阅读说明：本技术 固化性树脂组合物、复合构件及其制造方法 (Curable resin composition, composite member, and method for producing same ) 是由 六田充辉 井口浩文 中村俊明 佐藤直 手塚睦朗 中岛康文 于 2019-08-07 设计创作，主要内容包括：本发明提供一种相对于金属等基材具有高密合性及耐久性的固化性树脂组合物、用该固化性树脂组合物对基材进行涂敷并进行树脂模塑而得到的复合成型构件、以及它们的制造方法。固化性树脂组合物含有聚酰胺类树脂、封端多异氰酸酯以及环氧化合物,上述聚酰胺类树脂具有20～300mmol/kg的氨基浓度,并且在ASTMD 570规定的吸水性试验中具有1质量％以下的吸水率。聚酰胺类树脂具有C-(8-18)亚烷基链,具有160～250℃的熔点。相对于聚酰胺类树脂的氨基1摩尔,封端多异氰酸酯的异氰酸酯基的比例为1.5～5摩尔,环氧化合物的环氧基的比例为0.1～0.8摩尔。(The invention provides a curable resin composition having high adhesion and durability to a base material such as a metal, a composite molded member obtained by coating and resin-molding a base material with the curable resin composition, and a method for producing the same. The curable resin composition contains a polyamide resin, a blocked polyisocyanate, and an epoxy compound, wherein the polyamide resin has an amino group concentration of 20 to 300mmol/kg and a water absorption of 1 mass% or less in a water absorption test specified in ASTM D570. The polyamide resin has C 8‑18 An alkylene chain having a melting point of 160 to 250 ℃. The ratio of the isocyanate group of the blocked polyisocyanate to 1 mole of the amino group of the polyamide resin is 1.5 to 5 moles, and the ratio of the epoxy group of the epoxy compound is 0.1 to 0.8 moles.)

1. A curable resin composition comprising:

a polyamide-based resin,

Blocked polyisocyanate, and

an epoxy compound, which is a compound of the formula,

wherein the polyamide resin contains an amino group and has a water absorption of 1 mass% or less in a water absorption test specified in ASTM D570.

2. The curable resin composition according to claim 1,

the polyamide resin contains C_8-18An alkylene chain having an amino group concentration of 20 to 300mmol/kg and a melting point of 160 to 250 ℃.

3. The curable resin composition according to claim 1 or 2,

the polyamide resin has C in the total amount of the components forming the polyamide resin_8-16The proportion of the alkylene chain component is 65 to 100 mol%, and the polyamide resin has a water absorption of 0.75 mass% or less in a water absorption test specified in ASTM D570.

4. The curable resin composition according to any one of claims 1 to 3,

the polyamide resin has C in the total amount of the components forming the polyamide resin_10-14The proportion of the alkylene chain component is 70 to 100 mol%, and the polyamide resin has an amino group concentration of 50 to 250mmol/kg and a melting point of 170 to 220 ℃.

5. The curable resin composition according to any one of claims 1 to 4,

the polyamide resin contains C in a proportion of 75 to 100 mol% based on the total amount of the components forming the polyamide resin_11-13Lactam and C_11-13At least one of the aminocarboxylic acids having C_11-13A polyamide resin obtained by homopolymerizing or copolymerizing a component having an alkylene chain, wherein the polyamide resin has a water absorption of 0.65 mass% or less in a water absorption test specified in astm d 570.

6. The curable resin composition according to any one of claims 1 to 5,

the polyamide resin has a water absorption of 0.3 mass% or less in a water absorption test specified in astm d 570.

7. The curable resin composition according to any one of claims 1 to 6,

the blocked polyisocyanate has a glass transition temperature of 60 to 110 ℃, a melting point of 70 to 130 ℃ and a dissociation temperature of 120 to 200 ℃,

the epoxy compound contains a bisphenol type epoxy resin having a softening temperature of 75 ℃ or higher.

8. The curable resin composition according to any one of claims 1 to 7,

the ratio of the isocyanate group of the blocked polyisocyanate to 1 mole of the amino group of the polyamide resin is 1.5 to 5 moles, and the ratio of the epoxy group of the epoxy compound is 0.1 to 0.8 moles.

9. The curable resin composition according to any one of claims 1 to 8,

the isocyanate group of the blocked polyisocyanate is in excess of 15 to 450mmol/kg relative to the amino group of the polyamide resin,

the concentration of the epoxy group is 3 to 35 mol% relative to the total number of moles of the amino group, the isocyanate group and the epoxy group.

10. The curable resin composition according to any one of claims 1 to 9,

the total number of moles of isocyanate groups in the blocked polyisocyanate is 1.3 to 50 times the total number of moles of amino groups in the polyamide resin,

the curable resin composition contains a blocked polyisocyanate in an amount of 5 to 30 parts by mass and an epoxy compound in an amount of 5 to 30 parts by mass based on 100 parts by mass of a polyamide resin.

11. A composite member having an adhesive layer of the curable resin composition according to any one of claims 1 to 10 formed on a surface of a base material.

12. A method of manufacturing a composite member, the method comprising:

a method for forming an adhesive layer, which comprises coating the surface of a substrate with the curable resin composition according to any one of claims 1 to 10.

13. A composite molded article comprising the adhesive layer of the composite member according to claim 11 and a composition comprising at least a thermoplastic resin molded or laminated thereon.

14. The composite molding member according to claim 13,

the base material is a metal base material,

the thermoplastic resin includes a polyamide-based resin having a higher melting point than the polyamide-based resin of the curable resin composition.

15. A method of manufacturing a composite profiled element, the method comprising:

a composite molded article is produced by molding or laminating a composition containing at least a thermoplastic resin on the adhesive layer of the composite member according to claim 11.

Technical Field

The present invention relates to a curable resin composition useful for imparting high adhesion and durability to a substrate such as a metal, a composite member in which the surface of the substrate is coated with a cured film of the curable resin composition, a composite molded member in which a resin layer is molded on the cured film, and methods for producing the same.

Background

In order to improve corrosion resistance, durability, and the like of metals, formation of a coating layer by a fluidized immersion method, electrostatic coating, or the like has been carried out. In particular, in applications requiring high durability, such as structural members of vehicles (automobiles and the like) and airplanes and the like, a metal is subjected to a primer treatment, and a resin is molded into a primer layer (adhesive layer) to achieve mixing, thereby producing a mixed member.

Jp 2007-190917 a (patent document 1) and corresponding U.S. publication No. US2011/0143142a1 describe a method for producing a mixed member made of a metal and a polymer, in which the metal and the polymer are bonded by a melt adhesive containing a copolyamide as a base and an isocyanate and an epoxide as additional components, and the melt adhesive contains a copolyamide based on laurolactam, 2.5 to 15% of a blocked isocyanate, and 2.5 to 10% of an epoxide. This document describes a melt adhesive comprising VESTAMELT X1038-P1 (containing 60% laurolactam, 25% caprolactam and 15% AH salt (containing a mixture of 50% adipic acid and 50% hexamethylenediamine)) (95%), VESTAGON BF1540-P1 (5%) and Araldite GT7004 (5%) from Degussa, and further describes that a polymer structure is formed by injection molding in the final step.

When the adhesive is electrostatically coated and heated, an adhesive layer having high adhesion to a metal can be formed, and a thermoplastic resin is injection-molded on the adhesive layer, whereby a highly durable hybrid member can be produced.

However, although the reason is not clear, if the mixing member formed in this way is immersed in hot water, adhesion may be reduced. Further, if a thermoplastic resin is injection-molded on the adhesive layer, voids may be formed at the interface between the metal and the adhesive layer. Therefore, high corrosion resistance and durability cannot be maintained for a long period of time.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2007 & 190917 (claims, [0009], [0010])

Disclosure of Invention

Problems to be solved by the invention

Accordingly, an object of the present invention is to provide a curable resin composition useful for imparting high adhesion and durability to a substrate such as a metal, a composite member in which the surface of the substrate is coated with a coating layer (an adhesive layer or a cured film) of the curable resin composition, a composite molded member in which resin molding is performed on the adhesive layer, and methods for producing the same.

Another object of the present invention is to provide a curable resin composition useful for forming an adhesive layer (or cured film) having high adhesion to a base material such as a metal and improved hot water resistance, a composite member (composite member primed with the curable resin composition) using the resin composition, a composite molded member, and methods for producing the same.

Another object of the present invention is to provide a curable resin composition suitable for molding a thermoplastic resin to an adhesive layer (or cured film) at high temperature to obtain a composite molded member having high durability and uniformity.

Means for solving the problems

The present inventors have studied the cause of the decrease in adhesion caused by immersing the above-mentioned hybrid member in hot water, and as a result, have found that: when a thermoplastic resin is molded on an adhesive layer, voids are easily generated at the interface between a base material such as a metal and the molten adhesive layer depending on molding conditions; the terminal amino group of the polyamide-based resin of the molten adhesive has a large correlation with the adhesion. The present inventors have further studied based on these findings and as a result, have found that when an adhesive layer is formed on the surface of a base material using a curable resin composition containing a predetermined polyamide-based resin having a terminal amino group, a blocked polyisocyanate and an epoxy compound, the adhesion to the base material is extremely high even when a thermoplastic resin is molded (formed) on the adhesive layer, and a uniform and highly durable molded member can be reliably obtained even when immersed in hot water, thereby completing the present invention.

That is, the curable resin composition (or reactive resin composition) of the present invention contains a polyamide-based resin, a blocked polyisocyanate, and an epoxy compound, and the polyamide-based resin contains an amino group (for example, a terminal amino group) and has low water absorption. That is, the water absorption of the polyamide resin is 1 mass% or less (for example, 0.75 mass% or less, preferably 0.65 mass% or less, and more preferably 0.3 mass% or less) in the water absorption test defined in ASTM D570.

The polyamide resin contains C_8-18Alkylene chain (e.g. C)_9-16Alkylene chain), the amino group concentration of the polyamide-based resin may be about 5 to 300mmol/kg (for example, about 20 to 300mmol/kg, preferably about 50 to 250mmol/kg, and more preferably about 100 to 200 mmol/kg). The melting point of the polyamide resin may be about 160 to 250 ℃ (for example, about 160 to 230 ℃, preferably about 170 to 220 ℃).

The polyamide resin may contain C in a proportion of 65 to 100 mol% (for example, 70 to 100 mol%) relative to the total amount of the components (monomers) forming the polyamide resin_8-16Component of an alkylene chain (e.g. having C)_10-14A component of the alkylene chain). Specifically, the polyamide-based resin may contain C in a proportion of 75 to 100 mol% (for example, 80 to 100 mol%) based on the total amount of the components (monomers) forming the polyamide-based resin_11-13Lactam and C_11-13At least one of the aminocarboxylic acids having C_11-13A homopolymeric or copolymeric polyamide resin of a component of the alkylene chain.

The blocked polyisocyanate may have a glass transition temperature of 60 to 110 ℃, a melting point of 70 to 130 ℃ and a dissociation temperature of 120 to 200 ℃. The epoxy compound may contain a bisphenol epoxy resin having a softening temperature of 75 ℃ or higher.

The amount ratio of each component may be selected depending on the concentration, reactivity, and the like of the functional group (reactive group) of each component, and the amount of the isocyanate group (blocked isocyanate group) of the blocked polyisocyanate may be excessive, for example, 1.5 to 5 moles (for example, 2 to 4 moles) relative to 1 mole of the amino group of the polyamide-based resin.

The proportion of the epoxy group in the epoxy compound may be, for example, about 0.1 to 0.8 mol (for example, about 0.2 to 0.7 mol) relative to 1 mol of the amino group concentration of the polyamide resin.

In the resin composition, the concentration (mmol/kg) of the isocyanate group (NCO) of the blocked polyisocyanate with respect to the amino group (NH) of the polyamide-based resin₂) The concentration (mmol/kg) of (A) may be excessive, for example, 15 to 450mmol/kg (for example, 30 to 300mmol/kg) may be excessive. The total number of moles of isocyanate groups of the blocked polyisocyanate may be 1.3 to 50 times (for example, 1.5 to 40 times) the total number of moles of amino groups of the polyamide-based resin. In addition, the concentration of the epoxy group in the resin composition may be, for example, about 3 to 35 mol% (e.g., about 5 to 25 mol%) relative to the total amount (total number of moles) of the amino group, the isocyanate group, and the epoxy group.

The ratio (molar ratio) of the isocyanate group of the blocked polyisocyanate to the hydroxyl group (secondary hydroxyl group) of the epoxy compound may be, for example, about 0.6/1 to about 1.4/1.

The amount of the polyamide-based resin may be about 65 to 90% by mass, the amount of the blocked polyisocyanate may be about 5 to 30 parts by mass, and the amount of the epoxy compound may be about 5 to 30 parts by mass, based on 100 parts by mass of the total amount of the polyamide-based resin, the blocked polyisocyanate, and the epoxy compound.

The present invention also includes a composite member (composite) including an adhesive layer formed of a curable resin composition (such as a powdery composition) and a method for producing the composite member. In this composite member, an adhesive layer (e.g., a reactive adhesive layer) formed of the curable resin composition is formed on the surface of a base material (e.g., a metal base material). The composite member can be produced by coating (for example, powder coating such as electrostatic powder coating or fluidized dip coating) the surface of the substrate with the curable resin composition (for example, a powdery curable resin composition) to form an adhesive layer.

The present invention also includes a composite molded member (insert molded member or laminate) obtained by molding or laminating a composition containing at least a thermoplastic resin on the adhesive layer, and a method for producing the same. The thermoplastic resin may include a polyamide-based resin having a higher melting point than the polyamide-based resin of the curable resin composition.

The composite molded member can be produced by forming the adhesive layer and then molding (for example, injection molding) or laminating (or laminating) a composition containing at least a thermoplastic resin on the adhesive layer.

In the present specification, the epoxy resin is also included, and may be simply referred to as "epoxy compound", and the blocked isocyanate group of the blocked polyisocyanate may be simply referred to as "isocyanate group". In addition, glycidyl groups are also included and may be simply referred to as "epoxy groups".

ADVANTAGEOUS EFFECTS OF INVENTION

In the present invention, since a predetermined curable resin composition (adhesive resin composition) is used, a composite member coated with an adhesive layer (or cured film) having high adhesion to a base material such as a metal and high durability can be produced, and a composite molded member can be produced by molding or laminating a thermoplastic resin on the adhesive layer. In addition, a composite member having an adhesive layer (or a reactive adhesive layer) formed by undercoating with a curable resin composition has high adhesion to a base material such as a metal, and can be greatly improved in hot water resistance. Therefore, even when the adhesive layer (or cured film) is molded or laminated with a thermoplastic resin at a high temperature, a composite molded member having high durability can be obtained uniformly without generating voids at the interface between the adhesive layer and the base material such as metal.

Detailed Description

The polyamide-based resin includes a polyamide resin (including a homo-or co-polyamide resin) and a polyamide elastomer (polyamide block copolymer), and may be formed from any of the amide-forming components (a) to (c) described below.

(a) A first amide-forming component comprising an alkylenediamine component and an alkanedicarboxylic acid component in combination;

(b) a second amide-forming component containing at least one of a lactam component and an aminocarboxylic acid component;

(c) a first amide forming component and a second amide forming component.

That is, the polyamide-based resin may be formed from any of the amide-forming components (a) to (c) (the first amide-forming component; the second amide-forming component; the combination of the first amide-forming component and the second amide-forming component), and the polyamide elastomer may be produced using a polyamide formed from any of the amide-forming components (a) to (c). The lactam component and the aminocarboxylic acid component having a common carbon number and a common branched structure can be regarded as equivalent components.

The polyamide resin may be an alicyclic polyamide, but is usually an aliphatic polyamide in many cases. The polyamide resin may be a homopolyamide resin or a copolyamide resin (copolyamide resin). The copolymerized polyamide resin may be, for example: a copolymerized polyamide resin comprising first amide-forming components having different carbon atoms; a copolymerized polyamide resin of a first amide-forming component and a second amide-forming component; and a copolymerized polyamide resin comprising a second amide-forming component having a different carbon number. The copolymerized polyamide resin composed of the first amide-forming component and/or the second amide-forming component having different carbon atoms may be referred to as a first copolymerized polyamide resin, and the copolymerized polyamide resin composed of the first amide-forming component and/or the second amide-forming component and a copolymerized component (alicyclic or aromatic component) may be referred to as a second copolymerized polyamide resin.

Examples of the above-mentioned alkylenediamine component include: c such as octamethylenediamine, decamethylenediamine, dodecanediamine, tetradecanediamine, octadecanediamine_8-18Alkylene diamines, and the like. These diamine components may be used alone, or two or more thereof may be used in combination. Preferred diamine component contains at least C_8-18Alkylene diamine (preferably C)_10-16Alkylene diamine, preferably C_11-16Alkylene diamine, particularly preferably dodecane diamine and the like C_11-14Alkylene diamine).

Examples of the alkane dicarboxylic acid component include: suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, octadecanedioic acid, and the like C_8-36Alkane dicarboxylic acids, and the like. These dicarboxylic acid components may be used alone or two or more of them may be used in combination. Preferred dicarboxylic acid component comprises C_8-18Alkanedicarboxylic acids (e.g. as C)_10-16Alkanedicarboxylic acids, preferably C_12-14Alkane dicarboxylic acids, etc.).

In the first amide forming component, the diamine component may be used in an amount of 0.8 to 1.2 mol, preferably about 0.9 to 1.1 mol, based on 1 mol of the dicarboxylic acid component.

As the lactam component, for example: c such as omega-octalactam, omega-nonalactam, omega-decanolactam, omega-undecenolactam, omega-laurolactam (or omega-lauryllactam or laurolactam), omega-tridecanolactam_8-20Lactams, and the like. As the aminocarboxylic acid component, for example: c such as omega-aminodecanoic acid, omega-aminoundecanoic acid, omega-aminododecanoic acid, omega-aminotridecanoic acid_8-20Aminocarboxylic acids, and the like. These lactam components and aminocarboxylic acid components may be used alone or in combination of two or more.

A preferred lactam component is, for example, C_8-18Lactams, preferably C_10-16Lactams (e.g. C)_10-15Lactam), more preferably C_10-14Lactams (e.g. C)_11-13Lactams); the preferred aminocarboxylic acids also have the same number of carbon atoms as the preferred lactam component described above. In particular, the lactam component and/or the aminocarboxylic acid will in most cases comprise at least C_11-12A lactam component and/or an aminocarboxylic acid (e.g., undecanolactam, laurolactam (or lauryllactam), aminoundecanoic acid, aminododecanoic acid, etc.), for example, a lactam component having 12 carbon atoms and/or an aminocarboxylic acid.

The ratio (molar ratio) of the first amide-forming component to the second amide-forming component may be selected from the range of 100/0 to 0/100, and may be, for example, about 90/10 to 0/100 (e.g., 80/20 to 5/95), preferably about 75/25 to 10/90 (e.g., 70/30 to 15/85), and more preferably about 60/40 to 20/80.

Preferred polyamide resins contain at least C_8-18The alkylene chain (or linear alkylene chain), e.g. C_8-16Alkylene chain (e.g. C)_9-15Alkylene chain), preferably C_10-14Alkylene chain (e.g. C)_11-14Alkylene chain), further preferably having C_11-13Alkylene chain (e.g. C)_11-12Alkylene chain) as the first and/or second amide forming component.

The polyamide resin formed from such components has high hot water resistance and heat resistance, and has excellent adhesion to a base material such as a metal, and is useful for forming a uniform and strong adhesive layer (primer layer or reactive adhesive layer) on the surface of the base material.

The above-mentioned compound having C is used_8-18Component of alkylene chain the polyamide resin of the first and/or second amide-forming component may be a homopolyamide resin (a homopolyamide resin of a component having an alkylene chain with a specific carbon number), or a first homopolyamide resin (C described above)_8-18A copolymer of a plurality of components having different numbers of carbon atoms in an alkylene chain; above-mentioned has C_8-18A first copolymerized polyamide resin comprising a component of an alkylene chain (or a linear alkylene chain) and a short-chain first and/or second amide-forming component).

The short-chain first amide-forming component includes, for example: carbon number C of main chain of tetramethylenediamine, hexamethylenediamine, trimethylhexamethylenediamine, etc_4-7An alkylene diamine; adipic acid, pimelic acid, etc. C_6-7Alkane dicarboxylic acids, etc., and examples of the short-chain secondary amide-forming component include C such as. delta. -valerolactam,. epsilon. -caprolactam, and. omega. -heptanolactam_4-7Lactam, C_4-7Aminocarboxylic acids, and the like. The amount of the short-chain first and second amide forming components used may be small, for example, 0 to 50 mol%, preferably 0 to 40 mol%, and more preferably about 0 to 30 mol% based on the whole amount of the first and second amide forming components.

Further, the copolymerized polyamide resin may be a copolymer of the first and/or second amide-forming component and a copolymerizable copolymerization component (second copolymerized polyamide resin) if necessary, and the diamine component as the copolymerization component may be an alicyclic diamine component (diamino C such as diaminocyclohexane)_5-10Cycloalkanes; bis (amino C) such as bis (4-aminocyclohexyl) methane, bis (4-amino-3-methylcyclohexyl) methane, and 2, 2-bis (4-aminocyclohexyl) propane_5-8Cycloalkyl) C_1-3Alkanes and the like; hydrogenated xylylenediamine, etc.), an aromatic diamine component (m-xylylenediamine, etc.), etc. The dicarboxylic acid component as the copolymerization component may be an alicyclic dicarboxylic acid component (C such as cyclohexane-1, 4-dicarboxylic acid or cyclohexane-1, 3-dicarboxylic acid)_5-10Cycloalkane-dicarboxylic acids, etc.), aromatic dicarboxylic acids (terephthalic acid, isophthalic acid, etc.), etc. The alicyclic polyamide resin (transparent polyamide) can be formed using an alicyclic diamine component and/or an alicyclic dicarboxylic acid component as a copolymerization component with the first and/or second amide-forming component.

The proportion of the first and second amide forming components in the polyamide resin may be about 60 to 100 mol% (e.g., 70 to 100 mol%), preferably about 80 to 100 mol% (e.g., 85 to 97 mol%), and more preferably about 90 to 100 mol% with respect to the entire components. In particular, preferred polyamide resins comprise a polyamide having C_8-16Alkylene chain (preferably C)_10-14Alkylene chain, more preferably C_11-13The proportion of the alkylene chain) component is about 65 to 100 mol% (e.g., 65 to 98 mol%), preferably 70 to 100 mol% (e.g., 75 to 98 mol%), more preferably 80 to 100 mol% (e.g., 85 to 100 mol%), and particularly preferably 90 to 100 mol% (e.g., 95 to 100 mol%) relative to the total amount of the polyamide resin-forming component (monomer) (or first and second amide-forming components). Particularly preferred polyamide resins comprise a monomer selected from, for example, C_11-13Lactam and/or C_11-13At least one of aminocarboxylic acids (e.g., laurolactam, aminoundecanoic acid, and aminododecanoic acid) as the amide-forming componentA poly or copolymerized polyamide resin.

The polyamide resin may be a modified polyamide such as a polyamide in which a branched structure is introduced with a small amount of a polycarboxylic acid component and/or a polyamine component.

As such a polyamide resin, for example: homopolyamide resins (polyamide 8, polyamide 9, polyamide 10, polyamide 11, polyamide 12, polyamide 13, polyamide 610, polyamide 611, polyamide 612, polyamide 911, polyamide 912, polyamide 1010, polyamide 1012, and the like), copolyamides (polyamide 6/10, polyamide 6/11, polyamide 6/12, polyamide 10/10, polyamide 10/12, polyamide 11/12, polyamide 12/13, polyamide 12/18, polyamide 14/18, and the like), and the like. These polyamide resins may be used alone, or two or more kinds may be used in combination. In the polyamide resin, a component divided by a slash "/" indicates a first or second amide forming component. In particular, polyamide resins having a relatively long alkylene chain are often used, for example, polyamide 610, polyamide 612, polyamide 1010, polyamide 1012, polyamide 10, polyamide 11, polyamide 12, polyamide 6/10, polyamide 6/11, polyamide 6/12, and the like, and particularly, polyamide 11 and polyamide 12 (for example, a homopolymer of laurolactam) and the like.

The polyamide elastomer (polyamide block copolymer) includes a polyamide block copolymer composed of a polyamide segment (corresponding to the polyamide resin, for example, polyamide 11, polyamide 12, etc.) as a hard segment (or hard block) and a soft segment (or soft block), and the soft segment may be composed of, for example, polyether, polyester, polycarbonate, etc. Representative polyamide elastomers are polyamide-polyether block copolymers, such as: polyetheramides [ e.g. dicarboxylic-terminated polyamide blocks with diol-terminated poly-C_2-6Block copolymers of alkylene glycol block (or polyoxyalkylene block), and the like]And the like. The polyamide elastomer may have an ester bond.

In the polyamide elastomer, the number average molecular weight (in terms of polystyrene) of the soft segment may be selected from, for example, about 100 to 10000, and may be about 300 to 5000 (e.g., about 500 to 5000), and preferably about 1000 to 2000, as measured by Gel Permeation Chromatography (GPC). The ratio (mass ratio) of the polyamide block (polyamide segment) to the soft segment (or block) may be, for example, about 75/25 to 10/90, preferably about 70/30 to 15/85.

These polyamide-based resins may be used alone or in combination of two or more. Among these polyamide-based resins, the above polyamide resin is preferable.

The polyamide-based resin preferably has low water absorption or moisture absorption. That is, the water absorption rate of the polyamide-based resin may be 1% by mass or less (e.g., 0.01 to 0.8% by mass), preferably 0.75% by mass or less (e.g., 0.05 to 0.65% by mass), more preferably 0.65% by mass or less (e.g., 0.1 to 0.55% by mass), particularly about 0.5% by mass or less (e.g., 0.1 to 0.4% by mass), or 0.1 to 0.65% by mass, preferably 0.12 to 0.55% by mass, more preferably 0.15 to 0.45% by mass, particularly 0.3% by mass or less (e.g., 0.15 to 0.25% by mass). The water absorption can be measured as follows: the dried sample was cooled in a desiccator based on the water absorption test specified in ASTM D570, the mass of the sample was measured, the sample was immersed in water at 23 ℃ for 24 hours and then taken out, pressed with a cloth, excess water was wiped off, the mass was measured, and the change in mass (increase rate) of the test piece was calculated. It should be noted that a sample having a thickness of 0.125 inch (about 0.32cm) can be used.

The equilibrium water content may be, for example, 2 mass% or less (e.g., 0.1 to 1.8 mass%), preferably 1.5 mass% or less (e.g., 0.3 to 1.5 mass%), more preferably 1.3 mass% or less (e.g., 0.4 to 1.3 mass%), particularly preferably 1 mass% or less (e.g., 0.5 to 0.9 mass%), or may be about 0.5 to 0.85 mass% (e.g., 0.6 to 0.8 mass%) at a relative humidity of 50% RH and at room temperature of 23 ℃.

The saturated water content may be 5 mass% or less (e.g., 0.5 to 4.5 mass%), preferably 0.5 to 4 mass% (e.g., 0.6 to 3.8 mass%), more preferably 0.8 to 3.5 mass% (e.g., 1 to 3 mass%), and particularly preferably about 1.1 to 2.8 mass% (e.g., 1.2 to 2.7 mass%) when measured after being immersed in water at 23 ℃ for 1 week according to the method a of ISO 62.

The polyamide-based resin preferably has a small average concentration of amide bonds per repeating unit, and the average concentration of amide bonds may be, for example, about 1 to 10 mol/kg (e.g., about 2 to 9 mol/kg), preferably about 3 to 8 mol/kg (e.g., about 4 to 7 mol/kg), and more preferably about 5 to 7 mol/kg.

The polyamide-based resin may be amorphous, but generally has crystallinity. The polyamide resin may have a crystallinity of, for example, 1 to 50% (e.g., 1 to 30%), preferably 5 to 25%, and more preferably 10 to 20%. The crystallinity can be measured by a conventional method, for example, a measurement method based on density and heat of fusion, an X-ray diffraction method, an infrared absorption method, or the like.

The polyamide resin has an amino group (particularly, a terminal amino group) in order to improve the adhesion of the adhesive layer to a base material such as a metal. Amino group concentration C of the Polyamide resin_NH2The amount (unit: mmol/kg) is selected from the range of about 5 to 300 (e.g., about 25 to 275), for example, about 50 to 250 (e.g., about 75 to 225), preferably about 100 to 200 (e.g., about 120 to 180), usually about 50 to 200 (e.g., about 50 to 180), preferably about 75 to 190 (e.g., about 80 to 175), more preferably about 100 to 170 (e.g., about 100 to 150), and particularly preferably about 125 to 160. When the amino group concentration of the polyamide-based resin is high, the adhesiveness of the adhesive layer formed of the curable resin composition can be greatly improved.

The concentration (unit: mmol/kg) of the carboxyl group (terminal carboxyl group) of the polyamide-based resin is not particularly limited, and may be, for example, 50 or less (for example, 0 to 25), usually 20 or less (for example, 1 to 15), preferably 10 or less (for example, 1.5 to 7), and more preferably 2 to 5 or so.

In the polyamide-based resin, the ratio of the amino group to the carboxyl group is not particularly limited, and the concentration of the amino group is preferably higher than that of the carboxyl group. The ratio (molar ratio) of the amino group to the carboxyl group in the polyamide resin may be, for example, about 60/40 to 100/0 (e.g., 70/30 to 99.9/0.1), preferably about 80/20 to 100/0 (e.g., 85/15 to 99.5/0.5), and more preferably about 90/10 to 99/1 (e.g., 95/5 to 98/2).

The amino group concentration and the carboxyl group concentration can be measured by a conventional method, for example, a titration method. For example, the amino group concentration can be measured by dissolving a polyamide resin (sample) in a mixed solvent of phenol and ethanol at a volume ratio of 10:1 to prepare a1 mass% solution, and performing neutralization titration with 1/100 equivalents of an aqueous HCl solution. The carboxyl group concentration can be measured by dissolving a polyamide resin (sample) in benzyl alcohol to prepare a1 mass% benzyl alcohol solution, and performing neutralization titration with 1/100 equivalents of an aqueous KOH solution.

The polyamide resin is solid at room temperature, and the melting point of the polyamide resin may be, for example, about 150 to 260 ℃ (e.g., 160 to 250 ℃), preferably about 165 to 230 ℃ (e.g., 170 to 220 ℃), or about 175 to 210 ℃ (e.g., 175 to 200 ℃) and preferably about 175 to 190 ℃ (e.g., 175 to 185 ℃). The melting point of the crystalline polyamide-based resin can be measured by a Differential Scanning Calorimeter (DSC). The melting point of the polyamide-based resin is a temperature corresponding to a peak on the high temperature side among a plurality of peaks when the plurality of peaks are generated in the DSC.

Number average molecular weight of the polyamide resin (unit:. times.10)⁴) For example, the concentration of the metal oxide is selected from the range of about 0.5 to 20 (e.g., about 0.7 to 15), and may be about 0.8 to 10 (e.g., about 0.9 to 8), and preferably about 1 to 7 (e.g., about 1 to 5). The molecular weight of the polyamide-based resin can be measured by gel permeation chromatography using HFIP (hexafluoroisopropanol) as a solvent in terms of polymethyl methacrylate.

The melt flow rate (MFR, unit: g/10 min) of the polyamide resin may be about 1 to 100 (e.g., 2 to 80), preferably about 5 to 75 (e.g., 7 to 60), and more preferably about 10 to 50 (e.g., 12 to 35) at a temperature of 230 ℃ and a load of 2.16 kg. MFR can be determined using a melt flow rate meter, according to ISO 1133.

The second polyamide resin (for example, a homo-or co-polyamide resin using a component having an alkylene chain with a small carbon number, particularly a homo-or co-polyamide resin having a water absorption rate of more than 1% by mass and/or a co-polyamide resin having a melting point of less than 150 ℃ or the like) may be added to the polyamide resin (first polyamide resin) having a water absorption rate of 1% by mass or less, within a range in which properties such as adhesiveness are not impaired. The first polyamide resin having a water absorption of 1% by mass or less may be used in a proportion of 65% by mass or more, preferably 70% by mass or more, and more preferably 75% by mass or more of the entire polyamide resin, depending on the water absorption of the first and/or second polyamide resin, and the like.

The polyamide-based resin may contain various additives, such as stabilizers (heat-resistant stabilizers, weather-resistant stabilizers, antioxidants, ultraviolet absorbers, etc.), colorants, fillers, plasticizers, lubricants, flame retardants, antistatic agents, silane coupling agents, etc., as required. The additives may be used alone, or two or more of them may be used in combination. The polyamide-based resin and the resin composition thereof are usually in a powdery form in many cases.

[ blocked polyisocyanate ]

The polyisocyanate of the blocked polyisocyanate may be any of aromatic polyisocyanate, alicyclic polyisocyanate, aliphatic polyisocyanate, and heterocyclic polyisocyanate. As the aromatic polyisocyanate, for example: diisocyanates such as Toluene Diisocyanate (TDI), Xylylene Diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), Naphthalene Diisocyanate (NDI), bis (isocyanatophenyl) Methane (MDI), 1, 3-bis (isocyanatophenyl) propane, bis (isocyanatophenyl) ether, bis (isocyanatophenyl) sulfone, and dimethylbiphenyl diisocyanate (TODI). As the alicyclic polyisocyanate, for example: diisocyanates such as cyclohexane 1, 4-diisocyanate, isophorone diisocyanate (IPDI), hydrogenated xylylene diisocyanate, and hydrogenated bis (isocyanatophenyl) methane; triisocyanates such as bicycloheptane triisocyanate, and the like. The aliphatic polyisocyanate may be exemplified byExamples are as follows: c such as propylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, Hexamethylene Diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMDI) or Lysine Diisocyanate (LDI)_2-12An alkane diisocyanate; alkane triisocyanates such as 1,3, 6-hexamethylene triisocyanate and 1,6, 11-undecane triisocyanate methyloctane.

These polyisocyanates may also be derivatives thereof, such as dimers, trimers (polyisocyanates having isocyanurate rings), tetramers, and like multimers; an adduct; modified biuret, allophanate, urea, and the like; urethane oligomers, and the like. Specifically, the derivatives of the polyisocyanate can be exemplified by, for example: an adduct of a polyisocyanate (an alkane polyisocyanate such as hexamethylene diisocyanate) and a polyol (trimethylolpropane, pentaerythritol, etc.), a biuret product of the above polyisocyanate, an isocyanurate product having the above isocyanurate ring (isocyanurate skeleton) (for example, a polyisocyanate having an isocyanurate ring which is a trimer of hexamethylene diisocyanate, etc.), a polyisocyanate having an uretdione skeleton, etc.

Among these polyisocyanates, aliphatic polyisocyanates, aromatic polyisocyanates (TDI, MDI, etc.), derivatives thereof (e.g., HDI, a trimer thereof, etc.), and the like are often used.

Examples of the blocking agent (protecting agent) for blocking the polyisocyanate include: alcohols such as isopropyl alcohol and 2-ethylhexanol; phenols such as phenol, cresol, xylenol and resorcinol; oximes such as acetoxime, methylethylketoxime, and cyclohexanoxime; lactams such as epsilon-caprolactam; and active methylene compounds such as ethyl acetoacetate. These end-capping agents may be used alone or in combination of two or more. These blocking agents may be selected depending on the type of polyisocyanate, dissociation temperature, and the like, and phenols, oximes, epsilon-caprolactam, active methylene compounds, and the like are often used.

The content of the isocyanate group (blocked isocyanate group) in the blocked polyisocyanate may be, for example, about 5 to 30% by mass (e.g., about 7.5 to 25% by mass), preferably about 10 to 20% by mass (e.g., about 12.5 to 17.5% by mass), or about 13 to 20% by mass (e.g., about 14 to 18% by mass, preferably about 15 to 17% by mass),

the blocked polyisocyanate may have an isocyanate equivalent weight (unit: g/eq.) of, for example, 150 to 350, preferably 175 to 300, and more preferably 200 to 280 (for example, 230 to 275) or so.

Concentration C of isocyanate groups (blocked isocyanate groups) in the blocked polyisocyanate_NCOThe amount of (mmol/kg) may be, for example, about 500 to 5500 (e.g., 750 to 5250), preferably about 1000 to 5000 (e.g., 1500 to 4500), and more preferably about 2000 to 4500 (e.g., 2500 to 4000), and may be about 3000 to 4000.

The blocked polyisocyanate is usually solid at room temperature, and the glass transition temperature (glass transition temperature) of the blocked polyisocyanate may be, for example, 50 to 120 ℃, preferably 60 to 110 ℃ (for example, 65 to 95 ℃), more preferably 70 to 100 ℃ (for example, 75 to 85 ℃), and usually 65 to 100 ℃ (for example, 70 to 90 ℃).

The melting point of the blocked polyisocyanate may be, for example, about 70 to 130 ℃, preferably about 80 to 120 ℃, and more preferably about 90 to 115 ℃, or about 80 to 125 ℃ (e.g., about 95 to 115 ℃).

The dissociation temperature of the blocked polyisocyanate (temperature at which the blocking agent is removed to regenerate the isocyanate group) may be, for example, about 100 to 220 ℃ (e.g., 120 to 200 ℃), preferably about 130 to 190 ℃ (e.g., 140 to 180 ℃), and more preferably about 150 to 170 ℃ (e.g., 155 to 165 ℃). When the dissociation temperature is too low, the storage stability of the curable resin composition tends to be lowered, and when it is too high, the coating film formation temperature or firing temperature may be increased, which may result in a reduction in workability and a reduction in adhesiveness of the adhesive layer.

In order to adjust the dissociation temperature, a dissociation catalyst may be added, for example: tin compounds such as dibutyltin laurate, tertiary amines such as N-methylmorpholine, and organic acid metal salts such as alkali metal acetates and alkaline earth metal acetates.

The blocked polyisocyanate is usually in the form of powder.

[ epoxy Compound ]

Examples of the epoxy compound (or epoxy resin) include: glycidyl ether compounds, glycidyl ester compounds, glycidyl amine compounds, heterocyclic epoxy compounds, alicyclic epoxy compounds, and the like, and have a plurality of glycidyl groups or epoxy rings. Examples of the glycidyl ether compound (glycidyl ether type epoxy resin) include: bisphenol type epoxy resins (bisphenol-based epoxy resins such as bisphenol a type, bisphenol F type, bisphenol AD type, bisphenol S type, bisphenol fluorene type, and the like), naphthol type epoxy resins, biphenyl type epoxy resins, triphenol methane type epoxy resins, novolac type epoxy resins (phenol novolac type epoxy resins, cresol novolac type epoxy resins, and the like), modified novolac type epoxy resins, and the like.

As the glycidyl ester compound (glycidyl ester type epoxy resin), for example: and glycidyl esters of polycarboxylic acids such as diglycidyl phthalate, tetrahydrophthalic acid, and hexahydrophthalic acid.

As the glycidylamine compound (glycidylamine-type epoxy resin), there can be exemplified: tetraglycidylaminodiphenylmethane, triglycidylaminophenol, and the like.

As the heterocyclic epoxy compound (heterocyclic epoxy resin), for example: triglycidyl isocyanurate (triazine type epoxy resin), hydantoin type epoxy resin, and the like. As the alicyclic epoxy compound (alicyclic epoxy resin), an epoxy resin obtained by epoxidizing a cyclohexene ring can be exemplified.

These epoxy compounds may be used alone, or two or more kinds may be used in combination. The epoxy compound is preferably an epoxy resin having a high softening point or melting point, and examples thereof include glycidyl ether type epoxy resins, glycidyl amine type epoxy resins, and alicyclic epoxy resins, and particularly, bisphenol-based glycidyl ether type epoxy resins (bisphenol type epoxy resins) such as bisphenol a. Further, the epoxy compound may be a monomer, but preferably contains a multimer (for example, a multimer of 3-or more mers) such as a 2-mer, a 3-mer, a 4-mer, a 5-mer, or a 10-mer. Such multimers often have hydroxyl groups associated with multimerization. The proportion of the polymer may be 45 to 99.9%, preferably 50 to 99%, and more preferably 55 to 98% or so in terms of area ratio in gel permeation chromatography.

The epoxy equivalent (unit: g/eq.) of the epoxy compound may be selected from the range of about 250 to 5000, and for example, may be about 300 to 3000 (e.g., 400 to 2500), preferably about 500 to 2000 (e.g., 600 to 1700), more preferably about 650 to 1000 (e.g., 700 to 800), may be about 450 to 1500 (e.g., 500 to 1200), preferably about 550 to 1000 (e.g., 600 to 900), and more preferably about 650 to 800 (e.g., 700 to 770).

Concentration C of epoxy groups of epoxy compound_EPThe amount of (mmol/kg) may be, for example, about 100 to 1000 (e.g., 150 to 900), preferably about 200 to 800 (e.g., 250 to 750), more preferably about 300 to 700 (e.g., 350 to 650), and may be about 400 to 600 (e.g., 450 to 570).

The hydroxyl group concentration (mmol/kg) of the epoxy compound (or epoxy resin) may be, for example, about 500 to 5500 (e.g., 750 to 5250), preferably about 1000 to 5000(1500 to 4500), more preferably about 2000 to 4500 (e.g., 2500 to 4000), or about 3000 to 4000 (e.g., 3300 to 3800).

The softening point or melting point of the epoxy compound may be, for example, 75 ℃ or higher (e.g., 75 to 125 ℃), preferably 80 ℃ or higher (e.g., 80 to 115 ℃), more preferably 85 ℃ or higher (e.g., 90 to 110 ℃), or may be about 95 to 105 ℃.

The epoxy compound is usually solid at room temperature and is often in the form of powder.

The epoxy compound has improved adhesion to a base material such as a metal, and also has reactivity with an amino group of the polyamide resin, and therefore, adhesion to a base material such as a metal is greatly improved. In addition, the epoxy compound of the multimer (including a dimer, a trimer, and the like) may have a hydroxyl group (secondary hydroxyl group), and this hydroxyl group is involved in adhesion to a substrate such as a metal, and also has reactivity with a blocked polyisocyanate, and adhesion to the substrate can be further improved.

[ proportions of the respective Components ]

In the present invention, the amino group (and the carboxyl group) of the polyamide-based resin, the isocyanate group of the blocked polyisocyanate, and the epoxy group (and the hydroxyl group) of the epoxy compound are reacted in a complicated manner, and thereby the polyamide-based resin can be adhered to a substrate such as a metal with high adhesion. For example, typically, an isocyanate group of a blocked polyisocyanate reacts with an amino group of a polyamide-based resin (and a hydroxyl group of an epoxy compound), and an epoxy group of the epoxy compound reacts with an amino group of a polyamide-based resin (and a carboxyl group), thereby forming an adhesive layer (a cured film or a primer layer) on a substrate. Therefore, the ratio of each component and the ratio of the reactive group of each component become complicated.

The amount of the polyamide-based resin is selected depending on the concentration of the reactive group in each component, and may be, for example, about 50 to 95 mass% (e.g., 60 to 90 mass%), usually about 65 to 90 mass% (e.g., 65 to 85 mass%), preferably about 67 to 83 mass% (e.g., 70 to 80 mass%), or about 70 to 90 mass% (e.g., 75 to 85 mass%) with respect to 100 mass% of the total amount of the polyamide-based resin, the blocked polyisocyanate, and the epoxy compound. When the proportion of the polyamide-based resin is too small or too large, the adhesion to the substrate tends to be lowered.

The blocked polyisocyanate reacts with the amino group of the polyamide resin to greatly improve the mechanical strength and thermal characteristics of the adhesive layer and improve the adhesion to the base material. Therefore, the amount ratio of the polyamide-based resin to the blocked polyisocyanate may be selected according to the concentration, reactivity, and the like of the functional group (reactive group) of each component, and the ratio of the isocyanate group (blocked isocyanate group) of the blocked polyisocyanate to 1 mole of the amino group concentration of the polyamide-based resin may be, for example, about 0.5 to 7 moles (for example, 0.7 to 6 moles, preferably 1 to 5 moles), but is usually an excessive mole, and may be, for example, selected from a range of about 1.1 to 5.5 moles, and may be about 1.5 to 5 moles (for example, 1.75 to 4.5 moles), preferably 2 to 4 moles (for example, 2.25 to 3.75 moles), and more preferably 2.5 to 3.5 moles (for example, 2.75 to 3.4 moles). If the ratio of the blocked polyisocyanate is too low, adhesion to a base material such as a metal, heat resistance, and hot water resistance may be reduced, and if too high, the free polyisocyanate may remain, resulting in a reduction in the properties of the adhesive layer. Further, if an excessive amount of blocked polyisocyanate is used, even if the adhesive layer is cured, the adhesive layer functions as an active primer layer (active intermediate layer), and for this reason, the reactivity with a molding resin (for example, a thermoplastic resin having a reactive group such as a hydroxyl group or an amino group, for example, a polyester resin or a polyamide resin) in the composite molded member can be improved, and the adhesion to the molding resin can be improved.

Specifically, the concentration C of the isocyanate group (NCO) of the blocked polyisocyanate_NCO(mmol/kg) with the amino group concentration C of the polyamide resin_NH2The ratio (mmol/kg) is not particularly limited, and the concentration of the amino group may be excessive, but generally, the concentration of the isocyanate group is high, for example, relative to the amino group (NH)₂) The concentration (mmol/kg) of (D) is often excessive, and the concentration (mmol/kg) of the isocyanate group (NCO) is often excessive. Concentration of isocyanate group (C)_NCO) With amino group concentration (C)_NH2) A difference (Δ (C))_NCO-C_NH2) For example, it may be 15 to 450mmol/kg (for example, 20 to 400mmol/kg), preferably 30 to 300mmol/kg (for example, 35 to 250mmol/kg), and more preferably about 40 to 200mmol/kg (for example, 45 to 185mmol/kg), or may be 20mmol/kg or more, preferably 30mmol/kg or more, and more preferably 40mmol/kg or more. The total number of moles of isocyanate groups in the blocked polyisocyanate may be, for example, about 1.3 to 50 times (e.g., about 1.5 to 40 times), preferably about 2 to 35 times (e.g., about 2.5 to 25 times), more preferably about 2.7 to 15 times (e.g., about 3 to 10 times), and may be about 2.7 to 10 times (e.g., about 3 to 8.5 times) the total number of moles of amino groups in the polyamide resin.

The ratio of the blocked polyisocyanate to 100 parts by mass of the polyamide-based resin may be about 2.5 to 35 parts by mass, preferably about 5 to 30 parts by mass (for example, about 7.5 to 25 parts by mass), and more preferably about 10 to 20 parts by mass (for example, about 10 to 15 parts by mass).

The proportion of the epoxy group in the epoxy compound may be, for example, about 0.1 to 1 mol (e.g., about 0.2 to 0.9 mol), preferably about 0.2 to 0.8 mol (e.g., about 0.25 to 0.7 mol), more preferably about 0.3 to 0.6 mol (e.g., about 0.35 to 0.55 mol), or about 0.35 to 0.6 mol (e.g., about 0.4 to 0.5 mol) relative to 1 mol of the amino group concentration of the polyamide-based resin. The ratio (mmol/kg) of the carboxyl group of the polyamide-based resin to the epoxy group of the epoxy compound may be, for example, about 0.01/1 to 0.5/1 (e.g., about 0.02/1 to 0.4/1), preferably about 0.03/1 to 0.3/1 (e.g., about 0.04/1 to 0.2/1), and more preferably about 0.05/1 to 0.2/1 (e.g., about 0.06/1 to 0.15/1).

The ratio (mmol/kg) of the isocyanate group of the blocked polyisocyanate to the hydroxyl group (secondary hydroxyl group) of the epoxy compound may be, for example, about 0.5/1 to 1.5/1 (e.g., about 0.7/1 to 1.3/1), and preferably about 0.8/1 to 1.2/1 (e.g., about 0.9/1 to 1.1/1).

The mass ratio of the blocked polyisocyanate to the epoxy compound may be about 20/80 to 80/20, preferably about 30/70 to 70/30, and more preferably about 40/60 to 60/40.

Concentration C of epoxy group relative to the total amount (total number of moles) (mmol/kg) of amino group, isocyanate group and epoxy group_EPFor example, the amount of the organic solvent may be 2 to 40 mol% (e.g., 3 to 35 mol%), and usually 5 to 30 mol% (e.g., 5 to 25 mol%), preferably 7 to 25 mol% (e.g., 8 to 20 mol%), more preferably 10 to 20 mol% (e.g., 10 to 18 mol%), and may be at least 6 mol% or more, more preferably 8 mol% or more. In particular, at a concentration C relative to the amino groups_NH2Concentration C of isocyanate groups_NCOIs excessive as described above and has a concentration C of epoxy groups_EPWhen the ratio is the above ratio, not only the initial adhesion strength is high, but also the decrease in the adhesive strength can be suppressed even when immersed in hot water.

The proportion of the epoxy compound may be, for example, about 2.5 to 35 parts by mass, preferably about 5 to 30 parts by mass (for example, about 7.5 to 25 parts by mass), more preferably about 10 to 20 parts by mass (for example, about 10 to 15 parts by mass), or about 10 to 22 parts by mass, relative to 100 parts by mass of the polyamide-based resin. When the proportion of the epoxy compound is too small, the adhesion to a base material such as a metal is liable to be lowered, and when too large, the epoxy compound remains to deteriorate the characteristics of the adhesive layer. If an excess amount of epoxy compound is used, even if the adhesive layer is cured, the adhesive layer can function as an active primer layer (active intermediate layer), and for this reason, the reactivity with respect to a molding resin (for example, a thermoplastic resin having a reactive group such as a carboxyl group or an amino group, for example, a polyester resin or a polyamide resin) in a composite molded member may be improved, and the adhesion to the molding resin may be improved.

[ form of curable resin composition ]

The curable resin composition of the present invention may be a liquid composition (solution composition or dispersion) containing a solvent, or may have a powdery or granular form. The curable resin composition may be a mixture (powder mixture) of the powdery polyamide-based resin, the powdery blocked polyisocyanate, and the powdery epoxy compound, or may be in the form of a powder or a powder granule of a composition (integrally solidified composition) obtained by mixing the above components (the polyamide-based resin, the blocked polyisocyanate, and the epoxy compound).

The average particle diameter D of each component (polyamide-based resin, blocked polyisocyanate and epoxy compound) in the form of powder or granules is not particularly limited as long as the uniformity of the coating film is not impaired₅₀For example, the particle size may be selected from the range of about 1 to 300 μm, and is usually about 2 to 200 μm (e.g., 5 to 150 μm), preferably about 10 to 100 μm (e.g., 15 to 80 μm), and more preferably about 20 to 70 μm. Average particle diameter D₅₀The particle size distribution can be measured by a conventional method, for example, using a particle size distribution measuring apparatus based on a laser diffraction/scattering method.

The curable resin composition of the present invention may be in the form of a solution, but if it is in a solid form (powder or granular form), even if the amino group of the polyamide resin, the isocyanate group of the blocked polyisocyanate, and the epoxy group of the epoxy compound are reactive with each other, the reaction of the respective components can be suppressed, and the storage stability is high. As described above, the adhesive composition exhibits high adhesiveness and close adhesion to a base material (a base material such as a metal). Therefore, the curable resin composition of the present invention is effective for coating or coating a substrate (or a member) to protect the substrate with a coating film, thereby improving corrosion resistance, durability, and the like.

[ composite Member and method for producing the same ]

The composite member can be produced by applying the curable resin composition (adhesive resin composition) to the surface of a substrate (or a member) to form an adhesive layer (cured film or primer layer).

The kind of the base material is not particularly limited, and examples thereof include: metals (e.g., iron or iron alloys (stainless steel, etc.), aluminum or aluminum alloys, copper, zinc, etc.), ceramics (e.g., ceramics, magnetics, oxide-based ceramics, nitride-based ceramics, boride-based ceramics, etc.), plastics (thermosetting or photocurable resins such as epoxy resins, phenol resins, and polyimide resins, moldings of heat-resistant thermoplastic resins (engineering plastics and the like) such as polyarylate alkylene ester resins, polyarylate resins, aromatic polyamide resins, polycarbonate resins, polyurethane resins, thermoplastic polyimide resins, polyphenylene ether resins, polyether ketone resins, polyether ether ketone resins, polyphenylene sulfide resins, polysulfone resins, polyether sulfone resins, and liquid crystal plastics), wood, and the like, and the substrate may be a composite substrate (for example, a substrate having a vapor-deposited film or the like, a laminate substrate such as a laminate of the above metal and heat-resistant thermoplastic resin, and the like).

The preferred base material is a metal, for example, iron (steel plate or the like), aluminum, or an alloy thereof (stainless steel or the like). These substrates may be subjected to surface treatment depending on the type of the substrate, and for example, in the case of a metal substrate, treatment such as degreasing treatment, polishing treatment, electrolytic treatment, or rough surface treatment may be performed.

The coating of the substrate with the curable resin composition can be carried out by a conventional coating method, and the powder-form curable resin composition can be coated by a powder coating method such as a fluidized immersion method (a method of immersing a heated substrate such as a metal in a fluidized phase of a powder particle to form a coating film), an electrostatic powder coating, and an electrodeposition coating (cationic electrodeposition coating). In a thermal spraying method in which coating is performed through a melting step, there is a possibility that reactive groups of the respective components react with each other before forming a coating film by melting and heating. The electrostatic powder coating method may be an electrostatic powder spraying method, an electrostatic fluidized immersion method (in the fluidized immersion method, a method of forming a coating film by attracting and adhering powder by static electricity), or the like. In order to form a uniform coating film (adhesive layer) on the surface of the substrate, an electrostatic powder coating method which has a small thermal history and can suppress consumption of reactive groups of each component can be used.

The coating film can be usually formed by heating (or baking) or can be formed into a cured film in order to react the polyamide-based resin, the blocked polyisocyanate, and the epoxy compound. The heating temperature (or firing temperature) may be, for example, 170 to 270 ℃, preferably 180 to 250 ℃, and more preferably about 190 to 220 ℃. The heating time (or firing time) may be, for example, 1 to 10 minutes, preferably 2 to 8 minutes, and more preferably about 3 to 6 minutes.

The thickness of the coating film (adhesive layer or cured film) thus formed may be, for example, about 1 to 500. mu.m, usually about 5 to 250. mu.m, preferably about 10 to 200. mu.m, and more preferably about 25 to 175 μm (e.g., about 50 to 150 μm).

Such an adhesive layer not only exhibits high adhesion to a base material or a member, but also has high heat resistance, hot water resistance, and the like. Therefore, even if a thermoplastic resin is molded, a uniform molded part having high adhesion and durability can be suitably formed without generating voids at the interface between the base material and the adhesive layer (or cured film) regardless of molding conditions.

[ composite Molding Member and method for producing the same ]

The composite molded member can be produced by molding or laminating a composition containing at least a thermoplastic resin on the adhesive layer of the composite member (the composite member including the base material such as the metal base material and the adhesive layer formed on the surface of the base material).

The kind of the thermoplastic resin is not particularly limited, and examples thereof include: olefin resins (polyethylene resins, polypropylene resins, modified or copolymerized olefin resins, cyclic olefin resins, etc.), styrene resins (styrene copolymers such AS acrylonitrile-styrene resins (AS resins), impact-resistant polystyrene resins, rubber-reinforced styrene resins such AS acrylonitrile-styrene-butadiene resins (ABS resins), etc.), (meth) acrylic resins, vinyl acetate resins (or derivatives thereof, for example, polyvinyl alcohol resins, polyvinyl acetal resins, etc.), vinyl chloride resins, polyester resins (polyalkylene arylate resins such AS polyethylene terephthalate resins, polybutylene terephthalate resins, polyethylene naphthalate resins, etc.), polyarylate resins, etc.), polyamide resins, polycarbonate resins, etc, Polyurethane resins, thermoplastic polyimide resins, polyacetal resins, polyether resins (polyphenylene ether resins, polyether ketone resins, polyether ether ketone resins, etc.), polyphenylene sulfide resins, polysulfone resins (polysulfone resins, polyether sulfone resins, etc.), liquid crystal plastics (liquid crystal aromatic polyester resins, etc.), thermoplastic elastomers (olefin elastomers, styrene elastomers, polyester elastomers, polyamide elastomers, polyurethane elastomers, fluorine elastomers, etc.), etc., and depending on the application, rubbers (or unvulcanized rubber compositions) such as ethylene-propylene-diene rubbers may be used. These thermoplastic resins may be used alone, or two or more of them may be used in combination.

The thermoplastic resin may have a functionality (reactive group) such as a hydroxyl group, a carboxyl group, an amino group, a blocked isocyanate group, or the like. Since the adhesive layer is reactive, it is possible to expect that the adhesion is improved by a reaction with the molding resin or the laminate sheet. In particular, if reactive groups such as amino groups, isocyanate groups and/or epoxy groups (particularly, at least isocyanate groups) remain in the adhesive layer, the adhesive layer is active even when cured, and therefore, the reactive groups remaining in the adhesive layer can be reacted with the functionality (reactive groups) of the thermoplastic resin, thereby improving adhesion to the molding resin or the laminate sheet.

In the present invention, a thermoplastic resin having a melting point or glass transition temperature of the polyamide resin of the curable resin composition or less may be molded, but even if a thermoplastic resin having a higher melting point than the polyamide resin is molded, a resin molded portion or a laminated portion can be formed with high adhesion and durability without generating voids at the interface between a base material such as a metal and an adhesive layer. Therefore, in order to form a resin molded part or a laminated part having high heat resistance and durability, the thermoplastic resin may have a melting point or a glass transition temperature of the polyamide resin or higher. The melting point or glass transition temperature of such a thermoplastic resin may be, for example, about 100 to 350 ℃ (e.g., 160 to 330 ℃), preferably about 170 to 300 ℃ (e.g., 200 to 280 ℃), usually about 180 to 270 ℃ (e.g., 190 to 260 ℃), preferably about 200 to 250 ℃ (e.g., 200 to 240 ℃), depending on the kind of the thermoplastic resin.

The thermoplastic resin may be preferably an aromatic polyester resin such as an aromatic polyalkylene ester-series resin or an aromatic polyester-series resin having a hydroxyl group and/or a carboxyl group at the terminal, or a polyamide-series resin having an amino group and/or a carboxyl group at the terminal, and particularly, may be a polyamide-series resin having an amino group. The polyamide-based resin may be, for example: polyamide 46, polyamide 6, polyamide 66, alicyclic polyamide containing the alicyclic diamine component and/or alicyclic dicarboxylic acid component as polymerization components, polyamide MXD-6 (polyamide resin containing at least xylylenediamine and adipic acid as reaction components), amorphous polyamide (polyamide resin containing at least terephthalic acid and trimethylhexamethylenediamine as reaction components, and the like), and the like. The amino group concentration and the carboxyl group concentration of the polyamide resin are the same as described above.

The thermoplastic resin may contain various additives, as required, such as stabilizers (heat resistance stabilizers, weather resistance stabilizers, antioxidants, ultraviolet absorbers, and the like), colorants, magnets (paramagnetic bodies such as ferrites, and strong magnets such as magnets), fillers, reinforcing agents, plasticizers, lubricants, flame retardants, antistatic agents, silane coupling agents, and the like. The additives may be used alone, or two or more of them may be used in combination. The reinforcing agent may be a reinforcing agent in the form of powder such as calcium carbonate, barium sulfate, titanium oxide, silica, alumina, mica, clay, talc, or carbon black; the reinforcing agent may be a fibrous reinforcing agent such as organic fibers such as rayon, nylon, vinylon, and aramid, and inorganic fibers such as glass fibers, carbon fibers, metal fibers, and whiskers. The reinforcing agent is preferably a fibrous reinforcing agent such as glass fiber. The content of the reinforcing agent may be, for example, about 5 to 50 parts by mass, preferably about 10 to 40 parts by mass, based on 100 parts by mass of the thermoplastic resin.

The thermoplastic resin-containing composition may be molded (over molded) or formed with respect to the adhesive layer, or may be laminated in the form of a sheet. The molding of the thermoplastic resin composition can be carried out by conventional insert molding, and the thermoplastic resin composition is melted and injection molded to form a composite molded member in which a molded portion of the thermoplastic resin composition is formed on an adhesive layer of the composite member in a laminated state. For example, a composite molded body in which a resin layer, a magnet layer, a reinforcing layer, and the like are formed on a base material such as a metal can be prepared by melt-kneading a thermoplastic resin composition, a thermoplastic resin composition containing the magnet, a thermoplastic resin composition containing a reinforcing agent such as glass fiber, and the like, and injection-molding the resulting mixture with respect to the adhesive layer.

The thermoplastic resin composition may be formed by melt extrusion in the form of a sheet, or may be directly laminated or laminated in the form of a melt sheet on the adhesive layer; it is also possible to form a sheet or tape of a thermoplastic resin composition containing a reinforcing agent such as glass fiber (for example, an oriented sheet or tape in which a fibrous reinforcing agent is oriented in a predetermined direction (uniaxial-oriented (Uni-Directional) material or the like)) and directly laminate (heat-laminate) the formed sheet or tape with respect to the adhesive layer.

Examples

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

In the following examples and comparative examples, the following materials were used.

[ base Material ]

A steel plate (stainless steel plate SUS430 sold by Nippon Testpanel co., ltd.) was degreased and used.

[ Polyamide-based resin ]

PA 1: polyamide 12(Daicel Evonik, model K.K., water absorption: 0.25%, amino group concentration: 145mmol/kg, carboxyl group concentration: 4mmol/kg, powder: average particle size: 47 μm)

PA 2: copolyamide 6/6/12(Daicel Evonik Co., Ltd., water absorption 1.5%, amino group concentration 187mmol/kg, carboxyl group concentration 1.5mmol/kg, powder: average particle size 42 μm)

The water absorption was measured by the water absorption test specified in ASTM D570. The amino group concentration and the carboxyl group concentration were measured by the neutralization titration method described above. The average particle diameter is measured by freeze-pulverizing a polyamide resin and using a particle size distribution measuring apparatus using a laser diffraction/scattering method.

[ blocked isocyanate ]

B-I: blocked isocyanate (isocyanate dimer (Uretdione) polyisocyanate adduct "VESTAGON BF 1540" manufactured by Evonik corporation, isocyanate group concentration 3600mmol/kg, glass transition temperature below 84 ℃, powder)

The concentration of the isocyanate group is calculated from the isocyanate content.

[ epoxy Compound ]

EP 1: bisphenol A type epoxy resin (500 mmol/kg epoxy group concentration, 3600mmol/kg hydroxyl group concentration, powder, Mitsubishi chemical Co., Ltd.)

EP 2: bisphenol A type epoxy resin (Araldite GT7004 manufactured by Ciba-Geigy Co., Ltd., epoxy group concentration 1500mmol/kg, powder)

The concentration of epoxy groups is calculated from the epoxy equivalent weight, and the concentration of hydroxyl groups is calculated from the number of repeating units obtained from the molecular weight of the epoxy resin.

[ Molding resin ]

PA 3: "Amilan CM 1017" manufactured by Toyoli K.K., water absorption of 1.8% according to ASTM D570, amino group concentration of 37mmol/kg)

Examples and comparative examples

A polyamide resin powder, a blocked polyisocyanate powder, and an epoxy resin powder were mixed in the proportions shown in table 1 to prepare a powder mixture, and the degreased substrate was subjected to electrostatic coating with a thickness of about 100 μm, and heated in an oven at 185 ℃ for 5 minutes to form a coating film, thereby preparing a composite member.

A composite molded article was prepared by injection molding (insert molding) a molding resin PA3 at a cylinder temperature of 280 ℃ to form a resin layer having a thickness of 3mm, using an injection molding machine ("ET 40V" manufactured by Toyo mechanical Metal Co., Ltd.).

[ adhesive Strength ]

The adhesion strength of the resin layer of the obtained composite molded article to the substrate was measured in accordance with ISO 19095-2Type B.

[ Hot Water dipping test ]

The obtained composite molded article was immersed in hot water at 80 ℃ for 50 hours, and then the adhesive strength was measured in the same manner as described above.

The results are shown in Table 1. In table 1, "PA water absorption" represents the water absorption of the polyamide resin or the polyamide resin mixture, "NH₂(PA) "represents an amino group of a polyamide-based resin or a mixture of polyamide-based resins, and" NCO (B-I) "represents a blocked polyisocyanateIsocyanate group of cyanate ester (B-1), "Epoxy (EP)" represents epoxy group of epoxy compound, ". DELTA. (C)_NCO-C_NH2) "represents the concentration C of isocyanate groups in the blocked polyisocyanate (B-1)_NCOConcentration C of amino groups with the Polyamide resin (PA)_NH2The difference (unit: mmol/kg).

As is clear from table 1, the resin compositions used in the examples have a lower water absorption than the resin compositions used in the comparative examples, and therefore have high durable adhesion to hot water. In particular, if the adhesive layer is formed using a resin composition having a given epoxy group concentration and an excess of a given amount of the concentration of the isocyanate group of the blocked polyisocyanate over the amino group concentration of the polyamide-based resin, the molding resin layer can be formed with high adhesion. Comparative example 3 corresponds to the example of patent document 1.

Industrial applicability

The present invention is suitable for producing a composite molded article (hybrid member) in which a base material such as a metal and a resin are composited (mixed), and the composite molded article can be used for applications requiring high durability, for example: structural members of vehicles (such as automobiles), trains, airplanes, aircrafts, ships, and the like (transportation equipment or transportation means), running members (such as suspension systems, wheels, and brake devices), parts or members (such as structural members) of track structures, and the like. Specifically, the composite molded member can be applied to, for example, a structural member (an automobile part, a member, or the like) of a vehicle such as a front end (a bumper) or the like.