JP2005119207A - Composite molding and its production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To directly and firmly join a polyamide resin member and a thermoplastic polyurethane resin member which are different in properties together by a simple method. <P>SOLUTION: In a composite molding, a resin member constituted of a polyamide resin and a resin member constituted of a thermoplastic polyurethane resin are joined together directly. Each of the polyamide resin and the polyurethane resin has polyether segments. The composite molding can be produced by heating at least one of the polyamide resin and the polyurethane resin and joining both together. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is a composite in which a resin member composed of a polyamide-based resin having a polyether segment and a resin member composed of a thermoplastic polyurethane-based resin having a polyether segment are integrally joined without using an adhesive. The present invention relates to a molded body and a manufacturing method thereof.

  In order to improve the design and decoration, or to give a good feel (for example, soft feel), a composite (composite molded product) combining resins having different hardnesses, for example, at least a part of the resin molded product A composite molded body coated with a thermoplastic elastomer has been proposed. Such a composite molded body is usually produced by bonding a plurality of molded members via an adhesive. For example, Patent Document 1 discloses a welded resin molded product in which a plurality of resin molded products formed of polyamide resin or the like are welded via a surface treatment agent such as a urethane polymer or a urethane adhesive. However, such a method using an adhesive is not only uneconomical due to the long process, but also causes environmental pollution due to organic solvents and the like.

  On the other hand, from the viewpoint of rationalizing the manufacturing process and environmental measures, a method of heat-sealing a plurality of molded members is also employed. A composite molded body by heat fusion is usually manufactured by a molding method such as two-color molding or insert molding. However, combinations of dissimilar materials that can be heat-sealed are greatly limited, and it is not easy to set molding conditions for obtaining sufficient bonding strength. Therefore, in combination with heat fusion, the fusion part is reinforced by combining the method of providing uneven parts on the composite part of the molded member and mechanically joining, and the method of applying a primer to the joined (fused) part. ing. However, in such a method, the flexibility of the composite molded body is lowered, and for example, the primer layer becomes hard and easily cracks due to bending. Further, in the manufacturing process, it becomes necessary to make the structure of the molded member complicated, and the number of manufacturing processes increases.

In order to solve these problems, the use of thermoplastic polyurethane as a material for the resin member constituting the composite molded body has been studied. Thermoplastic polyurethane itself is relatively excellent in adhesiveness. For example, in a shoe application, a composite plastic molded body composed of a polyamide resin and a thermoplastic polyurethane has been put to practical use as a shoe sole. Further, in Patent Document 2, a thermoplastic elastomer molded article is obtained by injection molding a polyamide elastomer containing a foaming agent in a state in which a molded article of a thermoplastic resin such as polyetheramide, polyetherester or polyurethane is housed in a mold. It is disclosed that a lightweight shoe sole can be obtained by bonding (non-light weight plastic) and an elastomer (light weight thermoplastic elastomer). Patent Document 3 discloses a composite molded article obtained by coating a hard plastic molded member formed of a blend of polypropylene and polyamide with a soft plastic containing a thermoplastic polyurethane and a plasticizer by heat fusion. . However, even in such a composite molded body (for example, a composite molded body using a polyurethane resin), the adhesive strength between two types of materials (for example, the adhesive strength with a polyamide elastomer as a counterpart material) is not yet sufficient. It is greatly affected by the molding conditions and conditions of the materials used (for example, production lots) and the usage environment of the product (composite molded product), and the adhesive strength and life as a composite molded product (especially the life of the bonded part) It is unstable.
JP-A-8-267585 (Claims) Japanese National Patent Publication No. 8-505333 (Claims) JP-A-7-125155 (Claims)

  Accordingly, an object of the present invention is to provide a composite molded body in which both the polyamide resin member and the thermoplastic polyurethane resin member having different properties are directly and firmly joined without using an adhesive, and the like. It is to provide a manufacturing method.

  Another object of the present invention is to provide a method for producing a composite molded body in which a polyamide-based resin member and a thermoplastic polyurethane-based resin member are firmly heat-sealed by a simple method without going through a complicated manufacturing process. There is to do.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors can increase the affinity between both resins by combining a polyamide-based resin and a thermoplastic polyurethane-based resin having polyether segments with each other. The present invention was completed by finding that each resin member can be firmly bonded.

That is, the composite molded body of the present invention is a composite molded body in which a resin member composed of a polyamide-based resin and a resin member composed of a thermoplastic polyurethane-based resin are directly bonded to each other. Each plastic polyurethane-based resin has a polyether segment. The polyamide-based resin may be made of a polyamide elastomer having a polyoxy C _2-4 alkylene segment as a soft segment. The thermoplastic polyurethane resin may be composed of a thermoplastic polyether urethane elastomer having a polyoxy C _2-4 alkylene segment as a soft segment. Further, at least one of the polyamide-based resin and the thermoplastic polyurethane-based resin may include at least a polytetramethylene glycol unit (polytetramethylene ether unit). The polyamide-based resin may be composed of a polyamide elastomer including a polyamide segment and a polyether segment, and the ratio (weight ratio) of the polyamide segment to the polyether segment is the former / the latter = 9/1 to It may be 2.5 / 7.5. In addition, the ratio of the polyether segment in the polyamide-type resin which comprises a resin member, and the thermoplastic polyurethane-type resin which comprises a resin member may be about 10 to 90 weight% with respect to the whole resin, respectively.

  The composite molded body of the present invention is suitable for a shoe or roll component.

  Such a composite molded article can be manufactured by heating at least one of the polyamide-based resin and the thermoplastic polyurethane-based resin and bonding the other. For example, a thermoplastic polyurethane-based resin may be heated and melted, and the molten thermoplastic polyurethane-based resin may be bonded to at least a part of a resin member made of a polyamide-based resin, and the polyamide-based resin may be joined. The resin may be heated and melted and bonded by bringing the molten polyamide-based resin into contact with at least a part of a resin member made of a thermoplastic polyurethane-based resin. Alternatively, the polyamide-based resin and the thermoplastic polyurethane-based resin may be heated and melted, and the molten polyamide-based resin and the molten thermoplastic polyurethane-based resin may be brought into contact with each other to be joined. Further, the polyamide-based resin and the thermoplastic polyurethane-based resin may be joined in the molding process by a molding method selected from thermoforming, injection molding, extrusion molding, and blow molding.

  In this specification, “resin” is used to mean “resin composition”. Further, in this specification, “adhesion” means a technique for combining a plurality of members via an adhesive, and “joining” means a technique for combining a plurality of members without using an adhesive. Means to distinguish between the two. (Heat) fusion is a form of bonding.

  In the present invention, the polyamide resin and the thermoplastic polyurethane resin both having a polyether segment are combined, and therefore the polyamide resin and the thermoplastic polyurethane resin member having different properties can be combined with the polyamide resin and the thermoplastic resin. Affinity with the polyurethane-based resin can be increased, and direct and strong bonding can be performed without using an adhesive. Further, a composite molded body in which the polyamide-based resin and the thermoplastic polyurethane-based resin member are firmly heat-sealed can be manufactured by a simple method without going through a complicated manufacturing process.

[Composite molded body]
The composite molded body of the present invention is composed of a resin member composed of a polyamide-based resin and a resin member joined directly to the polyamide-based resin member and composed of a thermoplastic polyurethane-based resin. Both the resin and the thermoplastic polyurethane resin have a polyether segment.

(Polyamide resin)
The polyamide resin has at least a polyether segment [polytetramethylene glycol (PTMG, polytetramethylene ether) segment or unit, polyoxy C _2-4 alkylene segment or unit such as polyethylene glycol, polypropylene glycol, etc.]. It consists of At least one (particularly polyamide resin) of the polyamide resin and the thermoplastic polyurethane resin may contain at least a PTMG unit.

As such a polyamide-based resin, a component having a polyether segment as at least a part of components of the polyamide (diamine, dicarboxylic acid, aminocarboxylic acid, etc.) [for example, a polyoxy C _2-4 alkylene unit. Diamine, dicarboxylic acid, aminocarboxylic acid, etc. having]]. The polyamide resin having the polyether segment includes a polyamide component having a reactive end group (polyamide block or segment) and a polyether component having a reactive end group with respect to the reactive end group (polyether). Also included is a polyamide block copolymer (that is, a polyamide elastomer having a polyether component as a soft segment) obtained by reaction with a block or segment).

  Such polyamide elastomers include, for example, a polyamide obtained by reaction of a polyamide component having a terminal carboxyl group and a polyether component having a terminal amino group, a polyamide component having a terminal amino group, and a polyether having a terminal carboxyl group Also included are polyamides obtained by reaction with components, polyamides obtained by reaction of polyamide components having terminal carboxyl groups and polyether components having terminal hydroxyl groups.

Examples of the polyether component having a reactive end group include a component having a terminal amino group [polyoxy C _2-4 alkylene diamine (polyoxyethylene diamine etc.)], a component having a terminal carboxyl group (polyoxy C _2-4 alkylene glycol). Dicarboxylic acid half ester, etc.), components having terminal hydroxyl groups such as polyoxy C _2-4 alkylene glycol [polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, block copolymers of these polyoxyalkylene glycols ( Polyoxyethylene-polyoxypropylene block copolymers, etc.); alkylene oxide adducts of aromatic diols (bisphenol A-C _2-4 alkylene oxide adducts, etc.)] can be used The

  Examples of the polyamide component having a reactive end group include aliphatic polyamides, alicyclic polyamides, aromatic polyamides, and various homopolyamides and copolyamides can be used.

Among the aliphatic polyamides, homopolyamides include aliphatic diamine components (C _6-12 alkylene diamines such as tetramethylene diamine, hexamethylene diamine, and dodecane diamine) and aliphatic dicarboxylic acid components (adipic acid, sebacic acid, Condensates (for example, polyamide 46, polyamide 66, polyamide 610, polyamide 612, polyamide 1010, etc.), lactams (ε-caprolactam, ω-laurolactam, etc.) with C _6-14 alkylenedicarboxylic acid such as dodecanedioic acid Homopolyamides (for example, polyamide 6, polyamide 11, polyamide 12, etc.) of amino carboxylic acids (such as amino carboxylic acids having about 4 to 16 carbon atoms such as ω-aminoundecanoic acid) Etc. can be exemplified. Further, as the copolyamide, a copolyamide obtained by copolymerization of monomer components capable of constituting a polyamide such as the aliphatic diamine component, aliphatic dicarboxylic acid component, lactam and aminocarboxylic acid, for example, 6-aminocaproic acid and 12-amino Copolymer with dodecanoic acid; copolymer of 6-aminocaproic acid, 12-aminododecanoic acid, hexamethylenediamine and adipic acid; copolymerization of hexamethylenediamine, adipic acid, hydrogenated dimer acid and 12-aminododecanoic acid Polyamide 6/11, polyamide 6/12, polyamide 66/11, polyamide 66/12 and the like.

Examples of the alicyclic polyamide include at least alicyclic diamine and alicyclic dicarboxylic acid (C _5-10 cycloalkane-dicarboxylic acid such as cyclohexane-1,4-dicarboxylic acid and cyclohexane-1,3-dicarboxylic acid). Homopolyamide or copolyamide having at least one selected from the group consisting of, for example, alicyclic diamine and / or diamine as a component of at least a part of the diamine component and dicarboxylic acid component constituting the polyamide resin. Alternatively, an alicyclic polyamide obtained by using an alicyclic dicarboxylic acid can be used. As the diamine component and the dicarboxylic acid component, together with the alicyclic diamine and / or alicyclic dicarboxylic acid, the above-exemplified aliphatic diamine and / or aliphatic dicarboxylic acid are usually used in combination. Such an alicyclic polyamide has high transparency and is known as a so-called transparent polyamide. Of the alicyclic polyamides, preferred are condensates (homo or copolyamides) of the aliphatic dicarboxylic acids and alicyclic diamines.

Examples of the alicyclic diamine include diamino C _5-10 cycloalkane such as diaminocyclohexane; bis (4-aminocyclohexyl) methane, bis (4-amino-3-methylcyclohexyl) methane, 2,2-bis (4 ′ And bis (amino C _5-8 cycloalkyl) C _1-3 alkane such as -aminocyclohexyl) propane.

  The aromatic polyamide includes a polyamide in which at least one of the aliphatic diamine component and the aliphatic dicarboxylic acid component is an aromatic component, for example, a polyamide [MXD-6 or other aromatic compound in which the diamine component is an aromatic component. Condensates of aromatic diamines (such as metaxylylenediamine) and aliphatic dicarboxylic acids], polyamides whose dicarboxylic acid component is an aromatic component [aliphatic diamines (such as trimethylhexamethylenediamine) and aromatic dicarboxylic acids (terephthalic acid) , Isophthalic acid and the like) and the like.

  As the polyamide component, a polyamide having dimer acid as a dicarboxylic acid component, a polyamide having a branched structure using a small amount of polyfunctional polyamine and / or polycarboxylic acid component, modified polyamide (N-alkoxymethyl polyamide, etc.), etc. May be used.

  The polyamide component includes a wholly aromatic polyamide (poly (m-phenylene isophthalamide) or the like) in which the diamine component and the dicarboxylic acid component are aromatic components together with the aliphatic, alicyclic and / or aromatic polyamides. Polyamide (aramid) or the like may be used in combination.

  These polyamide components may be used alone or in combination of two or more. Preferred polyamides include at least aliphatic polyamides.

  You may use the polyamide-type resin which has the said polyether segment individually or in combination of 2 or more types.

  The number average molecular weight of the polyamide-based resin having a polyether segment is about 6,000 to 100,000, preferably about 8,000 to 50,000, and more preferably about 10,000 to 30,000.

  The ratio of the polyether segment may be, for example, about 10 to 90% by weight, preferably about 20 to 90% by weight, and more preferably about 30 to 90% by weight, with respect to the entire polyamide resin constituting the resin member. . In the polyamide elastomer, the ratio (weight ratio) between the polyamide segment and the polyether segment (such as PTMG segment) is not particularly limited. For example, the former / the latter = 9/1 to 2/8, preferably 9 / It may be 1 to 2.5 / 7.5, more preferably 8/2 to 3/7, particularly 7/3 to 4/6.

  Moreover, the ratio (weight ratio) of the polyether segment in the polyamide resin constituting the resin member is, for example, 1/10 to 10/1 with respect to the polyether segment in the thermoplastic polyurethane resin constituting the resin member. Preferably it may be about 1/8 to 8/1, more preferably about 1/5 to 5/1.

The polyamide-based resin having a polyether segment may have a terminal amino group (free amino group, —NH ₂ ) or a terminal carboxyl group. Commercially available polyamide elastomers having polyether segments usually have few amino groups. The carboxyl group concentration of the polyamide-based resin having a polyether segment is not particularly limited, and is, for example, about 0.1 to 200 mmol / kg, preferably about 0.5 to 150 mmol / kg, more preferably about 1 to 100 mmol / kg. It may be.

  For example, commercially available polyamide elastomers and the like often have almost no amino group, and thus may not sufficiently improve the bondability with a thermoplastic polyurethane resin. In such a case, even when the amino group and / or imino group-containing component is contained in at least one of the polyamide-based resin and the thermoplastic polyurethane-based resin constituting the resin member, the bondability between the resin members can be improved. Good. Examples of such amino group and / or imino group-containing components include other polyamide resins (polyamide resins having terminal amino groups, for example, conventional polyamides such as the above-mentioned aliphatic, alicyclic or aromatic polyamides) And a low molecular weight amine compound having a high amino group concentration such as an amino group-containing polyamide oligomer).

Examples of the amine compound include various amine compounds that can be mixed with a polyamide-based resin having a polyether segment, such as polyamines [diamines (aliphatic diamines, alicyclic diamines, aromatic diamines, etc. exemplified above), diethylenetriamines]. , Polyamines such as aliphatic polyamines such as polyalkylene polyamines such as triethylenetetramine (poly _C2-3 alkylene polyamines, etc.), and relatively low molecular weight amine compounds such as polyamide oligomers can be used. An amine compound can be used individually or in combination of 2 or more types. Of these, polyamide oligomers are particularly preferable from the viewpoint of bondability.

  As the polyamide oligomer, a polyamide having a relatively low molecular weight obtained by adjusting a polycondensation condition or the like by using a conventional method, for example, the exemplified polyamide component can be used. For example, as a raw material polyamide component, a combination of the exemplified diamine [aliphatic diamine (alkylene diamine, etc.), alicyclic diamine, aromatic diamine, etc.] and dicarboxylic acid (aliphatic dicarboxylic acid, aromatic dicarboxylic acid, etc.) A combination of the diamine and / or dicarboxylic acid and a lactam (such as a lactam having about 4 to 20 carbon atoms such as ω-laurolactam) may be used. The polyamide oligomer can be obtained, for example, by heating and stirring the lactam and the aliphatic diamine under pressure.

  The number average molecular weight of the polyamide oligomer is, for example, 500 to 10,000, preferably 500 to 8,000 (for example, 1,000 to 7,000), and more preferably about 1,000 to 5,000. 2,000 to 6,000 (for example, 3,000 to 6,000). As the polyamide oligomer, for example, when a relatively high molecular weight oligomer having a number average molecular weight of 1,000 to 10,000, preferably 2,000 to 9,000, more preferably 3,000 to 8,000 is used, a thermoplastic polyurethane is used. It is also possible to improve the bondability.

  The polyamide oligomer usually does not need to have a free amino group, but preferably has a free amino group. When the polyamide oligomer has a free amino group, it may have an amino group at at least one end of the main chain, may have an amino group at both ends of the main chain, and may have a branched chain. It may have an amino group.

  The amino group concentration of the amine compound may be, for example, about 10 to 1000 mmol / kg (preferably 30 to 700 mmol / kg, particularly 50 to 500 mmol / kg).

  The ratio of the amine compound (especially polyamide oligomer) is, for example, about 0.01 to 10 parts by weight, preferably about 0.1 to 8 parts by weight, particularly about 100 parts by weight of the polyamide-based resin having a polyether segment. About 0.5 to 7 parts by weight. If the proportion of the amine compound is too large, the properties of the resin may be impaired, particularly when a polyamide-based resin is used as the hard resin.

  The amino group concentration in the polyamide resin (or resin composition) constituting the resin member is not particularly limited, and is, for example, 0 to 100 mmol / kg, preferably 0 to 50 mmol / kg, more preferably about 0 to 30 mmol / kg. It may be.

  As long as the effect of the present invention is not impaired, the polyamide resin member is made of other resins (polyester resin, polycarbonate resin, polysulfone resin, polyimide resin, polyketone resin, polyolefin resin, styrene resin, (meta ) Acrylic resins, thermoplastic resins such as halogen-containing vinyl resins, etc.), various additives such as fillers or reinforcing agents (reinforced fibers, etc.), stabilizers (UV absorbers, antioxidants, thermal stabilizers, etc.) , Colorants, plasticizers, lubricants, flame retardants, antistatic agents and the like may be included.

  As the composite molded body of the present invention is manufactured, the product may be warped due to the difference in molding shrinkage between the resin members. When the degree of warpage correction is large, the joint portion is broken. Or a stress crack may occur in each resin member. Therefore, it is preferable that the polyamide resin has low crystallinity.

  For example, the ultimate crystallinity of the polyamide block copolymer is 40% or less (for example, about 5 to 40%), preferably 35% or less (for example, about 5 to 35%), and more preferably 30% or less (for example, If adjusted to about 10 to 30%, it is advantageous in that the warpage hardly occurs in the combination with the thermoplastic polyurethane resin member, and it can be approximated to the flexibility of the thermoplastic polyurethane resin.

  In addition, “attainment crystallinity” means that a sample resin is heated to a temperature 20 ° C. higher than the melting point of this resin using a precision hot press, and then cooled to room temperature at a cooling rate of 3 ° C./min. This refers to the degree of crystallinity measured by X-ray diffraction analysis using a flat plate having a thickness of 1 mm. The melting point of the resin is a melting point measured by a DSC apparatus (differential scanning calorimetry apparatus) according to JIS K7122.

  In the polyamide elastomer having a polyamide homopolymer as a hard segment, the ultimate crystallinity can be adjusted by the abundance ratio of the hard segment and the soft segment.

(Polyurethane resin)
The thermoplastic polyurethane resin constituting the resin member is composed of a thermoplastic polyurethane resin having at least a polyether segment.

  In the thermoplastic polyurethane resin constituting the resin member, the proportion of the polyether segment is, for example, 10 to 90% by weight, preferably 20 to 90% by weight, more preferably 30%, based on the whole thermoplastic polyurethane resin. It may be about -90% by weight.

  The thermoplastic polyurethane-based resin having a polyether segment can be obtained, for example, by a reaction between a diisocyanate and a diol having a polyether unit and, if necessary, a chain extender.

  Diisocyanates include aliphatic diisocyanates such as hexamethylene diisocyanate (HMDI) and 2,2,4-trimethylhexamethylene diisocyanate; 1,4-cyclohexane diisocyanate, dicycloalkylmethane-4,4′-diisocyanate, isophorone diisocyanate Alicyclic diisocyanates such as (IPDI); aromatic diisocyanates such as phenylene diisocyanate, tolylene diisocyanate (TDI), diphenylmethane-4,4′-diisocyanate (MDI), and araliphatic diisocyanates such as xylylene diisocyanate, etc. Can be illustrated. As diisocyanates, compounds in which an alkyl group (for example, a methyl group) is substituted on the main chain or ring may be used. Diisocyanates can be used alone or in combination of two or more.

Diols having polyether units include polyether diols [aliphatic polyether diols such as poly (oxy C _2-4 alkylene) glycols such as polyethylene glycol, poly (oxytrimethylene) glycol, polypropylene glycol, and PTMG. , Block copolymers of these poly (oxyalkylene) glycols (polyoxyethylene-polyoxypropylene block copolymers, etc.); aromatic polyether diols, for example, aromatic diols, such as bisphenol A-alkylene oxide adducts alkylene oxide adducts (ethylene oxide, such as C _2-4 alkylene oxide adduct of propylene oxide), etc.]; polyester Geo as part of the polyester ether diol (a diol component Le (e.g., polyester diol described later) polyether diol using) such as is available. These diols can be used alone or in combination of two or more. Of these diols, aliphatic polyether diols such as polyethylene glycol and PTMG are preferred.

A polyester diol may be used in combination with the diol having a polyether unit. Examples of the polyester diol include a C _4-12 aliphatic dicarboxylic acid component (such as adipic acid), a C _2-12 aliphatic diol component (such as ethylene glycol, propylene glycol, butane diol, and neopentyl glycol), C _4-12 lactone. Polyester diols (aliphatic polyester diols) obtained from components (such as ε-caprolactone), such as poly (ethylene adipate), poly (1,4-butylene adipate), poly (1,6-hexane adipate), poly- ε-caprolactone and the like can be mentioned.

Examples of chain extenders include glycols [short chain glycols such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol and other C _2-10 alkylene diols; bishydroxyethoxybenzene (BHEB ) Etc.] and other diamines [aliphatic diamines such as C _2-10 alkylene diamines such as ethylene diamine, trimethylene diamine, tetramethylene diamine and hexamethylene diamine; alicyclic diamines such as isophorone diamine; Aromatic diamines such as range amines] can also be used. A chain extender can be used individually or in combination of 2 or more types.

  In addition to the completely thermoplastic polyurethane obtained by using diols and diisocyanates in a substantially equivalent ratio, the thermoplastic polyurethane resin was obtained by using a small excess of diisocyanates with respect to the diols. Also included are incomplete thermoplastic polyisocyanates in which a small amount of free (unreacted) isocyanate remains.

  Among thermoplastic polyurethane-based resins, in particular, thermoplastic polyether urethane elastomers obtained using diols having polyether units, diisocyanates, and glycols (such as short-chain glycols) as chain extenders preferable. This thermoplastic polyether urethane elastomer has a hard segment (hard block) composed of polyurethane of glycols and diisocyanates and a soft segment (soft block) composed of aliphatic polyether diol (polyethylene glycol, PTMG, etc.). ). The thermoplastic polyurethane resin may contain at least a PTMG unit as a polyether segment.

  The thermoplastic polyurethane resin having a polyether segment can be used alone or in combination of two or more.

  As described in the section of the polyamide-based resin, the thermoplastic polyurethane-based resin constituting the resin member may contain the amino group and / or imino group-containing component (particularly an amine compound such as an amino group-containing polyamide oligomer). Good. The ratio of the amino group and / or imino group-containing component (particularly, amine compounds such as amino group-containing polyamide oligomers) is, for example, 0.01 to 10 with respect to 100 parts by weight of the thermoplastic polyurethane resin having a polyether segment. About 1 part by weight, preferably about 0.1 to 8 parts by weight, especially about 0.5 to 7 parts by weight.

  The thermoplastic polyurethane-based resin member may be made of other resins (thermoplastic resins, in particular, thermoplastic elastomers such as polyamide-based elastomers, polyester-based elastomers, polyolefin-based elastomers, etc.) and stabilizers as long as the effects of the present invention are not impaired. Heat stabilizers, ultraviolet absorbers, antioxidants, etc.), plasticizers, lubricants, fillers, colorants, flame retardants, antistatic agents and the like.

  In the composite molded body of the present invention, both the polyamide-based resin and the thermoplastic polyurethane-based resin have a polyether segment, and since the affinity between the two resins is high, the polyamide-based resin can be used without using an adhesive. And the thermoplastic polyurethane resin are firmly bonded. The bonding strength is usually 30 N / cm or more, and there is a case where cohesive failure occurs due to peeling between a polyamide-based resin member (for example, a hard resin member) and a thermoplastic polyurethane-based resin member (for example, a soft resin member). is there. The joint strength of such a composite molded body is usually 30 N / cm to cohesive failure, preferably 40 N / cm or more, particularly 50 N / cm or more (50 N / cm or more to cohesive failure).

[Method for producing composite molded body]
The composite molded body of the present invention can be produced by joining a polyamide resin and a thermoplastic polyurethane resin under heating. Usually, it can join by heating and melting at least one of a polyamide-based resin and a thermoplastic polyurethane-based resin and bringing both resins into contact with each other. Such a composite molded body may be, for example, thermoforming (hot press molding, injection press molding, etc.), injection molding (insert injection molding, two-color injection molding, core back injection molding, sandwich injection molding, etc.), extrusion molding (co-molding). Extrusion molding, T-die laminate molding, etc.) and a conventional molding method such as blow molding can be used to join a polyamide resin and a thermoplastic polyurethane resin in the molding process.

  For example, in molding methods such as insert injection molding and injection press molding, a thermoplastic polyurethane resin is heated and melted, and the molten thermoplastic polyurethane resin is used as at least a part of a resin member made of a polyamide resin. It may be molded while being in contact with each other, and the polyamide resin is heated and melted, and this molten polyamide resin is brought into contact with at least a part of a resin member made of a thermoplastic polyurethane resin. You may shape | mold and join both. In molding methods such as two-color injection molding and coextrusion molding, the polyamide resin and the thermoplastic polyurethane resin are heated and melted to bring the molten polyamide resin into contact with the molten thermoplastic polyurethane resin. However, it may be molded and both may be joined. After melting at least one of the resins, bringing the polyamide-based resin and the thermoplastic polyurethane-based resin into contact with each other and bonding them, the polyamide-based resin member and the polyurethane-based resin member are firmly bonded by cooling, usually. A joined composite molded body can be obtained. Moreover, what is necessary is just to join at least one part with the polyamide-type resin member and the thermoplastic polyurethane-type resin member according to the objective, a use, etc.

  The resin can be melted by heating to a temperature equal to or higher than the melting point of the resin. However, in the case of a resin that does not substantially crystallize, the resin is heated to a temperature equal to or higher than the glass transition point (Tg) of the resin. Can be melted.

  In the present invention, both the polyamide-based resin and the thermoplastic polyurethane-based resin have polyether segments, so the affinity between the two resins is high, and even a composite molded body using different materials can be bonded. The strength can be greatly improved.

  As described above, which of the polyamide resin and the polyurethane resin is melted is not particularly limited, and generally a soft resin (polyurethane resin) having a lower melting point or glass transition point (Tg) is heated, A soft resin and a hard resin member composed of a hard resin (polyamide resin) having a higher melting point or Tg may be joined. Generally, a hard resin (polyamide resin) having a higher melting point or Tg is heated. The hard resin may be joined with a soft resin member made of a soft resin (polyurethane resin) having a lower melting point or Tg.

  Among these methods, in particular, the former method can exhibit the effects of the present invention characteristically and effectively, and is advantageous compared to the existing technology. In the existing technology based on mere physical heat fusion, when the previously molded polyamide resin member and the polyurethane resin to be molded later are joined, the molding temperature of the polyurethane resin is the same as that of the previously molded polyamide resin. In many cases, the temperature is lower than the melting point of the resin, and the thermal fusion does not easily proceed. Even when the molding temperature of the polyurethane resin is higher than the melting point of the polyamide resin, the amount of heat is often insufficient to melt the surface of the polyamide resin member. Therefore, in the existing technology, generally, a method of molding a polyamide resin member cannot be taken prior to molding of a polyurethane resin. However, even in such a case, according to the present invention, the polyamide resin member and the thermoplastic polyurethane resin can be more easily separated by the action of the polyether segment contained in the polyamide resin and the thermoplastic polyurethane resin. Therefore, the degree of freedom in the manufacturing process of the composite can be increased, and the manufacturing process can be greatly rationalized.

  In the present invention, the hard resin is usually a polyamide resin and the soft resin is often a thermoplastic polyurethane resin. However, the hard resin is a thermoplastic polyurethane resin, and the soft resin is a polyamide resin. Also good. Moreover, the hardness of a polyamide-type resin and a thermoplastic polyurethane-type resin may be comparable.

  More specifically, in the hot press molding, at least one of a hard resin (or composition) and a soft resin (or composition) is melted in a press mold, and both are brought into contact and pressed. To form a composite molded body. In hot press molding, the hard resin and / or soft resin may be filled into a mold in the form of pellets or powder, and is mounted on the mold as a molded product shaped in advance by another molding method. Also good.

  In the insert injection molding method, one of a hard resin (or resin composition) and a soft resin (or resin composition) is molded by a molding method such as injection molding, extrusion molding, sheet molding, film molding, and the like. After the formed molded product is stored in the mold, a composite molded product can be manufactured by injection molding the other into the gap between the molded product and the mold. In the insert injection molding, it is preferable to preheat the molded product stored in the mold.

  In the two-color injection molding method, two or more injection molding machines are used to inject one of hard resin (or resin composition) and soft resin (or resin composition) into a mold, A composite molded body can be manufactured by exchanging the cavity of the mold by rotating or moving the mold, and injection-molding the other component into the gap formed between the obtained molded product and the mold.

  In the core back injection molding method, either one of the hard resin (or resin composition) and the soft resin (or resin composition) is injection-molded into a mold, and the cavity volume of the mold is expanded. A composite molded body can be produced by injection molding the other component into the gap formed between the obtained molded product and the mold.

  Among these molding methods, in particular, from the viewpoint of mass productivity, hot press molding methods such as injection press molding methods, injection molding methods (insert injection molding method, two-color injection molding method, core back injection molding method, sandwich injection method) The molding method is suitable.

  In thermal fusion, the melting temperature (or thermal fusion temperature) of the hard resin and / or soft resin can be selected according to the type of both resins (or resin composition). For example, in the hot press molding method, 100 to 250. C., preferably 120 to 230.degree. C., more preferably about 150 to 220.degree. In the injection molding method, the temperature of the resin in the molding machine cylinder may be, for example, 200 to 300 ° C, preferably 220 to 280 ° C, and more preferably about 240 to 280 ° C.

  The structure and shape of the composite molded body are not particularly limited, but are structures suitable for design, decoration, touch, etc., for example, a structure in which a part or all of a soft resin member is covered or laminated with a hard resin member. Ordinarily, a structure in which a part or all of a hard resin member is covered or laminated with a soft resin member (for example, a structure in which a contact portion between a hard resin member and a human body (hand, etc.) is covered with a soft resin member, etc. Etc.) are preferred. Specific examples of the structure include a two-dimensional structure (sheet shape, plate shape, etc.), a three-dimensional structure (eg, rod shape, tube shape, casing, housing, etc.).

  In the present invention, a hard resin and a soft resin can be directly and strongly bonded by heat fusion without going through complicated manufacturing processes (a process of providing an uneven part in a composite part, an adhesive application process, etc.). In addition, it is excellent in properties such as designability, decorativeness, and good touch (soft touch, flexibility, etc.), and a lightweight and tough composite molded body can be easily obtained.

  The composite molded body of the present invention can be used for various industrial parts such as automobile parts (instrument panels, center panels, center console boxes, door trims, pillars, assist grips, handles, airbag covers, automobile interior parts; moldings, bumpers, etc. Automotive exterior parts such as: Rack and pinion boots, suspension boots, automotive functional parts such as constant velocity joint boots, etc.), home appliance parts (vacuum cleaner bumpers, remote control switches, OA (office automation) key tops, etc.), underwater Products used (underwater glasses, underwater camera covers, etc.), industrial parts (cover parts; industrial parts with various packing for sealing, waterproofing, soundproofing, vibration-proofing, etc .; industrial rubber rollers, etc.) , Electrical and electronic parts (curled cord wire covering, belt Hose, tube, such as mute gear), sporting goods, shoe parts (athletic shoes, shoe soles, etc.), parts requiring design properties and decorative properties (for example, sunglasses, eyeglasses, etc.) can be used, for example.

  Among these, the composite molded body is particularly suitable for a constituent member of a shoe or a roll (such as a rubber roller). Shoe components include shoe parts such as soles and shoe uppers. Also, composite shoes form athletic shoes, work shoes (boots, rain shoes, gardening shoes, etc.), etc. May be. In such a shoe application, it becomes easy to combine a polyamide resin reinforced with hard or glass fiber, which has been difficult in the past, and a soft polyurethane resin. For example, multiple layers of different grade materials are used. Can also be combined, making a great contribution to improving the design and functionality of shoes.

  In roll (rubber roller etc.) applications, for example, at least the surface layer is composed of a shaft (shaft) composed of a polyamide-based resin and a thermoplastic polyurethane-based resin layer formed on the peripheral surface of the shaft. Also good. The shaft may be formed with a polyamide-based resin layer on the surface of the metal shaft, or may be a shaft made of a polyamide-based resin. In such a roller application, the cutting process for obtaining shaft accuracy and the surface finish of the thermoplastic polyurethane resin can be finished in one process with the same polishing machine, so the manufacturing process of the roller can be greatly shortened and the cost can be reduced. Can be drastically reduced. In addition, since such a roller is chemically bonded, the bonding force is high, and there is almost no deviation between the shaft and the roll, so that it can withstand use at a high torque.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

(Evaluation of heat-fusibility)
The composite molded bodies obtained in Examples and Comparative Examples were cut into a size of 20 mm in width and 100 mm in length, and a tensile test was performed by pulling a grip allowance at a pulling speed of 20 mm / min in the direction of 180 ° C. The peel strength at the interface was measured, and the heat bondability between the hard resin member and the soft resin member was evaluated based on the peel strength.

Examples 1-8 and Comparative Examples 1-2
Cover approximately 1/4 area of a molded body made of polyamide elastomer or polyamide (100 mm square, 2 mm thick flat plate formed by injection molding) with aluminum foil, and this resin member is in a 100 mm square, 4 mm deep flat plate mold The composite molded body was formed by injection-molding thermoplastic polyurethane (TPU) in the voids formed in the mold. TPU injection molding was performed under conditions of a cylinder temperature of 205 ° C and a mold temperature of 60 ° C.

  As the TPU, polyether-based thermoplastic polyurethane C1 (Elastolan ET890, manufactured by BASF) or C2 (Elastolan 1195ATR, manufactured by BASF) was used.

  Moreover, what was prepared in the following procedures was used for the polyamide elastomer or polyamide.

(1) Polyamide elastomer (A1)
Lauryl lactam (500 g) and dodecadioic acid (50 g) were added to the pressure vessel, and the mixture was stirred at 270 ° C. and 20 atm for 3 hours under a nitrogen stream. 500 g of polytetramethylene glycol (molecular weight 1300, terminal is a hydroxyl group) was added to the obtained mixture, and the mixture was stirred while heating under reduced pressure. After 5 hours, a polyamide elastomer (A1) was obtained.

(2) Polyamide elastomer (A2)
Elastomer (A2) was prepared in the same manner as (A1) except that 800 g of lauryl lactam, 90 g of dodecadioic acid and 320 g of polytetramethylene glycol were used.

(3) Polyamide elastomer (A3)
Elastomer (A3) was prepared in the same manner as (A1) except that 300 g of lauryl lactam, 30 g of dodecadioic acid and 450 g of polytetramethylene glycol were used.

(4) Polyamide elastomer (A4)
Elastomer (A4) was prepared in the same manner as (A1) except that 500 g of lauryl lactam and 25 g of dodecadioic acid were used, and 500 g of polypropylene glycol (molecular weight 1000, terminal is a hydroxyl group) was used instead of polytetramethylene glycol.

(5) Polyamide elastomer (A5)
An elastomer (A5) was prepared in the same manner as (A4) except that 500 g of polyethylene glycol (molecular weight 2000, terminal is a hydroxyl group) was used instead of polypropylene glycol.

(6) Polyamide (B1)
Heat 1000g of lauryl lactam and 110g of dodecadioic acid to 250-260 ° C in a nitrogen-substituted autoclave in the presence of a small amount of phosphoric acid, and discharge the water in the system together with nitrogen gas over 4 hours. did. Thereafter, the temperature was gradually raised to 275 ° C. over 1 hour, and the remaining water was removed from the system, followed by cooling to obtain a comparative polyamide (B1).

  Table 1 shows the peel strengths of the composite molded bodies of Examples and Comparative Examples.

Claims (8)

  A composite molded body in which a resin member composed of a polyamide-based resin and a resin member composed of a thermoplastic polyurethane-based resin are directly bonded, wherein the polyamide-based resin and the thermoplastic polyurethane-based resin are each a polyether segment A composite molded body having The composite molded body according to claim 1, wherein the polyamide-based resin is composed of a polyamide elastomer having a polyoxy C _2-4 alkylene segment as a soft segment. The composite molded article according to claim 1, wherein the thermoplastic polyurethane-based resin is composed of a thermoplastic polyether urethane elastomer having a polyoxy C _2-4 alkylene segment as a soft segment.   The polyamide-based resin is composed of a polyamide elastomer including a polyamide segment and a polyether segment, and the ratio (weight ratio) of the polyamide segment to the polyether segment is the former / the latter = 9 / 1-2. The composite molded article according to claim 1, which is 5 / 7.5.   2. The composite molded body according to claim 1, wherein the proportion of the polyether segment in the polyamide resin constituting the resin member and the thermoplastic polyurethane resin constituting the resin member is 10 to 90 wt% with respect to the whole resin.   The composite molded body according to claim 1, which is a constituent member of a shoe or a roll.   The method for producing a composite molded article according to claim 1, wherein at least one of the polyamide-based resin and the thermoplastic polyurethane-based resin according to claim 1 is heated and bonded to the other.   The manufacturing method according to claim 7, wherein the polyamide-based resin and the thermoplastic polyurethane-based resin are joined in the molding process by a molding method selected from thermoforming, injection molding, extrusion molding, and blow molding.