JP3130163B2 - New surface hardness modified plate and its manufacturing method. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modified surface hardness plate which is required to have a certain surface hardness and is suitable for use as a partition plate, a fall prevention plate for a highway, a daylighting material, and the like, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, a synthetic resin plate such as a polycarbonate plate (PC) or a vinyl chloride plate (PVC) whose surface is hard-coated has been used for the above applications. These synthetic resin plates have the advantage that the surface has high abrasion hardness of the Taber type, but have the following problems.

[0003]

That is, by directly hard-coating the above synthetic resin plate, the abrasion hardness of the Taber type is improved, but the indentation type scratch hardness such as pencil hardness is improved. There is a problem that the effect is not so great because the influence of the hardness of the substrate is large.

The present invention has been made in view of the above problems, and an object of the present invention is to improve the surface hardness of not only the surface abrasion hardness but also the scratch hardness such as pressing, and a method of manufacturing the same. It is to provide.

[0005]

In order to achieve this object,
The surface hardness modified plate according to claim 1 of the present invention is a laminate of a hard coating layer and a coating layer having a thickness of 3 μm or more made of unmodified polymethyl methacrylate resin (hereinafter referred to as PMMA resin) on the surface of a synthetic resin substrate. It is made by integrating to improve pencil hardness. PMM used for this
Resin A has the hardness of this resin (3H or more in pencil hardness)
It is not a resin having low hardness such as a modified PMMA resin usually used for laminating PC or PVC. However, it is difficult to make such a PMMA resin into a film, and even if it is made, it is difficult to handle such as lamination. Therefore, the production method according to claim 2 of the present invention is characterized in that a two-layer film obtained by coating a release film with a PMMA resin solution on a surface of a synthetic resin substrate is integrated by fusion, and then the release film is formed. And remove PM
The present invention is characterized in that the hard coat layer, the PMMA resin layer, and the synthetic resin substrate are integrated by applying a thermosetting resin type hard coat agent to the surface of the MA resin layer.

[0006]

The surface hardness modified plate of the present invention is a "coating resin layer" (hereinafter referred to as a PMMA resin layer) formed by laminating a coating layer of a non-modified PMMA resin having a thickness of 3 μm or more on the surface of a synthetic resin substrate. ) Is provided to improve the pencil hardness, which is the scratch hardness of the indentation type. Further, by applying a hard coat layer using a hard coat agent on the PMMA resin layer, a sufficient Taber type surface wear hardness can be obtained. Thus, by providing the PMMA resin layer on the substrate, the pencil hardness can be improved by several ranks as compared with the case where the hard coat treatment is directly performed.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing one embodiment of the surface hardness modified plate of the present invention. As shown in the drawing, this surface hardness modified plate has a PMMA resin coating layer 4 formed on a surface of a synthetic resin substrate 1 by heat fusion. A hard coat layer 3 formed by applying a hard coat agent on the surface of a PMMA resin layer 2 formed integrally by adhesion is shown as a three-layer structure, and depending on the application, a PMMA resin layer is formed on both surfaces depending on the application. And a five-layer structure in which a hard coat layer is laminated and integrated.

As the synthetic resin substrate, a polycarbonate, vinyl chloride or other thermoplastic resin having a low surface hardness and having various thicknesses and hues is used.

The PMMA resin layer 2 is basically made of a PMMA resin having excellent hardness which is not modified with rubber or the like. This layer is preferably formed in a uniform plane. If the thickness is too small, it does not contribute to the surface hardness which is the gist of the present invention, so it is 3 μm or more, preferably 5 μm or more. Since it can be obtained, the film thickness is selected according to the application. When the synthetic resin substrate has poor weather resistance like a polycarbonate plate, this layer may contain an ultraviolet absorber or the like.

The hard coat layer 3 is formed of a hard coat agent of silicone, melamine resin, polyurethane, phosphazene resin, or other thermosetting resin depending on its use.

The above-mentioned three-layer and five-layer surface hardness modified plates are manufactured, for example, by the following method. First, P
A coating material is prepared by dissolving the MMA resin in a solvent (toluene, xylene, ethyl acetate, etc.). And this paint is P
The transfer film shown in FIG. 2 is formed by uniformly coating the entire surface of the release film 5 such as ET and removing the solvent by drying. Next, the above-mentioned transfer film (FIG. 2) is laminated on the synthetic resin substrate 1 with the PMMA resin coating layer 4 on the lower side, and is integrated by thermocompression bonding using, for example, a hot press machine. By applying a hard coat treatment agent of a thermosetting resin type to the surface of the PMMA resin layer 2 and performing a hard coat treatment, a surface hardness modified plate having the hard coat layer 3 integrated on the surface is obtained.

By changing the thickness of the PMMA resin coated on the release film and the thickness and type of the hard coat treatment layer, the surface hardness modified plate can easily attain the required wear hardness and scratch hardness according to the application. can get.

Table 1 below shows the test pieces of the present invention measured and compared with the comparative examples and the synthetic resin substrate in terms of pencil hardness and haze after Taber abrasion. The test piece of the present invention is formed on a polycarbonate (PC) having a thickness of 2.5 mm and a thickness of 8 μm.
m PMMA resin coating layer was formed on one side 38
μm PET film was heat-sealed and transferred such that the PMMA resin coating layer was on the PC surface side, and then a phosphazene resin (PP
Z) is a test piece having a three-layer structure in which a hard coat layer is integrated by applying Z) to a dry thickness of 10 μm. Comparative Example 1 is a two-layer structure piece of PC and PMMA resin layer, Comparative Example 2
And 3 are two-layer pieces of PC and PPZ. The pencil hardness was measured according to JIS-K-5400, and the Taber abrasion and haze were measured according to JIS-K-6735.

[0014]

[Table 1]

As shown in Table 1, the test pieces were two times more than those of Comparative Examples 2 and 3 in which a polycarbonate plate was directly hard-coated.
It can be seen that it has a pencil hardness of ~ 3H. In addition, the haze after Taber abrasion shows the same value, which indicates that there is no influence of the PMMA resin layer. Therefore, it can be seen that the surface hardness modified plate of the present invention can have a pencil hardness several ranks higher than that obtained by directly hard coating the substrate.

[0016]

As is apparent from the above description, the surface hardness modified plate of the present invention has a structure in which a PMMA resin layer and a hard coat layer are integrated on the surface of a synthetic resin substrate.
By providing the PMMA resin layer, it is possible to obtain a surface hardness modified plate having high pencil hardness and Taber abrasion hardness, both of which were difficult to obtain with the hard coat layer alone. Also, since the PMMA resin layer is integrated by transferring the PMMA resin coated layer to the substrate, it is difficult to form a PMM into a film.
A resin can be easily laminated and integrated.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a surface hardness modified plate of the present invention.

FIG. 2 is a sectional view showing an example of a PMMA resin transfer film of the present invention.

[Explanation of symbols]

 Reference Signs List 1 synthetic resin substrate 2 PMMA resin layer 3 hard coat layer 4 PMMA resin coated layer 5 release film

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Morihiro Seko 2-3-1-13 Azuchi-cho, Chuo-ku, Osaka City Examiner at Takiron Co., Ltd. Yurika Ashihara (56) References JP-A-5-69698 (JP, A JP-A-5-50798 (JP, A) JP-A-5-104898 (JP, A) JP-A-5-139093 (JP, A) JP-A-57-162730 (JP, A) 27703 (JP, U) Special Table 62-502623 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 1/00-35/00 B05D 1/00-7/26 B44C 1/16-1/175

Claims (2)

(57) [Claims] 1. A surface hardness modified plate formed by laminating and integrating a hard coating layer having a thickness of 3 μm or more of an unmodified polymethyl methacrylate resin on the surface of a synthetic resin substrate to improve pencil hardness. . 2. A polymethyl methacrylate resin coated film comprising a release film coated with a polymethyl methacrylate resin solution on a surface of a synthetic resin substrate is integrated by fusion, and then the release film is peeled off. Then, a method for producing a surface hardness modified plate, wherein a hard coat layer is formed by applying a thermosetting resin type hard coat agent to the surface of a polymethyl methacrylate resin layer.