JPS63207610A - Manufacture of artificial marble - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Technical Field of the Invention) The present invention relates to a method for producing artificial marble, and more specifically, the present invention relates to a method for producing artificial marble, and more specifically, the present invention relates to a method for producing artificial marble, and more specifically, a method for producing artificial marble, which essentially includes cellulose fibers, organic or inorganic fibers, inorganic fillers with a refractive index of 2.0 or less, etc. This relates to a method for producing artificial marble, which is characterized in that the element is formed into a sheet using a wet papermaking method or a method similar to it, impregnated with a synthetic resin and dried, and then laminated in multiple layers and hot-press molded. be.

(Prior art and problems) Conventionally, as a manufacturing method for artificial marble or sheets with a marble appearance, a marble pattern is created on the surface of a base paper for decorative laminates containing titanium oxide, which is called synthetic resin base paper for decorative laminates (commonly known as titanium paper). After printing, the surface layer is impregnated with a thermosetting resin such as melamine resin and dried, and several sheets of unbleached kraft paper called core paper impregnated with phenolic resin and dried are layered underneath. So-called high-pressure melamine decorative boards molded under heat and pressure, thermoplastic acrylic resin monomers and polymers such as methyl methacrylate resin, and inorganic fillers such as aluminum hydroxide mixed together and then extruded into a plate shape, or A known technique is one in which an inorganic filler is kneaded into a thermosetting resin such as an unsaturated polyester resin, and then molded and cured. However, each of these prior art techniques has been found to have significant drawbacks. In other words, the so-called high-pressure melamine decorative board, which is made by placing a marble pattern printed on the surface of titanium paper and laminating it with a core paper and heat-pressing it, looks like pseudo-marble, but it is an imitation of only the surface. It cannot match the inorganic texture, transparency, and weight of reeds and natural marble. On the other hand, products made by kneading inorganic fillers with thermoplastic resin monomers and polymers and extrusion molding have an inorganic texture.
Although its transparency and weight are comparable to natural marble, it has some drawbacks, such as its physical properties such as impact resistance, heat resistance, and abrasion resistance, and the board cannot be made very thin. Ta. More thermoset unsaturated? Products obtained by mixing and molding an inorganic filler with a polyester resin and curing the resin had disadvantages such as poor inorganic texture, transparency, and weight, and the thickness of the resin plate was too thin and did not age well.

As mentioned above, the manufacturing methods of artificial marble using conventional techniques each have drawbacks, such as inorganic texture, transparency, weight, etc.
Furthermore, there was no impossible method for manufacturing artificial marble that had both physical properties and could make the board considerably thinner.

(Means for Solving the Problems) The present inventors have made extensive studies to solve the problems of the prior art, and have found that the texture is as good as that of natural marble, and the texture is far superior to that of natural marble. The present invention has been completed as a method for manufacturing artificial marble that has both physical properties.

That is, A: 20 to 80% by weight of cellulose fibers, B: 2 to 40% by weight of organic or inorganic fibers other than cellulose,
C: A mixture mainly containing 10 to 70% by weight of an inorganic filler with a refractive index of 2.0 or less is made into an aqueous dispersion, formed into a sheet by a wet papermaking method or a similar method, and then a synthetic resin (hereinafter referred to as After being impregnated with impregnating resin (referred to as impregnating resin) and dried if necessary, a plurality of pieces are laminated and hot-press molded to obtain artificial marble. When the sheet-like material is impregnated with a synthetic resin, the amount of the synthetic resin is in the range of 100 to 150 parts by weight per 100 parts by weight of the sheet-like material, so that the amount of the synthetic resin is -
Article 11: It is desirable to do so. Wet paper-making method or similar method has the effect of imparting strength and supporting inorganic filler when it is made into a sheet, but if the weight is less than 20%, the strength of the sheet-like material will be weak. Too much, #fat impregnated,
Breakage occurs during hot press molding, which is undesirable. On the other hand, if it exceeds 80% by weight, the strength may be problematic or the design properties such as inorganic texture and transparency may be poor, which is not preferable. Examples of these cellulose-based fibers include cotton linters/mother linters, bleached sulfite noguru f (NH2F, LBSP), bleached kraft linters (NBKP, LBKP), and dissolution/gulp (DP). However, it is not limited to these. In addition, the inclusion of organic or inorganic fibers other than cellulose fibers (hereinafter referred to as non-cellulose fibers) significantly improves the physical properties of the molded plate, such as dimensional stability, abrasion resistance, impact resistance, and heat resistance. However, if the weight is less than 2 weight, the effect of improving physical properties is more than 1 ts.
It is unfavorable that the interlaminar strength as a sheet-like material is weak, and it is easy to break during resin impregnation and hot-press molding. These non-cellulose fibers include long glass fibers (chopped stracid), short glass fibers (microglass), alumina silica fibers (ceramic fibers), alumina fibers, mullite fibers, quartz fibers, high silicate glass fibers, fused silica fibers, Phosphate fiber, rock wool, potassium titanate fiber, zirconia fiber, calcium sulfate fiber, ? Inorganic fibers such as lon fiber, 4-lyester, nylon, vinylon, etc.
PVA rayon, Horiklars PP-77 Mido,
Examples include, but are not limited to, synthetic organic fibers such as kynol fibers. Among these, it has particularly good water dispersibility, and is colorless and transparent.

Synthetic inorganic fibers are good because they are effective in all physical properties such as dimensional stability, abrasion resistance, heat resistance, impact resistance, etc. Among them, the average fiber diameter should be 10μ or less, and the average a fiber length should be 8■→÷~. 10
0μ is desirable. In addition, C: By adding an inorganic filler with a refractive index of 2.0 or less (hereinafter simply referred to as an inorganic filler), when a synthetic resin is made into a plate, it has a glassy feel (light, soft, and lacks depth). ), cancel out, heavily,
It can give a hard and deep inorganic texture. These inorganic textures are a very important element in artificial marble, and without it, the product would simply be a glass plate, and its commercial value would drop significantly. 10
If it is less than 70% by weight, the inorganic texture will be insufficient, and if it is more than 70% by weight, the strength of the sheet will be weak and it will be easy to break during resin impregnation, hot pressure molding, etc.

These inorganic fillers include, for example, silica, silica sand, diatomaceous earth, kaolin, noisite, montmorillonite, bentonite, zeolite, phosphate rock, dianepore, gigite, geekite, clayey mica (sericite, illite), permicrylite, Natural minerals such as acid clay, pottery stone, waxite, feldspar, limestone, wollastonite, gypsum, dolomite, magnesite, talc, water-insoluble metal hydroxides such as aluminum hydroxide, magnesium hydroxide, calcium hydroxide, Calcium silicate hydrates such as topelmonite and xonotrite, various oxide hydrates such as calcium aluminate hydrate and calcium sulfoaluminate hydrate, alumina, silica, hydrated silicic acid, spherical silica, and magnesia. , zinc oxide.

Examples include powders of synthetic inorganic materials such as spinel, synthetic cordierite, synthetic mullite, synthetic zeolite, synthetic calcium carbonate, calcium phosphate, barium sulfate, and magnesium carbonate, or fine fibrous materials with a length of approximately 100 μm or less. Note that whisker-like substances, scale-like substances, and flake-like substances are also included. It is a necessary condition that these inorganic fillers have a refractive index of 2.0 or less. refractive index is 2
．． If the value exceeds 0, it will have a transparent feel when hot-press molded.
Undesirable. However, for the purpose of controlling transparency and color tone, inorganic pigments such as titanium oxide having a refractive index exceeding 2.0 can be used within a range of 5% by weight. In addition, inorganic fillers vary in specific gravity and color, but one or two types may be used depending on the texture, color, transparency, etc. of the desired artificial marble.
In addition, if necessary, water-soluble urea resin, melamine resin, cationized starch, CMC1I lyamide polyamine epichlorohydrin resin, /liimine resin,
Wet paper strength agents such as water-soluble acrylic resins, and anionic 4-rimers as polymer flocculants (e.g., salts of partial hydrolysates such as sodium 4-lyacrylate, -lyacrylamide, and maleic acid copolymers) salt), cationic I remer (e.g. /partial hydrolyzate of lyacrylamide, etc.)
.

Natural stringy polymers such as nonionic polymers (eg, lyacrylamide, 4-rivinyl alcohol, P]

In addition, other sulfuric acid, sodium chloride, sodium aluminate, sodium phosphoric acid, and silica! Auxiliary agents such as ring agents, and also molybdenum red, Pen 115, #l as a pigment.
Inorganic pigments such as Co/Gult purple, Cobalt green, Co/Gult blue, Prussian blue, or insoluble azo type, Azo lake type, 7
Talocyanine series, triphenylmethane series, quinacridone series, thioindi-f series, dioxazine series, perinone perylene series, isoindolinone series, fluoropine series, chandraquinone series, pyrocholine series, coupled azo series, condensed reduced azo series, metals Organic pigments such as complex salts can also be used.

These constituent elements are dispersed in water to form an aqueous dispersion, which is then made into paper by a wet paper-making method or a method similar thereto, and dried to form a sheet. Here, the wet paper making method or a method similar thereto means, for example, p-filter paper in the form of a strip, a cylinder, a square shape, etc.
After pouring the auxiliary aqueous dispersion onto a passing medium such as a passing cloth or a passing plate, or after sandwiching the dispersion between these passing mediums, the dispersion may be subjected to a natural passing process or a vacuum passing process. It is a general term for a method of forming a sheet into a sheet by passing it through a vt.

As a method for continuously forming these sheets, there are conventionally known wet paper machines such as a Fourdrinier type one-circle-mesh type, a circular-mesh 7-t machine set, and an inclined wire-mesh type.

The dry sheet thus obtained is impregnated with an impregnating resin and dried. Examples of impregnating resins include phenol, melamine, area, unsaturated d-rester, polyester, diallyl phthalate, alkyd, polyimide, etc. Thermosetting resins such as lyamide, imide, furan, etc. are preferable, but other materials can also be used, as long as they are impregnated with synthetic resin monomers, etc., and then flowed under heat and pressure to cause a curing reaction and finally be made into a resin board. Can be used.

It may be a water dispersion type, an organic solvent solution type, etc., and the impregnation rate is 80 to 1 as solid content per 100 parts by weight of dry sheet.
60 weight parts is desirable. If the impregnation rate is less than 80 parts by weight, the resin will not flow sufficiently and smearing will occur easily, while if it exceeds 160 parts by weight, the resin will flow too much and the sheet will easily break. A plurality of sheets impregnated with the impregnating resin and dried in this manner are laminated and then hot-press molded. The temperature, pressure, time, etc. during hot-press molding are appropriately set depending on the properties of the resin used and the laminated thickness. Further, the number of sheets to be laminated can be varied as required depending on the desired thickness of the molded plate.

(Effect of the invention) The artificial marble Gaeshi obtained in this way has an inorganic texture.

It is a completely new type of building interior and exterior material that has textures such as transparency and weight that are comparable to those of natural marble, and physical properties and secondary processability that are even superior to natural marble. It can be applied to a wide range of applications such as furniture, system kitchens, indoor spaces, exterior materials, and more.

(Example) Next, the present invention will be specifically explained with reference to Examples.

<Example 1> 40 parts by weight of cotton linter/4 loops, 20 parts by weight of long glass fiber strands (manufactured by Asahi Fiberglass Co., Ltd., average fiber diameter 6μ, average fiber length 6 rra), silica powder (refraction 19 parts by weight of aluminum hydroxide powder (refractive index: 1.57), 2 parts by weight of titanium oxide (refractive index: 2.71) are dispersed in water, and water-soluble melamine resin paper is further dispersed. After adding 1 part by weight of a force enhancer and adjusting the pH to 5.5 with aluminum sulfate and sodium aluminate, it was heated to a basis weight of 150 i/r using a Tappi sheet machine.
n sheets were made. Next, a water-soluble melamine resin (Nikaresin manufactured by Nippon Car Guito Co., Ltd.) was applied at a solid content impregnation rate of 1.
After impregnating the sheet with 40 ml and drying, soak the same sheet with 1
Two sheets were laminated and pressed at a temperature of 160°C and a pressure of 100 J/m2 for 300 minutes. The finished board was 3m thick. We compared the performance of this molded board with conventional marble pattern printed high-pressure melamine resin decorative boards, aluminum hydroxide powder crosswired methyl methacrylate resin molded boards, unsaturated 4-lyester resin molded boards, and natural marble. The results are shown in Table 1.

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Tatami Tatami 4I Tatami Tatami Tatami table-1 results Example 1
The artificial marble was of excellent quality overall.

(Example 2) Molded plates were produced in the same manner as in Example 1, with only the composition ratio of the sheet being varied. The results are shown in Table-2.

From Table 2, it is clear that if the composition ratio of each composition is out of the optimum range, problems will occur.

Claims (1)

[Claims] 1. A: 20 to 80% by weight of cellulose fibers, B: 2 to 40% by weight of organic or inorganic fibers other than cellulose, C: Inorganic filler with a refractive index of 2.0 or less A mixture containing 10 to 70% by weight as a main component is made into an aqueous dispersion, formed into a sheet by a wet paper-making method or a method similar thereto, and then impregnated with a synthetic resin, followed by stacking and hot-pressing a plurality of sheets. A method for producing artificial marble characterized by: 2. The method for manufacturing artificial marble according to claim 1, wherein the synthetic resin to be impregnated is a thermosetting resin.