KR950006939B1 - Coating composition - Google Patents

Abstract

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Description

Coating composition with improved pore resistance

The present invention relates to coating compositions with improved void resistance, and more particularly to techniques for improving the void resistance of coating compositions which are not suitable as primers due to poor void resistance.

Recently, urethane bumpers and many other foamed plastic products have been produced by the so-called RIM method (reaction-injection molding method), and the coating composition is applied thereto. However, these products contain a lot of foam and unreacted raw materials, and thus trapped gases and unreacted materials as they rise to the surface of the coating when the conventional coating composition is applied and dried, There is a tendency to cause the same poor coating appearance (the above defective coating appearance is indicated by voids in the specification and claims). Therefore, lacquer-type primers or two-component urethane primers containing thermoplastic high molecular weight resins having relatively excellent pore resistance have generally been used for coating such products. However, since the former is a lacquer composition, the primer is susceptible to swelling or dissolution when the upper coating is made thereon, which worsens the appearance of the finish, and in the latter case, since it is a two-component composition, a short pot horizontal There is a problem of (pot-Iife), poor use characteristics.

At relatively low reaction temperatures, if a resin is developed that can be used in a one-component coating composition to resist attack of the top coating solvent and is capable of crosslinking, this would be of great use as a coating composition for plastic products.

로 표시되는 락톤에 의해 변성되며, 전체수지상 고체중에서, 상기 성분(C)의 함량이 5 내지 50중량%이고, 단, 상기 성분(C)와 락톤의 합계가 전체 수지상 고체의 60중량%의 상한선을 초과하지 않아야하고, 수지의 수지산가가 5 내지 40이고, 상기 수지산가를 높일 수 있는 카르복실그룹중 20내지 100몰%가 상기의 산(A)으로부터 유도되는, 새로운 부류의 산-조절된, 락톤-변성형 폴리에스테르 수지를 발견하였으며, 이러한 수지는 특허출원되어 일본공개특허 공보번호 332695/87로 공개되어 있다.In view of this, the present inventors have (1) a polycarboxylic acid and (B) other polycarboxylic acid that provide a proper midpoint potential of -250 mV or more by a non-aqueous potentiometer titration in the state where the resin acid value (A) can be increased. A polybasic acid component, and (2) a polyvalent alcohol component consisting of (C) a long-chain diol having a methylene linear chain of at least 7 carbons, (D) another diol, and (E) at least three hydroxyl groups, consisting of a polyhydric alcohol, General formula R represents an alkylene group having from C to C ₁₀

It is modified by lactone represented by, and the content of the component (C) is 5 to 50% by weight of the total resinous solid, provided that the sum of the component (C) and lactone is the upper limit of 60% by weight of the total dendritic solid And a new class of acid-controlled resins having a resin acid value of from 5 to 40 and from 20 to 100 mole percent of the carboxyl groups capable of raising the resin acid value are derived from the acid (A). And lactone-modified polyester resins have been found, which are disclosed in Japanese Patent Application Laid-open No. 332695/87.

Primer compositions based on the polyester resins can be easily applied onto various plastic products, and have a good finish appearance even when applied with a top coat. However, it was surprisingly found that the pore resistance was poor when the primer was applied on RIM urethane or reinforced RIM urethane (R-RIM) products. In addition, the chipping primers proposed so far have the same problem of poor porosity resistance and thus cannot be used as primers for RIM urethane products.

It is therefore an object of the present invention to provide a coating composition, preferably a one-component crosslinking primer composition, which can be applied onto a RIM urethane or R-RIM urethane product and which is excellent in pore resistance, coating properties, and finish appearance of the top coating. It is in It is an additional object of the present invention to provide an excellent means for improving the pore resistance of coating compositions which cannot be used as primers for foamed materials due to insufficient pore resistance.

According to the present invention, the above-mentioned objects are (A) a film-forming polyester resin, which is heated at a temperature of 120 ° C. in a drying furnace for 1 minute and then measured at 60 ° C. to give a coating having a film viscosity of 35000 poise or less, and Solvent-based coating composition based on melamine resin, and (B) 4 to 20% by weight of the total solid of the resin microparticles uniformly and stably dispersed in the component (A), the primer is measured at 60 ℃ It can be achieved by the primer composition of the present invention, having a film viscosity of 35000 poise or more.

When testing the pore time it is found that most of the pore-coated plates are placed in a drying furnace and occur 1 to 3 minutes thereafter. At that point, the temperature of the coated plate reaches 60 to 80 ° C. in a drying furnace (120 ° C.). In another test, the inventors tested the film viscosity of various coatings at a defined temperature after heating in a drying furnace maintained at 120 ° C., and because of their good pore resistance properties, for urethane bumpers and other foamed plastic products In the case of lacquered primers generally used, the viscosity at 60 ° C. is relatively high, i.e. 58000 poise / 60 ° C. for urethane modified polyester resin base compositions, and 39800 for polyester / melamine resin base compositions. The viscosity of other compositions with poise / 60 ° C., while low porosity resistance, for example, is the above-mentioned one-component crosslinked primer having excellent top coat appearance and coating properties developed by the inventors for plastic materials, for example. 23000 poise / 60 ° C. for the chipping primer and 2000 poise / 60 ° C. for the excellent chipping primer OP-4 Only relatively low, we have found that you can not use for the foam products because of their deficient pore resistance.

From the above, the viscosity of the lacquer-type primer having poor pore resistance and excellent porosity resistance at 60 ° C. of the coating composition which cannot be used as a primer for foamed plastic products, especially the above-mentioned one-component crosslinked primer It is anticipated that the object of the present invention can be achieved if useful devices are made for increasing to such a high level.

에 의해 변성되는 폴리스테르 수지(필름·형성수지로서)와 멜라민 수지(교차결합제로서)의 조합물을 수지 전색제로서 갖는 1성분 교차결합형 프라이머 조합물에서 특히 바람직한 피복 조성물이며, 전체 수지상 고체중에 상기 성분(C)의 함량은 5 내지 50중량%, 상기 성분(E)의 함량은 3 내지 15중량%, 그리고 상기 락톤의 함량은 5 내지 50중량%이고, 단, 상기 성분(C)와 락톤의 합계는 전체수지상 고체중의 60중량%의 상한선을 초과하지 않아야하고, 수지의 수지산가는 5 내지 4이고, 상기 수지산가를 높일 수 있는 카르복실그룹의 20 내지 100몰%는 상기 산(A)로부터 유도된다.As a result of our extensive research, it has been found that the addition of resin particles, in particular crosslinked polymer microparticles, is the most effective means for improving the pore resistance of the coating compositions mentioned above, and on the basis of this finding Was completed. That is, in the present invention, a relatively poor porosity resistance, in other words, the film viscosity of the coating heated at a temperature of 120 ° C. for 1 minute in a drying furnace, measured at 60 ° C. or less, and the chipping primer and one-part crossover as mentioned above are 35000 poise or less. Coating compositions such as binding primers are advantageously used. However, from the viewpoint of the coating appearance of the top coat subsequently applied, (1) (A) polycarboxylic acid which provides a proper midpoint potential of -250 mV or more by non-aqueous potentiometric titration in a state where the resin acid value can be increased; B) a polybasic acid component consisting of other polycarboxylic acids and (2) a long chain diol having a methylene linear chain of (C) 7 or more carbons, (D) another diol, and (E) 3 or more hydroxyl groups A general formula consisting of a polyhydric alcohol component consisting of a polyhydric alcohol, wherein R represents an alkylene group having C ₄ to C ₁₄

It is a particularly preferred coating composition in a one-component crosslinked primer combination having a combination of a polytere resin (as a film-forming resin) and a melamine resin (as a crosslinking agent) which is modified by the resin as a resin developer, The content of component (C) is 5 to 50% by weight, the content of component (E) is 3 to 15% by weight, and the content of lactone is 5 to 50% by weight, provided that the content of component (C) and lactone is The sum should not exceed the upper limit of 60% by weight of the total resinous solids, the resin acid value of the resin is 5 to 4, and 20 to 100 mol% of the carboxyl groups capable of increasing the resin acid value are the acid (A). Derived from.

The film-forming resin used is an acid-controlled Rockton-modified polyester resin as defined by a specific combination of parameters.

In the preparation of polyester resins from polybasic acid and polyhydric alcohol components, when two or more polybasic acids each having different acidity are used together as the polybasic acid component, an acid having a strong acidity is incorporated into the polyester chain more quickly than an acid having a weak acidity. Most of the carboxyl groups of the obtained resin, which can contribute to the increase of the resin acid value, are generated by the carboxyl groups of the polybasic acids having relatively weak acidity. When such polyester resin is used with melamine resin as a crosslinking agent, the crosslinking reaction cannot be sufficiently performed. Therefore, Japanese Laid-open Patent Publication No. 4054/84 discloses, in order to provide a pollingster resin having improved curability under relatively low curing temperature, the addition order and amount of polybasic acids having different acidity to the reaction system, The polybasic acid having a stronger acidity is adjusted to be added to the later stage of the esterification reaction, whereby the amount and type of carboxyl groups contributing to the increase in the resin acid value of the obtained resin are controlled.

It is an object of the present invention to provide a curable primer composition for foamed plastic products, in particular urethane bumpers, etc., according to the above-mentioned technique, 20 to 100 mol% of the carboxyl groups contributing to the increase in resin acid value are Polyester resin used by using a specific amount of polybasic acid that provides a proper midpoint potential of -250 mV moving as the acid component of the resin, with a non-aqueous potentiometric titration, in a state where the resin acid value can be increased so as to be derived from a specific acid. It is considerably preferable that the curing temperature of is lowered significantly. Examples of such polybasic acids having an appropriate midpoint potential of at least -250 mV with a non-aqueous potentiometer titration include trimellitic acid (-240 mV), pyromellitic anhydride (-240 mV), tetrachlorophthalic anhydride (-120 mV), sulfophthalic anhydride ( -40 to 50mV).

However, as a primer for plastic materials, simply low curing temperature properties are not sufficient, and should have not only sufficient strength, such as improved water resistance, but also excellent adhesion and warpage properties.

로 표시되는 고리형 에스테르의 전체 수지상 고체의 5내지 50중량%에 의해 변성되고, 이것에 의해 수지에 충분한 가요성을 제공하고 이들의 접착성 및 휨성질을 개량시킨다는 점에서 유용성이 발견된다.Therefore, in the polyester resins preferably used in the present invention, long chain diols having a methylene linear chain of at least C ₇ are used as part of the polyhydric alcohol component in an amount of 5 to 50% by weight of the total dendritic solid, and thus obtained A general formula wherein the polyester resin represents an alkylene group in which R has C ₄ to C ₁₀

It is found to be modified in that it is modified by 5 to 50% by weight of the total dendritic solid of the cyclic ester represented by, thereby providing sufficient flexibility to the resins and improving their adhesion and warpage properties.

Preferably, the total amount of the long chain diols and lactones above should be limited to 60% by weight or less of the total dendritic solid.

Examples of long chain diols having a methylene linear chain of at least C ₇ include 1, 7-pentanediol, 1, 8-heptanediol, 1, 9-nonanediol, 1, 10-decanediol, 1, 11-undecandiol, 1, 12-dodecanediol, 1, 13-tridecanediol, 2, 5-dimethyl-2, 5-hexanediol and the like.

However, the present invention cannot be limited to only the diols exemplified above, and all long chain diols having a methylene linear chain of C ₇ or more can be satisfactorily used. Among these, particularly preferred are diols having two hydroxyl groups at both ends, in particular 1, 9-nonanediol.

By the adoption of such diols, the extensibility of polyester resins, especially at low temperatures, and flexibility are greatly improved.

In view of the amount of such diols, the inventors have found that at a level of 5% by weight or less in the total dendritic solid, it is insufficient to obtain a coating having desirable elongation and flexibility at low temperatures, and at least 50% by weight. This becomes excessively soft, causing a decrease in blocking properties. In order to obtain a polyester resin capable of obtaining a coating having excellent flexibility, warpage properties and top coat adhesion, it is not sufficient to use only the above-mentioned long chain diols as part of the polyhydric alcohol component, and the aforementioned general It is essential to include in the resin molecule a specific amount of particular lactone represented by the formula.

Examples of such lactones are ε-caprolactone, ξ-enanthlactone, η-caprylolactone, and their cyclosubstituted derivatives. Particularly preferred lactones are lactones having 6 to 8 carbon atoms.

These lactones are incorporated into the polyester resin by ester bonds through reaction with the hydroxyl groups of the resin, resulting in relatively long chain flexible elements of the resin formed. However, if the amount of such lactone is too large, the obtained resin becomes excessively soft, and if the amount of lactone is too small, it becomes impossible to give the desirable effect of such modification. Therefore, preferably the amount of lactone should be determined in the range of 5 to 50% by weight of the total dendritic solid. Furthermore, in view of the object of the present invention, in order that the components of the polyester resin and the resin have the desired flexibility, the total amount of the long chain diols and lactones mentioned should not exceed the upper limit of 60% by weight of the total resinous solid. do. The polyester resin mentioned above is usually combined with a melamine resin to obtain a cured coating component.

In the present invention, in order to obtain a highly crosslinked rigid coating, it is common to include in the molecule an alcohol having three or more hydroxyl groups corresponding to 3 to 15% by weight of the total dendritic solid as part of the polyhydric alcohol component. Such polyester resins can be advantageously produced by the method described in pending Japanese Patent Application Laid-open No. 4054/84. That is, in the state where the dendritic acid value can be increased, a mole of polycarboxylic acid (A) and b mole of other polycarboxylic acid (B) which provide an appropriate intermediate potential of -250 mV or more with a non-aqueous potentiometer titration are A polyester prepolymer containing as a polybasic acid component and having a resin acid value of N is reacted with an acid mixture of (aa ₁ ) moles of acid (A) and b moles of acid (B) with a polyhydric alcohol mixture of the required composition to react with M. A prepolyester having a resin acid value was obtained, and a ₁ mole of acid (A) was added to the prepolyester thus obtained, and the mixture was subjected to the esterification reaction until the resin acid value N was reached. The polyester prepolymer thus obtained is then subjected to the required amount of lactone represented by the following general formula

In the above-mentioned description, a ₁ is less than or equal to a mole and represents the amount of acid (A) to be charged in the next step, which is determined by the following equation.

Wherein N is the resin acid value of the polyester prepolymer. (KOH mg required to neutralize 1 g of dendritic solid material) (Prepolymer represents polyester before lactone-modification), W is the weight of the prepoly, f is the number of functional groups owned by component (A), P is later % Reaction of component (A) in the charging step, X is the molar percentage of component (A) incorporated into the carboxyl group, which may indicate the resin acid value and wherein 10 ≦ X ≦ 100 is determined within the range. M is the resin acid value of the prepolymer determined by the following formula:

"Prepolymer" is a ₁ will mean the intermediate polyester prior to the addition of one mole of (A), will be limited in the range of 5 to 50% by weight of the total amount of resinous solid lactone, the sum of ethylene's seven or more carbon atoms The total amount of the long chain diols and linear lactones mentioned above should not exceed 60% by weight of the resin weight. In the present invention, as a crosslinking agent for the above-mentioned special polyester resin, melamine resin is optionally used. Examples of such melamine resins are methylated methylol melamine butylated methylol melamine and the like, with butylated methylol melamine being particularly preferred. In forming the coating composition, solvents and crosslinking agents and pigments capable of dissolving the above-mentioned film-forming polyesters can be usefully added. If desired, other conventional additives as surface control agents, other resins, and the like may be added. In the present invention, as the most characteristic feature of the present coating composition, 4 to 20% by weight of the total solids of the composition of the polymer microparticles is stable and uniformly mentioned acid-controlled-lactone-modified-polyester resin, It is dispersed in a mixed system of melamine resin and organic solvents. The microparticles of these polymers may be of the same species and provide for a stable and uniform dispersion in the coating composition. The stable dispersibility mentioned is most conveniently performed by the adoption of crosslinks and the selective use of special protective colloidal materials in the so-called emulsion polymerization and in the preparation of polymer microparticles by the NAD method.

Particularly preferred are the crosslinked polymer microparticles mentioned in Japanese Patent Laid-Open No. 129066/83 of polymer microparticles, which are effective in the presence of a resin having an amphoteric group in a molecule having the following general formula, or α-β Prepared by copolymerization of ethylenically unsaturated monomer (s).

Wherein R is a substituted or unsubstituted alkali or phenylene group having 1 to 6 carbon atoms, and Y is a -COOH or -SO ₃ H group in an aqueous solution or an organic solvent.

Alternately, these polymer microparticles first prepare polymer microparticles from α, β-ethylenically unsaturated monomers by the NAD method and then add a specially selected monomer to the system, and add the monomer on the surface of the pre-prepared microparticles. The polymerization reaction of the polymer can be carried out to modify the polymer microparticles so as to stably and uniformly disperse the coating composition (see Japanese Patent Laid-Open No. 133234/78; 133285/78; 133236/78; 150439/79). .

As already mentioned, these polymer microparticles can advantageously be composed of crosslinked polymers, but can also be non-crosslinked polymers with high glass transition points. Techniques involved in the preparation of such polymers are well known in the art, and thus detailed descriptions have been omitted.

The polymer microparticles are added in an amount of 4 to 20% by weight, preferably 5 to 10% by weight of the total solids of the coating composition. If the amount of such fine particles is 4% by weight or less of the total solid, the object of the present invention of improving the pore resistance of the coating composition can hardly be achieved, while if the amount is 20% by weight or more, the desired low temperature property is easily lowered, and thus Not desirable

The inventors have also found that the initial viscoelasticity of the resulting coating is significantly improved when the functional groups such as carboxyl, sulfone and hydroxyl groups are transported onto the polymer microparticles, resulting in a marked increase in the desired pore resistance. In this embodiment, a particularly advantageous functional group is the sulfone group.

Since the coating composition of the present invention can be provided as a one-component composition, it has excellent use characteristics and can be cured at a low temperature of 100 to 120 ° C. that can withstand urethane materials, and the coating produced has a markedly increased first. It has a viscoelasticity of, resists supernatant forces induced by contained gases and unreacted materials (means excellent pore resistance) and is very useful as a primer for RIM urethane or R-RIM urethane products. When the top coat is applied here, it is possible to obtain a coat having a good finish appearance.

The invention will be explained in more detail in the following examples. Unless otherwise specified, all parts and percentages are by weight.

[Production Example 1]

The amount of isophthalic acid, adipic acid, trimethylolpropane, nenopentyl glycol, and 1, 9-nonanediol is added to the reaction vessel equipped with a heater, agitator, reflux condenser, water separator and thermometer, and the mixture is heated. The contents reach the agitable condition, and stirring is started at a step in which the temperature is increased to 220 ° C. During the heating, the temperature is gradually increased from 160 ° C. to 220 ° C. at a constant rate within 3 hours while withdrawing the formed water from the reaction system. When the temperature reaches 220 ° C., the mixture is kept at the same temperature for 30 minutes, 3 parts of xylene is slowly added, and the condensation reaction is continued until the resin acid value reaches 2.0. The temperature is then lowered to 100 ° C. to obtain polyester prepolymer A-1. 92 parts of tetrachlorophthalic anhydride are then added and the mixture is heated to 150 ° C. and reacted at the same temperature until a stable resin acid value of 20 is obtained. In this step, the reaction mixture is cooled to obtain polyester prepolymer A-2. When 731 parts of ε-caprolactone were added, the combined mixture was heated to 150 ° C., and the reaction percentage of the cararolactone determined by tracking the amount of unreacted caprolactone by IR means reached 98% or more. Reaction at the same temperature until. In this step, the reaction is stopped, the reaction mixture is cooled and 750 parts of xylene are added to give an epsilon -caprolactone modified polyester resin having a varnish viscosity of W, a resin acid value of 10.0 and a non-volatile component of 75%. .

[Production Example 2]

To a reaction vessel equipped with a heating device, agitator, reflux condenser, water separator, fractional distillation tube and thermometer, 65.0 parts of isophthalic acid, 23.0 parts of neopentylglycol and 26.1 parts of 1,6-hexanediol are added and the mixture is heated. do. In the step of reaching the state where the contents of the reaction vessel can be stirred, 0.02 parts of dibutyl tin oxide was added and the contents were started to mix, and then the temperature of the reaction was raised to a temperature of 220 ° C. During the heating, the temperature was slowly raised from 180 ° C to 220 ° C in 3 hours at a constant rate, and the water formed in the meantime was withdrawn from the system. When the temperature reaches 220 ° C., the reaction mixture is kept at 220 ° C. for 1 hour, slowly adding 5 parts of xylene, and the condensation reaction is continued until the resin acid value reaches 1.0. Thereafter, the temperature was lowered to 100 ° C., and then 70 parts of xylene and 86 parts of cyclolexanone were added to obtain a polyester resin. Next, 7.2 parts of diisocyanate hexamethylene is added in the presence of an inert gas, and the reaction mixture is heated to a temperature of 120 ° C. and then maintained at the same temperature for 3 hours to obtain a urethane-modified polyester resin varnish A.

[Manufacture example 3]

Preparation of SO ₃ H Series Polymer Microparticles

134 parts of bishydroxyethyltaurine, 236 parts of azelaic acid, 186 parts of phthalic anhydride and 27 parts of xylene are added to a reaction vessel equipped with a stirrer, a condenser, a thermometer, a decanter, and a nitrogen gas inlet tube, and water formed from the reaction system is added to xylene and The mixture was heated while being azeotropically removed. The temperature is raised to 190 ° C. for 2 hours from the start of reflux and stirring and the dehydration reaction is continued until the acid value based on the carboxyl group reaches 145. The mixture is cooled to 140 ° C. and 314 parts of Cardula E-10 (trade name, Shell, Glycidyl Ester) are added dropwise at the same temperature for 30 minutes and then the reaction is stopped in this step. Therefore, the polyester resin thus obtained has a resin acid value of 59, a hydroxyl value of 90 and a number average molecular weight of 1054. To a reaction vessel equipped with a stirrer, a condenser, a thermometer and a nitrogen gas inlet tube, 420 parts of deionized water, 20 parts of the above polyester resin and 0.85 parts of dimethylethanol amine are added, and the mixture is melted at 80 ° C. under stirring, and then 1 A mixed solution of parts ammonium persulfate and 30 parts deionized water is added. While maintaining the same temperature, a mixture of 66 parts styrene, 2 parts 2-acrylamido-2-methylpropanesulfonic acid and 32 parts divinylbenzene was added dropwise to the reaction mixture for 150 minutes.

After the addition was completed, 0.5 parts of a mixture of ammonium persulfate and 30 parts of deionized water was added and the combined mixture was stirred for 100 minutes to obtain particles having an average diameter of 0.03 μ with a solid content of 20%. The containing emulsion was obtained. The use of azeotropic distillation means replaced the solvent with xylene to obtain a xylene dispersion of polymer microparticles having a non-volatile content of 25% by weight with an average side diameter of 0.2μ.

[Production Example 4]

Preparation of COOH-based Polymer Microparticles

To a reaction vessel equipped with a stirrer, a condenser, a thermometer, a decanter, and a nitrogen gas inlet tube, 134 parts of bisjdroxyethyltaurine, 236 parts of azelaic acid, 186 parts of phthalic anhydride and 27 parts of xylene are added, and the water formed from the reaction system is added to xylene and The mixture is heated while being azeotropically removed. The dehydration reaction is continued until the temperature of 190 ° C. is reached for 2 hours from the start of reflux and stirring until the acid value based on the carboxyl group reaches 145. The mixture is cooled to 140 ° C. and 314 parts of Cardula E-10 (trade name, shell, Versacetic Glycidyl Ester) are added dropwise at the same temperature for 30 minutes, and then the reaction is stopped at this stage. The polyester resin thus obtained has a resin acid value of 59, a hydroxyl value of 90 and a number average molecular weight of 1054. To the reaction vessel equipped with a stirrer, a condenser, a thermometer and a nitrogen gas inlet tube, 420 parts of deionized water, 20 parts of the above polyester resin and 2 parts of dimethylethanolamine are added, and the mixture is melted at a temperature of 80 ° C. under stirring. Then, a mixed solution of 1 part ammonium persulfate and 30 parts deionized water was added. While maintaining a temperature of 80 ° C., a mixture of 66 parts xylene, 2 parts methacrylic acid and 32 parts divinylbenzene was added dropwise to the reaction mixture for 150 minutes. After the reaction was completed, 0.5 parts of ammonium persulfate and 30 parts of deionized water were added and the combined mixture was stirred for 100 minutes to obtain particles having an average diameter of 0.03 μ with a solid content of 20%. The containing emulsion was obtained. The solvent was replaced by xylene by azeotropic distillation means to obtain a xylene dispersion of polymer fine particles having a non-volatile content of 25% by weight with an average side diameter of 0.2 mu.

Production Example 5

Preparation of OH-based Polymer Microparticles

134 parts of bishydroxyethyl taurine, 236 parts of azelaic acid, 186 parts of phthalic anhydride, and 27 parts of xylene are added to a reaction vessel equipped with a stirrer, a condenser, a thermometer, a decanter, and a nitrogen gas inlet pipe, and the formed water is added to xylene and While azeotropically removing together, the mixture is heated and refluxed. The dehydration reaction is continued until the temperature of 190 ° C. is reached for 2 hours from the start of reflux and stirring until the acid value based on the carboxyl group reaches 145. The mixture was then cooled to a temperature of 140 ° C. and 314 parts of Cardula E-10 (trade name, shell, Versacetic Glycidyl Ester) were added dropwise at the same temperature for 30 minutes and then the reaction was stopped at this stage. Let's do it. The polyester resin thus obtained has a resin acid value of 59, a hydroxyl value of 90 and a number average molecular weight of 1054. 420 parts of deionized water, 20 parts of the above polyester resin and 2 parts of dimethyl ethanolamine are added to a reaction vessel equipped with a stirrer, a condenser, a thermometer, and a nitrogen gas inlet tube, and the mixture is melted at a temperature of 80 ° C. under stirring. Then a mixture of 1 part ammonium persulfate and 30 parts deionized water was added. While maintaining a temperature of 80 ° C., a mixture of 66 parts of styrene, 2 parts of hydroethylethyl methacrylate and 32 parts of divinylbenzene was added dropwise to the reaction mixture for 150 minutes. After the addition was completed, 0.5 parts of a mixture of ammonium persulfate and 30 parts of deionized water was added and the combined mixture was stirred for 100 minutes to obtain particles having an average diameter of 0.03 μ with a solid content of 20%. The containing emulsion was obtained. The solvent was replaced with xylene by azeotropic distillation means to obtain a xylene dispersion of polymer microparticles having a non-volatile content of 25% by weight with an average diameter of 0.2 μ.

[Manufacture example 6]

Preparation of Highly Crosslinked Polymer Microparticles

To a reaction vessel equipped with a stirrer, a condenser, a thermometer, a decanter, and a nitrogen gas inlet tube, 134 parts of bishydroxyethyltaurine, 236 parts of azelaic acid, 186 parts of phthalic anhydride and 27 parts of xylene are added, and the formed water is combined with xylene. The mixture is heated and refluxed while removing azeotropically. The temperature is raised to 190 ° C. for 2 hours from the start of reflux and stirring, and dehydration is continued until the acid value based on the carboxyl group reaches 145. The mixture was then cooled to a temperature of 140 ° C. and 314 parts of Cardula E-10 (trade name, shell, Versacetic Glycidyl Ester) were added dropwise at 140 ° C. for 30 minutes and then the reaction was carried out. It was stopped at the stage. The polyester resin thus obtained has a resin acid value of 59, a hydroxyl value of 90 and a number average molecular weight of 1054. To a reaction vessel equipped with a stirrer, a condenser, a thermometer and a nitrogen gas inlet tube, 420 parts of deionized water, 20 parts of the polyester resin and 2 parts of dimethyl ethanolamine were added, and the mixture was stirred at a temperature of 80 ° C. After melting, a mixed solution of 1 part ammonium sulfate and 30 parts deionized water was added. 40 parts of methyl methacrylate, 20 parts of n-butylacrylate, and 40 parts of ethylene glycol dimethacrylate were added dropwise to the reaction mixture for 150 minutes while maintaining the temperature at 80 ° C. After the addition is completed, 0.5 parts of a mixture of ammonium persulfate and 30 parts of deionized water is added and the combined mixture is stirred for 100 minutes to obtain particles having a solid content of 20% and an average diameter of 0.03μ. The containing emulsion was obtained. The solvent was replaced by xylene by an azeotropic distillation means to obtain a xylene dispersion of polymer fine particles having a mean side diameter of 0.2 mu and containing a non-volatile content of 25% by weight.

Example 1

The following materials shown in Table 1 were transferred to the reaction vessel, premixed using a disper and then well dispersed in an SG mill for 1 hour. The coating composition was prepared using the dispersion paste thus obtained and the formulation shown in Table 2.

TABLE 1

Composition of dispersion paste

* One… Resin obtained in Production Example 2

TABLE 2

Composition of Coating Composition

*2… Resin obtained in Production Example 1

The primer composition A of the present invention was obtained by adding, mixing and dispersing the SO ₃ H-based polymer fine particles obtained in Preparation Example 3 in an amount corresponding to 5% by weight of all solids.

[Examples 2 to 4]

The same methods as mentioned in Example 1 were repeated, except that instead of SO ₃ H based polymer fine particles, respectively, COOH based polymer fine particles, OH based polymer fine particles or highly crosslinked polymer fine particles obtained in Preparation Examples 4 to 6, respectively. To obtain the primer compositions B, C and D of the present invention, respectively.

Example 5

The same methods mentioned in Example 1 were repeated, except that the amount of the SO ₃ H series polymer fine particles was increased by 10% by weight to obtain the primer composition E of the present invention.

Example 6

The same methods mentioned in Example 1 were repeated except that the amount of SO ₃ H series polymer microparticles was increased to 20% by weight to obtain the primer composition F of the present invention.

[Comparative Examples 1 to 3]

The same method mentioned in Example 1 was repeated three times. However, in each case, the following denaturation was adopted. That is, in Comparative Example 1, no SO ₃ H series polymer fine particles were used; In Comparative Example 2, the amount of SO ₃ H series polymer fines was reduced to 2% by weight; And in Comparative Example 3 the amount of SO ₃ H based polymer fine particles was increased to 30% by weight of the total solids.

RIM urethane test pieces were washed with trichloroethane vapor and within 20 minutes after the above washing, each primer composition obtained in Examples 1-6 and Comparative Examples 1-3 was used for different test pieces. After standing for 10 minutes, these test pieces were dried in a drying furnace maintained at a temperature of 120 ° C. for 30 minutes, and then each coated test pieces were prepared having a coating having a dry film thickness of 30 to 35 mu. The visual appearance and ultimate resistance were visually observed and evaluated in each case using the following criteria, and the test results are shown in Tables 3 and 4.

Ultimate resistance

Evaluated by water size shown in ASTM number 714-56

1: no

2: 9F

3: 9MD to D

4: 8F to D

5: 8F to less than D

The void resistance of 3 to 5 is not beneficial.

Outer appearance:

◎: excellent

○: superior

△: not superior, slightly rough

X: poor and very rough

Viscosity:

Measured using an E-type bismeter EHD-type cone 3 ″ 15.4ψ at 60 ° C

TABLE 3

Evaluation of Coated RIM Urethane

TABLE 4

Claims (4)

(A) A solvent-type coating composition based on a film-forming polyester resin and a melamine resin, which are heated at a temperature of 120 ° C. for 1 minute in a drying furnace and then measured at 60 ° C. to cause a coating having a film viscosity of 35000 poise or less; (B) an improved pore consisting of 4-20% by weight of the total solids of the polymer microparticles uniformly and stably dispersed in component (A), wherein the primer has a film viscosity of at least 35000 poise as measured at 60 ° C. Primer composition having resistance. The polycarboxylic acid according to claim 1, wherein the polyester resin is (1) a polycarboxylic acid which provides a proper midpoint potential of -250 mV or higher by non-aqueous potentiometer titration in a state in which (A) the resin acid value can be increased. A polybasic acid component consisting of a polycarboxylic acid, and (2) a polyvalent acid consisting of (C) a long chain diol having a methylene linear chain of at least 7 carbon atoms, (D) another diol and (E) a polyhydric alcohol having at least 3 hydroxyl groups. Composed of allolol component, general formula

(Wherein R represents an alkylene group having C ₄ to C ₁₀ ) and is modified by lactone, and the content of the component (C) is 3 to 15% by weight in the total resinous solid state, the component (E ) Is 5 to 50% by weight, provided that the sum of the component (C) and the lactone does not exceed the upper limit of 60% by weight of the total dendritic solid, and the resin acid value of the resin is 5 to 40, and the number 20 to 100 mole% of the carboxyl group which can increase the acid value is derived from the acid (A). The composition of claim 1 wherein the amount of polymer microparticles is from 5 to 10% by weight of the total solids of the composition. The composition of claim 1, wherein the polymer microparticles carry one or more functional groups selected from carboxyl, sulfone and hydroxyl groups on their respective particle surfaces.