JPH09211202A - Antidazzle film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an antidazzle film capable of keeping a good antidazzle property, low in haze value and good in visibility by incorporating transparent spherical particles of specified refractive index into a transparent film material and specifying the average diameter of the transparent spherical particles. SOLUTION: This antidazzle film 10 contains transparent spherical particles 3 having refractive index of 1.4-1.6, and the average diameter of the particles 3 is controlled to 1.5-4.0μm. The average diameter is determined in accordance with the kind of the particles 3. Further., 2.5-10 pts.wt. of the particles 3 has to be incorporated into 100 pts.wt. of a transparent film material 2 to obtain a good antidazzle property and a low haze. The transparent film material 2 is formed a silicone-base hard coating agent or an acrylic hard coating agent. The particles 3 are formed from one or more kinds from among silica, silicone, melamine resin and glass bead.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for improving visibility, and more specifically, a polarizing film or the like (for example, an antiglare device for vehicles, lighting equipment, various display devices, reflecting mirrors, filters, The present invention relates to an antiglare film used on the surface of a retardation plate, a touch panel, various optical films).

[0002]

2. Description of the Related Art Conventionally, a polarizing film disposed on the surface of an LCD is subjected to an antiglare treatment on the outermost surface thereof in order to prevent a reduction in visibility due to surface reflection of external light. This antiglare treatment is performed through a step of applying a transparent film material (silicone type hard coating agent or acrylic type hard coating agent) to which amorphous silica is added to the surface of a polarizing film, a step of heat curing or a step of UV curing. . That is, as the antiglare film formed by this antiglare treatment, a material obtained by adding amorphous silica to a transparent film material made of a silicone hard code material or an acrylic hard coating agent is applied.

As a conventional technique relating to this type of antiglare film, Japanese Patent Laid-Open Nos. 6-87632 and 6-1870 are available.
Known are those disclosed in Japanese Patent Laid-Open No. 6-29, Japanese Patent Application Laid-Open No. 4-249145, and Japanese Patent Application Laid-Open No. 1-105738. These will be briefly described.

First, the one disclosed in Japanese Patent Laid-Open No. 6-87632 is a low-reflection conductive film having an antiglare effect, and amorphous silica (SiO ₂ ) is used as an antiglare film imparting the antiglare effect. A material whose main component is is used. This antiglare effect is based on the surface irregularities formed by spray-coating a material containing amorphous silica (SiO ₂ ) as a main component and heating it.

Next, the one disclosed in JP-A-6-18706 relates to a scratch-resistant antiglare film. According to this, the antiglare layer having an antiglare effect uses a resin bead having a refractive index of 1.40 to 1.60 and a coating composition containing an ionizing radiation curable resin composition as a main component. This antiglare film is formed through the steps of coating a transparent substrate and irradiating with ionizing radiation. In this case, the shape of the resin beads to be added is not specified.

Next, the one disclosed in JP-A-4-249145 relates to an antiglare film applied to a flat panel display such as a liquid crystal display or a plasma display. According to this, the anti-glare film is obtained by spraying grinding powder powder on the surface of a clear resin coated film containing no pigment (sandblasting).
Is formed. In this way, by spraying the grinding powder powder onto the surface, the surface is roughened and scratch resistance and chemical resistance are improved.

The one disclosed in JP-A-1-105738 relates to a triacetate film. This film is obtained by coating a composition liquid in which a necessary amount of amorphous silica powder is mixed with an ultraviolet curable epoxy acrylate resin on an unsaponified triacetate film. This imparts scratch resistance, chemical resistance, and antiglare property.

[0008]

However, in the above-mentioned conventional antiglare film, the amorphous silica or resin beads added to the transparent film material or the ground powder powder to be sprayed has a complicated surface shape. However, there is a problem that diffuse reflection of light increases. In addition, the use of amorphous silica has a problem that diffused reflection of transmitted light is large.

Further, there is a problem that good antiglare property and low haze cannot be secured due to the diffused reflection. The haze value is a value represented by diffuse transmittance / total light transmittance, and the smaller this value, the better the resolution, the contrast and the transparency. As for the antiglare property, the higher the score is, the better the antiglare property is, as shown in the antiglare property described later, that is, the item of the method for evaluating the antiglare property and haze value shown in the examples.

In addition, when the amorphous silica is added to and dispersed in the hard coat agent in the antiglare treatment, the amorphous silica is easily crushed and the initial particle size of the amorphous silica cannot be maintained. There was a problem. In this case, if attention is paid to maintaining the particle size of the amorphous silica, there is a problem that stirring for obtaining sufficient dispersibility cannot be performed.

The present invention has been made to solve the above problems, and an object thereof is to maintain good antiglare property and to show low haze value. Another object is to provide an antiglare film with good visibility.

[0012]

In order to achieve this object, the antiglare film of the present invention has a refractive index of 1.4 to 1.4 in the transparent film material.
The gist is that the transparent spherical particles of 1.6 are contained and the average particle diameter of the transparent spherical particles is in the range of 1.5 to 4.0 microns. An appropriate value is determined for this particle size depending on the type of transparent spherical particles.

Further, in order to obtain good antiglare property and low haze, it is important that the weight ratio of the transparent spherical particles is in the range of 2.5 to 10 parts by weight with respect to 100 parts by weight of the transparent film material. is there. For example, in the case of spherical silicone, spherical melamine, spherical glass beads, etc., if the amount exceeds this range, there is no problem in obtaining good antiglare property, but the haze value becomes high. On the other hand, if it is less than this range, it is possible to obtain a low haze value, but it is difficult to obtain good antiglare properties.

Further, the transparent film material is formed of a silicone-based hard coating agent or an acrylic-based hard coating agent, and the transparent spherical particles are one or more of silica, silicone, melamine resin, and spherical glass beads. When formed in the above proportion, good antiglare property and low haze value are realized when added in the above proportions.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below in detail. In the text described below, “good antiglare property” means “5 points” when evaluated by the evaluation method of antiglare property in Table 1 described later.

(1) Structure of Antiglare Film The structure of the antiglare film will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram showing a cross-sectional structure of an antiglare film in one example of the present invention, and 1 is a polarizing film. Reference numeral 2 is a transparent film material, which is formed of a silicone hard coating agent or an acrylic hard coating agent.

Reference numeral 3 is a transparent spherical particle, which is made of one kind or plural kinds of materials of silica, silicone, melamine resin, and glass beads. 10 is an antiglare film. The antiglare film 10 is formed by using a compounding agent in which the transparent spherical particles 3 are added to the transparent film material 2 through a coating process, a heat curing process, or a UV curing process. Next, FIG. 2 is a diagram showing a cross-sectional structure of an antiglare film used as a comparative example. In the figure, 4 is amorphous silica (amorphous particles).

(2) Evaluation Method of Characteristics of Antiglare Film, that is, Antiglare Property and Haze Value First, the antiglare property was evaluated by an experiment shown in FIG. This experiment will be briefly described. First, transparent spherical particles 3 or amorphous particles 4 made of any one of spherical silica, spherical silicone, spherical melamine, spherical glass beads, and amorphous silica is added to either a silicone hard coat agent or an acrylic hard coat agent. Then, the compounding agent, that is, the base of the antiglare film 10 is prepared. At this time, a surfactant is added if necessary. Then, this compounding agent was mixed with a homogenizer at 15000 r.p.m. p. Stir for 15 min at a rotation speed of m. Specific examples of the compounding agents will be shown later as Examples 1 to 7 and Comparative Examples 1 to 6.

Each of these compounding agents has a film thickness of 10 μm.
The TAC film 6 is applied to the TAC film 6 as an anti-glare film 10 with a certain thickness (coating step), and heat curing treatment (heat curing step).
Give. Then, the TAC film 6 on which the antiglare film 10 is formed (the antiglare film according to Examples and Comparative Examples described below) is placed on the glass plate 5. Next, the light of the fluorescent lamp 7 is irradiated obliquely from above the TAC film 6, and the experimenter 8 views the TAC film 6 in such a positional relationship that the incident angle and the reflection angle of the light are 60 °. . Then, the experimenter 8 observes and evaluates the degree of reflection of the light of the fluorescent lamp 7 on the TAC film 6 as the antiglare property.

The antiglare property (degree of reflection) is evaluated by the 5-point method. The criteria are as shown in Table 1 below.

[0021]

[Table 1]

The length m of the optical path from the fluorescent lamp 7 to the TAC film 6 and the length n of the optical path from the TAC film 6 to the experimenter 8 are the same in both Examples and Comparative Examples described below. Is. Next, the haze value is
It is measured by a haze meter.

(3) Compounding agent used for evaluation

[Examples] Table 2 shows the blending and evaluation results of Examples 1 to 4 using a silicone-based hard coating agent as a transparent film material, and Table 3 shows a silicone-based hard coating agent as a transparent film material. The composition and evaluation results of Comparative Examples 1 to 4 are shown. Further, in Table 4, Examples 5 to 7 and Comparative Example 5 in which an acrylic hard coating agent was used as the transparent film material.
Formulations of ~ 6 and evaluation results are shown. To all the samples of these Examples and Comparative Examples, 2 parts by weight of a surfactant (for example, nonionic surfactant) was added as needed.

First, in the case of using a silicone type hard coating agent, the compounding agents of Examples 1 to 4 and Comparative Examples 1 to 4 will be described with reference to Tables 2 and 3.

[0025]

[Table 2]

[0026]

[Table 3]

Example 1 Spherical silica φ2.3 μm
7. 10 parts by weight to 100 parts by weight of silicone-based hard coating agent having a refractive index of 1.44 (amount of silicone component);
Consists of 4 samples containing 5 parts by weight, 5 parts by weight, 2.5 parts by weight. (Example 2) Ratio of 10 parts by weight, 5 parts by weight, and 2.5 parts by weight of spherical silicone φ1.5 μm with respect to 100 parts by weight of silicone hard coat agent having a refractive index of 1.44 (amount of silicone component) It consists of 3 samples contained in.

(Example 3) Spherical melamine φ4.0 μm
However, a silicone-based hard coating agent having a refractive index of 1.44 10
0 parts by weight (silicon component amount), 10 parts by weight,
Consists of 3 samples containing 5 parts by weight and 2.5 parts by weight. (Example 4) Spherical glass beads φ3.0 μm were used in an amount of 10 parts by weight, 5 parts by weight, and 2.5 parts by weight with respect to 100 parts by weight (silicon component amount) of a silicone-based hard coating agent having a refractive index of 1.44. It consists of three samples contained in proportion.

Comparative Example 1 Spherical silica φ0.48 μm
However, a silicone-based hard coating agent having a refractive index of 1.44 10
0 parts by weight (silicon component amount), 10 parts by weight,
Consists of 3 samples containing 5 parts by weight and 2.5 parts by weight. (Comparative Example 2) Ratio of 10 parts by weight, 5 parts by weight, and 2.5 parts by weight of spherical melamine φ1.25 μm with respect to 100 parts by weight (silicon component amount) of a silicone-based hard coating agent having a refractive index of 1.44. It consists of 3 samples contained in.

(Comparative Example 3) Amorphous silica φ1.9 μm
However, a silicone-based hard coating agent having a refractive index of 1.44 10
0 parts by weight (silicon component amount), 10 parts by weight,
Consisting of 3 samples containing 5 parts by weight and 2.5 parts by weight (Comparative Example 4) Amorphous silica φ5.2 μm has a refractive index of 1.
1. 44 parts by weight of 100 parts by weight of the silicone-based hard coating agent (silicon component amount), 10 parts by weight, 5 parts by weight, 2.
It consists of 3 samples contained in a proportion of 5 parts by weight.

Next, referring to Table 4, the compounding agents of Examples 5-7 and Comparative Examples 5-6 will be described. (Example 5) Spherical silica φ2.3 μm has a refractive index of 1.5.
For 100 parts by weight of the acrylic hard coat agent of 2,
It consists of two samples containing 10 parts by weight and 5 parts by weight.

Example 6 Spherical silicone φ1.5 μm
However, the acrylic hard coating agent 100 with a refractive index of 1.52
It is composed of two samples containing 10 parts by weight and 5 parts by weight with respect to parts by weight. Example 7 Spherical melamine φ4.0 μm has a refractive index of 1.
It is composed of two samples containing 10 parts by weight and 5 parts by weight with respect to 100 parts by weight of the acrylic hard coating agent of No. 52.

Comparative Example 5 Amorphous silica φ1.9 μm
However, the acrylic hard coating agent 100 with a refractive index of 1.52
It is composed of two samples containing 10 parts by weight and 5 parts by weight with respect to parts by weight. Comparative Example 6 Amorphous silica φ5.2 μm has a refractive index of 1.
It is composed of two samples containing 10 parts by weight and 5 parts by weight with respect to 100 parts by weight of the acrylic hard coating agent of No. 52.

(4) Evaluation Result Next, the evaluation result will be described with reference to FIGS. First, FIG. 4 is a graph showing the evaluation results shown in Tables 2 and 3, and FIG. 5 is a graph showing the evaluation results shown in Table 4. In these figures, the horizontal axis shows the antiglare property by the above-mentioned 5-point method, and the vertical axis shows the haze value. In addition, white ones in the drawings show examples, and black ones show comparative examples. In addition, the properties of the antiglare film show good antiglare properties and low haze values as it goes to the lower right in the figure. 4 to 5, it can be said that the sample to which the transparent spherical particles are added is superior to the sample to which the amorphous silica is added because there are many samples plotted in the lower right.

The evaluation results will be described in detail below. 1. Comparison of transparent spherical particles and amorphous particles According to the evaluation results shown in FIG.
Out of 13 samples, 12 samples show good antiglare property (antiglare property shows 5). On the other hand, in Comparative Examples 1 to 4, 2 out of 12 samples are
It shows good antiglare properties. Regarding the haze value, Comparative Example 1
The spherical silica of No. 1 shows the lowest value, but this has poor antiglare property and is not suitable for use. On the contrary, the amorphous silica of Comparative Example 4 exhibits good antiglare property, but has a high haze value and is not suitable for use. On the other hand, each of Examples 1 to 4 exhibits good antiglare property and has a low haze value. Therefore, the visibility is improved.

In FIG. 4, in particular, spherical silicone φ
The antiglare film containing 1.5 μm in a ratio of 2.5 parts by weight (Example 2) is the most excellent and has good visibility in terms of achieving both good antiglare property and low haze value. . In addition, an antiglare film containing spherical silica φ2.3 μm in a ratio of 7.5 parts by weight (Example 1), an antiglare film containing spherical melamine φ4.0 μm in a ratio of 2.5 parts by weight (implementation) Example 3),
The antiglare film containing spherical glass beads φ3.0 μm in a ratio of 2.5 parts by weight (Example 4) is excellent in that it has both good antiglare property and low haze value. Good nature.

Further, according to the evaluation results shown in FIG. 5, all of the six samples of Examples 5 to 7 were
It shows good antiglare properties. On the other hand, in Comparative Examples 5 and 6, two out of four samples show good antiglare properties. Therefore, in Examples 5 to 7, Comparative Example 5 was used.
Visibility is good for items up to 6. According to FIG. 5, the spherical silica of Example 5 having a diameter of φ2.3 μm is the most excellent.

Further, in the case of producing an antiglare film, in the case of transparent spherical particles, it has sharp points like amorphous particles,
Since it does not have a structure with irregularities, even if it is stirred into a transparent film material at a high rotation speed after it is contained in the transparent film material, the shape does not change so the initial particle size can be maintained Is. Therefore, it becomes easy to obtain the desired antiglare property and haze value.

2. Effect of spherical diameter of transparent spherical particles Next, according to the evaluation result shown in FIG. 4, spherical silica φ2.3
Comparing the one with μm and the one with spherical silica φ0.48 μm, regarding the anti-glare property, the spherical silica φ2.3 μm
The ones are better. Haze value is spherical silica φ
The one having 0.48 μm is superior, but the antiglare property is not suitable for use. Therefore, spherical silica φ2.3 μm is preferable.

[0040] 3. Depends on the proportion of transparent spherical particles
Effect According to the evaluation results shown in FIGS. 4 and 5, the ratio of the weight of the transparent spherical particles is 100 parts by weight of the transparent film material.
It is in the range of 2.5 to 10 parts by weight. This is based on the fact that the smaller the proportion of the transparent spherical particles, the lower the haze value and the better the visibility, but when the proportion is too small, the antiglare property deteriorates.

In the case of Examples 2 to 4, the optimum proportion of spherical silicone, spherical melamine and spherical glass beads is 2.5 parts by weight. Further, in the case of Example 1, the optimum proportion of spherical silica is 7.5 parts by weight. Regarding the spherical silica of Example 1,
Realization of good antiglare property and low haze is inferior to that of spherical silicone, spherical melamine, and glass beads, but excellent in realization of low haze. Further, spherical silicone, spherical melamine, the ratio of containing spherical glass beads and the haze value shows a positive correlation, but the ratio of containing spherical silica and the haze value show a specific correlation. Not in.

[0042] 4. The transparent film material is silicone-based hard coating.
When used as an adhesive agent and when used as an acrylic hard coat agent
Comparison with Tables 2 to 4, and based on FIGS. 4 and 5, when comparing the types of hard coating agents, the silicone type hard coating agents are slightly superior. Shows good anti-glare property, and
The haze value showing a single digit value exists only when the silicone hard coat agent is used.

However, the antiglare property and the haze value are close to each other. Therefore, it is preferable that the antiglare film is used more appropriately than the superiority or inferiority of the antiglare film according to the application, material, and atmosphere in which the antiglare film is used.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, in the above example, one type of transparent spherical particles was added to the silicone hard coating agent or the acrylic hard coating agent,
As the transparent film material, it is possible to select either a silicone-based hard coating agent or an acrylic-based hard coating agent, and as the transparent spherical particles, those formed from a plurality of silica, silicone, melamine resin, or glass beads are used. It may be contained. As a result, it is possible to provide various kinds of antiglare films, and it is possible to apply the antiglare film to more specialized and wide-ranging fields.

[0045]

The antiglare film according to the present invention has an average particle size of 1.5 to 1.5 in a silicone or acrylic transparent film material.
Since the transparent spherical particles having a refractive index of 1.4 to 1.6 in the range of 4.0 μm are contained in an appropriate amount, for example, 2.5 to 10 parts by weight, diffuse reflection of light is reduced and good antiglare property is obtained. Can be maintained and a low haze value can be exhibited. Therefore, if this is applied to a polarizing film or the like of various display devices, the visibility is improved and the industrial benefit is great.

[Brief description of drawings]

FIG. 1 is a diagram showing a cross-sectional structure of an antiglare film in an example of the present invention.

FIG. 2 is a diagram showing a cross-sectional structure of an antiglare film used as a comparative example of the antiglare film in one example of the present invention.

FIG. 3 is an external view showing an experiment for determining the degree of antiglare property.

FIG. 4 is a graph showing the relationship between the antiglare property of each mixed particle and haze when a silicone-based hard coat agent is used as a transparent film material.

FIG. 5 is a graph showing the relationship between the antiglare property and haze of each mixed particle when an acrylic hard coat agent is used as a transparent film material.

[Explanation of symbols]

 1 Polarizing Film 2 Transparent Film Material 3 Transparent Spherical Particles 10 Antiglare Film

[Table 4]

Front page continuation (72) Inventor Ayumu Ikemoto 3600 Amigazu, Oita, Komaki City, Aichi Prefecture Tokai Rubber Industry Co., Ltd. (72) Inventor Nobuhiro Nakajima 2-6-1, Nagasu-cho, Nishi Amagasaki City, Hyogo Prefecture Company Nard Institute (72) Inventor Noriko Matoba 2-6-1, Nagasu-cho, Nishi Amagasaki City, Hyogo Prefecture Nard Institute Ltd.

Claims (3)

[Claims] 1. The transparent film material contains transparent spherical particles having a refractive index of 1.4 to 1.6, and the average particle diameter of the transparent spherical particles is in the range of 1.5 to 4.0 microns. An antiglare film characterized by being present. 2. The antiglare film according to claim 1, wherein the ratio of the transparent spherical particles is in the range of 2.5 to 10 parts by weight with respect to 100 parts by weight of the transparent film material. 3. The transparent film material is formed of a silicone-based hard coating agent or an acrylic-based hard coating agent, and the transparent spherical particles are formed of any one or more of silica, silicone, melamine resin, and glass beads. It is formed, The anti-glare film of Claim 1 or 2 characterized by the above-mentioned.