CA1194633A - Weatherproof coating composition - Google Patents
Weatherproof coating compositionInfo
- Publication number
- CA1194633A CA1194633A CA000408301A CA408301A CA1194633A CA 1194633 A CA1194633 A CA 1194633A CA 000408301 A CA000408301 A CA 000408301A CA 408301 A CA408301 A CA 408301A CA 1194633 A CA1194633 A CA 1194633A
- Authority
- CA
- Canada
- Prior art keywords
- weight
- pan
- parts
- coating
- absorber
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
- C09D5/32—Radiation-absorbing paints
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/16—Nitrogen-containing compounds
- C08K5/34—Heterocyclic compounds having nitrogen in the ring
- C08K5/3467—Heterocyclic compounds having nitrogen in the ring having more than two nitrogen atoms in the ring
- C08K5/3472—Five-membered rings
- C08K5/3475—Five-membered rings condensed with carbocyclic rings
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D133/00—Coating compositions based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Coating compositions based on derivatives of such polymers
- C09D133/18—Homopolymers or copolymers of nitriles
- C09D133/20—Homopolymers or copolymers of acrylonitrile
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
- C09D7/40—Additives
- C09D7/60—Additives non-macromolecular
- C09D7/63—Additives non-macromolecular organic
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Wood Science & Technology (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Paints Or Removers (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
bstract of the Disclosure A weatherproof coating composition comprised an acrylonitrile type polymer and a minor amount of a benzotriazole type ultra-violet rays absorber. The polymer has an acrylonitrile content of at least 80% by weight, and consists of solid, spherical particles having an average particle size of 2 to 200 microns.
The amounts of the polymer and the absorber are 5 to 100 parts by weight and 0.01 ? 0.05 parts by weight relative to 100 parts by weight of the non-volatile matter of the coating composition.
The amounts of the polymer and the absorber are 5 to 100 parts by weight and 0.01 ? 0.05 parts by weight relative to 100 parts by weight of the non-volatile matter of the coating composition.
Description
The present lnvention relates to a coating composi-tlon which provides a coating layer having excellent weather-proofness on a substrate such as one formed of me-tal plates, plywood, plas-tics and concrel_e.
A variety of materials including coated steel plates have been coated for exterior use, and the weather-proofness of the coating layer is of vital importance. Most of recently available coating layers comprise an organlc resin base and an inorganic or organlc pigment added there-to. The layers deteriorate under the influence of ultra-violet rays, mois-ture, heat, ions and other environmental factors, either alone or in combination. Upon deteriora-tion, the layers crack, separate off from the substra-te, or undergo chalking. Especially, colored layers undergo a discolora~ion or a serious change of appearance such as gloss due to chal]cing.
Various attempts have been made to improve the weatherproof-ness of coating layers. For example, it has been proposed to use a resin of excellent weatherproofness as the layer-forming resin component of coating. Because of good durability, use has been made of a silicone/
acrylic type coa-ting comprising a silicone/acrylic resin modified with a silicone in-termediate, a silicone/polyester coating comprising a silicone/polyester type resin, or a fluorine type coating using vinylidene fluoride as the basic resin. However, these coatings are costly. In particular, -the fluorine ~ype coatings are hightly weatherproof, but are extremely expensive, and have an economical problem. Pig-ments usually have a considerable effect of -the absorption of ultraviolet rays in coating layers. For this reason, pigment-free coatings are not used for exterior use, although there are exceptions. ~in most cases, therefore, pigment-containing coatings, preferably coatings have a high pigment con.ent, are available. ~-Iowever, the eEfect of pigments upon the absorption of ultraviolet rays is still unsatis-3 ~
f ac tory . To protec t a subs tra te f rom ul traviole t rays, e tc ., flaky :Lnorgan.ics such as mlca-l lke iron oxide have been added. However, settlement of the coa-ting provides a prob-lem ].n connection wi th coa~ing workability or sedimentation of pigments during storage.
In addition, ultraviolet ray absoxbers, oxida-tion stabilizers, etc., have been added to coatings to improve the weatherproofness of coa-ting layers. Nonetheless, it has now been found tha-t insufficient weatherproofness is ob-tained even by the use of these addi tives .
The presen-t inventors have already f iled an applica-ti.on ~Japanese Paten-t Applica-tion No. 54-12777 published as Japanese unexamined patent publication No. 55-106299) for an invention in which coatings have incorpora-ted therein a given range of a specified granular acrylonitrile polymer (hereinaf ter called PAN) -to enhance -the matt effect, weatherproofness, etc., thereof.
These coatings show improvements in weatherproofness -to some degree due to the good weatherproofness of PAN itself. How-ever, it has now been found that a greater amount of PAN
particles makes no appreciable contribution to -the enhance-ment of weatherproofness.
As a result of extensive studies made to obtain coatings which afford coa-ting layers of excellent weatherproofness based on the prior invention, it has been discovered that the weatherproofness of .PAN particle-con-taining coating layers is considerably improved in the presence of a minor amount of ultraviolet ray absorbers, and -that the :'0 effect produced by the presence of a minor amount of ul-traviolet ray absorbers becomes more marked in presence of a grea-ter amount of PAN-part l.cl.es.
The present invention -thus provides a polymeric parL.icle-containing coa-ting which can provide a coating l.ayer having excellent weatherproofness.
According -to the present invention, there is pro-vided a highly weatherproof coa'cing compositi on which compri-ses an acrylon1tri le -type polymer having an acrylonitrile content of ~0% by weight or hlgher and consisting of sub-stantially soli.d, spherical particles having an average par-ticle size of 2 to 200 microns, said polymer being present in an amoun~ of 5 -to 1.00 parts by weight relative to 100 parts by weight of the non-volatile matter of said composi-tion, and further comprises 0.01 to 0.05 par-ts by weight of a benzotriazole type ultraviolet ray absorber relative to 100 parts by weight of said non-volatile matter.
The present invention will be fur-ther illustrated by way of the accompanying drawings, in which:-Fig. 1 is an enlarged, schematic view illustrative of the section of a coating layer ob-tainable from the coat-ing composition according to the present invention; and Fig. 2 is an enlarged, perspective plan view of PAN particles.
A variety of materials including coated steel plates have been coated for exterior use, and the weather-proofness of the coating layer is of vital importance. Most of recently available coating layers comprise an organlc resin base and an inorganic or organlc pigment added there-to. The layers deteriorate under the influence of ultra-violet rays, mois-ture, heat, ions and other environmental factors, either alone or in combination. Upon deteriora-tion, the layers crack, separate off from the substra-te, or undergo chalking. Especially, colored layers undergo a discolora~ion or a serious change of appearance such as gloss due to chal]cing.
Various attempts have been made to improve the weatherproof-ness of coating layers. For example, it has been proposed to use a resin of excellent weatherproofness as the layer-forming resin component of coating. Because of good durability, use has been made of a silicone/
acrylic type coa-ting comprising a silicone/acrylic resin modified with a silicone in-termediate, a silicone/polyester coating comprising a silicone/polyester type resin, or a fluorine type coating using vinylidene fluoride as the basic resin. However, these coatings are costly. In particular, -the fluorine ~ype coatings are hightly weatherproof, but are extremely expensive, and have an economical problem. Pig-ments usually have a considerable effect of -the absorption of ultraviolet rays in coating layers. For this reason, pigment-free coatings are not used for exterior use, although there are exceptions. ~in most cases, therefore, pigment-containing coatings, preferably coatings have a high pigment con.ent, are available. ~-Iowever, the eEfect of pigments upon the absorption of ultraviolet rays is still unsatis-3 ~
f ac tory . To protec t a subs tra te f rom ul traviole t rays, e tc ., flaky :Lnorgan.ics such as mlca-l lke iron oxide have been added. However, settlement of the coa-ting provides a prob-lem ].n connection wi th coa~ing workability or sedimentation of pigments during storage.
In addition, ultraviolet ray absoxbers, oxida-tion stabilizers, etc., have been added to coatings to improve the weatherproofness of coa-ting layers. Nonetheless, it has now been found tha-t insufficient weatherproofness is ob-tained even by the use of these addi tives .
The presen-t inventors have already f iled an applica-ti.on ~Japanese Paten-t Applica-tion No. 54-12777 published as Japanese unexamined patent publication No. 55-106299) for an invention in which coatings have incorpora-ted therein a given range of a specified granular acrylonitrile polymer (hereinaf ter called PAN) -to enhance -the matt effect, weatherproofness, etc., thereof.
These coatings show improvements in weatherproofness -to some degree due to the good weatherproofness of PAN itself. How-ever, it has now been found that a greater amount of PAN
particles makes no appreciable contribution to -the enhance-ment of weatherproofness.
As a result of extensive studies made to obtain coatings which afford coa-ting layers of excellent weatherproofness based on the prior invention, it has been discovered that the weatherproofness of .PAN particle-con-taining coating layers is considerably improved in the presence of a minor amount of ultraviolet ray absorbers, and -that the :'0 effect produced by the presence of a minor amount of ul-traviolet ray absorbers becomes more marked in presence of a grea-ter amount of PAN-part l.cl.es.
The present invention -thus provides a polymeric parL.icle-containing coa-ting which can provide a coating l.ayer having excellent weatherproofness.
According -to the present invention, there is pro-vided a highly weatherproof coa'cing compositi on which compri-ses an acrylon1tri le -type polymer having an acrylonitrile content of ~0% by weight or hlgher and consisting of sub-stantially soli.d, spherical particles having an average par-ticle size of 2 to 200 microns, said polymer being present in an amoun~ of 5 -to 1.00 parts by weight relative to 100 parts by weight of the non-volatile matter of said composi-tion, and further comprises 0.01 to 0.05 par-ts by weight of a benzotriazole type ultraviolet ray absorber relative to 100 parts by weight of said non-volatile matter.
The present invention will be fur-ther illustrated by way of the accompanying drawings, in which:-Fig. 1 is an enlarged, schematic view illustrative of the section of a coating layer ob-tainable from the coat-ing composition according to the present invention; and Fig. 2 is an enlarged, perspective plan view of PAN particles.
2 o In the drawings, reference numeral 1 stands for PAN particles .
The acrylonitrile -type polymer particle used in the present i.nvention has an acryloni-trile content of 8û% by weight or higher, and consists of an average particle size ranging from 2 -to 200 microns.
2 5 The polymer per se has excellen-t weatherproofness, and shows good ad-hesion to the matrix of -the coa-ting layer. In addition, -these polymer particles can be used in a larger amount, and be uniformly dispersed t.hroughout the coa-ting composition.
As the polymer consisting of PAN particles pre-ferably has -the highest possible acrylonitrile content for weatherproofness, it should have an acrylonitrile conten-t of at least 30% by weight. This acrylonitrile pol.ymer has extremely good weatherproofness as such for the following postula-ted reasons:-;~ - 3 -Since -the nitrile group (-C-N) of acrylonitrile st:rongly attracts an e]ectron, the -CH adjacent thereto is so strongly acldic that the alpha-position hydrogen is sus-ceptible to autoxldation, as will be appreciated from the followi.ng e~uation (I):
(I) Formation Reaction of l~ydroperoxide H El H
-CH C - CH - C - ~ - CH - C - CH - C -C--N C-N C-N C-N
(first stage formation of radical) - CH - C - CH - C
C-N C-N
(formation of hydroperoxide) However, the radical formed is then coverted to a hydroper-oxide which is brought i.n close proximity of the nitrile group, since the polyacrylonitrile is of a syndiotactic structure. The interaction of these groups produces the following stabilized s-tructure (II):
'OOH N=C~ H
1\CH2 1~CH2 ~ I \ C--N
H H H
This cuts off the autoxidation chain and s-tops the subse-quent progress of deterioration of the coating layer, -thus malcing a con-tribution to the improvement in weatherproofness.
When the acrylonitrile type polymer has an acrylonitrile content below about 30% by weight, however, the nitrile groups are so spaced àway from each o-ther in the above-mentioned formula that the radicals formed are not appreciably trapped. This is ascribable to a lowering of weatherproof-ness.
_ ~ _ i ~, The acrylonitrile type polymer as mentioned above may be prepared in the manner as described in ~apanese patent speciflcation laid open for public inspection under Nos.
52-8090, 52-40569, 52-~07045, 54-18858, 54-30281, e~c. As d~sclosed in specification No. 52-8090, for instance, a monomer comprising an ethylenic unsaturated compound con-taining acrylonitrile as main component and a sulfonic acid or its salt combined -therewith as -the remainder is poly-merized in water, and a sulfonic acid group or its salt is introduced in thus formed polymer, thereby forming an aqueous dispersion of polymer droplets in which polymer particles are present in a molten state. The aqueous dis-persion is then cooled under agi-tation while preventing coagulation of the polymer droplets, so that an aqueous dis~
persion is obtained containing substantially spherical PAN
particles formed by caking -the polymer droplets. The thus obtained aqueous dispersion is dried by spray drying, and granulated directly into PAN particles having a desired particle size distribu-t:ion.
It is noted that all the PAN polymers disclosed in the foregoing specifications may not be used as the PAN
polymers for the present invention. Accordingly, use may selectively be made of PAN polymers except for those compris-ing such a monomer as vinyl or vinylidene chloride which is basically considered to have poor weatherproofness.
The -thus obtained PAN particles are of a solid, transparent and uniform structure and are spherical. These particles have sufficient negative charges thereon, and thus are very s-tably dispersed in a coating composition. This -~5 ,, !~
allows the PAN particles to be present in a larger amount in the coating composition.
Furthermore, the PAN particles have a small speci-flc gravity as compared with usual inorganic fillers, and with difflculty settle in the coating composition, thus assuring good storage properties and coating workability.
A suitable par~icle size of the PAN particles is closely corre:lated to the thickness of a coating layer. As will be seen from Fig. 1, the greater the amoun-t of PAN
particles present on the surface of the coating layer, the better the protec-ting effect of PAN particles upon 'che coa-t-ing layer matrix. However, when the particle size of PAN
particles exceeds twice the -thickness of the coating layer, they have poor adhesion to the coating layer ma-trix, so that the separation of -the layer frorn the substrate may easily take place due to various stresses and friction during pro-cessing. When the PAN particles have a mean particle size of 2 rnicrons or less, all of the particles are virtually embedded in the coating layer, since i-t usually has a -thick-ness of 5 microns or higher. Accordingly, no pro-tecting effect is obtained. Since, in most cases, the coating layers have a -thickness of 2-300 microns, -the average par-ticle size of PAN ar-ticles preferably ranges 2 to 200 microns because a usual size distribution is close -to the logarithmic normal distribution.
Fig. 2 illustrates PAN particles having such a grain size, which are present in the coating layer.
~s~ s~
The amount of PAN par-ticles 1n the coating composi-tion ranges 5 to 100 parts by weight rel.ative -to 100 parts by weight of -the non-volat1le matter of the coating composi-ti.on to wh1ch no ultravlolet ray absorber has been addedd S (herei.nafter also called the ultraviolet ray absorber-free composlt:Lon). when the content of PAN particles is below 5 parts by weight, they produce no appreciable effect on irnproving the weatherproofness since they are spaced away from each other at too great a distance. However, the pre-sence of PAN par-ticles in a grea~er amount hardly makes contribution -to improving weatherproofness, if a minor arnount of the ultraviolet ray absorber is not present.
To this end, a minor amount of the ultraviole-t ray absorber is added l~o the coa-ting composition having a PAN particle content of at leas-t 5 parts by weight in accordance with the present invention. The effect of the absorber on weatherproofness becomes marked as the amount of PAN particles increases.
However,-the incorporation of PAN particles in too great an amount results in a lowering of-the processability of the substrate coated due to -thelr hardness. Accordingly, the content of PAN particles is preferably at most 100 par-ts by weight, and ranges 10 -to 60 par-ts by weight for usual applications for the proper-ties and performance of coatings and coating layers, res-pectively.
The ultraviolet ray absorbers used may include those based on benzophenone type, benzotriazole type, and phenyl salicylate type. When -the PAN particles are used as in -the present invention, however, the benzotriazole type ultraviolet ray absorber is most preferable.
t~,7 .,J ,~"
~l~f~
,, ~.1,~
The amount of the ultraviolet ray absorber used ranges from O.OI to 0.5parts by welgh-t relatlve -to 100 parts by we:Lght of the non-volatile matter of the ultraviolet ray absorber-free composition. In an amount of less than 0.01 part by weight, -the absorber produces no marked effec-t on improving the weatherproofness of the coating layer in cornbination with the PAN particles while, in an amount ex-ceeding 0.05 parts by welght, there is obtained no enhanced effect and the composltion becomes expensive.
in the prlor art, 0.1 to 0.5 parts by weight of the ultraviolet ray absorber has been added -to coating com-positions. In -the present invention, however, the presence of PAN particles allows the absorber to be used in a much 15 smaller amoun-t.
In accordance with the present invention, a minor amount of the ul-traviolet ray absorber contributes grea-tly to improving the weatherproofness of coating layers in 20 cooperation with -the PAN par-ticles for the following postula-ted reasons.
As illustrated in Fig.s 1 and 2, the coating layer accordirg to the present invention has its major portion 25 -ta]cen up by PAN particles. As men-tioned above, -the PAN
particles per se have good weatherproofness, and -the major portion of -the coating layer surrounded therewith have good weatherproofness as well. To add -to this, when ultraviolet rays strike upon the relatively small portion of the coat-30 ing layer which is not surrounded with PAN particles, the 'i~,;.~
basic resin and pigment of coating layer are excited under the influence of ultraviolet rays to produce radicals, which are then trapped partly by the ni-trile groups of adjacent PAN par-ticles, and stabilized according to the mecllanism as already mentioned. The ultraviolet rays are absorbed in -the absorber which are helpful for the stabiliza-tion of the coating layer.
Thus there is a considerable difference between the stabilization of the coating layer a-ttained by the pre-sen-t invention and tha-t attained by the sole use of -the benzotriazole type ultraviolet ray absorber, which may be explained in accordance wi'~h the following postulated mechanism.
The ultraviole-t ray absorber has in its chemical structure a hydroxyl group and a carbonyl group or a nitro-gen atom, which have to be combined wi-th each o-ther through a hydrogen bond. The reason why the benzotriazole -type ultraviolet ray absorber containing nitrogen shows a marked effect in the present invention is probably that hydrogen bondings are also made between the nitrile groups of PAN
particles, forming part of -the present invention, and the hydroxyl groups of the absorber with their bonding forces being similar in magnitude to those of the hydrogen bondings between the hydroxyl groups and nitrogen atoms. These hydrogen bondings are added to the hydrogen bondings present in the absorber, thereby increasing the density of hydrogen bondings, compared with -the coating layer having in its entire chemical s-tructure carbonyl groups. As a result, _ g _ . ~
ultraviolet ray energy is efflciently absorbed, and radia-ted easLIy as heat energy. A synergistic effect produced by the combinat~on of PAN particles wl-th the benzotriazole type~ u]traviolet rays absorber thus permits the amount of the absorber used to be decreased considerably.
The benzotriazole type ultraviolet ray absorber used may include 2-(2'-hydrozyl -4'-n-octoxyphenyl)benzo-triazole and 2-(2'-hydroxy-5'methyl-phenyl)benzotriazole.
From the above discussjon, it is appreciated that the grea-ter the amount of PAN particles, the better the effect of a minor amount of the ultraviolet ray absorber on improving weatherproofness. However, it should be under-stood that whether or not the above discussion is co'-rect is inde2endent of the value of the present invention.
According to the present invention, no particular limitation is placed on other cornponents and solvents re-quired for the formation of coatiny layers. The basic com-ponent formin~ coating layers may be based on polyester -type, silicone type, fluorine type or acrylic type and may be provided with various inorganic or organic pigments. As the solvent, use may be made of an organic solvent or wa-ter.
In general, any materials or solven-ts, which are now used as coating materials, and stabilize a mixture of PAN par-ticles or the ultraviolet ray absorber with other material, can be used in the present invention. The coa-ting composi-tions of the presen-t inven-tion are most easily prepared "i. ~. .
by making use of a varie~y of currently available coatings and adciing the specLfic ultraviolet ray absor~er and PAN
particles thereto in such a manner than the requirements defined in the presen-t ivnention are satisfied.
PAN particles are mixed with a vehicle or coa-ting :Ln the conventional rnanner, say, by direct mixing or knead-ing, or previously dispersing them in a coating diluent followed by sitrring.
The present invention can provide various types of coating compositions inclusive of, for instance, solvent-, nonsolvent-, aqueous-, sol-, oil-, synthetic resin-, trans-parent-, opaque-, normal temperature drying- and baking-type coa-ting compositions.
The present inven-tion will be further illus-tra-ted by way of the following Exarnples.
Examples 1-10 plus Comparative Examples 1-21 450 parts by weight of acrylonitrile, 40 parts by weight of methyl acrylate, 16 parts by weight of p-styrene sulfonic acid sodium salt and 1181 parts by weight of water were charged in a 2-liter autoclave, -to which an initiator di-tert-butyl peroxide was added in an amount of 0.5 weigh-t ~ relative to the total monomers. The autoclave was then closed to effect polymerization under agitation at 150C for 23 minu-tes. After -the completion of -eactionl the auto-clave was cooled down about 90C under con-tinued agitation, and the polymer product was discharged therefrom. The PAN
dispersion thusobtained was spray-dried into spherical PAN
particles having an average particle size of 15 microns.
So].vent type blue enamel coatings based on poly-ester were prepared, which were entirel.y free from PAN par-tlcles and ul.traviolet ray absorbers and had a non-volatile content of 50% by welght. To -these coatings were added 0, 10, 30, 50 70, 100 and 120 parts by weight of PAN par--ticles calculated relative to 100 parts by weight of -the non-volatil.e matter, and a benzotriazole ~ype ultraviolet ray absorbe:r, or another type ultraviolet ray absorber in -the amount (parts by weight) specified in Table 1 and cal-culated rela-tive to 100 parts by weight of the non-vola-tile matter. By stirring, the PAN particles and absorber were uniformly di.spersed in the coa-tings to obtain coating compositions.
lS Each of thus obtained compositions was baked onto a conventional phospha-ted zinc plate havi.ng a thickness of 0.35 mm, after epoxy type coating had been coated as a primer thereon -to a thickness of about 5 microns by ro]ling.
Thereafter, -the thus baked coating was rolled to a thick-ness of about 15 microns.
With a sunshine carbon arc type weatherometer, accelerated weathering test was carried ou-t for 2000 hours to determine the color difference of -the coated pl.ates (Color Analyzer Type 307 manufactured by Hi-tachi, L-td.) and the gloss retention thereof (expressed in -terms of the degree of reflection from a 60 mirror). The results are given in Table 1.
_,~J, l`rom Table 1, i~ is seen that -the coating composl-tions containing both PA~ particles and ultraviolet ray absorber show very exce]lent weatherproofness, while -the ultravlolet ray absorber-free compositions containing -the PAN particles show r.o apreciable improvemen-t in weatherproof-ness, compared with the PAN par-ticle-free compositions. It is also found tha'~ the application of a larger amoun-t of -the ultraviolet ray absorbers alone makes lit-tle contribu-tion to improvement in weatherproofness. The ultraviole-t ray absorbers are effective in an amount of 0.01 to 0.05 parts by weigh-t, but 0.1 part by weigh-t of the absorber does not result in an increase in weatnerproofness. Further-more, it is found that the absorber other than -the benzo--triazole type absorber does no-t bring about a significant increase in wea-therproofness, and, when the ultraviolet ray absorber is used, the greater the amount of PAN par-ticles, the better the weatherproofness. When the amount of PAN par-ticles added is 120 parts by weigh-t relative to 100 parts by weight of the 1 ,~,, ~.
-r ~ non-volatile matter, the resulting coating layer is hard an~' poor ~ processability.
TABLE
_ Ex . PAN Ultrav ioletColor Gloss Comp. Ex. (parts by ray,~ absorberdifference retention No. weight)*l (parts by (~E) (%~
_ _ weigh t ) * 1 ,_ Comp~Ex. 1 O *2 6.8 ~0~,0 Comp, Ex . 2 0 UVl 0 . 3S . 0 , 57 . 0 Comp.Ex. 3 10 0 4.8 58~5 _ _ _ Ex . 1 10 * 3 2 . 9 71 . 5 Comp . Ex . 4 10 UV2 0 . 01 4 . 5 5 9, 3 Ex. 2 10 UVl 0.05 2.5 72.5 Comp.Ex. 5 10 UV2 0.05 4~5 61.3 Comp . Ex . 6 10 UVl 0 . 1 2 . 5 7 3 . 0 Ex . 3 30 Wl 0 . 012 . 4 73 . 8 Comp.Ex. 7 30 UV2 0.01 4.5 63.8 Ex . 4 3 0 UVl 0 . 0 52 . 3 7 5 . 2 Comp.Ex. 8 30 UV2 0~05 4.4 66.0 Comp.Ex. 9 30 0 4.5 62.0 _ Ex. S 50 UVl OoOl 2~4 78.6 Comp. Ex .10 50 UV2 0 . 014 . 3 66 . 8 Ex. 6 50 UVl 0.05 4.2 80.4 Comp . Ex .11 50 UV2 0 . 0 54 . 2 60 . 9 Comp.Ex.12 50 UVl 0.1 2.2 82.0 _ ~x. 7 70 UVl 0.01 2.0 83.S
Comp.ExO13 70 UV~ 0.01 4.2 67.0 Ex. 8 70 UVl 0.05 2.0 83.7 Cc)mpOExO14 70 UV2 0.05 4.1 57.2 Comp . Ex ~ 15 7 0 4 ._0 _ 6 3 . 5 ~3L~ i ;33 _. ~
Ex. g 100 UVl 0.01 1.7 85.7 Cornp.Ex.16 100 UV2 0.01 4.1 67.1 Ex. 10 100 UVl 0.05 1.5 86.0 Comp.l,x.17 100 UV2 0.05 4.1 68.4 . _ Comp.Tx.18 100 UVl 0.1 1.4 86.5 Comp.r,x.19 100 3.8 64.4 Comp.rx.20 120 0 3.5 ~5.1 10 Comp.Fx.21 120 UVl 0.1 1.4 86.6 *1: Parts by weight are glven relative to 100 parts by weight of the non-volatile matter of PAN and ultraviolet ray absorber-free coating (this holds for the following tables)~
*2: UV 1 denotes 2-(2'-hydroxy-5'-methyl-phenyl~)benzotriazole.
*3: UV 2 deno-tes 2,2'-dihydroxy-4-methoxybenzophenone.
Examples 11-19 plus Compara-tive Examples 22-25 ln the manner as described in the previous examples, the same PAN par-ticles and a ultraviolet ray absorber, 2-(2'-hydroxy-4'-n-octoxyphenyl)benzotriazole, were uniformly dispersed in clear coatings of the solven-t type silicon ~
polyester, having a non-volatile con-tent of 50% by weight, to prepared coating compositions shown in Table 2.
Using clear coa-ting of the polyester as a primer, a 0.3 mm thic]c-stainless steel plate degreased with an alkali was roll-coa-ted and baked to form thereon a coa-ting layer having a thickness of about 5 microns (calcula-ted on dry basis). Thereafter, each of the coating composi-tions obtained as above was roll-coated and baked onto the said layer to form a layer having a thickness of 15 rnicrons cal-culated on dry basis. In this way the coated s-tainless steel plates were ob-tained.
. . .
With the thus obtained plates accelerated weather-ing test was carried out on a dew-cycle weatherometer of the sunshine carbon arc type for 1000 hours in the same manner as ln Examples 1-10. The occurrence of chalking was also determined visually.
For the purpose of comparison similar testing was carried out with the stalnless steel plates coa-ted with l:he coa.ing composit~ons which do not fall under the scope of the presen-t inventi.on. Chalking was also determined visually.
The results are shown in Table 2.
T~BLE
__ _ _ ___ _ .
Ex. PAN Ultraviolet Gloss Comp. I-x. (parts by ray absorber Chalking Reten-tion No. wei~ht) (parts by weight) __ _ _ ___ Comp. Ex.22 0 0 X 9.5 ~x. 11 10 0.01 O 70.0 Ex. . 12 10 0.05 O 72.1 Cornp. Ex . 2310 0 X 31.5 _ _. __ --- 1-Ex. 13 30 0.01 O 73.0 Ex. lfi 30 0.05 O 76.2 Comp. Ex.24 30 0 ~ 35.6 ~_ _ _ ___, Ex. 15 50 0.01 O 80.0 Ex. 16 50 0.05 O 83.1 Comp. Ex.25 50 ~ 40.3 __ ________ _ C~iALKïr,~G O not determined O sliyhtly determined ~: determined X considerabl.y determined !.``~
From Table 2, it is found that the composition, which contains the PAN particles but does not contain any ul-trav~olet ray absorber, is susceptible to chalking and shows a sign of a lowering of gloss retention, whi.le the presence of a minor amount of the ultraviolet ray absorber causes the coati.ng layer to have i.mproved wea-therproofness.
Examples 17 and 1~ plus Compara-tive Example 26 In the manner as described in Examples 1-10, PAN
particles similar to -those used in the said Examples with -the difference that their particle size is 170 microns, and an ultraviolet ray absorber 2-(2'-hydroxy-5'-methyl-phenyl) benzotriazole were uniformly dispersed in blue emulsion coatings of the solvent type acrylic system having a resi-dual con-ten-t of 50% by weight upon heating and a density of coating layer of 1.4 to obtain coating compositions as shown in Table 3.
The respective compositions were then coa-ted by brushing onto 30 x 30 cm2 concre-te plates and air dried to obta.in coating layers having a thickness of 150 microns. Out-door exposure testing was carried out for one year to de-ter-mine discoloration and cracking of these concre-te plates.
For the purpose of comparison, similar testing was also carried out with an ultraviolet ray absorber-free coating composition.
The results are shown in Table 3.
. , - 17 -, TABLE 3 _ _ _ _ .. ~.. ,~ Ex. PAN Ultraviolet ~iscoloration Cracking Comp.Ex~ (parts by ray~Absorber No. weight) (parts by weight) _ ~.
Ex. 17 30 0.05 None None Ex. 18 50 0.05 None None Comp.26 50 0 Occur Fine cracks ar~
considerably formed througholt e surface From Table 3, it is found that the PAN particles serves to .increase the weatherproofness of the layers in the presence of the ultraviolet ray~absorber, but the coating layer undergoes considerable discoloration and cracking in the absence of the l et tf~h~e~ ray~ absorber.
c~ ~
The coating compositions according to the present invention provide coating layers having highly improved weatherproofness, are inexpensive to prepare~ and are ~ industrially~ great value.
The acrylonitrile -type polymer particle used in the present i.nvention has an acryloni-trile content of 8û% by weight or higher, and consists of an average particle size ranging from 2 -to 200 microns.
2 5 The polymer per se has excellen-t weatherproofness, and shows good ad-hesion to the matrix of -the coa-ting layer. In addition, -these polymer particles can be used in a larger amount, and be uniformly dispersed t.hroughout the coa-ting composition.
As the polymer consisting of PAN particles pre-ferably has -the highest possible acrylonitrile content for weatherproofness, it should have an acrylonitrile conten-t of at least 30% by weight. This acrylonitrile pol.ymer has extremely good weatherproofness as such for the following postula-ted reasons:-;~ - 3 -Since -the nitrile group (-C-N) of acrylonitrile st:rongly attracts an e]ectron, the -CH adjacent thereto is so strongly acldic that the alpha-position hydrogen is sus-ceptible to autoxldation, as will be appreciated from the followi.ng e~uation (I):
(I) Formation Reaction of l~ydroperoxide H El H
-CH C - CH - C - ~ - CH - C - CH - C -C--N C-N C-N C-N
(first stage formation of radical) - CH - C - CH - C
C-N C-N
(formation of hydroperoxide) However, the radical formed is then coverted to a hydroper-oxide which is brought i.n close proximity of the nitrile group, since the polyacrylonitrile is of a syndiotactic structure. The interaction of these groups produces the following stabilized s-tructure (II):
'OOH N=C~ H
1\CH2 1~CH2 ~ I \ C--N
H H H
This cuts off the autoxidation chain and s-tops the subse-quent progress of deterioration of the coating layer, -thus malcing a con-tribution to the improvement in weatherproofness.
When the acrylonitrile type polymer has an acrylonitrile content below about 30% by weight, however, the nitrile groups are so spaced àway from each o-ther in the above-mentioned formula that the radicals formed are not appreciably trapped. This is ascribable to a lowering of weatherproof-ness.
_ ~ _ i ~, The acrylonitrile type polymer as mentioned above may be prepared in the manner as described in ~apanese patent speciflcation laid open for public inspection under Nos.
52-8090, 52-40569, 52-~07045, 54-18858, 54-30281, e~c. As d~sclosed in specification No. 52-8090, for instance, a monomer comprising an ethylenic unsaturated compound con-taining acrylonitrile as main component and a sulfonic acid or its salt combined -therewith as -the remainder is poly-merized in water, and a sulfonic acid group or its salt is introduced in thus formed polymer, thereby forming an aqueous dispersion of polymer droplets in which polymer particles are present in a molten state. The aqueous dis-persion is then cooled under agi-tation while preventing coagulation of the polymer droplets, so that an aqueous dis~
persion is obtained containing substantially spherical PAN
particles formed by caking -the polymer droplets. The thus obtained aqueous dispersion is dried by spray drying, and granulated directly into PAN particles having a desired particle size distribu-t:ion.
It is noted that all the PAN polymers disclosed in the foregoing specifications may not be used as the PAN
polymers for the present invention. Accordingly, use may selectively be made of PAN polymers except for those compris-ing such a monomer as vinyl or vinylidene chloride which is basically considered to have poor weatherproofness.
The -thus obtained PAN particles are of a solid, transparent and uniform structure and are spherical. These particles have sufficient negative charges thereon, and thus are very s-tably dispersed in a coating composition. This -~5 ,, !~
allows the PAN particles to be present in a larger amount in the coating composition.
Furthermore, the PAN particles have a small speci-flc gravity as compared with usual inorganic fillers, and with difflculty settle in the coating composition, thus assuring good storage properties and coating workability.
A suitable par~icle size of the PAN particles is closely corre:lated to the thickness of a coating layer. As will be seen from Fig. 1, the greater the amoun-t of PAN
particles present on the surface of the coating layer, the better the protec-ting effect of PAN particles upon 'che coa-t-ing layer matrix. However, when the particle size of PAN
particles exceeds twice the -thickness of the coating layer, they have poor adhesion to the coating layer ma-trix, so that the separation of -the layer frorn the substrate may easily take place due to various stresses and friction during pro-cessing. When the PAN particles have a mean particle size of 2 rnicrons or less, all of the particles are virtually embedded in the coating layer, since i-t usually has a -thick-ness of 5 microns or higher. Accordingly, no pro-tecting effect is obtained. Since, in most cases, the coating layers have a -thickness of 2-300 microns, -the average par-ticle size of PAN ar-ticles preferably ranges 2 to 200 microns because a usual size distribution is close -to the logarithmic normal distribution.
Fig. 2 illustrates PAN particles having such a grain size, which are present in the coating layer.
~s~ s~
The amount of PAN par-ticles 1n the coating composi-tion ranges 5 to 100 parts by weight rel.ative -to 100 parts by weight of -the non-volat1le matter of the coating composi-ti.on to wh1ch no ultravlolet ray absorber has been addedd S (herei.nafter also called the ultraviolet ray absorber-free composlt:Lon). when the content of PAN particles is below 5 parts by weight, they produce no appreciable effect on irnproving the weatherproofness since they are spaced away from each other at too great a distance. However, the pre-sence of PAN par-ticles in a grea~er amount hardly makes contribution -to improving weatherproofness, if a minor arnount of the ultraviolet ray absorber is not present.
To this end, a minor amount of the ultraviole-t ray absorber is added l~o the coa-ting composition having a PAN particle content of at leas-t 5 parts by weight in accordance with the present invention. The effect of the absorber on weatherproofness becomes marked as the amount of PAN particles increases.
However,-the incorporation of PAN particles in too great an amount results in a lowering of-the processability of the substrate coated due to -thelr hardness. Accordingly, the content of PAN particles is preferably at most 100 par-ts by weight, and ranges 10 -to 60 par-ts by weight for usual applications for the proper-ties and performance of coatings and coating layers, res-pectively.
The ultraviolet ray absorbers used may include those based on benzophenone type, benzotriazole type, and phenyl salicylate type. When -the PAN particles are used as in -the present invention, however, the benzotriazole type ultraviolet ray absorber is most preferable.
t~,7 .,J ,~"
~l~f~
,, ~.1,~
The amount of the ultraviolet ray absorber used ranges from O.OI to 0.5parts by welgh-t relatlve -to 100 parts by we:Lght of the non-volatile matter of the ultraviolet ray absorber-free composition. In an amount of less than 0.01 part by weight, -the absorber produces no marked effec-t on improving the weatherproofness of the coating layer in cornbination with the PAN particles while, in an amount ex-ceeding 0.05 parts by welght, there is obtained no enhanced effect and the composltion becomes expensive.
in the prlor art, 0.1 to 0.5 parts by weight of the ultraviolet ray absorber has been added -to coating com-positions. In -the present invention, however, the presence of PAN particles allows the absorber to be used in a much 15 smaller amoun-t.
In accordance with the present invention, a minor amount of the ul-traviolet ray absorber contributes grea-tly to improving the weatherproofness of coating layers in 20 cooperation with -the PAN par-ticles for the following postula-ted reasons.
As illustrated in Fig.s 1 and 2, the coating layer accordirg to the present invention has its major portion 25 -ta]cen up by PAN particles. As men-tioned above, -the PAN
particles per se have good weatherproofness, and -the major portion of -the coating layer surrounded therewith have good weatherproofness as well. To add -to this, when ultraviolet rays strike upon the relatively small portion of the coat-30 ing layer which is not surrounded with PAN particles, the 'i~,;.~
basic resin and pigment of coating layer are excited under the influence of ultraviolet rays to produce radicals, which are then trapped partly by the ni-trile groups of adjacent PAN par-ticles, and stabilized according to the mecllanism as already mentioned. The ultraviolet rays are absorbed in -the absorber which are helpful for the stabiliza-tion of the coating layer.
Thus there is a considerable difference between the stabilization of the coating layer a-ttained by the pre-sen-t invention and tha-t attained by the sole use of -the benzotriazole type ultraviolet ray absorber, which may be explained in accordance wi'~h the following postulated mechanism.
The ultraviole-t ray absorber has in its chemical structure a hydroxyl group and a carbonyl group or a nitro-gen atom, which have to be combined wi-th each o-ther through a hydrogen bond. The reason why the benzotriazole -type ultraviolet ray absorber containing nitrogen shows a marked effect in the present invention is probably that hydrogen bondings are also made between the nitrile groups of PAN
particles, forming part of -the present invention, and the hydroxyl groups of the absorber with their bonding forces being similar in magnitude to those of the hydrogen bondings between the hydroxyl groups and nitrogen atoms. These hydrogen bondings are added to the hydrogen bondings present in the absorber, thereby increasing the density of hydrogen bondings, compared with -the coating layer having in its entire chemical s-tructure carbonyl groups. As a result, _ g _ . ~
ultraviolet ray energy is efflciently absorbed, and radia-ted easLIy as heat energy. A synergistic effect produced by the combinat~on of PAN particles wl-th the benzotriazole type~ u]traviolet rays absorber thus permits the amount of the absorber used to be decreased considerably.
The benzotriazole type ultraviolet ray absorber used may include 2-(2'-hydrozyl -4'-n-octoxyphenyl)benzo-triazole and 2-(2'-hydroxy-5'methyl-phenyl)benzotriazole.
From the above discussjon, it is appreciated that the grea-ter the amount of PAN particles, the better the effect of a minor amount of the ultraviolet ray absorber on improving weatherproofness. However, it should be under-stood that whether or not the above discussion is co'-rect is inde2endent of the value of the present invention.
According to the present invention, no particular limitation is placed on other cornponents and solvents re-quired for the formation of coatiny layers. The basic com-ponent formin~ coating layers may be based on polyester -type, silicone type, fluorine type or acrylic type and may be provided with various inorganic or organic pigments. As the solvent, use may be made of an organic solvent or wa-ter.
In general, any materials or solven-ts, which are now used as coating materials, and stabilize a mixture of PAN par-ticles or the ultraviolet ray absorber with other material, can be used in the present invention. The coa-ting composi-tions of the presen-t inven-tion are most easily prepared "i. ~. .
by making use of a varie~y of currently available coatings and adciing the specLfic ultraviolet ray absor~er and PAN
particles thereto in such a manner than the requirements defined in the presen-t ivnention are satisfied.
PAN particles are mixed with a vehicle or coa-ting :Ln the conventional rnanner, say, by direct mixing or knead-ing, or previously dispersing them in a coating diluent followed by sitrring.
The present invention can provide various types of coating compositions inclusive of, for instance, solvent-, nonsolvent-, aqueous-, sol-, oil-, synthetic resin-, trans-parent-, opaque-, normal temperature drying- and baking-type coa-ting compositions.
The present inven-tion will be further illus-tra-ted by way of the following Exarnples.
Examples 1-10 plus Comparative Examples 1-21 450 parts by weight of acrylonitrile, 40 parts by weight of methyl acrylate, 16 parts by weight of p-styrene sulfonic acid sodium salt and 1181 parts by weight of water were charged in a 2-liter autoclave, -to which an initiator di-tert-butyl peroxide was added in an amount of 0.5 weigh-t ~ relative to the total monomers. The autoclave was then closed to effect polymerization under agitation at 150C for 23 minu-tes. After -the completion of -eactionl the auto-clave was cooled down about 90C under con-tinued agitation, and the polymer product was discharged therefrom. The PAN
dispersion thusobtained was spray-dried into spherical PAN
particles having an average particle size of 15 microns.
So].vent type blue enamel coatings based on poly-ester were prepared, which were entirel.y free from PAN par-tlcles and ul.traviolet ray absorbers and had a non-volatile content of 50% by welght. To -these coatings were added 0, 10, 30, 50 70, 100 and 120 parts by weight of PAN par--ticles calculated relative to 100 parts by weight of -the non-volatil.e matter, and a benzotriazole ~ype ultraviolet ray absorbe:r, or another type ultraviolet ray absorber in -the amount (parts by weight) specified in Table 1 and cal-culated rela-tive to 100 parts by weight of the non-vola-tile matter. By stirring, the PAN particles and absorber were uniformly di.spersed in the coa-tings to obtain coating compositions.
lS Each of thus obtained compositions was baked onto a conventional phospha-ted zinc plate havi.ng a thickness of 0.35 mm, after epoxy type coating had been coated as a primer thereon -to a thickness of about 5 microns by ro]ling.
Thereafter, -the thus baked coating was rolled to a thick-ness of about 15 microns.
With a sunshine carbon arc type weatherometer, accelerated weathering test was carried ou-t for 2000 hours to determine the color difference of -the coated pl.ates (Color Analyzer Type 307 manufactured by Hi-tachi, L-td.) and the gloss retention thereof (expressed in -terms of the degree of reflection from a 60 mirror). The results are given in Table 1.
_,~J, l`rom Table 1, i~ is seen that -the coating composl-tions containing both PA~ particles and ultraviolet ray absorber show very exce]lent weatherproofness, while -the ultravlolet ray absorber-free compositions containing -the PAN particles show r.o apreciable improvemen-t in weatherproof-ness, compared with the PAN par-ticle-free compositions. It is also found tha'~ the application of a larger amoun-t of -the ultraviolet ray absorbers alone makes lit-tle contribu-tion to improvement in weatherproofness. The ultraviole-t ray absorbers are effective in an amount of 0.01 to 0.05 parts by weigh-t, but 0.1 part by weigh-t of the absorber does not result in an increase in weatnerproofness. Further-more, it is found that the absorber other than -the benzo--triazole type absorber does no-t bring about a significant increase in wea-therproofness, and, when the ultraviolet ray absorber is used, the greater the amount of PAN par-ticles, the better the weatherproofness. When the amount of PAN par-ticles added is 120 parts by weigh-t relative to 100 parts by weight of the 1 ,~,, ~.
-r ~ non-volatile matter, the resulting coating layer is hard an~' poor ~ processability.
TABLE
_ Ex . PAN Ultrav ioletColor Gloss Comp. Ex. (parts by ray,~ absorberdifference retention No. weight)*l (parts by (~E) (%~
_ _ weigh t ) * 1 ,_ Comp~Ex. 1 O *2 6.8 ~0~,0 Comp, Ex . 2 0 UVl 0 . 3S . 0 , 57 . 0 Comp.Ex. 3 10 0 4.8 58~5 _ _ _ Ex . 1 10 * 3 2 . 9 71 . 5 Comp . Ex . 4 10 UV2 0 . 01 4 . 5 5 9, 3 Ex. 2 10 UVl 0.05 2.5 72.5 Comp.Ex. 5 10 UV2 0.05 4~5 61.3 Comp . Ex . 6 10 UVl 0 . 1 2 . 5 7 3 . 0 Ex . 3 30 Wl 0 . 012 . 4 73 . 8 Comp.Ex. 7 30 UV2 0.01 4.5 63.8 Ex . 4 3 0 UVl 0 . 0 52 . 3 7 5 . 2 Comp.Ex. 8 30 UV2 0~05 4.4 66.0 Comp.Ex. 9 30 0 4.5 62.0 _ Ex. S 50 UVl OoOl 2~4 78.6 Comp. Ex .10 50 UV2 0 . 014 . 3 66 . 8 Ex. 6 50 UVl 0.05 4.2 80.4 Comp . Ex .11 50 UV2 0 . 0 54 . 2 60 . 9 Comp.Ex.12 50 UVl 0.1 2.2 82.0 _ ~x. 7 70 UVl 0.01 2.0 83.S
Comp.ExO13 70 UV~ 0.01 4.2 67.0 Ex. 8 70 UVl 0.05 2.0 83.7 Cc)mpOExO14 70 UV2 0.05 4.1 57.2 Comp . Ex ~ 15 7 0 4 ._0 _ 6 3 . 5 ~3L~ i ;33 _. ~
Ex. g 100 UVl 0.01 1.7 85.7 Cornp.Ex.16 100 UV2 0.01 4.1 67.1 Ex. 10 100 UVl 0.05 1.5 86.0 Comp.l,x.17 100 UV2 0.05 4.1 68.4 . _ Comp.Tx.18 100 UVl 0.1 1.4 86.5 Comp.r,x.19 100 3.8 64.4 Comp.rx.20 120 0 3.5 ~5.1 10 Comp.Fx.21 120 UVl 0.1 1.4 86.6 *1: Parts by weight are glven relative to 100 parts by weight of the non-volatile matter of PAN and ultraviolet ray absorber-free coating (this holds for the following tables)~
*2: UV 1 denotes 2-(2'-hydroxy-5'-methyl-phenyl~)benzotriazole.
*3: UV 2 deno-tes 2,2'-dihydroxy-4-methoxybenzophenone.
Examples 11-19 plus Compara-tive Examples 22-25 ln the manner as described in the previous examples, the same PAN par-ticles and a ultraviolet ray absorber, 2-(2'-hydroxy-4'-n-octoxyphenyl)benzotriazole, were uniformly dispersed in clear coatings of the solven-t type silicon ~
polyester, having a non-volatile con-tent of 50% by weight, to prepared coating compositions shown in Table 2.
Using clear coa-ting of the polyester as a primer, a 0.3 mm thic]c-stainless steel plate degreased with an alkali was roll-coa-ted and baked to form thereon a coa-ting layer having a thickness of about 5 microns (calcula-ted on dry basis). Thereafter, each of the coating composi-tions obtained as above was roll-coated and baked onto the said layer to form a layer having a thickness of 15 rnicrons cal-culated on dry basis. In this way the coated s-tainless steel plates were ob-tained.
. . .
With the thus obtained plates accelerated weather-ing test was carried out on a dew-cycle weatherometer of the sunshine carbon arc type for 1000 hours in the same manner as ln Examples 1-10. The occurrence of chalking was also determined visually.
For the purpose of comparison similar testing was carried out with the stalnless steel plates coa-ted with l:he coa.ing composit~ons which do not fall under the scope of the presen-t inventi.on. Chalking was also determined visually.
The results are shown in Table 2.
T~BLE
__ _ _ ___ _ .
Ex. PAN Ultraviolet Gloss Comp. I-x. (parts by ray absorber Chalking Reten-tion No. wei~ht) (parts by weight) __ _ _ ___ Comp. Ex.22 0 0 X 9.5 ~x. 11 10 0.01 O 70.0 Ex. . 12 10 0.05 O 72.1 Cornp. Ex . 2310 0 X 31.5 _ _. __ --- 1-Ex. 13 30 0.01 O 73.0 Ex. lfi 30 0.05 O 76.2 Comp. Ex.24 30 0 ~ 35.6 ~_ _ _ ___, Ex. 15 50 0.01 O 80.0 Ex. 16 50 0.05 O 83.1 Comp. Ex.25 50 ~ 40.3 __ ________ _ C~iALKïr,~G O not determined O sliyhtly determined ~: determined X considerabl.y determined !.``~
From Table 2, it is found that the composition, which contains the PAN particles but does not contain any ul-trav~olet ray absorber, is susceptible to chalking and shows a sign of a lowering of gloss retention, whi.le the presence of a minor amount of the ultraviolet ray absorber causes the coati.ng layer to have i.mproved wea-therproofness.
Examples 17 and 1~ plus Compara-tive Example 26 In the manner as described in Examples 1-10, PAN
particles similar to -those used in the said Examples with -the difference that their particle size is 170 microns, and an ultraviolet ray absorber 2-(2'-hydroxy-5'-methyl-phenyl) benzotriazole were uniformly dispersed in blue emulsion coatings of the solvent type acrylic system having a resi-dual con-ten-t of 50% by weight upon heating and a density of coating layer of 1.4 to obtain coating compositions as shown in Table 3.
The respective compositions were then coa-ted by brushing onto 30 x 30 cm2 concre-te plates and air dried to obta.in coating layers having a thickness of 150 microns. Out-door exposure testing was carried out for one year to de-ter-mine discoloration and cracking of these concre-te plates.
For the purpose of comparison, similar testing was also carried out with an ultraviolet ray absorber-free coating composition.
The results are shown in Table 3.
. , - 17 -, TABLE 3 _ _ _ _ .. ~.. ,~ Ex. PAN Ultraviolet ~iscoloration Cracking Comp.Ex~ (parts by ray~Absorber No. weight) (parts by weight) _ ~.
Ex. 17 30 0.05 None None Ex. 18 50 0.05 None None Comp.26 50 0 Occur Fine cracks ar~
considerably formed througholt e surface From Table 3, it is found that the PAN particles serves to .increase the weatherproofness of the layers in the presence of the ultraviolet ray~absorber, but the coating layer undergoes considerable discoloration and cracking in the absence of the l et tf~h~e~ ray~ absorber.
c~ ~
The coating compositions according to the present invention provide coating layers having highly improved weatherproofness, are inexpensive to prepare~ and are ~ industrially~ great value.
Claims (3)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A coating composition comprising an acrylonitrile type polymer having an acrylonitrile content of 80% by weight or higher and consisting of substantially solid, spherical particles having an average particle size of 2 to 200 microns, said polymer being present in an amount of 5 to 100 parts by weight relative to 100 parts by weight of non-volatile matter of said composition, and comprising 0.01 to 0.05 parts by weight of a benzotriazole type ultraviolet ray absorber relative to 100 parts by weight of said non-volatile matter.
2. The coating composition as recited in claim 1, in which said benzotriazole type ultraviolet ray absorber used in 2-(2'-hydroxy-4"-n-octoxyphenyl)benzotriazole.
3. The coating composition as recited in claim 1, in which said benzotriazole type ultraviolet ray absorber used in 2-(2'-hydroxy-5'-methyl-phenyl)benzotriazole.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56117798A JPS5819368A (en) | 1981-07-29 | 1981-07-29 | Coating with excellent weathering resistance |
| JP56-117798/1981 | 1981-07-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1194633A true CA1194633A (en) | 1985-10-01 |
Family
ID=14720541
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000408301A Expired CA1194633A (en) | 1981-07-29 | 1982-07-28 | Weatherproof coating composition |
Country Status (6)
| Country | Link |
|---|---|
| JP (1) | JPS5819368A (en) |
| KR (1) | KR840000621A (en) |
| CA (1) | CA1194633A (en) |
| DE (1) | DE3228167A1 (en) |
| FR (1) | FR2510591B1 (en) |
| GB (1) | GB2106913B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0621234B2 (en) * | 1987-03-25 | 1994-03-23 | 大日精化工業株式会社 | Pigment composition and method for producing the same |
| JPH0621233B2 (en) * | 1987-03-25 | 1994-03-23 | 大日精化工業株式会社 | Pigment composition and method for producing the same |
| JP3978648B2 (en) * | 2002-02-06 | 2007-09-19 | 日本エクスラン工業株式会社 | Polyacrylonitrile polymer fine particles |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1469096A (en) * | 1965-12-24 | 1967-02-10 | Film-forming compositions and their applications | |
| JPS55106269A (en) * | 1979-02-08 | 1980-08-14 | Nisshin Steel Co Ltd | Paint and metal plate coated therewith |
| JPS55161838A (en) * | 1979-06-01 | 1980-12-16 | Japan Synthetic Rubber Co Ltd | Resin composition |
-
1981
- 1981-07-29 JP JP56117798A patent/JPS5819368A/en active Pending
-
1982
- 1982-07-28 CA CA000408301A patent/CA1194633A/en not_active Expired
- 1982-07-28 FR FR8213215A patent/FR2510591B1/en not_active Expired
- 1982-07-28 DE DE19823228167 patent/DE3228167A1/en active Granted
- 1982-07-28 KR KR1019820003380A patent/KR840000621A/en unknown
- 1982-07-29 GB GB08221942A patent/GB2106913B/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5819368A (en) | 1983-02-04 |
| DE3228167A1 (en) | 1983-02-17 |
| FR2510591A1 (en) | 1983-02-04 |
| GB2106913B (en) | 1984-10-31 |
| DE3228167C2 (en) | 1990-06-13 |
| GB2106913A (en) | 1983-04-20 |
| KR840000621A (en) | 1984-02-25 |
| FR2510591B1 (en) | 1986-03-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1286045C (en) | Microbubble-filled article such as a pressure-sensitive adhesive tape | |
| CA1336994C (en) | Coating composition | |
| CA1195035A (en) | High solids coating composition of an enamel containing a rheology control additive of silica and polyethylene glycol | |
| CA1196442A (en) | Vinylic polymer coating compositions for two coat-one bake systems | |
| KR20050007471A (en) | Non-yellowing polyester coating composition | |
| GB2458772A (en) | An Aqueou Coating | |
| CA1168787A (en) | Metallic painting | |
| US5202378A (en) | Process for producing an exterior latex paint having improved chalk adhesion | |
| JP3904095B2 (en) | Powder coating composition and coating method thereof | |
| US4795785A (en) | Coating resin composition | |
| EP0992554A1 (en) | Resin compositions for coatings | |
| CA1194633A (en) | Weatherproof coating composition | |
| KR100593472B1 (en) | Method of forming coating film on plastic substrate | |
| EP2260076B1 (en) | Resin compositions for wrinkle pattern paints | |
| JP3801347B2 (en) | Paint finishing method and painted article | |
| EP0705311B1 (en) | Isophorone-free fluorocarbon coating composition | |
| CN114525070A (en) | Deep-matting outdoor polyester resin powder coating and preparation method thereof | |
| JP4434507B2 (en) | Multi-layer coating formation method | |
| EP4365257A1 (en) | A coating composition, a method for producing a cured coating, and an article comprising a cured coating | |
| JP2583230B2 (en) | Coating composition | |
| JPH04371265A (en) | Thermosetting coating composition | |
| JP3994493B2 (en) | Coating composition, coating finishing method, and coated article | |
| JPH10292147A (en) | Coating composition | |
| JPH0598207A (en) | Water-based coating composition | |
| JP3612827B2 (en) | Resin composition for powder coating |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |