JP5587653B2 - Polybutylene terephthalate material-coating material for joining metal material and polybutylene terephthalate material-coating product obtained by using the same - Google Patents

Description

  The present invention relates to a polybutylene terephthalate material-coating material for joining a metal material and a polybutylene terephthalate material-coating product for joining a metal material obtained by using the same, and in particular, a metal material intended for a predetermined polybutylene terephthalate material. The present invention relates to a paint applied to a joining surface of such a metal material and a coated product made of a metal material to which such a paint is applied.

  In recent years, electronic equipment casings such as personal computers and mobile phones have been changing from ordinary steel plates to high-tensile steel plates and aluminum alloy plates from the viewpoints of miniaturization and weight reduction, and high design characteristics. Recently, in manufacturing a personal computer casing using an aluminum alloy plate, downsizing and weight reduction are desired, and cost reduction is strongly desired.

  Specifically, in a personal computer, when fixing a printed board, HDD, or the like to the casing, a fixing jig made of a thermoplastic resin such as polybutylene terephthalate resin (hereinafter also abbreviated as PBT resin) is provided. The printed board and the like are fixed to the body through the fixing jig. In addition, the fixing jig is attached to the housing by molding the fixing jig in advance and attaching it with a fixing tool such as a screw or an adhesive. Therefore, when mounting the fixing jig using a fixture or adhesive to the housing, as described above, the fixing jig is manufactured separately in advance, and then the fixing jig is attached. Since it has to be implemented, the problem is inherent from the viewpoint of productivity, size reduction, weight reduction, and the like.

  Under such circumstances, Japanese Patent Application Laid-Open No. 2003-103563 discloses that an aluminum alloy plate that becomes a substrate of a housing is roughened by etching, and then a chemical metal surface treatment (hereinafter referred to as T treatment) is performed. After application, a method has been clarified in which the resin is poured into the surface of the substrate by the insert injection molding method, the fixing jig is directly formed on the substrate, and the substrate and the resin are integrated. . According to this method, the anchor effect that the resin bites into the surface of the roughened aluminum alloy plate is added, and a high bonding strength can be obtained. At the time of the T treatment, Since it is necessary to perform the dipping treatment, there is a problem that the cost is high, and since the resin is integrated with the roughened exposed substrate, the corrosion resistance of the remaining exposed portion is The problem of poor durability is also inherent.

  For this reason, from the viewpoint of weight reduction and cost reduction, a metal material such as an aluminum alloy plate is adopted, and a precoat coating film is formed to improve corrosion resistance and durability, and a member such as PBT resin is further formed on the surface. There is a demand for establishment of a technique capable of easily fixing and integrating the generated member to a metal material when it is provided by injection molding or the like.

  In JP-A-9-13178 and JP-A-2001-191023, a polyester polyol is mixed with a lubricant, a polyester resin, etc. together with an amino resin and / or an isocyanate compound as a curing agent. Although technologies comprising forming a pre-coated coating film have been clarified, these technologies have problems in molding processability, coating film hardness, corrosion resistance, etc., and a thermoplastic resin material such as PBT resin and a metal material It was not possible to achieve effective bonding, particularly effective fusion bonding.

  Furthermore, Japanese Patent Application Laid-Open No. 2007-320215 discloses a technique in which a thermoplastic resin such as a PBT resin is fused and bonded to a predetermined metal material such as an aluminum alloy material. A technique for forming a precoat film using a composition containing a polyester resin and an amino resin and / or an isocyanate resin and performing fusion bonding thereof has been clarified. However, even in the bonding method using such a pre-coated coating film, it is the actual situation that satisfactory bonding strength as an electronic component casing has not yet been obtained. There is a demand for establishment of a joining method that gives higher joining strength between a plastic resin material and a metal material such as an aluminum alloy plate.

JP 2003-103563 A Japanese Patent Laid-Open No. 9-13178 JP 2001-191023 A JP 2007-320215 A

  Here, the present invention has been made in the background as described above, and the problem to be solved is to firmly bond a target polybutylene terephthalate material to a predetermined bonding surface of a metal material. The object of the present invention is to provide a paint that can be squeezed and a coated product obtained by using the paint.

  And, in order to solve the above-mentioned problems, the present invention can be suitably implemented in various aspects as listed below, and each aspect described below can be implemented in any combination. Can be adopted. It should be noted that the aspects or technical features of the present invention are not limited to those described below, and can be recognized based on the inventive concept that can be grasped from the entire description. Should be understood.

(1) In order to join a polybutylene terephthalate material to a metal material, a paint applied to the joint surface of the metal material is used.
A combination of up to 80% by weight of polybutylene terephthalate resin and 20% by weight or more of a hydroxyl group-containing polyester resin, together with these two types of resins, a curing agent having a ratio of 0 to 50% by weight with respect to the hydroxyl group-containing polyester resin For polybutylene terephthalate-metal bonding, characterized in that it is prepared in such a state that it is mixed with a solvent to dissolve such a hydroxyl group-containing polyester resin, and further dissolved or finely dispersed in polybutylene terephthalate resin. paint.
(2) The polybutylene terephthalate material-metal material bonding paint according to the aspect (1), wherein the polybutylene terephthalate resin contains a fibrous or powdery inorganic filler.
(3) The polybutylene terephthalate material-metal material joint according to the aspect (1) or (2), wherein the hydroxyl group-containing polyester resin has a number average molecular weight of 8000 or more and a glass transition point of 20 ° C. or more. Paint.
(4) The polybutylene terephthalate material-metal material according to any one of the aspects (1) to (3), wherein the curing agent is selected from the group consisting of a blocked polyisocyanate compound, an amino resin, and a phenol resin. Bonding paint.
(5) The polybutylene according to any one of the aspects (1) to (4), wherein the solvent is a single solvent composed of isophorone or N-methyl-2-pyrrolidone or a mixed solvent containing the same as a main component. Terephthalate-metal paint.
(6) Any of the above aspects (1) to (5), wherein a curing catalyst is further added at a ratio of 0 to 1.0% by weight with respect to the total amount of the hydroxyl group-containing polyester resin and the curing agent. The polybutylene terephthalate material-metal material coating material according to any one of the above.
(7) The embodiments (1) to (6), wherein the polybutylene terephthalate resin is precipitated by cooling a solution obtained by dissolving in the solvent by heating and dispersed as a fine solid. ) A coating material for joining a polybutylene terephthalate material to a metal material according to any one of 1).
(8) The paint according to any one of the above aspects (1) to (7) is applied to the joint surface of the metal material to which the polybutylene terephthalate material is joined at a rate of 0.5 to 10 g / m ^2. A polybutylene terephthalate material-coating product for joining metal materials, characterized by
(9) The polybutylene terephthalate-metal-coated coating product according to the aspect (8), in which the coating film formed by the coating of the coating is heat-treated and baked.
(10) The polybutylene terephthalate-metal-coated coating product according to the aspect (8) or (9), wherein the metal material is an aluminum material made of aluminum or an alloy thereof.
(11) The polybutylene terephthalate material-metal material according to any one of the aspects (8) to (10), wherein the polybutylene terephthalate material is formed on the metal material by an injection molding operation and bonded. Paint products for bonding.

  Thus, in the polybutylene terephthalate material-metal material bonding paint according to the present invention, two resin components of a polybutylene terephthalate resin and a hydroxyl group-containing polyester resin are used for bonding the polybutylene terephthalate material and the metal material. In the liquid form in which the hydroxyl group-containing polyester resin is dissolved and the polybutylene terephthalate resin is dissolved or dispersed as fine solids or particles, the coating composition is formed. Therefore, in the presence of these two resin components, the polybutylene terephthalate material can be effectively bonded to the predetermined bonding surface of the metal material, and can be advantageously obtained as a strong integral bonded product. It was possible to do.

  In particular, when a desired polybutylene terephthalate material is obtained by bonding a predetermined polybutylene terephthalate material to a joint surface of a metal material to which the paint according to the present invention is applied, such a polybutylene terephthalate material is It is preferably formed by injection molding a polybutylene terephthalate resin under the condition that the coated metal material is inserted into the molding cavity of the molding die, in which, in such an injection molding operation, By the action of the heat of the plasticized resin, the polybutylene terephthalate material to be injection-molded and the metal material can be effectively fused and bonded, and a strongly bonded joint can be advantageously obtained. There are advantages that can be made.

  By the way, in the polybutylene terephthalate (PBT) material-metal material bonding paint according to the present invention, as well known, the PBT resin which is one of the essential components is terephthalic acid or dimethyl terephthalate and A thermoplastic and crystalline resin obtained by polycondensation using 1,4-butanediol as a main component, and various known ones are used as they are in the present invention. Moreover, in order to improve heat resistance etc., this PBT resin will contain fibrous or powdery inorganic fillers, such as glass fiber, glass bead, and powder glass. In addition, as a content of this inorganic filler, an appropriate ratio is selected as long as it does not adversely affect the paint, but it is generally included in a ratio of up to 50% by weight.

  Various PBT resins containing or not containing this inorganic filler are commercially available, for example, Toraycon 1401X06 (without filler), Toraycon 1401X04 (without filler) manufactured by Toray Industries, Inc. , Toraycon 1201G-15 (containing 15% glass fiber), Toraycon 1101G-30 (containing 30% glass fiber); NOVADURAN 5008 (without filler), NOVADURAN 5020 (without filler), manufactured by Mitsubishi Engineering Plastics Co., Ltd. NOVADURAN 5026 (containing no filler), NOVADURAN 5010G15 (containing 15% glass fiber), NOVADURAN 5010G45 (containing 45% glass fiber); DURANEX 2002 (without filler), DURANEX 2000 (manufactured by Polyplastics Co., Ltd.) Phi Over-free), DURANEX 3105 (15% glass fiber content), can be exemplified such DURANEX 3405 (45% glass fiber content), and thus is suitably selected from among them.

  Further, the hydroxyl group-containing polyester resin, which is another essential component of the paint according to the present invention, is a known polymer containing a hydroxyl group, which is a polycondensate obtained mainly from a polybasic acid component and a polyhydric alcohol component. In addition, in cooperation with the PBT resin dissolved or finely dispersed in the paint, it exhibits a better adhesion to the PBT material to be joined. In forming the dispersion, the particles can be formed more easily and the effect of stabilizing can be exhibited. In addition, as this hydroxyl-containing polyester resin, that whose number average molecular weight (Mn) is 8000 or more will be used suitably. This is because the tensile shear bond strength tends to decrease as the number average molecular weight decreases. Moreover, as a glass transition temperature (Tg) of this hydroxyl-containing polyester resin, it is desirable that it is 20 degreeC or more, Furthermore, what is 45 degreeC or more will be used more advantageously. Here, when the glass transition temperature is lower than 20 ° C., the pre-coated metal material formed by applying the paint according to the present invention, particularly when the plate-like material is stacked and stored, the anti-blocking property of these coated metal materials. This may reduce the workability and cause problems in workability and handling.

  In addition, various hydroxyl group-containing polyester resins used in the present invention as described above are commercially available, and are appropriately selected and used. For example, Byron 200 (Tg: 67 ° C., hydroxyl value: 6 KOH mg / g, Mn: 17000), Byron 290 (Tg: 72 ° C., hydroxyl value: 5 KOH mg / g, Mn: 22000), which are products of Toyobo Co., Ltd., Byron 660 (Tg: 55 ° C., hydroxyl value: 14 KOH mg / g, Mn: 8000), Byron GK880 (Tg: 84 ° C., hydroxyl value: 5 KOH mg / g, Mn: 18000), Byron BX-7000 (Tg: 60 ° C., Hydroxyl value: 2 KOH mg / g, Mn: 32000), Byron GK330 (Tg: 16 ° C., hydroxyl value: 9 KOH mg / g, Mn: 17000); Elitel UE-9200 (Tg: 65 ° C., hydroxyl value) manufactured by Unitika Ltd. : 6KOHmg / g, Mn: 15000), Elitel UE-9600 (Tg: 70 ° C, Hydroxic acid Value: 8KOHmg / g, Mn: 18000) and the like can be mentioned.

  The PBT resin and the hydroxyl group-containing polyester resin are used in combination in the paint according to the present invention so that the former is in a proportion of up to 80% by weight, and therefore the latter is in a proportion of 20% by weight or more. It will be. When the PBT resin exceeds 80% by weight in the blending ratio of these two resin components, it becomes difficult to dissolve with a solvent or the blending amount of the hydroxyl group-containing polyester resin is reduced. Insufficient dispersion causes problems that make it difficult to achieve the object of the present invention. It should be noted that the PBT resin is preferably used in a proportion of at least 5% by weight in order to more fully exert the tensile shear adhesive strength between the PBT material and the metal material joined by the paint according to the present invention. . The PBT resin and the hydroxyl group-containing polyester resin are preferably used in proportions of 5 to 70% by weight and 95 to 30% by weight.

  In the coating material according to the present invention, a known curing agent capable of curing the hydroxyl group-containing polyester resin is preferably 5 to 30% by weight in a proportion of 0 to 50% by weight with respect to the hydroxyl group-containing polyester resin. In this ratio, it is added and blended. By adding such a curing agent, the tensile shear bond strength between the bonded PBT material and the metal material can be further effectively improved. However, when the amount of such a curing agent increases, Excessive addition should be avoided because it tends to reduce adhesion. And in this invention, as such a hardening | curing agent, well-known various things, such as a blocked polyisocyanate compound, an amino resin, a phenol resin, will be used suitably, Among these, adhesive force As a curing agent that easily develops, a blocked polyisocyanate compound or an amino resin is preferably used.

  Here, the blocked polyisocyanate compound used as such a curing agent is obtained by blocking the isocyanate group of the polyisocyanate compound with a blocking agent. And as the polyisocyanate compound, for example, aromatic diisocyanate compounds such as tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate; aliphatic diisocyanate compounds such as hexamethylene diisocyanate, trimethylhexane diisocyanate; isophorone diisocyanate, hydrogenated Cycloaliphatic diisocyanate compounds such as xylylene diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate), methylcyclohexane-2,4 (or 2,6) -diisocyanate, 1,3- (isocyanatomethyl) cyclohexane; An adduct of a compound and a polyhydric alcohol, a low molecular weight polyester resin or water, or the polyisocyanate Cyclic polymers between bets compounds, further, may be mentioned isocyanate biuret like. Among these polyisocyanate compounds, aliphatic diisocyanate compounds are preferably used in terms of hygiene.

  Further, the blocking agent for blocking the polyisocyanate compound can be appropriately selected from various known blocking agents, but the drying temperature of the paint according to the present invention can be used. In view of the solvent, since it is desirable that the temperature is 200 ° C. or higher, the blocking agent is selected so that the dissociation temperature of the blocked material is 100 to 200 ° C. in order to improve the stability during paint storage. It is desirable. Examples of such blocking agents include oxime blocking agents such as formamide oxime, acetoxime, methyl ethyl ketoxime, cyclohexanone oxime, and acetoaldoxime; lactams such as ε-caprolactam, β-valerolactam, and γ-butyrolactam. Blocking agents; alcohol blocking agents such as methanol, ethanol, isopropyl alcohol, n-butyl alcohol, ethylene glycol monobutyl ether; active methylene blocking agents such as dimethyl malonate, ethyl acetoacetate, and acetylacetone I can do it.

  Blocked polyisocyanate compounds obtained by blocking isocyanate groups with this blocking agent are also commercially available from various companies. For example, Duranate 17B-60PX (solid content 60%), Duranate manufactured by Asahi Kasei Chemicals Corporation. TPA-B80E (solid content 80%), Duranate MF-B60X (solid content 60%), Duranate E402-B80T (solid content 80%); Vestagon B1530 (solid content 100%) manufactured by Degussa Japan, Vestagon B1065 ( Solid content 100%), Vesta nut B1358 (solid content 100%), Vesta nut B1370 (solid content 60%), and the like, which are appropriately selected.

  Moreover, as an amino resin which is one of the above-described curing agents, for example, urea resin, melamine resin, benzoguanamine resin and the like can be used, and more specifically, methylated urea resin, methyl etherified urea, and the like. Resin, butyl etherified urea resin, mixed etherified urea resin of methyl ether and butyl ether; melamine resin such as methylolated melamine resin, methyl etherified melamine resin, butyl etherified melamine resin, mixed etherified melamine resin of methyl ether and butyl ether; Benzoguanamine resin, methyl ether benzoguanamine resin, butyl ether benzoguanamine resin, mixed ether benzoguanamine resin of methyl ether and butyl ether, and the like. Commercially available products include, for example, Cymel 303 (solid content 100%), Cymel 235 (solid content 100%), Mycoat 506 (solid content 100%), Cymel 1123 (solid content 100%) manufactured by Nippon Cytec Industries, Ltd. ), UFR65 (solid content: 100%), UFR300 (solid content: 60%), or the like can be used.

  Furthermore, for the phenolic resin as the curing agent, a resol type phenolic resin, preferably a metacresol resin, is preferably used. For example, Sumitrite Resin PR-53893A (solid content 50 manufactured by Sumitomo Durez Co., Ltd.) %) Etc. can be used.

  In addition, the coating according to the present invention is added with the curing agent, if necessary, together with the curing agent described above, whereby the effect of the tensile shear bond strength between the PBT material and the metal material to be joined. Improvement can be achieved. In this case, an appropriate curing catalyst is appropriately selected depending on the type of curing agent used. For example, when the curing material is a blocked polyisocyanate compound, known organometallic catalysts such as tin, zirconium, aluminum and bismuth are preferably used, and amino resins and phenol resins are used as curing agents. In such a case, a known acid such as phosphoric acid or sulfonic acid is preferably used. In addition, as the addition amount, it is desirable to use in such a ratio that it is 1% by weight or less of the total amount of the hydroxyl group-containing polyester resin and the curing agent.

  And the coating material according to this invention will be prepared in a liquid form using a suitable solvent in order to apply | coat the above-mentioned PBT resin, a hydroxyl-containing polyester resin, a hardening | curing agent etc. uniformly to the metal material surface. However, since the PBT resin is used in a dissolved form and is difficult to dissolve in a solvent, it is preferably present in a form finely dispersed in the solvent, whereby the PBT resin according to the present invention is used. Effective bonding between the material and the metal material can be easily realized. Such fine dispersion of the PBT resin can be carried out by a known appropriate method. In particular, in the present invention, the PBT resin is added to a predetermined solvent and then heated. The PBT resin is dissolved in a solvent, and the obtained solution is cooled to be precipitated, so that it can be dispersed as fine solid particles, generally in a size of about 200 μm or less. It is desirable.

  In addition, as a solvent used for preparation of such a coating material, known solvents such as o-chlorophenol, dichlorobenzene, benzyl alcohol, and a phenol / tetrachloroethane mixed solvent can be used as appropriate. In particular, in the case of a single solvent, isophorone is used. Alternatively, N-methyl-2-pyrrolidone is preferably used, and the mixed solvent contains isophorone or N-methyl-2-pyrrolidone as a main component, particularly at a ratio of 60% or more, and a boiling point of 200 ° C. or more. Are preferably used. In this connection, the solvent mixed with isophorone or N-methyl-2-pyrrolidone generally has a boiling point of 200 ° C. or higher, and particularly has a solubility parameter (δ) of 9-10. For example, diethylene glycol monoethyl ether (boiling point 202 ° C., δ = 9.6), diethylene glycol (boiling point 245 ° C., δ = 9.1), DBE (DuPont products; dimethyl glutarate, dimethyl adipate and succinic acid) A mixture with dimethyl, a boiling point of 205 ° C., δ = 9.4) and the like are preferably used.

  The metal material to which the paint according to the present invention is applied as described above exhibits a predetermined shape, and is intended for various shapes such as a plate material, a shape material, and a bar material. Is done. Further, the material is preferably made of aluminum or an alloy thereof, but the same effect can be obtained even if it is made of other metal materials such as iron or steel, copper or an alloy thereof. I can do it.

Further, when applying the paint according to the present invention to the joint surface to which such a metal PBT material is to be joined, known coating techniques such as dipping, spraying, roll coating, etc. are appropriately employed, and The coating film formed by painting is dried and baked by being heated using a known heating means such as hot air drying, infrared irradiation, high frequency heating or the like. In addition, the coating film formed on the predetermined joint surface of the metal material in this way has an appropriate thickness. In the present invention, however, 0 is applied by applying the paint according to the present invention. In the thickness which becomes a ratio of 0.5-10 g / m < ² >, the target coating film will be formed. If the coating amount decreases, the bonding strength decreases and the object of the present invention cannot be sufficiently achieved. If the coating amount exceeds 10 g / m ² , cohesive failure occurs. This is because, in this case as well, the bonding strength may similarly decrease.

  And, the coating material according to the present invention is applied as described above, and the target PBT material is bonded to the metal material formed with the predetermined coating film through such a coating film. As such a PBT material, prior to the joining, when using a PBT resin molded into a predetermined shape from a PBT resin similar to the PBT resin by a known molding technique, such a PBT material is used for the paint. A method of heating and integrally joining under the condition where the joint surface of the applied metal material is pressed is adopted.

  However, in the present invention, in particular, by the insert injection molding method, the PBT material is integrally formed on the joint surface of the metal material to which the paint is applied, so that the desired integral joining is achieved. It is desirable to be able to obtain a product. That is, a coated metal material according to the present invention is set in a molding cavity, and a PBT resin similar to the PBT resin that gives the above-described paint is melted and injected to form a desired shape on the coating film on the surface of the metal material. By forming the PBT material, it is possible to effectively fuse and bond the formed PBT material to the metal material through such a coating film by effectively utilizing the heat of fusion of the resin. is there.

  Hereinafter, representative examples of the present invention will be shown to clarify the present invention more specifically, but the present invention is not limited by the description of such examples. It goes without saying. In addition to the following examples, the present invention includes various changes and modifications based on the knowledge of those skilled in the art without departing from the spirit of the present invention, in addition to the specific description described above. It should be understood that improvements can be made.

(1) Preparation of PBT resin dispersion In a 1 L flask, one each of PBT resin shown in the following Table 1, hydroxyl group-containing polyester resin shown in the following Table 2, and solvent shown in the following Table 3 was used. At a ratio shown in Table 6 below, the liquid temperature was raised while heating and stirring to dissolve the PBT resin together with the hydroxyl group-containing polyester resin. In the case of Experimental Examples 24 and 25, the melting temperature was 170 ° C., and in the case of Experimental Example 30, 155 ° C. was adopted, and all were 200 ° C. Next, by cooling the obtained resin solution, the PBT resin is finely dispersed in the hydroxyl group-containing polyester resin solution. In addition to various dispersions, the resin is completely dissolved in the solvent. A resin solution was obtained. In the case of Experimental Examples 26, 27 and 30, 31, the PBT resin could not be dissolved well and existed in a lump in the resin solution, both of which were dispersions of the target PBT resin. Could not get.

And about the obtained various PBT dispersion liquid, while measuring the viscosity at 25 degreeC with a B-type viscosity meter (a rotor uses No. 3), while the dispersion state of PBT resin in each dispersion liquid Were evaluated based on the following criteria, and the results are shown in Table 6 below.
Complete dissolution: The liquid is transparent and no dispersion is present. ○: Dispersion in which the average particle size is less than 10 μm. ○ Δ: Dispersion of dispersed particles having an average particle size of 10 to 30 μm. Δ: Average Dispersion of dispersed particles having a particle size exceeding 30 μm ×: Resin is agglomerated and not dispersed

(2) Preparation of paint Using the various dispersions obtained in the above (1), while stirring each, the curing agent and the curing catalyst shown in Table 4 and Table 5 below, respectively, as necessary, Various paints according to Experimental Examples 1 to 25 and Experimental Examples 28 and 29 were obtained under the conditions shown in Table 6 below. For Experimental Examples 26, 27 and 30, 31, since the PBT resin solution or dispersion could not be obtained, the preparation of the paint was abandoned.

(3) Evaluation of paints Using the various paints prepared in (2) above, 1.0 to 1.5 g of JIS-A5182 aluminum alloy plate having a thickness of 1.0 mm, respectively, with a bar coater. After coating to an application amount of / m ² , baking was performed in an oven at 260 ° C. (maximum temperature reached) for 30 seconds (baking time) to prepare an aluminum alloy coated plate (pre-coated plate).

  On the other hand, a granular PBT resin was used and melt-molded at a temperature of 250 ° C. according to a conventional method to produce a rectangular PBT plate having a thickness of 1 mm and a size of 10 mm × 20 mm as a PBT material.

  Next, the above-prepared aluminum alloy coated plate having a size of 20 mm × 70 mm is heated on a hot plate heated to 200 ° C. for 1 minute 50 seconds. The above-mentioned PBT resin plate is placed on an alloy coated plate having a size of 20 mm × 70 mm, heated and melted at a temperature of 260 ° C. for 2 minutes, and then immediately heated to 200 ° C. The PBT resin plate was placed on the end of the plate so as to be sandwiched, held for 15 seconds under a load of 1 kgf, then taken out from the hot plate and allowed to cool to produce various adhesion test pieces. .

  And about this obtained adhesion test piece, the end part of the two aluminum alloy coating plates which were overlap | superposed was each pulled using a tensile testing machine (tensile speed: 5 mm / min), and tensile shear adhesive strength The results are shown in Table 6 below.

  Moreover, in order to evaluate the blocking property of the various aluminum alloy coated plates obtained above, from each aluminum alloy coated plate, a rectangular sample plate of 30 mm × 30 mm size was cut out, and 10 sheets thereof were stacked, After holding for 6 hours under the conditions of pressure: 6.8 MPa and temperature: 50 ° C., it was cooled to room temperature, and each sample plate was peeled one by one by hand to evaluate the presence or absence of blocking. And, the case where no blocking is recognized is evaluated as ブ ロ ッ キ ン グ, the case where it is judged that blocking is substantially absent is evaluated as ○, and even when one of the stacked sample plates is blocking, it is evaluated as ×, and the result is evaluated. These are also shown in Table 6 below.

  As is apparent from the results of Table 6, in each paint according to Experimental Examples 1 to 25 according to the present invention, the tensile shear adhesive strength between the aluminum alloy coated plate and the PBT resin plate after each coating is as follows: It became 5 MPa or more, and it was shown that they were joined with high adhesiveness.

On the other hand, in the case of Experimental Examples 26, 27 and 30, 31, the PBT resin is not sufficiently dispersed and cannot be formed into a paint. In the case of Experimental Example 28, Since the PBT resin is not contained, the aluminum alloy coated plate and the PBT resin plate cannot be joined. Further, in the case of Experimental Example 29, since the amount of the curing agent used is large, the aluminum alloy is used. It is recognized that the bonding strength between the painted plate and the PBT resin plate is low, and therefore, the value of the tensile shear adhesive strength is low, and a practical bonded body cannot be obtained.

Claims (12)

In order to join the polybutylene terephthalate material to the metal material, the paint applied to the joint surface of the metal material,
A combination of up to 80% by weight of polybutylene terephthalate resin and 20% by weight or more of a hydroxyl group-containing polyester resin (excluding polybutylene terephthalate resin) is combined with these two resins and 0 to 50% by weight with respect to the hydroxyl group-containing polyester resin. % Is prepared by dissolving a hydroxyl group-containing polyester resin in a solvent, and further dissolving or finely dispersing a polybutylene terephthalate resin. Butylene terephthalate-metal coating material.   The polybutylene terephthalate resin-metal material coating material according to claim 1, wherein the polybutylene terephthalate resin contains a fibrous or powdery inorganic filler.   The polybutylene terephthalate material-metal material bonding paint according to claim 1 or 2, wherein the hydroxyl group-containing polyester resin has a number average molecular weight of 8000 or more and a glass transition point of 20 ° C or more. The polybutylene terephthalate material-metal material bonding paint according to any one of claims 1 to 3, wherein the hydroxyl group-containing polyester resin has a hydroxyl value of 2 to 14 KOHmg / g. The polybutylene terephthalate material-metal material bonding paint according to any one of claims 1 to 4 , wherein the curing agent is selected from the group consisting of a blocked polyisocyanate compound, an amino resin, and a phenol resin. The polybutylene terephthalate material-metal material according to any one of claims 1 to 5 , wherein the solvent is a single solvent composed of isophorone or N-methyl-2-pyrrolidone or a mixed solvent containing the same as a main component. Bonding paint. The total amount of the curing agent and the hydroxyl group-containing polyester resin, curing catalyst, further, according to any one of claims 1 to 6 is added in an amount of 0 to 1.0 wt% Polybutylene terephthalate material-metal material paint. The polybutylene terephthalate resin, the solution obtained is dissolved in the solvent by heating are caused to precipitate by cooling the any of claims 1 to 7 are dispersed as a fine solid 1 The polybutylene terephthalate material-metal material-coating material according to Item. The paint according to any one of claims 1 to 8 is applied at a rate of 0.5 to 10 g / m ^{2 on} the joint surface of the metal material to which the polybutylene terephthalate material is joined. Characteristic coating product for bonding polybutylene terephthalate to metal. 10. The coated product for bonding a polybutylene terephthalate material to a metal material according to claim 9 , wherein the coating film formed by the coating of the paint is heat-treated and baked. The polybutylene terephthalate-metal-coated coating product according to claim 9 or 10 , wherein the metal material is an aluminum material made of aluminum or an alloy thereof. The coated product for joining a polybutylene terephthalate material to a metal material according to any one of claims 9 to 11 , wherein the polybutylene terephthalate material is formed on the metal material by an injection molding operation and bonded.