JP2007138005A - Flame-retardant coated molded product composed of polyamide resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To impart flame retardance to a coated molded product obtained by coating a molded product composed of a polyamide resin composition which is flame retarded with a melamine cyanurate with an acrylic urethane coating. <P>SOLUTION: The flame-retardant coated molded product is obtained by coating (A) the molded product molded from the polyamide resin composition which is flame retarded with the melamine cyanurate with the coating prepared by compounding (B-1) 100 pts.wt. of an acrylic urethane coating with (B-2) 1-8 pts.wt. of the melamine cyanurate. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a polyamide resin composition coated molded article having excellent flame retardancy.

  Conventionally, polyamide resins are excellent in mechanical properties such as tensile and bending strength and elastic modulus, and also have good heat resistance, chemical resistance, and flame resistance. Widely used in parts and machine parts. In recent years, mainly in the field of electrical and electronic parts, the demand for flame retardant plastic materials has increased, and various flame retardant technologies have been invented.

For example, Patent Document 1 proposes a resin composition containing melamine cyanurate, which is a reaction product of melamine and cyanuric acid, and conforms to UL94-V0 in non-reinforced flame retardant polyamide. However, when coating is performed to improve the appearance design, the flame retarding mechanism is hindered, and there is a problem that a flame retardant molded product cannot be obtained. Patent Document 2 proposes a paint in which melamine cyanurate is blended in the clear layer. However, blending into the clear layer alone does not provide sufficient flame retardancy, and melamine cyanurate is white. Therefore, flame retarding is impossible with a blending amount that maintains the transparency of the clear layer. Patent Document 3 proposes a technique for blending ammonium polyphosphate into a paint, but the flame retardant mechanism is different from the polyamide resin composition flame-retardant with melamine cyanurate, which is generally used for non-reinforced polyamide, There was a problem that sufficient flame retardancy could not be obtained. Patent Document 4 proposes blending a flame retardant with a conductive paint, but the metal powder that exhibits conductivity acts as a candle wick at the time of combustion, impairing flame retardancy and conducting. However, there was a problem that sufficient coating film adhesion could not be secured with a blending amount at a level to maintain the property and flame retardancy.
Japanese Patent Publication No. 58-25379 (Claim 1) JP-A-3-28277 (Claim 1) JP-A-8-253710 (Claim 1) JP 2003-258480 A (Claim 1)

  This invention makes it a subject to provide a flame retardance to the coating molded product which coated the molded product which consists of a flame retardant polyamide resin composition containing a melamine cyanurate.

  Therefore, as a result of intensive studies to solve the above problems, the present inventors have applied a molded article comprising a flame-retardant polyamide resin composition containing melamine cyanurate with an acrylic urethane-based paint blended with melamine cyanurate. The inventors have found that the above object can be achieved and have reached the present invention.

That is, the present invention
(1) (A) A molded article comprising a flame retardant polyamide resin composition containing melamine cyanurate, (B-1) melamine cyanurate 1 to 100 parts by weight of (B-1) acrylic urethane paint A flame-retardant paint molded product painted with 8 parts by weight of paint,
(2) (B-2) Melamine cyanurate 1 with respect to 100 parts by weight of (B-1) acrylic urethane-based paint on a molded product molded from a flame retardant polyamide resin composition containing (A) melamine cyanurate A method for producing a flame-retardant coated molded article, which is coated with a paint comprising 8 parts by weight,
Consists of.

  The flame-retardant coated molded article of the present invention is excellent in flame retardancy and paint adhesion, and is a mobile phone, PHS, LCD TV, plasma display, PDA, small TV, radio, notebook computer, personal computer, mouse, printer, scanner, memory Equipment, PC peripherals, VCR, DVD deck, CD deck, MD deck, DAT deck, amplifier, cassette deck, portable CD player, portable MD player, camera, digital camera, binoculars, microscope, telescope, clock, home phone , Office phones, toys, medical equipment, rice cooker parts, microwave oven parts, acoustic parts, lighting parts, refrigerator parts, air conditioner parts, facsimile parts, copy machine parts, building material parts, furniture parts, electric wire coating, electric wire sheaths It is particularly excellent as a molded product for painting such as tubes. .

  Embodiments of the present invention will be described below. In the present invention, “weight” means “mass”.

  The polyamide resin used in the polyamide resin composition flame-retarded with (A) melamine cyanurate in the present invention is a polyamide mainly composed of amino acid, lactam or diamine and dicarboxylic acid. Representative examples of the main constituents include amino acids such as 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid and paraaminomethylbenzoic acid, lactams such as ε-caprolactam and ω-laurolactam, and tetramethylenediamine. , Hexamethylenediamine, 1,5-pentanediamine, 2-methylpentamethylenediamine, nonamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4- / 2,4,4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine, metaxylenediamine, paraxylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1-amino-3-aminomethyl-3,5 5-trimethylsick Fats such as sun, bis (4-aminocyclohexyl) methane, bis (3-methyl-4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane, bis (aminopropyl) piperazine, aminoethylpiperazine , Cycloaliphatic, aromatic diamines, and adipic acid, peric acid, azelaic acid, sebacic acid, dodecanedioic acid, terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid Examples include aliphatic, alicyclic, and aromatic dicarboxylic acids such as acid, 5-sodium sulfoisophthalic acid, 2,6-naphthalenedicarboxylic acid, hexahydroterephthalic acid, and hexahydroisophthalic acid. Polyamide homopolymers or copolymers derived from the raw materials of Each can be used alone or in the form of mixtures.

  In the present invention, a particularly useful polyamide resin is a polyamide resin having a melting point of 150 ° C. or more and excellent in heat resistance and strength. Specific examples include polycaproamide (polyamide 6), polyhexamethylene adipamide. (Polyamide 66), polypentamethylene adipamide (polyamide 56), polytetramethylene adipamide (polyamide 46), polyhexamethylene sebamide (polyamide 610), polyhexamethylene dodecamide (polyamide 612), polyundecane Amide (polyamide 11), polydodecanamide (polyamide 12), polycaproamide / polyhexamethylene adipamide copolymer (polyamide 6/66), polycaproamide / polyhexamethylene terephthalamide copolymer (polyamide 6 / 6T), polyhexamethy Adipamide / polyhexamethylene isophthalamide copolymer (polyamide 66 / 6I), polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (polyamide 6T / 6I), polyhexamethylene terephthalamide / polydodecanamide copolymer (polyamide 6T / 12) , Polyhexamethylene adipamide / polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (polyamide 66 / 6T / 6I), polyxylylene adipamide (polyamide XD6), polyhexamethylene terephthalamide / poly-2- Mention may be made of methylpentamethylene terephthalamide copolymers (polyamide 6T / M5T) and copolymers having polynomethylene terephthalamide phthalamide units. Can, furthermore also practically preferable to use a mixture in accordance with the required characteristics such as these polyamide resins moldability, compatibility. Particularly preferred polyamide resins include polyamide 6, polyamide 66, polyamide 6/66 copolymer, and the like.

  The degree of polymerization of these polyamide resins is not particularly limited, but the relative viscosity measured at 25 ° C. in a 98% concentrated sulfuric acid solution having a sample concentration of 0.01 g / ml is in the range of 1.5 to 7.0. More preferably, it is 1.5-6.0, Most preferably, it is the range of 2.0-5.0.

  Although the melamine cyanurate used in this invention is normally obtained by making a melamine and cyanuric acid (or isocyanuric acid) react in water by equimolar ratio, it is not necessarily limited to this. The melamine cyanurate is preferably pure, but may contain a small amount of unreacted melamine or cyanuric acid (or isocyanuric acid). The average particle size is preferably finer in terms of obtaining smoothness of the paint and increasing the flame retardancy efficiency.

  The flame retardant polyamide resin composition containing (A) melamine cyanurate of the present invention may contain other components to the extent that flame retardancy is not impaired. Specific examples include copper-based heat stabilizers, hindered phenol-based, phosphorus-based and sulfur-based antioxidants, heat stabilizers, UV absorbers, lubricants, mold release agents, antistatic agents, and dyes and pigments. One or more usual additives such as colorants can be added. However, when the reinforcing material is included at the same time, the polyamide resin composition containing melamine cyanurate cannot be made flame-retardant because of the effect of the candle core, which is not preferable.

  The flame retardant polyamide resin composition containing (A) melamine cyanurate used in the present invention is molded by an arbitrary method, and specifically, molded by a method such as injection molding, extrusion molding or blow molding.

  The (B-1) acrylic urethane-based paint, which is a paint used for the flame-retardant paint molded article of the present invention, is a heat-reactive paint, and from the difference in molecular weight and handling, it is a one-liquid oil-based paint. There are two-component oil-based systems and water-based systems, but there are no particular restrictions on the type. From the viewpoint of coating strength, a two-component oily system is preferred.

  The paint used for the flame-retardant paint molded article of the present invention must contain 1 to 8 parts by weight of (B-2) melamine cyanurate with respect to 100 parts by weight of (B-1) acrylic urethane paint. . If it is less than 1 part by weight, sufficient flame retardancy cannot be obtained, and if it is 8 parts by weight or more, sufficient coating strength cannot be obtained. 2-6 weight part is more preferable from the balance of a flame retardance and coating-film adhesion strength.

  In general, it is known that when melamine cyanurate is contained in a polyamide resin, they react during combustion, and the polyamide resin is reduced in molecular weight to extinguish the fire. It is known to inhibit. On the other hand, acrylamine-based paints cannot provide the same flame retardant mechanism with melamine cyanurate because of its chemical composition. However, in the present invention, the flame retardant mechanism between the polyamide resin and the paint due to the synergistic effect of the nitrogen oxide generated from the melamine cyanurate present in the paint having a thin film thickness upon combustion and the chemical reaction acting on the polyamide resin surface layer. It is presumed that a coated molded article maintaining the high flame retardancy of the flame retardant polyamide resin composition containing melamine cyanurate was obtained despite the difference in the above.

  There is no particular limitation on the method of applying the acrylic urethane-based paint blended with melamine cyanurate to the molded article molded with the polyamide resin composition flame-retardant with melamine cyanurate used in the present invention, and it is matched to the shape. Can be painted by spraying or squeaking.

  The flame-retardant coated molded article of the present invention can achieve both extremely high flame retardance and coating film adhesion, which could not be achieved in the past, and is particularly suitable for exterior parts and wire coating.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further in detail, this invention is not limited by these. Measurement methods used in Examples and Comparative Examples are shown below.

(1) Evaluation of flame retardancy It measured according to the following standard methods.
Painted product obtained by injection molding: UL94
Painted product of wire covering product: ISO6722

(2) Coating film strength evaluation It evaluated according to the following method.
-Molded product obtained by injection molding As the adhesion strength of the paint by painting, the molded product obtained by injection molding of 80mm x 80mm x 3mm is coated, and left at room temperature for 24 hours after painting, to JIS K5400 A cross-cut tape test was carried out in the same manner. Those having an evaluation score of 10 are excellent, and the smaller the evaluation score is, the lower the coating adhesion is.
-Wire-covered product The prepared coated wire was wound around a 10 mmφ stainless steel cylinder, and the process of holding and stretching for 5 minutes was repeated 10 times, and the presence or absence of cracks on the painted surface was observed with a microscope.
Judgment criteria are as follows.
○: No crack is observed.
Δ: Fine cracks are observed.
X: A big crack generate | occur | produces.

Reference Example 1 Production of polyamide resin composition flame-retardant with melamine cyanurate The polyamide resin composition flame-retardant with melamine cyanurate used in Examples and Comparative Examples was prepared by the following method.

  6 parts by weight of melamine cyanurate (manufactured by Ciba Specialty Chemicals: trade name MC15) per 100 parts by weight of polyamide 6 resin (trade name: Amilan CM1017, manufactured by Toray Industries, Inc.) (Toshiba Machine Co., Ltd .: TEM58) is used to melt and knead polyamide 6 resin and melamine cyanurate with top feed (original feed) under the conditions of a cylinder set temperature of 270 ° C. and a screw speed of 200 rpm, and form a strand. After cooling with a cold bath, it was granulated with a cutter to obtain pellets.

Reference Example 2 Blending Method of Melamine Cyanurate into Acrylic Urethane Paints Acrylic urethane paint blended with yellow pigment (Musashi Paint Co., Ltd .: trade name Nitec 79) and the amount of melamine cyanurate shown in the following examples and comparative examples (Ciba Specialty Chemicals Co., Ltd. product name: MC15) was put into a mixer and mixed for 5 minutes.

Reference Example 3 Preparation of Molded Product A test piece for evaluating the coating film strength of a molded product was obtained by using an injection molding machine PS60 manufactured by Nissei Plastic Industry Co., Ltd., cylinder temperature 260 ° C., mold surface temperature 80 ° C., injection / cooling = 10. An 80 × 80 × 3 (mm) mirror-polished square plate (film gate) was injection molded under the conditions of / 10 seconds.

Reference Example 4 Preparation of Covered Electric Wire A polyamide resin composition flame-retarded with melamine cyanurate was introduced into a 30 mmφ electric wire coating apparatus manufactured by Seisaku Seisakusho Co., Ltd. A 5 mmφ copper wire was covered with 0.2 mm to prepare a covered electric wire.

Reference Example 5 Coating Method of Molded Product Obtained by Injection Molding Mixture of 9: 9 as a curing agent with acrylic urethane paint blended with melamine cyanurate, applied to molded product, 30 minutes at 80 ° C Dried to obtain a painted molded product.

Reference example 6 Coating method for wire-covered products Mixing acrylic urethane-based paint blended with melamine cyanurate in a ratio of 9: 1 as a curing agent, applying to the wire coating, drying at 80 ° C for 30 minutes, and coating the coated wire Got.

Example 1
A polyamide resin composition flame-retarded with (A) melamine cyanurate prepared by the method shown in Reference Example 1 was formed into a molded product and a covered electric wire by the methods shown in UL94 and Reference Examples 3 and 4, The acrylic urethane-based paint blended with the melamine cyanurate prepared by the method shown in Reference Example 2 at the weight ratio shown in 1 was applied by the methods shown in Reference Examples 5 and 6, and various properties were measured by the above measuring methods. The results are shown in Table 1.

Examples 2, 3, 4
Various characteristics were measured in the same manner as in Example 1 except that the amount of melamine cyanurate to be blended in the acrylic urethane coating was a part by weight shown in Table 1. The results are shown in Table 1.

Comparative Examples 1 and 2
Various characteristics were measured in the same manner as in Example 1 except that the amount of melamine cyanurate to be blended in the acrylic urethane coating was a part by weight shown in Table 1. The results are shown in Table 1.

  From Examples 1 to 3 and Comparative Examples 1 and 2, a polyamide resin composition flame-retarded with melamine cyanurate is coated with an acrylic urethane-based paint blended with melamine cyanurate, thereby providing flame-retardant coating molding. It was confirmed that the product was obtained. In addition, it was confirmed that the molded product and the covered electric wire can obtain high coating adhesion which is important as a characteristic of the product to be painted.

Claims (2)

(A) A molded article comprising a flame-retardant polyamide resin composition containing melamine cyanurate, (B-2) 1-8 parts by weight of melamine cyanurate with respect to 100 parts by weight of (A-1) acrylic urethane-based paint A flame-retardant paint molded product painted with a paint blended with. (A) A molded article comprising a flame-retardant polyamide resin composition containing melamine cyanurate, (B-2) 1-8 parts by weight of melamine cyanurate with respect to 100 parts by weight of (A-1) acrylic urethane-based paint A method of manufacturing a flame-retardant paint molded product, which is painted with a paint comprising