JP5572935B2 - Metal cladding - Google Patents

Description

  The present invention includes, for example, rust-proof coatings for fluid metal pipes for general industrial use, rust-proof coatings for metal pipes such as steel pipes and aluminum pipes for fuel, oil, and brake fluids for automobiles, coatings for metal wires, water tank tanks, etc. The present invention relates to a metal coating material containing a novel polyamide resin, which can be used for metal coating applications such as coating of a rotating plate. Specifically, it contains polyamide resin whose dicarboxylic acid component is oxalic acid, has low water absorption, can be made high molecular weight by melt polymerization, has excellent chemical resistance and hydrolysis resistance, and has a wide molding temperature range. The present invention relates to a metal coating material having excellent properties.

  Polyamide resins typified by crystalline polyamides such as nylon 6 and nylon 66 are widely used as clothing, industrial material fibers, or general-purpose engineering plastics because of their excellent characteristics and ease of melt molding. In particular, in the coating application of a metal substrate, the adhesiveness of the polyamide resin to the metal substrate is required. In addition, these polyamide resins have been pointed out to have problems such as changes in physical properties due to water absorption, deterioration in acid, high-temperature alcohol, and hot water, resulting in a polyamide with superior dimensional stability and chemical resistance. The demand is growing.

  For example, Patent Document 1 discloses a technique for providing a polyamide resin having excellent adhesion to a metal substrate. However, in this technique, there is a problem that the property of the polyamide resin is changed, the rust of the metal base material is generated, and the adhesiveness between the metal base material and the metal coating material is likely to be lowered during long-term use due to the water absorption of the polyamide resin.

  On the other hand, a polyamide resin using oxalic acid as a dicarboxylic acid component is called a polyoxamide resin, and is known to have a higher melting point and lower water absorption than other polyamide resins having the same amino group concentration (Patent Document 2). It is expected to be used in fields where the use of conventional polyamide, where the change in physical properties due to water absorption has been a problem, is difficult.

  So far, polyoxamide resins using various aliphatic linear diamines as diamine components have been proposed. However, for example, a polyoxamide resin using 1,6-hexanediamine as a diamine component has a melting point (about 320 ° C.) higher than the thermal decomposition temperature (1% weight loss temperature in nitrogen; about 310 ° C.) (non-patent document). 1) Melt polymerization and melt molding were difficult and could not withstand practical use.

  For a polyoxamide resin whose diamine component is 1,9-nonanediamine (hereinafter abbreviated as PA92), L. Franco et al. Discloses a production method and its crystal structure when diethyl oxalate is used as the oxalic acid source ( Non-patent document 2). The PA 92 obtained here is a polymer having an intrinsic viscosity of 0.97 dL / g and a melting point of 246 ° C., but only a low molecular weight product that can not be molded into a tough molded body that can withstand practical use is obtained. Patent Document 3 shows that PA92 having an intrinsic viscosity of 0.99 dL / g and a melting point of 248 ° C. was produced when dibutyl oxalate was used as the dicarboxylic acid ester. In this case as well, there is a problem that only a low molecular weight body that cannot form a tough molded body is obtained.

The present inventors use oxalic acid as a dicarboxylic acid component, and a polyamide resin using 1,9-nonanediamine and 2-methyl-1,8-octanediamine in a specific ratio as a diamine component has low water absorption, It was disclosed that it is a polyamide resin (PA92C) having a wide melt molding temperature range and excellent properties (Patent Document 4).
However, this polyamide resin uses oxalic acid as the dicarboxylic acid component, and has a specific ratio of three diamines of 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine as the diamine component. It is not the polyoxamide resin used in 1.

S. W. Shalaby., J. Polym. Sci., 11, 1 (1973) L. Franco et al., Macromolecules., 31, 3912 (1988) JP 2004-346255 A JP 2006-57033 A Japanese National Patent Publication No. 5-506466 WO2008 / 072754

  The problem to be solved by the present invention is that a sufficiently high molecular weight is achieved, the moldable temperature range estimated from the difference between the melting point and the thermal decomposition temperature is wider, the melt moldability is excellent, and the aliphatic linear polyoxamide An object of the present invention is to provide a metal coating material excellent in chemical resistance, flexibility, hydrolysis resistance, etc. without impairing the low water absorption observed in resins.

  The inventors of the present invention have a low water-absorbing property when the dicarboxylic acid component is composed of oxalic acid and the diamine component is composed of 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine. However, it can be polymerized by melt polymerization, has a wide moldable temperature range estimated from the difference between the melting point and the thermal decomposition temperature, has excellent melt moldability, and has excellent chemical resistance, hydrolysis resistance, etc. Has already been found. As a result of extensive studies to solve the above problems, the dicarboxylic acid component is composed of oxalic acid, and the diamine component is a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine (hereinafter referred to as “C9”). A polyamide resin consisting of 1,6-hexanediamine (hereinafter also referred to as “C6 diamine”), and having a molar ratio of C9 diamine mixture to C6 diamine of 1:99 to 99: 1. By using (hereinafter also referred to as “PA92 / 62T”), it is possible to suppress the occurrence of rust of the metal base material with low water absorption and the decrease in adhesion between the metal base material and the metal coating material during long-term use, High molecular weight by melt polymerization is possible, and the moldable temperature range estimated by the difference between the melting point and the thermal decomposition temperature is as wide as, for example, 50 ° C. Found that metal coating material having excellent sex and hydrolysis resistance can be obtained, and have completed the present invention. That is, the present invention is as follows.

  [1] The dicarboxylic acid component is composed of oxalic acid, and the diamine component is a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine (hereinafter also referred to as “C9 diamine mixture”) and 1,6-hexane. A metal coating material comprising a polyamide resin comprising a diamine (hereinafter also referred to as “C6 diamine”) and having a molar ratio of the C9 diamine mixture to the C6 diamine of 1:99 to 99: 1.

  [2] The polyamide resin has a relative viscosity (ηr) of 1.8 to 6.0 when measured at 25 ° C. using a polyamide resin solution having a concentration of 1.0 g / dl using 96% sulfuric acid as a solvent. The metal coating material according to [1] above.

  [3] 1% weight loss temperature in thermogravimetric analysis of polyamide resin measured at 10 ° C./min in nitrogen atmosphere and differential scanning measured at 10 ° C./min in nitrogen atmosphere The metal coating material according to the above [1] or [2], wherein the temperature difference from the melting point measured by a calorimetric method is 50 ° C. or more.

  [4] Any of [1] to [3] above, wherein the diamine component has a molar ratio of 1,9-nonanediamine to 2-methyl-1,8-octanediamine of 5:95 to 95: 5. The metal coating | covering material as described in.

  [5] The metal coating material according to any one of [1] to [4], further including a thermoplastic elastomer.

  [6] A double bond derived from a conjugated diene compound of a block copolymer consisting of a polymer block mainly composed of a styrene compound and a polymer block mainly composed of a conjugated diene compound or a partially hydrogenated product thereof is epoxy-bonded. The metal coating material according to any one of the above [1] to [5], further comprising a epoxidized styrenic thermoplastic elastomer.

  [7] The metal coating material according to any one of [1] to [6], further including a silane coupling agent.

  [8] The metal coating material according to any one of [1] to [6], which covers a metal pipe for automobiles.

  The metal coating material of the present invention is capable of increasing the molecular weight by melt polymerization while having low water absorption, has a wide moldable temperature range estimated from the difference between the melting point and the thermal decomposition temperature, and has excellent melt moldability and chemical resistance. And because of its excellent resistance to hydrolysis, anti-corrosion coating for fluid metal pipes for general industrial use, anti-corrosion coating for metal pipes such as steel pipes and aluminum pipes for fuel, oil and brake fluids for automobiles, metal wire coating, It can be widely used as a metal coating material in metal coating applications such as coating of water-circulating plates such as water tanks.

(I) Polyamide resin (1) Constituent component of polyamide resin The polyamide resin used in the present invention is a mixture of diamine component of 1,9-nonanediamine and 2-methyl-1,8-octanediamine (hereinafter referred to as “C9 diamine mixture”). And a 6,9-hexanediamine (hereinafter also referred to as “C6 diamine”), and a molar ratio of C9 diamine mixture to C6 diamine is 1:99 to 99: 1.

  As the oxalic acid source used in the production of the polyamide resin, oxalic acid diesters can be employed, and there is no particular limitation as long as they have reactivity with amino groups. Dimethyl oxalate, diethyl oxalate, di-n-oxalate (or i-) oxalic acid diesters of aliphatic monohydric alcohols such as propyl, di-n- (or i-, or t-) butyl oxalate, oxalic acid diesters of alicyclic alcohols such as dicyclohexyl oxalate, and aromatic alcohols such as diphenyl oxalate Examples include oxalic acid diesters.

  Among the above oxalic acid diesters, oxalic acid diesters of aliphatic monohydric alcohols having more than 3 carbon atoms, oxalic acid diesters of alicyclic alcohols, and oxalic acid diesters of aromatic alcohols are preferred, and among them, dibutyl oxalate and diphenyl oxalate are particularly preferred.

  The molar ratio of the 1,9-nonanediamine component to the 2-methyl-1,8-octanediamine component in the C9 diamine mixture used in the polyamide resin of the present invention is generally 1:99 to 99: 1, preferably 5:95 to 95: 5, more preferably 5:95 to 40:60 or 60:40 to 95: 5, especially 5:95 to 30:70 or 70:30 to 90:10. By copolymerizing 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine in the above specific amounts, the moldable temperature range is wide, the melt moldability is excellent, and the water absorption is low. Polyamide having excellent properties, chemical resistance, hydrolysis resistance, transparency and the like can be obtained.

  In the polyamide resin of the present invention, as the diamine component, the C9 diamine mixture (1,9-nonanediamine and 2-methyl-1,8-octanediamine) mixed with 1,6-hexanediamine is used. The molar ratio of C9 diamine mixture to 1,6-hexanediamine is 1:99 to 99: 1. By mixing 1,6-hexanediamine in a molar ratio of 1/99 or more with respect to the C9 diamine mixture, the above excellent effect of the polyamide resin (PA92C) comprising oxalic acid as the dicarboxylic acid component and C9 diamine mixture as the diamine component Can be maintained (particularly without impairing melt moldability and low water absorption), the melting point of the polyamide resin can be increased, and particularly the mechanical properties can be improved. The molar ratio of the C9 diamine mixture to 1,6-hexanediamine is preferably 5.1: 94.9 to 99: 1, more preferably 10:90 to 99: 1, and even more preferably 20:80 to 99: 1. It is. In particular, it is preferably 30:70 to 98: 2, and more preferably 30:70 to 90:10 (further 30:70 to 70:30). In this polyamide resin, the change to the melting point appears clearly by copolymerizing 1,6-hexanediamine in a molar ratio of 1/99 or more with respect to the C9 diamine mixture, and the melting point of the resin rises. If 6-hexanediamine is within a molar ratio of 99/1, an acceptable melt moldability can be obtained. If the molar ratio of 1,6-hexanediamine is within 80/20, the melting point of the polyamide resin will be 300 ° C. or lower, and polymerization and molding (melt moldability) will be easier, and within 70/30. It is more preferable because the melting point becomes 280 ° C. or lower and the melt moldability becomes easier.

(2) Components that can be blended in the production of polyamide resin When producing the polyamide resin used in the present invention, other dicarboxylic acid components can be mixed within a range not impairing the effects of the present invention. Examples of dicarboxylic acid components other than succinic acid include malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, 2,2-dimethylglutaric acid, 3, Aliphatic dicarboxylic acids such as 3-diethylsuccinic acid, azelaic acid, sebacic acid and suberic acid, alicyclic dicarboxylic acids such as 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid, and terephthalic acid , Isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,4-phenylenedioxydiacetic acid, 1,3-phenylenedioxydiacetic acid, dibenzoic acid Acid, 4,4′-oxydibenzoic acid, diphenylmethane-4,4′-dicarboxylic acid, diphenylsulfuric acid Down-4,4'-dicarboxylic acid, 4,4'-biphenyl and the like alone aromatic dicarboxylic acids such as dicarboxylic acids, or may be added to any mixture thereof during the polycondensation reaction. Furthermore, polyvalent carboxylic acids such as trimellitic acid, trimesic acid and pyromellitic acid can be used as long as melt molding is possible. It is preferable that the usage-amount of another dicarboxylic acid component is 5 mol% or less of the whole dicarboxylic acid component.

  Moreover, when manufacturing the polyamide resin used in this invention, another diamine component can be mixed in the range which does not impair the effect of this invention. Other diamine components other than 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine include ethylenediamine, propylenediamine, 1,4-butanediamine, and 1,8-octanediamine. 1,10-decanediamine, 1,12-dodecanediamine, 3-methyl-1,5-pentanediamine, 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1 , 6-hexanediamine, aliphatic diamines such as 5-methyl-1,9-nonanediamine, cyclohexanediamine, methylcyclohexanediamine, isophoronediamine and other alicyclic diamines, p-phenylenediamine, m-phenylenediamine, p -Xylenediamine, m-xylenediamine, 4,4'-diamy Diphenylmethane, 4,4'-diaminodiphenyl sulfone, 4,4'-and aromatic diamines, such as diaminodiphenyl ether by itself, or may be added to any mixture thereof during the polycondensation reaction. It is preferable that the usage-amount of another diamine component is 5 mol% or less of the whole diamine component.

  The polyamide resin used in the present invention may be one in which a part thereof is replaced with another polymer component as long as the effects of the present invention are not impaired. As other polymer components, the dicarboxylic acid component is composed of oxalic acid, the diamine component is composed of 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine, and a C9 diamine mixture (1 , 9-nonanediamine and 2-methyl-1,8-octanediamine) and 1,6-hexanediamine in a molar ratio of 1:99 to 99: 1 as polyamides other than polyamides, polyoxamides, aromatic polyamides, fats And polyamides such as aromatic polyamides and alicyclic polyamides, and thermoplastic polymers other than polyamides. In the polyamide resin used in the present invention, the dicarboxylic acid component is composed of oxalic acid, the diamine component is composed of 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine, and a C9 diamine mixture. The proportion of polyamide in which the molar ratio of (1,9-nonanediamine and 2-methyl-1,8-octanediamine) to 1,6-hexanediamine is from 1:99 to 99: 1 is more than 50% by mass, and more than 70%. The mass% or more is preferable.

(3) Properties and properties of polyamide resin The molecular weight of the polyamide resin used in the present invention is not particularly limited, but the relative viscosity measured at 25 ° C. using a 96% concentrated sulfuric acid solution with a polyamide resin concentration of 1.0 g / dl. ηr is preferably in the range of 1.8 to 6.0, more preferably 2.0 to 5.5, and particularly preferably 2.5 to 4.5. If ηr is lower than 1.8, the molded product tends to be brittle and the physical properties tend to decrease. On the other hand, when ηr is higher than 6.0, the melt viscosity becomes high and the molding processability tends to deteriorate.

  The polyamide resin used in the present invention uses oxalic acid as the dicarboxylic acid component and oxalic acid by copolymerizing 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine as the diamine component. It is possible to increase the relative viscosity, that is, to increase the molecular weight, as compared with a polyamide comprising 1,9-nonanediamine. The moldable temperature range represented by the difference (Td−Tm) between the 1% weight loss temperature (hereinafter abbreviated as Td) and the melting point (hereinafter abbreviated as Tm), which is a substantial thermal decomposition index, is oxalic acid. And a moldable temperature range can be preferably 50 ° C. or higher, more preferably 60 ° C. or higher, and even 90 ° C. or higher. The polyamide resin used in the present invention has a Td of preferably 280 ° C. or higher, more preferably 300 ° C. or higher, still more preferably 320 ° C. or higher, and has high heat resistance.

(4) Manufacture of polyamide resin The polyamide resin used in the present invention can be manufactured using any method known as a method of manufacturing polyamide. According to the study by the present inventors, a polyamide resin can be obtained by polycondensation reaction of diamine and oxalic acid diester in a batch or continuous manner. Specifically, it is preferable to carry out in the order of (i) pre-polycondensation step and (ii) post-polycondensation step as shown by the following operations.

  (I) Pre-polycondensation step: First, the inside of the reactor is purged with nitrogen, and then diamine (diamine component) and oxalic acid diester (oxalic acid source) are mixed. When mixing, a solvent in which both the diamine and the oxalic acid diester are soluble may be used. The solvent in which both the diamine component and the oxalic acid source are soluble is not particularly limited, but toluene, xylene, trichlorobenzene, phenol, trifluoroethanol, and the like can be used, and particularly, toluene can be preferably used. For example, after heating the toluene solution which melt | dissolved diamine to 50 degreeC, oxalic acid diester is added with respect to this. At this time, the charging ratio of the oxalic acid diester and the diamine is oxalic acid diester / the diamine, 0.8 to 1.5 (molar ratio), preferably 0.91 to 1.1 (molar ratio), more preferably 0. .99 to 1.01 (molar ratio).

  The temperature in the reactor charged in this way is increased under normal pressure while stirring and / or nitrogen bubbling. The reaction temperature is preferably controlled so that the final temperature reaches 80 to 150 ° C., preferably 100 to 140 ° C. The reaction time at the final temperature is, for example, 3 to 6 hours.

  (Ii) Post-polycondensation step: In order to further increase the molecular weight, the polymer produced in the pre-polycondensation step is gradually heated in the reactor under normal pressure. In the temperature rising process, the final temperature of the prepolycondensation step, that is, from 80 to 150 ° C, is finally 220 ° C to 300 ° C, preferably 230 ° C to 280 ° C, more preferably 240 ° C to 270 ° C. Let reach the range. It is preferable to carry out the reaction for 1 to 8 hours including the temperature raising time, preferably 2 to 6 hours. Furthermore, in the post-polymerization step, polymerization can be performed under reduced pressure as necessary. The preferable final ultimate pressure in the case of performing the vacuum polymerization is less than 0.1 MPa to 13.3 Pa.

The specific example of the manufacturing method of the polyamide resin used for this invention is demonstrated.
First, the raw oxalic acid diester is charged into the container. The container is not particularly limited as long as it can withstand the temperature and pressure of the polycondensation reaction to be performed later. Thereafter, the container is heated to a temperature at which it is mixed with the raw material diamine, and then the diamine is injected to start the polycondensation reaction. The temperature at which the raw materials are mixed is not particularly limited as long as it is a temperature not lower than the boiling point and lower than the boiling point of the oxalic acid diester and diamine, and the polyoxamide generated by the polycondensation reaction of the oxalic acid diester and diamine is not thermally decomposed. For example, a mixture of 1,9-nonanediamine, 2-methyl-1,8-octanediamine, 1,6-hexanediamine, and a C9 diamine mixture (1,9-nonanediamine and 2-methyl-1,8-octane) In the case of a polyoxamide resin made from diamine and dibutyl oxalate having a molar ratio of a mixture of diamines) and 1,6-hexanediamine of 1:99 to 99: 1, the mixing temperature is preferably 15 ° C to 300 ° C. When the molar ratio of C9 diamine mixture (1,9-nonanediamine and 2-methyl-1,8-octanediamine mixture) and 1,6-hexanediamine is 5:95 to 90:10, it is liquid at room temperature. Or it is more preferable because it is easy to handle because it liquefies only by heating to about 50 ° C. When the mixing temperature is equal to or higher than the boiling point of the alcohol produced by the condensation reaction, it is desirable to use a container equipped with a device for distilling and condensing the alcohol. In addition, when pressure polymerization is performed in the presence of an alcohol generated by a condensation reaction, a pressure vessel is used. The charging ratio of oxalic acid diester to diamine is oxalic acid diester / the above diamine, 0.8 to 1.2 (molar ratio), preferably 0.91 to 1.09 (molar ratio), more preferably 0.98 to 1. 0.02 (molar ratio).

  Next, the inside of the container is heated to a temperature not lower than the melting point of the polyoxamide resin and not higher than the temperature at which it does not decompose. For example, it consists of 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine, and a C9 diamine mixture (of 1,9-nonanediamine and 2-methyl-1,8-octanediamine). A mixture) and a 1,6-hexanediamine molar ratio of 50:50, and a 1,9-nonanediamine and 2-methyl-1,8-octanediamine molar ratio of 50:50 diamine and dibutyl oxalate. In the case of the polyoxamide resin used as a raw material, the melting point is 261 ° C., so it is preferable to raise the temperature from 270 ° C. to 300 ° C. (pressure is 2 MPa to 4 MPa). While distilling off the produced alcohol, the polycondensation reaction is continued under an atmospheric pressure of nitrogen or reduced pressure as necessary. When the raw materials are mixed in a pressure vessel and subjected to pressure polymerization in the presence of an alcohol produced by a condensation reaction, the pressure is first released while the produced alcohol is distilled off. Thereafter, the polycondensation reaction is continued under an atmospheric pressure of nitrogen or reduced pressure as necessary. The preferable final pressure in the case of carrying out the vacuum polymerization is 760 to 0.1 Torr. The temperature is preferably 270 to 300 ° C. The alcohol is cooled and liquefied by a water-cooled condenser and recovered.

(II) Other components In the present invention, various additives can be combined as necessary in addition to the above-mentioned polyamide resin, and these can be combined during or after the polyamide polycondensation reaction. .

  Various additives include adhesion improvers, fillers, reinforcing fibers, stabilizers such as copper compounds, colorants, UV absorbers, light stabilizers, antioxidants, antistatic agents, flame retardants, and crystallization accelerators. , Glass fiber, plasticizer, lubricant, heat-resistant agent and the like.

  When forming the metal coating material of this invention on a metal base material, for example without a primer, it is preferable that a metal coating material further contains an adhesive improvement agent. As the adhesion improver, conventionally known ones can be used, and examples thereof include thermoplastic elastomers, particularly epoxidized styrene elastomers, modified polyolefins, and further silane coupling agents.

  Examples of the epoxidized styrene elastomer include a polymer block mainly composed of a styrene compound and a conjugated diene compound or a partially hydrogenated product thereof as described in, for example, the above-mentioned JP-A No. 2004-346255. An epoxidized styrene thermoplastic elastomer obtained by epoxidizing a double bond derived from a conjugated diene compound of a block copolymer comprising a polymer block (hereinafter referred to simply as an epoxidized styrene thermoplastic elastomer) As long as it refers to the above).

  The styrene compound is selected from, for example, styrene, α-methylstyrene, vinyltoluene, p-tertiary butylstyrene, divinylbenzene, p-methylstyrene, 1,1-diphenylstyrene, vinylnaphthalene, vinylanthracene and the like. 1 type or 2 types or more can be illustrated, and styrene is preferable among them.

  Examples of the conjugated diene compound include butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, piperylene, 3-butyl-1,3-octadiene, phenyl-1,3- One or more types selected from butadiene and the like can be exemplified, and butadiene, isoprene and a combination thereof are particularly preferable.

  The content of the structural unit derived from the styrenic compound in the block copolymer is preferably 5 to 70% by mass, and more preferably 10 to 60% by mass. The block copolymer preferably has a weight average molecular weight of 5,000 to 600,000, more preferably 10,000 to 500,000, and a molecular weight distribution [weight average molecular weight (Mw). And the ratio of the number average molecular weight (Mn) (Mw / Mn)] is preferably 10 or less.

  The molecular structure of the block copolymer is preferably linear. In addition, the styrene compound (A) and the conjugated diene compound (B) have a structure such as ABA, BABA, ABBABA, or the like. A compound-conjugated diene compound block copolymer is preferred. The block copolymer may have a polyfunctional coupling agent residue at the molecular end.

  The manufacturing method of the block copolymer may be any manufacturing method as long as the block copolymer having the above-described structure is obtained. For example, a styrenic resin in an inert solvent using a lithium catalyst or the like by the method described in JP-B-40-23798, JP-B-43-17799, JP-B-46-32415, and JP-B-56-28925. A compound-conjugated diene compound block copolymer can be produced. Further, hydrogenation is carried out in the presence of a hydrogenation catalyst in an inert solvent by the method described in JP-B-42-8704, JP-B-43-6636, or JP-A-59-133203. A partially hydrogenated block copolymer which is a raw material for the epoxy-modified block copolymer used in the invention can be produced. The degree of hydrogenation can be determined by NMR analysis of the block copolymer before and after hydrogenation. The hydrogenation rate is defined as the percentage of hydrogenated double bonds derived from the conjugated diene compound of the unhydrogenated / epoxidized raw material block copolymer. In the present invention, the hydrogenation rate is preferably in the range of 0 to 80%, particularly preferably in the range of 10 to 70%. Within this range, an epoxidized styrene thermoplastic elastomer excellent in heat resistance and cohesiveness can be obtained.

  Epoxidized styrene thermoplastic elastomer can be obtained by epoxidizing the block copolymer. For example, it can be obtained by reacting the block copolymer with an epoxidizing agent such as hydroperoxides and peracids in an inert solvent.

  The inert solvent is used for the purpose of lowering the raw material viscosity and stabilizing by dilution of the epoxidizing agent, and for example, hexane, cyclohexane, toluene, benzene, ethyl acetate, carbon tetrachloride, chloroform and the like can be used.

  Among the epoxidizing agents, examples of hydroperoxides include hydrogen peroxide, tertiary butyl hydroperoxide, cumene hydroperoxide, and the like. Examples of “peracids” include performic acid, peracetic acid, perbenzoic acid, trifluoroperacetic acid and the like. Among them, peracetic acid is preferred because it is produced industrially in large quantities, can be obtained at low cost, and has high stability. The amount of the epoxidizing agent is not strictly limited, and can be changed depending on the individual epoxidizing agent used, the desired degree of epoxidation, and the difference in the properties of the individual block copolymers used.

  In the epoxidation, a catalyst can be used as necessary. For example, in the case of peracids, an alkali such as sodium carbonate or an acid such as sulfuric acid can be used as a catalyst. On the other hand, in the case of hydroperoxides, a catalytic effect is obtained by using a mixture of tungstic acid and caustic soda with hydrogen peroxide, organic acid with hydrogen peroxide, or molybdenum hexacarbonyl with tertiary butyl hydroperoxide. be able to.

  The epoxidation reaction conditions are not strictly limited, but, for example, peracetic acid is preferably 0 to 70 ° C. This is because decomposition of peracetic acid occurs when the temperature exceeds 70 ° C. No special operation is required for the reaction mixture. For example, the mixture of raw materials may be stirred for 2 to 10 hours. The reaction temperature of epoxidation can be changed according to the reactivity of the epoxidizing agent used in accordance with a conventional method.

  Isolation of the obtained epoxidized styrenic thermoplastic elastomer includes, for example, a method of precipitating with a poor solvent, a method of adding the epoxidized styrenic thermoplastic elastomer into hot water with stirring and distilling off the solvent, heating and The solvent can be directly dried by a decompression operation or the like. Moreover, when finally utilizing by a solution form, it can also be used without isolating.

  The epoxidation rate of the epoxidized styrene thermoplastic elastomer is preferably 10 to 40%, particularly preferably 15 to 35%. If the amount of the epoxy group is less than 10%, the effect of the present invention tends to be reduced. On the other hand, if the amount exceeds 40%, the reaction activity of the epoxy group becomes too high and gelation tends to occur, and the thermal stability decreases. Tend to. In addition, particularly when thermal stability is required, it is preferable that the double bond derived from the conjugated diene compound remaining unsaturated without being hydrogenated or epoxidized is less than 90% of the total, Particularly preferred is 40% or less.

  The epoxidation rate of the epoxidized styrene thermoplastic elastomer is the percentage of epoxidized double bonds derived from the conjugated diene compound of the raw hydrogenated / non-epoxidized raw material block copolymer, and the epoxy equivalent (N) can be represented by the formula: epoxidation rate = {10000 × D + 2 × H × (100−S)} / {(N−16) × (100−S)} (D is a conjugated diene compound) The molecular weight, H is the hydrogenation rate (%), and S is the content (% by weight) of the styrene compound. The epoxy equivalent (N) of the epoxidized styrenic thermoplastic elastomer that can be preferably used in the present invention is titrated with 0.1 N hydrobromic acid, and the formula: epoxy equivalent (N) = 10000 × W / (f × V ) (W is the weight (g) of the epoxidized styrenic thermoplastic elastomer used for the titration, V is the titration amount of hydrobromic acid (ml), and f is the hydrobromic acid factor) be able to.

  3-30 mass parts is preferable with respect to 100 mass parts of polyamide resins, as for the compounding quantity of an epoxidized styrene-type thermoplastic elastomer, 3-28 mass parts is more preferable, and its 3-25 mass parts is especially preferable. In the case of 3 parts by mass or more, the adhesion between the metal base material and the metal coating material is particularly good, and in the case of 30 parts by mass or less, the mechanical characteristics and surface characteristics of the polyamide resin are impaired. hard.

  On the other hand, a silane coupling agent chemically bonds an organic functional group having affinity or reactivity to an organic resin to a hydrolyzable silyl group having affinity or reactivity to an inorganic material. It is a silane compound having a different structure. Examples of the hydrolyzable group bonded to silicon include an alkoxy group, a halogen, and an acetoxy group. Usually, an alkoxy group, particularly a methoxy group and an ethoxy group are preferably used. The number of hydrolyzable groups attached to one silicon atom is selected between 1 and 3. Examples of the organic functional group include an amino group, an epoxy group, a vinyl group, a carboxyl group, a mercapto group, a halogen group, a methacryloxy group, and an isocyanate group, and preferably an amino group or an epoxy group.

  Specific examples of the silane coupling agent include α-aminoethyltriethoxysilane, α-aminopropyltriethoxysilane, α-aminobutyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane N-β- (aminoethyl) -γ-aminopropyltriethoxysilane, γ-ureidopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-benzyl- γ-aminopropyltrimethoxy Amino group-containing silanes such as silane and N-vinylbenzyl-γ-aminopropyltriethoxysilane; γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycosoxypropyltriethoxy Epoxy group-containing silanes such as silane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane; vinyl Vinyl group-containing silanes such as trimethoxysilane, vinyltriethoxysilane and vinylmethyldimethoxysilane; β-carboxyethyltriethoxysilane, β-carboxyethylphenylbis (2-methoxyethoxy) silane, N-β- (N- Carboxymethyl amino Carboxyl group-containing silanes such as ethyl) -γ-aminopropyltrimethoxysilane; γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane Mercapto group-containing silanes such as γ-halogen-containing silanes such as γ-chloropropyltrimethoxysilane; γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-acryloxypropyltrimethoxysilane, γ -(Meth) acrylic group-containing silanes such as methacryloxypropylmethyldimethoxysilane and γ-methacryloxypropylmethyldiethoxysilane; γ-isocyanatopropyltrimethoxysilane, γ-isocyanate Over preparative triethoxysilane, .gamma. isocyanate propyl methyl diethoxy silane, isocyanate group-containing silanes such as .gamma. isocyanate propyl methyl dimethoxysilane and the like.

  The amount of the silane coupling agent is preferably 0.01 to 0.5 parts by mass and more preferably 0.01 to 0.3 parts by mass with respect to 100 parts by mass of the polyamide resin described above. When the amount is 0.01 parts by mass or more, the adhesion of the metal coating material to the metal substrate is particularly good, and when it is 0.5 parts by mass or less, the fluidity and surface characteristics of the polyamide resin are impaired. It's difficult.

  When the above-mentioned epoxidized styrenic thermoplastic elastomer and the above-mentioned silane coupling agent are used in combination, the adhesion between the metal substrate and the metal coating material of the present invention is particularly good and preferable.

(III) Formation of metal coating material The metal coating material of the present invention can be applied to a wide range of metal substrates such as non-ferrous metals such as aluminum and iron. Applications of metal coating materials include rust-proof coating for fluid metal pipes for general industrial use, rust-proof coating for metal pipes such as steel pipes and aluminum pipes for automobile fuel, oil, brake fluid, etc., metal wire coating, water tank Examples thereof include coating of a water plate such as a tank, and can be preferably applied particularly to a metal pipe for automobiles.

  The method of coating the metal substrate with the metal coating material of the present invention is not limited to these methods. For example, it is an adherend with a polyamide resin composition that is already in a molten state, such as a steel pipe coating by extrusion. A method of coating a metal substrate, a method of coating a metal substrate by heating a metal substrate that is an adherend, such as powder coating, and melting a solid polyamide resin composition by the heat, And the method etc. which heat and coat | cover the thing which made the metal base material and the polyamide resin composition of a solid state contact are mentioned. Prior to coating with the metal coating material of the present invention, the metal substrate may be subjected to primer treatment using a conventionally known primer for metal.

  In forming the metal coating material, the temperature of the polyamide resin composition is preferably maintained at a temperature that does not alter the polyamide resin composition.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated, this invention is not limited to these Examples.

[Physical property measurement, molding, evaluation method]
The characteristic value was measured by the following method.

(1) Relative viscosity (ηr)
ηr was measured at 25 ° C. with an Ostwald viscometer using a 96% sulfuric acid solution of polyamide (concentration: 1.0 g / dl).

(2) Melting point (Tm) and crystallization temperature (Tc)
Tm and Tc were measured under a nitrogen atmosphere using a PYRIS Diamond DSC manufactured by PerkinELmer. The temperature was raised from 30 ° C. to 300 ° C. at a rate of 10 ° C./min (referred to as a temperature rise first run), held at 300 ° C. for 3 minutes, and then lowered to −100 ° C. at a rate of 10 ° C./min (temperature fall first). Then, the temperature was raised to 300 ° C. at a rate of 10 ° C./min (called a temperature rising second run). From the obtained DSC chart, the exothermic peak temperature of the temperature decrease first run was Tc, and the endothermic peak temperature of the temperature increase second run was Tm.

(3) 1% weight loss temperature (Td)
Td was measured by thermogravimetric analysis (TGA) using THERMOGRAVIMETRIC ANALYZER TGA-50 manufactured by Shimadzu Corporation. The temperature was raised from room temperature to 500 ° C. at a rate of 10 ° C./min under a nitrogen stream of 20 ml / min, and Td was measured.

(4) Melt viscosity Melt viscosity was measured by attaching a 25mm cone plate to a melt viscoelasticity measuring device ARES manufactured by TA Instruments Japan Co., Ltd. Measured under conditions.

(5) Film formation A film was formed from the pellets using a vacuum press TMB-10 manufactured by Toho Machinery Co., Ltd. After heating and melting at 290 ° C. in a reduced pressure atmosphere of 500 to 700 Pa (260 ° C. when using PA6, 290 ° C. when using PA66, 230 ° C. when using PA12) for 5 minutes, 1 at 5 MPa The film was formed by pressing for a minute. Next, the reduced-pressure atmosphere was returned to normal pressure, and then cooled and crystallized at room temperature of 5 MPa for 1 minute to obtain a film.

(6) Saturated water absorption rate A film (dimensions: 20 mm × 10 mm, thickness 0.25 mm; mass of about 0.05 g) formed under the conditions of (5) above is immersed in ion-exchanged water at 23 ° C., and every predetermined time. The film was taken out and the mass of the film was measured. When the rate of increase in the film mass lasts 3 times within the range of 0.2%, it is judged that the absorption of moisture into the polyamide resin film has reached saturation, and the mass (Xg) of the film before being immersed in water The saturated water absorption (%) was calculated from the mass (Yg) of the film when reaching saturation with the following equation (1).

  Saturated water absorption (%) = (Y−X) / X × 100 (1)

(7) Chemical Resistance After the polyamide hot press film obtained according to the present invention was immersed in the following chemicals for 7 days, changes in mass residual rate (%) and appearance of the film were observed. Tests were conducted on samples immersed in concentrated hydrochloric acid, 64% sulfuric acid, and glacial acetic acid at 23 ° C.

(8) Hydrolysis resistance The film molded under the condition (5) above is put in an autoclave, and in water, 0.5 mol / l sulfuric acid, 1 mol / l sodium hydroxide aqueous solution (that is, pH = 7, pH = 1, pH = 14), and the mass residual ratio (%) after treatment at 121 ° C. for 60 minutes was examined.

(9) Mechanical properties The following test specimens were measured at a resin temperature of 290 ° C (260 ° C when using PA6, 290 ° C when using PA66, 230 ° C when using PA12), Molding was carried out by injection molding at a mold temperature of 80 ° C.

  [1] Tensile yield strength: Measured according to ASTM D638 using a Type I test piece described in ASTM D638.

  [2] Flexural modulus: Measured at 23 ° C. in accordance with ASTM D790 using a test piece with a test piece size of 3.2 mm × 12.7 mm × 127 mm. What was evaluated without humidity adjustment after molding was described in the table as dry, and what was evaluated after conditioning at 23 ° C. and 65% humidity after molding was shown in the table.

  [3] Izod impact strength: Measured at 23 ° C. in accordance with ASTM D256 using a test piece with a test piece size of 3.2 mm × 12.7 mm × 127 mm.

  [4] Deflection temperature under load (thermal deformation temperature): Measured at a load of 1.82 MPa in accordance with ASTM D648 using a test piece having a test piece size of 3.2 mm × 12.7 mm × 127 mm.

(10) Water absorption rate A film (dimensions: 20 mm × 10 mm, thickness 0.25 mm; mass of about 0.05 g) formed under the condition (5) above is placed under conditions of 23 ° C. and 65% RH, and the film is taken every predetermined time Was taken out and the mass of the film was measured. When the rate of increase in the film mass continues three times within the range of 0.2%, it is determined that the absorption of moisture into the polyamide resin film has reached saturation, and before the 23 ° C. and 65% RH conditions are satisfied. The water absorption rate (%) was calculated from the mass (Xg) of the film and the mass (Yg) of the film when saturation was reached by the following formula (2).

  Water absorption (%) = (Y−X) / X × 100 (2)

(11) Adhesive force A 150 mm × 100 mm film with a thickness of 0.1 mm prepared under the conditions in (5) above is a metal plate with a side of 150 mm and a thickness of 0.5 mm (galvanized steel sheet: JIS G3302 SPGC Z22, aluminum plate: JIS No. 1100) Scissors with two sheets, heat-melted at 260 ° C. for 5 minutes in a reduced pressure atmosphere of 500 to 700 Pa using a vacuum press machine TMB-10 manufactured by Toho Machinery Co., Ltd., then pressed at 10 MPa for 1 minute to form a film did. Next, after returning the reduced pressure atmosphere to normal pressure, the sample was cooled at room temperature of 5 MPa for 1 minute to obtain a sample. The sample was cut at a width of 25 mm, and a T-type peel test was performed according to JIS K-6683. The adhesive strength was evaluated by the energy required to completely peel the peak strength and the width of 25 mm × 100 mm.

[Production Example 1: PA92 / 62T-1]
Oxalic acid in a pressure vessel with an internal volume of about 150 liters equipped with a stirrer, thermometer, torque meter, pressure gauge, raw material inlet directly connected to the diaphragm pump, nitrogen gas inlet, pressure outlet, pressure regulator and polymer outlet The operation of charging 28.230 kg (139.56 mol) of dibutyl, pressurizing the inside of the pressure vessel to 0.5 MPa with nitrogen gas having a purity of 99.9999%, and then releasing nitrogen gas to normal pressure is performed 5 times. After repeated nitrogen substitution, the system was heated while stirring under a sealing pressure. After the temperature of dibutyl oxalate was raised to 100 ° C. over about 30 minutes, 1.241 kg (7.84 mol) of 1,9-nonanediamine and 19.639 kg (124.04 mol) of 2-methyl-1,8-octanediamine were obtained. And a mixture of 0.893 kg (7.68 mol) of 1,6-hexanediamine (molar ratio of 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine is 5.62: 88.88: 5.50) was supplied into the reaction vessel by a diaphragm pump at a flow rate of 1.49 liters / minute for about 17 minutes, and at the same time the temperature was raised. The internal pressure in the pressure vessel immediately after the supply increased to 0.35 MPa by butanol generated by the polycondensation reaction, and the temperature of the polycondensate increased to about 170 ° C. Thereafter, the temperature was raised to 235 ° C. over 1 hour. Meanwhile, the internal pressure was adjusted to 0.75 MPa while extracting the generated butanol from the pressure relief port. Immediately after the temperature of the polycondensate reached 235 ° C., butanol was extracted from the pressure release port over about 20 minutes, and the internal pressure was brought to normal pressure. From the normal pressure, the temperature was raised while flowing nitrogen gas at 1.5 liters / minute, the temperature of the polycondensate was brought to 260 ° C. over about 1 hour, and the reaction was carried out at 260 ° C. for 4.5 hours. . Thereafter, stirring was stopped, the inside of the system was pressurized to 1 MPa with nitrogen and allowed to stand for about 10 minutes, then released to an internal pressure of 0.5 MPa, and the polycondensate was extracted in a string form from the lower outlet of the pressure vessel. The string-like polymer was immediately cooled with water, and the water-cooled string-like resin was pelletized with a pelletizer. The obtained polyamide was a white tough polymer, and ηr = 3.13.

[Production Example 2: PA92 / 62T-2]
28.462 kg (140.71 mol) of dibutyl oxalate was charged, 16.448 kg (103.88 mol) of 1,9-nonanediamine, 2.903 kg (18.34 mol) of 2-methyl-1,8-octanediamine and 1 , 6-hexanediamine 2.150 kg (18.50 mol) (mixture ratio of 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine is 73.83: 13.13. 03: 13.14) was reacted in the same manner as in Production Example 1 to obtain polyamide. The obtained polyamide was a white tough polymer with ηr = 2.97.

[Production Example 3: PA92 / 62T-3]
30.238 kg (149.49 mol) of dibutyl oxalate was charged, 4.486 kg (28.33 mol) of 1,9-nonanediamine, 4.486 kg (28.33 mol) of 2-methyl-1,8-octanediamine and 1 , 6-hexanediamine 10.79 kg (92.85 mol) (1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine molar ratio of 18.95: 18. 95: 62.10) was supplied into the reaction vessel with a diaphragm pump at a flow rate of 1.49 liters / minute over about 17 minutes, and at the same time the temperature was raised. The internal pressure in the pressure vessel immediately after the supply increased to 0.35 MPa by butanol generated by the polycondensation reaction, and the temperature of the polycondensate increased to about 170 ° C. Thereafter, the temperature was raised to 270 ° C. over 1.5 hours. Meanwhile, the internal pressure was adjusted to 1.00 MPa while extracting the generated butanol from the pressure relief port. Immediately after the temperature of the polycondensate reached 270 ° C., butanol was extracted from the pressure release port over about 20 minutes, and the internal pressure was brought to normal pressure. From the normal pressure, the temperature was raised while flowing nitrogen gas at 1.5 liters / minute, the temperature of the polycondensate was changed to 285 ° C. over about 1 hour, and the reaction was carried out at 285 ° C. for 1.5 hours. . Thereafter, stirring was stopped, the inside of the system was pressurized to 1 MPa with nitrogen and allowed to stand for about 10 minutes, then released to an internal pressure of 0.5 MPa, and the polycondensate was extracted in a string form from the lower outlet of the pressure vessel. The string-like polymer was immediately cooled with water, and the water-cooled string-like resin was pelletized with a pelletizer. The obtained polyamide was a white tough polymer, and ηr = 2.88.

[Production Example 4: PA92 / 62T-4]
29.864 kg (147.64 mol) of dibutyl oxalate was charged, and 5.598 kg (35.36 mol) of 1,9-nonanediamine, 5.598 kg (35.36 mol) of 2-methyl-1,8-octanediamine and 1 , 6-hexanediamine 8.941 kg (76.92 mol) of a mixture (the molar ratio of 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,6-hexanediamine was 23.95: 23. 95: 52.10) was supplied to the reaction vessel by a diaphragm pump at a flow rate of 1.49 liters / minute over about 17 minutes, and at the same time the temperature was raised. The internal pressure in the pressure vessel immediately after the supply increased to 0.35 MPa by butanol generated by the polycondensation reaction, and the temperature of the polycondensate increased to about 170 ° C. Thereafter, the temperature was raised to 250 ° C. over 1 hour. Meanwhile, the internal pressure was adjusted to 1.00 MPa while extracting the generated butanol from the pressure relief port. Immediately after the temperature of the polycondensate reached 250 ° C., butanol was extracted from the pressure release port over about 20 minutes, and the internal pressure was brought to normal pressure. The temperature was raised from normal pressure while flowing nitrogen gas at 1.5 liters / minute, and the temperature of the polycondensate was increased to 270 ° C. over about 1 hour and reacted at 270 ° C. for 2 hours. Thereafter, stirring was stopped, the inside of the system was pressurized to 1 MPa with nitrogen and allowed to stand for about 10 minutes, then released to an internal pressure of 0.5 MPa, and the polycondensate was extracted in a string form from the lower outlet of the pressure vessel. The string-like polymer was immediately cooled with water, and the water-cooled string-like resin was pelletized with a pelletizer. The obtained polyamide was a white tough polymer with ηr = 2.83.

[Production Example 5: PA92 / 62T-5]
29.107 kg (143.89 mol) of dibutyl oxalate was charged, 5.641 kg (35.63 mol) of 1,9-nonanediamine, 10.028 kg (63.34 mol) of 2-methyl-1,8-octanediamine and 1 , 6-hexanediamine 5.223 kg (44.93 mol) (1,9-nonanediamine, 2-methyl-1,8-octanediamine, 1,6-hexanediamine molar ratio 24.76: 44. 02: 31.22) was supplied into the reaction vessel over about 17 minutes at a flow rate of 1.49 liters / minute by means of a diaphragm pump, and the temperature was raised. The internal pressure in the pressure vessel immediately after the supply increased to 0.35 MPa by butanol generated by the polycondensation reaction, and the temperature of the polycondensate increased to about 170 ° C. Thereafter, the temperature was raised to 250 ° C. over 1 hour. Meanwhile, the internal pressure was adjusted to 0.75 MPa while extracting the generated butanol from the pressure relief port. Immediately after the temperature of the polycondensate reached 240 ° C., butanol was extracted from the pressure release port over about 20 minutes, and the internal pressure was brought to normal pressure. The temperature was raised from normal pressure while flowing nitrogen gas at 1.5 liters / minute, and the temperature of the polycondensate was adjusted to 265 ° C. over about 1 hour, and the reaction was carried out at 265 ° C. for 3 hours. Thereafter, stirring was stopped, the inside of the system was pressurized to 1 MPa with nitrogen and allowed to stand for about 10 minutes, then released to an internal pressure of 0.5 MPa, and the polycondensate was extracted in a string form from the lower outlet of the pressure vessel. The string-like polymer was immediately cooled with water, and the water-cooled string-like resin was pelletized with a pelletizer. The obtained polyamide was a white tough polymer with ηr = 3.11.

[Reference Production Example 1: PA92C]
A mixture of 11.11 kg (70.2 mol) of 1,9-nonanediamine and 11.11 kg (70.2 mol) of 2-methyl-1,8-octanediamine was charged with 28.40 kg (140.4 mol) of dibutyl oxalate. Was supplied into the reaction vessel over about 17 minutes at a flow rate of 1.49 liters / minute by means of a diaphragm pump, and at the same time the temperature was raised. The internal pressure in the pressure vessel immediately after the supply increased to 0.35 MPa by butanol generated by the polycondensation reaction, and the temperature of the polycondensate increased to about 170 ° C. Thereafter, the temperature was raised to 235 ° C. over 1 hour. Meanwhile, the internal pressure was adjusted to 0.5 MPa while extracting the generated butanol from the pressure relief port. Immediately after the temperature of the polycondensate reached 235 ° C., butanol was extracted from the pressure release port over about 20 minutes, and the internal pressure was brought to normal pressure. From the normal pressure, the temperature was raised while flowing nitrogen gas at 1.5 liters / minute, the temperature of the polycondensate was brought to 260 ° C. over about 1 hour, and the reaction was carried out at 260 ° C. for 4.5 hours. . Thereafter, stirring was stopped, the inside of the system was pressurized to 1 MPa with nitrogen and allowed to stand for about 10 minutes, then released to an internal pressure of 0.5 MPa, and the polycondensate was extracted in a string form from the lower outlet of the pressure vessel. The string-like polymer was immediately cooled with water, and the water-cooled string-like resin was pelletized with a pelletizer. The obtained polyamide was a white tough polymer, and ηr = 3.35.

[Comparative Production Example 1: Production of PA92]
Using only 22.25 kg (140.4 mol) of 1,9-nonanediamine as a diamine raw material, a reaction was carried out in the same manner as in Production Example 1 to obtain a polyamide. The obtained polymer was a yellowish white polymer, and ηr = 2.78.

  Polyamide PA92 / 62T-1 to PA92 / 62T-5, PA92C, PA92, and nylon 6 (manufactured by Ube Industries, UBE nylon 1015B: PA6) produced in Production Examples 1-5, Reference Production Example 1 and Comparative Production Example 1. For nylon 66 (Ube Industries, UBE nylon 2020B: PA66) and nylon 12 (Ube Industries, UBESTA3020U: PA12), relative viscosity, melting point, crystallization temperature, 1% weight loss temperature, melt viscosity, saturated water absorption, resistance to water Chemical properties, hydrolysis resistance, mechanical properties in dry and wet conditions were measured. The results are shown in Table 1.

［実施例１〜７、比較例１，２］
エポキシ化スチレン系熱可塑性エラストマーとして、ダイセル化学製エポフレンドＡ１０１０を用い、表２に示す組成で、池貝鉄工（株）製２軸混練機ＰＣＭ−４５にて、シリンダー設定温度２９０℃（ＰＡ１２を用いた場合は２３０℃）、回転速度１５０ｒｐｍで溶融混練して金属被覆材を調製した。上記溶融混練した試料を金属基材（亜鉛メッキ鋼板及びアルミプレート）間に挟んだ複合体を作製し、接着力の評価を行った。また、上記溶融混練した試料から上記（５）の条件で成形したフィルムを用いて、それらの飽和吸水率および耐薬品性を、前述した方法により評価した。

[Examples 1 to 7, Comparative Examples 1 and 2]
As the epoxidized styrene-based thermoplastic elastomer, Daicel Chemical's Epofriend A1010 was used, and the composition shown in Table 2 was used. In this case, the metal coating material was prepared by melt-kneading at a rotation speed of 150 rpm. A composite was prepared by sandwiching the melt-kneaded sample between metal substrates (galvanized steel plate and aluminum plate), and the adhesive strength was evaluated. Moreover, the saturated water absorption rate and chemical resistance were evaluated by the above-described methods using a film molded from the melt-kneaded sample under the condition (5).

  The metal coating material of the present invention is capable of increasing the molecular weight by melt polymerization while having low water absorption, has a wide moldable temperature range estimated from the difference between the melting point and the thermal decomposition temperature, and has excellent melt moldability and chemical resistance. Because of its excellent hydrolysis resistance, for example, anti-corrosion coating for fluid metal pipes for general industrial use, anti-corrosion coating for metal pipes such as steel pipes and aluminum pipes for fuel, oil and brake fluids for automobiles, and coating of metal wires It can be suitably used as a metal coating material such as a coating of a water plate such as a water tank.

Claims (4)

The dicarboxylic acid component consists of oxalic acid,
The diamine component is from a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine (hereinafter referred to as “C9 diamine mixture”) and 1,6-hexanediamine (hereinafter referred to as “C6 diamine”). Become
The diamine component has a molar ratio of 1,9-nonanediamine to 2-methyl-1,8-octanediamine of 5:95 to 95: 5,
Including a polyamide resin in which the molar ratio of C9 diamine mixture to C6 diamine is from 1:99 to 99: 1;
A metal coating material further comprising an epoxidized styrenic thermoplastic elastomer .   The relative viscosity (ηr) of the polyamide resin when measured at 25 ° C. using a polyamide resin solution with a concentration of 1.0 g / dl using 96% sulfuric acid as a solvent is 1.8 to 6.0. The metal coating material according to 1.   1% weight loss temperature in thermogravimetric analysis of the polyamide resin measured at a heating rate of 10 ° C./min in a nitrogen atmosphere and by differential scanning calorimetry measured at a heating rate of 10 ° C./min in a nitrogen atmosphere. The metal coating | covering material of Claim 1 or 2 whose temperature difference with melting | fusing point measured is 50 degreeC or more. The metal coating | covering material in any one of Claims 1-3 which coat | covers the metal pipe for motor vehicles.