JP2005138441A - Method for accelerating crystallization of polyamide resin and polyamide formed product excellent in crystallinity - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for accelerating the crystallization of a polyamide resin which can accelerate the crystallization of the resin from its surface when the resin is processed, improve the processing cycle of the resin by the acceleration of crystallization, and provide a polyamide formed product excellent in crystallinity. <P>SOLUTION: In the method for accelerating the crystallinity of the aliphatic polyamide resin, the resin is brought into contact with a substrate whose surface free energy is 42-48 mN/m. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for promoting crystallization of a polyamide resin by contacting the polyamide resin with a substrate having a specific surface free energy (γ).

  Polyamides such as nylon-6 and nylon-66 have excellent processability, chemical resistance, electrical properties, mechanical properties, etc., so injection molded products, hollow molded products, films, sheets, fibers, etc. And is used for various purposes. However, polyamide has a low crystallization rate and thus has a low crystallinity and a long processing cycle, and a crystal nucleating agent such as talc is added to improve rigidity and heat resistance.

For example, an inorganic crystal nucleating agent and a fatty acid metal salt are used in combination with polyamide (see Patent Document 1), a metal salt of rosin is blended with a polyamide as a crystal nucleating agent (see Patent Document 2), and fibrous zonotlite is converted into a polyamide. (See Patent Documents 3 and 4), monoterpene diphenols or metal salts of monoterpene diphenols as polyamide nucleating agents (see Patent Document 5), fat reinforced with glass fibers It has been proposed to blend a semi-aromatic polyamide with an aromatic polyamide (see Patent Document 6).
Claims of JP-A-5-194441 Claims of JP-A-8-59883 Claims of JP-A-6-128412 Claims of JP-A-10-273590 Claims of JP-A-11-158370 Claims of JP-A-4-23863

  However, a method of adding a crystal nucleating agent such as talc does not provide a sufficient crystallization speed and crystallinity, and a polyamide having sufficient resin strength due to the difference in crystallinity between the resin surface and the resin interior. There was a problem that the resin could not be obtained.

  As a result of intensive studies to solve the above problems, the present inventors have promoted the crystallization of the resin surface by bringing it into contact with a substrate having a surface free energy of 42 to 48 mN / m during processing of the polyamide, The present inventors have found that a polyamide having an excellent degree of crystallinity can be molded with good cycleability, and have reached the present invention.

  That is, the present invention provides a method for accelerating crystallization of a polyamide resin, wherein the aliphatic polyamide resin is brought into contact with a substrate having a surface free energy of 42 to 48 mN / m.

  According to the method for promoting crystallization of a polyamide resin of the present invention, crystallization of the polyamide resin can be promoted from the resin surface during the processing of the polyamide resin. Further, by promoting crystallization, the processing cycle is improved and a polyamide molded product having excellent crystallinity can be provided.

Hereinafter, the method for promoting crystallization of the polyamide resin of the present invention will be described in detail.
Examples of the aliphatic polyamide resin used in the present invention include homopolyamide and copolyamide obtained by polymerization of lactam or aminocarboxylic acid or polycondensation of diamine and carboxylic acid, and mixtures thereof. Specific examples include homopolymers such as nylon 6, nylon 66, nylon 46, nylon 610, nylon 612, nylon 11 and nylon 12, and copolymers or mixtures containing these two or more components.

The substrate used in the present invention is not particularly limited as long as the surface free energy is 42 to 48 mN / m, and may be inorganic or organic.
The contact between the aliphatic polyamide resin and the base material may be achieved, for example, by using a resin molding surface (for example, a surface of a mold or a die) of a molding machine that molds the aliphatic polyamide resin, the surface free energy. Of the aliphatic polyamide resin by forming with a base material having a surface roughness of 42 to 48 mN / m, or by treating the surface of the resin molding so that the surface free energy is 42 to 48 mN / m. Sometimes the aliphatic polyamide resin and the substrate can be contacted. In this case, crystallization of the aliphatic polyamide resin can be promoted from the resin surface during the processing of the aliphatic polyamide resin.

  The molding machine is not particularly limited, and examples thereof include an extrusion molding machine, an injection molding machine, a blow molding machine, a press molding machine, and a roll molding machine.

  The aliphatic polyamide resin used in the present invention includes an inorganic crystal nucleating agent, an organic crystal nucleating agent, a mold release agent, a phenolic antioxidant, a phosphorus antioxidant, a thioether antioxidant, if necessary. It is preferable to stabilize by adding an ultraviolet absorber, hindered amine light stabilizer, flame retardant, heavy metal deactivator, hydrotalcite, antistatic agent, metal soap, pigment, dye or the like.

  Examples of the inorganic crystal nucleating agent include talc, wollastonite, calcium carbonate, kaolin, calcined kaolin, silica, zeolite, boron nitride, alumina, magnesia, graphite, mica and the like. Among these, talc, kaolin, and calcined kaolin can be preferably used. These crystal nucleating agents may be those that have been surface-treated with an aminosilane coupling agent, an epoxysilane coupling agent, or the like. As the inorganic crystal nucleating agent, those having an average particle diameter in the range of 0.5 to 10 μm are usually selected.

  Examples of the organic crystal nucleating agent include polyamide, polyethylene terephthalate, polyethylene, polypropylene, rosin acid metal salt, and phosphate ester metal salt. The amount of the inorganic crystal nucleating agent or the organic crystal nucleating agent is preferably in the range of 0.01 to 3 parts by weight with respect to 100 parts by weight of the aliphatic polyamide resin. When the blending amount of these crystal nucleating agents is less than 0.01 parts by weight, the cooling and solidifying time cannot be shortened, so that the high cycle property at the time of injection molding is lowered and mass productivity may be lowered. Moreover, when the compounding quantity of these crystal nucleating agents exceeds 3 weight part, the bending-proof property at the time of low temperature will fall.

  Examples of the mold release agent include sodium montanate, potassium montanate, calcium montanate, and magnesium montanate.

  Examples of the phenolic antioxidant include 2,6-ditert-butyl-p-cresol, 2,6-diphenyl-4-octadecyloxyphenol, distearyl (3,5-ditert-butyl-4). -Hydroxybenzyl) phosphonate, 1,6-hexamethylenebis [(3,5-ditert-butyl-4-hydroxyphenyl) propionic acid amide], 4,4'-thiobis (6-tert-butyl-m-cresol ), 2,2′-methylenebis (4-methyl-6-tert-butylphenol), 2,2′-methylenebis (4-ethyl-6-tert-butylphenol), 4,4′-butylidenebis (6-tert-butyl) -M-cresol), 2,2'-ethylidenebis (4,6-ditert-butylphenol), 2,2'-ethylidenebis (4-secondarybutyl-6-tert-butylphenol) Nol), 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-tris (2,6-dimethyl-3-hydroxy-4-tertiary) Butylbenzyl) isocyanurate, 1,3,5-tris (3,5-ditert-butyl-4-hydroxybenzyl) isocyanurate, 1,3,5-tris (3,5-ditert-butyl-4- Hydroxybenzyl) -2,4,6-trimethylbenzene, 2-tert-butyl-4-methyl-6- (2-acryloyloxy-3-tert-butyl-5-methylbenzyl) phenol, stearyl (3,5- Ditertiarybutyl-4-hydroxyphenyl) propionate, tetrakis [methyl 3- (3,5-ditertiarybutyl-4-hydroxyphenyl) propionate] methane, thiodiethyleneglycol Bis [(3,5-ditert-butyl-4-hydroxyphenyl) propionate], 1,6-hexamethylenebis [(3,5-ditert-butyl-4-hydroxyphenyl) propionate], bis [3 3-bis (4-hydroxy-3-tert-butylphenyl) butyric acid] glycol ester, bis [2-tert-butyl-4-methyl-6- (2-hydroxy-3-tert-butyl-5-methyl) Benzyl) phenyl] terephthalate, 1,3,5-tris [(3,5-ditert-butyl-4-hydroxyphenyl) propionyloxyethyl] isocyanurate, 3,9-bis [1,1-dimethyl-2- {(3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} ethyl] -2,4,8,10-tetraoxaspiro [5,5] Ndecane, triethylene glycol bis [(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate] and the like, preferably 0.001 to 10 parts by weight with respect to 100 parts by weight of the aliphatic polyamide resin. More preferably, 0.05 to 5 parts by weight are used.

  Examples of the phosphorus antioxidant include trisnonylphenyl phosphite, tris [2-tert-butyl-4- (3-tert-butyl-4-hydroxy-5-methylphenylthio) -5-methylphenyl]. Phosphite, tridecyl phosphite, octyl diphenyl phosphite, di (decyl) monophenyl phosphite, di (tridecyl) pentaerythritol diphosphite, di (nonylphenyl) pentaerythritol diphosphite, bis (2,4-di Tert-butylphenyl) pentaerythritol diphosphite, bis (2,6-ditert-butyl-4-methylphenyl) pentaerythritol diphosphite, bis (2,4,6-tritert-butylphenyl) pentaerythritol diphosphite Phosphite, bis (2,4-dicumylphenyl) pen Erythritol diphosphite, tetra (tridecyl) isopropylidene diphenol diphosphite, tetra (tridecyl) -4,4′-n-butylidenebis (2-tert-butyl-5-methylphenol) diphosphite, hexa (tridecyl) -1 , 1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane triphosphite, tetrakis (2,4-ditert-butylphenyl) biphenylene diphosphonite, 9,10-dihydro-9 -Oxa-10-phosphaphenanthrene-10-oxide, 2,2'-methylenebis (4,6-tert-butylphenyl) -2-ethylhexyl phosphite, 2,2'-methylenebis (4,6- Tributylphenyl) -octadecyl phosphite, 2,2′-ethylidenebis (4 6-ditert-butylphenyl) fluorophosphite, tris (2-[(2,4,8,10-tetrakis tert-butyldibenzo [d, f] [1,3,2] dioxaphosphine-6 -Yl) oxy] ethyl) amine, phosphite of 2-ethyl-2-butylpropylene glycol and 2,4,6-tritert-butylphenol, and the like.

  Examples of the thioether-based antioxidant include dialkylthiodipropionates such as dilauryl thiodipropionate, dimyristyl thiodipropionate, and distearyl thiodipropionate, and pentaerythritol tetra (β-alkylmercaptopropionate esters). Is mentioned.

  Examples of the ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, and 5,5′-methylenebis (2-hydroxy-4-methoxybenzophenone). 2-hydroxybenzophenones, such as 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-ditert-butylphenyl) -5-chloro Benzotriazole, 2- (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) -5-chlorobenzotriazole, 2- (2′-hydroxy-5′-tert. Octylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-dicumylphenyl) benzotriazole, 2 2- (2'-methylenebis (4-tert-octyl-6- (benzotriazolyl) phenol), 2- (2'-hydroxy-3'-tert-butyl-5'-carboxyphenyl) benzotriazole and other 2- ( 2'-hydroxyphenyl) benzotriazoles; phenyl salicylate, resorcinol monobenzoate, 2,4-ditert-butylphenyl-3,5-ditert-butyl-4-hydroxybenzoate, 2,4-ditert-amylphenyl Benzoates such as 3,5-ditert-butyl-4-hydroxybenzoate, hexadecyl-3,5-ditert-butyl-4-hydroxybenzoate; 2-ethyl-2′-ethoxyoxanilide, 2-ethoxy Substituted oxanilides such as -4′-dodecyloxanilide; ethyl-α-cyano-β, β-diphenyl Cyanoacrylates such as acrylate and methyl-2-cyano-3-methyl-3- (p-methoxyphenyl) acrylate; 2- (2-hydroxy-4-octoxyphenyl) -4,6-bis (2,4 -Di-tert-butylphenyl) -s-triazine, 2- (2-hydroxy-4-methoxyphenyl) -4,6-diphenyl-s-triazine, 2- (2-hydroxy-4-propoxy-5-methylphenyl) And triaryltriazines such as -4,6-bis (2,4-ditert-butylphenyl) -s-triazine.

  Examples of the hindered amine light stabilizer include 2,2,6,6-tetramethyl-4-piperidyl stearate, 1,2,2,6,6-pentamethyl-4-piperidyl stearate, 2,2, 6,6-tetramethyl-4-piperidylbenzoate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, tetrakis (2,2,6,6-tetramethyl-4-piperidyl) -1 , 2,3,4-butanetetracarboxylate, tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate, bis (2,2, 6,6-tetramethyl-4-piperidyl) di (tridecyl) -1,2,3,4-butanetetracarboxylate, bis (1,2,2,6,6-pentamethyl-4 Piperidyl) .di (tridecyl) -1,2,3,4-butanetetracarboxylate, bis (1,2,2,4,4-pentamethyl-4-piperidyl) -2-butyl-2- (3,5 -Di-tert-butyl-4-hydroxybenzyl) malonate, 1- (2-hydroxyethyl) -2,2,6,6-tetramethyl-4-piperidinol / diethyl succinate polycondensate, 1,6- Bis (2,2,6,6-tetramethyl-4-piperidylamino) hexane / 2,4-dichloro-6-morpholino-s-triazine polycondensate, 1,6-bis (2,2,6,6 -Tetramethyl-4-piperidylamino) hexane / 2,4-dichloro-6-tert-octylamino-s-triazine polycondensate, 1,5,8,12-tetrakis [2,4-bis (N-butyl) -N- (2,2, , 6-tetramethyl-4-piperidyl) amino) -s-triazin-6-yl] -1,5,8,12-tetraazadodecane, 1,5,8,12-tetrakis [2,4-bis ( N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino) -s-triazin-6-yl] -1,5,8-12-tetraazadodecane, 1,6 , 11-tris [2,4-bis (N-butyl-N- (2,2,6,6-tetramethyl-4-piperidyl) amino) -s-triazin-6-yl] aminoundecane, 1,6 , 11-tris [2,4-bis (N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino) -s-triazin-6-yl] aminoundecane Compounds.

  Examples of the heavy metal deactivator include N, N′-diphenyloxamide, N, N′-bis (salicyloyl) hydrazine, N, N′-bis (3,5-ditert-butyl-4-hydroxyphenylpropionyl). ) Hydrazine, 3-salicyloylamino-1,2,4-triazole, bis (benzylidene) oxalyl dihydrazide, isophthaloyl dihydrazide, sebacoyl bisphenyl hydrazide, N, N′-diacetyladipoyl dihydrazide, N, N Examples include '-bis (salicyloyl) oxalyl dihydrazide, N, N'-bis (salicyloyl) thiopropionyl dihydrazide, and the like.

  Examples of the present invention are listed below together with comparative examples, but the present invention is not limited to the following examples.

Example 1
Hydrogen peroxide (manufactured by Santoku Chemical Co., Ltd .: reagent special grade) 30 ml and concentrated sulfuric acid (manufactured by Nacalai Tesque Co., Ltd .: reagent special grade) 70 ml were added to a 1 liter beaker, and the substrate (described in Table 1) was immersed therein. Heat to 100 ° C. and hold for 2 hours. After cooling, the substrate was taken out, washed with pure water, and then vacuum dried at room temperature for 3 hours to obtain a hydrophilized substrate.

Chemical Vapor Adsorption Method The above-mentioned hydrophilized base material was irradiated with ultraviolet light having a wavelength of 172 nm for 10 minutes using a vacuum ultraviolet light irradiation device (Vacuum Ultraviolet, VUV, manufactured by USHIO INC.). Thereafter, the mixture was sealed in a Teflon / stainless steel pressure vessel together with an organosilane compound (described in Table 1) in a nitrogen atmosphere and reacted at 100 ° C. for 2 hours. After the reaction, the substrate was washed in Example 1-2 and Comparative Examples 1-1 to 1-3 in Table 1 with dry toluene, and Examples 1-1 and 1-3 were washed with dry ethanol, and then naturally dried. .
The contact angle of the obtained base material with water and diiodomethane (manufactured by Wako Pure Chemical Industries, Ltd.) was measured with a contact angle measuring device (manufactured by KRUS), and surface free energy (mN / m) was obtained by the Owens formula. It was. The results are shown in Table 1.

  0.75 g of polyamide-6 (CM1021: manufactured by Toray Industries, Inc.) was added to 1,1,1,3,3,3-3- base materials having different surface free energies obtained as described above (described in Table 1). Hexafluoro-2-propanol (manufactured by Kanto Chemical Co., Inc .: reagent grade) dissolved in 29.25 g and dropped, and a polyamide-6 thin film with a thickness of 100 to 150 nm is prepared by spin coating (1 minute at 2000 rpm) did. This was dried at 120 ° C. under reduced pressure for 4 hours to obtain a test piece.

  The obtained test piece was analyzed with a polarizing microscope having a heating stage under a nitrogen stream. As crystallization conditions, heating to 250 ° C. and holding for 3 minutes to melt polyamide-6, cooling at 5 ° C./minute, measuring the temperature at which formation of crystals is confirmed three times, and comparing the average values Crystallization performance was evaluated. The results are shown in Table 1.

  As the organosilane compound, n-octyltrimethoxysilane: manufactured by Chisso Corporation, 3-aminopropyltrimethoxysilane: manufactured by Chisso Corporation, 3- (2-aminoethylamino) propyltrimethoxysilane: Chisso Corporation ), 3-mercaptopropyltrimethoxysilane: manufactured by Chisso, 3,3,3-trifluoropropyltrimethoxysilane: manufactured by GELEST INC, and heptadecafluorodecyltrimethoxysilane: manufactured by Shin-Etsu Chemical Co., Ltd. were used.

Example 2
The surface free energy of the base material (described in Table 2) obtained by surface treatment in the same manner as in Example 1 was measured, and polyamide-6 (CM1061: manufactured by Toray Industries, Inc.) was applied in the same manner as in Example 1. The crystallinity of the obtained test piece was analyzed with a polarizing microscope having a heating stage under a nitrogen stream. As crystallization conditions, the temperature was increased to 250 ° C. and held for 3 minutes to melt polyamide-6, the temperature was decreased to 200 ° C. at 20 ° C./min, and the time until crystal formation was confirmed at the same temperature was measured. The results are shown in Table 2.

When surface free energy was measured for aluminum and SUS304, which are the materials of ordinary molding machines, aluminum was 35 mN / m and SUS304 was 36 mN / m, which is preferable for promoting the crystallization of the polyamide of the present invention. Energy is not achieved on the surface of conventional processing machines.

Claims (3)

  A method for promoting crystallization of a polyamide resin, comprising bringing an aliphatic polyamide resin into contact with a substrate having a surface free energy of 42 to 48 mN / m.   The method for accelerating crystallization of a polyamide resin according to claim 1, wherein the base material is a resin molding surface of a molding machine. A polyamide molded article produced by using the method for promoting crystallization of a polyamide resin according to claim 1.