JP5208046B2 - Manufacturing method of molded body - Google Patents

Description

  The present invention relates to a molded body having a pattern, a flame retardant function, and the like on the surface.

Artificial marble is a molded body having a pattern and a flame-retardant function on the surface. Artificial marble is used for kitchen top plates, various counter materials, wall materials, partition materials, furniture face plates, and the like, and the surface is required to have a design. Particularly in recent years, there has been an increasing demand for the combination of colors and the spread of design.
A transfer method is known as a method for applying a pattern to the surface of artificial marble (see Patent Documents 1 and 2, etc.). In Patent Document 1, with a transfer sheet having dye ink disposed in a casting mold, a polymerizable composition is injected into the mold and cured to produce an artificial marble having a pattern transferred to the surface. A method is disclosed. In Patent Document 2, using a vacuum forming method, an uncured reinforced plastic is poured into a mold and cured in a state where a transfer sheet having a pattern is arranged on the inner surface of the molding mold, and the pattern is transferred to the surface. A method for obtaining a molded plastic product is disclosed. In addition, a method is disclosed in which an uncured reinforced plastic and a transfer sheet are superposed and heated and pressed using a heating plate, a heating roll, or the like to obtain a plastic molded body having a pattern transferred to the surface.

When this type of plastic molded body with a pattern is contaminated, the surface is scraped and reused. However, if the depth of penetration of the pattern is shallow, the pattern disappears due to grinding. There is a problem that the life of the body is shortened.
Artificial marble is also required to have functions such as flame retardancy and water repellency. From the viewpoint of reducing the cost of flame retardants and water repellants, efficient use of flame retardants and water repellants only on the surface of the artificial marble is not possible. There is a need for a method to keep it.
As a technique using ultrasonic vibration, there is known a method of applying ultrasonic vibration at the time of injection molding of a polycarbonate resin product (see Patent Document 3, etc.), but when transferring an object to be transferred to a polymerizable component. No technology that uses ultrasonic vibration is known.

JP-A 64-14008 Japanese Patent Application Laid-Open No. 52-21073 JP-A-2005-290320

  An object of the present invention is to extend the life of a pattern by causing the pattern formed on the surface of the molded body to enter the deep part. It is another object of the present invention to provide a molded product having a wide range of color combinations and designs, and to efficiently impart functions such as flame retardancy and water repellency only to the surface layer of the molded product.

The above-mentioned problems are solved by the following present invention [1] or [2].
[1] A method for producing a molded body in which an uncured raw material containing an organic polymerizable component (A) is prepared and cured, and the transferred object (C) is in contact with the surface of the raw material A method for producing a molded body in which the raw material is vibrated and the transferred material (C) is transferred to the raw material, and then the polymerizable component (A) is polymerized to cure the raw material.
[2] A method for producing a molded body in which an uncured mixed raw material containing an organic polymerizable component (A) and an inorganic filler (B) is prepared and cured, and transferred onto the surface of the mixed raw material A molded body in which the mixed raw material is vibrated while the product (C) is in contact therewith, the transferred material (C) is transferred to the mixed raw material, and then the polymerizable component (A) is polymerized to cure the mixed raw material. Production method.

  ADVANTAGE OF THE INVENTION According to this invention, the molded object with a pattern pattern in which the lifetime of the pattern pattern was prolonged is provided. In particular, when the pigment is infiltrated, since the color of the pigment is added to the background color of a normal molded body, the effect of spreading the color combination and design is also produced. In addition, functions such as flame retardancy and water repellency can be efficiently imparted only to the surface layer of the molded body.

  Examples of the polymerizable component (A) used as a raw material for the molded article of the present invention include acrylic acid, methacrylic acid, acrylic esters, methacrylic esters, acrylonitrile, methacrylonitrile, styrene, α-methylstyrene, divinylbenzene, acetic acid. Examples include α, β-ethylenically unsaturated monomers such as vinyl, acrylamide, and methacrylamide; unsaturated polyester resins, liquid epoxy resins, liquid mixtures that give polyurethane, liquid rubbers, liquid silicon rubbers, and liquid phenol resins.

When the molded body is artificial marble, the polymerizable component (A) may be a polymerizable component (A1) mainly composed of methyl methacrylate in order to improve the physical properties and texture of the artificial marble. preferable.
Examples of such polymerizable component (A1) include methyl methacrylate (hereinafter referred to as MMA), a monomer mixture of MMA and another vinyl monomer having one vinyl group in the molecule, or MMA. Or the mixture (henceforth polymerizable syrup) of the said monomer mixture and the (co) polymer in which some of these monomer components (co) polymerized are mentioned. The composition of the monomer mixture is, for example, MMA 70% by mass or more and vinyl monomer 30% by mass or less. Examples of vinyl monomers include styrene, vinyl acetate, acrylonitrile, ethyl methacrylate, butyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, ethyl acrylate, acrylic Examples include α, β-ethylenically unsaturated compounds such as methyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and lauryl acrylate. These can also be used independently and can also use 2 or more types together.

  In the present invention, an uncured mixed raw material containing an organic polymerizable component (A) and an inorganic filler (B) is used in place of the uncured raw material containing the organic polymerizable component (A). be able to. Such a mixed raw material is suitable for the production of artificial marble. The polymerizable component (A1) mainly composed of MMA as the polymerizable component (A) is preferably used in a range of 20 to 80% by mass based on the mass of the mixed raw material. More preferably, it is 30-70 mass%. When the content is 20% by mass or more, artificial marble can be easily molded, which is preferable in terms of texture, appearance, and physical properties. Moreover, in the case of 80 mass% or less, a flame retardance improves preferably from the point on a texture and an external appearance.

  The polymerizable component (A1) is preferably a polymerizable syrup. In order to produce polymerizable syrup, [1] a method of polymerizing a part of MMA and stopping the polymerization in the middle, or [2] a polymer mainly composed of MMA preliminarily polymerized by bulk polymerization or suspension polymerization And the like are used in a monomer mainly composed of MMA. The viscosity of the polymerizable syrup at 25 ° C. is preferably about 20 to 300 cp (centipoise).

  Examples of the inorganic filler (B) used in the present invention include aluminum hydroxide, magnesium hydroxide, calcium hydroxide, calcium carbonate, powder talc, powdered quartz, fine silica, diatomaceous earth, gypsum, powdered glass, clay mineral substance, powder Examples include chalk, marble, limestone, colloidal asbestos, aluminum stearate, mullite, calcium silicate, and aluminum silicate. When the molding is artificial marble, at least one selected from aluminum hydroxide, magnesium hydroxide, calcium hydroxide, and calcium carbonate is preferable among them, and aluminum hydroxide is particularly preferable among them. Since these hydroxides release crystal water at a high temperature, they effectively work to improve the flame retardancy of artificial marble and contribute to the improvement of workability.

  As the inorganic filler (B), those having a number average particle diameter in the range of 1 to 150 μm are usually used. When the number average particle size is 1 μm or more, the moldability is improved, and the design of the resulting molded product tends to be unique to artificial marble, and when the number average particle size is 150 μm or less, the inorganic filler becomes a matrix. Evenly distributed. The number average particle diameter is more preferably 20 to 80 μm.

  The inorganic filler (B) is preferably used in the range of 20 to 80% by mass based on the mass of the mixed raw material. More preferably, it is 30-70 mass%. When content of an inorganic filler (B) is 20 mass% or more, it is preferable from the point of an external appearance and a texture, and also a flame retardance improves. Moreover, when it is 80 mass% or less, shaping | molding becomes easy and it is preferable from the point of an external appearance and a texture. The surface of the inorganic filler (B) can be treated with, for example, a silane coupling agent, a titanate coupling agent, a steering acid, or the like.

  The uncured mixed raw material is prepared by stirring a predetermined amount of the polymerizable component (A) and the inorganic filler (B) with a mixer. Various additives can be added to such an extent that the appearance of the molded body or artificial marble obtained after polymerization and curing is not impaired. Examples of the additive include an ultraviolet absorber, a flame retardant, an antibacterial agent, a mold release agent, a fluidizing agent, and a thickener. Moreover, coloring pigments, such as an inorganic pigment and an organic pigment, can also be added. Examples of the inorganic pigment include titanium white, zinc white, lead white, carbon black, bengara, vermilion, cadmium red, yellow lead, ultramarine blue, cobalt blue, and cobalt purple. Examples of organic pigments include azo, triphenylmethane, quinoline, anthraquinone, and phthalocyanine pigments.

  Moreover, in the uncured raw material and the mixed raw material (hereinafter, both are collectively referred to as “mixed raw material”), a cured product containing the component (A) and the component (B) at a ratio approximately the same as the above ratio. Can be contained in a particle of about 0.1 to 12 mm. In this case, a so-called stone-like molded body or artificial marble is obtained.

Examples of the transfer object (C) used in the present invention include pattern / pattern forming components such as pigments and dyes, and function-imparting components such as flame retardants and water repellents. These pattern / pattern forming components are usually used by being mixed in ink, paint vehicle or the like and applied as a pattern or the like on the surface of the transfer sheet.
The method of bringing the material to be transferred (C) into contact with the surface of the uncured (mixed) raw material is determined in consideration of the molding method of the molded body or artificial marble. As a molding method, a known method such as a batch cast molding method or a continuous cast molding method can be employed. In the case of batch cast molding, place the transfer sheet on the inner surface of the mold with the surface with the pattern on the inside, or form the pattern directly on the inner surface of the mold and place it inside the mold. By introducing the uncured (mixed) raw material, the transfer object (C) can be brought into contact with the surface of the (mixed) raw material. The function-imparting components such as the flame retardant and the water repellent are used by applying these components to the surface of the transfer sheet in the same manner as the pattern forming component or by directly applying them to the inner surface of the mold.

In the case of the continuous cast molding method, the transfer sheet is placed on the opposite surface of at least one of the two stainless steel belts arranged to face each other with the surface having the design pattern on the non-belt surface side, or Forming a pattern directly on the opposite surface of a stainless steel belt, and pouring an uncured (mixed) raw material between the belts to bring the transferred material (C) into contact with the surface of the (mixed) raw material Can do. The function-imparting components such as a flame retardant and a water repellent are used by applying these components on the surface of the transfer sheet in the same manner as the pattern forming component or by directly applying them on the opposite surface of the belt. Further, on the outer surface of one stainless steel belt, the transfer sheet is arranged with the surface with the pattern on the non-belt surface side, or the pattern is directly formed on the opposite surface of the stainless steel belt, After pouring uncured (mixed) raw material, the (mixed) raw material can be covered with a film or the like.
A polyvinyl alcohol film etc. are mentioned as a transfer sheet. The thickness is preferably 10 to 100 μm, and more preferably 25 to 60 μm.
The uncured (mixed) raw material is held in substantially the same shape as that after curing by charging it into a mold or pouring between two belts or between a belt and a film.

In the present invention, the (mixed) raw material is vibrated in a state where the transfer target (C) is brought into contact with the surface of the uncured (mixed) raw material. The method of imparting vibration is not limited. For example, [1] a method of bringing a vibrating body into contact with a molding die or belt containing (mixed) raw material (mixing) and vibrating the raw material, [2] a molding die or belt, etc. Is placed in the liquid, and the (mixed) raw material is vibrated using this liquid as a medium. In the method [1], for example, a vibration plate made by Kaijo Co., Ltd. can be installed on the back surface of the belt to vibrate the (mixed) raw material. Further, in the method [2], for example, an insertion vibrator made by Kaijo Co., Ltd. can be installed in the liquid.
Although the frequency of a vibrating body is not limited, For example, they are 1 kHz-1 MHz. The application time of vibration is not limited, but is, for example, about 1 second to 1 minute. By this vibration operation, the transfer object (C) penetrates from the surface of the uncured (mixed) raw material to the inside and is transferred.

After the transferred object (C) is transferred to the uncured (mixed) raw material, the uncured (mixed) raw material is cured by heating and polymerizing the polymerizable component (A). Artificial marble is produced.
Examples of the molded body include a sheet-like product and a bowl-like product. Examples of the artificial marble include sheet-like materials and bowl-like materials. In the case of a sheet-like material, the thickness is preferably 1 to 50 mm. Also when it is a bowl-shaped thing, it is preferable that the thickness is 1-50 mm.

In the polymerization curing, a polymerization initiator is usually used. Preferred examples of the polymerization initiator include tertiary butyl peroxymaleic acid, benzoyl peroxide, cumene hydroperoxide, tertiary butyl hydroperoxide, dicumyl peroxide, acetyl peroxide, lauroyl peroxide, and azobisisobutyronitrile. As mentioned. When polymerization and curing at room temperature, for example, peroxides and amines, peroxides and sulfinic acids, combinations of peroxides and cobalt compounds, peroxyl compounds such as tertiary butyl peroxymaleic acid and glycol dimercaptoacetate A combination with a mercaptan compound is a preferred example.
It is preferable that the compounding quantity of a polymerization initiator is 0.05-10 mass parts with respect to 100 mass parts of polymeric components (A).

  The obtained molded body or artificial marble may be used as it is, and a clearer appearance with a high commercial value can be obtained by grinding the surface. The surface grinding is preferably performed at a depth of 0.1 mm or more.

[Example 1]
An ink containing a titanium oxide pigment (pigment concentration: 35% by mass) was applied onto a 40 μm thick polyvinyl alcohol film to draw a pattern and dried. This film was affixed to the bottom surface of a stainless steel tray having a length of 83 mm and a width of 160 mm coated with a thin layer of polyethylene glycol with the ink application surface facing up. The amount of pigment used calculated from the charged amount was 1 × 10 ⁻⁷ parts by mass / mm ² .
36.6 parts by mass of polymerizable syrup composed of a mixture of 20% by mass of polymethyl methacrylate and 80% by mass of MMA, 62 parts by mass of aluminum hydroxide powder having a number average particle diameter of 52 μm by laser diffraction / scattering method, 0.4 parts by mass of ethylene glycol methacrylate, 0.7 parts by mass of tertiary butyl peroxymaleic acid, and 0.1 parts by mass of carbon black were stirred with a mixer and defoamed in a vacuum vessel to obtain a black slurry. . To this slurry, 0.1 part by mass of glycol dimercaptoacetate and 0.1 part by mass of deionized water were added, stirred, and poured into the stainless steel tray described above. This stainless steel tray was floated on an ultrasonic cleaning tank (Nippon Seiki Seisakusho, frequency 28 KHz, 100 W) filled with water, and ultrasonic vibration was applied for 20 seconds. Thereafter, the stainless steel tray was taken out from the ultrasonic cleaning tank, kept warm and left for 30 minutes to cure the resin. After curing, a cured product having a thickness of 12 mm was taken out from the stainless steel tray, and the film was peeled off to obtain an artificial marble having a pattern transferred to the surface.
When the obtained artificial marble was cut with a circular saw and the cross section thereof was visually confirmed, it was confirmed that the color material had penetrated from the surface to a depth of 3 mm. The surface of this artificial marble was polished 0.5 mm, but the pattern did not disappear.

[Example 2]
In Example 1, on a polyvinyl alcohol film, cresyl diphenyl phosphate as a flame retardant instead of the ink (Daihachi Chemical Industry Co., Ltd., trade name CDP) and 0.003g per 1 cm ² coated. Other conditions were the same as in Example 1 to obtain an artificial marble.
The surface of this artificial marble was polished by 0.5 mm, and the surface was analyzed by fluorescent X-ray. As a result, the presence of phosphorus element was confirmed.

[Comparative Example 1]
In Example 1, the ink containing the titanium oxide pigment was replaced with a color magic containing a dye, and no ultrasonic vibration was applied. Other conditions were the same as in Example 1 to obtain an artificial marble.
When this artificial marble was cut with a circular saw and the cross section was visually confirmed, it was confirmed that the coloring material penetrated into a very thin layer on the surface. The surface of this artificial marble was polished 0.3 mm, but the pattern did not disappear. Thereafter, when the surface was further polished by 0.2 mm, the pattern disappeared.

[Comparative Example 2]
An artificial marble was obtained in the same manner as in Example 1 except that no ultrasonic vibration was applied.
When this artificial marble was cut with a circular saw and the cross section thereof was visually confirmed, the penetration of the coloring material was not confirmed. When the surface of this artificial marble was polished 0.3 mm, the pattern disappeared.

Claims (5)

  A method for producing a molded body in which an uncured raw material containing an organic polymerizable component (A) is prepared and cured, and the transferred material (C) is brought into contact with the surface of the raw material. A method for producing a molded article, in which vibration is applied to transfer the transferred material (C) to a raw material, and then the raw material is cured by polymerizing the polymerizable component (A).   An uncured mixed raw material containing an organic polymerizable component (A) and an inorganic filler (B) is prepared, and the molded product is cured, and the transferred material (C ) In contact with the mixed raw material, the transferred material (C) is transferred to the mixed raw material, and then the polymerizable component (A) is polymerized to cure the mixed raw material.   The molded body is artificial marble, and the uncured mixed raw material is 20 to 80% by mass of a polymerizable component mainly composed of methyl methacrylate as an organic polymerizable component (A) and an inorganic filler (B) 20 The manufacturing method of the molded object of Claim 2 which is a mixture containing -80 mass%.   The method for producing a molded article according to any one of claims 1 to 3, wherein the transfer object (C) is a pigment.   The method for producing a molded article according to any one of claims 1 to 3, wherein the transferred object (C) is a flame retardant.