JP2021091860A - Resin composition, molding and method for producing the same - Google Patents

Abstract

To provide a resin composition that makes it possible to obtain a molding having rigidity and toughness in a balanced manner.SOLUTION: A resin composition contains at least polyamide (A) and modified cyclodextrin (B). The resin composition has a sea-island structure in which a sea phase is predominantly composed of the polyamide (A) and an island phase is predominantly composed of the modified cyclodextrin (B), with the island phase having an average diameter of 1 μm or less.SELECTED DRAWING: None

Description

The present invention relates to a polyamide resin composition obtained by blending polyamide and modified cyclodextrin and having an excellent balance of rigidity and toughness, a molded product obtained by molding the same, and a method for producing the same. It is a thing.

Polyamide resins have properties suitable for engineering plastics, such as excellent mechanical and thermal properties such as rigidity and toughness. Therefore, mainly for injection molding applications, various electrical and electronic parts, mechanical parts and Widely used in applications such as automobile parts.

As a method for further improving the toughness of a polyamide resin, it is known to blend an olefin elastomer or a core-shell type compound in which a rubber-like core layer is covered with a glass-like resin shell layer. Examples of the technique for blending an olefin-based elastomer include a continuous phase made of a polyamide resin and a particulate dispersed phase made of a polyolefin modified with α, β-unsaturated carboxylic acid dispersed in the continuous phase. A polyamide-based resin composition (see, for example, Patent Document 1) has been proposed. As a technique for blending a core-shell type compound, for example, a multilayer structure having a polyalkyl (meth) acrylate as a core and a first layer made of polyorganosiloxane and a second layer made of polyalkyl (meth) acrylate on the core. A composite rubber-based graft copolymer obtained by graft-polymerizing a vinyl-based monomer to the coalesced particles, an impact-resistant thermoplastic resin composition composed of a thermoplastic resin (see, for example, Patent Document 2), and a terephthalic acid unit. Polyamide resin composition consisting of a dicarboxylic acid unit contained, a polyamide resin composed of 1,9-nonanediamine units and / or a diamine unit containing 2-methyl-1,8-octanediamine units, and resin fine particles having a core-shell structure. A thing (see, for example, Patent Document 3) has been proposed.

On the other hand, as a method for improving impact strength and toughness, for example, a resin composition obtained by reacting a polyolefin modified with an unsaturated carboxylic acid anhydride with a polyrotaxane having a functional group (see, for example, Patent Document 4). , A polylactic acid-based resin composition containing a polyrotaxane in which an opening of a cyclic molecule having a graft chain made of polylactic acid is encapsulated by a linear molecule and a polylactic acid resin (see, for example, Patent Document 5) has been proposed. ing. Further, in the resin composition described in Patent Document 6, a method of greatly improving the toughness of the polyamide by adding polyrotaxane has been proposed.

Japanese Unexamined Patent Publication No. 9-31325 Japanese Unexamined Patent Publication No. 5-339462 Japanese Unexamined Patent Publication No. 2000-186204 Japanese Unexamined Patent Publication No. 2013-209460 Japanese Unexamined Patent Publication No. 2014-84414 International Publication No. 2016/16427

However, although the conventional resin composition disclosed in Patent Document 6 has an excellent balance between toughness and rigidity, further improvement in toughness is required, and the cost of synthesizing polyrotaxane as a raw material is high. There was a problem.

An object of the present invention is to provide a resin composition which is inexpensive and can obtain a molded product having an excellent balance of rigidity and toughness in view of the above-mentioned problems of the background technology.

In order to solve the above problems, the present invention has the following configurations.
(1) A resin composition containing at least polyamide (A) and modified cyclodextrin (B), mainly containing the sea phase containing the polyamide (A) as a main component and the modified cyclodextrin (B). A resin composition having a sea-island structure composed of island phases as components, wherein the average diameter of the island phases is 1 μm or less.
(2) The resin composition according to item (1), wherein the resin composition is further blended with an epoxy resin (C).
(3) The resin composition according to item (1) or (2), wherein the 5% weight loss temperature measured by thermogravimetric analysis of the modified cyclodextrin (B) is 300 ° C. or higher.
(4) The resin composition according to (2) or (3), wherein the epoxy resin (C) is a bisphenol A type epoxy resin and / or a bisphenol F type epoxy resin.
(5) The resin composition according to any one of (1) to (4), wherein the modified cyclodextrin (B) is modified with an aliphatic polyester.
(6) The resin composition according to any one of (1) to (5), wherein the modified cyclodextrin (B) is a modified cyclodextrin obtained by modifying β-cyclodextrin or γ-cyclodextrin. Stuff.
(7) A molded product obtained by blending the resin composition according to any one of (1) to (6).
(8) The method for producing a resin composition according to any one of (1) to (7), which is produced by melt-kneading at least polyamide (A) and modified cyclodextrin (B).

The resin composition of the present invention provides a molded product having an excellent balance between rigidity and toughness.

Hereinafter, the present invention will be described in more detail.

The resin composition of the present invention comprises at least polyamide (A) and modified cyclodextrin (B). By blending the polyamide (A), the rigidity and heat resistance can be improved. In addition, toughness can be improved by blending modified cyclodextrin (B). The resin composition of the present invention contains, in addition to the polyamide (A) component and the modified cyclodextrin (B) component, a product obtained by reacting the (A) component and the (B) component. It is not practical to identify the structure of. Therefore, the present invention specifies the invention by each component to be blended.

The polyamide (A) in the resin composition of the present invention contains amino acid, lactam or diamine and dicarboxylic acid residues as main constituents. Typical examples of the raw materials are amino acids such as 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid and paraaminomethylbenzoic acid, lactam such as ε-caprolactam and ω-laurolactam, tetramethylenediamine and penta. Methylenediamine, hexamethylenediamine, 2-methylpentamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4- / 2,4,4-trimethylhexamethylenediamine, 5 − An aliphatic diamine such as methylnonamethylenediamine, an aromatic diamine such as metaxylylenediamine and paraxylylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1- Amino-3-aminomethyl-3,5,5-trimethylcyclohexane, bis (4-aminocyclohexyl) methane, bis (3-methyl-4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane , Bis (aminopropyl) piperazine, alicyclic diamines such as aminoethyl piperazine, aliphatic dicarboxylic acids such as adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, terephthalic acid, isophthalic acid, 2-chloroterephthalic acid Aromatic dicarboxylic acids such as acids, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodiumsulfoisophthalic acid, 2,6-naphthalenedicarboxylic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, 1,4-cyclohexane Examples thereof include alicyclic dicarboxylic acids such as dicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid and 1,3-cyclopentanedicarboxylic acid. In the present invention, two or more kinds of polyamide homopolymers or copolymers derived from these raw materials may be blended.

Specific examples of the polyamide (A) include polycaproamide (nylon 6), polyhexamethylene adipamide (nylon 66), polytetramethylene adipamide (nylon 46), and polytetramethylene sebacamide (nylon). 410), Polypentamethylene adipamide (Nylon 56), Polypentamethylene sebacamide (Nylon 510), Polyhexamethylene sebacamide (Nylon 610), Polyhexamethylene dodecamide (Nylon 612), Polydecamethylene Aji Pamide (Nylon 106), Polydecamethylene sebacamide (Nylon 1010), Polydecamethylene dodecamide (Nylon 1012), Polyundecaneamide (Nylon 11), Polydodecaneamide (Nylon 12), Polycaproamide / Polyhexa Methylene adipamide copolymer (nylon 6/66), polycaproamide / polyhexamethylene terephthalamide copolymer (nylon 6 / 6T), polyhexamethylene adipamide / polyhexamethylene terephthalamide copolymer (nylon 66 / 6T), poly Hexamethylene adipamide / polyhexamethylene isophthalamide copolymer (nylon 66 / 6I), polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (nylon 6T / 6I), polyhexamethylene terephthalamide / polydodecaneamide copolymer (nylon) 6T / 12), polyhexamethylene adipamide / polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (nylon 66 / 6T / 6I), polyxylylene adipamide (nylon XD6), polyxylylene sebacamide (Nylon XD10), Polyhexamethylene terephthalamide / Polypentamethylene terephthalamide copolymer (Nylon 6T / 5T), Polyhexamethylene terephthalamide / Poly-2-methylpentamethylene terephthalamide copolymer (Nylon 6T / M5T), Polypentamethylene Telephthalamide / polydecamethylene terephthalamide copolymer (nylon 5T / 10T), polynonamethylene terephthalamide (nylon 9T), polydecamethylene terephthalamide (nylon 10T), polydodecamethylene terephthalamide (nylon 12T) and their co-weights Examples include coalescence. Two or more of these may be blended. Here, "/" indicates a copolymer, and the same applies hereinafter.

In the resin composition of the present invention, the melting point of the polyamide (A) is preferably 150 ° C. or higher and 300 ° C. or lower. When the melting point is 150 ° C. or higher, the heat resistance can be improved. On the other hand, when the melting point is 300 ° C. or lower, the thermal decomposition of the modified cyclodextrin (B) can be suppressed.

Here, the melting point of the polyamide (A) in the present invention is determined by lowering the temperature of the polyamide (A) from the molten state to 30 ° C. at a temperature lowering rate of 20 ° C./min under an inert gas atmosphere using a differential scanning calorimeter. It is defined as the temperature of the endothermic peak that appears when the temperature is raised to the melting point + 40 ° C. at a heating rate of 20 ° C./min. However, when two or more endothermic peaks are detected, the temperature of the endothermic peak having the highest peak intensity is set as the melting point.

Specific examples of polyamide having a melting point of 150 ° C. or higher and 300 ° C. or lower include polycaproamide (nylon 6), polyhexamethylene adipamide (nylon 66), polypentamethylene adipamide (nylon 56), and poly. Tetramethylene adipamide (nylon 46), polyhexamethylene sebacamide (nylon 610), polyhexamethylene dodecamide (nylon 612), polyundecaneamide (nylon 11), polydodecaneamide (nylon 12), polycaproamide / Polyhexamethylene adipamide copolymer (nylon 6/66), polycaproamide / polyhexamethylene terephthalamide copolymer (nylon 6 / 6T), polyhexamethylene adipamide / polyhexamethylene isophthalamide copolymer (nylon 66 / 6I) ), Polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (nylon 6T / 6I), polyhexamethylene terephthalamide / polydodecaneamide copolymer (nylon 6T / 12), polyhexamethylene adipamide / polyhexamethylene terephthalamide / Polyhexamethylene isophthalamide copolymer (nylon 66 / 6T / 6I), polyxylylene adipamide (nylon XD6), polyhexamethylene terephthalamide / poly-2-methylpentamethylene terephthalamide copolymer (nylon 6T / M5T), Examples thereof include polymethylene terephthalamide (nylon 9T) and copolymers thereof. Two or more of these may be blended. In particular, in the present invention, by using the modified cyclodextrin (B) described later, a molded product having an excellent balance of rigidity and toughness can be obtained even in a polyamide resin having a high melting point of 250 ° C. to 300 ° C. .. Examples of polyamides having a melting point of 250 ° C. to 300 ° C. include polyhexamethylene adipamide (nylon 66), polypentamethylene adipamide (nylon 56), polytetramethylene adipamide (nylon 46), and polycaproamide. / Polyhexamethylene terephthalamide copolymer (nylon 6 / 6T), polyhexamethylene adipamide / polyhexamethylene isophthalamide copolymer (nylon 66 / 6I), polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (nylon 6T / 6I), polyhexamethylene terephthalamide / polydodecaneamide copolymer (nylon 6T / 12), polyhexamethylene adipamide / polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (nylon 66 / 6T / 6I), polyxili Examples thereof include lenazipamide (nylon XD6), polyhexamethylene terephthalamide / poly-2-methylpentamethylene terephthalamide copolymer (nylon 6T / M5T), and polymethylene terephthalamide (nylon 9T).

The degree of polymerization of the polyamide (A) is not particularly limited, but the relative viscosity measured at 25 ° C. in a 98% concentrated sulfuric acid solution having a resin concentration of 0.01 g / mL is in the range of 1.5 to 5.0. preferable. When the relative viscosity is 1.5 or more, the toughness, rigidity, wear resistance, fatigue resistance, and creep resistance of the obtained molded product can be further improved. 2.0 or more is more preferable. On the other hand, when the relative viscosity is 5.0 or less, the fluidity is excellent and the molding processability is excellent.

In the resin composition of the present invention, the polyamide (A) is preferably non-biodegradable. Since the polyamide (A) is non-biodegradable, durability can be improved.

The blending amount of the polyamide (A) in the resin composition of the present invention is 80 parts by weight or more and 99.9 parts by weight or less with respect to 100 parts by weight in total of the polyamide (A) and the modified cyclodextrin (B). preferable. By setting the blending amount of the polyamide (A) to 80 parts by weight or more, it is possible to maintain the rigidity and heat resistance of the obtained molded product. When the blending amount of the polyamide (A) is 99.9 parts by weight or less, the relative blending amount of the modified cyclodextrin (B) is increased, so that the toughness of the molded product is improved. The blending amount of the polyamide (A) is preferably 99.5 parts by weight or less.

The resin composition of the present invention comprises a modified cyclodextrin (B).

The modified cyclodextrin is a compound represented by the following general formula (a), and is a compound in which glucose constituting cyclodextrin is modified with a functional group R.

(N is an integer of 6 to 8, R is a hydroxyl group, at least one hydroxypropoxy group, a methoxy group, an alkoxy group having 2 or more carbon atoms, a polyalkylene glycolix group, an aliphatic polyester, and a polyalkylene glycol via a hydroxypropoxy group. , A functional group selected from aliphatic polyesters via a hydroxypropoxy group. R may be the same or different from each other, except when all R are hydroxyl groups).

The modified cyclodextrin (B) is obtained by chemically modifying and converting the hydroxyl group of glucose, which is the basic skeleton constituting cyclodextrin. Examples of cyclodextrins include α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin. Of these, β-cyclodextrin and γ-cyclodextrin are more preferably used. By using these preferable cyclodextrins, the toughness of the obtained molded product is improved.

Specific examples of the modifying group that chemically modifies and converts the hydroxyl group of cyclodextrin include an alkoxy group having 2 or more carbon atoms such as a methoxy group, an ethoxy group, and a propoxy group, and a modified cyclodextrin modified with a hydroxypropoxy group. Examples thereof include modified cyclodextrin in which cyclodextrin and polyalkylene glycol or aliphatic polyester are bonded without a binding group, modified cyclodextrin in which cyclodextrin and polyalkylene glycol or aliphatic polyester are bonded via a bonding group, and the like. .. Examples of aliphatic polyesters are polylactic acid, polyglycolic acid, poly 3-hydroxybutyrate, poly 4-hydroxybutyrate, poly (3-hydroxybutyrate / 3-hydroxyvalerate), poly (ε-caprolactone). And so on. Two or more of these may be combined. Among these, from the viewpoint of developing the toughness of the obtained molded product, those obtained by modifying both a hydroxypropoxy group, a methoxy group, or a hydroxypropoxy group and poly (ε-caprolactone) are preferable, and a hydroxypropoxy group and poly (ε-) are preferable. Cyclodextrin modified with both caprolactone) is particularly preferably used.

Further, when an aliphatic polyester is used as a modifying group of the modified cyclodextrin (B), the weight ratio of the aliphatic polyester to the cyclodextrin (aliphatic polyester / cyclodextrin) is preferably in the range of 0.5 or more and 300 or less. It is more preferably in the range of 1 or more and 150 or less, and further preferably in the range of 5 or more and 100 or less. When the weight ratio of the aliphatic polyester to cyclodextrin is in these preferable ranges, the toughness improving effect, which is the effect of the present invention, tends to be enhanced. In addition, among these preferable ranges, the higher the weight ratio of the aliphatic polyester to cyclodextrin, the higher the 5% weight loss temperature measured by thermogravimetric analysis of the modified cyclodextrin (B), and further, the toughness of the resin composition. Since the improving effect tends to be high, it can be exemplified as a preferable form.

The preferred mode of the modified cyclodextrin (B) in the resin composition of the present invention is that the 5% weight loss temperature measured by thermogravimetric analysis is preferably 300 ° C. or higher. When the 5% weight loss temperature measured by thermogravimetric analysis of the modified cyclodextrin (B) is 300 ° C. or higher, thermal decomposition during the production and molding of the resin composition is suppressed, and a stress relaxation effect can be obtained. it can. Here, in the "5% weight loss temperature measured by thermogravimetric analysis" in the present invention, the modified cyclodextrin (B) is subjected to a thermogravimetric analysis at a rate of 40 ° C. to 10 ° C./min under an inert gas atmosphere. The temperature at which the weight of the modified cyclodextrin (B) is reduced by 5% with respect to the weight before heating when the temperature is raised to 350 ° C. is defined as the 5% weight loss temperature. As a method for controlling the 5% weight loss temperature measured by thermogravimetric analysis of the modified cyclodextrin (B) within the above range, acid addition can be mentioned. The addition of an acid can inactivate the polymerization catalyst used in preparing the modified cyclodextrin. The acid may be either an organic acid or an inorganic acid, but an inorganic acid such as hydrochloric acid, sulfuric acid or phosphoric acid is preferably used, and more preferably phosphoric acid is used. By using these preferable acids, the polymerization catalyst is inactivated and the transesterification reaction by the polymerization catalyst is suppressed, so that the thermal stability of the modified cyclodextrin (B) is improved. Examples of the acid addition method include a method of directly adding / mixing to the modified cyclodextrin (B), a method of adding / mixing the modified cyclodextrin (B) to a dissolved solution, and a method of adding / mixing the modified cyclodextrin (B) to an acidic liquid. Examples thereof include a method of impregnating the inside, but from the viewpoint of processability, it is particularly preferable to directly add to the modified cyclodextrin (B) after synthesis and stir. Moreover, these acids may be used as they are, or may be used as a solution diluted with a solvent.

The blending amount of the modified cyclodextrin (B) in the resin composition of the present invention is 0.1 part by weight or more and 20 parts by weight or less with respect to 100 parts by weight of the total of the polyamide (A) and the modified cyclodextrin (B). is there. If the blending amount of the modified cyclodextrin (B) is less than 0.1 parts by weight, the stress relaxation effect of the modified cyclodextrin (B) is not sufficiently exerted, and the toughness of the molded product is lowered. The blending amount of the modified cyclodextrin (B) is preferably 0.5 parts by weight or more. On the other hand, when the blending amount of the modified cyclodextrin (B) exceeds 20 parts by weight, the blending amount of the polyamide (A) is relatively small, so that the rigidity and heat resistance of the obtained molded product are lowered. The blending amount of the modified cyclodextrin (B) is preferably 10 parts by weight or less, more preferably 7 parts by weight or less. When the blending amount of the modified cyclodextrin is in these preferable ranges, a resin composition and a molded product having an excellent balance between rigidity and toughness can be obtained.

It can be exemplified as a preferable mode that the resin composition of the present invention is prepared by blending an epoxy resin (C) in addition to the polyamide (A) and the modified cyclodextrin (B).

The epoxy resin (C) here includes bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, halogenated bisphenol A type epoxy resin, bisphenol S type epoxy resin, resorcinol type epoxy resin, and hydrogenation. Examples thereof include bisphenol A type epoxy resin, aliphatic epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, naphthalene type epoxy resin, biphenyl type epoxy resin, biphenyl aralkyl type epoxy resin, and dicyclopentadiene type epoxy resin. Among these epoxy resins, bisphenol A type epoxy resin and bisphenol F type epoxy resin, which have an excellent balance between viscosity and heat resistance and excellent affinity with polyamide (A), are preferable.

The number average molecular weight of the epoxy resin (C) is preferably 500 to 100,000. It is more preferably 1,000 to 80,000, and even more preferably 1,500 to 50,000. When the number average molecular weight is 500 or more, the heat resistance is excellent, and when the number average molecular weight is 100,000 or less, the affinity and reactivity with the polyamide (A) is excellent. The number average molecular weight of the epoxy resin (C) can be measured by gel permeation chromatography (GPC).

The blending amount of the epoxy resin (C) in the resin composition of the present invention is 0.1 part by weight or more with respect to 100 parts by weight in total of the polyamide (A), the modified cyclodextrin (B), and the epoxy resin (C). It is preferably 20 parts by weight or less, and more preferably 0.5 parts by weight or more and 10 parts by weight or less. When the blending amount of the epoxy resin (C) is in these preferable ranges, a resin composition and a molded product having an excellent balance between rigidity and toughness can be obtained.

The resin composition of the present invention has a sea-island structure having a sea phase containing polyamide (A) as a main component and an island phase containing modified cyclodextrin (B) as a main component, and the average diameter of the island phases is 1 μm or less. It is characterized by being. Here, the "main component" refers to a component that accounts for 80% by weight or more in the phase. It is known that the properties of the resin composition are also affected by the phase-separated structure and its phase size. A resin composition composed of two or more kinds of components and having a phase-separated structure brings out the advantages of each component and complements the disadvantages to exhibit excellent properties as compared with the case of each component alone. In the sea-island structure of the resin composition of the present invention, the average diameter of the island phases is preferably 0.01 μm or more. When the average diameter of the island phase is 0.01 μm or more, the characteristics derived from the phase-separated structure can be exhibited more effectively, and the toughness can be further improved. The average diameter of the island phase is 1 μm or less, more preferably 0.8 μm or less, still more preferably 0.5 μm or less. When the average diameter of the island phase is 1 μm or less, the stress relaxation effect of the modified cyclodextrin can be efficiently spread over the entire polyamide (A), and by reducing the phase of the flexible modified cyclodextrin, the phase can be reduced. It is possible to suppress a decrease in rigidity.

The average diameter of the island fauna of the sea-island structure in the resin composition of the present invention can be determined by the following method by observing with an electron microscope. Since the phase-separated structure of the resin composition and the size of each phase do not change under general molding conditions, in the present invention, the phase-separated structure is observed using a test piece obtained by molding the resin composition. To do. First, the central part of the ISO527-2-5A dumbbell test piece obtained by injection molding in the cross-sectional direction is cut into a square of 1 to 2 mm, and the polyamide (A) is dyed with phosphotungstate / osmium, and then 0.1 μm or less (about 0.1 μm). An ultrathin section (80 nm) is cut with an ultramicrotome at -196 ° C. to obtain a sample for a transmission electron microscope. When determining the average diameter of the island fauna of the sea-island structure, the magnification of the above-mentioned transmission electron microscope sample is adjusted so that 50 or more and less than 100 island fauna are present in the square electron microscope observation photograph. At such a magnification, 50 island phases are randomly selected from the island phases existing in the observation image, and the major axis and the minor axis are measured for each island phase. The average value of the major axis and the minor axis is taken as the diameter of each island fauna, and the average value of the diameters of all the measured island fauna is taken as the average diameter of the island fauna. The major axis and the minor axis of the island fauna refer to the longest diameter and the shortest diameter of each island fauna.

The sea-island structure in which the average diameter of the island phase is in the above-mentioned preferable range can be obtained, for example, by setting the blending amounts of the polyamide (A) and the modified cyclodextrin (B) in the above-mentioned preferable range. The smaller the amount of modified cyclodextrin (B), the smaller the average diameter of the island phase, and the larger the amount of modified cyclodextrin (B), the larger the average diameter of the island phase. Further, the resin composition in the present invention may contain an epoxy resin (C). By blending the epoxy resin (C), the average diameter of the island phase tends to be further reduced, which is preferable.

In the resin composition of the present invention, a filler, a thermoplastic resin other than polyamide, various additives and the like can be further blended as long as the object of the present invention is not impaired.

By blending the filler, the strength and rigidity of the obtained molded product can be further improved. The filler may be either an organic filler or an inorganic filler, and may be a fibrous filler or a non-fibrous filler. Two or more of these may be blended.

Examples of the fibrous filler include glass fiber and carbon fiber. These may be coated or focused with a thermoplastic resin such as ethylene / vinyl acetate or a thermosetting resin such as an epoxy resin. Examples of the broken shape of the fibrous filler include a circular shape, a flat shape, an eyebrows shape, an oval shape, an elliptical shape, and a rectangular shape. Further, in addition to these fillers, a surface modifier such as a silane coupling agent may be used in combination.

Examples of the non-fibrous filler include non-expandable silicates such as talc, wallastenite, zeolite, sericite, mica, kaolin, clay, pyrophyllite, bentonite, asbestos, alumina silicate, and calcium silicate, and Li-type fluorine. Swellable layered silicates such as teniolite, Na-type fluorine teniolite, Na-type tetrasilicon fluorine mica, and swellable mica of Li-type tetrasilicon fluorine mica, silicon oxide, magnesium oxide, alumina, silica, diatomaceous soil, zirconium oxide, titanium oxide, Metal oxides such as iron oxide, zinc oxide, calcium oxide, tin oxide, antimony oxide, metal carbonates such as calcium carbonate, magnesium carbonate, zinc carbonate, barium carbonate, dolomite, hydrotalcite, calcium sulfate, barium sulfate, etc. Metal hydroxides such as metal sulfate, magnesium hydroxide, calcium hydroxide, aluminum hydroxide, basic magnesium carbonate, smectite clay minerals such as montmorillonite, biderite, nontronite, saponite, hectolite, and soconite, and vermiculite, Various clay minerals such as halloysite, kanemite, keniyaite, zirconium phosphate, titanium phosphate, glass beads, glass flakes, ceramic beads, boron nitride, aluminum nitride, silicon carbide, calcium phosphate, carbon black, graphite and the like can be mentioned. In the above-mentioned swellable layered silicate, exchangeable cations existing between layers may be exchanged with organic onium ions. Examples of the organic onium ion include ammonium ion, phosphonium ion, sulfonium ion and the like.

Specific examples of resins other than polyamide include polyester resin, polyolefin resin, modified polyphenylene ether resin, polysulfone resin, polyketone resin, polyetherimide resin, polyarylate resin, polyether sulfone resin, polyether ketone resin, and polythioether ketone. Examples thereof include resins, polyether ether ketone resins, polyimide resins, polyamideimide resins, and tetrafluoride polyethylene resins. Two or more of these may be blended.

Specific examples of various additives include heat stabilizers typified by copper compounds, isocyanate compounds, organic silane compounds, organic titanate compounds, organic borane compounds, coupling agents such as epoxy compounds, and polyalkylene oxide oligomers. Plastic compounds such as system compounds, thioether compounds, ester compounds, organic phosphorus compounds, crystal nucleating agents such as organic phosphorus compounds, polyether ether ketones, waxes montanate, lithium stearate, metals such as aluminum stearate. Soap, ethylenediamine / stearic acid / sebacic acid polycondensate, mold release agent such as silicone compound, anticolorant such as hypophosphate, lubricant, UV inhibitor, colorant, flame retardant, foaming agent, etc. be able to. When these additives are blended, the blending amount thereof is preferably 10 parts by weight or less, more preferably 1 part by weight or less, based on 100 parts by weight of the polyamide (A) in order to fully utilize the characteristics of the polyamide.

Examples of heat stabilizers for copper compounds include copper chloride, copper bromide, copper iodide, copper acetate, copper acetylacetonate, copper carbonate, copper borofluoride, copper citrate, copper hydroxide, copper nitrate, and copper sulfate. Examples include copper oxalate. Two or more kinds of these may be contained as a copper compound. Among these copper compounds, copper halide, which is industrially easily available, is preferable. Examples of copper halide include copper iodide, cuprous bromide, cupric bromide, and cupric chloride. Of these, copper iodide can be particularly preferably exemplified.

Examples of heat stabilizers other than copper compounds include N, N'-hexamethylenebis (3,5-di-t-butyl-4-hydroxy-hydrocinnamide) and tetrakis [methylene-3- (3', 5'-di). -T-butyl-4'-hydroxyphenyl) propionate] Phenolic compounds such as methane, phosphorus compounds, mercaptobenzoimidazole compounds, dithiocarbamic acid compounds, sulfur compounds such as organic thioic acid compounds, N, N' Examples thereof include amine compounds such as −di-2-naphthyl-p-phenylenediamine and 4,4′-bis (α, α-dimethylbenzyl) diphenylamine. Two or more of these may be blended.

The resin composition of the present invention is produced by melt-kneading at least polyamide (A), modified cyclodextrin (B), and if necessary, epoxy resin (C), and various additives. Examples of the melt-kneading device include a multi-screw extruder such as a single-screw extruder, a twin-screw extruder, and a four-screw extruder, an extruder such as a twin-screw single-screw compound extruder, and a kneader. From the viewpoint of productivity, an extruder capable of continuously producing is preferable, and from the viewpoint of improving kneadability and productivity, a twin-screw extruder is more preferable.

Hereinafter, a case where the resin composition of the present invention is produced using a twin-screw extruder will be described as an example. The maximum resin temperature is preferably 350 ° C. or lower from the viewpoint of suppressing thermal deterioration of the modified cyclodextrin (B) and further improving the toughness. On the other hand, the maximum resin temperature is preferably equal to or higher than the melting point of the polyamide (A). Here, the maximum resin temperature refers to the highest temperature measured by resin thermometers evenly installed at a plurality of locations of the extruder.

The resin composition thus obtained can be molded by a commonly known method, and various molded products such as sheets and films can be obtained. Examples of the molding method include injection molding, injection compression molding, extrusion molding, compression molding, blow molding, press molding and the like.

The resin composition of the present invention and its molded product can be used for various purposes such as automobile parts, electric / electronic parts, building materials, various containers, daily necessities, household goods and sanitary goods by utilizing its excellent properties. In particular, it is particularly preferably used for automobile exterior parts that require toughness and rigidity, automobile electrical components, automobile underhood parts, automobile gear parts, housings, connectors, reflectors, and other electric and electronic parts. Specifically, automobile engine peripheral parts such as engine cover, air intake pipe, timing belt cover, intake manifold, filler cap, throttle body, cooling fan, cooling fan, radiator tank top and base, cylinder head cover, oil pan, etc. Automotive underhood parts such as brake pipes, fuel piping tubes, exhaust system parts, automobile gear parts such as gears, actuator bearing retainers, bearing cages, chain guides, chain tensioners, shift lever brackets, steering lock brackets, key cylinders, doors. Inner handle, door handle cowl, interior mirror bracket, air conditioner switch, instrument panel, console box, glove box, steering wheel, trim and other automobile interior parts, front fender, rear fender, fuel lid, door panel, cylinder head cover, door mirror stay, Auto exterior parts such as tailgate panels, licensed garnishes, roof rails, engine mount brackets, rear garnishes, rear spoilers, trunk lids, rocker moldings, moldings, lamp housings, front grilles, mudguards, side bumpers, crash boxes, air intake manifolds, Intake and exhaust system parts such as intercooler inlet, exhaust pipe cover, inner bush, bearing retainer, engine mount, engine head cover, resonator, and throttle body, chain cover, thermostat housing, outlet pipe, radiator tank, oil nator, and delivery pipe, etc. Engine cooling water system parts, connectors and wire harness connectors, motor parts, lamp sockets, sensor in-vehicle switches, combination switches and other automobile electrical parts, SMT compatible connectors, sockets, card connectors, jacks, power supply parts, switches, sensors, capacitors Electrical and electronic components such as seat plates, relays, resistors, fuse holders, coil bobbins, IC and LED compatible housings, and reflectors can be preferably mentioned.

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples. The following raw materials were used to obtain the resin compositions of each example.

<Polyamide>
(A-1): Polyamide 6 resin (“Amylan” (registered trademark) manufactured by Toray Industries, Inc.), ηr = 2.70, melting point 225 ° C.
(A-2): Polyamide 66 resin (“Amylan” (registered trademark) manufactured by Toray Industries, Inc.), ηr = 2.78, melting point 260 ° C.

Here, the relative viscosity ηr was measured in a 0.01 g / mL solution of 98% concentrated sulfuric acid at 25 ° C. The melting point is determined by lowering the temperature of the polyamide from the molten state to 30 ° C. at a temperature lowering rate of 20 ° C./min under an inert gas atmosphere using a differential scanning calorimeter, and then melting the polyamide at a heating rate of 20 ° C./min. It was defined as the temperature of the endothermic peak that appears when the temperature is raised to + 40 ° C. However, when two or more endothermic peaks are detected, the temperature of the endothermic peak having the highest peak intensity is taken as the melting point.

<Denatured cyclodextrin>
(B-1): Prepared by modifying / recovering hydroxypropylated α-cyclodextrin (manufactured by Sigma-Aldrich) with polycaprolactone by the method described in Reference Example 1. The 5% weight loss temperature was 313.2 ° C. The weight ratio (PCL / CD) of polycaprolactone in the prepared modified cyclodextrin was 9.8.
(B-2): Prepared by modifying / recovering hydroxypropylated β-cyclodextrin (manufactured by Sigma-Aldrich) with polycaprolactone by the method described in Reference Example 2. The 5% weight loss temperature was 314.6 ° C. The weight ratio (PCL / CD) of polycaprolactone in the prepared modified cyclodextrin was 8.6.
(B-3): Prepared by modifying / recovering hydroxypropylated β-cyclodextrin (manufactured by Sigma-Aldrich) with polycaprolactone by the method described in Reference Example 3. The 5% weight loss temperature was 336.2 ° C. The weight ratio (PCL / CD) of polycaprolactone in the prepared modified cyclodextrin was 25.9.
(B-4): Prepared by modifying / recovering hydroxypropylated β-cyclodextrin (manufactured by Sigma-Aldrich) with polycaprolactone by the method described in Reference Example 4. The 5% weight loss temperature was 339.5 ° C. The weight ratio (PCL / CD) of polycaprolactone in the prepared modified cyclodextrin was 43.8.
(B-5): Prepared by modifying / recovering hydroxypropylated β-cyclodextrin (manufactured by Sigma-Aldrich) with polycaprolactone by the method described in Reference Example 5. The 5% weight loss temperature was 264.6 ° C. The weight ratio (PCL / CD) of polycaprolactone in the prepared modified cyclodextrin was 8.7.
(B-6): Prepared by modifying / recovering hydroxypropylated β-cyclodextrin (manufactured by Sigma-Aldrich) with polycaprolactone by the method described in Reference Example 6. The 5% weight loss temperature was 264.8 ° C. The weight ratio (PCL / CD) of polycaprolactone in the prepared modified cyclodextrin was 8.6.

<Epoxy resin>
(C-1): Bisphenol A type epoxy resin manufactured by Mitsubishi Chemical Corporation jER1007 (number average molecular weight: 2,900)
(C-2): Bisphenol A type epoxy resin manufactured by Mitsubishi Chemical Corporation jER1256 (number average molecular weight: 45,000)

<Other ingredients>
(D-1): Prepared by adding and recovering acid to polyrotaxane (“CELM” (registered trademark) Superpolymer SH2400P manufactured by ASM Co., Ltd.) by the method described in Reference Example 7. The 5% weight loss temperature was 288.9 ° C. The 5% weight loss temperature of the polyrotaxane used in Reference Example 7 was 262.3 ° C.
(D-2): α-Cyclodextrin (manufactured by Junsei Chemical Co., Ltd.)
(D-3): β-Cyclodextrin (manufactured by Junsei Chemical Co., Ltd.)

(Reference example 1)
3 g of hydroxypropylated α-cyclodextrin and 30.9 g of ε-caprolactone were placed in a three-necked flask, and nitrogen was flowed into the flask. After stirring the reaction solution in an oil bath at 110 ° C. for 1 hour, the temperature of the oil bath was raised to 130 ° C., and a solution prepared by dissolving 0.18 g of tin (II) octylate in 1.5 g of toluene was added dropwise to the reaction solution. .. After heating and stirring in an oil bath at 130 ° C. for 6 hours, heating was stopped, 45 mL of toluene was added to dissolve the reaction product, and the reaction product was poured into 600 mL of hexane for reprecipitation. The obtained reaction product was recovered and vacuum dried at 80 ° C. for 10 hours.

(Reference example 2)
Stir 9.0 g of hydroxypropylated β-cyclodextrin to 81.6 g of ε-caprolactone at each temperature for 30 minutes while gradually raising the temperature from 110 ° C to 130 ° C to 150 ° C in an oil bath under a nitrogen flow. It was dissolved by doing. After cooling the oil bath to 130 ° C., a catalyst solution obtained by diluting 0.5 g of tin (II) octylate with 1.6 g of toluene was added dropwise to this mixed solution, and the mixture was stirred at 130 ° C. for 4 hours. A solution obtained by diluting 0.2 g of phosphoric acid with 1.3 g of tetrahydrofuran is added to the obtained reaction product, and the mixture is stirred at 130 ° C. for 20 minutes, recovered as it is without purification, and vacuum dried at 80 ° C. for 12 hours. Diluted.

(Reference example 3)
Stir 3.0 g of hydroxypropylated β-cyclodextrin to 82.6 g of ε-caprolactone at each temperature for 30 minutes while gradually raising the temperature from 110 ° C to 130 ° C to 150 ° C in an oil bath under a nitrogen flow. It was dissolved by doing. After cooling the oil bath to 130 ° C., a catalyst solution obtained by diluting 0.5 g of tin (II) octylate with 1.6 g of toluene was added dropwise to this mixed solution, and the mixture was stirred at 130 ° C. for 4 hours. A solution obtained by diluting 0.2 g of phosphoric acid with 1.3 g of tetrahydrofuran is added to the obtained reaction product, and the mixture is stirred at 130 ° C. for 20 minutes, recovered as it is without purification, and vacuum dried at 80 ° C. for 12 hours. Diluted.

(Reference example 4)
Stir 2.0 g of hydroxypropylated β-cyclodextrin to 91.2 g of ε-caprolactone at each temperature for 30 minutes while gradually raising the temperature from 110 ° C to 130 ° C to 150 ° C in an oil bath under a nitrogen flow. It was dissolved by doing. After cooling the oil bath to 130 ° C., a catalyst solution obtained by diluting 0.5 g of tin (II) octylate with 1.6 g of toluene was added dropwise to this mixed solution, and the mixture was stirred at 130 ° C. for 6 hours. A solution obtained by diluting 0.2 g of phosphoric acid with 1.3 g of tetrahydrofuran was added to the obtained reaction product, and the mixture was stirred at 130 ° C. for 20 minutes, recovered as it was without purification, and vacuum dried at 80 ° C. for 12 hours. Diluted.

(Reference example 5)
Stir 27.0 g of hydroxypropylated β-cyclodextrin to 247.8 g of ε-caprolactone at each temperature for 30 minutes while gradually increasing the temperature from 110 ° C to 130 ° C to 150 ° C in an oil bath under a nitrogen flow. It was dissolved by doing. After cooling the oil bath to 130 ° C., a catalyst solution obtained by diluting 1.6 g of tin (II) octylate with 4.8 g of toluene was added dropwise to this mixed solution, and the mixture was stirred at 130 ° C. for 4 hours. The obtained reaction product was recovered as it was without purification, and was vacuum dried at 80 ° C. for 12 hours.

(Reference example 6)
The same operation as in Reference Example 2 was carried out except that the obtained reaction product was recovered by dropping it in hexane.

(Reference example 7)
10 g of polyrotaxane (“CELM” (registered trademark) Superpolymer SH2400P manufactured by ASM Co., Ltd.) was dissolved in 20 g of 1 wt% tetrahydrofuran of phosphoric acid, and the mixture was stirred at room temperature for 20 minutes. Polyrotaxane was recovered by dropping this solution into 200 mL of methanol and vacuum dried at 80 ° C. for 12 hours.

<Evaluation method>
The evaluation method in each Example and Comparative Example is described below.

(1) Pyrolysis temperature (5% weight loss temperature)
The modified cyclodextrin and polyrotaxane obtained in each reference example were heated from 40 ° C. to a heating rate of 10 ° C./min under a nitrogen flow using a thermogravimetric meter (TG / DTA7200 manufactured by Hitachi High-Tech Science Co., Ltd.) and weighed. The 5% weight loss temperature was determined by measuring the change.

(2) Analysis of modified cyclodextrin The amount of cyclodextrin component and the amount of polycaprolactone component in the modified cyclodextrin obtained in each reference example were analyzed using a nuclear magnetic resonance apparatus (NMR).
Equipment: JEOL Ltd. AL-400
Deuterated solvent: Deuterated chloroform Number of integrations: 128 times Sample concentration: Measurement sample 50 mg / Deuterated solvent 1 mL

(3) Rigidity, toughness (tensile modulus, tensile yield stress, tensile elongation at break)
Each component was blended and pre-blended, and supplied to a small kneader (MiniLab manufactured by HAAKE) set at a cylinder temperature of 230 ° C. (polyamide 6), 280 ° C. (polyamide 66), and a screw rotation speed of 200 rpm for melt kneading. The extruded gut is pelletized and the obtained pellets are vacuum dried at 80 ° C. for 12 hours, and then the cylinder temperature is 240 ° C. (polyamide 6), 290 ° C. (polyamide 66), and the mold temperature is 80 ° C. A dumbbell type test piece compliant with ISO527-2-5A was produced by injection molding with a set injection molding machine (Minijet manufactured by HAAKE).

This test piece was subjected to a tensile test at a tensile speed of 100 mm / min using a tensile tester Autograph AG-20kNX (manufactured by Shimadzu Corporation) in accordance with ISO527 (2012), and the tensile elastic modulus, tensile yield stress and tensile elongation at break were performed. Asked.

(4) Morphology of phase-separated structure and average diameter of island phase A part of the surface layer was cut out from the central part of a dumbbell-shaped test piece conforming to ISO527-2-5A injection-molded under the above conditions, and a Leica ultramicrotome (EM UC7) was cut out. ) Was used to prepare a sample for cross-section observation of about 2 mm × about 1 mm so that the observation surface was in the direction perpendicular to the longitudinal direction of the flat plate with a diamond knife. The prepared sample is stained with phosphotungstate / osmium so as to have sufficient contrast in morphology, and then observed with a transmission electron microscope (H-7100 manufactured by Hitachi, Ltd.) at an acceleration voltage of 100 kV. The phase structure of the cross section was observed, and the morphology of the phase-separated structure was observed. There is an island phase in which a phase containing one component as a main component is formed in the form of particles, and a sea phase in which the other component is a main component, and a structure in which particles are scattered in the sea phase is a sea island structure. And said.

The average diameter of each island phase was determined by the following method for each sample forming the sea-island structure. The magnification was adjusted appropriately so that 50 or more and less than 100 island phases were present in the square electron microscopic observation photograph. At such a magnification, 50 island phases were randomly selected from the island phases existing in the observation image, and the major axis and the minor axis were measured for each island phase. The average value of the major axis and the minor axis was taken as the diameter of each island fauna, and the average value of the diameters of all the measured island fauna was taken as the average diameter of the island fauna.

(Examples 1 to 11, Comparative Examples 1 to 6)
Table 1 shows the results of evaluation by the above method using the raw materials shown in Tables 1 and 2.

By comparing Example 1 with Comparative Examples 2 and 3, it was found that the average diameter of the island phase in the resin composition was 1 μm or less and the tensile elongation at break was significantly improved by using the modified cyclodextrin.

Comparing the modified cyclodextrins (B-1) to (B-4) with the modified cyclodextrins (B-5) and (B-6), the modified cyclodextrin was treated by inactivating the catalyst with the addition of phosphoric acid. It was found that the thermal decomposition temperature of the water was significantly improved. As a result, the modified cyclodextrin having a 5% weight loss temperature of 300 ° C. or higher measured by thermogravimetric analysis could be used for melt-kneading with the polyamide 66 having a high processing temperature. On the other hand, it was found that even if the polyrotaxane was subjected to the same inactivation treatment, the effect of improving the thermal decomposition temperature was limited.

From the comparison of Examples 1 and 2 and Examples 8 and 3 to 6, it was found that by further adding the epoxy resin, the phase structure became finer and the tensile elongation at break increased. Furthermore, from the comparison of Examples 9 to 11, it was found that the tensile elongation at break was significantly improved by increasing the amount of polycaprolactone in the modified cyclodextrin.

Claims (8)

A resin composition containing at least a polyamide (A) and a modified cyclodextrin (B), wherein the sea phase containing the polyamide (A) as a main component and the modified cyclodextrin (B) as main components. A resin composition having a sea-island structure composed of island phases, wherein the average diameter of the island phases is 1 μm or less. The resin composition according to claim 1, wherein the resin composition is further blended with an epoxy resin (C). The resin composition according to claim 1 or 2, wherein the 5% weight loss temperature measured by thermogravimetric analysis of the modified cyclodextrin (B) is 300 ° C. or higher. The resin composition according to claim 2 or 3, wherein the epoxy resin (C) is a bisphenol A type epoxy resin and / or a bisphenol F type epoxy resin. The resin composition according to any one of claims 1 to 4, wherein the modified cyclodextrin (B) is modified with an aliphatic polyester. The resin composition according to any one of claims 1 to 5, wherein the modified cyclodextrin (B) is a modified cyclodextrin obtained by modifying β-cyclodextrin or γ-cyclodextrin. A molded product obtained by molding the resin composition according to any one of claims 1 to 6. The method for producing a resin composition according to any one of claims 1 to 7, wherein at least polyamide (A) and modified cyclodextrin (B) are melt-kneaded.