JPH07501353A - Thermosetting powder coating 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] Thermosetting powder coating composition field of invention The present invention relates to certain novel thermosetting powder coating compositions. For more details, The present invention relates to aromatic polyesters and aliphatic polyesters and self-blocking polyesters. A composition comprising a blend of lysocyanate-1 is provided.

Background of the invention Thermosetting powder coating compositions are commonly used to produce durable protective coatings on the surfaces of a variety of materials. is used to. Thermoset coatings are coatings derived from thermoplastic compositions. Compared to membranes, they are generally tougher, more resistant to solvents and detergents, and coated with metal substrates. has better adhesion to and does not soften upon exposure to high temperatures. However However, in addition to the above-mentioned desirable properties, the curing of thermosetting coatings provides excellent smoothness and flexibility. Problems have arisen in obtaining coatings with properties. Manufactured from thermosetting powder coating compositions When heated, the coating hardens and becomes relatively rough and rough before forming a smooth coating. Can result in an uneven finish. Such a coated surface, that is, a finish, Lacks the gloss and gloss of coatings typically obtained from thermoplastic compositions. rough or uneven For certain surface problems, thermosetting paints are applied from organic solvent systems or organic solvents. The environmental and safety issues often caused by evaporation of the solvent system inherently undesirable because of Solution-based coating compositions also have a utilization rate of 1 The disadvantage is that it is relatively low. That is, in some application modes, Only 60% or less of the solution-based coating composition applied is applied to the product being applied. or come into contact with the substrate. Therefore, parts that do not come into contact with the product or support being applied obviously cannot be recycled, so a significant portion of solution-based paints ends up being wasted. Ru.

Powder coating compositions must be constructed to produce smooth, glossy, even coatings. The polymeric material that forms the polymeric material must undergo a significant degree of curing, i.e., a degree of crosslinking, before the polymeric material Must melt within a certain temperature range to allow timely and sufficient flow of Must be. Powder coating compositions that have the required melting point range cure the composition. Gives a smooth, glossy coating when heated. Smooth and shiny In addition, coatings derived from thermosetting coating compositions have excellent impact strength and hardness. , exhibit flexibility, solvent resistance and chemical resistance, i.e. should exist. and For example, in the manufacture of various home appliances and automobiles, where sheet metal is bent at various angles. Used for coating thin steel sheets (coils) that are to be formed or shaped into products. Excellent flexibility is essential for powder coating compositions.

For a considerable period of time after being manufactured and packaged, powder coating compositions remain a free-flowing fine powder. It is essential that the condition remains the same. Therefore, amorphous materials used in powder coating formulations The quality polyester has a glass transition temperature (T) that is higher than the storage temperature to which the formulation is exposed. g) is desirable. Semi-crystalline polyesters and their amorphous polyesters Blends with Stell can also be used in powder coating formulations. Regarding this application , semi-crystalline polyester can be used for a period of time prior to application to the substrate, sintered in powder or It is desirable to have a significant degree of crystallinity to prevent sintering. powder coating composition The semi-crystalline polyester used in have a sufficiently low melting point range to be able to formulate powder coating formulations without causing There must be.

The relatively low melting range of semi-crystalline polyesters allows for excellent flow of the coating before curing. It is important for the formation of smooth, glossy coatings.

Finally, the production of tough coatings that are solvent and chemical resistant is commonly used in industry. It is necessary to properly crosslink powder coating compositions at specific curing temperatures and times. Ru. In curing powder coating compositions, the applied product is typically cured for about 20 minutes or more. at temperatures ranging from about 325 to 400'F (163 to 204°C) Heat to melt and flow the paint particles, then crosslinker (curing agent) and polyester react with tel. The degree of hardening is determined by the methyl ethyl ketone friction test described below. Therefore, it can be measured. Normally, thermosetting paints can withstand 200 cycles of friction. are considered fully or adequately crosslinked. Produces a properly crosslinked coating The lower the temperature and/or the shorter the curing time used to cure, the faster the production rate and This is obviously very advantageous as low energy costs can be achieved. It is white.

In the paint industry, hydroxyl polyesters and caprolactam are most commonly used. Blocked polyisocyanate powder coating systems have been used. most widely used The caprolactam-blocked polyisocyanate is usually ε-caprolactam. It is called lactam-blocked isophorone diisocyanate. For example, they are disclosed in U.S. Pat. No. 3,822. No. 240, No. 4.150,211 , and the same No. 4. 212. It is described in No. 962. However, since ε− Prolactam - a product commercially available as blocked isophorone diisocyanate The product is mainly made from the blocked difunctional monomer isophorone diisocyanate, That is, 3-isocyanatomethyl-3.

Cis and trans isomers of 5,5-trinotylcyclohexyl isocyanate mixture, its blocked trifunctional trimer, its blocked trifunctional trimer or It can consist of a mixture of monomeric, dimeric and/or trimeric forms. for example , blocked polyisocyanate compounds used as crosslinking agents are mainly ε -Caprolactam-Difunctional monomer isophorone diisocyanate to block 1 and ε-caprolactam-blocked trifunctional trifunctional isophorone diisocyanate. It can be a mixture of a number of polymers. Between isocyanato group and block compound The reaction is reversible at elevated temperatures, e.g., about 150°C or higher; At a temperature of , the isocyanato groups interact with the hydroxyl groups present on the polyester. reaction to form urethane bonds, thereby crosslinking or is cured.

Curing with ε-caprolactam blocked polyisocyanate as previously described During the process, ε-caprolactam is liberated from the powder coating composition. work empty A crosslinking agent is included in the powder coating composition to eliminate the presence of ε-caprolactam from between 1,3-diazetidine-2 of isophorone diisocyanate for use as ．． Adducts of 4-dione dimers and diols have been developed. Such additions and Powder coating compositions containing adducts are described, for example, in U.S. Pat. 413, 079 No. 3, German Patent Application Publication No. 3. 328, 133 and the Jou rnal of Chromatography. 472 (1989) 175 It is described in the literature such as ~195. These oligomeric crosslinkers are ε-cap Avoid rolactam liberation, but use in combination with commercially available amorphous polyesters. If the ε-caprolactam-blocked polyisocyanate is It has the disadvantage that it is not. Therefore, the amorphous polyester commonly used in the powder coating industry 1. of esters and isophorone diisocyanate. 3-Diazetidine-2.4- Powder coatings based on dione dimer adducts yield properly cured coatings. For Kabu-lactam-blocked isophorone diisocyanate, 3 50°F (177°C), for example, 400°F (2 04°C) and/or for a relatively long period of time. but However, the use of these relatively high temperatures can result in poor properties of the cured coating. It does not produce the degree of crosslinking necessary to provide the desired combination, particularly chemical and solvent resistance.

Furthermore, the use of such self-blocked isocyanates also generally , crosslinked by caprolactam-blocked isophorone diisocyanate This results in a coating with poorer physical properties such as impact resistance than the corresponding composition.

From 1,4-cyclohexanedicarboxylic acid and 1,4-butanediol we Blending derived aliphatic polyesters with aromatic polyesters and self-containing - Can be incorporated into powder coatings together with blocked isocyanates, and Powder coatings have better curing properties and physical properties than coatings without aliphatic polyesters. found that it has the following properties.

Brief description of the drawing Figure 1 shows the powders of Comparative Example 1 and Examples 2 and 3 described in "Experiment J" below. It is a graph of QLIV weather resistance test of a coating film. rQUV J weather resistance test Presence of exposure to high-intensity ultraviolet light, either direct sunlight or facilitated by it This is done by simulating the performance of the underlying coating. with bold dots The plot shown is the coating of Comparative Example 1; the plot shown with open circles is the coating of Example 2. With film: The plot shown as a triangle is the coating of Example 3. Gloss retention at 60° Percent retention is plotted against time (hours). This plot is fat Unpredictability of the compositions of the present invention compared to compositions that do not contain the Group polyester component. The more excellent the weather resistance, the better.

Summary of the invention The present invention relates to aromatic polyesters, aliphatic polyesters, poly(tetramethylene trans-1,4-chlorohexane-dicarboxylate) and self-blocking A novel thermosetting powder coating composition comprising a blend of crosslinking agents is provided. This rack The crosslinking agent is an adduct of 1,3-diazetinine-2,4-dione and a diol. Book The powder coating compositions of the invention and coatings derived therefrom have excellent curing properties and physical properties. It has been found that the material has physical properties, especially weather resistance.

Detailed description of the invention The present invention (1) (a) Glass transition temperature (Tg) greater than about 40°C, about 20-200 an aromatic polymer having a hydroxyl number of from about 0.1 to about 0.5 and an inherent viscosity from about 0.1 to about 0.5. from about 10 to about 80% by weight of the reester: and (b) a hydroxyl number of from about 20 to 200. and poly(tetramethylenetolane) having an inherent viscosity of about 0.1 to 0.5. (1,4-cyclohexane dihydrophoxylate) from about 90 to about 20% by weight.

A novel blend of polymers containing free hydroxy groups consisting of (2) isophorone di Isocyanate 1. 3-diazetidine-2゜4-dione dimer and structure [In the formula, R1 is divalent 1-methylene-1,3,3-)umethyl-5-cyclohexy group, i.e. the structure R2 is a divalent aliphatic, cycloaliphatic, araliphatic or aromatic group of the diol. There is an aromatic residue; and X is! , 3-diazetidine-2゜4-dionediyl group, That is, the structure ] an effective amount of the adduct (NGO vs. 01 in the formation of the adduct) with a diol having The ratio of one group is about 10,5 to I:0.9, and the ratio of acetisone dione to diol is The ratio is between 2.1 and 6.5, and the content of free isocyanate groups in the adduct is 8 wt. % or less, and the adduct has a molecular weight of about 500-4000 and a molecular weight of about 70-130° having a melting point of C). provide

The powder coating of the present invention has improved impact strength, improved flexibility, and improved weather resistance. properties and a higher degree of cure at lower temperatures than systems without aliphatic polyesters. Give to the membrane.

In the composition, both the aromatic polyester and the aliphatic polyester are Can be manufactured using legal methods.

Poly(tetramethylene trans-1,4-enchlorohexane dihydrophokylate) is 1,4-butanediol and trans-1,4-cyclohexanedicarboxylic acid Can be made from acids or diesters.

If a diester is used, add a slight excess of glycol during the transesterification reaction. It is preferable to use and remove it under reduced pressure until the desired viscosity is obtained. stomach.

Preferred aliphatic poly(tetramethylene trans-1,4-chlorohexane dicar boxylate) polyester has a Tm of about 25 to 65 in the range of about 110 to 160°C. Hydroxyl numbers in the range of IO, acid numbers below IO and about 0. Inhele of lO ~ 0.40 viscosity.

The aliphatic polyester component also contains trimethyl to increase the crosslink density of the coating. Polyol branching agents such as alcohol propane may also be included. Preferred of the present invention In one embodiment, up to about 10 mole percent of 1,4-butanediol has 2 to 2 carbon atoms. Replace with glycol 12. Examples of such glycols include ethylene Glycol, propylene glycol, 1,3-propanediol, 2,4-dimethyl Tyl-2-ethylhexane-1,3-diol, 2,2-dimethyl-1,3-diol Ropanediol, 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-butyl-1,3-propanediol Tyl-2-isobutyl-1,3-propanediol, L,3-butanediol, 1.5-bentanediol, 1.6-hexanediol, thiodiethanol, l , 2-11.3- and 1. 4-Cyclohexane dimetatool, 2. 2. 4 ．． 4-tetramethyl-1,3-cyclobutanediol, 1,4-xylylene diol All of them can be mentioned. As used herein, trans-1,4-cyclohexane dicarboxylic acid When referring to rubonic acids, a mixture consisting of at least 70% trans isomers; It refers to something.

The preferred aromatic polyester component of the composition provided by the present invention is 55° Tg greater than C, hydroxyl number in the range of about 25-80, acid number less than or equal to 15, and It has an inherent viscosity of about 0.15-0.4. Aromatic polyester components are preferred. Preferably, (+) at least 50 mol% of diacid residues are terephthalic acid residues, ( 2) At least 50 moles of 96 or 2,2-methyl-1,3-propanediol 10 mol based on the total number of moles of glycol residues and (2) and (3) derived from % or less of trimethylolpropane residues. These preferred aromatic polyesters Stell is available under the trade name Rucote 107 and Cargil resin. It is commercially available as 1Resin) 3000.

More preferred aliphatic poly(tetramethylenetrans-1,4-cyclohexane) dicarboxylate) with a hydroxyl number of about 20-200 and about 0.1-0.5 has an inherent viscosity of; less than 10 mol% of the polyol residue is trimethylol. Consists of propane residues.

The relative amounts of aromatic and aliphatic polyesters depend on a number of factors, e.g. , polyester used, crosslinking agent used and its amount, amount of pigment added, cured coating film The shape can be changed depending on the desired properties. As aforementioned , the composition of the present invention contains about 10-80% by weight of aromatic polyester and aliphatic polyester. about 20 to 90% by weight. The entertainment provided by the present invention Blends of polymers containing free hydroxy groups are preferably aromatic polyesters. 20-75% by weight and 25-80% by weight of aliphatic polyester.

Therefore, the sum of components (1) (a) and (1) (b) must be 100%! :Naruko should be understood.

1,3-diazetidine-2,4-dione dimer of isophorone diisocyanate and Adducts with diols are described in U.S. Pat. No. 4.413.079 (by reference). isophorone diisocyanate according to the method described in Diacetidine dimer of isophorone diisocyanate (preferably isophorone diisocyanate) (not containing annulate trimer) with diol at about 1:0.5 to 1:0.9, Preferably a reaction giving an isocyanate:hydroxyl ratio of I:0.6 to 1.0.8. It is produced by reacting at a specific ratio. The adduct is preferably 1450-2 having a molecular weight of 800 and a melting point of about 85-120"C. Preferred diol residues (R2) is C! ~C, the residue of a diol, most preferably l,4-butanediol It is. Such additions are marketed under the name Hills BF 1540. It's on sale.

The amount of crosslinkable adduct present in the composition of the invention depends on the aromatic polyester used. and depending on several factors as mentioned above regarding the amount of aliphatic polyester. It can be changed. Typically, hydroxy-cooperative polymers are efficiently crosslinked. The amount of crosslinkable adduct that produces a coating with a superior combination of properties is About 5-3 based on the total weight of polyester, aliphatic polyester and crosslinkable compound 0% by weight, preferably in the range of 10-25% by weight.

The crosslinkable component of the composition may be present in a very small amount, e.g., about 30% based on the total weight of the crosslinkable component. Up to % by weight of another blocked polyisocyanate, for example Hüls B 15 30. ε commercially available as Ruco Ni2 and Cargil 2400 - isophorone diisocyanate blocked with caprolactam as well as It is based on nor-blocked hexamethylene diisocyanate. slight The presence of such amounts of blocked polyisocyanates may result in very small amounts of blocked polyisocyanates. The release of the king agent, e.g. It was found that a temperature of 163"C) provided excellent crosslinking.

The powder coating composition of the present invention comprises aromatic polyester, aliphatic polyester and crosslinked polyester. The additives are triblended with other additives commonly used in powder coating compositions. and then melt-blending the solidified blend into a predetermined range suitable for the production of powder coatings. particle size, e.g., an average particle size in the range of about 10 to 300 microns. Therefore, it can be manufactured from the above composition. For example, the components of powder coating compositions and then heated to 90-130'C in a ZSK twin-screw extruder. It can be melt blended, coarsely ground and finally finely ground. The melt blend is be sufficiently low to prevent conversion of the crosslinkable adduct to the reactive form and to avoid premature crosslinking. It should be carried out at a low temperature. To minimize exposure of crosslinkable adducts to high temperatures, For this purpose, amorphous and semi-crystalline polyesters can be blended before adding the crosslinker. can.

Typical additives that can be present in powder coating compositions include entrapped Benzoin to reduce air or volatile content, forming a smooth and shiny surface Flow aids or flow modifiers that promote crosslinking on polymers with isocyanate groups. Catalysts, stabilizers, pigments and dyes that promote the cross-linking reaction between the hydroxyl groups of can be lost. It is also possible to cure or crosslink the composition without the use of catalysts, or Catalysts that promote crosslinking reactions are commonly used, for example, in amorphous and semi-crystalline polyesters. and about 0.05 to 2.0 wt% crosslinking catalyst based on the total weight of crosslinking agent. It is desirable to do so. Suitable catalysts to promote crosslinking include organotin compounds, such as For example, dibutyltin dilaurate, dibutyltin dimaleate, dibutyltin oxy tin octoate, stannous octoate, and similar compounds.

Commonly used UV stabilizers, such as T [NUVIN] 234 and Hinda De-amine light stabilizers such as TINOVIN+44 can also be used. Ru.

The powder coating composition preferably contains additives to enhance the surface condition of the cured coating of the powder coating composition. For this purpose, flow aids, also called flow control agents or leveling agents, are included. This kind of flow aid The agent typically comprises an acrylic polymer and is commercially available from several suppliers. For example, Modaflow from MOnSantOCOcompanl/ MODAFLOW) and Acronal from BASF.

Other flow control agents that can be used include Magnolia, available from 5ynthron. (Modarez) MFP, EX available from Tray Chemical 486 and MYK BYK 360P available from Mallinkrodt and Perenol F-30-P available from Henke. can be mentioned. A specific flow aid is 2-ethylene, which has a molecular weight of about 17.000. 60 mol% of hexyl methacrylate residues and about 40 mol% of ethyl acrylate residues It is an acrylic polymer containing %. The amount of flow aid present can vary between amorphous and semi-crystalline in the range of about 0.5 to 4.0% by weight based on the total weight of the quality polyester and crosslinking agent. can be.

The powder coating composition can be prepared by known methods for powder coating, e.g. Can be applied to various metal and non-metallic substrates by gun, electrostatic coating or fluidized bed coating. It can be attached. In the fluidized bed sintering method, the preheated product is coated with powder coating. Immerse in air suspension. The particle size of the powder coating composition is usually between 60 and 30 It is in the range of 0 microns. The powder is passed through the porous bottom of the fluidized bed chamber. Therefore, keep it in suspension. The product to be applied is approximately 250-400'F ( 121-205°C) and then contacted with a fluidized bed of powder coating composition. Ru. The contact time depends on the thickness of the coating intended to be produced and is typically 1~! in 2 seconds be. The temperature of the substrate being applied causes the powder to flow, thereby causing it to melt together. to form a continuous coating that is smooth, even, and dent-free. preheated product The temperature also influences the crosslinking of the coating composition and has an excellent combination of properties. Forms a tough coating film. This method uses a coating film with a thickness of 200 to 500 microns. It can be manufactured by law.

The composition can also be applied using electrostatic methods, where it is less than 100 microns, preferably Alternatively, a powder coating composition having a particle size of about 15 to 50 microns is applied by means of compressed air. The powder coating composition is blown into the applicator and applied with high-pressure direct current. Charge to a voltage of kV. The charged particles are then applied onto the grounded product. The particles adhere to the product due to their electrical charge. Heating the applied product, The powder particles are melted and cured. Obtain a coating film with a thickness of 40 to 120 microns can be done.

Another method of application of powder coating compositions is electrostatic dynamic layering, which is a combination of the two methods mentioned above. It is the law. For example, on a fluidized bed to generate an electrostatic charge such as 5O-100kV. Attach an annular or partially annular electrode to the electrode. heated (for example, 250 ~400°F) or cold, easily exposes the product to be applied to a fluidized powder. expose The applied product then cures the coating upon contact between the paint particles and the product. If the temperature has not been preheated high enough to cause crosslinking, can be done.

The powder coating composition of the present invention can be applied to resistant coatings such as glass, ceramic and various metallic materials. It can be used to apply products of various shapes and sizes made of thermal materials. This composition The product is particularly useful for producing coatings on metal and alloy products, especially steel products. Ru.

The compositions and coatings of the invention are further illustrated by the following examples. Mentioned herein The inherent viscosity (+, V, ; di/g) is 60 parts by weight of phenol and 0.5 g of polymer per 100 mL of solvent consisting of 40 parts by weight of tetrachloroethane Measurements were made at 25°C. Melt viscosity (poise) is ASTM D428 7-83 [Measured using a CI melt viscometer]. Acid value and hydroxyl value was determined by titration. They are consumed for each g of polymer KO)I Report as ■. Glass transition temperature (Tg) and melting temperature (button) are determined by differential scanning. By calorimetry (DSC), the sample is heated to melt and one of the polymers After cooling to below g, the second heating cycle was measured at a scanning rate of 20 °C/min. Ta. The Tg value is reported as the midpoint of the transition and the Tm value is reported as the peak of the transition. weight Average molecular weight (Mw) and number average molecular weight (Mn) are polystyrene standard and IJV Gel permeation chromatography in tetrahydrofuran (THF) using a detector Measured by fee.

The surface of the coating film was zinc phosphated (BOND [ERITE 37. The P arker Company) 3" x 9" of 24 gauge polished cold rolled steel prepared on a panel of Impact tester (Ga The impact strength was measured using a rdner laboratory, Inc. Ta. Slide a weight with a hemispherical nose of 5/8 inch in diameter from a specified height. It was dropped into a dowel tube and driven into the front (coated side) or back of the panel.

The highest impact without cracking the paint film was recorded in inch-bond for both the front and back sides. did.

The solvent resistance and degree of curing (crosslinking) of the coating film were measured using the methyl ethyl ketone (MEK) friction method. Measured by. In this method, a piece of cheesecloth about 0.5 inch thick is used. The coated panel was rubbed with a wrapped 2-bond ball peen hammer. Cross every 5 It was moistened with MEK after every 0 strokes. Friction continues until bare metal is observed or 2 This continued until the 00 reciprocating friction was completed. Observation of the results of each MEK friction operation on bare metal Report as the number of back-and-forth frictions required for or 200 (whichever is less).

The flexibility of the coating is determined by bending at ambient temperature according to ASTM 4145-83. 20,000 bonds/in2 ( psi) using a hydraulic jack pressurized to bend the application panel onto its back. Measured by folding back. This bending is called OT, and the bent part of the panel It means that there is nothing between the minutes (zero thickness). Bending is done using an IOX magnifier. Inspect and record a pass if no breakage of the coating is observed. Broken paint film observed If applicable, perform a second (IT) bend on the panel and form. Inspect the second bend for paint breaks and repeat this operation. A sandwich of 4 layers, 5 layers, and 6 layers that no longer shows any damage to the paint film. form. The results of each bend test are the minimum thickness of the bend that will not cause paint rupture. Tm bending). The bend test used is suitable for most purposes for which coated products are used. are unduly harsh or provide a means of comparing the flexibility of different powder coating compositions. Ru.

20° and 60° gloss levels are determined by Gloss Needle (Gardn) according to ASTM D-523. erLaboratory, Inc., Model GC-9095) and measure.

Acid number and hydroxyl number are determined by titration and consumed for each g of resin KO] (Report as ■.

The pencil hardness of the paint film is according to ASTM 3363-74 (reapproved in 1980). , the hardest pencil hardness that will not dig into the paint film. Results are presented according to the following scale: Wash: (softest) 6B, 5B, 4B, 3B, 2B.

B, HB, F, H, 2H, 3H, 4H, 5H, 6H (hardest).

The conical mandrel test is a G Ardner Laboratory, Inc. using a conical mandrel This is done by bending the panel for 15 seconds. Record pass or fail do.

The artificial weather resistance of the paint film is Cyclic Ultraviolet Weather. Expose the coated panel to 313 nm fluorescent light in a Te5ter (QUV) It was measured by Test conditions were 8 hours of light at 70°C and 45°C. The temperature was 4 hours with condensation on for 4 hours.

experiment Example 1 This example illustrates a representative method for producing aliphatic polyesters of the present invention. Ru. 3000mL 3 day round bottom equipped with stirrer, short distillation column and nitrogen inlet In a flask, add dimethylcyclohexane dicarboxylate (1259.7 g, 6. 29 mol), 1,4-butanediol (997.5 g, 11.08% mol), Limethylolpropane (73.9g, 0.55mol) and titanium tetraisopropane Fill with ropoxide/2-propertool solution (100 ppm Ti). flask and the contents are heated to a temperature of 170°C under a nitrogen atmosphere, at which point the Tanol begins to rapidly distill from the flask. Stir the reaction mixture at the same temperature for about 1 hour. After heating with stirring, the temperature was increased to 200°C for 2 hours and then to 215°C for 4 hours. ℃ and then 235°C. After 3 hours at the same temperature, mercury l Apply O vacuum for 18 minutes. Approximately 3 at 235°C under 10 mercury Continue stirring for an hour to produce a colorless polymer with low melt viscosity. The polymer is in Herendt viscosity is 0.30, melting point is 130'C, and hydroxyl number is 30.

Example 2 A powder coating composition is prepared from the following materials: 141.0 g of polyester from Example 1. Lucote 107, mainly terephthalic acid and 2,2-dimethyl-1,3-propanedio Polyester based on polyester 423.0 g Self-blocked isophorone polyisocyanate) (Hlls BF 154 0) 136.0g Ti1t 280.0g Dibutyltin dilaurate 7.0g Benzoin 7.0g Modaflow 111 (flow aid Mon5anto) 10.5g Tinupin 144 7.0g Tinuvin 234 7.0 g melt blending the materials in an APV twin screw extruder at 110°C; Grind in a Pantum mill and feed the Pantum mill with a stream of liquid nitrogen. and sieved through a 170 mesh sieve on a KEK centrifugal sifter. obtained in this way The resulting fine powder coating composition had an average particle size of about 50 microns.

The powder coating composition prepared in Example 2 was applied to the 3 inch by 9 inch panel described above. Applied electrostatically to one side. Place the coated panel in an oven at 177°C. The coating was cured (ie, crosslinked) by heating for 20 minutes. hard The resulting coating is typically about 50 microns thick.

The coating on the panel has a front and back impact strength of >160 in-lbs; The 20° and 60' gloss values are 84 and 94, respectively, and the pencil hardness is F.

The coated panels passed the 0.125 inch conical mandrel test and were T-bend flexible. The degree value is 1. After 520 hours of QUV exposure, the coating had a 60° gloss value of 50%. Hold.

Example 3 A powder coating composition was prepared from the following materials using the method described in Example 2.

Polyester of Example 1 281.8g Lecote I07, polyester as described in Example 2 281.8g self-blocked Sophorone diisocyanate (Huts BF 1540) 136.4gT+0 2280. Og Dibutyltin dilaurate 7.0g Applying the powder coating composition to a panel using the method of Example 2 and curing the coating; evaluated. The coating has a front and back impact strength of >160 inch-pounds and a The 0' and 60' gloss values are 82 and 94, respectively, and the pencil hardness is F. coating Fabric panels pass 0.125 inch conical mandrel and T-bend flexibility value is 0. After 500 hours of QUV exposure, the coating retains 50% of the 60° gloss. Ru.

Example 4 This example uses 1,4-cyclohexanedicarboxylic acid to A typical method for producing stell will be explained.

3000 mL three day round bottom flask equipped with stirrer, short distillation column and nitrogen inlet. 1,4-cyclohexanedicarboxylic acid (1100.3 g) in Sco.

6.39 mol), 1,4-butanediol (629.77 g, 6.68 mol) ), 1.5 g of butanstanic acid (PASCAT 4100) catalyst was charged. Hula The Scotch and contents were heated at 200″C for 60 minutes under nitrogen atmosphere, The temperature was then increased to 215°C for 2 hours and then held at 215°C for 8 hours. The temperature was increased to 235°C to produce a colorless polymer with low melt viscosity. Poly Mer has an inherent viscosity of 0.25, a melting point of 155°C, and a hydroxyl number of 36. It is.

Example 5 A powder coating was prepared from the following materials using the method described in Example 2: Polyester of Example 4 204.2g Lecote 107, polyester as described in Example 2 612.5g self-blocked Sophorone diisocyanate (HLIIs BF 1540) 183.4g jib Chirutin dilaurate 10.0 g Tinuvin 144 10. Og Tinuvin 234 10.0g Applying the powder coating composition to a panel using the method of Example 2 and curing the coating; evaluated. The coating has an impact strength of >160 inch-pounds on both the front and back sides, and The 0° and 60° gloss values are 84 and 96, respectively, with a pencil hardness of F. coating Fabric panels pass 0.125 inch conical mandrel and T-bend flexibility value is 0. After 600 hours of QUV exposure, the coating retains 50% of the 20° gloss. Ru.

Comparative example 1 A powder coating composition was prepared from the following materials: Nilkote 107, the polyester resin described in Example 2; Ester 968.0g Self-locked isophorone polyisocyanin-1- (Huls BF 1540) 232.0g dibutyltin dilaurate 12. 0g Tinuvin 234 12.0g A panel was coated with this powder coating composition using the method of Example 2 and the coating was heated to 177°C. The samples were cured for 20 minutes and evaluated. The applied panel has a surface impact strength of 60 inches. - pounds and the back impact strength is 10 inches-pounds. 20° and 60 The gloss values were 86 and 96, respectively.

Pencil hardness is F. Application panel is 0.125 inch conical mandrel test , with a T-bending flexibility value of 6. 220 hours QUVMT weather test exposure Afterwards, the coating retains a 60° gloss of 50%.

Fig, 1 International search report PCT/IIs 92107083 Front page continuation (51) Int, C1,' Identification symbol Internal reference number C08G 18/44 I

Claims (15)

[Claims] 1. (1) (a) Glass transition temperature (Tg) greater than about 40°C, about 20-200 an aromatic polymer having a hydroxyl number of from about 0.1 to about 0.5 and an inherent viscosity from about 0.1 to about 0.5. from about 10 to about 80% by weight of the lyester; and (b) a hydroxyl number of from about 20 to 200. and poly(tetramethylenetolane) having an inherent viscosity of about 0.1 to 0.5. (1,4-cyclohexanedicarboxylate) from about 20 to about 90% by weight; A novel blend of polymers containing free hydroxy groups and (2) isophorone diiso Cyanate 1,3-diazetidine-2,4-dione dimer and structure ▲Contains mathematical formulas, chemical formulas, tables, etc.▼ [In the formula, R1 is the structure ▲Contains mathematical formulas, chemical formulas, tables, etc.▼ R2 is a divalent aliphatic, cycloaliphatic, araliphatic or aromatic group of the diol; It is an aromatic residue; and X has a structure ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ is a 1,3-diazetidine-2,4-dionediyl group] an effective amount of adduct (the ratio of NCO to OH groups in the adduct formation is approximately 1) :0.5 to 1:0.9, and the molar ratio of diazetidinedione to diol is 2:1. ~6:5, and the content of free isocyanate groups in the adduct is not more than 8% by weight. , and the adduct has a molecular weight of about 500-4000 and a melting point of about 70-130°C. A thermosetting powder coating composition comprising a homogeneous blend of 2. The aromatic polyester component has a Tg greater than 55°C, in the range of about 25 to 80. a hydroxyl number of , an acid number of 15 or less, and an inherent viscosity of about 0.15 to 0.4. The thermosetting powder coating composition according to claim 1, comprising: 3. The aromatic polyester component includes (1) at least 50 mol% of terephthalic acid; and (2) at least 50 mol% of 2,2-dimethyl-1,3- The heat according to claim 2, comprising glycol residues derived from propanediol. Curable powder coating composition. 4. The aliphatic polyester component has a Tm in the range of about 110-160°C, about 25-160°C. Hydroxyl number in the range of 65, acid number less than 10, and ionic number from about 0.10 to 0.40. The thermosetting powder coating composition according to claim 1, which has a constant viscosity. 5. In the aliphatic polyester component, about 1 of the 1,4-butanediol residues Claim No. 0 mol% or less is replaced with a glycol residue having 2 to 12 carbon atoms Thermosetting powder coating composition of item 4. 6. In component (2), R2 is a residue of a C2-C8 diol. Thermosetting powder coating composition according to item 1. 7. Claims in which in component (2) R2 is a residue of 1,4-butanediol Thermosetting powder coating composition according to item 6. 8. A shaped or molded article coated with the cured composition of claim 1. 9. (1) (a) Glass transition temperature (Tg) greater than 40 °C, about 20-200 an aromatic polyester having a hydroxyl number and an inherent viscosity of about 0.1 to about 0.5; ester (where the aromatic polyester component is (1) at least 50 mol% terephthalate) (2) at least 50 mol% of the 2,2-dimethyl-1 , glycol residues derived from 3-propanediol and (3) (2) and ( 3) consisting of not more than 10 mol% trimethylolpropane residues based on the total moles of) about 10 to about 80% by weight; and (b) a hydroxyl number of about 20 to 200 and an inherent viscosity of about 0.1 to 0.5; poly(tetramethylenetrans-1,4-cyclohexanedicarboxylic acid) sylate) (less than 10 mol% of polyol residues are trimethylolpropane residues) from about 20 to about 90% by weight; (2) 1,3-diazetidine-2 of isophorone diisocyanate, 4-dione dimer and structure ▲Contains mathematical formulas, chemical formulas, tables, etc.▼ [In the formula, R1 is the structure ▲Contains mathematical formulas, chemical formulas, tables, etc.▼ R2 is a divalent aliphatic, cycloaliphatic, araliphatic or aromatic group of the diol; It is an aromatic residue; and X has a structure ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ is a 1,3-diazetidine-2,4-dionediyl group] an effective amount of adduct (the ratio of NCO to OH groups in the adduct formation is approximately 1) :0.5 to 1:0.9, and the molar ratio of diazetidinedione to diol is 2:1. ~6:5, and the content of free isocyanate groups in the adduct is not more than 8% by weight. , and the adduct has a molecular weight of about 500-4000 and a melting point of about 70-130°C. A thermosetting powder coating composition comprising a homogeneous blend of 10. The aromatic polyester component has a Tg greater than 55°C, in the range of about 25-80. a hydroxyl number of about 9. The thermosetting powder coating composition according to claim 9, which has a 11. The aliphatic polyester component has a Tm in the range of about 110 to 160°C, about 25 Hydroxyl numbers in the range of ~65, acid numbers of 10 or less, and about 0.10 to 0.40. 10. The thermosetting powder coating composition of claim 9 having an inherent viscosity. 12. In the aliphatic polyester component, about 1,4-butanediol residues Claims in which 10 mol% or less is replaced with glycol residues having 2 to 12 carbon atoms Thermosetting powder coating composition according to clause 11. 13. Claims: In component (2), R2 is a residue of a C2-C8 diol. Thermosetting powder coating composition according to clause 9. 14. In the claim, in component (2), R2 is a residue of 1,4-butanediol. A thermosetting powder coating composition according to Range 6. 15. A shaped or molded article coated with the cured composition according to claim 9.