JPH0661913B2 - Molded product with surface gloss removed - Google Patents

Description

TECHNICAL FIELD The present invention relates to a molded article from which surface gloss has been removed.

(Prior Art and Problems Thereof) When the surface of a synthetic resin product is exposed to light, gloss is often generated when the surface is smooth. Some materials have a very strong luster, which is regarded as a characteristic of the material and has been successfully used, but in some cases, glare due to reflection of light is disliked. This is the case, for example, when the outer wall of a building receives sunlight and is dazzled by its reflection. Further, in order to change the appearance, for example, decorative appliances, wall surfaces, etc. are manufactured by intentionally removing the surface gloss. In the case of removing the luster in such a manner, usually, a mechanical method such as embossing is formed on a smooth surface, and means for optically scattering the light are taken, or the light is absorbed. It is often the case that the paint is applied.

However, if the surface of the molded product is treated by such a method, the surface becomes non-smooth, and it becomes easy to get dirty by sucking dust and the like, and the surface treatment process becomes complicated and costly. Or, there is a problem that the appearance becomes dark and the appearance deteriorates.

Therefore, it is an object of the present invention to provide a molded article from which glare due to light reflection is eliminated and surface gloss is removed.

(Means for Solving the Problems) As a result of intensive studies to achieve the above object, the present inventors have found that a matrix made of synthetic resin contains a light diffusing agent made of polymer particles. The present invention has been found out that when a resin composition is laminated on the surface of a molded product and integrated, a molded product having excellent light diffusion and a surface free of glare and having a surface gloss removed can be obtained.

That is, the present invention provides a molded article comprising a substrate and a surface layer formed on the surface of the substrate, wherein the substrate and the surface layer are integrated, wherein the surface layer is composed of (a) a synthetic resin. (B) a layer thickness of at least 20 μm, wherein the polymer particles are core / shell polymer particles, and the core is cross-linked or graft-bonded. And a rubber-like C _2-8 alkyl acrylate polymer, which has a refractive index within the range of ± 0.2 of the refractive index (▲ n ²⁵ _D ▼) of the matrix synthetic resin, and the shell has at least one layer. 5-40% by weight of the total polymer particles
And the outermost layer of which is compatible with the matrix synthetic resin.

The present invention provides a molded article with the surface gloss removed.

A synthetic resin is used for the substrate of the molded article of the present invention, and the type thereof is not particularly limited, and either a thermoplastic resin or a thermosetting resin can be used.

The molded article of the present invention is one in which a layer composed of a resin composition containing a light diffusing agent in a matrix is laminated and integrated on the surface of the above-mentioned synthetic resin substrate.

In the resin composition constituting the surface layer of the molded article of the present invention, as a synthetic resin that can be used as a matrix,
For example, polyolefin resin such as polyethylene and polypropylene; olefin-vinyl acetate copolymer; polyalkyl (meth) acrylate (methacrylic resin) such as polymethyl (meth) acrylate; vinyl chloride resin; polyester; polyamide resin such as nylon; polycarbonate; Polystyrene; polyimide; polyglutarimide;
Examples thereof include fluororesins, which can be used alone, as a copolymer, or as a mixture.

As the above synthetic resin, those having both heat resistance and impact resistance are preferable.

The resin composition constituting the surface layer of the molded article of the present invention is characterized in that the matrix made of the above synthetic resin contains a light diffusing agent. When particles of an organic polymer compound are used as such a light diffusing agent, the light transmittance is appropriate and the light diffusing property is excellent, which is preferable. Specifically, an alkyl (meth) acrylate resin is used. Examples thereof include monovinylarene-based resins such as styrene-based resins and vinylcarboxylate resins. These can be used as a homopolymer or a copolymer, as a mixture, or as a multilayer.
An alkyl acrylate resin is preferable, and a resin in which the above resin is further laminated as a core is further preferable. As such an example, Japanese Patent Laid-Open No. 63-137911
There is a granular polymer composition disclosed in Japanese Patent Publication No. 63-119419 and Japanese Patent Application No. 63-119419.

Further, the organic polymer diffusing agent, for example, talc,
_{TiO 2, SiO 2, CaCO 3} , Al 2 O 3 known may be used inorganic pigments The combined goods such.

The particles of the light diffusing agent are usually substantially spherical and have an average particle diameter of 0.1 to 500 μm. Here, the average particle size refers to the average particle size measured by Nanosizer. In addition, it is preferred that at least 90% by weight of the particles described above have a particle size distribution such that they fall within ± 20% of the average particle size.

From the viewpoint of making the light diffusing agent good, it is preferable that the refractive index (N _d ) of the light diffusing agent has the following relationship with the refractive index (N _m ) of the above-mentioned synthetic resin which is the matrix.

0.003 ≦ | N _m −N _d | ≦ 0.2 (However, the refractive index here is ▲ n ²⁵ _D ▼) The above light diffusing agent particles are contained in the above synthetic resin (matrix) in an amount of 0.1 to 40 weight. % Is compounded. It is preferable that the particles are uniformly dispersed in the matrix because the light diffusivity is good.

The polymer composition disclosed in Japanese Patent Application No. 63-119419 is particularly preferable as the resin composition in which the light diffusing agent is mixed and dispersed in the synthetic resin. That is, a thermoplastic or thermosetting matrix polymer with 0.1-40% of the total composition in it.
A substantially spherical shape having an average of 2 to 15 μm dispersed in an amount of wt% and having a particle size distribution such that at least 90 wt% of the particles fall within ± 20% of the average particle diameter. It is a thermoplastic or thermosetting polymer composition containing polymer particles. Further, among them, the polymer composition is a light-scattering composition based on a thermoplastic polymer matrix, and the spherical polymer particles are 0.1 to 10 of the total weight of the composition.
%, The spherical polymer particles comprise 0 or up to 5% (based on the total weight of the core) of crosslinker and 0%.
Alternatively, the refractive index (▲ n ²⁵ _D ▼) copolymerized with up to 5% of the graft binder is ± 0.2 of the refractive index of the matrix polymer.
A core of a rubbery alkyl acrylate polymer (wherein the alkyl group has 2 to 8 carbon atoms) within the range of units, but preferably not closer than ± 0.03 units, and one or more layers Is particularly preferred, which is a core / shell polymer having a polymer shell of (wherein the outermost layer is compatible with the matrix polymer and the shell comprises 5-40% of the weight of the particles).

The method of mixing and dispersing the light diffusing agent particles in the synthetic resin may be a known method, for example, a method of kneading the synthetic resin and the light diffusing agent in an extruder and molding.
A method such as a co-spray method, a method of mixing an emulsion type synthetic resin and a light diffusing agent, coagulating with a coagulant at the same time, and molding (US Pat. No. 3,751,527) can be appropriately used. .

In addition, additives such as flame retardants, dyes and heat stabilizers can be mixed into the resin composition forming the surface layer, if necessary.

The surface layer composed of the resin composition in which the above-mentioned light diffusing agent particles are contained in the matrix can sufficiently exert the effect of removing surface gloss if the thickness thereof is at least 20 μm. It is preferably 100 to 4000 μm.

The above-mentioned surface layer is laminated on a substrate synthetic resin, and the method for producing a molded article of the present invention having an integrated structure, in which the surface gloss is removed, includes a method of co-extruding a substrate material and a surface layer material, a substrate Method of coating surface layer material on resin, method of bonding base resin and surface layer (post-
Lamination) and the like, and the method of coextrusion is preferable.

The molded article from which the surface gloss has been removed according to the present invention is, for example, an external wall of a building, an indoor wall, a window, a decorative article, a package, tableware, sanitary equipment, parts of a car, a recreational vehicle, or the like. It can be used in all fields to obtain.

(Function) Since the molded article from which the surface gloss is removed of the present invention has a light diffusing surface layer composed of a synthetic resin containing a light diffusing agent, it has a mechanical surface gloss such as an embossing roll. No removal treatment step is required, and in addition, even if the thickness of the surface layer is small, the effect of removing the surface gloss is high, so that the cost can be kept low. Further, since the surface layer is provided, the mechanical strength of the molded product is improved as compared with the case where only the base resin is used. However, it does not significantly affect other physical properties of the base resin.

Further, since the surface layer has excellent light diffusing property, the appearance does not become dark.

(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples.

Example (1) Production of light diffusing agent Step a First, the following aqueous mixture was prepared.

Next, the mixture A was put into a reactor equipped with a stirrer and a cooler and filled with nitrogen, and heated to 87 ° C.

To this stirred reactor contents was added 7% of Mixture B and all of Mixture C and the reactor contents were stirred for 30 minutes. The rest of mixture B and mixture D were then added with stirring over 90 minutes. The reactor contents were maintained at 87 ° C. for 50 minutes with stirring, after which the resulting polymer emulsion (a) was cooled to room temperature.

When measured with a Nanosizer, the particle size of the polymer (butyl acrylate-styrene) particles is 0.3μ.
It was m.

Step b Here, an emulsion of butyl acrylate and butylene glycol diacrylate crosslinkable monomer and allyl methacrylate graft-linkable monomer was used to prepare a uniform particle from the particles having a 0.3 μm particle size of step a. The particles were grown to a size of 2 μm particles.

The following aqueous mixture was prepared.

Mix A with Mix B and Waring Blender
The emulsion was prepared by mixing in a g Blender) for 3 minutes. This emulsion was put into a pressure type reaction vessel containing the mixture C, and the content of the reaction vessel was stirred for 1 hour under nitrogen filling.
The reaction vessel was sealed and shaken in a 68 ° C. water bath for 3 hours, then cooled to room temperature.

The resulting polymer particles had a particle size of about 2 μm.

Step c Here, the particles of 2 μm in step b above were grown to particles having a particle size of 5 μm. Mixture C is step b
The operation of step b was repeated, except that the amount of the particle suspension prepared in (3) was 23 parts by weight. The obtained particles are about 5 μm
Had a particle size of.

Step d Here, the outer shell of methyl methacrylate and ethyl acrylate is polymerized on the particles of the above Step c,
Finished into core / shell polymer particles.

The following aqueous mixture was prepared.

Mixture A was weighed into a reactor equipped with a stirrer and condenser and filled with nitrogen. The reactor contents were heated to 65 ° C. and stirred under a nitrogen blanket. Mixtures B, C and D
Were added separately into the reactor over 90 minutes. The temperature was maintained at 65 ° C and stirred for 30 minutes. The reactor contents were then cooled to room temperature.

The particles of the light diffusing agent (polymer laminate) thus obtained are
The number of particles having a particle size of about 5 μm and 2 to 4 μm is about 20% or less, and the very small particle size is 0.5 μm.
It was m or less. Also, the refractive index of the polymer particles (▲ n
²⁵ _D ▼) was 1.46.

(2) Production of light diffusing resin composition Here, a light diffusing resin composition was produced using the core / shell polymer particles (light diffusing agent) produced in (1).

The light diffusing agent obtained in (d) of (1) was isolated from the aqueous suspension by coagulating with a calcium hypophosphite coagulant, and 5 parts by weight of the particles were It was melt mixed at 232 ° C. with 95 parts by weight of poly (methyl methacrylate) having a weight average molecular weight of 120,000.

Here, the refractive index (▲ n ²⁵ _D ▼) of poly (methyl methacrylate) used as the matrix of the surface layer is
It was 1.49.

(3) Manufacture of molded product A molded product was manufactured using the ABS resin as a substrate, using the light diffusing resin composition manufactured in (2) as the surface layer.

For this molded product, the Hunter Lab Gloss Meter (Hunte
The surface gloss was measured using a rlab glossmeter, Model 48-7).

The surface gloss (60 degrees) was 38.

(Effects of the Invention) The molded article of the present invention from which the surface gloss has been removed can be easily manufactured and the cost can be reduced. In addition, the mechanical strength of the molded product is improved and the appearance is also good, so that its industrial value is great.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Jun-Chen Woo 18966, Pennsylvania, USA, Holland, Heather Valley Road 105 (56) References JP-A-56-95640 (JP, A) JP-A-63- 119419 (JP, A) JP-A-63-137911 (JP, A)

Claims (1)

[Claims] 1. A molded article comprising a substrate and a surface layer formed on the surface of the substrate, wherein the substrate and the surface layer are integrated, wherein the surface layer comprises (a) a synthetic resin. (B) the layer thickness is at least 20 μm, the polymer particles are core / shell polymer particles, and the core is cross-linked or graft-bonded. And a rubber-like C _2-8 alkyl acrylate polymer, which has a refractive index within the range of ± 0.2 of the refractive index (▲ n ²⁵ _D ▼) of the matrix synthetic resin, and the shell has at least one layer. 5-40% by weight of the total polymer particles
And the outermost layer of which is compatible with the matrix synthetic resin.