence of Chinese wood oil appears desirable, since such oil compositions appear to polymerize them at the expense of oxidation, and the polymerization promotes rapid drying of the resulting films. When linseed oil predominates over wood oil. China, it seems preferable to choose a vehicle containing less oil per 100 kg of rubber than in the case of the reverse category of vehicles. Perilla oil appears to behave quite like linseed oil. The use of soybean oil and fish oil gives generally less satisfactory results, although the quality of the resulting products does not exclude them from the scope of the invention.

   Any mixture of the oils listed above can be used depending on the drying rate and other desired characteristics. The non-volatile vehicle should contain at least 68.784 liters of oil per 100 kg of gum, but preferably it should contain at least 100.176 liters.



   The volatile solvents may vary in the same way in the different systems shown, but it is obvious that solvents whose evaporation rates are so slow that they would seriously oppose drying at moderate baking temperatures should not. be used in sufficient quantity to be harmful.

 <Desc / Clms Page number 21>

 



   High flash point naphtha (see ex. 1), high boiling point esters, turpentine, mineral spirits (see ex. 1) and toluene have been found to be desirable ingredients for resinous products based on polyhydric alcohols and polybasic dibasic acids, although high flash point naphtha and high boiling point esters are not required in oily type products. In the latter, mineral spirits, turpentine, xylene and toluene can be used separately or in various combinations, with satisfactory results, although turpentine is particularly useful when the product contains natural hard gums.

   Likewise, in resinous products based on polyhydric alcohols and polybasic acids, mineral spirits and toluene can be omitted and replaced by high flash point naphtha, high flash point esters. high boiling or turpentine, but it has been found that in general mixed solvents give better results, both for resinous products based on polyhydric alcohols and polybasic acids and for those of the oily type.



   Although the use of lead and manganese driers has been indicated in the products listed above, it should be understood that other well known suitable driers, such as cobalt driers, may be substituted for them and that small variations are allowed in the amounts of drier used, without significantly changing the drying conditions. In the case of products of the oily type, however, the optimum drying speed for the composition under consideration can only be obtained by introducing a sufficient quantity of drier into the composition.



     $ 8 if applicable, the compositions falling within the

 <Desc / Clms Page number 22>

 framework of the invention may contain protective agents of the taris type, such as eugenol, to prevent the. formation of harmful skin, stearin pitch, to prevent pigment from deleteriously settling, and litharge to improve the water resistance of certain resinous products based on polyhydric alcohols and polybasic acids. Likewise, plasticizers, such as dibutyl phthalate, can be used in resinous products based on polyhydric alcohols and polybasic acids.



   In all the systems coming within the scope of the invention, it should be understood that the surface or colored layers applied subsequently can be of any type, based on pyroxylin, oil or resin.



   It has been found that it is preferable to operate the drying at a low temperature, for example 71 ° C., but that, if temperatures of 93 or 1210 are not detrimental, drying for an hour and a half to 93 or one hour at 121 equals three hours drying at 71.



  For the sake of clarity, all the drying times have been reported at the temperature of 71. It has also been found that the primer system according to the invention assumes satisfactory hardness upon drying in air, i.e. at room temperatures from about 21 to 27, for 15 to 24 hours for. resinous compositions based on polyhydric alcohols and polybasic acids, and for 20 to 36 hours for oily and mixed-type systems.



   It should be noted that the rule for obtaining one-time drying basecoat systems lies in the formulation of the primer.



   The essential feature of the present invention is based on the discovery that therefore much shorter drying conditions are possible.

 <Desc / Clms Page number 23>

 Wheats for individual plasters and basecoat systems, as well as for drying several coats simultaneously, without sacrificing the desirable properties of such plasters or systems, by establishing a suitable relationship between the drying characteristics of the layer (s), and the flexibility and toughness of the resulting film, as well as the lifting characteristics of individual or collective stumps, as explained opposite.



   The mode of adjustment for the application of this and you discovered, and in particular for the production of oompositions of plasters which can be used in systems in which all the primer coats are dried simultaneously, or alternatively in which the entire coating system bottom is dried in one operation, is as follows;

   
Primers of resins based on polyhydric alcohols and polybasic acids., - It is necessary to establish the formula of these primers starting from the combinations of pigments whose total oil absorption units do not exceed 50, use a resin based on polyhydric alcohols and polybasic acids, the oil content of which does not drop below 23%, and to maintain a pigment to binder ratio high enough to prevent lifting when the surface layers are applied , but low enough to prevent excessive brittleness and lack of toughness. This ratio, expressed in oil absorption units divided by oil units, must be between 100: 15 and 100: 60.



     , Oily type primer.- The formula of these primers should be established starting from combinations of pigmenta whose total oil absorption units do not exceed 22, use a binder with a content of oil is not less than 66.789 liters of oil per 100 Kgs of gum, and maintain a pigment to binder ratio

 <Desc / Clms Page number 24>

 high enough to prevent lifting when the top layers are applied, and low enough to avoid deleterious brittleness and lack of toughness. This ratio, expressed in oil absorption units divided by oil units, must be between 100:40 and 100:70.



   It has been specified that combinations of pigments whose oil absorption units do not exceed 50 and 22 are satisfactory for resinous type finishes based on polyhydric alcohols and polybasic acids, and of the type oily, respectively, but, of course, it is preferable to employ, as indicated by the compositions of Examples 13 to 17, combinations of pigments whose oil absorption units are significantly less than 50 and 22, for resinous type finishes based on polyhydric alcohols and polybasic acids and oily type, respectively.



   It is obvious that, when the conditions of reception or specifications are less demanding on the quality than indicated above, or when there is no disadvantage to increase the drying time or to multiply the passages in the oven, greater variations in this adjustment mode are permitted.



   Print Coats. Although limits have been indicated for the maximum acceptable oil absorption of the combinations of pigments used in the composition of the primers. Within the scope of the invention, experience indicates that satisfactory print layer compositions can be formulated by choosing combinations of pigments having any oil absorption values within practical limits. primer pigment compositions, and formulating printhead compositions based on these data in general terms as for priming.

 <Desc / Clms Page number 25>

 



   This is especially true when the printing process is to be steamed independent of the primer coats and the entire basecoat system, including a relatively good primer, is to be oven dried in a single pass. . However, if an oily type primer is used which is very close to the limit ratios between oil absorption units and oil units, i.e. close to 100:40 or 100 70, the primer coat must be formulated with more care to allow it to be dried together with the primer coats, and in this case the primer coat must have a composition close to that given in Example 6 to obtain the best results.



   With regard to film quality, the best results are obtained with primer layer compositions having as low a ratio of "oil absorption units to oil units" as possible, without the need for all of the dried primer coats are lifted when the pyroxylin-based surface coats are applied.



   A special feature of resinous imprint coats based on polyhydric alcohols and polybasic acids is that they harden sufficiently to allow the application of a coating with a knife, as soon as the solvents are applied. have evaporated, which usually takes 5 to 15 minutes. On the other hand, if an oil-type printing layer, such as those given in Example 6, is used, it should be subjected to air drying for several hours or to short drying. an oven, for example for one hour at 71 C., before being able to apply a coating with a knife.



   Sealants.- Both resinous sealants based on polyhydric alcohols and polybasic acids, as well as

 <Desc / Clms Page number 26>

 Oil-type sealants, including those which contain "Amberol" varnishes as vehicles, are generally formulated as primers, except that they generally contain less solvent, but their composition may vary. vary as indicated in the previous discussion.



   When the words "film thickness" are used, this is the thickness of the entire basecoat system or the entire set of basecoats after drying and before sanding, resulting in the application of the desired number of coats without overlap (ie without going through the same place twice for a given coat).



   A particular characteristic of the invention resides in that, if one follows the indicated control mode, in the light of all the preceding description, it is possible to obtain satisfactory basecoat systems. doing so, by simultaneous oven drying of several layers the total thickness of which is at least 75 thousandths of a millimeter, which makes it possible to obtain great thicknesses at the same time as rapid drying conditions.



     However, it should be understood that the invention also relates to the manufacture of the single coats, when using the indicated control mode or when using compositions within the stated limits in basecoat systems, and that it also relates to the simultaneous drying of several coats without pyroxylin, which form a relatively thick film, regardless of whether or not these coats constitute the entire primer system.



   It appears from the foregoing that the invention makes it possible to obtain new and useful coating compositions and basecoat systems, forming

 <Desc / Clms Page number 27>

 films having all of the desirable qualities, that such compositions and coating systems can be dried in a much shorter time than prior compositions and systems, and that any or all of the desired basecoats can be applied. one after another without intermediate drying in the oven, and dried all together to obtain satisfactory hardness.
 EMI27.1
 



  RmVE1IDI - GAT l ON S. - The object of the invention is
1 .- A process for coating articles, such as automobile bodies, remarkable in particular by the following characteristics: a) It comprises the application of a certain number of layers of coating without pyrozyline, applied at a rapid rate and all dried simultaneously. b) These layers are dissimilar. c) They are applied to a printing layer previously dried in an oven. d) These layers comprise one or more layers of the oily type or else one or more layers of the resinous type based on polyhydric alcohols and polybasic acids. e) The different layers are dried in a single pass in an oven at 71 C. for a maximum of three hours.

   f) The total film thickness of the primer coats is at least 75 thousandths of a millimeter.

** ATTENTION ** end of DESC field can contain start of CLMS **.


    

Claims (1)

2 .- A process for obtaining compositions for products without pyroxylin and fast drying, remarkable in particular by the following characteristics: a) It consists in selecting combinations of pigments with low oil absorption and binders having <Desc / Clms Page number 28> tendency to polymerization, and to control the pigment to binder ratio so that the resulting composition, when applied in relatively thick films, dries in three hours at 71 ° C. b) A coating composition is prepared using pigments with total oil absorption units not exceeding 50, a resinous binder based on polyhydric alcohols and polybasic acids, of which the oil content is at least 23%, and using a pigment to binder ratio between 100: 15 and 100: 60 (expressed in oil absorption units divided by oil units.) c ) Pigments are used whose total oil absorption units do not exceed 22 and an oily type binder with an oil content of at least 66.784 liters, per 100 kg of gum, and a ratio is maintained from pigment to binder between 100: 40 and 100: 70 (expressed as above). d) These coating compositions can be used as primer coats on undried or previously oven-baked printing coats, and / or under surface layers based on pyroxylin. 3 .- A composition of plasters without pyroxyline, fast drying, remarkable in particular by the following characteristics: a) It comprises a combination of pigments with low oil absorption and a binder having a tendency to polymerization, the pigment to binder ratio being such that, when the coating composition is applied to an article in a relatively thick layer, it dries in three hours at 71 ° C. b) It is obtained by the process indicated in paragraph 2. 4 .- Articles coated using the process indicated EMI28.1 pac & grphe 1.