JP2011026537A - Thermoplastic resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition having an excellent appearance on which decorations are formed. <P>SOLUTION: The thermoplastic resin composition comprises a thermoplastic resin with a refractivity of 1.51-1.58, and a metal luster powder on which a metal oxide with a thickness of ≥40 nm and ≤130 nm is coated on a glass flake in which an average particle diameter is ≥50 μm and ≤600 μm, and the ratio of an average particle diameter and an average thickness (average particle diameter/average thickness) is ≥5 and ≤60. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a transparent resin having decorating properties, and more particularly, to a thermoplastic resin composition that has been decorated with metallic luster.

Conventionally, resin products such as home appliances, office equipment products, automobile exteriors, cosmetic containers, and the like have been colored in various ways in order to impart design properties.
In such coloring, decoration such as a lame tone or a metallic tone may be performed for the purpose of giving a high-class feeling or differentiating from other designs.
As a material for decorating such as a lame tone or a metallic tone, a material obtained by adding metallic luster particles to a thermoplastic resin is known.
For example, a thermoplastic resin composition has been proposed which has a metallic decorative effect by adding polyhedral particles having a specific average particle size having a metallic luster and also improves the weld appearance ( For example, see Patent Document 1.)

  Further, a thermoplastic resin composition having a good metallic appearance, in which a specific thermoplastic resin contains particles having metallic luster having a specific average particle diameter has been proposed (see, for example, Patent Document 2). .

  Furthermore, a thermoplastic resin composition having a metallic luster and a metallic appearance in which a specific pigment and metallic luster particles are contained in a specific thermoplastic resin composition has been proposed (for example, see Patent Document 3).

  Furthermore, proposals have been made for a thermoplastic resin composition having excellent luster by adding metallic luster particles made of flaky glass coated with a metal oxide to a transparent resin (for example, Patent Documents 4 and 5). reference.).

JP-A-8-120115 Japanese Patent Laid-Open No. 9-194631 JP 2003-313393 A JP 2001-226601 A JP 2006-316228 A

  However, in Patent Documents 1 to 3, since metal, metal oxide, and inorganic and organic particles coated with metal are used as metallic luster particles, when light is transmitted through a resin composition containing these, In addition, there is a problem that the metallic luster particles look like black spots and a desired aesthetic appearance cannot be obtained.

  In addition, in the thermoplastic resin compositions disclosed in Patent Documents 4 and 5, there is no problem that the metallic luster particles look like black spots when transmitting light, but cloudy or metallic luster particles There is a problem that alignment spots occur.

  Therefore, in the present invention, in view of the above-mentioned problems of the prior art, even if light is transmitted, it does not look like a black spot, and it has an excellent aesthetic that effectively reduces the occurrence of cloudiness and alignment spots. An object of the present invention is to provide a decorated thermoplastic resin composition.

As a result of intensive studies, the present inventors have found that the above-mentioned problems can be solved by including specific metallic luster particles in a thermoplastic resin having a refractive index in a specific range, thereby completing the present invention. It came.
That is, the present invention is as follows.

[1]
A thermoplastic resin having a refractive index of 1.51 to 1.58;
Flake glass having an average particle diameter of 50 μm to 600 μm and a ratio of average particle diameter to average thickness (average particle diameter / average thickness) of 5 to 60 is coated with a metal oxide with a thickness of 40 nm to 130 nm. Metallic glossy particles,
A thermoplastic resin composition.

[2]
The thermoplastic resin composition according to [1], wherein the addition amount of the metallic luster particles is 0.01 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the thermoplastic resin.

[3]
[1] or [2], wherein the thermoplastic resin is a copolymer of an aromatic vinyl monomer and one or more monomers copolymerizable with the aromatic vinyl monomer. The thermoplastic resin composition described in 1.

[4]
The thermoplastic resin composition according to any one of [1] to [3], further including 0.001 to 0.1 parts by mass of a dye with respect to 100 parts by mass of the thermoplastic resin.

[5]
A molded article obtained by molding the thermoplastic resin composition according to any one of [1] to [4].

  ADVANTAGE OF THE INVENTION According to this invention, the decorative transparent resin which has a metallic luster and has the outstanding beauty | look, and its molded object are obtained.

  Hereinafter, although the form (henceforth "this embodiment") for implementing this invention is demonstrated, this invention is not limited to the example shown below.

[Thermoplastic resin composition]
The thermoplastic resin composition of the present embodiment comprises a thermoplastic resin having a refractive index of 1.51 to 1.58 and a ratio of an average particle diameter to an average thickness (average particle diameter / It is a thermoplastic resin composition containing metallic luster particles in which a metal oxide is coated with a thickness of 40 nm to 130 nm on a flaky glass having an average thickness of 5 to 60.

(Thermoplastic resin)
The thermoplastic resin constituting the thermoplastic resin composition of the present embodiment is not particularly limited as long as it has a refractive index in the range of 1.51 to 1.58.
The refractive index can be measured by a measuring method shown in Examples described later using a predetermined refractometer.
Examples of the thermoplastic resin include aromatic vinyl resins, norbornene resins, and mixtures of aromatic vinyl resins and acrylic resins.
The aromatic vinyl resin includes not only a polymer using a styrene monomer but also a copolymer resin of a styrene monomer and a vinyl cyanide monomer and / or an acrylic monomer. Furthermore, a copolymer resin obtained by copolymerizing other copolymerizable monomers, a resin obtained by graft polymerization with a rubbery polymer, and the like are also included.

The styrenic monomer is not particularly limited, and examples thereof include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, o-ethylstyrene, p-ethylstyrene, and pt-butyl. Examples include styrene. Particularly preferred are styrene and α-methylstyrene.
These may be used alone or in combination of two or more.

The vinyl cyanide monomer is not particularly limited, and examples thereof include acrylonitrile, methacrylonitrile, ethacrylonitrile and the like, and acrylonitrile is particularly preferable.
These may be used alone or in combination of two or more.

  The acrylic monomer is not particularly limited. For example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, T-butyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, chloromethyl (meth) acrylate, 2-chloroethyl (meth) acrylate, 2-hydroxy (meth) acrylate Ethyl, 3-hydroxypropyl (meth) acrylate, 2,3,4,5,6-pentahydroxyhexyl (meth) acrylate, 2,3,4,5-tetrahydroxypentyl (meth) acrylate, etc. Among them, methyl (meth) acrylate and n-butyl acrylate are particularly preferable.

  The other copolymerizable monomer is not particularly limited, and examples thereof include N-phenylmaleimide and maleic anhydride.

The rubbery polymer is not particularly limited, and any of diene rubber, acrylic rubber, ethylene rubber, and the like can be used.
For example, polybutadiene, styrene-butadiene copolymer, styrene-butadiene block copolymer, acrylonitrile-butadiene copolymer, butyl acrylate-butadiene copolymer, polyisoprene, butadiene-methyl methacrylate copolymer, acrylic acid Butyl-methyl methacrylate copolymer, butadiene-ethyl acrylate copolymer, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, ethylene-isoprene copolymer, ethylene-methyl acrylate copolymer Etc. In particular, polybutadiene, styrene-butadiene copolymer, styrene-butadiene block copolymer, and acrylonitrile-butadiene copolymer are preferable from the viewpoint of obtaining sufficient impact resistance in the thermoplastic resin composition of the present embodiment.

Examples of the norbornene-based resin include, for example, a ring-opening polymer of a norbornene-based monomer, a ring-opening polymer of a norbornene-based monomer and another monomer, a hydride thereof, and a norbornene-based monomer. Examples thereof include addition polymers or addition polymers of norbornene monomers and other monomers, or hydrides thereof.
Examples of the norbornene-based monomer include norbornene, dicyclopentadiene, methanotetrahydrofluorene, and tetracyclododecene.
Examples of other monomers capable of ring-opening copolymerization with norbornene-based monomers include cyclohexene, cycloheptene, cyclooctene, cyclohexadiene, and cycloheptadiene.
Examples of other monomers capable of addition copolymerization with norbornene monomers include α-olefins such as ethylene, propylene, and 1-butene, and cycloolefins such as cyclobutene, cyclopentene, cyclohexene, and cyclooctene. .

The aromatic vinyl resin used in the mixture of the aromatic vinyl resin and the acrylic resin is not particularly limited, and various styrene resins described above can be used, and in particular, styrene / acrylonitrile copolymer. Resins are preferred.
Examples of the acrylic resin used in the mixture of the aromatic vinyl resin and the acrylic resin include those obtained by copolymerizing a methyl methacrylate monomer and an unsaturated carboxylic acid alkyl ester monomer. .
Other examples of unsaturated carboxylic acid alkyl ester monomers include methyl acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, and (meth) acrylic acid. t-butyl, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, chloromethyl (meth) acrylate, 2-chloroethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, (meth) Unsaturated alkyl alkyls such as 3-hydroxypropyl acrylate, 2,3,4,5,6-pentahydroxyhexyl (meth) acrylate and 2,3,4,5-tetrahydroxypentyl (meth) acrylate An ester monomer is mentioned. In particular, methyl acrylate and n-butyl acrylate are preferred. These may be used alone or in combination of two or more.

(Glossy metallic particles)
The metallic luster particles constituting the thermoplastic resin composition of the present embodiment have a configuration in which a metal oxide is coated on a flaky glass serving as a base material.
The flaky glass is a thin plate-like or scaly fine glass powder.
The flaky glass can be produced by a conventionally known method.
The flaky glass has an average particle diameter of 50 μm or more and 600 μm or less in order to obtain good shine in the metallic luster particles, to improve the balance of the appearance of the metallic luster particles, and to improve the overall appearance. And preferably 75 μm or more and 125 μm or less.
The average particle diameter of the flaky glass can be measured by suspending particles in an aqueous medium and using a laser diffraction method or a scattering method.
Furthermore, in the flaky glass, the ratio of the average particle diameter to the average thickness (average particle diameter / average thickness) obtains good shine in the metallic glossy particles, and effectively reduces the alignment spots of the metallic glossy particles. From a viewpoint, it shall be 5 or more and 60 or less, preferably 1 or more and 20 or less.
The average thickness of the flaky glass is observed with an electron microscope such as SEM (scanning electron microscope), for example, and the average value is obtained from the measurement result of an arbitrary portion of n = 20 or more, that is, the number of measurement samples is 20 or more. It is obtained by calculating.

Although there is no restriction | limiting in particular as a metal oxide which coat | covers the flake shaped glass mentioned above, For example, titanium dioxide and iron oxide are mentioned. In particular, titanium dioxide is preferable.
The average coating thickness of the metal oxide is 40 nm or more in order to obtain sufficient colorability in the metallic luster particles, and 130 nm or less from the viewpoint of reducing the haze (cloudiness) of the thermoplastic resin composition in the present embodiment. .
The average coating thickness of the metal oxide is obtained, for example, by observing with an electron microscope such as SEM (scanning electron microscope) and calculating the average value from the measurement result of an arbitrary portion of n = 20 or more as described above. It is done.
By controlling the average coating thickness of the metal oxide, the color of the metallic luster particles can be adjusted. Specifically, when the average coating thickness is 40 nm to 60 nm, white is obtained, when 60 nm to 80 nm is set, yellow is obtained, when 80 nm to 100 nm is set, red, and when 100 nm to 130 nm is set, blue is obtained.
In particular, when the average coating thickness of the metal oxide exceeds 80 nm, the target thermoplastic resin composition has a high haze (cloudiness) and tends to cause alignment spots, but the refractive index was specified as described above. By using a thermoplastic resin and specifying the average particle diameter / average coating thickness numerically in the metallic glossy particles, it can be effectively reduced.
The method for coating the surface of the flaky glass with a metal oxide is not particularly limited, and a known method can be applied. Examples thereof include a sputtering method, a sol-gel method, a chemical vapor deposition (CVD) method, a liquid phase extraction (LPD) method, and the like.

  The amount of the metallic luster particles added is 0.01 parts by mass or more with respect to 100 parts by mass of the above-mentioned thermoplastic resin in order to obtain sufficient brightness in the target thermoplastic resin composition, and has a practically sufficient strength. From the viewpoint of securing the amount, it is preferably 5 mass or less. More preferably, it is 0.1 to 1 part by mass.

(dye)
You may further add dye to the thermoplastic resin composition in this embodiment.
Examples of the dye include anthraquinone, perinone, azo, methine, quinophthalone, and coumarin dyes.
The addition amount of the dye is 0.001 part by mass or more with respect to 100 parts by mass of the thermoplastic resin from the viewpoint of ensuring the brightness of the metallic luster particles in the target thermoplastic resin composition, and from the viewpoint of ensuring transparency. The amount is preferably 0.1 parts by mass or less with respect to 100 parts by mass of the thermoplastic resin.

(Additive)
In the thermoplastic resin composition of the present embodiment, predetermined additives may be used as long as the transparency, rigidity, impact resistance, and cutting ability are not impaired.
Examples of additives include phosphites, hindered phenols, benzotriazoles, benzophenones, benzoates, cyanoacrylates, UV absorbers and antioxidants, higher fatty acids and acid esters, acid amides, Lubricants and plasticizers such as higher alcohols, montanic acid and salts thereof, esters thereof, half esters thereof, release agents such as stearyl alcohol, stellar amide and ethylene wax, coloring of phosphites, hypophosphites, etc. Examples thereof include antistatic agents, nucleating agents, amine-based, sulfonic acid-based, polyether-based antistatic agents, and pigments.

[Method for producing thermoplastic resin composition]
The thermoplastic resin composition of the present embodiment can be produced by a conventionally known method.
For example, it can be produced by melting and kneading the above-described constituent components using a general mixer such as an open roll, an intelligent mixer, an internal mixer, a kneader, a continuous kneader with a twin-screw rotor, and an extruder. .

[Molded body]
The molded article of the thermoplastic resin composition of the present embodiment is obtained by continuously extruding the thermoplastic resin composition with an extruder and cutting it into a desired dimension.

  Examples of the present invention and comparative examples will be specifically described below, but the present invention is not limited to the following examples.

[Material of thermoplastic resin composition]
(1) Thermoplastic resin (A)
(1-1) Styrene-acrylonitrile copolymer (A-1)
Melt flow rate value (measured according to ASTM-D1238. Conditions are 220 ° C. and 10 kg load) is 30 g / 10 min, styrene unit content is 80% by mass, acrylonitrile unit content is 20 A mass% styrene-acrylonitrile copolymer was used.
(1-2) Acrylic resin (A-2)
Melt flow rate value (measured according to ASTM-D1238. Conditions are 230 ° C., 3.8 kg load) is 2.0 g / 10 min, methyl methacrylate monomer content is 97.5 mass %, A methyl methacrylate-methyl acrylate copolymer having a methyl acrylate monomer content of 2.5 mass% was used.
(1-3) Polystyrene (A-3)
PSJ-polystyrene 685 manufactured by PS Japan Co., Ltd. was used.

(2) Metallic luster particles (B)
The following varieties in the Metashine titanium oxide coat series manufactured by Nippon Sheet Glass Co., Ltd. were used.
(2-1) Metashine MC5090RS (B-1)
(2-2) Metashine MC5090RY (B-2)
(2-3) Metashine MC5090RR (B-3)
(2-4) Metashine MC5090RB (B-4)
(2-5) Metashine MC5090RG (B-5)
(2-6) Metashine MC1040RB (B-6)
(2-7) Metashine MC1080RS (B-7)
(2-8) Meta Shine MC1080RB (B-8)
(2-9) The flaky glass constituting the (B-1) is changed to an average particle diameter of 500 μm and an average thickness of 10 μm (B-9)

(3) Dye (C)
A mixture of Plast Red 8350 manufactured by Arimoto Chemical Industry Co., Ltd., Diaresin Yellow H2G manufactured by Mitsubishi Chemical Corporation, and Oil Blue No. 5502 manufactured by Arimoto Chemical Industry Co., Ltd. at a ratio of 1: 0.175: 0.9 Using.

[Examples 1 to 10], [Comparative Examples 1 to 8]
The thermoplastic resin (A), metallic luster particles (B), and dye (C) are mixed according to the composition shown in Tables 1 and 2 below, and melted at 250 ° C. using a TEM35B twin screw extruder manufactured by Toshiba Machine. A kneaded pellet was obtained. The unit of the added amount of the mixed composition is “part by mass”.
In addition, the pellets were a first of 90 mm in length, 45 mm in width, and 2.5 mm in thickness at a cylinder set temperature of 250 ° C. using a J-100EPI injection molding machine manufactured by Nippon Steel Works and an IS55EPN injection molding machine manufactured by Toshiba Machine. A second test piece having a length of 102 mm, a width of 12.7 mm, and a thickness of 2.5 mm, in which a weld was generated at the center of the test piece by the test piece and the gates at both ends, was subjected to the following evaluation.

(Characteristic evaluation)
(Evaluation of refractive index)
The thermoplastic resins (A) (A-1) to (A-3) are melted at 250 ° C. using a TEM35B twin-screw extruder manufactured by Toshiba Machine, alone or as a predetermined combination, and kneaded and pressed to form pellets. The film was produced using a compression molding machine.
Using an Abbe refractometer, the refractive index of the film was measured by a measuring method based on JIS K7142.

(Evaluation of haze)
The first test piece was measured by a measuring method based on JIS K7136 using a haze meter (NDH2000 manufactured by Nippon Denshoku Industries Co., Ltd.).

(Evaluation of orientation spots of metallic luster particles)
From the state where the second test piece is placed on a flat desk, lift the end at an angle of 30 degrees with respect to the surface of the desk, and visually check whether there is a difference in the appearance of brightness on both sides of the weld. evaluated.
○ There is no difference in how the brilliance looks.
× There is a difference in how the brightness looks.

Table 1 shows the compositions and measurement results of Examples 1 to 10, and Table 2 shows the compositions and measurement results of Comparative Examples 1 to 8.
As shown in Table 1, the ratio of the average particle diameter to the average thickness (average particle diameter / average thickness) with a thermoplastic resin having a refractive index of 1.51-1.58 and an average particle diameter of 50 μm to 600 μm. The molded bodies of Examples 1 to 10 using thermoplastic resin compositions containing metallic gloss particles coated with a metal oxide having a thickness of 40 nm to 130 nm on a flaky glass having a thickness of 5 to 60. Further, the brightness was uniform over the entire surface of the molded body on both sides with the weld as a boundary, and an effective reduction in the occurrence of uneven alignment of metallic luster particles was achieved. Moreover, haze (cloudiness) was also effectively reduced, and an excellent aesthetic appearance was obtained.
When the haze (cloudiness) is low, the transparency is excellent, and an effect that the depth is felt in the way the metallic luster particles shine is also obtained.

In Comparative Example 1, a thermoplastic resin having a high refractive index was used, and other conditions were the same as in Example 1. Compared to Example 1, the haze (cloudiness) was high, and the appearance was inferior in transparency.
When the average particle diameter / average thickness of the metallic luster particles is appropriate and the metal oxide as the coating film is a thin layer, the haze is suppressed to a low level, and the brightness of the entire molding surface is reduced on both sides of the weld. However, it was found that the occurrence of alignment spots of the metallic luster particles was effectively reduced, but the haze was increased by selecting the refractive index of the thermoplastic resin.

  In Comparative Example 2, a thermoplastic resin having a high refractive index was used, and other conditions were the same as in Example 4. Compared with Example 4, the haze (cloudiness) was high, the transparency was inferior, and the appearance was dull.

  In Comparative Example 3, a thick metal oxide film as a coating film of metallic luster particles was used, and other conditions were the same as in Example 3. Compared to Example 3, the haze (cloudiness) was high, the transparency was inferior, and the appearance was dull.

  In Comparative Example 4, a thick metal oxide film that is a coating film of metallic luster particles was used, and the other conditions were the same as in Example 5. Compared to Example 5, the haze (cloudiness) was high, the transparency was inferior, and the appearance was dull.

In Comparative Example 5, the average particle diameter of the flaky glass constituting the metallic gloss particles was small, and the metallic gloss particles were too fine. Therefore, the haze (cloudiness) was extremely high, and the whole was opaque.
In addition, the average particle size of the flake glass is small, but the metal oxide film is thick, so the brightness is uneven on both sides of the weld, and the metallic luster particles have alignment spots. I understood.

In Comparative Example 6, a glass having a large average particle diameter / average thickness value of flaky glass was used, and other conditions were the same as in Example 5.
In Comparative Example 6, since the average particle size of the flaky glass is relatively small, the average thickness is extremely thin. Furthermore, since the metal oxide film which is a coating film is also thin, the metallic luster particles are in the form of small flakes. Compared with Example 5, the haze (cloudiness) was remarkably high, the transparency was inferior, and the appearance was dull. Further, it was found that the brightness was nonuniform on both sides of the weld, and the alignment spots were generated in the metallic luster particles.

In Comparative Example 7, a flake glass having a large average particle diameter / average thickness was used, and other conditions were the same as in Example 9.
In Comparative Example 7, since the average particle diameter of the flaky glass is relatively small, the average thickness is extremely thin. On the other hand, the metal oxide film which is a coating film is relatively thick. Compared to Example 9, the haze (cloudiness) was remarkably high, the transparency was inferior, and the appearance was dull. Further, it was found that the brightness was nonuniform on both sides of the weld, and the alignment spots were generated in the metallic luster particles.

In Comparative Example 8, a thermoplastic resin having a low refractive index was used, and other conditions were the same as in Examples 4 and 9.
Compared with Examples 4 and 9, the haze (cloudiness) was high, and the appearance was inferior in transparency.
In Examples 4 and 9 and Comparative Example 8, the metal oxide film is relatively thick, but in Examples 4 and 9, the haze (cloudiness) is obtained by appropriately selecting the refractive index of the thermoplastic resin. It was found that it was possible to reduce this.

  The thermoplastic resin composition of the present invention is excellent in aesthetics and is industrially used as various products using various molded products and molded products such as automobile parts, various containers, home appliances, OA equipment, interior miscellaneous goods and the like. Has availability.

Claims (5)

A thermoplastic resin having a refractive index of 1.51 to 1.58;
Flake glass having an average particle diameter of 50 μm to 600 μm and a ratio of average particle diameter to average thickness (average particle diameter / average thickness) of 5 to 60 is coated with a metal oxide with a thickness of 40 nm to 130 nm. Metallic glossy particles,
A thermoplastic resin composition.   2. The thermoplastic resin composition according to claim 1, wherein the addition amount of the metallic luster particles is 0.01 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the thermoplastic resin.   The thermoplastic resin according to claim 1 or 2, wherein the thermoplastic resin is a copolymer of an aromatic vinyl monomer and one or more monomers copolymerizable with the aromatic vinyl monomer. Thermoplastic resin composition.   The thermoplastic resin composition according to any one of claims 1 to 3, further comprising 0.001 to 0.1 parts by mass of a dye with respect to 100 parts by mass of the thermoplastic resin.   The molded article which shape | molded the thermoplastic resin composition as described in any one of Claims 1 thru | or 4.