JPS60135225A - Transparent acrylic resin film with non-shining surface - Google Patents

Abstract

PURPOSE:To obtain a transparent acrylic resin film excellent in a matte characteristic, by mixing a rubber modified acrylic resin composition having a specific melt flow index and talc containing 1wt% or less of particles of which the particle size exceeds a specific one in a specific compounding ratio and subsequently forming the resulting mixture into a film by a melt extrusion process. CONSTITUTION:1-10wt% of talc containing 1wt% or less of particles, of which the particle size exceeds 10mum, is mixed with 99-90wt% of a rubber modified acrylic resin composition of which the melt flow index MI is 0.6-20g/10min and the resulting mixture is formed into a film by melt extrusion process to obtain a transparent matte acrylic resin film. A resin with MI of below 0.6g/10min can not be continuously formed into a film with a thickness of 50mum or less and, when MI exceeds 20g/10min, the stable formation of a film becomes difficult because draw-down from a die at the time of melt extrusion is large. When the content of particles with a particle size exceeding 10mum exceeds 1wt%, the film forming property of the film becomes poor and continuous film formation is difficult. Further, when the content of talc is below 1wt%, sufficient matte effect is not obtained and, when exceeds 10wt%, the film forming property or mechanical strength of the film is lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an acrylic resin film that is transparent and has excellent matte properties.

Acrylic resin film is known for its transparency and weather resistance.

It has been widely used due to its excellent properties such as surface gloss. However, recently there has been an increasing demand for matte acrylic resin films with no surface gloss. In particular, it is expected to be used as a coating material for applications that dislike surface reflection, such as coating vinyl chloride wallpaper and furniture materials.

However, since there are few matting agents suitable for acrylic resin films, it is difficult to obtain matte films with excellent appearance. □As a prior art, for example, Japanese Patent Laid-Open No. 58-23973 proposes the use of a polymer matting agent having an average particle size of 1 to 500 μm. However, if the average particle diameter exceeds 50 μm, roughness will occur on the film surface when the film is formed by melt extrusion. Therefore, in order to obtain a matte film with excellent texture, a matting agent with an average particle size of 1 to 50 μm is required. However, when producing crosslinked polymer particles as a matting agent by emulsion polymerization, it is difficult to obtain particles of 1μ or more, and when using suspension polymerization, it is extremely difficult to obtain particles of 50μ or less. Since it is difficult, there is a problem in practicality.

The present invention was made against this background, and its purpose is to obtain an acrylic resin film that is transparent and has excellent matte properties.

That is, the acrylic resin film according to the present invention has a melt flow index (hereinafter abbreviated as MI).

Measurement conditions: 230°C, 3 soog) is 0.6 g for 710 minutes or more, ji' 710 minutes or less. %) or less by mixing 1 to 10 wt% of talc and forming a film by melt extrusion.

The thickness of the film varies depending on the application, and the generally preferred range is 20μ to 100μ, more preferably 25μ to 75μ
μ.

The rubber-modified acrylic resin composition used in the present invention is a resin composition containing an acrylic rubber containing methyl methacrylate as a main component. For example, there are resin compositions comprising a blend of an acrylic multistage polymer and a methacrylic resin, as disclosed in Japanese Patent Publication No. 55-27576, Japanese Patent Application Laid-open No. 53-38554, and % Japanese Patent Publication No. 57-200412.

When continuously forming films using such a resin composition, the MI is 0. L! It is necessary that the time is 9/lo minutes or more and 20g710 minutes or less. With a resin having an MI of less than 0.6 g and 710 minutes, it is not possible to continuously form a thin film of 50 μm or less. If the raw MI exceeds 20 g/lo, it becomes difficult to stably form a film due to large drawdown from the goo during melt extrusion.

Depending on the intended use, the matting agent used in the present invention must be able to eliminate the surface gloss of the film and have transparency that allows the patterns and patterns of the object to be coated to be seen. Furthermore, it must not impede the characteristics of acrylic resins, such as weather resistance, and must satisfy many conditions such as film formability and 2 strength. As a result of intensive study by the present inventors on a matting agent that satisfies these conditions, we found that 1 to 10 wt%, preferably 1 to 1 g of talc containing 1 wt% or less of particles with a particle size exceeding 10μ
It has been discovered that a film meeting the objectives of the present invention can be obtained by mixing wt%. If particles with a particle size exceeding 10 μm exceed 1wt1, the film formability deteriorates and continuous film formation becomes difficult. Further, if the talc content is less than 1 wt%, a sufficient matting effect cannot be obtained, and if it exceeds 10 wt%, the film formability and mechanical strength of the film will decrease. Also,
Since the matting effect hardly changes in the range of 8 to 10 wt%, the talc content should be 1 to 8 wt% from the viewpoint of cost etc.
A range of wt% is preferred.

It is preferable from the viewpoint of film strength. this is,
This is because the silane coupling agent increases the affinity with the rubber-modified acrylic resin composition.

As the silane coupling agent, ordinary ones can be used. For example, a known silane coupling agent is preferably used, which is used as a surface treatment agent for glass fibers, glass beads, etc., which is used as a reinforcing agent for engineering resins such as nylon and polyacetal.

Also, alkoxysilanes (eg, alkyltrialkoxysilanes) are preferably used as silane cassilling agents in the present invention.

Regarding the manufacturing method of the film, it is made by melt extrusion film forming, and T
The film can be formed by a conventional method such as a die method or an inflation method.

The present invention will be explained below with reference to Examples.

The evaluation method used in the examples is shown below.

(1) Film-forming property ○: A film with a thickness of 25 μm can be stably formed using the T-die method.

Δ: A film with a thickness of 50 μm can be stably formed using the T-die method.

×: It is difficult to form a film with a thickness of 50 μm using the T-die method.

(2) Optical properties Matting property: 45' according to ASTM 02157 test method
Glossiness value ○: Glossiness value is less than 60% Δ: Glossiness value is 60-80 x: Glossiness value exceeds 80%.

Transparency: Haze (according to ASTM D1003 test method)
Haze) value ○: Haze value is less than 60% Δ: Haze value is 60-80% ×: Haze value is over 80%.

(3) Mechanical properties Tensile strength: Based on ASTM D882 test method.

○: Tensile strength exceeds 2-oKy/- △: Tensile strength 1.5 to Z 0 K5i/mA×: Tensile strength 1. Less than sKy/-.

Example 1. Comparative Example 1 The first layer produced by emulsion polymerization according to Example 1 of JP-A-57-200412 was methyl methacrylate (hereinafter referred to as M
A multi-stage rubber elastic body composition in which the second layer is an acrylic rubber polymer mainly composed of argyl methacrylate, and the third layer is a hard polymer mainly composed of MMA. A mixture of 88 wt% MMA, 12 wt% methyl acrylate, and a methacrylic resin with an MI of 12 at a ratio of 30 to 00 (MI = 41 and Merck (manufactured by Nippon Talc@) was mixed and passed through a screw extruder into pellets. It became.

Furthermore, this pellet is adjusted to a temperature of approximately 2
A film having a width of 700 mm and a thickness of 25 μm was formed by passing through an extruder specified at 40° C. and using a T-die method at a drawing speed of 4 m/min. The diameter and amount of talc were prepared and evaluated in different combinations as shown in Table 1.

With the product of the present invention, a film with excellent film formability, optical properties, and mechanical properties can be obtained, whereas the amount of Merck is 1 wt.
% (Comparative Example (1)), the matting effect is insufficient, and the amount of talc exceeds 10wt (Comparative Example (IIL)).
) was a film with extremely low commercial value due to lack of mechanical strength. In addition, those containing 1 wt% or more of Merck particles with a particle size of 10 μ or more (Comparative Example (iii)):
It was not possible to stably form a 50μ film.

Comparative Example 2 In the same manner as in Example 1, a mixture (M I 0.2) was prepared by mixing a multistage rubber elastic body composition and a commercially available methacrylic resin (Delpetsu 8ON, manufactured by Mukasei Kogyo ■) at a ratio of so:so.
．． ! ii'/10 minutes) to 100 parts by weight of talc (
5 parts of the mixture (not containing particles with a diameter exceeding 10 μm) were added and mixed, pelletized through an extruder, and then formed into a film using the T-die method. When attempting to form a film thinner than 50 μm, resin breakage occurred frequently and stable film formation was not possible.

Example 2. Comparative Example 3 To the mixture I used in Example 1, 1 to 10% of talc, mica, and barium sulfate, which do not contain particles with a particle size exceeding 10μ, are added.
After adding wt and mixing, pelletizing through an extruder, a film was formed by a T-die method. The film forming properties were all good except for sulfuric acid and ζlium. When barium sulfate was added, stable film formation was not possible when the thickness was less than 25 μm. Other matting agent enriched films were evaluated for optical properties. As shown in FIG. 1, the only one with good gloss and haze was the one containing talc.

Example 3 The mixture used in Example 1 was mixed with 3% Merck (invention product 1), and the talc was mixed with long chain alkyl (C16
A mixture of 3 wt% of triethoxysilane (estimated to be ~CI8) (manufactured by Taihe Kagaku ■: product number RT-168E) by a conventional method using Th (product of the present invention 4), After pelletizing through an extruder, a film with a thickness of 25 μm was formed using a T-die method. The film formability and optical properties were the same for Invention Product 19 and Invention Product 4, but the opening strength of Invention Product 1 was -P/- for Z9, while Invention Product 4 was 3. .81'-p/-, about 30
%Rose.

Margin below

[Brief explanation of drawings]

FIG. 1 illustrates the results of Examples and Comparative Examples. l is the gloss and cloudiness when 1 wt% to 10 wt% of mica is mixed! It shows the change from llv. 2 shows changes regarding talc. Patent applicant Asahi Kasei Kogyo Co., Ltd.

Claims (1)

[Claims] 1. A rubber-modified acrylic resin composition with a melt flow index of 0.6.9/10 min or more and 20 g/io min or less, with a content of 99 to 90 parts by weight, and a content of particles with a particle size exceeding 10 μm not more than 1 part by weight. The acrylic resin film according to claim 1, characterized in that it contains a transparent matte acrylic resin film, which is obtained by mixing 1 to 10 parts by weight of talc and then melt-extruding the film.