JPS585373A - Undercoating composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a basecoat composition for use in a process for applying protective and decorative coatings to the surfaces of substrates, in particular to the surfaces of motor vehicle bodies. It is well known to use coating compositions in which the so-called ``Glamourmetall 1'' finish is used.
There is a painting method called ``ic'' finisham).
According to this method, the reflection effect of light rays can be adjusted to angles different from [K] to the angle at which the painted object is viewed. This 1 flip”tone effect (-flip”tone @ff@ct
), it is necessary to carefully prepare the coating composition with respect to the film-forming resin and the liquid medium. It is commonly desired in the automotive industry to produce a final finish with a high gloss. To this end, one method that has been proposed for producing a metal finish is a two-layer coating method, in which the surface of the substrate is coated with
First, the optimal 1-flip product contains metal pigments.
A basecoat formulated to produce the desired effect is applied, and then an unpigmented finish coat is applied over the basecoat that produces the desired degree of gloss but does not alter the appearance of the basecoat.

An essential condition for a successful two-layer metal finishing process is that when the top coat is applied, it does not mix with the pre-applied F4 paint or, in some cases, significantly It should not show any significant solvent action. If this condition is not fully met, the metal coloring effect will be significantly impaired.In principle, this condition requires the use of mutually immiscible film-forming materials for both the base coat and the top coat. K may be more satisfactory, but in this case the necessary adhesion between the two coatings would not be obtained. A more practical method for satisfying the above conditions is to use a thermosetting resin as the base coat and to cure the base coat for a short time before applying the finish coat; This has the disadvantage that if the spraying operation is interrupted due to operation, the coating process becomes complicated. A preferred aspect of painting is that the base coat dries in a few minutes under normal spraying conditions to such an extent that it will not be affected by the finish coat applied to the base coat.

A method proposed to achieve the above objectives for automotive dual-layer metal finishes based on solutions of acrylic polymers in volatile organic solvents is to use cellulose esters, e.g. vinegar, as the base coat. In this method, a colored acrylic polymer solution containing cellulose butyrate is used, and an uncolored solution of a specific crosslinkable acrylic copolymer and a crosslinking agent for the copolymer is used as the top coating. A base coat is applied to the substrate, a finish coat is applied without intermediate baking of the base coat, and finally baking is performed to harden the finish coat.

Recently, the present inventor has discovered that when a certain proportion of insoluble polymer fine particles are mixed into the polymer present in the undercoat paint, the application of the transparent finish paint to the colored undercoat paint during two-layer finishing can be improved. A friend discovered that it can be done successfully without performing the burning operation.

According to the invention, the following ingredients are present: (4) the polyester resin is a film-forming polymer other than an alkyd resin; (B) a volatile organic liquid diluent that dissolves said polymer; r) said film-forming polymer. An amount of 15-86 based on the total weight of the polymer particles and the lower polymer particles is not dissolved in the solution consisting of the film-forming polymer and the diluent, but is stably dispersed in the solution. and (b) 2 to 100 particles based on the total weight of the film-forming polymer dispersed in a solution consisting of the above film-forming polymer and a diluent.
pigment particles in an amount of pigment particles; ) How to form a decorative multilayer coating.

(a) Applying the undercoat composition of the present invention to the surface of the substrate; (
b) applying the polymer film from the composition applied in step 1 (a) to the surface of the substrate; ) applying a clear topcoat composition comprising a liquid to the volatile resin for said polymer; It consists of jin which forms .

The film-forming polymer component of the base coating composition of the present invention used in the above-mentioned process is found to be useful in the production of coating compositions, excluding polyester resins and aluminum resins. One class of e-suitable polymers, which may be any of the known polymers, consists of polymers that can be derived from one or more ethylenically unsaturated monomers. Among this class of polymers, useful in 4IK are the acrylic addition polymers widely used in the automotive industry to produce coatings, i.e. one of the alkyl esters of acrylic acid or methacrylic acid or More than that,
Optionally, the polymers of these and other ethylenically unsaturated monomers are copolymers. 〉obtain/any of the above □ types of polymers/) are suitable a! Acrylic esters include methyl methacrylate, methyl methacrylate, butyl methacrylate, butyl methacrylate, ethyl acrylate, butyl acrylate, and 2-ethyl acrylate; and other suitable copolymerizable materials. The monomers are vinyl acetate and vinyl pionate.

Proviso: If the polymer needs to be cross-linked, appropriate functional monomers should be used in addition to the latter monomers mentioned above. Is acrylic acid, methacrylic acid, Nido I211? Diethyl acrylate, human gastric xyethyl methacrylate, 2-human W-misobu tetravir acrylate, 2-human rexib! Virumethatalylate, N-(alkoxymethyl)
Primer coatings including acrylic diamide and N-(AJ&;'':1o dimethyl) methacrylate (wherein the Al:I group can be substituted with, for example, a buto-dimethyl) group, dalysilyl acrylate and dalyV-lyl methacrylate. In such cases, the composition comprises a lysocyanate, lye dI acid or especially a nitrogen-containing resin, i.e. formaldehy Y;
Condensates with nitrogen-containing compounds such as urea, thiourea, melamine or zoguachan, or lower alkyl ethers of such condensates (the alkyl group has 1 to 4 carbon atoms)
For the purpose of the present invention, a suitable crosslinking agent is a melamine-formaldehyde condensate in which a substantial proportion of the methylol groups have been dietherized by reaction with butanol. It is believed that the crosslinking agent, if present, becomes part of the film-forming polymer matrix. Appropriate catalysts may be included, such as acidic compounds such as acidic butyl maleate, acidic butyl maleate, t*tip-toluenesulfonic acid. Alternatively, catalysis can be achieved by introducing free acid groups into the acrylic polymer, for example by using acrylic acid or methacrylic acid as a comonomer in making the polymer. can be done.

Acrylic polymers can be produced by solution polymerizing monomers in the presence of an organic peroxide or an azo compound such as a catalyst such as peroxide, acylisobutylene and tolyl, or a polymerization initiator. The diluent reaction can be conveniently carried out in the same organic liquid as that forming the diluent component of the basecoat composition.Alternatively, the acrylic The polymer is prepared in a separate reserve 1
Other suitable polymers derived from ethylenically unsaturated monomers can be prepared by dissolving them in a suitable organic liquid. Vinyl copolymers, i.e. copolymers of vinyl esters of inorganic or organic acids, such as vinyl chloride, vinyl acetate or vinyl tetrapionate. Arsul units may be introduced. An example of such a copolymer is a copolymer containing 91 parts by weight of vinyl chloride, 6 parts by weight of vinyl acetate, and UHlon Carisld*C.
1 bit tool light from orporatlem” (-Vin
ylit@') Sold under the product name of VAGif.
Polymer derived from ethylenically unsaturated monomer tJ base b
The polymeric component of the basecoat composition can be a cellulose ester, such as acetate butyrate or nitrate. 41 K%Iastmn KAB from Koik
Sold under the trade name 551-1, it has an acetyl group content of 5III, a butyryl group content of 50, and 8TMD.
-1343154TK Therefore, an acetate butyrate cellulose having a measured viscosity of 1-2 seconds is suitable.

Yet another type of polymer that can be used as a component (as a component) is already mentioned in the discussion of crosslinking agents for thermosetting Acrylic II11 polymers and is a nitrogen-containing resin. It can be used as a material, but it is good for this @ target! The new resin is likewise a meladen-formaldecondensate in which a substantial proportion of the methyl groups have been etherified by reaction with butanol.

In order to accelerate the curing of the resin, it would be preferable to add a catalyst, for example, to the lower IklIl composition.
A mixture of a thermosetting acrylic polymer and a nitrogen-containing resin is used in such proportions that the latter -Il acts as a crosslinking agent and a portion acts by its nature as a supplementary film-forming agent. It will be clear that the volatile organic liquid component of the basecoat composition of the present invention is obtained.

Any liquid or mixture thereof which is conveniently used as a solvent for the polymer in the coating composition, for example aliphatic hydrocarbons such as hexane and heptane, aromatic hydrocarbons such as toluene and xylene, various boiling point ranges. and consisting primarily of aliphatic components but containing an amount of aromatic components, esters such as butyl acetate, ethylene glycol-luriacetate and 2-ethyl acetate, acetone and methyl Ketones, such as isobutyl ketone, and alcohols, such as butyl alcohol. In accordance with principles well known in the coatings art, the amount of polymeric particles present in the basecoat composition of the present invention will vary depending on the type of film-sculpting polymer member.
．． It has a particle size of 01 to 10 μ, preferably 0.1 to 5 tones: It is a polymer particle with a size of Ia and O. The polymer constituting the fine particles consists of a polymer (1) and a housing diluent (2). It must be insoluble in the polymer #tK; it can be obtained by appropriately selecting the composition of the insoluble microscopic particles; that is, the polymer is originally insoluble in the polymer #tK. 〉However, this insolubility is due to the crosslinking of sufficient S* to the polymer, which is actually soluble in the solution* consisting of the polymer (4) and the diluent) if not crosslinked. When introduced, it is preferable that it be obtained by Kyoru. When the insolubility of the fine particles is achieved by crosslinking, it is preferable that the S degree of the crosslinking is not greater than the degree necessary to make the polymer insoluble. The insolubility of a microparticle polymer in a solution of microparticles (1
(parts by weight) are shaken with diluent (100 parts by weight) in KSO for minutes; the suspension is then separated at 1700 Or, p, m for 30 minutes; the supernatant liquid is removed by decantation; * W
The polymerization is dried at 150'''C for 30 minutes, and its weight is compared with the weight of the fine particles collected at the beginning of Todoroki.This test method is used to determine whether the specific gravity of the diluent is close to that of the fine particles or not. However, such diluents (e.g., chlorinated detergents) would not normally be used in the basecoat compositions of the present invention.
If KFi shows an acceptable 1!11i ILK insolubility for KFi alone, the microparticles are equally insoluble in the diluent in the presence of polymeric activity in the diluent. Possible; polymer (conversion) and diluent (2
) It is practically difficult to actually perform this test using a solution consisting of ms+.

The polymer is, for example, one of the same monomers as those mentioned in relation to the film-forming polymer component! The material can be further derived from acrylic addition polymers. −
If it is desired that the polymer is cross-linked, this can be accomplished in one of two ways: By adding a small amount of a polyfunctional monomer, such as ethylene dalicol lime I acrylate 1 or divinylbenzene, to the polymerization reaction, a large amount
In order to produce the above-mentioned nonapolymer, in the monomer of ゛,
During the polymerization reaction, such as I xy group and kdt syl group (e.g. in the case of glycidyl methacrylate and methacrylic acid), anhydride group and hydroxyl group, or incyanate group and y tetraxyl group, etc. (by adding two other monomers containing a pair of groups that can later react with each other). Alternatively, the particulate polymer may be comprised of a solid polymer, such as an ester made from a polyhydric alcohol and a polyhydric carboxylic acid. Suitable polyhydric alcohols include ethylene melipur, futavintalicol, futhylene gelicol, 1.6-1IPV lengelicol, neointylene macol, diethylene dichloromethane, triethylenediyl, tetraethylene glycol, and tetraethylene glycol. , glycerin, trimethylol fW pan, trimethyl-4-methane, interaerythritol, diintererythritol, tripentaerythritol, hexanetriol, oligomers of styrene and allylalpur (e.g. Moms
amt Ch @ mlta1, RJ 100) and the condensation product of trimethyl bread and ethyl/oxychloride (for example, ``'N1ax'' triol) [Products known as phylic acid, muconic acid, itanic acid.

Phthalic acid (or its anhydride), isophthalic acid.

Includes phthalic acid, trimellitic acid (or its anhydride) and beemeritic acid (or its anhydride).
Such polymers can be crosslinked, if desired, by adding substances of higher functionality to the raw composition, but in this case &! , by condensed heavy metal reaction) form li! Since the molecular species (sp@ci@s) distribution is specifically broad, it may be difficult to actually crosslink all of these species.

The chemical composition and degree of crosslinking of the particulate polymer can be such that the wrinkled polymer has a low Tr% glass-rubber transition temperature), in which case the particulates have rubbery properties. In addition, the above polymer may have a relatively high Tf, and the ζO particles may be hard and glassy.

As previously mentioned, the polymeric particulates must be stably dispersed in a solution consisting of the film-forming polymer of the basecoat composition and the housing diluent. The expression 'stably dispersed' means that the microparticles can be solvated by the solution, thus forming a chain-ext@nded structure.
A steric sending layer (st@ric) around a particle of a polymer molecular chain having a state of configuration
barrier) K), meaning that it has been cut down to coagulate or coagulate. In this regard, 1
The term solvated 21m refers to the fact that the polymer molecular chain dissolves in the film-forming polymer solution if it is an independent molecule.

Since the molecular chain is actually in contact with the particle at one or more points over its length Kfa, this means that the steric layer is permanently in contact with the particle. The stable polymer chain used in any particular case
It will be appreciated that the zing pol)rm*r chain) is selected depending on the liquid diluent and the type of film-forming polymer - strictly speaking, this means that the stabilizing agent weight The combination of diluent and film-forming polymer is one in which the combined molecular chains have a polarity similar to that of the diluent and film-forming polymer. It means that it is a solvent for the polymer that makes up the chain. In automotive dual-coat finishes using the basecoat compositions of the present invention, the liquid diluent (e.g., containing a substantial proportion of "strong" ester and ketone solvents) typically has a relatively high degree of polarity. Therefore, the stabilizer molecular chains on the microparticles will usually need to be of such a composition that they are naturally soluble in the types of liquids mentioned above.

It is convenient to explain the method for retaining the stabilizer molecular chains in the microparticles in connection with the method for producing the particles described below.

Polymer microparticles can be produced in a variety of ways. Polymer microparticles are prepared by adding a monomer to a steric stabilizer (st@rie) for the microparticles in an organic liquid that does not dissolve the resulting polymer.
It is preferable to produce by a method of dispersion polymerization in the presence of 5tabiliz@r). Suitable dispersion polymerization methods are well known and detailed in the literature. Acrylic acid is limited to dispersion polymerization of ethylenically unsaturated monomers such as methacrylic esters, vinyl esters, and styrene or its derivatives. The above amphipathic compound is dissolved in an inert liquid and subjected to raft polymerization in the presence of an amphiphilic dispersant dissolved in the liquid or copolymerized with a certain proportion of monomers. It consists of polymerizing the monomers in the presence of a polymeric precursor of the dispersant which is capable of forming the dispersant in situ. A general overview of the principles of this method is available in British patent no. No. 41,505, fjlkan 1,052.241
No. 1,222.597 and No. 1.231,
No. 614 specification and K, E J, Barre
Arrival at tt-Dlsperslon Polym*rlza
tionin Organic &dia' (Jo
hn Wil @ y and 8ons + 1975)
Ethyl methacrylate, butyl methacrylate, ethyl acrylate, butyl acrylate, acrylic acid 2- and Yw include vinyl propionate, vinyl propionate, styrene and vinyl toluene. %, the production of crosslinked addition polymer particles involves the addition of mutually reactive groups (in addition to polymerizable unsaturated groups) in the selected monomers, such as epoxides contained in glycidyl methacrylate and methacrylic acid. This can be achieved by incorporating a pair of monomers containing a group and a carboxyl group. For example, 4IK British Patent No. 1.0?
5.288 and 1.15, 6.012), the polymerization process does not react with each other, but later the dispersion is heated at a high temperature to raise the K. Fine particles having the above-described auxiliary reactive groups which react in a similar manner to cause crosslinking are obtained. The crosslinked addition polymer can be produced by adding a small amount of a monomer having double-blind functionality in the polymerization reaction KII, such as ethylene glycol remethacrylate or divy-winged rubenzene, to the monomers to be dispersed and polymerized. It can be manufactured by

Among the unsaturated monomers mentioned above, methyl methacrylate is a suitable monomer when it is desired that the polymer fine particles have a high Tf. If it is necessary that the microparticles have a low Tf, ethyl acrylate or vinyl acetate may be used, but methyl methacrylate and a small proportion of
When using butyl acrylate or butyl methacrylate 1
It is more convenient to copolymerize with softening monomers (ms+oftenlng'); however, it is preferred that the softening monomers do not exceed 15 parts by weight of the total monomer composition; otherwise However, the resulting polymer has a disadvantage in that it is impossible to obtain a stable dispersion of mold particles due to its excessive solubility even in low polar hydrocarbons for dispersion polymerization.Acrylic acid 2 Certain other softening monomers, such as ethoxyethyl or 2-ethoxyethyl metatallylate, may be used in proportions of 15% or more, if desired, relative to the corresponding lower alkyl ester. If it is not immediately applicable, a small amount of a comonomer containing a carboxyl group, such as acrylic acid or methacrylic acid, may be included (if it is necessary to crosslink the polymer particles, the above monomers may be added). (the proportion would be greater than that used to effect the crosslinking by co-reaction with a co-reactive monomer such as glycidyl methacrylate), whereas a small amount (additional) of engineered methoxide Monomers such as glycidyl methacrylate may also be included.

Other functional monomers such as human tetraxyethyl acrylate or acrylamide may be included in small amounts in the monomers for preparing the present particulate polymers.

For example, the method for producing a dispersion of a condensation polymer is described in English 54! Hu IK
No. 1,573.531, No. 1.403,794 and No. 1,419.199,
Methods for obtaining crosslinked polymer particles are also described in the above specification. The general principles of this process are the same as those described in relation to addition polymers, except that the monomers or starting materials used to make the condensation polymers are generally more polar). Based on this, there are differences in details. The difference is that the monomers used are generally insoluble in the liquid used to carry out the polymerization reaction. The first step in carrying out the dispersion polymerization of monomers is therefore to bring the monomers into a colloidal dispersion in an inert liquid, initially in the form of solid particles. In the second step, polymerization of monomers is carried out inside the particles. The present amphiphilic dispersant is required in each of the above steps, firstly to stabilize the monomer particles, and secondly to stabilize the produced polymer particles, but it is necessary to In such cases, a single 0 dispersant that performs the above two functions may also be used. In this method, a preformed amphiphilic dispersant is used, but the dispersant can be copolymerized or grafted with a certain proportion of the monomers to be polymerized to form the dispersant in situ. Polymeric precursors may also be used.These methods have been published in the UK. The monomeric starting materials suitable for producing the condensation polymer microparticles described in No. 487,776 may be used to produce such polymers by molten or solution polymerization methods. For example, in the case of polyester fine particles, suitable raw materials are the above-mentioned polyhydric alcohols and polyhydric carboxylic acids. In the case of polyamide microparticles, suitable raw materials include amino acids such as 6-aminocarboxylic acid and 11-aminoundecanoic acid or the corresponding latatums and (or) ethylene chloride, propylene chloride, hemochloride, etc. In front of the namesakene, diethylenetriane, and triethylenetetraenane, there are trianes such as tris(2-ethyl)methane, and polyhydric carboxylic acids such as the above-mentioned nine.

In both the case of polyester and polyamide microparticles, if it is desired to crosslink the microparticles, a proportion of starting materials with a functionality greater than 2 must be included in the mixture to be polymerized. ,
It will, of course, be understood that in any of the dispersion polymerization methods described above, the amphiphilic dispersant is a polymeric component that is solvated by the liquid used to make the dispersion, as compared to the polymer component that is solvated by the liquid used to make the dispersion. is not solvated and is anchored to the polymer fine particles.
) is a substance that has in its molecules other polymeric components such as L.Although such dispersants are soluble in the dispersion liquid as a whole, the resulting solution usually contains individual molecules and micellar aggregates. They will probably be contained in equilibrium with each other. Preferred dispersants for use in the present invention are block or graft copolymers containing two polymeric components: one of the components is a polymeric molecule that can be solvated by the dispersion liquid as described above. In addition to the chains, the other component consists of polymer molecular chains that are different from the first component and therefore are not solvated by the liquid and can be tethered to the polymer microparticles.

A particularly preferred form of such a dispersant comprises a polymeric backbone that is nonsolvating or one "anahor" component and a number of solvating polymeric molecular chains suspended from the backbone. A particular example of such a graft copolymer is a graft copolymer in which the main chain is primarily an acrylic polymer chain derived from methyl methacrylate, and the pendant chain is an aliphatic hydrocarbon chain. Poly(12-distearic acid) that can be easily solvated by the medium
are graft copolymers, which are the residues of , converting the terminal -〇〇OH in the polymeric acid into an ester derivative containing a polymerizable unsaturated group; can be produced by copolymerizing with When acrylic acid or methacrylic acid is used as the above-mentioned small proportion of the comonomer, a carboxyl group can be introduced into the main chain of the graft copolymer. If it consists only of methyl methacrylate units, it may be possible to increase the polarity.Increasing the polarity means that the main chain can be solvated by a non-polar diluent such as an aliphatic hydrocarbon. As a result, the force that anchors the main chain to the fine polymer particles increases. The fine polymer particles are preferably produced by the dispersion polymerization method as described above, but the fine particles thus obtained may be further processed. This need arises in the following cases. The most convenient inert liquids for carrying out dispersion polymerizations are low polar liquids, for example aliphatic or aromatic hydrocarbons, and mixtures thereof; this is because such liquids are addition-type and condensation-type polymers. Depending on the properties that the microparticles are desired to possess, the polymer or copolymer composition can be selected within the widest range.

However, from the above, an appropriate steric stabilizer for stabilizing the fine particle polymer in a simple low polar liquid is a It can be understood that if the mixture is transferred to the interior of the vehicle, it may not be possible to effectively stabilize the particles or particles. Another, perhaps more important reason is that the polymer molecule (4) is a relatively polar liquid (4), and the stabilizer molecules (4) react against the solvating action of the diluent. Therefore, by transferring the fine particles to the polymer 111EK, the particles become unstable) and aggregate. Therefore, in a preferred embodiment of the present invention, the dispersion polymerization method is used. The polymer fine particles produced in (2) are further soluble and combined with the volatile organic liquid component of the undercoat composition. This additional polymer (hereinafter referred to as the auxiliary polymer) is essentially non-crosslinked; the polymer particles to be engaged with the auxiliary polymer are made of a highly polar, film-forming polymer carrier and an organic diluent. When IIc is introduced into a solution consisting of Immediately after carrying out the dispersion polymerization, the monomers to produce the auxiliary polymer are polymerized in the initial inert liquid medium and in the presence of the initial dispersant. An auxiliary polymer can be conveniently tethered to the polymeric microparticles @1 The auxiliary polymer usually needs to have a composition that is compatible with the film-forming polymer and the crosslinking agent for the cough polymer. Indeed, the auxiliary polymer can be the same as the film-forming polymer, and in some cases can even replace the entire film-forming polymer, as discussed below. The monomers from which the auxiliary polymer is made will be selected with the above considerations in mind, as will be apparent to those skilled in the art.

In step 9, when the polymer fine particles treated as described above are introduced into a solution of polymer () and diluent (), a part of the auxiliary polymer may be extracted into the above-mentioned more polar medium. l
! A qualitative proportion of the auxiliary polymer may, for example, be entangled with the molecular chains of the polymer fine particles during its formation, resulting in $PJ
), or Kl! on the above molecular chain! Due to the grafting, polymer particles (solvated by the medium)
The stability of JILII polymeric microparticles in a highly polar medium (if desired) in contact with
It can be increased by forming covalent bonds between the molecular chains of the auxiliary polymer and the molecular chains of the polymer microparticles. This can be done by including an unsaturated carboxylic acid in the monomer for producing the auxiliary polymer, or the introduced carboxyl groups react with the engineered mexide groups present in the particulate polymer. In this case, the latter group is used with a slight excess of WaK to crosslink the mold particle polymer by reaction with carboxyl groups. The formulation can be done in various ways. When the particulate polymer is treated with an auxiliary polymer, a sufficient amount of the auxiliary polymer is eluted from the treated particulates so that the polymer constitutes the entire film-forming polymer component;
Alternatively, depending on whether sufficient auxiliary polymer is attached to the particulate polymer to effect stabilization of the latter, simply adding a strong solvent to the dispersion of the particulate polymer treated with Alternatively, it is sufficient to add a dispersion of particulate polymer (with or without copolymer treatment), a suitable diluent (B) and a preformed film. A further method is to prepare the particulate polymer, for example by centrifugation, filtration or spray drying, and to separate it from the larger dispersion and then to mix it with a solution consisting of the forming polymer Q. Polymer fine particles are polymerized (4
) and a diluent.

From the above explanation, the present invention Ks? It is believed that the film-forming polymer (I), if used, is composed of an auxiliary polymer that is eluted from the particulate polymer when incorporated into the basecoat composition. It will be appreciated that instead of carrying out dispersion polymerization techniques, polymer microparticles may be prepared, for example, by aqueous emulsion polymerization of suitable unsaturated monomers according to known methods. In this case, the microparticles are a charge-stabilized dispersion (
charge -5 tabllis@ddisp@rs
lon), and the microparticles themselves can be separated from the dispersion, for example by spray drying.

The ninth step to be added to the undercoat composition is to add fine particles in one powder, preferably in one powder as in the case of pigment dispersion.
(pug m1111mg) or by a method that applies high shear force to the mixture when using a three-roll electric melter),
A bath consisting of a film-forming polymer and a diluent is redispersed. Similar to pigment dispersion, one mold particle Kl! The steric stability to be determined is, for example, due to the polar groups present in the film-forming polymer, the polar groups present in the fine particle polymer, and the O
A volume of 1 Wc is obtained due to the inherent tendency of the polymer (solvated by the 11 lubricant) to be anchored to the particulate polymer (by MO interaction). Producing fine particle polymers (by aqueous emulsion polymerization) II! In addition, a certain type of difunctional unsaturated compound is contained in the polymerizable monomer to make it insoluble in the solution consisting of the film-forming polymer (1) and the diluent, regardless of the type of diluent. crosslinked polymers can be formed. In addition, as in the fine particle polymer produced by dispersion polymerization, a polymer that does not contain a difunctional substance and is compatible with a solution consisting of a polymer (conversion) and a diluent (in other words, a fine particle polymer) It is preferred to continue the emulsion polymerization using a second feedstock monomer which provides a larger polymer which will coalesce and anchor the one auxiliary polymer having the functions described above and the other.

The polymer fine particles used in the method of the present invention are as described above, and are used in an amount of 15 to S5, based on the weight of the film-forming polymer and the above-mentioned fine particles. 0 quantity KII In conjunction with 1 polymer image particle 1, when an auxiliary polymer is used, it is attached to the true polymeric microparticles, and the lower disassembly test This is also to be understood as meaning the portion of the %/% auxiliary polymer which is not dissolved by the diluent CB)K under the conditions.
It can be of a particle size of 50μ and can be any of the pigments commonly used in surface coating compositions KsP, such as titanium dioxide, iron oxide, chromium oxide, lead tetramate or carbon black. Inorganic pigments such as cyano blue and cyanine green, carpasol bioleft, anthrabilin yellow, flavanthrone yellow, isoindoline yellow, indans blue, quinacridone violet and irilene red. get).

As used herein, the term "material" also includes conventional fillers and spreading agents such as talc or kaolin.

However, the basecoat composition of the present invention, as described above, is of particular value as a basecoat composition containing round, metal flake pigments for providing a 1-glamour metallic" finish primarily on automobile bodies. Metals Presence of polymer fine particles in a pigment-containing primer composition
Therefore, the li& of metal adjustment (m@tal@ontr@l) is significantly improved when applying a base coat and then performing a transparent finish. Suitable metallic pigments include special alumite flakes and copper bronze flakes; typically any s
Pigments of the following types can be incorporated into the primer composition in an amount of 2 to 100 - based on the total weight of the film-forming polymer (1) and the particulate polymer. Preferably, the amount of pigment is between 5 and 20% by weight based on the total weight.

Such metal pigments or other pigments may be incorporated into the basecoat composition (using known dispersants). For example, if the film-forming polymer is primarily acrylic IIO,
Acrylic polymers of similar O composition can be used as pigment dispersants. Any such polymeric dispersant is considered part of the film-forming polymer. If desired, the basecoat composition may also contain other suspected additives, such as tonite or cellulose acetate butyrate. Modifiers may also be present. There are no restrictions on the type of film-forming polymer component(s) of the finisher composition used in Painter 11(c) above.
Any suitable film-forming polymer, including those commonly used in primer compositions, may be used. As with the lower Ik build-up, the polymer may be heat cured prior to heat curing.
The thermoplastic lid 04 can be removed.

However, the acrylic polymer 1IaK thermoset lid 40 is particularly suitable.
It does not have to be the same as 4). Polymer (6) clearly differs from basecoat polymers in one important respect: basecoat polymers are necessarily used in solution in the organic liquid component of the basecoat composition; , finishing machine polymer is
The finisher composition may be used in the form of a solution in a volatile vehicle liquid (7) or in the form of a stable dispersion. The vehicle liquid (7) may therefore be a bath agent for the finisher polymer or a non-solvent. Get more. When the vehicle liquid is a solvent, it may be any of the volatile organic liquids described above or mixtures thereof as suitable for use in the basecoat composition. If the vehicle liquid is a non-solvent, the scissors liquid is less polar than the solvent.
optionally one or more aliphatic hydrocarbons such as hexane, heptane or petroleum fractions with low aromatic content, provided that the entire mixture is a non-solvent for the finisher polymer; It can be a mixture of the above-mentioned hydrocarbon and a highly polar liquid as described above.

When the finisher composition is a dispersion of a polymer, the composition is usually a sterically stabilized dispersion in which the polymer particles are present as one polymer mass. stabilized (by boot stock or graft copolymers) with components that are not solvated by the carrier liquid and are tethered to the dispersed polymer.

The well-known principles for making such dispersions are described in Processes for Preparing Particulate Polymers of Primer Compositions.

If the finisher polymer is of the thermoset, ie, crosslinked type, any of the crosslinkers described in connection with the primer composition 1 may be included in the topcoat composition. If the topcoat combination is of the acrylic type, the proportions of crosslinker and polymer in the composition can vary within a very wide range;
Usually, the weight ratio of polymer and crosslinking agent is 50:50 to 90:1
The exact ratio to be used will depend on the properties desired in the final coating, but a preferred range that gives a good balance of film properties is:
The weight ratio of polymer to crosslinking agent is 60:40 to 85:15. A particularly preferred weight ratio of acrylic polymer to crosslinking agent is 70:30 when it is important that the top coat exhibits good resistance to corrosion by acids caused by significant atmospheric pollution. ~85:15.

As detailed in connection with the basecoat composition, a suitable catalyst for the crosslinking reaction may be added to the topcoat composition or the finish coat polymer may contain free acid groups.

Finisher compositions may contain both polymer solutions and polymer dispersions in some cases. Soluble polymers are preformed polymers that have a different monomer composition than the dispersion polymer, and the polymers are soluble in a liquid unlike the dispersion polymer and can be added to the dispersion as a liquid. added. In addition, soluble polymers can be produced by preferentially polymerizing certain monomers present during the production of dispersion polymers. Additionally, soluble polymers are polymers that were initially produced as dispersions, but are different from the primary film-forming agent and are added to the continuous phase liquid of the dispersion when preparing coatings with desired application properties. It may be added to the bath liquid when adding another liquid with a higher dissolving power than the liquid.

Although finisher compositions are usually substantially colorless and therefore do not significantly alter the coloring effect of the basecoat, it may be desirable in some cases to provide a clear coloration to the topcoat composition. .

In the first step of a coating method using the coating composition of the present invention, an undercoat composition is applied to the surface of a substrate that has been previously prime-coated or otherwise treated in a conventional manner. Substrates of particular interest in the context of the present invention are metals such as steel or aluminum commonly used in the manufacture of automobile bodies, but also other materials such as glass, ceramics, water exchangers and, in some cases, plastics. Materials may also be used as long as they can withstand the temperatures that will effect the final curing of the multilayer coating. After application of the basecoat composition, a polymeric film from the composition is formed on the surface of the substrate. If desired, film formation is achieved by heating the substrate and the coating applied thereto, and then applying an organic liquid diluent. This can be done by volatilizing the KFi basecoat, or, if the polymer is of a thermosetting type, by heating at a temperature sufficient to crosslink the KFi basecoat. A particular advantage of using the composition is that the finisher composition can be applied to the basecoat by simply drying for a very long time at or near room temperature, and the finisher composition and basecoat are not intermixed during this process. Alternatively, the former may dissolve the latter without interfering with the correct orientation of the multimetallic colorant, and thus an optimal 17" effect can be obtained. For example, at temperatures of 15~!lo"c. Drying for 1 to 5 minutes may prevent mixing of the two coatings. At the same time, the base coat is moderately wetted by the finisher composition, so that
Good adhesion between the coatings - After applying the finisher composition to the basecoat, the coated substrate is cured, during which time the topcoat and optionally the basecoat are cured by the crosslinking agent present. crosslinking). This curing operation is carried out at elevated temperatures normally used in curing thermosetting coating compositions.
It is usually carried out at a temperature of 100 to 400 C, but if desired, it can be carried out at a lower temperature as long as the crosslinking reaction is sufficiently carried out.

When coating using the coating composition of the present invention, the basecoat composition and finisher composition can be applied to the substrate by any conventional method such as brush coating, spray coating, dipping, flow coating, etc.
flowlng) K, but coloring adjustment (p
Spray coating is most preferred because it gives the best results in terms of pigment control), especially color control of metal pigments, and gloss. Any of the known methods of spray coating can be used, such as compressed air atomization, electrostatic atomization, thermal atomization and airless atomization, and both manual and automatic methods are suitable.

The thickness of the applied basecoat film is between 0.5 and 1.5 mils;
The thickness of the top coat film is preferably 1 to 5 mils (all thicknesses of the dry film).

Examples in which coating was performed using the undercoat composition of the present invention are shown below, and parts and weights in the examples are based on weight unless otherwise specified.

Example 1 (a) Production of fine polymer particles A reaction vessel equipped with a stirrer, a temperature needle, and a reflux condenser was charged with the following raw materials: aliphatic carbonized carbon (boiling point range 11140-156'''C1 aromatic component) Content 0)
20.01611 Methyl methacrylate
1.77<5 M methacrylic acid
0.056-azodiipteroethryl
0.140# graft copolymer stabilizer (53-solution) (see below) 0.
After purging the reaction vessel and its contents with an inert gas, the temperature was increased by 100 CK and held at this temperature for 1 hour to produce a dispersed polymer.

After premixing the following components, they were added to the reaction vessel at a constant rate for 6 hours while heating and stirring at 100@C: Methyl methacrylate 52.459 parts Glycidyl methacrylate 0.551 #Methacrylic acid 0 .551#Azo-diisobutyronitrile 0.203
part dimethylaminoethanol 0.070
# Daraft copolymer stabilizer solution (see below) 6.810
-・'Aliphatic hydrocarbon (boiling point range 140-1566C) 33.1
66 #10 (LOOO# Hold the contents of the reaction vessel at 100@CK for an additional 3 hours,
The monomer was added to the insoluble polymer gel-like fine particles (21% of the total dispersion).
~22) and uncrosslinked polymer particles (2316 of the total dispersion)
was completely converted into a dispersion containing

The nine-graft copolymer stabilizer used in the above method was prepared in the following manner: 12-hydroxystearic acid was mixed with 12-hydroxystearic acid having an acid value of approximately 31 to 44 KOH/f (molecular weight 1650 to 1
It was self-condensed to 800 K and then reacted with an equivalent amount of darisilyl methacrylate. The obtained unsaturated ester was converted into methacrylate.

Copolymerize with a methyl phosphate:acrylic acid (95:5) mixture in a 2:1 ratio (weight ratio).

(b) Modification technology of fine particle polymer with auxiliary polymer (1)
In the same reaction vessel as Step 1! (Dispersion 63 produced in -
．． 853 parts were charged. Heat the dispersion to 115°C and purge the reaction vessel with inert gas; premix the following ingredients and stir the contents of the reaction vessel at a constant temperature of 1156°C for 3 hours. Can be added in the proportion of: Methyl methacrylate
3.342W hydrodiethyl acrylate
1.906 #methacrylic acid
0.496 #Butyl acrylate
3.6.91 #2-ethyl acrylate medium 3.812 #styrene
5.7121 Azo-diisobutyronitrile 0.906-Primary-octyl mercaptan 0.847# Graft copolymer stabilizer solution (see step (&)) 1.4
95 # After the addition is complete, the contents of the reaction vessel are stirred for an additional 2 hours.
156 CK was maintained to ensure sufficient monomer conversion, and finally 13.940 parts of butyl acetate was added to bring the total to 100 parts.
．． 000 copies. The total film-forming solids content of the dispersion thus obtained was 45-46 vI. The content of insoluble gel polymer fine particles was 27.0 to 27.51. (e) Production of the undercoating composition of the present invention The following components were mixed: Dispersion produced in step 0)) 56.05
Partially butylated melamine-formaldehyde resin (6 hooptanol solution) 11.
03# Rubazole Violet Dispersion (4.1% in xylene) 2.
94-phthalocyanine blue dispersion (in xylene, 9.7') 5.8
8# force - bomb black dispersion (in xylene, 14.2 hours) 0.74
w Arun two flakes dispersion (*in the cylinder (DS 5%-4-
23. ss #butyl acetate 5
．． 14#joo, 00# The analytical values of the resulting composition are as follows: All acrylic film-forming polymer 75.0 parts (non-volatile) Insoluble acrylic polymer 28.5Vi6
(Non-volatile) Butylated M/F resin 25.0 parts (Non-volatile) @) Coating process 100 parts of the primer composition prepared in step (e) was diluted by adding 100 parts of butyl acetate to B. 8.
B,! The viscosity was determined to be 22 centimeters per cup with a solids content of 1811 g. This diluted paint was applied (by spray) to a primed metal panel to form a film having a thickness of 0,000 inches after removal of the solvent. After evaporating the solvent for 2 minutes at room temperature, 2WiA of thermosetting lid acrylic resin transparent composition was applied, during which time
Allow the solvent to evaporate for a minute.

The dry film thickness of the transparent layer was 0.0025 inch. After drying for 10 minutes at room temperature, the panel and coating were
The resulting coating, which was baked for 30 minutes at C, had an excellent appearance, exhibited a uniform aluminium metal effect, and had no metal flake migration [i.e. ) was not observed at all.6 There was no shrinkage of the transparent finish film to the undercoat film.Therefore, the high gloss of the transparent film was not impaired at all by the undercoat film, and the internal adhesion of the baked panel was good. Met. The film also had good flexibility and moisture resistance.

The top coating used above was made from the following raw materials: Nibutylated meladen-formaldehyde resin (60-butanol solution) 22.0 parts:) Bontane 9.5m Butyl glycolate 4.5 #Butanol
2.5# silicone oil 2 chronic solution
0.4u (solid content 42q&)
50 #ko0 composition mo viscosity u, B, 8.
1755: 1955 K Therefore, 25 in B3 cup
It was 60 seconds when measured at @C.

The procedure was carried out except that 36.03 parts of the dispersion produced in step 5) of Example 1 was used instead of IK, and 16.52 parts of a 45-butyl acetate solution of a thermosetting acrylic resin containing no polymer particles was used. The same ingredients as in Example 1(c) were mixed.

The analytical values of the resulting composition are as follows: All-acrylic film-forming polymer 75 parts (non-volatile) Butylated M/F resin 25 parts (non-volatile) 100 parts of the prepared primer composition was diluted with 140 parts of butyl acetate to obtain the same diluted composition as in Example 1(c) with a solids content of 18-. This composition was applied as an undercoat to a metal panel that had been undercoated in the same manner as in Example 1(d), and then the same transparent thermosetting acrylic resin composition as in Example 1(d) was applied as an overcoat and dried. After that, it was finally baked.

The resulting finished coating had a poor, uneven appearance, with areas where alumnium flakes had migrated during solvent evaporation.

Example 2 The following ingredients were mixed: 9 Nibutylated melamine-formaldehyde resin (67% dissolved in butanol*) 28.5 parts Cellulose acetate butyrate [Viscosity, 1-2 seconds, Contains 5 acetyl groups, 50 butyryl groups, ( Eastm
an-Kodak mn 531-1) 2-ethoxyethyl acetate 20-solution) 42.15 parts Modified polymer fine particle dispersion (produced in Example 1, Step-) and (b))
69. a4# Carbazole violet dispersion (in xylene, 4.1-) 7.5
9 #Phthalocyanine Blue Dispersion (9.7 bags” in xylene) 15.
21# Carbon black dispersion (%14.2 in xylene) 1.8
9 parts aluminum flake dispersion (35911 in xylene) 60.
78m 2-ethoxyethyl acetate 57.9
81 Xylene 75.00# The above composition was used in the same painting process as described in Example 1, Step-)K, and the same acrylic clear finish composition as in Example 1 was used as the finish composition. did. Results similar to those in Example 1 were obtained.

Example 3 Nibutylated meladen-formaldehyde resin mixed with the following ingredients (butanol solution in 6711) 28.
50 parts Hinyl chloride/Hinyl alcohol/Rice-vinyl acetate copolymer (91:6:3) Divinylite”■MuG
H, 20% 2-ethoxyethyl acetate solution
9!1.2Q #Modified polymer fine particle dispersion (produced in Example 1, steps (a) and (b)')
85.56-Carbazole violet dispersion (%6.1- in xylene) 10.1
Two-part phthalocyanine blue dispersion (9.7% in xylene) 20.1
8-Carbon black dispersion (14.2 hissin in xylene) 2.
52# aluminum flake dispersion (35% yeast in xylene) 81.04
-Butyl acetate 150. OO#×”
“Vinilight” is a registered trademark.

Example 1: 100 parts of the composition thus obtained was diluted by adding 33 parts of butyl acetate, and this diluted composition was used as an undercoat paint. Engineering 1! The same results as in Example 1 were obtained by spray coating in the same manner as Gi) and then applying the same acrylic clear finish composition as in Example 1.

Example 4 (a) Wetted with 6.4 parts of Improper Tool 915
．． 0 parts of nitrocellulose was dissolved in a mixture of 53.6 parts of 2-ethoxyethyl acetate and 25.0 parts of n-butanol.

28.5 parts of Nibutylated meladen-formaldehy resin C67% butanol solution mixed with ingredients of 2) 0*JL/a-sil [(above step (a))
(prepared with) 69.9
# Honey-like polymer fine particle dispersion (manufactured in actual weaving example 1, steps (a) and (b))
62.6-carbazole violet dispersion (6.1% in xylene) 7.59
m-phtatecyanine blue dispersion (in xylene, 9.7-) 15.2
11 Force - Bomb Black Dispersion (in xylene, 14.2 hours) 1.8
9 # Aluminum flake dispersion (% 35 in xylene) 60.
78 #Butyl acetate 180.0
0-(c) Coating process 100 parts of the undercoat composition prepared in step S) were diluted with 26 parts of 2-ethoxyethyl acetate to form B.8. B,
The diluted paint, which had a viscosity of 26 seconds when measured in 3 cups, was applied by spraying to the base coated metal panel, allowing all the solvent to evaporate and leaving a coating with a thickness of 0,000 inches. formed. After evaporation separation for 2 minutes at room temperature, the same thermosetting lid acrylic resin transparent composition as in Example 1 was applied to the panel twice, during which time the solvent was allowed to evaporate for 2 minutes.
The dry film thickness was 0.0025 inches. After a final solvent evaporation for 10 minutes at room temperature, the panel and coating were baked at 127° C. for 30 minutes.

The finished coating thus obtained had a sticky appearance and similar properties to the coating obtained in Example 1.

Claims (1)

[Scope of Claims] (t) The following components, namely: (a) a film-forming polymer other than a γ-lukyd resin; (B) a volatile organic liquid diluent that dissolves the above polymer; In an amount of 15 to SSS based on the total weight of the film-forming polymer and the following polymeric particles, the film-forming polymer and the diluent do not dissolve in the solution and are stable in the cough solution. Dispersed polymer fine particles; and (b) 2 to 100 based on the total weight IIK dispersed in a solution consisting of the above film-forming polymer and a diluent.
a protective and (
t) A basecoat composition suitable for use in forming decorative multilayer coatings, wherein component e) consists of metal pigment particles in an amount of 5 to 20, based on said total weight. A composition according to claim 1. The composition according to claim 2, wherein the metal pigment is aluminum flakes. 2. The composition according to claim 1, wherein the film-forming polymer) is a polymer or copolymer of 01 or more alkyl esters of acrylic acid or methacrylic acid. 5. The composition according to any one of claims 181 to 4, wherein the polymer fine particles have a particle diameter of 0.1 to 5 tones. 6. The composition according to any one of claims 1 to 5, wherein the polymer fine particles consist of one or more types of alkyl esters of acrylic acid or methacrylic acid. 2. The fine polymer particles are produced by dispersing and polymerizing monomers in an organic liquid that does not dissolve the resulting polymer in the presence of a steric stabilizer for the fine polymer particles. The composition 0 & fine particle polymer according to any one of items 1 to 6 is further dissolved in the volatile organic liquid component (6) of the undercoat composition, and is further combined with the film-forming polymer component (A). 8. The composition according to claim 7, in which nine compatible polymers (hereinafter referred to as auxiliary polymers) are anchored. Immediately after the dispersion polymerization reaction for producing the particulate polymer, polymerization of other monomers for deriving the auxiliary polymer is carried out in the inert organic medium used in carrying out the above dispersion polymerization reaction and in the above dispersion. 9. The composition according to claim 8, wherein the auxiliary polymer is anchored to the particulate polymer by carrying out the polymerization reaction in the presence of a stabilizer.