JPS6318618B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention can provide a cured molded product with excellent hardness, gloss, electrical insulation, water resistance, chemical resistance, flexibility, etc., as well as excellent metal insertability and molding processability with improved fluidity during molding. The present invention relates to a thermosetting amino resin molding material having the following properties. More specifically, about 0.1 to about 0.1 to about 0.1 to about 100 parts by weight of a thermosetting amino resin obtained by reacting 1 to 4 mol of formaldehyde with 1 mol of an amino resin-forming amino component is added. The present invention relates to a thermosetting amino resin molding material containing 30 parts by weight, preferably about 0.5 to about 10 parts by weight, an acid curing catalyst, and a filler. Conventionally, xylene-formaldehyde resins such as m-xylene-formaldehyde resins have shown excellent properties such as water resistance, light resistance, chemical resistance, and electrical insulation properties, so their use as modifiers for molding materials has been desired. Ta. However, the resin itself has relatively poor reactivity and has problems such as poor compatibility with thermosetting amino resins, so its use has been restricted. For example, Japanese Patent Publication No. 38-12198 describes a phenol-modified product obtained by condensing m-xylene-formaldehyde resin with a phenol having a molecular weight of 1 or more per 1 atom of oxygen contained in this resin under an acid catalyst. A method has been proposed for producing m-xylenephenolmelamine cocondensation resin by adding hexamethylolmelamine to m-xylene-formaldehyde resin and heating and curing it using an alkaline catalyst. In this proposal, since the low molecular weight m-xylene-phenol resin does not contain any reactive groups, it will not harden even if it is heated as it is. It states that it cross-links and hardens. However, the cured product of hexamethylol melamine has the disadvantage of poor crack resistance, the stability of the resin liquid during production is poor, and production is difficult.Also, the light resistance of m-xylene-formaldehyde resin is reduced due to phenol modification. It has the disadvantage that it produces unsatisfactory results as a molding material due to the fact that it can be used as a molding material. The present inventors have developed a thermosetting amino-based resin molding material that has a thermosetting amino-based resin as its main component, and which exhibits improved fluidity and suitability for molding during molding. We conducted research to provide this information. As a result, low methylolated melamine, especially 1 to 1 mole of amino resin-forming amino component,
By blending a relatively small amount of xylene-formaldehyde resin as a subcomponent with respect to the main component amount of the thermosetting amino resin obtained by reacting 4 moles, preferably 1 to 2 moles of formaldehyde. It has been discovered that the compatibility between the two can be significantly improved, and the fluidity during molding can be significantly improved, giving excellent molding processability. Furthermore, it was found that the hardness, gloss, electrical insulation, water resistance, chemical resistance, flexibility, etc. of the resulting hot-press molded product were further improved, and metal insertability was improved. Furthermore, it has been found that injection molding of the thermosetting amino resin molding material is facilitated, and injection molded products with significantly improved quality reproducibility can be obtained. Therefore, an object of the present invention is to provide a thermosetting amino resin molding material having excellent and improved properties. The above objects and many other objects and advantages of the present invention will become more apparent from the following description. The thermosetting amino resin used in the present invention is a resin obtained by reacting 1 to 4 moles of formaldehyde with 1 mole of the amino resin-forming amino component. Examples include melamine, urea, guanamines, etc. These may be used together. Examples of thermosetting amino resins obtained by reacting such amino components with formaldehyde include melamine resins, urea resins, guanamine resins, and co-condensed resins thereof. The reaction molar ratio of such a thermosetting amino resin is 4 moles or less of formaldehyde per 1 mole of the amino component, and is preferably selected appropriately depending on the type of the amino component. For example, in the case of melamine and formaldehyde, the melamine:formaldehyde (molar ratio) is about 1:1.2 to 1:4, more preferably about 1:1.4 to 1:2, and in the case of urea and formaldehyde, the melamine:formaldehyde (molar ratio) is about 1:1.2 to 1:4. (molar ratio) is about 1:1 to 1:3.5, more preferably about 1:1.1 to 1:2. Further, the guanamines:formaldehyde (molar ratio) is also the same as the above-mentioned case of urea:formaldehyde. If the reaction molar ratio of formaldehyde to 1 mole of the amino component is too low, less than 1 mole, it will be difficult to convert the amino component into a resin, which is undesirable, and if it is too high, exceeding 4 moles, the metal insertability of the molded product will deteriorate. I don't like it because it makes it worse. Examples of guanamines include benzoguanamine, acetoguanane, and mixtures thereof. Also, a part of formaldehyde can be replaced with other aldehydes such as acetaldehyde and furfural. Furthermore, the thermosetting amino resin may be modified with, for example, phenol, urea, thiourea, benzoguanamine, acetoguanamine, dicyandiamide, para-toluenesulfonic acid amide, or sucrose, or alternatively, phenolic resin,
It is also possible to use a blended resin partially substituted with a thermosetting or thermoplastic resin such as urea resin, polyester resin, or epoxy resin. The xylene-formaldehyde resin used in the present invention is typically m-xylene-formaldehyde resin, but other isomers of xylene or xylene-formaldehyde resins containing them may also be used, or they may be modified with phenols. It can also be a xylene-formaldehyde based resin. In the present invention, the xylene-formaldehyde resin as exemplified above has a number average molecular weight of about
300 to about 1000 and oxygen content of about 6 to about 14 can be preferably used. These thermosetting amino resins and xylene-formaldehyde resins are
It can be manufactured by a method known per se, and can also be obtained on the market. In the present invention, the xylene-formaldehyde resin is used in an amount of about 0.1 to about 30 parts by weight based on 100 parts by weight of the above-mentioned thermosetting amino resin. More preferably, from about 0.5 to about 10 parts by weight are utilized. If the amount of xylene-formaldehyde resin used is too small, it will be difficult to achieve the improvement objective of the present invention, and if it is too large, the compatibility with the thermosetting amino resin and the physical properties of the resulting molded product will be affected. It is better to use the amount in the above proportion as it may cause trouble. The thermosetting amino resin molding material of the present invention further contains an acidic curing catalyst and a filler. Examples of such acidic curing catalysts include phthalic anhydride, benzoic acid, and amine salts of p-toluenesulfonic acid. Examples of fillers include cellulose fillers such as pulp and wood flour, as well as talc, charcoal, silica,
Examples include organic and inorganic fillers such as glass fibers, vinylon fibers, and Tetron fibers. The amount of the acidic curing catalyst as exemplified above can be selected as appropriate, but for example, about 0.01 to about 5 parts by weight, more preferably about 0.01 to about 3 parts by weight, based on the weight of the thermosetting amino resin. For example, the usage amount may be as follows. Further, the amount of fillers as exemplified above can be appropriately selected within a wide range;
Examples include amounts used such as parts by weight, more preferably about 25 to about 70 parts by weight. The thermosetting amino resin molding material of the present invention may further contain colorants such as titanium oxide, red iron oxide, cyanine blue, titanium yellow, and carbon black; for example, zinc stearate, butyl stearate, glycerin monostearate, Other additives may be included, such as lubricants such as monostearates. The amount of these other additives to be used can be selected and changed as appropriate, but for example, based on the total weight of both resins,
Examples of amounts used include about 0.0001 to about 5 parts by weight of colorant, and about 0.01 to about 5 parts by weight of lubricant. The thermosetting amino resin molding material of the present invention can be prepared by blending the above-mentioned thermosetting amino resin, xylene-formaldehyde resin, acidic curing catalyst, filler, and other additives as desired in an appropriate order and means. It can be manufactured by For example, there are methods in which the additives are added at the same time as they are crushed and mixed in a ball mill during the process of molding ordinary molding materials, and methods in which they are added when crushed and mixed in a Henschel mixer etc. without using a ball mill. Dry blend method, for example, a method in which pulp and resin are added in a kneader during kneading, in which a normal compound without the addition of xylene resin is prepared in advance, and this and xylene resin are added and mixed in a ball mill, Henschel mixer, etc. A wet blending method, such as a method of hot kneading materials using an extruder or the like, can be used. Hereinafter, several embodiments of the composition of the present invention and its preparation will be illustrated in more detail by way of examples. Example 1 Melamine 100 parts by weight, 37% formalin aqueous solution 116
parts by weight and 120 parts by weight of water were placed in a reaction tank equipped with a stirring device equipped with a reflux condenser, and the pH was adjusted to 8 to 9 with NaOH.
After adjusting to pH, methylolation was performed at 80°C to 90°C, and then the pH was adjusted to 6 to 7 with hydrochloric acid. Continue stirring and add more hydrochloric acid for 30 minutes.
The pH was brought back to 8-9 with NaOH. Pulp is added to the obtained melamine-formaldehyde initial condensation resin liquid.
After adding 60 parts by weight and kneading, it was dried by a conventional method. It contains zinc stearate as a lubricant.
0.7 parts by weight, 2 parts by weight of titanium oxide as a pigment,
A mixture containing 0.2 parts by weight of phthalic anhydride and 5 parts by weight of m-xylene-formaldehyde resin (Nicanol H manufactured by Mitsubishi Gas Chemical) as a catalyst was pulverized in a Henschel mixer and heat-treated at 130°C in an extruder. Sample A was prepared by pulverizing it into granules. Example 2 In Example 1, m-xylene-formaldehyde resin [Nicanol H] was replaced with 5 parts by weight.
Sample B was obtained by adding 10 parts by weight. Example 3 In Example 1, instead of 5 parts by weight of m-xylene-formaldehyde resin [Nicanol H], m
Sample C was prepared by adding 5 parts by weight of xylene formaldehyde resin [Nicanol L]. Example 4 In Example 1, instead of 5 parts by weight of m-xylene-formaldehyde resin [Nicanol H], m
- Sample D was prepared by adding 10 parts by weight of xylene formaldehyde resin [Nicanol L]. Example 5 100 parts by weight of urea and 170 parts by weight of a 44% formalin aqueous solution were placed in a reaction tank equipped with a reflux condenser and a stirring device, and 0.6 parts by weight of hexamine was added to adjust the pH of the aqueous solution to 8 to 9.
The mixture was adjusted to 70°C and reacted for 1 hour. After adding 60 parts by weight of pulp to this material, the mixture was kneaded and dried by a conventional method. 0.5 parts by weight of zinc sterate as a lubricant, 2 parts by weight of titanium oxide as a pigment, 0.03 parts by weight of ammonium chloride as a catalyst, and 5 parts by weight of m-xylene-formaldehyde resin [Nicanol L manufactured by Mitsubishi Gas Chemical] were added. pulverized with a Henschel mixer and heated to 110℃ with an extruder.
Sample E was prepared by heat-treating the sample and pulverizing it into granules. Example 6 0.1 benzoic acid in 100 parts by weight of benzoguanamine resin
parts by weight, 0.5 parts by weight of zinc stearate, 43 parts by weight of wood flour
Parts by weight, m-xylene-formaldehyde resin
10 parts by weight were added and mixed by pulverization in a ball mill for 6 hours. The material is then heat-treated at 120℃ using an extruder.
Sample F was prepared by pulverizing it into particles. Example 7 In Example 1, instead of 5 parts by weight of m-xylene-formaldehyde resin, novolac-modified m-
Xylene resin [Mitsubishi Gas Chemical Nicanol UP]
Sample G was prepared by adding 5 parts by weight of 100]. Comparative Example 1 Sample a was obtained by adding 0.05 parts by weight of m-xylene-formaldehyde resin [Nicanol H] instead of 5 parts by weight in Example 1. Comparative Example 2 In Example 1, 50 parts by weight of m-xylene-formaldehyde resin [Nicanol H] was used instead of 5 parts by weight.
Sample B was obtained by adding part by weight. Comparative Example 3 Sample c was obtained by adding no xylene-formaldehyde resin in Example 1. Comparative Example 4 Sample d was prepared by adding no xylene-formaldehyde resin in Example 5. Molding material A of the present invention prepared as described above
The following tests were conducted using E and comparative molding materials a to d, and the results are shown in Tables 1 to 2 below. (1) Disc flow test: - Based on JIS K-6911. Measure the elongation of the disc at points 5, 3, and 2. Molding is performed at a mold temperature of 150℃ (surface). (2) Gloss test: - Compression mold a test piece measuring 70m long, 60m wide and 3m high (molding temperature: 160℃, molding pressure: 210℃)
Kg/cm ² , curing time 2 minutes). The gloss of the molded product was measured using a gloss meter TG-P manufactured by Tokyo Denshoku Co., Ltd. Measured at an incident angle of 60°C, refractive index
Glossiness is measured with the specular glossiness of the glass surface of 1.567 as 100%. (3) Metal insertability test: - A cylindrical test piece with a diameter of 8 mm and a height of 7 mm was embedded in a knurled insert fitting (36 mm in diameter and 3 mm in height) at a molding temperature of 155°C and a molding pressure of 200 kg/
cm ² and molding time is 3 minutes. The resulting 10 test pieces per sample were heated to 125°C.
Put it in a hot air dryer for 20 minutes, then take it out and put it in water for 5 minutes.
Add a minute and leave it at room temperature for another 10 minutes.This is one cycle and the test is repeated 25 times. Record the number of cycles in which abnormalities such as cracks occurred and the number of test pieces in which abnormalities occurred.

【table】

[Table] Comparative Example 5 In Example 1, 37% formalin aqueous solution 322
Parts by weight (5 formaldehyde per mole of melamine)
The experiment was repeated as in Example 1, except that mol) was used. When the obtained molding material was tested in the same manner as in Example 1, the disc flow test was
151mm, the gloss test was 98%, and the metal insert test showed 10 cracks within 24 hours after molding. Comparative Example 6 In Experiment 1, the experiment was repeated in the same manner as in Example 1 except that 26 parts by weight of a 37% formalin aqueous solution (0.4 mol of formaldehyde per 1 mol of melamine) and 93 parts by weight of water were used, but the reaction was carried out at 70°C for 1 hour. However, the melamine did not dissolve and the resin formation did not proceed, so further experiments were discontinued. As is clear from the results in Tables 1 and 2 above, the thermosetting amino resin molding material containing the xylene-formaldehyde resin of the present invention exhibits significantly improved high fluidity and its moldability. The product has high gloss and good metal insertability. Therefore, it can be used in the field of molded products that has not been available until now. For example, it can be used for tableware such as teacups, bowls, and bowls that have a reverse taper, ashtrays, and the like.

Claims (1)

[Claims] 1. For 100 parts by weight of a thermosetting amino resin obtained by reacting 1 to 4 moles of formaldehyde with 1 mole of an amino resin-forming amino component,
A thermosetting amino resin molding material containing 0.1 to 30 parts by weight of a xylene-formaldehyde resin, an acidic curing catalyst, and a filler.