JPH0363491B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a strong resin molded article. More specifically, the present invention relates to a method of manufacturing a strong resin molded product that can be used for the same purposes as ABS resin from epoxy resin by a casting method. [Conventional technology] Thermoplastic resins such as ABS resin have high impact resistance,
Because it has favorable properties such as high elongation, it is used as a molding material in many fields including automobiles and home appliances. However, when making prototypes of these molded products or manufacturing a wide variety of products in small quantities, for example, even if ABS resin is heated to about 280°C, the melt viscosity does not become low enough to be suitable for casting, so injection molding methods etc. Therefore, it is impossible to avoid economic disadvantages such as the need for expensive molds. On the other hand, thermosetting resins such as epoxy resins are in the monomer or oligomer state when molded, so they can be cast, and silicone resin molds or simple molds can be used, making prototyping extremely inexpensive. , it is possible to mold a wide variety of products in small quantities. However, cured products of thermosetting resins generally have very low impact strength and elongation, and tend to be brittle, and when a flexibility imparting agent such as rubber is mixed in to improve these points, Because it drastically reduces tensile strength, bending strength, compressive strength, etc.
It becomes impractical in terms of the balance of various physical properties. [Problems to be solved by the invention] In view of the current situation, if it is possible to obtain a strong resin molded product that can be molded by a simple method such as casting and has well-balanced physical properties, such a method would be possible. The usefulness of this method is enormous. The object of the present invention is to solve the problem that has been sought, that is, to provide a method for manufacturing strong resin molded products from epoxy resin by an inexpensive casting method. [Means for Solving the Problems] and [Operation] Therefore, the present invention relates to a method for producing a strong resin molded product, and the production of a strong resin molded product involves adding a divalent phenol type liquid epoxy resin to a divalent phenol type liquid epoxy resin. This is carried out by pouring a composition in which phenol and a reaction catalyst for both of them are dissolved into a mold, and then heating the mixture to cause a reaction. As a divalent phenol type liquid epoxy resin,
Mononuclear 2 such as resorcinol and hydroquinone
phenol, bis(4-hydroxyphenyl)
Methane, 2,2'-bis(4-hydroxyphenyl)propane [bisphenol A], 1,1'-bis(4-hydroxyphenyl)ethane, 2,2'-
Diglycidyl ether of polynuclear divalent phenol such as bis(3,5-dibromo-4-hydroxyphenyl)propane, which is liquid at room temperature (25°C), is used. Examples of divalent phenols include mononuclear or polynuclear divalent phenols as described above, or divalent phenols obtained by reacting divalent phenols at both ends of the epoxy resin, which dissolve in the liquid epoxy resin. is used. Examples of reaction catalysts include quaternary ammonium salts such as benzyltriethylammonium chloride and tetraethylammonium bromide; tertiary amines such as N,N-benzylmethylamine and P-dimethylaminobenzaldehyde;
- imidazoles such as ethyl-4-methylimidazole, phosphines such as triphenylphosphine, quaternary phosphonium salts such as triphenylethylphosphonium halide, which are dissolved in the mixture of the liquid epoxy resin and divalent phenol, Those that act as catalysts for these reactions are used. Among these components, diglycidyl ether of 1,1'-bis(4-hydroxyphenyl)ethane was used as the divalent phenol type liquid epoxy resin, and 1,1-bis(4-hydroxyphenyl) ethane was used as the divalent phenol.
-Hydroxyphenyl)ethane or a combination of the two is particularly preferred because the viscosity of the composition during casting is low and the resulting resin molded product is also stronger. The castable composition used in the present invention is prepared using each of the above components as essential components, and the liquid epoxy resin and divalent phenol have a ratio of hydroxy equivalent of divalent phenol to epoxy equivalent of about 0.8 to
Commonly used ratios are in the range 1.2.
If this ratio is lower than this, the resulting product will have a low molecular weight and will not be able to form a strong molded product. On the other hand, if the ratio is higher than this, the amount of unreacted divalent phenol increases, resulting in a loss of toughness. In addition, the reaction catalyst is about 0.01 to 2% of the total amount of epoxy resin and divalent phenol.
Commonly used in percentages. The castable composition is prepared by first dissolving dihydric phenol in a liquid epoxy resin by heating it generally to about 50 to 180°C, preferably about 80 to 150°C, and then adding a reaction catalyst thereto. It will be done. Note that other epoxy resins, such as diglycidyl esters of aromatic dicarboxylic acids, and other polyhydric phenols, such as trivalent phenols, may be added to this composition without departing from the purpose of the present invention. You can also do it. The prepared composition is poured into a simple mold, such as a resin mold such as a silicone resin, an epoxy resin mold, or a mold such as aluminum, and is generally heated at about 100 to 180°C, preferably about 100 to 150°C, for about 1 hour. ~
By heating for 15 hours, preferably about 3 to 5 hours, it reacts and polymerizes to give a tough resin molded article. At this time, if the shape of the molded product is complex,
In order to prevent the generation of bubbles, the reaction may be carried out under reduced pressure. [Effects of the Invention] The composition used in the present invention can be cast, and therefore not only can it be molded with a simple mold, but the molded product has excellent impact resistance, elongation, mold shrinkage, dimensional accuracy, etc. Because it exhibits excellent, strong, and well-balanced physical properties, it can be effectively used in the field of molded products where ABS resin and other molding materials have traditionally been used as molding materials. [Example] Next, the present invention will be explained with reference to an example. Example 1 Diglycidyl ether type liquid epoxy resin of bisphenol A (epoxy equivalent: 190, viscosity:
60 parts of bisphenol A was dissolved in 100 parts (by weight, same below) of 14,000 cps) at 130°C, and then 0.7 part of triphenylphosphine as a reaction catalyst was dissolved. The obtained liquid composition was cast into a simple resin mold made of silicone rubber, reacted at 150° C. for 4 hours, cooled to room temperature, and then the molded product was taken out from the mold. Example 2 In Example 1, the same amount of diglycidyl ether of 1,1'-bis(4-hydroxyphenyl)ethane (epoxy equivalent weight 173, viscosity 3000 cps) was used as the liquid epoxy resin, and bisphenol A was used. The amount was changed to 65 parts, and 0.6 parts of benzyltriethylammonium chloride was used as a reaction catalyst. Example 3 In Example 1, the same amount of diglycidyl ether of 1,1'-bis(4-hydroxyphenyl)ethane (epoxy equivalent 173, viscosity 3000 cps) was used as the liquid epoxy resin, and bisphenol A was replaced with 61 parts of 1,1'-bis(4-hydroxyphenyl)ethane were used, and N,N-
0.4 parts of benzyldimethylamine was used and the temperature was 120°C.
The reaction was carried out for 5 hours. The physical properties of the molded articles obtained in each of the above Examples were measured, and the results are shown in the table below. Comparative Example 1 100 parts of the liquid epoxy resin used in Example 1 and 20 parts of aliphatic polyamine (Mitsui Epoxy Product Q-604) as a curing agent were mixed and cast into the above simple resin mold made of silicone rubber. Room temperature, -80℃ for 1 day, 1
Cured under conditions of hours. Comparative Example 2 30 parts of the liquid epoxy resin used in Example 1,
Epoxidized butadiene (Nippon Soda product; epoxy equivalent 500, viscosity 170 poise/50) 70 parts, N-aminoethylpiperazine 11 parts and nonylphenol 5
The components were mixed and cured in the same manner as in Comparative Example 1. The above comparative examples all had good castability, and therefore, after curing, they were taken out of the mold and their physical properties were measured. The results obtained are shown in the table below. Comparative example 3 I tried to cast using ABS resin, but the temperature was 280℃.
However, the melt viscosity did not decrease to such a level that it could be cast, and casting was completely impossible. Therefore, the temperature is about 280℃,
Samples for measuring physical properties were prepared by injection molding at an injection pressure of 600 kg/cm ³ . The results of measurements of physical property values conducted in the same manner are also listed in the following table. 【table】

Claims (1)

[Scope of Claims] 1. A tough resin characterized by casting a composition obtained by dissolving divalent phenol and a reaction catalyst for both in a divalent phenol type liquid epoxy resin into a mold and then subjecting it to a heating reaction. Method of manufacturing molded products. 2 Divalent phenol type liquid epoxy resin is 1,1
- The method for producing a tough resin molded article according to claim 1, which is diglycidyl ether of bis(4-hydroxyphenyl)ethane. 3 Claim 1 in which the divalent phenol is 1,1-bis(4-hydroxyphenyl)ethane
A method for producing a strong resin molded product as described in Section 1.