JP2024111650A - Composite molding - Google Patents

Abstract

To provide a composite molded body having excellent adhesion, sealing properties and mechanical properties.SOLUTION: There is provided a composite molded body in which a molded body A comprising a polyether polyamide elastomer (a1) or an elastomer composition (A) containing a polyether polyamide elastomer (a1) and a molded body B comprising a polyamide resin composition (B) containing an aliphatic polyamide resin (b1) and a reinforcing fiber (b2) are directly bonded, wherein the content of the polyether polyamide elastomer (a1) is more than 50 pts.mass and less than 100 pts.mass based on the total 100 pts.mass of the elastomer composition (A), the ratio of the constituent unit derived from a polyether compound in the polyether polyamide elastomer (a1) is 30 to 55 mass%, the content of the aliphatic polyamide resin (b1) is more than 50 pts.mass and less than 100 pts.mass based on the total 100 pts.mass of the polyamide resin composition (B) and the concentration of the terminal amino group in the aliphatic polyamide resin (b1) is 40 to 105 μmol/kg. In addition, the composite molded body can contribute to the achievement of Goal 9, 13 or the like of the SDGs (Sustainable Development Goals) from the viewpoint of contributing to the reduction of resource usage by reducing the weight of the molded body.SELECTED DRAWING: None

Description

The present invention relates to a composite molding.

Composite molded products, such as laminates in which metal and vulcanized rubber are bonded together with an adhesive, and parts in which vulcanized rubber is partially bonded to the edge of a metal, exhibit sealing properties due to the combined effect of the elasticity of the vulcanized rubber and the mechanical strength of the metal. For this reason, such composite molded products are used in the fields of sealing materials, sliding materials, and vibration-proof materials for automobile parts, industrial machinery, aircraft interior parts, household appliances, and construction materials.

Patent Document 1 discloses a composite molded body in which such metal and vulcanized rubber are laminated together with an adhesive.

On the other hand, there are attempts to replace composite molded bodies containing metals with resins, as described in Patent Document 1. Polyamide resins have excellent mechanical properties, heat resistance, and chemical resistance, and are widely used as structural members and housing materials for automobile parts, industrial machinery, electrical parts, etc. In addition, composite molded bodies are known in which a thermoplastic elastomer, which is a soft material, is heat-sealed to a hard material using polyamide resin in order to impart desired properties. Patent Document 2 discloses a thermoplastic resin composition that contains specific amounts of polyamide resin, polyether ester amide resin, and acid-modified polypropylene resin as a hard material using polyamide resin. Patent Document 2 also discloses a composite molded body in which a molded body of the above composition and a molded body of a thermoplastic elastomer, which is a soft material, are heat-sealed.

JP 2002-067216 A JP 2008-106249 A

However, the composite molding disclosed in Patent Document 1 requires an adhesive. There is a demand for reducing the number of processes that use adhesives.

The hard material using polyamide resin disclosed in Patent Document 2 contains a thermoplastic elastomer component, which is a soft material, so there may be problems with strength when used as a substitute for metal. Furthermore, adhesion between different resins, such as the hard material resin and the soft material resin, may be difficult.

In addition, composite moldings used as cushioning members in sliding members must be flexible enough to deform when colliding with other members. Furthermore, when such composite moldings are used for sealing purposes, they must have a sealing ability to prevent leakage of enclosed fluids such as lubricating oil.

Therefore, the present invention aims to provide a composite molded body that has excellent adhesiveness, sealing properties, and mechanical properties.

The present invention relates to the following:
[1] a molded body A made of a polyether polyamide elastomer (a1) or an elastomer composition (A) containing a polyether polyamide elastomer (a1);
A composite molded body in which a molded body B made of a polyamide resin composition (B) containing an aliphatic polyamide resin (b1) and reinforcing fibers (b2) is directly bonded to the molded body B,
the content of the polyether polyamide elastomer (a1) is more than 50 parts by mass and less than 100 parts by mass relative to a total of 100 parts by mass of the elastomer composition (A);
the ratio of structural units derived from a polyether compound in the polyether polyamide elastomer (a1) is 30 to 55% by mass,
The content of the aliphatic polyamide resin (b1) is more than 50 parts by mass and less than 100 parts by mass relative to a total of 100 parts by mass of the polyamide resin composition (B),
The aliphatic polyamide resin (b1) has a terminal amino group concentration of 40 to 105 μmol/kg.
Composite molding.
[2] The content of the aliphatic polyamide resin (b1) is 55 parts by mass or more and 85 parts by mass or less, and the content of the reinforcing fiber (b2) is 15 parts by mass or more and 45 parts by mass or less, relative to a total of 100 parts by mass of the polyamide resin composition (B). [1] The composite molding described in.
[3] The composite molding according to [1] or [2], wherein the reinforcing fiber (b2) is one or more selected from the group consisting of glass fiber, carbon fiber, and cellulose fiber.
[4] A method for producing the composite molded body according to any one of [1] to [3], comprising the steps of: Step 1-A and Step 2-A:
Step 1-A: a step of injection molding a polyether polyamide elastomer (a1) or an elastomer composition (A) containing the polyether polyamide elastomer (a1) to obtain a molded article A of the polyether polyamide elastomer (a1) or the elastomer composition (A) containing the polyether polyamide elastomer (a1);
Step 2-A: A step of injection-molding a polyamide resin composition (B) onto the whole or part of the surface of the molded body A to directly bond a molded body B of the polyamide resin composition (B) onto the molded body A;
Including,
A method for producing a composite molded body.
[5] A method for producing the composite molded body according to any one of [1] to [3], comprising the steps of: Step 1-B and Step 2-B:
Step 1-B: A step of injection molding the polyamide resin composition (B) to obtain a molded article B of the polyamide resin composition (B);
Step 2-B: a step of injection-molding polyether polyamide elastomer (a1) or an elastomer composition (A) containing polyether polyamide elastomer (a1) onto the whole or part of the surface of the molded body B, thereby directly bonding a molded body A of polyether polyamide elastomer (a1) or an elastomer composition (A) containing polyether polyamide elastomer (a1) onto the molded body B;
A method for producing a composite molded body, comprising:

The present invention provides a composite molded body that has excellent adhesion, sealing properties, and mechanical properties.

FIG. 1 is a plan view showing the shape of a test piece for evaluating adhesiveness. FIG. 2 is a side view showing the shape of a test piece for evaluating adhesiveness.

[Definition of terms]
The "polyether polyamide elastomer (a1)" is also referred to as the "component (a1)". The same applies to the "reinforcing fiber (b2)" and the like.
In this specification, the content of each component in a composition means, when multiple substances corresponding to each component are present in the composition, the total amount of those multiple substances present in the composition, unless otherwise specified.
In this specification, the use of "to" indicating a range of values means that the values before and after it are included as the lower and upper limits.

[Composite Molded Body]
In the composite molded product, molded product A and molded product B are directly bonded to each other. In the composite molded product, molded product A is made of a polyether polyamide elastomer (a1) or an elastomer composition (A) containing the polyether polyamide elastomer (a1). In the composite molded product, molded product B is made of a polyamide resin composition (B) containing an aliphatic polyamide resin (b1) and reinforcing fibers (b2). In the composite molded product, the content of the polyether polyamide elastomer (a1) is more than 50 parts by mass and less than 100 parts by mass relative to a total of 100 parts by mass of the elastomer composition (A), and the ratio of structural units derived from a polyether compound in the polyether polyamide elastomer (a1) is 30 to 55% by mass. In the composite molded product, the content of the aliphatic polyamide resin (b1) is more than 50 parts by mass and less than 100 parts by mass per 100 parts by mass of the polyamide resin composition (B), and the terminal amino group concentration of the aliphatic polyamide resin (b1) is 40 to 105 μmol/kg.

In the composite molded body, the content of polyether polyamide elastomer (a1) is more than 50 parts by mass and less than 100 parts by mass per 100 parts by mass of the elastomer composition (A), and the ratio of structural units derived from polyether compounds in the polyether polyamide elastomer (a1) is 30 to 55% by mass. When the ratio of structural units derived from polyether compounds in the polyether polyamide elastomer (a1) is 30 to 55% by mass, an elastomer with a suitable bending modulus is obtained. Therefore, it is considered that the elastic modulus of the obtained composite molded body is in a suitable range as a buffer member for a sliding member by containing a specific content of component (a1) having the ratio of structural units derived from polyether compounds described above.

In the composite molded body, the content of the aliphatic polyamide resin (b1) is more than 50 parts by mass and less than 100 parts by mass per 100 parts by mass of the polyamide resin composition (B), and the terminal amino group concentration of the aliphatic polyamide resin (b1) is 40 to 105 μmol/kg. The terminal amino group concentration of the aliphatic polyamide resin (b1) is 40 to 105 μmol/kg, resulting in a polyamide resin with an appropriate molecular weight. Therefore, it is considered that the mechanical properties (particularly the tensile breaking strain and Charpy impact strength) of the obtained composite molded body are improved by the molded body B containing a specific content of the component (b1) having the above-mentioned terminal amino group concentration. In addition, the polyamide resin composition (B) containing the reinforcing fiber (b2) tends to efficiently improve the mechanical properties.

The composite molded body is a composite molded body in which molded body A and molded body B are directly bonded together, and therefore can be a composite molded body with excellent adhesive strength without using an intermediate such as an adhesive. The adhesive strength of the composite molded body is considered to be generated by the reaction between the polyether portion of the polyether polyamide elastomer (a1) contained in molded body A and the amino group of the aliphatic polyamide resin (b1) contained in molded body B. That is, molded body A contains a specific content of component (a1) having the ratio of structural units derived from the polyether compound described above, and molded body B contains a specific content of component (b1) having the terminal amino group concentration described above, and thus the composite molded body in which molded body A and molded body B are directly bonded together has excellent adhesive strength.

[Molded body A]
The molded body A is made of a polyether polyamide elastomer (a1) or an elastomer composition (A) containing a polyether polyamide elastomer (a1).

<Polyether polyamide elastomer (a1)>
The polyether polyamide elastomer (a1) is preferably one obtained by polymerizing an aminocarboxylic acid and/or a lactam, a polyether compound, and a dicarboxylic acid.

<Aminocarboxylic acid and/or lactam>
The aminocarboxylic acid and the lactam are polyamide-forming monomers. The aminocarboxylic acid and the lactam are as described later in the aliphatic polyamide resin (b1).

<Polyether compounds>
The polyether compound is preferably one or more compounds selected from the group consisting of compounds represented by the following formula (1) and compounds represented by the following formula (2).

（式（１）中、ｘは１～２０の範囲の整数であり、ｙは４～５０の範囲の整数であり、ｚは１～２０の範囲の整数である）

(In formula (1), x is an integer ranging from 1 to 20, y is an integer ranging from 4 to 50, and z is an integer ranging from 1 to 20.)

（式（２）中、ｐは１～５０の範囲の整数である）

(In formula (2), p is an integer ranging from 1 to 50.)

Examples of the compound represented by formula (1) include XYX triblock polyether diamine compounds produced by adding propylene oxide to both ends of poly(oxytetramethylene) glycol or the like to produce polypropylene glycol, and then reacting the ends of the polypropylene glycol with ammonia or the like.

Specific examples of compounds represented by formula (1) include Jeffamine (registered trademark) XTJ-533 (in formula (1), x is about 12, y is about 11, and z is about 11), Jeffamine (registered trademark) XTJ-536 (in formula (1), x is about 8.5, y is about 17, and z is about 7.5), and Jeffamine (registered trademark) XTJ-542 (in formula (1), x is about 3, y is about 9, and z is about 2). In addition, examples of compounds represented by formula (1) include XYX-1 (in formula (1), x is about 3, y is about 14, and z is about 2), XYX-2 (in formula (1), x is about 5, y is about 14, and z is about 4), and XYX-3 (in formula (1), x is about 3, y is about 19, and z is about 2).

In the compound represented by formula (1), from the viewpoint of stably ensuring the elastic modulus or hardness of the polyether polyamide elastomer (a1) and the adhesiveness with the aliphatic polyamide resin (b1) in the polyamide resin composition (B), x and z are preferably independently 1 to 18, more preferably 1 to 16, even more preferably 1 to 14, and particularly preferably 1 to 12. y is 4 to 50, preferably 5 to 45, more preferably 6 to 40, even more preferably 7 to 35, and particularly preferably 8 to 30. In addition, the combination of "x, y, z" in the compound represented by formula (1) may be a combination in which x is 2 to 6, y is 6 to 12, and z is 1 to 5, or a combination in which x is 2 to 10, y is 13 to 28, and z is 1 to 9.

In the compound represented by formula (2), from the viewpoint of stably ensuring the elastic modulus or hardness of the polyether polyamide elastomer (a1) and the adhesion to the aliphatic polyamide resin (b1) in the polyamide resin composition (B), p is preferably 3 to 40, and particularly preferably 5 to 30.

<Dicarboxylic acid>
The dicarboxylic acid may be at least one dicarboxylic acid selected from aliphatic dicarboxylic acids and aromatic dicarboxylic acids, or a derivative thereof. Specific examples of the aliphatic dicarboxylic acid include aliphatic dicarboxylic acids described later in the aliphatic polyamide resin (b1), other aliphatic dicarboxylic acids such as dimerized aliphatic dicarboxylic acids (dimer acids) having 14 to 48 carbon atoms obtained by dimerizing unsaturated fatty acids obtained by fractional distillation of triglycerides, and hydrogenated products thereof (hydrogenated dimer acids), and alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid. Specific examples of the aromatic dicarboxylic acid include terephthalic acid and isophthalic acid.

Commercially available dimer acids and hydrogenated dimer acids include those manufactured by Uniqema under the trade names "Pripol (registered trademark) 1004," "Pripol 1006," "Pripol 1009," and "Pripol 1013."

<Preferred embodiment of polyether polyamide elastomer (a1)>
The ratio of the structural unit derived from the polyether compound in the polyether polyamide elastomer (a1) is 30 to 55% by mass. The ratio of the structural unit derived from the polyether compound in the polyether polyamide elastomer (a1) can be determined by the mass ratio (charge ratio) of the monomers used as raw materials. When the ratio of the structural unit derived from the polyether compound in the polyether polyamide elastomer (a1) is less than 30% by mass, the ether moiety for reacting with the polyamide resin (b1) is not present in sufficient quantity, so the adhesiveness tends to be poor. In addition, when the ratio of the structural unit derived from the polyether compound in the polyether polyamide elastomer (a1) is less than 30% by mass, the molded body A tends to be too hard, so that the desired elasticity cannot be obtained, and the sealing property tends to be poor. When the ratio of the structural unit derived from the polyether compound in the polyether polyamide elastomer (a1) is more than 55% by mass, there are too many polyether moieties for exerting elasticity, so that there is a concern of leakage of lubricating oil, and the sealing property tends to be poor. The proportion of structural units derived from a polyether compound in the polyether polyamide elastomer (a1) is preferably from 33 to 55 mass %, particularly preferably from 36 to 54 mass %.

From the viewpoint of superior sealing properties, the hardness (Shore D) of the polyether polyamide elastomer (a1) is preferably 37 to 50, more preferably 38 to 49, and particularly preferably 39 to 49. The hardness (Shore D) can be measured in accordance with ISO 868.

From the viewpoint of superior sealing properties, the flexural modulus of the polyether polyamide elastomer (a1) is preferably 80 to 500 MPa, more preferably 80 to 300 MPa, and particularly preferably 80 to 200 MPa. The flexural modulus can be measured in accordance with ISO 178.

<<Method for producing polyether polyamide elastomer (a1)>>
The method for producing the polyether polyamide elastomer (a1) may be any method as long as the desired components can be obtained. Examples of the method for producing the polyether polyamide elastomer (a1) include the methods described in WO2012/96136, WO2010/47315, and WO2009/57805.

The polyether polyamide elastomer (a1) may be one type of component or a combination of two or more types of components.

<Elastomer composition (A) containing polyether polyamide elastomer (a1)>
In the elastomer composition (A), the polyether polyamide elastomer (a1) is as described above.
The elastomer composition (A) may contain an additional component (hereinafter also referred to as "additional component (a2)") other than the polyether polyamide elastomer (a1) to the extent that the function and characteristics of the elastomer composition (A) are not impaired. Examples of such components include heat resistance agents, ultraviolet absorbers, light stabilizers, antioxidants, antistatic agents, lubricants, slipping agents, crystal nucleating agents, tackifiers, sealability improvers, antifogging agents, mold release agents, plasticizers, pigments, dyes, fragrances, flame retardants, reinforcing materials, and other resins. The other resins are resins having reactive functional groups or resins not having reactive functional groups. Here, examples of the reactive functional groups include acid anhydride groups. Specific examples of the resins include polyolefin resins, polyester resins, polyether resins, polyamide resins (excluding polyether polyamide elastomer (a1)), polyurethane resins, polycarbonate resins, and acrylic resins. The further component may be a component added during the production of the polyether polyamide elastomer (a1) or a component contained as an additive in a commercially available product of the polyether polyamide elastomer (a1). It is preferable that the elastomer composition (A) does not contain an aliphatic polyamide resin (b1).

<Composition of elastomer composition (A)>
The content of the polyether polyamide elastomer (a1) is more than 50 parts by mass and less than 100 parts by mass relative to a total of 100 parts by mass of the elastomer composition (A). From the viewpoint of not impairing the function and characteristics of the polyether polyamide elastomer (a1), the content of the polyether polyamide elastomer (a1) relative to a total of 100 parts by mass of the elastomer composition (A) is preferably 60 parts by mass or more and less than 100 parts by mass, more preferably 80 parts by mass or more and less than 100 parts by mass, and particularly preferably 90 parts by mass or more and less than 100 parts by mass. The remainder is the further component (a2).

[Molded body B]
The molded body B is made of a polyamide resin composition (B) containing an aliphatic polyamide resin (b1) and reinforcing fibers (b2).

<Polyamide resin composition (B)>
The polyamide resin composition (B) contains an aliphatic polyamide resin (b1) and reinforcing fibers (b2).

<Aliphatic polyamide resin (b1)>
The aliphatic polyamide resin (b1) is a polyamide resin having no aromatic ring. Examples of the aliphatic polyamide resin (b1) include an aliphatic homopolyamide resin (b1-1) and an aliphatic copolyamide resin (b1-2).

Aliphatic homopolyamide resin (b1-1)
The aliphatic homopolyamide resin (b1-1) means a polyamide resin in which the monomer component constituting the aliphatic polyamide resin is one type. Here, the monomer component constituting the aliphatic polyamide resin includes a combination of an aliphatic diamine and an aliphatic dicarboxylic acid, a lactam, or an aminocarboxylic acid. In addition, when the monomer component constituting the aliphatic polyamide resin is a combination of an aliphatic diamine and an aliphatic dicarboxylic acid, the combination of one type of aliphatic diamine and one type of aliphatic dicarboxylic acid is regarded as one type of monomer component.

The aliphatic diamine preferably has 2 to 20 carbon atoms, and more preferably has 4 to 12 carbon atoms. The aliphatic dicarboxylic acid preferably has 2 to 20 carbon atoms, and more preferably has 6 to 12 carbon atoms. The lactam preferably has 5 to 12 carbon atoms. The aminocarboxylic acid preferably has 5 to 12 carbon atoms.

Examples of aliphatic diamines include ethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, tridecanediamine, tetradecanediamine, pentadecanediamine, hexadecanediamine, heptadecanediamine, octadecanediamine, nonadecanediamine, and eicosanediamine. Examples of aliphatic dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedionic acid, dodecanedionic acid, tridecanedionic acid, tetradecanedionic acid, pentadecanedioic acid, hexadecanedioic acid, octadecanedioic acid, and eicosanedionic acid.

Examples of combinations of aliphatic diamines and aliphatic dicarboxylic acids include a combination of hexamethylenediamine and adipic acid, a combination of hexamethylenediamine and sebacic acid, and a combination of hexamethylenediamine and dodecanedioic acid. The combination of aliphatic diamines and aliphatic dicarboxylic acids is preferably an equimolar salt of the combination.

Examples of lactams include γ-butyrolactam, δ-valerolactam, ε-caprolactam, enantholactam, undecanelactam, and dodecanelactam. Examples of aminocarboxylic acids include 5-aminopentanoic acid, 6-aminohexanoic acid, 7-aminoheptanoic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. From the viewpoint of productivity, it is preferable that the lactam is ε-caprolactam, undecanelactam, or dodecanelactam.

Specific examples of aliphatic homopolyamide resins (b1-1) include polyvalerolactam (polyamide 5), polycaprolactam (polyamide 6), polyenantholactam (polyamide 7), polyundecane lactam (polyamide 11), polylauryl lactam (polyamide 12), polytetramethylene adipamide (polyamide 46), polytetramethylene dodecamide (polyamide 412), polypentamethylene adipamide (polyamide 56), polypentamethylene azelamide (polyamide 59), polypentamethylene sebacamide (polyamide 510), polypentamethylene dodecamide (polyamide 512), polyhexamethylene adipamide (polyamide 66), polyhexamethylene azelamide (polyamide 69), polyhexamethylene sebacamide (polyamide 610), polyhexamethylene adipamide (polyamide 67), polyhexamethylene azelamide (polyamide 69), polyhexamethylene sebacamide (polyamide 610), polyhexamethylene adipamide (polyamide 67), polyhexamethylene adipamide (polyamide 67), polyhexamethylene sebacamide (polyamide 67), polyhexamethylene adip ... Examples of such polyamides include samethylene dodecamide (polyamide 612), polynonamethylene adipamide (polyamide 96), polynonamethylene azelamide (polyamide 99), polynonamethylene sebacamide (polyamide 910), polynonamethylene dodecamide (polyamide 912), polydecamethylene adipamide (polyamide 106), polydecamethylene azelamide (polyamide 109), polydecamethylene decamamide (polyamide 1010), polydecamethylene dodecamide (polyamide 1012), polydodecamethylene adipamide (polyamide 126), polydodecamethylene azelamide (polyamide 129), polydodecamethylene sebacamide (polyamide 1210), polydodecamethylene dodecamide (polyamide 1212), and polydodecamethylene oxamide (polyamide 122).

Aliphatic copolymer polyamide resin (b1-2)
The aliphatic copolyamide resin (b1-2) is an aliphatic polyamide resin that has two or more kinds of monomer components constituting the aliphatic polyamide resin and has no aromatic ring. Thus, examples of the aliphatic copolyamide resin (b1-2) include aliphatic copolyamide resins that are copolymers of two or more kinds of monomers selected from the group consisting of a combination of an aliphatic diamine and an aliphatic dicarboxylic acid, and lactams and aminocarboxylic acids.

Specific examples of aliphatic copolymer polyamide resins (b1-2) include caprolactam/hexamethylenediaminoadipic acid copolymer (polyamide 6/66), caprolactam/hexamethylenediaminoazelaic acid copolymer (polyamide 6/69), caprolactam/hexamethylenediaminosebacic acid copolymer (polyamide 6/610), caprolactam/hexamethylenediaminoundecanoic acid copolymer (polyamide 6/611), caprolactam/hexamethylenediaminododecanoic acid copolymer (polyamide 6/612), caprolactam/aminoundecanoic acid copolymer (polyamide 6/ 11), caprolactam/lauryllactam copolymer (polyamide 6/12), caprolactam/hexamethylenediaminoadipic acid/lauryllactam copolymer (polyamide 6/66/12), caprolactam/hexamethylenediaminoadipic acid/hexamethylenediaminosebacic acid copolymer (polyamide 6/66/610), caprolactam/hexamethylenediaminoadipic acid/hexamethylenediaminododecanedicarboxylic acid copolymer (polyamide 6/66/612), hexamethylenediaminoadipic acid/caprolactam copolymer (polyamide 66/6), etc.

- Preferred embodiment From the viewpoint of molding processability, the aliphatic polyamide resin (b1) is preferably an aliphatic homopolyamide resin (b1-1), and is particularly preferably one or more selected from the group consisting of polyamide 5, polyamide 6, polyamide 11, polyamide 12, polyamide 46, polyamide 56, polyamide 510, polyamide 66, polyamide 610, and polyamide 612.

The terminal amino group concentration of the aliphatic polyamide resin (b1) is 40 to 105 μmol/kg. The terminal amino group concentration of the aliphatic polyamide resin (b1) can be measured by the method described in the Examples. When the terminal amino group concentration of the aliphatic polyamide resin (b1) is less than 40 μmol/kg, the amount of amino groups that can react with the polyether portion of the (a1) component contained in the molded body A is reduced, so that the adhesiveness tends to be inferior. When the terminal amino group concentration of the aliphatic polyamide resin (b1) exceeds 105 μmol/kg, the degree of polymerization of the polyamide resin itself does not increase, and the molecular weight is reduced, so that the resin tends not to have various properties as a high molecular weight resin. As a result, the mechanical properties of the obtained composite molded body, particularly the tensile breaking strain and Charpy impact strength, tend to be inferior. From the viewpoint of adhesiveness and mechanical properties, the terminal amino group concentration of the aliphatic polyamide resin (b1) is preferably 45 to 100 μmol/kg, and particularly preferably 60 to 100 μmol/kg.

In accordance with JIS K 6920, the aliphatic polyamide resin (b1) is preferably such that the relative viscosity measured at 25°C by dissolving 1 g of polyamide resin in 100 ml of 96% concentrated sulfuric acid is 1.9 or more, more preferably 1.9 to 4.2, and particularly preferably 2.3 to 3.2, from the viewpoint of moldability. When the aliphatic polyamide resin (b1) contains two or more aliphatic polyamide resins with different relative viscosities, the relative viscosity of the aliphatic polyamide resin is preferably measured as described above, but when the relative viscosity of each aliphatic polyamide resin and its mixing ratio are known, the average value calculated by multiplying each relative viscosity by the mixing ratio may be used as the relative viscosity of the aliphatic polyamide resin.

The aliphatic polyamide resin (b1) may be a single component or a combination of two or more components.

<Reinforcing fiber (b2)>
Examples of the reinforcing fiber (b2) include glass fiber, carbon fiber, cellulose fiber, alumina fiber, boron nitride fiber, aramid fiber, and polyparaphenylene benzobisoxazole fiber.
The glass fibers include glass fibers having a circular cross section perpendicular to the length direction and/or glass fibers having a non-circular cross section perpendicular to the length direction.
Examples of the carbon fiber include PAN-based carbon fiber, pitch-based carbon fiber, and phenol-based carbon fiber.
Examples of cellulose fibers include acetylated microfibrillated cellulose-based fibers described in JP 2021-36024 A and microfibrillated hydrophobic cellulose-based fibers described in WO 2019/163873 A.
From the viewpoints of handling during production and physical properties, the fiber length of the reinforcing fiber (b2) is preferably 1 mm or more and 6 mm or less, and particularly preferably 2 mm or more and 4 mm or less. Also, from the viewpoints of productivity and physical properties, the fiber diameter (average fiber diameter) of the reinforcing fiber (b2) is preferably 5 μm or more and 20 μm or less, and particularly preferably 5 μm or more and 15 μm or less.
From the viewpoint of mechanical properties, the reinforcing fiber (b2) is preferably one or more types selected from the group consisting of glass fiber, carbon fiber, and cellulose fiber.

<<Additional Ingredients>>
The polyamide resin composition (B) may contain an additional component (hereinafter also referred to as "additional component (b3)") other than the aliphatic polyamide resin (b1) and the reinforcing fiber (b2) to the extent that the function and characteristics of the polyamide resin composition (B) are not impaired. Examples of the additional component (b3) include other resins, inorganic compounds, nitrogen-containing compounds, plasticizers, heat resistance agents, foaming agents, weathering agents, crystal nucleating agents, antioxidants, crystallization accelerators, release agents, lubricants, antistatic agents, flame retardants, flame retardant assistants, pigments, dyes, glass fibers, carbon fibers (excluding recycled carbon fibers), cellulose fibers, aramid fibers, and other functionalizing agents. Examples of the additional resins include the resins described above in the elastomer composition (A). It is preferable that the polyamide resin composition (B) does not contain a polyether polyamide elastomer (a1).

<Composition of polyamide resin composition (B)>
The content of the aliphatic polyamide resin (b1) is more than 50 parts by mass and less than 100 parts by mass, and preferably 55 parts by mass or more and 85 parts by mass or less, based on 100 parts by mass of the polyamide resin composition (B).
The content of the reinforcing fiber (b2) is more than 0 parts by mass and less than 50 parts by mass relative to a total of 100 parts by mass of the polyamide resin composition (B). From the viewpoint of the mechanical properties of the molded body B, the content of the reinforcing fiber (b2) is preferably 15 parts by mass or more and 45 parts by mass or less relative to a total of 100 parts by mass of the polyamide resin composition (B).
The content of the further component (b3) is preferably 0 parts by mass or more and 30 parts by mass or less, more preferably 0 parts by mass or more and 20 parts by mass or less, and more preferably 0 parts by mass or more and 15 parts by mass or less, based on a total of 100 parts by mass of the polyamide resin composition (B).

[Method for producing polyamide resin composition]
The method for producing the polyamide resin composition is not particularly limited as long as it is a method capable of kneading each component, and examples thereof include production methods using a twin-screw extruder, a single-screw extruder, a multi-screw extruder, etc.

[Method of manufacturing composite molded body]
The method for producing the composite molded body is not particularly limited as long as the molded body A and the molded body B are directly bonded to each other. As the method for producing the composite molded body, a known production method including a step of heat-sealing the molded body A and the molded body B by integral molding can be used.

Specific methods for manufacturing the composite molded body include the following first and second manufacturing methods.

[First manufacturing method]
The first method for producing a composite molded body includes the following steps 1-A and 2-A:
Step 1-A: a step of injection molding a polyether polyamide elastomer (a1) or an elastomer composition (A) containing the polyether polyamide elastomer (a1) to obtain a molded article A of the polyether polyamide elastomer (a1) or the elastomer composition (A) containing the polyether polyamide elastomer (a1);
Step 2-A: A step of injection-molding a polyamide resin composition (B) onto the whole or part of the surface of the molded body A to directly bond a molded body B of the polyamide resin composition (B) onto the molded body A;
Includes.

<Step 1-A>
Step 1-A is a step of injection molding a polyether polyamide elastomer (a1) or an elastomer composition (A) containing the polyether polyamide elastomer (a1) to obtain a molded body A of the polyether polyamide elastomer (a1) or the elastomer composition (A) containing the polyether polyamide elastomer (a1). Step 1-A is a primary molding step.

<Injection molding method>
In step 1-A, the injection molding method is not particularly limited, and may be a method using a known injection molding machine. The injection molding machine is not particularly limited, and may be a screw in-line type injection molding machine, a plunger type injection molding machine, a screw pre-plastication type injection molding machine, etc. The polyether polyamide elastomer (a1) or the elastomer composition (A) containing the polyether polyamide elastomer (a1) heated and melted in the cylinder of the injection molding machine is measured for each shot, injected in a molten state into a mold, cooled and solidified in a predetermined shape, and then removed from the mold as a molded body.

<Injection molding temperature>
In step 1-A, the resin temperature when the polyether polyamide elastomer (a1) or the elastomer composition (A) containing the polyether polyamide elastomer (a1) is injection molded is not particularly limited, but is preferably equal to or higher than the melting point of the polyether polyamide elastomer (a1) or the elastomer composition (A) containing the polyether polyamide elastomer (a1), more preferably lower than "the melting point of the polyether polyamide elastomer (a1) or the elastomer composition (A) containing the polyether polyamide elastomer (a1) + 100°C", further preferably 190°C to 250°C, and particularly preferably 200°C to 240°C. In addition, the mold temperature when the elastomer composition (A) containing the polyether polyamide elastomer (a1) or the polyether polyamide elastomer (a1) is molded is preferably 40°C to 80°C. In addition, the mold temperature may be 50°C to 80°C.

<Step 2-A>
Step 2-A is a step of injection-molding a polyamide resin composition (B) onto the whole or part of the surface of the molded body A, thereby directly bonding a molded body B of the polyamide resin composition (B) onto the molded body A. Step 2-A is a secondary molding step.

<Injection molding method>
In step 2-A, the injection molding method is the same as that described above in step 1-A.

<Direct bonding method>
In step 2-A, a method for directly bonding a molded article A of the polyether polyamide elastomer (a1) or an elastomer composition (A) containing the polyether polyamide elastomer (a1) to a molded article B of the polyamide resin composition (B) includes a method of welding the molded article A to the molded article B. As such a method, an injection welding method is appropriately selected depending on the shape and/or intended use of the desired molded article. Here, examples of the injection welding method include two-color molding such as die slide injection (DSI) and die rotary injection (DRI).

In step 2-A, the conditions for directly bonding molded body A and molded body B (hereinafter simply referred to as "direct bonding") are preferably as follows:

In step 2-A, the molding resin temperature of the polyamide resin composition (B) is preferably equal to or higher than the melting point of the polyamide resin composition (B), more preferably less than "melting point of the polyamide resin composition (B) + 100°C", even more preferably 250°C to 300°C, and particularly preferably 270°C to 290°C. The mold temperature during direct bonding is preferably 40°C to 90°C, more preferably 40°C to 80°C, and particularly preferably 50°C to 80°C. The mold temperature may be 60°C to 90°C. The contact time of each molded body during direct bonding can be appropriately set according to the temperature of each molded body, but is preferably 8 seconds to 40 seconds, more preferably 8 seconds to 30 seconds, and particularly preferably 10 seconds to 15 seconds. The holding pressure during direct bonding is preferably 30 to 120 MPa, and particularly preferably 50 to 100 MPa. The holding time of the holding pressure is not particularly limited as long as it is the time during which the gate of the polyamide resin composition (B) solidifies.

[Second manufacturing method]
The second method for producing a composite molded body includes the following steps 1-B and 2-B:
Step 1-B: A step of injection molding the polyamide resin composition (B) to obtain a molded article B of the polyamide resin composition (B);
Step 2-B: a step of injection-molding polyether polyamide elastomer (a1) or an elastomer composition (A) containing polyether polyamide elastomer (a1) onto the whole or part of the surface of the molded body B, thereby directly bonding a molded body A of polyether polyamide elastomer (a1) or an elastomer composition (A) containing polyether polyamide elastomer (a1) onto the molded body B;
Includes.

<Step 1-B>
Step 1-B is a step of obtaining a molded article B of the polyamide resin composition (B) by injection molding the polyamide resin composition (B).
In step 1-B, the injection molding method is the same as that described above in step 1-A.
In step 1-B, the resin temperature when the polyamide resin composition (B) is injection molded and the mold temperature when the polyamide resin composition (B) is molded are as described above in step 2-A.

<Step 2-B>
Step 2-B is a step of injection-molding polyether polyamide elastomer (a1) or an elastomer composition (A) containing polyether polyamide elastomer (a1) onto the whole or part of the surface of the molded body B, thereby directly bonding a molded body A of polyether polyamide elastomer (a1) or an elastomer composition (A) containing polyether polyamide elastomer (a1) onto the molded body B.
In step 2-B, the injection molding method is the same as that described above in step 1-A.
In step 2-B, the method of direct bonding is as described above in step 2-A.
In step 2-B, the molding resin temperature of the polyether polyamide elastomer (a1) or the elastomer composition (A) containing the polyether polyamide elastomer (a1) is as described above in step 1-A.
In step 2-B, the mold temperature during direct bonding is as described above in step 1-A.
In step 2-B, the contact time of each molded body during direct bonding and the holding pressure during direct bonding are as described above in step 2-A. The holding time of the holding pressure is not particularly limited as long as it is a time during which the gate of the polyether polyamide elastomer (a1) or the elastomer composition (A) containing the polyether polyamide elastomer (a1) is solidified.

[Preferred embodiment]
The method for producing the composite molded body is preferably the first production method, and is preferably a production method by a two-color injection molding method in which, in step 1-A, a polyether polyamide elastomer (a1) is injection molded to obtain a molded body A of the polyether polyamide elastomer (a1), and then the mold is immediately rotated or slid, and, in step 2-A, a polyamide resin composition (B) is injection molded to directly bond (thermally fuse) molded body B onto the molded body A.

[Applications of composite molded bodies]
The composite molding may be a composite molding that requires sealing properties, a composite molding that requires mechanical properties (particularly tensile breaking strain and/or Charpy impact strength), or a composite molding that requires sealing properties and mechanical properties. The composite molding is preferably used as a sealing member and a member that requires sliding properties and vibration resistance. As a member that requires sealing properties, sliding properties, and vibration resistance, it is preferable to use it as a reciprocating member that is used as a sealing member or a sliding member for oil or liquid. In addition, as a member that requires vibration resistance, it is preferable to use it as a vibration-proof clamp or a support for automobiles, industrial machines, electrical parts, robots, etc.

The shapes of molded body A and molded body B may be any shape as long as the desired composite molded body can be obtained, and may be plate-like, sheet-like, block-like, etc. The shape of the composite molded body may be any shape as long as all or part of the surface of molded body A is directly bonded to all or part of the surface of molded body B, and may be appropriately set depending on the application of the composite molded body. The composite molded body may be a laminate.

The composite molded body is lighter and has superior strength characteristics than a composite molded body in which metal and vulcanized rubber are laminated. The thermoplastic resin composition can contribute to achieving Goals 9 and 13 of the SDGs (Sustainable Development Goals) from the viewpoint of contributing to a reduction in resource consumption by reducing the weight of the molded body.

The present invention will be specifically explained using the following examples and comparative examples, but the present invention is not limited to these.

<Evaluation>
1) Ratio of structural units derived from polyether compounds: Calculated from the raw material composition ratio.
2) Shore D hardness: Test pieces were prepared by injection molding at 230 to 250° C. in accordance with ISO 527, and the Shore D hardness was measured in an atmosphere of 23° C. and 50% humidity using a durometer hardness tester (type D) in accordance with ISO 868.
3) Flexural modulus: A type B test piece was prepared based on ISO294-1, and a bending test was carried out at 23° C. based on ISO178.
4) Terminal amino group concentration: 1 g of polyether polyamide elastomer was dissolved in 40 ml of a phenol/methanol mixed solvent (volume ratio: 9/1), and thymol blue was added to the obtained sample solution as an indicator. The solution was titrated with 0.02 mol/L hydrochloric acid to measure the terminal amino group concentration.
5) Nominal tensile strain at break: A tensile test was carried out using a test piece in an atmosphere at 23° C. based on ISO 527-1, 2.

<Ingredients>
The following ingredients were used:
1. Polyether polyamide elastomer (PAE)
PAE1: Ratio of structural units derived from polyether compounds: 60.0% by weight, Shore D hardness: 35, flexural modulus: 60 MPa, manufactured by UBE Co., Ltd. PAE2: Ratio of structural units derived from polyether compounds: 52.6% by weight, Shore D hardness: 40, flexural modulus: 90 MPa, manufactured by UBE Co., Ltd. PAE3: Ratio of structural units derived from polyether compounds: 38.5% by weight, Shore D hardness: 48, flexural modulus: 150 MPa, manufactured by UBE Co., Ltd. PAE4: Ratio of structural units derived from polyether compounds: 26.3% by weight, Shore D hardness: 55, flexural modulus: 260 MPa, manufactured by UBE Co., Ltd. PAE5: Ratio of structural units derived from polyether compounds: 10.5% by weight, Shore D hardness: 63, flexural modulus: 560 MPa, manufactured by UBE Co., Ltd. PAE6: Ratio of structural units derived from polyether compounds: 7.0% by weight, Shore D hardness: 68, flexural modulus: 850 MPa, manufactured by UBE Co., Ltd.

2. Aliphatic polyamide resin:
PA6-1: Polyamide 6 (terminal amino group concentration 110.0 μmol/kg, manufactured by UBE Co., Ltd.)
PA6-2: Polyamide 6 (terminal amino group concentration 95.0 μmol/kg, manufactured by UBE Co., Ltd.)
PA6-3: Polyamide 6 (terminal amino group concentration: 39.5 μmol/kg, manufactured by UBE Co., Ltd.)

3. Reinforcement fibers:
Glass fiber (GF) ECS03T-249H (cross-sectional shape: circular, average fiber diameter 10.5 μm, manufactured by Nippon Electric Glass Co., Ltd.)

<Production of polyamide resin composition (B)>
The aliphatic polyamide resin and reinforcing fibers shown in Table 1 were melt-kneaded in a Coperion ZSK32Mc twin-screw kneader to obtain pellets of the intended polyamide resin composition (B).

Example 1
(1) Preparation of Test Piece A test piece (composite molded body by two-color injection molding) having the shape of an ASTM No. 1 dumbbell test piece was obtained in the following steps 1 and 2. Fig. 1 is a plan view showing the shape of the test piece for evaluating the adhesion test, and Fig. 2 is a side view showing the shape of the test piece for evaluating the adhesion test. Here, the test piece is composed of part 1 (Fig. 1, Fig. 2: 1) and part 2 (Fig. 1, Fig. 2: 2).
(1-1) Step 1
Using an injection molding machine (SE100D-C160S manufactured by Sumitomo Heavy Industries, Ltd., mold clamping force 100 tons, screw diameter 28 mm), a metal piece having the shape of part 2 in FIG. 1 was inserted into a mold, and primary molding of polyether polyamide elastomer (a1) was performed under conditions of a cylinder temperature of 200° C., a mold temperature of 40° C., and an injection speed of 50 mm/sec, to obtain a molded product A of polyether polyamide elastomer (a1) having the shape of part 1.
(1-2) Step 2
The molded body A of the polyether polyamide elastomer (a1) obtained in step 1 was preheated at 80°C for 30 minutes. Thereafter, the molded body A of the polyether polyamide elastomer (a1) was inserted into the mold with the metal piece insert in the shape of the part 2 removed. The polyamide resin composition (B) was used to perform secondary molding of the polyamide resin composition (B) under the conditions of a cylinder temperature of 290°C, a mold temperature of 80°C, an injection speed of 100 mm/sec, and a holding pressure of 100 MPa, to obtain a molded body B of the polyamide resin composition (B) having the shape of the part 2. Thereafter, the molded body was removed from the mold through a cooling process to obtain a test piece. In the test piece, the boundary surface between the part 1 (molded body A of the polyether polyamide elastomer (a1)) and the part 2 (molded body B of the polyamide resin composition (B)) was melt-bonded at the time of injection of the polyamide resin composition (B).

<Example 2, Comparative Examples 1 to 6>
Test pieces for each example were obtained in the same manner as in Example 1, except that the components were changed as shown in the table.

<Adhesion evaluation>
The test pieces obtained in each example were subjected to measurement of the nominal tensile break strain (%) at a chuck distance of 160 mm and a tensile test speed of 50 mm/min under conditions of an atmosphere of 23°C and 50% RH to evaluate the adhesion. When molded body A and molded body B (i.e., part 1 and part 2) peeled off from each other in the test piece, the test piece was evaluated as "not bonded."
◯: The nominal tensile strain at break is 50% or more.
×: The nominal tensile strain at break is less than 50%.

<Evaluation of Adhesion After Hot Water Treatment>
The test piece was immersed in hot water at 80° C. for 6 hours. The nominal tensile break strain (%) was measured under the same conditions as above to evaluate the adhesion. When molded body A and molded body B (i.e., part 1 and part 2) peeled off from each other in the test piece, the test piece was evaluated as "not bonded."
Good: The nominal tensile strain at break is 20% or more.
×: The nominal tensile strain at break is less than 20%.

<Sealing performance evaluation>
The sealing property was evaluated from the flexural modulus of the polyether polyamide elastomer (PAE).
Good: The flexural modulus of the polyether polyamide elastomer is 80 MPa or more and 500 MPa or less.
×: The flexural modulus of the polyether polyamide elastomer is less than 80 MPa or more than 500 MPa.

<Mechanical property evaluation>
The mechanical properties of the aliphatic polyamide resin were evaluated based on the terminal amino group concentration.
◯: The terminal amino group concentration of the aliphatic polyamide resin is 105 μmmol/kg or less.
×: The terminal amino group concentration of the aliphatic polyamide resin is more than 105 μmmol/kg.

The results are shown in Table 1.

As can be seen from Table 1, the composite moldings of the examples had excellent adhesion.
A comparison between Examples 1 and 2 revealed that the greater the ratio of the structural units derived from the polyether compound in the polyether polyamide elastomer (a1), the better the adhesiveness.
The composite molding of Comparative Example 1 was inferior in adhesion after hot water treatment because an aliphatic polyamide resin having a terminal amino group concentration of less than 40 μmol/kg was used.
The composite molded bodies of Comparative Examples 2 to 4 were inferior in adhesion because they used polyether polyamide elastomers with a ratio of structural units derived from polyether compounds of less than 30% by mass. The polyether polyamide elastomers used in Comparative Examples 3 to 4 had a bending modulus of more than 500 MPa because the ratio of structural units derived from polyether compounds was significantly less than 30% by mass. This means that the composite molded bodies of Comparative Examples 3 to 4 have inferior sealing properties. The polyether polyamide elastomers used in Comparative Examples 3 to 4 had a ratio of structural units derived from polyether compounds of significantly less than 30% by mass, so the amount of polyether moieties to react with amino groups was small, and adhesion was greatly impaired.
The polyether polyamide elastomer used in Comparative Example 5 had a flexural modulus of less than 80 MPa because the ratio of the structural unit derived from the polyether compound exceeded 55% by mass. This indicates that the composite molding of Comparative Example 5 had poor sealing properties.
The aliphatic polyamide resin used in Comparative Example 6 was a low molecular weight component because the terminal amino group concentration was more than 105 μmol/kg. This indicates that the composite molding of Comparative Example 6 was inferior in mechanical properties.

1: Part 1
2: Part 2

Claims (5)

a molded body A made of a polyether polyamide elastomer (a1) or an elastomer composition (A) containing a polyether polyamide elastomer (a1);
A composite molded body in which a molded body B made of a polyamide resin composition (B) containing an aliphatic polyamide resin (b1) and reinforcing fibers (b2) is directly bonded to the molded body B,
the content of the polyether polyamide elastomer (a1) is more than 50 parts by mass and less than 100 parts by mass relative to a total of 100 parts by mass of the elastomer composition (A);
the ratio of structural units derived from a polyether compound in the polyether polyamide elastomer (a1) is 30 to 55% by mass,
The content of the aliphatic polyamide resin (b1) is more than 50 parts by mass and less than 100 parts by mass relative to a total of 100 parts by mass of the polyamide resin composition (B),
The aliphatic polyamide resin (b1) has a terminal amino group concentration of 40 to 105 μmol/kg.
Composite molding. The composite molding according to claim 1, wherein the content of the aliphatic polyamide resin (b1) is 55 parts by mass or more and 85 parts by mass or less, and the content of the reinforcing fiber (b2) is 15 parts by mass or more and 45 parts by mass or less, relative to a total of 100 parts by mass of the polyamide resin composition (B). The composite molding according to claim 1 or 2, wherein the reinforcing fiber (b2) is one or more selected from the group consisting of glass fiber, carbon fiber, and cellulose fiber. A method for producing the composite molded body according to claim 1 or 2, comprising the steps of: Step 1-A and Step 2-A:
Step 1-A: a step of injection molding a polyether polyamide elastomer (a1) or an elastomer composition (A) containing the polyether polyamide elastomer (a1) to obtain a molded article A of the polyether polyamide elastomer (a1) or the elastomer composition (A) containing the polyether polyamide elastomer (a1);
Step 2-A: A step of injection-molding a polyamide resin composition (B) onto the whole or part of the surface of the molded body A to directly bond a molded body B of the polyamide resin composition (B) onto the molded body A;
Including,
A method for producing a composite molded body. A method for producing the composite molded article according to claim 1 or 2, comprising the steps of:
Step 1-B: A step of injection molding the polyamide resin composition (B) to obtain a molded article B of the polyamide resin composition (B);
Step 2-B: a step of injection-molding polyether polyamide elastomer (a1) or an elastomer composition (A) containing polyether polyamide elastomer (a1) onto the whole or part of the surface of the molded body B, thereby directly bonding a molded body A of polyether polyamide elastomer (a1) or an elastomer composition (A) containing polyether polyamide elastomer (a1) onto the molded body B;
Including,
A method for producing a composite molded body.

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