JPH0557219B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a molded article, particularly a plate-shaped molded article, which has the appearance of stone such as marble and is widely used for furniture, fixtures, building materials, etc. [Prior art and its problems] Glass powder is added to resin such as epoxy resin (for example, JP-A No. 60-33243), and glass or glass is added to acrylate resin and metal hydroxide such as aluminum hydroxide. Addition of quality flour (for example, JP-A-61-243804, JP-A-62-132751)
There are many disclosures regarding artificial stones. These vitreous additives provide a stone-like appearance;
Alternatively, it is added to improve surface hardness and impart flame resistance, but if added in large amounts, the resin slurry becomes viscous and difficult to mold, while if added in small amounts, the above objectives cannot be fully achieved. Therefore, it is not satisfactory as a building material, furniture, or fixtures. The present invention solves these problems and provides a stone-like molded product, especially a plate-like molded product, such as quartz schist or marble, which has excellent surface hardness, flame resistance, etc., and has a pure white semi-transparent stone texture. It is. [Means for solving the problems] The present invention is a molded article whose main ingredients are an acrylate resin binder and a metal hydroxide filling, which is based on 100 wt% of the main ingredients and whose particle size is distributed in the range of 1 μm to 150 μm. Of this, 10wt% is coarse particles with a particle size of 50μm or more.
or 30 wt% of glass powder is added and dispersed therein, coarse glass powder is suitably unevenly distributed on one surface side of the molded body, and the glass powder is obtained by pulverization. It consists of powder with a complex polygonal shape and a fresh surface. In the present invention, the acrylate resin binder refers to resins such as ethyl acrylate and methyl methacrylate, or those obtained by copolymerizing these with resins such as polyethylene, polyester, and epoxy. Metal hydroxide filler is aluminum hydroxide,
It refers to magnesium hydroxide, aluminum calcium hydroxide, etc., and those with a particle size of 10-odd micrometers or less are used. In a total of 100 wt % of the metal hydroxide filler and acrylate resin binder, the metal hydroxide filler is contained in an amount of 50 to 70 wt %. Metal hydroxides bond well with acrylate resins, giving the molded product a certain degree of robustness, and when it comes into contact with flame, it evaporates moisture, prevents temperature rise due to its endothermic action, and improves flame retardancy. It is given by
If the amount is less than the above range, these effects cannot be fully exerted, and if it is too much, the amount of acrylate resin that is the binder becomes too small and the binding effect is not sufficiently distributed to each filler particle, and on the contrary, Deteriorates strength and hardness. Glass powder is soda lime based, which is cheap and easy to obtain.
Materials with ingredients such as borosilicate and aluminosilicate lime can be used. If glass powder with a particle size exceeding 150 μm is present in the molded product, cutting workability will be impaired.
The cut surface also lacks smoothness and the cutting blade is easily worn out. Furthermore, since the particle size is visually observed, the appearance loses its uniform appearance.
In order to facilitate the cutting process, it is preferable that the amount of glass powder exceeding 100 μm is 5 wt % or less of the entire glass powder. Glass powder having a particle diameter of less than 1 μm is not preferred because it tends to entrain fine air bubbles that are difficult to defoam when mixed with the acrylate resin binder. Therefore, the particle size of glass powder is 1μm to 150μm.
It is preferable that the glass powder exceeds 100 μm in an amount of 5 wt% or less of the total glass powder. The amount of glass powder added is 100wt% of the acrylate resin binder and metal hydroxide filler.
If it is less than 1wt%, it is insufficient to improve the surface hardness and flame resistance as mentioned above, and if it exceeds 10wt%, molding becomes difficult, so the content should be in the range of 1 to 10wt%, and more preferably in the range of 3 to 5wt%. do. When producing molded objects, a metal hydroxide such as aluminum hydroxide is kneaded into a stock solution of an acrylate resin binder, glass powder and a polymerization initiator are added and kneaded, and the mixture is poured into, for example, a flat box mold. . Attached Figure 1 is a side sectional view showing the cast state, of which 1 is the mold, 2 is the stock solution of acrylate resin binder, 3 is the glass powder with coarse particles larger than 50 μm, and 4 is the glass powder with the diameter less than 50 μm. It is a fine particle, and the fine powder metal hydroxide is omitted. However, if left as it is, the liquid viscosity will not increase for the initial few tens of minutes when the polymerization reaction is inactive, and during that time, based on Stokes' law, the larger the particle, the faster the rate will be in proportion to the square of its diameter. Sediment. FIG. 2 is a side cross-sectional view showing the hardened state of the molded body 2' after more than ten hours have passed after casting, and the fine glass powder 4 hardly settles and is distributed throughout the molded body 2'.
On the other hand, most of the coarse glass powder 3 is unevenly distributed on the lower surface side 5 of the molded body 2'. However, if the lower surface 5 of the molded body 2' is used as a surface for building materials or other materials, a hard surface rich in coarse and fine glass powder is formed, while fine glass powder is distributed throughout the molded body. Therefore, flame resistance is improved on both the front and back surfaces. The amount of coarse particles of 50 μm or more in the glass powder should be 10wt% to 30wt%; if it is less than 10wt%, uneven distribution and concentration on the glass surface side during molding will be insufficient, and if it exceeds 30wt%, the particles will be relatively fine. is too small, resulting in insufficient dispersion of the glass powder throughout the molded body, especially on the back side. Furthermore, since a large amount of glass powder is unevenly distributed on the surface, there is a significant difference in thermal properties between the front surface, which contains a large amount of glass powder, which has a low coefficient of thermal expansion relative to the acrylate resin, and the back surface, which contains a small amount of glass powder, and warping is likely to occur. The bond between glass powder and acrylate resin is not originally strong enough, but if the glass mass is crushed into a complex polygonal shape and the surface is made into a fresh surface with high surface activity, the bonding effect combined with the binding agent and the bonding agent can strengthen the bond. Join. In order to use the product in the surface active state, it is necessary to use it shortly after pulverization, or to store it in a sealed container or bag that blocks harmful reactive gases such as water vapor. The molded product obtained as described above has surface hardness,
It has excellent flame resistance, and furthermore, the molded body can be laminated and integrated with a foamed vitreous material, aerated concrete, or a lightweight aggregate aggregate to impart insulation properties and other properties. [Example] Polymethyl methacrylate stock solution and particle size of 10 μm
Knead the following aluminum hydroxide, and then
A predetermined amount of each of the soda lime glass powders W, X, Y, and Z having the particle size structure (distribution) shown in the table and FIG. Pour into a mold as shown in Figure 1, leave it to stand, maintain it at 50℃ or below and let it harden, then remove the frame and mix the various raw materials to a thickness of about 10 mm.
A plate-shaped specimen was obtained. The mixing ratio of raw materials for the test specimens is shown in Table 2. Glass powders W and X contain less than 1wt% of glass powders with a particle size of less than 1 μm and particles with a particle size of more than 150 μm, respectively, but if this amount is mixed, there will be no problem in implementation.
It is within the scope of the present invention. Glass powder Y is distributed on the fine grain side, with a particle size of less than 1 μm.
Glass powder Z has a particle size of 11 wt% and is distributed on the coarse grain side and has a particle size exceeding 150 μm in a proportion of 15 wt%, both of which are outside the scope of the present invention. During the molding, it is preferable that the mixed resin liquid has excessive fluidity and has good bubble removal.
The moldability is determined by visual inspection and feel during casting. Those with good moldability (A), those with moderate fluidity but with fine bubbles mixed in (B), those with high viscosity that are difficult to mold, or those with high viscosity. It was ranked as C, which is unacceptable. The surface appearance of the obtained test specimen was observed,
They were ranked as white semi-transparent and homogeneous (A), spots with glass grains and lacked a homogeneous texture (B), and bubbles mixed in and lacking a stone texture (C). Next, when cutting by sawing, the cut is smooth and the cut surface is smooth (A), the cut edge is chipped and the cut surface is not smooth (B), and the cut is not easy or impossible. Ranked as C. Furthermore, the surface was scratched with a knife edge, and the scratches were ranked as follows: extremely weak scratches (A), slightly thick and deep scratches (B), and easily scratched and thick and deep scars (C). In addition, apply a lighter flame from the surface to the edge.
When applied for 30 seconds, the area remains slightly discolored (A), the area has a slight discoloration and the edges peel off slightly (B), the area has significant discoloration and a swollen appearance. It was ranked as (C) where protrusions were observed and peeling of the edges was also noticeable. These results are shown in Table 2. The products of the present invention according to Examples 1 to 4 were ranked A or partially B in all tests, and were generally good. Comparative Example 1 added glass powder distributed on the fine grain side, Comparative Example 2 added glass powder distributed on the coarse grain side, Comparative Examples 3 and 4 added glass powder in an excessive amount, Comparative Example 5 No glass powder was added, and all of the comparative examples were ranked C, clearly indicating that they were inferior to the examples.

【table】

〔Effect of the invention〕

According to the present invention, the hardness (scratch resistance) of the molded object,
It is suitable for use as a material for building materials, furniture, fixtures, etc., as it can improve flame resistance, provide a deep stone-like texture, and be easily cut.

[Brief explanation of the drawing]

1 and 2 are side sectional views showing one manufacturing means of the molded body, and FIG. 3 is a graph showing the particle size distribution of glass powder. 1... Molding frame, 2... Methyl methacrylate stock solution, 3... Coarse glass powder, 4... Fine glass powder.

Claims (1)

[Scope of Claims] 1. A molded article whose main ingredients are an acrylate resin binder and a metal hydroxide filler, the main ingredients being
Molding characterized by adding and dispersing 1 to 10 wt% of glass powder, which is distributed in a particle size range of 1 μm to 150 μm, of which 10 wt% to 30 wt% is coarse particles with a particle size of 50 μm or more, based on 100 wt%. body. 2. The molded product according to claim 1, characterized in that coarse glass powder is unevenly distributed on one surface side of the molded product. 3. The molded article according to claim 1 or 2, wherein the glass powder is a complex polygonal powder obtained by pulverization and has a fresh surface.