Modifier for polyamide resin

Abstract

To provide a polyamide resin modifier that gives a polyamide resin high mechanical strength, high dimensional stability and a good appearance in water absorption.SOLUTION: The present invention discloses a polyamide resin modifier (Y) that contains a block polymer (X) having a polyamide block (am) and a polysiloxane block (b) as constitutional units; a polyamide resin composition (Z) that contains the polyamide resin modifier (Y) and a polyamide resin (C); and a molding obtained by molding the polyamide resin composition (Z).SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a modifier for polyamide resin.

Background Art

[0002] Since polyamide resin is excellent in heat resistance and mechanical strength (mechanical properties), it is used in various applications as an engineering plastic. However, a problem is the decrease in mechanical strength and dimensional change during water absorption. For example, a polyamide resin composition added with carbon nanofibers has been proposed (Patent Document 1, etc.).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when adding a filler such as carbon nanofibers, the appearance of the molded product may be impaired, and it has been desired to solve this problem. An object of the present invention is to provide a modifier for polyamide resin that gives excellent mechanical strength, excellent dimensional stability, and appearance to polyamide resin during water absorption.

Means for Solving the Problems

[0005] As a result of intensive studies to solve the above problems, the present inventors have reached the present invention. That is, the present invention is a modifier (Y) for polyamide resin containing a block polymer (X) having a polyamide block (am) and a polysiloxane block (b) as constituent units. wherein the block polymer (X) is a modifier (Y) for a polyamide resin having a structure in which a polyamide block (am) and a polysiloxane block (b) are bonded via an ester bond It is.

Effects of the Invention

[0006] The modifier (Y) for polyamide resin of the present invention has the following effects. (1) It reduces the water absorption of the molded article of the polyamide resin composition and imparts excellent dimensional stability. (2) It imparts excellent mechanical strength (mechanical properties) to the molded article. (3) It imparts excellent appearance to the molded article.

Embodiments for Carrying Out the Invention

[0007] <Block (am) of polyamide> Examples of the block (am) of polyamide include polyamide (am1) having dicarboxylic acid or its amide-forming derivative and diamine as essential constituent monomers, polyamide (am2) obtained by ring-opening polymerization of lactam with dicarboxylic acid or monocarboxylic acid, polyamide (am3) obtained by ring-opening polymerization of lactam with water, diamine or monoamine, polyamide (am4) obtained by polycondensing aminocarboxylic acid, and polyamide (am5) obtained by one-shot synthesis of at least two or more of (am1) to (am4). The block (am) of polyamide may be used alone or in combination of two or more.

[0008] Examples of the dicarboxylic acid used in polyamide (am1) and (am2) include dicarboxylic acids having 2 to 20 carbon atoms [aliphatic dicarboxylic acids having 2 to 20 carbon atoms (such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, maleic acid, fumaric acid, and itaconic acid), aromatic dicarboxylic acids having 8 to 20 carbon atoms (such as terephthalic acid, phthalic acid, 2,6- or 2,7-naphthalenedicarboxylic acid, diphenyl-4,4'-dicarboxylic acid, diphenoxyethanedicarboxylic acid, tolylene dicarboxylic acid, xylylene dicarboxylic acid, and 5-sulfoisophthalic acid), and alicyclic dicarboxylic acids having 5 to 20 carbon atoms (such as cyclopropanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, cyclohexenedicarboxylic acid, bicyclohexyl-4,4'-dicarboxylic acid, and camphoric acid), etc.].

[0009] Examples of amide-forming derivatives of dicarboxylic acids include alkyl (having 1 to 4 carbon atoms) esters of dicarboxylic acids (such as methyl esters and ethyl esters) and acid anhydrides of dicarboxylic acids. The dicarboxylic acid and its amide-forming derivative may each be used alone or in combination of two or more. As the diamine, diamines having 2 to 12 carbon atoms can be used, and specifically, ethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, decamethylenediamine, etc. can be mentioned.

[0010] Among the dicarboxylic acids and their amide-forming derivatives used in polyamide (am1), from the viewpoints of mechanical strength, dimensional stability, and appearance, aliphatic dicarboxylic acids having 2 to 20 carbon atoms, aromatic dicarboxylic acids having 8 to 20 carbon atoms, and their amide-forming derivatives are preferable, more preferably aliphatic dicarboxylic acids having 2 to 20 carbon atoms and their amide-forming derivatives, particularly preferably aliphatic dicarboxylic acids having 6 to 12 carbon atoms and their amide-forming derivatives, especially preferably adipic acid, undecanedioic acid, dodecanedioic acid, and their amide-forming derivatives, and most preferably adipic acid and its amide-forming derivative.

[0011] Among the dicarboxylic acids and their amide-forming derivatives used in polyamide (am2), from the viewpoints of mechanical strength, dimensional stability, and appearance, aliphatic dicarboxylic acids having 2 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms are preferable, more preferably aromatic dicarboxylic acids having 8 to 20 carbon atoms (such as terephthalic acid, phthalic acid, 2,6- or 2,7-naphthalenedicarboxylic acid, diphenyl-4,4'-dicarboxylic acid, diphenoxyethanedicarboxylic acid, tolylene dicarboxylic acid, xylylene dicarboxylic acid, and 5-sulfoisophthalic acid), and particularly preferably terephthalic acid, 2,6- or 2,7-naphthalenedicarboxylic acid.

[0012] Examples of the diamine used in polyamide (am1) and (am3) include the above-mentioned aliphatic diamines having 2 to 12 carbon atoms. Among these, preferred are aliphatic diamines having 6 and 10 carbon atoms, more preferred are 1,6-diaminohexane and 1,10-diaminodecane, and particularly preferred is 1,6-diaminohexane. The diamine may be used alone or in combination of two or more.

[0013] Examples of the monocarboxylic acid used in polyamide (am2) include carboxylic acids having 1 to 20 carbon atoms (capric acid, lauric acid, myristic acid, benzoic acid, t-butylbenzoic acid, 2-naphthalenecarboxylic acid, etc.).

[0014] Examples of the monoamine used in polyamide (am3) include monoamines having 1 to 20 carbon atoms (methylamine, ethylamine, propylamine, hexylamine, octylamine, decylamine, dodecylamine, etc.).

[0015] From the viewpoints of ease of synthesis and dimensional stability, preferred lactams used in polyamides (am2) and (am3) are ε-caprolactam, 11-undecanolactam, and 12-laurolactam, and more preferred is ε-caprolactam.

[0016] Examples of the aminocarboxylic acid used in polyamide (am4) include aminocarboxylic acids having 2 to 12 (preferably 4 to 12, more preferably 6 to 12) carbon atoms, etc., and specifically include amino acids (glycine, alanine, valine, leucine, isoleucine, phenylalanine, etc.), ω-aminocaproic acid, ω-aminoenanthic acid, ω-aminocaprylic acid, ω-aminopelargonic acid, ω-aminocapric acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid, etc. Among the above amino carboxylic acids, from the viewpoints of ease of synthesis and dimensional stability, glycine, leucine, 8-aminocaprylic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid are preferred, more preferably 8-aminocaprylic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid, particularly preferably 11-aminoundecanoic acid and 12-aminododecanoic acid, and most preferably 12-aminododecanoic acid.

[0017] The carboxyl groups of the polyamide block (am) are represented by the acid value (mgKOH / g), and the amino groups of the (am) are represented by the amine value (mgKOH / g). Moreover, it is preferable to use a polyamide having a carboxyl group at one end (hereinafter sometimes referred to as polyamide monocarboxylic acid). The polyamide monocarboxylic acid can be obtained by a method of adjusting the molar ratio of a dicarboxylic acid and a diamine; a method of adjusting the molar ratio of a dicarboxylic acid and a diamine in the coexistence of a monocarboxylic acid; a method of ring-opening polymerization of a lactam with a monocarboxylic acid; a method of polycondensing an aminocarboxylic acid, and the like.

[0018] Moreover, from the viewpoints of dimensional stability and mechanical strength, the polyamide block (am) is preferably a polyamide having at least one selected from the group consisting of 1,6-diaminohexane, 1,10-diaminodecane, ε-caprolactam, 11-undecanolactam, 12-laurolactam, 11-aminoundecanoic acid, and 12-aminododecanoic acid as an essential constituent monomer.

[0019] The number average molecular weight (Mn) of the polyamide block (am) is preferably 500 to 10,000, more preferably 1,000 to 6,000, and particularly preferably 2,000 to 6,000, from the viewpoints of mechanical strength, dimensional stability, and appearance.

[0020] The number average molecular weight (Mn) and weight average molecular weight (Mw) of the polymer in the present invention can be measured under the following conditions using gel permeation chromatography (GPC). · Device (example): "HLC-8120" [manufactured by Tosoh Corporation] · Column (example): "TSKgel GMHXL" [manufactured by Tosoh Corporation] (2 columns) "TSKgel Multipore HXL-M" [manufactured by Tosoh Corporation] (1 column) · Sample solution: 0.3 wt% orthodichlorobenzene solution · Solution injection volume: 100 μl · Flow rate: 1 ml / min · Measurement temperature: 135 °C · Detection device: Refractive index detector · Reference substance: Standard polystyrene (TSK standard POLYSTYRENE) 12 points (molecular weights: 500, 1,050, 2,800, 5,970, 9,100, 18,100, 37,900, 96,400, 190,000, 355,000, 1,090,000, 2,890,000) [manufactured by Tosoh Corporation]

[0021] As a method for producing the polyamide block (am), a general polyamide production method can be directly applied. The polyamidation reaction is carried out in a temperature range of 150 to 300 °C under reduced pressure, and the reaction time is preferably 0.5 to 20 hours. Also, a catalyst generally used in the polyamidation reaction may be used if necessary.

[0022] <Polymer block (b) of polysiloxane> As the polysiloxane block (b) in the present invention, for example, a polysiloxane having a functional group reactive with the above (am) can be mentioned. Specifically, a polysiloxane (b1) having functional groups reactive with the above (am) at both ends and a polymer (b2) containing a polysiloxane having a functional group reactive with the above (am) at one end can be mentioned. Note that examples of the functional group reactive with (am) include a hydroxyl group, a primary amino group, a carboxyl group, and an epoxy group. For example, when (am) has a primary amino group, examples of the reactive functional group include a carboxyl group, an epoxy group, etc. When (am) has a carboxyl group, examples of the reactive functional group include a primary amino group, a hydroxyl group, an epoxy group, etc.

[0023] Examples of (b) include polysiloxanes having a hydroxyl group [e.g., trade names "X-22-4015", "X-22-4039", manufactured by Shin-Etsu Silicone], polysiloxanes having a primary amino group [e.g., trade names "KF-865", "KF859", manufactured by Shin-Etsu Silicone], polysiloxanes having a carboxyl group [e.g., trade name "X-22-3710E", manufactured by Shin-Etsu Silicone], polysiloxanes having an epoxy group [e.g., trade names "X-22-343", "KF-1001", manufactured by Shin-Etsu Silicone], etc.

[0024] From the viewpoints of mechanical strength, dimensional stability, and appearance, the number average molecular weight (Mn) of (b) is preferably 500 to 10,000, more preferably 1,000 to 6,000, and particularly preferably 2,000 to 5,000.

[0025] <Block polymer (X)> The block polymer (X) in the present invention has a block (am) of the polyamide and a block (b) of the polysiloxane as constituent units.

[0026] From the viewpoints of mechanical strength, dimensional stability, and appearance, the preferred structure of (X) is (1): (am)-(b) diblock type structure or (2): (b)-(am)-(b) triblock type structure, and more preferably (am)-(b) diblock type structure.

[0027] Block polymers having the molecular structures (1) to (2) above can be obtained, for example, by the following method.

[0028] A block polymer having a linear (am)-(b) diblock type structure can be produced, for example, by reacting a polyamide having a carboxyl group at one end and a polysiloxane having a primary amino group at one end in a molar ratio of 1:1.

[0029] A block polymer having a linear (b)-(am)-(b) triblock type structure can be produced, for example, by reacting a polyamide having carboxyl groups at both ends and a polysiloxane having a primary amino group at one end in a molar ratio of 1:2.

[0030] In the above, an example of the combination of the polyamide (am) and the polysiloxane (b) when obtaining the block polymer (X) having each structure was shown. However, as described above, since (am) and (b) have various functional groups, any combination can be appropriately adopted as long as the functional group of (am) and the functional group of (b) can react with each other.

[0031] (X) preferably has a structure in which the block (am) of the polyamide and the block (b) of the polysiloxane are bonded via an amide bond, an imide bond, an ester bond or an epoxy ring-opening bond. From the viewpoint of ease of production, an ester bond or an amide bond is more preferable.

[0032] From the viewpoints of mechanical strength, dimensional stability and appearance, the Mn of (X) is preferably 3,000 to 30,000, more preferably 4,000 to 25,000, and particularly preferably 5,000 to 20,000.

[0033] From the viewpoints of mechanical strength and dimensional stability, the weight ratio [(am) / (b)] of the block (am) of the polyamide and the block (b) of the polysiloxane constituting the block polymer (X) is preferably 25 / 75, more preferably 35 / 65 to 75 / 25, and particularly preferably 40 / 60 to 70 / 30.

[0034] When (X) has a structure in which (am) and (b) are bonded via an amide bond or an ester bond, for example, (am) and (b) are put into a reaction vessel, and while removing water generated by an amidation reaction, an imidization reaction, or an esterification reaction (hereinafter abbreviated as generated water) out of the reaction system under stirring at a reaction temperature of 100 to 250 °C and a pressure of 0.003 to 0.1 MPa, it can be produced by a method of reacting for 1 to 50 hours.

[0035] <Modifier (Y) for polyamide resin> The modifier (Y) for polyamide resin of the present invention contains the above-mentioned block polymer (X). The modifier (Y) for polyamide resin can be suitably used as a modifier for a polyamide resin (C) described later, particularly as a dimensional stabilizer for polyamide resin.

[0036] The modifier (Y) for polyamide resin can contain additives (D) such as a colorant (D1), a release agent (D2), an antioxidant (D3), a flame retardant (D4), an ultraviolet absorber (D5), an antibacterial agent (D6), a compatibilizer (D7), a filler (D8), and a transesterification inhibitor (D9) described later.

[0037] <Polyamide resin composition (Z)> The polyamide resin composition (Z) of the present invention contains the modifier (Y) for polyamide resin and a polyamide resin (C). The weight ratio [(Y) / (C)] of the modifier (Y) for polyamide resin to the polyamide resin (C) is preferably 1 / 99 to 20 / 80, more preferably 2 / 98 to 15 / 85, and particularly preferably 3 / 97 to 10 / 90 from the viewpoints of dimensional stability and mechanical properties.

[0038] <Polyamide resin (C)> As the polyamide resin (C) in the present invention, there may be mentioned thermoplastic polymers having an amide bond using an amino acid, a lactam or a diamine and a dicarboxylic acid as starting materials. Examples of the amino acid include 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, para-aminomethylbenzoic acid and the like, and examples of the lactam include ε-caprolactam, ω-laurolactam and the like.

[0039] Examples of the diamine include aliphatic ones (having 4 to 15 carbon atoms, such as tetramethylenediamine, hexamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine, 2,4-dimethyloctamethylenediamine), aromatic ring-containing ones (having 6 to 20 carbon atoms, such as metaxylylenediamine, paraxylylenediamine), aromatic ones (having 6 to 20 carbon atoms, such as phenylenediamine), alicyclic ring-containing ones [having 6 to 20 carbon atoms, such as 1,3-bis(aminomethyl)cyclohexane, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, 3,8-bis(aminomethyl)tricyclodecane, bis(4-aminocyclohexyl)methane, bis(3-methyl-4-aminocyclohexyl)methane, 2,2-bis(4-aminocyclohexyl)propane], and heterocyclic ring-containing ones [having 6 to 15 carbon atoms, such as bis(aminopropyl)piperazine, aminoethylpiperazine] and the like.

[0040] Examples of the dicarboxylic acid include aliphatic ones (having 6 to 20 carbon atoms, such as adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid), aromatic ring-containing ones (having 8 to 20 carbon atoms, such as terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodium sulfoisophthalic acid), and alicyclic ring-containing ones (having 8 to 20 carbon atoms, such as hexahydroterephthalic acid, hexahydroisophthalic acid, diglycolic acid) and the like.

[0041] Specific examples of (C) include polycaproamide (nylon 6), polytetramethylene adipamide (nylon 46), polyhexamethylene adipamide (nylon 66), polyhexamethylene sebacamide (nylon 6 / 10), polyhexamethylene dodecamide (nylon 6 / 12), polyundecamethylene adipamide (nylon 11 / 6), polyundecanamide (nylon 11), polydodecanamide (nylon 12), polytrimethylhexamethylene terephthalamide, polyhexamethylene isophthalamide (nylon 6I), polyhexamethylene terephthalate / isophthalamide (nylon 6T / 6I), polybis(4-aminocyclohexyl)methane dodecamide (nylon PACM12), polybis(3-methyl-4-aminocyclohexyl)methane dodecamide (nylon dimethyl PACM12), polymetaxylylene adipamide (nylon MXD6), polyundecamethylene terephthalamide (nylon 11T), polyundecamethylene hexahydroterephthalamide [nylon 11T(H)], and copolymers thereof with these polyalkylene glycols (Mn 100 to 1,000, such as polyethylene glycol and polytetramethylene glycol), and copolyamides composed of these [e.g., polycapramide / polyhexamethylene adipamide (nylon 6 / 66), polycapramide / polydodecanamide copolymer (nylon 6 / 12)]. These (C) may be used alone or in admixture of two or more.

[0042] Among the above polyamide resins (C), from the viewpoint of the modification effect, nylon 6, nylon 46, nylon 66, nylon 11, nylon 12, and copolyamides and mixed polyamides thereof are preferred. Among these, from the viewpoint of moldability, nylon 6 and nylon 66 are particularly preferred. The Mn of the polyamide resin (C) is preferably 11,000 to 30,000, more preferably 12,000 to 25,000, and particularly preferably 13,000 to 20,000.

[0043] In the polyamide resin composition (Z), additives (D) such as a colorant (D1) [azo pigment, etc.], a release agent (D2) [liquid paraffin, etc.], an antioxidant (D3) [triphenyl phosphite, etc.], a flame retardant (D4) [antimony trioxide, etc.], an ultraviolet absorber (D5) [phenyl salicylate, etc.], an antibacterial agent (D6) [benzimidazole, etc.], a compatibilizer (D7) [modified vinyl copolymer, etc.], a filler (D8) [calcium carbonate, etc.] and a transesterification inhibitor (D9) [monooctadecyl phosphate, etc.] can be contained as long as the effects of the present invention are not inhibited. Each additive may be used alone or in combination of two or more kinds.

[0044] Based on the weight of the polyamide resin (C), the total content of (D) is generally 45% by weight or less, preferably 0.001 to 40% by weight, more preferably 0.01 to 35% by weight from the viewpoints of the effects of each additive and the mechanical strength of the molded article; the content of each (D) is preferably 0.1 to 3% by weight, more preferably 0.2 to 2% by weight for (D1); preferably 0.01 to 3% by weight, more preferably 0.05 to 1% by weight for (D2); preferably 0.01 to 3% by weight, more preferably 0.05 to 1% by weight for (D3); preferably 0.5 to 20% by weight, more preferably 1 to 10% by weight for (D4); preferably 0.01 to 3% by weight, more preferably 0.05 to 1% by weight for (D5); preferably 0.5 to 20% by weight, more preferably 1 to 10% by weight for (D6); preferably 0.5 to 10% by weight, more preferably 1 to 5% by weight for (D7); preferably 0.5 to 10% by weight, more preferably 1 to 5% by weight for (D8); and 0.01 to 3% by weight, more preferably 0.05 to 1% by weight for (D9).

[0045] The polyamide resin composition (Z) of the present invention can be obtained by melt-mixing the modifier (Y) for polyamide resin of the present invention, the polyamide resin (C) and, if necessary, the additive (D). At this time, an additive (D) similar to the additive (D) contained in the modifier (Y) for polyamide resin may be added to the polyamide resin composition (Z). As a method of melt mixing, generally, each component in the form of pellets or powder is mixed with an appropriate mixer (such as a Henschel mixer), and then melt mixed with an extruder and pelletized.

[0046] There is no particular limitation on the addition order of each component during melt mixing. For example, [1] A method of melt mixing (C) and (Y), and then, if necessary, batch charging (D) and melt mixing; [2] When melt mixing (C) and (Y), a part of (C) is melt mixed in advance to prepare a high-concentration composition of (Y) (masterbatch resin composition), and then the remaining (C) and, if necessary, (D) are melt mixed (masterbatch method or master pellet method); etc. can be mentioned. In the method [2], the concentration of (Y) in the masterbatch resin composition is preferably 20 to 80% by weight, more preferably 50 to 70% by weight. From the viewpoint that (Y) is easily dispersed efficiently in (C), the method [2] is preferable among the methods [1] and [2].

[0047] <Molded article> The molded article of the present invention is obtained by molding the polyamide resin composition (Z). Examples of the molding method include injection molding, compression molding, calender molding, slush molding, rotational molding, extrusion molding, blow molding, and film molding (such as casting method, tenter method, and inflation method), etc., and it can be molded by any method incorporating means such as single-layer molding, multi-layer molding, or foam molding according to the purpose.

[0048] The molded article of the present invention has low water absorption and imparts excellent dimensional stability. Further, it gives excellent mechanical strength (mechanical properties) and excellent appearance.

[0049] The modifier (Y) for polyamide resin of the present invention, and the molded article of the polyamide resin composition (Z) containing the (Y) and the polyamide resin (C) are excellent in dimensional stability, mechanical strength, and appearance, and thus can be suitably used for various molded article applications, precision part applications, automotive part applications, and daily necessity applications.

Example

[0050] Hereinafter, examples of the present invention will be described, but the present invention is not limited thereto. In the following, "parts" indicate parts by weight.

[0051] <Production Example 1> [One-terminal acid-modified polyamide (am-1)] Into a stainless steel pressure-resistant reaction vessel equipped with a stirrer, a thermometer, a heating and cooling device, a nitrogen inlet pipe, and a decompression device, 200 parts of 1,6-diaminohexane, 203 parts of terephthalic acid, and 1.5 parts of an antioxidant ["Irganox 1010", manufactured by Ciba Specialty Chemicals Inc.] were charged. After nitrogen substitution, the temperature was raised to 250 °C with stirring under sealing, and stirred at the same temperature (pressure: 0.2 to 0.5 MPa) for 4 hours to obtain one-terminal acid-modified polyamide (am-1). The amine value of (am-1) was 37 mgKOH / g, the acid value was 37 mgKOH / g, and Mn was 1,500.

[0052] <Production Example 2> [One-terminal acid-modified polyamide (am-2)] Into a stainless steel pressure-resistant reaction vessel equipped with a stirrer, a thermometer, a heating and cooling device, a nitrogen inlet pipe, and a decompression device, 430 parts of ε-caprolactam, 16 parts of dodecylamine, 1.5 parts of an antioxidant ["Irganox 1010", manufactured by Ciba Specialty Chemicals Inc.], and 20 parts of water were charged. After nitrogen substitution, the temperature was raised to 250 °C with stirring under sealing, and stirred at the same temperature (pressure: 0.2 to 0.5 MPa) for 4 hours to obtain one-terminal acid-modified polyamide (am-2). The amine value of (am-2) was 0 mgKOH / g, the acid value was 11 mgKOH / g, and Mn was 5,000.

[0053] <Production Example 3> [One-terminal acid-modified polyamide (am-3)] Into a stainless steel pressure-resistant reaction vessel equipped with a stirrer, a thermometer, a heating and cooling device, a nitrogen inlet pipe, and a decompression device, 440 parts of 12-aminododecanoic acid, 5 parts of benzoic acid, and 1.5 parts of an antioxidant [“Irganox 1010”, manufactured by Ciba Specialty Chemicals Inc.] were charged. After nitrogen substitution, the temperature was raised to 250 °C with stirring under sealing, and stirring was carried out at the same temperature (pressure: 0.2 to 0.5 MPa) for 4 hours to obtain a mono-terminal acid-modified polyamide (am-3). Incidentally, the amine value of (am-3) was 0 mgKOH / g, the acid value was 5.6 mgKOH / g, and Mn was 10,000.

[0054] <Production Example 4> [Both-terminal acid-modified polyamide (am-4)] Into a stainless steel pressure-resistant reaction vessel equipped with a stirrer, a thermometer, a heating and cooling device, a nitrogen inlet pipe, and a decompression device, 450 parts of ε-caprolactam, 39 parts of terephthalic acid, 1.5 parts of an antioxidant [“Irganox 1010”, manufactured by Ciba Specialty Chemicals Inc.], and 20 parts of water were charged. After nitrogen substitution, the temperature was raised to 250 °C with stirring under sealing, and stirring was carried out at the same temperature (pressure: 0.2 to 0.5 MPa) for 4 hours to obtain a both-terminal acid-modified polyamide (am-4). Incidentally, the amine value of (am-4) was 0 mgKOH / g, the acid value was 56 mgKOH / g, and Mn was 2,000.

[0055] <Production Example 5> [Both-terminal acid-modified polyamide (am-5)] Into a stainless steel pressure-resistant reaction vessel equipped with a stirrer, a thermometer, a heating and cooling device, a nitrogen inlet pipe, and a decompression device, 430 parts of ε-caprolactam, 14 parts of terephthalic acid, 1.5 parts of an antioxidant [“Irganox 1010”, manufactured by Ciba Specialty Chemicals Inc.], and 20 parts of water were charged. After nitrogen substitution, the temperature was raised to 250 °C with stirring under sealing, and stirring was carried out at the same temperature (pressure: 0.2 to 0.5 MPa) for 4 hours to obtain a both-terminal acid-modified polyamide (am-5). Incidentally, the amine value of (am-5) was 0 mgKOH / g, the acid value was 22 mgKOH / g, and Mn was 5,000.

[0056] <Production Example 6> [Both-terminal acid-modified polyamide (am-6)] In a stainless steel pressure-resistant reaction vessel equipped with a stirrer, a thermometer, a heating and cooling device, a nitrogen inlet pipe, and a decompression device, 430 parts of 12-aminododecanoic acid, 7 parts of 2,7-naphthalenedicarboxylic acid, and 1.5 parts of an antioxidant ["Irganox 1010", manufactured by Ciba Specialty Chemicals Co., Ltd.] were charged. After nitrogen substitution, the temperature was raised to 250 °C with stirring under sealing, and the mixture was stirred at the same temperature (pressure: 0.2 to 0.5 MPa) for 4 hours to obtain an acid-modified polyamide (am-6) with both ends. The amine value of (am-6) was 0 mgKOH / g, the acid value was 11 mgKOH / g, and Mn was 10,000.

[0057] <Production Example 7> [α-Butyl-ω-amino-modified polydimethylsiloxane (b-1)] Into a reaction vessel equipped with a stirrer, a thermometer, and a cooling pipe, 400 parts of a linear polydimethylsiloxane (Mn = 1900) with one end blocked by a butyl group and the other end having an SiH bond, and a suspension in which 0.240 part of platinum oxide was suspended in 56 parts of allylamine were charged, and the reaction was carried out with stirring at 105 °C for 16 hours. After cooling to room temperature, the reaction mixture was passed through a membrane filter (polytetrafluoroethylene [PTFE], pore size 0.45 μm) to remove insoluble substances. Thereafter, the excess allylamine contained in the filtrate was removed under reduced pressure to obtain α-butyl-ω-amino-modified polydimethylsiloxane (b-1). The Mn of (b-1) was 2,000.

[0058] <Production Example 8> [α-Methyl-ω-terminal carbinol-modified polydimethylsiloxane (b-2)] Into a reaction vessel equipped with a stirrer, a thermometer, and a cooling tube, 400 parts of a linear polydimethylsiloxane (Mn = 400) with one end blocked by a methyl group and the other end having an SiH bond and a suspension in which 1.15 parts of platinum oxide was suspended in 480 parts of ethylene glycol monoallyl ether were charged, and the mixture was reacted with stirring at 105 °C for 16 hours. After cooling to room temperature, the reaction mixture was passed through a membrane filter (polytetrafluoroethylene [PTFE], pore size 0.45 μm) to remove insoluble substances. Thereafter, the excess ethylene glycol monoallyl ether contained in the filtrate was removed under reduced pressure to obtain α-methyl-ω-carbinol-modified polydimethylsiloxane (b-2). The Mn of (b-2) was 500.

[0059] <Production Example 9> [α-Methyl-ω-terminal carbinol-modified polydimethylsiloxane (b-3)] Into a reaction vessel equipped with a stirrer, a thermometer, and a cooling tube, 400 parts of a linear polydimethylsiloxane (Mn = 1400) with one end blocked by a methyl group and the other end having an SiH bond and a suspension in which 0.33 part of platinum oxide was suspended in 140 parts of ethylene glycol monoallyl ether were charged, and the mixture was reacted with stirring at 105 °C for 16 hours. After cooling to room temperature, the reaction mixture was passed through a membrane filter (polytetrafluoroethylene [PTFE], pore size 0.45 μm) to remove insoluble substances. Thereafter, the excess ethylene glycol monoallyl ether contained in the filtrate was removed under reduced pressure to obtain α-methyl-ω-carbinol-modified polydimethylsiloxane (b-3). The Mn of (b-3) was 1,500.

[0060] <Production Example 10> [α-Methyl-ω-terminal carbinol-modified polydimethylsiloxane (b-4)] In a reaction vessel equipped with a stirrer, a thermometer, and a cooling pipe, 400 parts of a linear polydimethylsiloxane (Mn = 4900) having one end blocked with a methyl group and the other end having an SiH bond and a suspension obtained by suspending 0.096 part of platinum oxide in 40 parts of ethylene glycol monoallyl ether were charged, and the mixture was reacted at 105 °C with stirring for 16 hours. After cooling to room temperature, the reaction mixture was passed through a membrane filter (polytetrafluoroethylene [PTFE], pore size 0.45 μm) to remove insoluble matters. Thereafter, the excess ethylene glycol monoallyl ether contained in the filtrate was removed under reduced pressure to obtain α-methyl-ω-carbinol-modified polydimethylsiloxane (b-4). The Mn of (b-4) was 5,000.

[0061] <Production Example 11> [α-Methyl-ω-terminal carbinol-modified polydimethylsiloxane (b-5)] In a reaction vessel equipped with a stirrer, a thermometer, and a cooling pipe, 400 parts of a linear polydimethylsiloxane (Mn = 9900) having one end blocked with a methyl group and the other end having an SiH bond and a suspension obtained by suspending 0.047 part of platinum oxide in 20 parts of ethylene glycol monoallyl ether were charged, and the mixture was reacted at 105 °C with stirring for 16 hours. After cooling to room temperature, the reaction mixture was passed through a membrane filter (polytetrafluoroethylene [PTFE], pore size 0.45 μm) to remove insoluble matters. Thereafter, the excess ethylene glycol monoallyl ether contained in the filtrate was removed under reduced pressure to obtain α-methyl-ω-carbinol-modified polydimethylsiloxane (b-5). The Mn of (b-5) was 10,000.

[0062] <Example 1> Into a reaction vessel equipped with a stirrer, a thermometer, and a heating and cooling device, 100 parts of polyamide (am-1), 100 parts of polysiloxane (b-2), and 0.3 part of antioxidant "Irganox 1010" were charged, and the temperature was raised to 210 °C with stirring, and the reaction was carried out at the same temperature under reduced pressure (0.013 MPa or less) for 5 hours to obtain a modifier (Y-1) for polyamide resin containing block polymer (X-1).

[0063] <Examples 2 to 6, Comparative Example 1> The same procedure as in Example 1 was carried out except that the raw materials used and their amounts used were changed to those shown in Table 1, and each polyamide resin modifier (Y) was obtained. For the modifier for polyamide resin for comparison (Ratio Y-1), commercially available maleic anhydride-modified polypropylene [Mn 4000, acid value 22 mgKOH / g] was used as it was. The results are shown in Table 1. Note that Example 6 is a reference example.

[0064]

Table 1

[0065] <Examples 11 to 24, Comparative Examples 11 to 13> According to the compounding compositions (parts) shown in Table 2, after blending each compounding component with a Henschel mixer for 3 minutes, it was melt-kneaded with a twin-screw extruder with a vent at 100 rpm, 220 °C, and a residence time of 5 minutes to obtain each polyamide resin composition (Z). Note that Examples 23 and 24 are reference examples.

[0066] The compounding components shown in Table 2 are as follows. Polyamide resin (C-1): Polyamide 6 [trade name "UBE1013B", manufactured by Ube Industries, Ltd., Mn 13,000]

[0067] For each of the obtained resin compositions, using an injection molding machine ["PS40E5ASE", manufactured by Nissei Plastic Industrial Co., Ltd.], molding test pieces were produced at a cylinder temperature of 240 °C and a mold temperature of 50 °C, and the results of evaluation by the following performance tests are shown in Table 2. In evaluation (2), the following thermo-hygrostat was used. · Equipment: Thermo-hygrostat [manufactured by Isuzu Manufacturing Co., Ltd., TPAV-48-20]

[0068] <Performance Test> (1) Equilibrium water absorption time (hr) In accordance with JIS K7209, the time until the water absorption rate (%) of the test piece (80×80×1 mm) reached an equilibrium state was measured.

[0069] (2) Dimensional change rate (%) <parallel, perpendicular> before and after the moisture absorption test In accordance with JIS K7143, a moisture absorption promotion test was conducted on a flat test piece (80×80×2 mm) in an atmosphere of 70°C / 62%RH. The equilibrium moisture content (%) under the above conditions is close to the moisture absorption equilibrium rate (%) in an atmosphere of 23°C / 50%RH. The dimensions (mm) in the dry state and the dimensions (mm) at moisture absorption equilibrium were measured, and the dimensional change rate (%) was calculated. Dimensional change rate (%) = [(dimension: after moisture absorption test) - (dimension: dry state)] × 100 / (dimension: dry state) Note that "parallel" means the same direction as the flow of the resin in injection molding, and "perpendicular" means the direction perpendicular to the flow of the resin.

[0070] (3) Appearance The appearance of the surface of the test piece (80×80×1 mm) was visually observed and evaluated according to the following criteria. ○: Good without abnormality (equivalent to a thermoplastic resin not containing a resin modifier) ×: Surface roughness, swelling, etc. are observed.

[0071] (4) Reduction rate of mechanical strength (Izod impact strength) The reduction rate of the mechanical strength when a modifier (Y) for polyamide resin was blended with polyamide resin (C) was evaluated for the Izod impact strength. Izod impact strength (unit: J / m) Measured in accordance with ASTM D256 Method A (notched, 3.2 mm thick). Note that the reduction rate of the mechanical strength also varies depending on the blending amount of the resin modifier (Y). To clarify the reduction rate depending on the type of modifier (Y), the reduction rate at a specific blending amount was divided by the blending weight % of the modifier (Y) at that time for evaluation. That is, evaluation was performed according to the following evaluation criteria using the reduction rate of mechanical strength (% / wt%) obtained by the following formula.

[0072] [Reduction rate of mechanical strength (% / wt%)]= {[Mechanical strength before compounding]-[Mechanical strength after compounding]} / [Mechanical strength before compounding] / [Compounding weight of resin modifier]×100 (%) For example, when 10 wt% of a modifier (Y) is compounded with a resin before compounding (Izod impact strength = 2.0 J / m) and the Izod impact strength after compounding is 1.8 J / m, the calculation formula is as follows. [Reduction rate of mechanical strength (% / wt%)]= [2.0 (J / m)-1.8 (J / m)] / 2.0 (J / m) / 10 (wt%)×100 (%) = 1.0 (% / wt%)

[0073] <Evaluation criteria> ◎: [Reduction rate]≦0.5 ○: 0.5 <[Reduction rate]≦2.5 △: 2.5 <[Reduction rate]≦5.5 ×: 5.5 <[Reduction rate]

[0074]

Table 2

[0075] From the results of Tables 1 and 2, the modifier (Y) for polyamide resin of the present invention reduces the water absorption of the molded product of the polyamide resin composition and imparts excellent dimensional stability as compared with the comparative ones. Also, it can be seen that the molded product has excellent mechanical strength (mechanical properties) and excellent appearance.

Industrial applicability

[0076] The resin modifier (Y) of the present invention and the molded product of the polyamide resin composition (Z) containing the (Y) and the polyamide resin (C) are excellent in dimensional stability, mechanical strength, and appearance, and thus can be suitably used for various molded product applications, precision part applications, automotive part applications, and daily necessity applications.

Claims

1. A modifier (Y) for polyamide resin, comprising a block polymer (X) having polyamide blocks (am) and polysiloxane blocks (b) as constituent units, wherein the block polymer (X) has a structure in which the polyamide block (am) and the polysiloxane block (b) are bonded via an ester bond, and is a modifier (Y) for polyamide resin.

2. The modifier for polyamide resin according to Claim 1, wherein the number average molecular weight (Mn) of the polyamide block (am) is 500 to 10,000.

3. The modifier for polyamide resin according to Claim 1 or 2, wherein the number average molecular weight (Mn) of the polysiloxane block (b) is 500 to 10,000.

4. The modifier for polyamide resin according to any one of Claims 1 to 3, wherein the block polymer (X) has an (am)-(b) diblock structure or a (b)-(am)-(b) triblock structure.

5. The modifier for polyamide resin according to any one of Claims 1 to 4, wherein the number average molecular weight (Mn) of the block polymer (X) is 3,000 to 30,000.

6. The modifier for polyamide resin according to any one of Claims 1 to 5, wherein the weight ratio [(am) / (b)] of the polyamide block (am) to the polysiloxane block (b) is 25 / 75 to 75 / 25.

7. A polyamide resin composition (Z) comprising the modifier (Y) for polyamide resin according to any one of Claims 1 to 6 and a polyamide resin (C).

8. The polyamide resin composition according to Claim 7, wherein the weight ratio [(Y) / (C)] of the modifier (Y) for polyamide resin to the polyamide resin (C) is 1 / 99 to 20 / 80.

9. A molded article formed by molding the polyamide resin composition (Z) according to Claim 8.

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