JPH0544333B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for manufacturing a sanderch board, and more particularly, to a method for manufacturing a plastic sanderch board in which a plastic layer is formed between surface materials by a reaction injection method. (Prior Art) Conventionally, plastic sanderch boards (hereinafter referred to as sanderch boards) are obtained by laminating low-foam or non-foam plastic as a core material and a hard plastic surface material such as metal or FRP. However, as a lightweight structural material with improved mechanical properties, particularly rigidity and impact resistance, it is widely used in automobile bodies, construction panels, and ship superstructures. This plastic board is usually manufactured by obtaining a core plastic sheet by injection molding, extrusion molding, etc., and then laminating metal or hard plastic onto the surface using an adhesive using a hot press. Thereafter, it is subjected to secondary processing into a desired shape. However, this method of manufacturing sanderch boards has disadvantages such as low productivity because the pre-formed plastic core material and surface material such as metal are heat-pressed using an adhesive, and they cannot be welded during secondary processing. It was hot. (Problems to be Solved by the Invention) As a result of intensive studies in order to solve the above-mentioned drawbacks, the present inventors have found that a reaction solution containing a norbornene unit-containing monomer and a metathesis catalyst is injected between the surface materials using a reaction injection molding method. It has been discovered that by polymerization, it is possible to easily produce a lightweight Sanderutsch plate with excellent mechanical properties, and based on this knowledge, the present invention has been completed. (Means for Solving the Problems) Thus, according to the present invention, a plastic sandwich plate is manufactured by injecting and polymerizing a reaction solution containing a norbornene unit-containing monomer and a metathesis catalyst between the surface materials by a reaction injection molding method. A method is provided. By the method of the present invention, plastic sanderch boards having unfoamed and foamed polymer cores can be easily produced. The norbornene unit-containing monomer used in the present invention is represented by general formula (1) or (2).

【formula】

[Formula] (In the formula, R ₁ to _{R 4} represent hydrogen or a substituent, and R ₁ and
R ₂ , R ₃ and R ₄ may form a saturated or unsaturated ring). Specifically, 2-norbornene, 5-methyl-2-
norbornene, 5,6-dimethyl-2-norbornene, 5-ethyl-2-norbornene, dicyclopentadiene, dihydrodicyclohentadiene,
Examples include methyltetracyclododecene and mixtures thereof. Further, mono- and dicycloolefins such as cyclobutene, cyclopentene, cyclooctene, and cyclododecene, which can be ring-opening copolymerized with one or more of these monomers, can be used in combination. These monomers are converted into polymers by known ring-opening polymerization, and known metathesis polymerization catalysts are used as catalysts for ring-opening polymerization. - A catalyst system comprising a tungsten-containing compound such as tungsten hexachloride and tungsten oxytetrachloride and an alkyl aluminum halide such as diethylaluminum chloride and ethylaluminum dichloride disclosed in Publication No. 129013;
Organic ammonium molybdates or tungstates such as alkyl aluminum halides and tridodecyl ammonium molybdates and tungstates disclosed in JP-A-58-127728 and JP-A-59-51911 Examples include metathesis polymerization catalysts consisting of a transition metal compound such as a catalyst system consisting of a cocatalyst such as an organometallic compound or a Lewis acid. These two component catalysts are separately mixed with the norbornene unit-containing monomer,
Use as a two-part reaction solution. For example, the amount of molybdenum- or tungsten-containing catalyst used is usually in the range of 0.01 to 50 mmol per mole of total monomer as molybdenum or tungsten. The amount of the alkylaluminium halide catalyst used is usually in the range of 200:1 to 1:10 in terms of molar ratio of aluminum to molybdenum or tungsten. The reaction injection molding (referred to as RIM) method used in the present invention is known as a method for producing polyurethane molded bodies from polyols and diisocyanates. The present invention is characterized by the use of a two-component reaction solution that has a much lower viscosity than the urethane RIM method as well as injection molding of thermoplastic polymers, and allows the surface material to be molded at a low pressure of only 10 kg/cm ² or less. This is a process that can be injected between surfaces and quickly polymerize between the surface materials to produce the desired plastic sander board. In the present invention, for example, the monomer to be used is divided into two parts, the first component of the catalyst is added to one part, and the second component of the catalyst is added to the other part, and the resulting two liquids are mixed between the surface material using the RIM method. Polymerization and integration of the surface material and core material are carried out simultaneously. During injection, the two reaction solutions are usually mixed in a RIM machine and injected between the facing materials. The temperatures of the reaction solution and the surface material are each selected in the range of 20 to 150°C, taking into account the reaction rate. Further, it can also be post-cured if necessary. When the core material is a foam, a foaming agent is added to the reaction solution and injected between the surface materials. As the foaming agent, a foaming agent normally used in RIM can be used, but it is necessary that it does not inhibit polymerization. Particularly preferred blowing agents are usually liquid, readily available low-boiling organic compounds such as hydrocarbons such as pentane, hexane, halogenated hydrocarbons such as methylene chloride, trichlorofluoromethane, or nitrogen, argon, dichlorodifluorocarbons, etc. Examples include inert gases such as methane. The amount of blowing agent used varies depending on the foaming rate, but is usually in the range of 2 to 30% by weight based on the total amount of monomer and catalyst. Furthermore, in the present invention, plasticizers, impact-resistant agents, fillers, flame retardants, antioxidants, and the like can be mixed into the reaction liquid as necessary. The surface agent used in the present invention is a metal or a hard plastic, specifically a metal plate made of steel or aluminum, or a thin film made of epoxy resin, phenolic resin, unsaturated polyester, etc., reinforced with glass fiber or carbon fiber, etc. An example is a plastic board. In addition, the shape of the surface material may be either a flat plate or one that has been pre-secondarily processed into the desired shape.If the core material is injected into the surface material that has been pre-secondarily processed into the desired shape, welding is required. Very preferable. (Effects of the Invention) Thus, the plastic sanderboard board obtained by the present invention can be produced much more easily than in the prior art, and a lightweight structural material with excellent mechanical properties can be obtained. The present invention will be explained in more detail with reference to Examples below. In addition, parts and percentages in Examples are based on weight unless otherwise specified. Example 1 Desired amounts of dicyclopentadiene were placed in two containers, and in one container, diethylaluminum chloride was adjusted to a concentration of 0.048 mol per mol of the monomer. Similarly in the other container
WCl ₆ was added to a concentration of 0.007 molar. The above-mentioned two-part reaction solution prepared in this way was mixed into 1:
Mix at a ratio of 1:1 to 0.6mm thick ultra-thin steel plate with a thickness of 0.2mm.
The mixture was poured into a mold heated to 50° C. and polymerized for 2 minutes to obtain a plastic sandwich steel sheet with a thickness of 1 mm. Table 1 shows the results of measuring the bending rigidity and specific gravity of the plastic sandwiched steel sheet thus obtained. Example 2 A plastic sandwich steel plate was obtained in exactly the same manner as in Example 1 except that dicyclopentadiene was replaced with methyltetracyclododecene, and subjected to measurements of bending rigidity and specific gravity. The results are shown in Table 1.

[Table] As is clear from the results, in all the examples of the present invention, it is possible to easily obtain sanderch boards that are significantly lighter in weight with minimal deterioration in mechanical properties. Example 3 100 parts of orthophthalic acid-based unsaturated polyester (PM-141 manufactured by Dainippon Ink Co., Ltd.), 100 parts of calcium carbonate (NS-200 manufactured by Nitto Funka Kogyo Co., Ltd.) as a filler
Part, glass fiber (chopped strand mat)
MC450) with a glass content of 30%,
Further, 2 parts of zinc stearate and 2 parts of a catalyst (benzoyl peroxide) were added as a mold release agent, and the mixture was pressed for 3 minutes at a mold temperature of 120° C. under a pressure of 28 kg/cm ² to obtain an FRP with a thickness of 3 mm. The FRP thus obtained was held at intervals of 10 mm, and the same two-part dicyclopentadiene as in Example 1 was injected and reacted to obtain a 16 mm thick sandwich plate. Table 2 shows the results of measuring the bending rigidity and specific gravity of the plastic sanderboard thus obtained.

【table】

Claims (1)

[Claims] 1. A method for producing a plastic sanderch board, which comprises injecting a reaction solution containing a norbornene unit-containing monomer and a metathesis catalyst between the surface materials and polymerizing the reaction solution using a reaction injection molding method.